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Lithiation of a crystalline silicon anode proceeds by the movement of an atomically sharp reaction front that separates a pristine crystalline phase and a fully-lithiated amorphous phase. The velocity of the reaction front is limited rather by the reaction rate at the lithiation front than by the diffusivity of lithium ions in the amorphous lithiated phase. Experiments on solid nanoparticle/nanowire silicon anodes show an initial rapid advancing of reaction front at the initial stage of lithiation, followed by an apparent slowing or even halting of the reaction front propagation. Lithiation-induced stresses during lithiation are attributed to alter the driving force of lithiation and thus result in the observed slowing of reaction front. Recent experiments on lithiation of hollow silicon nanowires reveals similar slowing of reaction front, however, quantitative study of the effect of lithiation-associated stress on the driving force of lithiation still lacks so far. Here, through chemo-mechanical modeling and theoretical formulation, we present a comprehensive study on lithiation-induced stress field and its contribution to the driving force of lithiation reaction in hollow silicon nanowire anodes. We show that hollow silicon nano-anodes could be fully lithiated with lower stress-induced energy barrier than solid silicon nano-anodes. As a result, it is expected that the hollow nanowires and nanoparticles may serve as an optimal structural design for high-performance anodes of lithium-ion batteries. Results from the present study shed light on a number of open questions of lithiation kinetics of silicon-based anodes in recent literature and offer insight on developing silicon-based anodes with high charging capacity and high charging rate. | battery |
Organolead halide perovskite solar absorbers demonstrate high photovoltaic efficiencies but they are notorious for their intolerance to water. Now, methylammonium lead iodide perovskites are used to harvest solar energy — in water — via photocatalytic generation of hydrogen from solutions of hydriodic acid.
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This paper addresses the problem of secure data transmission and balanced energy consumption in an unattended wireless sensor network (UWSN) comprising of multiple static source nodes and a mobile sink in the presence of adversaries. The proposed system comprises of three phases: the identification of data collection points (convex nodes), path planning by the mobile sink, and secure data transmission. An energy-aware convex hull algorithm is used for the identification of data collection points for data transmission to the mobile sink. Data transmission from sensor nodes to the nearest data collection point is performed using multihop communication and from sensor nodes to the mobile sink in a single hop. Data are securely transmitted through an elliptic curve cryptography based ElGamal scheme for message authentication. A data packet is associated with a digital signature. The variation in a digital signature and threshold energy obtained using support vector machine is used to determine the presence of malicious nodes in the network. The performance of the proposed system is evaluated using Cooja simulator by Contiki for various node counts under a static sink and mobile sink, with different threat scenarios. The results indicate that the proposed system is resilient against threats and provides satisfactory performance | non-battery |
Novel hierarchically porous titanium-metal organic frameworks/nitrogen-doped graphene (Ti-MOFs/NG) nanocomposite derived from titanium-metal organic frameworks (Ti-MOFs) and the nitrogen-doped graphene (NG) has been originally synthesized successfully. Notably, the Ti-MOFs/NG nanocomposite has been for the first time investigated in detail, as oxygen reduction reaction (ORR) catalyst of cathodic materials for fuel cells. The results show that the Ti-MOFs/NG nanocomposite possesses excellent ORR performances, whether in alkaline or acidic medium, due to existences of the Ti3N2-x, C2O7Ti2.3, H2Ti5O11, Ti and TiO active ORR segments. Specifically, the onset potential (E0) and the Tafel slope value of the Ti-MOFs/NG nanocomposite are 1.14 V and 17.84 mV dec−1 in 0.1 M HClO4, respectively. Similarly, high ORR efficiency of the Ti-MOFs/NG nanocomposite also exhibit in alkaline medium. The relative current density can still keep 99.88% of the original value after 10800 s measurements in 0.1 M KOH. Additionally, small electrochemical impedance and excellent tolerance toward fuel molecules have been exhibited in both electrolytes. These ORR properties are superior to those of most of previously reported materials derived from other MOFs, in both alkaline and acidic media. Thus, the Ti-MOFs/NG nanocomposite is as a novel promising candidate for ORR catalyst to solve the main problems of sluggish reaction kinetics of the ORR, high cost of precious metal catalysts and low durability of the traditional catalysts, applied to fuel cells, metal-air batteries and further to water splitting in energy conversion and storage devices. | battery |
Does childrearing affect the biological functioning of parents? To address this question, we analyze cross-sectional survey and biomarker data from Vanderbilt University’s Nashville Stress and Health Study, a probability sample of non-Hispanic White and Black working-age adults from Davidson County, Tennessee (2011–2014; n = 1252). Multivariable regression analyses reveal a linear dose–response relationship between the number of children living in a respondent’s home and (a) increased allostatic load, and (b) decreased leukocyte telomere length. We found no differences in biological functioning between childless respondents and empty-nest parents. These findings also withstood controls for a battery of socioeconomic factors. The implications of these findings and suggestions for future research are discussed.
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Three-phase gas-diffusion oxygen electrodes for metal air battery were prepared and characterized. Nano-structured γ-MnO2 catalysts were synthesized by solid state redox reaction of two compounds, Mn(CH3COO)2·4H2O and C2H2O4·2H2O. Their crystal phase, morphologies and particle size were characterized by XRD, TEM, respectively. The electrochemical property of three-phase gas-diffusion oxygen electrodes composed of nano-structured γ-MnO2 catalysts for oxygen reduction was examined by using the linear polarization method in a neutral solution. Besides, the surface morphologies of the catalytic layer of three-phase gas-diffusion oxygen electrodes were also investigated by SEM. Experimental results revealed that these kinds of three-phase gas-diffusion oxygen electrodes have excellent electrochemical performance. The optimal proportion of nano-structured γ-MnO2 catalysts in the catalytic layer was 60wt.%. Three-phase gas-diffusion oxygen electrodes composed with nano-structured γ-MnO2 catalysts appear to be a highly possible candidate for applications in neutral solution metal air battery. | battery |
The use of agricultural and food processing waste is an important source of biomass fuel for energy generation in rural and remote locations. In particular, gasification of cashew nut shell has a high potential for clean electricity generation due to its relative high energy content. In this study, the techno-economic assessment of a solar photovoltaic-biomass gasification hybrid system is carried out for a case study in Nampula, Mozambique. Model results and sensitivity analysis show that this system is able to achieve competitive levelised cost of electricity when compared with diesel generators. | battery |
Porous Co(OH)2/Ni composite nanoflake array is prepared by combing hydrothermal synthesis and electrodeposition methods. The as-prepared Co(OH)2/Ni composite nanoflake array exhibits a highly porous array structure composed of free-standing nanoflakes with thicknesses of 35–40nm. The pseudocapacitive behavior of the Co(OH)2/Ni composite nanoflake array is investigated by cyclic voltammograms (CV) and galvanostatic charge–discharge tests in 2M KOH. As cathode material for supercapacitor, the porous Co(OH)2/Ni composite nanoflake array exhibits weaker polarization, higher electrochemical activity and better cycling performance as compared to the unmodified Co(OH)2 nanoflake array. The Co(OH)2/Ni composite nanoflake array shows specific capacitances of 1310Fg−1 at 1Ag−1 and 1148Fg−1 at 40Ag−1, much higher than those of the unmodified Co(OH)2 nanoflake array (1017Fg−1 at 1Ag−1 and 775Fg−1 at 40Ag−1). The enhancement of supercapacitor properties is due to the introduction Ni in the composite array, which improves the electric conductivity of the film electrode with fast reaction kinetics. | battery |
Ambient temperature sodium-ion batteries are emerging as a new chemistry platform for energy storage technologies. Anodes that consist of carbon have been used for this application due to their highly stable and reversible Na cycling nature. In the search of new carbon materials with various microstructure morphologies, we have synthesized spherical carbon particles via an autogenic process. 23Na MAS solid-state NMR characterization method as a function of the state of charge of carbon was used to determine that these spherical carbon anodes show pure, reversible Na intercalation into graphene regions: these materials are devoid of nanocavity or nanopore filling of Na. This feature and the spherical morphology create low reactivity behavior with the electrolyte which assists in the material's highly reversible (de)sodiation. Specific capacity is 40mAhg−1 at a high-rate of 10C (1.5Ag−1) thus demonstrating that the graphene element in hard carbons contributes largely to the rate capability. | battery |
Gel polymer electrolyte films comprised of 50% epoxidised natural rubber polymer host, lithium triflate salt (LiCF3SO3), and ethylene carbonate (EC) or propylene carbonate (PC) plasticizer are prepared using the solution-casting technique. AC impedance studies show that the electrical conductivity of the electrolytes is dependent on both the salt and plasticizer concentrations. The highest room temperature conductivity of 4.92×10−4 Scm−1 is achieved when 10wt.% propylene carbonate is introduced into the system containing 1.0g 50% epoxidised natural rubber polymer doped with 35wt.% LiCF3SO3. Conductivity studies of these polymer electrolytes are carried out at various temperatures and are found to obey the Vogel–Tamman–Fulcher (VTF) rule. The highest conducting plasticized sample is used as a gelled electrolyte for lithium–air cells. | battery |
Unknown Note: Page numbers followed by f and t refer to figures and tables, respectively. | non-battery |
The purpose of this paper is to review the current status of the recycling technologies of spent lithium-ion secondary batteries. It introduced the structure and components of the lithium-ion secondary batteries, summarized all kinds of single recycling processes from spent lithium-ion secondary batteries and presented some examples of typical combined recycling processes. Also, the problems and prospect of the studies of their recycling technologies have been put forward. | battery |
A 3D structured NiCo2O4@Co3O4 hybrid was prepared by a two-step hydrothermal approach and subsequently employed as a highly efficient catalyst in oxygen reduction reactions (ORRs)/oxygen evolution reactions (OERs) and from a Li–O2 battery perspective. The Co-NC possesses interconnected NiCo2O4 nanorods grown over a Co3O4 nanosheet structure, which facilitates charge transfer and enhances the electrical conductivity. Moreover, the 3D structured hybrids are directly used as a cathode catalyst for the Li–O2 system and displayed a maximum in-depth-specific discharge capacity of 4386mAhg−1. In addition, significantly improved and stable cycling performance up to 60 cycles is observed compared with Co3O4 nanosheets at the limited capacity range of 500mAhg−1. The excellent electrochemical performance of the NiCo2O4@Co3O4 hybrid is mainly associated with the oxygen-deficient 3D architecture providing more catalytic active sites and can accommodate more discharge products. Further, ORR/OER activities of NiCo2O4@Co3O4 hybrid in aqueous media are also evaluated in 0.1M KOH solution using the rotating ring disk electrode technique. For instance, the OER activity of NiCo2O4@Co3O4 hybrid (apex current is 4.18mAcm−2) is an approximately 2.25 times higher than that of commercial RuO2 catalyst (1.84mAcm−2). Since the catalytic activity in aqueous and organic medium is not necessarily the same, but of NiCo2O4@Co3O4 hybrid exhibiting excellent ORR/OER characteristics in both cases is worth mentioning. | non-battery |
A pressing question in military medical research is the nature and degree of effects on the human brain from occupational repeated exposure to low-level explosive blast, but reliable and effective means to objectively measure such effects remain elusive. In survey results, headache, difficulty sleeping, irritability, cognitive impairment, and a variety of other symptoms consistent with post-concussive syndrome have been reported by those exposed to blast and there was positive correlation between degree of blast exposure and degree of symptomology, but an important goal is to obtain more objective evidence of an effect than self-report alone. This review reflects recent efforts to measure and evaluate such hypothesized effects and current recommendations for ongoing study. Optimal measures are likely those with sensitivity and specificity to systemic effects in mild neurotrauma, that have minimal to no volitional component, and that can be sampled relatively quickly with minimal intrusion in prospective, observational field studies during routine training with explosives. An understanding of an association between parameters of exposure to repeated low-level blast and negative neurologic effects would support the evaluation of clinical implications and development of protective equipment and surveillance protocols where warranted. At present, low-level blast exposure surveillance measurements do not exist as a systematic record for any professional community. | non-battery |
Artificial insemination is not as widely used in horses as in other domestic species, such as dairy cattle and pigs, partly because of the wide variation in sperm quality between stallion ejaculates and partly due to decreased fertility following the use of cooled transported spermatozoa. Furthermore, predictive tests for sperm fertilising ability are lacking. The objective of the present study was to assess sperm morphology and chromatin integrity in ejaculates obtained from 11 warmblood breeding stallions in Sweden, and to evaluate the relationship of these parameters to pregnancy rates to investigate the possibility of using these tests predictively. | non-battery |
Lanthanum oxide nanoparticles (LONP), a rare earth metal oxide, have unique properties that make them a suitable candidate for several biomedical applications. We investigated certain key in vitro and in vivo biocompatibility endpoints on LONP. LONP were cytotoxic in in vitro assays and predominantly exerted their action via release of reactive oxygen species. These nanoparticles were neither irritants nor sensitizers in a rabbit model. LONP extracts did not exert any acute systemic toxicity effects in mice. On the other hand LONP exerted toxicity to the liver following oral administration, suggesting that these particles are absorbed from the gastrointestinal (GI) tract and deposited in the hepatobiliary system. LONP did not induce any mutation in the Ames test both in the presence or absence of S-9. These observations provide a base line biocompatibility and toxicity data on LONP. The current findings will also be useful in defining standards for nanoparticle containing devices.
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Stevia rebaudiana Bertoni leaves have a long history of use as an abundant source of sweetener. The aqueous extract of stevia leaves and the predominant constitutes steviol glycosides have been intensively investigated. However, rare studies provided toxicological evaluation of bioactive components in the polar extract regarding their safety on human health. This study aimed to evaluate the toxicity of ethanolic extract of Stevia rebaudiana Bertoni leaves through a battery of in vitro and in vivo tests. Negative results were unanimously obtained from bacterial reverse mutation assay, mouse bone marrow micronucleus assay and mouse sperm malformation assay. Oral administration at dietary levels of 1.04%, 2.08% and 3.12% for 90 days did not induce significant behavioral, hematological, clinical, or histopathological changes in rats. Significant reduction of cholesterol, total protein and albumin was observed in female animals only at high dose level. The results demonstrated that Stevia rebaudiana Bertoni leaves ethanolic extract, which is rich in isochlorogenic acids, does not possess adverse effects through oral administration in this study. Our data provided supportive evidence for the safety of Stevia rebaudiana Bertoni leaves that may potentially be used in functional foods as well as nutritional supplements beyond sweetner. | non-battery |
Crystalline LiCoO2 nano-particles for thin film battery were synthesized and deposited by aerosol flame deposition (AFD). The aqueous precursor solution of the lithium nitrate and cobalt acetate was atomized with an ultrasonic vibrator and subsequently carried into the central tube of the torch by flowing dry Ar gas. LiCoO2 were formed by oxy-hydrogen flame and deposited on a substrate placed in a heating stage. The deposited soot film composed of nano-sized particles was subsequently consolidated into a dense film by high temperature heat treatment at 500–800°C for 5h and characterized by SEM, XRD, and Raman spectroscopy. The crystalline carbonates and oxide were first formed by the deposition and the subsequent heat treatment converted those to LiCoO2. The FWHMs of the XRD peaks were reduced and their intensity increased as the heat treatment temperature increased, which is due to improved crystallinity. When judged from the low enough cation mixing and well-developed layered structure, it is believed that the LiCoO2 film satisfied the quality standard for the real application. SEM measurements showed that LiCoO2 were nano-crystalline structure with the average particle size <70nm and the particle size increased with the increase of heat treatment temperature. The thickness of thin film LiCoO2 before the consolidation process was about 15μm and reduced to about 4μm after sintering. | battery |
Small renewable energy solutions such as solar home lighting system (SHLS) provide reliable electricity supply to off-grid bottom-of-pyramid (BoP) households and thereby improve status of living. Commercial SHLS employs polycrystalline silicon photovoltaic (PV) and flooded lead–acid battery technologies for energy generation and energy storage, respectively. Flooded lead–acid battery is a 150-year-old, mature and inexpensive energy storage technology but has a short lifetime. In SHLS, flooded lead–acid battery requires replacement every 4–5 years and can cost up to 70% of the total cost over the 20 years lifetime of the system. In this paper, seven advanced lithium-ion battery chemistries were evaluated as a potential replacement for flooded lead–acid battery in SHLS using HOMER microgrid software. Three lithium-ion battery chemistries – NCA, LFP and LFP/LTO – were found to be viable alternatives based on economic and performance metrics. The three lithium-ion battery based SHLS showed comparable initial capital cost to that of the commercial SHLS but provided significant advantage over the system lifetime as no/fewer battery replacements were required, which resulted in a total net present cost (TNPC) that was as low as 45% of the commercial SHLS. Price of lithium-ion battery technology is decreasing at 8–16% annually in real terms and the cost advantage of SHLS based on lithium-ion battery is expected to increase significantly in the future. | battery |
Metal-based composites are under investigation as possible negative-electrode materials in lithium-ion batteries. In this paper, we present a new composite material constituted of antimony particles dispersed on graphite. The antimony–graphite compound is prepared by antimony pentachloride reduction with KC8 in tetrahydrofuran. The high reversible capacity of 420 mAh g−1 and the good stability suggest that the association of antimony with graphite allows not only to improve reversible capacity but also to prevent the metal from particle pulverisation generally occurring during lithium alloying. | battery |
Rechargeable nonaqueous Li-air batteries are attracting much attention due to their far higher theoretical energy density than lithium-ion batteries. However, Li-air batteries suffers from poor round-trip efficiency, low rate capability and poor cycle life. To reduce charge overpotentials by understanding reaction mechanism and to operate in ambient air instead of pure oxygen are prerequisites to realization of practical Li-air batteries. Here, we demonstrate a practical Li-air battery using Mo2C/CNT as a potential promoter with high round-trip efficiency (∼80%) and improved cycling performance (40 cycles) because Mo2C stabilizes the intermediate species from reduction of both O2 and CO2. The stabilization via formation of Mo-O bonds prevents further reduction and disproportionation of intermediate species to generate crystalline Li2O2 and Li2CO3, thus reducing the charge overpotentials normally caused by the decomposition of crystalline Li2O2 and Li2CO3. In all, this work provides improved understanding of the general role of solid promoters and enables rational design of promoters towards practical Li-air batteries. | battery |
In an all-vanadium redox flow battery (VRFB), a shunt current is inevitable owing to the electrically conductive electrolyte that fills the flow channels and manifolds connecting cells. The shunt current decreases the performance of a VRFB stack as well as the energy conversion efficiency of a VRFB system. To understand the shunt-current loss in a VRFB stack with various designs and operating conditions, a mathematical model is developed to investigate the effects of the shunt current on battery performance. The model is calibrated with experimental data under the same operating conditions. The effects of the battery design, including the number of cells, state of charge (SOC), operating current, and equivalent resistance of the electrolytes in the flow channels and manifolds, on the shunt current are analyzed and discussed. The charge-transfer efficiency is calculated to investigate the effects of the battery design parameters on the shunt current. When the cell number is increased from 5 to 40, the charge transfer efficiency is decreased from 0.99 to a range between 0.76 and 0.88, depending on operating current density. The charge transfer efficiency can be maintained at higher than 0.9 by limiting the cell number to less than 20. | battery |
The effects of vinylene carbonate-based and prop-1-ene-1,3-sultone-based electrolyte additives on the cycling behavior of Li[Ni1/3Mn1/3Co1/3]O2/graphite pouch type cells at elevated temperature have been systematically studied. Capacity fade during cycling, charge-transfer resistance before and after cycling as well as gas evolution during formation and also during cycling were examined and compared. For vinylene carbonate-based additive blends, only 3% vinylene carbonate, 2% vinylene carbonate+1% 1,3,2-dioxathiolane-2,2-dioxide+1% tris(trimethylsilyl) phosphite or 2% vinylene carbonate + 1% methylene methyl disulfonate + 1% tris(trimethylsilyl) phosphite showed less capacity fade than 2% vinylene carbonate alone. Cells with all of these vinylene carbonate-based electrolyte additive blends lost more than 20% of their initial capacity after ∼1000 cycles at 55 °C and all the vinylene carbonate-based cells swelled more than 10% of their initial volume during this test. Cells containing all prop-1-ene-1,3-sultone-based additive blends generally produced much less gas than the vinylene carbonate-based blends. Many cells containing prop-1-ene-1,3-sultone-based additive blends lost less than 20% of their initial capacity after 1000 cycles. Moreover, the impedance of these prop-1-ene-1,3-sultone-based electrolytes decreased after long-term cycling. These results suggest that prop-1-ene-1,3-sultone-based electrolytes are more useful than vinylene carbonate-based electrolytes at high temperatures in Li[Ni1/3Mn1/3Co1/3]O2/graphite cells. | battery |
Nitrogen doped carbon tubes (N-CT) of dia 100nm are prepared by carbonization of polyaniline tubes and selenium impregnation into N-CT is carried out by melt diffusion process. The N-CT possess micropores and small mesopores that assist in trapping Se. Interestingly, Se absorption in micropores creates steric hindrance for the formation of long chain polyselendes during electrochemical discharge and hence leads to direct formation of Li2Se. Whereas, the small mesopores ensure proper electrode-electrolyte contact rendering good rate capability. Due to the presence of small mesopores a small quantity of polyselenides may be formed during initial cycles, however the nitrogen present in the carbon matrix can help in controlling their dissolution by creating polarity. Hence, it is observed here that after few initial cycles, the multistep reaction between Li and Se has changed to a single step. This is supported by in-situ electrochemical analysis like differential capacity (dQ/dV) plots, cyclic voltammetry impedance analysis and ex-situ UV–vis spectroscopy. | battery |
To enable the efficient utilization of energy carriers and the successful integration of renewable energies into energy systems, building energy management systems (BEMS) are inevitable. In this article, we present a modular BEMS and its customizable architecture that enable a flexible approach towards the optimization of building operation. The system is capable of handling the energy flows in the building and across all energy carriers as well as the interdependencies between devices, while keeping a unitized approach towards devices and the optimization of their operation. Evaluations in realistic scenarios show the ability of the BEMS to increase energy efficiency, self-consumption, and self-sufficiency as well as to reduce energy consumption and costs by an improved scheduling of the devices that considers all energy carriers in buildings as well as their interdependencies. | battery |
Developmental language disorder (DLD, also called specific language impairment, SLI) is a common developmental disorder comprising the largest disability group in pre-school-aged children. Approximately 7% of the population is expected to have developmental language difficulties. However, the specific etiological factors leading to DLD are not yet known and even the typical linguistic features appear to vary by language. We present here a project that investigates DLD at multiple levels of analysis and aims to make the reliable prediction and early identification of the difficulties possible. Following the multiple deficit model of developmental disorders, we investigate the DLD phenomenon at the etiological, neural, cognitive, behavioral, and psychosocial levels, in a longitudinal study of preschool children. | non-battery |
The performance of an undivided flow battery based on the Pb(II)/Pb and PbO2/Pb(II) couples in aqueous methanesulfonic acid as a function of state of charge, current density, electrolyte flow rate and temperature is reported. In addition, it is demonstrated that the cell chemistry can be rebalanced after multiple charge/discharge by allowing the excess lead metal deposited at the negative electrode to react with oxygen on open circuit. | battery |
Nickel-rich layered oxide cathodes are at the forefront of the development of automobile batteries. The authors report an atomic and microstructural engineering design for a Li[Ni0.90Co0.09Ta0.01]O2 cathode that exhibits outstanding long-term cyclability and high energy at full depth of discharge in full cells.
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Porous TiNb2O7 nanospheres comprised of nanoparticles have been synthesized with the assistance of block copolymer P123 (EO20PO70EO20). Such porous TiNb2O7 nanospheres, with diameter of 500nm, exhibit a BET surface area of 23.4m2/g and pore volume of 0.155cm3/g. As the anodes for lithium-ion batteries, the TiNb2O7 nanospheres present a reversible capacity of 160mAh/g after 10000 cycles at 5C with a capacity loss of only 0.0033% per cycle, and good rate performance of 167mAh/g at 50C. Furthermore, the TiNb2O7 materials still maintain the morphology of nanospheres and the porous structure even after 10000 cycles. | battery |
Li-rich cathode materials are potential candidates for next-generation Li-ion batteries. However, they exhibit a large voltage hysteresis on the first charge/discharge cycle, which involves a substantial (up to 1 V) loss of voltage and therefore energy density. For Na cathodes, for example Na0.75[Li0.25Mn0.75]O2, voltage hysteresis can be explained by the formation of molecular O2 trapped in voids within the particles. Here we show that this is also the case for Li1.2Ni0.13Co0.13Mn0.54O2. Resonant inelastic X-ray scattering and 17O magic angle spinning NMR spectroscopy show that molecular O2, rather than O22−, forms within the particles on the oxidation of O2− at 4.6 V versus Li+/Li on charge. These O2 molecules are reduced back to O2− on discharge, but at the lower voltage of 3.75 V, which explains the voltage hysteresis in Li-rich cathodes. 17O magic angle spinning NMR spectroscopy indicates a quantity of bulk O2 consistent with the O-redox charge capacity minus the small quantity of O2 loss from the surface. The implication is that O2, trapped in the bulk and lost from the surface, can explain O-redox. | battery |
Determining cutting force equations and the associated specific cutting pressures require a relatively large number of orthogonal cutting tests. These tests need to cover wide ranges of cutting speeds, feeds, and rake angles. Given the inherent variation of the rake angle and the tangential velocity over the drill's cutting lip, this work introduces a methodology for extracting these cutting force coefficients by performing a few drilling experiments on pre-drilled pilot holes. First, the contributions of the ploughing forces acting on the lip and margin are determined. Subtracting these edge forces from the measured total values, torque and thrust cutting forces and the corresponding cutting pressure distributions along the lip are derived. These distributions are then used to produce equations that estimate cutting force coefficients over a wide range of cutting parameters. The coefficients determined in this work from drilling experiments in Aluminium 6061-T6 compare favorably with others generated from orthogonal cutting experiments reported in the literature. | non-battery |
Three-dimensional (3D) electrodes with freestanding feature represent the state-of-art electrode design for advanced lithium-ion batteries. Construction of 3D architectures for cathode materials, however, is still a great challenge. In this work, freestanding 3D LiCoO2 nanosheets assembled nanorod arrays are grown on carbon fabric via confined dissolution-recrystallization on the Co(CO3)1-x(OH)2x·nH2O nanowire arrays during hydrothermal treatment. The formed intermediate CoOOH nanosheets can catalyze the decomposition of H2O2 and the generated continuous oxygen bubble layer enables self-limiting dissolution-recrystallization. After final heat treatment at a low temperature of 380 °C, the obtained 3D hierarchy LiCoO2 nanorod arrays exhibit large specific capacity, excellent rate performance, and outstanding cycling stability when tested as cathode for aqueous lithium-ion batteries. It is found that the hydrothermally synthesized LiCoO2 sample without heat treatment still has some structure distortion with proton intercalation and Li+ occupancy at abnormal sites, which deteriorate its electrochemical performance. By using the 3D hierarchy LiCoO2 nanorod arrays as cathode, a flexible aqueous LiCoO2//LiTi2(PO4)3 lithium-ion battery device is successfully constructed, demonstrating superior rate performance and cycle performance. | battery |
Neuregulin 1 (NRG1), which has been implicated in the development of schizophrenia, is expressed widely throughout the brain and influences key neurodevelopmental processes such as myelination and neuronal migration. The heterozygous transmembrane domain Nrg1 mutant mouse (Nrg1 TM HET) exhibits a neurobehavioural phenotype relevant for schizophrenia research, characterized by the development of locomotor hyperactivity, social withdrawal, increased sensitivity to environmental manipulation, and changes to the serotonergic system. As only limited data are available on the learning and memory performance of Nrg1 TM HET mice, we conducted a comprehensive examination of these mice and their wild type-like littermates in a variety of paradigms, including fear conditioning (FC), radial arm maze (RAM), Y maze, object exploration and passive avoidance (PA). Male neuregulin 1 hypomorphic mice displayed impairments in the novel object recognition and FC tasks, including reduced interest in the novel object and reduced FC to a context, but not a discrete cue. These cognitive deficits were task-specific, as no differences were seen between mutant and control mice in spatial learning (i.e. RAM and Y maze) for both working and reference memory measures, or in the PA paradigm. These findings indicate that neuregulin 1 plays a moderate role in cognition and present further behavioural validation of this genetic mouse model for the schizophrenia candidate gene neuregulin 1. | non-battery |
This work investigates the influence of electrode preparation on the electrochemical behaviour of carbon-based supercapacitors. Studies were performed using the same activated carbon and polymer polyvynilidene fluoride (PVDF) in the same proportions (10 wt.% PVDF). Only the way in which these components were mixed was modified. The procedure for mixing the activated carbon and the polymer has a significant influence on the electrochemical behaviour of the electrode used in a supercapacitor, as this determines the surface area accessible to the electrolyte. The mixing procedure can be selected in order to ensure optimum performance of the electrode. The use of N-methyl-2-pyrrolidone (NMP) in the mixing procedure, the most common method reported in the literature, blocks a significant part of the porosity of the activated carbon, causing a decrease in capacitance. The addition of the polymer using one of the other methods studied reduces the accessible surface area to a lesser extent, although the use of ball milling causes a decrease in the size of the carbon particles which, in turn, increases the electrode resistance. | battery |
Physical activity has been consistently associated with enhanced quality of life (QOL) in older adults. However, the nature of this relationship is not fully understood. In this study of community dwelling older adults, we examined the proposition that physical activity influences global QOL through self-efficacy and health-status. | non-battery |
Poly-[1-methyl-3-(pyrrol-1-ylmethyl)pyridinium]chloride films on glassy carbon electrodes greatly increased the voltammetric peak currents of alizarin red S (ARS), which is an anthraquinone derivative. We propose that the adsorption sites of ARS in the polymer channel be divided into two different classes: the hydrophobic interfacial zone and the hydrated zone. The theoretical curve based on our proposed model well fits the experimental data points for the relationship between the ARS concentrations in the polymer film and in the immersing solution. The electrocatalytic effect produced by the polymer film is attributed to an effective extraction of ARS from very dilute solution (the partition coefficients on hydrophobic interfacial zones, K 1 is 2.5×107, and that on hydrated zones, K 2 is 6.3×104 in 0.2 M H2SO4). A K 1/K 2 value of 400 means that the ion-exchange ability of ARS in the hydrophobic interfacial zone is much larger than that in the hydrated zone. Although anthraquinone-2,6-disulfonate and acid violet were strongly bound to the PMPP film, ARS can not been fixed to the polymer because of a weak binding force. Using our proposed model, the ion-exchange ability of PMPP film is controlled by both of electrostatic and hydrophobic interactions, but the adsorption ability changes with steric hindrance between the anionic species and polycationic films. | battery |
A core/shell type silicon/carbon nanotubes (Si/CNTs) composite is prepared and its anodic performance in lithium secondary batteries is examined. For the growth of CNTs, a Ni catalyst is loaded on a Si surface by electroless deposition. The growth is performed by chemical vapour deposition at 600°C using C2H2/H2 but is successful only on smaller and thinner Ni deposits. This is probably due to an easier transformation to small droplets that initiate the growth reaction. The anodic performance of a Si/CNTs composite electrode is superior to that observed with bare Si and Si/CNTs mixed electrodes. This beneficial feature is ascribed to the conductive buffering role of the CNTs layer. It is likely that the void space and the flexible characteristics in the CNTs buffer layer on the Si surface allow volume expansion of the Si core without severe electrode swelling. Because of this, the electric conductive network made among Si particles, carbon network and current-collector is well maintained, which reduces the charge-transfer resistance. | battery |
We report the effects of electrode thickness, cathode particle size and morphology, cathode carbon coating matching ratio and laminate structure on the electrochemical characteristics of nanosized Li4Ti5O12–LiMn2O4 batteries. We show that a correct adjustment of these parameters resulted in significant improvements in power capability and cycle-life of such devices, making them competitive, low-cost and safe battery chemistry for next generation Li-ion batteries. In addition, Li4Ti5O12 reversible specific capacity beyond three Li-ions intercalation is reported. | battery |
This paper presents the performances of 4cm2 supercapacitors cells assembled with 200μm thick active material films composed with activated carbon and carbon nanotubes mixture in organic electrolyte. Galvanostatic and electrochemical spectroscopy impedance measurements have been carried out. Galvanostatic measurements show that both internal resistance and specific capacitance decrease when the carbon nanotubes content increases in the active material. With 15% of carbon nanotubes, the internal resistance is 0.65Ωcm2 and the specific capacitance is 90Fg−1 measured at 20mAcm−2. This performances remain stable during 10,000 cycles. The characterization of the frequency behavior was made by Electrochemical Impedance Spectroscopy. For 15% of CNTs content in the active material, the relaxation time (φ = −45°) is divided by 3 as compared to a supercapacitor using pure activated carbon electrodes. | battery |
In the current study, a nanoscale perovskite SrFeO3 (SrFNPs) was synthesized by a rapid microwave-assisted co-precipitation method and characterized by X-ray diffraction, Fourier transform-infrared spectroscopy, scanning electron microscopy, Energy dispersive X-ray, and vibrating sample magnetometer techniques. Modified glassy carbon electrode with Pt nanoparticles (PtNPs), functionalized carbon nanotubes (CNTs), and SrFNPs as multifunctional catalyst is prepared and its catalytic activity toward methanol oxidation is investigated. Based on the electrochemical studies, a PtNPs–CNTs–SrFNPs nanocomposite was shown a considerable activity for methanol oxidation in comparison of PtNPs, PtNPs–CNTs, and PtNPs–SrFNPs. A direct methanol fuel cell was designed, assembled, and tested with suggested PtNPs–CNTs–SrFNPs nanocomposites under several different conditions. The effect of some experimental factors such as temperature, methanol concentration, and flow rate as well as NaOH concentration on electrical performances of fuel cell were studied and optimized.
| battery |
Hierarchical structured Li4Ti5O12, assembling from randomly oriented nanosheets with a thickness of about 10–16nm, is fabricated by a facile hydrothermal route and following calcination. It is demonstrated that the as-prepared sample has good cycle stability and excellent high rate performance. In particular, the discharge capacity of 128mAhg−1 can be obtained at the high current density of 2000mAg−1, which is about 87% of that at the low current density of 200mAg−1 upon cycling, indicating that the as-prepared sample can endure great changes of various discharge current densities to retain a good stability. In addition, the pseudocapacitive effect based on the hierarchical structure, also contributes to the high rate capability of Li4Ti5O12, which can be confirmed in cyclic voltammograms. | battery |
An analytical solution for the voltage distribution in one-dimensional porous electrode subjected to cyclic voltammetric (CV) conditions was developed by considering the resistivity of both electrode and electrolyte. Voltage distribution inside the electrode as a function of dimensionless distance was generated at different electrode phase resistances. The analytical solution of voltage distribution for cyclic voltammetric conditions was employed in deriving the charging currents. Capacitance studies were conducted on carbons derived from catechol-formaldehyde gels prepared at pH conditions of 3, 6, and 7.5 in 30wt.% H2SO4 electrolyte using CV and constant current charge/discharge studies. Charging currents derived from voltage distribution were fitted with experimental anodic part of CV curves and equivalent series resistance (ESR) was generated. Thus, generated ESR values were compared with that obtained using constant current charge–discharge curves. The model fitted resistance values matched closely with resistance values obtained from galvanostatic constant current charge–discharge method. | battery |
Case-based reasoning system (CBR) has been widely applied to the issue of market segmentation. Most of previous studies focused on dividing customers into two groups. Consequently, traditional voting method used for two groups in CBR would become inappropriate when one would like to divide customers into three groups through some segmentation variable. In this paper, a new voting method called 3NN+1 is proposed to bridge the gap. To make the inference of the 3NN+1 based CBR system more efficient, the features and instances (or cases) for reasoning is selected simultaneously by means of genetic algorithms. This new system is applied to a real case of notebook market to demonstrate its usefulness for market segmentation. From the results of the real case, it shows that the system would be valuable to enterprises, when dividing customers into three groups in compliance with their purchasing behaviors for developing marketing strategies. | non-battery |
Methacrylic-based thermo-set gel-polymer electrolyte membranes obtained by a very easy, fast and reliable free radical photo-polymerisation process and reinforced with microfibrillated cellulose particles are here presented. The morphology of the composite electrolytes is investigated by scanning electron microscopy and their thermal behaviour (characteristic temperatures, degradation temperature) are investigated by thermo-gravimetric analysis and differential scanning calorimetry. The composite membranes prepared exhibit excellent mechanical properties, with a Young's modulus as high as about 80MPa at ambient temperature. High ionic conductivity (approaching 10−3 Scm−1 at 25°C) and good overall electrochemical performances are maintained, enlightening that such specific approach would make these hybrid organic, cellulose-based composite polymer electrolyte systems a strong contender in the field of thin and flexible lithium based power sources. | battery |
Magnetron-sputtered iron films were potentiodynamically anodized at two different sweep rates to 50V in an ethylene glycol electrolyte containing ammonium fluoride and water. At a high sweep rate of 1.0Vs−1, a barrier-type anodic film was formed even though the current efficiency was as low as ∼50%. In contrast, a nanoporous anodic film developed at a low sweep rate of 0.05Vs−1, and the film-formation efficiency reduced to 37%. The main part of the anodic films consists of iron (III) hydroxyfluoride with a thin inner layer composed of FeF3. The inner fluoride layer is formed owing to the faster inward migration of fluoride ions compared to that of the oxygen species. During immersion or re-anodizing of the iron specimen with an approximately 100-nm-thick, barrier-type anodic film at and below 15V, thinning of the anodic film proceeded uniformly and film dissolution was enhanced by applying an electric field. The impact of the electric field on film formation and dissolution is discussed. | battery |
The 1×1 magnesium octahedral molecular sieve (Mg-OMS-7), utilizing as cathode material in aqueous rechargeable magnesium ions batteries, is synthesized by a simple one-step hydrothermal method. Meanwhile, by changing the concentrations of H2SO4, the Mg-OMS-7 materials with controllable size and shape are obtained. To check the structure and morphology, the host materials are measured by X-ray power diffraction, scanning, transmission and high-resolution transmission electron microscopy. The electrochemical reaction mechanism is examined by cyclic voltammetry and X-ray photoelectron spectroscopy. The Mg-OMS-7 changes the morphology from micro-rugby to nano-club by controlling the concentrations of H2SO4. The nano-club Mg-OMS-7 which obtained by the 1.6moldm−3 H2SO4 owns a more uniformly distribution and smaller size, which provides the shorter route for magnesium ions insert/deinsert into/from the lattice of host material and exhibits the better rate ability and cycle performance. The initial discharge capacity of this electrode can obtain 283.1mAhg−1 at the current density of 10mAg−1 in the 0.2moldm−3 Mg(NO3)2 aqueous electrolyte and the specific capacity retention rate is 94.1% after cycling 200cycles at 100mAg−1 in the 0.5moldm−3 Mg(NO3)2 electrolyte. | battery |
For the first time, cycling capability and life analysis of the FeSb2/Na battery are tested. Thanks to an appropriate carboxymethyl cellulose/carbon formulation, this electrode exhibits excellent electrochemical performances as negative electrode material for Sodium-Ion Batteries (SIB), sustaining a reversible capacity exceeding 540 and 440 mAh/g over more than 130 cycles at a current of 36 and 300 mA/g, respectively. Such performances overtake those of Sb in terms of cyclability under high rate, one of the best negative electrodes reported to date for SIB. In situ X-ray diffraction and low temperature Mössbauer spectroscopy analyses indicate that the reaction mechanism of the first sodiation of FeSb2 is based on a conversion reaction, leading to the formation of a very efficient Na3Sb/metallic Fe0 nanosized electrode with an excellent capacity retention at relatively high rate. The reaction mechanism after the first discharge is based on a reversible alloying reaction (2Na3Sb ↔ 2Sb + 6Na), where iron is no more involved. The role of Fe appears however to be crucial in the excellent cycling performances, likely due to the increase of the electronic conductivity brought both by its nanosized nature and its homogenous distribution in the electrode. | battery |
In this paper, single-phase pyrite with different particle sizes is prepared by hydrothermal method with the reactants of Na2S, S, and FeSO4. Compared with natural pyrite powder, synthesized pyrite nanocubes with small particle sizes and fine distribution have lower resistance, higher specific capacity and power density during the discharging process. The enlarging contacting surface area of pyrite with electrolytes will reduce the concentration polarization caused by the discharging current and improve the utilization efficiency of the pyrite materials. When pulse currents are loaded, compared with natural pyrite single-cell thermal battery, synthetic ones have smaller voltage drops and higher power density during the pulse discharging process. Influences of particle sizes on the thermal stability of the pyrite powders have also been investigated. | battery |
Background: Memory dysfunction among healthy relatives of patients with schizophrenia suggests that genetic liability to the disorder can also be manifested as cognitive impairment. This study was designed to further elucidate the nature of the memory dysfunction being transmitted. Method: Memory function was assessed in 62 schizophrenic patients, 98 of their healthy relatives and 66 controls. Material-specific immediate/delayed recall and percentage retention were investigated using the Logical Memory and Visual Reproduction tests of the Wechsler Memory Scale (WMS). A third subtest of the WMS, the Associate Learning and a visual analogue of it, the Abstract Paired Associates, were used to measure verbal and visual learning. Current general intellectual function was assessed using a five-subtest short-form of the Wechsler Adult Intelligence scale—Revised (WAIS-R). Results: Schizophrenic patients performed significantly worse than controls on nearly all measures. Their relatives also showed significant deficit on the immediate and delayed recall of the Logical Memory, immediate recall of the Visual Reproduction, and the Abstract Paired Associates tests. Logical memory was substantially more impaired than the other measures for both patients and relatives. The deficit in immediate recall of the Logical Memory remained significant even after excluding those relatives with an Axis I diagnosis and schizotypal personality disorder. These findings were despite the relatives having an equivalent level of general intellectual function to that of controls. Conclusion: Familial, presumed genetic, liability to schizophrenia may be expressed as dysfunction in verbal memory. | non-battery |
Increasing the average Ni content and extending the working voltage are effective approaches to enhancing the reversible capacity of Li[Ni1−x−yCoxMny]O2 layered oxide cathode materials. However, these would cause severe structural instability and rapid capacity fade upon cycling. In order to address this issue, Al3+ modified novel progressive concentration gradient material Li[Ni0.7Co0.13Mn0.17]O2 is successfully prepared, which maximizes the average Ni content as well as the surficial and structural stability at high cut-off voltage of 4.5 V, attributing to the progressively accelerated transition metals evolution rates from core to surface of the spherical particles and the Al3+ suppressed high-voltage phase transition. Consequently, superior reversible capacity of 206.1 mA h g−1 at 0.1C and capacity retention of 95.7% after 50 cycles at 0.5C rate are obtained, providing skilful approach to obtain promising high-performance cathode materials with both high energy density and long calendar life to satisfy the growing demands of future electric vehicles. | battery |
Objective. To identify the features of cognitive impairments (CI) in patients with alcoholic (AE) and dyscirculatory (DE) encephalopathies. Materials and methods. The study included 32 patients with DE and 30 with AE. Along with clinical observations, patients underwent computerized electroencephalography (EEG), recording of cognitive event-related potentials, and neuropsychological testing. Results and conclusions. The pathologies studied here showed both common and distinct signs in the clinical picture, in the emotional-personality domain, and impairments to cognitive processes. Common features of encephalopathies of different etiologies were CI and asthenic syndrome; AE was characterized by hyposthenic and DE by mixed (hyper- and hyposthenic) syndromes. The EEG showed that changes in bioelectrical activity in DE were predominantly located in the occipital-parietal areas of the cortex, while in AE they were located in the temporal and occipital-parietal areas. CI in DE and AE consisted of disorders to categorial thinking, long-term memory, reciprocal coordination, and digital gnosis, pointing to dysfunction of the frontal and parietal lobes of the left hemisphere, hippocampus, and corpus callosum. The indexes of the δ, β1, and β2 rhythms were discriminating features of CI in AE and DE. | non-battery |
This paper presents the optimal mapping of hybrid energy systems, which are based on wind and PV, with the consideration of energy storage and backup diesel generator, for households in six locations in the South-South geopolitical (SS) zone of Nigeria: Benin-city, Warri, Yenagoa, Port Harcourt, Uyo and Calabar. The optima hybrid energy systems are able to meet 7.23 kWh/day household's electrical energy demand. The hybrid energy system for each of the locations was optimally obtained based on HOMER software computation and TOPSIS multi-criteria decision-making algorithm that considers technical, economic, environmental, and sociocultural criteria. Wind energy potential was conducted for the six locations using the Weibull distribution function; the wind speed ranges between 3.21 and 4.19 m/s at 10 m anemological height. The wind speeds and the wind characteristics were extrapolated for 30 m and 50 m hub heights. The solar resource potentials across the six locations are also presented – ranges between 4.21 and 4.71 kWh/m2/day. The best hybrid system for the locations in Benin-city, Yenagoa and Port Harcourt is the Diesel generator-PV-Wind-Battery system; whereas the best hybrid system for the locations in Warri, Uyo and Calabar is the PV-Wind-Battery system. The hybrid systems in Benin-city, Yenagoa and Port Harcourt emit CO2, only 8.47%, 15.02% and 14.09% of the business as usual (the diesel generator). The payback time ranges between 3.7 and 5.4 years, using 0.893 US$/kWh cost of energy obtained for the business as usual. The cost of energy of the hybrid systems ranges between 0.459 and 0.562 US$/kWh, which compares well with available data in the public domain. The design parameters of the optima hybrid energy systems are also presented. The methodology presented here will serve as a design tool for renewable energy professionals. | battery |
Current technologies that provide climate control in the transportation sector are quite inefficient. In gasoline-powered vehicles, the use of air-conditioning is known to result in higher emissions of greenhouse gases and pollutants apart from decreasing the gas-mileage. On the other hand, for electric vehicles (EVs), a drain in the onboard electric battery due to the operation of heating and cooling system results in a substantial decrease in the driving range. As an alternative to the conventional climate control system, we are developing an adsorption-based thermal battery (ATB), which is capable of storing thermal energy, and delivering both heating and cooling on demand, while requiring minimal electric power supply. Analogous to an electrical battery, the ATB can be charged for reuse. Furthermore, it promises to be compact, lightweight, and deliver high performance, which is desirable for mobile applications. In this study, we describe the design and operation of the ATB-based climate control system. We present a general theoretical framework to determine the maximum achievable heating and cooling performance using the ATB. The framework is then applied to study the feasibility of ATB integration in EVs, wherein we analyze the use of NaX zeolite–water as the adsorbent–refrigerant pair. In order to deliver the necessary heating and cooling performance, exceeding 2.5kWh thermal capacity for EVs, the analysis determines the optimal design and operating conditions. While the use of the ATB in EVs can potentially enhance its driving range, it can also be used for climate control in conventional gasoline vehicles, as well as residential and commercial buildings as a more efficient and environmentally-friendly alternative. | battery |
This article presents a preliminary study of the measurement of local current density in all-vanadium redox flow batteries. Two batteries are designed and manufactured in this study, and the experimental results are compared. In the first cell, the current collector is divided into 25 segments, and the flow field plate is not segmented, whereas in the other cell, the flow field plate is segmented. The effects of the electrolyte flow rate on the battery efficiencies and the local current density variation are investigated. The experimental results show that the current density near the outlet significantly decreases when the discharge capacity approaches zero. In addition, the battery has a larger discharge depth at a higher electrolyte flow rate. | battery |
In this study, several emerging compounds of concern in waste water are identified and discussed in relation to data available on their sources and mass flows in urban waters. In most western European situations, the highest contributions to the mass flow of xenobiotics to the urban water cycle stems from household and services applications (e.g. personal care compounds, pharmaceuticals, steroid hormones, flame retardants, fluorinated detergents etc.) as well as building and constructing environments (e.g. flame retardants, plasticizers, UV-blockers and biocides). The contribution from industrial point sources such as incineration industries e.g. coal, tar, steel and gas production (such as PAHs, PCBs, dioxins, etc.) and chemical industries are decreasing in relevance in terms of input and are hence currently of more local relevance only. In relation to identified compounds, this paper considers current data availability and its use in a range of management strategies for the mitigation or controlling of xenobiotics ‘at source’. However it also identifies major knowledge gaps relating to the behaviour and fate of organic pollutants in various sectors of the urban water cycle including stormwater management, bank- and soil infiltration as well as underground and soil passage of polluted waters. It is also discussing the major sources of a range of current day urban pollutants. The paper considers the sources of emerging pollutants in a qualitative way. | non-battery |
The processes occurring in aprotic electrolyte on a lithium electrode in the steady state conditions and under polarization are studied using the method of electrochemical noise characterization. The evidence of the electro-chemical noise measurements on polarized lithium electrodes indicates that the discharge of lithium ions under cathodic polarization, as well as lithium anodic dissolution, is localized under the passive film rather than on its surface. An increase in the polarizing current results in local breakdown of the film; in this case, the electrochemical process emerges on the electrode surface affecting the character of potential fluctuations. The intensity of electrochemical noise significantly increases in the course of cathodic polarization with high currents. The reason is that lithium metal crystals, which are formed under the passive film, perforate the film, and dendrites grow on its surface. The method shows the dependence of electrochemical noise intensity on the nature of the electrolyte and establishes the correlation between the stability of the lithium electrode in the course of cycling and the intensity of fluctuations. This offers an opportunity of using the method of electrochemical noise for screening organic electrolytes for lithium batteries. | battery |
An implantable transducer for monitoring the flow of Cerebrospinal fluid (CSF) for the treatment of hydrocephalus has been developed which is based on measuring the heat dissipation of a local thermal source. The transducer uses passive telemetry at 13.56 MHz for power supply and read out of the measured flow rate. The in vitro performance of the transducer has been characterized using artificial Cerebrospinal Fluid (CSF) with increased protein concentration and artificial CSF with 10% fresh blood. After fresh blood was added to the artificial CSF a reduction of flow rate has been observed in case that the sensitive surface of the flow sensor is close to the sedimented erythrocytes. An increase of flow rate has been observed in case that the sensitive surface is in contact with the remaining plasma/artificial CSF mix above the sediment which can be explained by an asymmetric flow profile caused by the sedimentation of erythrocythes having increased viscosity compared to artificial CSF. After removal of blood from artificial CSF, no drift could be observed in the transducer measurement which could be associated to a deposition of proteins at the sensitive surface walls of the packaged flow transducer. The flow sensor specification requirement of +−10% for a flow range between 2 ml/h and 40 ml/h. could be confirmed at test conditions of 37°C.
| non-battery |
Three-component layer double hydroxides (LDHs) with varying compositions were produced by urea precipitation, and tested for their stability and electrochemical performance. Optimum initial metal ion concentrations in the starting solutions were established. Initial Al3+ concentration in the solution needs to be at least 0.015M for the LDH formation. From the solutions with initial Al3+ concentration of 0.025M, higher fractions of Ni2+ and Co2+ could be recovered. Co2+ could be incorporated at various levels without disturbing the LDH structure. LDH structure proved stable once it formed. Cyanate in the LDHs was dominantly N-bonded which contributed to the stability of the structure. Highest specific discharge capacity delivered by a LDH was 336mAh/g, which was about 30% higher than that by β-Ni(OH)2. LDHs reached their stable capacities at a lower rate than either β-Ni(OH)2 or the interstratified-Ni(OH)2 (α+β). The interstratified sample delivered the highest capacity compared to any of the tested compositions. | battery |
Methods of wet and dry crushing are adopted to experiment on spent lithium-ion batteries in this investigation. Particle size distribution is analyzed using the wet and dry screening respectively and fine crushed products are characterized by XRD, SEM and EDX. A comprehensive comparison of the characteristics between the two crushing methods indicates that the wet crushing results in an enrichment of each component in spent lithium-ion batteries to fine fractions because of the scouring action of water flow, which makes the fine products complicated and lost; while the dry crushing method can bring the selective crushing characteristics of spent lithium-ion batteries into full play, and in this case, lithium cobalt oxide and graphite electrode materials can be liberated from aluminum foil and copper foil without the overcrushing of the other components in spent lithium-ion batteries. Thus, the purity and dispersion of electrode materials can be improved to create favorable conditions for subsequent purification and regeneration. | battery |
Fossil fuel reserves are diminishing rapidly across the world, intensifying the stress on existing reserves day-by-day due to increased demand. Not only that, fossil fuels, presently contributing to 80% of world primary energy, are inflicting enormous impacts on environment. Energy sector has a key role in this regard since energy during its production, distribution and consumption is responsible for producing environmentally harmful substances. There is an urgent need for a quicker switch over of energy systems from conventional to renewables that are sustainable and can meet the present and projected world energy demand. Hydrogen, in the capacity of energy vector and storage medium is expected to be the optimum solution for intermittency and storage of energy produced by renewables. Within the context of Pakistan solar and wind power are two of the most promising renewables. In this article, the current energy consumption for Pakistan is presented and the issue of security of electrical energy supply is discussed. Furthermore, the prospects for a large-scale switch over to renewables are also addressed and the relevant economies and underpinning rationale provided. It has been found that solar energy is a much more economical choice for Pakistan as compared to wind energy-respective costs for solar and wind energy are (US cents/kWh) 20 and 77. This is due to the fact barring the four monsoon months, the average wind speed for the remaining 8 months does not cross an economic threshold. On the contrary, it was found that solar energy has a fairly stable and consistent availability. | battery |
SnSbAg0.1-reduced graphene oxide (RGO) composite anode materials are synthesised via chemical reduction. The structure, morphology and electrochemical performance of the synthesised materials are characterised by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy, Raman spectrometry, galvanostatic charge-discharge and cyclic voltammetry techniques. The large surface area, excellent conductivity and mechanical properties of the graphene reduce the agglomeration of alloy particles, buffer the stress of volume change and lower the powdering rate of particles, to enhance the inner transportation of Li+ between the electrodes and the electrolyte. The SnSbAg0.1-10%RGO composite anode materials exhibit a better electrochemical performance and cycle life than other alloy anode composite materials, demonstrating a capacity of 605.1mAhg−1 after 100 cycles and an average capacity attenuation rate of 0.16% from the 2nd cycle to the 100th cycle. The discharge capacity remain 538mAhg−1 after 200 cycles, retaining 74.3% of its capacity compared to the 2nd cycle and therefore exhibiting an excellent electrochemical performance | battery |
In order to enhance the electrochemical performance of the high capacity layered oxide cathode with a Ni-rich core and a concentration-gradient shell (NRC-CGS), we use a freeze drying method to coat Al2O3 layer onto the surface of NRC-CGS Li[Ni0.73Co0.12Mn0.15]O2 material. The samples are characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, charge-discharge measurements and electrochemical impedance spectroscopy. It is revealed that an amorphous Al2O3 layer of about 5nm in thickness is uniformly formed on the surface of NRC-CGS Li[Ni0.73Co0.12Mn0.15]O2 material by the freeze drying procedure. The freeze drying Al2O3-coated (FD-Al2O3-coated) sample demonstrates similar discharge capacity and significantly enhanced cycling performances, in comparison to the pristine and conventional heating drying Al2O3-coated (HD-Al2O3-coated) samples. The capacity decay rate of FD-Al2O3-coated Li[Ni0.73Co0.12Mn0.15]O2 material is 1.7% after 150 cycles at 55°C, which is 9 and 12 times lower than that of the pristine and HD-Al2O3-coated samples. The superior electrochemical stability of the FD-Al2O3-coated sample is attributed to the synergistic protection of CGS and high-quality Al2O3 coating that effectively protect the active material from electrolyte attack. The freeze drying process provides an effective method to prepare the high performance surface-coated electrode materials. | battery |
This paper reports a modeling methodology on the temperature dependence of the discharge behavior of a lithium-ion battery (LIB) in low environmental temperature. The discharge curves from the modeling for the discharge rates ranging from 0.5 C to 5 C under the low environmental temperatures of −20, −10 and 0 °C are compared with the experimental data in order to validate the two-dimensional modeling of the potential and current density distributions on the electrodes of an LIB cell as a function of the discharge time during constant-current discharge. The heat generation rates as a result of electrochemical reactions and ohmic heating are calculated to predict the temperature variations of the LIB as a function of the discharge time. The temperature variations obtained from the modeling agree well with the experimental measurements. | battery |
We present a convenient, low-cost strategy to fabricate one-dimensional, vertically oriented nanoporous assembly of SnO2 upon a Cu substrate as a potentially promising anode system for Na-ion batteries application. The major novelty of the fabrication stage resides in anodizing a Sn/Cu bilayer film that is created by a facile cold-rolling procedure amenable to large-scale production. The open, nanoporous morphology of SnO2 facilitates the diffusion of electrolytes to access the SnO2 surface. The high porosity of the SnO2 phase also provides large void space to effectively accommodate the volume expansion/contraction during sodiation/desodiation. As a result, the 1-D nanoporous SnO2 thus assembled on the Cu substrate can be directly used as an effective electrode system for Na-ion storage–without the need for additives, delivering a remarkable capacity of 326 mA h g−1 over 200 cycles at a current rate of 0.2 C. | battery |
Self-powered flexible inorganic electronic systems have been demonstrated to be the core of next-generation electronics due to their lightweight, thin, self-sustainable and biocompatible properties, which are applicable to cramped or corrugated surfaces. Many researchers have studied myriad approaches for high performance flexible electronics, e.g. energy harvesters, batteries, high-density memories, large-scale integration (LSI), light-emitting diodes (LEDs), and sensors. Moreover, innovative devices for in vivo biomedical applications have been demonstrated on curvilinear and isolated regions of human bodies for detecting or even treating diseases. This paper reviews recent advances in self-powered flexible inorganic electronics, covering material selection, mechanical design, fabrication method and their all-in-one integration on a single plastic substrate. | battery |
The increasing penetration of distributed generations (DGs) in the electrical system is causing a new system transient stability problem since most of DGs are characterized by low inertias and poor inherent damping. Measures such as application of storage unit and wind turbine crowbar protection have been proposed to enhance the transient performance of micro-grid. However, the increase in the number of micro-grid components also leads to changes in system critical clearing time (CCT) under fault conditions. This paper investigates the various features affecting the CCT of a micro-grid in an islanded mode. The result shows the traditional equation cannot be used to calculate the CCT and the wind turbine disconnection is the main reason causing the micro-grid collapse. The DG penetration level and the wind turbine crowbar protection insertion time can have significant impacts on the CCT value, and the CCT can be substantially increased by utilizing battery storage in the micro-grid. | battery |
La0.56−y Li0.33TiO3−3y F3y (y =0.017, 0.05) were prepared by a conventional solid-state reaction from a mixture of La2O3, LiCO3, TiO2, and 10% excess LiF. The variation of the lattice parameter with increase of y value in La0.56−y Li0.33TiO3−3y F3y was different from that in conventional lithium-lanthanum-titanate series perovskite oxides, La0.56−y Li0.33+3y TiO3. Bulk Li-ion conductivities of the La0.56−y Li0.33TiO3−3y F3y are higher than those of La0.56-y Li0.33+3y TiO3. Li-ion conductivity of La0.56−y Li0.33TiO3−3y F3y (y =0.017) was 2.30×10−3 Scm−1 at 30°C, which is, to our knowledge, one of the highest Li-ion conductivities in the oxide compounds. | battery |
We have used X-ray absorption fine structure (XAFS) in order to analyze the solid electrolyte interface (SEI) layer on the graphite anode and the LiCoO2 cathode in a lithium-ion battery. The SEI layers on the electrodes in the propylene carbonate (PC)-based electrolyte containing an ethylene sulfite (ES) additive were analyzed based on the different sulfur oxidation states with sulfur K-edge X-ray absorption near-edge structure spectroscopy (S K-edge XANES), X-ray photoelectron spectroscopy (XPS) and time-of-flight–secondary ion mass spectrometry (TOF–SIMS). The SEI layer on the graphite anode was mainly consisted of a sulfite-type compound with an inorganic film like Li2SO3 and an organic films like ROSO2Li. Furthermore, it was proven that the SEI layer on the graphite anode contained alkyl sulfide species. We also found that the SEI layer on the LiCoO2 cathode also contained alkyl sulfide species. | battery |
Electronic waste (e-waste) is the fastest growing solid waste stream worldwide and mostly ends up in developing countries where residents use primitive methods for recycling. The most infamous e-waste recycling town, Guiyu in Southeast China, has been recycling since the mid-1990s. E-waste contains several harmful chemicals, including lead (Pb), cadmium (Cd), chromium (Cr), and manganese (Mn). In 2011–12, the e-waste Recycling Exposures and Community Health (e-REACH) Study enrolled 634 pregnant women living in Guiyu and Haojiang, a control site, both in Shantou, China. The women completed a questionnaire and gave maternal blood, cord blood, and maternal urine, which were analyzed for Pb, Cd, Cr, and Mn. Maternal blood Pb, Cd, and Cr concentrations were significantly higher in Guiyu compared to Haojiang. In Guiyu, the geometric mean of Pb concentration in maternal blood was 6.66 µg/dL (range: 1.87–27.09 µg/dL) and was 1.74-fold greater than in Haojiang (95% CI: 1.60, 1.89). In cord blood, Pb concentration was 1.53-fold higher in Guiyu (95% CI: 1.38, 1.68). In maternal urine, Cd (ratio: 2.15, 95% CI: 1.72, 2.69) and Mn (ratio: 2.60, 95% CI: 2.04, 3.31) concentrations were significantly higher in Guiyu in comparison to Haojiang. In conclusion, pregnant women in Guiyu were at risk for increased exposure to heavy metals.
| non-battery |
The performances of direct ethanol fuel cells with different anode catalysts, different ethanol concentrations, and at different operating temperatures have been studied. The performance losses of the cell have been separated into individual electrode performance losses with the aid of a reference electrode, ethanol crossover has been quantified, and CO2 and acetic acid production have been measured by titration. It has been shown that the cell performance strongly depends on the anode catalyst, ethanol concentration, and operating temperature. It was found that the cathode and anode exhibit different dependences on ethanol concentration and operating temperature. The performance of the cathode is very sensitive to the rate of ethanol crossover. Product analysis provides insights into the mechanisms of electro-oxidation of ethanol. | battery |
In this study, neutral salt spray accelerated corrosion test of copper–aluminium composite under 0–125A DC current was carried out under 5% concentration. The effect of corrosion behaviour on copper–aluminium composite by DC current was carried out by a scanning electron microscope (SEM) with energy-dispersive spectroscopy (EDS), X-ray diffraction (XRD) patterns, X-ray photoelectron spectroscopy (XPS), weight-loss method and electrochemical analysis. The results show that the current can accelerate the corrosion rate. Meanwhile, the current temperature effect can reduce the corrosion rate. The current caused directional migration of ions resulting in different corrosion products on positive and negative poles of specimen, and the corrosion degree on the positive pole was more serious. The galvanic corrosion mechanism at the copper–aluminium interface is different from the pitting corrosion mechanism far away from the interface, and the latter is more affected by DC current.
| non-battery |
A new phase diagram of AB(CD)1/2 system, where A, B, C, and D represent Li2MnO3, LiMO2 (M=Co, Al, Cr, etc.), LiMnO2, and LiM′O2 (M′=Ni, Cu, Fe, etc.), respectively, was developed to express all compositions of solid solutions with layered manganese oxides. The phase diagram satisfied the theoretical manganese oxidation state of +4 over the whole triangle plane of the diagram and was expressed with a new design equation of Li [ M x ( L i 1 / 3 M n 2 / 3 ) y ( M ′ 1 / 2 M n 1 / 2 ) 1 − x − y ] O 2 . Solid solutions whose compositions were randomly chosen from the phase diagram were experimentally prepared using a direct synthetic method and were subjected to the examination of the structural and electrochemical properties. All the synthesized solid solutions had layered structure with maintaining +4 and showed one-step monotonous discharge curve shape without structural transformation during charge/discharge processes. | battery |
As a part of our on-going study on silver vanadium phosphorous oxides (Ag x V y O z PO4), we report here the first study of the electrochemical reduction of a low Ag/V ratio silver vanadium phosphorous oxide, Ag0.48VOPO4·1.9H2O. Reminiscent of Ag2VO2PO4 reduction, in situ formation of silver metal nanoparticles along with an associated increase in conductivity were observed after reduction of Ag0.48VOPO4·1.9H2O with 0.37 electron equivalents. However, in contrast to our lithium/Ag2VO2PO4 cells, our lithium/Ag0.48VOPO4·1.9H2O cells displayed an even higher voltage on discharge and a characteristic multi-plateau voltage profile, where vanadium reduction was the first reduction step. | battery |
Water-table depths were simulated using a numerical model with information on recharge from the last 48 years under different extraction policies. With this series of groundwater level data, groundwater level probability distribution functions were determined and extraction statistics were estimated by fitting time series models and by using the crossing theory. With this information, it has been possible to calculate the risk of being unable to supply groundwater demand because the results verify that only 67% of the water rights granted are able to be extracted on a sustained basis with a 90% exceedance probability. Furthermore, the results obtained demonstrate that the method is adequate for determining exceedance probabilities of groundwater flow.
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Tri(β-chloromethyl) phosphate (TCEP) and cyclohexyl benzene (CHB) had been studied synchronously as the additives of the lithium ion batteries to improve the high temperature and overcharge safety. The study group used the cyclic voltammetry and environment scanning electron microscopy (ESEM) to investigate the oxidize potentials of the TCEP and CHB at normal environment and 150°C and the surface characteristics of the positive electrode of the graphite/LiCoO2(063465) batteries before and after overcharge. The self-extinguishing time (SET) tests were carried out to measure the effect of additives on the electrolyte combustibility. The oven and overcharge tests and other electrochemical testing methods were performed to test the reliability of the protection provided by the TCEP and CHB of the high temperature and overcharge safety and the effect of the additives on the electrochemical performance. The results show that the oxidize potential of the TCEP is about 4.75V and the CHB about 4.6V at normal environment and the oxidize potential of the TCEP drops to 4V and CHB about 4.1V at 150°C; the TCEP has favorable effect on the self-extinguish time of the electrolyte; the surface of the LiCoO2 positive electrode after overcharge formed a layer of CHB polymer; when the content of both additives are over 5wt%, the batteries show improved safety through the oven tests of 150°C and can stand 1.3A (1C) and constant 10V overcharge tests; the adverse effect of TCEP and CHB on cycle performance of battery is relatively small. In sum, the cooperative use of these two additives can improve the safety of lithium ion battery greatly. | battery |
The effectiveness of silicon carbide (SiC) nanowires (NW) as electrode material for micro-supercapacitors has been investigated. SiC NWs are grown on a SiC thin film coated with a thin Ni catalyst layer via a chemical vapor deposition route at 950 °C. A specific capacitance in the range of ∼240 μF cm−2 is demonstrated, which is comparable to the values recently reported for planar micro-supercapacitor electrodes. Charge–discharge studies demonstrate the SiC nanowires exhibit exceptional stability, with 95% capacitance retention after 2 × 105 charge/discharge cycles in an environmentally benign, aqueous electrolyte. | battery |
Fe2O3-reduced graphene oxide (RGO) composites were successfully fabricated via a facile microwave-assisted reduction of graphite oxide in Fe2O3 precursor solution using a microwave system, and investigated as anode material for sodium ion batteries (SIBs). Their morphologies, structures and electrochemical performance were characterized by transmission electron microscopy, X-ray diffraction, Raman spectroscopy, cyclic voltammetry and electrochemical impedance spectroscopy, respectively. The results show that the RGO addition can enhance the electrochemical performance of Fe2O3-RGO composites. Fe2O3-RGO composite with 30wt.% RGO exhibits a maximum reversible capacity of 289mAhg−1 at a current density of 50mAg−1 after 50 cycles and excellent rate performance due to the synergistic effect between Fe2O3 and RGO. The high capacity, good rate capability and excellent cycle performance of Fe2O3-RGO composites enable them a potential electrode material for SIBs. | battery |
A model order reduction method is developed and applied to the solid-phase diffusion problem used in physics-based lithium ion cell models. The reduced order model is in the form of a state space model. Model identification is performed in the frequency-domain using the vector fitting method. The method allows the user to control the order of the model, the frequency band for model identification, and optionally a weight function to give a certain frequency band more weight. The model can be used for spherical and non-spherical particles. For spherical particles, the results from using the reduced order model are compared with those from analytical solutions, and excellent agreement is achieved using 3rd and 5th order models. When the approach is applied to non-spherical particles, the transfer functions need to be calculated numerically. Two methods, step response and complex exponential, are proposed to calculate the required transfer function. While the step response method is more suitable for low frequencies, the exponential method is more accurate for high frequencies. | battery |
The surface of LiCoO2 cathodes was coated with various wt.% of Al2O3 derived from methoxyethoxy acetate-alumoxane (MEA-alumoxane) by a mechano-thermal coating procedure, followed by calcination at 723K in air for 10h. The structure and morphology of the surface modified LiCoO2 samples have been characterized with XRD, SEM, EDS, TEM, BET, XPS/ESCA and solid-state 27Al magic angle spinning (MAS) NMR techniques. The Al2O3 coating forms a thin layer on the surface of the core material with an average thickness of 20nm. The corresponding 27Al MAS NMR spectrum basically exhibited the same characteristics as the spectrum for pristine Al2O3 derived from MEA-alumoxane, indicating that the local environment of aluminum atoms was not significantly changed at coating levels below 1wt.%. This provides direct evidence that Al2O3 was on the surface of the core materials. The LiCoO2 coated with 1wt.% Al2O3 sustained continuous cycle stability 13 times longer than pristine LiCoO2. A comparison of the electrochemical impedance behavior of the pristine and coated materials revealed that the failure of pristine cathode performance is associated with an increase in the particle–particle resistance upon continuous cycling. Coating improved the cathode performance by suppressing the characteristic structural phase transitions (hexagonal to monoclinic to hexagonal) that occur in pristine LiCoO2 during the charge–discharge processes. | battery |
There is increasing theoretical, clinical and research evidence for the role of perceived travma and personal charactheristics in trauma related psychological problems and disorders. Facing and working through psychosocial trauma is essentially difficult not only for the individuals suffered but also the professionals dealt with them. Strengths serve individuals best not when life is easy but when life is difficult (Park, Peterson & Seligman 2004). During challenging times, helping people to discover their strengths such as optimism, hope, humor, resilience, and meaning takes added importance for mental health professionals. Thus it is found that individuals who use their strengths more have been shown to have higher levels of self-esteem, self-efficacy, vitality, well-being (Linley, et.al., 2010; Govindji, and Linley, 2007) and also to be more effective in their growth (Rashid, 2008) after a traumatic exposure in their daily life. Focussing on strengths can provide the clinician a powerful perspective to understand individuals intact repertoires which can be effectively deal with troubles stimulates a very different discussion. The aim of the present study is to examine the relations between the perceived trauma, post traumatic embitterment disorder and strengtspotting abilities. The strengthspotting scale, post traumatic embitterment self rating scale and Beck anxiety inventory were administered to both in-patients in clinical setting and also health care professionals. The results were discussed in terms of traumatic intervention with positive psychology principals. Suggestions were presented and the need of multidisiplinary work emphasized for future research | non-battery |
As we have seen in earlier chapters, the strength of the ‘analog revival’ came as a surprise to most of the major instrument manufacturers, whose main and much delayed response was simply to reintroduce analog- style front-panel controls to some of their existing digital synthesizer designs. But for those manufacturers who did wish to offer some analogstyle product without the cost and potential unreliability of using genuine analog circuitry, the ‘virtual analog’ synthesizer became the obvious solution. | non-battery |
In this work, we report on star-shaped plasticizers with the various chain lengths of multi-armed oligo(ethylene oxide) in order to prevent the plasticizers from crystallizing and eventually to enhance the ionic conductivity at low temperature. The multi-armed plasticizers are compared with the linear ones in terms of the ionic conductivity of the polymer electrolytes using them. The ionic conductivity of the polymer electrolytes using the linear plasticizer abruptly decreases below 0°C, while the temperature dependence of the ionic conductivity of the polymer electrolytes based on the multi-armed plasticizers shows a typical Vogel–Tamman–Fülcher (VTF) relationship in the temperature range from −30 to 100°C. Such enhanced ionic conductivity at low temperature is because the multi-armed plasticizers are not crystallizing due to the branches or the multi-arms structure. The multi-armed plasticizers are found to be electrochemically stable up to 5.2V by cyclic voltammetry analysis, which means that they are electrochemically stable enough for the application in the lithium ion batteries. | battery |
State of charge (SOC) estimation is a key issue for battery management since an accurate estimation method can ensure safe operation and prevent the over-charge/discharge of a battery. Traditionally, open circuit voltage (OCV) method is utilized to estimate the stack SOC and one open flow cell is needed in each battery stack [1,2]. In this paper, an alternative method, extended Kalman filter (EKF) method, is proposed for SOC estimation for VRBs. By measuring the stack terminal voltages and applied currents, SOC can be predicted with a state estimator instead of an additional open circuit flow cell. To implement EKF estimator, an electrical model is required for battery analysis. A thermal-dependent electrical circuit model is proposed to describe the charge/discharge characteristics of the VRB. Two scenarios are tested for the robustness of the EKF. For the lab testing scenarios, the filtered stack voltage tracks the experimental data despite the model errors. For the online operation, the simulated temperature rise is observed and the maximum SOC error is within 5.5%. It is concluded that EKF method is capable of accurately predicting SOC using stack terminal voltages and applied currents in the absence of an open flow cell for OCV measurement. | battery |
Electroactive LiFePO4/C composite powders were successfully prepared by the microemulsion process under controlled conditions. A series of residual carbons on the surface of prepared LiFePO4 materials originating from the pyrolysis of various salt concentrations, Hydrophile-Lipophile-Balance (HLB) values, and structures of organic surfactants were characterized. All samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectral analysis, BET surface area, cyclic voltammetry (CV) and charge–discharge tests. The performance of the LiFePO4/C composite powders displayed a strong relationship between the emulsion conditions and structures of surfactants. Lower salt concentrations of the aqueous cores or a smaller HLB numbers cause the formation of small aqueous cores resulting in smaller particle sizes of LiFePO4/C composites after calcinating the cores. The molecular structures of surfactant affect the formation of micelle size and further influence the behavior of the LiFePO4/C composite. The OP-7 surfactant contains more branched structures on the lipophilic groups causing the formation of small aqueous cores and particle sizes of LiFePO4 after calcination of the cores. Small aqueous cores formed smaller particles with lower I D/I G values after pyrolysis yielding composites with higher discharge capacities. | battery |
This paper proposes an engineering design framework and methodology for building an energy semantic network (ESN) which helps to create and evaluate possible scenarios of energy system structure of buildings (energy generation, conversion, and conservation measures). The developed ESN does not only focus on building thermal performance (i.e. insulation materials, geometry, and dynamic behavior of building occupants) but also integrates energy resources, Hybrid Energy Supply Unit, and source-load interconnection. In other words, the developed ESN supports the design and evaluation of micro energy grid for building with various options of energy generation and conversion. Parameters identification of building energy system and their range is an important step to successfully develop energy optimization within buildings. The developed ESN generates the possible scenarios of energy generation and conversion for evaluation and optimization purposes. The structure of the ESN provides heterogeneous presentation of the classes with flexible architecture to modify, add, or delete significant energy classes. In addition, the ESN structure is designed to avoid non-realistic computational burden during simulations and evaluation. The methodology of generating the minimal possible scenarios is introduced. For validation purposes, the proposed algorithm is examined using case study of a mid-size house with different energy sources and thermal zones. The ESN of this case study is discussed, the possible scenarios of energy generation, conversion and load type are produced and their simulation and evaluation using five key performance indicators (KPIs) are introduced. | non-battery |
Orange juice (OJ) flavanones undergo limited absorption in the upper gastrointestinal tract and reach the colon where they are transformed by the microbiota prior to absorption. This study investigated the ability of two probiotic bacteria, Bifidobacterium longum R0175 and Lactobacillus rhamnosus subsp. Rhamnosus NCTC 10302 to catabolise OJ flavanones. | non-battery |
Searching for high-performance electrode materials with rapid charge/discharge and high cycling stability is pivotal to broaden the applications of lithium-ion batteries (LIBs). Herein, we report a simple nanochannel-confined synthesis technology of ultrafine Nb2O5 (<10 nm) nanoparticles encapsulated into carbon nanotubes (CNTs) hybrids for LIBs electrode materials. The three crystal forms of Nb2O5 can be respectively obtained simply by changing the temperature of thermal treatment. The ultrafine Nb2O5 nanoparticles dominated by the inner diameter of CNTs expose very high lithiation active sites. The fascinating nanostructure can also possess high structural stability with rapid electron transfer rate. Consequently, the orthorhombic Nb2O5/CNTs hybrids show a maximum specific capacity of 207 mAh g−1 at 0.1 A g−1, which can be maintained 170 mAh g−1 after 1000 cycles. More importantly, a specific capacity of 108 mAh g−1 can still be achieved even at 10 A g−1, much higher than CNTs surface loaded Nb2O5 nanoparticles hybrids. This work provides a channel-space confined synthesis insight for constructing novel electrode materials for high-rate and long-life LIBs. | battery |
The process optimization of nanocrystalline lithium manganate thin films (Li x Mn2O4; x =1.0–1.4) has been demonstrated by using a cost-effective solution growth technique. Films were first attempted with Pt–Si (Si/SiO2/TiO2/Pt) substrates but because of inter-diffusion of TiO2 buffer layer with Pt at higher annealing temperature, phase impure LiMn2O4 films were obtained. Phase pure films on the basis of XRD analysis were found on Pt substrate at specified growth parameters. The annealing temperature and annealing time were varied, the films annealed at 700°C for 2h were found to be the best films. The nanocrystalline nature of the films was revealed by the SEM micrographs and the surface morphology studied using AFM. Finally, the electrochemical properties (cyclic voltammetry and constant current measurements) of these films were analyzed using a home made three-electrode cell and Gamry Battery tester instrumentation. The formation of a prominent layer of fluoride species deposited over the cathode surface during the repeated cycling was revealed by XPS measurements. Further experiments are in progress on identifying the exact composition of these unwanted species. The formation of the Jahn-Teller active Mn3+ during electrochemical cycling was completely ruled out from the XPS analysis. Also the very consistent value of [Mn3+/Mn4+] ratio before and after electrochemical cycling on the surface of the film revealed good quality of the films. Finally, the formation of the fluoride layer was concluded as a passive layer that causes the initial capacity drop during first few cycles of the cell performance. | battery |
An in-situ and controllable redox deposition method has been applied to prepare binder-free MnO2 nanosheet array-decorated carbon paper as negative electrode for vanadium redox flow batteries (VRFB). Electrochemical performance of electrode depends on amount and uniform distribution of MnO2 on carbon paper, which were controlled by solution pH, KMnO4 concentration, and deposition time. Modified carbon paper (CPA-05-30) with a uniform MnO2 nanosheet coating layer was obtained in 0.05 M KMnO4 + 0.5 M H2SO4 solution for 30 min. CPA-05-30 presents the most excellent electrocatalytic performance for V3+/V2+ redox reaction. On CPA-05-30, charge transfer and diffusion processes for V3+/V2+ redox reaction are accelerated as a result of MnO2 nanosheet with high catalytic activity and excellent hydrophilcity. Therefore, loading MnO2 on carbon paper improves electrochemical activity V3+/V2+ redox reaction. Moreover, in charge-discharge test, the cell using CPA-05-30 as negative electrode shows higher discharge capacity and better capacity retention at 50 mA cm−2 for 50 cycles in comparison with pristine cell. It indicates that MnO2 nanosheet can efficiently increase electrolyte utilization. At 100 mA cm−2, energy efficiency of the cell using CPA-05-30 is 66.4%, which is 6.0% higher than that of pristine cell. MnO2 nanosheet decorated carbon paper shows excellent electrochemical properties for energy storage application, which evidences its potential application in VRFB. | battery |
The compounds Na3M2(PO4)2F3 [M = Ti, Fe, V] were obtained by two-step solid-state synthesis, and its electrochemical properties as cathode active materials of sodium-ion batteries were investigated. The obtained Na3M2(PO4)2F3 materials were found to have a tetragonal structure with a space group, P4 2 /mnm, and were isostructural with β-Na3V2(PO4)2F3 by X-ray powder diffraction (XRD) measurements. Within this series, Na3V2(PO4)2F3 in particular exhibited stability on cycling and a capacity of approximately 120 mAh g−1 against sodium metal. Capacity retention for this compound was 98%, even after the 40th cycle of prolonged charge/discharge measurements. Ex-situ XRD data for Na3V2(PO4)2F3 electrodes charged and discharged at selected voltages showed that the material structure expanded along the c axis during charging up to 4.3 V and returned to its original dimensions after cycling. This is attributed to the extraction/insertion of Na atoms layers along the (002) a–b plane in the tetragonal structure. | battery |
Publisher Summary Ethical engineering is socially responsible engineering. Green engineering is also a bioethical tenet wherein environmentally conscious attitudes, values, and principles, combined with science, technology, and engineering practice, all directed toward improving local and global environmental quality. Green has become recognized as a code for sustainable programs. The term green engineer is no longer a neophyte to the profession, it is now more likely to mean an environmentally oriented engineer. One of the principles of green engineering is the recognition of the importance of sustainability. The underlying purpose of sustainable development is to help developing nations manage their resources, such as rain forests, without depleting these resources and making them unusable for future generations. In short, the objective is to prevent the collapse of the global ecosystems. Therefore, sustainability is a systematic phenomenon, so it is not surprising that engineers have embraced the concept of sustainable design. At the largest scale, manufacturing, transportation, commerce, and other human activities that promote high consumption and wastefulness of finite resources cannot be sustained. At the individual designer scale, the products and the processes that engineers design must be considered for their entire lifetime and beyond. | non-battery |
We use the comet assay as part of our genotoxicity screening battery for newly synthesized drug candidates. A dataset of more than 250 tests carried out with 75 drug candidates of various chemical classes was analyzed to elucidate the influence of cytotoxicity and compound precipitation on DNA migration in the comet assay. Using a V79 Chinese hamster cell line, 38 of the compounds were negative and 37 were positive in the comet assay. The reproducibility of test results between repeat experiments was 85%. Data on 72 tests with a negative call in which the compounds were tested up to highly cytotoxic concentrations demonstrated that cytotoxicity, as determined by Trypan blue dye exclusion and occurrence of cells with completely fragmented chromatin, did not lead to false positive test results. The majority (64.2%) of compounds with a positive call induced elevated DNA migration in the absence of excessive cytotoxicity. Compound precipitation was observed in 84 tests. In 88.1% of these cases, the test result at the precipitating concentration did not differ from that found at the highest soluble concentration. Half of the remaining 11.9% of contrary results (most of them weak effects) were not reproducible in the respective repeat experiment, indicating no or only a negligible influence of precipitation on test results. The data indicate that using V79 cells, the comet assay specifically detects genotoxic effects and is not confounded by cytotoxicity or compound precipitation under the conditions used. | non-battery |
Highly electrocatalytic activity and strong stability towards both oxygen evolution (OER) and oxygen reduction reaction (ORR) have been regarded as the critical factors in widespread application for the renewable energy technologies. It still remains a huge challenge for developing bifunctional catalysts with low cost, efficiently electrocatalytic activity and strong stability. In this paper, FeCo alloy nanoparticles embedded in nitrogen-doped carbon are synthesized through a simple thermal decomposition of Co-Fe Prussian Blue Analogue (Co-Fe PBA) in Ar atmosphere, during which the organic ligand of CN− in Co-Fe PBA provides both carbon and nitrogen sources for forming nitrogen-doped carbon and FeCo alloy nanoparticles were formed, and thus producing a core-shell structure (FeCo@NC). According to a set of electrochemical tests, the obtained FeCo@NC can function as a Janus to drive OER and ORR with desirable activities and stabilities in alkaline media. Specifically, the FeCo@NC presents an onset-potential of 1.45V, a potential of 1.49V at 10mAcm−2, a Tafel slope of 62mVdec−1 as OER catalyst, and an onset potential of 0.94V, a half-wave potential of 0.8V as ORR catalyst. The performance is comparable to those of precious metal based electrocatalysts, making it possible for potential application in the renewable energy devices, especially Zn-air battery. | battery |
In order to develop high energy density Li rechargeable batteries, nano-sized materials have attracted attention as the active materials. Mesoporous materials consist of the micrometre-sized particles, and they have high surface area due to their mesopore and thin wall thickness of framework. Here, we synthesize a highly ordered mesoporous RuO2 to investigate the effect that the mesoscopic structure has on the capacity and their corresponding reaction mechanism of Li rechargeable battery. The synthesized mesoporous RuO2 shows an initial discharge capacity of 1366 mAh g−1 on mesoporous RuO2, which is higher than that of commercial RuO2. Our findings via In situ X-ray analysis techniques combined with electrochemical analysis demonstrate that the additional capacity of mesoporous RuO2 is resulted from the enhanced interfacial reaction between Ru metal and Li2O formed by conversion reaction of RuO2. Nano-size effects of mesoporous structure such as high surface area, easy electron transport, and small domain would enable to improve the interfacial reaction of highly ordered mesoporous RuO2. The understanding of this relationship between structural engineering and electrochemical properties provides the insight into development of high energy density anode materials in next generation Li rechargeable battery. | battery |
While evidence-based treatments exist for posttraumatic stress disorder (PTSD), a significant sub-set of veterans continue to meet criteria for PTSD after treatment. Sleep problems may affect treatment retention and predict efficacy for PTSD treatments. The present study used data from a clinical trial of Prolonged Exposure therapy (PE) administered to veterans (N=154) to evaluate whether residual sleep symptoms remained after treatment completion, and if so, whether these residual sleep symptoms were associated with higher levels of PTSD and comorbid depression at the end of treatment. Participants (ages 20 to 75 years old; 35.7% Black; 54.5% married) completed demographic questions, symptom assessments, and engagement-related surveys. Hierarchical multiple linear regression models demonstrated that changes in sleep were significant predictors of PTSD and depression symptom reduction above and beyond the influence of demographic and engagement factors (e.g., therapy satisfaction). Greater residual sleep symptoms were predictive of smaller treatment gains. Findings illustrate the potential significance of sleep during the course of PTSD treatment, leading to several important clinical assessment and treatment implications. | non-battery |
Patients with conduction aphasia have been characterized as having a short-term memory deficit that leads to relative difficulty on span and repetition tasks. It has also been observed that these same patients often get the gist of what is said to them, even if they are unable to repeat the information verbatim. To study this phenomenon experimentally, patients with conduction aphasia and left hemisphere-injured controls were tested on a repetition recognition task that required them to listen to a sentence and immediately point to one of three sentences that matched it. On some trials, the distractor sentences contained substituted words that were semantically-related to the target, and on other trials, the distractor sentences contained semantically-distinct words. Patients with conduction aphasia and controls performed well on the latter condition, when distractors were semantically-distinct. However, when the distractor sentences were semantically-related, the patients with conduction aphasia were impaired at identifying the target sentence, suggesting that these patients could not rely on the verbatim trace. To further understand these results, we also tested elderly controls on the same task, except that a delay was introduced between study and test. Like the patients with conduction aphasia, the elderly controls were worse at identifying target sentences when there were semantically-related distractors. Taken together, these results suggest that patients with conduction aphasia rely on non-phonologic cues, such as lexical-semantics, to support their short-term memory, just as normal participants must do in long-term memory tasks when the phonological trace is no longer present. | non-battery |
Many 21st century technological solutions are reliant on the development of new materials with improved properties, and increasingly on materials that can be optimised to perform more than one function. High-throughput and combinatorial methodologies are being used more frequently to discover and design improved materials in a time efficient manner for a variety of applications. A number of technological challenges involve the field of electrochemistry, such as battery development, electrocatalysis, photocatalysis, corrosion protection, sensor development, photovoltaics and light-emitting materials. This review focuses on the utilisation of high-throughput and combinatorial methods that have incorporated, or are associated with, electrochemical methods. In many cases electrochemical determinations are well-suited for high-throughput methodologies, enabling direct quantitative analysis of properties. However, in other circumstances electrochemical measurements are complicated by additional factors. Hence the limitations of high-throughput and combinatorial electrochemistry are also discussed within. | battery |
The Li–S battery is with a much greater theoretical energy density than those of conventional lithium ion batteries. The key to achieve a high performance electrode for Li–S battery lies in the arrangement of the building blocks into a well-designed structure, in which the nanocarbon framework not only acts as an electronic conduit to the encapsulated active materials but also serves as a mini-electrochemical reaction chamber. Therefore, a nanocomposite with sulfur entrapped into hierarchical porous graphene was proposed and fabricated for Li–S batteries. The nanocomposite electrode exhibits high discharging capacitance of 1068 and 543mAhg−1 at a current density of 0.5 and 10C, respectively. The discharging capacity of 386mAhg−1 can be presented at ultra-low temperature of −40°C, which far exceeds the operating range of conventional lithium-ion batteries. The large scale produced hierarchal graphene was mainly decorated with epoxy and hydroxyl groups, which can enhance the binding of S to the C–C bonds due to the induced ripples by the functional groups. These results provided a promising electrode material for energy storage device with high capacitance, which is important for the increasing demands of power sources in cold environments, such as battery systems for electric vehicles in cold zone or for aeronautic applications. | battery |
The electrochemical performance and electrode reaction using Au–Pd nanoparticle (NP) supported mesoporous β-MnO2 as a cathode catalyst for rechargeable Lithium-Air (Li-Air) battery is reported here for the first time. In this study, Au–Pd NP-supported mesoporous β-MnO2 was successfully synthesized by hydrothermal process using a silica KIT-6 template. It has an initial discharge capacity of ca. 775 mAh g−1 with high reversible capacity at a current density of 0.13 mA cm−2. The Au–Pd NP-supported mesoporous β-MnO2 cathode catalyst, which enhances the kinetic of oxygen reduction and evolution reactions (ORR/OERs), thereby improves energy and coulombic efficiency of the Li-Air cell. Raman spectroscopy and ex-situ XRD results of the Au–Pd NP-supported mesoporous β-MnO2 air electrode suggest that the observed capacity comes from oxidation of Li+ to form Li2O2 during discharge to 2.0 V. | battery |
The layered structure LiNi1/3Co1/3Mn1/3O2 cathode material was successfully prepared via a carbonate co-precipitation method, followed by a calcination process at high temperature. The effects of precipitant agent on the crystal structure and morphology of the prepared materials have been studied by XRD, SEM, and the electrochemical performance was investigated by galvanostatic charge–discharge test, cyclic voltammetry and electrochemical impedance spectroscopy. The carbonate precursors (Ni1/3Co1/3Mn1/3)CO3 synthesized by different precipitant agent show a single phase of hexagonal carbonate but a great difference in morphology. The well-crystallized product LiNi1/3Co1/3Mn1/3O2 with homogeneous mixing of transition metal ions were obtained via different precipitants. The material made form Na2CO3 +NH4HCO3 precipitant shows the smallest particles size without agglomeration, the lowest polarization and the lowest interfacial resistance, which leads to excellent comprehensive electrochemical performance. | battery |
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