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The goal of this work is to study electrical transport within multiphase structures of Li-ion electrodes through numerical microstructure reconstruction and direct evaluation. Li-ion battery electrodes at different compositions were numerically reconstructed mimicking the experimental fabrication process. Electrode material agglomeration and interfaces between components, as well as possible implication on battery performance were explored. Distribution of electrode phases (active material particles, binder, conducting phase carbon), and electrical conductivity were studied upon the reconstructed 3D microstructure. The electrical conductivity of the electrodes was estimated from the reconstructed electrode structures, and compared favorably with those measured experimentally using four-probe tests. It has been found that macro mass transport properties of the numerically reconstructed electrodes depend critically on nanoscale physical characteristics of electrode components and their contact. This work revealed the localized nanoscale electrode complexity and transport processes in great details, which are currently difficult to investigate experimentally or by alternative models. | battery |
The human brain organoids derived from pluripotent cells are a new class of three-dimensional tissue systems that recapitulates several neural epithelial aspects. Brain organoids have already helped efficient modeling of crucial elements of brain development and disorders. Brain organoids’ suitability in modeling glioma has started to emerge, offering another usefulness of brain organoids in disease modeling. Although the current state-of-the organoids mostly reflect the immature state of the brain, with their vast cell diversity, human brain-like cytoarchitecture, feasibility in culturing, handling, imaging, and tractability can offer enormous potential in reflecting the glioma invasion, integration, and interaction with different neuronal cell types. Here, we summarize the current trend of employing brain organoids in glioma modeling and discuss the immediate challenges. Solving them might lay a foundation for using brain organoids as a pre-clinical 3D substrate to dissect the glioma invasion mechanisms in detail. | non-battery |
Complexity in strongly correlated oxides such as perovskite strictly dominates their performance for oxygen reduction reaction (ORR). Precise control of the physical correlations among spin, charge, orbital, and lattice degrees of freedom in these oxides can exercise considerable enhancement of ORR activity, but has until now remained elusive. Here, we show that nonmagnetic hexavalent molybdenum (Mo6+) atomically dispersed within oxide lattice steers the intrinsic activity of catalytically active sites by entrapping extrinsic electrons at their 3d orbitals, without the occurrence of lattice symmetry breaking and magnetic perturbation. With double perovskite La2Co2+Mn4+O6 as a model catalyst, the atomic-scale electron trap generates additional high-spin, catalytically active Mn3+(t32ge1g) sites and highly conductive Co2+(e2g)–O–Mn3+(e1g) double exchange channels, leading to five-fold improvement in ORR activity. First-principles calculations reveal a substantial increase of the spin density on Mn sites caused by electron trapping, and unambiguously confirm a more exothermic reaction pathway as well as a lower barrier of the rate-limiting surface hydroxide regeneration on Mo1/La2CoMnO6. We can also extend this strategy with atomic precision easily to other four oxide catalysts and achieve large enhancement in their ORR activities as anticipated, indicating its broad utility. This work embodies the theories of condensed matter physics in rational design of ORR catalysts, and may inspire further development of the control of electron correlation in strongly correlated electron systems.
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In May 2005, an international, interdisciplinary group of researchers gathered in Bethesda, MD, USA, for a workshop to discuss the development of treatments for patients with nonepileptic seizures (NES). Specific subgroup topics that were covered included: pediatric NES; presenting the diagnosis of NES, outcome measures for NES trials; classification of NES subtypes; and pharmacological treatment approaches and psychotherapies. The intent was to develop specific research strategies that can be expanded to involve a large segment of the epilepsy and psychiatric treatment communities. Various projects have resulted from the workshop, including the initial development of a prospective randomized clinical trial for NES. | non-battery |
In this study, gas diffusion electrodes (GDEs) with two catalyst layers were fabricated and tested for their electrode performance for oxygen reduction in an alkaline solution. The LaMnO3/carbon black catalyst layers were fabricated using a reverse micelle method to finely disperse the LaMnO3 particles onto the carbon matrices, for which commercial Ketjen Black (KB) (1270 m2 g−1) and Vulcan XC-72R (VX) (254 m2 g−1) were used. The three-layer-structured GDE with the two LaMnO3/KB and LaMnO3/VX catalyst layers exhibited a superior oxygen reduction activity when compared to that of a conventional GDE with only one LaMnO3/KB catalyst layer. Pore size distribution and gas permeability measurements revealed that the LaMnO3/VX layer was more porous and had higher gas permeability than the LaMnO3/KB layer. These results suggest that the intermediate layer of LaMnO3/VX can efficiently supply oxygen to reaction sites dispersed in the LaMnO3/KB and LaMnO3/VX catalyst layers, which consequently leads to an improvement in the electrode performance. | battery |
Cobalt sulfide (Co1−xS) is studied extensively as an anode material for lithium-ion batteries (LIBs) due to high theoretical capacity, however, low electronic conductivity and large volume change during the discharge/charge process limit its actual application. In this study, we synthesize Co1−xS-reduced graphene oxide (Co1−xS-rGO) composite through a simple solvothermal reaction and then freeze-drying process. The introduction of rGO not only improves electronic conductivity and redox kinetics of electrode material but also prevents Co1−xS nanoparticles from aggregation. At a current density of 200mAg−1, the discharge capacity of Co1−xS-rGO maintains 643mAhg−1 after 100cycles. Even at high current density of 1000mAg−1, the discharge capacity of 625mAhg−1 is retained after 200cycles, which is close to theoretical capacity (683mAhg−1). And then, Co1−xS-rGO delivers good rate performance and cycling stability. In the meanwhile, in-situ synthesis method is facile. These results indicate that Co1−xS-rGO could be a promising anode material for LIBs. | battery |
An efficient synthesis method to grow well attached NiO nanobelts from 3D graphene sheets (3DGS) is reported herein. Ni-ion exchanged resin provides the initial Ni reactant portion, which serves both as a catalyst to form 3DGS and then as a seeding agent to grow the NiO nanobelts. The macroporous structure of 3DGS provides NiO containment to achieve a high cycling stability of up to 445 mAh g−1 after 360 cycles (and >112% capacity retention after 515 cycles) at a high current density of 2 A g−1. With a 26.8 wt.% content of NiO on 3DGS, increases in specific and volumetric capacity were 41.6 and 75.7% respectively over that of 3DGS at matching current densities. Therefore, the seeded growth of NiO nanobelts from 3DGS significantly boosts volumetric capacity, while 3DGS enables high rate long term cycling of the NiO. The high rate cycling stability of NiO on 3DGS can be attributed to (i) good attachment and contact to the large surface of 3DGS, (ii) high electron conductivity and rapid Li-ion transfer (via the interconnected, highly conductive graphitized walls of 3DGS) and (iii) buffering void space in 3DGS to contain volume expansion of NiO during charge/discharge. | battery |
The aim of this study was to identify the neuropsychological features in patients with temporal lobe epilepsy (TLE) and their correlation with seizure-related variables. For this purpose, we carried out a retrospective analysis of data from 65 patients with TLE who had undergone a comprehensive neuropsychological assessment. The results suggest that the majority of patients with TLE were impaired in more than one cognitive domain, and among these patients, the mean proportions with defective semantic memory, language, motor/psychomotor speed, verbal episodic memory, and executive function were >50% each. Moreover, age at seizure onset was the strongest predictor of general intellectual impairment, and number of antiepileptic drugs and seizure frequency could significantly predict deficits in verbal memory, language, and psychomotor speed. However, epilepsy duration was a less potent predictor of cognitive deficit than has been reported in cross-sectional studies. | non-battery |
Productive knowledge work and high-level literacy are essential for engagement in a Knowledge society. In the research reported in this article, students were engaged in sustained collaborative knowledge building in science and social studies. The vocabulary growth of 22 students over Grades 3 and 4 was traced, based on their entries to Knowledge Forum—a knowledge building environment used as an integral part of classroom work. It is the communal space where knowledge work–ideas, reference material, results of experiments, and so forth–is entered and continually improved. Analysis of lexical frequency profiles indicated significant growth in productive written vocabulary, including academic words. In a Grade 4 inquiry, students incorporated almost all the domain-specific terms at and below their current grade level, and most of those expected for upper grade levels (5–8) based on the curriculum guidelines. Domain-specific and academic words were correlated with depth of understanding. High correlations between student engagement in knowledge building and vocabulary growth suggest that productive vocabulary can be developed through sustained knowledge building in subject areas.
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We describe the case of a 10-year-old girl who developed behavioral changes consistent with Klüver–Bucy Syndrome following Listeria meningoencephalitis at 2½years of age. MRI at age 4 revealed evidence of diffuse brain atrophy with predominant temporal lobe involvement. Electroencephalograpy at 9½years of age showed abnormal electrical discharges from the left temporal area. Follow-up MRI with volumetric analysis of the mesial temporal structures at 9years of age demonstrated decreased hippocampal volume bilaterally. Consistent with the morphological abnormalities, serial neuropsychological evaluations demonstrated expressive and receptive language impairment and an amnestic syndrome that significantly decreased her ability to make new declarative memories and maintain adequate academic progress. | non-battery |
In this paper, graphene and MnO2 nanoparticle were programmed to synthesize a nanocomposite, which was used to modified glassy carbon electrode (GCE). The presence of Gr-MnO2 nanocomposite has enhanced the electrochemical performance of the GCE towards the mercuric chloride (HgCl2). Electrochemical behaviors of HgCl2 on different electrodes were evaluated by cyclic voltammetry, the result shows that the Gr-MnO2 nanocomposite modified electrode showed higher chemical activity with HgCl2 than bare GCE, MnO2/GCE and Gr/GCE. In PBS solution (pH=5.5), the oxidation peak current raised as the concentration of HgCl2 increased from 12.1 to 210.8μM, the detection limit was 2.0μM (S/N=3). The modified electrode showed good selectivity, high stability and excellent regeneration. | battery |
Accurate estimation for the state of charge (SOC) is one of the most important aspects of a battery management system (BMS) in electric vehicles (EVs) as it provides drivers with the EVs' remaining range. However, it is difficult to get an accurate SOC, because its value cannot be directly measured and is affected by various factors, such as the operating temperature, current rate and cycle number. In this paper, a modified equivalent circuit model is presented to include the impact of different current rates and SOCs on the battery internal resistance, and the impact of different temperatures and current rates on the battery capacity. Besides, a linear–averaging method is presented to calculate the internal resistance and practical capacity correction factors according to data collected from the experimental bench and saved as look-up tables. The unscented Kalman filter (UKF) algorithm is then introduced to estimate the SOC according to the presented model. Experiments based on actual urban driving cycles are carried out to evaluate the performance of the presented method by comparing with two existed methods. Experimental results show that the proposed method can reduce the computation cost and improve the SOC estimation accuracy simultaneously. | battery |
Energy harvesting from ambient radio frequency waves has the potential for realizing long lived wireless sensor networks, by reducing their dependence on the limited and irreplaceable on-board batteries. We propose two cross-layer approaches, called device-agnostic (DA) and device-specific (DS) protocols, for such networks composed of energy harvesting boards connected to off-the-shelf available sensors. These protocols determine the routing paths and the harvesting-transmission duty cycle at each hop under different conditions. The DA scheme relies purely on the local measurements on the harvesting capability of a node after the sensors are deployed, and is useful for single-flow networks. The DS scheme provides a joint hardware–software optimization by allowing the selection of the energy storing capacitor, apart from the route and duty cycle determination. Both schemes rely on a rich set of device-level experimental studies that help provide exact performance characteristics in practical scenarios, and results reveal significant performance improvement over other existing schemes. | non-battery |
Background: Semantic memory abnormalities are argued to be a cardinal feature of schizophrenia, with research suggesting that symptoms arise from a disturbance in the organisation of knowledge. One problem with this literature has been inconsistent finding using a semantic memory assessment technique called semantic priming (SP). These inconsistencies have been attributed to a number of confounding factors that limit research with symptomatic clinical patients, including illness duration and medication use. Recently analogue studies, using persons with high schizotypy, have aimed to overcome these confounding factors. This presentation presents data from three analogue studies investigating semantic memory in high schizotypy. Methods: Study 1 examined SP in 26 high and 32 low scorers on the OLIFE schizotypy scale. Study 2 correlated SP with OLIFE scores in 53 students. Study 3 compared 24 high and 30 low OLIFE scorers on a large battery of semantic memory measures. Results: Study 1 and 3 established that semantic memory abnormalities are present in high schizotypes in SP and one other implicit semantic memory measure (semantic categorisation). Study 2 showed that the correlational analyses associated priming deficits with cognitive disorganisation scores. This is the analogue scale for thought disorder. Discussion: Unlike patients with schizophrenia high schizotypes do not have globally impaired semantic memory. High schizotypes show subtle abnormalities on implicit semantic memory measures and not on explicit measures. Significantly these abnormalities were related to cognitive disorganisation and possible thought disorder. Semantic memory deficits in high schizotypes may be akin to those in the prodromal phase of schizophrenia. | non-battery |
Heteroatoms (B, N, O)-containing porous manganese oxide (MnO2)/carbon nanofiber (MnB-CNF) materials are prepared by one-step electrospinning method via polyacrylonitrile (PAN) and manganese(II) chloride (MnCl2) in dimethylformamide (DMF) solution containing different concentrations of B2O3. The MnB-CNF electrode exhibits optimized electrochemical behavior with a high energy density of 22.6Whkg−1 at a power density of 400Wkg−1 and a specific capacitance range of 210–160Fg−1 in the discharge current density range of 1.0 to 20mAcm−2 in aqueous KOH electrolyte. The higher electrochemical performance of MnB-CNF as a result of the electrochemical double-layer capacitor (EDLC), compared to regular Mn-CNF without B-based functional groups, is attributed to well-balanced meso- and micropores affecting the easy adsorption and transport of electrolyte ions, in addition to the pseudocapacitive redox reactions from MnO2, N, O, and extra numerous B in alkaline electrolytes. Thus, tailoring the pore structures with proper specific surface area, pore size, and number of heteroatoms is crucial for optimizing their electrochemical properties in the combined efforts to develop EDLCs and pseudocapacitance. | battery |
Composite polypyrrole–polysaccharide (PPyPSacc) films, such as polypyrrole–heparin (PPyHep), polypyrrole–chondroitin sulfate A (PPyCS-A) and polypyrrole–hyaluronic acid (PPyHA) have been successfully obtained by optimized electrochemical syntheses. The PPyPSacc samples show dopant-mediated tunable physical properties and good stability in air and in biological fluids. The immobilization of PSacc within the polymer matrix renders the surface samples suitable for cell/substrate communication studies. In order to check the viability of PPyPSacc thin films as electrodes for cell electrostimulation, we studied their interface evolution upon aging in a simulated physiological solution (pH=7.4, 37°C) by using electrochemical impedance spectroscopy, cyclic voltammetry and scanning electron microscopy. At open circuit conditions, the overall impedance of the electrodes increases upon aging as a consequence of a fast accumulation of ions at the interface, also related to the increase of porosity and wettability. As the interface impedance increases, the ionic and electronic transport into the polymer is hindered. Nevertheless, no mechanical degradation of the PPyPSacc samples is observed on aging. After 10 days of aging the PPyHep samples keep about 60% of their initial redox capacity. As a consequence the studied materials are capable to supply electrical stimulations to cells in a biological environment well beyond the conventional time-range. | battery |
This paper proposes an adaptive mode switch strategy (AMSS) based on simulated annealing (SA) optimization of a multi-mode hybrid energy storage system (HESS) for electric vehicles. The proposed SA-AMSS is derived from a rule-based strategy to achieve the adaptive mode selection and energy management optimization. To improve the overall system efficiency of the multi-mode HESS, the state of charge (SOC) level of the supercapacitor (SC), the power level and the component efficiencies are discussed. On this basis, the objective function for the AMSS is established, focusing on selecting the most suitable mode. Furthermore, to accomplish a global energy management optimization based on the driving cycles, the SA approach is introduced into the optimizations of the reference SC SOC and battery power, rather than the direct power distribution optimization between the battery and SC. The AMSS is implemented based on the SA optimization. Simulations and experiments are presented to verify the effectiveness of the SA-AMSS for the multi-mode HESS. Results show that the SA-AMSS can not only reduce the frequency of the mode switching, but also avoid the sudden excessive power output of the battery. The SC can respond to all peak power demands and absorb all the braking energy. So the SA-AMSS is very flexible and effective, and the battery safety can be guaranteed. Compared with the rule-based strategy, the overall system efficiency of the multi-mode HESS is significantly improved. | battery |
The mixed cation system, Li10(Ge1−x M x )P2S12 (M = Si, Sn), was synthesized and the ionic conductivities of the resulting solid solutions were determined. The Si–Ge and Ge–Sn systems provided single phase solid solutions for the composition 0 ≤ x < 1.0 and 0 ≤ x ≤ 1.0 in Li10(Ge1−x Si x )P2S12 and Li10(Ge1−x Sn x )P2S12, respectively. The lattice size gradually increased from Si to Sn through the Ge systems, reflecting the ionic size of these elements. On the other hand, conductivity did not follow the increase in lattice volume. Conductivity increased in the Si to Ge system, with the maximum conductivity value of 8.6 × 10−3 S cm−1 provided by the compressed powder with the composition Li10Ge0.95Si0.05P2S12, which is close to the original Li10GeP2S12 (LGPS) composition. The conductivity decreased with increasing Sn content, indicating that lattice volume is not the only parameter that affects ionic conduction in this structure. The relationship between conductivity and lattice volume is discussed. | battery |
Electrochemical materials are under rigorous search for building advanced energy storage devices. Herein, supercapacitive properties of highly crystalline and ultrathin cobalt oxide (Co3O4) nanowires (diameter ∼30–60 nm) synthesized using an aqueous polymeric solution based electrospinning process are reported. These nanowire electrodes show a specific capacitance (C S) of ∼1110 F g−1 in 6 M KOH at a current density of 1 A g−1 with coulombic efficiency ∼100%. Asymmetric supercapacitors (ASCs) (C S ∼175 F g−1 at 2 A g−1 galvanostatic cycling) are fabricated using the Co3O4 as anode and commercial activated carbon (AC) as cathode and compared their performance with symmetric electrochemical double layer capacitors (EDLCs) fabricated using AC (C S ∼31 F g−1 at 2 A g−1 galvanostatic cycling). The Co3O4//AC ASCs deliver specific energy densities (E S) of 47.6, 35.4, 20 and 8 Wh kg−1 at specific power densities (P S) 1392, 3500, 7000 and 7400 W kg−1, respectively. The performance of ASCs is much superior to the control EDLCs, which deliver E S of 9.2, 8.9, 8.4 and 6.8 Wh kg−1 at P S 358, 695, 1400 and 3500 W kg−1, respectively. The ASCs show nearly six times higher energy density (∼47.6 Wh kg−1) than EDLC (8.4 Wh kg−1) without compromising its power density (∼1400 W kg−1) at similar galvanostatic cycling conditions (2 A g−1). | battery |
The reductive electrochemical activation of three C2 freons, and one C1 freon, in four different room temperature ionic liquids (RTILs), is reported. Electrochemistry was performed using glassy carbon (GC), platinum and silver cathodes. The apparent reduction potentials for the freons ranged from −1.0V vs. Pt to −2.8V vs. Pt, depending on the freon structure, cathode material and RTIL medium. Discharge potentials were found to be distinctly more cathodic in RTIL media, relative to organic solvents (dimethylformamide), due to the significant ohmic loss within the cell as a consequence of the viscous nature of the RTIL media. Similarly, cathodic currents were greatly suppressed in RTILs due to low mass transport rates. The electrocatalytic nature of Ag cathodes is maintained in RTIL media with some systems exhibiting over 1V reduction in discharge potentials. | battery |
Phase change materials (PCM) are widely used for energy storage applications worldwide. The objective of the study is to review the current state of research on PCM materials, energy storage, environmental aspects and identifying potential research areas which needs focus to make this technology widely marketable and economically promising. The paper presents PCM research status, material properties, microencapsulation, shape stabilization techniques, commercial applications and environmental issues and also covers areas which have not been given much attention in previous studies like toxicity, health hazards, fire retardation techniques and current market scenario. The study shows that salt hydrates are safe if carefully handled and commercial grade paraffins being flammable, release toxic vapors thus are potential health hazard so need to be used carefully. Further research on fire retardation of PCM is found lacking in literature. Critical issues to ensure long term performance, are discussed which will help researchers to identify appropriate PCM for different commercial applications. New innovative PCM materials are identified although these are not used in real applications as yet. The commercial potential of PCM products is presented which shows that these materials have promising solutions for textiles, heat or cold storage during transits, pain relief packs, vaccine and blood storage where maintenance of a critical temperature is important. These materials could significantly cut down the air conditioning demands in future provided the current challenges are met. With increased awareness and stricter environmental regulations in future, PCM market potential is expected to rise. | battery |
Psychometric intelligence is closely related to working memory capacity. Here we aim to determine the associations of neural activation patterns during the N-back working memory paradigm with psychometric intelligence and working memory performance. We solved the statistical problems of previous studies using (1) a large cohort of 1235 young adults and (2) robust voxel-by-voxel permutation-based statistics at the whole-brain level. Many of the significant correlations were weak, and our findings were not consistent with those of previous studies. We observed that many of the significant correlations involved brain areas in the periphery or boundaries between the task-positive network (TPN) and task-negative network (TNN), suggesting that the expansion of the TPN or TNN is associated with greater cognitive ability. Lower activity in TPN and less task-induced deactivation (TID) in TNN were associated with greater cognitive ability. These findings indicate that subjects with greater cognitive ability have a lower brain response to task demand, consistent with the notion that TID in TNN reflects cognitive demand but partly inconsistent with the prevailing neural efficiency theory. One exception was the pre-supplementary motor area, which plays a key role in cognitive control and sequential processing. In this area, intelligent subjects demonstrated greater activity related to working memory, suggesting that the pre-supplementary motor area plays a unique role in the execution of working memory tasks in intelligent subjects.
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Microbes are microscopic living organisms that surround us which include bacteria, archaea, most protozoa, and some fungi and algae. In recent years, microbes have been explored as novel precursors to synthesize carbon-based (nano)materials and as substrates or templates to produce carbon-containing (nano)composites. Being greener and more affordable, microbe-derived carbons (MDCs) offer good potential for energy applications. In this review, we describe the unique advantages of MDCs and outline the common procedures to prepare them. We also extensively discuss the energy applications of MDCs including their use as electrodes in supercapacitors and lithium-ion batteries, and as electrocatalysts for processes such as oxygen reduction, oxygen evolution, and hydrogen evolution reactions which are essential for fuel cell and water electrochemical splitting cells. Based on the literature trend and our group's expertise, we propose potential research directions for developing new types of MDCs. This review, therefore, provides the state-of-the-art of a new energy chemistry concept. We expect to stimulate future research on the applications of MDCs that may address energy and environmental challenges that our societies are facing. | battery |
We describe a four-probe electrical technique that enables real-time temperature monitoring of the carbon anode in a 53Ah lithium-ion rechargeable cell during charging and discharging. This technique uses only electrical contacts to the positive and negative terminals of the cell, eliminating the need to insert temperature sensors inside the cell. Our method is based on the intrinsic relationship of anode temperature with phase shift between an applied sinusoidal current and the resulting voltage, valid within the 5% and 95% range of the state-of-charge (SoC) of the cell. Using this technique, we demonstrate that the anode temperature (T anode ) can deviate from the temperature measured at the outside surface (T surf ) of the cell during charge and discharge. Additionally, we show that anode temperature is primarily determined by entropy change at the anode or by resistive impedance of the anode, depending on the environment temperature (T env ). | battery |
A rural forested site was selected to measure Al, Cd, Cr, Mn, Ni, Pb and V (soluble and insoluble fractions), and the major inorganic ions Na+, K+, Ca+, Mg2+, NH4 +, H+, Cl−, NO3 − and SO4 2−. A total of 44 samples were collected during the rain seasons of 2001–02. Trace metals were analyzed by atomic absorption spectroscopy with a graphite furnace accessory. As for ion analysis a Perkin Elmer liquid chromatograph was used. The volume-weighted mean concentration (VWMC) results indicated that highest concentration was that of aluminum followed in decreasing order by Mn, V, Pb, Cr and Cd. Solubilities were calculated in rain samples at pH<5 and pH>5, solubilities at pH<5 were higher than the solubilities at pH>5, as it has been reported by other authors. The rains from Rancho Viejo had a pH of 4.5 indicating an acid nature. Comparing the VWMC of Ca2+ (7.79μeql−1) with NH4 + (46.36μeql−1), indicated that the NH4 + was the main neutralizing compound. The scatter plots showed that the acidity of rain was due mainly to H2SO4 plus HNO3 (55% and 22.7%, respectively). Backward trajectories using the NOAA HYSPLIT Model were calculated at 3000m above mean sea level (AMSL) and indicated significant differences in the mean concentrations that depended on the wind direction. Good and positive correlations were found among all trace metals that indicate a common origin. Factor Statistical Analysis 6.4 was applied to all data to have a better knowledge of the origin of the trace metals in rainwater. To evaluate the contribution of non-crustal sources an enrichment factor was also applied. | non-battery |
Hybrid organic/inorganic films, composed of polyaniline (PANI) matrix and Prussian blue-like nickel hexacyanoferrate redox centers, showed reversible electrochromic behavior in acidic potassium salt electrolytes. The system's coloration properties were assessed from various spectroelectrochemical measurements including voltabsorptometry that involved monitoring of the time-derivative signal of absorbance at 700 and 410 nm as a function of linearly scanned potential. Gold-covered foil was used as a conductive, optically transparent, substrate onto which the composite film was electrodeposited by potential cycling in the mixture for modification consisting of aniline monomer, Ni2+, Fe(CN)6 3− and electrolyte containing K+ and H+ ions. An important feature of hybrid (composite) material was that its electrochromic properties were dominated by color changes occurring in the PANI component. Coloration originating from nickel hexacyanoferrate barely affected the system's electrochromic characteristics. But the cyanometallate redox centers distributed in the PANI matrix behaved reversibly as expected for a system capable of fast charge transport. | battery |
We studied an inorganic composite membrane as the separator for Li-ion batteries. Being made of mainly CaCO3 powder and a small amount of polymer binder, the composite membrane has excellent wettability with liquid electrolytes due to its high porosity and good capillarity. Ionic conductivity of the membrane can be easily achieved by absorbing a liquid electrolyte. Additional benefit of such a membrane is that the alkali CaCO3 can scavenge acidic HF, which is inevitably present in the LiPF6-based electrolytes used currently in the Li-ion batteries. In this work, we typically evaluated a membrane with the composition of 92:8 (wt.) CaCO3/Telfon by using a 1.0m LiPF6 dissolved in a 3:7 (wt.) mixture of ethylene carbonate (EC) and ethylmethyl carbonate (EMC) as the liquid electrolyte. Ionic conductivity of the electrolyte-wetted membrane was measured to be 2.4mScm−1 at 20°C versus 8.0mScm−1 of the liquid electrolyte. With the said membrane as a separator, both Li/graphite and Li/cathode half-cells exhibited good capacity retention. We also found that the Li-ion cell fabricated in this manner not only had stable capacity retention, but also showed good high-rate performance. | battery |
Lithium iron phosphate (LiFePO4) thin film electrodes were prepared by pulsed laser deposition (PLD). The thin films were annealed at various temperatures under argon gas flow and the influence of annealing temperature on their electrochemical performance was studied. The thin films annealed at 773 and 873K exhibited a couple of redox peaks at 3.4V (versus Li/Li+) that are characteristics of the electrochemical lithium insertion/extraction of LiFePO4. Atomic force microscopy (AFM) observation revealed that the film annealed at 773K (773K-film) consisted of small grains with 50nm in thickness, and the grain size increased with an increase of annealing temperature. Because of its small-sized grains, the 773K-film showed high rate capability and the discharge capacity at 10μA maintained 65% of that at 25nA. However, the discharge capacity of the 773K-film was ca. 10% smaller than that of the film annealed at 873K, indicating that annealing at 773K is slightly insufficient to obtain well-crystallized LiFePO4. From these results, it was concluded that a point of optimization between high rate capability and capacity would be found between 773 and 873K. | battery |
Very little is known about factors that underlie the behavioral health status of LBGT compared with heterosexual soldiers. To address this knowledge gap, the current study explored the potential mechanistic roles of perceived prejudice and support for the LGBT community as they related to observed differences in behavioral health symptoms between LGBT and heterosexual soldiers. | non-battery |
LiNi0.6Co0.4−x Mn x O2 (0.15≦ x ≦0.25) cathode materials for lithium-ion batteries are synthesized by calcining a mixture of Ni0.6Co0.4−x Mn x (OH)2 and Li2CO3 at 890–950°C for 15h in a flowing oxygen atmosphere. The Ni0.6Co0.4−x Mn x (OH)2 precursor is obtained by a chemical co-precipitation method at pH=11. Thermal analysis of the precursor for LiNi0.6Co0.4−x Mn x O2 (0.15≦ x ≦0.25) shows that the weight loss is about 30% until the temperature reaches 750°C. The X-ray diffraction patterns indicate the pure, layered, hexagonal structure of LiNi0.6Co0.4−x Mn x O2. Scanning electron micrographs reveal that the morphology of the samples is characterized by larger agglomerates (5–15μm) of rather small layered particles (around 100nm). The particle size tends to decrease with increasing Mn content. The electrochemical behaviour of LiNi0.6Co0.4−x Mn x O2 powder is examined by using test cells cycled within the voltage range 3–4.3V at the 0.1C rate for the first cycle and then at the 0.2C rate. LiNi0.6Co0.4−x Mn x O2 (0.15≦ x ≦0.25) cathode materials exhibit good initial discharge capacity (165–180mAhg−1) and a capacity retention of above 95% after 20 cycles. It is demonstrated that LiNi x Co y Mn1−x−y O2 electrodes are promising candidates for application as cathodes in lithium-ion batteries. | battery |
This study investigated patterns of motor brain activation, white matter (WM) integrity of inter- and intrahemispheric connectivity and their associations with hand function in children with unilateral cerebral palsy (CP-U). Fourteen CP-U (mean age 10.6 ± 2.7 years) and 14 typically developing children (TDC) underwent magnetic resonance imaging. CP-U underwent extensive motor evaluation. Pattern of brain activation during a motor task was studied in 12 CP-U and six TDC, by calculating laterality index (LI) and percent activation in the sensorimotor areas (around the central sulcus), and quantifying the activation in the supplementary motor area (SMA). Diffusivity parameters were measured in CP-U and eight other TDC for the corpus callosum (CC), affected and less affected cortico-spinal tracts (CST), and posterior limb of the internal capsule (PLIC). Abnormal patterns of brain activation were detected in areas around the central sulcus in 9/12 CP-U, with bilateral activation and/or reduced percent activation. More activation in areas around the central sulcus of the affected hemisphere was associated with better hand function. CP-U demonstrated more activation in the SMA when moving the affected hand compared to the less affected hand. CP-U displayed reduced WM integrity compared to TDC, in the midbody and splenium of the CC, affected CST and affected PLIC. WM integrity in these tracts was correlated with hand function. While abnormal pattern of brain activation was detected mainly when moving the affected hand, the integrity of the CC was correlated with function of both hands and bimanual skills. This study highlights the importance of interhemispheric connectivity for hand function in CP-U, which may have clinical implications regarding prognosis and management.
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Ordered mesoporous materials, due to its potential applications in catalysis, separation technologies, and nano-science have attracted much attention in the past few years. In this work, a novel PEO-based composite polymer electrolyte by using organic–inorganic hybrid EO20PO70EO20 @ mesoporous silica (P123 @ SBA-15) as the filler has been developed. The interactions between P123 @ SBA-15 hybrid and PEO chains are studied by X-ray diffraction (XRD), differential scanning calorimeter (DSC), and FT-IR techniques. The effects of P123 @ SBA-15 on the electrochemical properties of the PEO-based electrolyte, such as ionic conductivity, lithium ion transference number are studied by electrochemical ac impedance spectroscopy and steady-state current method. The experiment results show that P123 @ SBA-15 can enhance the ionic conductivity and increase the lithium ion transference number of PEO-based electrolyte, which are induced by the special topology structure of P123 in P123 @ SBA-15 hybrid, at the same time. The excellent lithium transport properties and broad electrochemical stability window suggesting that PEO–LiClO4/P123 @ SBA-15 composite polymer electrolyte can be used as candidate electrolyte materials for lithium polymer batteries. | battery |
Energy storage and conversion is a very important link between the steps of energy production and energy consumption. Traditional fossil fuels are natural and unsustainable energy storage medium with limited reserves and notorious pollution problems, therefore demanding for a better choice to store and utilize the green and renewable energies in the future. Unitized regenerative fuel cell (URFC), a compact version of regenerative fuel cell with only one electrochemical cell, is one of the competent technologies for this purpose. A URFC can produce hydrogen fuel through an electrolysis mode to store the excess energy, and output power in a fuel cell mode to meet different consumption requirements. Such a reversible system possesses several distinctive advantages such as high specific energy, pollution-free, and most importantly, the decoupled energy storage capacity with rated power. Based on the different electrolytes utilized, current available URFC technologies include the most common proton exchange membrane (PEM)-based URFC, and other types of URFC such as the alkaline, solid oxide and microfluidic URFCs. This part of the URFC review emphasizes on the PEM-based URFC. Specifically, the research progress on both cell components and systematic issues is introduced. Benefiting from its fairly mature technology stage, the PEM-based URFC has already been applied in aerospace and terrestrial areas. However, for large-scale application, their cost and efficiency are still the obstacles when competing with other energy storage technologies. As for the alkaline, solid oxide and microfluidic types of URFC, their research progress is reported independently in part B of this review. | battery |
This study examines the effects of mental health parity laws on mental health care utilization and mental health outcomes of children and adolescents from middle-income households in the context of the 2008 Mental Health Parity and Addiction Equity Act (MHPAEA), using data from the 2007 and 2011–2012 waves of the National Survey of Children’s Health (N = 57,549). A difference-in-differences method controlling for demographic characteristics, state Medicaid eligibility, and unemployment is used. The analyses show that after the enactment of the MHPAEA, children and adolescents with family income between 150 and 400% of the federal poverty level in states without prior parity laws experience a 2.80 percentage point relative increase (p < 0.01) in mental health care utilization. These children and adolescents also experience an increase in the diagnoses of anxiety, which may suggest that better access to healthcare increases screening for previously under-diagnosed disorders. | non-battery |
The process of neurogenesis in which new neurons are generated by proliferation and differentiation of neural stem/progenitor cells (NSCs/NPCs) has been a topic of intensive recent investigation. Investigations of the factors which regulate this process have recently begun to include immune factors including immune cells and cytokines, however the class of immune proteins designated as chemokines have been relatively neglected. Increasing evidence for novel brain-specific mechanisms of chemokines beyond their classical chemotactic functions has suggested that they may play a role in the regulation of NSC/NPC biology. | non-battery |
The sources and formation of atmospheric particulate mercury, Hg(p), in the Tokyo metropolitan area were investigated. Nine municipal solid waste (MSW) incinerators are located within 10km of the study site. Airborne particles >10μm in diameter were collected on a quartz fiber filter, and Hg(p) was measured by AAS following thermal desorption and gold trap amalgamation. Total gaseous mercury (TGM) was also determined using a continuous analyzer employing gold trap amalgamation and AAS. An average Hg(p) level of 0.098±0.051ngm−3 (3.5±1.4% for total Hg=Hg(p)+TGM) was observed during the period from April 2000–March 2001, and Hg(p) levels tended to decrease during the summer. We investigated the relationship between concentrations of Hg(p) and Pb, a marker element for particles from MSW incineration. The propriety of using Pb as the marker element was verified based on the lead isotope ratios and the relationship between Pb, Cd and Zn concentrations. The results showed that Hg(p) concentration was correlated positively with Pb concentration and negatively with air temperature. On the other hand, the results of chemical leaching treatment for airborne particles indicated that most of the Hg in the particles might exist in the elemental form, Hg0. This suggests that some of the Hg0 emitted from MSW incinerators was adsorbed onto MSW incinerator particles in the atmosphere due to an abrupt decrease in temperature after emission, depending on air temperature. Thus, it is likely that the Hg(p) level in the Tokyo metropolitan area is closely related to the gaseous Hg0 emissions from MSW incinerators. In addition, from the thermodynamic analysis, it is inferred that the formation of Hg(p) is governed by the physical adsorption equilibrium of Hg0 between gas and particle phases. | non-battery |
Spherical Ni-rich LiNi0.8CoxMn0.2-xO2 (x=0, 0.05, 0.1, 0.15) positive-electrode materials were synthesized by calcining the mixtures of LiOH·H2O and Ni0.8CoxMn0.2-x(OH)2 precursor formed from a simple continuous co-precipitation method. The influences of Co content on the microstructures and electrochemical properties of LiNi0.8CoxMn0.2-xO2 positive-electrode materials were investigated through X-Ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscope, transmission electron microscope and electrochemical tests. The results showed that the intensity ratio of I(003)/I(104) for positive-electrode material became higher with increasing Co content, implying the layered structure became better. The electrochemical tests confirmed LiNi0.8Co0.15Mn0.05O2 (x=0.15) exhibited the best discharge capacity of 180.8mAhg−1 after 100 cycles between 2.75 and 4.3V at 0.2C, with an excellent capacity retention of 97.31% and an high capacity of 165.2mAhg−1 at 5C. Importantly no obvious structure and morphology change was observed for LiNi0.8Mn0.05Co0.15O2 before and after cycling processes. The improved cycling stability and rate capability maybe resulted from low Li/Ni cation mixing, high electric conductivity and good structure stability. | battery |
An environmental, economic, and highly effective method based on microwave treatment was firstly used to improve the electrochemical activity of graphite felt as the positive electrode in all vanadium redox flow battery (VRFB). The graphite felt was treated by microwave and characterized by Fourier transform infrared and scanning electron microscopy. The electrochemical performance of the prepared electrode was evaluated with cyclic voltammetry and electrochemical impedance spectroscopy. Results show that graphite felt treated by microwave for 15 min at 400 °C exhibits excellent electro-catalytic activity and reactive velocity to vanadium redox couples. The coulombic, voltage, and energy efficiency of the VRFB with as-prepared electrodes at 50 mA cm−2 are 96.9%, 75.5%, and 73.2%, respectively; these values are much higher than those of cell-assembled conventionally and thermally treated graphite felt electrodes. The microwave-treated graphite felt will carry more hydrophilic groups, such as –OH, on its defects, and rough degree of the surface which should be advantageous in facilitating the redox reaction of vanadium ions, leading to the efficient operation of a vanadium redox flow battery. Moreover, microwave treatment can be easily scaled up to treat graphite felt for VRFB in large quantities. | battery |
Diabetes is a debilitating illness requiring lifelong management. Treatments can be varied in terms of mode of administration as well as type of agent. Unfortunately, most patient reported outcome measures currently available to assess the impact of treatment are specific to diabetes type, treatment modality or delivery systems and are designed to be either a HRQoL or treatment satisfaction measure. To address these gaps, the Treatment Related Impact Measure-Diabetes and Device measures were developed. This paper presents the item development and validation of the TRIM Diabetes/Device. | non-battery |
The Irish government set a target in 2008 that 10% of all vehicles in the transport fleet be powered by electricity by 2020. Similar electric vehicle targets have been introduced in other countries. In this study the effects of 213,561 electric vehicles on the operation of the single wholesale electricity market for the Republic of Ireland and Northern Ireland is investigated. A model of Ireland’s electricity market in 2020 is developed using the power systems market model called PLEXOS for power systems. The amount of CO2 emissions associated with charging the EVs and the impacts with respect to Ireland’s target for renewable energy in transport is also quantified. A single generation portfolio and two different charging scenarios, arising from a peak and off-peak charging profile are considered. Results from the study confirm that off-peak charging is more beneficial than peak charging and that charging EVs will contribute 1.45% energy supply to the 10% renewable energy in transport target. The net CO2 reductions are 147 and 210 kt CO2 respectively. | battery |
Anterograde amnesia is a severely disabling state which has been reported as a consequence of bilateral mesiotemporal lesions in humans. In the present paper, recurrent epileptic seizures after temporal lobectomy are described as a rare cause of severe amnesia in two patients. Diffusion-weighted MRI in one patient showed cytotoxic edema during a nonconvulsive status epilepticus and subsequent progressive hippocampal atrophy within the following month. In the other patient, repeated conventional MRI revealed no structural abnormalities in the contralateral temporal lobe. | non-battery |
Electrochemical properties and porous-structure-dependent capacitive ability of commercial carbon blacks, Black Pearls 2000® (BP) and Vulcan® XC 72R (XC), were investigated in H2SO4 solution by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The capacitance in-depth profile is correlated to microscopic appearance of carbon blacks in the form of a thin layer applied over Au substrate from water suspensions of BP and XC. The capacitance calculated from voltammetric charge was found to depend on the sweep rate, due to porosity of investigated materials. Impedance (EIS) characteristics upon frequency-dependent charge/discharge process indicate transmission line electric behavior of BP and XC. Capacitance and resistance values obtained by simulations of EIS data, enabled estimation of capacitance and resistance profile throughout carbon black porous electrodes. Capacitance of BP carbon layer increases going from the outer surface towards the bulk of the layer. External capacitance originates from capacitive characteristics of the macroscopic surface consisting of relatively large agglomerates, while internal capacitance originates from “inner” surface of micro-porous agglomerates. Contrary to BP, opposite distribution of the total capacitance to external and internal part was found for XC, caused by its loose structure and considerably lower real surface area in comparison to BP. The XC morphology makes additionally the pseudocapacitive contribution of surface functionalities more pronounced, which indirectly shifts also the “internal” double-layer capacitive response to higher frequencies through the effect of increased wettability of the layer. Thus, the capacitance of XC surface directly exposed to the electrolyte is larger than that of the inner one, which makes it a “fully-utilized” capacitor, while increased capacitive performance of BP emerges only at very low frequencies of charging/discharging process. | battery |
Behavioral symptoms of comorbid psychopathology of 651 children 17–37 months of age who were at risk for developmental disabilities were studied using the BISCUIT-Part 2. In Study 1, norms and cutoff scores were established for this new scale on this sample. In Study 2, frequency of response on the 52 items measured was reported. Problems in eating and sleep were the most common with just over15% of the sample experiencing these difficulties of either a moderate or severe nature. For severe problems, the most commonly reported difficulties were inattention/impulsivity, and tantrums/conduct behavior problems. Implications of this scale and these data for early identification of behavior disorders in atypically developing children are discussed. | non-battery |
This article presents the results obtained from the analysis of the I–V electrical characteristics of photovoltaic arrays that were tested in a region of the Sahara. Experiments were carried out at Adrar in the southern part of Algeria. The study includes the determination of the most representative parameters of the arrays by using numerical methods for the one exponential model. After having determined these parameters, they were numerically used in order to carry out the plotting of the theoretical I–V characteristics of modules for the considered environmental variables such as ambient temperature and solar irradiance. Other model (Rauschenbach's model) has also been considered in this article to make a comparison with the previous one. The study has been completed by carrying out the translation of the experimental characteristics for the standard conditions. This translation allowed the comparison to be made between the performances of tested modules. In the last part of the paper, some elements related to the degradation of arrays performances have been presented. | battery |
This paper reviews approaches to the design of advanced electrolyte solutions for Li and Li-ion batteries. Important challenges are wide electrochemical windows, a wide temperature range of operation, acceptable safety features, and most important, appropriate surface reactions on the electrodes that induce efficient passivation, but not on the account of low impedance. We describe research tools, quick tests, and discuss some selected examples and strategies for R&D of solutions of improved performance. | battery |
While the heterogeneity of developmental dyscalculia is increasingly recognized, the different profiles have not yet been clearly established. Among the features underpinning types of developmental dyscalculia suggested in the literature, an impairment in arithmetic fact retrieval is particularly prominent. In this paper, we present a case study of an adult woman (DB) with very good cognitive capacities suffering from a specific and developmental arithmetic fact retrieval deficit. We test the main hypotheses about developmental dyscalculia derived from literature. We first explore the influential hypothesis of an approximate number system deficit, through estimation tasks, comparison tasks and a priming comparison task. Secondly, we evaluate whether DB's mathematical deficiencies are caused by a rote verbal memory deficit, using tasks involving completion of expressions, and reciting automatic series such as the alphabet and the months of the year. Alternatively, taking into account the extreme similarity of the arithmetic facts, we propose that a heightened sensitivity to interference could have prevented DB from memorizing the arithmetic facts. The pattern of DB's results on different tasks supports this hypothesis. Our findings identify a new etiology of a specific impairment of arithmetic facts storage, namely a hypersensitivity-to-interference. | non-battery |
Well-crystallized LiFePO4 nanoparticles have been directly synthesized in a short time via hydrothermal process in the presence of organic acid, e.g. citric acid or ascorbic acid. These acid-mediated LiFePO4 products exhibit a phase-pure and nanocrystal nature with size about 50–100nm. Two critical roles that the organic acid mediator plays in hydrothermal process are recognized and a rational mechanism is explored. After a post carbon-coating treatment at 600°C for 1h, these mediated LiFePO4 materials show a high electrochemical activity in terms of reversible capacity, cycling stability and rate capability. Particularly, LiFePO4 mediated by ascorbic acid can deliver a capacity of 162mAhg−1 at 0.1C, 154mAhg−1 at 1C, and 122mAhg−1 at 5C. The crystalline structure, particle morphology, and surface microstructure were characterized by high-energy synchrotron X-ray diffraction (XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM), and Raman spectroscopy, respectively. And the electrochemical properties were thoroughly investigated by galvanostatic test and electrochemical impedance spectroscopy (EIS). | battery |
This paper proposes a novel solid oxide steam electrolyser with in-situ hydrogen storage by integrating a magnesium hydride (MH) section with proton-conducting solid oxide electrolysis cell (SOEC) section. Dynamic simulation results show that it takes 1950 s to fully charge the MH section with a 56% H2 storage efficiency without any flow recirculation, when the electrolyser is operated at 1.4V and 4atm, yielding a current density of 4956.40 A/m2. The evolution of temperature, H2 partial pressure and reaction of Mg powder through the charging process are analysed. It is found that the exothermic H2 absorption process of MH section can enhance the performance of the electrolysis process of SOEC section. The effects of operating parameters including operating pressure, electrolysis voltage, and cooling air temperature on the performance of the novel design are investigated by sensitivity studies. Results show that it is beneficial to operate the electrolyser at elevated pressure for shorter absorption time and higher H2 storage efficiency. Increasing the operating voltage can shorten the absorption time, but lower H2 storage efficiency. An optimal cooling air temperature is found at 521K when the electrolyser is operated at 1.4V and 4atm. | battery |
The impulsive behavior that is often characteristic of adolescence may reflect underlying neurodevelopmental processes. Moreover, impulsivity is a multi-dimensional construct, and it is plausible that distinct brain networks contribute to its different cognitive, clinical and behavioral aspects. As these networks have not yet been described, we identified distinct cortical and subcortical networks underlying successful inhibitions and inhibition failures in a large sample (n = 1,896) of 14-year-old adolescents. Different networks were associated with drug use (n = 1,593) and attention-deficit hyperactivity disorder symptoms (n = 342). Hypofunctioning of a specific orbitofrontal cortical network was associated with likelihood of initiating drug use in early adolescence. Right inferior frontal activity was related to the speed of the inhibition process (n = 826) and use of illegal substances and associated with genetic variation in a norepinephrine transporter gene (n = 819). Our results indicate that both neural endophenotypes and genetic variation give rise to the various manifestations of impulsive behavior.
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Solid-state lithium batteries have become more important than ever, because their high reliability as well as high energy density meet the requirements for energy storage in many aspects of the coming low carbon society. Solid electrolytes with high ionic conductivities are inevitable for realizing the solid-state lithium batteries, and the studies have been focused mainly on sulfide and oxide-based electrolytes. Sulfide-based solid electrolytes are advantageous to batteries owing to their high ionic conductivities and deformability. Although they show high resistance at the interface to cathode materials, interposing thin films of oxide-based solid electrolytes into the interface has successfully reduced the interfacial resistance. Combination of the highly-conductive sulfide electrolyte and the interface design have made performance of the sulfide-type solid-state batteries comparable or superior to current lithium-ion batteries. On the other hand, oxide-based electrolytes show higher chemical stability than sulfides, which is beneficial for manufacturing process. Although the highest conductivities have reached 10−3 S cm−1 also in oxides, practical performance has not been achieved in the oxide system due to the high grain boundary resistance. | battery |
Active middle ear implants (AMEIs) have been available for a number of years and yet most radiologists have never heard of them. Some bear a striking resemblance to cochlear implants whereas others are more similar to conventional hearing aids. The aims of this review are to provide an introduction as to the types of implants available, how they work and when they are indicated. Also, to highlight important pre-operative imaging features that can influence surgery and to consider the role of imaging in the post-operative setting. As patient choice increases, it becomes more likely that radiologists will encounter these devices in daily practice and knowledge of them may prove useful. | non-battery |
The cobalt sulfides/graphene nanosheets (GNS) composite is prepared by a facile one-pot solvothermal route in the presence of graphene oxide sheets (GOS). XRD, SEM and TEM characterizations show that sphere-like cobalt sulfides particles with an average size of about 150 nm, which are complicated phases of CoS2, CoS and Co9S8, are highly dispersed on or wrapped in the creasy graphene. The selective nucleation and growth of cobalt sulfides particles on GOS make the particles more uniform in morphology and size. The as-fabricated cobalt sulfides/GNS composite exhibits very high electrochemical lithium storage reversible capacity of about 1018 mAh g−1. Moreover, the cobalt sulfides/GNS composite still remains reversible capacity of above 950 mAh g−1 after 50 cycles at a current density of 100 mA g−1 as well as at the different current densities from 100 to 1000 mA g−1, proving its excellent cycling durability and high-rate capability. The superior electrochemical performances of the composite may be attributed to the robust composite structure and superior conductivity, high charger mobility, large surface area and good flexibility of graphene. | battery |
This study has been attempted to present the state of art review on the research work carried out for the operation of wind and pumped storage plant (Wind–PSP) under deregulated market. Due to the uncertain characteristics of the wind, power generated by wind turbines is mostly variable and may affect the power system operation. Therefore integrated operation of Wind–PSP requires the knowledge of various factors such as: technology/concept to be used, number and capacity of the generating units, control, management, scheduling and cost of imbalance etc. In order to overcome the effect of variability and above said factors, a joint operation of a wind turbine and energy storage systems (ESS)/technologies is required. Among all the ESSs, PSP is the most mature and large capacity system, which can compensate the wind power uncertainties optimally. Variable operations of PSP, balance the load and generation uncertainty, and thus enhance the ability of power system to incorporate wind power. The present study has been aimed to cover the review of basics of wind energy, PSP, Wind–PSP system and their current status, applications and challenges involved with Wind–PSP, Operation of Wind–PSP under deregulated market and optimization techniques used in the scheduling of Wind–PSP system. An attempt has also been made to compare the techniques suitable for scheduling of Wind–PSP systems based on earlier research. | battery |
It is widely known that intentional non-malevolent violations of safety procedures and norms occur and evidence shows that safety violations can increase the risk of accidents. However, little research about the causes of these violations in work settings exists. To help shed light on the causes, this paper systematically reviews the empirical causes of safety violations in industry. Electronic database literature searches were performed to identify relevant articles published prior to January 1, 2007. Thirteen articles met the inclusion criteria and 57 different variables were examined as predictors of safety violations. Study settings were healthcare delivery, commercial driving, aviation, mining, railroad, and construction. The predictors were categorized into individual characteristics, information/education/training, design to support worker needs, safety climate, competing goals, and problems with rules. None of the reviewed studies examined whether violations can improve system performance or safety. Methodological suggestions and a macroergonomic framework are offered for improving future studies of the epidemiology of safety violations. | non-battery |
To raise the effectiveness of interventions, clinicians should evaluate important biopsychosocial aspects of the patient’s situation. There is limited knowledge of which factors according to the International Classification of Function, Disability, and Health (ICF) are most deviant between patients with knee osteoarthritis (KOA) and healthy individuals. To assist in measures’ selection, we aimed to quantify the differences between patients with KOA and healthy controls on various measures across the ICF dimensions of body function, activity, and participation. | non-battery |
Composite anodes based on SnSb alloy and Li2.6Co0.4N compound can provide a reversible capacity more than 650mAh/g in solid polymer electrolyte. However, the capacity retention on cycling is poor at a high-capacity level. Limited lithium insertion (<500mAh/g) is favorable for the cyclability. Cyclic voltammetry of the composite electrode exhibits good electrochemical reversibility. Because the nano-sized SiO1.1 host has a relatively small volume change effect and different insertion potential from SnSb and Li2.6Co0.4N, its addition in a small amount into the composite electrode can improve the mechanical and cycling stability. | battery |
This paper is an Editorial for the special issue (SI) of Renewable and Sustainable Energy Reviews (RSER) devoted to the 12th Conference on Sustainable Development of Energy, Water and Environment Systems (SDEWES), held from the 4th to 8th October 2017 in Dubrovnik, Croatia. The key focus of RSER is to publish critical thinking across the wide field of renewable and sustainable energy. The journal publishes either pure review papers or research papers with a precise review element. Overall, the guest editors invited 36 papers presented on 12th SDEWES conference, of which 17 were accepted after rigorous peer review process. The SDEWES conferences present a continuous effort in gathering high level scientists and research papers across the field of sustainability and by now the amount of accumulated knowledge, through conference papers and special journal issues, is significant. Each SDEWES journal editorial presents a wider overview of special issue journal papers in order to maintain the continuation of knowledge generation on the main sustainability topics. The main topics covered in this RSER editorial include renewable energies with special focus on integration, markets and roadmaps, energy efficiency in buildings, industrial process and transport, bio based economy focused on bio based chemicals and biofuels, energy storage focused on batteries, thermal and geological storages and various sustainability assessments in several sectors and technologies. All were considered in light of the Circular Economy. | battery |
Although the olfactory receptor neurons converging onto the same glomeruli in the olfactory bulb are known, evidence for an olfactory map at cortical level is lacking. The current study finds that mitral cells that are born later during embryogenesis preferentially project to the olfactory tubercles as the late-born mitral cells tangentially migrate further on the axons of earlier born cells, forming an organization of neuronal projection into the olfactory cortex based on the timing of cell birth. | non-battery |
This paper describes the mathematical parametrization of an electrodynamical battery model using different model selection criteria. A good modeling technique is needed by the battery management units in order to increase battery lifetime. The elements of battery models can be mathematically parametrized to enhance their implementation in simulation environments. In this work, the best mathematical parametrizations are selected using three model selection criteria: the coefficient of determination ( R 2 ), the Akaike Information Criterion ( A I C ) and the Bayes Information Criterion ( B I C ). The R 2 criterion only takes into account the error of the mathematical parametrizations, whereas A I C and B I C consider complexity. A commercial 40 Ah lithium iron phosphate ( L i F e P O 4 ) battery is modeled and then simulated for contrasting. The OpenModelica open-source modeling and simulation environment is used for doing the battery simulations. The mean percent error of the simulations is 0.0985% for the models parametrized with R 2 , 0.2300% for the A I C ones, and 0.3756% for the B I C ones. As expected, the R 2 selected the most precise, complex and slowest mathematical parametrizations. The A I C criterion chose parametrizations with similar accuracy, but simpler and faster than the R 2 ones. | battery |
Remote island communities face problems caused by the continuity and reliability of their power supply, which tend to be exacerbated when they rely on fluctuating renewables. In this paper the sizing of supply-demand-storage schemes is addressed in respect of their economy and feasibility. In the case of the French Atlantic Island of Yeu, high electricity peaks are common, due to tourism and to the seasonal use of second homes. A power plant dispatching model is used to simulate energy scenarios in 2030, subject to the supply-demand power equilibrium and the requirements of hydrogen-powered boats. Interconnected Yeu Island could accommodate 30 MW of renewables without curtailment, ensuring an electricity independence rate of 86% and renewable energy generation rate of 131% in the load, made up of wind (42%), solar (10%), tidal (21%), wave energy (25%) and biomass (2%). Excess energy could be exported through bidirectional cables, which are also the key adjustment variable in the reserve margins. Energy transition costs amount to 112 M€ in renewable-hydrogen projects, and 3 M€ for demand-side measures achieving a 2.7% reduction in load. An island self-sufficient power system with Yeu load characteristics would require at least 40 MW of variable renewables and 1 GWh energy storage capacity, at costs of 1.15 Bln€. | battery |
In order to analyze environmental dynamics, a major process is the classification of the different phenomena of the site (e.g. ice and snow for a glacier). When using in situ pictures, this classification requires data pre-processing. Not all the pictures need the same sequence of processes depending on the disturbances. Until now, these sequences have been done manually, which restricts the processing of large amount of data. In this paper, we present how to realize a semantic orchestration to automate the sequencing for the analysis. It combines two advantages: solving the problem of the amount of processing, and diversifying the possibilities in the data processing. We define a BPEL description to express the sequences. This BPEL uses some web services to run the data processing. Each web service is semantically annotated using an ontology of image processing. The dynamic modification of the BPEL is done using SPARQL queries on these annotated web services. The results obtained by a prototype implementing this method validate the construction of the different workflows that can be applied to a large number of pictures. | non-battery |
A new type of electrochemical cell has been developed for use in electrochemical, chemical and biological applications. Using a platinum microelectrode as working electrode, this cell incorporates a silver microelectrode as reference electrode. These microelectrodes, whose area is equal to 1μm2, were fabricated using photolithography, sputtering, and focused ion beam (FIB) technologies since these micro-fabrication techniques allow us to develop miniaturized electrochemical cells useful either for nanoelectrochemistry or biosensors applications. In this study, we show it is possible to coat a surface by chemical or biological compounds by immersing the microelectrodes in a solution, then setting a difference of potential between the two microelectrodes of the cell. For example, we used this miniaturized cell to realize the electrochemical polymerization of aniline into polyaniline to show that this electrochemical cell is efficient to coat a surface with a thin film of polymer. | battery |
In turf industry, the ability of a cultivar to use less water is an important consideration, especially where rainfall and irrigation water are insufficient. Knowledge of turf grass water-use patterns is therefore important for developing efficient water management practices and also for selection of drought-resistant cultivars. We evaluated the soil water‐use patterns of tall fescue and hybrid bluegrasses cultivars irrigated at different rates. Field experiments were conducted at the Turfgrass Research Facility, Auburn University, AL, in 2005 and 2006. Two tall fescue (Festuca arundinacea Schreb.) cultivars (‘Kentucky 31’ and ‘Green Keeper’) and four hybrid bluegrass (Poa pratensis L. × Poa arachnifera Torr.) cultivars, viz., HB 129 [‘Thermal Blue’], HB 130 (Experimental line), HB 328 (Experimental line) and HB 329 [‘Dura Blue’] were included in this study. Plots were irrigated based on the potential evapotranspiration, viz., 100% ET, 80% ET and 60% ET replacements. Tensiometers were installed at 0.075, 0.15 and 0.30 m depths, and their readings used to calculate the matric head, water content and water-use values. Turf color quality was determined from turf canopy digital images. Analysis of variance (ANOVA) for a random complete block design (RCBD) was conducted for available water, water-use and turf color quality values. Hybrid bluegrasses revealed significantly (P = 0.05) higher turf color indices compared to the tall fescue cultivars, but there was no indication of differential responses to irrigation among cultivars. Based on water-use data, hybrid bluegrass cultivars revealed significantly (P = 0.05) lower water-use compared to tall fescue cultivars. | non-battery |
On the way to sodium-based all-solid-state batteries, interface analysis is a key issue. In this work, the interface between two typical solid sodium-ion conductors (Na-β″-Al2O3 and NASICON) and the layered oxide material NaCoO2 is investigated. The formation of the interface between the electrolyte material and the NaCoO2 coating is studied using an in-situ X-ray photoemission spectroscopy (XPS) surface science approach. Only a slight reduction of zirconium and scandium in NASICON was observed in proximity to the cathode side interface, while severe reactions, including the formation of a CaOAl2O3 mixed phase, were detected between Na-β″-Al2O3 and NaCoO2. | battery |
The supercapacitive performances of Co(OH)2/Ni(OH)2 composites in lithium hydroxide solution are investigated in detail. Cyclic voltammetries and galvanostatic charge/discharge measurements reveal that LiOH is the most suitable electrolyte for the composite electrodes among MOH (M=Li, Na and K). The redox behavior of the Co(OH)2/Ni(OH)2 composites different to that of the pure components shows that weight ratio of Co(OH)2/Ni(OH)2 exerts a great influence on the capacitive performances. After 1000 continuous charge/discharge cycles, the capacitance retention ratio for the composite electrode with the weight ratio of 2/3 is elevated from 41.6% to 88.2% compared with pure Ni(OH)2 electrode, exhibiting improved long-life cyclability. | battery |
The cathode/electrolyte interface stability is the key factor for the cycle life and the safety performance of lithium-ion battery. Triphenylphosphine(TPP) is studied as an additive for film-formation on the cathode electrode. TPP additive can be preferably oxidized than the solvent and then a solid electrolyte interphase (SEI) layer is in-situ formed on the cathode surface and it greatly improves the cycle stability of the cathode at high voltage. The capacity retention for the LiMn2O4 cathode, which is cycled up to 4.8V, is improved from 82% in the blank electrolyte to 93% in the TPP-containing electrolyte after 100 times at the current density of 148mA/g(1C). | battery |
Properties of lithium-ion battery electrodes relate to the complex microstructure that develops during solvent removal. We use cryogenic scanning electron microscopy in combination with broad ion beam slope-cutting (Cryo-BIB-SEM) for the ex-situ imaging of film formation in battery electrodes. Drying of anode films is quenched by cryo-preservation in slushy nitrogen at systematically increasing drying times, followed by SEM imaging under cryogenic conditions. Energy dispersive x-ray spectroscopy (EDS) and image processing of segmented cross-sections are used to analyze the development of component gradients with time. We find electrode films to shrink homogeneously and not in a top-down consolidation process as previously hypothesized. Binder gradients evolve in the liquid phase and initiate solvent diffusion from the bulk to the surface, thereby dragging binder towards the surface. Capillary transport is identified as a fundamental process that directly impacts drying kinetics and binder distribution. | battery |
Energy storage technologies are required to make full use of renewable energy sources, and electrochemical cells offer a great deal flexibility in the design of energy systems. For large scale electrochemical storage to be viable, the materials employed and device production methods need to be low cost, devices should be long lasting and safety during operation is of utmost importance. Energy and power densities are of lesser concern. For these reasons, battery chemistries that make use of aqueous electrolytes are favorable candidates where large quantities of energy need to be stored. Herein we describe several different aqueous based battery chemistries and identify some of the research challenges currently hindering their wider adoption. Lead acid batteries represent a mature technology that currently dominates the battery market, however there remain challenges that may prevent their future use at the large scale. Nickel–iron batteries have received a resurgence of interest of late and are known for their long cycle lives and robust nature however improvements in efficiency are needed in order to make them competitive. Other technologies that use aqueous electrolytes and have the potential to be useful in future large-scale applications are briefly introduced. Recent investigations in to the design of nickel–iron cells are reported with it being shown that electrolyte decomposition can be virtually eliminated by employing relatively large concentrations of iron sulfide in the electrode mixture, however this is at the expense of capacity and cycle life. | battery |
“Theory of mind” (ToM) is the ability to judge the mental states of the self and others. It is currently considered as a part of the broader concept of social cognition, known to influence the social behaviour of patients affected by schizophrenia. Recently it has been hypothesized that the impairment of ToM is a trait that can be detected both in patients with schizophrenia and in non-psychotic relatives of patients, but it still not clear what the contribution of the familial patterns of cognitive impairment is. The aim of this study is to assess parental impairments of ToM performance considering the effects of the neurocognitive abilities known to be impaired in their first-degree relatives and to influence ToM in schizophrenic patients. Patients, their parents and control trios were assessed with the Wisconsin Card Sorting Test (WCST), the Symbol Coding Task and the ToM Picture Sequencing Task. The ANCOVA analysis on 47 trios including a schizophrenic offspring and 47 healthy trios showed a statistically significant poorer performance of patients and their parents in comparison to control trios at Symbol Coding Task and ToM task. Moreover a regression analysis showed that the neuropsychological abilities tested were significant predictors of ToM performance only in patients. Results confirm a ToM impairment among parents of patients with schizophrenia that is not directly correlated to other aspects of neurocognitive functioning. | non-battery |
Personal exposures to carcinogenic polycyclic aromatic hydrocarbons (c-PAHs) bound to airborne particulate matter ⩽2.5 μm (PM2.5) were measured in the context of a large-scale molecular epidemiological study in order to identify the impacts of air pollution on human health. Sampling was carried out in three industrial cities in the Czech Republic: Ostrava, Karvina and Havirov. The city of Prague, exhibiting much lower industrial air pollution but a high level of traffic, served as a control. The first monitoring campaigns were held in winter and were repeated in the summer of 2009. The active personal monitors PV 1.7 for PM2.5-bound c-PAHs were used. Non-smoking city policemen from Prague, Karvina and Havirov, and office workers from Ostrava, participated in the study. All participants completed a personal questionnaire and a time-location-activity diary. The average personal winter exposure to c-PAHs (sum of the eight PAHs—benz[a]anthracene, benzo[a]pyrene, benzo[b]fluoranthene, benzo[g,h,i]perylene, benzo[k]fluoranthene, chrysene, dibenz[a,h]anthracene and indeno[1,2,3-c,d]pyrene) was highest in Karvina, 39.1, followed by Ostrava at 15.1 and Prague at 4.3 ng/m3. The winter levels were significantly higher than the summer values (P<0.001): 4.3 in Karvina, 3.0 in Ostrava, 1.6 in Havirov and 1.0 ng/m3 in Prague. The average personal benzo[a]pyrene winter/summer exposures were: 6.9/0.6 in Karvina, 2.5/0.4 in Ostrava, 0.8/0.1 in Prague and 0.2 ng/m3 in summer in Havirov. In this study, we examined personal exposure to c-PAHs and tested it for associations with potential predictor variables collected from questionnaires, addressing life style factors and day-to-day activities. We found outdoor concentration, environmental tobacco smoke exposure, home heating fuel of coal, wood or gas, frequency of exhaust fan use, cooking and commuting by a car to be the main determinants of personal exposure.
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Metallic melts containing Bi show a certain degree of anomalies in their physical and chemical properties. In order to facilitate computational design of novel Bi–alloys for industrial applications, the phase equilibria, phase diagrams and thermodynamics bases for Bi–Li and Bi–Na binary systems are investigated with the CALPHAD method, using reported experimental characterizations. The associate solution model is introduced to describe the thermodynamic properties of Bi–Li and Bi–Na melts, and two binary associates, e.g. BiLi3 and BiNa3, are taken into consideration. The intermetallic phases involved in such two binary systems are treated as stochiometric phases. Rhombohedral Bi, bcc Li and bcc Na are considered as phases without any solubility. The Gibbs energies of all the involved phases are formulated in this work, which can give satisfactory thermodynamic descriptions for related phase equilibria and phase diagrams. | non-battery |
Lactic acid bacteria were isolated from four different sourdough bread cultures previously investigated for antifungal activity. A total of 116 isolates were obtained and screened for antifungal activity against a battery of molds. The most inhibitory isolate obtained was identified by API 50 CHL and 16s ribosomal RNA genotyping and found to be Lactobacillus paracasei ssp. tolerans. This isolate completely inhibited the growth of Fusarium proliferatum M 5689, M 5991 and Fusarium graminearum R 4053 compared to controls in a dual agar plate assay. | non-battery |
Vanadium flow battery (VFB) has received tremendous attention because of its advantages such as long lifespan, easy to scale and flexible operation. Fabricating novel electrodes with high power density and wide operating temperature is critical to promote the practical application of VFB for all-climate energy storage. In this work, we describe a well-controlled method to prepare holey-engineered porous graphite felt (PGF) electrodes, in which nanosized pores are evenly distributed on the microscale graphite fibers of the graphite felt. Owing to its excellent electrolyte wettability and greatly enhanced surface area, the as-prepared PGF electrode exhibits high electrochemical activity towards VO2+/VO2 + and V2+/V3+ redox couples. As a result, the VFB single cell assembled with PGF electrodes demonstrates outstanding rate performance under current density up to 300mAcm−2. The resulting PGF electrode also exhibits superior long-term stability over 3000 charging-discharging cycles at a high current density of 150mAcm−2, and wide temperature adaptability from − 20°C to 60°C. | battery |
We synthesized polycrystalline ZnFe2O4 nanofibers via a facile electrospinning and annealing process. The ZnFe2O4 nanofibers exhibit continuous frameworks and uniform porosity through the abrupt combustion of the polymer and crystallization of inorganic elements. This well-defined structure and morphology facilitates Li+ transport, enhances the effective contact area with the electrolyte, and offers abundant active sites. For the ZnFe2O4 nanofiber anode, the reversible capacity reaches 753 mAh g−1 after 200 cycles at the high current density of 5 A g−1 and the anode shows excellent rate performance. The enhanced electrochemical performance can be attributed to the one-dimensional nanostructure and shortened diffusion pathways, which ensure full conversion reactions during lithiation-delithiation between Zn, Fe, and Li+, relieve volume expansion, and prevent pulverization/aggregation upon prolonged cycling at high current densities. Thus, we believe that ZnFe2O4 nanofibers present great potential as anode materials for Li-ion batteries. | battery |
We demonstrate potential application of a new composite non-woven separator, which is comprised of a phase inversion-controlled, microporous polyvinylidene fluoride-hexafluoropropylene (PVdF-HFP) gel polymer electrolyte and a polyethylene terephthalate (PET) non-woven support, to high-voltage and high-power lithium-ion batteries. In comparison to a commercialized polyethylene (PE) separator, the composite non-woven separator exhibits distinct improvements in microporous structure and liquid electrolyte wettability. Based on the understanding of the composite non-woven separator, cell performances of the separator at challenging charge/discharge conditions are investigated and discussed in terms of ion transport of the separator and AC impedance of the cell. The aforementioned advantageous features of the composite non-woven separator play a key role in providing facile ion transport and suppressing growth of cell impedance during cycling, which in turn contribute to superior cell performances at harsh charge/discharge conditions such as high voltages and high current densities. | battery |
Research has revealed the desirable characteristics to be gained from combining PM matrix composites with other materials - and the difficulties involved in manufacturing such products at a reasonable price. Joe Capus reports on a session at last Autumn's Euro PM World Congress in Vienna… | non-battery |
Phase pure, homogeneous, and well-crystallized lithium iron phosphate LiFePO4 was synthesized by aqueous co-precipitation of an Fe(II) precursor material and succeeding heat treatment in nitrogen. The particle morphology of the precursor is preserved during the heat treatments. Excellent electrochemical properties in terms of capacity, reversibility, cycling stability and rate capability have been achieved. The thermal stability of charged electrodes is superior versus other positive electrode materials. If reductive synthesis conditions are used in the heat treatments, problems arise from the possible generation of iron phosphide. | battery |
Lithium–nickel–cobalt–manganese oxide, Li[Ni x Co y Mn z ]O2 (NCM) is a low-cost cathode material with a high capacity and a moderately high rate capability, however, it still suffers from poor electrochemical performance. In this study, several types of additives are attempted to enhance the surface stability of high-Ni-content (Ni ≥ 60%) cathodes and the most effective additive turns out to be PS. The cycle performance in the presence of 2% PS is much improved at a high temperature of 60 °C: (1) 98.9% of its initial capacity is preserved, (2) the increase in thickness is only 17.9%, preventing undesired swellings, and (3) gases are not generated in large amounts with the internal pressure being 56.4 kPa. The FT-IR spectroscopy results suggest that the surface of the cathode in the presence of 2% PS is covered with a film of alkyl sulfone components (RSOSR and RSO2SR), which is possibly formed by the electrochemical oxidation of PS. The current results confirm that the electrochemical performance of Ni-rich cathodes can be improved via the appropriate use of additives. They also indicate that among the tested additive candidates in this study, PS is highly desirable for enhancing the electrochemical performance of Ni-rich cathodes. | battery |
Pure LiFePO4 (LFP) thin films with different thicknesses are deposited at room temperature by a radio frequency (RF) magnetron-sputtering process. Ti foils with and without titanium nitride (TiN) coating as well as thermally oxidized Si wafers coated with Ti or TiN are used as substrates. In a subsequent annealing step, LiFePO4 thin films are crystallized at 500 °C. The interaction between Ti and LiFePO4 as well as between TiN and LiFePO4 is characterized by means of X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive X-ray analysis (EDX), secondary ion mass spectrometry (SIMS), cyclic voltammetry (CV) and galvanostatic measurements. A severe diffusion of Ti into LiFePO4 is found and leading to the formation of impurity phases which resulting in disturbing crystallization behaviour and rough surfaces. Moreover, 80 nm LiFePO4 thin films do not show the desired electrochemical characteristics when they are deposited on Ti foils directly. By using a TiN interlayer, the diffusion of Ti into LiFePO4 can be blocked resulting in smooth morphologies and improving crystallisation behaviour. Impurity phases do not develop and all samples exhibit the expected electrochemical characteristics. Therefore, TiN is a promising candidate for the use as a current collector in all-solid-state batteries with LiFePO4 electrodes. | battery |
A series of expanded graphitic materials are prepared from two different precursors: micrometric synthetic graphite and graphitized carbon nanofibers, and tested as anodes for sodium-ion batteries. The materials preparation involves the oxidation of the precursors followed by partial thermal reduction. Overall, the expanded synthetic graphite materials show better electrochemical performance as anode than the expanded graphite nanofibers, providing higher specific capacity, leading to lower capacity losses in the first discharge-charge cycle and exhibiting outstanding cycling stability. Specific capacities of ∼150mAhg−1 at 37mAg−1 and ∼110mAhg−1 at 100mAg−1 are attained, and up to 50% of the initial capacity at 19mAg−1 is kept at 372mAg−1. Unexpectedly, higher capacity losses are measured for the nanostructured electrodes by progressively increasing the current density. These differences are attributed to the lower surface area and porosity of expanded synthetic graphite materials which favors the formation of thinner and more stable SEI, thus reducing the electrode resistance and enhancing the accessibility of Na+ ions to surface oxygen-containing functional groups with the consequent increase of the surface capacity which was found to be the main contribution to the total specific capacity. | battery |
Gel polymer electrolyte films based on thermoplastic polyurethane (TPU)/poly(vinylidene fluoride) (PVdF) with and without in situ ceramic fillers (SiO2 and TiO2) are prepared by electrospinning 9wt% polymer solution at room temperature. The electrospun TPU–PVdF blending membrane with 3% in situ TiO2 shows a highest ionic conductivity of 4.8×10−3 Scm−1 with electrochemical stability up to 5.4V versus Li+/Li at room temperature and has a high tensile strength (8.7±0.3MPa) and % elongation at break (110.3±0.2). With the superior electrochemical and mechanical performance, it is very suitable for application in polymer lithium ion batteries. | battery |
There are currently no known acoustic parameters by which stuttering children can be appraised in order to predict the further course of their speech disfluency. The present study investigates the usefulness of a computer-based speech analysis of fluent utterances. Correlations between acoustic variables, severity, and course of stuttering were sought in a prospective longitudinal study. This analyzed 57 preschool children at 6-month intervals over a period of 4.6 years. The acoustic analyses yielded no clearly distinguishing characteristics. There was, however, one subgroup consisting of children who were still disfluent at study end which showed more variable values at various measurement points for different parameters. Speech control seems to be different in children exhibiting chronic stuttering. | non-battery |
Although many research efforts have been devoted to improving the electrochemical performance of ZnCo2O4, there is still a great need for a facile, low cost and time-saving method to synthesize ZnCo2O4. Herein, we first report a facile method to prepare mesoporous ZnCo2O4 with polypyrrole (PPy) coating (ZnCo2O4/PPy). The facile strategy involves a reflux method and a subsequent chemical polymerization method. The mesoporous ZnCo2O4/PPy shows an outstanding electrochemical performance. The discharge capacity of the ZnCo2O4/PPy is 615 mAh g−1 after 100 cycles at a current density of 0.1 A g−1. When the current density increases to 0.2 A g−1, the discharge capacity still retains 458 mAh g−1 after 100 cycles. The improved electrochemical performance is attributed to the coating of PPy layer, which acts as a conductive agent and buffer during charge/discharge. Our results demonstrate that the ZnCo2O4/PPy has potential as a high-energy anode material for lithium-ion batteries. | battery |
In recent years, the share of renewable energy sources (RES) in the electricity generation mix has been expanding rapidly. However, limited predictability of the RES poses challenges for traditional scheduling and dispatching mechanisms based on unit commitment (UC) and economic dispatch (ED). This paper presents an advanced UC-ED model to incorporate wind generators as RES-based units alongside conventional centralized generators. In the proposed UC-ED model, an imbalance cost is introduced reflecting the wind generation uncertainty along with the marginal generation cost. The proposed UC-ED model aims to utilize the flexibility of fleets of plug-in electric vehicles (PEVs) to optimally compensate for the wind generation uncertainty. A case study with 15 conventional units and 3 wind farms along with a fixed-sized PEV fleet demonstrates that shifting of PEV fleets charging at times of high wind availability realizes generation cost savings. Nevertheless, the operational cost saving incurred by controlled charging appears to diminish when dispatched wind energy becomes considerably larger than the charging energy of PEV fleets. Further analysis of the results reveals that the effectiveness of PEV control strategy in terms of CO2 emission reduction is strongly coupled with generation mix and the proposed control strategy is favored in cases where less pollutant-based plants like nuclear and hydro power are profoundly dominant. | battery |
Energy storage in PV cooling systems is desirable to supply on-site loads during solar outages. Current storage methods of such systems typically use battery storage to store surplus electricity generated by solar panels or coolth thermal energy storage (CTES) to store excess cooling capacity produced by an electric-driven chiller. This study compares three cooling system configurations – no energy storage, with a battery storage, and with a phase change CTES, for a residential building under the climate of Shanghai, Madrid and Brisbane. System simulation of each configuration was conducted using TRNSYS. A CTES component was programmed externally using effectiveness-NTU method. Both energy storage methods were compared with regard to energy change during a summer day, power consumption and primary energy saving ratio (PESR) during the cooling season. In addition, performance of a single battery and a single CTES were evaluated under various operational conditions. The results showed good energy performance of both storage cases. The PESR of battery case and coolth storage case were 2.8 times and 1.9 times higher than that of a reference case with no energy storage. | non-battery |
A homogeneous nanocomposite of SnSe and carbon black, denoted as SnSe/C nanocomposite, was fabricated by high energy ball milling and empolyed as a high performance anode material for both sodium-ion batteries and lithium-ion batteries. The X-ray diffraction patterns, scanning electron microscopy and transmission electron microscopy observations confirmed that SnSe in SnSe/C nanocomposite was homogeneously distributed within carbon black. The nanocomposite anode exhibited enhanced electrochemical performances including a high capacity, long cycling behavior and good rate performance in both sodium-ion batteries (SIBs) and lithium-ion batteries (LIBs). In SIBs, an initial capacitiy of 748.5mAhg−1 was obtained and was maintained well on cycling (324.9mAhg−1 at a high current density of 500mAg−1 in the 200 th cycle) with 72.5% retention of second cycle capacity (447.7mAhg−1). In LIBs, high initial capacities of approximately 1097.6mAhg−1 was obtained, and this reduced to 633.1mAhg−1 after 100cycles at 500mAg−1. | battery |
Detection of feigned neurocognitive deficits is a challenge for neuropsychological assessment. We conducted two studies to examine whether memory malingering is characterized by an elevated proportion of false negatives during yes/no recognition testing and whether this could be a useful measure for assessment. | non-battery |
The electrochemical performances of fluorinated graphite have been improved by coating a uniform carbon layer on commercial CF x (x =1) powder used as cathode material in lithium battery. In comparison with the cell using un-coated CF x as cathode, the cell using carbon coated CF x cathode has a higher energy density and higher power density, particularly at higher discharge current rates (1C above). This is because the conductive carbon coating provides the exterior connectivity between particles for facile electron conduction, resulting in high rate performance. | battery |
Previous attempts to measure material well-being or hardship have not made clear the relationship of individual items to the broader concept of hardship. The current study used the Survey of Income and Program Participation (SIPP), a large-scale U.S. survey with a large number of questions on the material circumstances of households to create a measurement model of hardship that takes this relationship into account. A higher-order model with five-first-order factors: consumer durables, resources available to meet needs, housing conditions, neighborhood problems and crime, and community services, and a single second-order factor hardship fit the data well, with the “Housing” and “Neighborhood” first-order factors most strongly related to the higher-order hardship construct. Despite our attempts to tie the hardship measures to objective conditions, subjective evaluations were strongly related to most of the factors.
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Spinel Li4Ti5O12 known as a “zero-strain” anode material for Li-ion battery has attracted much attention because of its superior safety and stability. Herein, we report a novel H2O2-assisted one-step hydrothermal method to synthesize different ratio Li4Ti5O12/TiO2 composites with the same amount of raw materials. For the first time, Li4Ti5O12 was prepared directly from commercial titania with the presence of H2O2, and different proportion Li4Ti5O12/TiO2 composites were fabricated only by adjusting the amount of H2O2. The reaction mechanism of the novel H2O2-assisted method was clearly investigated, and H2O2 plays a crucial role in the formation of intermediate Li1.81H0.19Ti2O5·2H2O. Further, the electrochemical performance of different ratio Li4Ti5O12/TiO2 composites have been investigated. This facile method is also applicable for the preparation of Na2Ti6O13/TiO2 material, and provides us the new way to fabricate composite materials. | battery |
Continuous free-standing Carbon Nanotubes (CNTs)/Titanium oxide (TiO2) composite films were fabricated in a vertical CVD gas flow reactor with water sealing by the One-Step Chemical Vapor Deposition (CVD) approach. The composite films consist of multiple layers of conductive carbon nanotube networks with titanium oxide nanoparticles decorating on carbon nanotube surface. The as-synthesized flexible and transferrable composite films show excellent electrochemical properties, when the content of tetrabutyl titanate is 19.0wt.%, which can be promising as binder-free anodes for Lithium-Ion Battery (LIB) applications. It demonstrates remarkably high rate capacity of 150mAhg−1, as well as excellent high rate cyclic stability over 500 cycles (current density of 3000mAg−1). Such observations can be attributed to the relatively larger surface area and pore volume comparing with pristine CNT films. Great potentials of CNTs/TiO2 composite films for large-scale production and application in energy devices were shown. | battery |
Hyperactivity is currently considered a core and ubiquitous feature of attention-deficit/hyperactivity disorder (ADHD); however, an alternative model challenges this premise and hypothesizes a functional relationship between working memory (WM) and activity level. The current study investigated whether children’s activity level is functionally related to WM demands associated with the domain-general central executive and subsidiary storage/rehearsal components using tasks based on Baddeley’s (Working memory, thought, and action. New York: Oxford University Press 2007) WM model. Activity level was objectively measured 16 times per second using wrist- and ankle-worn actigraphs while 23 boys between 8 and 12 years of age completed control tasks and visuospatial/phonological WM tasks of increasing memory demands. All children exhibited significantly higher activity rates under all WM relative to control conditions, and children with ADHD (n = 12) moved significantly more than typically developing children (n = 11) under all conditions. Activity level in all children was associated with central executive but not storage/rehearsal functioning, and higher activity rates exhibited by children with ADHD under control conditions were fully attenuated by removing variance directly related to central executive processes.
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1M NaClO4 and 1M NaPF6 electrolyte solutions in ethylene carbonate–dimethyl carbonate solvent mixture (1:1 by volume) were studied for the possible application in electrical double layer capacitors (EDLCs) with carbide-derived carbon electrodes (synthesized from Mo2C). Two- and three-electrode test cells were electrochemically characterized by using cyclic voltammetry, constant current charge/discharge and electrochemical impedance spectroscopy methods. Region of ideal polarizability, values of series capacitance, high-frequency resistance, time constants, etc. have been established. Based on the specific energy and power calculations, and other characteristics, it was found that the Na-salts based EDLC test cells have similar electrochemical behavior compared to LiPF6 and LiClO4 based systems that have been studied earlier. The studied Na-salts based electrolytes are potential candidates for EDLCs, however, future improvement of the cyclability is inevitable to achieve long-lasting high performance. | battery |
With increases of display resolution and graphical quality demands, global illumination techniques are sought after to meet such demands. However, global illumination algorithms have a long processing time on mobile devices, such as smartphones or tablet PCs. Besides the performance issue, the algorithms consume a large amount of battery-powered energy. The performance and energy consumption have a trade-off relationship. The dynamic voltage and frequency scaling (DVFS) algorithms control the balance between the performance and the energy consumption by adjusting the GPU and CPU’s frequencies. To improve the performance of the global illumination algorithm and reduce the high energy consumption of the current DVFS algorithm, we suggest new algorithms with new metrics for estimating the amount of workload for GPUs as well as their memory workload. Using our new DVFS algorithms, we increase the energy efficiency, the performance per watt, of a global illumination algorithm by 33.59% in comparison to a conventional general-purpose DVFS algorithm, without modifying the underlying algorithm core. | non-battery |
In this work, sodium doped LiVO3 cathode is proposed to achieve enhanced cycling performance for lithium ion battery (LIB) application. LixNa2-xV2O6 (x = 2, 1.4, 1, 0) compounds have been prepared and characterized, and X-ray diffraction patterns confirmed the successful Na doping with various amounts in the LiVO3. The electrochemical performances of the various Na doped compounds LiVO3, Li1.4Na0.6V2O6, LiNaV2O6, and NaVO3 are evaluated by cyclic voltammetry, galvanostatic charge/discharge and electrochemical impedance spectroscopy. The results reveal that Na-doping amount strongly affects the electrochemical performance, and LiNaV2O6 (x = 1) is considered as the optimized Na doped compound for LIB cathodes. The LiNaV2O6 cathode displays enhanced cycling and rate performances as a specific capacity of 193 mAh g−1 at 0.5 C after 100 cycles is delivered. The enhanced performance is explained that the doping of Na can provide good channels and increase Li+ diffusion coefficient for lithium ion intercalation/deintercalation. | battery |
High-voltage stability of LiBF4 - propylene carbonate solutions in intermediate concentration range is studied by means of cyclic voltammetry, galvanostatic cycling and X-ray photoelectron spectroscopy using LiCoPO4 and LiNi0.5Mn1.5O4 cathode materials. Coulombic efficiency improves with increasing salt-to-solvent molar ratio from 1:12 to 1:4 (∼0.8 m–2.5 m solutions), reaching 98% at 1C charge/discharge rate for 1:4 electrolyte upon cycling of LiNi0.5Mn1.5O4 up to 5 V vs. Li/Li+. The same positive trend is observed for discharge capacities, cycling stability and capacity scattering for both high-voltage cathode materials. X-ray photoelectron spectroscopy of the electrodes studied after cycling in solutions of different concentrations does not reveal any drastic difference in surface composition. Interface pre-formation experiment shows that the presence of the interface layer formed at semi-concentrated 1:4 electrolyte does not have a major impact on the electrochemical properties of the dilute solution. We assume that the enhanced oxidation stability of the concentrated solutions itself is a reason of improving the electrochemical performance rather than the cathode-electrolyte interface properties. | battery |
Malnutrition and cachexia have a negative impact on the course of treatment in patients with head and neck squamous cell carcinoma (HNSCC). Good evidence exists for the practical use of the bioelectrical impedance analysis (BIA) parameter phase angle (PA) for the evaluation of nutritional and overall health status in cancer patients. In the present study, two hypotheses were tested: that PA can distinguish between malnutrition and cachexia; in non-cachectic patients, pre-treatment PA is predictive for cachexia development during (chemo)radiation. | non-battery |
By varying Co:Sb molar ratio, crystalline CoSb2O4 was synthesized through surfactant free hydrothermal method. The tetragonal crystal structure and phase composition of cobalt antimonate were obtained through XRD Rietveld refinement method. CoSb2O4 exhibits a direct band gap of 2.89 eV was computed using First-principle density functional theory (DFT) calculations. Here, the Fermi energy level is upshifted to conduction band region, representing the n-type behaviour of the CoSb2O4 unit cell. The oxidation state of +2 and + 3 of Co was identified through X-ray photoelectron spectroscopy analysis (XPS). Formation of submicron size, rod shape particles was confirmed by Transmission electron microscopic (TEM) images. Cyclic voltammogram exhibits a specific capacitance of 598 F g−1 at 2 mV s−1 in 1 M KOH. More importantly, Galvanostatic charge-discharge analysis (GCD) delivered the specific capacitance of 382 F g−1 at 1 mA cm−2. For practical application, an asymmetric supercapacitor is constructed using Ni3(Fe(CN)6)2(H2O) as a positive electrode and synthesized one-dimensional CoSb2O4 as a negative electrode, which offered a maximum specific capacitance of 279 Fg-1 at 1 mV s−1. Cycling stability of the fabricated device demonstrated the retention of almost 100% and hence depicts its promising nature as an efficient electrode for supercapacitor application. | battery |
A nanostructured composite with overall atomic composition Ni0.14Sn0.17Si0.32Al0.037C0.346 has been prepared combining powder metallurgy and mechanical milling techniques for being used as anode material in Li-ion battery. Chemical and structural properties of the nanocomposite have been determined by X-ray diffraction (XRD), 119Sn Transmission Mössbauer Spectroscopy (TMS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The composite consists of Si particles with typical size ∼150nm embedded in a poorly crystallized and complex multielemental matrix. The matrix is composed mostly by Ni3.4Sn4, and disordered carbon. Electrochemical evaluation shows a high reversible capacity of 920mAhg−1, with reasonable reversible capacity retention (∼0.1% loss/cycle) over 280 cycles. | battery |
Unknown | non-battery |
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