The present invention relates to a scan head for a scanning probe microscope arranged for moving a probe including a conductive cantilever relatively to a substrate surface, the head comprising: a first electrode positioned such that a capacitor is formed across a gap between the first electrode and a second electrode, wherein the second electrode is formed by the conductive cantilever; a voltage source for actuating the conductive cantilever by applying a voltage to the capacitor; and at least a first resistor arranged in series between the voltage source and one of the first and second electrodes such as to form an RC circuit for damping a vibration of the cantilever.

SPM includes atomic force microscopy (AFM) and its variations relate to measurement methods that allow for the probing of a wide range of surface properties including surface topography, and various physical and mechanical properties. These include, but are not limited to, local stiffness, elasticity, friction, magnetic, electric and other properties. Typically, in scanning probe microscopy a flexible cantilever including a sharp probe tip is brought into proximity to the surface of a sample to be probed. By detecting the cantilever position, the extent of these forces between tip and cantilever may be determined. By closing a feed-back loop the vertical position of the cantilever may be controlled based on the observed deflection signals.
A disadvantage of known conventional scanning methods is that these are comparatively slow when compared to other surface characterization methods such as electron microscopy. This is on one hand due to the scanning nature of SPM methods which require a scanning motion of the cantilever, sequentially addressing all regions of interest of the sample. On the other hand, scanning speed is limited by the requirement of SPM methods to have the probe tip follow the surface topology as closely, or accurately as possible. A first factor contributing to the limited scanning speed of SPM method relates to the limited response speed of the actuator, typically a vertical piezo electric element, controlling the distance between cantilever and substrate. By reducing the scanning speed, the actuator is left with more time to allow the probe tip to accurately follow the features of the sample. A further factor contributing to the limited scan speed of SPM methods is related to either unwanted cantilever oscillations or the slow rate with which wanted cantilever oscillations change. Unwanted oscillations may, for example, be caused by instantaneous snap-off events between cantilever and substrate causing a cantilever to ring, or oscillate. Such events may for example occur, when the actuator is driven to increase the distance between sample and cantilever. Typically, there exists a certain amount of adhesive forces, e.g. stickiness or water tension, between the probe tip and sample surface. So in order to lift the probe tip from the sample, the cantilever must build up enough energy to overcome these adhesive forces. Once sufficient energy is built up, the probe tip will snap off and the cantilever will start vibrating until the oscillations decay through natural damping. This damping process may last a relatively long time when the cantilever is operating in air because air has a relatively low damping coefficient. As a result, scan speed must be reduced to allow for sufficient damping in order to avoid these vibrations from influencing subsequent measurement runs. Similarly, vibrations or ringing, may be observed during a scanning motion along a sample surface having large pronounced steps in surface properties, e.g. a large depressions, or pronounced spikes. In such case the tip may lose contact with the substrate, or crash into the substrate, respectively, which mat both leave the cantilever in an oscillating state. These problems are further especially pronounced under low pressure conditions, e.g. under vacuum, where damping is even slower. While this tends to increase the sensitivity of the SPM tool, it also becomes much slower. Excessive cantilever vibrations should further be reduced since cantilever vibration may potentially damage the substrate and/or probe tip. In contrast, liquid media, e.g. water, are much more suited for damping of cantilever vibrations. However, not all samples, cantilevers, SPM tools and/or measurement modes are suited for operation under liquid conditions.
Accordingly, there exists a general need for techniques to address the vibrations or ringing of cantilevers in order to improve the speed of probe scanning and/or to improve the speed of generating force-distance curves. In other words there exists a general need for providing an SPM system having a cantilever with decreased Q, for example in SPM methods and devices that intend to measure samples in gaseous atmosphere (although not particularly limited thereto).
U.S. Pat. No. 8,769,710 discloses an atomic force microscope (AFM) and a method of operating an AFM system wherein unwanted vibrations are actively damped. However said method requires both the detection of unwanted vibrations as well as the active damping of these vibrations by applying a control signal to an actuator to counteract these vibrations. In other words, in the system of U.S. Pat. No. 8,769,710 vibrations in the cantilever are damped by applying active counter vibrations. Although the method of U.S. Pat. No. 8,769,710 allows for faster damping of unwanted oscillations in cantilevers the system is still limited by the response speed of the control loop to detect and counteract the vibrations. Further, active damping has limited effectivity and typically some residual oscillations remain. In other words, the method of U.S. Pat. No. 8,769,710 has limited effectivity in providing reduced Q-factors. Further, the method of U.S. Pat. No. 8,769,710 relies on the availability of a transducer to dampen unwanted oscillations and is accordingly limited by the quality and response speed of this actuator.

Scanning probe microscope, scan head and method

Nederlandse Organisatie voor toegepast-natuurwetenschappelijk onderzoek TNO


Three software programs are respectively run on the main processing constituent of a programmable logic controller (PLC), the network-controlling constituent of the PLC, and a human interface unit. Intelligent (e.g., switch, sensor, control, etc.) devices are distributed within a communications network associated with a vertical package conveyor (VPC). Signals are transmitted between/among the processing constituent, the controlling constituent, the interface and the devices. In an ongoing informational and regulative process, the devices provide input for the processing constituent, which in turn provides output to the devices. In furtherance of human safety, the processing constituent causes VPC operation to stop upon the occurrence of any of the following events: breached light curtain; open machinery access door; inoperable run stop button; inoperable emergency stop button; activated emergency stop button; misplaced package. The processing constituent also dictates the direction (up or down) and mode (constant or variable) of the VPC.

The present invention relates to the conveyance or transportation of objects, more particularly to methods and apparatuses for controlling or regulating the operation of devices such as vertical package conveyors.
A "vertical package conveyor" ("VPC") is a conveyance apparatus typically of a kind that includes one or more (usually, many) horizontal tray components that are physically attached to a movable chain, wherein the chain moves vertically, often on a continual basis, so as to transport bulk materials and other packages from one location (e.g., level or floor) to another. Due to their complexity and dynamism, VPCs are intrinsically dangerous, maintenance-intensive and difficult to troubleshoot.
Vertical package conveyors are used aboard some United States Navy ships. According to current Navy practice, vertical package conveyors are associated with a relay controller. A relay type of controller limits the ability to introduce new technology and intelligent sensors to a vertical package conveyance system. A system implementing a relay controller is incapable of being connected to any type of network. Some of the existing electrical components require periodic adjustments to ensure that the system remains reliable and safe. If these adjustments drift or for some reason vary, the conveyor could then have major failures and possibly become unsafe.
The U.S. Navy has customarily predicated its ship maintenance systems on time-directed preventive maintenance principles. Recently, the U.S. Navy has been transitioning in favor of "condition-based maintenance" ("CBM") principles, with a view toward increasing readiness, decreasing maintenance and decreasing manning requirements. Generally, the objective of the U.S. Navy's transformation from time-directed preventive maintenance to condition-directed maintenance is to optimize readiness while reducing maintenance and manning requirements. The underlying concept of condition-based maintenance (synonymously referred to as "condition-directed maintenance") is that the utilization of sensors, algorithms and automated reasoning and decision-making models to monitor equipment operations will provide critical analyses to operators that will help prevent impending failure. "Red flags" will appear to operators so that maintenance efforts can focus limited resources on areas most needed to ensure safety and mission readiness, while at the same time minimizing operating costs, labor and risk of mission-degrading failure. It is anticipated that, at optimal capacity, the U.S. Navy's CBM technology will: detect and classify impending failures; predict the remaining life cycle of equipment; interface with the control system to take action; provide support in performing corrective maintenance; provide data to life cycle management activities; and, update logistics support system. The expectation is that significant improvements in safety, reliability and affordability will ensue.
A "programmable logic controller" ("PLC") is a specialized computer device, typically of rugged construction, that reads input signals, runs control logic, and writes output signals. PLCs have been used in industry for over thirty years for effecting "automation" such as involving the exercise of control of a system of machinery in a manner involving the turning on or off of outputs, based on a state of inputs. Typically used for monitoring important process parameters and adjusting process operations accordingly, a PLC is suitable for assembling and concentrating voluminous data (e.g., status information) that is uploaded therein in a compact form. In earlier times, electrical control was based on relays that allowed power to be switched on and off without a mechanical switch. Relays are still used to make simple logical control decisions, but PLCs are more commonly used for effecting more complicated controls. Programmable logic control typically represents a computerized version of a relay control system that can be used to control manufacturing and other systems. The programming is usually performed using "ladder logic," involving the setting up, inter-linking and timing of sequences in a manner mimicking relay logic.
A relay type of vertical package conveyance control system does not lend itself to incorporation of the CBM philosophy recently instituted by the Navy. Some repairs have resulted in inordinate costs due to the failure of this relay-type control system to identify the degrading conditions of components. It would be desirable to practice a vertical package conveyance methodology that is consistent with CBM values.
The following U.S. patent documents, incorporated herein by reference, are pertinent to vertical package conveyors: Combs U.S. Pat. No. 6,536,582 issued 25 Mar. 2003; Grond U.S. Patent Application Publication 2002/0014392 A1 published 7 Feb. 2002; Rapell U.S. Pat. No. 6,059,521 issued 9 May 2000; Mulhern U.S. Pat. No. 5,718,322 issued 17 Feb. 1998; Grathoff U.S. Pat. No. 5,320,471 issued 14 Jun. 1994; Franke U.S. Pat. No. 5,350,050 issued 27 Sep. 1994; Pfleger U.S. Pat. No. 5,205,379 issued 27 Apr. 1993; Splitstoser et al. U.S. Pat. No. 4,986,411 issued Jan. 22, 1991; Freeman U.S. Pat. No. 4,219,301 issued 26 Aug. 1980; Eklof et al. U.S. Pat. No. 4,020,953 issued 3 May 1977; Henkel U.S. Pat. No. 3,972,412 issued 3 Aug. 1976.

Control algorithm for vertical package conveyor

The United States of America as represented by the Secretary of the Navy


Methods and apparatus for ESD protection of LDMOS devices are provided. The apparatus comprises two LDMOS devices, with source, drain and gate contacts parallel coupled. One is the protected device and the other is the protecting device. Each has source region, drain region, gate, first body well region containing the source, second body well region containing the drain and separated from the first body well region by a drift region, an isolation region separated from the first and second body well regions and a buried layer contacting the isolation region. The protecting device has a further region of the same type as the drain, coupling the drain to the isolation region. Its drain connection is made via a contact to its isolation region rather than its drain region. The drift region of the protecting device is desirably smaller and the isolation-body well separation larger than for the protected device.

LDMOS devices are widely used electronic devices, especially in applications requiring significant power handling capability and as output devices. One of the limitations of LDMOS and similar devices is their sensitivity to electrostatic discharge and similar transients, collectively referred to herein by the acronym "ESD". It is known to use various shunting devices across the output of LDMOS and other semiconductor devices to clamp the voltage appearing thereon to a level below the destructive breakdown voltage of the device. Zener diodes and various types of parasitic semiconductor devices are often employed for this purpose. While such devices may some provide ESD protection for LDMOS devices, they suffer from a number of limitations. For example, the current handling capability of a protective ESD device may be inadequate, it may consume too much area on the device or integrated circuit (IC), it may require a different processing technology that what is used to build the rest of the device or IC, the response time of the ESD device may be too slow to protect against fast transients, the ESD device may show undesirable aging wherein its ability to sustain further transients slowly degrades with time, the properties of the ESD device may undesirably vary with fluctuations inherent in the manufacturing process thereby reducing the overall yield of good devices or ICs, the ESD device may interfere with normal operation of the device or IC it is intended to protect, and so forth. All of these and other limitations may be encountered, depending upon the type of ESD protection device intended to be employed with a particular IC or power device and the semiconductor processing and device technology being used. Accordingly, there is an ongoing need for improved ESD protection devices, especially for use with LDMOS devices and particularly with open-drain LDMOS devices.
Accordingly, it is desirable to provide improved ESD protection for semiconductor devices, especially for LDMOS devices. It is desirable that the means and method for providing ESD protection be process insensitive, that is, the ESD devices be equally or less susceptible to manufacturing process variations than the device or IC being protected. In addition, it is desirable that the means and method for providing ESD protection not require additional and/or more costly manufacturing steps or add a significant area burden to the IC or device being protected. In addition, it is desirable that the ESD device has electrical properties generally compatible with the device or circuit being protected. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.

Process insensitive ESD protection device


Toner and developer compositions contain as charge enhancing components (1) alkyl pyridinium compounds or their hydrates and (2) tetrasubstituted ammonium salts. These toner and developer compositions show improved LC.sub.50 values and are environmentally friendly, and at the same time have very good electrical properties.

The present invention is directed to toners and developer compositions and methods of imaging. More specifically the present invention is directed to toner and developer compositions comprising a combination of charge enhancing additives which is environmentally friendly and has good electrical properties.
Many toner and developer compositions are currently employed in the xerographic art. However, a number of these compositions may pose an environmental hazard, especially to the aquatic environment. Alkyl pyridinium compounds, in particular pure cetyl pyridinium chloride (>99% pure), a component of many toner and developer compositions such as of an aluminum compound of 3,5 dialkyl salicylic acid/CPC containing 7% PV Fast Blue Pigment, 2% an aluminum compound of 3,5 dialkyl salicylic acid, 0.5% cetyl pyridinium chloride and 90.5% styrenebutadiene copolymer and those disclosed in U.S. Pat. Nos. 4,298,672; 5,114,821; 4,752,550 and 5,151,338, may result in undesirable levels in the environment. Such levels are believed to be related to the water extractable alkyl pyridinium level which is the amount of soluble alkyl pyridinium chloride removed from the toner when flushed with water.
Some states of the United States of America, such as California, impose strict regulations on the disposal of materials designated for landfill such as spent xerographic toners. Such materials must pass acute lethal evaluation tests to be classified as non-hazardous. Many current toners containing 2% cetyl pyridinium chloride (CPC) have a LC.sub.50 (lethal concentration to 50% of a population) equal to about 68 mg/1 and may not meet the stringent levels now or soon to be required in some states as well as in some European countries. As a consequence, users of such toner may be confronted with inconvenient and costly waste disposal situations.
Furthermore, positively charged toner compositions having alkyl pyridinium charge enhancing additives are useful in electrostatographic imaging systems such as those which employ a Viton coated fuser roll; however such charge enhancing additives may react with polymers contained on the Viton fuser roll over time causing decomposition of the roll.
One such Viton fuser roll which may be used in electrostatographic copying machines is composed of a soft roll fabricated from lead oxide, du Pont Viton E-430 resin, and vinylidene fluoride hexafluoropropylene copolymer. Excellent image quality has been obtained with such Viton fuser rolls. However, it appears that certain specific charge control additives, such as tetrasubstituted ammonium salts, and alkyl pyridinium compounds, such as cetyl pyridinium chloride, react with the Viton of such Viton fuser rolls. For example, cetyl pyridinium chloride appears to be catalytically decomposed by the lead oxide contained in the fuser roll resulting in a highly unsaturated compound which polymerizes and condenses with the unsaturated Viton E-430 material. As a result, the Viton fuser roll turns black, develops multiple surface cracks, and the surface hardens resulting in image quality deterioration.
Toner compositions comprising the above described charge enhancing additives are useful for causing the development of images formed on layered photoresponsive imaging devices comprised of charge generating and charge transport layers. These devices are charged negatively, rather than positively as is usually the situation with selenium photoreceptors. Thus a toner composition which is positively charged is required in order that the toner particles can be suitably attracted to the electrostatic latent image contained on the photoreceptor surface. In view of this, efforts have been devoted to obtaining developer compositions containing toners which are positively charged. While many charge control additives are known for this purpose, there continues to be a need for new additives. Specifically, there continues to be a need for additives which will not interact with Viton type fuser rolls. Moreover, there continues to be a need for positively charged toner and developer compositions possessing rapid admix charging characteristics. This property allows uncharged toner to rapidly gain charge when introduced into a xerographic developer. Further, there continues to be a need for new charge enhancing additives which can be economically prepared. Additionally, there is a need for substantially non-toxic charge enhancing additives, and a need for charge enhancing additives which can be easily and permanently dispersed in toner resin particles. Also, there is a need for toner compositions with charge stability which can be desirably obtained by extrusion toner processing.
Attempts have been made to remedy such problems by employing toner compositions without alkyl pyridinium compounds such as toner and developer compositions containing mixtures of dimethyl distearyl ammonium methyl sulfate and dimethyl distearyl ammonium bisulfate and as described in U.S. Pat. No. 4,560,635; however sacrificing the advantages of employing alkyl pyridinium compounds. Alkyl pyridinium compounds provide for toners which have conductivities which remain at acceptable levels of greater than or equal to 10.sup.-12 ohm-cm throughout the life of the toner and over as broad a concentration range as possible, typically about 1-4% by weight. This characteristic is thought to be a unique characteristic of toners which contain alkyl pyridinium compounds, in particular halogenated alkyl pyridinium compounds. This is important since environmental conditions and normal toner variation result in tribo fluctuations and corresponding toner concentration fluctuations in xerographic machines.
There is a need for improved toner and developer compositions having the advantages, but not the disadvantages of toner and developer compositions containing alkyl pyridinium compounds.

Toner and developer compositions with pyridinium compounds and tetrasubstituted ammonium salts as charge enhancing additives


An apparatus for producing embroidery data which are used by a sewing machine to move a sewing needle and a work cloth relative to each other so as to form stitches filling a desired original pattern on the cloth, the embroidery data including sets of coordinate data each representing a stitch position where the needle penetrates the cloth, the apparatus including a first device specifying a plurality of first defining points defining a first curve including at least one first adjustable curve segment in series, and a plurality of second defining points defining a second curve including at least one second adjustable curve segment in series and cooperating with the first curve to approximate an outline of the original pattern; a second device establishing an embroidery area by connecting between each of both ends of the first curve and a corresponding one of both ends of the second curve, and producing first sets of coordinate data representing a plurality of first stitch positions including at least one position along the first curve, and second sets of coordinate data representing a plurality of second stitch positions including at least one position along the second curve; and a third device producing the embroidery data by using the first and second sets of coordinate data, so that the sewing machine forms embroidery stitches by alternately connecting with a sewing thread between the first stitch positions and the second stitch positions according to the embroidery data.

1. Field of the Invention
The present invention relates to a method and apparatus for producing embroidery data used by a sewing machine.
2. Related Art Statement
It has conventionally been practiced to produce a batch of embroidery data for forming stitches filling an embroidery area, such that the embroidery data consist of a multiplicity of sets of stitch data, each set of stitch data being coordinate data representative of a stitch position where a sewing needle penetrates a work cloth. Therefore, the production of embroidery data needs operator's enormous labor to specify or input the coordinates of all the stitch positions, and in addition the embroidery data thus produced is bulky for memory means. In this background, it has been proposed to approximate an original pattern by a polygon, divide or reduce the polygon to simple polygonal blocks such as rectangles and triangles, and utilize, as embroidery data, sets of coordinate data indicative of the vertices of the polygonal blocks thus obtained. In the case where an original embroidery area at least partially outlined by a curve is embroidered, it has been practiced to approximate the curved outline or partial area by an "arcuate" block as shown in FIG. 19.
However, the conventionally used polygonal or arcuate blocks cannot sufficiently represent or approximate a curved portion of an original pattern. In order to increase the degree of representation or approximation of polygonal or arcuate blocks, it is required to divide the curved portion into more increased number of smaller blocks. This means that an increased amount of coordinate data is required for producing an embroidery with excellent external appearance. Thus, the problem that embroidery data is bulky has not been solved yet.

Embroidery data producing method and apparatus


Chimeric proteins are expressed, secreted or released by a bacterium to immunize against or treat a parasite, infectious disease or malignancy. The delivery vector may also be attenuated, non-pathogenic, low pathogenic, or a probiotic bacterium. The chimeric proteins include chimeras of, e.g., phage coat and/or colicin proteins, bacterial toxins and/or enzymes, autotransporter peptides, lytic peptides, multimerization domains, and/or membrane transducing (ferry) peptides. The active portion of the immunogenic chimeric proteins can include antigens against a wide range of parasites and infectious agents, cancers, Alzheimer's and Huntington's diseases, and have enhanced activity when secreted or released by the bacteria, and/or have direct anti-parasite or infectious agent activity. The activity of the secreted proteins is further increased by co-expression of a protease inhibitor that prevents degradation of the effector peptides. Addition of an antibody binding or antibody-degrading protein further prevents the premature elimination of the vector and enhances the immune response.

Citation or identification of any reference herein, or any section of this application shall not be construed as an admission that such reference is available as prior art to the present application. The disclosures of each of the publications cited herein, are hereby incorporated by reference in their entirety in this application, and shall be treated as if the entirety thereof forms a part of this application.
Worldwide, infectious diseases cause greater than one third of all deaths, more than any other group of related causes. Vaccines offer one of the greatest means of preventing infectious diseases. Unfortunately, many diseases remain without effective vaccines, or have treatments for which developing countries cannot afford. New vaccines, vaccine carriers, adjuvants, delivery methods and novel therapeutics are needed in order to meet the worldwide challenge of infectious diseases.
The use of live attenuated bacteria as carriers for delivering heterologous antigens from other infectious diseases is considered a promising methodology, yet remains without any products approved for clinical use more than 20 years after the concept was first developed (see Kotton and Hohmann 2004, Infection and Immunity 72: 5535-5547 and Roland et al., 2005, Current opinion in Molecular Therapeutics 7: 62-72 for reviews). Among the considerations for achieving therapeutic efficacy by such live attenuated bacterial vaccines delivering heterologous antigens is the secretion of sufficient quantities of the immunogenic antigen which is then capable of leading to a productive immune response. Similar hurdles also exist for therapeutic vectors secreting one or more anti-infective proteins or immunomodulatory cytokines such as IL-10 (Steidler and Rottiers, 2006, "Annals of the New York Academy of Sciences 1072:176-186; Neirynck and Steidler 2006, Biotechnology & Genetic Engineering Reviews 22: 253-66; Steidler 2005," Expert opinion on drug delivery 2:737-46).
Most infectious disease agents gain entrance to the host through a mucosal surface, and therefore the first line of defense is the mucosal immune system. In fact, protection against many microorganisms better correlates with local rather than systemic immune responses (Galan et al., 1986, Infection & Immunity 54:202-206; Galan and Timoney 1985, Infection & Immunity 47:623-628). Live, replicating agents are known to better stimulate mucosal immunity partly because they tend to persist longer (Ganguly and Waldman, Prog Allergy 27:1-68 (1980).
Avirulent strains of Salmonella endowed with the ability to express cloned genes from other pathogens have been used to stimulate a generalized mucosal immune response against the recombinant virulence antigens (Doggett and Curtiss 1992, Adv Exp Med Biol 327:165-173; Curtiss et al., 1988, in Virulence Mechanisms of Bacterial Pathogenesis, R. Roth, Ed., pp. 311-328; Curtiss et al., 1990, Res Microbiol 141:797-805). However, the use of replicating bacteria to stimulate mucosal immune responses has been hampered by secretion of antigens that effectively induce secretory immunity. For a review of secretion fusion systems, see Ni and Chen 2009 (Biotechnol. Lett 31: 1661-1670).
Use of secreted proteins in live bacterial vectors has been demonstrated by several authors. Holland et al. (U.S. Pat. No. 5,143,830, expressly incorporated in its entirety herein by reference) have illustrated the use of fusions with the C-terminal portion of the hemolysin A (hlyA) gene, a member of they type I secretion system. When co-expressed in the presence of the hemolysin protein secretion channel (hlyBD) and a functional TolC, heterologous fusions are readily secreted from the bacteria. The type I secretion system that has been utilized most widely, and although it is currently considered the best system available, is thought to have limitations for antigen delivery by attenuated bacteria (Hahn and Specht, 2003, FEMS Immunology and Medical Microbiology, 37: 87-98). Those limitations include the amount of protein secreted and the ability of the protein fused to it to interfere with secretion. Improvements of the type I secretion system have been demonstrated by Sugamata and Shiba (2005 Applied and Environmental Microbiology 71: 656-662) using a modified hlyB, and by Gupta and Lee (2008 Biotechnology and Bioengineering, 101: 967-974) by addition of rare codons to the hlyA gene. Fusion to the gene ClyA (Galen et al., 2004, Infection and Immunity, 72: 7096-7106 and Type III secretion proteins have also been used. Other heterologous protein secretion systems include the use of the autotransporter family (see Jose, 2006 Applied Microbiol. Biotechnol. 69: 607-614 and Rutherford and Mourez 2006 Microbial Cell Factories 5: 22). For example, Veiga et al. (2003 Journal of Bacteriology 185: 5585-5590 and Klauser et al., 1990 EMBO Journal 9: 1991-1999) demonstrated hybrid proteins containing the β-autotransporter domain of the immunoglogulin A (IgA) protease of Nisseria gonorrhea. Fusions to flagellar proteins have also been shown to be immunogenic. The antigen, a peptide, usually of 15 to 36 amino acids in length, is inserted into the central, hypervariable region of the FliC gene such as that from Salmonella muenchen (Verma et al. 1995 Vaccine 13: 235-24; Wu et al., 1989 Proc. Natl. Acad. Sci. USA 86: 4726-4730; Cuadro et al., 2004 Infect. Immun. 72: 2810-2816; Newton et al., 1995, Res. Microbiol. 146: 203-216). Antigenic peptides are selected by various methods, including epitope mapping (Joys and Schodel 1991. Infect. Immune. 59: 3330-3332; Hioe et al., 1990 J. Virol. 64: 6246-6251; Kaverin et al. 2002, J. Gen. Virol. 83: 2497-2505; Hulse et al. 2004, J. Virol. 78: 9954-9964; Kaverin et al. 2007, J. Virol. 81:12911-12917), T-cell epitope determination (Walden, 1996, Current Opinion in Immunology 8: 68-74) and computer programs such as Predict7 (Carmenes et al. 1989 Biochem. Biophys. Res. Comm 159: 687-693) Pepitope (Mayrose et al., 2007. Bioinformatics 23: 3244-3246). Multihybrid FliC insertions of up to 302 amino acids have also been prepared and shown to be antigenic (Tanskanen et al. 2000, Appl. Env. Microbiol. 66: 4152-4156). Trimerization of antigens has been achieved using the T4 fibritin foldon trimerization sequence (Wei et al. 2008 J. Virology 82: 6200-6208) and VASP tetramerization domains (Kühnel et al., 2004 PNAS 101: 17027-17032). As noted above, each of the foregoing and following references is expressly incorporated by reference in its entirety herein.
Other technologies employing bacteria have also been explored as methods to create vaccines. U.S. Pat. No. 6,177,083 by Lubitz, expressly incorporated herein by reference, describes the use of membrane disruptive proteins or bacteriophages to create non-living, non-replicative "bacterial ghosts"; bacterial fragments that contain the desired antigen. However, bacterial ghosts are generally less immunogenic than live bacteria, and multiple doses with larger quantities are required since they do not replicate. To date, none have entered clinical trials.
In addition to combating parasitic or infectious diseases using vaccines, anti-infectious agents are used to directly to treat infections. For example, Ivermenctin (22, 23-dihydroavermectin B1a+22, 23-dihydroavermectin B1b), marketed under the brand name Mectizan, is currently being used to help eliminate river blindness (onchocerciasis) in the Americas and stop transmission of lymphatic filariasis and onchocerciasis around the world. However, the number of effective anti-parasitic therapies is few, and many would-be anti-parasitic compounds are ultimately found to be unsuitable for use in humans and other mammals or birds because they are not effective at reaching the site of infection. Even though bacteria such as Salmonella, Enterococcus and Escherichia are known to be able to infect nematodes such as Caenorhabdus elegans, they have not been suggested as anti-parasitic vectors capable of delivering anti-infective proteins nor has the desirability of such a system been recognized. New methods to deliver anti-parasitic drugs directly to the site of infection would greatly enhance their effectiveness.
Although bacteria have been used as vaccine for infectious diseases, it has not been recognized that they could be modified to serve as direct anti-infective agents with the ability to deliver anti-infective proteins. Furthermore, the usefulness of bacterial vaccine vectors has remained to be fulfilled, perhaps in part because the inability to prevent degradation of effector proteins following secretion. Copious secretion and sustained activity of antigens and/or anti-parasitic peptides through their stabilization by protease inhibitors expressed by attenuated bacteria that result in effective vaccines or therapeutic vectors has not previously been achieved.

Immunization and/or treatment of parasites and infectious agents by live bacteria


An elongate flexible vacuum tube including an inner porous liner of intertwined flexible fibers of nylon or the like connectable between a vacuum source and the interior of a flexible vacuum bag covering a part formed of uncured thermosetting resin, or of superposed sections or laminae with thermosetting adhesive therebetween, under an overlying porous breather pad of intertwined fibers. An end of the liner can be positioned in intimate contact with the breather pad to form a vacuum path therewith so that a vacuum can be pulled on the part from a vacuum source, through the porous liner and breather pad, while it is being cured in an autoclave.

1. Field of the Invention
This invention relates to the manufacture of parts, such as, for example, aircraft, boat and automobile panels, embodying resins and/or adhesive materials.
2. Description of the Prior Art
The curing and/or bonding of shaped composite parts comprising fibers such as graphite or Kevlar fibers impregnated with thermosetting resins or of thin metallic sections or laminas or metallic and resinous sections with thermosetting adhesive therebetween, is recognized as an effective method of manufacturing lightweight, high strength panels.
In curing composite parts, the materials are generally placed on a shaped tool or mold in an uncured and somewhat pliant state. A relatively high degree of temperature and pressure is then applied thereto to remove air, moisture and volatiles from the material during the forming and curing operation.
In bonding thin sections of metal and a composite material together, a thermosetting adhesive is applied between the sections and they are likewise placed on a shaped tool and subjected to a high degree of temperature and pressure to remove the volatile, etc., therefrom during the forming and curing operation.
The bonding of shaped parts is generally accomplished by covering the materials to be bonded with a porous breather mat or pad, mounting a vacuum bag thereover and sealing the edges of the bag to the tool. The assembly is then placed in an autoclave and heated and pressurized therein while vacuum is applied to the vacuum bag to withdraw the air, volatiles, etc. from the part being treated.
The breather pad is preferably formed of intertwined flexible fibers to permit the application of a uniform pressure on the part to force it against the tool in order for it to accurately conform to the contour of the tool and insure the uniform evacuation of gaseous components therefrom. Such breather pads can, for example, be formed of nylon material in the manner disclosed and claimed in my copending patent application, Ser. No. 07/894,949, filed Jun. 8, 1992 now U.S. Pat. No. 5,261,993.
Heretofore, vacuum has generally been applied to the interior of the aforesaid vacuum bag by a suitable vacuum pump or the like connected through a hose to a vacuum valve or connector attached to the bag and communicating through an opening in the bag with its interior. Although these valves are generally satisfactory, any resinous material sucked through such a valve, quick disconnect, and hose to the pump tends to concentrate around the entrance to the valve and quick disconnect and to build up therein, as well as on the inside of the remainder of the vacuum system, thus reducing the amount of vacuum and eventually closing off the passages in the valve, connector, hose, etc., requiring replacement of these parts. It can even clog the vacuum pump in some cases to disable the whole system.
Also, as pressure is applied to the vacuum bag, the vacuum valve is pressed down against the breather pad, which results in a very small and undesirable evacuation path. Moreover, if there is insufficient room on the tool the valve is sometimes placed on top of the part which causes an undesired imprint thereof to be transferred to the surface of the part through the breather pad.
Accordingly, a principle object of the present invention is to provide means for overcoming the above-noted problems.
Another object of the invention is to provide vacuum-conveying means for evacuating a vacuum bag of the above type without any build-up of resins, etc., therein to reduce the amount of vacuum applied to the bag or even disable the system.
Still another object of the invention is to provide an evacuating path which will prevent resins, etc., from being transferred from the part being cured to the vacuum system.
A further object of the invention is to provide vacuum-conveying means which can be repetitively used for a large number of successive curing operations.
Yet another object of the invention is to provide vacuum-conveying means which is inexpensive and readily replaceable.
According to the invention, vacuum-conveying means is provided comprising a flexible tube of any desired length having an inner tubular liner of porous fibrous material which is mounted at one end of the tube for direct contact with said porous breather pad. A vacuum connector is mounted in contact with the liner at the opposite end of the tube and is connected to a suitable vacuum source. As vacuum is applied, the various gases, along with any resins, removed from a part being cured are passed through the breather pad and liner, enabling such resins to be deposited throughout the length of the liner. The liner preferably has a relatively large cross sectional area and can thus accumulate a considerable amount of resin, or other effluent, along its length without adverse effect on the evacuation process.
The vacuum connector is removably supported by a frame part to prevent strain from being applied to the vacuum tube which might otherwise distort the vacuum bag or pull the tube from its connection to the vacuum bag. It also permits quick and ready removal thereof from the connected vacuum bag after each curing operation.

Apparatus for forming shaped parts of thermosetting resins or other materials


A polymer composition and method for reducing the permeability of gases through molded polymeric containers and films by incorporating into the polymer from which the container or film is formed an effective amount of a barrier-enhancing additive, such as monoesters of hydroxybenzoic acid and hydroxynaphthoic acid.

The present invention is a polymer composition and method for improving the gas barrier performance of polymeric containers and films, and particularly containers for food and beverages which are molded from thermoplastic polyester polymers. More particularly, the invention is a polymer composition and method for reducing the permeability of gases through molded polymeric containers, sheets and films by incorporating into the polymer from which the container, sheet or film is formed an effective amount of a barrier-enhancing additive of the type described herein.
The addition of small amounts of molecular additives to a base polymer can result in antiplasticization of the polymer whereby the modulus of the polymer increases below its glass transition temperature and its barrier to gas permeability can improve. For example, Robeson describes the use of phenyl-2-naphthyl amine in polysulfone [Robeson, L. M.; Faucher, J. A., J. Polym. Sci., Part B 7, 35-40 (1969)] and various polychlorinated aromatic molecules in polycarbonate and in polyvinyl chloride [Robeson, L. M., Polym. Eng. Sci. 9, 277-81 (1969)]. Maeda and Paul [Maeda, Y.; Paul, D. R., J Polym. Sci., Part B: Polym. Phys. 25, 981-1003 (1987)] disclose the use of tricresyl phosphate in polyphenylene oxide to lower the sorption of carbon dioxide (and therefore its permeability). However, the need exists to improve the gas barrier performance of polymer resins of the type currently used for molded containers for food and beverages, and, in particular, poly(ethylene) terephthalate (PET) thermoplastic polyester polymers used for producing injection stretch blow molded bottles for packaging water, carbonated soft drinks and beer. Additives selected from 4-hydroxybenzoates and related molecules of the type described herein have not been suggested.
The present invention and the inventive features described herein reside in the discovery of certain barrier-enhancing additives for thermoplastic polymers. The invention is a polymer composition that contains one or more of the additives and a method for reducing gas permeability of shaped polymeric articles produced from such a composition, such articles being generally selected from containers, sheets and films.
The method comprises incorporating into the polymer an effective amount of a barrier-enhancing additive, or a mixture of barrier-enhancing additives, selected from the group consisting of:
(a) monoesters of hydroxybenzoic acid and hydroxynaphthoic acid of the formula (A)
wherein R is C1-C8 alkyl, benzyl, phenyl or naphthyl; Ar is substituted or unsubstituted phenylene or naphthalene; or formula (AA) where M is a cation such as, but not limited to, sodium, ammonium, tetraalkyl ammonium, potassium, calcium, magnesium or zinc;
(b) diesters of hydroxybenzoic acid of the formula (B)
wherein Ar is as defined above, and R1 is C1-C8 alkyl, (CH2CH2O)kCH2CH2 where k is 1 or more, benzyl, phenyl or naphthyl; or formula (BB) where M is as defined above.
(c) monoamides of hydroxybenzoic acid and hydroxynaphthoic acid of the formula (C)
wherein R and Ar are as defined above; or formula (CC) where M is as defined above.
(d) diamides of hydroxybenzoic acid of the formula (D)
wherein Ar is as defined above, and R2 is C1-C8 alkyl, (CH2CH2O)kCH2CH2 where k is 1 or more, benzyl, phenyl or naphthyl; or formula (DD) where M is as defined above.
(e) ester-amides of hydroxybenzoic acid of the formula (E)
where Ar is as defined above and R3 is C1-C8 alkyl, C1-C8 dialkyl, (CH2CH2O)kCH2CH2 where k is 1 or greater, benzyl, phenyl or naphthyl, or formula (EE) where M is as defined above. As used herein, an effective amount, i.e., the preferred range of barrier enhancing additive, is from 0.1% by wt. to 20% by wt. of the base polymer comprising the polymeric article.
Polymeric articles, and particularly extruded film or injection stretch blow molded polyester (e.g., PET) bottles, which contain one or more of the barrier-enhancing additives described herein, exhibit substantially reduced oxygen and carbon dioxide permeability values when measured according to ASTM D3985 and water vapor permeability values when measured according to ASTM F1249 in comparison to corresponding polymeric articles which contained no barrier-enhancing additives.
The present invention resides in the discovery that oxygen, water vapor and carbon dioxide (CO2) permeability values for shaped polymeric containers and films can be substantially reduced by incorporating into the base polymer from which the articles are formed from about 0.1% by wt. up to about 20% by wt. of a barrier-enhancing additive of the type defined herein.
A uniform physical blend, or mixture, is prepared comprising the base polymer and one or more barrier-enhancing additives in the desired concentrations. As used herein with reference to the invention, the term xe2x80x9ccompositionxe2x80x9d is intended to mean a physical blend or mixture. Water-sensitive base polymers, such as, for example, polyesters should preferably be thoroughly dried by heating under air or nitrogen flow or vacuum as known to those experienced in the art. The mixture is then heated and extruded or molded at a sufficiently high temperature to melt the base polymer and provide for sufficient mixing of the additive or mixture of additives within the base polymer matrix. By way of example using PET, such melt temperature ranges from about 255xc2x0 C. to 300xc2x0 C. The composition thus produced comprises the barrier-enhancing additive (or mixture of such additives) substantially in its (their) original molecular form; that is, only small amounts of barrier-enhancing additive have been observed to react with the base polymer via trans-esterification or other reaction mechanism typical of the functional groups present. It is preferred to prepare and extrude or mold the polymer composition under conditions of relatively low temperature and processing residence time which thereby minimizes the opportunity for the barrier-enhancing additives to react with the base polymer. Best performance in terms of desirable mechanical properties of polymeric containers and films produced according to the invention is achieved when no more than about 10% of the gas barrier-enhancing additive has reacted with the base polymer. As a consequence of any reaction of a gas barrier-enhancing additive within the scope of the invention with a base polymer, the molecular weight of the starting base polymer may decrease.
The gas barrier-enhancing additives found to be most suitable for carrying out the invention are selected from the group consisting of:
(a) monoesters of hydroxybenzoic acid and hydroxynaphthoic acid of the formula (A)
wherein R is C1-C8 alkyl, benzyl, phenyl or naphthyl; Ar is substituted or unsubstituted phenylene or naphthylene; or formula (AA) where M is a cation such as, but not limited to, sodium, ammonium, tetraalkyl ammonium, potassium, calcium, magnesium or zinc;
(b) diesters of hydroxybenzoic acid of the formula (B)
wherein Ar is as defined above, and R1 is C1-C8 alkyl, (CH2CH2O)kCH2CH2 where k is 1 or more, benzyl, phenyl or naphthyl; or formula (BB) where M is as defined above.
(c) monoamides of hydroxybenzoic acid and hydroxynaphthoic acid of the formula (C)
wherein R and Ar are as defined above; or formula (CC) where M is as defined above.
(d) diamides of hydroxybenzoic acid of the formula (D)
wherein Ar is as defined above, and R2 is C1-C8 alkyl, (CH2CH2O)kCH2CH2 where k is 1 or more, benzyl, phenyl or naphthyl; or formula (DD) where M is as defined above.
(e) ester-amides of hydroxybenzoic acid of the formula (E)
where Ar is as defined above and R3 is C1-C8 alkyl, C1-C8 dialkyl, (CH2CH2O)kCH2CH2, where k is 1 or greater, benzyl, phenyl or naphthyl, or formula (EE) where M is as defined above.
The above-defined barrier-enhancing additives can be obtained from commercial suppliers or they can be synthesized using established procedures.
Base polymers most suitable for use in practicing the invention comprise thermoplastic homopolymers, copolymers (both block and random), and blends of such thermoplastic polymers. Most suitable are polyester homopolymers and copolymers. Among suitable polyester base polymers are those polymers which contain structural units derived from one or more organic diacids (or their corresponding esters) selected from the group consisting of terephthalic acid, isophthalic acid, naphthalene dicarboxylic acids, hydroxybenzoic acids, hydroxynaphthoic acids, cyclohexane dicarboxylic acids, succinic acid, glutaric acid, adipic acid, sebacic acid, 1,12-dodecane dioic acid and the derivatives thereof, such as, for example, the dimethyl, diethyl, or dipropyl esters or acid chlorides of the dicarboxylic acids and one or more diols selected from ethylene glycol, 1,3-propane diol, nathphalene glycol, 1,2-propanediol, 1,2-, 1,3-, and 1,4-cyclohexane dimethanol, diethylene glycol, hydroquinone, 1,3-butane diol, 1,5-pentane diol, 1,6-hexane diol, triethylene glycol, resorcinol, and longer chain diols and polyols which are the reaction products of diols or polyols with alkylene oxides.
In a preferred embodiment of the invention the polyester base polymer is polyethylene terephthalate (PET), which includes PET polymer which has been modified with from about 2 mole % up to about 5 mole % of isophthalate units. Such modified PET is known as xe2x80x9cbottle gradexe2x80x9d resin and is available commercially as Melinar(copyright) Laser+polyethylene terephthalate brand resin (E. I. du Pont de Nemours and Company, Wilmington, Del.). As used hereinafter in illustrating the invention, the term PET will refer to commercially available xe2x80x9cbottle gradexe2x80x9d polyester resin.
Preparation of Film and Container Samples
Film samples are indicative of the improved gas barrier properties obtainable from the invention. Such film samples were generated from physical blends of a base polymer and a selected additive from among those described herein, and the samples were either compression molded or extrusion cast using a co-rotating twin screw extruder with a slit die, typically having a 0.38 mm gap, a quench roll, and a vacuum port on the front barrel section, with barrel, adapter, and die temperatures set at 240xc2x0 C. to 275xc2x0 C. depending on the polymer composition being used. Melt temperatures were measured with a thermocouple, and, for samples prepared using a twin screw extruder, melt temperatures were typically about 15xc2x0 C. to 20xc2x0 C. above the set temperature. In a few instances as noted, a transfer line, in which static mixers were installed within the line in place of a compounding screw, was used along with a slit die. Films were typically 0.05 to 0.25 mm thick. The thick films were subsequently stretched biaxially simultaneously to 3.5xc3x97 by 3.5xc3x97 using a Long stretcher at 90xc2x0 C., 9000%/minute unless otherwise noted.
For fabricating bottles, 26 g preforms were injection molded using a Nissei ASB 50 single stage injection stretch blow molding machine with barrel temperatures set at about 265xc2x0 C. and with a total cycle time of about 30 seconds. The preforms were immediately blown into 500 mL round-bottomed bottles with a blow time of 5 seconds. All other pressure, time and temperature set-points were typical for commercially available PET bottle resin.
Tensile bars xe2x85x9xe2x80x3 thick were molded using a 6 oz. injection molding machine with the following machine set-up: barrel temp: 255xc2x0 C., mold temp: 20xc2x0 C./20xc2x0 C., cycle time: 20 sec/20 sec, injection pressure: 5.5 MPa, RAM speed: fast, screw speed: 60 rpm, and back pressure: 345 kPa.
Analytical Procedures
NMR Spectrometry
Samples for 1H NMR were dissolved in tetrachloroethane-d2 at 130xc2x0 C. Spectra were acquired at 120xc2x0 C. at 500 MHz.
Thermal Analysis
Differential Scanning Calorimetric data were acquired at 2xc2x0/min on a TA Instruments calorimeter.
Permeability
Oxygen permeability values (OPV) were measured for each sample according to ASTM procedure D3985 at 30xc2x0 C., 50% RH on an Ox-Tran 1000 instrument from Modem Controls, Inc. Carbon dioxide permeability was measured at 25xc2x0 C. and 0% RH on a Permatran CIV instrument, also from Modern Controls, Inc. Water vapor permeability was measured at 37-38xc2x0 C., 100% RH on a Permatran-W600 instrument, also from Modem Controls, according to ASTM procedure F1249.
Intrinsic Viscosity
Intrinsic viscosity values were determined from 0.4 wt % solution of polymers or polymer blends in a 1:1 (by weight) mixture of methylene chloride and trifluoroacetic acid at 20xc2x0 C.

Method and composition for improving gas barrier properties of polymeric containers and films


A valve device has a movement element, which is cylindrical at least in sections, and a guide element, which has a guide recess for guiding the movement element and is pressed into a valve housing. The guide element comprises a radially inner ring-like section and a radially outer ring-like section. The guide recess is arranged in the inner ring-like section. On its outer circumference, the outer ring-like section has a number of contact sections which are arranged distributed uniformly over the circumference and by means of which the outer ring-like section is pressed into the valve housing. The inner ring-like section is connected to the outer ring-like section via an identical number of connecting sections, which are arranged distributed uniformly in the circumferential direction, wherein, as viewed in the circumferential direction, the connecting sections are offset radially by an angle of 180 DEG/N in relation to the contact sections.

The disclosure relates to a valve device as described herein.
Magnetic switching valves are known commercially. The lifting movement of an armature is often transmitted therein to a valve member by means of a valve needle which can carry out the actual valve function at a sealing seat. The valve needle is generally guided on portions of a cylindrical outer face ("guiding faces"). Those guiding faces preferably have a hard surface so that the wear remains low over the service-life. This is particularly advantageous if those switching valves switch a brake fluid, a petroleum fuel or a diesel fuel and are flowed through thereby because those media have a low level of lubrication property. Therefore, it is advantageous to bring about the guiding of the needle by means of a separate component which is, for example, hardened. A cost-effective possibility of assembling that guiding component is to press the separate guiding component into a housing portion of the switching valve.
Patent publications from this technical field are, for example, DE 10 2008 043 237 A1, DE 10 2007 034 038 A1, DE 10 2007 028 960 A1, DE 10 2005 022 661 A1, DE 10 2004 061 798, DE 2004 016 554 A1, DE 103 27 411 A1, DE 198 34 121 A1, EP 1 701 031 A1, EP 1 471 248 A1, EP 1 296 061 A2 and DE 198 33 461 A1.

Valve device having a movement element which is cylindrical at least in sections


An airfoil (44) formed of a plurality of pre-fired structural CMC panels (46, 48, 50, 52). Each panel is formed to have an open shape having opposed ends (54) that are free to move during the drying, curing and/or firing of the CMC material in order to minimize interlaminar stresses caused by anisotropic sintering shrinkage. The panels are at least partially pre-shrunk prior to being joined together to form the desired structure, such as an airfoil (42) for a gas turbine engine. The panels may be joined together using a backing member (30), using flanged ends (54) and a clamp (56), and/or with a bond material (36), for example.

Ceramic materials are often used in high temperature applications such as the hot combustion gas path components of a gas turbine engine. Monolithic ceramic materials generally exhibit higher operating temperature limits than do metals, however they lack the toughness and tensile load carrying capabilities required for most structural applications. Ceramic matrix composite (CMC) materials are known to provide a combination of high temperature capability, strength and toughness.
FIG. 1 is a cross-sectional view of a prior art component, specifically a stationary airfoil or vane 10 for a gas turbine engine that is formed using ceramic materials. Vane 10 includes a layer of a very high temperature ceramic insulating material 12 disposed over a CMC structural member 14, such as is described in U.S. Pat. No. 6,197,424, incorporated by reference herein in its entirety. The CMC structural member 14 defines a plurality of passages 16 for directing a flow of cooling air. Internal ribs or spars 18 are formed to stiffen the structure. One or both radial ends of the airfoil 10 may be supported in a platform (not illustrated) of a gas turbine engine. A layer of adhesive 20 may be used to join the insulating material 12 to the CMC structural member 14. The CMC structural member 14 may typically be formed by laying up a plurality of plies of material in stacked planes that are parallel to the exterior surface of the member 14. A predetermined number of such plies of material are used to achieve a desired thickness dimension (perpendicular to the exterior surface) in the CMC structural member 14. The plies of material are thus wrapped around the leading edge portion 22 of the airfoil 10. Interlaminar stresses between adjacent plies can result from internal pressure in the cooling air passages 16, from thermal gradients across the CMC material, and from operating loads imposed on the airfoil 10.


A gasket for an electrodialysis cell assembly has a series flow path comprising a plurality of flow path sections joined by restrictor sections. Each of the flow path sections has a relatively wide width. The restrictor has less than the wide width so that a fluid flowing in the series flow path must increase its velocity as it flows through the restrictor. The result is that the fluid exiting the restrictor cause turbulence and agitation in the flow path sections. Manifold holes are located at opposite ends of the series flow path. A rigid port is positioned between each of the manifold holes and the ends of the series flow path. The successive cells of the assembly are defined by a pair of bipolar membranes with cation and/or anion exchange membranes between them. One of the gaskets is located between each two of the membranes.

This invention is suitable for use in electrodialysis ("ED") apparatus, with monopolar or bipolar ion-exchange membranes, especially suitable for producing concentrated acids, bases, and salts from dilute salt streams using a direct current driving force. Such apparatus uses ion-exchange membranes to separate, concentrate or transform ions that are usually present in aqueous solutions. The electrodialysis process is driven by a direct current force.
A number of publications and patents describe the membrane technology and the components used to construct the equipment used in the process. Of these publications, the ones judged most informative are:
U.S. Department of Energy Report on "Membrane Separation Systems--A research needs Assessment"; Chapter 8 on Electrodialysis, April 1990. DOE/ER/30133-HI PA1 "Handbook of Industrial Membrane Technology" Ed. by M. C. Porter. Chapter 8, Noyes Publications, 1990 PA1 "Electrodialysis Water Splitting Technology" by K. N. Mani; J. Membrane Sci., (1991), 58, 117-138 PA1 U.S. Pat. No. 5,240,579; 4,871,431; 4,863,596; 4,786,393; 4,737,260; 4,707,240; 4,569,747; 4,319,978; 4,303,493; 4,226,688, 4,172,779; 4,067,794; 3,993,517; 3,985,636; 3,878,086; and 3,679,059
An electrodialysis stack contains an anode and a cathode electrode at its two ends in order to provide an electrical input. Assembled therebetween is a series of membranes and separators (gaskets) secured together in face to face contact, like in a plate and frame filter press. In order to ensure long term reliability of the unit, the electrode chambers may be isolated hydraulically from the main processing unit through a use of a set of membranes and separate fluid circuits.
In a commercial plant, the main processing unit comprises a large number of unit cells, such as 50-250, for example. Each of these unit cells, comprises ion-exchange membranes and solution compartments. Each solution compartment is contained within a gasket, which may be made of a plastic material, such as polyethylene and which may be about 0.5-5 mm thick. These gaskets separate the membranes and provide an adequate sealing at the edges and at other areas, as may be necessary. The gaskets also provide a support for the adjacent membranes and enable a fluid flow into and out of the solution compartment.
Each of the membranes contains manifold holes cut out in the gaskets and "ports" extending from the manifold holes to the solutions compartments in the gasket. The manifold holes and membranes of an electrodialysis stack are aligned to form passage ways which enables the individual process stream to be delivered into and out of the individual solution compartments via the ports.
The unit cells in an electrodialysis stack may be made in a variety of types and sizes. For example, beginning at the anode end for the cell, a first type of unit cell comprises a cation membrane, a dilution or feed compartment, an anion membrane and a concentrate or product compartment. These components form a unit that is used in the desalination of brine solutions and in the recovery and production of salts. Such a unit is called a "standard electrodialysis concentration or desalting cell".
A second type of unit cell comprises a bipolar membrane, a feed or salt/acid compartment, wherein, a feed, such as a sodium salt or an organic acid, is acidified by the H.sup.+ ions generated by the bipolar membrane, a cation membrane that transports the sodium cation, and a base or product compartment where the sodium cation combines with the OH.sup.- ions generated by the bipolar membrane to form a sodium hydroxide (base). Such a unit cell is called a "two-compartment cation cell".
A third type of unit cell comprises a bipolar membrane, a product or acid compartment, an anion membrane and a feed or salt/base compartment. Such a unit is called a "two-compartment anion cell" and may be used to basify an ammonium salt solution in order to generate an acid product and an ammonia rich base solution.
Yet another type of unit cell comprises a feed or salt compartment, a cation membrane, a base compartment, a bipolar membrane, an acid compartment and an anion membrane. Such a unit is called a "three-compartment bipolar cell" and may be used to convert a salt, such as sodium chloride, into sodium hydroxide and hydrochloric acid.
Unit cells containing more than three membranes and three compartments are also known. Excluding electrode rinse loops, a two-compartment cell can handle two process streams while a three-compartment cell can handle three process streams and so on. When a direct current is passed through the central ("active") area of an electrodialysis stack, the ions contained in a solution migrate in the direction of the current. The cations cross the cation membrane and move toward the cathode or negative electrode, while the anions move across the anion membrane and toward the anode or positive electrode. If a bipolar membrane is deployed in the electrodialysis stack with the cation side facing the cathode, the direct current input accelerates the dissociation of water at the membrane's interface. As a result hydrogen (H.sup.+) and hydroxyl (OH.sup.-) ions are concentrated on the cathode and anode sides, respectively. Depending on the cell configuration and the process deployed, the end result is a concentration of a salt from a dilute stream or a depleted salt stream or is a conversion of a salt into its acid and base components.
While the performances of the specific ion-exchange membranes that are deployed and the adequate pretreatment of the feed stream, (e.g. pH adjustment, filtration etc.) are important to a successful operation of electrodialysis process, an equally important aspect is the flow and distribution of the fluids inside the gasket or separator.
Commercially the two major electrodialysis designs in common use are called "sheet flow" and "tortuous flow".
Examples of sheet flow separators are sold by Asahi Glass, Tokuyama Soda, and by Aqualytics, a division of Graver Water. The active area is usually 50-85% or more of the overall gasket area in order to maximize the membrane utilization. This active area is open to both fluid and electrical flow. The membrane itself is supported by a non-woven "mesh" material having approximately the same overall thickness as the gasket. The mesh also distributes the fluid in the active area. To further ensure a uniform fluid distribution across the length or width of the active area, a multiplicity of feed manifolds and ports are employed. In these conventional stacks, the pressure drop and membrane strength considerations dictate that the superficial linear velocity of the liquid be kept low, typically in the order of 5-10 cm/sec.
Experience indicates that the distribution of fluids over a large cross sectional area can, as in many commercial stacks employing the "sheet flow" design, be a problem when the process is operated at high electrical current densities (>50 mA/cm.sup.2) or at lower stream conductivities (<20 mS/cm). Other problems occur with membrane swelling or wrinkling, particularly when there are even trace amounts of precipitable substances in the feed stream. Further, the conventional use of multiple manifolds and ports aligned in a stack of gaskets increases the intercompartment leakage.
Shunt and stray electrical current problems result in process inefficiencies which can cause an overheating or meltdowns of gaskets. This problem usually limits to about 100 the number of unit cells that can be safely deployed in series, without requiring some kind of electrical current interruption structure located between electrodes in a commercial stack operating with highly conductive solutions or at high current densities.
The overall flow rate requirements are high, due to the need to maintain the requisite linear velocity over large cross-sectional flow area. This need, in turn, requires the use of larger pumps and recirculation tanks. If mechanically weak (e.g. 20-45 psi burst strength), the prior art membranes are poorly supported in the large active area. They are easily damaged or broken over a long term operation due to the pressure variations in the feed streams.
Ionics Inc. uses electrodialysis stacks having a tortuous flow electrodialysis design employing gaskets having a long liquid flow path. Individually, the Ionics flow channels are quite narrow, (typically 1-1.5cm). They make several 180.degree. turns between the entrance and exit ports. The Ionics ports themselves are simply slots formed in the gaskets. The membranes are mechanically stiff structures in order to prevent their collapse into and the resultant blockage of the ports.
To overcome polarization problems associated with the low conductivity feeds, a higher linear flow velocity is used, typically 30-50 cm/sec. There are high pressure drops in such stacks (as high as 3-6 bars vs.0.5-2 bar for the sheet flow stacks). Consequently, the conventional membranes for the tortuous flow stack s have been thick and mechanically sturdy. Typically, they have a high electrical resistance leading to high power consumption.
Tortuous flow stacks are suitable for desalination applications which operate at a low electrical current density (0.1-10 mA/cm.sup.2). For chemical production applications, such as a conversion of sodium chloride to caustic soda and hydrochloric acid in a three compartment cell which operates at high current density (30-200 mA/ cm.sup.2) ,the amount of heat generated and the resulting temperature increases are unacceptable when using tortuous flow stacks unless the active areas of the stack are small. This limit on the active area size, in turn, requires the use of a large number of stacks in a commercial plant, with an attendant high cost. The stacks are also prone to intercompartment leakage because the membranes swell and spall.


The present invention provides a two-dimensional material nanosheets with a large area and a controllable thickness and a general preparation method therefor. As an intralayer heat transfer coefficient of a two-dimensional material is much higher than an interlayer heat transfer coefficient thereof, the two-dimensional material is uniformly heated and sublimated layer by layer by controlling the energy of the laser pulses, a thinning thickness is controlled by adjusting the action time of the laser pulses, and finally, a two-dimensional material film with a controllable thickness is obtained. At the same time, a sample displacement stage moving freely in a two-dimensional plane space can realize preparation of the two-dimensional material film with a large area. Compared with traditional methods, the present invention can control a sample thickness of the two-dimensional material film, has a high generality, and is suitable for all kinds two-dimensional materials.

In recent years, two-dimensional materials represented by graphene have made a huge splash in materials science, and two-dimensional structures thereof have brought special performances to the materials. Two-dimensional material is a material bound by an interlayer van der Waals force, and therefore can be thinned, even to a single layer, by simple mechanical exfoliation. The two-dimensional materials exhibit different optical, electrical and magnetic properties due to difference in number of layers thereof. For example, single-layer graphene is a zero-bandgap semiconductor, while bilayer graphene is a metal; half-integer quantum Hall effect can be observed in single-layer graphene, but cannot be observed in bilayer graphene; MoS2 layers with different thicknesses can be used to adjust detection of light with different wavelengths, wherein single-layer MoS2 and bilayer MoS2 are proved to be effective for detecting green light, while three-layer MoS2 is suitable for detecting red light; PtS2 has the properties of a semiconductor when the thickness is within 5 layers, and has the properties of a metal when the thickness is more than 5 layers; therefore, materials can be modified by using two-dimensional materials with different thicknesses, which provides a basis for broader research and application and is expected to lead an industrial revolution based on material innovation.
However, preparation technology of the two-dimensional materials with different thicknesses still faces a lot of challenges. First, although most two-dimensional layered materials can be obtained by mechanical exfoliation method, the thickness cannot be controlled by this method and transverse size of a sample is relatively small. Large-area graphene and some transition metal chalcogenides can be prepared by other methods such as liquid phase exfoliation or chemical vapor deposition, but the thickness of the sample is still difficult to control, and these methods are not universal, which requires further optimization in the preparation of new two-dimensional materials. Therefore, in order to realize the wide application of the two-dimensional materials, preparation with a controllable thickness is a premise, which involves professional equipment for the preparation of the two-dimensional materials and preparation technology developed on the basis of the professional equipment.
Existing preparation methods for two-dimensional layered material films have the disadvantages of difficulty in material thickness controlling, small area and poor applicability, which seriously restrict the practical application thereof. In order to avoid the disadvantages of the existing two-dimensional material preparation technology, the present invention provides a general preparation method for a two-dimensional layered material film with a large area and a controllable thickness, which is to use high-energy nanosecond laser pulses to heat and sublimate a layered sample protected by a polymethyl methacrylate (PMMA) coating, and by adjust laser power, pulse time and pulse number to change the temperature applied to a material. When the applied temperature reaches the sublimation temperature of the material by intralayer conduction, thinning effect of one layer can be achieved; when a top layer of material is sublimated, a second layer of material begins to be sublimated; thinning thickness of the material is controlled by adjusting the pulse time and the pulse number. This method can quickly realize the large-scale preparation of a two-dimensional layered material film with a controllable thickness, and has the advantages of simplified operation and high production efficiency.
Intralayer heat transfer coefficient of a two-dimensional material is: 0.1-2 W/cm·K. Interlayer heat transfer coefficient of the two-dimensional material is: 0.01-0.2 W/cm·K. For the same two-dimensional material, the intralayer heat transfer coefficient is about 10 times higher than the interlayer heat transfer coefficient. Therefore, heat generated on the sample when irradiated by a laser device tends to be released from intralayer to interlayer, an energy gradient generated makes the sample sublimated layer by layer, thus the number of layers is reduced. For the same two-dimensional material, the thickness of each layer is same, so the thickness of material is reduced as the number of layers is reduced.

Two-dimensional material nanosheets with large area and controllable thickness and general preparation method therefor


Closed air space devices and methods of use for full body bio hazard type suits that eliminates condensation and fogging from forming on the face masks and the window visors of the suit. The devices and methods have a sealed closed air space that can be formed from flexible see-through plastic in a cone shape that can be sealed between the mask and the visor. The closed air space can be pre-sealed to the visor/outer wall of the suit and have a second end fitted with an elastic type band that allows the wearer to attach and detach the closed space by wrapping the band about their face mask. Other embodiments use flat see-through plastic sheets, and sheets that attach about the neck of the user to form the closed air spaces between the face mask and the window visor of the suit.

Emergency workers such as firefighters, and the like, and workers that handle biological and hazardous materials, often require the use of full body suits for their work, such as type Level A and Level B Suits. A Level A Suit is a suit worn when the highest level of skin, respiratory, and eye protection against chemicals is needed. The suit consists of a totally encapsulating, vapor-protective ensemble worn with a self-contained breathing apparatus (SCBA) when the environment in which tasks have to be performed presents immediate danger to life and health (IDLH) hazard at both a respiratory and skin contact and impairs a worker's ability to escape. The level B Suit is worn when the highest level of respiratory protection is required but a lesser level of skin protection is needed. The suit consists of a chemical liquid splash protective suit worn with an SCBA when the environment presents an IDLH inhalation hazard, but does not present a skin contact hazard nor does it impair a worker's ability to escape. These full body suits have been known to have condensation problems that seriously affect their usefulness.
A common problem with these suits is that the masks worn by the workers and/or the visors on the suit become fogged within approximately five minutes of use. The build up of condensation on the visors and/or masks reduces the worker's visibility so as to not allow the worker to effectively perform the precision tasks required in their jobs. This lack of visibility causes which reduces the operating time of the workers and can become fatal when working in environments having smoke, hazardous chemicals and the like. Additionally, it is a known fact that firefighters and emergency type workers can only stay in their suits for approximately twenty minutes, due to the air supply and the heat conditions from typical fires that can lead to dehydration. That means that every second is valuable for the limited amount of time that the firefighter and emergency worker can wear their suits. Thus, the decreased visibility and high degree of body heat will shorten the working time in the suit and will have drastic effects on the effectiveness of the person wearing the suit.
The typical technique of handling the condensation problem is for the firefighters to carry towels which are used to wipe clean the mask and the visor of the suit. Based on the condensation problem, the firefighter would typically have to clean their masks and/or visors every five minutes while they are fighting a fire. However, to use the towels, the firefighter would have to open their suits exposing their bodies to the dangerous environment which they are in. Alternatively, the firefighter would have to leave the fire to clean their masks and/or visors every seven minutes. Furthermore, the towel solution is also problematic because the user must spend time to wipe the condensation away, which reduces the time spent on their work tasks. Also, the user must carry the towel which also takes up valuable space and one of the valuable hands of the user which takes away the effectiveness of the worker performing their work.
Various types of modified body suits that include fluid chilled systems, pre-chilled or forced air systems, passive cooling systems, ice or gel or cool packs, evaporative cooling, and environment cooling systems have been developed to deal with condensation problems, but come with their own problems. Many of these added on components can be expensive, require electricity and batteries to operate. Additionally, many of these added on systems have moving parts that require regular maintenance. Mobility with these modified suits is often limited because of having separate components, such as the reservoir and pump are which are separate from the suit garment. These modified suits also can add substantial weight to the body which can tire and slow down the effectiveness of the user. Further, these add on systems, and components take up precious space which further can limit the length of operation of users wearing the modified suits. Still furthermore, these added on component systems are often uncomfortable to wear, require additional undergarments, and can be cold and damp to the wearer of the modified suits further adding to the discomfort of their use.
Anti-fogging solutions such as products such as RainEx® and the like, can be used on the masks and/or visors. However, these solutions only delay when condensation occurs. For example, the RainEx® product has been tested to delay the start of condensation which causes the fogging effect only up to approximately seven minutes, which means that the masks and/or visors still have to be wiped clean with towels after seven minutes instead of after five minutes.
Thus, the need exists for solutions to the above problems.

University of Central Florida Research Foundation, Inc.


A cleaning device removes residual toner particles from a cleaning target, such as a photoconductor, which has a moving surface. The cleaning device includes a cleaning brush, a power circuit, and a cleaning member. The cleaning brush includes a brush rotation shaft, and the power circuit applies a first voltage of a first polarity to the brush rotation shaft. The cleaning member applies a second voltage of the first polarity to the cleaning brush. If the first polarity is negative, the cleaning member electrostatically removes toner particles having a positive polarity from the cleaning target. Then, the cleaning brush is triboelectrically charged to a second polarity, which is opposite to the first polarity, by contacting the cleaning target. Accordingly, the cleaning brush also removes residual toner particles having a negative polarity. Thus, the cleaning device removes both positively and negatively charged toner particles to clean the cleaning target.

1. Field of the Invention
Exemplary aspects of the present invention generally relate to a cleaning device employed in an image forming apparatus such as a copying machine, a facsimile machine, and a printer; a process cartridge; and an image forming apparatus that includes the cleaning device and the process cartridge.
2. Discussion of the Background
A related-art image forming apparatus, such as a copying machine, a facsimile machine, a printer, or a multifunction printer having two or more of copying, printing, scanning, and facsimile functions, forms a toner image on a recording medium (e.g., a sheet) according to image data using an electrophotographic method. In such a method, for example, a charger charges a surface of an image bearing member (e.g., a photoconductor). An optical device emits a light beam onto the charged surface of the photoconductor to form an electrostatic latent image on the photoconductor according to the image data. The electrostatic latent image is developed with a developer (e.g., a toner) to form a toner image on the photoconductor. A transfer device transfers the toner image formed on the photoconductor onto a sheet. A fixing device applies heat and pressure to the sheet bearing the toner image to fix the toner image onto the sheet. The sheet bearing the fixed toner image is then discharged from the image forming apparatus.
The related-art image forming apparatus further includes a cleaning device for removing toner particles remaining on a surface of the photoconductor after transfer has been performed. The cleaning device includes a cleaning blade formed of rubber, which contacts the photoconductor to remove the toner particles remaining on the surface of the photoconductor. When the cleaning blade does not accurately contact the photoconductor, the toner particles on the surface of the photoconductor pass through the cleaning blade and remain thereon, degrading cleaning performance. To solve such a problem, the cleaning blade is pressed against the photoconductor with a high linear pressure. However, the high linear pressure causes curling-up of the cleaning blade. As a result, a part of the toner particles are not removed by the cleaning blade and remain on the surface of the photoconductor in a linear or band-like shape. Thus, higher cleaning performance may not be stably obtained. Moreover, over an extended period of time, the surface of the photoconductor is further worn away, shortening a product life of the photoconductor.
To meet demand for higher quality images, toner particles having a smaller particle diameter and a spherical shape have been developed in recent years. Furthermore, to meet demand for reduction in manufacturing costs of toner and improvement in transfer rate, image forming apparatuses using toner having particles of a spherical shape manufactured using a polymerization method have become widely commercialized over those using pulverized toner having particles of an irregular shape. At the same time, however, it is known that the cleaning blade cannot reliably remove the toner particles having a smaller particle diameter and a spherical shape from the surface of the photoconductor as compared to pulverized toner particles.
One example of a cleaning device uses an electrostatic brush cleaning method to reliably remove the toner particles having a smaller particle diameter and a spherical shape from the surface of the photoconductor, and to prevent the surface of the photoconductor from being abraded by mechanical rubbing by the cleaning blade. In the electrostatic brush cleaning method, a cleaning brush is provided in contact with the surface of the photoconductor, and furthermore, a collecting roller serving as a cleaning member is provided in contact with the cleaning brush to remove the toner particles from the cleaning brush. A voltage is applied to the cleaning brush, or to both of the cleaning brush and the collecting roller. The toner particles charged to a polarity opposite to that of the voltage applied to the cleaning brush are electrostatically adhered to a brush string of the cleaning brush, so that the toner particles are removed from the surface of the photoconductor. Therefore, the electrostatic brush cleaning method can provide reliable and improved cleaning performance for the toner particles having a smaller particle diameter and a spherical shape.
Generally, a voltage with a polarity opposite to that of toner particles after development has been performed is applied to a transfer member so as to transfer the toner particles on the surface of the photoconductor onto a sheet. Therefore, a charge with a polarity opposite to that of the charge injected into the toner particles during development is injected into the toner particles on the surface of the photoconductor during transfer. Consequently, the more weakly charged toner particles are charged to the polarity opposite to that of the toner particles after development has been performed due to the charge injection during transfer described above. Therefore, a part of the toner particles remaining on the surface of the photoconductor after transfer has been performed have a polarity identical to that of the toner particles after development has been performed, and the other part of the toner particles have a polarity opposite to that of the toner particles after development has been performed. In other words, both toner particles charged to the polarity opposite to that of the voltage applied to the cleaning brush and toner particles charged to the polarity identical to that of the voltage applied to the cleaning brush remain on the surface of the photoconductor after transfer has been performed. Consequently, the toner particles on the surface of the photoconductor that are charged to the polarity identical to that of the voltage applied to the cleaning brush are not electrostatically adhered to the cleaning brush and pass through the cleaning brush, resulting in poor cleaning performance.

This patent is subject to a terminal disclaimer.

Cleaning device, image forming apparatus, and process cartridge


A quadrature phase signal generator comprises a relative delay unit, a phase detector, a first amplifier and a loop filter. The relative delay unit delays differential input signals and generates four delayed signals. The phase detector generates quadrature four phase output signals, a first voltage signal and a second voltage signal according to the four delayed signals. A difference of the first and the second voltage signals indicates a phase error of the quadrature four phase output signals. The first amplifier amplifies the voltage difference of the first and the second voltage signals. The loop filter filters the amplified voltage difference and generates a tuning voltage signal. The loop filter is further communicatively coupled to the relative delay unit. The relative delay unit adjusts a delay of the quadrature four phase delayed signals according to the tuning voltage signal.

A local oscillator is an electronic oscillator used to generate a signal. An In-phase and Quadrature (I, Q) signals can be generated using a voltage controlled oscillator (VCO) or a Delay Locked Loop (DLL).
It is desirable to have a quadrature signal generator that reduces or eliminates mismatch of phase detectors and generates signals with desired duty cycle.

Signal generator, electronic system comprising the signal generator and method of generating signals