The invention concerns a process for the production of paraxylene and an apparatus suitable for said process. The process separates the overhead from a xylenes re-run into a xylene-rich stream and a xylene-lean stream. The xylene-lean stream is isomerized under conditions such that the xylenes are in the liquid phase.

An equilibrium mixture of xylenes contains roughly 24% para-xylene (PX), 56% meta-xylene (MX), and 20% ortho-xylene (OX). PX is relatively high value as compared with MX and OX, and it is desirable to isomerize OX and/or MX to PX. Vapor phase and liquid phase processes for isomerizing PX-lean streams to equilibrium for subsequent PX recovery are described in numerous patents. It is an active area of research.
A typical paraxylene production process involves the so-called xylene loop. An example is illustrated in FIG. 1, which is a simplified flow diagram showing three major operations that occur in the xylene loop. There are many vaporization and condensation steps.
Liquid feed, typically a C8+ aromatic feedstream which has previously been processed by known methods to remove C7− species (particularly benzene and toluene), is fed by conduit 1 to xylenes re-run 3, an apparatus per se well known in the art. The xylenes re-run (or more simply a fractionation column) vaporizes the feed and separates the C8 aromatics into an overhead mixture 5 of xylenes (OX, MX, and PX) and ethylbenzene (EB), and a bottom product 61 comprising C9+ aromatics. The overhead mixture typically has a composition of about 40-50% metaxylene (MX), 15-25% PX, 15-25% OX, and 10-20% EB. Unless otherwise noted herein, percentages are % weight. The overhead is then condensed in condenser 7, an apparatus also per se well-known in the art, and becomes the feed for the PX recovery unit 15, via conduit 9 and 13, a portion of the condensed overhead may be returned to re-run 3 as reflux via conduits 9 and 11.
The PX recovery unit 15 may employ crystallization technology, adsorption technology, or extraction technology, each per se well known in the art. These technologies separate PX from its isomers and are capable of producing high purity PX up to 99.9%, which is taken from unit 15 via conduit 17. Shown in FIG. 1 is the case where unit 15 is an adsorptive separation unit, such as a Parex™ Unit, in which case typically the extract 17, which comprises a desorbent, such as PDEB (paradiethylbenzene), needs to be separated, such as by distillation, from the desired extract PX in distillation column 19, which generates an overhead 23 that is condensed in condenser 25 to yield a liquid stream 27, which is a high purity PX stream. This stream 27 may be taken off via conduit 31 and optionally a portion may be returned to column 19 as reflux via conduit 29. The desorbent is returned to the PX recovery system 15 via conduit 21. Raffinate from the recovery system 15, comprising MX, OX, EB, and some PX, is removed via conduit 65 and sent to unit 37, discussed below. Note: a portion of raffinate in 65 may be recovered and marketed as low-value solvent xylene.
The raffinate 65, which comprises mainly MX, OX, EB, and desorbent is sent to fractionation column 37, generating overhead 33 and bottoms 63. Overhead 33 contains MX and OX, which is condensed in condenser 32 and sent via conduit 35 and then 41 to isomerization unit 43, discussed in more detail below. A portion may be returned to fractionator 37 via conduit 35 and then 39 as reflux. The desorbent in the bottoms product is returned to 15.
A stream consisting essentially of MX and OX and EB is sent to isomerization unit 43, an apparatus per se known in the art, to isomerize the MX and OX and optionally EB to PX. Conventionally unit 43 is a vapor phase isomerization unit. Conventionally there are one or more heat exchangers or furnaces associated with the system shown in FIG. 1 between the PX recovery unit 15 and the isomerization unit that are not shown for convenience of view. Likewise, hydrogen separators and hydrogen compressors are also not shown for convenience of view. These and other features, such as valves and the like, would be apparent to one of ordinary skill in the art in possession of the present invention.
The product of the isomerization unit 43 is sent via conduit 51 to the C7− distillation tower 53, which separates the product of isomerization into a bottom stream 59 comprising equilibrium xylenes and the overhead 47, comprising C7− aromatics, e.g., benzene and toluene. The overhead product is condensed in condenser 45 and then the distribution of liquid product via conduit 49 may be apportioned as desired between conduit 57 and conduit 55, the former of which may be disposed of in numerous ways which would be well-known per se in the art, and the latter conduit returning C7− aromatics as reflux to tower 53. The bottoms product 59 of distillation tower 53 is then sent to xylenes re-run 3, either merging with feed 1 as shown in the figure, or it may be introduced by a separate inlet (not shown).
Note that as used herein the term "raffinate" is used to mean the portion recovered from the PX recovery unit 15, whether the technology used is adsorptive separation, crystallization, or membrane, and then is sent to the isomerization unit 43, conventionally a vapor phase isomerization unit, which uses technology also per se well-known. The xylene isomerization unit (whether vapor phase or liquid phase) accomplishes two major things. It isomerizes the lower valued MX and OX to higher value PX and it also turns EB into benzene/toluene and light gases (so-called "EB destruction") or optionally, isomerize EB to xylenes. EB destruction or EB isomerization prevents the build up of EB within the xylenes loop. Products from the isomerization unit are distilled to separate C7− compounds (particularly toluene and benzene) prior to being recycled back to the xylene re-run.
Particularly relevant patents include U.S. Pat. No. 6,689,929 U.S. Pat. No. 6,878,855; WO 2005/075389; and WO 2005/075390.
Recently the present inventor, along with others, has described with particularity processes involving the use, at least partially, of liquid phase isomerization in U.S. Provisional Application Ser. Nos. 12/612,007 and 61/326,445
The present inventor has now discovered a process for PX production which in embodiments provides for a significant reduction in energy consumption by eliminating excessive vaporization and unnecessary recycling.

Paraxylene production process and apparatus


An array of display elements (e.g., pixels) in a display device (e.g., a spatial light modulator) may be digitally driven using pulse width modulated waveforms. Pulse width modulated waveforms may be locally generated to controllably drive each pixel in display systems with digital storage. A pixel drive circuit having a waveform generator may receive first digital data indicative of an optical output from an associated first display element. Moreover, second digital data indicative of a common reference with respect to a second display element may also be received at the first display element for comparison purposes. As a result, in one embodiment, a pulse width modulated waveform that includes only a single transition separating a first pulse interval and a second pulse interval may be generated based on a pixel value and a global count value instead of relying upon adding up multiple non-overlapping waveforms to drive a pixel.

The present invention relates generally to electro-optical displays, and more particularly, to drive circuits with available digital storage for generating modulated waveforms, driving display elements of a display device.
An array of display elements (e.g., pixels) in a display device may be driven using drive signals, such as modulated waveforms. In doing so, each modulated waveform may individually drive a different pixel of the display device. There are many ways to generate these drive signals.
One approach involves using pulse width modulation (PWM) which is a well-known technique, having a host of applications including in display systems. By generating pulse width modulated waveforms, pixels with digital storage, such as in liquid crystal displays (LCDs) may be driven. For instance, a spatial light modulator (SLM) uses an electric field to modulate the orientation of a liquid crystal (LC) material. By the selective modulation of the LC material, an electronic display of an image may be produced on a screen, as the orientation of the LC material affects the intensity of light going through the LC material. Sandwiching of the LC material between an electrode and a transparent top plate, for example, may enable the modulation of the optical properties of the LC material. When the voltage applied across the electrode and the transparent top plate is changed, the LC material may produce different levels of output intensity, altering the image produced on the screen.
However, allowing a duty cycle of a drive signal to vary as a non-linear function of a pixel value within a refresh period may result in multiple "ON" pulses. Several existing PWM-based schemes for driving pixels rely on adding up non-overlapping waveforms to build a PWM waveform, causing undesirable multiple edges in the PWM waveform. Generation of such multiple-edged PWM waveform may fail to appropriately control the LC material. Unfortunately, while displaying an image, this lack of drive control may result in an inadequate control over optical outputs from pixels being driven. That is, this technique may produce undesired, multiple, intermediate sub-levels of intensity while transitioning between different desired levels of intensity.
Thus, there is a need for better ways to controllably drive display elements in display systems with available digital storage.

Generating pulse width modulated waveforms to digitally drive pixels


The present invention relates to nucleic acid molecules containing poly (dA:dT) regions which are stabilized in E. coli, methods of propagating such nucleic acid molecules in E. coli, methods of obtaining RNA, peptides or proteins using such nucleic acid molecules and to RNA which is obtained from such nucleic acid molecules and its use. In particular, the poly (dA:dT) regions contain at least one disruption by a sequence not encoding a sequence solely composed of A residues.

The use of RNA offers an attractive alternative to DNA in order to circumvent the potential safety risks connected with the therapeutic use of DNA. In vitro-transcribed RNA (IVT-RNA) is of particular interest in therapeutic approaches. The advantages of a therapeutic use of RNA include transient expression and a non-transforming character. RNA does not need to enter the nucleus in order to be expressed and moreover cannot integrate into the host genome, thereby eliminating the risk of oncogenesis. When used for vaccination, injection of RNA can induce both cellular and humoral immune responses in vivo. However, the use of RNA for clinical applications is greatly restricted especially by the short half life of RNA.
IVT vectors may be used in a standardized manner as template for in vitro transcription. Such IVT vectors may have the following structure: a 5′ RNA polymerase promoter enabling RNA transcription, followed by a gene of interest which is flanked either 3′ and/or 5′ by untranslated regions (UTR), and a 3′ polyadenyl cassette containing A nucleotides. Prior to in vitro transcription, the circular plasmid is linearized downstream of the polyadenyl cassette by type II restriction enzymes (recognition sequence corresponds to cleavage site). The polyadenyl cassette thus corresponds to the later poly(A) sequence in the transcript.
The 3′ poly(A) sequence of RNA is important for nuclear export, RNA stability and translational efficiency of eukaryotic messenger RNA (mRNA). The 3′ poly(A) sequence is shortened over time and if short enough, the RNA is degraded enzymatically.
We have previously demonstrated that a 3′ poly(A) sequence with a length of 120 nucleotides (A120) has a predominant effect on RNA stability and translational efficiency and thus, is beneficial for all-over RNA efficacy.
However, it has been observed that the DNA sequence encoding the 3′ poly(A) sequence (3′ polyadenyl cassette), i.e. a stretch of consecutive dA:dT base pairs, is subjected to shortening in some bacterial subclones, when propagated in E. coli. Accordingly, before producing the plasmid DNA as the starting material for in vitro transcription a large number of bacterial clones has to be tested, e.g., by determining the length of the 3′ polyadenyl cassette by suitable restriction analysis, to obtain a single clone with a 3′ polyadenyl cassette of the correct length encoding a 3′ poly(A) sequence of the correct length.
It was the object of the present invention to find a 3′ polyadenyl cassette which shows constant propagation with the coding plasmid DNA in E. coli and which encodes a 3′ poly(A) sequence maintaining the effects with respect to supporting RNA stability and translational efficiency.
This object is achieved according to the invention by the subject matter of the claims.
According to the invention, it was found that a disruption of the 3′ polyadenyl cassette (poly(dA:dT) region) by a 10 nucleotide random sequence, with an equal distribution of the 4 nucleotides (linker), has only minor influence on functionality of the encoded RNA but increases the stability of the 3′ polyadenyl cassette in E. coli. Further, neither the sequence nor the position of the linker within the 3′ poly(A) sequence resulted in a reduction of translational efficiency and stability of the in vitro transcribed RNA (IVT RNA).
For stability testing of the IVT vector region encoding the 3′ poly(A) sequence, the SIINFEKL peptide (SEQ ID NO: 1) was cloned upstream of the poly(dA:dT) region. This construct showed a poly(dA:dT) instability (i.e. percentage of clones upon propagation with shortened poly(dA:dT)) of 50-60%. Detailed analysis, using the described restriction analysis method identified the region at position 30-50 as being particular sensitive to shortening of the poly(dA:dT) stretch. Introduction of a 10 nucleotide random sequence in this sensitive region led to an increase of the poly(dA:dT) stability. Constructs with 30 or 40 adenosine nucleotides, followed by the linker sequence and another 70 or 60 adenosines (A30L70 and A40L60) respectively, resulted in an poly(dA:dT) instability of only 3-4% in E. coli. Results were confirmed by testing the constructs in several different E. coli strains.
Functionality of IVT RNA encoded by DNA carrying the stabilized poly(dA:dT)-tails was tested in different assays. Electroporation of the IVT RNA in somatic cell lines but also in immune cells such as immature dendritic cells showed no difference in translational capacity compared to the A120 over a time period of 72 hours. Injection of luciferase encoding IVT RNA into mice confirmed an equal protein translation independent of the inserted type of the 3′ poly(A) sequence.
An impact on the immunological response of the different 3′ poly(A) sequences was analyzed by comparison of the amount of antigen-specific CD8+ T-cells upon injection of SIINFEKL (SEQ ID NO: 1) IVT RNA. The experiments revealed no difference between the A120 and its stabilized versions A30L70 and A40L60.
Taken together, we show that the insertion of a 10 nucleotide random sequence between position 30 and 50 of a poly(dA:dT) region results in a more than 10-fold sequence stabilization in E. coli. The corresponding modified 3′ poly(A) sequence of the RNA transcribed from the template DNA has the same functionality, i.e. stability and translational efficiency in vivo and in vitro as the classical A120. Additionally the immunological response is not altered by the use of a modified poly(A) sequence.

Stabilization of poly(A) sequence encoding DNA sequences

TRON—Translationale Onkologie an der Universitätsmedizin der Johannes Gutenberg-Universität Mainz gGmbH


A device and method for heating exhaust gas from the combustion of fossil fuel upstream of an emissions control device, especially a diesel particulate filter. A conduit receives an exhaust gas flow, and is in fluid communication with the emissions control device for supplying exhaust gas thereto. A flow straightener is disposed in the conduit, and a portion of the exhaust gas flows through the flow straightener. An igniter is disposed in the conduit between the flow straightener and the emissions control device for igniting fuel supplied thereto to produce a flame to heat the exhaust gas flow.

The present application relates to a device and method for heating exhaust gas from the combustion of fossil fuel upstream of an emissions control device.
It is an object of the present application to provide an improved device and method for heating exhaust gas to achieve combustion or conversion of matter that has collected in a particulate filter or other emissions control device disposed in an exhaust system of an internal combustion engine or other fossil fuel burning device, without the need for a separate combustion or conversion chamber.

Device and method for heating exhaust gas


An anode-supported flat-tubular solid oxide fuel cell stack includes a plurality of fuel cells and a plurality of connector plates. Each of the fuel cells includes a supported tube having semi-cylinder parts and plate parts, a connector coated on an upper plate of the supported tube as a way to be positioned at the center of the upper plate, an electrolyte layer partly coated on an external surface of the supported tube except for a portion of the supported tube coming into contact with the connector, and an air electrode coated on an external surface of the electrolyte layer. Each of the connector plates includes a lower connector plate, middle connector plates, and an upper connector plate. A plurality of gas channels are formed on the middle and lower connector plates. The anode-supported flat-tubular solid oxide fuel cell stack has a large capacity, improved power density, and reduced production costs.

1. Field of the Invention
The present invention pertains to a flat-tubular solid oxide fuel cell stack using an anode as a supported body and a method of fabricating the stack. More particularly, the present invention relates to an anode-supported flat-tubular solid oxide fuel cell stack, which includes an anode-supported tube having semi-cylinder parts and plate parts, thereby having a combined structure of a tube-type and a plate-type anode-supported body, and a method of fabricating the stack. The anode-supported flat-tubular solid oxide fuel cell stack is advantageous in that fuel cells constituting the stack are easily sealed, and have excellent resistance to heat stress and improved power density per unit area.
2. Description of the Related Art
A fuel cell is a highly efficiency clean generator, in which hydrogen contained in a hydrocarbon based material such as natural gas, coal gas, or methanol, is electrochemically reacted with oxygen contained in air to produce electric energy. It is classified into alkaline, phosphoric acid, molten carbonate, solid oxide, and polymer fuel cells.
Generally, the phosphoric acid fuel cell using a phosphoric acid electrolyte is referred to as a first generation fuel cell, in which hydrogen gas mostly containing hydrogen reformed from fossil fuel and oxygen contained in air are used as fuel, the high temperature molten carbonate fuel cell using molten carbonate as the electrolyte and operating at about 650° C. is referred to as a second generation fuel cell, and the solid oxide fuel cell (SOFC) operating at a relatively higher temperature and generating the most efficient electricity is referred to as a third generation fuel cell.
The third generation fuel cell, the solid oxide fuel cell, was developed after the phosphoric acid fuel cell (PAFC) and the molten carbonate fuel cell (MCFC), but it is expected that the solid oxide fuel cell will be rapidly commercialized in subsequent to PAFC and MCFC due to a rapid development of material technology. Additionally, the solid oxide fuel cell is operated at a high temperature ranging from 600 to 1000° C., and has advantages in that it is the most efficient of existing fuel cells, there are few pollutants discharged, a fuel reformer is not necessary, and a combined power generation is feasible.
The solid oxide fuel cell is generally classified into a tube type fuel cell, a plate type fuel cell, and a single body type fuel cell according to a shape of the solid oxide fuel cell. Of them, currently, the tube and plate type fuel cell are mostly studied, a technology of the tube type fuel cell is considered as the most advanced technology, and a study of the plate type fuel cell is more advanced than that of the single body type fuel cell. As for the tube type fuel cell, an air electrode support type fuel cell has been developed in the USA and Japan, and a self-supporting film type fuel cell comprising an electrolyte as a support and an anode-supported plate fuel cell has been developed as the plate type fuel cell.
The plate type solid oxide fuel cell has a higher current density than a disk type fuel cell, but has disadvantages in that a large-sized plate type fuel cell necessarily needed to produce a large capacity fuel cell is difficult to produce using the plate type solid oxide fuel cell due to several problems, such as sealing gas and thermal shock due to a difference of thermal equilibrium coefficient between constituents of the fuel cell.
In comparison with the plate type solid oxide fuel cell, the tube type solid oxide fuel cell is advantageous in that unit cells constituting the stack are easily sealed, resistance to heat stress and mechanical strength of the stack are high, thereby the tube type solid oxide fuel cell is considered to be an excellent technology by which the large-sized fuel cell can be most easily produced. However, the tube type solid oxide fuel cell has disadvantages in that the tube type solid oxide fuel cell has a lower power density per unit area than the plate type solid oxide fuel cell, and the production costs of the tube type solid oxide fuel cell are relatively high.
Meanwhile, a conventional tube type fuel cell is an air electrode-supported fuel cell using an air electrode as the support of the fuel cell, and the production costs of the fuel cell are increased because raw materials for the air electrode such as La and Mn, are very expensive, and production of LSM (LaSrMnO3) is difficult. In addition, the unit cell is low in mechanical strength and does not withstand impact because the air electrode acting as the support is made of ceramics while an anode is made of cermet consisting of metals and ceramics.
Furthermore, an electrolyte layer is coated on a surface of the air electrode-supported tube according to a process requiring high coating costs during fabrication of the conventional air electrode-supported tubular solid oxide fuel cell, thus the conventional air electrode-supported tubular solid oxide fuel cell is disadvantageous in terms of economic efficiency.
In other words, the air electrode is fragile because the air electrode is made of high-priced ceramics, such as La, which is used as the support in the conventional air electrode-supported tubular solid oxide fuel cell, the strength of the air electrode is reduced due to a chemical reaction, in the ceramic structure constituting the air electrode, at high temperatures, and the fuel cell price is increased because the electrolyte layer is formed on the surface of the air electrode by use of the very costly EVD process.
Furthermore, the electrolyte and the anode formed on a surface of the sintered air electrode-supported tube are co-sintered at high temperatures, and thus activity of the air electrode is reduced and an efficiency of the fuel cell is lowered.
To avoid the above disadvantages of the air electrode-supported solid oxide fuel cell, the anode-supported tubular solid oxide fuel cell using the anode as the support has been developed. The anode-supported tube used in the anode-supported tubular solid oxide fuel cell satisfies characteristics required by the electrode as well as acts as the support, and is advantageous in that co-sintering is feasible because reactivity is low between the support and the electrolyte layer, and a stable fuel cell stack can be fabricated due to high mechanical strength of the anode.
In addition, the anode-supported tube has sufficient pores therein, a fuel provision is not limited because a continuous pore distribution is formed in the anode-supported tube, and current flow is smooth due to high electric conductivity and production costs of the fuel cell are low.
When the anode-supported tubular solid oxide fuel cell is produced, the most important factor affecting productivity is a process of coating the electrolyte layer on the surface of the anode-supported tube.
In detail, a conductivity of YSZ, which is most widely used as the electrolyte in the solid oxide fuel cell, is about 10−1 S/cm at 1000° C., and the electrolyte layer should have a thickness of about 30 μm or lower and be very dense because the lower an operating temperature of the fuel cell is, the lower the conductivity is or the higher a resistance is.
The anode-supported tubular solid oxide fuel cell has a disadvantage in that the very thin and dense electrolyte layer should be formed on the surface of the porous anode-supported tube with a wide surface area. Therefore, recently, many studies have been initiated in order to develop a process of efficiently forming an excellent electrolyte layer.
When the electrolyte layer is formed by a physical and chemical vapor deposition process using a vacuum such as an EVD process or a plasma spray coating process, a dense and thin electrolyte layer can be formed, but equipment used to form the electrolyte layer is undesirably large and the reaction time is excessively long. In addition, the above processes are not suitable to produce the fuel cell in commercial quantities because a few of the unit cell are deposited by the electrolyte at one time.

Anode-supported flat-tubular solid oxide fuel cell stack and fabrication method of the same


A method of sterilizing a nanoparticle preparation at a high temperature is provided. A plurality of nanoparticles are purified to form the preparation, wherein the nanoparticles comprise at least a core and a shell and the shell comprises one or more ligand species attached to the core. The nanoparticle preparation is made by a purified nanoparticle composition, a carrier fluid and an excess of the one or more ligand species not attached to the core. The ligand species attached to the core and the excess ligand species added after purification are structurally identical. The nanoparticle preparation provided by the present invention may be used as contrast agents in medical imaging techniques such as X-ray and magnetic resonance imaging.

Nanoparticles, i.e. particles whose diameters are appropriately measured in nanometers, have been considered for a wide variety of end uses. Nanoparticles with appropriate imaging properties are typically based on transition metal oxides, and used as contrast agents for MR and/or X-ray imaging. Iron oxide nanoparticles are used in various therapeutic applications such as iron replacement therapy, magnetic particle imaging (MPI), drug targeting or gene delivery. Preparations containing nanoparticle compositions to be used for in vivo applications in human individuals are typically required to be purified and sterilized to prevent biological contamination, and are often desired to exhibit robust suspension stability in isotonic aqueous media.
Various methods for sterilization of nanoparticles exist, including UV irradiation, ethylene oxide treatment, formaldehyde treatment, sterile filtration, gamma irradiation, and autoclave sterilization. The autoclave sterilization for injectable contrast agents is considered to be one of the most reliable and inexpensive sterilization techniques.
Nanoparticle compositions in aqueous suspension are often subject to agglomeration and precipitation during the use of heat sterilization techniques, such as autoclaving. Efforts have been made to modify the surface properties of such nanoparticles to enhance the stability of aqueous suspensions of such nanoparticles by adding various surface modifiers. Use of a cloud point modifier to alter the temperature at which the nanoparticle aggregation occurs, enabling sterilization via autoclave, is an alternate approach. However, in some cases the cloud point modifiers are charged molecules and are different than the molecules which constitute the shell of the nanoparticles, and that introduces a risk of modifying the surface chemistry of the shell as well as the composition of the nanoparticles.
Methods for stabilizing a nanoparticle composition at elevated temperatures during autoclave sterilization without altering the nanoparticle surface chemistry are highly desirable. A preparation of the nanoparticle composition including improved stability, sterility, enhanced safety, and resistant to aggregation during heat sterilization, is advantageous for various applications.

Heat stable nanoparticle preparations and associated methods thereof


An image forming apparatus includes an image bearing member having an inorganic protective layer on a surface thereof, a cleaning blade having an inclined surface cut out at a corner portion on a side of the image bearing member, and a support portion that supports the cleaning blade so that the inclined surface is in contact with the image bearing member.

(i) Technical Field
The present invention relates to an image forming apparatus
(ii) Related Art
A cleaning blade has hitherto been used as a cleaner that removes residual toner and the like from a surface of an image bearing member, such as a photoconductor, in a copying machine, a printer, and a facsimile using an electrophotographic system.


A dual band detector includes a substrate, a composite barrier, a first absorber on the substrate and on a light incident side of the composite barrier, the first absorber for detecting first infrared light wavelengths, a second absorber on the composite barrier on a side opposite the light incident side, the second absorber for detecting second infrared light wavelengths, wherein a bandgap of the first absorber is larger than that of the second absorber, wherein the composite barrier includes a first secondary barrier, a primary barrier, and a second secondary barrier, wherein the first and second secondary barriers may have a lower bandgap energy than the primary barrier, wherein the first or the second secondary barrier may have a doping level and type different from that of the primary barrier, and wherein at least the primary barrier blocks majority carriers and allows minority carrier flow.

Dual band infrared (IR) detectors have been made using HgCdTe, quantum well infrared photo-detectors (QWIPs), and Type II superlattice (T2SL) materials. HgCdTe detectors have high performance, and although significant progress has been made in the development of HgCdTe detectors for MW (medium wavelength)/LW (long wavelength), LW1/LW2, and MW1/MW2 dual-band detectors, HgCdTe based infrared detectors have high cost and are difficult to scale to large detector arrays. QWIPs and InAs/GaSb T2SL detectors have the disadvantage of ˜10-100 times higher dark current as compared to HgCdTe. InAs/GaSb T2SL detectors have low minority carrier lifetimes which prevent FPA (focal plane array) operation at temperatures greater than 150 Kelvin.
Elevated temperature operation is essential for large format FPAs in order to minimize the size, weight and power footprint of an infrared (IR) imaging system.
In the prior art, InAsSb-based single-band/single color devices are described by Maimon and Wicks, Appl. Phys. Lett. 89 151109 (2006). Lee et al., "Subband transitions in dual-band n-B-n InAs/GaSb superlattice infrared photodetector identified by photoresponse spectra" in Appl. Phys. Lett 95, 102106 (2009) describes work by the University of New Mexico using T2SLs. The use of InAs/GaSb T2SL materials for dual band detectors is described by A. Khoshakhlagh et al., "Bias dependent dual band response from InAs/GaInSb type II strain layer superlattice detectors", APPLIED PHYSICS LETTERS 91, 263504 —2007. A method for producing a single-bump, dual-band detector for LWIR and VLWIR devices using pNp or n-p-B-p-n T2SL is described by Northwestern University in Applied Physics Letter 92, 111112 (2008).
What is needed is a dual band detector and method of making a dual band detector that is cost effective and that can be scaled up to greater than 4 k×4 k FPA formats, while providing HgCdTe-like performance. Also needed is a dual band detector that allows for elevated temperature operation, which is essential for large format FPAs in order to minimize the size, weight and power footprint of an infrared (IR) imaging system. The embodiments of the present disclosure answer these and other needs.

Dual band SWIR/MWIR and MWIR1/MWIR2 infrared detectors


A ring flash light diffusion device includes a first converter ring configured to connect to a camera lens and a diffuser adapter. The diffuser adapter can be connected to a first end of the first converter ring. It also includes a flash ring connected to the diffuser adapter at a position along the length of the diffuser adapter and a ring flash connected to the flash ring. It further includes a light diffuser connected to the diffuser adapter such that light emitted from the ring flash passes through the light diffuser.

In various circumstances, photographers are often plagued with inadequate or inappropriate light environments necessary to capture the subject of the photograph in an image of a desired visual quality. In particular, the lighting angle, focus, and direction all serve to impact the way a given subject will appear on a photograph.
Non-concentrated more diffuse lighting is often desirable help to obtain softer images with smoother edges. Diffuse lighting can be created by having a large light source far away from the subject and photographic camera or by having the light beams hit the subject from various angles. This effect can be achieved by passing a light through partially transparent or translucent materials such as diffusion gels, frosted glass screens, umbrellas, or cloth as well as by passing the light through a device with many reflective surfaces before it arrives at the subject being photographed. Such approaches are useful in a controlled indoor environment that is sufficiently large but are unwieldy and inconvenient to carry and relocate.
For circumstances where a photographer needs to have freedom of movement or positioned close to the subject being photographed, the approaches and devices described in the previous paragraph are inadequate. This inadequacy is particularly noticeable when it is desirable to capture an image of an object in motion or if the object is positioned very close to the camera as is the case for macro photography. Positioning a light source such as a ring flash on the end of a camera lens facilitates portability but provides a sharp bright light that creates dark deep undesirable shadows with high contrast in many circumstances.
Accordingly, there is a need for a light diffusion device that is easily portable and attachable to a camera. There likewise is a need in the field for a diffusion device that could accommodate a variety of light sources positioned on the camera lens such as variety of ring flash light sources to allow light to be diffused closer to the object being photographed.


The present invention provides methods for preparing, and compositions comprising, stabilized protein-polymer conjugates. More particularly, the present invention relates to the stabilization of individual subunits of multisubunit protein complexes by conjugation to polymers. Such conjugation acts to stabilize the individual subunit in its native conformation in liquid medium, which in turn acts to stabilize its biological activity.

The present invention relates to the conjugation of uncomplexed subunits of multisubunit protein complexes with polymers to stabilize their conformation. More specifically, the present invention describes a method of stabilizing these individual subunits via covalent conjugation to a natural or synthetic polymer. The present invention also relates to stabilized conjugates of cardiac troponin I and stabilized conjugates of cardiac troponin T, and methods for their preparation.
Proteins are composed of long chains of amino acids. The structure of proteins can be considered on four different levels. The primary structure refers to the specific order of amino acids in the polymer chain. The secondary structure refers to the interactions among and between the amino acids in the chain to form such structures as a helices and xcex2 pleated sheets. The tertiary structure refers to the three-dimensional structure of the protein, which is also referred to as a protein""s conformation. The quaternary structure refers to the spatial arrangement of individual polypeptides or xe2x80x9csubunitsxe2x80x9d of multisubunit proteins.
The native conformation of a protein is only marginally stable. Thus, many proteins which are removed from their native environment and purified undergo conformational changes which can cause a loss of biological activity, such as enzyme activity or antibody binding capacity. In particular, the individual (uncomplexed) subunits of multisubunit protein complexes may undergo dramatic conformational changes when separated from the other subunits of the complex and stored in a liquid medium.
It is often desirable to separate the individual subunits of a multisubunit protein complex, for example to study or exploit the biological activity of each individual subunit. However, this may not be possible if the individual subunits undergo conformational changes in their uncomplexed state that alter their biological activity. Accordingly, it is an object of the present invention to provide a method for stabilizing individual subunits of multisubunit protein complexes.
Troponin is an example of a multisubunit protein complex which consists of three individual subunits; troponin T, troponin C and troponin I. The troponin complex is involved in the calcium-sensitive switch that regulates the interaction of actin and myosin in striated muscles. Troponin T binds the troponin complex to tropomyosin, while troponin I is the inhibitory subunit of the complex. Whereas troponin C from skeletal muscle and cardiac muscle is identical, troponin I and T from these two sources exist as different isoforms, each having a different amino acid sequences and thus a unique structure. Thus, cardiac troponin I (cTnI) and cardiac troponin T (cTnT) are of particular interest as cardiospecific markers.
After myocardial infarction, cTnT levels increase and remain elevated for an extended period. However, it has been reported that in a variety of disease states, cTnT is also expressed in skeletal muscle, which contributes to a lack of cardiospecificity of this protein. Furthermore, uremia, a condition associated with cardiomyopathy, is associated with elevated cTnT. Thus, a lack of absolute cardiospecificity makes this marker less than optimal for use in the early diagnosis of acute myocardial infarction (AMI).
Cardiac TnI is also released after acute myocardial infarction. In contrast to cTnT, cTnI has never been found in a healthy population, which includes marathon runners, in people with skeletal disease, or in patients undergoing non-cardiac operations. Thus, cTnI is a more specific marker for the diagnosis of AMI than other serum proteins.
A variety of immunoassays have been developed that utilize antibodies that can distinguish between the three troponins, and also between their different isoforms. Monoclonal and polyclonal antibodies have been designed and used in immunoassays which can detect the cardiac-specific epitopes formed by the unique amino acid sequence of cTnI. See, for example PCT Patent Application No. WO 96/10076; European Patent No. 394,819 B1; and Adams et al., Circulation 88:101-106 (1993). Larue et al., (Clin. Chem. 39:972-979 (1993)) describe an immunoenzyme assay that is capable of detecting cTnI in the concentration range of 0.2 to 20 xcexcg/L in 30 minutes.
Immunoassays have also been described which are specific for TnT. See, for example, Katus, et al., Circulation, 83(3): 902-912 (1991). An immunoassay for TnT is also commercially available from Boehringer Mannheim Corp., Indianapolis, lnd.
Most immunoassays are designed to determine the concentration of a given marker in a patient""s serum by comparing immunoassay results with the patient""s serum to those obtained with control reagents of known concentration. One limitation in the development of immunoassays for the troponins involves the instability of the troponins in their uncomplexed state. Accordingly, there is a need for stabilized compositions of cTnI and cTnT that can be stored for extended periods of time, while retaining antibody binding capacity for use as control reagents in cTnI and cTnT immunoassays.
Stabilization of proteins via covalent conjugation to various polymers has been described. See, for example, U.S. Pat. No. 4,902,502; U.S. Pat. No. 5,468,478; U.S. Pat. No. 4,806,524; Katre et al., J. Immunol. 144:209-213 (1990); Abuchowski et al., J. Biol. Chem. 252:3582-3586 (1977). The properties conferred on the conjugated protein have been cited as increased in vivo half life, increased stability in solution, increased solubility, decreased susceptibility to proteases and decreased immunogenicity and antigenicity. For example, Nitecki et al. (U.S. Pat. No. 5,089,261) describe conjugating interleukin-2 to polyethylene glycol (PEG) to reduce immunogenicity.
In addition to stabilization of proteins via covalent conjugations to polymers, it has also been demonstrated that synthetic polymers are capable of providing a stabilizing effect via ionic interaction with proteins. For example, Marsh and Danielson (Analyst 120:1091-1096 (1995)) have described that the addition of PEG to an aqueous solutions of the multisubunit enzyme lactate dehydrogenase enhances the ability of the enzyme subunits to remain complexed.
The present invention relates to the finding that covalent conjugation of individual protein subunits of multisubunit proteins to polymers stabilizes the protein subunit, i.e. it maintains its native conformation in a liquid medium for a longer period of time than the equivalent unconjugated individual subunit. In a preferred embodiment, the present invention also relates to cTnI-polymer conjugates and cTnT-polymer conjugates which exhibit stabilized antibody binding capacity.
The present invention concerns stabilization of individual subunits of multisubunit protein complexes. Stabilization is accomplished by conjugating the individual subunits to a polymer. The stabilizing effect of conjugation allows the individual subunit to be stored in liquid medium for longer periods of time than an equivalent unconjugated or xe2x80x9cfreexe2x80x9d individual subunit. This greatly enhances the shelf life of the composition. In a preferred embodiment, the stabilized individual subunits are either cTnI or cTnT, which in their unconjugated form are highly unstable in liquid medium.
Polymers which are useful in the present invention can be naturally occurring or synthetic. Whereas certain synthetic polymers may be preferred for stabilization of free cTnI, as will be discussed below, natural polymers such as serum proteins are preferred for stabilization of cTnT. A particularly preferred class of synthetic polymer is PEG. Other suitable polymers include, but are not limited to polyalkylene glycols, polyoxyethylated polyols, polyvinylpyrrolidone, polyhydroxyethyl methacrylate, polyvinyl alcohols, and polyurethane.
The polymers which are useful in the present invention may vary in molecular weight, and must have a molecular weight which is sufficient to stabilize the individual subunit. This generally requires that the polymer have a molecular weight between 100 and 200,000, more preferably between 1,000 and 40,000, and most preferably between 2,500 and 10,000.
In order to conjugate the polymer to the individual protein subunit, it should be in an xe2x80x9cactivexe2x80x9d form, which means it must contain at least one reactive group capable of reacting with pendant groups on the protein to form a covalent linkage. When the polymer is PEG, a preferred active form is monomethoxy-PEG p-nitrophenyl carbonate.
The ratio of individual subunit to polymer in the conjugation reaction must be sufficient to stabilize the individual subunit. This generally requires that the polymer is provided in a molar concentration which is at least equivalent to the molar concentration of the individual subunit. Preferably, the polymer is provided in excess to ensure that a sufficient number of polymers are covalently attached to the individual subunits.
As an alternative to polymers, monomers (at least some of which are in an active form) can be used to form the protein-polymer conjugates of the present invention, which may polymerize during conjugation and may even attach directly to the protein subunit to afford the desired stability.
Another aspect of the present invention relates to compositions that consist of individual subunit-polymer conjugates in liquid medium. Suitable liquid media include water, aqueous solvents, serum, and mixtures thereof. Preferably, the liquid medium is mammalian serum, and more preferably, it is a mixture of human serum and bovine serum.
Other excipients, such as salts, buffers, proteins, polymers, carbohydrates, preservatives and reducing agents may also be added to the liquid medium.
A preferred embodiment of the present invention relates to stabilized conjugates of cTnI which are useful as control reagent compositions for immunoassays. Preferably, the cTnI conjugates are formed by conjugating a synthetic polymer, such as PEG, to the protein""s pendant amine groups. Because cTnI""s amine-containing lysine residues are not located in the cardiac-specific N-terminal portion of the protein, conjugation to PEG does not appreciably affect the ability of the cTnI to bind to cardiac-specific anti-cTnI antibodies.
In another embodiment, the present invention relates to a method of stabilizing individual subunits of multisubunit complexes by providing a solution of the individual subunit, adding a multifunctional crosslinking agent to activate the subunit, then simultaneously or subsequently adding a polymer to effect conjugation of the subunit to the polymer via the crosslinking agent. This method of stabilization is particularly preferred for conjugating serum proteins such as albumin to cTnT via glutaraldehyde, although it is also useful for other combinations of polymers and subunits as described herein, as well as with other multifinctional crosslinking agents.

Stabilized conjugates of uncomplexed subunits of multimeric proteins


An automatic valve includes a body configured to receive a piston axially therein, the piston being movable within the body between a first axial position in which the piston is configured to seal a valve opening when pneumatic pressure is applied to the piston and a second axial position in which the piston is configured to be withdrawn from the valve opening such that a fire suppression agent can enter the valve body through the valve opening, wherein the piston includes a channel longitudinally therethrough and a check valve positioned within the channel such that fluid can enter the check valve in a first longitudinal direction but not in a second longitudinal direction.

Fire suppression systems can either be manually or automatically activated. An example of an automatic system is a sprinkler system that is activated in response to detection of heat. The system is defined by a network of water pipes suspended from the ceiling of a building interspersed by a plurality of sprinkler heads. Each sprinkler head has a plug which is designed to burst or melt in response to application of heat. In this way, the system is effective at dousing a localised fire by way of activation of one, or a few sprinkler heads, or a larger fire through activation of multiple sprinkler heads.
Sprinkler systems typically use water as medium but water is not appropriate for fighting all types of fire. In the event of an electrical fire, application of water to the fire would potentially cause the fire to spread further. Furthermore, a sprinkler head is only activated following heating of the temperature sensitive plug by hot gases generated in the event of a fire. The hot gases would therefore have to be relatively localised in order to activate a sprinkler head thus potentially resulting in a delay between a fire taking hold and activation of the fire suppression system.
For applications such as electrical cabinets where it is desirable to directly target a point of ignition, systems that provide a direct path inside the electrical cabinet are known. Such systems use a heat sensitive tube which is designed to burst when it reaches a certain temperature. When the tube bursts, a fire suppression agent is dispersed directly from the point of burst onto the affected area of the electrical cabinet thus addressing the source of heat directly.
An example of a larger system where use of water might not be desirable is a pneumatic system that utilises a run of heat sensitive tube in the vicinity of equipment to be protected. The tubing is connected to a cylinder containing a fire suppression agent. When the tubing bursts, the system loses pressure and causes the cylinder to deliver a fire suppression agent to a plurality of valves that are not directly connected to the tubing. The pressure of the agent causes a cap to blow off each valve so that the fire suppression medium can be delivered to the source of the fire. Such systems are effective at fighting a fire in either a specific area or over a broader area but the response time can be diminished by the system first having to detect that pressure has been lost due to burst tubing before delivering a fire suppression agent through a separate tube or pipe network to the heat sensitive tubing.
Some pneumatic systems also provide a manual actuator which causes pneumatic pressure in the system to drop when actuated. A manual actuator provides means for an operator to quickly deploy the fire suppression system in the event of a fire rather than waiting for the temperature sensitive tubing to burst.
The present invention seeks to address the aforementioned problems.


A high pressure discharge lamp having a translucent sintered aluminum oxide discharge envelope is produced by a method that includes providing a ceramic end plug having an aperture for a current lead-in member in an end of the envelope, sintering the end plug to the envelope and passing the current lead-in member through the plug so as to extend into the envelope, forming a thin disc-shaped sealing member formed of magnesium oxide containing glass frit and having an aperture for the lead-in member on the outer surface of the plug, positioning a thin barrier member having an aperture for the lead-in member on and extending over the outer surface of the sealing member and heating the assembly so as to cause the sealing member to melt and form a glass bond between the lead-in member and the plug and the barrier member to melt and bond to the glass seal.

The instant invention relates to a high-pressure gas discharge lamp having an envelope enclosing a discharge space consisting of a translucent densely sintered aluminum oxide, at least one tubular current lead-in member secured in a gas-type manner in the envelope and an end plug having an aperture for the current lead-in member fused to a cylindrical part of the envelope.
In this lamp, the end plug is sealed to the current lead-in member by a glass seal.
Such a lamp generally contains an ionizable filling which frequently is a mixture of mercury, a rare gas and an alkali metal.
A lamp of this type is disclosed in Oomen U.S. Pat. No. 4,721,886. As shown in this patent, a gas-tight seal is provided between the end plug and the current lead-in member by a magnesium oxide containing glass sealing ceramic provided in a capillary space between the end plug and the current lead-in member.
While the magnesium oxide containing glass seal provides a satisfactory gas-tight construction, it has been found that when the lamp is operated so as to provide a high temperature where the current lead-in member enters through the end plug (for example 750.degree. C. produced during operation of a 150 W lamp), magnesium metal can evaporate from the seal. It is found that in such cases, the magnesium provides a coating on the inner surface of the envelope thereby significantly reducing the lumen output of the lamp. This phenomenon increases with time thereby diminishing the useful life of the lamp.

Method of manufacturing a high-pressure discharge lamp with end seal evaporation barrier


A power converter includes a PWM active rectifier and controller that minimize harmonic ripple currents on the DC link during an engine start mode (first stage) in which power is provided to an AC starter motor. The PWM active rectifier and controller also minimize harmonic currents on AC input lines during a second stage (active filter mode). The power converter also includes a PWM inverter and corresponding inverter controller that controls the performance of the AC starter motor during the first stage based on mode selection input received. The power converter system further includes pre-charge circuitry that charges a DC link capacitor located within the power converter system to a desired level prior to providing the power converter system with AC power.

The field of the invention relates generally to power converter systems for supplying power to a permanent magnet motor.
Commonly used in power generation systems, converters are devices that either convert alternating current (AC) power into direct current (DC) power (rectifier), or DC power to AC power (inverter). Whether a converter is being used as a rectifier or an inverter is dependent on the direction power is flowing through the converter. A typical power generation system may include a generator for producing AC power, an AC-DC converter (or rectifier), a DC link, a DC-AC converter (or inverter), and a load. The AC power generated by the generator is provided to the rectifier, which provides a rectified signal to the DC link. The inverter uses the rectified signal provided to the DC link to generate the desired AC power to the load. The quality of the AC power generated by the inverter is related to the quality of the DC power provided to the DC link. That is, by reducing fluctuations in current on the DC link, commonly referred to as ripple, the overall performance of the system is improved.
A typical method of reducing ripple on the DC link is to provide a capacitor or other filtering device between the rectifier and the inverter. The size of the capacitor or filter selected to reduce ripple is based on the amount of ripple that must be reduced. As ripple currents become large, the size of the capacitor becomes increasingly large and costly. Therefore, it would be desirable to design a system that reduces ripple current without the prohibitive cost of a large capacitor. Furthermore, the capacitor used to reduce ripple current between the rectifier and the inverter is often subject to high instantaneous currents at the initialization of the system, which adversely affects the performance of the capacitor. Therefore, it would also be desirable to design a system that would reduce exposure of the capacitor to high instantaneous currents.
The rectifiers discussed above can be generally classified as non-linear loads, since they may draw non-linear currents from the AC power source. A generator providing the AC power to the rectifier may also provide AC power to a number of other non-linear loads. Each of these non-linear loads contributes to generate harmonic currents on the AC input lines. A typical method of reducing the harmonic currents on the AC input lines is to include capacitive and inductive elements at the input of each non-linear load. Again, the size of the inductive and capacitive elements is related to the magnitude of the harmonics to be reduced. It would therefore be desirable to provide an economical solution to reducing the harmonic currents created on the AC input lines by non-linear loads.

Electric engine start system with active rectifier


Described herein are devices and methods for high throughput purification of particles. In some cases, methods and devices described herein can be used to remove erythrocytes and purify leukocytes and raise the quality of umbilical cord blood and other transplant grafts, thereby significantly improving patient outcomes.

There is a need for improved methods for high throughput isolation of particles using devices such as microfluidic devices. Also, there is a critical unmet need for rapid, efficient methods to deplete erythrocytes and recover leukocytes from G-CSF mobilized peripheral blood (PBSC), bone marrow (BM), and especially umbilical cord blood (UCB), prior to cryopreservation. Incomplete erythrocyte removal from transplant grafts can increase the risk of harmful side effects in hematopoietic stem cell transplants, while poor recovery of viable leukocytes and CD34+ cells can reduce engraftment success and limits the treatable patient population.

Methods and devices for high throughput purification


A radiographic imaging apparatus having a detector, a radiation source array, and a control processor is configurable to individually energize the radiation sources. A collimator having a number of apertures is movable to either a first or second position in a path of the radiation source array. In one position, the apertures are aligned with a first subset of the radiation sources. In another position, the apertures are aligned with a second subset of the radiation sources. The second subset of the radiation sources define substantially the same radiation field that is defined by the first subset of the radiation sources. A transport apparatus translates the collimator member between at least the first and second positions according to an electronic instruction.

Tomosynthesis combines digital image capture and processing with some portion of the source/detector motion available in 3-D tomography to provide a measure of depth information from an imaged subject. By contrast with computed tomography (CT), digital tomosynthesis uses a small rotation angle, typically between 20° and 40°, with images acquired by varying the orientations of the x-ray tube relative to the patient and detector with a small number of discrete slices/exposures (e.g., 10 exposures). This is usually accomplished by either moving both the detector and x-ray source or by fixing the position of the detector and moving the x-ray source. In applications where the detector is fixed, multiple spatially distributed X-ray sources may be used or one or more movable sources may be discretely displaced and fired in various imaging patterns or trajectories.
The set of image data that is acquired, which is partial with regard to full volume image information, is digitally processed to yield an image similar to tomography but with a limited depth of field. Depth data is reconstructed from the captured projections in the form of a number of slices through the patient anatomy, with the best resolution from each slice taken parallel to the detector plane. A consequence of limited angular scanning for imaging used to reconstruct a 3-D object is that the in depth resolution is characteristically lower than the in-plane resolution of the reconstructed object. Since the image is digitally generated and represented, various processing techniques can be used to generate and present a series of slices at different depths and with different thicknesses reconstructed from the same image acquisition, thereby saving time and reducing radiation exposure.
Because the tomosynthesis data that is acquired is incomplete in terms of full three dimensions of data content, tomosynthesis does not offer the narrow slice widths and enhanced depth definition that CT offers. However, tomosynthesis provides high in-plane resolution and is advantaged over 2-D radiography by providing a measure of depth detail that is not otherwise available with conventional radiography.
A tomosynthesis imaging apparatus may have any of a number of source-detector arrangements for image acquisition. In a distributed array configuration, an array of X-ray sources may be disposed in a generally circular or other geometric distribution. Such a distribution may surround a central X-ray source that may include a standard radiography source, or the distribution may be arranged as a linear or curved path. Distributions of carbon nanotube (CNT) cathode X-ray sources may be arranged to provide tomosynthesis imaging without the need to reposition either the radiation source or the detector. Reference is made to an article by Je Hwang Ryu, Jung Su Kang, and Kyu Chang Park, entitled "Carbon Nanotube Electron Emitter for X-ray Imaging" in Materials, 2012, 5, 2353-2359 which is incorporated herein by reference in its entirety for nonessential background information. Reference is also made to U.S. Pat. No. 8,172,633 to Park et al., filed Apr. 4, 2007; U.S. Patent Application Publication No. 2011/0003109 by Slinker et al., filed Jul. 1, 2009; and U.S. Pat. No. 7,505,562 to Dinca et al., filed Apr. 19, 2007, which are incorporated herein by reference in their entireties.
One difficulty with distributed source arrangements relates to the need for appropriate collimation of emitted radiation. Among its functions, collimation controls the spread of radiographic energy so that it is appropriately directed to the anatomy of interest and so that it does not extend beyond the outer edges of an imaging detector. Collimation also helps to reduce scattering of radiographic energy. With CNT or other types of small x-ray sources in an array, collimation techniques present particular challenges. One set of problems relate to dimensional constraints. Because the spacing between such x-ray sources is typically small, it can be difficult to effectively bound the radiation energy emitted from any individual source. Crosstalk can occur, making it difficult to clearly define edges of the radiation field. Still other complexity relates to identifying the radiation field for imaging from each source. With conventional radiography sources, the problem is readily solved: a light source that is coupled to the radiography source can be used to outline or otherwise highlight a radiation field represented by visible light, by adjusting the collimator edges. However, it can be impractical or impossible to provide a corresponding dual-use arrangement using collimator openings provided for CNT and other types of distributed array sources.
Thus, it can be seen that although there can be advantages in using a distributed array of x-ray sources for tomography and other types of depth imaging, existing collimation strategies fall short of what is needed to more effectively collimate the emitted radiation and generate useful image projections and reconstructions.


A peep device for a poker card game machine includes a box. The box is provided with first and second video cameras, circuit boards having light emitting diodes for fill-in light, and a reflector on top of the box. The reflector has first and second sight holes corresponding in position to the first and second video cameras. When a poker card slowly passes through the first and second sight holes and the first and second video cameras, the suit and the number of the poker card will be displayed slowly for the player to peep at the poker card with excitement. The light emitting diodes illuminate to shoot the poker card clearly.

Field of Invention
The present invention relates to a peep device for a poker card game machine, more particularly to a peep device which is able to display the suit and the number of a poker card for the player to peep at the poker card with excitement.
Description of Related Arts
A conventional poker card game machine is provided with a video camera to shoot and display the suit and the number of a poker card. However, it has the following shortcomings:
1. The video camera shoots the whole card face and immediately displays the suit and the number of the poker card. Thus, the player is unable to peep at the playing card slowly with excitement.
2. It is necessary to provide an illumination light at where the poker card and the video camera are located. The illumination light consumes power and occupies space. Accordingly, the inventor of the present invention has devoted himself based on his many years of practical experiences to solve these problems.


A liquid droplet containing thermosetting or ultraviolet curing adhesive material is jetted out to either of a transfer member (5) or an image receiving member (11) so as to correspond to a shape of an image so that a latent image is formed. The transfer member (5) and the image receiving member (11) are brought into close contact with each other so that the latent image is interposed between the transfer member (5) and the image receiving member (11). Then, heat or ultraviolet rays are applied for curing the adhesive material so that a transfer material formed on the transfer member (5) is fixed to the image receiving member (11) through the cured adhesive material. Then, the transfer member (5) and the image receiving member (11) are separated from each other so that only the fixed transfer material is transferred to the image receiving member (11). As a result, a required image is formed.

1. Field of the Invention
The present invention relates to an image forming method for forming an image by transferring a transfer material such as toner formed on a support member of a transfer member such as a toner sheet to an image receiving member such as an image receiving sheet, and relates to an image forming apparatus.
The present application is based on Japanese Patent Application No. Hei. 10-1725, which is incorporated herein by reference.
2. Description of the Related Art
One of the methods of forming an image on a transfer member, such as paper, is a stripping transfer method. The stripping transfer method uses a transfer member such as a toner sheet which incorporates a support member having a surface on which a transfer layer made of a transfer material such as pigment type toner is formed. The transfer member is superimposed on an image receiving member such as an image receiving sheet which is paper or the like. A thermal head applies heat through a rear side of the support member of the toner sheet to an area corresponding to the shape of a required image. Thus, toner is transferred to the image receiving sheet so that the image is formed on the image receiving sheet. The stripping transfer method may further include a step of sublimating toner to transfer the toner to the image receiving sheet, a step of melting hot-melt toner to cause molten toner to adhere to the image receiving sheet, or a step of causing an image receiving layer of the image receiving sheet to have adhesiveness with heat so that the toner of the toner sheet is fixed.
Further, there is an ink jet recording method in which an ink droplet is jetted out by mechanical energy so as to form an image without thermal recording. The ink jet recording method uses an ink jet recording head which comprises a plurality of nozzle openings arranged in parallel; pressure generating chambers respectively communicating with the nozzle openings and each having walls, a portion of each of which serves as a vibration plate; piezoelectric elements respectively attached onto surfaces of the vibration plates; and a common ink cavity for supplying ink to the pressure generating chambers. Pulse voltage corresponding to image information is applied to the piezoelectric element so that the vibration plate is mechanically deflected. Accordingly, the capacity of the pressure generating chamber is increased or decreased in accordance with the deflection of the vibration plate. By using the instantaneously changed pressure, ink droplets are respectively jetted out from the nozzle openings so that an image is formed on the image receiving sheet.
However, irregular heat conduction among the thermal head, the toner sheet and the image receiving sheet causes the distribution of temperatures to easily vary. As a result, there is a possibility in that images are formed nonuniformly. The stripping transfer method is performed such that a transfer layer which must be sublimated or melted is formed on the toner sheet. As an alternative to this, the image receiving layer arranged to have adhesiveness when heated is formed on the image receiving sheet. Therefore, a range of material separation is narrowed. As a result, the handling characteristic (the sliding characteristic) of the sheet members is limited. Therefore, there is a possibility in that freedom in designing a conveyance passage or the like is limited.
In the ink jet recording method, there is a possibility in that the employed pigment causes light resistance to deteriorate and unsatisfactory preservability to be permitted. Since the ink jet recording head jets out ink droplets directly to the image receiving sheet, bleed may be caused due to the penetration of the ink.
In view of the foregoing, an object of the present invention is to provide an image forming method and an image forming apparatus which are capable of overcoming nonuniform images caused from irregular heat conduction which is the problem of the stripping transfer method and unsatisfactory light resistance and bleed which are problems of the ink jet recording method.
To achieve the above-mentioned object, according to the present invention, there is provided an image forming method which comprises the steps of: providing a transfer member including a transfer material, and an image receiving member; forming a latent image on one of the transfer material and the image receiving member in liquid containing one of a thermosetting adhesive material and an ultraviolet curing adhesive material; bringing the transfer member and the image receiving member into close contact with each other so that the latent image is sandwiched between the transfer material and the image receiving member; applying one of heat and ultraviolet rays to cure the adhesive material so that the transfer material is fixed to the image receiving member through the cured adhesive material; and separating the transfer member and the image receiving member from each other. It is preferable that the image forming method further comprises a step of providing a droplet jetting head, wherein the droplet jetting head jets out liquid droplets to form the latent image on one of the transfer material and the image receiving member. In the image forming method according to the present invention, the transfer member and the image receiving member are separated from each other so that only the portion in which the adhesive material is allowed to adhere is separated from the support member. As a result, the transfer material is transferred to the image receiving member to correspond to the shape of the image so that the image is formed on the image receiving member.
An image forming apparatus according to the present invention comprises: a transfer member including a support member and a transfer material formed on the support member; a droplet jetting head jetting out liquid droplets containing one of a thermosetting adhesive material and an ultraviolet curing adhesive material to form a latent image on an image forming surface of one of the transfer material and an image receiving member, wherein the transfer member and the image receiving member are brought into close contact with each other so that the latent image is interposed between the transfer material and the image receiving member; and an adhesive-material curing device applying heat or ultraviolet rays to the transfer member and the image receiving member so that the adhesive material is cured. Since the image forming apparatus according to the present invention comprises the droplet jetting head and the adhesive-member curing device, liquid droplets containing the thermosetting or ultraviolet curing adhesive material are jetted out to correspond to a shape of an image so as to form a latent image on the surface of one of the transfer material and an image receiving member. The latent image is cured by the adhesive-member curing device so that the transfer material of the transfer member is fixed to the image receiving member to correspond to the shape of the image.
The image forming apparatus according to the present invention may have a structure that a direction in which the liquid droplets are jetted out from the droplet jetting head can be changed to either of a direction toward the transfer member or a direction toward the image receiving member. Accordingly, a preferred image forming surface can be selected when the latent image is formed.
It is further preferable that the image forming apparatus comprises a support drum; and a pinch roller disposed opposite to the support drum in the same axial direction of the support drum. In this case, the transfer member and the image receiving member are inserted between the support drum and the pinch roller so as to be brought into close contact with each other. Moreover, it is further preferable that the pinch roller includes the adhesive-material curing device.

Image forming method and image forming apparatus


An apparatus includes a xerographic cleaning blade, an actuator member operatively connected to the cleaning blade and movable over a first stroke from a first actuator position to a second actuator position, and a damper operatively connected to the actuator member. As the actuator member moves over the first stroke the cleaning blade moves from a first blade position to a second blade position. The damper allows substantially uninhibited actuation of the actuator member over a first portion of the first stroke. The damper damps actuation of the actuator member over a second portion of the first stroke.

The basic principles of electrostatographic printing with dry marking material (hereinafter generally referred to as "xerography," "xerographic printing," and/or the like) are well known: an electrostatic latent image is created on a charge-retentive surface, such as a photoreceptor or other charge receptor, and the latent image is developed by exposing it to a supply of toner particles, which are attracted as needed to appropriately-charged areas of the latent image. The toner particles are then transferred in image-wise fashion from the charge receptor to a print sheet, and the print sheet is subsequently heated to permanently fuse the toner particles thereto and form a durable image. Following the transfer of the image from the charge receptor to the print sheet, residual toner particles and/or other debris left on the charge receptor are typically removed by a blade, a brush, a mesh/web, a vacuum, and/or one or more other suitable "cleaning" or "spot removal" devices. The removed debris is typically accumulated in a hopper and then directed, typically by an auger, into a waste container.
Systems that have employed one or more cleaning blades to separate the debris from their charge receptors have included solenoid driven mechanisms for engaging and disengaging the cleaning blades with the charge receptors. Solenoid drives have generally facilitated simple, low cost, and reliable cleaning blade actuation.
However, an under-damped solenoid drive can cause a cleaning blade to impact or strike the charge receptor at an undesirably high speed on engagement. The resulting abrupt change in frictional drag on the charge receptor can cause motion quality errors and associated image defects for a belt type or a drum type photoreceptor and, additionally, it can cause transverse waves and associated undesirable variations in development for a non-contacting belt type photoreceptor.
Meanwhile, an over-damped solenoid drive can prevent a cleaning blade from cycling (i.e., engaging, disengaging, and then re-engaging a charge receptor) fast enough to meet increasingly high imaging speed demands and/or from moving abruptly enough to facilitate swiping and/or throwing of residual toner from the cleaning blade.
Thus, there is a need for a solenoid driven cleaning blade control apparatus and method that can prevent the cleaning blade from impacting a charge receptor at an undesirably high speed and yet can also still cycle the cleaning blade at high speeds and/or move the cleaning blade abruptly enough to facilitate swiping and/or throwing of residual toner therefrom.

Cleaning blade control apparatus and method


A device for reading and/or writing information from an optical carrier, the device comprising an imager for imaging a radiation beam into scanning spot to scan the carrier, and a detector for generating a read signal indicative of the intensity of the radiation reflected from the carrier. The device has an information transfer mode, wherein the scanning spot is moved in a first direction. The device has a displacement mode, wherein the scanning spot is moved in a second direction transverse to the first direction. The device includes a controller for controlling the imager in response to a measurement signal indicative of the degree of focusing of the radiation beam. The controller samples and holds the measurement signal in response to a sample signal causing the measurement signal to be sampled when the intensity is comparatively high thus reducing radial-to-vertical crosstalk.

1. Technical Field
The invention relates to a device for reading and/or writing information from/onto an optical information carrier, comprising                read means including imaging means for imaging a radiation beam so as to form a scanning spot by means of which the information carrier is scanned, and including detection means for generating a read signal which is indicative of the intensity of the radiation reflected from the information carrier at the location of the scanning spot,        which device has an information transfer mode, in which the scanning spot is moved in a first direction with respect to the information carrier,        which device has a displacement mode, in which the scanning spot is moved in a second direction transverse to the first direction,        control means for controlling the imaging means in response to a measurement signal which is indicative of the degree of focusing of the radiation beam at the location of the scanning spot, which control means include sample and hold means for sampling and holding the measurement signal in response to a sample signal.
2. Related Art
From U.S. Pat. No. 5,245,598 a device is known which is suitable for scanning a magneto-optical disc-shaped information carrier. In the information carrier described therein the information is recorded in mutually concentric tracks which are separated by grooves. The information is recorded by forming magnetic patterns in the information carrier. The information is read by focusing a radiation beam is focused onto the information carrier and by measuring the polarization of the beam reflected from the location of the scanning spot thus formed. The scanning spot is then moved in a first direction, i.e. along the tracks. With the aid of detectors a focus error signal is derived from the reflected radiation. A sample and hold circuit generates a sampled focus error signal from the focus error signal. In response thereto a control system generates a control signal for focusing the beam. In a displacement mode of the device the sample and hold circuit is controlled by a tracking error signal, the focus error signal being sampled if the scanning spot is incident on a track and is maintained constant if the scanning spot is incident on a groove. According to said document the focus servo mechanism is preferably in a continuous sample mode during scanning of the information carrier. The measures taken in the known device suppress radial to vertical crosstalk (RV crosstalk) during a radial movement of the scanning spot on a magneto-optical information carrier as described above. However, the known measures do not suppress RV crosstalk which occurs in optical information carriers which store the information in the form of differences in level.

Device for reading and/or writing information from/onto an optical information carrier


A prosthetic valve for replacing a cardiac valve includes an expandable support member and at least two valve leaflets made of a first layer of biological material selected from peritoneal tissue, pleural tissue or pericardial tissue. A second layer of biological material is attached to the support member. The second layer is also made from peritoneal tissue, pleural tissue or pericardial tissue. The second layer includes a radially inwardly facing surface that defines a conduit for directing blood flow. The valve leaflets extend across the conduit to permit unidirectional flow of blood through the conduit. Methods for making and implanting the prosthetic valve are also provided.

Surgical procedures in which a cardiovascular prosthesis is implanted into a patient's blood vessel are common in treating many vascular disorders. For example, one common type of cardiovascular prosthesis is an endovascular prosthesis that is used to strengthen a blood vessel wall in the location of an aneurysm, or to open an occlusion in a blood vessel.
A typical endovascular prosthesis includes a flexible, tubular member, made of fabric or PTFE, that may be anchored with sutures or carried by one or more support structures known as stents. Generally, each stent is formed from a material having an elasticity that is sufficient to permit radial expansion of the stent and having a strength sufficient to prevent radial collapse or burst. Such stents are typically formed from stainless steel, titanium, Nitinol, or a suitable plastic.
A common endeavor in the field of cardiovascular prosthetics is to increase the patency rate of prostheses. Thrombosis and platelet deposition on surfaces of a cardiovascular prosthesis reduce the patency rate of the prosthesis. For example, thrombosis and platelet deposition within an endovascular prosthesis may occlude the conduit defined by the endovascular prosthesis.
Many factors contribute to thrombosis and platelet deposition on the surfaces of known cardiovascular prosthesis. The most common factors are dependent upon the material or materials forming the inner surface of the conduit of the endovascular prosthesis. Typically, thrombosis and platelet deposition begin to occlude the conduit of the endovascular prosthesis when the material or materials forming the conduit of the endovascular prosthesis are foreign to the patient's body. Thrombus begins to form on the inner surface of the conduit of the endovascular prosthesis and extends annularly about the inner surface of the conduit. Eventually, the thrombus can severely restrict blood flow through the conduit defined by the endovascular prosthesis and, if left untreated, can completely occlude the conduit.
Additionally, thrombosis and platelet deposition may occur as a result of irregularities on the inner surface of a cardiovascular prosthesis. The irregularities may be formed by the structure of an inner stent that is used to support the cardiovascular prosthesis, or may be formed by the inner surface of the flexible member used for the prosthesis.
Another common type of cardiovascular prosthesis is a prosthetic cardiac valve. Prosthetic cardiac valves have been used to replace all four of the native cardiac valves. Cardiac valve replacement has traditionally been done though an invasive open surgical procedure, although percutaneous approaches are being developed.
The four native cardiac valves (mitral, aortic, tricuspid, and pulmonary) serve to direct the flow of blood through the two sides of the heart in a forward direction. On the left (systemic) side of the heart, the mitral valve is located between the left atrium and the left ventricle, while the aortic valve is located between the left ventricle and the aorta. These two valves direct oxygenated blood coming from the lungs, through the left side of the heart, into the aorta for distribution to the body. On the right (pulmonary) side of the heart, the tricuspid valve is located between the right atrium and the right ventricle, while the pulmonary valve is located between the right ventricle and the pulmonary artery. These two valves direct de-oxygenated blood coming from the body, through the right side of the heart, into the pulmonary artery for distribution to the lungs, where it again becomes re-oxygenated to begin the circuit anew.
All four of these native heart valves are passive structures that do not themselves expend any energy and do not perform any active contractile function. The valves consist of moveable leaflets that open and close in response to differential pressures on either side of the valve. The mitral and tricuspid valves are referred to as atrioventricular valves because they are situated between an atrium and a ventricle on each side of the heart. The mitral valve has two leaflets and the tricuspid valve has three leaflets. The aortic and pulmonary valves are referred to as semilunar valves because of the unique appearance of their leaflets, which are often termed "cusps" and which are shaped somewhat like a half-moon. The aortic and pulmonary valves each have three cusps.
Heart valves can exhibit abnormal anatomy and function as a result of congenital or acquired valve disease. Congenital valve abnormalities may be so severe that emergency surgery is required within the first few hours of life, or they may be well-tolerated for many years only to develop a life-threatening problem in an elderly patient. Acquired valve disease may result from causes such as rheumatic fever, degenerative disorders of the valve tissue, bacterial or fungal infections, and trauma.
The two major problems that can develop with heart valves are stenosis, in which a valve does not open properly, and insufficiency (also called regurgitation), in which a valve does not close properly. Stenosis and insufficiency may occur concomitantly in the same valve or in different valves. Both of these abnormalities increase the workload and stress placed on the heart. The severity of this increased stress on the heart, and the heart's ability to adapt to it, determine whether the abnormal valve will have to be surgically repaired or replaced.
In addition to stenosis and insufficiency of heart valves, surgery may also be required for certain types of bacterial or fungal infections in which the valve may continue to function normally, but nevertheless harbors an overgrowth of bacteria on the leaflets of the valve that may flake off (or embolize) and lodge downstream in a vital artery. If this occurs on the valves of the left side (i.e., the systemic circulation side) of the heart, embolization results in sudden loss of the blood supply to the affected body organ and immediate malfunction of that organ. The organ most commonly affected by such embolization is the brain, in which case the patient suffers a stroke. Thus, surgical replacement of either the mitral or the aortic valve may be necessary for this problem even though neither stenosis nor insufficiency of either valve is present.
If a heart valve must be replaced, there are currently several options available, and the choice of a particular type of prosthesis (i.e., artificial valve) depends on factors such as the location of the valve, the age and other specifics of the patient, and the surgeon's experiences and preferences. Available prostheses include mechanical valves, tissue valves, and homograft valves. Mechanical valves include caged-ball valves, bi-leaflet valves, and tilting disk valves. The main advantage of mechanical valves is their long-term durability. Their main disadvantage is that they require the patient to take systemic anticoagulation drugs for the rest of his or her life, because of the propensity of mechanical valves to cause blood clots to form on them. Mechanical valves can be used to replace any of the heart's four valves and are typically attached to a fabric sewing ring so that the valve prosthesis can be sutured to the patient's native tissue to hold the artificial valve in place postoperatively.
Tissue valves are typically constructed either by sewing the leaflets of porcine aortic valves to a stent (to hold the leaflets in proper position), or by constructing valve leaflets from porcine or bovine pericardial tissue and sewing them to a stent. The stents may be rigid or slightly flexible and are typically covered with a fabric, such as the material sold under the trademark DACRON™, and then attached to a sewing ring for fixation to the patient's native valve annulus. The porcine or bovine tissue is chemically treated to alleviate any antigenicity (i.e., to reduce the risk that the patient's body will reject the foreign tissue). Tissue valves may be used to replace any of the heart's four valves. The main advantage of tissue valves is that they do not cause blood clots to form as readily as do the mechanical valves, and therefore, they do not absolutely require systemic anticoagulation. Nevertheless, many surgeons do anticoagulate patients who have any type of artificial mitral valve, including tissue valves. The major disadvantage of tissue valves is that they lack the long-term durability of mechanical valves.
It should be noted that the structure associated with mechanical valves and tissue valves decreases their hemodynamic performance. Such obstructions also interfere with the normal flow patterns within and around the prosthetic valve and therefore, promote thrombosis as all artificial surfaces are thrombogenic (clot-promoting) to a greater or lesser degree.
Homograft valves are harvested from human cadavers. Homograft valves are most commonly implanted in the aortic position, but are also occasionally implanted in the pulmonary position. Homograft valves are specially prepared and frozen in liquid nitrogen, where they are stored for later use. The advantage of aortic homograft valves is that they appear to be as durable as mechanical valves, but do not promote blood clot formation and therefore do not require anticoagulation. The main disadvantage of these valves is that they are not available in sufficient numbers to satisfy the needs of patients who need new aortic or pulmonary valves. Homograft valves are also extremely expensive and can be more difficult to implant than either mechanical valves or tissue valves.

Prosthetic cardiac value and method for making same


An electric circuit arrangement for controlling a solenoid-operated fluid valve.

Such a circuit arrangement is known from the printed publication "Electric Amplifier Module for Controlling Directly Controlled Regulating Valves having an Electric Feedback of Type VT 11080, Series 2X" (RD 29 757/04.93) of the Mannesmann Rexroth GmbH. The circuit arrangement has an amplifier circuit having an input stage and an output stage. The input stage is supplied with an electrical input signal, e.g. in the form of a direct voltage variable between 0 and 10 V. This voltage is in the most simple case a voltage tapped off from a potentiometer. Alternatively, this may be a voltage supplied by a programmable controller normally referred to as "SPS" or a voltage supplied by another primary controller. The voltage supplied to the input stage is used as a setpoint value for the current that is to be supplied to the solenoid coil. If required, other signals may be added in the input stage to form a control signal for the output stage. The output stage converts the control signal into a current. This current is supplied to the solenoid coil via connecting lines situated between the output stage and the solenoid coil. For this purpose, e.g. a range of the current between 0 and 1 A corresponds to a range of the input voltage from 0 to 10 V.
In order to satisfy the safety requirements of the ATEX regulations, it is necessary, among other things, to ensure that the surface temperature of the individual components of a system is always lower than the ignition temperature of the gas surrounding the components. In the case of electrically controlled fluid valves having a control element operated by a solenoid coil, the solenoid coil is a component that heats up in operation as a function of the current. What makes things more difficult in this regard is the fact that the boundary values for the current flowing across the solenoid coil in many cases lies just barely above the value required for the full deflection of the control element of the fluid valve. This means that the safety margin between the current required for the full deflection of the control element of the fluid valve and the boundary value of the current specified by the construction of the solenoid coil is in the order of only a few percent, e.g. 5% of the greatest operationally intended current. In normal operation, this boundary value is not reached; but a series of cases are conceivable, in which the boundary value of the current flowing across the solenoid coil is reached and even exceeded. This includes e.g. an overloading of the amplifier input in which the input voltage supplied to the input stage of the amplifier is greater than the input voltage associated with the greatest operationally intended current. Another case, in which a current exceeding the boundary value may occur is a faulty operation of the parameter setting of the amplifier on the part of the customer, which results in an output current that exceeds the greatest operationally intended current. Another conceivable case, in which a current exceeds the boundary value, may occur in the event of a short circuit between a line conducting an operating voltage and a connecting line leading from the amplifier to the solenoid coil. Printed publication RD 29 757/04.93 does not specify measures to prevent an unacceptably high heating of the solenoid coil in such cases.
From German Published Patent Application No. 195 15 640, a circuit arrangement is known for electrically controlling a solenoid-operated fluid valve. A controlled switch in the form of a contact of a contactor relay is situated in the connecting lines between an amplifier and a solenoid coil. This controlled switch is used to satisfy increased safety-related requirements such as must be met e.g. when using electrically operated hydraulic valves for controlling the flow of the pressure medium to cylinders that move the tools of a molding press. In a hazardous operating state it must be possible to shut down the machine in a safe manner. This is to occur e.g. if an end switch responds as the upper dead center of the press is reached, if an emergency switch has been operated or if a primary controller outputs an appropriate signal. In these cases, an enable signal is removed, which, in addition to the other functions it performs, also opens the controlled switch. If the valve is configured as a proportional valve having positive overlap and mechanical centering of the control piston, then, when no current is supplied to the solenoid coil, the control piston assumes a safe center position in which no pressure medium flows to or from the cylinder. Opening the controlled switch thus ensures that no current flows across the solenoid coil even in the case of an electrical fault of the amplifier. The circuit arrangement known from German Published Patent Application No. 195 15 640 does not address measures for preventing an unacceptably high heating of the solenoid coil.
A device for switching an electrohydraulic solenoid-operated directional control valve is known from German Published Patent Application No 24 26 512. Operating in normal operations as a switching transistor, a transistor, in accordance with a clocked control current that is supplied to its base terminal, connects in one switching state a solenoid coil to a supply voltage, while interrupting this connection in the other switching state. The magnitude of the current flowing across the solenoid coil is determined by the ohmic resistance of the solenoid coil and the magnitude of the supply voltage. For protecting the switching transistor, a protective circuit is provided, which opens a contact of a relay situated between the supply voltage source and the solenoid coil whenever a higher current than the normal operating current flows. In the case of a current that is only slightly greater than the normal operating current, the relay opens the contact between the supply voltage source and the solenoid coil. Afterward, the current flow remains interrupted due to a self-holding mechanism in the relay. In the case of a current that is significantly greater than the normal operating current, the control current of the switching transistor is additionally reduced in the time interval until the response of the relay. This circuit arrangement relates to an output stage, which applies a clocked voltage to a solenoid coil. No input stage is provided which converts a variable input voltage via a current controller or current regulator into a current corresponding to the magnitude of the input voltage such as e.g. in the circuit arrangement known from the printed publication RD 29 757/04.93 mentioned at the beginning. The problem of a limitation of the surface temperature of the solenoid coil is also not addressed.

Electric circuit arrangement for controlling a solenoid-operated fluid valve