It has been discovered that vascular endothelial growth factor (“VEGF”) promotes migration of activated (but not differentiating) keratinocytes to skin. This growth factor specifically increases migration of keratinocytes of the “wounded skin” phenotype but does not have significant effects upon differentiated keratinocytes. It also increases collagen deposition and reduces wrinkles, enhances skin quality, and increases skin thickness to normal levels in individuals where skin has thinned due to age or disorder such as diabetes. It is particularly well suited for use as cosmeceuticals when applied in purified form and in known amounts. The data presented in the examples demonstrate efficacy and specificity of VEGF in enhancing migration of normal human keratinocytes as well as formation of new granulation tissue including collagen formation. VEGF induces keratinocyte and fibroblast migration, formation of new tissue, and not only induces deposition of collagen but improves alignment of the collagen fibers. Accordingly, this growth factor is highly suitable for use as a cosmeceutical, especially for skin resurfacing and reduction in wrinkles.

Current popular methods to treat facial signs of aging are many and very limited. The popular BOTOX® Cosmetic—with 3.3 million people receiving treatment last year—works by using a low dose of a potent toxin to temporarily paralyze the muscles surrounding the wrinkles, thus smoothing their appearance. However it is limited. Popular ingredients such as alpha-hydroxy acids and retinols can cause the skin to dry and tighten, which could worsen the appearance of wrinkles. Collagen injections can trigger allergic reactions or yield uneven results.
Vascular endothelial growth factor (VEGF), is known by most medical professionals as a sign for poor survival in cancer patients because a tumor will express higher levels of VEGF when it is metastasizing. VEGF serves an important function of facilitating new blood vessel formation. Therefore, a lot of medical attention has been paid to "anti-VEGF" components to try to inhibit the growth and spread of tumors. VEGF's ability to promote blood vessel formation is making it increasingly popular as an ingredient in various cosmeceutical products that claim to fight the appearance of aging skin. One of the biggest problems in treating wrinkles and other signs of aging is getting active ingredients past the natural protective barriers of the skin's surface. However, studies have shown that VEGF may serve to increase permeability in surfaces such as the skin, making its anti-aging effects even more potent.
One successful cosmetic application including VEGF is in Nouricel-MD®, manufactured by Advanced Tissue Sciences. U.S. Pat. No. 6,372,494 describes a method of obtaining growth factors in which cosmetic pursuits are stated as a possible use for the harvested growth factors. Nouricel-MD is used in a concentration of 93% by SkinMedica, a dermatological corporation, in their non-prescription product Tissue Nutrient Solution (TNS) Recovery Complex, which claims to "enhance skin texture, reduce the appearance of age spots and blotchiness, and improve skin elasticity". Its only claim specific to VEGF is that it is "believed to" stimulate blood vessel formation. The SkinMedica supports its claims by referencing one study, "Reversal of Photodamage with Topical Growth Factors: a Pilot Study" (Fitzpatrick, Rostan, 1995 Cosmetic Laser Associates).
The so-called "Transformation" line manufactured by Jan Marini Skin Research, Inc. contains a moisturizer, serum, and eye cream that all contain a mixture of growth factors, including VEGF. U.S. Pat. No. 6,821,524 details the use of VEGF as "it has been reported that VEGF increases the permeability of blood vessels" and uses a 1995 study by Palade and Roberts to support this claim. The Palade and Roberts study she cites, however, was not conducted on human skin, yet she claims in the parent "the compositions of the invention find use in improving the appearance of fine lines and wrinkles, i.e. in sun damaged skin, etc."
U.S. patent Application Nos. 20040265268 and 20030068297 both claim that a cosmetic product containing a blend of biological growth factors, including VEGF, would be effective to fight the appearance of aging skin, promote hair growth, as well as have wound-healing properties, based on its use as "a protein that stimulates the growth of new blood vessels". The applications claim that the products will "repair and rejuvenate mammalian skin" and "reduce the appearance of fine facial lines and wrinkles.
Aging skin is a common concern, and there is a large demand in the market for products to combat the appearance of aging skin, characterized by fine lines, wrinkles, age spots, and loss of elasticity. The latest for treatment of this aesthetic problem is the use of pharmaceutical components, like growth factors and retenoid in topical application. Such products are known unofficially as cosmeceuticals. These contain mixtures of many different things.
From a biological standpoint, an effective plan for rejuvenating and repairing skin must address the rejuvenation of skin cells at both the epidermal and the dermal layers, protection of the rejuvenated cells and cellular activity, stimulation of the production of skin matrix elements, and the sustainability of the rejuvenated conditions over the long term.
It is therefore an object to provide a purely biologic formulation that stimulates the dermis and epidermis and is dose responsive.
It is another object to provide compositions that enhance migration of keratinocytes and collagen deposition to reduce wrinkles, enhance skin quality, and increase skin thickness to normal levels in individuals where skin has thinned due to age or disorders such as diabetes, and which is useful as a cosmeceutical.
It is a further object of the present invention to provide a cosmeceutical containing controlled amounts of specific growth factors, which have defined dosage ranges and proven efficacy.

Methods of increasing collagen formation and cellular migration in intact skin


A heat-resistant, lubricative resin composition which can withstand temperatures of 250-270.degree. C., which is wear-resistant and low in friction, and which is less likely to attack a soft alloy such as aluminum alloy, and a high-performance, heat-resistant sliding bearing formed from the abovementioned heat-resistant, lubricative resin composition. The resin composition is made up of a thermoplastic polyimide resin represented by the following formula, and 8-38% by volume of tetrafluoroethylene resin and 3-25% by volume of aromatic polyester resin, ##STR1## (where X is a direct connection or a group selected from the group consisting of a hydrocarbon group having 1-10 carbon atoms, a hexafluorinated isopropylidene group, a carbonyl group, a thio group and a sulfonic group; R1-R4 are hydrogen, lower alkyl groups, lower alkoxy groups, chlorine or bromine, and may be the same or different from one another; Y is a tetravalent group selected from the group consisting of an aliphatic group having two or more carbon atoms, a cyclic aliphatic group, a monocyclic aromatic group, a condensed polycyclic aromatic group, a non-condensed polycyclic aromatic group made up of aromatic groups coupled together direcly or through crosslinking agents.)

This invention relates to a heat-resistant, lubricative resin composition and a heat-resistant sliding bearing which can be used as sliding members of a heating/fixing unit in an electrophotographic device.
Sliding bearings of synthetic resin are now used in broader fields of art than before. It is required that such sliding bearings have high heat resistance so that they can exhibit good friction/wear properties especially at elevated temperatures. Such heat-resistant bearings are used e.g. in heating/fixing units for copying machines and laser beam printers.
Today, many of mating members of these bearings are made of a lightweight and soft material such as aluminum alloy. Thus, it is required to use bearings that will never damage even such soft mating members.
We will now describe how sliding bearings are used in heating/fixing units of copiers and laser beam printers.
Copiers and laser beam printers for transferring data on original images to recording material or transfer material in the form of charged images are also called electrophotographic devices. FIG. 3 shows a heating/fixing unit of such a device. It has a heating roller 10 for heating and fixing toner images on a transfer material, and a press roller 11 for rotating the transfer material by pressing it against the heating roller 10.
The heating roller 10 is in many cases made of an Mg-containing aluminum alloy and is heated by a heater 12 to about 150-230.degree. C. The press roller 11 is made of iron and covered with e.g. silicone rubber. It is heated to about 70-150.degree. C. by heat transfer from the heating roller 10.
FIG. 4 shows a different heating/fixing unit. It has, instead of the metallic heating roller 10, an endless annular fixing film 15 made of a heat-resistant synthetic resin and having a release coating. A ceramic heater 16 is pressed against the press roller 11 through the fixing film 15 to improve heat transfer efficiency. The press roller 11 of this unit is heated to higher temperatures than the press roller 11 of the unit shown in FIG. 3, in which the metallic heating roller 10 is used.
The rollers, which are heated to high temperatures as described above, are supported at both ends by synthetic resin sliding bearings 13 and 14 (in FIG. 3) or by sliding bearings corresponding to bearings 14 (in FIG. 4). Conventional such bearings were made of polyphenylene sulfide (hereinafter referred to as PPS) resin because of its high heat resistance. PPS resin is a thermoplastic synthetic resin having good heat resistance and mechanical strength. But it has poor self-lubricating properties, so that it is usually necessary to add graphite, tetrafluoroethylene resin, lubricating oil, metallic oxides, aromatic polyamide resin, etc. as lubricants.
For higher performance of an electrophotographic device having sliding members made of synthetic resin, more specifically, in order to increase its copying or printing speed, it is necessary to melt and fix toner as quickly as possible. For this purpose, it is essential that the sliding bearings 13 and 14 be made of a material that can withstand heating up to a temperature of 250-270.degree. C.
In this regard, the conventional sliding members made of PPS resin, having a melting point near 280.degree. C., are not sufficiently heat-resistant for the above the purpose.
Unexamined Japanese Patent Publication 63-8455 proposes to improve the sliding properties of an inherently heat-resistant polyimide resin by adding tetrafluoroethylene resin.
Unexamined Japanese Patent Publication 63-314712 proposes to add tetrafluoroethylene resin and a hardened phenolic resin to a polyimide resin to improve its wear resistance.
Such conventional sliding members made of polyimide resins exhibit good sliding properties with respect to mating members which are hard at room temperature. But if they are brought into sliding contact with mating members made of a soft metal such as aluminum or an aluminum alloy, they tend to severely damage the mating members.
It is of course impossible to prevent damage to soft aluminum alloys simply by adding carbon fiber to the compositions. When the mating members are damaged, friction/wear properties may be aggravated.
An object of this invention is to provide a heat-resistant, lubricative resin composition which can withstand temperatures of 250-270 C., which is wear-resistant and low in friction, which is less likely to attack a soft alloy such as aluminum alloy, and which have superior properties to any conventional composition formed mainly from a polyimide resin, and high-performance, heat-resistant sliding bearings formed from the abovementioned heat-resistant, lubricative resin composition.

Heat-resistant lubricative resin composition


Bi-directional multi-resolution scanner having software/firmware for 1- to 2-pass high resolution scanning, enabling the scanner to capture and render image data both the standard direction, top to bottom pass, as well as the return direction, that is, bi-directional scanning, in contrast to prior art scanners which return to the start position after each pass without reading (scanning). Typical current B&W scanning of an 8½×11″ image at 600 dpi takes a total time from start to reload to the next image of on the order of 42-67 seconds. In contrast, the inventive system scans and displays the high resolution image in about 37 seconds, some 7-30 seconds faster than a conventional scanner. In multiple image scanning, since the time for the two return passes and the preview pass is eliminated, the productivity is increased from 20 to 300% or more. Since multiple non-scan return passes are eliminated, the inventive system is also a substantial improvement for limited power bus devices.

The background of this invention involves digital scanners and software based methods. Presently, typical scanners provide very high optical resolutions and brilliant color depth. However, the superior imaging quality typically results in long scan times and slow imaging speeds.
The optical resolution of the images scanned by digital scanners is a function of the number of pixel capture sites (also called "photosites" or "pixels" in the electro mechanical sense) on the electro-mechanical sensor assembly in the scanner. Scanning is done in a Cartesian mode, i.e., a linear array of the pixel sites are mounted on a longitudinal bar; the bar is moved as a unit along a vertical path. Each pixel is a small area on the surface of the image sensor that captures the brightness of a single image area pixel of the image, with one scanner pixel for each image pixel in the digital image. In that way, the number of pixels on the scanner's image sensor bar determines the horizontal optical resolution. The distance the bar advances between acquisitions (also called "shots") determines the vertical resolution. For example, a scanner with a resolution of 600 dots per inch (dpi)×1200 dpi has 600 pixels on its sensor bar which moves 1/1200 of an inch between each scan shot. Together, the horizontal and vertical resolutions constitute the optical resolution and determine the level of detail that the scanner can capture.
To increase the resolution of a scanner, the number of pixel sites on the scanner head (the "horizontal" or transversely aligned bar containing the linear array of CCD or CIS photosensitive elements) must be increased, the distance the scanner bar mechanism moves between acquisition shots (the "vertical" or longitudinal resolution) must be decreased, or some combination of the two. Current technology offers two basic types of pixels: CSI and CCD (other types of elements may become available in the future). There is a technological constraint on the horizontal resolution, which is determined by the number of pixels arrayed on the bar due to their physical size and how closely they can be positioned to one another. To increase the vertical resolution, digital scanners must move smaller and smaller distances between scans. Since the illumination lamp output changes over time, and the length of exposure depends on brightness and dpi, the scanner head is ordinarily calibrated from time to time (often at each scan) to control the length of pause for exposure at each acquisition shot. CSI element-containing scanner bars are typically slower as they require more light per exposure, and the slow down is more pronounced at low resolution.
Typical digital scanners today provide vertical optical resolutions of 1200 to 4800 dpi. Thus, the scanner mechanism moves 1/1200 to 1/4800 of an inch between each single line shot or scan. This process generates a large quantity of digital data (large image data file), which needs to be transferred to the host system (computer). Because of limitation in the communication speed with the hose, high-resolution scans take a long time, with typical scanners on the market presently taking two minutes or more to complete a single pass at the highest resolution for the full length of the scanner platen (typically 11.69″). Current CCD scanner bars employ around 3×10,400 pixels (the "3" refers to the colors R, G, B), and scanner bars having higher resolutions are within the scope of this invention. The net actual attainable resolution is not determined only by the pixel density, but in large part is determined by the optics of the scanner. For example, most scanners rated at "1200 dpi" resolution are limited to 600 dpi or less due to optical constraints.
The high-resolution scan is slower than preview scanning, the rate depending on the resolution. The scan bar moves at a speed proportional to the resolution, regardless of whether the image is in B&W, grayscale or color, and how fast the data can be transferred to the host. The scan speed is dependent on the resolution, color/ grayscale/B&W, and transfer-to-host speed, but is independent of the area of the image being scanned. That is, if nothing is on the platen, even though the scanner head sees "white", where high resolution is the selected scan mode, the scan speed is slower than if preview or low resolution is selected as the scan mode. Although some scanners may have a relatively fast return feature in which the non-scanning return to the start position is faster than scan, that return time is still wasted wait time. CIS heads are slower than CCD, and for large color photo images, the data files can be very large, with consequently slow transfer. For a CCD head scanning an 8½″×11″ image on a standard 8.7×11.69″ platen, the scan times are set forth in Table 1 below.
TABLE IScan Time at Various ResolutionsScan Time in Seconds, for8.5″ × 11″ ImageResolution, DPIB & WColor10078300203060030120
Return speed typically ranges from 3½ seconds to 15 seconds, depending on the scanning motor type and the return speed is set, not variable or programmable. CIS head return speeds are slower.
Image Cropping:
In order to reduce scanning time and to reduce file size, present scanner manufacturers allow users to either manually, or automatically, make a single, low resolution scan, e.g., at 72-100 dpi. An example of current cropping hardware and software technology is shown in Santos, U.S. Pat. No. 4,837,635 (Hewlett-Packard). The image created from the preview scan by the digital scanner is rectangular in shape and consists of an image of everything on the flatbed scanner, e.g., the document being scanned as well as all the blank space around that document. The software or firmware of the systems creates a low-resolution image, and either the user or an automatic cropping algorithm selects the desired region of the image. The user or cropping algorithm draws a box or "lasso" around the image and then transmit to the scanner the instruction to scan, at a high resolution, the area marked off by the crop box or lasso. While the user or cropping algorithm selects the region of the low-resolution image to rescan, the scanner bar returns to its normal starting position in order to prepare to make the next, high-resolution, scan, e.g., 300, 600, 1200 or more dpi. Cropping and B&W scanning reduces data transfer time, cropping because there is less total data, and B&W because it is 1 bit vs 24 bit data for color. With automatic cropping algorithms, the cropping action may take a fraction of a second, but currently available scanners take time for the scan bar to return to its starting position to begin the high-resolution scan.
A serious disadvantage of the present scanning/cropping technology arises from the number of passes that the scanner bar must take in order to acquire and render the final high-resolution, useable image on screen for saving to a data file. Typically, currently available scanners take 4 passes per image: 1) Low resolution preview/crop; 2) return; 3) high resolution acquisition scan; and 4) return. Where there are multiple images to acquire, this process takes a very long time, and adds significant cycle wear to the scanner hardware.
There is thus a significant need for a scanning system that automatically crops and acquires high resolution images in short, fast scanning cycles that permits faster through-put and reduced component cycle wear.

Fast, auto-cropping, bi-directional multi-resolution scanner apparatus, system and software therefor


A message transport network (10) is provided for high speed switching between processing elements (72, 80). Clusters of low speed processing elements (72) may be connected to the message transport network (10) through a transport node controller (78). The transport node controller (78) and the high speed processors (80) are connected to the gateways (82). A pair of gateways (82) may be connected through a transport interchange node (106) to allow communication between processors (72, 80) associated with the gateways (82). A transport interchange supervisor (98) maintains a record of the status of each gateway (82) and generates commands to form connection between gateways (82) in the transport interchange node (106). A maintenance controller (102) and system maintenance processor (76) oversee the validity of the data being passed through the system on paths independent of the data transfer paths. The message transport network (10) may be used in variety of applications, such as a telephony switch (11), a signaling transfer point system (21) or a fault tolerant minicomputer (49).

The integrated services digital network (ISDN) and its associated message oriented signaling protocols place new and demanding requirements on core switching technologies. In order to meet the ISDN specification, an efficient method of interconnecting a large number of high performance processors in a distributed processing system must be provided.
Previously developed systems suffered from a variety of inadequacies. First, the number of simultaneous connections between processing elements is limited, and the rate at which connections may be achieved is unsuitable, particularly for future applications. Preferably, up to thirty-two simultaneous connections would be supported, with a maximum connection rate approaching 2.5 million connections per second.
Further, present day systems do not offer flexibility in optimizing the cost of the system versus the failsafe mechanisms for overcoming partial system failures. Because the amount of system redundancy will vary depending on the application in which the switching network is used, it is beneficial that the switching network allow for selective redundancy for providing high availability in the most important subsystems.
Additionally, present day switching networks do not allow for cost effective growth capabilities, but rather, force the user to buy a new switching network to accommodate system expansion. Thus, present day switching networks do not offer both short and long term cost effectiveness for growing companies.
Another important aspect of switching networks is their ability to isolate and detect faults. In the telecommunications area, it is important to detect and isolate errors so that faulty data does not propagate through to other processing systems.
Thus, a need has arisen for a switching network capable of a large number of simultaneous connections and a fast connection rate, which offers high system availability and growth possibilities. Furthermore, the switching network system should have an effective means for detecting and isolating system faults and taking corrective measures.


Provided are a phase change material containing carbon (C), a memory device including the phase change material, and a method of operating the memory device. The phase change material contains a main compound and an additive, wherein the main compound is In—Sb—Te and the additive includes carbon (C). A content a of the carbon (C) may be 0.005≦a≦0.30 atomic (at) %. The additive may further contain nitrogen (N), oxygen (O), boron (B), or a transition metal. The additive may include carbide instead of the carbon (C).

1. Field of the Invention
The present invention relates to a memory material and a memory device including the memory material, and more particularly, to a phase change material containing carbon (C), a memory device including the phase change material, and a method of operating the memory device.
2. Description of the Related Art
A phase change random access memory (PRAM) is a non-volatile memory device and has advantages of a dynamic random access memory (DRAM) that is a representative volatile memory device.
A characteristic of a PRAM is that a storage node in which data is stored includes a phase change layer that is changed between an amorphous state and a crystalline state in accordance with temperature variations.
A commonly-used phase change layer of a PRAM is a Ge2Sb2Te5 layer (hereinafter, referred to as a GST layer). A GST layer has a low crystallization temperature (Tc) of 160° C. and thus a set current (Iset) is low.
Due to the fact that the distance between adjacent unit memory cells of a PRAM is getting smaller as the integration density of memory devices is increasing, if the Tc is low, when a selected cell is crystallized, a neighboring cell may be affected. That is, cell disturbance may occur. Cell disturbance may damage data written in an unselected cell and thus may deteriorate reliability of data. Also, if the Tc of the phase change layer is low, a retention characteristic or an infrared (IR) reflow characteristic may be poor.
Meanwhile, a melting temperature (Tm) of the GST layer at which the GST layer is changed from the crystalline state to the amorphous state is a relatively high temperature of 620° C. Thus, if the PRAM uses the GST layer as the phase change layer, a current for changing the phase change layer from the crystalline state to the amorphous state, in other words, a current for writing data, that is, a reset current (Ireset), may be relatively high.
In order to overcome the above disadvantage of the GST layer, an In3Sb1Te2 layer may be used as the phase change layer. In comparison to a GST layer, an In3Sb1Te2 layer has advantages as described below.
First, an In3Sb1Te2 layer has a Tc of 265° C. that is more than 100° C. higher than the Tc of a GST layer and thus thermal stability and retention characteristics of a PRAM including an In3Sb1Te2 layer as the phase change layer may be improved in comparison to a case when a GST layer is used.
Second, an In3Sb1Te2 layer has a relatively low Tm of 560° C. and thus the Ireset may be lowered.
Third, an In3Sb1Te2 layer has a high resistance in an amorphous state and a low resistance in a crystalline state and thus a sensing margin may be increased.
Fourth, a crystal structure of the In3Sb1Te2 layer is face-centered cubic (FCC) such that the phase change rate is fast. Thus, operating speed of a PRAM including the In3Sb1Te2 layer may be increased.
In spite of these advantages, the In3Sb1Te2 layer may be easily resolved into (InTe)2+(InSb)1 by a peritectic reaction. Thus, a single phase may not be easily formed and even if a single phase is formed, phase separation may easily occur.
As a result, in spite of its many advantages as the phase change layer of a PRAM, a conventional In3Sb1Te2 layer may not be easily applied to a PRAM.

Phase change material containing carbon, memory device including the phase change material, and method of operating the memory device


A magnetic resonance experiment is described in which a sample under test is subjected to a sequence of gradient magnetic fields and RF pulses and resultant pulse echoes are monitored. At least one of the RF pulses comprises a prefocused, phase-modulated, time-asymmetric RF pulse.

The invention relates to a magnetic resonance experiment in which a sample under test is subjected to a sequence of gradient magnetic fields and radio frequency pulses and resultant pulse echoes are monitored. The invention also relates to apparatus for performing such an experiment.
In a typical magnetic resonance imaging experiment, after initial excitation of selected spins, in which spins at different spatial positions are encoded with different resonant frequencies by the superposition of a linear magnetic field gradient upon the main field, the signal detection must take place in the presence of a similar field gradient, in order for the spatial encoding to be maintained. In the presence of this gradient, spins have different precessional frequencies, and so dephase. Fourier imaging techniques rely on phase-encoding, that is the application of a known gradient (in the second imaging direction), between initial excitation and signal acquisition. The value of this phase-encoding gradient is incremented from scan to scan. Thus signal acquisition may not occur immediately after excitation. In order to be acquiring at the moment when the spins are in phase, it is necessary to first apply a negative gradient (in the first imaging direction). This allows spins to dephase by a certain amount before signal acquisition commences. During acquisition, as the spins rephase, the signal intensity rises to a maximum and then decreases again as the spins continue to precess at different frequencies. This signal is called the echo. The fourier transform of this echo yields the frequency (and hence spatial) profile of the excitation.
When performing large flip angle gradient recalled echo experiments with slice selective pulses, a build up of transverse coherences occurs, causing transverse steady state artefacts in the resultant image, due to the formation of undesired spin echoes and stimulated echoes. The required T.sub.1 -dependence of the signal intensity is essentially destroyed by these extra signals.
Methods to "spoil", or destroy, these transverse coherences have employed variable addition gradient pulses or radio frequency methods in which successive pulses have little or no phase coherence. The former suffers not only because "extra" gradients can in fact refocus undesired coherences, but also as they introduce further eddy currents, which result in localised distortions in the magnetic field. Radio frequency methods in which phase coherence between successive pulses is removed are difficult to implement precisely and some transverse coherences persist and, in fact additional gradients are also required to prevent cancellation between the phase-encoding required in image formation and the phase offset supplied to remove coherence between pulses.
In accordance with one aspect of the present invention, a magnetic resonance experiment in which a sample under test is subjected to a sequence of gradient magnetic fields and radio frequency pulses and resultant pulse echoes are monitored is characterised in that at least one of the radio frequency pulses is a prefocused, phase-modulated, time-asymmetric radio frequency pulse.
In accordance with a second method of the present invention, apparatus for performing a magnetic resonance experiment comprises magnetic field generating means for subjecting a sample under test to a sequence of gradient magnetic fields; an RF pulse generator; and means for monitoring resultant pulse echoes and is characterised in that the RF pulse generator generates a prefocused, phase-modulated, time asymmetric RF pulse.

Magnetic resonance experiment and apparatus


Safety and sports equipment, as well as apparel and accessories, including one or more wire-like or flat electroluminescent lamps for illumination. The lamps may be powered by battery, solar energy, or any other suitable means of energy. The lamps may further be secured to an object, embedded within a rigid surface, or recessed within a material. The lamps may be either permanently, temporarily, or removably secured to the 6 object that is being illuminated.

This application claims the benefit of U.S. Provisional Application No. 60/109,517 filed on Nov. 23, 1998, which is incorporated by reference. The present invention generally relates to safety and sports equipment and accessories which are illuminated by electroluminescent phosphors arranged in an electroluminescent light source, particularly, a cable or wire-like light source, to enhance the appearance of the product and to improve visibility of the user. As increasingly more people are becoming health conscious, exercise and recreational activities are no longer just carried out during the daylight hours. Many sports activities are being conducted in low light, dusk, or dark surroundings. The present invention is intended to make sports enthusiasts more visible during these low light conditions.
In addition, rescue personnel and construction workers are required to perform duties during low light or no light conditions. Over the years, there have been efforts to render rescue personnel and construction workers visible during reduced visibility conditions. However, until now, an adequate solution has not been achieved.
Finally, efforts have been made to alert individuals of particular conditions using barriers, signs, wall barriers, cones, and barrels, for example. However, until now, there has not been an adequate solution for rendering these alerting devices visible during low light or no light conditions.
Previous methods for illuminating safety and sports equipment, as well as clothing and accessories, have included incorporating incandescent lamps, LEDs, and reflective materials into the various articles. However, these methods suffer from the following disadvantages.
Products and devices incorporating incandescent light bulbs and LEDs are typically bulky and relatively heavy as compared to their light emitting power. These conventional light sources are prone to fail because they are not shock proof or water proof. Incandescent lights and LEDs, to a lesser extent, produce heat that may become uncomfortable to wear when incorporated into a garment or used in a product proximate to a flammable solution, vapor or material. Similarly, incandescent lamps and LEDs have to be used with caution because they are large and tend to protrude from the surface of the product and may be easily damaged. In addition, LEDs illuminate a very small area that can only be viewed at a limited angle. Therefore, a large quantity of LEDs are required to achieve a large field of view.
Typically, because reflective material is not self-illuminating, it can only be seen when light impinges upon it. Reflective material is only as good as the light that it reflects, therefore, visibility resulting from reflective material is limited to a short distance.
Thus, there is a need for improved means for providing illumination to sports and safety equipment, as well as apparel and accessories.
Electroluminescent phosphors arranged in electroluminescent light sources or lamps have been developed in which the electroluminescent phosphor fibers emit light upon application of an alternating current to the fibers. Electroluminescent lamps have typically been arranged as a flat strip. However, a wire-like electroluminescent lamp has recently been developed, as described in U.S. Pat. No. 5,485,355, which is herein expressly incorporated by reference.
The wire-like electroluminescent light source includes at least two electrodes arranged to create an electric field between them upon application of a voltage, and at least one type of pulverulent electroluminophor dispersed in a dielectric binder and disposed proximate to the electrodes to emit light of a specific color(s) upon application of the voltage to the electrodes. A transparent sheath encases the electrodes and the electroluminophor.
The wire-like electroluminescent light source is flexible, shapeable and radiates light uniformly in all directions. The light source may be monochrome or polychrome, depending upon the type of electroluminophor powder(s) used.
The wire-like electroluminescent light source is completely UV resistant and waterproof. The phosphor fibers are durable, flexible, elastic, demand little power and are not harmful to the environment. The light sources do not generate heat, or harmful emissions. The wire-like electroluminescent light source is round and provides 360° of visibility without glare. The wire-like electroluminescent light source is capable of withstanding extreme weather conditions.

Marine craft and apparatus including electroluminescent auxiliary illumination


Fluoropolymer particles are subjected to high energy treatment so as to change the chemical functionality of the particle surfaces and thereby change the surface characteristics of the particles. These characteristics improve the usefulness of these particles and can make them highly dispersible, even in water. The surface treated fluoropolymer particles are subject to a chemical crosslinking process, or alternatively, are subject to a high energy treatment process, and may optionally be pretreated with a macromolecular chemical species prior to the foregoing processes. The high energy treatment can be used to both surface treat the fluoropolymer particles and in some embodiments, may also cause chain scission of the fluoropolymers to thereby reduce the molecular weight of the fluoropolymer particles. The surface treated fluoropolymer particles can be used to form fluoropolymer coatings on various substrates.

Fluoropolymers, are defined herein broadly as any of the fluorine containing polymers (or inert polymers), including homopolymers, copolymers, and terpolymers that have non-wettable and chemical inert surfaces which, although being desired in some applications, limit the use of these materials in other applications.
The technology of coating of articles with fluoropolymers has been developing along two fundamentally distinctive directions based on the physical form of powder and latex fluoropolymers. In each case, the final coating, which may be a continuous film layer, for example, is typically obtained by heating the applied fluoropolymers above their melting points.
Processes and products have been developed which provide specific advantages for powder and latex fluoropolymer applications. For technologies that use powdered fluoropolymers, modified polymer compositions and particle sizes and shapes have been developed to advance both the application yield (yield per pass) and the performance of the resulting film per unit film thickness. The major intrinsic obstacle to advancements in the use of powdered fluoropolymers is their poor electrical surface conductivity.
For latexes, the ultra low surface energy and the high specific gravity peculiar to fluoropolymers (they can be defined as being fully hydrophobic) has forced the adoption of different manufacturing technologies since the base polymer synthesis (e.g. dispersion) is characterized by polymer particles having an average diameter two orders of magnitude smaller than the powders, and by the extensive use of surfactants, both the fluorinated surfactants used during synthesis, and hydrogenated surfactants for the creaming of diluted dispersion obtained from the synthesis, and for the stabilization and formulation of concentrated latexes manageable by the application techniques (e.g. spray, roll, curtain coating). However, both kinds of surfactants, intrinsic to the technology, are detrimental to the coating application, negatively impacting the yield and the characteristics of the film layer (e.g. film continuity, adhesion to the substrate, etc.).
A way to escape from these two fundamental approaches is theoretically conceivable, and involves the modification of the fluoropolymer particle surface, to make it more compatible with the broad spectrum of available polar carrier means (e.g. water), but without altering/damaging the properties of the fluoropolymer bulk.
Surface treatments of fluoropolymer are known and established in the art. Fluoropolymers in the form of sheets, films and shaped articles have been chemically treated, subject to electrical discharged using corona discharge and plasmas, subject to flame treatment, and subject to physical treatment such as chemical adsorbing procedures. In each instance, desired results have often been less than satisfactory. For example, surface changes effected by chemical treatments produces darkening of the surface and chemical absorbing procedures are subject to deterioration and loss over time.
Flame treatments can cause undesired damage if not properly controlled.
Electrical treatments seem to have become the most accepted processes for desired long term effects. However, as discussed below, these treatment processes have limitations.
Corona discharge and flame treatment processes are used for treating the surfaces of films and other substrates such as foils, papers, etc. These treatment processes increase the surface energy of the substrates, which in turn improves the wettability, printability and adhesion on these surfaces. Corona discharges can produce locally concentrated discharges known as streamers. These streamers lead to some non-uniformity in the treatment of the film surfaces, and the concentrated energy of the streamers can also microscopically damage the film surface. Furthermore, corona treatment can produce backside treatment, which is undesirable in many applications.
Flame treatment also has limitations in terms of oxidation surface modification, difficulty in control and possibility of excessive thermal loads.
Plasma treatment is an effective method for treating surfaces to increase surface energy and improve wettability, printability and adhesion. Plasma produces uniform surface treatment without causing backside treatment of the substrate.
Low-pressure or atmospheric plasma treatment (APT) processes have been developed that provide unique advantages over existing technologies for surface treatment. The apparatus used in atmospheric plasma treatment does not require a vacuum system, produces a high-density plasma and provides treatment of various substrates at low temperature while operating at atmospheric pressure. The benefits of plasma treatment include reduced degradation of surface morphology, higher treatment (dyne) levels, elimination of backside treatment, and extended life over treatment time.
As reported by A. Yializis et al. (Atmospheric Plasma—The New Functional Treatment for Film, 2000 TAPPI Polymers, Laminations, & Coatings Conference pp. 1343-1352), atmospheric plasma treatment processes have been developed for treating continuous webs and films.

This patent is subject to a terminal disclaimer.

Method of treating fluoropolymer particles and the products thereof


An apparatus and method for ultraviolet irradiation of air for the purpose of removing contaminants from that air is disclosed. A U-shaped ultraviolet bulb enshrouded within a quartz tube provides enhanced contaminant destruction characteristics. By combining a plurality of those bulbs in a chamber that is of polished aluminum, and further combining aluminum filters therewith, added irradiation enhancement is achieved. Further provided are baffles or baffling proximate the ultraviolet bulbs that cause the air to go turbulent thus drawing the air closer to the ultraviolet bulb and further enhancing the contaminant destruction characteristics. Moreover disclosed is treatment of substrates with a chemical agent that facilitates the arrest of contaminants from the air onto the substrate for further irradiation of the contaminants from the bulbs. This further irradiation breaks down the arrested contaminants thus providing the substrate with a self-cleansing effect.

This invention relates generally to air cleansing devices. More particularly, this invention relates to ultraviolet (UV) irradiation and filtration devices. In particular, the invention deals with the use of ultraviolet radiation to decompose organic molecules that have a tendency to colonize filters and evaporation coils that are utilized to condition the air in enclosed surroundings. Also, the invention deals with the placement of ultraviolet lamps placed within a chamber that has a means for passing air therethrough. The chamber""s walls are polished and as such the UV radiation emitting from the UV lamps is reflected off the chamber walls which results in the decay of organic particles adjacent and within the surround and contained therein. Further, baffles adjacent the UV lamps in the chamber cause turbulence within the air passing therethrough which results in an increase in decay of the organic molecules.
Ultraviolet (UV) light in the form of germicidal lamps has been used since the early 1900""s to kill the same types of microorganisms that typically cause the same types of problems today. Since then, UV radiation in the short wave or C band range (UVC) has been used in a wide range of germicidal applications to destroy bacteria, mold, yeast and viruses. After World War II, the use of WVC rapidly increased. UVC is generally understood to exist in the 180 nm to 280 nm wave length area. Typical examples included hospitals, beverage production, meat storage and processing plants, bakeries, breweries, pharmaceutical production and animal laboratories; virtually anywhere microbial contamination was of concern. Early UVC strategies primarily consisted of an upper air approach. This method directed a beam across the ceiling of a room.
During the 1950""s when tuberculoses infections were on the rise, the use of UVC became a major component in the control and irradiation of TB. It was discovered that by placing UVC lamps in the air handling equipment, they could initially be more effective.
However, certain conditions found within the air handling systems drastically reduced UVC performance. Moving air, especially below 77xc2x0 F., over the tubes decreased the output and service life of conventional UVC products and thus their ability to destroy viable organisms. The use of UVC with airflow systems virtually disappeared over the next decade due to the introduction of new drugs, sterilizing cleaners and control procedures combined with the performance problems of UVC lamps and air handling systems (reduced output, short tube life, and high maintenance). In order for UVC to be effective in the xe2x80x9chostilexe2x80x9d environment of indoor central air circulating systems (or HVAC systems), a new method of producing effective UV had to be developed.
The ability of ultraviolet light to decompose organic molecules has been known for a long time, but it is only recently that UV cleaning of surfaces has been explored. In 1972, it was discovered that ultraviolet light could clean contaminated surfaces. Plus, it was learned that there is a predictable nanometer location of absorption of ozone and organic molecules. It was then learned that the combination of ozone and UV could clean surfaces up to two thousand times quicker than one or the other alone. However, from testing it can be seen that the destructive potential of a combination of UVC and ozone for system components is detrimental. The negative side effects of ozone are now known.
In 1972, tests were conducted using a quartz tube filled with oxygen. A medium pressure mercury (Hg) UV source which generated ozone was placed within centimeters of the tube. A several thousand angstrom thick polymer was exposed to this and was depolymerized in less than one hour. The major products of this reaction were water (H2O) and carbon dioxide (CO2). It was discovered that UV (300 nm and below) and oxygen played a major role in depolymerization. In 1974, research concluded that during such cleaning, the partial pressure of O2 decreased and that of CO2 and H2O increased, suggesting breakdown.
It was also discovered that the absorption coefficient of O2 increases rapidly below 200 nm with decreasing wave lengths. A 184.9 nm wave length (optimal spectral line for ozone generation) is readily absorbed by oxygen, thus leading to the generation of ozone (O3). Ozone may be generated at undetectable levels at other wave lengths below 200 nm. Therefore, radiation emission below 200 nm was found undesirable.
Similarly, most organic molecules have a strong absorption band between 200 nm and 300 nm. A wave length of 253.7 nm is useful for exciting and disassociating contaminant molecules. 265 nm was thought to be the optimal spectral line for germicidal effectiveness. The 253.7 nm wave length is not absorbed by O2; therefore, it does not contribute to ozone generation, but it is absorbed by most organic molecules and by ozone (O3). Thus, when both wave lengths are present, ozone is continually being formed and destroyed. Unfortunately, previously existing lamps operated between 250 nm and 258 nm, peaking at 254 nm, missing out on the optimal 265 nm goal.
As indicated above, the effective killing power of UV seemed to be greatest at 265 nm. However, conventional UV has its maximum intensity at 254 nm. Furthermore, the intensity degrades as a function of temperature and distance. This was due to the conventional tubes being designed as long, straight lamps.
With regard to HVAC systems, biological contaminants are difficult to control because they grow in our moist, indoor environment. The most common strategy is to try to use an effective air system filter to rid indoor air of biological contaminants. While this is an important element of cleaning air, this has its problems. Most filters are inadequate because of the many organisms that pass right on through the filter. Also, any organisms that collect on the filter can form germ colonies that may soon contaminate passing air. Further, if the filter should be too efficient, it blocks the passage of air and creates back pressure, causing the blower to struggle to move air through the system. Furthermore, when the system is turned off, natural temperature differences between the system and indoor air spaces cause convection or back draft flow into the supply ducts (bypassing the filter). This causes contaminants to be pulled back into the duct work, implanting microbes in the air flow duct cavity. These new cultures become added sources of contaminant.
In the past, to try to eliminate the biological contaminants in ducts, a common strategy was to clean the ducts followed by a biocide treatment. But this has its draw backs also. Most biological contaminants return and are active in the treated area within three months. Further, if the system is being treated for severe contamination such as legionela, an acid wash of the coil is common. This is not only expensive, but can shorten the life of the equipment. Furthermore, all biocide used in the ducts are chemical based, leaving potential toxic vapors and chemical pollutants circulating in the system as well. For obvious health reasons, the preferred way to control biological contaminants is through natural, non-polluting strategies.
The term xe2x80x9cair-conditioningxe2x80x9d (A/C) normally refers to cooling the air of a building. An A/C system operates like this: the outdoor portion of the A/C unit compresses a gas to a liquid. During this compression, heat energy is driven out of the liquid. This colder liquid then travels through tubing to the evaporative coil located inside the building proximate the central/furnace fan.
The evaporation coil has numerous rows of fins. The fins are all made of an aluminum alloy that is extremely tough due to an impervious film of oxide on the metal. The fins act as heat exchangers with the circulating air within the system. When this compressed liquid reaches the evaporative coil, the liquid expands and evaporates, converting back to a gas. As it does, it recovers the amount of heat energy lost in the compression cycle. This conversion absorbs heat through the coil fins from the surrounding air that is moving across the fins.
With the blower operating, air moves across the coil fins and is cooled by losing its heat to the evaporation process inside the coil.
If for some reason the central air system becomes less efficient during its operational life, the energy consumption and costs will rise. Since so much energy is involved just in normal use, any change in efficiency will mean a sharp increase in costs.
The evaporative coil is made of tiny, closely fitting fins for cooling the air. These fins are so close, the coil essentially becomes a filter, screening out and collecting dust particles from the air. Indoor airborne organic particles and microorganisms are primarily byproducts of human, animal, insect and microbial output (dead skin, hair, paint flakes, insect feces, carpet fibers, etc.) within the indoor environment. As these particles build up, the space between the fins becomes blocked, thus reducing airflow and restricting cooling efficiency of the coil.
The coil not only collects these particles, but also becomes a bio-nursery for mold and bacteria. When the A/C operates, water condenses onto the evaporative coil fins. This water drains off into a drip pan. Depending on the amount of moisture within the air, the amount of water collected and drained can be typically six gallons per day.
The evaporative coil is mounted in line to the furnace fan housing. Because of its location, the coil housing is very dark and moist. Thusly, it becomes an ideal nursery for the growth of bacteria and mold. Those skilled in the art consider the coil as the number one source of mold in homes.
At the coil, volumes of organic contaminates collect in two ways: (a) mold and bacteria growth in the damp coil produces sticky enzyme materials for trapping airborne organic material for food (this forms an activated crusty surface on the fins), and (b) the close fitting coil fins collect airborne particles much like a filter.
When the mold colonies grow on the coil, they produce a sticky substance called enzyme mycelium. Enzymes break down proteins and organic compounds. The enzyme mycelium performs two essential functions for molds: (a) the stickiness traps dust particles from the air, and (b) enzymes break the trapped particles into food.
With the dust and enzyme material collecting on the coil, an insulation film covers the fins. This installation prevents an efficient heat exchange between the air and fins and efficiency drops. With such restrictions, the cost of operating a coil can increase by 60%.
Thus, as can be seen, the coil then becomes a major source of airborne contamination (mold spores, enzymes, toxins and bacteria) due to the growth of mold, bacteria at the coil.
The following prior art reflects the state of the art of which applicant is aware and is included herewith to discharge applicant""s acknowledged duty to disclose relevant prior art. It is stipulated, however, that none of these references teach singly nor render obvious when considered in any conceivable combination the nexus of the instant invention as disclosed in greater detail hereinafter and as particularly claimed.
Nagy, et al., xe2x80x9cDisinfecting Air with Sterilizing Lampsxe2x80x9d, Heating, Piping and Air Conditioning, Vol. 26., Nos. 1-12, April 1954, pp. 82-87.
Steril-Air, Inc., xe2x80x9cSteril-Air UVC Emitters Product Brochurexe2x80x9d, date unknown, entire brochure.
Sterile-Air, Inc., xe2x80x9cGuide to UVC Emittersxe2x80x9d, date unknown, entire brochure.
Philips Lighting, xe2x80x9cDisinfection by UV-radiationxe2x80x9d, August, 1992, entire paper.
Westinghouse, xe2x80x9cSterilamp(copyright) Germicidal Ultraviolet Tubes Product Brochurexe2x80x9d, March, 1982, entire brochure.
Vig, xe2x80x9cUV/Ozone Cleaning of Surfaces, Treatise on Clean Surface Technology, Vol. 1, 1987, pp. 1-26.
Jensen, xe2x80x9cHVAC Technology is Weapon in Fight Against Tuberculosisxe2x80x9d, ASHRAE Journal, August, 1997, p. 12.
Georgia Tech Research Corporation, xe2x80x9cEmissions from Mold and Fungus May Cause Indoor Air Problemsxe2x80x9d, 1996, entire article.
Ward, xe2x80x9cIs Your Child Allergic to Schoolxe2x80x94Literally?xe2x80x9d, www.townonline.com, January, 1997, entire article.
Layton, xe2x80x9cAllergy and Attention Deficit Hyperactivity Disorder (ADHD)xe2x80x9d, www.allergyconnection.com, 1996, entire article.
Krajick, xe2x80x9cThe Floating Zooxe2x80x9d, Discover, February, 1997, pp. 66-73. Sacramento Municipal Utililty District, xe2x80x9cWater Water Everywhere, But . . . xe2x80x9d,On Center, Second Quarter, 1997, p. 1.
Bayer, et al., xe2x80x9cStudy Suggests Some VOCs Caused by Molds and Fungixe2x80x9d,ASHRAE Journal, October, 1996, p. 12.
An air cleaning apparatus is disclosed including UV lamps, aluminum filters, and a polished aluminum housing. The UV lamps include a U-bend crystal of quartz, ruby, or sapphire contained within a quartz sleeve. Useful substances for containment within the U-bend bulb are mercury, argon, gallium, iron, xenon or krypton. Between the sleeve and lamp, certain gases (nitrogen or atmospheric gases) are contained therein or the area is possibly evacuated. There are advantages and disadvantages to each. By using a mixture of above gases and/or by varying the electrical charge, one can increase the bandwidth to about 240 nm to about 280 nm, including the 265 nm optimum wave length. Further, increased electrical charge can increase bandwidth and spectral line output from 240 nm to 360 nm for more germicidal effect (UVC/UVB).
Polished aluminum filters and chamber walls are also included in this invention. The treated, polished aluminum alloy provides enhanced reflectivity for the UV rays to enhance the irradiation of particulate flowing through the filters and by the lamps. The aluminum filters have an additional special feature in that one side of the filter is of a coarse mesh whereas the other side of the filter is of a fine mesh. Air flow is from the coarse side to the fine side of one filter, past the UV bulbs, through the fine side, and out the coarse side of another aluminum filter and then back into the duct work of an HVAC system. By providing treated, polished aluminum surfaces surrounding the UV lamps, irradiation is enhanced significantly.
An alternate embodiment in the form of a portable air cleaning device is also described herein. The purpose of the portable device is to clean a single room with a similar system as described hereinabove, but also including a fan built into the portable unit to move through the system.
Another embodiment is described wherein a UV lamp array is mounted exterior to a compressor coil of an HVAC system thereby allowing for cleansing of contaminants contained on the coil and fin structure of the compressor. It has been known that this is a breeding ground for microorganisms and cleansing of this breeding ground will enhance cleansing of the entire HVAC system.
By inserting an UVC lamp into the coil region and adding a chemical catalyst, a process of organic xe2x80x9cdustingxe2x80x9d and microbial cleaning takes place at the coil. The process is further enhanced because the aluminum fins are excellent reflectors of the ultraviolet within the coil chamber resulting in UV amplification, with little or no deterioration on the metal itself.
As the air passes the WVC lamp, electrons of a dust, toxins, and microorganism molecules are ejected. Electrons are negative. When the electrons are ejected a positive particle or ion is left behind.
As the circulating air pass through the coil fins, the aluminum oxide fins pick up the charged organic and biological materials coming from the UV light area. The organic material adheres to the aluminum fins for several reasons.
The oxide film in the aluminum has a high propensity to collect electrons that generates an electrostatic polarity. This produces an affinity for either negative or positive ions (depending upon the pH) to the coil fins. Aluminum oxide has the highest advantage over all solid material because it is very stable over a wide range of pH. Normally the pH on the fin surface will be relatively high from the decay of organic materials on the fins, thus attracting positive ions to the coil.
The process on the aluminum oxide mesh is called electronegativity, which forms the basis of electrostatic energy on the filter surface. Electronegativity is based upon the principle of the power of an atom in a molecule to attract elections to itself. The electronegativity of an element depends upon its valence state. Aluminum has an average electronegativity value of 1.61 (near the middle compared to the other element values in the group); oxygen has the second highest value of all elements to attract electrons to itself at 3.44. All coil fins are made of aluminum oxide metal, thus having a very high attraction ability of free electrons to the fins, primarily due to the strength of the oxide (oxygen) to attract elections.
The aluminum oxide fins have an enormous capacity to attract an abundance of free electrons stripped by the UV from the incoming organic and biological particles before getting to the coil. As the aluminum oxide collects more and more electrons, the coil loads up on electrons, becoming primarily negative.
And as the positively charged organic ion material (coming from the UV light area) nears the negatively charged coil, the organic molecules begin adhering to the fins based upon the principle of positive/negative polarity (the electrostatic principle). In other words, the incoming airborne positively charged organic materials are attracted to the negatively charged coil and adhere to the coil fins.
With the dust adhering to the coil fins, the UVC can then begin the breakdown process. The invention then has two methods of breaking apart the hydrocarbon contaminates.
The damaging effects of x-ray and gamma ray radiation are recognized but not fully understood. X-ray, gamma, ultraviolet, infrared and visible light energy fit in a category called electromagnetic energy. They all have the same characteristic of an oscillating energy wave that travels at the speed of light. The difference in each type of wave energy is the wavelength or the distance across the wave. The shorter the distance across the wave body, the shorter the wavelength and the stronger the energy. It is this wavelength difference that results in short-wave x-ray passing through walls, while longer wave lengths of visible light cannot. Short-wave ultraviolet and x-ray can destroy DNA in living microorganisms and break down organic material while visible light cannot.
The science of ultraviolet radiation usage is essentially the science of photochemistry. Photochemistry is defined as a chemical reaction or change in a material induced by the radiation of light energy.
The photochemical process takes place when electrons of a molecule are ejected or changed by the irradiation of light energy, leaving an incomplete and decaying molecule. With the absence of an electron, organic compounds become unstable and fall apart.
All organic particles and microorganisms have a strong reaction to light energy between 180-320 nm. Such molecules are vulnerable to short-wave UV irradiation. The reason: molecular structures depend upon the continued maintenance of a molecular weight. But this weight is altered when UV irradiation reduces the number of electrons orbiting an organic molecule. This causes decay of the material.
Ultraviolet radiation in the C-band (WVC) has properties that alter the cells of living tissue, particularly microbes due to size. WVC radiation ejects electrons and alters the bonds between amino acids in the microbe""s DNA molecules. This renders bacteria, viruses and molds sterile. The cell structure of microbes will continue to degrade in the presence of short-wave UV and will break down into free state ions and/or separate carbon or hydrogen molecules.
One of the reactions is the formation of hydrogen peroxide (H2O2) from the photochemical change of the dust, toxins and microorganism collecting at the coil. When the UV changes molecular electrons of the organic material often hydrogen is ejected from the molecules of the material. These hydrogen radicals then react with ordinary atmospheric oxygen (O2), forming hydrogen peroxide H2O2. The hydrogen peroxide process activates a chain reaction, oxidizing organic material and helping to clean coil surfaces.
Further, the hydrogen peroxide is also converted to hydroxide (OHxe2x80x94), which is a very powerful oxidizing agent.
At the factory or before the coil is installed, the evaporative coil fins are sprayed with a liquid mixture of water and sodium persulfate (Na2S2O8), or potassium persulfate (K2S2O8) or sodium hydroxide (NaOH). These liquid mixtures dry at room temperature on the surface of the coil fins, leaving a residue of the persulfates or sodium hydroxide.
The persulfates, when exposed to UV at wavelengths 100 nm to 320 nm, forms hydrogen peroxide (H2O2). Hydrogen peroxide, however, quickly breaks down into hydroxide (OH) and water (H2O) when exposed to these UV wavelengths.
Under the alternative, the sodium hydroxide, when exposed to short wave ultraviolet, breaks down into sodium (Na) and hydroxide (OH).
The dried crystals of persulfates within the coil fins, when exposed to UV form by products including hydrogen sulfate and hydrogen peroxide (S2O8xe2x88x922+2H2O+UV=2HSO4xe2x88x92+H2O2). The hydrogen peroxide (H2O2) both hydroxide (OH) and water in the presence of UV (H2O2+UV=H2O+OH).
The hydroxide formation is from the UV and persulfates (persulfates to hydrogen peroxides converting to hydroxide in the presence of short wave to medium wave UV) or the sodium hydroxide that have been sprayed on the coil fins. In either case hydroxide is formed in the presence of UV.
Hydroxide is a stable but a very potent one-electron oxidant. The reason hydroxyl ions are so destructive to organic molecules (house dust, toxins and microorganism) is the hydroxide ions xe2x80x9ccapturexe2x80x9d hydrogen molecules from the organic materials, leaving decayed carbon ions. The removal of hydrogen from organic molecules by hydroxide forms even stronger reactive OH bonds as the result of the water at the coil. The process turns into a chain reaction, resulting in continual decay of the organic material by hydroxide formation and converting back to water.
Hydroxide primarily targets organic materials for oxidation. This oxidizing agent thrives by absorbing hydrogen from organic compounds. Hydroxide is perhaps the ideal oxidizer for cleaning organic growth in the evaporation coil without the corrosive effects of ozone. A damp coil is the best environment to experience the full effects of UV. It is in this promising condition that UV energy breaks down the collected organic material, setting off a chain reaction of hydroxide and hydroperoxide formation, which further destroys organic materials.
This means the invention effectively cleans the evaporation coil of organic particle collection and destroys any growth of germs and mold accumulating at the coil. Once clean, the coil remains clean in the presence of the invention.
Accordingly, it is a primary object of the present invention to provide an ultraviolet ray actinism chamber for destroying contaminants thereby.
Another object of the present invention is to avoid the production of ozone in such a system.
Another object of the present invention is to provide increased UV bandwidth to so increase the xe2x80x9ckillingxe2x80x9d power of the UV system.
Another object of the present invention is to maintain a substantially constant temperature around the UV bulb.
Another object of the present invention is to increase UV reflectivity in and around the UV bulbs to enhance the UV irradiation.
Another object of the present invention is to provide self cleaning filters for a UV system.
Another object of the present invention is to provide better, yet shorter lamp lengths to fit in conventional HVAC systems.
Yet another object of the present invention is to enhance the bulb life of a UV bulb for such a system.
Viewed from a first vantage point, it is an object of the present invention to provide an apparatus for purging impurities from ambient air conditions, comprising: a source of radiation in operative communication with the ambient air conditions; and a coating upon which radiation emitted from said source impinges thereon facilitating a chemical reaction.
Viewed from a second vantage point, it is an object of the present invention to provide an a method for purging impurities from ambient air conditions, comprising the steps of: creating turbulent air around an ultraviolet light source; passing the turbulent air adjacent to the ultraviolet light source to create a photochemical reaction.
Viewed from a third vantage point, it is an object of the present invention to provide a self-cleansing filter or evaporative coil prepared by a process comprising the steps of: coating a substrate with a mixture of water and sodium hydroxide or a persulfate; drying the mixture coated in the substrate at room temperature leaving a residue of the persulfate or sodium hydroxide
Viewed from a fourth vantage point, it is an object of the present invention to provide a chamber for cleansing ambient air, comprising, in combination: an air inlet; an air outlet; said chamber interposed and communicating between said inlet and outlet; a source of radiation in said chamber, said chamber imperforate to the radiation; said chamber having an interior surface with means for reflecting substantially all the radiation; and a coating means to enhance the effect of the radiation.
Viewed from a fifth vantage point, it is an object of the present invention to provide a method for coating a filter mesh or an evaporative coil for providing either negative or positive ions depending upon the pH or pOH, the steps comprising: forming a filter mesh or evaporation coil out of aluminum; dipping or spraying the filter mesh or evaporation coil with a liquid mixture to form a film; wherein the liquid mixture is selected from the group consisting of water and sodium persulfate, potassium persulfate and sodium hydroxide.
Viewed from a sixth vantage point, it is an object of the present invention to provide an method of photochemically treating ambient air to purge impurities, the steps comprising: filtering the air; exposing the air to a source of radiation; further filtering the air after exposure to radiation to arrest irradiated particles within the air after irradiation; and further exposing the arrested, irradiated particles to further radiation causing a break down of the molecular structure of said irradiated particles that yields a self-cleansing effect to a structure to which the arrested, irradiated particles were arrested by.
Viewed from a seventh vantage point, it is an object of the present invention to provide a method of treating air with a chemical disposed on an aluminum substrate, the steps comprising: passing air through the aluminum substrate in order to arrest particles or organic molecules; exposing the particles or organic molecules to radiation to cause breakdown of the molecular structure in order to remove particles or organic molecules from the aluminum substrate thus providing a self-cleansing effect.

Air actinism chamber apparatus and method


An anti-shake apparatus for image stabilizing of a photographing apparatus comprises a movable unit and a controller. The controller controls the movement of the movable unit for anti-shake operation. The controller controls the movement of the movable unit such as to hold the movable unit at a position without performing the anti-shake operation, for a specified time period that is a part of the time period from the point when the exposure time of the photographing apparatus is finished to the point when the photographing apparatus is set to a state where the next imaging operation can be performed. The position is the initial position where the movable unit is located when the specified time period commences.

1. Field of the Invention
The present invention relates to an anti-shake apparatus for a photographing apparatus, and in particular to the control of movement of the movable unit after the time period during which the anti-shake operation cannot be performed correctly is finished.
2. Description of the Related Art
An anti-shake apparatus (an image stabilizing apparatus) for a photographing apparatus is proposed. The anti-shake apparatus corrects for the hand-shake effect by moving a hand-shake correcting lens or an imaging device on a plane that is perpendicular to the optical axis, corresponding to the amount of hand-shake which occurs during imaging.
Japanese unexamined patent publication (KOKAI) No. H07-261233 discloses an anti-shake apparatus that performs an interruption process for the anti-shake operation at a constant sampling cycle.
However, in this anti-shake apparatus, a case exists where the anti-shake operation controlled by the controller (such as the CPU etc.) cannot be performed at the constant sampling cycle, in other words, the anti-shake operation cannot be performed for part of or more than one sampling cycle, for example, when communication between the controller and the image processing unit (such as a DSP etc.) is being performed etc.
When the anti-shake operation cannot be performed for part of or more than one sampling cycle, a case may exist where the movable unit cannot be moved to the correct position to continue the anti-shake operation in the next-cycle (in other words, the movable unit 30a is moved to a position far from the correct position).
In the case of this occurrence, the movable unit is moved to the correct position to continue the anti-shake operation when the communication between the controller and the image processing unit has finished, in order that the anti-shake operation can be performed in the next predetermined time interval (sampling cycle).
However, if the distance required to move the movable unit to the correct position is far, the movable unit is suddenly transported to the correct position and the shock from braking when the movement to the correct position is finished becomes large enough that the possibility an oscillation exists. If the shock from the braking is large, the operator of the photographing apparatus may experience discomfort due to oscillation or shock of the movable unit.


A dry preunit (10), includes a plurality of cells (110, 112, 114) in a true bipolar configuration, which are stacked and bonded together, to impart to the device an integral and unitary construction. Each cell (114) includes two electrically conductive electrodes (111A, 111B) that are spaced apart by a predetermined distance. The cell (114) also includes two identical dielectric gaskets (121, 123) that are interposed, in registration with each other, between the electrodes (111A, 111B), for separating and electrically insulating these electrodes. When the electrodes (111A, 111B), and the gaskets (121, 123) are bonded together, at least one fill gap (130) is formed for each cell. Each cell (114) also includes a porous and conductive coating layer (119, 120) that is formed on one surface of each electrode. The coating layer (119) includes a set of closely spaced-apart peripheral microprotrusions (125), and a set of distally spaced-apart central microprotrusions (127). These microprotrusions (125, 127) impart structural support to the cells, and provide additional insulation between the electrodes. An energy storage device (10A) such as a capacitor, is created with the addition of an electrolyte to the gap (130) of the dry preunit (10) and subsequent sealing of the fill ports.

1. Field of the Invention
The present invention generally relates to an energy storage device, and more particularly to a bipolar double layer capacitor-type energy storage device, and to methods for manufacturing the same.
2. Description of the Related Art
Energy Storage Devices--There has been significant research over the years, relating to useful reliable electrical storage devices, such as a capacitor or a battery. Large energy storage capabilities are common for batteries; however, batteries also display low power densities. In contrast, electrolytic capacitors possess very high power densities and a limited energy density. Further, carbon based electrode double-layer capacitors have a large energy density; but, due to their high equivalent series resistance (ESR), have low power capabilities. It would therefore be highly desirable to have an electrical storage device that has both a high energy density and a high power density.
A recent review by B. E. Conway in J. Electrochem. Soc., vol. 138 (#6), p. 1539 (June 1991) discusses the transition from "supercapacitor" to "battery" in electrochemical energy storage, and identifies performance characteristics of various capacitor devices.
D. Craig, Canadian Patent No. 1,196,683, in November 1985, discusses the usefulness of electric storage devices based on ceramic-oxide coated electrodes and pseudo-capacitance. However, attempts to utilize this disclosure have resulted in capacitors which have inconsistent electrical properties and which are often unreliable. These devices cannot be charged to 1.0 V per cell, and have large, unsatisfactory leakage currents. Furthermore, these devices have a very low cycle life. In addition, the disclosed packaging is inefficient.
M. Matroka and R. Hackbart, U.S. Pat. No. 5,121,288, discusses a capacitive power supply based on the Craig patent which is not enabling for the present invention. A capacitor configuration as a power supply for a radiotelephone is taught; however, no enabling disclosure for the capacitor is taught.
J. Kalenowsky, U.S. Pat. No. 5,063,340, discusses a capacitive power supply having a charge equalization circuit. This circuit allows a multicell capacitor to be charged without overcharging the individual cells. The present invention does not require a charge equalization circuit to fully charge a multicell stack configuration without overcharging an intermediate cell.
H. Lee, et al. in IEEE Transactions on Magnetics, Vol. 25 (#1), p. 324 (January 1989), and G. Bullard, et al., in IEEE Transactions on Magnetics, Vol. 25 (#1) p. 102 (January 1989) discuss the pulse power characteristics of high-energy ceramic-oxide based double-layer capacitors. In this reference various performance characteristics are discussed, with no enabling discussion of the construction methodology. The present invention provides a more reliable device with more efficient packaging.
Carbon electrode based double-layer capacitors have been extensively developed based on the original work of Rightmire, U.S. Pat. No. 3,288,641. A. Yoshida et al., in IEEE Transactions on Components, Hybrids and Manufacturing Technology, Vol. CHMT-10, #1,P-100-103 (March 1987) discusses an electric double-layer capacitor composed of activated carbon fiber electrodes and a nonaqueous electrolyte. In addition, the packaging of this double-layer capacitor is revealed. This device is on the order of 0.4-1 cc in volume with an energy storage capability of around 1-10 J/cc.
T. Suzuki, et al., in NEC Research and Development, No. 82, pp. 118-123, July 1986, discloses improved self-discharge characteristics of the carbon electric double-layer capacitor with the use of porous separator material on the order 0.004 inches thick. An inherent problem of carbon based electrodes is the low conductivity of the material resulting in a low current density being delivered from these devices. A second difficulty is that the construction of multicell stacks is not done in a true bipolar electrode configuration. These difficulties result in inefficient packaging and lower energy and power density values.
Additional references of interest include, for example:
The state of solid state micro power sources is reviewed by S. Sekido in Solid State lonics, vol. 9, 10, pp. 777-782 (1983).
M. Pham-Thi et al. in the Journal of Materials Science Letters, vol. 5, p. 415 (1986) discusses the percolation threshold and interface optimization in carbon based solid electrolyte double-layer capacitors.
Various disclosures discuss the fabrication of oxide coated electrodes and the application of these electrodes in the chlor-alkali industry for the electrochemical generation of chlorine. See for example: V. Hock, et al. U.S. Pat. No. 5,055,169 issued Oct. 8, 1991; H. Beer U.S. Pat. No. 4,052,271 issued Oct. 4, 1977; and A. Martinsons, et al. U.S. Pat. No. 3,562,008 issued Feb. 9, 1971. These electrodes, however, in general do not have the high surface areas required for an efficient double-layer capacitor electrode.
It would be useful to have a reliable long-term electrical storage device, and improved methods to produce the same. It would also be desirable to have an improved energy storage device with energy densities of at least 20-90 J/cc.
Packaging of Energy Storage Devices--As mentioned above, there has been significant research over the years regarding electrical storage devices of high energy and power density. The efficient packaging of the active materials, with minimum wasted volume, is important in reaching these goals. The space separating two electrodes in a capacitor or a battery is necessary to electrically insulate the two electrodes. However, for efficient packaging, this space or gap should be a minimum. It would therefore be highly desirable to have a method to create a space separator or gap that is substantially uniform and of small dimension (less than 5 mil (0.0127 cm).
A common way to maintain separation between electrodes in an electrical storage device with an electrolyte present (such as a battery or capacitor) is by use of an ion permeable electrically insulating porous membrane. This membrane is commonly placed between the electrodes and maintains the required space separation between the two electrodes. Porous separator material, such as paper or glass, is useful for this application and is used in aluminum electrolytic and double layer capacitors. However, for dimensions below 1 or 2 mil (0.00254 to 0.00508 cm) in separation, material handling is difficult and material strength of the capacitor is usually very low. In addition, the open cross-sectional areas typical of these porous membrane separators are on the order of 50-70%.
Polymeric ion permeable porous separators have been used in carbon double layer capacitors as discussed by Sanada et al. in IEEE, pp. 224-230, 1982, and by Suzuki et al. in NEC Research and Development, No. 82, pp. 118-123, July 1986. These type of separators suffer from the problem of a small open area which leads to increased electrical resistance.
A method of using photoresist to fill voids of an electrically insulating layer to prevent electrical contact between two electrode layers for use as a solar cell is disclosed by J. Wilfried in U.S. Pat. No. 4,774,193, issued Sep. 27, 1988.
A process of creating an electrolytic capacitor with a thin spacer using a photosensitive polymer resin solution is disclosed by Maruyama et al in U.S. Pat. No. 4,764,181 issued Aug. 16, 1988. The use of solution application methods described with a porous double-layer capacitor electrode would result in the undesirable filling of the porous electrode.
Additional references of general interest include U.S. Pat. No. 3,718,551; 4,816,356; 4,052,271; 5,055,169; 5,062,025; 5,085,955; 5,141,828; and 5,268,006.
All of the applications, patents, articles, references, standards, etc. cited in this application are incorporated herein by reference in their entirety.
In view of the above, it would be very useful to have one or more methods to produce a reliable small space separation between electrodes in electrical storage devices with a large open cross-sectional area. The present provides these methods.


A magnetic tape drive having a motor with a magnetically shielded cavity or hole in one cover of the motor providing additional room for movement of a magnetic head. The cavity eliminates a mechanical interference problem, enabling direct drive of a roller (puck) combined with short overall drive height. In motors having an internal stator, some of the stator poles are eliminated and a magnetically shielded cavity is provided in the area where the stator poles are eliminated. In motors having an external stator, no stator modification is required and a shielded cavity provides access into an open area of the rotor. In addition, for motors having an external stator and sufficient magnetic shielding, a simple hole in one cover of the motor may be sufficient rather than a magnetically shielded cavity.

In 1972, a belt driven tape cartridge design (U.S. Pat. No. 3,692,255, issued to Robert A. Von Behren) was introduced for use in the computer industry for digital tape recording. Cartridges commonly in use in 1972 were approximately 100 mm by 150 mm and the magnetic tape was 6.35 mm (0.250 inches) wide. Cartridges of that size and corresponding drive mechanisms are still commercially available. In 1976, smaller data cartridges were developed, as described by Alan J. Richards, Mini Data Cartridge: A Convincing Alternative for Low-Cost, Removeable Storage, Hewlett-Packard Journal, May, 1976. The mini-cartridge size is 63.5 mm by 82.5 mm. Versions of the mini-cartridge are commercially available from a variety of vendors with tape widths varying from 3.81 mm (0.150 inches) to 6.35 mm (0.250 inches). New versions of mini-cartridges have been proposed having a tape width of 8.00 mm (0.315 inches). The external dimensions of the proposed cartridges are identical to existing mini-cartridges but there are numerous internal changes to accommodate wider tape.
Both sizes of cartridges described above have two openings in one edgewall. The first opening provides access to the tape by a magnetic head. The magnetic head travels across the width of the tape, transverse to the direction of tape movement, accessing one track at a time for reading or writing. The second opening provides access to a driven roller (capstan) inside the cartridge by an external driving roller (puck) in the drive mechanism. The external driving roller (puck) is rotated by a motor in the drive mechanism. In full height drives and half-height drives, the external driving roller (puck) is typically driven directly by the drive motor. As drive height decreases, there may be a mechanical interference between the drive motor and the magnetic head. The interference problem is made even worse with the proposed cartridges having a tape width of 8.00 mm (0.315 inches), increasing the distance the magnetic head has to travel. Therefore, in newer shorter height drives, the drive motor is typically displaced relative to the driving roller (puck) and connected to the driving roller (puck) by a belt or an intermediate roller. For example, see U.S. Pat. No. 5,210,664 issued to Mark W. Perona on May 11, 1993. Belts and intermediate rollers add cost and may slip or cause other speed problems. A direct drive is desirable as the lowest cost and most reliable way of connecting the drive motor to the driving roller (puck). A drive mechanism is needed that has both a directly driven roller (puck) and room for full movement of the magnetic head.

Magnetic tape drive having direct drive motor and extended head travel


A raster image memory which serves as a bit-map memory for the storage of the bit representation of a whole page to be printed for a raster output scanner is connected to a raster image processor by a synchronous raster image bus having a number of data and modification code lines. Each memory element of the bit-map memory corresponds to a position on the page. The raster image processor fills the raster image memory. A logic processing unit is disposed between the raster image bus and the bit-map memory so that one input of the logic processing unit is connected to the data lines of the raster image bus and another input of the logic processing unit is connected to the data outputs of the bit-map memory. The logic processing unit is also capable of performing a number of logic operations on the data presented at the inputs of the logic processing unit in response to the signals on the modification code lines.

Front-end systems using raster image memories for storing page data are known and used. Generally, they are used in printers which are capable of printing a complete page line-wise with serially presented data compared with on-the-fly systems, e.g., U.S. Pat. No. 4,031,519. A typical printer for complete page printing is the laser printer in which a light beam is modulated imagewise and deflected line-wise by means of a polygonal mirror over a light-sensitive surface. The latent image produced on the surface by the modulated light beam can be developed in a known manner and transferred to a receiving material such as a sheet of paper.
Graphical data, for example, may be obtained by scanning an image by means of a scanning device and storing the data, with or without the aid of a coding system, in a memory. The data for a page to be printed is first processed, for example by means of a graphical work station, to produce a finally desired layout which may contain textual and graphical data. If an assembled page has to be printed, the graphical information, coded or not coded, and the coded font data are fed to the front-end system along with information relating to height, width and finally desired position. In addition, the bit-map information of the characters to be printed is fed to the front end.
After the front end has stored all of the data in memory, it is necessary to set this data at the correct location in a page-size raster image memory or bit-map memory. The raster image memory is then serially read out and the data are fed to the modulator of the laser printer.
In the raster image memory, the bit representation of type characters and graphical characters is stored at a location which corresponds to the position which the character will finally attain on the printed page. Because modern laser printers are capable of printing pages at high speed and high resolution, the front-end system has to be capable of processing the data pages at high speed for presentation to the printer. For this purpose, the raster image memory will also have to fulfill the requirement imposed above. Accordingly, it is an object of the present invention to provide a raster image memory which can process the data needed for high-resolution printers at high speed.


Connector apparatus electrically connects together a plurality of shielded cables, including a housing containing a chamber including a first opening for receiving one end of a first shielded cable, and at least two second openings receiving the one ends of at least two second shielded cables, respectively. A conductive shield associated with the housing connects together the shielding layers of all of the cables, and a printed circuit board arranged in the housing connects at least one conductor of at least two of the second cables with a corresponding conductor of the first cable.

1. Field of the Invention
Connector apparatus electrically connects together a plurality of shielded cables, including a housing containing a chamber including a first opening for receiving one end of a first shielded cable, and at least two second openings receiving the one ends of at least two second shielded cables, respectively. A conductive shield associated with the housing connects together the shielding layers of all of the cables, and a printed circuit board arranged in the housing connects at least one conductor of at least two of the second cables with a corresponding conductor of the first cable.
2. Description of Related Art
In the field of automation techniques, one repeatedly encounters the problem with cables having patch connectors using the so-called M-standard (i.e., M8 or M12 standard), of making suitable twin or T-shaped connections. Currently, the solutions to these problems include: (a) the use of commonly manufactures patch connectors with a cable screw connection having two inputs, (b) a T-piece connection without cable and having three plugs, and (c) one line where two cables come out of one plug. These solutions work well for unshielded electrical cables, but they are not suitable for shielded cables because the cable shields cannot readily be placed twice on a single plug.
The present invention was developed to provide an improved T-type connection for shielded cables.


A plasmonic phase modulator is provided. The modulator has a conductive layer, and a dielectric layer disposed on the conductive layer. A plasmonic layer is disposed on the dielectric layer. A plasmonic layer is disposed on the dielectric layer. The plasmonic layer is conductive to surface plasmon polariton (SPP) waves. The plasmonic layer may be, for example, a graphene sheet. A voltage signal source is operatively connected between the conductive layer and the plasmonic layer for modulating a propagation speed of an SPP wave propagating on the plasmonic layer.

Wireless data rates have doubled every eighteen months for the last three decades. Following this trend, Terabit-per-second (Tbps) links are expected to become a reality within the next five years. The limited available bandwidth for communication systems in the microwave frequency range motivates the exploration of higher frequency bands for communication. In this direction, millimeter wave (mm-wave) communication systems, such as those at 60 GHz, have been heavily explored in the last decade. However, despite their much higher operation frequency, the available bandwidth for communication is less than 10 GHz. This would require the use of communication schemes able to provide a spectral efficiency in the order of 100 bits/second/Hz to support 1 Tbps, which is several times above the state-of-the-art for wireless communication.
In this context, the Terahertz band (0.1-10 THz) is envisioned as a key player to satisfy the need for much higher wireless data rates. Despite the absorption from water vapor molecules, the THz band supports very large transmission bandwidths, which range from almost 10 THz for communication distances below one meter, to multiple transmission windows, each of them tens to hundreds of GHz wide, for distances in the order of tens of meters. Traditionally, the lack of compact and efficient THz signal sources and detectors, able to operate at room temperature, has limited the use of the THz band. However, major progress in the last decade is finally helping to close the THz gap.
In addition to THz signal sources and detectors, a modulator is needed to embed information on the transmitted signals. The desired properties of a modulator include high modulation bandwidth, i.e., the speed at which the properties of the modulated signal can be changed, and high modulation depth, i.e., the maximum difference between modulation states. Different types of modulators able to control the amplitude or phase of THz waves have been developed to date. A high-electron-mobility transistor based on a III-V semiconductor material was utilized to modulate the amplitude of a THz wave. In another work, a metamaterial-based modulator was utilized to control the phase of a THz wave. In both cases, sub-GHz modulation bandwidths and low modulation depths limited the use of these devices in practical communication systems.
More recently, the use of graphene to develop THz wave modulators has been proposed. Graphene has excellent electrical conductivity, making it very well suited for propagating extremely-high-frequency electrical signals. A graphene-based amplitude modulator for THz waves was developed. This was enabled by the possibility to dynamically control the conductivity of graphene. In another work, a similar principle was exploited in a graphene-based meta-device. In these setups, the main challenge was to increase the modulation depth. A low modulation depth makes the transmitted symbols more difficult to distinguish and, thus, results in higher symbol error rates (SER) in practical communication systems.

Plasmonic phase modulator and method of modulating an SPP wave

The Research Foundation for The State University New York


A gas system has a first compressor stage for compressing a process gas. The first compressor stage includes an intake side and a pressure side. A seal gas is provided outside the first compressor stage in order to prevent process gas from issuing from leaks in the first compressor stage, having at least one second line for returning a gas mixture issuing from the gas system, this mixture including at least of process gas and seal gas. The at least one second line is configured for returning the issuing gas mixture to the intake side of the first compressor stage and/or to a location in the gas system upstream of the first compressor stage.

Gas systems for compressing process gas are widely used in industry. In such circumstances, for example in the case of separating CO2 from the exhaust gas of combustion processes, a plurality of compressors or compressor stages are arranged in series, wherein the intake side of each successive compressor stage is connected to the pressure side of the preceding compressor stage. As a result, greater compression can be achieved than with only one compressor stage. Cooling units, such as for example heat exchangers, can be arranged in the gas system between the individual compressor stages, in order to cool the flow of gas—which has a raised temperature after compression—again before the next compression stage. However, highly compressed process gas also makes high demands on the gas tightness of the gas system. Points where a shaft, to which the compressor rotors are attached, passes through the pressure-bearing housing enclosing the rotors are possible sources of leakage. The process gas issuing from this leakage source is captured and fed back into the flow of gas in the gas system. In so doing, care must be taken to ensure that the pressure of the captured process gas from the leakage is greater than the pressure of the process gas at that location of the gas system where the captured process gas is fed back into the gas system. In order to further minimize leaks in this region, the outer spaces around the shaft passages are enclosed by a further housing inside which is a seal gas. N2 or air can for example be used as seal gas in this context. This seal gas is under such a high pressure that it is impossible for the process gas to flow out through the shaft passages. However, it can be advantageous not to entirely prevent the leakage of process gas at the shaft passages. It is known to capture the mixture of seal gas and process gas. The captured mixture is then released into the environment or, if for example the process gas and/or the seal gas is toxic and/or flammable, is disposed of in a separate process. The process gas contained in the gas mixture is thereby lost.

Gas system for compressing a process gas