A baffleless tube and shell heat exchanger for cooling a liquid, comprising a shell having an inlet and an outlet; a plurality of tubes longitudinally disposed in the shell, each of the tubes having an inlet and an outlet for passing a coolant therethrough, the liquid to be cooled passing through the shell along the exterior of the tubes, the interior and exterior circumference of the tubes being fluted substantially along the entire length thereof such that the coolant flows substantially longitudinally through the tubes in a spiralled manner and the liquid passes substantially longitudinally through the shell in a spiralled manner; and support means for supporting the tubes wherein the flow of the liquid through the heat exchanger only experiences restriction due to the tubes and the support means, there being no baffles to restrict the flow.

Shell and tube heat exchangers have been commonly used as the evaporator component for industrial air conditioning and refrigeration systems. A common usage of such systems is for chilling ocean water for storage and preservation of fish.
In such a system, in a vapor compression cycle, a liquified refrigerant is metered by a thermal expansion valve into the lower pressure environment of the heat exchanger. In the heat exchanger, the refrigerant changes phases from a liquid to a vapor as it absorbs the required heat from the liquid to be cooled. A compressor withdraws the refrigerant vapor from the heat exchanger, raises its pressure and discharges the refrigerant into the condenser, where the heat absorbed in the evaporator is discarded to the heat sink as the refrigerant changes phase from a vapor to a liquid. The higher pressure liquid is then ready for another cycle.
A common type of heat exchanger is a shell and tube heat exchanger which includes a shell having a plurality of tubes disposed therein. Refrigerant flows through the tubes while the fluid to be cooled flows through the shell, externally to the tubes and in contact therewith. As the refrigerant passes through the tubes it evaporates, absorbing heat from the fluid being cooled.
Laminar fluid flow through and along the exterior surface of the tubes is undesirable as it creates an insulating boundary layer contacting the tubes, thereby decreasing the amount of heat that is transferred from the fluid to the refrigerant. To overcome this problem, conventional tube and shell heat exchangers have utilized baffles spaced along the length of the shell and oriented so as to direct the fluid flow substantially along a sinusoidal path such that the fluid flows across the tubes thereby creating turbulence. For instance, U.S. Pat. No. 4,699,211, issued to Geary et al., and U.S. Pat. No. 4,118,944, issued to Lord et. al., disclose a shell and tube heat exchanger having a plurality of baffles spaced along the length of the shell for the purpose of creating a wave-like flow therethrough.
The problem associated with these conventional baffled shell and tube heat exchangers is that the velocity of the fluid passing through the heat exchanger is variable, increasing as it passes by the baffles and decreasing between the baffles. Since heat exchangers are designed for specific flow rates, the changing flow rate associated with a baffled heat exchanger makes the design less efficient. In particular, a baffled heat exchanger must be designed to accommodate the higher flow rates associated with the fluid passing by the baffles. Therefore, the flow rate of the fluid is often below the optimum flow rate for which the heat exchanger is designed. Moreover, the baffle design requires that the tubing be spaced relatively far apart in order to allow adequate fluid flow by the baffles. Another design for accommodating fluid flow by the baffles is to not include tubing proximate the baffles, resulting in portions of the heat exchanger having no tubing, and, therefore, no heat exchange. Each of these designs results in a relatively large heat exchanger.
A further disadvantage associated with a baffled heat exchanger is that the fluid flow in the areas adjacent the baffles is relatively stagnant. Therefore, when ocean water or other contaminated fluid is being cooled, these portions of the heat exchanger become contaminated, thereby reducing the efficiency of the baffled heat exchanger.

Baffleless tube and shell heat exchanger having fluted tubes


A volumeter, in particular for use in liquid chromatography comprises a metering chamber for the volume to be measured. Another chamber is separated from the metering chamber by a resilient diaphragm and forms an electric capacitor. The capacitance of this capacitor is changed in accordance to deviations of the diaphragm from its true position.

Volumeters and flow meters have been known heretofore in many different configurations. However, the dosing and metering of very small volumes raises still considerable difficulties. This problem is particularly encountered in liquid chromatography.
The present invention provides a device capable of measuring very small volumes and/or volume differences with exactitude and high resolving power. Apart from offering high exactitude, the device of the invention is of very simple design and can be easily integrated into a flow-metering system.
The volumeter according to a preferred embodiment of the invention comprises a metering chamber for the volume to be measured. Another chamber is separated from the metering chamber by a resilient diaphragm and forms an electric capacitor. The capacitance of this capacitor is changed in accordance to deviations of the diaphragm from its true position.


In this vehicle roof molding, a molding body has shelf sections formed relative to the widthwise direction so as to oppose a bottom surface of an upper wall separated by an interval, and a slide plate is movably installed so as to be able to slide along the longitudinal direction of the molding body at a location opposing an opening of the shelf sections, and slide plate has elastic sections that protrude towards the shelf sections and force the slide plate towards the upper wall by receiving a reactive force from the shelf sections. Opening can be opened and closed by sliding slide plate.

1. Field of the Invention
The present invention relates to a vehicle roof molding having a slide plate for opening and closing an opening.
This application is based on Japanese Patent Application No. 2003-196520, the contents of which are incorporated herein by reference.
2. Description of the Related Art
In the past, an opening was provided in a roof molding attached to the roof of an automobile or other vehicle, and mounting parts for attaching rooftop parts such as roof rails, roof ski rack or roof luggage carrier were known to be fastened by insertion into the opening. The opening was covered by a suitable cover (e.g., cap) in the case of not attaching rooftop parts to the roof.
Known examples of covers for covering the opening of a roof molding included a cover having a window that is formed continuous with the opening and a slide plate that opens and closes the window. According to this type of cover, by opening the window by sliding the slide plate, rooftop parts can be attached without having to remove the cover (see, for example, Japanese Patent No. 3318046, and Japanese Unexamined Patent Application, First Publication No. 7-329654).
In the case of the aforementioned sliding cover, extraneous costs are incurred as a result of being composed of two parts consisting of a cover having a window (cover body) and a slide plate.
In addition, together with a level difference being formed between the edges of the opening of the molding and the cover body, a level difference is also formed between the plate body and the slide plate, and these two level differences result in an unattractive appearance.
Although hook-shaped (groove-shaped) guides are provided opening towards the inside in both sides in the widthwise direction of the cover body, when molding the cover body by injection molding and so forth, since the groove sections of the guides are undercut, a slide type is required for the metal mold that forms them, thereby resulting in higher metal mold costs.
Since the aforementioned guides are provided on both sides in the widthwise direction of the window, the opening width of the window is wide and difficult to handle. Consequently, when bolts and so forth are inserted into the window, the bolts end up contacting the edges of the opening, thereby possibly damaging the molding or chassis and so forth.
A locking plate provided near one end of the window in the lengthwise direction has a gap into which the slide plate can be inserted between the locking plate and the cover body, and since the peripheral guides obstruct the formation of this gap, the locking plate and cover body cannot be integrally molded. Thus, a separately molded locking plate must be attached to the cover body, thereby resulting in increased costs.
Since the slide plate employs a structure in which it is hidden behind the cover body when the window is opened, the size of the opening of the roof molding is required to be at least twice the size of the window required for attaching rooftop parts (e.g., roof rails). Consequently, as a result of a large opening being formed in the roof molding, there is insufficient rigidity thereby resulting in the risk of breakage in the vicinity of the opening when the roof molding is installed.
In addition, since the length of the cover body becomes long, there is the risk of it becoming detached from the opening due to thermal contraction in the lengthwise direction. In the cover described in Japanese Unexamined Patent Application, First Publication No. 7-329654, one end of the cover body is fused to the molding, and the other end engages with the edge of the opening. However, since both the structure and production process are complex, costs ends up increasing.

Hashimoto Forming Industry Company Limited


In a mechanical gear transmission, a leaked lubricant liquid, used to lubricate an external ring gear meshing with at least one internal gear wheel, is collected and reintroduced in the system by means of a manifold having a first concave portion, which has a concavity facing towards the external ring gear, so as to house a mass of liquid moved outwards as a result of a centrifugal effect, and at least a second concave portion, which is designed to receive the leaked liquid and has a concavity facing towards the first concave portion; channelling walls being provided to channel the leaked liquid towards one or the other concave portion.

As it is known, mechanical transmissions are cooled and/or lubricated with lubricant-refrigerant oils, so as to increase their duration and obtain, at the same time, reliability even in the case of particularly high transmitted powers.
Furthermore, as it is known, a part of the lubricant oil inevitably leaks out in an axial direction through the teeth and flows outwards as a result of a centrifugal effect. Therefore, in use, a flow of drawn oil is formed, which must be collected and led to the tank, not only to avoid fluid leaks and high managing costs, but also to prevent said drawn oil from becoming, in turn, a source of additional leaks caused by the drawn oil hitting the rotary elements of the transmission.
To this aim, it is known to use external collectors to collect and channel the drawn oil; the oil collected in said external collectors is quickly led towards the oil suction area, filtered and reintroduced in the system.
Known collection collectors, despite being able to partly fulfil the main function of collecting the drawn oil, have proven to be not good enough for the following reasons.
First of all, current collection collectors cannot avoid the formation of splashes and the return of the drawn oil towards the rotary elements and, in general, they are not able to limit fluid-dynamic leaks due to the drawn oil hitting the rotary organs.
In addition, known collection collectors are generally sized taking into account the nominal operating conditions of the transmission. For this reason, known collection collectors turn out to be ineffective when the transmission operates in so-called "off-design" conditions, namely with a rotation speed that is smaller than the nominal or normal operating rotation speed.
Finally, known collection collectors often require strict tolerances and clearances in the coupling with rotary parts that complicate both their manufacturing process and their assembly, often because of the need to provide mechanical seals to intercept oil splashes.


Preparation of terephthalic acid by oxidizing p-xylene with molecular oxygen in an acetic acid solvent in the presence of a catalyst containing at least one heavy metal and bromine. Preparation of terephthalic acid of high purity accompanied by low level of combustion of the acetic acid solvent can be achieved by. (i) introducing p-xylene and molecular oxygen into a first reaction zone kept at a temperature of 180.degree.-230.degree. C. to oxidize at least 95% by weight of the p-xylene into terephthalic acid; PA1 (ii) introducing the reaction mixture obtained from the first reaction zone into a second reaction zone kept at a temperature of 0.degree.-50.degree. C. below the temperature of the first reaction zone in which the reaction mixture is subjected to post-oxidation with molecular oxygen without supplying p-xylene; and PA1 (iii) introducing the reaction mixture obtained from the second reaction zone into a third reaction zone kept at a temperature of at least 230.degree. C. in which the reaction mixture is subjected again to post-oxidation with molecular oxygen without supplying p-xylene, and subjecting the resulting reaction mixture to crystallization and then to solid-liquid separation to recover terephthalic acid.

1. Field of the Invention
This invention relates to a process for preparing terephthalic acid of high purity, more particularly it relates to a process for preparing terephthalic acid of such high purity that permits it to be reacted directly with a glycol for the production of a polyester.
2. Description of the Prior Art
Terephthalic acid is useful as a starting material for polyesters and has usually been prepared by the so-called SD method wherein p-xylene is oxidized with molecular oxygen in an acetic acid solvent in the presence of a heavy metal-containing catalyst. However, the terephthalic acid product obtained by the SD method usually contains a relatively large amount (on the order of 1,000 to 3,000 ppm) of by-product 4-carboxybenzaldehyde (hereinafter referred to as 4CBA") and therefore it cannot be used as a starting material for the production of polyesters for use as fibers, films and the like as it is.
As a result, in the prior art technique the terephthalic acid is reacted with methanol to convert it into dimethyl terephthalate, which is then purified and reacted with a glycol. Alternatively, in recent years, there have developed processes for the purification of the crude terephthalic acid produced by the SD method which comprise dissolving it at an elevated temperature and pressure and contacting the resulting solution with a noble metal catalyst such as palladium, thereby providing a highly pure terephthalic acid containing not more than 30 ppm of 4CBA. However, the former purification technique is disadvantageous in that methanol is inevitably formed during the process of polyester production because of the use of dimethyl terephthalate as one of the starting materials for polyesters. While preferred in that the terephthalic acid can be purified as such, the latter technique requires two separate plant systems because there are differences in the solvents, catalysts and operating conditions employed between the preparation and purification processes of terephthalic acid.
More recently, an attempt has been made to prepare a highly pure terephthalic acid directly in a single plant by employing a particular combination of catalyst, oxidation conditions and oxidation mode. For example, a so-called post-oxidation technique has been known as a means for improving the purity of the terephthalic acid products prepared in oxidation plants of p-xylene. According to this technique, the slurry of terephthalic acid discharged from the oxidation reactor in which p-xylene is oxidized is treated with molecular oxygen at a relatively high temperature before the desired terephthalic acid is recovered from the slurry by solid-liquid separation. The purpose of this treatment is the removal of any intermediate, coloring contaminant and other impurity. More specifically, there is disclosed treatment of the slurry of terephthalic acid with molecular oxygen at a temperature above the reaction temperature (Japanese Patent Publication No. 12695/65) or at a temperature below the reaction temperature (Japanese Patent Laid-open (KOKAI) Nos. 16630/76, 39642/76,85136/77 and 37636/78). Another unique technique in which the post-oxidation is carried out intermittently in a batchwise operation has also been disclosed (Japanese Patent Laid-open No. 31947/72).
Among these techniques, the post-oxidation effected at a temperature below the reaction temperature produces the most favorable results and affords the desired product of relatively high purity as compared with the terephthalic acid products obtained by the conventional process comprising only a single-step oxidation of p-xylene. However, the terephthalic acid products obtained by such lower temperature post-oxidation technique still contain 100 to 500 ppm of 4CBA, which is the limit of 4CBA level attained in commercial-scale operation of this technique. Although such terephthalic acid products can directly be used in polymerization with a glycol without further purification, but they are of medium purity and are inferior in purity to those products which have been subjected to the above-mentioned purification treatment with palladium or other catalyst.
Therefore, there is a continuing need for more economically attractive processes for the preparation of terephthalic acid of high purity in a single plant.


A simplified unitary teat knife is formed of stainless steel rod with a knurled knob on one end and an eye on the other. The eye is flattened and enlarged relative to the rod of the knife and the edges of the eye are sharpened so as to provide cutting surfaces for removal of obstructions within the milk duct as the tool is rotated within the duct by manual manipulation of the knurled knob.

This invention relates to an instrument for removing unwanted obstructions in the milk duct of a cow teat which hinder or stop the flow of milk therethrough. More particularly, this invention is directed toward a simplified unitary knife structure for safely and thoroughly removing scar tissues, small floating cysts, tumors and the like from the interior of the milk duct of a cow's teat.
In the dairy industry, it is not uncommon to encounter difficulty in obtaining milk from one or more teats of a particular cow. This is usually caused by an obstruction of scar tissue, membrane cartilage or other growth within the milk duct of the teat and severely curtails the milk production from the cow. Various devices have been proposed over the years for clearing the duct of the teat from these obstructions, with most of them being of the curette type for actually severing a growth from the lining of the milk duct to various multiple acting instruments for removing growths which have required manipulation of at least two elements requiring generally the use of two hands to affect the desired clearing of the milk duct. U.S. Pat. Nos. 1,837,503; 1,663,761; and 737,293 are typical of this type of apparatus where a hollow shaft has an aperture forming a cutting surface in the distal end and a rod positioned in the shaft interior has a cooperating surface for severing a protrusion captured by said aperture. The manipulation of the interior and the exterior actuating members usually requires two hands. Another approach has been that of U.S. Pat. No. 2,816,552 in which a set of knives is expanded by an internal threaded rod which expands flexible blades to an enlarged diameter so that the interior of the milk duct can be scrapped to enlarge same and remove undesired obstruction. Various veterinary knives have been proposed which can be manipulated to remove tissue from the interior of the milk duct of the teat and these are represented by U.S. Pat. No. 2,676,595.
All of these prior art devices have been difficult to use or have required the expert services of a veterinarian to properly remove the obstruction without injuring the teat of the cow. While some of these devices have permitted removal of the obstruction, they have frequently caused additional injury to the teat and ultimately resulted in lack of milk flow, resulting in premature termination of the milking life of the cow.


Voltage conversion and charging circuitry and method for converting an alternating current (AC) voltage to a direct current (DC) voltage for charging an energy storage element (e.g., battery or supercapacitor). An output capacitance, which is initially charged quickly for use in the slower charging of a battery, also maintains the charge on an input capacitance which provides power for the charging control circuitry during such charging process. In accordance with a preferred embodiment, the DC charging current is substantially constant during a first time interval following which the DC charging power is substantially constant during a second time interval.

1. Field of the Invention
The present invention relates to AC-to-DC voltage conversion circuitry, and in particular, to such conversion circuitry for use in charging a capacitance to a high voltage.
2. Related Art
With increasing use of portable electronic devices, uses of rechargeable batteries has increased as well. As portable devices become smaller, further size reductions are limited by the energy storage elements (e.g., batteries), which must be of a minimum size to provide the necessary power. Further, minimum battery sizes are further dictated by the need for such batteries to last for a minimum desired time of use. As is well known, charging and discharging of chemical-based batteries are limited by the chemistry of the batteries. In particular, charging a chemical-based battery takes a relatively long time (e.g., hours), since the charging process involves the reversal of one or more chemical processes.
However, with the development of supercapacitor technology, it is possible to use a high-voltage, high-density supercapacitor as a major energy storage element. A supercapacitor, known for its fast charging and discharging capabilities (e.g., seconds), is a physical capacitor with energy (=½CV2) stored when a DC voltage is applied. Therefore, the energy density is determined by both the capacitance (C) and the maximum voltage (V). With the energy density of supercapacitors approaching that of chemistry-based batteries, it is becoming more advantageous to develop charging solutions for them.

AC-to-DC voltage conversion and charging circuitry


An integrated process for treatment of wastewater from steam boiler clean operations, containing sodium nitrite and also usually heavy metal ions such as Cu, Fe, Pb, Cr, Cd, Zn and Ni, as well as suspended solids and sludge, to remove the nitrite, substantially reduce the amount of such metal ions and remove suspended solids and sludge in the treated wastewater. The process comprises adding sulfamic acid to the wastewater, particularly in about stoichiometric proportions with respect to sodium nitrite to form gaseous nitrogen. The reaction takes place at ambient temperature and atmospheric pressure. An alkali such as sodium hydroxide is added to the resulting solution in amount sufficient to raise the pH thereof to about 10, and precipitating the metal ions. The precipitates and suspended solids and sludge are removed from the resulting wastewater by settling and filtration, and the wastewater free of nitrite and of substantially reduced metal ion content and free of suspended solids as well as sludge, is in condition for discharge to sewers.

This invention relates to treatment and disposal of sodium nitrite-containing wastewater generated from ship steam boiler maintenance operations, and is particularly concerned with the destruction of the hazardous sodium nitrite in such wastewater, as well as the treatment of toxic heavy metal ions, removal of environmentally objectionable suspended solids, and disposal of sludge also present in such wastewater.
One of the regular maintenance tasks for the Navy's surface ships is cleaning of steam boilers. Wastewater is generated during cleaning of the steam boiler tubes by hydroblast washing. There are two other steam boiler mainteance operations that generate wastewater, namely, (1) hydrostatic tests to check for leaks in boilers before hydroblast washing and (2) boiler lay-up after hydroblast washing and before boiler light off. The water solution used in these operations contains sodium nitrite, a corrosion inhibitor. Thus, the combined wastewater from the above steam boiler cleaning operations is sodium nitrite-containing wastewater. Since the sodium nitrite is not measurably consumed or chemically altered in these cleaning operations, the average nitrite concentration in the wastewater is virtually the same as that in the virgin cleaning solution. The average concentration of sodium nitrite in such wastewater is about 1200 mg/l. However, concentrations of sodium nitrite in the wastewater from the above cleaning operations can be substantially higher, e.g. 1400 mg/l.
Such wastewater is therefore high in sodium nitrite, and also contains suspended solids, sludge, and toxic heavy metal ions. Since the sodium nitrite is the main pollutant of concern, this wastewater is termed "sodium nitrite wastewater".
Although there are no Federal discharge limits to regulate this wastewater, many states have classified such wastewater as hazardous due to the sodium nitrite, heavy metal ions, suspended solids and sludge therein. Some municipal authorities have imposed discharge limits at 33 mg/l for nitrite and 45 mg/l for nitrate. These levels are the same as those in the EPA's drinking water standards. In the case of naval operations, most of the Navy's nitrite wastewater is combined with other wastes at Naval shipyards, with no effective treatment method at hand for the combined wastewater. Disposal is by contract hauling at a high cost per gallon of wastewater. Moreover, the producers of hazardous wastewater, the shipyards, are liable for the safe disposal of such wastewater by contractors.
The main concern with this wastewater is that unmitigated discharge of nitrite, a nutrient, could lead to eutrophication in the receiving waters. Eutrophication results in serious water quality problems, such as taste and odor in water supplies, turbidity, unsightly scums and choking of waterways, and consequently endangers aquatic species such as fish.
Many of the municipal wastewater treatment systems cannot handle high nitrite wastewater, and refuse to accept it.
The use of chemical means to treat nitrite-bearing wastewater is largely presently at the experimental level. In the general literature, for example, few articles are concerned with the chemical treatment of nitrite wastewater, and particularly high nitrite wastewater.
The use of sulfamic acid, NH.sub.2 SO.sub.3 H, for the detoxification of a nitrite-containing wastewater is discussed in German Patent No. 3506825. The patent discloses that nitrite wastewater can be treated with sulfamic acid to generate nitrogen gas and hydrogen sulfate ion. Sulfuric acid, H.sub.2 SO.sub.4, and also sodium hydroxide, NaOH, were added to adjust the pH during the reaction. The patent discloses the use of concentrations of sulfamic acid with respect to sodium nitrite, such as a proportion of approximately 1 to 1 moles of sulfamic acid per mole of sodium nitrite.
In a related article by Y. M. Kostrikin and O. V. Teterina, "Rate of the Reaction of Nitrites with Sulfamic Acid" Energetik, Vol. 10, 1987, page 22, dosage rates and temperature effects were reported for the sulfamic acid and nitrite reaction. In the article it is noted that at 50.degree. C. it would require an excess dosage of 10 times to achieve a 9% nitrite removal, whereas at 70.degree. C. 2.5 times as much sulfamic acid is required.
One object of the present invention is the removal of sodium nitrite from sodium nitrite wastewater produced from steam boiler maintenance operations.
Another object is to treat the above sodium nitrite wastewater in a manner so as to convert the sodium nitrite into an innocuous form.
Still another object is to convert the sodium nitrite in sodium nitrite wastewater to innocuous forms, and also to remove toxic metal ions and suspended solids from such wastewater, to permit discharge of the treated wastewater to sewers.
Still another particular object is to provide an integrated process to treat the hazardous sodium nitrite wastewater completely for discharging directly to sewers without going through the treatment facilities, such as the Navy's industrial wastewater treatment plant, where heavy metal ions removal and sludge reduction are usually carried out.

Treatment of sodium nitrite-containing boiler wastewater

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


A multiple inlet manifold for mixing and transporting therethrough fluids under pressure comprising a manifold body including a plurality of valve inlets and a single outlet, a mixing chamber provided between the valve inlets and the outlet, and a flexible membrane disposed between the valve inlets and the outlet to retain the valve inlets normally closed at selected levels of fluid pressure. Fluid flow under pressure opens a valve inlet to enable fluid flow into the mixing chamber.

1. Field of the Invention
This invention relates to an apparatus for controlling the infusion of fluids under pressure, including medical solutions and drugs. In particular, the present invention relates to a multi-valve infusion manifold having a plurality of inlet lines, a mixing chamber, and at least one outlet line; the manifold is used to administer a combination of fluids and drugs, such as anesthetics or cardiovascular medications, to a patient.
2. Description of the Prior Art
When it is necessary to administer a combination of drugs to a patient during a controlled medical procedure, such as anesthetizing a patient prior to and during surgery, or maintaining a patient on a combination of drugs during his stay in a cardiovascular care or intensive care unit, the known devices have substantial disadvantages.
For example, it is known to administer a combination of selected drugs by individual syringes, with each syringe connected to a stopcock which in turn is connected with a single primary IV set. In one known device, each stopcock has a control level which must be selectively and sequentially manually rotated to administer the desired combination of drugs to the patient. The level of accuracy associated with infusion rates and drug proportions associated with the aforementioned procedure is highly dependent on the skill of the attending medical professional. Potent anesthetic drugs must be precisely and accurately delivered, to avoid adverse effects on the patient. Other similar devices may use a manual stopcock in combination with a back check valve instead of a control lever.
Another manifold apparatus discloses a cannula assembly that includes a housing defining a fluid flow passage having two fluid inlets and one fluid outlet. One of the fluid inlets is shaped to receive the tip of an injection syringe for introduction of fluid to the inlet. Fluid flow through the inlet is controlled by a check valve housing an elastic tubular valve member closing off outlet openings associated with the check valve. Under sufficient pressure of a fluid in the inlet, the tubular valve member deflects outwardly permitting flow through the outlet openings.
A significant problem associated with such devices is back flow, which permits a solution in a delivery line to enter an adjacent delivery line, to produce an undesirable and unintended admixing of fluids within the input lines.
Further, each apparatus described above employs a multiplicity of parts. A multiplicity of parts makes each of the devices described above prone to unintentional leakages due to many fitment connections. In a multi-valve manifold, each valve may have a pre-set "cracking" pressure, which is normally the same for each inlet valve of the manifold. Cracking pressure is defined as the minimum pressure which opens the inlet valve.
Accordingly, it is desirable to provide an improved multi valve manifold which minimizes backflow, i.e., retrograde infusion or crosstalk from one inlet to another at the inlet valve locations. Further, it is desirable to provide a multi-valve manifold having substantially fewer parts than known devices, thus to minimize inadvertent leakage occurring at connections. Moreover, it is desirable to provide, within the constraints of a simplified manifold structure, means enabling variable pre-set pressure settings at each valve inlet. Such improvements would increase the effectiveness of the manifold, reduce its cost, and minimize the disadvantages and inefficiencies present in known devices.

Multi-valve manifold for drug infusion systems


An arrangement for the steering and coupling together of two associated tracked units to form an articulated tracked vehicle set, includes a first upright for releasable coupling to a fixture on one of the tracked units, a second upright for coupling to a fixture on the other tracked unit, a first steering link which is connected in an articulated manner to the first upright about a first horizontal axis and a second steering link which is connected in an articulated manner to the second upright about a second horizontal axis, parallel with the first horizontal axis. The first and second steering links are mutually joined to a steering link unit about a steering pivot with a vertical axis of articulation. Hydraulic ram cylinder units are arranged so as to control relative turning movements between the first upright and the steering link unit, between the second upright and the steering link unit, and between the first and second steering links. The first upright is formed so as to be able to be anchored rigidly in one of the tracked units while the second upright is formed so as to be capable of rotation in bearings in the fixture on the other tracked unit about a longitudinal horizontal axis.

The present invention relates to an arrangement for the steering and coupling together of two associated tracked units to form an articulated tracked vehicle set.
In a previously known steering arrangement for an articulated tracked vehicle set, a front and a rear tracked unit are coupled together by means of a link mechanism which has an essentially vertical axis of articulation about which both tracked units can be turned relative to one another by means of a pair of hydraulic cylinders. The known steering arrangement has, by virtue of its design, certain limitations with regard to characteristics such as steering geometry, controllable articulation between the vehicle units, controllable damping of the movements of the vehicle units relative to one another and the uncoupling possibilities. In the development of larger and heavier tracked vehicle units such characteristics are of increasing importance.
One object of the present invention is thus to make available a steering arrangement which makes possible better control of the articulation between tracked vehicle units of an articulated tracked vehicle set.
A second object of the present invention is to make available a rapid and simple means of coupling and uncoupling two tracked vehicle units.
A further object of the present invention is to make available a steering arrangement with improved steering geometry.
For the achievement of these objects, the steering arrangement according to the present invention is characterized in that it comprises a first upright formed so that it can be releasably coupled to a fixture on one of the tracked vehicle units, a second upright formed so that it can be coupled to a fixture on the other tracked vehicle unit, a first steering link which is connected in an articulated manner to the first upright about a first horizontal, transverse axis, and a second steering link which is connected in an articulated manner to the second upright about a second horizontal, transverse axis which is parallel with the first horizontal axis, and in that the first and second steering links are mutually joined to a steering link unit about a steering pivot with a vertical axis of articulation, in that at least a first hydraulic ram cylinder unit is mounted on the first upright and connected to the steering link unit in order to control relative turning movements between the first upright and the steering link unit about the first horizontal, transverse axis, in that at least a second hydraulic ram cylinder unit is mounted on the second upright and connected to the steering link unit in order to control relative turning movements between the second upright and the steering link unit about the second horizontal, transverse axis, and in that at least a third hydraulic cylinder ram unit is connected between the first and second steering links in order to control relative turning movements between these steering links about the point of articulation, in which the first upright is formed so as to be able to be anchored rigidly in one of the tracked vehicle units and the second upright is formed so as to be capable of rotation in bearings in the fixture in the other tracked vehicle unit about a longitudinal horizontal axis. As a result of such an embodiment of the steering arrangement according to the invention, the design permits the tracked vehicle units firstly to rotate relative to one another about a longitudinal, horizontal axis, secondly to turn relative to one another about two parallel, transverse horizontal axes, thirdly to be uncoupled with the whole of the steering unit remaining fixed to one of the tracked vehicle units, and lastly to be provided with better steering geometry with the vertical axis of articulation positioned centrally between the two tracked vehicle units which are to be coupled together.

Steering arrangement for articulated tracked vehicles


The invention relates to a method and device for reducing the volume or pressure of a fluid which is driven through an opening (3, 17) by moving surfaces. According to said method, the opening (3, 17) is divided in at least two flow channels (5, 6, 14) by means of one or more flexible separation members (4). Each separation member (4) is attached at its rear end relatively to the direction of displacement of said surfaces, and its front finishing end extends inside said opening (3, 17). The inventive method can be advantageously implemented during production and further transformation of strip-shaped materials (paper, cardboard strips, plastic material sheets) for bringing the strip which moves on an element (cylinder, roll, rigid guiding element, winding reel) into close contact with said element.

In a number of fields of technology, moving machine elements or webs or strip-shaped elements to be treated are so arranged or displaced that they form a converging gap. The moving surfaces of the element or material entrained a fluid (gas, liquid) into the gap with a volume or pressure giving rise to negative effects in the event certain boundary conditions are exceeded. The geometry of the gap is either shape stable or of variable shape. Stable shape gaps are formed for example between two rotating rollers whose axes are parallel or between a moving web supported by one guide element and a further element. Shape-variable gaps are formed for example by one element (drive roller, guide roll or roller, winding roll, etc.) and a web running to it or also between two webs running together.
An important technical field of use for the process and the device is the production and further processing of web-shaped materials (paper, cardboard, synthetic resin foils) with which it is frequently required to bring the web into very close contact with an element (roller, roll, or fixed guide element, winding roll).
Especially at high web speeds, the air entrained into the converging gap can be problematical. The entrained air creates an overpressure which presses the web away from the element and which is thus the cause of undesired negative effects. Thus in the roll up of webs of material to wound rolls, as the oncoming web passes onto the wound roll air can be wound into the roll in an undesired manner. With drive rollers the web may begin to float because of an entrained air cushion. The adhesion and thus the drive force is lost. With rollers or other guide elements which serve to control web travel, a floating occurs which interferes with the controlled movement and causes the web to shift laterally. With cooling or heating rollers for webs the entrained air volume reduces the heat exchange with the roll surface and the web and also the heating or cooling efficiency. Since heating and cooling roller groups usually also serve as the traction stations for the web, good adhesion is also required to impart tension to the web. In the cooling of material webs for example paper or cardboard, the entrained air cushion is detrimental to the transfer of the coating material from the applicator to the web.
There are various methods known to counteract the negative effects which find their origin in the entrainment of air into a gap between a web and a further element.
Thus in the winding of webs into wound rolls, pressure rollers are used which squeeze the air out as the web meets the wound roll. Pressure rollers are expensive in their construction and can mark sensitive materials. They can also influence the roll hardness during the wind up in an undesired manner. An improvement in contact with pressure rollers is not possible when the web is coated or when folds may form during the pressing. With drive rollers it is known to improve the contact by a corresponding shaping of the roller surface, for example, by the application of grooves. All of these techniques have in common that they are either relatively expensive to construct or can give rise to undesirable side effects.
A further field of use of the invention is the coating of material webs in the process in which a liquid coating material is applied by means of an applicator element, especially an applicator roller which forms a narrowing application gap with the web. The liquid coating material fed into the application gap of the application element builds up a pressure which influences the quantity applied to the web. An excessively high pressure in the gap, in the case of bibulous paper or cardboard webs, causes the coating material, especially pigment containing coloring agents to penetrate in undesirably large quantities into the web.
The invention thus has as its object the provision of a method by which the volume or the pressure of a fluid entrained into a gap by moving surfaces can be positively reduced in a simple manner without giving rise to undesirable side effects. This object is achieved with the features of patent claim 1.
The separating element used in accordance with the invention effects a pressure or volume reduction in the gap without contacting moving surfaces for example of the web or of another element forming the gap. The separating element requires neither a mechanical drive nor a special energy supply. It enables the possibility of influencing by itself through its shape and position the pressure of volume relationships in the gap. Thus, for example, in the winding up of a material web, even with a reduced quantity of entrained air, the desired winding quality can be maintained.
The invention makes use of the physical effect that the transition between two streams separated by a partition into two passages of reduced height to only one stream in one passage of greater height, results in a pressure reduction depending upon the viscosity of the flowing fluid, the length and height of the passages and the flow velocity and/or a reduction in the volume flow of the fluid into the gap.
The dependent claims contain preferred variants and embodiments of the invention in its use in the production and processing of web shaped materials.

Method and device for reducing the volume or pressure of a fluid which is driven through an opening by moving surfaces


A process to improve the surface properties of products made, at least in part, from silicone rubber is disclosed. The products find uses in industrial and medical device applications, such as drug-pump seals and valves, membranes, mammary prostheses, artificial heart diaphragms, pacemaker lead insulation and the like. The process is designed to change the silicone rubber's surface to one that is characterized by low friction, being antithrombotic, inkable, more wear resistant and deformable, and also being hydro-compatible. The process includes subjecting the product's silicone rubber surface to ion bombardment with gaseous ions that diffuse out with doses and at energy levels at least about 3E14 ions/cm.sup.2 at 80 keV.

1. Field of the Invention
The present invention relates generally to ion implantation of silicone rubber and, more importantly, to an ion implantation process for silicone rubber designed to change the silicone rubber's surface to one characterized by low friction, being antithrombotic, inkable, wear resistant, deformable and hydro-compatible.
2. The Prior Art
Silicone rubbers find important and varied uses in industrial and medical device applications. In the medical field, manufacturers use silicone rubber, inter alia, in forming seals and valves for many groups, for membranes for insulators in electrostimulation devices and pacemakers, for artificial heart diaphragms, in penile implants, for mammary prostheses and the like. Silicone rubber is favored in the applications because it is biocompatible, is permeable to gases, is easily molded and is highly deformable.
Silicone rubber is not without its drawbacks, however. It evinces high friction against metals, other polymers and itself. Such high friction requires the addition of lubricating agents, such as fluorosilicone oil, in many applications. When the addition of lubricating agents is not possible, as in certain in-vivo implants, it often leads to premature failure due to abrasive wear and/or cracking. This property of high friction in silicone rubbers is the result of the surface morphology and of the surface energy. During their molding, whether by companion, transfer or injection molding, silicone rubber products at times acquire a rough surface morphology due to the compressive stresses built into them from the molding operation. Secondly and more importantly, certainly in medical device applications, bodily tissue and cells have a tendency to stick and stay stuck onto the silicone rubber surface, whence they may enter the vascular system, causing occlusion, clotting and strokes Since silicone rubber is non-planar and hydrophobic due to its surface energy, it has not been easily inkable.
Attempts to improve the surface properties of silicone rubber products have, for the most part, concentrated on providing suitable coatings therefor. Such coatings have included hydrogel or fluorosilicone lubricants, sulfonation processes or the employment of special adhesives. See U.S. Pat. Nos. 4,100,309 and 4,119,094 of Michael J. Micklus et al., "Coated Substrate Having a Low Coefficient of Friction Hydrophilic Coating and a Method of Making the Same". Each of these coatings introduces, however, "shelf-life" problems to the silicone rubber products. Lubricants used in implanted drug-pumps wear off with time and enter the vascular system, being the source of potentially life-threatening complications. Hydrogel coatings also can detach from silicone rubber devices due to excessive heat and/or hydration, heralding a wealth of complications and device failures. And the sulfur groups from the applied sulfonation processes severely limit the shelf-lives of the silicone rubber devices.
More recently, a Japanese corporation, Terumo Corporation, has investigated the effects of ion implantation on plasma protein adsorption onto silicone rubber sheets. See Yoshiake Suzuki et al, "Effects of Ion Implantation on Protein Adsorption onto Silicone Rubber," MRS Symposium Proceedings (1989), vol. 110, pp. 669-679. The article notes in the Abstract, inter alia, that "Ion implantation causes the surface roughness to increase by 1-5 times," see lines 5-6 of the Abstract. The Abstract also states that "The results of XPS measurements showed that implanted elements were incorporated in a gaussian like distribution and host elements were redistributed in the polymer matrix." See Abstract, lines 10-12. Our aims are opposed to both of those observations. We are interested in reducing surface roughness to achieve low surface friction and smoothness. We also are interested in improved wear resistance and improved anti-thrombogenicity. We are not interested in improving plasma protein adsorption onto the surfaces of the ion implanted silicone rubbers, however, which is a sort of protective coating.


A method of making a hollow shaft having multiple functional elements arranged along the axis of an inner shaft tube is provided. Several multiple shafts equipped with functional elements may be joined by expansion using probes inserted into the shafts and connected to a high pressure generator. In addition, a method of providing functional elements to an inner tube wherein the individual non-round functional elements have annular projections concentric to the base circle is provided, where the internal diameter of the functional elements is slightly larger than the external diameter of the shaft tube. The functional elements have an annular region on their lateral edges of approximately half the wall thickness that complements the adjacent non-round functional element to achieve a full wall thickness and the annular projections are produced by re-formation of the profile tube. The present invention permits manufacturer of, for example, multiple cams, while retaining torsional stiffness of the cam shaft and allowing for close placement of the functional elements with respect to one another.

1. Field of the Invention
The invention relates to assembled hollow shafts, comprising an inner shaft tube with external functional elements, joined by means of radial expansion in given sections in the axial direction, whereby the inner shaft tube is deformed plastically in the expansion sections and the functional elements are only deformed resiliently in the expansion sections and the expansion sections lie between the functional elements, whereby the functional elements are combined in part into multiple functional elements. The invention also relates to processes for producing shafts of this type and for producing multiple functional elements to be used in manufacturing assembled hollow shafts.
2. Description of the Prior Art
Given the growing importance of multiple valve technology in the field of drive and control shafts (especially cam shafts) for internal combustion engines, the problem of constructing shafts that have many closely adjacent elements, such as cams and other functional parts as well as slide bearings and axial stops, arises ever more frequently. This problem poses increasing difficulties when conventional methods are used. Another problem, especially in large-diameter shafts, is that of weight, which increases quadratically.
Interesting approaches to this set of problems have been made, particularly in the field of assembled hollow cam shafts. Although the problem of cam spacing with decreasing weight can be overcome, other difficulties then arise with respect to decreasing torsional stiffness. Furthermore, the number of functional elements that must be applied to and positioned precisely on each shaft becomes very large. In the case of truck shafts, especially for diesel engines, this problem is accompanied by another difficulty, namely, the necessity of keeping the wall of the hollow shaft relatively thick, even in the single-layered areas between functional elements, for the sake of the required torsional stiffness. The advantage of reduced weight can therefore not be achieved to the desired extent.
Finally, lengthy preparation time is required prior to assembly, especially in the case of long shafts, due to the slow introduction of high-pressure probes into the hollow shaft, for example. This lengthy preparation time reduces the productivity of expensive capital resources.
A reduction in at least some of the aforementioned problems in the production of assembled hollow shafts can be attained by using multiple functional elements, e.g., multiple cams. For example, it has been proposed to produce multiple cams from tube profiles by means of twisting, or from sheet metal blanks, which are suitably shaped, formed into annular bodies and welded.
The first of these proposals, however, is limited to uniform cam profiles. Furthermore, the cams do not possess great stiffness against external pressure, e.g., follower pressure. Moreover, both proposals have very sharp limitations with respect to the spreading or the varied angular pitch of cam tips around the circumference. This limitation can be overcome in the second proposal only by using an expensive process variant.
Generic hollow shafts are known from EP-A-292 795. Double cam elements are described therein, in which an expansion section is arranged between the two external cam sections. The reason for this structure is that the cam sections of the one-piece double cam are subsequently hardened and, due to embrittlement, are not resiliently deformable to the desired extent, so that only the non-hardened middle sections are expanded. These double cams have the disadvantage, however, that the cam sections must be clearly spaced from one another, as a result of which the design of shafts with many closely adjacent functional elements is made more difficult or prevented. Moreover, the combination is limited to two elements with the same function or load.

Emitec Gesellschaft fur Emissionstechnologie mbH


A thyristor includes a semiconductor body having a first emitter layer and a first base layer on an anode side, a second base layer and a second emitter layer on a cathode side, a cathode contact, and an electrically insulating insulation layer having openings. The insulation layer is disposed between the second emitter layer and the cathode contact. The openings have dimensions and spacings making the insulation layer form an electrical resistor for reducing current filamentation. A series resistor is incorporated on the cathode side and is formed by the pierced insulation layer between the cathode side metallizing, forming the terminal contact, and the doped semiconductor material of the emitter on the cathode side. The openings are preferably cylindrical. In a silicon component element, the insulation layer preferably is SiO2 or Si3N4, or a layered succession of SiO2 and Si3N4.

The present invention relates to a deactivatable thyristor, in which the filamentation during the deactivation operation is averted.
Deactivatable thyristors tend to filamentation during the deactivation operation, because they include a very great number of parallel-connected single thyristors. The causes of these filamentations are lateral discontinuities in the component element, which can for instance be due to the finite conductivity of the metallizing on the cathode side, to nonhomogeneous distributions of the dopant profiles and of the substrate service life, to nonhomogeneous pressure contacting, or to nonhomogeneous etched features. Because of the current filamentation, the maximum current that the component element is capable of turning off without destruction is severely reduced.
This filamentation can be reduced considerably by using series resistors, since the voltage drop established along these series resistors counteracts the filamentation. However, care must be taken that this voltage drop not become too great; otherwise the on-state voltage of the component elements rises too sharply. In principle, series resistors can be embodied by depositing polysilicon on the emitter on the cathode side. However, this is technologically complex, and there are narrow limits to the range within which the resistor can be adjusted.
The object of the present invention is to disclose a deactivatable thyristor in which the effects caused by filamentation are largely avoided.
This object is attained with the thyristor having a semiconductor body, with an emitter layer on the anode side, a base layer on the anode side, a base layer on the cathode side, and an emitter layer on the cathode side, in which an electrically insulating insulation layer, which has openings, is present between the emitter layer on the cathode side and a cathode contact applied over it; and in which the dimensions and spacings of these openings are selected such that the insulation layer forms an electrical resistor for reducing current filamentation.
In the thyristor according to the invention, a series resistor is incorporated on the cathode side. The series resistor is formed by a pierced insulation layer between the metallizing on the cathode side, which forms the terminal contact, and the doped semiconductor material of the emitter on the cathode side. The openings in this insulation layer are preferably cylindrical. In a component element comprising silicon, the insulation layer preferably comprises SiO2 or Si3N4, or a layered succession of SiO2 and Si3N4.


A semiconductor includes an N-type impurity region provided in a substrate. A P-type RESURF layer is provided at a top face of the substrate in the N-type impurity region. A P-well has an impurity concentration higher than that of the P-type RESURF layer, and makes contact with the P-type RESURF layer at the top face of the substrate in the N-type impurity region. A first high-voltage-side plate is electrically connected to the N-type impurity region, and a low-voltage-side plate is electrically connected to a P-type impurity region. A lower field plate is capable of generating a lower capacitive coupling with the substrate. An upper field plate is located at a position farther from the substrate than the lower field plate, and is capable of generating an upper capacitive coupling with the lower field plate whose capacitance is greater than the capacitance of the lower capacitive coupling.

1. Field of the Invention
The present invention relates to a semiconductor device, and more particularly to a semiconductor device including a termination structure, and a method for fabricating such a semiconductor device.
2. Description of the Background Art
Power devices are semiconductor elements mainly intended for electric equipment for use in power conversion or power control, and allow for higher breakdown voltages and larger currents than in typical semiconductor devices. Power devices need to sustain a high voltage by cutting off current when a reverse voltage is applied thereto. In order for power devices to withstand higher breakdown voltages, "Handbook of Power Device & Power IC" edited by The Investigation Committee on High-Performance and High-Functionality Power Device & Power IC, The Institute of Electrical Engineers of Japan, and published by Corona Inc. (pp. 54-64 and 170-174) discloses a FLR (Field Limiting Ring) structure and a termination structure such as a field plate structure.
In the FLR structure, a main junction between an N-type impurity region of low concentration and a P-type impurity region located at an internal surface of this N-type impurity region is surrounded by a plurality of ring-shaped P-type impurity regions. With this structure, when a reverse voltage is applied, junctions formed by the respective ring-shaped P-type impurity regions sequentially produce punch-through before the main junction punches through, thereby reducing the electric field of the main junction.
Further, Japanese Patent Laying-Open No. 2002-231944 and Japanese Patent Laying-Open No. 05-190693, for example, disclose a structure including a ring-shaped conductive film provided on each FLR with an insulation film interposed therebetween. With this structure, the conductive films function as equipotential rings, thereby mitigating the influence of movable ions contained in the insulation film.

Semiconductor device and method for fabricating the same


A resin film has a photoelastic coefficient of from 0 to 30×10−8 cm2/N; and Re satisfying the following formulae (1) to (4):20 nm<Re(548)<300 nm  Formula (1):0.5<Re(446)/Re(548)<1  Formula (2):1.0<Re(629)/Re(548)<2.0  Formula (3):0.1%≦[{Re(548) at 25° C., 10% RH−Re(548) at 25° C., 80% RH}/Re(548) at 25° C., 60% RH]≦20%,  Formula (4):wherein Re(λ) represents an in-plane retardation at a wavelength of λ.

1. Field of the Invention
The present invention relates to a resin film, a production method thereof, a polarizing plate using the resin film, and a liquid crystal display device.
2. Description of the Related Art
The usage of a liquid crystal display device is being broadened year by year as a space-saving image display device with low power consumption. Conventionally, the large viewing angle dependency of image is a great defect of the liquid crystal display device. However, in recent years, a liquid crystal mode assured of high viewing angle by a VA mode is put into practical use and by virtue of this mode, the demand for a liquid crystal display device is abruptly expanding also on the market requiring a high-quality image, such as television.
The VA-mode liquid crystal display device is advantageous in that the contrast is generally high as compared with other liquid crystal display modes, but there is a problem that the contrast and tint are greatly changed depending on the viewing angle. For solving this problem, a method of using two kinds of retardation layers differing in the optical properties and thereby obtaining a VA-mode liquid crystal display device where the black display is clear and achromatic even when viewed from an oblique direction, is disclosed (see, for example, JP-A-2003-121641 and JP-A-2006-323329 (the term "JP-A" as used herein means an "unexamined published Japanese patent application")).
Furthermore, in International Publication No. 2003/032060 pamphlet, a method of improving a tint change depending on the viewing angle by combining an A plate with Re becoming smaller on the shorter wavelength side and a C plate with Rth becoming larger on the shorter wavelength side is proposed.
Particularly, as for the A plate of which Re becomes smaller on the shorter wavelength side, in addition to the stretched film of modified polycarbonate described in International Publication No. 2003/032060 pamphlet, for example, a stretched cellulose acylate film is proposed in JP-A-2002-22941 and a stretched film of modified norbornene resin is proposed in JP-A-2003-292639.

Resin film, production method thereof, polarizing plate and liquid crystal display device


The present invention provides an industrially available method for efficiently producing high-purity S-(−)-6-hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid excellent in solid-liquid separability from an S-(−)-6-hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid ester, and also provides products obtained by the method.

Conventional examples of methods for producing chromane compounds include a multi-step method in which a phenol and an unsaturated carbonyl compound are used as starting materials (see, for example, Patent Document 1); and a method in which a phenol, a formaldehyde, and an unsaturated compound are allowed to react without use of any catalyst or in the presence of an acid or amine (see, for example, Patent Documents 2, 3 and 4).
An optically active 6-hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid derivatives can be obtained by way of an optical resolution of 6-hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid ester obtained by the method of Patent Document 4, in accordance with 1) a diastereomeric resolution with an optically active amine (see, for example, Patent Documents 5 and 6); or 2) an enantiospecific hydrolysis of (±)-6-hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid ester using an enzymatic catalyst (see, for example, Patent Document 7).
Although it is possible to produce S-(−)-6-hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid in accordance with the above mentioned methods, there are still some points which require improvement when high purity S-(−)-6-hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid is provided industrially and economically. The present inventors have already proposed methods for producing 6-hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid easily in good yield. However, even in these methods, when S-(−)-6-hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid ester is produced and then hydrolyzed to produce S-(−)-6-hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid, the resulting S-(−)-6-hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid is deteriorated in yield and purity, producing a reacted solution in the form of a pasty inseparable slurry, if operation conditions after the hydrolysis are improper.
Therefore, for the practice on an industrial scale, it is required to establish means for solving these problems to obtain the target product economically. However, none of the conventional and prior art references has disclosed a production condition for S-(−)-6-hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid excellent in efficiency such that solid/liquid separation and drying of crystals are made easier.    Patent Document 1: U.S. Pat. No. 4,026,907 specification    Patent Document 2: Japanese Patent Laid-Open (Kokai) No. S60-92283    Patent Document 3: Japanese Patent Laid-Open (Kokai) No. H7-97380    Patent Document 4: Japanese Patent Laid-Open (Kokai) No. 2003-146981    Patent Document 5: Japanese Patent Laid-Open (Kokai) No. H11-80149    Patent Document 6: International Publication No. WO02/12221 pamphlet    Patent Document 7: U.S. Pat. No. 5,348,973 specification

Method of producing S-(−)-6-hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid and product obtained by the method

Abstract: Under a temperature condition of 50-80° C. in an aqueous solvent, (A) an S-(−)-6-hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid ester represented by the general formula (1) is hydrolyzed under a basic condition for 1-3 hours; then (B) the insoluble matters contained in the reaction solution resulting from the hydrolysis are removed; and (C) an acid is added to the resulting solution to effect crystallization; provided that R in the general formula (1) represents an alkyl or aryl group.


An electroluminescent device comprises first and second electrodes, a layer of an electroluminescent polymer disposed between the electrodes; and a hole injection layer disposed between the first electrode and the layer of electro-luminescent polymer. The hole injection layer is formed from a polymer having a main chain and a plurality of sidechains each attached at one of its ends to the main chain, at least some of the sidechains containing an electron-donating substituent such that the oxidation potential of the polymer is less positive than about +1.6 V, and is desirably in the range of about +0.4 to about +0.8 V. Preferred electron-donating groups are di- and triphenylamino groups.

This invention relates to an electroluminescent device with a polymeric charge (hole) injection layer. More specifically, it relates to such a device in which the hole injection layer is formed from a polymer bearing electron-donating substituents. The invention also relates to a process for generating electromagnetic radiation using such a device.
In recent years, a great deal of research has been conducted into electroluminescent materials, that is to say materials which emit electromagnetic radiation (typically visible light) when an electric current flows through the material. Electroluminescent materials are potentially useful for the construction of image display devices, which could be yew thin and lightweight, and could thus advantageously replace cathode ray tubes, gas plasma displays, liquid crystal displays and other types of image display devices.
Electroluminescent devices comprise, at a minimum, a pair of electrodes with a layer of electroluminescent material sandwiched between the electrodes. Several different types of electroluminescent materials are known; see, generally as to development of such materials, International Patent Application No. PCT/GB90/00584 (Publication No. WO 90/13148). The first type to be developed was inorganic semiconductor materials such as gallium phosphide and zinc sulfide. However, such inorganic electroluminescent materials are not readily usable in large image display devices, and many of them suffer from practical drawbacks, including poor reliability. Accordingly, most recent research has concentrated on organic electroluminescent materials.
Many organic compounds, especially polycyclic arenes such as anthracene, perylene, pyrene and coronene, are electroluminescent. However, electroluminescent devices using these monomeric organic compounds suffer from poor reliability, and also present difficulties in preparing the thin layers of the materials needed for use in practical electroluminescent image display devices, and the electrodes needed for electrical contact with such layers. Techniques such as sublimation of the organic material produce layers which are soft, prone to recrystallization and unable to support high temperature deposition of electrode layers, while techniques such as Langmuir-Blodgett film deposition produce films of poor quality, dilution of the active material and high cost of fabrication. Prior art electroluminescent devices formed from these materials, such as that described in U.S. Pat. No. 3,621,321, typically suffer from high power consumption and low light output.
Attempts have also been made to use solid solutions of monomeric organic electroluminescent materials in non-electroluminescent polymers as the active layer in electroluminescent devices; see, for example, U.S. Pat. No. 4,356,429. However, use of such solid solutions carries a substantial risk of phase separation by crystallization of the electroluminescent material out of the polymer, especially in environments where the electroluminescent device may be subjected to large changes in temperature. In addition, often it is difficult to find a non-electroluminescent polymer which can dissolve a large proportion of the active electroluminescent material to form the necessary solid solution.
Accordingly, research has been carried out on electroluminescent polymers having an electroluminescent group incorporated into the polymer itself However, electroluminescent devices based upon such polymers tend to require high operating voltages and accordingly may have relatively low electroluminescent efficiencies. The operating voltages of such electroluminescent devices can be lowered by reducing the thickness of the electroluminescent polymer layer, but if one attempts to reduce this thickness to about 0.1 .mu.m, defects (so-called "pinholes") appear in the electroluminescent layer and act as shorts between the electrodes, thus destroying the electroluminescent properties of the device. To allow the use of thin electroluminescent layers without the formation of pinholes or other defects, it is known to provide electroluminescent devices with a hole injection layer between the anode and the electroluminescent material and/or an electron injection layer between the cathode and the electroluminescent material. For example, U.S. Pat. No. 4,356,429 to Tang describes an electroluminescent device having a metal porphyrin as a hole injection layer and a tetraphenylbutadiene/polystyrene electroluminescent layer. Similarly, Adachi et al., Jap. J. Appl. Phys., 27(2), L269-L271 (1988) describe an electroluminescent device having an electroluminescent layer formed from a polycyclic hydrocarbon, a hole injection layer formed from an aromatic diamine and a electron injection layer formed from a perylene tetracarboxylic acid derivative.
Ito et al, in Chemical Abstracts 120:311,003f (1994) (Abstract of Japanese Pat. Application Publication No. 05-271,652, published Oct. 19, 1993) describe an electroluminescent device having a hole injection layer formed from a cross-linked polymer containing triphenylamine groups. The device is stated to shown good heat resistance and transparency. However, the cross-linked polymeric hole injection layer described by Ito is inconvenient to prepare. Conventionally, each layer of an electroluminescent device is formed by dissolving the material used to form the layer in a solvent, applying a thin film of the resulting solution on to a substrate by spin coating or a similar technique, and drying the coated substrate to remove the solvent and form the desired thin layer. It is not possible to apply the Ito et al. cross-linked polymer in this manner, since in its cross-linked form the polymer is virtually insoluble in all common solvents. Accordingly, the Ito et al. hole injection layer must be prepared by coating the appropriate monomer from solution, drying to form a layer of the monomer and then polymerizing the monomer in situ to form the cross-linked polymer. Such in situ polymerization is in practice inconvenient since it requires the use of additional equipment often not readily available at locations where electroluminescent devices are prepared, and moving the coated substrate to appropriate apparatus may result in contamination of the coated substrate, with possible damage to the integrity of the thin layers.
The present invention provides an electroluminescent device provided with a hole injection layer which possesses advantages similar to those of the Ito et al. hole injection layer but which can be applied without the disadvantages associated with in situ polymerization.

Electroluminescent device with polymeric charge injection layer


An x-ray tube is provisionally assembled by interposing an upright part (12A) projecting from a first brazing agent (A) between a stem (3) and a bulb (2), and by interposing a second brazing agent (B) between the bulb (2) and an output window (4). This temporary assembly is conveyed into a vacuum brazing oven (P). Since a gap (K) is provided between the stem (3) and the bulb (2) by the upright part (12A), gas inside the bulb (2) can be discharged through the gap (K). Then, the vacuum brazing oven (P) is heated to a predetermined temperature to melt the first and second brazing agents (A, B), to thus fuse-bondingly fix the stem (3) and the output window (4) to the bulb (2). Brazing connection is completed in the vacuum brazing oven (P) while maintaining the sealed vessel (7) in a high vacuum condition without provision of a discharge pipe in the stem (3).

The present invention relates to a method for producing an x-ray tube, and more particularly, to the method for producing the x-ray tube wherein a ceramic bulb, a ceramic stem, and an output window are brazed together using a brazing agent.
Japanese Patent Application Publication (Kokai) Nos. HEI-9-180630 (corresponding to U.S. patent application Ser. No. 09/113,372) and HEI-9-180660 (corresponding to U.S. patent application Ser. No. 09/113,371) disclose technologies in this field. In the disclosed method for producing the x-ray tube, at a position outside of a vacuum brazing oven, a stem is set through a brazing agent at one end of a bulb, and an output window is set through a brazing agent at another end of the bulb. The thus pre-assembled x-ray tube is conveyed into the vacuum brazing oven, and the oven is heated at high temperature for melting the brazing agent after the oven is evacuated to 1xc3x9710xe2x88x926 Torrs. Thus, a combination of the bulb, the stem and the output window provides a sealed vessel in the oven. Thereafter, the x-ray tube is taken out from the oven, and then, further evacuation is carried out with respect to an inside of the sealed vessel through a discharge pipe provided at the stem to provide high vacuum condition. Then, the discharge pipe is plugged. In this way, connection of components using the brazing agent improves assembleability of the x-ray tube.
However, the following problems remain in the conventional x-ray tube due to the above-described production method.
That is, for connecting each component of the x-ray tube with brazing, high vacuum is provided in the oven and the brazing agent is melted by heating the oven. Upon completion of the brazing, the assembled x-ray tube is taken out from the oven, and high vacuum is again provided in the sealed vessel through the discharge pipe. Accordingly, the evacuation process is performed twice, which is a task to be solved for improving an efficiency of assembly of the x-ray tube.
It is an object of the present invention to overcome the above-described problems and to provide a method for producing the x-ray tube capable of improving assembling efficiency thereof.
To attain the above described object, the present invention provides a method for producing an x-ray tube which includes a sealed vessel provided with a bulb having one open end and another open end, a stem fixed to the one open end of the bulb through a first brazing agent, and an output window fixed to the another open end of the bulb through a second brazing agent, a filament disposed in the sealed vessel for emitting electrons, and a focussing electrode disposed in the sealed vessel and surrounding the filament, incidence of the electron from the filament into the output window providing x-ray discharge outwardly through the output window, the method comprising the steps of;
interposing a flange portion of the focussing electrode between the bulb and the stem, the flange portion having an outer peripheral end portion provided with a skirt portion where a gas discharge port allowing an inside of the bulb to communicate with an outside is formed;
positioning a projecting portion of the first brazing agent between the stem and the flange portion of the focussing electrode for maintaining the stem away from the flange portion, and positioning a third brazing agent between the flange portion and the bulb, and positioning the second brazing agent between the bulb and the output window to provide a temporary assembly of the x-ray tube; and
disposing the temporary assembly of the x-ray tube in a vacuum brazing oven, and discharging gas from an inside space of the vessel defined by the bulb, the stem and the output window through a gap between the flange portion and the stem, the gap being provided by the projecting portion of the first brazing agent.
According to the above-described method for producing the x-ray tube, the gap is positively provided between the stem and the flange portion by interposing the projecting portion of the first brazing agent between the stem and the flange portion. Thus, gas inside the bulb can be discharged through the gap in the vacuum brazing oven. While the discharge of gas from the inside space is continued, the projecting portion of the first brazing agent, the first brazing agent, the second brazing agent and the third brazing agent are melted by increasing the temperature of the vacuum brazing oven to a predetermined temperature to perform brazing connection between the flange portion and the stem, between the bulb and the flange portion, and between the bulb and the output window. In this way, brazing connection is completed in the vacuum brazing oven while maintaining the sealed vessel in a high vacuum condition without provision of a discharge pipe in the stem. That is, the x-ray tube without the gas discharge pipe can be fabricated with an advantage that the assembly of the x-ray tube is completed concurrently with the take-out of the x-ray tube from the vacuum brazing oven.
Further, gas discharge is achieved through the gap between the stem and the flange portion of the focussing electrode, and the flange portion of the focussing electrode is interposedly fixed between the bulb and the stem by melting the first and third brazing agents in the vacuum brazing oven. Consequently, the focussing electrode can be easily and stably fixed to the sealed vessel.
Furthermore, positioning of the focussing electrode with respect to the stem can be easily and reliably performed by simply positioning the stem into the skirt portion during assembly of the x-ray tube. Further, gas in the sealed vessel can be smoothly discharged through the gas discharge port formed in the skirt portion. That is, gas discharge from the sealed vessel can be assured by forming the gas discharge port in the skirt portion irrespective of the provision of the skirt portion at the focussing electrode.
In this case, preferably, the gas discharge port is positioned in association with the projecting portion of the first brazing agent. With this arrangement, since the gap between the bulb and the stem is stably provided by the projecting portion, more stable gas discharge is achievable by the alignment between the projecting portion and the gas discharge port.
Preferably, the projecting portion provided at the first brazing agent is formed of a material identical with the material of the first brazing agent. In this case, the first brazing agent is formed of a ring shaped sheet like member, and the projecting portion comprises an upright pawl formed by cutting a part of the first brazing agent and folding the cut part. By providing the projecting portion in this fashion, it is unnecessary to provide a separate projecting portion to the ring like main body of the brazing agent. The projecting portion can be easily provided as an upright pawl by forming L-shaped or U-shaped slit in the main body of the brazing agent and by folding the slitted part.
In the above described production method, preferably, the second brazing agent can have a projecting portion which spaces the output window away from the bulb to provide a gap through which gas discharge can be performed. With this arrangement, gas discharge at the both open ends of the bulb can be performed, to thus further promote gas discharge.
Similar to the projecting portion of the first brazing agent, the projecting portion at the second brazing agent is preferably formed of a material identical with the material of the second brazing agent. Further, the second brazing agent is preferably formed of a ring shaped sheet like member, and the projecting portion of the second brazing agent comprises an upright pawl formed by cutting a part of the second brazing agent and folding the cut part.
Preferably, a cap surrounding the output window is provided, and the output window is interposed between the bulb and the cap, and the second brazing agent is positioned between the bulb and the output window, and a fourth brazing agent is positioned between the output window and the cap. The second brazing agent has a projecting portion spacing the output window away from the bulb to provide a gap through which gas discharge is performed. With this arrangement, the output window can be interposed between the cap and the bulb by melting the second and fourth brazing agents in the vacuum brazing oven. Thus, the cap can protect the output window and can stably fix the output window.
Preferably, the cap includes a sleeve portion surrounding the end portion of the bulb and the sleeve portion is formed with a gas discharge port allowing an inside of the bulb to communicate with an outside. With this arrangement, the positional relationship among the output window, the cap and the bulb can be simply and stably determined by positioning the output window and the end portion of the bulb into the sleeve portion of the cap during assembly of the x-ray tube. Further, gas discharge out of the sealed vessel can be smoothly achieved through the gas discharge port formed in the sleeve portion. That is, stable gas discharge is achievable by forming the gas discharge port in the sleeve portion irrespective of the provision of the sleeve portion at the cap.
Preferably, the gas discharge port of the cap is positioned in association with the projecting portion of the second brazing agent. With this arrangement, more stable gas discharge can be achieved by the alignment between the projecting portion and the gas discharge port because the gap between the bulb and the output window can be stably maintained by the projecting portion.
Further, the present invention provides a method for producing an x-ray tube which includes a sealed vessel provided with a bulb having one open end and another open end, a stem fixed to the one open end of the bulb through a first brazing agent, and an output window fixed to the another open end of the bulb through a second brazing agent, and a filament disposed in the sealed vessel for emitting electrons, incidence of the electrons into the output window providing x-ray discharge outwardly through the output window, the method comprising the steps of;
interposing the output window between the bulb and a cap surrounding the output window, the cap having a sleeve portion surrounding the end portion of the bulb, the sleeve portion being formed with a gas discharge port which communicates the inside of the bulb with the outside,
positioning the first brazing agent between the bulb and the stem, positioning a projecting portion of the second brazing agent between the bulb and the output window, and positioning a fourth brazing agent between the output window and the cap to provide a temporary assembly of the x-ray tube where the output window is spaced away from the bulb, and
disposing the temporary assembly of the x-ray tube in a vacuum brazing oven, and discharging gas from an inside space of the vessel defined by the bulb, the stem and the output window through a gap between the bulb and the output window, the gap being provided by the projecting portion of the second brazing agent.
According to the above described method for producing the x-ray tube, the gap is positively provided between the output window and the bulb by interposing the projecting portion of the second brazing agent between the output window and the bulb. Thus, gas inside the bulb can be discharged through the gap in the vacuum brazing oven. While the discharge of gas from the inside space is continued, the first brazing agent, the projecting portion of the second brazing agent, the second brazing agent and the fourth brazing agent are melted by increasing the temperature of the vacuum brazing oven to a predetermined temperature to perform brazing connection between the bulb and the stem and between the bulb and the output window. In this way, brazing connection is completed in the vacuum brazing oven while maintaining the sealed vessel in a high vacuum condition without provision of a discharge pipe in the stem.


A digital to analog converter (DAC) method and apparatus employs a multiplying-adding DAC, eliminating digital adder circuitry. Examples are given for multiplying a 3-bit binary number by a 2-bit binary number; however, there are no limitations to the bit-widths of the numbers to be multiplied. The multiplying-adding DAC method can be scaled up or down in bit-width by feeding the DAC with partial sums and adjusting the DAC weights accordingly. An analog to digital converter (ADC) can be placed after the DAC to generate a digital output. By multiplexing preset digital data into the DAC core for return to zero (RTZ), a true zero that is the midpoint of the DAC output range is achieved. It does not return to a rail for single-ended outputs. RTZ in DAC circuits doubles the null frequency of sin(x)/x roll-off inherent in DACs and also helps reduce switching glitches in the DAC output.

DACs are used in an increasing number of applications, many requiring lower power consumption and higher operating frequencies. Direct Digital Synthesis (DDS) is one of these applications. Basic DDS circuits include an electronic controller, random access memory, a frequency reference, a counter, and a DAC. Some versions of DDS circuits include random access memory (RAM).
Multiplying-Adding
Within direct digital synthesizer circuits, improved spurious free dynamic range (SFDR) is desired. One method to achieve improved SFDR is by adding interpolation to the output of the DDS. To determine the interpolation, an approximation of X sin(theta)+Y cos(theta) can be used. This approximation necessitates the need for an efficient method of multiplication in order to preserve high speed operation of the DDS and minimize power consumption. The traditional method of multiplying two binary numbers involves the use of digital adder circuitry. Digital adder circuitry increases the power consumption of the circuit and reduces operating speed.
The following explanatory discussion involves quotients A and B. A is a 3-bit binary number and B is a 2-bit binary number. The notation for the expanded version of A is A2 A1 A0 and the notation for the expanded version of B is B1 B0. The use of the specific bit-widths is convenient for illustration and implementation, but any bit-widths could be used.
In a traditional binary multiplier approach, each bit of the multiplier is multiplied against the multiplicand and positioned according to the position of the bit within the multiplier, and the resulting products are then summed to form the final result.
Using A and B, this would be:
                                                                        S                                                                                1                            =                                                                                S                                                                                2                            =                                                                                A                                                                                2                                                                                A                                                                                1                                                                                A                                                                                0                                                                                ×                                                                                B                                                                                1                                                                                B                                                                                0                                                                                A                                                                                2                  ·                  B                                                                                0                                                                    A                                                                                1                  ·                  B                                                                                0                                                                    A                                                                                0                  ·                  B                                                                                0                                                                                A                                                                                2                  ·                  B                                                                                1                                                                    A                                                                                1                  ·                  B                                                                                1                                                                    A                                                                                0                  ·                  B                                                                                1                                                                                }      Partial              Sums
Where the final result of A·B=S1+S2 and the result is a 5-bit binary number that is then fed into a digital to analog converter (DAC) circuit.
FIG. 1 depicts a block diagram 100 of a known multiplication method. As described above, it computes partial sums 105, adds S1 and S2 110 to provide a 5-bit input to 5-bit binary DAC 115. Binary 5-bit DAC 115 has weights of 1, 2, 4, 8, and 16, denoted below by DAC1, DAC2, DAC4, DAC8, and DAC16. The resulting logic equations needed to drive the DAC are:DAC1=A0*B0DAC2=(A1*B0){circle around (+)}(A0*B1)DAC4=((A1·B0)·(A0·B1)){circle around (+)}(A2·B0){circle around (+)}(A1·B1)DAC8=((((A1·B0)·(A0·B1))·((A2·B0)+(A1·B1)))+((A2·B0)+(A1·B1))){circle around (+)}(A2·B1)DAC16=(((((A1·B0)·(A0·B1))·((A2·B0)+(A1·B1)))+((A2·B0)+(A1·B1))·(A2B1)
A large number of gates is involved in the complex logic required to compute this result. This leads to high power consumption and large propagation delay which can decrease speed or necessitate pipelining.
RTZ
The use of return to zero (RTZ) in digital to analog converter (DAC) circuits is a method for doubling the null frequency of sin(x)/x roll-off inherent in DACs. RTZ also helps to reduce switching glitches in the DAC output. Typical approaches return to zero for differential outputs, but return to a rail for single-ended outputs. This introduces a common mode noise signal which can not be totally eliminated in a differential receiver due to practical common mode rejection ratio (CMRR) characteristics. The approach also lends itself to a long worst case slew rate.
In practice, the RTZ is implemented by switching current away from the DAC summing junction.
FIG. 6 is a schematic 600 of the typical known prior art DAC current switch. When NRZ (not return to zero) is high, the current is steered through one of the resistors based on the state of bitp/bitn, so the output voltage at outp/outn is either 0 volts or −I*RV (assuming the top rail is ground, although it could be at any arbitrary voltage). When RTZ is high, the current will not be steered through either resistor, so the both sides of the output are at 0 volts.
FIG. 7 displays a graph 700 of a typical prior art single-ended RTZ DAC output 705 of a sine-wave 710 for the switch of FIG. 6. While the typical RTZ differentially returns to zero, single-endedly it returns to a rail. This approach has a long slew rate when returning to zero from an output at the bottom rail. A true return to zero would return to the midpoint of the DAC output range.
What is needed is a method and apparatus for enhanced DAC performance through improved spurious free dynamic range (SFDR) and accurate return to zero (RTZ) performance.

Multiplying-adding return to zero digital to analog converter circuit and method

BAE Systems Information and Electronic Systems Integration Inc.


Described is a novel screening method for detecting an abnormal platelet condition in blood, and a kit for use in such a method. An initial screen for an abnormal platelet condition in blood applies to a non-interfering test surface a platelet rich plasma specimen from the blood and an aqueous reagent including a hydroxy-substituted aromatic compound such as elagic acid, tannin or preferably propyl gallate and a metal ion such as Ni.sup.2+, Co.sup.2+, Fe.sup.3+, Cu.sup.+ or Cu.sup.2+ in concentrations sufficient to cause platelet aggregation in a normal platelet rich plasma sample upon agitation, lightly agitating the platelet rich plasma specimen in contact with the reagent, and visually detecting for the presence of platelet aggregates in the specimen.

The present invention resides in the field of assays to determine the capacity of blood platelets to aggregate.
Although the causes of abnormal blood clotting are many, one cause which has been of particular importance is an abnormal platelet condition which renders the platelets unable to aggregate, a phenomenon essential to normal clotting. This abnormal platelet condition can be either a deficiency in the number of platelets in the patient's blood, or a defect in the platelets.
As an example, it has been discovered that full-term pregnancy pre-eclamptic women often have prolonged bleeding times. This has been attributed to low platelet counts, and also in some instances is thought to be due to abnormalities in platelets. See, J. Ramanathan et al., Anesthesiol., 1989, 71, 188-91. Additionally, in the area of quality control, a recent article points up the need for a sensitive test which can be used to differentiate platelet concentrates which retain functional integrity after storage from those which do not, and explains that there is presently no available method for accomplishing this. T. Hervig et al., Clin. Chem., 1990, 36, No. 1, pp. 28 -31.
Prior known and used tests for screening for abnormal platelet conditions are expensive and complicated. For example, the test currently used clinically is known as a platelet aggregation test. Generally, this test is performed by using expensive reagents such as ristocetin, collagen, adenosine diphosphate, or other reagents. Since these reagents work poorly, a sensitive optical instrument is used to follow the reaction. These tests, because of their inherent insensitivity, yield little clinically useful results. Needless to say, this test is not only costly, but also time consuming. Moreover, it cannot be conducted in the physician's office, necessitating sending samples to specialized laboratories for testing.
What is therefore needed is an initial screen test for determining the capacity of a patient's platelets to aggregate which is simple, inexpensive, and which can be conducted rapidly in a physician's office. Depending on the outcome of this initial screen, further, more quantitative testing for platelet aggregation may or may not be indicated. The present invention addresses this need.

Kit for an initial screen for abnormal platelet condition comprising propyl gallate or tannin and a metal ion