Abstract: The present invention provides a vascular conduit device including a deformable flange and complementary securing ring in cooperation for securing the device within an aperture defined in a tissue wall. The present invention further provides a system for implanting such a vascular conduit device in a tissue wall. More specifically, the present invention provides a system including a coring device for defining an aperture in a tissue wall (such as a ventricle and/or a blood vessel) and securely implanting a vascular conduit device therein so as to provide fluid communication between a first and second surface of the tissue wall via the vascular conduit device.

Abstract: Certain novel heterocyclic compounds, aromatic thioesters, their preparation, and their use in inhibiting serine proteases with chymotrypsin-like and elastase-like specificity and in the treatment of diseases such as emphysema which involve tissue proteolysis.

Abstract: An apparatus and method are disclosed which employ the Doppler principle to measure the terminal velocity and, hence, the size distribution of hydrometeors such as raindrops and hailstones. The apparatus of the present invention employs a ground-based, upwardly directed, low power, 10.525 GHz homodyne continuous wave radar module to transmit microwave signals to falling hydrometeors within the size range of 0.5 mm through 4.0 cm, to record the frequency distribution and power spectrum of the reflected signals, and to process these data with "terminal velocity"-to-"hydrometeor diameter" calibration data to generate information on the hydrometeor size distribution in the precipitation under observation. The disclosed method permits a user of the apparatus to select the Doppler velocity threshold above which data are recorded for processing with a Fast Fourier Transform technique to determine hydrometer velocity values.

Abstract: A system for identification and quantification of electrochemically active compounds in a flow stream involves stepping the electrode potential in a detector rapidly through the range of interest with a square wave superimposed on a staircase signal and recording the current response as functions of step number and sweep number, i.e., as functions of voltage and time. From the recorded data, a three-dimensional graph (potential, time and current) is structured and from which identification and quantification of the electrochemically active compounds is effected with minimum expenditure of time. The system includes a potentiostat controlled by a computer with, however, independent logic control contained in the potentiostat. Provision is also made to compensate automatically for variations in resistance between the cell electrodes.

Abstract: A method and apparatus for producing and viewing stereoscopic images through the use of a color coded image whereby the desired depth or distance is based upon the color of the portion of the image being viewed. Therefore the parts of the image which are to appear distant are colored red whereas the parts of the image to appear in the foreground are colored blue with the middle ground or intermediate distances being colored green or yellow. The color coded image is viewed through a prism glass constructed so that blue light which passes through the prism is bent toward a sharper angle than red light. Because the apex of the prism before each eye points toward the nose or center of the glasses the eyes must then turn more inward to see a blue object than to see a red object even though they are in actuality in the same plane on the display.

Abstract: Certain novel heterocyclic compounds, aromatic thioesters, their preparation, and their use in inhibiting serine proteases with chymotrypsin-like and elastase-like specificity and in the treatment of diseases such as emphysema which involve tissue proteolysis.

Abstract: The interfacial tension in a liquid-liquid system is determined by estimating the flow rate of the heavier liquid as it is discharged under constant head through a capillary immersed in a body of the lighter liquid. A known voltage is applied to each drop which forms at and detaches from the capillary tip and an electrometer is used to measure the total electrical charge per drop and the frequency of drop formation/detachment. The determination is made under conditions in which a plot of interfacial tension versus the square of the applied voltages yields two straight lines whose slopes of .+-.C/2 where C is the capacitance of the interface per unit area and the positive value is generated from the positive polarity voltage and the negative from the negative polarity.

Abstract: Spent catalysts containing metal impurities are treated by a process comprising treating the spent catalyst with a solution containing oxidizing ferric ion and/or oxidizing bacteria, thereby freeing said spent catalyst of said metal impurities.

Abstract: A process for the purification of terephthalic acid comprising (1) contacting an impure terephthalic acid with an amount of supercritical fluid, at a temperature and pressure, and for a period of time, sufficient to dissolve the terephthalic acid and its impurities in said supercritical fluid and (2) allowing said solution of terephthalic acid and impurities in supercritical fluid to expand into a reaction chamber, whereby the supercritical fluid becomes gaseous and the terephthalic acid, freed of impurities, precipitates out as a solid.

Abstract: A four-quadrant NMOS transconductance multiplier including plural NMOS transistors formed in a substrate to produce a pair of summer stages and a pair of squaring stages which process a pair of input signals V.sub.1, V.sub.2 to produce an output signal V.sub.o according to the quarter-square algebraic identity,V.sub.o =1/4[(V.sub.1 +V.sub.2).sup.2 -(V.sub.1 -V.sub.2).sup.2 ]=V.sub.1 V.sub.2.In a preferred embodiment, the substrate doping N.sub.A =6.7.times.10.sup.15 cm.sup.-3 and the channel width and channel length of each of the NMOS transistors forming the summer and squaring stages is greater than 10 .mu.m.

Abstract: The customary side hand propulsion ring adjacent to each main wheel of a manual wheelchair is mounted through a lost motion connection between the propulsion ring and main wheel so that the propulsion ring can have limited rotational movement relative to the main wheel. A friction brake drum or partial drum fixed to the wheelchair frame inside of the main wheel is engaged by at least one of a plurality of circumferentially spaced over center friction locking devices pivotally held on the main wheel. Each over center friction locking device is moved by a release element to a non-locking position relative to the drum or partial drum in response to reverse movement of the propulsion ring by a chair occupant. Economy and ease of operation are provided for. The wheelchair occupant need not remove his or her hand from the propulsion ring when operating the anti-rollback mechanism.

Abstract: To substantially reduce the physical effort required to slow or stop a manually propelled wheelchair, the customary propulsion ring attached to the outer side of each main chair wheel is mounted on the wheel for limited inward axial movement under manual pressure and is biased outwardly by spring force. A brake ring of similar diameter near the interior side of each wheel in a plane parallel to the plane occupied by the propulsion ring is connected directly with the propulsion ring. An opposing friction brake shoe attached to the chair frame is engaged by the brake ring to slow or stop the chair whenever the chair occupant pushes the propulsion ring axially inwardly.

Abstract: A pulse combustor apparatus including a combustor tube having open ends and containing at least one combustion zone where combustion of a fuel occurs and heat is released, resulting in the formation of a standing acoustic mode with nodes and anti-nodes in the tube. The combustion zone is located approximately half the distance between the acoustic pressure node and anti-node where the acoustic pressure oscillation lags the acoustic velocity oscillation by approximately one-quarter wavelength of the oscillation. Furthermore, the combustion air must flow towards the acoustic pressure anti-node. The fundamental principle relating to the occurrence of the pulsations in the combustor is the interaction between the combustion processes and both the non-zero acoustic velocity and acoustic pressure oscillations at the designated combustion zone location.

Abstract: A radio frequency interferometer/Doppler target location system comprising in one embodiment a wave source on a target vehicle which is tracked by a radio frequency interferometer located at a known situs. The radio frequency interferometer generates signals representing the azimuth angle, elevational angle and Doppler shift of the source. The Doppler shift is a direct measurement of the velocity of the target vehicle in wavelengths per second and therefore if the Doppler cycles are counted from the time the target vehicle is launched, its range can be determined at any desired time. The azimuth angle signal, elevation angle signal and the Doppler shift signal are then transmitted to a processor where the information is converted into any desired format to indicate the position of the tracked vehicle.

Abstract: Biomass feedstock raw material is converted to synthesis gas by drying and sizing biomass raw material, pyrolyzing the processed biomass in intimate mixture with inert gases such as combustion products, thereby obtaining a product mixture of char, pyrolysis oil, and pyrolysis gas, and gasifying the char and some of the pyrolysis oil in the presence of steam and oxygen at a temperature sufficient to form the synthesis gas product substantially comprising carbon monoxide and hydrogen.

Abstract: A self-propelled aeration device comprising a jet-aerator mounted on floats and connected by a hinged arm to a central pile for enabling the said aerator to rotate around the pile thus mixing and aerating both the large surface and great depth of a reservoir. As the jet-aerator a weir or orifice, preferably tooth-shaped orifice, are employed. In order to reduce the obstruction of jets and the wind resistance most of the elements of the floating structure are combined in a central box. The said box is self-supporting on water so that only small balancing floats are needed in addition to the central box in order to provide the stability of the floating structure. The device has provisions for preventing icing and clogging.

Abstract: Packing for fluidized bed reactors, is improved by providing alternately inclined baffles connected directly to each other or by means for connecting the said baffles into grids located in one or several levels, the said baffles forming expanding and contracting cells in the direction of the flow. The size, spacing in grids and the angle of attack of these baffles and spacing of grids are the same throughout the reactor volume when uniform distributions of the fluidizing agent and the fluidized medium are required. Alternatively, a device of this type is improved by providing variable sizes, spacing in grids, and angle of attack of these baffles and spacing of grids when specified nonuniform distributions of the flow of the fluidizing agent and the concentrations of the fluidized media are desired for particular applications.

Abstract: A method of recovering by distillation the separate components of a hydrocarbon gas mixture comprising ethylene, ethane, propylene and propane which comprises separating the ethylene and ethane as an overhead from a propylene and propane bottom in a first distillation tower at from about 400 to about 600 psia, separating ethylene and ethane as an ethylene overhead and an ethane bottom in a second distillation tower at from about 600 to about 700 psia, and separating propylene as an overhead from a propane bottom in a third distillation tower at from about 280 to about 300 psia is disclosed.

Abstract: The propulsion wheels of a manually propelled wheelchair are equipped with one-way engaging and one-way freewheeling clutch devices which cooperate with races fixed to the wheelchair frame, whereby unwanted backward movement of the wheelchair is prevented and forward movement at all times is enabled. An override mechanism including a spider attached to each hand propulsion ring disables the one-way engaging clutch devices when the wheelchair occupant intentionally moves the propulsion wheels in a backward mode. No controls separate from the manual propulsion wheels are present, assuring the chair occupant constant control of the chair through the hand propulsion rings at all times.

Abstract: A method of recovering by distillation the separate components of a hydrocarbon gas mixture comprising ethylene, ethane, propylene and propane which comprises separating the ethylene as an overhead from an ethane, propylene and propane bottom in a first distillation tower at from about 500 to about 650 psia, separating ethane as an overhead from a propylene and propane bottom in a second distillation tower at from about 390 to about 520 psia, and separating propylene as an overhead from a propane bottom in a third distillation tower at from about 100 to about 170 psia is disclosed.A method of separating ethylene and ethane from propylene and propane in a first distillation tower at from about 400 to about 600 psia, separating the overhead product from the first tower in a second tower at from about 600 to about 700 psia to produce ethylene and ethane products, and separating a propylene/propane mixture in a third tower at from about 100 to about 170 psia is disclosed.