Abstract: A multilayered insulated mold structure is provided. An insulation layer provided on each of the mold cores retains heat at the molding surface, thereby increasing surface quality of the finished part. The insulating layer has a varying density across its thickness so as to have a low density center region and high density surface regions. By having a relatively low denisty, the center region of the insulating layer has a low thermal conductivity. Thus, the insulating layer may be made from the same material as the core and still have an acceptable insulating value. The use of the same material for adjacent layers reduces the potential of delamination of the layers. The multilayered mold is compatible with passive or active heating of the molding surface.

Abstract: The detection of sound emitted from a source in a dynamic environment of ambient background noise employs a sufficiently distributed array of sound intensity probes enclosing a sound source is adapted to collect measurements over the same time interval in a non-specific acoustic environment. Each probe in the array is comprised of a pair of mutually spaced microphones generally unmatched in their gain and phase response. A multi-channel fourier spectrum analyzer is used to provide a direct signal processing determination of sound intensity at each probe from pressure measurements taken at each microphone. Their computation is corrected to compensate for gain and phase mismatch between each microphone pair using independently derived probe calibration factors. These correction factors are linearly applied to the sound intensity determination at each probe of the array.

Abstract: A heat transfer arrangement for a refrigeration circuit is described. In one embodiment and for a refrigeration circuit including compressor means, a plurality of evaporator means coupled to the compressor means, one of the evaporator means being arranged to operate at a temperature lower than the operating temperature of the other evaporator means, the present heat transfer arrangement comprises a first conduit means coupled to the outlet of the one evaporator means, the first conduit means being at least partially disposed in a heat transfer arrangement with at least a portion of a second conduit means coupled to the inlet of the one evaporator means.

Abstract: A refrigerator apparatus is provided having a cabinet with a freezer compartment and a fresh food compartment. The compartments define two passageways allowing air circulation therebetween. A refrigerator system is included having a compressor, a condenser, an expansion valve, an evaporator situated in the freezer compartment. The refrigerator system elements are connected in series in a closed loop, in a refrigerant flow relationship. A first fan is situated in the freezer compartment for providing air flow over the evaporator. A second fan is situated in one of the two passageways for providing air circulation between the two compartments. A first thermostatic controlller situated in the freezer compartment for maintaining a desired temperature in the freezer compartment by causing the compressor and the first fan to operate.

Abstract: A process for forming an expanded fiber composite structure. The process includes impregnating a fiber mat with a plastic material, compressing the mat to impregnate the mat with the plastic, fully wetting each fiber and creating a substantially void-free fiber/plastic matrix, and reducing the compressive forces on the mat, allowing the fibers to rebound and expand the mat to a predetermined desired thickness, in the process creating interstitial voids. The structure is then cooled such that the plastic material stiffens and itself retains the structure at the desired thickness. The process optionally employs the addition of a molten polymeric material to the expanded or lofted mat, the material filling the interstitial voids in the structure. A composite structure may optionally be produced from a fully compressed plastic-impregnated fiber mat by heating to a temperature sufficient to loft the material and controlling the amount of lofting after the heat is applied.

Abstract: A thermoplastic sheet is placed between a pair of mold members each having a thermal insulator and a mating metal mold insert. RF energy is applied to the inserts to dielectrically heat and melt the thermoplastic sheet. The heated sheet is then deformed in a low pressure press with the insulators. The insulators are then replaced with cool thermally conductive structures to shorten the cooling cycle time. The thermally conductive structures cool the sheet by pressing the sheet in a high pressure press.

Abstract: An excess liquid refrigerant accumulator for multievaporator refrigeration systems is provided. Under some operating conditions, the lowest temperature evaporator of a multievaporator system may discharge some liquid refrigerant rather than only vapor refrigerant. This liquid discharge creates a loss of cooling capacity. A receptacle connected to the exit of the lowest temperature evaporator accumulates the liquid. By locating the receptacle within the cooled compartment, the cooling capacity which would otherwise be lost, is regained.

Abstract: A process for forming a thermoplastic resin coating on glass fibers comprises heating a thermoplastic resin powder until molten and applying it to the glass fibers. The coated fibers can then be heated and drawn into a desired shape which also removes resin. Then the coated fibers are cooled to make a preform. The coated fiber preform can then be molded. Several resin layers with glass fibers of varying lengths can be deposited to make a graded preform. Apparatus for forming a thermoplastic resin on glass fibers sprays hot thermoplastic powder on the glass fibers. The coated fibers can then be heated such as by IR lamps and then drawn through a die which has a spigot to remove excess plastic. Alternately, a plurality of plastic and glass fiber layers can be deposited on a veil.

Abstract: A vacuum-assisted drying apparatus and method are provided for rapidly drying fabrics. A rotatable drum is enclosed in a nearly hermetic region. A valve is attached to an inlet of the region; a compressor is attached to an exit of the region. With the valve closed, the compressor reduces the pressure within the region to the saturated pressure of water at the temperature of the fabrics. At this point, free moisture in the fabrics evaporates. Continued operation of the compressor removes the vaporous moisture from the system. After most of the free water vapor has been depleted, the valve is opened to allow heated air to flow through the drum and to dry the remaining bound moisture.

Abstract: A V-shaped afterburner flameholder for a gas turbine engine has a plurality of rectangular tabs coextensive with and lying in the planes of the flameholder sidewalls. The tabs on opposing sidewalls alternate so as to introduce streamwise and spanwise (transverse) vortices in the flowing gas. The resultant streamwise vortices tend to reduce resonating vortex oscillations (screech) and the need for an acoustic liner to suppress such screech.

Abstract: A calibrator and the derivation of an associated calibration data base for computationally compensating for gain and phase mismatch in sound intensity probes comprised of two unmatched pressure transducing microphones is described herein. The calibrator utilizes a unique `phase plug` to maintain temporal uniformity (in addition to standard spatial uniformity) in the sound field of the calibration chamber. Gain and phase calibration factors are independently obtained for each probe of interest using the calibrator and these data are compiled into an independent data base for storage and subsequent application. Such linear correction factors as applied to associated signal processing of probe measurements serves to computationally compensate for phase mismatch between the unmatched microphone pair.

Abstract: An electrical motor with integral silencer is provided having a motor housing defining an inlet aperture at one end and an expansion chamber at the other end. The expansion chamber has a reduced cross-sectional area at the entrance and exit of the expansion chamber compared to the cross-sectional area of the chamber. The exit of the expansion chamber provides an outlet aperture in the housing. A stator is situated in the housing and a rotor is rotatably mounted within the stator. A fan is secured to the rotor and rotates therewith for pulling air in the outlet aperture through the stator and exhausting the air through the expansion chamber to the housing exterior. The expansion chamber provides an impedance mismatch for the acoustic energy generated by the fan preventing a portion of the acoustic energy from exiting the expansion chamber.

Abstract: A metal mold core which is partially insulated includes a metal continuous hard skin layer over the core and over the insulation to avoid discontinuity caused delamination in the presence of flowing injected plastic. The skin layer includes abrasion resistant nickel deposited over electroytically and electrolessly deposited copper applied over an interface metal layer on the core. The insulation layer includes multiple layers of a polyimide resin one of which layers includes glass micro spheres for decreasing the thermal conductivity to increase its insulation property and for decreasing the coefficient of thermal expansion (CTE) of the insulation to more closely match the core CTE to further preclude delamination in the presence of temperature excursions.

Abstract: A refrigerator apparatus is provided having a cabinet with a freezer compartment and a fresh food compartment. The compartments define two passageways allowing air circulation therebetween. A refrigerator system is included having a compressor, a condenser, an expansion valve, an evaporator situated in the freezer compartment. The refrigerator system elements are connected in series in a closed loop, in a refrigerant flow relationship. A first fan is situated in the freezer compartment for providing air flow over the evaporator. A second fan is situated in one of the two passageways for providing air circulation between the two compartments. A first thermostatic controller situated in the freezer compartment for maintaining a desired temperature in the freezer compartment by causing the compressor and the first fan to operate.

Abstract: A fuel with or without fuel bound nitrogen (FBN) is burned in a high pressure machine (20 atm) comprising fuel and air compressors, combustor and turbine at an ER of about 2-3 and temperature below the threshold for creating thermal NO.sub.x. Prompt and FBN NO.sub.x are avoided due to the rich mixture, having a dearth of O and OH, producing CO and H.sub.2 and little CH. The turbine cools the products to reduce their temperature. The cooled products are mixed with the remaining air and burned at a temperature below the thermal NO.sub.x threshold temperature at an ER of about 0.6. Commercial stand alone machines can be used for the rich and for the lean combustors wherein air and fuel are supplied to the rich combustor and only air and the cooled combustion products of the rich machine are supplied to the lean combustor.

Abstract: A refrigeration system suitable for use in household refrigerators having a fresh food compartment, a freezer compartment and an intermediate temperature compartment is provided. The system includes a first expansion throttle, a first evaporator for providing cooling to a freezer compartment, first, second and third compressors, a condenser, a second expansion throttle, a second evaporator for providing cooling to a fresh food compartment, a third expansion throttle, and a third evaporator for providing cooling to an intermediate compartment. All the above elements are connected in series, in that order, in a refrigerant flow relationship. A first phase separator connects the second evaporator to the third expansion throttle in a refrigerant flow relationship and provides intercooling between the second and third compressors.

Abstract: Apparatus for heating a plastic sheet uses a high dielectric constant material (HDCM) to shape an RF electric field to be either concentrated or uniform as desired depending upon the object to be formed from the sheet. Electrodes can be annular with a circular or elliptical cross-section or be plates or wires, and can be disposed in the HDCM or exterior of the HDCM. A process for heating a plastic material comprises generating an RF field and shaping the field near the material using high dielectric constant members.

Abstract: An afterburner flameholder for a gas turbine engine having a central diffuser cone, a generally cylindrical outer shell and fuel spray bars between the shell and cone defining an afterburner region is provided, which comprise an annular member with an asymmetric V-shaped cross section. The annular member is adapted to be secured to the engine in the afterburner region with the apex of the V facing upstream in the axial direction toward the fuel spray bars. The annular member has a first and second circular sidewall member each joined at one end forming an apex, the annular member in cross section has unequal length sidewall members. The difference in length between the distal ends of the first and second circular sidewall members is sufficient to cause spanwise vortices shed at the distal ends of the sidewall members to be out of phase when they meet downstream from the flameholder.

Abstract: A dielectric mold member has different thicknesses producing different radio frequency (RF) voltage drops thereacross. An RF electrode is spaced differently from a thermoplastic sheet to be dielectrically heated by the RF energy such that in one implementation the sheet receives uniform potentials and is heated uniformly. In other implementations, the sheet can receive selectively controlled heating over different regions. In an alternative embodiment, multiple pairs of electrodes apply different RF field levels to different portions of the thermoplastic sheet to compensate for the different voltage drops due to different mold thicknesses or to applied different controlled heating levels to different regions.

Abstract: A mold structure including layers with different physical properties is used to provide hot surface during molding. The use of a thin layer of low thermal conductivity covered by a smooth skin layer prevents quick cooling of the surface of the pre-heated plastic to be molded. The plastic surface remains molten and flows to fill the mold during press closing, resulting in smooth surfaces even when fiber reinforced plastics are used.