Distribution Manifold Research Articles

Quadri-directional Air Thrusters for Free-floating Robot Applications

This paper describes the operational theory and design of a quadri-directional air thruster ( “quad” ) for propulsion of the free-floating robot of Ohio University. In this design, the air is drawn from a central air tank and routed to four nozzles of a quad thruster via a pressure regulator, a distribution manifold, four solenoid valves, and a quad manifold. The pressure regulator is controlled by a d.c. servomotor and the solenoid valves are turned on/off using the digital output ports of the computer. The performance characteristics of this quad thruster were determined experimentally. The experimental measurement of the thrust as a function of the regulated pressure shows a good match with the data predicted by the supporting theory.

A Low-Cost Recirculation System Using Disposable Beverage Containers

Abstract A tank system with recirculating water designed for use with disposable plastic 3-L beverage bottles is described. The system consisted of 100 culture units (2-L working volume in each), five 40-L tanks, and an upwelling biofilter. The 40-L tanks were used to increase the total volume of the system, to allow operation of the filter when bottles were not occupied, and for temporary storage of fish when treatments were pooled following screening. Each bottle received water from a common distribution manifold, and flow was adjustable from 0 to I L/min (0–30 water changes per hour). Bottles could be removed easily for replacement or to facilitate study of fish. The system was designed to allow separation of treatments for genetic studies, but would be useful for experiments requiring replication of treatments or experimental units with minimal environmental variation.

A Low Velocity Wind Tunnel to Evaluate Inhalability and Sampler Performance for Large Dust Particles

Abstract Workers in occupations such as mining, wood working, spray painting, pesticide application, and metal grinding are exposed to large particles in the 10 to 150-μm particle size range. For sampling large particles such as these, the American Conference of Governmental Industrial Hygienists has recently adopted criteria for inhalable particulate mass (IPM) sampling. Measurements of inhalability and IPM sampler performance are sensitive to the direction and velocity of the ambient air motion as well as particle size. Because of the complex flow field around a person, these measurements are best made under simulated industrial conditions in a large, low velocity wind tunnel where particle size, wind velocity, and direction can be carefully controlled. An 11,000 ft3/min, open-cycle, closed-jet wind tunnel with a cross-section of 1.6 × 1.6 m has been constructed for IPM studies. It can produce wind velocities from less than 0.1 to 2 m/s (20 to 390 ft/min). It can accommodate a full-torso mannequin. The mannequin has been modified to collect the dust entering the nose or mouth. It can rotate at 0.1 to 1 rpm and is connected to a mechanical breathing machine to simulate human breathing over the usual range of work rates. Three gear-feed, aspirating dust feeders deliver narrow-distribution aluminum oxide dust to a reciprocating dust distribution manifold. A wooden lattice induces controlled turbulence in the test section. Turbulence intensity from 3 to 14 percent can be produced. Air velocity is uniform within 10 percent and dust concentration is uniform to within 15 percent at the test section. The tunnel meets the European Economic Community's guidelines for testing indoor IPM samplers and shows good performance over the particle size range of 10 to 145 μm.

5360556 Method of feeding wastewater effluent to filter bed through parallel conduits

An on-site wastewater treatment system distributes septic tank effluent over a particulate media filter bed through a distribution manifold at a sufficient volumetric flow rate relative to the cross-sectional area of the distribution conduits to inhibit undesirable biological growth in the conduits and in the filter by creating a scouring effect in the conduits. This effect prevents clogging of the conduits and maximizes the even distribution of effluent in the filter. A mesh fabric intercepts the downward flow of the effluent in the filter to further aid in the even distribution of effluent in the filter. Orifice shields also aid in such distribution by preventing clogging of orifices embedded in the filter media. A high pressure switch in the distribution manifold and a high water alarm in the filter pump basin indicate when required maintenance is necessary, and the switch controlling the high water alarm temporarily disables the septic tank pump as well. A flush system is provided to easily remove any clogging solid material from the distribution manifold.

Elemental vapor transport epitaxy of II-VI semiconductors

Molecular beam epitaxy (MBE) is an advanced deposition technique known to produce high quality semiconductor films and structures. While great progress has been achieved in recent years, MBE still suffers from problems with elemental flux control which include: flux instabilities, long respoNSe times, significant transients, and difficulty of scaling to large area depositions. The elemental vapor transport epitaxy (EVTE) technique was formulated to resolve several problems typically accompanying conventional MBE. In EVTE, the vapor sources feed through regulating valves into a common flux distribution manifold that is located below the inverted wafer. We previously reported the EVTE growth of GaAs without gallium source related oval defects. In this paper, we report on EVTE deposition of the ZnSe, ZnTe, CdSe, CdTe, and ZnTe-ZnSe on GaAs (100) substrates. We have achieved selenium elemental flux control with respoNSe times less than one second and deposited films thickness uniformity ± 1.8% over a 2.0″substrate. Elemental vapor transport epitaxy grown materials show good surface morphology and stoichiometry, sharp interface, and low outdiffusion from the substrate. X-ray analysis showed crystallinity (FWHM = 95 arcsec) of the ZnSe films.

One Year Full-Scale Study Of Ozone Cooling Water Treatment At A German Electric Power Station

This paper presents operating results of ozone treatment of the water in a cooling system with open loop recycling containing the following elements: Main cooling water pumps - Cooling water storage tanks - Distribution manifold to cooling water users - Cooling water collecting basins - Cooling water recycling pumps - Cooling tower. The system reviewed in this paper is the side cooling system of a heating power station in Germany, with a capacity of 1,000 m[sup 3]/h (4,400 US gpm). Operation started in early 1989. The plant has been operating now for over two (2) years. During this period the following items were analyzed and evaluated: Ozone residual in the water - Quality of the cooling water - Organic scaling on equipment and piping - Material corrosion behavior. For the purpose of analyzing the corrosion behavior, two heat exchangers were installed, both identical and each fitted with tubes of different materials. One unit was in contact with ozone residual, while the other was exposed to water without ozone. The results of this two year operation are extremely encouraging and the owner of the power plant decided to keep the ozone system operating for the future. 3 refs., 7 figs., 1more » tab.« less

Uniformity Control in Elemental Vapor Transport Epitaxy

ABSTRACTElemental Vapor Transport Epitaxy (EVTE) is a novel technique for semiconductor manufacturing, which combines the advantages of Molecular Beam Epitaxy (MBE) and Vapor Phase Epitaxy (VPE). EVTE provides a high level of elemental flux control, scaling to large deposition areas, and elimination of elemental Ga source related oval defects. EVTE has been successfully applied to the deposition of III-V and II-VI thin films and heterostructures. Design considerations and evaluations of the novel EVTE elements: elemental flux regulating valve operating at temperatures >1250°C with demonstrated response times less than 1 second and elemental flux distribution manifold are presented. The calculated operational parameters for EVTE are in good agreement with the observed experimental results.

Design of a Semi-Liquid Dairy Cattle Manure Spreader/Injector

Existing solid and liquid manure spreaders are not well adapted for surface spreading or direct subsurface injection of semi-liquid dairy cattle manure. By taking into account the characteristics of this type of manure, a machine for either spreading or injecting semi-liquid manure was designed and constructed. Its manure handling system consisted of a tiltable tank connected to a vibrating distribution manifold that directed the manure to the spreading or injection devices. Manure was fed to the injectors by gravity via 152 mm (6 in.) diameter hoses. The 305 mm (12 in.) wide injectors were operated at depths not exceeding 203 mm (8 in.) in order to reduce draft requirements. Results from preliminary field testing of the prototype are reported along with the design modifications that were recommended following these tests.

HYDRAULIC JET PUMPING AT TINTABURRA OILFIELD

The Hutton zone of the Tintaburra oilfield has an active bottom water drive which necessitates high gross fluid production rates to enable reserves to be produced within a reasonable period of time. A high volume artificial lift system capable of producing 8 000 to 10 000 barrels of fluid per day (BFPD) from 6 producing wells formed the basic design criteria, and hydraulic jet pumping was chosen as the means of artificial lift. The hydraulic jet pumping installation at Tintaburra was the first of its kind in Australia.The basic principle of operation of a jet pump is the transfer of momentum from a power fluid to reservoir fluid. The power fluid is pumped through a nozzle and the corresponding increase in velocity results in a pressure drop at the nozzle exit. This drop in pressure provides the drawdown necessary to move reservoir fluid to the pump where it is entrained and mixed with the power fluid. The combined stream is produced to surface and handled using convential production techniques. Equipment required in the Tintaburra system consists of a power fluid settling and storage tank, surface power fluid pump, distribution manifold, wellhead control valves and the subsurface assembly, including the jet pump itself.The application of mathematical equations describing jet pump operation was used in the initial selection of pumps for the Tintaburra wells. While this method provides insight into the operation of jet pumps, the use of equipment supplier's software proved to be more expedient in the final design stages and allowed many nozzle and throat combinations to be evaluated. Changes to well productivity brought about by the installation of down hole equipment required new pump selections for all wells. After nine months of operation, comprehensive production testing again highlighted changes to well productivity, necessitating variations in operating parameters or, in some cases, specification of new pumps.

GaP and GaAs films grown by vacuum chemical epitaxy using TEGa and TMGa sources

We have previously described a hybrid MBE/MOCVD growth technique in which organometallic vapors are injected into a high vacuum system to grow III–V epitaxial films. In our process, called vacuum-chemical-epitaxy (VCE), multiple group(III)-alkyl molecular beams are directed onto wafers from a water cooled gas distribution manifold providing for the growth of uniform films over large areas with high group(III)-alkyl utilization efficiency. The group(V) source, on the other hand, is injected at a single point on one side of the deposition zone. The group(V) molecules are confined and undergo molecular flow across the deposition zone. The utilization efficiency of the Group(V) source material can be enhanced by the use of a thermal cracker at the point of group(V) gas injection. We have previously described the growth of high purity epitaxial GaAs films using triethygallium (TEGa) in a VCE reactor. In this paper, we describe the growth of GaP films using TEGa and trimethylgallium (TMGa) in VCE. Data are also presented on the effect of the thermal cracker temperature on PH 3 cracking efficiency and on GaAsP film composition. Finally, the properties of GaAs films grown using TMGa will be described. In particular, it is noted that TMGa can be used as a source of carbon doping for p-type GaAs films and that these carbon doped films can be incorporated in solar cells yielding devices with high quantum yields.

Anode assembly for electroforming record matrixes

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Preparation of titanium nitride by a pulsed d.c. magnetron reactive deposition techniques using the moving mode of deposition

The interest in titanium nitride films has been growing rapidly for use both as protective coatings and more recently as a decorative coating to provide a substitute for gold with its escalating costs. High rate d.c. magnetron deposition was investigated for this purpose as it was expected to provide the lowest cost and highest throughput. Difficulty was encountered in maintaining a constant partial pressure of nitrogen. The addition of a gas distribution manifold and the pulsing of the nitrogen gas solved this problem. Nitride sputtering rates were obtained that were 70% of the pure metal rate. Protective coatings 1 μm thick had a hardness of 1200 kgf mm −2. Decorative coatings which ranged in color from light gold to bronze and which were resistant to abraison and corrosion were deposited.