Conceptual study of on orbit production of cryogenic propellants by water electrolysis

Science.gov (United States)

Moran, Matthew E.

1991-01-01

The feasibility is assessed of producing cryogenic propellants on orbit by water electrolysis in support of NASA's proposed Space Exploration Initiative (SEI) missions. Using this method, water launched into low earth orbit (LEO) would be split into gaseous hydrogen and oxygen by electrolysis in an orbiting propellant processor spacecraft. The resulting gases would then be liquified and stored in cryogenic tanks. Supplying liquid hydrogen and oxygen fuel to space vehicles by this technique has some possible advantages over conventional methods. The potential benefits are derived from the characteristics of water as a payload, and include reduced ground handling and launch risk, denser packaging, and reduced tankage and piping requirements. A conceptual design of a water processor was generated based on related previous studies, and contemporary or near term technologies required. Extensive development efforts would be required to adapt the various subsystems needed for the propellant processor for use in space. Based on the cumulative results, propellant production by on orbit water electrolysis for support of SEI missions is not recommended.

Cryogenic propellant management: Integration of design, performance and operational requirements

Science.gov (United States)

Worlund, A. L.; Jamieson, J. R., Jr.; Cole, T. W.; Lak, T. I.

1985-01-01

The integration of the design features of the Shuttle elements into a cryogenic propellant management system is described. The implementation and verification of the design/operational changes resulting from design deficiencies and/or element incompatibilities encountered subsequent to the critical design reviews are emphasized. Major topics include: subsystem designs to provide liquid oxygen (LO2) tank pressure stabilization, LO2 facility vent for ice prevention, liquid hydrogen (LH2) feedline high point bleed, pogo suppression on the Space Shuttle Main Engine (SSME), LO2 low level cutoff, Orbiter/engine propellant dump, and LO2 main feedline helium injection for geyser prevention.

Orbiting Depot and Reusable Lander for Lunar Transportation

Science.gov (United States)

Petro, Andrew

2009-01-01

A document describes a conceptual transportation system that would support exploratory visits by humans to locations dispersed across the surface of the Moon and provide transport of humans and cargo to sustain one or more permanent Lunar outpost. The system architecture reflects requirements to (1) minimize the amount of vehicle hardware that must be expended while maintaining high performance margins and (2) take advantage of emerging capabilities to produce propellants on the Moon while also enabling efficient operation using propellants transported from Earth. The system would include reusable single- stage lander spacecraft and a depot in a low orbit around the Moon. Each lander would have descent, landing, and ascent capabilities. A crew-taxi version of the lander would carry a pressurized crew module; a cargo version could carry a variety of cargo containers. The depot would serve as a facility for storage and for refueling with propellants delivered from Earth or propellants produced on the Moon. The depot could receive propellants and cargo sent from Earth on a variety of spacecraft. The depot could provide power and orbit maintenance for crew vehicles from Earth and could serve as a safe haven for lunar crews pending transport back to Earth.

Application of Model Based Prognostics to Pneumatic Valves in a Cryogenic Propellant Loading Testbed

Data.gov (United States)

National Aeronautics and Space Administration — Pneumatic-actuated valves are critical components in many applications, including cryogenic propellant loading for space operations. For these components, failures...

Computational Fluid Dynamics Based Extraction of Heat Transfer Coefficient in Cryogenic Propellant Tanks

Science.gov (United States)

Yang, H. Q.; West, Jeff

2015-01-01

Current reduced-order thermal model for cryogenic propellant tanks is based on correlations built for flat plates collected in the 1950's. The use of these correlations suffers from: inaccurate geometry representation; inaccurate gravity orientation; ambiguous length scale; and lack of detailed validation. The work presented under this task uses the first-principles based Computational Fluid Dynamics (CFD) technique to compute heat transfer from tank wall to the cryogenic fluids, and extracts and correlates the equivalent heat transfer coefficient to support reduced-order thermal model. The CFD tool was first validated against available experimental data and commonly used correlations for natural convection along a vertically heated wall. Good agreements between the present prediction and experimental data have been found for flows in laminar as well turbulent regimes. The convective heat transfer between tank wall and cryogenic propellant, and that between tank wall and ullage gas were then simulated. The results showed that commonly used heat transfer correlations for either vertical or horizontal plate over predict heat transfer rate for the cryogenic tank, in some cases by as much as one order of magnitude. A characteristic length scale has been defined that can correlate all heat transfer coefficients for different fill levels into a single curve. This curve can be used for the reduced-order heat transfer model analysis.

Numerical Modeling of Pressurization of Cryogenic Propellant Tank for Integrated Vehicle Fluid System

Science.gov (United States)

Majumdar, Alok K.; LeClair, Andre C.; Hedayat, Ali

2016-01-01

This paper presents a numerical model of pressurization of a cryogenic propellant tank for the Integrated Vehicle Fluid (IVF) system using the Generalized Fluid System Simulation Program (GFSSP). The IVF propulsion system, being developed by United Launch Alliance, uses boiloff propellants to drive thrusters for the reaction control system as well as to run internal combustion engines to develop power and drive compressors to pressurize propellant tanks. NASA Marshall Space Flight Center (MSFC) has been running tests to verify the functioning of the IVF system using a flight tank. GFSSP, a finite volume based flow network analysis software developed at MSFC, has been used to develop an integrated model of the tank and the pressurization system. This paper presents an iterative algorithm for converging the interface boundary conditions between different component models of a large system model. The model results have been compared with test data.

Fiber-Optic Continuous Liquid Sensor for Cryogenic Propellant Gauging

Science.gov (United States)

Xu. Wei

2010-01-01

An innovative fiber-optic sensor has been developed for low-thrust-level settled mass gauging with measurement uncertainty optical fiber to measure liquid level and liquid distribution of cryogenic propellants. Every point of the sensing fiber is a point sensor that not only distinguishes liquid and vapor, but also measures temperature. This sensor is able to determine the physical location of each point sensor with 1-mm spatial resolution. Acting as a continuous array of numerous liquid/vapor point sensors, the truly distributed optical sensing fiber can be installed in a propellant tank in the same manner as silicon diode point sensor stripes using only a single feedthrough to connect to an optical signal interrogation unit outside the tank. Either water or liquid nitrogen levels can be measured within 1-mm spatial resolution up to a distance of 70 meters from the optical interrogation unit. This liquid-level sensing technique was also compared to the pressure gauge measurement technique in water and liquid nitrogen contained in a vertical copper pipe with a reasonable degree of accuracy. It has been demonstrated that the sensor can measure liquid levels in multiple containers containing water or liquid nitrogen with one signal interrogation unit. The liquid levels measured by the multiple fiber sensors were consistent with those virtually measured by a ruler. The sensing performance of various optical fibers has been measured, and has demonstrated that they can survive after immersion at cryogenic temperatures. The fiber strength in liquid nitrogen has also been measured. Multiple water level tests were also conducted under various actual and theoretical vibration conditions, and demonstrated that the signal-to-noise ratio under these vibration conditions, insofar as it affects measurement accuracy, is manageable and robust enough for a wide variety of spacecraft applications. A simple solution has been developed to absorb optical energy at the termination of

Large Propellant Tank Cryo-Cooler (LPTC)

Data.gov (United States)

National Aeronautics and Space Administration — In rocket test and launch facilities, cryogenic propellants stored in tanks boils off due to heat leakage, with the following impacts:Ø   Waste, propellants boil off...

Cryogenic Fluid Management Technology for Moon and Mars Missions

Science.gov (United States)

Doherty, Michael P.; Gaby, Joseph D.; Salerno, Louis J.; Sutherlin, Steven G.

2010-01-01

In support of the U.S. Space Exploration Policy, focused cryogenic fluid management technology efforts are underway within the National Aeronautics and Space Administration. Under the auspices of the Exploration Technology Development Program, cryogenic fluid management technology efforts are being conducted by the Cryogenic Fluid Management Project. Cryogenic Fluid Management Project objectives are to develop storage, transfer, and handling technologies for cryogens to support high performance demands of lunar, and ultimately, Mars missions in the application areas of propulsion, surface systems, and Earth-based ground operations. The targeted use of cryogens and cryogenic technologies for these application areas is anticipated to significantly reduce propellant launch mass and required on-orbit margins, to reduce and even eliminate storage tank boil-off losses for long term missions, to economize ground pad storage and transfer operations, and to expand operational and architectural operations at destination. This paper organizes Cryogenic Fluid Management Project technology efforts according to Exploration Architecture target areas, and discusses the scope of trade studies, analytical modeling, and test efforts presently underway, as well as future plans, to address those target areas. The target areas are: liquid methane/liquid oxygen for propelling the Altair Lander Ascent Stage, liquid hydrogen/liquid oxygen for propelling the Altair Lander Descent Stage and Ares V Earth Departure Stage, liquefaction, zero boil-off, and propellant scavenging for Lunar Surface Systems, cold helium and zero boil-off technologies for Earth-Based Ground Operations, and architecture definition studies for long term storage and on-orbit transfer and pressurization of LH2, cryogenic Mars landing and ascent vehicles, and cryogenic production via in situ resource utilization on Mars.

To Ensure the Integrity of the Cryogenic Propellant Depot Tank Within the Expected Radiation and Space Debris Environment, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — HyPerComp Engineering, Inc. (HEI) proposes to develop well characterized, structurally reliable filament wound composite pressure vessels for use in both cryogenic...

Low-Cost Propellant Launch to LEO from a Tethered Balloon - 'Propulsion Depots' Not 'Propellant Depots'

Science.gov (United States)

Wilcox, Brian H.; Schneider, Evan G.; Vaughan, David A.; Hall, Jeffrey L.; Yu, Chi Yau

2011-01-01

As we have previously reported, it may be possible to launch payloads into low-Earth orbit (LEO) at a per-kilogram cost that is one to two orders of magnitude lower than current launch systems, using only a relatively small capital investment (comparable to a single large present-day launch). An attractive payload would be large quantities of high-performance chemical rocket propellant (e.g. Liquid Oxygen/Liquid Hydrogen (LO2/LH2)) that would greatly facilitate, if not enable, extensive exploration of the moon, Mars, and beyond.

Expandable Cryogenic Tankage for On Orbit Depot Storage, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — The proposed expandable depot storage tanks would make it possible to have an on-orbit tank larger in volume than any existing or planned launch vehicles. The size...

Shuttle APS propellant thermal conditioner study

Science.gov (United States)

Pearson, W. E.

1971-01-01

A study program was performed to allow selection of thermal conditioner assemblies for superheating O2 and H2 at supercritical pressures. The application was the auxiliary propulsion system (APS) for the space shuttle vehicle. The O2/H2 APS propellant feed system included propellant conditioners, of which the thermal conditioner assemblies were a part. Cryogens, pumped to pressures above critical, were directed to the thermal conditioner assembly included: (1) a gas generator assembly with ignition system and bipropellant valves, which burned superheated O2 and H2 at rich conditions; (2) a heat exchanger assembly for thermal conditioning of the cryogenic propellant; and (3) a dump nozzle for heat exchanger exhaust.

Liquid Hydrogen Propellant Tank Sub-Surface Pressurization with Gaseous Helium

Science.gov (United States)

Stephens, J. R.; Cartagena, W.

2015-01-01

A series of tests were conducted to evaluate the performance of a propellant tank pressurization system with the pressurant diffuser intentionally submerged beneath the surface of the liquid. Propellant tanks and pressurization systems are typically designed with the diffuser positioned to apply pressurant gas directly into the tank ullage space when the liquid propellant is settled. Space vehicles, and potentially propellant depots, may need to conduct tank pressurization operations in micro-gravity environments where the exact location of the liquid relative to the diffuser is not well understood. If the diffuser is positioned to supply pressurant gas directly to the tank ullage space when the propellant is settled, then it may become partially or completely submerged when the liquid becomes unsettled in a microgravity environment. In such case, the pressurization system performance will be adversely affected requiring additional pressurant mass and longer pressurization times. This series of tests compares and evaluates pressurization system performance using the conventional method of supplying pressurant gas directly to the propellant tank ullage, and then supplying pressurant gas beneath the liquid surface. The pressurization tests were conducted on the Engineering Development Unit (EDU) located at Test Stand 300 at NASA Marshall Space Flight Center (MSFC). EDU is a ground based Cryogenic Fluid Management (CFM) test article supported by Glenn Research Center (GRC) and MSFC. A 150 ft3 propellant tank was filled with liquid hydrogen (LH2). The pressurization system used regulated ambient helium (GHe) as a pressurant, a variable position valve to maintain flow rate, and two identical independent pressurant diffusers. The ullage diffuser was located in the forward end of the tank and was completely exposed to the tank ullage. The submerged diffuser was located in the aft end of the tank and was completely submerged when the tank liquid level was 10% or greater

Cryogenics Testbed Laboratory Flange Baseline Configuration

Science.gov (United States)

Acuna, Marie Lei Ysabel D.

2013-01-01

As an intern at Kennedy Space Center (KSC), I was involved in research for the Fluids and Propulsion Division of the NASA Engineering (NE) Directorate. I was immersed in the Integrated Ground Operations Demonstration Units (IGODU) project for the majority of my time at KSC, primarily with the Ground Operations Demonstration Unit Liquid Oxygen (GODU L02) branch of IGODU. This project was established to develop advancements in cryogenic systems as a part of KSC's Advanced Exploration Systems (AES) program. The vision of AES is to develop new approaches for human exploration, and operations in and beyond low Earth orbit. Advanced cryogenic systems are crucial to minimize the consumable losses of cryogenic propellants, develop higher performance launch vehicles, and decrease operations cost for future launch programs. During my internship, I conducted a flange torque tracking study that established a baseline configuration for the flanges in the Simulated Propellant Loading System (SPLS) at the KSC Cryogenics Test Laboratory (CTL) - the testing environment for GODU L02.

Innovative Swirl Injector for LOX and Hydrocarbon Propellants, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Gases trapped in the propellant feed lines of space-based rocket engines due to cryogenic propellant boil-off or pressurant ingestion can result in poor combustion...

Thermodynamic Vent System for an On-Orbit Cryogenic Reaction Control Engine

Science.gov (United States)

Hurlbert, Eric A.; Romig, Kris A.; Jimenez, Rafael; Flores, Sam

2012-01-01

A report discusses a cryogenic reaction control system (RCS) that integrates a Joule-Thompson (JT) device (expansion valve) and thermodynamic vent system (TVS) with a cryogenic distribution system to allow fine control of the propellant quality (subcooled liquid) during operation of the device. It enables zero-venting when coupled with an RCS engine. The proper attachment locations and sizing of the orifice are required with the propellant distribution line to facilitate line conditioning. During operations, system instrumentation was strategically installed along the distribution/TVS line assembly, and temperature control bands were identified. A sub-scale run tank, full-scale distribution line, open-loop TVS, and a combination of procured and custom-fabricated cryogenic components were used in the cryogenic RCS build-up. Simulated on-orbit activation and thruster firing profiles were performed to quantify system heat gain and evaluate the TVS s capability to maintain the required propellant conditions at the inlet to the engine valves. Test data determined that a small control valve, such as a piezoelectric, is optimal to provide continuously the required thermal control. The data obtained from testing has also assisted with the development of fluid and thermal models of an RCS to refine integrated cryogenic propulsion system designs. This system allows a liquid oxygenbased main propulsion and reaction control system for a spacecraft, which improves performance, safety, and cost over conventional hypergolic systems due to higher performance, use of nontoxic propellants, potential for integration with life support and power subsystems, and compatibility with in-situ produced propellants.

Determining solid-fluid interface temperature distribution during phase change of cryogenic propellants using transient thermal modeling

Science.gov (United States)

Bellur, K.; Médici, E. F.; Hermanson, J. C.; Choi, C. K.; Allen, J. S.

2018-04-01

Control of boil-off of cryogenic propellants is a continuing technical challenge for long duration space missions. Predicting phase change rates of cryogenic liquids requires an accurate estimation of solid-fluid interface temperature distributions in regions where a contact line or a thin liquid film exists. This paper described a methodology to predict inner wall temperature gradients with and without evaporation using discrete temperature measurements on the outer wall of a container. Phase change experiments with liquid hydrogen and methane in cylindrical test cells of various materials and sizes were conducted at the Neutron Imaging Facility at the National Institute of Standards and Technology. Two types of tests were conducted. The first type of testing involved thermal cycling of an evacuated cell (dry) and the second involved controlled phase change with cryogenic liquids (wet). During both types of tests, temperatures were measured using Si-diode sensors mounted on the exterior surface of the test cells. Heat is transferred to the test cell by conduction through a helium exchange gas and through the cryostat sample holder. Thermal conduction through the sample holder is shown to be the dominant mode with the rate of heat transfer limited by six independent contact resistances. An iterative methodology is employed to determine contact resistances between the various components of the cryostat stick insert, test cell and lid using the dry test data. After the contact resistances are established, inner wall temperature distributions during wet tests are calculated.

Cryogenic foam insulation: Abstracted publications

Science.gov (United States)

Williamson, F. R.

1977-01-01

A group of documents were chosen and abstracted which contain information on the properties of foam materials and on the use of foams as thermal insulation at cryogenic temperatures. The properties include thermal properties, mechanical properties, and compatibility properties with oxygen and other cryogenic fluids. Uses of foams include applications as thermal insulation for spacecraft propellant tanks, and for liquefied natural gas storage tanks and pipelines.

Cryogenic refrigeration. (Latest citations from the Aerospace database). Published Search

International Nuclear Information System (INIS)

1993-09-01

The bibliography contains citations concerning cryogenic refrigeration or cryocooling. Design, development, testing, and evaluation of cryogenic cooling systems are discussed. Design applications in spacecraft, magnet cooling, superconductors, liquid fuel storage, radioastronomy, and medicine are presented. Material properties at cryogenic temperatures and cryogenic rocket propellants are considered in separate bibliographies. (Contains 250 citations and includes a subject term index and title list.)

LV-IMLI: Integrated MLI/Aeroshell for Cryogenic Launch Vehicles, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Cryogenic propellants have the highest energy density of any rocket fuel, and are used in most NASA and commercial launch vehicles to power their ascent. Cryogenic...

New Propellants and Cryofuels

Science.gov (United States)

Palasezski, Bryan; Sullivan, Neil S.; Hamida, Jaha; Kokshenev, V.

2006-01-01

The proposed research will investigate the stability and cryogenic properties of solid propellants that are critical to NASA s goal of realizing practical propellant designs for future spacecraft. We will determine the stability and thermal properties of a solid hydrogen-liquid helium stabilizer in a laboratory environment in order to design a practical propellant. In particular, we will explore methods of embedding atomic species and metallic nano-particulates in hydrogen matrices suspended in liquid helium. We will also measure the characteristic lifetimes and diffusion of atomic species in these candidate cryofuels. The most promising large-scale advance in rocket propulsion is the use of atomic propellants; most notably atomic hydrogen stabilized in cryogenic environments, and metallized-gelled liquid hydrogen (MGH) or densified gelled hydrogen (DGH). The new propellants offer very significant improvements over classic liquid oxygen/hydrogen fuels because of two factors: (1) the high energy-release, and (ii) the density increase per unit energy release. These two changes can lead to significant reduced mission costs and increased payload to orbit weight ratios. An achievable 5 to 10 percent improvement in specific impulse for the atomic propellants or MGH fuels can result in a doubling or tripling of system payloads. The high-energy atomic propellants must be stored in a stabilizing medium such as solid hydrogen to inhibit or delay their recombination into molecules. The goal of the proposed research is to determine the stability and thermal properties of the solid hydrogen-liquid helium stabilizer. Magnetic resonance techniques will be used to measure the thermal lifetimes and the diffusive motions of atomic species stored in solid hydrogen grains. The properties of metallic nano-particulates embedded in hydrogen matrices will also be studied and analyzed. Dynamic polarization techniques will be developed to enhance signal/noise ratios in order to be able to

Design, fabrication and test of a liquid hydrogen titanium honeycomb cryogenic test tank for use as a reusable launch vehicle main propellant tank

Science.gov (United States)

Stickler, Patrick B.; Keller, Peter C.

1998-01-01

Reusable Launch Vehicles (RLV's) utilizing LOX\\LH2 as the propellant require lightweight durable structural systems to meet mass fraction goals and to reduce overall systems operating costs. Titanium honeycomb sandwich with flexible blanket TPS on the windward surface is potentially the lightest-weight and most operable option. Light weight is achieved in part because the honeycomb sandwich tank provides insulation to its liquid hydrogen contents, with no need for separate cryogenic insulation, and in part because the high use temperature of titanium honeycomb reduces the required surface area of re-entry thermal protection systems. System operability is increased because TPS needs to be applied only to surfaces where temperatures exceed approximately 650 K. In order to demonstrate the viability of a titanium sandwich constructed propellant tank, a technology demonstration program was conducted including the design, fabrication and testing of a propellant tank-TPS system. The tank was tested in controlled as well as ambient environments representing ground hold conditions for a RLV main propellant tank. Data collected during each test run was used to validate predictions for air liquefaction, outside wall temperature, boil-off rates, frost buildup and its insulation effects, and the effects of placing a thermal protection system blanket on the external surface. Test results indicated that titanium honeycomb, when used as a RLV propellant tank material, has great promise as a light-weight structural system.

Physics Simulation Software for Autonomous Propellant Loading and Gas House Autonomous System Monitoring

Science.gov (United States)

Regalado Reyes, Bjorn Constant

2015-01-01

1. Kennedy Space Center (KSC) is developing a mobile launching system with autonomous propellant loading capabilities for liquid-fueled rockets. An autonomous system will be responsible for monitoring and controlling the storage, loading and transferring of cryogenic propellants. The Physics Simulation Software will reproduce the sensor data seen during the delivery of cryogenic fluids including valve positions, pressures, temperatures and flow rates. The simulator will provide insight into the functionality of the propellant systems and demonstrate the effects of potential faults. This will provide verification of the communications protocols and the autonomous system control. 2. The High Pressure Gas Facility (HPGF) stores and distributes hydrogen, nitrogen, helium and high pressure air. The hydrogen and nitrogen are stored in cryogenic liquid state. The cryogenic fluids pose several hazards to operators and the storage and transfer equipment. Constant monitoring of pressures, temperatures and flow rates are required in order to maintain the safety of personnel and equipment during the handling and storage of these commodities. The Gas House Autonomous System Monitoring software will be responsible for constantly observing and recording sensor data, identifying and predicting faults and relaying hazard and operational information to the operators.

Liquid Oxygen Propellant Densification Unit Ground Tested With a Large-Scale Flight-Weight Tank for the X-33 Reusable Launch Vehicle

Science.gov (United States)

Tomsik, Thomas M.

2002-01-01

Propellant densification has been identified as a critical technology in the development of single-stage-to-orbit reusable launch vehicles. Technology to create supercooled high-density liquid oxygen (LO2) and liquid hydrogen (LH2) is a key means to lowering launch vehicle costs. The densification of cryogenic propellants through subcooling allows 8 to 10 percent more propellant mass to be stored in a given unit volume, thereby improving the launch vehicle's overall performance. This allows for higher propellant mass fractions than would be possible with conventional normal boiling point cryogenic propellants, considering the normal boiling point of LO2 and LH2.

Evaluation of Aluminum Alloy 2050-T84 Microstructure and Mechanical Properties at Ambient and Cryogenic Temperatures

Science.gov (United States)

Hafley, Robert A.; Domack, Marcia S.; Hales, Stephen J.; Shenoy, Ravi N.

2011-01-01

Aluminum alloy 2050 is being considered for the fabrication of cryogenic propellant tanks to reduce the mass of future heavy-lift launch vehicles. The alloy is available in section thicknesses greater than that of the incumbent aluminum alloy, 2195, which will enable designs with greater structural efficiency. While ambient temperature design allowable properties are available for alloy 2050, cryogenic properties are not available. To determine its suitability for use in cryogenic propellant tanks, tensile, compression and fracture tests were conducted on 4 inch thick 2050-T84 plate at ambient temperature and at -320degF. Various metallurgical analyses were also performed in order to provide an understanding of the compositional homogeneity and microstructure of 2050.

Advances in LO2 Propellant Conditioning

Science.gov (United States)

Mehta, Gopal; Orth, Michael; Stone, William; Perry, Gretchen; Holt, Kimberly; Suter, John

1994-01-01

This paper describes the cryogenic testing and analysis that has recently been completed as part of a multi-year effort to develop a new, more robust and operable LO2 propellant conditioning system. Phase 1 of the program consisted of feasibility demonstrations ot four novel propellant conditioning concepts. A no-bleed, passive propellant conditioning option was shown for the first time to successfully provide desired propellant inlet conditions. The benefits of passive conditioning are reduced operations costs, decreased hardware costs, enhanced operability and increased reliability on future expendable launch vehicles In Phase 2 of the test program, effects of major design parameters were studied and design correlation for future vehicle design were developed. Simultaneously, analytical models were developed and validated. Over 100 tests were conducted with a full-scale feedline using LN2 as the test fluid. A circulation pump provided a range of pressure and flow conditions. The test results showed that the passive propellant conditioning system is insensitive to variations in many of the parameters. The test program provides the validation necessary to incorporate the passive conditioning system into the baseline of future vehicles. Modeling of these systems using computational fluid dynamics seems highly promising.

Nanostructured Material for Accurate and Fast Tracking of Cryogenic Temperatures, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — The use of cryogenic propellants in next-generation launch vehicles and rockets relies to a great extent on the availability of rugged, high accuracy (0.2%), fast...

A highly reliable cryogenic mixing pump with no mechanical moving parts

Science.gov (United States)

Chen, W.; Niblick, A. L.

2017-12-01

This paper presents the design and preliminary test results of a novel cryogenic mixing pump based on magnetocaloric effect. The mixing pump is developed to enable long-term cryogenic propellant storage in space by preventing thermal stratification of cryogens in storage tanks. The mixing pump uses an innovative thermodynamic process to generate fluid jets to promote fluid mixing, eliminating the need for mechanical pumps. Its innovative mechanism uses a solid magnetocaloric material to alternately vaporize and condense the cryogen in the pumping chamber, and thus control the volume of the fluid inside the pumping chamber to produce pumping action. The pump is capable of self-priming and can generate a high-pressure rise. This paper discusses operating mechanism and design consideration of the pump, introduces the configuration of a brassboard cryogenic pump, and presents the preliminary test results of the pump with liquid nitrogen.

Characterizing Dissolved Gases in Cryogenic Liquid Fuels

Science.gov (United States)

Richardson, Ian A.

Pressure-Density-Temperature-Composition (PrhoT-x) measurements of cryogenic fuel mixtures are a historical challenge due to the difficulties of maintaining cryogenic temperatures and precision isolation of a mixture sample. For decades NASA has used helium to pressurize liquid hydrogen propellant tanks to maintain tank pressure and reduce boil off. This process causes helium gas to dissolve into liquid hydrogen creating a cryogenic mixture with thermodynamic properties that vary from pure liquid hydrogen. This can lead to inefficiencies in fuel storage and instabilities in fluid flow. As NASA plans for longer missions to Mars and beyond, small inefficiencies such as dissolved helium in liquid propellant become significant. Traditional NASA models are unable to account for dissolved helium due to a lack of fundamental property measurements necessary for the development of a mixture Equation Of State (EOS). The first PrhoT-x measurements of helium-hydrogen mixtures using a retrofitted single-sinker densimeter, magnetic suspension microbalance, and calibrated gas chromatograph are presented in this research. These measurements were used to develop the first multi-phase EOS for helium-hydrogen mixtures which was implemented into NASA's Generalized Fluid System Simulation Program (GFSSP) to determine the significance of mixture non-idealities. It was revealed that having dissolved helium in the propellant does not have a significant effect on the tank pressurization rate but does affect the rate at which the propellant temperature rises. PrhoT-x measurements are conducted on methane-ethane mixtures with dissolved nitrogen gas to simulate the conditions of the hydrocarbon seas of Saturn's moon Titan. Titan is the only known celestial body in the solar system besides Earth with stable liquid seas accessible on the surface. The PrhoT-x measurements are used to develop solubility models to aid in the design of the Titan Submarine. NASA is currently designing the submarine

Cryogenic Moisture Uptake in Foam Insulation for Space Launch Vehicles

Science.gov (United States)

Fesmire, James E.; ScholtensCoffman, Brekke E.; Sass, Jared P.; Williams, Martha K.; Smith, Trent M.; Meneghelli, Barrry J.

2008-01-01

Rigid polyurethane foams and rigid polyisocyanurate foams (spray-on foam insulation), like those flown on Shuttle, Delta IV, and will be flown on Ares-I and Ares-V, can gain an extraordinary amount of water when under cryogenic conditions for several hours. These foams, when exposed for eight hours to launch pad environments on one side and cryogenic temperature on the other, increase their weight from 35 to 80 percent depending on the duration of weathering or aging. This effect translates into several thousand pounds of additional weight for space vehicles at lift-off. A new cryogenic moisture uptake apparatus was designed to determine the amount of water/ice taken into the specimen under actual-use propellant loading conditions. This experimental study included the measurement of the amount of moisture uptake within different foam materials. Results of testing using both aged specimens and weathered specimens are presented. To better understand cryogenic foam insulation performance, cryogenic moisture testing is shown to be essential. The implications for future launch vehicle thermal protection system design and flight performance are discussed.

Gas Gun Model and Comparison to Experimental Performance of Pipe Guns Operating with Light Propellant Gases and Large Cryogenic Pellets

Energy Technology Data Exchange (ETDEWEB)

Reed, J. R. [University of Tennessee, Knoxville (UTK); Carmichael, J. R. [Fermi National Accelerator Laboratory (FNAL); Gebhart, T. E. [University of Florida, Gainesville; Combs, Stephen Kirk [ORNL; Baylor, Larry R. [ORNL; Rasmussen, David A. [ORNL; Meitner, Steven J. [ORNL; Lyttle, Mark S. [ORNL

2017-10-01

Injection of multiple large (~10 to 30 mm diameter) shattered pellets into ITER plasmas is presently part of the scheme planned to mitigate the deleterious effects of disruptions on the vessel components. To help in the design and optimize performance of the pellet injectors for this application, a model referred to as “the gas gun simulator” has been developed and benchmarked against experimental data. The computer code simulator is a Java program that models the gas-dynamics characteristics of a single-stage gas gun. Following a stepwise approach, the code utilizes a variety of input parameters to incrementally simulate and analyze the dynamics of the gun as the projectile is launched down the barrel. Using input data, the model can calculate gun performance based on physical characteristics, such as propellant-gas and fast-valve properties, barrel geometry, and pellet mass. Although the model is fundamentally generic, the present version is configured to accommodate cryogenic pellets composed of H2, D2, Ne, Ar, and mixtures of them and light propellant gases (H2, D2, and He). The pellets are solidified in situ in pipe guns that consist of stainless steel tubes and fast-acting valves that provide the propellant gas for pellet acceleration (to speeds ~200 to 700 m/s). The pellet speed is the key parameter in determining the response time of a shattered pellet system to a plasma disruption event. The calculated speeds from the code simulations of experiments were typically in excellent agreement with the measured values. With the gas gun simulator validated for many test shots and over a wide range of physical and operating parameters, it is a valuable tool for optimization of the injector design, including the fast valve design (orifice size and volume) for any operating pressure (~40 bar expected for the ITER application) and barrel length for any pellet size (mass, diameter, and length). Key design parameters and proposed values for the pellet injectors for

Low-Cost Propellant Launch to Earth Orbit from a Tethered Balloon

Science.gov (United States)

Wilcox, Brian H.

2006-01-01

Propellant will be more than 85% of the mass that needs to be lofted into Low Earth Orbit (LEO) in the planned program of Exploration of the Moon, Mars, and beyond. This paper describes a possible means for launching thousands of tons of propellant per year into LEO at a cost 15 to 30 times less than the current launch cost per kilogram. The basic idea is to mass-produce very simple, small and relatively low-performance rockets at a cost per kilogram comparable to automobiles, instead of the 25X greater cost that is customary for current launch vehicles that are produced in small quantities and which are manufactured with performance near the limits of what is possible. These small, simple rockets can reach orbit because they are launched above 95% of the atmosphere, where the drag losses even on a small rocket are acceptable, and because they can be launched nearly horizontally with very simple guidance based primarily on spin-stabilization. Launching above most of the atmosphere is accomplished by winching the rocket up a tether to a balloon. A fuel depot in equatorial orbit passes over the launch site on every orbit (approximately every 90 minutes). One or more rockets can be launched each time the fuel depot passes overhead, so the launch rate can be any multiple of 6000 small rockets per year, a number that is sufficient to reap the benefits of mass production.

Temperature Stratification in a Cryogenic Fuel Tank

Science.gov (United States)

Daigle, Matthew John; Smelyanskiy, Vadim; Boschee, Jacob; Foygel, Michael Gregory

2013-01-01

A reduced dynamical model describing temperature stratification effects driven by natural convection in a liquid hydrogen cryogenic fuel tank has been developed. It accounts for cryogenic propellant loading, storage, and unloading in the conditions of normal, increased, and micro- gravity. The model involves multiple horizontal control volumes in both liquid and ullage spaces. Temperature and velocity boundary layers at the tank walls are taken into account by using correlation relations. Heat exchange involving the tank wall is considered by means of the lumped-parameter method. By employing basic conservation laws, the model takes into consideration the major multi-phase mass and energy exchange processes involved, such as condensation-evaporation of the hydrogen, as well as flows of hydrogen liquid and vapor in the presence of pressurizing helium gas. The model involves a liquid hydrogen feed line and a tank ullage vent valve for pressure control. The temperature stratification effects are investigated, including in the presence of vent valve oscillations. A simulation of temperature stratification effects in a generic cryogenic tank has been implemented in Matlab and results are presented for various tank conditions.

An Improved Model of Cryogenic Propellant Stratification in a Rotating, Reduced Gravity Environment

Science.gov (United States)

Oliveira, Justin; Kirk, Daniel R.; Schallhorn, Paul A.; Piquero, Jorge L.; Campbell, Mike; Chase, Sukhdeep

2007-01-01

This paper builds on a series of analytical literature models used to predict thermal stratification within rocket propellant tanks. The primary contribution to the literature is to add the effect of tank rotation and to demonstrate the influence of rotation on stratification times and temperatures. This work also looks levels of thermal stratification for generic propellant tanks (cylindrical shapes) over a parametric range of upper-stage coast times, heating levels, rotation rates, and gravity levels.

A Cis-Lunar Propellant Infrastructure for Flexible Path Exploration and Space Commerce

Science.gov (United States)

Oeftering, Richard C.

2012-01-01

This paper describes a space infrastructure concept that exploits lunar water for propellant production and delivers it to users in cis-lunar space. The goal is to provide responsive economical space transportation to destinations beyond low Earth orbit (LEO) and enable in-space commerce. This is a game changing concept that could fundamentally affect future space operations, provide greater access to space beyond LEO, and broaden participation in space exploration. The challenge is to minimize infrastructure development cost while achieving a low operational cost. This study discusses the evolutionary development of the infrastructure from a very modest robotic operation to one that is capable of supporting human operations. The cis-lunar infrastructure involves a mix of technologies including cryogenic propellant production, reusable lunar landers, propellant tankers, orbital transfer vehicles, aerobraking technologies, and electric propulsion. This cislunar propellant infrastructure replaces Earth-launched propellants for missions beyond LEO. It enables users to reach destinations with smaller launchers or effectively multiplies the user s existing payload capacity. Users can exploit the expanded capacity to launch logistics material that can then be traded with the infrastructure for propellants. This mutually beneficial trade between the cis-lunar infrastructure and propellant users forms the basis of in-space commerce.

Weight savings in aerospace vehicles through propellant scavenging

Science.gov (United States)

Schneider, Steven J.; Reed, Brian D.

1988-01-01

Vehicle payload benefits of scavenging hydrogen and oxygen propellants are addressed. The approach used is to select a vehicle and a mission and then select a scavenging system for detailed weight analysis. The Shuttle 2 vehicle on a Space Station rendezvous mission was chosen for study. The propellant scavenging system scavenges liquid hydrogen and liquid oxygen from the launch propulsion tankage during orbital maneuvers and stores them in well insulated liquid accumulators for use in a cryogenic auxiliary propulsion system. The fraction of auxiliary propulsion propellant which may be scavenged for propulsive purposes is estimated to be 45.1 percent. The auxiliary propulsion subsystem dry mass, including the proposed scavenging system, an additional 20 percent for secondary structure, an additional 5 percent for electrical service, a 10 percent weight growth margin, and 15.4 percent propellant reserves and residuals is estimated to be 6331 kg. This study shows that the fraction of the on-orbit vehicle mass required by the auxiliary propulsion system of this Shuttle 2 vehicle using this technology is estimated to be 12.0 percent compared to 19.9 percent for a vehicle with an earth-storable bipropellant system. This results in a vehicle with the capability of delivering an additional 7820 kg to the Space Station.

Weight savings in aerospace vehicles through propellant scavenging

Science.gov (United States)

Schneider, Steven J.; Reed, Brian D.

1988-05-01

Vehicle payload benefits of scavenging hydrogen and oxygen propellants are addressed. The approach used is to select a vehicle and a mission and then select a scavenging system for detailed weight analysis. The Shuttle 2 vehicle on a Space Station rendezvous mission was chosen for study. The propellant scavenging system scavenges liquid hydrogen and liquid oxygen from the launch propulsion tankage during orbital maneuvers and stores them in well insulated liquid accumulators for use in a cryogenic auxiliary propulsion system. The fraction of auxiliary propulsion propellant which may be scavenged for propulsive purposes is estimated to be 45.1 percent. The auxiliary propulsion subsystem dry mass, including the proposed scavenging system, an additional 20 percent for secondary structure, an additional 5 percent for electrical service, a 10 percent weight growth margin, and 15.4 percent propellant reserves and residuals is estimated to be 6331 kg. This study shows that the fraction of the on-orbit vehicle mass required by the auxiliary propulsion system of this Shuttle 2 vehicle using this technology is estimated to be 12.0 percent compared to 19.9 percent for a vehicle with an earth-storable bipropellant system. This results in a vehicle with the capability of delivering an additional 7820 kg to the Space Station.

Liquid Acquisition Device Hydrogen Outflow Testing on the Cryogenic Propellant Storage and Transfer Engineering Design Unit

Science.gov (United States)

Zimmerli, Greg; Statham, Geoff; Garces, Rachel; Cartagena, Will

2015-01-01

As part of the NASA Cryogenic Propellant Storage and Transfer (CPST) Engineering Design Unit (EDU) testing with liquid hydrogen, screen-channel liquid acquisition devices (LADs) were tested during liquid hydrogen outflow from the EDU tank. A stainless steel screen mesh (325x2300 Dutch T will weave) was welded to a rectangular cross-section channel to form the basic LAD channel. Three LAD channels were tested, each having unique variations in the basic design. The LADs fed a common outflow sump at the aft end of the 151 cu. ft. volume aluminum tank, and included a curved section along the aft end and a straight section along the barrel section of the tank. Wet-dry sensors were mounted inside the LAD channels to detect when vapor was ingested into the LADs during outflow. The use of warm helium pressurant during liquid hydrogen outflow, supplied through a diffuser at the top of the tank, always led to early breakdown of the liquid column. When the tank was pressurized through an aft diffuser, resulting in cold helium in the ullage, LAD column hold-times as long as 60 minutes were achieved, which was the longest duration tested. The highest liquid column height at breakdown was 58 cm, which is 23 less than the isothermal bubble-point model value of 75 cm. This paper discusses details of the design, construction, operation and analysis of LAD test data from the CPST EDU liquid hydrogen test.

Design and development of graphite/epoxy feed line for use of cryogenic propulsion systems

International Nuclear Information System (INIS)

Kremer, J.S.; Kreiner, J.H.; Mosallam, A.S.

1998-01-01

The development of lightweight composite cryogenic ines is a critical technology for single-stage-to-orbit launch vehicles such as the Reusable Launch Vehicle (RLV). To achieve weight goals, a significant effort will be required to develop feed line designs that can reliably replace today's stainless steel configurations. A number of technical problems exist, including the large coefficient of thermal expansion (CTE) differential between the composite and interfacing metallic materials and the ability to seal against composite materials in a cryogenic environment. This paper reports the results of a development efforts undertaken to design, build, and test a graphite/epoxy propellant feed line to carry liquid hydrogen (-423 degree F). The design incorporates a reusable cryogenic insulation system and a secondarily bonded/co-cured splice joint

Methane Lunar Surface Thermal Control Test

Science.gov (United States)

Plachta, David W.; Sutherlin, Steven G.; Johnson, Wesley L.; Feller, Jeffrey R.; Jurns, John M.

2012-01-01

NASA is considering propulsion system concepts for future missions including human return to the lunar surface. Studies have identified cryogenic methane (LCH4) and oxygen (LO2) as a desirable propellant combination for the lunar surface ascent propulsion system, and they point to a surface stay requirement of 180 days. To meet this requirement, a test article was prepared with state-of-the-art insulation and tested in simulated lunar mission environments at NASA GRC. The primary goals were to validate design and models of the key thermal control technologies to store unvented methane for long durations, with a low-density high-performing Multi-layer Insulation (MLI) system to protect the propellant tanks from the environmental heat of low Earth orbit (LEO), Earth to Moon transit, lunar surface, and with the LCH4 initially densified. The data and accompanying analysis shows this storage design would have fallen well short of the unvented 180 day storage requirement, due to the MLI density being much higher than intended, its substructure collapse, and blanket separation during depressurization. Despite the performance issue, insight into analytical models and MLI construction was gained. Such modeling is important for the effective design of flight vehicle concepts, such as in-space cryogenic depots or in-space cryogenic propulsion stages.

Propellant Slosh Force and Mass Measurement

Directory of Open Access Journals (Sweden)

Andrew Hunt

2018-01-01

Full Text Available We have used electrical capacitance tomography (ECT to instrument a demonstration tank containing kerosene and have successfully demonstrated that ECT can, in real time, (i measure propellant mass to better than 1% of total in a range of gravity fields, (ii image propellant distribution, and (iii accurately track propellant centre of mass (CoM. We have shown that the ability to track CoM enables the determination of slosh forces, and we argue that this will result in disruptive changes in a propellant tank design and use in a spacecraft. Ground testing together with real-time slosh force data will allow an improved tank design to minimize and mitigate slosh forces, while at the same time keeping the tank mass to a minimum. Fully instrumented Smart Tanks will be able to provide force vector inputs to a spacecraft inertial navigation system; this in turn will (i eliminate or reduce navigational errors, (ii reduce wait time for uncertain slosh settling, since actual slosh forces will be known, and (iii simplify slosh control hardware, hence reducing overall mass. ECT may be well suited to space borne liquid measurement applications. Measurements are independent of and unaffected by orientation or levels of g. The electronics and sensor arrays can be low in mass, and critically, the technique does not dissipate heat into the propellant, which makes it intrinsically safe and suitable for cryogenic liquids. Because of the limitations of operating in earth-bound gravity, it has not been possible to check the exact numerical accuracy of the slosh force acting on the vessel. We are therefore in the process of undertaking a further project to (i build a prototype integrated “Smart Tank for Space”, (ii undertake slosh tests in zero or microgravity, (iii develop the system for commercial ground testing, and (iv qualify ECT for use in space.

PHM Enabled Autonomous Propellant Loading Operations

Science.gov (United States)

Walker, Mark; Figueroa, Fernando

2017-01-01

The utility of Prognostics and Health Management (PHM) software capability applied to Autonomous Operations (AO) remains an active research area within aerospace applications. The ability to gain insight into which assets and subsystems are functioning properly, along with the derivation of confident predictions concerning future ability, reliability, and availability, are important enablers for making sound mission planning decisions. When coupled with software that fully supports mission planning and execution, an integrated solution can be developed that leverages state assessment and estimation for the purposes of delivering autonomous operations. The authors have been applying this integrated, model-based approach to the autonomous loading of cryogenic spacecraft propellants at Kennedy Space Center.

Examination of adipose depot-specific PPAR moieties

Energy Technology Data Exchange (ETDEWEB)

Dodson, M.V., E-mail: dodson@wsu.edu [Department of Animal Sciences, Washington State University, Pullman, WA 99164 (United States); Vierck, J.L. [Department of Animal Sciences, Washington State University, Pullman, WA 99164 (United States); Hausman, G.J. [USDA-ARS, Richard B. Russell Agricultural Research Station, Athens, GA 30604 (United States); Guan, L.L. [Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, T6G 2P5 Canada (Canada); Fernyhough, M.E. [The Hartz Mountain Corporation, Secaucus, NJ 07094 (United States); Poulos, S.P. [The Coca-Cola Company, Research and Technology, Atlanta, GA 30313 (United States); Mir, P.S. [Agriculture and Agri-Food Canada Research Centre, Lethbridge, CA T1J 4B1 (United States); Jiang, Z. [Department of Animal Sciences, Washington State University, Pullman, WA 99164 (United States)

2010-04-02

Molecular mechanisms of peroxisome proliferator activated receptors (PPARs) are being defined rapidly, as illustrated by the volume of papers published. Much of the research is directed towards a clinical end-point/application; however, the non-homogeneous nature of adipose depots in laboratory animals is spurring similar research in domestic meat animals (such as beef cattle). Moreover, the size of adipose depots in meat animals remains an attractive feature for using them to obtain cells for PPAR research. Examination of meat-animal depot-specific PPAR moieties may provide novel information about adipocyte regulation that might be extrapolated to all animals.

Examination of adipose depot-specific PPAR moieties

International Nuclear Information System (INIS)

Dodson, M.V.; Vierck, J.L.; Hausman, G.J.; Guan, L.L.; Fernyhough, M.E.; Poulos, S.P.; Mir, P.S.; Jiang, Z.

2010-01-01

Molecular mechanisms of peroxisome proliferator activated receptors (PPARs) are being defined rapidly, as illustrated by the volume of papers published. Much of the research is directed towards a clinical end-point/application; however, the non-homogeneous nature of adipose depots in laboratory animals is spurring similar research in domestic meat animals (such as beef cattle). Moreover, the size of adipose depots in meat animals remains an attractive feature for using them to obtain cells for PPAR research. Examination of meat-animal depot-specific PPAR moieties may provide novel information about adipocyte regulation that might be extrapolated to all animals.

DEPOT database: Reference manual and user's guide

International Nuclear Information System (INIS)

Clancey, P.; Logg, C.

1991-03-01

DEPOT has been developed to provide tracking for the Stanford Linear Collider (SLC) control system equipment. For each piece of equipment entered into the database, complete location, service, maintenance, modification, certification, and radiation exposure histories can be maintained. To facilitate data entry accuracy, efficiency, and consistency, barcoding technology has been used extensively. DEPOT has been an important tool in improving the reliability of the microsystems controlling SLC. This document describes the components of the DEPOT database, the elements in the database records, and the use of the supporting programs for entering data, searching the database, and producing reports from the information

Modeling and Solving the Multi-depot Vehicle Routing Problem with Time Window by Considering the Flexible end Depot in Each Route

Directory of Open Access Journals (Sweden)

Mohammad Mirabi

2016-11-01

Full Text Available This paper considers the multi-depot vehicle routing problem with time window in which each vehicle starts from a depot and there is no need to return to its primary depot after serving customers. The mathematical model which is developed by new approach aims to minimizing the transportation cost including the travelled distance, the latest and the earliest arrival time penalties. Furthermore, in order to reduce the problem searching space, a novel GA clustering method is developed. Finally, Experiments are run on number problems of varying depots and time window, and customer sizes. The method is compared to two other clustering techniques, fuzzy C means (FCM and K-means algorithm. Experimental results show the robustness and effectiveness of the proposed algorithm.

NASA Cryogenic Propellant Systems Technology Development and Potential Opportunities for Discussion

Science.gov (United States)

Meyer, Michael L.

2015-01-01

Members of the eCryo Team are traveling to France to meet with CNES (Centre National d'Etudes Spatiales) on the benchmarking of CFM (Cryogenic Fluids Management) analytical models the week of January 26th, 2015. Mike Meyer is representing the Agency and eCryo Project and will conduct a conversation to explore future work. This slide package (28 charts and 3 movies) requires approval via a 1676. ISS data in this chart set has been copied from public websites.

Perancangan Propeler Self-Propelled Barge

Directory of Open Access Journals (Sweden)

Billy Teguh kurniawan

2013-03-01

Full Text Available Makalah ini menyampaikan suatu penelitian tentang perancangan propeler yang optimal beserta pemilihan daya mesin yang efisien pada self-propelled barge dengan memperhitungkan besarnya nilai tahanan dari barge tersebut. Dengan penambahan sistem propulsi, diharapkan barge dapat beroperasi dengan lebih efisien dibandingkan saat barge beroperasi menggunakan sistem towing atau ditarik tug boat. Perhitungan tahanan barge dilakukan menggunakan metode Holtrop dan Guldhammer-Harvald sehingga dapat diperhi-tungkan geometri dan jenis propeler yang optimal beserta daya mesin yang efisien untuk barge. Propeler yang dianalisis adalah propeler tipe B-Troost Series, sedangkan variasi yang dilakukan untuk perencanaan propeler pada kajian ini adalah variasi putaran propeler pada rentang antara 310-800 rpm, serta variasi jumlah daun pada rentang tiga, empat, lima, dan enam. Besarnya nilai tahanan self-propelled barge untuk metode Holtrop adalah 105.91 kilonewton, sedangkan hasil per-hitungan dari metode Guldhammer-Harvald didapatkan nilai sebesar 109.14 kilonewton. Tipe propeler yang dipilih setelah dilakukan uji kavitasi adalah tipe Troost Series B4-40, dengan diameter sebesar 2.1 m, efisiensi sebesar 0.421, pitch ratio se-besar 0.591, dengan putaran propeler 400 rpm. Daya mesin yg dibutuhkan barge pada kondisi maksimum (BHPMCR sebesar 1669.5 HP. Dengan mempertimbangkan daya tersebut, maka dipilih mesin jenis Caterpillar tipe Marine 3516B yang mem-punyai daya maksimum sebesar 1285 kilowatt atau 1722.5 horsepower dengan putaran mesin sebesar 1200 rpm

Ligand Depot: a data warehouse for ligands bound to macromolecules.

Science.gov (United States)

Feng, Zukang; Chen, Li; Maddula, Himabindu; Akcan, Ozgur; Oughtred, Rose; Berman, Helen M; Westbrook, John

2004-09-01

Ligand Depot is an integrated data resource for finding information about small molecules bound to proteins and nucleic acids. The initial release (version 1.0, November, 2003) focuses on providing chemical and structural information for small molecules found as part of the structures deposited in the Protein Data Bank. Ligand Depot accepts keyword-based queries and also provides a graphical interface for performing chemical substructure searches. A wide variety of web resources that contain information on small molecules may also be accessed through Ligand Depot. Ligand Depot is available at http://ligand-depot.rutgers.edu/. Version 1.0 supports multiple operating systems including Windows, Unix, Linux and the Macintosh operating system. The current drawing tool works in Internet Explorer, Netscape and Mozilla on Windows, Unix and Linux.

The performance of a piezoelectric-sensor-based SHM system under a combined cryogenic temperature and vibration environment

International Nuclear Information System (INIS)

Qing, Xinlin P; Beard, Shawn J; Kumar, Amrita; Sullivan, Kevin; Aguilar, Robert; Merchant, Munir; Taniguchi, Mike

2008-01-01

A series of tests have been conducted to determine the survivability and functionality of a piezoelectric-sensor-based active structural health monitoring (SHM) SMART Tape system under the operating conditions of typical liquid rocket engines such as cryogenic temperature and vibration loads. The performance of different piezoelectric sensors and a low temperature adhesive under cryogenic temperature was first investigated. The active SHM system for liquid rocket engines was exposed to flight vibration and shock environments on a simulated large booster LOX-H 2 engine propellant duct conditioned to cryogenic temperatures to evaluate the physical robustness of the built-in sensor network as well as operational survivability and functionality. Test results demonstrated that the developed SMART Tape system can withstand operational levels of vibration and shock energy on a representative rocket engine duct assembly, and is functional under the combined cryogenic temperature and vibration environment

Mascotte, a research test facility for high pressure combustion of cryogenic propellants; Mascotte, un banc d'essai de recherche pour la combustion a haute pression d'ergols cryogeniques

Energy Technology Data Exchange (ETDEWEB)

Vingert, L.; Habiballah, M.; Traineau, J.C. [Office National d' Etudes et de Recherches Aerospatiales (ONERA), 92 - Chatillon (France)

2000-07-01

Detailed experimental studies of cryogenic propellant combustion are needed to improve design and optimization of high performance liquid rocket engines. A research test facility called Mascotte has been built up by ONERA to study elementary processes that are involved in the combustion of liquid oxygen and gaseous hydrogen. Mascotte is aimed at feeding a single element combustor with actual propellants, and the third version in operation since mid 1998 allows to reach supercritical pressures in the combustor. A specific high pressure combustor was developed for this purpose. Research teams from different laboratories belonging to CNRS and ONERA, regrouped in a common research program managed by CNES and SNECMA division SEP, may run experiments on Mascotte, with several objectives: - improve the knowledge and the modeling of physical phenomena; - provide experimental results for computer code validation; - improve and assess diagnostic techniques (especially optical diagnostics). Following diagnostics for instance, were used on Mascotte from 1994 to 1999: - OH imaging (spontaneous emission and laser induced fluorescence ); - CARS temperature measurements (using the H{sub 2} and simultaneously the H{sub 2}O molecules); - High speed cinematography (with a copper vapor laser synchronized to a high speed camera); - O{sub 2} vapor imaging (laser induced fluorescence); - Particle sizing (by means of a Phase Doppler Particle Analyzer). (authors)

Modified-Collins cryocooler for zero-boiloff storage of cryogenic fuels in space

Science.gov (United States)

Hannon, Charles L.; Krass, Brady; Hogan, Jake; Brisson, John

2012-06-01

Future lunar and planetary explorations will require the storage of cryogenic propellants, particularly liquid oxygen (LOX) and liquid hydrogen (LH2), in low earth orbit (LEO) for periods of time ranging from days to months, and possibly longer. Without careful thermal management, significant quantities of stored liquid cryogens can be lost due to boil-off. Boil-off can be minimized by a variety of passive means including insulation, sun shades and passive radiational cooling. However, it has been shown that active cooling using space cryocoolers has the potential to result in Zero Boil-Off (ZBO) and the launch-mass savings using active cooling exceeds that of passive cooling of LOX for mission durations in LEO of less than 1 week, and for LH2 after about 2 months in LEO. Large-scale DC-flow cryogenic refrigeration systems operate at a fraction of the specific power levels required by small-scale AC-flow cryocoolers. The efficiency advantage of DC-flow cryogenic cycles motivates the current development of a cryocooler based on a modification of the Collins Cycle. The modified Collins cycle design employs piston type expanders that support high operating pressure ratios, electromagnetic valves that enable "floating pistons", and recuperative heat transfer. This paper will describe the design of a prototype Modified-Collins cryocooler for ZBO storage of cryogenic fuels in space.

Makahiki+WattDepot

DEFF Research Database (Denmark)

Johnson, Philip M.; Xu, Yongwen; Brewer, Robert S.

2013-01-01

to consumers. Since 2009, we have been designing, implementing, and evaluating an open source software "stack" to facilitate this research. This software stack consists of two custom systems called WattDepot and Makahiki, along with the open source components they rely upon (Java, Restlet, Postgres, Python...

A water blown urethane insulation for use in cryogenic environments

Science.gov (United States)

Blevins, Elana; Sharpe, Jon

1995-01-01

Thermal Protection Systems (TPS) of NASA's Space Shuttle External Tank include polyurethane and polyisocyanurate modified polyurethane foam insulations. These insulations, currently foamed with CFC 11 blowing agent, serve to maintain cryogenic propellant quality, maintain the external tank structural temperature limits, and minimize the formation of ice and frost that could potentially damage the ceramic insulation on the space shuttle orbiter. During flight the external tank insulations are exposed to mechanical, thermal and acoustical stresses. TPS must pass cryogenic flexure and substrate adhesion tests at -253 C, aerothermal and radiant heating tests at fluxes up to approximately 14 kilowatts per square meter, and thermal conductivity tests at cryogenic and elevated temperatures. Due to environmental concerns, the polyurethane insulation industry and the External Tank Project are tasked with replacing CFC 11. The flight qualification of foam insulations employing HCFC 141b as a foaming agent is currently in progress; HCFC 141b blown insulations are scheduled for production implementation in 1995. Realizing that the second generation HCFC blowing agents are an interim solution, the evaluation of third generation blowing agents with zero ozone depletion potential is underway. NASA's TPS Materials Research Laboratory is evaluating third generation blowing agents in cryogenic insulations for the External Tank; one option being investigated is the use of water as a foaming agent. A dimensionally stable insulation with low friability, good adhesion to cryogenic substrates, and acceptable thermal conductivity has been developed with low viscosity materials that are easily processed in molding applications. The development criteria, statistical experimental approach, and resulting foam properties will be presented.

Pengembangan Merek dan Pengkajian Strategi Pemasaran di Depot Rasa Suka Kediri

OpenAIRE

Raharjo, Rini; Surjani, Rosita Meitha; Rinawiyanti, Esti Dwi

2013-01-01

Depot Rasa Suka is a culinary business that provides a variety of Indonesian dishes. However people still do not know and yet loyal to Depot Rasa Suka due to the unavailability of parking space, quite a long serving time, hot room, less attractive promotion and room design. Therefore Depot Rasa Suka need to devise strategies to develop brands through brand equity analysis and improvement of brand elements as well as designing a marketing strategies. The goal of this research is to make Depot ...

Low-Cost High-Performance Cryocoolers for In-Situ Propellant Production

Science.gov (United States)

Martin, J. L.; Corey, J. A.; Peters, T. A.

1999-01-01

A key feature of many In-Situ Resource Utilization (ISRU) schemes is the production of rocket fuel and oxidizer from the Martian atmosphere. Many of the fuels under consideration will require cryogenic cooling for efficient long-term storage. Although significant research has been focused on the techniques for producing the fuels from Martian resources, little effort has been expended on the development of cryocoolers to efficiently liquefy these fuels. This paper describes the design of a pulse tube liquefier optimized for liquefying oxygen produced by an In-Situ Propellant Production (ISPP) plant on Mars.

Depot Medroxyprogesterone Acetate (Depo-Provlera) as a Contrac ...

African Journals Online (AJOL)

Depot Medroxyprogesterone Acetate (Depo-Provlera) as a Contrac·eptive Preparation. Basil Bloch. Abstract. Experience with depot medroxyprogesterone acetate as a contraceptive preparation in 7 335 patients for a total of 38 714 months over a 3-year period is described. The discontinuation rate was 18.3% and the ...

Computer-aided acquisition and logistics support (CALS): Concept of Operations for Depot Maintenance

Energy Technology Data Exchange (ETDEWEB)

Bourgeois, N.C.; Greer, D.K.

1993-04-01

This CALS Concept of Operations for Depot Maintenance provides the foundation strategy and the near term tactical plan for CALS implementation in the depot maintenance environment. The user requirements enumerated and the overarching architecture outlined serve as the primary framework for implementation planning. The seamless integration of depot maintenance business processes and supporting information systems with the emerging global CALS environment will be critical to the efficient realization of depot user's information requirements, and as, such will be a fundamental theme in depot implementations.

Depot Maintenance: Executed Workload and Maintenance Operations at DOD Depots

Science.gov (United States)

2017-02-03

in turn enable testing of helicopter rotor blades. The Army has also made investments in logistics software at all of its depots. According to the...maintenance and repair of structural helicopter airframes and blades; advanced composite technologies; flight controls and control surfaces; and...level maintenance on a wide range of vehicles and other military assets, including helicopters , combat vehicles, ships, aircraft, engines, and software

Spatial Analysis of Depots for Advanced Biomass Processing

Energy Technology Data Exchange (ETDEWEB)

Hilliard, Michael R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Brandt, Craig C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Webb, Erin [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Sokhansanj, Shahabaddine [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Eaton, Laurence M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Martinez Gonzalez, Maria I. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2014-09-01

The objective of this work was to perform a spatial analysis of the total feedstock cost at the conversion reactor for biomass supplied by a conventional system and an advanced system with depots to densify biomass into pellets. From these cost estimates, the conditions (feedstock cost and availability) for which advanced processing depots make it possible to achieve cost and volume targets can be identified.

Thermal stratification in LH2 tank of cryogenic propulsion stage tested in ISRO facility

Science.gov (United States)

Xavier, M.; Raj, R. Edwin; Narayanan, V.

2017-02-01

Liquid oxygen and hydrogen are used as oxidizer and fuel respectively in cryogenic propulsion system. These liquids are stored in foam insulated tanks of cryogenic propulsion system and are pressurized using warm pressurant gas supplied for tank pressure maintenance during cryogenic engine operation. Heat leak to cryogenic propellant tank causes buoyancy driven liquid stratification resulting in formation of warm liquid stratum at liquid free surface. This warm stratum is further heated by the admission of warm pressurant gas for tank pressurization during engine operation. Since stratified layer temperature has direct bearing on the cavitation free operation of turbo pumps integrated in cryogenic engine, it is necessary to model the thermal stratification for predicting stratified layer temperature and mass of stratified liquid in tank at the end of engine operation. These inputs are required for estimating the minimum pressure to be maintained by tank pressurization system. This paper describes configuration of cryogenic stage for ground qualification test, stage hot test sequence, a thermal model and its results for a foam insulated LH2 tank subjected to heat leak and pressurization with hydrogen gas at 200 K during liquid outflow at 38 lps for engine operation. The above model considers buoyancy flow in free convection boundary layer caused by heat flux from tank wall and energy transfer from warm pressurant gas etc. to predict temperature of liquid stratum and mass of stratified liquid in tank at the end of engine operation in stage qualification tests carried out in ISRO facility.

Mars 2024/2026 Pathfinder Mission: Mars Architectures, Systems, and Technologies for Exploration and Resources Project

Science.gov (United States)

Zeitlin, Nancy; Mueller, Robert; Muscatello, Anthony

2015-01-01

Integrate In Situ Resource Utilization (ISRU) sub-systems and examine advanced capabilities and technologies to verify Mars 2024 Forward architecture precursor pathfinder options: Integrated spacecraft/surface infrastructure fluid architecture: propulsion, power, life support center dot Power system feed and propellant scavenging from propulsion system center dot High quality oxygen for life support and EVA Fluid/cryogenic zero-loss transfer and long-term storage center dot Rapid depot-to-rover/spacecraft center dot Slow ISRU plant-to-ascent vehicle Integration of ISRU consumable production center dot Oxygen only from Mars atmosphere carbon dioxide center dot Oxygen, fuel, water, from extraterrestrial soil/regolith Test bed to evaluate long duration life, operations, maintenance on hardware, sensors, and autonomy

Enhancement of polycyclic aromatic hydrocarbons in estuarine invertebrates by surface runoff at a decommissioned military fuel depot

Science.gov (United States)

Miles, A.K.; Roster, N.

1999-01-01

Accumulation of polycyclic aromatic hydrocarbons (PAHs) was determined in blue mussels (Mytilus spp.) and shore crabs (Hemigrapsus sp.) at a recently closed military fuel depot in central San Francisco Bay, California. In April 1996, during a period of above average precipitation, specimens were collected at the depot, near the depot, and at sites 10 and 20 km south of the depot. Four weeks after the rains ended, blue mussels were again collected at the depot, and at two additional sites in the central Bay region. In April, total PAHs in mussels from the depot were significantly higher only than that in mussels collected 20 km from the depot; however, seven specific, substituted PAHs were higher at the depot than at all other sites. In June, only two of the 38 PAHs common in mussels in April were detected at the depot; these concentrations were comparable to ambient concentrations in mussels at the Bay. It seemed that bioavailability of PAHs at the depot was enhanced by rainfall, probably due to the mobilization of PAHs via groundwater into the Bay. Concentrations in mussels from chronically contaminated sites were about five times higher than mussels collected from the depot. Low PAH concentrations were detected in shore crabs near the depot, and the highest levels were not associated with the depot. Observed PAH concentrations are discussed in relation to upper trophic organisms.

Wrapped Multilayer Insulation

Science.gov (United States)

Dye, Scott A.

2015-01-01

New NASA vehicles, such as Earth Departure Stage (EDS), Orion, landers, and orbiting fuel depots, need improved cryogenic propellant transfer and storage for long-duration missions. Current cryogen feed line multilayer insulation (MLI) performance is 10 times worse per area than tank MLI insulation. During each launch, cryogenic piping loses approximately 150,000 gallons (equivalent to $300,000) in boil-off during transfer, chill down, and ground hold. Quest Product Development Corp., teaming with Ball Aerospace, developed an innovative advanced insulation system, Wrapped MLI (wMLI), to provide improved thermal insulation for cryogenic feed lines. wMLI is high-performance multilayer insulation designed for cryogenic piping. It uses Quest's innovative discrete-spacer technology to control layer spacing/ density and reduce heat leak. The Phase I project successfully designed, built, and tested a wMLI prototype with a measured heat leak 3.6X lower than spiral-wrapped conventional MLI widely used for piping insulation. A wMLI prototype had a heat leak of 7.3 W/m2, or 27 percent of the heat leak of conventional MLI (26.7 W/m2). The Phase II project is further developing wMLI technology with custom, molded polymer spacers and advancing the product toward commercialization via a rigorous testing program, including developing advanced vacuuminsulated pipe for ground support equipment.

Cryogenics

International Nuclear Information System (INIS)

Fradkov, A.B.

1991-01-01

The application of cryogenics in various areas of science and technology is related in a popular way. Utilization of cryogenics in the following production processes is described: separation of air, gas mixtures; production of helium; separation of hydrogen isotopes; production of deuterium. Applications of cryogenics in refrigerating engineering, superconductivity and high-energy physics, controlled thermonuclear fusion, superconducting electric motors and electric energy storages are considered

Policies for Positioning Empty Containers in an Inland Multi-depot System

DEFF Research Database (Denmark)

Dang, Vinh Quang; Nielsen, Izabela Ewa; Yun, Won-Young

2011-01-01

-container management are as follows: a coordinated (s, S) inventory policy for overseas positioning, (ri, Ri) policy at each depot for inland positioning; and a simple leasing policy with zero lead-time. For inland positioning policy, four different methods are proposed to reposition empty containers between depots....... Customer demands and returning containers in depots and lead-time for positioning from overseas are considered as uncertain factors. The objective is to obtain the optimal policy in order to minimize the expected total cost including inventory holding, overseas positioning, inland positioning and leasing...

Cryogenics a textbook

CERN Document Server

Thipse, S S

2013-01-01

A Textbook covers lucidly various cryogenic applications including cryogenic engines and space and electronic applications. Importance of cryogenic engines in space propulsion, complete thermodynamic analysis of cryogenic systems with special emphasis on cryogenic cycles, Dewar vessels used to store cryogenic fluids and their applications in various industries have also been discussed in detail. Explanation of Superconductivity and its applications with a description of various Cryocoolers used in industry has also been provided with extensive details. Further technical information on cryogens has been specified alongwith the vacuum technology which has been sufficiently described with examples. Science of Cryonics has been elaborated and all aspects of technology related to functioning of cryogenic plants and their construction including valves, pipes has been incorporated in this book.

Design Technique for the High-Boiling Propellant Storage and Preparation Facility at the Cosmodrome «Vostochny»

Directory of Open Access Journals (Sweden)

O. E. Denisov

2014-01-01

Full Text Available The offered project of storage facility allows us to simplify and unitise the ground-based infrastructure objects. The storage facility implements a full preparatory cycle of the propellant components (PC in all parameters. Another problem the developers of complexes of groundbased equipment face now is bulk receipt of PC from manufacturer. The tanks of launch complexes cannot accept such volumes of propellant. It proves that there is a need to create a storage facility. The facility solves problems concerning the components receipt, temperature preparation, moisture content (drying, gas content, and supply to consumers. For preparation the perspective technologies with low power consumption are used.Receiving the propellant from the dispensing platform is carried out via filters of rough cleaning. Transfer from transport tankage goes using a pump. The received product passes through a gas separator to clean technological gas impurity.To prepare propellant temperature, a technology of cryogenic bubbling by boiling nitrogen is chosen. To improve efficiency of cryogenic bubbling it is advised to use the specialized capacities. Railway dimensions, admissible for the trainload goods across the railroads of Siberia and the Far East, define their sizes.As a drying technology and a gas content preparation the preliminary propellant filtration using vertical electro-separators is chosen to save a space. The chamber vertical electroseparators allow 2 — 3 times increase of dehydration capacity.The article presents calculations to prove that using the chosen cooling and drying technologies is efficient.Prepared PC can be supplied:• to transport-fueling containers (TFC with the subsequent transportation to the launch complexes either by the railway or by road;• to mobile fuelling tanks, which feed rocket-carrier tanks on arrival at the blast-off;• to transport capacities for transportation to the object outside the cosmodrome (spaceport;• directly

Network technology for depot modernization

Energy Technology Data Exchange (ETDEWEB)

Hostick, C.J.

1990-12-01

This report was prepared by the Pacific Northwest Laboratory to summarize existing and emerging information system technology and standards applicable to Depot System Command (DESCOM) modernization efforts. The intent of this summarization is to provide the Revitalization of Army Depots for the Year 2000 (READY 2000) team a clear understanding of the enabling information system technologies required to support effective modernization activities. Much of the information contained in this report was acquired during the last year in support of the US Army Armament, Munitions, and Chemical Command (AMCCOM) Facility Integrated Manufacturing Management System (FIMMS) project at PNL, which is targeting the modernization of plant-wide information systems at Army Ammunition Plants. The objective of information system modernization is to improve the effectiveness of an organization in performing its mission. Information system modernization strives to meet this objective by creating an environment where data is electronically captured near the source and readily available to all areas of the organization. Advanced networks, together with related information system technology, are the enabling mechanisms that make modern information system infrastructures possible. The intent of this paper is to present an overview of advanced information system network technology to support depot modernization planners in making technology management decisions. Existing and emerging Open System Interconnection (OSI) and Government Open System Interconnection Profile (GOSIP) standards are explained, as well as a brief assessment of existing products compliant with these standards. Finally, recommendations for achieving plant-wide integration using existing products are presented, and migration strategies for full OSI compliance are introduced. 5 refs., 16 figs. (JF)

The Effect of an Isogrid on Cryogenic Propellant Behavior and Thermal Stratification

Science.gov (United States)

Oliveira, Justin; Kirk, Daniel R.; Chintalapati, Sunil; Schallhorn, Paul A.; Piquero, Jorge L.; Campbell, Mike; Chase, Sukhdeep

2007-01-01

All models for thermal stratification available in the presentation are derived using smooth, flat plate laminar and turbulent boundary layer models. This study examines the effect of isogrid (roughness elements) on the surface of internal tank walls to mimic the effects of weight-saving isogrid, which is located on the inside of many rocket propellant tanks. Computational Fluid Dynamics (CFD) is used to study the momentum and thermal boundary layer thickness for free convection flows over a wall with generic roughness elements. This presentation makes no mention of actual isogrid sizes or of any specific tank geometry. The magnitude of thermal stratification is compared for smooth and isogrid-lined walls.

DEPOT: Database for electronics parts and other things

International Nuclear Information System (INIS)

Logg, C.A.; Clancey, P.W.; Crane, G.

1990-01-01

DEPOT has been developed to provide tracking for the Stanford Linear Collider (SLC) control system equipment. For each piece of equipment entered in the database, a complete service, maintenance, modification, certification, location history, and, optionally, a radiation exposure history, can be maintained. To facilitate data entry accuracy, efficiency, and consistency, barcoding technology has been used extensively. DEPOT has been an important tool in improving the reliability of the microsystems controlling SLC. It is now being adopted by other systems at SLAC. 6 refs., 6 figs

Cryogenics safety

International Nuclear Information System (INIS)

Reider, R.

1977-01-01

The safety hazards associated with handling cryogenic fluids are discussed in detail. These hazards include pressure buildup when a cryogenic fluid is heated and becomes a gas, potential damage to body tissues due to surface contact, toxic risk from breathing air altered by cryogenic fluids, dangers of air solidification, and hazards of combustible cryogens such as liquified oxygen, hydrogen, or natural gas or of combustible mixtures. Safe operating procedures and emergency planning are described

Development of self-forming doxorubicin-loaded polymeric depots as an injectable drug delivery system for liver cancer chemotherapy.

Science.gov (United States)

Nittayacharn, Pinunta; Nasongkla, Norased

2017-07-01

The objective of this work was to develop self-forming doxorubicin-loaded polymeric depots as an injectable drug delivery system for liver cancer chemotherapy and studied the release profiles of doxorubicin (Dox) from different depot formulations. Tri-block copolymers of poly(ε-caprolactone), poly(D,L-lactide) and poly(ethylene glycol) named PLECs were successfully used as a biodegradable material to encapsulate Dox as the injectable local drug delivery system. Depot formation and encapsulation efficiency of these depots were evaluated. Results show that depots could be formed and encapsulate Dox with high drug loading content. For the release study, drug loading content (10, 15 and 20% w/w) and polymer concentration (25, 30, and 35% w/v) were varied. It could be observed that the burst release occurred within 1-2 days and this burst release could be reduced by physical mixing of hydroxypropyl-beta-cyclodextrin (HP-β-CD) into the depot system. The degradation at the surface and cross-section of the depots were examined by Scanning Electron Microscope (SEM). In addition, cytotoxicity of Dox-loaded depots and blank depots were tested against human liver cancer cell lines (HepG2). Dox released from depots significantly exhibited potent cytotoxic effect against HepG2 cell line compared to that of blank depots. Results from this study reveals an important insight in the development of injectable drug delivery system for liver cancer chemotherapy. Schematic diagram of self-forming doxorubicin-loaded polymeric depots as an injectable drug delivery system and in vitro characterizations. (a) Dox-loaded PLEC depots could be formed with more than 90% of sustained-release Dox at 25% polymer concentration and 20% Dox-loading content. The burst release occurred within 1-2 days and could be reduced by physical mixing of hydroxypropyl-beta-cyclodextrin (HP-β-CD) into the depot system. (b) Dox released from depots significantly exhibited potent cytotoxic effect against human

Multiple depots vehicle routing based on the ant colony with the genetic algorithm

Directory of Open Access Journals (Sweden)

ChunYing Liu

2013-09-01

Full Text Available Purpose: the distribution routing plans of multi-depots vehicle scheduling problem will increase exponentially along with the adding of customers. So, it becomes an important studying trend to solve the vehicle scheduling problem with heuristic algorithm. On the basis of building the model of multi-depots vehicle scheduling problem, in order to improve the efficiency of the multiple depots vehicle routing, the paper puts forward a fusion algorithm on multiple depots vehicle routing based on the ant colony algorithm with genetic algorithm. Design/methodology/approach: to achieve this objective, the genetic algorithm optimizes the parameters of the ant colony algorithm. The fusion algorithm on multiple depots vehicle based on the ant colony algorithm with genetic algorithm is proposed. Findings: simulation experiment indicates that the result of the fusion algorithm is more excellent than the other algorithm, and the improved algorithm has better convergence effective and global ability. Research limitations/implications: in this research, there are some assumption that might affect the accuracy of the model such as the pheromone volatile factor, heuristic factor in each period, and the selected multiple depots. These assumptions can be relaxed in future work. Originality/value: In this research, a new method for the multiple depots vehicle routing is proposed. The fusion algorithm eliminate the influence of the selected parameter by optimizing the heuristic factor, evaporation factor, initial pheromone distribute, and have the strong global searching ability. The Ant Colony algorithm imports cross operator and mutation operator for operating the first best solution and the second best solution in every iteration, and reserves the best solution. The cross and mutation operator extend the solution space and improve the convergence effective and the global ability. This research shows that considering both the ant colony and genetic algorithm

A novel kind of solid rocket propellant

Energy Technology Data Exchange (ETDEWEB)

Lo, R.E. [Berlin University of Technology (Germany). Rocket Technology at the Aerospace Institute (ILR)

1998-09-01

Cryogenic Solid Propellants (CSPs) combine the simplicity of conventional solid propulsion with the high performance of liquid propulsion. By introducing materials that require cooling for remaining solid, CSPs offer an almost unlimited choice of propellant constituents that mights be selected with respect to specific impulse, density or environmental protection. The prize to be paid for these advantages is the necessity of constant cooling and the requirement of special design features that provide combustion control by moving from deflagration to hybrid like boundary layer combustion. This is achieved by building the solid propellant grains out of macroscopic elements rather than using the quasi homogeneous mixture of conventional composites. The elements may be coated, providing protection and support. Different elements may be designed for individual tasks and serve as modules for ignition, sustained combustion, gas generation, combustion efficiency enhancement, etc. Modular dissected grains offer many new ways of interaction inside the combustion chamber and new degrees of freedom for the designer of such `multiple internal hybrid grains`. At a preliminary level, a study finished in Germany 1997 demonstrated large payload gains when the US space Shuttle and the ARIANE 5 boosters were replaced by CSP-boosters. A very preliminary cost analysis resulted in development costs in the usual magnitude (but not in higher ones). Costs of operation were identified as crucial, but not established. Some experimental work in Germany is scheduled to begin in 1998, almost all details in this article (and many more that were not mentioned - most prominent cost analyses of CSP development and operations) wait for deeper analysis and verification. Actually, a whole new world new of world of chemical propulsion awaits exploration. The topic can be looked up and discussed at the web site of the Advanced Propulsion Workshop of the International Academy of Astronautics. The author

Cryogenics

International Nuclear Information System (INIS)

Shukla, R.K.

1990-01-01

Cryogenics refers to the coldest area known in nature. This temperature range has an upper limit arbitrarily defined as -100 degrees C (-250 degrees C by some) and a lower limit of absolute zero. These limits separate it from the temperature range generally used in refrigerating engineering. One important application of cryogenics is the separation ad purification of air into its various components (oxygen, nitrogen, argon, and the rare gases). Other important developments have been the large-scale production of liquid hydrogen; helium extraction from natural gas; storage and transport of liquefied gases such as oxygen, argon, nitrogen, helium, neon, xenon, and hydrogen; liquefaction of natural gas for ocean transport and peak shaving; and many new types of cryogenic refrigeration devices. This paper introduces the topic of cryogenic engineering. Cryogenic processes generally range from ambient conditions to the boiling point of the cryogenic fluid. Cryogenic cycles also incorporate two or more pressure levels. These properties must also cover the vapor, vapor-liquid, and sometimes the solid regions. Therefore, the physical properties of fluids over a great range of temperatures and pressures must be known. Solubility of contaminants must be known in order to design for their removal. The main physical properties for design purposes are those usually used in unit operations, such as fluid flow, heat transfer, and the like, in addition to those directly related to the Joule-Thomson effect and expansion work. Properties such as density, viscosity, thermal conductivity, heat capacity, enthalpy, entropy, vapor pressure, and vapor-liquid equilibriums are generally obtained in graphical, tabular, or equation form, as a function of temperature and pressure

Helium cryogenics

CERN Document Server

Van Sciver, Steven W

2012-01-01

Twenty five years have elapsed since the original publication of Helium Cryogenics. During this time, a considerable amount of research and development involving helium fluids has been carried out culminating in several large-scale projects. Furthermore, the field has matured through these efforts so that there is now a broad engineering base to assist the development of future projects. Helium Cryogenics, 2nd edition brings these advances in helium cryogenics together in an updated form. As in the original edition, the author's approach is to survey the field of cryogenics with emphasis on helium fluids. This approach is more specialized and fundamental than that contained in other cryogenics books, which treat the associated range of cryogenic fluids. As a result, the level of treatment is more advanced and assumes a certain knowledge of fundamental engineering and physics principles, including some quantum mechanics. The goal throughout the work is to bridge the gap between the physics and engineering aspe...

Cryogenic exciter

Science.gov (United States)

Bray, James William [Niskayuna, NY; Garces, Luis Jose [Niskayuna, NY

2012-03-13

The disclosed technology is a cryogenic static exciter. The cryogenic static exciter is connected to a synchronous electric machine that has a field winding. The synchronous electric machine is cooled via a refrigerator or cryogen like liquid nitrogen. The static exciter is in communication with the field winding and is operating at ambient temperature. The static exciter receives cooling from a refrigerator or cryogen source, which may also service the synchronous machine, to selected areas of the static exciter and the cooling selectively reduces the operating temperature of the selected areas of the static exciter.

[Treatment of Adult Schizophrenic Patients With Depot Antipsychotics].

Science.gov (United States)

Jaramillo González, Luis Eduardo; Gómez Restrepo, Carlos; García Valencia, Jenny; de la Hoz Bradford, Ana María; Ávila-Guerra, Mauricio; Bohórquez Peñaranda, Adriana

2014-01-01

To determine the indications of long-acting antipsychotic injection and what its effectiveness and safety in adult patients with schizophrenia during the treatment maintenance phase. A clinical practice guideline was elaborated under the parameters of the Methodological Guide of the Ministerio de Salud y Protección Social to identify, synthesize and evaluate the evidence and make recommendations about the treatment and follow-up of adult patients with schizophrenia. The evidence of NICE guide 82 was adopted and updated. The evidence was presented to the Guideline Developing Group and recommendations, employing the GRADE system, were produced. The literature review shows that the evidence has moderate to low quality. 8 articles were used. The risk of relapse was lower with depot risperidone and paliperidone palmitate when compared with placebo. For the risk of hospitalizations comparing depot antipsychotics (APD) versus oral AP, the result is inconclusive. Globally the second-generation APD had a lower risk of discontinuation when compared with placebo. The second generation AP had higher risk of extrapyramidal syndromes than placebo, as in the use of antiparkinsonian. The comparison of second-generation AP injections versus placebo showed an increased risk of early weight gain. The use of depot antipsychotics in the maintenance phase of adult patients diagnosed with schizophrenia is recommended if there is no adherence to oral antipsychotics as the patient's preference. It is not recommended depot antipsychotics in the acute phase of schizophrenia in adults. Copyright © 2014 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.

Evaluation of Uniform Cost Accounting System to Fully Capture Depot Level Repair Costs.

Science.gov (United States)

1985-12-01

RD-RI65 522 EVALUATION OF UNIFORM COST ACCOUNTING SYSTEM TO FULLY i/I CAPTURE DEPOT LEVEL REPAIR COSTS (U) NAVAL POSTGRADUATE SCHOOL MONTEREY CA D R...8217.LECTE B ,- THESIS EVALUATION OF UNIFORM COST ACCOUNTING SYSTEM 0TO FULLY CAPTURE DEPOT LEVEL REPAIR COSTS Jby __jDavid Richmond O’Brien lj,,, December...Include Security Classification) EVALUATION OF UNIFORM COST ACCOUNTING SYSTEM TO FULLY CAPTURE DEPOT LEVEL REPAIR COSTS 12 PERSONAL AUTHOR(S) O’Brien- David

Study of optimum propellant production facilities for launch of space shuttle vehicles

Science.gov (United States)

Laclair, L. M.

1970-01-01

An integrated propellant manufacturing plant and distribution system located at Kennedy Space Center is studied. The initial planned propellant and pressurant production amounted to 160 tons/day (TPD) LH2, 10 TPD GH2, 800 TPD LO2, 400 TPD LN2, and 120 TPD GN2. This was based on a shuttle launch frequency of 104 per year. During the study, developments occurred which may lower cryogen requirements. A variety of plant and processing equipment sizes and costs are considered for redundancy and supply level considerations. Steam reforming is compared to partial oxidation as a means of generating hydrogen. Electric motors, steam turbines, and gas turbines are evaluated for driving compression equipment. Various sites on and off Government property are considered to determine tradeoffs between costs and problems directly associated with the site, product delivery and storage costs, raw material costs, and energy costs. Coproduction of other products such as deuterium, methanol, and ammonia are considered. Legal questions are discussed concerning a private company's liabilities and its rights to market commercial products under Government tax and cost shelters.

Effect of Propellant Composition to the Temperature Sensitivity of Composite Propellant

International Nuclear Information System (INIS)

Aziz, Amir; Mamat, Rizalman; Amin, Makeen; Wan Ali, Wan Khairuddin

2012-01-01

The propellant composition is one of several parameter that influencing the temperature sensitivity of composite propellant. In this paper, experimental investigation of temperature sensitivity in burning rate of composite propellant was conducted. Four sets of different propellant compositions had been prepared with the combination of ammonium perchlorate (AP) as an oxidizer, aluminum (Al) as fuel and hydroxy-terminated polybutadiene (HTPB) as fuel and binder. For each mixture, HTPB binder was fixed at 15% and cured with isophorone diisocyanate (IPDI). By varying AP and Al, the effect of oxidizer- fuel mixture ratio (O/F) on the whole propellant can be determined. The propellant strands were manufactured using compression molded method and burnt in a strand burner using wire technique over a range of pressure from 1 atm to 31 atm. The results obtained shows that the temperature sensitivity, a, increases with increasing O/F. Propellant p80 which has O/F ratio of 80/20 gives the highest value of temperature sensitivity which is 1.687. The results shows that the propellant composition has significant effect on the temperature sensitivity of composite propellant

Treatment patterns and clinical characteristics prior to initiating depot typical antipsychotics for nonadherent schizophrenia patients

Directory of Open Access Journals (Sweden)

Montgomery William

2009-07-01

Full Text Available Abstract Background Nonadherence with antipsychotic medication is an important clinical and economic problem in the treatment of schizophrenia. This study identified treatment patterns and clinical characteristics that immediately precede the initiation of depot typical antipsychotics in the usual treatment of schizophrenia patients with a recent history of nonadherence with oral antipsychotic regimens. Methods Data were drawn from a large, multisite, 3-year prospective noninterventional observational study of persons treated for schizophrenia in the United States, which was conducted between 7/1997 and 9/2003. The analytical sample included patients who, in the 6 months prior to enrollment, were considered nonadherent with oral antipsychotics and were not treated with depot antipsychotics (N = 314. Patients who were subsequently initiated on typical depots during the 3-year follow-up were compared with patients who continued therapy with only oral antipsychotic agents. Group comparisons were made on patient baseline characteristics and precedent variables that were assessed 1 to 6 months prior to depot initiation. Patient assessments were made at predetermined intervals throughout the 3-year study using standard psychiatric measures, a patient-reported questionnaire, and medical record information. Results A small proportion of patients (12.4% who were recently nonadherent with oral antipsychotics were subsequently initiated on depot therapy during the 3-year study. Compared to patients treated with only oral antipsychotics, those subsequently initiated on a depot were significantly more likely to be hospitalized at depot initiation or the previous 30 days, to have recent involvement with the criminal justice system (arrests, recent illicit drug use, recent switching or augmentation of oral antipsychotics, and recent treatment with oral typical antipsychotics. Conclusion Despite prior nonadherence with oral antipsychotic medication, only a

Artificial intelligence technology assessment for the US Army Depot System Command

Energy Technology Data Exchange (ETDEWEB)

Pennock, K A

1991-07-01

This assessment of artificial intelligence (AI) has been prepared for the US Army's Depot System Command (DESCOM) by Pacific Northwest Laboratory. The report describes several of the more promising AI technologies, focusing primarily on knowledge-based systems because they have been more successful in commercial applications than any other AI technique. The report also identifies potential Depot applications in the areas of procedural support, scheduling and planning, automated inspection, training, diagnostics, and robotic systems. One of the principal objectives of the report is to help decisionmakers within DESCOM to evaluate AI as a possible tool for solving individual depot problems. The report identifies a number of factors that should be considered in such evaluations. 22 refs.

The Linehaul-Feeder Vehicle Routing Problem with Virtual Depots and Time Windows

Directory of Open Access Journals (Sweden)

Huey-Kuo Chen

2011-01-01

Full Text Available This paper addresses the linehaul-feeder vehicle routing problem with virtual depots and time windows (LFVRPTW. Small and large vehicles deliver services to customers within time constraints; small vehicles en route may reload commodities from either the physical depot or from the larger vehicle at a virtual depot before continuing onward. A two-stage solution heuristic involving Tabu search is proposed to solve this problem. The test results show that the LFVRPTW performs better than the vehicle routing problem with time windows in terms of both objective value and the number of small vehicles dispatched.

Depot Maintenance Air Force Faces Challenges in Managing to 50-50 Ceiling

National Research Council Canada - National Science Library

Warren, David

2000-01-01

... that is being moved from the closing Sacramento, California, and San Antonio, Texas, depots to other military depots or private sector sources. As you requested, my testimony today focuses on the basis for the waiver and the likelihood that the Air Force will need additional waivers in the future.

ATTITUDES OF SHOP FLOOR EMPLOYEES TOWARD WOMEN MANAGERS IN FUEL DEPOTS: A CASE OF THE FUEL DEPOTS IN LUBUMBASHI, DEMOCRATIC REPUBLIC OF THE CONGO

Directory of Open Access Journals (Sweden)

Stephen N. M. Nzuve

2014-12-01

Full Text Available The International Labour Organization and all organizations of human rights advocate against any form of negative attitude in employment based on gender, its terms, promotion and relations. Shop floor employees play a very important role in the daily advancement and profitability of an organisation. The purpose of this study was to establish the attitude of shop floor employees toward women managers in fuel depots in Lubumbashi, Democratic Republic of the Congo. The study adopted a descriptive survey design with the population consisting of one hundred and ninety three (193 shop floor employees. A semi structured questionnaire was used to collect primary data. In total one hundred and twenty one (121 shop floor employees responded yielding a response rate of sixty three percent (63%. The findings of this study indicate that a negative attitude toward woman managers is prevalent in the Fuel Depots of Lubumbashi, Democratic Republic of the Congo. At the fuel depots, the number of women working was less than a third of the males. In spite of this, women managers are rated higher in management qualities and are considered to be more honest, diligent, compassionate, creative and intelligent when compared to their male counterparts. The study recommends a culture change among employees in fuel depots in Lubumbashi in order to enable them perceive women as equal partners at the work place.

Cryogenic heat transfer

CERN Document Server

Barron, Randall F

2016-01-01

Cryogenic Heat Transfer, Second Edition continues to address specific heat transfer problems that occur in the cryogenic temperature range where there are distinct differences from conventional heat transfer problems. This updated version examines the use of computer-aided design in cryogenic engineering and emphasizes commonly used computer programs to address modern cryogenic heat transfer problems. It introduces additional topics in cryogenic heat transfer that include latent heat expressions; lumped-capacity transient heat transfer; thermal stresses; Laplace transform solutions; oscillating flow heat transfer, and computer-aided heat exchanger design. It also includes new examples and homework problems throughout the book, and provides ample references for further study.

Tip-modified Propellers

DEFF Research Database (Denmark)

Andersen, Poul

1999-01-01

The paper deals with tip-modified propellers and the methods which, over a period of two decades, have been applied to develop such propellers. The development is driven by the urge to increase the efficiency of propellers and can be seen as analogous to fitting end plates and winglets to aircraft...... propeller, have efficiency increases of a reasonable magnitude in both open-water and behind-ship conditions....

RATIONAL RECOVERY MODEL OF DEPOT PROCESSING EQUIPMENT AT THE INDUSTRIAL ENTERPRISE

Directory of Open Access Journals (Sweden)

M. I. Kapitsa

2014-07-01

Full Text Available Purpose. The problem of the maximum resources recovery of rolling stock repair depot of industrial enterprise with limited resources consumption, which are used in the system is today’s topical question.The main factors that affect the repair depot operation of industrial enterprise are reviewed. The most significant factors, affecting the quality of the repair depot, are emphasized for further study, specifically - the state of the major repair equipment of a sector. There is a need to minimize the impact of the unsatisfactory state of this factor. Methodology. The formed task of major equipment rational repairing in the mathematical sense is based on the solution of a vector optimization problem. In this case the target functions are the monetary funds spending and time expenditure for repairing. Findings. The mathematical model of optimal equipment maintainability of the repair department at the industrial enterprise was developed by the authors. On the example the choice model of optimal path for equipment repairing of enterprise repair department is described. Originality. As a result of the conducted research the repairing system of major equipment of industrial enterprise sectors was improved. As the mathematical model of rational system recovery of industrial enterprise repair depot we recommend apparatus of class problems of vector optimization. Practical value. Using the proposed model of major equipment repair system of the repair depot at the industrial enterprise will improve the quality of the department by increasing the efficiency of primary resources - time and monetary funds - which are spent by the sector in order to repair its techniques.

Cryogenic immersion microscope

Science.gov (United States)

Le Gros, Mark; Larabell, Carolyn A.

2010-12-14

A cryogenic immersion microscope whose objective lens is at least partially in contact with a liquid reservoir of a cryogenic liquid, in which reservoir a sample of interest is immersed is disclosed. When the cryogenic liquid has an index of refraction that reduces refraction at interfaces between the lens and the sample, overall resolution and image quality are improved. A combination of an immersion microscope and x-ray microscope, suitable for imaging at cryogenic temperatures is also disclosed.

Microreactor System Design for a NASA In Situ Propellant Production Plant on Mars

Science.gov (United States)

TeGrotenhuis, W. E.; Wegeng, R. S.; Vanderwiel, D. P.; Whyatt, G. A.; Viswanathan, V. V.; Schielke, K. P.; Sanders, G. B.; Peters, T. A.; Nicholson, Leonard S. (Technical Monitor)

2000-01-01

The NASA In Situ Resource Utilization (ISRU) program is planning near-term missions to Mars that will include chemical processes for converting the carbon dioxide (CO2) and possibly water from the Martian environment to propellants, oxygen, and other useful chemicals. The use of indigenous resources reduces the size and weight of the payloads from Earth significantly, representing enormous cost savings that make human exploration of Mars affordable. Extraterrestrial chemical processing plants will need to be compact, lightweight, highly efficient under reduced gravity, and extraordinarily reliable for long periods. Microchemical and thermal systems represent capability for dramatic reduction in size and weight, while offering high reliability through massive parallelization. In situ propellant production (ISPP), one aspect of the ISRU program, involves collecting and pressurizing atmospheric CO2, conversion reactions, chemical separations, heat exchangers, and cryogenic storage. A preliminary system design of an ISPP plant based on microtechnology has demonstrated significant size, weight, and energy efficiency gains over the current NASA baseline. Energy management is a strong driver for Mars-based processes, not only because energy is a scarce resource, but because heat rejection is problematic; the low pressure environment makes convective heat transfer ineffective. Energy efficiency gains are largely achieved in the microchemical plant through extensive heat recuperation and energy cascading, which has a small size and weight penalty because the added micro heat exchangers are small. This leads to additional size and weight gains by reducing the required area of waste heat radiators. The microtechnology-based ISPP plant is described in detail, including aspects of pinch analysis for optimizing the heat exchanger network. Three options for thermochemical compression Of CO2 from the Martian atmosphere, adsorption, absorption, and cryogenic freezing, are presented

Male bovine GH transgenic mice have decreased adiposity with an adipose depot-specific increase in immune cell populations.

Science.gov (United States)

Benencia, Fabian; Harshman, Stephanie; Duran-Ortiz, Silvana; Lubbers, Ellen R; List, Edward O; Householder, Lara; Al-Naeeli, Mawadda; Liang, Xiaoyu; Welch, Lonnie; Kopchick, John J; Berryman, Darlene E

2015-05-01

White adipose tissue (WAT) is composed of mature adipocytes and a stromal vascular fraction (SVF), which contains a variety of cells, including immune cells that vary among the different WAT depots. Growth hormone (GH) impacts immune function and adiposity in an adipose depot-specific manner. However, its effects on WAT immune cell populations remain unstudied. Bovine GH transgenic (bGH) mice are commonly used to study the in vivo effects of GH. These giant mice have an excess of GH action, impaired glucose metabolism, decreased adiposity, increased lean mass, and a shortened lifespan. Therefore, the purpose of this study was to characterize the WAT depot-specific differences in immune cell populations in the presence of excess GH in vivo. Three WAT depots were assessed: inguinal (sc), epididymal (EPI), and mesenteric (MES). Subcutaneous and MES bGH WAT depots showed a significantly higher number of total SVF cells, yet only MES bGH WAT had higher leukocyte counts compared with control samples. By means of flow cytometry analysis of the SVF, we detected greater macrophage and regulatory T-cell infiltration in sc and MES bGH WAT depots compared with controls. However, no differences were observed in the EPI WAT depot. RNA-sequencing confirmed significant alterations in pathways related to T-cell infiltration and activation in the sc depot with fewer significant changes in the EPI bGH WAT depot. These findings collectively point to a previously unrecognized role for GH in influencing the distribution of WAT immune cell populations in a depot-specific manner.

A hybrid metaheuristic algorithm for the multi-depot covering tour vehicle routing problem

NARCIS (Netherlands)

Allahyari, S.; Salari, M.; Vigo, D.

2015-01-01

We propose a generalization of themulti-depot capacitated vehicle routing problem where the assumption of visiting each customer does not hold. In this problem, called the Multi-Depot Covering Tour Vehicle Routing Problem (MDCTVRP), the demand of each customer could be satisfied in two different

Preparation and in vitro characterization of SN-38-loaded, self-forming polymeric depots as an injectable drug delivery system.

Science.gov (United States)

Manaspon, Chawan; Hongeng, Suradej; Boongird, Atthaporn; Nasongkla, Norased

2012-10-01

This work describes the preparation and characterization of anticancer-loaded injectable polymeric depots that consisted of D,L-lactide (LA), ε-caprolactone (CL), and poly(ethylene glycol) (PEG) or [poly(ε-caprolactone)-random-poly(D,L-lactide)]-block-poly(ethylene glycol)-block-[poly(ε-caprolactone)-random-poly(D,L-lactide)] (PLEC) copolymers for malignant gliomas treatment. PLECs were polymerized with different percentages of LA to deliver 7-ethyl-10-hydroxycamptothecin (SN-38), a highly potent anticancer drug. SN-38-loaded depots could form directly in phosphate buffer saline with more than 98% encapsulation efficiency. The release rate of SN-38 from depots was found to depend on the amount of LA in PLECs, loading content of SN-38 in the depots, and depot weight. Encapsulation of SN-38 inside depots could enhance the stability of SN-38 where all of SN-38 released after 60 days was in an active form. Depots without SN-38 were evaluated as noncytotoxic against U-87MG, whereas SN-38-loaded depots showed cytotoxic effect as a function of concentration. Copyright © 2012 Wiley Periodicals, Inc.

Depot Maintenance: Improvements to DODs Biennial Core Report Could Better Inform Oversight and Funding Decisions

Science.gov (United States)

2016-11-01

military depots, and not workload performed by the private - sector . MDA officials told us that OSD guidance does not explain how to calculate the...military depots2—public- sector facilities that are government-owned and government-operated—and private - sector contractors. Depots have a key role...the public or private sectors . 3Pub. L. No. 98-525 § 307 (1984). This section was originally codified at 10 U.S.C. § 2304 (note). Letter

Cryogen Safety Course 8876

Energy Technology Data Exchange (ETDEWEB)

Glass, George [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-06-13

Cryogenics (from the Greek word κρvoζ, meaning frost or icy cold) is the study of the behavior of matter at very cold temperatures. The purpose of this course is to provide trainees with an introduction to cryogen use, the hazards and potential accidents related to cryogen systems, cryogen safety components, and the requirements that govern the design and use of cryogen systems at Los Alamos National Laboratory (LANL). The knowledge you gain will help you keep your workplace safe for yourself and your coworkers.

Experiences gained in the conditioning of radioactive wastes from regional depots by example of Kernforschungszentrum Karlsruhe, and recommendations for the establishment of regional depots in the new Federal States of unified Germany

International Nuclear Information System (INIS)

Pfeifer, W.

1992-01-01

Details are given about radioactive waste management and radioactive waste management fundamentals as well as about the respective methods applied by the Baden-Wuerttemberg radioacive waste depot. The waste treatment, quality assurance and internal inspection methods applied by Hauptabteilung Dekontaminationsbetriebe (HDB), Kernforschungszentrum Karlsruhe (KfK) are described, and recommendations are given for the establishment of regional depots in the new provinces of the Federal Republic of Germany. These recommendations which are based on Western German standards before unification suggest regional depots with combined administrative systems which watch over the depot use and charges, the foundation of a waste management association responsible for the disposal, transport, intermediate storage and conditioning of radioactive wastes in the new provinces, and the establishment of a facility to be run by the proposed waste management association for the intermediate storage of conditioned waste packages intended for final disposal. (orig.) [de

NASA Shuttle Logistics Depot (NSLD) - The application of ATE

Science.gov (United States)

Simpkins, Lorenz G.; Jenkins, Henry C.; Mauceri, A. Jack

1990-01-01

The concept of the NASA Shuttle Logistics Depot (NSLD) developed for the Space Shuttle Orbiter Program is described. The function of the NSLD at Cape Canaveral is to perform the acceptance and diagnostic testing of the Shuttle's space-rated line-replaceable units and shop-replaceable units (SRUs). The NSLD includes a comprehensive electronic automatic test station, program development stations, and assorted manufacturing support equipment (including thermal and vibration test equipment, special test equipment, and a card SRU test system). The depot activities also include the establishment of the functions for manufacturing of mechanical parts, soldering, welding, painting, clean room operation, procurement, and subcontract management.

Multicenter clinical trial of leuprolide acetate depot (Luphere depot 3.75 mg for efficacy and safety in girls with central precocious puberty

Directory of Open Access Journals (Sweden)

You Jin Kim

2013-12-01

Full Text Available PurposeWe evaluated the efficacy, safety and psychological aspect of monthly administrations of the gonadotropin-releasing hormone agonists (GnRHa, leuprolide acetate depot (Luphere depot 3.75 mg, in patients with precocious puberty.MethodsA total of 54 girls with central precocious puberty were administered with leuprolide acetate (Luphere depot 3.75 mg every four weeks over 24 weeks. We evaluated the percentage of children exhibiting a suppressed luteinizing hormone (LH response to GnRH (LH peak≤3 IU/L, peak LH/follicle stimulating hormone (FSH ratio of GnRH stimulation test less than 1, change in bone age/chronologic age ratio, change in the Tanner stage and change in eating habit and psychological aspect.Results(1 The percentage of children exhibiting a suppressed LH response to GnRH, defined as an LH peak≤3 IU/L at 24 weeks was 96.3 % (52/54. (2 The percentage of children exhibiting peak LH/FSH ratio<1 at 24 weeks of the study was 94.4 % (51/54. (3 The ratio of bone age and chronological age significantly declined from 1.27±0.07 to 1.24±0.01 after the 6 months of the study. (4 The mean Tanner stage manifested a significant change 2.3±0.48 at baseline, down to 1.70±0.61 at 24 weeks. (5 Based on the questionnaires, the score for eating habits showed a significant change from the baseline 34.0±6.8 to 31.3±6.8. (6 The psychological assessment did not exhibit a significant difference except with scores for sociability, problem behavior total score and other problems.ConclusionThe leuprolide 3.75 mg (Luphere depot is useful and safety for treating children with central precocious puberty.

Clinical outcome of one-third-dose depot triptorelin is the same as half-dose depot triptorelin in the long protocol of controlled ovarian stimulation

Directory of Open Access Journals (Sweden)

Yu Li

2012-01-01

Full Text Available Objective: Appropriate dosage of the long-acting depot gonadotrophin releasing hormone (GnRH agonist has not been determined in long protocol for IVF, and one-third-dose depot triptorelin was compared with half-dose in a luteal long protocol of in-vitro fertilization/ intra cytoplasmic sperm injection (IVF/ICSI treatment in this study. Materials and Methods: This is a prospective, randomized, open clinical trial. 100 patients were randomized into two groups. Group I received one-third-dose (1.25 mg depot triptorelin. Group II received half-dose (1.87 mg. The clinical and experimental parameters were compared between the two groups. Results: There was no premature luteinizing hormone (LH surge in both groups. On Day 3-5 of menstrual cycle after down-regulation, fewer patients showed low-level LH (<1.0 IU/L and estradiol (<30 pg/mL in group I (P <0.05. There were fewer oocytes retrieved (P =0.086, fewer total embryos and available embryos for cryopreservation in Group I (P <0.05, while good-quality embryo rate was higher in group I (P <0.05. The length and dose of ovarian stimulation was lower in Group I, but not significantly. The clinical pregnancy (52% versus 40%, implantation (48% versus 37.5%, delivery (46% versus 32%, or live birth (42% versus 32% rates and the abortion (8% versus 20% rates showed no significant differences. Conclusion: Depot triptorelin 1.25 mg can be successfully used with reduced pituitary suppression and lower cost in a long protocol for in-vitro fertilization.

KAPPEL Propeller. Development of a Marine Propeller with Non-planar Lifting Surfaces

DEFF Research Database (Denmark)

Kappel, J.; Andersen, Poul

2002-01-01

The principle of non-planar lifting surfaces is applied to the design of modern aircraft wings to obtain better lift to drag ratios. Whereas a pronounced fin or "winglet" at the wingtip has been developed for aircraft, the application of the non-planar principle to marine propellers, dealt...... with in this paper, has led to the KAPPEL propeller with blades curved towards the suction side integrating the fin or winglet into the propeller blade. The combined theoretical, experimental and practical approach to develop and design marine propellers with non-planar lifting surfaces has resulted in propellers...

Hypoxia induced VEGF synthesis in visceral adipose depots of obese diabetic patients.

Science.gov (United States)

Fusaru, Ana Marina; Pisoschi, Cătălina Gabriela; Bold, Adriana; Taisescu, C; Stănescu, R; Hîncu, Mihaela; Crăiţoiu, Stefania; Baniţă, Ileana Monica

2012-01-01

VEGF is one the pro-inflammatory adipokines synthesized by the "adipose secretoma" of obese subjects as a response to hypoxic conditions; but the main function of VEGF is angiogenesis, being recognized as the most important factor increasing blood capillaries in the adipose tissue by stimulating endothelial cell growth. In this paper, we propose a comparative study of the vascular response to VEGF synthesis in the subcutaneous and central-peritoneal adipose depots in lean, obese and obese diabetic patients. We used CD31 to label the endothelial cells in order to evaluate the response of the vascular network to VEGF synthesis. Our results showed an increase of VEGF protein synthesis in obese and obese-diabetic patients compared to lean subjects where the protein was absent. The positivity for VEGF in obese diabetic samples was observed in numerous structures from the adipose depots, both in the stromal vascular fraction--blood vessels and stromal cells--as well as in the cytoplasm of adipocytes. Positivity in the vascular wall was observed more frequently in areas of perivascular and intralobular fibrosis. Obese and diabetic patients showed similar incidence of CD31 immunoreactivity with lean subjects in both subcutaneous and peritoneal depots. In conclusion, human adipose depots show a different incidence of VEGF positive cells in relation with their disposal and the metabolic status. VEGF synthesis in visceral adipose tissue is inefficient being not followed by angiogenesis to counterbalance tissue hypoxia. We suggest that may be a pathogenic link between the degrees of intralobular fibrosis in adipose depots and VEGF expression.

Storage depot for radioactive material

International Nuclear Information System (INIS)

Szulinski, M.J.

1983-01-01

Vertical drilling of cylindrical holes in the soil, and the lining of such holes, provides storage vaults called caissons. A guarded depot is provided with a plurality of such caissons covered by shielded closures preventing radiation from penetrating through any linear gap to the atmosphere. The heat generated by the radioactive material is dissipated through the vertical liner of the well into the adjacent soil and thus to the ground surface so that most of the heat from the radioactive material is dissipated into the atmosphere in a manner involving no significant amount of biologically harmful radiation. The passive cooling of the radioactive material without reliance upon pumps, personnel, or other factor which might fail, constitutes one of the most advantageous features of this system. Moreover this system is resistant to damage from tornadoes or earthquakes. Hermetically sealed containers of radioactive material may be positioned in the caissons. Loading vehicles can travel throughout the depot to permit great flexibility of loading and unloading radioactive materials. Radioactive material can be shifted to a more closely spaced caisson after ageing sufficiently to generate much less heat. The quantity of material stored in a caisson is restricted by the average capacity for heat dissipation of the soil adjacent such caisson

Adipose tissue in muscle: a novel depot similar in size to visceral adipose tissue

NARCIS (Netherlands)

Gallagher, D.; Kuznia, P.; Heshka, S.; Albu, J.; Heymsfield, S.B.; Goodpaster, B.H.; Visser, M.; Harris, T.B.

2005-01-01

BACKGROUND: The manner in which fat depot volumes and distributions, particularly the adipose tissue (AT) between the muscles, vary by race is unknown. OBJECTIVE: The objective was to quantify a previously unstudied and novel intermuscular AT (IMAT) depot and subcutaneous AT, visceral AT (VAT), and

Advanced Cooled Shield - Integrated MLI: Passive or Active Cooled System, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Cryogenic propellants are important to NASA's missions. Improvements in cryogenic propellant storage and transfer are critical to future long duration NASA...

Investigating the effects of critical phenomena in premixed methane-oxygen flames at cryogenic conditions

Science.gov (United States)

Gopal, Abishek; Yellapantula, Shashank; Larsson, Johan

2017-11-01

Methane is increasingly becoming viable as a rocket fuel in the latest generation of launch vehicles. In liquid rocket engines, fuel and oxidizer are injected under cryogenic conditions into the combustion chamber. At high pressures, typical of rocket combustion chambers, the propellants exist in supercritical states where the ideal gas thermodynamics are no longer valid. We investigate the effects of real-gas thermodynamics on transcritical laminar premixed methane-oxygen flames. The effect of the real-gas cubic equations of state and high-pressure transport properties on flame dynamics is presented. We also study real-gas effects on the extinction limits of the methane-oxygen flame.

Occupational Exposure of Petroleum Depot Workers to BTEX Compounds

Directory of Open Access Journals (Sweden)

M Rezazadeh Azari

2011-12-01

Full Text Available Background: Benzene, toluene, ethylbenzene and xylene (BTEX are the most important toxic volatile compounds in the air and could be easily absorbed through the respiratory tract. In recent years, the risk of exposure to BTEX compounds, especially benzene as a carcinogen, has been considered in petroleum depot stations. Objective: To assess the occupational exposure of petroleum depot workers in Iran to BTEX compounds. Methods: After completing a questionnaire and assessing occupational exposure to BTEX compounds, 78 (46 exposed and 32 non-exposed depot workers were randomly selected to participate in this study. Air sampling and analysis of BTEX was conducted according to the NIOSH method No. 1501. Analysis of urinary hippuric acid, as an indicator of toluene exposure, was carried out according to NIOSH method No. 8300. Personal monitoring of the high exposure group to BTEX compounds was repeated to verify the results obtained in the first phase of the monitoring. Results: Among the 9 operating groups studied, occupational exposure to benzene and toluene was higher in quality control and gasoline loading operators—the median exposure ranged from 0.16 to 1.63 ppm for benzene and 0.2 to 2.72 ppm for toluene. Median exposure of other group members to BTEX compounds was below the detection limit of analytical method (0.07, 0.06, 0.05, and 0.05 ppm, respectively. The level of toluene exposure measured showed correlation with neither post-shift urinary hippuric acid (Spearman's rho=0.128, p=0.982 nor with the difference between post- and pre-shift urinary hippuric acid (Spearman's rho=0.089, p=0.847 in depot operational workers. Conclusion: Gasoline loading operators are exposed to a relatively high level of benzene.

Supply Inventory Management: Accountability and Control of Materiel at the Naval Air Depot, North Island

National Research Council Canada - National Science Library

2002-01-01

... of the $6.8 billion was for operation of three Naval Air Depots. A significant portion of the $1.5 billion was for purchasing materiel used in repair and overhaul processes at the depot maintenance facilities...

Supply Inventory Managment: Accountability and Control of Materiel at the Naval Air Depot, North Island

National Research Council Canada - National Science Library

Young, Shelton

2002-01-01

... of the $6.8 billion was for operation of three Naval Air Depots. A significant portion of the $1.5 billion was for purchasing materiel used in repair and overhaul processes at the depot maintenance facilities...

Hull-Propeller Interaction and Its Effect on Propeller Cavitation

DEFF Research Database (Denmark)

Regener, Pelle Bo

In order to predict the required propulsion power for a ship reliably and accurately, it is not sufficient to only evaluate the resistance of the hull and the propeller performance in open water alone. Interaction effects between hull and propeller can even be a decisive factor in ship powering...... prediction and design optimization. The hull-propeller interaction coefficients of effective wake fraction, thrust deduction factor, and relative rotative efficiency are traditionally determined by model tests. Self-propulsion model tests consistently show an increase in effective wake fractions when using...... velocities. This offers an opportunity for additional insight into hull-propeller interaction and the propeller’s actual operating condition behind the ship, as the actual (effective) inflow is computed. Self-propulsion simulations at model and full scale were carried out for a bulk carrier, once...

The influence of the choice of propeller design tool on propeller performance

OpenAIRE

Skåland, Edvard Knutsen

2016-01-01

In this master thesis different propeller design and analysis methods are presented and compared in terms of the accuracy and computational efficiency of their theory. These methods include lifting line, vortex lattice lifting surface and panel methods. A propeller design program based on lifting line theory was developed by the author. This program has been used together with the propeller design programs OpenProp and AKPD to make six propeller designs. The designs are based o...

Implementation of Geographical Information System for Bacteriological Contamination Analysis on Refill Drinking Water Depot (Study in Tembalang District)

Science.gov (United States)

Rahmitha, Amelia; Utami, Endang Sri; Sitohang, Marya Yenita

2018-02-01

People used refilled-drinking-water for household and food stall because its efficient and low cost. Based on Indonesian Health Ministry regulation, it should not have any coliform bacteria. This study aimed to describe the bacteriological contamination of refilled drinking water using geographical information system (GIS). In this research, it was used an analytic observational method. The samples were from all available (37) depots in Tembalang district, one form each depot took used a sterile bottle. Contamination of bacteria was identified by Most Probable Number (MPN) method lactose broth media, Mac Conkey media, and IMVIC media. The depot samples were then plotted on (GIS). This study showed 95% samples were not feasible to consume since they contamined coliform. All sub-district had one that contaminated by coliform, 75% sub-districts had depots that contaminated Escherichia coli, while 55% sub-districts had depots that contaminated with other bacteria. The internal risk factors of the contamination were the absence of hygiene-sanitation worthy certificate (95%), depots location near to pollution sources (5%), and the misused of UV light. The external risk factor was lack of quality control that was not as the sterilization from office health Semarang city. Policy reinforcement should be done to all of the depots.

Cryogenic Electric Motor Tested

Science.gov (United States)

Brown, Gerald V.

2004-01-01

Technology for pollution-free "electric flight" is being evaluated in a number of NASA Glenn Research Center programs. One approach is to drive propulsive fans or propellers with electric motors powered by fuel cells running on hydrogen. For large transport aircraft, conventional electric motors are far too heavy to be feasible. However, since hydrogen fuel would almost surely be carried as liquid, a propulsive electric motor could be cooled to near liquid hydrogen temperature (-423 F) by using the fuel for cooling before it goes to the fuel cells. Motor windings could be either superconducting or high purity normal copper or aluminum. The electrical resistance of pure metals can drop to 1/100th or less of their room-temperature resistance at liquid hydrogen temperature. In either case, super or normal, much higher current density is possible in motor windings. This leads to more compact motors that are projected to produce 20 hp/lb or more in large sizes, in comparison to on the order of 2 hp/lb for large conventional motors. High power density is the major goal. To support cryogenic motor development, we have designed and built in-house a small motor (7-in. outside diameter) for operation in liquid nitrogen.

Innovative boron nitride-doped propellants

Directory of Open Access Journals (Sweden)

Thelma Manning

2016-04-01

Full Text Available The U.S. military has a need for more powerful propellants with balanced/stoichiometric amounts of fuel and oxidants. However, balanced and more powerful propellants lead to accelerated gun barrel erosion and markedly shortened useful barrel life. Boron nitride (BN is an interesting potential additive for propellants that could reduce gun wear effects in advanced propellants (US patent pending 2015-026P. Hexagonal boron nitride is a good lubricant that can provide wear resistance and lower flame temperatures for gun barrels. Further, boron can dope steel, which drastically improves its strength and wear resistance, and can block the formation of softer carbides. A scalable synthesis method for producing boron nitride nano-particles that can be readily dispersed into propellants has been developed. Even dispersion of the nano-particles in a double-base propellant has been demonstrated using a solvent-based processing approach. Stability of a composite propellant with the BN additive was verified. In this paper, results from propellant testing of boron nitride nano-composite propellants are presented, including closed bomb and wear and erosion testing. Detailed characterization of the erosion tester substrates before and after firing was obtained by electron microscopy, inductively coupled plasma and x-ray photoelectron spectroscopy. This promising boron nitride additive shows the ability to improve gun wear and erosion resistance without any destabilizing effects to the propellant. Potential applications could include less erosive propellants in propellant ammunition for large, medium and small diameter fire arms.

Depot-medication compliance for patients with psychotic disorders: the importance of illness insight and treatment motivation.

Science.gov (United States)

Noordraven, Ernst L; Wierdsma, André I; Blanken, Peter; Bloemendaal, Anthony Ft; Mulder, Cornelis L

2016-01-01

Noncompliance is a major problem for patients with a psychotic disorder. Two important risk factors for noncompliance that have a severe negative impact on treatment outcomes are impaired illness insight and lack of motivation. Our cross-sectional study explored how they are related to each other and their compliance with depot medication. Interviews were conducted in 169 outpatients with a psychotic disorder taking depot medication. Four patient groups were defined based on low or high illness insight and on low or high motivation. The associations between depot-medication compliance, motivation, and insight were illustrated using generalized linear models. Generalized linear model showed a significant interaction effect between motivation and insight. Patients with poor insight and high motivation for treatment were more compliant (94%) (95% confidence interval [CI]: 1.821, 3.489) with their depot medication than patients with poor insight and low motivation (61%) (95% CI: 0.288, 0.615). Patients with both insight and high motivation for treatment were less compliant (73%) (95% CI: 0.719, 1.315) than those with poor insight and high motivation. Motivation for treatment was more strongly associated with depot-medication compliance than with illness insight. Being motivated to take medication, whether to get better or for other reasons, may be a more important factor than having illness insight in terms of improving depot-medication compliance. Possible implications for clinical practice are discussed.

Sustained release of antibiotics from injectable and thermally responsive polypeptide depots.

Science.gov (United States)

Adams, Samuel B; Shamji, Mohammed F; Nettles, Dana L; Hwang, Priscilla; Setton, Lori A

2009-07-01

Biodegradable polymeric scaffolds are of interest for delivering antibiotics to local sites of infection in orthopaedic applications, such as bone and diarthrodial joints. The objective of this study was to develop a biodegradable scaffold with ease of drug loading in aqueous solution, while providing for drug depot delivery via syringe injection. Elastin-like polypeptides (ELPs) were used for this application, biopolymers of repeating pentapeptide sequences that were thermally triggered to undergo in situ depot formation at body temperature. ELPs were modified to enable loading with the antibiotics, cefazolin, and vancomycin, followed by induction of the phase transition in vitro. Cefazolin and vancomycin concentrations were monitored, as well as bioactivity of the released antibiotics, to test an ability of the ELP depot to provide for prolonged release of bioactive drugs. Further tests of formulation viscosity were conducted to test suitability as an injectable drug carrier. Results demonstrate sustained release of therapeutic concentrations of bioactive antibiotics by the ELP, with first-order time constants for drug release of approximately 25 h for cefazolin and approximately 500 h for vancomycin. These findings illustrate that an injectable, in situ forming ELP depot can provide for sustained release of antibiotics with an effect that varies across antibiotic formulation. ELPs have important advantages for drug delivery, as they are known to be biocompatible, biodegradable, and elicit no known immune response. These benefits suggest distinct advantages over currently used carriers for antibiotic drug delivery in orthopedic applications. (c) 2008 Wiley Periodicals, Inc.

Adesão ao tratamento e hospitalizações entre pacientes que realizam aplicações de Flufenazina Depot Adhesión al tratamiento y hospitalización entre pacientes que realizan aplicaciones de Flufenazina Depot Compliance with treatment and hospitalization among patients using Flufenazine Depot

Directory of Open Access Journals (Sweden)

José Menna Oliveira

2003-08-01

Full Text Available OBJETIVOS: Os autores revisam a bibliografia sobre medicação depot e apresentam dados referentes à adesão ao tratamento e hospitalizações entre os pacientes que realizam aplicações de enantato de flufenazina em regime ambulatorial no Hospital Espírita de Pelotas. MÉTODO: Analisaram-se os prontuários de pacientes que foram incluídos no regime depot anteriormente a maio de 2001 e que realizaram pelo menos uma aplicação entre maio de 2001 e junho de 2002, quanto à adesão ao tratamento e eventuais hospitalizações. RESULTADOS: De um total de 100 pacientes, 66 permaneciam em regime depot ao término do período estudado. Destes, 40 (61% apresentavam boa adesão ao tratamento, enquanto 26 (39% apresentavam má adesão. Houve um total de 25 pacientes que sofreram hospitalizações, entre os quais a maioria não estava em tratamento no término do estudo ou apresentava má adesão. Entre os pacientes procedentes do mesmo bairro em que se situa o hospital, 10 (67% apresentavam boa adesão em comparação com 30 pacientes (59% procedentes de bairros distintos. DISCUSSÃO: O número de hospitalizações variou visivelmente, conforme a permanência ou não em tratamento e a adesão ao mesmo. Pacientes provenientes de bairros distantes do hospital tenderam a apresentar pior adesão ao tratamento. CONCLUSÕES: É possível que pacientes em regime de aplicação depot residentes próximos ao local de aplicação beneficiem-se mais do tratamento que aqueles residentes em locais distantes. São necessários mais estudos comparando administrações depot com VO em termos de adesão e investigando fatores preditores de boa adesão ao tratamento.OBJETIVOS: Los autores revisan la bibliografía sobre medicación depot y presentan datos referentes a la adhesión al tratamiento y hospitalizaciones entre los pacientes que realizan aplicaciones de enantato de flufenazina en régimen ambulatorio en el Hospital Espiritista de Pelotas. MÉTODO: Fueron

Cryogenics theory, processes and applications

CERN Document Server

Hayes, Allyson E

2011-01-01

Cryogenics is the study of the production of very low temperature (below -150 -C, -238 -F or 123 K) and the behaviour of materials at those temperatures. This book presents current research from across the globe in the study of cryogenics, including the effect of cryogenic treatment on microstructure and mechanical properties of light weight alloys; the application of Fiber Bragg grating sensors at cryogenic temperatures; cryogenic grinding; liquid oxygen magnetohydrodynamics; and, genetic engineering techniques used to improve tolerance to cryopreservation.

Cost-Utility Analysis of Depot Atypical Antipsychotics for Chronic Schizophrenia in Croatia.

Science.gov (United States)

Jukic, Vlado; Jakovljevic, Miro; Filipcic, Igor; Herceg, Miroslav; Silic, Ante; Tomljanovic, Tatjana; Zilbershtein, Roman; Jensen, Rasmus C D; Hemels, Michiel E H; Einarson, Thomas R

As a nation with a developing economy, Croatia is faced with making choices between pharmaceutical products, including depot injectable antipsychotics. We conducted a pharmacoeconomic analysis to determine the cost-effectiveness of atypical depots in Croatia. A 1-year decision-analytic framework modeled drug use. We determined the average direct cost to the Croatian Institute for Health Insurance of using depot formulations of paliperidone palmitate long-acting injectable (PP-LAI), risperidone LAI (RIS-LAI), or olanzapine LAI (OLZ-LAI). An expert panel plus literature-derived clinical rates populated the core model, along with costs adjusted to 2012 by using the Croatian consumer price index. Clinical outcomes included quality-adjusted life-years, hospitalization rates, emergency room treatment rates, and relapse days. Robustness of results was examined with one-way sensitivity analyses on important inputs; overall, all inputs were varied over 10,000 simulations in a Monte Carlo analysis. Costs (quality-adjusted life-years) per patient were €5061 (0.817) for PP-LAI, €5168 (0.807) for RIS-LAI, and €6410 (0.812) for OLZ-LAI. PP-LAI had the fewest relapse days, emergency room visits, and hospitalizations. Results were sensitive against RIS-LAI with respect to drug costs and adherence rates, but were generally robust overall, dominating OLZ-LAI in 77.3% and RIS-LAI in 56.8% of the simulations. PP-LAI dominated the other drugs because it had the lowest cost and best clinical outcomes. Compared with depots of olanzapine and risperidone and oral olanzapine, PP-LAI was the cost-effective atypical LAI for treating chronic schizophrenia in Croatia. Using depot paliperidone in place of either olanzapine or risperidone would reduce the overall costs of caring for these patients. Copyright © 2013, International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc.

Six-month gonadotropin releasing hormone (GnRH agonist depots provide efficacy, safety, convenience, and comfort

Directory of Open Access Journals (Sweden)

Phillips JM

2011-07-01

Full Text Available E David Crawford, Jason M PhillipsUniversity of Colorado Health Sciences Center, Aurora, CO, USAAbstract: Two different 6-month GnRH agonist depot formulations approved for palliative treatment of advanced and metastatic prostate cancer in the United States – leuprolide acetate 45 mg and triptorelinpalmoate 22.5 mg – provide patients with efficacy and safety comparable to those of existing 1-, 3-, and 4-month GnRH agonist depots. However, the 6-month formulations can increase patient convenience, comfort, and compliance by reducing the number of physician visits and injections required. At the conclusion of their pivotal trials, the 6-month formulations demonstrated efficacy rates in achieving chemical castration (serum testosterone #50 ng/dL that ranged between 93% and 99%. As with existing GnRH agonist depot formulations, hot flashes represented the most common adverse event reported in trials of 6-month leuprolide acetate or triptorelin. As such, these products may prove useful not only for their labeled indication, but also as adjuncts to other treatments such as radical prostatectomy, radiotherapy, and chemotherapy. We recommend further research, including head-to-head trials between the 6-month GnRH depots, to refine our understanding of these products.Keywords: prostate cancer, leuprorelin, leuprolide, triptorelin, 6-month depot, testosterone

New Insights into Drug Absorption from Oil Depots

NARCIS (Netherlands)

Kalicharan, R.W.

2017-01-01

Sustained delivery formulations are used in order to prolong the pharmacological activity of a drug. A commonly used parenteral sustained delivery formulation is an oil depot which consists of a solution of lipophilic molecules in a vegetable oil. These are normally administered either

Energy Efficient Cryogenics

Science.gov (United States)

Meneghelli, Barry J.; Notardonato, William; Fesmire, James E.

2016-01-01

The Cryogenics Test Laboratory, NASA Kennedy Space Center, works to provide practical solutions to low-temperature problems while focusing on long-term technology targets for the energy-efficient use of cryogenics on Earth and in space.

Introduction to cryogenic engineering

CERN Multimedia

CERN. Geneva; Vandoni, Giovanna; Niinikoski, Tapio O

2005-01-01

Cryogenic engineering is one of the key technologies at CERN. It is widely used in research and has many applications in industry and last but not least in medicine. In research cryogenic engineering and its applications are omnipresent from the smallest laboratories to fusion reactors, hughe detectors and accelerators. With the termination of the LHC, CERN will in fact become the world's largest cryogenic installation. This series of talks intends to introduce the non-cryogenist to the basic principles and challenges of cryogenic engineering and its applications. The course will also provide a basis for practical application as well as for further learning.

An Analysis of the Cost Accounting System for the Depot Maintenance Service, Air Force Industrial Fund.

Science.gov (United States)

1987-09-01

AN A NALYSIS OF THE COST ACCOUNTING SYSTEM FOR THE DEPOT 1/1 MRINTENANCE SERVI..(U) MIR FORCE INST OF TECH IIGHT-PTTERSON RFB OH SCHOOL OF SYST.. 0 L...I "VV h S~ ~~i FiLE COV, THSI CIO ~OF AN ANALYSIS OF THE COST ACCOUNTING SYSTEM FOR THE DEPOT MAINTENANCE SERVICE, AIR FORCE INDUSTRIAL FUND...Patterson Air Force Base, Ohio ~ p~UOW~~ ’ I ~ 1 12 02 0 AFIT/GLM/LSY/87S-83 AN ANALYSIS OF THE COST ACCOUNTING SYSTEM FOR THE DEPOT MAINTENANCE SERVICE, AIR

Development and implementation of a propeller test capability for GL-10 "Greased Lightning" propeller design

Science.gov (United States)

Duvall, Brian Edward

Interest in small unmanned aerial vehicles has increased dramatically in recent years. Hybrid vehicles which allow forward flight as a fixed wing aircraft and a true vertical landing capability have always had applications. Management of the available energy and noise associated with electric propeller propulsion systems presents many challenges. NASA Langley has developed the Greased Lightning 10 (GL-10) vertical takeoff, unmanned aerial vehicle with ten individual motors and propellers. All are used for propulsion during takeoff and contribute to acoustic noise pollution which is an identified nuisance to the surrounding users. A propeller test capability was developed to gain an understanding of how the noise can be reduced while meeting minimum thrust requirements. The designed propeller test stand allowed for various commercially available propellers to be tested for potential direct replacement of the current GL-10 propellers and also supported testing of a newly designed propeller provided by the Georgia Institute of Technology. Results from the test program provided insight as to which factors affect the noise as well as performance characteristics. The outcome of the research effort showed that the current GL-10 propeller still represents the best choice of all the candidate propellers tested.

MFTF magnet cryogenics

International Nuclear Information System (INIS)

VanSant, J.H.

1981-07-01

The prime requirement of the cryogenics of the magnets is to assure a superconducting state for the magnet coils, a large task considering their enormous size. The following presentation addresses the principal topics that have been considered in this cryogenic design

Measuring Customer Satisfaction of Depot Maintenance: An Analysis of Customer Satisfaction of F/A-18 Maintenance at Naval Aviation Depot North Island, CA

National Research Council Canada - National Science Library

Forsyth, Brian

1997-01-01

.... A key focus of commercial practices is delivering customer satisfaction. To this extent, it is imperative that DoD depots understand and properly measure their customer's concerns if they wish to improve their performance...

Employment-based reinforcement of adherence to depot naltrexone in unemployed opioid-dependent adults: a randomized controlled trial.

Science.gov (United States)

Everly, Jeffrey J; DeFulio, Anthony; Koffarnus, Mikhail N; Leoutsakos, Jeannie-Marie S; Donlin, Wendy D; Aklin, Will M; Umbricht, Annie; Fingerhood, Michael; Bigelow, George E; Silverman, Kenneth

2011-07-01

Naltrexone can be used to treat opioid dependence, but patients refuse to take it. Extended-release depot formulations may improve adherence, but long-term adherence rates to depot naltrexone are not known. This study determined long-term rates of adherence to depot naltrexone and whether employment-based reinforcement can improve adherence. Participants who were inducted onto oral naltrexone were assigned randomly to contingency (n = 18) or prescription (n = 17) groups. Participants were offered six depot naltrexone injections and invited to work at the therapeutic workplace on week days for 26 weeks, where they earned stipends for participating in job skills training. Contingency participants were required to accept naltrexone injections to maintain workplace access and to maintain maximum pay. Prescription participants could work independently of whether they accepted injections. The therapeutic workplace, a model employment-based intervention for drug addiction and unemployment. Opioid-dependent unemployed adults. Depot naltrexone injections accepted and opiate-negative urine samples. Contingency participants accepted significantly more naltrexone injections than prescription participants (81% versus 42%), and were more likely to accept all injections (66% versus 35%). At monthly assessments (with missing urine samples imputed as positive), the groups provided similar percentages of samples negative for opiates (74% versus 62%) and for cocaine (56% versus 54%). Opiate-positive samples were more likely when samples were also positive for cocaine. Employment-based reinforcement can maintain adherence to depot naltrexone. Future research should determine whether persistent cocaine use compromises naltrexone's effect on opiate use. Workplaces may be useful for promoting sustained adherence to depot naltrexone. © 2011 The Authors, Addiction © 2011 Society for the Study of Addiction.

The cryogenic control system of EAST

International Nuclear Information System (INIS)

Zhuang, M.; Hu, L.B.; Zhow, Z.W.; Xia, G.H.

2012-01-01

Highlights: ► A reliable and flexible duplex control system is required for cryogenic system. ► The cryogenic control system is based on Delta-V DCS. ► It has been proved to be an effective way to control cryogenic process. ► It will provide useful experience and inspiration for the development in the cryogenic control engineering. - Abstract: A large scale helium cryogenic system is one of the key components for the EAST tokamak device for the cooling of PF and TF coils, structures, thermal shields, buslines, current leads and cryopumps. Since the cooling scheme of the EAST cryogenic system is fairly complicated, a reliable and flexible control system is required for cryogenic system. The cryogenic control system is based on DeltaV DCS which is the process control software developed by Emerson Company. The EAST cryogenic system has been in operation for four years and has been proved to be safe, stable and energy saving by the past 7 experiments. This paper describes the redundant control network, hardware configuration, software structure, auxiliary system and the new development in the future.

Cryogenic Preamplifiers for Magnetic Resonance Imaging

DEFF Research Database (Denmark)

Johansen, Daniel H.; Sanchez-Heredia, Juan D.; Petersen, Jan R.

2018-01-01

Pursuing the ultimate limit of detection in magnetic resonance imaging (MRI) requires cryogenics to decrease the thermal noise of the electronic circuits. As cryogenic coils for MRI are slowly emerging cryogenic preamplifiers are required to fully exploit their potential. A cryogenic preamplifier...

Depot-Specific Response of Adipose Tissue to Diet-Induced Inflammation: The Retinoid-Related Orphan Receptor α (RORα) Involved?

Science.gov (United States)

Kadiri, Sarah; Auclair, Martine; Capeau, Jacqueline; Antoine, Bénédicte

2017-11-01

Epididymal adipose tissue (EAT), a visceral fat depot, is more closely associated with metabolic dysfunction than inguinal adipose tissue (IAT), a subcutaneous depot. This study evaluated whether the nuclear receptor RORα, which controls inflammatory processes, could be implicated. EAT and IAT were compared in a RORα loss-of-function mouse (sg/sg) and in wild-type (WT) littermates, fed a standard diet (SD) or a Western diet (WD), to evaluate the impact of RORα expression on inflammatory status and on insulin sensitivity (IS) of each fat depot according to the diet. Sg/sg mice fed the SD exhibited a decreased inflammatory status and a higher IS in their fat depots than WT mice. WD-induced obesity had distinct effects on the two fat depots. In WT mice, EAT exhibited increased inflammation and insulin resistance while IAT showed reduced inflammation and improved IS, together with a depot-specific increase of RORα, and its target gene IκBα, in the stroma vascular fraction (SVF). Conversely, in sg/sg mice, WD increased inflammation and lowered IS of IAT but not of EAT. These findings suggest an anti-inflammatory role for RORα in response to WD, which occurs at the level of SVF of IAT, thus possibly contributing to the "healthy" expansion of IAT. © 2017 The Obesity Society.

Analysis of Tobyhanna Army Depot's Radio Frequency Identification (RFID) Pilot Program: RFID as an Asset Management Tool

National Research Council Canada - National Science Library

Miertschin, Keith W; Forrest, Brian D

2005-01-01

...) used for inventory and asset management at the Tobyhanna Army Maintenance Depot. Tobyhanna Army Depot recently partnered with WhereNet Corporation for a pilot program to incorporate a real-time locating system that uses RFID...

Integrated cryogenic sensors

International Nuclear Information System (INIS)

Juanarena, D.B.; Rao, M.G.

1991-01-01

Integrated cryogenic pressure-temperature, level-temperature, and flow-temperature sensors have several advantages over the conventional single parameter sensors. Such integrated sensors were not available until recently. Pressure Systems, Inc. (PSI) of Hampton, Virginia, has introduced precalibrated precision cryogenic pressure sensors at the Los Angeles Cryogenic Engineering Conference in 1989. Recently, PSI has successfully completed the development of integrated pressure-temperature and level-temperature sensors for use in the temperature range 1.5-375K. In this paper, performance characteristics of these integrated sensors are presented. Further, the effects of irradiation and magnetic fields on these integrated sensors are also reviewed

Experimental investigation on No-Vent Fill (NVF) process using liquid Nitrogen

International Nuclear Information System (INIS)

Kim, Young Cheol; Seo, Man Su; Yoo, Dong Gyu; Jeong, Sang Kwon

2014-01-01

For a long-term space mission, filling process of cryogenic liquid propellant is operated on a space vehicle in space. A vent process during transfer and filling of cryogenic propellant is needed to maintain the fuel tank pressure at a safe level due to its volatile characteristic. It is possible that both liquid and vapor phases of the cryogenic propellant are released simultaneously to outer space when the vent process occurs under low gravity environment. As a result, the existing filling process with venting not only accompanies wasting liquid propellant, but also consumes extra fuel to compensate for the unexpected momentum originated from the vent process. No-Vent Fill (NVF) method, a filling procedure without a venting process of cryogenic liquid propellant, is an attractive technology to perform a long-term space mission. In this paper, the preliminary experimental results of the NVF process are described. The experimental set-up consists of a 9-liter cryogenic liquid receiver tank and a supply tank. Liquid nitrogen (LN2) is used to simulate the behavior of cryogenic propellant. The whole situation in the receiver tank during NVF is monitored. The major experimental parameter in the experiment is the mass flow rate of the liquid nitrogen. The experimental results demonstrate that as the mass flow rate is increased, NVF process is conducted successfully. The quality and the inlet temperature of the injected LN2 are affected by the mass flow rate. These parameters determine success of NVF.

Redistributing Stock in Library Systems with a Depot

NARCIS (Netherlands)

van der Heide, Gerlach; Roodbergen, Kees Jan; van Foreest, Nicky

Public library organizations often utilize depots for carrying out shipments to libraries in case of stock-outs and for storing low demand rental items at low cost. Similar systems may be employed by rental companies for other rental products such as tools, DVDs, and jewelry. Since shipments deplete

Cryogenic forced convection refrigerating system

International Nuclear Information System (INIS)

Klee, D.J.

1988-01-01

This patent describes the method of refrigerating products by contact with a refrigerating gas which comprises introducing product into a refrigeration zone, contacting the product with the refrigerating gas for a sufficient time to refrigerate it to the appropriate extent and removing the refrigerated product. The improvement for producing the refrigeration gas from a liquid cryogen such that essentially all of the liquid cryogen is fully vaporized before contacting the product comprises: (a) introducing the liquid cryogen, selected from the group consisting of liquid air and liquid nitrogen, at elevated pressure into an ejector as the motive fluid to accelerate a portion of a warm refrigerating gas through the ejector while mixing the cryogen and gas to effect complete vaporization of the liquid cryogen and substantial cooling of the portion of the refrigerating gas resulting in a cold discharge gas which is above the liquefaction temperature of the cryogen; (b) introducing the cold discharge gas into a forced circulation pathway of refrigerating gas and producing a cold refrigerating gas which contacts and refrigerates product and is then at least partially recirculated; (c) sensing the temperature of the refrigerating gas in the forced circulation pathway and controlling the introduction of liquid cryogen with regard to the sensed temperature to maintain the temperature of the discharge gas above the liquefacton temperature of the cryogen utilized

Measurement of ground and nearby building vibration and noise induced by trains in a metro depot.

Science.gov (United States)

Zou, Chao; Wang, Yimin; Wang, Peng; Guo, Jixing

2015-12-01

Metro depots are where subway trains are parked and where maintenance is carried out. They usually occupy the largest ground areas in metro projects. Due to land utilization problems, Chinese cities have begun to develop over-track buildings above metro depots for people's life and work. The frequently moving trains, when going into and out of metro depots, can cause excessive vibration and noise to over-track buildings and adversely affect the living quality of the building occupants. Considering the current need of reliable experimental data for the construction of metro depots, field measurements of vibration and noise on the ground and inside a nearby 3-story building subjected to moving subway trains were conducted in a metro depot at Guangzhou, China. The amplitudes and frequency contents of velocity levels were quantified and compared. The composite A-weighted equivalent sound levels and maximum sound levels were captured. The predicted models for vibration and noise of metro depot were proposed based on existing models and verified. It was found that the vertical vibrations were significantly greater than the horizontal vibrations on the ground and inside the building near the testing line. While at the throat area, the horizontal vibrations near the curved track were remarkably greater than the vertical vibrations. The attenuation of the vibrations with frequencies above 50 Hz was larger than the ones below 50 Hz, and the frequencies of vibration transmitting to adjacent buildings were mainly within 10-50 Hz. The largest equivalent sound level generated in the throat area was smaller than the testing line one, but the instantaneous maximum sound level induced by wheels squeal, contact between wheels and rail joints as well as turnout was close to or even greater than the testing line one. The predicted models gave a first estimation for design and assessment of newly built metro depots. Copyright © 2015 Elsevier B.V. All rights reserved.

Propellers in Saturn's rings

Science.gov (United States)

Sremcevic, M.; Stewart, G. R.; Albers, N.; Esposito, L. W.

2013-12-01

Theoretical studies and simulations have demonstrated the effects caused by objects embedded in planetary rings. Even if the objects are too small to be directly observed, each creates a much larger gravitational imprint on the surrounding ring material. These strongly depend on the mass of the object and range from "S" like propeller-shaped structures for about 100m-sized icy bodies to the opening of circumferential gaps as in the case of the embedded moons Pan and Daphnis and their corresponding Encke and Keeler Gaps. Since the beginning of the Cassini mission many of these smaller objects (~data from Cassini Ultraviolet Imaging Spectrograph (UVIS) and Imaging Science Subsystem (ISS) experiments. We show evidence that B ring seems to harbor two distinct populations of propellers: "big" propellers covering tens of degrees in azimuth situated in the densest part of B ring, and "small" propellers in less dense inner B ring that are similar in size and shape to known A ring propellers. The population of "big" propellers is exemplified with a single object which is observed for 5 years of Cassini data. The object is seen as a very elongated bright stripe (40 degrees wide) in unlit Cassini images, and dark stripe in lit geometries. In total we report observing the feature in images at 18 different epochs between 2005 and 2010. In UVIS occultations we observe this feature as an optical depth depletion in 14 out of 93 occultation cuts at corrotating longitudes compatible with imaging data. Combining the available Cassini data we infer that the object is a partial gap located at r=112,921km embedded in the high optical depth region of the B ring. The gap moves at Kepler speed appropriate for its radial location. Radial offsets of the gap locations in UVIS occultations are consistent with an asymmetric propeller shape. The asymmetry of the observed shape is most likely a consequence of the strong surface mass density gradient, as the feature is located at an edge between

Insulin, IGF-1, and GH Receptors Are Altered in an Adipose Tissue Depot-Specific Manner in Male Mice With Modified GH Action.

Science.gov (United States)

Hjortebjerg, Rikke; Berryman, Darlene E; Comisford, Ross; Frank, Stuart J; List, Edward O; Bjerre, Mette; Frystyk, Jan; Kopchick, John J

2017-05-01

Growth hormone (GH) is a determinant of glucose homeostasis and adipose tissue (AT) function. Using 7-month-old transgenic mice expressing the bovine growth hormone (bGH) gene and growth hormone receptor knockout (GHR-/-) mice, we examined whether changes in GH action affect glucose, insulin, and pyruvate tolerance and AT expression of proteins involved in the interrelated signaling pathways of GH, insulinlike growth factor 1 (IGF-1), and insulin. Furthermore, we searched for AT depot-specific differences in control mice. Glycated hemoglobin levels were reduced in bGH and GHR-/- mice, and bGH mice displayed impaired gluconeogenesis as judged by pyruvate tolerance testing. Serum IGF-1 was elevated by 90% in bGH mice, whereas IGF-1 and insulin were reduced by 97% and 61% in GHR-/- mice, respectively. Igf1 RNA was increased in subcutaneous, epididymal, retroperitoneal, and brown adipose tissue (BAT) depots in bGH mice (mean increase ± standard error of the mean in all five depots, 153% ± 27%) and decreased in all depots in GHR-/- mice (mean decrease, 62% ± 4%). IGF-1 receptor expression was decreased in all AT depots of bGH mice (mean decrease, 49% ± 6%) and increased in all AT depots of GHR-/- mice (mean increase, 94% ± 8%). Insulin receptor expression was reduced in retroperitoneal, mesenteric, and BAT depots in bGH mice (mean decrease in all depots, 56% ± 4%) and augmented in subcutaneous, retroperitoneal, mesenteric, and BAT depots in GHR-/- mice (mean increase: 51% ± 1%). Collectively, our findings indicate a role for GH in influencing hormone signaling in AT in a depot-dependent manner. Copyright © 2017 Endocrine Society.

Quadcopter thrust optimization with ducted-propeller

Directory of Open Access Journals (Sweden)

Kuantama Endrowednes

2017-01-01

Full Text Available In relation to quadcopter body frame model, propeller can be categorized into propeller with ducted and without ducted. This study present differences between those two using CFD (Computational Fluid Dynamics method. Both categories utilize two blade-propeller with diameter of 406 (mm. Propeller rotation generates acceleration per time unit on the volume of air. Based on the behavior of generated air velocity, ducted propeller can be modeled into three versions. The generated thrust and performance on each model were calculated to determine the best model. The use of ducted propeller increases the total weight of quadcopter and also total thrust. The influence of this modeling were analyzed in detail with variation of angular velocity propeller from 1000 (rpm to 9000 (rpm. Besides the distance between propeller tip and ducted barrier, the size of ducted is also an important part in thrust optimization and total weight minimization of quadcopter.

Cryogenics in CEBAF HMS dipole

International Nuclear Information System (INIS)

Bogensberger, P.; Ramsauer, F.; Brindza, P.; Wines, R.; Koefler, H.

1994-01-01

The paper will report upon the final design, manufacturing and tests of CEBAF's HMS Dipole cryogenic equipment. The liquid nitrogen circuits, the helium circuits and thermal insulation of the magnet will be addressed. The cryogenic reservoir and control module as an integral part of the HMS Dipole magnet will be presented. The construction, manufacturing, tests and final performance of the HMS Dipole cryogenic system will be reported. The LN 2 circuit and the He circuit are tied together by the control system for cool down, normal operation and standby. This system monitors proper temperature differences between both circuits and controls the cryogenic supply to meet the constraints. Implementation of the control features for the cryogenic system into the control system will be reported

Surface tension confined liquid cryogen cooler

International Nuclear Information System (INIS)

Castles, S.H.; Schein, M.E.

1989-01-01

A cryogenic cooler is described for use in craft such as launch, orbital and space vehicles subject to changes in orientation and conditions of vibration and weightlessness comprising: an insulated tank; a porous open celled sponge-like material disposed substantially throughout the contained volume of the insulated tank; a cryogenic fluid disposed within the sponge-like material; a cooling finger immersed in the cryogenic fluid, the finger extending from inside the insulated tank externally to an outside source such as an instrument detector for the purpose of transmitting heat from the outside source into the cryogenic fluid; means for filling the insulated tank with cryogenic fluid; and means for venting vaporized cryogenic fluid from the insulated tank

Device for delivering cryogen to rotary super-conducting winding of cryogen-cooled electrical machine

International Nuclear Information System (INIS)

Filippov, I.F.; Gorbunov, G.S.; Khutoretsky, G.M.; Popov, J.S.; Skachkov, J.V.; Vinokurov, A.A.

1980-01-01

A device is disclosed for delivering cryogen to a superconducting winding of a cryogen-cooled electrical machine comprising a pipe articulated along the axis of the electrical machine and intended to deliver cryogen. One end of said pipe is located in a rotary chamber which communicates through channels with the space of the electrical machine, and said space accommodating its superconducting winding. The said chamber accommodates a needle installed along the chamber axis, and the length of said needle is of sufficient length such that in the advanced position of said cryogen delivering pipe said needle reaches the end of the pipe. The layout of the electrical machine increases the reliability and effectiveness of the device for delivering cryogen to the superconducting winding, simplifies the design of the device and raises the efficiency of the electrical machine

Mars Ascent Vehicle-Propellant Aging

Science.gov (United States)

Dankanich, John; Rousseau, Jeremy; Williams, Jacob

2015-01-01

This project is to develop and test a new propellant formulation specifically for the Mars Ascent Vehicle (MAV) for the robotic Mars Sample Return mission. The project was initiated under the Planetary Sciences Division In-Space Propulsion Technology (ISPT) program and is continuing under the Mars Exploration Program. The two-stage, solid motor-based MAV has been the leading MAV solution for more than a decade. Additional studies show promise for alternative technologies including hybrid and bipropellant options, but the solid motor design has significant propellant density advantages well suited for physical constraints imposed while using the SkyCrane descent stage. The solid motor concept has lower specific impulse (Isp) than alternatives, but if the first stage and payload remain sufficiently small, the two-stage solid MAV represents a potential low risk approach to meet the mission needs. As the need date for the MAV slips, opportunities exist to advance technology with high on-ramp potential. The baseline propellant for the MAV is currently the carboxyl terminated polybutadiene (CTPB) based formulation TP-H-3062 due to its advantageous low temperature mechanical properties and flight heritage. However, the flight heritage is limited and outside the environments, the MAV must endure. The ISPT program competed a propellant formulation project with industry and selected ATK to develop a new propellant formulation specifically for the MAV application. Working with ATK, a large number of propellant formulations were assessed to either increase performance of a CTPB propellant or improve the low temperature mechanical properties of a hydroxyl terminated polybutadiene (HTPB) propellant. Both propellants demonstrated potential to increase performance over heritage options, but an HTPB propellant formulation, TP-H-3544, was selected for production and testing. The test plan includes propellant aging first at high vacuum conditions, representative of the Mars transit

Pengaruh Kepuasan Dan Kepercayaan Terhadap Keputusan Pembelian Ulang Pada Depot Air Minum Tris Water Reverse Osmosis System (Ro)

OpenAIRE

Fitria, Ika

2011-01-01

Kind of this survey is asociative survey which watch influence of customer satisfaction and trust to re-purchase decision on Depot Air Minum Tris Water Reverse Osmosis System (RO) and test of hypothesis use Multiple Linear Regression Analysist on α=5%. This survey used SPSS 16.00 version for windows. Research population is consumers of Depot Air Minum Tris Water Reverse Osmosis System (RO). Sample was used in this survey from customers of Depot Air Minum Tris Water Reverse Osmosis System (RO)...

Zero Gravity Cryogenic Vent System Concepts for Upper Stages

Science.gov (United States)

Ravex, Alain; Flachbart, Robin; Holt, Barney

The capability to vent in zero gravity without resettling is a technology need that involves practically all uses of sub-critical cryogenics in space. Venting without resettling would extend cryogenic orbital transfer vehicle capabilities. However, the lack of definition regarding liquid/ullage orientation coupled with the somewhat random nature of the thermal stratification and resulting pressure rise rates, lead to significant technical challenges. Typically a zero gravity vent concept, termed a thermodynamic vent system (TVS), consists of a tank mixer to destratify the propellant, combined with a Joule-Thomson (J-T) valve to extract thermal energy from the propellant. Marshall Space Flight Center's (MSFC's) Multipurpose Hydrogen Test Bed (MHTB) was used to test both spray bar and axial jet TVS concepts. The axial jet system consists of a recirculation pump heat exchanger unit. The spray bar system consists of a recirculation pump, a parallel flow concentric tube, heat exchanger, and a spray bar positioned close to the longitudinal axis of the tank. The operation of both concepts is similar. In the mixing mode, the recirculation pump withdraws liquid from the tank and sprays it into the tank liquid, ullage, and exposed tank surfaces. When energy extraction is required, a small portion of the recirculated liquid is passed sequentially through the J-T expansion valve, the heat exchanger, and is vented overboard. The vented vapor cools the circulated bulk fluid, thereby removing thermal energy and reducing tank pressure. The pump operates alone, cycling on and off, to destratify the tank liquid and ullage until the liquid vapor pressure reaches the lower set point. At that point, the J-T valve begins to cycle on and off with the pump. Thus, for short duration missions, only the mixer may operate, thus minimizing or even eliminating boil-off losses. TVS performance testing demonstrated that the spray bar was effective in providing tank pressure control within a 6

Orbital storage and supply of subcritical liquid nitrogen

Science.gov (United States)

Aydelott, John C.

1990-01-01

Subcritical cryogenic fluid management has long been recognized as an enabling technology for key propulsion applications, such as space transfer vehicles (STV) and the on-orbit cryogenic fuel depots which will provide STV servicing capability. The LeRC Cryogenic Fluids Technology Office (CFTO), under the sponsorship of OAST, has the responsibility of developing the required technology via a balanced program involving analytical modeling, ground based testing, and in-space experimentation. Topics covered in viewgraph form include: cryogenic management technologies; nitrogen storage and supply; cryogenic nitrogen cooling capability; and LN2 system demonstration technical objectives.

Cryogenic process simulation

International Nuclear Information System (INIS)

Panek, J.; Johnson, S.

1994-01-01

Combining accurate fluid property databases with a commercial equation-solving software package running on a desktop computer allows simulation of cryogenic processes without extensive computer programming. Computer simulation can be a powerful tool for process development or optimization. Most engineering simulations to date have required extensive programming skills in languages such as Fortran, Pascal, etc. Authors of simulation code have also usually been responsible for choosing and writing the particular solution algorithm. This paper describes a method of simulating cryogenic processes with a commercial software package on a desktop personal computer that does not require these traditional programming tasks. Applications include modeling of cryogenic refrigerators, heat exchangers, vapor-cooled power leads, vapor pressure thermometers, and various other engineering problems

Fundamentals of cryogenic engineering

CERN Document Server

Mukhopadhyay, Mamata

2014-01-01

The author, with her vast and varied experience in teaching and allied fields, clearly enunciates the behaviour and various properties of common cryogenic fluids, methods of liquefaction, and separation and applications of cryogens with thermodynamic analysis for process selection. This profusely illustrated study with clear-cut diagrams and process charts, should serve not only as a textbook for students but also as an excellent reference for researchers and practising engineers on design of cryogenic refrigeration, and liquefaction and separation process plants for various applications.

Cryogenics will cool LHC

International Nuclear Information System (INIS)

Anon.

2001-01-01

Results of the investigation into the cryogenic regulating line (QRL) performed by the LHC laboratory are presented. It is projected that eight cryogenic units located in five places around the LHC ring will provide superconducting magnets by liquid helium through eight cryogenic regulating lines of 3.2 km each. All QRL zones remain to be independent. CERN uses three test units with the aim of the certification of chosen constructions and verification of their thermal and mechanical efficiency before starting full-scale production [ru

HALF-DOSE DEPOT TRIPTORELIN COMPARABLE TO REDUCED DAILY BUSERELIN: A RANDOMIZED CLINICAL TRIAL

Directory of Open Access Journals (Sweden)

L. Safdarian

2007-09-01

Full Text Available Pituitary suppression by depot GnRH agonist may be excessive for ovarian stimulation. This study compares the efficacy of a single half-dose depot triptorelin and reduced-dose daily buserelin in a long protocol ICSI/ET. METHODS: A total of 182 patients were randomized into two groups using sealed envelopes. Pituitary desensitization was obtained in group 1 (91 patients with half-dose (1.87 mg depot triptorelin in the mid-luteal phase of their menstrual cycle, and in group 2 (91 patients with standard daily dose (0.5 mg buserelin, which was then reduced to 0.25 mg at the start of human menopausal gonadotropin (HMG stimulation. RESULTS: No significant differences were found among those who received HCG in terms of clinical pregnancy rate (34.4% in both groups, implantation rate (14.8% in group 1 versus 11.1% in group 2, fertilization rate (93.3 versus 95.6%, poor response rate (11.1 versus 6.7%, and miscarriage rate (11.1 versus 7.8%. No significant differences were seen in number of HMG ampoules used, follicles at HCG administration, and oocytes retrieved. The number of days of stimulation was significantly reduced in group 2 (11.2 +/- 1.8 in group 1 versus 10.6 +/- 1.9, p = 0.030. CONCLUSION: A half-dose of depot triptorelin can be successfully used in ovarian stimulation instead of reduced-dose daily buserelin, with more patient comfort and reduced stress and cost of injections.

High burn rate solid composite propellants

Science.gov (United States)

Manship, Timothy D.

High burn rate propellants help maintain high levels of thrust without requiring complex, high surface area grain geometries. Utilizing high burn rate propellants allows for simplified grain geometries that not only make production of the grains easier, but the simplified grains tend to have better mechanical strength, which is important in missiles undergoing high-g accelerations. Additionally, high burn rate propellants allow for a higher volumetric loading which reduces the overall missile's size and weight. The purpose of this study is to present methods of achieving a high burn rate propellant and to develop a composite propellant formulation that burns at 1.5 inches per second at 1000 psia. In this study, several means of achieving a high burn rate propellant were presented. In addition, several candidate approaches were evaluated using the Kepner-Tregoe method with hydroxyl terminated polybutadiene (HTPB)-based propellants using burn rate modifiers and dicyclopentadiene (DCPD)-based propellants being selected for further evaluation. Propellants with varying levels of nano-aluminum, nano-iron oxide, FeBTA, and overall solids loading were produced using the HTPB binder and evaluated in order to determine the effect the various ingredients have on the burn rate and to find a formulation that provides the burn rate desired. Experiments were conducted to compare the burn rates of propellants using the binders HTPB and DCPD. The DCPD formulation matched that of the baseline HTPB mix. Finally, GAP-plasticized DCPD gumstock dogbones were attempted to be made for mechanical evaluation. Results from the study show that nano-additives have a substantial effect on propellant burn rate with nano-iron oxide having the largest influence. Of the formulations tested, the highest burn rate was a 84% solids loading mix using nano-aluminum nano-iron oxide, and ammonium perchlorate in a 3:1(20 micron: 200 micron) ratio which achieved a burn rate of 1.2 inches per second at 1000

Cryogenics

International Nuclear Information System (INIS)

Gutierrez R, C.; Jimenez D, J.; Cejudo A, J.; Hernandez M, V.

1997-01-01

Cryogenics is one of these technologies which contributes to scientific research that supports to the industry in the following benefits: 1. Storage ability and a great quantity of dense gases with cryogenic liquid which is found at high pressure. 2. Production ability at low cost with high purity gases through distillation or condensation. 3. Ability to use low temperatures in the refrigerating materials or alteration of the physical properties. This technology is used for reprocessing of those short and long half life radioactive wastes which always have been required that to be separated with classical methods. In this text we report the radioactive wastes separation by more sophisticated methods but more quickly and reliable. (Author)

Whole tree transportation system for timber processing depots

Science.gov (United States)

John Lancaster; Tom Gallagher; Tim  McDonald; Dana Mitchell

2016-01-01

The growing demand for alternative energy has led those who are interested in producing sustainable energy from renewable timber to devise new concepts to satisfy those demands. The concept of timber processing depots, where whole stem trees will be delivered for future processing into wood products and high quality energy fuel, has led to the re-evaluation of our...

TPC magnet cryogenic system

International Nuclear Information System (INIS)

Green, M.A.; Burns, W.A.; Taylor, J.D.; Van Slyke, H.W.

1980-03-01

The Time Projection Chamber (TPC) magnet at LBL and its compensation solenoids are adiabatically stable superconducting solenoid magnets. The cryogenic system developed for the TPC magnet is discussed. This system uses forced two-phase tubular cooling with the two cryogens in the system. The liquid helium and liquid nitrogen are delivered through the cooled load by forced tubular flow. The only reservoirs of liquid cryogen exist in the control dewar (for liquid helium) and the conditioner dewar (for liquid nitrogen). The operation o these systems during virtually all phases of system operation are described. Photographs and diagrams of various system components are shown, and cryogenic system data are presented in the following sections: (1) heat leaks into the TPC coil package and the compensation solenoids; (2) heat leaks to various components of the TPC magnet cryogenics system besides the magnets and control dewar; (3) the control dewar and its relationship to the rest of the system; (4) the conditioner system and its role in cooling down the TPC magnet; (5) gas-cooled electrical leads and charging losses; and (6) a summation of the liquid helium and liquid nitrogen requirements for the TPC superconducting magnet system

An Overview of Recent Cryogenic Fluid Management Developments

Science.gov (United States)

Hedayat, A.; Johnson, W. L.; Stephens, J. R.

2017-01-01

(GRC, MSFC, JSC, and KSC) collaborated to investigate multiple different hardware combinations, refrigeration cycles, and integration techniques to minimize power and mass of the storage and liquefaction system. Moreover, high efficiency, high capacity cryocoolers are an element of CFM which is essential for achieving NASA's future long duration missions. Currently in development is a 20W at 20K unit for use with liquid hydrogen. It is scheduled for delivery to NASA in the summer of 2017. Two Phase I SBIRS have recently concluded resulting in the preliminary design of two different 90K units, each having a refrigeration capacity of approximately 150W. Once the development efforts are complete, these high capacity 90K units will be integrated into the design of NASA's Liquid Oxygen (LOX)/Methane applications such as the Lander and Ascent Vehicles, or possibly an in-space stage. CFM technology is critical to the success of missions to Mars, Planetary Exploration, and In-Situ Resource Utilization (ISRU) for cryogenic propellant production. NASA is focusing on the development of CFM technologies needed to provide necessary data and relevant experience to support informed decisions on implementation of design of cryogenic systems for long term space missions. Lessons learned from the described CFM developments would lead to enhanced safety and reliability and enabling technologies which could allow NASA to meet future space exploration goals.

CEBAF cryogenic system

International Nuclear Information System (INIS)

1995-01-01

The CEBAF cryogenic system consists of 3 refrigeration systems: Cryogenic Test Facility (CTF), Central Helium Liquefier (CHL), and End Station Refrigerator (ESR). CHL is the main cryogenic system for CEBAF, consisting of a 4.8 kW, 2.0 K refrigerator and transfer line system to supply 2.0 K and 12 kW of 50 K shield refrigeration for the Linac cavity cryostats and 10 g/s of liquid for the end stations. This paper describes the 9-year effort to commission these systems, concentrating on CHL with the cold compressors. The cold compressors are a cold vacuum pump with an inlet temperature of 3 K which use magnetic bearings, thereby eliminating the possibility of air leaks into the subatmospheric He

MOSFET's for Cryogenic Amplifiers

Science.gov (United States)

Dehaye, R.; Ventrice, C. A.

1987-01-01

Study seeks ways to build transistors that function effectively at liquid-helium temperatures. Report discusses physics of metaloxide/semiconductor field-effect transistors (MOSFET's) and performances of these devices at cryogenic temperatures. MOSFET's useful in highly sensitive cryogenic preamplifiers for infrared astronomy.

AUTOMATED DETECTION OF OIL DEPOTS FROM HIGH RESOLUTION IMAGES: A NEW PERSPECTIVE

Directory of Open Access Journals (Sweden)

A. O. Ok

2015-03-01

Full Text Available This paper presents an original approach to identify oil depots from single high resolution aerial/satellite images in an automated manner. The new approach considers the symmetric nature of circular oil depots, and it computes the radial symmetry in a unique way. An automated thresholding method to focus on circular regions and a new measure to verify circles are proposed. Experiments are performed on six GeoEye-1 test images. Besides, we perform tests on 16 Google Earth images of an industrial test site acquired in a time series manner (between the years 1995 and 2012. The results reveal that our approach is capable of detecting circle objects in very different/difficult images. We computed an overall performance of 95.8% for the GeoEye-1 dataset. The time series investigation reveals that our approach is robust enough to locate oil depots in industrial environments under varying illumination and environmental conditions. The overall performance is computed as 89.4% for the Google Earth dataset, and this result secures the success of our approach compared to a state-of-the-art approach.

CRYOGENIC AND VACUUM TECHNOLOGICAL ASPECTS OF THE LOW-ENERGY ELECTROSTATIC CRYOGENIC STORAGE RING

International Nuclear Information System (INIS)

Orlov, D. A.; Lange, M.; Froese, M.; Hahn, R. von; Grieser, M.; Mallinger, V.; Sieber, T.; Weber, T.; Wolf, A.; Rappaport, M.

2008-01-01

The cryogenic and vacuum concepts for the electrostatic Cryogenic ion Storage Ring (CSR), under construction at the Max-Planck-Institut fuer Kernphysik in Heidelberg, is presented. The ring will operate in a broad temperature range from 2 to 300 K and is required to be bakeable up to 600 K. Extremely high vacuum and low temperatures are necessary to achieve long lifetimes of the molecular ions stored in the ring so that the ions will have enough time to cool by radiation to their vibrational and rotational ground states. To test cryogenic and vacuum technological aspects of the CSR, a prototype is being built and will be connected to the commercial cryogenic refrigerator recently installed, including a specialized 2-K connection system. The first results and the status of current work with the prototype are also presented

Analytical Solution and Physics of a Propellant Damping Device

Science.gov (United States)

Yang, H. Q.; Peugeot, John

2011-01-01

NASA design teams have been investigating options for "detuning" Ares I to prevent oscillations originating in the vehicle solid-rocket main stage from synching up with the natural resonance of the rest of the vehicle. An experimental work started at NASA MSFC center in 2008 using a damping device showed great promise in damping the vibration level of an 8 resonant tank. However, the mechanisms of the vibration damping were not well understood and there were many unknowns such as the physics, scalability, technology readiness level (TRL), and applicability for the Ares I vehicle. The objectives of this study are to understand the physics of intriguing slosh damping observed in the experiments, to further validate a Computational Fluid Dynamics (CFD) software in propellant sloshing against experiments with water, and to study the applicability and efficiency of the slosh damper to a full scale propellant tank and to cryogenic fluids. First a 2D fluid-structure interaction model is built to model the system resonance of liquid sloshing and structure vibration. A damper is then added into the above model to simulate experimentally observed system damping phenomena. Qualitative agreement is found. An analytical solution is then derived from the Newtonian dynamics for the thrust oscillation damper frequency, and a slave mass concept is introduced in deriving the damper and tank interaction dynamics. The paper will elucidate the fundamental physics behind the LOX damper success from the derivation of the above analytical equation of the lumped Newtonian dynamics. Discussion of simulation results using high fidelity multi-phase, multi-physics, fully coupled CFD structure interaction model will show why the LOX damper is unique and superior compared to other proposed mitigation techniques.

Advances in Cryogenic Principles

Science.gov (United States)

Barron, R. F.

During the past 50 years, the use of digital computers has significantly influenced the design and analysis of cryogenic systems. At the time when the first Cryogenic Engineering Conference was held, thermodynamic data were presented in graphical or tabular form (the "steam table" format), whereas thermodynamic data for cryogenic system design is computer generated today. The thermal analysis of cryogenic systems in the 1950s involved analytical solutions, graphical solutions, and relatively simple finite-difference approaches. These approaches have been supplanted by finite-element numerical programs which readily solve complicated thermal problems that could not be solved easily using the methods of the 1950s. In distillation column design, the use of the McCabe-Thiele graphical method for determination of the number of theoretical plates has been replaced by numerical methods that allow consideration of several different components in the feed and product streams.

Cryogenic systems for detectors and particle accelerators

International Nuclear Information System (INIS)

Sondericker, J.H.

1988-01-01

It's been one hundred years since the first successful experiments were carried out leading to the liquefaction of oxygen which birthed the field of cryogenics and about sixty years since cryogenics went commercial. Originally, cryogenics referred to the technology and art of producing low temperatures but today the definition adopted by the XII Congress of the International Institute of Refrigeration describes cryogenics as the study of phenomena, techniques, and concepts occurring at our pertaining to temperatures below 120 K. Modern acceptance of the importance and use of cryogenic fluids continues to grow. By far, the bulk of cryogenic products are utilized by industry for metal making, agriculture, medicine, food processing and as efficient storage of fuels. Cryogenics has found many uses in the scientific community as well, enabling the development of ultra low noise amplifiers, fast cold electronics, cryopumped ultra high vacuums, the production of intense magnetic fields and low loss power transmission through the sue of cryogenically cooled superconductors. High energy physic research has been and continues to use cryogenic hardware to produce liquids used as detector targets and to produce refrigeration necessary to cool superconducting magnets to design temperature for particle accelerator applications. In fact, today's super accelerators achieve energies that would be impossible to reach with conventional copper magnets, demonstrating that cryogenics has become an indispensable ingredient in today's scientific endeavors

Examining a Paradigm Shift in Organic Depot-Level Software Maintenance for Army Communications and Electronics Equipment

Science.gov (United States)

2015-05-30

scalable application of cutting edge technologies. 20 4. Responding to changing resources—With likely significant resource reductions the depot...deal with underutilized organic capability while continuing to increase outsourcing of depot workload. In addition the study states that a...the unique organic skills that TYAD could 40 bring to the software sustainment mission could be valuable based on the specific type of software

Clay Nanoparticles Elicit Long-Term Immune Responses by Forming Biodegradable Depots for Sustained Antigen Stimulation.

Science.gov (United States)

Chen, Weiyu; Zuo, Huali; Li, Bei; Duan, Chengcheng; Rolfe, Barbara; Zhang, Bing; Mahony, Timothy J; Xu, Zhi Ping

2018-05-01

Nanomaterials have been widely tested as new generation vaccine adjuvants, but few evoke efficient immunoreactions. Clay nanoparticles, for example, layered double hydroxide (LDH) and hectorite (HEC) nanoparticles, have shown their potent adjuvanticity in generating effective and durable immune responses. However, the mechanism by which clay nanoadjuvants stimulate the immune system is not well understood. Here, it is demonstrated that LDH and HEC-antigen complexes form loose agglomerates in culture medium/serum. They also form nodules with loose structures in tissue after subcutaneous injection, where they act as a depot for up to 35 d. More importantly, clay nanoparticles actively and continuously recruit immune cells into the depot for up to one month, and stimulate stronger immune responses than FDA-approved adjuvants, Alum and QuilA. Sustained antigen release is also observed in clay nanoparticle depots, with 50-60% antigen released after 35 d. In contrast, Alum-antigen complexes show minimal antigen release from the depot. Importantly, LDH and HEC are more effective than QuilA and Alum in promoting memory T-cell proliferation. These findings suggest that both clay nanoadjuvants can serve as active vaccine platforms for sustained and potent immune responses. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Cryogenics in nuclear reactor technology

International Nuclear Information System (INIS)

Dharmadurai, G.

1982-01-01

The cryogenic technology has significantly contributed to the development of several proven techniques for use in the nuclear power industry. A noteworthy feature is the unique role of cryogenics in minimising the release of radioactive and some chemical pollutants to the environment during the operation of various plants associated with this industry. The salient technological features of several cryogenic processes relevant to the nuclear reactor technology are discussed. (author)

Surface Tension Confines Cryogenic Liquid

Science.gov (United States)

Castles, Stephen H.; Schein, Michael E.

1989-01-01

New type of Dewar provides passive, constant-temperature cryogenic cooling for scientific instruments under normal-to low-gravity conditions. Known as Surface-Tension-Contained Liquid Cryogen Cooler (STCLCC), keeps liquid cryogen in known location inside the Dewar by trapping liquid inside spongelike material. Unique sponge material fills most of volume of inner tank. Sponge is all-silica, open-cell material similar to that used for Space Shuttle thermal-protection tiles.

Polymers at cryogenic temperatures

CERN Document Server

Fu, Shao-Yun

2013-01-01

Kalia and Fu's novel monograph covers cryogenic treatment, properties and applications of cryo-treated polymer materials. Written by numerous international experts, the twelve chapters in this book offer the reader a comprehensive picture of the latest findings and developments, as well as an outlook on the field. Cryogenic technology has seen remarkable progress in the past few years and especially cryogenic properties of polymers are attracting attention through new breakthroughs in space, superconducting, magnetic and electronic techniques. This book is a valuable resource for researchers, educators, engineers and graduate students in the field and at technical institutions.

FRIB Cryogenic Plant Status

Energy Technology Data Exchange (ETDEWEB)

Dixon, Kelly D. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Ganni, Venkatarao [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Knudsen, Peter N. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Casagranda, Fabio [Michigan State Univ., East Lansing, MI (United States)

2015-12-01

After practical changes were approved to the initial conceptual design of the cryogenic system for MSU FRIB and an agreement was made with JLab in 2012 to lead the design effort of the cryogenic plant, many activities are in place leading toward a cool-down of the linacs prior to 2018. This is mostly due to using similar equipment used at CHLII for the 12 GeV upgrade at JLab and an aggressive schedule maintained by the MSU Conventional Facilities department. Reported here is an updated status of the cryogenic plant, including the equipment procurement status, plant layout, facility equipment and project schedule.

Academic Training: Introduction to cryogenic Engineering

CERN Multimedia

Françoise Benz

2005-01-01

2005-2006 ACADEMIC TRAINING PROGRAMME LECTURE SERIES 5, 6, 7, 8 and 9 December from 11:00 to 12:00 - Main Auditorium, bldg. 500 Introduction to cryogenic Engineering by G. Perinic - CERN-AT Cryogenic engineering is one of the key technologies at CERN. It is widely used in research and has many applications in industry and last but not least in medicine. In research cryogenic engineering and its applications are omnipresent from the smallest laboratories to fusion reactors, huge detectors and accelerators. With the termination of the LHC, CERN will in fact become the world’s largest cryogenic installation. This series of talks intends to introduce the non-cryogenist to the basic principles and challenges of cryogenic engineering and its applications. The course will also provide a basis for practical application as well as for further learning. Monday 5.12.2005 Introduction: From History to Modern Refrigeration Cycles (Goran Perinic) Tuesday 6.12.2005 Refrigerants, Standard Cryostats, Cryogenic Des...

Academic Training: Introduction to cryogenic Engineering

CERN Multimedia

Françoise Benz

2005-01-01

2005-2006 ACADEMIC TRAINING PROGRAMME LECTURE SERIES 5, 6, 7, 8 and 9 December from 11:00 to 12:00 - Main Auditorium, bldg. 500 Introduction to cryogenic Engineering by G. Perinic - CERN-AT Cryogenic engineering is one of the key technologies at CERN. It is widely used in research and has many applications in industry and last but not least in medicine. In research cryogenic engineering and its applications are omnipresent from the smallest laboratories to fusion reactors, hughe detectors and accelerators. With the termination of the LHC, CERN will in fact become the world's largest cryogenic installation. This series of talks intends to introduce the non-cryogenist to the basic principles and challenges of cryogenic engineering and its applications. The course will also provide a basis for practical application as well as for further learning. From history to modern refrigeration cycles (1/5) Refrigerants, standard cryostats, cryogenic design (2/5) Heat transfer and insulation (3/5) Safety in cryoge...

Development of HAN-based Liquid Propellant Thruster

Science.gov (United States)

Hisatsune, K.; Izumi, J.; Tsutaya, H.; Furukawa, K.

2004-10-01

Many of propellants that are applied to the conventional spacecraft propulsion system are toxic propellants. Because of its toxicity, considering the environmental pollution or safety on handling, it will be necessary to apply the "green" propellant to the spacecraft propulsion system. The purpose of this study is to apply HAN based liquid propellant (LP1846) to mono propellant thruster. Compared to the hydrazine that is used in conventional mono propellant thruster, HAN based propellant is not only lower toxic but also can obtain higher specific impulse. Moreover, HAN based propellant can be decomposed by the catalyst. It means there are the possibility of applying to the mono propellant thruster that can leads to the high reliability of the propulsion system.[1],[2] However, there are two technical subjects, to apply HAN based propellant to the mono propellant thruster. One is the high combustion temperature. The catalyst will be damaged under high temperature condition. The other is the low catalytic activity. It is the serious problem on application of HAN based propellant to the mono propellant thruster that is used for attitude control of spacecraft. To improve the catalytic activity of HAN based propellant, it is necessary to screen the best catalyst for HAN based propellant. The adsorption analysis is conducted by Monte Carlo Simulation to screen the catalyst metal for HAN and TEAN. The result of analysis shows the Iridium is the best catalyst metal for HAN and TEAN. Iridium is the catalyst metal that is used at conventional mono propellant thruster catalyst Shell405. Then, to confirm the result of analysis, the reaction test about catalyst is conducted. The result of this test is the same as the result of adsorption analysis. That means the adsorption analysis is effective in screening the catalyst metal. At the evaluating test, the various types of carrier of catalyst are also compared to Shell 405 to improve catalytic activity. The test result shows the

14 CFR 35.23 - Propeller control system.

Science.gov (United States)

2010-01-01

... propeller effect under the intended operating conditions. (4) The failure or corruption of data or signals... corruption of airplane-supplied data does not result in hazardous propeller effects. (e) The propeller... effect. (2) Failures or malfunctions directly affecting the propeller control system in a typical...

Cryogenics for LHC experiments

CERN Multimedia

2001-01-01

Cryogenic systems will be used by LHC experiments to maximize their performance. Institutes around the world are collaborating with CERN in the construction of these very low temperature systems. The cryogenic test facility in hall 180 for ATLAS magnets. High Energy Physics experiments have frequently adopted cryogenic versions of their apparatus to achieve optimal performance, and those for the LHC will be no exception. The two largest experiments for CERN's new flagship accelerator, ATLAS and CMS, will both use large superconducting magnets operated at 4.5 Kelvin - almost 270 degrees below the freezing point of water. ATLAS also includes calorimeters filled with liquid argon at 87 Kelvin. For the magnets, the choice of a cryogenic version was dictated by a combination economy and transparency to emerging particles. For the calorimeters, liquid argon was selected as the fluid best suited to the experiment's physics requirements. High Energy Physics experiments are the result of worldwide collaborations and...

Financial incentives for antipsychotic depot medication: ethical issues.

Science.gov (United States)

Claassen, Dirk

2007-04-01

Giving money as a direct incentive for patients in exchange for depot medication has proved beneficial in some clinical cases in assertive outreach (AO). However, ethical concerns around this practice have been raised, and will be analysed in more detail here. Ethical concern voiced in a survey of all AO teams in England were analysed regarding their content. These were grouped into categories. 53 of 70 team managers mentioned concerns, many of them serious and expressing a negative attitude towards giving money for depot adherence. Four broad categories of ethical concern following Christensen's concept were distinguished: valid consent and refusal (n = 5), psychiatric paternalism (n = 31), resource allocation (n = 4), organisational relationships (n = 2), with a residual category others and unspecified (n = 11). The main concerns identified are discussed on the background of existing ethical theories in healthcare and the specific problems of community mental health and AO. Points for practice are derived from this discussion. A way forward is outlined that includes informed consent and an operational policy in the use of incentives, further randomised controlled trials and qualitative studies, and continuing discussions with all stakeholders, especially service users.

Master Environmental Plan: Fort Wingate Depot Activity, Gallup, New Mexico

Energy Technology Data Exchange (ETDEWEB)

Biang, C.A.; Yuen, C.R.; Biang, R.P.; Antonopoulos, A.A.; Ditmars, J.D.

1990-12-01

The master environmental plan is based on an environmental assessment of the areas requiring environmental evaluation (AREEs) at Fort Wingate Depot Activity near Gallup, New Mexico. The Fort Wingate Depot Activity is slated for closure under the Base Closure and Realignment Act, Public Law 100--526. The MEP assesses the current status, describes additional data requirements, recommends actions for the sites, and establishes a priority order for actions. The plan was developed so that actions comply with hazardous waste and water quality regulations of the State of New Mexico and applicable federal regulations. It contains a brief history of the site, relevant geological and hydrological information, and a description of the current status for each AREE along with a discussion of the available site-specific data that pertain to existing or potential contamination and the impact on the environment. 35 refs., 27 figs., 23 tabs.

Hydrodynamics of Ship Propellers

DEFF Research Database (Denmark)

Breslin, John P.; Andersen, Poul

This book deals with flows over propellers operating behind ships, and the hydrodynamic forces and moments which the propeller generates on the shaft and on the ship hull.The first part of the text is devoted to fundamentals of the flow about hydrofoil sections (with and without cavitation...... of an intermittently cavitating propeller in a wake and the pressures and forces it exerts on the shaft and on the ship hull is examined. A final chapter discusses the optimization of efficiency of compound propulsors. The authors have taken care to clearly describe physical concepts and mathematical steps. Appendices...

Cryogenic storage tank with built-in pump

International Nuclear Information System (INIS)

Zwick, E.B.

1984-01-01

A cryogenic storage tank with a built-in pump for pumping cryogen directly from the primary storage container consistent with low boil-off losses of cryogen has an outer vessel, an inner vessel and an evacuated insulation space therebetween. A pump mounting tube assembly extends into the interior of the inner vessel and includes an inner pump mounting tube and an outer pump mounting tube joined at their lower rims to define an insulating jacket between the two tubes. The inner pump mounting tube is affixed at its upper end to the outer vessel while the outer pump mounting tube is affixed at its upper end to the inner vessel. The inner pump mounting tube defines a relatively long heat path into the cryogenic container and is itself insulated from the liquid cryogen by a pocket of trapped gas formed within the inner pump mounting tube by heated cryogen. A pump may be introduced through the inner pump mounting tube and is also insulated against contact with liquid cryogen by the trapped gas such that only the lowermost end of the pump is immersed in cryogen thereby minimizing heat leakage into the tank

Intrinsic differences in adipocyte precursor cells from different white fat depots

DEFF Research Database (Denmark)

Macotela, Yazmín; Emanuelli, Brice; Mori, Marcelo A

2012-01-01

Obesity and body fat distribution are important risk factors for the development of type 2 diabetes and metabolic syndrome. Evidence has accumulated that this risk is related to intrinsic differences in behavior of adipocytes in different fat depots. In the current study, we demonstrate...... that adipocyte precursor cells (APCs) isolated from visceral and subcutaneous white adipose depots of mice have distinct patterns of gene expression, differentiation potential, and response to environmental and genetic influences. APCs derived from subcutaneous fat differentiate well in the presence of classical...... induction cocktail, whereas those from visceral fat differentiate poorly but can be induced to differentiate by addition of bone morphogenetic protein (BMP)-2 or BMP-4. This difference correlates with major differences in gene expression signature between subcutaneous and visceral APCs. The number of APCs...

Solid propellant impact tests

International Nuclear Information System (INIS)

Snow, E.C.

1976-03-01

Future space missions, as in the past, call for the continued use of radioisotopes as heat sources for thermoelectric power generators. In an effort to minimize the risk of radioactive contamination of the environment, a complete safety analysis of each such system is necessary. As a part of these analyses, the effects on such a system of a solid propellant fire environment resulting from a catastrophic launch pad abort must be considered. Several impact tests were conducted in which either a simulant MHW-FSA or a steel ball was dropped on the cold, unignited or the hot, burning surface of a block of UTP-3001 solid propellant. The rebound velocities were measured for both surface conditions of the propellant. The resulting coefficient of restitution, determined as the ratio of the components of the impact and rebound velocities perpendicular to the impact surface of the propellant, were not very dependent on whether the surface was cold or hot at the time of impact

Propeller and inflow vortex interaction : vortex response and impact on the propeller performance

NARCIS (Netherlands)

Yang, Y.; Zhou, T; Sciacchitano, A.; Veldhuis, L.L.M.; Eitelberg, G.

2016-01-01

The aerodynamic operating conditions of a propeller can include complex situations where vorticity from sources upstream can enter the propeller plane. In general, when the vorticity enters in a concentrated form of a vortex, the interaction between the vortex and blade is referred to as

Cryogen therapy of skin cancer

International Nuclear Information System (INIS)

Zikiryakhodjaev, D.Z.; Sanginov, D.R.

2001-01-01

In this chapter authors studied the cure of skin cancer in particular cryogen therapy of skin cancer. They noted that cryogen therapy of skin cancer carried new possibilities and improved results of neoplasms treatment

The Cryogenic Test Bed experiments: Cryogenic heat pipe flight experiment CRYOHP (STS-53). Cryogenic two phase flight experiment CRYOTP (STS-62). Cryogenic flexible diode flight experiment CRYOFD

Science.gov (United States)

Thienel, Lee; Stouffer, Chuck

1995-09-01

This paper presents an overview of the Cryogenic Test Bed (CTB) experiments including experiment results, integration techniques used, and lessons learned during integration, test and flight phases of the Cryogenic Heat Pipe Flight Experiment (STS-53) and the Cryogenic Two Phase Flight Experiment (OAST-2, STS-62). We will also discuss the Cryogenic Flexible Diode Heat Pipe (CRYOFD) experiment which will fly in the 1996/97 time frame and the fourth flight of the CTB which will fly in the 1997/98 time frame. The two missions tested two oxygen axially grooved heat pipes, a nitrogen fibrous wick heat pipe and a 2-methylpentane phase change material thermal storage unit. Techniques were found for solving problems with vibration from the cryo-collers transmitted through the compressors and the cold heads, and mounting the heat pipe without introducing parasitic heat leaks. A thermally conductive interface material was selected that would meet the requirements and perform over the temperature range of 55 to 300 K. Problems are discussed with the bi-metallic thermostats used for heater circuit protection and the S-Glass suspension straps originally used to secure the BETSU PCM in the CRYOTP mission. Flight results will be compared to 1-g test results and differences will be discussed.

Deployment Strategy for Car-Sharing Depots by Clustering Urban Traffic Big Data Based on Affinity Propagation

Directory of Open Access Journals (Sweden)

Zhihan Liu

2018-01-01

Full Text Available Car sharing is a type of car rental service, by which consumers rent cars for short periods of time, often charged by hours. The analysis of urban traffic big data is full of importance and significance to determine locations of depots for car-sharing system. Taxi OD (Origin-Destination is a typical dataset of urban traffic. The volume of the data is extremely large so that traditional data processing applications do not work well. In this paper, an optimization method to determine the depot locations by clustering taxi OD points with AP (Affinity Propagation clustering algorithm has been presented. By analyzing the characteristics of AP clustering algorithm, AP clustering has been optimized hierarchically based on administrative region segmentation. Considering sparse similarity matrix of taxi OD points, the input parameters of AP clustering have been adapted. In the case study, we choose the OD pairs information from Beijing’s taxi GPS trajectory data. The number and locations of depots are determined by clustering the OD points based on the optimization AP clustering. We describe experimental results of our approach and compare it with standard K-means method using quantitative and stationarity index. Experiments on the real datasets show that the proposed method for determining car-sharing depots has a superior performance.

Heat switch technology for cryogenic thermal management

Science.gov (United States)

Shu, Q. S.; Demko, J. A.; E Fesmire, J.

2017-12-01

Systematic review is given of development of novel heat switches at cryogenic temperatures that alternatively provide high thermal connection or ideal thermal isolation to the cold mass. These cryogenic heat switches are widely applied in a variety of unique superconducting systems and critical space applications. The following types of heat switch devices are discussed: 1) magnetic levitation suspension, 2) shape memory alloys, 3) differential thermal expansion, 4) helium or hydrogen gap-gap, 5) superconducting, 6) piezoelectric, 7) cryogenic diode, 8) magneto-resistive, and 9) mechanical demountable connections. Advantages and limitations of different cryogenic heat switches are examined along with the outlook for future thermal management solutions in materials and cryogenic designs.

Radiological Final Status Survey of the Hammond Depot, Hammond, Indiana

International Nuclear Information System (INIS)

Vitkus, T.J.

2008-01-01

ORISE conducted extensive scoping, characterization, and final status surveys of land areas and structures at the DNSC's Hammond Depot located in Hammond, Indiana in multiple phases during 2005, 2006 and 2007. This report provides a detailed discussion of the radiological survey planning, survey implementation, remediation, and the results for these activities supporting the conclusion that radioactive contamination previously identified at the Hammond Depot (HD) has been reduced to levels such that the site may be released without radiological restrictions. The objective of the radiological final status survey (FSS) was to obtain the data necessary to demonstrate compliance with the U.S. Nuclear Regulatory Commission (NRC)-approved site-specific derived concentration guideline levels (DCGLs) for both structural surfaces and outdoor areas (ORISE 2006a and NRC 2007). The DCGLs were modeled such that any residual licensed material would not exceed the NRC's basic dose limit for license termination of 25 millirem per year (mrem/y)

Elucidation of molecular mechanisms of physiological variations between bovine subcutaneous and visceral fat depots under different nutritional regimes.

Science.gov (United States)

Romao, Josue Moura; Jin, Weiwu; He, Maolong; McAllister, Tim; Guan, Le Luo

2013-01-01

Adipose tissue plays a critical role in energy homeostasis and metabolism. There is sparse understanding of the molecular regulation at the protein level of bovine adipose tissues, especially within different fat depots under different nutritional regimes. The objective of this study was to analyze the differences in protein expression between bovine subcutaneous and visceral fat depots in steers fed different diets and to identify the potential regulatory molecular mechanisms of protein expression. Subcutaneous and visceral fat tissues were collected from 16 British-continental steers (15.5 month old) fed a high-fat diet (7.1% fat, n=8) or a control diet (2.7% fat, n=8). Protein expression was profiled using label free quantification LC-MS/MS and expression of selected transcripts was evaluated using qRT-PCR. A total of 682 proteins were characterized and quantified with fat depot having more impact on protein expression, altering the level of 51.0% of the detected proteins, whereas diet affected only 5.3%. Functional analysis revealed that energy production and lipid metabolism were among the main functions associated with differentially expressed proteins between fat depots, with visceral fat being more metabolically active than subcutaneous fat as proteins associated with lipid and energy metabolism were upregulated. The expression of several proteins was significantly correlated to subcutaneous fat thickness and adipocyte size, indicating their potential as adiposity markers. A poor correlation (r=0.245) was observed between mRNA and protein levels for 9 genes, indicating that many proteins may be subjected to post-transcriptional regulation. A total of 8 miRNAs were predicted to regulate more than 20% of lipid metabolism proteins differentially expressed between fat depots, suggesting that miRNAs play a role in adipose tissue regulation. Our results show that proteomic changes support the distinct metabolic and physiological characteristics observed between

Obesity associated disease risk: the role of inherent differences and location of adipose depots.

Science.gov (United States)

Hill, Jessica H; Solt, Claudia; Foster, Michelle T

2018-03-16

Obesity and associated metabolic co-morbidities are a worldwide public health problem. Negative health outcomes associated with obesity, however, do not arise from excessive adiposity alone. Rather, deleterious outcomes of adipose tissue accumulation are a result of how adipocytes are distributed to individual regions in the body. Due to our increased understanding of the dynamic relationship that exists between specific adipose depots and disease risk, an accurate characterization of total body adiposity as well as location is required to properly evaluate a population's disease risk. Specifically, distinctive tissue depots within the body include the lower body, upper body and abdominal (deep and superficial) subcutaneous regions, as well as visceral (mesenteric and omental) regions. Upper body and visceral adipose tissues are highly associated with metabolic dysfunction and chronic disease development, whereas lower body gluteofemoral subcutaneous adipose tissue imparts protection against diet-induced metabolic derangement. Each adipose depot functions distinctly as an endocrine organ hence it has a different level of impact on health outcomes. Effluent from adipose tissue can modulate the functions of other tissues, whilst receiving differential communication from the rest of the body via central nervous system innervation, metabolites and other signaling molecules. More so, adipose depots contain a diverse reservoir of tissue-resident immune cells that play an integral part in both maintaining tissue homeostasis, as well as propagating metabolically-induced inflammation. Overall, the conceptualization of obesity and associated risks needs updating to reflect the complexities of obesity. We review adipose tissue characteristics that are linked to deleterious or beneficial adipose tissue distributions.

Cavitation simulation on marine propellers

DEFF Research Database (Denmark)

Shin, Keun Woo

Cavitation on marine propellers causes thrust breakdown, noise, vibration and erosion. The increasing demand for high-efficiency propellers makes it difficult to avoid the occurrence of cavitation. Currently, practical analysis of propeller cavitation depends on cavitation tunnel test, empirical...... criteria and inviscid flow method, but a series of model test is costly and the other two methods have low accuracy. Nowadays, computational fluid dynamics by using a viscous flow solver is common for practical industrial applications in many disciplines. Cavitation models in viscous flow solvers have been...... hydrofoils and conventional/highly-skewed propellers are performed with one of three cavitation models proven in 2D analysis. 3D cases also show accuracy and robustness of numerical method in simulating steady and unsteady sheet cavitation on complicated geometries. Hydrodynamic characteristics of cavitation...

Testing of a Spray-Bar Zero Gravity Cryogenic Vent System for Upper Stages

Science.gov (United States)

Lak, Tibor; Flachbart, Robin; Nguyen, Han; Martin, James

1999-01-01

The capability to vent in zero gravity without resettling is a fundamental technology need that involves practically all uses of subcritical cryogenics in space. Venting without resettling would extend cryogenic orbital transfer vehicle capabilities. However, the lack of definition regarding liquid/ullage orientation coupled with the somewhat random nature of the thermal stratification and resulting pressure rise rates, lead to significant technical challenges. Typically a zero gravity vent concept, termed a thermodynamic vent system (TVS), consists of a tank mixer to destratify the propellant, combined with a Joule- Thomson (J-T) valve to extract then-nal energy from the propellant. In a cooperative effort, Marshall Space Flight Center's (MSFC's) Multipurpose Hydrogen Test Bed (N4HTB) was used to test a unique "spray bar" TVS system developed by Boeing. A schematic of this system is included in Figure 1. The system consists of a recirculation pump, a parallel flow concentric tube, heat exchanger, and a spray bar positioned close to the longitudinal axis of the tank. In the mixing mode, the recirculation pump withdraws liquid from the tank and sprays it radially into the tank liquid, ullage, and exposed tank surfaces. When energy extraction is required, a small portion of the recirculated liquid is passed sequentially through the J-T expansion valve, the spray bar heat exchanger element, and is vented overboard. The vented vapor cools the circulated bulk fluid, thereby removing thermal energy and reducing tank pressure. Figure 2 is a plot of ullage pressure (P4) and liquid vapor pressure (PSAI) versus time. The pump operates alone, cycling on and off, to destratify the tank liquid and ullage until the liquid vapor pressure reaches the lower set point. At that point, the J-T valve begins to cycle on and off with the pump. Thus, for short duration missions, only the mixer may operate, thus minimizing or even eliminating boil-off losses. The primary advantage of the

Control of Adipocyte Differentiation in Different Fat Depots; Implications for Pathophysiology or Therapy

Directory of Open Access Journals (Sweden)

Xiuquan eMa

2015-01-01

Full Text Available Adipocyte differentiation and its impact on restriction or expansion of particular adipose tissue depots has physiological and pathophysiological significance in view of the different functions of these depots. Brown or beige fat [BAT] expansion can enhance thermogenesis, lipid oxidation, insulin sensitivity and glucose tolerance; conversely expanded visceral fat [VAT] is associated with insulin resistance, low grade inflammation, dyslipidaemia and cardiometabolic risk. The largest depot, subcutaneous white fat [WAT], has important beneficial characteristics including storage of lipid out of harms way and secretion of adipokines, especially leptin and adiponectin, with positive metabolic effects including lipid oxidation, energy utilisation, enhanced insulin action and an anti-inflammatory role. The absence of these functions in lipodystrophies leads to major metabolic disturbances. An ability to expand WAT adipocyte differentiation would seem an important defence mechanism against the detrimental effects of energy excess and limit harmful accumulation of lipid in ectopic sites, such as liver and muscle.Adipocyte differentiation involves a transcriptional cascade with PPARg being most important in WAT but less so in VAT, with increased angiogenesis also critical. The transcription factor, Islet1, is fairly specific to VAT and in vitro inhibits adipocyte differentiation. The physiological importance of Islet1 requires further study. Basic control of differentiation is similar in BAT but important differences include the effect of PGC-1a on mitochondrial biosynthesis and upregulation of UCP1; also PRDM16 plays a pivotal role in expression of the BAT phenotype.Modulation of the capacity or function of these different adipose tissue depots, by altering adipocyte differentiation or other means, holds promise for interventions that can be helpful in human disease, particularly cardiometabolic disorders associated with the world wide explosion of

Cryogenic systems for inertial fusion energy

International Nuclear Information System (INIS)

Chatain, D.; Perin, J.P.; Bonnay, P.; Bouleau, E.; Chichoux, M.; Communal, D.; Manzagol, J.; Viargues, F.; Brisset, D.; Lamaison, V.; Paquignon, G.

2008-01-01

The Low Temperatures Laboratory of CEA/Grenoble (France) is involved in the development of cryogenic systems for inertial fusion since a ten of years. A conceptual design for the cryogenic infrastructure of the Laser MegaJoule (LMJ) facility has been proposed. Several prototypes have been designed, built and tested like for example the 1500 bars cryo-compressor for the targets filling, the target positioner and the thermal shroud remover. The HIPER project will necessitate the development of such equipments. The main difference is that this time, the cryogenic targets are direct drive targets. The first phase of HIPER experiments is a single shot period. Based oil the experience gained the last years, not only by our laboratory but also by Omega and G.A teams, we could design the new HIPER equipments for this phase. Some experimental results obtained with the prototypes of the LMJ cryogenic system are given and a first conceptual design for the HIPER single shot cryogenic system is shown. (authors)

Thermal Vacuum Test Correlation of a Zero Propellant Load Case Thermal Capacitance Propellant Gauging Analytical Model

Science.gov (United States)

Mckim, Stephen A.

2016-01-01

This thesis describes the development and correlation of a thermal model that forms the foundation of a thermal capacitance spacecraft propellant load estimator. Specific details of creating the thermal model for the diaphragm propellant tank used on NASA's Magnetospheric Multiscale spacecraft using ANSYS and the correlation process implemented are presented. The thermal model was correlated to within plus or minus 3 degrees Celsius of the thermal vacuum test data, and was determined sufficient to make future propellant predictions on MMS. The model was also found to be relatively sensitive to uncertainties in applied heat flux and mass knowledge of the tank. More work is needed to improve temperature predictions in the upper hemisphere of the propellant tank where predictions were found to be 2 to 2.5 C lower than the test data. A road map for applying the model to predict propellant loads on the actual MMS spacecraft toward its end of life in 2017-2018 is also presented.

Hotline Allegations Involving Contracts for Programmed Depot Maintenance of KC-135 Aircraft

National Research Council Canada - National Science Library

1998-01-01

Introduction. We performed the audit in response to 15 allegations made to the Defense Hotline involving two contracts on the Programmed Depot Maintenance of the KC-135 Aircraft, which Oklahoma City Air logistics...

Use of depot medroxyprogesterone acetate and fracture risk

OpenAIRE

Meier, Christian; Brauchli, Yolanda B.; Jick, Susan S.; Kraenzlin, Marius E.; Meier, Christoph R.

2010-01-01

Depot medroxyprogesterone acetate (DMPA), which has a high rate of use among teenagers in Europe and the United States, has been associated with impaired bone mineral acquisition during adolescence and accelerated bone loss in later life. Studies on the association between DMPA use and fracture risk are limited.; We aimed at evaluating the relationship between use of hormonal contraceptives, specifically DMPA, and fracture risk.; We conducted a case-control analysis using the United Kingdom-b...

Cryogenics; Criogenia

Energy Technology Data Exchange (ETDEWEB)

Gutierrez R, C; Jimenez D, J; Cejudo A, J; Hernandez M, V [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

1997-07-01

Cryogenics is one of these technologies which contributes to scientific research that supports to the industry in the following benefits: 1. Storage ability and a great quantity of dense gases with cryogenic liquid which is found at high pressure. 2. Production ability at low cost with high purity gases through distillation or condensation. 3. Ability to use low temperatures in the refrigerating materials or alteration of the physical properties. This technology is used for reprocessing of those short and long half life radioactive wastes which always have been required that to be separated with classical methods. In this text we report the radioactive wastes separation by more sophisticated methods but more quickly and reliable. (Author)

Drag and Torque on Locked Screw Propeller

Directory of Open Access Journals (Sweden)

Tomasz Tabaczek

2014-09-01

Full Text Available Few data on drag and torque on locked propeller towed in water are available in literature. Those data refer to propellers of specific geometry (number of blades, blade area, pitch and skew of blades. The estimation of drag and torque of an arbitrary propeller considered in analysis of ship resistance or propulsion is laborious. The authors collected and reviewed test data available in the literature. Based on collected data there were developed the empirical formulae for estimation of hydrodynamic drag and torque acting on locked screw propeller. Supplementary CFD computations were carried out in order to prove the applicability of the formulae to modern moderately skewed screw propellers.

The Cyogenic Evaluation of Irradiated Composite Materials for Use in Composite Pressure Vessels, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — The intent of this proposal is to develop key building block technology for lightweight composite structures suitable for cryogenic fuel depot storage as well as...

Noise from Two-Blade Propellers

Science.gov (United States)

Stowell, E Z; Deming, A F

1936-01-01

The two-blade propeller, one of the most powerful sources of sound known, has been studied with the view of obtaining fundamental information concerning the noise emission. In order to eliminate engine noise, the propeller was mounted on an electric motor. A microphone was used to pick up the sound whose characteristics were studied electrically. The distribution of noise throughout the frequency range, as well as the spatial distribution about the propeller, was studied. The results are given in the form of polar diagrams. An appendix of common acoustical terms is included.

Fatty acid composition of subcutaneous and kidney fat depots of ...

African Journals Online (AJOL)

60. Fatty acid composition of subcutaneous and kidney fat depots of Boer goats and the response to varying levels of maize meal. N.H. Casey" and W.A. van Niekerk. Department of Animal Science, Faculty of Agriculture,. University of Pretoria, Pretoria, 0002 Republic of South Africa. xTo whom correspondence should be ...

Evidence for Environmental Contamination in Residential Neighborhoods Surrounding the Defense Depot of Memphis, Tennessee

Directory of Open Access Journals (Sweden)

Cynthia Warrick

2006-09-01

Full Text Available An interdisciplinary environmental assessment team from the Howard University Environmental Justice Partnership (HUEJP conducted a site visit and assessment of the Defense Depot of Memphis, Tennessee in February of 2000. This depot was built in the late 1940’s for storage of numerous chemicals and munitions. As the years progressed, many Memphis citizens have grown to believe that the activities and chemical stockpile located at this site have negatively affected the health environment of their residents. There is anecdotal evidence and documentation of numerous cancers and other illnesses in those local territories, and specifically, at the Memphis Depot site. Currently, this depot is closed and in remediation by the local government. Particularly, citizens of the Rozelle community have started a campaign to investigate any signs of exposure pathways to noted health risks. The HUEJP was contacted and asked to investigate the community concerns. Obliging to the request, we aimed to sample at three drainage sites and a residential site, talk to local citizens, and gain any additional information that would be helpful in relieving anxiety in the Rozelle community. Soil, sediment, and water samples were collected and analyzed for total organic carbon, inorganic anions, and heavy metals. These data show that for the four sites sampled, the highest concentrations of organic compounds and heavy metals were located either within a residential area or in an area with a direct transport pathway to the community. Atomic absorption analysis revealed detectable amounts of cadmium, lead and chromium metals at all sites with direct transport pathways into the residential community, with chromium concentrations being far in excess of the EPA standard limits.

Proceedings of the 26th International Cryogenic Engineering Conference - International Cryogenic Material Conference 2016

Science.gov (United States)

Datta, T. S.; Sharma, R. G.; Kar, S.

2017-02-01

International Conference ICEC 26 - ICMC 2016 was organized at New Delhi, India during March 7-11, 2016. Previous conference ICEC25-ICMC 2014 was held at the University of Twente, The Netherlands in July 2014. Next Conference ICEC 27- ICMC 2018 will be held at Oxford, UK during September 3-7, 2018 1. Introduction This is a biennial international conference on cryogenic engineering and cryogenics materials organized by the International Cryogenic Engineering Committee and the International Cryogenic Material Committee. For some years, the host country has been alternating between Europe and Asia. The present conference was held at the Manekshaw Convention Centre, New Delhi, India during March 7-11, 2016 and hosted jointly by the Indian Cryogenics Council (ICC) and the Inter-University Accelerator Centre (IUAC), New Delhi. Put all together as many as 547 persons participated in the conference. Out of these 218 were foreign delegates coming from 25 countries and the rest from India. 2. Inaugural Session & Course Lectures The pre conference short course lectures on “Cryocoolers” and “Superconducting Materials for Power Applications” were organized on 7th March. Cryocooler course was given jointly by Dr. Chao Wang from M/s. Cryomech, USA and Prof. Milind Atrey from IIT Bombay, India. The Course on Superconducting Materials was given by Prof. Venkat Selvamanickam from the University of Houston, USA. The conference was inaugurated in the morning of March 8th in a typical Indian tradition and in the presence of the Chief Guest, Dr. R Chidambaram (Principle Scientific Adviser to Govt. of India), Guest of Honour, Prof. H Devaraj (Vice Chairman University Grant Commission), Prof Marcel ter Brake ( Chair, ICEC Board), Prof. Wilfried Goldacker (Chair, ICMC board), Dr. D Kanjilal (Director IUAC), Dr R K Bhandari, (President, Indian Cryogenic Council ). Dr. T S Datta, Chair Local Organizing Committee coordinated the proceedings of the inaugural function. 3. Technical

PIP-II Cryogenic System and the evolution of Superfluid Helium Cryogenic Plant Specifications

Energy Technology Data Exchange (ETDEWEB)

Chakravarty, Anindya [Fermilab; Rane, Tejas [Fermilab; Klebaner, Arkadiy [Fermilab

2017-07-06

The PIP-II cryogenic system consists of a Superfluid Helium Cryogenic Plant (SHCP) and a Cryogenic Distribution System (CDS) connecting the SHCP to the Superconducting (SC) Linac consisting of 25 cryomodules. The dynamic heat load of the SC cavities for continuous wave (CW) as well as pulsed mode of operation has been listed out. The static heat loads of the cavities along with the CDS have also been discussed. Simulation study has been carried out to compute the supercritical helium (SHe) flow requirements for each cryomodule. Comparison between the flow requirements of the cryomodules for the CW and pulsed modes of operation have also been made. From the total computed heat load and pressure drop values in the CDS, the basic specifications for the SHCP, required for cooling the SC Linac, have evolved.

Propeller Flaps: A Literature Review.

Science.gov (United States)

Sisti, Andrea; D'Aniello, Carlo; Fortezza, Leonardo; Tassinari, Juri; Cuomo, Roberto; Grimaldi, Luca; Nisi, Giuseppe

2016-01-01

Since their introduction in 1991, propeller flaps are increasingly used as a surgical approach to loss of substance. The aim of this study was to evaluate the indications and to verify the outcomes and the complication rates using this reconstructing technique through a literature review. A search on PubMed was performed using "propeller flap", "fasciocutaneous flap", "local flap" or "pedicled flap" as key words. We selected clinical studies using propeller flaps as a reconstructing technique. We found 119 studies from 1991 to 2015. Overall, 1,315 propeller flaps were reported in 1,242 patients. Most frequent indications included loss of substance following tumor excision, repair of trauma-induced injuries, burn scar contractures, pressure sores and chronic infections. Complications were observed in 281/1242 patients (22.6%) occurring more frequently in the lower limbs (31.8%). Partial flap necrosis and venous congestion were the most frequent complications. The complications' rate was significantly higher in infants (70 years old) but there was not a significant difference between the sexes. Trend of complication rate has not improved during the last years. Propeller flaps showed a great success rate with low morbidity, quick recovery, good aesthetic outcomes and reduced cost. The quality and volume of the transferred soft tissue, the scar orientation and the possibility of direct donor site closure should be considered in order to avoid complications. Indications for propeller flaps are small- or medium-sized defects located in a well-vascularized area with healthy surrounding tissues. Copyright © 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

Cryogenics bringing the temperature down, underground

CERN Multimedia

2005-01-01

The first 600m of the LHC cryogenic distribution line (QRL), which will feed the accelerator's superconducting magnets, has passed initial validating tests of its mechanical design at room and cryogenic temperatures.

Disposal of Liquid Propellants

Science.gov (United States)

1990-03-13

propellant includes an oxi- dizer (hydroxylammoniuin nitrate), a fuel (triethanolammonium nitrate), and water . In an- ticipation of widespread (both...are also included. 20. DISTRIBUTION/ AVAILABILIT ’." OF ABMTRACT 21 ABSTRACT SECURITY CLASSIF.CATICIN IUNCLASSIFIEDIUNLIMITED 0 SAME AS RPT. 0 OTIC...trieth- anolammoiur nitrate), anG water . In anticipation of widespread (both conti- nental U.S. and abroac) use of the propellant, USATHAMA began a

Elucidation of molecular mechanisms of physiological variations between bovine subcutaneous and visceral fat depots under different nutritional regimes.

Directory of Open Access Journals (Sweden)

Josue Moura Romao

Full Text Available Adipose tissue plays a critical role in energy homeostasis and metabolism. There is sparse understanding of the molecular regulation at the protein level of bovine adipose tissues, especially within different fat depots under different nutritional regimes. The objective of this study was to analyze the differences in protein expression between bovine subcutaneous and visceral fat depots in steers fed different diets and to identify the potential regulatory molecular mechanisms of protein expression. Subcutaneous and visceral fat tissues were collected from 16 British-continental steers (15.5 month old fed a high-fat diet (7.1% fat, n=8 or a control diet (2.7% fat, n=8. Protein expression was profiled using label free quantification LC-MS/MS and expression of selected transcripts was evaluated using qRT-PCR. A total of 682 proteins were characterized and quantified with fat depot having more impact on protein expression, altering the level of 51.0% of the detected proteins, whereas diet affected only 5.3%. Functional analysis revealed that energy production and lipid metabolism were among the main functions associated with differentially expressed proteins between fat depots, with visceral fat being more metabolically active than subcutaneous fat as proteins associated with lipid and energy metabolism were upregulated. The expression of several proteins was significantly correlated to subcutaneous fat thickness and adipocyte size, indicating their potential as adiposity markers. A poor correlation (r=0.245 was observed between mRNA and protein levels for 9 genes, indicating that many proteins may be subjected to post-transcriptional regulation. A total of 8 miRNAs were predicted to regulate more than 20% of lipid metabolism proteins differentially expressed between fat depots, suggesting that miRNAs play a role in adipose tissue regulation. Our results show that proteomic changes support the distinct metabolic and physiological characteristics

Kodak AMSD Cryogenic Test Plans

Science.gov (United States)

Matthews, Gary; Hammon, John; Barrett, David; Russell, Kevin (Technical Monitor)

2002-01-01

NGST will be an IR based optical system that will operate at cryogenic temperatures. As part of the AMSD program, Kodak must demonstrate the ability of our system to perform at these very cold temperatures. Kodak will discuss the test approach that will be used for cryogenic testing at MSFC's XRCF.

A theoretical and experimental investigation of propeller performance methodologies

Science.gov (United States)

Korkan, K. D.; Gregorek, G. M.; Mikkelson, D. C.

1980-01-01

This paper briefly covers aspects related to propeller performance by means of a review of propeller methodologies; presentation of wind tunnel propeller performance data taken in the NASA Lewis Research Center 10 x 10 wind tunnel; discussion of the predominent limitations of existing propeller performance methodologies; and a brief review of airfoil developments appropriate for propeller applications.

On the multiple depots vehicle routing problem with heterogeneous fleet capacity and velocity

Science.gov (United States)

Hanum, F.; Hartono, A. P.; Bakhtiar, T.

2018-03-01

This current manuscript concerns with the optimization problem arising in a route determination of products distribution. The problem is formulated in the form of multiple depots and time windowed vehicle routing problem with heterogeneous capacity and velocity of fleet. Model includes a number of constraints such as route continuity, multiple depots availability and serving time in addition to generic constraints. In dealing with the unique feature of heterogeneous velocity, we generate a number of velocity profiles along the road segments, which then converted into traveling-time tables. An illustrative example of rice distribution among villages by bureau of logistics is provided. Exact approach is utilized to determine the optimal solution in term of vehicle routes and starting time of service.

Cavitation noise studies on marine propellers

Science.gov (United States)

Sharma, S. D.; Mani, K.; Arakeri, V. H.

1990-04-01

Experimental observations are described of cavitation inception and noise from five model propellers, three basic and two modified, tested in the open jet section of the Indian Institute of Science high-speed water tunnel facility. Extensive experiments on the three basic propellers of different design, which included visualization of cavitation and measurements of noise, showed that the dominant type of cavitation was in the form of tip vortex cavitation, accompanied by leading edge suction side sheet cavitation in its close vicinity, and the resultant noise depended on parameters such as the advance coefficient, the cavitation number, and the propeller geometry. Of these, advance coefficient was found to have the maximum influence not only on cavitation noise but also on the inception of cavitation. Noise levels and frequencies of spectra obtained from all the three basic propellers at conditions near inception and different advance coefficient values, when plotted in the normalized form as suggested by Blake, resulted in a universal spectrum which would be useful for predicting cavitation noise at prototype scales when a limited extent of cavitation is expected in the same form as observed on the present models. In an attempt to delay the onset of tip vortex cavitation, the blades of two of the three basic propellers were modified by drilling small holes in the tip and leading edge areas. Studies on the modified propellers showed that the effectiveness of the blade modification was apparently stronger at low advance coefficient values and depended on the blade sectional profile. Measurements of cavitation noise indicated that the modification also improved the acoustic performance of the propellers as it resulted in a complete attenuation of the low-frequency spectral peaks, which were prominent with the basic propellers. In addition to the above studies, which were conducted under uniform flow conditions, one of the basic propellers was tested in the simulated

Commissioning the cryogenic system of the first LHC sector

International Nuclear Information System (INIS)

Millet, F.; Claudet, S.; Ferlin, G.; Perin, A.; Riddone, G.; Serio, L.; Soubiran, M.; Tavian, L.; CERN; Ronayette, L.; GHMFL, Grenoble; Rabehl, R.; Fermilab

2007-01-01

The LHC machine, composed of eight sectors with superconducting magnets and accelerating cavities, requires a complex cryogenic system providing high cooling capacities (18 kW equivalent at 4.5 K and 2.4 W at 1.8 K per sector produced in large cold boxes and distributed via 3.3-km cryogenic transfer lines). After individual reception tests of the cryogenic subsystems (cryogen storages, refrigerators, cryogenic transfer lines and distribution boxes) performed since 2000, the commissioning of the cryogenic system of the first LHC sector has been under way since November 2006. After a brief introduction to the LHC cryogenic system and its specificities, the commissioning is reported detailing the preparation phase (pressure and leak tests, circuit conditioning and flushing), the cool-down sequences including the handling of cryogenic fluids, the magnet powering phase and finally the warm-up. Preliminary conclusions on the commissioning of the first LHC sector will be drawn with the review of the critical points already solved or still pending. The last part of the paper reports on the first operational experience of the LHC cryogenic system in the perspective of the commissioning of the remaining LHC sectors and the beam injection test

The cryogenic control system of BEPCⅡ

Institute of Scientific and Technical Information of China (English)

LI Gang; WANG Ke-Xiang; ZHAO Ji-Jiu; YUE Ke-Juan; DAI Ming-Sui; HUANG Yi-Ling; JIANG Bo

2008-01-01

A superconducting cryogenic system has been designed and deployed in the Beijing Electron-Positron Collider Upgrade Project(BEPCⅡ).The system consists of a Siemens PLC(ST-PLC,Programmable Logic Controller)for the compressor control,an Allen Bradley(AB)PLC for the cryogenic equipments,and the Experimental Physics and Industrial Control System(EPICS)that integrates the PLCs.The system fully automates the superconducting cryogenic control with process control,PID(Proportional-Integral-Differential)control loops,real-time data access and data storage,alarm handler and human machine interface.It is capable of automatic recovery as well.This paper describes the BEPCⅡ cryogenic control system,data communication between ST-PLC and EPICS Input/Output Controllers(IOCs),and the integration of the flow control,the low level interlock,the AB-PLC,and EPICS.

Modeling and analysis of chill and fill processes for the cryogenic storage and transfer engineering development unit tank

Science.gov (United States)

Hedayat, A.; Cartagena, W.; Majumdar, A. K.; LeClair, A. C.

2016-03-01

NASA's future missions may require long-term storage and transfer of cryogenic propellants. The Engineering Development Unit (EDU), a NASA in-house effort supported by both Marshall Space Flight Center (MSFC) and Glenn Research Center, is a cryogenic fluid management (CFM) test article that primarily serves as a manufacturing pathfinder and a risk reduction task for a future CFM payload. The EDU test article comprises a flight-like tank, internal components, insulation, and attachment struts. The EDU is designed to perform integrated passive thermal control performance testing with liquid hydrogen (LH2) in a test-like vacuum environment. A series of tests, with LH2 as a testing fluid, was conducted at Test Stand 300 at MSFC during the summer of 2014. The objective of this effort was to develop a thermal/fluid model for evaluating the thermodynamic behavior of the EDU tank during the chill and fill processes. The Generalized Fluid System Simulation Program, an MSFC in-house general-purpose computer program for flow network analysis, was utilized to model and simulate the chill and fill portion of the testing. The model contained the LH2 supply source, feed system, EDU tank, and vent system. The test setup, modeling description, and comparison of model predictions with the test data are presented.

A breath of fresh air for cryogenics training

CERN Multimedia

HSE Unit

2014-01-01

Whether you work full-time in a cryogenic installation or are required to handle cryogenic substances temporarily, you need to have followed the appropriate safety training.   Photo: Christoph Balle. Two new training courses are now available in English and French at CERN: “Cryogenic Safety – Fundamentals” (at the Prévessin Training Centre) and “Cryogenic Safety – Helium Transfer” (at the Cryolab). The first covers the content of levels 1 and 2 of the old “Cryogenic Safety” course. The second is a completely new course for CERN: it covers specific aspects of the transfer of liquid helium, such as the evaporation process of helium and the associated risks to human health (asphyxia due to displacement of oxygen), the colour code for gas bottles, etc. These training modules have been rewritten in response to the increase in the number of projects involving cryogenics and following various related incident...

Process and Energy Optimization Assessment, Tobyhanna Army Depot, PA

Science.gov (United States)

2006-04-17

assembly of electronic-communication components, different welding processes are performed at TYAD. It uses shielded arc, metal inert gas (MIG...tungsten inert gas ( TIG ), and silver braz- ing oxygen/acetylene cutting plasma arc methods to complete mission re- quirements. Major welding jobs are...ER D C/ CE R L TR -0 6 -1 1 Process and Energy Optimization Assessment Tobyhanna Army Depot, PA Mike C.J. Lin, Alexander M. Zhivov

Tests on thirteen navy type model propellers

Science.gov (United States)

Durand, W F

1927-01-01

The tests on these model propellers were undertaken for the purpose of determining the performance coefficients and characteristics for certain selected series of propellers of form and type as commonly used in recent navy designs. The first series includes seven propellers of pitch ratio varying by 0.10 to 1.10, the area, form of blade, thickness, etc., representing an arbitrary standard propeller which had shown good results. The second series covers changes in thickness of blade section, other things equal, and the third series, changes in blade area, other things equal. These models are all of 36-inch diameter. Propellers A to G form the series on pitch ratio, C, N. I. J the series on thickness of section, and K, M, C, L the series on area. (author)

Infrared detectors and test technology of cryogenic camera

Science.gov (United States)

Yang, Xiaole; Liu, Xingxin; Xing, Mailing; Ling, Long

2016-10-01

Cryogenic camera which is widely used in deep space detection cools down optical system and support structure by cryogenic refrigeration technology, thereby improving the sensitivity. Discussing the characteristics and design points of infrared detector combined with camera's characteristics. At the same time, cryogenic background test systems of chip and detector assembly are established. Chip test system is based on variable cryogenic and multilayer Dewar, and assembly test system is based on target and background simulator in the thermal vacuum environment. The core of test is to establish cryogenic background. Non-uniformity, ratio of dead pixels and noise of test result are given finally. The establishment of test system supports for the design and calculation of infrared systems.

Abdominal fat sub-depots and energy expenditure: Magnetic resonance imaging study.

Science.gov (United States)

Serfaty, Dana; Rein, Michal; Schwarzfuchs, Dan; Shelef, Ilan; Gepner, Yftach; Bril, Nitzan; Cohen, Noa; Shemesh, Elad; Sarusi, Benjamin; Kovsan, Julia; Kenigsbuch, Shira; Chassidim, Yoash; Golan, Rachel; Witkow, Shula; Henkin, Yaakov; Stampfer, Meir J; Rudich, Assaf; Shai, Iris

2017-06-01

We aimed to assess the association between the distinct abdominal sub-depots and resting energy expenditure (REE). We performed magnetic resonance imaging (MRI) to quantify abdominal visceral-adipose-tissue (VAT), deep-subcutaneous-adipose-tissue (deep-SAT), and superficial-subcutaneous-adipose-tissue (superficial-SAT). We measured REE by indirect-calorimetry. Non-exercise activity thermogenesis (NEAT) [1-3 metabolic equivalents (METs)] and exercise thermogenesis (activities of 4+MET S ) were estimated based on 6-days of accelerometry to assess total physical activity energy expenditure (PAEE). We studied 282 participants: 249 men [mean age = 47.4 years, body-mass-index (BMI) = 31 kg/m 2 , mean VAT proportion from total abdominal fat = 34.5%, mean superficial-SAT proportion from total abdominal fat = 24.3%] and 33 women (mean age = 51.2 years, BMI = 30.1 kg/m 2 , mean VAT proportion from total abdominal fat = 22.8%, mean superficial-SAT proportion from total abdominal fat = 37.8%). As expected, women had lower REE [by 32.4% (1488 ± 234 kcal/day vs. 1971 ± 257 kcal/day; p abdominal VAT was the dominant proportional depot, had higher REE (1964 ± 297 kcal/day vs. 1654 ± 352 kcal/day; p Abdominal fat distribution patterns are associated with varying levels of resting energy expenditure, potentially reflecting different metabolic rates of adipose sub-depots and providing an anatomic/anthropometric link to physiological obese sub-phenotypes. Copyright © 2016 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

A Reference Guide for Cryogenic Properties of Materials

Energy Technology Data Exchange (ETDEWEB)

Weisend, John G

2003-09-16

A thorough knowledge of the behavior of materials at cryogenic temperatures is critical for the design of successful cryogenic systems. Over the past 50 years, a tremendous amount of material properties at cryogenic temperatures have been measured and published. This guide lists resources for finding these properties. It covers online databases, computer codes, conference proceedings, journals, handbooks, overviews and monographs. It includes references for finding reports issued by government laboratories and agencies. Most common solids and fluids used in cryogenics are covered.

Seawater Immersion of GEM II Propellant

National Research Council Canada - National Science Library

Merrill, Calude

1999-01-01

... (% AP lost/week aged in seawater) and intercepts that depend on sample size. Friction and impact data on dried aged propellant samples showed no increased burning hazard compared with propellant not exposed to water...

Coupled Cryogenic Thermal and Electrical Models for Transient Analysis of Superconducting Power Devices with Integrated Cryogenic Systems

Science.gov (United States)

Satyanarayana, S.; Indrakanti, S.; Kim, J.; Kim, C.; Pamidi, S.

2017-12-01

Benefits of an integrated high temperature superconducting (HTS) power system and the associated cryogenic systems on board an electric ship or aircraft are discussed. A versatile modelling methodology developed to assess the cryogenic thermal behavior of the integrated system with multiple HTS devices and the various potential configurations are introduced. The utility and effectiveness of the developed modelling methodology is demonstrated using a case study involving a hypothetical system including an HTS propulsion motor, an HTS generator and an HTS power cable cooled by an integrated cryogenic helium circulation system. Using the methodology, multiple configurations are studied. The required total cooling power and the ability to maintain each HTS device at the required operating temperatures are considered for each configuration and the trade-offs are discussed for each configuration. Transient analysis of temperature evolution in the cryogenic helium circulation loop in case of a system failure is carried out to arrive at the required critical response time. The analysis was also performed for a similar liquid nitrogen circulation for an isobaric condition and the cooling capacity ratio is used to compare the relative merits of the two cryogens.

Large Cryogenic Infrastructure for LHC Superconducting Magnet and Cryogenic Component Tests: Layout, Commissioning and Operational Experience

International Nuclear Information System (INIS)

Calzas, C.; Chanat, D.; Knoops, S.; Sanmarti, M.; Serio, L.

2004-01-01

The largest cryogenic test facility at CERN, located at Zone 18, is used to validate and to test all main components working at cryogenic temperature in the LHC (Large Hadron Collider) before final installation in the machine tunnel. In total about 1300 main dipoles, 400 main quadrupoles, 5 RF-modules, eight 1.8 K refrigeration units will be tested in the coming years.The test facility has been improved and upgraded over the last few years and the first 18 kW refrigerator for the LHC machine has been added to boost the cryogenic capacity for the area via a 25,000 liter liquid helium dewar. The existing 6 kW refrigerator, used for the LHC Test String experiments, will also be employed to commission LHC cryogenic components.We report on the design and layout of the test facility as well as the commissioning and the first 10,000 hours operational experience of the test facility and the 18 kW LHC refrigerator

The PROPEL Electrodynamic Tether Demonstration Mission

Science.gov (United States)

Bilen, Sven G.; Johnson, C. Les; Wiegmann, Bruce M.; Alexander, Leslie; Gilchrist, Brian E.; Hoyt, Robert P.; Elder, Craig H.; Fuhrhop, Keith P.; Scadera, Michael

2012-01-01

The PROPEL ("Propulsion using Electrodynamics") mission will demonstrate the operation of an electrodynamic tether propulsion system in low Earth orbit and advance its technology readiness level for multiple applications. The PROPEL mission has two primary objectives: first, to demonstrate the capability of electrodynamic tether technology to provide robust and safe, near-propellantless propulsion for orbit-raising, de-orbit, plane change, and station keeping, as well as to perform orbital power harvesting and formation flight; and, second, to fully characterize and validate the performance of an integrated electrodynamic tether propulsion system, qualifying it for infusion into future multiple satellite platforms and missions with minimal modification. This paper provides an overview of the PROPEL system and design reference missions; mission goals and required measurements; and ongoing PROPEL mission design efforts.

Inflammation and race and gender differences in computerized tomography-measured adipose depots

NARCIS (Netherlands)

Beasley, L.E.; Koster, A.; Newman, A.B.; Javaid, M.K.; Ferucci, L.; Kritchevsky, S.B.; Kuller, L.H.; Pahor, M.; Visser, M.; Rubin, S.M.; Goodpaster, B.H.; Everhart, J.E.; Harris, T.B.

2009-01-01

A growing body of evidence has consistently shown a correlation between obesity and chronic subclinical inflammation. It is unclear whether the size of specific adipose depots is more closely associated with concentrations of inflammatory markers than overall adiposity. This study investigated the

Cryogenic support member

International Nuclear Information System (INIS)

Niemann, R.C.; Gonczy, J.D.; Nicol, T.H.

1987-01-01

A cryogenic support member is described for restraining a cryogenic system comprising; a rod having a depression at a first end. The rod is made of non-metallic material. The non-metallic material has an effectively low thermal conductivity; a metallic plug; and a metallic sleeve. The plug and the sleeve are shrink-fitted to the depression in the rod and assembled thereto such that the plug is disposed inside the depression of the rod. The sleeve is disposed over the depression in the rod and the rod is clamped therebetween. The shrink-fit clamping the rod is generated between the metallic plug and the metallic sleeve

78 FR 4038 - Critical Parts for Airplane Propellers

Science.gov (United States)

2013-01-18

... manufacturers are not required to provide information concerning propeller critical part design, manufacture, or... engineering, manufacturing, and service management processes should provide clear information for propeller... manufacture critical parts for airplane propellers update their manuals to record engineering, manufacture...

Ionic liquid propellants: future fuels for space propulsion.

Science.gov (United States)

Zhang, Qinghua; Shreeve, Jean'ne M

2013-11-11

Use of green propellants is a trend for future space propulsion. Hypergolic ionic liquid propellants, which are environmentally-benign while exhibiting energetic performances comparable to hydrazine, have shown great potential to meet the requirements of developing nontoxic high-performance propellant formulations for space propulsion applications. This Concept article presents a review of recent advances in the field of ionic liquid propellants. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Status of the LBNF Cryogenic System

CERN Document Server

Montanari, D; Bremer, J; Delany, M; Diaz, A; Doubnik, R; Haaf, K; Henstchel, S; Norris, B; Voirin, E

2017-01-01

The Sanford Underground Research Facility (SURF) will host the Deep Underground Neutrino Experiment (DUNE), an international multi-kiloton Long-Baseline neutrino experiment that will be installed about a mile underground in Lead, SD. In the current configuration four cryostats will contain a modular detector and a total of 68,400 tons of ultrapure liquid argon, with a level of impurities lower than 100 parts per trillion of oxygen equivalent contamination. The Long-Baseline Neutrino Facility (LBNF) provides the conventional facilities and the cryogenic infrastructure to support DUNE. The system is comprised of three sub-systems: External/Infrastructure, Proximity and Internal cryogenics. An international engineering team will design, manufacture, commission, and qualify the LBNF cryogenic system. This contribution presents the modes of operations, layout and main features of the LBNF cryogenic system. The expected performance, the functional requirements and the status of the design are also highlighted.

Status of the LBNF Cryogenic System

Science.gov (United States)

Montanari, D.; Adamowski, M.; Bremer, J.; Delaney, M.; Diaz, A.; Doubnik, R.; Haaf, K.; Hentschel, S.; Norris, B.; Voirin, E.

2017-12-01

The Sanford Underground Research Facility (SURF) will host the Deep Underground Neutrino Experiment (DUNE), an international multi-kiloton Long-Baseline neutrino experiment that will be installed about a mile underground in Lead, SD. In the current configuration four cryostats will contain a modular detector and a total of 68,400 tons of ultrapure liquid argon, with a level of impurities lower than 100 parts per trillion of oxygen equivalent contamination. The Long-Baseline Neutrino Facility (LBNF) provides the conventional facilities and the cryogenic infrastructure to support DUNE. The system is comprised of three sub-systems: External/Infrastructure, Proximity and Internal cryogenics. An international engineering team will design, manufacture, commission, and qualify the LBNF cryogenic system. This contribution presents the modes of operations, layout and main features of the LBNF cryogenic system. The expected performance, the functional requirements and the status of the design are also highlighted.

49 CFR 173.316 - Cryogenic liquids in cylinders.

Science.gov (United States)

2010-10-01

... filling density for hydrogen, cryogenic liquid is defined as the percent ratio of the weight of lading in... 49 Transportation 2 2010-10-01 2010-10-01 false Cryogenic liquids in cylinders. 173.316 Section... REQUIREMENTS FOR SHIPMENTS AND PACKAGINGS Gases; Preparation and Packaging § 173.316 Cryogenic liquids in...

Characterization of a cryogenic ion guide at IGISOL

NARCIS (Netherlands)

Saastamoinen, A.; Moore, I. D.; Ranjan, M.; Dendooven, P.; Penttila, H.; Perajarvi, K.; Popov, A.; Aysto, J.

2012-01-01

A small volume cryogenic ion guide has been characterized at the IGISOL facility, Jyvaskyla, as a prototype to verify whether there are any major obstacles to the use of high-density cryogenic helium gas for the stopping and extraction of high-energy ions from a large volume cryogenic ion catcher.

Advances in cryogenic engineering. Volume 27 - Proceedings of the Cryogenic Engineering Conference, San Diego, CA, August 11-14, 1981

Science.gov (United States)

Fast, R. W.

Applications of superconductivity are considered, taking into account MHD and fusion, generators, transformers, transmission lines, magnets for physics, cryogenic techniques, electrtronics, and aspects of magnet stability. Advances related to heat transfer in He I are discussed along with subjects related to theat transfer in He II, refrigeration of superconducting systems, refrigeration and liquefaction, dilution and magnetic refrigerators, refrigerators for space applications, mass transfer and flow phenomena, and the properties of fluids. Developments related to cryogenic applications are also explored, giving attention to bulk storage and transfer of cryogenic fluids, liquefied natural gas operations, space science and technology, and cryopumping. Topics related to cryogenic instrumentation and controls include the production and use of high grade silicon diode temperature sensors, the choice of strain gages for use in a large superconducting alternator, microprocessor control of cryogenic pressure, and instrumentation, data acquisition and reduction for a large spaceborne helium dewar. For individual items see A83-43221 to A83-43250

Advanced Chemical Propulsion Study

Science.gov (United States)

Woodcock, Gordon; Byers, Dave; Alexander, Leslie A.; Krebsbach, Al

2004-01-01

A study was performed of advanced chemical propulsion technology application to space science (Code S) missions. The purpose was to begin the process of selecting chemical propulsion technology advancement activities that would provide greatest benefits to Code S missions. Several missions were selected from Code S planning data, and a range of advanced chemical propulsion options was analyzed to assess capabilities and benefits re these missions. Selected beneficial applications were found for higher-performing bipropellants, gelled propellants, and cryogenic propellants. Technology advancement recommendations included cryocoolers and small turbopump engines for cryogenic propellants; space storable propellants such as LOX-hydrazine; and advanced monopropellants. It was noted that fluorine-bearing oxidizers offer performance gains over more benign oxidizers. Potential benefits were observed for gelled propellants that could be allowed to freeze, then thawed for use.

Design and simulation on the morphing composite propeller (Conference Presentation)

Science.gov (United States)

Chen, Fanlong; Li, Qinyu; Liu, Liwu; Lan, Xin; Liu, Yanju; Leng, Jinsong

2017-04-01

As one of the most crucial part of the unmanned underwater vehicle (UUV), the composite propeller plays an important role on the UUV's performance. As the composite propeller behaves excellent properties in hydroelastic facet and acoustic suppression, it attracts increasing attentions all over the globe. This paper goes a step further based on this idea, and comes up with a novel concept of "morphing composite propeller" (MCP) to improve the performance of the conventional composite propeller (CCP) to anticipate the improved propeller can perform better to propel the UUV. Based on the new concept, a novel MCP is designed. Each blade of the propeller is assembled with an active rotatable flap (ARF) to change the blade's local camber with flap rotation. Then the transmission mechanism (TM) has been designed and housed in the propeller blade to push the ARF. With the ARF rotating, the UUV can be propelled by different thrusts under certain rotation velocities of the propeller. Based on the design, the Fluent is exploited to analyze the fluid dynamics around the propeller. Finally, based on the design and hydrodynamic analysis, the structural response for the novel morphing composite propeller is calculated. The propeller blade is simplified and layered with composite materials. And the structure response of an MCP is obtained with various rotation angle under the hydrodynamic pressure. This simulation can instruct the design and fabrication techniques of the MCP.

The Future with Cryogenic Fluid Dynamics

Science.gov (United States)

Scurlock, R. G.

The applications of cryogenic systems have expanded over the past 50 years into many areas of our lives. During this time, the impact of the common features of Cryogenic Fluid Dynamics, CryoFD, on the economic design of these cryogenic systems, has grown out of a long series of experimental studies carried out by teams of postgraduate students at Southampton University.These studies have sought to understand the heat transfer and convective behavior of cryogenic liquids and vapors, but they have only skimmed over the many findings made, on the strong convective motions of fluids at low temperatures. The convection takes place in temperature gradients up to 10,000 K per meter, and density gradients of 1000% per meter and more, with rapid temperature and spatially dependent changes in physical properties like viscosity and surface tension, making software development and empirical correlations almost impossible to achieve. These temperature and density gradients are far larger than those met in other convecting systems at ambient temperatures, and there is little similarity. The paper will discuss the likely impact of CryoFD on future cryogenic systems, and hopefully inspire further research to support and expand the use of existing findings, and to improve the economy of present-day systems even more effectively. Particular examples to be mentioned include the following. Doubling the cooling power of cryo-coolers by a simple use of CryoFD. Reducing the boil-off rate of liquid helium stored at the South Pole, such that liquid helium availability is now all-the-year-round. Helping to develop the 15 kA current leads for the LHC superconducting magnets at CERN, with much reduced refrigeration loads. Improving the heat transfer capability of boiling heat transfer surfaces by 10 to 100 fold. This paper is an edited text of an invited plenary presentation at ICEC25/ICMC2014 by Professor Scurlock on the occasion of his being presented with the ICEC Mendelssohn Award for his

KANDUNGAN Pb, Cd, Hg DALAM AIR MINUM DARI DEPOT AIR MINUM ISI ULANG DI JAKARTA, TANGERANG, DAN BEKASI

Directory of Open Access Journals (Sweden)

Athena Athena

2012-11-01

Full Text Available A study on chemical quality of drinking water from reffil depots was done in Jakarta, Tangerang, and Bekasi in 2003 to determine the contents of heavy metals such as lead (Pb, cadmium, (Cd, and Mercury (Hg. A total of 38 refill depots was selected as samples. Data were collected by water sampling collection and water analysis, and interview with operators and association personal using questionairs. Water samples were analyzed using Atomic Absorption Spectrophotometer (AAS to examine the contents of their heavy metals based on raw water and drinking water standards. The results showed that the treatment processed were filtration and disinfection. However, the contents of heavy metals in the two types of water samples still complied with the standards stated in Health Ministerial Decree no 906 in the year 2002.   Keywords: heavy metals, drinking water, drinking water refill depots

Evacuation apparatus with cryogenic pump and trap assembly

International Nuclear Information System (INIS)

Mahl, G.

1980-01-01

An evacuation apparatus comprising a vessel defining a vacuum chamber therein, vacuumizing means communicating with an opening to said vacuum chamber for selectively drawing a vacuum therein comprising cryogenic pump means disposed closely adjacent to said opening and defined by substantial cryogenically cooled trap surfaces for freezing-out water vapor from air evacuated from said vacuum chamber, said opening being common to said vacuum chamber and to said cryogenic pump means, valve means for selectively opening or closing the opening to said vacuum chamber and movable from a first position within said cryogenic pump means closing said opening to a second position within said cryogenic pump means directly exposing said vacuum chamber to said cryogenic pump means, through said opening, baffle means disposed closely adjacent to the opening to said vacuum chamber for providing substantial open communication to said vacuum chamber and for substantially preventing ingress of contaminants into said vacuum chamber, said baffle means being positioned to provide an optically dense view of said opening when viewed from a downstream side of said baffle means, and a plurality of longitudinally spaced and cryogenically cooled fins mounted in nested relationship within said baffle means and disposed in out-of-contact relationship therewith, said fins being positioned to provide an optically dense view of the downstream side of said baffle means when viewed from said openings. The cryogenic pump is adapted for use in an evacuation apparatus comprising a housing defining an opening to a vacuum chamber, a plurality of metallic plates defining a first chamber therein communicating with said vacuum chamber through said opening and further defining a second chamber at least partially surrounding said first chamber and adapted to be at least partially filled with a cryogenic liqui.d

Cryogen free low temperature sample environment for neutron scattering experiments

International Nuclear Information System (INIS)

Kirichek, O; Evans, B E; Down, R B E; Bowden, Z A

2009-01-01

Recent increase in liquid helium cost caused by global helium supply problems rose significant concern about affordability of conventional cryogenic equipment. Luckily the progress in cryo-cooler technology offers a new generation of cryogenic systems with significantly reduced consumption and in some cases nearly complete elimination of cryogens. These cryogen-free systems also offer the advantage of operational simplicity and require less space than conventional cryogen-cooled systems. The ISIS facility carries on an internal development program intended to substitute gradually all conventional cryogenic systems with cryogen free systems preferably based on pulse tube refrigerators. A unique feature of this cryo-cooler is the absence of cold moving parts. This considerably reduces vibrations and increases the reliability of the cold head. The program includes few development projects which are aiming to deliver range of cryogen free equipment including top-loading cryostat, superconducting magnets and dilution refrigerators. Here we are going to describe the design of these systems and discuss the results of prototypes testing.

Cryogenics for LDR

Science.gov (United States)

Kittel, Peter

1988-01-01

Three cryogenic questions of importance to Large Deployable Reflector (LDR) are discussed: the primary cooling requirement, the secondary cooling requirement, and the instrument changeout requirement.

Thermal Vacuum Test Correlation of A Zero Propellant Load Case Thermal Capacitance Propellant Gauging Analytics Model

Science.gov (United States)

McKim, Stephen A.

2016-01-01

This thesis describes the development and test data validation of the thermal model that is the foundation of a thermal capacitance spacecraft propellant load estimator. Specific details of creating the thermal model for the diaphragm propellant tank used on NASA's Magnetospheric Multiscale spacecraft using ANSYS and the correlation process implemented to validate the model are presented. The thermal model was correlated to within plus or minus 3 degrees Centigrade of the thermal vacuum test data, and was found to be relatively insensitive to uncertainties in applied heat flux and mass knowledge of the tank. More work is needed, however, to refine the thermal model to further improve temperature predictions in the upper hemisphere of the propellant tank. Temperatures predictions in this portion were found to be 2-2.5 degrees Centigrade lower than the test data. A road map to apply the model to predict propellant loads on the actual MMS spacecraft toward its end of life in 2017-2018 is also presented.

Direct Evidence of Brown Adipocytes in Different Fat Depots in Children

Science.gov (United States)

Rockstroh, Denise; Landgraf, Kathrin; Wagner, Isabel Viola; Gesing, Julia; Tauscher, Roy; Lakowa, Nicole; Kiess, Wieland; Bühligen, Ulf; Wojan, Magdalena; Till, Holger; Blüher, Matthias; Körner, Antje

2015-01-01

Recent studies suggested the persistence of brown adipocytes in adult humans, as opposed to being exclusively present in infancy. In this study, we investigated the presence of brown-like adipocytes in adipose tissue (AT) samples of children and adolescents aged 0 to 18 years and evaluated the association with age, location, and obesity. For this, we analysed AT samples from 131 children and 23 adults by histological, immunohistochemical and expression analyses. We detected brown-like and UCP1 positive adipocytes in 10.3% of 87 lean children (aged 0.3 to 10.7 years) and in one overweight infant, whereas we did not find brown adipocytes in obese children or adults. In our samples, the brown-like adipocytes were interspersed within white AT of perirenal, visceral and also subcutaneous depots. Samples with brown-like adipocytes showed an increased expression of UCP1 (>200fold), PRDM16 (2.8fold), PGC1α and CIDEA while other brown/beige selective markers, such as PAT2, P2RX5, ZIC1, LHX8, TMEM26, HOXC9 and TBX1 were not significantly different between UCP1 positive and negative samples. We identified a positive correlation between UCP1 and PRDM16 within UCP1 positive samples, but not with any other brown/beige marker. In addition, we observed significantly increased PRDM16 and PAT2 expression in subcutaneous and visceral AT samples with high UCP1 expression in adults. Our data indicate that brown-like adipocytes are present well beyond infancy in subcutaneous depots of non-obese children. The presence was not restricted to typical perirenal locations, but they were also interspersed within WAT of visceral and subcutaneous depots. PMID:25706927

Combustion characteristics of SMX and SMX based propellants

Science.gov (United States)

Reese, David A.

This work investigates the combustion of the new solid nitrate ester 2,3-hydroxymethyl-2,3-dinitro-1,4-butanediol tetranitrate (SMX, C6H 8N6O16). SMX was synthesized for the first time in 2008. It has a melting point of 85 °C and oxygen balance of 0% to CO 2, allowing it to be used as an energetic additive or oxidizer in solid propellants. In addition to its neat combustion characteristics, this work also explores the use of SMX as a potential replacement for nitroglycerin (NG) in double base gun propellants and as a replacement for ammonium perchlorate in composite rocket propellants. The physical properties, sensitivity characteristics, and combustion behaviors of neat SMX were investigated. Its combustion is stable at pressures of up to at least 27.5 MPa (n = 0.81). The observed flame structure is nearly identical to that of other double base propellant ingredients, with a primary flame attached at the surface, a thick isothermal dark zone, and a luminous secondary flame wherein final recombination reactions occur. As a result, the burning rate and primary flame structure can be modeled using existing one-dimensional steady state techniques. A zero gas-phase activation energy approximation results in a good fit between modeled and observed behavior. Additionally, SMX was considered as a replacement for nitroglycerin in a double base propellant. Thermochemical calculations indicate improved performance when compared with the common double base propellant JA2 at SMX loadings above 40 wt-%. Also, since SMX is a room temperature solid, migration may be avoided. Like other nitrate esters, SMX is susceptible to decomposition over long-term storage due to the presence of excess acid in the crystals; the addition of stabilizers (e.g., derivatives of urea) during synthesis should be sufficient to prevent this. the addition of Both unplasticized and plasticized propellants were formulated. Thermal analysis of unplasticized propellant showed a distinct melt

Performance of clustering techniques for solving multi depot vehicle routing problem

Directory of Open Access Journals (Sweden)

Eliana M. Toro-Ocampo

2016-01-01

Full Text Available The vehicle routing problem considering multiple depots is classified as NP-hard. MDVRP determines simultaneously the routes of a set of vehicles and aims to meet a set of clients with a known demand. The objective function of the problem is to minimize the total distance traveled by the routes given that all customers must be served considering capacity constraints in depots and vehicles. This paper presents a hybrid methodology that combines agglomerative clustering techniques to generate initial solutions with an iterated local search algorithm (ILS to solve the problem. Although previous studies clustering methods have been proposed like strategies to generate initial solutions, in this work the search is intensified on the information generated after applying the clustering technique. Besides an extensive analysis on the performance of techniques, and their effect in the final solution is performed. The operation of the proposed methodology is feasible and effective to solve the problem regarding the quality of the answers and computational times obtained on request evaluated literature

Status of the Cryogenic Storage Ring (CSR)

Energy Technology Data Exchange (ETDEWEB)

Menk, Sebastian; Becker, Arno; Berg, Felix; Blaum, Klaus; Fellenberger, Florian; Froese, Michael; Goullon, Johannes; Grieser, Manfred; Krantz, Claude; Lange, Michael; Laux, Felix; Repnow, Roland; Schornikov, Andrey; Hahn, Robert von; Wolf, Andreas [Max-Planck-Institut fuer Kernphysik (MPIK), 69117 Heidelberg (Germany); Spruck, Kaija [Institut fuer Atom- und Molekuelphysik Justus-Liebig-Universitaet, 35392 Giessen (Germany)

2012-07-01

A novel cryogenic storage ring is currently under construction at the MPIK. By electrostatic ion optical elements, the 35 m circumference Cryogenic Storage Ring will be able to store ions at energies of up to 300 keV per charge unit without any mass limitations. The CSR consists of a cryogenic ({proportional_to}5 K) beam pipe surrounded by two radiation shields (40 and 80 K) in a large outer, thermal insulation vacuum. Extreme vacuum (density {proportional_to}10{sup 3} cm{sup -3}) will be achieved by 2 K cryopumping as demonstrated in a prototype ion beam trap. The ion optics was completely assembled within the precision cryogenic mounting and shielding structure of the first corner. There, cooldown tests to {proportional_to}40 K were performed which confirmed the required sub-millimeter accuracy of the specially designed electrode positioning under large temperature changes. The high-voltage connections to the cryogenic electrodes were installed and breakdown tests will be reported. Based on the test results the beam pipe, electrode mounting and shielding structures are under final construction for mounting during 2012.

Development of a Marine Propeller With Nonplanar Lifting Surfaces

DEFF Research Database (Denmark)

Andersen, Poul; Friesch, Jürgen; Kappel, Jens J.

2005-01-01

The principle of non-planar lifting surfaces is applied to the design of modern aircraft wings to obtain better lift to drag ratios. Whereas a pronounced fin or winglet at the wingtip has been developed for aircraft, the application of the nonplanar principle to marine propellers, dealt...... with in this paper, has led to the KAPPEL propeller with blades curved toward the suction side integrating the fin or winglet into the propeller blade. The combined theoretical, experimental, and practical approach to develop and design marine propellers with nonplanar lifting surfaces has resulted in propellers...

Changing of ballistic parameters from aged gun propellants

NARCIS (Netherlands)

Klerk, W.P.C. de; Driel, C.A. van

2003-01-01

The various properties of an SB and a DB gun propellant were investigated before and after artificial ageing. It was found that the decrease of nitrocellulose (NC) molecular weight, due to ageing of gun propellants, leads to a decrease of the mechanical integrity of the propellant grains. The effect

Process simulations for the LCLS-II cryogenic systems

Science.gov (United States)

Ravindranath, V.; Bai, H.; Heloin, V.; Fauve, E.; Pflueckhahn, D.; Peterson, T.; Arenius, D.; Bevins, M.; Scanlon, C.; Than, R.; Hays, G.; Ross, M.

2017-12-01

Linac Coherent Light Source II (LCLS-II), a 4 GeV continuous-wave (CW) superconducting electron linear accelerator, is to be constructed in the existing two mile Linac facility at the SLAC National Accelerator Laboratory. The first light from the new facility is scheduled to be in 2020. The LCLS-II Linac consists of thirty-five 1.3 GHz and two 3.9 GHz superconducting cryomodules. The Linac cryomodules require cryogenic cooling for the super-conducting niobium cavities at 2.0 K, low temperature thermal intercept at 5.5-7.5 K, and a thermal shield at 35-55 K. The equivalent 4.5 K refrigeration capacity needed for the Linac operations range from a minimum of 11 kW to a maximum of 24 kW. Two cryogenic plants with 18 kW of equivalent 4.5 K refrigeration capacity will be used for supporting the Linac cryogenic cooling requirements. The cryogenic plants are based on the Jefferson Lab’s CHL-II cryogenic plant design which uses the “Floating Pressure” design to support a wide variation in the cooling load. In this paper, the cryogenic process for the integrated LCLS-II cryogenic system and the process simulation for a 4.5 K cryoplant in combination with a 2 K cold compressor box, and the Linac cryomodules are described.

Laser-propelled ram accelerator

Energy Technology Data Exchange (ETDEWEB)

Sasoh, A. [Tohoku Univ., Sendai (Japan). Inst. of Fluid Science

2000-11-01

The concept of 'laser-propelled ram accelerator (L-RAMAC)' is proposed. Theoretically it is capable of achieving a higher launch speed than that by a chemical ram accelerator because a higher specific energy can be input to the propellant gas. The laser beam is supplied through the muzzle, focused as an annulus behind the base of the projectile. The performance of L-RAMAC is analized based on generalized Rankine-Hugoniot relations, suggesting that a superorbital muzzle speed is achievable out of this device. (orig.)

Global adiposity and thickness of intraperitoneal and mesenteric adipose tissue depots are increased in women with polycystic ovary syndrome (PCOS).

Science.gov (United States)

Borruel, Susana; Fernández-Durán, Elena; Alpañés, Macarena; Martí, David; Alvarez-Blasco, Francisco; Luque-Ramírez, Manuel; Escobar-Morreale, Héctor F

2013-03-01

Sexual dimorphism suggests a role for androgens in body fat distribution. Women with polycystic ovary syndrome (PCOS), a mainly androgen excess disorder, often present with abdominal obesity and visceral adiposity. We hypothesized that women with PCOS have a masculinized body fat distribution favoring the deposition of fat in visceral and organ-specific adipose tissue depots. This was a case-control study. The study was conducted at an academic hospital. Women with PCOS (n = 55), women without androgen excess (n = 25), and men (n = 26) presenting with similar body mass index participated in the study. There were no interventions. Ultrasound measurements of adipose tissue depots including sc (minimum and maximum), preperitoneal, ip, mesenteric, epicardial, and perirenal fat thickness were obtained and total body fat mass was estimated using a body fat monitor. Men and patients with PCOS had increased amounts of total body fat compared with control women. Men had increased thickness of intraabdominal adipose tissue depots compared with the control women, with the women with PCOS showing intermediate values that were also higher than those of control women in the case of ip and mesenteric fat thickness and was close to reaching statistical significance in the case of epicardial fat thickness. Women with PCOS also showed increased minimum sc fat thickness compared with the control women. Obesity increased the thickness of all of the adipose tissue depots in the 3 groups of subjects. Women with PCOS have higher global adiposity and increased amounts of visceral adipose tissue compared with control women, especially in the ip and mesenteric depots.

Propeller installation effects on turboprop aircraft acoustics

Science.gov (United States)

Chirico, Giulia; Barakos, George N.; Bown, Nicholas

2018-06-01

Propeller installation options for a twin-engined turboprop aircraft are evaluated at cruise conditions, aiming to identify the quieter configuration. Computational fluid dynamics is used to investigate the near-field acoustics and transfer functions are employed to estimate the interior cabin noise. Co-rotating and counter-rotating installation options are compared. The effect of propeller synchrophasing is also considered. The employed method captures the complexity of the acoustic field generated by the interactions of the propeller sound fields among each other and with the airframe, showing also the importance of simulating the whole problem to predict the actual noise on a flying aircraft. Marked differences among the various layouts are observed. The counter-rotating top-in option appears the best in terms of acoustics, the top-out propeller rotation leading to louder noise because of inflow conditions and the occurrence of constructive acoustic interferences. Synchrophasing is shown to be beneficial for co-rotating propellers, specially regarding the interior noise, because of favorable effects in the interaction between the propeller direct sound field and the noise due to the airframe. An angle closer to the maximum relative blade shift was found to be the best choice, yielding, however, higher sound levels than those provided by the counter-rotating top-in layout.

The evolution of cryogenic safety at Fermilab

International Nuclear Information System (INIS)

Stanek, R.; Kilmer, J.

1992-12-01

Over the past twenty-five years, Fermilab has been involved in cryogenic technology as it relates to pursuing experimentation in high energy physics. The Laboratory has instituted a strong cryogenic safety program and has maintained a very positive safety record. The solid commitment of management and the cryogenic community to incorporating safety into the system life cycle has led to policies that set requirements and help establish consistency for the purchase and installation of equipment and the safety analysis and documentation

THE PROPELLER AND THE FROG

International Nuclear Information System (INIS)

Pan, Margaret; Chiang, Eugene

2010-01-01

'Propellers' in planetary rings are disturbances in ring material excited by moonlets that open only partial gaps. We describe a new type of co-orbital resonance that can explain the observed non-Keplerian motions of propellers. The resonance is between the moonlet underlying the propeller and co-orbiting ring particles downstream of the moonlet where the gap closes. The moonlet librates within the gap about an equilibrium point established by co-orbiting material and stabilized by the Coriolis force. In the limit of small libration amplitude, the libration period scales linearly with the gap azimuthal width and inversely as the square root of the co-orbital mass. The new resonance recalls but is distinct from conventional horseshoe and tadpole orbits; we call it the 'frog' resonance, after the relevant term in equine hoof anatomy. For a ring surface density and gap geometry appropriate for the propeller Bleriot in Saturn's A ring, our theory predicts a libration period of ∼4 years, similar to the ∼3.7 year period over which Bleriot's orbital longitude is observed to vary. These librations should be subtracted from the longitude data before any inferences about moonlet migration are made.

Energy coefficients for a propeller series

DEFF Research Database (Denmark)

Olsen, Anders Smærup

2004-01-01

The efficiency for a propeller is calculated by energy coefficients. These coefficients are related to four types of losses, i.e. the axial, the rotational, the frictional, and the finite blade number loss, and one gain, i.e. the axial gain. The energy coefficients are derived by use...... of the potential theory with the propeller modelled as an actuator disk. The efficiency based on the energy coefficients is calculated for a propeller series. The results show a good agreement between the efficiency based on the energy coefficients and the efficiency obtained by a vortex-lattice method....

Cryogenic Safety Rules and Guidelines at CERN

CERN Multimedia

CERN. Geneva

2016-01-01

CERN defines and implements a Safety Policy that sets out the general principles governing safety at CERN. As an intergovernmental organisation, CERN further establishes its own Safety Rules as necessary for its proper functioning. In this process, it takes into account the laws and regulation of the Host States (France and Switzerland), EU regulations and directives, as well as international regulations, standards and directives. For the safety of cryogenic equipment, this is primarily covered by the Safety Regulation for Mechanical Equipment and the General Safety Instruction for Cryogenic Equipment. In addition, CERN has also developed Safety Guidelines to support the implementation of these safety rules, covering cryogenic equipment and oxygen deficiency hazard assessment and mitigation. An overview of the cryogenic safety rules and these safety guidelines will be presented.

Solid propellant processing factor in rocket motor design

Science.gov (United States)

1971-01-01

The ways are described by which propellant processing is affected by choices made in designing rocket engines. Tradeoff studies, design proof or scaleup studies, and special design features are presented that are required to obtain high product quality, and optimum processing costs. Processing is considered to include the operational steps involved with the lining and preparation of the motor case for the grain; the procurement of propellant raw materials; and propellant mixing, casting or extrusion, curing, machining, and finishing. The design criteria, recommended practices, and propellant formulations are included.

Artificial immune algorithm for multi-depot vehicle scheduling problems

Science.gov (United States)

Wu, Zhongyi; Wang, Donggen; Xia, Linyuan; Chen, Xiaoling

2008-10-01

In the fast-developing logistics and supply chain management fields, one of the key problems in the decision support system is that how to arrange, for a lot of customers and suppliers, the supplier-to-customer assignment and produce a detailed supply schedule under a set of constraints. Solutions to the multi-depot vehicle scheduling problems (MDVRP) help in solving this problem in case of transportation applications. The objective of the MDVSP is to minimize the total distance covered by all vehicles, which can be considered as delivery costs or time consumption. The MDVSP is one of nondeterministic polynomial-time hard (NP-hard) problem which cannot be solved to optimality within polynomial bounded computational time. Many different approaches have been developed to tackle MDVSP, such as exact algorithm (EA), one-stage approach (OSA), two-phase heuristic method (TPHM), tabu search algorithm (TSA), genetic algorithm (GA) and hierarchical multiplex structure (HIMS). Most of the methods mentioned above are time consuming and have high risk to result in local optimum. In this paper, a new search algorithm is proposed to solve MDVSP based on Artificial Immune Systems (AIS), which are inspirited by vertebrate immune systems. The proposed AIS algorithm is tested with 30 customers and 6 vehicles located in 3 depots. Experimental results show that the artificial immune system algorithm is an effective and efficient method for solving MDVSP problems.

14 CFR 25.907 - Propeller vibration and fatigue.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Propeller vibration and fatigue. 25.907... vibration and fatigue. This section does not apply to fixed-pitch wood propellers of conventional design. (a... propeller to show that failure due to fatigue will be avoided throughout the operational life of the...

14 CFR 23.907 - Propeller vibration and fatigue.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Propeller vibration and fatigue. 23.907... General § 23.907 Propeller vibration and fatigue. This section does not apply to fixed-pitch wood... evaluation of the propeller to show that failure due to fatigue will be avoided throughout the operational...

Commissioning of cryogenic system for China Spallation Neutron Source

Science.gov (United States)

Ye, Bin; He, Chongchao; Li, Na; Ding, Meiying; Wang, Yaqiong; Yu, Zhang; He, Kun

2017-12-01

China Spallation Neutron Source(CSNS) cryogenic system provides supercritical cryogenic hydrogen to neutron moderators, including a helium refrigerator, hydrogen loop and hydrogen safety equipment. The helium refrigerator is provided by Linde with cooling capacity of 2200 W at 20 K. Hydrogen loop system mainly includes cryogenic hydrogen pipes, hydrogen circulator cold-box and accumulator cold-box. Cryogenic hydrogen pump, ortho-para convertor, helium-hydrogen heat-exchanger, hydrogen heater and accumulator are integrated in hydrogen circulation cold-box, and accumulator cold-box. Hydrogen safety equipment includes safety valves, rupture disk, hydrogen sensor, flame detector and other equipment to ensure that cryogenic system in dangerous situations will go down, vents, or takes other measures. The cryogenic system commissioning work includes four steps. First, in order to test the refrigerating capacity of refrigerator, when acceptance testing, refrigerator internal heater was used as thermal load. Second, using simulation load as heat load of moderator, hydrogen loop use helium instead of hydrogen, and cooled down to 20 K, then re-warming and test the leak detection of hydrogen loop system. Third, base on the step 2, using hydrogen as working medium, and optimized the control logic. Forth, cryogenic system with the moderators joint commissioning. Now, cryogenic system is connected with the moderators, and the forth step will be carried out in the near future.

CFD simulation on Kappel propeller with a hull wake field

DEFF Research Database (Denmark)

Shin, Keun Woo; Andersen, Poul; Møller Bering, Rasmus

2013-01-01

Marine propellers are designed not for the open-water operation, but for the operation behind a hull due to the inhomogeneous hull wake and thrust deduction. The adaptation for the hull wake is important for the propulsive efficiency and cavitation risk especially on single-screw ships. CFD...... simulations for a propeller with a hull model have showed acceptable agreement with a model test result in the thrust and torque (Larsson et al. 2010). In the current work, a measured hull wake is applied to the simulation instead of modelling a hull, because the hull geometry is mostly not available...... for propeller designers and the computational effort can be reduced by excluding the hull. The CFD simulation of a propeller flow with a hull wake is verified in order to use CFD as a propeller design tool. A Kappel propeller, which is an innovative tip-modified propeller, is handled. Kappel propellers...

Progress of cryogenic pulsating heat pipes at UW-Madison

Science.gov (United States)

Diego Fonseca, Luis; Mok, Mason; Pfotenhauer, John; Miller, Franklin

2017-12-01

Space agencies continuously require innovative cooling systems that are lightweight, low powered, physically flexible, easily manufactured and, most importantly, exhibit high heat transfer rates. Therefore, Pulsating Heat Pipes (PHPs) are being investigated to provide these requirements. This paper summarizes the current development of cryogenic Pulsating Heat Pipes with single and multiple evaporator sections built and successfully tested at UW-Madison. Recently, a helium based Pulsating Heat Pipe with three evaporator and three condenser sections has been operated at fill ratios between 20 % and 80 % operating temperature range of 2.9 K to 5.19 K, resulting in a maximum effective thermal conductivity up to 50,000 W/m-K. In addition, a nitrogen Pulsating Heat Pipe has been built with three evaporator sections and one condenser section. This PHP achieved a thermal performance between 32,000 W/m-K and 96,000 W/m-K at fill ratio ranging from 50 % to 80 %. Split evaporator sections are very important in order to spread cooling throughout an object of interest with an irregular temperature distribution or where multiple cooling locations are required. Hence this type of configurations is a proof of concept which hasn’t been attempted before and if matured could be applied to cryo-propellant tanks, superconducting magnets and photon detectors.

Randomised controlled single-blind study of conventional versus depot mydriatic drug delivery prior to cataract surgery

Directory of Open Access Journals (Sweden)

Madge Simon

2006-11-01

Full Text Available Abstract Background A prerequisite for safe cataract surgery is an adequately dilated pupil. The authors conducted a trial to assess the efficacy (in terms of pupil diameter of a depot method of pre-operative pupil dilatation, as compared with repeated instillations of drops (which is time-consuming for the nursing staff and uncomfortable for the patient. Methods A prospective randomised masked trial was conducted comprising 130 patients with no significant ocular history undergoing elective clear corneal phacoemulsification. 65 patients had mydriatic drops (Tropicamide 1%, Phenylephrine 2.5%, Diclofenac sodium 0.1% instilled prior to surgery, 65 had a wick soaked in the same drop mixture placed in the inferior fornix. Horizontal pupil diameters were recorded on a millimetre scale immediately prior to surgery. Results There was no significant difference in pupil size between the two groups (p = 0.255, Student's t-test. Conclusion There was no significant difference between the mydriasis obtained with the depot system compared with conventional drop application. Use of a depot mydriatic delivery system appears to be a safe and efficient method of drug delivery. Trial Registration International Standard Randomised Controlled Trial Number Register ISRCTN78047760

EFD and CFD Characterization of a CLT Propeller

Directory of Open Access Journals (Sweden)

Daniele Bertetta

2012-01-01

Full Text Available In the present paper an experimental and numerical analysis of an unconventional CLT propeller is carried out. Two different numerical approaches, a potential panel method and an RANSE solver, are employed. Cavitation tunnel experiments are carried out in order to measure, as usual, thrust, torque, and cavity extension for different propeller working points. Moreover, LDV measurements are performed to have a deep insight into the complex wake behind the propeller and to analyze the dynamics of generated tip vortexes. The numerical/experimental analysis and comparison of results highlight the peculiarities of this kind of propellers, the possibility to increase efficiency and reduce cavitation risk, in order to exploit the design approaches already well proven for conventional propellers also in the case of these unconventional geometries.

Thermal Stabilization of Cryogenic System in Superconducting Cyclotron

International Nuclear Information System (INIS)

Shin, Seung Jae; Kim, Kyung Min; Cho, Hyung Hee; Hong, Bong Hwan; Kang, Joon Sun; Ahn, Dong Hyun

2011-01-01

Radiology has some useful applications for medical purpose. For cancer therapy, the superconducting cyclotron should generate heavy ion beams. It radiates heavy ion beams to cancer patients. In order to make cyclotron system stable, the cryogenic system which makes superconducting state should work constantly. However, radiation heat transfer of cryogenic system should be considered because liquid helium's boiling point is extremely low and there is huge temperature difference between the cryogenic system and ambient temperature. Accordingly, thermal analysis should be carried out. In this paper, the numerical analysis of the cryogenic system in practical superconducting cyclotron show temperature distribution and suggest the number of coolers using ANSYS Workbench program

Experimental study of high-speed counter-rotation propeller on low speed wind range; Dojiku hantengata kosoku propeller no teisokuiki ni okeru fudo jikken

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-03-01

Collaborative research was conducted by National Aerospace Laboratory and Japan Aircraft Development Company in the period of fiscal 1988-1992 into methods for testing aircraft with advanced propeller in low-speed wind tunnel. The propulsion efficiency of the currently available high-bypass turbofan engine is approximately 60% in the vicinity of Mach number 0.85. Propeller-driven aircraft, whose propulsion efficiency is as high as 80% in the low Mach number domain, are scarcely in practical use in the domain of Mach number 0.75 or higher. There are studies reported abroad as well as in Japan for the propeller-driven aircraft to enjoy higher propeller propulsion efficiency even in the vicinity of Mach number 0.8 by modifying the propeller diameter, number of blades, and blade sections, etc. This paper describes the experimental research into the high-speed counter-rotation propeller. A counter-rotation propeller 0.3m in diameter and provided with coaxially arranged 8times2 SR-2 blades is evaluated for pitch angles during the takeoff and landing modes, for thrust characteristics at the pitch angle for the cruising mode, and for propeller backwash and noise. 15 refs., 72 figs., 9 tabs.

Technology of foamed propellants

Energy Technology Data Exchange (ETDEWEB)

Boehnlein-Mauss, Jutta; Kroeber, Hartmut [Fraunhofer Institut fuer Chemische Technologie ICT, Pfinztal (Germany)

2009-06-15

Foamed propellants are based on crystalline explosives bonded in energetic reaction polymers. Due to their porous structures they are distinguished by high burning rates. Energy content and material characteristics can be varied by using different energetic fillers, energetic polymers and porous structures. Foamed charges can be produced easily by the reaction injection moulding process. For the manufacturing of foamed propellants a semi-continuous remote controlled production plant in pilot scale was set up and a modified reaction injection moulding process was applied. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

Cryogenic Safety HSE Seminar | 21 - 23 September 2016

CERN Multimedia

2016-01-01

With the LHC being the world’s largest superconducting installation, it’s not surprising that CERN is a world leader in cryogenic safety. On 21 and 22 September, over 100 experts in cryogenic safety will be coming to CERN to take part in CERN’s first Cryogenic Safety Seminar, which aims to stimulate collaboration and further the state of the art in this increasingly important field.  

Flexible cryogenic conduit

International Nuclear Information System (INIS)

Brindza, P.D.; Wines, R.R.; Takacs, J.J.

1999-01-01

A flexible and relatively low cost cryogenic conduit is described. The flexible cryogenic conduit of the present invention comprises a first inner corrugated tube with single braided serving, a second outer corrugated tube with single braided serving concentric with the inner corrugated tube, and arranged outwardly about the periphery of the inner corrugated tube and between the inner and outer corrugated tubes: a superinsulation layer; a one half lap layer of polyester ribbon; a one half lap layer of copper ribbon; a spirally wound refrigeration tube; a second one half lap layer of copper ribbon; a second one half lap layer of polyester ribbon; a second superinsulation layer; a third one half lap layer of polyester ribbon; and a spirally wound stretchable and compressible filament

Comparison of cryogenic low-pass filters

Science.gov (United States)

Thalmann, M.; Pernau, H.-F.; Strunk, C.; Scheer, E.; Pietsch, T.

2017-11-01

Low-temperature electronic transport measurements with high energy resolution require both effective low-pass filtering of high-frequency input noise and an optimized thermalization of the electronic system of the experiment. In recent years, elaborate filter designs have been developed for cryogenic low-level measurements, driven by the growing interest in fundamental quantum-physical phenomena at energy scales corresponding to temperatures in the few millikelvin regime. However, a single filter concept is often insufficient to thermalize the electronic system to the cryogenic bath and eliminate spurious high frequency noise. Moreover, the available concepts often provide inadequate filtering to operate at temperatures below 10 mK, which are routinely available now in dilution cryogenic systems. Herein we provide a comprehensive analysis of commonly used filter types, introduce a novel compact filter type based on ferrite compounds optimized for the frequency range above 20 GHz, and develop an improved filtering scheme providing adaptable broad-band low-pass characteristic for cryogenic low-level and quantum measurement applications at temperatures down to few millikelvin.

Comparison of cryogenic low-pass filters.

Science.gov (United States)

Thalmann, M; Pernau, H-F; Strunk, C; Scheer, E; Pietsch, T

2017-11-01

Low-temperature electronic transport measurements with high energy resolution require both effective low-pass filtering of high-frequency input noise and an optimized thermalization of the electronic system of the experiment. In recent years, elaborate filter designs have been developed for cryogenic low-level measurements, driven by the growing interest in fundamental quantum-physical phenomena at energy scales corresponding to temperatures in the few millikelvin regime. However, a single filter concept is often insufficient to thermalize the electronic system to the cryogenic bath and eliminate spurious high frequency noise. Moreover, the available concepts often provide inadequate filtering to operate at temperatures below 10 mK, which are routinely available now in dilution cryogenic systems. Herein we provide a comprehensive analysis of commonly used filter types, introduce a novel compact filter type based on ferrite compounds optimized for the frequency range above 20 GHz, and develop an improved filtering scheme providing adaptable broad-band low-pass characteristic for cryogenic low-level and quantum measurement applications at temperatures down to few millikelvin.

Cryogenic target formation using cold gas jets

International Nuclear Information System (INIS)

Hendricks, C.D.

1980-01-01

A method and apparatus using cold gas jets for producing a substantially uniform layer of cryogenic materials on the inner surface of hollow spherical members having one or more layers, such as inertially imploded targets, are described. By vaporizing and quickly refreezing cryogenic materials contained within a hollow spherical member, a uniform layer of the materials is formed on an inner surface of the spherical member. Basically the method involves directing cold gas jets onto a spherical member having one or more layers or shells and containing the cryogenic material, such as a deuterium-tritium (DT) mixture, to freeze the contained material, momentarily heating the spherical member so as to vaporize the contained material, and quickly refreezing the thus vaporized material forming a uniform layer of cryogenic material on an inner surface of the spherical member

Cryogenics system: strategy to achieve nominal performance and reliable operation

CERN Document Server

Bremer, J; Casas, J; Claudet, S; Delikaris, D; Delruelle, N; Ferlin, G; Fluder, C; Perin, A; Perinic, G; Pezzetti, M; Pirotte, O; Tavian, L; Wagner, U

2012-01-01

During the LHC operation in 2010 and 2011, the cryogenic system has achieved an availability level fulfilling the overall requirement. To reach this level, the cryogenic system has profited like many other beam-dependent systems from the reduced beam parameters. Therefore, impacts of some failures occurred during the LHC operation were mitigated by using the overcapacity margin, the existing built-in redundancy in between adjacent sector cryogenic plants and the "cannibalization" of spares on two idle cryogenic plants. These two first years of operation were also crucial to identify the weaknesses of the present cryogenic maintenance plan and new issues like SEUs. After the LS1, nominal beam parameters are expected and the mitigated measures will be less effective or not applicable at all. Consequently, a consolidation plan to improve the MTBF and the MTTR of the LHC cryogenic system is under definition. Concerning shutdown periods, the present cryogenic sectorization imposes some restrictions in the type of ...

Feasibility Study of Cryogenic Cutting Technology by Using a Computer Simulation and Manufacture of Main Components for Cryogenic Cutting System

International Nuclear Information System (INIS)

Kim, Sung Kyun; Lee, Dong Gyu; Lee, Kune Woo; Song, Oh Seop

2009-01-01

Cryogenic cutting technology is one of the most suitable technologies for dismantling nuclear facilities due to the fact that a secondary waste is not generated during the cutting process. In this paper, the feasibility of cryogenic cutting technology was investigated by using a computer simulation. In the computer simulation, a hybrid method combined with the SPH (smoothed particle hydrodynamics) method and the FE (finite element) method was used. And also, a penetration depth equation, for the design of the cryogenic cutting system, was used and the design variables and operation conditions to cut a 10 mm thickness for steel were determined. Finally, the main components of the cryogenic cutting system were manufactures on the basis of the obtained design variables and operation conditions.

The screw propeller

Science.gov (United States)

Larrabee, E. E.

1980-07-01

Marine and air screw propellers are considered in terms of theoretical hydrodynamics as developed by Joukowsky, Prandtl, and Betz. Attention is given to the flow around wings of finite span where spanwise flow exists and where lift and the bound vorticity must all go smoothly to zero at the wing tips. The concept of a trailing vortex sheet made up of infinitesimal line vortexes roughly aligned with the direction of flight is discussed in this regard. Also considered is induced velocity, which tends to convect the sheet downward at every stage in the roll-up process, the vortex theory of propellers and the Betz-Prandtl circulation distribution. The performance of the Gossamer Albatross and of a pedal-driven biplane called the Chrysalis are also discussed.

CEBAF cryogenic system

International Nuclear Information System (INIS)

Brindza, P.; Rode, C.

1986-01-01

The Continuous Electron Beam Accelerator Facility (CEBAF) is a standing wave superconducting linear accelerator with a maximum energy of 4 GeV and 200 μA beam current. The 418 Cornell/CEBAF superconducting niobium accelerating cavities are arranged in two 0.5 GeV linacs with magnetic recirculating arcs at each end. These accelerating cavities are arranged in pairs in a cryounit. The ensemble of four cryounits (8 cavities) together with their end caps makes up a complete cryostat called a cryogenic module. The four cryounit helium vessels are cross connected to each other and share a common cryogen supply, radiation shield and insulating vacuum. The cryogenics system for CEBAF consists of a 5kW central helium refrigerator and a transfer line system to supply 2.2 K 2.8 ATM helium to the cavity cryostats, 40 K helium at 3.5 ATM to the radiation shields and 4.5K helium at 2.8 ATM to the superconducting magnetic spectrometers in the experimental halls. Both the 2.2 K and the 4.5 K helium are expanded by Joule-Thompson (JT) valves in the individual cryostats yielding 2.0 K at .031 ATM and 4.4 K at 1.2 ATM respectively. The Central Helium Refrigerator is located in the center of the CEBAF racetrack with the transfer lines located in the linac tunnels

Thermodynamic properties of cryogenic fluids

CERN Document Server

Leachman, Jacob; Lemmon, Eric; Penoncello, Steven

2017-01-01

This update to a classic reference text provides practising engineers and scientists with accurate thermophysical property data for cryogenic fluids. The equations for fifteen important cryogenic fluids are presented in a basic format, accompanied by pressure-enthalpy and temperature-entropy charts and tables of thermodynamic properties. It begins with a chapter introducing the thermodynamic relations and functional forms for equations of state, and goes on to describe the requirements for thermodynamic property formulations, needed for the complete definition of the thermodynamic properties of a fluid. The core of the book comprises extensive data tables and charts for the most commonly-encountered cryogenic fluids. This new edition sees significant updates to the data presented for air, argon, carbon monoxide, deuterium, ethane, helium, hydrogen, krypton, nitrogen and xenon. The book supports and complements NIST’s REFPROP - an interactive database and tool for the calculation of thermodynamic propertie...

Investigation on utilization of liquid propellant in ballistic range experiments

Energy Technology Data Exchange (ETDEWEB)

Saso, Akihiro; Oba, Shinji; Takayama, Kazuyoshi [Tohoku University, Sendai (Japan)

1999-10-31

Experiments were conducted in a ballistic range using a HAN (hydroxylammonium nitrate)-based liquid monopropellant, LP1846. In a 25-mm-bore single-stage gun, using bulk-loaded propellant of 10 to 35 g, a muzzle speed up to 1.0 km/s was obtained. Time variations of propellant chamber pressures and in-tube projectile velocity profiles were measured. The liquid propellant combustion was initiated accompanying a delay time which was created due to the pyrolysis of the propellant. In order to obtain reliable ballistic range performance, the method of propellant loading was revealed to be critical. Since the burning rate of the liquid propellant is relatively low, the peak acceleration and the muzzle speed strongly depend on the rupture pressure of a diaphragm that was inserted between the launch tube and the propellant chamber. (author)

Burning properties and mechanical integrity of aged gun propellants

NARCIS (Netherlands)

Driel, C.A. van; Klerk, W.P.C. de

2017-01-01

Conventional gun propellants exhibit the phenomenon of nitrocellulose (NC) decomposition. Besides an effect on thermal stability of propellants, decomposition of NC has an effect on the mechanical integrity of the propellant grains. Enhanced grain fracture may lead to unacceptable changes of the

Long-term cryogenic space storage system

Science.gov (United States)

Hopkins, R. A.; Chronic, W. L.

1973-01-01

Discussion of the design, fabrication and testing of a 225-cu ft spherical cryogenic storage system for long-term subcritical applications under zero-g conditions in storing subcritical cryogens for space vehicle propulsion systems. The insulation system design, the analytical methods used, and the correlation between the performance test results and analytical predictions are described. The best available multilayer insulation materials and state-of-the-art thermal protection concepts were applied in the design, providing a boiloff rate of 0.152 lb/hr, or 0.032% per day, and an overall heat flux of 0.066 Btu/sq ft hr based on a 200 sq ft surface area. A six to eighteen month cryogenic storage is provided by this system for space applications.

Designs of pulsed power cryogenic transformers

International Nuclear Information System (INIS)

Singh, S.K.; Heyne, C.J.; Hackowrth, D.T.; Shestak, E.J.; Eckels, P.W.; Rogers, J.D.

1988-01-01

The Westinghouse Electric Corporation has completed designs of three pulsed power cryogenic transformers of three pulsed power cryogenic transformers for the Los Alamos National Laboratory. These transformers will be configured to transfer their stored energy sequentially to an electro-magnetic launcher and form a three-stage power supply. The pulse transformers will act as two winding energy storage solenoids which provide a high current and energy pulse compression by transforming a 50 kA power supply into a megamp level power supply more appropriate for the electromagnetic launcher duty. This system differs from more traditional transformer applications in that significant current levels do not exists simultaneously in the two windings of the pulse transformer. This paper describes the designs of the pulsed power cryogenic transformers

Cryogenics for SMES

International Nuclear Information System (INIS)

McIntosh, G.E.

1981-01-01

A wide-ranging study of superconducting magnetic energy storage (SMES) structural and cryogenic requirements was made. Concepts and computational methods have been developed for all of the major problems in these areas. Design analyses have been made to provide more detailed information on some items and experimental work has been performed to create data bases in the areas of superfluid heat transfer, superfluid dielectric properties, heat transfer from conductors, and in the thermal and mechanical properties of materials at low temperatures. In most cases optimum solutions have not been made because of the developing nature of the overall study but methodology for optimization has been worked out for essentially all SMES cryogenic and structural elements. The selection of 1.8 K cooling and all aluminum systems in bedrock continues to be the best choice

Eradicating hepatitis C virus ameliorates insulin resistance without change in adipose depots.

Science.gov (United States)

Milner, K-L; Jenkins, A B; Trenell, M; Tid-Ang, J; Samocha-Bonet, D; Weltman, M; Xu, A; George, J; Chisholm, D J

2014-05-01

Chronic hepatitis C (CHC) is associated with lipid-related changes and insulin resistance; the latter predicts response to antiviral therapy, liver disease progression and the risk of diabetes. We sought to determine whether insulin sensitivity improves following CHC viral eradication after antiviral therapy and whether this is accompanied by changes in fat depots or adipokine levels. We compared 8 normoglycaemic men with CHC (genotype 1 or 3) before and at least 6 months post viral eradication and 15 hepatitis C antibody negative controls using an intravenous glucose tolerance test and two-step hyperinsulinaemic-euglycaemic clamp with [6,6-(2) H2 ] glucose to assess peripheral and hepatic insulin sensitivity. Magnetic resonance imaging and spectroscopy quantified abdominal fat compartments, liver and intramyocellular lipid. Peripheral insulin sensitivity improved (glucose infusion rate during high-dose insulin increased from 10.1 ± 1.6 to 12 ± 2.1 mg/kg/min/, P = 0.025), with no change in hepatic insulin response following successful viral eradication, without any accompanying change in muscle, liver or abdominal fat depots. There was corresponding improvement in incremental glycaemic response to intravenous glucose (pretreatment: 62.1 ± 8.3 vs post-treatment: 56.1 ± 8.5 mm, P = 0.008). Insulin sensitivity after viral clearance was comparable to matched controls without CHC. Post therapy, liver enzyme levels decreased but, interestingly, levels of glucagon, fatty acid-binding protein and lipocalin-2 remained elevated. Eradication of the hepatitis C virus improves insulin sensitivity without alteration in fat depots, adipokine or glucagon levels, consistent with a direct link of the virus with insulin resistance. © 2013 John Wiley & Sons Ltd.

Experimental Research on Air Propellers III

Science.gov (United States)

Durand, W F; Lesley, E P

1920-01-01

Report presents the results of wind tunnel tests of propellers that examined the influence of the following characteristics: (1) nominal pitch ratio 1.3 combined with a certain number of the more common or standard forms and proportions; (2) driving face slightly rounded or convex; (3) change in the location of the maximum thickness ordinate of the blade section; (4) pushing forward the leading edge of the blade, thus giving a rounded convex surface on the leading side of the driving face. (5) a series of values for the constant "angle of attack" in forming propellers with radially increasing pitch. In accordance with these purposes tests were carried out on 28 propellers.

Cryogenic system for TRISTAN superconducting RF cavity

International Nuclear Information System (INIS)

Hosoyama, K.; Hara, K.; Kabe, A.; Kojima, Yuuji; Ogitsu, T.; Sakamoto, Y.; Kawamura, S.; Ishimaru, Y.

1990-01-01

A cryogenic system consisting of a helium refrigerator (4 kW at 4.4 K) and a liquid helium distribution transfer system for TRISTAN 508 MHz 32 x 5-cell superconducting RF cavities was designed and constructed. After the performance test of the cryogenic system, 16 x 5-cell superconducting RF cavities in 8 cryostats were installed in underground TRISTAN electron-positron collider and connected to the helium refrigerator on the ground level through the transfer line (total length about 330 m) and cooled by liquid helium pool boiling in parallel. The cryogenic system and its operation experience are described. (author)

Heat transfer in heterogeneous propellant combustion systems

International Nuclear Information System (INIS)

Brewster, M.Q.

1992-01-01

This paper reports that heat transfer plays an important role in several critical areas of heterogeneous, solid-propellant combustion systems. These areas include heat feedback to the propellant surface, heat transfer between burning aluminum droplets and their surroundings, heat transfer to internal insulation systems, and heat transfer to aft-end equipment. Gas conduction dominates heat feedback to the propellant surface in conventional ammonium perchlorate (AP) composite propellants, although particle radiative feedback also plays a significant role in combustion of metalized propellants. Particle radiation plays a dominant role in heat transfer to internal insulation, compared with that of convection. However, conduction by impingement of burning aluminum particles, which has not been extensively studied, may also be significant. Radiative heat loss plays an important role in determining the burning rate of molten aluminum particles due to a highly luminous, oxide particle-laden, detached flame envelope. Radiation by aluminum oxide smoke particles also plays a dominant role in heat transfer from the exhaust plume to aft-end equipment. Uncertainties in aluminum oxide particle-size distribution and optical properties still make it difficult to predict radiative plume heat transfer accurately from first principles

Field Demonstration/Validation of Electrolytic Barriers for Energetic Compounds at Pueblo Chemical Depot

Science.gov (United States)

2010-01-01

measuring the intensity of fluorescence at 517 nm using an Ocean Optics USB-2000TM spectrometer and an Ocean OpticsTM custom six-around-one fiber ...Umatilla Army Depot, OR Demilitarization (washout) Basalt Deep (>50 feet) NRC (2005) Installation Action Plan for UAAP March 2001 Hawthorne

A Piezoelectric Cryogenic Heat Switch

Science.gov (United States)

Jahromi, Amir E.; Sullivan, Dan F.

2014-01-01

We have measured the thermal conductance of a mechanical heat switch actuated by a piezoelectric positioner, the PZHS (PieZo electric Heat Switch), at cryogenic temperatures. The thermal conductance of the PZHS was measured between 4 K and 10 K, and on/off conductance ratios greater than 100 were achieved when the positioner applied its maximum force of 8 N. We discuss the advantages of using this system in cryogenic applications, and estimate the ultimate performance of an optimized PZHS.

Cryogenic, Absolute, High Pressure Sensor

Science.gov (United States)

Chapman, John J. (Inventor); Shams. Qamar A. (Inventor); Powers, William T. (Inventor)

2001-01-01

A pressure sensor is provided for cryogenic, high pressure applications. A highly doped silicon piezoresistive pressure sensor is bonded to a silicon substrate in an absolute pressure sensing configuration. The absolute pressure sensor is bonded to an aluminum nitride substrate. Aluminum nitride has appropriate coefficient of thermal expansion for use with highly doped silicon at cryogenic temperatures. A group of sensors, either two sensors on two substrates or four sensors on a single substrate are packaged in a pressure vessel.

Cryogenic High Pressure Sensor Module

Science.gov (United States)

Chapman, John J. (Inventor); Shams, Qamar A. (Inventor); Powers, William T. (Inventor)

1999-01-01

A pressure sensor is provided for cryogenic, high pressure applications. A highly doped silicon piezoresistive pressure sensor is bonded to a silicon substrate in an absolute pressure sensing configuration. The absolute pressure sensor is bonded to an aluminum nitride substrate. Aluminum nitride has appropriate coefficient of thermal expansion for use with highly doped silicon at cryogenic temperatures. A group of sensors, either two sensors on two substrates or four sensors on a single substrate are packaged in a pressure vessel.

Use of PROFIBUS for cryogenic instrumentation at XFEL

Science.gov (United States)

Boeckmann, T.; Bolte, J.; Bozhko, Y.; Clausen, M.; Escherich, K.; Korth, O.; Penning, J.; Rickens, H.; Schnautz, T.; Schoeneburg, B.; Zhirnov, A.

2017-12-01

The European X-ray Free Electron Laser (XFEL) is a research facility and since December 2016 under commissioning at DESY in Hamburg. The XFEL superconducting accelerator is 1.5 km long and contains 96 superconducting accelerator modules. The control system EPICS (Experimental Physics and Industrial Control System) is used to control and operate the XFEL cryogenic system consisting of the XFEL refrigerator, cryogenic distribution systems and the XFEL accelerator. The PROFIBUS fieldbus technology is the key technology of the cryogenic instrumentation and the link to the control system. More than 650 PROFIBUS nodes are implemented in the different parts of the XFEL cryogenic facilities. The presentation will give an overview of PROFIBUS installation in these facilities regarding engineering, possibilities of diagnostics, commissioning and the first operating experience.

Cryogenic high current discharges

International Nuclear Information System (INIS)

Meierovich, B.E.

1994-01-01

Z-pinches formed from frozen deuterium fibers by a rapidly rising current have enhanced stability and high neutron yield. The efforts to understand the enhanced stability and neutron yield on the basis of classical picture of Bennett equilibrium of the current channel has not given satisfactory results. The traditional approach does not take into account the essential difference between the frozen deuterium fiber Z-pinches and the usual Z-pinches such as exploding wires or classical gas-puffed Z-pinches. The very low temperature of the fiber atoms (10 K), together with the rapidly rising current, result in the coexistence of a high current channel with unionized fiber atoms for a substantial period of time. This phenomena lasts during the risetime. This approach takes into account the difference of the breakdown in a dielectric deuterium fiber and the breakdown in a metallic wire. This difference is essential to the understanding of specific features of cryogenic high current discharges. Z-pinches in frozen deuterium fibers should be considered as a qualitatively new phenomenon on the boundary of cryogenic and high current physics. It is a start of a new branch in plasma physics: the physics of cryogenic high current discharges

Cryogenic safety organisation at CERN

CERN Multimedia

CERN. Geneva

2016-01-01

With Safety being a top priority of CERN’s general policy, the Organisation defines and implements a Policy that sets out the general principles governing Safety at CERN. To the end of the attainment of said Safety objectives, the organic units (owners/users of the equipment) are assigned the responsibility for the implementation of the CERN Safety Policy at all levels of the organization, whereas the Health and Safety and Environmental Protection Unit (HSE) has the role of providing assistance for the implementation of the Safety Policy, and a monitoring role related to the implementation of continuous improvement of Safety, compliance with the Safety Rules and the handling of emergency situations. This talk will elaborate on the roles, responsibilities and organisational structure of the different stakeholders within the Organization with regards to Safety, and in particular to cryogenic safety. The roles of actors of particular importance such as the Cryogenic Safety Officers (CSOs) and the Cryogenic Sa...

Cryogenic Fuel Tank Draining Analysis Model

Science.gov (United States)

Greer, Donald

1999-01-01

One of the technological challenges in designing advanced hypersonic aircraft and the next generation of spacecraft is developing reusable flight-weight cryogenic fuel tanks. As an aid in the design and analysis of these cryogenic tanks, a computational fluid dynamics (CFD) model has been developed specifically for the analysis of flow in a cryogenic fuel tank. This model employs the full set of Navier-Stokes equations, except that viscous dissipation is neglected in the energy equation. An explicit finite difference technique in two-dimensional generalized coordinates, approximated to second-order accuracy in both space and time is used. The stiffness resulting from the low Mach number is resolved by using artificial compressibility. The model simulates the transient, two-dimensional draining of a fuel tank cross section. To calculate the slosh wave dynamics the interface between the ullage gas and liquid fuel is modeled as a free surface. Then, experimental data for free convection inside a horizontal cylinder are compared with model results. Finally, cryogenic tank draining calculations are performed with three different wall heat fluxes to demonstrate the effect of wall heat flux on the internal tank flow field.

A word from the DG: A cryogenic success

CERN Multimedia

2007-01-01

The beginning of this month saw the start of a new phase in the LHC project, with its first inauguration, for the LHC cryogenics. This was marked with a symposium in the Globe attended by 178 representatives of the industrial partners and research institutes involved. It also coincided with stable low-temperature operation of the cryogenic plant for sector 7-8, the first sector of the LHC to be cooled down. A look at the LHC web site (http://lhc.web.cern.ch/lhc/) shows this steady operation. The cryogenic system for the LHC is the largest and most complex ever built, involving many large devices on an industrial scale, where reliability is of paramount importance. The LHC’s energy of 7 TeV required a high magnetic field provided by niobium-titanium coils operating at 1.9 K. This is a new temperature regime for large-scale cryogenics, chosen to make use of the excellent heat-transfer properties of helium in its superfluid state. The final design for the LHC cryogenics had to incorporate both newly ordered ...

Development of hydrazinium nitroformate based solid propellants

NARCIS (Netherlands)

Schöyer, H.F.R.; Schnorhk, A.J.; Korting, P.A.O.G.; Lit, P.J. van; Mul, J.M.; Gadiot, G.; Meulenbrugge, J.J.

1995-01-01

The development of new high-performance propellant combinations requires the establishment of safety and handling characteristics and thermodynamic decomposition and explosive properties. This paper addresses the early development phases of a new composite solid propellant based on HNF as oxidizer

Numerical Analysis of Ice Impacts on Azimuth Propeller

Science.gov (United States)

2013-09-01

uniformity as one solid object, though the built-on process is recognized as well. The number of blades for this propeller varies to control cavitation ...Figure 7). The CRP allows the hydrodynamic advantage of regaining lost rotational energy from the first propeller, which is the conventional...it speeds flow through and accelerates it past the propellers. Decelerating duct slows the flow and allows for greatly reduced cavitation and

Cooling pipeline disposing structure for large-scaled cryogenic structure

International Nuclear Information System (INIS)

Takahashi, Hiroyuki.

1996-01-01

The present invention concerns an electromagnetic force supporting structure for superconductive coils. As the size of a cryogenic structure is increased, since it takes much cooling time, temperature difference between cooling pipelines and the cryogenic structure is increased over a wide range, and difference of heat shrinkage is increased to increase thermal stresses. Then, in the cooling pipelines for a large scaled cryogenic structure, the cooling pipelines and the structure are connected by way of a thin metal plate made of a material having a heat conductivity higher than that of the material of the structure by one digit or more, and the thin metal plate is bent. The displacement between the cryogenic structure and the cooling pipelines caused by heat shrinkage is absorbed by the elongation/shrinkage of the bent structure of the thin metal plate, and the thermal stresses due to the displacement is reduced. In addition, the heat of the cryogenic structures is transferred by way of the thin metal plate. Then, the cooling pipelines can be secured to the cryogenic structure such that cooling by heat transfer is enabled by absorbing a great deviation or three dimensional displacement due to the difference of the temperature distribution between the cryogenic structure enlarged in the scale and put into the three dimensional shape, and the cooling pipelines. (N.H.)

Neutron detection with cryogenics and semiconductors

International Nuclear Information System (INIS)

Bell, Zane W.; Carpenter, D.A.; Cristy, S.S.; Lamberti, V.E.; Burger, Arnold; Woodfield, Brian F.; Niedermayr, Thomas; Dragos Hau, I.; Labov, Simon E.; Friedrich, Stephan; Geoffrey West, W.; Pohl, Kenneth R.; Berg, Lodewijk van den

2005-01-01

The common methods of neutron detection are reviewed with special attention paid to the application of cryogenics and semiconductors to the problem. The authors' work with LiF- and boron-based cryogenic instruments is described as well as the use of CdTe and HgI 2 for direct detection of neutrons. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

A constructive heuristic for time-dependent multi-depot vehicle routing problem with time-windows and heterogeneous fleet

Directory of Open Access Journals (Sweden)

Behrouz Afshar-Nadjafi

2017-01-01

Full Text Available In this paper, we consider the time-dependent multi-depot vehicle routing problem. The objective is to minimize the total heterogeneous fleet cost assuming that the travel time between locations depends on the departure time. Also, hard time window constraints for the customers and limitation on maximum number of the vehicles in depots must be satisfied. The problem is formulated as a mixed integer programming model. A constructive heuristic procedure is proposed for the problem. Also, the efficiency of the proposed algorithm is evaluated on 180 test problems. The obtained computational results indicate that the procedure is capable to obtain a satisfying solution.

AN AIRPLANE WITH UNCONVENTIONALLY PLACED PROPELLER POWER UNIT

Directory of Open Access Journals (Sweden)

Jan Červinka

2017-02-01

Full Text Available The significance of the influence of operating propellers on the aircraft aerodynamic characteristics is well-known. Wind tunnel testing of an airplane model with operating propellers is a complex task regarding the required similarity of the full-scale and the model case. Matching sufficient similarity in axial and rotational velocities in the propeller slipstream is the primordial condition for the global aerodynamic similarity of the windtunnel testing. An example of the model power units with related devices is presented. Examples of the wind tunnel testing results illustrate the extent of the propeller influence on aerodynamic characteristics of an aircraft of unconventional configuration with power units positioned at the fuselage afterbody.

Cryogenic fluid management program flight concept definition

Science.gov (United States)

Kroeger, Erich

1987-01-01

The Lewis Research Center's cryogenic fluid management program flight concept definition is presented in viewgraph form. Diagrams are given of the cryogenic fluid management subpallet and its configuration with the Delta launch vehicle. Information is given in outline form on feasibility studies, requirements definition, and flight experiments design.

Green plasticizers for multibase gun propellants (Lecture)

NARCIS (Netherlands)

Schoolderman, C.; Driel, C.A. van; Zebregs, M.

2007-01-01

TNO Defence, Security and Safety has a long history of research on gun propellants. Areas investigated are formulating (new ingredients, optimization), manufacturing, charge design and lifetime assessment [1,2,3,4,5]. In conventional propellants inert plasticizers are used to alter performance,

Small-Scale Shock Testing of Propellants and Ingredients

National Research Council Canada - National Science Library

Dawley, S

2004-01-01

.... The use of small-scale gap testing to evaluate the shock sensitivity of individual propellant ingredients and propellant formulations is a valuable method for experimentally establishing shock...

Effects of superhydrophobic surface on the propeller wake

Science.gov (United States)

Choi, Hongseok; Lee, Jungjin; Park, Hyungmin

2017-11-01

This study investigates the change in propeller wake when the superhydrophobic surface is applied on the propeller blade. The propeller rotates in a quiescent water tank, facing its bottom, with a rotational Reynolds number of 96000. To measure the three-dimensional flow fields, we use stereo PIV and a water prism is installed at the camera-side tank wall. Two cameras are tilted 30 degrees from the normal axis of the tank wall, satisfying schiempflug condition. Superhydrophobic surface is made by coating hydrophobic nanoparticles on the propeller blade. Measurements are done on two vertical planes (at the center of propeller hub and the blade tip), and are ensemble averaged being classified by blade phase of 0 and 90 degrees. Velocity fluctuation, turbulent kinetic energy, and vorticity are evaluated. With superhydrophobic surface, it is found that the turbulence level is significantly (20 - 30 %) reduced with a small penalty (less than 5%) in the streamwise momentum (i.e., thrust) generation. This is because the cone shaped propeller wake gets narrower and organized vortex structures are broken with the superhydrophobic surfaces. More detailed flow analysis will be given. Supported by NRF (NRF-2016R1C1B2012775, NRF-2016M2B2A9A02945068) programs of Korea government.

Cryogenics system: strategy to achieve nominal performance and reliable operation

International Nuclear Information System (INIS)

Bremer, J.; Brodzinski, K.; Casas, J.; Claudet, S.; Delikaris, D.; Delruelle, N.; Ferlin, G.; Fluder, C.; Perin, A.; Perinic, G.; Pezzetti, M.; Pirotte, O.; Tavian, L.; Wagner, U.

2012-01-01

During the LHC operation in 2010 and 2011, the cryogenic system has achieved an availability level fulfilling the overall requirement. To reach this level, the cryogenic system has profited like many other beam-dependent systems from the reduced beam parameters. Therefore, impacts of some failures occurred during the LHC operation were mitigated by using the over-capacity margin, the existing built-in redundancy in between adjacent sector cryogenic plants and the 'cannibalization' of spares on two idle cryogenic plants. These two first years of operation were also crucial to identify the weaknesses of the present cryogenic maintenance plan and new issues like SEUs. After the LS1, nominal beam parameters are expected and the mitigated measures will be less effective or not applicable at all. Consequently, a consolidation plan to improve the MTBF and the MTTR of the LHC cryogenic system is under definition. Concerning shutdown periods, the present cryogenic sectorization imposes some restrictions in the type of interventions (e.g. cryo-magnet removal) which can be done without affecting the operating conditions of the adjacent sector. This creates additional constrains and possible extra down-time in the schedule of the shutdowns including the hardware commissioning. This presentation focuses on the consolidation plan foreseen during the LS1 to improve the performance of the LHC cryogenic system in terms of availability and sectorization. (authors)

An integrative transcriptomic approach to identify depot differences in genes and microRNAs in adipose tissues from high fat fed mice.

Science.gov (United States)

Wijayatunga, Nadeeja N; Pahlavani, Mandana; Kalupahana, Nishan S; Kottapalli, Kameswara Rao; Gunaratne, Preethi H; Coarfa, Cristian; Ramalingam, Latha; Moustaid-Moussa, Naima

2018-02-06

Obesity contributes to metabolic disorders such as diabetes and cardiovascular disease. Characterization of differences between the main adipose tissue depots, white (WAT) [including subcutaneous (SAT) and visceral adipose tissue (VAT)] and brown adipose tissue (BAT) helps to identify their roles in obesity. Thus, we studied depot-specific differences in whole transcriptome and miRNA profiles of SAT, VAT and BAT from high fat diet (HFD/45% of calories from fat) fed mice using RNA sequencing and small RNA-Seq. Using quantitative real-time polymerase chain reaction, we validated depot-specific differences in endoplasmic reticulum (ER) stress related genes and miRNAs using mice fed a HFD vs. low fat diet (LFD/10% of calories from fat). According to the transcriptomic analysis, lipogenesis, adipogenesis, inflammation, endoplasmic reticulum (ER) stress and unfolded protein response (UPR) were higher in VAT compared to BAT, whereas energy expenditure, fatty acid oxidation and oxidative phosphorylation were higher in BAT than in VAT of the HFD fed mice. In contrast to BAT, ER stress marker genes were significantly upregulated in VAT of HFD fed mice than the LFD fed mice. For the first time, we report depot specific differences in ER stress related miRNAs including; downregulation of miR-125b-5p, upregulation miR-143-3p, and miR-222-3p in VAT following HFD and upregulation of miR-30c-2-3p only in BAT following a HFD in mice than the LFD mice. In conclusion, HFD differentially regulates miRNAs and genes in different adipose depots with significant induction of genes related to lipogenesis, adipogenesis, inflammation, ER stress, and UPR in WAT compared to BAT.

Supercritical Fluid Processing of Propellant Polymers

Science.gov (United States)

1991-01-01

of insoluble material present in the polymeric neopentyl glycol azelate (NPGA) binder. Laub (2) summarizes (from Refs 3 & 4) the various polymeric...binders used in composite propellant formulations for DOD missile systems. e.g., these include: polyneopentyl glycol azelate (NPGA) in HAWK. hydroxy...systems. Composite smokeless propellants containing polyethylene glycol (PEG), polyethylene glycol adepate (PEGA) and polycaprolactone are currently under

The fatty acid profile of fat depots from Santa Inês sheep fed spineless cactus (Opuntia ficus-indica Mill.).

Science.gov (United States)

Costa, Roberto G; Almeida, Michelly DA; Cruz, George Rodrigo B; Beltrão Filho, Edvaldo M; Ribeiro, Neila L; Madruga, Marta S; Queiroga, Rita de Cássia Re

2017-10-01

Fat is the tissue that varies most in animals from both a quantitative and distribution perspective. It plays a fundamental biological role as energy storage during food scarcity. Renal, pelvic and internal fat are deposited first. These fats are used to identify fatty acid profiles that may be considered beneficial or unhealthy. The aim of this study is to evaluate the fatty acid profile of fat depots in Santa Inês sheep finished in confinement with spineless cactus in their diets. The treatments included increasing levels of spineless cactus (Opuntia fícus-indica Mill.): T1 = 0%, T2 = 30%, T3 = 50%, and T4 = 70%. The diets significantly affected the adipose depots. The orthogonal contrast between the diet with no cactus (control) and the other diets indicates that the quantity of saturated fatty acids decreased and that the levels of mono-unsaturated and polyunsaturated fatty acids increased in animals fed spineless cactus. The use of spineless cactus in the diets of Santa Inês sheep affects the lipid profile of their fat depots, reducing the quantity of saturated fatty acids and increasing the quantity of mono-unsaturated and polyunsaturated fatty acids. The fatty acid profile of the fat depots indicates that these fats can be used to formulate meat products and add economic and nutritional value to such products, which increases sheep farmers' incomes. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

HMX based enhanced energy LOVA gun propellant

Energy Technology Data Exchange (ETDEWEB)

Sanghavi, R.R. [High Energy Materials Research Laboratory, Pune 411021 (India)]. E-mail: sanghavirr@yahoo.co.uk; Kamale, P.J. [High Energy Materials Research Laboratory, Pune 411021 (India); Shaikh, M.A.R. [High Energy Materials Research Laboratory, Pune 411021 (India); Shelar, S.D. [High Energy Materials Research Laboratory, Pune 411021 (India); Kumar, K. Sunil [High Energy Materials Research Laboratory, Pune 411021 (India); Singh, Amarjit [High Energy Materials Research Laboratory, Pune 411021 (India)

2007-05-08

Efforts to develop gun propellants with low vulnerability have recently been focused on enhancing the energy with a further improvement in its sensitivity characteristics. These propellants not only prevent catastrophic disasters due to unplanned initiation of currently used gun propellants (based on nitrate esters) but also realize enhanced energy levels to increase the muzzle velocity of the projectiles. Now, in order to replace nitroglycerine, which is highly sensitive to friction and impact, nitramines meet the requirements as they offer superior energy due to positive heat of formation, typical stoichiometry with higher decomposition temperatures and also owing to negative oxygen balance are less sensitive than stoichiometrically balanced NG. RDX has been widely reported for use in LOVA propellant. In this paper we have made an effort to present the work on scantily reported nitramine HMX based LOVA gun propellant while incorporating energetic plasticizer glycidyl azide polymer to enhance the energy level. HMX is known to be thermally stable at higher temperature than RDX and also proved to be less vulnerable to small scale shaped charge jet attack as its decomposition temperature is 270 deg. C. HMX also offers improved impulse due to its superior heat of formation (+17 kcal/mol) as compared to RDX (+14 kcal/mol). It has also been reported that a break point will not appear until 35,000 psi for propellant comprising of 5 {mu}m HMX. Since no work has been reported in open literature regarding replacement of RDX by HMX, the present studies were carried out.

Prediction of propeller-induced hull-pressure fluctuations

NARCIS (Netherlands)

Van Wijngaarden, H.C.J.

2011-01-01

The cavitating propeller often forms the primary source of noise and vibration on board ships. The propeller induces hydroacoustic pressure fluctuations due to the passing blades and, more importantly, the dynamic activity of cavities in the propeller’s immediate vicinity. The accurate prediction of

75 FR 12148 - Airworthiness Directives; Ontic Engineering and Manufacturing, Inc. Propeller Governors, Part...

Science.gov (United States)

2010-03-15

... propeller pitch by regulating oil pressure to the propeller pitch change mechanism. Changes in governor oil..., the propeller governor cannot control oil pressure to the propeller pitch control mechanism. This... proposing this AD to prevent loss of propeller pitch control, damage to the propeller governor, and internal...

Safety Extension Study Of Leuprolide Acetate (Lupron Depot) In The Treatment Of Central Precocious Puberty

Science.gov (United States)

2014-01-08

Precocious; Leuprolide Acetate; Luteinizing Hormone (LH); Gonadotrophin-releasing Hormone Agonist (GnRHa); Tanner Staging; Depot Formulation; Suppression of LH; Central Precocious Puberty (CPP); Gonadotrophin-releasing Hormone (GnRH); Lupron; GnRH Analog; Pediatrics Central Precocious Puberty

Sustained Release of Antibiotics from Injectable and Thermally Responsive Polypeptide Depots

OpenAIRE

Adams, Samuel B.; Shamji, Mohammed F.; Nettles, Dana L.; Hwang, Priscilla; Setton, Lori A.

2009-01-01

Biodegradable polymeric scaffolds are of interest for delivering antibiotics to local sites of infection in orthopaedic applications, such as bone and diarthrodial joints. The objective of this study was to develop a biodegradable scaffold with ease of drug loading in aqueous solution, while providing for drug depot delivery via syringe injection. Elastin-like polypeptides (ELPs) were used for this application, biopolymers of repeating pentapeptide sequences that were thermally triggered to u...

Self-propelled oil droplets consuming "fuel" surfactant

DEFF Research Database (Denmark)

Toyota, Taro; Maru, Naoto; Hanczyc, Martin M

2009-01-01

A micrometer-sized oil droplet of 4-octylaniline containing 5 mol % of an amphiphilic catalyst exhibited a self-propelled motion, producing tiny oil droplets, in an aqueous dispersion of an amphiphilic precursor of 4-octylaniline. The tiny droplets on the surface of the self-propelled droplet wer...

MEMS-Based Solid Propellant Rocket Array Thruster

Science.gov (United States)

Tanaka, Shuji; Hosokawa, Ryuichiro; Tokudome, Shin-Ichiro; Hori, Keiichi; Saito, Hirobumi; Watanabe, Masashi; Esashi, Masayoshi

The prototype of a solid propellant rocket array thruster for simple attitude control of a 10 kg class micro-spacecraft was completed and tested. The prototype has 10×10 φ0.8 mm solid propellant micro-rockets arrayed at a pitch of 1.2 mm on a 20×22 mm substrate. To realize such a dense array of micro-rockets, each ignition heater is powered from the backside of the thruster through an electrical feedthrough which passes along a propellant cylinder wall. Boron/potassium nitrate propellant (NAB) is used with/without lead rhodanide/potassium chlorate/nitrocellulose ignition aid (RK). Impulse thrust was measured by a pendulum method in air. Ignition required electric power of at least 3 4 W with RK and 4 6 W without RK. Measured impulse thrusts were from 2×10-5 Ns to 3×10-4 Ns after the calculation of compensation for air dumping.

Nuclear thermal rockets using indigenous Martian propellants

International Nuclear Information System (INIS)

Zubrin, R.M.

1989-01-01

This paper considers a novel concept for a Martian descent and ascent vehicle, called NIMF (for nuclear rocket using indigenous Martian fuel), the propulsion for which will be provided by a nuclear thermal reactor which will heat an indigenous Martian propellant gas to form a high-thrust rocket exhaust. The performance of each of the candidate Martian propellants, which include CO2, H2O, CH4, N2, CO, and Ar, is assessed, and the methods of propellant acquisition are examined. Attention is also given to the issues of chemical compatibility between candidate propellants and reactor fuel and cladding materials, and the potential of winged Mars supersonic aircraft driven by this type of engine. It is shown that, by utilizing the nuclear landing craft in combination with a hydrogen-fueled nuclear thermal interplanetary vehicle and a heavy lift booster, it is possible to achieve a manned Mars mission in one launch. 6 refs

Cryogenic system design for a compact tokamak reactor

International Nuclear Information System (INIS)

Slack, D.S.; Kerns, J.A.; Miller, J.R.

1988-01-01

The International Tokamak Engineering Reactor (ITER) is a program presently underway to design a next-generation tokamak reactor. The cryogenic system for this reactor must meet unusual and new requirements. Unusually high heat loads (100 kW at 4.5 K) must be handled because neutron shielding has been limited to save space in the reactor core. Also, large variations in the cryogenics loads occur over short periods of time because of the pulsed nature of some of the operating scenarios. This paper describes a workable cryogenic system design for a compact tokamak reactor such as ITER. A design analysis is presented dealing with a system that handles transient loads, coil quenches, reactor cool-down and the effect of variations in helium-supply temperatures on the cryogenic stability of the coils. 5 refs., 4 figs., 1 tab

Cryogenic systems for large superconducting accelerators/storage rings

International Nuclear Information System (INIS)

Brown, D.P.

1981-01-01

Particle accelerators and storage rings which utilize superconducting magnets have presented cryogenic system designers, as well as magnet designers, with many new challenges. When such accelerators were first proposed, little operational experience existed to guide the design. Two superconducting accelerators, complete with cryogenic systems, have been designed and are now under construction. These are the Fermilab Doubler Project and the Brookhaven National Laboratory ISABELLE Project. The cryogenic systems which developed at these two laboratories share many common characteristics, especially as compared to earlier cryogenic systems. Because of this commonality, these characteristics can be reasonably taken as also being representative of future systems. There are other areas in which the two systems are dissimilar. In those areas, it is not possible to state which, if either, will be chosen by future designers. Some of the design parameters for the two systems are given

Research of the cold shield in cryogenic liquid storage

Science.gov (United States)

Chen, L. B.; Zheng, J. P.; Wu, X. L.; Cui, C.; Zhou, Y.; Wang, J. J.

2017-12-01

To realize zero boil-off storage of cryogenic liquids, a cryocooler that can achieve a temperature below the boiling point temperature of the cryogenic liquid is generally needed. Taking into account that the efficiency of the cryocooler will be higher at a higher operating temperature, a novel thermal insulation system using a sandwich container filled with cryogenic liquid with a higher boiling point as a cold radiation shield between the cryogenic tank and the vacuum shield in room temperature is proposed to reduce the electricity power consumption. A two-stage cryocooler or two separate cryocoolers are adopted to condense the evaporated gas from the cold shield and the cryogenic tank. The calculation result of a 55 liter liquid hydrogen tank with a liquid nitrogen shield shows that only 14.4 W of electrical power is needed to make all the evaporated gas condensation while 121.7 W will be needed without the liquid nitrogen shield.

Association between individual fat depots and cardio-metabolic traits in normal- and overweight children, adolescents and adults.

Science.gov (United States)

Hübers, M; Geisler, C; Plachta-Danielzik, S; Müller, M J

2017-05-08

To determine age-related associations between fat mass (FM), regional fat depots and cardiometabolic traits in normal- and overweight children, adolescents and adults. Detailed body composition (regional subcutaneous and visceral adipose tissue; SAT, VAT) by whole-body magnetic resonance imaging (MRI), FM and fat-free mass by air-displacement plethysmography, systolic and diastolic blood pressure (SBP, DBP), triglycerides (TG), high-density lipoprotein cholesterol (HDL), plasma glucose and plasma insulin were measured in 433 subjects (BMI: 23.6 (21.0-27.7); 151 children and adolescents, aged 6-18 years, 150 young adults, aged 18-30 years and 132 adults, aged 30-60 years). Data were derived from pooled data of the 'Reference Center for Body Composition' in Kiel, Germany. Insulin resistance was determined by the homeostatic model assessment of insulin resistance (HOMA-IR). Partial correlations and multivariate linear regression analyses were used to evaluate the associations between body composition and cardiometabolic traits. A descriptive approach was used to demonstrate age-dependent differences in associations between body fat depots and insulin resistance, independent of BMI. FM, SAT, and VAT increased from childhood to adulthood with low VAT in children and adolescents. When compared to children, TG was higher in adults. HDL and DBP did not differ between age groups. Insulin resistance was highest in male adolescents and female young adults. Associations between body fat depots and cardiometabolic traits were seen after puberty with no associations in pre- and intrapubertal children. When compared to FM, SAT and VAT had the strongest association with insulin resistance in adults. This association was independent of BMI. Associations between individual body fat depots and most cardiometabolic traits became evident after puberty only. The strongest associations were observed between insulin resistance and abdominal fat in adults. The impact of VAT was independent

Cryogenic cooling system for HTS cable

Energy Technology Data Exchange (ETDEWEB)

Yoshida, Shigeru [Taiyo Nippon Sanso, Tsukuba (Japan)

2017-06-15

Recently, Research and development activity of HTS (High Temperature Superconducting) power application is very progressive worldwide. Especially, HTS cable system and HTSFCL (HTS Fault current limiter) system are proceeding to practical stages. In such system and equipment, cryogenic cooling system, which makes HTS equipment cooled lower than critical temperature, is one of crucial components. In this article, cryogenic cooling system for HTS application, mainly cable, is reviewed. Cryogenic cooling system can be categorized into conduction cooling system and immersion cooling system. In practical HTS power application area, immersion cooling system with sub-cooled liquid nitrogen is preferred. The immersion cooling system is besides grouped into open cycle system and closed cycle system. Turbo-Brayton refrigerator is a key component for closed cycle system. Those two cooling systems are focused in this article. And, each design and component of the cooling system is explained.

Some General Principles in Cryogenic Design, Implementation, and Testing

Science.gov (United States)

Dipirro, Michael James

2015-01-01

Brief Course Description: In 2 hours only the most basic principles of cryogenics can be presented. I will concentrate on the differences between a room temperature thermal analysis and cryogenic thermal analysis, namely temperature dependent properties. I will talk about practical materials for thermal contact and isolation. I will finish by describing the verification process and instrumentation used that is unique to cryogenic (in general less than 100K) systems.

Image based measurement techniques for aircraft propeller flow diagnostics : Propeller slipstream investigations at high-lift conditions and thrust reverse

NARCIS (Netherlands)

Roosenboom, E.W.M.

2011-01-01

The aim of the thesis is to measure the propeller slipstream properties (velocity and vorticity) and to assess the unsteady and instantaneous behavior of the propeller flow field at high disk loadings, zero thrust and thrust reverse using the image based measurement techniques. Along with its

The DFBX cryogenic distribution boxes for the LHC straight sections

International Nuclear Information System (INIS)

Zbasnik, Jon P.; Corradi, Carol A.; Green, Michael A.; Kajiyama, Y.; Knolls, Michael J.; LaMantia, Roberto F.; Rasson, Joseph E.; Reavill, Dulie; Turner, William C.

2002-01-01

The DFBX distribution boxes are designed to connect the LHC cryogenic distribution system to the interaction region quadrupoles [1] and dipoles for the Large Hadron Collider (LHC). The DFBX distribution boxes also have the current leads for the superconducting interaction region magnets and the LHC interaction region correction coils. The DFBX boxes also connect the magnet and cryogenic instrumentation to the CERN data collection system. The DFBX boxes serve as the cryogenic circulation center and the nerve center for four of the LHC straight sections. This report describes primarily the cryogenic function of the DFBXs

Locating Depots for Capacitated Vehicle Routing

DEFF Research Database (Denmark)

Gørtz, Inge Li; Nagarajan, Viswanath

2016-01-01

We study a location-routing problem in the context of capacitated vehicle routing. The input to the k-location capacitated vehicle routing problem (k-LocVRP) consists of a set of demand locations in a metric space and a fleet of k identical vehicles, each of capacity Q. The objective is to locate k...... depots, one for each vehicle, and compute routes for the vehicles so that all demands are satisfied and the total cost is minimized. Our main result is a constant-factor approximation algorithm for k-LocVRP. In obtaining this result, we introduce a common generalization of the k-median and minimum...... spanning tree problems (called k median forest), which might be of independent interest. We give a local-search based (3+ε)-approximation algorithm for k median forest, which leads to a (12+ε)-approximation algorithm for k-LocVRP, for any constant ε>0....

Locating Depots for Capacitated Vehicle Routing

DEFF Research Database (Denmark)

Gørtz, Inge Li; Nagarajan, Viswanath

2016-01-01

depots, one for each vehicle, and compute routes for the vehicles so that all demands are satisfied and the total cost is minimized. Our main result is a constant-factor approximation algorithm for k-LocVRP. In obtaining this result, we introduce a common generalization of the k-median and minimum...... spanning tree problems (called k median forest), which might be of independent interest. We give a local-search based (3+ε)-approximation algorithm for k median forest, which leads to a (12+ε)-approximation algorithm for k-LocVRP, for any constant ε>0.......We study a location-routing problem in the context of capacitated vehicle routing. The input to the k-location capacitated vehicle routing problem (k-LocVRP) consists of a set of demand locations in a metric space and a fleet of k identical vehicles, each of capacity Q. The objective is to locate k...

Cryogen spray cooling: Effects of droplet size and spray density on heat removal.

Science.gov (United States)

Pikkula, B M; Torres, J H; Tunnell, J W; Anvari, B

2001-01-01

Cryogen spray cooling (CSC) is an effective method to reduce or eliminate non-specific injury to the epidermis during laser treatment of various dermatological disorders. In previous CSC investigations, fuel injectors have been used to deliver the cryogen onto the skin surface. The objective of this study was to examine cryogen atomization and heat removal characteristics of various cryogen delivery devices. Various cryogen delivery device types including fuel injectors, atomizers, and a device currently used in clinical settings were investigated. Cryogen mass was measured at the delivery device output orifice. Cryogen droplet size profiling for various cryogen delivery devices was estimated by optically imaging the droplets in flight. Heat removal for various cryogen delivery devices was estimated over a range of spraying distances by temperature measurements in an skin phantom used in conjunction with an inverse heat conduction model. A substantial range of mass outputs were measured for the cryogen delivery devices while heat removal varied by less than a factor of two. Droplet profiling demonstrated differences in droplet size and spray density. Results of this study show that variation in heat removal by different cryogen delivery devices is modest despite the relatively large difference in cryogen mass output and droplet size. A non-linear relationship between heat removal by various devices and droplet size and spray density was observed. Copyright 2001 Wiley-Liss, Inc.

Simulation of ideal-gas flow by nitrogen and other selected gases at cryogenic temperatures. [transonic flow in cryogenic wind tunnels

Science.gov (United States)

Hall, R. M.; Adcock, J. B.

1981-01-01

The real gas behavior of nitrogen, the gas normally used in transonic cryogenic tunnels, is reported for the following flow processes: isentropic expansion, normal shocks, boundary layers, and interactions between shock waves and boundary layers. The only difference in predicted pressure ratio between nitrogen and an ideal gas which may limit the minimum operating temperature of transonic cryogenic wind tunnels occur at total pressures approaching 9 atm and total temperatures 10 K below the corresponding saturation temperature. These pressure differences approach 1 percent for both isentropic expansions and normal shocks. Alternative cryogenic test gases were also analyzed. Differences between air and an ideal diatomic gas are similar in magnitude to those for nitrogen and should present no difficulty. However, differences for helium and hydrogen are over an order of magnitude greater than those for nitrogen or air. It is concluded that helium and cryogenic hydrogen would not approximate the compressible flow of an ideal diatomic gas.

Performance Analysis Rim Driven Propeller as a Propulsor using Open Water Test

OpenAIRE

Agoes Santoso; Irfan Syarif Arief; Anggara Tio Kurniawan

2017-01-01

The use of duct in propeller is one of the breakthrough in the development of the propeller. Ducting not only claimed to be increasing efficiency of the propeller, but also capable to protect the propeller from impact therefore propeller lifespan is longer. From that idea then RDP is created. RDP propeller blade are designed to be fix at their housing called Rim, in the other word, the driving force came from it’s rim. On current RDP blade used is non-conventional blade. This thesis will disc...

Non-destructive testing of rocket propellant quality using -X-ray radiography

International Nuclear Information System (INIS)

Arayaprecha, W.

1979-01-01

Currently, X-rays radiography has been used extensively in various industries. In this thesis, X-rays has been used in the study of compaction of rocket propellant. For a rocket, to gain an accurate guidance result, the propellant used must be mixed and compacted thoroughly. The quality control of the production of propellant sticks must be carefully done. In this study of non-destructive quality testing of rocket propellant, at first the ultrasonic rays was used to test its homogeneity. However, because the density of the propellant was too low, the test equipment could not detect any reflected signals from the propellant being tested. Then the new procedure using X-rays radiography was tried. The variables in the test procedure were voltage, amperage and the focal-film distance. Also different types of films were used. The results of this experiment were then used to construct an exposure chart for testing the homogeneity of the rocket propellant. The advantage of this chart is that a tester can use this table with propellant sticks of different sizes if they have similar density to the density specified in the chart. Also, it is not necessary that the mixture of the testing propellant be the same as the ones used to construct this chart

The contribution of the in-vivo fate of an oil depot to drug absorption

NARCIS (Netherlands)

Kalicharan, R. W.; Oussoren, C; Schot, Peter; Rijk, de, E.; Vromans, H.

2017-01-01

Sustained release of lipophilic compounds can be achieved with oil depots. These parenteral formulations are generally injected in the vastus lateralis and deltoid muscle. It is known that the absorption rate differs between these two muscles. The reason for this is not fully understood. The aim of

Cryogenic Liquid Sample Acquisition System for Remote Space Applications

Science.gov (United States)

Mahaffy, Paul; Trainer, Melissa; Wegel, Don; Hawk, Douglas; Melek, Tony; Johnson, Christopher; Amato, Michael; Galloway, John

2013-01-01

There is a need to acquire autonomously cryogenic hydrocarbon liquid sample from remote planetary locations such as the lakes of Titan for instruments such as mass spectrometers. There are several problems that had to be solved relative to collecting the right amount of cryogenic liquid sample into a warmer spacecraft, such as not allowing the sample to boil off or fractionate too early; controlling the intermediate and final pressures within carefully designed volumes; designing for various particulates and viscosities; designing to thermal, mass, and power-limited spacecraft interfaces; and reducing risk. Prior art inlets for similar instruments in spaceflight were designed primarily for atmospheric gas sampling and are not useful for this front-end application. These cryogenic liquid sample acquisition system designs for remote space applications allow for remote, autonomous, controlled sample collections of a range of challenging cryogenic sample types. The design can control the size of the sample, prevent fractionation, control pressures at various stages, and allow for various liquid sample levels. It is capable of collecting repeated samples autonomously in difficult lowtemperature conditions often found in planetary missions. It is capable of collecting samples for use by instruments from difficult sample types such as cryogenic hydrocarbon (methane, ethane, and propane) mixtures with solid particulates such as found on Titan. The design with a warm actuated valve is compatible with various spacecraft thermal and structural interfaces. The design uses controlled volumes, heaters, inlet and vent tubes, a cryogenic valve seat, inlet screens, temperature and cryogenic liquid sensors, seals, and vents to accomplish its task.

A Simple Method for High-Lift Propeller Conceptual Design

Science.gov (United States)

Patterson, Michael; Borer, Nick; German, Brian

2016-01-01

In this paper, we present a simple method for designing propellers that are placed upstream of the leading edge of a wing in order to augment lift. Because the primary purpose of these "high-lift propellers" is to increase lift rather than produce thrust, these props are best viewed as a form of high-lift device; consequently, they should be designed differently than traditional propellers. We present a theory that describes how these props can be designed to provide a relatively uniform axial velocity increase, which is hypothesized to be advantageous for lift augmentation based on a literature survey. Computational modeling indicates that such propellers can generate the same average induced axial velocity while consuming less power and producing less thrust than conventional propeller designs. For an example problem based on specifications for NASA's Scalable Convergent Electric Propulsion Technology and Operations Research (SCEPTOR) flight demonstrator, a propeller designed with the new method requires approximately 15% less power and produces approximately 11% less thrust than one designed for minimum induced loss. Higher-order modeling and/or wind tunnel testing are needed to verify the predicted performance.

Design of Hybrid Gels Based on Gellan-Cholesterol Derivative and P90G Liposomes for Drug Depot Applications

Directory of Open Access Journals (Sweden)

Nicole Zoratto

2017-05-01

Full Text Available Gels are extensively studied in the drug delivery field because of their potential benefits in therapeutics. Depot gel systems fall in this area, and the interest in their development has been focused on long-lasting, biocompatible, and resorbable delivery devices. The present work describes a new class of hybrid gels that stem from the interaction between liposomes based on P90G phospholipid and the cholesterol derivative of the polysaccharide gellan. The mechanical properties of these gels and the delivery profiles of the anti-inflammatory model drug diclofenac embedded in such systems confirmed the suitability of these hybrid gels as a good candidate for drug depot applications.

The E-3 Test Facility at Stennis Space Center: Research and Development Testing for Cryogenic and Storable Propellant Combustion Systems

Science.gov (United States)

Pazos, John T.; Chandler, Craig A.; Raines, Nickey G.

2009-01-01

This paper will provide the reader a broad overview of the current upgraded capabilities of NASA's John C. Stennis Space Center E-3 Test Facility to perform testing for rocket engine combustion systems and components using liquid and gaseous oxygen, gaseous and liquid methane, gaseous hydrogen, hydrocarbon based fuels, hydrogen peroxide, high pressure water and various inert fluids. Details of propellant system capabilities will be highlighted as well as their application to recent test programs and accomplishments. Data acquisition and control, test monitoring, systems engineering and test processes will be discussed as part of the total capability of E-3 to provide affordable alternatives for subscale to full scale testing for many different requirements in the propulsion community.

Cryogenic systems for the HEB accelerator of the Superconducting Super Collider

International Nuclear Information System (INIS)

Abramovich, S.; Yuecel, A.

1994-07-01

This report discusses the following topics related to the Superconducting Super Collider: Cryogenic system -- general requirements; cryogenic system components; heat load budgets and refrigeration plant capacities; flow and thermal characteristics; process descriptions; cryogenic control instrumentation and value engineering trade-offs

Relationships between rodent white adipose fat pads and human white adipose fat depots

Directory of Open Access Journals (Sweden)

Daniella E. Chusyd

2016-04-01

Full Text Available The objective of this review was to compare and contrast the physiological and metabolic profiles of rodent white adipose fat pads with white adipose fat depots in humans. Human fat distribution and its metabolic consequences have received extensive attention, but much of what has been tested in translational research has relied heavily on rodents. Unfortunately, the validity of using rodent fat pads as a model of human adiposity has received less attention. There is a surprisingly lack of studies demonstrating an analogous relationship between rodent and human adiposity on obesity-related comorbidities. Therefore, we aimed to compare known similarities and disparities in terms of white adipose tissue development and distribution, sexual dimorphism, weight loss, adipokine secretion, and aging. While the literature supports the notion that many similarities exist between rodents and humans, notable differences emerge related to fat deposition and function of white adipose tissue. Thus, further research is warranted to more carefully define the strengths and limitations of rodent white adipose tissue as a model for humans, with a particular emphasis on comparable fat depots, such as mesenteric fat.

Below-Ambient and Cryogenic Thermal Testing

Science.gov (United States)

Fesmire, James E.

2016-01-01

Thermal insulation systems operating in below-ambient temperature conditions are inherently susceptible to moisture intrusion and vapor drive toward the cold side. The subsequent effects may include condensation, icing, cracking, corrosion, and other problems. Methods and apparatus for real-world thermal performance testing of below-ambient systems have been developed based on cryogenic boiloff calorimetry. New ASTM International standards on cryogenic testing and their extension to future standards for below-ambient testing of pipe insulation are reviewed.

Surface tension confined liquid cryogen cooler

Science.gov (United States)

Castles, Stephen H. (Inventor); Schein, Michael E. (Inventor)

1989-01-01

A cryogenic cooler is provided for use in craft such as launch, orbital, and space vehicles subject to substantial vibration, changes in orientation, and weightlessness. The cooler contains a small pore, large free volume, low density material to restrain a cryogen through surface tension effects during launch and zero-g operations and maintains instrumentation within the temperature range of 10 to 140 K. The cooler operation is completely passive, with no inherent vibration or power requirements.

Computer aided design and development of mixed-propeller pumps

International Nuclear Information System (INIS)

Bhaoyal, B.C.

1994-01-01

This paper deals with the design principle of mixed propeller hydraulic aided by CADD software developed by author for generation of the hydraulic profile of the mixed propeller and diffuser geometry. The design methodology for plotting the vane profile of mixed propeller pump has been discussed in detail with special reference to conformal transformation in cylindrical as well as conical plane. (author). 10 refs., 11 figs

Austenitic stainless steels with cryogenic resistance

International Nuclear Information System (INIS)

Tarata, Daniela Florentina

1999-01-01

The most used austenitic stainless steels are alloyed with chromium and nickel and have a reduced carbon content, usually lower than 0.1 % what ensures corresponding properties for processing by plastic deformation at welding, corrosion resistance in aggressive environment and toughness at low temperatures. Steels of this kind alloyed with manganese are also used to reduce the nickel content. By alloying with manganese which is a gammageneous element one ensures the stability of austenites. Being cheaper these steels may be used extensively for components and equipment used in cryogenics field. The best results were obtained with steels of second group, AMnNi, in which the designed chemical composition was achieved, i.e. the partial replacement of nickel by manganese ensured the toughness at cryogenic temperatures. If these steels are supplementary alloyed, their strength properties may increase to the detriment of plasticity and toughness, although the cryogenic character is preserved

Cryogenics for Particle Accelerators and Detectors

CERN Document Server

Lebrun, P; Vandoni, Giovanna; Wagner, U

2002-01-01

Cryogenics has become a key ancillary technology of particle accelerators and detectors, contributing to their sustained development over the last fifty years. Conversely, this development has produced new challenges and markets for cryogenics, resulting in a fruitful symbiotic relation which materialized in significant technology transfer and technical progress. This began with the use of liquid hydrogen and deuterium in the targets and bubble chambers of the 1950s, 1960s and 1970s. It developed more recently with increasing amounts of liquefied noble gases - mainly argon, but also krypton and even today xenon - in calorimeters. In parallel with these applications, the availability of practical type II superconductors from the early 1960s triggered the use of superconductivity in large spectrometer magnets - mostly driven by considerations of energy savings - and the corresponding development of helium cryogenics. It is however the generalized application of superconductivity in particle accelerators - RF ac...

Enhanced propellant performance via environmentally friendly curable surface coating

Directory of Open Access Journals (Sweden)

Thelma Manning

2017-06-01

Full Text Available Surface coating of granular propellants is widely used in a multiplicity of propellants for small, medium and large caliber ammunition. All small caliber ball propellants exhibit burning progressivity due to application of effective deterrent coatings. Large perforated propellant grains have also begun utilizing plasticizing and impregnated deterrent coatings with the purpose of increasing charge weights for greater energy and velocity for the projectile. The deterrent coating and impregnation process utilizes volatile organic compounds (VOCs and hazardous air pollutants (HAPs which results in propellants that need to be forced air dried which impacts air quality. Propellants undergo temperature fluctuations during their life. Diffusion coefficients vary exponentially with variations in temperature. A small temperature increase can induce a faster migration, even over a short period of time, which can lead to large deviations in the concentration. This large concentration change in the ammunition becomes a safety or performance liability. The presence of both polymeric deterrents and nitroglycerin(NG in the nitrocellulose matrix and organic solvents leads to higher diffusion rates. This results in continued emissions of VOCs and HAPs. Conventional polymers tend to partition within the propellant matrix. In other words, localized mixing can occur between the polymer and underlying propellant. This is due to solvent induced softening of the polymer vehicle over the propellant grain. In effect this creates a path where migration can occur. Since nitrate esters, like NG, are relatively small, it can exude to the surface and create a highly unstable and dangerous situation for the warfighter. Curable polymers do not suffer from this partitioning due to “melting” because no VOC solvents are present. They remain surface coated. The small scale characterization testing, such as closed bomb testing, small scale sensitivity, thermal stability, and

Cryogenic system operating experience review for fusion applications

International Nuclear Information System (INIS)

Cadwallader, L.C.

1992-01-01

This report presents a review of cryogenic system operating experiences, from particle accelerator, fusion experiment, space research, and other applications. Safety relevant operating experiences and accident information are discussed. Quantitative order-of-magnitude estimates of cryogenic component failure rates and accident initiating event frequencies are presented for use in risk assessment, reliability, and availability studies. Safety concerns with cryogenic systems are discussed, including ozone formation, effects of spills, and modeling spill behavior. This information should be useful to fusion system designers and safety analysts, such as the team working on the International Thermonuclear Experimental Reactor design

Autonomous Propellant Loading Project

Data.gov (United States)

National Aeronautics and Space Administration — The AES Autonomous Propellant Loading (APL) project consists of three activities. The first is to develop software that will automatically control loading of...

Formative Evaluation of a Sociotechnical System Intervention at an Army Maintenance Depot

Science.gov (United States)

1986-07-01

periodically reassess itself to determine if the balance between the technical and social systems remains adaptive and responsive to the requirements...developed a comprehensive set of recommendations for improving the balance between the social and technical systems of the depot. During 1983, most of...ity and quality of worklife . However, the nature and extent of the impact is highly elusive and resistant to quantification. 1-4 FORMATIVE

Production and Innovative Applications of Cryogenic Solid Pellets

International Nuclear Information System (INIS)

Baylor, L.R.; Combs, S.K.; Fisher, P.W.; Foster, C.A.; Foust, C.R.; Gouge, M.J.; Milora, S.L.

1999-01-01

For over two decades Oak Ridge National Laboratory has been developing cryogenic pellet injectors for fueling hot, magnetic fusion plasmas. Cryogenic solid pellets of all three hydrogen isotopes have been produced in a size range of 1- to 10-mm diameter and accelerated to speeds from <100 to ∼3000 m/s. The pellets have been formed discretely by cryocondensation in gun barrels and also by extrusion of cryogenic solids at mass flow rates up to ∼0.26 g/s and production rates up to ten pellets per second. The pellets traverse the hot plasma in a fraction of a millisecond and continuously ablate, providing fresh hydrogenic fuel to the interior of the plasma. From this initial application, uses of this technology have expanded to include (1) cryogenic xenon drops or solids for use as a debris-less target in a laser plasma source of X-rays for advanced lithography systems, (2) solid argon and carbon dioxide pellets for surface cleaning or decontamination, and (3) methane pellets in a liquid hydrogen bath for use as an innovative moderator of cold neutrons. Methods of production and acceleration/transport of these cryogenic solids will be described, and examples will be given of their use in prototype systems

Verspreiding van zout bij het terugwinnen van zeezand uit een depot in het Haringvliet

NARCIS (Netherlands)

Kranenburg, C.

1991-01-01

Dit rapport geeft een beknopte analyse van de verdunning en verspreiding van zout vanuit een gepland depot voor ontzilt zeezand in het Haringvliet. Beschouwd zijn de initiële menging van het zout bij terugwinnen van het zand, de verspreiding door stroming en turbulentie bij geopende spuisluis, en de

Blade Section Lift Coefficients for Propellers at Extreme Off-Design Conditions

National Research Council Canada - National Science Library

Shen, Young

1997-01-01

The Propeller Force Module (PFM) code developed by Analytical Methods Inc. (AMI) for calculating propeller side forces during maneuvering simulation studies requires inputs of propeller blade sectional lift, drag, and moment data...

MYRRHA cryogenic system study on performances and reliability requirements

International Nuclear Information System (INIS)

Junquera, T.; Chevalier, N.R.; Thermeau, J.P.; Medeiros Romao, L.; Vandeplassche, D.

2015-01-01

A precise evaluation of the cryogenic requirements for accelerator-driven system such as the MYRRHA project has been performed. In particular, operation temperature, thermal losses, and required cryogenic power have been evaluated. A preliminary architecture of the cryogenic system including all its major components, as well as the principles for the cryogenic fluids distribution has been proposed. A detailed study on the reliability aspects has also been initiated. This study is based on the reliability of large cryogenic systems used for accelerators like HERA, LHC or SNS Linac. The requirements to guarantee good cryogenic system availability can be summarised as follows: 1) Mean Time Between Maintenance (MTBM) should be > 8 000 hours; 2) Valves, heat exchangers and turbines are particularly sensitive elements to impurities (dust, oil, gases), improvements are necessary to keep a minimal level in these components; 3) Redundancy studies for all elements containing moving/vibrating parts (turbines, compressors, including their respective bearings and seal shafts) are necessary; 4) Periodic maintenance is mandatory: oil checks, control of screw compressors every 10.000-15.000 hours, vibration surveillance programme, etc; 5) Special control and maintenance of utilities equipment (supply of cooling water, compressed air and electrical supply) is necessary; 6) Periodic vacuum checks to identify leakage appearance such as insulation vacuum of transfer lines and distribution boxes are necessary; 7) Easily exchangeable cold compressors are required

Thermal Decomposition Behaviors and Burning Characteristics of AN/Nitramine-Based Composite Propellant

Science.gov (United States)

Naya, Tomoki; Kohga, Makoto

2015-04-01

Ammonium nitrate (AN) has attracted much attention due to its clean burning nature as an oxidizer. However, an AN-based composite propellant has the disadvantages of low burning rate and poor ignitability. In this study, we added nitramine of cyclotrimethylene trinitramine (RDX) or cyclotetramethylene tetranitramine (HMX) as a high-energy material to AN propellants to overcome these disadvantages. The thermal decomposition and burning rate characteristics of the prepared propellants were examined as the ratio of AN and nitramine was varied. In the thermal decomposition process, AN/RDX propellants showed unique mass loss peaks in the lower temperature range that were not observed for AN or RDX propellants alone. AN and RDX decomposed continuously as an almost single oxidizer in the AN/RDX propellant. In contrast, AN/HMX propellants exhibited thermal decomposition characteristics similar to those of AN and HMX, which decomposed almost separately in the thermal decomposition of the AN/HMX propellant. The ignitability was improved and the burning rate increased by the addition of nitramine for both AN/RDX and AN/HMX propellants. The increased burning rates of AN/RDX propellants were greater than those of AN/HMX. The difference in the thermal decomposition and burning characteristics was caused by the interaction between AN and RDX.

Process for the leaching of AP from propellant

Science.gov (United States)

Shaw, G. C.; Mcintosh, M. J. (Inventor)

1980-01-01

A method for the recovery of ammonium perchlorate from waste solid rocket propellant is described wherein shredded particles of the propellant are leached with an aqueous leach solution containing a low concentration of surface active agent while stirring the suspension.

Sequential cryogen spraying for heat flux control at the skin surface

Science.gov (United States)

Majaron, Boris; Aguilar, Guillermo; Basinger, Brooke; Randeberg, Lise L.; Svaasand, Lars O.; Lavernia, Enrique J.; Nelson, J. Stuart

2001-05-01

Heat transfer rate at the skin-air interface is of critical importance for the benefits of cryogen spray cooling in combination with laser therapy of shallow subsurface skin lesions, such as port-wine stain birthmarks. With some cryogen spray devices, a layer of liquid cryogen builds up on the skin surface during the spurt, which may impair heat transfer across the skin surface due to relatively low thermal conductivity and potentially higher temperature of the liquid cryogen layer as compared to the spray droplets. While the mass flux of cryogen delivery can be adjusted by varying the atomizing nozzle geometry, this may strongly affect other spray properties, such as lateral spread (cone), droplet size, velocity, and temperature distribution. We present here first experiments with sequential cryogen spraying, which may enable accurate mass flux control through variation of spray duty cycle, while minimally affecting other spray characteristics. The observed increase of cooling rate and efficiency at moderate duty cycle levels supports the above described hypothesis of isolating liquid layer, and demonstrates a novel approach to optimization of cryogen spray devices for individual laser dermatological applications.

Locating Depots for Capacitated Vehicle Routing

DEFF Research Database (Denmark)

Gørtz, Inge Li; Nagarajan, Viswanath

2011-01-01

that all demands are satisfied and the total cost is minimized. Our main result is a constant-factor approximation algorithm for k-LocVRP. To achieve this result, we reduce k-LocVRP to the following generalization of k median, which might be of independent interest. Given a metric (V, d), bound k...... median forest, which leads to a (12+E)-approximation algorithm for k-LocVRP, for any constant E > 0. The algorithm for k median forest is t-swap local search, and we prove that it has locality gap 3 + 2 t ; this generalizes the corresponding result for k median [3]. Finally we consider the k median......We study a location-routing problem in the context of capacitated vehicle routing. The input to k-LocVRP is a set of demand locations in a metric space and a fleet of k vehicles each of capacity Q. The objective is to locate k depots, one for each vehicle, and compute routes for the vehicles so...

Propeller TAP flap

DEFF Research Database (Denmark)

Thomsen, Jørn Bo; Bille, Camilla; Wamberg, Peter

2013-01-01

major complications needing additional surgery. One flap was lost due to a vascular problem. Breast reconstruction can be performed by a propeller TAP flap without cutting the descending branch of the thoracodorsal vessels. However, the authors would recommend that a small cuff of muscle is left around...

Structure of Partially Premixed Flames and Advanced Solid Propellants

National Research Council Canada - National Science Library

Branch, Melvyn

1998-01-01

The combustion of solid rocket propellants of advanced energetic materials involves a complex process of decomposition and condensed phase reactions in the solid propellant, gaseous flame reactions...

Implementation of Improved Management Control of Aviation Depot Level Repairable Funds

Science.gov (United States)

1986-12-01

for comparing and testing. Pf ter Drucker states that ". . . control is an ambiguous word. It means the abiliti to direct oneself and one’s work. It...Frequency 50 LIST OF REFERENCES 1. Drucker , Peter F., The Practice of Management , Harper and Brothers Publishers, 1954. 2. Terry, George R., Principles of...NAVAL POSTGRADUATE SCHOOLMonterey, California 0- 6~~VI E1B9 87THESIS I IMPLEMENTATION OF IMPROVED MANAGEMENT CONTROL OF AVIATION DEPOT LEVEL

Study of Hydrogen Pumping through Condensed Argon in Cryogenic pump

International Nuclear Information System (INIS)

Jadeja, K A; Bhatt, S B

2012-01-01

In ultra high vacuum (UHV) range, hydrogen is a dominant residual gas in vacuum chamber. Hydrogen, being light gas, pumping of hydrogen in this vacuum range is limited with widely used UHV pumps, viz. turbo molecular pump and cryogenic pump. Pre condensed argon layers in cryogenic pump create porous structure on the surface of the pump, which traps hydrogen gas at a temperature less than 20° K. Additional argon gas injection in the cryogenic pump, at lowest temperature, generates multiple layers of condensed argon as a porous frost with 10 to 100 A° diameters pores, which increase the pumping capacity of hydrogen gas. This pumping mechanism of hydrogen is more effective, to pump more hydrogen gas in UHV range applicable in accelerator, space simulation etc. and where hydrogen is used as fuel gas like tokamak. For this experiment, the cryogenic pump with a closed loop refrigerator using helium gas is used to produce the minimum cryogenic temperature as ∼ 14° K. In this paper, effect of cryosorption of hydrogen is presented with different levels of argon gas and hydrogen gas in cryogenic pump chamber.

Stereospecific Winding of Polycyclic Aromatic Hydrocarbons into Trinacria Propellers.

Science.gov (United States)

Mosca, Dario; Stopin, Antoine; Wouters, Johan; Demitri, Nicola; Bonifazi, Davide

2017-11-02

The stereospecific trimerization of enantiomerically pure binaphthols with hexakis(bromomethyl)benzene gives access in one step to enantiomerically pure molecular propellers, in which three binaphthyl rings are held together with dioxecine rings. X-ray diffraction analysis revealed that three out the six naphthyl moieties are folded in a (EF) 3 -type arrangement held by three intramolecular C-H⋅⋅⋅π interactions. This slips outward the three remaining naphthyl rings in a blade-like fashion, just like in three-folded propeller components. This peculiar conformation shows striking similarity to the mythological Sicilian symbol of Trinacria, from which the name "trinacria propeller" derives. The propeller conformation is also preserved in chlorinated solutions, as displayed by the presence of a peak at 4.7 ppm typical of an aromatic proton resonance engaged in a C-H⋅⋅⋅π interaction. The denaturation of the propeller-like conformation is obtained at high temperature, corresponding to activation energy for the ring inversion of ca. 18.2 kcal mol -1 . Notably, halide-functionalized molecular propellers exposing I-atoms at the leading and trailing edges could be prepared stereo- and regiospecifically by choosing the relevant iodo-bearing BINOL derivative. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Studies of pellet acceleration with arc discharge heated propellants

International Nuclear Information System (INIS)

Schuresko, D.D.

1985-01-01

An arc discharge has been utilized to heat gaseous propellants in a pneumatic pellet gun. A cylindrical arc chamber is interposed between the propellant inlet valve and the gun breech and fitted with a ceramic insert for generating swirl in the incoming gas stream. The arc is initiated after the propellant valve opens and the breech pressure starts to rise; a typical discharge lasts 300 microseconds with peak currents u to 2 kA at arc voltages ranging from 100 to 400 V. The system is instrumented with piezoelectric pressure transducers at the propellant valve outlet, gun breech, and gun muzzle. The gun has been operated with 4 mm diameter polyurethane foam pellets (density = 0.14 g/cm 3 ), a 40 cm-long barrel, and various gas propellants at pressures exceeding 70 bar. At I/sub arc/ = 1 kA, V/sub arc/ = 200 V, with helium propellant, the arc produces a 2 to 3 fold prompt increase in P/sub breech/ and a delayed increase in P/sub muzzle/; the pellets exit the gun from 0.5 to 1.0 ms earlier than with the gas alone at 40% higher speeds. Comparisons with the so-called ideal gun theory and with full one-dimensional hydrodynamic calculations of the pellet acceleration will be presented

Studies of pellet acceleration with arc discharge heated propellants

International Nuclear Information System (INIS)

Schuresko, D.D.

1986-01-01

An arc discharge has been utilized to heat gaseous propellants in a pneumatic pellet gun. A cylindrical arc chamber is interposed between the propellant inlet valve and the gun breech and fitted with a ceramic insert for generating swirl in the incoming gas stream. The arc is initiated after the propellant valve opens and the breech pressure starts to rise; a typical discharge lasts 300 microseconds with peak currents up to 2 kA at arc voltages ranging from 100-400 V. The system is instrumented with piezoelectric pressure transducers at the propellant valve outlet, gun breech, and gun muzzle. The gun has been operated with 4 mm diameter polyurethane foam pellets (density = 0.14 g/cm 3 ), a 40 cm-long barrel, and various gas propellants at pressures exceeding 70 bar. At I/sub arc/ = 1 kA, V/sub arc/ = 200 V, with helium propellant, the arc produces a 2-3 fold prompt increase in P/sub breech/ and a delayed increase in P/sub muzzle/; the pellets exit the gun from 0.5-1.0 ms earlier than with the gas alone at 40% higher speeds. Comparisons with the so-called ideal gun theory and with full one-dimensional hydrodynamic calculations of the pellet acceleration will be presented

Grain refinement and hardness distribution in cryogenically cooled ferritic stainless steel welds

International Nuclear Information System (INIS)

Amuda, M.O.H.; Mridha, S.

2013-01-01

Highlights: ► Grain refinement was undertaken in AISI 430 FSS welds using cryogenic cooling. ► Flow rates of the cryogenic liquid influenced weld grain structure. ► Cryogenic cooling of welds generates about 45% grain refinement in welds. ► Phase structure of welds is not affected by flow rates of cryogenic liquid. ► Hardness profile in cryogenically cooled and conventional welds is similar. - Abstract: The energy input and heat dissipation dynamics during fusion welding generates coarse grain in the welds resulting in poor mechanical properties. While grain refinement in welds via the control of the energy input is quite common, the influence of heat dissipation on grain morphology and properties is not fully established. This paper characterized cryogenically cooled ferritic stainless steel (FSS) welds in terms of grain structure and hardness distribution along transverse and thickness directions. Cryogenic cooling reduces the weld dimension by more than 30% and provides grain refinement of almost 45% compared to conventional weld. The hardness distribution in the thickness direction gives slightly higher profile because of decreased grain growth caused by faster cooling effects of cryogenic liquid

The Management of Cryogens at CERN

CERN Document Server

Delikaris, D; Passardi, Giorgio; Serio, L; Tavian, L

2005-01-01

CERN is a large user of industrially procured cryogens essentially liquid helium and nitrogen. Recent contracts have been placed by the Organization for the delivery of quantities up to 280 tons of liquid helium over four years and up to 50000 tons of liquid nitrogen over three years. Main users are the very large cryogenic system of the LHC accelerator complex, the physics experiments using superconducting magnets and liquefied gases and all the related test facilities whether industrial or laboratory scale. With the commissioning of LHC, the need of cryogens at CERN will considerably increase and the procurement policy must be adapted accordingly. In this paper, we discuss procurement strategy for liquid helium and nitrogen, including delivery rates, distribution methods and adopted safety standards. Global turnover, on site re-liquefaction capacity, operational consumption, accidental losses, purification means and storage capacity will be described. Finally, the short to medium term evolution of the Orga...

Cryogenic Thermometer Calibration Facility at CERN

CERN Document Server

Balle, C; Thermeau, J P

1998-01-01

A cryogenic thermometer calibration facility has been designed and is being commissioned in preparation for the very stringent requirements on the temperature control of the LHC superconducting magnets. The temperature is traceable in the 1.5 to 30 K range to standards maintained in a national metrological laboratory by using a set of Rhodium-Iron temperature sensors of metrological quality. The calibration facility is designed for calibrating simultaneously 60 industrial cryogenic thermometers in the 1.5 K to 300 K temperature range, a thermometer being a device that includes both a temperature sensor and the wires heat-intercept. The thermometers can be calibrated in good and degraded vacuum or immersed in the surrounding fluid and at different Joule self-heating conditions that match those imposed by signal conditioners used in large cryogenic machinery. The calibration facility can be operated in an automatic mode and all the control and safety routines are handled by a Programmable Logic Controller (PLC)...

Technical presentation: BGM Cryogenic Engineering Limited

CERN Multimedia

Caroline Laignel - FI Department

2006-01-01

13 - 14 June 2006 TECHNICAL PRESENTATION BGM Cryogenic Engineering Limited 09:00 - 18:00, 60-2-016, Main Building. Presentation on BGM: 11:00 - 12:00, 60-2-016, Main Building. BGM Cryogenic Engineering Limited manufactures assemblies, sub-assemblies and machined components for the cryogenic technology sector. The primary markets served include superconducting magnets used in the healthcare sector (eg MRI body scanners), spectroscopy and NMR equipment for numerous R & D and technology applications, high vacuum applications and particle physics research. BGM has specialist assembly capability including stainless steel and aluminium welding, vacuum testing, electromechanical assembly and metal finishing. BGM offers a ‘one stop shop'facility to satisfy any customer requirement. Through our design partner we can offer a full design and modelling service, including 3D modelling and production of 2D drawings on your own borders. We can conduct heat load and force calculations and advise on the best...

Nonlinear Output Feedback Control of Underwater Vehicle Propellers using Advance Speed Feedback

DEFF Research Database (Denmark)

Fossen, T.I.; Blanke, M.

1999-01-01

More accurate propeller shaft speed controllers can be designed by using nonlinear control theory. In this paper, an output feedback controller reconstructing the advance speed (speed of water going into the propeller) from vehicle speed measurements is derived. For this purpose a three-state model...... minimizes thruster losses due to variations in propeller axial inlet flow which is a major problem when applying conventional vehicle-propeller control systems. The proposed controller is simulated for an underwater vehicle equipped with a single propeller. From the simulations it can be concluded...... of propeller shaft speed, forward (surge) speed of the vehicle and axial inlet flow of the propeller is applied. A nonlinear observer in combination with an output feedback integral controller are derived by applying Lyapunov stability theory and exponential stability is proven. The output feedback controller...

Improving Air Force Depot Programming by Linking Resources to Capabilities

Science.gov (United States)

2012-01-01

thank Rick Grisenthwaite at Warner Robins Air Logistics Center, Jamie Jeter at Okla- homa City Air Logistics Center, and Glen Brown at Ogden Air...consistency, we use the term block cycle instead of SCU in our F-16 discussions. 4 8 Im p ro vin g A ir Fo rce D ep o t Pro g ram m in g b y Lin kin...Requirements RAND TR905-B.8 Figure B.9 Depot Purchased Equipment Maintenance Model Output: Projected Aircraft Availability RAND TR905-B.9 A ir cr af t av

CHAWS user`s guide: System description and standard operating procedures, Lexington-Blue Grass Army Depot

Energy Technology Data Exchange (ETDEWEB)

Martins, S.A.; Shinn, J.H. [eds.

1993-05-01

The Chemical Hazard Warning System (CHAWS) is designed to collect meteorological data and to display, in real time, the dispersion of hazardous chemicals that may result from an accidental release. Meteorological sensors have been placed strategically around the Lexington-Blue Grass Army Depot and are used to calculate direction and hazard distance for the release. Based on these data, arrows depicting the release direction and distance traveled are graphically displayed on a computer screen showing a site map of the facility. The objectives of CHAWS are as follows: To determine the trajectory of the center of mass of released material from the measured wind field; to calculate the dispersion of the released material based on the measured lateral turbulence intensity (sigma theta); to determine the height of the mixing zone by measurement of the inversion height and wind profiles up to an altitude of about 1 km at sites that have SODAR units installed; to archive meteorological data for potential use in climatological descriptions for emergency planning; to archive air-quality data for preparation of compliance reports; and to provide access to the data for near real time hazard analysis purposes. CHAWS sites are located at the Pine Bluff Arsenal, Arkansas, Edgewood area of Aberdeen Proving Ground, Maryland, Tooele Depot, Utah, Lexington-Blue Grass Depot, Kentucky, and Johnston Island in the Pacific. The systems vary between sites with different features and various types of hardware. The basic system, however, is the same. Nonetheless, we have tailored the manuals to the equipment found at each site.

Contribution to the study of the electrodeposition of iron-nickel alloys; Contribution a l'etude du depot electrolytique des alliages fer-nickel

Energy Technology Data Exchange (ETDEWEB)

Valignat, J [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1967-12-01

Using a coulometric technique based upon the anodic intentiostatic dissolution, we studied the potentiostatic, deposition of nickel, iron and nickel iron alloys. We have shown that the minimum of the curve I = f (t) (deposition current versus time) is probably due to the transitory blocking of the surface by hydrogen and that the syn-crystallisation of nickel and iron is responsible for the anomalous co-deposition of these two elements. (author) [French] En employant une methode coulometrique par dissolution anodique intensipstatique, nous avons etudie le depot potentiostatique du nickel, du fer et des alliages fer-nickel. Nous avons pu montrer que le minimum de la courbe I = f (t) enregistree au cours du depot est du probablement au blocage momentane de la surface par l'hydrogene et que la syncristallisation du fer et du nickel est responsable de l'anomalie du depot simultane de ces deux elements. (auteur)

An advanced GAP/AN/TAGN propellant : part 2 : stability and storage life

Energy Technology Data Exchange (ETDEWEB)

Judge, M.D. [Bristol Aerospace, Winnipeg, MB (Canada); Badeen, C.M.; Jones, D.E.G. [Natural Resources Canada, Ottawa, ON (Canada). Canadian Explosives Research Laboratory

2007-07-15

An advanced solid propellant was characterized. The propellant was based on a glycidyl azide polymer (GAP) energetic binder with an ammonium nitrate (AN) oxidizer, and contained a significant percentage of triaminoguanidine nitrate (TAGN). Raw ingredient accelerating rate calorimetry (ARC) was performed to determine self-heating rates. Thermal stability and heat flow calorimetry tests were also conducted. Ballistic analyses were conducted to determine the propellant's burn rate. The propellant was designed to produce non-toxic and non-acidic exhaust products. Results of the tests indicated that the propellant is safe for prolonged storage. The study demonstrated that propellant samples can be heated to temperatures up to 175 degrees C for several hours without combustion response. A mass loss of 62 per cent was observed at temperatures between 160 and 230 degrees C. The samples ignited almost immediately after being placed in a pre-heated block at temperatures higher than 175 degrees C. The propellant's burn rate was approximately twice that of standard AN propellants. The propellant will be further evaluated as a candidate for the propulsion of tactical rockets and missiles. 17 refs., 4 tabs., 6 figs.

Chemiluminescence in cryogenic matrices

Science.gov (United States)

Lotnik, S. V.; Kazakov, Valeri P.

1989-04-01

The literature data on chemiluminescence (CL) in cryogenic matrices have been classified and correlated for the first time. The role of studies on phosphorescence and CL at low temperatures in the development of cryochemistry is shown. The features of low-temperature CL in matrices of nitrogen and inert gases (fine structure of spectra, matrix effects) and the data on the mobility and reactivity of atoms and radicals at very low temperatures are examined. The trends in the development of studies on CL in cryogenic matrices, such as the search for systems involving polyatomic molecules and extending the forms of CL reactions, are followed. The reactions of active nitrogen with hydrocarbons that are accompanied by light emission and CL in the oxidation of carbenes at T >= 77 K are examined. The bibliography includes 112 references.

Discovery Of B Ring Propellers In Cassini UVIS, And ISS

Science.gov (United States)

Sremcevic, Miodrag; Stewart, G. R.; Albers, N.; Esposito, L. W.

2012-10-01

We present evidence for the existence of propellers in Saturn's B ring by combining data from Cassini Ultraviolet Imaging Spectrograph (UVIS) and Imaging Science Subsystem (ISS) experiments. We identify two propeller populations: (1) tens of degrees wide propellers in the dense B ring core, and (2) smaller, more A ring like, propellers populating the inner B ring. The prototype of the first population is an object observed at 18 different epochs between 2005 and 2010. The ubiquitous propeller "S" shape is seen both in UVIS occultations as an optical depth depletion and in ISS as a 40 degrees wide bright stripe in unlit geometries and dark in lit geometries. Combining the available Cassini data we infer that the object is a partial gap embedded in the high optical depth region of the B ring. The gap moves at orbital speed consistent with its radial location. From the radial separation of the propeller wings we estimate that the embedded body, which causes the propeller structure, is about 1.5km in size located at a=112,921km. The UVIS occultations indicate an asymmetric propeller "S" shape. Since the object is located at an edge between high and relatively low optical depth, this asymmetry is most likely a consequence of the strong surface mass density gradient. We estimate that there are possibly dozen up to 100 other propeller objects in Saturn's B ring. The location of the discovered body, at an edge of a dense ringlet within the B ring, suggests a novel mechanism for the up to now illusive B ring irregular large-scale structure of alternating high and low optical depth ringlets. We propose that this B ring irregular structure may have its cause in the presence of many embedded bodies that shepherd the individual B ring ringlets.

Status of the Cryogenic System Commissioning at SNS

CERN Document Server

Casagrande, Fabio; Campisi, Isidoro E; Creel, Jonathan; Dixon, Kelly; Ganni, Venkatarao; Gurd, Pamela; Hatfield, Daniel; Howell, Matthew; Knudsen, Peter; Stout, Daniel; Strong, William

2005-01-01

The Spallation Neutron Source (SNS) is under construction at Oak Ridge National Laboratory. The cold section of the Linac consists of 81 superconducting radio frequency cavities cooled to 2.1K by a 2400 Watt cryogenic refrigeration system. The major cryogenic system components include warm helium compressors with associated oil removal and gas management, 4.5K cold box, 7000L liquid helium dewar, 2.1K cold box (consisting of 4 stages of cold compressors), gaseous helium storage, helium purification and gas impurity monitoring system, liquid nitrogen storage and the cryogenic distribution transfer line system. The overall system commissioning strategy and status will be presented.

The LHC cryogenic system and operational experience from the first three years run

International Nuclear Information System (INIS)

Delikaris, Dimitri; Tavian, Laurent

2014-01-01

The LHC (Large Hadron Collider) accelerator helium cryogenic system consists of eight cryogenically independent sectors, each 3.3 km long, all cooled and operated at 1.9 K. The overall, entropy equivalent, installed cryogenic capacity totalizes 144 kW (a) 4.5 K including 19.2 kW (a) 1.8 K with an associated helium inventory of 130 ton. The LHC cryogenic system is considered among the most complex and powerful in the world allowing the cooling down to superfluid helium temperature of 1.9 K. of the accelerators' high field superconducting magnets distributed over the 26.7 km underground ring. The present article describes the LHC cryogenic system and its associated cryogen infrastructure. Operational experience, including cryogen management, acquired from the first three years of LHC operation is finally presented. (author)

Physics of cryogenics an ultralow temperature phenomenon

CERN Document Server

Zohuri, Bahman

2018-01-01

Physics of Cryogenics: An Ultralow Temperature Phenomenon discusses the significant number of advances that have been made during the last few years in a variety of cryocoolers, such as Brayton, Joule-Thomson, Stirling, pulse tube, Gifford-McMahon and magnetic refrigerators. The book reviews various approaches taken to improve reliability, a major driving force for new research areas. The advantages and disadvantages of different cycles are compared, and the latest improvements in each of these cryocoolers is discussed. The book starts with the thermodynamic fundamentals, followed by the definition of cryogenic and the associated science behind low temperature phenomena and properties. This book is an ideal resource for scientists, engineers and graduate and senior undergraduate students who need a better understanding of the science of cryogenics and related thermodynamics.

Cryogenic Insulation Standard Data and Methodologies Project

Science.gov (United States)

Summerfield, Burton; Thompson, Karen; Zeitlin, Nancy; Mullenix, Pamela; Fesmire, James; Swanger, Adam

2015-01-01

Extending some recent developments in the area of technical consensus standards for cryogenic thermal insulation systems, a preliminary Inter-Laboratory Study of foam insulation materials was performed by NASA Kennedy Space Center and LeTourneau University. The initial focus was ambient pressure cryogenic boil off testing using the Cryostat-400 flat-plate instrument. Completion of a test facility at LETU has enabled direct, comparative testing, using identical cryostat instruments and methods, and the production of standard thermal data sets for a number of materials under sub-ambient conditions. The two sets of measurements were analyzed and indicate there is reasonable agreement between the two laboratories. Based on cryogenic boiloff calorimetry, new equipment and methods for testing thermal insulation systems have been successfully developed. These boiloff instruments (or cryostats) include both flat plate and cylindrical models and are applicable to a wide range of different materials under a wide range of test conditions. Test measurements are generally made at large temperature difference (boundary temperatures of 293 K and 78 K are typical) and include the full vacuum pressure range. Results are generally reported in effective thermal conductivity (ke) and mean heat flux (q) through the insulation system. The new cryostat instruments provide an effective and reliable way to characterize the thermal performance of materials under subambient conditions. Proven in through thousands of tests of hundreds of material systems, they have supported a wide range of aerospace, industry, and research projects. Boiloff testing technology is not just for cryogenic testing but is a cost effective, field-representative methodology to test any material or system for applications at sub-ambient temperatures. This technology, when adequately coupled with a technical standards basis, can provide a cost-effective, field-representative methodology to test any material or system

Super-light-weighted HB-Cesic® mirror cryogenic test

Science.gov (United States)

Devilliers, Christophe; Krödel, Matthias R.; Sodnik, Zoran; Robert, Patrick

2017-11-01

Future scientific space missions require ever more demanding large optics that work at cryogenic temperatures. In the frame of a Darwin assessment study conducted under ESA contract by TAS, the need of future very lightweight cryogenic mirrors with superior optical quality has been identified. Such mirrors need to be of size up to 3.5 m in diameter, with a mass of less than 250 kg (i.e. 25 kg/m2) and possess excellent optical quality at cryogenic temperature down to 40 K.

Pharmacodynamic effects of depot-medroxyprogesterone acetate (DMPA) administered to lactating women on their male infants

NARCIS (Netherlands)

Virutamasen, P; Leepipatpaiboon, S; Kriengsinyot, R; Vichaidith, P; Muia, PN; SekaddeKigondu, CB; Mati, JKG; Forest, MG; Dikkeschei, LD; Wolthers, BG; dArcangues, C

Normal postpartum women, who had a spontaneous vaginal delivery of one full-term male infant, free of congenital abnormalities and other diseases, were recruited for this study. Thirteen women received 150 mg depot-medroxyprogesterone acetate (DMPA), intramuscularly on days 42 + 1 and 126 + 1

Cryogenic system for liquid hydrogen polarimeter

International Nuclear Information System (INIS)

Kitami, T.; Chiba, M.; Hirabayashi, H.; Ishii, T.; Kato, S.

1979-01-01

A cryogenic system has been constructed for a liquid hydrogen polarimeter in order to measure polarization of high energy proton at the 1.3 GeV electron synchrotron of Institute for Nuclear Study, University of Tokyo. The system principally consists of a cryogenerator with a cryogenic transfer line, a liquid hydrogen cryostat, and a 14.5 l target container of thin aluminum alloy where liquid hydrogen is served for the experiment. The refrigeration capacity is about 54 W at 20.4 K without a target container. (author)

Tooele Army Depot Revised Final Site-Wide Ecological Risk Assessment. Volume I.

Science.gov (United States)

1998-02-01

which is immediately east of the depot. Properties to the north of TEAD are used primarily for pasture and cultivation , and to the west and south, for...for the TEAD facility, the types of contaminants present, and the ecotoxicological effects that could be expected due to contaminant exposure. This...questions: • Were the analytical detection limits low enough to be ecotoxicologically relevant (i.e., to be protective of ecological receptors with

Propellant selection for ramjets with solid fuel

Energy Technology Data Exchange (ETDEWEB)

Schmucker, R H; Lips, H

1976-03-11

Ramjet propulsion using solid propellant for post-boost acceleration of missiles exhibits several favorable properties, brought about by heterogeneous combustion. A simplified theory for calculating the performance of possible propellants is presented, and they are classified with respect to maximum fuel-specific impulse. The optimal choice of fuel, from a system standpoint, must consider volume constraints, and defines the requirements for motor geometry.

Air propellers and their environmental problems on ACV's

Science.gov (United States)

Soley, D. H.

The development of ACV blade protection against erosion, both on the propeller blade faces and leading edge, is considered. Polyurethane spray coating is now the standard protection applied to all Dowty Rotol propellers, with thicknesses from 0.015-0.020 on aircraft, and up to 0.080 on the ACV. The bolt-on guard reduced leading edge replacement time by 50 percent, and makes possible replacement in all weather conditions. Typical damage and repairs to ACV blades are discussed, and the propeller installation on the LCAC craft being built for the U.S. Navy is addressed.

Numerically-based ducted propeller design using vortex lattice lifting line theory

OpenAIRE

Stubblefield, John M.

2008-01-01

CIVINS (Civilian Institutions) Thesis document This thesis used vortex lattice lifting line theory to model an axisymmetrical-ducted propeller with no gap between the duct and the propeller. The theory required to model the duct and its interaction with the propeller were discussed and implemented in Open-source Propeller Design and Analysis Program (OpenProp). Two routines for determining the optimum circulation distribution were considered, and a method based on calculus of variation...

Advanced technologies available for future solid propellant grains

Energy Technology Data Exchange (ETDEWEB)

Thepenier, J. [SNPE Propulsion, St Medard en Jalles (France); Fonblanc, G. [SNPE Propulsion, Vert le Petit (France). Centre de Recherche de Bouchet

2001-06-01

Significant advances have been made during the last decade in several fields of solid propulsion: the advances have enabled new savings in the motor development phase and in recurring costs, because they help limit the number of prototypes and tests. The purpose of the paper is to describe the improvements achieved by SNPE in solid grain technologies, making these technologies available for new developments in more efficient and reliable future SRMs: new energetic molecules, new solid propellants, new processes for grain manufacturing, quick response grain design tools associated with advanced models for grain performance predictions. Using its expertise in chemical synthesis, SNPE develops new molecules to fit new energetic material requirements. Tests based on new propellant formulations have produced good results in the propellant performance/safety behavior ratio. New processes have been developed simultaneously to reduce the manufacturing costs of the new propellants. In addition, the grain design has been optimized by using the latest generation of predictive theoretical tools supported by a large data bank of experimental parameters resulting from over 30 years' experience in solid propulsion: computer-aided method for the preliminary grain design; advanced models for SRM operating and performance predictions. All these technologies are available for industrial applications in future developments of solid propellant grains. (author)

Radiation Requirements and Testing of Cryogenic Thermometers for the Ilc

Science.gov (United States)

Barnett, T.; Filippov, Yu. P.; Filippova, E. Yu.; Mokhov, N. V.; Nakao, N.; Klebaner, A. L.; Korenev, S. A.; Theilacker, J. C.; Trenikhina, J.; Vaziri, K.

2008-03-01

Large quantity of cryogenic temperature sensors will be used for operation of the International Linear Collider (ILC). Most of them will be subject to high radiation doses during the accelerator lifetime. Understanding of particle energy spectra, accumulated radiation dose in thermometers and its impact on performance are vital in establishing technical specification of cryogenic thermometry for the ILC. Realistic MARS15 computer simulations were performed to understand the ILC radiation environment. Simulation results were used to establish radiation dose requirements for commercially available cryogenic thermometers. Two types of thermometers, Cernox® and TVO, were calibrated prior to irradiation using different technique. The sensors were subjected then to up to 200 kGy electron beam irradiation with kinetic energy of 5 MeV, a representative of the situation at the ILC operation. A post-irradiation behavior of the sensors was studied. The paper describes the MARS15 model, simulation results, cryogenic test set-up, irradiation tests, and cryogenic test results.

Radiation requirements and testing of cryogenic thermometers for the ILC

International Nuclear Information System (INIS)

Barnett, T.; Filippov, Yu.P.; Mokhov, N.V.; Nakao, N.; Klebaner, A.L.; Korenev, S.A.; Theilacker, J.C.; Trenikhina, J.; Vaziri, K.

2007-01-01

Large quantity of cryogenic temperature sensors will be used for operation of the International Linear Collider (ILC). Most of them will be subject to high radiation doses during the accelerator lifetime. Understanding of particle energy spectra, accumulated radiation dose in thermometers and its impact on performance are vital in establishing technical specification of cryogenic thermometry for the ILC. Realistic MARS15 computer simulations were performed to understand the ILC radiation environment. Simulation results were used to establish radiation dose requirements for commercially available cryogenic thermometers. Two types of thermometers, Cernox(reg s ign) and TVO, were calibrated prior to irradiation using different technique. The sensors were subjected then to up to 200 kGy electron beam irradiation with kinetic energy of 5 MeV, a representative of the situation at the ILC operation. A post-irradiation behavior of the sensors was studied. The paper describes the MARS15 model, simulation results, cryogenic test set-up, irradiation tests, and cryogenic test results

Optimizing the Shunting Schedule of Electric Multiple Units Depot Using an Enhanced Particle Swarm Optimization Algorithm

Science.gov (United States)

Jin, Junchen

2016-01-01

The shunting schedule of electric multiple units depot (SSED) is one of the essential plans for high-speed train maintenance activities. This paper presents a 0-1 programming model to address the problem of determining an optimal SSED through automatic computing. The objective of the model is to minimize the number of shunting movements and the constraints include track occupation conflicts, shunting routes conflicts, time durations of maintenance processes, and shunting running time. An enhanced particle swarm optimization (EPSO) algorithm is proposed to solve the optimization problem. Finally, an empirical study from Shanghai South EMU Depot is carried out to illustrate the model and EPSO algorithm. The optimization results indicate that the proposed method is valid for the SSED problem and that the EPSO algorithm outperforms the traditional PSO algorithm on the aspect of optimality. PMID:27436998

Optimizing the Shunting Schedule of Electric Multiple Units Depot Using an Enhanced Particle Swarm Optimization Algorithm

Directory of Open Access Journals (Sweden)

Jiaxi Wang

2016-01-01

Full Text Available The shunting schedule of electric multiple units depot (SSED is one of the essential plans for high-speed train maintenance activities. This paper presents a 0-1 programming model to address the problem of determining an optimal SSED through automatic computing. The objective of the model is to minimize the number of shunting movements and the constraints include track occupation conflicts, shunting routes conflicts, time durations of maintenance processes, and shunting running time. An enhanced particle swarm optimization (EPSO algorithm is proposed to solve the optimization problem. Finally, an empirical study from Shanghai South EMU Depot is carried out to illustrate the model and EPSO algorithm. The optimization results indicate that the proposed method is valid for the SSED problem and that the EPSO algorithm outperforms the traditional PSO algorithm on the aspect of optimality.

Solid-cryogen-stabilized, cable-in-conduit (CIC) superconducting cables

Science.gov (United States)

Voccio, J. P.; Michael, P. C.; Bromberg, L.; Hahn, S.

2015-12-01

This paper considers the use of a solid cryogen as a means to stabilize, both mechanically and thermally, magnesium diboride (MgB2) superconducting strands within a dual-channel cable-in-conduit (CIC) cable for use in AC applications, such as a generator stator winding. The cable consists of two separate channels; the outer channel contains the superconducting strands and is filled with a fluid (liquid or gas) that becomes solid at the device operating temperature. Several options for fluid will be presented, such as liquid nitrogen, hydrocarbons and other chlorofluorocarbons (CFCs) that have a range of melting temperatures and volumetric expansions (from solid at operating temperature to fixed volume at room temperature). Implications for quench protection and conductor stability, enhanced through direct contact with the solid cryogen, which has high heat capacity and thermal conductivity (compared with helium gas), will be presented. Depending on the cryogen, the conductor will be filled initially either with liquid at atmospheric conditions or a gas at high pressure (∼100 atm). After cooldown, the cryogen in the stranded-channel will be solid, essentially locking the strands in place, preventing strand motion and degradation due to mechanical deformation while providing enhanced thermal capacity for stability and protection. The effect of cryogen porosity is also considered. The relatively high heat capacity of solid cryogens at these lower temperatures (compared to gaseous helium) enhances the thermal stability of the winding. During operation, coolant flow through the open inner channel will minimize pressure drop.

Propellant Gelation for Green In-Space Propulsion, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Concerns in recent years about the toxicity and safe handling of the storable class of propellants have led to efforts in greener monopropellants and bi-propellants....

Modeling Propellant Tank Dynamics

Data.gov (United States)

National Aeronautics and Space Administration — The main objective of my work will be to develop accurate models of self-pressurizing propellant tanks for use in designing hybrid rockets. The first key goal is to...

Army Depot Maintenance: More Effective Use of Organic and Contractor Resources

Science.gov (United States)

1990-06-04

terkerrny (PA) RRAD Red River (TX) IBAD Lexingtor).Bluegrass (KY) 3MPUAD Pueblo (CO) 2000 ANAD CCAD TEAD TOAD SAAO LEAD FMD LBAD PUAfl j] Aut)’onzed Onboard...until it is received by the contractor. That problem could be eliminated by redesigning the process. Specifically, the FTA document that notifies the...should revise CCSS to allow the FTM document to generate an image to LCA, the FTA to create a due-in to the contractor, and CCSS to determine the depot

Cryogenics Vision Workshop for High-Temperature Superconducting Electric Power Systems Proceedings

International Nuclear Information System (INIS)

Energetics, Inc.

2000-01-01

The US Department of Energy's Superconductivity Program for Electric Systems sponsored the Cryogenics Vision Workshop, which was held on July 27, 1999 in Washington, D.C. This workshop was held in conjunction with the Program's Annual Peer Review meeting. Of the 175 people attending the peer review meeting, 31 were selected in advance to participate in the Cryogenics Vision Workshops discussions. The participants represented cryogenic equipment manufactures, industrial gas manufacturers and distributors, component suppliers, electric power equipment manufacturers (Superconductivity Partnership Initiative participants), electric utilities, federal agencies, national laboratories, and consulting firms. Critical factors were discussed that need to be considered in describing the successful future commercialization of cryogenic systems. Such systems will enable the widespread deployment of high-temperature superconducting (HTS) electric power equipment. Potential research, development, and demonstration (RD and D) activities and partnership opportunities for advancing suitable cryogenic systems were also discussed. The workshop agenda can be found in the following section of this report. Facilitated sessions were held to discuss the following specific focus topics: identifying Critical Factors that need to be included in a Cryogenics Vision for HTS Electric Power Systems (From the HTS equipment end-user perspective) identifying R and D Needs and Partnership Roles (From the cryogenic industry perspective) The findings of the facilitated Cryogenics Vision Workshop were then presented in a plenary session of the Annual Peer Review Meeting. Approximately 120 attendees participated in the afternoon plenary session. This large group heard summary reports from the workshop session leaders and then held a wrap-up session to discuss the findings, cross-cutting themes, and next steps. These summary reports are presented in this document. The ideas and suggestions raised during

Performance Analysis Rim Driven Propeller as a Propulsor using Open Water Test

Directory of Open Access Journals (Sweden)

Agoes Santoso

2017-12-01

Full Text Available The use of duct in propeller is one of the breakthrough in the development of the propeller. Ducting not only claimed to be increasing efficiency of the propeller, but also capable to protect the propeller from impact therefore propeller lifespan is longer. From that idea then RDP is created. RDP propeller blade are designed to be fix at their housing called Rim, in the other word, the driving force came from it’s rim. On current RDP blade used is non-conventional blade. This thesis will discuss about design analysis of Kaplan Propeller Kaplan Ka-70 that modified on it’s thickness distribution. On this thesis data that is varied is motor load. Simulation using Open Water Test. The result, highest value of KT and KQ occur on 30% motor load and highest efficiency is 18,338% achieved on 260 Rpm.

Ground Operations Demonstration Unit for Liquid Hydrogen Initial Test Results

Science.gov (United States)

Notardonato, W. U.; Johnson, W. L.; Swanger, A. M.; Tomsik, T.

2015-01-01

NASA operations for handling cryogens in ground support equipment have not changed substantially in 50 years, despite major technology advances in the field of cryogenics. NASA loses approximately 50% of the hydrogen purchased because of a continuous heat leak into ground and flight vessels, transient chill down of warm cryogenic equipment, liquid bleeds, and vent losses. NASA Kennedy Space Center (KSC) needs to develop energy-efficient cryogenic ground systems to minimize propellant losses, simplify operations, and reduce cost associated with hydrogen usage. The GODU LH2 project has designed, assembled, and started testing of a prototype storage and distribution system for liquid hydrogen that represents an advanced end-to-end cryogenic propellant system for a ground launch complex. The project has multiple objectives including zero loss storage and transfer, liquefaction of gaseous hydrogen, and densification of liquid hydrogen. The system is unique because it uses an integrated refrigeration and storage system (IRAS) to control the state of the fluid. This paper will present and discuss the results of the initial phase of testing of the GODU LH2 system.

Understanding of empty container movement: A study on a bottleneck at an off-dock depot

Science.gov (United States)

Zain, Rosmaizura Mohd; Rahman, Mohd Nizam Ab; Nopiah, Zulkifli Mohd; Saibani, Nizaroyani

2014-09-01

Port not only function as connections between marine and land transportation but also as core business areas. In a port terminal, available space is limited, but the influx of container is growing. The off-dock depot is one of the key supply chain players that hold empty containers in the inventory. Therefore, this paper aims to identify the main factors of bottlenecks or congestion that hinder the rapid movement of empty containers from the off-dock depot to the customers. Thirty interviews were conducted with individuals who are key players in the container supply chain. The data were analyzed using Atlas.ti software and the analytic hierarchy process to rank the priority factors of bottlenecks. Findings show that several pertinent factors act as barriers to the key players in the container movement in the day-to-day operations. In future studies, strategies to overcome fragmentation in the container supply chain and logistics must be determined.

Synthesis of pure ozone by nanosecond discharge at cryogenic temperatures

International Nuclear Information System (INIS)

Amirov, R.H.; Asinovsky, E.I.; Samoilov, I.S.

1996-01-01

Synthesis of pure ozone by nanosecond discharge at cryogenic temperatures was experimentally examined. The average ozone concentration in the volume of the discharge tube was less at cryogenic temperatures than at room temperatures. The production of condensed ozone have been determined by measuring the ozone concentration when the walls was heated and ozone evaporated. The energy yield of ozone generation at cryogenic temperatures has been calculated. The maximum value was 200 g/kWh

Evaluation of Losses Of Cold Energy of Cryogen Products in The Transport Systems

Science.gov (United States)

Uglanov, Dmitry; Sarmin, Dmitry; Tsapkova, Alexandra; Burdina, Yana

2017-12-01

At present, there are problems of energy saving in various areas of human life and in power complexes of industrial plants. One possible solution to the problem of increasing energy efficiency is the use of liquefied natural gas and its cold energy. Pipelines for fuel or gas supply in cryogen supply systems have different length depending on the mutual position of storage and cryogen consumption devices relatively to a start construction. Cryogen supply and transport systems include a lot of fittings of different assortment. Reservoirs can be installed on different elevation points. To reduce heat inleak and decrease cold energy of cryogen product different kinds of thermal insulation are used. Cryogen pipelines provide required operation conditions of storage and gasifying systems. The aim of the thermal calculation of cryogen transport and supply systems is to define the value of cryogen heat. In this paper it is shown values of cryogen temperature rise due to heat inleaks at cryogen’s transfer along transport systems for ethane, methane, oxygen and nitrogen were calculated. Heat inleaks also due to hydraulic losses were calculated. Specific losses of cold energy of cryogen product for laminar and turbulent flow were calculated. Correspondences of temperature rise, critical pipeline’s length and Reynolds number were defined for nitrogen, argon, methane and oxygen.

Cryogenic treatment of gas

Science.gov (United States)

Bravo, Jose Luis [Houston, TX; Harvey, III, Albert Destrehan; Vinegar, Harold J [Bellaire, TX

2012-04-03

Systems and methods of treating a gas stream are described. A method of treating a gas stream includes cryogenically separating a first gas stream to form a second gas stream and a third stream. The third stream is cryogenically contacted with a carbon dioxide stream to form a fourth and fifth stream. A majority of the second gas stream includes methane and/or molecular hydrogen. A majority of the third stream includes one or more carbon oxides, hydrocarbons having a carbon number of at least 2, one or more sulfur compounds, or mixtures thereof. A majority of the fourth stream includes one or more of the carbon oxides and hydrocarbons having a carbon number of at least 2. A majority of the fifth stream includes hydrocarbons having a carbon number of at least 3 and one or more of the sulfur compounds.

The disposal of low and intermediate-level radioactive wastes: the Elstow Storage Depot

International Nuclear Information System (INIS)

1983-10-01

This document explains the role of NIREX (Nuclear Industry Radioactive Waste Executive) in planning for the safe disposal of low and intermediate-level radioactive wastes and outlines the plans for the investigation and possible development of a new shallow repository at the CEGB's Elstow Storage Depot, Bedfordshire. The site is conveniently located and is situated on a suitable geologic formation, the Oxford Clay. The next step is for NIREX to undertake site investigations and assess in detail the site's suitability. On the basis of this assessment NIREX will either confirm its interest in the site or reject it as unsuitable. If the site proves to be adequate for the development of a shallow repository then NIREX will seek the necessary planning approvals and authorisations for such a development. The development would involve the construction of new buildings and a programme of trench excavation, waste positioning and trench closure. Existing tenants at the Depot will be accommodated as far as possible. The existing road and rail networks would be used for delivering the packaged wastes. In designing and operating any repository the safety of the public and workforce, both now and in the future, will be of paramount importance. (author)

Particle swarm optimization: an alternative in marine propeller optimization?

Science.gov (United States)

Vesting, F.; Bensow, R. E.

2018-01-01

This article deals with improving and evaluating the performance of two evolutionary algorithm approaches for automated engineering design optimization. Here a marine propeller design with constraints on cavitation nuisance is the intended application. For this purpose, the particle swarm optimization (PSO) algorithm is adapted for multi-objective optimization and constraint handling for use in propeller design. Three PSO algorithms are developed and tested for the optimization of four commercial propeller designs for different ship types. The results are evaluated by interrogating the generation medians and the Pareto front development. The same propellers are also optimized utilizing the well established NSGA-II genetic algorithm to provide benchmark results. The authors' PSO algorithms deliver comparable results to NSGA-II, but converge earlier and enhance the solution in terms of constraints violation.

Numerical Prediction of Hydromechanical Behaviour of Controllable Pitch Propeller

Directory of Open Access Journals (Sweden)

Saman Tarbiat

2014-01-01

Full Text Available The research described in this paper was carried out to predict hydrodynamic and frictional forces of controllable pitch propeller (CPP that bring about fretting problems in a blade bearing. The governing equations are Reynolds-averaged Navier-Stokes (RANS and are solved by OpenFOAM solver for hydrodynamic forces behind the ship’s wake. Frictional forces are calculated by practical mechanical formulae. Different advance velocities with constant rotational speed for blades are used to achieve hydrodynamic coefficients in open water and the wake behind the propeller. Results are compared at four different pitches. Detailed numerical results of 3D modelling of the propeller, hydrodynamic characteristics, and probability of the fretting motion in the propeller are presented. Results show that the probability of the fretting movement is related to the pitch.

Numerical study of hub taper angle on podded propeller performance

International Nuclear Information System (INIS)

Islam, M.F.; Veitch, B.; Bose, N.; Liu, P.

2005-01-01

Presently, the majority of podded propulsion systems are of the pulling type, because this type provides better hydrodynamic efficiency than the pushing type. There are several possible explanations for the better overall performance of a puller type podded propulsor. One is related to the difference in hub shape. Puller and pusher propellers have opposite hub taper angles, hence different hub and blade root shape. These differences cause changes in the flow condition and possibly influence the overall performance. The current study focuses on the variation in performance of pusher and puller propellers with the same blade sections, but different hub taper angles. A hyperboloidal low order source doublet steady/unsteady time domain panel method code was modified and used to evaluate effects of hub taper angle on the open water propulsive performance of some fixed pitch screw propellers used in podded propulsion systems. The modified code was first validated against measurements of two model propellers in terms of average propulsive performance and good agreement was found. Major findings include significant effects of hub taper angle on propulsive performance of tapered hub propellers and noticeable effects of hub taper angle on sectional pressure distributions of tapered hub propeller blades. (author)

Heterogeneous propellant internal ballistics: criticism and regeneration

Science.gov (United States)

Glick, R. L.

2011-10-01

Although heterogeneous propellant and its innately nondeterministic, chemically discrete morphology dominates applications, ballisticcharacterization deterministic time-mean burning rate and acoustic admittance measures' absence of explicit, nondeterministic information requires homogeneous propellant with a smooth, uniformly regressing burning surface: inadequate boundary conditions for heterogeneous propellant grained applications. The past age overcame this dichotomy with one-dimensional (1D) models and empirical knowledge from numerous, adequately supported motor developments and supplementary experiments. However, current cost and risk constraints inhibit this approach. Moreover, its fundamental science approach is more sensitive to incomplete boundary condition information (garbage-in still equals garbage-out) and more is expected. This work critiques this situation and sketches a path forward based on enhanced ballistic and motor characterizations in the workplace and approximate model and apparatus developments mentored by CSAR DNS capabilities (or equivalent).

Development of strand burner for solid propellant burning rate studies

International Nuclear Information System (INIS)

Aziz, A; Mamat, R; Ali, W K Wan

2013-01-01

It is well-known that a strand burner is an apparatus that provides burning rate measurements of a solid propellant at an elevated pressure in order to obtain the burning characteristics of a propellant. This paper describes the facilities developed by author that was used in his studies. The burning rate characteristics of solid propellant have be evaluated over five different chamber pressures ranging from 1 atm to 31 atm using a strand burner. The strand burner has a mounting stand that allows the propellant strand to be mounted vertically. The strand was ignited electrically using hot wire, and the burning time was recorded by electronic timer. Wire technique was used to measure the burning rate. Preliminary results from these techniques are presented. This study shows that the strand burner can be used on propellant strands to obtain accurate low pressure burning rate data

Fundamental of cryogenics (for superconducting RF technology)

CERN Document Server

Pierini, Paolo

2013-01-01

This review briefly illustrates a few fundamental concepts of cryogenic engineering, the technological practice that allows reaching and maintaining the low-temperature operating conditions of the superconducting devices needed in particle accelerators. To limit the scope of the task, and not to duplicate coverage of cryogenic engineering concepts particularly relevant to superconducting magnets that can be found in previous CAS editions, the overview presented in this course focuses on superconducting radio-frequency cavities.

Injection dynamics of gelled propellants

Science.gov (United States)

Yoon, Changjin

Gel propellants have been recognized as attractive candidates for future propulsion systems due to the reduced tendency to spill and the energy advantages over solid propellants. One of strong benefits emphasized in gel propellant applications is a throttling capability, but the accurate flow control is more complicated and difficult than with conventional Newtonian propellants because of the unique rheological behaviors of gels. This study is a computational effort directed to enhance understanding of the injector internal flow characteristics for gel propellants under rocket injection conditions. In simulations, the emphasized rheology is a shear-thinning which represents a viscosity decrease with increasing a shear rate. It is described by a generalized Newtonian fluid constitutive equation and Carreau-Yasuda model. Using this rheological model, two injection schemes are considered in the present study: axially-fed and cross-fed injection for single-element and multi-element impinging injectors, respectively. An axisymmetric model is developed to describe the axially-fed injector flows and fully three-dimensional model is utilized to simulate cross-fed injector flows. Under axially-fed injection conditions investigated, three distinct modes, an unsteady, steady, and hydraulic flip mode, are observed and mapped in terms of Reynolds number and orifice design. In an unsteady mode, quasi-periodic oscillations occur near the inlet lip leading mass pulsations and viscosity fluctuations at the orifice exit. This dynamic behavior is characterized using a time-averaged discharge coefficient, oscillation magnitude and frequency by a parametric study with respect to an orifice design, Reynolds number and rheology. As a result, orifice exit flows for gel propellants appear to be significantly influenced by a viscous damping and flow resistance due to a shear thinning behavior and these are observed in each factors considered. Under conditions driven by a manifold crossflow

Propeller efficiency at full scale : measurement system and mathematical model design

NARCIS (Netherlands)

Muntean, T.V.

2012-01-01

What is propeller efficiency at full scale? This question is asked equally by ship operators and by propeller and propulsion system manufacturers. The question reflects the need to measure propeller efficiency at full physical scale and during regular operation of the vessel. The question has a

Green propellant propulsion concepts for space transportation and technology development needs

NARCIS (Netherlands)

Haeseler, D.; Bombelli, V.; Vuillermoz, P.; Lo, R.; Maree, A.G.M.; Caramelli, F.

2004-01-01

A study has been performed under contract from ESA/ESTEC identifying the development needs in Europe in the field of new green propellant utilization. Criteria for green propellants are defined and discussed. Promising propellants are identified together with their rating w.r.t. those criteria, in

Overview of the Long-Baseline Neutrino Facility cryogenic system

CERN Document Server

Montanari, David; Bremer, Johan; Delaney, Michael; Aurelien, Diaz; Doubnik, Roza; Haaf, Kevin; Hentschel, Steve; Norris, Barry; Voirin, Erik

2017-01-01

The Deep Underground Neutrino Experiment (DUNE) collaboration is developing a multi-kiloton Long-Baseline neutrino experiment that will be located one mile underground at the Sanford Underground Research Facility (SURF) in Lead, SD. In the present design, detectors will be located inside four cryostats filled with a total of 68,400 ton of ultrapure liquid argon, at the level of impurities lower than 100 parts per trillion of oxygen equivalent contamination. The Long-Baseline Neutrino Facility (LBNF) is developing the conventional facilities and cryogenics infrastructure supporting this experiment. The cryogenics system is composed of several sub-systems: External/Infrastructure, Proximity, and Internal cryogenics. It will be engineered, manufactured, commissioned, and qualified by an international engineering team. This contribution highlights the main features of the LBNF cryogenic system. It presents its performance, functional requirements and modes of operations. It also details the status of the design, ...

Nanotribological behavior of deep cryogenically treated martensitic stainless steel

Directory of Open Access Journals (Sweden)

Germán Prieto

2017-08-01

Full Text Available Cryogenic treatments are increasingly used to improve the wear resistance of various steel alloys by means of transformation of retained austenite, deformation of virgin martensite and carbide refinement. In this work the nanotribological behavior and mechanical properties at the nano-scale of cryogenically and conventionally treated AISI 420 martensitic stainless steel were evaluated. Conventionally treated specimens were subjected to quenching and annealing, while the deep cryogenically treated samples were quenched, soaked in liquid nitrogen for 2 h and annealed. The elastic–plastic parameters of the materials were assessed by nanoindentation tests under displacement control, while the friction behavior and wear rate were evaluated by a nanoscratch testing methodology that it is used for the first time in steels. It was found that cryogenic treatments increased both hardness and elastic limit of a low-carbon martensitic stainless steel, while its tribological performance was enhanced marginally.

Nanotribological behavior of deep cryogenically treated martensitic stainless steel.

Science.gov (United States)

Prieto, Germán; Bakoglidis, Konstantinos D; Tuckart, Walter R; Broitman, Esteban

2017-01-01

Cryogenic treatments are increasingly used to improve the wear resistance of various steel alloys by means of transformation of retained austenite, deformation of virgin martensite and carbide refinement. In this work the nanotribological behavior and mechanical properties at the nano-scale of cryogenically and conventionally treated AISI 420 martensitic stainless steel were evaluated. Conventionally treated specimens were subjected to quenching and annealing, while the deep cryogenically treated samples were quenched, soaked in liquid nitrogen for 2 h and annealed. The elastic-plastic parameters of the materials were assessed by nanoindentation tests under displacement control, while the friction behavior and wear rate were evaluated by a nanoscratch testing methodology that it is used for the first time in steels. It was found that cryogenic treatments increased both hardness and elastic limit of a low-carbon martensitic stainless steel, while its tribological performance was enhanced marginally.

Effect of cryogenic treatment on distribution of residual stress in case carburized En 353 steel

International Nuclear Information System (INIS)

Bensely, A.; Venkatesh, S.; Mohan Lal, D.; Nagarajan, G.; Rajadurai, A.; Junik, Krzysztof

2008-01-01

The effect of cryogenic treatment on the distribution of residual stress in the case carburized steel (En 353) was studied using X-ray diffraction technique. Two types of cryogenic treatment: shallow cryogenic treatment (193 K) and deep cryogenic treatment (77 K) were adopted, as a supplement to conventional heat treatment. The amount of retained austenite in conventionally heat-treated, shallow cryogenically treated and deep cryogenically treated samples was found to be 28%, 22% and 14%, respectively. The conventionally heat-treated, shallow cryogenically treated and deep cryogenically treated samples in untempered condition had a surface residual stress of -125 MPa, -115 MPa and -235 MPa, respectively. After tempering the conventionally heat-treated, shallow cryogenically treated and deep cryogenically treated samples had a surface residual stress of -150 MPa, -80 MPa and -80 MPa, respectively. A comparative study of the three treatments revealed that there was an increase in the compressive residual stress in steel that was subjected to cryogenic treatment prior to tempering. The experimental investigation revealed that deep cryogenically treated steel when subjected to tempering has undergone a reduction in compressive residual stress. Such stress relieving behaviour was mainly due to the increased precipitation of fine carbides in specimens subjected to DCT with tempering

Financial Reporting Procedures for Defense Distribution Depots - Defense Logistics Agency Business Area of the Defense Business Operations Fund

National Research Council Canada - National Science Library

Young, Shelton

1994-01-01

In our audit of the FY 1993 Financial Statements for the Distribution Depots--Defense Logistics Agency Business Mea of the Defense Business Operations Fund, we evaluated procedures and controls used...

Cryogenic mechanical properties of Al-Cu-Li-Zr alloy 2090

International Nuclear Information System (INIS)

Glazer, J.; Dalder, E.N.C.; Emigh, R.A.; Verzasconi, S.L.; Yu, W.

1986-01-01

The mechanical properties of aluminum-lithium alloy 2090-T8E41 were evaluated at 298 K, 77 K, and 4 K. Previously reported tensile and fracture toughness properties at room temperature were confirmed. This alloy exhibits substantially improved properties at cryogenic temperatures; the strength, elongation, fracture toughness and fatigue crack growth resistance all improve simultaneously as the testing temperature decreases. This alloy has cryogenic properties superior to those of aluminum alloys currently used for cryogenic applications

A review of research in low earth orbit propellant collection

Science.gov (United States)

Singh, Lake A.; Walker, Mitchell L. R.

2015-05-01

This comprehensive review examines the efforts of previous researchers to develop concepts for propellant-collecting spacecraft, estimate the performance of these systems, and understand the physics involved. Rocket propulsion requires the spacecraft to expend two fundamental quantities: energy and propellant mass. A growing number of spacecraft collect the energy they need to execute propulsive maneuvers in-situ with solar panels. In contrast, every spacecraft using rocket propulsion has carried all of the propellant mass needed for the mission from the ground, which limits the range and mission capabilities. Numerous researchers have explored the concept of collecting propellant mass while in space. These concepts have varied in scale and complexity from chemical ramjets to fusion-driven interstellar vessels. Research into propellant-collecting concepts occurred in distinct eras. During the Cold War, concepts tended to be large, complex, and nuclear powered. After the Cold War, concepts transitioned to solar power sources and more effort has been devoted to detailed analysis of specific components of the propellant-collecting architecture. By detailing the major contributions and limitations of previous work, this review concisely presents the state-of-the-art and outlines five areas for continued research. These areas include air-compatible cathode technology, techniques to improve propellant utilization on atmospheric species, in-space compressor and liquefaction technology, improved hypersonic and hyperthermal free molecular flow inlet designs, and improved understanding of how design parameters affect system performance.

Four-quadrant propeller modeling: A low-order harmonic approximation

Digital Repository Service at National Institute of Oceanography (India)

Haeusler, A.J; Saccon, A.; Hauser, J; Pascoal, A.M.; Aguiar, A.P.

. We explore the connection between the propeller thrust, torque, and efficiency curves and the lift and drag curves of the propeller blades. The model originates from a well-known four-quadrant model, based on a sinusoidal approximation...

Cryogenic current leads

Energy Technology Data Exchange (ETDEWEB)

Zizek, F.

1982-01-01

Theoretical, technical and design questions are examined of cryogenic current leads for SP of magnetic systems. Simplified mathematical models are presented for the current leads. To illustrate modeling, the calculation is made of the real current leads for 500 A and three variants of current leads for 1500 A for the enterprise ''Shkoda.''

Reconstruction of pressure sores with perforator-based propeller flaps.

Science.gov (United States)

Jakubietz, Rafael G; Jakubietz, Danni F; Zahn, Robert; Schmidt, Karsten; Meffert, Rainer H; Jakubietz, Michael G

2011-03-01

Perforator flaps have been successfully used for reconstruction of pressure sores. Although V-Y advancement flaps approximate debrided wound edges, perforator-based propeller flaps allow rotation of healthy tissue into the defect. Perforator-based propeller flaps were planned in 13 patients. Seven pressure sores were over the sacrum, five over the ischial tuberosity, and one on the tip of the scapula. Three patients were paraplegic, six were bedridden, and five were ambulatory. In three patients, no perforators were found. In 10 patients, propeller flaps were transferred. In two patients, total flap necrosis occurred, which was reconstructed with local advancement flaps. In two cases, a wound dehiscence occurred and had to be revised. One hematoma required evacuation. No further complications were noted. No recurrence at the flap site occurred. Local perforator flaps allow closure of pressure sores without harvesting muscle. The propeller version has the added benefit of transferring tissue from a distant site, avoiding reapproximation of original wound edges. Twisting of the pedicle may cause torsion and venous obstruction. This can be avoided by dissecting a pedicle of at least 3 cm. Propeller flaps are a safe option for soft tissue reconstruction of pressure sores. © Thieme Medical Publishers.

Calculation of marine propeller static strength based on coupled BEM/FEM

Directory of Open Access Journals (Sweden)

YE Liyu

2017-10-01

Full Text Available [Objectives] The reliability of propeller stress has a great influence on the safe navigation of a ship. To predict propeller stress quickly and accurately,[Methods] a new numerical prediction model is developed by coupling the Boundary Element Method(BEMwith the Finite Element Method (FEM. The low order BEM is used to calculate the hydrodynamic load on the blades, and the Prandtl-Schlichting plate friction resistance formula is used to calculate the viscous load. Next, the calculated hydrodynamic load and viscous correction load are transmitted to the calculation of the Finite Element as surface loads. Considering the particularity of propeller geometry, a continuous contact detection algorithm is developed; an automatic method for generating the finite element mesh is developed for the propeller blade; a code based on the FEM is compiled for predicting blade stress and deformation; the DTRC 4119 propeller model is applied to validate the reliability of the method; and mesh independence is confirmed by comparing the calculated results with different sizes and types of mesh.[Results] The results show that the calculated blade stress and displacement distribution are reliable. This method avoids the process of artificial modeling and finite element mesh generation, and has the advantages of simple program implementation and high calculation efficiency.[Conclusions] The code can be embedded into the code of theoretical and optimized propeller designs, thereby helping to ensure the strength of designed propellers and improve the efficiency of propeller design.

Selected physico-mechanical characteristics of cryogenic and ambient ground turmeric

Science.gov (United States)

Barnwal, Pradyuman; Mohite, Ashish M.; Singh, Krishna K.; Kumar, Pankaj

2014-03-01

In this communication, selected physicomechanical characteristics of ground turmeric (cv. Prabha) were investigated for cryogenic and ambient grinding conditions of turmeric at different moisture contents (4, 6, 8 and 10% w.b.). A cryogenic grinder (Model: 100 UPZ, Hosokawa Alpine, Germany) and a micro pulverizer (hammer mill) were used for cryogenic and ambient grinding, respectively. The ground turmeric was graded in three grades viz. Gr-I, Gr-II and Gr-III with a sieve shaker using BSS Nos. 40, 85 and pan, respectively. Tap densities for cryogenic and ambient ground turmeric decreased from 678.7 (Gr-I) to 546.7 kgm-3 (Gr-III) and from 642.3 (Gr-I) to 468.6 kgm-3 (Gr-III), respectively, with the moisture increase. The angle of repose for cryogenic and ambient ground turmeric increased linearly from 26.85 (Gr-I) to 34.0° (Gr-III) and from 23.10 (Gr-I) to 28.06° (Gr-III), respectively with the increase in moisture content. The static coefficient of friction was the highest on plywood surface followed by mild steel sheet and galvanized iron sheet. The cryoground samples were found better in colour. Thermal conductivity of cryo-ground samples was higher than that of ambient ground samples. These physico-mechanical characteristics of cryogenic and ambient ground turmeric will be helpful for packaging, handling, and storage.

An Analysis of the Factors Generating the Variance Between the Budgeted and Actual Operating Results of the Naval Aviation Depot at North Island, California

Science.gov (United States)

2008-06-01

management structure employs free- market system principles and encourages business-like processes that are mission driven. Since no operating funds are...variable (Potvin, 2007). 2. Unit Cost Goal NWCFs use the unit cost goal ( UCG ) for planning purposes. The UCG is an estimate of what a unit of product...mission 6. Will not interfere with depot performance This section opens the depot to the private market . 53 Chapter 159 – Real Property

A hall for assembly and cryogenic tests

International Nuclear Information System (INIS)

Beaunier, J.; Buhler, S.; Caruette, A.; Chevrollier, R.; Junquera, T.; Le Scornet, J.C.

1999-01-01

Cryodrome, an assembly hall and the testing ground for cryogenic equipment and R and D experiments for the superconducting cavities is going to be transformed for its future missions. The cryogenic utilities, especially the He low pressure pumping capacity, was rearranged and extended to a new area. Space was provided to install CRYHOLAB, a new horizontal cryostat for cavity testing. Automatic control and supervision of the utilities and the experimental area are rebuilt and updated. (authors)

Analysis and Design of Cryogenic Pressure Vessels for Automotive Hydrogen Storage

Science.gov (United States)

Espinosa-Loza, Francisco Javier

Cryogenic pressure vessels maximize hydrogen storage density by combining the high pressure (350-700 bar) typical of today's composite pressure vessels with the cryogenic temperature (as low as 25 K) typical of low pressure liquid hydrogen vessels. Cryogenic pressure vessels comprise a high-pressure inner vessel made of carbon fiber-coated metal (similar to those used for storage of compressed gas), a vacuum space filled with numerous sheets of highly reflective metalized plastic (for high performance thermal insulation), and a metallic outer jacket. High density of hydrogen storage is key to practical hydrogen-fueled transportation by enabling (1) long-range (500+ km) transportation with high capacity vessels that fit within available spaces in the vehicle, and (2) reduced cost per kilogram of hydrogen stored through reduced need for expensive structural material (carbon fiber composite) necessary to make the vessel. Low temperature of storage also leads to reduced expansion energy (by an order of magnitude or more vs. ambient temperature compressed gas storage), potentially providing important safety advantages. All this is accomplished while simultaneously avoiding fuel venting typical of cryogenic vessels for all practical use scenarios. This dissertation describes the work necessary for developing and demonstrating successive generations of cryogenic pressure vessels demonstrated at Lawrence Livermore National Laboratory. The work included (1) conceptual design, (2) detailed system design (3) structural analysis of cryogenic pressure vessels, (4) thermal analysis of heat transfer through cryogenic supports and vacuum multilayer insulation, and (5) experimental demonstration. Aside from succeeding in demonstrating a hydrogen storage approach that has established all the world records for hydrogen storage on vehicles (longest driving range, maximum hydrogen storage density, and maximum containment of cryogenic hydrogen without venting), the work also

Electric Propellant Solid Rocket Motor Thruster Results Enabling Small Satellites

OpenAIRE

Koehler, Frederick; Langhenry, Mark; Summers, Matt; Villarreal, James; Villarreal, Thomas

2017-01-01

Raytheon Missile Systems has developed and tested true on/off/restart solid propellant thrusters which are controlled only by electrical current. This new patented class of energetic rocket propellant is safe, controllable and simple. The range of applications for this game changing technology includes attitude control systems and a safe alternative to higher impulse space satellite thrusters. Described herein are descriptions and performance data for several small electric propellant solid r...

Experimental research on air propellers

Science.gov (United States)

Durand, William F

1918-01-01

The purposes of the experimental investigation on the performance of air propellers described in this report are as follows: (1) the development of a series of design factors and coefficients drawn from model forms distributed with some regularity over the field of air-propeller design and intended to furnish a basis of check with similar work done in other aerodynamic laboratories, and as a point of departure for the further study of special or individual types and forms; (2) the establishment of a series of experimental values derived from models and intended for later use as a basis for comparison with similar results drawn from certain selected full-sized forms and tested in free flight.

Monitoring and documentation of side effects from depot antipsychotic medication: an interdisciplinary audit of practice in a regional mental health service.

LENUS (Irish Health Repository)

Cleary, A

2012-01-01

The aim of this audit was to review current practice within a rural mental health service area on the monitoring and documentation of side effects of antipsychotic depot medication. Following a review of the literature on best practice internationally, an evidence based audit tool was adapted. A sample of 60 case files, care plans and prescriptions were audited between January and May 2010. This represented 31% of the total number of service users receiving depot injections in the mental health service region (n=181). The audit results revealed that most service users had an annual documented medical review and a documented prescription. However, only 5 (8%) case notes examined had documentation recorded describing the condition of the injection site and alternation of the injection site was recorded in only 28 (47%) case notes. No case notes examined had written consent to commence treatment recorded, and only 3 (5%) of case notes had documented that information on the depot injection and side effects was given. In 57 (95%) of case notes no documentation of recorded information on the depot and on side effects was given. Documentation of physical observations and tests revealed that 58% of cases had full blood count, liver function tests, thyroid function tests and fasting lipids recorded. All other tests (i.e. temperature, pulse, respirations, blood pressure, ECG) were recorded in less than 50% of cases. Prolactin levels were not recorded in any case. The lack of written consent was partly attributed to lack of recording of consent. The failure to monitor and record some\\r\

Treatment of central precocious puberty by subcutaneous injections of leuprorelin 3-month depot (11.25 mg).

Science.gov (United States)

Carel, Jean-Claude; Lahlou, Najiba; Jaramillo, Orlando; Montauban, Vincent; Teinturier, Cécile; Colle, Michel; Lucas, Christel; Chaussain, Jean Louis

2002-09-01

Depot GnRH agonists are widely used for the treatment of precocious puberty. Leuprorelin 3-month depot is currently used in adults but has not been evaluated in children. We evaluated the efficacy of this new formulation (11.25 mg every 3 months), for the suppression of gonadotropic activation and pubertal signs in children with central precocious puberty. We included 44 children (40 girls) with early-onset pubertal development in a 6-month open trial. The inclusion criteria were clinical pubertal development before the age of 8 (girls) or 10 (boys), advanced bone age, enlarged uterus (>36 mm), testosterone more than 1.7 nmol/liter (boys), and pubertal response of LH to GnRH (peak >5 IU/liter). The principal criterion for efficacy assessment, GnRH-stimulated LH peak less than 3 IU/liter, was met in 81 of 85 (95%) of the tests performed at months 3 and 6. The remaining four values were slightly above the threshold. The levels of sex steroids were also significantly reduced and clinical pubertal development was arrested. Plasma leuprorelin levels, measured every 30 d, were essentially stable after d 60. Local intolerance was noted after 10 of 86 injections (12%), and was mild in four cases, moderate in five cases, and severe in one. Among these 10 events, 4 consisted in local pain at injection's site. In conclusion, leuprorelin 3-month depot efficiently inhibits the gonadotropic axis in 95% of children with central precocious puberty studied for a 6-month period. This regimen allows the reduction of the number of yearly injections from 12 to 4.

Cryogenic system for the HERA magnet measurement facility

International Nuclear Information System (INIS)

Barton, H.R. Jr.; Clausen, M.; Kebler, G.

1986-01-01

This paper describes the design for a helium, cryogenic distribution system that allows independent operation and testing of superconducting magnets of the HERA project before they are installed in the 6-km ring tunnel. The 820-GeV proton storage ring of HERA will contain approximately 650 magnets having superconducting coils which are clamped by aluminum/stainless-steel collars and surrounded by a yoke of magnetic iron at liquid helium temperature. When the magnets arive at DESY from the manufacture, each magnet will be individually tested at helium operating conditions in the magnet measurement facility to insure the quality of the magnetic characteristics and the cryogenic performance. The capabilities of the cryogenic system and the schedule for magnet testing are discussed

Validation and Performance of the LHC Cryogenic System through Commissioning of the First Sector

CERN Document Server

Serio, L; Casas-Cubillos, J; Chakravarty, A; Claudet, S; Gicquel, F; Gomes, P; Kumar, M; Kush, PK; Millet, F; Perin, A; Rabehl, R; Singh, MR; Soubiran, M; Tavian, L

2008-01-01

The cryogenic system [1] for the Large Hadron Collider accelerator is presently in its final phase of commissioning at nominal operating conditions. The refrigeration capacity for the LHC is produced using eight large cryogenic plants and eight 1.8 K refrigeration units installed on five cryogenic islands. Machine cryogenic equipment is installed in a 26.7-km circumference ring deep underground tunnel and are maintained at their nominal operating conditions via a distribution system consisting of transfer lines, cold interconnection boxes at each cryogenic island and a cryogenic distribution line. The functional analysis of the whole system during all operating conditions was established and validated during the first sector commissioning in order to maximize the system availability. Analysis, operating modes, main failure scenarios, results and performance of the cryogenic system are presented.

PENGARUH PENGGUNAAN ENERGY SAVING DEVICE PADA PROPELLER B4 55 DENGAN METODE CFD

Directory of Open Access Journals (Sweden)

Andi Trimulyono

2013-10-01

Full Text Available Tingginya harga bahan bakar semakin mendorong pelaku industri khususnya pemilik kapal melakukan penghematan konsumsi bahan bakar dan cara yang cukup efektif untuk mengurangi konsumsi bahan bakar tersebut adalah dengan menambah instalasi alat yang disebut Energy Saving Device (ESD pada propeller dengan tujuan meningkatkan efisiensi propulsi.   Beberapa desain  ESD propeller yang telah dikembangkan yakni Ducted Propellers (Kort Nozzel propeller, dan Propeller Boss Cap Fins (PBCF. Perbedaan jenis Energy Saving Device (ESD mengindikasikan perubahan gaya torque dan thrust yang berbeda sehingga penulis disini ingin menganalisa pengaruh instalasi Energy Saving Device (ESD  pada propeller terhadap torque dan thrust yang dihasilkan sehingga dapat diketahui jenis ESD dengan performa paling optimal dengan bantuan paket program CAD (Computer Aided Design serta CFD (Computational Fluid Dynamics. Hasil analisa dengan menggunakan RANS software CFD menunjukkan akibat penambahan instalasi Energy Saving Device (ESD  pada propeller, terjadi perubahan bentuk aliran fluida, yang berpengaruh pula terhadap nilai thrust dan torque yang dihasilkan. Gaya thrust yang terjadi pada pada PBCF Propeller adalah sebesar 8.70E+05 N, dengan Torque 7.18E+05, sedangkan thrust pada Nozzle Propeller adalah sebesar 1.18E+06 dengan Torque 9.86E+05

Engine-propeller power plant aircraft community noise reduction key methods

Science.gov (United States)

Moshkov P., A.; Samokhin V., F.; Yakovlev A., A.

2018-04-01

Basic methods of aircraft-type flying vehicle engine-propeller power plant noise reduction were considered including single different-structure-and-arrangement propellers and piston engines. On the basis of a semiempirical model the expressions for blade diameter and number effect evaluation upon propeller noise tone components under thrust constancy condition were proposed. Acoustic tests performed at Moscow Aviation institute airfield on the whole qualitatively proved the obtained ratios. As an example of noise and detectability reduction provision a design-and-experimental estimation of propeller diameter effect upon unmanned aircraft audibility boundaries was performed. Future investigation ways were stated to solve a low-noise power plant design problem for light aircraft and unmanned aerial vehicles.

Feasibility Study and Demonstration of an Aluminum and Ice Solid Propellant

Directory of Open Access Journals (Sweden)

Timothee L. Pourpoint

2012-01-01

Full Text Available Aluminum-water reactions have been proposed and studied for several decades for underwater propulsion systems and applications requiring hydrogen generation. Aluminum and water have also been proposed as a frozen propellant, and there have been proposals for other refrigerated propellants that could be mixed, frozen in situ, and used as solid propellants. However, little work has been done to determine the feasibility of these concepts. With the recent availability of nanoscale aluminum, a simple binary formulation with water is now feasible. Nanosized aluminum has a lower ignition temperature than micron-sized aluminum particles, partly due to its high surface area, and burning times are much faster than micron aluminum. Frozen nanoscale aluminum and water mixtures are stable, as well as insensitive to electrostatic discharge, impact, and shock. Here we report a study of the feasibility of an nAl-ice propellant in small-scale rocket experiments. The focus here is not to develop an optimized propellant; however improved formulations are possible. Several static motor experiments have been conducted, including using a flight-weight casing. The flight weight casing was used in the first sounding rocket test of an aluminum-ice propellant, establishing a proof of concept for simple propellant mixtures making use of nanoscale particles.

The European Graduate Course in Cryogenics hosted at CERN.

CERN Multimedia

Laurent Tavian

2010-01-01

The “liquid helium” week of the European Graduate Course in Cryogenics was held at CERN from 30 August to 3 September 2010. This course scheduled annually since 2008 is a common teaching project of the Universities of Technology of Dresden, Wroclaw and Trondheim. It is focused on liquid natural gas, hydrogen and helium cryogenics. Attending students were carefully selected, and will take an examination giving ECTS credits for their academic curriculum.   This year, as Wroclaw University of Technology was already heavily involved in organising the International Cryogenic Engineering Conference (ICEC), it requested that the “liquid helium” week to be exceptionally held at CERN. While this is certainly a good choice from the point of view of large cryogenic helium systems, with the large cryoplants cooling the Large Hadron Collider (LHC) and its experiments, CERN has only acted as host laboratory organizing the course classes and visits, and the teaching and i...

Effect of gamma radiation on properties of a composite rocket propellant

International Nuclear Information System (INIS)

Dedgaonkar, V.G.; Pol, V.G.; Navle, P.B.; Ghorpade, V.G.; Wani, V.S.

2000-01-01

Gamma radiation was employed for modifying the properties of a composite rocket propellant prepared in a standard way. It was observed that when the same gamma dose was imparted to hydroxy terminated polybutadiene (HTPB) then converted into propellant, the enhancement in the properties was much larger than the irradiated propellant samples. (author)

Cryogenic regenerators

International Nuclear Information System (INIS)

Kush, P.; Joshi, S.C.; Thirumaleshwar, M.

1986-01-01

Importance of regenerators in cryogenic refrigerators is highlighted. Design aspects of regenerator are reviewed and the factors involved in the selection of regenerator material are enumerated. Various methods used to calculate the heat transfer coefficient and regenerator effectiveness are mentioned. Variation of effectiveness with various parameters is calculated by a computer programme using the ideal, Ackermann and Tipler formulae. Results are presented in graphical form. Listing of the computer programme is given in the Appendix. (author)

A Study of Flame Physics and Solid Propellant Rocket Physics

National Research Council Canada - National Science Library

Buckmaster, John

2007-01-01

..., the combustion of heterogeneous propellants containing aluminum, the use of a genetic algorithm to optimally define false-kinetics parameters in propellant combustion modeling, the calculation of fluctuations...

Implementation of time synchronized cryogenics control system network architecture for SST-1

Energy Technology Data Exchange (ETDEWEB)

Patel, Rakesh J., E-mail: rpatel@ipr.res.in; Mahesuria, Gaurang; Panchal, Pradip; Panchal, Rohit; Sonara, Dasarath; Tanna, Vipul; Pradhan, Subrata

2016-11-15

Highlights: • SST-1 cryogenics sub-systems are 1.3 kW HRL, LN2 distribution system, current feeders system and 80 K booster system. • GUI developed in SCADA and control program developed in PLC for automation of the above sub-systems. • Implemented the cryogenics control system network to communicate all systems to InSQL server. • InSQL server configured for real time centralized process data acquisition from all connected sub-systems control nodes. • Acquired the process parameters coming from different systems at same time stamp. - Abstract: Under the SST-1 mission mandate, the several cryogenic sub-systems have been developed, upgraded and procured in prior to the SST-1 operation. New developments include 80 K Bubble type thermal shields, LN2 distribution system, LN2 booster system and current feeders system (CFS).Graphical User Interface (GUI) program developed in Wonderware SCADA and control logic program developed in Schneider make PLC for the above sub-systems. Industrial SQL server (InSQL) configured for centralized storage of real time process data coming from various control nodes of cryogenics sub-systems. The cryogenics control system network for communicating all cryogenics sub-system control nodes to InSQL server for centralized data storage and time synchronization among cryogenic sub-systems with centralized InSQL server is successfully implemented. Due to implemented time synchronization among sub-systems control nodes, it is possible to analyze the process parameters coming from different sub-systems at same time stamp. This paper describes the overview of implemented cryogenics control system network architecture for real time cryogenic process data monitor, storage and retrieval.

Implementation of time synchronized cryogenics control system network architecture for SST-1

International Nuclear Information System (INIS)

Patel, Rakesh J.; Mahesuria, Gaurang; Panchal, Pradip; Panchal, Rohit; Sonara, Dasarath; Tanna, Vipul; Pradhan, Subrata

2016-01-01

Highlights: • SST-1 cryogenics sub-systems are 1.3 kW HRL, LN2 distribution system, current feeders system and 80 K booster system. • GUI developed in SCADA and control program developed in PLC for automation of the above sub-systems. • Implemented the cryogenics control system network to communicate all systems to InSQL server. • InSQL server configured for real time centralized process data acquisition from all connected sub-systems control nodes. • Acquired the process parameters coming from different systems at same time stamp. - Abstract: Under the SST-1 mission mandate, the several cryogenic sub-systems have been developed, upgraded and procured in prior to the SST-1 operation. New developments include 80 K Bubble type thermal shields, LN2 distribution system, LN2 booster system and current feeders system (CFS).Graphical User Interface (GUI) program developed in Wonderware SCADA and control logic program developed in Schneider make PLC for the above sub-systems. Industrial SQL server (InSQL) configured for centralized storage of real time process data coming from various control nodes of cryogenics sub-systems. The cryogenics control system network for communicating all cryogenics sub-system control nodes to InSQL server for centralized data storage and time synchronization among cryogenic sub-systems with centralized InSQL server is successfully implemented. Due to implemented time synchronization among sub-systems control nodes, it is possible to analyze the process parameters coming from different sub-systems at same time stamp. This paper describes the overview of implemented cryogenics control system network architecture for real time cryogenic process data monitor, storage and retrieval.

Propeller performance analysis using lifting line theory

OpenAIRE

Flood, Kevin M.

2009-01-01

CIVINS (Civilian Institutions) Thesis document Approved for public release ; distribution is unlimited Propellers are typically optimized to provide the maximum thrust for the minimum torque at a specific number of revolutions per minute (RPM) at a particular ship speed. This process allows ships to efficiently travel at their design speed. However, it is useful to know how the propeller performs during off-design conditions. This is especially true for naval warships whose missions req...

PIV-based load determination in aircraft propellers

OpenAIRE

Ragni, D.

2012-01-01

The thesis describes the application of particle image velocimetry (PIV) to study the aerodynamic loads of airfoils and aircraft propellers. The experimental work focuses on the development of a measurement procedure to infer the pressure of the flow field from the velocity distribution obtained by PIV velocimetry. The technique offers important advantages in aircraft propellers, since the loads can be locally inspected without the need to install pressure sensors and momentum balances in rot...

[A preliminary study of low dosage zuclopenthixol depot in Alzheimer's disease].

Science.gov (United States)

Robles, A; Rodríguez Navarrete, F J; Taboada, O; Docasar, L; Páramo, M; Noya, M

1996-03-01

Persistent psychomotor agitation and psychotic ideation in patients with Alzheimer's disease are normally treated orally with antipsychotic drugs and are occasionally treated with other drugs. Neuroleptics administered intramuscularly at very low doses are an alternative, especially when the patient rejects medicine as a results of his or her anosognosia or of paranoid manifestations. We present the results we obtained after observing the effects of depot zuclopenthixol in six patients with probable Alzheimer's disease (based upon NINCDS-ADRDA criteria). Psychic abnormalities were assessed as per the Brief Psychiatric Rating Scale (BPRS), the Scale for the Assessment of Positive Symptoms (SAPS) and the Scale for the Assessment of Negative Symptoms (SANS). Possible extrapyramidal side effects were evaluated by means of the Abnormal Involuntary Movement Scale (AIMS). Initially 60 mg (0.3 ml) were administered intramuscularly and successive doses could be modified by +/-20 mg (0.1 ml) according to results seen on the various scales. During the first six weeks of treatment progressive improvement was noted on all three psychic functions scales in all patients. Between the sixth and twelfth weeks improvement continued although without significant change. The AIMS did not show significant changes in the twelve weeks of follow-up. We consider depot zuclopenthixol at low doses as efficacious in treating persistent psychomotor agitation and/or psychotic manifestations of Alzheimer's disease. No undesired side effects were observed in our group after a twelve week follow-up.

The multi-depot electric vehicle location routing problem with time windows

Directory of Open Access Journals (Sweden)

Juan Camilo Paz

2018-01-01

Full Text Available In this paper, the Multi-Depot Electric Vehicle Location Routing Problem with Time Windows (MDVLRP is addressed. This problem is an extension of the MDVLRP, where electric vehicles are used instead of internal combustion engine vehicles. The recent development of this model is explained by the advantages of this technology, such as the diminution of carbon dioxide emissions, and the support that they can provide to the design of the logistic and energy-support structure of electric vehicle fleets. There are many models that extend the classical VRP model to take electric vehicles into consideration, but the multi-depot case for location-routing models has not been worked out yet. Moreover, we consider the availability of two energy supply technologies: the “Plug-in” Conventional Charge technology, and Battery Swapping Stations; options in which the recharging time is a function of the amount of energy to charge and a fixed time, respectively. Three models are proposed: one for each of the technologies mentioned above, and another in which both options are taken in consideration. The models were solved for small scale instances using C++ and Cplex 12.5. The results show that the models can be used to design logistic and energy-support structures, and compare the performance of the different options of energy supply, as well as measure the impact of these decisions on the overall distance traveled or other optimization objectives that could be worked on in the future.

Cryogenic testing of the TPC superconducting solenoid

International Nuclear Information System (INIS)

Green, M.A.; Smits, R.G.; Taylor, J.D.

1983-06-01

This report describes the results of a series of tests on the TPC superconducting magnet cryogenic system which occurred during the winter and spring of 1983. The tests occurred at interaction region 2 of the PEP colliding beam facility at the Stanford Linear Accelerator Center (SLAC). The TPC Magnet Cryogenic System which was tested includes the following major components: a remote helium compressor with a full flow liquid nitrogen purification station, 400 meters of high pressure supply and low pressure return lines; and locally a CTi Model 2800 refrigerator with two Sulzer gas bearing turbines, the TPC magnet control dewar, 70 meters of transfer lines, and the TPC thin superconducting solenoid magnet. In addition, there is a conditioner (liquid nitrogen heat exchangers and gas heaters) system for cooldown and warmup of the magnet. This report describes the local cryogenic system and describes the various steps in the cooldown and operation of the TPC magnet. The tests were successful in that they showed that the TPC magnet could be cooled down in 24 hours and the magnet could be operated on the refrigerator or a helium pump with adequate cooling margin. The tests identified problems with the cryogenic system and the 2800 refrigerator. Procedures for successful operation and quenching of the superconducting magnet were developed. 19 references

Cryogenic Liquid Fluctuations in a Motionless Tank

Directory of Open Access Journals (Sweden)

Min Vin Ai

2014-01-01

Full Text Available The article considers approximate numerical methods to determine own frequencies of cryogenic liquid fluctuations stratification of which changes under any law. The increasing use of cryogenic liquids, liquefied gas, superfluid solutions, and slush liquids in modern mechanical engineering define relevance of a perspective. Interest in the considered problem is also caused by the fact that in cryogenic liquid along with superficial waves there can be internal wave movements penetrating all thickness of liquid in a tank and therefore playing important role in many hydro-dynamic processes.This article considers problems of determining the own frequencies of cryogenic liquid fluctuations, partially filling cylindrical tank of any cross section. It is supposed that the change of the liquid particles density due to thermal stratification of entire liquid mass can proceed continuously under any law. To solve numerically a similar problem, a method of trigonometric series (MTS and a method of final elements (MFE were used. When using the MTS method the unknown solution and variable coefficients of the equation were presented in the form of trigonometric series. Further, after multiplication of series and the subsequent mathematical operations the frequency equation was obtained. Bubnov-Galyorkin's approach was used to obtain solutions by the MFE method. Reliability of received numerical results is confirmed by coincidence with frequency results calculated by analytical formulas of solutions of differential equations with constant frequency of buoyancy.

DEPOT system for the creation of a translator from the COC language

International Nuclear Information System (INIS)

Kehnig, Kh.; Lehttsch, Yu.; Nefed'eva, L.S.; Shtiller, G.

1976-01-01

Approaches to the creation of specialized languages and their translators are given. The DENOT system for developing translators from various specialized languages is described. Use of the system was made to translate the STS (spectra treatment system) language into the FORTRAN language.The language of STS was realized with help of DEPOT on the BESM-6 computer. The DEROT system installed at various computer provides for simple and rapid transition from one computer to the other

Simultaneous enhancement of strength and ductility in cryogenically treated AISI D2 tool steel

Energy Technology Data Exchange (ETDEWEB)

Ghasemi-Nanesa, Hadi; Jahazi, Mohammad, E-mail: mohammad.jahazi@etsmtl.ca

2014-03-01

In this research, the effect of cryogenic treatment on microstructural evolution and mechanical properties enhancement of AISI D2 tool steel was investigated. Cryogenic treatment down to liquid nitrogen temperature (77 K) was added to the conventional heat treatment between hardening and tempering steps. Electron microscopy investigation showed higher volume fraction of fine carbides with average diameter below 1 μm indicating effective retardation in carbide coarsening process as a results of cryogenic treatment. A modification in types of carbides was also observed after cryogenic treatment. X-ray diffraction diagrams revealed transformation of retained austenite to martensite at cryogenic temperature. Weakening or removal of carbides peak in the X-ray diagram was considered as evidence of carbides different behavior at cryogenic temperature. Mechanical testing results indicated higher ultimate tensile strength, better ductility, and higher elastic modulus after cryogenic treatment. Analysis of stress–strain diagrams revealed different strain hardening behavior for cryogenically treated alloy when compared to the conventionally heat treated one. Fractography results confirmed strain hardening behavior and showed cleavage fracture for conventionally treated alloy but mixed cleavage–ductile fracture mode for cryogenically treated alloy. The improved mechanical properties after cryogenic treatment are interpreted in terms of the influence of higher volume fraction and uniform distribution of fine carbides in reducing the average active dislocations length and enhancement of the flow stress at any given plastic strain.

Simultaneous enhancement of strength and ductility in cryogenically treated AISI D2 tool steel

International Nuclear Information System (INIS)

Ghasemi-Nanesa, Hadi; Jahazi, Mohammad

2014-01-01

In this research, the effect of cryogenic treatment on microstructural evolution and mechanical properties enhancement of AISI D2 tool steel was investigated. Cryogenic treatment down to liquid nitrogen temperature (77 K) was added to the conventional heat treatment between hardening and tempering steps. Electron microscopy investigation showed higher volume fraction of fine carbides with average diameter below 1 μm indicating effective retardation in carbide coarsening process as a results of cryogenic treatment. A modification in types of carbides was also observed after cryogenic treatment. X-ray diffraction diagrams revealed transformation of retained austenite to martensite at cryogenic temperature. Weakening or removal of carbides peak in the X-ray diagram was considered as evidence of carbides different behavior at cryogenic temperature. Mechanical testing results indicated higher ultimate tensile strength, better ductility, and higher elastic modulus after cryogenic treatment. Analysis of stress–strain diagrams revealed different strain hardening behavior for cryogenically treated alloy when compared to the conventionally heat treated one. Fractography results confirmed strain hardening behavior and showed cleavage fracture for conventionally treated alloy but mixed cleavage–ductile fracture mode for cryogenically treated alloy. The improved mechanical properties after cryogenic treatment are interpreted in terms of the influence of higher volume fraction and uniform distribution of fine carbides in reducing the average active dislocations length and enhancement of the flow stress at any given plastic strain

Cryogenics for the MuCool Test Area (MTA)

International Nuclear Information System (INIS)

Darve, Christine; Norris, Barry; Pei, Liujin

2006-01-01

MuCool Test Area (MTA) is a complex of buildings at Fermi National Accelerator Laboratory, which are dedicated to operate components of a cooling cell to be used for Muon Collider and Neutrino Factory R and D. The long-term goal of this facility is to test ionization cooling principles by operating a 25-liter liquid hydrogen (LH2) absorber embedded in a 5 Tesla superconducting solenoid magnet. The MTA solenoid magnet will be used with RF cavities exposed to a high intensity beam. Cryogens used at the MTA include LHe, LN2 and LH2. The latter dictates stringent system design for hazardous locations. The cryogenic plant is a modified Tevatron refrigerator based on the Claude cycle. The implementation of an in-house refrigerator system and two 300 kilowatt screw compressors is under development. The helium refrigeration capacity is 500 W at 14 K. In addition the MTA solenoid magnet will be batch-filled with LHe every 2 days using the same cryo-plant. This paper reviews cryogenic systems used to support the Muon Collider and Neutrino Factory R and D programs and emphasizes the feasibility of handling cryogenic equipment at MTA in a safe manner

Electromagnetic dampers for cryogenic applications

Science.gov (United States)

Brown, Gerald V.; Dirusso, Eliseo

1988-01-01

Cryogenic turbomachinery of the type used to pump high-pressure liquid hydrogen at -423 F and liquid oxygen at -297 F to the main engines of the Space Shuttle are subjected to lateral rotor vibrations from unbalance forces and transient loads. Conventional dampers which utilize viscous fluids such as lubricating oil cannot be used in turbopumps because the bearing components are filled with either liquid hydrogen or liquid oxygen, which have viscosity comparable to air and, therefore, are not effective in viscous dampers. Electromagentic dampers are currently being explored as a means of providing damping in cryogenic turbopumps because their damping effectiveness increases as temperature decreases and because they are compatible with the liquid hydrogen or liquid oxygen in the turbopumps.

High-Fidelity Microstructural Characterization and Performance Modeling of Aluminized Composite Propellant

International Nuclear Information System (INIS)

Kosiba, Graham D.; Wixom, Ryan R.; Oehlschlaeger, Matthew A.

2017-01-01

Image processing and stereological techniques were used to characterize the heterogeneity of composite propellant and inform a predictive burn rate model. Composite propellant samples made up of ammonium perchlorate (AP), hydroxyl-terminated polybutadiene (HTPB), and aluminum (Al) were faced with an ion mill and imaged with a scanning electron microscope (SEM) and x-ray tomography (micro-CT). Properties of both the bulk and individual components of the composite propellant were determined from a variety of image processing tools. An algebraic model, based on the improved Beckstead-Derr-Price model developed by Cohen and Strand, was used to predict the steady-state burning of the aluminized composite propellant. In the presented model the presence of aluminum particles within the propellant was introduced. The thermal effects of aluminum particles are accounted for at the solid-gas propellant surface interface and aluminum combustion is considered in the gas phase using a single global reaction. In conclusion, properties derived from image processing were used directly as model inputs, leading to a sample-specific predictive combustion model.

A Portable Burn Pan for the Disposal of Excess Propellants

Science.gov (United States)

2016-06-01

2013 - 06/01/2016 A Portable Burn Pan for the Disposal of Excess Propellants Michael Walsh USA CRREL USA CRREL 72 Lyme Road Hanover, NH 03755...Army Alaska XRF X-Ray Florescence vii ACKNOWLEDGEMENTS Project ER-201323, A Portable Burn Pan for the Disposal of Gun Propellants, was a very...contamination problem while allowing troops to train as they fight, we have developed a portable training device for burning excess gun propellants. 1.1

14 CFR 35.21 - Variable and reversible pitch propellers.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Variable and reversible pitch propellers. 35.21 Section 35.21 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: PROPELLERS Design and Construction § 35.21 Variable and...

Plane boundary effects on characteristics of propeller jets

Science.gov (United States)

Wei, Maoxing; Chiew, Yee-Meng; Hsieh, Shih-Chun

2017-10-01

The flow properties of a propeller jet in the presence of a plane bed boundary were investigated using the particle image velocimetry technique. Three clearance heights, Z b = 2 D p, D p, and 0.5 D p, where D p = propeller diameter, were used to examine boundary effects on the development of the jet. In each case, the mean flow properties and turbulence characteristics were measured in a larger field of view than those used in past studies. Both the streamwise and transverse flow fields were measured to obtain the three-dimensional characteristics of the propeller jet. Similar to a confined offset jet, the propeller jet also exhibits a wall attachment behavior when it is placed near a plane boundary. As a result, in contrast to its unconfined counterpart, the confined propeller jet features three regions, namely the free jet, impingement and wall jet regions. The study shows that the extent of each region varies under different clearance heights. The development of the mean flow and turbulence characteristics associated with varying clearance heights are compared to illustrate boundary effects in these regions. In the impingement region, the measured transverse flow fields provide new insights on the lateral motions induced by the impingement of the swirling jet. In the wall jet region, observations reveal that the jet behaves like a typical three-dimensional wall jet and its axial velocity profiles show good agreement with the classical wall jet similarity function.

Influence of Thermal Cycling on Cryogenic Thermometers

CERN Document Server

Balle, C; Rieubland, Jean Michel; Suraci, A; Togny, F; Vauthier, N

1999-01-01

The stringent requirements on temperature control of the superconducting magnets for the Large Hadron Collider (LHC), impose that the cryogenic temperature sensors meet compelling demands such as long-term stability, radiation hardness, readout accuracy better than 5 mK at 1.8 K and compatibility with industrial control equipment. This paper presents the results concerning long-term stability of resistance temperature sensors submitted to cryogenic thermal cycles. For this task a simple test facility has been designed, constructed and put into operation for cycling simultaneously 115 cryogenic thermometers between 300 K and 4.2 K. A thermal cycle is set to last 71/4 hours: 3 hours for either cooling down or warming up the sensors and 1 respectively 1/4 hour at steady temperature conditions at each end of the temperature cycle. A Programmable Logic Controller (PLC) drives automatically this operation by reading 2 thermometers and actuating on 3 valves and 1 heater. The first thermal cycle was accomplished in a...

Insulation design of cryogenic bushing for superconducting electric power applications

Energy Technology Data Exchange (ETDEWEB)

Koo, J.Y., E-mail: koojy@hanyang.ac.kr [Department of Electronics, Electrical, Control and Instrumentation Engineering, Hanyang University, Ansan 426-791 (Korea, Republic of); Lee, Y.J.; Shin, W.J.; Kim, Y.H. [Department of Electronics, Electrical, Control and Instrumentation Engineering, Hanyang University, Ansan 426-791 (Korea, Republic of); Kim, J.T. [Department of Electrical Engineering, Daejin University, Pocheon 487-711 (Korea, Republic of); Lee, B.W. [Department of Electronics, Electrical, Control and Instrumentation Engineering, Hanyang University, Ansan 426-791 (Korea, Republic of); Lee, S.H., E-mail: k720lsh@kins.re.kr [Expert Group Electric and Control Department, Korea Institute of Nuclear Safety, Daejeon 305-600 (Korea, Republic of)

2013-01-15

Highlights: ► In this paper, design factors of cryogenic bushings were discussed and test results of specimen were introduced in detail. ► We focused on the comparative study of breakdown characteristics of different electrode materials. ► Puncture and creepage breakdown characteristics were analyzed based on the withstand voltage. ► We obtained the basic design factors of extra high voltage condenser bushing. ► We obtained the basic design factors of extra high voltage condenser bushing, which could be used in cryogenic environment. -- Abstract: Recently, the superconductivity projects to develop commercial superconducting devices for extra high voltage transmission lines have been undergoing in many countries. One of the critical components to be developed for high voltage superconducting devices, including superconducting transformers, cables, and fault current limiters, is a high voltage bushing, to supply high current to devices without insulating difficulties, that is designed for cryogenic environments. Unfortunately, suitable bushings for HTS equipment were not fully developed for some cryogenic insulation issues. Such high voltage bushings would need to provide electrical insulation capabilities from room temperature to cryogenic temperatures. In this paper, design factors of cryogenic bushings were discussed and test results of specimen were introduced in detail. First, the dielectric strength of three kinds of metals has been measured with uniform and non-uniform electrodes by withstand voltage of impulse and AC breakdown test in LN{sub 2}. Second, puncture breakdown voltage of glass fiber reinforced plastics (GFRPs) plates has been analyzed with non-uniform electrodes. Finally, creepage discharge voltages were measured according to the configuration of non-uniform and uniform electrode on the FRP plate. From the test results, we obtained the basic design factors of extra high voltage condenser bushing, which could be used in cryogenic

A VME based cryogenic data acquisition and control system (CRYO-DACS)

International Nuclear Information System (INIS)

Antony, Joby; Rajkumar; Datta, T.S.

2005-01-01

This report describes a newly developed VME based data acquisition and control system named CRYO-DACS for acquiring and controlling various analog and digital cryogenic parameters from equipment's like beam-line cryostats, Helium compressors, liquefier, cryogenic distribution line etc. A new central control room has been set-up for the remote controls and monitoring. The system monitors various analog parameters like temperature, pressure, vacuum and cryogenic fluid levels inside the cryostats and performs closed loop controls of cryogen valves. The hardware architecture of CRYO-DACS is multi-crate distributed VME, all linked by workstation clients in 100 Mb/s LAN for distributed logging, historical trending, analysis, alarm management and control GUIs. (author)

A tabu-search heuristic for solving the multi-depot vehicle scheduling problem

Directory of Open Access Journals (Sweden)

Gilmar D'Agostini Oliveira Casalinho

2014-08-01

Full Text Available Currently the logistical problems are relying quite significantly on Operational Research in order to achieve greater efficiency in their operations. Among the problems related to the vehicles scheduling in a logistics system, the Multiple Depot Vehicle Scheduling Problem (MDVSP has been addressed in several studies. The MDVSP presupposes the existence of depots that affect the planning of sequences to which travel must be performed. Often, exact methods cannot solve large instances encountered in practice and in order to take them into account, several heuristic approaches are being developed. The aim of this study was thus to solve the MDVSP using a meta-heuristic based on tabu-search method. The main motivation for this work came from the indication that only recently the use of meta-heuristics is being applied to MDVSP context (Pepin et al. 2008 and, also, the limitations listed by Rohde (2008 in his study, which used the branch-and-bound in one of the steps of the heuristic presented to solve the problem, which has increased the time resolution. The research method for solving this problem was based on adaptations of traditional techniques of Operational Research, and provided resolutions presenting very competitive results for the MDVSP such as the cost of the objective function, number of vehicles used and computational time.

Deconsolidation and combustion performance of thermally consolidated propellants deterred by multi-layers coating

Directory of Open Access Journals (Sweden)

Zheng-gang Xiao

2014-06-01

Full Text Available Both heating and solvent-spray methods are used to consolidate the standard grains of double-base oblate sphere propellants plasticized with triethyleneglycol dinitrate (TEGDN (TEGDN propellants to high density propellants. The obtained consolidated propellants are deterred and coated with the slow burning multi-layer coating. The maximum compaction density of deterred and coated consolidated propellants can reach up to 1.39 g/cm3. Their mechanic, deconsolidation and combustion performances are tested by the materials test machine, interrupted burning set-up and closed vessel, respectively. The static compression strength of consolidated propellants deterred by multi-layer coating increases significantly to 18 MPa, indicating that they can be applied in most circumstances of charge service. And the samples are easy to deconsolidate in the interrupted burning test. Furthermore, the closed bomb burning curves of the samples indicate a two-stage combustion phenomenon under the condition of certain thickness of coated multi-layers. After the outer deterred multi-layer coating of consolidated samples is finished burning, the inner consolidated propellants continue to burn and breakup into aggregates and grains. The high burning progressivity can be carefully obtained by the smart control of deconsolidation process and duration of consolidated propellants. The preliminary results of consolidated propellants show that a rapid deconsolidation process at higher deconsolidation pressure is presented in the dynamic vivacity curves of closed bomb test. Higher density and higher macro progressivity of consolidated propellants can be obtained by the techniques in this paper.

Real-Time Model-Based Leak-Through Detection within Cryogenic Flow Systems

Science.gov (United States)

Walker, M.; Figueroa, F.

2015-01-01

The timely detection of leaks within cryogenic fuel replenishment systems is of significant importance to operators on account of the safety and economic impacts associated with material loss and operational inefficiencies. Associated loss in control of pressure also effects the stability and ability to control the phase of cryogenic fluids during replenishment operations. Current research dedicated to providing Prognostics and Health Management (PHM) coverage of such cryogenic replenishment systems has focused on the detection of leaks to atmosphere involving relatively simple model-based diagnostic approaches that, while effective, are unable to isolate the fault to specific piping system components. The authors have extended this research to focus on the detection of leaks through closed valves that are intended to isolate sections of the piping system from the flow and pressurization of cryogenic fluids. The described approach employs model-based detection of leak-through conditions based on correlations of pressure changes across isolation valves and attempts to isolate the faults to specific valves. Implementation of this capability is enabled by knowledge and information embedded in the domain model of the system. The approach has been used effectively to detect such leak-through faults during cryogenic operational testing at the Cryogenic Testbed at NASA's Kennedy Space Center.

76 FR 25534 - Airworthiness Directives; Hamilton Sundstrand Propellers Model 247F Propellers

Science.gov (United States)