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1980-01-01 | Hydrogen is an excellent fuel because of (1) the widespread availability of water, its most common source, (2) the rapid recycling from hydrogen to water (regenerating its source quickly), (3) the resulting cleaner environment (almost no pollution caused from its use), (4) the potentially high efficiency in almost every suggested use, and (5) the compatibility with nearly every energy application, such as the internal combustion engine, and every energy source, such as solar. Hydrogen could become the fuel of the future given (1) an incentive to change from the present hydrocarbon fuel, (2) an energy source to produce the hydrogen, (3) an engine to run on hydrogen, and (4) an on-board hydrogen storage system. The on-board hydrogen storage system is discussed here. | Liquid Hydrogen as an Automotive Fuel | 10.1007/978-1-4613-9856-1_92 |
1980-01-01 | One of the main components of the detector experiment CELLO in the e^+e^- storage ring PETRA at DESY/Hamburg is the superconducting magnet system. The magnets have been developed as a joint project by CEN/Saclay and Kernforschungszentrum Karlsruhe. CEN has built the thin-walled main solenoid with a length of 3.5 m and a winding diameter of 1.7 m creating a magnetic field of 1.5 T in the center [^1]. Two magnetically identical solenoids, located symmetrical to the main coil, must be positioned with a magnetic field opposite to the central field to cancel the integral field effect on the orbiting particle beams. This compensating solenoid system, including its supporting cryogenic system, has been designed and constructed by the Kernforschungszentrum Karlsruhe. The main coil was constructed with a wall thickness of ≤ λ/2 (equivalent to 45 mm of aluminum); this requirement was imposed by the radiation length λ of the generated particles. The compensating coils, on the other hand, were designed and built by conventional techniques for superconducting magnets. The solenoids within their cryostats are to be mounted in movable iron yoke doors surrounded by muon chambers and a liquid argon end cap calorimeter as shown in Fig. 1. The outer geometry and the required warm bore parameters determine the dimensions of the cryostats, i.e., a length of 1.10 m and an outer and inner diameter of the horizontal part of 0.8 and 0.4 m, respectively. | Superconducting Compensating Solenoids for the Cello Detector Experiment at Petra | 10.1007/978-1-4613-9856-1_19 |
1980-01-01 | The volumetric expansion coefficient (∂ ln V /∂ T )_ p has been found useful in heat-transfer analyses. Yaskin et al . [^1] demonstrated its usefulness in groupie hehum heat-transfer data in the near-thermodynamic critical region. The author [^2] demonstrated the usefulness of the energy expansion coefficients (∂ ln V /∂ H )_ p in qualitatively grouping heat-transfer data for nitrogen and oxygen in the near-thermodynamic critical region; however, quantitative agreement has not yet been achieved. Hendricks et al . [^3] qualitatively demonstrated the relations between density fluctuations, volumetric expansion coefficient, and turbulent energy and momentum fluxes. The energy expansion coefficient was used in qualitatively grouping gaseous and fluid heat-transfer data of several investigators. These data sets for helium, hydrogen, air, nitrogen, carbon dioxide, and water cover a wide range of experimental conditions. | Reduced Volumetric Expansion and Isothermal Compressibility Factor Plots | 10.1007/978-1-4613-9856-1_78 |
1980-01-01 | The design and installation of test facilities for the determination of macro-mechanical and thermal properties of fiber-reinforced polymer materials at temperatures down to 4.2 K are presented. Construction and performance details are given for the following test equipment, developed at CERN: 1 Quasi-static-tensile and compression-test facilities equipped with an automatic data acquisition system for calculation of material properties, deformation characteristics, and various statistics (Fig. 1). 2 A thermal contraction-expansion measuring system. 3 A thermal conductivity measurement cell. | Tests of Composite Materials at Cryogenic Temperatures: Facilities and Results | 10.1007/978-1-4613-9859-2_28 |
1980-01-01 | The Los Alamos Scientific Laboratory of the University of California is presently developing a 30-MJ Superconducting Magnetic Energy Storage (SMES) unit for stabilizing an electric transmission system[^1] The SMES system will be installed on the Pacific AC Intertie that connects southern California and the Pacific Northwest and will be utilized to provide system damping of low-frequency power oscillations. The cryogenic cooling system being supplied to support the SMES system must meet stringent reliability, efficiency, size, and magnetic field operational requirements. | A 50-Liters/Hr Helium Liquefier for a Superconducting Magnetic Energy Storage System | 10.1007/978-1-4613-9856-1_66 |
1980-01-01 | The tensile properties of stable austenitic stainless steels such as AISI 310 (Fe-25Cr-20Ni-2Mn-0.08C) have a regular temperature dependence with trends similar to the classical behavior expected for metals and alloys having the facecentered cubic structure [^1]. The classical behavior consists of a smooth monotonic increase of yield stress as temperature is lowered to about 60 K. In contrast, metastable stainless steels such as AISI 304L (Fe-18Cr-9Ni-2Mn-0.03C) have yield-stress (σ_y)-vs.-temperature anomalies that are believed to be associated with low-temperature martensitic transformations to body-centered cubic (α′) and hexagonal close-packed (ε) phases [^2], In addition, both the stable and metastable alloys are capable of anomalous behavior at extreme cryogenic temperatures (below 60 K) owing to deformation mode changes associated with dislocation tunneling or magnetic transitions [^3]. | Temperature Dependence of Yielding in Austenitic Stainless Steels | 10.1007/978-1-4613-9859-2_11 |
1980-01-01 | This project is concerned with an example of a device intended to make the most effective use of available energy sources, a principle of increasing importance in present-day circumstances. The machine is intended to provide cooling power to around liquid nitrogen temperatures, especially in unfavorable or remote environments, where direct heat is the available form of energy. Accordingly, the proposed design needs to be rugged, requiring a minimum of maintenance and comprises only two moving parts sealed inside a cylindrical vessel. In this respect it is an improvement on the Vuilleumier refrigerator [^1] on which it is based. This study covers the digital computer simulation of the model, together with some proposals for a practical design. | A Closed-Cycle Thermally Activated Regenerative Cryogenerator | 10.1007/978-1-4613-9856-1_67 |
1980-01-01 | The development of ac power transmission cables, operated at cryogenic temperatures, has been pursued for both resistive and superconducting configurations because of their ability to transmit large blocks of power over a narrow right-of-way at high efficiency[^1–3].The eventual success of these new transmission concepts depends, to a large extent, upon their ability to demonstrate economic advantages over conventional cables. The cost and reliability of large helium refrigerators have been estimated for a 40-mile superconducting transmission line[^4]. | A Study of Refrigeration for Liquid-Nitrogen-Cooled Power Transmission Cables | 10.1007/978-1-4613-9856-1_68 |
1980-01-01 | Since the effect of mechanical loading on the superconducting properties of Nb_3Sn will be crucial for the development of large Nb_3Sn magnets, much work has been done on this subject [^1–4]. Although most results show an initial increase of the critical current upon uniaxial loading before stress-induced degradation, there also have been experiments indicating degradation only [^1–4]. The initial increase of the critical current, I_c, upon loading is due to the relief of a compressive stress on the superconducting layer, which is generated upon cooldown by differences of thermal contraction between the components of the conductor. At maximum I _c, the applied tensile stress just compensates the compressive stress. So the appearance of a maximum and the strain at the maximum will be determined by the internal stresses between the components. The mechanical properties at 4.2 K and the behavior of I _c under applied strain have been investigated for five commercial conductors, all stabilized by additional copper at the outside of the conductor. Since it is generally accepted that the reversible degradation of I _c is related to the degradation of the intrinsic parameters, the behavior of the critical temperature, T _c upon straining was also studied. | Stress Effects in Nb_3Sn-Nb-Bronze Composites | 10.1007/978-1-4613-9859-2_66 |
1980-01-01 | The high-tip speed experiment described in this study involves a cryogenic rotor designed to test an advanced cooling system for the rotor of a superconducting generator. The experiment does not include an actual superconductor field winding but does include a helium chamber typical of the winding space in an actual superconducting rotor. | Experimental Simulation of a Cryogenic System for a Large Superconducting Rotor | 10.1007/978-1-4613-9856-1_32 |
1980-01-01 | The majority of the cryogenic systems installed for cooling superconducting magnet systems over the past ten years have been aimed at providing a reliable experimental facility for proving the viability of superconductor systems and for advancing the state of the art of superconducting magnets. As a result, the criteria for cryogenic system selection has been that of lowest initial cost and maximum reliability. Systems now being installed and those being designed for future installation will be operated on a continuous basis giving impetus to an economic analysis in which the overall operating cost of the cryogenic facility becomes an increasingly important parameter in the design and selection of the system. In addition, conservation of energy through increased efficiency and conservation of helium will become significant design criteria. | Economics of Cryogenic Systems for Superconducting Magnets | 10.1007/978-1-4613-9856-1_40 |
1980-01-01 | If new sources of energy are to be fully exploited then an efficient energy storage system must be developed to meet variable demand. This is so because, in most cases, energy demands are periodic in nature whereas energy supply operates most efficiently on a constant output basis. | Storage of Hydrogen | 10.1007/978-1-349-02635-7_4 |
1980-01-01 | The fail-safe performance of advanced cryogenic structures, such as superconducting motors, generators, and magnets, can depend greatly on the ability of structural materials to sustain high stress and strain in the presence of flaws. Materials that have been widely used in these structural applications are stainless steels and structurally stable, austenitic nickel-base superalloys, including Inconel 718 [^1,2]. A considerable amount of fracture toughness and fatigue crack-growth rate (FCGR) data have been developed on both Inconel 718 base material and weldments at cryogenic temperatures [^3–11]. Fracture mechanics principles can be used to evaluate the initial allowable flaw sizes and cyclic life of critical structures from these data. | Cryogenic Fracture Toughness and Fatigue Crack-Growth Rate Properties of Inconel 706 Base Material and GAS Tungsten-ARC Weldments | 10.1007/978-1-4613-9859-2_14 |
1980-01-01 | The increase in the ductility of F.C.C. metals at cryogenic temperatures is due to the strain propagation facilitated by the increase in the work-hardening rate. In order to apply these characteristics to practical forming processes, the influence of cryogenic temperatures on the formability of copper and aluminium sheets in stretching, deep drawing and hole flanging was studied. The formability in these processes is improved at the cryogenic temperature and the increase in the forming limit, in particular, is most remarkable in stretching using a punch with a small punch shoulder radius. These results can be explained on the forming limit diagram obtained by the scribed circle method. | Press Formability of Face-Centred Cubic Metals at Cryogenic Temperatures | 10.1007/978-1-349-05172-4_27 |
1979-11-01 | Non-steady-state mass transfer in materials with large outgassing, used for the heat insulation of cryogenic vessels, was investigated experimentally and theoretically. | Mass transfer in evacuation of materials with large outgassing | 10.1007/BF01102227 |
1979-11-01 | Apparatus for calibrating and checking gas-content gauges for bubbling two-phase cryogenic flows | 10.1007/BF00827893 | |
1979-08-01 | Modeling of nonstationary regimes of two-stage cryogenic refrigeration units | 10.1007/BF01174834 | |
1979-08-01 | Increasing the efficiency and reliability of a helium cryogenic assembly as a result of improving the turboexpander unit | 10.1007/BF01174830 | |
1979-07-01 | Results of investigations on the production of cryogenic helium cycles with minimal losses due to irreversibility of the thermodynamic processes are elucidated. | Cryogenic helium cycles with minimal losses due to irreversibility of the thermodynamic processes | 10.1007/BF00861321 |
1979-07-01 | Creep of cryogenic steels and alloys | 10.1007/BF00703668 | |
1979-05-01 | An investigation has been made to improve the low temperature mechanical properties of Fe-8Mn and Fe-12Mn-0.2 Ti alloy steels. A reversion annealing heat treatment in the two-phase (α + γ ) region following cold working has been identified as an effective treatment. In an Fe-12Mn-0.2Ti alloy a promising combination of low temperature (-196°C) fracture toughness and yield strength was obtained by this method. The improvement of properties was attributed to the refinement of grain size and to the introduction of a uniform distribution of retained austenite (γ). It was also shown that an Fe-8Mn steel could be grain-refined by a purely thermal treatment because of its dislocated α martensitic structure and absence of ε martensite. As a result, a significant reduction of ductile to brittle transition temperature was obtained. | The improvement of cryogenic mechanical properties of Fe-12 Mn and Fe-8 Mn alloy steels through thermal/mechanical treatments | 10.1007/BF02658317 |
1979-03-01 | Tensile specimens machined from metal-matrix, oriented-fiber composites (aluminum alloy reinforced with high strength stainless steel wire) were heated to 260°C and cooled in air to produce a tensile residual stress state in the matrix. Some of the test pieces were cooled to the temperature of boiling nitrogen, held at temperature for fifteen minutes, and then air warmed to room temperature. All test pieces were subsequently strain cycled in tension and the resulting stress-strain behavior was recorded. The results indicated cryogenic refrigeration extended the first stage (totally elastic) behavior of these materials. It was shown that the beneficial effects of the cryogenic treatment resulted from an alteration of the residual stress state brought about by plastic flow of the matrix. Finally, it was shown that these effects could be computed by rigorous analytical methods. | The effect of cryogenic cooling on the tensile properties of metal-matrix composites | 10.1007/BF02658344 |
1979-02-01 | Evaluation of the thermal stability of cryogenic vessels cooled by a low-temperature product | 10.1007/BF00768226 | |
1979-01-01 | The design and construction feasibility of cryogenic structures (struts) of laminated composites for superconductive energy storage magnets^1 is considered. Energy storage magnets are in the form of large solenoids in deep underground tunnels with stored energies of 1000 MWh to 10 000 MWh. The composite structures support the large solenoid and transmit the magnetic forces to bedrock. Capital cost considerations dictate the choice of low-cost fiberglass composites. | Laminated Fiberglass Composites for Cryogenic Structures in Underground Superconductive Energy Storage Magnets | 10.1007/978-1-4615-7522-1_25 |
1979-01-01 | Cryogenic Engineering | 10.1007/978-1-4684-3620-4_11 | |
1979-01-01 | In recent years more emphasis has been placed on the analytical potential of Secondary Ion Mass Spectrometry (SIMS) for the study of organic materials [1,2,3]. We wish to report on static SIMS experiments on a few simple molecules condensed on a copper substrate held at low temperatures. For the experiments we used an Extranuclear Inc., quadrupole massfilter equipped with a Bessel box type energy filter. The bandwidth of the ions accepted in the massfilter was set at 1 eV. Our ion gun is differential pumped and during the experiments a pressure in the 10^−9 torr range could easily be maintained in the main chamber. Our primary ion beam current density was between 1 and 10 nA/cm^2 and the beam energy was varied between 500 and 5000 eV. As primary ion we used He^+,Ne^+, Ar^+, Kr^+, and Xe^+. The nature of our samples made it necessary to use an electron floodgun to compensate for charge buildup on the sample. The energy of the flooding electrons was kept below 7 eV. In all the experiments the temperature of the sample was held at 15°K. In Fig.1 the positive SIMS spectrum of neat methane using a 1 keV Ne^+ beam shows fragments up to C_11. | Secondary Ion Mass Spectrometry of Small Molecules Held at Cryogenic Temperatures | 10.1007/978-3-642-61871-0_87 |
1979-01-01 | Flux-jump stabilized superconducting magnets are usually impregnated with epoxy to prevent wire movement and enhance stability. Hoop stress experienced by the windings when the magnet is energized would otherwise cause wire movement, leading to localized heating and, quite probably, thermal runaway. | Effect of Strain on Epoxy-Impregnated Superconducting Composites | 10.1007/978-1-4615-7522-1_20 |
1979-01-01 | A technological assessment of long distance transport of natural gas in liquefied form was carried out for the Government of Canada, Department of Energy, Mines and Resources.^1 This was done to determine its viability as an alternative to vapour phase pipelines, with special application for use in the Arctic. | An Outline Design for a Cryogenic Internally Insulated Liquefied Natural Gas Pipeline for Arctic Gas Recovery | 10.1007/978-1-4615-7522-1_29 |
1979-01-01 | Superconductive magnetic energy storage (SMES) units are large potential users of fiberglass reinforced polymer matrix composites. A 1000 MWh unit would require 1.6 Gg of material.^1 The superconducting magnet requires low thermal conductance structural supports to transmit the magnetic loads from the 1.8 K conductors to the room temperature bedrock. In particular, it needs support struts with a high strength to thermal conductivity ratio, but low elastic modulus and a low strength to weight ratio are quite acceptable. This is unlike many aerospace applications. The large mass of material needed for struts necessitates the use of easily obtainable low-cost materials. This generally means that commercially fabricated composites will be used. The total capital cost must be balanced against operating cost. | Compressive Fatigue Tests on a Unidirectional Glass/Polyester Composite at Cryogenic Temperatures | 10.1007/978-1-4615-7522-1_18 |
1979-01-01 | Large high-pressure vessels designed for ambient or high temperatures are not presently capable of containing gaseous helium at equivalent pressures when at cryogenic temperatures. Problems associated with achieving and maintaining high pressures at cryogenic temperatures as they involve seal designs were studied. The purposes of this study were (1) to identify suitable materials and develop a seal for cryogenic applications at pressures to 4080 bars (60,000 psi)* and (2) to identify some factors that affect seal performance and reliability for cryogenic pressure vessels. To accomplish this, the seal study was divided into three phases; 51 seal configurations were tested. | High-Pressure Cryogenic Seals for Pressure Vessels | 10.1007/978-1-4684-7470-1_239 |
1978-11-01 | Effect of cryogenic temperatures on lubricating greases | 10.1007/BF00719515 | |
1978-11-01 | Machine for testing materials for low-cycle fatigue by bending under conditions of low and cryogenic temperatures | 10.1007/BF01160017 | |
1978-09-01 | Accumulation of oxygen in cryogenic storage vessels for biological products | 10.1007/BF01144872 | |
1978-08-01 | Change in the mechanical properties of aluminum alloys AMg6 and 5083 and their welds at cryogenic temperatures | 10.1007/BF01528895 | |
1978-08-01 | A relationship connecting the discharge of the gas-cooling cryogenic flow inlets to the discharge of the gas returning in the reverse flow is obtained, for which the cold-productivity of the refrigerator, which is required, is a minimum. | Optimal gas discharge through cryogenic flow inlets in refrigerator cooling of superconducting magnetic systems | 10.1007/BF00860212 |
1978-07-01 | Models are proposed for the heat transfer of an ac conductor cooled by a cryogenic liquid. On the basis of numerical solutions, various thermal situations are analyzed. | Models of heat transfer of a cooled ac conductor | 10.1007/BF00866012 |
1978-06-01 | Device for connecting flexible metal hoses with vessels for cryogenic liquids | 10.1007/BF01146832 | |
1978-05-01 | Technique and equipment for dispersion analysis of cryosols and suspended microadmixtures in cryogenic liquids | 10.1007/BF00821073 | |
1978-03-01 | Cryogenic technique in gynecological practice | 10.1007/BF00556572 | |
1978-03-01 | Effect of pressurization by an internal pressure on the cyclic strength of welded cryogenic pipelines | 10.1007/BF01143856 | |
1978-01-01 | In the development of targets for laser fusion, there is considerable interest in producing a uniform spherical shell of liquid or solid deuterium-tritium mixture (1:1 ratio). It is felt that fuel in this form, compressed and heated by laser beams, would give optimum energy yield [^1,2]. Fabrication of this target begins with selection of glass microballoons, 80 to 100 μ m in diameter and 1 to 2 μ m in wall thickness for uniformity in diameter and wall. These are filled by diffusion at 400°C and high pressure and rapidly cooled to room temperature to entrap the gas. Various fills have been used: D_2, T_2, and D—T, ending with 50 to 190 atm at 300 K, which result in upper condensation temperatures of 29 to 38 K. If all the fuel is condensed uniformly on the inner surface of the container, the solid layers are calculated to be 0.5 to 2.1 μ m thick. | Development of Cryogenic Targets for Laser Fusion | 10.1007/978-1-4613-4039-3_84 |
1978-01-01 | The ultimate performance from infrared bolometers under low-background radiation conditions is obtained when they are operated at the lowest possible temperatures. This paper presents the results of a high-altitude balloon flight test of a He^3 cryostat recently developed for the cooling of bolometers in balloon-borne experiments in astronomy and aeronomy. Because of its small size, weight, and freedom from restrictions on its movement, it may prove useful for a variety of other experiments. | Test Flight Results of a Balloon-Borne He^3 Cryostat | 10.1007/978-1-4613-4039-3_79 |
1978-01-01 | Shells used as laser-fusion targets [^1] (both glass and polymer) are filled with deuterium or a mixture of deuterium and tritium by in-permeating the fuel gases through the shell walls [^2]. In the case of glass shells, the in-permeation is accomplished at elevated temperatures (i.e., T≥ 300°C), and upon completion of the filling operation these shells are returned to room temperature. Because of the use of glasses with relatively low permeability, the shells may be stored at room temperature for a year or more without a measurable decrease in pressure. However, because at room temperature the hydrogen isotopes readily permeate the polymers, fuel will normally escape from a polymeric shell before the shell can be mounted and irradiated by the laser. In addition to this relatively high permeability, a second set of problems results from the mechanical properties of the polymeric shells. | Cryogenic Handling of Polymeric Laser-Fusion Pellets | 10.1007/978-1-4613-4039-3_87 |
1978-01-01 | Considerable quantities of low-thermal-conductance, high-load-carrying strut material are needed for large magnet systems such as the Wisconsin Superconductive Energy Storage Magnet [^1,2]. For this magnet, struts are required which can carry the high compressive loads from the magnet coils at 1.8 K to the room-temperature bedrock. The major refrigeration cost is due to the heat leak through these struts; therefore, it is desirable to minimize their thermal conductance. Fiber-reinforced polymer matrix composites are a logical choice because of their low thermal conductivity-to-strength ratio [^3]. The large mass of material (1.6 × 10^6 kg for a 1000-MWh I-C Reference Unit) needed for struts necessitates the use of easily obtainable low-cost materials. This generally means that commercially fabricated composites will be used. | Compressive Strength of Glass-Fiber-Reinforced Composites at Room Temperature and 77 K | 10.1007/978-1-4613-9853-0_29 |
1978-01-01 | Turn-to-turn electrical shorts in a superconducting magnet can occur during coil winding or coil assembly under compression. Shorts may also appear due to additional magnetic pressure during energizing of the magnet. During the fabrication of the U. S. Superconducting Magnet System for the bypass loop of the U-25 MHD facility [^1], a short was detected in the inner layer at the high-field region. | Effects of Electrical Shorts on Cryostatic Stable Superconducting Magnets | 10.1007/978-1-4613-4039-3_26 |
1978-01-01 | The pulsed carbon monoxide laser is a very promising candidate for laser induced chemistry because it is emitting laser light on many lines between 4.8 and 5.8 μm. In this spectral range many interesting chemical compounds can be vibrationally excited as e.g. ketones, olefines, imines and metal carbonyls. | A Simple High Energy TEA CO Laser | 10.1007/978-3-540-35942-5_22 |
1978-01-01 | For several years work has been under way at Brookhaven National Laboratory to develop an ac superconducting power transmission line. The current design considers a flexible, force-cooled cable using Nb_3Sn superconducting tapes wound in the form of a double helix [^1]. Although Nb_3Sn can now be fabricated with the low ac losses required for ac power transmission [^2–5], the task of effectively incorporating this compound in a conductor to be wound in a coaxial cable remains. Conductor designs which incorporate a thin Nb tape (∼20 µm thick) reacted to form Nb_3Sn layers on each side (∼5 µm each) have been described in a recent review article [^2]. The Nb_3Sn-Nb-Nb_3Sn composite is clad either symmetrically with ∼30 µm of copper on each side or asymmetrically with ∼50 µm copper on one side and ∼20 µm stainless steel on the other. The copper is required for stabilization and the stainless steel provides additional strength which may be required during cable winding, handling, and cooldown. | Nb_3Sn Conductors for AC Power Transmission: Electrical and Mechanical Characteristics | 10.1007/978-1-4613-9853-0_50 |
1978-01-01 | Fusion reactors and large experiments will require extensive developments to meet their needs for pulsed energy. Nondissipative, superconducting inductive energy storage for pulsed power will be needed both for high- ß theta-pinch [^1] and for low- ß tokamak ohmic heating [^2–4] systems to achieve overall power balance. The toroidal reference theta-pinch reactor (RTPR) would require about 60 GJ delivered in 30 msec, the linear theta-pinch fusion/fission hybrid reactor needs about 25 GJ in 2 msec [^5], and a linear reactor may require about 10 GJ in 1 msec. The ohmic heating coils in current U. S. designs of tokamak EPRs have about 1 to 2 GJ of stored energy, and the storage currents must be reversed in 0.5 to 2 sec to induce plasma current [^6–10]. | 0.54-MJ Superconducting Magnetic Energy Transfer and Storage | 10.1007/978-1-4613-4039-3_6 |
1978-01-01 | In another paper [^1], the results of specific heat measurements on 10 metallic alloy samples were considered. This paper discusses specific heat measurements on four composite (i.e., fiber-reinforced) materials, one of which (boron/aluminum) is essentially metallic, and the other three are resin-based. The resin-based composites are more difficult to measure than metallic samples, and in analyzing the resulting data, the assembling of an appropriate fitting function is more complicated. As with the Fe—Ni base alloys [^1], specific heats were measured in the low-temperature range (3 to 20 K) and at the intermediate temperatures ∼80 K and ∼300 K. Because of difficulties associated with long thermal-relaxation times at these temperatures, considerable experimental scatter is associated with the results for the resin-based specimens. | Specific Heats of Some Cryogenic Structural Materials II—Composites | 10.1007/978-1-4613-9853-0_31 |
1978-01-01 | Although a number of successful magnets have been wound from Nb_3Sn superconductors, the low ductility of these conductors has prompted investigations of the mechanical properties of composites containing Nb_3Sn. Various measurements have indicated that critical currents ( I _ c ) of multifilamentary Nb_3Sn superconductors are degraded irreversibly at elongations from 0.4 to 3% [^1–6]. For practical monolithic conductors, the maximum safe bending strain (for handling reacted conductors and winding magnets without degradation of I _ c ) is about 0.6% [^7] | Mechanical Properties of Multifilamentary Nb_3Sn Superconductors | 10.1007/978-1-4613-9853-0_36 |
1978-01-01 | Comparison of cryogenic supply systems of surgical instruments for local destruction of extensive lesions of biological tissue | 10.1007/BF00557017 | |
1978-01-01 | The steels commonly specified for structural applications at LNG and lower temperatures, 9% Ni steel, austenitic stainless steels, and Invar alloys, all have a relatively high nickel content. While the nickel addition contributes significantly to good low-temperature properties of these alloys, it also adds substantially to the cost. Consequently, there is incentive to develop techniques for reducing or eliminating the nickel content of cryogenic steels while retaining good cryogenic properties. Steels containing 5 to 6% nickel were recently introduced in the United States [^1] and in Japan [^2] in response to this need. Further decreases in the nickel content would be desirable. | Fe-Mn Alloys for Cryogenic Use: A Brief Survey of Current Research | 10.1007/978-1-4613-9853-0_8 |
1978-01-01 | The goal of the laser fusion program is the production of energy from nuclear fusion reactions induced by focusing powerful laser beams on very small targets that contain a mixture of deuterium and tritium (DT) fuel. If the laser beams can sufficiently compress and heat the target in a short enough time, the fuel will undergo nuclear fusion to produce more energy than was put into the system. Target design is an important part of this laser fusion program. Target geometries ranging from bare, hollow, glass, or metal microspheres to a multilayered or even multishell design are currently of interest [^1,2]. One feature common to the various target designs is the fuel core, the hollow sphere containing the DT fusing fuel. This core is typically a 100- μ m-diameter glass microballoon (GMB) having a wall thickness of about 1 μ m. The GMB is filled with up to 10 ng of DT, which corresponds to a room-temperature pressure of up to 10 MPa (100 atm). | A New Method for Producing Cryogenic Laser Fusion Targets | 10.1007/978-1-4613-4039-3_83 |
1978-01-01 | Refrigeration without lubrication, vibration, and noise has heretofore been accomplished in at least three distinct forms; thermoelectric junctions that pump heat across a semiconductor PN junction [^1], ammonia-water systems that remove heat in an adsorption-percolation-condensation-evaporation cycle [^2], and chemisorption systems that exchange hydrogen from lanthanum-nickel and other metal hydrides to develop a pressure difference for circulation of hydrogen gas in a 20-K refrigerator [^3,4]. While technically sound, these systems have a mix of advantages and disadvantages that render them unsuitable as the basis for complete cryogenic refrigeration cycles. | Cryogenic Refrigeration Concepts Utilizing Adsorption Pumping in Zeolites | 10.1007/978-1-4613-4039-3_54 |
1978-01-01 | The defining points of the International Practical Temperature Scale issued in 1968 (IPTS-68) [^1] involve five boiling points and three triple points from 13.81 to 273.15 K. Shortly after its adoption, the many fixed points involved in the new definition were found to be quite difficult to realize even for national laboratories; KOL, NPL, NRC, and PRMI* have only recently realized all the fixed points. In the course of the studies in these and other laboratories, the information on fixed points has greatly increased since 1968. Boiling-point temperatures appeared to be affected by impurities in the gas sample; thus, the dew point was sometimes preferred [^2]. In addition, the measurement of pressure was necessary, and for some gases this had to be performed with a high degree of accuracy. At the same time, careful studies first made by Ancsin [^3] showed that with a calorimetric method it was possible to obtain excellent results with triple points (t.p.); as a consequence, the triple point of argon (83.798 K) was introduced in the amended 1975 version of the IPTS-68 as an alternative to the normal boiling point (n.b.p.) of oxygen (90.188 K). | Alternate Sets of Fixed Points for Simplified Realizations of IPTS-68 | 10.1007/978-1-4613-4039-3_61 |
1978-01-01 | The design of a circular, cryogenically stable high-current Al—TiNb composite conductort is presented (see Figs. 1 and 2), such that the extremely soft but highly desirable high-purity aluminum is tightly and completely confined inside thin shells of high-strength aluminum. The conductor is also reinforced with high strength webs, which provide axial, circumferential, and flexural strength. The conductor is torsionally stiff and structurally self-supporting; it accommodates discrete, instead of continuous, supports, allowing for cooling along its entire length. Such open surface cooling provides for high current density in the aluminum stabilizer. Criteria are given for the separation between adjacent windings in a magnet which would allow for adequate cooling. | High-Current Al-TiNb Composite Conductor for Large Energy Storage Magnets | 10.1007/978-1-4613-9853-0_41 |
1978-01-01 | Laser-induced fusion has been demonstrated by illuminating deuterium—tritium-filled spherical glass shells with a Nd:glass laser [^l,2]. These shells were filled with DT fuel mixtures to pressures from 10 to 150 atm,‡ and have had diameters in the range of 40 to 150 μ m. The DT fusion reaction occurs as the irradiated shell implodes, compressing the fuel gases which are inertially confined at the high temperatures and densities required to initiate the reaction [^3,4]. Theoretical considerations have suggested that the yield of thermonuclear neutrons can be enhanced if the fuel is condensed in a uniform layer on the inner surface of the shell at the time it is irradiated. [^5]. This paper describes one approach developed to enable laser illumination of cryogenic fuel configurations with the fuel condensed in either liquid or solid layers. | Point-Contact Conduction-Cooling Technique and Apparatus for Cryogenic Laser Fusion Pellets | 10.1007/978-1-4613-4039-3_86 |
1978-01-01 | Evacuated porous materials have seen wide use as cryogenic insulations for many years [^1,2] and numerous studies [^2–9] have addressed the technology of heat transport in these powder, fiber, foam and multilayer types of insulation. Although they are comprised of a wide variety of materials, the mechanisms of heat transfer by radiation and solid conduction within the media are well understood. However, when a fluid is present in the void spaces between and/or within particles the heat transport is less well defined, particularly at cryogenic temperatures and in the pressure range intermediate to free molecular and continuum regimes [^10–12]. | Heat Transfer in Microsphere Insulation in the Presence of a Gas | 10.1007/978-1-4615-9083-5_39 |
1978-01-01 | Multifilamentary Nb_3Sn superconductors are presently manufactured either by diffusing tin to niobium filaments from the surface of a copper matrix strand, or by providing tin in a tin—bronze matrix for reaction with the filaments. This paper describes recent work using both of these processes. A variation of the externally diffused conductor, a standard product at IGC, is described. The copper—13 wt.% tin bronze conductors and coils, which have been fabricated as part of the Manufacturing Technology Program sponsored by the Air Force Materials Laboratory at Wright-Patterson Air Force Base (WPAFB) are reported [^1]. Experimental work in consideration of a third, high-tin bronze type of conductor has been done by Petrovich and Zeitlin [^2]. | Performance of Multifilament Nb_3Sn Conductors for High-Field Applications Prepared by Competing Processes | 10.1007/978-1-4613-9853-0_43 |
1978-01-01 | Nickel-containing steels are frequently selected for use at cryogenic temperatures because of their excellent toughness or strengths. For example, 304 stainless steel containing 8% Ni is characterized by very high toughness at cryogenic temperatures, but has relatively low strength. In contrast, 18% Ni, 200 grade, maraging steel is characterized by very high strengths at cryogenic temperatures, but with a penalty of reduced toughness. Similarly, 9% Ni steel is characterized by good toughness and moderate strength at cryogenic temperatures, while 9Ni-4Co steel has greater strength, but substantially lower toughness in the same temperature range. | Cryogenic Properties of a New Tough-Strong Iron Alloy | 10.1007/978-1-4613-9853-0_11 |
1978-01-01 | Energy conservation and ecological concerns are vital considerations in any energy development program. The magnetohydrodynamic (MHD) approach to electric power generation offers a unique combination of high-efficiency large-scale power generation and the capability of meeting air quality standards even when high-sulfur coal is used as fuel. The role of MHD power generation as an important area for scientific and engineering investigations with potential global significance in the field of energy is underlined by a large-scale cooperative program between the United States and the Soviet Union. | Commercial Realization of MHD—A Challenge for Superconducting Magnets | 10.1007/978-1-4613-4039-3_1 |
1978-01-01 | Past experience has shown that cryogenic fluids can be used safely in industrial environments as well as sophisticated laboratories, provided that all facilities are properly designed and maintained, and personnel handling these fluids are adequately trained and supervised. There are many hazards associated with cryogenic fluids. However, the principal ones are those associated with the response of the human body and the surroundings to these fluids and their vapors, and those associated with reactions between these fluids and their surroundings. | Safety with Cryogenic Systems | 10.1007/978-1-4613-4039-3_90 |
1978-01-01 | The loss of ductility of iron and other b.c.c. metals in the cryogenic temperature range is thought to be caused by a rapid decrease in dislocation mobility with decreasing temperature. This is indicated by the large temperature dependence of yield stress at cryogenic temperatures. Mechanisms responsible for this phenomenon have been disputed among researchers [^1]. In iron, the rate-controlling mechanism for low-temperature deformation appears to be the lattice resistance to screw dislocation motion. The surface film softening (SFS) discussed in this chapter is the most recent observation in support of this theory. In addition, the SFS phenomenon suggests a method to improve the ductility of b.c.c. metals in the cryogenic temperature range. | Surface Film Effects on Deformation Behavior of Iron Single Crystals at Cryogenic Temperatures | 10.1007/978-1-4613-9853-0_13 |
1978-01-01 | Cryogenically cooled infrared telescopes are being developed in the United States and in Europe for flight on the NASA Space Shuttle and the European Spacelab, respectively. The latter will carry such telescopes among other experiments into orbit by the Shuttle some time in 1980. Infrared telescopes on Spacelab will enable astronomers to observe the sky without any atmospheric disturbances. They are also of interest for investigations of the terrestrial atmosphere. To be effective a telescope for the far-IR region must be cooled down to at least 10 K. Many IR detectors, however, require temperatures down to 0.3 K in order to achieve high detection sensitivity. | Liquid Helium-Cooled Infrared Telescope for Astronomical and Atmospherical Measurements from Spacelab | 10.1007/978-1-4613-4039-3_77 |
1978-01-01 | An initial investigation of the cryogenic fracture behavior of a solution-treated and double-aged Inconel 718 nickel-base superalloy revealed rather poor ductility and fracture properties. This low ductility and fracture toughness was attributed to a pronounced contiguous grain boundary metal carbide network, which formed during the original mill processing of the forging billet stock and was not removed by the standard 1255 K (1800°F) solution treatment. Therefore, either a higher solution treatment temperature to dissolve these carbides or a final working treatment, followed by heat treatment to break up this network and recrystallize the entire structure, was deemed necessary to achieve optimum cryogenic material properties. Consequently, in an attempt to eliminate or reduce the influence of these carbides, Inconel 718 was given a 1339 K (1950°F) solution treatment followed by cold working and then subjected to one of three heat treatment schedules: (1) 1255 K (1800°F) solution treat and double age; (2) 1399 K (1950°F) solution treat and double age; and (3) double age. Tensile, fracture toughness, and fatigue crack growth rate properties were developed for all three processing/heat treatment conditions, plus the original solution-treated and double-aged Inconel 718. Tensile and fracture toughness properties of a 1255 K solution-treated and double-aged Udimet 718 alloy, comparatively carbide free, were also determined. | The Influence of Processing and Heat Treatment on the Cryogenic Fracture Mechanics Properties of Inconel 718 | 10.1007/978-1-4613-9853-0_19 |
1978-01-01 | The measurements discussed in this paper are part of a comprehensive experimental program to obtain orthobaric liquid densities for the major components of LNG and their mixtures using a magnetic suspension densimeter. The present measurements on methane plus ethane were made to evaluate vapor recirculation as a method of liquid mixing and the consistency of liquid-phase compositions determined by analysis of liquid samples. The results demonstrate the feasibility of using a magnetic suspension densimeter to obtain accurate isothermal phase equilibria and liquid density data simultaneously, with compositions determined by chromatographic analysis. | Liquid Mixture Excess Volumes and Total Vapor Pressures Using a Magnetic Suspension Densimeter with Compositions Determined by Chromatographic Analysis: Methane Plus Ethane | 10.1007/978-1-4613-4039-3_73 |
1978-01-01 | A large cryogenic tensile test apparatus has been constructed at the Lawrence Livermore Laboratory (LLL) as part of the Nb_3Sn conductor program. This equipment was designed so that mechanical measurements can be made at 300, 77, or 4.2 K and critical current can be measured under simulated operating conditions as a function of the strain on large, prototype conductors for fusion magnets. The maximum operating parameters of the machine are: load of 223 kN, magnetic field of 12 T, and conductor current of 10 k A. Some of the unique features of this equipment will be described and preliminary mechanical and superconducting data on sample Nb_3Sn conductors discussed. | Evaluation of Large, Multifilament Nb_3Sn Conductors with a New 12-Tesla Tensile Test Apparatus | 10.1007/978-1-4613-9853-0_34 |
1978-01-01 | Leidenfrost film boiling data of discrete masses of a cryogenic fluid were first reported by Keshock and Bell [^1,2]. These authors attempted to correlate their cryogenic data using the equations developed by Baumeister et al . [^3] from standard laminar film boiling theory. This theory had been found to successfully correlate data for conventional fluids such as water, ethanol, benzene, and carbon tetrachloride. However, Keshock and Bell found the measured drop vaporization times were as much as 30% shorter than predicted by the equations developed by Baumeister et al . [^3] even after the contributions of heat transfer by radiation and free convection to the droplet’s upper surface were considered. To account for this discrepancy, the effects of ice contamination and mass transfer from the upper surface of the drop were experimentally investigated in this study. In particular, ice formation in the drop from contamination was found to significantly affect the vaporization times of liquid nitrogen drops. | Effect of Ice Contamination on Liquid-Nitrogen Drops in Film Boiling | 10.1007/978-1-4613-4039-3_36 |
1977-12-01 | Mechanical properties of alloy 01205 at cryogenic temperatures | 10.1007/BF00670258 | |
1977-11-01 | 1. Investigations of the cyclic strength of materials with cooling to 4.2°K made on a UNV-5 machine make it possible to reduce by 50–70% the time for testing 16 samples in comparison with the time required for testing the same number of samples on previously known machines. 2. The consumption of liquid helium is reduced by 50% for this machine as a result, of eliminating losses of coolant in changing samples. 3. Uniformity in test conditions provides reliability in the results and the number of samples tested without intermediate disassembly makes it possible to use the data obtained for drawing the complete portion of the fatigue curve in the multicycle area. | Machine for fatigue tests of materials at cryogenic temperatures | 10.1007/BF01528869 |
1977-10-01 | Effect of sharp notches and cracks on the transition to quasibrittle fracture of structural metals ductile at cryogenic temperatures | 10.1007/BF01528915 | |
1977-09-01 | Experimental results on the thermal conductivity of silica gels, including metallized gels, at cryogenic temperatures are presented. | Thermal conductivity of certain adsorption materials at the temperatures 10–200°K | 10.1007/BF00860546 |
1977-09-01 | Determining the conditions of quasibrittle failure of constructional metals which are ductile at cryogenic temperatures | 10.1007/BF01528590 | |
1977-09-01 | Striate cortex in unanesthetized, paralyzed rhesus monkeys was cooled to assess the effects of temporary blockade of corticogeniculate fibers on responses of lateral geniculate neurons. Most neurons recorded under the thermode became inexcitable on cooling. After the onset of cooling, superficial layers became inexcitable before deep layers, and at a time when superficial activity was blocked, deep neurons were still orientation specific and retained this property until they themselves became inexcitable. Twenty-eight percent of the geniculate neurons projecting to cortex under the thermode were judged to be affected by cortical blockade, generally showing increases in driven and spontaneous activity. Cooling produced changes in the scale of response magnitude, rather than in the timing of impulse discharge, as evaluated by response time histograms. Responses evoked by bars or edges or by flashing spots were equally affected. The changes of activity produced were generally small and frequently difficult to differentiate from spontaneous shifts in excitability. In contrast, a visually driven inferior pulvinar neuron with a receptive field in the cooled area was strongly affected by cortical blockage, and driving quickly and completely returned soon after the cortex was rewarmed. It therefore appears that the method of blockade was effective but incapable of producing large effects in geniculate neurons. This suggests that cortical control may be inherently weak in the immobilized animal or that the distribution of activity between excitation and inhibition is equally balanced. | Effects of cryogenic blockade of visual cortex on the responses of lateral geniculate neurons in the monkey | 10.1007/BF00236182 |
1977-05-01 | Nonstationary heat and mass transfer in laminar-vacuum insulations are investigated experimentally and theoretically in application to their operating conditions in cryogenic vessels. | Heat and mass transfer in laminar-vacuum insulation | 10.1007/BF00860599 |
1977-04-01 | Activity of adsorbents in the cryogenic purification of hydrogen | 10.1007/BF01144404 | |
1977-04-01 | The results of an experimental study of thermally induced oscillations are presented. Relations are given for the determination of the stability limit and amplitudes of the oscillations. | Thermally induced oscillations of helium in cryogenic apparatus | 10.1007/BF00867034 |
1977-03-01 | 1. Cryogenic applicators having heat exchangers as thin-walled vessels show no effect from the material on the size of the frozen zone. 2. The heat-exchanger material should be chosen on the basis of design considerations, manufacturing convenience, or sterilization requirements. | Effects of heat-transfer material on the working parameters of cryosurgery instruments | 10.1007/BF00556140 |
1977-01-01 | At the present time, the major mechanical properties of structural materials at cryogenic temperatures have been studies of short-term static loading. Both experimental procedures and equipment for testing in static tension, flexure, compression, and shear are well developed and rather efficient for temperatures of liquid nitrogen, liquid hydrogen, and liquid helium. Therefore, the present lack of data on strength and strain behavior of many engineering materials at 4.2 K should be eliminated in the course of time. | Mechanical Property Measurement Techniques of Structural Materials At Cryogenic Temperatures | 10.1007/978-1-4613-9850-9_12 |
1977-01-01 | An electrical insulator in low-temperature equipment is stressed not only by the electrical field but also by mechanical forces, partly due to thermal gradients. At cryogenic temperatures some electrical properties, such as the dielectric losses, may be expected to improve. However, some mechanical properties of the dielectrics may deteriorate and in turn affect their electrical performance. | Surface Flashover Voltage of Spacers in Vacuum at Cryogenic Temperatures | 10.1007/978-1-4613-9850-9_33 |
1977-01-01 | Cellular glass blocks are used as a load-bearing thermal insulation in the base of low-temperature storage tanks and in cryogenic tanks used to store liquid natural gas, oxygen, nitrogen, and ethylene. Approximately 75% of the large, above-ground LNG storage tanks buih since 1958 have utilized cellular glass blocks as the load-bearing insulation. The very early cryogenic tanks in the mid-1950s utilized cellular glass insulation without any capping material. | Cellular Glass Insulation for Load-Bearing Application in the Storage of Cryogenic Fluids | 10.1007/978-1-4613-9850-9_26 |
1977-01-01 | Evacuated uncoated microspheres are a promising insulation for cryogenic systems such as storage and transportation of LNG and onboard storage of cryogenic fuels in aircraft. For these applications the uncoated microspheres offer several advantages over metallized microspheres. Cost, which ranges frotn $2 to $50 per kg, is an order of magnitude less than that of available aluminized microspheres. The thermal performance of the uncoated microspheres is an order of magnitude better than that of metallized microspheres under conditions of moderate compressive loading. Finally, the thin metal coatings may be degraded by exposure to water vapor or certain gaseous species as well as mechanical effects associated with repeated thermal cycling[^1]. | Apparent Thermal Conductivity of Uncoated Microsphere Cryogenic Insulation | 10.1007/978-1-4613-9850-9_28 |
1977-01-01 | Superconducting composites within large-scale magnets can be subjected to high stresses. These stresses arise from several sources, chief among them being the winding tension and prestressing during construction of the magnet, the ther-momechanical forces incurred during thermal cycling to cryogenic temperatures, and especially in large-scale systems, the magnetomechanical forces generated when the magnet is energized. These mechanisms can combine to exert large stresses on the superconducting composite, with magnitudes approaching the ultimate strength of the wire itself [about 10^9 N/m^2 (~150 ksi) for NbTi: Cu composites]. | Effect of Stress on the Critical Current of NbTi Multifilamentary Composite Wire | 10.1007/978-1-4613-9850-9_54 |
1977-01-01 | An application area for cryogenic structural materials requiring immediate attention is superconducting electrical machinery such as the two 5 MVA superconducting prototype generators recently developed by Westinghouse. One of the major candidate structural materials is Inconel X750, which is being utilized for the torque tube, damper shield, outer rotor shell, and stub shafts. The study described in this paper was directed toward (1) defining the microstructural characteristics of X750 and determining the effects of processing on microstructural variables, (2) defining the failure modes of specimens tested at cryogenic temperatures, and (3) estabUshing a correlation between the observed mechanical properties at cryogenic temperatures and microstructural details. | Microstructures of Inconel X750 for Cryogenic Structural Applications | 10.1007/978-1-4613-9850-9_6 |
1977-01-01 | Copper has a higher yield strength than aluminum at low temperatures and therefore has been used for stabilizing material in practically all applications of superconducting composite cable.[^1] Only recently [^2,3] has serious consideration been given to high-purity aluminum; increased availability and decreasing cost have helped to bring about this change. The major disadvantage of aluminum is its low yield strength. According to data assembled by Reed [^4], the flow stress of 99.999 aluminum at 298 K has been reported to be on the order of 6.9 × 10^6 N/m^2 (1000 psi) at plastic strains of 0.001 to 0.01. Aluminum of this purity would be expected to have a residual resistance ratio (RRR ≡ ^R300K/^R4.2K) of less than 1000 [^5] Baylis [^6] suggests that for the design of an aluminum-stabilized tubular superconducting cable a yield strength of 4.48 x 10^7 N/m^2 should be considered. | Electrical and Mechanical Properties of Dilute Aluminum-Gold Alloys at 300, 77, and 4.2 K | 10.1007/978-1-4613-9850-9_57 |
1977-01-01 | Within the High-Temperature Chemistry Group (CMB-3) at Los Alamos Scientific Laboratory hollow micro-targets for fusion experiments are routinely filled with 50–50 DT gas at pressures ranging from 1 to 1000 atm and temperatures of 300–400°C. Li(D,T) targets are also prepared using the exchange of LiD spheres with tritium gas. The gas system has provisions for mixing, purifying (using a uranium-tritide bed), storing, and analyzing (using mass spectrometry) mixtures of DT gas. Although only small amounts of gas are actually used in the filling procedure, the system is capable of handling up to about four moles (90l) total. The highpressure gas is generated using a metal hydride bed which produces the pressure via the decomposition of V(D,T)_2. The pump is considerably more convenient to use than conventional systems and is capable of pumping pressures of up to 1400 atm (20,000 psi). Problems and safety aspects of handling and containing bulk amounts of tritium are discussed. | Tritium Handling and the Preparation of DT-Containing Micro-Targets for Laser Fusion Experiments | 10.1007/978-1-4684-8103-7_18 |
1977-01-01 | The chemical identity of the primary electron acceptor of photosystem I has been an active area of investigation for several years. Early proposals were that a chlorophyll molecule might be involved as a primary acceptor for photosystem I ( Kamen 1961, 1963). The discovery and characterization of a soluble chloroplast iron-sulfur protein, ferredoxin, by Tagawa and Arnon (1962) led to the proposal that this protein functions as the primary acceptor. This view was based largely on the half-reduction potential ( E _m) of −420 mV for soluble ferredoxin at pH 7.0, a value equivalent to that of the hydrogen electrode. | Primary Electron Acceptors | 10.1007/978-3-642-66505-9_10 |
1977-01-01 | The use of superconductors in rotating electrical machinery results in high rotor stresses at cryogenic temperatures, and requires the availability of structural materials that must meet stringent performance requirements. This paper discusses the potential advantages of composite materials for such applications, the range of properties that may be achieved, and some preliminary experimental data that help define that potential. Some of the factors that arise due to anisotropy in terms of a particular design problem are considered. These are related to the example of a torque tube suitable for use in a superconducting ac generator. | Application of Fiber-Reinforced Polymers to Rotating Superconducting Machinery | 10.1007/978-1-4613-9850-9_21 |
1977-01-01 | The Advanced Research Projects Agency is currently supporting research to characterize the properties of various structural materials at liquid-helium temperature. The objective is to obtain design data for superconducting motors and generators. Fiber-reinforced polymer-matrix composites are included in this program because their low thermal conductivity-to-Young’s modulus ratio (k/E) and thermal conductivity-to-strength ratio (k/σ) suggest the possibility of substantial savings in refrigeration cost compared to metal construction. An aluminum-matrix composite is also included because the very high strength-to-density ( σ /ρ) and Young’s modulus-to-density (E ρ/ ) ratios of this electrically conductive material suggest potential applications in components such as the eddy-current damper shield. | Static Tensile Properties of Boron-Aluminum and Boron-Epoxy Composites at Cryogenic Temperatures | 10.1007/978-1-4613-9850-9_22 |
1977-01-01 | The Space Shuttle carries more than 500,000 kg of Uquid oxygen (LO_2) and 100,000 kg of liquid hydrogen (LH_2) propellant. Seals for this main propellant system therefore must provide extremely high reliability under prolonged service at cryogenic temperatures. The chief threat to consistently reliable operation is not the cryogenic service itself, but the 325 K temperature variation encountered during each individual mission. Moreover, this reliability must be sustained during the entire 100-mission/ten-year projected life of the Space Shuttle. | A Promising New Cryogenic Seal Candidate | 10.1007/978-1-4613-9850-9_64 |
1977-01-01 | Advanced cryogenic machinery such as present-generation 5 MVA superconducting generator prototypes[^1,2] contain welded rotor components that experience high rotational stresses at extreme cryogenic temperatures to 4.2 K. To ensure achievement of a reliable failure-safe design of such components, adequate characterization of weldments in specific materials of processed and fabricated conditions representative of those considered for employment in final fabricated hardware must be accomplished. | Evaluation of Inconel X750 Weldments for Cryogenic Applications | 10.1007/978-1-4613-9850-9_8 |
1976-09-01 | Cryogenic apparatus for local freezing and irrigation | 10.1007/BF00558743 | |
1976-09-01 | Procedure for calculating the cooling of cryogenic liquids under a regime of boiling and surface evaporation | 10.1007/BF01153699 | |
1976-07-01 | Alloy AMg5 is more suitable for operation at cryogenic temperatures, since its mechanical properties are superior to those of alloy AMg6. | Mechanical properties of alloys AMg5 and AMg6 at −196°C | 10.1007/BF00703807 |
1976-06-01 | A new material PAM-50 for making guide bushings for cryogenic equipment | 10.1007/BF01154406 | |
1976-05-01 | Cryogenic technique in the treatment of neoplasms of the oral cavity and pharynx | 10.1007/BF00556425 | |
1976-05-01 | Cryogenic instruments for treatment of tumors of the head and neck | 10.1007/BF00556424 | |
1976-05-01 | Device for cryogenic action in subatrophic and atrophic rhinitis and pharyngitis | 10.1007/BF00556423 | |
1976-01-01 | Outlook for using mixture throttling cycles in cryogenic systems | 10.1007/BF01143488 | |
1975-12-01 | Questions of cooling and freezing cryogenic fluids by evacuating the vapor space are examined. The results of a theoretical investigation are compared with experimental data. | Cooling of cryogenic fluids by evacuation of the vapor space | 10.1007/BF00863715 |
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