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2012-06-01
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The Q/U Imaging ExperimenT (QUIET) consists of a pair of radiometer arrays designed to measure the B-mode polarization of the Cosmic Microwave Background (CMB) at 44 GHz (Q-band) and 95 GHz (W-band) with 19 and 90 modules at each frequency. The architecture of both arrays is based on miniaturized coherent polarimeters using High Electron Mobility Transistor (HEMT) chips for amplification; QUIET is the largest coherent microwave array ever fielded. We describe the detector technology used in Phase I of QUIET and our efforts to improve both the W-band module design and the fundamental performance of the HEMT amplifiers. These technology developments have wide application in the field of radio astronomy.
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QUIET Coherent Polarimeter Modules
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10.1007/s10909-012-0467-0
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2012-05-01
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The ideal X-ray camera for astrophysics would have more than a million pixels and provide an energy resolution of better than 1 eV FWHM for energies up to 10 keV. We have microfabricated and characterized thin-film magnetic penetration thermometers (MPTs) that show great promise towards meeting these capabilities. MPTs operate in similar fashion to metallic magnetic calorimeters (MMCs), except that a superconducting sensor takes the place of a paramagnetic sensor and it is the temperature dependence of the superconductor’s diamagnetic response that provides the temperature sensitivity. We present a description of the design and performance of our prototype thin-film MPTs with MoAu bilayer sensors, which have demonstrated an energy resolution of ∼2 eV FWHM at 1.5 keV and 4.3 eV FWHM at 5.9 keV.
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Performance of Magnetic Penetration Thermometers for X-ray Astronomy
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10.1007/s10909-012-0516-8
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2012-05-01
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We are investigating possible technical solutions to minimize the instrumental non X-ray background (NXB) of the X-ray Micro-calorimeter Spectrometer (XMS) for the ATHENA space mission. In the proposed design, XMS will be provided with an anti-coincidence system in order to reject most of the X-ray-like events produced by primary solar and cosmic particles that are expected to populate the L-2 space environment. However, the rejection efficiency of events produced by secondary particles cannot be as good as that of events produced directly by primary particles. Among secondary emitted particles, knock-on electrons have in general a major impact in determining the NXB level of X-ray detectors. For this reason, it may be helpful to adopt some techniques of passive shielding together with the use of the active anti-coincidence. We present preliminary results of a study on polyimide sheets, which could be employed to reduce the fluence of knock-on electrons onto XMS and, more in general, to optimize the design and configuration of X-ray detectors in orbit.
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Kapton Polymeric Films to Shield X-Ray Detectors in Orbit
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10.1007/s10909-012-0523-9
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2012-05-01
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We have built a versatile, compact ^3He test facility to evaluate high-purity Ge (HPGe) SuperCDMS (Cryogenic Dark Matter Search) detectors. We are able to rapidly identify photolithographic or other defects in the thousands of W-Al transition edge sensors (TESs) on each detector and to evaluate the performance of the underlying substrate. We describe our simple method to measure current-voltage ( I – V ) characteristics and R vs. T behavior of HPGe detector crystals with resistances up to 100 GΩ. This provides a way to quickly perform diagnostic physics studies. Results provide critical data that give early warning that a crystal may not be suitable for the SuperCDMS underground experiment. Data from tests made on several kg-scale detectors are presented.
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Temperature Dependent I–V and Resistance Characterization of SuperCDMS Germanium Crystals
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10.1007/s10909-011-0449-7
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2012-05-01
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We report the recent progress on high resolution alpha spectrometers that use metallic magnetic calorimeters. The detector is composed of a meander-type magnetic calorimeter and a gold-foil absorber. The thermal connection between the magnetic sensor and the absorber consists of annealed gold wires. The signal rise time is found to be as expected, with the electronic thermal conductance of gold wires. The energy resolution of a 3.2 keV FWHM is obtained for 5.5 MeV alpha particles with possibilities for further improvements.
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High Energy Resolution Cryogenic Alpha Spectrometers Using Magnetic Calorimeters
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10.1007/s10909-012-0539-1
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2012-05-01
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The next generation of Cosmic Microwave Background (CMB) instruments is dedicated to the detection of CMB B-modes. Instruments like QUBIC (QU Bolometric Interferometer for Cosmology) need components with state of the art properties at high frequency (>90 GHz) to minimise instrumental systematic effects. The Orthogonal Mode Transducer (OMT) is a critical front end component as it allows the discrimination of the polarisation mode of light. Superconducting planar technology seems very promising to improve its properties and miniaturisation. We present a planar superconducting OMT operating in the W band (75–110 GHz). Design and simulations have been performed using CST Studio Suite. Laboratory characterisations were obtained with two different cryogenic setups. We will present these two cryogenic setups, the calibration procedure and preliminary results for two OMT samples.
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W-Band Superconducting Planar Orthogonal Mode Transducer Characterisation
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10.1007/s10909-012-0513-y
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2012-05-01
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A novel type of absorber, dedicated to cryogenic detectors, was conceived to reach a high and constant intrinsic detection efficiency (>98%) for up to 25 keV X-ray photons. The absorber consists of two layers having a different atomic number Z . The role of the first layer (large Z ) is to make negligible the transmission through the absorber; while the second layer (medium Z ) has to reabsorb the escape photons from the first layer. A metallic magnetic calorimeter was realized with an Au-Ag absorber. The required thicknesses of both layers were determined using Monte Carlo simulation of the efficiency. To show the advantages of such a detector, its efficiency and its energy resolution are compared to the efficiency and energy resolution of a gold absorber using a ^241Am source.
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A Novel Type of Absorber Presenting a Constant Detection Efficiency for up to 25 keV X-Ray Photons
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10.1007/s10909-012-0537-3
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2012-05-01
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There is a growing interest in cryogenic calorimeters with macroscopic absorbers for applications such as dark matter direct detection and rare event search experiments. The physics of energy transport in calorimeters with absorber masses exceeding several grams is made complex by the anisotropic nature of the absorber crystals as well as the changing mean free paths as phonons decay to progressively lower energies. We present a Monte Carlo model capable of simulating anisotropic phonon transport in cryogenic crystals. We have initiated the validation process and discuss the level of agreement between our simulation and experimental results reported in the literature, focusing on heat pulse propagation in germanium. The simulation framework is implemented using Geant4, a toolkit originally developed for high-energy physics Monte Carlo simulations. Geant4 has also been used for nuclear and accelerator physics, and applications in medical and space sciences. We believe that our current work may open up new avenues for applications in material science and condensed matter physics.
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Monte Carlo Simulation of Massive Absorbers for Cryogenic Calorimeters
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10.1007/s10909-012-0480-3
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2012-05-01
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Transition edge sensors (TES) are the chosen detector technology for the SAFARI imaging spectrometer on the SPICA telescope. The TES are required to have an NEP of $2\mbox{--}3\times 10^{-19}~\mbox{W/}\sqrt{\mathrm{Hz}}$ to take full advantage of the cooled mirror. SRON has developed TiAu TES bolometers for the short wavelength band (30–60 μm). The TES are on SiN membranes, in which long and narrow legs act as thermal links between the TES and the bath. We present a distributed model that accounts for the heat conductance and the heat capacity in the long legs that provides a guideline for designing low noise detectors. We report our latest results that include a measured dark NEP of $4.2\times 10^{-19}~\mbox{W/}\sqrt{\mathrm{Hz}}$ and a saturation power of about 10 fW.
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Distributed TES Model for Designing Low Noise Bolometers Approaching SAFARI Instrument Requirements
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10.1007/s10909-012-0550-6
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2012-05-01
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Magnetic calorimeters have been under development for over 20 years targeting a wide variety of different applications that require very high resolution spectroscopy. They have a number of properties that distinguish them from other low temperature detectors. In this paper we review these properties and emphasize the types of application to which they are most suited. We will describe what has been learned about the best materials, geometries, and read-out amplifiers and our understanding of the measured performance and theoretical limits. While most magnetic calorimeter research has concentrated on the use of paramagnets to provide the temperature sensitivity, recently magnetically coupled microcalorimeters have been in development that utilize the diamagnetic response of superconductors. We will contrast some of the properties of the two different magnetic sensor types.
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Magnetically Coupled Microcalorimeters
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10.1007/s10909-012-0544-4
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2012-05-01
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A superconducting 119-pole wiggler with a 2.1-T operating field and 30-mm period length, which is intended for use at the ALBA Synchrotron Light Facility (SLF), Barcelona, Spain, has been designed and manufactured at the Budker Institute of Nuclear Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia. The interpole gap and aperture of the beam are 12.6 and 8.5 mm respectively. The total radiation power reaches 16 kW when the current of the 3-GeV electron beam is 0.4 A. In May 2010, after successful testing in Novosibirsk, the wiggler was transported to the ALBA SLF and was retested outside of the storage ring. The maximum field achieved by training of the magnet is 2.26 T. Owing to the improved cryostat structure, the equilibrium operating temperature of the magnet is brought down to 3.5 K, guaranteeing reliable operation of the device and zero liquid helium consumption. The basic parameters of the wiggler’s magnetic and cryogenic systems, as well as the results of their tests, are presented.
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Superconducting 119-pole wiggler with a 2.1-T field and 30-mm period length for the ALBA storage ring
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10.1134/S1027451012050199
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2012-05-01
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Poly(vinyl alcohol) cryogels are obtained and investigated. The cryogels are prepared by freezing an initial polymer solution (100 g/L) at chilling rates of 1.85, 0.3, 0.03, or 0.003°C/min followed by defrosting the frozen (−20°C/12 h) preparations at heating rates of 0.3, 0.03, or 0.003°C/min. It is shown that a noticeable influence of the chilling rate on the rigidity and heat endurance of the gel matrix is observed at very slow regimes of chilling (on the order of thousandths of degree centigrade per minute). One of the reasons for a reduction in the rigidity of resulting cryogels and the fusion enthalpy of the nodes in their supramolecular networks is the formation of a homo-phase hydrogel during the long-term exposure of the concentrated polymer solution to low temperatures prior to the onset of ice crystallization. The effect of the regime of chilling the polymer solution being frozen on the porous structure of cryogels resulting from the thawing of the preparations is ambiguous due to the multifactor character of this effect; therefore, in many cases, well-defined structure-property correlations are not observed.
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Study of cryostructuring of polymer systems. 33. Effect of rate of chilling aqueous poly(vinyl alcohol) solutions during their freezing on physicochemical properties and porous structure of resulting cryogels
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10.1134/S1061933X12030088
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2012-04-01
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In this study, performance of cryogenically treated M35 high speed steel (HSS) twist drills in drilling of AISI 304 and 316 stainless steels was evaluated in terms of thrust force, surface roughness, tool wear, tool life, and chip formation. To present the differences in tool performance between untreated and treated drills, and machinability between AISI 304 SS and AISI 316 SS, a number of experiments were performed at different combinations of cutting speed, and feed rate. As the results of the conducted experiments, the treated drills showed better performance than untreated drills in terms of thrust force, surface roughness, and tool wear and tool life for both types of stainless steels. Tool lives of treated HSS drills in drilling of AISI 304 SS and AISI 316 SS improved 32% and 14%, respectively, when compared with untreated drills. Experimental results also showed that machinability of AISI 304 SS was harder than the machinability of AISI 316 SS.
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Performance of cryogenically treated M35 HSS drills in drilling of austenitic stainless steels
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10.1007/s00170-011-3616-8
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2012-04-01
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We report on a simple, rapid, and efficient method for the extraction of volatile organic compounds (VOCs; including methanol, tetrahydrofuran, 2-hexanone and benzene) from air and solid samples. The system is based on the use of a laboratory-made syringe as the extractor. The needle of the syringe is placed in a chamber cooled by liquid nitrogen. The tip of the needle is placed in the headspace of a vial containing the sample. The headspace components then are circulated with a pump to pass the needle, and this results in freeze-trapping of the VOCs on the inner surface of the needle. The circulation of the headspace components is continued for 15 min, and the syringe is then removed and placed in a GC injector. The effects of volume of the sample vial, headspace flow rate, temperature and time of extraction and desorption were optimized. The overall time for sampling and analysis is <30 min. The method displays an extraction efficiency of >80%) and a good sample transfer efficiency into the GC column due to the absence of a sorbent inside the needle. No carry-over was observed after 30 s desorption at 260 °C. An external standard method was used for quantitative analysis. The relative standard deviation values are below 10% and the limits of detection range from 1.3 to 4.6 ng g^−1. Fiugre The scheme of sorbentless cryogenic needle trap device
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Sorbentless cryogenic needle trap device for the extraction of organic volatile compounds
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10.1007/s00604-011-0753-6
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2012-03-01
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The effect of cryogenic thermocycling treatment on the microstructure, mechanical and cryogenic properties of alloy Mg – 9% Al – 0.9% Zn (AZ91) is studied. Thermocycling in the cryogenic range causes a change in the content and distribution of particles of segregations, which is responsible for improvement of the mechanical properties and corrosion resistance of the alloy.
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Effect of cryogenic thermocycling treatment on the structure and properties of magnesium alloy AZ91
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10.1007/s11041-012-9439-x
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2012-03-01
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The use of superalloy Inconel 718 is increasing in most of the sophisticated applications like aircraft engines, industrial gas turbines, rocket engines, space vehicles, submarines, etc. Hence, in-depth understanding of this material helps to determine the ability of this material to withstand severe conditions of stress, temperature, corrosion, and controls its longevity and reliability. In the present work, an attempt has been made to study the relationship of degree of work hardening and tool life as a function of cutting parameters like cutting speed, feed, depth of cut, untreated tungsten carbide and postcryogenic-treated tool. Work hardening and tool life are the major factors which need to be controlled/improved to enhance the machinability characteristics of superalloy Inconel 718. A significant performance in tool life was observed due to cryogenic treatment given to tungsten carbide tool. Moreover, it was observed that optimized cutting parameters not only minimized/controlled work hardening characteristics but also improved tool life while high-speed machining of Inconel 718.
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Effect of cutting parameters on the degree of work hardening and tool life during high-speed machining of Inconel 718
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10.1007/s00170-011-3529-6
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2012-02-01
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Pedosediments of the Mikulino interglacial paleosol contain information about the Early Valdai cooling. For the periglacial zone of the East European Plain, this period correlating with marine oxygen-isotope stage (MIS) 5d has not been separately distinguished in the known national stratigraphic schemes by the Committee on Stratigraphy and by Velichko with coauthors [4]. However, in the buried erosional landforms of the Mikulino interglacial, the deposits corresponding to this period reach considerable thickness (up to 5 m). They were examined in the key section of the Aleksandrov quarry (Kursk oblast). On the basis of the textural and micromorphological analyses of the Early Valdai pedosediments, the paleoenvironmental reconstruction of the first Early Valdai cooling was performed, and the major supergene processes (pedogenic, cryogenic, erosional, etc.) that shaped the pedosediments were characterized. Four stages of the development of local landscapes were distinguished, and a unidirectional trend for climatic cooling against the background of the complex pattern of climatic moistening in that period was established. Thus, a detailed pattern of the changes in the climate at the turn of the Mikulino interglacial period and the Early Valdai cooling was reconstructed.
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Textures and micromorphology of the early Valdai pedosediments and their importance for the reconstruction of the natural conditions in the period of the first Post-Mikulino cooling (MIS 5d)
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10.1134/S1064229312020111
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2012-02-01
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The effect of refined precipitations and dispersed phases on the toughness of SS400 steel was investigated by rapid tempering with thermomechanical simulation tester, and the electromagnetic induction rapid tempering process was simulated. The conventional tempering and rapid tempering process were proceeded respectively, and both samples were quenched in 10% of agitated iced brine. The tempering temperatures were designed as 560, 620 and 680 °C, respectively. Rapid tempering specimens were heated at a heating rate of 20 °C/s, and all samples of these three tempering temperatures were maintained 30, 40 and 50 s with the Gleeblel500-D tester, respectively. The impact test at — 40 °C were carried out on a Charpy impact machine (CBD-300) with a maximum measurement range of 300 J and the microstructures were analyzed in detail using optical microscope (OM) and scanning electron microscope (SEM). The experiment results show that the upper bainite, martensite and small amount of austenite were obtained in the rapidly quenched samples. In comparison to the conventional process, the matrix microstructure was changed from the larger size and bulk ferrite to the refined banding structure, and the cementites were obviously refined and precipitated inside the grains and along the grain boundaries. The cryogenic impact test implies that the maximum values of impact toughness with holding time of 30 or 50 s are achieved at tempering temperature of 620 °C. Furthermore, a favorite value of impact toughness with holding time of 40 s is available.
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High Temperature Rapid Tempering Process of SS400 Steel With Thermomechanical Simulation Tester
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10.1016/S1006-706X(12)60058-2
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2012-01-01
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This paper aims to present the metallurgical and mechanical characterization of cryogenically treated tungsten carbide (WC–Co) in terms of α-, β-, γ-, and η-phase particles and wear behavior, respectively. The specimens of commercially available uncoated WC–Co in the form of round turning inserts were procured and subjected to cryogenic treatment at two levels −110°C (shallow treatment) and −196°C (deep treatment) of temperature. The microstructures obtained after cryogenic treatments have been characterized with a prominence to comprehend the influence of cryogenic treatment on the nature, size, and distribution of α-, β-, γ-, and η-phase particles as compared to untreated specimen. The mechanical properties such as hardness and wear rate of the specimens have also been compared by performing Rockwell A hardness test and pin-on-disk wear test, respectively. Microstructures, hardness, wear rate, and analysis of worn surface divulge the underlying metallurgical mechanism responsible in improving mechanical properties of the WC–Co.
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Metallurgical and mechanical characteristics of cryogenically treated tungsten carbide (WC–Co)
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10.1007/s00170-011-3369-4
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2012-01-01
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The mechanical behaviour of soil is strongly affected by presence of ice. A constitutive model that incorporates the effect of cryogenic suction and temperature to reproduce the changes in volume, stiffness and strength observed in frozen soils is presented in this work. The model is based on the well know Barcelona Basic Model for unsaturated soils. The model is implemented into the fully coupled finite element program CODE_BRIGHT (Olivella et al., 1996). The capability of the model to describe the behavior of frozen soils has been studied using a series of already published experimental results. The performance of the model is very satisfactory, the main pattern of behavior observed in the tests have been correctly reproduced by the model.
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Mechanical Modeling of Frozen Soils Incorporating the Effect of Cryogenic Suction and Temperature
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10.1007/978-3-642-31343-1_20
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2012-01-01
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Characteristic properties of melt water are formed in course of transformation of its molecular structure in the process of its natural crystallization and subsequent thawing of ice. Melt water is a natural cryogenic resource, which plays a crucial role in the life on the Earth and in the global water resource management. Side by side with technological progress and growth (increase) of the world population, the importance/value (significance) of melt water will grow (be enhanced).
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Melt water as a cryogenic resource of the planet
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10.1134/S1875372812010039
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2012-01-01
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The fire on Mount Parnassus that gave rise to the temple of the Oracle of Delphi was not the only spontaneous outflow of natural gas known to the Ancient World. People in ancient India, Persia and China knew about these fen fires, and there they also used to attribute them to supernatural causes, at least until 500 BC, when the Chinese built the first gas pipelines––using bamboo!––many centuries ahead of the West, as on many other occasions.
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The Sacred Fire
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10.1007/978-88-470-2478-6_6
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2012-01-01
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In order to capture sample preparation images inside a ^3He cryostat via a fibre-optics bundle, a low-temperature white light source was required. High-intensity white LEDs were thus characterized by studying I ( V ) curves and extracting forward voltage drops and operating temperatures at 77 K, 40 K and ∼6 K. Four models were identified as fully functional down to 6 K and images of in-situ sample cleaving in a non-optical ^3He refrigerator were obtained.
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Characterization of White LEDs at Cryogenic (4 K) Temperatures
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10.1007/s10909-011-0415-4
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2012-01-01
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Industrial gases may actually be used as gases, liquids, or cryogenic liquids. Industrial users generally accept them as those gases used primarily in their pure form in large quantities. Most of the gases we consider to be industrial gases have been in use for many years. Processes for the cryogenic separation of the air gases were developed as early as 1895, with commercial production of oxygen beginning in 1902. Nitrous oxide was used as an anesthetic as early as 1799. Carbon dioxide had been identified as a specific substance by 1608. Methane has been used as an energy source since the 1700s. Other gaseous compounds commonly used today for specific manufacturing processes (e.g., electronics/semiconductors, plastics) are discussed in other chapters of this Handbook related to those processes.
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Industrial Gases
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10.1007/978-1-4614-4259-2_27
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2012-01-01
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The acclivitious rise in fuel costs and taxation burden have significantly triggered the scientific community to make substantial changes in the pattern of using renewable energy sources. Gases arising from anaerobic digesters and landfills are widely used as fuel to produce electricity, drive pumps and fire boilers. Biogas can be defined as a biofuel produced by a large number of anaerobic microbial species that inherently possess the capability to ferment organic matter under controlled temperature, moisture and pH to yield a high energy value fuel. Methane and carbon dioxide are the two predominant compounds present in biogas, along with trace quantities of gases such as water vapour, hydrogen sulfide (H_2S), halogenated hydrocarbons, siloxanes, ammonia, nitrogen, and oxygen. Biogas can be used as a fuel for generating heat and electricity and in feed boilers. However, biogas has to be cleaned and upgraded, in order to use it effectively as a fuel or to distribute it in the natural gas grid. Biogas cleaning not only increases the calorific value, but also reduces the risk of corrosion. In this chapter, we outline the importance of biogas from their source, property and application view-points. Secondly, the various physico-chemical and biological methods commonly used for biogas cleaning were reviewed by highlighting the operational advantages and limitations in each case. We have also presented the different strategies adopted to control specific impurities present in biogas, i.e. , CO_2, siloxanes, H_2S and other trace compounds.
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Biogas Technologies and Cleaning Techniques
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10.1007/978-94-007-2439-6_9
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2012-01-01
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It is possible to eliminate the cutting fluids totally in machining. Dry machining refers to machining without using cutting fluids. In this chapter, advantages and limitation of dry machining are described. Technological requirement for dry machining are elaborated.
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Dry Machining
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10.1007/978-1-4614-2308-9_3
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2012-01-01
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High Purity Germanium (HPGe) Detectors are the gold-standard sensor for nuclear spectroscopy applications. In order to make spectroscopic measurements, the detectors must be maintained at cryogenic temperatures. Cryogenic temperatures can be achieved using either liquid nitrogen or piston driven cryocoolers. Because of the bulky and transient nature of liquid nitrogen, the piston driven cryocoolers are preferable for remote, long term, or portable detector applications. These cryocoolers are a promising alternative due to the fact they only require a power source and heat dissipation for continuous operation. A major drawback however is that microphonic noise induced by the vibration of the piston reduces the resolution of the spectroscopic measurements. Passive damping techniques have been applied to this problem, An active damping control system is under development to significantly reduce the vibrations of the cryocooler by adapting to changes in boundary conditions and mass loading through time. Mitigating these vibrations will increase the resolution of portable HPGe detectors and facilitate the identification of nuclear materials.
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Embedded Active Vibration Cancellation of a Piston-Driven Cryocooler for Nuclear Spectroscopy Applications
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10.1007/978-1-4614-2425-3_34
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2012-01-01
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Cryogenic detectors have been important tools in many aspects of science because their sensitivities can provide more than extreme limits of conventional semiconductor based detectors. The sensor developments in cryogenic particle detection are based on the precise measurement of noble properties of condensed matter in low temperatures. The major measurement technologies originate from quantum measurements, phase transitions and superconducting electronics. Although the early developments of cryogenic detectors were initiated by applications to elementary particle physics, they have been adopted in biology, forensics, and security as well as astronomy and nuclear science. Various types of cryogenic detectors cover a wide energy range from THz radiations to hundreds MeV particles. We review the recent development of sensor technologies in cryogenic particle detection. The measurement principles are covered together with applications to elementary particle physics and THz measurement.
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Introduction to Quantum Sensors in Cryogenic Particle Detection
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10.1007/978-94-007-3965-9_23
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2012-01-01
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China’s High-speed steel cutting tools hold a considerable share in the global market. However, the overproduction of low-end HSS tools causes serious resource waste and low efficiency, which has become one of the major problems in the tool industry in China. So a new Surface Modification technology is developed, which can make the low-end HSS tools into the high-end ones. On the analysis of the mechanism of cryogenic and quenching-polish-quenching(QPQ), the cryogenic and QPQ compound treatment are studied by using ϕ 8 HSS(M2) drills. The nitriding layer and the base of the drill bit are Studied and analyzed, and the mechanism of compound treatment is discussed by the technological parameters adjustment and the combination test of cryogenic, nitrogen, tempering procedures, and several analysis methods such as the optics metallographic microscope, the scanning electronic microscope (SEM), X-ray diffraction and micro hardness. The cutting test is done on the drills by cryogenic treatment, QPQ treatment and cryogenic and QPQ compound treatment separately. The results indicates that the cutting life of HSS (M2) drill can be increased dramatically by cryogenic and QPQ compound treatment.
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Effect of cryogenic and QPQ compound treatment on the microstructures and performance of high speed steel
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10.3901/CJME.2012.01.184
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2012-01-01
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This paper presents an innovative prognostics model based on health state probability estimation embedded in the closed loop diagnostic and prognostic system. To employ an appropriate classifier for health state probability estimation in the proposed prognostic model, the comparative intelligent diagnostic tests were conducted using five different classifiers applied to the progressive fault levels of three faults in HP-LNG pump. Two sets of impeller-rubbing data were employed for the prediction of pump remnant life based on estimation of discrete health state probability using an outstanding capability of SVM and a feature selection technique. The results obtained were very encouraging and showed that the proposed prognosis system has the potential to be used as an estimation tool for machine remnant life prediction in real life industrial applications.
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Integrated Approach for HP-LNG Pump Diagnostics and Prognostics Based on Health State Probability Estimation
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10.1007/978-0-85729-493-7_36
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2012-01-01
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After a short review of the history toward high-energy superconducting (SC) accelerators for ion beam therapy (IBT), an overview is given on material properties and technical developments enabling to use SC components in a medical accelerator for full body cancer treatment. The design concept and the assembly of a commercially available SC cyclotron for proton therapy (PT) are described and the potential advantages for applying superconductivity are assessed. The discussion includes the first years of operation experience with regard to cryogenic and magnetic performance, automated beam control, and maintenance aspects. An outlook is given on alternative machine concepts for protons-only or for heavier ions. Finally, it is discussed whether the application of superconductivity might be expanded in the future to a broader range of subsystems of clinical IBT accelerators such as SC magnets for transfer beam lines or gantries.
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Advantages and Challenges of Superconducting Accelerators
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10.1007/978-3-642-21414-1_23
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2012-01-01
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In addition to the morphostructures and climatic conditions, landform evolution on the territory of Slovakia has been heavily influenced by the history of human settlement. Human impact on geomorphic processes has a longer history in the sub-Carpathian lowlands (embracing millennia) than in the Carpathian mountains (measured in centuries). In addition to the predominant gravitational processes (first of all landslides), major natural exogenic geomorphic agents in Slovakia include fluvial processes, soil erosion by water, karst and pseudokarst evolution, aeolian, cryogenic and nival actions. The slopes of agricultural areas were completely remodeled by tillage and water erosion processes. Increased frequency of extreme meteorological-hydrological events during the Little Ice Age resulted in enormous activation of gullying, floods and other precipitation-induced processes. Drastic terrain adjustments, including the levelling of terraced plots, were done due to collectivization in agriculture. The predicted climate change could contribute to an increase in natural hazards, particularly those related to precipitation extremes (floods and landslides).
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Recent Landform Evolution in Slovakia
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10.1007/978-94-007-2448-8_7
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2012-01-01
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The effect of deep cryogenic treatment on the mechanical properties of 80CrMo12 5 tool steel was investigated. Moreover, the effects of stabilization (holding at room temperature for some periods before deep cryogenic treatment) and tempering before deep cryogenic treatment were studied. The results show that deep cryogenic treatment can eliminate the retained austenite, making a better carbide distribution and a higher carbide amount. As a result, a remarkable improvement in wear resistance of cryogenically treated specimens is observed. Moreover, the ultimate tensile strength increases, and the toughness of the sample decreases. It is also found that both stabilization and tempering before deep cryogenic treatment decrease the wear resistance, hardness, and carbides homogeneity compared to the deep cryogenically treated samples. It is concluded that deep cryogenic treatment should be performed without any delay on samples after quenching to reach the highest wear resistance and hardness.
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Effect of deep cryogenic treatment on the properties of 80CrMo12 5 tool steel
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10.1007/s12613-012-0511-8
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2011-12-01
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A single-longitudinal-mode (SLM) operation of a c-cut 1 mm Tm(5%), Ho(0.3%):YAP micro-chip laser pumped by a fiber-coupled diode-laser was reported. Under cryogenic temperature, the output power of 216 mW was obtained under the incident power of 2230 mW, corresponding to the slope efficiency was 13.6%. As much as 133 mW output and slope efficiency of 4.9% was obtained under the pump power of 3000 mW at 291 K. In addition, a maximum SLM output power of 30 mW at wavelength of 2130.56 nm is demonstrated under 77 K.
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Diode pumped operation of 1 mm Tm,Ho:YAP microchip laser
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10.1134/S1054660X11210298
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2011-12-01
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Grinding of low-carbon steel often exhibits severe wheel loading due to the formation of long chips and high adhering tendency of the work material with the grits. Conventional composite-type alumina wheels are commercially utilised for grinding low-carbon steel. However, the actual nature of grit wear cannot be truly understood in a composite wheel. The truing and dressing conditions also have some influences on the wear mechanism. Therefore, in order to explore the wear pattern on a single layer of grits, monolayer brazed cBN, white and grey Al_2O_3 wheels were used in the present study. The grindability of AISI 1020 steel was evaluated under dry, liquid nitrogen and neat oil environments. The surface profile of the workpiece after being ground in each environmental condition was traced with a surface profilometer to reveal the mechanism of grit wear. The post-grinding conditions of the wheels were observed using scanning electron microscopy. The cBN wheel was found to outperform the alumina wheels in terms of grinding forces and grit wear. The wear of the cBN wheel was remarkably arrested with the application of neat oil. On the other hand, large-scale adhesion and breakage of grits in white alumina wheel were observed under cryogenic environment. In fact, the beneficial role of liquid nitrogen could not be realised in reducing grinding forces and grit wear with all the three types of wheel. A lubricating agent like neat oil appeared to be more suitable than cryogenic cooling when grinding low-carbon steel.
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On the grindability of low-carbon steel under dry, cryogenic and neat oil environments with monolayer brazed cBN and alumina wheels
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10.1007/s00170-011-3341-3
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2011-12-01
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Purpose To investigate the effect of cryogrinding on chemical stability of the diuretic agent furosemide and its mixtures with selected excipients. Methods Furosemide was ground at liquid nitrogen temperature for 30, 60, 120 and 180 min. Mixtures of furosemide-PVP and furosemide-inulin (1:1) were milled under cryogenic conditions. Materials were analyzed by XRD, UPLC, MS and NMR. Results Upon increasing the milling time, a significant build-up of an unidentified impurity 1, probably the main degradation product, was noticed. Cogrinding of furosemide with PVP and inulin worsened chemical stabilization of the pharmaceutical. The main degradation product formed upon cryomilling was subsequently identified as 4-chloro-5-sulfamoylanthranilic acid (CSA). Based on some theoretical considerations involving specific milling conditions, the milling intensity and an expected specific milling dose have been calculated. Results indicate that cryogenic grinding is capable to initiate mechanically induced decomposition of furosemide. Conclusions Cryogenic grinding can activate and accelerate not only structural changes (solid state amorphization) but also chemical decomposition of pharmaceuticals. A cryogenic milling device should be considered as a chemical reactor, where under favourable conditions chemical reactions could be mechanically initiated.
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Effect of Cryogrinding on Chemical Stability of the Sparingly Water-Soluble Drug Furosemide
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10.1007/s11095-011-0496-4
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2011-12-01
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The thermal diffusion coefficient, heat capacity, thermal conductivity, and thermal expansion coefficient of Cu_76.12Al_23.88 alloy before and after cryogenic treatment in the heating temperature range of 25°C to 600°C were measured by thermal constant tester and thermal expansion instrument. The effects of cryogenic treatment on the thermal physical properties of Cu_76.12Al_23.88 alloy were investigated by comparing the variation of the thermal parameters before and after cryogenic treatment. The results show that the variation trend of the thermal diffusion coefficient, heat capacity, thermal conductivity, and thermal expansion coefficient of Cu_76.12Al_23.88 alloy after cryogenic treatment was the same as before. The cryogenic treatment can increase the thermal diffusion coefficient, thermal conductivity, and thermal expansion coefficient of Cu_76.12Al_23.88 alloy and decrease its heat capacity. The maximum difference in the thermal diffusion coefficient between the before and after cryogenic treatment appeared at 400°C. Similarly, thermal conductivity was observed at 200°C.
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Effects of cryogenic treatment on the thermal physical properties of Cu_76.12Al_23.88 alloy
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10.1007/s12598-011-0443-x
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2011-12-01
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Successful modeling and/or design of engineering systems often requires one to address the impact of multiple “design variables” on the prescribed outcome. There are often multiple, competing objectives based on which we assess the outcome of optimization. Since accurate, high fidelity models are typically time consuming and computationally expensive, comprehensive evaluations can be conducted only if an efficient framework is available. Furthermore, informed decisions of the model/hardware’s overall performance rely on an adequate understanding of the global, not local, sensitivity of the individual design variables on the objectives. The surrogate-based approach, which involves approximating the objectives as continuous functions of design variables from limited data, offers a rational framework to reduce the number of important input variables, i.e., the dimension of a design or modeling space. In this paper, we review the fundamental issues that arise in surrogate-based analysis and optimization, highlighting concepts, methods, techniques, as well as modeling implications for mechanics problems. To aid the discussions of the issues involved, we summarize recent efforts in investigating cryogenic cavitating flows, active flow control based on dielectric barrier discharge concepts, and lithium (Li)-ion batteries. It is also stressed that many multi-scale mechanics problems can naturally benefit from the surrogate approach for “scale bridging.”
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Surrogate-based modeling and dimension reduction techniques for multi-scale mechanics problems
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10.1007/s10409-011-0522-0
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2011-12-01
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The National Measurement Institute of Australia (NMIA) has developed a vacuum cryostat capable of calibrating precision electronic thermometers with a transfer error less than 2 mK over the range from −202 °C to 250 °C. The calibration of precision temperature measurement probes such as platinum resistance thermometers is usually performed in circulated fluid baths to achieve mK-level calibration uncertainties, and requires the use of several baths to cover the commonly used range of −80 °C to 250°C. Below −80 °C, dry-well systems cooled by liquid nitrogen are available down to −196 °C, but achieve poor uniformity and stability. The increased use of cryogenic preservation in the biomedical area has seen an increase in demand for precision calibration of electronic thermometer systems, in particular, down to a few degrees below the boiling point of nitrogen (−196 °C). This has prompted NMIA to develop a new design of a dry-well calibrator, based around a 380 mm long, 50 mm diameter, oxygen-free copper block insulated by gold-plated radiation and guard shields. Temperatures down to −202 °C are achieved by controlling the flow of liquid nitrogen through a restricting orifice into an evacuated heat exchanger. Computer control of the nitrogen flow and of several immersion heaters achieve a temperature stability of a few mK at all temperatures over the operational range, requiring typically 60 min to equilibrate at each new setpoint. Radiative transfer limits operation to 250 °C where the uniformity is 0.5 mK · cm^−1 (and becoming negligible at lower temperatures). A significant design innovation is the thermometer entry region, which has a purge system to keep the wells free of condensed moisture or atmospheric gases without the need for a seal. As the block is only 50 mm from the face of the cryostat, thermometers as short as 250 mm can be calibrated. The system is now in regular use at NMIA providing fully automated calibrations of precison temperature measurement systems without the need to use multiple temperature enclosures.
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A Cryostat for Automated mK-Level Thermometer Calibrations from −202 °C to 250 °C
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10.1007/s10765-011-1125-5
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2011-11-01
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Induced capillary breakdown of solid and hollow jets of molten metals, alloys, and salts with a melting temperature up to 1600°C is studied by experiment. Granulation technology is developed and specimens of solid and hollow monodispersed granules are obtained. Granules of lead and rare-earth metals have found application in cryogenic technology. Other areas for the use of monodispersed granules are considered.
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Preparation of monodispersed spherical granules from different metals
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10.1007/s11015-011-9461-z
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2011-11-01
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The development of high power cryogenic targets for use in parity violating electron scattering has been a crucial ingredient in the success of those experiments. As we chase the precision frontier, the demands and requirements for these targets have grown accordingly. We discuss the state of the art, and describe recent developments and strategies in the design of the next generation of these targets.
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High power cryogenic targets
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10.1007/s10751-011-0292-x
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2011-11-01
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We report vibrational predissociation spectra of the four protonated dipeptides derived from glycine and sarcosine, GlyGlyH^+•(H_2)_1,2, GlySarH^+•(D_2)_2, SarGlyH^+•(H_2)_2, and SarSarH^+•(D_2)_2, generated in a cryogenic ion trap. Sharp bands were recovered by monitoring photoevaporation of the weakly bound H_2 (D_2) molecules in a linear action regime throughout the 700–4200 cm^–1 range using a table-top laser system. The spectral patterns were analyzed in the context of the low energy structures obtained from electronic structure calculations. These results indicate that all four species are protonated on the N-terminus, and feature an intramolecular H-bond involving the amino group. The large blue-shift in the H-bonded N–H fundamental upon incorporation of a methyl group at the N-terminus indicates that this modification significantly lowers the strength of the intramolecular H-bond. Methylation at the amide nitrogen, on the other hand, induces a significant rotation (~110^o) about the peptide backbone.
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Characterizing the Intramolecular H-bond and Secondary Structure in Methylated GlyGlyH^+ with H_2 Predissociation Spectroscopy
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10.1007/s13361-011-0228-3
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2011-11-01
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X-ray crystallography using synchrotron radiation and the technique of dynamic nuclear polarization (DNP) in nuclear magnetic resonance (NMR) require samples to be kept at temperatures below 100 K. Protein dynamics are poorly understood below the freezing point of water and down to liquid nitrogen temperatures. Therefore, we investigate the α-spectrin SH3 domain by magic angle spinning (MAS) solid state NMR (ssNMR) at various temperatures while cooling slowly. Cooling down to 95 K, the NMR-signals of SH3 first broaden and at lower temperatures they separate into several peaks. The coalescence temperature differs depending on the individual residue. The broadening is shown to be inhomogeneous by hole-burning experiments. The coalescence behavior of 26 resolved signals (of 62) was compared to water proximity and crystal structure Debye–Waller factors (B-factors). Close proximity to the solvent and large B-factors (i.e. mobility) lead, generally, to a higher coalescence temperature. We interpret a high coalescence temperature as indicative of a large number of magnetically inequivalent populations at cryogenic temperature.
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Cryogenic temperature effects and resolution upon slow cooling of protein preparations in solid state NMR
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10.1007/s10858-011-9535-z
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2011-11-01
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Various conditions of heat treatment of low-alloy pearlitic steels, medium-alloy martensitic and pearlitic-martensitic steels, and high-alloy ledeburitic roll steels are studied. Practical recommendations for increasing the quality of roll tools are developed. They consist of the application of cyclic heat treatment, including cyclic subzero treatment. The increase in the service durability of rolls after the implementation of these recommendations under industrial conditions is analyzed.
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Methods for increasing the service durability of cold rolling mill rolls
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10.1134/S0036029511110103
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2011-11-01
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We report on matrix-assisted pulsed laser evaporation (MAPLE) transfer of intact and functional protein molecules from a cryogenic aliquot obtained by freezing a protein-saline buffer solution. Vitronectin (Vn), an extracellular matrix protein with distinctive active domains for cell attachment and signalization, was expelled from frozen targets by KrF* excimer laser irradiation, and then immobilized on substrates. Particulates surrounded by a dense matrix were observed by optical, profilometry and AFM studies. The composition preservation of MAPLE-deposited protein films versus drop-cast films was demonstrated by FTIR and immunostaining studies. The stability and integrity of Vn after transfer was shown by their interaction with human osteoprogenitor cells in which actin filaments stretched across the entire cell area and clear focal points with surface were formed. The absence of detectable degradation of protein structure after MAPLE immobilization could provide benefits to surface functionalization for biomedical applications.
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Thin films of vitronectin transferred by MAPLE
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10.1007/s00339-011-6601-z
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2011-11-01
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In the present work, the performance of cubic boron nitride (CBN) inserts was compared with coated carbide and cryogenically treated coated/uncoated carbide inserts in terms of flank wear, surface roughness, white layer formation, and microhardness variation under dry cutting conditions for finish turning of hardened AISI H11 steel (48–49 HRC). The flank wear of CBN tools was observed to be lower than that of other inserts, but the accumulated machining time for all the four edges of carbide inserts were nearer to or better than the PCBN inserts. Results showed that tool life of carbide inserts decreased at higher cutting speeds. The surface roughness achieved under all cutting conditions for coated-carbide-treated/untreated inserts was comparable with that achieved with CBN inserts and was below 1.6 μm. The white layer formation and microhardness variation is less while turning with cryogenically treated carbide inserts than the CBN and untreated carbide. At low to medium cutting speed and feed, the performance of carbide inserts was comparable with CBN both in terms of tool life and surface integrity.
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Performance evaluation of CBN, coated carbide, cryogenically treated uncoated/coated carbide inserts in finish-turning of hardened steel
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10.1007/s00170-011-3320-8
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2011-10-01
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The processes that proceed in hard alloys under the action of ionizing radiation were studied after cryogenic treatment. Acoustic emission due to the liberation of the energy stored in a lattice was shown to occur upon the irradiation of hard alloys. The nondestructive testing of hard alloys was shown to allow the prediction of the life and behavior of a drilling tool under different types of treatment.
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Radiation nondestructive testing of structural modifications of hard alloys after cryogenic treatment
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10.1134/S106183091110010X
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2011-10-01
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The cryogenic ground support equipment (CGSE) is an important part of Alpha Magnetic Spectrometer-02 (AMS-02) experiment which is a particle physics experiment. CGSE is used to cool down the superconducting magnet of AMS-02 to its operating temperature of 1.8K and to fill the magnet helium tank with superfluid helium. This paper introduces the control system of CGSE and presents the performance of the system.
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Control system design and test for cryogenic ground support equipment
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10.1007/s12204-011-1185-5
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2011-09-01
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Seat tightness at the fully shut position should be a consideration in the development of a butterfly valve for use in a liquefied natural gas (LNG) vessel. A flexible solid metal seal offers sufficient tightness of the butterfly valve and meets the specifications for cryogenic temperature. In the present study, characteristics for a cryogenic butterfly valve, such as the flow coefficient and the pressure loss coefficient, were estimated by numerical fluid analysis carried out to simulate 3-D flow and to study performance as it was affected by the opening angles of the valve disc. A design criterion to ensure the seat tightness of the butterfly valve at the fully shut position was proposed, in which the contact pressure between the metal seal and the valve disc would be compared with the fluid pressure. Numerical structural analysis showed that the contact pressure can be calculated by simulation of the frictional contact behavior on the surface of the metal seal and the valve disc. As a result, an adequate flexibility of the metal seal and the valve disc was required in order to accomplish a contact pressure that would be high enough to satisfy the seat tightness requirement. Under cryogenic temperature, thermal shrinkage caused the metal seal to adhere closely to the valve disc periphery at both sides and raised the contact pressure to a relatively high value, though there was no contact across a small area at the center position, which is susceptible to leakage. An additional displacement of the metal seal and the valve disc appeared at an operating fluid pressure of 6.9 bar and produced sufficient contact pressure at the no-contact area. This was verified by experimental leakage tests performed at room and cryogenic temperatures.
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Investigation of the mechanical behavior of a flexible solid metal seal for a cryogenic butterfly valve
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10.1007/s12206-011-0534-5
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2011-09-01
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The influence of cryogenic treatment on the wear resistance of En 19 steel was studied. Furthermore, a comparative analysis on the effect of Deep Cryogenic Treatment (DCT, —196 ’C ×24 h), Shallow Cryogenic Treatment (SCT, —80 °C×5 h) and Conventional Heat Treatment (CHT) was done through dry sliding wear testing. The microstructures of CHT, SCT and DCT samples were also examined through scanning electron microscopy. The results indicated that the wear resistance of shallow and deep cryogenically treated samples is higher when compared to that of conventionally treated samples. X-ray diffraction pattern revealed that the transformation of retained austenite into martensite is responsible for the wear resistance improvement.
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Influence of Shallow and Deep Cryogenic Treatment on Tribological Behavior of En 19 Steel
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10.1016/S1006-706X(12)60034-X
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2011-08-01
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Background Since the advent of the human genome, the era of personalized genomic medicine is indisputably in progress. Methods In an effort to contribute to the evolving knowledge of genomic medicine, we have aimed directly at building a bioresource bank for hepatocellular carcinoma. This tumor bank is based on the rigorous guidelines set forth by the National Cancer Institute, and it offers analytes to help elucidate the mechanisms of progression from cirrhosis to malignancy, risk factors for recurrence, and applicability of current treatment options to a diverse group of people. Conclusions Surgeons have a privileged position between patients (and their cancer) and the benches of basic science. Thus, we offer a primer based on our own experiences, from which surgeons may take elements to build their own bioresource bank for use in collaboration with others. We highlight some practicalities and pitfalls that could be overlooked, as well as a discussion of possible solutions.
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A Primer on a Hepatocellular Carcinoma Bioresource Bank Using the Cancer Genome Atlas Guidelines: Practical Issues and Pitfalls
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10.1007/s00268-010-0953-y
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2011-07-01
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In the past few years, polymer-based adsorbents have been emerging as highly effective alternatives to activated carbons for pollutants removal and recovery from industrial effluents. In this article, novel thermosensitive poly( N -isopropylacrylamide) (PNIPAAm) cryogels adsorbents were directly prepared with N -isopropylacrylamide (NIPAAm) as a thermosensitive monomer and PEG-20,000 as a porogen at −12 °C by means of an in situ free-radical redox cryopolymerization. Subsequently, PNIPAAm cryogels were further employed to adsorb and desorb melamine through temperature swing adsorption (TSA) between 25 and 50 °C. The adsorption isotherms were correlated to Langmuir and Freundlich isotherm models. Moreover, the result indicated that the developed PNIPAAm cryogels adsorbents could be utilized effectively to concentrate melamine from aqueous solutions and spiked liquid milk. The cycle of the adsorption and desorption could be repeated without much loss of the melamine adsorbing ability.
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Temperature swing adsorption of melamine on thermosensitive poly(N-isopropylacrylamide) cryogels
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10.1007/s10853-011-5392-0
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2011-07-01
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A hybrid ion mobility-mass spectrometer (IM-MS) incorporating a variable-temperature (80–400 K) drift tube is presented. The instrument utilizes an electron ionization (EI) source for fundamental small molecule studies. Ions are transferred to the IM-MS analyzer stages through a quadrupole, which can operate in either broad transmission or mass-selective mode. Ion beam modulation for the ion mobility experiment is accomplished by an electronic shutter gate. The variable-temperature ion mobility spectrometer consists of a 30.2 cm uniform field drift tube enclosed within a thermal envelope. Subambient temperatures down to 80 K are achievable through cryogenic cooling with liquid nitrogen, while elevated temperatures can be accessed through resistive heating of the envelope. Mobility separated ions are mass analyzed by an orthogonal time-of-flight (TOF) mass spectrometer. This report describes the technological considerations for operating the instrument at variable temperature, and preliminary results are presented for IM-MS analysis of several small mass ions. Specifically, mobility separations of benzene fragment ions generated by EI are used to illustrate significantly improved (greater than 50%) ion mobility resolution at low temperatures resulting from decreased diffusional broadening. Preliminary results on the separation of long-lived electronic states of Ti^+ formed by EI of TiCl_4 and hydration reactions of Ti^+ with residual water are presented.
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A Mass-Selective Variable-Temperature Drift Tube Ion Mobility-Mass Spectrometer for Temperature Dependent Ion Mobility Studies
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10.1007/s13361-011-0148-2
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2011-06-01
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We report on experimental investigations of acoustic emission by quartz tuning forks resonating at frequencies 32 kHz, 38 kHz, 77 kHz and 100 kHz immersed in cold gaseous ^4He and its normal and superfluid liquid phases. Frequency dependence of the observed low-drive-linewidth at 350 mK together with the temperature and pressure dependences (1.3 K < T < 4.2 K, 0 < p < 25 bar) of the observed damping of the high frequency (77 and 100 kHz) resonators measured in normal liquid ^4He and its superfluid phase provide strong and direct evidence of the importance of sound emission by these tuning forks. Three analytical models of acoustic emission by vibrating tuning forks are developed and compared with the experimental results. We also discuss the importance of sound emission for experiments with the commonly used 32 kHz tuning forks as well as other oscillating structures—spheres, wires, grids and various micromachined sensors. We compare the relative importance of dissipative losses due to laminar viscous/ballistic drag and acoustic emission in liquid and superfluid ^4He.
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Acoustic Emission by Quartz Tuning Forks and Other Oscillating Structures in Cryogenic ^4He Fluids
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10.1007/s10909-011-0353-1
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2011-06-01
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Objectives The objective of this work was to determine the dynamics of maximal anaerobic power (MAP) of the lower limbs, following a single whole body cryostimulation treatment (WBC), in relation to the temperature of thigh muscles. Materials and Methods The subjects included 15 men and 15 women with an average age (±SD) of 21.6±1.2 years. To evaluate the level of anaerobic power, the Wingate test was applied. The subjects were submitted to 6 WBC treatments at −130°C once a day. After each session they performed a single Wingate test in the 15, 30, 45, 60, 75 and 90th min after leaving the cryogenic chamber. The order of the test was randomized. All Wingate tests were preceded by an evaluation of thigh surface temperature with the use of a thermovisual camera. Results The average thigh surface temperature (T_av) in both men and women dropped significantly after the whole body cryostimulation treatment, and next increased gradually. In women T_av remained decreased for 75 min, whereas in men it did not return to the basal level until 90th min. A statistically insignificant decrease in MAP was observed in women after WBC. On the contrary, a non-significant increase in MAP was observed in men. The course of changes in MAP following the treatment was similar in both sexes to the changes in thigh surface temperature, with the exception of the period between 15th and 30th min. The shorter time to obtain MAP was observed in women till 90th min and in men till 45 min after WBC compared to the initial level. Conclusions A single whole body cryostimulation may have a minor influence on short-term physical performance of supramaximal intensity, but it leads to improvement of velocity during the start as evidenced by shorter time required to obtain MAP.
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The influence of single whole body cryostimulation treatment on the dynamics and the level of maximal anaerobic power
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10.2478/s13382-011-0017-z
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2011-05-01
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A Bi-15 at.%Sb alloy, homogenized by equal channel angular extrusion (ECAE) at T = 523 K, has been treated just above its solidus temperature, causing segregation of a secondary Bi-rich phase at the grain boundaries. This process results in an in situ composite. The thermoelectric properties of the composite have been measured in the range of 5 K < T < 300 K. The results are compared with those of the homogeneous alloy. The presence of a Bi-rich phase improves the Seebeck coefficient at T < 50 K, and enhances the electrical conductivity by a factor of 1.4 at T = 300 K up to a factor of 3.4 at T = 50 K; unfortunately, the thermal conductivity also increases by about 50% in the same temperature range. As a result, the figure of merit, Z , is slightly suppressed above T = 110 K, but increases at lower temperatures, reaching a peak value of 4.2 × 10^−3 K^−1 at T = 90 K. The power factor considerably increases over the whole temperature range, rendering this material suitable as the n -type leg of a cryogenic thermoelectric generator for cold energy recovery in a liquefied natural gas plant.
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Thermoelectric Properties of In Situ Formed Bi_0.85Sb_0.15/Bi-Rich Particles Composite
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10.1007/s11664-010-1450-7
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2011-05-01
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The DAΦNE electron–positron collider at the Laboratori Nazionali di Frascati of INFN has made available a unique quality low-energy negative kaons “beam”. The SIDDHARTA experiment used this beam to perform unprecedented precision measurements on kaonic atoms, while the AMADEUS experiment plans to perform in the coming years precision measurements on kaon–nuclei interactions at low-energies, in particular to study the kaonic nuclei. The two experiments are briefly presented in this paper.
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Low-Energy Kaon–Nucleon/Nuclei Interaction Studies at DAΦNE (SIDDHARTA and AMADEUS Experiments)
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10.1007/s00601-010-0184-7
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2011-05-01
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Mechanical properties of quenching, intercritical quenching and tempering (QLT) treated steel containing Ni of 9% were evaluated from specimens subject to various tempering temperatures. The detailed microstructures of steel containing Ni of 9% at different tempering temperatures were observed by optical microscope (OM) and trans- mission electron microscope (TEM). The volume fraction of austenite was estimated by XRD. The results show that high strength and cryogenic toughness of steel containing Ni of 9% are obtained when the tempering temperature are between 540 and 580 °C. The microstrueture keeps the dual phase lamellar structure after the intercritical quenching and there is cementite created in the Ni-rich constituents when tempering temperature is 540 °C. When tempering temperatures are between 560 and 580 °C, the reversed austenites (γ′) grow up and the dual phase lamellar structure is not clear. The γ′ becomes instable at 600 °C. When tempered at temperature ranging from 500 to 520 °C, the increase of dislocation density in the lamellar matrix makes both tensile strength and yield strength decrease. When tempered at 540 °C and higher temperature, the yield-strength decreases continuously because the C and alloying elements in the matrix are absorbed by the cementite and the γ′, so the yield ratio is decreased by the γ′. There are two toughness mechanisms at different tempering temperatures. One is that the precipitation of cementite absorbs the carbon in the steel which plays a major role in improving cryogenic toughness at lower temperature. Another is that the γ′ and the purified matrix become major role at higher tempering temperature. When the tempering temperature is 600 °C, the stability of γ′ is decreased quickly, even the transformation takes place at room temperature, which results in a sharp decrease of Charpy-V impact energy at 77 K. The tempering temperature range is enlarged by the special distribution of cementite and the lamellar structure.
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Effect of Tempering Temperature on Microstrueture and Mechanical Properties of Steel Containing Ni of 9 %
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10.1016/S1006-706X(11)60064-2
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2011-05-01
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Force, deformation, velocity, energy, and other criteria of limiting states at low-temperature serrated yield of metals are examined. The feasibility of their use for setting norms and standards of strength and mechanical tests is demonstrated.
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Strain instability in metals at cryogenic temperatures and potentials of practical application
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10.1007/s11223-011-9294-9
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2011-05-01
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The method of automatic analysis of patterns of electron back-scatter diffraction (EBSD) is used to study the efficiency of different variants of cryogenic deformation for obtaining a nanocrystalline (NC) structure in technically pure copper. Deformation at the temperature of liquid nitrogen has caused considerable refinement of grains, but the NC range has not been attained.
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Refining of grains in copper by means of cryogenic deformation
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10.1007/s11041-011-9348-4
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2011-05-01
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N ovel single-photon detectors, called Charge-sensitive Infrared Phototransistor (CSIP), have been developed in the long wavelength infrared (LWIR) range. The devices are fabricated in GaAs/AlGaAs double-quantum-well (DQW) structure, and do not require ultralow temperatures ( T < 1 K) for operation. Figures of merit are determined in a T -range of 4.2 K∼30 K by using a homemade all-cryogenic spectrometer. We found that the photo-signal persists up to around 30 K. Excellent specific detectivity D ^* = 9.6 × 10^14 cm Hz^1/2/W and noise equivalent power NEP = 8.3 × 10^−19 W/Hz^1/2 are derived up to T = 23 K. The dynamic range of detection exceeds 10^6, roughly ranging from attowatt to picowatt levels. These values are by a few orders of magnitude higher than that of the state-of-the-art values of other detectors. Simple planar structure of CSIPs is feasible for array fabrication and will make it possible to monolithically integrate with reading circuit. CSIPs are, therefore, not only extremely sensitive but also suitable for practical use in wide ranging applications.
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Temperature Dependence of Novel Single-Photon Detectors in the Long-Wavelength Infrared Range
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10.1007/s10762-010-9659-3
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2011-05-01
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The organization of the Electromagnetic Research Center in Troitsk, based on a 2-GeV electron accelerator with a continuous high-intensity electron beam developed on the basis of cryogenic HF structures, is justified. Production of energy-labeled short-lived mesons is discussed. The main line of research is the study of the effect of the nuclear medium on hadron characteristics.
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Prospects of the study of the nuclear and electromagnetic interactions of hadrons in the 2-GeV electron accelerator beam
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10.3103/S1068335611050046
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2011-04-01
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Single-wave length operation of a c-cut Tm (5%), Ho (0.3%):YAP microchip laser pumped by a fiber-coup led diode-laser was reported. Under cryogenic temperature, the output power of 188 mW was obtained under the incident power of 2230 mW, corresponding to the slope efficiency was 12.2%. As much as 168 mW output and slope efficiency of 5.7% was obtained under the pump power of 3400 mW at 291 K. In addition, a maximum single-wave length output power of 60 mW at wavelength of 2130.2 nm and 14 mW at wavelength of 2102.4 nm is demonstrated under 77 and 291 K, respectively.
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Diode pumped operation of tm, Ho:YAP microchip laser
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10.1134/S1054660X11070358
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2011-04-01
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Macroporous viscoelastic poly(vinyl alcohol) (PVA) cryogels were prepared from aqueous PVA solutions containing additives (0–1.2 mol/l) of alkali metal chlorides (LiCl, NaCl, KCl, CsCl) by cryogenic treatment (freezing at −20°C for 12 h and subsequent thawing at a rate of 0.03°C/min). Shear moduli and fusion temperatures of corresponding samples were determined and the structure of thin sections was studied by optical microscopy with subsequent processing and analysis of images obtained. It was shown that the rigidity, heat endurance, and mean pore sizes of formed cryogels monotonically decrease with increasing content of chaotropic lithium chloride. In the case of other three salts, the dependences of rheological characteristics of cryogels on the concentration of low-molecular-weight electrolyte were extreme due to the competition between factors that promote and prevent PVA cryotropic gelation. At the same time, fusion temperatures of gel samples increased steadily with increasing content of these salts. Microscopic studies revealed substantial (by factor of two to three) decrease in macropore sizes even at low content of salt compared to mean cross sections of pores in cryogel containing no additive; morphometric analysis of obtained images makes it possible to reveal the linear correlations between the rheological characteristics of cryogels formed in the presence of LiCl and the sizes of their macropores.
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Study of cryostructuring of polymer systems: 31. Effect of additives of alkali metal chlorides on physicochemical properties and morphology of poly(vinyl alcohol) cryogels
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10.1134/S1061933X11020086
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2011-04-01
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The cryogenic treatment of tool steels has transformed over centuries from black art to science, but the metallurgical principles responsible for increase in wear resistance, tensile strength, toughness, and stability are still disputed. Metallurgists comprehend how tool steels respond to cryogenic treatment, but they also understand that for many years, the cryogenic treatment of tool steels had the reputation of being a quick fix for poor heat treatment practice. During the cryogenic treatment of tool steels, the process modifies the carbon present in the tool steels. However, cryogenic treatment has not been widely adopted by the cutting tools industry due to lack of understanding of the fundamental metallurgical mechanisms and due to the wide variation in reported research findings. In the present paper, an attempt has been made to review the literature on metallurgical changes that occurred during the cryogenic treatment of tool steels to benefit the cutting tools industry. The prominent reasons found to be responsible for improving the mechanical properties of tool steels are transformation of retained austenite to martensite and precipitation of fine carbides.
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Metallurgical principles of cryogenically treated tool steels—a review on the current state of science
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10.1007/s00170-010-2935-5
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2011-04-01
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The developed dislocation structure that forms during cryorolling of a D16 alloy is found to be retained after short-term heating to 200°C. At higher temperatures, it undergoes recovery and recrystallization with the formation and growth of nanograins. Rolling intensify the decomposition of a preliminarily supersaturated aluminum solid solution, proving the alloy high-strength after artificial aging at a lower temperature and a shorter time as compared to a conventional T6 temper.
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Microstructure and properties of an aluminum D16 alloy subjected to cryogenic rolling
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10.1134/S0036029511040136
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2011-01-01
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Improved functional performance and longer service life of biomedical products offer great sustainability benefits. Surface integrity, which can be modified by severe plastic deformation (SPD) processes, affects the functional performance of materials. Two SPD processes – burnishing and machining – were studied under cryogenic conditions. Cryogenic burnishing of a Co-Cr-Mo biomedical alloy using a novel burnishing tool led to significant grain refinement and 80% greater surface microhardness relative to the bulk. Cryogenic burnishing of AZ31 Mg alloy led to a more than 2 mm thick SPD surface layer with remarkably refined microstructure (grains <300 nm), where hardness was increased 95%. The SPD layer formed on AZ31 Mg alloy after cryogenic machining was about 60% harder than the bulk material. Furthermore, this layer enhanced corrosion resistance during incubation in simulated body fluid. The present results demonstrate significant surface and subsurface property improvement due to cryogenic processes of both alloys, thus providing improved sustainability.
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Cryogenic Processing of Biomaterials for Improved Surface Integrity and Product Sustainability
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10.1007/978-3-642-20183-7_26
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2011-01-01
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This document is part of Part 2 'Principles and Methods' of Subvolume B 'Detectors for Particles and Radiation' of Volume 21 'Elementary Particles' of Landolt-Börnstein - Group I 'Elementary Particles, Nuclei and Atoms'. It contains the Section '6.4 Cryogenic Detectors' of Chapter '6 Detectors for Special Applications' with the content: 6.4 Cryogenic Detectors 6.4.1 Introduction 6.4.2 General features of cryogenic calorimeters 6.4.3 Phonon Sensors 6.4.3.1 Semiconducting Thermistors 6.4.3.2 Super-conducting Transition Edge Sensors (TES) 6.4.3.3 Magnetic Sensors 6.4.4 Quasiparticle Detection 6.4.4.1 Superconducting Tunnel Junctions (STJ) 6.4.4.2 Microwave Kinetic Inductance Detector 6.4.4.3 Super-heated Super-conducting Granules (SSG) 6.4.5 Physics with Cryogenic Detectors 6.4.5.1 Direct Dark Matter Detection 6.4.5.2 Neutrino mass searches 6.4.5.2.1 Neutrinoless double beta decay 6.4.5.2.2 Direct neutrino mass measurements 6.4.5.3 Astrophysics 6.4.5.3.1 X-Ray Astrophysics 6.4.5.3.2 Optical/UV and CMB Astrophysics 6.4.6 Applications 6.4.7 Summary
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Cryogenic Detectors
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10.1007/978-3-642-14142-3_5
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2011-01-01
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The storage of the different microorganisms over long periods is necessary to ensure reproducible results and continuity in research and in biomedical processes and also for commercial purposes. Effective storage means that a microorganism is maintained in a viable state free of contamination or genetic drift and must be easily restored without genotypic or phenotypic alterations to its original characteristics and properties. To this end, different techniques have been described and advances in cryopreservation technology have led to methods that allow low-temperature maintenance of a variety of cell types, minimizing the risks of genetic change and are now recommended for long-term storage of most microorganisms. This chapter summarizes the most important steps and components in the process of low- and ultra-low temperatures freezing of bacteria, parasites, yeasts and fungi, viruses, and recombinant microorganisms.
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Collection and Preservation of Frozen Microorganisms
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10.1007/978-1-59745-423-0_18
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2011-01-01
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The realization of the triple points of the cryogenic gases hydrogen, neon, oxygen, and argon as temperature fixed points at the highest level of accuracy requires consideration of the special properties of these fixed-point substances, as done in a general measurement protocol published elsewhere. The protocol is applied to the apparatus and methodology used for an international star intercomparison of sealed fixed-point cells. A generalized thermal model is developed to include the coexistence of different solid–liquid interfaces and various thermal resistances. This results in further components in the detailed uncertainty budget for the correction of the measuring power of the thermometer and for the extrapolation to the liquidus point. As a basis for an optimum fixed-point realization, especially an explanation is given why extremely long time periods may be necessary for the thermal recovery after pulses of the intermittent heating used for the calorimetric method.
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Improved Thermal Model for the Realization of the Triple Points of Cryogenic Gases as Temperature Fixed Points
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10.1007/s10765-011-0935-9
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2011-01-01
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The main stages of the development of frontal polymerization are presented. The processes taking place at cryogenic temperatures, under high (up to 5 kbar) pressures and usual conditions, when the polymerization is performed in glass ampoules without excessive pressure, are discussed. Depending on the Semenov parameter, the conditions of polymerization in low-temperature quasi-isothermal and high-temperature adiabatic or frontal thermal modes are considered. Theoretical and experimental data for the dependence of the front velocity on the various parameters. The influence of the nature of initiator, monomer, and dispersed inorganic on the reaction order with respect to the initiator is analyzed. Monomers polymerizing in the reaction front propagation are classified regarding their polymerization rates and boiling temperatures. The articles of various authors devoted to the synthesis of polymer materials and polymer-based composites difficult to obtain under conventional conditions are considered. The reactors of frontal polymerization in turbulent and laminar flows, widely applied in practice, are studied. Certain conclusions are made on the further development of frontal polymerization processes on the basis of data available in the literature.
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Advances and problems of frontal polymerization processes
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10.1134/S207997801101002X
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2011-01-01
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In this paper we present an investigation into several strain sensing technologies that are being considered to monitor mechanical deformation within the steel reinforcement shells used in high field pulsed magnets. Such systems generally operate at cryogenic temperatures to mitigate heating issues that are inherent in the coils of nondestructive, high field pulsed magnets. The objective of this preliminary study is to characterize the performance of various strain sensing technologies at liquid nitrogen temperatures (-196oC). Four sensor types are considered in this investigation: fiber Bragg gratings (FBG), resistive foil strain gauges (RFSG), piezoelectric polymers (PVDF), and piezoceramics (PZT). Three operational conditions are considered for each sensor: bond integrity, sensitivity as a function of temperature, and thermal cycling effects. Several experiments were conducted as part of this study, investigating adhesion with various substrate materials (stainless steel, aluminum, and carbon fiber), sensitivity to static (FBG and RFSG) and dynamic (RFSG, PVDF and PZT) load conditions, and sensor diagnostics using PZT sensors. This work has been conducted in collaboration with the National High Magnetic Field Laboratory (NHMFL), and the results of this study will be used to identify the set of sensing technologies that would be best suited for integration within high field pulsed magnets at the NHMFL facility.
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Strain Sensors for High Field Pulse Magnets
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10.1007/978-1-4419-9834-7_138
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2011-01-01
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The shock compression experiment of liquid helium is an available way to gain properties of specimen at high temperatures and pressures. Based on Fluent, a thermal insulation analysis and design of a liquid helium temperature target in the environment condition of 100 Pa for shock compression experiment is performed. Then, a cryogenic target with a 10 K helium vapor shield and a separated vacuum interval is particularly developed. A lowest temperature of 3.63 K and a stable temperature of 3.70 K in the specimen cavity with an accuracy of 0.1 K are obtained by means of continuous flow and vacuum cooling. Both time-consuming and temperature stability are well-suited to the requirements of the shock compression experiment. The results show that the calculated and experimental data well-matched each other. The simulation method may be effective and feasible for the optimal design of the cryogenic target.
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A liquid helium temperature target with a 10 K vapor shield for shock compression experiment in the environment condition of 100 Pa
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10.1007/s11434-010-3136-1
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2011-01-01
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An overview of the parameters of a large number of sealed triple-point cells for the cryogenic gases hydrogen, oxygen, neon, and argon is given that have been determined within the framework of an international star intercomparison to optimize the measurement of melting curves as well as to establish complete and reliable uncertainty budgets for the realization of temperature fixed points. Special emphasis is given to the question, whether the parameters are primarily influenced by the cell design or the properties of the fixed-point samples. For explaining surprisingly large periods of the thermal recovery after the heat pulses of the intermittent heating through the melting range, a simple model is developed based on a newly defined heat-capacity equivalent, which considers the heat of fusion and a melting-temperature inhomogeneity. The analysis of the recovery using a graded set of exponential functions containing different time constants is also explained in detail.
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Investigation of the Parameters of Sealed Triple-Point Cells for Cryogenic Gases
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10.1007/s10765-010-0883-9
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2010-12-01
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By analyzing experimental data, the lowest modes that are responsible for pyroelectricity in DKDP single crystals (87.3 and 201.6 cm^−1) and in PZT-40 ferroelectric ceramics (20.7, 54.75, and 171.3 cm^−1) are determined. A set of physical mechanisms that occur in real polar dielectrics that are piroelectrically active in the temperature range 0–30 K is discussed; and methods of their identification, separation, and determination of quantitative characteristics for each component of spontaneous polarization are shown.
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On the pyroelectricity of DKDP single crystals and PZT-40 ceramics at 1.5–30 K
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10.3103/S0027134910060147
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2010-10-01
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Capillary driven surface oscillations of liquid argon (T_sat = 87.3 K at 1,013 hPa) have been investigated in a partly filled right circular cylinder under non-isothermal boundary conditions. The oscillations take place during the reorientation from the normal gravity surface position towards a new position upon step reduction of gravity. The situation is similar to the end of thrust in a rocket tank when the cold propellant moves along the warmer tank wall driven by capillary forces. The aim was to investigate the influence of the temperature difference between the slightly subcooled cryogenic liquid and the superheated cylinder wall on the oscillations and their characteristics in a single-component, two-phase system. Axial wall temperature gradients of averaged 0.15 K/mm − 1.93 K/mm above the normal gravity surface position were implemented. A general dependence of the reorientation behavior on the gradient value was observed, concerning the apparent contact line behavior, the frequency and damping of the oscillations of the free surface center point, and the apparent contact angle. The behavior of the ullage pressure was found to follow the behavior of the contact line.
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Drop Tower Experiments on Non-isothermal Reorientation of Cryogenic Liquids
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10.1007/s12217-010-9237-2
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2010-10-01
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A new method was used to analyze the factors affecting the precipitation of reversed austenite during tempering. The samples were kept at various tempering temperatures for 10 min and their length changes were recorded. Then, the precipitation of reversed austenite which led to the length reduction was shown by thermal expansion curves. The results show that the effects of process parameters on the precipitation of reversed austenite can be determined more accurately by this method than by X-ray diffraction. When the quenching and tempering process is adopted, both the lower quenching temperature and higher tempering temperature can promote the precipitation of reversed austenite during tempering; and when the quenching, lamellarizing, and tempering process is used, intercritical quenching is considered beneficial to the precipitation of reversed austenite in the subsequent tempering because of Ni segregation during holding at the intercritical temperature.
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Precipitation and stability of reversed austenite in 9Ni steel
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10.1007/s12613-010-0361-1
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2010-10-01
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The methods developed at the Pisarenko Institute of Problems of Strength of the National Academy of Sciences of Ukraine for determining the allowable stresses for structural elements operating at cryogenic temperatures are considered. The methods make it possible to take into account the effect of the low-temperature hardening and the softening electromagnetic action on the value of allowable stresses.
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On the selection of allowable stresses in the strength analysis of structures for cryogenic applications
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10.1007/s11223-010-9244-y
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2010-10-01
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The influence of rolling at a liquid-nitrogen temperature on the microstructure of commercially pure copper has been investigated by the methods of transmission electron microscopy (TEM) and automated analysis of electron backscatter diffraction (EBSD) patterns. It has been established that the process of the structure formation was sufficiently complex and included a geometric effect of deformation, recrystallization, twinning, and fragmentation. It is shown that upon deformation to 50% the structure evolution was controlled by the Taylor-Polanyi principle. However, it was established that at larger reductions the formation of grain structure was determined by the competition between the geometric effect of deformation and recrystallization. The contribution of twinning and fragmentation to the structure formation was insignificant in the entire interval of deformations investigated. The recrystallization, apparently, was caused by the warming up of the sample to room temperature after low-temperature rolling.
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Effect of low-temperature rolling on the structure of copper
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10.1134/S0031918X10100029
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2010-09-01
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Following the practical impossibility to obtain new precision Rh–0.5 at%Fe thermometers over the past years, re-starting the commercial production of such thermometers in Yunnan (China) was explored by INRIM in cooperation with NIM and with the help of INTiBS for prototype characterization. The present aim is to obtain a stability of the new thermometers at the level of ±1 mK at 4.2 K. In 2008, a new batch of eight prototypes was produced. This paper reports the results of the measurements on the full characteristics of these prototypes in the range from 2.5 K to 25 K, which confirms a similarity to the typical characteristics of previous commercial RhFe thermometers, and of the effect of thermal cycling, showing for six out of eight thermometers, a stability better than ±1 mK (limited by the measurement expanded uncertainty of ≈0.8 mK) at 4.2 K and up to ≈10 K, and better than ±0.01 % T in the range from 2.5 K to 25 K. These results indicate that production problems on these commercially available thermometers are basically resolved at the aimed level of stability. Further studies are foreseen to improve production uniformity and to check if stability may actually be better by using a test apparatus of sub-millikevin uncertainty.
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Development of Precision Rh–0.5 at%Fe Thermometers of Chinese Production: Further Tests
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10.1007/s10765-010-0829-2
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2010-09-01
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The effect of magnetic fields on martensitic transformation in austenitic steels and alloys at low temperatures is studied. Under specific conditions magnetic fields can initiate the appearance of martensite in austenitic alloys or increase its content in steels with austenitic-martensitic structure. This causes changes in the physical and mechanical properties of the material and this should be allowed for when the metal is used in devices operating at cryogenic temperatures in the presence of strong magnetic fields.
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Special features of the effect of magnetic fields on the γ → α transformation in steels and alloys at low temperatures
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10.1007/s11041-010-9245-2
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2010-09-01
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Waste polymer materials were analyzed by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The concentrations of 35 elements were determined by using different types of external standards, namely glass and polyethylene (PE) based. Prior to the LA-ICP-MS analysis of determined elements, Na and/or Zn were used as internal standards. The investigations concentrated mainly on the detection of Cr, As, Cd, Sn, Sb, Hg, and Pb. Using PE-based calibration standards, the measured concentrations in the waste polymers were within 49% of the wet chemical data. The determined deviation was up to 102% when using the glass standards. Trace concentration of As and Hg (and also of S) could be determined with a concentration below 1 mg/kg. However, Hg provided very low intensity with a high relative standard deviation (RSD) and was therefore not further evaluated. Cryomilling of polymers was applied to reduce the particle size of the material and improved the precision and accuracy of LA-ICP-MS analysis. On average, the LA-ICP-MS results showed a deviation from the wet chemical reference analysis of 38% and an RSD of 56% for pressed polymer powder samples prepared by cryomilling. In general, waste pellets without sample preparation (i.e., use of pellets as delivered) are too heterogeneous, not suitable for micro-beam techniques, and showed a strong matrix dependence. With homogeneous pellets that appear similar to each other agreement in the determined concentrations was found for some elements.
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LA-ICP-MS analysis of waste polymer materials
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10.1007/s00216-010-3963-6
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2010-09-01
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Cyanide-free Au plating baths, containing KAuCl_4, triammonium citrate, and sodium sulfite, have been developed by the authors. The stability of these solutions depends on the order of mixing of the additives. The aim of this study was to employ turbidity measurements and cryogenic x-ray photoelectron spectroscopy (XPS) to identify the role of the additives and the complexes responsible for solution stability or degradation. Electron microscopy was used to characterize any precipitation products generated in the solutions. It was shown that the long-term stability of the solutions is due to the role of citrate and sulfite as complexing agents.
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A Cryo-XPS Study of Triammonium Citrate-KAuCl_4-Na_2SO_3 Electroplating Solutions for Pb-Free Solder Packaging
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10.1007/s11664-010-1273-6
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2010-09-01
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Nano-powder of a negative temperature coefficient (NTC) ceramic with a spinel structure of Mn–Ni–Cu–Co–La–O composition was prepared by the Pechini method. A type of NTC thermistor sensor (3.0 mm diameter × 1.5 mm high) was designed by the in situ lead wire attachment method (ISAM) and made using the synthesized powder. NTC thermistors were packed in the glass-sealed package. Six independent NTC thermistors were calibrated using a cryostat, a standard platinum resistance thermometer, and a Fluke 1590 super thermometer meter over the temperature range from 18 K to 120 K. The data were interpolated to obtain calibration tables at 2 K intervals from 18 K to 30 K, and at 5 K intervals from 30 K to 120 K. These tables were fitted with the equation: 1/ T = A _0 + A _1 ln( R / R _ref) + A _2 ln( R / R _ref)^2 + A _3 ln( R / R _ref)^3 + A _4 ln( R / R _ref)^4. Aging, thermometric characteristics, fitting of calibrated data, stability of NTC thermistors, and the effect of a magnetic field on NTC thermistors were investigated.
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Construction and Characterization of NTC Thermistors at Low Temperature
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10.1007/s10765-010-0790-0
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2010-09-01
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Following the start of exploration of the problem of the effect of neon isotopes on the triple-point temperature in 2005, further progress was achieved in 2006–2008, and published in 2008. This paper summarizes the advances to date in our understanding as obtained from further work done in 2008–2009 on five basic aspects of the problem: new isotopic assays; new thermal measurements on neon of “natural” composition; the feasibility of obtaining a value of the slope d T _tp/d x (^22Ne) with an accuracy sufficient for the purpose; the possible occurrence of isotopic fractionation during the process of sealing the samples in the cells; and new thermal measurements on the pure isotopes ^20Ne and ^22Ne. The recently collected information is sufficient to state that it will eventually be possible to fulfill within 2010 the goal of recommending to the CCT solutions for the correction, with an accuracy fitting the purpose, of the neon isotopic effect on T _tp, to be included in a future revision of the Technical Annexe to the “mise en pratique” of the kelvin.
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Further Progress Toward the Determination of T
_tp−x(^22Ne)
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10.1007/s10765-010-0817-6
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2010-09-01
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We calculate the concentration of plasma and gas-temperature components in a contracted filament of a glow capillary discharge ( R = 0.75 mm) in xenon for pressures of P = 100 and 400 Torr and currents of I = 6–15 mA for cases of with and without cryogenic cooling of the discharge. We find that the gas temperature in the channel of the glow discharge has a value of 1000–2000 K, the concentration of xenon excimers attains a maximum at the boundary of the filament with a value of 10^10–10^11 cm^−3, and the efficiency of electric energy transformation into excimer radiation energy has a value of 0.1–5%.
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Calculation of the parameters of excimer light sources on the basis of a positive column glow discharge
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10.1134/S0030400X10090237
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2010-09-01
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Using a new brand of commercially available carbon resistor we built a cryogenic thermometer with an extremely good thermal contact to its thermal environment. Because of its superior thermal contact the thermometer is insensitive to low levels of spurious radio frequency heating. We calibrated our thermometer down to 5 mK using a quartz tuning fork He-3 viscometer and measured its thermal resistance and thermal response time.
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A New Type of Carbon Resistance Thermometer with Excellent Thermal Contact at Millikelvin Temperatures
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10.1007/s10909-010-0192-5
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2010-09-01
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The defects and properties of a precipitation hardening Al–Cu alloy 2017 were studied after rolling at room temperature (RT) and cryogenic (liquid N_2) temperature (CT). It is found that CT rolling produced practically the same hardness as RT rolling for a wide range of rolling strains. However, electrical resistivity measurement revealed a clear difference indicating different defect structures in the CT- and RT-rolled samples. This difference led to higher hardness, after subsequent ageing, for samples processed by CT rolling. It is deduced that precipitation occurred during RT rolling, which compensated for the effect of lower dislocation density (evaluated from X-ray diffraction) in RT-rolled sample, and consequently resulted in similar hardness in both RT- and CT-rolled samples. It is noted that after ageing, CT-rolled sample has higher strength (~35%) than the standard T4 treatment.
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Effect of rolling temperature on the evolution of defects and properties of an Al–Cu alloy
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10.1007/s10853-010-4484-6
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2010-09-01
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The effects of deformation temperatures and post-deformation annealing on mechanical properties, in conjunction with microstructural evolution in the 5052 Al alloy, were investigated. The combination of cryogenic-rolling with warm-rolling effectively increased tensile strength and yield strength without the decrease of ductility through the formation of ultra-fine grains with dynamic recovery in the 5052 Al alloy. And static annealing, as a post-heat treatment, enhanced the ductility. Therefore, ultra-fine grained 5052 Al alloy with high strength and a moderate level of ductility could be made by the combination of cryogenic-rolling with warm-rolling and the additional static annealing process.
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The improvement of strength and ductility in ultra-fine grained 5052 Al alloy by cryogenic- and warm-rolling
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10.1007/s10853-010-4573-6
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2010-08-01
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BEPCII cryogenic system consists of a cavity cooling loop and a magnet cooling loop. Although the magnet cooling loop has lower heat load than the cavity cooling loop, it needs much more helium mass flow since only sensible heat of the supercritical helium is used to cool the SCQ magnets. As a result, excess liquid helium exists in the return line of the magnet cooling loop and should be evaporated by electrical heater, leading to a waste of cooling power. This paper discusses several solutions for operating the system economically.
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Economical Running of BEPCII Cryogenic System
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10.1007/s10948-009-0640-0
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2010-08-01
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With the requirement of higher beam energy and luminosity, the cryogenic technologies are applied more and more widely in accelerator facilities. As a main research entity on cryogenics in China, Technical Institute of Physics and Chemistry (TIPC) makes significant contributions to the construction of cryogenic systems for several superconducting accelerators in China, i.e. the upgrade of the Beijing Electron-Positron Collider (BEPCII), the Shanghai Synchrotron Radiation Facility (SSRF) and the Peking University Free-Electron Laser Facility (PKU-FEL). In this paper the cryogenic systems for BEPCII, SSRF and PKU-FEL are introduced briefly, and our recent activities for these accelerators are described.
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Recent Activities of TIPC on Cryogenic Systems Used for Superconducting Accelerators in China
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10.1007/s10948-009-0641-z
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2010-08-01
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Semiclassical model, which takes into consideration the spatial dispersion effects in conductivity and permittivity, demonstrates the possible appearance of additional waves in conducting media, which are known to exist in transparent dielectrics near a narrow absorption band. The dispersion law of additional waves for modelling media (one-dimensional conductance) with parameters of Cu and Nb is obtained, which predicts the novel phenomenon—the possibility for additional microwave modes to propagate in metals with low enough attenuation at cryogenic temperatures.
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Additional microwave modes in systems with conductivity of metals and superconductors
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10.1134/S1063776110080236
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2010-08-01
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The mechanism of cryotropic gelation in moderately frozen solutions of chitosan crosslinked by glutaric aldehyde is studied. Chitosan cryogels with large pores are synthesized at a low content of crosslinking agent in the reaction mixture or under conditions that do not lead to gelation at temperatures above 0°C. The dependences of the yield of gel fractions, the degree of swelling of the polymer phase of cryogels, and the hydrodynamic characteristics of cryogels on the temperature of synthesis are shown to be extremal. This result may be explained by the competition between the cryoconcentration of reagents in the nonfrozen liquid microphase, which assists the development of a crosslinked polymer network, and such factors as an increase in the viscosity of the reaction mixture and a reduced reagent mobility, which prevent gelation. The morphology of chitosan cryogels is studied, and the character of the macroporous structure of the samples prepared at different temperatures is shown to exert a stronger effect on the hydrodynamic characteristics of a cryogel than the degree of swelling of crosslinked polymers in the walls of its macropores.
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Synthesis and characteristics of cryogels of chitosan crosslinked by glutaric aldehyde
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10.1134/S0965545X10080092
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2010-08-01
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The effect of different types of structures produced by quenching from the intercritical temperature range on the strength, plasticity, and impact toughness of the Fe-6.9Ni-0.1C alloy has been studied. Two structures—ferrite + globular cementite and lath martensite—have been used as the initial state. The rate of heating into the two-phase (α + γ) field has been selected such that four morphological types of twophase structures, namely, ferritic-martensitic (Widmanstäten or globular) and duplex (lamellar or lamellarglobular), could be formed in a single alloy as a result of partial α → γ and γ → α transformations. It has been found that the mechanical properties of the alloy depend on the type of the initial structure and on the rate and temperature of heating to the intercritical temperature range. It has been shown that the alloy with a Widmanstätten ferritic-martensitic structure has a more favorable combination of the strength and plasticity properties than the alloy with a globular structure. The alloy with a lamellar duplex structure offers a much higher level of the impact toughness, plasticity, and strength at low temperatures than the alloy with a Widmanstätten ferritic-martensitic structure.
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Structure formed in two-phase (α + γ) field and mechanical properties of a cryogenic alloy 10N7
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10.1134/S0031918X10080089
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2010-06-01
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Cavitation is often triggered when the fluid pressure is lower than the vapor pressure at a local thermodynamic state. The present article reviews recent progress made toward developing modeling and computational strategies for cavitation predictions under both isothermal and cryogenic conditions, with an emphasis on the attached cavity. The review considers alternative cavitation models along Reynolds-averaged Navier–Stokes and very lager eddy simulation turbulence approaches to ensure that the computational tools can handle flows of engineering interests. Observing the substantial uncertainties associated with both modeling and experimental information, surrogate modeling strategies are reviewed to assess the implications and relative importance of the various modeling and materials parameters. The exchange between static and dynamic pressures under the influence of the viscous effects can have a noticeable impact on the effective shape of a solid object, which can impact the cavitation structure. The thermal effect with respect to evaporation and condensation dynamics is examined to shed light on the fluid physics associated with cryogenic cavitation. The surrogate modeling techniques are highlighted in the context of modeling sensitivity assessment.
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Modeling of turbulent, isothermal and cryogenic cavitation under attached conditions
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10.1007/s10409-010-0342-7
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2010-06-01
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The effect of cryogenic treatment on the properties of Cr8-type cold work die steel was investigated. The results show that cryogenic treatment increases hardness by decreasing retained austenite, but the degree depends on the austenitizing temperature. When quenching at lower austenitizing temperature, the steel can obtain higher toughness by cryogenic treatment substituting conventional treatment process. Cryogenic time has little effect on cryogenic treatment. Conversely, cryogenic temperature has a great effect on cryogenic treatment and the effect of cryogenic treatment is more obvious with decreasing cryogenic temperature. In addition, deep cryogenic treatment improves the wear resistance by precipitating more homogeneous specific carbides.
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Effect of Cryogenic Treatment on Properties of Cr8-Type Cold Work Die Steel
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10.1016/S1006-706X(10)60112-4
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2010-06-01
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Cu samples were subjected to high-pressure torsion (HPT) with up to 6 turns at room temperature (RT) and liquid nitrogen temperature (LNT), respectively. The effects of temperature on grain refinement and microhardness variation were investigated. For the samples after HPT processing at RT, the grain size reduced from 43 μm to 265 nm, and the Vickers microhardness increased from HV52 to HV140. However, for the samples after HPT processing at LNT, the value of microhardness reached its maximum of HV150 near the center of the sample and it decreased to HV80 at the periphery region. Microstructure observations revealed that HPT straining at LNT induced lamellar structures with thickness less than 100 nm appearing near the central region of the sample, but further deformation induced an inhomogeneous distribution of grain sizes, with submicrometer-sized grains embedded inside micrometer-sized grains. The submicrometer-sized grains with high dislocation density indicated their nonequilibrium nature. On the contrary, the micrometer-sized grains were nearly free of dislocation, without obvious deformation trace remaining in them. These images demonstrated that the appearance of micrometer-sized grains is the result of abnormal grain growth of the deformed fine grains.
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Influence of processing temperature on microstructure and microhardness of copper subjected to high-pressure torsion
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10.1007/s11431-010-3157-7
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2010-05-01
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Cryogenic techniques are currently used in scanning tunnelling microscopy (STM) and single molecule spectroscopy. Recently such cryogenic devices have also been adapted to time resolved laser-induced fluorescence spectroscopy (TRLFS) systems applied to uranium(VI). In our study, we interpret TRLFS results obtained for the uranyl(VI) glucose system at room temperature (RT) and under cryogenic conditions of 153 K (cryo-TRLFS). A uranyl(VI) glucose complex was only identified by cryo-TRLFS measurements at pH 5 and not by RT measurements. The uranyl(VI) glucose complex was characterized by five emission bands at 499.0, 512.1, 525.2, 541.7, and 559.3 nm and a fluorescence lifetime of 20.9 ± 2.9 μs. The uranyl(VI) glucose complex formation constant was calculated for the first time to be logß_I=0.1 M = 15.25 ± 0.96. Cryo-TRLFS investigation opens up new possibilities for the determination of complex formation constants since interfering quenching effects often encounter at RT are suppressed by measurements at cryogenic conditions.
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Fluorescence spectroscopic study on complexation of uranium(VI) by glucose: a comparison of room and low temperature measurements
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10.1007/s10967-010-0489-5
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2010-04-01
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This paper deals with investigation results on crisis phenomena for nonstationary heat release in falling liquid films. According to the experimental results, in the studied range of irrigation degree alteration (Re_ in = 60–1,690), parameters, characterizing decay of the falling liquid film with stepped heat release (distribution of time of boiling incipience along the liquid film, velocities of movable boundaries in the boiling-up and drying fronts), depend complexly on the Reynolds number, wave characteristics and heat flux density. The time of boiling incipience at stepwise heat release was simulated numerically with consideration of intensive evaporation development from the free surface of a laminar-wave film, transportation of large wave crests at typical process times and influence of the convective component of heat transfer. It is shown that the convective component of heat transfer in the wave liquid films and film thinning because of intensive evaporation provide a significant increase in the time of boiling incipience for the given heat fluxes under the conditions of nonstationary heat release. It is also revealed that for low densities of the heat flux at decay of a laminar-wave liquid film occurs with formation of metastable regular structures with liquid rivulets and large-scale dry zones between them. When loading thermal impulses of high intensity, film decay is determined by dynamic characteristics of propagation of the self-maintained front of liquid boiling-up and the shape of structures, formed during its development.
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Development of Crisis Phenomena in Falling Wavy Liquid Films at Nonstationary Heat Release
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10.1007/s12217-009-9176-y
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2010-04-01
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Cryoprocessing, a supplementary process to conventional heat treatment process, is the process of deep-freezing materials at cryogenic temperatures to enhance the mechanical and physical properties of materials being treated. The execution of cryoprocessing on cutting tool materials increases wear resistance, hardness, and dimensional stability and reduces tool consumption and down time for the machine tool set up, thus leading to cost reductions. The effects of cryoprocessing on tool steels and carbides, metallurgical aspects including reduced amount of retained austenite, precipitation of η-carbides, phase change in carbides, improvement in wear resistance, and applications are reviewed for manufacturing industry. Although it has been confirmed that cryogenic processing can improve the service life of tools, the degree of improvement experienced and the underlying mechanism remains ambiguous. The steps involved in cryoprocessing are critical enough to account for the significant incongruity in post-treated performance.
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Cryoprocessing of cutting tool materials—a review
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10.1007/s00170-009-2263-9
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