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2019-04-06
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This paper presents an evaluation of hybrid cryogenic processes used to eliminate burrs on the exit side of drilled holes in carbon fiber-reinforced plastic composites. These hybrid cryogenic processing methods do not produce environmental hazards and they involve adding a longitudinal ultrasonic motion to the drill cutter and water into a cryogenic environment during the deburring process. There are four methods used for this hybrid cryogenic deburring process: the first method involves ultrasonic vibrations and a cryogenic environment; the second method involves water and a cryogenic environment; the third method involves water, ultrasonic vibrations and a cryogenic environment; and the fourth method involves water, ultrasonic vibrations, a cryogenic environment, and a backup ice layer. The methods were compared in terms of the percentage of removed burrs; the microscopy images of removed burrs are presented in this paper. According to experimental investigations, the fourth method exhibits up to 100% efficiency in removing burrs, followed by the third, the second, and the first method.
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Evaluation of a hybrid cryogenic deburring method to remove uncut fibers on carbon fiber-reinforced plastic composites
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10.1007/s00170-018-3045-z
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2019-04-05
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Steels are subjected to different conventional heat treatment (CHT) processes such as annealing, normalizing, hardening, tempering, quenching, and stress relieving, to improve the mechanical properties and surface coating methods such as electroplating, laser coating, CVD, and PVD, and to enhance the tribological and corrosion properties. Cryogenic treatment is usually performed after CHT to further improve these properties. Components with friction surfaces require high surface hardness in order to resist wear. In this work, EN31 steel used in bearings, spline shafts, and tiller blades, is surface-hardened using gas tungsten arc (GTA). To further improve the hardness, cryogenic treatment was done. GTA torch uses thoriated tungsten (2%) electrode to apply the heat on the friction surface. The welding current and angle of the electrode tip were varied to obtain different heat inputs during surface hardening process. Cryogenic treatment was done for five different soaking periods at − 50 °C [shallow cryogenic treatment (SCT)] and − 196 °C [deep cryogenic treatment (DCT)]. Shallow cryogenic treatment was performed using dry ice, and deep cryogenic treatment was performed using liquid nitrogen. Micro-hardness and microstructures of the specimen were studied. Microstructure study shows that considerable amount of retained austenite has been transformed to plate martensite with precipitates of carbide particles, increasing the hardness of the surface. Surface hardness increases with current and soaking period. The maximum hardness is obtained at 200 A for all electrode tip angles. The maximum hardness is obtained at 15 h of soaking period. Specimens treated at − 190 °C were found to exhibit higher hardness than specimens treated at − 50 °C. Further, 200 A welding current with 45° electrode tip angle and 15 h of soaking period for both SCT and DCT is found to produce maximum hardness.
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Improving Surface Hardness of EN31 Steel by Surface Hardening and Cryogenic Treatment
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10.1007/s40033-019-00177-2
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2019-04-02
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In order to improve the comprehensive mechanical properties, deep cryogenic treatment (DCT) prior to aging was carried out on friction-stir-welded (FSW) 2198 Al–Li alloy; afterward, the microstructure and tensile properties were characterized by means of optical microscopy (OM), transmission electron microscopy (TEM) and tensile testing. The results show that FSW 2198 alloy through DCT prior to aging (DAT) possesses superior tensile properties than conventional aging treatment (AT). The microstructural analysis reveals that DAT alloy exhibits a finer grain structure, since DCT might effectively alleviate the residual stress in FSW 2198 alloy and thus decrease the driving force for grain coarsening in subsequent aging process. Moreover, DCT generates dislocation multiplication, which provides more preferential nucleation sites for T1 (Al_2CuLi) phase during subsequent aging treatment, resulting in high-density fine T1 phases and thin precipitate-free zone within DAT alloy. Such reasonable microstructure leads to DAT alloy possessing better strength-ductility combination compared to AT alloy.
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Comprehensive tensile properties improved by deep cryogenic treatment prior to aging in friction-stir-welded 2198 Al–Li alloy
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10.1007/s12598-019-01214-5
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2019-04-01
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Abstract The microhardness of VT1-0 titanium subjected to megaplastic deformation by torsion under a high hydrostatic pressure at room and cryogenic temperatures and its corrosion resistance in a 1 M solution of HCl are studied. It is shown that megaplastic deformation changes the passivation ability of titanium during anodic polarization: dissolution peaks appear in polarization curves and increase with the deformation.
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Effect of Megaplastic Deformation in a Bridgman Chamber at Various Temperatures on the Corrosion Resistance of VT1-0 Titanium
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10.1134/S0036029519040074
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2019-04-01
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A study is made of the present-day levels of global ^137Cs deposition in permafrost soils of the tundra and taiga zones of Yakutia. It is shown that the reserves of ^137Cs in the soils of Yakutia vary over a significant range according to the landscape and climatic features of the territory. The largest amount of ^137Cs is contained in soils of the mountain areas (Aldan Highlands and Ulakhan-Chistai Range) located in the zone with maximum average annual precipitation amount, and the smallest amount occurs in the soils of the tundra zone. It is found that the average density of soil pollution by ^137Cs in the flat study areas of the territory of Yakutia has now decreased by a factor of 3 to 4 in general when compared with data of airborne gamma-ray spectrometric surveys conducted during 1968–1974 on the territory of the Yakut ASSR, due to its radioactive decay, burial, removal from the surface waters and accumulation by vegetation. It is shown that in the surveyed areas of the plains and mountains of Yakutia, the global deposition of ^137Cs in soils is, on average, by a factor of 2–4 less than in the soils of Ural, Western and Southern Siberia and other territories of Russia. A correlation between the density of soil pollution by ^137Cs and the atmospheric precipitation amount was revealed. The main regularities of ^137Cs migration and redistribution were established in different types of soils of the areas of cryogenic landscapes associated by the runoff. In the harsh climatic conditions of Yakutia, vertical and lateral migration of ^137Cs is weaker in frozen soils than in soils of the European part of Russia contaminated by radioactive cesium after the accident at the Chernobyl nuclear power plant.
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Geographical Features of Pollution of the Territory of Yakutia With Cesium-137
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10.1134/S1875372819020082
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2019-04-01
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Various climatic parameters (average annual, winter, and summer air temperature, winter and summer total precipitation) and their temporal variability are analyzed to explain the activation of cryogenic processes in Central Yamal. The effect of fluctuations of these parameters on the thaw depth and ground temperature is analyzed. The regression analysis is carried out to reconstruct ground temperature during earlier periods of time in the years preceding the activation of thermal denudation and the formation of gas emission craters.
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Activation of Cryogenic Processes in Central Yamal as a Result of Regional and Local Change in Climate and Thermal State of Permafrost
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10.3103/S1068373919040083
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2019-03-15
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We present the performance of a superconducting nanowire that can be operated in two detection modes: (i) as a kinetic inductance detector (KID) or (ii) as a single-photon detector (SPD). Two superconducting nanowires developed for use as single-photon detectors (SNSPDs) are embedded as the inductive (L) component in resonant inductor/capacitor (LC) circuits coupled to a microwave transmission line. The capacitors are low loss commercial chip capacitors and limit the internal quality factor of the resonators to approximately $$Q_i = 170$$ Q i = 170 . The resonator quality factor, $$Q_r \simeq 23$$ Q r ≃ 23 , is dominated by the coupling to the feedline and limits the detection bandwidth to on the order of 1 MHz. When operated in KID mode, the detectors are AC biased with tones at their resonant frequencies of 45.85 and 91.81 MHz. In the low-bias, standard KID mode, a single photon produces a hot spot that does not turn an entire section of the line normal but only increases the kinetic inductance. In the high-bias, critical KID mode, a photon event turns a section of the line normal and the resonance is destroyed until the normal region is dissipated. When operated as an SPD in Geiger mode, the resonators are DC biased through cryogenic bias tees and each photon produces a sharp voltage step followed by a ringdown signal at the resonant frequency of the detector which is converted to a standard pulse with an envelope detector. We show that AC biasing in the critical KID mode is inferior to the sensitivity achieved in DC-biased SPD mode due to the small fraction of time spent near the critical current with an AC bias.
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Operation of a Superconducting Nanowire in Two Detection Modes: KID and SPD
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10.1007/s10909-018-2075-0
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2019-03-08
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A single FCC phase 40Fe–25Ni–15Cr–10Co–10V high-entropy alloy was designed, fabricated, and evaluated for potential cryogenic applications. The alloy forms a single FCC phase and exhibits higher yield strength, tensile strength, and elongation at cryogenic temperature (77 K) than at room temperature (298 K). The superior tensile properties at cryogenic temperature are discussed based on the formation of deformation twins during the tensile test at cryogenic temperature. In addition, a constitutive model reflecting the cryogenic deformation mechanism (i.e., twinning-induced plasticity) was implemented into the finite element method to analyze this behavior. Experimental results and the finite element analysis suggest that the increase in plastic deformation capacity at cryogenic temperature contributes to the formation of deformation twins.
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Plastic Deformation Behavior of 40Fe–25Ni–15Cr–10Co–10V High-Entropy Alloy for Cryogenic Applications
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10.1007/s12540-018-0184-6
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2019-03-01
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Abstract The thermal state of the current leads containing high-temperature superconductors is analyzed. The transition to the normal state of superconductor in a contact connection with an uncooled resistive section of the current lead is considered. The expressions were obtained that determine the temperature and heat flux in the current lead under overloading at different values of transient electrical resistance in the heat-insulated or cooled by a cryogenic liquid brazed joint. Based on the proposed calculation technique, the behavior of the maximum temperature in the resistive section and of the maximum temperature in the contact depending on the current density are revealed when the ratio is changing between the transient resistance and the longitudinal resistance of the contact. It is revealed that if the transient resistance is determined mainly by the transverse resistance of a solder, with minimal nonconductive intracontact formations, then, when the current density increases, the critical parameter that determines the efficiency of the current lead is the maximum temperature of resistive section. The considered method for studying the thermal behavior of the current lead with a high-temperature superconducting wire under overloading conditions can be used for comparative evaluation of the current leads of superconducting devices to determining the values of limiting temperatures in the current lead given different design and physical parameters.
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The Thermal State of High-Temperature Supercondacting Current Leads during Disarrangement of Superconductivity
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10.3103/S1068371219030064
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2019-03-01
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Liquid nitrogen (LN_2) fracturing is a promising new technology for unconventional reservoir simulation because it can effectively solve problems related to low permeability, low brittleness, and water shortage. The present work conducted a series of permeability and strength property-related experiments to evaluate the effect of LN_2 cooling on the permeability and mechanical characteristics of anisotropic shale. The main findings of the study are as follows: (1) The influence of the bedding direction on the permeability of anisotropic shale cannot be eliminated by LN_2 cooling. LN_2 cooling could effectively increase the initial natural damage and the pore space of anisotropic shale, possibly increasing the volume of reservoir stimulation and provide more channels for the seepage and migration of oil and gas. (2) After LN_2 cooling, the strength and brittleness of shale are obviously reduced, leading to the decrease in the ability of shale to resist deformation and failure, thereby helping to decrease the initiation pressure of reservoir stimulation. (3) The brittleness of shale will markedly increase during cryogenic fracturing, thus helping to form more complex fracture networks. Based on the present research, LN_2 fracturing has obvious advantages compared with hydraulic fracturing in increasing the volume of reservoir stimulation. The results of this study are instructive for understanding the synergistic mechanism of LN_2 fracturing and evaluating the effectiveness of reservoir simulation.
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Effect of liquid nitrogen cooling on the permeability and mechanical characteristics of anisotropic shale
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10.1007/s13202-018-0509-5
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2019-02-26
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In recent years, a new generation of composite materials has been introduced as metal matrix composites (MMCs) in order to simultaneously provide higher strength and stiffness. Industrial interests resulted in deep investigations and researches on machinability of MMCs and especially in the field of high-speed machining. High-speed machining processes offer a higher machining efficiency and reduced cost of the process, which made them the process of interest in many manufacturing industries. However, matrix reinforcement by addition of hard particle phases to the MMCs significantly increases machining difficulty, tool wear, surface quality deterioration and overall fabrication costs. In the current research, the cutting speed, feed rate, depth of cut, presence of cryogenic coolant and their effect on the tool wear of high-speed machining of Al/SiC MMC reinforced with 15 wt% SiC particles have been investigated. The results have shown that silicon carbide particles in the aluminum matrix cause a severe tool wear. However, the severity of tool wear has decreased by applying a cryogenic cooling.
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Evaluation of tool wear in high-speed face milling of Al/SiC metal matrix composites
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10.1007/s40430-019-1649-3
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2019-02-15
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We have measured the low-temperature shear piezoelectric and dielectric constants of single-crystal lithium niobate ( $$\hbox {LiNbO}_{3}$$ LiNbO 3 ) and lead magnesium niobate–lead titanate (PMN-PT), and of ceramic lead zirconium titanate (PZT-5A) transducers between room temperature and 78 mK. The piezoelectric and dielectric coefficients $$d_{15}$$ d 15 and $$K^{\sigma }_{15}$$ K 15 σ all decrease with temperature, although the total change in $$d_{15}$$ d 15 is only about 7% for $$\hbox {LiNbO}_3$$ LiNbO 3 . The values of $$d_{15}$$ d 15 for PZT-5A and PMN-PT are much larger at room temperature but decrease much more rapidly, by factors of 4 for PZT-5A and 10 for PMN-PT. For $$\hbox {LiNbO}_3$$ LiNbO 3 , $$d_{15}$$ d 15 is constant below 50 K, but in both PZT-5A and PMN-PT $$d_{15}$$ d 15 continues to decrease nearly linearly to the lowest temperatures. The behavior of the dielectric constant of each material mirrors that of $$d_{15}$$ d 15 , reflecting their common ferroelectric origins. The piezoelectric voltage constants $$g_{15}$$ g 15 are similar in the three materials and are only weakly temperature dependent. For actuator applications where large displacements are needed, PMN-PT and PZT-5A have much larger $$d_{15}$$ d 15 values than $$\hbox {LiNbO}_3$$ LiNbO 3 , but this advantage essentially disappears at low temperatures and $$\hbox {LiNbO}_3$$ LiNbO 3 is a better choice in many applications. For sensor applications where $$g_{15}$$ g 15 determines a transducer’s output voltage, the three materials have similar sensitivity for high-frequency applications like ultrasonics. At low frequencies, however, they are less sensitive as voltage sensors and the use of charge or current amplifiers is preferable.
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Shear Piezoelectric and Dielectric Properties of
$${\hbox {LiNbO}}_{3}$$
LiNbO
3
, PMN-PT and PZT-5A at Low Temperatures
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10.1007/s10909-018-2097-7
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2019-02-15
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Leaf springs are mechanical elements responsible for supporting the vertical load on heavy duty vehicles. For this critical structural component, the required mechanical performance depends mainly on chemical composition and heat treatment. SAE 5160 and SAE 6140 steels are widely used as springs, because after heat treatments, the strength requirements of impact and fatigue are obtained. 51CrV4-ACF steel is another spring steel option which also exhibits excellent mechanical properties. The objective of this work was to study the influence of conventional heat treatments and cryogenic treatment on properties involving fatigue and impact resistance of spring steels. Furthermore, fracture toughness was measured for these materials, and the fracture surfaces were analyzed. The results showed that the cryogenic cycles used did not provide positive effects on spring steel performance. On the other hand, the chemical composition and the application of cleanliness technology promoted higher mechanical strength: Fracture toughness of 51CrV4-ACF was 100% higher than SAE 5160 steel.
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Influence of Deep Cryogenic Treatment on the Mechanical Properties of Spring Steels
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10.1007/s11665-019-3864-6
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2019-02-11
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A cryogenic triple-offset butterfly valve, which is installed in LNG marine engine, controls flow of liquid nitrogen (− 196 °C) to liquefy natural gas (− 163 °C). The existing seal has dual-layer structure composed of rubber and metal seals. The rubber seal is needed to be frequently replaced owing to its low durability, and elasticity of the metal seal decreases in the cryogenic environment, so that leakage of the nitrogen occurs. In order to offer a combination of compressible and resilient materials that form a strong sealing performance in the cryogenic environment (− 196 °C), a new type of seal was devised by laminating muti-layers (graphite and stainless steel). The airtightness of the laminated seal was estimated by comparing contact pressure that occurs on surface of the seal with working pressure. Effects of design parameters in relation to the laminated seal were analyzed to improve sealing performance, and after that a shape of laminated seal to improve operability and airtightness was suggested. Also, the proposed model obtained from FEA was verified through hydraulic and cryogenic leakage tests.
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Design of Laminated Seal in Cryogenic Triple-Offset Butterfly Valve Used in LNG Marine Engine
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10.1007/s12541-019-00056-6
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2019-02-02
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The present study aims to investigate the tool wear mechanism of TiAlN-/NbN-coated tungsten carbide insert during end milling of hard Ti alloy under cryogenic treatment at 24 h and 48 h. The output responses are examined by looking at the flank wear, tool wear mechanism, elemental composition analysis, cutting force and vibration acceleration signal. A 12–23% and 4–11% reduction in the flank wear was noted at 48-h and 24-h cryogenically treated inserts (CTI) when compared with untreated insert. The reduction in the cutting force and vibration was also observed in the CTI when compared with untreated insert. The results showed better machinability and enhanced tool life for CTI, which is better than untreated insert under the same set of working conditions.
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Experimental investigation of tool wear in cryogenically treated insert during end milling of hard Ti alloy
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10.1007/s40430-019-1612-3
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2019-02-01
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In the present work, a tool holder design has been modified and fabricated, which act as a jet stream tool holder for supplying the cryogenic coolant (liquid nitrogen) to both rake and flank faces of cutting tool simultaneously in a novel way. The present work investigated the effect of cryogenic coolant and turning process parameters on cutting temperature (T), tool flank wear (V_b), material removal rate (MRR) and surface integrity (surface roughness (R_a), surface topography (ST) and microhardness (H)) when it is supplied through the modified tool holder (Mode-I) while machining of 17-4 precipitated hardened stainless steel (PH SS) material and results were compared with the cryogenic coolant supplied at the machining zone with one external nozzle (Mode-II) respectively. Experimental results revealed that Mode-I (proposed cooling approach) significantly reduced the T and V_b wear to a maximum of 61% and 29% respectively when compared to cryogenic cooling with Mode-II approach. It was also found that cryogenic cooling with Mode-I approach affected the surface and subsurface characteristics positively over the cryogenic cooling with the Mode-II approach, which leads to substantial improvement in the final product performance respectively.
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The Effectiveness of a Novel Cryogenic Cooling Approach on Turning Performance Characteristics During Machining of 17-4 PH Stainless Steel Material
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10.1007/s12633-018-9875-3
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2019-02-01
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In this investigation, the influence of cryogenic treatment on the tribological properties of Cu-Be2 alloy was investigated. Deep cryogenic treatment and shallow cryogenic treatment were applied to Cu-Be2 alloy. As-received (AR), shallow cryogenic treated (SCT) and deep cryogenic treated (DCT) Cu-Be2 alloy were used as pin material. AISI 4140 alloy steel hardened to 513 HV was used as disc. Wear test was carried out using pin-on-disc wear test set-up and the wear tracks were examined using Scanning Electron Microscope. Wear rate and coefficient of friction of the cryogenic treated sample were lower than that of the as-received sample. Adhesive wear, plastic deformation and delamination of asperities were found to be the principal mechanism in the wear characteristics on the as-received as well as the cryogenic treated samples.
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Enhancing Wear Resistance of Cryo Treated Cu-Be2 Alloy
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10.1007/s12633-018-9835-y
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2019-01-30
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The present work is an endeavor to carry out a machining using LN_2 in face milling operations and to produce the milling samples with excellent wear resistance property. The output response (wear rate) depends on appropriate choice of speed, feed, and depth of cut. The experimental data are conducted (collected) for SS316 as per central composite design. The present work exemplifies an employment of conventional and nonconventional strategies for optimizing the milling factors of cryogenically treated samples in face milling to achieve the desired wear (response). The results of nonlinear regression (desirability strategy) and nonconventional [particle swarm optimization, (PSO)] optimization techniques are compared, and PSO is found to outperform the desirability function approach. The present work even highlights the effect and results of LN_2 on wear in contrast to wet condition.
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An Efficient Approach to Optimize Wear Behavior of Cryogenic Milling Process of SS316 Using Regression Analysis and Particle Swarm Techniques
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10.1007/s12666-018-1473-y
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2019-01-17
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Resistance thermometers show saturation effects at temperature below around 20 mK. A simple method to extend the range of low temperature resistance thermometers is proposed. The temperatures to be measured are shifted to an upper range where the resistance thermometer does not saturate. The shifting is controlled by an electrically supplied power which heats a metal–insulator junction. A simple mathematical relation between the temperature of interest and the temperatures measured by the resistance thermometer was found for measured temperatures between 20 mK and 60 mK. The difference between the temperatures measured by a calibrated CMN thermometer and the values obtained from the proposed method was evaluated as less than 0.5 %.
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A Simple Method to Extend the Range of Low Temperature Resistance Thermometers
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10.1007/s10765-019-2482-8
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2019-01-15
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Cryogenic rare event searches based on heat and light composite calorimeters have a common need for large area photon detectors with high quantum efficiency, good radiopurity and high sensitivity. By employing the Neganov–Trofimov–Luke effect, the phonon signal of particle interactions in a semiconductor absorber operated at cryogenic temperatures can be amplified by drifting the photogenerated electrons and holes in an electric field. We present here the most recent results of a Neganov–Trofimov–Luke effect light detector with an electric field configuration optimized to improve the charge collection within the absorber.
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Silicon PIN Diodes as Neganov–Trofimov–Luke Cryogenic Light Detectors
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10.1007/s10909-018-2067-0
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2019-01-10
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This paper presents an efficient and robust numerical framework to deal with multiphase real-fluid flows and their broad spectrum of engineering applications. A homogeneous mixture model incorporated with a real-fluid equation of state and a phase change model is considered to calculate complex multiphase problems. As robust and accurate numerical methods to handle multiphase shocks and phase interfaces over a wide range of flow speeds, the AUSMPW+_N and RoeM_N schemes with a system preconditioning method are presented. These methods are assessed by extensive validation problems with various types of equation of state and phase change models. Representative realistic multiphase phenomena, including the flow inside a thermal vapor compressor, pressurization in a cryogenic tank, and unsteady cavitating flow around a wedge, are then investigated as application problems. With appropriate physical modeling followed by robust and accurate numerical treatments, compressible multiphase flow physics such as phase changes, shock discontinuities, and their interactions are well captured, confirming the suitability of the proposed numerical framework to wide engineering applications.
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Methods for compressible multiphase flows and their applications
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10.1007/s00193-018-0829-x
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2019-01-02
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Abstract Alloys of nickel are optimal metals to use in turbine parts and aircraft components. They are generally accepted as difficult-to-machine materials, because of its poor thermal conductivity. The selection of coolant and machining conditions is crucial for better performance. Problems with conventional coolant are failure of lubrication at higher metal removal and cause environmental pollution. The heat produced at the cutting zone can shorten the life of the tool, which leads to dimensional imprecision. The current experimental investigation is machining of Nimonic 80A under the effect of cryogenic liquid carbon dioxide (− 79.5 °C) using PVD-TiAlN coated tungsten carbide (WC) insert, which is compared with conventional dry, flood, and MQL environments. The machining is carried at varying cutting speed ranging from 45 to 90 m/min, a feed rate of 0.06–0.08 mm/tooth, and a constant depth of cut of 0.75 mm. The results admitted that cryogenic cooling lessens the average roughness by 42–47% over dry cutting, 24–27% over wet cutting, and 16–21% over MQL. It is proved that cryogenic cooling produces greater compressive stress on the machined surface and brings down the flank wear by decreasing the temperature on the cutting zone. Graphical abstract
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Effect of cryogenic coolant on machinability of difficult-to-machine Ni–Cr alloy using PVD-TiAlN coated WC tool
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10.1007/s40430-018-1552-3
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2019-01-01
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To alleviate the global warming issue arising from emission of greenhouse gases involving CO_2 through burning of fossil fuels CO_2 recovery and its utilization and storage has been known as an appropriate choice. With this purpose in mind, various CO_2 recovery methods have been applied recently including adsorption, membrane, hydrating, chemical looping, biofixation, and absorption. Among these strategies, cryogenic CO_2 capture technique has been become more attractive. However, there are some challenges including capture cost, impurities and cold energy sources which encounter utilization of this technique. In this investigation, the major technologies and strategies of capturing CO_2 which is exhausted from the combustion of fossil fuels are summarized, and also the features of cryogenic routes for CO_2 capture have been reviewed. Also, the future prospect of the improved cryogenic processes is discussed. According to the consequences of this study, cryogenic CO_2 capture methods can be utilized for the industrial scale and eliminate the problems associated with physical sorbents and chemical solvents. Also the integration of two or more conventional CO_2 capture technologies can minimize the disadvantages of standalone process. These processes, named as hybrid system, compared to the standalone technology indicated the superiority in terms of energy penalty, the installation investment, and CO_2 recovery.
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Cryogenic CO_2 Capture
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10.1007/978-3-030-29337-6_10
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2019-01-01
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High-wear-resisting EN 31 bearing steel has been widely used to make components such as roller bearing, ball bearing, spline shaft, and other components like tiller blades, punches and dies are subjected to severe abrasion to require high surface hardness. To obtain high surface hardness, EN 31 steel is usually surface modified using various methods like conventional heat treatment (591 HV), cryogenic treatment (688 HV) and GMAW. But, there are no studies on surface modification of EN 31 using gas tungsten arc (GTA) heat source followed by cryogenic treatment. To improve the hardness further, surface alloying using gas tungsten arc followed by cryogenic treatment is done in this study. EN 31 steel is surface-hardened by using GTA heat source by varying the welding current, electrode tip angle and shallow and deep cryogenic treatments (SCT & DCT) by varying soaking time and temperature. Microstructures were studied and microhardness was measured. It is found that cryogenic treatment leads to formation of carbide particles in martensite matrix with reduced retained austenite which improves the microhardness from 258 to 898 HV after SCT and 1856 HV for DCT. Further, in this work, a back-propagation artificial neural network (ANN) which uses gradient descent learning algorithm is used to predict the microhardness of EN 31 steel for the entire ranges of parameters used in the experiments. The ANN model is trained and tested using 200 experiments done. The input parameters of the ANN model are 4 variables (welding current, electrode tip angle, cryogenic soaking time and temperature). Using MATLAB, a programme was developed and by varying the transfer function (tansig and logsig) different ANN models are constructed for the prediction of microhardness. This study shows that back-propagation artificial neural network (ANN) which uses gradient descent learning algorithm is very efficient for predicting the microhardness of EN 31 steel.
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Effect of Surface Modification Using GTAW as Heat Source and Cryogenic Treatment on the Surface Hardness and Its Prediction Using Artificial Neural Network
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10.1007/978-981-13-1724-8_18
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2019-01-01
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The feature of all cryogenic equipment is that they operate at extremely low temperatures. Typically, a liquid gas flows through or is stored in such devices. In order to ensure that such processes are technically and economically viable, each cryogenic device must have high quality thermal insulation which will reduce heat inleaks into the cryogen. Therefore, the vast majority of cryogenic devices employ vacuum insulation, which entails the need to use an additional vessel on the outside of the vessel or the pipes in which the cryogen is stored. Mechanical calculation of the cryogenic equipment should include both the vacuum vessel loaded with external pressure and the cryogenic vessel loaded with internal pressure. Additionally, the calculations should include potential emergency states and loads during the equipment production tests. This paper presents all the described aspects of mechanical calculations on the example of the FRESCA2 (Facility for Reception of Superconducting Cables) test station currently under design in collaboration between European Organization for Nuclear Research CERN (Switzerland) and Wroclaw University of Science and Technology (Poland)
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Aspects of the Cryogenic Equipment Mechanical Calculations on an Example of the FRESCA2 Cryostat
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10.1007/978-3-030-04975-1_21
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2019-01-01
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High and medium entropy alloys are currently attracting significant research interest due to their potential to achieve superior mechanical properties compared to traditional alloys systems. The CoCrNi alloy has been of particular interest owing to the simple single phase structure, superior fracture toughness, and exceptional strength and ductility at cryogenic temperatures. Previous works have been primarily focused on identifying the operative microstructural mechanisms responsible for improved ductility. The activation of deformation twining at low deformation temperatures and high strains has been identified as a primary source for the improved ductility. However, detailed quantitative analysis focused on the deformation heterogeneities in the vicinity of grain boundaries, in particular at cryogenic temperatures, remains limited. Strain heterogeneities across grain boundaries reveal the micro-mechanisms responsible for the alloy strengthening and fracture properties, thus their measurements is of fundamental importance. The current work is dedicated to study the local strain accumulation in the vicinity of grains boundaries of plastically deforming CoCrNi. High resolution digital image correlation was used to measure and quantify the deformation heterogeneities at room temperature (298 K) and cryogenic temperature (77 K). The work aims to further elucidate the role of grain boundaries in improving the strength and ductility at cryogenic deformation temperatures.
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Sub-grain Plastic Strain Localization in CoCrNi Medium Entropy Alloy at Cryogenic Temperatures
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10.1007/978-3-030-21894-2_9
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2019-01-01
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Solid (Friction) stir welding (FSW) is a moderately new welding practice, and it is a widely adopted process used to join metallic alloys. It is a fad in automobile, aerospace, and further manufacturing concern for linking complex geometry of joints. The present research paper, the influence of cryogenic cool (dry ice and liquid nitrogen) on grain refining and tensile and microhardness property of 2014 Al FSWed is demonstrated. Cryogenic coolant process was employed in friction stir welding to reduce the grain size that observed by using an optical microscope as 2–4 µm (average size) and to improve the mechanical properties which are obtained higher properties with tool shoulder diameter of 24 mm, taper cylindrical thread pin profile at a rotational speed of 900 rpm, and a welding speed of 60 mm/min due to equiaxed grains of FSWed 2014 aluminum alloy. By cryogenic process, it is observed that mechanical properties are enormously improved. Scanning electron microscopy (SEM) helps for the quality and high-resolution fractography analysis of a cryogenic-processed FSWed Al 2014 plates.
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Effect of Cryogenic Coolant on Mechanical Properties and Micrographs of Solid State Welding of 2014 Al Plates
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10.1007/978-981-13-7643-6_9
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2019-01-01
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The present study is to investigate the role of cryogenic cooling using liquid nitrogen as coolant on the tool wear and surface roughness in turning of Inconel 625 with PVD-TiAlN-coated carbide inserts. The machining parameters of the experimental works were cutting conditions (dry and cryogenic cooling), cutting speeds (43, 71, 118 m/min), feed rate (0.1 mm/rev), and cutting depth (1 mm). The surface roughness ( R _a) was significantly improved to a maximum of 50.52% by cryogenic cooling with the current cutting parameters. The scanning electron microscope (SEM) investigation of the used cutting inserts revealed the substantial reduction in tool wear under cryogenic cooling compared to dry turning in all the machining trails undertaken.
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Effectiveness of Cryogenic Cooling in Turning of Inconel 625 Alloy
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10.1007/978-981-13-1724-8_54
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2019-01-01
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The main emphasis of the research is to analyse the variation in the behaviour of properties of steel after the combined heat and cryogenic treatment. Preheat treatment was done, where the steels were kept at 600 °C for 60 min and then was quenched using saline bath, followed by the cryogenic treatment at 77 K. For the proper comparison of the variation of properties, the cryogenic treatment of steel was carried out at varying soaking time steps of 2, 4, 6 and 8 h for appropriate analysis of the material. Using optical microscopy, it was observed that as compared to the untreated steels, the impacts of combined heat and cryogenically treated samples were having an excellent microstructure and surface texture. The presence of saturated austenite was initially higher for the untreated material but was found to be lowering with the increase in cryogenic soaking time of material. SEM examination visibly specifies the formation of fine and coarse grains on treated and untreated steels, respectively. Microhardness of cryogenically treated materials was amplified by around 29%, when subjected to combined heat and cryogenic treatment. XRD analysis was done to analyse the variation in the friction coefficient for both the sets of specimens, and it was found that 8 h cryogenically treated specimens were having significantly reduced coefficient of friction as compared to untreated steels.
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Experimental Analysis of the Influence of Combined Heat and Cryogenic Treatment on Mechanical Properties of Steel
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10.1007/978-981-13-1780-4_32
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2019-01-01
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Aluminium and its alloys have been the centre of interest to the engineer’s community due to their high strength to weight ratio, high wear resistance, low coefficient of thermal expansion and ease of manufacture. To fulfil the increasing requirement of lighter weight, yet excellent mechanical properties than aluminium alloys, addition of grain refiners with modifiers to the alloys has been proposed. Al–Si alloy was taken as the master alloy, while magnesium and copper were added individually with a tint of modifiers and grain refiner. Two sets of same specimens of varying composition were prepared. One set of samples was annealed and the other underwent deep cryogenic treatment (DCT) followed by tempering. Wear behaviour of Al–Si alloys was analysed before and after the DCT by using the computerized ‘pin on disc’ wear testing machine. After cryogenic treatment, all the specimens, except those containing grain refiners showed influence on wear resistance.
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Influence of Deep Cryogenic Treatment on the Wear Behaviour of Different Al–Si Alloys
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10.1007/978-981-13-1780-4_22
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2019-01-01
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Whole-head MEG systems based on the low-Tc SQUID sensors utilize liquid helium to reach the temperature around 4 K. Until recent years, a typical MEG system needed a liquid helium refill once or twice per week. However, the increasing cost and the lack or limited availability of liquid helium for regular fillings have motivated commercial MEG manufacturers to develop zero-boiloff systems that maintain the low temperature without losing helium. In this section, we present the challenges, history, and state of the art of low helium consumption systems which employ a compact helium liquefier in open-loop, closed-loop, or integrated configurations. In addition we discuss possibilities for the future in liquid helium-free systems incorporating cryocoolers.
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Zero Helium Boiloff MEG Technology
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10.1007/978-3-319-62657-4_79-1
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2019-01-01
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Due to the defects of active water fracturing fluid properties and the particularity of coal in the structure and mechanical properties, the conventional hydraulic fracturing is not applicable to high-rank coal seam, which is prone to the problems of excessive extension of fracture height, short effective propped fracture length. This paper introduces cryogenic technology into the coalbed methane(CBM) fracturing and puts forward a new cryogenic volume fracturing technology, whose mechanism is: alternative injecting water and cryogenic fluid by small rate to freeze the water in the fracture and cleat, temporary plugging fracture to divert, forming complex fracture networks to increasing CBM production. In this paper, the discrete element method (DEM) is adopted to establish a two-dimensional fracture propagation model to simulate cryogenic volume fracturing in CBM. The different injection temperature and pressure are simulated to study fracture propagation rules. The results show that with injection pressure increasing and temperature reducing, fracture networks become more complex and larger. Cryogenic volume fracturing can form ice temporary plugging to effectively increase the network complexity and SRV.
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Research on Fracture Propagation by Cryogenic Volume Fracturing Based on Dem
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10.1007/978-981-10-7560-5_152
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2019-01-01
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Rapidly growing economy and its consequence of relying heavily on the fossil fuels, for power generation, accounts for the major CO_2 pollutant in the atmosphere. Natural carbon cycle process will not be effective in reducing the pollutant content, as the amount and rate of CO_2 dissipation raise at a drastic rate. This alarming situation urgently requires technologies for carbon dioxide capture and sequestering (CCS). With the development of technologies every day, the amount of CO_2 emission is expected to increase steeply, which necessitates more technologies to sequester CO_2 with a target of 50 ppm by 2050. CCS involves the capture of gas at some stage of the industrial process followed by pressurization and transporting it to stable geological sites like saline aquifers, depleted oil and gas fields, deep coal seams where it can be trapped for thousands of years. CO_2 sequestration requires multiple fundamental R&D approaches and significant breakthroughs. The purpose of this review is to have an integrated analysis of the carbon sequestration process including the state of the art technologies for CO_2 capture, separation, transport, storage, leakage, monitoring, and life cycle analysis. Depending on the source of emission, different techniques and methodologies adopted by the scientific community were analyzed and discussed. A brief description of the best practices and techniques for CO_2 capturing like absorption, adsorption, cryogenic, and membranes will be reviewed. A comparative study on the same will be analyzed based on their performance, efficiency, regeneration, adsorption rate, the volume of adsorption, cost, and energy required for regeneration. Some of the prerequisites for sequestering the captured carbon dioxide are safety, environmentally benign, effective, economical, and acceptable to the public. Natural sequestration methods include plantation, soil carbon sequestration, and CH_4-CO_2 reforming. Industrially acceptable sequestration process involves isolating the captured gas into places which are nonaccessible to living creatures which include basically geologic, oceanic, and terrestrial dumping sites. All the three geoengineering techniques and their subdivisions will be discussed in detail with up to date improvisations and results. Moreover, the concerns related to potential leakages while transporting supercritical CO_2, uncertainty in terms of quantification of storage potential, accompanied by monitoring and engineering challenges have to be given prior attention in developing any sequestration process, which this review will give an overall picture and suggestions.
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CO_2 Sequestration: Processes and Methodologies
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10.1007/978-3-319-68255-6_6
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2019-01-01
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Cold temperatures have been used in medicine for several decades, mainly for therapeutic purposes in several fields. The underlining physic principle is the “Joule-Thomson” effect: it is a phenomenon in which the temperature of a real gas increases or decreases following, respectively, its compression or its expansion—as a result from a pressure difference—that is carried out without extracting a work. Different cryogenic gases have been used so far.
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Cryobiopsy: Physics
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10.1007/978-3-030-14891-1_4
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2019-01-01
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Continued development of superior soft-magnetic alloys Alloys has resulted in improved efficiencies in key technologies, viz., electric motors, generators, transformers, etc. In this work, we present the magnetic Magnetic properties properties Properties of a low-cobalt content, soft-magnetic alloy—CarTech^® Hypocore™ Alloy CarTech^® Hypocore™ Alloy —at cryogenic temperatures Cryogenic temperatures , that has a unique combination of low coercivity and a high electrical resistivity at ambient temperature. Specimens were cut from the cold-rolled strips (thickness ~130 μm). The X-ray diffraction spectrum revealed the presence of α -phase (bcc solid solution of iron), at 300 K. Magnetic characterization Characterization from 60 to 300 K was performed on annealed specimens. The saturation magnetization Saturation magnetization decreased from ~221 Am^2/kg (at 60 K) to ~216 Am^2/kg (at 300 K), while the intrinsic coercivity Intrinsic coercivity varied between ~220 and ~230 A/m in that temperature regime. The magnetic saturation at 0 K and the magnetic moment per atom for the alloy were estimated as ~221.2 Am^2/kg and ~2.17 μ _B, respectively. The observed soft-magnetic behavior of the alloy at cryogenic temperatures Cryogenic temperatures was compared with the other soft-magnetic alloys Alloys .
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Magnetic Characterization of CarTech^® Hypocore™ Alloy at Cryogenic Temperatures
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10.1007/978-3-030-05749-7_21
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2019-01-01
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Materials with high strength and light in weight are in demand in high-precision manufacturing. Machining these materials becomes tedious in extreme cutting conditions where cutting fluids sometimes fail. Hence an alternate method of cooling is needed to replace the conventional coolant. This paper presents the effects of cryogenic coolants in turning of Hastelloy C276. This alloy finds its major applications in sophisticated applications like nuclear reactors, pressure vessels and heat exchangers. The present approach was carried out to develop a comparative study between two cryogenic coolants (liquid nitrogen and carbon dioxide). Experiments were performed using Taguchi L9 orthogonal technique, and the parameters considered were speed, feed rate and depth of cut. Better output in terms of surface finish was observed in liquid nitrogen when compared to carbon dioxide.
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Experimental Investigation on Machining Parameters of Hastelloy C276 Under Different Cryogenic Environment
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10.1007/978-981-32-9417-2_20
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2019-01-01
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In this work, the enhancement of wear performance of cryogenic treated (CT) as-cast AZ91 reinforced with 1.5 wt% WC magnesium metal matrix nano-composite (Mg-MMNC) had been explored using pin-on-disc tribometer and scanning electron microscope (SEM). AZ91 with 1.5 wt% WC reinforcement was prepared with stir casting process and the cryogenic treatment was carried out at −190 °C. The wear test parameters were the applied normal loads of 20 and 40 N, sliding velocities of 1.0, 1.6, 2.1 and 3.1 m/s and a constant slipping distance of 1200 m with tribo-couples of aluminium disc and Mg-MMNC pin at atmospheric conditions. At lower loads, almost all the samples had showed the similar wear loss. But in higher loads, there was significant reduction in wear loss for cryogenic treated Mg-MMNC. The presence of reinforcement and increased Mg_17Al_12 phase particles volume fraction due to CT had significantly enhanced the wear resistance of composite. There was also wear loss in counter-part aluminium disc. The SEM analyses of worn surface indicate that there was abrasion and oxidation. And a changeover occurred from oxidation wear to delamination wear and abrasion wear while the applied load was increased from 20 to 40 N. Adhesion wear took place at the sliding condition of load 40 N and speed 3.1 m/s.
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Influence of Cryogenic Treatment on As-Cast AZ91+1.5 wt%WC Mg-MMNC Wear Performance
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10.1007/978-981-13-1780-4_19
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2019-01-01
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The possibilities and prospects of laser generation in active media based on organic dyes that are cooled to cryogenic temperatures are considered. The results demonstrate the possibility of creating highly effective active laser media (based on the analog of the Shpol’sky matrix) on the basis of cooled carbon-containing matrices.
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Development of a Laser Generator Based on the Analog of the Shpol’sky Matrix
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10.3103/S0027134919010041
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2019-01-01
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Food gases are supplied to the food industry as additives, support or in contact with food ingredients. Consequently, these gases must respect very strict standards in order to come into contact with foodstuffs and therefore in order to ensure food security. In particular, they must comply with precise rules on labelling, purity and hygiene criteria. The relevant legislation was inspired by the White Paper on Food Safety, published in 2000 by the European Commission which has defined the environmental, public health, animal health and consumer protection as joint objectives, freedom of competition. The Regulation (EC) No 178/2002 defines a food as any substance produced, processed or distributed to be ingested, or reasonably expected to be ingested. Food gases are used in the food industry in different applications. This chapter considers the role of food gases in Europe on the regulatory ground with several observations concerning basic features, food safety approaches, classifications and conditions for use.
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Food Gases: Classification and Allowed Uses
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10.1007/978-3-030-35228-8_1
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2019-01-01
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SNARE-mediated membrane fusion is required for membrane trafficking as well as organelle biogenesis and homeostasis. The membrane fusion reaction involves sequential formation of hemifusion intermediates, whereby lipid monolayers partially mix on route to complete bilayer merger. Studies of the Saccharomyces cerevisiae lysosomal vacuole have revealed many of the fundamental mechanisms that drive the membrane fusion process, as well as features unique to organelle fusion. However, until recently, it has not been amenable to electron microscopy methods that have been invaluable for studying hemifusion in other model systems. Herein, we describe a method to visualize hemifusion intermediates during homotypic vacuole membrane fusion in vitro by transmission electron microscopy (TEM), electron tomography, and cryogenic electron microscopy (cryoEM). This method facilitates acquisition of invaluable ultrastructural data needed to comprehensively understand how fusogenic lipids and proteins contribute to SNARE-mediated membrane fusion-by-hemifusion and the unique features of organelle versus small-vesicle fusion.
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Visualization of SNARE-Mediated Organelle Membrane Hemifusion by Electron Microscopy
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10.1007/978-1-4939-8760-3_24
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2019-01-01
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Shape memory alloys (SMAs) are considered as difficult-to-machine materials. This chapter sheds light on machinability Machinability aspects of SMAs and presents a comprehensive discussion on advanced and sustainable strategies and techniques for machining SMAs. It commences with an introduction to machinability, challenges of SMAs and possible solutions before discussing implementation of machining strategies and techniques to enhance machinability. The chapter ends with an outlook and selected avenues for possible future research capabilities of SMAs machining. As regards to the advanced machining of SMAs, the major focus of this chapter is on electric discharge (electric discharge), laser beam, and abrasive water jet machining. Whereas, in sustainable machining section, the use of advanced cooling and lubrication strategies during conventional turning, milling, drilling, and grinding of SMAs are emphasized. Some aspects of a recent experimental research conducted on MQL-assisted turning of NiTi shape memory alloy are also included in this chapter.
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Machining of Shape Memory Alloys
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10.1007/978-3-319-99307-2_2
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2019-01-01
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Cooling the tool cutting edge during the machining of titanium is indispensable for an economical and productive process. Innovative cooling processes using carbon dioxide (CO_2) or liquid nitrogen (LN_2) can further increase tool life, especially when machining materials with low thermal conductivity. When drilling with high length to diameter ratio tools, cooling of the cutting edge is only possible via an internal supply of the cryogenic medium. Previous system solutions relied on the method of passing the cooling medium through the tool spindle. This paper presents an innovative approach that enables the supply of liquid carbon dioxide as a cooling medium to a drilling tool without passing it through the tool spindle. The operating behaviour in idle speed at different spindle speeds is shown and, additionally, its suitability for drilling processes is presented by means of a chip analysis.
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Innovative Chuck with Integrated Rotary Feed-Through for Drilling Process with Application of Cryogenic Cooling
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10.1007/978-3-030-03451-1_28
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2019-01-01
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Mechanical components are subjected to wear during their functionality, which decreases the life of such components. The mechanical strength plays a major role for the same. Different heat treatments had been used to improve the mechanical strength of such components. In this paper, DCT (Deep cryogenic treatment) with post-tempering treatment was conducted on austenitic steel SS316 and its effect on mechanical as well as metallurgical properties was investigated through experimental testing’s. For post-tempering, two temperatures were selected (T_1: 350 °C and T_2: 250 °C). It was observed that the DCT samples with post-tempered treatment at T_2: 250 °C possess good tensile strength and hardness. The reason behind the same can be refinement of grains after DCT with tempered at T_2: 250 °C as seen from the microstructural analysis. Further, decrease in toughness was also observed for both the DCT samples. The conversion from austenitic grains to martensitic grains was also observed after DCT.
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Effect on Mechanical and Metallurgical Properties of Cryogenically Treated Material SS316
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10.1007/978-981-13-6287-3_7
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2019-01-01
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The aim of this study is to investigate the effects of cryogenic Cryogenic process (CP) on the properties of 2024-T6 aluminum Aluminum alloy. So, samples were held at −40 °C medium for 24 h in CP after solution heat treatment. Finally, samples were subjected to aging process at 120 °C for 8 h after CP. Furthermore, aging process was carried out after 0, 1, and 4 h later after CP. Examination of microstructure Microstructure was executed by SEM, EDS, and optical microscope (OM) observations. Hardness Hardness tests were also conducted through HV. Improvement in metallurgical properties of 2024-T6 aluminum Aluminum alloy was tested with these parameters, in detail.
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Improvement in Metallurgical Properties of Gravity Die Cast 2024-T6 Aluminum Alloy via Cryogenic Process
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10.1007/978-3-030-06034-3_25
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2019-01-01
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A micro heater with low temperature coefficient of resistance (TCR) at liquid hydrogen temperature was designed and fabricated by micro fabrication technology. The NiCr heater annealed in N_2 at 250 °C for 9 min achieves a smallest TCR of 9.36 ppm/K at 20 K. The crystal structures of NiCr film annealed in nitrogen were analyzed by scanning electron microscope (SEM) and X-ray diffraction (XRD). The crystallization of NiCr film improved with the annealing temperature increasing. The fabricated micro heater applied in the temperature control test achieves the accuracy of ±0.5 mK, which is qualified for the temperature control accuracy requirement of the ignition target of inertial confinement fusion (ICF).
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Micro Heater with Low Temperature Coefficient of Resistance for ICF Target
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10.1007/978-3-030-37429-7_49
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2019-01-01
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In the present industrial scenario, manufacturing has become the backbone for the growth of any country. The advancement in manufacturing technology and methodology adopted has led to industrial growth, but it has some adverse effects on environment Environment as well on human being such as environmental pollution and production of poisonous gases. Therefore, it is essential to find a sustainable manufacturing solution which is eco-friendly, highly productive, and economical from all aspects for human being’s comfort and environment Environment . Cryogenic Cryogenic machining is one of the best sustainable substitutes for conventional machining. Major defects due to high temperatures can be reduced because of excellent coolant properties of cryogenic Cryogenic materials which slowed down the heat generation at the interface of tool and workpiece. This chapter introduces cryogenic Cryogenic machining and sheds light on its various important aspects along with presenting its comparison with the other machining methods based on different material properties, viz. surface finish, cutting temperature, and tool life.
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Cryogenic Machining
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10.1007/978-3-030-03276-0_2
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2019-01-01
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Magnesium and its alloys are slowly entering into the field of bio-implants as a substitute to currently used materials because of their mechanical properties and physiological benefits. However, the magnesium alloys corrode much before than the bone is fully healed because of their high corrosion rate in physiological environment of body. In this experiment, AZ31B magnesium alloy has been subjected to turning operation under dry and cryogenic environment. This research is an attempt to study the effects of cutting speed and feed rate on forces, surface roughness, temperature and microstructure. Furthermore, a comparative study is done on the effects of machining environment on these factors. The results show that a combination of high cutting speed and low feed rate with cryogenic environment gives the best surface finish.
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Cryogenic Machining of AZ31B Magnesium Alloy for Bio-implant Applications
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10.1007/978-981-32-9417-2_19
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2019-01-01
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In this paper, a novel cooling strategy for machining is presented: a metalworking fluid, composed of water and a polyhydric alcohol is supplied to the cutting zone at temperatures above the temperatures used for cryogenic machining, but below 0 °C. This sub-zero metalworking fluid (MWF) is applied when turning AISI 4140 at varied cutting speed. The results are compared with those obtained using emulsion, cryogenics as well as dry turning. An analysis of temperatures, forces, tool wear as well as surface roughness is carried out. The use of the novel sub-zero MWF results in low tool temperatures and tool wear. In contrast to cryogenic and dry machining, a constant surface roughness was observed in the case of severe tool wear.
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Turning of AISI 4140 (42CrMo4): A Novel Sub-zero Cooling Approach
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10.1007/978-3-030-03451-1_31
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2018-12-12
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Deep cryogenic treatment (DCT) has been acknowledged as an approach to modify metallic materials properties to enhance their performance. The effects of deep cryogenic treatment parameters (cryogenic temperature, cooling rate, soaking time and tempering temperature) on microstructure, mechanical properties and machining performance of Ti (N, C)–Al_2O_3-coated cemented carbide insert have been comprehensively investigated in this paper. First, microstructure examination results show that a decarburization phase was detected and the WC particles were refined after deep cryogenic treatment. Secondly, the hardness of the WC–Co substrate and the wear resistance of the coatings after DCT were elevated. In addition, the transformation from α -Co to ε -Co was observed, which is highly dependent on cryogenic temperature and soaking time. Finally, dry milling experiments were carried out and the results indicated that the tool wear resistance was improved and the experimentally measured cutting forces had lower values using cryogenically treated insert, which can be attributed to the dissolution of Co into WC yielding microplastic deformation as well as the enhanced wear resistance. This research can provide guidance for optimizing DCT parameters of coated carbide insert to acquire desired mechanical properties and improve cutting performance.
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Effect of deep cryogenic treatment on microstructure, mechanical properties and machining performances of coated carbide tool
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10.1007/s40430-018-1533-6
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2018-12-06
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The rejuvenation behavior of an Zr_50Cu_40Al_10 (at.%) metallic glass upon cryogenic cycling treatment has been investigated. At a high casting temperature, the microstructure of the glass is quite homogenous and thus, internal stress cannot be generated during cycling. Therefore, the glass cannot be rejuvenated by cryogenic cycling treatment. In the contrary, by lowering the casting temperature, nano-sized heterogeneity can be induced and subsequently generates the internal stress and rejuvenates the glass. Once the glass is rejuvenated, the more induced free volume can plasticize the glass with a higher plastic strain. These findings point out that the synthesis conditions can tailor the heterogeneity of the glass and subsequently affect the following rejuvenation behavior upon thermal treatment. It can also help understand the mechanisms of rejuvenation of metallic glass upon cryogenic cycling treatment.
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Various Rejuvenation Behaviors of Zr-Based Metallic Glass by Cryogenic Cycling Treatment with Different Casting Temperatures
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10.1186/s11671-018-2816-7
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2018-12-06
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Background The malaria Eradication Research Agenda (malERA) has identified human-to-mosquito transmission of Plasmodium falciparum as a major target for eradication. The cornerstone for identifying and evaluating transmission in the laboratory is standard membrane feeding assays (SMFAs) where mature gametocytes of P. falciparum generated in vitro are offered to mosquitoes as part of a blood-meal. However, propagation of “infectious” gametocytes requires 10–12 days with considerable physico-chemical demands imposed on host RBCs and thus, “fresh” RBCs that are ≤ 1-week old post-collection are generally recommended. However, in addition to the costs, physico-chemical characteristics unique to RBC donors may confound reproducibility and interpretation of SMFAs. Cryogenic storage of RBCs (“cryo-preserved RBCs”) is accepted by European and US FDAs as an alternative to refrigeration (4 °C) for preserving RBC “quality” and while cryo-preserved RBCs have been used for in vitro cultures of other Plasmodia and the asexual stages of P. falciparum , none of the studies required RBCs to support parasite development for > 4 days. Results Using the standard laboratory strain, P. falciparum NF54, 11 SMFAs were performed with RBCs from four separate donors to demonstrate that RBCs cryo-preserved in the gaseous phase of liquid nitrogen (− 196 °C) supported gametocytogenesis in vitro and subsequent gametogenesis in Anopheles stephensi mosquitoes. Overall levels of sporogony in the mosquito, as measured by oocyst and sporozoite prevalence, as well as oocyst burden, from each of the four donors thawed after varying intervals of cryopreservation (1, 4, 8, and 12 weeks) were comparable to using ≤ 1-week old refrigerated RBCs. Lastly, the potential for cryo-preserved RBCs to serve as a suitable alternative substrate is demonstrated for a Cambodian isolate of P. falciparum across two independent SMFAs. Conclusions Basic guidelines are presented for integrating cryo-preserved RBCs into an existing laboratory/insectary framework for P. falciparum SMFAs with significant potential for reducing running costs while achieving greater reliability. Lastly, scenarios are discussed where cryo-preserved RBCs may be especially useful in enhancing the understanding and/or providing novel insights into the patterns and processes underlying human-to-mosquito transmission.
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Cryogenically preserved RBCs support gametocytogenesis of Plasmodium falciparum in vitro and gametogenesis in mosquitoes
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10.1186/s12936-018-2612-y
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2018-12-03
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Background In superconductive linear accelerator, the performance and stability can be impacted by gas adsorbed on cryogenic surfaces adversely. The cryogenic devices usually work at 4.2 K or 1.9 K and are refrigerated by normal or super fluid liquid helium, respectively. Purpose The purpose of this paper is to study the character of gas migration in cryogenic tubes. Method Adsorption coefficient for hydrogen at 4.2 K is measured by experimental study. Then, a gas migration model is established based on the experimental results to depict the hydrogen migration process in cryogenic tubes. Results The experimental results and model analysis indicated that at cryogenic temperature (4.2 K), adsorption coefficient for hydrogen is very close to 1, which is several orders higher than the adsorption coefficient at room temperature, resulting in a unique pressure distribution pattern in cryogenic tubes when compared with the pressure distribution in room temperature tubes. Conclusions At 4.2 K or 1.9 K, the gas migration process is obviously different from the process at room temperature and is significantly affected by the gas adsorption on the cryogenic surfaces. The model established in this article can be applied not only to hydrogen migration in cryogenic tubes but also to other gas migration in tubes with high adsorption coefficient.
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The hydrogen migration in cryogenic tubes of superconductive accelerator with gas source
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10.1007/s41605-018-0086-7
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2018-12-01
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The Super Cryogenic Dark Matter Search is one of the leading experiments in the direct search for weakly interacting massive particles in the mass range below 10 GeV/c^2. Particles are detected in cryogenic semiconductor detectors; their energy deposition produces phonons and liberates charges which are measured in TES-based phonon sensors and charge-collecting electrodes. The next generation of the experiment will be deployed at SNOLAB and aims to further reduce the detection threshold to a few tens of eV by reducing the noise in the readout circuit and improving the design of the phonon sensors. Traditionally, radioactive sources are used to calibrate the energy scale and to monitor detector stability. However, in most cases, it takes a long time to accumulate enough events to identify peaks in the energy spectrum. Moreover, gammas of low energy as would be required to calibrate the bottom range of the detector’s energy range cannot penetrate the cryostat shielding. This study investigates the possibility of using pulsed infrared LEDs mounted inside the cryostat as alternative calibration source.
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Feasibility Study for an IR-LED-Based Calibration System for SuperCDMS Detectors
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10.1007/s10909-018-1996-y
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2018-12-01
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The X-ray Astronomy Recovery Mission (XARM) is a recovery mission of ASTRO-H/ Hitomi , which is expected to be launched in Japanese Fiscal Year of 2020 at the earliest. The Resolve instrument on XARM consists of an array of 6 × 6 silicon-thermistor microcalorimeters cooled down to 50 mK and a high-throughput X-ray mirror assembly with the focal length of 5.6 m. Hitomi was launched into orbit in February 2016 and observed several celestial objects, although the operation of Hitomi was terminated in April 2016. The soft X-ray spectrometer (SXS) on Hitomi demonstrated high-resolution X-ray spectroscopy of ~ 5 eV FWHM in orbit for most of the pixels. The Resolve instrument is planned to mostly be a copy of the Hitomi SXS and soft X-ray telescope designs, though several changes are planned based on the lessons learned from Hitomi . We report a brief summary of the SXS performance and the status of the Resolve instrument.
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Resolve Instrument on X-ray Astronomy Recovery Mission (XARM)
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10.1007/s10909-018-1913-4
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2018-12-01
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The CRESST experiment uses cryogenic detectors based on transition-edge sensors to search for dark matter interactions. Each detector module consists of a scintillating CaWO $$_4$$ 4 crystal and a silicon-on-sapphire (SOS) light detector which operate in coincidence (phonon-light technique). The 40-mm-diameter SOS disks (2 g mass) used in the data taking campaign of CRESST-II Phase 2 (2014–2016) reached absolute baseline resolutions of $$\sigma =$$ σ = 4–7 eV. This is the best performance reported for cryogenic light detectors of this size. Newly developed silicon beaker light detectors (4 cm height, 4 cm diameter, 6 g mass), which cover a large fraction of the target crystal surface, have achieved a baseline resolution of $$\sigma = 5.8\,$$ σ = 5.8 eV. First results of further improved light detectors developed for the ongoing low-threshold CRESST-III experiment are presented.
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TES-Based Light Detectors for the CRESST Direct Dark Matter Search
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10.1007/s10909-018-1944-x
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2018-12-01
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The EDELWEISS collaboration is performing a direct search for WIMP dark matter using an array of up to twenty-four 820–890 g cryogenic germanium detectors equipped with a full charge and thermal signal readout. The experiment is located in the ultra-low-radioactivity background environment of the Modane underground laboratory, in the French–Italian Fréjus tunnel. We present the analysis of data obtained in extended data taking periods. WIMP limits, background rejection factors and measurements of cosmogenic activation are used to assess the performance of the third generation of EDELWEISS detectors in view of the search for WIMPs in the mass range from 1 to $$20~\hbox {GeV}/\hbox {c}^{2}$$ 20 GeV / c 2 . The developments in progress to pursue this goal in the coming years are also presented.
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Status and Prospects of the EDELWEISS-III Direct WIMP Search Experiment
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10.1007/s10909-018-1921-4
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2018-12-01
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We describe the design of a cryogenic rotation stage (CRS) for use with the cryogenic half-wave plate (CHWP) polarization modulator on the POLARBEAR-2b and POLARBEAR-2c (PB2b/c) cosmic microwave background (CMB) experiments, the second and third installments of the Simons Array. Rapid modulation of the CMB polarization signal using a CHWP suppresses 1/ f contamination due to atmospheric turbulence and allows a single polarimeter to measure both polarization states, mitigating systematic effects that arise when differencing orthogonal detectors. To modulate the full detector array while avoiding excess photon loading due to thermal emission, the CHWP must have a clear-aperture diameter of > 450 mm and be cooled to < 100 K. We have designed a 454 mm clear-aperture, < 65 K CRS using a superconducting magnetic bearing driven by a synchronous magnetic motor. We present the specifications for the CRS, its interfacing to the PB2b/c receiver cryostat, its performance in a stand-alone test, and plans for future work.
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A Large-Diameter Cryogenic Rotation Stage for Half-Wave Plate Polarization Modulation on the POLARBEAR-2 Experiment
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10.1007/s10909-018-1980-6
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2018-12-01
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The Physics Department of the Technical University of Munich operates a shallow underground detector laboratory in Garching, Germany. It provides $$\sim 160\,{\mathrm{m}^2}$$ ∼ 160 m 2 of laboratory space which is shielded from cosmic radiation by $$\sim 6\,\mathrm{m}$$ ∼ 6 m of gravel and soil, corresponding to a shielding of $$\sim 15\,{\mathrm{m.w.e.}}$$ ∼ 15 m . w . e . . The laboratory also houses a cleanroom equipped with work- and wetbenches, a chemical fumehood as well as a spin-coater and a mask-aligner for photolithographic processing of semiconductor detectors. Furthermore, the shallow underground laboratory runs two high-purity germanium detector screening stations, a liquid argon cryostat and a $$^3$$ 3 He– $$^4$$ 4 He dilution refrigerator with a base temperature of $$\le 12-14\,\mathrm{mK}$$ ≤ 12 - 14 mK . The infrastructure provided by the shallow laboratory is particularly relevant for the characterization of $$\hbox {CaWO}_4$$ CaWO 4 target crystals for the CRESST-III experiment, detector fabrication and assembly for rare event searches. Future applications of the laboratory include detector development in the framework of coherent neutrino nucleus scattering experiments ( $$\nu $$ ν -cleus) and studying its potential as a site to search for MeV-scale dark matter with gram-scale cryogenic detectors.
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A Cryogenic Detector Characterization Facility in the Shallow Underground Laboratory at the Technical University of Munich
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10.1007/s10909-018-1899-y
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2018-12-01
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We describe prototype arrays of magnetically coupled microcalorimeters fabricated with an approach scalable to very large format arrays. The superconducting interconnections and sensor coils have sufficiently low inductance in the wiring and sufficiently high inductance in the coils in each pixel, to enable arrays containing greater than 4000 sensors and 100,000 X-ray absorbers to be used in future astrophysics missions such as Lynx. We have used projection lithography to create submicron patterns (e.g., 400 nm lines and spaces) in our niobium sensor coils and wiring, integrated with gold–erbium sensor films and gold X-ray absorbers. Our prototype devices will explore the device physics of metallic magnetic calorimeters as feature sizes are reduced to nanoscale.
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Magnetic Calorimeter Arrays with High Sensor Inductance and Dense Wiring
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10.1007/s10909-018-1956-6
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2018-12-01
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Nuclear recoil detectors with low energy thresholds of 10–100 eV have applications in both neutrino physics (e.g. coherent elastic neutrino-nucleus scattering and neutrinoless double beta decay) as well as for $$\mathscr {O}$$ O (GeV)-mass dark matter searches. Cryogenic crystal detectors are well suited for these applications, although some require very large masses which can be achieved with arrays of these detectors. An optimization of a design focusing on ease of fabrication and mass production while retaining low energy thresholds is presented. This is achieved by decoupling the complex lithography of the thermal sensor from the large crystal absorber/target, while optimizing the thermal time constants to retain the lowest threshold possible.
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Optimizing Thermal Detectors for Low-Threshold Applications in Neutrino and Dark Matter Experiments
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10.1007/s10909-018-2073-2
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2018-12-01
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Compacted graphite iron (CGI) is replacing conventional cast iron (CI), especially in the automotive industries for the manufacture of a high-performance and light-weight diesel engine due to its outstanding mechanical properties as compared to the conventional CI. Nevertheless, the pace of replacement is still slow because of the low machining performance encountered by the industries during high-speed machining of CGI. Thus, in this study, the effect of various cooling-lubrication strategies in high-speed machining of CGI using uncoated carbide inserts was investigated. Results showed that the combination of indirect cryogenic cooling and minimum quantity lubrication (MQL) improves the tool life by 26% compared to conventional flood coolant strategy. The result has been clarified by monitoring the cutting force and the sound pressure for each cooling/lubrication strategy.
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Effect of cryogenic high-speed milling of compacted graphite iron using indirect spray system
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10.1007/s00170-018-2213-5
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2018-12-01
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We are building a transition edge sensor (TES) X-ray spectrometer for the Linac Coherent Light Source (LCLS-II) at SLAC National Accelerator Laboratory (SLAC) to coincide with new upgrades for this free electron laser facility. This new X-ray spectrometer will have 1000 TES pixels with 0.5 eV energy resolution for soft X-rays below 1 keV. Multiplexing will be done with microwave SQUID resonators and new specialized electronic hardware developed at SLAC. This spectrometer will use a dilution refrigerator to achieve lower operating temperatures than previous TES spectrometers and will be coupled to the liquid jet endstation at LCLS-II. The spectrometer is designed to operate at much higher count rates than previous TES X-ray spectrometers to take advantage of the high repetition rate of the LCLS-II. Science applications will utilize the high photon collection efficiency and throughput, high energy resolution, as well as its ability to simultaneously measure its full calibrated energy range.
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TES X-ray Spectrometer at SLAC LCLS-II
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10.1007/s10909-018-2053-6
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2018-12-01
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The development of lens-antenna-coupled aluminum-based microwave kinetic inductance detectors (MKIDs) and on-chip spectrometers needs a dedicated cryogenic setup to measure the beam patterns of the lens-antenna system over a large angular throughput and broad frequency range. This requires a careful design since the MKID has to be cooled to temperatures below $$300\,\hbox {mK}$$ 300 mK to operate effectively. We developed such a cryostat with a large opening angle $$\theta = \pm \,37.8^\circ $$ θ = ± 37 . 8 ∘ and an optical access with a low-pass edge at $$950\,\hbox {GHz}$$ 950 GHz . The system is based upon a commercial pulse tube cooled 3 K system with a $$^4\hbox {He}$$ 4 He – $$^3\hbox {He}$$ 3 He sorption cooler to allow base temperatures below $$300\,\hbox {mK}$$ 300 mK . A careful study of the spectral and geometric throughput was performed to minimize thermal loading on the cold stage, allowing a base temperature of $$265\,\hbox {mK}$$ 265 mK . Radio-transparent multi-layer-insulation was employed as a recent development in filter technology to efficiently block near-infrared radiation.
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Large Angle Optical Access in a Sub-Kelvin Cryostat
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10.1007/s10909-018-1940-1
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2018-12-01
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This paper presents a numerical model for the hard turning process under the cryogenic cooling condition. This numerical model was developed on the basis of the modified Oxley’s cutting theory with implementing the cryogenic cooling condition. The cooling effect of cryogenic coolant on the tool flank face was modeled as a forced convective heat transfer coefficient as a function of the Nusselt number. The heat generated in the primary and secondary deformation zones was also modeled using moving heat source technique. This model was validated with experimental works under cryogenic and dry conditions for oblique cutting. The minimum and maximum errors in predictions were 1.8 and 15.2% for cutting force (P1), 1.6 and 33.7% for thrust force (P2), and 2.3 and 7.9% for feed force (P3), respectively, under the cryogenic cooling condition. In the case of predicting the temperature at the thermocouple location, the minimum and the maximum errors of these comparisons were 2.0 and 30.5%. It was observed that the cryogenic coolant during the hard turning process reduces the thermal softening effect and in turn increases the cutting forces. In addition, the use of cryogenic coolant can increase the segmented angle ( ϕ _seg) and segmented frequency. Flank wears were observed in both cryogenic cooling and dry conditions. LN2 decreases the length of the flank wear by 12.4~27.5%. In this study, there is the performance improvement of hard turning process by adopting cryogenic cooling method.
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Predictive modeling for the cryogenic cooling condition of the hard turning process
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10.1007/s00170-018-2660-z
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2018-12-01
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This paper presents the first comprehensive investigation that aluminum honeycomb has inevitable machining defect in milling process, such as deformation, burr, and collapse. Ice fixation method was used to clamp workpieces, and inner-injection liquid nitrogen was employed for a series of cryogenic milling machining. In the machining process, the main machining parameters including in honeycomb orientation, milling width, cutting depth, cutting speed, and feed were executed experimental research. Meanwhile, the machining parameter optimization, range, and significant analysis were adopted to analyze the influence of machining parameters on the machining surface quality, as well as the optimal parameter combination and milling machining surface quality were predicted and verified. The results show that the ice fixation aluminum honeycomb method with cryogenic milling is much advanced than that of conventional ones, and many machining defects are effectively restrained. At the same time, the influence of machining parameters on machining qualities in descending order is cutting depth, cutting speed, honeycomb orientation, feed, and milling width. The minimum roughness value (Ra = 0.356 μm) of the predicted machining surface is similar to the actual machining result (Ra = 0.362 μm). It verifies the feasibility of the optimization method. Furthermore, it is proved that the ice fixation + liquid nitrogen cooling method has a positive effect on the high milling quality and implement efficiency for aluminum honeycomb and other difficult-to-machine materials.
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Optimization of cryogenic milling parameters for aluminum honeycomb treated by ice fixation method
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10.1007/s00170-018-2599-0
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2018-11-27
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In the recent years, environmental regulations became stringent in terms of disposal of chemically contaminated conventional coolants. Cryogenic cooling is an alternative technique to the conventional cooling technique with conventional coolants. In this work, new findings were reported in turning of 17-4 precipitation hardenable stainless steel (PH SS) at varying feed rate conditions under cryogenic cooling and the results were compared with the minimum quantity lubrication (MQL), conventional wet and dry cutting conditions, respectively. Turning performance considered in this work includes cutting temperature, surface roughness and tool wear. From the findings, it was noticed that a maximum of 24%, 26% and 69% reduction in surface roughness was observed in cryogenic machining when compared to MQL, wet and dry environments, respectively. Also, the maximum flank wear reduction found in cryogenic machining was 42%, 48% and 53%, respectively, over the MQL, wet and dry environments. Overall, it was concluded that cryogenic machining is a feasible method for improving the turning performance characteristics in machining of 17-4 PH SS.
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Effect of cryogenic coolant on turning performance: a comparative study
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10.1007/s42452-018-0078-8
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2018-11-01
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Understanding the origin and early evolution of stars is one of the fundamental objectives of astronomy. This can be possible with observations made from space in the mid- to far-infrared and millimeter-wave part of the spectrum which require detectors with very high sensitivity. In the framework of the SPICA project and the course of developing cooled semiconductor bolometers for sub-millimeter-wave detection, typically 100 μm ≤ λ ≤ 1.5 mm, we have investigated several thermometers based on doped silicon Si:P,B. We observed an important dependence of the Si:P,B resistance to the doping densities and found potential thermometers for cryogenic detections at very low temperatures (50 mK < T < 100 mK). In addition, numerical simulations allowed us to study the thermoelectrical behavior of the potential detectors and predict a clear enhancement of the detector performances.
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Characterization of Doped Silicon Thermometers for Very High Sensitivity Cryogenic Bolometers
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10.1007/s10909-018-1993-1
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2018-11-01
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We report on the fabrication and characterization of Mo/Au-based transition-edge sensors (TES), intended to be used in X-ray detectors. We have performed complete dark characterization using I – V curves, complex impedance and noise measurements at different bath temperatures and biases. Devices with two designs, different sizes and different membranes have been characterized, some of them with a central bismuth absorber. This has allowed extraction of the relevant parameters of the TES, analyses of their standard behavior and evaluation of their prospects.
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Comparison of Different Mo/Au TES Designs for Radiation Detectors
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10.1007/s10909-018-1936-x
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2018-11-01
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To cope with the future large demand on neutron-transmutation-doped germanium of (NTD) sensors, our groups in LUMINEU started a new production line for NTD-Ge. This paper contains details on the NTD-Ge production, resistance measurement and a comparison of the performance in terms of noise and signal-to-noise ratio with an existing sensor contacts. This demonstrates our ability to produce NTD sensors for the desired range of working temperature.
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NTD-Ge Production in the LUMINEU Experiment Using Cryogenic Detectors for Rare Event Searches and Other Applications
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10.1007/s10909-018-2005-1
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2018-11-01
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Remarkable progress in correlative light and electron cryo-microscopy (cryo-CLEM) has been made in the past decade. A crucial component for cryo-CLEM is a dedicated cryo-fluorescence microscope (cryo-FM). Here, we describe an ultra-stable super-resolution cryo-FM that exhibits excellent thermal and mechanical stability. The temperature fluctuations in 10 h are less than 0.06 K, and the mechanical drift over 5 h is less than 200 nm in three dimensions. We have demonstrated the super-resolution imaging capability of this system (average single molecule localization accuracy of ∼13.0 nm). The results suggest that our system is particularly suitable for long-term observations, such as single molecule localization microscopy (SMLM) and cryogenic super-resolution correlative light and electron microscopy (csCLEM).
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Ultra-stable super-resolution fluorescence cryo-microscopy for correlative light and electron cryo-microscopy
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10.1007/s11427-018-9380-3
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2018-11-01
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Abstract The article discusses the impact of global climate change on the components of the natural environment of the permafrost zone (e.g.., the center of the continental cryolithozone of the Northern Hemisphere). These changes have significantly intensified the dynamics of the climate parameters of the region: the average annual air temperatures, precipitation, and the duration of seasons of the year, which correlates with the dynamics of the active soil layer, the upper layers of cryogenic soils, and the increase in the seasonal thawing depth of soil. In turn, influenced by these factors, the water content of large areas is changing and the relic of Pleistocene glaciations—the ice complex—is degrading. The transformation of the basis for the existence of terrestrial ecosystems—the soil cover and, on the whole, the landscape located on the ice complex—indicates irreversible changes in the entire natural environment of the continental cryolithozone. Climate warming affects the living components of nature, causing the expansion of many animal and plant species from south to north. Taking into account the fact that the cryolithozone occupies more than 60% of Russian territory and is a repository of natural resources, a new approach to planning and conducting scientific research, as well as economic activity, in the permafrost zone is particularly relevant.
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Climate Change and Dynamics of Permafrost Ecosystems of the Center of the Continental Cryolithozone of the Northern Hemisphere
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10.1134/S1019331618060072
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2018-11-01
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In the present scenario, metal cutting industries are looking for alternative cooling techniques to conventional cooling to satisfy the stringent environment regulations as well as lower productivity problems while machining of difficult to cut materials. Cryogenic machining is a novel eco-friendly as well as efficient cooling techniques. In present work, an attempt has been made to study the effect of process parameters on turning performance characteristics and the development of correlation models between the input process parameters and output responses while machining of difficult to cut materials 17-4 precipitated hardened stainless steel (PH SS) using response surface methodology (RSM) under the cryogenic cooling environment. The turning process parameters considered in the present study are cutting velocity ( v ), feed rate ( f ) and depth of cut ( d ) whereas responses are tool flank wear (V_b), surface roughness (R_a) and material removal rate (MRR) respectively. RSM based face centered central composite design (CCD) experimental design has been used to perform the experiments. From the conformation test results, it was observed that very good agreement was found between the actual and predicted values, which represent that the developed predictive models are well effective with a maximum of ± 5% error.
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Analysis and Modeling of Cryogenic Turning Operation Using Response Surface Methodology
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10.1007/s12633-018-9816-1
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2018-11-01
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We present a model to calculate heat signal shapes from low-temperature bolometer attached to a crystal. This model is based on the elementary acoustic wave theory at low temperature and has been developed using modern Monte Carlo techniques. Physical processes in phonon propagation, such as transmission, scattering and reflection are considered. Using our model, the calculated time dependence of signal agrees with real experimental data. This model has applications in low-temperature rare event particle detectors for dark matter and neutrinos.
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A Model on Heat Signal of Crystal Detector at Low Temperature
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10.1007/s10909-018-2003-3
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2018-11-01
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The CRESST-III experiment (Cryogenic Rare Events Search with Superconducting Thermometers), located at the underground facility Laboratori Nazionali del Gran Sasso in Italy, uses scintillating CaWO $$_4$$ 4 crystals as cryogenic calorimeters to search for direct dark matter interactions in detectors. A large part of the parameter space for spin-independent scattering off nuclei remains untested for dark matter particles with masses below a few GeV/c $$^2$$ 2 , despite many naturally motivated theoretical models for light dark matter particles. The CRESST-III detectors are designed to achieve the performance required to probe the low-mass region of the parameter space with a sensitivity never reached before. In this paper, new results on the performance and an overview of the CRESST-III detectors will be presented, emphasizing the results about the low-energy threshold for nuclear recoil of CRESST-III Phase 1 which started collecting data in August 2016.
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A Low Nuclear Recoil Energy Threshold for Dark Matter Search with CRESST-III Detectors
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10.1007/s10909-018-1948-6
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2018-11-01
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Acoustic emission response of fossil coals being at different stages of metamorphism to cyclic variation of effective thermal stresses is experimentally investigated. The equipment and procedure used in the experiments are described. The features of the response are revealed and analyzed in the samples of anthracite, lignite and bituminous coal with different damage extent governed by the preliminary cyclic freezing and thawing, as well as by water saturation. It is shown that the signature of such features is a thermal analog of the Felicity effect which appears in each cycle of temperature action. The regularities of this effect are found, and their physical explanation is given based on the analysis of defect formation in coals at different stages of thermal treatment. The methodical approaches are proposed and substantiated, which allow structural damage, thermal resistance, oxidation and proneness to frost weathering of coal to be estimated by the Felicity effect in the acoustic emission response of coal to cyclic thermal forces. Possibility of using the found features to predict structural changes in coal products which are in long-term storage under specific climatic conditions, as well as for forecasting risk of self-heating and spontaneous combustion of coal products is discussed.
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Effect of Thermal Memory in Acoustic Emission in Fossil Coal after Pre-Disintegration by Cryogenic Treatment
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10.1134/S1062739118065023
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2018-11-01
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The electronic assembly considered in this study is an infrared (IR) detector consisting of different layers, including (111) CdHgTe and (100) silicon single crystals. The processing steps and the low working temperature (77 K) induce thermomechanical stresses that can affect the reliability of the thin and brittle CdHgTe detection circuit and lead to failure. These residual stresses have been quantified in both CdHgTe and silicon circuits at room temperature (293 K) and cryogenic temperature using x-ray diffraction. A specific experimental device has been developed for 77 K measurements and a method developed for single-crystal analysis has been adapted to such structures using a laboratory four-circle diffractometer. This paper describes the methodology to obtain the deformed lattice parameter and compute the strain/stress tensors. Whereas the stresses in the CdHgTe layer appear to be negative at room temperature (compressive values), cryogenic measurements show a tensile biaxial stress state of about 30 MPa and highlight the great impact of low temperature on the mechanical properties.
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X-ray Diffraction Residual Stress Measurement at Room Temperature and 77 K in a Microelectronic Multi-layered
Single-Crystal Structure Used for Infrared Detection
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10.1007/s11664-018-6560-7
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2018-11-01
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We report on the performance of a cryogenic 2D linear ion trap (cryoLIT) that is shown to be mass-selective in the temperature range of 17–295 K. As the cryoLIT is cooled, the ejection voltages during the mass instability scan decrease, which results in an effective mass shift to lower m/z relative to room temperature. This is attributed to a decrease in trap radius caused by thermal contraction. Additionally, the cryoLIT generates reproducible mass spectra from day-to-day, and is capable of performing stored waveform inverse Fourier transform (SWIFT) mass isolation of fragile N_2-tagged ions for the purpose of background-free infrared dissociation spectroscopy. Graphical Abstract ᅟ
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Operation and Performance of a Mass-Selective Cryogenic Linear Ion Trap
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10.1007/s13361-018-2026-7
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2018-10-13
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Background The in vivo observation of diffusible components, such as ions and small phenolic compounds, remains a challenge in turgid plant organs. The analytical techniques used to localize such components in water-rich tissue with a large field of view are lacking. It remains an issue to limit compound diffusion during sample preparation and observation processes. Results An experimental setup involving the infusion staining of plant tissue and the cryo-fixation and cryo-sectioning of tissue samples followed by fluorescence cryo-observation by laser scanning confocal microscopy (LSCM) was developed. This setup was successfully applied to investigate the structure of the apple fruit cortex and table grape berry and was shown to be relevant for localizing calcium, potassium and flavonoid compounds. Conclusion The cryo-approach was well adapted and opens new opportunities for imaging other diffusible components in hydrated tissues.
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Cryo-laser scanning confocal microscopy of diffusible plant compounds
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10.1186/s13007-018-0356-x
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2018-10-01
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The effect of cryorolling on the precipitation process of deformed Cu–Ni–Si alloys was investigated through in situ synchrotron X-ray diffraction technique. The results demonstrate that the precipitation process is significantly accelerated by cryorolling. Cryorolling produces higher dislocation density, which provides more heterogeneous nucleation sites for Ni_2Si precipitates, hence promotes precipitation. In the early stage of aging, the enhanced nucleation of precipitates accelerates the depletion of supersaturation, and finer precipitates are obtained. In addition, recrystallization is promoted as a result of high stored energy in the cryorolled Cu–Ni–Si alloys, which facilitates the formation of discontinuous precipitation in the late stage of aging.
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Influence of Cryorolling on the Precipitation of Cu–Ni–Si Alloys: An In Situ X-ray Diffraction Study
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10.1007/s40195-018-0781-x
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2018-10-01
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We have used different metallic magnetic calorimeter (MMC) gamma detectors to measure the low-energy emissions of ^233U with an accuracy of a few eV. ^233U is of interest in nuclear safeguards because it is a fissile isotope that is produced by neutron irradiation of ^232Th in the thorium fuel cycle. However, some of the nuclear decay data of ^233U in the literature have relatively high uncertainties, especially at lower energies where lines can overlap or be dominated by a high Compton background. MMC gamma detectors operated at a temperature of 10 mK can have an energy resolution below 50 eV and can resolve lines with similar energy and reduce these uncertainties. We present recent MMC measurements of ^233U and discuss the contributions of statistical and systematic errors. Importantly, we have performed the experiments with different MMC gamma detectors and different SQUID readout systems to increase the confidence in some observed deviations from literature values. The consistency of the results suggest that observed deviations are not due to detector artifacts and that a predictable quadratic response is intrinsic to the properties of MMCs.
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Consistent measurements of ^233U gamma emissions using metallic magnetic calorimeters with ultra-high energy resolution
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10.1007/s10967-018-6182-9
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2018-10-01
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Plasma etching is a powerful technique for transferring high-resolution lithographic patterns into HgCdTe material with low etch-induced damage, and it is important for fabricating small-pixel-size HgCdTe infrared focal plane array (IRFPA) detectors. P - to n -type conversion is known to occur during plasma etching of vacancy-doped HgCdTe; however, it is usually unwanted and its removal requires extra steps. Etching at cryogenic temperatures can reduce the etch-induced type conversion depth in HgCdTe via the electrical damage mechanism. Laser beam-induced current (LBIC) is a nondestructive photoelectric characterization technique which can provide information regarding the vertical and lateral electrical field distribution, such as defects and p – n junctions. In this work, inductively coupled plasma (ICP) etching of HgCdTe was implemented at cryogenic temperatures. For an Ar/CH_4 (30:1 in SCCM) plasma with ICP input power of 1000 W and RF-coupled DC bias of ∼ 25 V, a HgCdTe sample was dry-etched at 123 K for 5 min using ICP. The sample was then processed to remove a thin layer of the plasma-etched region while maintaining a ladder-like damaged layer by continuously controlling the wet chemical etching time. Combining the ladder etching method and LBIC measurement, the ICP etching-induced electrical damage depth was measured and estimated to be about 20 nm. The results indicate that ICP etching at cryogenic temperatures can significantly suppress plasma etching-induced electrical damage, which is beneficial for defining HgCdTe mesa arrays.
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Inductively Coupled Plasma-Induced Electrical Damage on HgCdTe Etched Surface at Cryogenic Temperatures
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10.1007/s11664-018-6172-2
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2018-10-01
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The secondary phases of the steels have significant effects on the microstructure and mechanical properties, making controlling these secondary phases important. The control of MnS inclusions and AlN precipitates in a N-alloyed high-Mn twin-induced plastic cryogenic steel via solution treatment was investigated with several different techniques including microstructural characterization, 298 K tensile testing, and 77 K impact testing. The solutionizing temperature (ST) increased from 1323 to 1573 K, where the elongated MnS inclusions and large-sized AlN precipitates became spheroidized and dissolved. The aspect ratio of the MnS inclusions decreased as the ST increased and the number density increased. The impact toughness of the steels showed anisotropy and low impact energy values, due to the elongated MnS inclusions and large-sized AIN precipitates. The anisotropy was eliminated by spheroidizing the MnS inclusions. The impact energy was improved by dissolving the large-sized AlN precipitates during the solution treatment. The austenite grain size increased when the dissolution of the AlN precipitate increased, but the effect of the grain size on the yield strength, toughness, and the strength–ductility balance was weak.
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Control of Secondary Phases by Solution Treatment in a N-Alloyed High-Mn Cryogenic Steel
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10.1007/s40195-018-0759-8
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2018-10-01
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目的 低温风洞运行时大流量低温氮气被排放到大气环境中,对周围环境造成潜在的低温、缺氧危险。 本文旨在研究羽流扩散过程中各变量(环境风速、环境风温度、相对湿度和排气出口流速)对 羽流沉降的影响。 创新点 采用考虑相变的低温羽流扩散模型,通过数值模拟对影响羽流扩散的各参数进行敏感性分析。 方法 1. 基于Hertz-Knudsen 关系修正,考虑空气中水的相变,构建低温羽流扩散的数值模型;2. 对照 美国National Transonic Facility的羽流扩散数据 和NASA 的二阶分析模型的计算结果,验证本文 所采用的数值模型的准确性;3. 利用数值模拟, 比较不同排放条件下近地面的最低氧含量和最低温度,并对各变量进行敏感性分析。 结论 1. 考虑相变的羽流扩散数值模型,相比NASA 的二阶分析模型拥有更好的准确性。2. 对于0.3 m低温风洞的羽流扩散,高环境风速有利于羽流消散;高环境温度和高相对湿度能提升近地面的最 低温度,但对近地面的最低氧含量影响甚微。 3. 当排气速度小于2 kg/s 时,排气流速增大不利于羽流消散;当羽流速度大于2 kg/s 时,排气流速增大有利于羽流消散。 The low temperature plume exhausted from a cryogenic wind tunnel may sink down, posing a severe threat to public health and safety. Quantitative risk assessment of cryogenic plume flow behavior therefore plays an important role in the design and optimization of a cryogenic wind tunnel. A numerical model with a modified Hertz-Knudsen relation considering the phase change physics of the small quantity of water involved is applied to analyze the dispersion of the low temperature nitrogen plume exhausted from a 0.3 m cryogenic wind tunnel. The homogeneous multiphase flow is modeled using the single-fluid mixture model. A model validation is presented for the exhaust plume from the US National Transonic Facility (NTF). The predicted results are found to be better than those predicted by National Aeronautics and Space Administration (NASA)’s two-stage analytical model. The influences of the environmental wind speed, the environmental wind temperature, the relative humidity, and the exhaust flow rate, on low temperature nitrogen plume dispersion are obtained. In particular, the parametric sensitivities of different influence factors are analyzed. The environmental wind temperature and the exhaust flow rate of the nitrogen gas have greater impact on the temperature of the plume near the ground than do the environmental wind speed and the relative humidity. The exhaust flow rate of the nitrogen gas has greater impact on the oxygen concentration near the ground than does the environmental wind speed, while the environmental wind temperature and the relative humidity have negligible impacts. The results provide guidance on the operation and design improvement of a cryogenic gaseous nitrogen discharge system to avoid its potential hazards.
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A parametric sensitivity study by numerical simulations on plume dispersion of the exhaust from a cryogenic wind tunnel
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10.1631/jzus.A1700632
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2018-10-01
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Annealing of the submicrocrystalline (SMC) structure of niobium obtained by high pressure torsion to e = 7 at the temperature of liquid nitrogen was carried out. The influence of the annealing temperature in the range of 100–1100°C on the recrystallization of the SMC structure and the formation of texture was investigated. This paper discusses the role of static recovery and thermoactivated formation of recrystallization nuclei. The submicrograined recrystallized structure characterized by an average grain size of 0.8 μm, by a high homogeneity, and by the lack of the texture has been obtained. The sharpest recrystallization texture is formed as a result of annealing at 900°C; the average grain size is 10 μm in this case.
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Structure and Microtexture of Niobium Recrystallized after Cryogenic Deformation by Shear under Pressure
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10.1134/S0031918X18100137
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2018-09-24
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Polymers with reversible elongation upon cooling (EUC) and contraction upon heating (CUH) enabled applications in actuators, fasteners, dampers, grippers, swimmers, sealants, etc. With the current working temperature being limited to mainly above zero Celsius, applications for subzero Celsius environments are obstructed. In addition, current reversible actuation needs a constant tensile load, or for the best case, under zero tensile load. Reversible EUC and CUH under compressive load is almost impossible and has not been explored. In this work, a cis poly(1,4-butadiene) based system has been developed. Actuated below zero Celsius, 69% EUC occurred under a tensile load; and 6.2% EUC and 17.9% CUH occurred under 0.05 MPa compressive load. The reversible actuation was driven by both entropy and enthalpy, which was validated by a series of characterization tools.
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Giant reversible elongation upon cooling and contraction upon heating for a crosslinked cis poly(1,4-butadiene) system at temperatures below zero Celsius
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10.1038/s41598-018-32436-9
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2018-09-05
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Risers are multilayer structures used in oil production and transportation. The pressure armor is the layer responsible for supporting the internal radial pressure and is produced from a helical interlocked steel wire. The interlocking mechanism, which gives flexibility to the riser, is responsible for the wear on the pressure armor, resulting in a micro-abrasive wear. The present work aims to study the effect of deep cryogenic treatment and plasma nitriding on the micro-abrasive wear in the pressure armor. Samples tested were taken from the contact region of the pressure armor. The micro-abrasive wear test was performed on a free ball machine. The tests were conducted on the samples as received, with deep cryogenic treatment and with plasma nitriding (at 515 °C for 8, 24 and 48 h). It was observed that the material with deep cryogenic treatment had a Vickers microhardness profile and wear coefficient similar to the sample as received. The nitrided samples showed a higher (21.8%, 23.2% and 29%) microhardness value at the surface region than the sample as received and an improvement in wear coefficient in the transient (29.85%, 28.53% and 29.81%) and permanent (19.18%, 25.19% and 28.09%) regions.
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Wear resistance of the pressure armor submitted to deep cryogenic treatment and plasma nitriding
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10.1007/s40430-018-1387-y
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2018-09-01
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Magnetite nanoparticles 2–20 nm in size, forming agglomerates up to 70 nm in size, are obtained by cryochemical synthesis.
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Cryochemical Synthesis of Magnetite Nanoparticles
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10.3103/S0027131418050103
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2018-09-01
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During machining of difficult-to-cut alloys, the rapid tool wear as a consequence of the high values of cutting forces and temperatures significantly affects the surface integrity of the machined surfaces reducing the product in-service performances. The use of conventional cutting fluids limits the tool deterioration, but provides several environmental issues to deal with, such as the exhausted fluid disposal, cleaning of the parts after machining, health hazards for the machines operators. In recent years, several researches have proposed to use environmental-friendly cryogenic coolants, whose very low operating temperatures have demonstrated to be able to inhibit the thermally activated tool wear mechanisms leaving the machined surface almost free from pollutants. In this framework, the aim of this research work is to analyze the surface integrity of the machined surfaces produced in semi-finishing turning of the Ti6Al4V titanium alloy under different low-temperature cooling techniques, namely liquid nitrogen (LN_2), carbon dioxide (CO_2) and gaseous nitrogen (N_2) cooled at different temperatures, using the dry and wet cutting conditions as baseline. The surface integrity was evaluated considering both the surface finish (surface defects, roughness and topography) and the surface microstructural and mechanical alterations (altered layer, nano-hardness and residual stresses). The results showed that the best performances were obtained using N_2 cooled at − 150 °C, which determined both the absence of surface defects, as wrinkles or feed marks irregularities typical of the surface generated under LN_2, and high compressive residual stresses that made the surface suitable for biomedical and aerospace applications.
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Surface Integrity Analysis of Ti6Al4V After Semi-finishing Turning Under Different Low-Temperature Cooling Strategies
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10.1007/s11665-018-3598-x
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2018-09-01
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The present research paper focuses on optimisation of wear test parameters for different deep cryogenic treated AISI M2 tool steel material. Commercially available, AISI M2 tool steel material is machined as per ASTM G99-05 standards and was subjected to deep cryogenic treatment for the different holding time of 12, 24 and 36 h, followed by tempering for 2 h at $$150\,^{\circ }\hbox {C}$$ 150 ∘ C . The specimens were tested for their wear resistance using a pin-on-disc wear testing setup adopting Taguchi‘s design of experiments approach. The control variables selected were deep cryogenic treatment holding time, the speed of the rotating disc and load applied to the specimen pin. The wear test was conducted as per trials generated by Taguchi‘s $$\hbox {L}_{27}$$ L 27 orthogonal array, and the results are analysed using signal-to-noise ratio and analysis of variance. The results show that the cryogenic holding time has majorly affected the wear resistance followed by the load on the pin and disc speed. It is also observed that 24 h holding time for deep cryogenic treatment yields better wear resistance compared to 12 and 36 h. Microstructure and X-ray diffraction analysis of the cryogenically treated specimens reveals the conversion of retained austenite into martensite and the formation of fine carbides in the martensite lattice after deep cryogenic treatment process which are responsible for the increase in wear resistance. Also, the worn surface analysis shows that the adhesion wear, oxidation wear and abrasion wear are the predominant wear mechanisms observed under different testing conditions.
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Deep Cryogenic Treatment of AISI M2 Tool Steel and Optimisation of Its Wear Characteristics Using Taguchi‘s Approach
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10.1007/s13369-018-3242-y
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2018-09-01
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Methods of X-ray structural analysis and durometry, as well as electron microscopy were used to identify the stages of mechanical alloying in the case of torsion under high quasi-hydrostatic pressure on Bridgman anvils in the Cu–Zn and Au–Co systems that have different mutual solubility and enthalpy of mixing. It was established that decrease in temperature of mechanical alloying from room temperature (cold deformation) to the boiling temperature of liquid nitrogen (80 К, low-temperature deformation) has a considerable impact on mechanical alloying at different processing stages and on characteristics of an alloy synthesized by deformation. In the Cu–Zn system, when the ratio of powder components corresponds to the solid solution of α-brass in equilibrium state, as deformation increased, one observed consecutive change of evolution stages of the powder mix to the state of copper-based solid solution. At the same time, when processing temperature decreases, larger deformation is required to achieve analogous structural changes. In the Au–Co system characterized by absence of solubility at room and lower temperatures, one also observes the stages of powder mix evolution with the increase in deformation. However, complete dissolution occurs in the case of processing at 80 К, while larger deformation is required in the case of increase in mechanical alloying temperature. The paper examines possible mechanisms of solid solution formation in the system of components that are mutually insoluble under equilibrium conditions.
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Stages of Mechanical Alloying in Systems with Different Solubility Cu–Zn and Au–Co in the Case of Cold and Low-Temperature Deformation by Torsion Under Pressure
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10.1007/s11182-018-1481-8
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2018-09-01
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The two-equation model in porous media can describe the local thermal non-equilibrium (LTNE) effects between fluid and solid at REV scale, with the temperature differences in a solid particle neglected. A multi-scale model has been proposed in this study. In the model, the temperature differences in a solid particle are considered by the coupling of the fluid energy equation at REV scale with the heat conduction equation of a solid particle at pore scale. The experiments were conducted to verify the model and numerical strategy. The multi-scale model is more suitable than the two-equation model to predict the LTNE effects in porous media with small thermal conductivity. The effects of particle diameter, mass flow rate, and solid material on the LTNE effects have been investigated numerically when cryogenic nitrogen flows through the porous bed with small thermal conductivity. The results indicate that the temperature difference between solid center and fluid has the same trend at different particle diameters and mass flow rates, while the time to reach the local thermal equilibrium is affected by solid diameter dramatically. The results also show that the temperature difference between solid center and surface is much greater than that between solid surface and fluid. The values of $$ \rho {\text{c}} $$ ρ c for different materials have important influence on the time to reach the local thermal equilibrium between solid and fluid.
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Modeling and Simulation of Local Thermal Non-equilibrium Effects in Porous Media with Small Thermal Conductivity
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10.1007/s11242-018-1084-4
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2018-09-01
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To solve the failure problem of hot stamping tool, the CR7V steel was deep cryogenically treated at different dwelling times with multiple tempering. The hardness, impact toughness and wear resistance of the CR7V steel were examined, and the effects of deep cryogenic treatment on the microstructure of the CR7V steel were studied by means of optical microscope, scanning electron microscope and energy-dispersive spectroscopy. The results show that deep cryogenic treatment has little effect on the hardness of the tempered CR7V steel, but improves its impact toughness and wear resistance. The improvement in mechanical properties is a result of the combination of dissolution of large carbide particles, formation of small-sized and uniformly distributed carbide particles and fine tempered martensite structure. The cryogenic treatment is optimized as follows: vacuum gas quenching, deep cryogenic treatment at − 196 °C for 6 h and triple tempering at 560 °C for 2 h, which improves the wear resistance by 68% and the impact toughness by 58% compared to the conventional heat treatment.
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Effect of Deep Cryogenic Treatment on Mechanical Properties and Microstructure of the Tool Steel CR7V for Hot Stamping
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10.1007/s11665-018-3552-y
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2018-09-01
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The article aims to investigate the influence of cryogenic and ambient grinding on powder quality of king chilli ( Capsicum chinense L.). The grinding experiments were performed using a laboratory scale ball mill. Quality of the powders was accessed by measuring the properties such as densities, Hausner ratio, compressibility index, particle size distribution, colour change, microstructural changes, and mineral compositions. Bulk density (483 kg m^−3) and tapped density (556 kg m^‒3) of ambient ground powder was relatively higher than that of cryo-ground powder, (bulk density 414 kg m^‒3 and tapped density 480 kg m^‒3). However, Hausner ratio and compressibility index of ambient ground chilli powder were significantly lower than that of cryo-ground powder. The surface morphology, shape, and size of particles of cryo-ground powder were comparatively smoother, regular and smaller in size. Moreover, the major mineral (K) content and the colour (redness, yellowness, and lightness) were found to be relatively superior for cryo-ground powder. The overall results showed cryogenic grinding provides a better and finer quality ground powder than the conventional grinding methods. The results of this study will provide the spice industries, an opportunity to select the better grinding method based on the flow and sensory quality of the powder. The powder properties may further be utilized in the process modelling and design of packaging, grinding and handling equipment.
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Effect of grinding methods on powder quality of king chilli
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10.1007/s11694-018-9784-6
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2018-09-01
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The influence of Nb content on the microstructure and cryogenic mechanical properties of a 7%Ni steel was investigated within the Nb content range from 0 to 0.05%. The microstructure was characterized by optical microscope, scanning electron microscope, transmission electron microscopy and X-ray diffraction, and the low-temperature mechanical property tests were conducted. The Nb addition can effectively refine the prior austenite grains and microstructure of the steel. Fine niobium precipitates with a diameter of about 10–50 nm were observed. They tend to be spherical and locate mainly in the vicinity of grain boundaries. Although there are considerable amounts of reversed austenite forming at grain boundaries in the specimen containing the highest Nb content, no Nb element was detected in such reversed austenite, which implies that Nb element did not affect the formation of the reversed austenite directly. Mechanical test results suggest that the strength of the 7%Ni steel is not simply in relation to the prior austenite grain size, but also depends on the amount of reversed austenite. On the other hand, the grain refinement, enhanced with increasing Nb content, has a good effect on cryogenic toughness.
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Influence of Nb Content on Microstructure and Mechanical Properties of a 7%Ni Steel
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10.1007/s40195-018-0743-3
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2018-09-01
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In this work, an attempt has been made to optimize the process parameters of turning operation for INCOLOY 800H, with the help of cryogenically treated multilayer CVD-coated tool. The influencing factors like cutting speed, feed rate and depth of cut were selected as input machining parameters. The output responses such as surface roughness, microhardness, the degree of work hardening and material removal rate were considered in this work. The experimentation was planned and conducted based on Taguchi $$\hbox {L}_{27}$$ L 27 orthogonal array with three factors and three levels. Technique for order preference by similarity to ideal solution (TOPSIS) is a multi-criteria decision making tool has been used to optimize the turning parameters. Analysis of Variance is employed to identify the significance of the process parameters on the responses. Tool wear analysis also has been studied. This experimental research had proved that machining performance could be improved efficiently by the support of projected approach.
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Optimization of Turning Parameters of Machining Incoloy 800H Superalloy Using Cryogenically Treated Multilayer CVD-Coated Tool
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10.1007/s13369-018-3287-y
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2018-09-01
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Aerospace metal honeycomb materials with low stiffness had often the deformation, burr, collapse, and other defects in the mechanical processing. They were attributed to poor fixation method and inapposite cutting force. This paper presented the improvement of fixation way. The hexagonal aluminum honeycomb core material was treated by ice fixation, and the NC milling machine was used for a series of cryogenic machining. Considering the similar structure of fiber-reinforced composite materials, the milling force prediction model of ice fixation aluminum honeycomb was established, considering tool geometry parameters and cutting parameters. Meanwhile, the influence rule on milling force was deduced. The results show that compared with the conventional fixation milling method, the honeycomb processing effect is improved greatly. The machining parameters affect order on milling forces: the cutting depth is the most important, followed by the cutting width, then the spindle speed and the feed. Moreover, too small cutting depth ( a _p = 0.5 mm) will cause insufficient cutting force, while a _p > 2 mm with higher force will reduce the processing quality of honeycomb. Simultaneously, the honeycomb orientation ( θ ) has a great influence on processing quality. Using the model, the predicted and measured error values of the feed and main cutting force are all small in θ < 90°. But, the rate is 33 and 26% for the main cutting force and feed force error in θ > 90°, respectively, while they all exhibit the smallest error in θ = 60°. This bigger error mainly is due to unstable cutting force with obtuse angle. In addition, the tool rake angle has little influence on cutting quality in θ < 90°, but bigger on that in θ > 90°. Furthermore, the calculation model successfully conforms to the main deformation mechanism and influences parameters of the cutting force in the milling process, and it can accurately predict the cutting force in θ < 90° and guide the milling process.
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Investigate on milling force of cryogenic cooling processing aluminum honeycomb treated by ice fixation
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10.1007/s00170-018-2301-6
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2018-08-01
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The effects of cryogenic minimum quantity lubrication (CMQL) on cutting forces and cutting temperature are analyzed in high speed milling of 300M steel. The influences of cutting parameters on cutting forces and cutting temperature are predicted by analogue simulation. Based on single-factor comparative test, the variation laws of cutting forces F and cutting temperature T with cutting parameters are studied in high speed milling of 300M steel under dry and CMQL conditions. Under the condition of CMQL, the influence of cutting parameters (cutting speed v, feed per tooth f_z, cutting depth a_p and cutting width a_e) on cutting forces and the cutting temperature are analyzed by orthogonal test, and the prediction models of cutting forces and cutting temperature are established. The results show that CMQL condition can effectively reduce cutting forces and cutting temperature in the cutting process. Under the condition of CMQL, the cutting depth on the cutting forces is most significant, and the cutting speed has the greatest influence on the cutting temperature. The prediction model of cutting forces and cutting temperature is established, which can be a valuable reference for actual machining.
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Simulation and Experiments on Cutting Forces and Cutting Temperature in High Speed Milling of 300M Steel under CMQL and Dry Conditions
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10.1007/s12541-018-0147-3
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2018-08-01
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The increasing application of GPa-grade steel to autobody panels has led to increasing problems related to abrasive wear in mold and tool surfaces, which dramatically degrades tool life and also degrades the surface finish of the final product. This paper mainly concerns the punching wear resistance imparted by cryogenic (CR) and quenching and tempering (QT) treatments, as well as the additional use of a TiN coating layer. This is investigated using pin-on-disk tests and punching experiments against DP980 sheets for up to 90,000 cycles. The wear coefficient of CR is about 10% greater than that of QT, which leads to a decelerated punching pin wear rate relative to QT starting at around the 70,000th cycle. To numerically predict abrasive wear, we newly propose that the wear coefficients of the substrate should be updated as a function of the clearance stage to improve the accuracy and efficiency of the wear analysis.
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Abrasive Wear in Punching Pin with Cryogenic Treatment for GPa-Grade Steels
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10.1007/s12541-018-0139-3
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2018-08-01
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Conventional twist drilling is a widely used machining process for creating holes in aerospace and automobile structures. Drilling at room temperature can sometime affect the quality of machined holes due to increased thermal effects on the workpiece. Thermal effects can be a cumbersome when machining composites and fiber metal laminates due to their different thermal expansion coefficients, which may introduce additional stress in the structure. Thermal machining effects can be minimized using coolants supplied either directly or indirectly to the cutting tool-workpiece interaction zone, to remove away part of the generated heat. The use of coolants adds extra costs for handling, disposal, and environmental impact. Therefore, environmentally friendly cooling technologies are replacing conventional cooling methods to reduce costs and impact on the environment. In addition, the selection of machining parameters has great influence on the hole quality. This paper investigates the impact of drilling parameters and two modern cooling technologies namely cryogenic liquid nitrogen and minimum quantity lubrication on the hole perpendicularity error of fiber metal laminates commercially known as GLARE® (Glass Laminate Aluminum Reinforced Epoxy). It was also found that applying cryogenic liquid nitrogen or minimum quantity lubrication does not lead to an improvement in hole perpendicularity error in GLARE® laminates.
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The effect of drilling parameters, cooling technology, and fiber orientation on hole perpendicularity error in fiber metal laminates
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10.1007/s00170-018-2241-1
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2018-07-01
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The effect of Mn content on the microstructure and cryogenic mechanical properties of a 7% Ni steel was investigated within the Mn content range from 0.13% to 0.36%. The microstructure of the steel as determined by optical microscopy, scanning electron microscopy, transmission electron microscopy, electron backscattering diffraction and X-ray diffraction was presented, and the low-temperature mechanical properties were given. The size of prior austenite grain did not change a lot as Mn content increased. Film-like reversed austenite, having high stability, was found mainly in the specimens with lower Mn content; however, in the specimen with the highest Mn content, the role of Mn was not obvious in stabilizing reversed austenite. Besides, with increasing Mn content, the amount of reversed austenite at grain boundaries gradually decreased. The variable Mn content had a significant effect on cryogenic toughness, but not apparent on cryogenic tensile strength or yield strength. An excellent combination of cryogenic tensile and impact properties was obtained when Mn content of steel was 0.13%.
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Effect of Mn Content on Microstructure and Cryogenic Mechanical Properties of a 7% Ni Steel
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10.1007/s40195-018-0700-1
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