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2017-04-01
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The present study includes three parts—design and development of rotary liquid nitrogen applicator, investigation of machining performance under cryogenic application by using the developed applicator, and lastly comparison of the performances with dry and flood cutting. The surface milling of hardened EN 24 steel was performed at different speed-feed combinations corresponding to full factorial design plan (48 exp. runs). The effects of cutting speed, feed rate, and cutting conditions were investigated in respect of surface roughness, cutting force, and tool flank wear. The results of this study revealed the supremacy of cryogenic cooling in respect of all investigated quality characteristics. Lack of cooling and lubrication in dry cutting, and inadequate cooling and lubrication of flood cutting resulted in worse performance. On contrary, the double action cooling effect of cryogenic produces a superior performance, when passes through internal channel, firstly—due to an increased heat transfer rate caused by the primary and secondary flow within cutter, and secondly—because of the creation of a swirl flow at the outlet of the channel but within work surface.
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Effects of internal cooling by cryogenic on the machinability of hardened steel
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10.1007/s00170-016-9373-y
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2017-04-01
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It has been found that the total productivity of bacteria and micromycetes in the 0- to 50-cm layer of homogeneous cryozems (Cryosols) on slopes of northern and southern exposures varies from 1.2 to 1.4 t/ha, respectively, and the calculated content of microbial carbon varies in the range 0.7–0.9 t/ha. The respiratory activity of the upper soil layer is 2.5–2.6 μg C–CO_2/(g h); the potential methane formation capacity reaches 0.13 nmol CH_4/(m^2 day) for soils on slopes of northern exposure and 0.16 nmol CH_4/(m^2 day) for slopes of southern exposure. Accumulation of sorbed ammonium is recorded in the range 15–17 mg NH_4/100 g soil in summer. The increase of temperature in the upper horizons of soils on slopes of southern exposure by 5°C compared to the northern slopes results in only an insignificant increase in the emission of CO_2 and CH_4. The accumulation of sorbed ammonium and nitrate nitrogen in homogeneous cryozems during the vegetation period is comparable to that in gray forest soils of the southern taiga subzone of the Middle Siberia.
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Microbiological transformation of carbon and nitrogen compounds in forest soils of Central Evenkia
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10.1134/S1064229317040123
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2017-03-01
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A list of substances that can be used as low-temperature refrigerants for cryogranulation in cryochemical technology is provided. The substances are analyzed according to a criterion that considers the thermodynamic and transport properties of refrigerants. Data from a performance evaluation of various refrigerants are presented. For example, butane has properties that allow high efficiency to be achieved when it is used as a refrigerant but it is a flammable and explosive material, which limits its use.
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Selection of Coolant for Low-Temperature Refrigerators
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10.1007/s10556-017-0282-1
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2017-03-01
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In the last many decades, the usage of cutting fluid is a common technique for improving the machinability of metals. The application of cutting fluid during the machining phase significantly influences the environmental burden of the process. The disposal of these cutting fluids imposes threat to the environment due to their high noxiousness and non-biodegradable. Several researchers in the metal cutting sector have focused their work to improve the economic and ecological conditions of the machining process by reducing the consumption of the cutting fluids. There is a need to explore different green and innovative techniques to facilitate cooling and lubrication during the machining phase. The conventional cutting fluids not only have environmental and health restrictions, but also they are costly due to the strict regulations for disposal. In this paper, sustainable nature of different cutting fluids has been investigated. The paper also provides a detailed review of the cooling strategies with respect to their environmental impact on human’s health and developments in eradicating the usage of conventional cutting fluids has also been reviewed. Furthermore, different environment friendly cooling strategies, mainly minimum quantity of lubrication (MQL), and cryogenic arrangement have been reviewed in the literature, and it is found that there is a giant scope of further research work to optimize these cooling strategies in order to make them functionally applicable.
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Potential of alternative lubrication strategies for metal cutting processes: a review
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10.1007/s00170-016-9298-5
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2017-03-01
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It has been widely demonstrated that addition of Ni in low-carbon steels can effectively improve the cryogenic toughness, but the mechanism behind it has yet to be clarified. In the present work, the evolutions of microstructure and mechanical properties after quenching and tempering for Ni-containing cryogenic steels with different Ni contents (3.5–9 wt%) were investigated. The results showed that after quenching and tempering, the Ni-containing cryogenic steels were composed of tempered martensite and reversed austenite. The volume fraction of reversed austenite has increased from 0 up to 6.3% when the Ni content increases from 3.5% to 9%. The Charpy impact tests indicated that the low-temperature toughness was markedly improved with the increase in Ni content, which can be correlated with the increase in reversed austenite amount. The main contribution of reversed austenite to the toughness lies in: (1) the elimination of cementite precipitates improved the plastic deformation capacity of matrix, and (2) the crack propagation is hindered through plastic deformation.
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Correlations of Ni Contents, Formation of Reversed Austenite and Toughness for Ni-Containing Cryogenic Steels
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10.1007/s40195-016-0496-9
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2017-03-01
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Using full factorial design in experiment 3^2, the contents of vanadium and chromium in heattreated V–Cr–Mn–Ni cast irons with spheroidal vanadium carbide have been optimized with regard to the conditions of quartz sand erosion. It has been found that, in the case of bulk quenching from 760°C (or in combination with a subsequent plasma surface hardening), the maximum wear resistance of cast iron is achieved at 5.0% V and 2.0–4.5% Cr and, in the case of bulk quenching from 840°C followed by cryogenic treatment (–196°C), at 5.0% V and 7.0–9.0% Cr. It has been shown that the wear mechanism of the investigated alloys consists of the repeated deformation (indentation) of the matrix accompanied with spalling of spheroidal carbides and with chipping of eutectic carbides. Spheroidal vanadium carbides provide an effective protection of dendrites regions against erosion due to their uniform distribution in the bulk of the alloys.
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Wear mechanism and chemical composition optimization of complex-alloyed cast iron with spheroidal vanadium carbide under conditions of abrasive erosion
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10.3103/S106836661702009X
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2017-02-01
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This paper considers regularities governing the formation of automorphic tundra soils on glacial loamy deposits containing relict organic matter mainly represented by very fine plant detritus. Drainage, microtopography, and cryoturbation activity are the major controls of the development of these soils. With an increase in drainage, the following pedogenetic trend is observed on the surface of yedoma (Ice Сomplex) areas: gleyzem–cryozem–cryometamorphic soil. The climate change in the Holocene induced quick transformation of topography and general landscape situation and promoted formation and development of cryogenic soil complexes in the considered territory. Upon the low intensity of pedogenesis, the features and properties of previous soil formation stages are often preserved in the soil profiles; these are: gleyzation, peat accumulation, and cryoturbation.
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Soils of loamy watersheds of coastal tundra in the north of Yakutia: Pedogenetic conditions and processes
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10.1134/S1064229317020041
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2017-02-01
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A physical model of an induction electric heater for cryogenic control devices has been proposed. The chosen method of research has been justified. The scheme of the model, the structure of the measuring equipment, and a research technique that determines the energy characteristics of the induction heater have been considered, and recommendations on its design have been made. It is shown that it is advisable to use a three-leg laminated core with the winding located in the middle core as a basic element. Such a structure of the induction heater allows one to carry out research varying the material and shapes of the heated object. A microprocessor measuring complex that allows one to control and record up to six electric signals with an error no higher than 2% has been proposed.
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A physical model of an induction electric heater for cryogenic control devices
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10.3103/S1068371217020079
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2017-02-01
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Light is one of the most important factors affecting growth and morphogenesis of plants. Light intensity, photoperiod and spectral composition greatly affect morphogenetic responses of in vitro plants. Modification of light spectra during recovery after cryopreservation improves survival and regeneration, but the effect of modified light conditions prior to cryopreservation are not known. Therefore, the aim of the present study was to follow the photomorphogenetic response of potato plants ( Solanum tuberosum L.) under different light qualities i.e. cool white fluorescent (CW) used as control, warm white (HQI), white LEDs (W), blue LEDs (B), red LEDs (R) and a combination of red with 10 % of blue LEDs (RB) prior to cryopreservation, affecting recovery of cultivars Agrie Dzeltenie, Bintje, Maret, Anti and Désirée in vitro. Light spectral quality had a significant effect on growth characteristics of potato plants in vitro. Red light (R) promoted elongation growth but biomass accumulation remained low under monochromatic light treatments. Some of the pre-cryopreservation light treatments significantly affected post-cryopreservation success. Under blue LEDs, high early recovery was observed for all cultivars tested, whereas under red (R) or (HQI), lowest survival percentages were obtained 2–4 weeks after thawing. Specifically, during early recovery, blue light increased survival from 26 to 66 %, 4 to 31 % and 16 to 48 % for cultivars Agrie Dzeltenie, Anti, and Désirée, compared to illumination by red LEDs. Therefore, light spectral quality prior to cryopreservation can significantly affect the cryopreservation success of potato shoot tips.
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Modified light spectral conditions prior to cryopreservation alter growth characteristics and cryopreservation success of potato (Solanum tuberosum L.) shoot tips in vitro
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10.1007/s11240-016-1119-x
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2017-02-01
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In this study, mechanical properties and deformation mechanisms of Mg-Gd-Y-Zr alloy at temperatures ranging from 77 K to 523 K have been investigated. The effects of temperature on the mechanical properties, deformation mechanism, and fracture mechanism are discussed. The results show that the strengths of alloy decrease gradually while the elongations increase progressively with increasing temperature. The maximum ultimate tensile strength of the alloy as high as 442 MPa is obtained at 77 K. As the temperature increases from 77 K to 523 K, the ultimate tensile strength of the alloy decreases from 442 MPa to 254 MPa and the elongations increase from 6.3% to 28.9% gradually. The study verifies that the deformation at 77 K is predominated by basal slip and $${{\left\{ {10\bar{1}2} \right\}} \mathord{\left/ {\vphantom {{\left\{ {10\bar{1}2} \right\}} {\left\langle {10\bar{1}1} \right\rangle }}} \right. \kern-0pt} {\left\langle {10\bar{1}1} \right\rangle }}$$ 10 1 ¯ 2 10 1 ¯ 1 deformation twinning system. At 223 K, lots of twins emerge primarily at grain boundaries. At 373 K, all dislocations are proved to be 〈 a 〉 dislocations. At 523 K, although basal slip is still the dominant deformation mechanism, non-basal slip systems also become activate.
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Mechanical Properties and Deformation Mechanisms of Mg-Gd-Y-Zr Alloy at Cryogenic and Elevated Temperatures
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10.1007/s11665-016-2483-8
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2017-02-01
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In the surface layer of Ti-6Al-4V titanium alloy bar produced by cryogenic burnishing, reduced surface roughness, refined grain structure, and an obviously improved corrosion resistance are achieved. The surface roughness of cryogenic burnished sample was much lower than that of dry burnished sample. A nanocrystalline layer was fabricated on Ti-6Al-4V titanium alloy by cryogenic burnishing. There was a significant impact of the number of passes on structural refinement. The corrosion behavior of samples before and after cryogenic burnishing in a 0.9 % NaCl solution was investigated by potentiodynamic polarization curves, electrochemical impedance spectroscopy (EIS), and Mott–Schottky measurements. Ti-6Al-4V alloy with nanocrystalline layer has better corrosion resistance than the unburnished coarse-grained counterpart. The positive effect can be explained by the more rapid, stable, and less defective passive film formed on the surface nanocrystalline layer of Ti-6Al-4V alloy due to its high density of grain boundaries and dislocations.
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Enhancing the surface integrity and corrosion resistance of Ti-6Al-4V titanium alloy through cryogenic burnishing
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10.1007/s00170-016-9000-y
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2017-01-01
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In the present paper, an overview on the developments and applications of Ni-containing cryogenic steels is described with regard to the manufacturing processes. The relationship among Ni content, processing parameters and formation of reversed austenite has been worked out, which demonstrated that content and size of reversed austenite in Ni-containing steels can play important roles in improving their toughness. Based on extra-dephosphorization and desulphurization, new processing technologies have been developed. Controlled rolling in the aim of microstructure refinement and ultra-fast cooling (UFC) after hot rolling as on-line direct quenching has been successfully applied. Combining with inter-critical quenching and tempering after UFC-TMCP, the reversed austenite content was increased from 1.8 to 6.5%, leading to significant improvement of toughness. Several China’s steel works such as NISCO and Angang are capable of manufacturing high quality plates of Ni-containing steels, which are finding wide applications to building extra-large tanks for liquefied gases.
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Development and Applications of New Generation Ni-Containing Cryogenic Steels in PR China
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10.1007/978-3-319-52333-0_37
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2017-01-01
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Study area in continuous permafrost zone, characterized by tabular ground ice distribution, is known for active slope processes. In 90-s main attention was paid to translational landslides (active layer detachments). Due to climate trends summer temperature became warmer, active layer depth increased. As a result, active-layer base ice thawed and stopped development of translational landslides. At the same time, tabular ground ice table got involved into seasonal thaw and triggered earth flows at the lake shores, the second known type of cryogenic landslides found previously mainly at the sea coasts. Earth flows are the main process in thermal denudation: a complex of processes responsible for formation of thermocirques. Thermocirques are semi-circle shaped depressions resulting from massive ground ice thaw and removal of detached material downslope. Monitoring of thermocirque activation and development allows analyzing climatic controls of thermal denudation, and rates of thermocirque enlargement. At present in the Yamal Peninsula tundra predominance of processes associated with tabular ground ice thaw (cryogenic earth flows) over the processes associated with the ice formation at the bottom of the active layer (cryogenic translational landslides) is observed. This is caused by deepening of the active layer and exposure of the massive ground ice (tabular ground ice or ice-wedges) within permafrost to first seasonal and then perennial thaw. Activation of thermal denudation which started on Yamal Peninsula in summer 2012, is associated with extremely warm spring and summer of this year, and the warmest July of 2013. By the end of the warm season thawing of the top of icy permafrost and tabular ground ice on some slopes resulted in cryogenic landsliding in the form of earth flows and further thermocirque development. Thermocirques may form on slopes of various aspects but develop faster on south-facing slopes.
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Activation of Cryogenic Earth Flows and Formation of Thermocirques on Central Yamal as a Result of Climate Fluctuations
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10.1007/978-3-319-53483-1_24
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2017-01-01
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The results of an investigation of the effect of bulk quenching from temperature in the range of 760–1050°C, cryogenic treatment (–196°C) and surface plasma hardening on the abrasive-erosion wear of frugally alloyed V–Cr–Mn–Ni cast irons with spheroidal vanadium carbides have been presented in this article. It has been found that cast irons containing 5.0–7.5% V, 4.5–9.0% Cr, and 5.5–5.7% (total) of Mn and Ni after heat treatment have a 2–3-fold advantage in wear resistance compared to the prototype high-vanadium cast iron (11.9% V, 12.9% Mn). The maximum wear resistance of cast irons studied is achieved by quenching at 760°C followed by plasma surface hardening, as well as quenching at 840°C, followed by cryogenic treatment. These treatments result in the formation of an optimum microstructure that consists of spheroidal vanadium carbides, eutectic carbides M_7C_3, and a martensite-austenite matrix reinforced by secondary carbides. The increase in quenching temperature leads to an increase in the amount of residual austenite and decrease in the erosive wear resistance of cast irons.
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Effect of bulk heat treatment and plasma surface hardening on the microstructure and erosion wear resistance of complex-alloyed cast irons with spheroidal vanadium carbides
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10.3103/S1068366617010056
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2017-01-01
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This chapter presents a discussion on effect(s) of properties on heat transfer. In general, an impact of a property(ies) on heat transfer depends primarily on the mode of heat transfer: (1) conduction (steady state or transient; special case, nuclear fuels), (2) convection (single phase, forced or natural; two phase, boiling or condensation; and special cases: cryogenic gases, fluids at critical and supercritical pressures, liquid metals, and nuclear-reactor coolants), and (3) radiation. In support of a general discussion on the importance of various properties for heat-transfer calculations, Sections 3, 4, 5, 6, 7, 8, and 9 of this chapter contain basic properties in the tabulated form and property profiles vs. temperature in the graphical form of selected metals, alloys, insulation materials (only table data), and nuclear fuels (Sect. 3); selected gases at atmospheric pressure (Sect. 4); selected cryogenic gases (Sect. 5); low- and medium-temperature fluids on a saturation line (Sect. 6); water at subcritical, critical, and supercritical pressures; carbon dioxide, R-134a, ethanol, and methanol at supercritical pressures (Sect. 7); selected liquid metals on a saturation line (Sect. 8); and current and Generation IV nuclear-reactor coolants (Sect. 9).
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Heat Transfer Media and Their Properties
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10.1007/978-3-319-32003-8_23-1
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2017-01-01
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This paper reports the status of research and development of a reusable rocket engine in Japan. In the case of an expendable engine, in system selection, much weight must be put on performance, whereas in the case of a reusable engine, in addition to satisfactory performance required by the mission, reusability must be considered. In the system study, total design management (TDM) was employed for the LOx/ethanol engine, and the relation between performance and reusability was quantitatively evaluated. In the research on key components, the combustion chamber, bearings, and seals for turbopumps were selected as key components. To extend the lifetime of the combustion chamber, lowering the wall temperature is important, and thermal barrier coating (TBC) or film cooling (FC) becomes necessary. Turbopumps with a port for installation of a fiberscope on the bearing’s inner ring and on the shaft seal’s nose for direct observation were developed, and the feasibility of 100 reuses was established. A demonstration engine of the reusable sounding rocket was manufactured, and more than 100 operation cycle tests were carried out to confirm the feasibility of 100 reuses. Durability was confirmed by lifetime audit testing.
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Overview of Research and Development Status of Reusable Rocket Engine
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10.1007/978-3-319-27748-6_38
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2017-01-01
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Cell and tissue responses to external stimuli are difficult to study in vivo. Traditional monolayer culture conditions allow for observation of cellular response to stimuli in vitro with a great degree of control and manipulation of experimental conditions; however, many studies have shown that cells exhibit different gene expression patterns, drug resistance, and mechanical stress responses in two-dimensional environments, than when cultured in three-dimensional (3D) culture environments or in vivo. Cell-cell and cell-matrix interactions determine many aspects of cellular behavior, including proliferation, metabolism, differentiation potential, and viability. Therefore, many biomimetic strategies exist for 3D cell culture for various applications. This chapter describes 3D culture methods for assessing tissue response to exogenous stimuli, specifically electroporation. These methods include spheroid culture, cell culture on electrospun scaffolds, and cell culture on decellularized human dermal matrices. Spheroid culture is generally recognized as a model system for tumor development and has been used extensively to study electroporation effects. Other 3D culture techniques include using electrospun scaffolds for various tissues such as oral mucosa and head and heck squamous carcinoma, and can be readily adapted to studying electroporation effects. Decellularized human dermis has been recently demonstrated as an excellent substrate for recapitulating human skin and used for electroporation applications.
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3D Culture Models to Assess Tissue Responses to Electroporation
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10.1007/978-3-319-32886-7_29
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2017-01-01
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Aquatic environments produce a range of volatile organic compounds (VOCs) that can transfer into the atmosphere and affect climate. Much of our understanding on the biogeochemistry of volatiles in seawater stems from research on the biogenic trace gas dimethyl sulfide (DMS). Here, we describe four protocols for the quantification of DMS and other VOCs in aqueous samples that utilise direct injection or cryogenic enrichment techniques before separation and quantification using gas chromatography with flame photometric detection (GC-FPD). With few adjustments, the protocols can be customised to quantify a range of other gases including hydrocarbons such as isoprene and ethene, or halocarbons such as methyl chloride or bromoform. The limit of quantification for DMS is 1.5 pmol and the protocols range in sensitivities for DMS from 0.2 to 20 μM (direct injection of 200 μL headspace), 50 to 250 nM (headspace purging of 1.92 mL gaseous phase), 0.5 to 350 nM ( in - vial purging of 3 mL aqueous phase), and the sub-nanomolar range for in - tube purging of sample volumes up to 200 mL. Two additional adaptations of the protocol include quantification of the biological DMS-precursor dimethylsulfoniopropionate (DMSP) and the DMS-oxidation product dimethyl sulfoxide (DMSO).
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Protocols for the Quantification of Dimethyl Sulfide (DMS) and Other Volatile Organic Compounds in Aquatic Environments
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10.1007/8623_2016_206
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2017-01-01
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In a fusion reactor, Hydrogen Hydrogen (H) always exists as an impurity of the fuel. A water detritiation and a blanket fuel system produce a large amount of hydrogen. The hydrogen gas must be released to the environment Environment without tritium (T). High purity deuterium (D) and T are required as fuel of fusion reactor. The fusion reactor thus needs an isotope separation Isotope separation system having a large separation factor Separation factor . A cryogenic distillation Cryogenic distillation method (column) has been developed for this purpose. In this chapter, the cryogenic distillation method (column) is described in detail. The separation basis and the structure of the column are first introduced. One of the most important subjects is to develop simulation method of the column and is described in detail. A set of experimental data of the columns are also described in detail. Some future R&D subjects are then described. Although the cryogenic distillation is the most promising for a fusion reactor, some other methods can be applicable for fusion-related facilities. From this viewpoint, other methods such as thermal diffusion Thermal diffusion are also briefly introduced.
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Isotope Separation System (ISS)
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10.1007/978-4-431-56460-7_11
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2017-01-01
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Nowadays, the need for not only technically but also environmentally efficient machining processes is increasing. In this context, the reduction of oil emulsion type coolants used during machining of aeronautical engine components supposes a great challenge. In this paper, a novel approach based on the design, optimization and validation of a nozzle adaptor combining cryogenic technology and minimum quantity lubrication systems is proposed. The proposed work also deals with the aim of obtaining a cost-effective process. Thus, CO_2 flow and velocity was optimized in this line. Theoretically-based analysis were performed and compared with computational fluid dynamics (CFD) simulations and with real experimental tests as well. Once optimizing these key factors, two nozzle adaptors were designed and simulated by CFD. Different geometries were tested looking for the most efficient design. Finally, to obtain a feasible industrial product, the developed nozzle was tested as a CryoMQL demonstrator comparing with other lubricoolant techniques during milling Inconel 718. Results show a successful balance between technical and environmental issues using this technology when milling aeronautical alloys.
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Nozzle design for combined use of MQL and cryogenic gas in machining
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10.1007/s40684-017-0012-3
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2017-01-01
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In-space propulsion begins where the launch vehicle upper stage leaves off, performing the functions of primary propulsion, reaction control, station keeping, precision pointing, and orbital maneuvering. The main engines used in space provide the primary propulsive force for orbit transfer, planetary trajectories, and extraplanetary landing and ascent. The reaction control and orbital maneuvering systems provide the propulsive force for orbit maintenance, position control, station keeping, and spacecraft attitude control. Advanced in-space propulsion technologies will enable much more effective exploration of our solar system and will permit mission designers to plan missions to “fly anytime, anywhere, and complete a host of science objectives at the destinations” with greater reliability and safety. With wide range of possible missions and candidate propulsion technologies, the question of which technologies are “best” for future missions is a difficult one. A portfolio of propulsion technologies should be developed to provide optimum solutions for a diverse set of missions and destinations. A large fraction of the rocket engines in use today are chemical rockets; that is, they obtain the energy needed to generate thrust by chemical reactions to create a hot gas that is expanded to produce thrust. A significant limitation of chemical propulsion is that it has a relatively low specific impulse (I_s or thrust per mass flow rate of propellant). A significant improvement (>30 %) in I_s can be obtained by using cryogenic propellants, such as liquid oxygen and liquid hydrogen, for example. Historically, these propellants have not been applied beyond upper stages.
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In-Space Chemical Propulsion System Roadmap
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10.1007/978-3-319-27748-6_26
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2017-01-01
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Two types of nickel-base alloy covered electrodes, ENiCrMo-6 and ENiCrFe-9, were investigated and compared among their deposited metal compositions, microstructures, strengths, and cryogenic impact values. They all exhibited dendritic microstructures which were composed of dendritic fcc nickel-base solid solution, interdendritic phases, and grain boundary carbides. The molybdenum in the deposited metals tended to migrate and aggregate toward the edges of the dendrite arms during solidification. The niobium preferred to form oxide and/or carbide and aggregate in the interdendritic regions. The grain boundaries were filled with the continuous carbides and oxides. The differences in the tensile mechanical properties of the deposited metals of the two types of electrodes were relatively minor. The impact values of ENiCrMo-6 at −196 °C were above 80 J; while that of ENiCrFe-9 were in the range of 54-66 J. The relatively high level of carbon and sulfur and more grain boundary precipitates should be responsible for the lower cryogenic impact value of the ENiCrFe-9 covered electrode.
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A Comparative Study of Microstructures and Properties of Two Types of Nickel-Base Alloy Covered Electrodes
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10.1007/s11665-016-2434-4
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2017-01-01
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The aim of this study has been the description of the current state of the art of frozen vegetables. One of the most promising food and beverage categories in the current market is represented by frozen products, although the modern food industry is officially born in 1928 in the United States of America. Before this date, previous freezing systems were based on the production of ice, with the use of refrigerating machines and the development of storage rooms. At present, the evolution of this sector can be briefly identified with the improvement of freezing techniques, the notable demand of food supplies worldwide, and the increasing number of frozen food typologies, including fruits and vegetables. Basically, frozen foods are very similar to original products when speaking of sensorial features. On the other side, some defects have been observed and correlated with freezing techniques and blanching treatments. The most used systems—air blast, plate and immersion freezers—are discussed with the description of correlated advantages and risks, including economic evaluations.
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Technology and Chemical Features of Frozen Vegetables
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10.1007/978-3-319-53932-4_2
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2017-01-01
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Prompted by methodological advances in measurements with X-ray free electron lasers, it was realized in the last two years that traditional (or conventional) methods for data collection from crystals of macromolecular specimens can be complemented by synchrotron measurements on microcrystals that would individually not suffice for a complete data set. Measuring, processing, and merging many partial data sets of this kind requires new techniques which have since been implemented at several third-generation synchrotron facilities, and are described here. Among these, we particularly focus on the possibility of in situ measurements combined with in meso crystal preparations and data analysis with the XDS package and auxiliary programs.
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Serial Synchrotron X-Ray Crystallography (SSX)
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10.1007/978-1-4939-7000-1_10
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2017-01-01
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This experimental study investigates the effects of sea water and thermal cycling conditions on strength of adhesive lap joints made for fiber metal laminate (FML) and 430 stainless steel adherends subjected to standard tensile impact loading condition. The FMLs (three and five layers) were fabricated using 430 stainless steel sheets and fiberglass prepreg layers. The joints are kept in the sea water taken for 30 days in the laboratory. Some of the specimens are then thermally cycled in an oven (5 and 10 cycles, 40/100 °C, dwell time 20 min) and also the others are kept in liquid N_2 (5 and 10 cycles, −40/−100 °C, dwell time 10 min), and afterwards tested. Experimental results shown that the absorbed energy by adhesive lap joint specimens that are subjected to sea water is reduced. The adhesive joint strength is improved at high thermal cycling, but decreased at cryogenic temperatures with respect to sea water without thermal cycling.
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Thermal Cycling and Environmental Effect on Tensile Impact Behavior of Adhesive Single Lap Joints for Fiber Metal Laminate
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10.1007/978-3-319-41766-0_14
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2017-01-01
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This chapter outlines a few of the topics of interest in the field of tribology of carbon fiber-reinforced polymer composites, especially for achieving low friction and low wear performance against metal counterparts under different environmental conditions. The overview presents a survey of the findings of present and past workers. Particular emphasis is focused on recent advances in developing a new class of engineering materials with a higher degree of multifunctionality by the simultaneous combination of carbon fibers and other fillers such as ceramic nanoparticles or carbon nanotubes. An attempt is made for the design of a desirable wear-resistant composite material for specified wear conditions by the use of artificial neural networks. Finally, a few remarks about high-friction composites as well as metal, glass, and ceramic matrix composites are made.
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Carbon Fibers in Tribo-composites
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10.1007/978-3-319-46120-5_30
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2017-01-01
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Titanium alloy is being widely used in various applications in aerospace, energy and biomedical industries mainly due to its superior material properties such as high strength even at high temperatures, lightweight and corrosion resistance. However, because of its extremely poor machinability, many enhancement techniques such as minimum quantity lubrication (MQL), cryogenic machining, laser assisted machining (LAM), etc., have been proposed to improve the machinability. This study specifically examined the machinabilities of MQL and cryogenic machining for Ti-6Al-4V and compared to those of dry and wet machining. Liquid nitrogen (LN2) was used for cryogenic machining with the specially designed cryogenic spraying systems. In addition to traditional MQL, a new MQL technique, with the lubricant mixed with a small amount (~0.1%) of exfoliated graphite nano-platelets (xGnPs), was tested to make the comparison against other techniques. The results obtained showed that both cryogenic and MQL machining showed improved performance in comparison to the dry and wet machining. For cryogenic machining, however, the exposure to LN2 causes the thermal gradient on the cutting tools and the hardening of the titanium alloy during the machining, which resulted in excessive tool wear and micro-fracture and increased the cutting forces.
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Milling of titanium alloy with cryogenic cooling and minimum quantity lubrication (MQL)
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10.1007/s12541-017-0001-z
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2017-01-01
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Tile-based DNA self-assembly is a promising method in DNA nanotechnology and has produced a wide range of nanostructures by using a small set of unique DNA strands. DNA star motif, as one of DNA tiles, has been employed to assemble varieties of symmetric one-, two-, three-dimensional (1, 2, 3D) DNA nanostructures. Herein, we describe the design principles, assembly methods, and characterization methods of 3D DNA nanostructures assembled from the DNA star motifs.
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Three-Dimensional DNA Nanostructures Assembled from DNA Star Motifs
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10.1007/978-1-4939-6454-3_2
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2017-01-01
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High-speed hydrodynamic processes and phase transitions of “explosive character” developing in a result of an impulse penetration of short cryogenic nitrogen jets in a water are researched. The experimental researches were carried out on the base of a special scheme of tiny cryogenic “dewar”. Dynamics of flow formation and of its structure arising in a result of cryogenic jet penetration as well as the influence of phase transitions were being recorded by high-speed digital video-camera. The internal surface of formed cavern turned out to be plated by layer of intense evaporating cryogenic nitrogen. One of the main problems arising at mathematical simulation of the processes accompanying physical explosions is their kinetics. Its physical model can be formulated on the results of experimental researches or to create, in particular, the state dynamics model of discrete structure of cryogenic drops cluster under ”instantaneous” contact with a water. The experimental results and possible mathematical models will be discussed.
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Penetration of Cryogenic Nitrogen Jets into a Liquid: “Phase Explosion” and Formation of Bubble Clusters
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10.1007/978-3-319-44866-4_88
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2017-01-01
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This chapter aims to introduce some of the specific bonding-related issues that face those responsible for bonding operations in space applications. We have to consider two cases: structures for launchers and structures for satellite where the environment in terms of load is different. In the case of launchers, extremely high mechanical loads over a short time occur, and for satellites, there is the gravity magnified by about 20, followed by exposure to extremely high temperatures over a very long period, with the observation and telecom satellites under zero gravity. To design for such broad specifications and to select materials, such as adhesives, it is just the first in a series of challenges. To perform tests on Earth reproducing space-like environments while subject to terrestrial gravity is the second and not the least significant. This chapter is intended to be an introduction to the issues which have to be considered together in the case of spatial bonding from the bottom, on Earth, upward, to space.
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Aerospace Industry
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10.1007/978-3-319-42087-5_45-2
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2016-12-05
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Background Establishing a stand-alone cryogenic test stand is of vital importance to ensure the highly reliable and available operation of superconducting radio-frequency module in a synchrotron light source. Operating a cryogenic test stand relies strongly on a capability to deliver two-phase helium along long cryogenic transfer lines. A newly constructed cryogenic test stand with flexible cryogenic transfer lines of length 220 m at National Synchrotron Radiation Research Center is required to support a superconducting radio-frequency module operated at 126.0 kPa with a 40-W dynamic load for a long-term reliability test over weeks. It is designed based on a simple analytical approach with the introduction of a so-called tolerance factor that serves to estimate the pressure drops in transferring a two-phase helium flow with a substantial transfer cryogenic heat load. Tolerance factor 1.5 is adopted based on safety factor 1.5 commonly applied in cryogenic designs to estimate the total mass flow rate of liquid helium demanded. A maximum 60-W dynamic load is verified with experiment measured with heater power 60 W instead after the cryogenic test stand has been installed. Results Aligning the modeled cryogenic accumulated static heat load with the results measured in situ, actual tolerance factor 1.287 is obtained. The feasibility and validity of our simple analytical approach with actual tolerance factor 1.287 have been scrutinized by using five test cases with varied operating conditions. Calculated results show the discrepancies of the pressure drops between the estimated and measured values for both liquid helium and cold gaseous helium transfer lines have an underestimate 0.11 kPa and an overestimate 0.09 kPa, respectively. A discrepancy is foreseen, but remains acceptable for engineering applications from a practical point of view. Conclusions The simple analytical approach with the introduction of a tolerance factor can provide not only insight into optimizing the choice of each lossy cryogenic piping element of the transfer lines in the design phase but also firm guidance for upgrading the present cryogenic transfer lines for its subsequent application.
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Pressure drop of two-phase helium along long cryogenic flexible transfer lines to support a superconducting RF operation at its cryogenic test stand
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10.1186/s40064-016-3717-9
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2016-12-01
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The results of a series of experiments using a piezovibration formation module for producing cryogenic targets with a given fuel layer structure are presented.
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On the cryogenic layer formation under conditions of high-frequency mechanical action
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10.3103/S1068335616120034
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2016-12-01
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It is well known that high Co-Ni steels exhibit excellent toughness. Since the good toughness in these steels is supposed to be related to thin layers of austenite between martensite crystals, this work presents an experimental study corroborated with diffusional calculations to characterize the evolution of reverted austenite. Atom probe measurements were conducted for analyzing the element distribution in austenite and martensite during tempering. These results were correlated with crystallographic information, which was obtained by using transmission electron microscopy investigations. Additionally, the experimental findings were compared with kinetic calculations with DICTRA™. The investigations reveal that reverted austenite formation during tempering is connected with a redistribution of Ni, Co, Cr, and Mo atoms. The austenite undergoes a Ni and Cr enrichment and a Co depletion, while in the neighboring martensite, a zone of Ni and Cr depletion and Co enrichment is formed. The changes in the chemical composition of austenite during tempering affect the stability of the austenite against phase transformation to martensite during plastic deformation and have thus decisive influence on the toughness of the material.
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Formation and Growth Kinetics of Reverted Austenite During Tempering of a High Co-Ni Steel
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10.1007/s11661-016-3760-8
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2016-12-01
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In inertial fusion energy research, considerable attention has recently been focused on low-cost fabrication of a large number of targets by developing a specialized layering module of repeatable operation. The targets must be free-standing, or unmounted. Therefore, the development of a target factory for inertial confinement fusion (ICF) is based on methods that can ensure a cost-effective target production with high repeatability. Minimization of the amount of tritium (i.e., minimization of time and space at all production stages) is a necessary condition as well. Additionally, the cryogenic hydrogen fuel inside the targets must have a structure (ultrafine layers—the grain size should be scaled back to the nanometer range) that supports the fuel layer survivability under target injection and transport through the reactor chamber. To meet the above requirements, significant progress has been made at the Lebedev Physical Institute (LPI) in the technology developed on the basis of rapid fuel layering inside moving free-standing targets (FST), also referred to as the FST layering method. Owing to the research carried out at LPI, unique experience has been gained in the development of the FST-layering module for target fabrication with an ultrafine fuel layer, including a reactor- scale target design. This experience can be used for the development of the next-generation FST-layering module for construction of a prototype of a target factory for power laser facilities and inertial fusion power plants.
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Cryogenic hydrogen fuel for controlled inertial confinement fusion (formation of reactor-scale cryogenic targets)
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10.1134/S1063778816070024
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2016-12-01
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For efficient discharge and storage of refrigerated chemicals such as ammonia, special processes must be developed, and several related parameters must be checked and evaluated. In this study, pressure changes in ammonia storage systems that are purged by nitrogen gas, during filling by gaseous ammonia, were calculated and an environment-friendly technique for discharging ammonia gas was developed. In addition, exergy analysis for the system was performed, and the nitrogen discharge rate in the system was calculated. The total exergy loss was determined to be 43.18 %, and the nitrogen discharge rate was determined to be 38,995 dm^3 h^−1 for the proposed system.
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Industrial-scale purging of ammonia by using nitrogen before environmental discharge
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10.1007/s40090-016-0096-6
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2016-12-01
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Cryogenic treatment is being extensively used in many industries for enhancing the properties of materials. Although the effect of cryogenic treatment on the properties of ferrous materials has been well documented, its effect on non-ferrous alloys has not been fully understood. In this study, the influence of extensive cryogenic treatment and mild cryogenic treatment on the properties of copper beryllium alloy has been investigated. Microstructure analysis was carried out using optical microscope and scanning electron microscope studies. Differential scanning calorimeter analysis was conducted to study the effect of cryogenic treatment on phase transformation of the samples. XRD analysis was performed to identify the possible phases. Several properties such as tensile strength, hardness, and electrical resistivity were measured. Microstructure analysis revealed that the grains of cryogenic treated sample are smaller than that of as-received samples and the dispersion of beryllide particles in the α-copper matrix after cryogenic treatment was found to be increased. Differential scanning calorimeter analysis indicated that there was a reduction in phase transformation duration due to cryogenic treatment. Tensile strength and hardness were improved by the cryogenic treatment. In addition, a decrease in the electrical resistivity was observed after cryogenic treatment.
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Effect of Cryogenic Treatment on Microstructure and Properties of CuBe2
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10.1007/s13632-016-0314-9
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2016-12-01
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This article describes results of the development, construction, and test of the first three-phase distribution power transformer prototype in Russia with windings made from second-generation HTSC wire and iron core from amorphous electrical steel. The design of its elements is described and improvement of HTSC transformer performance characteristics compared to conventional power transformers with the same power rating is shown.
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First 1 MVA and 10/0.4 kV HTSC transformer in Russia
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10.1134/S0040601516130085
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2016-11-23
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At cryogenic temperatures the electron–hole plasma in semiconductors becomes strongly degenerate, leading to very sharp internal layers, extreme depletion in intrinsic domains and strong nonlinear diffusion. As a result, the numerical simulation of the drift–diffusion system suffers from serious convergence issues using standard methods. We consider a one-dimensional p-i-n diode to illustrate these problems and present a simple temperature-embedding scheme to enable the numerical simulation at cryogenic temperatures. The method is suitable for forward-biased devices as they appear e.g. in optoelectronic applications. Moreover, the method can be applied to wide band gap semiconductors where similar numerical issues occur already at room temperature.
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Numerical simulation of carrier transport in semiconductor devices at cryogenic temperatures
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10.1007/s11082-016-0817-2
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2016-11-01
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Spectral systems with an MKhK-6 cryogenic, high-throughput, multipass gas cell for studying the absorption spectra of gaseous media with high spectral resolution in the 0.1–6 μm range at pressures of 100 to 5·10^6 Pa and temperatures of 180–300 K are discussed. Their use in measurements of spectral absorption coefficients, temperature dependences of the spectral transmission function, and parameters of spectral absorption lines is examined.
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Spectral Apparatus with a Cryogenic, High-Throughput, Multipass Gas Cell for Studies of Absorption of Radiation by Gaseous Media
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10.1007/s10812-016-0377-z
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2016-11-01
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The conditions of heat transfer intensification using short local heat pulses applied to a heater cooled by fluids with a boiling curve hysteresis (cryogenic, organic fluids, and others) are considered.
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Method for intensifying the heat transfer using local heat pulses
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10.3103/S1068335616110038
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2016-11-01
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The heat capacity, C _ p , of boron-doped single-crystal diamonds grown by the temperature gradient method was studied. The boron contents were < 10^16, ~ 10^18, and ~ 10^20 cm^–3. The heat capacity data for all tested crystals match well (within the measurement accuracy 1%) in the temperature range of 150–400 K and obey the Debye law. At low temperatures the heat capacity follows linear law possibly due to metallic inclusions in diamond bulk. Using this data the amount of metal can be calculated for each sample.
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Heat capacity of bulk boron-doped single-crystal HPHT diamonds in the temperature range from 2 to 400 K
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10.3103/S1063457616060058
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2016-11-01
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The problems of designing and employing cryogenic systems operating in transient modes over a considerable operating time as well as various methods of simulating transient operation of these systems are discussed. The advantages of application of dynamic simulation of cryogenic systems over classical methods of calculation of steady-state mode are shown. The available information on dynamic simulation of large helium cryogenic systems is reviewed. To validate the dynamic simulation method, the transient mode of operation of a large helium liquefier is analyzed applying universal software tool for dynamic simulation modeling of chemical systems, the results of which are compared with the experimental data.
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Problems and Development of Methods of Dynamic Simulation of Cryogenic Systems
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10.1007/s10556-016-0217-2
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2016-11-01
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This paper presents the results of experiments performed at the cold moderator test stand with beams 1, 4–6, and 9 for studying the possibility of loading the moderator chamber with frozen balls (pellets) 3.5 to 3.8 mm in diameter through the cryogenic pipeline of complex configuration with a 4-m-long section ascending at an angle of 50°. The optimum parameters for the successful loading of the moderator chamber are found to be the following: mass flow rate of the carrier gas (helium), 2 g/s; temperature of the pipeline walls and helium, 79–85 K; angular velocity of the disc in the ball dispenser, 3.6°/0.5 s; ball ejection rate from the dispenser to the pipeline, 8 balls/s; and maximum chamber loading time, 6 h. During the construction of the test stand, the cryostat is replaced with a new one with two gas blowers, which is necessary for maintaining a low temperature in two independent cooling circuits (for two cold moderators or for a cold moderator and the test stand) and the software for the control of the operation parameters is modified.
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Possibility of loading the chamber of the “central” pelletized cold moderator for IBR-2 reactor beams 1, 4–6, and 9
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10.1134/S1547477116060042
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2016-10-04
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This paper investigates the ultimate strength behaviours of the unbonded prestressed concrete (PC) beams at cryogenic temperatures that aims to promote the applications of PC structures in cryogenic environments. Nineteen unbonded PC beams with different tension control stresses (0.4, 0.6, 0.75 f _ptk) were tested at 20, −40, −70 and −100 °C. The structural performances of the unbonded prestressed reinforced concrete (RC) beams under cryogenic temperature were reported that included general load–deflection behaviours, ultimate resistances, and failure modes. The test results indicated that at cryogenic temperatures, the plane section assumption for the prestressed RC beams under bending still worked, and the appearance of cracks can still be delayed by prestressing. The resistances corresponding to crack initiation, the yield of the non-prestressed tensile reinforcements and the ultimate failure of the beams all increased linearly with the decrease of the temperature. The stiffness of specimens also increased as the temperature dropped. Analytical methods for predicting the resistance corresponding to the crack initiation and the ultimate resistance at low temperatures were developed and compared with the test results.
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Ultimate strength behavior of prestressed concrete beams at cryogenic temperatures
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10.1617/s11527-016-0956-8
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2016-10-01
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Cutting edge geometry and punch wear are closely associated. Punch wear increases past shape errors. These basic defects may be found on the surface of the part and characterise its quality and accuracy. Punch errors are largely associated with punch wear and process parameters. The aim of this study was to investigate the effect of cryogenically treated punches on stainless steel sheet blanking shape errors. For this purpose, the blanking was carried out in a punch machine using 7- and 9-mm-diameter AISI D3 cold work tool steel punches and 1.5-mm-thick AISI 304 austenitic stainless steel sheets. One punch group was subjected to the cryogenic process at −145 °C in addition to the conventional heat treatment. The cryogenic process was carried out to improve the wear resistance and product quality. For this study, punch weight losses were measured and punch wear was evaluated through analysis of SEM and OM images. The rollover depth, burnish depth, fracture depth, burr height and angle of fracture of the selected parts were measured in the specified number of blanks. Results showed that the cryogenic process increased the wear performance of the punches and reduced the shape errors of the parts.
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Punch structure, punch wear and cut profiles of AISI 304 stainless steel sheet blanks manufactured using cryogenically treated AISI D3 tool steel punches
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10.1007/s00170-016-8515-6
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2016-10-01
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The crack that mostly occurs at the heat-affected zone is a major challenge for welded magnesium alloys including AZ91D. This study proposed a new method of laser welding of this alloy assisted with a combination of cryogenic and heat treatment to remedy this problem. It was found that when the new process is used, the crack transformed from heat-affected zone to fusion zone and the tensile strength of the sample were 32.57 % higher than that welded by traditional laser welding. Through studying the changes of hardness, precipitates, and micro-structure in welded joint, it was found that the conversation of Mg17Al12 from dendritic state into short rod state as well as the appearance of dispersed Al8Mn5 particles played a major role in improving the mechanical properties of the welded magnesium alloy.
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The influence of cryogenic and heat treatment on the mechanical properties of laser-welded AZ91D
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10.1007/s00170-015-8332-3
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2016-09-24
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This study concentrates on the principles of heat transfer within cryogenic insulation systems, especially accounting for self-evacuating systems (deposition–evacuation of the filling gas). These principles allow the extrapolation to other temperatures, gases and other materials with the input of only a few experimentally derived or carefully estimated material properties. The type of gas (e.g. air or $$\hbox {CO}_{2}$$ CO 2 ) within the porous insulation material dominates the behaviour of the effective thermal conductivity during the cooldown of the cryogenic application. This is due to the specific temperature-dependent saturation gas pressure which determines the contribution of the gas conductivity. The selected material classes include powders, fibrous insulations, foams, aerogels and multilayer insulations in the temperature range of 20 K to 300 K. Novel within this study is an analytical function for the total and the mean thermal conductivity with respect to the temperature, type of gas, external pressure and material class of the insulation. Furthermore, the integral mean value of the thermal conductivity, the so-called mean thermal conductivity, is calculated for a mechanically evacuated insulation material and an insulation material evacuated by deposition–evacuation of the filling gas, respectively. This enables a comparison of the total thermal conductivity of cryogenic insulation materials and their applicability for a self-evacuating cryogenic insulation system.
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Study on the Principle Mechanisms of Heat Transfer for Cryogenic Insulations: Especially Accounting for the Temperature-Dependent Deposition–Evacuation of the Filling Gas (Self-Evacuating Systems)
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10.1007/s10765-016-2114-5
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2016-09-15
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The glass fiber reinforced epoxy resin composites play an important role in superconducting Tokamak, which are used to insulate the metal components, such as superconducting winding, cooling pipes, metal electrodes and so on. For the components made of metal and glass fiber reinforced epoxy resin composites, thermal shrinkage leads to non-ignorable thermal stress, therefore, much attention should be paid on the thermal shrinkage rate of glass fiber reinforced epoxy resin composites. The structural design of glass fiber reinforced epoxy resin composites should aim at reducing thermal stress. In this paper, the density, glass fiber content and thermal shrinkage rate of five insulation tubes were tested. The testing results will be applied in structural design and mechanical analysis of isolators for superconducting Tokamak.
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R&D on glass fiber reinforced epoxy resin composites for superconducting Tokamak
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10.1186/s40064-016-2995-6
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2016-09-01
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Effects of the normalizing treatment on microstructural evolution, mechanical properties, and impact fracture behavior of 20MnV low alloy cryogenic as-rolled steel were evaluated. The results indicate that grain boundary carbide and acicular ferrite of the as-rolled steel were eliminated and a large amount of nanoscale VC precipitates were observed after 860 °C normalizing treatment. The as-normalized steel had lower strength, higher elongation, and impact absorbed energy than as-rolled steel. The optimal comprehensive mechanical property, especially the superior cryogenic toughness with impact absorbed energy values at −20 and −50 °C were 62 and 40 J, respectively, was obtained at 860 °C. The as-rolled steel contained shearing crack and necking crack simultaneously, while 860 °C as-normalized steel only contained deflecting necking crack, indicating the significant improvement of the toughness.
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Microstructure Evaluation and Mechanical Properties of Low Alloy Cryogenic Steel Processed by Normalizing Treatment
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10.1007/s11665-016-2208-z
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2016-09-01
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The effect of deep cryogenic treatment (DCT) on microstructure and mechanical properties including corrosion behavior of the squeeze-cast AE42 alloy has been investigated. For comparison, the same has also been studied on the untreated alloy. Both the untreated and deep cryogenic-treated (DCTed) alloys comprised α-Mg and Al_4RE phases. Volume fraction of the Al_4RE phase in the AE42 alloy reduced gradually following DCT carried out from 4 to 16 h. Ductility and UTS increase significantly with a marginal increase in YS of all the DCTed alloys. The improvement was attributed to the dissolution of the brittle Al_4RE phase following DCT. Among the alloys employed, the best tensile properties were obtained for the 16-h DCT alloy due to its lowest content of the brittle Al_4RE phase. Creep resistance of the DCTed alloys was lower than that of the untreated alloy owing to the presence of less amount of thermally stable intermetallic Al_4RE phase. Wear resistance of the alloy reduces following DCT due to reduced hardness of the DCTed alloys. The untreated alloy exhibits the best corrosion resistance, whereas poor corrosion resistance of the DCTed alloys is attributed to the reduced amount of Al_4RE phase that fails to built a corrosion resistance barrier.
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Effect of Deep Cryogenic Treatment on Microstructure and Properties of AE42 Mg Alloy
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10.1007/s11665-016-2238-6
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2016-09-01
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A gas analytical technique with compact size, low cost, sufficient sensitivity, and excellent reproducibility is required in many fields including exhaled breath analysis for medical monitoring. In the present study, we examined selective acetone concentration by quench condensation at cryogenic temperature followed by temperature programmed desorption (cryogenic temperature programmed desorption (cryo-TPD)) for possible applications to breath analysis for medical monitoring. The essence of cryo-TPD is rough mass selection by thermal desorption followed by quantification of certain species using mass spectrometry. The performance of cryo-TPD was investigated in the acetone concentration range below 1 × 10^−6 volume fraction (1 ppmv). It was found that acetone is selectively quench-condensed on a tungsten substrate at 50 K without the major components of air, such as N_2 and O_2. The concentrated acetone gas was obtained by the following thermal desorption at around 151 K. Under conditions of condensation for 1 min and pressure of 1 × 10^−2 Pa, the lowest limit of detection reached well below 10 × 10^−9 volume fraction (10 ppbv). The relationship between the cetone intensity of cryo-TPD and the acetone concentration in the gas was almost linear in the ppbv range. The separation of acetone and propanal using the fragmentation pattern, which have almost the identical molecular mass, was also demonstrated in the present study.
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Selective Concentration of Ultra-trace Acetone in the Air by Cryogenic Temperature Programmed Desorption (cryo-TPD)
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10.2116/analsci.32.937
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2016-09-01
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The S-N fatigue behavior of newly developed Fe25Mn steel, including base metal and butt-welded joint, was investigated at 298 and 110 K, and the results were compared to those of previously reported Fe16Mn2Al and STS304L steels. Fe25Mn steel has quite promising fatigue performance at 298 K and even at 110 K, showing comparable resistance to fatigue to STS304L. The S-N fatigue behavior of Fe25Mn steel was dependent on tensile strength at 298 and 110 K, the trend of which well agreed to that of other austenitic steels. The electron backscatter diffraction and micrographic analyses suggested that transformation induced plasticity and twinning induced plasticity effects did not occur in Fe25Mn steel under fatigue loading at room and cryogenic temperatures. The butt-welded Fe25Mn/Fe25Mn and Fe25Mn/STS304L specimens also showed a satisfactory fatigue behavior which was even comparable to that of STS304L/STS304L specimen at 110 K. The S-N fatigue behavior of Fe25Mn steel and its welds was discussed based on the fractographic and microscopic observations.
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S-N fatigue behavior of Fe25Mn steel and its weld at 298 and 110 K
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10.1007/s12540-016-6108-4
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2016-09-01
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Pure carbon nanotube (CNT) yarns were spun from highly aligned multiwall CNT forests, and their thermal and cryogenic behaviour under cyclic heating–cooling treatment was studied using a Dynamic Mechanical Analyser over a temperature range from −100 to 200 °C. The effect of static tension force applied on the CNT yarn during the treatment was also examined. The study primarily focused on the dimensional changes of the CNT spun yarns in response to thermal and cryogenic treatment, but the changes in morphology and mechanical properties were also discussed. The results revealed a special thermal/cryogenic behaviour of the CNT spun yarns, and provided technical information and engineering data for the design and application of CNT spun yarns.
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Investigation on thermal and cryogenic behaviour of carbon nanotube spun yarns using a dynamic mechanical analyser
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10.1007/s10853-016-0100-8
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2016-08-01
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Meadow-chernozemic soils (Turbic Chernozems Molliglossic) in the western Trans-Baikal Region are dissected by large cryogenic cracks penetrating to the depth of 100–120 cm and filled with humified material. The depth of humus pockets is 50–80 cm, and their width in the upper part is 50–90 cm. The lower boundary of most of the humus pockets lies at the depth of 60–70 cm. The development of cryogenic cracks proceeded due to their penetration into the frozen ground, which is evidenced by their sharply narrowing lower part. The fraction of physical clay (<0.01 mm) constitutes a considerable part of the material filling the cracks, which explains the significant humus content in this material. The contents of humus and adsorbed bases sharply decrease down through the soil profile in the soil mass between the cracks and remain relatively stable in the material filling the cracks. The soil mass in humus pockets is less compact that that in the background soil mass at the same depth, which is explained by the higher humus content in the pockets. Humified soil material in the pockets is also characterized by a higher porosity and, hence, higher water permeability than the surrounding soil mass.
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Morphology and physical properties of soil material in cryogenic cracks of permafrost-affected meadow-chernozemic soils of the Trans-Baikal Region
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10.1134/S1064229316080159
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2016-08-01
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We present the design of MOCCA, a large-area particle detector that is developed for the position- and energy-resolving detection of neutral molecule fragments produced in electron–ion interactions at the Cryogenic Storage Ring at the Max Planck Institute for Nuclear Physics in Heidelberg. The detector is based on metallic magnetic calorimeters and consists of 4096 particle absorbers covering a total detection area of $$44.8\,\mathrm {mm} \times 44.8\,\mathrm {mm}$$ 44.8 mm × 44.8 mm . Groups of four absorbers are thermally coupled to a common paramagnetic temperature sensor where the strength of the thermal link is different for each absorber. This allows attributing a detector event within this group to the corresponding absorber by discriminating the signal rise times. A novel readout scheme further allows reading out all 1024 temperature sensors that are arranged in a $$32 \times 32$$ 32 × 32 square array using only $$16+16$$ 16 + 16 current-sensing superconducting quantum interference devices. Numerical calculations taking into account a simplified detector model predict an energy resolution of $$\Delta E_\mathrm {FWHM} \le 80\,\mathrm {eV}$$ Δ E FWHM ≤ 80 eV for all pixels of this detector.
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MOCCA: A 4k-Pixel Molecule Camera for the Position- and Energy-Resolving Detection of Neutral Molecule Fragments at CSR
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10.1007/s10909-015-1453-0
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2016-08-01
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The next generations of cosmic microwave background (CMB) instruments will be dedicated to the detection and characterization of CMB B-modes. To measure this tiny signal, instruments need to control and minimize systematics. Signal modulation is one way to achieve such a control. A new generation of focal planes will include the entire detection chain. In this context, we present a superconducting coplanar switch driven by DC current. It consists of a superconducting microbridge which commutes between its on (superconducting) and off (normal metal) states, depending on the amplitude of the injected current compared to the critical current. If the current injected inside the bridge is lower than the critical current, the phase of the signal passing through the bridge is tunable. A first prototype of this component working as a switch and as a phase shifter at 10 GHz has been made. The principle, the setup, and the first measurements made at 4 K will be shown.
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Superconducting Coplanar Switch and Phase Shifter for CMB Applications
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10.1007/s10909-016-1567-z
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2016-08-01
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The problem of the average ion energy in the gas discharge at cryogenic temperatures is analyzed. The dependences of the average ion energy on the reduced electric field strength and gas temperature are calculated by the Monte-Carlo method. A comparison with published data is performed and universal approximating dependences for all noble gases are obtained.
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On ion temperature in cryogenic discharge
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10.3103/S1068335616080017
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2016-08-01
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In the view of exploring the inverted hierarchy region future experiments investigating the neutrinoless double beta decay have to demand for detectors with excellent energy resolution and zero background in the energy region of interest. Cryogenic scintillating bolometers are very suitable detectors for this task since they provide particle discrimination: the simultaneous detection of the phonon and light signal allows us to identify the interacting type of particle and thus guarantees a suppression of $$\alpha $$ α -induced backgrounds, the key-issue for next-generation tonne-scale bolometric experiments. The LUCIFER project aims at running the first array of enriched scintillating Zn $$^{\text {82}}$$ 82 Se bolometers (total mass of about 8kg of $$^{\text {82}}$$ 82 Se) with a background level as low as 10 $$^{\text {--3}}$$ --3 counts/(keV kg y) in the energy region of interest. The main effort is currently focused on the finalization of the crystal growth procedure in order to achieve high quality Zn $$^{\text {82}}$$ 82 Se crystals both in terms of radiopurity and bolometric properties. We present results from tests of such crystals operated at mK temperatures which demonstrate the excellent background rejection capabilities of this detection approach towards a background-free demonstrator experiment. Besides, the high purity of the enriched $$^{\text {82}}$$ 82 Se material allows us to establish the most stringent limits on the half-life of the double beta decay of $$^{\text {82}}$$ 82 Se on excited levels.
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The LUCIFER Project: Achievements and Near Future Prospects
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10.1007/s10909-015-1423-6
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2016-08-01
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The detectors of the direct dark matter search experiment EDELWEISS consist of high-purity germanium crystals operated at cryogenic temperatures ( $$\mathrm {{<}20\,mK}$$ < 20 mK ) and low electric fields ( $$\mathrm {{<}1\,V/cm}$$ < 1 V / cm ). The surface discrimination is based on the simultaneous measurement of the charge amplitudes on different sets of electrodes. As the rise time of a charge signal strongly depends on the location of an interaction in the crystal, a time-resolved measurement can also be used to identify surface interactions. This contribution presents the results of a study of the discrimination power of the rise time parameter from a hot carrier transport simulation in combination with time-resolved measurements using an EDELWEISS-type detector in a test cryostat at ground level. We show the setup for the time-resolved ionization signal read-out in the EDELWEISS-III experiment and first results from data taking in the underground laboratory of Modane.
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Pulse-Shape Analysis of Ionization Signals in Cryogenic Ge Detectors for Dark Matter
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10.1007/s10909-016-1532-x
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2016-08-01
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To study the bonding properties between steel strand and concrete at room and cryogenic temperatures, a series of center pullout experiments were conducted on 96 bonding anchorage specimens at the lowest temperature of-165 °C. The impacts on the bonding property of such parameters as the temperature, concrete strength, the relative concrete cover thickness, and the relative anchorage length were analyzed. The test results indicate that the changes in temperature have a clear effect on the bonding property between steel strand and concrete. As the temperature decreases, the bond stress, which corresponds to a 1 mm slip of steel strand in relation to concrete, and the ultimate bond strength initially increase and subsequently decrease at the inflection point of-80 °C. The impact of the concrete strength on the bonding property, as shown by the tensile strength and the moisture content interaction, indicates that the bond stress vs concrete strength curve initially increases and later decreases with a decrease in temperature; the bond stress vs concrete cover thickness curve linearly increases, but the bond stress vs anchorage length curve linearly decreases at first and finally levels off.
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Experimental study on bonding properties between steel strand and concrete at cryogenic temperatures
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10.1007/s12209-016-2618-x
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2016-08-01
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Neutron transmutation-doped (NTD) Ge sensors have been prepared by irradiating device-grade Ge with thermal neutrons at Dhruva reactor, BARC, Mumbai. These sensors are intended to be used for the study of neutrinoless double beta decay in $$^{124}$$ 124 Sn with a superconducting Tin bolometer. Resistance measurements are performed on NTD Ge sensors in the temperature range 100–350 mK. The observed temperature dependence is found to be consistent with the variable-range hopping mechanism.
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Development of NTD Ge Sensors for Superconducting Bolometer
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10.1007/s10909-015-1379-6
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2016-08-01
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The CRESST-II (Cryogenic Rare Event Search with Superconducting Thermometers) experiment, whose second phase has been successfully finished in summer 2015, aims at the direct detection of dark matter particles. The intrinsic radiopurity of CaWO $$_4$$ 4 crystals, the capability to reject recoil events from alpha-surface contamination, and the energy threshold were significantly improved compared to previous runs of the experiment. A moderate exposure of 29 kg-days acquired by one $$\sim $$ ∼ 250 g CaWO $$_4$$ 4 detector provides competitive limits on the spin-independent dark matter particle-nucleon cross section and probes a new region of parameter space for dark matter particle masses below 3 GeV/c $$^2$$ 2 . The potential for low-mass dark matter particle search can be further exploited by a new detector design planned for CRESST-III. We describe the experimental strategy for the near future and give projections for the sensitivity.
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Exploring Low-Mass Dark Matter with CRESST
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10.1007/s10909-016-1492-1
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2016-08-01
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Structural transformations that occur in 110G13 steel (Hadfield) upon sliding friction in liquid nitrogen (–196°С) have been investigated by metallographic, electron-microscopic, and X-ray diffraction methods. The frictional action was performed through the reciprocating sliding of a cylindrical indenter of quenched 110G13 steel over a plate of the studied steel. A like friction pair was immersed into a bath with liquid nitrogen. It has been shown that the Hadfield steel quenched from 1100°С under the given temperature conditions of frictional loading retains the austenitic structure completely. The frictional action forms in a surface layer up to 10 μm thick the nanocrystalline structure with austenite grains 10–50 nm in size and a hardness 6 GPa. Upon subsequent low-temperature friction, the tempering of steel at 400°С (3 h) and at 600°С (5 min and 5 h) brings about the formation of a large amount (tens of vol %) of ε (hcp) martensite in steel. The formation of this phase under friction is supposedly a consequence of the reduction in the stacking fault energy of Hadfield steel, which is achieved due to the combined action of the following factors: low-temperature cooling, a decrease in the carbon content in the austenite upon tempering, and the presence of high compressive stresses in the friction-contact zone.
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Structural and phase transformations in Hadfield steel upon frictional loading in liquid nitrogen
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10.1134/S0031918X16080068
|
2016-08-01
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Cryogenic target based on indirect-drive concept is concerned widely in the inertial confinement fusion field. An indirect-drive cryogenic target is designed to field on the SGIII laser device of China. Capsule and hohlraum design refers to the NIF ignition target Rev5. The target fabrication encounters many engineering issues because of complicated structures and low temperature experimental environment. A tapered capillary is used to feed and support the capsule. And a jacket is designed to solve capillary fixing, gas filling, sealing and other structural issues. Forming a uniform fuel ice-layer on the capsule inner faces withstanding gravity or surface tension effect is a key feature of this cryogenic target. Thermal mechanical package is designed to have the best capacity of controlling temperature gradient across the capsule with a thermally noncontact method. Thermal analyses conclude the best interface conductance arguments and jacket material for the TMP design. Besides, structural reliability of the target after cooling is conservatively analyzed with an optimized model.
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Mechanical Design and Analysis of an Indirect-drive Cryogenic Target
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10.1007/s10894-016-0091-0
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2016-08-01
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The cryogenic underground observatory for rare events (CUORE) is a 1-ton scale bolometric experiment whose detector consists of an array of 988 TeO $$_2$$ 2 crystals arranged in a cylindrical compact structure of 19 towers. This will be the largest bolometric mass ever operated. The experiment will work at a temperature around or below 10 mK. CUORE cryostat consists of a cryogen-free system based on pulse tubes and a custom high power dilution refrigerator, designed to match these specifications. The cryostat has been commissioned in 2014 at the Gran Sasso National Laboratories and reached a record temperature of 6 mK on a cubic meter scale. In this paper, we present results of CUORE commissioning runs. Details on the thermal characteristics and cryogenic performances of the system will be also given.
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The CUORE Cryostat: A 1-Ton Scale Setup for Bolometric Detectors
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10.1007/s10909-015-1389-4
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2016-07-08
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The use of a $$\hbox {RuO}_{2}$$ RuO 2 resistor in non-isothermal measuring setup is proposed. A calculation is presented to explain the principle for a resistor obeying variable-range-hopping theory and the results are compared to measurements in the range of 11.2–30 mK for a commercial resistor. The thermometer, which measures the electron temperature, does not show overheating effects at 11.2 mK with a measuring power of $$10^{-12}$$ 10 - 12 W.
|
$$\hbox {RuO}_{2}$$
RuO
2
Non-isothermal Thermometry
|
10.1007/s10765-016-2076-7
|
2016-07-01
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A cryogenic 128:1 Time-Domain Multiplexer (TDM) has been developed for the readout of kilo-pixel Transition Edge Sensor (TES) arrays dedicated to the Q&U Bolometric Interferometer for Cosmology (QUBIC) instrument which aims to measure the B-mode polarization of the Cosmic Microwave Background. Superconducting QUantum Interference Devices (SQUIDs) are usually used to read out TESs. Moreover, SQUIDs are used to build TDM by biasing sequentially the SQUIDs connected together—one for each TES. In addition to this common technique which allows a typical 32 multiplexing factor, a cryogenic integrated circuit provides a 4:1 second multiplexing stage. This cryogenic integrated circuit is one of the original part of our TDM achieving an unprecedented 128 multiplexing factor. We present these two dimension TDM stages: topology of the SQUID multiplexer, operation of the cryogenic integrated circuit, and integration of the full system to read out a TES array dedicated to the QUBIC instrument. Flux-locked loop operation in multiplexed mode is also discussed.
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A 128 Multiplexing Factor Time-Domain SQUID Multiplexer
|
10.1007/s10909-015-1449-9
|
2016-07-01
|
There is a common need in astroparticle experiments such as direct dark matter detection, double-beta decay without emission of neutrinos [ $$0 \nu \beta \beta $$ 0 ν β β ] and coherent neutrino nucleus scattering experiments for light detectors with a very low energy threshold. By employing the Neganov–Trofimov–Luke Effect, the thermal 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. This technology is not used in current experiments, in particular because of a reduction of the signal amplitude with time which is due to trapping of the charges within the absorber. We present here the first results of a novel type of Neganov–Trofimov–Luke Effect light detector with an electric field configuration designed to improve the charge collection within the semiconductor.
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Cryogenic Silicon Detectors with Implanted Contacts for the Detection of Visible Photons Using the Neganov–Trofimov–Luke Effect
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10.1007/s10909-016-1534-8
|
2016-07-01
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The increasing sensitivity of high impedance cryogenic detectors demands amplification stages closer to detectors to guarantee high performance. We have developed a cryogenic installation to measure the intrinsic noise, the gain, and the DC characteristics of HEMTs or MOSFETs at low temperature. Components under test are mounted in a helium cryostat containing a double stage $$^{3}$$ 3 He/ $$^{4}$$ 4 He sorption cooler to perform sub-kelvin measurements. In this work, we describe this installation and present the encouraging first results that have revealed a level of intrinsic input voltage noise of a HEMT, developed by CNRS/LPN, of 0.44 nV/sqrt(Hz) at 1 kHz at 480 mK (Cin $$=$$ = 100 pF).
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First Measurement of the Intrinsic Noise of a HEMT at Sub-Kelvin Temperatures
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10.1007/s10909-016-1565-1
|
2016-07-01
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A flow diagram of gasification of a cryogenic liquid, which is based on the utilization of the liquid′s internal energy to obtain a vapor phase, has been presented. The limiting steam fractions of the two-phase flow in a gasifier have been evaluated as applied to the problems of gasification of methane. Consideration has been given to the conditions of phase separation in the field of mass forces. A numerical scheme of solution of a system of gasdynamic equations for the two-phase flow in a cylindrical coordinate system in a three-dimensional formulation has been implemented. The results of numerical modeling of the conditions of precipitation of particles with a diameter of 2 to 10 μm from a swirling dispersed flow have been presented; the role of the particle size in the dynamics of the process of phase separation has been established.
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Technology of Gasification of Liquefied Natural Gas
|
10.1007/s10891-016-1442-4
|
2016-07-01
|
We are developing far-infrared (FIR) imaging sensors for low-background and high-sensitivity applications such as infrared astronomy. Previous FIR monolithic imaging sensors, such as an extrinsic germanium photo-conductor (Ge PC) with a PMOS readout integrated circuit (ROIC) hybridized by indium pixel-to-pixel interconnection, had three difficulties: (1) short cut-off wavelength (120 $$\upmu $$ μ m), (2) large power consumption (10 $$\upmu $$ μ W/pixel), and (3) large mismatch in thermal expansion between the Ge PC and the Si ROIC. In order to overcome these difficulties, we developed (1) a blocked impurity band detector fabricated by a surface- activated bond technology, whose cut-off wavelength is longer than 160 $$\upmu $$ μ m, (2) a fully-depleted silicon-on-insulator CMOS ROIC which works below 4 K with 1 $$\upmu $$ μ W/pixel operating power, and (3) a new concept, Si-supported Ge detector, which shows tolerance to thermal cycling down to 3 K. With these new techniques, we are now developing a $$32 \times 32 $$ 32 × 32 FIR imaging sensor.
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Development for Germanium Blocked Impurity Band Far-Infrared Image Sensors with Fully-Depleted Silicon-On-Insulator CMOS Readout Integrated Circuit
|
10.1007/s10909-016-1522-z
|
2016-07-01
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The fatigue crack propagation (FCP) behavior of Fe25Mn and Fe16Mn2Al austenitic steels was investigated at 298 and 110 K, and the results were compared with the reported results of Fe24Mn2Cr steel. It was found that the FCP behavior of high-Mn, austenitic steels was largely influenced by the stacking fault energy (SFE) and the grain size. The resistance to FCP of high-Mn steels in this study was enhanced in the near-threshold ΔK regime with decreasing temperature from 298 to 110 K. The improvement for the Fe25Mn and the Fe16Mn2Al specimen was, however, marginal as compared to that of the Fe24Mn2Cr specimen. Other than the change in SFE, the secondary cracking at cryogenic temperature appeared to affect the FCP behavior of high-Mn steels, since the secondary cracks perpendicular to the crack propagating direction could reduce the effective stress intensity factor, decreasing the FCP rates. Sufficiently high stress concentration at grain boundary tended to occur at low temperature for relatively large grain sized Fe24Mn2Cr specimen and cause the secondary cracking, but not for the Fe25Mn and the Fe16Mn2Al specimen.
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Fatigue crack propagation behavior of Fe25Mn and Fe16Mn2Al steels at room and cryogenic temperatures
|
10.1007/s12540-016-6040-7
|
2016-07-01
|
The high-performance machining of difficult-to-cut alloys requires the development and optimization of high-performance tools, able to withstand the thermo-mechanical tool load without compromising the surface quality of produced components. In this context, the machinability of titanium aluminides still represents a demanding challenge. In this paper, the performance of cubic boron nitride (CBN) and polycrystalline diamond (PCD) cutting inserts is compared to that of uncoated and coated carbide tools. Longitudinal external turning tests were performed on a Ti-43.5Al-4Nb-1Mo-0.1B (TNM) at.% cast and hot isostatically pressed (HIPed) γ-TiAl alloy, by using a conventional lubrication supply. In addition, PCD tools were also applied under cryogenic cooling with liquid nitrogen. Results proved that PCD cutting tools have the potential to improve the machining productivity of titanium aluminides, due to their high hardness and excellent thermal conductivity. A noteworthy further increase of tool life was possible by using PCD cutting inserts under cryogenic cooling conditions.
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Tool life and surface integrity when turning titanium aluminides with PCD tools under conventional wet cutting and cryogenic cooling
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10.1007/s00170-015-7958-5
|
2016-07-01
|
As a part of an R&D program to improve the sensitivity of its detectors to low-mass ( $$<$$ < 10 GeV) weakly interacting massive particles, the Edelweiss dark matter collaboration is developing cryogenic ionization-and-heat coplanar grid germanium detectors, operated in a high-bias mode where advantage is taken of the voltage-assisted amplification of the ionization signals for enhanced sensitivity to low-energy ( $$<$$ < a few keV) interactions. First results of $$\upgamma $$ γ calibration experiments are presented for a 200 g prototype detector, capable of sustaining collection voltages up to 180 V with a corresponding gain of 60 in the heat measurement channel for electron recoil interactions. Event populations are analyzed based on ionization and heat data and on computer modeling of the detector signals, and a tentative interpretation of the results for the heat resolution is presented, involving athermal ballistic phonon losses in the device with consequent fluctuations in the thermometer response to the energy deposit of a particle.
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Voltage-Assisted Calorimetric Detection of Gamma Interactions in a Prototype Cryogenic Ge Detector of the EDELWEISS Collaboration for Dark Matter Search
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10.1007/s10909-016-1471-6
|
2016-07-01
|
A strongly basal textured AZ31 magnesium alloy were cryorolled at liquid-nitrogen temperature at various strains. The microstructure and texture of the rolled sheets have been investigated using electron backscatter diffraction (EBSD) and X-ray diffraction. The microstructural and textural evolutions of the AZ31 magnesium alloy during cryorolling have been discussed. A lot of twins were observed in the rolled sheets. The influence of strain on the twin types and variant selection during cryorolling for the magnesium alloy has been discussed quantitatively based on the orientation data collected using EBSD. The influence of the twins on the microstructural and textural evolutions for the AZ31 magnesium alloy during cryorolling has also been discussed. The mechanical properties of the cryorolled sheets were tested by uniaxial tensile tests at the ambient temperature with a strain rate 10^-3s^-1 in the tensile direction respectively along the rolling and transverse directions of the rolled sheets. The relationships between the mechanical properties and microstructure of the cryorolled sheets have been discussed in the present work. The active twinning during rolling at that cryogenic temperature has been found to play an important role in influencing the microstructure, texture, as well as the mechanical properties of the AZ31 magnesium alloy.
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Microstructure and mechanical properties of a basal textured AZ31 magnesium alloy cryorolled at liquid-nitrogen temperature
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10.1007/s12540-016-5645-1
|
2016-07-01
|
The goal of the Cryogenic wide-Area Light Detectors with Excellent Resolution project is the development of light detectors with large active area and noise energy resolution smaller than 20 eV RMS using phonon-mediated kinetic inductance detectors. The detectors are developed to improve the background suppression in large-mass bolometric experiments such as CUORE, via the double read-out of the light and the heat released by particles interacting in the bolometers. In this work, we present the design and the fabrication process, starting from the silicon wafer arriving to the single chip. The Al thin films (40 nm) are evaporated on high-quality, high-resistivity (> $$10\,\mathrm{k \Omega }\,$$ 10 k Ω cm) Si(100) substrates using an electron beam evaporator in a high-vacuum chamber. Detectors are patterned in direct-write mode, using electron beam lithography , positive tone resist poly-methyl methacrylate and lift-off process. Finally the wafer is diced into 20 $$\times $$ × 20 mm $$^2$$ 2 chips and assembled in a holder OFHC copper (oxygen-free high conductivity) using PTFE supports.
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Design and Fabrication of the KID-Based Light Detectors of CALDER
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10.1007/s10909-015-1452-1
|
2016-07-01
|
We present the design and noise performance of a fully cryogenic ( $$T=4$$ T = 4 K) high-electron mobility transistor (HEMT)-based charge amplifier for readout of sub-kelvin semiconductor radiation detectors. The amplifier is being developed for use in direct detection dark matter searches such as the cryogenic dark matter search and will allow these experiments to probe weakly interacting massive particle masses below 10 GeV/ $$c^2$$ c 2 while retaining background discrimination. The amplifier dissipates $$\approx $$ ≈ 1 mW of power and provides an open loop voltage gain of several hundreds. The measured noise performance is better than that of JFET-based charge amplifiers and is dominated by the noise of the input HEMT. An optimal filter calculation using the measured closed loop noise and typical detector characteristics predicts a charge resolution of $$\sigma _q$$ σ q =106 eV (35 electrons) for leakage currents below $$4 \times 10^{-15}$$ 4 × 10 - 15 A.
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An HEMT-Based Cryogenic Charge Amplifier for Sub-kelvin Semiconductor Radiation Detectors
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10.1007/s10909-016-1475-2
|
2016-07-01
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Microstructure evolution and hardness variation in AISI D2 steel were investigated after cryogenic treatment at 173 or 123 K. Statistical analysis using STATGRAPHICS and analysis of variance (ANOVA) were carried out in order to identify the most important process parameters on the variation of hardness. In addition to process parameters such as heating rate, cooling rate, holding time, and tempering temperature, the influence of surface density of carbides as microstructural variable is also included in the statistical analysis. The obtained results indicated equal impacts on the hardness for the as-cooled condition, while for the as-tempered samples, the most significant factor was found to be the tempering temperature. A regression equation taking into account all the critical variables is proposed, and very good approximation to the experimental hardness values was obtained. Precipitation of transition carbides and their influence on the extent of martensite recovery are considered as possible mechanisms responsible for hardness evolution after cryogenic treatment.
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Influence of cryogenic process parameters on microstructure and hardness evolution of AISI D2 tool steel
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10.1007/s00170-015-7980-7
|
2016-07-01
|
SRON is developing ultra-low-noise transition edge sensors (TESs) based on a superconducting Ti/Au bilayer on a suspended SiN island with SiN legs for SAFARI aboard SPICA. We have two major concerns about realizing TESs with an ultra-low NEP of $$2\times 10^{-19}~\hbox {W}/\sqrt{{\text {Hz}}}$$ 2 × 10 - 19 W / Hz : achieving lower thermal conductance and no excess noise with respect to the phonon noise. To realize TESs with phonon-noise-limited NEPs, we need to make thinner ( $${<}0.25~\upmu \hbox {m}$$ < 0.25 μ m ) and narrower ( $${<}1~\upmu \hbox {m}$$ < 1 μ m ) SiN legs. With deep reactive-ion etching, three types of TESs were fabricated in combination with different SiN island sizes and the presence or absence of an optical absorber. Those TESs have a thin $$(0.20~\upmu \hbox {m}$$ ( 0.20 μ m ), narrow (0.5–0.7 $$\upmu \hbox {m}$$ μ m ), and long (340–460 $$\upmu \hbox {m}$$ μ m ) SiN legs and show $$T_{\mathrm {c}}$$ T c of $${\sim }93~\hbox {mK}$$ ∼ 93 mK and $$R_{\mathrm {n}}$$ R n of $${\sim }158~\hbox {m}{\Omega }$$ ∼ 158 m Ω . These TESs were characterized under AC bias using our frequency-division multiplexing readout (1–3 MHz) system. TESs without the absorber show NEPs as low as $$1.1\,\times \,10^{-19}~\hbox {W}/\sqrt{{\text {Hz}}}$$ 1.1 × 10 - 19 W / Hz with a reasonable response speed ( $${<}1~\hbox {ms}$$ < 1 ms ), which achieved the phonon noise limit. For TESs with the absorber, we confirmed a higher $$\hbox {NEP}_{\mathrm {el}} ({\sim }5\,\times \,10^{-19}~\hbox {W}/\sqrt{{\text {Hz}}}$$ NEP el ( ∼ 5 × 10 - 19 W / Hz ) than that of TESs without the absorber likely due to stray light. The lowest NEP can make the new version of SAFARI with a grating spectrometer feasible.
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Development of Ultra-Low-Noise TES Bolometer Arrays
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10.1007/s10909-015-1401-z
|
2016-06-16
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An investigation of the temperature-dependent friction behavior of PTFE, MoS_2, and PTFE-on-MoS_2 is presented. Friction behavior was measured while continuously varying contact temperature in the range −150 to 175 °C while sliding in dry nitrogen, as well as for self-mated PTFE immersed in liquid nitrogen. These results contrast with previous reports of high-friction transitions and plateaus for pure and composite MoS_2 at temperatures below about −20 °C; instead, we have found persistently weak thermal behavior between 0 and −196 °C, providing new insight about the molecular mechanisms of macroscale friction. The temperature-dependent friction behavior characteristic of self-mated PTFE was found also for PTFE-on-MoS_2 sliding contacts, suggesting that PTFE friction was defined by subsurface deformation mechanisms and internal friction even when sliding against a lamellar lubricant with extremely low friction coefficient ( µ ~ 0.02). The various relaxation temperatures of PTFE were found in the temperature-dependent friction behavior, showing excellent agreement with reported values acquired using rheological techniques measuring energy dissipation through internal friction. Additionally, hysteresis in friction behavior suggests an increase in near-surface crystallinity upon exceeding the high-temperature relaxation, T _ α ~ 116 °C.
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Temperature-Dependent Friction and Wear Behavior of PTFE and MoS_2
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10.1007/s11249-016-0702-y
|
2016-06-11
|
The objective of this work is to study the effect of deposited $$\hbox {CO}_{2}$$ CO 2 on the solid thermal conductivity of a cryogenic insulation system. Therefore, measurements were performed using a guarded hot plate apparatus at temperatures in the range from 80 K to 290 K in combination with a bellow acting as the sample containment. The unique experimental setup and sample preparation are described in detail. Furthermore, existing thermal models which are based on a superposition of thermal transfer due to radiation and solid thermal conductivity were modified to account for the thermal effects of deposited gases and the consequently increased solid thermal conductivity for a spherical powder. Measurements showed a significant increase of the solid thermal conductivity depending on the amount of $$\hbox {CO}_{2}$$ CO 2 that was provided for deposition–evacuation. 2.77 Vol-‰ $$\hbox {CO}_{2}$$ CO 2 resulted in an increase of 5.5 % in the overall solid thermal conductivity. Twice this amount (5.54 Vol-‰ $$\hbox {CO}_{2}$$ CO 2 ) and four times this amount (11.1 Vol-‰ $$\hbox {CO}_{2}$$ CO 2 ) resulted in an increase of $$8.8\,\%$$ 8.8 % and 14.1 % in the overall solid thermal conductivity, respectively. Due to additional temperature sensors, it was possible to measure the effective thermal conductivity in different layers of the insulation material. Thus, a significant change in the innermost layer of $$75\,\%$$ 75 % was measured for the solid thermal conductivity comparing the evacuated sample with the $$\hbox {CO}_{2}$$ CO 2 -loaded (11.1 Vol-‰ $$\hbox { CO}_{2})$$ CO 2 ) sample.
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Thermal Characterization and Effect of Deposited
$$\hbox {CO}_{2}$$
CO
2
on a Cryogenic Insulation System Based on a Spherical Powder
|
10.1007/s10765-016-2087-4
|
2016-06-01
|
The influence of soaking time in deep cryogenic treatment on the tensile and impact properties of low-alloy medium-carbon HY-TUF steel was investigated in this study. Microstructural studies based on phase distribution mapping by electron backscatter diffraction show that the deep cryogenic process causes a decrease in the content of retained austenite and an increase in the volume fraction of η-carbide with increasing soaking time up to 48 h. The decrease in the content of retained austenite from ~1.23vol% to 0.48vol% suggests an isothermal martensitic transformation at 77 K. The η-type precipitates formed in deep cryogenic-treated martensite over 48 h have the Hirotsu and Nagakura orientation relation with the martensitic matrix. Furthermore, a high coherency between η-carbide and the martensitic matrix is observed by high-resolution transmission electron microscopy. The variations in macrohardness, yield strength, ultimate tensile strength, and ductility with soaking time in the deep cryogenic process show a peak/plateau trend.
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Influence of soaking time in deep cryogenic treatment on the microstructure and mechanical properties of low-alloy medium-carbon HY-TUF steel
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10.1007/s12613-016-1278-0
|
2016-06-01
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Effect of cryogenic grinding on recovery of volatile oil, fatty oil percentage and their constituents in two cumin ( Cuminum cyminum L.) genotypes have been analyzed. Cryogenic grinding not only retains the volatiles but enhanced the recovery by 33.9 % in GC 4 and 43.5 % in RZ 209. A significant increase (29.9 %) over normal grinding in oil percentage was also observed in genotype RZ 209. This increase was, however, less (15.4 %) in genotype GC 4. Nineteen major compounds were identified in the essential oil of both genotypes. The two grinding techniques had significant effects on dependent variables, viz., volatile oil and monoterpenes. Cuminaldehyde was the main constituent in both genotypes, content of which increased from 48.2 to 56.1 % in GC 4 on cryo grinding. Content of terpines were found to decrease in cryo ground samples of GC 4 and either decrease or no change was found in RZ 209. Organoleptic test showed more pleasant aroma in cryo ground seeds of both the genotypes. Significant increase was also reported in fatty oil yield due to cryogenic grinding. Fatty acid methyl ester (FAME) analysis showed oleic acid as major FAME content of which increased from 88.1 to 94.9 % in RZ 209 and from 88.2 to 90.1 % in GC 4 on cryogenic grinding. Other prominent FAME were palmitic, palmitoleic and stearic acid. Results indicated commercial potential of cryogenic grinding technology for cumin in general and spices in particular for better retention of flavour and quality in spices.
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Effect of cryogenic grinding on volatile and fatty oil constituents of cumin (Cuminum cyminum L.) genotypes
|
10.1007/s13197-016-2258-0
|
2016-06-01
|
The effect of shallow cryogenic treatment (SCT) on the microstructure and mechanical properties of Al7075-T6 is investigated in the present work. The alloy was subjected to shallow CT at −80 °C for 72 h. Mechanical tests such as Vickers hardness test, tensile, and fatigue tests were performed on both native and treated samples. It was observed that the mechanical properties such as hardness, yield strength, and ultimate tensile strength increased by about 30, 17, and 7%, respectively, for the treated sample. The treated alloy was characterized by using the techniques such as optical microscopy, electron back scattered diffraction (EBSD), energy-dispersive x-ray spectroscopy (EDS), and transmission electron microscopy (TEM) to observe the changes in the microstructural features. EBSD results show precipitation, better distribution of second-phase particles, and higher dislocation density in the treated alloy as compared to the untreated alloy. The treatment imparts improved hardness and strength to the alloy due to precipitation hardening and high dislocation density. Fracture morphologies of the treated and the native samples were characterized by using scanning electron microscopy and it was observed that the striations were denser in the treated sample justifying the higher fatigue strength.
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Microstructure and Mechanical Behavior of Al 7075-T6 Subjected to Shallow Cryogenic Treatment
|
10.1007/s11665-016-2052-1
|
2016-06-01
|
This paper includes computational analysis of the behavior of concrete subjected to cryogenic temperatures. The analysis is performed by developing a computationally implemented meso-scale model of concrete as a 3-phase composite that consists of mortar matrix, aggregate, and interfacial transition zone. The modeling results provide insight on the effects of concrete mixture design and properties on resistance to damage during cooling to cryogenic temperatures. The results show that the most important factor that affects damage is the difference in the coefficient of thermal expansion between the mortar and aggregates. Models in which the mortar and aggregate had close values of positive coefficients are predicted to experience less damage. The modeled material with irregular shape particles is predicted to experience more localized damage than the modeled material with circular shape particles. In addition, the model predicts a reduction in damage when air entrainment is present. The damage results predicted by the model for air entrained and non-air entrained concrete are in general agreement with experimental data from the literature.
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Meso-scale model for simulations of concrete subjected to cryogenic temperatures
|
10.1617/s11527-015-0639-x
|
2016-05-01
|
It is proposed to use the HTSC quantum levitation phenomenon in magnetic fields of various configurations to develop the systems of contact-free positioning and transport of cryogenic fuel targets (CFTs) to the focus of a high-power laser installation or the IFE reactor. The results are presented of a large cycle of experimental studies using YBa_2Cu_3O_7− x superconducting ceramics and permanent magnet guideways based on various combinations of permanentmagnets to develop “CFT-MAGLEV” delivery systems.
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On the possibility of developing the non-contact delivery system for cryogenic thermonuclear target transport to the IFE reactor
|
10.3103/S1068335616050031
|
2016-05-01
|
The present work reports on the application and the evaluation of a multitude of crosslinking approaches including high-energy irradiation, redox-initiating systems and conventional carbodiimide-coupling chemistry for frozen and/or freeze-dried porous gelatin scaffolds. The latter is particularly relevant for a plethora of biomedical applications such as tissue engineering supports, wound dressings, adhesive and absorbent pads for surgery, etc. Moreover, the results obtained for gelatin can be considered a proof-of-concept to be extrapolated to other polymer systems containing double bonds and/or amines and carboxylic acids to also realize scaffold crosslinking in dry or frozen state. The results showed that high-energy irradiation at −5 °C enabled sufficient segmental mobility to induce chemical crosslinking after performing a cryogenic treatment of methacrylamide-modified gelatin scaffolds. Alternatively, although several redox-initiating systems were unable to chemically crosslink functionalized gelatin, the combination of ammonium persulphate and TEMED resulted in the formation of scaffolds with a reasonable gel fraction. Interestingly, carbodiimide-coupling was found suitable to crosslink freeze-dried gelatin matrices.
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Crosslinking strategies for porous gelatin scaffolds
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10.1007/s10853-016-9747-4
|
2016-05-01
|
The detailed chemical information contained in the vibrational spectrum of a cryogenically cooled analyte ion would, in principle, make infrared (IR) ion spectroscopy a gold standard technique for molecular identification in mass spectrometry. Despite this immense potential, there are considerable challenges in both instrumentation and methodology to overcome before the technique is analytically useful. Here, we discuss the promise of IR ion spectroscopy for small molecule analysis in the context of metabolite identification. Experimental strategies to address sensitivity constraints, poor overall duty cycle, and speed of the experiment are intimately tied to the development of a mass-selective cryogenic trap. Therefore, the most likely avenues for success, in the authors’ opinion, are presented here, alongside alternative approaches and some thoughts on data interpretation. Graphical Abstract ᅟ
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Making Mass Spectrometry See the Light: The Promises and Challenges of Cryogenic Infrared Ion Spectroscopy as a Bioanalytical Technique
|
10.1007/s13361-016-1366-4
|
2016-05-01
|
Microstructural evolution and mechanical properties of cryogenic rolled Fe-36Ni steel were investigated. The annealed Fe-36Ni steel was rolled at cryogenic temperature (123–173 K) with 20%–90% rolling reduction in thickness. The deformation process was accompanied by twinning at cryogenic temperature, and the mean thickness of deformation twins was about 200 nm with 20% rolling reduction. When the rolling reduction was above 40%, twinning was suppressed due to the stress concentration in the tested steel. Deformation microstructure of Fe-36Ni steel consisted of both twin boundaries and dislocations by cryogenic rolling (CR), while it only contained dislocations after rolling at room temperature (RT). The tensile strength of Fe-36Ni steel was improved to 930 MPa after 90% reduction at cryogenic temperature, while the tensile strength after 90% reduction at RT was only 760 MPa. More dislocations could be produced as the nucleation sites of recrystallization during CR process.
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Deformation behavior of Fe-36Ni steel during cryogenic (123–173 K) rolling
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10.1016/S1006-706X(16)30071-1
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2016-04-01
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Stainless steel (SS) is sensitized by a thermal treatment in the range of 400–850 °C and inter-granular attack would occur upon subsequent exposure to certain media. In many practical situations, such as welding, sensitization is best studied by continuous cooling through the sensitizing temperature range wherein the variables are the peak temperature reached and the cooling rate in contrast to temperature and time of the isothermal hold which has been the customary practice. There are also various methods of controlling the inter-granular corrosion viz. lowering the carbon content, adding stabilizers and applying solution heat treatment but all these methods are either costly or difficult to apply. This study is focussed on the effect of cryogenically treated tungsten electrode of TIG welding on the sensitization behaviour of 304SS by taking into consideration the weld properties (like: hardness, tensile strength, percentage elongation and micro-structure). The parameters of significance are current, pulse frequency and gas flow rate. Further the study suggested that the results of non cryo treated electrode were better than the treated one on sensitization of welded joints during TIG welding within the range of selected parameters.
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Effect of Cryogenic Treatment on Sensitization of 304 Stainless Steel in TIG Welding
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10.1007/s40032-015-0214-9
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2016-04-01
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The thermal physics processes of solid target cooling at proton beam irradiation in С18 cyclotron were calculated. The calculations were made with the help of finite-elements method using ANSYS program for beams with nonuniform density of particle distribution in the beam profile. It was shown that the radiation efficiency and conditions of target cooling essentially depend on distributions of particles in the beam and on efficient size of beam. A principal possibility of the cryocooling of target is shown that would essentially increase the radiation efficiency and the yield of final product–the medical isotope ^99mTc. The developed calculation method may be of use also for other processes of target irradiation with charged particle beams.
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Theoretical justification of the possibility of cryocooling of a solid target at irradiation with proton beam from cyclotron C18
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10.3103/S106833721602002X
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2016-04-01
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Continuous cooling transformation behavior of a low carbon bainite microalloyed cryogenic pressure vessel steel was analyzed to explore transformation mechanism of super-cooled austenite on MMS-300 thermomechanical simulator. Microstructure transformation laws of steel at various cooling rates were determined by means of dilatometric measurement and microstructure observation. The results showed that the bainite microstructure was formed in broad range of cooling rate 5–30 °C/s. The martensitic transformation existed above 50 °C/s and the martensitic microstructure was dominated above 150 °C/s. The martensitic transformation temperature was first increased and then decreased with the increase of cooling rate in the range of 1–30 °C/s and the final transformation of bainite and martensite would move toward higher temperature at higher cooling rate.
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Effect of Continuous Cooling Rate on Transformation Characteristic in Microalloyed Low Carbon Bainite Cryogenic Pressure Vessel Steel
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10.1007/s12666-015-0564-2
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2016-04-01
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P ure copper was compressed at high strain rates (over ~3 × 10^3 s^−1) under liquid nitrogen. This deformation resulted in bi-modal microstructures of ultrafine grains and abnormally grown micro grains, and in greater hardness (by ~30 Hv) than room-temperature, dynamically deformed copper. This bi-modal microstructure is attributable to partial recrystallization at room temperature, activated by high-energy states and by twins generated at high Zener–Hollomon parameter conditions. This result demonstrates a new approach for producing bi-modally structured materials.
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Bi-modal Structure of Copper via Room-Temperature Partial Recrystallization After Cryogenic Dynamic Compression
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10.1007/s11661-016-3326-9
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2016-04-01
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Selective concentration of ultra-trace components in air-like gases has an important application in analyzing volatile organic compounds in the gas. In the present study, we examined quench-condensation of the sample gas on a ZnO substrate below 50 K followed by temperature programmed desorption (TPD) (low temperature TPD) as a selective gas concentration technique. We studied two specific gases in the normal air; krypton as an inert gas and acetone as a reactive gas. We evaluated the relationship between the operating condition of low temperature TPD and the lowest detection limit. In the case of krypton, we observed the selective concentration by exposing at 6 K followed by thermal desorption at about 60 K. On the other hand, no selectivity appeared for acetone although trace acetone was successfully concentrated. This is likely due to the solvent effect by a major component in the air, which is suggested to be water. We suggest that pre-condensation to remove the water component may improve the selectivity in the trace acetone analysis by low temperature TPD.
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Temperature Programmed Desorption of Quench-condensed Krypton and Acetone in Air; Selective Concentration of Ultra-trace Gas Components
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10.2116/analsci.32.449
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2016-04-01
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In a bid to better conserve endangered terrestrial orchids, we detail cryogenic research using a widely distributed terrestrial orchid, Caladenia latifolia , as a model species for development of cryopreservation for primary (seed generated) and secondary (adventitious) protocorms. Primary protocorm cryopreservation (using droplet vitrification) involved a number of experimental lines of inquiry: investigation of a suitable plant vitrification solution (PVS) by comparing three variants of a standard PVS (2, 3 and 4), determining the most suitable primary protocorm developmental stage for successful cryopreservation, testing the effectiveness of a preculture medium treatment prior to cryopreservation, and investigating temperature preconditioning at the preculture stage as well as different components of the recovery medium. Primary protocorms were generated using asymbiotic in vitro germination media developed by the authors specifically for the test species (half-strength MS macroelements and microelements with 5% ( v / v ) fresh filter sterilized coconut water). Secondary protocorms were propagated using an in vitro proliferation medium (½ MS with 5 μM α-naphthaleneacetic acid + 2 μM 6-benzylaminopurine). A modified preconditioning step was developed, involving incubation on ½ MS with 0.2 M raffinose for 48 h at 15°C instead of 20°C. The standard recovery medium (½ MS 1 μM zeatin + 0.5 μM gibberellic acid) was replaced after the first week following warming from liquid nitrogen (LN), with asymbiotic germination medium (½ MS + 5% ( v/v ) coconut water) for the remainder of the recovery phase. This new step increased the survival of primary protocorms from 68 to 85%. The average post-cryostorage regeneration of plants from primary protocorms increased from 17 to 48% after a 6-wk incubation. A similar protocol increased the survival of secondary protocorms from 63 to 84%. Regeneration of plants from secondary cryostored protocorms increased from 11 to 26% after 14 wk. The protocols developed here provide a useful template for advancing cryoconservation of other orchid taxa, particularly rare and threatened species.
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A cryopreservation protocol for ex situ conservation of terrestrial orchids using asymbiotic primary and secondary (adventitious) protocorms
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10.1007/s11627-015-9732-7
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2016-03-23
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The time-resolved measurements of thermally induced wavefront aberrations in a cryogenically cooled Yb:YAG crystal are presented in dependence on temperature in the range between 250 and 130 K under non-lasing condition. A wavefront sensor was utilized to determine the wavefront aberrations. The wavefront distortions were experimentally studied for a cryogenically cooled Yb:YAG crystal in detail for the first time. The wavefront aberrations were significantly reduced at cryogenic temperatures including defocus which was the dominant aberration and which was responsible for the so-called thermal lensing effect. We found that defocus aberration is caused not only by thermally induced effects (responsible for thermal lens), but also by electronically induced change in the refractive index due to excitation of ion activators which is responsible for the electronic lensing. Nevertheless, at pumping intensity of 6.3 kW/cm^2 and repetition rate of 100 Hz thermal effects were the dominant one. In addition, an improvement in the Strehl ratio along with an increase in absorbed pump energy was observed while the temperature of the gain medium was decreased. The measurements clearly show the advantages of cryogenic cooling of laser-active media for beam quality improvement.
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Time-resolved measurement of thermally induced aberrations in a cryogenically cooled Yb:YAG slab with a wavefront sensor
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10.1007/s00340-016-6342-y
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2016-03-01
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A method to obtain analytical expressions for evaluation of adsorption isotherms of neon isotopes at cryogenic temperatures is proposed. Adsorption isotherms of ^20Ne and ^22Ne on BAU activated carbon at 77 K are evaluated. The results allow the degree of influence of the pressure and composition of the ^20Ne–^22Ne isotopic mixture on the separation factor to be estimated.
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Comparative Analysis of Various Adsorbents for Low-Temperature Separation of a ^20Ne–^22Ne Isotopic Mixture
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10.1007/s10556-016-0115-7
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2016-03-01
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It is shown that in the case of well-developed infrastructure for the use of liquid nitrogen the usage of nitrogen cryosorption pumps (NCP) is significantly more economical compared to the pumping means associated with the use of mechanical and steam jet pumps. The results of preliminary tests of the experimental sample NCP as part of a vacuum unit at the NPO Geliymash confirm the prospects of using NCPs in serial production of cryogenic vessels.
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The Economics of Cryosorption Pumping. The Practice of Using a Cryosorption Pump in an Industrial Pumping System
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10.1007/s10556-016-0130-8
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2016-03-01
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In this study, high-strength AA7075 alloy samples were cryogenically forged after annealing and then subjected to solution and aging treatments. The cryogenically forged 7075-T73 alloy samples displayed equiaxed fine grains associated with abundant fine precipitates in their matrix. Compared with conventional 7075-T73 alloy samples, the cryogenically forged samples exhibited an 8-12% reduction in tensile strength and an increased fatigue strength and higher corrosion resistance. The fatigue strength measured at 10^7 cycles was 225 MPa in the bare samples; the strength was increased to 250 MPa in the cryogenically forged samples. The effect of anodization on the corrosion resistance of the bare samples was improved from ( E _corr) −0.80 to −0.61 V.
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Effects of Cryogenic Forging and Anodization on the Mechanical Properties of AA 7075-T73 Aluminum Alloys
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10.1007/s11665-016-1946-2
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2016-03-01
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In order to reduce the adverse effects on environment and avoid health problems caused by the excessively used cutting fluids, a green machining technology, minimum quantity lubrication (MQL), is drawing more and more attention. The cryogenic minimum quantity lubrication (CMQL) technique which combines the advantages of cryogenic air and MQL can improve cooling and lubricating performances during machining H13 steel. Internal cooling cutters have been widely employed to feed the cutting medium to the cutting zone directly. In this research work, cutting forces and tool wear were analyzed during side milling H13 steel with three kinds of internal cooling milling cutters under CMQL condition. The experimental results showed that the milling cutter with double straight channel (DSC) performed best in extending tool life and reducing cutting forces. In the perspective of economy and environmental protection, internal cooling cutter with DSC is recommended in cutting of H13 steel under CMQL condition.
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Effects of internal cooling channel structures on cutting forces and tool life in side milling of H13 steel under cryogenic minimum quantity lubrication condition
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10.1007/s00170-015-7644-7
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