Showing papers in "Cryogenics in 2012"

TL;DR: In this paper, the performance and influence of cryogenic coolants such as CO2 and LN2 on cutting temperature, cutting force, tool wear, surface finish and chip morphology in machining of AISI 1045 steel compared to wet machining was investigated.

TL;DR: In this paper, the experimental results of a cryogenic chilldown process are reported, which involve unsteady two-phase vapor-liquid flow and intense boiling heat transfer of the cryogenic fluid that is coupled with the transient heat conduction inside pipe walls.

TL;DR: In this paper, the authors present the results of an experimental investigation of the thermal and hydraulic performance of a printed circuit heat exchanger (PCHE) for use in the cryogenic temperature region.

TL;DR: In this article, the effects of the temperature and the contact pressure on the TCR at interfaces were analyzed and the relationship between TCR and the temperature at certain contact pressure was established, and the explanation about this phenomenon was given.

TL;DR: In this paper, a model of a generator-driven thermoelectric refrigerator with external heat transfer was proposed, where the authors analyzed the performance of the combination of finite time thermodynamics and non-equilibrium thermodynamics, and derived two analytical formulae for cooling load vs. working electrical current.

TL;DR: In this article, the authors developed a 1-D thermal model to understand the effect of the gas flow parameters on the thermal gradients along a 30m-long simulated superconducting cable in a flexible cryostat.

TL;DR: In this article, the effect of multi-stream heat exchanger on the performance of natural gas (NG) liquefaction with mixed refrigerant (MR) was investigated, and the local energy balance equations were rigorously solved with temperature-dependent properties of MR and NG feed, and were linked to the thermodynamic cycle analysis.

TL;DR: In this article, a cycle-averaged relationship for heat transfer, magnetic work, and temperature distribution is derived for an active magnetic regenerator cycle, assuming small regenerative perturbations and used to derive the net cooling power and magnetic work at any location in the AMR.

TL;DR: In this article, the cavitation flow instability of subcooled liquid nitrogen in two types of converging-diverging (C-D) circular nozzles with throat diameters of 1.5 and 2.0mm was experimentally investigated.

TL;DR: In this article, Spray-on Foam Insulation (SOFI) has been used on the cryogenic tanks of space launch vehicles to prevent ice formation and avoid in-flight damage to the ceramic tile thermal protection system on the adjacent Orbiter.

TL;DR: In this paper, the authors investigated the influence of the low pressure refrigerant mixing position in recuperators on the performance of an auto-cascade refrigerator operating with a rectifying column in theory and experiment.

TL;DR: In this article, an experimental set up named HELIOS has been designed and realized in CEA Grenoble to study pulsed load effects on a forced flow supercritical helium loop.

TL;DR: Astro-H is the Japanese X-ray astronomy satellite planned for launch in 2014 as discussed by the authors, which is equipped with a high energy resolution spectrometer with a 30-L superfluid liquid helium (LHe).

TL;DR: In this paper, a multi-shell structure with ferroferric oxide as core, dense nonporous silica as inter layer and mesoporous silica outer layer was synthesized by co-precipitation method and poly methyl acrylate was formed on the surface of the nanoparticle.

TL;DR: In this paper, the influence of temperature on the magnetic behavior of nickel zinc ferrite nanoparticles impregnated thermoplastic natural rubber was investigated in the temperature range of 10-300 K.

TL;DR: A Superconducting Magnetic Energy Storage System (SMES), one of such apparatus, consists of superconducting magnets that must withstand high voltage during operation and require high reliability, has been developed for protecting industrial facilities such as semiconductor plants or information industries from instantaneous voltage dips as discussed by the authors.

TL;DR: In this article, the authors have developed the silver-sheathed Bi2223 multi-filamentary wires with I c of 200 ǫ and maximum I c reached 250 Ã c at 77 Ã k by short sample.

TL;DR: In this article, a two-stage micro-JT micro-cooler with a cooling capacity of about 10 mW at 100 K and a lower temperature of about 30 K was proposed.

TL;DR: In this paper, the authors developed a gravity-insensitive dilution refrigerator adapted from the open-cycle refrigerator used for the Planck mission, where the 3 He and 4 He components are circulated (the 4 He by a fountain-effect pump operating at about 2 K, the 3 H by a compressor at room temperature) rather than ejected into space.

TL;DR: In this article, a 40-k single-stage coaxial high frequency pulse tube cryocoolers (PTCs) have been developed to provide reliable and low-noise cooling for GaAs/AlGaAs Quantum-Well infrared photodetectors (QWIPs).

TL;DR: The relationship between the wavelength shift and temperature could be characterized by a three-order polynomial as mentioned in this paper, where the wavelength shifts were linear with the longitudinal strain and increased with lower temperature.

TL;DR: In this paper, a miniature cryogenic loop heat pipe (CLHP) with nitrogen as the working fluid was designed and experimentally investigated to assist the supercritical startup of the primary evaporator.

TL;DR: In this paper, a three-dimensional numerical simulation code (SLUSH-3D), including the gravity effect based on the thermal non-equilibrium, two-fluid model, was constructed to clarify the flow and heat-transfer characteristics of cryogenic slush fluids in a horizontal circular pipe.

TL;DR: The Primordial Inflation Explorer (PIXIE) as discussed by the authors is a mission to densely map the polarization of the cosmic microwave background (CME) using low temperature detectors (at 0.1 K) and located inside a telescope that is cooled to approximately 2.73 K to match the background temperature.

TL;DR: In this article, the thermal expansion of a hybrid carbon-fiber reinforced silicon carbide composite, HB-Cesic®, was measured in the temperature region of ∼310-10 k. The results indicated that the residual anisotropy was reduced down to 4% as a result of hybridization.

TL;DR: In this article, the heat transfer limits of two cryogenic thermosyphons with different cooling conditions and filling ratios are experimentally studied and discussed and the mechanism behind the dry-out limit at high filling ratios is analyzed and the critical heat flux is predicted by a model that describes the heat and mass balance of the working fluid.

TL;DR: In this article, the authors report on testing with liquid oxygen (LOX) at elevated pressures and thus temperatures (maximum pressure 1724 kPa and maximum temperature 122 K) as part of NASA's continuing cryogenic LAD development program.

TL;DR: The critical current densities (J c ) and stabilities of tube Type Nb 3 Sn conductors have been measured as discussed by the authors, and the most stable strands showed stability currents, J s, of 8700 A/mm 2 and 15,300 A/m 2 for 0.7mm OD and 0.42mm OD conductors, respectively.

TL;DR: In this article, the surface modification of ZrW 2 O 8 powders was performed to improve the dispersion of fillers in epoxy matrix, plasma polymerization was performed on the surface.

TL;DR: The Japanese Astro-H mission will include the Soft X-ray Spectrometer (SXS) instrument provided by NASA/GSFC as discussed by the authors, which will perform imaging spectroscopy in the soft Xray band using a 6 × 6 array of silicon microcalorimeters operated at 50 mK.