Cryopreservation of hamster pancreatic islets using a rapid cooling rate

1991 ◽  
Vol 21 (5) ◽  
pp. 547-555 ◽  
Author(s):  
Wataru Fukushima ◽  
Masayuki Note ◽  
Yasuhiko Kojima ◽  
Gizo Nakagawara
Keyword(s):  
Pancreatic Islets ◽  
Cooling Rate ◽  
Rapid Cooling

40Ar/39Ar and K–Ar age constraints on shear zone evolution, southern Taltson magmatic zone, northeastern Alberta

1995 ◽  
Vol 32 (3) ◽  
pp. 281-291 ◽  
Author(s):  
H. E. Plint ◽  
M. R. McDonough
Keyword(s):  
Cooling Rate ◽  
Shear Zone ◽  
High Grade ◽  
Slow Cooling ◽  
Rapid Cooling ◽  
Deformational History ◽  
The Mean ◽  
Exhumation Rates ◽  
Northeastern Alberta ◽  
Age Constraints

New 40Ar/39Ar analyses of hornblende, muscovite, biotite, and K-feldspar constrain the timing of deformation and cooling of the southern Taltson magmatic zone, which underwent lower granulite to upper amphibolite grade deformation, in part synchronous with voluminous 1.99–1.92 Ga magmatism. New data are combined with existing K–Ar dates into a regional cooling framework to provide thermotemporal constraints on the deformational history. 40Ar/39Ar hornblende ages of ca. 1900 Ma are interpreted to record relatively rapid cooling following ductile thrusting on the Andrew Lake shear zone, and younger anatectic magmatism. These data, with published K–Ar and U–Pb data, support relatively rapid cooling of the Taltson magmatic zone from monazite closure temperature of 725 °C at ca. 1930 Ma to 525 °C at ca. 1900 Ma. Cooling rate estimates are about 7 °C/Ma, which suggests moderate exhumation rates during the high-grade part of the deformational history. A muscovite 40Ar/39Ar plateau age of 1803 ± 11 Ma is consistent with the mean muscovite K–Ar age of 1792 Ma, indicating regional cooling through about 350 °C at ca. 1800 Ma. 40Ar/39Ar ages from magmatic biotite of 1856 and 1799 Ma also suggest slow cooling during greenschist grade deformation, which can be no older than ca. 1860 Ma. A K-feldspar 40Ar/39Ar age of 1681 Ma provides a lower limit for the time of greenschist grade deformation. Cooling rate estimates during amphibolite to greenschist grade deformation are 1.75–2.25 °C/Ma.

Fabrication of Lead Free Micro Solder Powder by Melts Dispersion Technique

2006 ◽  
Vol 510-511 ◽  
pp. 570-573
Author(s):  
Jeong Il Youn ◽  
Won Ha ◽  
Young Jig Kim
Keyword(s):  
Cooling Rate ◽  
Irregular Shape ◽  
Lead Free ◽  
Oil Viscosity ◽  
Rapid Cooling ◽  
Critical Cooling Rate ◽  
New Process ◽  
Dispersion Technique ◽  
Shape And Size

A new process, melts dispersion technique, was developed to fabricate the solder powder in oil surroundings by forming molten metal’s droplets. The main parameters of the technique on shape and size of powders were investigated in the present paper. It is shown that a cooling rate of the melts and viscosity of oil for isolation of droplets affect the shape and the size. The cooling rate is a very important parameter, and there is a critical cooling rate at given conditions. Although the melts were dispersed perfectly in oil, fine droplets were merged and coalesced during solidification without rapid cooling. The shape of powder has an influence mainly on oil viscosity and was altered into a sphere from an irregular shape with increasing oil viscosity.

Boar semen can tolerate rapid cooling rates prior to freezing

2011 ◽  
Vol 23 (5) ◽  
pp. 681 ◽  
Author(s):  
Jorge D. Juarez ◽  
Inma Parrilla ◽  
Juan M. Vazquez ◽  
Emilio A. Martinez ◽  
Jordi Roca
Keyword(s):  
Cooling Rate ◽  
Flow Cytometric Analysis ◽  
Membrane Integrity ◽  
Annexin V ◽  
Objective Evaluation ◽  
Membrane Lipid ◽  
Cooling Rates ◽  
Rapid Cooling ◽  
Motile Cells ◽  
Boar Spermatozoa

Two experiments were performed in the present study that demonstrated that boar spermatozoa are capable of surviving rapid cooling rates within a range of 15–5°C before freezing. Boar ejaculates diluted in Beltsville thawing solution (BTS) (1 : 1, v/v) were held at 17–20°C and shipped over a 24-h time period from two AI centres to a cryobiology laboratory, where they were pooled (Experiment 1) or cryopreserved individually (Experiment 2) using a standard 0.5-mL straw freezing protocol. The effects of cooling before freezing were assessed after thawing through the objective evaluation of sperm motility and flow cytometric analysis of membrane integrity, acrosomal status, changes in membrane lipid architecture monitored by merocyanine and annexin V binding and intracellular production of reactive oxygen species. In Experiment 1 (six replicates), two semen pools (five ejaculates per pool) were cooled from 15 to 5°C at rates of 0.08, 0.13, 0.40 and 1.50°C min–1. These cooling rates did not result in any significant differences (P > 0.05) in any of the post-thaw sperm assessments, even in thawed samples incubated under capacitation conditions. In Experiment 2, three individual ejaculates from 16 boars were slowly (0.08°C min–1) or rapidly (1.5°C min–1) cooled before freezing. A consistent interboar variability (P < 0.01) was detected, which was independent of the cooling rate used. Cooling rate only significantly influenced (P < 0.05) sperm assessments in four of 16 boars, which exhibited slightly higher percentages of motile cells and intact plasma and acrosomal membranes in the samples that had been cooled slowly. These findings demonstrate that boar spermatozoa undergoing cryopreservation can withstand rapid cooling rates before freezing.

Structure properties of CuNi alloys at the rapid cooling rate using embedded-atom method

2002 ◽  
Vol 326 (2) ◽  
pp. 343-347 ◽  
Author(s):  
Hong-Ri Cong ◽  
Xiu-Fang Bian ◽  
Jing-Xiang Zhang ◽  
Hui Li
Keyword(s):  
Cooling Rate ◽  
Embedded Atom Method ◽  
Rapid Cooling ◽  
Ni Alloys ◽  
Embedded Atom ◽  
Structure Properties

Slow and rapid cooling of Al–Cu–Si ultrafine eutectic composites: Interplay of cooling rate and microstructure in mechanical properties

2019 ◽  
Vol 34 (08) ◽  
pp. 1381-1394 ◽  
Author(s):  
Guilherme Lisboa de Gouveia ◽  
Rafael Kakitani ◽  
Leonardo Fernandes Gomes ◽  
Conrado Ramos Moreira Afonso ◽  
Noé Cheung ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Cooling Rate ◽  
Rapid Cooling ◽  
Image Position

Abstract

scholarly journals K/Ar mineral geochronology of the northern part of the Sithonia Plutonic Complex (Chalkidiki, Greece): implications for its thermal history and geodynamic interpretation

2013 ◽  
Vol 64 (2) ◽  
pp. 133-140 ◽  
Author(s):  
Kyriaki Pipera ◽  
Antonis Koroneos ◽  
Triantafyllos Soldatos ◽  
Zoltán Pécskay ◽  
Georgios Christofides
Keyword(s):  
Cooling Rate ◽  
Thermal History ◽  
Rapid Cooling ◽  
Isotopic System ◽  
Plutonic Complex ◽  
History Of ◽  
Shed Light

Abstract New K/Ar mineral ages of thirty nine samples (biotite, muscovite, K-feldspar) from the two-mica granodiorite to granite and leucogranite of the northern part of the Sithonia Plutonic Complex (Chalkidiki, Greece) are given in the present study. These data along with existing Rb/Sr mica and U/Pb zircon ages are used to investigate the thermal history of the plutonic complex and shed light on the process that affected it, and caused discordant Rb/Sr and K/Ar mineral ages. The K/Ar mineral dating yielded ages ranging from 38 to 49 Ma for muscovites, 32 to 47 Ma for biotites and 37 to 43 Ma for K-feldspars, respectively. The comparison of the K/Ar, Rb/Sr and U/Pb mineral ages and the closure temperatures of the different isotopic systems for the different minerals indicate a rapid cooling rate for the Sithonia pluton. The latter supports the hypothesis that the pluton was formed in a post orogenic extensional regime. Moreover, the K/Ar mineral isochrones indicate that a reheating of the pluton took place before 37 Ma and partially rejuvenated the K/Ar and Rb/Sr isotopic system of the minerals

Use of Similarity Analysis on Experiments of Different Size to Predict Critical Cooling Rates for Large Ceramic Waste Forms

2008 ◽  
Author(s):  
Kenneth J. Bateman ◽  
Charles W. Solbrig
Keyword(s):  
Thermal Stress ◽  
Cooling Rate ◽  
Fission Products ◽  
Similarity Analysis ◽  
Cylindrical Shape ◽  
Analytical Prediction ◽  
Rapid Cooling ◽  
Critical Cooling Rate ◽  
Ceramic Waste ◽  
Waste Forms

Ceramic waste forms (CWF) are produced to store fission products for the long term. They are cast into cylindrical shape at high temperature (925°C). Rapid cooling of the product is desirable for product turnaround, but cooling has the potential to crack the coalesced product into many pieces due to thermal stress. This paper investigates the rapid-cooling process with a borosilicate-glass component of the CWF used as a surrogate. The critical cooling rate of formed cylinders (the rate which separates the damage from the no-damage region) has been determined. This paper extends previous experimental data and analysis to production temperature as a step in the extrapolation of the data to production CWF’s. The glass solidifies in the range of 650°C to 625°C. The previous tests (7.8-cm diameter) were all run starting from a solid (625°C or less) to provide a basis for the higher temperature cases. Thermal stress cannot build up until solidification begins to occur. The current tests (7.8 and 9.9cm diameter) were run from the liquid temperature of 925°C. A theoretical model has been developed to analyze the data. The model includes heat transfer and the stress developed from the thermal gradients. Similarity analysis based on this model is used to produce dimensionless charts which allow data of different initial temperatures and diameters to be analyzed. The new data corroborated the previous estimate of the critical cooling rate and analytical-model projection for the minimum in-furnace cooling times for two production size CWF’s that will be stored in Yucca Mountain (70 hours for the 52-cm diameter and 35 days for the 181.5-cm sizes). To further reduce these times, an analytical prediction was made which shows that the formed cylinder can be removed from a furnace at a temperature of 320°C without any danger of cracking.

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