Modification of superconducting and resistive properties of HoBa2Cu3O7−δ single crystals under application-removal of high hydrostatic pressure

2016 ◽  
Vol 30 (17) ◽  
pp. 1650188 ◽  
Author(s):  
R. V. Vovk ◽  
G. Ya. Khadzhai ◽  
O. V. Dobrovolskiy ◽  
S. N. Kamchatna ◽  
A. Chroneos
Keyword(s):  
High Pressure ◽  
Hydrostatic Pressure ◽  
Single Crystals ◽  
Basal Plane ◽  
High Hydrostatic Pressure ◽  
Electrical Resistance ◽  
Phonon Scattering ◽  
Phase Segregation ◽  
Temperature Dependences ◽  
Electron Phonon Scattering

The influence of a high hydrostatic pressure on the basal-plane electrical resistance along the twin boundaries in underdoped HoBa2Cu3O[Formula: see text] single crystals is investigated. An enhancement of the phase segregation caused by the high-pressure-induced redistribution of the labile oxygen has been revealed. The temperature dependences of the electrical resistance above [Formula: see text] can be approximated well within the framework of the model of [Formula: see text] electron–phonon scattering.

Effect of high pressure on various diffusion mechanisms in oxygen-deficient ReBa2Cu3O7−x (Re = Y, Ho) single crystals

2019 ◽  
Vol 33 (04) ◽  
pp. 1950039
Author(s):  
G. Ya. Khadzhai ◽  
N. R. Vovk ◽  
R. V. Vovk ◽  
I. L. Goulatis ◽  
O. V. Dobrovolskiy
Keyword(s):  
High Pressure ◽  
Electrical Resistivity ◽  
Hydrostatic Pressure ◽  
Single Crystals ◽  
High Hydrostatic Pressure ◽  
Room Temperature ◽  
Diffusion Mechanisms ◽  
Diffusion Coalescence

The effect of high hydrostatic pressure on the relaxation of the electrical resistivity at room temperature of oxygen-nonstoichiometric [Formula: see text] (Re = Y, Ho) single crystals is investigated. The application of hydrostatic pressure has been revealed to significantly intensify the process of diffusion coalescence in the oxygen subsystem. At the same time, the intensity of the redistribution of labile oxygen is significantly changed when yttrium is replaced by holmium.

Effect of High Hydrostatic Pressure on Salmonella Inoculated into Creamy Peanut Butter with Modified Composition

2014 ◽  
Vol 77 (10) ◽  
pp. 1664-1668 ◽  
Author(s):  
TANYA D'SOUZA ◽  
MUKUND KARWE ◽  
DONALD W. SCHAFFNER
Keyword(s):  
High Pressure ◽  
Hydrostatic Pressure ◽  
Water Activity ◽  
High Hydrostatic Pressure ◽  
Peanut Butter ◽  
High Pressure Processing ◽  
Peanut Oil ◽  
Peanut Flour ◽  
Log Reduction ◽  
High Hydrostatic Pressure Processing

Peanut butter has been associated with several large foodborne salmonellosis outbreaks. This research investigates the potential of high hydrostatic pressure processing (HPP) for inactivation of Salmonella in peanut butter of modified composition, both by modifying its water activity as well by the addition of various amounts of nisin. A cocktail of six Salmonella strains associated with peanut butter and nut-related outbreaks was used for all experiments. Different volumes of sterile distilled water were added to peanut butter to increase water activity, and different volumes of peanut oil were added to decrease water activity. Inactivation in 12% fat, light roast, partially defatted peanut flour, and peanut oil was also quantified. Nisaplin was incorporated into peanut butter at four concentrations corresponding to 2.5, 5.0, 12.5, and 25.0 ppm of pure nisin. All samples were subjected to 600 MPa for 18 min. A steady and statistically significant increase in log reduction was seen as added moisture was increased from 50 to 90%. The color of all peanut butter samples containing added moisture contents darkened after high pressure processing. The addition of peanut oil to further lower the water activity of peanut butter further reduced the effectiveness of HPP. Just over a 1-log reduction was obtained in peanut flour, while inactivation to below detection limits (2 log CFU/g) was observed in peanut oil. Nisin alone without HPP had no effect. Recovery of Salmonella after a combined nisin and HPP treatment did show increased log reduction with longer storage times. The maximum log reduction of Salmonella achieved was 1.7 log CFU/g, which was comparable to that achieved by noncycling pressure treatment alone. High pressure processing alone or with other formulation modification, including added nisin, is not a suitable technology to manage the microbiological safety of Salmonella-contaminated peanut butter.

scholarly journals High-Pressure Inactivation of Hepatitis A Virus within Oysters

2005 ◽  
Vol 71 (1) ◽  
pp. 339-343 ◽  
Author(s):  
Kevin R. Calci ◽  
Gloria K. Meade ◽  
Robert C. Tezloff ◽  
David H. Kingsley
Keyword(s):  
High Pressure ◽  
Hydrostatic Pressure ◽  
High Hydrostatic Pressure ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Natural Conditions ◽  
Direct Evaluation ◽  
Temperature Range

ABSTRACT Previous results demonstrated that hepatitis A virus (HAV) could be inactivated by high hydrostatic pressure (HHP) (D. H. Kingsley, D. Hoover, E. Papafragkou, and G. P. Richards, J. Food Prot. 65:1605-1609, 2002); however, direct evaluation of HAV inactivation within contaminated oysters was not performed. In this study, we report confirmation that HAV within contaminated shellfish is inactivated by HHP. Shellfish were initially contaminated with HAV by using a flowthrough system. PFU reductions of >1, >2, and >3 log10 were observed for 1-min treatments at 350, 375, and 400 megapascals, respectively, within a temperature range of 8.7 to 10.3�C. Bioconcentration of nearly 6 log10 PFU of HAV per oyster was achieved under simulated natural conditions. These results suggest that HHP treatment of raw shellfish will be a viable strategy for the reduction of infectious HAV.

scholarly journals Эффективные кристаллы Bi-Sb для термоэлектрического охлаждения при температурах T≲180 K

2019 ◽  
Vol 53 (5) ◽  
pp. 693
Author(s):  
Н.А. Сидоренко ◽  
З.М. Дашевский
Keyword(s):  
Hydrostatic Pressure ◽  
Single Crystals ◽  
High Hydrostatic Pressure ◽  
Polycrystalline Material ◽  
High Strength ◽  
Strength Properties ◽  
Experimental Equipment ◽  
Liquid Environment

Methods of extrusion are widely used in technology of thermoelectric (TE) materials manufacturing with high strength and good TE properties at temperatures above 200 K. The method of extrusion of Bi - Sb single crystals in the liquid environment under high hydrostatic pressure is considered. The construction of experimental equipment is presented. It was shown that presented method of extrusion allows preparing of polycrystalline material with high TE and improved strength properties at temperatures below 180 K.

Effect of high hydrostatic pressure on the phonon modes of Tb3Al5O12 and Dy3Al5O12 single crystals

1999 ◽  
Vol 265 (1-4) ◽  
pp. 277-281 ◽  
Author(s):  
K. Papagelis ◽  
J. Arvanitidis ◽  
G. Kanellis ◽  
S. Ves ◽  
G.A. Kourouklis
Keyword(s):  
Hydrostatic Pressure ◽  
Single Crystals ◽  
High Hydrostatic Pressure ◽  
Phonon Modes

scholarly journals The multifaceted effects of DMSO and high hydrostatic pressure on the kinetic constants of hydrolysis reactions catalyzed by α-chymotrypsin

2020 ◽  
Vol 22 (28) ◽  
pp. 16325-16333
Author(s):  
Lena Ostermeier ◽  
Rosario Oliva ◽  
Roland Winter
Keyword(s):  
High Pressure ◽  
Hydrostatic Pressure ◽  
High Hydrostatic Pressure ◽  
Kinetic Constants ◽  
Antagonistic Effects ◽  
Hydrolysis Reactions

The cosolvent DMSO and high pressure have antagonistic effects on the kinetic constants of α-chymotrypsin-catalyzed hydrolysis reactions.

scholarly journals Alicyclobacillus acidoterrestris Strain Variability in the Inactivation Kinetics of Spores in Orange Juice by Temperature-Assisted High Hydrostatic Pressure

2020 ◽  
Vol 10 (21) ◽  
pp. 7542
Author(s):  
Patra Sourri ◽  
Anthoula A. Argyri ◽  
Efstathios Z. Panagou ◽  
George-John E. Nychas ◽  
Chrysoula C. Tassou
Keyword(s):  
High Pressure ◽  
Hydrostatic Pressure ◽  
Orange Juice ◽  
High Hydrostatic Pressure ◽  
Reference Strain ◽  
Wild Type Strain ◽  
Weibull Model ◽  
Inactivation Kinetics ◽  
High Pressure Level ◽  
Kinetics Of

In this work, the inactivation kinetics of Alicyclobacillus acidoterrestris spores by temperature-assisted high hydrostatic pressure was assessed by means of the Weibull model. Spores from two A. acidoterrestris strains (a wild-type strain and a reference strain) were inoculated in commercial orange juice and subjected to high pressure levels (500 and 600 MPa) combined with four temperature regimes (25, 45, 60 and 70 °C) for time up to 30 min. Results showed that for a given high-pressure level spore inactivation was higher as temperature progressively increased. Furthermore, the Weibull model consistently produced satisfactory fit to the inactivation data based on the values of the root mean squared error (RMSE < 0.54 log colony-forming units (CFU)/mL) and the coefficient of determination (R2 > 0.90 in most cases). The shape of inactivation curves was concave upward (p < 1) for all temperature/high pressure levels tested, indicating rapid inactivation of the sensitive cells of the bacterium whereas the remaining ones adapted to high hydrostatic pressure (HHP) treatment. The values of the shape (p) and scale (δ) parameters of the Weibull model were dependent on the applied temperature for a given high pressure level and they were further described in a secondary model using first-order fitting curves to provide predictions of the surviving spore population at 55 and 65 °C. Results revealed a systematic over-prediction for the wild-type strain regardless of temperature and high pressure applied, whereas for the reference strain under-prediction was evident after 3 log-cycles reduction of the surviving bacteria spores. Overall, the results obtained indicate that the effectiveness of high hydrostatic pressure against A. acidoterrestris spores is strain-dependent and also underline the need for temperature-assisted HPP for effective spore inactivation during orange juice processing.

Phase segregation and the effect of high pressure on the electro-transport in Y0.95Pr0.05Ba2Cu3O7-δ single crystals

2014 ◽  
Vol 28 (17) ◽  
pp. 1450142 ◽  
Author(s):  
Ruslan V. Vovk ◽  
Georgij Ya. Khadzhai ◽  
Oleksandr V. Dobrovolskiy
Keyword(s):  
High Pressure ◽  
Critical Temperature ◽  
Single Crystals ◽  
Oxygen Content ◽  
Pressure Effect ◽  
Phase Segregation ◽  
Sample Volume ◽  
Pressure Derivative ◽  
High Hydrostatic Pressures ◽  
High Pressure Effect

The effect of high hydrostatic pressures of up to 17 kbar on the basal ab-plane conductivity of lightly praseodymium-doped (x ≈ 0.05) Y 1-x Pr x Ba 2 Cu 3 O 7-δ single crystals with unidirectional twin boundaries (TBs) is investigated. It is observed that the application of a high pressure leads to a doubling of the pressure derivative value dTc/dP for Pr -doped samples compared to non-doped YBa 2 Cu 3 O 7-δ samples with optimal oxygen content. Possible mechanisms of the high pressure effect on the critical temperature Tc and the phase segregation in the sample volume are discussed.

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