Exploration of the best reference material on anelastic measurement by cyclic loading under high pressure

2021 ◽  
pp. 1-15
Author(s):  
Chao Liu ◽  
Takashi Yoshino ◽  
Daisuke Yamazaki ◽  
Noriyoshi Tsujino ◽  
Hitoshi Gomi ◽  
...  
Author(s):  
Joshua D. Turner ◽  
Brian J. O’Rourke ◽  
Ian J. Jordaan ◽  
Rocky S. Taylor

Ice-structure interactions produce numerous, short-lived high pressure zones which transfer the majority of the load to the structure. Ice indentation tests have been used to observe the fluctuations in surface temperature at these zones. Previous investigations have shown that temperature fluctuates inversely to the applied load during cyclic loading. These fluctuations are believed to be due to rapid melting and refreezing cycles in the high pressure zones. A recent series of small-scale indentation tests investigated surface temperature fluctuations for indentor speeds at three orders of magnitude (0.21 mm/s to 21 mm/s). Freshwater granular ice specimens were grown in cylindrical steel moulds using seed ice and distilled water. A 70 mm diameter indentor with a radius of curvature of 89.6 mm was indented into the ice to depths between 10 and 15 mm. Seven thermocouples were installed in the indentor and made flush with its surface. These were used to measure the surface temperature of the ice during indentation. All tests took place at −10 degrees. Notable changes in temperature response were observed with changing speed. A steady increase in temperature was observed during low speed tests. Medium speeds lead to fluctuations in temperature due to the presence of spalling and cyclic loading that is consistent with the results of others. Some evidence of the inverse relationship between load and temperature can be observed in the highest speed tests, but the thermocouples sampling frequency was too low to accurately respond to high frequency loading and could not provide clear results.


2016 ◽  
Vol 87 (10) ◽  
pp. 105106
Author(s):  
Takashi Yoshino ◽  
Daisuke Yamazaki ◽  
Yoshinori Tange ◽  
Yuji Higo

Adsorption ◽  
2020 ◽  
Vol 26 (8) ◽  
pp. 1253-1266
Author(s):  
H. G. T. Nguyen ◽  
C. M. Sims ◽  
B. Toman ◽  
J. Horn ◽  
R. D. van Zee ◽  
...  

Abstract This paper reports the results of an international interlaboratory study led by the National Institute of Standards and Technology (NIST) on the measurement of high-pressure surface excess methane adsorption isotherms on NIST Reference Material RM 8850 (Zeolite Y), at 25 °C up to 7.5 MPa. Twenty laboratories participated in the study and contributed over one-hundred adsorption isotherms of methane on Zeolite Y. From these data, an empirical reference equation was determined, along with a 95% uncertainty interval (Uk=2). By requiring participants to replicate a high-pressure reference isotherm for carbon dioxide adsorption on NIST Reference Material RM 8852 (ZSM-5), this interlaboratory study also demonstrated the usefulness of reference isotherms in evaluating the performance of high-pressure adsorption experiments.


2005 ◽  
Vol 290 ◽  
pp. 222-229
Author(s):  
Luca Ceseracciu ◽  
Francis Chalvet ◽  
Emilio Jiménez-Piqué ◽  
Marc Anglada ◽  
Goffredo de Portu

In this work, the study of the contact fatigue of an alumina-based laminated composite with compressive residual stress in the surface is presented, together with monolithic alumina as a reference material. Hertzian indentation techniques were employed, which better represent the inservice actual contact loading. Different tests were performed under static and cyclic loading. The evolution of damage and the different types of fracture produced were examined, and an improvement in contact resistance of the composite, due to compressive residual stress, was highlighted. A better resistance of the laminated composite was observed for every test in comparison with the monolithic reference material.


1996 ◽  
Vol 14 (2) ◽  
pp. 113-123 ◽  
Author(s):  
A.M. Evans ◽  
N.J. Freeman ◽  
P. Graham ◽  
C.J. Horsfield ◽  
S.D. Rothman ◽  
...  

The AWE HELEN laser is being used to measure high-pressure Hugoniot data by the impedance match method. Indirect drive is used to generate pressures of up to 10 Mbar in the aluminum reference material. We are aiming to measure shock velocities in our targets to ± 1 %, leading to errors in pressure and particle velocity of the order of ±2%. This requires improvements in target fabrication and characterization, streak camera calibration and data analysis, coupled with investigations into shock planarity and attenuation. Our latest results have accuracies of 2–4% in shock velocity but have identified work that should allow us to achieve our intended level of accuracy. Experiments have been done with copper and chlorinated plastic; our results are compared with theory, and, for copper, with U.S. and Russian gas-gun, explosively or nuclear-driven experiments.


2020 ◽  
Vol 26 (3) ◽  
pp. 104-110
Author(s):  
Janette Brezinova ◽  
Miroslav Džupon ◽  
Jan Vinas ◽  
Anna Guzanová ◽  
Viktor Puchý ◽  
...  

The paper presents the results of the research focused on the possibility of renewal of molded parts of molds in high-pressure casting of aluminum alloys by cladding welding. Two materials - Thermanit 625 and Thermanit X - were tested. Weld-on layers were produced by CMT - Cold Metal Transfer technology in a protective atmosphere of Ar. The cllad resistance in the molten melt of the aluminum alloy EN AB AlSi8Cu3 for 120 and 300 minutes was evaluated. Furthermore, ball-on-disc wear resistance of welds was assessed. The results were compared with the reference material - AISI / SAE 309 base tool steel.


Author(s):  
Marek Malecki ◽  
James Pawley ◽  
Hans Ris

The ultrastructure of cells suspended in physiological fluids or cell culture media can only be studied if the living processes are stopped while the cells remain in suspension. Attachment of living cells to carrier surfaces to facilitate further processing for electron microscopy produces a rapid reorganization of cell structure eradicating most traces of the structures present when the cells were in suspension. The structure of cells in suspension can be immobilized by either chemical fixation or, much faster, by rapid freezing (cryo-immobilization). The fixation speed is particularly important in studies of cell surface reorganization over time. High pressure freezing provides conditions where specimens up to 500μm thick can be frozen in milliseconds without ice crystal damage. This volume is sufficient for cells to remain in suspension until frozen. However, special procedures are needed to assure that the unattached cells are not lost during subsequent processing for LVSEM or HVEM using freeze-substitution or freeze drying. We recently developed such a procedure.


Author(s):  
Robert Corbett ◽  
Delbert E. Philpott ◽  
Sam Black

Observation of subtle or early signs of change in spaceflight induced alterations on living systems require precise methods of sampling. In-flight analysis would be preferable but constraints of time, equipment, personnel and cost dictate the necessity for prolonged storage before retrieval. Because of this, various tissues have been stored in fixatives and combinations of fixatives and observed at various time intervals. High pressure and the effect of buffer alone have also been tried.Of the various tissues embedded, muscle, cartilage and liver, liver has been the most extensively studied because it contains large numbers of organelles common to all tissues (Fig. 1).


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