Strain Effects on the Tunneling Levels of KCl: Li

1970 ◽  
Vol 25 (12) ◽  
pp. 1844-1855 ◽  
Author(s):  
B. Dischler
Keyword(s):  
Specific Heat ◽  
Average Energy ◽  
Preceding Paper ◽  
Experimental Results ◽  
Strain Effects ◽  
Schottky Anomaly ◽  
A Value ◽  
Internal Strains

Abstract The effects of internal strains on the tunneling levels of KCl : Li are investigated quantitatively. The method, as developed in a preceding paper by TIMME, DISCHLER, and ESTLE1 , is further improved here. A reinterpretation is presented for two experimental results reported in the literature: the resonances in the phonon spectrometer curve and the specific heat (Schottky) anomaly. The agreement with these experiments and also with paraelectric resonance is good, if isotropic strains are assumed with an average energy of 20 GHz, corresponding to a stress of 30 ± 10 kp/cm2 . For the cube edge tunneling interaction a value of 10 GHz is derived.

An anomaly in the specific heat below 3 °K of copper containing hydrogen

1969 ◽  
Vol 47 (14) ◽  
pp. 1485-1491 ◽  
Author(s):  
Neil Waterhouse
Keyword(s):  
Specific Heat ◽  
Molecular Hydrogen ◽  
Pure Copper ◽  
Solid Hydrogen ◽  
Rotational State ◽  
Experimental Results ◽  
Ortho Hydrogen ◽  
Temperature Range ◽  
A Value ◽  
Heat Curve

The specific heat of copper heated in hydrogen at 1040 °C has been measured over the temperature range 0.4 to 3.0 °K and found to be anomalous. The anomaly occurs in the same temperature range as the solid hydrogen λ anomaly which, in conjunction with evidence of ortho to para conversion of hydrogen in the sample, suggests the presence of molecular hydrogen in the copper. The anomaly reported by Martin for "as-received" American Smelting and Refining Company (ASARCO) 99.999+ % pure copper has been briefly compared with the present results. The form of the anomaly produced by the copper-hydrogen specimen has been compared with Schottky curves using the simplest possible model, that for two level splitting of the degenerate J = 1 rotational state of the ortho-hydrogen molecule.Maintenance of the copper-hydrogen sample at ~20 °K for approximately 1 week removed the "hump" in the specific heat curve. An equation of the form Cp = γT + (464.34/(θ0c)3)T3 was found to fit these experimental results and produced a value for γ which had increased over that for vacuumannealed pure copper by ~2%.

scholarly journals Appendix: Mathematical approaches to the evaluation of the flux of γ-aminobutyrate in brain tissue in vitro

1970 ◽  
Vol 116 (3) ◽  
pp. 461-467 ◽  
Author(s):  
B. J. Hammond ◽  
T. Julian ◽  
Y. Machiyama ◽  
R. Balázs
Keyword(s):  
Computer Simulation ◽  
Tricarboxylic Acid Cycle ◽  
Preceding Paper ◽  
Experimental Results ◽  
Simulation Methods ◽  
Metabolic Compartmentation ◽  
A Value ◽  
Time Courses ◽  
Cortex Slices

In the preceding paper (Balázs, Machiyama, Hammond, Julian & Richter, 1970) the flux of γ-aminobutyrate (GABA) was found, in guinea-pig brain-cortex slices incubated in glucose–saline medium, to represent about 10% of the total tricarboxylic acid cycle flux, as opposed to other estimates, which are as high as 40%. However, the latter value was deduced from experimental results by methods that made no allowance for the metabolic compartmentation of glutamate: a mathematical investigation was therefore undertaken to show that this omission necessarily leads to an overestimation of GABA flux. The magnitude of this over-estimation was shown by computer simulation methods to be of such an order as to bring the corrected value into agreement with the lower value. Computer simulation methods were also used to evaluate the GABA flux from the experimental results presented by Balázs et al. (1970) and a value of 0.0315μmol/min per g wet wt. was obtained. This value was also shown to be consistent, in the simulated system, with the experimentally observed time-courses for the radioactivity and quantity of aspartate. Since there is now evidence that GABA is itself a metabolically compartmented intermediate this possibility was considered mathematically, but it was found that in this case the assumption of compartmentation had little effect upon the value of GABA flux deduced on the basis of GABA homogeneity.

Experimental Study on the Specific Heat Capacity Measurement of Water-Based Al2O3-Cu Hybrid Nanofluid by using Differential Thermal Analysis Method

2019 ◽  
Vol 15 ◽  
Author(s):  
Andaç Batur Çolak ◽  
Oğuzhan Yıldız ◽  
Mustafa Bayrak ◽  
Ali Celen ◽  
Ahmet Selim Dalkılıç ◽  
...  
Keyword(s):  
Heat Capacity ◽  
Specific Heat ◽  
Specific Heat Capacity ◽  
Thermophysical Properties ◽  
Volume Concentration ◽  
Pure Water ◽  
Heat Capacity Measurement ◽  
Experimental Results ◽  
Hybrid Nanofluid ◽  
Capacity Measurement

Background: Researchers working in the field of nanofluid have done many studies on the thermophysical properties of nanofluids. Among these studies, the number of studies on specific heat are rather limited. In the study of the heat transfer performance of nanofluids, it is necessary to increase the number of specific heat studies, whose subject is one of the important thermophysical properties. Objective: The authors aimed to measure the specific heat values of Al2O3/water, Cu/water nanofluids and Al2O3-Cu/water hybrid nanofluids using the DTA method, and compare the results with those frequently used in the literature. In addition, this study focuses on the effect of temperature and volume concentration on specific heat. Method: The two-step method was used in the preparation of nanofluids. The pure water selected as the base fluid was mixed with the Al2O3 and Cu nanoparticles and Arabic Gum as the surfactant, firstly mixed in the magnetic stirrer for half an hour. It was then homogenized for 6 hours in the ultrasonic homogenizer. Results: After the experiments, the specific heat of nanofluids and hybrid nanofluid were compared and the temperature and volume concentration of specific heat were investigated. Then, the experimental results obtained for all three fluids were compared with the two frequently used correlations in the literature. Conclusion: Specific heat capacity increased with increasing temperature, and decreased with increasing volume concentration for three tested nanofluids. Cu/water has the lowest specific heat capacity among all tested fluids. Experimental specific heat capacity measurement results are compared by using the models developed by Pak and Cho and Xuan and Roetzel. According to experimental results, these correlations can predict experimental results within the range of ±1%.

An Analysis of Conventional and Self-Aligned four Terminal Resistor Structures for The Determination of The Contact Resistivity from End Resistance Measurements

1986 ◽  
Vol 71 ◽  
Author(s):  
I. Suni ◽  
M. Finetti ◽  
K. Grahn
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Computer Model ◽  
Contact Resistivity ◽  
Experimental Results ◽  
The Finite Element Method ◽  
Model Based ◽  
A Value ◽  
And Diffusion

AbstractA computer model based on the finite element method has been applied to evaluate the effect of the parasitic area between contact and diffusion edges on end resistance measurements in four terminal Kelvin resistor structures. The model is then applied to Al/Ti/n+ Si contacts and a value of contact resistivity of Qc = 1.8×10−7.Ωcm2 is derived. For comparison, the use of a self-aligned structure to avoid parasitic effects is presented and the first experimental results obtained on Al/Ti/n+Si and Al/CoSi2/n+Si contacts are shown and discussed.

scholarly journals The Specific Heat of Saline Ice

1975 ◽  
Vol 14 (72) ◽  
pp. 459-465 ◽  
Author(s):  
Bharat Dixit ◽  
E. R. Pounder
Keyword(s):  
Theoretical Model ◽  
Melting Point ◽  
Specific Heat ◽  
Experimental Results ◽  
Temperature Range ◽  
Calorimetric Experiment

A calorimetric experiment was performed to determine empirically the dependence of the specific heat of ice with salinity 0-10‰ over the temperature range from –23° C to the melting point The experimental results agree with the theoretical model determined by Schwerdtfeger (1963) for calculating the specific heat except within several degrees of the melting point and for very pure ice.

scholarly journals Recommending a value for the Newtonian gravitational constant

2014 ◽  
Vol 372 (2026) ◽  
pp. 20140029 ◽  
Author(s):  
Barry M. Wood
Keyword(s):  
Gravitational Constant ◽  
Present Situation ◽  
Primary Objective ◽  
Experimental Results ◽  
Task Group ◽  
Fundamental Constants ◽  
Conversion Factors ◽  
A Value ◽  
Self Consistent ◽  
Newtonian Gravitational Constant

The primary objective of the CODATA Task Group on Fundamental Constants is ‘to periodically provide the scientific and technological communities with a self-consistent set of internationally recommended values of the basic constants and conversion factors of physics and chemistry based on all of the relevant data available at a given point in time’. I discuss why the availability of these recommended values is important and how it simplifies and improves science. I outline the process of determining the recommended values and introduce the principles that are used to deal with discrepant results. In particular, I discuss the specific challenges posed by the present situation of gravitational constant experimental results and how these principles were applied to the most recent 2010 recommended value. Finally, I speculate about what may be expected for the next recommended value of the gravitational constant scheduled for evaluation in 2014.

Fluid Flow Through Randomly Packed Monodisperse Fibers: The Kozeny-Carman Parameter Analysis

1997 ◽  
Vol 119 (1) ◽  
pp. 188-192 ◽  
Author(s):  
O. Rahli ◽  
L. Tadrist ◽  
M. Miscevic ◽  
R. Santini
Keyword(s):  
Fluid Flow ◽  
Experimental Studies ◽  
Theoretical Models ◽  
Experimental Results ◽  
Parameter Analysis ◽  
Flow Through Porous Media ◽  
Aspect Ratios ◽  
A Value ◽  
Flow Through ◽  
Permeability Increase

Experimental studies have been carried out on fluid flow through porous media made up of randomly packed monodisperse fibers. The permeability and the Kozeny-Carman parameter kk are deduced from experimental results. The variations of the permeability increase exponentially with the porosity. The parameter kk is a decreasing function of the porosity ε and tends asymptotically to a value close to that deduced from a modified Ergun relation. The important decrease, observed for small aspect ratios, is certainly an effect of the cut sections of fibers. The results in terms of parameter kk are systematically compared to those deduced from various theoretical models. The variation laws of the parameter kk, deduced from different models, present important discrepancies with our experimental results.

Specific Heat of the Synthetic Rubber Hycar-OR from 15° to 340° K

1943 ◽  
Vol 16 (2) ◽  
pp. 310-317 ◽  
Author(s):  
Norman Bekkedahl ◽  
Russell B. Scott
Keyword(s):  
Heat Equation ◽  
Specific Heat ◽  
Temperature Curve ◽  
Second Order ◽  
Heat Temperature ◽  
A Value ◽  
Synthetic Rubber ◽  
Experimental Values ◽  
Adiabatic Vacuum

Abstract Measurements of specific heat were made on a sample of Hycar-OR synthetic rubber from 15° to 340° K by means of an adiabatic vacuum-type calorimeter. The experimental values of the specific heat between 15° and 22° K were well represented by the Debye specific-heat equation, using a βν value of 80 and, accordingly, the values below 15° K were calculated with this equation. At about 250° K the material has a transition of the second order, the specific heat increasing by about 40 per cent to a value of 1.84 Int. joules · gram−1 · degree−1 just above the transition. From 250° to 340° K the specific heat-temperature curve is nearly linear, and the values can be calculated to within 0.2 per cent from the formula Cp=0.00283T+1.126, in Int. joules · gram−1 · degree−1. At 298.16° K (25° C) the specific heat is 1.971 Int. joules · gram−1 · degree−1 (0.4712 calories · gram−1 · degree−1). The increase in entropy resulting from heating from 0° to 298.16° K was calculated to be 1.743 ± 0.002 Int. joules · gram−1 · degree−1 (0.4167 ± 0.0005 calories · gram−1 · degree−1).

Theoretical specific heat from spin wave in comparison with experimental results in Fe-oxide superconductors

2010 ◽  
Vol 36 (7) ◽  
pp. 618-622
Author(s):  
Li Jun ◽  
Zhang Yu-Feng ◽  
Qin Zhi-Jie ◽  
Niu Xiao-Li ◽  
Li Dong-Sheng ◽  
...  
Keyword(s):  
Specific Heat ◽  
Spin Wave ◽  
Experimental Results ◽  
Oxide Superconductors ◽  
Fe Oxide

Thermodynamic Properties of CMSX-4 Superalloy: Results from the ThermoLab Project

2006 ◽  
Vol 508 ◽  
pp. 591-596 ◽  
Author(s):  
Mauro Palumbo ◽  
Daniele Baldissin ◽  
Livio Battezzati ◽  
O. Tassa ◽  
Rainer Wunderlich ◽  
...  
Keyword(s):  
Thermodynamic Properties ◽  
Specific Heat ◽  
Enthalpy Of Fusion ◽  
Experimental Results ◽  
Thermodynamic Calculations ◽  
Calorimetric Measurements ◽  
Calibration Methods ◽  
Thermocalc Software

This contribution reports the results of calorimetric measurements of the enthalpy of fusion and liquid specific heat carried out in different laboratories as part of the ground campaign of the Thermolab project. Different equipments and calibration methods have been used and critically evaluated. Thermodynamic calculations using the Thermocalc software have been performed and a comparison has been carried out with the experimental results.

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