Thermodynamics of Nano-Grain Boundaries

1990 ◽  
Vol 206 ◽  
Author(s):  
Hans J. Fecht
Keyword(s):  
Thermodynamic Properties ◽  
Grain Boundaries ◽  
Free Volume ◽  
Excess Enthalpy ◽  
Excess Entropy ◽  
Volume Ratio ◽  
Nanocrystalline Metals ◽  
Simple Method ◽  
Bimodal Material ◽  
Crystalline Component

ABSTRACTA universal, accurate and simple method is developed to describe the thermodynamic properties of disordered grain boundaries in nanocrystalline metals. Based on a free volume approach at negative pressure of the universal equation of state, the maximum free volume, bulk modulus, specific heat at constant pressure, thermal expansion coefficient, excess enthalpy, excess entropy and free energy of grain boundaries are derived from well-known thermodynamic relationships. Describing nanocrystalline metals as a bimodal material with a grain boundary component and a crystalline component, their thermodynamic properties can then be estimated by appropriate scaling of the boundary-to-volume ratio.

An origin of excess vibrational entropies at grain boundaries in Al, Si and MgO: a first-principles analysis with lattice dynamics

2021 ◽  
Author(s):  
T. Yokoi ◽  
K. Ikawa ◽  
A. Nakamura ◽  
K. Matsunaga
Keyword(s):  
Bond Length ◽  
Grain Boundaries ◽  
First Principles ◽  
Lattice Dynamics ◽  
Excess Entropy ◽  
First Principle ◽  
Length Changes

Excess vibrational entropies are examined by performing first-principle lattice dynamics for grain boundaries in MgO, Al and Si. Bond-length changes are critical for excess entropy, although their bonding nature is originally very different.

Development of a Method for the Prediction of Pressure-Viscosity Coefficients of Lubricating Oils Based on Free-Volume Theory

1989 ◽  
Vol 111 (1) ◽  
pp. 121-128 ◽  
Author(s):  
C. S. Wu ◽  
E. E. Klaus ◽  
J. L. Duda
Keyword(s):  
Free Volume ◽  
Good Accuracy ◽  
Temperature Relationship ◽  
Free Volume Theory ◽  
Simple Method ◽  
Lubricating Oils ◽  
Viscosity Coefficients ◽  
Data Points

A simple method based on free-volume theory to predict the pressure-viscosity coefficients of liquid lubricants has been developed. The method only requires the viscosity-temperature relationship and the viscosity at the temperature of interest. The method provides good accuracy when it was tested for 162 data points for various fluid types over wide ranges of temperature and viscosity.

scholarly journals Verdampfungsgleichgewicht und thermodynamisehe Funktionen des flüssigen Systems Wasser + Essigsäure / Vapour-Liquid. Equilibrium and Thermodynamic Functions of the Liquid System Water + Acetic Acid

1973 ◽  
Vol 28 (10) ◽  
pp. 1740-1742 ◽  
Author(s):  
R. Haase ◽  
M. Pehlke ◽  
K.-H. Dücker
Keyword(s):  
Acetic Acid ◽  
Composition Dependence ◽  
Excess Enthalpy ◽  
Excess Entropy ◽  
Liquid System ◽  
Gibbs Function ◽  
Liquid Equilibrium ◽  
Molar Excess ◽  
C 30 ◽  
System Water

Vapour pressures and vapour compositions of the liquid system water + acetic acid have been measured at 25 °C, 30 °C, 35 °C, 40 °C, and 45 °C in the whole range of compositions. The dimerization of acetic acid in the vapour being taken into account, the molar excess Gibbs function ḠE is derived from the measurements. Earlier measurements of the molar excess enthalpy HE are combined with the -GE values to give the molar excess entropy SE. The “symmetry rule” (Haase, 1951) concerning the composition dependence of ḠE, -HE, and S̄E has been confirmed.

scholarly journals Molecular Binding Ratio of Anti-Factor VIII to Purified Factor VIII.

1977 ◽  
Author(s):  
C.G. Cockburn ◽  
Diana M.L. Reay ◽  
R.M. Hardisty
Keyword(s):  
Factor Viii ◽  
High Surface ◽  
High Surface Area ◽  
Volume Ratio ◽  
Light Chains ◽  
Simple Method ◽  
Coomassie Brilliant Blue ◽  
Molecular Binding ◽  
Agarose Gels ◽  
Coomassie Brilliant

A simple method has been developed for cutting washed FVIII:anti-FVIII immunoprecipitates from agarose gels and applying the SDS-denatured, reduced protein to SDS-polyacrylamide gels. The relative amounts of IgG heavy and light chains and FVIII have been quantitated by recording the areas under the densitometer traces of the Coomassie brilliant blue-stained gels. The results show that approximately 20 molecules of anti-FVIII bind per 200,000 daltons of native FVIII. We conclude from this that the factor VIII subunits hava a high surface-area-to-volume ratio.

Analyzing Boron in 9–12% Chromium Steels Using Atom Probe Tomography

2019 ◽  
Vol 25 (2) ◽  
pp. 462-469 ◽  
Author(s):  
Irina Fedorova ◽  
Flemming Bjerg Grumsen ◽  
John Hald ◽  
Hans-Olof Andrén ◽  
Fang Liu
Keyword(s):  
Grain Boundaries ◽  
Atom Probe Tomography ◽  
Atom Probe ◽  
Specimen Preparation ◽  
Accurate Analysis ◽  
Simple Method ◽  
Metal Borides ◽  
Boron Distribution ◽  
Cr Steels ◽  
Term Creep

AbstractSmall additions of boron can remarkably improve the long-term creep resistance of 9–12% Cr steels. The improvement has been attributed to boron segregation to grain boundaries during quenching, and subsequent boron incorporation into certain families of precipitates during tempering. However, the detailed mechanisms are not yet fully understood. Atom probe tomography (APT) is an excellent technique for gaining insights into boron distribution, however, in order to acquire accurate analysis of boron in 9–12% Cr steels using APT, there are several key challenges. In order to better understand and address these challenges, we developed a novel method for site-specific APT specimen preparation, which enables convenient preparation of specimens containing specifically selected grain boundaries positioned approximately perpendicular to the axis of the APT tip. Additionally, when analyzing boron at boundaries and in carbides (as diluted solute) and borides, a widening of the profile of boron distribution compared to other elements was repeatedly observed. This phenomenon is particularly analyzed and discussed in light of the evaporation field of different elements. Finally, the possible effects of detector dead-time on quantitative analysis of boron in metal borides are discussed. A simple method using 10B correction was used to obtain good quantification.

scholarly journals Silver Nanomaterials for Wound Dressing Applications

Pharmaceutics ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 821 ◽  
Author(s):  
Priya Dharshini Krishnan ◽  
Dominik Banas ◽  
Ramya Devi Durai ◽  
Daniil Kabanov ◽  
Bozena Hosnedlova ◽  
...  
Keyword(s):  
High Surface ◽  
High Surface Area ◽  
Volume Ratio ◽  
Wound Dressings ◽  
Gram Negative Bacteria ◽  
Simple Method ◽  
Thermal Synthesis ◽  
Silver Nanomaterials ◽  
Different Types ◽  
Membrane Immobilization

Silver nanoparticles (AgNPs) have recently become very attractive for the scientific community due to their broad spectrum of applications in the biomedical field. The main advantages of AgNPs include a simple method of synthesis, a simple way to change their morphology and high surface area to volume ratio. Much research has been carried out over the years to evaluate their possible effectivity against microbial organisms. The most important factors which influence the effectivity of AgNPs against microorganisms are the method of their preparation and the type of application. When incorporated into fabric wound dressings and other textiles, AgNPs have shown significant antibacterial activity against both Gram-positive and Gram-negative bacteria and inhibited biofilm formation. In this review, the different routes of synthesizing AgNPs with controlled size and geometry including chemical, green, irradiation and thermal synthesis, as well as the different types of application of AgNPs for wound dressings such as membrane immobilization, topical application, preparation of nanofibers and hydrogels, and the mechanism behind their antimicrobial activity, have been discussed elaborately.

Structure and free volume of 〈110〉 symmetric tilt grain boundaries with the E structural unit

2007 ◽  
Vol 55 (11) ◽  
pp. 3959-3969 ◽  
Author(s):  
M.A. Tschopp ◽  
G.J. Tucker ◽  
D.L. McDowell
Keyword(s):  
Grain Boundaries ◽  
Free Volume ◽  
Structural Unit ◽  
Symmetric Tilt

Effects of the Different Temperature Scales on the Calculation of the Thermodynamic Properties of Water Substance

1969 ◽  
Vol 11 (5) ◽  
pp. 521-525
Author(s):  
M. R. Gibson
Keyword(s):  
Thermodynamic Properties ◽  
Equations Of State ◽  
Simple Method ◽  
Temperature Scales ◽  
Thermodynamic Temperatures ◽  
Water Substance

Attention is drawn to the fact that the derivation of so-called ‘Thermodynamic Temperatures’ by the addition of the quantity, 273·15, to temperatures referred to the IPTS leads to discrepancies in the values of the thermodynamic properties calculated from equations of state by means of the thermodynamic relations. These differences are shown to be significant when compared with the tolerances in the 1963 International Skeleton Tables and a simple method of avoiding this error is described.

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