scholarly journals Determination of Molecular Diameter by PVT

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Vahid Moeini ◽  
Mehri Deilam
Keyword(s):  
Experimental Data ◽  
Potential Energy ◽  
Internal Pressure ◽  
Potential Function ◽  
Supercritical Fluids ◽  
Accurate Calculation ◽  
Dense Fluids ◽  
Lennard Jones ◽  
The Relationship

We derive an equation for calculation of molecular diameter of dense fluids, with using simultaneous Lennard-Jones (12-6) potential function and the internal pressure results. Considering the internal pressure by modeling the average configurational potential energy and then taking its derivative with respect to volume to a minimum point of potential energy has been shown that molecular diameter is function of the resultant of the forces of attraction and the forces of repulsion between the molecules in a fluid. The regularity is tested with experimental data for 10 fluids including Ar, N2, CO, CO2, CH4, C2H6, C3H8, C4H10, C6H6, and C6H5CH3. These problems have led us to try to establish a function for the accurate calculation of the molecular diameter based on the internal pressure theory for different fluids. The relationship appears to hold both compressed liquids and dense supercritical fluids.

Equation of State of Dense Fluids. IX. Comparison of the Internal Pressure from the PY Theory and the Lennard‐Jones (7–28) Potential with Experimental Data on CF4

1972 ◽  
Vol 56 (11) ◽  
pp. 5732-5733
Author(s):  
Stephen C. Glover ◽  
Mirion Y. Bearman ◽  
Richard J. Bearman ◽  
Frederic Mandei
Keyword(s):  
Experimental Data ◽  
Equation Of State ◽  
Internal Pressure ◽  
Dense Fluids ◽  
Lennard Jones

UNITED ATOM MODEL APPROACH FOR DESCRIBING C60 INTERACTION ENERGY IN MOLECULAR MECHANICS

2011 ◽  
Vol 10 (04) ◽  
pp. 423-434 ◽  
Author(s):  
TEIK-CHENG LIM
Keyword(s):  
Potential Energy ◽  
Computational Chemistry ◽  
Interaction Energy ◽  
Molecular Mechanics ◽  
Potential Function ◽  
Van Der Waals ◽  
Lennard Jones ◽  
Atom Model ◽  
Model Approach

A unified atom model for describing interaction energy between C60 molecules was obtained by Liu and Wang based on the Smith–Thakkar potential function. In view of the mathematical resemblance between the Liu–Wang and the conventional Lennard-Jones (12-6) function (used in computational chemistry software for describing van der Waals energy), modified versions of the Lennard-Jones function are proposed for quantifying the potential energy between C60 molecules. In this way, the Liu–Wang parameters can be converted into Lennard-Jones parameters for ready execution in commercially available computational chemistry software with minimal hard-coding involved. It was found that the Lennard-Jones function reasonably approximates the Liu–Wang model when the former's indices are increased by a factor of (7/4), without introducing any change to the coefficients. A better agreement was found when m = 4n = 35.4857, which also requires the change in repulsive and attractive indices from 1 and 2 to (1/3) and (4/3), respectively.

Intensification of foam technology by the energy of the electrohydrothermal force field. Part 1. Analysis of the features of generating internal pressure in the foam mass when electric current energy is introduced into it

2020 ◽  
pp. 56-58
Author(s):  
V. N. Sokov
Keyword(s):  
Experimental Data ◽  
Potential Energy ◽  
Force Field ◽  
Internal Pressure ◽  
Electric Current ◽  
Electronic Component ◽  
Complex Action ◽  
Temperature And Pressure ◽  
Current Energy ◽  
Excess Internal Pressure

A concept has been put forward about the potential energy inherent in the nature of the foam system to self-compact under the complex action of an electrohydrothermal force field on it. The generation of excess internal pressure in the foam system was studied analytically and experimentally. Experimental data on monitoring the dynamics of temperature and pressure were obtained using a computer and a modern electronic component base. The method inherent in the technology allows combining a number of processes in one operation: compaction of the refractory components of the mixture, removal of shrinkage moisture, stamping of any profile of a lightweight product, providing clear edges that do not require grinding and trimming of products.

Extending the linear range for kinetic reactions by considering the relationship between enzyme activity of the reagent and measurement intervals.

1986 ◽  
Vol 32 (11) ◽  
pp. 2021-2025 ◽  
Author(s):  
M P Goren ◽  
J E Davis
Keyword(s):  
Experimental Data ◽  
Enzyme Activity ◽  
Linear Range ◽  
Concentration Curve ◽  
Measurement Interval ◽  
Km Value ◽  
The Relationship ◽  
Substrate Concentrations ◽  
Selection Of

Abstract We show that the rate-concentration curve is sigmoidal for enzyme-catalyzed procedures that are commonly applied to rapid automated analyzers. Linear data can be obtained by judicious selection of the reagent enzyme activity (Vm) and the measurement interval (t1 to t2). For determination of substrate concentrations much less than Km, conditions that balance linearity with sensitivity and accuracy are obtained when Vm/Km = [ln (t2/t1)]/(t2-t1). We also present theoretical and experimental data that show the linear range can be extended to concentrations exceeding the Km value. We illustrate the application of theoretically appropriate conditions by analysis of procedures reported to be optimized. Familiarity with these concepts can obviate laborious and potentially misleading experimentation.

scholarly journals Изучение взаимосвязи главных напряжений при разрушении морского льда

2020 ◽  
Author(s):  
A.I. Mamontov ◽  
M.V. Kitaev ◽  
O.E. Surov ◽  
V.V. Novikov
Keyword(s):  
Experimental Data ◽  
Potential Energy ◽  
Sea Ice ◽  
Research Method ◽  
Lateral Compression ◽  
Natural Conditions ◽  
Special Equipment ◽  
Laboratory Conditions ◽  
Relationship Of ◽  
The Relationship

Статья посвящена исследованию прочности морского льда. Методом исследования является сброс треугольного индентора (треугольный стальной клин) на поверхность морского льда, предварительно очищенную от верхнего слоя. Для измерения давления, потенциальная энергия индентора до сброса вычисляется расчетным способом, а глубина отпечатка после падения измеряется экспериментально. Экспериментальные данные собирались в разные годы. Температура льда во время проведения экспериментов была различной. В 2018г температура льда была -5С. В 2019 году температура льда была -1С. Сброс индентора производился с разных высот. В результате эксперимента установлена взаимосвязь главных напряжений. При небольшом боковом сжатии льда, давление при котором лед разрушается существенно возрастает. Особенностью этой работы является то, что эксперимент проводился в естественных условиях в одной из бухт г.Владивостока на расстоянии 200 метров от береговой линии, сброс индентора производился на очищенный морской лед. Этот метод исследования проще, чем сжатие образцов льда в лабораторных условиях, так как в последнем случае требуется специальное оборудование и трудоемкая организация проведения опытов.The article is devoted to the study of the strength of sea ice. The research method is the discharge of a triangular indenter (triangular steel wedge) onto the surface of sea ice, previously cleaned from the upper layer. To measure the pressure, the potential energy of the indenter before discharge is calculated, and the imprint depth after falling is measured experimentally. Experimental data were collected in different years. The temperature of the ice during the experiments was different. In 2018, the ice temperature was -5 С. In 2019, the ice temperature was -1 C. The indenter was reset from different heights. As a result of the experiment, the relationship of the main stresses was established. With a small lateral compression of ice, the pressure at which the ice is destroyed increases significantly. A feature of this work is that the experiment was conducted under natural conditions in one of the bays of Vladivostok at a distance of 200 meters from the coastline, the indenter was discharged onto purified sea ice. This research method is simpler than compressing ice samples under laboratory conditions, since in the latter case special equipment and labor-intensive organization of experiments are required.

Potential Energy as Design Criterion in Planar Multistable Mechanisms

2021 ◽  
Author(s):  
Edward J. Dold ◽  
Philip A. Voglewede
Keyword(s):  
Potential Energy ◽  
Design Process ◽  
Compliant Mechanism ◽  
Equations Of Motion ◽  
Design Criterion ◽  
Energy Curve ◽  
Lagrange’S Equation ◽  
Generalized Force ◽  
The Relationship

Abstract Toggle mechanisms are used throughout engineering to accomplish various tasks, for example residential electrical switching. The design of toggle mechanisms can be broken into three categories: determination of a topology, geometric parameterization, and optimization. While topological determination and optimization have well established processes for use in design, geometric parameterization which includes defining link lengths and spring stiffness has largely been left to engineering judgement. This paper presents a design methodology using potential energy graphs which informs the engineering decisions made in choosing mechanism parameters, giving designers higher confidence in the design. A kinematic analysis coupled with Lagrange’s equation determines the relationship between the mechanism parameters and the potential energy curve. Plotting the potential energy with respect to the generalized coordinate yields a graph with a slope that is the generalized force or moment. The relationships between parameters and their effects on the mechanism are difficult to observe in the equations of motion, but potential energy plots readily provide information pertinent to the design of toggle mechanisms and decouple their effects. The plots also allow design by position rather than time which makes the design process faster. The design process is applied to three examples: a simple toggle mechanism, a compliant mechanism, and a reconfigurable mechanism to show the nuances of the approach.

scholarly journals Datasets for the Determination of Evaporative Flux from Distilled Water and Saturated Brine Using Bench-Scale Atmospheric Simulators

Data ◽  
2021 ◽  
Vol 7 (1) ◽  
pp. 1
Author(s):  
Jared Suchan ◽  
Shahid Azam
Keyword(s):  
Experimental Data ◽  
Saline Water ◽  
Distilled Water ◽  
Canadian Prairies ◽  
Bench Scale ◽  
Evaporative Flux ◽  
Improved Design ◽  
The Relationship ◽  
Empirical Field

Evaporation from fresh water and saline water is critical for the estimation of water budget in the Canadian Prairies. Predictive models using empirical field-based data are subject to significant errors and uncertainty. Therefore, highly controlled test conditions and accurately measured experimental data are required to understand the relationship between atmospheric variables at water surfaces. This paper provides a comprehensive dataset generated for the determination of evaporative flux from distilled water and saturated brine using the bench-scale atmospheric simulator (BAS) and the subsequently improved design (BAS2). Analyses of the weather scenarios from atmospheric parameters and evaporative flux from the experimental data are provided.

Thromboplastin Related Differences in the Determination of International Normalised Ratio: A Cause for Concern?

1994 ◽  
Vol 72 (03) ◽  
pp. 426-429 ◽  
Author(s):  
S Kitchen ◽  
I D Walker ◽  
T A L Woods ◽  
F E Preston
Keyword(s):  
Patient Management ◽  
External Quality Assessment ◽  
Oral Anticoagulant Therapy ◽  
Warfarin Dosage ◽  
External Quality ◽  
External Quality Assessment Scheme ◽  
International Normalised Ratio ◽  
The Uk ◽  
The Relationship

SummaryWhen the International Normalised Ratio (INR) is used for control of oral anticoagulant therapy the same result should be obtained irrespective of the laboratory reagent used. However, in the UK National External Quality Assessment Scheme (NEQAS) for Blood Coagulation INRs determined using different reagents have been significantly different.For 18 NEQAS samples Manchester Reagent (MR) was associated with significantly lower INRs than those obtained using Diagen Activated (DA, p = 0.0004) or Instrumentation Laboratory PT-Fib HS (IL, p = 0.0001). Mean INRs for this group were 3.15, 3.61, and 3.65 for MR, DA, and IL respectively. For 61 fresh samples from warfarin-ised patients with INRs of greater than 3.0 the relationship between thromboplastins in respect of INR was similar to that observed for NEQAS data. Thus INRs obtained with MR were significantly lower than with DA or IL (p <0.0001). Mean INRs for this group were 4.01, 4.40, and 4.59 for MR, DA, and IL respectively.We conclude that the differences between INRs measured with the thromboplastins studied here are sufficiently great to influence patient management through warfarin dosage schedules, particularly in the upper therapeutic range of INR. There is clearly a need to address the issues responsible for the observed discrepancies.

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