Accurate Assessment of Joule-Thomson Inversion Temperature at Zero Pressure of Imperfect Gases

2021 ◽  
Vol 11 ◽  
Author(s):  
B. A. Mamedov ◽  
Elif Somuncu
Keyword(s):  
Virial Coefficient ◽  
Accurate Determination ◽  
Fluid Temperature ◽  
New Approach ◽  
Lennard Jones ◽  
Inversion Temperature ◽  
Thomson Coefficient ◽  
Suggested Formula ◽  
Good Agreement

Background: The aim of this work is to propose an approach for estimating the Joule-Thomson coefficient as an important parameter necessary to the study of changes in fluid temperature at a given change in pressure at constant enthalpy. Objective: The analytical approach presented in this work is very appropriate for detailed studies of the Joule-Thomson inversion temperature at zero pressure for arbitrary temperature values. Methods: A new approach is suggested for the accurate determination of the Joule-Thomson inversion temperature at zero pressure using the virial coefficient of the Lennard-Jones (12-6) potential. Results: The usefulness and efficiency of the method are tested by application to various gase Ar, He,Ne,H2,O2,CO2CO,CH4,Xe, Kr,N2 and Air. The results obtained are in good agreement with other approximation and experimental data. Conclusion: The suggested formula enables correct and rapid calculation of the JT inversion temperature at zero pressure.

Theoretical Assessment of Compressibility Factor of Gases by Using Second Virial Coefficient

2018 ◽  
Vol 73 (2) ◽  
pp. 121-125
Author(s):  
Bahtiyar A. Mamedov ◽  
Elif Somuncu ◽  
Iskender M. Askerov
Keyword(s):  
Virial Coefficient ◽  
Second Virial Coefficient ◽  
Compressibility Factor ◽  
Analytical Approximation ◽  
Accurate Evaluation ◽  
Numerical Examples ◽  
Lennard Jones ◽  
Theoretical Assessment ◽  
Good Agreement

AbstractWe present a new analytical approximation for determining the compressibility factor of real gases at various temperature values. This algorithm is suitable for the accurate evaluation of the compressibility factor using the second virial coefficient with a Lennard–Jones (12-6) potential. Numerical examples are presented for the gases H2, N2, He, CO2, CH4 and air, and the results are compared with other studies in the literature. Our results showed good agreement with the data in the literature. The consistency of the results demonstrates the effectiveness of our analytical approximation for real gases.

A New Approach for Determining Joint Stiffness of Bolted Joints

2014 ◽  
Vol 670-671 ◽  
pp. 1041-1044 ◽  
Author(s):  
Xi Wang Wang ◽  
Xiao Yang Li ◽  
Lin Lin Zhang ◽  
Xiao Guang Wang
Keyword(s):  
Accurate Determination ◽  
Joint Stiffness ◽  
Fatigue Loading ◽  
Bolted Joints ◽  
Analytical Models ◽  
Bolted Connection ◽  
New Approach ◽  
Axisymmetric Model ◽  
Force Equilibrium

Joint member stiffness in a bolted connection directly influence the safety of a design in regard to both static and fatigue loading as well as in the prevention of separation in the connection. Thus, the accurate determination of the stiffness is of extreme importance to predict the behavior of bolted assemblies. In this paper, An analytical 3D axisymmetric model of bolted joints is proposed to obtain the joint stiffness of Bolted Joints. Considering many different analytical models have been proposed to calculate the joint stiffness, the expression based force equilibrium can be a easy way to choose the best expression for the joint stiffness as a judgment criteria.

Determination of Subnanosecond Fluorescence Lifetimes with a UHF Television Tuner and a cw or Mode-Locked Laser

1986 ◽  
Vol 40 (5) ◽  
pp. 683-687 ◽  
Author(s):  
Frank V. Bright ◽  
Daniel A. Wilson ◽  
Gary M. Hieftje
Keyword(s):  
High Frequency ◽  
Rhodamine 6G ◽  
Instrument Design ◽  
Fluorescence Lifetimes ◽  
New Approach ◽  
Ion Laser ◽  
Subnanosecond Fluorescence ◽  
Argon Ion ◽  
Good Agreement

An inexpensive ultra-high-frequency (UHF) television tuner and an argon-ion laser are employed for the determination of excited-state lifetimes of a series of common fluorophores. Fluorescence lifetimes are determined in the frequency domain; the results are in good agreement with previously reported values and demonstrate the utility of the new approach for subnanosecond measurements. Binary mixtures of rhodamine 6G and rose bengal can also be resolved with the use of this novel instrument design.

scholarly journals A new approach for modelling variability in residential construction projects

2013 ◽  
Vol 13 (2) ◽  
pp. 83-92 ◽  
Author(s):  
Mehrdad Arashpour ◽  
Ron Wakefield ◽  
Nick Blismas ◽  
EWM Lee
Keyword(s):  
Construction Industry ◽  
Construction Projects ◽  
Accurate Determination ◽  
Weather Conditions ◽  
Completion Rates ◽  
New Approach ◽  
Cycle Times ◽  
Product Delivery ◽  
Standard Practices

The construction industry is plagued by long cycle times caused by variability in the supply chain. Variations or undesirable situations are the result of factors such as non-standard practices, work site accidents, inclement weather conditions and faults in design. This paper uses a new approach for modelling variability in construction by linking relative variability indicators to processes. Mass homebuilding sector was chosen as the scope of the analysis because data is readily available. Numerous simulation experiments were designed by varying size of capacity buffers in front of trade contractors, availability of trade contractors, and level of variability in homebuilding processes. The measurements were shown to lead to an accurate determination of relationships between these factors and production parameters. The variability indicator was found to dramatically affect the tangible performance measures such as home completion rates. This study provides for future analysis of the production homebuilding sector, which may lead to improvements in performance and a faster product delivery to homebuyers. 

The Proton Magnetic Resonance Spectra of some Chlorinated Polycyclodiene Pesticide Metabolites. Rapid Assessment of Stereochemistry

1971 ◽  
Vol 49 (12) ◽  
pp. 1993-2003 ◽  
Author(s):  
J. D. McKinney ◽  
L. H. Keith ◽  
A. Alford ◽  
C. E. Fletcher
Keyword(s):  
Magnetic Resonance ◽  
Accurate Determination ◽  
Rapid Assessment ◽  
Shift Reagent ◽  
Coupling Constant ◽  
Pesticide Metabolites ◽  
Relative Stereochemistry ◽  
Superimposed Signals ◽  
Good Agreement

The rapid and accurate determination of the relative stereochemistry of some postulated chlorinated polycyclodiene pesticide metabolites without excessive dependence on chemical methods is described. Proton assignments were made employing the new nuclear magnetic resonance (n.m.r.) shift reagent, Eu(DPM)3, which effected the separation of superimposed signals in these systems. The assignments based on coupling constant information and requiring spin decoupling equipment are in good agreement with those obtained from the Eu(DPM)3 studies. The data presented establishes the relative stereochemistry of these biologically important compounds and demonstrates the utility of one or both approaches in elucidating their overall structures.

Determination of the flexural stiffness of thin plates from small deflection measurements using optical holography

1982 ◽  
Vol 17 (1) ◽  
pp. 53-61 ◽  
Author(s):  
M J Marchant ◽  
M B Snell
Keyword(s):  
Numerical Method ◽  
Accurate Determination ◽  
Metal Plate ◽  
Thin Plates ◽  
Flexural Stiffness ◽  
Interference Fringes ◽  
Small Deflection ◽  
Stiffness Properties ◽  
Good Agreement

A technique is presented for accurate determination of the flexural stiffness of thin plates using optical holography. Measurements of the interference fringes on thin rhombic plates in anticlastic bending are used to calculate the components of curvature by a simple numerical method Control experiments on a metal plate give good agreement with the results of small deflection bending theory. The method appears ideally suited to the measurement of anisotropic flexural stiffness properties.

scholarly journals Corrections to the Hipparcos proper motions in declination for 807 stars

2008 ◽  
pp. 109-113 ◽  
Author(s):  
G. Damljanovic ◽  
N. Pejovic
Keyword(s):  
Accurate Determination ◽  
Annual Number ◽  
Time Interval ◽  
Proper Motions ◽  
Hipparcos Catalogue ◽  
Time Variations ◽  
Better Than ◽  
Good Agreement

We used the data on latitude variations obtained from observations with 10 classical photographic zenith tubes (PZT) in order to improve the Hipparcos proper motions in declinations ?? for 807 stars. Part of observing programmes, carried out during the last century for the purpose of studying the Earth's rotation, were realized by using PZT instruments. These observations were performed within in the intervals (tens of years) much longer than that of the Hipparcos mission (less than 4 years). In addition, the annual number of observations for every PZT programme star is several hundreds on the average. Though the accuracy of the star coordinates in the Hipparcos Catalogue is by two orders of magnitude better than that of the star coordinates from the PZT observations, the large number of observations performed a much longer time interval makes it possible to correct the Hipparcos proper motions and to improve their accuracy with respect to the accuracy given in the Hipparcos Catalogue. Long term examinations of latitude and time variations were used to form the Earth Orientation Catalogue (EOC-2), aimed at a more accurate determination of positions and proper motions for the stars included. Our method of calculating the corrections of the proper motions in declination from the latitude variations is different from the method used in obtaining the EOC-2 Catalogue. Comparing the results we have established a good agreement between our ?? and the EOC-2 ones for the star sample used in the present paper.

Analytical evaluation of moments of collision-induced scattering with Lennard-Jones (2n-n) potential

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Elif Somuncu ◽  
Melek Gokbulut
Keyword(s):  
Computational Efficiency ◽  
Molecular System ◽  
Analytical Formula ◽  
Analytical Evaluation ◽  
Lennard Jones ◽  
Analytic Expression ◽  
The Moment ◽  
Suggested Formula ◽  
Good Agreement

AbstractIn this work, an analytic expression for the moment of the collision-induced scattering with Lennard-Jones (2n-n) potential, defining the collision induced polarizability of molecules, is presented. It has been demonstrated that this expression gives accurate results for various values of parameters. The proposed analytical formula has been confirmed through comparisons with the results literature. Because of its computational efficiency, the suggested formula is found utility in the collision-induced polarizability in the molecular system. To our knowledge, this paper presents the first approach to the evaluation of the first two moments for collision-induced scattering of molecules by Lennard-Jones (2n-n) potential. The results obtained for the moment of collision-induced scattering for values n = 6 is in good agreement with literature.

scholarly journals A New Approach for the Determination of Benzocaine and Procaine in Pharmaceuticals by Single-Sweep Polarography

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Serhij Plotycya ◽  
Oksana Strontsitska ◽  
Solomiya Pysarevska ◽  
Mykola Blazheyevskiy ◽  
Liliya Dubenska
Keyword(s):  
Quantitative Determination ◽  
Oxidation Products ◽  
Polarographic Reduction ◽  
Polarographic Method ◽  
Experimental Conditions ◽  
New Approach ◽  
Reduction Current ◽  
Product Specifications ◽  
Good Agreement

A new polarographic method for the determination of benzocaine and procaine based on the polarographic reduction of their chemically obtained oxidation products with potassium peroxymonosulfate is developed. Experimental conditions affecting quantitative yield of benzocaine and procaine oxidation products such as рH, oxidation time, reagents’ concentration, and temperature are explored. It is shown that the reduction current changes in a linear fashion (R=0.999) with increasing concentration of anesthetics over a concentration range of 1·10−6 - 5·10−5 mol L−1. The calculated limits of detection (LOD) for benzocaine and procaine are found to be 5.6·10−6 and 6·10−6 mol L−1, respectively. In the present study, quantitative polarographic determination of benzocaine in Farisil tablets and “Septolete Plus” lozenges and procaine in solution for injections is performed. The results of the analysis are in good agreement with the product specifications described in the quality certificates. The possibility of quantitative determination of benzocaine and procaine in pharmaceuticals is confirmed.

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