Approximation of the adsorption heats of hydrogen on transition metals by means of an empirical model

1982 ◽  
Vol 47 (9) ◽  
pp. 2363-2367 ◽  
Author(s):  
Oldřich Štrouf ◽  
Jiří Fusek ◽  
Karel Kuchynka
Keyword(s):  
Thermal Conductivity ◽  
Transition Metals ◽  
Empirical Method ◽  
Heat Of Fusion ◽  
First Order ◽  
Order Polynomial ◽  
Physical Importance ◽  
Adsorption Heats ◽  
Experimental Values ◽  
Pauling Electronegativity

The adsorption heats of hydrogen on transition metals were approximated using a first order polynomial containing variables of basic physical importance, which were determined recently by means of the empirical method of pattern recognition: the heat of fusion, heat of vaporization, Pauling electronegativity, molar thermal conductivity, first and second ionization energies, electrical conductivity, Debye temperature and atomic volume of the metal. The agreement with experimental values is closer than that obtained with the Pauling relation. Values of adsorption heats are predicted for seven transition metals.

Approximation of adsorption heats of carbon monoxide on transition metals by means of an empirical model

1983 ◽  
Vol 48 (10) ◽  
pp. 2735-2739
Author(s):  
Jiří Fusek ◽  
Oldřich Štrouf ◽  
Karel Kuchynka
Keyword(s):  
Carbon Monoxide ◽  
Heat Capacity ◽  
Transition Metals ◽  
Molar Heat Capacity ◽  
Metal Adsorption ◽  
Heat Of Fusion ◽  
Class Structure ◽  
Fundamental Parameters ◽  
Adsorption Heats ◽  
Pauling Electronegativity

The class structure of transition metals chemisorbing carbon monoxide was determined by expressing the following fundamental parameters in the form of functions: The molar heat capacity, the 1st and 2nd ionization energy, the heat of fusion, Pauling electronegativity, the electric conductivity, Debye temperature, the atomic volume of metal. Adsorption heats have been predicted for twelve transition metals.

Statistical method of steepest improvement of response

2018 ◽  
Vol 84 (11) ◽  
pp. 74-87
Author(s):  
V. B. Bokov
Keyword(s):  
Statistical Method ◽  
Linear Model ◽  
Response Prediction ◽  
Initial Experiment ◽  
First Order ◽  
Prediction Response ◽  
Conditional Extremum ◽  
Order Polynomial ◽  
Limiting Values

A new statistical method for response steepest improvement is proposed. This method is based on an initial experiment performed on two-level factorial design and first-order statistical linear model with coded numerical factors and response variables. The factors for the runs of response steepest improvement are estimated from the data of initial experiment and determination of the conditional extremum. Confidence intervals are determined for those factors. The first-order polynomial response function fitted to the data of the initial experiment makes it possible to predict the response of the runs for response steepest improvement. The linear model of the response prediction, as well as the results of the estimation of the parameters of the linear model for the initial experiment and factors for the experiments of the steepest improvement of the response, are used when finding prediction response intervals in these experiments. Kknowledge of the prediction response intervals in the runs of steepest improvement of the response makes it possible to detect the results beyond their limits and to find the limiting values of the factors for which further runs of response steepest improvement become ineffective and a new initial experiment must be carried out.

scholarly journals Thematic Maps for the Variation of Bearing Capacity of Soil Using SPTs and MATLAB

Geosciences ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 329
Author(s):  
Mahdi O. Karkush ◽  
Mahmood D. Ahmed ◽  
Ammar Abdul-Hassan Sheikha ◽  
Ayad Al-Rumaithi
Keyword(s):  
Bearing Capacity ◽  
Mean Squared Error ◽  
Ground Level ◽  
The Other ◽  
Thematic Maps ◽  
First Order ◽  
Squared Error ◽  
Order Polynomial ◽  
Interpolation Polynomials ◽  
Penetration Tests

The current study involves placing 135 boreholes drilled to a depth of 10 m below the existing ground level. Three standard penetration tests (SPT) are performed at depths of 1.5, 6, and 9.5 m for each borehole. To produce thematic maps with coordinates and depths for the bearing capacity variation of the soil, a numerical analysis was conducted using MATLAB software. Despite several-order interpolation polynomials being used to estimate the bearing capacity of soil, the first-order polynomial was the best among the other trials due to its simplicity and fast calculations. Additionally, the root mean squared error (RMSE) was almost the same for the all of the tried models. The results of the study can be summarized by the production of thematic maps showing the variation of the bearing capacity of the soil over the whole area of Al-Basrah city correlated with several depths. The bearing capacity of soil obtained from the suggested first-order polynomial matches well with those calculated from the results of SPTs with a deviation of ±30% at a 95% confidence interval.

Notizen: Quantum Mechanical Calculation of Collision Integrals for HD

1971 ◽  
Vol 26 (11) ◽  
pp. 1926-1928 ◽  
Author(s):  
W. E. Köhler
Keyword(s):  
Scattering Amplitude ◽  
Quantum Mechanical ◽  
Collision Term ◽  
Tensor Polarization ◽  
Collision Integrals ◽  
First Order ◽  
Relaxation Coefficient ◽  
Angular Momenta ◽  
Experimental Values ◽  
Good Agreement

The magnetic Senftleben-Beenakker effect of the viscosity is mainly determined by two collision integrals of the linearized quantum mechanical Waldmann-Snider collision term, viz. by the relaxation coefficient of the tensor polarization of the molecular rotational angular momenta and by the coefficient which couples the friction pressure tensor and the tensor polarization. Starting from a simple nonspherical potential for HD, the scattering amplitude is evaluated analytically in first order distorted wave Born approximation and the two collision integrals are calculated for room temperature. A fairly good agreement with experimental values is found.

scholarly journals The Effect of Magnitude and Direction of Heat Flow on the Thermal Conductivity for Insulation Materials (Glass Wool) by Using Probe Method

2018 ◽  
Vol 7 (4.20) ◽  
pp. 536
Author(s):  
Hussein Humaish ◽  
. .
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Industrial Process ◽  
Glass Wool ◽  
Probe Method ◽  
Heat Power ◽  
Insulation Materials ◽  
Two Samples ◽  
Hot Disk ◽  
Experimental Values

The thermal energy of building is determined by the thermal properties of the materials and how to install these materials in the elements of buildings according to the direction of heat transfer. The effectiveness of thermal insulation (glass wool) is dependent on its thermal conductivity which is varies in different directions of fibers of glass wool. Glass wool is formed of fibers and binders tangled together during the industrial process to provide some elasticity. The experimental values of thermal conductivity of the insulation materials are changed according to magnitude of the heat power and direction of fiber arrangement. The thermal conductivity for insulation materials has been measured by using probe method,  Huekseflux ® TP02 used to measure the thermal conductivity by emit the flow perpendicular and parallel to the fibers of glass wool. Two samples of yellow glass wool (density 68 kg/m3) with dimensions (10 ×10 ×30) cm have been used. Hot Disk bulk isotropic module has been used to evaluate thermal conductivity. TPS source (Hot Disk probe reference: 4922) characterized by a diameter of 14.61 mm has been selected. COMSOL® multiphysics axisymmetric 2D model has been used to follow the axial and the radial directions of the heat transfer. 

scholarly journals Thermal conductivity in dynamics of first-order phase transitions

2010 ◽  
Vol 847 (3-4) ◽  
pp. 253-267 ◽  
Author(s):  
V.V. Skokov ◽  
D.N. Voskresensky
Keyword(s):  
Thermal Conductivity ◽  
Phase Transitions ◽  
First Order ◽  
First Order Phase

scholarly journals Investigation of the novelty of latent functionally thermal fluids as alternative to nanofluids in natural convective flows

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Zoubida Haddad ◽  
Farida Iachachene ◽  
Eiyad Abu-Nada ◽  
Ioan Pop
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Heat Transfer Enhancement ◽  
Volume Fraction ◽  
Heat Of Fusion ◽  
Transfer Enhancement ◽  
Maximum Heat ◽  
Thermal Fluids ◽  
Maximum Heat Transfer ◽  
Wide Range

AbstractThis paper presents a detailed comparison between the latent functionally thermal fluids (LFTFs) and nanofluids in terms of heat transfer enhancement. The problem used to carry the comparison is natural convection in a differentially heated cavity where LFTFs and nanofluids are considered the working fluids. The nanofluid mixture consists of Al2O3 nanoparticles and water, whereas the LFTF mixture consists of a suspension of nanoencapsulated phase change material (NEPCMs) in water. The thermophysical properties of the LFTFs are derived from available experimental data in literature. The NEPCMs consist of n-nonadecane as PCM and poly(styrene-co-methacrylic acid) as shell material for the encapsulation. Finite volume method is used to solve the governing equations of the LFTFs and the nanofluid. The computations covered a wide range of Rayleigh number, 104 ≤ Ra ≤ 107, and nanoparticle volume fraction ranging between 0 and 1.69%. It was found that the LFTFs give substantial heat transfer enhancement compared to nanofluids, where the maximum heat transfer enhancement of 13% was observed over nanofluids. Though the thermal conductivity of LFTFs was 15 times smaller than that of the base fluid, a significant enhancement in thermal conductivity was observed. This enhancement was attributed to the high latent heat of fusion of the LFTFs which increased the energy transport within the cavity and accordingly the thermal conductivity of the LFTFs.

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