Phase change material (PCM) is considered as one of the most effective thermal energy storage (TES) systems to balance energy supply and demand. A key challenge in designing efficient PCM-based TES systems lies in the enhancement of heat transmission during phase transition. This study numerically examines the privilege of employing twisted-fin arrays inside a shell-and-tube latent heat storage unit to improve the solidification performance. The presence of twisted fins contributes to the dominating role of heat conduction by their curved shapes, which restricts the role of natural convection but largely aids the overall heat-transfer process during solidification. The heat-discharge rate of twisted-fin configuration is increased by ∼14 and ∼55% compared to straight fin and no fin configurations—leading to a reduction in the solidification duration by ∼13 and ∼35%, respectively. The solidification front at various times has also been assessed through a detailed parametric study over the fin height, fin pitch number, and fin thickness. Over the range of values assumed, the fin height is the most dominant parameter – increasing the heat-retrieval rate from 10.0 to 11.4 W and decreasing the discharge time from above 3600 to 2880 s by varying the fin height from 2.5 to 7.5 mm.
This Book is intended to be a textbook studied for undergraduate course in financial statistics/ department of Financial Sciences and Banking. This book is designed to be used in semester system. To achieve the goals of the book, it is divided into the following chapters. Chapter one introduces basic concepts. Chapter two devotes to frequency distribution and data representation. Chapter three discusses central tendency measures (all types of means, mode, and median). Chapter four deals with dispersion Measures (standard deviation, variance, and coefficient of variation). Chapter five concerned with correlation and regression analysis. While chapter six concerned with testing Hypotheses (One population mean test, Two "independent" populati
... Show MoreIn this study, we review the ARIMA (p, d, q), the EWMA and the DLM (dynamic linear moodelling) procedures in brief in order to accomdate the ac(autocorrelation) structure of data .We consider the recursive estimation and prediction algorithms based on Bayes and KF (Kalman filtering) techniques for correlated observations.We investigate the effect on the MSE of these procedures and compare them using generated data.
Volumetric chemical adsorption was done in a volumetric apparatus using hydrogen gas at room temperature on eleven platinum catalyst, commercial catalysts (RG-412,RG-402 ,RG-432, RG-451, RG-482, and PS-10) and prepared platinum catalysts with 0.1, 0.2 , 0.45 , and 0.55% by weight of Pt supported with Y-alumina. The results show that the metal crystallite area increases with increasing platinum content. The dispersion and particle size of metal crystallite located between 48.2-96.1% and 3.85-12.72 nm, respectively. For bimetallic catalysts, the hydrogen intake decrease in the following order : Re < Sn < Ir.
The paper contains a theoretical analysis of the interrelation between methodology of economics used by economic researchers and the methodology of scientific research, encouraging readers to think differently about one of the most complicated & controversial subjects.
The analysis begins with the determination of propositions that were discussed and explained in the course of the argument.
1- The economic researcher, like a scientific one, goes after the procedures of physical sciences and benefits of the forms of logic.
2- Economics deals with human behavior while the natural sciences deal with the matter.
3-This similarity a
... Show MoreResumen The article deals with the analysis of different ways of creating Arabic scientific terminology. Arabic scientific style includes the terminology that represents different scientific areas functioning in all Arabic countries. These ways can be classified as: giving the meaning of terms; construction of new terms according to the rules of word formation; reduction and ellipsis of terms; direct term borrowing, all the above-mentioned being subject to further analysis. Main objectives of academic style, the specific features and certain lexical and grammatical peculiarities of the Arabic scientific terminology are under consideration as well. Discussed in the paper are linguistic and extra-linguistic factors influencing the ways of sci
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The quadrupole moment of 14B exotic nucleus has been calculated using configuration mixing shell model with limiting number of orbital's in the model space. The core- polarization effects, are included through a microscopic theory which considers a particle-hole excitations from the core and the model space orbits into the higher orbits with 6ħω excitations using M3Y interaction. The simple harmonic oscillator potential is used to generate the single particle wave functions. Large basis no-core shell model with (0+2)ћω truncation is used for 14B nucleus. The effective charges for the protons and neutrons were calculated su |
