International science review series最新文献

{"title":"Maximum Allowable Pressure Calculation of Water Tube Boiler during Operation","authors":"A. Elmaryami, M. Ahmida, W. Muhammad","doi":"10.47285/isr.v2i3.112","DOIUrl":"https://doi.org/10.47285/isr.v2i3.112","url":null,"abstract":"In the steam boiler industrial sector, pressure and temperature of the water tube are the two main factors that affect the safety and efficiency of a steam boiler.  Explosions may be occurring because of a sudden drop in pressure without a corresponding drop in temperature.  Therefore, understanding the temperature distribution of the water tube boiler is essential to control the failure and explosion of the boiler.  Once the temperature distribution is known than the limiting factors that affect the water tube life such as the maximum allowable pressure can be determined.  ANSYS software will be used to determine the temperature distribution in the water tube of a utility boiler during operation at elevated inlet water and furnace temperature.  The theory of axisymmetric has been utilized since the water- tube is cylindrical in shape.  In axisymmetric theory, a three-dimensional cylindrical problem like a water tube can be reduced to two-dimensional by ignoring the circumferential Ө, while the r-axis and z-axis became x-axis and y-axis or Cartesian coordinate.  Then two-dimensional rectangular elements meshing for the profile cross-section along the water tube in r and z axes were implemented in a computerized simulation using ANSYS 10 to find out the steady-state temperature distribution of the water tube.","PeriodicalId":81558,"journal":{"name":"International science review series","volume":"28 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72415099","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Influence of Hollow Carbon Sphere in Heterogeneous Catalysis","authors":"B. P. Mtolo, V. Vishwanathan","doi":"10.47285/isr.v2i3.110","DOIUrl":"https://doi.org/10.47285/isr.v2i3.110","url":null,"abstract":"Hollow carbon spheres (HCSs) are hollow structured carbon particles of sizes ranging between micron and nanometre sizes with thin outer shells. They are of importance for their unique properties such as encapsulation ability, controllable permeability, surface functionality, high surface-to-volume ratios, and excellent chemical and thermal stabilities. In this communication, a precise description is presented of the synthesis, characterization, and applications of HCSs. Synthesis of HCSs is normally carried out in two ways, namely, hard-templating and soft-templating methods. These materials are characterized by modern techniques to investigate their structural and textural properties to get an insight into the material. Finally, the recent progress made in the applications of HCSs has been reported in the area of catalysis as a support material and energy storage device.","PeriodicalId":81558,"journal":{"name":"International science review series","volume":"73 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90568828","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Review of Well-Known Robust Line Search and Trust Region Numerical Optimization Algorithms for Solving Nonlinear Least-Squares Problems","authors":"Jacques Sabiti Kiseta, Roger Liendi Akumoso","doi":"10.47285/isr.v2i3.106","DOIUrl":"https://doi.org/10.47285/isr.v2i3.106","url":null,"abstract":"The conditional, unconditional, or the exact maximum likelihood estimation and the least-squares estimation involve minimizing either the conditional or the unconditional residual sum of squares. The maximum likelihood estimation (MLE) approach and the nonlinear least squares (NLS) procedure involve an iterative search technique for obtaining global rather than local optimal estimates. Several authors have presented brief overviews of algorithms for solving NLS problems. Snezana S. Djordjevic (2019) presented a review of some unconstrained optimization methods based on the line search techniques. Mahaboob et al. (2017) proposed a different approach to estimate nonlinear regression models using numerical methods also based on the line search techniques. Mohammad, Waziri, and Santos (2019) have briefly reviewed methods for solving NLS problems, paying special attention to the structured quasi-Newton methods which are the family of the search line techniques. Ya-Xiang Yuan (2011) reviewed some recent results on numerical methods for nonlinear equations and NLS problems based on online searches and trust regions techniques, particularly on Levenberg-Marquardt type methods, quasi-Newton type methods, and trust regions algorithms. The purpose of this paper is to review some online searches and trust region's more well-known robust numerical optimization algorithms and the most used in practice for the estimation of time series models and other nonlinear regression models. The line searches algorithms considered are: Gradient algorithm, Steepest Descent (SD) algorithm, Newton-Raphson (NR) algorithm, Murray’s algorithm, Quasi-Newton (QN) algorithm, Gauss-Newton (GN) algorithm, Fletcher and Powell algorithm (FP), Broyden-Fletcher-Goldfarb-Shanno (BFGS) algorithm. While the only trust-region algorithm considered is the Levenberg-Marquardt (LM) algorithm. We also give some main advantages and disadvantages of these different algorithms.","PeriodicalId":81558,"journal":{"name":"International science review series","volume":"19 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86835884","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A New Iterative Algorithm for Estimating Parameters and Orders of Multiple-Input Single-Output Time Series Models","authors":"Jacques Sabiti Kiseta, Emilie Epeka Mbambe, Angèle Yule Sotazo, Roger Akumoso Liendi","doi":"10.47285/isr.v2i2.104","DOIUrl":"https://doi.org/10.47285/isr.v2i2.104","url":null,"abstract":"In this paper, we propose a new iterative algorithm for estimating the parameters and orders of a multiple-input single-output (MISO) time series model. This algorithm is based on a method suggested by Hannan and Rissanen (1982) for estimating an ARMA model. The key is the use of pseudo-linear regression techniques to derive the iterative nonlinear least-squares estimators by using the Gauss-Newton algorithm. Simulation results are presented to compare the new algorithm with the exact maximum likelihood method (EML) and the generalized least squares (GLS) method proposed by Sabiti (1997).","PeriodicalId":81558,"journal":{"name":"International science review series","volume":"16 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81533423","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Fast Algorithm for Estimating Parameters of a Multivariate Autoregressive Moving Average Processes","authors":"Emilie Epeka Mbambe, Angèle Yule Sotazo, Jacques Sabiti Kiseta, Roger Akumoso Liendi","doi":"10.47285/isr.v2i2.103","DOIUrl":"https://doi.org/10.47285/isr.v2i2.103","url":null,"abstract":"We propose in this paper a fast and iterative algorithm for estimating the parameters of a Gaussian vector autoregressive-moving average (VARMA) model. This algorithm is a multivariate generalization of that suggested by Sabiti (1996) for estimating the parameters of a univariate ARMA(p,q) process. It is proposed, mainly for providing initial estimators for the iterative maximization of a log-likelihood function. Comparisons about the number of computations in terms of multiplication operations are made with a method that uses gradients to locate a maximum of the likelihood function and the fast method suggested by Spliid (1983).","PeriodicalId":81558,"journal":{"name":"International science review series","volume":"45 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91379109","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mutual Comparison Studies of Mono and Di Cations in Binary and Ternary Aqueous Electrolytes Solution at 298.15 K","authors":"Y. Akhtar","doi":"10.47285/isr.v2i1.91","DOIUrl":"https://doi.org/10.47285/isr.v2i1.91","url":null,"abstract":"Densities and viscosities of binary and ternary electrolytes solution have been determined experimentally at 298.15 K.  The results obtained from density and viscosity measurement have been used to calculate apparent molar volume φv partial molar volume φov at infinite dilution, relative viscosities hrel, A and B coefficients, and free energies of activation of viscous flow of solvent Δ µ10# and solute Δ µ20. The results are discussed in terms of the dehydration effect of the weak ion-ion and strong ion-solvent interactions. The properties of these systems are discussed in terms of the charge, size, and hydrogen bonding effect.","PeriodicalId":81558,"journal":{"name":"International science review series","volume":"111 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83555919","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Computation of the Exact Fisher Information Matrix of a Multiple Input Single Output Time Series Models","authors":"Emilie Epeka Mbambe, Angèle Yule Sotazo, Jacques Sabiti Kiseta","doi":"10.47285/isr.v2i2.93","DOIUrl":"https://doi.org/10.47285/isr.v2i2.93","url":null,"abstract":"Klein, Mélard, and Zahaf (1998) have proposed the computation of the exact Fisher information matrix of a large class of Gaussian time series models called the single-input-single-output (SISO) model, includes dynamic regression with autocorrelated errors and the transfer function model, with autoregressive moving average errors. For computing the Fisher information matrix of a SISO model, they introduced an algorithm based on a combination of two computational procedures: recursions for the covariance matrix of the derivatives of the state vector with respect to the parameters and the fast Kalman filter recursions used in the evaluation of the likelihood function. In this paper, we propose a generalization of this method for computing the Fisher information matrix of a MISO model.","PeriodicalId":81558,"journal":{"name":"International science review series","volume":"482 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82634303","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"4-Dimensional Relativistic Quantum Mechanical Equilibrium in Gravitational-Electromagnetic Confinements","authors":"Wim Vegt","doi":"10.47285/isr.v1i2.59","DOIUrl":"https://doi.org/10.47285/isr.v1i2.59","url":null,"abstract":"An important milestone in quantum physics was reached by the publication of the Relativistic Quantum Mechanical Dirac Equation in 1928. However, the Dirac equation represents a 1-Dimensional quantum mechanical equation which is unable to describe the 4-Dimensional Physical Reality. \u0000In this article, the 4-Dimensional Relativistic Quantum Mechanical Dirac Equation expressed in the vector probability functions and the complex conjugated vector probability function will be discussed. To realize this, the classical boundaries of physics has to be changed. It is necessary to go back in time more than 200 years ago before the Dirac Equation had been published.\u0000Isaac Newton who published in 1687 in the “Philosophiae Naturalis Principia Mathematica” a Universal Fundamental Principle in Physics was in Harmony with Science and Religion. Newton found the concept of “Universal Equilibrium” which he mentioned in his famous third equation, Action = Reaction. This article presents a New Kind of Physics based on this Universal Fundamental Concept in Physics which results in a New Approach in Quantum Physics and General Relativity.\u0000The physical concept of quantum mechanical probability waves has been originated during the famous 5th Solvay Conference in 1927. During that period there were several circumstances that came together and made it possible to create a unique idea of material waves being complex (partly real and partly imaginary) and describing the probability of the appearance of a physical object (elementary particle). The idea of complex probability waves was new in the beginning of the 20th century. Since then the New Concept has been protected carefully within the Copenhagen Interpretation.   When Schrödinger published his well-known material wave equation in 1926, he found spherical and elliptical solutions for the presence of the electron within the atom. The first idea of the material waves in Schrödinger's wave equation was the concept of confined Electromagnetic Waves. But according to Maxwell, this was impossible. According to Maxwell's equations, Electromagnetic Waves can only propagate along straight lines and it is impossible that Light (Electromagnetic Waves) could confine with the surface of a sphere or an ellipse. For that reason, these material waves in Schrödinger's wave equation could only be of a different origin than Electromagnetic Waves. Niels Bohr introduced the concept of “Probability Waves” as the origin of the material waves in Schrödinger’s wave equation. And defined the New Concept that the electron was still a particle but the physical presence of the electron in the Atom was equally divided by a spherical probability function. \u0000In the New Theory, it will be demonstrated that because of a mistake in the Maxwell Equations, in 1927 Confined Electromagnetic waves could not be considered to be the material waves expressed in Schrödinger's wave equation. The New Theory presents a new equation describing electromagnetic field con","PeriodicalId":81558,"journal":{"name":"International science review series","volume":"4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89113953","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Studies in the politics of environmental protection: the historical roots of the British Clean Air Act, 1956: III. The ripening of public opinion, 1898-1952.","authors":"L. Ashby, M. Anderson","doi":"10.1179/030801877789826277","DOIUrl":"https://doi.org/10.1179/030801877789826277","url":null,"abstract":"AbstractThis is the last of three articles about the campaign to abate smoke in the cities of England which began early in the 19th century and culminated in the Clean Air Act 1956. It describes the third sustained wave of activity by lobbies for smoke abatement and the way the public conscience was raised to a level which made it practicable to bring in laws to control domestic as well as industrial smoke. The impediments to this evolution of public opinion were (a) social: the Englishman's sentimental attachment to an inefficient and wasteful way to heat and cook in his home; (b) technological: the practical difficulties in producing a solid smokeless fuel which could be used in an open grate; and (c) administrative: the difficulties in enforcing laws against smoke when smoke could be neither defined nor measured with the precision necessary in a court of law.","PeriodicalId":81558,"journal":{"name":"International science review series","volume":"2 1","pages":"190-206"},"PeriodicalIF":0.0,"publicationDate":"1977-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1179/030801877789826277","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"65926162","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}