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Published By Scientific Research Initiative

2693-0315

2021 ◽  
Vol 2 (3) ◽  
pp. 27-33
Author(s):  
Abdlmanam Elmaryami ◽  
Mahmoud Abdelrazek Ahmida ◽  
Walid Saleh Muhammad

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.


2021 ◽  
Vol 2 (3) ◽  
pp. 18-26
Author(s):  
Bonakele Patricia Mtolo ◽  
Venkataraman Vishwanathan

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.


2021 ◽  
Vol 2 (3) ◽  
pp. 1-17
Author(s):  
Jacques SABITI KISETA ◽  
Roger LIENDI AKUMOSO

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.


2021 ◽  
Vol 2 (2) ◽  
pp. 1-11
Author(s):  
Emilie EPEKA MBAMBE ◽  
Angèle YULE SOTAZO ◽  
Jacques SABITI KISETA

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.


2021 ◽  
Vol 2 (1) ◽  
pp. 30-36
Author(s):  
Yasmin Akhtar

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.


2021 ◽  
Vol 2 (1) ◽  
pp. 1-6
Author(s):  
Dr. Adam Hassan Elhaj Yousif ◽  
Nosaiba Abdalgadir Nusr Mohammed

The present study is aimed to synthesize V2O5 using V(ORi)3 precursor and study its anti-microbial activity. The V(ORi)3 was prepared by reaction of VCl3 and isopropanol alcohol. The synthesized V(ORi)3 was hydrolyzed to yield black V(OH)3 gel using concentrated HCl as gelling agent. Yellow V2O5 obtained by thermal treatment of V(OH)3 gel at110oC and 380oC. All products were characterized using FT-IR Spectroscopy method. IR spectral revealed to found V(ORi)3, V(OH)3 gel and V2O5 were formed. The V2O5 has been tested in vitro against numbers of microorganisms, to assess their antimicrobial activity using disc diffusion method, according to the National Committee for Clinical Laboratory Standards Guidelines. The results showed that V2O5 is active against Staphylococcus aureus and Pseudomonas aeruginosa and partial active against Bacillus subtilis, Escherichia coli    and Candida albicans. Antimicrobial Study of VO(OR)3 is required.


2020 ◽  
Vol 1 (2) ◽  
pp. 34-61
Author(s):  
Wim Vegt

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. In 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. Isaac 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. The 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. In 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 configurations which are also solutions of the Schrodinger's wave equation and the relativistic quantum mechanical Dirac Equation and carry mass, electric charge, and magnetic spin at discrete values.


2020 ◽  
Vol 1 (2) ◽  
pp. 25-33
Author(s):  
Alison Annet Kinengyere ◽  
Haruna Hussein ◽  
Richard Ssenono ◽  
Rehema Chande Mallya

While African health sciences librarians’ role as expert searchers is widely recognized, they have much more to contribute to supporting the development and conduct of systematic reviews. Research evidence has indicated that the librarians rarely participate in the development and conduct of systematic reviews because they are either not called upon to be part, or do not have the skills to participate. Moreover, few librarians who have participated are from outside Africa. Keeping this in mind, the Network of African Medical Librarians (NAML) conducted a pre-AHILA Conference training workshop to introduce participants, specifically the librarians, to the systematic review process. The regional conference for health librarians took place in Ibadan, Nigeria from 14-18 October 2019. This paper evaluates the impact of training of African health sciences librarians in the conduct of systematic reviews. Participants' evaluation feedback was collected using pre and post-training surveys. A mixed-method was employed to gather and analyze both quantitative and qualitative data. The results indicated that the main barriers to librarians’ participation in systematic reviews were lack of skills due to insufficient training and lack of time. This paper is expected to encourage the librarians to advocate for further skills development, in addition to their normal information searching roles. Their participation in the systematic review process would make them, not just relevant but dependable collaborators of systematic review teams, as they participate in improving systematic review reporting.


2020 ◽  
Vol 1 (2) ◽  
pp. 12-24
Author(s):  
Onan Mulumba ◽  
Alison Annet Kinengyere

The Essential Electronic Agricultural Library (TEEAL) and the Access to Global Online Research in Agriculture (AGORA) are key information support programs in learning, teaching, and research. They provide access to relevant scientific evidence, in agriculture and related sciences. While AGORA was introduced in Uganda in 2005, TEEAL was introduced earlier as a “Library in a Box” and later as LAN-TEEAL. With the recent increase in acquisition of TEEAL sets at a number of academic and research institutions in Uganda and with the TEEAL and AGORA campaigns through the training organized under the Information Training and Outreach Center for Africa (ITOCA), it is not clear how TEEAL has impacted on Agricultural research and on the usage of AGORA as an online program in Uganda. The aim of his paper was to explore how TEEAL is used compared to its counterpart, AGORA. The key question to this study relates to respondents’ preference among the two programs and the underlying reasons. An online questionnaire was used to gather responses regarding preference and use of the two programs by students, academics, librarians, IT specialists, and researchers at the various institutions in Uganda. The study was informed by a review of literature from related studies. Findings from 59 respondents indicate that all (100%) the respondents had an idea of TEEAL while for AGORA it was 58 (98.3%) respondents. Of the respondents, 52.5% preferred TEEAL to AGORA because it required no internet access, although the majority believed that AGORA was more important than TEEAL, due to the coverage of more relevant online scientific literature. The most prominent challenges to TEEAL and AGORA were network failures and slow internet, respectively. TEEAL and AGORA were both acknowledged to be very vital resources for academic and research institutions in Uganda. TEEAL mainly had one advantage over AGORA and that is being an offline resource that can be used in institutions with unreliable and inadequate internet. AGORA was also found to have an advantage over TEEAL in that it had a wider content coverage. The most common strategy for improving the use of both programs, as stated by the respondents, was increasing awareness through training and marketing. It was thus recommended that the program hosts utilize the results of this study to improve the utilization of these vital agricultural databases through further training and awareness. It was also recommended that institutions be advised to strengthen their IT infrastructure to support the programs and ensure effective use, for increasing their academic and research output.


2020 ◽  
Vol 1 (2) ◽  
pp. 1-11
Author(s):  
Adam Farah ◽  
Siddig A. N. Tota

The present study is aimed to screen the phytochemicals analysis and elements content of Datura innoxia seeds and leaves. The aqueous and methanol extracts were carried out by using the maceration method and soxhlet apparatus, respectively. Results of the study of Phytochemical screening revealed the presence of a high concentration of alkaloids, flavonoids, tannins, steroids and triterpines, and low concentration of saponin and coummarins. The elements in the leaves and seeds (K, Ca, S, Si, Cl, Fe, Al, P, Mg, Ti, Mn, Zn, Sr, Cu, V, Br, and Zr) were determined by energy-dispersive X-ray fluorescence (EDXRF) spectroscopy. K content was the highest in seeds (5.469 ± 0.021%), Ca and S the highest in leaves (2.461 ± 0.019 %, 1.254 ± 0.022 %, respectively). The elements Ti, Mn, Sr, V, Br, and Zr were detected in the leaves with range concentration 0.062-0.002 %. The elements Si, Cl, Fe, Al, P, Mg, and Zn concentration in seeds varied from 0.002 to 0.942% and in leaves varied from 0.014 to 0.346%. The concentration of these elements did not exceed the standard of dangerous toxic levels.


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