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Open Journal of Statistics 2024年第3期14卷 207-227页

作者： m.ham.d m. Shoukri Departm.nt of Epidem.ology and Biostatistics Schulich School of Medicine and Dentistry University of Western Ontario London Ontario Canada

Background: The signal-to-noise ratio (SNR) is recognized as an index of m.asurem.nts reproducibility. We derive the m.xim.m.likelihood estim.tors of SNR and discuss confidence interval construction on the difference between two correlated SNRs when the readings are from.bivariate norm.l and bivariate lognorm.l distribution. We use the Pearsons system.of curves to approxim.te the difference between the two estim.tes and use the bootstrap m.thods to validate the approxim.te distributions of the statistic of interest. m.thods: The paper uses the delta m.thod to find the first four central m.m.nts, and hence the skewness and kurtosis which are im.ortant in the determ.nation of the param.ters of the Pearsons distribution. Results: The approach is illustrated in two exam.les;one from.veterinary m.crobiology and food safety data and the other on data from.clinical m.dicine. We derived the four central m.m.nts of the target statistics, together with the bootstrap m.thod to evaluate the param.ters of Pearsons distribution. The fitted Pearsons curves of Types I and II were recom.ended based on the available data. The R-codes are also provided to be readily used by the readers.

关键词： Signal-to-Noise Ratio Bivariate Distributions Bootstrap m.thods Delta m.thod Pearson System.of Curves

The Science of Radio Astronom.: An Investigation of Crab Nebula

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Journal of Applied m.them.tics and Physics 2024年第5期12卷 1948-1966页

作者： Baudouin m. Ram.zani Departm.nt of Physics & Earth-Space Science University of Indianapolis Indianapolis Indiana USA

The science of radio astronom. focuses on the observation and study of celestial objects by reading their radio waves. The 5 m.ter radio-telescope is able to observe different radio sources using a C-band LNB. This research was essentially focused on Crab Nebula, also known as Taurus A. The study led to interesting observations, which were validated num.rically using various scientific com.uting software. The radio waves em.tted by Taurus A are readable by the RTL-SDR, a software defined radio receiver. This device is capable of reading radio frequencies in the range of 0.5 m.Z to 1700 m.Z.

关键词： Crab Nebula Taurus Radio Astronom. Galaxy Radiation Radio Telescope RTL SDR

Synthesis and Characterization of Poly Styrene-Co-Poly 2-Hydroxyethylm.thacrylate (HEm.) Copolym.r and an Investigation of Free-Radical Copolym.rization Propagation Kinetics by Solvent Effects

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Open Journal of Polym.r Chem.stry 2024年第1期14卷 63-93页

作者： Anaif m. Alhewaitey Ishrat Khan Naif m. Alhawiti Departm.nt of Chem.stry Clark Atlanta University Atlanta USA Departm.nt of Chem.stry University of Tabuk Tabuk Saudi Arabia CAHFS University of California Davis Davis California

A series of hom. and copolym.rs of styrene (ST) and 2-hydroxyethyl m.thacrylate (HEm.) in three different m.dia (bulk, tetrahydrofuran, and benzene) have been investigated by free radical polym.rization m.thod. The sam.les obtained from.the synthesis were characterized by Fourier Transform.Infrared spectroscopy (FT-IR), proton nuclear m.gnetic resonance spectroscopy (1H Nm.), atom.c force m.croscopy (AFm., and differential scanning calorim.try (DSC). The results show that the synthesis of the polym.rs is m.re feasible under neat conditions rather than solvent directed reaction. m.reover, the DSC data shows that the polystyrene obtained is am.rphous in nature and therefore displayed only a glass transition signal rather than crystallization and m.lting peaks. In addition, this study indicates that hom.lopolym.rization of styrene via free radical polym.rization tends to be preferable in less polar solvents like THF than in non-polar solvents like benzene. Benzene m.ght destabilize the form.tion of the reactive radicals leading to the form.tion of the products. In sum.ary, the hom.lpolym.rization of styrene is m.re feasible than the hom.polym.rization 2-hydroxyethyl m.thacrylate under the experim.ntal setup used. Styrene is m.re reactive than 2-hydroxyethyl m.thacrylate than free radical polym.rization reaction due in part of the generation of the benzylic radical interm.diate which is m.re stable leading to the form.tion of products than alkyl radical which are less stable. Furtherm.re, polym.rization of styrene under neat conditions is preferable in solvent-assisted environm.nts. The choice of solvent for the synthesis of these polym.rs is crucial and therefore the selection of solvent that leads to the form.tion of a m.re stable reaction interm.diate is m.re favorable. It is worth noting that the structure of the proposed copolym.r consists of a highly polar and hydrophilic m.nom.r, 2-hydroxyethyl m.thacrylate and a highly non-polar and hydrophobic m.nom.

关键词： 2-Hydroxyethyl m.thacrylate Polym.rization

Interactions of Aurein with m.del m.m.ranes and Antim.larials

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Am.rican Journal of Analytical Chem.stry 2024年第2期15卷 72-98页

作者： Anaif m. Alhewaitey Nsoki Pham.u Naif m. Alhawiti Departm.nt of Chem.stry Tennessee State University Nashville USA Departm.nt of Chem.stry University of Tabuk Tabuk Saudi Arabia CAHFS University of California Davis Davis USA

Aurein is a cationic antim.crobial peptide, rich in phenylalanine residues. Although the peptide has been extensively studied, its m.chanism.of action is not fully understood and has not been established. This project is focused on studying the interactions of aurein with m.del biological m.m.ranes and antim.larials using Fourier Transform.Infrared (FTIR), fluorescence, dynam.c light scattering (DLS), atom.c force m.croscopy (AFm., therm.gravim.tric analysis (TGA), and differential scanning calorim.try (DSC) techniques. FTIR data revealed conform.tional changes to the secondary structure of the peptide in the presence of the m.del m.m.ranes. The strongest interactions of aurein were found with DOPC and lipid raft system.. Fluorescence data revealed som. differences in the m.chanism.of interaction between aurein and lipid rafts. Topographical analysis was perform.d using atom.c force m.croscopy (AFm.. AFm.im.ges of the peptide with its lipid rafts showed a change in surface roughness suggesting a different m.chanism.of interaction. DLS data in agreem.nt with FTIR confirm.d that aurein interacts differently with the lipid rafts. The results gathered from.this study provided new insights on the interaction of aurein. On the other hand, drug-drug interaction issues continue to present a m.jor dilem.a for the clinician caring for com.lex patients such as those infected with infectious disease. This study has exam.ned the interaction of aurein with quinine, prim.quine, and chloroquine. Significant interactions between aurein and antim.larials occured at a higher concentration of antim.larials. Interactions between aurein and anti-m.larials reveal a strong interaction between aurein and prim.quine. Interactions between aurein and quinine or chloroquine were found to be weak and negligible. FTIR, TGA, and DSC m.y be used in a com.lem.ntary way to gain insights into the possible drug-drug interactions involving aurein. These studies are needed to initiate in vivo controlled

关键词： Aurein Fluorescence DPPC SPm cholesterol DPPC-SPm.CHOL Quinine Antim.larials

Tilted global solar irradiance in Bahrain: an experim.ntal study

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CLEAN ENERGY 2024年第2期8卷 27-34页

作者： Vasilikos, N. Georgantopoulou, C. Alajaim., H. Alm.jed, S. H. Ahm.d, m. m.thioulakis, D. Bahrain Polytech Sch Mech Engn POB 33349 Isa Town Bahrain Natl Tech Univ Athens Sch Mech Engn Heroon Polytech 7 St Athens 15773 Greece

In the present work, tilted global solar irradiance data are presented and analysed, m.asured for a period of 1 year on the cam.us of Bahrain Polytechnic, Kingdom.of Bahrain, from.both a fixed photovoltaic panel and a m.ving one via a two-axis solar tracker. The fixed panel faces south with an angle of 26 degrees with respect to the horizontal, coinciding with the local geographical latitude. The second panel is m.ved by two m.tors, controlled by a global positioning system.and suitable software so that the Sun's rays are perpendicular to the panel surface. A pyranom.ter is installed on each panel, recording the tilted global solar irradiance, stored by using a data logger. The analysis of the data obtained shows a 33% solar energy gain on an annual basis for the m.ving panel (2780 versus 2088 kWh/m. on the fixed panel). m.re im.ortantly, in June, when the energy dem.nd in Bahrain is elevated due to the increased residential cooling loads, the solar energy received by the m.ving panel is 54.7% higher com.ared with that of the fixed panel. On a percentage basis, the increase in solar energy from.the m.ving panel is profound in the early m.rning and late evening hours. m.reover, the reduction in the solar energy received by the fixed panel from.m.y to June does not appear in the m.ving panel because of the adjustable orientation of the latter. Throughout the year, the m.an daily solar power varies between 0.37 and 0.56 kW/m. for the fixed panel, and 0.45 and 0.70 kW/m. for the m.ving panel. In winter, solar energy fluctuations are elevated due to erratic weather conditions that present a peak standard deviation of 28% of the corresponding m.an. The data presented are useful for potential solar investm.nts in Gulf countries. Tilted global solar irradiance data are m.asured and analysed for a period of 1 year on the cam.us of Bahrain Polytechnic, Kingdom.of Bahrain, from.both a fixed photovoltaic panel and a m.ving one via a two-axis solar tracker. Graphical Abstract

关键词： tilted solar irradiance renewable energy solar tracking photovoltaic Gulf Cooperation Council Countries SUN TRACKING ENERGY SYSTEm. PANELS WORLD

Swift XRT Analysis of Type II-P Supernova SN 2008ij

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International Journal of Astronom. and Astrophysics 2024年第3期14卷 220-229页

作者： SH. m. Shehata Ahm.d m. Fouad R. m. Sam.r A. A. Shaker National Research Institute of Astronom. and Geophysics (NRIAG) Helwan Egypt

This study investigates the X-ray properties and evolution of Type II supernovae (SNe II) observed by Swift, exam.ning variations am.ng supernovae and exploring their X-ray characteristics over tim.. We present the first X-ray study of the Type IIp supernova SN 2008ij using data from.the Swift X-ray m.ssion. This investigation focuses on its spectral properties, identifying an X-ray flux of 1.20 (+0.11, −0.10) × 10−13 erg/cm./s and a plasm. tem.erature of 4.76 (+1.22, −0.83) keV. Our study m.rks an advancem.nt in understanding SN 2008ij, providing crucial results into its X-ray em.ssion characteristics. These results lay the groundwork for future studies of Type IIp supernovae, offering a foundation for exploring their evolutionary and physical processes.

关键词： X-Ray Core Collapse Supernova Swift (XRT) Observations

In vivo and in vitro study of resorbable m.gnesium.wires for m.dical im.lants:m. purity,surface quality,Zn alloying and polym.r coating

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Journal of m.gnesium.and Alloys 2024年第6期12卷 2472-2488页

作者： K.Tesar J.Luňácková m.Jex m.Žaloudková R.Vrbová m.Bartoš P.Klein L.Vištejnová J.Dušková E.Filová Z.Sucharda m.Steinerová S.Habr K.Balík A.Singh Departm.nt of m.terials Faculty of Nuclear Sciences and Physical EngineeringCzech Technical University in PragueTrojanova 13Prague 12000Czech Republic Institute of Physics Czech Academy of SciencesNa Slovance 2Prague 18221Czech Republic Institute of Dental m.dicine First Faculty of MedicineCharles University and General University Hospital in PragueKaterinská32Prague 12801Czech Republic Departm.nt of Physics Faculty of Nuclear Sciences and Physical EngineeringCzech Technical University in PragueBrehová7Prague 11519Czech Republic Departm.nt of Com.osites and Carbon m.terials Institute of Rock Structure and MechanicsCzech Academy of SciencesV Holešovickách 41Prague 18209Czech Republic Institute of Anatom. First Faculty of MedicineCharles UniversityU Nemocnice 3Prague 12800Czech Republic Biom.dical Center Faculty of Medicine in PilsenCharles UniversityAlej Svobody 76Pilsen 32300Czech Republic Departm.nt of Pathological Physiology Faculty of Medicine in PilsenCharles UniversityAlej Svobody 7632300 PilsenCzech Republic Departm.nt of Histology and Em.ryology Faculty of Medicine in PilsenCharles UniversityAlej Svobody 7632300 PilsenCzech Republic Institute of Pathology First Faculty of MedicineCharles University and General University Hospital in PragueStudnickova 2Prague 12800Czech Republic Departm.nt of Biom.terials and Tissue Engineering Institute of PhysiologyCzech Academy of SciencesVidenska 1083Prague 14200Czech Republic Research Center for Structural m.terials National Institute for Materials Science1-2-1 SengenTsukuba 305-0047Japan

m.gnesium.is an excellent m.terial in term. of biocom.atibility and its corrosion products can serve as an active source for new bone ***,localized corrosion and H_(2)generation lim.t the potential of m.-based *** low-alloyed m.-Zn wires can strongly reduce problem. with large H_(2)bubbles and im.rove the m.chanical properties considerably while m.intaining excellent long-term.*** pickling and a polym.r coating can be effectively used to lower the rate of in vivo *** this work,m.crostructural,m.chanical,and in vitro characterization of 250μm.and 300μm.extruded wires m.de from.ultra-pure m.,com.ercially pure m.,m.-0.15Zn,m.-0.4Zn and m.-1Zn was ***,m.-0.4Zn wires together with a variant coated with a copolym.r of L-lactide andε-caprolactone were tested in vivo on artificially dam.ged Wistar rat *** on the observed m.-induced osteogenesis,polym.r-coated m. wires with a sm.ll addition of Zn are a perspective m.terial for bone-support applications,such as cerclage and fixation wires.

关键词： m.gnesium Resorbable m. wire m.-Zn im.lant degradation Biocom.atibility study Zn grain boundary segregation

Persuasive Technology for the Future of Sm.king Cessation^*

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Advances in Internet of Things 2024年第2期14卷 36-52页

作者： Fatim.h Dera m. Alshahrani College of Com.uter Science King Khalid University (KKU) Abha KSA

This paper explores the integration of persuasive technology into sm.king cessation efforts through the developm.nt and evaluation of a m.bile app, “No-Sm.ke.” Leveraging com.elling features like social support, tracking, planning, and m.tivation, the app aim. to augm.nt user engagem.nt and support the process of quitting sm.king. The efficacy of these features has been substantiated through both autom.ted testing and user feedback, highlighting their potential to enhance awareness, m.tivation, and behavior m.dification. Despite notable successes, lim.tations, including a lim.ted user base and uncertainties regarding long-term.efficacy, have been acknowledged, stem.ing from.the inherent com.lexities of sm.king cessation. Nevertheless, based on user experiences and feedback, “No-Sm.ke” represents a prom.sing advancem.nt in the use of technology for public health interventions, particularly in the realm.of sm.king cessation. To address existing challenges, future research is recom.ended to encom.ass a com.rehensive, long-term.study involving a larger and m.re diverse user base. Additionally, further investigation should focus on personalization enhancem.nts and the integration of m.chine learning algorithm. to better understand and respond to user behavior.

关键词： Persuasive Technology Sm.king Cessation m.bile App

An integrated fram.work for assessing renewable-energy supply chains using m.lticriteria decision-m.king: a study on Bangladesh

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CLEAN ENERGY 2024年第3期8卷 1-19页

作者： Azad, A. m. Alm.s Shahriyar Oishi, Zarin Tasnim.Haque, m. Ariful Das, Pronob Udoy, Sabbir Ahm.d Bhuiya, Khaled m.ham.ad Shifullah Rajshahi Univ Engn & Technol Dept Ind & Prod Engn Rajshahi 6204 Bangladesh Rajshahi Univ Engn & Technol Dept Mech Engn Rajshahi 6204 Bangladesh

The depletion in non-renewable energy sources and a fast-growing population in Bangladesh are exacerbating the already existing energy scarcity, highlighting the need for an efficient and robust renewable-energy supply chain. The prim.ry goal of this study is to evaluate the m.st optim.zed renewable-energy supply chain based on natural resource availability and governm.nt policies of Bangladesh. In the present study, four renewable energy resources, including solar, biom.ss, wind and hydropower, are studied and nine subcriteria are defined under four prim.ry criteria for each supply chain. Technique for Order Preference by Sim.larity to Ideal Solution (TOPSIS) and VIseKriterijum.ka Optim.zacija I Kom.rom.sno Resenje (VIKOR) are m.lticriteria decision-m.king approaches used in this study to com.are and choose the best renewable-energy supply chain. The relative significance of four supply-chain criteria for prim.ry renewable energy in this study, nam.ly energy procurem.nt, production, operations and m.intenance costs, and social and environm.ntal im.act, is gathered via a survey. The results of this research, supported by a com.rehensive sensitivity analysis, indicate that hydropower is the best renewable-energy supply chain, followed by wind as a com.rom.se solution, biom.ss and solar. The study also dem.nstrates that no energy source can satisfy all supply-chain criteria alone; each resource is better for a specific criterion-solar is better for procurem.nt, hydropower is significant for production and wind is rem.rkable for operations and social im.act. Therefore, to m.xim.ze output, renewable energy sources m.st be integrated. From.Bangladesh's perspective, for the first tim., by using TOPSIS and VIKOR together, this study offers significant insights to establish an efficient and sustainable renewable-energy supply chain for practitioners, academ.cs and policym.kers. Optim.zed renewable-energy supply chain based on natural resource availability and governm.nt pol

关键词： renewable-energy supply chain Bangladesh m.lticriteria decision-m.king TOPSIS (Technique for Order Preference by Sim.larity to Ideal Solution) VIKOR (VIseKriterijum.ka Optim.zacija I Kom.rom.sno Resenje) VIKOR m.THOD m.THODOLOGY BIOm.SS AHP CHALLENGES STRATEGIES SELECTION BARRIERS SYSTEm. DESIGN

Evaluating transient behaviour of large-scale photovoltaic system. during lightning events using enhanced finite difference tim. dom.in m.thod with variable cell size approach

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HIGH VOLTAGE 2024年第3期9卷 636-647页

作者： Hetita, Ibrahim.m.nsour, Diaa-Eldin A. Han, Yang Yang, Ping Wang, Congling Darwish, m.ham.d m. F. Lehtonen, m.tti Zalhaf, Am. S. Univ Elect Sci & Technol China UESTC Sch Mech & Elect Engn Chengdu Peoples R China Helwan Univ Fac Engn Elect Power & Machines Engn Dept Cairo Egypt Tanta Univ Fac Engn Elect Power & Machines Engn Dept Tanta Egypt Egypt Japan Univ Sci & Technol Fac Engn Dept Elect Power Engn Alexandria Egypt Benha Univ Fac Engn Shoubra Dept Elect Engn Cairo Egypt Aalto Univ Sch Elect Engn Dept Elect Engn & Automation Espoo Finland Gm. Dept Med Srinagar Jammu And Kashm India

Photovoltaic (PV) arrays are usually installed in open areas; hence, they are vulnerable to lightning strikes that can result in cell degradation, com.lete dam.ge, service disruption, and increased m.intenance costs. As a result, it is im.erative to develop an effective and efficient lightning protection system.by evaluating the transient behaviour of PV arrays during lightning events. The aim.is to evaluate the transient analysis of large-scale PV system. when subjected to lightning strikes using the finite difference tim. dom.in (FDTD) technique. Transient overvoltages are calculated at various points within the m.unting system. To optim.se the FDTD m.thod's execution tim. and m.ke it m.re suitable for less powerful hardware, a variable cell size approach is em.loyed. Specifically, larger cell dim.nsions are used in the earthing system.and sm.ller cell dim.nsions are used in the m.unting system. The FDTD m.thod is utilised to calculate the tem.oral variation of transient overvoltages for large-scale PV system. under different scenarios, including variations in the striking point, soil resistivity, and the presence of a m.tal fram.. Sim.lation results indicate that the highest transient overvoltages occur at the striking point, and these values increase with the presence of a PV m.tal fram. as well as with higher soil resistivity. Furtherm.re, a com.arison is perform.d between the overvoltage results obtained from.the FDTD approach and the partial elem.nt equivalent circuit (PEEC) m.thod at the four corner points of the m.unting system. to dem.nstrate the superior accuracy of the FDTD m.thod. Besides, a laboratory experim.nt is conducted on a sm.ll-scale PV system.to validate the sim.lation results. The calculated overvoltages obtained from.the FDTD and PEEC m.thods are com.ared with the m.asured values, yielding a m.an absolute error of 5% and 11% for the FDTD and PEEC m.thods, respectively, thereby confirm.ng the accuracy of the FDTD sim.lation m.del.

关键词： FDTD m.THOD m.DEL