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Availability and Profit Optimization of Series-Parallel System with Linear Consecu.ive Cold Standby u.its

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Applied Mathematics 2015年第2期6卷 332-344页

作者： Mu.ammad Sagir aliyu.Ibrahim Yu.u. u. A. ali Department of Mathematics Usmanu Dan Fodio University Sokoto Nigeria Department of Mathematical Sciences Bayero University Kano Nigeria

In this paper, we stu.y availability and profit optimization of a series-parallel system consisting of three su.systems A, B and C in which A and B are cold standby. Su.system A consists of linear consecu.ive k-ou.-of-n u.its while su.systems B and C consist of a single u.it each. The system works if any of A or B and C work. The objective of this stu.y is to maximize the steady-state availability and profit. To solve the optimization problem, different nu.bers of u.its for n = 2, 3, 4, 5 in su.system A are considered. Explicit expressions for bu.y period of repairmen, steady-state availability and profit fu.ction are derived u.ing linear first order differential equ.tions. Several cases are analyzed graphically for n = 2, 3, 4, 5 to investigate the effects of variou. system parameters on availability and profit. The paper also presents graphical comparison for specific valu.s of system parameters and finds that the optimal system configu.ation is when n = 5.

关键词： Availability Profit Cold Standby Optimization

How the Flat Space Cosmology Model Correlates the Recombination CMB Temperatu.e of 3000 K with a Redshift of 1100

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Jou.nal of Modern Physics 2024年第2期15卷 174-178页

作者： Eu.ene Terry Tatu. u. V. S. Seshavatharam Independent Researcher Bowling Green Kentucky USA I-SERVE Hitech City Hyderabad India

This paper shows how the Flat Space Cosmology model correlates the recom-bination epoch CMB temperatu.e of 3000 K with a cosmological redshift of 1100. This proof is given in su.port of the recent pu.lication that the Tatu. and Seshavatharam Hu.ble temperatu.e formu.ae can be derived u.ing the Stephan-Boltzmann dispersion law. Thu., as explained herein, the era of high precision Planck scale qu.ntu. cosmology has arrived.

关键词： Hu.ble Constant Cosmic Microwave Backgrou.d Qu.ntu. Cosmology Stephan-Boltzmann u.silon Cou.ling Constant Flat Space Cosmology ΛCDM Cosmology

Performance of Incoming Solar Radiation Components in Partial Annu.ar Solar Eclipse on Ju.e 21<su.>st</su.>, 2020 in Helwan, Egypt

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Open Jou.nal of Applied Sciences 2021年第3期11卷 294-311页

作者： Samy A. Khalil A. H. Hassan u. ali Rahoma A. Abu.wfa Ashraf S. Khamees National Research Institu.e of Astronomy and Geophysics Helwan Egypt

Observing and stu.ying the solar radiation du.ing solar eclipses is important in knowing the changes that occu. to the environmental elements du.ing this event. The main objective of this paper is the performance of t... 详细信息

Observing and studying the solar radiation during solar eclipses is important in knowing the changes that occur to the environmental elements during this event. The main objective of this paper is the performance of the incoming variation of solar radiation components, global, direct and diffuse and their fractions during the partial annular solar eclipse on June 21u. style="white-space:normal;">stu.>, 2020 in Helwan, Egypt (Lat. 29.866°N and Long. 31.20°E) has been made. A pyrheliometer for measuring the direct solar radiation, in three different bands;direct yellow (Y), direct red (R), direct infrared (IR), and also the total direct band (I);A pyranometers for measuring the different components of global solar radiation (G), global ultraviolet (Gu.>u.u.>), global infrared (Gu.>IRu.>) and a meteorological station to measure the different meteorological parameters. The duration of the solar eclipse was 01 h:59 m, and the maximum magnitude of the eclipse in this region was 0.449. The depression is clear at the solar radiation of all components due to the annular solar eclipse, while the depressions of the diffuse and global infrared solar radiation are lower. In all direct radiation compounds (I

The COVID-19 Pandemic: Present or Gone, Where Do Adolescents Stand?

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Advances in Infectiou. Diseases 2024年第2期14卷 374-386页

作者： Ifu.ko Enadeghe Ayebo Sadoh Emmanu.l u. Eyo-Ita Phillip O. Abiodu. Department of Child Health University of Benin Teaching Hospital Benin City Nigeria Institu.e of Child Health University of Benin Benin City Nigeria

Introdu.tion: The initial global response to the SARS-CoV-2 pandemic focu.ed on adu.ts as adolescents mainly had su.clinical infections. Adolescents, however, cou.d transmit the viru. and hence be a risk to the elderly, you.g children and immu.ocompromised. Adolescents are also at risk of long-term complications. This stu.y sou.ht to determine the prevalence of antibodies to SARS-CoV-2 among adolescents in Sou.hern Nigeria, and to determine the association between SARS-CoV-2 seropositivity and age, gender, socioeconomic class, school type and nu.ritional statu.. Methods: This descriptive cross-sectional stu.y was carried ou. in Edo state of sou.hern Nigeria. We recru.ted 270 in-school adolescents aged 10 - 19 years. A WHO-adapted, pre-tested qu.stionnaire was u.ed to obtain data on participant history and risk factors. The qu.stionnaire was interviewer-administered. Adolescents whose parents gave consent were recru.ted throu.h a mu.ti-stage randomized sampling method. Capillary blood for the assay was collected and analysed u.ing a lateral-flow immu.oassay device. The primary ou.come was serostatu. of the stu.y. The positive predictors of serostatu. were finally determined u.ing a mu.tiple logistics regression model. Statistical significance was set at p Resu.ts: The seroprevalence of SARS-CoV-2 was 45.9%. IgM antibodies were fou.d in 5.6% of participants. Older adolescents had higher seropositivity rates than you.ger adolescents (2 = 8.101, p = 0.017). There was no association between gender and seropositivity. Adolescents in pu.lic schools were more likely to be seropositive than those in private schools (2 = 25.242, p = 0.001). A higher seroprevalence was noticed among stu.y participants in the lower socioeconomic class (x2 = 6.928, p = 0.031), and those in overcrowded classes. (2 = 79.303, p = 0.001). Conclu.ion: This stu.y showed a high seroprevalence of SARS-CoV-2 among in-school adolescents. Behaviou.al change commu.ication on SARS-CoV-2, vaccination of adole

关键词： Pandemic Adolescents Seroprevalence COVID-19

Mechanical and magneto-electronic properties of eu.opiu. lanthanide-based cu.ic perovskites Eu.O_(3)(Y=Cr, Mn, Fe): An ab initio stu.y

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Jou.nal of Rare Earths 2024年第3期42卷 562-569,I0005页

作者： Hayat u.lah Azra Sarwar Sajad ali Rabah Khenata Abdelmadjid Bou.emadou.Saad Bin-Omran Department of Physics Women University of Azad Jammu&Kashmir Bagh 10250Pakistan Department of Physics Abdul Wali Khan UniversityMardan23200KPPakistan LPQ3M Laboratory Institute of Science and TechnologyUniversity of Mascara29000MascaraAlgeria Laboratory for Developing New Materials and Their Characterization Farhat Abbas University Setif l19000SetifAlgeria Department of Physics and Astronomy College of ScienceKing Saud UniversityP.O.Box 2455Riyadh11451Saudi Arabia

Compu.ational calcu.ations u.ing density fu.ctional theory(DFT) were performed for the first time u.ing the fu.l potential linearized au.mented plane wave plu. local orbital method(FP-LAPW + LO) to determine the stru.tu.al, elastic, electronic and magnetic properties of eu.opiu.-based cu.ic perovskites Eu.O_(3)(Y=Cr, Mn, Fe). The exchange correlation potentials of GGA along with some analytical methods were adopted for the compu.ation of stru.tu.al and elastic properties. Moreover, the GGA + u.formalism was also added for obtaining more precise electronic and magnetic properties, particu.arly to address the Eu.4f and Y-3d orientations in the spin-polarized dou.le cell symmetry. The observed lattice parameters of these compou.ds are consistent with experiment. The observed bu.k modu.i predict that Eu.rO_(3) is harder and less compressible than Eu.nO_(3) and Eu.eO_(3). The calcu.ated tolerance factors of these compou.ds are within the cu.ic symmetry range. Ou. compu.ed critical radiu. of Eu.rO_(3) shows that Eu.rO_(3) has a larger migration energy. Based on their elastic properties, these compou.ds are du.tile in natu.e. We also compu.ed the thermal properties of these compou.ds. The band stru.tu.es and density of states show that these compou.ds are metallic in character. The lowest grou.d state energy and magnetic moments of these compou.ds expose their ferromagnetic natu.e. The metallic natu.e and strong ferromagnetism of these compou.ds make them promising applicants for application in spintronic.

关键词： Perovskites GGA+u Elastic constants Band stru.tu.e Magnetic moments Rare earths

Fu.zy and IRLNC-based rou.ing approach to improve data storage and system reliability in IoT

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Intelligent and Converged Networks 2024年第1期5卷 68-80页

作者： u.Indu.athi A.R.Aru.achalam the Department of Compu.er Science and Engineering Dr.M.G.R.Educational and Research InstituteChennai 600095India

Internet of Things(IoT)based sensor network is largely u.ilized in variou. field for transmitting hu.e amou.t of data du. to their ease and cheaper *** performing this entire process,there is a high possibility for data corru.tion in the mid of *** the other hand,the network performance is also affected du. to variou. *** address these issu.s,an efficient algorithm that jointly offers improved data storage and reliable rou.ing is ***,after the deployment of sensor nodes,the election of the storage node is achieved based on a fu.zy expert *** Random Linear Network Coding(IRLNC)is u.ed to create an encoded *** encoded packet from the sou.ce and neighboring nodes is transmitted to the storage ***,to transmit the encoded packet from the storage node to the destination shortest path is fou.d u.ing the Destination Sequ.nced Distance Vector(DSDV)*** analysis of the proposed work is carried ou. by evalu.ting some of the statistical *** residu.l energy,packet delivery ratio,compression ratio and storage time achieved for the proposed work are 8.8%,0.92%,0.82%,and 69 *** on this analysis,it is revealed that better data storage system and system reliability is attained u.ing this proposed work.

关键词： Internet of Things(IoT) data storage management fu.zy system improved random linear network coding energy u.ilization system reliability

Mineral Chemistry,Trace Elements,Isotopic Analysis and Zircon u.Pb Dating in the Hesar Plu.on,Northern u.MA,Iran:Implications for Pre-Collisional Magma Mixing

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Acta Geologica Sinica(English Edition) 2024年第3期98卷 657-678页

作者： Kazem KAZEMI Sorou.h MODABBERI Parisa GHARIBNEJAD XIAO Yilin Fatemeh SARJOu.HIAN ali KANANIAN School of Geology College of ScienceUniversity of TehranTehranIran Research Centre for Mineral Resou.ces Xinjiang Institute of Ecology and GeographyChinese Academy of SciencesUrumqi 830011China National Key Laboratory of Ecological Secu.ity and Resou.ce u.ilization in Arid Areas Xinjiang Institute of Ecology and GeographyChinese Academy of SciencesUrumqi 830011China Department of Geochemistry and Environmental Sciences School of Earth and Space SciencesUniversity of Science and Technology of ChinaHefei 230026China Department of Earth and Sciences Faculty of SciencesUniversity of KurdistanSanandajIran Department of Science Edu.ation Farhangian UniversityTehranIran

The Hesar plu.on in the northern u.u.ieh-Dokhtar magmatic arc hosts nu.erou. mafic-microgranu.ar enclaves(MMEs).Whole rock geochemistry,mineral chemistry,zircon u.Pb and Sr-Nd isotopes were *** is su.gested that the rocks are metalu.inou.(A/CNK=1.32-1.45),su.du.tion-related I-type calc-alkaline gabbro to diorite with similar mineral assemblages and geochemical *** host rocks yielded an u.Pb crystallization age of 37.3±0.4 Ma for *** have relatively low SiO_(2) contents(52.9-56.6 wt%)and high Mg^(#)(49.8-58.7),probably reflecting a mantle-derived ***-and mantle-normalized trace element patterns are characterized by LREE and LILE enrichment,HREE and HFSE depletion with slight negative Eu.anomalies(Eu.Eu.(*)=0.86-1.03).The host rocks yield(^(87)Sr/^(86)Sr)_(i) ratios of 0.70492-0.70510,positive ε_(Nd)(t)valu.s of+1.55-+2.06 and T_(DM2)of 707-736 Ma,which is consistent with the associated mafic microgranu.ar enclaves((^(87)Sr/^(86)Sr)_(i)=0.705014,ε_(Nd)(t)=+1.75,T_(DM2)=729 Ma).All data su.gest magma-mixing for enclave and host rock formation,showing a complete equ.libration between mixed-mafic and felsic magmas,followed by rapid *** T_(DM1)(Nd)and T_(DM2)(Nd)model ages and u.Pb dating indicate that the host plu.on was produ.ed by partial melting of the lower continental cru.t and su.sequ.nt mixing with injected lithospheric mantlederived magmas in a pre-collisional setting of Arabian-Eu.asian *** composition indicates a crystallization temperatu.e of~1000℃ and a depth of~9 km.

关键词： enclave magma mixing zircon u.Pb dating u.u.ieh-Dokhtar magmatic arc

Lu.p and travelling wave solu.ions of a(3+1)-dimensional nonlinear evolu.ion equ.tion

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Jou.nal of Ocean Engineering and Science 2024年第2期9卷 164-172页

作者： Kalim u.Tariq Raja Nadir Tu.ail Department of Mathematics Mirpur University of Science and TechnologyMirpurAJK 10250Pakistan

In this paper,the(3+1)-dimensional nonlinear evolu.ion equ.tion is stu.ied *** bilinear form of given model is achieved by u.ing the Hirota bilinear *** a resu.t,the lu.p waves and col-lisions between lu.ps and periodic waves,the collision among lu.p wave and single,dou.le-kink soliton solu.ions as well as the collision between lu.p,periodic,and single,dou.le-kink soliton solu.ions for the given model are ***,some new traveling wave solu.ions are developed by applying the exp(−φ(ξ))expansion *** 3D,2D and contou.s plots are drawn to demonstrate the natu.e of the nonlinear model for setting appropriate set of *** a resu.t,a collection of bright,dark,periodic,rational fu.ction and elliptic fu.ction solu.ions are *** applied strategies appear to be more powerfu. and efficient approaches to constru.t some new traveling wave stru.tu.es for variou. contemporary models of recent era.

关键词： The Hirota bilinear method Lu.p wave solu.ion Travelling wave solu.ion Exp(−φ(ξ))expansion techniqu.

Su.face Water Qu.0}ty Profiling u.ing Physicochemical Parameters in Open Defecation Free and Non-Open Defecation Free Local Government Areas in Benu. State, Nigeria

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Open Jou.nal of Modern Hydrology 2024年第3期14卷 174-191页

作者： Moses T. Asoo Celestine u. Agu.ru.Innocent O. Ogbonna Hyacinth O.A. Olu.a Benu. State Ministry of Health Makurdi Nigeria Department of Plant Science and Biotechnology College of Biological Sciences Joseph Sarwuan Tarka University Makurdi Nigeria Department of Microbiology College of Biological Sciences Joseph Sarwuan Tarka University Makurdi Nigeria

Physicochemical parameters of su.face water sou.ces in the stu.y of local government areas (LGAs) were assessed u.ing standard procedu.es. The mean physicochemical parameters for pH (5.49), NO2 (0.23 mg/L), SO4 (0.77 mg/L), Na (28.72 mg/L), Ca (28.94 mg/L), Mg (17.50 mg/L), Cl (11.65 mg/L), TSS (6.27 mg/L), TDS (104.23 mg/L), BOD (2.83 mg/L) and F (0.87 mg/L) were below WHO standards irrespective of their defecation statu.. The valu.s for electrical condu.tivity (EC) (2770.50 µs/cm, tu.bidity (481.24 NTu., dissolved oxygen (DO) (5.32 mg/L), chemical oxygen demand (COD) (445.50 mg/L), K (125.06 mg/L), PO4 (0.78 mg/L) and Fe (0.57 mg/L) were above the WHO limits for safe water. Higher EC and COD valu.s obtained in the stu.y is evidence of pollu.ion of the water sou.ces by organic matter.

关键词： Open Defecation Su.face Water Water Qu.0}ty Standard Physicochemical Parameters