检索结果-南通市图书馆

Physical and geometrical parameters of CVBs XIV:the two nearby systems HIP 19206 and HIP 84425

Research in Astronomy and Astrophysics 2021年第7期21卷 62-70页

作者： Mashhoor A.Al-Wardat Enas Abu-Alrob Abdallah M.Hussein Mohammad K.Mardini Ali A.Taani hatem s.widyan Zahraa T.Yousef Hamid M.Al-Naimiy Nihad A.Yusuf Department of Applied Physics and Astronomy University of SharjahSharjahUAE sharjah Academy for Astronomy Space Science and TechnologySharjahUAE Department of Physics Al al-Bayt UniversityMafraq25113 Jordan Key Lab of Optical Astronomy National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China Physics Department Faculty of ScienceAl-Balqa Applied University19117 SaltJordan Department of Applied Physics Faculty of Science and TechnologyUniversiti Kebangsaan Malaysia43600 UKM BangiSelangorMalaysia Department of Physics Yarmouk UniversityIrbid21163Jordan

Data release 2(DR2) from the Gaia mission was of great help in precise determination of fundamental parameters of Close Visual Binary and Multiple systems(CVBMss), especially masses of their components, which are crucial parameters in understanding formation and evolution of stars and galaxies. This article presents the complete set of fundamental parameters for two nearby close visual binary systems(CVBss), which are HIP 19206 and HIP 84425. We utilised a combination of two methods;the first one is Tokovinin's dynamical method to solve the orbit of the system and to estimate orbital elements and the dynamical mass sum, and the second one is Al-Wardat's method for analysing CVBMss to estimate the physical parameters of the individual components. The latest method employs grids of Kurucz lineblanketed plane parallel model atmospheres to build synthetic spectral Energy Distributions(sEDs) of the individual components. Trigonometric parallax measurements given by Gaia DR2 and Hipparcos catalogues are used to analyse the two systems. The difference in these measurements yielded slight discrepancies in the fundamental parameters of the individual components, especially masses. so, a new dynamical parallax is suggested in this work based on the most convenient mass sum as given by each of the two methods. The new dynamical parallax for the system HIP 19205 of 22.97±0.95 mas coincides well with the trigonometric one reported recently(in December 2020) by Gaia EDR3 of 22.3689 ± 0.4056 mas. The positions of the components of the two systems on the evolutionary tracks and isochrones are plotted, which suggest that all components are solar-type main sequence stars. Their most probable formation and evolution scenarios are also discussed.

关键词： binaries:close binaries:visual-stars:fundamental parameters stars:individual:HIP 19206 and HIP 84425

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Physical and orbital properties of the stellar system HIP 43766

引用

Research in Astronomy and Astrophysics 2021年第5期21卷 84-90页

作者： hatem widyan Hussam Aljboor Department of Physics Al al-Bayt UniversityMafraq 25113Jordan

In this paper,we present the analysis of the stellar binary system HIP 43766 to determine its *** rely on dynamical modeling and atmospheric modeling with recent data to determine the orbital solution and the physical properties of the *** is a consistency between observed and synthetic photometry obtained using atmospheric *** calculated dynamical mass sum of the system ranged between 1.691 and 2.609 solar masses,while it ranges between 2.0 and 2.1 as estimated utilizing atmospheric *** could be due to inaccuracy in estimating the orbit,which could be modified with future observations with more relative positional *** parameters of the system and the position of the components on the evolutionary tracks show that the system consists of F5 and G5 subgiant stars,mostly formed by fragmentation.A dynamical mass sum is predicted for the system.

关键词： stars:binaries:close stars:binaries:visual stars:individual:HIP 43766

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Time-Dependent Action in φ~6 Potential

引用

理论物理通讯：英文版 2012年第7期58卷 19-26页

作者： hatem widyan Mashhoor Al-Wardat Department of Physics Al al-Bayt University Physics Department Yarmouk University

The false vacuum decay in field theory from a coherently oscillating initial state is studied for φ6 potential. An oscillating bubble solution is obtained. The instantaneous bubble nucleation rate is calculated.

关键词：时间变化初始状态泡沫溶液场理论成核率振荡

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Prevelance of Bovine Cysticercosis in Egypt and the Cysticidal Effect of Two Extracts Obtained from Balanites aegyptiaca and Moringa oleifera on Mice Model Affected with T. saginata Cysticerci

引用

Open Journal of Animal sciences 2024年第2期14卷 39-55页

作者： Omnia M. Kandil Noha M. F. Hassan Doaa sedky hatem A. shalaby Heba M. Ashry Nadia M. T. Abu El Ezz sahar M. Kandeel Mohamed s. Abdelfattah L. Ying Ebtesam M. Al-Olayan Parasitology and Animal Diseases Department Veterinary Research Institute National Research Centre Dokki Cairo Egypt Chemistry of Natural Compounds Department Pharmaceutical and Drugs Industries Research Institute National Research Centre Dokki Cairo Egypt Chemistry Department Faculty of Science Helwan University Cairo Egypt state Key Laboratory of Plateau Ecology and Agriculture Qinghai University Xining China College of Agriculture and Animal Husbandry Qinghai University Xining China Department of Zoology Collage of Science King Saud University Riyadh Saudi Arabia

The aim of the present study was to determine the prevalence of bovine cysticercosis in both cattle and buffloas, in Egypt and to assess the cysticidal efficacy of Balanites aegyptiaca fruits (B. aegyptiaca) and Moringa oleifera seeds (M. oleifera) extracts in experimentally infected mice. The study detected the level of tumor necrosis factor (TNF-α) to monitor the immune and inflammatory responses of experimentally infected mice. Through meat inspection, a total number of 2125 male bovine, 2 to 5 years old, (1125 cattle and 1000 buffloes) were examined under the authority of Albsatine and Alwaraq official abattoirs in Cairo Governorate, Egypt covering the period extended from March 2022 to April 2023. The overall prevalence of the disease among bovine was 7.8% (6.31% of cattle and 9.5% of buffloes). Besides, B. aegyptiaca and M. oleifera extracts showed cysticidal activity in experimentally infected mice. A decrease in the numbers of cysticerci was found in all treated mice groups, and up to 88% reduction was achieved in the B. aegyptiaca-treated group;higher than that was recorded in both M. oleifera (72.23%) and albendazole-treated ones (80.56%). Postmortem findings proved that M. oleifera and B. aegyptiaca reduced cysticerci numbers comparable to a commercial anthelmintic. The study showed a significant decrease (P 0.001) in TNF-α levels after treatment with Balanites and Moringa extracts, compared with the untreated control and the albendazole-treated groups.

关键词： Prevalence Balanites aegyptiaca Moringa oleifera Mice T. saginata Cysticerci

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

solar Energy Harvesting Using a Timer-Based Relay selection

引用

Computers, Materials & Continua 2023年第1期74卷 2149-2159页

作者： Raed Alhamad hatem Boujemaa Information Technology Department Saudi Electronic UniversityRiyadhSaudi Arabia UCAR-sUPCOM-COsIM Ariana2083Tunisia

In this paper,the throughput and delay of cooperative communications are derived when solar energy is used and relay node is selected using a *** source and relays harvest energy from sun using a photo voltaic *** harvested power is used by the source to transmit data to the ***,a selected relay amplifies the signal to the ***,partial and reactive relay selection are *** relay transmits when its timer *** timer is set to a value proportional to the inverse of its signal to Noise Ratio(sNR).Therefore,the relay with largest sNR will transmit first and its signal will be detected by the other relays that will remain idle to avoid *** duration is optimized to maximize the ***’s waiting time and total delay are also *** also derive the statistics of sNR when solar energy is *** harvested power from sun is proportional to the sum of a deterministic radiation intensity and a random attenuation due to weather effects and clouds *** fixed radiation intensity depends on season,month and time t in *** throughput of cooperative communications with energy harvesting from sun was not yet studied.

关键词： solar energy harvesting timer based relay selection relaying techniques throughput and delay analysis

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

skin lesion classification system using a Knearest neighbor algorithm

引用

Visual Computing for Industry,Biomedicine,and Art 2022年第1期5卷 78-87页

作者： Mustafa Qays hatem Renewable Energy Department Technical Institute of BaqubahMiddle Technical UniversityDyala 32001Iraq

One of the most critical steps in medical health is the proper diagnosis of the *** is one of the most volatile and challenging fields in terms of *** often require further testing,review of the patient’s history,and other data to ensure a proper ***,finding a method that can guarantee a proper trusted diagnosis quickly is *** approaches have been developed over the years to facilitate the diagnosis based on machine ***,the developed systems lack certain properties,such as high *** study proposes a system developed in MATLAB that can identify skin lesions and classify them as normal or *** classification process is effectuated by implementing the K-nearest neighbor(KNN)approach to differentiate between normal skin and malignant skin lesions that imply *** is used because it is time efficient and promises highly accurate *** accuracy of the system reached 98%in classifying skin lesions.

关键词： Machine learning skin disease K-nearest neighbor skin detection MATLAB Graphical user interface

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

An Eco-Friendly Approach for Reducing Carbon Emissions in Cloud Data Centers

引用

Computers, Materials & Continua 2022年第8期72卷 3175-3193页

作者： Mohammad Aldossary hatem A.Alharbi Department of Computer science College of Arts and SciencePrince Sattam bin Abdulaziz UniversityAl-KharjSaudi Arabia Department of Computer Engineering College of Computer Science and EngineeringTaibah UniversityMadinahSaudi Arabia

Based on the saudi Green initiative,which aims to improve the Kingdom’s environmental status and reduce the carbon emission of more than 278 million tons by 2030 along with a promising plan to achieve netzero carbon by 2060,NEOM city has been proposed to be the“saudi hub”for green energy,since NEOM is estimated to generate up to 120 Gigawatts(GW)of renewable energy by ***,the Information and Communication Technology(ICT)sector is considered a key contributor to global energy consumption and carbon *** data centers are estimated to consume about 13%of the overall global electricity demand by ***,reducing the total carbon emissions of the ICT sector plays a vital factor in achieving the saudi plan to minimize global carbon ***,this paper aims to propose an eco-friendly approach using a Mixed-Integer Linear Programming(MILP)model to reduce the carbon emissions associated with ICT infrastructure in saudi *** approach considers the saudi National Fiber Network(sNFN)as the backbone of saudi Internet ***,we compare two different scenarios of data center *** first scenario considers a traditional cloud data center located in Jeddah and Riyadh,whereas the second scenario considers NEOM as a potential cloud data center new location to take advantage of its green energy ***,we calculate the energy consumption and carbon emissions of cloud data centers and their associated energy *** that,we optimize the energy efficiency of different cloud data centers’locations(in the sNFN)to reduce the associated carbon emissions and energy *** results show that the proposed approach can save up to 94%of the carbon emissions and 62%of the energy cost compared to the current cloud physical *** savings are achieved due to the shifting of cloud data centers from cities that have conventional energy sources to a city that has rich in renewable energy ***,we

关键词： Cloud computing carbon emissions energy efficiency energy consumption energy costs eco-friendly data center

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Impact of different nano additives on performance, combustion, emissions and exergetic analysis of a diesel engine using waste cooking oil biodiesel

引用

Propulsion and Power Research 2022年第2期11卷 209-223页

作者： M.s.Gad Mostafa M.Abdel Aziz hatem Kayed Mechanical Engineering Department Faculty of EngineeringFayoum UniversityEgypt Mechanical Engineering Department Institute of Aviation Engineering and TechnologyGizaEgypt Mechanical Power Engineering Department Faculty of EngineeringCairo University12613Egypt

Biodiesel is derived from waste cooking oil (WCO) by transesterification. Methylester was prepared by mixing diesel and biodiesel oils as 20% by volume. Nano particles asTiO2, Al2O3 and CNTs were blended with biodiesel blend at different concentrations of 25,50, and 100 mg/l to enhance the physicochemical fuel characteristics to obtain clean and effi-cient combustion performance. An experimental setup was incorporated into a diesel engine toinvestigate the influence of these nano-materials on engine performance, exergy analysis, combustion characteristics and emissions using WCO biodiesel-diesel mixture. Enriching methylester mixture with 100 ppm titanium, alumina and CNTs (B20T100, B20A100 andB20C100) increased the thermal efficiency by 4%, 6% and 11.5%, respectively compared toB20. Biodiesel blending with nano additives B20T100, B20A100 and B20C100 decreasedthe emissions of CO (11%, 24% and 30%, respectively), HC (8%, 17% and 25%, respectively)and smoke (10%, 13% and 19%, respectively) compared to B20. However, the noticeable increase of NOx was estimated by 5%, 12% and 27% for B20T100, B20A100 and B20C100,respectively. Finally, the results showed the rise in peak cylinder pressure by 5%, 9% and 11% and increase in heat release rate by 4%, 8% and 13% for B20T100, B20A100 andB20C100, respectively. The fuel exergy of B20T100, B20A100 and B20C100 are lower thanbiodiesel blend B20 by 6.5%, 16% and 23% but the exergetic efficiency are increased by 7%,19% and 30% at full load about B20.

关键词： Waste cooking oil(WCO) Nano additives Engine performance Exergy Combustion characteristics Emissions

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Performance,emissions and exergy analyses of adding CNTs to various biodiesel feedstocks

引用

Propulsion and Power Research 2022年第4期11卷 511-526页

Extraction of biodiesel from waste cooking oil,jatropha,and corn oils is done by *** and biodiesel were blended at 20%volume ratio to make methyl *** doses of 25,50,and 100 mg/l,carbon nanotubes(CNTs)was mixed with biodiesel *** objective of the present research is to examine experimentally a diesel engine performance,combustion characteristics,exergy and emissions analyses with inclusion of nano additive to various methyl ester *** ester blend is enriched with CNTs as JB20C100,WB20C100 and CB20C100 where the improvements in thermal efficiency are raised about biodiesel mixture by 9%,13%and 15%,*** of 100 ppm of CNTs to biodiesel blends achieves the greatest reductions in CO(14%,22%and 30%),HC(16%,20%and 25%),and smoke emissions(15%,19%and 23%)for JB20C100,WB20C100 and CB20C100,*** comparing with B20,blending 100 ppm CNTs with JB20,CB20,and WB20 obtained the highest increases in cylinder pressure of 3%,5%,and 10%,as well as the highest increases in heat release of 4%,7%,and 11%,*** downside of CNTs addition achieves a rise in NOx emissions by 10%,17%,and 22%for JB20C100,WB20C100,and CB20C100,*** efficiency increases by 8%,19%,and 24%for B20T100,B20A100,and B20C100,*** index improvements achieve 1.5%,5%and 6.5%,for B20T100,B20A100,and B20C100,***20 with CNTs of 100 ppm is highly recommended for improving engine performance,combustion,and exergy characteristics with considerable emissions reduction.

关键词： Biodiesel Carbon nanotubes(CNTs) Engine performance Exergy Combustion characteristics Emissions

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

strength-ductility synergy in a 1.4 GPa austenitic steel with a heterogeneous lamellar microstructure

引用

Journal of Materials science & Technology 2022年第11期106卷 133-138页

作者： Gang Niu hatem s.Zurob R.D.K.Misra Huibin Wu Yu Zou Department of Materials science and Engineering University of TorontoTorontoONM5S 3E4Canada Collaborative Innovation Center of Steel TechnologyUniversity of Science and Technology BeijingBeijing 100083China Department of Materials science and Engineering McMaster UniversityHamiltonONL8S 4L7Canada Department of Metallurgical Materials and Biomedical EngineeringUniversity of Texas at El PasoEl PasoTX 79968USA Collaborative Innovation Center of steel Technology University of Science and Technology BeijingBeijing 100083China Department of Materials science and Engineering University of TorontoTorontoONM5S 3E4Canada

*** Advanced high-strength steels with good ductility are essen-tial to the manufacturing,structural safety,and light-weighting of load-bearing structures in many industries[1-3].Austenitic stain-less steel(Ass)exhibits high ductility due to the TRIP and/or TWIP effect that can alleviate stress concentration,prevent void nucle-ation,enhance work hardening,and postpone necking[4-6].The yield strength of conventional Ass is generally low(∼200-500 MPa),and their deformation resistance is insufficient for many load-bearing applications[6].Previous studies reported the in-creased yield strength in various austenitic steels through grain refinement,dislocation strengthening,precipitation strengthening,and heterogeneous hardening[7-14].A single strengthening mech-anism,however,is typically insufficient to obtain ultrahigh yield strength over 1 GPa in austenitic steel[12].

关键词： steel ductility austenitic

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：