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集成相变储热材料的光伏/热复合系统性能分析

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发电技术 2023年第1期44卷 53-62页

作者： abd.hamid Mohamed 夏龙禹魏高升崔柳徐超杜小泽电站能量传递转化与系统教育部重点实验室(华北电力大学) 北京市昌平区102206

将相变材料(phase change material,PCM)与光伏/热(photovoltaic/thermal,PV/T)模块集成,可通过提高冷却能力改善光伏面板的发电效率,同时利用PCM存储热能并合理利用。在2种集成相变储热材料的PV/T模块设计基础上,采用数值模拟方法进行... 详细信息

将相变材料(phase change material,PCM)与光伏/热(photovoltaic/thermal,PV/T)模块集成,可通过提高冷却能力改善光伏面板的发电效率,同时利用PCM存储热能并合理利用。在2种集成相变储热材料的PV/T模块设计基础上,采用数值模拟方法进行性能分析,并与传统PV/T装置进行比较。从能量和(火用)2方面对集成系统的整体性能进行分析,并研究冷却工质流量的影响。结果表明,将相变储热材料与PV/T模块集成可显著提高系统的整体性能。其中集成2种相变储热材料的PV/T系统的日总能量效率和总(火用)效率最高,分别为67.65%和12.86%,每日可提供的能量最高可达3603.2 W·h/m2。随着冷却工质体积流量的增加,总能量效率略有提高,但总(火用)效率显著下降。

关键词：相变储热光伏/热(PV/T) (火用)效率太阳能

Daily number of bee louse （Braula coeca） in honey bee （Apis mellifera carnica and A. m. syriaca） colonies maintained under semi-arid conditions

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Insect Science 2008年第6期15卷 563-567页

作者： Shahera Zaitoun abd Al-Majeed Al-Ghzawi Department of Plant Production and Protection Faculty of Agricultural Technology AI-Balqa' Applied University Al-Salt Department of Plant Production Faculty of Agriculture Jordan University of Science and Technology Irbid 22110 Jordan

Experimental work was conducted at two apiaries located in Irbid district and in Shuna North, Jordan, during the years 2004-2006. The aims of these investigations were to estimate the seasonal changes in the infestation rates of the bee louse （Braula sp.） and to develop an easy and rapid method of estimating the infestation rate on workers with bee Braula. Two major honey bee subspecies are reared in Jordan; Apis mellifera carnica and Apis mellifera syriaca were used in this study. The results showed that the infestation rate began to increase rapidly in May, reaching the season＇s maximum rate of 16.2%, 15.8% and 17.4% forA. m. carnica and 22.6%, 23.9% and 22.9% forA. m. syriaca in December of 2004, 2005 and 2006, respectively. The maximum adult numbers of bees were found in April and June, whereas the minimum for the year was in January in both honey bee subspecies colonies during the study period. The actual population of the bee louse could be estimated by counting the daily dropped lice and multiplying by a factor of 158. This factor is valid for the experimental colonies of both subspecies kept for 3 years under semi-arid Mediterranean conditions.

关键词： Apis mellifera carnica Apis mellifera syriaca Braula honeybee Jordan

Design of a Microcontroller-Based Data Acquisition System for Ground Weather Observations: Evaluation of Radio Refractivity of Air

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International Journal of Communications, Network and System Sciences 2014年第9期7卷 355-364页

作者： Amar Adane Ania Ali Yahia Essaid Mameri abd-El-hamid Adane Laboratory of Image Processing and Radiation U.S.T.H.B. Algiers Algeria

A meteorological data acquisition system is built using a PIC16F877A microcontroller and electric output-based sensors. This system is programmed in C language using the PCWH compiler. It is smart, accurate, cheap, small, light and easily movable. It is designed to automatically get instantaneous measurements of air temperature, atmospheric pressure, and relative humidity. Depending on their utilisation, these measurements are collected with repetition rate tuneable from one minute to one hour. They are displayed on LCD screen and transferred to a personal computer where they are stored and processed. As an application, such data are recorded in situ and used to estimate the radio refractivity of air near the ground in real time. This parameter is necessary to account for the propagation of radiofrequency waves through the lower atmosphere, during wireless transmissions.

关键词： Microcontroller Sensors C Programming Meteorology Radio Refractivity

The Impact of Firm Characteristics, Industry Types, and Financial Ratios on SMEs＇ Utilization of Tax Incentives

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Journal of Modern Accounting and Auditing 2012年第6期8卷 749-763页

作者： Nadiah abd.hamid Rohaya Md Noor Mustaffa Mohamed Zain Barjoyai Bardai Universiti Teknologi MARA Malaysia Malaysian Chamber for Certified Professional Malaysia

This study aims to contribute to the growing literature on issues of tax incentives for small and medium-sized enterprises （SMEs）. Through comprehensive exploration of data, the study investigates factors leading to successful and unsuccessful utilization of tax incentives among SMEs. Financial ratios were calculated based on the information retrieved from the companies＇ annual financial statement. Apparently, these financial ratios are evidence of how successful the companies are in utilizing the tax incentives. In this study, 129 small companies and 71 medium-sized companies were selected as samples for the period of 2003-2007. The result indicates that financial structure such as retained earnings, tax burden, cash flow, and inventory level determined the ability of companies to utilize tax incentives; hence leading to higher earnings generated from the business operation. The age of the companies affects the utilization of tax incentives and this denotes that older companies are more capable of generating higher earnings. Hence, a thorough analysis of the data allows us not only to determine the success of the company in utilizing tax incentives but also to identify the determinants that impact their performance.

关键词： tax incentives small and medium-sized enterprises (SMEs) manufacturing sector economic goal

Utilizing Social Media Data Analytics to Enhance Banking Services

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Intelligent Information Management 2022年第1期14卷 1-14页

作者： Mohamed abd El-hamid Farag Ahmed Askar Amal Elsayed Aboutabl Amr Galal Business Information Systems Faculty of Commerce and Business Administration Helwan University Cairo Egypt Faculty of Computers and Artificial Intelligence Helwan University Cairo Egypt Faculty of Commerce and Business Administration Helwan University Cairo Egypt

The two most important challenges facing banks today are attracting new customers and retaining their existing ones. Research shows that 30 percent of banks cited customer loyalty as their biggest challenges. Thus, given that customer loyalty is completely connected to customer delight. The challenging question is: How do banks achieve customer delight by making every interaction a pleasant experience? In our viewpoint “The key is to stop treating customers as segments and personalize all customer interactions and services which can be achieved by using the latest technological advancements in Big Data Analytics, Artificial Intelligence (AI) and Machine Learning”. With the rapidly increasing usage of social media like Facebook, Twitter, LinkedIn, and Instagram, business organizations are now moving towards adapting this technology to drive business advantages. This research will explore the power of social media and how it can be used by banks to provide an edge over their competitors by providing improved products and services to their customers thereby making their experience easy and responsive. It also proposes a framework for social media analytics and its important components to address all the technical and business aspects of the retail and online banking, however, what customer expects from this medium and what banks offer to them needs to be widely studied and understood.

关键词： Natural Language Processing (NLP) Sentiment Analysis Social Banking Information Retrieval (IR) Social Media Analytics

Investigation on the performance of DI-BSCCO superconducting electric motor

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Natural Science 2011年第1期3卷 36-41页

作者： Chin Kat Meng Nasri A. hamid Mohd. Yusri abd. Rahman 不详

Superconducting electrical devices have been developed in various fields especially in industrial energy over a decade. Superconducting motor is one of the electrical devices that attracted the attention of engineers and researchers from the universities and industries due to its distinctive energy efficiency. This paper describes the performance of superconducting electric motor and its performance was compared with conventional copper electric motor. Direct current (DC) synchronous single- phase series motor has been chosen as the base for development of both motors. Two prototypes of electric motor fabricated using conventional copper coil and superconducting coil were developed with similar motor type, design, dimension, and features. The superconducting motor coil was wound using Bi-2223 (DI-BSCCO) Type H wires developed by Sumitomo Electric Industries Limited, Japan. A finite element analysis was performed to get a clear view on flux plots of the magnetic induction. Features of the superconducting motor and the special coil frame designed to protect the superconducting wire was also presented in this paper. In addition, the torque performances for both types of motor were measured. The superconducting electric motor was found to consume lower power to produce the same output compared with the conventional copper-wound motor.

关键词： Superconductor Magnetic flux Finite Element Analysis Electric Motor

Tin stearate organometallic precursor prepared SnO_2 quantum dots nanopowder for aqueous- and non-aqueous medium photocatalytic hydrogen gas evolution

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Journal of Energy Chemistry 2016年第4期25卷 691-701页

作者： Choonyian Haw Weesiong Chiu Noor Hamizah Khanis Saadah abdul Rahman Poisim Khiew Shahidan Radiman Roslan abd-Shukor Muhammad Azmi abdul hamid Low Dimensional Materials Research Centre Department of PhysicsUniversity of Malaya Department of Chemical Engineering Faculty of EngineeringUniversity of Nottingham Malaysia CampusJalan Broga School of Applied Physics Faculty of Science and TechnologyNational University of Malaysia

Current study reports a rapid one-pot non-hydrolytic condition in the synthesis of Sn O2QDs nanopowder using tin(II) stearate(Sn(St)2) as environmentally-benign organometallic precursor,which is an unprecedentedly employed-compound in preceding Sn O2nanopowder *** as-synthesized Sn O2QDs that are hydrophobic can be easily transferred from organic solvent to aqueous solution through a robust ligand exchange *** stearate-capping ligands on the surface of QDs can be replaced by beta-cyclodextrin(β-CD) and eventually render the QDs highly water soluble,which ultimately make it exhibit bi-functionality for different liquid medium *** characterizations reveal that the bi-functional QDs are indeed well-matched with the standard rutile Sn O2cassiterite phase without the presence of any *** QDs can be interchangeably used as photocatalyst for both aqueous and non-aqueous phase,where it shows significant enhancement of hydrogen gas production as compared to that of commercial Sn O2nanopowder.

关键词： SnO2 Tinstearate Precursors Ligand exchange Photocatalyst Hydrogen gas production

Timed Intercourse versus Intrauterine Insemination with Mild Ovarian Stimulation for Unexplained Infertility

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Open Journal of Obstetrics and Gynecology 2022年第12期12卷 1279-1288页

作者： Hany Mahmoud abd El hamid Manal abdel-Wanees Alsayed Hesham Mohammed Hamed Shaimaa Belal Department of Obstetrics and Gynecology El-Sahel Teaching Hospital Cairo Egypt Department of Obstetrics and Gynecology Faculty of Medicine Helwan University Helwan Egypt

Background: Infertility is unexplained in about 22% - 28% of infertile couples. Spontaneous pregnancy may occur in them. If did not happen, Expectant management will be via clomiphene citrate (CC) administration, intrauterine insemination (IUI), and IVF & ICSI. Aim: to assess the effectiveness of intrauterine insemination with mild controlled ovarian stimulation compared with expectant management in couples with unexplained infertility more than one year. Methods: 160 couples with unexplained infertility were selected, The couples were randomly divided into two groups: Group (A) “80 couples”: Intrauterine insemination (IUI) with mild controlled ovarian stimulation (combination of CC + hMG) using prepared semen and was performed 36 hours after hCG injection, Group (B) “80 couples”: Couples had no ovulation induction. They encouraged for timed intercourse in the most fertile days of female cycle guided by folliculometry for 6 months. Data were collected quantitatively, coded and analyzed using SPSS. The power of study is 80% and 95% confidence interval. Result: The pregnancy rate was calculated in both groups: In group (A) (IUI/COS): OPR (Ongoing pregnancy rates) was 27.5% and PR (pregnancy rates)/cycle was 8.6%. In group (B) (Expectant management): OPR was 25% and PR/cycle was 5.3%. Conclusion: Mild controlled ovarian stimulation CC + hMG with IUI offers no statistical significance in terms of pregnancy outcomes over expectant management in this study however significance in the response to stimulation.

关键词： Intrauterine Insemination Ovarian Stimulation Unexplained Infertility

Effect of Using Baker＇s Yeast and Exogenous Digestive Enzymes as Growth Promoters on Growth, Feed Utilization and Hematological Indices of Nile tilapia, Oreochromis niloticus Fingerlings

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Journal of Agricultural Science and Technology(B) 2012年第1期2卷 15-28页

作者： Ashraf Mohamed abdelsamee Goda Hafez abdel-hamid Hassan Mabrouk Mohamed abd EI-hamid Wafa Tarek Mohamed E1-Afifi National Institute of Oceanography and Fisheries （NIOF） Fish Nutrition Laboratory Cairo 24135 Egypt Regional Center for Foods and feeds Agriculture Research Center Ministry of Agriculture Cairo 24135 Egypt

The present study was conducted to evaluate the effect of baker yeast, Saccharomyces cerevisiae （SC） and exogenous digestive enzymes （pepsin, papain and a-amylase, EDE） dietary supplementation on growth performance, feed utilization and hematological indices of Nile tilapia, Oreochromis niloticus fingerlings. A total of 630 Nile tilapia fingerlings with an average body weight of 26.4 ± 0.2 g were divided in the seven experimental net-pen treatments （three replicates each）. The experiment was conducted for 119 days. Seven isonitrogenous （26.50%） digestible protein and isocaloric （13.40 MJ kgl） digestible energy experimental diets were formulated. The control diet had no SC and EDE added. Diets 2-3 each contained SC at levels of 2 and 4 g 100 g diet-t, respectively, while diets 4-5 each contained EDE at levels of （0.64, 1.28, 0.16） and （1.28, 2.56, 0.32） g 100 gdiefI of pepsin, papain and a-amylase, respectively. Diet 6 contained mixture of SC and EDE at levels of 1 g yeast and 0.32, 0.64, 0.08 g of pepsin, papain and a-amylase, respectively 100 gdiet1 and diet D7 contained 2 g yeast and 0.64, 1.28, 0.16 g of pepsin, papain and a-amylase, respectively 100 g dietl. Growth performance and feed utilization efficiency of Nile tilapia were significantly （P 〈 0.05） higher in all treatments receiving SC and/or EDE supplemented-diets than the control diet which suggests that the addition of SC and EDE enhanced the growth performance. Red blood cells counts, hematocrit and hemoglobin were significantly （P 〈 0.05） highest in all treatments receiving mixture of SC and EDE supplemented-diets （D6 ＋ D7）. The same trend was observed for total plasma protein and total plasma globulin levels. The results of present study suggested that Nile tilapia fingerlings fed diets containing the mixture of I g yeast, SC and 0.32, 0.64, 0.08 g of pepsin, papain and a-amylase, respectively 100 gdiet^-1, for 119 days had enhanced growth performance, diet utilization efficiency and hematological ind

关键词： Baker yeast digestive enzymes growth feed utilization hematological indices Nile tilapia.