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Investigating energy policies to boost grid-connected rooftop solar PV in Sudan

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Clean Energy 2023年第5期7卷 994-1005页

作者： Tarig z.ahmed Ayah Mohamed Mawahib Eltayeb ahmed ahmed Osman Elamin Abdalgader Mohamed G.Hassan-Sayed Cambridge Institute for Sustainability Leadership(CISL) University of CambridgeCambridgeCB21QAUK Energy and Climate Change Division Faculty of Engineering and Physical ScienceThe University of SouthamptonSouthamptonSO171BJUK Institute of Engineering Research and Material Technology National Centre for ResearchKhartoumSudan/University of KhartoumSudan University of California Davis1 Shields AveDavisCA 95616USA School of Chemistry Faculty of Engineering and Physical SciencesThe University of SouthamptonSouthamptonSO171BJUK

Grid-connected rooftop solar photovoltaic(PV)systems can reduce the energy demand from the grid and significantly increase the power available to ***,rooftop solar PV has not yet been widely adopted in many sub-Saharan African countries,such as Sudan,although they are endowed with high solar radiation and in dire need of additional *** paper investigates risks and policies to increase grid-connected rooftop solar PV adoption in Sudan.A simplified United Nations Development Program Derisking Renewable Energy Investment framework is adopted to investigate this over three *** Stage 1,a list of risks and barriers was produced based on a literature review of solar PV studies in Sudan and interviews with nine *** was the risk most often mentioned(eight times from nine interviewees),followed by concerns about poor utility grid *** Stage 2,policy de-risking instruments and financial de-risking instruments were listed to overcome the *** include the intro-duction of net metering,the use of a third-party organization to monitor policy implementation,upgrade of the grid infrastructure,public awareness campaigns and energy-saving *** Stage 3,the levelized cost of electricity was estimated for a typical 2-kW rooftop PV system without policies(0.11$/kWh)and with a net-metering policy(0.07$/kWh).

关键词： energy policy rooftop solar PV Sudan energy poverty sustainable development photovoltaics

A journey towards shared governance: status and prospects for collaborative management in the protected areas of Bangladesh

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Journal of Forestry Research 2013年第3期24卷 599-605,602-605页

作者： A. z. M. Manzoor Rashid Donna Craig Sharif ahmed Mukul Niaz ahmed Khan Environmental Law School of Law University of Western SydneyAustralia Department of Forestry and Environmental Science Shahjalal University of Science and TechnologySylhet Bangladesh School of Agriculture and Food Sciences The University of QueenslandAustralia Department of Development Studies University of DhakaBangladesh

Establishment of Protected Areas （PAs）, in the face of rapid deforestation, forest degradation and climate change has been one of the key efforts in conservation of biodiversity worldwide in recent times. While Bangladesh has gained a degree of prominence in the world for its successful social forestry programs, the concept of collaborative pro- tected area management is rather new in the country, initiated in 2004 by the Bangladesh Forest Department in five PAs with financial assistance from USAID. Based on empirical evidence from three of the pilot PAs, we examined the achievements and associated challenges and prospects for co-management. Our fieldwork revealed a number of challenges faced by co-management institutions：（1） institutions were dominated by the elite group, overshadowing the voice of the community people; （2） mutual trust and collective performance are key to good governance but had not taken root in the PAs; （3） encroachment onto forest land and subsequent conversion to agriculture remained a serious problem that discouraged forest-dependent people from participating actively in co-management initiatives; （4） legal provisions （including acts, rules and policies） were not clearly and adequately disseminated and understood at the community level; （5） there remained a degree of ambiguity regarding the roles and responsibilities of forest department （FD） and co-management committees （CMC） in field operations, and this was not enhancing transparency and accountability of the overall initiative; （6） the long-term sustainability of co-management institutions was another major concern, as the local intuitional structure was still in a nascent stage, and provisioning of resources （either internally or externally） remained somewhat uncertain. We offer recommendations for improve- ment.

关键词： protected area co-management Nishorgo IPAC govern-ance

New application of microbial fuel cell-based biosensor for monitoring the quality of actual potato chips’processing wastewater

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Waste Disposal and Sustainable Energy 2019年第3期1卷 227-235页

作者： ahmed Y.Radeef zainab z.Ismail Department of Environmental Engineering University of BaghdadBaghdadIraq

In this study,a dual-chamber microbial fuel cell(MFC)fed with actual potato chips’processing wastewater(PCPW)was tested as a *** performance of MFC-based biosensor was evaluated in terms of the current measurement range,toxicity detection and sensitivity,and the operational *** results revealed that the MFC can simply be converted to an online biosensor unit to detect the harmful effect of suspended solids and acidic content in the actual PCPW on the anodic attached biofilm and the values of the generated current as well.A notable decrease in the current values was observed indicating the adverse effects of the harmful matters in the PCPW fed to the biosensor *** results proposed a competition between the harmful components and the favorable substrate in binding to the redox *** excellent fitting was obtained between the experimental and predicted results by I_(Km) model with determination coefficient(R^(2))and mean-square-error values of 0.927 and 0.363,***,a new approach was developed based on direct measurement of actual field data to replace the conventional statistical methods.

关键词： Microbial fuel cell Biosensor Modeling Potato chips processing wastewater Biodegradation

On the Computing of the Minimum Distance of Linear Block Codes by Heuristic Methods

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International Journal of Communications, Network and System Sciences 2012年第11期5卷 774-784页

作者： Mohamed Askali ahmed Azouaoui Said nouh Mostafa Belkasmi SIME Lab National School of Computer Science and Systems Analysis(ENSIAS)Mohammed V-Souisi UniversityRabatMorocco

The evaluation of the minimum distance of linear block codes remains an open problem in coding theory, and it is not easy to determine its true value by classical methods, for this reason the problem has been solved in the literature with heuristic techniques such as genetic algorithms and local search algorithms. In this paper we propose two approaches to attack the hardness of this problem. The first approach is based on genetic algorithms and it yield to good results comparing to another work based also on genetic algorithms. The second approach is based on a new randomized algorithm which we call 'Multiple Impulse Method (MIM)', where the principle is to search codewords locally around the all-zero codeword perturbed by a minimum level of noise, anticipating that the resultant nearest nonzero codewords will most likely contain the minimum Hamming-weight codeword whose Hamming weight is equal to the minimum distance of the linear code.

关键词： Minimum Distance Error Impulse Method Heuristic Methods Genetic Algorithms NP-Hardness Linear Error Correcting Codes BCH Codes QR Codes Double Circulant Codes

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热连轧过程大梁钢变形抗力预报模型

塑性工程学报 2024年 159-166页

作者：尹宝良 ahmed elmi Sahal 崔熙颖令狐克志么洪勇邝霜李学通燕山大学国家冷轧板带装备及工艺工程技术研究中心唐山钢铁集团有限责任公司河钢集团唐钢技术中心河钢集团材料技术研究院燕山大学亚稳材料制备技术与科学国家重点实验室

为解决某钢厂热连轧机组轧制700L大梁钢时因变形抗力预报精度低导致成品带钢板形质量较差的问题,首先,根据实际轧制压力等历史生产数据确定带钢的变形抗力,然后对热连轧机组变形抗力数学模型中的系数进行回归,得到适用于该机组的变形抗... 详细信息

为解决某钢厂热连轧机组轧制700L大梁钢时因变形抗力预报精度低导致成品带钢板形质量较差的问题,首先,根据实际轧制压力等历史生产数据确定带钢的变形抗力,然后对热连轧机组变形抗力数学模型中的系数进行回归,得到适用于该机组的变形抗力数学模型,同时将遗传算法和BP神经网络结合起来,建立GA-BP神经网络变形抗力预报模型,进一步将优化后的传统数学模型和GA-BP神经网络模型计算的变形抗力结果代入系统轧制力模型中,其模型计算误差分别为6%和3%。将GA-BP神经网络变形抗力模型应用到现场后, 700L大梁钢的板形合格率由原来的91.7%提高到了99.3%,板形改善效果显著。

关键词：热连轧神经网络变形抗力轧制力板形

Microstructure and mechanical properties of hot extruded 6016 aluminum alloy/graphite composites

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Journal of Materials Science & Technology 2018年第9期34卷 1580-1591页

作者： Mohamed M.El-Sayed Seleman Mohamed M.z.ahmed Sabbah Ataya Department of Metallurgical and Materials Engineering Faculty of Petroleum and Mining Engineering Suez University 43518 Suez Egypt Suez and Sinai Metallurgical and Materials Research Center of Scientific Excellence (SSMMR-CSE) 43518 Suez Egypt The British University in Egypt Mechanical Engineering Deportment El-Sherouk City 11837 Cairo Egypt Department of Mechanical Engineering College of Engineering AI Imam Mohammad Ibn Saud Islamic University Riyadh 11432 saudi Arabia

The incorporation of graphite particles into AA6016 aluminum alloy matrix to fabricate metal/ceramic composites is still a great challenge and various parameters should be considered. In this study, dense AA6016 aluminum alloy/（0-20 wt%） graphite composites have successfully been fabricated by powder metallurgy process. At first, the mixed aluminum and graphite powders were cold compacted at 200 MPa and then sintered at 500 ℃ for 1 h followed by hot extrusion at 450 ℃. The influence of ceramic phases（free graphite and in-situ formed carbides） on microstructure, physical and mechanical properties of the produced composites were finally investigated. The results show that the fabricated composites have a relative density of over 98%. SEM observations indicate that the graphite has a good dispersion in the alloy matrix even at high graphite content. Hardness of all the produced composites was higher than that of aluminum alloy matrix. No cracks were observed at strain less than 23% for all hot extruded *** strength, reduction in height, ultimate tensile stress, fracture stress, yield stress, and fracture strain of all Al/graphite composites were determined by high precision second order equations. Both compressive and ultimate tensile strengths have been correlated to microstructure constituents with focusing on the in-situ formed ceramic phases, silicon carbide（SiC） and aluminum carbide（Al4 C3）. The ductile fracture mode of the produced composites became less dominant with increasing free graphite content and in-situ formed carbides. Wear resistance of Al/graphite composites was increased with increasing graphite content. Aluminum/20 wt% graphite composite exhibited superior wear resistance over that of AA6016 aluminum alloy.

关键词： AA6016/graphite composites Hot extrusion In-situ carbides Mechanical properties Wear resistance Fracture behavior

Modeling Liver Cancer and Leukemia Data Using Arcsine-Gaussian Distribution

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Computers, Materials & Continua 2021年第5期67卷 2185-2202页

作者： Farouq Mohammad A.Alam Sharifah Alrajhi Mazen Nassar ahmed z.Afify Department of Statistics Faculty of ScienceKing Abdulaziz UniversityJeddah21589Saudi Arabia Department of Statistics Faculty of CommerceZagazig UniversityZagazig44511Egypt Department of Statistics Mathematics and InsuranceBenha UniversityBenha13511Egypt

The main objective of this paper is to discuss a general family of distributions generated from the symmetrical arcsine *** considered family includes various asymmetrical and symmetrical probability distributions as special cases.A particular case of a symmetrical probability distribution from this family is the Arcsine–Gaussian *** statistical properties of this distribution including quantile,mean residual life,order statistics and moments are *** Arcsine–Gaussian parameters are estimated using two classical estimation methods called moments and maximum likelihood methods.A simulation study which provides asymptotic distribution of all considered point estimators,90%and 95%asymptotic confidence intervals are performed to examine the estimation efficiency of the considered methods *** simulation results show that both biases and variances of the estimators tend to zero as the sample size increases,i.e.,the estimators are asymptotically ***,when the sample size increases the coverage probabilities of the confidence intervals increase to the nominal levels,while the corresponding length decrease and approach *** real data sets from the medicine filed are used to illustrate the flexibility of the Arcsine–Gaussian distribution as compared with the normal,logistic,and Cauchy *** proposed distribution is very versatile to fit real applications and can be used as a good alternative to the traditional gaussian distribution.

关键词： Liver cancer data leukemia data normal distribution moments estimation maximum likelihood estimation

Investigation on the mechanical properties of sintered porous copper compacts

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China Particuology 2007年第6期5卷 391-394页

作者： Yasser M.z. ahmed Mohamed I. Riad ahmed I. zaky Mohammed Abdel-Aziz Mohamed M.H. Shalabi Central Metallurgical Research and Development Institute CMRDI El-Felzat Street El-Tabbin P.O. Box 87 Helwan Cairo Egypt

In line with recent attention on porous metals having low and medium porosities in the range of 20-50%, this paper studies the effect of porosity on the mechanical properties of sintered copper compacts. Experiments were designed to investigate the effect of porosity, applied stress and sliding velocity on the wear rate of copper compacts, leading to the finding that the effects of both porosity and applied stress of the wear test on the wear rate are approximately similar and higher than that of sliding velocity. The investigation concerning the effect of porosity on compressive strength indicated that the stress-strain curve of high-porosity compact exhibited identifiable ultimate strength points, though low-porosity compact showed distinct stages of elastic plastic behavior.

关键词： Porous copper Wear rate Compressive strength Experimental design technique

Neutron activation analysis of ceramic tiles and its component and radon exhalation rate

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Journal of Environmental Sciences 2004年第1期16卷 94-99页

作者： A.El-Shershaby A.Sroor F.ahmed A.S.Abdel-Haleem z.Abdel Nuclear Physics Laboratory Faculty of WomenAin-Shams UniversityNuclear Physics LaboratoryFaculty of WomenAin-Shams UniversityIonizing Radiation DepartmentNational Institute for StandardsHot Laboratories CenterAtomic Energy AuthorityNuclear Physics LaboratoryFaculty of WomenAin-Shams University Cairo EgyptCairo EgyptGiza EgyptCairo EgyptCairo Egypt

The concentrations of 20 trace elements in several ceramics tiles and ceramic composites used in Egypt were elementally analyzed by neutron activation analysis(NAA) technique. The samples and standard were irradiated with reactor for 4 h(in the Second Research Egyptian Reactor(Et-RR-2)) with thermal neutron flux 5.9×10 13 n/(cm 2·s).The gamma-ray spectra obtained were measured for several times by means of the hyper pure germanium detection system(HPGe). Also a solid state nuclear track detector(SSNTD) CR-39, was used to measure the emanation rate of radon for these samples. The radium concentrations were found to vary from 0.39—3.59 ppm and the emanation rates were found to vary from (0.728—5.688) × 10 -4 kg/(m 2· s).The elemental analysis of the ceramic tiles and ceramic composites have a great importance in assigning the physical properties and in turn the quality of the material.

关键词： ceramic neutron activation analysis(NAA) radon emanation solid state nuclear track detector(SSNTD)