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Integrated Analysis of Water Quality in Artificial Fishponds Using WQI and GIS in South-East Sierra Leone

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Journal of Geoscience and Environment Protection 2024年第1期12卷 145-163页

作者： Hadji D. S. Kallon Lamin R. Mansaray Misbah Fida Pratap sundar shrestha Institute of Environmental Management and Quality Control Njala University Njala Sierra Leone School of Water and Environment Chang’an University Xi’an China Quality Control Laboratory of Njala University Njala Sierra Leone Department of Surveys and Geo-Informatics School of Environmental Sciences Njala University Njala Sierra Leone

Artificial fishponds play a pivotal role in global aquaculture, serving as a source of livelihood and nourishment for many communities. Ensuring the sustained health and productivity of Fishes in these environments relies heavily on water quality management. This assessment was done to determine the water quality of ten artificial fishponds in the south-eastern part of Sierra Leone using twelve physicochemical factors (pH, BOD, EC, TDS, turbidity, COD, Fe2+, Mg2+, Ca2+, NH3, , and alkalinity) to find out the Water Quality Index (WQI) and spatial distribution of respective parameters. The assessment of artificial fishponds using WQI and Inverse Distant Weighting (IDW) integration represents a relatively underexplored area within the domain of environmental water resources. The WQI was determined using the “Weighted Arithmetic Water Quality Index’’ method. The results of WQI in the study area range from 65.05 to 147.26. Several locations have water quality deemed unsuitable for consumption, while others range from good to very poor. It is essential to address and improve water quality in locations categorized as unsuitable for consumption and very poor to ensure safe and healthy water sources. It was also clear from the calculation that the smaller the mean concentration value of the pH as compared to the ideal value (7), the smaller the WQI value and the better the water quality. To keep the artificial fishpond water in good condition, mass domestic use should be controlled, and draining of surrounding organic matter should be stopped in ponds Bo_001, Kenema_001, and Kenema_002.

关键词： Physicochemical Parameters Water Quality Index WQI-“Weighted Arithmetic Index Method”

Experimental prototyping of the adhesion braking control system design concept for a mechatronic bogie

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Railway Engineering Science 2021年第1期29卷 15-29页

作者： sundar shrestha Maksym Spiryagin Qing Wu Centre for Railway Engineering Central Queensland UniversityRockhamptonAustralia Rail Manufacturing Cooperative Research Centre(CRC) MelbourneVICAustralia

The dynamic parameters of a roller rig vary as the adhesion level *** change in dynamics parameters needs to be analysed to estimate the adhesion *** of these parameters is noise emanating from wheel–rail *** previous wheel–rail noise analysis has been conducted to mitigate those ***,in this paper,the noise is analysed to estimate the adhesion condition at the wheel–rail contact interface in combination with the other methodologies applied for this *** adhesion level changes with changes in operational and environmental *** accurately estimate the adhesion level,the influence of those factors is included in this *** testing and verification of the methodology required an accurate test prototype of the roller *** general,such testing and verification involve complex experimental works required by the intricate nature of the adhesion process and the integration of the different subsystems(***,traction,braking).To this end,a new reduced-scale roller rig is developed to study the adhesion between wheel and rail roller *** various stages involved in the development of such a complex mechatronics system are described in this ***,the proposed brake control system was validated using the test rig under various adhesion *** results indicate that the proposed brake controller has achieved a shorter stopping distance as compared to the conventional brake controller,and the brake control algorithm was able to maintain the operational condition even at the abrupt changes in adhesion condition.

关键词： Wheel–rail adhesion condition Brake controlMechatronics scaled bogie test rig Wheel–rail noiseAcoustic analysis

Real-time multibody modeling and simulation of a scaled bogie test rig

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Railway Engineering Science 2020年第2期28卷 146-159页

In wheel–rail adhesion studies,most of the test rigs used are simplified designs such as a single wheel or wheelset,but the results may not be ***,representing the complex system by using a full vehicle model provides accurate results but may incur complexity in *** trade off accuracy over complexity,a bogie model can be the optimum ***,only a real-time model can replicate its physical counterpart in the time *** such a model requires broad expertise and appropriate software and hardware.A few published works are available which deal with real-time ***,the influence of the control system has not been included in those *** address these issues,a real-time scaled bogie test rig including the control system is ***,a 1:4 scaled bogie roller rig is developed to study the adhesion between wheel and roller *** compare the performances obtained from the scaled bogie test rig and to expand the test applications,a numerical simulation model of that scaled bogie test rig is developed using Gensys multibody *** model is the complete model of the test rig which delivers more precise *** exactly represent the physical counterpart system in the time domain,a real-time scaled bogie test rig(RT-SBTR)is developed after four consecutive ***,to simulate the RT-SBTR to solve the internal state equations and functions representing the physical counterpart system in rigs used are simplified designs such as a single wheel or wheelset,but the results may not be ***,representing the complex system by using a full vehicle model provides accurate results but may incur complexity in *** trade off accuracy over complexity,a bogie model can be the optimum ***,only a real-time model can replicate its physical counterpart in the time *** such a model requires broad expertise and appropriate software and hardware.A few pub

关键词： Bogie modeling Scaled bogie test rig Realtime simulation Wheel-rail adhesion Software in loop

Recent advances in wheel–rail RCF and wear testing

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摩擦:英文版 2023年第12期11卷 2181-2203页

作者： sundar shrestha Maksym SPIRYAGIN Esteban BERNAL Qing WU Colin COLE Centre for Railway Engineering Central Queensland UniversityRockhampton 4701Australia Australasian Centre for Rail Innovation Canberra 2601Australia

The wear and rolling contact fatigue (RCF) testing approaches for wheels and rails have been reviewedand evaluated in this study. The study points out the advantages and limitations of the existing approaches. Thebroad analysis revealed that scaled laboratory-based wear testing is widely applied. However, it is necessary topredetermine the input parameters and observing parameters for scaled wear testing for three reasons: first, toemulate the real-world scenarios as closely as possible;second, to postprocess the results received from the scaledtesting and transfer them into real practice at full scale;third, to present the results in a legible/appropriate ***, most of the important parameters required for wear testing have been discussed with fundamental andsystematic explanations provided. Additionally, the transition of the parameters from the real-world into the testdomain is explained. This study also elaborates on the challenges of the RCF and wear testing processes andconcludes by providing major considerations toward successful testing.

关键词： wear testing rolling contact fatigue(RCF)testing wheel-rail

Problems,assumptions and solutions in locomotive design,traction and operational studies

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Railway Engineering Science 2022年第3期30卷 265-288页

作者： Maksym Spiryagin Qing Wu Oldrich Polach John Thorburn Wenhsi Chua Valentyn Spiryagin Sebastian Stichel sundar shrestha Esteban Bernal Sanjar Ahmad Colin Cole Tim McSweeney Centre for Railway Engineering Central Queensland UniversityRockhampton 4702Australia Independent Consultant Neuhausen am RheinfallSwitzerland Progress Rail NewcastleAustralia BHP Port HedlandAustralia Engineering Centre for Railway Transport SkolkovoRussian Federation KTH Royal Institute of Technology StockholmSweden

Locomotive design is a highly complex task that requires the use of systems engineering that depends upon knowledge from a range of disciplines and is strongly oriented on how to design and manage complex systems that operate under a wide range of different train operational conditions on various types of *** that field investigation programs for locomotive operational scenarios involve high costs and cause disruption of train operations on real railway networks and given recent developments in the rollingstock compliance standards in Australia and overseas that allow the assessment of some aspects of rail vehicle behaviour through computer simulations,a great number of multidisciplinary research studies have been performed and these can contribute to further improvement of a locomotive design technique by increasing the amount of computer-based *** paper was focused on the presentation of the all-important key components required for locomotive studies,starting from developing a realistic locomotive design model,its validation and further applications for train *** integration of all engineering disciplines is achieved by means of advanced simulation approaches that can incorporate existing AC and DC locomotive designs,hybrid locomotive designs,full locomotive traction system models,rail friction processes,the application of simplified and exact wheel-rail contact theories,wheel-rail wear and rolling contact fatigue,train dynamic behaviour and intrain forces,comprehensive track infrastructure details,and the use of co-simulation and parallel *** cosimulation and parallel computing approaches that have been implemented on Central Queensland University’s High-Performance Computing cluster for locomotive studies will be *** confidence in these approaches is based on specific validation procedures that include a locomotive model acceptance procedure and field test *** problems and limitations presented in locomot

关键词： Locomotive Design Simulation Virtual prototyping Digital twin Traction Braking Wheel-rail wear Damage

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尼泊尔的民意导向警务

现代世界警察 2022年第9期 85-87页

作者： [尼泊尔]宋德尼泊尔武装警察部队

尼泊尔警察是尼泊尔的主要执法力量。它主要负责在尼泊尔宪法确定的管辖范围内维护法律和秩序、预防犯罪和犯罪调查。除了其主要职责外,尼泊尔警察还承担着广泛的职责,例如要人保护、保护重要设施的安全、交通管理、特勤局、情报搜集、... 详细信息

尼泊尔警察是尼泊尔的主要执法力量。它主要负责在尼泊尔宪法确定的管辖范围内维护法律和秩序、预防犯罪和犯罪调查。除了其主要职责外,尼泊尔警察还承担着广泛的职责,例如要人保护、保护重要设施的安全、交通管理、特勤局、情报搜集、防暴、灾难管理、人质救援和各种其他礼仪角色。尼泊尔警察已经为国家服务了65年,始终致力于为尼泊尔人民提供有效的安全和执法服务,并为代表该国参加联合国不同的维和行动、为建立国际和平与安全作出贡献而自豪。

关键词：犯罪调查预防犯罪维和行动灾难管理执法力量交通管理国际和平与安全情报搜集