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基于微课的高职“Solid Works三维建模设计”课程教学设计 被引量:7
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作者 王庭俊 王波 张崎静 《职业教育研究》 2014年第6期162-164,共3页
针对传统"Solid Works三维建模设计"课程教学存在的不足,结合多年实践教学经验,将微课引入"Solid Works三维建模设计"课程教学当中,有助于提升学生自主学习能力,实现分层教学,提升"Solid Works三维建模设计&qu... 针对传统"Solid Works三维建模设计"课程教学存在的不足,结合多年实践教学经验,将微课引入"Solid Works三维建模设计"课程教学当中,有助于提升学生自主学习能力,实现分层教学,提升"Solid Works三维建模设计"课堂教学效果。 展开更多
关键词 微课程 solid WORKS 三维建模设计 课程教学设计
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“Solid Edge三维造型”模块化案例教学设计 被引量:1
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作者 周梅梅 《天津职业院校联合学报》 2020年第8期46-50,共5页
对于工科专业中的基础绘图课程即Solid Edge三维造型课程,采用一种新型教学方式即模块化案例法教学,通过对课程划分模块,这模块可能包含一门课程或者多门专业课程中的一部分,对每一模块选取相应案例,通过对案例的实践练习,达到相应知识... 对于工科专业中的基础绘图课程即Solid Edge三维造型课程,采用一种新型教学方式即模块化案例法教学,通过对课程划分模块,这模块可能包含一门课程或者多门专业课程中的一部分,对每一模块选取相应案例,通过对案例的实践练习,达到相应知识点融会贯通的效果,进而体现“以学生为主体、教师为主导”的学生主体地位课堂教学模式。 展开更多
关键词 solid Edge 模块化 案例法教学
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基于Solid Works的针型阀虚拟设计与干涉检查
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作者 余志伟 《机械管理开发》 2024年第9期294-296,共3页
虚拟设计技术是以计算机仿真技术为前提,在产品设计阶段,实时、并行地模拟出产品开发全过程。以Solid Works软件为平台,以针型阀为例,详细论述了零件三维建模的方法和技巧,虚拟装配中的连接定位、干涉检查等常见问题和解决办法。从而缩... 虚拟设计技术是以计算机仿真技术为前提,在产品设计阶段,实时、并行地模拟出产品开发全过程。以Solid Works软件为平台,以针型阀为例,详细论述了零件三维建模的方法和技巧,虚拟装配中的连接定位、干涉检查等常见问题和解决办法。从而缩短产品的开发周期、降低开发成本、优化设计质量,对产品设计开发人员具有较高的参考价值。 展开更多
关键词 针型阀 实体建模 虚拟装配 干涉检查
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基于Solid Edge自动生成数控加工图的二次开发研究
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作者 吴事谱 陆祉好 阳开应 《锅炉技术》 北大核心 2024年第4期21-26,共6页
基于Solid Edge软件平台,利用C#进行二次开发,设计出一款利用三维设计模型和组件图生成数控加工工艺图纸的批量设计软件,并详细展示了软件的工作流程、原理和关键技术。经应用验证,该软件具有出图快、信息匹配度高、适用模型范围广、操... 基于Solid Edge软件平台,利用C#进行二次开发,设计出一款利用三维设计模型和组件图生成数控加工工艺图纸的批量设计软件,并详细展示了软件的工作流程、原理和关键技术。经应用验证,该软件具有出图快、信息匹配度高、适用模型范围广、操作灵活、界面友好等优点,以此实现了车间的无纸化高效数据传输和敏捷生产。 展开更多
关键词 solid Edge 二次开发 数控加工图 轮廓图 C# 工程图 三维设计
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基于SolidWorks的导线卡线器三维建模及运动仿真 被引量:1
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作者 杨文雄 曾德惠 +2 位作者 刘璐 胡宁丹 刘桂花 《机械管理开发》 2024年第4期11-13,共3页
为解决导线挂线时的滑线、跑线问题,提高卡线器的设计效率,通过分析卡线器的结构和工作原理,以SKLT-60卡线器为主要研究对象,基于三维软件SolidWorks及其Motion插件,进行零件建模、虚拟装配及运动仿真,得到卡线器的夹嘴夹持力、上夹嘴... 为解决导线挂线时的滑线、跑线问题,提高卡线器的设计效率,通过分析卡线器的结构和工作原理,以SKLT-60卡线器为主要研究对象,基于三维软件SolidWorks及其Motion插件,进行零件建模、虚拟装配及运动仿真,得到卡线器的夹嘴夹持力、上夹嘴运动轨迹、摇杆极限位置及滑块行程随时间的变化曲线.仿真结果表明:夹嘴夹持力、传动角及拉环行程满足设计要求.将虚拟样机技术和运动仿真技术相结合,对卡线器进行仿真分析,具有较好的模拟效果,缩短了产品开发周期,还能根据仿真结果进行结构优化,为类似设计提供了一种快捷、可靠的方法. 展开更多
关键词 导线卡线器 solidWORKS 三维建模 虚拟装配 运动仿真
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Acyclovir-Loaded Solid Lipid Nanoparticles: A Permeation and Penetrability Study
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作者 Anyoli Taly Adriana Camino +3 位作者 Cirana Rodriguez Evelyn Pena Alfredo Inatti Xenon Serrano 《Journal of Biosciences and Medicines》 2024年第10期316-327,共12页
Herpes simplex virus type I is a cutaneous infection treated with acyclovir. The topical treatment has therapeutic challenges due to the deficient delivery of the drug through epithelial barriers. This results in an i... Herpes simplex virus type I is a cutaneous infection treated with acyclovir. The topical treatment has therapeutic challenges due to the deficient delivery of the drug through epithelial barriers. This results in an inadequate drug-virus interaction in the basal epidermis (virus replication site). For this reason, it is essential to generate drug carrier systems that overcome these limitations. In this study, we evaluated the permeation (through in vitro test Franz cells) and penetration (by ex vivo test Tape Stripping) of a topical formulation of acyclovir loaded in solid lipid nanoparticles and a conventional formulation (Aciclor®). The acyclovir solid lipid nanoparticles were prepared using hot homogenization and sonication methods. The results yielded a particle size of 85 ± 2 nm, a polydispersity index of 0.24 ± 0.01, a zeta potential of −16 ± 2 mV, and 94% ± 3% of encapsulated drug. The in vitro test revealed that the permeability of acyclovir solid lipid nanoparticles formulation was superior compared to reference formulation, with values of 1473.74 ± 30.14 µg/cm2 for the solid lipid nanoparticles and 893.36 ± 38.09 µg/cm2 for the reference formulation. The ex vivo test demonstrated that acyclovir solid lipid nanoparticles exhibited superior penetrability through the stratum corneum compared to the reference formulation, with total amounts of 3767 µg for the solid lipid nanoparticles and 2162 µg for the reference formulation. These findings seem promising in advancing new effective therapies against herpes generated by herpes simplex virus type I. 展开更多
关键词 HERPES ACYCLOVIR solid Lipid Nanoparticles Franz Cells Tape Stripping
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Ultra-Net Emission and Solid Waste Transfer of Air Pollutants in Steel, Power and Cement Industries—The Idea of Construction and Key Technology of Denitration Engineering Transformation and By-Product Formation
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作者 Weiling Chu Linling Wu +1 位作者 Jing Yuan Qianfeng Zhang 《Journal of Environmental Protection》 2024年第11期995-1005,共11页
In this paper, an integrated desulfurization and denitrification technology is proposed for ultra-low emissions of SO2 and NOx in the steel, power and cement industries. A cost-effective and operationally efficient co... In this paper, an integrated desulfurization and denitrification technology is proposed for ultra-low emissions of SO2 and NOx in the steel, power and cement industries. A cost-effective and operationally efficient control strategy is realized through a forced oxidation-absorption-reduction process, which reduces equipment investment and operating costs. The technology was adapted to continuous and intermittent denitrification in different temperature zones, promoting the recycling of desulfurization and denitrification products. The study also explored the use of a highly active absorbent obtained by the hydration reaction of coal ash and lime from a power company for the desulfurization and denitrification of sintered flue gases in iron and steel mills, which produces by-products that can be used as retarding agents in the cement industry, resulting in a circular economy. The article emphasizes the importance of improving the lime digestion process and developing new denitrification agents for environmentally safe and cost-effective flue gas treatment. 展开更多
关键词 Air Pollution Denitration Engineering Ultra-Net Emissions solid Waste Transfer
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Household Solid Waste Awareness and Practices among Residents of Windhoek, Namibia
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作者 Jolosi Mukena Youcai Zhao Songa Mutonga 《Journal of Environmental Protection》 2024年第6期641-655,共15页
This study explores household solid waste management (HSWM) practices and awareness among residents of Windhoek West, a rapidly urbanizing constituency in the Khomas Region of Namibia. Employing a descriptive methodol... This study explores household solid waste management (HSWM) practices and awareness among residents of Windhoek West, a rapidly urbanizing constituency in the Khomas Region of Namibia. Employing a descriptive methodology, the research investigates the interplay between public awareness, regulatory frameworks, and the availability of waste management facilities to assess their impact on waste management behaviors. Our findings indicate significant gaps in both knowledge and infrastructure that hinder effective waste management. The study reveals that while there is a high willingness among residents to engage in recycling and waste reduction, actual practices are limited due to inadequate facilities and lack of stringent enforcement of waste policies. This research identifies key factors that influence waste management practices, including demographic characteristics and access to waste management facilities. It also proposes actionable strategies such as expanding recycling and sorting facilities, enhancing educational campaigns tailored to local needs, and implementing regular enforcement mechanisms. These strategies are aimed at improving compliance with waste management protocols and fostering a culture of environmental responsibility. The results of this investigation show the critical role of ongoing education and infrastructural improvement in bridging existing knowledge gaps and facilitating effective waste management practices. This research lays a foundational step toward enhancing sustainable urban development and effective waste management in Windhoek, providing valuable insights for policymakers, community leaders, and stakeholders engaged in urban environmental management. 展开更多
关键词 Household solid Waste Management (HSWM) Public Awareness Waste Segregation Windhoek West Recycling Facilities
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Solid Particle Erosion of AISI 304 SS Caused by Alumina Particles
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作者 Juan Rodrigo Laguna-Camacho Celia María Calderón-Ramón +8 位作者 Víctor Velázquez-Martínez Javier Calderón-Sánchez Gabriel Juárez-Morales Cristóbal Cortez-Domínguez Jorge Alberto Chagoya-Ramírez Jesús Enrique López-Calderón Paul Ramírez-Sánchez Silvia Marina Sánchez-Yáñez Héctor Daniel López-Calderón 《Journal of Surface Engineered Materials and Advanced Technology》 2024年第1期1-14,共14页
This research work was carried out with the aim of continuing to expand knowledge on the behaviour of AISI 304 stainless steel against solid particle erosion. In this particular case, the steel was subjected to the im... This research work was carried out with the aim of continuing to expand knowledge on the behaviour of AISI 304 stainless steel against solid particle erosion. In this particular case, the steel was subjected to the impact of alumina particles, which are hard abrasives with irregular and angular shapes. Different characterization techniques were applied to gain a better understanding of alumina. For instance, particle size distribution was obtained using the Analysette 28 Image Sizer and the particle size was between 300 - 400 µm. SEM and EDS analysis were used to know the morphology and chemical composition of both the abrasive particles and AISI 304 stainless steel. Additionally, mechanical properties values such as the hardness and Young’s modulus of AISI 304 steel were attained using a Berkovich indenter (model TTX-NHT, CSM Instruments). On the other hand, two tests were carried out for each impact angle used, 30˚, 45˚, 60˚ and 90˚, with a particle velocity of 24 ± 2 m/s and an abrasive flow rate of 63 ± 0.5 g/min, employing a test rig based on ASTM G76-95 standard. SEM images using two detectors, Backscattered Electron Detector (BED) and Low Electron Detector (LED), were employed to identify the wear mechanisms on the AISI 304 eroded surfaces at 30˚ and 90˚. Finally, the erosion rates of AISI 304 compared to those results reached by AISI 1018 steel and AISI 420 stainless steel tested under identical conditions in previous works. 展开更多
关键词 solid Particle Erosion AISI 304 Stainless Steel Alumina Particles Wear Mechanisms Erosion Rates
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Solid-Pseudopapillary Tumor: Case Report and Literature Review
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作者 Nomenjanahary Lalaina Rabarison Manoahasina Ranaliarinosy +1 位作者 Razafimahefa Vahatra Joëlle Randrianjafisamindrakotroka Nantenaina Soa 《Open Journal of Pathology》 2024年第1期11-15,共5页
Solid-pseudopapillary tumor of the pancreas (SPT) or Frantz’s tumor is a rare epithelial neoplasm that represents 0.3% to 2.7% of exocrine pancreatic tumors. These tumors occur mainly in young women and have a good p... Solid-pseudopapillary tumor of the pancreas (SPT) or Frantz’s tumor is a rare epithelial neoplasm that represents 0.3% to 2.7% of exocrine pancreatic tumors. These tumors occur mainly in young women and have a good prognosis. We present a case of a 19-year-old female patient who presented to the emergency for abdominal pain. Physical examination reveals a left hypochondrium mass. Ultrasound imaging showed an encapsulated caudal pancreatic mass with cystic components. The patient underwent tumor excision and lymph node removal. Macroscopically, the tumor was encapsulated and measuring 12 × 8 × 7 cm. It has a solid-cystic and hemorrhagic appearance inside. Histologically, the tumor had two components: solid and papillary. Tumor tissue showed monomorphic tumor cells radiating around blood vessels. Perineural invasion and vascular emboli were not seen. Three lymph nodes without metastases were observed. The diagnosis of solid-pseudopapillary tumor of the pancreas (SPT) or Frantz’s tumor was retained. Solid-pseudo-papillary tumor of the pancreas is rare and not always suspected by the physician. The clinical and imaging patterns are not specific. Anatomopathological examination confirmed the diagnosis. The patient underwent curative surgery. 展开更多
关键词 PANCREAS TUMOR solid-Pseudopapillary Frantz Antananarivo
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Study of Total Dissolved Solids (TDS) Concentrations Factor of SWCC Al-Khobar Plant Seawater Intakes
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作者 Ahmed Al-Kubaish Jamal Salama Waleed Al-Jurayan 《Computational Water, Energy, and Environmental Engineering》 2024年第1期1-12,共12页
This study presents a significant contribution to the field of water quality assessment and sustainable water management practices. By evaluating the levels of total dissolved solids (TDS) in seawater intakes within A... This study presents a significant contribution to the field of water quality assessment and sustainable water management practices. By evaluating the levels of total dissolved solids (TDS) in seawater intakes within Al-Khobar desalination production system, the study addresses a crucial aspect of water treatment and environmental impact assessment. The findings provide valuable insights into the variations and trends of TDS levels across different phases of the system, highlighting the importance of monitoring and management strategies. The study provided both gravimetric total dissolved solids (TDS) and electrical conductivity (EC) measurements to analyze TDS calculation factor and evaluate measurement accuracy. Results revealed significant variations in TDS levels across the sampling locations, with phase-2 exhibiting higher levels and greater fluctuations. Phase-3 displayed similar trends but with lower TDS levels, while phase-4 showed slightly different behavior with higher average TDS levels. EC measurements demonstrated a strong correlation with TDS, providing a reliable estimation. However, additional methods such as gravimetric analysis should be employed to confirm TDS measurements. The findings contribute to understanding water quality in the Al-Khobar desalination system, aiding in monitoring, management, and decision-making processes for water treatment and environmental impact assessment. The study enhances the credibility of water quality assessments and supports sustainable water management practices. 展开更多
关键词 Total Dissolved solids CONDUCTIVITY Seawater DESALINATION
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The Impact of Solid Waste Generation, Storage and Separation Practices among Households on the Environment in Freetown
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作者 Abdul Malik Bangura Patrick Fayia Kanty 《Journal of Geoscience and Environment Protection》 2024年第8期219-238,共20页
As urbanization and population growth continue to increase in Freetown, due to changes in economic, social, environmental, political, and demographic factors, the municipal solid waste (MSW) generation also continues ... As urbanization and population growth continue to increase in Freetown, due to changes in economic, social, environmental, political, and demographic factors, the municipal solid waste (MSW) generation also continues to increase, making its management difficult for the municipal authority. Efficient separation and storage of solid waste at the source of generation can boost resource and energy recovery from MSW. This study examines the municipal solid waste management (MSWM) process, focusing on generation, storage and separation practices among households and their impact on the environment in Freetown. It emphasizes the inclusion of MSWM programs in primary schools to raise public awareness, the implementation of effective waste management practices, and the enforcement of related policies to enhance the MSWM sector, contributing to sustainable MSWM in Freetown. By utilizing both qualitative and quantitative methods, 393 structured questionnaires were administered across three selected sections to collect data on household solid waste storage and separation practices. The analysis employed descriptive statistics, using Origin-Pro9 and MS Excel. The findings show that with a population of 1.53 million people in Freetown, the per capita solid waste generation is 0.58 kg per day. The findings also show that 97% of the households have storage facilities as a result of the increase in awareness and education about the proper storage of solid waste. However, 96% of respondents do not practice separation of solid waste at the source of generation, which has become a concern among researchers in Sierra Leone. Additionally, 88% of respondents are unaware of ISWM principles, with only 12% aware, most of whom have received some education on proper solid waste management. The study recommends improving MSWM in Freetown to protect public health and the environment. 展开更多
关键词 GENERATION STORAGE SEPARATION Household Municipal solid Waste Freetown
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Assessment of the Characteristics of the Municipal Solid Waste Compost in Lebanon
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作者 Rana Sawaya Jalal Halwani +2 位作者 Nada Nehme Hiba Alawiye Walaa Diab 《Journal of Geoscience and Environment Protection》 2024年第5期17-39,共23页
Waste management is crucial due to the fast increase of human population, causing an increase in solid waste generation which if not properly managed causes environmental problems. Around 57% of the wastes generated f... Waste management is crucial due to the fast increase of human population, causing an increase in solid waste generation which if not properly managed causes environmental problems. Around 57% of the wastes generated from homes are made up of green material (fruits, vegetables…). Thus, reusing and recycling green wastes through composting is one way of reducing the waste load to landfills. Composting is the transformation of raw organic materials into organic soil amendments that provide nutrients to crops and enhance the tilth, fertility, and productivity of soils. Aerobic windrow composting system at Sukomi Greensite facility located at Karantina is performed, where materials biodegrade under controlled conditions to produce compost. However, assessment of the quality of the compost is fundamental in order to determine its usages. Thus, regular testing of physical, chemical and biological parameters was performed for adequate monitoring purposes. The basic objective of this study was to determine the characteristics of the Lebanese municipal solid waste compost on a yearly basis and compare these characteristics amongst the years. Hence, each parameter was tested and compared to the BNQ international Canadian standards for proper classification of the compost and adequate identification of its usages. The preliminary data obtained were statistically diagnosed through principal component analysis by Spadv55 software. All the data reflected the normal content value of the studied parameters with minor differences between the years except for year 2007 which demonstrated higher levels of Potassium, Phosphate, Lead and Cadmium. The characteristics of the compost enabled it to be used as a soil amendment on all types of agricultural and landscape commodities at the adequate dosages and proper timing. This data will additionally reflect the efficiency of the solid waste management practices adopted via highlighting the importance of the implementation of the integrated solid waste management practices. 展开更多
关键词 COMPOSTING Organic Material Lebanon CONTAMINATION solid Waste Management
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Volatile Solid and Bury Period Influence on Odorous Material Production in Simulating Landfill Treatment
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作者 Peng Lu Yuanyuan Zhang +5 位作者 Linan Xing Ying Wang Hong Lu Dongbei Yue Wei Cheng Jin Liu 《Journal of Geoscience and Environment Protection》 2024年第1期120-129,共10页
Odor pollution in landfill area has attracted more social attention in China. It is very important to control the generation of odor pollutants in situ. Analyzing odorous materials production form buried waste, simula... Odor pollution in landfill area has attracted more social attention in China. It is very important to control the generation of odor pollutants in situ. Analyzing odorous materials production form buried waste, simulated columns of different volatile solid (VS) content and different buried period waste were designed. Gas compounds produced from the columns were collected and analyzed by comprehensive two-dimensional gas chromatography (GC × GC) method. It has remarkable relationship between VS content and concentrations of odorous material. When VS content more than 40%, the total amount of odorous compounds increases remarkably. It can be inferred that reduced VS content of original waste may effective decreasing odorous materials production in landfill area. The old rubbish produced more odorous compounds than that of fresh one in simulated columns. 展开更多
关键词 Volatile solid Odorous Material Bury Period
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Thermal Decomposition of Olive-Solid Waste by TGA: Characterization and Devolatilization Kinetics under Nitrogen and Oxygen Atmospheres
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作者 Yahya H. Khraisha 《Journal of Power and Energy Engineering》 2024年第3期31-47,共17页
Despite the fact that a few countries in the Mediterranean and the Middle East have limited crude oil reserves, they have abundant biomass feedstocks. For instance, Jordan relies heavily on the importation of natural ... Despite the fact that a few countries in the Mediterranean and the Middle East have limited crude oil reserves, they have abundant biomass feedstocks. For instance, Jordan relies heavily on the importation of natural gas and crude oil for its energy needs;but, by applying thermochemical conversion techniques, leftover olive oil can be used to replace these energy sources. Understanding the chemical, physical, and thermal characteristics of raw materials is essential to obtaining the most out of these conversion processes. Thermogravimetric analysis was used in this study to examine the thermal behavior of olive-solid residue (kernel) at three different heating rates (5, 20 and 40 C/min) in nitrogen and oxygen atmospheres. The initial degradation temperature, the residual weight at 500 and 700˚C and the thermal degradation rate during the devolatilization stage (below 400˚C) were all determined. It was found that in N<sub>2</sub> and O<sub>2</sub> atmospheres, both the initial degradation temperature and the degradation rate increase with increasing heating rates. As heating rates increase in the N<sub>2</sub> atmosphere, the residual weight at 500 or 700˚C decreases slightly, but at low heating rates compared to high heating rates in the O<sub>2</sub> atmosphere, it decreases significantly. This suggests that a longer lignin oxidation process is better than a shorter one. Coats and Redfern approach was used to identify the mechanism and activation energy for the devolatilization stage of pyrolysis and oxidation reactions. The process mechanism analysis revealed that the model of first-order and second-order reactions may adequately describe the mechanism of heat degradation of the devolatilization step of olive-solid waste for pyrolysis and oxidation processes, respectively. 展开更多
关键词 Biomass Olive-solid Waste THERMOGRAVIMETRY Pyrolysis Oxidation Heating Rates Kinetics
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Solid Waste Sector Tested by Stakeholder Dynamics in Koudougou (Burkina Faso)
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作者 Zakaria Zongo Issa Sory 《Journal of Geoscience and Environment Protection》 2024年第10期308-320,共13页
Solid waste management is one of the major concerns of the authorities in the town of Koudougou. The town’s dynamic is reflected in relative demographic growth and consumption patterns that are conducive to the forma... Solid waste management is one of the major concerns of the authorities in the town of Koudougou. The town’s dynamic is reflected in relative demographic growth and consumption patterns that are conducive to the formation of landfill sites. These landfills are the source of numerous environmental consequences and risk factors for local residents. The aim of this article is to analyze the dysfunctions in the solid waste sector caused by the interplay of actors. It draws on secondary data from the state of the art on the subject and primary data collected from 305 households and 89 actors in the sector between September 2022 and March 2023, as part of an ongoing thesis. These data show that the interplay of actors contributes to the malfunctioning of pre-collection and secondary collection, and remains a factor in the proliferation of illegal dumpsites. 展开更多
关键词 solid Waste Waste Management Stakeholder Games Koudougou Burkina Faso
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Impacts of Climate Change on Seawater Temperature and Total Dissolved Solids: Challenges and Sustainable Solutions for Reverse Osmosis Desalination in the Arabian Gulf Region
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作者 Ahmed Al Kubaish Jamal Salama 《Computational Water, Energy, and Environmental Engineering》 2024年第1期86-93,共8页
This article examines the influence of seawater temperature and total dissolved solids (TDS) on reverse osmosis (RO) desalination in the Arabian Gulf region, with a focus on the impact of climate change. The study hig... This article examines the influence of seawater temperature and total dissolved solids (TDS) on reverse osmosis (RO) desalination in the Arabian Gulf region, with a focus on the impact of climate change. The study highlights the changes in seawater temperature and TDS levels over the years and discusses their effects on the efficiency and productivity of RO desalination plants. It emphasizes the importance of monitoring TDS levels and controlling seawater temperature to optimize water production. The article also suggests various solutions, including intensive pre-treatment, development of high-performance membranes, exploration of alternative water sources, and regulation of discharges into the Gulf, to ensure sustainable water supply in the face of rising TDS levels and seawater temperature. Further research and comprehensive monitoring are recommended to understand the implications of these findings and develop effective strategies for the management of marine resources in the Arabian Gulf. 展开更多
关键词 Climate Change TEMPERATURE Reverse Osmosis Seawater Total Dissolved solids DESALINATION
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Tensile Shock Physics in Compressible Thermoviscoelastic Solid Medium
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作者 Karan S. Surana Elie Abboud 《Applied Mathematics》 2024年第10期719-744,共26页
This paper addresses tensile shock physics in thermoviscoelastic (TVE) solids without memory. The mathematical model is derived using conservation and balance laws (CBL) of classical continuum mechanics (CCM), incorpo... This paper addresses tensile shock physics in thermoviscoelastic (TVE) solids without memory. The mathematical model is derived using conservation and balance laws (CBL) of classical continuum mechanics (CCM), incorporating the contravariant second Piola-Kirchhoff stress tensor, the covariant Green’s strain tensor, and its rates up to order n. This mathematical model permits the study of finite deformation and finite strain compressible deformation physics with an ordered rate dissipation mechanism. Constitutive theories are derived using conjugate pairs in entropy inequality and the representation theorem. The resulting mathematical model is both thermodynamically and mathematically consistent and has closure. The solution of the initial value problems (IVPs) describing evolutions is obtained using a variationally consistent space-time coupled finite element method, derived using space-time residual functional in which the local approximations are in hpk higher-order scalar product spaces. This permits accurate description problem physics over the discretization and also permits precise a posteriori computation of the space-time residual functional, an accurate measure of the accuracy of the computed solution. Model problem studies are presented to demonstrate tensile shock formation, propagation, reflection, and interaction. A unique feature of this research is that tensile shocks can only exist in solid matter, as their existence requires a medium to be elastic (presence of strain), which is only possible in a solid medium. In tensile shock physics, a decrease in the density of the medium caused by tensile waves leads to shock formation ahead of the wave. In contrast, in compressive shocks, an increase in density and the corresponding compressive waves result in the formation of compression shocks behind of the wave. Although these are two similar phenomena, they are inherently different in nature. To our knowledge, this work has not been reported in the published literature. 展开更多
关键词 Tensile Shock Physics Tensile Waves Elastic Viscoelastic solids Variationally Consistent Space-Time Coupled Space-Time Residual Functional A Posteriori Finite Element Method Wave Speed Conservation and Balance Laws
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Modeling and Validation of Thrust Prediction of Underwater Solid Rocket Motor
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作者 Shilin Hu Chao Yin +1 位作者 Wei Kang Muyao Xue 《World Journal of Engineering and Technology》 2024年第4期1090-1104,共15页
The solid rocket motor driven system is one of the common ways for submarines to launch underwater missiles. It has significant advantages in improving the missile’s water exit speed, anti-interference capability, an... The solid rocket motor driven system is one of the common ways for submarines to launch underwater missiles. It has significant advantages in improving the missile’s water exit speed, anti-interference capability, and enemy striking power. The prediction of the underwater loading is a preliminary factor for the power system design of the underwater vehicle. This paper presents a rapid prediction method and validated by the experimental study for the underwater thrust of the solid rocket motor. Based on the potential flow assumption of the water field, a model of the bubble and a one-dimensional quasi-steady model of the nozzle are established to directly solve the flow status of the nozzle. The aerodynamic thrust and hydrodynamic thrust have been calculated and analyzed. The calculation results are within 5% error of the experimental results. Moreover, a design platform to predict the underwater thrust of the solid rocket motor has been developed based on Python and the PyQt library, which shows excellent system adaptability and computational efficiency. 展开更多
关键词 Power System Design Underwater Vehicle solid Rocket Motor Thrust Prediction
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Current Situation Analysis and Suggestions for Solid Waste Management Practices among Households in Freetown
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作者 Patrick Fayia Kanty Mohamed Yateh Yongji Zhang 《Journal of Geoscience and Environment Protection》 2024年第3期95-109,共15页
Freetown which is the capital city of Sierra Leone is facing challenges with population growth, urbanization, and industrialization, leading to an increase in municipal solid waste (MSW) generation. The study aims to ... Freetown which is the capital city of Sierra Leone is facing challenges with population growth, urbanization, and industrialization, leading to an increase in municipal solid waste (MSW) generation. The study aims to evaluate MSW generation, composition, and disposal methods, as well as the impact of collection fees, policy implementation, and women’s participation in municipal solid waste management (MSWM). The study used both qualitative and quantitative methods for data collection and analysis. The study administered 393 structured questionnaires in three selected sections to collect data on variables such as family size, education, level of knowledge, etc. The study used door-to-door data collection to determine the rate of solid waste generation, composition, and disposal in 66 households from two of the selected sections and 34 households from the other section to evaluate the current situation of MSWM practices among households in Freetown. The study used a descriptive statistic to analyze the data collected using Origin-Pro9 and MS Excel software. The findings showed that with a 4.2% urban growth rate, Freetown had a population of 1,467,543 in 2023, generating 851 tons of MSW per day, with organic waste accounting for 78% of the total MSW generated. Plastic waste generation also increased from 7.6% in 2020 to 13% in 2023. The study emphasizes the need to sustain the MSWM system by prioritizing solid waste collection fees, policy enforcement, and women’s participation in the MSWM sector. It further suggests and provides recommendations for developing an efficient and sustainable MSWM system in Sierra Leone, including knowledge transfer from countries like China and the US. 展开更多
关键词 Freetown Municipal solid Waste Management Waste Composition Waste Disposal Waste Generation
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