World Journal of Engineering and Technology最新文献_第7页

Non-Isothermal Crystallization Kinetics of a Rapidly Solidified as-Cast TiZrHfNiCu High Entropy Bulk Metallic Glass 快速凝固铸态TiZrHfNiCu高熵大块金属玻璃的非等温结晶动力学

World Journal of Engineering and Technology Pub Date : 2020-07-09 DOI: 10.4236/wjet.2020.83023

N. H. Nordin, Faizi Mohamad, N. A. Jamal

{"title":"Non-Isothermal Crystallization Kinetics of a Rapidly Solidified as-Cast TiZrHfNiCu High Entropy Bulk Metallic Glass","authors":"N. H. Nordin, Faizi Mohamad, N. A. Jamal","doi":"10.4236/wjet.2020.83023","DOIUrl":"https://doi.org/10.4236/wjet.2020.83023","url":null,"abstract":"This paper aims to investigate the thermal behavior and crystallization kinetics of TiZrHfNiCu high entropy bulk metallic glass (HE-BMG) alloy using the standard procedure of Differential Scanning Calorimetric (DSC) annealing technique. The alloy was produced using an arc melting machine with a critical diameter of 1.5 mm. The crystallization kinetics and phase transformation mechanism of TiZrHfNiCu HE-BMG was investigated under the isochronal condition at a single heating run based on the Johnson-Mehl- Avrami (JMA) theory. In isochronal heating, the apparent activation energy for glass transition and crystallization events was analyzed by Kissinger and Ozawa methods. The average activation energy value for crystallization of TiZrHfNiCu amorphous alloys in isochronal modes was 226.41 kJ/mol for the first crystallization and 297.72 kJ/mol for second crystallization stages. The crystallization mechanism of the first step was dominated by two- and three-dimensional growth with increasing nucleation rate, while the crystallization mechanism in the second stage was dominated by two-dimensional crystallization growth with a constant nucleation rate. The diffusion mechanism result proved the theory of sluggish atomic diffusion of HEA at elevated temperature.","PeriodicalId":344331,"journal":{"name":"World Journal of Engineering and Technology","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130436933","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5

Research on the Construction Characteristics of Stone-Built Folk Houses in Jiarong Tibetan Area —Take the Stone-Built Houses in Xisuo Village as an Example 嘉荣藏区石屋民居建筑特征研究——以西所村石屋为例

World Journal of Engineering and Technology Pub Date : 2020-07-09 DOI: 10.4236/wjet.2020.83035

Xinwen Hou, B. Cheng

{"title":"Research on the Construction Characteristics of Stone-Built Folk Houses in Jiarong Tibetan Area —Take the Stone-Built Houses in Xisuo Village as an Example","authors":"Xinwen Hou, B. Cheng","doi":"10.4236/wjet.2020.83035","DOIUrl":"https://doi.org/10.4236/wjet.2020.83035","url":null,"abstract":"The Jiarong Tibetan traditional residence is a characteristic regional architecture, located in a high-intensity, high-altitude and cold area, with geographic identification, and is a typical representative of this ethnic group. It has also become an important tourist destination and has important research value. The research used the methods of field survey surveying and mapping to conduct field survey and surveying on 20 buildings in Xisuo Village, a traditional village in the Jiarong Tibetan area. Measure building plans, elevations, and building sections, and collect measurement data for statistical analysis. The results show that the average total height of the building is 10.08 m, the average total building span is 12.44 m, the average total depth is 10.87 m, and the squareness is 0.87. The square shape of the building is more in line with the seismic requirements of high-intensity areas and the local terrain environment. The maximum window-wall ratio in the building is 0.18 south for the second floor, and 0.025 west for the first floor. Smaller window-to- wall ratios have better adaptability to high-altitude cold areas. The height of the building beam section is generally from 0.17 m to 0.32 m, and the average Beam span-depth ratio is 0.10. The building space construction has a good match with the properties of wood materials. These conclusions quantitatively analyze the characteristics of stone-built houses in high-intensity, high-altitude and cold areas, supplement the research on ethnic regional architecture, and provide materials and references for the design, repair and update of related buildings.","PeriodicalId":344331,"journal":{"name":"World Journal of Engineering and Technology","volume":"63 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116583287","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Influence of Building Information Modelling (BIM) on Engineering Contract Management in Nairobi, Kenya 建筑信息模型(BIM)对肯尼亚内罗毕工程合同管理的影响

World Journal of Engineering and Technology Pub Date : 2020-07-09 DOI: 10.4236/wjet.2020.83026

Hellen Nyaboke Mosse, M. Njuguna, C. Kabubo

{"title":"Influence of Building Information Modelling (BIM) on Engineering Contract Management in Nairobi, Kenya","authors":"Hellen Nyaboke Mosse, M. Njuguna, C. Kabubo","doi":"10.4236/wjet.2020.83026","DOIUrl":"https://doi.org/10.4236/wjet.2020.83026","url":null,"abstract":"Building Information Modelling (BIM) is a technology and a process that has brought changes in the construction’s traditional procurement system. Kenya lacks contractual guidelines on implementation of BIM; this makes the adoption of BIM slow and difficult. Previous research has identified a gap in contractual relationships, roles and resulting risks. The objectives of this study were to investigate BIM adoption in Nairobi and to investigate the influence of BIM on Engineering Contract Management (ECM) in Nairobi Kenya. The survey research was a descriptive study with 175 responsive questionnaires. Respondents comprised of Civil Engineers, Construction Project Managers, Architects, Quantity Surveyors, Contractors and Facility Managers. Data was collected through self-administered questionnaire and in-depth interview. Descriptive analytics, correlation and Exploratory factor analysis methods were used to analyse quantitative data. Qualitative data was analysed thematically. It emerged that adoption level was at 56.6% and shallow understanding of BIM capabilities remains to be a barrier to its adoption and implementation. It also emerged that BIM improves ECM; when time, cost, quality, collaboration and return on investment improve, ECM becomes easier. Latent factors found in BIM and ECM relationship were Legal Implications, awareness and knowledge, efficiency, versatility, mandate and leadership, and competitiveness. Further, the study found out that BIM influence on ECM demands for establishment of standards, guidelines, policy, legal framework, and regulations, which can be achieved by amending the public procurement act which dictates the operation of all the other standard forms of contract. Further research should be conducted to measure whether the understanding of BIM had positively improved.","PeriodicalId":344331,"journal":{"name":"World Journal of Engineering and Technology","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124142176","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Effect of Bio-Disc on Distillate Yield and Crude Oil Properties 生物盘对馏分油收率和原油性质的影响

World Journal of Engineering and Technology Pub Date : 2020-07-09 DOI: 10.4236/wjet.2020.83028

A. Kerunwa, Princewill O. Ariche

{"title":"Effect of Bio-Disc on Distillate Yield and Crude Oil Properties","authors":"A. Kerunwa, Princewill O. Ariche","doi":"10.4236/wjet.2020.83028","DOIUrl":"https://doi.org/10.4236/wjet.2020.83028","url":null,"abstract":"The market worth of the crude oil transported to the international market has a great influence on the crude’s physical properties, as such demands that certain desirable physical properties ought to be possessed. The distillation of crude oil is the first process in the sequence of refining operation and is key to refinery operations profitability. In this work, five crude oil samples were collected from a reservoir in the Niger Delta designated as S11A, S12A, S13A, S14A and S15A. Sample S11A was not treated with bio-disc while samples S12A-S15A were treated with bio-disc at different number of times. This was necessary to ascertain the effect of the bio-disc on crude oil physical properties and their distillate yield. After the treatment, the specific gravity, American Petroleum Institute (API), pour point, flash point and viscosity of the treated and untreated crude samples were determined and then the samples distilled with a distillation tester. From the results obtained, the bio-disc had a great influence on the physical properties of the samples as well as on the distillate yield. The specific gravities of the oil samples decreased as the number of times the samples were treated with bio-disc increases and this in turn increased the crudes’ API. The pourpoint and viscosity decreased with increase in number of treatments of crude samples with bio-disc. As the number of treatments increased, the crude samples which were originally paraffinic were tending towards being naphthenic. The flash point and distillate yield increased with increase in number of treatments of crude samples with bio-disc. Thus, treatment of crude oil with bio-dic alters the physical properties of the crude.","PeriodicalId":344331,"journal":{"name":"World Journal of Engineering and Technology","volume":"77 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124284575","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Lance Design for Argon Bubbling in Molten Steel 钢水氩气鼓泡喷枪设计

World Journal of Engineering and Technology Pub Date : 2020-07-09 DOI: 10.4236/wjet.2020.83025

Servando De la Cruz, M. Barrón, D. Medina, Joan Reyes

引用次数: 1

Study on Pulp Grade of Iron Ore Concentrate by Monte Carlo 用蒙特卡罗法研究铁矿精矿矿浆品位

World Journal of Engineering and Technology Pub Date : 2020-07-09 DOI: 10.4236/wjet.2020.83029

Jie Xu, Jiawen Fan, Changming Wang, Yujie Qiao

引用次数: 0

Research on Logistics Demand Forecast in Southeast Asia 东南亚地区物流需求预测研究

World Journal of Engineering and Technology Pub Date : 2020-07-09 DOI: 10.4236/wjet.2020.83020

Thi Hai Yen Nguyen

引用次数: 4

Rock Slope Stability Analysis by Using Integrated Approach 岩质边坡稳定性综合分析

World Journal of Engineering and Technology Pub Date : 2020-07-09 DOI: 10.4236/wjet.2020.83031

D. Moses, H. Shimada, T. Sasaoka, A. Hamanaka, T. Dintwe, Sugeng Wahyudi

{"title":"Rock Slope Stability Analysis by Using Integrated Approach","authors":"D. Moses, H. Shimada, T. Sasaoka, A. Hamanaka, T. Dintwe, Sugeng Wahyudi","doi":"10.4236/wjet.2020.83031","DOIUrl":"https://doi.org/10.4236/wjet.2020.83031","url":null,"abstract":"Slope stability assessment is an essential aspect of mining and civil engineering. In this study, Songwe open-pit mine in Malawi was investigated to establish possible pit slope instability. In performing the analysis, an integrated approach entailing rock mass characterisation, kinematic and numerical methods were applied. Based on rock mass classification system, Songwe Hill carbonatite rock mass is characterised as a good rock but still it possesses numerous random discontinuities that present a complex challenge in geotechnical engineering. Dip 6.0 software was used in carrying out kinematic analysis based on the attributes of discontinuities. The results show that there is a 16% likelihood of planar failure in the divided slope sections of the planned pit. Thus, slope angle optimisation to 41° has been proposed as a counter-measure to minimise the potential risk of planar failure. At the optimised angle, the risk of planar failure could be reduced by 44%. On the other hand, wedge failure was found to be improbable since no joint intersections were found in the critical zone of potential failure. For numerical analysis, finite element code was applied using FLAC3D 5.0 application. The results demonstrate that overall slope angle of 41° would offer a favourable balance between safety and mining economics as mining operations progress to deeper horizons thereby avoiding a costly push back solution due to instability.","PeriodicalId":344331,"journal":{"name":"World Journal of Engineering and Technology","volume":"16 12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126165353","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Reliability of the MPPT Control on the Energy Parameters of a Photovoltaic Generator 光伏发电机组能量参数MPPT控制的可靠性研究

World Journal of Engineering and Technology Pub Date : 2020-07-09 DOI: 10.4236/wjet.2020.83038

Batassou Guilzia Jeannot, Mandeng Jean Jacques, Mane Mane Jeannot

引用次数: 1

Experimental Study on Mechanical Properties of Q345 Steel after High Temperature Cooling Q345钢高温冷却后力学性能的试验研究

World Journal of Engineering and Technology Pub Date : 2020-07-09 DOI: 10.4236/wjet.2020.83021

Feiyan Zhu, Yu Zhang, C. Zhang

引用次数: 0