JST: Engineering and Technology for Sustainable Development最新文献_第3页

Stability and Hopf Bifurcation Analysis of a Phytoplankton-Zooplankton Model Under Temperature Factor and Stage-Structure Population of Phytoplankton 温度因子和浮游植物阶段结构种群下浮游植物-浮游动物模型的稳定性和Hopf分岔分析

JST: Engineering and Technology for Sustainable Development Pub Date : 2023-11-15 DOI: 10.51316/jst.170.etsd.2023.33.5.7

引用次数: 0

Effects of Hybrid Diffuser in Axial-Flow Jet Engine Combustor 混合扩散器在轴流喷气发动机燃烧室中的作用

JST: Engineering and Technology for Sustainable Development Pub Date : 2023-11-15 DOI: 10.51316/jst.170.etsd.2023.33.5.1

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Removal of Methylene Blue Intensified Ozonation Using a High-Performance Rotating Reactor 高性能旋转反应器强化臭氧氧化去除亚甲基蓝

JST: Engineering and Technology for Sustainable Development Pub Date : 2023-11-15 DOI: 10.51316/jst.170.etsd.2023.33.5.3

{"title":"Removal of Methylene Blue Intensified Ozonation Using a High-Performance Rotating Reactor","authors":"","doi":"10.51316/jst.170.etsd.2023.33.5.3","DOIUrl":"https://doi.org/10.51316/jst.170.etsd.2023.33.5.3","url":null,"abstract":"The advanced oxidation processes (AOPs) were commonly used in textile dyeing wastewater treatment due to its ability to rapidly degrade dyed compounds. However, its disadvantage is the limited dispersion of ozone in wastewater. To minimize the disadvantage, it is necessary to improve the gas-liquid phase contact to maximize the dispersion of ozone in the wastewater body. Therefore, this study investigated the methylene blue (MB) treatment efficiency in textile dyeing wastewater by performing the ozonation process using a high-performance rotating reactor (HP2R) and compared it with the conventional system. The effect of basic operation parameters such as initial pH, initial methylene blue concentration (Co), rotational speed (ω), and the liquid flow rate (QL) on the decolorization efficiency (η) was evaluated. The results showed that the η of the ozonation using the HP2R reached 98% (pH 8) after only 5 minutes, which was 1.8 times higher than that (54%) of conventional ozonation at the identical period. The decolorization efficiency increased with increasing rotational speed (from 82.0 to 92.5% as ω increased from 30 to 1200 rpm), decreasing liquid flow rate (from 98.0 to 74.9% as QL increased from 0.1 to 0.4 l/min) and decreasing initial concentration of MB (from 98.0 to 88.5% as Co increased from 50 to 200 mg/l). These results show that the combined ozonation in the high-gravity technology can be widely applied to various dyeing wastewater treatment processes in general.","PeriodicalId":17641,"journal":{"name":"JST: Engineering and Technology for Sustainable Development","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136228655","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

Evaluating the Energy Efficiency and Environmental Impact of a Multi-Chamber Brick Kiln in Vietnam 评估越南多室砖窑的能源效率和环境影响

JST: Engineering and Technology for Sustainable Development Pub Date : 2023-11-15 DOI: 10.51316/jst.170.etsd.2023.33.5.8

引用次数: 0

Effect of Nozzle Travel Path Strategies on the Mechanical Properties of Inconel 625 Superalloy Parts Formed by Direct Laser Metal Deposition 喷嘴行程路径策略对激光直接沉积Inconel 625高温合金零件力学性能的影响

JST: Engineering and Technology for Sustainable Development Pub Date : 2023-11-15 DOI: 10.51316/jst.170.etsd.2023.33.5.2

{"title":"Effect of Nozzle Travel Path Strategies on the Mechanical Properties of Inconel 625 Superalloy Parts Formed by Direct Laser Metal Deposition","authors":"","doi":"10.51316/jst.170.etsd.2023.33.5.2","DOIUrl":"https://doi.org/10.51316/jst.170.etsd.2023.33.5.2","url":null,"abstract":"To reduce the occurrence of cracks in the Inconel 625 nickel-based super-alloy during the Direct Laser Metal Deposition (DLMD) process, this study simulated the temperature and stress fields of thin-walled parts. The model was used to determine the effect of nozzle travel path strategies (single direction and reverse direction) on the final stress distribution, and compared the differences in residual stress distribution within the thin-walled part. The results showed that with the single direction scanning method, the residual stress at both ends of the thin-walled part was relatively high while the stress at the middle was smaller, with a stress difference between the maximum and minimum of about 900 MPa. In contrast, with the reverse direction scanning method, the residual stress in the thin-walled part was distributed relatively evenly, with a stress difference of about 300 MPa between both ends and the center. The experimental results showed that with the single direction scanning method, cracks occurred at both ends and in the middle of the thin-walled part, whereas with the reverse direction scanning method, warping and cracks phenomena were eliminated. The microstructure of the Inconel 625 in the forming layer is characterized by a columnar crystal structure that has a small length and grows perpendicularly to the scanning direction. This growth is continuous between the forming layers. In both cases, the micro-hardness increases with the height of the formed layers; the microhardness values in the left, right, and middle regions are relatively uniform, the microhardness measurement values range from 420 to 450 HV.","PeriodicalId":17641,"journal":{"name":"JST: Engineering and Technology for Sustainable Development","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136228653","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

First-Principles Study of Electronic and Optical Properties and Photocatalytic Performance of MS Monolayer under Strain 应变作用下质谱单层膜的电子光学性质和光催化性能的第一性原理研究

JST: Engineering and Technology for Sustainable Development Pub Date : 2023-04-15 DOI: 10.51316/jst.165.etsd.2023.33.2.7

引用次数: 0

Effect of Nitrogen Sources and Illumination Conditions on Ganoderma lucidum Submerged Culture 氮源和光照条件对灵芝深层培养的影响

JST: Engineering and Technology for Sustainable Development Pub Date : 2023-04-15 DOI: 10.51316/jst.165.etsd.2023.33.2.3

引用次数: 0

Researching Electronic System of the SC-920 Control Circuit of the DDL-8700-7 Single Needle Sewing Machine and Application DDL-8700-7单针缝纫机SC-920控制电路电子系统的研究及应用

JST: Engineering and Technology for Sustainable Development Pub Date : 2023-04-15 DOI: 10.51316/jst.165.etsd.2023.33.2.9

引用次数: 0

Batch Furnace Chemical Vapor Deposition of Pure Boron Layers on Si and GaN Substrates for Low-Leakage-Current Diode Fabrication 在硅和氮化镓衬底上分批炉化学气相沉积纯硼层用于低漏电流二极管的制造

JST: Engineering and Technology for Sustainable Development Pub Date : 2023-04-15 DOI: 10.51316/jst.165.etsd.2023.33.2.5

{"title":"Batch Furnace Chemical Vapor Deposition of Pure Boron Layers on Si and GaN Substrates for Low-Leakage-Current Diode Fabrication","authors":"","doi":"10.51316/jst.165.etsd.2023.33.2.5","DOIUrl":"https://doi.org/10.51316/jst.165.etsd.2023.33.2.5","url":null,"abstract":"Boron deposition on both n-Si and n-GaN in the temperature range 250 - 500 °C, has been shown to form diodes with low saturation currents, i.e., electron injection from the n-substrate into the B-layer was efficiently suppressed. Moreover, down to 3-nm-thick B-layers on Si were shown to form a material barrier to Al, opening the possibility of fabricating Au-free gates for gallium-nitride high-electron-mobility transistors (GaN HEMTs). Several different chemical- and physical-vapor deposition (CVD/PVD) methods for depositing B have been studied for fabricating p+n-like Si diodes, called PureB diodes, all with comparable results. In this paper, the deposition of B-layers from diborane in a CVD batch furnace system is evaluated, particularly for use as a barrier material to enable Al-contacting of GaN diodes. These Al-B diodes could provide an option for fabricating low-leakage diodes that are compatible with complementary metal-oxide-semiconductor (CMOS) processing at industrially attractive high throughput. The bulk B has high resistivity, which, combined with the fact that non-uniformities in the nm range, are typical due to gas depletion along the furnace tube and gives uncontrollable, often high diode series resistance. A simulation study shows that Al-B could, nevertheless, be used as a gate stack in HEMTs for low-frequency power applications.","PeriodicalId":17641,"journal":{"name":"JST: Engineering and Technology for Sustainable Development","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81653816","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

Effect of Copper on the Grain Size and Tensile Strength of Ultra-Low Carbon Steel 铜对超低碳钢晶粒尺寸和抗拉强度的影响

JST: Engineering and Technology for Sustainable Development Pub Date : 2023-04-15 DOI: 10.51316/jst.165.etsd.2023.33.2.6

{"title":"Effect of Copper on the Grain Size and Tensile Strength of Ultra-Low Carbon Steel","authors":"","doi":"10.51316/jst.165.etsd.2023.33.2.6","DOIUrl":"https://doi.org/10.51316/jst.165.etsd.2023.33.2.6","url":null,"abstract":"The paper presents a study on the grain size and tensile strength of annealed ultra-low carbon (ULC) steel containing 0.008 wt.% carbon (C) and various contents of copper (Cu). The annealing temperature was predetermined at 700, 800, and 900 C with the same holding time of 15 minutes and a slow cooling rate. The microstructural result showed that the ferritic grain size of the steel increased with the annealing temperature, e.g. increased to 60 and 65 µm when the temperature raised to 900 C for the 0.112 and 0.285 wt.% Cu steel, respectively. This phenomenon was attributed to the recrystallization of the steel during the annealing process. The coarser grains resulted in a decrease in the tensile strength of the steel despite that the tensile strength of the steel was found to improve with the increased Cu content. The low tensile strengths and good elongation remained in the ULC steel, for instance, the ultimate tensile strength stayed in the range of 234-350 MPa and the elongation remained in the range of 22-35 % dependent on the annealed temperature, and the Cu content. The results show that the content of Cu less than 0.3 wt.% did not have a negative effect on the tensile strength of the studied steel, but caused a deteriorated elongation of the steels annealed at 900 C.","PeriodicalId":17641,"journal":{"name":"JST: Engineering and Technology for Sustainable Development","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90100644","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