Vietnam Journal of Science and Technology最新文献_第5页

Synthesis and characterization of PMMA-grafted-ZrO2 hybrid nanoparticles PMMA 接枝-ZrO2 混合纳米粒子的合成与表征

Vietnam Journal of Science and Technology Pub Date : 2023-12-15 DOI: 10.15625/2525-2518/16991

Linh Nguyen Thi Dieu, Dung Nguyen Thi Kim, Thang Dam Xuan, Tham Do Quang

{"title":"Synthesis and characterization of PMMA-grafted-ZrO2 hybrid nanoparticles","authors":"Linh Nguyen Thi Dieu, Dung Nguyen Thi Kim, Thang Dam Xuan, Tham Do Quang","doi":"10.15625/2525-2518/16991","DOIUrl":"https://doi.org/10.15625/2525-2518/16991","url":null,"abstract":"In this study, we reported a facile synthesis and the characterization of PMMA-grafted ZrO2 hybrid nanoparticles from original ZrO2 (oZrO2) nanoparticles. The synthesis process included of three steps: (i) modification of nano ZrO2 with a vinyl silane agent, (ii) graft copolymerization of methyl methacrylate (MMA) monomers and modified ZrO2 (mZrO2) nanoparticles, and (iii) extraction of homo PMMA to obtain the final product of PMMA-g-ZrO2 (gZrO2) nanoparticles. Fourier transform infrared (FTIR) spectra and thermogravimetric analysis (TGA) of mZrO2, oZrO2, and gZrO2 indicated that the silane coupling agent was grafted onto oZrO2 nanoparticles. FTIR spectra of gZrO2 indicated PMMA had been successfully grafted onto the surface of ZrO2 nanoparticles. Using TGA method, the PMMA grafting content onto ZrO2 nanoparticles was evaluated as 9.03 wt.%. The electron microscopy (SEM) images of gZrO2, mZrO2, and oZrO2 indicated that their primary particle size and shape were almost unchanged after modification processes, their particle size was in the range from 50 nm to 140 nm. XRD analysis showed the monoclinic crystalline structure of three kinds of ZrO2 nanoparticles (nanocrystals). The organic gZrO2 nanoparticles can be a better candidate as an opacifier additive for polymer nanocomposites or acrylic bone cement.","PeriodicalId":23553,"journal":{"name":"Vietnam Journal of Science and Technology","volume":"70 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138997685","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

Modelling carbon dioxide gas emission from Notopterus chitala fish ponds by stella software 利用 stella 软件模拟鳙鱼池塘的二氧化碳气体排放

Vietnam Journal of Science and Technology Pub Date : 2023-12-15 DOI: 10.15625/2525-2518/16746

Van So Nguyen, Anh Tuan Le

{"title":"Modelling carbon dioxide gas emission from Notopterus chitala fish ponds by stella software","authors":"Van So Nguyen, Anh Tuan Le","doi":"10.15625/2525-2518/16746","DOIUrl":"https://doi.org/10.15625/2525-2518/16746","url":null,"abstract":"The rapid development of the areas of Notopterus chitala fish ponds in Hau Giang province in recent years has raised a question about greenhouse gas emissions, in the form of total carbon dioxide equivalents (CO2e). There are many parameters that affect greenhouse gas emissions in a fish pond, such as amount of feed, dissolved oxygen (DO), chemical oxygen demand (COD) in the water, pH, water temperature, windy velocity and sunlight reaching the pond surface. In this study, a System Thinking, Experimental Learning Laboratory with Animation, shortly called as Stella is applied as a visual programming language for system dynamics modelling in order to find the relationship between simulated CO2 and measured CO2 in Notopterus chitala fish pond. Three ponds were used for measuring average pH, temperature, feeds, DO, COD and phytoplankton inside the ponds while windy speed and light intensity data were collected from a Weather Station nearby. The results of model calibration and validation showed that the Stella 8.0 can be used as predictable tool for the change in time of CO2 emission during 240 days of fishing. Model can help fishing farmers to adjust the quantity of feeds and control the water quality in their Notopterus chitala fish ponds to reduce greenhouse gas emissions appropriately.","PeriodicalId":23553,"journal":{"name":"Vietnam Journal of Science and Technology","volume":"12 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139001111","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

Eco-friendly method of biocementation for soil improvement and environmental remediation in the context of Viet Nam: a state-of-the-art review 在越南采用生态友好型生物固化法进行土壤改良和环境修复：最新进展综述

Vietnam Journal of Science and Technology Pub Date : 2023-12-15 DOI: 10.15625/2525-2518/18516

Ngoc Tri Huynh Nguyen, Pham Huong Huyen Nguyen, Hoang Thien Khoi Nguyen, Khanh Son Nguyen

{"title":"Eco-friendly method of biocementation for soil improvement and environmental remediation in the context of Viet Nam: a state-of-the-art review","authors":"Ngoc Tri Huynh Nguyen, Pham Huong Huyen Nguyen, Hoang Thien Khoi Nguyen, Khanh Son Nguyen","doi":"10.15625/2525-2518/18516","DOIUrl":"https://doi.org/10.15625/2525-2518/18516","url":null,"abstract":"Scientists have been using microorganisms to improve soil strength and durability through a process called biocementation. This technique involves inducing mineral precipitation to form a cement-like material that enhances soil properties. Biocementation has been successful in various applications, including soil stabilization, erosion control, and groundwater remediation. Researchers are optimizing nutrient concentrations and ratios to create a favorable environment for microbial activity and promote efficient mineral formation. Different microorganisms have varying abilities to induce mineralization, and cycle treatments have shown promise in stimulating biomineralization processes. Biocementation is a sustainable and eco-friendly technique that can stabilize and immobilize contaminants in soil and groundwater, preventing the spread of pollutants. Despite these challenges, biocementation holds great potential for innovative soil improvement and environmental remediation. Recent studies, experiments, testing devices, and results from research groups in the world and Vietnam in recent years were reviewed to gain insight into this promising approach. Ongoing research aims to develop cost-efficient and sustainable methods for large-scale production and application of biocementing agents. Further research is needed to uncover the intricate mechanisms and identify optimal strategies for applications and environmental conditions.","PeriodicalId":23553,"journal":{"name":"Vietnam Journal of Science and Technology","volume":"73 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138997681","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

Optical properties of circular photonic crystal fibers filled with carbon tetrachloride 填充四氯化碳的环形光子晶体光纤的光学特性

Vietnam Journal of Science and Technology Pub Date : 2023-12-15 DOI: 10.15625/2525-2518/17045

Hoang Trong Duc, Le Tran Bao Tran, Tran Ngoc Thao, C. V. Lanh, Nguyen Thi Thuy

引用次数: 0

Assessment of the role of ACC deaminase, IAA, and siderophore-producing bacteria isolated from Spratly Islands on the growth of Brassica juncea on the coral sand 评估从南沙群岛分离的 ACC 脱氨酶、IAA 和产苷细菌对珊瑚沙上甘蓝菜生长的作用

Vietnam Journal of Science and Technology Pub Date : 2023-11-20 DOI: 10.15625/2525-2518/18867

Vu Thi Quynh Chi, Nguyen Viet Hiep, Le Thi My Hao, Nguyen Quang Hai, Do Thi Kim Anh, Huong Pham, Than Van Hau, Nguyen Cong Viet, Ngo Thi Xinh, Nguyen Thi Loi, Bui Dang Thanh

{"title":"Assessment of the role of ACC deaminase, IAA, and siderophore-producing bacteria isolated from Spratly Islands on the growth of Brassica juncea on the coral sand","authors":"Vu Thi Quynh Chi, Nguyen Viet Hiep, Le Thi My Hao, Nguyen Quang Hai, Do Thi Kim Anh, Huong Pham, Than Van Hau, Nguyen Cong Viet, Ngo Thi Xinh, Nguyen Thi Loi, Bui Dang Thanh","doi":"10.15625/2525-2518/18867","DOIUrl":"https://doi.org/10.15625/2525-2518/18867","url":null,"abstract":"Root endophytic and rhizosphere bacteria play a significant role in enhancing plant tolerance and promoting growth by producing 1-aminocyclopropane-1-carboxylate (ACC) deaminase, indole-3-acetic acid (IAA), and siderophore. These bacteria have been isolated and screened from 45 plants’ roots and rhizosphere soil samples of 19 types of plants which are growing on 8 floating islands in Spratley Islands, Viet Nam. In which, 3 root endophytic bacteria strains were selected and identified to be Agrobacterium tumefaciens, Pseudomonas plecoglossicida, and Klebsiella aerogenes from roots of Scaevola taccada, Barringtonia asiatica (L.) Kurz, and Carica papaya, respectively. Correspondingly, 3 rhizosphere bacteria strains were selected and identified to be Bacillus velezensis, Bacillus aryabhattai, and Bacillus velezensis from rhizosphere soils of Canavalia maritima (Aubt) Thouars (C. obtusifolia DC.), Cucumis sativus, Heliotropium foertherianum, respectively. These strains were found could increase the germination rate of Brassica juncea’s seeds and 20-day-old fresh biomass, compared to the control treatment in the same condition of 10‰ saline watering. When these bacterial strains were combined as an inoculant, they indicated the same result on coral sand. Thus, the addition of selected endophytic and rhizosphere bacteria is efficient in improving the coral sand environment to enhance food crops’ development in the Spratly Islands.","PeriodicalId":23553,"journal":{"name":"Vietnam Journal of Science and Technology","volume":"37 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139257411","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

Heterotrophic nitrifying bacteria from activated sludge in DHS reactor for ammonium removal of natural rubber processing wastewater treatment DHS 反应器中活性污泥的异养硝化细菌用于天然橡胶加工废水处理的氨去除

Vietnam Journal of Science and Technology Pub Date : 2023-10-20 DOI: 10.15625/2525-2518/17141

Tran Minh Duc, Phan Thi Thanh Thuy, Nguyen Thi Huyen, Nguyen Lan Huong

引用次数: 0

Studies on hepatoprotective effects of Vietnamese medicinal plants 越南药用植物的保肝作用研究

Vietnam Journal of Science and Technology Pub Date : 2023-10-20 DOI: 10.15625/2525-2518/17426

Ngoc Khanh Pham, Katarina Bauerova, Nguyen Manh Cuong

引用次数: 0

Antioxidant, angiotensin converting enzyme inhibitory and anthelmintic activities of bark essential oil of Cinnamomum bejolghota (Buch.-Ham.) Sweet from North East India 印度东北部 Cinnamomum bejolghota (Buch.-Ham.) Sweet 树皮精油的抗氧化、血管紧张素转换酶抑制和驱虫活性

Vietnam Journal of Science and Technology Pub Date : 2023-10-20 DOI: 10.15625/2525-2518/17346

B. Gogoi, K. J. Tamuli, Snigdha Saikia, Neipihoi Lhouvum, M. Bordoloi, Hemanta K. Sarma

{"title":"Antioxidant, angiotensin converting enzyme inhibitory and anthelmintic activities of bark essential oil of Cinnamomum bejolghota (Buch.-Ham.) Sweet from North East India","authors":"B. Gogoi, K. J. Tamuli, Snigdha Saikia, Neipihoi Lhouvum, M. Bordoloi, Hemanta K. Sarma","doi":"10.15625/2525-2518/17346","DOIUrl":"https://doi.org/10.15625/2525-2518/17346","url":null,"abstract":"Cinnamomum bejolghota (Buch.-Ham.) Sweetisa traditional anthelmintic and cardiotonic medicinal plant. The essential oil extracted from the bark of C. bejolghota was characterized by gas chromatography-mass spectrometry and 28 constituents were identified. Monoterpenoids were found to be dominating chemical constituents with α-terpineol (18.57 %) as the major component of the essential oil. The antioxidant activity of the essential oil was evaluated by DPPH radical, β-carotene bleaching and reducing power assay methods. The essential oil showed in-vitro dose-response hindering activity against angiotensin-converting enzyme with an IC50 value of 33.43 ± 0.46 µg/mL.The essential oil also exhibited potent anthelmintic property in-vitro against Caenorhabditis elegans with an ED50value of 80.53 ± 3.57 µg/mLin adult mortality assay. The inhibitory activity of essential oil against larval development assay showed an ED50value of 72.40 ± 2.68 µg/mL against C. elegans larva. Further, the egg hatching assay using C. eleganseggs demonstrated an ED50 value of 68.27 ± 3.51 µg/mL with this essential oil. Thus, the ethnomedicinal claim has been validated for the bark essential oil, which provides an excellent scope for the development of the C. bejolghota bark essential oil as novel herbal antihypertensive and anthelmintic agents.","PeriodicalId":23553,"journal":{"name":"Vietnam Journal of Science and Technology","volume":"111 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139316163","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

Fracture analysis in 2D plane strain problems for composite materials containing hard inclusions and voids using an extended consecutive-interpolation quadrilateral element 使用扩展连续插值四边形元素分析含有硬夹杂物和空隙的复合材料二维平面应变问题中的断裂分析

Vietnam Journal of Science and Technology Pub Date : 2023-10-20 DOI: 10.15625/2525-2518/18456

Binh Hai Hoang, V. S. Lo, B. Tran, T. T. Truong

{"title":"Fracture analysis in 2D plane strain problems for composite materials containing hard inclusions and voids using an extended consecutive-interpolation quadrilateral element","authors":"Binh Hai Hoang, V. S. Lo, B. Tran, T. T. Truong","doi":"10.15625/2525-2518/18456","DOIUrl":"https://doi.org/10.15625/2525-2518/18456","url":null,"abstract":"This paper investigates fracture mechanics in particle-reinforced composites by using the extended finite element method enhanced by the consecutive-interpolation quadrilateral element. These composite materials have discontinuous boundaries such as cracks, voids, holes, and soft inclusions. And the extended consecutive-interpolation quadrilateral element (XCQ4) is employed to model these boundaries in two-dimensional linear elastic deformation problems. XCQ4 combines the enrichment functions in the traditional extended finite element method with the consecutive interpolation on a 4-node quadrilateral element. This element uses both nodal values and averaged nodal gradients as interpolated conditions. In fracture analysis, the stress intensity factors (SIFs) are important parameters that must be defined. In this study, the values of SIFs at the crack tips are evaluated with the help of the interaction integrals approach. The obtained numerical results are compared with other reliable results showing high accuracy and convergence rate of the XCQ4 element.","PeriodicalId":23553,"journal":{"name":"Vietnam Journal of Science and Technology","volume":"54 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139315942","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

A study on mechanical properties of 1H-type crystalline nickel ditelluride 关于 1H 型结晶二碲化镍机械特性的研究

Vietnam Journal of Science and Technology Pub Date : 2023-10-20 DOI: 10.15625/2525-2518/17619

Nguyen Danh, Truong, Nguyen Van Quynh

引用次数: 0