Pub Date : 2024-02-23DOI: 10.15625/2525-2518/19438
Nguyen Thuy Chinh, T. Hoang
Collagen is a natural protein presenting in the animal and human’s body. It is in natural fibrous and could be found in the connective tissue and flesh of mammal, approximately 25-35 wt.% of total human protein. Collagen is abundant in fibrous tissues such as: bones, cartilage, tendons, blood vessels, ligaments, skin, cornea, aortic disc and intestines. Fish collagen is currently being studied as a new biological substitute for collagen from animals. It extracted from by-products (scales, skins, bones, etc.) by biochemical or biological methods is safe, has high adsorption, high compatible. The factors influencing on the extraction process include temperature, time, concentration of ingredients, etc. The fish collagen is usually collagen type I with a fibril structure. Each unit of collagen is tropocollagen consisting of three polypeptide chains twisted together. Depending on the source of ingredients, the composition of aminoacids, denaturation temperature, the sequence of aminoacids, structure, morphology, molecular weight, extraction yield, etc. of obtained collagens are different. This paper reviews the extraction and characterization of fish collagen from products after fish processing by chemical or biochemical methods. The applications of fish collagen in wound healing and drug delivery are also reviewed.
胶原蛋白是一种存在于动物和人体中的天然蛋白质。它呈天然纤维状，存在于哺乳动物的结缔组织和肉中，约占人体蛋白质总量的 25-35%。胶原蛋白在骨骼、软骨、肌腱、血管、韧带、皮肤、角膜、主动脉椎间盘和肠道等纤维组织中含量丰富。鱼胶原蛋白目前正被研究用作动物胶原蛋白的新生物替代品。它通过生化或生物方法从副产品（鱼鳞、鱼皮、鱼骨等）中提取，具有安全、高吸附性、高兼容性等特点。影响提取过程的因素包括温度、时间、成分浓度等。鱼胶原蛋白通常是具有纤维结构的 I 型胶原蛋白。每个胶原蛋白单位都是由三条多肽链缠绕在一起的滋养胶原蛋白。由于原料来源不同，所得胶原蛋白的氨基酸组成、变性温度、氨基酸序列、结构、形态、分子量、提取率等也不同。本文综述了通过化学或生化方法从鱼类加工后的产品中提取鱼胶原蛋白及其特征。本文还综述了鱼胶原蛋白在伤口愈合和药物输送方面的应用。
{"title":"Review: fish collagen: extraction, characterization and application in wound healing and drug delivery","authors":"Nguyen Thuy Chinh, T. Hoang","doi":"10.15625/2525-2518/19438","DOIUrl":"https://doi.org/10.15625/2525-2518/19438","url":null,"abstract":"Collagen is a natural protein presenting in the animal and human’s body. It is in natural fibrous and could be found in the connective tissue and flesh of mammal, approximately 25-35 wt.% of total human protein. Collagen is abundant in fibrous tissues such as: bones, cartilage, tendons, blood vessels, ligaments, skin, cornea, aortic disc and intestines. Fish collagen is currently being studied as a new biological substitute for collagen from animals. It extracted from by-products (scales, skins, bones, etc.) by biochemical or biological methods is safe, has high adsorption, high compatible. The factors influencing on the extraction process include temperature, time, concentration of ingredients, etc. The fish collagen is usually collagen type I with a fibril structure. Each unit of collagen is tropocollagen consisting of three polypeptide chains twisted together. Depending on the source of ingredients, the composition of aminoacids, denaturation temperature, the sequence of aminoacids, structure, morphology, molecular weight, extraction yield, etc. of obtained collagens are different. This paper reviews the extraction and characterization of fish collagen from products after fish processing by chemical or biochemical methods. The applications of fish collagen in wound healing and drug delivery are also reviewed.","PeriodicalId":23553,"journal":{"name":"Vietnam Journal of Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140437599","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}
Pub Date : 2024-02-23DOI: 10.15625/2525-2518/17906
Do T. Phuong, N. M. Anh, Nguyen Thi Nga, Vu Thi Thu Huyen, N. Cuc, Trieu H. Phuong, Le Thi Hong Minh, Do Thi Thao
Currently, L-asparaginase isolated from terrestrial microorganisms has been employed for anticancer industrial production. This enzyme has the function of inhibiting the growth of acute lymphoblastic leukemia, Hodgkin's lymphomas and other cancers. In this study, for the first time, L-asparaginase (ASNase) productive capacity of forty marine bacteria originating from Khanh Hoa sea of Viet Nam was screened and reported. Among those, twenty eight isolates were clarified for their extracellular ASNase activity based on their ability to form a pink zone around colonies on asparagine agar plates. As a result, four strains GB910, GB911, GB976 and GB982 showed high secreted extracellular ASNase activity, ranging from 8.64 to 13.22 IU/mg. Among these four most potential strains, GB911 exhibited better enzyme production capacity and was subjected to taxonomy identification. According to the 16S rRNA gene sequence on the GenBank database, strain GB911 was identified as Priestia megaterium and registered in the GenBank database with accession number MW407014. The purified enzyme obtained from strain GB911 exhibited strong cytotoxic activity against five monolayer and suspension cancerous cell lines with IC50 values ranging from 39 mU/mL to 98 mU/mL. The strain could serve as a promising source for industrial production of ASNase for clinical chemotherapeutic treatment.
{"title":"Extracellular L-asparaginase productive potential of the Priestia megaterium strain GB911 from Khanh Hoa sea of Viet Nam","authors":"Do T. Phuong, N. M. Anh, Nguyen Thi Nga, Vu Thi Thu Huyen, N. Cuc, Trieu H. Phuong, Le Thi Hong Minh, Do Thi Thao","doi":"10.15625/2525-2518/17906","DOIUrl":"https://doi.org/10.15625/2525-2518/17906","url":null,"abstract":"Currently, L-asparaginase isolated from terrestrial microorganisms has been employed for anticancer industrial production. This enzyme has the function of inhibiting the growth of acute lymphoblastic leukemia, Hodgkin's lymphomas and other cancers. In this study, for the first time, L-asparaginase (ASNase) productive capacity of forty marine bacteria originating from Khanh Hoa sea of Viet Nam was screened and reported. Among those, twenty eight isolates were clarified for their extracellular ASNase activity based on their ability to form a pink zone around colonies on asparagine agar plates. As a result, four strains GB910, GB911, GB976 and GB982 showed high secreted extracellular ASNase activity, ranging from 8.64 to 13.22 IU/mg. Among these four most potential strains, GB911 exhibited better enzyme production capacity and was subjected to taxonomy identification. According to the 16S rRNA gene sequence on the GenBank database, strain GB911 was identified as Priestia megaterium and registered in the GenBank database with accession number MW407014. The purified enzyme obtained from strain GB911 exhibited strong cytotoxic activity against five monolayer and suspension cancerous cell lines with IC50 values ranging from 39 mU/mL to 98 mU/mL. The strain could serve as a promising source for industrial production of ASNase for clinical chemotherapeutic treatment.","PeriodicalId":23553,"journal":{"name":"Vietnam Journal of Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140437066","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}
Pub Date : 2024-02-23DOI: 10.15625/2525-2518/18622
Sergei Alexandrov, Marina I. Rynkovskaya, Ismet Bajmuratov, Ruslan Kalistratov, Ivan Pylkin
The present paper develops a new failure analysis method under plane strain conditions considering a generalized linear yield criterion. The yield criterion and the stress equilibrium equations constitute a hyperbolic system of equations. It is shown that two auxiliary variables satisfy the equation of telegraphy. Simple analytical relationships connect these variables and the radii of curvature of the characteristic curves. The calculated radii of curvature allow for the corresponding characteristic net to be constructed. Then, the stress field is determined using another set of analytical relationships. Thus, a numerical procedure is only necessary for solving the equation of telegraphy. This equation can be integrated by the method of Riemann. In particular, Green’s function is the Bessel function of zero order. A simple example illustrates the general method.
{"title":"A new method of failure analysis","authors":"Sergei Alexandrov, Marina I. Rynkovskaya, Ismet Bajmuratov, Ruslan Kalistratov, Ivan Pylkin","doi":"10.15625/2525-2518/18622","DOIUrl":"https://doi.org/10.15625/2525-2518/18622","url":null,"abstract":"The present paper develops a new failure analysis method under plane strain conditions considering a generalized linear yield criterion. The yield criterion and the stress equilibrium equations constitute a hyperbolic system of equations. It is shown that two auxiliary variables satisfy the equation of telegraphy. Simple analytical relationships connect these variables and the radii of curvature of the characteristic curves. The calculated radii of curvature allow for the corresponding characteristic net to be constructed. Then, the stress field is determined using another set of analytical relationships. Thus, a numerical procedure is only necessary for solving the equation of telegraphy. This equation can be integrated by the method of Riemann. In particular, Green’s function is the Bessel function of zero order. A simple example illustrates the general method.","PeriodicalId":23553,"journal":{"name":"Vietnam Journal of Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140436436","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}
Pub Date : 2024-02-23DOI: 10.15625/2525-2518/18788
E. Ermakova, Marina I. Rynkovskaya
The article is devoted to the shape optimization of shell structures in Comsol Multiphysics using three gradient-based methods: IPOPT (Interior Point OPTimizer), SNOPT (Sparse Nonlinear OPTimizer) and MMA or GCMMA (the Method of Moving Asymptotes). Two types of complex shapes, such as right helicoid and developable helicoid are taken for the computational experiment. The task is to investigate the initial design and optimization process of two helicoids. To obtain a more accurate result and an interesting design solution, the calculation is carried out using three physics-controlled mesh sizes: extra coarse, fine and extra fine with varying values of special optimization settings, such as maximum displacement (dmax) and filter radius (Rmin). The results obtained using the three methods allow to conclude that the mesh element size and studied parameters dmax and Rmin have a significant impact on the final optimization result.
文章主要介绍了在 Comsol Multiphysics 中使用三种基于梯度的方法对壳结构进行形状优化：IPOPT (Interior Point OPTimizer)、SNOPT (Sparse Nonlinear OPTimizer) 和 MMA 或 GCMMA (the Method of Moving Asymptotes)。计算实验采用了两种类型的复杂形状，如右螺旋形和可展开螺旋形。任务是研究两种螺旋形的初始设计和优化过程。为了获得更精确的结果和有趣的设计方案，计算使用了三种物理控制网格尺寸：超粗、超细和超精，并使用了不同值的特殊优化设置，如最大位移（dmax）和过滤半径（Rmin）。根据这三种方法得出的结果，我们可以得出结论：网格元素尺寸以及所研究的参数 dmax 和 Rmin 对最终的优化结果有重大影响。
{"title":"Modern software capabilities for shape optimization of shells","authors":"E. Ermakova, Marina I. Rynkovskaya","doi":"10.15625/2525-2518/18788","DOIUrl":"https://doi.org/10.15625/2525-2518/18788","url":null,"abstract":"The article is devoted to the shape optimization of shell structures in Comsol Multiphysics using three gradient-based methods: IPOPT (Interior Point OPTimizer), SNOPT (Sparse Nonlinear OPTimizer) and MMA or GCMMA (the Method of Moving Asymptotes). Two types of complex shapes, such as right helicoid and developable helicoid are taken for the computational experiment. The task is to investigate the initial design and optimization process of two helicoids. To obtain a more accurate result and an interesting design solution, the calculation is carried out using three physics-controlled mesh sizes: extra coarse, fine and extra fine with varying values of special optimization settings, such as maximum displacement (dmax) and filter radius (Rmin). The results obtained using the three methods allow to conclude that the mesh element size and studied parameters dmax and Rmin have a significant impact on the final optimization result.","PeriodicalId":23553,"journal":{"name":"Vietnam Journal of Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140437005","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}
Pub Date : 2024-02-23DOI: 10.15625/2525-2518/18627
Hakkee Jung
The changes in Subthreshold Swing (SS) were observed for changes in remanent polarization Pr and coercive field Ec, which determine the characteristics of the P-E hysteresis curve of ferroelectric in Ferrolectric FET (FeFET). A multilayer structure of Metal-Ferroelectric-Metal-Insulator-Semiconductor (MFMIS) was used for the junctionless double gate structure. To obtain the SS value, the analytical SS model was used. The ranges of 15≤Pr ≤30 μC/cm2 and 0.8≤Ec≤1.5 MV/cm, which were reasonable in various experiments and did not generate unstable regions in the relationship of drain current and gate voltage, were considered. As a result, the SS decreased as Pr decreased and Ec increased due to the capacitance change in the ferroelectric. This phenomenon is because the controllability of channel carriers by the gate voltage increases due to the increasing of change in the ferroelectric voltage for the gate voltage as Pr decreases and the memory window increases. Since the SS decreased linearly in the memory window, the SS constantly changed according to the ratio of Pr and Ec, Pr/Ec. As the ferroelectric thickness increased, the SS decreased significantly, but the change of SS with respect to the Pr/Ec was severe. In general, as the channel length decreases, SS increases. However, when the Pr/Ec decreased to 10 pF/cm, the SS tended to decrease as the channel length decreased. The reason for this can be attributed to the fact that the relative thickness of ferroelectric increases with small channel length.
在铁电场效应晶体管（FeFET）中，阈下摆动（SS）随剩极化 Pr 和矫顽力场 Ec 的变化而变化，而剩极化和矫顽力场 Ec 决定了铁电的 P-E 磁滞曲线特性。无结双栅结构采用了金属-铁电-金属-绝缘体-半导体（MFMIS）的多层结构。为了获得 SS 值，使用了 SS 分析模型。考虑了 15≤Pr ≤30 μC/cm2 和 0.8≤Ec≤1.5 MV/cm 的范围，这些范围在各种实验中都是合理的，并且在漏极电流和栅极电压的关系中不会产生不稳定区域。结果，由于铁电体中电容的变化，SS 随着 Pr 的减小和 Ec 的增大而减小。出现这种现象的原因是，随着 Pr 减小和存储器窗口增大，铁电电压对栅极电压的变化增大，沟道载流子对栅极电压的可控性也随之增大。由于 SS 在存储器窗口中呈线性下降，因此 SS 会根据 Pr 和 Ec 的比值（Pr/Ec）不断变化。随着铁电厚度的增加，SS 显著减小，但 SS 随 Pr/Ec 的变化非常剧烈。一般来说，随着沟道长度的减少，SS 会增加。然而，当 Pr/Ec 下降到 10 pF/cm 时，随着沟道长度的减少，SS 也呈下降趋势。其原因可能是铁电体的相对厚度随着通道长度的减小而增加。
{"title":"Impact of Hysteresis Curve on Subthreshold Swing in Ferroelectric FET","authors":"Hakkee Jung","doi":"10.15625/2525-2518/18627","DOIUrl":"https://doi.org/10.15625/2525-2518/18627","url":null,"abstract":"The changes in Subthreshold Swing (SS) were observed for changes in remanent polarization Pr and coercive field Ec, which determine the characteristics of the P-E hysteresis curve of ferroelectric in Ferrolectric FET (FeFET). A multilayer structure of Metal-Ferroelectric-Metal-Insulator-Semiconductor (MFMIS) was used for the junctionless double gate structure. To obtain the SS value, the analytical SS model was used. The ranges of 15≤Pr ≤30 μC/cm2 and 0.8≤Ec≤1.5 MV/cm, which were reasonable in various experiments and did not generate unstable regions in the relationship of drain current and gate voltage, were considered. As a result, the SS decreased as Pr decreased and Ec increased due to the capacitance change in the ferroelectric. This phenomenon is because the controllability of channel carriers by the gate voltage increases due to the increasing of change in the ferroelectric voltage for the gate voltage as Pr decreases and the memory window increases. Since the SS decreased linearly in the memory window, the SS constantly changed according to the ratio of Pr and Ec, Pr/Ec. As the ferroelectric thickness increased, the SS decreased significantly, but the change of SS with respect to the Pr/Ec was severe. In general, as the channel length decreases, SS increases. However, when the Pr/Ec decreased to 10 pF/cm, the SS tended to decrease as the channel length decreased. The reason for this can be attributed to the fact that the relative thickness of ferroelectric increases with small channel length.","PeriodicalId":23553,"journal":{"name":"Vietnam Journal of Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140437372","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}
Pub Date : 2024-02-23DOI: 10.15625/2525-2518/17531
Nhung Hac Thi, Thi Thu Hien Nguyen, Truong Cong Doanh, Do Thi Mai Huong, Tien Dat Doan, H. Oanh, Nguyen Duc Tuyen, Mai Ha Hoang
Bisulfate intercalated graphites with different particle sizes were prepared by a chemically oxidative method using natural flaky graphites as raw materials. The morphology and structure of the expandable graphites were confirmed by Fourier transform infrared spectroscopy, X-ray diffraction patterns, and scanning electron microscope. The effect of the particle size on the expanded volume was also investigated. Expandable graphite with +100 mesh particle size (EG100) showed the highest expanded volume of 225 mL/g. Moreover, a combination of expandable graphite, red phosphorus (RP), and melamine cyanurate (MC) into a polypropylene (PP) matrix exhibited a synergistic flame retardant effect. The composite loading EG100, RP, and MC with a mass ratio of 1:1:1 and a total filler content of 18 wt.% achieved a UL94 V-0 rating and a limiting oxygen index (LOI) of 28.9 %. The effect of particle size of expandable graphite on the mechanical properties was also evaluated.
{"title":"Preparation of expandable flake-graphites with different particle sizes and their flame-retardant application for polypropylene","authors":"Nhung Hac Thi, Thi Thu Hien Nguyen, Truong Cong Doanh, Do Thi Mai Huong, Tien Dat Doan, H. Oanh, Nguyen Duc Tuyen, Mai Ha Hoang","doi":"10.15625/2525-2518/17531","DOIUrl":"https://doi.org/10.15625/2525-2518/17531","url":null,"abstract":"Bisulfate intercalated graphites with different particle sizes were prepared by a chemically oxidative method using natural flaky graphites as raw materials. The morphology and structure of the expandable graphites were confirmed by Fourier transform infrared spectroscopy, X-ray diffraction patterns, and scanning electron microscope. The effect of the particle size on the expanded volume was also investigated. Expandable graphite with +100 mesh particle size (EG100) showed the highest expanded volume of 225 mL/g. Moreover, a combination of expandable graphite, red phosphorus (RP), and melamine cyanurate (MC) into a polypropylene (PP) matrix exhibited a synergistic flame retardant effect. The composite loading EG100, RP, and MC with a mass ratio of 1:1:1 and a total filler content of 18 wt.% achieved a UL94 V-0 rating and a limiting oxygen index (LOI) of 28.9 %. The effect of particle size of expandable graphite on the mechanical properties was also evaluated.","PeriodicalId":23553,"journal":{"name":"Vietnam Journal of Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140435911","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}
Pub Date : 2024-02-23DOI: 10.15625/2525-2518/19223
Nguyen Thanh Dam, Nguyen Canh Viet, Phùng Thị Vĩ, Nguyen Manh Huy, Ta Thi Thao, Duong Hong, Anh, J. Vasel, Pham Hung Viet
Compost stability is a significant quality indicator that needs to be determined before using compost as an organic fertiliser. In this work, a novel device for assessing compost stability based on the oxygen consumption (OC) method was successfully developed. The design of this prototype was created to effectively solve inherent limitations observed in commercially available equipment functioning on the same concept (Oxitop devices). The performance of the device was evaluated in the laboratory to determine the OC of two different types of compost samples (food waste and green compost). The data indicated that the device worked stably and accurately during the test. Between the two types of samples, the compost based on food waste had higher AT4 and OCmax values but with lower K values. According to the EU regulations, both types of samples were considered stable.
堆肥稳定性是一项重要的质量指标，在将堆肥用作有机肥料之前需要对其进行测定。在这项工作中，成功开发了一种基于耗氧量（OC）方法的新型堆肥稳定性评估设备。该原型的设计旨在有效解决基于相同概念的市售设备（Oxitop 设备）的固有局限性。在实验室中对该设备的性能进行了评估，以确定两种不同类型堆肥样本（食物垃圾和绿色堆肥）的氧气消耗量。数据显示，该设备在测试过程中工作稳定、准确。在两种样品中，厨余堆肥的 AT4 值和 OCmax 值较高，但 K 值较低。根据欧盟的相关规定，这两种样品都被认为是稳定的。
{"title":"Design, development and evaluation of novel equipment for compost stability tests","authors":"Nguyen Thanh Dam, Nguyen Canh Viet, Phùng Thị Vĩ, Nguyen Manh Huy, Ta Thi Thao, Duong Hong, Anh, J. Vasel, Pham Hung Viet","doi":"10.15625/2525-2518/19223","DOIUrl":"https://doi.org/10.15625/2525-2518/19223","url":null,"abstract":"Compost stability is a significant quality indicator that needs to be determined before using compost as an organic fertiliser. In this work, a novel device for assessing compost stability based on the oxygen consumption (OC) method was successfully developed. The design of this prototype was created to effectively solve inherent limitations observed in commercially available equipment functioning on the same concept (Oxitop devices). The performance of the device was evaluated in the laboratory to determine the OC of two different types of compost samples (food waste and green compost). The data indicated that the device worked stably and accurately during the test. Between the two types of samples, the compost based on food waste had higher AT4 and OCmax values but with lower K values. According to the EU regulations, both types of samples were considered stable.","PeriodicalId":23553,"journal":{"name":"Vietnam Journal of Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140437868","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}
Pub Date : 2024-02-23DOI: 10.15625/2525-2518/18001
Linh Ngoc Vu, Thu Phuong Nguyen, Phuong Thu Le, Thi Mai Thanh Dinh, Hong Nam Nguyen
In–depth information about the characteristics and potential use of post-gasification residues is the key to unlock the sustainability potential of biomass gasification. This study aimed to explicate the physico-chemical properties of residues after the gasification of macadamia nut shell using a commercial gasifier. The results revealed an important amount of carbon content remained in the residues, marking the low conversion efficiency of the process. The obtained residues were deemed unsuitable for use as adsorbents due to low surface areas with non-porous structures. However, the surface of the residues contained multiple carboxyl and hydroxyl functional groups. Also, a remarkable amount of K (up to 86 wt% of the char’s total inorganic elements) was observed to be evenly distributed on the char surface. The results solidified the possibility of utilizing the residues as bio-fertilizers, and provided essential data for the development of sustainable energy production processes using macadamia nut shell for gasification.
{"title":"Physico-chemical properties of macadamia nut shell post-gasification residues and potential agricultural application","authors":"Linh Ngoc Vu, Thu Phuong Nguyen, Phuong Thu Le, Thi Mai Thanh Dinh, Hong Nam Nguyen","doi":"10.15625/2525-2518/18001","DOIUrl":"https://doi.org/10.15625/2525-2518/18001","url":null,"abstract":"In–depth information about the characteristics and potential use of post-gasification residues is the key to unlock the sustainability potential of biomass gasification. This study aimed to explicate the physico-chemical properties of residues after the gasification of macadamia nut shell using a commercial gasifier. The results revealed an important amount of carbon content remained in the residues, marking the low conversion efficiency of the process. The obtained residues were deemed unsuitable for use as adsorbents due to low surface areas with non-porous structures. However, the surface of the residues contained multiple carboxyl and hydroxyl functional groups. Also, a remarkable amount of K (up to 86 wt% of the char’s total inorganic elements) was observed to be evenly distributed on the char surface. The results solidified the possibility of utilizing the residues as bio-fertilizers, and provided essential data for the development of sustainable energy production processes using macadamia nut shell for gasification.","PeriodicalId":23553,"journal":{"name":"Vietnam Journal of Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140435892","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}
Pub Date : 2024-02-23DOI: 10.15625/2525-2518/18222
Nguyễn Tấn Thuận, Tran Thi, Thuy Trinh, Doan Van Ban, Truong Ngoc, Chau, Nguyen Thi Anh, Phuong, Nguyen Truong Thang
In relational and object-oriented database systems there is always data that is naturally fuzzy or uncertain. However, to deal with complex data types with fuzzy nature, these systems have many limitations. Therefore, in order to represent and manage fuzzy data, it is necessary to have a fuzzy interrogation system to facilitate non-expert users. To solve this challenge, the paper proposes two different approaches to increase the flexibility of the fuzzy interrogation system. Firstly, based on similarity measures and fuzzy logic, we develop three fuzzy query processing algorithms for single-condition and multi-condition cases such as FQSIMSC (Fuzzy Query Sim Single Condition), FQSIMMC (Fuzzy Query Sim Multi-Condition) and FQSEM (Fuzzy Query SEM). Secondly, we combine the fuzzy clustering algorithm EMC (Expectation maximization Coefficient) and the query processing algorithm that is based on fuzzy partitions FQINTERVAL (Fuzzy Query Interval). With this approach, we not only improve query processing cost but also support applications and devices equipped with intelligent interactive function that easily interacts with the fuzzy query system. The results of our theoretical and experimental analysis, it can be seen that both the proposed methods significantly reduce the processing time and memory space for a data set (extracted from UCI) that has a fuzzy and incomplete natural element with the resulting data size being optimal
{"title":"Some new fuzzy query processing methods based on similarity measurement and fuzzy data clustering","authors":"Nguyễn Tấn Thuận, Tran Thi, Thuy Trinh, Doan Van Ban, Truong Ngoc, Chau, Nguyen Thi Anh, Phuong, Nguyen Truong Thang","doi":"10.15625/2525-2518/18222","DOIUrl":"https://doi.org/10.15625/2525-2518/18222","url":null,"abstract":"In relational and object-oriented database systems there is always data that is naturally fuzzy or uncertain. However, to deal with complex data types with fuzzy nature, these systems have many limitations. Therefore, in order to represent and manage fuzzy data, it is necessary to have a fuzzy interrogation system to facilitate non-expert users. To solve this challenge, the paper proposes two different approaches to increase the flexibility of the fuzzy interrogation system. Firstly, based on similarity measures and fuzzy logic, we develop three fuzzy query processing algorithms for single-condition and multi-condition cases such as FQSIMSC (Fuzzy Query Sim Single Condition), FQSIMMC (Fuzzy Query Sim Multi-Condition) and FQSEM (Fuzzy Query SEM). Secondly, we combine the fuzzy clustering algorithm EMC (Expectation maximization Coefficient) and the query processing algorithm that is based on fuzzy partitions FQINTERVAL (Fuzzy Query Interval). With this approach, we not only improve query processing cost but also support applications and devices equipped with intelligent interactive function that easily interacts with the fuzzy query system. The results of our theoretical and experimental analysis, it can be seen that both the proposed methods significantly reduce the processing time and memory space for a data set (extracted from UCI) that has a fuzzy and incomplete natural element with the resulting data size being optimal","PeriodicalId":23553,"journal":{"name":"Vietnam Journal of Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140437096","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}
Pub Date : 2024-02-22DOI: 10.15625/2525-2518/17929
Hoang Lam, Nguyen Van Trang, Dinh Thi Duyen, Le Thi Hong Lien, Pham Thy San, Bui Thi, Van Anh
Corrosion under insulation (CUI) is very common and severely occurs in chemical/oil and gas industries, however, it is difficult to detect this corrosion by non-destructive testing (NDT) techniques. Carbon steel resistant sensors were used to determine CUI in this research. The output voltage values of the sensor were measured over time and from which the corrosion loss in sensor’s thickness was calculated. Carbon steel samples were exposed to the sensors under the same conditions for the same periods, and the corrosion loss of the samples was determined by weight loss. The results show that when the sensors were corroded within 10-20 % the corrosion loss of carbon steel samples is equivalent to that calculated from the output data of the sensors with a standard deviation of 6-24 %. These results demonstrate the high potential of resistance sensors in determining CUI and predicting damage of industrial components and pipes.
绝缘层下腐蚀（CUI）在化工/石油和天然气行业中非常普遍和严重，但很难通过无损检测（NDT）技术检测出这种腐蚀。本研究使用耐碳钢传感器来确定 CUI。测量传感器随时间变化的输出电压值，并据此计算传感器厚度的腐蚀损失。碳钢样品在相同条件下暴露在传感器上的时间相同，样品的腐蚀损失根据重量损失确定。结果表明，当传感器受到 10-20% 的腐蚀时，碳钢样品的腐蚀损失与根据传感器输出数据计算得出的结果相当，标准偏差为 6-24%。这些结果表明，电阻传感器在确定 CUI 和预测工业部件和管道损坏方面具有很大的潜力。
{"title":"Research on using resistant sensor to predict corrosion under insulation of carbon steel","authors":"Hoang Lam, Nguyen Van Trang, Dinh Thi Duyen, Le Thi Hong Lien, Pham Thy San, Bui Thi, Van Anh","doi":"10.15625/2525-2518/17929","DOIUrl":"https://doi.org/10.15625/2525-2518/17929","url":null,"abstract":"Corrosion under insulation (CUI) is very common and severely occurs in chemical/oil and gas industries, however, it is difficult to detect this corrosion by non-destructive testing (NDT) techniques. Carbon steel resistant sensors were used to determine CUI in this research. The output voltage values of the sensor were measured over time and from which the corrosion loss in sensor’s thickness was calculated. Carbon steel samples were exposed to the sensors under the same conditions for the same periods, and the corrosion loss of the samples was determined by weight loss. The results show that when the sensors were corroded within 10-20 % the corrosion loss of carbon steel samples is equivalent to that calculated from the output data of the sensors with a standard deviation of 6-24 %. These results demonstrate the high potential of resistance sensors in determining CUI and predicting damage of industrial components and pipes.","PeriodicalId":23553,"journal":{"name":"Vietnam Journal of Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140440339","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}
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