VNUHCM Journal of Science and Technology Development <p><span id="result_box" class="" lang="en"><span title="Tạp chí Phát triển Khoa học và Công nghệ (PTKH&amp;CN) của Đại học Quốc gia thành phố Hồ Chí Minh (ĐHQG-HCM) được thành lập từ năm 1997, ra số đầu tiên vào tháng 1 năm 1998. Từ năm 2006 Tạp chí đã"><strong>Science and Technology Development Journal</strong> (STDJ), Vietnam National University - Ho Chi Minh City (VNU-HCM) was established in 1997. And the first issue was published in January 1998 with </span><span title="đăng ký mã số chuẩn quốc tế ISSN 1859-0128.">ISSN 1859-0128. </span><span title="Từ đó cho đến nay, Tạp chí PTKH&amp;CN đã trở thành diễn đàn khoa học quan trọng nhất của đội ngũ cán bộ nghiên cứu, giảng viên, nghiên cứu sinh của ĐHQG-HCM và cũng là diễn đàn khoa học công nghệ đáng tin cậy của">Since then, STDJ has become the most important scientific forum of scientists from VNU-HCM as well as</span><span title="nhiều nhà nghiên cứu, giảng viên các trường đại học khác tại Việt Nam."> other universities. </span><span title="Tạp chí đã trải qua 20 năm phát triển và đã trở thành nhịp cầu giao lưu khoa học, cũng như làm phong phú tài liệu tham khảo cho đội ngũ giảng viên, nghiên cứu sinh, sinh viên ĐHQG-HCM nói riêng và các Trường đại">The magazine has undergone 20 years of development and has become a bridge for scientific exchanges, as well as enriching reference materials for the faculty, doctoral students, students of VNU-HCM in particular and other universities, institutes... </span></span></p> <p><span id="result_box" class="" lang="en"><span title="học phía Nam nói chung. "><br></span><span title="Tính đến hết năm 2016 Tạp chí đã xuất bản được 276 số với 2714 bài nghiên cứu của các nhà khoa học, cán bộ trong và ngoài ĐHQG-HCM trong 5 lĩnh vực nghiên cứu: Kỹ thuật và Công nghệ, Khoa học Tự nhiên,">By the end of 2016, the journal has published 276 issues with 2714 research articles in five areas of research: Engineering and Technology, Natural Sciences, </span><span title="Khoa học Xã hội và Nhân văn, Kinh tế luật và Khoa học Quản lý, Khoa học Trái đất và Môi trường tương ứng với 5 chuyên san chuyên ngành của Tạp chí.">Social Sciences and Humanities, Economics of Law and Management Sciences, Earth Sciences and Environment corresponding to 5 specialized journals of the Journal. </span></span></p> <p><span id="result_box" class="" lang="en"><span title="Tạp chí đã được phát hành tại các thư viện của các đơn vị thành viên của ĐHQG-HCM, các Sở Khoa học Công nghệ của các tỉnh thành trên cả nước và được Hội đồng học hàm Giáo sư Nhà nước đánh giá cao.">The magazine has been widely indexed in the various libraries at Vietnam. </span></span></p> <p><span id="result_box" class="" lang="en"><span title="Từ tháng 12/2006 Tạp chí đã nhận được sự giúp đỡ của tổ chức mạng quốc tế về các xuất bản phẩm khoa học thuộc Hội đồng khoa học quốc tế để tham gia vào mạng lưới các Tạp chí Khoa học quốc tế. "><br></span><span title="Hiện nay tạp chí bao gồm 5 chuyên san sau đây: ">The journal currently consists of the following five sections:<br></span><span title="• Kỹ thuật và Công nghệ, ">• Engineering and Technology</span></span></p> <p><span id="result_box" class="" lang="en"><span title="• Khoa học Tự nhiên, ">• Natural Sciences</span></span></p> <p><span id="result_box" class="" lang="en"><span title="• Khoa học Xã hội và Nhân văn, ">• Social Sciences and Humanities</span></span></p> <p><span id="result_box" class="" lang="en"><span title="• Kinh tế luật và Khoa học Quản lý, ">• Economics, Law and Management</span></span></p> <p><span id="result_box" class="" lang="en"><span title="• Khoa học Trái đất và Môi trường">• Sciences of Earth and Environment</span></span></p> <p><span class="" lang="en"><span title="• Khoa học Trái đất và Môi trường"><span id="result_box" class="" lang="en">• Health Sciences : It includes work from basic science, clinical science, dental, nursing and other related medical fields. <br></span></span></span></p> Viet Nam National University Ho Chi Minh City en-US VNUHCM Journal of Science and Technology Development 1859-0128 <p>Copyright The Author(s) 2018. This article is published with open access by Vietnam National University, Ho Chi Minh city, Vietnam. This article is distributed under the terms of the&nbsp;<a href="" target="_blank" rel="noopener">Creative Commons Attribution License (CC-BY 4.0)</a> which permits any use, distribution, and reproduction in any medium, provided the original author(s) and the source are credited.&nbsp;</p> Effect of Applied Voltage on the Electrochemical Copolymerization of Thiophene and Dithenopyrrole Derivatives <p>The linear sweep voltammetry potentiostatic approach was employed to electrochemically synthesize the conjugated copolymers P(3HT-random-HPDTP) at three distinct applied voltages (1.4, 1.435, 1.6 V). In relation to their synthesis conditions, their chemical structural, optical, and electrical properties were investigated and compared using Fourier transform infrared (FTIR) spectroscopy, UV‒Vis absorption spectroscopy, and cyclic voltammetry (CV). The results indicated that choosing a suitable applied voltage in the electropolymerization process significantly improved the electrochemical stability and lowered the HOMO level of the conjugated copolymer.</p> Cam H. T. Nguyen Thao Phuong Le Nguyen Thao Thanh Bui Bao Kim Doan Tam Hoang Luu Chau Duc Tran Thuy Thu Truong Tung Viet Tuan Tran Hai Le Tran Xuan Van Mai Nguyen Tran Ha ##submission.copyrightStatement## 2023-05-27 2023-05-27 26 2 press press 10.32508/stdj.v26i2.4063 title description none g Improving Vietnamese Fake News Detection based on Contextual Language Model and Handcrafted Features <p><strong>Introduction</strong>: In recent years, the rise of social networks in Vietnam has resulted in an abundance of information. However, it has also made it easier for people to spread fake news, which has done a great disservice to society. It is therefore crucial to verify the reliability of news. This paper presents a hybrid approach that uses a pretrained language model called vELECTRA along with handcrafted features to identify reliable information on Vietnamese social network sites.</p> <p><strong>Methods</strong>: The present study employed two primary approaches, namely: 1) fine-tuning the model by utilizing solely textual data, and 2) combining additional meta-data with the text to create an input representation for the model.</p> <p><strong>Results</strong>: Our approach performs slightly better than other refined BERT methods and achieves state-of-the-art results on the ReINTEL dataset published by VLSP in 2020. Our method achieved a 0.9575 AUC score, and we used transfer learning and deep learning approaches to detect fake news in the Vietnamese language using meta features.</p> <p><strong>Conclusion</strong>: With regards to the results and analysis, it can be inferred that the number of reactions a post receives, and the timing of the event described in the post are indicative of the news' credibility. Furthermore, it was discovered that BERT can encode numerical values that have been converted into text.</p> Khoa Dang Pham Dang Van Thin Ngan Luu-Thuy Nguyen ##submission.copyrightStatement## 2023-05-20 2023-05-20 26 2 press press 10.32508/stdj.v26i1.3927 title description none g Synthesis of a unique oligomer by means of the thiol-maleimide reaction of extending 1,1'-(methylenedi-4,1-phenylene) bismaleimide chains for the employment of self-healing polymers <p><strong>Introduction</strong>: The Diels-Alder reaction of maleimide and furan groups is being exploited in self-healing materials; hence, it is no wonder that with the ownership of the former, 1,1'-(methylenedi-4,1-phenylene) bismaleimide (BMI) counts as a potential candidate in this area. However, it displays certain discernible demerits arising from its inflexible structure. Furthermore, the maleimide group, in all likelihood, easily takes part in the Michael addition reaction with thiol groups under basic conditions. It is crucial that this element opens the door for this ingredient to be amended with a view to weathering its shortcomings. The goal of this research is to modify the structure of BMI to create a new oligomer with maleimides at the end of its chains. <strong>Method</strong>: The oligomer was synthesized by means of the reaction of the maleimides of BMI and the thiol groups of 2,2’-(ethylenedioxy) diethanethiol (dithiol) with the support of triethylamine (TEA). In addition, an investigation into the possibility of this reaction happening without the base catalyst was carried out. The application of a wide assortment of modern measurements ranging from 1H-NMR and FT-IR to GPC provided some useful data about the molecular weight and whether the reaction occurred. <strong>Result</strong>: According to the information, the formation of the oligomer owning the maleimide and thiol terminal functions was observed with the help of TEA over the 24-hour timescale at room temperature, whereas that with a lack of this catalyst is impossible. <strong>Conclusion</strong>: The research will make a major contribution to the creation of new healable polymers reliant on the Diels-Alder mechanism in the foreseeable future.</p> Nguyen Khai Hoang Nguyen Mai Ly Nguyen Thi Duc Anh Nguyen Song Huan Hoang Dang Thuy Thu Truong Le Thu Thi Nguyen ##submission.copyrightStatement## 2023-05-28 2023-05-28 26 2 press press 10.32508/stdj.v26i2.4049 title description none g Enhancement of the crystalline phase in poly(vinylidene fluoride) by using the electrospinning technique and graphene oxide composition <p><strong>Introduction</strong>: Poly(vinylidene fluoride) (PVDF) possesses some unique characteristics, such as piezoelectric, ferroelectric, and pyroelectric properties. The β crystalline phase of PVDF exhibits the strongest piezoelectric and pyroelectric properties. In this study, the influence of the electrospinning process and graphene oxide (GO) composition on the β-phase formation of PVDF fibers is reported. <strong>Methods</strong>: The morphology of electrospun PVDF and PVDF/GO fibers was observed using a scanning electron microscope (SEM). Characteristics of the crystal phase of electrospun PVDF and PVDF/GO fibers were analyzed by Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray diffraction (XRD), and differential scanning calorimetry (DSC). <strong>Results</strong>: The PVDF fiber fabricated by the electrospinning technique had a crystallinity degree that increased by more than 117% compared to that of the precursor PVDF powder. The X-ray diffraction results show that the entire α phase of PVDF was converted to the β phase due to elongation deformation under the force of an electrical field during the electrospinning process. The presence of GO also induced the formation of the β phase of PVDF due to the interaction between the atomic groups on the surface of GO sheets and on the PVDF molecular chains. <strong>Conclusion</strong>: Both the electrospinning process and GO led to an increase in the crystallinity of PVDF. PVDF/GO nanofibers with crystallinity degrees above 60% can be applied in many fields, such as water purification membranes, air filters, energy harvesting materials, biosensors, and catalysts.</p> Thuy Thi Thu Nguyen Phan Ngoc Vu Hai Thi Trinh ##submission.copyrightStatement## 2023-05-27 2023-05-27 26 2 press press 10.32508/stdj.v26i2.4048 title description none g Molecular dynamics simulation of pressure effect on silicene nanoribbons <p><strong>Introduction</strong>: In 2D materials, the boundary of silicene formed as nanoribbons plays an essential role in synthesis and can be controlled to achieve different characteristics. Our study aims to investigate the structural preference depending on the pressure tolerance and boundary dependency. <strong>Methods</strong>: The main methodology used in our study is molecular dynamics simulation with Stillinger Weber potentials. Our simulation was carried out on 2D models of honeycomb silicene obtained through high and low pressurized cooling from the liquid state and then heat annealing for a decent time. The final configuration of silicene will be investigated in terms of structures and thermodynamic properties. <strong>Results</strong>: We found that the effect of the cooling process under high pressure formed a 4-fold ring structure, while at low pressure, 2D honeycomb networks were recovered but with different degrees of defects depending on the boundary condition. The main difference between several transitions of 2D silicene is discussed via the evolution of total energy and the change in coordination number and bond-ring distribution. <strong>Conclusions</strong>: This study provides insights into the dependency of the structure of silicene on the pressure and boundary, represented by the first-order transition at low pressure and a congregation of disordered low-numbered rings into the ordered tetragonal formation at high pressure. Notably, our results have shown that silicene nanoribbon materials can be controlled by pressure to obtain unfamiliar structures such as pentagonal and tetragonal networks.</p> Huy Anh Huynh Tuan Quoc Truong Hoang Duy Vo Le Lam Hoang Nguyen Phuong Anh Thi Ngo Ngoc Gia Thi Trinh Long Truong Nguyen ##submission.copyrightStatement## 2023-05-05 2023-05-05 26 2 2705 2713 10.32508/stdj.v26i1.4013 title description none g Viet Nam With Developing A Service Oriented Public Administration To Meet The Requirements Of New Generations Of Free Trade Agreements <p>Free trade agreements not only offer many opportunities but also pose numerous challenges for Vietnamese businesses. Continuing to operate the current governing administrative system will not promote the initiativeness, positivity and creativity of businesses. In contrast, businesses will fail to attract foreign investors due to concerns about Vietnamese regulatory agencies interfering, imposing on production and business activities, and extremely protecting the interests of domestic enterprises. It is necessary to build a service-oriented administration, taking the satisfaction of businesses and people as the goal, promoting the ownership and capacity of businesses and people, and ensuring a healthy and equal investment and business environment in the context that Vietnam increasingly participates in the common playing fields created by new-generation free trade agreements.</p> Hoàng Thị Lan Phương ##submission.copyrightStatement## 2023-05-27 2023-05-27 26 2 press press 10.32508/stdj.v26i2.4026 title description none g