Vietnam Academy Of Science Research Articles

Preface

The 48th Vietnam Conference on Theoretical Physics (VCTP-48) was held during 31 July - 3 August 2023 in Da Nang city, Viet Nam.The VCTP-48 was organized by the Institute of Physics, Vietnam Academy of Science and Technology (VAST) under the auspices of the Vietnamese Theoretical Physics Society (VTPS).The VCTP, formerly known as NCTP, has been an annual activity of VTPS since 1976. The VCTP is aimed to be an international conference for physicists in Vietnam, in the region and worldwide. Our mission is to foster scientific exchanges and to promote a high-standard level of research and education in Vietnam and in South East Asia.The conference covered a wide range of theoretical physics topics from 4 major fields:• Particle, nuclear and astrophysics,• Molecular physics, quantum optics and quantum computation,• Condensed matter physics,• Soft matter, biological and interdisciplinary physics.The conference was divided into 1 opening session, 9 oral sessions and 2 poster sessions. The duration of an invited talk is 40 minutes including time for discussion. The duration of an oral talk is 20 minutes including time for discussion.93 participants participated in the conference. 10 invited talks, 17 oral and 67 poster contributions were presented. The conference program and the abstract book can be found on the conference website: http://iop.vast.vn/vctp/48/.This volume contains 6 selected papers contributed by the participants.We gratefully acknowledge the financial support of the Unesco’s Category 2 International Centre of Physics (ICP) located at the Institute of Physics, VAST.Editors of the VCTP-48 ProceedingsTrinh Xuan Hoang, Tran Minh Tien, Hoang Anh Tuan, Vu Ngoc Tuoc, and Nguyen Huy VietList of Organizer, Sponsor, Chair, Organizing Committee, Program Committee, Secretariat and Participants are available in this pdf.

Peer Review Statement

All papers published in this volume have been reviewed through processes administered by the Editors. Reviews were conducted by expert referees to the professional and scientific standards expected of a proceedings journal published by IOP Publishing.• Type of peer review: Single Anonymous• Conference submission management system: Morressier• Number of submissions received: 6• Number of submissions sent for review: 6• Number of submissions accepted: 6• Acceptance Rate (Submissions Accepted / Submissions Received × 100): 100• Average number of reviews per paper: 1• Total number of reviewers involved: 6• Contact person for queries: Name: Trinh Xuan Hoang Email: txhoang@iop.vast.vn Affiliation: Institute of Physics, Vietnam Academy of Science and Technology

Preface

The 47th Vietnam Conference on Theoretical Physics (VCTP-47) was held during 1-4 August 2022 in Tuy Hoa city, Phu Yen province, Viet Nam.The VCTP-47 was organized by the Institute of Physics, Vietnam Academy of Science and Technology (VAST) under the auspices of the Vietnamese Theoretical Physics Society (VTPS).The VCTP, formerly known as NCTP, has been an annual activity of VTPS since 1976. The VCTP is aimed to be an international conference for physicists in Vietnam, in the region and worldwide. Our mission is to foster scientific exchanges and to promote a high-standard level of research and education in Vietnam and in South East Asia.The conference covered a wide range of theoretical physics topics from 4 major fields:• Particle, nuclear and astro-physics,• Molecular physics, quantum optics and quantum computation,• Condensed matter physics,• Soft matter, biological and interdisciplinary physics.The conference was divided into 1 opening session, 9 oral sessions and 2 poster sessions. The duration of an invited talk is 30-40 minutes including time for discussion. The duration of an oral talk is 20 minutes including time for discussion.The meeting was held onsite but all the sessions were broadcasted online on the Google Meet platform. There was only one fully online session with three invited speakers presenting their talks from abroad. For online viewing, the PDF files of the posters had be uploaded on to the conference website before the poster sessions.136 participants participated in the conference. 11 invited talks, 17 oral and 55 poster contributions were presented. The conference program and the abstract book can be found on the conference website: http://iop.vast.vn/vctp/47/.This volume contains selected papers contributed by the participants.We gratefully acknowledge the financial support of the Unesco’s Category 2 International Centre of Physics (ICP) located at the Institute of Physics, VAST.Editors of the VCTP-47 ProceedingsTrinh Xuan Hoang, Tran Minh Tien, Hoang Anh Tuan, and Vu Ngoc TuocList of Organizer, Sponsor, Chair, Organizing Committee, Program Committee, Secretariat, Participants are available in this Pdf.

Peer Review Statement

All papers published in this volume have been reviewed through processes administered by the Editors. Reviews were conducted by expert referees to the professional and scientific standards expected of a proceedings journal published by IOP Publishing.• Type of peer review: Single Anonymous• Conference submission management system: Morressier• Number of submissions received: 11• Number of submissions sent for review: 10• Number of submissions accepted: 6• Acceptance Rate (Submissions Accepted / Submissions Received × 100): 54.5• Average number of reviews per paper: 1• Total number of reviewers involved: 10• Contact person for queries: Name: Hoang Anh Tuan Email: hatuan@iop.vast.vn Affiliation: Institute of Physics, Vietnam Academy of Science and Technology

Orientation of solid-state physics and materials science at SPMS2023

The SPMS2023 conference, which focused on Solid State Physics and Materials Science, took place at Ho Chi Minh City University of Technology and Education in Ho Chi Minh City, Vietnam, from November 5 to 7, 2023. The event received a substantial turnout, with more than 397 abstracts submitted by prominent experts and emerging researchers in the field. These submissions covered the latest advancements in fundamental aspects across four specialized sessions: (A) physics and magnetic materials, (B) semiconductor and dielectric physics, (C) semiconductor and dielectric materials and devices, and (D) biomedical materials, along with materials for agriculture, energy, and the environment. The conference featured a diverse program that included 36 invited presentations, 52 contributed oral reports, and 198 scientific posters, all of which were organized into the four principal themes above. Additionally, the Organizing Committee oversaw a rigorous review process for 180 full-text reports, which were subsequently submitted to the Journal of Science and Technology (Vietnam Academy of Science and Technology).

Negative effects of fish cages on coral reefs through nutrient enrichment and eutrophication in Nha Trang Bay, Viet Nam

The potential impact of cage farming activities on nutrient enrichment of the coastal waters of Nha Trang bay, Viet Nam as investigated within a project financed by the Vietnam Academy of Science and Technology (VAST). Results show a very high level of nitrogen (N) in the studied area: the average content of dissolved inorganic nitrogen (DIN) was 177.4 ±6.0μg/l (range from 169.9 to 188.9μg/l), in which NO3-N accounts for the major proportion (average 152.9 ±1.9μg/l). The Redfield ratio (N/P) also showed values larger than 16 in almost all studied sites, indicating that phosphorus may be the limiting nutritional factor in these coastal waters. The TRIX indexes recorded for both the surface and bottom waters are within a range of about 5–6 (at high nutrient level); especially at sites under the cages and near the cage farming area. Cross-transplantation experiments with corals showed significant differences at different sites, particularly in relation to distance to fish cages. In comparison, the zooxanthellae densities of Acopora formosa in coral polyps indicated a rapidly reduced value after 31 days of exposure in the polluted areas. Strong side effects such as increased sedimentation as a result of fish farm activities can be detected on nearby coral reef. It is concluded that fish cage farming is negatively impacting coral reefs by being a point source of surplus nutrients.

The Current Situation and Solutions to Improve the Management of Science and Technology Activities at Public Non-business Units under Vietnam Academy of Science and Technology

Lately, many important documents on strategic orientation, systemizes and policies for science and technology development have been issued. The management of science and technology activities has been constantly changing and adapting; shown by more favorable legal environment; ensuring the rights and interests of organizations and individuals involved in science and technology activities; ensuring the decentralization, level of responsibilities among each participants in the implementation of science and technology activities. Due to the change in policy and practical development needs, the management of science and technology tasks at public non-business units under the Vietnam Academy of Science and Technology has made changes in accordance with the Law on Science and Technology in 2013 and Decree No. 60/2021/ND-CP dated June 21, 2021 of the Government stipulating the mechanism of financial autonomy for public non-business units. By understanding of the current situation and affecting factors of the management of science and technology activities at public non-business units, solutions are proposed to complete the management of such activities in accordance with the functions and tasks of public non-business units under the Vietnam Academy of Science and Technology will contribute to the improvement of the management of science and technology tasks of the country in general, and of the Vietnam Academy of Science and Technology in particular.

Preface

The 46th Vietnam Conference on Theoretical Physics (VCTP-46) was held during 4-6 October 2021 in Ha Noi, Viet Nam.The VCTP-46 was organized by the Institute of Physics, Vietnam Academy of Science and Technology (VAST) under the auspices of the Vietnamese Theoretical Physics Society (VTPS).The VCTP, formerly known as NCTP, has been an annual activity of VTPS for 46 years since 1976. The VCTP is aimed to be an international conference for physicists in Vietnam, in the region and worldwide. Our mission is to foster scientific exchanges and to promote a high-standard level of research and education in Vietnam and in South East Asia.Organizer, Sponsor, Honorary Chair, Chair, Organizing Committee, Program Committee, Secretariat, List of Participants are available in the pdf

Peer Review Statement

All papers published in this volume have been reviewed through processes administered by the Editors. Reviews were conducted by expert referees to the professional and scientific standards expected of a proceedings journal published by IOP Publishing.• Type of peer review: Single Anonymous• Conference submission management system: Morressier• Number of submissions received: 18• Number of submissions sent for review: 17• Number of submissions accepted: 12• Acceptance Rate (Submissions Accepted / Submissions Received × 100): 66.7• Average number of reviews per paper: 1.25• Total number of reviewers involved: 18• Contact person for queries: Name: Trinh Xuan Hoang Email: txhoang@iop.vast.vn Affiliation: Institute of Physics, Vietnam Academy of Science and Technology

Effect of tide to storm surge in Do Son coastal zone, Hai Phong

The magnitude of storm surge depends on many factors: The intensity, direction, and speed of the storm, coastal topography, tidal height, etc. This paper presents the study results of the influence of tide on storm surge in Do Son coatal zone, Hai Phong City, based on the calculating results of storm surge in cases tidal and non-tidal storms landed into this coastal area from 1951 to 2020. The numerical model is used to calculate storm surge in this study is the TSIM11 model. This model can calculate wave, tide and storm surge and it was constructed by the Institute of Mechanics, Vietnam Academy of Science and Technology. The numerical model has been calibrated and validated using measurement data from stations in the study area.

X-ray fluorescence equipment and method, nutrient content analysis in solid NPK compound fertilizer

The paper presented two X-ray fluorescence analysis methods applicable to element content analysis in mixed fertilizers. The applied addition method determined the content of each ingredient in the fertilizer. The fundamental parameter method was applied for quick analysis, and at the same time, the content of ingredients on the fertilizer production line. X-ray fluorescence analysis methods and equipment have been researched and developed by the Institute of Materials Science - Vietnam Academy of Science and Technology and put into the gold and silver field for more than 30 years. The machines fabricated after 2014 applied TCVN 7055:2014, the 2nd edition "gold and gold alloys – Determination of gold content by X-ray fluorescence method". The national gold standard sample set, managed by the Vietnam Metrology Institute, was used to calibrate the machine, which has standard association with NIST (USA) and Krastsvetmet (Russia). Up to now, there are nearly 100 machines operating in more than twenty provinces and cities across the country, used to check the content of alloying components in gold jewelry processing, production and trading. The aim of new research and development in the field of fertilizers, in the coming time, is to transfer equipment and analysis methods to fertilizer production and trading enterprises.

Contributions to the biodiversity of Vietnam - Results of VIETBIO inventory work and field training in Cuc Phuong National Park.

VIETBIO [Innovative approaches to biodiversity discovery and characterisation in Vietnam] is a bilateral German-Vietnamese research and capacity building project focusing on the development and transfer of new methods and technology towards an integrated biodiversity discovery and monitoring system for Vietnam. Dedicated field training and testing of innovative methodologies were undertaken in Cuc Phuong National Park as part and with support of the project, which led to the new biodiversity data and records made available in this article collection.VIETBIO is a collaboration between the Museum für Naturkunde Berlin – Leibniz Institute for Evolution and Biodiversity Science (MfN), the Botanic Garden and Botanical Museum, Freie Universität Berlin (BGBM) and the Vietnam National Museum of Nature (VNMN), the Institute of Ecology and Biological Resources (IEBR), the Southern Institute of Ecology (SIE), as well as the Institute of Tropical Biology (ITB); all Vietnamese institutions belong to the Vietnam Academy of Science and Technology (VAST).The article collection "VIETBIO" (https://doi.org/10.3897/bdj.coll.63) reports original results of recent biodiversity recording and survey work undertaken in Cuc Phuong National Park, northern Vietnam, under the framework of the VIETBIO project. The collection consist of this “main” cover paper – characterising the study area, the general project approaches and activities, while also giving an extensive overview on previous studies from this area – followed by individual papers for higher taxa as studied during the project. The main purpose is to make primary biodiversity records openly available, including several new and interesting findings for this biodiversity-rich conservation area. All individual data papers with their respective primary records are expected to provide useful baselines for further taxonomic, phylogenetic, ecological and conservation-related studies on the respective taxa and, thus, will be maintained as separate datasets, including separate GUIDs also for further updating.

Enthusiastic discussions on solid-state physics and materials science at SPMS2021

The 12th National Conference on Solid State Physics and Materials Science (SPMS2021) gathered various notable scientists (7 plenary speakers and 34 invited speakers). Attending the conference and actively participating in the debate were more than 450 scholars with an interest in the topic. Four hundred reports were divided into five specialized sessions, including (A) physics and magnetic materials, (B) semiconductor and dielectric physics, (C) semiconductor and dielectric materials and devices, (D) biomedical materials and materials for agriculture, energy, and the environment, and (E) composite materials - metals, ceramics, and Vietnam-Korea sessions on applied physics. In addition, the Organizing Committee received numerous full-text reports that had been submitted to the Journal of Science and Technology (Vietnam Academy of Science and Technology) following a rigorous review procedure. SPMS2021 co-organized by the Vietnam Physical Society, the Vietnam Materials Research Society (V-MRS), the Institute of Physics, the Institute of Materials Science (Vietnam Academy of Science and Technology), Hanoi University of Science and Technology, Vietnam National University (VNU), Phenikaa University, and Can Tho University was held on 13 – 15 August 2022 in Can Tho City after nearly 9 months of postponement due to the COVID-19 pandemic. The conference has attracted 7 plenary speakers, 34 invited speakers, and over 450 scientists (Figure 1, Table 1, and Table 2) 1. It is not only a sizable and esteemed scientific conference that draws the interest of the Vietnamese scientific community, but it is also a venue for getting together, exchanging ideas, and disseminating the most recent advancements in the SPMS sector. Since 1995, it has been conducted continuously every two years. Many scientists are generally interested in the domains of solid-state physics and materials science, which have a wide range of activities and exceptional accomplishments in both basics and applications in Vietnam.

Design of real-time cow behavior monitoring system based on wireless sensor networks and K-Mmeans clustering algorithm

Introduction: The present article is the product of the research whose code CS20.04, carried out during 2020. This work was supported by the Institute of Information Technology (IOIT), Vietnam Academy of Science and Technology (VAST).
 Problem: Animal monitoring is a significant problem in the agricultural sector. The primary purpose is to monitor the health of animals regularly. Consequently, animal welfare and product quality could be improved, leading to an improvement in profit. Cow behavior recognition system was considered as the right solution for cow monitoring. The requirements for this kind of system are economical, high performance, and real-time.
 Objective: The research objective is to design a real-time cow monitoring system based on wireless sensor networks and the K-means clustering algorithm.
 Methodology: A wireless sensor node was designed to measure the collar-mounted acceleration data using an accelerometer. Firstly, the collected data were classified into three classes based on the VeDBA (Vector of Dynamic Body Acceleration) feature using the K-means algorithm. Then, the thresholds for VeDBA in the previous step were used to classify new data.
 Results: Three behaviors (including feeding, lying, and standing) were classified in real-time with the accuracy of classification about 89%.
 
 Conclusion: The proposed system could be adapted in monitoring cow in real-time, the behavior classification could be implemented on the microcontroller. The results confirmed the reliability of the proposed system.
 Originality: The behavior classification could be implemented on the microcontroller for the first time in monitoring cow.
 Limitations: Only three behaviors were classified in the experiment.

Preface

The 45th Vietnam Conference on Theoretical Physics (VCTP-45) was held during 12-14 October 2020 in Vinh Yen city, Vinh Phuc province, Viet Nam.The VCTP-45 was organized by the Institute of Physics, Vietnam Academy of Science and Technology (VAST) under the auspices of the Vietnamese Theoretical Physics Society (VTPS).The VCTP, formerly known as NCTP, has been an annual activity of VTPS for 45 years. The VCTP is aimed to be an international conference for physicists in Vietnam, in the region and worldwide. Our mission is to foster scientific exchanges and to promote a high-standard level of research and education in Vietnam and in South East Asia.The conference covered a wide range of theoretical physics topics from 4 major fields:•Particle, nuclear and astro-physics,•Molecular physics, quantum optics and quantum computation,•Condensed matter physics,•Soft matter, biological and interdisciplinary physics.The conference was divided into one opening session, 10 oral sessions and 2 poster sessions separated by coffee and lunch breaks. The duration of an invited talk is 30 minutes including time for discussion. The duration of an oral talk is 20 minutes including time for discussion.Due to the Covid-19 pandemic, the conference was organized in a hybrid mode with both offline and online participation methods. The offline participation took place at the conference site, whereas the online participation was given over video conferencing. The Zoom and Microsoft Meeting softwares were used for the online participation and for broadcasting the offline sessions online. Poster presenters were requested to upload their posters on the conference website prior to the conference sessions. In general, both participation methods worked well except some limitations of the online method, such as for taking part in discussions. Due to international travel bans/restrictions, we did not have participants coming from abroad. There were, however, 3 participants who are from Japan and Philippines but working in Vietnam.150 participants participated in the conference including 98 offline and 52 online participants. 8 invited talks, 25 oral and 98 poster contributions were presented.This volume contains selected papers contributed by the participants.Editors of the VCTP-45 ProceedingsTrinh Xuan Hoang, Institute of Physics, VAST, hoang@iop.vast.ac.vn Hoang Anh Tuan, Institute of Physics, VAST, hatuan@iop.vast.ac.vn Vu Ngoc Tuoc, Hanoi University of Science and Technology, tuoc.vungoc@hust.edu.vn https://iop.vast.ac.vn/theor/conferences/nctp/45Organizer, logo, photos, List of Participants, Online participants, are available in the pdf

Peer review declaration

All papers published in this volume of Journal of Physics: Conference Series have been peer reviewed through processes administered by the Editors. Reviews were conducted by expert referees to the professional and scientific standards expected of a proceedings journal published by IOP Publishing.• Type of peer review: Single-blind • Conference submission management system: Authors submit papers through the conference website. Editors contact authors and referees via email. • Number of submissions received: 21 • Number of submissions sent for review: 20 • Number of submissions accepted: 16 • Acceptance Rate (Number of Submissions Accepted / Number of Submissions Received X 100): 76% • Average number of reviews per paper: 1 • Total number of reviewers involved: 18 • Any additional info on review process: • Contact person for queries (please include: name, affiliation, institutional email address) Trinh Xuan Hoang, Institute of Physics, Vietnam Academy of Science and Technology, hoang@iop.vast.vn

A Methodology to Calculate the Supply and Demand Balance by Region for Vietnam's Energy Systems

The energy supply and demand balance is one of the important issues to address when proposing options for energy system development. Currently, several tools are utilized for calculating the supply and demand balance for Vietnam's energy systems. These tools are instrumental in developing the national energy system. However, most of them treat the national energy system as a unified whole, with no specific focus on regional energy supply and demand balances. This paper presents a methodology to calculate the supply and demand balance for Vietnam's energy systems by region, with the practical application of Corrective Module1, a piece of software which is a result of the joint research and development effort by the Institute of Energy Science, Vietnam Academy of Science and Technology (VAST) and the Melentiev Energy Systems Institute, Siberian Branch of the Russian Academy of Sciences (RAS). The findings of this study demonstrate that the energy system supply and demand balance calculated by region is the scientific basis for researchers, managers, and policymakers to get a clear vision of possible energy system development at the national and regional scale and to provide directions and policies that are consistent with the conditions of each region and the country. This approach is appropriate for Vietnam's geographical conditions, infrastructure, energy resources, load distribution, and policy framework.

Enhanced removal of nutrients and heavy metals from domestic-industrial wastewater in an academic campus of Hanoi using modified hybrid constructed wetlands.

Vietnam, like many developing countries, is facing serious water quality issues due to discharging wastewaters without treatment or with improper treatment, which can constitute a potential risk for aquatic ecosystems, food safety and human health. Hybrid constructed wetlands with four substrate layers (HCW) and modified hybrid constructed wetland (MHCW-1 and MHCW-2) with seven substrate layers were designed to evaluate the enhanced treatment capacity for wastewaters. To this end, we carried out an outdoor experiment at the Vietnam Academy of Science and Technology, Vietnam to treat its wastewaters from April to August 2019. All constructed wetland units were planted with reed Phragmites australis and cyperus Cyperus alternifolius; and specifically wetland MHCW-2 was cultured with earthworm Perionys excavates. Results indicated that MHCW-1 and MHCW-2 with seven substrate layers had higher removal efficiencies of NO3 --N, TKN and TP than HCW system. More substrate layers in MHCW-1 and MHCW-2 also resulted in increase of Cu and Pb removal efficiencies, with 73.5%, 79.4%, 71.5% and 67.8%, respectively. Particularly, earthworm addition in MHCW-2 was more efficient in decreasing the concentrations of biochemical oxygen demand (BOD5), with removal efficiency over 70%.

Bibliometrics of Vietnam Publications in the Science Citation Index: general trends and comparison with other tropical countries

Introduction: The economy of Vietnam, a highly populated tropical country with a per capita gross domestic product of $ 8 000, is growing rapidly, but there are few recent studies of general scope about its scientific productivity and how it compares with other tropical countries. Objective: To identify trends in Vietnamese science and compare them with trends in other tropical countries. Methods: We extracted data about scientific papers, in all disciplines that had Vietnam as country in the Science Citation Index Expanded for the period 1991 to 2018, focusing on type of publication, language, subject, authorship, collaboration, , and citations. Results: Vietnam publishes more document types than other tropical countries, and those in this particular database are mostly in English, albeit most Vietnamese science is published in Vietnamese and not covered by the index. The primary categories were multidisciplinary materials science, mathematics, and applied mathematics. Most collaboration was done with the USA, Japan, South Korea, and France. A large number of articles were published by the Vietnam Academy of Science and Technology, and the most frequent foreign collaboration was with University of Oxford. Conclusion: the tropical countries of Latin America, Africa, and Asia studied in our project have some similarities but also crucial differences. Science is developing rapidly in Vietnam and the production of articles in Vietnamese, which represent the vast majority of research in the country but is not included in this database, should also be studied.

Removal efficiency of Fe, Zn and Ni from wastewater of academic campus using hybrid constructed wetlands

AbstractThis study was conducted to investigate the effectiveness of hybrid constructed wetland for removal of Fe, Zin and Ni from wastewater in Vietnam Academy of Science and Technology (VAST), Vietnam. Wastewater samples were collected from the in‐let, out‐let and two filters of the hybrid constructed wetland (HCW) and analyzed for iron (Fe), zinc (Zn), and nickel (Ni) using standard methods. The results indicated that the performance of the HCWs was efficient enough to remove those heavy metals from the wastewater fed to it. HCW‐1 with filter 1 was able to remove average of 41.6 % for Ni, 55.1 % for Fe, and 80.1 % for Zn. Similarly, HCW‐2 with filter 2 removed 51.7 % of Ni, 62.6 % of Fe and 79.3 % of Zn from wastewater. Thus, no significant difference in removing Fe, Zn and Ni from wastewater was observed between HCW‐1 and HCW‐2.