Science and technology for development

Mesoporous silica nanoparticles was extracted successfully from rice straw ash (RSA) by using sodium hydroxide solution to produce a sodium silicate solution and then precipitated by adding HCl solution until the pH value about 3. The prepared products were characterized by EDX, XRD, SEM, TEM, FT-IR and BET methods. It was found that the optimal synthesis conditions for the preparation of SiO 2 nanoparticles in the weight ratio RSA/NaOH = 1/2.4, respectively and products were calcined at 550 o C in 2h. In this condition the obtained SiO 2 powders were monoclinic crystal system, mesoporous structure and large specific surface area (258.3 m 2 /g). Moreover, the performance of nanosized SiO 2 powders was tested by the adsorption of methylene blue in a batch system under different adsorbent dosage, different initial dye concentrations and different pH values. The results show that the maximum adsorption capacity was 20.41 mg.g -1 and a high pH is favorable for adsorption. Further, equilibrium isotherms of the adsorption of methylene blue on SiO 2 fit well to both the Langmuir model and Freundlich model.

Use your smartphone to scan this QR code and download this article ABSTRACT Introduction: The survival rate of oral cancer, like other types of cancers, has not been improved regardless of the early diagnosis and the introductionof advanced therapies. Treatment for oral cancer includes surgery, radiation therapy, and chemotherapy. However, the effectiveness has been limited due to recurrence and undesirable side effects. Metabolites from plant sources have been shown to be relatively less toxic and thus are considered as potential anti-cancer agents. Interestingly, curcumin isolated from the rhizome of Curcuma longa L. possesses broad-spectrum bioactivities. We focused on the synthesis of curcumin-based analogs bearing -OH/-OCH3/-F groups on the phenyl rings in our continuous efforts to search for curcumin-based anti-cancer agents. The synthesized compounds were subsequently evaluated for the cytotoxic activities against KB cancer cell line (an epidermal carcinoma of the mouth). Met...

Introduction: Olax imbricata, owning antibacterial, antioxidant, and anti-inflammatory activities, has been investigated as one of traditional diabetic plants in Vietnam. In our previous publications on Olax imbricata, the structure analysis of the isolated compounds were reported, including two phenolic compounds, three phenolic glycosidic compounds, a sesquiterpenoid tropolone and 1,2,3,4-tetrahydronaphthalene derivatives. This article described the isolation and structure elucidation of three triterpenoid glycosides isolated from the methanol extract of Olax imbricata growing in Phu Yen province. Additionally, the evaluation of inhibitory activity for a-glucosidase was performed on a pure compound. Method: The methanol extract of this plant applied the chromatographic techniques, including thin-layer chromatography and silica gel column chromatography, led to the isolation of three pure compounds. The structures of three isolated compounds were elucidated by the spectroscopic dat...

Sau khi mở rộng địa giới hành chính thông qua hợp nhất với Bình Dương và Bà Rịa-Vũng Tàu, TP.HCM hình thành một không gian công nghiệp tích hợp với năng lực vượt trội trong vùng kinh tế trọng điểm phía Nam. Bài viết phân tích vai trò mới của TP.HCM với tư cách hạt nhân điều phối chuỗi giá trị công nghiệp vùng, làm rõ thực trạng phân bố ngành nghề, mức độ chuyên môn hóa và cơ chế liên kết-lan tỏa hiện hữu. Kết quả cho thấy hợp nhất ba địa phương tạo nền tảng cho chuỗi giá trị tích hợp từ R&D, thiết kế, sản xuất đến logistics và xuất khẩu; đồng thời thúc đẩy các tỉnh chuyển từ phát triển đơn lẻ sang phân vai chức năng trong hệ sinh thái chung. Trên cơ sở đó, bài viết đề xuất mô hình tổ chức không gian sản xuất tích hợp, cơ chế điều phối liên vùng, phát triển hạ tầng kết nối và hỗ trợ doanh nghiệp. TP.HCM cần chuyển từ trung tâm tăng trưởng cục bộ sang vai trò hạt nhân và trục lan tỏa, dẫn dắt phân công sản xuất, logistics và R&D cho toàn vùng. Ưu tiên là xây dựng thể chế điều phối vùng, đầu tư hạ tầng chiến lược, kết nối chuỗi cung ứng, thúc đẩy liên kết FDI-doanh nghiệp nội địa và phát triển mạng lưới R&D vệ tinh. Nghiên cứu góp phần cung cấp cơ sở lý luận và thực tiễn cho mô hình phát triển công nghiệp vùng theo hướng tích hợp, điều phối và bền vững.

The quest for ICT usage or on-line connectivity for the benefit of library users is climaxed with unprecedented innovation changes in academic libraries even in Ogun State. Survey research design and 112 librarians in Ogun State were used. 88 respondents were determined using Krejcie and Morgan table. Multi-stage sampling technique used to select participants. Questionnaire (self-constructed) was used as data analyzed with descriptive statistics. Findings revealed big-data, virtual/e-library-services, digital interface, IT inclined staff among the innovative ideas; while IT-based-services, access to electronic catalogues, virtual references, open access repositories, mobile library services, inter-library services, and social media packages were the innovation changes in academic libraries. Lack of financial resources, poor electricity/infrastructure, poor network/lack of R&D and innovation policies were among challenges of the libraries. The study concluded that academic libraries are to cater for all innovation challenges in Ogun State. It was recommended to imbibe collaboration and adequate funding for innovation changes.

BaoQuangNgai (Báo Quảng Ngãi) - Nhà xuất bản Elsevier vừa công bố danh sách xếp hạng các nhà khoa học có ảnh hưởng nhất thế giới. Danh sách này được nhóm các nhà khoa học của Đại học (ĐH) Stanford (Mỹ) xây dựng dựa trên căn cứ khai thác cơ sở dữ liệu Scopus.

Trong 3 năm gần đây, tổng số nhà nghiên cứu khoa học xã hội và nhân văn Việt Nam góp mặt trong danh sách Stanford có sự gia tăng đều đặn.
Năm nay, 2 nhà nghiên cứu Việt Nam, gồm GS.TS.Võ Xuân Vinh và Nhà khoa học Vương Quân Hoàng - hiện đang công tác tại Trường ĐH
Phenikaa (Hà Nội) tiếp tục được ghi nhận trong danh sách các nhà khoa học có tác động trọn đời.

Kết quả này một lần nữa tiếp tục khẳng định vị thế của GS.TS.Võ Xuân Vinh trong cộng đồng khoa học quốc tế. Đây cũng là thành quả của sự đổi
mới căn bản, toàn diện giáo dục đại học và khoa học công nghệ Việt Nam ngày càng hội nhập mạnh mẽ với trình độ, hướng nghiên cứu tiên tiến
trên thế giới.

Introduction: Our previous study showed that Urena lobata L. hairy root is a potential pharmaceutical source for type 2 diabetes treatment. In order to improve the transformation efficacy and the quality of hairy roots, this study examined the effects of several factors including age, parts of plants, infection time and culture medium in inducing hairy roots in Urena lobata L. Methods: In this study, we investigated four factors to improve the hairy root induction in Urena lobata L. These factors include: age of plant (15-day-old in vitro plants, 45-day-old in vitro plants and after two subculture generations plants), different parts of plant (roots, stems, and leaves), infection time (10, 20 and 30 minutes), and culture medium (Murashige and Skoog (MS), Gamborg B5 medium (GB5) and Woody plant medium (WPM)). All experiments were repeated three times, with uninfected leaf explants of 15-day-old in vitro as the negative control. The transformation frequency and the fresh biomass of hairy roots were recorded at four weeks after infection. Results: The results showed that the optimized procedure which used 15-day-old in vitro plants, the leafy part, the infection time of 10 minutes and culture in the WPM medium was better than the original procedure. The optimized procedure achieved a transformation frequency of 100%. In addition, the fresh biomass of hairy roots formed on an explant in the optimized procedure was 3.2 times higher than the ones induced by the original procedure. Conclusion: The results showed that the optimized procedure was more effective than the original procedure in inducing Urena lobata hairy roots.

Introduction: Our previous study showed that Urena lobata L. hairy root is a potential pharmaceutical source for type 2 diabetes treatment. In order to improve the transformation efficacy and the quality of hairy roots, this study examined the effects of several factors including age, parts of plants, infection time and culture medium in inducing hairy roots in Urena lobata L. Methods: In this study, we investigated four factors to improve the hairy root induction in Urena lobata L. These factors include: age of plant (15-day-old in vitro plants, 45-day-old in vitro plants and after two subculture generations plants), different parts of plant (roots, stems, and leaves), infection time (10, 20 and 30 minutes), and culture medium (Murashige and Skoog (MS), Gamborg B5 medium (GB5) and Woody plant medium (WPM)). All experiments were repeated three times, with uninfected leaf explants of 15-day-old in vitro as the negative control. The transformation frequency and the fresh biomass of ha...

Ultrasonic irradiation (US) is a feasible and promising mechanical disruption technique for sludge disintegration, biodegradability acceleration, and anaerobic digestion enhancement. It is clear that many processing factors significantly affect cavitation and consequently the efficiency of sludge pretreatment. Therefore, assessment, comparison, and selection of optimal ultrasonic conditions for actual application of sludge pretreatment are sorely necessary. The objective of this work is to present an extensive review of evaluation approaches of sludge ultrasonic pretreatment efficiency based on physical, chemical, and biological properties of sludge.

Còn hiện tại, chàng trai lực lưỡng này thường ẳm cô nằm ngang trên hai tay đi xuống lầu tắm nắng, cô la làng, anh lại ẳm lên lầu. Đôi khi anh ẳm cô vào thẳng nệm ngủ, bỏ cô nằm lên rồi lặng lẽ đứng ngắm. Cô cảm thấy sôi nổi. Cô không đủ trí nhớ quá khứ để đúc kết về anh, nhưng hiện tại, anh ta cho cô cảm giác an toàn. Đôi khi anh bắt cô nằm sấp giả làm bàn phiếm piano, mười ngón tay anh lướt lên trên lưng. Ở những chỗ cuối câu nhạc, những ngón tay mặt chạy thật nhanh, rồi ngón út chấm dứt nhấn lên mông, khiến cô bật cười. Anh hát không hay nhưng thường chơi piano trên người cô rồi cất giọng đầy cảm xúc: “Oh, my love, my darling I’ve hungered for your touch….” Có khi anh đang lên cao: “Are you, still mine?”, chợt dừng lại la lớn: “Hạnh phúc quá.” Cô cảm thấy sôi nổi.

Diplomatic Writings外蕃通書 (also known as 外蕃書翰, which literally means “pappers and ink of diplomacy”) is a collection of diplomatic texts between Tokugawa Bakufu and the representatives of neibouring nations such as Korea, the Philippines, Cambodia, Thailand, and Vietnam. Those writings were exchanged from the seventeenth to the eighteenth century, during which the Edo period had reached its half and the Trinh and Nguyen families of Vietnam were fighting against each other. The writings were collected and edited by Kondo Juzo 近藤 重蔵 (also known as Kondo Morishige 守重) (1771 1892), who was a scholar and vassal of Tokugawa Bakufu. Diplomatic Writings consists of 27 volumes, including a volume for the content list. Diplomatic writings with Vietnam were sorted in the section named “An Nam Nation Writings” 安南國書. The collection was composed from 1808 to 1819, presented in traditional Chinese, ancient Japanese, and Katakana. The “An Nam Nation Writings” section consists of writings from Bakufu ...

Introduction: Localized high concentration electrolytes (LHCE) have been intensively studied due to their unique properties, especially in suppressing the Na dendrite formation and long-term cycling. Therefore, the low electrochemical performance of the P2-type cathode can be overcome by using LHCE. Methods: P2-type sodium layered oxides Na2=3Mn2=3M1=3O2 (M = Fe, Co, Ni) cathode materials were synthesized via a simple co-precipitation following a supported solid-state reaction. XRD and Rietveld method analyzed the phase composition and lattice parameters. SEM images observed the morphology of materials. The half-cell of three cathode were performed in LHCE consisting of 2.1 M sodium bis(fluorosulfonyl)imide (NaFSI) dissolved in 1,2-dimethoxyethane (DME) and bis(2,2,2-trifluoroethyl) ether (BTFE) (solvent molar ratio 1:2). The galvanostatic charge-discharge, striping-plating, and linear sweep voltage tests were carried out to investigate the electrochemical behaviors. Results: As-pre...

It is expected that a certain amount of natural gas from Nam Con Son Pipeline No. 2 (Stage 2) which will be received from various new gas fields (e.g. Thien Ung, Dai Hung, Su Tu Trang, Sao Vang, Dai Nguyet) and from an existing Nam Con Son Pipeline No. 1. Besides the current utilisations (e.g. for power generation and fertilizer production), the use of natural gas for petrochemical production have attracted more attention due to a value chain increase and for petrochemical development. In Vietnam, the fertilizer production from natural gas via methane value chain is only used. However, with an estimated capacity of 7-10 milion cubic meter per day (MMSCD) and the ethane concentration of 7-8%, the separation and processing of ethane (200-300 thousand ton per year) is one of potential solution for increasing the gas processing margin. In this study, therefore, an evaluation of ethane gas processing for petrochemical production was conducted based on various marketing, technical and eco...

The study was carried out to assess surface water quality and ecological risks in water bodies in the southern region of Vietnam. The study used monitoring data at 58 locations, which were collected in March, May, June, July, August, October, November, and December of 2022, with 11 water quality parameters (temperature, pH, DO, TSS, BOD, COD, NH4 +-N, NO3-N, Fe, Pb, and Cd). Comprehensive pollution index (CPI), ecological risk level, and multivariate statistical analysis methods were utilized. The values of CPI showed that the surface water quality was mildly polluted, moderately polluted, and severely polluted, accounting for 37.93, 46.93, and 15.52%, respectively. In particular, heavy pollution was concentrated in the water bodies of the Sai Gon and Vam Co Rivers. TSS, BOD, COD, NH4 +-N, and Fe had a moderate to high level of risk, while water samples contaminated with NO3-N, Pb, and Cd had a level of risk from low to safe. High levels of risk were concentrated in the water bodies of the Sai Gon River and Vam Co River, typically BOD and COD. Based on the impact level, the positions were classified into five groups, with the locations on the Sai Gon River and Vam Co River (Groups 4 and 5) being affected by various waste sources in the inner city of Ho Chi Minh City. The PCA results presented three sources, such as discharge from residential areas, soil erosion, and agriculture, that have caused water quality fluctuations and increased the impact on the water quality of water bodies. Measures to protect water resources according to environmental protection laws must be implemented soon to minimize ecological risks from water-polluting sources.

The influence of intensity Taylor vortex flow in Couette-Taylor crystallizer on the crystallization of polymorphic amino acid L-glutamic acid was investigated in cooling crystallization. Here, the L-glutamic acid was chosen as the model crystal product, where it has two kinds of polymorphism including the unstable phase α-form and stable phase β-form crystal. In cooling crystallization, the α-form crystal transformed to the β-form crystal corresponding to the phase transformation of α-form to β-form crystal. The present study found that the selective polymorphism of α-form and β-form crystal as well as the phase transformation significantly depended on the intensity of turbulent Taylor vortex flow in Couette-Taylor crystallizer. Here, the selective β-form nucleation and phase transformation were remarkably promoted as increasing the rotation speed of inner cylinder in Couette-Taylor crystallizer. By comparison with the conventional stirred tank (ST) crystallizer, the Couette-Taylor ...

The experiments were conducted to see the impact of drying methods and extraction solvents on the yield of steroidal saponins of Tribulus terrestris. The plant was dried by three different drying methods namely, solar collector drying, open sun drying and shade drying. After drying different levels (25-100%) of extracting solvent in the form of ethanol, methanol and distilled water were used for extraction. Soxhlet apparatus was used for extraction, while the gas chromatography apparatus was used in the experiment for detecting steroidal saponins in Tribulus terrestris. After extraction, four saponins identified were Tigogenin, Gitogenin, Hecogenin and Neohecogenin. The maximum yield of 61.2% was recorded for flat plate solar drying with 75% ethanol solution, followed 49.5% in shade drying with the same extraction solvent level. The lowest value of 3.1% yield was recorded for distilled water with open sun drying method. It was concluded that Both the drying methods and extraction solvent have a direct effect on the yield of steroidal saponins extracted from Tribulus terrestris. A maximum yield of almost 60% saponins may be achieved, if Tribulus terrestris is dried using a flat plate solar collector and extorted with 75% ethanol solution using GC-MS technique. Open sun drying minimizes saponins in Tribulus terrestris, while distilled water is the worse extracting solvent for extraction of steroidal saponins from Tribulus terrestris.

Seven new records of foliose lichens are reported from Chu Yang Sin
National Park of Dak Lak province in Vietnam. Morphological, anatomical and chemical characteristics are described for Heterodermia obscurata, Hypotrachyna flavida, Leptogium ulvaceum, Parmotrema sancti-angelii, Parmeliella brisbanensis, Physma byrsaeum, and Sticta marginifera.

This research was conducted to evaluate types, strength and benefits of linkages between university and industry in Ho Chi Minh City. Data was collected from both universities and businesses. We received 138 responses from faculties and centers of 26 universities (out of 30 universities surveyed) and 120 responses from 120 businesses in manufacturing, service and trading. The study identified three prevalent types of the linkage in training and technology transfer, which are: (1) Industry supports university in training; (2) University provides training and technology transfer for industry; and (3) Industry provides technological facilities for university. The level of this collaboration was found to be average in the universities group and weak in the businesses group. The benefits of collaboration are divided into two groups, namely benefits in training and benefits in research. The result also showed there is significant correlation between the strength and benefits of the linkage.

The ASEAN Economic Community (AEC) was officially established by the end of 2015. Vietnam needs to change not only the legal framework but also information systems – especially financial information – to be more transparent as required by the AEC. This study is to find factors affecting financial information transparency of Vietnam’s companies in fulfilling commitments made by Vietnam to AEC. Employing linear regression model (SPSS), we analyzed data of financial information of 240 listed companies on HOSE. Results indicated that out of independent variables, including fixed assets, firm size, total asset turnover, profit and debts, only firm size is correlated with the transparency in disclosing information of HOSE-listed companies. Based on the findings, we offered some suggestions to investors, stock exchanges, authorities and the listed companies per se to improve the financial information transparency of Vietnamese companies in general and HOSElisted ones in particular, so as t...

Nghiên cứu được thực hiện nhằm đo lường các yếu tố ảnh hưởng tới thành quả kinh doanh của các công ty niêm yết trên thị trường chứng khoán tại Việt Nam. Số liệu được thu thập từ 240 báo cáo tài chính của 20 công ty trong lĩnh vực công nghệ thông tin niêm yết từ giai đoạn 2009 - 2020. Kết quả phân tích thống kê mô tả cho thấy doanh thu, chi phí quản lý và lợi nhuận của các công ty tăng đều qua các năm, tuy nhiên tốc độ tăng của lợi nhuận cao hơn chi phí, và có sự khác biệt có ý nghĩa theo giới tính của lãnh đạo về doanh thu, chi phí quản lý và lợi nhuận. Kết quả phân tích mô hình dữ liệu bảng bằng mô hình tác động cố định (FEM), mô hình tác động ngẫu nhiên (REM) và khắc phục hiện tượng đa cộng tuyến tự tương quan và phương sai sai số thay đổi bằng phương pháp bình phương nhỏ nhất tổng quát (GLS) cho thấy các yếu tố tỷ lệ nữ giới trong Hội đồng quản trị, sự kiêm nhiệm của giám đốc, đòn bẩy tài chính, quy mô công ty theo tài sản và số năm hoạt động của công ty ảnh hưởng tới thành quả k...

From the beginning to open up the southern land, Saigon has soon represented as the center of the whole Southern with a strong pervasion. Saigon has also received the influence of Western Civilization in order to urbanize rapidly. In the nineteenth century, Saigon had a strong integration and became the motive force in leading the South Vietnam to integrate into the area and the world. The French colonialism invaded Gia Dinh and invested to establish Saigon as the administrative centre, the capital of Southern. They turned Saigon into the international trade center. Saigon changed its look and quickly became “Pearl of the Far East”.

The purpose of this study is to investigate the impact of relational benefits (confidence, social, and special treatment benefits) on satisfaction and commitment. This study also examines the impacts of satisfaction and commitment on customer loyalty. Survey data were collected from 324 customers who have used personal banking services in Ho Chi Minh City, Viet Nam. Results reveal that the relational benefits include threecomponents, namely confidence, social and special treatment benefits. Results also indicate thatconfidence,social and special treatment benefits have positive impacts onsatisfaction and commitment. Consequently, satisfaction and commitmenthave positive impacts onloyalty. Finally, implications for managers and directions for further research are discussed.

Biostimulants are products that increase plant growth, resistance to water and abiotic stresses. it compositions, such as humic acids, amino acids, Ascorbic acids and other compounds. These substances cause changes in fundamental and structural processes to influence plant growth through enhanced tolerance to abiotic stresses and increase grain yield. The objectives of the present study were to investigate the effect of the foliar application of amino, humic and ascorbic acids with mineral fertilizers on growth, yield and chemical composition of wheat. The filed investigation was carried out at Baloza Research Station of the Desert Research Center, North Sinai, Egypt during the two successive seasons of 2019/2020. The experiment was conducted in a split plot design, with three replicates. The results obtained the yield components, total antioxidants, total phenol and nutrients concentration of wheat were increased with increasing the organic acids and antioxidants rates. The beneficial effect of treatments was arranged descending by as follows; ascorbic acid (antioxidants) > amino acids > humic acid > control. The most effective treatment was Am 2 AS 2 with hum 2 (ascorbic acid at 600 ppm) with amino and humic acids (at 600 ppm), which achieved 3.4 ton/fed grains of wheat. The foliar application of antioxidants recorded higher increases of yield parameters and nutrients content in straw and grains of wheat than amino acids and humic acid, while the humic acid showed the lowest effect.

This paper examines the financial instability of Vietnam using the balance sheet approach and exploratory factor analysis. We found that the deterioration in financial and non-financial sector balance sheets as well as fiscal deficit resulted in financial instability of Vietnam, thereby offering some suggestions to stabilize the Vietnamese financial system.

Designing an effective photocatalyst for hydrogen (H2) performance under visible irradiation with a decrease the band gap energy of semiconductor has been considered as an essential aspect in boosting the performance of photocatalytic reactions. Herein, we focus on evaluating the role of doping with Ir into SrTiO3 structure fabricated by hydrothermal method for H2 generation. The crystalline characteristics the Ir-SrTiO3 photocatalyst were carried out via XRD and FE-SEM. The chemical composition and the optical properties of the Ir-SrTiO3 were classified by EDX and UV-Vis spectra, respectively. The results showcased that the dramatically improved absorbing performances of Ir/SrTiO3 specimen could be governed by the presence of Ir impurity states in the forbidden energy gap causing a decrease in energy gap of SrTiO3. This work also revealed that Ir doped into SrTiO3 exhibited excellent photocatalytic H2 evolution compared with pristine SrTiO3 (~454 and ~325 mmol.h-1.g-1 H2 production...

Trong tham luận này, chúng tôi sẽ trình bày về sự đối thoại giữa yếu tố truyền thống và yếu tố hiện đại trong một trường hợp tiêu biểu của nền văn học quốc ngữ Nam Bộ buổi giao thời -tiểu thuyết Hà Hương phong nguyệt của nhà văn Lê Hoằng Mưu. Bằng tài năng của mình, Lê Hoằng Mưu đã cho thấy sự tiếp nối các giá trị cũ trong một bối cảnh mới, đồng thời hướng đến việc đổi mới tư duy sáng tác văn họcbước chuyển vô cùng cần thiết trong quá trình hiện đại hóa văn học ở Nam Bộ nói riêng và Việt Nam nói chung.

This study is an assessment of scientist's perception regarding the role of mass media in improving their presentational skills by increased exposure on media via different training tools of mass media. The total respondents were 50 key informants from different research institutes of National Agricultural Research Centre (NARC), Islamabad. The study results revealed the highly significant difference of respondents before and after mass media exposure for confidence level of effective knowledge transfer, effective speaking level, conversational skills, interpersonal skills and motivational skills. The respondents perceived that training was satisfactory in reducing the communications hurdles (64%) and in improving the voice and tone and the speed of your conversation was 50% satisfactory. About 44% respondents described that Audio Visual Presentation Exercise was very useful activity, 58% mentioned that the voice over and Presentations for Documentaries was useful aspect, 46% responses were in favour of Recorded TV Programmes.

Mining ilmenite placer develops quickly along the coastal zone in the center area, Vietnam. In Ninh Thuan province, the mines are mostly using water for the exploitation. We simulated groundwater flow with uncertain parameters in order to answer if groundwater can supply a part of water demand for the exploitation of ilmenite by using GMS software. Unfortunately, as the results of simulation, groundwater is not enough to supply for ilmenite exploitation. The authors calculated the ilmenite reserves in several communes in Ninh Thuan and water demands. Comparison of water demands and ability of groundwater supply concludes that local government should make a sustainable strategy of water use to preserve groundwater.

In the study area, the Pleistocene aquifer has small depth. From 2009, pH was discovered with high depletion and suddent increase of aluminum in groundwater. However, in 2013, the aluminum concentratin seems to be stable. The analyzed results of mineral composition, soil, sludge, groundwater, and waste water samples showed that sources of aluminum is mainly from the local soil material, and the other is from the industrial activities. Hydrolysis of alumosilicat is the main process that put aluminum into groundwater. Factors supports the dissolution of aluminum in groundwater are hydrogeological structure, soil materials, over groundwater pumping activities, irregular casing of wells, agriculture activites, etc.

Introduction: In today's life, conductive polymers play an increasingly important role, and it is very important to research and find materials with new properties and the ability to improve the performance of devices. The synthesis of monomer units as donor-acceptor structural units in conducting polymers is extremely important. Methods: In this research, the process of synthesizing these potential monomer structural units with high efficiency has been described, including three main units, (4-hexyl-phenyl)(10H-phenoxazin-10-yl)methanone (HP-POzM) (58%, yield), 4,8-bis(hexyloxy)benzo[1,2-b:4,5-b']dithiophene (BHBDT) (90%, yield) and 5-(2-ethylhexyl)-4H-thieno[3,4-c]pyrrole-4,6(5H)-dione (EHTPD) (95%, yield). Results: The successful synthesis of monomers was demonstrated by qualitative analytical measurements of 1H NMR and TLC monitor. In addition, it is an overview of the direction that scientists are aiming for these monomer units, as D-A units in conductive polymers, appl...

In recent years, polymer clay nanocomposites are attracting considerable interests in polymers science because of many advantages. There are many scientists having researched about this kind of material and demonstrated that when matrix polymer is added little weight of clay, properties of material is enhanced considerably. Because clay is a hydrophilic substance so it is difficult to use as filler in matrix polymer having hydrophobic nature, so clay needs to be modified to become more hydrophobic. In this study, Poly (Ethylene Oxide) was used as a new modifier for clay to replace some traditional ionic surfactants such as primary, secondary, tertiary, and quaternary alkyl ammonium or alkylphosphonium cations having disadvantages: disintegrate at high temperature, catalyze polymer degradation, and make nano-products colorific…. In order to evaluate modifying effect of Poly (Ethylene Oxide), modified clay products were characterized by X-ray spectrum. And then organoclay was used to ...

The development of the coastline in Cua Viet outlet area from 1952 to 2015 was quantitatively evaluated using remote sensing technique and geographic information system (GIS). The result of the research shows that in the Cua Viet outlet area the accretion and erosion phenomena occur in a very complex manner, with erosion predominating over accretion in both scale and intensity, in which the coast sections with the largest scale and highest intensity of erosion are usually located near the outlet (both inside and outside the outlet). In the coast section inside the outlet, the erosion on the northern side occurs more intensively than on the southern side, with the erosion rate reaching -1.51 to -2.24 m/year, whereas the accretion rate is 1.15 to 1.70 m/year. The ratio between the erosional and accretional rates is 1.0 to 1.5 times. In the coast section outside the outlet, erosion occurs much more intensively, with its rate from -2.74 to -8.18 m/year, whereas the accretion rate is only 0.12 to 2.41 m/year. The ratio between the erosion and accretion is 1.0 to 38 times. Recently, the newly-built Cua Viet seawall has partially reduced the process of coastal erosion, the beach starts to consolidate in the foot area.

Sixty-six acetic acid bacteria (AAB) were isolated from fourty-five flowers and fruits collected in Hochiminh City, Vietnam. Of the sixty-six, thirty-one isolates were selected as dihydroxyacetone (DHA)-producing AAB based on the reaction with Fehling’s solution and grouped into three groups by routine identification with phenotypic features. Group I composed of fourteen isolates and was assigned to the genus Acetobacter, Group II composed of thirteen isolates and was assigned to the genus Gluconobacter and Group III was the remaining four isolates and was assigned to the genus Gluconacetobacter. Ten isolates among the thirteen isolates of Group II gave a larger amount of DHA (22.2–26.0 mg/mL) than Gluconobacter oxydans NBRC 14819 T (19.8 mg/mL), promising for the potential use in producing DHA. In phylogenetic analysis based on 16S rRNA gene sequences, six isolates of the ten potential DHA producers were suggested to be candidates for new taxa in the genus Gluconobacter.

Long range transport of ozone and its precursors can significantly impact the air quality in downwind regions. The problem of regional transport of ozone has been studied for more than three decades in Europe and U.S but not yet in Southeast Asia. This study investigated the regional scale distribution of tropospheric ozone over the Continental South East Asia Region (CSEA) of Thailand, Burma, Cambodia, Lao and Vietnam. The Models-3 Community Multi-scale Air Quality (CMAQ modeling system, driven by the NCAR/Penn State Fifth-Generation Mesoscale Model (MM5), is used for the purpose. The model domain covers the longitude range from 91'E to 111°E and the latitude range from 5°N to 25°N. Two most recent ozone episodes of March 24-26, 2004 and January 2-4, 2005 were selected which represent the typical meteorological conditions for high ozone concentrations periods of a year. The episode analysis was made based on available data from 10 and 4 monitoring stations located in Bangkok of...

Introduction: Fibroblast growth factor-2 (FGF-2) is a multifunctional protein that plays an important role in the regulation of proliferation, differentiation and migration of a variety of cells. The recombinant human FGF-2 (rhFGF-2) is currently used in stem cell culture, medicine and cosmetic products. In this study, we aim to produce secreted rhFGF-2 protein from a Pichia pastoris strain containing multiple copies of the fgf-2 gene to eliminate the disadvantages of intracellular expression systems. Methods: The recombinant Pichia pastoris carrying the fgf-2 gene was cloned by using homologous cloning method. The recombinant strains were screened by PCR reactions using specific primers for the target gene and the AOX1 promoter sequence. Moreover, the copy number of the fgf-2 gene inserted into the P. pastoris genome was identified by semi-quantitative PCR method. The secreted rhFGF-2 protein was collected in the induced BMMY medium at a final methanol concentration of 0.5%, and purified by one-step heparin affinity chromatography. The quantity and biological activity of the purified protein were determined by competitive ELISA method and MTT assay on NIH-3T3 cell line, respectively. Results: Various recombinant P. pastoris clones carrying different copy numbers of the fgf-2 gene were obtained and categorized into 3 groups: the low copy strains (4-5 copies), medium copy strains (8-11 copies), and high copy strains (more than 20 copies). Among those strains, the 4-copy one produced the rhFGF-2 protein at the highest expression level. After purification, the purity of rhFGF-2 protein reached 98.8%, and the recovery yield was 179.2 µg of protein from 200 mL of flask culture (equivalent to 850 µg/L). The purified rhFGF-2 protein showed similar biological activity on NIH-3T3 cell line with the commercial FGF-2 protein. Conclusion: The recombinant FGF-2 protein was successfully secretory expressed from Pichia pastoris, and successfully purified by only one-step chromatography.

Tiếp nối Hội thảo thứ nhất của chuỗi sự kiện AMS 2025, sáng ngày 21 tháng 3 năm 2025, Hội thảo chuyên đề 02 “Chiến lược rút ngắn thời gian giải quyết tranh chấp thông qua phương thức trọng tài và hòa giải” được tổ chức dưới sự phối hợp của Trung tâm Trọng tài Quốc tế Việt Nam (VIAC) và Trường Đại học Kinh tế - Tài chính TP. HCM (UEF). Hơn 150 đại biểu, trong đó có nhiều trọng tài viên, hoà giải viên, luật sư, pháp chế doanh nghiệp,... đã đến tham dự Hội thảo.

This research examines the influence of the PCI index and its constituent
components on non-state capital in Thua Thien Hue during the period 2007–2022, employing the autoregressive distributed lag (ARDL) methodology. The findings indicate that the PCI, transparency, informal costs, and dynamism exert positive effects on short-term investment capital. However, these impacts become negative in the long term, with
informal costs demonstrating particularly adverse effects on investment capital. The instability of PCI, PCI component indices and limited high-quality human resources are major barriers, while long-term economic growth supports investment capital. The volatility of the PCI and its components, coupled with limited high-quality human resources, poses significant challenges, while sustained economic growth facilitates
investment capital. The study underscores the significance of the PCI in evaluating investment risks and advocates for reforms in administrative procedures, enhancements in labor quality, and support for business innovation to attract sustainable investment.

Tóm tắt. Nghiên cứu này phân tích tác động của chỉ số năng lực cạnh tranh cấp tỉnh (PCI) và các thành phần đến vốn đầu tư ngoài nhà nước tại Thừa Thiên Huế giai đoạn 2007-2022 bằng phương pháp phân phối trễ tự hồi quy (ARDL). Kết quả cho thấy PCI, tính minh bạch, chi phí không chính thức và tính năng động có tác động tích cực đến vốn đầu tư ngắn hạn, nhưng chuyển sang tiêu cực trong dài hạn, đặc biệt chi phí không chính thức gây giảm mạnh vốn đầu tư. Sự bất ổn của PCI, các chỉ số thành phần PCI và hạn chế nguồn nhân lực chất lượng cao là những rào cản lớn, trong khi tăng trưởng kinh tế dài hạn hỗ trợ vốn đầu tư. Nghiên cứu nhấn mạnh vai trò PCI trong đánh giá rủi ro đầu tư, đồng thời khuyến nghị cải cách thủ tục hành chính, nâng cao chất lượng lao động và hỗ trợ đổi mới doanh nghiệp để thu hút đầu tư bền vững. Từ khóa: Chỉ số năng lực cạnh tranh cấp tỉnh; Mô hình tự phân phối độ trễ hồi quy, Vốn đầu tư ngoài nhà nước; Thừa Thiên Huế.

This paper proposes a new SVPWM algorithm for operating the three-level TNPC topology. The idea of this algorithm is approximating as close as possible the locus of actual virtual flux vector and ideal one and minimizing the numbers of switching in one switching interval to improve the efficiency of the whole system. The virtual flux vector is monitored to determine the sector and the proper non-zero voltage vectors. The performance of the converter and the comparison of different modulation methods are analyzed. Simulation and experimental results show that the proposed method provides high efficiency.

A new method to separate graphite oxide (GO) modified by polyethylene oxide (PEO) by the aid of ultrasonic radiation was developed. Modified GO (graphene oxide or single layer of graphite oxide) did not show not appear crystalline peak (d 002 ) on the X-Ray and took the form of a single layer graphene oxide on the image AFM and TEM. The exfoliated graphene oxide was reduced (RGO) to graphene by the reducing agent system HI -Acetic acid (HI-AcOH). The sheet resistance of RGO HI-AcOH is about 120 Ω/sq in the form graphene paper. In addition, FTIR, UV-Vis and Raman spectra showed more clearly about characteristics of graphite oxide, graphene oxide and RGO HI-AcOH .

This paper focuses on determining three basic factors affecting the capture of market share and expansion of the fruit product market, namely brand, sales and distribution channel and product quality. We seek to answer if there is a significant difference between fruit products which are of high quality, well-branded, distributed and sold through an established system and those without. If yes, whether it can be measured. To find out the difference, we compared prices of fruit products of strong brands and sold in an established sales and distribution system and similar fruit products without brand and sales and distribution system. To measure the impact of these three factors on the possibility in capturing market share of the products, we employed Structural Equation Modeling (SEM). The Confirmatory Factor Analysis (CFA) is utilized to inspect the extent that each factor affects the expansion of fruit product consuming market, thereby evaluating the situation and proposing solutio...

The principle of active noise control (ANC) is to produce a secondary acoustic noise which has the same magnitude as the unwanted primary noise but with opposite phase. The sum of these two signals reduces acoustic noise in the noise control area. In this paper we present a new ANC method using neural system. Moreover a new method for compensating the saturation of the power applifier is also introduced. The performance of the proposed method is compared to that of traditional methods. Simulation results are provided for illustration.