Tạp chí Khoa học và Công nghệ nhiệt đới

THÀNH PHẦN VÀ MỐI QUAN HỆ PHÁT SINH LOÀI CUA (MALACOSTRACA: BRACHYURA) Ở DẢI CÂY NGẬP MẶN ĐẦM CÙ MÔNG, PHÚ YÊN

2025-04-23T09:10:22+00:00

COMPOSITION AND PHYLOGENETIC RELATIONSHIPS OF CRAB (MALACOSTRACA: BRACHYURA) IN THE MANGROVE STRIP OF CU MONG BAY, PHU YEN Crabs, also known as true crabs (Malacostraca: Brachyura), play a key role in the structure and function of the ecosystem as well as have a great influence on other creatures in the mangrove forest. Vietnam is located in an area with a large area of mangrove forests with the highest crab species richness in the world. Previous studies in Vietnam evaluated the diversity of mangrove crab species, but the approach was mainly based on morphological characteristics. The present article presents the species composition and molecular phylogenetic relationships of mangrove crabs in Cu Mong Bay, Phu Yen province. Through two surveys, 9 species belonging to 7 genera, 6 families, 2 superfamilies of crabs were recorded, of which 2 species (Parasesarma peninsulare and Metopograpsus oceanicus) were recorded for the first time in Vietnam. Species composition does not differ between rainy and dry seasons. The phylogenetic tree based on the COI mtDNA gene sequences shows that mangrove crabs are monophyletic at the genus and family level, while polyphyletic at superfamily level with two families Dotillidae and Ocypodidae of the superfamily Ocypodoidea are located on the same branch with families in the superfamily Grapsoidea. The research results contribute to the basis for inventorying crab diversity in coastal marine ecosystems, contributing to proposals for conservation and development of crab resources in Phu Yen.

ẢNH HƯỞNG CỦA ĐỘ MẶN, CHẾ ĐỘ CHIẾU SÁNG ĐẾN PHÁT TRIỂN PHÔI VÀ TỶ LỆ NỞ CỦA CÁ MÚ LAI (♂ Epinephelus lanceolatus x ♀ Epinephelus coioides) TẠI VIỆT NAM

2025-04-24T03:54:46+00:00

EFFECTS OF SALINITY, LIGHTING MODE ON EMBRYO DEVELOPMENT, HATCHING RATE OF HYBRID GROUPER (♂Epinephelus lanceolatus x ♀ Epinephelus coioides) IN VIETNAM The study aims to evaluate the effects of salinity and lighting mode on the development of embryogenesis, hatching rate were observed of hybrid grouper ELEC (♂ Epinephelus lanceolatus x ♀ Epinephelus coioides) was carried out from July to October in 2022. This study different salinity was a completely randomized design with 5 treatment (23, 28, 31, 35 and 37 ppt) and different light time was a completely randomized design with 5 treatments (10, 12, 14, 16 and 18 hour) with 3 replicates. The diameter of fertilized eggs measured 0.857±0.150 mm. Hybrid grouper eggs undergo many times of cleavage, hatching time 18h30’ with the fertilization and hatched rates were 80-85%, respectively. Newly hatched larvae obtained 15,342; 1.35-1.6 mm in size, hatched from 18,050 fertilized eggs. The suitable salinity for incubation of hybrid grouper eggs is in the range of 31 to 35 ‰ with high hatching rate of 80 - 85% and low malformation rate of 0%. The results indicated that there were no significant effects of lighting time on the embryonic stages. Thus, the salinity should be maintained at 31 to 35 ‰, hatched rates were 80-85%. From the above results, we could conclude that hybrid grouper ELEC is predicted that artificial reproduction process and breeding product will be applied on practice in marine of Vietnam in the future.

HAI LOÀI SAN HÔ MỀM Xenia novaebritanniae ASHWORTH, 1900 VÀ Xenia lillieae ROXAS, 1933 (MALACALCYONACEA: XENIIDAE) MỚI PHÁT HIỆN Ở ĐẢO SONG TỬ TÂY - QUẦN ĐẢO TRƯỜNG SA - VIỆT NAM

2025-04-24T08:23:55+00:00

NEWLY RECORD SOFT CORAL SPECIES Xenia novaebritanniae ASHWORTH, 1900 AND Xenia lillieae ROXAS, 1933 (ALCYONACEA: XENIIDAE) AT SONG TU TAY ISLAND IN TRUONG SA ARCHIPELAGO, VIET NAM The coral in the Truong Sa archipelago (Spratly Islands) is considered of high diversity, the pervious research showed that Truong Sa archipelago has over 333 species of 71 genera and 15 families of hard corals, accounting for 74% of the species known in Vietnam and 57.6% of the coral species recorded in neighbouring South China Sea (Bien Dong) countries. However, the studying on soft coral biodiversity is extremely limited, this result was the first time two soft coral species, Xenia novaebritanniae and Xenia lillieae, were found in Spratly archipelago (Song Tu Tay/Southwest Cay). The morphological differences and sclerite structure of the soft coral specimens are described in detail. Previously, these two species were only found in the coastal waters of Central Viet Nam. Our findings not only contribute to expanding the distribution of soft corals, but also increasing the value of coral reef ecosystem biodiversity in this area.

XÁC ĐỊNH THÀNH PHẦN LOÀI RICKETTSIA TRÊN CHUỘT VÀ MỘT SỐ NGOẠI KÝ SINH TRÙNG Ở KHU VỰC ĐÓNG QUÂN MỘT SỐ ĐƠN VỊ QUÂN ĐỘI MIỀN BẮC

2025-04-24T09:10:29+00:00

DETERMINATION OF THE RICKETTSIA SPECIES IN RATS AND ECTOPARASITES COLLECTED IN SOME MILITARY UNITS IN NORTHERN VIETNAM Rickettsia, a gram-negative bacterium, and an obligate intracellular bacterium, can potentially cause fatal acute fever if not promptly detected and treated. It's often transmitted to humans by arthropods like ticks, fleas, and lice. Rodents and small mammals can serve as key hosts for various Rickettsia species. Our study aimed to identify Rickettsia species using nested PCR and gene sequencing of ompA, ompB, 17-kDa, and gltA genes based on 29 DNA samples, which tested positive for Rickettsia spp collected from mice, ticks, fleas, and lice at military units in Lang Son, Nghe An, Hai Duong, and Bac Giang, The phylogenetic analysis showed that 9/29 (31%) of Rickettsia samples belonged to Rickettsia felis species, 1/29 (3.5%) of Rickettsia samples exhibited a 99.5% ompB gene sequence similarity to Rickettsia heilongjiangensis species.

NGHIÊN CỨU ĐỘC TÍNH CẤP VÀ ĐỘC TÍNH BÁN TRƯỜNG DIỄN CỦA VIÊN NANG CỨNG ĐỊNH THỐNG PHONG TRÊN ĐỘNG VẬT THỰC NGHIỆM

2025-04-25T01:41:36+00:00

STUDYING ACUTE AND SUB-CHRONIC TOXICITY OF DINH THONG PHONG CAPSULE IN EXPERIMENTAL ANIMALS Research to evaluate acute toxicity and sub-chronic toxicity of Dinh Thong Phong capsule (DTP) in experimental animals. Acute toxicity was evaluated in mice follow the method described by Litchfield- Wilcoxon, the OECD guideline and the guideline of Ministry of Health of Vietnam; sub-chronic toxicity was evaluated in rats according to OECD 407 Guideline. In acute toxicity study, no death or toxic signs were observed with DTP capsule administration, DTP capsule did not exhibit acute toxicity up to a dose of 4800 mg/kg. In sub-chronic toxicity, DTP capsule at doses of 500 mg/kg and 1500 mg/kg were had not affect to the body weight; some hematological parameters; AST, ALT, albumin, total cholesterol and creatinine levels; and macroscopic, microscopic images of liver, spleen and kidney of rats when taken continuously for 56 days.

NGHIÊN CỨU TỔNG HỢP VÀ KHẢO SÁT CÁC YẾU TỐ ẢNH HƯỞNG TỚI KHẢ NĂNG HẤP PHỤ 2,4-DICLOPHENOXYACETIC AXIT CỦA VẬT LIỆU CACBON AEROGEL/Fe3O4

2025-04-25T02:52:36+00:00

STUDY ON SYNTHESIS AND SURVEY EFFECTS OF FACTORS TO ABILITY ADSORPTION 2,4-D OF COMPOSITE MATERIALS OF CARBON AEROGEL/Fe3O4 In this study, materials graphene oxide (GO), magnetite nanoparticles (Fe3O4), carbon aerogel (CA), composite of carbon aerogel/Fe3O4 (CA/Fe3O4) were prepared success. Materials were chacracterized by X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR) and field emission scanning electron microscopy/energy dispersive X-ray spectroscopy (FESEM/EDX). The obtained results show that the Fe3O4 have a cubic crystal structure and have a nanoparticle's size (50-100 nm); the nano Fe3O4 were well dispersed with the carbon aerogel to form the composite materials of CA/Fe3O4. The effects of initial 2,4-D concentrations, contact time, pH values on the 2,4-D adsorption were investigated from batch tests. The experimental data were analyzed by Langmuir, Freundlich models of adsorption. The 2,4-D adsorption on the material was fitted to Freundlich isotherm and the maximum adsorption capacity was found to be 102.04 mg/g.

DỰ BÁO TUỔI THỌ CÁC HỆ SƠN BẢO VỆ KIM LOẠI KHI SỬ DỤNG TẠI CÁC KHU VỰC KHÍ HẬU NHIỆT ĐỚI VIỆT NAM

2025-04-25T03:46:59+00:00

SERVICE LIFE PREDICTION FOR METAL PROTECTIVE PAINT SYSTEMS USED IN TROPICAL CLIMATE AREAS OF VIETNAM This paper presents the results of accelerated test of 8 commonly used metal protective paints under 2 modes of accelerated test simulating atmosphere at 2 testing stations of Joint Vietnam-Russia Tropical Science and Technology Research Center and by using previous test data of natural test as the basis for predicting service life. Corrosion protection parameter of paints is taken as a measure of service life. Acceleration testing and predicting methods are carried out according to the set of 3-standards GOST 15150-69, GOST 9.401-2018 and GOST 9.104-79 of the Russian Federation. Research shows that this set of 3-standards is a reliable tool to predict the service life of most metal protective coating systems working in tropical climate conditions in Vietnam (with error < 10%). The research results have high practical value and are guidelines for selecting paint suitable for conditions and use requirements.

GIẢI PHÁP BẢO QUẢN MỘT SỐ CHỦNG LOẠI TÊN LỬA HẢI QUÂN

2025-04-25T06:55:44+00:00

METHODS OF PRESERVING SOME TYPES OF NAVY MISSILES This paper presents a solution to preserve some types of Navy missiles with storage bags combined with circulating dehumidification method using TKK-HQ1 device. Three problems have been resolved. Firstly, the air tight fabric available on the market has been selected to replace the K18-4 fabric with equivalent quality. Second, the type of air-tight lock that meets the requirements has been selected. Third, has successfully manufactured storage bags for P-21, P-22 and P-28, P-28M missiles and TKK-QH1 dry air blower. The test results show that the system operates stably, the humidity in the storage bags is maintained in the range of 40% to 60%. The system is easy to use and has a low cost.

ẢNH HƯỞNG CỦA CHẤT LIÊN KẾT MẠCH GLUTARALDEHYDE ĐẾN TÍNH CHẤT VẬT LIỆU ĐIỆN CỰC CHO SIÊU TỤ ĐIỆN CÓ NGUỒN GỐC TỪ CHITOSAN

2025-04-25T08:19:31+00:00

EFFECT OF CROSS-LINKING AGENTS ON THE PROPERTIES OF CARBON-BASED ELECTRODE MATERIAL DERIVED FROM CHITOSAN FOR SUPERCAPACITOR The fabricated ACCS material has a porous structure and is doped with heteroatoms (Nitrogen) inherent in the structure of chitosan. Glutaraldehyde support forming interconnected carbon skeletons, as well as creating a pore structure suitable for electrode materials for supercapacitors. ACCS-2 material has a specific surface area of 2341 m2.g−1 and a pore volume of 1.22 cm3.g−1. ACCS-2 electrode material has a capacitance of 209 F g−1 at a current density of 0.5 A.g−1. Furthermore, it is capable of retaining nearly 93% of the original capacitance and the coulumbic efficiency remains above 92% after 5000 cycles. From the above research results, carbon materials derived from chitosan is expect to have potential for application as electrode materials for supercapacitors and energy storage systems.

ỨNG DỤNG KỸ THUẬT ĐIỆN CAO ÁP TẠO PLASMA TRONG DUNG DỊCH TỔNG HỢP HẠT NANO SELEN VÀ ĐÁNH GIÁ KHẢ NĂNG KHÁNG KHUẨN CỦA VẬT LIỆU

2025-04-26T02:29:43+00:00

SYNTHESIZING SELENIUM NANOPARTICLES USING HIGH VOLTAGE PLASMA GENERATION TECHNIQUE IN SOLUTION, EVALUATING THE ANTIBACTERIAL ABILITY OF THE MATERIAL Selenium is an essential micronutrient for human, animal, and microorganism health. The biocompatibility, bioavailability, and low toxicity of selenium nanoparticles (SeNPs) have recently sparked the interest of scholars. Electrochemical plasma is a novel electrical discharge in a liquid environment, such as an aqueous solution or an organic compound. In this study, electrochemical plasma was utilized to synthesize SeNPs with a size range of 60 to 80 nm in water-ethanol mixtures. UVVisible Spectrophotometry (UV-Vis), X-Ray Diffraction (XRD), Raman spectroscopy, Scanning Electron Microscope (SEM), Energy dispersive spectroscopy and mapping (EDX), and X-ray photoelectron spectroscopy (XPS) were used to characterize the synthesized SeNPs. The obtained SeNPs showed good antimicrobial properties when testing with bacteria Staphylococcus aureus, Escherichia coli. The SeNPs showed effective bioactivity with inhibition zones of 18, and 25 mm against E. coli, and S. aureus, respectively, at a SeNPs dose of 150 µL (concentration of 300 ppm).

ĐÁNH GIÁ KHẢ NĂNG LƯU GIỮ NỘI VI LOÀI NHUM SỌ Tripneustes gratilla (LINNAEUS, 1758) Ở ĐẦM BÁY, VỊNH NHA TRANG

2025-04-26T04:17:16+00:00

Trong phạm vi bài báo này, kết quả được trình bày là quá trình lưu giữ nhum sọ từ tháng 11/2022 đến tháng 03/2023 tại Đầm Báy, vịnh Nha Trang.

XÂY DỰNG QUY TRÌNH XÁC ĐỊNH CARBON TỔNG VÀ CARBON HỮU CƠ TỔNG SỐ TRONG BỤI KHÔNG KHÍ XUNG QUANH PM10

2025-04-26T04:48:26+00:00

Nghiên cứu đã xây dựng được quy trình phân tích hàm lượng TC, TOC trong bụi PM10 trong không khí xung quanh với các điều kiện tối ưu, phù hợp với trang thiết bị của phòng thí nghiệm. Giới hạn phát hiện (MDL) của phương pháp phân tích TC, TOC lần lượt là 1,3 µg/Nm3 và 1,2 µg/Nm3. Kết quả so sánh liên phòng giữa 2 phòng thí nghiệm có kết quả tương đồng nhau (p-value > 0,05). Nghiên cứu bước đầu đánh giá thành phần carbon của hạt bụi PM10, đồng thời cũng mở ra hướng nghiên cứu thành phần ở cấp hạt thấp hơn (PM2.5), góp phần vào quá trình nghiên cứu và đánh giá các tác động của ô nhiễm không khí, đặc biệt là của các hợp chất hữu cơ có trong không khí đến sức khỏe con người.