Sampling

The paper presents results on tree snails based on samples collected from various parts of Vietnam during the period of 2008–2022. As a result, 14 Amphidromus species were recorded, which increased the diversity of the genus in Vietnam to a total of 27 species. Four species were new country records including Amphidromus atricallosus perakensis, Amphidromus leucoxanthus, Amphidromus perversus natunensis, and Amphidromus areolabiatus. Almost all 14 species were found in the south, while only Amphidromus roseolabiatus was recorded in the north.

19p dianmotminh02 03-05-2024 2 1   Download

In this study, we evaluated and compared the effectiveness of four different protocols (D, MJ, MA, and S) for separating MPs from water of different types (brackish, marine, and river). Known combinations of MP particles (polyethylene (PE), polyethylene terephthalate (PET), polystyrene (PS) and polyvinyl chloride (PVC) with size ranging between 150 μm and 700 μm were spiked into water samples. Our results showed that the average recovery effectiveness of microplastics using four studied methods ranged from 53% to 86%.

10p dianmotminh02 03-05-2024 3 2   Download

In this study, we used the reliable GC-FID/MS technique to analyze the methyl ester derivatives of 37 different kinds of fatty acids. The results showed that high saturated fat concentration in all samples was mostly palmitic acid, whereas the low unsaturated fatty acid content in the cis form was primarily oleic acid and linoleic acid. The amount of monounsaturated and polyunsaturated fats is quite low.

6p dianmotminh02 03-05-2024 1 1   Download

The 3D printing PMMA/ZrO2 filaments with a diameter of 1.75±0.05 mm were fabricated by using a single-screw extruder at temperatures of four heating zones of 190, 200, 210, and 210°C. Testing samples were prepared from the extruded filaments by using a fusion deposition modeling 3D printer and a Haake MiniJet piston injection molding machine. Fourier transform infrared spectroscopy, mechanical properties, field emission scanning electron microscopy (FESEM), differential scanning calorimetry, and thermogravimetric analysis of the filaments were investigated.

9p dianmotminh02 03-05-2024 1 1   Download

Nano-hydroxyapatite/starch composite was synthesized using in situ precipitation. Starch concentration effect on the structure of composite was examined. Characterization of the obtained samples, The X-ray diffraction and Fourier transform infrared spectroscopy demonstrated the purity of the formed nano-HA in the starch matrix. Morphology studies of the samples, checked by field emission scanning electron microscope and transmission electron microscope, show the effects of starch on the size, shape, and morphology of hydroxyapatite nanoparticles.

6p dianmotminh02 03-05-2024 6 1   Download

The studies involving water bugs (Hemiptera) biodiversity and ecology are very few and have mainly focused on taxonomy. We conducted research and evaluation of diversity indexes of water bugs (Hemiptera) in different landscapes including forest habitats, agricultural lands, ponds, streams from 16 sampling sites in Bac Kan, Lao Cai, Ninh Binh and Ha Tinh provinces. As a result, a total of 43 species of 23 genera of 10 families were recorded.

14p dianmotminh02 03-05-2024 4 2   Download

The sediment quality assessment showed that trace element concentrations were lower than the limited values in the sediment quality guideline (QCVN 43:2017/BTNMT). According to the Igeo index, the sediments were not polluted by Cu, Pb, Zn, Cr, Fe, and As but were likely polluted by Hg and Mn in some sampling sites. Therefore, it is necessary to invest the future studies to assess the Hg and Mn concentration levels in these sites to protect the marine environment.

12p dianmotminh02 03-05-2024 6 1   Download

This paper proposes the design of a neural network controller based on a sample controller for controlling the trajectory-tracking motion of a differential drive mobile robot (DDMR). Firstly, the trajectory tracking model for DDMR is established based on position error. Next, a perceptron neural network is designed with three hidden layers to control the trajectory tracking of DDMR.

13p dianmotminh02 03-05-2024 7 5   Download

The limitation of this research is few time to collect data for this reason the sample size was small for this research, it is recommended to have bigger sample size for future studies. The study is a contribution to the new business houses to understand their business in much organized way and I is must to have the marketing strategy for a successful business venture.

11p longtimenosee10 26-04-2024 3 2   Download

This study summarizes a sample of the managers of the Iraqi cellular communications company with 84 employees. The company is a service organization responsible for providing integrated telecommunications services. As a management system that uses human, technical, material and financial resources, its size and value increase in line with technical progress. The demand for telecommunication services is increasing for several factors, the most important being the only means available to the majority and to the increase in population.

6p longtimenosee10 26-04-2024 4 1   Download

Institutions are accelerating to achieve a sustainable competitive advantage in supply chain, its range is expanding to find the tools to help them achieve this purpose, and the growing need for these organizations to understand their current status as well as their potential. Therefore, organizations always depend on information systems to process transactions, develop products, access a large proportion of their budgets to support their operational and commercial activities, and how to acquire knowledge for business owners to access these investments.

16p longtimenosee10 26-04-2024 2 1   Download

The importance of supply chain governance mechanism has grabbed the attention of academia due to massive corporate scandals in 21st century. The following study is aimed to investigate the supply chain governance mechanism in Iraqi corporations at first stage and develop the relationship between supply chain governance with quality of financial reporting at second stage. The sample of this study is consists of listed Iraqi companies between the time period of 2009 to 2016.

4p longtimenosee10 26-04-2024 5 1   Download

The purpose of this research is to Investigating the Effect of losing customers and reputation on the supply chain of brand marketing (case study: Pegah products consumers). The present study is an applied research. The statistical population of this research is the customers of Pegah products. Given the unlimited size of the statistical population, the sample size is 384 people.

3p longtimenosee10 26-04-2024 4 1   Download

The data collected using purposive sampling and Slovin formula. The hypothesis of this research is tested by multiple linier regression. The research results showed that the variable site design, informative, security and communication have a partialy significant effect to the online shopping customer satisfaction, while the convenience of shopping variable is not significant. This understandable because each online store has different system and procedure that incovenience for consumers.

9p longtimenosee10 26-04-2024 4 1   Download

The main objective of this study is to examine the effect of intellectual capital, debt policy, company size, supply chain and liquidity on earnings per share and dividends per share as intervening variables in companies registered in the LQ 45 stock market index that consists of 45 companies for the 2014-2016 period in Indonesia. Using a purposive sampling method obtained data (panels) of 60 observation data from 20 companies.

7p longtimenosee09 08-04-2024 4 1   Download

This study intended to determine the influence of knowledge of malaria epidemiology and water bearing plant and public participation in malaria prevention and control in Boki local government area, Cross River State. The study was analysed based on the hypotheses postulated to guide the study. The descriptive survey research design was used, 100 samples were used and the stratified random sampling and simple random technique was adopted to select the respondent for the study.

10p vikissinger 21-12-2023 7 2   Download

Bài giảng "Các phương pháp định lượng 1 (Học phần: Xác xuất thống kê) - Thống kê suy luận" trình bày các nội dung chính sau đây: mô hình thống kê (statistical model); ước lượng điểm (point estimation) và phân phối mẫu (sampling distribution); tính chất cần thiết của ước lượng điểm; định lý giới hạn trung tâm (the central limit theorem);... Mời các bạn cùng tham khảo nội dung chi tiết!

27p kimphuong1144 04-12-2023 7 3   Download

The study is carried out to meet the following aims: To provide in-depth information on the types of extracurricular activities learners participate in, as well as how they engage themselves in such outdoor activities. To give a brief overview on outdoor activities and introduce samples of extracurricular activities out of the class.

83p tueman07 21-08-2023 14 3   Download

Compare to other documents, our study was for the first time validated the quality criteria of ICP-MS for analyzing nineteen metal levels in wastewater samples. The application of this method was then tested by analyzing nineteen metal levels in twenty-three wastewater samples in the Tham Luong Canal in Ho Chi Minh City. Based on these results, the correlation of the concentration of these metals in wastewater samples was determined.

7p viengels 25-08-2023 7 3   Download

Mục tiêu nghiên cứu của đề tài "Phân tích biểu cảm mặt người dùng mạng nơ ron tích chập" nhằm đề xuất cách tiếp cận học sâu kết hợp với các kỹ thuật tiền xử lý như: chuẩn hóa hình ảnh và tăng cường mẫu học bằng các phép rotation, translation và scaling trên ảnh thật (synthetic training-samples generation), với hy vọng nâng cao độ chính xác trên các bộ dữ liệu thử nghiệm đã chọn.

78p trankora03 05-08-2023 16 9   Download