164 research outputs found
Impact of Service Quality Performance on Customer Satisfaction: A Case Study of Vietnam’s Five Star Hotel
To exist in highly competitive market, companies need to pay more attention in improving quality of products and services. It is necessary to maintain customers’ loyalty for sustainable future development. This research focuses on investigating the impact of service quality performance on customer satisfaction in a sample of Vietnam’s five star hotels, with a case study of Hotel X, where service quality is considered as the key to success. This study chose the SERVPERF model as a conceptual framework. Analysis of results shows that components RES-EM, ASSURANCE and RELIABLITY explain customer evaluation of perceived service quality in Hotel X. These components play important roles in service quality measurement and thus it is suggested that five star hotels generally and Hotel X in particular needs to have specific strategies to enhance these components as well as customer satisfaction
Isolation and determination of Vibrio spp. pathogen from Sciaenops ocellatus suffering from hemorrhagic disease under cage culture in Vietnam
This study was carried out to isolate and determine the Vibrio spp. from the Red drum fish (Sciaenops ocellatus) suffering from the hemorrhagic disease in Vietnam. In this study, 18 strains of Vibrio bacteria were identified from 27 samples of Red drum fish. The isolated bacterial strains were identified with the 16S rRNA sequencing method and checked for morphological, physiological, and biochemical characteristics by using the API 20E KIT. Results of the study revealed the presence of twelve strains of V. alginolyticus, three strains of V. fluvialis, and three strains of V. orientalis. All Vibrio strains have gene similarities with those on the Genbank ranging from 98.05 to 100%. The biochemical characteristics of these 18 isolates were similar and these are susceptible to tetracycline and doxycycline and entirely resistant to ampicillin, amoxicillin, and erythromycin
Verifying the Reliability of Impressed Current Method to Simulate Natural Corrosion in Reinforced Concrete
In order to accelerate the corrosion of steel reinforcement in the reinforced concrete structures for laboratory research, the impressed current method has been used widely regardless of the appropriacy of this method on the various aims of the studies relating to the deterioration of the reinforced concrete structures. The aim of this study is to characterize the influence of the impressed current method on the steel-concrete interface in the reinforced concrete to verify the reliability of this method on simulating the natural corrosion. The mill-scale of the steel reinforcement and the steel-concrete interfacial region were investigated using SEM-EDS. The results indicate that impressed current can induce the non-uniform and localized corrosion on the steel reinforcement. The corrosion products formed were likely to the natural corrosion induced by chloride environments. However, the oxidization of OH- at anode can inhibit the precipitation of corrosion products at steel-concrete interfacial region and then slowing down the formation of crack in concrete. This positively leads to an overestimation of load capacity of corroded structure and raises doubt on utilizing this technique to simulate the corrosion behavior
Determinants of Green Banking Implementation in Emerging Country: Evidence from Vietnam Banks
With the purpose of examining which factors affecting on the implementation of ‘Green Banking’ in transitional countries, the research used in-depth interview and survey questionnaire with statistics analysis with the case of Vietnam banks. The results showed that in emerging country such as Vietnam, the level of ‘Green Banking’ implementation is most affected by Human determinant, followed by Strategy, Product & Services, Culture and Technology determinant respectively. Based on findings, several implications were proposed to enhance the performance of these kind of environment friendly financial products in transitional country. By determining these factors, the banking sector in transitional countries will enhance the implementation of ‘Green Banking’ and achieve sustainable development in the context of escalating environmental contamination. Keywords: Green Banking, Implementation, Emerging Country, Human DOI: 10.7176/EJBM/11-15-04 Publication date:May 31st 201
Classification Methods for Mapping Mangrove Extents and Drivers of Change in Thanh Hoa Province, Vietnam during 2005-2018
Mangrove forests have been globally recognised as their vital functions in preventing coastal erosion, mitigating effects of wave actions and protecting coastal habitats and adjacent shoreline land-uses from extreme coastal events. However, these functions are under severe threats due to the rapid growth of population, intensive shrimp farming and the increased intensity of severe storms in Hau Loc and Nga Son districts, Thanh Hoa province. This research was conducted to monitor spatial-temporal changes in mangrove extents using Landsat and Sentinel imageries from 2005 to 2018. Unsupervised and supervised classification methods and vegetation indices were tested to select the most suitable classification method for study sites, then to quantify mangrove extents and their changes in selected years. The findings show that supervised classification was the most suitable in study sites compared to vegetation indices and unsupervised classification. Mangrove forest extents increased by 7.5 %, 38.6 %, and 47.8 % during periods of 2005 - 2010, 2010 - 2015 and 2015 - 2018, respectively. An increase of mangrove extents resulted from national programs of mangrove rehabilitation and restoration during 2005- 2018, increased by 278.0 ha (123.0 %)
Monitoring Changes in Coastal Mangrove Extents Using Multi-Temporal Satellite Data in Selected Communes, Hai Phong City, Vietnam
Mangrove forests are important and known as one of the most productive ecosystems in the tropics. They reduce the impacts of extreme events, provide important breeding grounds for aquatic species and build the resilience of ecosystem-dependent coastal communities. On the contrary, they are also known as one of the most threatened and vulnerable ecosystems worldwide, which have experienced a dramatic decline due to extensive coastal development during the last half-century. Remote sensing techniques have demonstrated a high potential to detect, identify, map, and monitor mangrove conditions and its changes, which is reflected by a large number of scientific papers published on this topic. The aim of this study was to investigate the multi-decadal changes of mangrove forests selected communes in Hai Phong city, North Vietnam, based on using Landsat and Sentinel 2 data from 2000 to 2018. The study used these continuous steps: 1) data pre-processing; 2) image classification using Normalized Difference Vegetation Index; 3) accuracy assessments; and 4) multi-temporal change detection and spatial analysis of mangrove forests. The classification maps in comparison with the ground reference data showed the satisfactory agreement with the overall accuracy was higher than 80.0%. From 2000 to 2018, the areas of mangrove forests in the study regions increased by 584.2 ha in Dai Hop and Bang La communes (Region 1) and by 124.2 ha in Tan Thanh, Ngoc Xuyen and Ngoc Hai communes (Region 2), mainly due to the boom of mangrove planting projects and good mangrove management at the local community level
Study on synthesis of carboxymethyl cellulose from pineapple leaf waste and its potential applications as a thickener
In this study, cellulose and hemicellulose were successfully extracted from pineapple leaf waste at yields of 58.8 and 16.1% by dried weight, respectively. Carboxymethyl cellulose (CMC) was synthesised from pineapple leaf cellulose by an esterification process using sodium hydroxide (NaOH) and monochloroacetic acid (MCA) with isopropanol as the supporting medium. Preparation of CMC was investigated by varying three free factors, namely, NaOH concentration, MCA dose, and cellulose size. The carboxymethylation process was optimised to produce CMC with differing degrees of substitution (DS). The highest DS of CMC (0.86) was obtained with 15% (w/v) NaOH solution, 0.6 g of MCA/g cellulose, and 50 μm cellulose. The obtained CMC were characterised by FTIR spectroscopy, SEM images and XRD diffractions. Moreover, the thickening performance of obtained CMC was also determined. The influence of the CMC’s molecular weight and degree of substitution on the viscosity of 1% (w/v) aqueous solution was tested. The experimental results suggest that the viscosity of the solution increases with increasing molecular weight and degree of substitution of CMC
NGHIÊN CỨU THÀNH PHẦN VÀ HÀM LƯỢNG CÁC LỚP CHẤT LIPID, PHOSPHOLIPID, AXIT BÉO, VÀ PHOSPHATIDYLCHOLINE LOÀI SAN HÔ MỀM CAPNELLA SP.
The total lipid content of the soft coral Capnella sp. contained 1.44 ± 0.10% of the fresh weight. In the fatty acid content, the tetracosapolyenoic fatty acids 24:5n-6 and 24:6n-3, which were the typical markers for the soft corals (the eight compartment coral), and the fatty acids that marked for symbiotic microorganism including 18:5n-3, 18:2n-6, 18:3n-6, 18:4n-3, 20:4n-3 were presented. The result of the lipid composition analysis showed that the total lipid contained polar lipid, sterol, free fatty acid, triacylglycerol, monoalkyldiacylglycerol, hydrocarbon and wax. Of these, the polar lipid displayed the highest content with 21.14 ± 1.17% of the total lipid. The phospholipid composition of the soft coral Capnella sp. contained the characteristic phospholipid subclasses of the animals of the phylum Cnidaria, including phosphatidylethanolamine, phosphatidylcholine, phosphatidylserine, phosphatidylinositol, and ceramide aminoethylphosphonate (phosphonolipid, CAEP). Of these, phosphatidylcholine exhibited the highest content with 35.53 ± 1.46% of the total phospholipid. This is the first time that the content and composition of the molecular types of the phosphatidylcholine from a Vietnamese soft coral species have been investigated and reported. By using modern mass spectrometry IT TOF LC-MS, the presence of 13 molecular types have been precisely identified, which PC 18:0e/20:4 and PC 16:0e/20:4 were the two ingredients displaying the highest content.Hàm lượng lipid tổng của mẫu san hô mềm Capnella sp. chiếm 1,44 ± 0,10% so với trọng lượng mẫu tươi. Trong thành phần axit béo có mặt các axit béo tetracosapolyenoic 24:5n-6 và 24:6n-3 là axit béo đánh dấu điển hình cho san hô mềm (san hô tám ngăn) và các axit béo đánh dấu cho vi sinh vật cộng sinh như 18:5n-3, 18:2n-6, 18:3n-6, 18:4n-3, 20:4n-3. Kết quả phân tích lớp chất lipid cho thấy trong lipid tổng có mặt các lớp chất lipid chính là lipid phân cực, sterol, axit béo tự do, triacylglycerol, monoalkyldiacylglycerol, hydrocacbon và sáp, trong đó lipid phân cực chiếm hàm lượng cao nhất (21,14 ± 1,17% hàm lượng lipid tổng). Thành phần phospholipid của san hô mềm Capnella sp. có mặt các phân lớp phospholipid đặc trưng của động vật ngành Cnidarian là phosphatidylethanolamine, phosphatidylcholine, phosphatidylserine, phosphatidylinositol, phosphonolipid là ceramide aminoethylphosphonate, trong đó phosphatidylcholine chiếm hàm lượng cao nhất (35,53 ± 1,46% tổng phospholipid). Đây là lần đầu tiên ở Việt Nam, thành phần và hàm lượng các dạng phân tử trong lớp chất phosphatidylcholine từ loài san hô mềm của Việt Nam được nghiên cứu và công bố, kết quả đã xác định được sự có mặt của 13 dạng phân tử bằng phương pháp phổ khối hiện đại LC-MS IT TOF với độ chính xác cao. Hai dạng phân tử chiếm hàm lượng cao nhất là PC 18:0e/20:4 và PC 16:0e/20:4
THỰC TRẠNG NĂNG LỰC KIẾN THỨC CÁN BỘ ĐỊA CHÍNH CẤP XÃ TRONG QUẢN LÝ ĐẤT ĐAI TẠI HUYỆN A LƯỚI, TỈNH THỪA THIÊN HUẾ
Cadastral officials play an important role in land management at the local level. Therefore, this study aims to investigate the knowledge capacity of cadastral officials in A Luoi district. We used secondary and primary data by interviewing 171 people, including cadastral officials, commune leaders, district level staff and households. In parallel, we used the 5-point Likert scale (from 1-5, corresponding to the level of competence of cadastral officials from very poor to very good) for analysis. The results show that the knowledge capacity of the cadastral officials is only average, with a score of 3.4. In particular, 4 out of a total of 4 knowledge capacities in law, procedures, time and authority implementation of cadastral officials in conciliation and land dispute resolution are at an average level. In contrast, 3 out of a total of 4 knowledge capacities in conditions for issuance of land use rights certificate, procedures, and authority implementation of cadastral officials in issuance of land use rights certificate are at a good level, and 1 knowledge capacity in law is at an average level. The research results highlighted reasons and proposed some solutions to improve the knowledge capacity of cadastral officials in the study area.Cán bộ địa chính (CBĐC) cấp xã là lực lượng nòng cốt trong công tác quản lý đất đai tại địa phương. Do vậy, nghiên cứu này nhằm đánh giá năng lực kiến thức của CBĐC cấp xã trong quản lý đất đai tại huyện A Lưới. Nghiên cứu sử dụng số liệu thứ cấp và sơ cấp thông qua phỏng vấn 171 người: cán bộ cấp huyện, lãnh đạo xã, CBĐC cấp xã, và người dân để phân tích. Đồng thời, sử dụng thang đo Likert 5 mức độ (từ 1–5, tương ứng rất chưa tốt – rất tốt) để đánh giá năng lực kiến thức. Kết quả cho thấy, năng lực kiến thức CBĐC chỉ ở mức trung bình với số điểm bình quân là 3,4. Trong đó, thủ tục hoà giải, giải quyết tranh chấp đất đai có 4/4 tiêu chí về năng lực kiến thức pháp luật; trình tự thủ tục; thời gian và thẩm quyền thực hiện của CBĐC đều ở mức độ trung bình. Trái lại, thủ tục đăng ký đất đai, cấp GCN, lập và quản lý HSĐC, 3 tiêu chí kiến thức về điều kiện; trình tự và thẩm quyền thực hiện ở mức tốt, 1 tiêu chí kiến thức pháp luật bị đánh giá ở mức trung bình. Kết quả nghiên cứu đã chỉ ra các nguyên nhân và đề xuất một số giải pháp góp phần nâng cao năng lực kiến thức của CBĐC cấp xã tại địa phương
A facile synthesis and properties of bismuth vanadate (BiVO4) photocatalyst by hydrothermal method
In this study, BiVO4 photocatalysts were synthesized by hydrothermal method using Bi(NO3)3 5H2O and NH4VO3 as raw materials followed by calcination at different temperatures in the range from 350 °C to 600 °C. The as-synthesized BiVO4 samples were characterized by a number of physicochemical techniques including X-ray diffraction (XRD), Raman analysis, Scanning Electron Microscopy (SEM), and UV-Visible (UV-Vis) light diffuse reflectance spectrophotometry. The effect of temperatures calcination on structure, surface morphology, visible-light photocatalytic activity and light absorption performance of BiVO4 was discussed in details
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