RESEARCH TRENDS ON COMMUNITY-BASED TOURISM IN THE PERIOD 2013 - 2023

Community-based tourism (CBT) has been around since the 1970s and so far, has grown in popularity in most continents. This study systematically evaluates and generalizes theoretical and practical issues on CBT based on 87 related articles published in scientific journals under the Scopus system from 2013 to 2023 through the application of content analysis methods. The results also show that research in this area has different research areas and mainly uses qualitative methods. The literature review identified a number of key themes including: (1) benefits of CBT development, (2) community and stakeholder engagement, (3) advantages and barriers in CBT development, (4) community perceptions about CBT, and (5) sustainable CBT development. The article has analyzed research trends on CBT: theory and application.  Article visualizations

ASSESSING THE SATISFACTION OF DOMESTIC TOURISTS WITH ECO-TOURISM DEVELOPMENT IN MANG DEN TOWN, KON PLONG DISTRICT, KON TUM PROVINCE, VIETNAM

Mang Den town, Kon Plong District, the Central Province of Kon Tum is one of the destinations of recent interest. With the advantage of the climate and unique high mountain ecosystem, eco-tourism development is one of the notable trends in Mang Den. Based on a survey of 130 domestic tourists to Mang Den, the study used SPSS software 20 to analyze domestic tourists' satisfaction with eco-tourism development in Mang Den. The findings of this research demonstrated the potential of ecotourism Mang Den Town as a destination for Vietnamese tourists seeking natural beauty, cultural experiences, and adventure activities. The positive satisfaction levels indicated that efforts have been made to provide a quality tourism experience. However, there is still room for improvement, particularly in infrastructure development and providing more interpretive and accommodation options. These results can guide tourism stakeholders in developing strategies to enhance ecotourism in Mang Den Town, as a Good Practice and ensure sustainable tourism growth in the Kon Plong District, Kon Tum Province.  Article visualizations

AN ANALYSIS OF TECHNICAL FACTORS AND FINANCIAL EFFICIENCY OF INTEGRATED IMPROVED EXTENSIVE SHRIMP FARMING SYSTEMS IN CA MAU PROVINCE, VIETNAM

The study was conducted from May to September 2020 to evaluate technical factors and the financial efficiency of integrated shrimp farming models. Forty-five inte grated rice-shrimp rotation farming and fortyfive integrated mangrove-shrimp farming households in Ca Mau were subjects of the survey. The results show that farm sizes were relatively large (2.47-5.30 ha). Stocking density was 4.70 ind./m2 (shrimp-rice) and 17.8 ind./m2 (mangrove-shrimp), reaching the productivity of 229.3 and 267.8 kg/ha/crop, respectively. Besides, the rice-shrimp model harvested 1.36 tons/ha/crop of rice and 11.8kg/ha/crop of crab. The mangrove-shrimp model could harvest 69.3kg/ha/crop of crab, 79.3 kg of wild shrimp and 73.5 kg of wild fish. The total production cost for the rice-shrimp model was 6.80 million VND/ha/crop, producing a profit of 33.4 million VND/ha/crop. The mangrove-shrimp model required a production cost at 19.9 million VND/ha/crop and brought a profit of 60.1 million VND/ha/crop. The productivity of shrimp was influenced negatively by stocking density, positively by cultured area (rice-shrimp model), and the ratio of forest area (for mangrove-shrimp model)

ASSESSMENT OF THE CURRENT SITUATION OF TOURISM DEVELOPMENT IN MANG DEN TOWN, KON PLONG DISTRICT, KON TUM PROVINCE, VIETNAM

This study surveyed 120 domestic tourists in Mang Den Town, using the convenience sampling method. The method used to analyze primary data was descriptive statistics. The research results have proposed six factors to evaluate the current situation of tourism development in Mang Den Town, Kon Plong District, Kon Tum Province, Vietnam including: (1) Quality of tourism services and tourism resources; (2) Perceived prices; (3) Human resources; (4) Security, order, and safety; (5) Quality of tourism services and tourism infrastructure; (6) and Tourism resources and perceived prices, in which "Human resources" is the factor that has the strongest impact on the current situations of tourism development in Mang Den Town. Through research results, the article has proposed some solutions to develop tourism in Mang Den Town more effectively in the future.  Article visualizations

Interaction Between Two Charged-Hardcore Soft Particles

During two last decades, theories of soft-particles has been introduced and developed in order to describe the behavior of bacteria and virus which can be considered as the bio-colloid particles. Soft particles are assumed to be consist of a rigid core inside an ion-permeable shell. The outer layer is always negatively charged while the core can be neutral or charged. In this paper, we investigate the interaction between two identical soft-particles with charged core. We derived the analytic formula for the interaction energy in a compact form. We showed that this interaction energy involving a screened Coulomb-like interaction term with a distance-independent coefficient. The numerical calculations showed that the interaction energy has very small amplitude and exponentially decay on the distance between the soft particles. The results indicate that it is possible to measure this kind of interaction energy when the system is put into a salt solution with the concentration low enough

MOTIVATION TO STUDY ENGLISH OF NON-ENGLISH MAJORED FRESHMEN

Motivation is regarded as an influential factor in the success of any activity. It plays a significant role in reaching the desired goals, including learning English. This research aims to analyze the students' motivation and factors affecting their motivation to learn English. The population of this study was 326 freshmen in nine faculties of natural sciences at Tay Do University. The quantitative data was collected through the questionnaire and analyzed by SPSS software. The results show that the students had motivation to learn English, but their motivation levels were not high. Additionally, the students had both intrinsic and extrinsic motivation. However, the latter was higher than the former. Moreover, the results also indicate factors affecting learners’ motivation. The research findings contribute to improving English teaching and learning quality in Vietnam in general and in Tay Do University in particular. Article visualizations

Speed profile optimization of an electrified train in Cat Linh-Ha Dong metro line based on pontryagin's maximum principle

An urban railway is a complex technical system that consumes large amounts of energy, but this means of transportation still has been obtained more and more popularity in densely populated cities because of its features of high-capacity transportation capability, high speed, security, punctuality, lower emission, reduction of traffic congestion. The improved energy consumption and environment are two of the main objectives for future transportation. Electrified trains can meet these objectives by the recuperation and reuse of regenerative braking energy and by the energy - efficient operation. Two methods are to enhance energy efficiency: one is to improve technology (e.g., using energy storage system, reversible or active substations to recuperate regenerative braking energy, replacing traction electric motors  by energy-efficient traction system as permanent magnet electrical motors; train's mass reduction by lightweight material mass...); the other is to improve operational procedures (e.g. energy efficient driving including: eco-driving; speed profile optimization; Driving Advice System (DAS); Automatic Train Operation (ATO); traffic management optimization...). Among a lot of above solutions for saving energy, which one is suitable for current conditions of metro lines in Vietnam. The paper proposes the optimization method based on Pontryagin's Maximum Principle (PMP) to find the optimal speed profile for electrified train of Cat Linh-Ha Dong metro line, Vietnam in an effort to minimize the train operation energy consumption

Isolation an agar degradation Bacillus sp. AT6 and preliminary application for seaweed saccharification

Background: Agar is a common polysaccharide found in nature. However, agar is strongly resisted to the degradation processing, leading to limitation of its application in various areas. Thus, finding an effective solution for agar saccharification significantly improves the economically effects of agar based substrates.Methods: Soil samples were collected from TienPhong Forestry Ltd. Company, ThuyXuan District, ThuaThien Hue province, Vietnam. Potential agar degrading bacteria were screened on a mineral salt agar medium. The isolate was identified based on 16S rRNA nucleotide sequence, morphological, physiological, and biochemical characteristics. Agarase production was evaluated by modification culture conditions including incubation time, shaking speed, and initial inoculum size. Molecular mass of extracellular agarase was determined by native SDS-PAGE. The effect of pH, temperature, metal ions, and organic solvents were conducted for enzyme characterization. Application of enzyme was investigated on seaweed saccharification.Result: An agar degrading bacterial strain was isolated from soils and identified as Bacillus sp. AT6. Maximal agarase accumulation obtained in the culture containing an inoculum size of 10% (v/v), shaking speed of 210 rpm, and 96 hours incubation. The agarase revealed a single band on zymogram analysis with an apparent molecular weight of 180 kDa. The optimal temperature and pH were 40°C and pH 8.0, respectively. All tested metal ions and organic solvents partially decreased enzyme activity. Treatment seaweed by agarase resulted in reducing sugars release present in the reaction, indicating the saccharification of seaweed was succeeded.Conclusion: Bacillus sp. AT6 is a new report of agarolytic bacteria that produces extracellular agarase enzymes. The present results promise strain AT6 is a great candidate for agar saccharification for industrial application

Using cassava waste of the cassava starch processing as food for raising African Nightcrawler (Eudrilus eugeniae) to obtain vermicomposting and earthworm biomass

The raising earthworms by cassava waste is a useful solution to reduce environmental pollution caused by cassava starch processing. In this study, cassava waste (including cassava peel, cassava pieces and soil) was used as a food source for raising African Nightcrawler (Eudrilus eugeniae) with three experiments: E1, earthworms were raised in crushed cassava waste right after being discharged; E2, earthworms raised in crushed cassava waste that had been incubated with organic matter after decomposing microbiological preparation for the previous two weeks; E3, earthworms were raised in crushed cassava waste that had self-decomposed naturally for the previous two weeks. The cassava waste was decomposed naturally for 4 weeks for control. The results showed that the content of organic matter, humic acid and total nitrogen in organic cassava humus, obtaining from experiments, increased compared to the control; the total organic matter content reached from 10.4%-15.7%, higher than the control (8.2%) from 1.27-1.92 times, humic acid content reached 0.6 - 0.8% and total nitrogen reached 0.3%. Experiment 3 had the highest quality of humus (organic matter content 15.7%, total nitrogen 0.3%, humic acid 0.7% and fulvic acid 0.5%). The experiment 3 also had the highest earthworm biomass (3.6kg), increasing 30.5% compared to experiment 1 and 19.4% comparing to experiment 2. Therefore, experiment 3 was proposed for application in treatment of cassava waste at larger scale. The organic humus obtaining from raising earthworms by cassava waste can be used as raw material for vermicompost production. The earthworm biomass can be used as protein-rich food for domestic animals (such as chicken, tortoise, eel, fish, etc) or used as nutritious fertilizer.Nuôi giun bằng phế liệu sắn là giải pháp hữu ích nhằm giảm thiểu ô nhiễm môi trường do chế biến tinh bột sắn gây ra. Trong nghiên cứu này, bã thải sắn (bao gồm vỏ, đầu mẩu sắn và bùn đất) được sử dụng làm nguồn thức ăn giun đất Châu Phi (African Nightcrawler (Eudrilus eugeniae) với các thí nghiệm như sau: Thí nghiệm 1: Giun quế được nuôi trong bã thải sắn nghiền ngay sau khi được loại bỏ; Thí nghiệm 2: giun đất được nuôi trong bã thải sắn nghiền đã được ủ với chế phẩm vi sinh phân hủy chất hữu cơ trong hai tuần trước đó; Thí nghiệm 3: Giun đất được nuôi trong bã thải sắn nghiền được để tự phân hủy tự nhiên trong hai tuần trước đó. Đối chứng là bã thải sắn để phân hủy tự nhiên trong 4 tuần. Bên cạnh đó, bã thải sắn nghiền còn được ủ bằng chế phẩm vi sinh phân hủy chất hữu cơ trong 4 tuần để cung cấp thêm số liệu so sánh giữa các thí nghiệm (Thí nghiệm 4). Các thí nghiệm được theo dõi trong 4 tuần. Kết quả cho thấy: Kết quả cho thấy: hàm lượng chất hữu cơ, axit humic và nitơ tổng trong mùn sắn hữu cơ thu được từ thí nghiệm đều tăng so với đối chứng: hàm lượng chất hữu cơ tổng số đạt từ 10,4% -15,7%, cao hơn đối chứng (8,2%) so với 1,27-1,92 lần, hàm lượng axit humic đạt 0,6 - 0,8% và nitơ tổng số đạt 0,3%. Trong đó, thí nghiệm 3 có chất lượng mùn cao nhất (hàm lượng chất hữu cơ 15,7%, đạm tổng số 0,3%, axit humic 0,7% và axit fulvic 0,5%). Thí nghiệm 3 cũng có sinh khối giun quế cao nhất (3,6kg), tăng 30,5% so với thí nghiệm 1 và 19,4% so với thí nghiệm 2. Do đó, thí nghiệm 3 đã được đề xuất ứng dụng để xử lý phế thải sắn ở quy mô lớn hơn. Chất mùn hữu cơ thu được từ việc nuôi trùn quế bằng phế thải sắn có thể được sử dụng làm nguyên liệu để sản xuất phân trùn quế. Sinh khối trùn quế có thể dùng làm thức ăn giàu đạm cho vật nuôi (như gà, ba ba, lươn, cá ...) hoặc làm phân bón dinh dưỡng