Abstract: Urban agriculture is a highly concerned issue during the period of rapid urbanization in Vietnam. Research aims to propose a cultivation process for cultivating oyster mushrooms, utilizing coffee grounds from coffee businesses as a resource. This approach promotes circular economy principles, generating economic benefits for households while protecting the environment and being suitable for urban areas. The study conducted experiments on grey oyster mushrooms using different mixtures of coffee grounds and rubber wood sawdust at the following ratios: 0%, 25%, 50%, 75%, and 100% coffee grounds/rubber wood sawdust, filled into bags with a weight of 1.2kg. The research results showed that disease infection rates were mild in the 0% and 25% mixture ratios, while the remaining ratios exhibited moderate to severe infection levels. The highest mushroom yield was observed in the mixture ratio of 25% coffee grounds, with an average number of mushroom ears per bag reaching 29.7grams/bag, the dry weight is 63.8 grams/bag, with an average size ranging from 3 to 14 cm and a moisture content of 79.5%. The fastest colonization speed on the substrate is achieved by 25%, 50% coffee grounds blend, which fully colonizes the bag in a period of 25 to 35 days, the shortest time compared to the 75% and 100% coffee grounds blends, which take 40 to 45 days. The experimental results show that the 25% coffee grounds: 75% rubber sawdust blend is suitable for urban mushroom cultivation models and can be expanded on a large-scale farm, contributing to minimizing environmental pollution, utilizing limited urban land area, and providing high economic efficiency.
Primates play a huge role in biomedical research. They are raised for medical research and to test new vaccines before being used for humans. The yellow-cheeked gibbon (Nomascus gabriellae) is an endemic mammal of Vietnam, included in the Vietnam Red Book 2007, and described in the IUCN Red Book 2009. This species is an endangered species found only in a small region of Indochina, and its populations have declined in most known sites. The purpose of this article is to present an overview research on taxonomy, identification, reproduction, behavior, ecology, distribution, population, and conservation status of this species. The overall results are intended to support the conservation of this rare endemic animal species and provide reference in related biomedical research.
Through assessment of surface water quality at Siep stream in Di An city, Binh Duong province. Siep Stream is a level 1 tributary that flows into Dong Nai River. Dong Nai River is currently being exploited and used for domestic water supply purposes. Sampling location of Siep stream at the culvert on National Highway 1K from January 2022 to November 2023, through statistical monitoring data compared with QCVN 08-2023/BTNMT (level A) and QCVN 08: 2015/BTNMT (column A2) - National technical regulation on surface water, it shows that the parameters increase or decrease without stable, most tend to increase with about 86.9% COD exceeding the standard 1.0 ÷ 7.8 times, 95.6% SS parameters exceeding the standard 1.8 ÷ 30.4 times, 95.6% N-NH4 number exceeds the standard of 0.16 ÷ 21.8 times, 52.1% of N-NO2 parameters exceed the standard by 0.52 ÷ 8.9 times, 65.2% of P-PO4 parameters exceed the standard by 0.35 ÷ 6.25 times, 91, 3% of Colifrom parameters exceeded the standard of 1.0 ÷ 3.3 times. The WQI (water quality index) results show that the surface water quality of Siep stream is mostly average, this result is not suitable for domestic water supply purposes, there needs to be solutions to improve water quality at the area Siep Stream.
In this note, we prove a unique result for a nonlinear differential equation concerning a Nagumo-type source. An example is given to illustrate the theoretical result.
Political culture is a complex concept, containing many different understandings and research methods from many different perspectives. Studies of political culture have emerged since World War II, and scholars continue to discuss this concept in the context of many inconsistent views in the academic world because of the interdisciplinary nature of this concept. Based on research results on the definitions, functions, and relations of political culture with organizational culture and management culture; by secondary qualitative data analysis method; this article concludes that the most similar point between the definitions of "political culture" is the recognition of the relationship between political culture and the state, with society with nation-state and class, the recognition that the inner meaning of political culture always includes dynamic elements as well as static elements, and acknowledges that the subject of political culture can be studied at all three levels of the individual, institution (organization), and community (state, nation).
Currently, to make human life more convenient and easier, many utility services have been provided. Among them, online food ordering applications with high coverage and diverse forms become prominent. This research aims to examine the factors influencing the intention of using online food ordering applications among students in Ho Chi Minh City. Using a multivariate linear regression model and the Ordinary Least Squares method (OLS), the research team analyzed primary data based on 120 valid survey sheets collected from students studying in HCMC. The research results indicate that there are seven factors influencing the intention to use (ITU) online food ordering applications, including: (1) Ease of use (EOU), (2) Convenience (CV), (3) Aesthetic appeal (AA), (4) Price expectations (PE), (5) Social influence (SI), (6) Perceived risk (PR), and (7) Habits (HB). Among them, the three factors with the greatest impact on the students’ intention are ease of use, aesthetic appeal, and social influence. Based on the test results, the study proposes a management implication to help food delivery service providers enhance service quality, suggest development directions, and make suitable strategies for potential target customers.
Keywords: food delivery service providers, food ordering applications, management implication, students’ intention
In recent times, there has been a rapid surge in the advancement of technologies associated with Unmanned Aerial Vehicles (UAVs), particularly in the domains of sensors, networking, and processing. Consequently, substantial investments from both governments and industries have been directed towards the exploration of UAVs, aiming to enhance their performance for secure and dependable deployments. The evolution of design methodologies and the exploration of UAV systems have transitioned from single UAV applications to encompass multi-UAVs and cooperative UAV systems. These systems necessitate a heightened level of coordination and collaboration to execute tasks, demanding innovative networking models, approaches, and mechanisms tailored for highly mobile nodes, encompassing numerous intricate parameters and constraints.
The present paper provides comprehensive insights and conducts a meticulous examination of UAV communication protocols, networking systems, architectures, and applications. Furthermore, it delves into UAV solutions while underscoring critical technical challenges and unresolved research issues that warrant further investigation and dedicated research and development endeavors. In this paper, we study some problems and solutions for The Command and Control (C2) aspect of UAV communication systems. We also give some directions for research in near future.
Investigating the characteristics of the three-step sorption of Sc on armchair silicene nanoribbons is the aim of this study. Since absorbed energy is the largest of the bridge, hollow, valley, and top positions, the hollow position is selected first. The structural state of the second step has an energy of adsorption of 4.18 Å and a bond length of 2.36 Å for Si-Si. Finally, ASiNRs with a high Sc atom had their 1.25 Å surface modified. Adsorbed ASiNRs resulted in new materials with semi-metal and magnetic characteristics, suggesting potential use in spintronic and electronic devices in the future.
The Covid pandemic and economic recession have seriously affected the business and production activities of businesses. This article proposes the application of Lean manufacturing to identify waste and propose solutions to reduce waste at Protrade Garment Joint Stock Company. In this study, tools in Lean and JIT were used to identify waste in the production process and calculate the cost of losses caused by waste. Research results have reduced waste due to transportation and help Protrade Garment Joint Stock Company increase its competitiveness in the market.
Keywords:Lean, waste, cost , 5S.