In this paper, a solar tracking device that can continuously track the sun by adjusting the direction and angle of the solar panel in real time is designed and fabricated to improve the power generation efficiency of the solar cell panel. The mechanical parts as well as the automatic control part of the passive sun-tracking system are described, and the efficiency enhancement with the sun-tracking solar panel is characterized in comparison with the fixed panel system. The test results show that in the spring season in Qingdao city of eastern China, the sun-tracking system can improve the solar cell power generation efficiency by 28.5%–42.9% when comparing to the direction and elevation angle fixed system in sunny days. Even in partly cloudy days, the PV power output can increased by 37% with using the passive sun-tracking system. Economic analysis results show the cost-benefit period is about 10 years, which indicates that the passive sun tracking device can substantially contribute to the solar energy harvest practices.
In recent years, information technology and social media has developed very rapidly and has had an impact on government services to the public. Social media technology is used hugely by several developing countries to provide services, information and promote information disclosure in its government to improve its performance. This study aims to build role of social media technology concept as a public service delivery facilitator to the public. Furthermore, it discusses the potential impact of social media use on government culture. To achieve the goal, this study combines two theories, namely government public value theory and green smart city with four variables, namely quality of public services, user orientation, openness, and greenness. These variables are used as the foundation for data collection through in-depth interviews and group discussion forums. In-depth interviews are utilized as data search and direct observation. The informants consist of several government elements, including heads of regional apparatus organizations, heads of public service malls and Palembang city government employees. The study revealed that the Palembang government has several social media-based public services that have quality of services, user-orientation, openness, and environmental friendliness.
Heat transfer augmentation procedures, such as Heat Transfer Enhancement and Intensification, are commonly used in heat exchanger systems to enhance thermal performance by decreasing thermal resistance and increasing convective heat transfer rates. Swirl-flow devices, such as coiled tubes, twisted-tape inserts, and other geometric alterations, are commonly used to create secondary flow and improve the efficiency of heat transfer. This study aimed to explore the performance of a heat exchanger by comparing its performance with and without the use of twisted-tape inserts. The setup consisted of a copper inner tube measuring 13 mm in inner diameter and 15 mm in outer diameter, together with an outer pipe measuring 23 mm in inner diameter and 25 mm in outer diameter. Mild steel twisted tapes with dimensions of 2 mm thickness, 1.2 cm width, and twist ratios of 4.3 and 7.2 were utilised. The findings indicated that the heat transfer coefficient was 192.99 W/m² °C when twisted-tape inserts were used, while it was 276.40 W/m² °C without any inserts. The experimental results closely aligned with the theoretical assumptions, demonstrating a substantial enhancement in heat transfer performance by the utilisation of twisted-tape inserts. The study provides evidence that the utilisation of twisted-tape inserts resulted in a nearly two times increase in the heat transfer coefficient, hence demonstrating their efficacy in augmenting heat transfer.
Proposed herein is an environment-friendly method to realize oil/water separation. Nylon mesh is exposed to atmospheric pressure plasma for surface modification, by which micro/nano structures and oxygen-containing groups are created on nylon fibers. Consequently, the functionalized mesh possesses superhydrophilicity in air and thus superoleophobicity underwater. The water pre-wetted mesh is then used to separate oil/water mixtures with the separation efficiency above 97.5% for various oil/water mixtures. Results also demonstrate that the functionalized nylon mesh has excellent recyclability and durability in terms of oil/water separation. Additionally, polyurethane sponge slice and polyester fabric are also functionalized and employed to separate oil/water mixtures efficiently, demonstrating the wide suitability of this method. This simple, green and highly efficient method overcomes a nontrivial hurdle for environmentally-safe separation of oil/water mixtures, and offers insights into the design of advanced materials for practical oil/water separation.
Doping by athletes is a serious problem plaguing competitive sports around the world. Reviewing history, the traditional British endurance race is the source of doping in modern sports. Science and technology is the main driving force of social development. The competitive level of human beings has reached the height close to the limit of human potential, and it is difficult to improve sports performance by using conventional training methods, which makes athletes seek external and powerful means to improve their performance, and the achievements of natural science just meet this demand. This has also become a seemingly unavoidable phenomenon. On the one hand, this practice has been condemned by the public, on the other hand, it has become a serious problem in sports.
In the process of English learning, primary school English is an important period of enlightenment. However, teachers’ old-fashioned teaching methods and obscure teaching contents make primary school students less interested in learning English, which will affect students’ entire English learning career. Under this educational background, the education department should analyze the existing problems in English teaching methods, teaching contents and teaching concepts based on the current situation of English teaching in primary schools, aiming to improve the interest of English teaching in primary schools through effective strategies.
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