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Photovoltaic-thermal (PVT) technology refers to the integration of a photovoltaic (PV) and a conventional solar thermal collector, representing the deep exploitation and utilization of solar energy. In this paper, we evaluate the performance of a solar PVT cogeneration system based on specific building energy demand using theoretical modeling and experimental study. Through calculation and simulation, the dynamic heating load and electricity load is obtained as the basis of the system design. An analytical expression for the connection of PVT collector array is derived by using basic energy balance equations and thermal models. Based on analytical results, an optimized design method was carried out for the system. In addition, the fuzzy control method of frequency conversion circulating water pumps and pipeline switching by electromagnetic valves is introduced in this paper to maintain the system at an optimal working point. Meanwhile, an experimental setup is established, which includes 36 PVT collectors with every 6 PVT collectors connected in series. The thermal energy generation, thermal efficiency, power generation and photovoltaic efficiency have been given in this paper. The results demonstrate that the demonstration solar PVT cogeneration system can meet the building energy demand in the daytime in the heating season. [ABSTRACT FROM AUTHOR]

Building energy consumption monitoring and management system have been developed widely in China in order to gain the realtime data of energy consumption in buildings for analyzing it in the next state work. This paper describes a low-cost and small-sized collector based on the STM32 microcontroller, which can be placed in a building easily to implement the work of data acquisition, storage, and transmission. The collector gathers the electricity, water, heat, and energy consumption data through the RS485 field bus and stores the data into an SD card with mass storage, finally, using Internet to finish the communication and transmission to data server through TCP protocol. The collector has been used in application for two years, and the results show that the system is reliable and stable. [ABSTRACT FROM AUTHOR]

This study examined the efficacy of silver nanoparticles colloid ( AgNPC) in reducing the pathogenicity of the Bombyx mori L. ( Lepidoptera: Bombycidae) nuclear polyhydrosis virus ( Bm NPV) in silkworms. We found that the survival rate of the infected silkworms improved significantly, from 22 to 67%, following treatment with AgNPC. However, Ag NPs caused clumping of hemocytes in vivo and this was associated with slight weight loss and reduced cocoon size in the treated silkworms. The adherence of silver nanoparticles to the virus or hemocytes caused them to aggregate. In addition, by catalyzing the generation of free radicals, silver nanoparticles can perforate and break up the virus capsids, proteins, and DNA of the Bm NPVs, thus restraining their pathogenicity and improving the survival capacity of infected silkworms. [ABSTRACT FROM AUTHOR]

Averaging Pitot tubes have been widely used in many fields because of their simple structure and stable performance. This paper introduces a new shape of the cross-section of an averaging Pitot tube. Firstly, the structure of the averaging Pitot tube and the distribution of pressure taps are given. Then, a mathematical model of the airflow around it is formulated. After that, a series of numerical simulations are carried out to optimize the geometry of the tube. The distribution of the streamline and pressures around the tube are given. To test its performance, a test platform was constructed in accordance with the relevant national standards and is described in this paper. Curves are provided, linking the values of flow coefficient with the values of Reynolds number. With a maximum deviation of only  ±3%, the results of the flow coefficient obtained from the numerical simulations were in agreement with those obtained from experimental methods. The proposed tube has a stable flow coefficient and favorable metrological characteristics. [ABSTRACT FROM AUTHOR]