Advanced Materials Research Vol. 462

Abstract: After installing the monolithic muffler in the train air duct, noise is reduced, but meanwhile also increased the air duct resistance. In this paper, a monolithic muffler simulation calculation model is introduced in this paper. The pressure loss and internal flow field of the muffler are obtained by. CFD simulation. Experimental results validate the simulation method. It provides a basis for the silencer performance research of muffler.

Abstract: In this paper the resistance of one ship with installing wing and wing’s thrust have been studied in both theory and simulation by fluent software. The influence of ship resistance which from leeway angle and down helm was analyzed on the basis of the examination result of ship model test.

Abstract: Being an important node of cold chain logistics, the cold store has to be monitored and managed remotely in real-time, which is very important to operate the whole system effectively. With the help of wireless sensing network and other advanced techniques, a cold store remote monitoring system is set up, which is composed of digital video surveillance system, refrigeration control system and fire alarm system etc. Cold store is then monitored in a long range and managed systemically. The security and reliability of the cold store is guaranteed effectively.

Abstract: For the complex status of fluid flow in stator radial ventilation ducts of large turbo-generator, the temperature distribution of stator is dramatically affected by the flow status of cooling medium in stator ventilating ducts. In this paper, a new ventilating ducts structure in stator is investigated. According to fixing a wind deflector on the stator teeth adjacent to the ventilation ducts, the fluid flow status of cooling air is changed flowing in stator ventilation ducts. For this reason, the effect of heat transfer in stator is changed. Taking an air-cooled turbo-generator as an example, considering the characteristics of fluid flow and heat transfer in turbo-generator ventilation system, the three-dimensional fluid flow and heat transfer coupling model is established. Using finite volume method, three-dimensional fluid field and temperature field control equations are coupling solved. Based on this, the velocity distribution in ventilating ducts is obtained. Besides that, the velocity distribution is studied with the cooling air flows into radial ventilation ducts at different incident angles. The influences of wind deflector and incident angles on the fluid velocity and temperature distribution are analyzed. Based on that, some useful conclusions are obtained.

Abstract: Energy conservation or energy saving is one of the most important methods for reducing CO2 emissions, which is known to be associated with global warming. Although development of renewable energy sources such as solar or wind energy is necessary, we must first pay attention to the fact that enormous amounts of energy are consumed uselessly at present. Energy saving should therefore be one of the first problems to be tackled. It may not only bring reductions in CO2 emission, but also may lead to savings in expenditure on energy. This paper introduces some of the initiatives taking place in Japan aimed at energy conservation.

Abstract: The slurry water concentration measurement device based on the natural gamma-rays attenuation method was designed in this paper; this natural gamma-ray is taken from a special kind of sand beach, which contains thorium. A number of experiments were made in the laboratory. The natural gamma-rays attenuation rules were obtained when it passing through the different concentration of the slurry water. The attenuation rules of natural gamma-ray passing through different concentration of slurry water were proved in theory and in tests. This provides reliable criterion for design of slurry water concentration detector.

Abstract: Energy detection is the most commonly used algorithm in spectrum sensing. For Unknown signal, the current energy detection has shortcomings on the performance of perceiving the primary users signals in AWGN channel or fading channel. The diversity technology can receive the correlation signals which contain the same information in different branches, then merge and output the signals to reduce the probability of deep fading at the receiving terminal greatly. Therefore, we introduce diversity into the energy detection to improve the ability of detection. Simulation result shows that, it can improve the cognitive ability and obtain diversity gain through reducing the impact of fading. With the increase of diversity numbers, our method obtains lower probability of false alarm detection and performs much better than the traditional energy detection.

Abstract: This paper theoretically analyzed the distribution of gas concentration in the coal mining face inlet lane under normal ventilation and provided a theoretical basis for sensor arrangement.Monitoring the gas reflux in the coal mining face, and it is difficult to simultaneously simulate the air flow in inlet lane,the air flow in coal mining face and gas outburst in coal mining face lead to gas reflux into inlet lane from the perspective of simulation.So we calculate the range of the highest concentration in target monitoring area under certain confidence interval,and determine the location of methane sensor placement,alarm concentration and power concentration.So we can ensure gas safety within the target monitoring location.

Abstract: Recent studies have shown that the Internet-related energy consumption represents a significant, and increasing, part of the overall energy consumption of our society. Therefore, it is extremely important to look for energy-efficient Internet applications and protocols. For EPON, research on the development of protocols for higher energy efficiency at the PHY/MAC layers and the enactment of standards, and the improvement of energy efficiency of EPON devices is being conducted, while for networking equipment such as routers and switches and IDCs, research on saving the energy consumed by devices and the management of energy efficiency using power monitoring, cooling devices and metering technologies is being conducted. Against this backdrop, this study is aimed to develop methodology for the improvement of network energy efficiency in existing home/ small and medium-sized office network environments and to develop, test and evaluate an energy saving prototype for Convergence Adaptor

Abstract: A comparison is made in this paper between three high voltage gain converters. The first one is a boost converter with an additional level including a coupling inductor for increasing the voltage gain. The second is a converter that is capable to be extended to N parallel converter and the third one uses a clamp circuit to increase gain with a coupled inductor. Three converters are compared in voltage and current peak value and utilization coefficient of active switch and output diode, their ZVS and ZCS condition in the ON and OFF time and voltage gain. Finally the first converter circuit is simulated in PSpice with the two other converters input voltages and the results are compared.