A discussion on performance parameters for solar-aided absorption cooling systems

The overall performance of solar-aided heat pumps or air conditioners may be evaluated by first law based efficiency (i.e. COP), or second law based exergy-efficiency (effectiveness). However, it is usually desirable to separately investigate the contribution of solar energy. For this purpose, a parameter called the Fraction of Non-purchased Energy and defined as the ratio of solar originated (i.e. non-purchased) heat input to the total energy input is often used. While this ratio is satisfactory for a heating mode, it does not have a clear meaning during the cooling mode. This is because the value of this ratio could be high, either because solar energy is used effectively or possibly wastefully. Therefore, another parameter must also be defined and used to show how effectively the solar energy is used by the system. The ratio proposed for this purpose is to be named the Solar Performance Coefficient (SPC) and is defined as:

SPC=1−(Q_aux/Q_load)

where Q_aux is the total auxiliary energy input, including pump works, and Q_load is the cooling provided by the system.     

Deciding unique decodability of bigram counts via finite automata

We revisit the problem of deciding by means of a finite automaton whether a string is uniquely decodable from its bigram counts. An efficient algorithm for constructing a polynomial-size Nondeterministic Finite Automaton (NFA) that decides unique decodability is given. This NFA may be simulated efficiently in time and space. Conversely, we show that the minimum deterministic finite automaton for deciding unique decodability has exponentially many states in alphabet size, and compute the correct order of magnitude of the exponent.     

A novel approach for estimating heat transfer coefficients of ethylene glycol–water mixtures

Ethylene glycol–water mixtures (EGWM) are vital for cooling engines in automotive industry. Scarce information is available in the literature for estimating the heat transfer coefficients (HTC) of EGWM using knowledge-based estimation techniques such as adaptive neuro-fuzzy inference systems (ANFIS) and artificial neural networks (ANN) which offer nonlinear input–output mapping. In this paper, the supervised learning methods of ANFIS and ANN are exploited for estimating the experimentally determined HTC. This original research fulfills the preceding modeling efforts on thermal properties of EGWM and HTC applications in the literature. An experimental test setup is designed to compute HTC of mixture over a small circular aluminum heater surface, 9.5 mm in diameter, placed at the bottom 40-mm-wide wall of a rectangular channel 3 mm × 40 mm in cross section. Measurement data are utilized as the train and test data sets of the estimation process. Prediction results have shown that ANFIS provide more accurate and reliable approximations compared to ANN. ANFIS present correlation factor of 98.81 %, whereas ANN estimate 87.83 % accuracy for test samples.     

Soy versus whey protein bars: Effects on exercise training impact on lean body mass and antioxidant status

Background

Although soy protein may have many health benefits derived from its associated antioxidants, many male exercisers avoid soy protein. This is due partly to a popular, but untested notion that in males, soy is inferior to whey in promoting muscle weight gain. This study provided a direct comparison between a soy product and a whey product.

Methods

Lean body mass gain was examined in males from a university weight training class given daily servings of micronutrient-fortified protein bars containing soy or whey protein (33 g protein/day, 9 weeks, n = 9 for each protein treatment group). Training used workouts with fairly low repetition numbers per set. A control group from the class (N = 9) did the training, but did not consume either type protein bar.

Results

Both the soy and whey treatment groups showed a gain in lean body mass, but the training-only group did not. The whey and training only groups, but not the soy group, showed a potentially deleterious post-training effect on two antioxidant-related related parameters.

Conclusions

Soy and whey protein bar products both promoted exercise training-induced lean body mass gain, but the soy had the added benefit of preserving two aspects of antioxidant function.

     

SignTutor: An Interactive System for Sign Language Tutoring

Language learning can only advance with practice and corrective feedback. The interactive system, SignTutor, evaluates users' signing and gives multimodal feedback to help improve signing.     

A modelling and optimization system for fluidized bed power plants

The energy production has nowadays several challenges. For example, new environmental legislation sets needs to reduce process emissions. However, emission reduction may also be a part of business in power plants arose from emission trading schemes, like The European Union Emissions Trading Scheme. In this paper we demonstrate an optimization and modelling system for fluidized bed power plants, which can be used in this new service business. The software contains four parts: (1) pre-processing, (2) variable selection and process lags, (3) modelling and (4) post-processing. In the post-processing part there are three applications, i.e. process state determination, process optimization and emission reporting. The modelling part is based on the self-organizing maps (SOM) with retrain properties. The software is programmed into standalone software built up in the Matlab platform. The results show that the software can offer an efficient tool to process optimization and also to a new type of service business.     

IGBT驱动模块的用法改进

指出了ＥＸＢ８４１应用中存在的问题，给出了改进方法，并成功应用于工程实践     

变网格间距速度层析成像方法

变网格间距速度层析成像,是指反演网格模型中采用不同的网格间距反演地下地层的速度分布,它可以在观测数据较少的情况下,提高浅部地层速度反演的分辨率和深层速度反演的精度。变网格间距与规则网格间距速度层析成像方法类似,但有两个最主要的不同之处:射线正演网格单元的射线段被划分到相应的较大反演网格单元中,平滑约束方程在变网格间距界面的上-平面和下-平面的网格处需要做出适当的修改。文中首先采用变网格方法对二维和三维检测板模型进行恢复测试,反演结果对大、小异常体的刻画效果均比规则网格方法好;然后,采用变网格方法对实际资料进行走时反演,反演结果对两个低速异常区的刻画比规则网格方法的效果好。因此,变网格方法反演的速度剖面分辨率较高,尤其对浅部地层的速度成像效果具有较大的改善作用;另外,在观测数据较少的情况下,通过调整不同网格的数量比例,变网格反演方法还可以克服层析成像过程中解的欠定问题。     

Wind power in China: Policy and development challenges

The capacity of the Chinese wind power sector has increased rapidly over the past half-decade, essentially doubling every year since 2005. The purpose of this paper is to describe the industry’s recent development and to discuss some of the policies and policy challenges related to the particular business environment in China. Three issues are highlighted: pricing policies, transmission capacity, and the structure of the equipment manufacturing industry, where substantial overcapacity is emerging as a serious problem.     

Reactor core design optimization of the 200 MWt Pb–Bi cooled fast reactor for hydrogen production

In this study reactor core geometrical optimization of 200 MWt Pb–Bi cooled long life fast reactor for hydrogen production has been conducted. The reactor life time is 20 years and the fuel type is UN-PuN. Geometrical core configurations considered in this study are balance, pancake and tall cylindrical cores. For the hydrogen production unit we adopt steam membrane reforming hydrogen gas production. The optimum operating temperature for the catalytic reaction is 540 °C. Fast reactor design optimization calculation was run by using FI-ITB-CHI software package. The design criteria were restricted by the multiplication factor that should be less than 1.002, the average outlet coolant temperature 550 °C and the maximum coolant outlet temperature less than 700 °C. By taking into account of the hydrogen production as well as corrosion resulting from Pb–Bi, the balance cylindrical geometrical core design with diameter and height of the active core of 157 cm each, the inlet coolant temperature of 350 °C and the coolant flow rate of 7000 kg/s were preferred as the best design parameters.