Research on Web-Based Product Structure and Configuration Management

An enhanced system architecture of Web-based product structure and configuration management system along with its, functions are is presented. The key techniques, such as construction of object models of product structure and product configuration, hybrid approach method in product configuration management, sharing and integration of heterogeneous product data, integration with other sub-systems, are discussed too. A prototype system is developed by J2EE technology.

Performance Investigation of Hybrid and Conventional PV Array Configurations for Grid-connected/Standalone PV Systems

Currently,the critical challenge in solar photovoltaic(PV)systems is to make them energy efficient.One of the key factors that can reduce the PV system power output is partial shading conditions(PSCs).The reduction in power output not only depends on a shaded region but also depends on the pattern of shading and physical position of shaded modules in the array.Due to PSCs,mismatch losses are induced between the shaded modules which can cause several peaks in the output power-voltage(P-V)characteristics.The series-parallel(SP),total-cross-tied(TCT),bridge-link(BL),honey-comb(HC),and triple-tied(TT)configurations are considered as conventional configurations,which are severely affected by PSCs and generate more mismatch power losses along with a greater number of local peaks.To reduce the effect of PSCs,hybrid PV array configurations,such as series-parallel:total-cross-tied(SP-TCT),bridge-link:total-cross-tied(BL-TCT),honey-comb:total-cross-tied(HC-TCT)and bridge-link:honey-comb(BL-HC)are proposed.This paper briefly discusses the modeling,simulation and performance evaluation of hybrid and conventional 7×7 PV array configurations during different PSCs in a Matlab/Simulink environment.The performance of hybrid and conventional PV configurations are evaluated and compared in terms of global maximum power(GMP),voltage and currents at GMP,open and short circuit voltage and currents,mismatch power loss(MPL),fill factor,efficiency,and a number of local maximum power peaks(LMPPs).

Preliminary Study on γ-Aminobutyric Acid (GABA_A) Like Receptor in Rat Testis

For making it clear whether GABAA-like receptor is in cells or rat testis and how itsgene expresses in tissue cells, the mRNA of rat testis was microinjected into Xenopusoocyte. The membrane electrobiological results showed that an inward 30 nA micro-currentwas elicited, under two-electrode voltageclamped configuration, by extracellular GABA(500 μmol/L), and both Bicuculline and Picrotoxin could inhibit this effect. It is an indication that the mRNA of rat testis can express GABA receptor in the membrane of Xenonpus oocyte. Using Muscimol as a excitant of GABA receptor type A, the micro--currentwas also elicited to generate; however, using Baclofen as a excitant of GABA receptortype B, the micro-current could not be induced. These results indicate that GABA receptorexpressed in Xenopus oocyte membrane is not type B but for type A. On the basis of the research result above, 24-mer oligonucleotides to be complementary to the high conservativeregion of the cDNAs of neur-GABA receptors were synthesized as probes to hybridize respectively with the RNAs Of brain and testis of adult rat, and of rat testes of the variousages. The dot hybridizations showed that the hybrid signal of rat testis was stronger thanthat of rat brain, meaning that, compared with rat brain, the RNA of rat testis has morehomologous regions with probes, and also implying that the GABA receptor from theRNA Of rat testis may be similar to neural-GABA receptor. This receptor therefore iscalled as GABA_A-like receptor. The dot blot analysis above also showed the testis GABA_Alike receptor. The dot blot analysis above also showed testis GABA_A like receptor mRNAcontent changed with the develOPmental age of rats. There is a very low level of gene expression in the rat testis on day 5 postnatal; there is the highest expression of GABA_A-likereceptor gene in rat testes on day 30to 100 after birth; the expression begins to drop on day200 after birth.

Numerical Analysis on Charging Performance of the Macro-Encapsulating Combined Sensible-Latent Heat Storage System with Structural Parameters

For combined sensible-latent heat storage system(CSLHS)(termed as the hybrid configuration),macro encapsulation can effectively solve the leakage problem of PCMs.However,due to the poor thermal conductivity of PCMs,the charging performance of the hybrid configuration slightly increases compared to the solid structure(with only sensible materials).Meanwhile,the natural convection in the PCMs zone could improve the charging performance.So,how to improve natural convection intensity is a key issue for the CSLHS by macro encapsulating.It is found that adding fins can significantly enhance natural convection and accelerate the melting of PCM.In this paper,we proposed the hybrid configuration with fins built-in by macro encapsulation,and analyzed its charging performance with different fin structural parameters in the PCM zone by CFD simulation.In the case,the sensible heat storage material is high-temperature concrete and the PCM is a low-melting-point mixed molten salt.We analyzed the effects of fin number,fin length and fin thickness on the charging performance of the hybrid configuration respectively.From the result,the charging performance increases with the fin number,but the increase rate gradually decreases.When the fin number is 6,the charging performance increases by 20.18%compared to the situation without fin.The charging performance increases gradually with the fin length.Compared with the hybrid configuration without fin,for each 10 mm increase in fin length,its charging performances increase by 4.09%,5.26%,7.02%,8.77%,11.70%,and 15.79%,respectively.Different from number and length of fins,the effect of thickness on the charging performance is very small.When the fin thickness increased from 1 mm to 4 mm,the charging performance only increased by 2.3%.It indicates that the main reason for the improving the charging performance is to increase the natural convection intensity by dividing the PCM zone through fins.These results show that the charging performance of the CSLHS with macro encapsulation can be improved by optimizing fin structural parameters.

Numerical Simulation of Charging Performance of Combined Sensible-Latent Heat Storage System with a Macro-Encapsulation Method

In recent years,heat storage system combining sensible and latent heat materials has received more and more attentions.In this paper,we proposed the hybrid configuration with a macro-encapsulation,and analyzed its charging performance with different influencing factors by CFD simulation.In the case,the sensible heat storage materials are magnesia brick or HT concrete and the phase change materials(PCMs)are mixed molten salts.Firstly,we analyzed the heat transfer characteristics of the hybrid configuration in charging process.Then,we analyzed the effect of heating power on charging performance.The maximum temperature of the heating surface shall not exceed 500℃as the constraint condition,the heat storage capacity increases at first and then decreases with the heating power.Then,we compared the charging performance of different solid structure and the hybrid configurations.Whether magnesia brick or HT concrete,the charging performance of the solid structure is better than that of the hybrid configuration,because the thermal conductivity of the molten salt is significantly lower than that of the two sensible heat storage materials.Then,we compared the charging performance of different molten salts.The hybrid configuration with lower melting point molten salt has better performance because of more intensity natural convection.Finally,we analyzed the charging performance of the hybrid configuration used the composite phase change material(CPCM)with high thermal conductivity and specific heat.From the result,the charging performance increases by 22.5%compared with the solid structure.These results indicate that the hybrid configuration with the macro-encapsulation method is a potential form of thermal energy storage,but it needs to be further optimized.