Stand alone intelligent digital distance relay

Remote end infeed causes problems in distance relay especially under high resistance earth fault conditions. Although a distance relay set to an ideal operating region can cover the fault resistance at one particular load condition, the operating region is affected by changes in load condition. Hence a distance relay may overreach or underreach when load changes. From the main factors which affect the ideal digital distance relay operating region, a stand alone intelligent digital distance relay which can adapt to these changes is presented. This approach does not need communication links from the remote end of the line or the system control center. Numerous computer simulations have been carried out on realistic system configurations and the results show that there is a high potential for developing an intelligent digital distance relay     

In vitro study of the interaction between pectinase and chelate-soluble pectin in postharvest apricot fruits

Firmness is one of the most important quality attributes of apricot fruits and is associated with chelate-soluble pectin (CSP). To elucidate the changes in CSP during postharvest, in vitro investigation of pectinase effects on CSP of apricot fruits was applied to simulate the in vivo changes in CSP fraction during postharvest. It was found that effects of pectinase (40 U/mg) treatment were similar to those of storage time on CSP nanostructures from the results of atomic force microscopy. Relative frequency of widths less than 31.25 nm was 3.6 % for control group, while it was 16.2, 52.0 and 65.5 %, respectively, for 1:10,000 (pectinase/CSP), 1:1,000 and 1:100 pectinase-treated groups. Most of the CSP lengths were 0.5–1 μm, while it was 0–1 μm for pectinase-treated groups. Pectinase treatment had some similar effects on CSP fraction as storage time.     

脱硫除尘岛钢支架结构形式分析

钢支架是脱硫除尘岛重要的支撑结构,其设计是否合理,直接影响脱硫除尘岛的安全性、经济性和美观性。从钢支架结构体系、构件形式、节点形式3个方面,结合脱硫除尘岛的特点和我国材料供应、加工水平、安装能力等现状进行分析,提出了适合脱硫除尘岛特点的钢支架各种形式,以保证脱硫除尘岛钢支架安全可靠、节约钢材、构造简单和施工方便。     

A quasi-two-dimensional electrochemistry modeling tool for planar solid oxide fuel cell stacks

A quasi-two-dimensional numerical model is presented for the efficient computation of the steady-state current density, species concentration, and temperature distributions in planar solid oxide fuel cell stacks. The model reduction techniques, engineering approximations, and numerical procedures used to simulate the stack physics while maintaining adequate computational speed are discussed. The results of the model for benchmark cases with and without on-cell methane reformation are presented with comparisons to results from other research described in the literature. Simulations results for a multi-cell stack have also been demonstrated to show capability of the model on simulating cell to cell variation. The capabilities, performance, and scalability of the model for the study of large multi-cell stacks are then demonstrated.     

A genetic algorithm based heuristic for adjacent paper-reel layout problem

In this paper, we present an algorithm that solves a paper reel layout problem where the available space is divided into equal-size cells. The problem is to find a layout with the minimum transportation cost subject to adjacency and other constraints. A genetic algorithm is used in a two-stage iterative approach to solve the problem. Computational results seem to indicate the efficiency and effectiveness of the proposed solution method.     

Synthesis and Bacterial Mutagenicity of Oxidized Derivatives of-Polycyclic Aromatic Hydrocarbons

A series of oxidized derivatives of nitrophenanthrene and nitrobenz[a]anthracene were synthesized and their mutagenicities in Salmonella typhimurium TA98, TA98NR, TA98/1,8-DNP₆, TA100, and TA100NR were determined. These compounds exhibited markedly different mutagenicities. Orientation of the nitro group is an important structural feature for correlation with mutagenic potency.     

渤海海域天然气勘探前景

渤海海域油气勘探已进行了30多年，在天然气勘探方面，仅仅找到一些中、小型天然气田（藏），在综合分析盆地类型，天然气成因和富气凹陷形成条件的基础上，认为渤海海域是一个相对以油为主的油气区，天然气以油型气和陆源有机气为主，天然气藏可能以中、小型为主，由于目前天然气资源量探明度低，因此渤海海域仍具有一定的天然气勘探前景。