A Decomposition Approach to Preventive Planning of Reactive Volt Ampere (VAR) Source Expansion

This paper presents a two-level approach for determining the minimum cost expansion pattern (location and size) of new reactive compensation sources that would ensure steady-state secure operation of large scale power systems not only under a given set of operating conditions for the intact system, but also under contingency conditions. This preventive planning problem is decomposed into a var dispatch (Level 1) problem and a var allocation (Level 2) problem which are related together using the generalized Benders decomposition. The methodology has been implemented in a prototype computer package which can handle power systems with up to 1500 buses. Results of testing the package with practical power systems of different sizes and characteristics are presented.     

Electroreduction of peroxycitric acid coexisting with hydrogen peroxide in aqueous solution

The electrochemical reduction of peroxycitric acid (PCA) coexisting with citric acid and hydrogen peroxide (H₂O₂) in the equilibrium mixture was extensively studied at a gold electrode in acetate buffer solutions containing 0.1 M Na₂SO₄ (pH 2.0-6.0) using cyclic and hydrodynamic voltammetric, and hydrodynamic chronocoulometric measurements. The reduction of PCA was characterized to be an irreversible, diffusion-controlled process, and the cyclic voltammetric reduction peak potential () was found to be more positive by ca. 1.0 V than that of the coexisting H₂O₂, e.g., the values obtained at 0.1 V s⁻¹ for PCA and H₂O₂ were 0.35 and −0.35 V, respectively, vs. Ag|AgCl|KCl (sat.) at pH 3.3. The of PCA was found to depend on pH, i.e., at pH > 4.5, the plot of vs. pH gave the slope (−64 mV decade⁻¹) which is close to the theoretical value (−59 mV decade⁻¹) for an electrode process involving the equal number of electron and proton in the rate-determining step, while at pH < 4.5, the was almost independent of pH. The relevant electrochemical parameters, Tafel slope, number of electrons, formal potential (E⁰′), cathodic transfer coefficient and standard heterogeneous rate constant (k⁰′) for the reduction of PCA and the diffusion coefficient of PCA were determined to be ca. 100 mV decade⁻¹, 2, 1.53 V (at pH 2.6), 0.29, 1.2 × 10⁻¹² cm s⁻¹ and 0.29 × 10⁻⁵ cm² s⁻¹, respectively, and except for E⁰′, the obtained values were almost independent of the solution pH. The overall mechanism of the reduction of PCA was discussed.     

Maximal load demand allocation

The authors address the problem of determining the maximum amount of active and reactive unserved load demand that can be connected to each bus in an electric power system without violation of its operating constraints. This maximal load demand allocation problem, which is associated with each electrical island of a power system operating in a restorative state, is formulated as a mixed nonlinear-integer programming problem. A decoupling procedure partitions the overall allocation problem into a maximal active load demand allocation subproblem and a minimal reactive load demand deallocation subproblem. The approach has been implemented in the form of a computer program and tested using power system models of up to 118 buses. Details of the implementation procedure and some illustrative test results are presented     

Functional characterization of a H+/nucleoside co-transporter (CaCNT) from Candida albicans,a fungal member of the concentrative nucleoside transporter (CNT) family of membrane proteins

Human and other mammalian concentrative (Na(+)-linked) nucleoside transport proteins belong to a membrane protein family (CNT, TC 2.A.41) that also includes Escherichia coli H(+)-dependent nucleoside transport protein NupC. Here, we report the cDNA cloning and functional characterization of a CNT family member from the pathogenic yeast Candida albicans. This 608 amino acid residue H(+)/nucleoside symporter, designated CaCNT, contains 13 predicted transmembrane domains (TMs), but lacks the exofacial, glycosylated carboxyl-terminus of its mammalian counterparts. When produced in Xenopus oocytes, CaCNT exhibited transport activity for adenosine, uridine, inosine and guanosine but not cytidine, thymidine or the nucleobase hypoxanthine. Apparent K(m) values were in the range 16-64 micro M, with V(max) : K(m) ratios of 0.58-1.31. CaCNT also accepted purine and uridine analogue nucleoside drugs as permeants, including cordycepin (3'-deoxyadenosine), a nucleoside analogue with anti-fungal activity. Electrophysiological measurements under voltage clamp conditions gave a H(+) to [(14)C]uridine coupling ratio of 1 : 1. CaCNT, obtained from logarithmically growing cells, is the first described cation-coupled nucleoside transporter in yeast, and the first member of the CNT family of proteins to be characterized from a unicellular eukaryotic organism.     

Studies on Indoor and Outdoor Radon/Thoron Concentration and Estimation of Radiological Parameters from Gamma Dose Rates along the Coastal Regions of Trivandrum and Kollam Districts,Kerala, India

Radiochemistry - The indoor and outdoor radon and thoron and γ-exposure rates were measured in different types of houses in selected locations along coastal regions of Trivandrum and Kollam...     

Mobile App Usage Pattern Prediction Using Hierarchical Flexi-Ensemble Clustering (HFEC) for Mobile Service Rating

Nowadays, the mobile app market becomes rapidly increased in world wide. The mobile app marketers have smart enough to understand the requirements and demands of customers and perform their aspirations. They delight them. It provides growth, profitability, and creativity with lot of inventions. The main aim of this research is to analyze the customer interest and preferences of mobile service providers. This paper proposed the clustering model named as Hierarchical Flexi-Ensemble Clustering. It provides the final result with robustness and improved quality. Before clustering, the unwanted features are removed by using the Genetic Algorithm based on the Collective Materials technique. The customer preferences are analyzes with the clustering of mobile usage patterns. The analysis determined that the app usage pattern based on the most frequent word, rating category, rating character count, rating word count and content-based rating in the google play store app dataset. Finally, the results are compared with the existing methods to analyze the superior performance of proposed method. The comparison analysis is estimated based on the based on the average hit rate at different cache sizes. The work is concluded with the app pattern prediction in the form of clustering for app marketing service. From the marketing side, they can analyze the customer preferences and satisfaction.

     

Investigation for possible source(s) of contamination of ready-to-eat meat products with Listeria spp. and other pathogens in a meat processing plant in Trinidad

In 2003, there was a recall of three processed (chicken franks, spice ham and turkey ham ready-to-eat (RTE) meat products by a large processing plant in Trinidad as a result of contamination by Listeria monocytogenes. The study was conducted to investigate the possible source(s) of Listeria contamination of recalled RTE meat products and to determine the prevalence of Listeria spp., Salmonella spp., Escherichia coli and Campylobacter spp. in the products and air within the plant. Raw and processed meat products, as well as food contact surfaces were also tested for Salmonella spp., Listeria spp. and Campylobacter spp. initially after thorough clean-up and close-down of the plant. Faecal and effluent samples from the piggery, in close proximity to the plant, were tested for the presence of Salmonella spp., Listeria spp. and Campylobacter spp. Air samples and food contact surfaces were negative for the tested organisms. Ten (58.8%) of the 17 effluent samples and 4 (11.8%) of the 34 faecal samples were positive for Campylobacter coli. Of the 11 raw meat products tested, 10 (90.9%) were positive for E. coli and Listeria spp. either singly or in combination. Of the 32 processed RTE products tested, 11 (34.4%) were positive for E. coli, Salmonella spp., Listeria spp. and Campylobacter spp. in combination or singly. Eleven (61.1%) of 18 processed products contained unacceptable levels of aerobic bacteria using international standards. Four months later, following the implementation of recommended cleaning, sanitizing and hygienic practices at the plant, pre- and post-processed products were sampled and Listeria spp. were identified in 4 (80.0%) of the 5 raw products and in 1 of the 5 (20.0%) finished products. Two (40.0%) of the finished products contained unacceptable microbial levels. It was concluded that the close proximity of the piggery to the processing plant was not the probable source of Listeria contamination of the recalled meat products. The data suggested that improved sanitary practices on food contact surfaces and during handling of products, reduced the risk of Listeria spp. and other pathogens studied. The problem at the plant can therefore, be inferred to be due to lapses in good sanitary practices, inadequate heat treatments or the presence of pathogens particularly Listeria in biofilms on different surfaces continuously or occasionally contaminating finished products.     

Examining the relation between domain-related communication and collaborative inquiry learning

Research suggests that providing others with elaborated explanations is more beneficial for learning than receiving explanations (e.g., Webb, 1989). Applied to chat communication in a collaborative inquiry learning environment, we would expect that in a dyad learners with more domain-related contributions than their partners would learn more. In the paper we develop a method to examine the relation between domain-related chats and learning outcome for intuitive knowledge. We describe how we automatically extract domain-related messages, and score them based on domain-orientedness. The analysis confirms that there is a positive relation between a high score on domain-related chats and the learning improvement as measured by the difference between a post-test and a pre-test on intuitive knowledge.