A generalized fault location method based on voltage sags for distribution network

An enhanced fault location method based on voltage sag profiles for distribution networks is presented in this paper. In other previous methods, only a single measurement has been used. The proposed method can be used with any number of measurements in the network, making it more general. A new ranking approach that addresses multiple possibilities of the faulted section is proposed. Different case studies with various numbers of measurements are performed on a large 11‐kV network with the main feeder consisting of 42 buses to validate the method. The test results show that there is an improvement in terms of accuracy in detecting the faulted section in the first attempt for each additional measurement. Therefore, by utilizing the average value of each measurement, a better accuracy of fault location can be achieved. © 2013 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Economic load dispatch with nonsmooth cost functions using evolutionary particle swarm optimization

This paper presents an evolutionary particle swarm optimization (EPSO) method for solving the nonconvex economic load dispatch (ELD) problem. In practice, the nonconvex and the discontinuous cost function should be considered when optimizing ELD problem with constraints such as valve point effects, prohibited operating zones, ramp‐rate limits, and transmission loss of the system. In view of these constraints, the ELD problem is difficult to solve by any mathematical method. In EPSO, the evolutionary programming concept (combination, tournament competition, sorting, and selection) is employed in the classical PSO method in order to find the best individual and best group position based on the survival particle. The effectiveness of the EPSO is tested on 3‐, 6‐, 15‐, and 38‐unit systems. The results obtained by EPSO are also compared with classical PSO and other results reported in the literature. It is concluded that the EPSO method can produce lower generation cost compared to the existing methods. © 2013 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

A review on islanding operation and control for distribution network connected with small hydro power plant

Hydro power generation is the oldest generation and provides the largest contribution among the renewable energy types of generation. In distribution system, most of the distributed generation (DG) is small scale hydro generation of which utilizes the natural flowing water of the river. This generation requires governor and excitation control unit to control and sustain the power generation when subjected to any changes of load behavior. More advanced control strategy is critically expected when considering the recent interest in distribution system to perform islanding operation of DG. Many of the literature have clearly highlighted this issue, but only a few have discussed on the islanding operation of small hydro generation. This paper therefore reviews this topic and relates the discussion with the controller designed for other type of turbines interfaced with synchronous generator. To strengthen the knowledge on islanding operation, the background of islanding is also presented in this paper.     

Current state of science and technology in the Muslim world

Reviews the current state of science and technology in the Muslim world in the light of the CASTASIA 1968 and the International Conference on Science in Islamic Polity 1983 recommendations of allocating 1.0 percent of GNP for R&D. The data presented indicates that the Muslim countries have not been able to achieve this target. OIC countries on the average spend 0.45 percent of their GNP on R&D as compared to 2.30 percent by OECD countries. Egypt which leads the Muslim countries spends 0.86 percent of its GNP on R&D as compared to 2.27 percent by Israel. Indonesia spends 0.17 percent as compared to 1.78 percent by Taiwan. Annual growth of R&D expenditure in a few Muslim countries, especially Turkey and Malaysia, is very encouraging. Muslims are also far behind in terms of R&D manpower. OIC countries have 8.5 scientists, engineers and technicians per 1,000 population as compared to 40.7 of world average and 139.3 for OECD countries. The contribution of Muslim countries to world science literature is also meagre. Forty-six Muslim countries contribute 1.17 percent to world science literature as compared to 1.66 percent by India and 1.48 percent by Spain. Twenty Arab countries contribute 0.55 percent as compared to 0.89 percent by Israel alone. Contribution to science literature is also analyzed on the basis of total population, literate population, and GNP per capita. Growth of science literature in many Muslim countries is faster than OECD countries.     

Changes in polyphenol ability to produce astringency during roasting of cocoa liquor

Polyphenols in cocoa products determine the astringent sensation due to their interaction with salivary proline‐rich protein. Changes in the ability of polyphenols to produce astringency during cocoa roasting have been studied through an evaluation of the polyphenol–protein interaction in cocoa cake/liquor roasted at 120 °C for 45 min, with and without enrichment with polyphenol extract. Roasting decreased the capacity of polyphenols to interact with protein, causing a decrease in astringency. However, the polyphenol–protein interaction products after roasting could still be oxidized enzymatically and most probably would still give cocoa products beneficial effects as functional food. Copyright © 2005 Society of Chemical Industry     

High‐impedance fault location using matching technique and wavelet transform for underground cable distribution network

Locating the faulty section of a high‐impedance fault (HIF) is quite challenging for the underground distribution network of a power system. The complexity of the distribution network, such as branches, nonhomogenous lines, and HIF, contributes to the difficulties in locating the faulty section. In this paper, the shortest distance (SD) technique and a database approach have been proposed to determine the faulty section. A multiresolution analysis based on discrete wavelet transforms is chosen to extract the unique features from voltage signals during the HIF event. The output coefficients from the decomposition process is stored in a database and used as the input data for the SD algorithm. The first, second, and third level of detailed coefficients of the post‐disturbance voltage signal were utilized for the identification of the faulty section using the proposed method. A ranking analysis was created to provide a number of possibilities of faulty section. In this paper, a 38‐node underground distribution network system in a national grid in Malaysia was modeled using the PSCAD software. The proposed method was able to successfully determine the faulty section. © 2013 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Chemical and taste characteristics of threadfin bream (Nemipterus japonicus) hydrolysate

The chemical and taste characteristics of threadfin bream (Nemipterus japonicus) hydrolysate produced by Alcalase hydrolysis of the fish muscle (pH 8.5, 60 °C, 120 min, enzyme/substrate ratio 20 g kg^?1) were studied. Umami, bitter and fishy were the dominant tastes. The bitter amino acids methionine, valine, isoleucine, phenylalanine, leucine and tyrosine comprised 317 mg g^?1 of the total amino acids present. The umaminess could be due to the presence of high contents of glutamic acid and inosine 5′‐monophosphate. SDS‐PAGE analysis showed that the peptides in the hydrolysate had molecular weights ranging between 7.2 and 64 kDa. Copyright © 2004 Society of Chemical Industry     

Effect of different fiber loadings and sizes on pultruded kenaf fiber reinforced unsaturated polyester composites

Application of the available natural resources became crucial for developing sustainability recently. The use of natural fiber as reinforced materials in polymer composite materials is gaining new interest from within industry. In this research, the effect of different fiber loadings and different types of kenaf yarns, used on the properties of Pultruded Kenaf Fiber Reinforced Composites (PKFRC), was studied. The pultruded composite samples were prepared with different fiber loadings and sizes (tex) of kenaf fiber. Three different fiber loadings, i.e., 60, 65, and 70% were used during the preparation of the PKFRC samples. Flexural and compression testing was performed, to study the effect of different fiber loadings and different kenaf fiber yarns, on the mechanical properties of kenaf fiber pultruded composites. The results show that the highest fiber loading of 70% gave more desirable flexural and compression properties to the PKFRC. The use of twist kenaf yarn fiber showed lower mechanical properties of PKFRC as compared to the single kenaf yarn. Damage configurations and accumulations for each loading case were examined. A morphological study, using optical microscopy (OM) revealed the type of fracture that occurred in the pultruded samples after mechanical testing. POLYM. COMPOS., 36:1224–1229, 2015. © 2014 Society of Plastics Engineers