University of Malaya

About: University of Malaya is a education organization based out in Kuala Lumpur, Malaysia. It is known for research contribution in the topics: Population & Fiber laser. The organization has 25087 authors who have published 51491 publications receiving 1036791 citations. The organization is also known as: UM & Universiti Malaya.

LXCat : an open-access, web-based platform for data needed for modeling low temperature plasmas

Abstract: LXCat is an open-access platform (www.lxcat.net) for curating data needed for modeling the electron and ion components of technological plasmas. The data types presently supported on LXCat are scattering cross sections and swarm/transport parameters, ion-neutral interaction potentials, and optical oscillator strengths. Twenty-four databases contributed by different groups around the world can be accessed on LXCat. New contributors are welcome; the database contributors retain ownership and are responsible for the contents and maintenance of the individual databases. This article summarizes the present status of the project.

Performance and emission assessment of diesel-biodiesel-ethanol/bioethanol blend as a fuel in diesel engines: a review.

Abstract: The aim of this review is to study the opportunities and prospects of introducing diesel–biodiesel–ethanol/bioethanol blend as fuel in the existing diesel engines. The study is based on the engine emissions and its performance. The energy policies and the ever growing energy demand of the world, require an alternative to fossil fuels. In this quest, the diesel–ethanol blend or the diesohol blend might be a good option. But this blend possesses stability problem as well as inferior physicochemical properties when compared to diesel fuel and needs additives to remain stable. When biodiesel is used as an additive in this diesohol blend, it improves the physicochemical properties of the ternary blend, engine performance and also increases the renewable portion of the blend. First the engine performance and emissions data found by using diesel–biodiesel–ethanol/bioethanol ternary blends are accumulated. Then the results of the scientists and investigators are discussed to evaluate its potential as an alternative to fossil diesel fuel. The physicochemical properties of ternary blends are found to be almost similar to the diesel fuel. These ternary blends significantly reduce the PM (particulate matter) emissions from the diesel engine but the emissions of NO x (nitrogen oxides), soot and smoke, HC (hydrocarbon), CO (carbon monoxide), CO 2 (carbon dioxide) and the carbonyl compounds depend on the operating conditions of the engine and remain almost similar to the diesel fuel exhaust.

Overview of citric acid production from Aspergillus niger

Abstract: Citric acid has high economic potential owing to its numerous applications. It is mostly produced by microbial fermentation using Aspergillus niger. In view of surges in demand and growing markets, there is always a need for the discovery and development of better production techniques and solutions to improve production yields and the efficiency of product recovery. To support the enormous scale of production, it is necessary and important for the production process to be environmentally friendly by utilizing readily available and inexpensive agro-industrial waste products, while maintaining high production yields. This article reviews the biochemistry of citric acid formation, choices of citric-acid producing microorganisms and raw materials, fermentation strategies, the effects of various fermentation conditions, citric acid recovery options and the numerous applications of citric acid, based on information drawn from the literature over the past 10 years.

Defining the Rural-Urban Fringe

Abstract: This study is concerned with the rural-urban fringe as a complex transition zone on the periphery of growing urban areas in Western countries. Case studies of the fringe and related areas are reviewed, and a definition of the rural-urban fringe is suggested. Further, the urban fringe is differentiated from the rural fringe, the former constituting the subzone of most rapid exurban invasion. Hypotheses are postulated regarding the residents, accessibility, and land and dwellings in the fringe, and suggestions for future studies are outlined in the conclusion. T L. Smith's discussion of the "urbanl fringe" around Louisiana in 1937 marked the first use of this term signifying "the built-up area just outside the corporate limits of the city."' As a landscape phenomenon, the fringe varies from city to city, and from one time to another. Around several cities in the Netherlands a fringe is barely recognizable; Paris is somewhat similar to the U.S.A. in the intermingling and scatter of land use, but there is a closer dependence on public transport; London is different again, because of its Green Belt, * The financial assistance and research supervision provided in the Department of Geography, University of Melbourne, are gratefully acknowledged by the author. 1 T. L. Smith, "The Population of Louisiana: Its Composition and Changes," Loulisiana Butlletini, 293 (November 1937). This content downloaded from 157.55.39.10 on Mon, 08 Aug 2016 05:31:49 UTC All use subject to http://about.jstor.org/terms THE RURAL-URBAN FRINGE 203 although there is some scattering of land use, and some villages are located within this belt. In general, Dickinson concludes that the modern European city "exhibits the same tendency to extend and explode" as the North American metropolis, "but not nearly to the same degree."2 Conversely, some American writers now question whether the urban fringe problern is disappearing, because "laws permit more cities to supervise zoning within a certain distance of their borders."3 Two features characterize the literature on urban fringe over the past 30 years: 1. The general absence of explicit references to the subject outside North America, although there have been studies, for example, in Sydney,4 Adelaide,5 Melbourne,6 and in London7 and Johannesburg.8 The relatively integral urban nature (rather than nonoccurrence) of the fringe around European cities emerges from Wissink's comparison of that continent with the American urban scene.9 2. The confusion of terminiology and lack of clear delineation in case studies. The problem of evaluating and comparing cases is increased by (1) their range in time, as prevailing economic conditions influence the rate of growth and internal characteristics of the fringe; (2) the range in size of the urban center, from a small village to a metropolis or Standard Metropolitan Statistical Area, each with inherent differences in its fringe, according to the rate of growth, functions, and hierarchical relationship of the central place; (3) the variation in type and degree of zoning control of urban invasion beyond a city's corporate limits, so that London's modified Green Belt results in a very different form of guided "overspill" to Eugene-Springfield's "uncontrolled population expansion" ;10 (4) the differing social, economic and political contexts of the studies from different countries; ancd (5) the differing aims and interests of various research \vorkers. A REVIEW OF RELATED TERMS Because of this diversity, a number of attempts have been made to clarify concepts, and to differentiate between commonly used terms. After reviewing some ten definitions, Kurtz and Eicher1 differentiate between "fringe" and "suburb"; Wissink12 defines 'fringe," "suburbs," "pseudo-suburbs," "satellites" and "pseudo-satellites"; Schnore13 distinguishes between "satellites" and "suburbs"; and a number of writers have described different types of suburbs, some of which could be synonomous with the "fringe" of anotlher research worker. Martin discusses satellite rural areas.14 Areal differentiations have also been made, clualitatively, within the fringe: the "urban 2 R. E. Dickinson, The City Region in Western Etrope (London: Routledge Paperback, 1967). 3 E.g., R. E. Murphy, The Amterican City: An Urban Geography (New York: McGraw-Hill Book Co., 1966). 4 N. R. Wills, "The Rural-Urban Fringe: Some Agricultural Characteristics with Specific Reference to Sydney," Australian Geographer, 5 (1945), pp. 29-35; and R. Golledge, "Sydney's Metropolitan Fringe: A Study in Urban-Rural Relations," Australian Geographer, 7 (1959), p. 243 ff. 5 D. L. Smith, "Market Gardening at Adelaide's Urban Fringe," Economtic Geography, 42 (1966), p. 19 ff. 6 R. J. Johnston, "The Population Characteristics of the Urban Fringe: A Review and Example," Atustralian and New Zealand Journal of Sociology, 2 (1966), pp. 79-93. 7 R. E. Pahl, Urbs in Rure: The Mlfetropolitan Frintge in Hertfordshire (London: London School of Economics and Political Science, Geographical Papers No. 2, 1965). 8 G. H. T. Hart and T. C. Partridge, "Factors in the Development of the Urban Fringe North-West of Johannesburg," South African Geographical Journal, 48 (1966), pp. 32-44. 9 G. A. Wissink, Anmerican Cities in Perspective: With Special Reference to the Development of Their Fringe Areas, Sociaal Geografische Studies, Hoogleraar aan de Rijksuniversiteit te Utrecht, Nr. 5 (Assen, Netherlands: Royal Van Gorcum, 1962). 10 W. T. Martin, The Rural-Urban Fringe: A Study of Adjustmnent to Residence Location (Eugene: University of Oregon Studies in Sociology, No. 1, 1953). 11 R. A. Kurtz and J. B. Eicher, "Fringe and Suburbs: A Confusion of Concepts," Social Forces, 37 (October 1958), pp. 32-37. 12Wissink, op. cit. 13 Leo F. Schnore, "Satellites and Suburbs," Social Forces, 36 (December 1957), pp. 121-127. 14 W. T. Martin, "Ecological Change in Satellite Rural Areas," American Sociological Reviezo, 22 (April 1957), pp. 173-183. This content downloaded from 157.55.39.10 on Mon, 08 Aug 2016 05:31:49 UTC All use subject to http://about.jstor.org/terms