OBNOXIOUS FACILITY LOCATION IN THE INTERIOR OF A PLANAR NETWORK*

ABSTRACT. The problem of locating a point that is as far as possible from arcs and nodes of a network is investigated. Each arc or node may have a different multiplicative factor (weight) for its distance. A graphical solution approach, as well as a computational algorithm, is presented.     

Human and Natural Controls on the Accumulation,Acidification and Drainage of Pyritic Sediments: Pearl River Delta,China and Coastal New South Wales

There is increasing concern about environmental impacts of acidic drainage from acid sulphate soils on Holocene estuarine flood plains. Acidity derives from oxidation of iron pyrite in the sediments. Natural factors determine concentrations and distributions of pyrite accumulations, but human activities have reduced pyrite accumulation in the Pearl River Delta with land use practices increasing terrestrial sediment discharge. Large freshwater discharges and management techniques have enabled sustainable use of these soils. High concentrations of pyrite occur in many estuarine flood plains of Australia because of relatively greater marine inputs. Drainage of these soils enhances pyrite oxidation and estuarine acidification, which is associated with fish-kills. For sustainable development, the problems of acid sulphate soil drainage must be recognised and overcome.     

Book reviews

THE MIND OF EAST ASIA, Lily Abegg. (338 pp. with Index). Translated from the German. Thames and Hudson; London, New York.

BRITAIN AND THE UNITED STATES: Problems in Co‐operation. A joint report prepared by Henry L. Roberts and Paul A. Wilson. London. Royal Institute of International Affairs. Pp. 224. Price 8/6 sterling. 1953.

D?R LAUTLOSE AUFSTAND. BERICHT VEBER DIE WIDER‐STANDSBEWEGUNG DES DEUTSCHEN VOLKES 1933–1945. Herausgegeben von Guenther Weissenborn. Rowohlt Verlag Hamburg. Pp. 348.

“EASTERN AND WESTERN WORLD”: Selected Readings with a foreword by S. Hofstra. Issued under the auspices of the Netherlands Foundation for International Co‐operation and published by W. Van Hoeve Ltd., The Hague, Bandung. 1953. Pp. 181.

NATIONALISM AND SOCIAL COMMUNICATION. By Karl W. Deutsch. John Wiley & Sons, N. Y. viii and 292.

BURMA UNDER THE JAPANESE: By Thakin Nu. Pictures and Portraits, Edited and translated with Introduction by J. S. Furnivall. Macmillan, London. 1954. Pp. xxviii and 132. Price 12s 6d.

COMMODITY TRADE AND ECONOMIC DEVELOPMENT—Report of a Committee appointed by the Secretary‐General, United Nations, Published by the United Nations, 1953.     

AN ASSESSMENT OF BACK-SCATTERED ELECTRON PETROGRAPHY AS A METHOD FOR DISTINGUISHING MEDITERRANEAN OBSIDIANS

The recent application by Burton and Krinsley (1987) of back-scattered electron (BSE) petrography to obsidians from sources located in the south-western United States established that this method can effectively resolve and characterize included micro-crystalline phases that have proven difficult to analyse by optical thin-section microscopy. In the first extension of their original study, we have examined, using BSE petrography, obsidians from island sources located in the Mediterranean, including sources known to have been exploited in prehistory. Because of the kinetic contrasts on their crystallization, these microcrystalline phases reflect the magmatic history of the obsidian, providing information about superheating, supercooling, sub-solidus processes, and other phenomena. This information is of significance for the chemical analysis of Mediterranean obsidians and also as the basis for a powerful alternative to existing non-destructive analytical methods for the sourcing of archaeological and art-historical obsidian.     

Sustainable transport planning and the Dublin transportation initiative

The concept of sustainability has become a significant consideration in planning in Europe and the US. At both the international and the national level, urban planners and policymakers have developed a package of policies designed to produce sustainable growth and development. In transport, this has been interpreted to mean that we need to increase accessibility while we reduce mobility by shifting trips from automobile to walking, bicycle or public transport modes. Using this criteria, the latest Dublin transport plan has been found to be only partially effective. Similar to many American transport plans, the DTI has opted for the infrastructure‐related sustainability policies and avoided the less popular economic disincentives.