On-site Radioscopic Qualitative Assessment of Historic Timber Structures: Identification and Mapping of Biological Deterioration of Wood

The recent development of portable, battery-charged x-ray tubes and digital detectors has made digital radioscopic examination of wooden buildings a realistic option. Lack of experience with the often very complex radiographs of building structures makes the interpretation of such radiographs difficult. A set of radiographs of wood in different, identified conditions was established for use when interpreting radiographs of wood in unknown condition.

This article presents radiographs of a trestle-framed building. The recordings were done in areas where the condition of the wooden elements was known in advance, either on the basis of dendrochronological drill samples or because the building element had been replaced recently and the wood was sound. The radiographs were compared with NIKU´s collected guideline radiographs and discussed with respect to the information they provide about the wood’s condition. Finally, we discuss radioscopy as a supplement to traditional methods of building surveying.

The authors took all of the photos and radiographs (©NIKU). The radiographs are shown as “shadow” images—materials of higher density are seen lighter than materials of less density, as long as they are of same thickness.     

HOW WE LIVE WITH THE PAST NOW

Michael Roth's new collection of essays, written over the last two decades, is held together by its author's pervasive concern with human temporality: our individual and collective passages through time, recorded by the faculty of memory, which pose some of our most intractable problems. The essays treat, and indeed provide a map to, several adjacent areas of inquiry: the history of the psychopathology of memory in the long nineteenth century; the vicissitudes of the trauma‐concept from its relatively modest medical origins to its postmodern apotheosis; and photography as a medium and art form embroiled in our relationship with the past. Roth's major interventions are threefold. First, while persuaded of the value of the psychoanalytic version of the trauma‐concept, he critiques the so‐called traumatophilia of postmodern theorists who, usually with reference to the Holocaust, seek to invest trauma with ethical valences and powers of legitimation or even, as in the case of Agamben, raise it to ontological status. Second, through his fine‐grained account of Freud's convergence with and divergence from his French colleagues, especially Charcot and Janet, Roth argues that the stunning breakthrough of psychoanalysis was to take the past seriously, to recognize the inevitable penetration of the past into the present in the human psyche as well our affective investment in and need to narrativize the past. For Roth, Freud's continued relevance today resides in what he has taught us about living with the past. Finally, Roth begins to develop the concept of “piety” as an attitude toward the past that fuels the writing of history. He leaves the concept in rudimentary form, but his evocative remarks suggest the fruitfulness of developing it further.     

On the Earliest Attestable Forms of the Pravargya Ritual: Rg-Vedic references to the Gharma-Pravargya,Especially in the Atri-family Book (Book 5)

Indo-Iranian Journal -     

Land Markets in the Harris-Todaro Model: A New Factor Equilibrating Rural-Urban Migration

Recent research in the Harris-Todaro (HT) tradition has added an important new element to the model by incorporating an urban land market. Brueckner and Zenou (1999) (hereafter BZ) argue that a model where migration equalizes expected wages between city and countryside may overlook another important force that equilibrates the process of rural-urban migration. This force is the migration-induced rise in the urban cost of living, which occurs principally through escalation of urban land rents as the city population expands. Land-rent escalation, which tends to limit rural-urban migration, provides an important additional force that may help determine city sizes in developing countries. The present paper provides a simpler alternative to BZ's analysis by assuming that urban residents smooth their income as they cycle between formal and informal employment. This allows migration decisions to be based on the expected wage, as in the usual HT framework, in a model that includes a land market. The analysis shows that this modified framework generates results slightly different from those of BZ.     

Die Berechnung von Wasserfluten. Tideforschung in den Niederlanden, 1920–1960

In the first half of this century a computing problem became evident in the course of preparatory research for major hydraulic projects in the Netherlands. One of the most novel problems was to predict the changes in the tidal movements caused by hydraulic works in coastal waters. Between 1920 and 1960 several solutions were proposed and put into practice: numerical methods, contracting young men for the calculations, analogue electronical networks and large scale models. The amount of computing labour played a decisive part in the choice between these methods. After a storm surge in 1953 causing estensive inundations in the southern part of The Netherlands, the requirements of the Delta Works project gave an enormous impetus to all three types of methods.