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Damage Assessment (damage + assessment)

Distribution by Scientific Domains

Engineering	40%

Selected Abstracts

COMPENSATORY RESTORATION IN A RANDOM UTILITY MODEL OF RECREATION DEMAND

CONTEMPORARY ECONOMIC POLICY, Issue 4 2010
GEORGE R. PARSONS
Natural Resource Damage Assessment cases often call for compensation in non-monetary or restoration equivalent terms. In this article, we present an approach that uses a conventional economic model, a travel cost random utility model of site choice, to determine compensatory restoration equivalents for hypothetical beach closures on the Gulf Coast of Texas. Our focus is on closures of beaches on the Padre Island National Seashore and compensation for day-trip users. We identify restoration projects that compensate for beach closures and that have good alignment in terms of compensating those who actually suffer from the closures. (JEL Q26) [source]

Untersuchung nichtlinearer Schwingungseigenschaften zur zerstörungsfreien Zustandsprüfung am Beispiel von Stahlbetonbalken

BETON- UND STAHLBETONBAU, Issue 9 2007
Markus Waltering Dipl.-Ing.
Ingenieurbauwerke, im Speziellen Straßen- und Bahnbrücken, sind ein unverzichtbarer Bestandteil der Infrastruktur eines Landes. Um eine möglichst lange und wirtschaftliche Nutzung dieser Bauwerke zu ermöglichen, werden an Brücken regelmäßige Inspektionen durchgeführt. Die herkömmliche und am weitesten verbreitete Methode der Zustandsanalyse ist die visuelle Prüfung durch erfahrene Ingenieure. Dabei können jedoch ausschließlich äußere Anzeichen einer Schädigung festgestellt werden. Je nach Bauwerksgröße kann eine entsprechende Prüfung Tage bis Wochen in Anspruch nehmen. In besonderen Fällen kommen sehr kosten- und zeitintensive Belastungsversuche zum Einsatz. Seit einigen Jahren kommen immer häufiger Methoden zur Anwendung, welche die dynamischen Eigenschaften zur Zustandsbewertung nutzen. Im Rahmen dieses Aufsatzes werden Versuche an Stahlbetonbalken vorgestellt, bei denen die Untersuchung nichtlinearen Schwingungsverhaltens im Vordergrund steht. Damit soll ein Beitrag für die mögliche und zukünftige Beurteilung des nichtlinearen Schwingungsverhaltens zur Zustandsbewertung im Rahmen von Brückeninspektionen geleistet werden. The Investigation of Nonlinear Dynamic Behaviour for Non-Destructive Damage Assessment of Reinforced Concrete Beams The detection of damages in civil engineering structures and bridges in particular is mainly done by visual examination. However, defects as for instance partial rupture of a prestressing cable or fatigue cracks in reinforcement can not be visually observed. It is well known that damage changes dynamic structural parameters like eigenfrequencies, eigenmodes and damping. However, the sensitivity to small damages is sometimes low. Therefore, as an alternative the occurrence and evaluation of non-linear dynamic behaviour is considered. The basic idea is that non-linear dynamic effects increase with growing cracks under forced excitation. The implementation of this idea in the regular inspection program of bridges presupposes exact knowledge of the eigenfrequencies of the undamaged structure that are also supposed to be force dependent. This paper presents the results of an experimental approach with three reinforced concrete beams of different damage states investigating the non-linear behaviour due to the excitation force. [source]

DNA damage assessment by comet assay of human lymphocytes exposed to jet propulsion fuels

ENVIRONMENTAL AND MOLECULAR MUTAGENESIS, Issue 1 2002
Shawna M. Jackman
Abstract Exposure to jet fuel damages DNA and results in a number of physiological changes in liver, lung, immune, and neurological tissue. In this study the single-cell gel electrophoresis assay or comet assay was used to compare the DNA damage in human peripheral lymphocytes produced by three jet propulsion fuels: JP-8, JP-5, and JP-8+100. These fuels consist of complex mixtures of aliphatic, aromatic, and substituted naphthalene hydrocarbons. Two exposure times were investigated which correspond to estimated occupational exposure times and concentrations of fuels were used that were based on previous fuel toxicity studies. Analysis of samples for the extent of DNA damage as determined by tail moment and percent tail DNA was performed on exposed cells following a brief recovery time. All fuels produced significant increases in DNA damage; however, only JP-8+100 was genotoxic at the lowest exposure concentration (1:500). At the highest exposure concentration (1:75), the mean tail moments for JP-8 and JP-8+100 (32.041 ± 2.599 and 45.774 ± 4.743, respectively) were significantly greater than for JP-5 (1.314 ± 0.474). These results indicate that JP-8+100 is the most potent inducer of DNA damage in human peripheral lymphocytes and that both JP-8+100 and JP-8 are capable of damaging lymphocyte DNA to a greater extent than JP-5. Environ. Mol. Mutagen. 40:18,23, 2002. © 2002 Wiley-Liss, Inc. [source]

Phase imaging using highly coherent X-rays: radiography, tomography, diffraction topography

JOURNAL OF SYNCHROTRON RADIATION, Issue 3 2000
José Baruchel
Several hard X-rays imaging techniques greatly benefit from the coherence of the beams delivered by the modern synchrotron radiation sources. This is illustrated with examples recorded on the `long' (145,m) ID19 `imaging' beamline of the ESRF. Phase imaging is directly related to the small angular size of the source as seen from one point of the sample (`effective divergence' , microradians). When using the `propagation' technique, phase radiography and tomography are instrumentally very simple. They are often used in the `edge detection' regime, where the jumps of density are clearly observed. The in situ damage assessment of micro-heterogeneous materials is one example of the many applications. Recently a more quantitative approach has been developed, which provides a three-dimensional density mapping of the sample (`holotomography'). The combination of diffraction topography and phase-contrast imaging constitutes a powerful tool. The observation of holes of discrete sizes in quasicrystals, and the investigation of poled ferroelectric materials, result from this combination [source]

Softwaregestützte Kostenermittlung für die Gebäudeinstandsetzung

BAUTECHNIK, Issue 8 2009
Christoph A. Beecken Dipl.-Ing.
Baubetrieb; Bauwerkserhaltung/Sanierung; Construction Management; Maintenance/Rehabilitation Abstract In diesem Beitrag werden Möglichkeiten der softwaregestützten Kostenermittlung für die Instandsetzung vorgestellt, die in den vergangenen Jahren im Rahmen mehrerer Instandsetzungsprojekte entwickelt wurden und für unterschiedlichste Gebäudetypen anwendbar sind. Schwerpunkte sind die zügige und präzise Schadenserfassung und -bewertung als Schlüsselfaktoren für die Ermittlung der zu erwartenden Baukosten. Am konkreten Beispiel werden die Vorteile der softwaregestützten Schadenserfassung und -bewertung beschrieben, und es wird der Bezug zur Praxis hergestellt. Computer aided cost calculation for building repair. This paper shows ways of software aided cost calculation for rehabilitation of buildings, which have been developed in recent years in several repair projects and which are applicable for various building types. The advantages of automated damage assessment and evaluation are described at an example of a parking garage and are related to the practice. [source]