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Existing Infrastructure (existing + infrastructure)

Distribution by Scientific Domains

Engineering	50%

Selected Abstracts

Strategies for Successful Marine Conservation: Integrating Socioeconomic, Political, and Scientific Factors

CONSERVATION BIOLOGY, Issue 6 2005
CAROLYN J. LUNDQUIST
áreas marinas protegidas; planificación de conservación; reservas marinas Abstract:,As the process of marine-protected-area design and implementation evolves, the incorporation of new tools will advance our ability to create and maintain effective protected areas. We reviewed characteristics and approaches that contribute to successful global marine conservation efforts. One successful characteristic emphasized in most case studies is the importance of incorporating stakeholders at all phases of the process. Clearly defined goals and objectives at all stages of the design process are important for improved communication and standardized expectations of stakeholder groups. The inclusion of available science to guide the size and design of marine protected areas and to guide clear monitoring strategies that assess success at scientific, social, and economic levels is also an important tool in the process. Common shortcomings in marine conservation planning strategies include government instability and resultant limitations to monitoring and enforcement, particularly in developing nations. Transferring knowledge to local community members has also presented challenges in areas where in situ training, local capacity, and existing infrastructure are sparse. Inaccessible, unavailable, or outdated science is often a limitation to conservation projects in developed and developing nations. To develop and maintain successful marine protected areas, it is necessary to acknowledge that each case is unique, to apply tools and lessons learned from other marine protected areas, and to maintain flexibility to adjust to the individual circumstances of the case at hand. Resumen:,A medida que evoluciona el proceso de diseño e implementación de áreas marinas protegidas, la incorporación de nuevas herramientas mejorará nuestra habilidad para crear y mantener áreas protegidas efectivas. Revisamos las características y enfoques que contribuyen a los esfuerzos exitosos de conservación marina global. La importancia de incorporar a los actores en todas las fases del proceso es una característica exitosa enfatizada en la mayoría de los estudios de caso. Es importante que haya metas y objetivos claramente definidos para todas las etapas del proceso de diseño para mejorar la comunicación y estandarizar las expectativas de los grupos interesados. La inclusión de la ciencia disponible para guiar el tamaño y diseño de áreas marinas protegidas y para guiar las estrategias de monitoreo que evalúa el éxito a nivel científico, social y económico también son herramientas importantes en el proceso. Defectos comunes en las estrategias de planificación de conservación marina incluyen la inestabilidad gubernamental y las resultantes limitaciones para el monitoreo y vigilancia, particularmente en países en desarrollo. La transferencia de conocimiento a miembros de la comunidad local también ha enfrentado retos en áreas donde el entrenamiento in situ, la aptitud local y la infraestructura existente son escasos. La ciencia inaccesible, no disponible u obsoleta a menudo es una limitación para los proyectos de conservación en países desarrollados y en desarrollo. Para desarrollar y mantener áreas marinas protegidas exitosas, es necesario reconocer que cada caso es único, aplicar herramientas y lecciones aprendidas en otras áreas marinas protegidas y mantener la flexibilidad para ajustarse a las circunstancias individuales de cada caso. [source]

Response simulation and seismic assessment of highway overcrossings

EARTHQUAKE ENGINEERING AND STRUCTURAL DYNAMICS, Issue 9 2010
Anastasios Kotsoglou
Abstract Interaction of bridge structures with the adjacent embankment fills and pile foundations is generally responsible for response modification of the system to strong ground excitations, to a degree that depends on soil compliance, support conditions, and soil mass mobilized in dynamic response. This paper presents a general modeling and assessment procedure specifically targeted for simulation of the dynamic response of short bridges such as highway overcrossings, where the embankment soil,structure interaction is the most prevalent. From previous studies it has been shown that in this type of interaction, seismic displacement demands are magnified in the critical bridge components such as the central piers. This issue is of particular relevance not only in new design but also in the assessment of the existing infrastructure. Among a wide range of issues relevant to soil,structure interaction, typical highway overcrossings that have flexible abutments supported on earth embankments were investigated extensively in the paper. Simulation procedures are proposed for consideration of bridge-embankment interaction effects in practical analysis of these structures for estimation of their seismic performance. Results are extrapolated after extensive parametric studies and are used to extract ready-to-use, general, and parameterized capacity curves for a wide range of possible material properties and geometric characteristics of the bridge-embankment assembly. Using two instrumented highway overpasses as benchmark examples, the capacity curves estimated using the proposed practical procedures are correlated successfully with the results of explicit incremental dynamic analysis, verifying the applicability of the simple tools developed herein, in seismic assessment of existing short bridges. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Requirements for ground investigations in shield tunnelling / . Anforderungen an die Baugrunderkundung für Schildvortriebe

GEOMECHANICS AND TUNNELLING, Issue 3 2010
Dietmar Placzek Prof. Dr.-Ing.Article first published online: 1 JUN 2010
Mechanized tunnelling; Reconnaissance; Maschineller Vortrieb; Baugrunderkundung Abstract The success of a tunnel project depends on successfully overcoming the ground conditions and the geological risks. Despite this basic fact, the production of technical regulations and guidelines, the further development of machine technology and improving methods of surveying and control, mishaps still often occur during tunnel drives, affecting either the tunnel itself or the surroundings, e.g. existing infrastructure or buildings. The causes are often multifaceted but can almost always be attributed to the existing ground conditions, which had not been appropriately determined, described, or considered in the design, or taken into account during construction. The following explanations describe the risks inherent in ground conditions and show how these risks can be countered by appropriate ground investigations for tunnelling. Der Erfolg eines Tunnelvortriebs hängt von der sicheren Beherrschung des Baugrunds und der hierin liegenden Risiken ab. Trotz dieser grundlegenden Erkenntnis, der Erarbeitung von technischen Vorschriften und Richtlinien, der Weiterentwicklung der Maschinentechnik sowie einer verfeinerten Mess- und Steuerungstechnik kommt es immer Tunnelvortrieb wieder beim zu Schäden, die entweder unmittelbar den Vortrieb selbst oder das Umfeld, z. B. bestehende Infrastruktur oder Bauwerke, betreffen. Die Ursachen sind häufig vielfältiger Natur, lassen sich aber überwiegend auf die vorherrschenden Baugrundverhältnisse zurückführen, die entweder nicht zutreffend ermittelt, beschrieben, planerisch umgesetzt oder ausführungstechnisch berücksichtigt wurden. Die nachfolgenden Ausführungen beschreiben die im Baugrund vorhandenen Risiken und zeigen auf, wie diesen Risiken durch gezielte Baugrunduntersuchungen für den Tunnelbau begegnet werden kann. [source]

Zygomatic complex fractures in a suburban Nigerian population

DENTAL TRAUMATOLOGY, Issue 2 2005
Vincent Ugboko
Abstract,,, A retrospective analysis of 128 zygomatic complex fractures was undertaken. There were 109 males (85.2%) and 19 females (14.8%), aged 3,74 years (mean ± SD, 33 ± 12.6 years). Patients in the third decade of life (38.3%) recorded the highest incidence. Road traffic accidents (74.2%) mainly from automobile (61.7%) and motorcycle (9.4%) involvement were the predominant etiology. While 38.8% of them presented within the first 24 h, males were relatively earlier than their female counterparts, although this was not statistically significant (P > 0.05). Class 3 fractures were the commonest (50%), followed by classes 2 (zygomatic arch) and 4, respectively. Most class 6 fractures (6.3%) resulted from gunshot injuries. There were 116 unilateral (left 63, right 53) and 12 bilateral fractures with the right side of the face recording more zygomatic arch fractures. In addition, statistical significance was observed between etiology, class and type of fracture (P < 0.05). One hundred and twenty-four (136 fractures) patients were available for treatment as four declined. Twelve cases did not require treatment while others were managed by either closed or open reduction under general anesthesia. Gillies' temporal approach was the commonest (57.1%) surgical technique employed. However the unstable nature of the fractures necessitated open reduction and transosseous wiring in 33 cases. The high prevalence of zygomatic complex fractures arising from vehicular accidents reflects the poor status of the road network in rural and suburban Nigerian communities. Hence government should improve on existing infrastructures, decongest the highways and enforce traffic laws amongst road users. In addition, the need to encourage massive investments in safer alternative transport systems is emphasized. [source]