Earthquake and ambient vibration monitoring of the steel frame UCLA Factor building

Dynamic property measurements of the moment-resisting steel-frame University of California, Los Angeles, Factor building are being made to assess how forces are distributed over the building. Fourier amplitude spectra have been calculated from several intervals of ambient vibrations, a 24-hour period of strong winds, and from the 28 March 2003 Encino, California (M_L =2.9), the 3 September 2002 Yorba Linda, California (M_L=4.7), and the 3 November 2002 Central Alaska (M_w=7.9) earthquakes. Measurements made from the ambient vibration records show that the first-mode frequency of horizontal vibration is between 0.55 and 0.6 Hz. The second horizontal mode has a frequency between 1.6 and 1.9 Hz. In contrast, the first-mode frequencies measured from earthquake data are about 0.05 to 0.1 Hz lower than those corresponding to ambient vibration recordings indicating softening of the soil-structure system as amplitudes become larger. The frequencies revert to pre-earthquake levels within five minutes of the Yorba Linda earthquake. Shaking due to strong winds that occurred during the Encino earthquake dominates the frequency decrease, which correlates in time with the duration of the strong winds. The first shear wave recorded from the Encino and Yorba Linda earthquakes takes about 0.4 sec to travel up the 17-story building

Disaster resilience analysis of urban transportation networks to support decision-making on planning and expansion

HUB-Istanbul work package (WP) 2.6 aims to evaluate multi-hazard resilience analysis of urban transportation networks and suggest the potential approach for analysing the case study area, Fikirtepe, Istanbul, Turkey. Research outcomes will be conveyed by five deliverables. The first deliverable summarised the overall framework of analysis and required data for assessing physical vulnerability. Based on the framework, this second deliverable deals with the collection and handing of the data required to evaluate traffic functionality of roadways and system, while discussing characteristics and challenges in analysing transport systems, methods for quantifying system functionality, probabilistic analysis framework and selected analysis parameters in the present study. Based on the framework and datasets summarised in the first two deliverables, the third deliverable will develop a probabilistic model to incorporate multi-layered analysis and data, which will be demonstrated by pilot examples. The fourth deliverable will present a thorough analysis of real-world transportation networks in the case study area, including mapping, network analysis and network performance evaluation. The evaluation results should be used to support decisions through mathematically formulated decision tasks, which will be illustrated in the fifth deliverable. This second deliverable summarises the risk assessment of urban transportation networks, including the characteristics of urban transportation networks, evaluation of system functionality and probabilistic inference to support decision-making. Based on the investigation, this deliverable proposes the analysis framework and parameters to be used in this project, with a focus on the study area, Fikirtepe, Istanbul, Turkey

Preliminary investigation of multi-hazard resilience analysis for urban transportation networks and data availability for hazard models and vulnerability of physical objects

HUB-Istanbul work package (WP) 2.6 aims to develop tools to analyse the multi-hazard resilience of urban transportation network in complex and evolving metropolitan environment, and propose a demonstrative application to a case study area: Fikirtepe in Istanbul, Turkey. Research outcomes will be conveyed by five deliverables. This document is the first deliverable, summarising the overall framework of analysis and required data for assessing physical vulnerability. Based on the framework, the second deliverable will deal specifically with another type of data required to evaluate traffic functionality of roadways and network performance. Based on the framework and datasets identified in the first two deliverables, the third deliverable will develop a probabilistic model to incorporate multi-layered analysis and data, which will be demonstrated by pilot examples. The fourth deliverable will present a thorough analysis of real-world transportation networks in the case study area, including mapping, network analysis and network performance evaluation. The evaluation results should be used to support decisions through mathematically formulated decision tasks, which will be illustrated in the fifth deliverable. This first deliverable summarises and proposes the research objectives, the framework of multi-hazard disaster resilience analysis of urban transportation networks and data requirement for assessing physical vulnerability, which are accompanied with thorough literature review. Based on the development, major hazard threats and distributions of bridges are identified for the case study area, Fikirtepe in Istanbul, Turkey

Hypoxia induces dilated cardiomyopathy in the chick embryo: mechanism; intervention; and long-term consequences.

Background Intrauterine growth restriction is associated with an increased future risk for developing cardiovascular diseases. Hypoxia in utero is a common clinical cause of fetal growth restriction. We have previously shown that chronic hypoxia alters cardiovascular development in chick embryos. The aim of this study was to further characterize cardiac disease in hypoxic chick embryos. Methods Chick embryos were exposed to hypoxia and cardiac structure was examined by histological methods one day prior to hatching (E20) and at adulthood. Cardiac function was assessed in vivo by echocardiography and ex vivo by contractility measurements in isolated heart muscle bundles and isolated cardiomyocytes. Chick embryos were exposed to vascular endothelial growth factor (VEGF) and its scavenger soluble VEGF receptor-1 (sFlt-1) to investigate the potential role of this hypoxia-regulated cytokine. Principal Findings Growth restricted hypoxic chick embryos showed cardiomyopathy as evidenced by left ventricular (LV) dilatation, reduced ventricular wall mass and increased apoptosis. Hypoxic hearts displayed pump dysfunction with decreased LV ejection fractions, accompanied by signs of diastolic dysfunction. Cardiomyopathy caused by hypoxia persisted into adulthood. Hypoxic embryonic hearts showed increases in VEGF expression. Systemic administration of rhVEGF165 to normoxic chick embryos resulted in LV dilatation and a dose-dependent loss of LV wall mass. Lowering VEGF levels in hypoxic embryonic chick hearts by systemic administration of sFlt-1 yielded an almost complete normalization of the phenotype. Conclusions/Significance Our data show that hypoxia causes a decreased cardiac performance and cardiomyopathy in chick embryos, involving a significant VEGF-mediated component. This cardiomyopathy persists into adulthood

Hypoxia induces dilated cardiomyopathy in the chick embryo: mechanism, intervention, and long-term consequences

Background: Intrauterine growth restriction is associated with an increased future risk for developing cardiovascular diseases. Hypoxia in utero is a common clinical cause of fetal growth restriction. We have previously shown that chronic hypoxia alters cardiovascular development in chick embryos. The aim of this study was to further characterize cardiac disease in hypoxic chick embryos. Methods: Chick embryos were exposed to hypoxia and cardiac structure was examined by histological methods one day prior to hatching (E20) and at adulthood. Cardiac function was assessed in vivo by echocardiography and ex vivo by contractility measurements in isolated heart muscle bundles and isolated cardiomyocytes. Chick embryos were exposed to vascular endothelial growth factor (VEGF) and its scavenger soluble VEGF receptor-1 (sFlt-1) to investigate the potential role of this hypoxia-regulated cytokine. Principal Findings: Growth restricted hypoxic chick embryos showed cardiomyopathy as evidenced by left ventricular (LV) dilatation, reduced ventricular wall mass and increased apoptosis. Hypoxic hearts displayed pump dysfunction with decreased LV ejection fractions, accompanied by signs of diastolic dysfunction. Cardiomyopathy caused by hypoxia persisted into adulthood. Hypoxic embryonic hearts showed increases in VEGF expression. Systemic administration of rhVEGF165 to normoxic chick embryos resulted in LV dilatation and a dose-dependent loss of LV wall mass. Lowering VEGF levels in hypoxic embryonic chick hearts by systemic administration of sFlt-1 yielded an almost complete normalization of the phenotype. Conclusions/Significance: Our data show that hypoxia causes a decreased cardiac performance and cardiomyopathy in chick embryos, involving a significant VEGF-mediated component. This cardiomyopathy persists into adulthood

Vibration of Buildings Under Random Wind Loads

141 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1980.Wind and earthquakes are two of the major environmental forces acting on multistory buildings. Since current design practice often leads to slender and flexible buildings, the dynamic effects of the wind are of increasing importance. The purpose of this study was to develop a method for analyzing the three-dimensional dynamic response of buildings subjected to random wind loads.The analysis procedure utilizes random vibration techniques and parallels the gust factor methods currently used in engineering practice. Expressions for the spectra of the along wind forces, of the across-wind forces induced by vortex shedding and of the total dynamic torque were developed for normally incident wind. Rectangular buildings were modeled as either three-dimensional continuous shear beams or flexural beams. The results of the analysis are the expected maximum translation and acceleration of any point on the structure. The method is quite general and may be extended to include the analysis of buildings subjected to earthquake-type loadings.Results of the analysis procedure compare quite favorably with measurements from full-scale tests. Several examples are presented to illustrate the significance of various parameters on the total response of buildings.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD