5 resultados para fire analysis

em Digital Commons at Florida International University


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The purpose of this research was to study interfering products in fire debris analysis, including their identification and characterization. Different substrates were classified, burned, extracted and analyzed in order to identify all the interfering products that they may release. It has been shown that these products come from three different sources: substrate background products, pyrolysis products and possibly combustion products. Different parameters in the creation of these products were evaluated such as the extinguishment process as well as the weathering of the sample prior to the analysis. It has been shown that the presence of these products is not always constant and thus, makes it difficult to extrapolate data to similar cases. Furthermore, some of these products are similar to the ones found in ignitable liquids. Finally, it shows one more time how important it is to collect and analyze control samples in fire debris analysis. ^

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Increased device density, switching speeds of integrated circuits and decrease in package size is placing new demands for high power thermal-management. The convectional method of forced air cooling with passive heat sink can handle heat fluxes up-to 3-5W/cm2; however current microprocessors are operating at levels of 100W/cm2, This demands the usage of novel thermal-management systems. In this work, water-cooling systems with active heat sink are embedded in the substrate. The research involved fabricating LTCC substrates of various configurations - an open-duct substrate, the second with thermal vias and the third with thermal vias and free-standing metal columns and metal foil. Thermal testing was performed experimentally and these results are compared with CFD results. An overall thermal resistance for the base substrate is demonstrated to be 3.4oC/W-cm2. Addition of thermal vias reduces the effective resistance of the system by 7times and further addition of free standing columns reduced it by 20times.

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How do local homeland security organizations respond to catastrophic events such as hurricanes and acts of terrorism? Among the most important aspects of this response are these organizations ability to adapt to the uncertain nature of these "focusing events" (Birkland 1997). They are often behind the curve, seeing response as a linear process, when in fact it is a complex, multifaceted process that requires understanding the interactions between the fiscal pressures facing local governments, the institutional pressures of working within a new regulatory framework and the political pressures of bringing together different levels of government with different perspectives and agendas. ^ This dissertation has focused on tracing the factors affecting the individuals and institutions planning, preparing, responding and recovering from natural and man-made disasters. Using social network analysis, my study analyzes the interactions between the individuals and institutions that respond to these "focusing events." In practice, it is the combination of budgetary, institutional, and political pressures or constraints interacting with each other which resembles a Complex Adaptive System (CAS). ^ To investigate this system, my study evaluates the evolution of two separate sets of organizations composed of first responders (Fire Chiefs, Emergency Management Coordinators) and community volunteers organized in the state of Florida over the last fifteen years. Using a social network analysis approach, my dissertation analyzes the interactions between Citizen Corps Councils (CCCs) and Community Emergency Response Teams (CERTs) in the state of Florida from 1996–2011. It is the pattern of interconnections that occur over time that are the focus of this study. ^ The social network analysis revealed an increase in the amount and density of connections between these organizations over the last fifteen years. The analysis also exposed the underlying patterns in these connections; that as the networks became more complex they also became more decentralized though not in any uniform manner. The present study brings to light a story of how communities have adapted to the ever changing circumstances that are sine qua non of natural and man-made disasters.^

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This is an empirical study whose purpose was to examine the process of innovation adoption as an adaptive response by a public organization and its subunits existing under varying degrees of environmental uncertainty. Meshing organization innovation research and contingency theory to form a theoretical framework, an exploratory case study design was undertaken in a large, metropolitan government located in an area with the fourth highest prevalence rate of HIV/AIDS in the country. A number of environmental and organizational factors were examined for their influence upon decision making in the adoption/non-adoption as well as implementation of any number of AIDS-related policies, practices, and programs.^ The major findings of the study are as follows. For the county government itself (macro level), no AIDS-specific workplace policies have been adopted. AIDS activities (AIDS education, AIDS Task Force, AIDS Coordinator, etc.), adopted county-wide early in the epidemic, have all been abandoned. Worker infection rates, in the aggregate and throughout the epidemic have been small. As a result, absent co-worker conflict (isolated and negligible), no increase in employee health care costs, no litigation regarding discrimination, and no major impact on workforce productivity, AIDS has basically become a non-issue at the strategic core of the organization. At the departmental level, policy adoption decisions varied widely. Here the predominant issue is occupational risk, i.e., both objective as well as perceived. As expected, more AIDS-related activities (policies, practices, and programs) were found in departments with workers known to have significant risk for exposure to the AIDS virus (fire rescue, medical examiner, police, etc.). AIDS specific policies, in the form of OSHA's Bloodborn Pathogen Standard, took place primarily because they were legislatively mandated. Union participation varied widely, although not necessarily based upon worker risk. In several departments, the union was a primary factor bringing about adoption decisions. Additional factors were identified and included organizational presence of AIDS expertise, availability of slack resources, and the existence of a policy champion. Other variables, such as subunit size, centralization of decision making, and formalization were not consistent factors explaining adoption decisions. ^

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Within the marl prairie grasslands of the Florida Everglades, USA, the combined effects of fire and flooding usually lead to very significant changes in tree island structure and composition. Depending on fire severity and post-fire hydroperiod, these effects vary spatially and temporally throughout the landscape, creating a patchy post-fire mosaic of tree islands with different successional states. Through the use of the Normalized Difference Vegetation Index (NDVI) and three predictor variables (marsh water table elevation at the time of fire, post-fire hydroperiod, and tree island size), along with logistic regression analysis, we examined the probability of tree island burning and recovering following the Mustang Corner Fire (May to June 2008) in Everglades National Park. Our data show that hydrologic conditions during and after fire, which are under varying degrees of management control, can lead to tree island contraction or loss. More specifically, the elevation of the marsh water table at the time of the fire appears to be the most important parameter determining the severity of fire in marl prairie tree islands. Furthermore, in the post-fire recovery phase, both tree island size and hydroperiod during the first year after the fire played important roles in determining the probability of tree island recovery, contraction, or loss.