Submitted by SIMONE SIMÕES AMARAL null (simonesimoessi@gmail.com) on 2017-05-05T16:13:41Z No. of bitstreams: 1 Versão Final.pdf: 7430161 bytes, checksum: 3a44590f9683d726da54963b426f3ee7 (MD5) / Approved for entry into archive by Luiz Galeffi (luizgaleffi@gmail.com) on 2017-05-05T16:16:02Z (GMT) No. of bitstreams: 1 amaral_ss_dr_guara.pdf: 7430161 bytes, checksum: 3a44590f9683d726da54963b426f3ee7 (MD5) / Made available in DSpace on 2017-05-05T16:16:02Z (GMT). No. of bitstreams: 1 amaral_ss_dr_guara.pdf: 7430161 bytes, checksum: 3a44590f9683d726da54963b426f3ee7 (MD5) Previous issue date: 2017-04-12 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Apesar das novas tecnologias de gerenciamento e combate aos incêndios, o fogo em florestas ainda ocorre em grande escala, causando danos ao meio ambiente e à sociedade. Os danos causados pelo fogo são dependentes de fatores como combustível, clima e topografia do terreno. Para minimização e controle dos efeitos causados pelo fogo é importante o estudo de tais fatores. Assim, o objetivo deste trabalho foi analisar a condição que potencializa a propagação do fogo e a emissão de poluentes gasosos. O estudo da condição que potencializa o fogo e suas emissões foi realizado para biomassas de florestas plantadas. Os principais fatores, que afetam o fogo e suas emissões, foram avaliados através de experimentos de laboratório. Os fatores de controle avaliados foram: espécie, percentual de liteira, carga de combustível, irradiância solar, umidade relativa, velocidade do vento e inclinação do terreno. Estes experimentos foram planejados e analisados utilizando a matriz L18 da metodologia de Taguchi. O dispositivo de queima foi adaptado, para que o estudo pudesse ser realizado. As emissões também foram quantificadas para floresta nativa (biomassa da Amazônia), com experimentos conduzidos em campo e em laboratório. Para os níveis dos fatores estabelecidos, em laboratório, a condição encontrada que potencializou a propagação do fogo e a emissão de poluentes gasosos foi a queima de Eucalyptus sp., com aproximadamente 30 % de liteira, carga de 2,5 kg de combustível, nível mínimo de umidade relativa (40 %), velocidade do vento de 3,5 m/s e inclinação do terreno de 30°. A máxima irradiância (1kW/m2) potencializou as emissões gasosas, cujos valores de fator de emissão foram de 1.495±62 g/kg para CO2, 71,52±4,33 g/kg para CO, 1,96±0,78 g/kg para NO e 14,75±3,55 g/kg para UHC. Experimentos conduzidos com a irradiância no nível 1 potencializaram a propagação do fogo. Quando comparados os resultados de queima de biomassa da Amazônia, a queima em campo apresentou valores mais elevados das emissões por hectare, para os compostos parcialmente oxidados. / Despite the new technologies of management and fire fighting, fire in forests still occurs on a large scale, causing damage to the environment and society. The damages caused by the fire are dependent on factors such as fuel, weather, and topography of the land. To minimize and control the effects caused by fire is important the study of such factors. Thus, the objective of this work was to analyze the condition that enhances the spread of fire and the emission of gaseous pollutants. The study of the condition that enhances the fire and their emissions was conducted for biomasses of planted forests. The main factors, which affect the fire, were evaluated through laboratory experiments. The control factors evaluated were: specie, percentage of litter, fuel load, irradiance, relative humidity, wind speed and inclination. These experiments were designed and analyzed using the matrix L18 of Taguchi methodology. The burning device was adapted, so that the study could be performed. The emissions were also quantified to native forest (Amazon biomass), with experiments conducted in the field and in the laboratory. For the levels of the established factors, the condition found that enhanced the spread of fire and the emission of gaseous pollutants was: Eucalyptus sp. burning, with approximately 30% litter, 2.5 kg of fuel load, minimum relative humidity (40%), wind velocity of 3.5 m/s and inclination of 30°. The maximum irradiance (1kW/m2) potentiated the gaseous emissions, whose emission factor values were 1,495 ± 62 g/kg for CO2, 71.52 ± 4.33 g/kg for CO, 1.96 ± 0.78 g/kg for NO and 14.75 ± 3.55 g/kg for UHC. Experiments conducted with irradiance at level 1 enhanced the spread of fire. When the results of the Amazon biomass burning were compared, field burning presented higher emissions per hectare, for partially oxidized compounds. / FAPESP: 2013/21231-0

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-10-04T22:24:00Z No. of bitstreams: 1 MichelleCristinaVarelaDosSantos_DISSERT.pdf: 2578443 bytes, checksum: cbf87aab557f25c12ac2e240f11654b7 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-10-13T21:55:18Z (GMT) No. of bitstreams: 1 MichelleCristinaVarelaDosSantos_DISSERT.pdf: 2578443 bytes, checksum: cbf87aab557f25c12ac2e240f11654b7 (MD5) / Made available in DSpace on 2017-10-13T21:55:18Z (GMT). No. of bitstreams: 1 MichelleCristinaVarelaDosSantos_DISSERT.pdf: 2578443 bytes, checksum: cbf87aab557f25c12ac2e240f11654b7 (MD5) Previous issue date: 2017-03-30 / Entre o final do s?culo XX e in?cio do s?culo XXI, muitos cientistas passaram a se interessar na din?mica de sistemas complexos e os fen?menos envolvidos, tais como, os sistemas cr?ticos. Esses sistemas n?o-lineares apresentam propriedades descritas por leis de pot?ncia. Fen?menos cr?ticos constituem sistemas complexos, que n?o possuem propriedades bem descritas pelas leis da termodin?mica. O presente trabalho apresenta um modelo energ?tico critico auto-organizado, ou seja, que possui Criticalidade Auto-Organizada (SOC), criado para explicar a atividade coletiva espont?nea em um tecido animal sem a necessidade de um controle muscular ou de sistema nervoso central. O modelo prot?tipo descreve um tecido epitelial cuboide formado por uma ?nica camada de c?lulas, como a cavidade digestiva interna de alguns animais simples ou primitivos. O tecido ? composto por c?lulas que absorvem nutrientes e armazenam energia, com probabilidade p, para participar de atividade do tecido. Cada c?lula pode estar em dois estados: o de alta energia capaz de se tornar ativa ou de baixo consumo metab?lico e em repouso. Qualquer c?lula pode ser ativada espontaneamente, com uma probabilidade muito baixa, e ent?o propagar uma atividade coletiva entre seus vizinhos que compartilham energia suficiente. As c?lulas do tecido que participam da atividade consomem toda a sua energia. Foi observada uma rela??o tipo lei de pot?ncia, P(s) ? s?, para a probabilidade de ter um movimento coletivo de tamanho s. A constru??o deste modelo ? an?logo ao modelo Forest Fire Model. Essa abordagem produz naturalmente um estado cr?tico para a atividade do tecido animal, al?m de explicar a auto sustenta??o das atividades em um tecido animal vivo sem controle de feedback. / Since the end of the twentieth century and the beginning of the twenty-first century, many scientists have become interested in the study of the dynamics of complex systems and in critical systems. This class of non-linear systems has properties described by power laws. Critical phenomena is characteristics of complex systems that has properties not well described by the laws of thermodynamics. The present work presents a self-organized critical (SOC) energy model, created to explain spontaneous collective activity in a given animal tissue without the necessity of a muscular control or central nervous system. This prototype model introduces a cuboid epithelial tissue formed by a single layer of cells, such as the internal digestive cavity of some primitive animals. The tissue is composed of cells that absorb nutrients and store energy, with probability p, to participate in a collective tissue motion. Each cell can be in two states: the high-energy state able to become active or low-metabolic and at rest. Any cell can be activated spontaneously, with a very low probability, and starts a collective activity with its neighbors that share enough energy. The tissue cells that participate in the oscillation consume all their energy. It is observed a power law relation, P(s) ? s?, for the probability of having a collective motion with s cells. The construction of this model is analogous to the Forest Fire SOC model. This approach naturally produces a critical condition for the oscillation of the animal tissue, in addition, it explains self-sustaining activities in a living animal tissue without feedback control.

Orientador: Anne Hélène Fostier / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-22T11:06:51Z (GMT). No. of bitstreams: 1 MelendezPerez_JoseJavier_M.pdf: 2237869 bytes, checksum: 3710e09e3870c2884c380a0ae8589f27 (MD5) Previous issue date: 2013 / Resumo: O presente trabalho buscou avaliar o impacto da queima de florestas na região Amazônica sobre as emissões de Hg devidas, tanto à queima de biomassa, quanto do solo durante a queimada. Grande parte dos dados necessários foi adquirida a partir de um experimento de queimada programada, numa parcela de floresta de 2,25 ha localizada na estação experimental da EMBRAPA, em Rio Branco (Acre), que foi realizada em setembro de 2011. O fator de emissão de Hg, definido aqui como a massa de Hg emitida por área de floresta, foi calculado pela diferença no estoque de Hg antes e depois da queima obtendo um valor de aproximadamente 4 g Hg ha. Para determinar o fator de emissão foram coletadas e analisadas amostras de solos e vegetação. A concentração de Hg nas amostras coletadas foi determinada usando um método de análise direto por decomposição térmica da amostra e detecção por absorção atômica, que evita a maioria dos processos típicos de pré-tratamento da amostra como digestões acidas, redução do Hg(II) e etapas de separação líquido-gás. Este trabalho integra-se a um amplo programa de estudos destinados a quantificar as principais emissões e parâmetros de consumo de biomassa em queimas de floresta amazônica desenvolvidos por pesquisadores do Instituto Nacional de Pesquisas Espaciais (INPE) e da Universidade Estadual Paulista (UNESP). Estes realizaram um inventário florístico no sitio de estudo e forneceram os dados de biomassa e de eficiência de combustão necessários para os cálculos do fator de emissão. Também foi realizado um estudo de especiação de Hg no solo da floresta, onde foi encontrando que a espécie predominante é o Hg(II). Foram avaliados alguns indicadores da severidade do fogo durante a queima da floresta, tais como o registro de temperatura do solo e a relação Ca/C no solo superficial da floresta. / Abstract: The present work aims to assess the impact of forest fires in the Amazonian region on mercury emissions due to biomass and soil burning during the fire. A large part of the data was obtained from an experimental burning of a 2.25 ha forest plot, located in the EMBRAPA experimental field station near Rio Branco (Acre), carried out in September 2011. The mercury emission factor, defined here as the mass of mercury emitted per area of forest, was calculated by the difference of mercury burden before and after fire and it was found a value of about 4 g ha. Before burning experiment, samples of vegetation (leaves, wood and litterfall) and soil (up to 5 cm deep) were collected. The mercury concentration of the samples was determined by using a method of direct mercury analysis based on thermal decomposition of the sample and atomic absorption detection, avoiding most of the typical processes for sample pretreatment such as acidic digestion, Hg(II) reduction and gas-liquid separation steps. This work is part of a large study which aims to quantify the main emission and consumption parameters of Amazonian forest fires which and is conducted by researchers from the Instituto Nacional de Pesquisas Espaciais (INPE) and the Universidade Estadual Paulista (UNESP). They performed a floristic inventory from the experimental plot and provided the biomass and combustion efficiency data necessary for emission factor calculation. A speciation study of mercury was performed in the forest soil, by using a technique of termodessorption coupled with atomic absorption, where it was found that the predominant specie was Hg(ll). Parameters like temperatures recorded with thermocouples in some depths during the forest fire and Ca/C ratio of superficial soil were assessed as indicators of fire severity. / Mestrado / Quimica Analitica / Mestre em Química

Forest fires has become an increasing threat all over the world. Pollution and rising greenhouse gases has led to an ever increase in global temperatures. Sweden has previously been spared from larger fires, but in the past few year it has been been made clear that these climate changes will affect the number and intensity of forest fires.  In this project I have investigated how forest fires work and how the process of  extinguishing them looks today. With a focus on the personal equipment I have looked into how to improve the working environment and the safety for fire-fighters. Using the design process this problem is tackled from a holistic point of view, looking at both the users and context. The solutions presented in this project is a professional safety product called “Phoenix. PPe Wildfire respirator”. A lightweight portable oxygen harness with an attached emergency mask.

Our model considers a new element in forest fire modeling, namely the dynamics of a forest animal, intimately linked to the trees. We show that animals and trees react differently to different types of fire. A high probability of fire initiation results in several small fires, which do not allow for a large fuel accumulation and thus the destruction of many trees by fire, but is found to be generally devastating to the animal population at the same time. On the other hand, a low fire initiation probability allows for the accumulation of higher quantities of fuel, which in turn results in larger fires, more devastating to the trees than to the animals. Thus, we suggest that optimal fire management should take into account the relation between fire initiation and its different effects on animals and trees. Further, wildfires are often considered as prime examples for power-law-like frequency distributions, yet there is no agreement on the mechanisms responsible for the observed patterns. Our model suggests that instead of a single unified distribution, a superposition of at least two different distributions can be detected and this suggests multiform mechanisms acting on different scales. None of the discovered distributions are compatible with the power-law hypothesis.

I litteratursökningen fann vi stöd för två hypoteser, att de överlevande träden efterbrand kunde uppleva en tillväxthämning eller en tillväxtökning.För att utreda detta borrades 88 träd på 5 olika områden, varav hälften var obrända trädi intilliggande bestånd. Därefter macrofotograferades borrspånen för att mätaårsringsbredden digitalt. Datan sammanställdes och analyserades sedan.Resultaten från de enskilda områdena visade tillväxtökning, tillväxtminskning elleringen tillväxtförändring som en brandeffekt. För att undersöka detta vidare sålikställdes brandåret för alla områden och sammanställdes till ett totalt medelvärde,detta påvisade en marginellt positiv effekt av branden.Slutsatsen är att många störande variabler påverkade resultatet, dessa variabler agerar isamverkan för att påverka tillväxten och denna studie lyckades inte isolera brandenseffekt. Den totala sammanställningen visar endast en marginell effekt av branden, detberor på att ett område visade en tillväxtökning och ett annat område visade entillväxtminskning, dessa två tar således ut varandra.

Current fire-spread models are based largely on empirical correlations based on fires burning through dead pine needles. There is a need to increase the accuracy of modeling wildfires in live vegetation. This project investigates the quantitative and qualitative ignition characteristics of eight live fuels, four from southern California (manzanita, scrub oak, ceanothus, and chamise) and four from Utah (canyon maple, gambel oak, big sagebrush, and Utah juniper). Individual leaves were observed as they were exposed to hot gases from a flat flame burner. The broadleaf species from both California and Utah had noticeable surface changes during the ignition process. All fresh samples showed a color change on the leaf surface from a light dusty color to a dark wet color. This is likely due to the melting of the waxy protective layer. Samples of scrub oak, manzanita, ceanothus, canyon maple, and gambel oak at moderate moisture contents (50 to 75%) exhibited bubbling under the leaf surface. Liquid droplets were observed on the surface of Manzanita samples at moisture contents near 75%, while bursting was observed on the surface at moisture contents near 100%. This bursting is due to evaporation of the moisture inside the leaf causing internal pressures to exceed the surface strength of the leaf. Ignition was defined as the time when the first visible gaseous flame was observed near the leaf surface. Measurements of the time to ignition and the temperature at ignition were performed for all broadleaf species. A large degree of scatter was observed in the quantitative ignition data, due largely to variations in leaf thickness and moisture content. Time to ignition was found to correlate with sample thickness and the mass of moisture in the sample. Ignition temperature was constant for varying moisture mass but appeared to increase with thickness. The burning time, defined as the duration of a visible flame near the leaf, was found to correlate roughly with leaf mass. Several types of correlations were made to describe ignition temperature and ignition time as a function of leaf thickness and mass of moisture.

It is difficult to capture the early signs of a forest fire at night using current visible-spectrum sensor technology. Infrared (IR) light sensors, on the other hand, can detect heat plumes expelled at the initial stages of a forest fire around the clock. Long-wave IR (LWIR) is commonly referred to as the “thermal infrared” region where thermal emissions are captured without the need of, or reflections from, external radiation sources. Mid‑wave IR (MWIR) bands lie between the “thermal infrared” and “reflected infrared” (i.e. short-wave IR) regions. Both LWIR and MWIR spectral regions are able to detect thermal radiation; however, they differ significantly in regards to their detection sensitivity of forest-fire heat plumes. Fires fueled by organic material (i.e. wood, leaves, etc.) primarily emit hot carbon dioxide (CO2) gas at combustion. Consequently, because CO2 is also present in the atmosphere, re-emission restricts the spectral transmittance and hence spectral radiance over a wide range of frequencies in the MWIR region. Moreover, as the distance between the detector and fire’s heat plume becomes greater, the additional CO2 introduced into the detection path leads to further attenuation of photon emittance. Since these absorption frequencies also lie within the response bandwidth of the MWIR sensor material, captured heat plume radiation manifests itself as a group of “flooded” or saturated pixels that exhibit very little dynamic behavior. Meanwhile, since the LWIR spectral region is not significantly affected by atmospheric gas absorption, its sensor is able to capture the forest fire’s heat plume thermal signature at far range without such complications. By exploiting the underlying spectral differences between LWIR and MWIR regions, this study aims to achieve early forest fire heat plume detection via direct identification of its dynamic characteristics whist concurrent attenuation of detected non-fire-related radiation. A land‑based, co‑located, cooled-LWIR/cooled-MWIR (CLWIR/CMWIR) detector camera is used to capture and normalize synchronized video from which sequential spatial-domain difference frames are generated. Processed frames allow for effective extraction of the heat plume’s “flickering” features, which are characteristic to the early stages of a forest fire. A multilayer perceptron (MLP) neural network classifier is trained with feature points generated from known target samples (i.e. supervised learning). Resulting detection performance is assessed via detection time, error metrics, computation time, and parameter variation. Results indicate that heat plumes expelled at the early stages of a forest fire can be identified with high sensitivity, low false alarm, and at a farther range than commercial detectors.

Early detection and mitigation of wildfires can reduce devastating property damage, firefighting costs, pollution, and loss of life. This thesis proposes the method of Principal Component Analysis (PCA) of images in the temporal domain to identify a smoke plume in wildfires. Temporal PCA is an effective motion detector, and spatial filtering of the output Principal Component images can segment the smoke plume region. The effective use of other image processing techniques to identify smoke plumes and heat plumes are compared. The best attributes of smoke plume detectors and heat plume detectors are evaluated for combination in an improved wildfire detection system. PCA of visible blue images at an image sampling rate of 2 seconds per image effectively exploits a smoke plume signal. PCA of infrared images is the fundamental technique for exploiting a heat plume signal. A system architecture is proposed for the implementation of image processing techniques. The real-world deployment and usability are described for this system.

No description available.