Em setembro de 2007 o grupo Gerdau concretizou a aquisição da siderúrgica americana Chaparral Steel, desembolsando para isso 4,2 bilhões de dólares. Para financiar esta compra, 93% do funding foi de capital de terceiros e participação de acionistas, obtidos através de operações de empréstimo, emissão de ações e de um Bond, com prazo médio total de 5 anos. As operações foram contratadas no terceiro trimestre de 2007, período no qual a crise do subprime começou a preocupar as empresas e investidores, com o reporte de contínuas perdas por mau-pagamento de hipotecas, principalmente nos Estados Unidos, afetando diversos produtos financeiros. Destaca-se nesta estruturação o fato dela ter sido premiada pela International Financing Review Awards como a melhor operação de empréstimo feita por uma empresa da América Latina em 2007 e também a questão de ser o maior valor desembolsado pelo grupo Gerdau em uma aquisição. Como um todo, a operação manteve a empresa dentro dos indicadores das melhores práticas do seu segmento e possibilitou criação de valor para os acionistas e stakeholders. / In September of 2007 the Gerdau group finalized the acquisition of the American steelmaker Chaparral Steel, with a disbursement of 4.2 billion US dollars. Only 7% of the financing of this purchase was cash, the remaining 93% was obtained through the emission of new shares, short-term and long-term debt, and a Bond, with a total average maturity of 5 years. All the operations were contracted on the third semester of 2007, when the subprime crises started to scare off companies and investors, with the continuous report of losses due to the financial structured products on the mortgages market, mainly in the US. The highlights of this structure are that it was awarded by International Financing Review Awards as the best Latin American Loan of 2007 and also, it was the most ever paid by the group in an acquisition. Last but not least, the operation kept the company in the range of the best practice ratios of its segment and allowed the creation of value for its shareholders and stakeholders.

Em setembro de 2007 o grupo Gerdau concretizou a aquisição da siderúrgica americana Chaparral Steel, desembolsando para isso 4,2 bilhões de dólares. Para financiar esta compra, 93% do funding foi de capital de terceiros e participação de acionistas, obtidos através de operações de empréstimo, emissão de ações e de um Bond, com prazo médio total de 5 anos. As operações foram contratadas no terceiro trimestre de 2007, período no qual a crise do subprime começou a preocupar as empresas e investidores, com o reporte de contínuas perdas por mau-pagamento de hipotecas, principalmente nos Estados Unidos, afetando diversos produtos financeiros. Destaca-se nesta estruturação o fato dela ter sido premiada pela International Financing Review Awards como a melhor operação de empréstimo feita por uma empresa da América Latina em 2007 e também a questão de ser o maior valor desembolsado pelo grupo Gerdau em uma aquisição. Como um todo, a operação manteve a empresa dentro dos indicadores das melhores práticas do seu segmento e possibilitou criação de valor para os acionistas e stakeholders. / In September of 2007 the Gerdau group finalized the acquisition of the American steelmaker Chaparral Steel, with a disbursement of 4.2 billion US dollars. Only 7% of the financing of this purchase was cash, the remaining 93% was obtained through the emission of new shares, short-term and long-term debt, and a Bond, with a total average maturity of 5 years. All the operations were contracted on the third semester of 2007, when the subprime crises started to scare off companies and investors, with the continuous report of losses due to the financial structured products on the mortgages market, mainly in the US. The highlights of this structure are that it was awarded by International Financing Review Awards as the best Latin American Loan of 2007 and also, it was the most ever paid by the group in an acquisition. Last but not least, the operation kept the company in the range of the best practice ratios of its segment and allowed the creation of value for its shareholders and stakeholders.

No description available.

Increased fire frequency, livestock grazing and other disturbances have caused type-conversion of native chaparral to non-native annual grasslands. Competition with non-native annual grasses hinders shrub establishment, presenting challenges in restoration. This study examined the feasibility of chaparral restoration in a Mediterranean-type climate, on a type-converted landscape in San Timoteo Canyon, Riverside County, California. The objectives of this study were to (1) compare the effectiveness of the broad-spectrum herbicide, glyphosate, to that of the grass specific herbicide, fluazifop, at eliminating non-native annual grasses; (2) compare the success of seeding or planting native seedlings as a means of restoration; (3) analyze the soil seed bank to determine if there was a relict native species seed bank on site; (4) test the field application of smoke-water as a technique to manipulate the soil’s native shrub seed-bank for restoration. A factorial design was utilized, with three replicates: four restoration treatments (no restoration, smoke-water application, seeding, and planting seedlings) across three herbicide treatments (a January glyphosate application followed by an early-March fluazifop treatment, an early-March fluazifop treatment only, and a control treatment with no herbicide). Glyphosate application followed by fluazifop application proved to be more effective at reducing non-native annual grasses and benefitted shrub establishment more effectively than the fluazifop and control treatments. The application of glyphosate in winter promoted shrub establishment and growth, and increased soil moisture, while preventing the springtime increase in grass cover that was seen in the control and fluazifop-only treatments. The four chaparral species that were planted (Adenostoma fasciculatum, Eriogonum fasciculatum, Quercus berberidifolia, Rhus ovata) did not behave similarly. No Quercus berberidifolia individuals survived. Eriogonum fasciculatum did not exhibit differences in survival in any herbicide treatments, but exhibited higher live plant canopy volume in plots that received glyphosate with fluazifop follow-up treatments. Adenostoma fasciculatum and Rhus ovata showed higher survival in plots that received glyphosate with fluazifop follow-up treatments; however, neither exhibited differences in live plant canopy volume between herbicide treatments. These results persisted until the end of the study, 14 months after planting. Seed application of seven species (Adenostoma fasciculatum, Artemisia californica, Eriogonum fasciculatum, Gutierrezia sarothrae, Quercus berberidifolia, Rhus aromatica, and Rhus ovata) was not successful at this study site. Seed bank analysis revealed that there was a high density of non-native seeds present, and that the relict native shrub seed bank was insufficient for restoration on this site. Smoke-water application at the study site proved to be ineffective at manipulating the soil seed bank, as no chaparral species emerged. Results from this study suggest that winter glyphosate application followed by a fluazifop application in a Mediterranean-type climate may benefit shrub re-establishment more than spring fluazifop-only treatments. Results indicate that winter herbicide treatment will eliminate competitive non-native annual grasses early in the growing season, resulting in increased soil moisture availability for chaparral shrubs to utilize. Winter glyphosate application, supplemented with the planting of seedlings, could be a successful technique to re-establish chaparral shrubs on type-converted slopes.

Thesis (M.S.)--Oregon State University, 2010. / Printout. Includes bibliographical references (leaves 45-54). Also available on the World Wide Web.

abstract: Species distribution modeling is used to study changes in biodiversity and species range shifts, two currently well-known manifestations of climate change. The focus of this study is to explore how distributions of suitable habitat might shift under climate change for shrub communities within the Santa Monica Mountains National Recreation Area (SMMNRA), through a comparison of community level to individual species level distribution modeling. Species level modeling is more commonly utilized, in part because community level modeling requires detailed community composition data that are not always available. However, community level modeling may better detect patterns in biodiversity. To examine the projected impact on suitable habitat in the study area, I used the MaxEnt modeling algorithm to create and evaluate species distribution models with presence only data for two future climate models at community and individual species levels. I contrasted the outcomes as a method to describe uncertainty in projected models. To derive a range of sensitivity outcomes I extracted probability frequency distributions for suitable habitat from raster grids for communities modeled directly as species groups and contrasted those with communities assembled from intersected individual species models. The intersected species models were more sensitive to climate change relative to the grouped community models. Suitable habitat in SMMNRA's bounds was projected to decline from about 30-90% for the intersected models and about 20-80% for the grouped models from its current state. Models generally captured floristic distinction between community types as drought tolerance. Overall the impact on drought tolerant communities, growing in hotter, drier habitat such as Coastal Sage Scrub, was predicted to be less than on communities growing in cooler, moister more interior habitat, such as some chaparral types. Of the two future climate change models, the wetter model projected less impact for most communities. These results help define risk exposure for communities and species in this conservation area and could be used by managers to focus vegetation monitoring tasks to detect early response to climate change. Increasingly hot and dry conditions could motivate opportunistic restoration projects for Coastal Sage Scrub, a threatened vegetation type in Southern California. / Dissertation/Thesis / M.A. Geography 2014

No description available.

Current operational wildland fire models are based on numerous correlations from experiments performed on dry (dead) fuel beds. However, experience has shown distinct differences in burning behaviors between dry and moist (live) fuels. To better understand these fundamental differences, an experiment was designed to use a flat-flame burner to simulate a moving fire front which heated and ignited a stationary, individual fuel sample. Samples included various U.S. species from the California chaparral, the intermountain west, and the southeastern regions. Temperature, mass, and video images were recorded throughout each experimental run from which numerous data values were obtained such as time to ignition, ignition temperature, flame height, time of flame duration, and mass release rates. Qualitative results showed various phenomena such as color change, bubbling, bursting, brand formation, and bending; these phenomena were species-dependent. Quantitative results showed differences in the ignition values (time, temperature, and mass) among species. It was observed that all moisture did not leave the interior of the sample at the time of ignition. Also, from the temperature history profiles, no plateau was observed at 100°C, but instead at 200-300°C. This indicates a need to treat evaporation differently than the classical combustion model. Samples were treated with solvents in attempt to extract the cuticle from the surface. These treated samples were compared to non-treated samples, though no significant combustion characteristics were observed. The time of color change for the treated samples varied significantly, indicating that the cuticle was indeed removed from the surface. Two-leaf configurations were developed and compared to determine combustion interactions between leaves. A second leaf was placed directly above the original leaf. Results showed that the time of flame duration of the upper leaf was significantly affected by the presence of the lower leaf. Causes for the prolonged flame were found to be the consumption of O2 by the lower leaf and the obstruction provided by the lower leaf, creating a wake effect which displaced hot gases from the flat-flame burner as well as entrained surrounding room temperature gas. A semi-physical model based on fluid dynamics and heat and mass transfer was developed that included the observed plateau at 200-300°C, rather than at 100°C; this was done for both the single- and two-leaf configurations. Another model using a statistical approach was produced which described the combustion of a bush that incorporated data obtained from the experimental results. Overall burning times and percentage of fuel consumption were obtained for various fuel loadings using this statistical model.

We explored the seasonal factors that might play a role in triggering germination of Dendromecon rigidaand Ehrendorferia chrysantha.D. rigida and E. chrysantha have been found difficult to germinate using common greenhouse techniques, Keeley and Fotheringham successfully germinated both species after storing their seeds in the field over a year and treating them with smoke. Identifying the specific seasonally changing factors that stimulated germination could have implications for understanding germination requirements for these and other hard-to-germinate chaparral species. Dendromecon rigidaand Ehrendorferia chrysanthaare part of the Papaveraceae family and both are found in the chaparral environment in Southern California. Both species are known to increase in numbers after fire events. Both are believed to have morphophysiological dormancy based on their miniscule embryo and increase in seedling presence after fire events. Climate within the chaparral environment consists of hot, dry summers and cold, wet winters. Storing seeds of D. rigidaand E. chrysantha in the field over winter and spring months resulted in increasing germination for D. rigida seeds that were imbibed in smoke-water. Germination of D. rigidaseeds occurred within six weeks and no further germination was noted beyond that. Ehrendorferia chrysanthaseeds failed to germinate in the field. Lab studies tested effects of stratification at different temperatures (5ºC, 10ºC, 18ºC, 25ºC and 30ºC), stratification for different durations (0, 2, 4, 8, and 12 weeks), heat-shock, and fluctuating moisture and temperature conditions on a weekly time scale, on germination of both species. Of all these treatments the only combination that was effective in germinating seeds of D. rigidaand E. chrysanthawas warm stratification at 30ºC for 8 weeks following smoke-water imbibition. Under these conditions seeds of D. rigidaand E. chrysanthagerminated to 10% and 9.3%, respectively. Further studies on D. rigidaindicated a stratification temperature optimum between 30-40ºC with germination increasing with lack of light. These tested conditions corresponded to the daily peak soil temperatures measured at shallow depth in an area of chaparral inhabited by D. rigida. The period immediately after the first rain event after a fire may provide the chemical cues and warm stratification required to germinate buried seeds in this species.

From the Proceedings of the 1972 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - May 5-6, 1972, Prescott, Arizona / Chaparral covers 4 million acres in Arizona. There is interest in determining how much these lands contribute to surface water supply, and how this contribution could be changed by conversion of chaparral cover to grass or grass forb. Results from treatment in the Whitespar watersheds are interpreted. Live oak and true mountain mahogany dominate the study area, which averages 22.7 inches of annual precipitation. Whitespar B watershed was converted to grasses in 1967, and litter was not disturbed. The 246 acre watershed produced more streamflow than the untreated, 303-acre control which tended to remain intermittent. Prior to treatment, streamflow in both watersheds was quite well synchronized. Watershed b has since had continual flow. Winter flows contribute about 77 percent of the increased streamflow volume. The degree of effect is still under study, but a new rainfall-runoff relationship for the treated watershed is necessitated.