983 resultados para Paraiba Valley
Resumo:
The objective of the study presented in this report was to document the launch of the Iowa River Bridge and to monitor and evaluate the structural performance of the bridge superstructure and substructure during the launch. The Iowa Department of Transportation used an incremental launching method, which is relatively unique for steel I-girder bridges, to construct the Iowa River Bridge over an environmentally sensitive river valley in central Iowa. The bridge was designed as two separate roadways consisting of four steel plate girders each that are approximately 11 ft deep and span approximately 301 ft each over five spans. The concrete bridge deck was not placed until after both roadways had been launched. One of the most significant monitoring and evaluation observations related to the superstructure was that the bottom flange (and associated web region) was subjected to extremely large stresses during the crossing of launch rollers. Regarding the substructure performance, the column stresses did not exceed reasonable design limits during the daylong launches. The scope of the study did not allow adequate quantification of the measured applied launch forces at the piers. Future proposed esearch should provide an opportunity to address this. The overall experimental performance of the bridge during the launch was compared with the predicted design performance. In general, the substructure design, girder contact stress, and total launching force assumptions correlated well with the experimental results. The design assumptions for total axial force in crossframe members, on the other hand, differed from the experimental results by as much as 300%.
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Six stands located on different land forms in mixed old-growth Nothofagus forests in the Matiri Valley (northwest of South Island. New Zealand) were sampled to examine the effects of two recent large earthquakes on tree establishment and tree-ring growth, and how these varied across land forms. 50 trees were cor ed in each stand to determine age structure and the cores were cross-dated to precisely date unusual periods of radial growth. The 1968 earthquake (M = 7.1, epicentre 35 km from the study area) had no discernible impact on the sampled stands. The impact of the 1929 earthquake (M = 7.7, epicentre 20 kin from the study area) varied between stands, depending on whether or not they had been damaged by soil or rock movement. In all stands, the age structures showed a pulse of N. fusca establishment following the 1929 earthquake, with this species dominating establishment in large gaps created by landslides. Smaller gaps, created by branch or tree death, were closed by both N. fusca and N. menziesii. The long period of releases (1929-1945) indicates that direct earthquake damage was not the only cause of tree death, and that many trees died subsequently most likely of pathogen attack or a drought in the early 1930s. The impacts of the 1929 earthquake are compared to a storm in 1905 and a drought in 1974-1978 which also affected forests in the region. Our results confirm that earthquakes are an important factor driving forest dynamics in this tectonically active region, and that the diversity of earthquake impacts is a major source of heterogeneity in forest structure and regeneration.
Resumo:
At one time, Clear Creek lived up to its name. Originally set among the prairie and oak savannah of the Iowa River valley, legend has it that early settler and Johnson County sheriff Samuel Trowbridge gave the creek its name because of its pristine waters. However, the stream’s natural protections began to weaken as more settlers moved into Iowa. Over time, the prairie disappeared, livestock trampled streambanks, the creek was dredged and straightened, wetlands were drained and urban areas began to take their toll.
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OBJECTIVE Assessing the adequacy of knowledge, attitude and practice of women regarding male and female condoms as STI/HIV preventive measures. METHOD An evaluative Knowledge, Attitude and Practice (KAP) household survey with a quantitative approach, involving 300 women. Data collection took place between June and August 2013, in an informal urban settlement within the municipality of João Pessoa, Paraiba, Northeast Brazil. RESULTS Regarding the male condom, most women showed inadequate knowledge and practice, and an adequate attitude. Regarding the female condom, knowledge, attitude and practice variables were unsatisfactory. Significant associations between knowledge/religious orientation and attitude/education regarding the male condom were observed. CONCLUSION A multidisciplinary team should be committed to the development of educational practices as care promotion tools in order to improve adherence of condom use.
Resumo:
Four standard radiation qualities (from RQA 3 to RQA 9) were used to compare the imaging performance of a computed radiography (CR) system (general purpose and high resolution phosphor plates of a Kodak CR 9000 system), a selenium-based direct flat panel detector (Kodak Direct View DR 9000), and a conventional screen-film system (Kodak T-MAT L/RA film with a 3M Trimax Regular screen of speed 400) in conventional radiography. Reference exposure levels were chosen according to the manufacturer's recommendations to be representative of clinical practice (exposure index of 1700 for digital systems and a film optical density of 1.4). With the exception of the RQA 3 beam quality, the exposure levels needed to produce a mean digital signal of 1700 were higher than those needed to obtain a mean film optical density of 1.4. In spite of intense developments in the field of digital detectors, screen-film systems are still very efficient detectors for most of the beam qualities used in radiology. An important outcome of this study is the behavior of the detective quantum efficiency of the digital radiography (DR) system as a function of beam energy. The practice of users to increase beam energy when switching from a screen-film system to a CR system, in order to improve the compromise between patient dose and image quality, might not be appropriate when switching from screen-film to selenium-based DR systems.
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Crans-Montana-Sierre is a tourist area locateci in Rhone valley in central Valais, cha-racterized by dry climate and scarce summer precipitations. More than other regions in Switzerland, this area has suffered the effects of the drought (heat wave) that affec¬ted all Western Europe during summer 2003. In the future, climate change together with societal and economic development will signicantly modify the water need of the region and, consequently, may increase the potential conflicts of interest. Within a long term planning strategy, decision-makers require precise information about the current amount of water needed in the region, with particular attention to temporal and spatial concentration, and the forecasted amount for 2050. This work therefore aims at estimating the variation of the water demand by taking into account the influence of climate change (CH2011) and socio-economic scenarios, developed in cooperation with the competent authorities. This thesis, whose aim is to study the water management and water uses is a core part of the MontanAqua project "Water management in times of scarcity and global change" mainly because of its interdisciplinary topic at the interface between water resources, land development and the socio-political structure. Results show that socio-economic development by 2050 could have a greater impact than expected climate changes (CH2011, A1B scenarios) for the same time horizon for water demand. Demography, spatial planning, tourism and economic development are just some of the factors that could significantly affect the water consumption of the Crans-Montana-Sierre region. Compared with the future water resources available, the maximal water demand forecasted by the socio-economic scenarios developed within the project MontanAqua, could not always be satisfied. This issue, like extreme climate phenomena (as it was the summer drought occurred in 2003 or in April / May 2011), could be mitigated adopting regional management policies relating to a more rational water use and preventive storage of water resource. - Crans-Montana-Sierre est une région touristique située dans la vallée du Rhône; dans le Valais central, qui se caractérise par un climat relativement pauvre en précipitations et qui plus que d'autres a subi les effets de la sécheresse qui a touché l'Europe occidentale durant l'été 2003. À l'avenir, les changements climatiques ainsi que le développement socio-économique modifieront de manière significative les besoins en eau de la région, ce qui risque de faire augmenter les rivalités d'usage concernant cette ressource. Afin de jouer à l'avance, les décideurs ont besoin d'informations précises sur la quantité d'eau nécessaire à la région, avec une attention particulière à sa concentration temporelle et spatiale, à l'heure actuelle et à l'horizon 2050. Ce travail vise donc à estimer la variation de la demande en eau en tenant compte de l'influence des changements climatiques (CH2011) et des scénarios socio-économiques, élaborés en collaboration avec les autorités compétentes. Cette thèse, qui met l'accent sur les usages de l'eau fait partie du projet Montan Aqua « Gestion de l'eau en temps de pénurie et de changement global », est à l'intersection entre les ressources hydriques, l'aménagement du territoire et son organisation socio-politique, fait qui la met, non pas par son importance, mais par son emplacement et ses interconnexions, au coeur de cette recherche. Les résultats obtenus montrent comment les développements socio-économiques d'ici à 2050 ont un impact potentiellement plus important que les changements climatiques prévus par les scénarios AlB de CH2011 pour le même horizon temporel sur la demande en eau. Démographie, aménagement du territoire et contexte économico-touristique, ne sont que quelques-uns des facteurs qui ont la capacité d'agir significativement sur les usages de l'eau en ce qui concerne les aspects qualitatif et quantitatif de la région de Crans-Montana-Sierre. Par rapport aux ressources en eau disponibles à l'avenir, la demande maximale d'eau prévue par les scénarios socio-économiques développés au sein du projet MontanAqua risque de ne pas être toujours satisfaite. Ce danger et la manifestation de phénomènes climatiques extrêmes, comme la sécheresse estivale survenue en 2003 ou celle d'avril/mai 2011, ne pourront être atténués que par l'adoption de politiques de gestion à l'échelle régionale favorisant une utilisation plus rationnelle et un stockage préventif de la ressource en eau.
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Three sibling species of shrews, the common shrew (Sorex araneus), the Valais shrew (S. antinorii) and the Jersey shrew (S. coronatus) are morphologically similar. Different techniques based on karyorypes, morphology, biochemistry and genetic markers have been developed to identify individuals from these taxa. In this paper, we have used multiple microsatellite markers (L13, L14 and L99) to identify 55 dead animals coming from the Tarentaise Valley in France. As some individuals showed an unclear pattern with loci previously thought to be diagnostic (Lugon-Moulin et al. 2000), we have used morphologic measurements (Hausser et al. 1991) to confirm the status of these animals. This analysis clearly showed the limitations of the use of genetic diagnostic markers that have been designed in local populations and then applied to a wider scale. Even if these markers have great advantages over other techniques (i.e. simple to use and do not require samples from living animals), they should always be used with caution. There is always a risk of a locus not being diagnostic in the sampling region or in finding individuals with hybrid genotypes. Additional genetic markers should then be used, simultaneously with other identification techniques, to be sure of the status of the individuals.
Reorganization of a deeply incised drainage: role of deformation, sedimentation and groundwater flow
Resumo:
Deeply incised drainage networks are thought to be robust and not easily modified, and are commonly used as passive markers of horizontal strain. Yet, reorganizations (rearrangements) appear in the geologic record. We provide field evidence of the reorganization of a Miocene drainage network in response to strike-slip and vertical displacements in Guatemala. The drainage was deeply incised into a 50-km-wide orogen located along the North America-Caribbean plate boundary. It rearranged twice, first during the Late Miocene in response to transpressional uplift along the Polochic fault, and again in the Quaternary in response to transtensional uplift along secondary faults. The pattern of reorganization resembles that produced by the tectonic defeat of rivers that cross growing tectonic structures. Compilation of remote sensing data, field mapping, sediment provenance study, grain-size analysis and Ar(40)/Ar(39) dating from paleovalleys and their fill reveals that the classic mechanisms of river diversion, such as river avulsion over bedrock, or capture driven by surface runoff, are not sufficient to produce the observed diversions. The sites of diversion coincide spatially with limestone belts and reactivated fault zones, suggesting that solution-triggered or deformation-triggered permeability have helped breaching of interfluves. The diversions are also related temporally and spatially to the accumulation of sediment fills in the valleys, upstream of the rising structures. We infer that the breaching of the interfluves was achieved by headward erosion along tributaries fed by groundwater flow tracking from the valleys soon to be captured. Fault zones and limestone belts provided the pathways, and the aquifers occupying the valley fills provided the head pressure that enhanced groundwater circulation. The defeat of rivers crossing the rising structures results essentially from the tectonically enhanced activation of groundwater flow between catchments.