939 resultados para Build-Up Back To Back LSB, Cold-Formed Steel Structures, Lateral Distortional Buckling


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Bioplastics are polymers (such as polyesters) produced from bacterial fermentations that are biodegradable and nonhazardous. They are produced by a wide variety of bacteria and are made only when stress conditions allow, such as when nutrient levels are low, more specifically levels of nitrogen and oxygen. These stress conditions cause certain bacteria to build up excess carbon deposits as energy reserves in the form of polyhydroxyalkanoates (PHAs). PHAs can be extracted and formed into actual plastic with the same strength of conventional, synthetic-based plastics without the need to rely on foreign petroleum. The overall goal of this project was to select for a bacteria that could grow on sugars found in the lignocellulosic biomass, and get the bacteria to produce PHAs and peptidoglycan. Once this was accomplished the goal was to extract PHAs and peptidoglycan in order to make a stronger more rigid plastic, by combing them into a co-polymer. The individual goals of this project were to: (1) Select and screen bacteria that are capable of producing PHAs by utilizing the carbon/energy sources found in lignocellulosic biomass; (2) Maximize the utilization of those sugars present in woody biomass in order to produce optimal levels of PHAs. (3) Use room temperature ionic liquids (RTILs) in order to separate the cell membrane and peptidoglycan, allowing for better extraction of PHAs and more intact peptidoglycan. B. megaterium a Gram-positive PHA-producing bacterium was selected for study in this project. It was grown on a variety of different substrates in order to maximize both its growth and production of PHAs. The optimal conditions were found to be 30°C, pH 6.0 and sugar concentration of either 30g/L glucose or xylose. After optimal growth was obtained, both RTILs and enzymatic treatments were used to break the cell wall, in order to extract the PHAs, and peptidoglycan. PHAs and peptidoglycan were successfully extracted from the cell, and will be used in the future to create a new stronger co-polymer. Peptidoglycan recovery yield was 16% of the cells’ dry weight.

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A detailed characterization of air quality in the megacity of Paris (France) during two 1-month intensive campaigns and from additional 1-year observations revealed that about 70% of the urban background fine particulate matter (PM) is transported on average into the megacity from upwind regions. This dominant influence of regional sources was confirmed by in situ measurements during short intensive and longer-term campaigns, aerosol optical depth (AOD) measurements from ENVISAT, and modeling results from PMCAMx and CHIMERE chemistry transport models. While advection of sulfate is well documented for other megacities, there was surprisingly high contribution from long-range transport for both nitrate and organic aerosol. The origin of organic PM was investigated by comprehensive analysis of aerosol mass spectrometer (AMS), radiocarbon and tracer measurements during two intensive campaigns. Primary fossil fuel combustion emissions constituted less than 20%in winter and 40%in summer of carbonaceous fine PM, unexpectedly small for a megacity. Cooking activities and, during winter, residential wood burning are the major primary organic PM sources. This analysis suggests that the major part of secondary organic aerosol is of modern origin, i.e., from biogenic precursors and from wood burning. Black carbon concentrations are on the lower end of values encountered in megacities worldwide, but still represent an issue for air quality. These comparatively low air pollution levels are due to a combination of low emissions per inhabitant, flat terrain, and a meteorology that is in general not conducive to local pollution build-up. This revised picture of a megacity only being partially responsible for its own average and peak PM levels has important implications for air pollution regulation policies.

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The Astronomical Institute of the University of Bern (AIUB) is conducting several search campaigns for space debris using optical sensors. The debris objects are discovered during systematic survey observations. In general, the result of a discovery consists in only a short observation arc, or tracklet, which is used to perform a first orbit determination in order to be able to observe t he object again in subsequent follow-up observations. The additional observations are used in the orbit improvement process to obtain accurate orbits to be included in a catalogue. In order to obtain the most accurate orbit within the time available it is necessary to optimize the follow-up observations strategy. In this paper an in‐depth study, using simulations and covariance analysis, is performed to identify the optimal sequence of follow-up observations to obtain the most accurate orbit propagation to be used for the space debris catalogue maintenance. The main factors that determine the accuracy of the results of an orbit determination/improvement process are: tracklet length, number of observations, type of orbit, astrometric error of the measurements, time interval between tracklets, and the relative position of the object along its orbit with respect to the observing station. The main aim of the covariance analysis is to optimize the follow-up strategy as a function of the object-observer geometry, the interval between follow-up observations and the shape of the orbit. This an alysis can be applied to every orbital regime but particular attention was dedicated to geostationary, Molniya, and geostationary transfer orbits. Finally the case with more than two follow-up observations and the influence of a second observing station are also analyzed.

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Soils are fundamental to ensuring water, energy and food security. Within the context of sus- tainable food production, it is important to share knowledge on existing and emerging tech- nologies that support land and soil monitoring. Technologies, such as remote sensing, mobile soil testing, and digital soil mapping, have the potential to identify degraded and non- /little-responsive soils, and may also provide a basis for programmes targeting the protection and rehabilitation of soils. In the absence of such information, crop production assessments are often not based on the spatio-temporal variability in soil characteristics. In addition, uncertain- ties in soil information systems are notable and build up when predictions are used for monitor- ing soil properties or biophysical modelling. Consequently, interpretations of model-based results have to be done cautiously. As such they provide a scientific, but not always manage- able, basis for farmers and/or policymakers. In general, the key incentives for stakeholders to aim for sustainable management of soils and more resilient food systems are complex at farm as well as higher levels. The same is true of drivers of soil degradation. The decision- making process aimed at sustainable soil management, be that at farm or higher level, also in- volves other goals and objectives valued by stakeholders, e.g. land governance, improved envi- ronmental quality, climate change adaptation and mitigation etc. In this dialogue session we will share ideas on recent developments in the discourse on soils, their functions and the role of soil and land information in enhancing food system resilience.

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Bargaining is the building block of many economic interactions, ranging from bilateral to multilateral encounters and from situations in which the actors are individuals to negotiations between firms or countries. In all these settings, economists have been intrigued for a long time by the fact that some projects, trades or agreements are not realized even though they are mutually beneficial. On the one hand, this has been explained by incomplete information. A firm may not be willing to offer a wage that is acceptable to a qualified worker, because it knows that there are also unqualified workers and cannot distinguish between the two types. This phenomenon is known as adverse selection. On the other hand, it has been argued that even with complete information, the presence of externalities may impede efficient outcomes. To see this, consider the example of climate change. If a subset of countries agrees to curb emissions, non-participant regions benefit from the signatories’ efforts without incurring costs. These free riding opportunities give rise to incentives to strategically improve ones bargaining power that work against the formation of a global agreement. This thesis is concerned with extending our understanding of both factors, adverse selection and externalities. The findings are based on empirical evidence from original laboratory experiments as well as game theoretic modeling. On a very general note, it is demonstrated that the institutions through which agents interact matter to a large extent. Insights are provided about which institutions we should expect to perform better than others, at least in terms of aggregate welfare. Chapters 1 and 2 focus on the problem of adverse selection. Effective operation of markets and other institutions often depends on good information transmission properties. In terms of the example introduced above, a firm is only willing to offer high wages if it receives enough positive signals about the worker’s quality during the application and wage bargaining process. In Chapter 1, it will be shown that repeated interaction coupled with time costs facilitates information transmission. By making the wage bargaining process costly for the worker, the firm is able to obtain more accurate information about the worker’s type. The cost could be pure time cost from delaying agreement or cost of effort arising from a multi-step interviewing process. In Chapter 2, I abstract from time cost and show that communication can play a similar role. The simple fact that a worker states to be of high quality may be informative. In Chapter 3, the focus is on a different source of inefficiency. Agents strive for bargaining power and thus may be motivated by incentives that are at odds with the socially efficient outcome. I have already mentioned the example of climate change. Other examples are coalitions within committees that are formed to secure voting power to block outcomes or groups that commit to different technological standards although a single standard would be optimal (e.g. the format war between HD and BlueRay). It will be shown that such inefficiencies are directly linked to the presence of externalities and a certain degree of irreversibility in actions. I now discuss the three articles in more detail. In Chapter 1, Olivier Bochet and I study a simple bilateral bargaining institution that eliminates trade failures arising from incomplete information. In this setting, a buyer makes offers to a seller in order to acquire a good. Whenever an offer is rejected by the seller, the buyer may submit a further offer. Bargaining is costly, because both parties suffer a (small) time cost after any rejection. The difficulties arise, because the good can be of low or high quality and the quality of the good is only known to the seller. Indeed, without the possibility to make repeated offers, it is too risky for the buyer to offer prices that allow for trade of high quality goods. When allowing for repeated offers, however, at equilibrium both types of goods trade with probability one. We provide an experimental test of these predictions. Buyers gather information about sellers using specific price offers and rates of trade are high, much as the model’s qualitative predictions. We also observe a persistent over-delay before trade occurs, and this mitigates efficiency substantially. Possible channels for over-delay are identified in the form of two behavioral assumptions missing from the standard model, loss aversion (buyers) and haggling (sellers), which reconcile the data with the theoretical predictions. Chapter 2 also studies adverse selection, but interaction between buyers and sellers now takes place within a market rather than isolated pairs. Remarkably, in a market it suffices to let agents communicate in a very simple manner to mitigate trade failures. The key insight is that better informed agents (sellers) are willing to truthfully reveal their private information, because by doing so they are able to reduce search frictions and attract more buyers. Behavior observed in the experimental sessions closely follows the theoretical predictions. As a consequence, costless and non-binding communication (cheap talk) significantly raises rates of trade and welfare. Previous experiments have documented that cheap talk alleviates inefficiencies due to asymmetric information. These findings are explained by pro-social preferences and lie aversion. I use appropriate control treatments to show that such consideration play only a minor role in our market. Instead, the experiment highlights the ability to organize markets as a new channel through which communication can facilitate trade in the presence of private information. In Chapter 3, I theoretically explore coalition formation via multilateral bargaining under complete information. The environment studied is extremely rich in the sense that the model allows for all kinds of externalities. This is achieved by using so-called partition functions, which pin down a coalitional worth for each possible coalition in each possible coalition structure. It is found that although binding agreements can be written, efficiency is not guaranteed, because the negotiation process is inherently non-cooperative. The prospects of cooperation are shown to crucially depend on i) the degree to which players can renegotiate and gradually build up agreements and ii) the absence of a certain type of externalities that can loosely be described as incentives to free ride. Moreover, the willingness to concede bargaining power is identified as a novel reason for gradualism. Another key contribution of the study is that it identifies a strong connection between the Core, one of the most important concepts in cooperative game theory, and the set of environments for which efficiency is attained even without renegotiation.

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BACKGROUND After the introduction of instruments for benchmarking, certification and a national guideline for acute pain management, the aim of this study was to describe the current structure, processes and quality of German acute pain services (APS). METHODS All directors of German departments of anaesthesiology were invited to complete a postal questionnaire on structures und processes of acute pain management. The survey asked for staff, techniques and quality criteria, which enabled a comparison to previous data from 1999 and surveys from other countries. RESULTS Four hundred and eight (46%) questionnaires were returned. APS have increased considerably and are now available in 81% of the hospitals, mainly anaesthesia based. However, only 45% fulfilled the minimum quality criteria, such as the assignment of personnel, the organization of patient care during nights and weekends, written protocols for postoperative pain management, regular assessments and documenting pain scores. Staff resources varied considerably, but increased compared to 1999. Two daily rounds were performed in 71%, either by physicians and nurses (42%), by physicians only (25%) or by supervised nurses (31%). Most personnel assigned to the APS shared this work along with other duties. Only 53% of the hospitals had an integrated rotation for training their specialty trainees. CONCLUSIONS The availability of APS in Germany and other countries has increased over the last decade; however, the quality of nearly half of the APS is questionable. Against the disillusioning background of recently reported unfavourable pain-related patient outcomes, the structures, organization and quality of APS should be revisited.

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No single mechanism can account for the full amplitude of past atmospheric carbon dioxide (CO2) concentration variability over glacial–interglacial cycles. A build-up of carbon in the deep ocean has been shown to have occurred during the Last Glacial Maximum. However, the mechanisms responsible for the release of the deeply sequestered carbon to the atmosphere at deglaciation, and the relative importance of deep ocean sequestration in regulating millennial-timescale variations in atmospheric CO2 concentration before the Last Glacial Maximum, have remained unclear. Here we present sedimentary redox-sensitive trace metal records from the Antarctic Zone of the Southern Ocean that provide a reconstruction of transient changes in deep ocean oxygenation and, by inference, respired carbon storage throughout the last glacial cycle. Our data suggest that respired carbon was removed from the abyssal Southern Ocean during the Northern Hemisphere cold phases of the deglaciation, when atmospheric CO2 concentration increased rapidly, reflecting—at least in part— a combination of dwindling iron fertilization by dust and enhanced deep ocean ventilation. Furthermore, our records show that the observed covariation between atmospheric CO2 concentration and abyssal Southern Ocean oxygenation was maintained throughout most of the past 80,000 years. This suggests that on millennial timescales deep ocean circulation and iron fertilization in the Southern Ocean played a consistent role in modifying atmospheric CO2 concentration.

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STUDY DESIGN Retrospective analysis of prospectively collected clinical data. OBJECTIVE To assess the long-term outcome of patients with monosegmental L4/5 degenerative spondylolisthesis treated with the dynamic Dynesys device. SUMMARY OF BACKGROUND DATA The Dynesys system has been used as a semirigid, lumbar dorsal pedicular stabilization device since 1994. Good short-term results have been reported, but little is known about the long-term outcome after treatment for degenerative spondylolisthesis at the L4/5 level. METHODS A total of 39 consecutive patients with symptomatic degenerative lumbar spondylolisthesis at the L4/5 level were treated with bilateral decompression and Dynesys instrumentation. At a mean follow-up of 7.2 years (range, 5.0-11.2 y), they underwent clinical and radiographic evaluation and quality of life assessment. RESULTS At final follow-up, back pain improved in 89% and leg pain improved in 86% of patients compared with preoperative status. Eighty-three percent of patients reported global subjective improvement. Ninety-two percent would undergo the surgery again. Eight patients (21%) required further surgery because of symptomatic adjacent segment disease (6 cases), late-onset infection (1 case), and screw breakage (1 case). In 9 cases, radiologic progression of spondylolisthesis at the operated segment was found. Seventy-four percent of operated segments showed limited flexion-extension range of <4 degrees. Adjacent segment pathology, although without clinical correlation, was diagnosed at the L5/S1 (17.9%) and L3/4 (28.2%) segments. In 4 cases, asymptomatic screw loosening was observed. CONCLUSIONS Monosegmental Dynesys instrumentation of degenerative spondylolisthesis at L4/5 shows good long-term results. The rate of secondary surgeries is comparable to other dorsal instrumentation devices. Residual range of motion in the stabilized segment is reduced, and the rate of radiologic and symptomatic adjacent segment degeneration is low. Patient satisfaction is high. Dynesys stabilization of symptomatic L4/5 degenerative spondylolisthesis is a possible alternative to other stabilization devices.

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The purpose of this culminating experience was to investigate the relationships between healthcare utilization, insurance coverage, and socioeconomic characteristics of children with asthma along the Texas-Mexico Border. A secondary data analysis was conducted on cross-sectional data from the Texas Child Asthma Call-back Survey, a follow-up survey to the random digit dialed Behavior Risk Factor Surveillance Study (BRFSS) conducted between 2006-2009 ( n = 556 adults living in households with a child with asthma).^ The proportion of Hispanic children with asthma in Border areas of Texas was more than twice that of non-Border areas (84.8% vs. 28.8%). Parents in Border areas were less likely to have their own health insurance (OR = 0.251, 95% C.I. = 0.117-0.540) and less likely to complete the survey in English than Spanish (OR = 0.251 95% C.I. = 0.117-0.540) than parents in non-Border areas. No significant socio-economic or health care utilization differences were noted between Hispanic children living in Border areas compared to Hispanic children living in non-Border areas. Children with asthma along the Texas-Mexico Border, regardless of ethnicity and language, have insurance coverage rates, reported cost barriers to care, symptom management, and medication usage patterns similar to those in non-Border areas. When compared to English-speakers, Spanish-speaking parents in Texas as a whole are far less likely to be taught what to do during an asthma attack (50.2% vs. 78.6%).^ Language preference, rather than ethnicity or geographical residence, played a larger role on childhood asthma-related health disparities for children in Texas. Spanish-speaking parents in are less likely to receive adequate asthma self-management education. Investigating the effects of Hispanic acculturation rates and incongruent parent-child health insurance coverage may provide better insight into the health disparities of children along the Texas-Mexico Border.^

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This chemical and petrologic study of rocks from Site 448 on the Palau-Kyushu Ridge is designed to answer some fundamental questions concerning the volcanic origin of remnant island arcs. According to the reconstruction of the Western Pacific prior to about 45 m.y. ago (Hilde et al., 1977), the site of the Palau-Kyushu Ridge was a major transform fault. From a synthesis of existing geological and geophysical data (R. Scott et al., this volume), it appears that the ridge originated by subduction of the Pacific plate under the West Philippine Basin. Thus the Palau-Kyushu Ridge should be a prime example of both initial volcanism of an incipient arc formed by interaction of oceanic lithospheric plates and remnant-arc volcanic evolution. The Palau-Kyushu Ridge was an active island arc from about 42 to 30 m.y. ago, after which initiation of back-arc spreading formed the Parece Vela Basin (R. Scott et al., this volume; Karig, 1975a). This spreading left the western portion of the ridge as a remnant arc that separates the West Philippine Basin from the Parece Vela Basin. In spite of numerous oceanographic expeditions to the Philippine Sea, including the two previous DSDP Legs 6 and 31 (Fischer, Heezen et al., 1971; Karig, Ingle et al., 1975), and even though the origins of inter-arc basins have been linked by various hypotheses to that of remnant island arcs (Karig, 1971, 1972, 1975a, and 1975b; Gill, 1976; Uyeda and Ben-Avraham, 1972; Hilde et al., 1977), very little hard data are available on inactive remnant arcs.

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Se propone la descripción y el análisis del empleo de la transmisión oral en la narrativa española actual como un recurso para configurar la memoria de la Guerra Civil española y del franquismo. Para ello se atendió especialmente a las estrategias que intervienen en la representación de la oralidad en relación con los diálogos y los relatos orales, entre otros procedimientos a través de los cuales se transmite el pasado traumático dentro de la ficción. Ha sido analizada la representación de la oralidad en la producción narrativa ficcional de diversos autores españoles de finales del siglo XX y comienzos del siglo XXI que han abordado la temática de la Guerra Civil en una situación particular en cuanto al surgimiento de replanteos y debates acerca del tratamiento del conflicto bélico. Los objetivos generales que guiaron el trabajo han sido indagar la presencia y la función de la transmisión oral en la literatura, profundizar el estudio de la oralidad como voz emergente de colectivos sociales desplazados y analizar la funcionalidad del empleo de la oralidad en textos representativos de la narrativa española contemporánea. A su vez, más específicamente, se propuso profundizar en el estudio de la ficcionalización de la transmisión oral como un artificio para la construcción de la memoria en la narrativa española actual, vincular las posibilidades de transmisión de la historia de la Guerra Civil española con medios propios de la historia oral en la literatura -especialmente en la novela-, problematizar determinadas perspectivas sobre el testimonio en la medida en que son literaturizadas para una concepción de la memoria de la Guerra Civil, de la posguerra y de la dictadura, y estudiar algunas miradas contemporáneas acerca de la Guerra Civil y del franquismo desde el campo de la narrativa como un correlato de ciertos reclamos sociales de la actualidad respecto del pasado reciente. Para esto fueron analizadas diversas propuestas que surgieron esencialmente desde la literatura -con algún detenimiento en un texto fílmico- para abordar el pasado traumático y se consideraron las técnicas de transmisión empleadas para la narración ficcional de aspectos largamente silenciados por la historia oficial. El corpus central de textos literarios ha quedado conformado por O lapis do carpinteiro y Os libros arden mal, de Manuel Rivas, Guárdame bajo tierra, de Ramón Saizarbitoria, Soldados de Salamina, de Javier Cercas, Home sen nome, de Suso de Toro, y Mala gente que camina, de Benjamín Prado. Como corpus complementario, se tornó pertinente incorporar un capítulo que articula un texto fílmico (Muerte en El Valle, de Christina Hardt) con un texto literario (Las esquinas del aire. En busca de Ana María Martínez Sagi, de Juan Manuel de Prada). Esto, que en principio puede parecer un apartamiento del corpus central, favoreció el análisis del tratamiento del testimonio desde la estetización de un texto fílmico o literario. Al realizar la selección, se estudiaron, junto con autores que escriben y publican en castellano, algunos textos escritos originariamente en lenguas minorizadas (gallego y euskera)

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Se propone la descripción y el análisis del empleo de la transmisión oral en la narrativa española actual como un recurso para configurar la memoria de la Guerra Civil española y del franquismo. Para ello se atendió especialmente a las estrategias que intervienen en la representación de la oralidad en relación con los diálogos y los relatos orales, entre otros procedimientos a través de los cuales se transmite el pasado traumático dentro de la ficción. Ha sido analizada la representación de la oralidad en la producción narrativa ficcional de diversos autores españoles de finales del siglo XX y comienzos del siglo XXI que han abordado la temática de la Guerra Civil en una situación particular en cuanto al surgimiento de replanteos y debates acerca del tratamiento del conflicto bélico. Los objetivos generales que guiaron el trabajo han sido indagar la presencia y la función de la transmisión oral en la literatura, profundizar el estudio de la oralidad como voz emergente de colectivos sociales desplazados y analizar la funcionalidad del empleo de la oralidad en textos representativos de la narrativa española contemporánea. A su vez, más específicamente, se propuso profundizar en el estudio de la ficcionalización de la transmisión oral como un artificio para la construcción de la memoria en la narrativa española actual, vincular las posibilidades de transmisión de la historia de la Guerra Civil española con medios propios de la historia oral en la literatura -especialmente en la novela-, problematizar determinadas perspectivas sobre el testimonio en la medida en que son literaturizadas para una concepción de la memoria de la Guerra Civil, de la posguerra y de la dictadura, y estudiar algunas miradas contemporáneas acerca de la Guerra Civil y del franquismo desde el campo de la narrativa como un correlato de ciertos reclamos sociales de la actualidad respecto del pasado reciente. Para esto fueron analizadas diversas propuestas que surgieron esencialmente desde la literatura -con algún detenimiento en un texto fílmico- para abordar el pasado traumático y se consideraron las técnicas de transmisión empleadas para la narración ficcional de aspectos largamente silenciados por la historia oficial. El corpus central de textos literarios ha quedado conformado por O lapis do carpinteiro y Os libros arden mal, de Manuel Rivas, Guárdame bajo tierra, de Ramón Saizarbitoria, Soldados de Salamina, de Javier Cercas, Home sen nome, de Suso de Toro, y Mala gente que camina, de Benjamín Prado. Como corpus complementario, se tornó pertinente incorporar un capítulo que articula un texto fílmico (Muerte en El Valle, de Christina Hardt) con un texto literario (Las esquinas del aire. En busca de Ana María Martínez Sagi, de Juan Manuel de Prada). Esto, que en principio puede parecer un apartamiento del corpus central, favoreció el análisis del tratamiento del testimonio desde la estetización de un texto fílmico o literario. Al realizar la selección, se estudiaron, junto con autores que escriben y publican en castellano, algunos textos escritos originariamente en lenguas minorizadas (gallego y euskera)

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Se propone la descripción y el análisis del empleo de la transmisión oral en la narrativa española actual como un recurso para configurar la memoria de la Guerra Civil española y del franquismo. Para ello se atendió especialmente a las estrategias que intervienen en la representación de la oralidad en relación con los diálogos y los relatos orales, entre otros procedimientos a través de los cuales se transmite el pasado traumático dentro de la ficción. Ha sido analizada la representación de la oralidad en la producción narrativa ficcional de diversos autores españoles de finales del siglo XX y comienzos del siglo XXI que han abordado la temática de la Guerra Civil en una situación particular en cuanto al surgimiento de replanteos y debates acerca del tratamiento del conflicto bélico. Los objetivos generales que guiaron el trabajo han sido indagar la presencia y la función de la transmisión oral en la literatura, profundizar el estudio de la oralidad como voz emergente de colectivos sociales desplazados y analizar la funcionalidad del empleo de la oralidad en textos representativos de la narrativa española contemporánea. A su vez, más específicamente, se propuso profundizar en el estudio de la ficcionalización de la transmisión oral como un artificio para la construcción de la memoria en la narrativa española actual, vincular las posibilidades de transmisión de la historia de la Guerra Civil española con medios propios de la historia oral en la literatura -especialmente en la novela-, problematizar determinadas perspectivas sobre el testimonio en la medida en que son literaturizadas para una concepción de la memoria de la Guerra Civil, de la posguerra y de la dictadura, y estudiar algunas miradas contemporáneas acerca de la Guerra Civil y del franquismo desde el campo de la narrativa como un correlato de ciertos reclamos sociales de la actualidad respecto del pasado reciente. Para esto fueron analizadas diversas propuestas que surgieron esencialmente desde la literatura -con algún detenimiento en un texto fílmico- para abordar el pasado traumático y se consideraron las técnicas de transmisión empleadas para la narración ficcional de aspectos largamente silenciados por la historia oficial. El corpus central de textos literarios ha quedado conformado por O lapis do carpinteiro y Os libros arden mal, de Manuel Rivas, Guárdame bajo tierra, de Ramón Saizarbitoria, Soldados de Salamina, de Javier Cercas, Home sen nome, de Suso de Toro, y Mala gente que camina, de Benjamín Prado. Como corpus complementario, se tornó pertinente incorporar un capítulo que articula un texto fílmico (Muerte en El Valle, de Christina Hardt) con un texto literario (Las esquinas del aire. En busca de Ana María Martínez Sagi, de Juan Manuel de Prada). Esto, que en principio puede parecer un apartamiento del corpus central, favoreció el análisis del tratamiento del testimonio desde la estetización de un texto fílmico o literario. Al realizar la selección, se estudiaron, junto con autores que escriben y publican en castellano, algunos textos escritos originariamente en lenguas minorizadas (gallego y euskera)

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Microthermometric and isotopic analyses of fluid inclusions in primitive olivine gabbros, oxide gabbros, and evolved granitic material recovered from Ocean Drilling Program Hole 735B at the Southwest Indian Ridge provide new insights into the evolution of C-O-H-NaCl fluids in the plutonic foundation of the oceanic crust. The variably altered and deformed plutonic rocks span a crustal section of over 1500 m and record a remarkably complex magma-hydrothermal history. Magmatic fluids within this suite followed two chemically distinct paths during cooling through the subsolidus regime: the first path included formation of CO2+CH4+H2O+C fluids with up to 43 mole% CH4; the second path produced hypersaline brines that contain up to 50% NaCl equivalent salinities. Subsequent to devolatilization, respeciation of magmatic CO2, attendant graphite precipitation, and cooling from 800°C to 500°C promoted formation of CH4-enriched fluids. These fluids are characterized by average d13C(CH4) values of -27.1+/-4.3 per mil (N=45) with associated d13C(CO2) compositions ranging from -24.9 per mil to -1.9 per mil (N=39), and average dD values of exsolved vapor of -41+/-12 per mil (N=23). In pods, veins, and lenses of highly fractionated residual material, hypersaline brines formed during condensation and by direct exsolution in the absence of a conjugate vapor phase. Entrapped CO2+CH4+H2O-rich fluids within many oxide-bearing rocks and felsic zones are significantly depleted in 13C (with d13C(CO2) values down to about -25 per mil) and contain CO2 concentrations higher than those predicted by equilibrium devolatilization models. We hypothesize that lower effective pressures in high-temperature shear zones promoted infiltration of highly fractionated melts and compositionally evolved volatiles into focused zones of deformation, significantly weakening the rock strength. In felsic-rich zones, volatile build-up may have driven hydraulic fracturing of gabbroic wall rocks resulting in the formation of magmatic breccias. Comparison of isotopic compositions of fluids in plutonic rocks from 735B, the MARK area of the Mid-Atlantic Ridge, and the Mid-Cayman Rise indicate (1) that the carbon isotope composition of the lower oceanic crust may be far more heterogeneous than previously believed and (2) that carbon-bearing species in the oceanic crust and their distribution at depth are highly variable.

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Weather and climate models struggle to represent lower tropospheric temperature and moisture profiles and surface fluxes in Arctic winter, not least because they lack or misrepresent physical processes that are specific to high latitudes. The Arctic boundary layer in winter has been observed to be in either a radiatively clear or cloudy state: The radiatively clear state is characterized by strong surface radiative cooling leading to the build-up of surface-based temperature inversions, whereas the cloudy state occurs when cloud liquid water is present in the atmospheric column, allowing little or no surface radiative cooling and leading to weaker and typically elevated temperature inversions. Many large-scale models have been shown to lack the cloudy state, and some do substantially underestimate stability in the clear state. We here present results from the first Lagrangian ARCtic air FORMation experiment (Larcform 1), a GASS (Global atmospheric system studies) single-column model intercomparison which reproduces these biases of large-scale models in an idealised setup.