Microwave Resonator Measurements of Atmospheric Absorption Coefficients: A Preliminary Design Study

A preliminary design study examined the feasibility of using microwave resonator measurements to improve the accuracy of atmospheric absorption coefficients and refractivity between 18 and 35 GHz. Increased accuracies would improve the capability of water vapor radiometers to correct for radio signal delays caused by Earth's atmosphere. Calibration of delays incurred by radio signals traversing the atmosphere has applications to both deep space tracking and planetary radio science experiments. Currently, the Cassini gravity wave search requires 0.8-1.0% absorption coefficient accuracy. This study examined current atmospheric absorption models and estimated that current model accuracy ranges from 5% to 7%. The refractivity of water vapor is known to 1% accuracy, while the refractivity of many dry gases (oxygen, nitrogen, etc.) are known to better than 0.1%. Improvements to the current generation of models will require that both the functional form and absolute absorption of the water vapor spectrum be calibrated and validated. Several laboratory techniques for measuring atmospheric absorption and refractivity were investigated, including absorption cells, single and multimode rectangular cavity resonators, and Fabry-Perot resonators. Semi-confocal Fabry-Perot resonators were shown to provide the most cost-effective and accurate method of measuring atmospheric gas refractivity. The need for accurate environmental measurement and control was also addressed. A preliminary design for the environmental control and measurement system was developed to aid in identifying significant design issues. The analysis indicated that overall measurement accuracy will be limited by measurement errors and imprecise control of the gas sample's thermodynamic state, thermal expansion and vibration- induced deformation of the resonator structure, and electronic measurement error. The central problem is to identify systematic errors because random errors can be reduced by averaging. Calibrating the resonator measurements by checking the refractivity of dry gases which are known to better than 0.1% provides a method of controlling the systematic errors to 0.1%. The primary source of error in absorptivity and refractivity measurements is thus the ability to measure the concentration of water vapor in the resonator path. Over the whole thermodynamic range of interest the accuracy of water vapor measurement is 1.5%. However, over the range responsible for most of the radio delay (i.e. conditions in the bottom two kilometers of the atmosphere) the accuracy of water vapor measurements ranges from 0.5% to 1.0%. Therefore the precision of the resonator measurements could be held to 0.3% and the overall absolute accuracy of resonator-based absorption and refractivity measurements will range from 0.6% to 1

Trade at the margin: Estimating the economic implications of preferential trade agreements

Preferential Trade Agreements (PTAs) have become the most prevalent form of international trade liberalization in recent decades, even though it remains far from clear what their effects on economies and their key units, firms, are. This paper evaluates the distributional consequences of trade liberalization within industries differentiating two distinct aspects in which trade liberalization could result in higher trade flows: the intensive vs. the extensive margin of trade. In particular, we analyze whether trade liberalization leads to increased trade flows because either firms trade more volume in products they have already traded before (intensive margin) or because they start to trade products they have not traded previously (extensive margin), or both. We test these arguments for the Dominican Republic–Central America–United States Free Trade Agreement (CAFTA-DR) and exporting firms based in Costa Rica for the time-period 2008–2014. The results of our study suggest that the effects of CAFTA-DR depend not only on whether we analyze the extensive versus the intensive margin of trade but also whether the product in question is homogenous or differentiated and whether the exporting firm under analysis is small or large. In particular, we find support for the theoretical expectation that firms exporting heterogeneous products, such as textiles, gain from trade agreements, such as CAFTA-DR, in that they can export more varieties of their products. Yet at the same time, they tend to lose at the intensive margin by a reduction in their trade volume while the opposite pattern occurs for firms exporting homogenous products. Keywords: Preferential trade agreements; Product differentiation; Extensive margin of trade; Intensive margin of trad

International Interactions / What kinds of trade liberalization agreements do people in developing countries want?

One of the most striking developments in the global economy in the past decades is the rapid proliferation of preferential trade agreements (PTAs), with many of them concluded among or with participation of developing countries. On the presumption that current popular debates on trade policy are not so much about whether citizens want free trade but rather what kinds of trade liberalization they want, we examine individual trade policy preferences with regard to PTAs that can vary in content along several dimensions. To that end we carried out conjoint choice experiments embedded in representative surveys in three developing countries that differ strongly in income levels, political system, and trade liberalization history: Costa Rica, Nicaragua, and Vietnam. We conceptualize trade policy preferences as preferences over the scale and scope of trade liberalization, environmental and labor standards, and labor market access (migration). Two main findings emerge. First, non-economic considerations, such as sympathy/antipathy toward particular countries and environmental and labor rights concerns influence citizens preferences at least as much as factors based on standard economic logic. Second, preferences over particular facets (attributes) of trade liberalization, that is PTA content, are surprisingly consistent across countries, despite strong differences in macro-economic and political context.(VLID)250997

Is there a "Depth versus Participation” dilemma in international cooperation?

Much of the International Relations literature assumes that there is a "depth versus participation” dilemma in international politics: shallower international agreements attract more countries and greater depth is associated with less participation. We argue that this conjecture is too simple and probably misleading because the depth of any given cooperative effort is in fact multidimensional. This multidimensionality manifests itself in the design characteristics of international agreements: in particular, the specificity of obligations, monitoring and enforcement mechanisms, dispute settlement mechanisms, positive incentives (assistance), and organizational structures (secretariats). We theorize that the first three of these design characteristics have negative and the latter three have positive effects on participation in international cooperative efforts. Our empirical testing of these claims relies on a dataset that covers more than 200 global environmental treaties. We find a participation-limiting effect for the specificity of obligations, but not for monitoring and enforcement. In contrast, we observe that assistance provisions in treaties have a significant and substantial positive effect on participation. Similarly, dispute settlement mechanisms tend to promote treaty participation. The main implication of our study is that countries do not appear to stay away from agreements with monitoring and enforcement provisions, but that the inclusion of positive incentives and dispute settlement mechanisms can promote international cooperation. In other words, our findings suggest that policymakers do not necessarily need to water down global treaties in order to obtain more participatio

Atmospheric Entry Studies for Venus Missions: 45 Sphere-Cone Rigid Aeroshells and Ballistic Entries

The present study considers direct ballistic entries into the atmosphere of Venus using a 45deg sphere-cone rigid aeroshell, a legacy shape that has been used successfully in the past in the Pioneer Venus Multiprobe Mission. For a number of entry mass and heatshield diameter combinations (i.e., various ballistic coefficients) and entry velocities, the trajectory space in terms of entry flight path angles between skip out and -30deg is explored with a 3DoF trajectory code, TRAJ. From these trajectories, the viable entry flight path angle space is determined through the use of mechanical and thermal performance limits on the thermal protection material and science payload; the thermal protection material of choice is entry-grade carbon phenolic, for which a material thermal response model is available. For mechanical performance, a 200 g limit is placed on the peak deceleration load experienced by the science instruments, and 10 bar is assumed as the pressure limit for entry-grade carbon-phenolic material. For thermal performance, inflection points in the total heat load distribution are used as cut off criteria. Analysis of the results shows the existence of a range of critical ballistic coefficients beyond which the steepest possible entries are determined by the pressure limit of the material rather than the deceleration load limit

O palácio das ilusões da tradução austeniana : “Orgulho e preconceito” no sistema literário

Nas décadas de 1930 e 1940, o mercado editorial brasileiro passou por sérias crises e mudanças, as quais acabaram contribuindo para o crescimento da tradução no país, transformando essas décadas na Era de Ouro da tradução. Esta pesquisa, vinculada ao projeto “Tradução e sistema literário – história da tradução no Brasil: a tradução dos clássicos e os escritores/tradutores”, objetiva investigar esse período e sua importância para a história da tradução no Brasil, juntamente com o lugar ocupado pela Editora José Olympio nesse contexto com relação aos clássicos literários estrangeiros traduzidos por autores brasileiros. Em um segundo momento, analisaremos as traduções de duas das obras de Jane Austen publicadas pela José Olympio na Coleção Fogos Cruzados, Orgulho e preconceito, traduzida por Lúcio Cardoso, em 1941, e Mansfield Park, traduzida por Rachel de Queiroz, em 1942. Será feito um estudo comparativo das obras com suas traduções mais recentes, a de Orgulho e preconceito por Alexandre Barbosa de Souza (Penguin Companhia, 2011), e a de Mansfield Park de Mariana Menezes Neumann (BestBolso, 2011). Com isso, pretendemos analisar a apresentação da obra traduzida em relação à sua economia estética e aos paratextos editoriais.During the 1930’s and 1940’s, the Brazilian publishing industry experienced many crisis and changes that, surprisingly as it may be, contributed to the development of the translation practice in Brazil, making of these decades the Golden Age of translation. This research project is part of a major project, “Translation and literary system – the history of translation in Brazil: translation of canons and the writers/translators”, and aimed to investigate this period of time and its importance to the Brazilian translation history. It also studied the role of the Editora José Olympio in this context, regarding the translations of literary classics by Brazilian writers. After that, we analyzed the translations of two of Jane Austen’s titles that have been published by the Editora José Olympio in the Fogos Cruzados Collection, Pride and Prejudice, translated by Lúcio Cardoso, 1941, and Mansfield Park, translated by Rachel de Queiroz, 1942. We conducted a comparative study between these titles and their most recent translations: Pride and Prejudice, translated by Alexandre Barbosa de Souza (Penguin Companhia, 2011), and Mansfield Park, translated by Mariana Menezes Neumann (BestBolso, 2011). By doing this, we aimed to analyze the way these texts were presented to public, regarding its aesthetics and paratexts

Kill and cure: genomic phylogeny and bioactivity of Burkholderia gladioli bacteria capable of pathogenic and beneficial lifestyles.

Burkholderia gladioli is a bacterium with a broad ecology spanning disease in humans, animals and plants, but also encompassing multiple beneficial interactions. It is a plant pathogen, a toxin-producing food-poisoning agent, and causes lung infections in people with cystic fibrosis (CF). Contrasting beneficial traits include antifungal production exploited by insects to protect their eggs, plant protective abilities and antibiotic biosynthesis. We explored the genomic diversity and specialized metabolic potential of 206 B. gladioli strains, phylogenomically defining 5 clades. Historical disease pathovars (pv.) B. gladioli pv. allicola and B. gladioli pv. cocovenenans were distinct, while B. gladioli pv. gladioli and B. gladioli pv. agaricicola were indistinguishable; soft-rot disease and CF infection were conserved across all pathovars. Biosynthetic gene clusters (BGCs) for toxoflavin, caryoynencin and enacyloxin were dispersed across B. gladioli, but bongkrekic acid and gladiolin production were clade-specific. Strikingly, 13 % of CF infection strains characterized were bongkrekic acid-positive, uniquely linking this food-poisoning toxin to this aspect of B. gladioli disease. Mapping the population biology and metabolite production of B. gladioli has shed light on its diverse ecology, and by demonstrating that the antibiotic trimethoprim suppresses bongkrekic acid production, a potential therapeutic strategy to minimize poisoning risk in CF has been identified

Aerocapture Systems Analysis for a Neptune Mission

A Systems Analysis was completed to determine the feasibility, benefit and risk of an aeroshell aerocapture system for Neptune and to identify technology gaps and technology performance goals. The systems analysis includes the following disciplines: science; mission design; aeroshell configuration; interplanetary navigation analyses; atmosphere modeling; computational fluid dynamics for aerodynamic performance and aeroheating environment; stability analyses; guidance development; atmospheric flight simulation; thermal protection system design; mass properties; structures; spacecraft design and packaging; and mass sensitivities. Results show that aerocapture is feasible and performance is adequate for the Neptune mission. Aerocapture can deliver 1.4 times more mass to Neptune orbit than an all-propulsive system for the same launch vehicle and results in a 3-4 year reduction in trip time compared to all-propulsive systems. Enabling technologies for this mission include TPS manufacturing; and aerothermodynamic methods for determining coupled 3-D convection, radiation and ablation aeroheating rates and loads

Ballistic Entries at Venus

Exploration of Venus atmospheric entry trajectory space using a rigid aeroshel