Static aeroelasticity of a composite oblique wing in transonic flows

One aircraft configuration that shows great promise in achieving high performance is that of an asymmetrically swept wing. When compared to conventional swept wings, these advantages include higher lift to drag ratios and reduced takeoff and landing speeds, which translate into greater performance in terms of fuel comsumption, loiter time, and range. However, the oblique wing has a number of disadvantages because of its asymmetric configuration. The question is how to best achieve maximum stability and roll equilibrium without compromising performance. Using aeroelastic tailoring to enhance aeroelastic stability and control has been demonstrated in several analyses, especially for the forward swept wing. The advantages and disadvantages for the oblique wing configuration are discussed

Segmented switchers and retailer pricing strategies

Empirical studies reveal a surprisingly wide variety of price promotion strategies among retailers, even among Internet sellers of undifferentiated homogenous goods such as books and music CD’s. Several empirical findings remain puzzling, particularly that within the same market some small retailers decide to deeply discount, while other small retailers forgo the price-sensitive switchers and price high to play their niche. We present theoretical and empirical analyses that address these varied pricing strategies. Our model of three asymmetric firms shows that under multiple switcher segments, where different switchers compare prices at different retailers, firm-specific loyalty is not sufficient to explain the variety of retailer pricing strategies. We demonstrate that a retailer’s pricing strategy is driven by the ratio of the size of switcher segments for which the retailer competes to its loyal segment size. The relative switcher-to-loyal ratios among retailers explain when a firm is more or less inclined to discount deeply or frequently. We thereby identify when a small firm finds it optimal to play the niche and price high, despite having few loyals, or to discount and go for the switchers. Our analysis reveals several interesting findings, such as a small firm that benefits from strategically limiting its access to switchers. The results of two empirical studies confirm our model’s predictions for varied retailer pricing strategies in the context of Internet booksellers

Aerolastic tailoring and integrated wing design

Much has been learned from the TSO optimization code over the years in determining aeroelastic tailoring's place in the integrated design process. Indeed, it has become apparent that aeroelastic tailoring is and should be deeply embedded in design. Aeroelastic tailoring can have tremendous effects on the design loads, and design loads affect every aspect of the design process. While optimization enables the evaluation of design sensitivities, valid computational simulations are required to make these sensitivities valid. Aircraft maneuvers simulated must adequately cover the plane's intended flight envelope, realistic design criteria must be included, and models among the various disciplines must be calibrated among themselves and with any hard-core (e.g., wind tunnel) data available. The information gained and benefits derived from aeroelastic tailoring provide a focal point for the various disciplines to become involved and communicate with one another to reach the best design possible

The Impact of Hosting a Major Sport Event on the South African Economy

The impact of the sporting industry on economic decision making has increased dramatically since the global media explosion in the 1980s. Tourism and advertising revenues generated by these mega-events have become a major boost to the economies of hosting nations. In addition, globalisation has placed great emphasis on the importance of foreign direct investment (FDI), especially to developing countries. This paper seeks to examine the impact of the pre-event phase expenditure attributed to the hosting of the 2010 FIFA World Cup on the South African economy. In this phase, expenditure is mainly geared towards the construction and improvement of infrastructure required to successfully host the event. Using a Computable General Equilibrium (CGE) model developed specifically for the South African economy, the impact of the pre-event phase on the local economy is measured. It is found that there is a positive impact on most macroeconomic variables, including GDP and employment. With the potential economic benefits of the event and post-event phases of the World Cup also taken into account, it can be concluded with relative certainty that the impact of hosting a mega-event on the South African economy is beneficial towards achieving higher economic growth and development. In addition to analysing the impact of the 2010 FIFA World Cup, the outcomes are also used to briefly examine the feasibility of South Africa’s bid to host the 2011 IRB World Cup and the 2016 Olympic Games.computable general equilibrium, mega-events, economic development

Петроструктурная типизация ультрамафитов Канского зеленокаменного пояса (северо-запад Восточного Саяна)

В Канском зеленокаменном поясе (СЗ Восточного Саяна) установлены два типа ультрамафитов: магматические дунит-верлит-пикритового состава и реститовые дунит-гарцбургитового состава. Они объединены в кингашский и идарский комплексы соответственно

High-level expression of a viscotoxin in Arabidopsis thaliana gives enhanced resistance against Plasmodiophora brassicae

Viscotoxins are a group of toxic thionins found in several mistletoe species. The constitutive CaMV-Ω promoter was used to drive the expression of the viscotoxin A3 cDNA from Viscum album in transgenic Arabidopsis thaliana C24. Lines with high viscotoxin A3 levels in all parts of the plant were selected and tested for resistance against the clubroot pathogen Plasmodiophora brassicae. The transgenic lines were more resistant to infection by this pathogen than the parental lin

Algoritmos para la detección de aceite de avellana en aceite de oliva

7 pages, 5 figures, 5 tables.[EN] The fraudulent addition of hazelnut oil to olive oil can be only detected in high proportions (20-25%) using the A-stigmastenol and the difference between triacylglycerols of equivalent carbon number 42, determined experimentally by HPLC and calculated theoretically from the fatty acid composition (AECN42). A new method lies on a sequential comparison of the values of several algorithms with a database built with data obtained from genuine virgin olive oils. The algorithms are: LLLexp en función de %L; (LLL/OLLn)exp - (LLL/OLLn)teor, vs AECN44 and (ECN441LLL), vs %L; being: LLLnexpO LLnexpa nd ECN44ew the percentage of triacylglycerols determined by HPLC, LLLth, OLLnthWr and EcN44th,, the percentage of those calculated theoretically from the fatty acid wmposition; AECN44 the difference between the experimental and theoretica~v alue of ECN44; and finally %L the percentage of linoleic acid. The database has been built considering the values obtained from olive oils of diierent fatty acid composition and from admixtures between them. The method allows the detection of low percentages of hazelnut oil in olive oii ( 5%).[ES] La adición fraudulenta de aceite de avellana en aceite de oliva puede ser detectada sólo en altas proporciones (20–25 %), usando el D7-estigmastenol y la diferencia entre los triglicéridos con número de carbono equivalente igual a 42, determinados experimentalmente por HPLC y teóricamente a partir de la composición de ácidos grasos (DECN42). Se propone un nuevo método que consiste en la comparación de los valores de varios algoritmos con una base de datos de valores experimentales obtenidos de aceites de oliva virgen genuinos. Estos algoritmos son: LLLexp en función de %L; (LLL/OLLn)exp - (LLL/OLLn)teor en función de DECN44 y (ECN44/LLL)exp en función de %L; siendo LLLexp, OLLnexp, y ECN44exp los porcentajes de los triglicéridos obtenidos por HPLC; LLLteor , OLLnteor, y ECN44teor los porcentajes de éstos calculados teóricamente a partir de la composición de ácidos grasos; DECN44 la diferencia entre el valor experimental y teórico del ECN44; y finalmente %L el porcentaje de ácido linoleico. La base de datos se ha recopilado considerando los valores obtenidos de aceites de oliva de diferentes composiciones de ácidos grasos y mezclas entre ellos. El método permite la detección de pequeños porcentajes (5 %) de aceites de avellana en aceites de oliva.We thank to Ministry of Agriculture for the financia1 support (INIA CA098-005).Peer reviewe

Constrictive tuberculous pericarditis in a HIV-positive patient

Constrictive pericarditis is a relatively rare clinical manifestation nowadays. We present the case of an HIV-positive patient with constrictive calcified pericarditis due to an infection with Mycobacterium tuberculosis. Pericardectomie was performed. The therapeutical approach is discussed and the literature is reviewe