Viscous-shock-layer analysis of hypersonic flows over long slender vehicles

An efficient and accurate method for solving the viscous shock layer equations for hypersonic flows over long slender bodies is presented. The two first order equations, continuity and normal momentum, are solved simultaneously as a coupled set. The flow conditions included are from high Reynolds numbers at low altitudes to low Reynolds numbers at high altitudes. For high Reynolds number flows, both chemical nonequilibrium and perfect gas cases are analyzed with surface catalytic effects and different turbulence models, respectively. At low Reynolds number flow conditions, corrected slip models are implemented with perfect gas case. Detailed comparisons are included with other predictions and experimental data

Human computer interaction for international development: past present and future

Recent years have seen a burgeoning interest in research into the use of information and communication technologies (ICTs) in the context of developing regions, particularly into how such ICTs might be appropriately designed to meet the unique user and infrastructural requirements that we encounter in these cross-cultural environments. This emerging field, known to some as HCI4D, is the product of a diverse set of origins. As such, it can often be difficult to navigate prior work, and/or to piece together a broad picture of what the field looks like as a whole. In this paper, we aim to contextualize HCI4D—to give it some historical background, to review its existing literature spanning a number of research traditions, to discuss some of its key issues arising from the work done so far, and to suggest some major research objectives for the future

Evaluation of rice cultivars for resistance to rice yellow mottle virus

Rice yellow mottle virus (RYMV), which is only found in Africa, threatens rice farming on the continent. A local Oryza sativa cultivar collected from Burkina Faso (named BM24), was evaluated with that of well known highly resistant and tolerant cultivars. Firstly, three RYMV isolates were used to characterise the differential interaction within the cultivars. Secondly, disease kinetics of symptom expression and virus titer on leaves at 21 days after inoculation were assessed using the BF1 isolate. Thirdly, the allelic profile of O. sativa varieties using SSR marker RM101 located on chromosome 12 was also assessed. IR64 showed susceptibility to all isolates; while Tog5681 was resistant to all isolates. Ng122 overcame the resistance of Gigante, with mild leaf symptoms at 42 dpi. Azucena and BM24 had, therefore, different resistance level regarding the three isolates (Ng117b, Ng122 and Ng144). When infected with the isolate, BF1, BM24 and Azucena exhibited same resistance patterns in early growth stages with delayed of symptoms appearance, but BM24 outperformed Azucena at later stages. The virus content in the two accessions, at 14 days post inoculation, was statistically different with BM24, showing less virus compared to Azucena. However, the two accessions depicted an identical allelic profile at RM101 locus

Measuring Spillovers from Alternative Forms of Foreign Investment

Much of the endogenous growth literature has dwelled on evaluating the spillover effects of trade on growth, but much less efforts have been directed towards tracing and quantifying the spillover effects of foreign investments. This paper, in incorporating the effects of various types of foreign investments, namely foreign direct investment (FDI), foreign portfolio investment (FPI) and other foreign investment (OFI) fills this gap in the literature. Adopting the stochastic frontier approach, this paper constructs an OECD frontier based on a panel dataset of 20 OECD countries over the 1981-2000 period. Spillover effects of FDI, FPI, OFI and trade are gauged by their respective contributions towards reducing technical inefficiencies, which are represented by the distance of each country from the constructed frontier. Results from the multiple models examined in the paper indicate that inflows of foreign investment and trade have been instrumental in reducing inefficiencies across OECD countries, whereas outflows of foreign investment exacerbate inefficiencies. The study also confirms some previous findings that the spillover effects of FDI inflows are larger than that of trade but does not find evidence in favour of the view that the spillover effects of trade are overestimated when FDI flows are excluded from the analysis. Moreover, the impact of FDI inflows is larger than those of FPI and OFI inflows. The importance of absorptive capacities of host economies in capturing spillover gains from FDI inflows is also examined. Amongst the various measures of absorptive capacity considered, only human capital was found to be important.

Measuring Efficiency externalities from Trade and Alternative Forms of Foreign Investment

The literature has concentrated on evaluating technological spillovers from trade and inflows of foreign direct investment (FDI). Little effort has been directed towards identifying efficiency externalities arising from international linkages. We evaluate these for a sample of 20 OECD countries between 1982 and 2000 using a stochastic frontier approach. The analysis includes trade, inflows and outflows of FDI, foreign portfolio investment (FPI), and other foreign investment (OFI), and a measure of the absorptive capacities of host economies. We find trade and all foreign investment inflows to lead to increased efficiency. Outflows of FDI are found to exacerbate inefficiency.

Computer codes for the evaluation of thermodynamic and transport properties for equilibrium air to 30000 K

The computer codes developed here provide self-consistent thermodynamic and transport properties for equilibrium air for temperatures from 500 to 30000 K over a temperature range of 10 (exp -4) to 10 (exp -2) atm. These properties are computed through the use of temperature dependent curve fits for discrete values of pressure. Interpolation is employed for intermediate values of pressure. The curve fits are based on mixture values calculated from an 11-species air model. Individual species properties used in the mixture relations are obtained from a recent study by the present authors. A review and discussion of the sources and accuracy of the curve fitted data used herein are given in NASA RP 1260

Computer codes for the evaluation of thermodynamic properties, transport properties, and equilibrium constants of an 11-species air model

The computer codes developed provide data to 30000 K for the thermodynamic and transport properties of individual species and reaction rates for the prominent reactions occurring in an 11-species nonequilibrium air model. These properties and the reaction-rate data are computed through the use of curve-fit relations which are functions of temperature (and number density for the equilibrium constant). The curve fits were made using the most accurate data believed available. A detailed review and discussion of the sources and accuracy of the curve-fitted data used herein are given in NASA RP 1232

Analysis of Development Performance Using a Development Index Based on Factor Analysis (Old Title- Constructing Multideminsional Indexes of Economic Structure and Development)

Development involves changes in social, economic and institutional structures. Quantifying development requires a large array of variables with different characteristics often highly correlated. A factor analysis approach using inferential decisions based on computed standard errors is proposed. The significant factors are used to construct sub-indexes of structural characteristics and a new development index (DI). The properties of DI are analysed and contrasted with more traditional measures, real per capita income (RIPC) and the Human Development Index (HDI). The methodology is applied to data on 45 variables for 97 countries for 1995-2004. DI is found to have stronger discriminating power.

A review of reaction rates and thermodynamic and transport properties for an 11-species air model for chemical and thermal nonequilibrium calculations to 30000 K

Reaction rate coefficients and thermodynamic and transport properties are reviewed and supplemented for the 11-species air model which can be used for analyzing flows in chemical and thermal nonequilibrium up to temperatures of 3000 K. Such flows will likely occur around currently planned and future hypersonic vehicles. Guidelines for determining the state of the surrounding environment are provided. Curve fits are given for the various species properties for their efficient computation in flowfield codes. Approximate and more exact formulas are provided for computing the properties of partially ionized air mixtures in a high energy environment. Limitations of the approximate mixing laws are discussed for a mixture of ionized species. An electron number-density correction for the transport properties of the charged species is obtained. This correction has been generally ignored in the literature