The domestic resource cost concept: Theory and an empirical application to the case of Spain

The problem of how to make an optimum use of a country's limited productive resources is often a crucial one to the policy makers in less developed countries (LDCs). Not surprisingly, therefore, the various methods of cost-benefit analysis have attracted much attention among professional economists and are finding a wide spread application in evaluating the social profitability of investment projects and in the planning decision-making process as well. Relatively less attention has been paid to yet another criterion of project appraisal in a developing country that has been developed independently of social cost benefit analysis - the so called domestic resource cost (DRC) approach to project appraisals. This approach is properly regarded as the application of the propositions of allocation theory when the project, or the industry in question, produces (or saves) foreign exchange. The DRC concept compares the opportunity costs of domestic resources (primary factors such as labour, capital, land) conmitted to the production of final goods with prices at which these goods can be exported or imported - the latter prices (the foreign exchange gained or saved) being considered as the ensuing benefits from production. The rationale for using the foreign exchange gained (through exports) or saved (through imports) as a standard of reference is that foreign exchange is relatively, and often critically, scarce in many developing countries.

Enhancement in thermoelectric power in lead telluride nanocomposite: role of oxygen vis-a-vis nanostruct

The present work reports enhanced power factor and reduced value of room temperature thermal conductivity in undoped PbTe nanocomposite, prepared from PbTe nanocrystals, synthesized via chemical route. The highest power factor is found to be 19.21 ´ 10 –4 Wm –1K –2 with room temperature thermal conductivity of 1.53 Wm –1K –1. The potential barrier at the sharp interfaces of the grains of the nanocomposites, occurred due to the adsorption of oxygen by the grain surfaces, have been found to play the main role to produce the high value of Seebeck coefficient (416 mV/K at 500 K) by preferentially scattering the lower energy electrons and thus enhancing the power factor. The lattice destruction at the grain interfaces has been found to cause the remarkable reduction in thermal conductivity, through scattering a wide spectrum of phonon wavelength. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2205

Development of low cost packaged fibre optic sensors for use in reinforced concrete structures

There is an ongoing need to measure strains in reinforced concrete structures more reliably and under a range of circumstances e.g. long term durability (such as effects of cracking and reinforcement corrosion), response to normal working loads and response under abnormal load conditions. Fibre optic sensors have considerable potential for this purpose and have the additional advantages, including of immunity to electromagnetic interference and light weight (Grattan et al., 2000). This is important in railway scenarios and particularly so when the lines are electrified. Their small size allows for easy installation. However, their use as commercial ‘packaged’ devices (traditionally seen as necessary to achieve adequate robustness) is limited by their high cost relative to other sensor devices such as encapsulated electric resistance strain gauges. This paper describes preliminary work to produce a cost-effective and easy-to-use technique for encapsulating fibre optic sensors in resin using 3D printing techniques to produce a robust, inexpensive ‘packaged’ sensor system suitable for use with concrete structures. The work done to date has shown this to be a convenient and economical way of producing multiple sensors which were suitable for both surface mounting and embedment in reinforced concrete structures. The proof-of-concept testing to which the trial packages were subjected is described in the paper and the results indicate that 3D printed packages have considerable potential for further development and use in a variety of civil engineering applications, competing well with more conventional sensor systems

Economic development and the patterns of manufactured exports

The need to expand the export of manufactures from less developed countries has now been realised by national and international bodies. To device meaningful policies, it seems necessary to understand whether and how the share of manufactures in a country's total exports is related to certain supply-oriented characteristics. For this purpose, a multiple regression analysis on the basis of cross-sectional data is attempted in this study . In a pooled sample of developed and developing countries, the share of manufactures in total exports is positively associated not only with the level of per capita income and the degree of industrialisation , but also with the density and size of population and ( though not statistically significant ) the availability of skills . All these variables together explain statistically more than 60 per cent of the total variation in observed data on the share of manufactures in total exports. The share of manufactures in total exports is likely to increase rapidly with per capita income, but only up to a certain point after which it levels off. Countries with a high density of population tend to export manufactures at an earlier stage and in greater proportion than countries with a low density. For most of the developed countries the actual shares of industrial exports are seen to have exceeded the "expected" shares, whereas for most of the less developed countries the reverse holds true . When the cross-section analysis is confined to less developed countries only, the share of manufactures in total exports, although positively associated with the degree of industrialisation , is conversely ( but not significantly ) related to per capita income

The domestic resource cost concept: Theory and an empirical application to the case of Spain

The problem of how to make an optimum use of a country's limited productive resources is often a crucial one to the policy makers in less developed countries (LDCs). Not surprisingly, therefore, the various methods of cost-benefit analysis have attracted much attention among professional economists and are finding a wide spread application in evaluating the social profitability of investment projects and in the planning decision-making process as well. Relatively less attention has been paid to yet another criterion of project appraisal in a developing country that has been developed independently of social cost benefit analysis - the so called domestic resource cost (DRC) approach to project appraisals. This approach is properly regarded as the application of the propositions of allocation theory when the project, or the industry in question, produces (or saves) foreign exchange. The DRC concept compares the opportunity costs of domestic resources (primary factors such as labour, capital, land) conmitted to the production of final goods with prices at which these goods can be exported or imported - the latter prices (the foreign exchange gained or saved) being considered as the ensuing benefits from production. The rationale for using the foreign exchange gained (through exports) or saved (through imports) as a standard of reference is that foreign exchange is relatively, and often critically, scarce in many developing countries

Density-and trait-mediated effects of a parasite and a predator in a tri-trophic food web

1. Despite growing interest in ecological consequences of parasitism in food webs, relatively little is known about effects of parasites on long-term population dynamics of non-host species or about whether such effects are density- or trait- mediated. 2. We studied a tri-trophic food chain comprised of: (i) a bacterial basal resource (Serratia fonticola), (ii) an intermediate consumer (Paramecium caudatum), (iii) a top predator (Didinium nasutum), and (iv) a parasite of the intermediate consumer (Holospora undulata). A fully-factorial experimental manipulation of predator and parasite presence/absence was combined with analyses of population dynamics, modelling, and analyses of host (Paramecium) morphology and behavior. 3. Predation and parasitism each reduced the abundance of the intermediate consumer (Paramecium), and parasitism indirectly reduced the abundance of the basal resource (Serratia). However, in combination, predation and parasitism had non-additive effects on the abundance of the intermediate consumer, as well as on that of the basal resource. In both cases, the negative effect of parasitism seemed to be effaced by predation. 4. Infection of the intermediate consumer reduced predator abundance. Modelling and additional experimentation revealed that this was most likely due to parasite reduction of intermediate host abundance (a density-mediated effect), as opposed to changes in predator functional or numerical response. 5. Parasitism altered morphological and behavioural traits, by reducing host cell length and increasing the swimming speed of cells with moderate parasite loads. Additional tests showed no significant difference in Didinium feeding rate on infected and uninfected hosts, suggesting that the combination of these modifications does not affect host vulnerability to predation. However, estimated rates of encounter with Serratia based on these modifications were higher for infected Paramecium than for uninfected Paramecium. 6. A mixture of density-mediated and trait-mediated indirect effects of parasitism on non- host species creates rich and complex possibilities for effects of parasites in food webs that should be included in assessments of possible impacts of parasite eradication or introduction

Superrevivals in the quantum dynamics of a particle confined in a finite square well potential

We examine the revival features in wave packet dynamics of a particle confined in a finite square well potential. The possibility of tunneling modifies the revival pattern as compared to an infinite square well potential. We study the dependence of the revival times on the depth of the square well and predict the existence of superrevivals. The nature of these superrevivals is compared with similar features seen in the dynamics of wavepackets in an anharmonic oscillator potential.Comment: 8 pages in Latex two-column format with 5 figures (eps). To appear in Physical Review

Galaxy Zoo:reproducing galaxy morphologies via machine learning

We present morphological classifications obtained using machine learning for objects in SDSS DR6 that have been classified by Galaxy Zoo into three classes, namely early types, spirals and point sources/artifacts. An artificial neural network is trained on a subset of objects classified by the human eye and we test whether the machine learning algorithm can reproduce the human classifications for the rest of the sample. We find that the success of the neural network in matching the human classifications depends crucially on the set of input parameters chosen for the machine-learning algorithm. The colours and parameters associated with profile-fitting are reasonable in separating the objects into three classes. However, these results are considerably improved when adding adaptive shape parameters as well as concentration and texture. The adaptive moments, concentration and texture parameters alone cannot distinguish between early type galaxies and the point sources/artifacts. Using a set of twelve parameters, the neural network is able to reproduce the human classifications to better than 90% for all three morphological classes. We find that using a training set that is incomplete in magnitude does not degrade our results given our particular choice of the input parameters to the network. We conclude that it is promising to use machine- learning algorithms to perform morphological classification for the next generation of wide-field imaging surveys and that the Galaxy Zoo catalogue provides an invaluable training set for such purposes

Coherent states of P{\"o}schl-Teller potential and their revival dynamics

A recently developed algebraic approach for constructing coherent states for solvable potentials is used to obtain the displacement operator coherent state of the P\"{o}schl-Teller potential. We establish the connection between this and the annihilation operator coherent state and compare their properties. We study the details of the revival structure arising from different time scales underlying the quadratic energy spectrum of this system.Comment: 13 pages, 6 figure

Theorems on shear-free perfect fluids with their Newtonian analogues

In this paper we provide fully covariant proofs of some theorems on shear-free perfect fluids. In particular, we explicitly show that any shear-free perfect fluid with the acceleration proportional to the vorticity vector (including the simpler case of vanishing acceleration) must be either non-expanding or non-rotating. We also show that these results are not necessarily true in the Newtonian case, and present an explicit comparison of shear-free dust in Newtonian and relativistic theories in order to see where and why the differences appear.Comment: 23 pages, LaTeX. Submitted to GR