Mechanical Properties Improvement of Low Carbon Steel by Combined Heat Treatments

The improvement of the Mechanical properties of the low Carbon steel and increasing its strength, was the goal of some heat treatment technologies developed in the last twenty years. One of these technologies is the Rapid Heat Treatment (RHT), by which the strength of steel increases with the crystalline grain size decrease obtained from the rapidity of austenitizing, and more strength increase may be obtained, if the action of austenitizing is followed by rapid cooling or quenching, but in this case, ductility will decrease simultaneously by increasing the cooling rate. Another mechanical properties improving heat treatment, is the Intercritical Heat Treatment (IHT), by which the ferrite-pearlite structure of low Carbon steel transforms to Dual-Phase structure of ferrite and martensite resulting increase in strength, while a great deal of its ductility is restored. Authors in this paper report about their experiments carried out on a low Carbon-steel, trying to get the advantages of the two above mentioned technologies, by subjecting the formerly rapid heat treated steel, to intercritical heat treatment,. Applying this treatment on the steel in different temperatures inside the intercritical zone, remarkable results were obtained and reported

Automatic Archeological Feature Extraction from Satellite VHR Images

Abstract Archaeological applications need a methodological approach on a variable scale able to satisfy the intra-site (excavation) and the inter-site (survey, environmental research). The increased availability of high resolution and micro-scale data has substantially favoured archaeological applications and the consequent use of GIS platforms for reconstruction of archaeological landscapes based on remotely sensed data. Feature extraction of multispectral remotely sensing image is an important task before any further processing. High resolution remote sensing data, especially panchromatic, is an important input for the analysis of various types of image characteristics; it plays an important role in the visual systems for recognition and interpretation of given data. The methods proposed rely on an object-oriented approach based on a theory for the analysis of spatial structures called mathematical morphology. The term ‘‘morphology’’ stems from the fact that it aims at analysing object shapes and forms. It is mathematical in the sense that the analysis is based on the set theory, integral geometry, and lattice algebra. Mathematical morphology has proven to be a powerful image analysis technique; two-dimensional grey tone images are seen as three-dimensional sets by associating each image pixel with an elevation proportional to its intensity level. An object of known shape and size, called the structuring element, is then used to investigate the morphology of the input set. This is achieved by positioning the origin of the structuring element to every possible position of the space and testing, for each position, whether the structuring element either is included or has a nonempty intersection with the studied set. The shape and size of the structuring element must be selected according to the morphology of the searched image structures. Other two feature extraction techniques were used, eCognition and ENVI module SW, in order to compare the results. These techniques were applied to different archaeological sites in Turkmenistan (Nisa) and in Iraq (Babylon); a further change detection analysis was applied to the Babylon site using two HR images as a pre–post second gulf war. We had different results or outputs, taking into consideration the fact that the operative scale of sensed data determines the final result of the elaboration and the output of the information quality, because each of them was sensitive to specific shapes in each input image, we had mapped linear and nonlinear objects, updating archaeological cartography, automatic change detection analysis for the Babylon site. The discussion of these techniques has the objective to provide the archaeological team with new instruments for the orientation and the planning of a remote sensing application. & 2009 Elsevier Ltd. All rights reserved

Is There a Causal Link between Currency and Debt Crisis?

debt crises, currency crises, contagion

The Impact of Aid on Recipient Behavior: A Micro-Level Dynamic Analysis of Remittances, Schooling, Work, Consumption, Investment and Social Mobility in Nicaragua

Remittances are a very important source of income for many Nicaraguan families. More than 40% of all households receive remittances that on average amount to 12-15% of total household income in these households. More than 30% of these households receive remittances at least monthly, implying that it is a relatively stable source of income. This paper shows that remittances do tend to reduce the vulnerability of households and increase their upward social mobility, at least as long as the households do not depend too heavily on remittances. However, remittances also cause moral hazard problems. Nicaraguans tend to reduce their labor supply in response to more remittances, and they also tend to reduce their savings rates, both of which are detrimental to long run economic growth.Remittances, aid, Nicaragua

Stories Untold: Art from Syria

In Damascus, a group of artists created paintings of startling intensity, rich in texture and bold to the eye, suffused with light and reflecting alternate realities: the resilience of a highly cultured people with a civilization of seven thousand years and a history of survival and reinvention. While the machines of war produced death, amid the blood and terror, the devastation and savagery, these artists produced images of hope and beauty that were brought together in an exhibition held in Athens and other parts of Greece. The paintings that accompany Ghanem’s article, “Stories Untold: Art from Syria,” also the name of the exhibition, allow readers to experience these artists’ works. Their paintings reflect “the life-loving spirit of Syria, reminding us of the legendary phoenix that reinvents and invigorates itself from its ashes.” The images, Ghanem tells us, take us to “mystical realms, where a child symbolizes life, joy and hope for the future and a woman symbolizes home, love, and life-giving force, and where beauty is strength, vigor, and optimism. These eternal symbols bring us together in harmony and peace regardless of our differences to complete the circle of love around us all.

A Theory of Workers' Remittances with an Application to Morocco

This paper provides a model on how altruism, "attachment" to the home country, and portfolio diversification may act as potential motives behind workers' remittances. It shows that the level of workers' remittances depends on how great are their degrees of altruism and "attachment" to their home country, and should also depend on interest rate differentials between the home country and the country of residence if portfolio diversification motives are significant in the decision to remit. The model is applied to Morocco using co-integration techniques. The paper then discusses the stability of remittances in Morocco and the policyimplications in light of the empirical findings

Determinants of workers’ remittances: evidence from the European Neighbouring Region

Workers’ remittances have become the second largest source of net financial flows to developing countries. However, the main motives for sending remittances remain controversial. This paper examines the importance of altruistic versus investment motives using a new panel data set of bilateral flows from 21 Western European to 7 EU neighbouring countries. We find that altruism is important for remitting, as the GDP differential between sending and receiving countries is positively correlated with the average remittance per migrant. By contrast, interest rate differentials are insignificant, suggesting a weak investment motive. Finally, migrants’ skills raise remittances, while a large informal economy in the sending country depresses official remittance flows. JEL Classification: D13, D64, F22, F24, O15altruism, balance of payments, migrants' skills, migration, remittances

Atmospheric CH4 and N2O measurements near Greater Houston area landfills using a QCL-based QEPAS sensor system during DISCOVER-AQ 2013

A quartz-enhanced photoacoustic absorption spectroscopy (QEPAS)-based gas sensor was developed for methane (CH4) and nitrous-oxide (N 2O) detection. The QEPAS-based sensor was installed in a mobile laboratory operated by Aerodyne Research, Inc. to perform atmospheric CH 4 and N2O detection around two urban waste-disposal sites located in the northeastern part of the Greater Houston area, during DISCOVER-AQ, a NASA Earth Venture during September 2013. A continuous wave, thermoelectrically cooled, 158 mW distributed feedback quantum cascade laser emitting at 7.83 μm was used as the excitation source in the QEPAS gas sensor system. Compared to typical ambient atmospheric mixing ratios of CH4 and N2O of 1.8 ppmv and 323 ppbv, respectively, significant increases in mixing ratios were observed when the mobile laboratory was circling two waste-disposal sites in Harris County and when waste disposal trucks were encountered. © 2014 Optical Society of America

A Note on Remittances in El Salvador and Ecuador: An Analysis of Household Survey Data

This study analyzes the impact of remittances as seen in household survey data from three small rural communities. OLS and multivariate anova regressions were used to analyze household survey data collected in Cumbe and Gualaceo (Ecuador) and in Ciudad Romero (El Salvador). The results contradict the findings of some studies concluding that in many countries remittances acted as “compensation for poor economic performance” rather than capital promoting economic development. Ce papier a pour objectif de proposer une étude de cas sur l’impact des transferts de fonds individuels des émigrés vers leur village d’origine. L’étude repose sur des données collectées dans le cadre d’entretiens individuels réalisés dans trois villages : Cumbe et Gualaceo (Equateur) et Ciudad Romero (El Salvador). Les résultats contredisent, dans le cadre de ces villages, certaines études précédentes qui concluaient en l’absence d’impacts de long-terme des fonds transférés. En utilisant un modèle simple fondé sur la méthode des moindres carrés ordinaires complété par une analyse de variance multi-variée, cette étude montre un impact positif des transferts de fonds sur l’investissement, en plus d’être un soutien financier pour les produits de première nécessité.remittances, Latin America, development, human capital, foreign aid , transferts de fonds, Amérique latine, développement économique, capital humain, aide internationale