amin hoseini

In this paper, while reviewing the place of “space economics” in the classified theories of economic development, the aspects of its similarities and differences with respect to conventional economics are highlighted. Then, the concept of space economics, its origin, the challenges of the foundations of the two kinds of paradigms between the space economics and conventional economics are discussed. These challenges have not only led to the new regional development policies in the 21st century, but have also brought about new challenges. On the one hand, the World Bank’s annual report, first addresses the issue of reshaping economic geography in the framework of “place neutral” or “place blind”, which appears to be the basis of regional development policies. In contrast to that, European Union (EU) embraces the role of “place-based” and “place-bound” theories for analyzing regional development policies. Taking these two paradigms into accounts and also considering the five decades of regional development policy experience in Iran, this paper seeks to answer the following question: “which one of the two paradigms has been used as the basis of analysis in the regional development policy in Iran?” Findings indicate that for various reasons, regional development policies in Iran have no theoretical support for regional development economics.

Titanium oxide coatings were prepared on commercially pure titanium substrates using plasma electrolytic oxidation process under current density of 0.15 A/cm2 in electrolyte containing 5-15 g/L potassium phosphate for period of 120-600 s. The effects of oxidation time and electrolyte concentration on surface morphology, thickness, roughness, relative porosity, pores size distribution, microstructure and corrosion behavior were evaluated. Investigation of voltage-time variations showed that increasing the electrolyte concentration up to 15 g/l caused an acceleration of microdischarge events and reduced the breakdown voltage from 593 V to 516 V. Morphological observations revealed that the pores were located at long distances and protuberances around the pores were more prominent. By increasing the oxidation time to 600 s, the thickness and roughness of the coatings increased, and due to the presence of 11% porosity of the coating surface, the total number of pores with diameters greater than 1 μm to 18% of the total surface pores reached. Investigation of the corrosion behavior revealed that the thickness of 8.2 ± 0.3 μm and low porosity, increased the corrosion resistance of the sample coated in the concentration of 15 g/L of potassium phosphate up to 1670 kΩ.cm2.

In this paper, design and simulation of a side pumped Er:Yb:glass laser is reported. We designed an air cooled system for using Close Coupling method and reduction of the volume and the weight of the system. In this case, symmetrizing and uniformity of pumping is done by using of three laser diodes to pump at a Y shape structure. To optimize system designed, energy and shape of the output laser is studied by change of the main components of the resonator parameters that we could increase the output energy, reduce the pulse width and achieve desired divergence without using of the optical elements. By this condition, we derived a pulse with output energy of 17.8 mJ, pulse width of 13.2 ns and beam with divergence of 4 mrad at repetition rate of 10 Hz in the eye safe band.