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Volume 6, Issue 1 (9-2006)
Abstract

Various thermo mechanical processes have been studied to improve the mechanical properties of 18Ni-Co-Mo steels. In this work, the effect of interpass aneal time on the mechanical properties of the 18Ni-Co-Mo steel was investigated, using the rolling experiments. Hot rolling process was performed in two passes. The reduction of area was 30% in the first pass at 1100 °C. After first pass specimens were air cooled to second pass temperature (900°C) and held for various interpass time (2 sec, 5 min and 10 min). The second pass was performed at 900°C for 20% reduction of area. After that, the specimens were directly water quenched to retain the microstructure present at the second pass. Tensile and charpy tests samples were machined from hot rolled specimens. The results showed that grain size was decreased significantly at these conditions by increasing the interpass time from 2 sec to 5 min. This was attributed to the static recrystallization. With an increase in interpass time to 5 min, tensile strength was increased, without significant change in charpy impact energy. Increasing the interpass time from 5 to 10 min, increased austenite grain size. This was attributed to the grain growth. The results indicated that the interpass time of 5 min can be considered to obtain the maximum tensile strength.
Alireza Naseri, Mehdi Basakha, Mohammad Hasanzadeh, Arashk Masaeli,
Volume 9, Issue 4 (3-2010)
Abstract

Considering changes in economic conditions and global priorities in the last decade, development objectives such as poverty reduction and income distribution were typically cast in terms of economic growth. Therefore, poverty reduction through rural development was at the center of government development plan. The objective of this study is to analyze the impact of government spending on the rural economic development. The development indicators included in the model comprise agricultural production, non-farm employment and poverty reduction. To this end, the elasticity of the above indicators is estimated with respect to rural infrastructures such as education, transportation, telecommunication and electricity capacity and then linkage between rural infrastructures and government spending are identified. A system of simultaneous equations approach is used to model and estimate the equations using the data over the period 1981-2005. Results of estimate indicate that government spending have positive and significant impact on the poverty reduction and non-farm employment.

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