جستجوی مقالات مرتبط با کلیدواژه « جزایر m » در نشریات گروه « فنی و مهندسی »

Geographical factors and elements, specifically geographic regions, play a role in political, economic, and social events and processes. One of these geographical regions is the Middle East, which plays an important role in world events. Iran is known as the most important country in the Persian Gulf and as one of the main and key players in important regional energy events. Therefore, it can be argued that in addition to geopolitical credibility, Iran also has unique value and capabilities in the field of geo-economics. On the other hand, Iran is important due to its transit position, which is due to its geopolitical advantages, i.e. being located at four international roads. This crossroads connects Africa to Asia and Asia to Europe. The main feature of the Persian Gulf is its set of islands, which has given it a multifaceted role. The current article studies the regional importance of the Persian Gulf and Iranian islands, in this regard, it first examines their regional and geographical characteristics and then deals with their regional and cultural characteristics, then focusing on the current natural and social characteristics of the island. Finally, according to its territorial capabilities and geopolitical and geographical talents, the areas of development and capabilities of the island in this direction have been stated.

The effect of electromagnetic vibration on the microstructure and impact toughness of API-X70 steel weld metal was investigated. The welding was carried out by gas tungsten arc welding process and using filler metals including ER80S-G and ER309L. Electromagnetic vibration under voltages 0- 30 volts concurrent with welding was applied. The microstructure of the base and weld metals using optical microscope and SEM was studied. The impact energy of weld metals at TR, 0°C and -20℃ using charpy impact test was measured. Microstructural investigations revealed that applying electromagnetic vibration have caused the finer and more uniform of Martensitic-Austenitic (MA) islands in the ER80S-G weld metal . The results showed that, due to electromagnetic vibration, the microstructure became finer and the average size of dendrites in the ER309L weld metal decreased from 18.19 to 8.01 μm.. The impact test result, illustrated that the applied vibration cause improvement of impact energy of weld metals at different temperature (TR, 0°C and -20℃). It was found that with vibration under 30V, impact energy of ER80S-D weld metal in TR, 0°C and - 20℃ was increased equal to 53, 29 and 36 percents, respectively. Besides for ER309L weld metal, the impact energy in TR and -20℃ was increased equal to 18 and 5 percents, respectively. (TR= Room Temperature).