Search published articles
Showing 2 results for Qasemian
A. Amiri, M. Shojaeefard, A. Qasemian, S. Samiezaeh,
Volume 20, Issue 6 (June 2020)
Abstract
The internal combustion engine’s warm-up period is one of the most important sources of emissions, especially unburned hydrocarbons (UHC). Due to the low temperature of combustion chamber wall during the warm-up period, the flame is quenched rapidly near the walls and piston surface and the air-fuel mixture in the vicinity of the wall does not burn and leave the combustion chamber unburned which increases UHC emissions of internal combustion engines during the warm-up period. In the current study, using MATLAB R2018b software and numerical solution methods, a code is developed based on XU7 engine data to determine the effect of wall temperature on the flame quenching distance. The results showed that by increasing the cylinder wall temperature, flame quenching distance during the engine warm-up period, for two cases of constant and pressure based Peclet number, was decreased by 46 and 22%, respectively. The results also indicated that the flame quenching distance had a downward logarithmic behavior over time, which is the opposite of the thermal behavior of the combustion chamber walls during the engine warm-up period, which is an upward logarithmic behavior.
Volume 28, Issue 4 (1-2022)
Abstract
With the increasing hegemony of Britain over the Persian Gulf in the late 18th century and the early 19th century made it evident for the exclusion of opponents of this country in the region. At the same time, Britain became the main enemy since the Qasimi dynasty also called Qawasim, started expanding its naval fleet in the Strait of Hormuz, both for political and commercial reasons. The British Navy tried many times to destroy Ras al-Khaimah that was the main base for the Qawasim. Two such attacks carry greater significance, which were launched in 1809 and 1819. Their importance is due to the fact that the 1820 treaty played an important role in the history of the Persian Gulf as well as in the formation and independent Arab emirates off the southern coast of the Persian Gulf. In this article, with the historical studies approach, we seek to study the conflict over Ras al-Khaimah between 1809 and 1819 as well as the impact of two wars of 1809 and 1819 and subsequent agreement on historical transformation of the southern coast of the Persian Gulf and the fate of inhabitants there.
