any change in the refractive index of a laser active medium can lead to serious degradation of beam quality, laser beam modes, laser performance and variation in the intensity distribution. alteration in the refractive index of laser active medium is especially notable in high power lasers. it is clear that in the laser beam production, the pumping agent induces a great amount of heat which...

abstract the influence of cation?? and anion?? interactions on the strength and nature of n…h hydrogen bond has been investigated by quantum chemical calculations in s-triazine…3hf complex. ab initio calculations were performed at mp2/6-311++g(d,p) level of theory. the natural bond orbital (nbo) analysis and the bader’s quantum theory of atoms in molecules (aim) were also used to elucidate t...

this thesis attempts to investigate the effects of prelistening activities on enhancing iranian efl learners` listening comprehension. the present study investigated ways in which learners` background knowledge could be activated in order to enhance their l2 listening comprehension by limiting the number of possible text interpretations prior to listening. the experiments conducted in this stud...

This study was conducted to evaluate the quantitative and qualitative characteristics and grain yield stability of 10 promising lines of rice, compared to cultivar Khazar as the checking variety, in Rasht, Roudsar and Talesh cities of Guilan province, Iran, in three years. The experiment was conducted using a randomized complete block design with three replications. Characteristics such as grai...

Rice provides food for more than half of the world's population. Unlike other cereals used in the form of processed, rice is mostly consumed directly with removal of paddy and brown husks. Therefore, considering rice grain quality is one of the main factors in product marketability and consumption. Rice grain quality can be considerd and evaluated by assessment of four properties: physical, che...

in this research the focus of the researcher is on the influence of american myths that have long been held and offered by the american culture and ideologies. sam shepard is conceived to be one of the greatest playwrights of the contemporary american theater. in his works he depicts broken characters who are struggling to keep up with the national expectations but are ceaselessly borne back to...