Study of physical and chemical characteristics of dust storms in Iran is necessary. In this regard, 10 samples from Khozestan dust storms in 1387 and 1388 were collected for XRD and SEM studies. XRD result show that mineralogical composition of these dust particles can be divided into three groups: (1) Carbonate group (calcite mineral), (2) Silicate group (quartz mineral) and (3) Clay group (Ka...

Background and objectives: Dust storm is a natural event that occurs in arid and semi-arid and There are many adverse consequences. according to the increased number and duration of dust storms and their effects on the environment and human health, present article is to Analysis of dust and dust storms in Iran,Investigation Internal and external origin of dust storms in Iran using sate...

abstract cooperative learning refers to small groups of learners working together as a team to solve a problem, complete a task, or accomplish a common goal. in a cooperative environment one’s success is directly related to the success of other members because the focus on the individual shifts towards the group. to test the effectiveness of the method, using jigsaw technique, a study was cond...

abstract type-ii fuzzy logic has shown its superiority over traditional fuzzy logic when dealing with uncertainty. type-ii fuzzy logic controllers are however newer and more promising approaches that have been recently applied to various fields due to their significant contribution especially when the noise (as an important instance of uncertainty) emerges. during the design of type- i fuz...

abstract pragmatics is the study of communicative action in its sociocultural context. communicative action includes not only using speech acts (such as apologizing, complaining, complimenting, and requesting), but also engaging in different types of discourse and participating in speech events of varying length and complexity. the present study aimed to investigate the assessment of pragm...

hedging is a multi-purpose rhetorical strategy which is usually used in scientific arguments to secure ratification of claims, reduce the risk of negation, avoid conflict, manage disagreement and leave room for the audience to assess presented information. hedges are frequently used in research articles to mitigate the findings of research endeavors. the present research aims to investigate the...

in reality, most structures involved in geotechnical engineering are three dimensional in nature, and although in many, plane strain or axisymmetric approximations are reasonable, there are some, for which 3-d treatment is required. the quantity of data, and the size of the various vectors and matrices involved in such analysis, increase dramatically. this has sever implications for computer r...

during natural gas processing, water in natural gas may cause to hydrates formation in pipelines which may lead to serious damages to process equipments. given the problems raised by present of water in natural gas, glycol solvent uses to remove water.in contact of glycol with gas always an amount of btex and voc absorb along with water, which on glycol recovery process, these substances separa...

Background and Objectives: The dust pollution in the air of cities is one of the environmental problems in the western and southwestern regions of Iran, which can have many effects on the environment and human life. The purpose of this study is the assessment of dust pollution, the effect of climatic parameters on it and the field of view in the southwestern regions of Iran. Methods: In this st...