in different regions, precipitation takes place with different persistencies and every persistency supplies a share of rainfall days and precipitation. therefore, the importance of rainfall persistence could be evaluated in all places. iran is located in mid-latitude of an arid region, in which the mean rainfall is 250 mm and it has dramatic tempo-spatial changes. rainfalls with short persisten...

Aim: Calcium silicate cements are widely used in endodontics. Novel fast-setting calcium silicate cement with fluoride (Protooth) has been developed for potential applications in teeth crowns including cavity lining and cementation. Objective: To evaluate the surface apatite-forming ability of Protooth compositions as a function of fluoride content and immersion time in phosphate-buffered salin...

abstract drastic precipitations in unmorally times always are one of the important factors that created abundant damages in different geographical areas. in this research, three precipitations that occurred in summer 2009 in mashhad were investigated. the investigation of variation graphs of meteorological parameters show significant decreasing of air pressure and temperature and increasing of ...

This paper proposed an efficient approach, for weather Radar image classification and filtering, which is based on the combination of the textural analysis and support vector machine (SVM). Since the images are formed by two kinds of echoes, precipitations (rainfalls) and ground echoes (clutter), caused by earth's surface, thus, our purpose is to preserve precipitations and eliminate ground ech...

A large quantity of world’s oil reserves exists in carbonate reservoirs. Carbonate reservoirs are very sensitive to chemical enhanced oil recovery process because of containing large amount of calcite, dolomite and calcium sulfate minerals. These minerals cause major obstacles during alkali-surfactant-polymer (ASP) flooding. Alkali reacts with these minerals and form undesired precipitations wh...

Climate is complex ecological factor described by different climate elements and phenomena that effect development of vegetation and its natural distribution. Climate elements the most important for vegetation are air temperatures, amount of precipitations, air humidity and wind. The aim of this research was to determine trends and changes of climate elements in the region of Mediterranean Croa...

To assess the potential for carry-over of loblolly pine (Pinus tuedu L.) and shortleaf pine (Pinus echinatu Mill.) seeds from one year to the next, seed viability was determined by germination tests following field storage for up to 21 months. Treatments included seeds stored (i) in a freezer, (ii) on the forest floor, (iii) 1.8 m above the forest floor and exposed to precipitation, and (iv) 1....

We separated dust particles from the mesh-filtered sets of rainwaters collected on rainy days with daily precipitations exceeding 10 mm per day. A total of 136 rainwaters (or snow during the winter season) samples collected from February 2009 to February 2013 were analyzed. In particular, 33 out of 136 rainwaters were collected during or just after the Asian dust storm (ADS) events. Values of p...