sand and dust storms are natural events that occur widely around the world, mostly in dry and bare lands. over thepast decade a large part of iran has been affected by this phenomenon, and tehran has not been excluded from thisevent. therefore, having knowledge of spatiotemporal frequency variations can aid us in future management andstorm trajectory assessment. in this study the synoptic anemo...

Frost heave, which is the volumetric expansion of frozen soil, has great ecological significance, since it creates water storage spaces in soils at the beginning of the growing season in cold temperate forests. To understand the characteristics of frost heave in seasonally frozen soil and the factors that impact its extent, we investigated the frost heave rates of forest soil from different dep...

We used field observations of frost-boil distribution, soils, and vegetation to attempt to validate the predictions of a Differential Frost Heave (DFH) model along the temperature gradient in northern Alaska. The model successfully predicts order of magnitude heave and spacing of frost boils, and can account for the circular motion of soils within frost boils. Modification of the model is neede...

background: healthcare-associated infections such as nosocomial infections (ni) are important causes of mortality worldwide. objectives in this study we evaluated the nosocomial infections terms of microbiology (resistance, culturing, etc.) in a referral pediatric hospital based on national nosocomial infection surveillance system. patients and methods in an epidemiological surveillance study d...

Frost formation on an evaporator causes significant problems by decreasing inlet air flow. It is important for a precise prediction to understand the dominant factor of the frost formation. In this paper, the frost layer on the cold plate is experimentally obtained with different velocities while maintaining a surface temperature at -20 degrees Celsius. The mass and height of the frost layer is...

[1] In mountainous landscapes the role of periglacial processes in producing sediment is poorly defined, despite evidence of abundant talus slopes. Ice growth in rock has long been recognized as an efficient erosion mechanism, but the effects have not been readily applied to landscape evolution in response to tectonic and climatic forcing. Here, we quantify how and where ice-driven mechanical e...