introduction: introduction: few studies have investigated the distribution of stress around implants. in this study the distribution of stress in bones around implants was investigated in five overdenture (od) treatment designs including od-1, od-2, od-3, od-4 and od-5. materials and methods: the catia modeling software was used in order to simulate the tooth/implant model and bone. first, the ...

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...

The present study examines the effects of historic climate variability on cold-season processes, including soil temperature, frost depth, and the number of frost days and freeze–thaw cycles. Considering the importance of spatial and temporal variability in cold-season processes, the study was conducted in the midwestern United States using both observations and model simulations. Model simulati...

This work develops a statistical model to assess the frost risk in Rafsanjan, one of the largest pistachio production regions in the world. These models can be used to estimate the probability that a frost happens in a given time-period during the year; a frost happens after 10 warm days in the growing season. These probability estimates then can be used for: (1) assessing the agroclimate risk ...

Abstract Permafrost and seasonally frozen ground are important surface features in highlatitudes. Because of this, a soil-frost parameterization was added to the Penn State University/NCAR mesoscale meteorological model MM5 in combination with the well validated hydro-thermodynamic soil vegetation scheme HTSVS, which takes into account among other things soil freezing and thawing. Reanalysis of...

A generalized model for secondary frost heave is developed based on the one-dimensional model of O'Neill and Miller. Secondary frost heave arises during freezing owing to cryostatic suction effects that can increase the upward water permeation to facilitate ice-lens growth and increased heave. Nondimensionalization and scaling are used to simplify the model equations and to identify a dimension...

Freezing stress is one of the most important limiting factors determining the ecological distribution and production of tree species. Assessment of frost risk is, therefore, critical for forestry, fruit production, and horticulture. Frost risk is substantial when hazard (i.e., exposure to damaging freezing temperatures) intersects with vulnerability (i.e., frost sensitivity). Based on a large n...

[1] Frost boils in the Arctic are a manifestation of patterned ground in the form of nonsorted circles. Active frost boils involve convection of water through the soil that can bring basic salts from depth to the surface. As such, active frost boils can mitigate acidification and thereby strongly influence the type of vegetation supported by Arctic soils. The presence or absence of active frost...

simultaneous heat and water model (shaw) is based on the assimilation rate of melting and/or freezing of the accumulated snow as well as melting of ice in soil. the main objective of this study was to evaluate applicability of shaw model in determining maximum depth of frost penetration in soils in some typical climates of iran. to this end, the daily data of air temperature, soil temperatures ...

Frost boils in northern Alaska vary from large, 2–3-m diameter, barren non-sorted circles to completely vegetated hummocks. Summer warmth increases southwards from the coast. Average thaw-layer thickness shows the opposite trend. Frost heave shows no trend along the climate gradient but is affected by soil texture. Heave is greatest on frost boils with fine-grained sediments. Biomass increases ...