assessment and management of the environmental impacts of forest harvesting operations have become increasingly critical factors in practicing commercial forestry. this study investigated soil disturbance from a forest logging system operation on an 8-hectare mixed broadleaved stand in compartment no. 309 in gorazbon district in kheyrud educational and research forest. the objective of this stu...

Let P be a set of n objects on a square grid. A push is a transformation of P that involves sweeping a horizontal or vertical line by one unit, starting from the hull of P , displacing objects in the direction of the sweep. For example, when pushing to the right, all the leftmost objects are displaced one unit to the right. This in turn displaces other objects further right. Given P , we want t...

Compaction in reactive porous media is modelled as a reaction-diffusion process with a moving boundary. Asymptotic analysis is used to find solutions for the coupled nonlinear compaction equations, and a traveling wave solution is obtained above the reaction zone.

abstract soil compaction is a main factor that reduces the cane yield in sugarcane fields, in southwest of iran, especially in ratoon cropping system. therefore, sub-soiling practices could alleviate adverse effects of compaction and increased yield. in according to this aim, a study was to evaluate the effect of  ratooning practice systems consisting of control (no subsoiler), two and four sha...

self-compacting concrete (scc) is a highly fluid yet stable concrete that can flow consistently under its own weight, pass between bars, and fill in formwork without the need of compaction. the application of scc effectively resolves the difficulties of concreting in situations with complicated formwork and congested reinforcements. in this paper, the bond between scc and steel reinforcement wa...

In this paper, we present a modified density-dependent Drucker-Prager Cap (DPC) model with a nonlinear elasticity law developed to describe the compaction behavior of pharmaceutical powders. The model is implemented in ABAQUS with a user subroutine. Using microcrystalline cellulose (MCC) Avicel PH101 as an example, the modified DPC model is calibrated and used for finite element simulations of ...

Warm compaction is a process leading to parts with high green strength and density. An increased compacting temperature lowers the flow stress of the metallic particles and increases their ductility, resulting in higher powder compressibility and stronger interparticles bonding, either mechanical or metallurgical. Although many studies have been published on warm compaction, very few investigat...

While measurements of ice-sheet surface elevation change are increasingly used to assess mass change, the processes that control the elevation fluctuations not related to ice-flow dynamics (e.g. firn compaction and accumulation) remain difficult to measure. Here we use radar data from the Thwaites Glacier (West Antarctica) catchment to measure the rate of thickness change between horizons of co...

Introduction: Compaction of bone to create a cavity for a total joint implant is gaining recognition as a bone-saving alternative to methods of cavity preparation that involve only extraction of bone. Advantages of compaction are increased contact area at the implant-bone interface and subsequent improved initial fixation and potential for bone ingrowth. Rasping and drilling are bone extraction...