the use of heavy machinery in forestry operations such as logging has increased worldwide during the last decades. however, these machines may seriously influence the soil ecosystem as they induce rutting, disturbing the upper soil layers, and soil compaction. severe compaction of soil adversely affects the growth of plants.this study was done by using a penetration resistance experiment in a g...

Crater depth is a vital issue in dynamic compaction (DC) because it controlling parameter DC and characterization index of soil properties. A continuous mathematical model capturing the time-domain process tamper displacement presented this paper. The simple parameters involved are easy to obtain. It was found that accumulated crater increases but its increment decreases with multiple impacts. ...

During eukaryotic evolution, genome size has increased disproportionately to nuclear volume, necessitating greater degrees of chromatin compaction in higher eukaryotes, which have evolved several mechanisms for genome compaction. However, it is unknown whether histones themselves have evolved to regulate chromatin compaction. Analysis of histone sequences from 160 eukaryotes revealed that the H...

A software for soil compaction analysis (SCAN) has been developed for evaluating the compaction states using the data from the GPS as well as a compactometer attached on the roller. The SCAN is distinguished from other previous software for intelligent compaction (IC) in that it can use the results from various types of GPS positioning methods, and it also has an optimal structure for remotely ...

This paper describes finite element analysis of compaction for dry textiles during preform manufacture. The models are generated using procedures encompassed in our TexGen textile modeling schema. Meshing and material property allocations are performed automatically, including definition of material orientations for each of the elements. Tow elements are modeled using a transverse isotropic mod...

We have built and operated an ultra-wideband UHF pulsed-chirp radar for measuring firn stratigraphy from airborne platforms over the ice sheets of Greenland and West Antarctica. Our analysis found a wide range of capabilities, including imaging of post firn–ice transition horizons and sounding of shallow glaciers and ice shelves. Imaging of horizons to depths exceeding 600m was possible in the ...

OBJECTIVES The aim of this study was to evaluate the sealing ability of lateral compaction and tapered single cone gutta-percha techniques in root canals prepared with stainless steel and rotary nickel titanium root canal instruments by fluid filtration method. STUDY DESIGN The root canals were prepared with stainless steel (SS) and nickel titanium (NiTi) instruments. The canals prepared with...

soil is a nonrenewable source that needs considerable management to prevent physical deteriorationby erosion and compaction. compacted soil causes low fertility and yield. the purpose of this study isto investigate the effect of viscoelastic properties of soil and to determine important factors oncompaction. furthermore, stress distribution, prediction of soil compaction and simulation of its e...