نتایج جستجو برای: compaction

تعداد نتایج: 9556  

ژورنال: علوم آب و خاک 2008
طهماسبی, منا , مصدقی, محمدرضا , همت, عباس , وفاییان, محمود ,

For prevention of soil compaction, knowledge of allowable compression stress limit (compaction strength) in soil is important. Pre-compaction stress ( σpc) was introduced as soil compaction strength and often used as a criterion for evaluation of soil susceptibility to compaction. In this research, pre-compaction stress was measured for a sandy loam soil with plate sinkage (PST) and confined co...

Withdrawal of oil and gas from reservoirs causes a decrease in pore pressure and an increase in effective stress which results to a reservoir compaction. Reservoir compaction will result in surface subsidence through the elastic response of the subsurface. Usually in order to determine the subsidence above a hydrocarbon field, the reservoir compaction must be first calculated and then the effec...

Journal: :مدیریت خاک و تولید پایدار 0
رضا حسن پور دانشگاه تبریز محمدرضا نیشابوری استاد دانشگاه تبریز داود زارع حقی استادیار دانشگاه تبریز

this research was performed to investigate the combined effect of soil salinity and compaction on some physiological characteristics of corn. for this purpose a factorial pot experiment on the basis of completely randomized design with three replications was performed. the experimental factors were three levels of soil salinity (saturated paste extract electrical conductivity 1.5, 2.5 and 4.5 d...

طهماسبی, منا , مصدقی, محمدرضا , همت, عباس , وفاییان, محمود ,

For prevention of soil compaction, knowledge of allowable compression stress limit (compaction strength) in soil is important. Pre-compaction stress ( σpc) was introduced as soil compaction strength and often used as a criterion for evaluation of soil susceptibility to compaction. In this research, pre-compaction stress was measured for a sandy loam soil with plate sinkage (PST) and confined co...

Methods of preparing test specimens in laboratories are particularly important. It also holds true in terms of compaction procedure in predicting pavement performance. The currently available laboratory compactor cannot adequately replicate field compaction conditions, especially the Stone Mastic Asphalt (SMA) mixture. The essential element of SMA mixture comprises of stones that are placed nex...

2015
Yunshan Han Yanli Dong Yuanlong Wang Wei Duan Weihua Qin

To investigate the dynamic compaction mechanism of loess-filled embankment, a computational model of unit volume compaction effort was proposed as compared with the compaction test. The energy level of dynamic compaction used in actual projects was also considered. The differences between the compaction test and the unit volume compaction effort in the actual projects were studied. And also, th...

Journal: :journal of agricultural science and technology 2010
m. loghavi m. r. khadem

development of sensors to detect the location and depth of hard pans in real time is a major restriction on the application of site specific crop management (sscm). in this study, a soil compaction profile sensor equipped with four horizontal operating penetro-meters for on-the-go sensing and mapping of the location and intensity of hard pans arti-ficially formed in a soil bin was developed and...

ژورنال: علوم آب و خاک 2012
مهدی خوشخو‌, , سید محمدعلی زمردیان, ,

Internal erosion is the second major reason for earth dam's failure after overtopping. One of the effective factors in internal erosion in earth dams is the clay minerals used in dams as well as the effects of compaction efforts on soil in sample preparation. In this research, internal erosion and the effect of clay minerals and compaction effort on internal erosion were investigated. For this ...

2015

Compaction is a mechanical process in which an earthen material is made more dense. The densification occurs as a direct result of the mechanical loading, and is essentially complete at the end of the loading. Volume changes are incurred as a result of a reduction in the quantity of air voids— water content remaining constant. Since it is impractical to squeeze out all the air, the as-compacted...

Journal: :journal of dentistry, tehran university of medical sciences 0
mohsen aminsobhani assistant professor, dental research center, dentistry research institute, department of endodontics, faculty of dentistry, tehran university of medical sciences, tehran, iran ; school of dentistry, aja university of medical sciences, tehran, iran. abdollah ghorbanzadeh assistant professor, dental research center, dentistry research institute, department of endodontics, faculty of dentistry, tehran university of medical sciences, tehran, iran. mohammad reza sharifian assistant professor, dental research center, dentistry research institute, department of endodontics, faculty of dentistry, tehran university of medical sciences, tehran, iran. sara namjou postgraduate student, department of endodontics, school of dentistry, tehran university of medical sciences, tehran, iran. mohamad javad kharazifard epidemiologist, dental research center, dental school, tehran university of medical sciences, tehran, iran.

the aim of this study was to introduce modified continuous wave compaction (mcwc) technique and compare its obturation quality with that of lateral compaction (lc), warm vertical compaction (wvc) and continuous wave compaction techniques (cwc). the obturation time was also compared among the four techniques.sixty-four single-rooted teeth with 0-5° root canal curve and 64 artificially created ro...

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