Environmental Studies

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Browsing Environmental Studies by Author "Adnan Joudeh"

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    قياس الكثافة الظاهرية للتربة بإستخدام مطيافية أشعة جاما
    (AL-Quds University, 2008-05-10) الاء محمود عبد المنعم شحادة; Ala` Mahmoud Abd AL-Mune`m Shehadeh; عدنان اللحام; Adnan Joudeh; Musa Abu-Teir
    This study deals with a nuclear method of Gamma- Ray Backscattering Spectroscopy as a method that could be applied in measuring material bulk density specially soil density. The detection system consists of a 3” × 3” inch NaI(Tl) detector connected to multichannel analyzer Inspector 2000 from Canberra instruments and lap top computer. 137Cs is used as a Gamma-Ray emitter with energy of 662 KeV. Different soil types with different bulk densities are used in calibration process. Before applying this technology in the field, calibration process took place in order to find a relationship between material bulk density and the collected count rate for that material. Calibration measurements are performed using three different material with three different bulk densities filled in wooden boxes constructed specially for this purpose with dimensions of 59×42×34 cm. Gamma ray source is shielded to prevent direct gamma photons from reach the detector in direct way. The detector and shielded gamma-ray source are placed on the top of the material’s surface, and gamma ray spectrum for 137Cs is collected for measurement times of 60 seconds to prevent background radiation measurement and the elevation on instrument’s temperature which could lead to mistaken the measurement. Collected spectra are analyzed using Genie 2000 software. Count rates are calculated for each spectrum, then a calibration curve is found making it easy to find the mathematical relationship between the count rate and the bulk density. Field measurements of bulk density (BD) are performed to check the validity of the system calibration. Results of Terra Rossa soil were in very good agreement with the measurement density. iii Count Rate for the calibration process for Terra Rossa with 10 cm as a detector-source separation distance was (406 counts. s-1), in the Terra Rossa field with the same distance (430 counts.s-1 ). With using 20 cm, count rate in calibration process was (144 counts.s-1), in the field it was (141 counts.s-1), we can notice how much the measurements are closed., the count rate from energy range of (250-730 KeV). Measurement of bulk density are conducted in five different locations at Al-Quds University Main-Campus site. Results of there measurements are consistent relating to the type of soil and other materials present at the investigated locations. Field measurements also are performed to study the effect of rain on soil bulk density determination.