نتایج جستجو برای: free lead composite shield
تعداد نتایج: 955098 فیلتر نتایج به سال:
OBJECTIVES This study was aimed to investigate the methods to reduce operator's radiation dose when taking intraoral radiographs with portable dental X-ray machines. MATERIALS AND METHODS Two kinds of portable dental X-ray machines (DX3000, Dexcowin and Rextar, Posdion) were used. Operator's radiation dose was measured with an 1,800 cc ionization chamber (RadCal Corp.) at the hand level of X-...
A structural and petrological study of the Late Proterozoic rocks in the Wadi Kid area, Sinai, Egypt indicates the presence of an extensional metamorphic core complex in the northern Arabian–Nubian Shield. Gneissic domes throughout the Arabian–Nubian Shield resemble the core complex of the Wadi Kid area and as a result, they are interpreted as extensional metamorphic core complexes. The presenc...
In this study, a mixture of waste lead mine Nakhlak and cement with different percentages of boric acid are used to construct a proper shield for gamma and neutron radiations emitted from the Am-Be source. Neutron dose rate reduction by the prepared samples was investigated by thermal neutron irradiation system of Isfahan University, TLD 600 and TLD 700. Neutron dose rate changes, compressive...
The count rate performance of the single LSO crystal layer high-resolution research tomograph (HRRT-S) PET scanner is limited by the processing speed of its electronics. Therefore, the feasibility of using an in-field-of-view (in-FOV) shield to improve the noise equivalent count rates (NECR) for small animal brain studies was investigated. The in-FOV shield consists of a lead tube of 12 cm leng...
various aldoximes and ketoximes synthesis of corresponding aldehydes and ketones in the presence of sio2@feso4 nano composite as recoverable nano catalyst and nh2oh·hcl. the sio2@feso4 nano composite system was carried out between 10 to 15 min in oil bath (70-80 °c) under solvent-free condition in excellent yields in addition this protocol can be used for industrial scales. this method offers s...
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