background: lead-based radiation shields are widely used in radiology departments to protect both workers and patients from any unnecessary exposure to ionizing radiation. recently there has been a great deal of concern expressed about the toxicity of lead. human lead toxicity is well documented. in that light, production of environmentally-friendly lead-free radiation shields with less weight ...

Background: Lead-based radiation shields are widely used in radiology departments to protect both workers and patients from any unnecessary exposure to ionizing radiation. Recently there has been a great deal of concern expressed about the toxicity of lead. Human lead toxicity is well documented. In that light, production of environmentally-friendly lead-free radiation shields with less weight ...

Many delta systems worldwide are becoming increasingly urbanized following a variety of processes, including land reclamation, embanking, major engineering and port constructions, dredging more. Here, we trace the development one system, Rhine–Meuse in Netherlands (RMD) from two natural estuaries (the RME fed by Rhine river HVL Meuse river) to densely effect human activities have had on its mor...

Background: In recent years, there has been an increased interest toward non-lead radiation shields consisting of small-sized filler particles doped into polymer matrices. In this paper, we study a new polyvinyl alcohol (PVA)/WO3 composite in the presence of high-energy gamma photons through simulation via the Monte Carlo N-Particle (MCNP) simulation code. Materia...

Contrast-detail experiments were performed to optimize technique factors for the detection of low-contrast lesions using a silicon diode array full-field digital mammography (FFDM) system under the conditions of a matched average glandular dose (AGD) for different techniques. Optimization was performed for compressed breast thickness from 2 to 8 cm. FFDM results were compared to screen-film mam...

The purpose of this study was to empirically characterize and validate a kilovoltage (kV) X-ray beam source model of a superficial X-ray unit for relative dose calculations in water and assess the accuracy of the British Journal of Radiology Supplement 25 (BJR 25) percentage depth dose (PDD) data. We measured central axis PDDs and dose profiles using an Xstrahl 150 X-ray system. We also compare...

The performance requirements of the concrete of containment structures are mainly radiological protection, structural integrity and durability, etc. For this purpose, highperformance heavy density concrete with special attributes can be used. The aggregate of concrete plays an essential role in modifying concrete properties and the physico-mechanical properties of the concrete affect significan...

Americani. The Jensen (genetic) positioin on racial (lifferences in intelligence is well alnswered l)y PettigTew's consi(leration of environmental influences on intelligence ancl iintelligence testing (even tlhotuglh Pettigrew's article precdates the Jenseni controversy). Also consi(lere(d by Pettigrew is the social (lefinition of mental illness andl the impact of social class in creating al)pl...

The use of flat-panel detector (FPD) systems in TV equipment for gastrointestinal tract examination is increasing. The use of FPD systems is believed to reduce the exposure dose. When our institution changed its TV equipment from an image intensifier (GE;MS90Tj) system to an FPD (Shimadzu;SONIALVISION safire DAR-3500) system, we measured the doses produced and carried out a comparative examinat...