Current Issue : April - June Volume : 2021 Issue Number : 2 Articles : 5 Articles
Igneous and sedimentary rocks contain an amount of natural radioactivity (NORM). U-238, Th-232 and their decay products, and K-40 are important sources of gamma-radiation. Knowledge of the radionuclide content of rocks is necessary to estimate the exposure of the population to the radiation. Many types of rocks are used in building and industries, thus the radiation detection is important, it provides a baseline map of levels of the radioactivity in the study region. The purpose of this study is to evaluate the activity concentrations of the natural radionuclides (U-238 (Ra-226), Th-232 and K-40) and the fallout nuclide (Cs-137) (if found) in thirty samples of igneous and sedimentary rocks of Al-Atawilah (Al-Baha). The samples were collected and prepared during 2018/2019, and analyzed with a good experimental instrument (High energy resolution γ-ray spectroscopy with HPGe detector), also these rock samples were analyzed with X-ray fluorescence to subdivided these rocks based on the major oxides proportions contained of each sample. The mean activity concentrations of naturally radionuclides were found in the igneous rock samples varied depending on the type of the igneous rock. For sedimentary rock samples, the activity concentrations were found high for quartz sandstone sample, which may be due to its high proportion of SiO2 and K2O. The estimated mean values of absorbed dose rate are within the permissible limit value. The findings indicate high dose level values in granite (rhyolite) and most of diorite (andesite) igneous rock samples while gabbro (basalt) igneous rock samples (except for one sample) record low levels of dose rate. All sedimentary rock samples have low dose rate (except for the quartz sandstone sample)....
Scoliosis is a three-dimensional trunk and spinal deformity. Patient evaluation is essential for the decision-making process and determines the selection of specific and adequate treatment. The diagnosis requires a radiological evaluation that exposes patients to radiation. This exposure reaches hazardous levels when numerous, repetitive radiographic studies are required for diagnostics, monitoring, and treatment. Technological improvements in radiographic devices have significantly reduced radiation exposure, but the risk for patients remains. Optical three-dimensional surface topography (3D ST) measurement systems that use surface topography (ST) to screen, diagnose, and monitor scoliosis are safer alternatives to radiography. The study aimed to show that the combination of plain X-ray and 3D ST scans allows for an approximate presentation of the vertebral column spinous processes line in space to determine the shape of the spine’s deformity in scoliosis patients. Twelve patients diagnosed with scoliosis, aged 13.1 ± 4.5 years (range: 9 to 20 years) (mean: Cobb angle 17.8◦, SD: ±9.5◦) were enrolled in the study. Patients were diagnosed using full-spine X-ray and whole torso 3D ST. The novel three-dimensional assessment of the spinous process lines by merging 3D ST and X-ray data in patients with scoliosis was implemented. The method’s expected uncertainty is less than 5 mm, which is better than the norm for a standard measurement tool. The presented accuracy level is considered adequate; the proposed solution is accurate enough to monitor the changes in the shape of scoliosis’s spinous processes line. The proposed method allows for a relatively precise calculation of the spinous process lines based on a three-dimensional point cloud obtained with a four-directional, three-dimensional structured light diagnostic system and a single X-ray image. The method may help reduce patients’ total radiation exposure and avoid one X-ray in the sagittal projection if biplanar radiograms are required for reconstructing the three-dimensional line of the spinous processes line....
As a natural two-dimensional nanomaterial, palygorskite has been widely used in the fields of biology, chemical industry, medicine, and agriculture. Recently, more and more researchers point out that the aspect ratio of palygorskite directly affects the properties of its composite materials. Due to the large specific surface area and the tiny width of the palygorskite rod-like particles, it is difficult to obtain the aspect ratio information quickly and accurately by conventional means such as microphotography method and specific surface area method. In this paper, the length and width of the crystal is measured quickly and accurately by using dynamic laser light scattering technique and X-ray diffraction technique, so that the aspect ratio of the crystal can be calculated easily. It is recommended to analyze the crystallite size and microstrain of the diffraction pattern of palygorskite that using Pearson VII function, Caglioti equation, and average (LANGFORD) method, after comparing the three modes of W.-H. method. This feasible method has a good application prospect of the study of rod-like nanomaterials....
In this research, we investigate the interaction of X-rays with a capacitor by studying the voltage established in the capacitor during the illumination. Motivation: We aim at verifying that the total energy conserved in the interaction is Pτ, i.e. the product of the average power P times the period τ of the X-rays. Hypothesis: Our investigation relies on the hypothesis that the voltage responsivity πV of the capacitor should be small, according to previous research. The parameter πV is the ratio between the voltage produced and the average power P of the X-rays, and measures the performance of the capacitor in response to the X-rays. Method: We measure the voltage produced by the capacitor in response to the X-rays, and then determine the average power P of the X-rays according to a procedure already assessed with infrared and visible light. Results: In our experiments, P turns out to be in the range between 10−3 W to 100 W. Our procedure enables us to unveil the relationship between the average power P and the effective dose, an important operating parameter used to measure the delivery of X-rays in practical applications, such as standard X-ray medical imaging machines. Conclusions: We believe that our procedure paves the way for designing a possible X-ray power-meter, a tool presently missing in the market of X-ray characterization tools....
Dietary supplements may contain heavy metals with the property of bioaccumulation in humans. The aim of this research was to validate and apply two analytical methods to determine Pb, As, Cr, and Hg in dietary supplements by Total Reflection X-ray Fluorescence Spectroscopy (TXRF). Methods validation was conducted through a multivariate analysis using a central composite design (CCD) and a desirability function. Critical values for each study variable were established. The TXRF_DS_1 method was proposed for Pb, As, and Cr determinations, while the TXRF_DS_2 was established for Hg analysis. The digestion method with an acid mixture (HNO3 + HCl +H2O2) was used to break down the organic material of dietary supplements. A solution of 10 μgL−1 Ga was used as an internal standard. Excellent analytical performance was obtained as LODs of 0.59, 0.41, 0.57, and 0.75 μgL−1 and LOQs of 1.95, 1.35, 1.90, and 2.50 μgL −1 for Pb, As, Cr, and Hg, respectively. Calibration curves showed a good linearity for all elements (R2>0.999). Excellent accuracy and precision in measurements (% RSD) was achieved. The real and spiked samples analysis demonstrated the applicability of the TXRF technique (percentage recovery 91–108%). Besides, two samples were analyzed in a comparison study between the TXRF_DS_1 method and the ICP-OES method. The results obtained showed good agreement between both techniques. The TXRF technique allows the analysis of toxic heavy metals in dietary supplements, which are marketed in a wide variety of presentations....
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