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Indoor radon concentrations in 33 dwellings in Arar city were measured using a CR-39 detector. This work is the first in the region and was done to assess the health risks. The exposure time was about 4 months, from May to September 2017. It was found that the indoor radon concentration changed in the range from 7.7 to 89.1 Bqm-3 with an overall average of 44.05 ± 6.21 Bqm-3 while the geometric mean is 39.51 Bqm-3 with a geometric standard deviation of 1.67. These values are within the acceptable level set by the International Committee for Radiation Protection. The annual effective dose received by the population of Arar was reported and it varied in the range 0.16 -1.82 mSv with an average value of 0.9 ± 0.16 mSv and the geometric mean is 0.81 mSv. The exposure to radon progeny was studied where the minimum, maximum, average, and geometric mean of exposure are 0.83×10-3, 9.63×10-3, 4.76 ± 0.67× 10-3 and 5.05×10-3 WLM, respectively. Finally, for the estimation of cancer risks, the excess lifetime cancer risk was investigated. Its average value was 3.7×10-3 which is relatively higher.

In this work, the radon exhalation rate, effective radium content and radiation doses from some groundwater wells in Najran City, Saudi Arabia, were addressed and discussed in detail. This survey of radon concentrations in the groundwater was carried out using the passive measurement technique, where the radon gas passively diffuses into the detector. The obtained results revealed that the radon exhalation rate in terms of area and mass exhibits linear correlations with effective radium in groundwater (correlation coefficient R2 = 1). Also, the majority of radon concentrations are within the UNSCEAR 1993 permitted level and the average annual effective doses obtained for radium and radon are 180 µSv and 860 µSv, respectively.

A single crystal of Zn2Te3O8 (ZTO) was grown using the conventional Czochralski technique. TGA analysis showed that the melting point of ZTO is 681 °C, while it exhibits a structural phase transition at 621 °C. The powder X-ray diffraction analysis of ZTO confirmed that it possesses a single crystalline monoclinic structure with the C2/c space group. An indirect band gap of 3.75 eV was estimated for the ZTO crystal based on its absorption spectrum. The X-ray-induced luminescence of the grown crystal comprised a broad band peaking at 565 nm, which can be tentatively assigned to the self-trapped exciton emission from the (Te3O8)4− molecular complexes. The photoluminescence measured under 280 nm excitation showed a broad band luminescence peaking at about 600 nm, and its intensity was significantly enhanced upon cooling the crystal from 300 K to 10 K. The photoluminescence decay time under 280 nm excitation was shown to have two exponential components in the range from 10 K to 175 K, which became a single exponential upon further heating the crystal. Low scintillation light was observed at room temperature both under α- and β-particle excitations from 241Am and 90Sr sources, respectively. The scintillation light yield measured under β-particle excitation from the 90Sr source was enhanced by about five orders of magnitude at 10 K in comparison to that at 300 K. The scintillation light yield measured at 10 K under the same experimental conditions for ZTO in comparison with the well-known cryogenic scintillator Li2MoO4 (LMO) was shown to have four times higher scintillation light. A single-crystal ingot of ZTO was obtained for the first time; however, it had several cracks due to its phase transition. Notably, scintillation at low temperatures for a Te-based crystal was observed for the first time. These preliminary findings are very promising and show that ZTO will be a good candidate for cryogenic phonon scintillation detectors for the 0νββ decay search of 130Te. [ABSTRACT FROM AUTHOR]

The semiconducting ZnS:Cl− nanoparticles coactivated with Y3+ ions were synthesized. The pure ZnS powders were prepared with conventional hydrothermal technique at 220 °C, activated with 25 mg/g NH4Cl and coactivated with various concentrations of Y3+ ions. The impurity atoms incorporated ZnS powders were sintered at 960 °C under Ar ambient. The powders X-rays diffraction (PXRD) analysis for the synthesized powders showed the formation of mixed ZnS phases, and some fraction of ZnO phase. The existence of O atoms was confirmed by energy-dispersive X-rays (EDX) techniques as well. The average particle sizes of the synthesized nanoparticles were found to be about 500 nm by field emission scanning electron microscopy (FE-SEM) analysis. At room temperature, the emission spectra for the samples had broadband with maximum at 470 nm with excitation of 345 nm. An enhancement in the luminescence intensity was observed with an increase in Y3+ coactivator concentration up to 0.1 mg/g that can be assigned to the decrease in the concentration of traps. With further increase in Y3+ concentration, the light yield quenched. The synthesized ZnS_Cl−_Y3+ nanoparticles can be applied for various applications, such as optoelectronics, scintillation, photocatalysis, and sensing. [ABSTRACT FROM AUTHOR]

Hand veins can be used effectively in biometric recognition since they are internal organs that, in contrast to fingerprints, are robust under external environment effects such as dirt and paper cuts. Moreover, they form a complex rich shape that is unique, even in identical twins, and allows a high degree of freedom. However, most currently employed hand-based biometric systems rely on hand-touch devices to capture images with the desired quality. Since the start of the COVID-19 pandemic, most handbased biometric systems have become undesirable due to their possible impact on the spread of the pandemic. Consequently, new contactless hand-based biometric recognition systems and databases are desired to keep up with the rising hygiene awareness. One contribution of this research is the creation of a database for hand dorsal veins images obtained contact-free with a variation in capturing distance and rotation angle. This database consists of 1548 images collected from 86 participants whose ages ranged from 19 to 84 years. For the other research contribution, a novel geometrical feature extraction method has been developed based on the Curvelet Transform. This method is useful for extracting robust rotation invariance features from vein images. The database attributes and the veins recognition results are analyzed to demonstrate their efficacy. [ABSTRACT FROM AUTHOR]

Problem statement: Image encryption needs to be secure by resisting statistical attacks and other types of attacks. Approach: The new algorithm, call it the Shuffle Encryption Algorithm (SEA), applies nonlinear s-box byte substitution. Then, it performed a shuffling operation partially dependent on the input data and uses the given key. Results: SEA was implemented and tested with different data, mainly consisting of images. Results confirmed its security, shown through statistical analysis using histograms, correlation and covariance. Conclusion: New algorithm was suited for encrypting images and other types of data. Key words: Cryptography, image encryption, s-box, rijndael, INTRODUCTION The study of cryptography has become increasingly important, as progressively more information is stored and transmitted in electronic form. This led to the creation of many encryption algorithms and [...]

A method of proof is presented and used in proving theorems in logic and set theory. Many commonly used methods of proof are rigid and not easy to apply in proving different theorems. This study deductively draws conclusions from rules of logical inference and then, it generalizes the deduction methods to be applied to logic and set theory. Then, it shows how this method of logical inference can be used to prove implications involving conjunction or disjunction of premises and to prove some identities in set theory involving implication or containment. Key words: Deductive inference, conjunction, disjunction, implication, containment, method, INTRODUCTION Logical inference aims at forming a conclusion based on some given premises. Generally, deductive inference involves conditional reasoning that follows the (if A then B) format to obtain valid [...]

The enlarged veins in the pampiniform venous plexus, known as varicocele disease, are typically identified using ultrasound scans. The medical diagnosis of varicocele is based on examinations made in three positions taken to the right and left testicles of the male patient. The proposed system is designed to determine whether a patient is affected. Varicocele is more frequent on the left side of the scrotum than on the right and physicians commonly depend on the supine position more than other positions. Therefore, the experimental results of this study focused on images taken in the supine position of the left testicles of patients. There are two possible vein structures in each image: a cross-section (circular) and a tube (non-circular) structure. This proposed system identifies dilated (varicocele) veins of these structures in ultrasound images in three stages: preprocessing, processing, and detection and measurement. These three stages are applied in three different color modes: Grayscale, Red-Green-Blue (RGB), and Hue, Saturation, and Value (HSV). In the preprocessing stage, the region of interest enclosing the pampiniform plexus area is extracted using a median filter and threshold segmentation. Then, the processing stage employs different filters to perform image denoising. Finally, edge detection is applied in multiple steps and the detected veins are measured to determine if dilated veins exist. Overall implementation results showed the proposed system is faster and more effective than the previous work. [ABSTRACT FROM AUTHOR]