104 research outputs found

    Solar Chimney Power Plants: A Mini Review

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    The main investigations of a novel solar thermal application known as SCPP are summarized in this paper. It is a method of producing electricity from solar energy that relies on the fact that air rises when it is heated. An adequate position within a tall chimney can be utilized to position a turbine to turn it, creating an updraft that can be used to generate power. This system\u27s specifications, design, construction, and use are all covered in the paper along with experimental and analytical research related to it. It also emphasizes the development and execution of SCPP programs

    Radiological Hazard Evaluation of Some Egyptian Magmatic Rocks Used as Ornamental Stone: Petrography and Natural Radioactivity

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    Magmatic rocks represent one of the most significant rocks due to their abundance, durability and appearance; they can be used as ornamental stones in the construction of dwellings. The current study is concerned with the detailed petrography and natural radioactivity of seven magmatic rocks. All are commercial granitic rocks and are identified as black Aswan, Nero Aswan, white Halayeb, Karnak, Verdi, red Hurghada and red Aswan. Their respective mineralogical com-positions are classified as porpheritic granodiorite, granodiorite, tonalite, monzogranite, syenogran-ite, monzogranite and syenogranite. A total of nineteen samples were prepared from these seven rock types in order to assess their suitability as ornamental stones. Concentrations of 226Ra, 232Th and 40K radionuclides were measured using NaI (Tl) scintillation gamma-ray spectrometry. Among the studied magmatic rocks, white Halayeb had the lowest average values of226Ra (15.7 Bq/kg),232Th (4.71 Bq/kg) and40K (~292 Bq/kg), all below the UNSCEAR reported average world values or rec-ommended reference limits. In contrast, the other granitic rocks have higher values than the recom-mended limit. Except for the absorbed dose rate, other radiological hazard parameters including radium equivalent activity, annual effective dose equivalent, external, and internal hazard indices reflect that the White Halyeb rocks are favorable for use as ornamental stone in the construction of luxurious and high-demand residential buildings. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.Funding: We deeply acknowledge Taif University for supporting the researchers through Taif University Researchers Supporting Project number (TURSP-2020/287), Taif University, Taif, Saudi Arabia

    Assessing geochemical and natural radioactivity impacts of Hamadat phosphatic mine through radiological indices

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    The utilization of phosphorite deposits as an industrial resource is of paramount importance, and its sustainability largely depends on ensuring safe and responsible practices. This study aims to evaluate the suitability of phosphorite deposits for industrial applications such as the production of phosphoric acid and phosphatic fertilizers. To achieve this goal, the study meticulously examines the geochemical characteristics of the deposits, investigates the distribution of natural Radioactivity within them, and assesses the potential radiological risk associated with their use. The phosphorites are massive and collected from different beds within the Duwi Formation at the Hamadat mining area. They are grain-supported and composed of phosphatic pellets, bioclasts (bones), non-phosphatic minerals, and cement. Geochemically, phosphorites contain high concentrations of P2O5 (23.59-28.36 wt.%) and CaO (40.85-44.35 wt.%), with low amounts of Al2O3 (0.23-0.51 wt.%), TiO2 (0.01-0.03 wt.%), Fe2O3 (1.14-2.28 wt.%), Na2O (0.37-1.19 wt.%), K2O (0.03-0.12 wt.%), and MnO (0.08- 0.18 wt.%), suggesting the low contribution of the detrital material during their deposition. Moreover, they belong to contain enhanced U concentration (55-128 ppm). They are also enriched with Sr, Ba, Cr, V, and Zn and depleted in Th, Zr, and Rb, which strongly supports the low detrital input during the formation of the Hamadat phosphorites. The high Radioactivity of the studied phosphorites is probably due to the widespread occurrence of phosphatic components (e.g., apatite) that accommodate U in high concentrations. Gamma spectrometry based on NaI (Tl) crystal 3×3 has been used to measure occurring radionuclides in the phosphorite samples. The results indicate that the radioactive concentrations' average values of 226Ra, 232Th, and 40K are 184.18±9.19, 125.82±6.29, and 63.82±3.19 Bq Kg-1 , respectively. Additionally, evaluations have been made of the radiological hazards. The calculated risk indicators exceeded the recommended national and world averages. The data obtained will serve as a reference for follow-up studies to evaluate the effectiveness of the Radioactivity of phosphatic materials collected from the Hamdat mine area. © 2023 Fathy et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

    Radiological Hazards and Natural Radionuclide Distribution in Granitic Rocks of Homrit Waggat Area, Central Eastern Desert, Egypt

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    Natural radioactivity, radiological hazard, and petrological studies of Homrit Waggat granitic rocks, Central Eastern Desert, Egypt were performed in order to assess their suitability as ornamental stone. On the basis of mineralogical and geochemical compositions, Homrit Waggat granitic rocks can be subdivided into two subclasses. The first class comprises granodiorite and tonalite (I-type) and is ascribed to volcanic arc, whereas the second one includes alkali-feldspar granite, syenogranite, and albitized granite with high-K calc alkaline character, which is related to post-orogenic granites.238 U,226 Ra,232 Th, and40 K activities of natural radionuclides occurring in the examined rocks were measured radiometrically using sodium iodide detector. Furthermore, assessment of the hazard indices—such as: annual effective dose (AED) with mean values (0.11, 0.09, 0.07, 0.05, and 0.03, standard value = 0.07); gamma radiation index (Iγ) with mean values (0.6, 0.5, 0.4, 0.3, and 0.14, standard value = 0.5); internal (Hin) with mean values (0.6, 0.5, 0.4, 0.3, and 0.2, standard value = 1.0); external (Hex) index (0.5, 0.4, 0.3, 0.24, and 0.12, standard value = 1.0); absorbed gamma dose rate (D) with mean values (86.4, 75.9, 53.5, 43.6, and 20.8, standard value = 57); and radium equivalent activity (Raeq) with mean values (180, 154, 106.6, 90.1, and 42.7, standard value = 370)—were evaluated with the knowledge of the natural radionuclides. The result of these indices falls within the acceptable worldwide limits. Therefore, we suggest that these rocks are safe to be used in industrial applications. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.RF 3621/2021The researcher (Hamdy A. Awad) is funded by a scholarship under the Joint Executive Program between Egypt and Russian Federation. The work of the author A.E. and the APC were funded by the “Dunarea de Jos” University of Galati, Romania and grant no. RF 3621/2021

    Radiological Risk Parameters of the Phosphorite Deposits, Gebel Qulu El Sabaya: Natural Radioactivity and Geochemical Characteristics

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    This study investigates the distribution of natural radioactivity and geological, geochemical, and environmental risk assessments of phosphorite deposits to determine their suitability for international applications (such as phosphoric acid and phosphatic fertilizers). The examined Late Cretaceous phosphorite deposits belong to the Duwi Formation, which is well exposed on the southern scarp boundary at the central part of Abu Tartur Plateau, Gebel Qulu El Sabaya, East Dakhla Oasis. This formation is classified into lower phosphorite, middle shale, and upper phosphorite members. The lower phosphorite ranges in thickness from 2 to 3.5 m and mainly comprises apatite (possibly francolite), dolomite, calcite, quartz, hematite, anhydrite, and kaolinite. They contain an average concentration of CaO (38.35 wt.%), P2O5 (24.92 wt.%), SiO2 (7.19 wt.%), Fe2O3 (4.18 wt.%), MgO (3.99 wt.%), F (1.59 wt.%), Al2O3 (1.84 wt.%), Na2O (1.33 wt.%), and K2O (0.22 wt.%). Natural radioactivity and radiological parameters were investigated for fifteen samples of phosphorites using a NaI (Tl) scintillation detector. Absorbed dose rates, outdoor and indoor annual effective dose, radium equivalent activity, external and internal hazard, and excess cancer risk values are higher than the recommended levels, reflecting that exposure to these deposits for a long time may lead to health risks to human organs. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.Dunarea de Jos” University of GalatiPrincess Nourah Bint Abdulrahman University, PNU, (PNURSP2022R32)Acknowledgments: The authors would like to express their gratitude to Princess Nourah bint Abdulrahman University Researchers Supporting Project (grant no. PNURSP2022R32), Princess Nourah bint Abdulrahman University, Riyadh, Saudi Arabia. The author A.E acknowledges the support of “Dunarea de Jos” University of Galati, Romania

    Physico-mechanical properties and shielding efficiency in relation to mineralogical and geochemical compositions of Um Had granitoid, Central Eastern Desert, Egypt

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    The current work aims to describe the physico-mechanical characteristics and shielding efficiency with reference to the mineralogical and geochemical compositions of the Neoproterozoic Um Had composite granitoid pluton in order to deduce their favorability as dimension stones. The Um Had granitoid pluton has an elliptical outline with a mean diameter of about 10 km. This pluton is a composite (ranging from white to reddish pink color), hard, massive, and medium- to coarse-grained granitoid body. It is classified as syenogranite according to their modal and bulk chemical compositions. Geochemically, the granitoid pluton is a highly calc-alkaline, peraluminous granite, formed by low degree partial melting of tonalitic source rock in a post-collisional tectonic setting. The physico-mechanical properties of the granitoid pluton under study satisfy the requirements of dimension stone in terms of their bulk density (from 2561 to 2564 kg/m3), and to some extent water absorption capacity (from 0.38% to 0.55%). However, their compressive strength values (50.4–113.4 MPa) do not achieve the minimum requirement for interior use and light duty exterior use. This study delves into the potential of some of our syenogranite samples (I, IIA, IIS, and 10) as gamma radiation shielding materials. We have assessed the mass attenuation coefficient (GMAC), effective atomic number (Zeff), exposure build-up factor (EBF), and energy absorption build-up factor (EABF) for each of these samples. The GMAC and Zeff calculations were performed using the Phy-X online software, across a photon energy range of 0.015–15 MeV. Our findings suggest an inverse relationship between photon energy and GMAC, with the highest values observed for the (I) granite sample (∼18). This study shows the promising radiation shielding capacity of our samples. The insights derived from GMAC, Zeff, EBF, and EABF can serve as a guide for the development of effective, naturally sourced radiation shielding materials. Copyright © 2023 Rashwan, Lasheen, Abdelwahab, Azer, Zakaly, Alarifi, Ene and Thabet.King Saud University, KSUThis research was supported by the Researchers Supporting Project number (RSP2023R496), King Saud University, Riyadh, Saudi Arabia

    An Extended Investigation of High-Level Natural Radioactivity and Geochemistry of Neoproterozoic Dokhan Volcanics: A Case Study of Wadi Gebeiy, Southwestern Sinai, Egypt

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    High-level natural radioactivity, geochemical, geological, and radiological hazard assessment of the poorly investigated Wadi Gebeiy Dokhan volcanics rocks are discussed. Wadi Gebeiy Dokhan volcanics are located in Southwestern Sinai, Egypt, covering an area of ~1.3 km2. Dokhan volcanics rocks are represented by porphyritic dacite. Geochemically, they have medium-k characters and originate from calc-alkaline magma within a volcanics arc environment. Along the fault plane striking NNE-SSW, and at its intersection with the NW-SE fault plane, altered Dokhan volcanics occur with high radioactive anomalies. Radiological parameters (absorbed dose rate, radium equivalent, activity annual effective dose, external and internal hazard indices) are used to evaluate their suitability as an ornamental stone. Except for the absorbed dose rate, all the radiological hazard indices show that unaltered Dokhan volcanics can be used as an ornamental stone. Controversially, the applied radiological indices reveal that altered Dokhan volcanics have a higher content than the recommended values of UNSCEAR, reflecting their risk on human organs. © 2022 by the authors.H.M.H.Z. is funded by a scholarship under the Joint Executive Program between Egypt and Russia

    Distribution of Radionuclides and Radiological Health Assessment in Seih-Sidri Area, Southwestern Sinai

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    The current contribution goal is to measure the distribution of the radionuclide within the exposed rock units of southwestern Sinai, Seih-Sidri area, and assess the radiological risk. Gneisses, older granites, younger gabbro, younger granites, and post granitic dikes (pegmatites) are the main rock units copout in the target area. Radioactivity, as well as radiological implications, were investigated for forty-three samples from gneisses (seven hornblende biotite gneiss and seven biotite gneiss), older granites (fourteen samples), and younger granites (fifteen samples of syenogranites) using NaI (Tl) scintillation detector. External and internal hazard index (Hex, Hin), internal and external level indices (Iα, Iγ), absorbed dose rates in the air (D), the annual effective dose equivalent (AED), radium equivalent activity (Raeq), annual gonadal dose (AGDE), excess lifetime cancer risk (ELCR), and the value of Upper Continental Core 232Th/238U mass fractions were determined from the obtained values of 238U, 232Th and 40K for the examined rocks of Seih-Sidri area. The average 238U mg/kg in hornblende biotite gneiss and biotite gneiss, older granites, and syenogranites is 2.3, 2.1, 2.7, and 8.4 mg/kg, respectively, reflecting a relatively higher concentration of uranium content in syenogranites. The results suggest that using these materials may pose risks to one’s radiological health. © 2022 by the authors.PNURSP2022R173; Universitatea 'Dunărea de Jos' Galați, UDJGConceptualization, M.S.K.; data curation, M.S.K., E.S.R.L., A.E., H.A.A. and H.M.H.Z.; formal analysis, M.S.K., E.S.R.L., A.E., H.A.A. and H.M.H.Z.; funding acquisition, A.E., G.A.A. and H.M.H.Z.; investigation, M.S.K., E.S.R.L., A.E., H.A.A. and H.M.H.Z.; methodology, M.S.K., E.S.R.L., A.E., M.A.M.U., H.A.A., S.A.M.I. and H.M.H.Z.; project administration, A.E. and H.M.H.Z.; resources, M.S.K., E.S.R.L. and H.M.H.Z.; software, A.E. and H.M.H.Z.; supervision, A.E. and H.M.H.Z.; validation, G.A.A., M.S.K., E.S.R.L., M.A.M.U., H.A.A., S.A.M.I. and H.M.H.Z.; visualization, H.M.H.Z.; writing—original draft, M.S.K., E.S.R.L., A.E., H.A.A. and H.M.H.Z.; writing—review and editing, G.A.A., M.S.K., E.S.R.L., A.E., M.A.M.U., S.A.M.I., H.A.A. and H.M.H.Z. The researcher H.A.A. is funded by a scholarship under the Joint (Executive Program between Egypt and Russia). All authors have read and agreed to the published version of the manuscript

    Petrogenesis and Tectonic Implications of the Cryogenian I-Type Granodiorites from Gabgaba Terrane (NE Sudan)

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    The widely distributed granitic intrusions in the Nubian Shield can provide comprehensive data for understanding its crustal evolution. We present new bulk-rock geochemistry and isotopic (zircon U-Pb and Lu-Hf) data from the Haweit granodiorites in the Gabgaba Terrane (NE Sudan). The dated zircons presented a 206Pb/238U Concordia age of 718.5 ± 2.2 Ma, indicating that they crystallized during the Cryogenian. The granodiorites contain both biotite and amphibole as the main mafic constituents. The samples exhibit metaluminous (A/CNK = 0.84–0.94) and calc-alkaline signatures. Their mineralogical composition and remarkable low P2O5, Zr, Ce, and Nb concentrations confirm that they belong to I-type granites. They exhibit subduction-related magma geochemical characters such as enrichment in LILEs and LREEs and depletion in HFSEs and HREEs, with a low (La/Yb)N ratio (3.0–5.9) and apparent negative Nb anomaly. The positive Hf(t) values (+7.34 to +11.21) and young crustal model age (TDMC = 734–985 Ma) indicates a juvenile composition of the granodiorites. The data suggest that the Haweit granodiorites may have formed from partially melting a juvenile low-K mafic source. During subduction, the ascending asthenosphere melts might heat and partially melt the pre-existing lower crust mafic materials to generate the Haweit granodiorites in the middle segment of the Nubian Shield. © 2023 by the authors.King Saud University, KSUThis research was supported by Researchers Supporting Project number (RSP2023R496), King Saud University, Riyadh, Saudi Arabia. The author AE would like to thank “Dunarea de Jos” University of Galati, Romania, INPOLDE infrastructure, for the material and technical support.This research was supported by Researchers Supporting Project number (RSP2023R496), King Saud University, Riyadh, Saudi Arabia. The author A.E. would like to thank “Dunarea de Jos” University of Galati, Romania, INPOLDE infrastructure, for the material and technical support. The authors would like to thank the editors and the reviewers for their precious time, detailed and constructive reviews, and additional comments which significantly improved the manuscript

    Building the impedance model of a real machine

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    A reliable impedance model of a particle accelerator can be built by combining the beam coupling impedances of all the components. This is a necessary step to be able to evaluate the machine performance limitations, identify the main contributors in case an impedance reduction is required, and study the interaction with other mechanisms such as optics nonlinearities, transverse damper, noise, space charge, electron cloud, beam-beam (in a collider). The main phases to create a realistic impedance model, and verify it experimentally, will be reviewed, highlighting the main challenges. Some examples will be presented revealing the levels of precision of machine impedance models that have been achieved
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