163 research outputs found
Momentum slip-stacking simulations for CERN SPS ion beams with collective effects
The LHC Injectors Upgrade (LIU) Project at CERN aims at doubling the total intensity of the Pb-ion beam for the High-Luminosity LHC (HL-LHC) Project. This goal can be achieved by using momentum slip-stacking (MSS) in the SPS, the LHC injector. This RF gymnastics, originally proposed to increase bunch intensity, will be used on the intermediate energy plateau to interleave two batches, reducing the bunch spacing from 100 ns to 50 ns. The MSS feasibility can be tested only in 2021, after the beam controls upgrade of the SPS 200 MHz RF system, so beam dynamics simulations are used to design this complicated beam manipulation. Simulations of the MSS were performed using the CERN BLonD code with a full SPS impedance model. Attention has been paid to the choice of the RF and machine parameters (beam energy, time duration, RF frequency and voltage programs) to reduce losses and the final bunch length which is crucial for the injection into the LHC 400 MHz buckets. The initial beam parameters used in simulations were obtained from beam measurements in the first part of the SPS cycle taking into account bunch-by-bunch losses on flat bottom and development of bunch instabilities
Implementation of synchronised PS-SPS transfer with barrier buckets
For the future intensity increase of the fixed-target beams in the CERN
accelerator complex, a barrier-bucket scheme has been developed to reduce the
beam loss during the 5-turn extraction from the PS towards the SPS, the
so-called Multi-Turn Extraction. The low-level RF system must synchronise the
barrier phase with the PS extraction and SPS injection kickers to minimise the
number of particles lost during the rise times of their fields. As the RF
voltage of the wide-band cavity generating the barrier bucket would be too low
for a conventional synchronisation, a combination of a feedforward cogging
manipulation and the real-time control of the barrier phase has been developed
and tested. A deterministic frequency bump has been added to compensate for the
imperfect circumference ratio between PS and SPS. This contribution presents
the concept and implementation of the synchronised barrier-bucket transfer.
Measurements with high-intensity beam demonstrate the feasibility of the
proposed transfer scheme.Comment: Talk presented at LLRF Workshop 2022 (LLRF2022, arXiv:2208.13680
Solar Chimney Power Plants: A Mini Review
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
Reductive Leaching Kinetics of Low Grade Manganese Deposits in H2SO4 Solution Using Malonic Acid as Reducing Agent
A leaching process was developed to extract manganese and metal values from Alloga manganese concentrate. The preferential leaching process was achieved through reductive leaching in dilute sulfuric acid medium with malonic acid as the reducing agent. Leaching parameters were optimized as 1.0 M H2SO4, 10% malonic acid in solid/liquid ratio 1:10 for 90 min at 8
Natural radioactivity levels in soils, rocks and water at a mining concession of Perseus gold mine and surrounding towns in Central Region of Ghana
Assessment of serum interleukin 19 level in patients with warts
Background: Warts are viral cutaneous infections caused by human papilloma virus (HPV), presented by verrucous growth over the skin surface. The cell mediated immune response is considered to play a crucial role in HPV clearance. The viral load and number of lesions increase when there is an imbalance between the T-helper 1 and T-helper 2 immune responses. Interleukin (IL)-19 is a cytokine that belongs to interleukin 10 cytokines family and constitutes a sub-family with IL-20, IL-22 and IL-24. IL-19 is mainly produced by activated monocytes and to a lesser extent by B-cells, keratinocytes and fetal membranes. IL-19 was found to shift T-cell maturation away from the pro-inflammatory T-helper 1 cells toward the anti-inflammatory T-helper 2 cells. It induces IL-4 and IL-13 production in T cells and apoptosis in monocytes. Aim: This study aimed to measure serum level of IL-19 in patients with warts compared to healthy controls and to find out the correlation between this level and number, size and clinical types of warts. Methods: The study included 50 patients with warts and 50 control subjects. Serum concentration of IL-19 was measured by enzyme-linked immune sorbent assay. Results: Interleukin-19 serum level was significantly lower in patients with warts than in controls (P < 0.003). Moreover, there was a significant positive correlation between IL-19 serum level and the number of warts (P = 0.027). Conclusion: Serum level of IL-19 was significantly lower in patients with warts, and this low level might be crucial for an effective cell mediated immunological response to HPV
Radiological Hazards and Natural Radionuclide Distribution in Granitic Rocks of Homrit Waggat Area, Central Eastern Desert, Egypt
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 Hazard Evaluation of Some Egyptian Magmatic Rocks Used as Ornamental Stone: Petrography and Natural Radioactivity
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
An Extended Investigation of High-Level Natural Radioactivity and Geochemistry of Neoproterozoic Dokhan Volcanics: A Case Study of Wadi Gebeiy, Southwestern Sinai, Egypt
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
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
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