Characterization of Electrical Breakdown for Low and High Pressure Hydrogen Gas in Coaxial Virtual Cathode Device
A.M.
Shagar
Plasma and Nuclear Fusion Department, Nuclear Research Center, Atomic Energy Authority, Cairo, Egypt
author
F. A.
Ebrahim
Plasma and Nuclear Fusion Department, Nuclear Research Center, Atomic Energy Authority, Cairo, Egypt
author
M. A.
Abd Al-Halim
Physics Department, Faculty of Science, Banha University, Egypt
author
M. E.
Abdel-kader
Plasma and Nuclear Fusion Department, Nuclear Research Center, Atomic Energy Authority, Cairo, Egypt
author
text
article
2018
eng
THE DC gas discharge is established between a coaxial cylindrical stainless steel electrodes. The coaxial cylindrical DC discharge device consists of an outer grid cathode and inner rods anode with 4 mm gap between them. This experimental study is focused on the effect of gas pressure and electric field strength on breakdown voltage. There is a balance between the electron attachment and first ionization collision, so the Second Townsend emission is the responsible for maintain the discharge.The I-V characteristic curvesfor different pressures ofhydrogen gas indicate that the highest current appears for the highest gas pressure. The gas breakdown voltage varies as a product of Pd and Townsend’s coefficients depends on gas pressure and E/P, where E is the electric field and P is the gas pressure.
Arab Journal of Nuclear Sciences and Applications
Egyptian Society of Nuclear Sciences and Applications (ESNSA)
1110-0451
51
v.
2
no.
2018
1
9
https://ajnsa.journals.ekb.eg/article_6505_2663abb1d68f192273d9459f318cf068.pdf
dx.doi.org/10.21608/ajnsa.2018.6505
Leaching and Precipitation of Thorium Ions from Cataclastic Rocks, Abu Rusheid Area, South Eastern Desert, Egypt
S. Y.
Afifi
Nuclear Materials Authority, P.O. Box 530 El Maadi, Cairo, Egypt
author
M. Z.
Saad
Chemistry Department, Faculty of Science, Zagazig University, Egypt
author
L. A.
Yousef
Nuclear Materials Authority, P.O. Box 530 El Maadi, Cairo, Egypt
author
A. H.
Ismail
Nuclear Materials Authority, P.O. Box 530 El Maadi, Cairo, Egypt
author
text
article
2018
eng
THE LEACHING of thorium from representative samples collected from Abu Rusheid area, south Eastern Desert, Egypt using sulphuric acid has been studied. Factors affecting the leaching of thorium were investigated such as, acid type, S/L ratio, H2SO4 concentration, leaching time, temperature and grain size. The best conditions for leaching of thorium were, H2SO4 acid as the best acid, S/L ratio of 1:5, 3.0 M H2SO4, 2.0 hour of leaching time, -200 mesh size at 90°C. After leaching, the mixture was filtrated then divided into two parts the leach liquor and the residue. The leach liquor was adjusted at pH 1.0 by ammonia solution and addition 10 % oxalic acid. The precipitate obtained was filtrated and dried at 120oC for 1 hour. The obtained precipitate showed 91.60 % of thorium content when using 3.0 M H2SO4 acid. The quality of the precipitate was confirmed by XRF
Arab Journal of Nuclear Sciences and Applications
Egyptian Society of Nuclear Sciences and Applications (ESNSA)
1110-0451
51
v.
2
no.
2018
10
19
https://ajnsa.journals.ekb.eg/article_6506_97e5c26af7e24877c17a362b204400b3.pdf
dx.doi.org/10.21608/ajnsa.2018.6506
The Influence of Fire Retardant (Aluminum Hydroxide) Concentrations on EPDM Rubber Under Ɣ Irradiation
Samaa. 1
Wasfy
Nuclear & Radiological Regulatory Authority, Cairo, Egypt
author
Elham
Hegazi
Nuclear & Radiological Regulatory Authority, Cairo, Egypt
author
A.
Abd El-megeed
National Institute for Standards, Cairo, Egypt
author
T.
Mahmoud
Shobra Faculty of Engineering, Benha University
author
E.Y.
El-Kady
Shobra Faculty of Engineering, Benha University
author
text
article
2018
eng
EPDM is the most commonly used type of rubbers for cables insulation. In order to improve the EPDM insulation rubber performance, many additives can be used. Aluminum hydroxide is used as a fire retardant because it is safe and cheap and reduces the amount of smoke produced in fires. In this study, two concentrations (10 and 20 phr) of aluminum hydroxide ATH were used to improve EPDM insulation properties and to prolong its operational life. The effect of gamma doses (up to 600 KGy) on the mechanical, physical and thermal properties of EPDM/ ATH has been investigated. The results of the present study show that the optimum concentration of ATH is 20phr.
Arab Journal of Nuclear Sciences and Applications
Egyptian Society of Nuclear Sciences and Applications (ESNSA)
1110-0451
51
v.
2
no.
2018
20
28
https://ajnsa.journals.ekb.eg/article_6507_319fa29d7ac9c38287e00d8436452069.pdf
dx.doi.org/10.21608/ajnsa.2018.6507
Recovery of Yttrium and Dysprosium from the Rare Earth Concentrate, Southwestern Sinai, Egypt
Mohamed M.
Fawzy
Nuclear Materials Authority, Cairo, Egypt
author
Saleh
Elhady
Nuclear Materials Authority, Cairo, Egypt
author
text
article
2018
eng
SEPARATION of ytrrium and dysprosium from the prepared chloride liquor of HREEs concentrate (44.1% Y, 9.04% Dy, 5.15% Er, 4.56% Gd, 2.31% Yb, 1.33% Ho, and 1.23% Sm) has been studied. The concentrate was obtained by the sulfatizing roasting of xenotime bearing ferruginous sandstone (from southwestern Sinai) followed by precipitation as oxalates then dissolution in HCl. Treatment of the prepared REEs chloride with Na2CO3 was achieved under suitable conditions by the addition of H2O2 to the carbonate solution where Dy, Gd, Sm, and Yb are precipitated while Y & Er left behind in the filtrate. Extraction of 87.3% Dy from the produced precipitate was studied using Cyanex 272. The relevant conditions for extraction and stripping processes have been optimized. After acidification, Y in the filtrate and Dy in the stripping solution are precipitated as oxalates. Pure products of Y2O3 and Dy2O3 have been prepared and subjected to different analyses.
Arab Journal of Nuclear Sciences and Applications
Egyptian Society of Nuclear Sciences and Applications (ESNSA)
1110-0451
51
v.
2
no.
2018
29
41
https://ajnsa.journals.ekb.eg/article_6508_7cfd34cc2482a6a5a1175b40c21c8880.pdf
dx.doi.org/10.21608/ajnsa.2018.6508
Production of Lightest Neutral MSSM Higgs Boson in Association with Neutralinos at Electron Positron Colliders
Ibrahim
Mahmoud
Department of Physics, Faculty of Science, Suez Canal University, Ismailia, Egypt
author
T.
A. El-Azim
Department of Physics, Faculty of Science, Cairo University, Giza, Egypt
author
text
article
2018
eng
THIS investigation deals with the results of a calculation of the cross section for the production of the lightest Higgs boson in association with an electron and a neutralino at electronpositron colliders ( ),where , and donates Neutralinos particles, in the framework of the minimal supersymmetric standard model (MSSM). The basic features of the MSSM prediction for some distinctive parameter scenarios were studied. The associated production of light neutral Higgs bosons and a pair of neutralinos at electron-positron colliders at different production’s modes have been carefully examined. It was found that the dominant production can reach a few fb, in the allowed ranges of parameters.
Arab Journal of Nuclear Sciences and Applications
Egyptian Society of Nuclear Sciences and Applications (ESNSA)
1110-0451
51
v.
2
no.
2018
42
50
https://ajnsa.journals.ekb.eg/article_6509_c52f1a5525f16c36492f2c689e755e76.pdf
dx.doi.org/10.21608/ajnsa.2018.6509
A Comparative Study of Volumetric Brain Tumor Measurements Using Different Manual Methods
Mohammed
Elywa
Biophysics Branch, Physics Department, Faculty of Science, Zagazig University, 44519 Zagazig, Egypt
author
text
article
2018
eng
EARLY detection of a minor tumor size change is difficult using traditional visual and clinical examination measurements. Although they are time-consuming, the general manual methods are the standard approach for quantitative measurement of human tumor and used in several hospitals. Magnetic Resonance Imaging (MRI) techniques are used to measure the human tumor volume manually or automatically. Three mathematical manual methods are used to calculate different tumor sizes. The study group consists of twenty-two patients with different tumor types (meningioma, glioblastoma, abscess, metastases, and glioma). All patients were scanned and all the MRI data acquired at 1.5 Tesla with diagnosis histological confirmation.The results of this study show that the triangle mathematical method (method -3) is more accurate than the other compared manual methods. The correlation shows a linear relationship between the mean values of method-1 and method-2 has R2 = 0.7975 and the P-value = 0.026 indicates the significance difference between method-1 and method-2. Moreover, the correlation between method-1 and method-3 has R2 = 0.9367 and the P-value = 0.003 that indicates high significancebetween them. The comparative study of the three manual methods demonstrated that triangle manual method (method-3) has significant approach to be used in medical diagnosis. Additionally, method-3 can indicate which part of the tumor tissue is totally damaged depending on the image parameters.Therefore, the triangle manual method can be considered as an accurate step in the diagnostic process.
Arab Journal of Nuclear Sciences and Applications
Egyptian Society of Nuclear Sciences and Applications (ESNSA)
1110-0451
51
v.
2
no.
2018
51
57
https://ajnsa.journals.ekb.eg/article_6510_59d225894f0b3205ab9cc0b293206a7c.pdf
dx.doi.org/10.21608/ajnsa.2018.6510
Evaluation of Potential Hazards Associated With Qattara Depression as a National Hydropower Project in Egypt
W.M.
Moustafa
Egyptian Nuclear and Radiological Regulatory Authority
author
R.A.
Hussien
Egyptian Nuclear and Radiological Regulatory Authority
author
N.
Nassar
Egyptian Nuclear and Radiological Regulatory Authority
author
text
article
2018
eng
THE OBJECTIVE of this paper is to evaluate, assess and study the potential hazard associated with the proposed national hydropower project at Qattara Depression. To achieve this objective, the two elements of sustainable development of this vast area, water and power, were developed. The Old Delta lies in the Western Desert of Egypt. It begins from the west of Assiut aligning the western outskirts of El Minya and Al Faiyum and terminated by Qattara Depression in the northern portion. It is a natural depression that covers about 2% of Egypt area. The depression depth is about 134 m below the sea level.A Clean electric generation could be achieved from the net head of filling Qattara Depression. Qattara Depression has the super potentiality of generating clean hydropower during the filling period and also has a high potentiality after filling period. This hydropower can provide Egypt with future needs and could be exported to Eastern Nile countries. The hydropower generation from Qattara Depression does not need filling time, high cost building dam. Previously eleven sites comprising 76 core samples of Lower (sandstone) and Middle (limestone) Miocene age were collected from the northeastern tip of the Qattara Depression in the north of the Western Desert of Egypt. The majority of samples showed weak to very weak remnant magnetization with goethite, hematite and titan magnetite as the main magnetic carriers. However, with a careful, detailed thermal demagnetization, they yielded stable, probably primary, magnetization. The resulting overall mean direction corresponded to a palaeomagnetic which seems to agree with other known African Miocene poles. This result implies that the Qattara area has been stable at least since Early Miocene. The presence of goethite as the main magnetic carrier supports the assumption that weathering has been playing an important role in the development and shaping of the depression. The possible site hazards associated with this project could be evaluated from different points of view, in order to give an overview to this promising project. The Qattara Depression, as a national project in Egypt, can achieve some accomplishments such as ; defending the Nile River Delta and the Mediterranean countries from the sinking or inundation of the Sea Level Rise (SLR) and reduce the cost of protecting coastal shores , generate hydroelectric power between 1000 to 2000 MW (depending on the filling water rate ) from Qattara Depression (under the sea level by depth of -60 (MSL) in average, desalinating water in large quantities; providing new areas, particularly for the refugee in case of the sinking or inundating of some parts of the Delta, due to the (SLR); Supporting housing, fish farming, tourism, and agriculture.
Arab Journal of Nuclear Sciences and Applications
Egyptian Society of Nuclear Sciences and Applications (ESNSA)
1110-0451
51
v.
2
no.
2018
58
67
https://ajnsa.journals.ekb.eg/article_6511_16270a106e1d632a6181fa6c9c8cb675.pdf
dx.doi.org/10.21608/ajnsa.2018.6511
Environmental Impact of Conventional Power Plant in Normal and Accidental Conditions
F.S.
Tawfik
Nuclear & Radiological Regulatory Authority (ENRRA), Cairo, Egypt
author
N.
Nassar
Nuclear & Radiological Regulatory Authority (ENRRA), Cairo, Egypt
author
M.A.H.
Abdel Aziz
Nuclear & Radiological Regulatory Authority (ENRRA), Cairo, Egypt
author
text
article
2018
eng
THE PREVENTION and simulation of chemical leakage has become one of the most important topics in the fields of environmental protection and process safety. Thermal Power plants are the major source of generation of electricity for any developing country. A power plant can affect the environment during its construction and its operation. These effects, or impacts, can be either temporary or permanent. A power plant and its auxiliary components (e.g. natural gas pipelines, water intakes and discharge, coal delivery and storage systems, new transmission lines and waste disposal sites) occupy space on the ground and in the air, use water resources, and, in most cases, emit pollutants into the air. Before construction of any electric facility it is required to study its impact on the environment. The environmental impact study shall cover the impact of the plant on the environmental in case of normal operation and accident condition through air. This paper covers the analysis of the meteorological parameters and calculate the concentration of pollutants emitting from two stacks of Electric Station-Power Plant, Damanhur, Egypt by simulating seasonal dispersion of pollutant. This plant uses mainly natural gas as fuel. The most likely pollutants emitted from the stack of the plant are nitrogen oxides, carbon monoxide, sulfur oxides, and particulate matter. For normal emission the AirPacts module was used in the Simplified Approach for Estimating Impacts of Electricity Generation (SIMPACTS) to calculates the physical impacts and the associated damage costs for the following types of pollutants namely,sulfur dioxide (SO2), nitrogen oxides (NOx), carbon monoxide (CO). For risk assessment, the Hybrid Single-Particle Lagrangian Integrated Trajectory (ALOHA) Model was used with different scenarios. Through this study, dispersion models are derived for nitrogen dioxide and methane concentrations for different scenarios, which result from the fuel combustion process , to determine the distance to a defined toxic endpoint and develop a prevention/emergency response program accordingly.
Arab Journal of Nuclear Sciences and Applications
Egyptian Society of Nuclear Sciences and Applications (ESNSA)
1110-0451
51
v.
2
no.
2018
68
81
https://ajnsa.journals.ekb.eg/article_6512_df5cde344f3a7edae7d2f5c94e6d22c6.pdf
dx.doi.org/10.21608/ajnsa.2018.6512
Performance of the Secondary Townsend Emission through the Electric Discharge Characteristics in Coaxial Vircator
A.M.
Shagar
Plasma Physics Department, Materials and Nuclear Industrialization Division, Nuclear Researsh Center, Atomic Energy Authority, Cairo, Egypt
author
S.T.
Abd El-Latif
Plasma Physics Department, Materials and Nuclear Industrialization Division, Nuclear Researsh Center, Atomic Energy Authority, Cairo, Egypt
author
F. A.
Ebrahim
Plasma Physics Department, Materials and Nuclear Industrialization Division, Nuclear Researsh Center, Atomic Energy Authority, Cairo, Egypt
author
text
article
2018
eng
THE INFLUENCE of secondary electron emission on self sustaining and maintaining discharge current is studied using a new type of DC glow discharge operated on virtual cathode theory through argon gas. The radial electron beam is generated outside the diode in coaxial Vircator. The transported electric discharge, from non-self sustaining to self sustaining discharge, occurs in the Townsend region and strongly depends on the secondary electron emission. The first ionization acts as a breakdown starter, then the second emission completes the electric discharge without consumed energy. The present work aims to study the effect of some physical parameters on the secondary electron emission to reduce the applied breakdown voltage and improve the ionization process, as well as to reduce the consumed electric energy. During the study, it was found that the self discharge started due to the second electron emission (γ) from the cathode which increased by increasing the ionization potential and decreasing the electric field. There was a balance between the first ionization coefficient and the electron attachment which confirms that the ( γ ) is the main element in the glow discharge. The minimum breakdown voltage for argon gas is 219 volts at Pd= 8 x 10-2 Torr.cm.
Arab Journal of Nuclear Sciences and Applications
Egyptian Society of Nuclear Sciences and Applications (ESNSA)
1110-0451
51
v.
2
no.
2018
82
88
https://ajnsa.journals.ekb.eg/article_6513_ba3b7e1bf11d4c6b09cf6993a1af714a.pdf
dx.doi.org/10.21608/ajnsa.2018.6513
Experimental Work for Minimizing Transmission Power Losses Using Nanotechnology
Amal
Abdel Gawad
Faculty of Engineering, Zagazig, Egypt
author
Mohamed
Taalab
Faculty of Engineering, Zagazig, Egypt
author
A.
ElSebaei
Faculty of Engineering, Zagazig, Egypt
author
N.
Ali
Faculty of Engineering, Zagazig, Egypt
author
text
article
2018
eng
T HE PRESENT study illustrates a new application of nanotechnology in electrical power transmission involving the coating the transmission lines of type ACSR with a nano layer of copper to minimize the resistance of the transmission and so minimize the transmitted power losses. The substrate used in the present investigation is made of aluminium of purity 99.9 %. The coating process is done by Hybrid Physical Vapor Decomposition using magnetron sputtering technique. The experimental testing has shown that the resistance of the coated substrates is reduced and the obtained results have proven the desired goal of power loss reduction in transmission lines.
Arab Journal of Nuclear Sciences and Applications
Egyptian Society of Nuclear Sciences and Applications (ESNSA)
1110-0451
51
v.
2
no.
2018
89
94
https://ajnsa.journals.ekb.eg/article_6514_e0a79e65637644697a26a21f2ce78d7f.pdf
dx.doi.org/10.21608/ajnsa.2018.6514
Parameters Affecting 137Cs Migration within Soil Profile
S.
SEFIEN
Radiation Protection Department, Nuclear Research Center, Atomic Energy Authority, Cairo Egypt
author
A.
IBRAHIM
Radiation Protection Department, Nuclear Research Center, Atomic Energy Authority, Cairo Egypt
author
W.
ABDELMALIK
Radiation Protection Department, Nuclear Research Center, Atomic Energy Authority, Cairo Egypt
author
text
article
2018
eng
SEVERAL studies have been carried out on the adsorption, distribution and migration of 137Cs within soil profile in the vicinity of the Nuclear Research Center, Atomic Energy Authority, Egypt, in addition to Ismailia Canal areas. The soil physicochemical and mineralogical characteristics were carried out and indicated that the soil samples consist mainly of sand (quartz) and silt fractions. The kinetics of caesium adsorption and its related adsorption isotherms for the tested soils were also studied. The sorption of 137Cs by soil minerals markedly affects its migration rate. The natural background of both locations under study indicated that the 137Cs concentration in the reactor site were found to be 30.82 Bq/kg while that at the canal site was found to be 0.87 Bq/kg. 137Cs in the reactor site may be originated from the fallout and from the external contamination which affected the background level. The vertical distribution and the migration rate of 137Cs have been studied for the soil profiles in both locations. These rates were found to be 0.056 and 0.031 cm/year for the reactor and canal site respectively.
Arab Journal of Nuclear Sciences and Applications
Egyptian Society of Nuclear Sciences and Applications (ESNSA)
1110-0451
51
v.
2
no.
2018
100
106
https://ajnsa.journals.ekb.eg/article_6516_9e312b863eadc2e0cbc5aa99be17f6d8.pdf
dx.doi.org/10.21608/ajnsa.2018.6516
Improvement of Nitrogen Fertilization Practices for Efficient Use by Wheat Irrigated With Saline Water under Mulching Using 15N Technique
M.
Kassab
Soil and Water Research Department, Nuclear Research Center, Atomic Energy Authority, Cairo, Egypt
author
Y.
Galal
Soil and Water Research Department, Nuclear Research Center, Atomic Energy Authority, Cairo, Egypt
author
A.
El-Gindy
Agricultural Engineering Department, Faculty of Agriculture, Ain Shams University, Cairo, Egypt
author
K.
El-Bagoury
Agricultural Engineering Department, Faculty of Agriculture, Ain Shams University, Cairo, Egypt
author
Sh.
El-Tohory
Soil and Water Research Department, Nuclear Research Center, Atomic Energy Authority, Cairo, Egypt
author
text
article
2018
eng
A FIELD experiment was carried out to investigate the effects of saline irrigation water and soil mulching on the growth and yield of cultivated wheat crop. Wheat yield for nonmulched treatment irrigated by fresh water (3366 kg.ha-1) was higher than the mulched one irrigated with fresh water (3227 kg.ha-1) and also higher than both mulched and non-mulched treatments irrigated by saline water of 6 and 8 dS.m-1. Under non-mulched condition, the treatment of the irrigated by 6 dS.m-1 recorded a higher production of2411 kg.ha-1 than those irrigated by 8 dS.m-1 (2231 kg.ha-1). In thesame sequence mulched treatment of the irrigated by 6 dS.m-1 recorded a higher yield (2936 kg ha-1) than the mulched one irrigated by 8 dS.m-1(2573 kg.ha-1).The nitrogen uptake by grain of wheat irrigated by fresh water and non-mulching treatments was much better thanthat in mulching treatments, but, mulching treatment combined with saline water (6, and 8 dS.m-1) was much better than non-mulched one. Similar trend was noticed with N uptake by straw.Proportion and absolute values ofNitrogen derived from fertilizer(Ndff) as well as nitrogen use efficiency (NUE)gained by grains or straw were severely reduced by increasing water salinity level as compared to those irrigated with fresh water. Mulching has a positive effect on combating salinity stress. It seems that, in general, mulching made the plants more able to derive more nitrogen from fertilizer and improved NUE. Nitrogen derived from fertilizer by grains was significantly higher than those of straw. Similar trend was noticed for NUE.
Arab Journal of Nuclear Sciences and Applications
Egyptian Society of Nuclear Sciences and Applications (ESNSA)
1110-0451
51
v.
2
no.
2018
95
99
https://ajnsa.journals.ekb.eg/article_6515_79e0079c5b1e2205b60ff24d955dbb0e.pdf
dx.doi.org/10.21608/ajnsa.2018.6515
Radioiodination and Biological Evaluation of Tizanidine as a Potential Brain Imaging Agent
Mai
Mourad
Centre of Radiation Oncology and Nuclear Medicine, Kasr Al-Ainy, Cairo, Egypt
author
Abeer
Amin
Labeled Compounds Department, Hot Labs Center, Egyptian Atomic Energy Authority, Cairo, Egypt
author
Hanan
Elsabagh
Labeled Compounds Department, Hot Labs Center, Egyptian Atomic Energy Authority, Cairo, Egypt
author
Gehad
Mohamed
Chemistry Department, Faculty of Science, Cairo University, Giza, Egypt
author
Salah
Abo-El-Enein
Chemistry Department, Faculty of Science, Ain Shams University, Cairo, Egypt
author
text
article
2018
eng
LABELING was carried out by direct iodination of tizanidine (100 µg) with radioiodine (125I) in a fast single step at room temperature, to produce 125I-tizanidine (125I-TZN). 50 µg chloramine-T (CAT) was used as an oxidizing agent to oxidize the iodide ion to the iodonium ion, at neutral pH = 7 within 15 min. A high radiochemical yield of 92.8 % ± 0.1 was obtained. 125I-TZN was stable for 2 h without detection of any by-products in the reaction mixture. The partition coefficient value of 125I-TZN was 2.21 ± 0.02, showing that it is very lipophilic and can easily cross the blood brain barrier. Biodistribution studies and in vivo imaging showed that the initial brain uptake correlated fairly well with the brain-binding affinity of the compound. The brain uptake of 125I-TZN was as high as 5.2 % and 8.0 % in biodistribution studies and in vivo imaging at 120 min post injection, respectively. Thus, 125I-TZN is promising in radioreceptor assays for brain imaging.
Arab Journal of Nuclear Sciences and Applications
Egyptian Society of Nuclear Sciences and Applications (ESNSA)
1110-0451
51
v.
2
no.
2018
107
115
https://ajnsa.journals.ekb.eg/article_5573_02ebdf189a35f955afc0b3c928936411.pdf
dx.doi.org/10.21608/ajnsa.2018.2178.1017
Neutronic Analysis of Heavy Water Application in HPLWR Emergency Core Cooling System
SAMAN
TASHAKOR
Department of Renewable Energy, Shiraz Branch, Islamic Azad University, Shiraz, Iran
author
text
article
2018
eng
Since 2002 a generation IV nuclear energy system development project has been initiated to enhance the future role of nuclear energy systems. Challenging technology goals for generation IV nuclear reactor systems were defined in 4 areas: sustainability, economics, safety and reliability and proliferation resistance. Light water reactors at supercritical pressure, being currently under design, are the new generation of nuclear reactors. The high-performance light water reactor (HPLWR) is the European version of the supercritical-pressure water cooled reactor (SCWR). The aim of this study is to reliability analysis of heavy water emergency core cooling system (ECCS) (instead of light water ECCS) in HPLWRs during LOCA (loss of coolant accident) through neutronics calculations and applied feedback.. Reliability analysis (neutronic calculations) are performed using WIMS and CITATION codes. Changes in neutronic parameters, such as neutron cross-sections, effective multiplication factor and power peaking factor during LOCA, are discussed by injecting different concentrations of the heavy water coolant by ECCS.
Arab Journal of Nuclear Sciences and Applications
Egyptian Society of Nuclear Sciences and Applications (ESNSA)
1110-0451
51
v.
2
no.
2018
116
123
https://ajnsa.journals.ekb.eg/article_7917_55f384004f07d683b33a79b13fdb0ee5.pdf
dx.doi.org/10.21608/ajnsa.2017.1940.1006
Creep behavior of β Cu-Zn Alloys
Adel
Mohamed
Solid physics, Zagazig University
author
text
article
2018
eng
Creep Behavior Abstract: Transient creep tests are performed under constant stress conditions at temperatures ranging from 533 to 653˚ K for Cu-38wt%Zn, and Cu-38wt%Zn-2wt% Pb samples. The transient creep is described by _tr= βt^n, where _tr and t are the transient creep strain and time. However, the parameters n, β are calculated, and the activation energy of the transient creep shows for both alloy two regions at low and high temperatures. Also, the activation energy were determined to clarify the controlling mechanism. At low temperature rang (240-360˚C), the strain rate sensitivity parameter m has values (0.247-0.174) while its values at high temperatures ranging from (0.192 up to 0.263) at 653˚K. These values give an indication that dislocation glide is probably an operating mechanism is grain boundary diffusion. Also, the change of microstructure was studied, grain size, microhardness, and stress-strain behavior has been studied too. Keywords: Transient creep, Cu-Zn-Pb, lattice-diffusion, dislocations.
Arab Journal of Nuclear Sciences and Applications
Egyptian Society of Nuclear Sciences and Applications (ESNSA)
1110-0451
51
v.
2
no.
2018
124
136
https://ajnsa.journals.ekb.eg/article_7925_0e65af0a8771806744494e570fb0a7bb.pdf
dx.doi.org/10.21608/ajnsa.2017.1945.1007