Search results for: ionizing radiation
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 1374

Search results for: ionizing radiation

1194 Antioxidant Juice Prevents UV- Induced Skin Damage in Rats

Authors: S. P. Gomes, D. C. Goncalves, E. Ribeiro, M. C. L. Seelaender

Abstract:

Skin is susceptible to photo damage induced by exposure to sunlight, or ultraviolet (UV) radiation, which induces breakdown of extracellular matrix, DNA degradation, skin cell lesion and apoptosis, and development of cancer. Phytonutrients demonstrate protective effects against UV damage. The purpose of this study was evaluating the effect of an antioxidant juice (AJ) contaning Brazilian natural products upon skin damage. The juice was produced by Metabolics®. Male Wistar rats were divided in 4 groups: Animals receiving the antioxidant juice (AJ): orange, carrot, honey, tomato extract, avocado, ginger and camu-camu (Brazilian fruit, a major source of vitamin C) ad libitum for 21 days; or water (C), subdivided in groups exposed or not to UV radiation for 2 non consecutive days, during five hours each day, after 15 days of juice supplementation. On the 22nd day, rats were killed by decapitation and epithelium samples from the dorsal skin removed, fixed in bouin and embedded in paraffin. The sections were stained with hematoxylin and eosin or mallory and picrosirius red. Isolated DNA was submitted to electrophoresis (1.8% agarose gel, 0.5% ethidium bromide). UV radiation significantly induced sunburn of superficial epithelial cells of C, AJ treatment reduced this effect. Collagen changes were observed in UV groups, yet AJ treatment prevented collagen degradation. UV radiation induced significant DNA degradation, in C, which was prevented by AJ treatment. The antioxidant juice consumed chronically protected against acute skin damage.

Keywords: nutraceuticals, antioxidants, photoprotection, uv radiation

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1193 Assessment of Gamma Radiation Exposure of Soils Associated with Granitic Rocks in Kapıdağ Peninsula, Turkey

Authors: Buket Canbaz Öztürk, N. Füsun Çam, Günseli Yaprak, Osman Candan

Abstract:

The external terrestrial radiation exposure is related to the types of rock from which the soils originate. Higher radiation levels are associated with igneous rocks, such as granite, and lower levels with sedimentary rocks. Therefore, this study aims to assess the gamma radiation exposure of soils associated with granitic rocks in Kapıdağ Peninsula, Turkey. In the ongoing study, a comprehensive survey carried out systematically as a part of the environmental monitoring program on radiologic impact of the granitoid areas in Western Anatolia. The activity measurements of the gamma emitters (238U, 232Th and 40K) in the surface soil samples and the granitic rocks carried out by means of NaI(Tl) gamma-ray spectrometry system. To evaluate the radiological hazard of the natural radioactivity, the absorbed dose rate (D), the annual effective dose rate (AED), the radium equivalent activity (Raeq) and the external (Hex) hazard index were calculated according to the UNSCEAR 2000 report. The corresponding absorbed dose rates in air from all natural radionuclides were always much lower than 200 nGy h-1 and did not exceed the typical range of worldwide average values noticed in the UNSCEAR (2000) report. Furthermore, the correlation between soil and granitic rock samples were utilized, and external gamma radiation exposure distribution was mapped in Kapıdağ Peninsula.

Keywords: external absorbed dose, granitic rocks, Kapıdağ Peninsula, soil

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1192 Using Atomic Force Microscope to Investigate the Influence of UVA Radiation and HA on Cell Behaviour and Elasticity of Dermal Fibroblasts

Authors: Pei-Hsiu Chiang, Ling Hong Huang, Hsin-I Chang

Abstract:

In this research, we used UVA irradiation, which can penetrate into dermis and fibroblasts, the most abundant cells in dermis, to investigate the effect of UV light on dermis, such as inflammation, ECM degradation and elasticity loss. Moreover, this research is focused on the influence of hyaluronic acid (HA) on UVA treated dermal fibroblasts. We aim to establish whether HA can effectively relief ECM degradation, and restore the elasticity of UVA-damaged fibroblasts. Prolonged exposure to UVA radiation can damage fibroblasts and led variation in cell morphology and reduction in cell viability. Besides, UVA radiation can induce IL-1β expression on fibroblasts and then promote MMP-1 and MMP-3 expression, which can accelerate ECM degradation. On the other hand, prolonged exposure to UVA radiation reduced collagen and elastin synthesis on fibroblasts. Due to the acceleration of ECM degradation and the reduction of ECM synthesis, Atomic force microscope (AFM) was used to analyze the elasticity reduction on UVA-damaged fibroblasts. UVA irradiation causes photoaging on fibroblasts. UVA damaged fibroblasts with HA treatment can down-regulate the gene expression of MMP-1, MMP-3, and then slow down ECM degradation. On the other hand, HA may restore elastin and collagen synthesis in UV-damaged fibroblasts. Based on the slowdown of ECM degradation, UVA-damaged fibroblast elasticity can be effectively restored by HA treatment. In summary, HA can relief the photoaging conditions on fibroblasts, but may not be able to return fibroblasts to normal, healthy state. Although HA cannot fully recover UVA-damaged fibroblasts, HA is still potential for repairing photoaging skin.

Keywords: atomic force microscope, hyaluronic acid, UVA radiation, dermal fibroblasts

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1191 Current Approach in Biodosimetry: Electrochemical Detection of DNA Damage

Authors: Marcela Jelicova, Anna Lierova, Zuzana Sinkorova, Radovan Metelka

Abstract:

At present, electrochemical methods are used in various research fields, especially for analysis of biological molecules. The fact offers the possibility of using the detection of oxidative damage induced indirectly by γ rays in DNA in biodosimentry. The main goal of our study is to optimize the detection of 8-hydroxyguanine by differential pulse voltammetry. The level of this stable and specific indicator of DNA damage could be determined in DNA isolated from peripheral blood lymphocytes, plasma or urine of irradiated individuals. Screen-printed carbon electrodes modified with carboxy-functionalized multi-walled carbon nanotubes were utilized for highly sensitive electrochemical detection of 8-hydroxyguanine. Electrochemical oxidation of 8-hydroxoguanine monitored by differential pulse voltammetry was found pH-dependent and the most intensive signal was recorded at pH 7. After recalculating the current density, several times higher sensitivity was attained in comparison with already published results, which were obtained using screen-printed carbon electrodes with unmodified carbon ink. Subsequently, the modified electrochemical technique was used for the detection of 8-hydroxoguanine in calf thymus DNA samples irradiated by 60Co gamma source in the dose range from 0.5 to 20 Gy using by various types of sample pretreatment and measurement conditions. This method could serve for fast retrospective quantification of absorbed dose in cases of accidental exposure to ionizing radiation and may play an important role in biodosimetry.

Keywords: biodosimetry, electrochemical detection, voltametry, 8-hydroxyguanine

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1190 Lyapunov Exponents in the Restricted Three Body Problem under the Influence of Perturbations

Authors: Ram Kishor

Abstract:

The Lyapunov characteristic exponent (LCE) is an important tool to describe behavior of a dynamical system, which measures the average rate of divergence (or convergence) of a trajectory emanating in the vicinity of initial point. To analyze the behavior of nearby trajectory emanating in the neighborhood of an equilibrium point in the restricted three-body problem under the influence of perturbations in the form of radiation pressure and oblateness, we compute LCEs of first order with the help of slandered method which is based on variational equation of the system. It is observed that trajectories are chaotic in nature due positive LCEs. Also, we analyze the effect of radiation pressure and oblateness on the LCEs. Results are applicable to study the behavior of more generalized RTBP in the presence of perturbations such as PR drag, solar wind drag etc.

Keywords: Lyapunov characteristic exponent, RTBP, radiation pressure, oblateness

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1189 Renewable Energy System Eolic-Photovoltaic for the Touristic Center La Tranca-Chordeleg in Ecuador

Authors: Christian Castro Samaniego, Daniel Icaza Alvarez, Juan Portoviejo Brito

Abstract:

For this research work, hybrid wind-photovoltaic (SHEF) systems were considered as renewable energy sources that take advantage of wind energy and solar radiation to transform into electrical energy. In the present research work, the feasibility of a wind-photovoltaic hybrid generation system was analyzed for the La Tranca tourist viewpoint of the Chordeleg canton in Ecuador. The research process consisted of the collection of data on solar radiation, temperature, wind speed among others by means of a meteorological station. Simulations were carried out in MATLAB/Simulink based on a mathematical model. In the end, we compared the theoretical radiation-power curves and the measurements made at the site.

Keywords: hybrid system, wind turbine, modeling, simulation, validation, experimental data, panel, Ecuador

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1188 Effect Of Shading In Evaporatively Cooled Greenhouses In The Mediterranean Region

Authors: Nikolaos Katsoulas, Sofia Faliagka, Athanasios Sapounas

Abstract:

Greenhouse ventilation is an effective way to remove the extra heat from the greenhouse through air exchange between inside and outside when outside air temperature is lower. However, in the Mediterranean areas during summer, most of the day, the outside air temperature reaches values above 25 C; and natural ventilation can not remove the excess heat outside the greenhouse. Shade screens and whitewash are major existing measures used to reduce the greenhouse air temperature during summer by reducing the solar radiation entering the greenhouse. However, the greenhouse air temperature is reduced with a cost in radiation reduction. In addition, due to high air temperature values outside the greenhouse, generally, these systems are not sufficient for extracting the excess energy during sunny summer days and therefore, other cooling methods, such as forced ventilation combined with evaporative cooling, are needed. Evaporative cooling by means of pad and fan or fog systems is a common technique to reduce sensible heat load by increasing the latent heat fraction of dissipated energy. In most of the cases, the greenhouse growers, when all the above systems are available, apply both shading and evaporative cooling. If a movable screen is available, then the screen is usually activated when a certain radiation level is reached. It is not clear whether the shading screens should be used over the growth cycle or only during the most sensitive stages when the crops had a low leaf area and the canopy transpiration rate cannot significantly contribute to the greenhouse cooling. Furthermore, it is not clear which is the optimum radiation level that screen must be activated. This work aims to present the microclimate and cucumber crop physiological response and yield observed in two greenhouse compartments equipped with a pad and fan evaporative cooling system and a thermal/shading screen that is activated at different radiation levels: when the outside solar radiation reaches 700 or 900 W/m2. The greenhouse is located in Velestino, in Central Greece and the measurements are performed during the spring -summer period with the outside air temperature during summer reaching values up to 42C.

Keywords: microclimate, shading, screen, pad and fan, cooling

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1187 Participation in IAEA Proficiency Test to Analyse Cobalt, Strontium and Caesium in Seawater Using Direct Counting and Radiochemical Techniques

Authors: S. Visetpotjanakit, C. Khrautongkieo

Abstract:

Radiation monitoring in the environment and foodstuffs is one of the main responsibilities of Office of Atoms for Peace (OAP) as the nuclear regulatory body of Thailand. The main goal of the OAP is to assure the safety of the Thai people and environment from any radiological incidents. Various radioanalytical methods have been developed to monitor radiation and radionuclides in the environmental and foodstuff samples. To validate our analytical performance, several proficiency test exercises from the International Atomic Energy Agency (IAEA) have been performed. Here, the results of a proficiency test exercise referred to as the Proficiency Test for Tritium, Cobalt, Strontium and Caesium Isotopes in Seawater 2017 (IAEA-RML-2017-01) are presented. All radionuclides excepting ³H were analysed using various radioanalytical methods, i.e. direct gamma-ray counting for determining ⁶⁰Co, ¹³⁴Cs and ¹³⁷Cs and developed radiochemical techniques for analysing ¹³⁴Cs, ¹³⁷Cs using AMP pre-concentration technique and 90Sr using di-(2-ethylhexyl) phosphoric acid (HDEHP) liquid extraction technique. The analysis results were submitted to IAEA. All results passed IAEA criteria, i.e. accuracy, precision and trueness and obtained ‘Accepted’ statuses. These confirm the data quality from the OAP environmental radiation laboratory to monitor radiation in the environment.

Keywords: international atomic energy agency, proficiency test, radiation monitoring, seawater

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1186 Approaches to Estimating the Radiation and Socio-Economic Consequences of the Fukushima Daiichi Nuclear Power Plant Accident Using the Data Available in the Public Domain

Authors: Dmitry Aron

Abstract:

Major radiation accidents carry not only the potential risks of negative consequences for public health due to exposure but also because of large-scale emergency measures were taken by authorities to protect the population, which can lead to unreasonable social and economic damage. It is technically difficult, as a rule, to assess the possible costs and damages from decisions on evacuation or resettlement of residents in the shortest possible time, since it requires specially prepared information systems containing relevant information on demographic, economic parameters and incoming data on radiation conditions. Foreign observers also face the difficulties in assessing the consequences of an accident in a foreign territory, since they usually do not have official and detailed statistical data on the territory of foreign state beforehand. Also, they can suppose the application of unofficial data from open Internet sources is an unreliable and overly labor-consuming procedure. This paper describes an approach to prompt creation of relational database that contains detailed actual data on economics, demographics and radiation situation at the Fukushima Prefecture during the Fukushima Daiichi NPP accident, received by the author from open Internet sources. This database was developed and used to assess the number of evacuated population, radiation doses, expected financial losses and other parameters of the affected areas. The costs for the areas with temporarily evacuated and long-term resettled population were investigated, and the radiological and economic effectiveness of the measures taken to protect the population was estimated. Some of the results are presented in the article. The study showed that such a tool for analyzing the consequences of radiation accidents can be prepared in a short space of time for the entire territory of Japan, and it can serve for the modeling of social and economic consequences for hypothetical accidents for any nuclear power plant in its territory.

Keywords: Fukushima, radiation accident, emergency measures, database

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1185 Status of the European Atlas of Natural Radiation

Authors: G. Cinelli, T. Tollefsen, P. Bossew, V. Gruber, R. Braga, M. A. Hernández-Ceballos, M. De Cort

Abstract:

In 2006, the Joint Research Centre (JRC) of the European Commission started the project of the 'European Atlas of Natural Radiation'. The Atlas aims at preparing a collection of maps of Europe displaying the levels of natural radioactivity caused by different sources (indoor and outdoor radon, cosmic radiation, terrestrial radionuclides, terrestrial gamma radiation, etc). The overall goal of the project is to estimate, in geographical resolution, the annual dose that the public may receive from natural radioactivity, combining all the information from the different radiation components. The first map which has been developed is the European map of indoor radon (Rn) since in most cases Rn is the most important contribution to exposure. New versions of the map are realised when new countries join the project or when already participating countries send new data. We show the latest status of this map which currently includes 25 European countries. Second, the JRC has undertaken to map a variable which measures 'what earth delivers' in terms of Rn. The corresponding quantity is called geogenic radon potential (RP). Due to the heterogeneity of data sources across the Europe there is need to develop a harmonized quantity which at the one hand adequately measures or classifies the RP, and on the other hand is suited to accommodate the variety of input data used to estimate this target quantity. Candidates for input quantities which may serve as predictors of the RP, and for which data are available across Europe, to different extent, are Uranium (U) concentration in rocks and soils, soil gas radon and soil permeability, terrestrial gamma dose rate, geological information and indoor data from ground floor. The European Geogenic Radon Map gives the possibility to characterize areas, on European geographical scale, for radon hazard where indoor radon measurements are not available. Parallel to ongoing work on the European Indoor Radon, Geogenic Radon and Cosmic Radiation Maps, we made progress in the development of maps of terrestrial gamma radiation and U, Th and K concentrations in soil and bedrock. We show the first, preliminary map of the terrestrial gamma dose rate, estimated using the data of ambient dose equivalent rate available from the EURDEP system (about 5000 fixed monitoring stations across Europe). Also, the first maps of U, Th, and K concentrations in soil and bedrock are shown in the present work.

Keywords: Europe, natural radiation, mapping, indoor radon

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1184 Thermoluminescent Response of Nanocrystalline BaSO4:Eu to 85 MeV Carbon Beams

Authors: Shaila Bahl, S. P. Lochab, Pratik Kumar

Abstract:

Nanotechnology and nanomaterials have attracted researchers from different fields, especially from the field of luminescence. Recent studies on various luminescent nanomaterials have shown their relevance in dosimetry of ionizing radiations for the measurements of high doses using the Thermoluminescence (TL) technique, where the conventional microcrystalline phosphors saturate. Ion beams have been used for diagnostic and therapeutic purposes due to their favorable profile of dose deposition at the end of the range known as the Bragg peak. While dealing with human beings, doses from these beams need to be measured with great precision and accuracy. Henceforth detailed investigations of suitable thermoluminescent dosimeters (TLD) for dose verification in ion beam irradiation are required. This paper investigates the TL response of nanocrystalline BaSO4 doped with Eu to 85 MeV carbon beam. The synthesis was done using Co-precipitation technique by mixing Barium chloride and ammonium sulphate solutions. To investigate the crystallinity and particle size, analytical techniques such as X-ray diffraction (XRD) and Transmission electron microscopy (TEM) were used which revealed the average particle sizes to 45 nm with orthorhombic structure. Samples in pellet form were irradiated by 85 MeV carbon beam in the fluence range of 1X1010-5X1013. TL glow curves of the irradiated samples show two prominent glow peaks at around 460 K and 495 K. The TL response is linear up to 1X1013 fluence after which saturation was observed. The wider linear TL response of nanocrystalline BaSO4: Eu and low fading make it a superior candidate as a dosimeter to be used for detecting the doses of carbon beam.

Keywords: radiation, dosimetry, carbon ions, thermoluminescence

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1183 Effect of Thermal Radiation on Flow, Heat, and Mass Transfer of a Nanofluid over a Stretching Horizontal Cylinder Embedded in a Porous Medium with Suction/Injection

Authors: Elsayed M. A. Elbashbeshy, T. G. Emam, M. S. El-Azab, K. M. Abdelgaber

Abstract:

The effect of thermal radiation on flow, heat and mass transfer of an incompressible viscous nanofluid over a stretching horizontal cylinder embedded in a porous medium with suction/injection is discussed numerically. The governing boundary layer equations are reduced to a system of ordinary differential equations. Mathematica has been used to solve such system after obtaining the missed initial conditions. Comparison of obtained numerical results is made with previously published results in some special cases, and found to be in a good agreement.

Keywords: laminar flow, boundary layer, stretching horizontal cylinder, thermal radiation, suction/injection, nanofluid

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1182 The 5G Communication Technology Radiation Impact on Human Health and Airports Safety

Authors: Ashraf Aly

Abstract:

The aim of this study is to examine the impact of 5G communication technology radiation on human health and airport safety. The term 5G refers to the fifth generation of wireless mobile technology. The 5G wireless technology will increase the number of high-frequency-powered base stations and other devices and browsing and download speeds, as well as improve the network connectivity and play a big part in improving the performance of integrated applications, such as self-driving cars, medical devices, and robotics. 4G was the latest embedded version of mobile networking technology called 4G, and 5G is the new version of wireless technology. 5G networks have more features than 4G networks, such as lower latency, higher capacity, and increased bandwidth compared to 4G. 5G network improvements over 4G will have big impacts on how people live, business, and work all over the world. But neither 4G nor 5G have been tested for safety and show harmful effects from this wireless radiation. This paper presents biological factors on the effects of 5G radiation on human health. 5G services use C-band radio frequencies; these frequencies are close to those used by radio altimeters, which represent important equipment for airport and aircraft safety. The aviation industry, telecommunications companies, and their regulators have been discussing and weighing these interference concerns for years.

Keywords: wireless communication, radiofrequency, Electromagnetic field, environmental issues

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1181 Combustion Characteristic of Propane/Acetylene Fuel Blends Pool Fire

Authors: Yubo Bi, Xiao Chen, Shouxiang Lu

Abstract:

A kind of gas-fueled burner, named Burning Rate Emulator, was proposed for the purpose of the emulation of condensed fuel recently. The gaseous fuel can be pure combustible fuel gas or blends of gaseous fuel or inert gas. However, this concept was recently proposed without detailed study on the combustion characteristic of fuel blends. In this study, two kinds of common gaseous fuels were selected, propane and acetylene, to provide the combustion heat as well as a large amount of smoke, which widely exists in liquid and solid fuel burning process. A set of experiments were carried out using a gas-fueled burner with a diameter of 8 cm. The total volume flow rate of propane and acetylene was kept at 3 liters per minute. The volume fraction of propane varied from 0% to 100% at interval of 10%. It is found that the flame height increases with propane volume fraction, which may be caused by the increase of heat release rate, as the energy density of propane is larger than that of acetylene. The dimensionless flame height is correlated against dimensionless heat release rate, which shows a power function relationship. The radiation fraction of the flame does not show a monotonic relationship with propane volume fraction. With the increase of propane volume fraction from 0% to 100%, the value of radiation fraction increases first and reach a maximum value around 0.46 at a propane volume fraction of 10%, and then decreases continuously to a value of 0.25 at the propane volume fraction of 100%. The flame radiation is related to the soot in the flame. The trend of the radiation fraction reflects that there may be a synergistic effect of soot formation between propane and acetylene which can be guessed from the significantly high radiation fraction at a propane volume fraction of 10%. This work provides data for combustion of gaseous fuel blends pool fire and also give reference on the design of Burning Rate Emulator.

Keywords: Burning Rate Emulator, fuel blends pool fire, flame height, radiation fraction

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1180 Radioprotective Effects of Selenium and Vitamin-E against 6Mv X-Rays in Human Volunteers Blood Lymphocytes by Micronuclei Assay

Authors: Vahid Changizi, Aram Rostami, Akbar Mosavi

Abstract:

Purpose of study: Critical macromolecules of cells such as DNA are in exposure to damage of free radicals that induced from interaction of ionizing radiation with biological systems. Selenium and vitamin-E are natural compound that has been shown to be a direct free radical scavenger. The aim of this study was to investigate the in vivo/in vitro radioprotective effect of selenium and vitamin-E separately and synergistically against genotoxicity induced by 6MV x-rays irradiation in cultured blood lymphocytes from 15 human volunteers. Methods: Fifteen volunteers were divided in three groups include A, B and C. These groups were given slenium(800 IU), vitamin-E(100 mg) and selenium(400 IU) + vitamin-E(50 mg), respectively. Peripheral blood samples were collected from each group before(0 hr) and 1, 2 and 3 hr after selenium and vitamin-E administration (separately and synergistically). Then the blood samples were irradiated to 200 cGy of 6 Mv x-rays. After that, lymphocyte samples were cultured with mitogenic stimulation to determine the chromosomal aberrations wih micronucleus assay in cytokinesis-blocked binucleated cells. Results: The lymphocytes in the blood samples collected at 1 hr after ingestion selenium and vitamin-E, exposed in vitro to x-rays exhibited a significant decrease in the incidence of micronuclei, compared with control group at 0 hr. The maximum protection and decrease in frequency of micronuclei(50%) was observed at 1 hr after administration of selenium and vitamin-E synergistically. Conclusion: The data suggest that ingestion of selenium and vitamin-E as a radioprotector substances before exposures may reduce genetic damage caused by x-rays irradiation.

Keywords: x-rays, selenium, vitamin-e, lymphocyte, micronuclei

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1179 Study on the Mechanical Properties of Bamboo Fiber-Reinforced Polypropylene Based Composites: Effect of Gamma Radiation

Authors: Kamrun N. Keya, Nasrin A. Kona, Ruhul A. Khan

Abstract:

Bamboo fiber (BF) reinforced polypropylene (PP) based composites were fabricated by a conventional compression molding technique. In this investigation, bamboo composites were manufactured using different percentages of fiber, which were varying from 25-65% on the total weight of the composites. To fabricate the BF/PP composites untreated and treated fibers were selected. A systematic study was done to observe the physical, mechanical, and interfacial behavior of the composites. In this study, mechanical properties of the composites such as tensile, impact, and bending properties were observed precisely. Maximum tensile strength (TS) and bending strength (BS) were found for 50 wt% fiber composites, 65 MPa, and 85.5 MPa respectively, whereas the highest tensile modulus (TM) and bending modulus (BM) was examined, 5.73 GPa and 7.85 GPa respectively. The BF/PP based composites were treated with irradiated under gamma radiation (the source strength 50 kCi Cobalt-60) of various doses (i.e. 10, 20, 30, 40, 50 and 60 kGy doses). The effect of gamma radiation on the composites was also investigated, and it found that the effect of 30.0 kGy (i.e. units for radiation measurement is 'gray', kGy=kilogray) gamma dose showed better mechanical properties than other doses. After flexural testing, fracture sides of the untreated and treated both composites were studied by scanning electron microscope (SEM). SEM results of the treated BF/PP based composites showed better fiber-matrix adhesion and interfacial bonding than untreated BF/PP based composites. Water uptake and soil degradation tests of untreated and treated composites were also investigated.

Keywords: bamboo fiber, polypropylene, compression molding technique, gamma radiation, mechanical properties, scanning electron microscope

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1178 Modeling of Strong Motion Generation Areas of the 2011 Tohoku, Japan Earthquake Using Modified Semi-Empirical Technique Incorporating Frequency Dependent Radiation Pattern Model

Authors: Sandeep, A. Joshi, Kamal, Piu Dhibar, Parveen Kumar

Abstract:

In the present work strong ground motion has been simulated using a modified semi-empirical technique (MSET), with frequency dependent radiation pattern model. Joshi et al. (2014) have modified the semi-empirical technique to incorporate the modeling of strong motion generation areas (SMGAs). A frequency dependent radiation pattern model is applied to simulate high frequency ground motion more precisely. Identified SMGAs (Kurahashi and Irikura 2012) of the 2011 Tohoku earthquake (Mw 9.0) were modeled using this modified technique. Records are simulated for both frequency dependent and constant radiation pattern function. Simulated records for both cases are compared with observed records in terms of peak ground acceleration and pseudo acceleration response spectra at different stations. Comparison of simulated and observed records in terms of root mean square error suggests that the method is capable of simulating record which matches in a wide frequency range for this earthquake and bears realistic appearance in terms of shape and strong motion parameters. The results confirm the efficacy and suitability of rupture model defined by five SMGAs for the developed modified technique.

Keywords: strong ground motion, semi-empirical, strong motion generation area, frequency dependent radiation pattern, 2011 Tohoku Earthquake

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1177 Development of Typical Meteorological Year for Passive Cooling Applications Using World Weather Data

Authors: Nasser A. Al-Azri

Abstract:

The effectiveness of passive cooling techniques is assessed based on bioclimatic charts that require the typical meteorological year (TMY) for a specified location for their development. However, TMYs are not always available; mainly due to the scarcity of records of solar radiation which is an essential component used in developing common TMYs intended for general uses. Since solar radiation is not required in the development of the bioclimatic chart, this work suggests developing TMYs based solely on the relevant parameters. This approach improves the accuracy of the developed TMY since only the relevant parameters are considered and it also makes the development of the TMY more accessible since solar radiation data are not used. The presented paper will also discuss the development of the TMY from the raw data available at the NOAA-NCDC archive of world weather data and the construction of the bioclimatic charts for some randomly selected locations around the world.

Keywords: bioclimatic charts, passive cooling, TMY, weather data

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1176 Radiological Hazard Assessments and Control of Radionuclides Emitted from Building Materials in Kuwait Using Expert Systems

Authors: Abdulla Almulla, Wafaa Mahdi

Abstract:

Building materials can make a significant contribution to the level of natural radioactivity in closed dwelling areas. Therefore, developing an expert system for monitoring the activity concentrations (ACs) of naturally occurring radioactive materials (NORMs) existing in building materials is useful for limiting the population’s exposure to gamma radiation emitted from those materials. The present work not only is aimed at examining the indoor radon concentration emitted by the building materials that are originated from various countries but are commercially available in Kuwait, but also is aimed at developing an expert system for monitoring the radiation emitted from these materials and classifying it as normal (acceptable) or dangerous (unacceptable). This system makes it possible to always monitor any radiological risks to human health. When detecting high doses of radiation, the system gives warning messages.

Keywords: building materials, NORMs, HNBRA, radionuclides, activity concentrations, expert systems

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1175 A Design of Beam-Steerable Antenna Array for Use in Future Mobile Handsets

Authors: Naser Ojaroudi Parchin, Atta Ullah, Haleh Jahanbakhsh Basherlou, Raed A. Abd-Alhameed, Peter S. Excell

Abstract:

A design of beam-steerable antenna array for the future cellular communication (5G) is presented. The proposed design contains eight elements of compact end-fire antennas arranged on the top edge of smartphone printed circuit board (PCB). Configuration of the antenna element consists of the conductive patterns on the top and bottom copper foil layers and a substrate layer with a via-hole. The simulated results including input-impedance and also fundamental radiation properties have been presented and discussed. The impedance bandwidth (S11 ≤ -10 dB) of the antenna spans from 17.5 to 21 GHz (more than 3 GHz bandwidth) with a resonance at 19 GHz. The antenna exhibits end-fire (directional) radiation beams with wide-angle scanning property and could be used for the future 5G beam-forming. Furthermore, the characteristics of the array design in the vicinity of user-hand are studied.

Keywords: beam-steering, end-fire radiation mode, mobile-phone antenna, phased array

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1174 Simulations to Predict Solar Energy Potential by ERA5 Application at North Africa

Authors: U. Ali Rahoma, Nabil Esawy, Fawzia Ibrahim Moursy, A. H. Hassan, Samy A. Khalil, Ashraf S. Khamees

Abstract:

The design of any solar energy conversion system requires the knowledge of solar radiation data obtained over a long period. Satellite data has been widely used to estimate solar energy where no ground observation of solar radiation is available, yet there are limitations on the temporal coverage of satellite data. Reanalysis is a “retrospective analysis” of the atmosphere parameters generated by assimilating observation data from various sources, including ground observation, satellites, ships, and aircraft observation with the output of NWP (Numerical Weather Prediction) models, to develop an exhaustive record of weather and climate parameters. The evaluation of the performance of reanalysis datasets (ERA-5) for North Africa against high-quality surface measured data was performed using statistical analysis. The estimation of global solar radiation (GSR) distribution over six different selected locations in North Africa during ten years from the period time 2011 to 2020. The root means square error (RMSE), mean bias error (MBE) and mean absolute error (MAE) of reanalysis data of solar radiation range from 0.079 to 0.222, 0.0145 to 0.198, and 0.055 to 0.178, respectively. The seasonal statistical analysis was performed to study seasonal variation of performance of datasets, which reveals the significant variation of errors in different seasons—the performance of the dataset changes by changing the temporal resolution of the data used for comparison. The monthly mean values of data show better performance, but the accuracy of data is compromised. The solar radiation data of ERA-5 is used for preliminary solar resource assessment and power estimation. The correlation coefficient (R2) varies from 0.93 to 99% for the different selected sites in North Africa in the present research. The goal of this research is to give a good representation for global solar radiation to help in solar energy application in all fields, and this can be done by using gridded data from European Centre for Medium-Range Weather Forecasts ECMWF and producing a new model to give a good result.

Keywords: solar energy, solar radiation, ERA-5, potential energy

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1173 Thermal Radiation Effect on Mixed Convection Boundary Layer Flow over a Vertical Plate with Varying Density and Volumetric Expansion Coefficient

Authors: Sadia Siddiqa, Z. Khan, M. A. Hossain

Abstract:

In this article, the effect of thermal radiation on mixed convection boundary layer flow of a viscous fluid along a highly heated vertical flat plate is considered with varying density and volumetric expansion coefficient. The density of the fluid is assumed to vary exponentially with temperature, however; volumetric expansion coefficient depends linearly on temperature. Boundary layer equations are transformed into convenient form by introducing primitive variable formulations. Solutions of transformed system of equations are obtained numerically through implicit finite difference method along with Gaussian elimination technique. Results are discussed in view of various parameters, like thermal radiation parameter, volumetric expansion parameter and density variation parameter on the wall shear stress and heat transfer rate. It is concluded from the present investigation that increase in volumetric expansion parameter decreases wall shear stress and enhances heat transfer rate.

Keywords: thermal radiation, mixed convection, variable density, variable volumetric expansion coefficient

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1172 Design and Simulation of a Radiation Spectrometer Using Scintillation Detectors

Authors: Waleed K. Saib, Abdulsalam M. Alhawsawi, Essam Banoqitah

Abstract:

The idea of this research is to design a radiation spectrometer using LSO scintillation detector coupled to a C series of SiPM (silicon photomultiplier). The device can be used to detects gamma and X-ray radiation. This device is also designed to estimates the activity of the source contamination. The SiPM will detect light in the visible range above the threshold and read them as counts. Three gamma sources were used for these experiments Cs-137, Am-241 and Co-60 with various activities. These sources are applied for four experiments operating the SiPM as a spectrometer, energy resolution, pile-up set and efficiency. The SiPM is connected to a MCA to perform as a spectrometer. Cerium doped Lutetium Silicate (Lu₂SiO₅) with light yield 26000 photons/Mev coupled with the SiPM. As a result, all the main features of the Cs-137, Am-241 and Co-60 are identified in MCA. The experiment shows how photon energy and probability of interaction are inversely related. Total attenuation reduces as photon energy increases. An analytical calculation was made to obtain the FWHM resolution for each gamma source. The FWHM resolution for Am-241 (59 keV) is 28.75 %, for Cs-137 (662 keV) is 7.85 %, for Co-60 (1173 keV) is 4.46 % and for Co-60 (1332 keV) is 3.70%. Moreover, the experiment shows that the dead time and counts number decreased when the pile-up rejection was disabled and the FWHM decreased when the pile-up was enabled. The efficiencies were calculated at four different distances from the detector 2, 4, 8 and 16 cm. The detection efficiency was observed to declined exponentially with increasing distance from the detector face. Conclusively, the SiPM board operated with an LSO scintillator crystal as a spectrometer. The SiPM energy resolution for the three gamma sources used was a decent comparison to other PMTs.

Keywords: PMT, radiation, radiation detection, scintillation detectors, silicon photomultiplier, spectrometer

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1171 Fabrication and Mechanical Characterization of Sugarcane Bagasse Fiber-Reinforced Polypropylene Based Composites: Effect of Gamma Radiation

Authors: Kamrun N. Keya, Nasrin A. Kona, Ruhul A. Khan

Abstract:

Sugarcane bagasse (SCB)-reinforced Polypropylene (PP) Based matrix composites (25-45 wt% fiber) were fabricated by a compression molding technique. The SCB surface was chemically modified using 5%-10% sodium hydroxide (NaOH), and after that, mechanical properties, water uptake, and soil degradation of the composites were investigated. Tensile strength (TS), tensile modulus (TM), bending strength (BS), bending modulus (BM) and elongation at break (Eb%) of the 30wt% composites were found to be 35.6 MPa, 10.2 GPa, 56 MPa, 5.6 GPa, and 11%, respectively. The SCB/PP based composites were treated with irradiated under gamma radiation (the source strength 50 kCi Cobalt-60) of various doses (2.5 kGy to 10 kGy). The effect of gamma radiation on the composites was also investigated, and it found that the effect of 5.0 kGy (i.e. units for radiation measurement is 'gray', kGy=kilogray ) gamma dose showed better mechanical properties than other doses. The results revealed that the combination of the chemical modification of the SCB fibers and irradiation of the composites were more effective in compatibility improvement than chemical modification alone. After flexural testing, fracture sides of the untreated and treated both composites were studied by scanning electron microscope (SEM). SEM results of the treated SCB/PP based composites showed better fiber-matrix adhesion than untreated SCB/PP based composites. However, it was found that the treated SCB/PP composite has better mechanical strength, durability, and more receptivity than untreated SCB/PP based composite.

Keywords: sugarcane bagasse (SCB), polypropylene (PP), mechanical properties, scanning electron microscope (SEM), gamma radiation, water uptake tests and soil degradation

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1170 Design of a Portable Shielding System for a Newly Installed NaI(Tl) Detector

Authors: Mayesha Tahsin, A.S. Mollah

Abstract:

Recently, a 1.5x1.5 inch NaI(Tl) detector based gamma-ray spectroscopy system has been installed in the laboratory of the Nuclear Science and Engineering Department of the Military Institute of Science and Technology for radioactivity detection purposes. The newly installed NaI(Tl) detector has a circular lead shield of 22 mm width. An important consideration of any gamma-ray spectroscopy is the minimization of natural background radiation not originating from the radioactive sample that is being measured. Natural background gamma-ray radiation comes from naturally occurring or man-made radionuclides in the environment or from cosmic sources. Moreover, the main problem with this system is that it is not suitable for measurements of radioactivity with a large sample container like Petridish or Marinelli beaker geometry. When any laboratory installs a new detector or/and new shield, it “must” first carry out quality and performance tests for the detector and shield. This paper describes a new portable shielding system with lead that can reduce the background radiation. Intensity of gamma radiation after passing the shielding will be calculated using shielding equation I=Ioe-µx where Io is initial intensity of the gamma source, I is intensity after passing through the shield, µ is linear attenuation coefficient of the shielding material, and x is the thickness of the shielding material. The height and width of the shielding will be selected in order to accommodate the large sample container. The detector will be surrounded by a 4π-geometry low activity lead shield. An additional 1.5 mm thick shield of tin and 1 mm thick shield of copper covering the inner part of the lead shielding will be added in order to remove the presence of characteristic X-rays from the lead shield.

Keywords: shield, NaI (Tl) detector, gamma radiation, intensity, linear attenuation coefficient

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1169 Modeling of Global Solar Radiation on a Horizontal Surface Using Artificial Neural Network: A Case Study

Authors: Laidi Maamar, Hanini Salah

Abstract:

The present work investigates the potential of artificial neural network (ANN) model to predict the horizontal global solar radiation (HGSR). The ANN is developed and optimized using three years meteorological database from 2011 to 2013 available at the meteorological station of Blida (Blida 1 university, Algeria, Latitude 36.5°, Longitude 2.81° and 163 m above mean sea level). Optimal configuration of the ANN model has been determined by minimizing the Root Means Square Error (RMSE) and maximizing the correlation coefficient (R2) between observed and predicted data with the ANN model. To select the best ANN architecture, we have conducted several tests by using different combinations of parameters. A two-layer ANN model with six hidden neurons has been found as an optimal topology with (RMSE=4.036 W/m²) and (R²=0.999). A graphical user interface (GUI), was designed based on the best network structure and training algorithm, to enhance the users’ friendliness application of the model.

Keywords: artificial neural network, global solar radiation, solar energy, prediction, Algeria

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1168 Analysis of Combined Heat Transfer through the Core Materials of VIPs with Various Scattering Properties

Authors: Jaehyug Lee, Tae-Ho Song

Abstract:

Vacuum insulation panel (VIP) can achieve very low thermal conductivity by evacuating its inner space. Heat transfer in the core materials of highly-evacuated VIP occurs by conduction through the solid structure and radiation through the pore. The effect of various scattering modes in combined conduction-radiation in VIP is investigated through numerical analysis. The discrete ordinates interpolation method (DOIM) incorporated with the commercial code FLUENT® is employed. It is found that backward scattering is more effective in reducing the total heat transfer while isotropic scattering is almost identical with pure absorbing/emitting case of the same optical thickness. For a purely scattering medium, the results agree well with additive solution with diffusion approximation, while a modified term is added in the effect of optical thickness to backward scattering is employed. For other scattering phase functions, it is also confirmed that backwardly scattering phase function gives a lower effective thermal conductivity. Thus, the materials with backward scattering properties, with radiation shields are desirable to lower the thermal conductivity of VIPs.

Keywords: combined conduction and radiation, discrete ordinates interpolation method, scattering phase function, vacuum insulation panel

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1167 Investigating Nanocrystalline CaF2:Tm for Carbon Beam and Gamma Radiation Dosimetry

Authors: Kanika Sharma, Shaila Bahl, Birendra Singh, Pratik Kumar, S. P. Lochab, A. Pandey

Abstract:

In the present investigation, initially nano-particles of CaF2 were prepared by the chemical co-precipitation method and later the prepared salt was activated by thulium (0.1 mol%) using the combustion technique. The final product was characterized and confirmed by X-Ray diffraction (XRD) and transmission electron microscopy (TEM). Further, the thermoluminescence (TL) properties of the nanophosphor were studied by irradiating it with 1.25 MeV of gamma radiation and 65 MeV of carbon (C6+) ion beam. For gamma rays, two prominent TL peaks were observed with a low temperature peak at around 1070C and a high temperature peak at around 1570C. Furthermore, the nanophosphor maintained a linear TL response for the entire range of studied doses i.e. 10 Gy to 2000 Gy for both the temperature peaks. Moreover, when the nanophosphor was irradiated with 65 MeV of C6+ ion beam the shape and structure of the glow curves remained spectacularly similar and the nanophosphor displayed a linear TL response for the full range of studied fluences i.e. 5*1010 ions/cm2 to 1 *1012 ions/ cm2. Finally, various tests like reproducibility test and batch homogeneity were also carried out to define the final product. Thus, co-precipitation method followed by combustion technique was successful in effectively producing dosimetric grade CaF2:Tm for dosimetry of gamma as well as carbon (C6+) beam.

Keywords: gamma radiation, ion beam, nanocrystalline, radiation dosimetry

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1166 The MCNP Simulation of Prompt Gamma-Ray Neutron Activation Analysis at TRR-1/M1

Authors: S. Sangaroon, W. Ratanatongchai, S. Khaweerat, R. Picha, J. Channuie

Abstract:

The prompt gamma-ray neutron activation analysis system (PGNAA) has been constructed and installed at a 6 inch diameter neutron beam port of the Thai Research Reactor-1/ Modification 1 (TRR-1/M1) since 1989. It was designed for the reactor operating power at 1.2 MW. The purpose of the system is for an elemental and isotopic analytical. In 2016, the PGNAA facility will be developed to reduce the leakage and background of neutrons and gamma radiation at the sample and detector position. In this work, the designed condition of these facilities is carried out based on the Monte Carlo method using MCNP5 computer code. The conditions with different modification materials, thicknesses and structure of the PGNAA facility, including gamma collimator and radiation shields of the detector, are simulated, and then the optimal structure parameters with a significantly improved performance of the facility are obtained.

Keywords: MCNP simulation, PGNAA, Thai research reactor (TRR-1/M1), radiation shielding

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1165 Current Status of Ir-192 Brachytherapy in Bangladesh

Authors: M. Safiqul Islam, Md Arafat Hossain Sarkar

Abstract:

Brachytherapy is one of the most important cancer treatment management systems in radiotherapy department. Brachytherapy treatment is moved into High Dose Rate (HDR) after loader from Low Dose Rate (LDR) after loader due to radiation protection advantage. HDR Brachytherapy is a highly multipurpose system for enhancing cure and achieving palliation in many common cancers disease of developing countries. High-dose rate (HDR) Brachytherapy is a type of internal radiation therapy that delivers radiation from implants placed close to or inside, the tumor(s) in the body. This procedure is very effective at providing localized radiation to the tumor site while minimizing the patient’s whole body dose. Brachytherapy has proven to be a highly successful treatment for cancers of the prostate, cervix, endometrium, breast, skin, bronchus, esophagus, and head and neck, as well as soft tissue sarcomas and several other types of cancer. For the time being in our country we have 10 new HDR Remote after loading Brachytherapy. Right now 4 HDR Brachytherapy is already installed and running for patient’s treatment out of 10 HDR Brachytherapy. Ir-192 source is more comfortable than Co-60. In that case people or expert personnel prefer Ir-192 source for different kind of cancer patients. Ir-192 are economically, more flexible and familiar in our country.

Keywords: Ir-192, brachytherapy, cancer treatment, prostate, cervix, endometrium, breast, skin, bronchus, esophagus, soft tissue sarcomas

Procedia PDF Downloads 400