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Assessment of groundwater quantity, quality, and associated health risk of the Tano river basin, Ghana
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作者 Adwoba Kua-Manza Edjah Bruce Banoeng-Yakubo +6 位作者 Anthony Ewusi Enoch Sakyi-Yeboah David Saka Clara Turetta Giulio Cozzi David Atta-Peters Larry Pax Chegbeleh 《Acta Geochimica》 EI CAS CSCD 2024年第2期325-353,共29页
In the Tano River Basin,groundwater serves as a crucial resource;however,its quantity and quality with regard to trace elements and microbiological loadings remain poorly understood due to the lack of groundwater logs... In the Tano River Basin,groundwater serves as a crucial resource;however,its quantity and quality with regard to trace elements and microbiological loadings remain poorly understood due to the lack of groundwater logs and limited water research.This study presents a comprehensive analysis of the Tano River Basin,focusing on three key objectives.First,it investigated the aquifer hydraulic parameters and the results showed significant spatial variations in borehole depths,yields,transmissivity,hydraulic conductivity,and specific capacity.Deeper boreholes were concentrated in the northeastern and southeastern zones,while geological formations,particu-larly the Apollonian Formation,exhibit a strong influence on borehole yields.The study identified areas with high transmissivity and hydraulic conductivity in the southern and eastern regions,suggesting good groundwater avail-ability and suitability for sustainable water supply.Sec-ondly,the research investigated the groundwater quality and observed that the majority of borehole samples fall within WHO(Guidelines for Drinking-water Quality,Environmental Health Criteria,Geneva,2011,2017.http://www.who.int)limit.However,some samples have pH levels below the standards,although the groundwater generally qualifies as freshwater.The study further explores hydrochemical facies and health risk assessment,highlighting the dominance of Ca–HCO3 water type.Trace element analysis reveals minimal health risks from most elements,with chromium(Cr)as the primary contributor to chronic health risk.Overall,this study has provided a key insights into the Tano River Basin’s hydrogeology and associated health risks.The outcome of this research has contributed to the broader understanding of hydrogeologi-cal dynamics and the importance of managing groundwater resources sustainably in complex geological environments. 展开更多
关键词 GROUNDWATER Unsupervised machine learning technique HYDROCHEMISTRY Aquifer hydraulic parameter Health risk
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Delayed Neutrons Energy Spectrum Flux Profile of Nuclear Materials in Ghana’s Miniature Neutron Source Reactor Core
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作者 R.B.M. Sogbadji R.G. Abrefah +4 位作者 E. Ampomah-Amoako S.A. Birikorang S.E. Agbemava B.J.B. Nyarko H.C. Odoi 《World Journal of Nuclear Science and Technology》 2011年第2期26-30,共5页
A slightly prompt critical nuclear reactor would increase the neutron flux exponentially at a high rate causing the reactor to become uncontrollable, however due to the delayed neutrons, it is possible to leave the re... A slightly prompt critical nuclear reactor would increase the neutron flux exponentially at a high rate causing the reactor to become uncontrollable, however due to the delayed neutrons, it is possible to leave the reactor in a subcritical state as far as only prompt neutrons are concerned and to also sustain the chain reaction when it is going to die out. The delay neutron flux spectrum of the compact core of the Ghana’s miniature neutron source reactor (MNSR) was studied using the Monte Carlo method. 20,484 energy groups combined for all three categories of the energy distribution, thermal, slowing down and fast regions were modeled to create small energy bins. The moderator, the inner irradiation channels, the annulus beryllium reflector and the outer irradiation channels were the regions monitored. The delay thermal neutrons recorded its highest flux in the inner irradiation channel with an average flux of (4.0127 0.0076) × 1008 n/cm2?s, followed by the outer irradiation channel with an average flux of (2.4524 0.0049) × 1008 n/cm2?s. The beryllium reflector recorded the lowest flux in the thermal region. These values of the thermal energy range occurred in the energy range (0 – 0.625× 10 – 07) MeV. The inner irradiation channel again recorded the highest average flux of (1.2050 ± 0.0501) × 1007 n/cm2?s at the slowing down region in the energy range (0.821 – 6.94) MeV. The outer irradiation channel recorded the lowest flux in this region. In the fast energy region, (6.96 – 20) MeV, the core, where the moderator is found, the same trend was observed with the inner irradiation channel recording the highest flux at an average flux of (2.0647 ± 0.3260) × 1006 n/cm2?s .The outer irradiation channel recorded the second highest flux while the annulus beryllium reflector recorded very low flux in this region. The final k-effective contribution from only delay neutrons is 0.00834 with the delay neutron fraction being 0.01357 ± 0.00049, hence the Ghana MNSR has good safety inherent feature. 展开更多
关键词 RADIOACTIVITY Doses water GAMMA Spectroscopy Oil Areas NIGERIA
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Rainfall Variability over Ghana: Model versus Rain Gauge Observation 被引量:1
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作者 Francis Nkrumah Nana Ama Browne Klutse +4 位作者 David Cudjoe Adukpo Kwadwo Owusu Kwesi Akumenyi Quagraine Alfred Owusu William Gutowski 《International Journal of Geosciences》 2014年第7期673-683,共11页
This paper used the International Centre for Theoretical Physics (ICTP) Regional Climate Model, Version 3 (RegCM3) and rain gauge data selected from the Ghana Meteorological Agency (GMet) from 1990 to 2008 to investig... This paper used the International Centre for Theoretical Physics (ICTP) Regional Climate Model, Version 3 (RegCM3) and rain gauge data selected from the Ghana Meteorological Agency (GMet) from 1990 to 2008 to investigate the extent and nature of variability in the annual rainfall and pattern of the raining seasons in Ghana. In the study, six meteorological stations selected from three rainfall distribution zones according to the divisions of the GMet were used to study the pattern of rainfall and its departure from the normal trend. The study also assessed the performance of the RegCM3 simulation with reference to the observed gauge data. Results confirmed the unimodal nature of the rainfall annual cycle over the northern belt and bi-modal rainfall nature over the middle and southern belts of Ghana. Negative departures of rainfall implying consistent downward trend were observed at all the stations. Our analysis showed that RegCM3 captured the average rainfall over Ghana but demonstrated an underestimation as compared to the observed gauge data. The model also had difficulty stimulating the departures accurately in direction and in magnitude in all the stations except for Accra where RegCM3 simulated the right direction of the departures. 展开更多
关键词 RAINFALL VARIABILITY Ghana REGCM3 TEMPORAL RAINFALL Distribution RAIN GAUGE Data
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Ghana's experience in the establishment of a national data center
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作者 Amponsah Paulina Ekua Serfor-Armah Yaw 《Earthquake Science》 CSCD 2012年第4期347-351,共5页
The government of Ghana in a bilateral agreement with the Preparatory Commission for the Comprehensive Nuclear Test-Ban Treaty Organization (CTBTO) has established a National Data Center in Ghana with the aim of mon... The government of Ghana in a bilateral agreement with the Preparatory Commission for the Comprehensive Nuclear Test-Ban Treaty Organization (CTBTO) has established a National Data Center in Ghana with the aim of monitoring the testing of nuclear explosions. Seismic, hydroacoustic, radionuclide and infrasound methods are used for the monitoring. The data center was commissioned on 3 February, 2010 at the Ghana Atomic Energy Commission. At present Ghana does not have any operational, centralised data (seismic, hydroacoustic, radionuclide and infrasound) acquisition system with the capability of accessing data from other international stations. Hence, the need of setting up the National Data Center which would enable us constantly monitor, manage and coordinate both natural and man-made seismic activities in the country and around the globe, upload data to the International Data Center (IDC) as well as receive and use International Monitoring System (IMS) data and IDC products for treaty verification and compliance. Apart from these, the center also accesses and analyzes seismic waveforms relevant to its needs from the International Data Center; makes data available to its stakeholder institutions for earthquake disaster mitigation; reports on all aspects of disasters related to earthquake to the relevant government agencies that deal with disasters; makes recommendations to the government of Ghana on earthquake safety measures; provides information to assist government institutions to develop appropriate land and building policies. The center in collaboration with stakeholder agencies periodically organises public lectures on earthquake disaster risk mitigation. 展开更多
关键词 Ghana SEISMICITY TREATY nuclear explosion
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Enhancing the Hygienic Quality of Some Ghanaian Food Products by Gamma Irradiation
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作者 Abraham Adu-Gyamfi Victoria Appiah 《Food and Nutrition Sciences》 2012年第2期219-223,共5页
The microbiological quality (microbial load and profile) of 6 Ghanaian food products was determined before and after irradiation (0 kGy, 5 kGy, 7.5 kGy, 10 kGy) using standard microbiological methods. The microbial lo... The microbiological quality (microbial load and profile) of 6 Ghanaian food products was determined before and after irradiation (0 kGy, 5 kGy, 7.5 kGy, 10 kGy) using standard microbiological methods. The microbial load was estimated by the total viable count (TVC) and moulds and yeasts count (MYC). The range of TVC and MYC of the un-irradiated products were 103 cfu/g - 106 cfu/g and 0 cfu/g - 106 cfu/g respectively. Un-irradiated Banku Mix Powder, Fermented Maize Powder and Cassava Dough Powder had relatively low microbial load (TVC ? 6.1 × 103 cfu/g;MYC ? 4.9 × 102 cfu/g). Un-irradiated Fermented Maize Dough, Kokonte Powder and Cassava Dough had relatively high TVC of >106 cfu/g. Eleven and 3 microbial isolates were detected in the un-irradiated and irradiated products respectively and the most common were Aspergillus niger and Bacillus spp. Irradiation dose of 10 kGy eliminated all microorganisms from the products. Doses of 5 and 7.5 kGy reduced the microbial loads of the products by approximately 1 to 6 log cycles to meet national and international standards. The use of low dose gamma radiation by the local food industry could improve the hygienic quality, extend shelf-life and enhance the competitiveness of the Ghanaian food products in domestic and export markets. 展开更多
关键词 Hygienic QUALITY GAMMA IRRADIATION Ghanaian FOOD Products
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Changes in Rainfall Characteristics in Wenchi and Saltpond Farming Areas of Ghana
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作者 Kwesi Akumenyi Quagraine Nana Ama Browne Klutse +2 位作者 Francis Nkrumah David Cudjoe Adukpo Kwadwo Owusu 《International Journal of Geosciences》 2017年第3期305-317,共13页
Ghana’s economy heavily relies on agriculture, which is predominantly rainfed across its agro-ecological zones. As a result of this, it is vulnerable to rainfall variability, which tends to have a major impact on the... Ghana’s economy heavily relies on agriculture, which is predominantly rainfed across its agro-ecological zones. As a result of this, it is vulnerable to rainfall variability, which tends to have a major impact on the industrial and agricultural production sectors of the country. This study investigates the variations occurring across two major farming areas (Wenchi and Saltpond) within the Transition and Coastal Savannah agro-ecological zones of Ghana respectively. Rainfall variations are studied with rainfall data from 1968-2011 from Ghana Meteorological Agency (GMet). The rainfall analysis is done over two Climatological Periods (CP), 1968-1989 as CP1 and 1990-2011 as CP2. This study uses two climatic extreme indices as well as rainfall amounts and onset over these two agro-ecological zones to investigate the changes that have occurred in rainfall. The study found that in the Coastal agro-ecological zone, CP1 had a decreasing rainfall trend as compared to CP2 with higher variations in Saltpond. In the Transition agro-ecological zone, Wenchi, CP1 also exhibited a decreasing trend as compared to CP2. In addition, onset of rains in Saltpond mostly occurred in May for CP1 but for CP2, it oscillated between April and May. For Wenchi, onset of rains was in March for CP1 and predominantly April for CP2. In going forward, farmers in these agro-ecological zones should be supported to practice effective adaptation and mitigation measures so as to improve their yields in this challenging climate. 展开更多
关键词 Climate VARIABILITY RAINFALL Extreme ONSET Agro-Ecological ZONES Ghana
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Socio-Economic Impact of Fruit Flies Control in Mango Production in Ghana, Evidence from “Manya Krobo”
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作者 Kwamina Ewur Banson Alexander Egyir-Yawson 《Journal of Agricultural Science and Technology(B)》 2014年第6期454-463,共10页
关键词 化学控制 社会经济影响 加纳 生产 芒果 苍蝇 水果 证据
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Assessment of Patterns of Climate Variables and Malaria Cases in Two Ecological Zones of Ghana
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作者 Nana Ama Browne Klutse Fred Aboagye-Antwi +1 位作者 Kwadwo Owusu Yaa Ntiamoa-Baidu 《Open Journal of Ecology》 2014年第12期764-775,共12页
Climate change is projected to impact human health, particularly incidence of water related and vector borne diseases, such as malaria. A better understanding of the relationship between rainfall patterns and malaria ... Climate change is projected to impact human health, particularly incidence of water related and vector borne diseases, such as malaria. A better understanding of the relationship between rainfall patterns and malaria cases is thus required for effective climate change adaptation strategies involving planning and implementation of appropriate disease control interventions. We analyzed climatic data and reported cases of malaria spanning a period of eight years (2001 to 2008) from two ecological zones in Ghana (Ejura and Winneba in the transition and coastal savannah zones respectively) to determine the association between malaria cases, and temperature and rainfall patterns and the potential effects of climate change on malaria epidemiological trends. Monthly peaks of malaria caseloads lagged behind monthly rainfall peaks. Correlation between malaria caseloads and rainfall intensity, and minimum temperature were generally weak at both sites. Lag correlations of up to four months yielded better agreement between the variables, especially at Ejura where a two-month lag between malaria caseloads and rainfall was significantly high but negatively correlated (r = -0.72;p value < 0.05). Mean monthly maximum temperature and monthly malaria caseloads at Ejura showed a strong negative correlation at zero month lag (r = -0.70, p value < 0.05), with a similar, but weaker relationship at Winneba, (r = -0.51). On the other hand, a positive significant correlation (r = 0.68, p value < 0.05) between malaria caseloads and maximum temperature was observed for Ejura at a four-month lag, while Winneba showed a strong correlation (r = 0.70;p value < 0.05) between the parameters at a two-month lag. The results suggest maximum temperature as a better predictor of malaria trends than minimum temperature or precipitation, particularly in the transition zone. Climate change effects on malaria caseloads seem multi-factorial. For effective malaria control, interventions could be synchronized with the most important climatic predictors of the disease for greater impact. 展开更多
关键词 MALARIA RAINFALL Temperature CLIMATE Change ECOLOGICAL ZONE
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Simulation of the Rainfall Regime over Ghana from CORDEX
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作者 Kwadwo Owusu Nana Ama Browne Klutse 《International Journal of Geosciences》 2013年第4期785-791,共7页
This paper investigates how well the rainfall regime on which many livelihoods depend, in Ghanais well represented by the Coordinated Regional Climate Downscaling Experiment (CORDEX). The objective of the study is to ... This paper investigates how well the rainfall regime on which many livelihoods depend, in Ghanais well represented by the Coordinated Regional Climate Downscaling Experiment (CORDEX). The objective of the study is to demonstrate how well the ten CORDEX models are able to capture the spatial and temporal rainfall seasonality over the southern and northern sub-sections ofGhana. The choice of the sub-sections is based on the fact that south of 8°N experiences a bi-modal rainfall regime while the north has a uni-modal regime. The results indicate that the rainfall overGhanais associated with high levels of variability at the inter-annual time scale. Particularly over the southern part ofGhana, all the models follow the same trend as represented overGhanawith similar rainfall values as the observation. Over the northern part ofGhana, models record relatively low rainfall agreeing with the observation. However, most of the models overestimate the northern region rainfall as it is in the case of the southern Ghana. CORDEX as shown in this analysis could be useful in providing Ghana with at least 10 different model outputs for impact analysis. Caution is however given that, since individual models give different performance and the fact that models in general have their inherent deficiencies, an ensemble mean of the models could provide a better result. 展开更多
关键词 CORDEX RAINFALL MODELLING CLIMATE CHANGE CLIMATE VARIABILITY CLIMATE Prediction Ghana
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Induced Electromagnetic Fields Estimation in Spine Examinations of MRI Patients: A Re-Evaluation of Existing Clinical Protocols at a Hospital in Accra, Ghana
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作者 Frempong Acheampong Theresa Dery +1 位作者 Rita Appiah Daniel A. Abaye 《Journal of Applied Mathematics and Physics》 2018年第5期1065-1075,共11页
Patients undergoing Magnetic Resonance Imaging (MRI) are exposed to strong, non-uniform static magnetic fields outside of the central imaging region, in which the movement of the body may induce electric currents in t... Patients undergoing Magnetic Resonance Imaging (MRI) are exposed to strong, non-uniform static magnetic fields outside of the central imaging region, in which the movement of the body may induce electric currents in tissues which could possibly be harmful. The purpose of this study was to re-evaluate existing clinical protocols by determining the induced electromagnetic (EM) fields in MRI spine examinations. The study covered 120 MRI spine examinations at the MRI Unit of a hospital in Accra, Ghana. A numerical model based on Faraday’s equation was developed using the finite difference method (FDM) and MATLAB software to compute, first, a test simulation of induced EM field intensities and then actual measurements of induced fields on the spine. The simulation results were peak induced electric field, 0.39 V/m and current density, 0.039 A/m2. Patient results were;calculated maximum velocity, 0.29 m/s;peak induced electric field strength, 0.44 V/m, and current density, 0.043 A/m2. The levels of induced EM-fields were such that they would not pose any potential health hazards to the patients as these values were well below the recommended guidance levels set by the Directive IEC 60601-2-33 of the European Parliament. 展开更多
关键词 MRI SPINE EXAMINATIONS Finite DIFFERENCE Method Faraday’s Equation
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Scatter Radiation Dose Assessment in the Radiology Department of Cape Coast Teaching Hospital-Ghana
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作者 J. Owusu-Banahene E. O. Darko +3 位作者 D. F. Charles A. Maruf I. Hanan G. Amoako 《Open Journal of Radiology》 2018年第4期299-306,共8页
During the operation of an X-ray machine, if the radiation protection of X-ray room is insufficient, not only the patient but also clinical staffs as well as public are exposed to high X-ray exposures. In this researc... During the operation of an X-ray machine, if the radiation protection of X-ray room is insufficient, not only the patient but also clinical staffs as well as public are exposed to high X-ray exposures. In this research work, leakage and scattered radiations were measured from X-ray machine in the radiology department of Cape Coast Teaching hospital in the Cape Coast Municipality of Ghana. The scattered radiation exposures of X-rays in some selected areas within the facility were measured. The X-ray machine was operated for a range of kilo voltage peaks of kVp 77, 70, 63 and 66 with intensities 20, 6.3 and 8.0 mAs, which represents the main technique factors of some body parts such as chest, lumbar spine and extremities during radiographic examinations. The measurements were performed using a RADOS-120 Universal survey meter. The radiation doses rates measured in the various locations in the Radiology Department of Cape Coast Teaching Hospital of Ghana were in the range of 0.10 &mu;Sv/hr to 0.12 &mu;Sv/hr. These values were all within the background measurement of 0.10 &mu;Sv/hr. Moreover, there were no risks of high radiation doses to patients, staffs and people visiting the X-ray department. The results obtained indicated that within the radiology department of the Hospital, all the selected locations were very safe to patients, occupational workers and the general public which could be attributed to adequate shielding in the facility. 展开更多
关键词 X-Rays Exposure DOSE SCATTERED and LEAKAGE Radiation
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Determination of Neutron Fluxes and Spectrum Shaping Factors in Irradiation Sites of Ghana’S Miniature Neutron Source Reactor (mnsr) by Activation Method After Compensation of Loss of Excess Reactivty
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作者 R.B.M. Sogbadji B.J.B. Nyarko +1 位作者 E.H.K. Akaho R. G. Abrefah 《World Journal of Nuclear Science and Technology》 2011年第2期50-56,共7页
Accurate neutron flux values in irradiation channels of research reactors are very essential to their usage. The total neutron flux of the Ghana Research Reactor-1(GHARR-1) was measured after a beryllium reflector was... Accurate neutron flux values in irradiation channels of research reactors are very essential to their usage. The total neutron flux of the Ghana Research Reactor-1(GHARR-1) was measured after a beryllium reflector was added to its shim to compensate for excess reactivity loss. The thermal, epithermal and fast neutron fluxes were determined by the method of foil activation. The experimental samples with and without a cadmium cover of 1-mm thickness were irradiated in the isotropic neutron field of the irradiation sites of Ghana Research Reactor-1 facility. The induced activities in the sample were measured by gamma ray spectrometry with a high purity germanium detector. The necessary correction for gamma attenuation, thermal neutrons and resonance neutron self-shielding effects were taken into account during the experimental analysis. By defining cadmium cutoff energy of 0.55eV, Al-0.1% Au wires of negligible thickness were irradiated at 3kW to determine the neutron fluxes of two irradiation channels, outer channel 7 and inner channel 2 whose Neutron Shaping Factor (α) were found to be (0.037 ± 0.001) and (–0.961 ± 0.034). The neutron flux ratios at the inner irradiation site 2 were found to be, (25.308 ± 3.201) for thermal to epithermal neutrons flux, (0.179 ± 0.021) for epithermal to fast neutrons flux and (4.528 ± 0.524) for thermal to fast neutrons flux, in the outer irradiation site 7, the neutron flux ratios were found to be, (40.865 ± 3.622) for thermal to epithermal neutrons flux, (0.286 ± 0.025) for epithermal to fast neutrons flux and (11.680 ± 1.030) for thermal to fast neutrons flux. 展开更多
关键词 FLUENCE Rate FOIL Activation NEUTRON SELF-SHIELDING Flux Ratio
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Study of Criticality Safety and Neutronic Performance for a 348-Fuel-Pin Ghana Research Reactor-1 LEU Core Using MCNP Code
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作者 Henry Cecil Odoi Edward H. K. Akaho +2 位作者 Sunday A. Jonah Rex Gyeabour Abrefah Viva Y. Ibrahim 《World Journal of Nuclear Science and Technology》 2014年第1期46-52,共7页
The National Nuclear Research Institute of the Ghana Atomic Energy Commission is undertaking steps to convert the Ghana Research Reactor-1 from HEU Core to LEU. The proposed LEU core consists of 12.5% enriched UO2 fue... The National Nuclear Research Institute of the Ghana Atomic Energy Commission is undertaking steps to convert the Ghana Research Reactor-1 from HEU Core to LEU. The proposed LEU core consists of 12.5% enriched UO2 fuel elements clad in Zircaloy-4 alloy. This is done in collaboration with Reduced Enrichment for Research and Test Reactor. The versatile MCNP code was used to analyse the neutronics parameters given in the SAR of HEU core, thereby characterizing the core. Subsequently, the LEU core was indentified with necessary changes to the HEU MCNP model. It was ascertained that the reactivity for the LEU core with the same number of fuel pins as the HEU was inadequate, hence the fuel pins were increased from 344 to 348. The neutron flux at the irradiation sites was found to be below the nominal value at full power for the LEU and hence the nominal power was increased to 34 kW for a nominal flux value of 1 × 1012 n/cm2.s. The parameters investigated for the HEU and LEU are shown in this paper. 展开更多
关键词 NEUTRONICS MULTIPLICATION Factor Reactivity Neutron Flux
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Pseudocritical Rapid Energy Dissipation Analysis of Base-Load Electrical Demand Reduction on Nuclear Steam Supply System
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作者 Frederick Agyemang Stephen Yamoah Seth Kofi Debrah 《World Journal of Nuclear Science and Technology》 2022年第2期69-87,共19页
Effect of pseudocritical rapid energy dissipation (PRED) from Pressurizer in nuclear steam supply system of Pressurized Water Reactor, where a single event as common cause failure, of considerable reduction of base-lo... Effect of pseudocritical rapid energy dissipation (PRED) from Pressurizer in nuclear steam supply system of Pressurized Water Reactor, where a single event as common cause failure, of considerable reduction of base-load electricity demand causes the temperature of the reactor coolant system (RCS) to increase, and corresponding pressure increases in pressurizer and steam generators above set-points. The study employed the uses of MATLAB/Simulink library tools, to experimentally modelled pressure control as PRED, where the momentum of transport of kinematic viscosity fraction above pseudocritical point dissipated as excess energy, to maintain the safety of the Pressurizer and RCS and keep the water from boiling. The result demonstrated the significance of pressure vector and Prandlt number as heat transfer coefficients that provided detailed activities in 2-D contour and 3-D graphics of specific internal energy and other parameterization of fluid in the pressurizer. 展开更多
关键词 Pseudocritical Rapid Energy Dissipation Pseudocritical Saturation PARAMETERIZATION Internal Energy Pressure Vector Heat Transfer Coefficient
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Neutronics analysis of a subcritical blanket system driven by a gas dynamic trap-based fusion neutron source for ^(99)Mo production 被引量:1
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作者 Hou-Hua Xiong Qiu-Sun Zeng +5 位作者 Yun-Cheng Han Lei Ren Isaac Kwasi Baidoo Ni Chen Zheng-Kui Zeng Xiao-Yu Wang 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2023年第4期14-25,共12页
Gamma-emitting radionuclide ^(99m)Tc is globally used for the diagnosis of various pathological conditions owing to its ideal single-photon emission computed tomography (SPECT) characteristics.However,the short half-l... Gamma-emitting radionuclide ^(99m)Tc is globally used for the diagnosis of various pathological conditions owing to its ideal single-photon emission computed tomography (SPECT) characteristics.However,the short half-life of ^(99m)Tc (T_(1/2)=6 h)makes it difficult to store or transport.Thus,the production of ^(99m)Tc is tied to its parent radionuclide ^(99)Mo (T_(1/2)=66 h).The major production paths are based on accelerators and research reactors.The reactor process presents the potential for nuclear proliferation owing to its use of highly enriched uranium (HEU).Accelerator-based methods tend to use deuterium–tritium(D–T) neutron sources but are hindered by the high cost of tritium and its challenging operation.In this study,a new ^(99)Mo production design was developed based on a deuterium–deuterium (D–D) gas dynamic trap fusion neutron source (GDT-FNS) and a subcritical blanket system (SBS) assembly with a low-enriched uranium (LEU) solution.GDT-FNS can provide a relatively high-neutron intensity,which is one of the advantages of ^(99)Mo production.We provide a Monte Carlo-based neutronics analysis covering the calculation of the subcritical multiplication factor (k_(s)) of the SBS,optimization design for the reflector,shielding layer,and ^(99)Mo production capacity.Other calculations,including the neutron flux and nuclear heating distributions,are also provided for an overall evaluation of the production system.The results demonstrated that the SBS meets the nuclear critical safety design requirement (k_(s)<0.97) and maintained a high ^(99)Mo production capacity.The proposed system can generate approximately 157 Ci ^(99)Mo for a stable 24 h operation with a neutron intensity of 1×10^(14) n/s,which can meet 50%of China’s demand in 2025. 展开更多
关键词 Gas dynamic trap Fusion neutron source Molybdenum-99 Low-enriched uranium Subcritical blanket system
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Management System Activities of the Operation and Utilization of GHARR-1
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作者 Edward Shitsi Henry Cecil Odoi +10 位作者 Kwame Gyamfi Philip Dordoh-Gasu Isaac Kwasi Baidoo Edward Oscar Amponsah-Abu Emmanuel Kwesi Boafo Samuel Yao Ganyaglo Samuel Boakye Dampare Henry Kwame Obeng William Osei-Mensah Wilfred Sedofia Massiasta Robert Ekow Quagraine 《World Journal of Engineering and Technology》 2023年第4期807-826,共20页
The Ghana Research Reactor-1 (GHARR-1) is a 34 kW low enriched uranium (LEU) Miniature Neutron Source Reactor (MNSR), tank-in-pool type and cooled by natural circulation under atmospheric pressure operating conditions... The Ghana Research Reactor-1 (GHARR-1) is a 34 kW low enriched uranium (LEU) Miniature Neutron Source Reactor (MNSR), tank-in-pool type and cooled by natural circulation under atmospheric pressure operating conditions. GHARR-1 is owned by Ghana Atomic Energy Commission (GAEC) and operated by National Nuclear Research Institute (NNRI), one of the institutes of GAEC. GHARR-1 is housed by Nuclear Reactors Research Centre (NRRC), one of the Centres of NNRI. Management/Administration, Radiation protection, Reactor operation and maintenance, Reactor utilization and Physical protection are the various systems/units that integrate to manage the activities of operation and utilization of GHARR-1 in addition to the quality assurance and quality control management system of the research reactor facility. The GHARR-1 which is currently in operation follows a robust maintenance culture adopted by the management system and this has made it possible to keep the reactor in operation with minimal interruption. The management system activities adopted at the Centre to ensure safety of the workers, public and the research reactor facility include authorization of the operation of the reactor for any experiments/modifications;providing material and financial resources for maintaining the research reactor facility;following standard procedures while carrying out Neutron Activation Analysis;participation in IAEA proficiency test;irradiation sites/positions characterization;following standard procedures while carrying out reactor operation and maintenance including reactor and pool water purification and other related activities;monitoring radiation levels in the controlled, supervised and uncontrolled areas of the research reactor facility as well as during reactor operation and maintenance;controlling the physical entry of the workers and public into the research reactor facility;and ensuring that the security structures provided to protect the reactor facility are functioning properly. The thorough knowledge on the functions of the various components that make up the electrical/electronic and control systems of the reactor has been observed to be important for continuous successful maintenance of the research reactor to keep the reactor in operation. This work provides some management system activities adopted to monitor the activities of the research reactor operation and utilization to guarantee safety of workers, public and the environment as well as to safeguard a continuous operation of the research reactor. These management system activities adopted among others, are in the form of Monitoring Forms provided for monitoring the activities of the research reactor operation and utilization in order to ensure standard procedures and specifications are followed and quality services are rendered to the public. 展开更多
关键词 Management Systems Quality Assurance and Quality Control Research Re-actor Operation and Utilization Monitoring Forms Ghana Research Reactor-1 (GHARR-1)
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Microbiological Quality of Chicken Sold in Accra and Determination of D<sub>10</sub>-Value of <i>E. coli</i> 被引量:3
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作者 Abraham Adu-Gyamfi Wellington Torgby-Tetteh Victoria Appiah 《Food and Nutrition Sciences》 2012年第5期693-698,共6页
Chicken is an excellent source of good quality protein, but it is highly susceptible to microbial contamination and often implicated in food borne disease. The microbiological quality of chicken at different retail ou... Chicken is an excellent source of good quality protein, but it is highly susceptible to microbial contamination and often implicated in food borne disease. The microbiological quality of chicken at different retail outlets (supermarkets, local markets and farms) in Accra was investigated, and D10-values of E. coli in refrigerated and frozen retailed chicken was determined. The microbiological quality of chicken was studied by analyzing 27 chicken thigh samples collected from the retail outlets. D10-value of Escherichia coli was determined by using a linear regression model after gamma irradiation of inoculated chicken samples with doses of 0, 150, 300, 450, 600, 750 and 900 Gy. Mean total viable counts for the supermarkets, local markets and farms were 6.46, 6.91 and 6.57 log10 cfu/g respectively. Mean total coliform counts for the supermarkets, local markets and farms were 3.80, 3.46 and 3.14 log10 cfu/g respectively and the mean S. aureus counts were also 2.32, 2.28 and 2.70 log10 cfu/g respectively. There were no significant differences (p > 0.05) between the mean total viable count, total coliform counts and S. aureus count for the supermarkets, local markets and the farms. Mean counts of E. coli detected at the supermarket, local markets and farms were 1.27, 2.59 and 2.74 log10 cfu/g respectively. Salmonella spp. was detected in 2 out of the 27 samples. Fifty-two percent and 70% of samples respec-tively had total viable counts and total coliform counts within the microbial safety standards. Mean D10E. coli were 0.22 and 0.32 kGy in refrigerated and frozen chicken respectively. Presence of pathogenic bacteria in fresh chicken sold in some retail outlets in Accra was confirmed. Low D10-values of E. coli especially under refrigerated conditions suggest susceptibility to low dose irradiation and possibility of controlling spoilage and pathogenic microflora of fresh poultry. 展开更多
关键词 CHICKEN Microbiological Quality Irradiation E. COLI D10-Value
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Water use efficiencies of maize cultivars grown under rain-fed conditions 被引量:2
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作者 Daniel Kwasi Asare Justice Okona Frimpong +1 位作者 Emmanuel Ofori Ayeh Harry Mensah Amoatey 《Agricultural Sciences》 2011年第2期125-130,共6页
Enhancing water use efficiencies of rain-fed maize is a requirement for sustainable maize production, particularly in areas prone to low/drought and erratic rainfall patterns. This study was conducted to assess the re... Enhancing water use efficiencies of rain-fed maize is a requirement for sustainable maize production, particularly in areas prone to low/drought and erratic rainfall patterns. This study was conducted to assess the relationship between total biomass/grain yield and water use efficiencies of three maize cultivars (Golden Crystal, Mamaba and Obatanpa) grown under rain-fed conditions in a coastal savannah agro-ecological environment of Ghana. Results of the study showed that a unified linear model, WUETDM = 0.03TDM with R2 = 0.765 and P ≤ 0.001, described adequately the relation between wa-ter use efficiency and total biomass (dry matter), which is applicable for the three maize cultivars for both the major and minor cropping seasons. A linear model could only, however, describe adequately well the relation between WUEGY and GY for the major (WUEGY = 0.001GY – 0.67;R2 = 0.996;P ≤ 0.001) and minor (WUEGY = 0.002GY + 0.289;R2 = 0.992;P ≤ 0.001) cropping seasons for all the maize cultivars. The linear models developed for the maize cultivars, re-lating WUEGY to GY, are specific to each of the crop growing seasons, indicating that seasonal rainfall impacts significantly on harvest index of the maize cultivars but differently in each of the crop growing seasons as a results of dif-ferences in seasonal rainfall. However, the models could be used to estimate water use efficiencies of each of the three maize cultivars given the appropriate TDM and GY as inputs for the environment under which the study was conducted. 展开更多
关键词 Water Use EFFICIENCY MAIZE CULTIVARS Rain-Fed
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Impact of Small Scale Irrigation Technologies on Poverty Alleviation among Peri-urban and Urban Farmers 被引量:2
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作者 Kwamina Ewur Banson Daniel Asare +2 位作者 Lee Heng Joe Frederick Cobbinah Alex Adu-Sarkodieh 《Journal of Life Sciences》 2014年第2期142-151,共10页
关键词 灌溉技术 小规模 农民 生态可持续发展 扶贫 城市 城郊 生产效率
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Level of Practical Skills in Personnel Dosimetry Monitoring and the Laboratory Experience with Different Types of TLD Readers
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作者 H. K. Agyeman B. J. B. Nyarko +12 位作者 S. Osae F. Adeku E. O. Darko J. K. Amoako J. Owusu-Banahene S. Inkoom B. K. Agyeman P. Manteaw E. Amoatey G. O. Aseidu P. Appiah B. D. Bekoe D. F. Charles 《International Journal of Medical Physics, Clinical Engineering and Radiation Oncology》 2019年第3期141-150,共10页
This study was carried out to analyze individual annual dose records of diagnostic radiology staff at forty-eight (48) different medical facilities in urban and rural Region of Ghana for the period of 2011-2015. The m... This study was carried out to analyze individual annual dose records of diagnostic radiology staff at forty-eight (48) different medical facilities in urban and rural Region of Ghana for the period of 2011-2015. The monitored dose data were extracted from the Radiation Protection Institute of the Ghana Atomic Energy Commission’s database called the Dose Management System (DMS). The doses of these OEWs analyzed, are divided into four subgroups namely;general radiographers, radiologists, computed tomography (CT) technologists, fluoroscopy technologists. The dose distribution, collective dose and mean annual dose were determined. A total of 1574 OEWs were monitored comprising of 56% radiographers, 15% radiologist, 21% computed tomography (CT) technologists and 8% fluoroscopy technologists. The average annual effective dose ranged from 0.36 to 1.70 mSv with radiographers receiving the largest. Fluoroscopy technologist recorded the least annual total collective effective dose value of 0.1 person-Sv. The study contributes to the existing works to promote a more comprehensive personal monitoring service for OEWs. Continued analysis of occupational doses should be an integral component of institutional radiation safety programs in Ghana. 展开更多
关键词 Doses RADIOLOGIST Occupationally EXPOSE Workers Dose Management System and Database
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