Algerian Journal of Engineering and Technology (AJET)
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Measurement of radioactivity in spa waters using gamma spectrometry and evaluation of health risks
Get PDFExposure of human beings to radiation from natural sources is a permanent and unavoidable part of life on earth, in this study; we are interested in measuring the concentrations of naturally occurring radionuclides in spa water, such as 40K, 232Th, 235U, 226Ra and 238U, using gamma spectrometry with a hyper pure germanium (HPGe) detector. We analysed four samples from different regions of Algeria. The samples were imbedded in 1L vials and stored for at least 21 days to achieve secular equilibrium between 226Ra and its short-lived daughter products before analysing by gamma ray spectrometry. To assess the radiological effects of these four samples, we calculated the annual effective dose AED. The doses received by the public are calculated based on the values of specific activities of 226Ra, 232Th, 238U, 40K and 235U. The average activity concentrations for the samples were 7.4± 0.7 to 10.78± 0.70 Bq/L for 238U; 1.53± 0.09 to 3.5± 0.15 for 226Ra; 0.08± 0.01 to 1.4± 0.08 for 232Th; 2.30± 0.12 to 5.51± 0.2 for 235U and 8.06± 0.4 to 40.30± 2.11 for 40k.The estimated doses for 226Ra exceed the WHO and UNSCEAR recommended values of 0.26 mSv/y and 0.29 mSv/y respectively in all samples. The total annual effective doses for sample S02 exceed the ICRP recommended limit 1 mSv/y
Postharvest shelf life extension of Cucumber (Cucumis sativus) and Irish potato (Solanum tuberosum) using X-rays in Benue State, Nigeria
Get PDFThis paper investigates the postharvest shelf life extension of cucumber and irish potato using X-rays, in Benue State, Nigeria. The selection of samples for the research was done from the traditional markets in Gboko for similar properties as depicted in the literature. For both products, six samples each with one kept as the control sample were X-ray irradiated with 60, 70, 80, 90 and 100kVp of X-rays. An ambient storage temperature range of 27 – 30oC was recorded. The measured density, moisture content M.C (%), and pH were in the intervals: 0.934-1.201 g/cm3 , 94.98-98.67%, and 6.1-4.2 for cucumber, and 0.0874-1.0867 g/cm3 , 70.82-79.93%, and 8.9-7.2 for irish potato respectively. The percentage mass shrinkage ( dM%) of the control and 100kVp X-ray irradiated samples were: 45.0% and 31.6% for cucumber, and 23.8% and 20.5% for irish potato respectively. The mass shrinkage (dM ) was found to increase during preservation and higher kVp values extended the shelf life of the products. The 90-100kVp of X-rays was effective in preserving cucumber for an additional 7 – 8 days and irish potato for additional 10 – 15 days of storage. In essence, cucumber and irish potato can be stored by exposure to specific kVp values of diagnostic X-rays
Development of a two-row manually operated rice transplanter for smallholder farmers in Nigeria
Get PDFA two-row rice transplanting machine was developed for smallholder farmers in Nigeria using standard-approved methods and locally available materials. The transplanter was designed in such a way that one operator can operate the machine. The machine consists of ground wheels, sprockets, chain, frame, float, transplanting mechanism, seedling tray, shaft and handle. The developed rice transplanter was evaluated based on a 2 x 2 x 3 factorial experimental design arranged in a strip plot design to ascertain its operational performance. The performance parameters of the rice transplanter revealed a field capacity and efficiency of 0.0146 ha/h and 55.66%, respectively. A variation in the distance between the hills was observed. The mean values were found to be 322.9 mm. The number of seedlings dispensed per hill varied in different plots. In most cases, 2-3 numbers of seedlings are dispensed per hill. The depth of the hill varies between 23 mm to 38 mm respectively. The mean depth was found to be 30.33 mm. The mean percentage of the missing and floating hills was 40% and 45%, respectively. The missing and floating hills were high in the transplanted plot. Results obtained from the analysis of variance show that the effects of treatment tillage operation and water depth have a significant effect on the machine. Based on the result obtained it can be concluded that more performance evaluation with machine and soil parameters needs to be conducted on the machine. This technology is recommended for use in rural areas to increase productivity by rice farmers
Toxicity and risk of induced second cancer for Hodgkin Lymphoma (HL) treatment using new modalities of radiotherapy for young patients
Get PDFDuring the last decade new modalities of radiotherapy were implemented in different radiation oncology department in Algeria. Most of them are based on the concept of inverse modulated radiotherapy (IMRT), volumetric modulated radiotherapy (VMAT) and or helical tomotherapy (HT). The purpose of this study is to explore the trade-offs between cancer care, toxicities of organ’s at risk and the risk of induced second cancer in case of hodgkin lymphoma. A cohort of 20 young patients treatment plans using Field-in-Field radiotherapy (3D-FIF) were assessed using mathematical model to predict the toxicity calculated by the normal tissue complication probability (NTCP) using Lyman-Kutcher-Burman model and the estimated absolute risk (EAR) for the organ’s at risk in case of Rt and Lt lung. The associated induced second cancer risk was computed using the organ equivalent dose (OED) defined as a mechanistic model in the A Bomb survivors and hodgkin’s patients data relevant to radiotherapy. The results showed that the mean dose received at right and left lung are (7.81±4.6) Gy and (8.74±3.8) Gy respectively. The calculated NTCP for pneumonitis lung end point were 4.2% and 4.5% which correspond to EUD mean = (5.98±3.16) and (6.21±3.49) Gy. The associated estimated absolute risk of induced second cancer was obtained for Right and left lung and are 4.39±3.24 and 5.54±3.41 per 10000 P-Y. Higher risk was observed for three patients of the studied cohort. EAR and toxicity modelling is a better way to evaluate Hodgkin’s lymphoma specially when it comes of young patients where the risk of induced second cancer is more important
Sensitivity to nuclear data of Es-Salam fuel assembly eigenvalue using TSUNAMI-3D/SCALE 6.2.3
Get PDFCurrently, in the design and safety studies of nuclear reactor cores, great interest is given to sensitivity and uncertainty studies because of the deviations observed due to the values of the neutron cross sections, which are important in neutronic calculations. The main objective of this study is to evaluate the influence of neutron cross section uncertainties on the effective multiplication factor keff and its sensitivity to nuclear data. This paper presents the obtained results of the sensitivity analysis performed for Es-Salam fuel assembly using SCALE 6.2.3 package. Similarity was found with the reference direct perturbation results for some nuclides but not for others. Furthermore, the study shows that differences between the TSUNAMI-3D and the direct perturbation results vary 1.9 % for 235U, 8% for 238U up to 53% for 2H for multigroup calculations and 11% for 235U, 2 % for 238U and 53.7% for 2H in case of continuous energies calculations. These differences for the 2H nuclide, were decreased with the spatial mesh technique implemented in TSUNAMI-3D. The sensitivity analysis applied in this study could be the reference for Es Salam reactor core analyses to estimate the nuclear data uncertainty contributions to key physical parameters such as reactivity coefficients
Effect of selected admixtures on the geotechnical properties of black cotton soil
Get PDFThe effect locust bean waste ash (LBWA) and cement kiln dust (CKD) on black cotton soil (BCS) was studied. BCS was modified with 0, 2, 4, 6, 8 and 10 % LBWA and 0, 1, 2, 3 and 4 %CKD in relation to the soil dry weight. Test carried out include cation exchange capacity (CEC), Atterberg limits, compaction and shear strength test. Results show that a combination of LBWA and CKD have negative effect on the geotechnical properties of soil with exception in few cases. The CEC increased with increase in both the LBWA and CKD contents with deviations in few cases. Values of 21.9, 24, 34.1, 33.5, 32.1 and 33.8 Cmol/Kg were recorded at 0, 2, 4, 6, 8 and 10% LBWA content. Similar trend was observed for 1, 2, 3 and 4% CKD. Liquid limit generally increased with increase in LBWA content while plastic limit generally decreased. In the case of plasticity index, values increased with increase in LBWA content. Peak values were recorded at 6%LBWA content. Maximum dry density (MDD) decreased with increase in LBWA content. MDD values of 1.68, 1.67, 1.66, 1.65, 1.63 and 1.61 were recorded at 0, 2, 4, 6, 8 and 10% LBWA content. Similar trend was observed for 1, 2, 3 and 4% CKD. Optimum moisture content (OMC) increased with increase in LBWA content. Cohesion of soil decreased with increase in LBWA content. Values of 140, 110, 95, 60, 120 and 180 kN/m2 was recorded at 0, 2, 4, 6, 8 and 10% LBWA content, while angle of internal friction improved from its natural value up to 10% LBWA content. Statistical studies by means of two–way analysis of variance (ANOVA) reveal that LBWA and CKD have significant effect on the soil properties. Although the modified soil did not effectively improve the consistency and shear strength parameters of BCS, an optimal blend of 2% CKD/10% LBWA blend slightly improved the soil properties. The optimally modified soil could be utilised for lightly trafficked roads construction as sub-base materials
Investigation of the mechanical properties of annealing heat treated low carbon steel
Get PDFThe mechanical properties of steel materials usually vary under different conditions, thus choosing the suitable heat treatment is needed to obtain acceptable properties. In this research work, investigation of the mechanical properties of heat treated low carbon steel was determined using tensile tests, and hardness measurements. Also, the microstructure of the samples was characterized by means of optical microscopy. The samples of low carbon steels were sourced at local market in Nigeria. The collected samples were machined using lathe machine to a diameter of 10mm and gauge length of 30 mm. The chemical composition of the steel was determined using X-ray fluorescence spectroscopy. The mechanical properties of the heat treated and untreated samples were investigated at the temperatures of 900 ⁰C, 950 ⁰C, and 1000 ⁰C. The results obtained show that the ultimate tensile strength and percentage elongation of samples increases after heat treatment. Also, yield strength and hardness tend to decrease for all annealed heat treated samples at different temperature as compared to as received samples. The results of the microstructural analyses of the as received samples showed fine dispersion of coalesced pearlite and ferrite grain. For the annealed samples, the steel microstructures compose of martensite distributed in the ferrite matrix. However, with increase in annealing temperature to 1000 ⁰C and 1100 ⁰C cementite and ferrite grain with partial grain boundary were observed
Adsorptive, kinetic and thermodynamic investigations of Sarcocephalus latifolius leaves extract as corrosion inhibitor on alloy steel in 0.6M HCl solution
Get PDFOne of the materials that have many uses in the manufacturing, automotive, and construction industries is the alloy steel. When exposed to harsh environments this material is susceptible to deterioration and corrosion. Because of this reason, it is necessary to safeguard this valuable material. There have been many different methods used, but inhibition using particularly plant extract has reportedly been effective and acceptable to the environment. In this study, the behavior of alloy steel in 0.6M HCl at various concentrations of Sarcocephalus latifolius extract was assessed using weight loss and surface characterization methods of analysis. The plant extract's ability to inhibit corrosion increased during the weight loss experiment from 25.56% to 61.18% as concentration of the plant extract increased with a decrease in temperature from 323K to 303K respectively. Thermodynamic parameters of the inhibitory process were discovered to classify the process as feasible and spontaneous, obeying the Freundlich adsorption isotherm model's description of physical adsorption. The kinetic analysis of the inhibitory process demonstrates that it follows the first order model, with activation energy and half-life values rising with the concentration of the plant extract. In conclusion, Sarcocephalus latifolius extract is effective in inhibiting the corrosion of alloy steel in 0.6M HCl at low temperatures and higher plant extract concentrations through surface adsorption.
 
Improving biogas production from animal manure by batch anaerobic digestion
Get PDFIn Libya, even if the production of biogas started in the last years, still there is too much need to optimize the biogas resources. This paper examined improving cow, sheep, and poultry manure in two phases. The experiment was carried out in a 2000 mL digester put in bath water at 37 °C. The mixing ratio of animal manure and water used was 1:1 in 12 days of Hydraulic Retention Time (HRT). The produced gas was measured by the volumetric water replacement method. In the first phase, the best pH was chosen in the experimental test with different pH ranges. Three set-ups were prepared with different pHs (6.5, 7, 7.5). The results showed that the pH had significant effects on biogas yield, where pH 7 had the highest biogas production and pH 6.5 had the lowest. In the second phase, the effect of insulation of digester on the biogas yield of cow, sheep, and poultry manure was investigated. The experiments showed that the biogas produced from an insulated digester was higher than the transparent digester. Therefore, it is assumed that the study, which gives a maximum yield of biogas production from the batch digestion process, might meet future energy demand
Influence of frying parameters and cooking oil type on the physicochemical composition of used cooking oil in bitter yam chips production
Get PDFBitter yam is an underutilized but nutrient-dense tuber, and it has the potential of being converted to value-added bitter yam chips through the deep fat frying technique. This study aimed to investigate the influence of frying temperature, frying cycle and cooking oil type on the physicochemical composition of used cooking oil in bitter yam chips production. Response surface methodology was used to interact the effect of frying temperature (170℃, 180℃, 190℃), frying cycle (1st, 2nd and 3rd cycle) and cooking oil type (soybean oil, coconut oil and peanut oils) on the viscosity, peroxide value, colour (L*, a* and b*), iodine value, free fatty acid (FFA), p-anisidine, saponification value and refractive index of the used cooking oil. The frying cycle significantly influenced the viscosity, peroxide value, iodine value, L*, b*, FFA and p-anisidine of the used cooking oil. The quadratic effect of cooking oil type affected the a* while the quadratic effect of the frying cycle influenced the refractive index of the used cooking oil. The used coconut oil had the highest viscosity (78.74), peroxide value (3.23), iodine value (80.10) and saponification value (203.21). However, the used peanut oil had the highest L* (25.39), p-anisidine (3.44), and refractive index (1.52) while soybean oil had the highest a*(4.40), b*(1.60) and FFA (62.16) at varied frying conditions. This information would be valuable to producers of bitter yam chips on cooking oil reusability