International Journal of Engineering and Applied Physic
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Experimentation and modeling dehumidified air dryer
Get PDFDrying process assessment depends on several complex physical phenomena. This paper develops dehumidified air dryer modeling in order to determine the humidity rate releases over time and drying period. Firstly, experimental dehumidified air dryer devices much with sensors were built to vaporize 5ml of water under atmospheric condition. Then, modeling based on heat and mass transfers using Colburn’s analogy with Gnielinski correlation was applied to evaluate vapor rate. Model input data use temperature, humidity and air velocity measured from censors during experimentation. As results, model shows similar trend diagram of vapor rate and drying period with experimentation. According to the model, 6690s is needed to dry 5ml of water whereas experiment shows only 5700s which represents 15.17% of an error. Under the same conditions, open air drying process takes considerably more time to dry up equivalent amount of water. Knowing vapor rate to dehydrate from various products, dehumidified air dryer model can be a useful tool to predict drying period
Radionuclides Distribution in Al-Qayyarah Oil Wells and refinery in Nineveh Government, Iraq
Get PDFThis work presents a study of radioactivity in soil samples collected from oil well sites of the Al-Qayyarah Oil Wells and refinery in Nineveh Government, Iraq. The study utilized spectroscopy system with NaI(Tl). The average activity concentrations observed were 30.58±0.38 Bq/kg for 226Ra, 19.98±0.57 Bq/kg for 232Th, 292.32 ±10.28 Bq/kg for 40K. These results were compared to the average worldwide values, and it was found that the values for some sites exceeded the allowable worldwide levels. Additionally, various hazard indices were calculated. The radium equivalent activity (Raeq) was 81.97 Bq/kg, the absorbed gamma dose rate (DR) was 38.55 nGy/h, the annual effective dose rate (AEDE) was 47.28 µSv/y outdoor and 189.13 µSv/y indoor, the external hazard (Hex) was 0.22, the internal hazard (Hin) was 0.30, the gamma radiation representative level index (I?) was 0.60, the annual gonadal dose equivalent (AGDE) was 271.05, and the excess lifetime cancer risk was 165.48. Statistical analyses, including mean, median, standard deviation, kurtosis, skewness, box plots, frequency distributions, Quantile-quantile (Q-Q) plots, Pearson's correlation coefficient, principal component analysis (PCA), and cluster analysis, were conducted to further examine and explain the results
Soil To Plant Transfer Factors of Natural Radionuclides in Khat (Catha endulis) from Igembe South Subcounty, Kenya
Get PDFThis study evaluated the soil to plant transfer factors of khat (Catha endulis) to determine the absorption potential of natural radionuclides. Soil and leaves of Khat were sampled from Igembe south subcounty, Kenya and analyzed for concentrations of primordial radionuclides using a Thallium doped NaI gamma ray detector. Soil to plant transfer factors were calculated from activity concentrations and radiological safety of the ingested radionuclides was determined by annual effective dose (IAED), internal hazard index (Hin) and risk assessment parameter (RAP). Test results showed that the average soil to plant transfer factors for 232Th,238U and 40K were 0.0825, 0.143 and 1.575 respectively. The transfer factors of 40K were greater than 1 in more than 88% of the samples. The soil to plant transfer factors varies directly with energy of the gamma ray emitted and inversely with activity concentration of the radionuclides. The average IAED, Hin, and RAP were 1.136±0.390mSv/y, 0.210±0.070, 0.0568±0.021% respectively. Radiation hazard indices were within the safe limits and the fatality percentage was negligible. Therefore, there is no radiation risk associated with chewing of the sampled khat, and most of the radionuclides present in soil are not absorbed by Khat
An Influence of Recycled Concrete Aggregate and Treated Waste Water Containing 50% GGBS Content in Light weight Concrete Mixes
Get PDFExtraction of natural aggregates is expensive and has a huge impact on the environment. The main issues in sand and gravel mining are the large areas that are affected, ground water level changes, illegal mining, unsuitability of desert and marine sand, and costs of transport. Metallurgical waste can be used as a substitute for natural aggregates, the waste is recycled and the use of natural aggregates is reduced. Environmental sources are diminishing every day and hence, usage of available sources become even more important..The novelty of this research reports the experimental examination of applying Recycled Aggregate (RA), Treated wastewater (TW) and GGBS in concrete. Four groups of mixes were developed (Groups NW, TW, NWG, and TWG) with each group consisting of four mixes, providing a total of 16 mixes. Group NW: 100% Natural Water (NW) with different percent ratio of RA contents Group TW: 100% Treated waste water (TW) with different percent ratio of RA contents Group NWG: 100% Natural Water (NW) and 50% GGBS (replacement with Portland cement [PC]) with different percent ratio of RA content Group TWG: 100% TW and 50% GGBS (replacement with PC) with different percent ratio of RA contents The test result are compressive strength tests after 1,7,15, and 28 days. The statistical analysis results showed that the effect on concrete compressive strength was only significant when 20% RA was used in concrete exposed to TWW with 50% replacement of GGBS
Transverse deflection of sandwich beam with 2D-FG skins and ceramic core
Get PDFThe transverse deflection of a simply supported/clamped (SS/CC) sandwich beam with two directional functionally graded (2D-FG) skins and a ceramic core, namely SW2DC, is given under uniform load. The finite element analysis based on Matlab software is applied to survey the influences of material properties on deflections. The results are then shown and compared with other results in the references to end this study
Control of A Switched Reluctance Motor Based on Asymmetric Converter and Digital Signal Controller for Forward and Reverse Mode
Get PDFThe Switched Reluctance Motor (SRM) is one of the best choices for industrial and electric vehicle applications, selected for its optimal performance. This is due to the advantages of SRM, including the use of permanent magnet-free technology and a simple construction consisting of an iron core on the rotor and stator windings. A rotary encoder is utilized to detect the rotor position due to its high precision. However, synchronization with the rotor position is required during installation to achieve optimal SRM performance. The rotor position obtained from the rotary encoder is processed by the digital signal controller to determine the firing angle on the rotor. The research objective is to control the SRM to rotate in both directions. To support this study, laboratory tests were conducted for validation by changing the phase sequence in the asymmetric converter, causing differences in the three-phase current waveforms for forward and reverse rotations. The results of this research show that the SRM can rotate bidirectionally
Natural Phenomena-Induced Electrical Faults Impacts in the Distribution System of Lagos
Get PDFThis study assessed the impacts of natural phenomena-induced electrical faults on the distribution system of Lagos, served by Ikeja and Eko electricity distribution companies. The research evaluated the frequency, technical, cost, and reliability impacts of these faults. The study employed statistical and software-based short circuit fault analyses as well as system reliability indices methods to identify the most vulnerable feeders to nature-induced faults. It also simulated the network's response to fault currents and estimated the monthly costs of nature-induced outages. For the data period, an average of 20 to 43 nature-induced faults occurred annually on the networks. The obtained fault currents ranged from 0.67kA to 0.78kA and 0.52kA to 1.02kA for the 11kV and 33kV networks, respectively, which was useful for setting up installed breakers. The estimated average monthly cost of nature-induced energy loss was found to be between ?3 million and ?143 million for Eko and between ?0.01 million and ?108 million for Ikeja. The System Average Interruption Frequency Index and System Average Interruption Duration Index did not exceed 4 and 60, respectively, on 33kV network. In conclusion, natural phenomena-induced electrical faults had significant impacts, particularly in terms of monthly costs and investments in its mitigation should be explored
Optimization of concrete produced from industrial waste and fibre using regresion model
Get PDFThis research examined the potential for reusing glass fiber, fly-ash, and quarry dust, in concrete production through partial substitution of traditional cement and sand. The study employed an experimental mix design to ascertain the compressive strength of concrete when these waste materials are incorporated. Various tests, including compressive strength, slump, and air void tests, were conducted on concrete cube samples with varying percentages of waste material substitutions. The cube samples were designed with specific proportions: fly-ash replaced cement at increments of 10%, 20%, and 30%, while glass fibers were added as an admixture at 1%, 2%, and 3%. Similarly, quarry dust replaced sand at 10%, 20%, and 30%, with glass fibers added at the same percentages. Additional cube samples were prepared with quarry dust and fly ash partially replacing sand and cement at 5%, 10%, and 15%, with glass fibers added at 1%, 2%, and 3%. These samples were subjected to a curing process in water for durations of 7, 14, 21, and 28 days. A linear regression model was developed based on forty compressive strength test results, positioning compressive strength as the dependent variable and the volume of glass fibers, quarry dust and fly ash as independent variables. A model of the form: CS = 0.216Vgf + 0.068Vqd + 0.979Vfa + 26.078 was developed where CS is the compressive strength, while Vgf, Vqd and Vfa represent volume of glass fibers, quarry dust and fly ash with their coefficients respectively. The model's findings indicate that the industrial waste that significantly enhances the compressive strength of the concrete is fly ash, followed by glass fibers, while quarry dust has minimal influence. The optimal strength achieved was 24.89 N/mm2 at 28 days when fly-ash, quarry dust, and glass fibers were combined
Design and Implementation of a Three-Phase Asynchronous Motor Drive Based on a Single Chip Three-Phase Bridge Driver IR 2132
Get PDFTechnological developments in this world are growing quite rapidly, one of which is the development of the use of electric motors. There are many types of electric motors today, for example asynchronous electric motors or often called induction motors. In its use, asynchronous motors are widely used on an industrial scale. As time went by, asynchronous motor control itself also began to develop, starting from mechanically using switches to using inverters. The use of a three-phase IGBT inverter to control a three-phase asynchronous motor will be discussed in this research. The inverter control itself will use the SPWM topology, where the SPWM topology has advantages over the PWM topology. Apart from that, this research will use a single chip three-phase bridge driver IR2132 as the IGBT driver. This IC has advantages, one of which is that it has an internal deadtime, where deadtime is very necessary in controlling the three-phase inverter so that short circuits do not occur between the legs. This research shows that with a certain DC Link input voltage, it is possible to regulate a three-phase asynchronous motor using SPWM topology to control an IGBT inverter
Gamma Radiation Effects on The Performance of The CdSe Thin Film for Photodetector Application
Get PDFCadmium Selenide thin films were deposited on glass substrates and p-type silicon substrates using pulsed laser deposition technique (Nd: YAG laser). Some of these samples were exposed to different intervals (10,20,30,40) days of gamma radiation using a 226Ra source emitting 186 KeV ?-ray. For comparison purposes, the other diodes were kept without any irradiation. Results have shown all these thin films exhibit a hexagonal structure. However, there is a new (102-SiO2) peak appeared in the irradiated thin film pattern. The crystallite size of pristine and irradiated CdSe thin films were (26.9,25.8,28.4,35.3 and 22.2) nm respectively, whereas the average grain size of the pristine film was (112.3-29.24) nm whereas for the irradiated films (45.58-33.72) nm, (61.16-42.8) nm, (55.7-36.03) nm and (53.31-43.45) nm. Results also show that the band gap increased from 2.17eV for pristine thin films to 2.28, 2.45, 2.2, and 2.28 eV for the irradiated thin films. also, I-V characteristics show the dark current decreases for the irradiated thin films. The forward current under illumination increases when exposed to small gamma radiation values and then decreases with higher exposure values. In contrast, the reverse current increases with the irradiation