International Journal of Engineering and Applied Physics

Assessment of wind energy potential in Nyala: South Darfur state, Sudan

Wed, 25 Sep 2024 00:00:00 +0000

Renewable energies constitute an excellent solution for both the increasing of energy consumption and environment problems. Among these energies, wind energy is very interesting, caring and attentiveness. Whereas, the wind energy is the subject of advanced research. In the development of wind turbine, the design of its different structures is very important. It will ensure: the robustness of the system, the energy efficiency, the optimal cost and the high reliability. In this paper, descriptive method was used for wind energy assessment in south Darfur state, where the wind speeds, atmospheric pressure and temperature were taken from Sudanese Meteorological Authority, statistically analyzed using statistical program as well as the seasonal distribution of wind speeds in the region. The results showed that the wind energy according to the analyzed data is too promised. The study confirmed that south Darfur state can be established wind energy farms in nowadays or in the future to generate electricity in order to solve the energy problems that the region has suffered throughout history of Sudan.

Optimization of concrete produced from industrial waste and fibre using regresion model

Funminiyi Oyekunle, Prof. B. D. Oluyemi-Ayibiowu, Adeola Akinsuyi — Wed, 25 Sep 2024 00:00:00 +0000

This 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.

Mixer Circuits Design and Performance Analysis using Planar Schottky Diodes – Simulation with MWO

Laith Al Taan; Samir Ahmad — Wed, 09 Oct 2024 00:00:00 +0000

Three mixer circuits were designed: a single mixer, a balanced single mixer, and a double-balanced mixer, all utilizing planar Schottky diodes (Au/GaAs) for microwave frequencies. The design and simulation were conducted using the Microwave Office program. The performance of these designs was compared with a previous reference circuit by Rohyed, which also employed a planar Schottky diode. The comparison revealed that the conversion loss (CL) was lower in the single-diode mixer compared to the single-balanced mixer at fixe frequency 6GHz; the double-balanced mixer exhibited the best performance overall, and the single-balanced mixer showed slightly higher conversion loss. The noise figure remained relatively constant across the designs at operating frequencies for each circuit. Overall, the design effectively balanced conversion loss and Noise Figure.

Mathematics of skateboard quarter pipe construction

Thomas Günther — Wed, 09 Oct 2024 00:00:00 +0000

The present article provides a detailed mathematical treatise on the geometry of skateboard transition ramps. These usually form a circular segment shape and are used in skateboarding for transitioning from a horizontal plane to another angle of incline. Transitions play a crucial role in the flow of skateparks and are required, for example, for quarter pipes, mini ramps, vert ramps, or jump ramps. Skateboarding has been an Olympic sport since 2023, yet many publicly funded skateparks still do not meet the demands of the sport. On one hand, there is often a lack of willingness from authorities to engage with the athletes beforehand; on the other hand, the people involved in the planning process often lack the necessary experience and mathematical expertise to perfectly fulfill the users' needs. Thoughtful planning is particularly crucial for ramps with curved surfaces to ensure the flow of the skatepark. In addition to the mathematical analysis, source codes for programs are provided to make the calculations as convenient as possible for all users.

Radionuclides Distribution in Al-Qayyarah Oil Wells and refinery in Nineveh Government, Iraq

Zainab Mowafaq Marie, Laith Najam, Taha Yaseen Wais, Berivan F. Namq — Wed, 25 Sep 2024 00:00:00 +0000

This 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 (Ra_eq) was 81.97 Bq/kg, the absorbed gamma dose rate (D_R) 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 (H_ex) was 0.22, the internal hazard (H_in) 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.

Experimentation and modeling dehumidified air dryer

Andry Thierry RANDRIANARINOSY — Wed, 25 Sep 2024 00:00:00 +0000

Drying 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.

The effective Young's modulus of porous exponential functionally graded material

Lan Hoang That Ton — Wed, 09 Oct 2024 00:00:00 +0000

The effective Young’s modulus of porous exponential functionally graded material is presented in this article. Matlab software is used to plot the change in value of this quantity along the thickness of the structure related to this material.

Natural Phenomena-Induced Electrical Faults Impacts in the Distribution System of Lagos

SAMSON AKANNI, PROF MELODI A. O, DR. T. O ALE — Wed, 09 Oct 2024 00:00:00 +0000

This 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.

Optimizing Green Concrete Brick Production with Rice Husk and Glass Waste: A Path to Sustainable Building

Ms.Bandhavya G B Gowda, Prashath S, Sandeep K, Bindhushree G B — Wed, 25 Sep 2024 00:00:00 +0000

This study investigates the performance of green composite cement bricks (GCB) incorporating waste glass powder and rice straw additives by conducting a series of compression tests across five distinct mixes (Mix A through Mix E). Each mix varied in the percentage composition of waste glass powder (ranging from 5% to 25%) and rice straw (ranging from 10% to 50%). A total of 15 bricks were cast to evaluate their compressive strength over different curing periods.The compression tests were performed at 7 days, 14 days, and 28 days of curing to assess the development of compressive strength over time. The results for each mix were analyzed to determine the impact of varying compositions on the bricks' structural performance. Additionally, compression tests were also conducted on conventional bricks, which are not standardized in size and whose dimensions vary by region. Conventional bricks typically have lengths ranging from 210 mm to 250 mm, widths from 100 mm to 130 mm, and thicknesses from 70 mm to 100 mm.The findings from this study provide valuable insights into the feasibility of using green composite bricks as a sustainable construction material, highlighting their compressive strength performance compared to conventional bricks and demonstrating the effectiveness of incorporating waste materials in enhancing brick properties.