International Journal of Engineering and Applied Physic
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Preparation and Study of the Physical Properties of CdSe Films Deposited by a Chemical Bath Method and Exposed to Neutron Irradiation: Effect of neutron irradiation on a CdSe film prepared
No full textThis study deals with the preparation of CdSe films using two sources of cadmium, (CdCl2) and (CdSO4), and studying the effect of neutron irradiation on their optical and structural properties. Using CBD method, the films were prepared on glass substrates at a temperature of 50 •C, with a deposition time of 3 hours. These films were exposed to the neutron beam from the radioactive source (Am241-Be10) with a neutron flux (3*105 n/cm2.s) and an energy of 5 MeV for 7 days. It was noted that neutron irradiation has a significant effect on the physical properties of the films. Using a UV-V spectrophotometer, the optical properties of the films were studied. It was found that the absorption coefficient (?) and the energy gap increase with irradiation, and from the following XRD, FESEM and EDX measurements, the shape and structure of the prepared and irradiated films were determined. X-ray measurements have shown that there are preferred directions for grain growth [111], [220], and [311]. It was also observed that the grain size increases, while the relative density decreases with irradiation. As for FESEM measurement, it was noted that the surface shape of the films is greatly affected when exposed to neutron radiation
Approximated transverse deflection of sandwich beam with 2D-FG and ceramic face sheets and 1D-FG core
Get PDFThe approximated numerical deflection of a sandwich beam with two directional functionally graded (2D-FG) and ceramic face sheets and one directional functionally graded (1D-FG) core, namely SW2D1DC, is presented under uniform load and various boundary conditions. The finite element code written in Matlab is applied in this article to investigate the influences of material properties on transverse deflections. The results of this article are given and compared with other results in the references to verify the feasibility of the application. This study also provides some more information about the characteristics of SW2D1DC beams
An Optimized Sandwich Bumper Beam for Child Occupant Head Injury Prevention
Get PDFChild fatalities from motor vehicle crashes are recently being considered as a global problem. Various mitigation systems have been proposed, but are still not optimum. Designing energy absorption vehicle front has been one of the methods used to minimize vehicle deceleration. This in addition to child restraint seat could help minimize child injuries especially to the most sensitive part of human body, the head. Sandwich bumper beam absorbs huge kinetic energy by plastic deformation and lead to reduction of vehicle deceleration and subsequent lower occupant injuries. In this work, optimization was carried out seeking for the optimum design of composite beam thickness ( and foam thickness ( of a sandwich bumper that will minimize Head Injury Criteria ( and ) to child occupant at 48 km/h frontal impact. Sampling design of the bumper and beam thickness applying design of experiment and finite element (FE) crash simulations using LS DYNA was applied to evaluate the three year old (3YO) child model head injury responses. Optimization models were developed which were in turn used in optimization process. The optimization was carried out using polynomial Response Surface Method (RSM) for and . The bumper beam and foam thickness that gives a minimum and of 386.6 and 311.5 respectively are 100 mm with 1 mm . Lastly, the work, suggested the need for employing the relationship that exist between child occupant response and bumper material and thickness in design considerations
Assessment of wind energy potential in Nyala: South Darfur state, Sudan
Get PDFRenewable 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
Mathematics of skateboard quarter pipe construction
Get PDFThe 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
The effective Young's modulus of porous exponential functionally graded material
Get PDFThe 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
The Study of Simulation of RC, RL and RLC Circuits Using Matlab in Teaching
Get PDFInvolvement of simulation in teaching is provide a batter support, more clear and visual operation of complex circuits to the Faculty members of electrcs circuits in classroom teaching. The simulation available for simulation of electrc circuits are MATLAb and C+ and many more. Use of the simulation in classroom teaching is provide an additional support to the Faculty members and its better then the time consuming black board practice. This paper provides a case study of electrcs circuits as RC, RL and RLC in Matlab software. Different electrcs circuit model are prepared on Matlab software and generate simulation voltage forms. This paper is helpful for to find the applications of Matlab in teaching
Electronic and Structural Properties of an Undoped Sodium Iodide
Get PDFThis work investigated the electronic and structural properties of sodium iodide using the Density Functional Theory (DFT) method implemented in the quantum espresso code. The GGA (PBE) functional with exchange correlation was used. Convergence test for the kinetic energy cut-off, k-point and lattice parameter was carried out and the parameter generated was found to be consistent with the crystallography open data base input file of the sodium iodide. Band structure was plotted, and band gap was calculated to be 3.87 eV which was found to be in the category of a semiconductor but with high resistivity and low resolution. The plot of density of state was revealed that electrons may be scarcely found within some state in the sodium iodide crystal. The research shows that sodium Iodide can be effective as a semiconductor in the presence of dopants e.g., thallium which is often used in a radiation detection
Radiological Assesment of Natural Radioactivity Levels in Selected Ceramic Tile Brands used in Kenya
Get PDFThe assessment of the radiation levels of the natural radionuclides 232Th, 238U and 40K in ceramic tiles used in Kenya has been studied. The radiometric analysis was done using a high-efficiency gamma-ray spectrometer. A total of thirty-seven (37) samples of ceramic tiles were pulverized, weighed accurately, and packaged in 250ml standard plastic containers, well labelled and stored for 28 days to attain secular equilibrium. Analysis of specific gamma energies from activities of 232Th, 238U and 40K reported activity of 53.73±2.34 Bqkg-1, 43.17±3.40 Bqkg-1, and 525.99±36.10 Bqkg-1 respectively. The variatiations in the radiation activity concetration is attributed to the composition of geological raw material used for tiles manufacturing. The average radium equivalent, absorbed dose, indoor and outdoor annual effective dose, and hazard indices (internal and external) obtained were 159.59 BqKg-1, 75.55nGyh-1, 0.28, 0.19, 0.54 and 0.43 respectively. The results obtained from the study showed that the use of ceramic tiles in Kenya does not pose any significant harmful radiation effects to users
Optimizing Green Concrete Brick Production with Rice Husk and Glass Waste: A Path to Sustainable Building
Get PDFThis 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