Electronic and Structural Properties of an Undoped Sodium Iodide

This 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

Soil To Plant Transfer Factors of Natural Radionuclides in Khat (Catha endulis) from Igembe South Subcounty, Kenya

This 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

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

This 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

An Influence of Recycled Concrete Aggregate and Treated Waste Water Containing 50% GGBS Content in Light weight Concrete Mixes

Extraction 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

Approximated transverse deflection of sandwich beam with 2D-FG and ceramic face sheets and 1D-FG core

The 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

The Study of the evolution of certain electrical properties of a carboxymethyl cellulose by irradiating it and adding different concentrations of materials at different temperatures

       There are two parts to this manuscript. In the first part, thin films were prepared by doping carboxymethyl cellulose with Polyanionic cellulose low viscosity, with a concentration of 73% CMCHV and 27% PACLV, then CMC HV/PAC LV thin films were exposed to different X-ray photon doses (0, 200, 400, 600, and 800 cGy). But second Part were prepared the thin films by dissolving 8 g of CMCHV in 50 ml of distilled water, then adding NaCl and ZnONPs in concentrations (0.00, 11, 20, 27, 33 and 38%). The intensity of the direct current I was measured for all samples by changing the potential difference V at different temperatures (T).       The measurement results of all samples studied in this research indicate that the conductivity and current density increase with an increase in the X-ray photon doses in the irradiated samples or with an increase in the concentrations of NaCl, ZnOPNs and also increases with increasing temperature, but the conductivity and current density increase more when NaCl is added than when ZnO PNs are added. By using these results, several areas can benefit, such as industry, scientific research, etc

Transverse deflection of sandwich beam with 2D-FG skins and ceramic core

The 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

Gamma Radiation Effects on The Performance of The CdSe Thin Film for Photodetector Application

Cadmium 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

Solving Problem of Robotic Control of Advanced Missile Via Integral GuptaTransform

A new technique has been brought into play in this article for solving the second-order linear differential equation representing the problem of automatic or robotic control of advanced missiles. The problem of robotic control of the Advanced missile is one of the problems represented by second-order linear differential equations. The Integral Gupta transform (GT) has not at any time been put in an application to solve the problem of robotic control of the advanced missile. In the article, Integral Gupta transform (GT) has been brought into play to solve the problem of robotic control of the advanced missile and reveals that it is a constructive tool for solving such problems. The graphs of the solutions obtained are plotted to indicate the generality and clarity of the proposed method

An Optimized Sandwich Bumper Beam for Child Occupant Head Injury Prevention

Child 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