Arc discharge technique was modified by using non-traditional rotational electrode and AC applied voltage. Two different systems were designed and locally fabricated to improve the properties of prepared yields. The rotational speed of the target, shape of the electrode and type of dielectric medium have a great effect on the yield, shape, size, stability and mass production. Ethanol as a dielectric medium was used in this study and compared with published works. The yields were characterized by Particle Size Analyzer, high-resolution electron microscope (HRTEM), inductively coupled plasma optical emission spectrometry (ICP-OES), X-ray diffraction (XRD), the ultraviolet–visible spectrophotometer (UV–Vis) and Zeta potential. All characterizations show that spherical silver nanoparticles are successfully produced for both systems. The results showed that the size of the nanoparticles prepared by cylindrical rotating electrode system is (23.45 ± 0.16) compared with those produced by disk rotating electrode system with size (26.83 ± 0.44). According to the obtained data the shape of the used cathodes was greatly affected the mass production rate of the nanoparticles, it was found that the rate in case of the cylindrical cathode was (46 ± 0.6 mg/min) compared with those prepared in case of disk cathode (34 ± 0.9 mg/min) and both rotational electrodes yielded more than simple arc discharge (23 ± 0.8 mg/min).

Synthesize of Silver Nanoparticles by Arc Discharge Method Using Two Different Rotational Electrode Shapes

An empirical formula to calculate the full energy peak efficiency of scintillation detectors

STUDY ON THE EFFECT OF THE SELF-ATTENUATION COEFFICIENT ON γ-RAY DETECTOR EFFICIENCY CALCULATED AT LOW AND HIGH ENERGY REGIONS

Mass attenuation coefficients (µm), total atomic cross-sections (σt), molar extinction coefficients (), electronic cross-sections (σe), effective atomic numbers (Zeff) and electron densities (Neff) have been computed for few nylons that are polymers, namely, nylon 6 (C6H11ON), nylon 1,1 (C11H21ON), nylon 6,6 (C12H22O2N2), nylon 6,9 (C15H28O2N2), nylon 6,10 (C16H30O2N2) and nylon 6,12 (C18H34O2N2) using narrow beam good geometry set-up. In the present investigation, radio-nuclides 57CO, 133Ba, 137Cs, Co57, Ba133, Cs137, Na22, Mn54 and Co60 emitting energies 122, 356, 511, 662, 840, 1170, 1275 and 1330 keV have been counted by a NaI (Tl) detector coupled with the 8 K multichannel analyzer. Values of µm, σt and σe decrease with increasing energy of gamma photons due to the dominance of Compton scattering in the selected energy range. Effective atomic numbers of chosen samples tend to be almost constant as a function of energy. It is clearly observed from the computed results that the among the chosen...

Detection of new polymer materials as gamma-ray-shielding materials

The present work was carried out to find out the gamma ray shielding properties and to study the effects using an NaI (Tl) detector using radioactive sources 57Co, 133Ba, 137Cs, 54Mn, 60Co and 22Na at energies 122, 356, 511, 662, 840, 1170, 1275 and 1330 keV, for some chemicals, namely, sodium thiosulfate (Na2S2O3), benzoic acid (C7H6O2), sodium hydroxide (NaOH), poly vinyl alcohol (PVA) (C2H4O), potassium nitrate (KNO3), naphthalene (C10H8). Mass attenuation coefficient (µm) values obtained from the experiment were used to determine the effective atomic numbers (Zeff) and effective electron densities (Neff), atomic cross-sections (σt) and electronic cross-sections (σe); it will be observed from the present work that the variation in the obtained values is only due to the increase or decrease in the gamma ray energy and the chemical composition of the sample. It was seen that the calculated and obtained values showed good agreement. The investigated data are useful in the electronic industry, plas...

Effects of gamma irradiation on some chemicals using an NaI (Tl) detector

In this work we calibrated the NaI(Tl) scintillation detectors (5.08 × 5.08 cm2 and 7.62 × 7.62 cm2) and the Full Energy Peak Efficiency (FEPE) for these detectors have been calculated for point sources placed at different positions on the detector axis using the analytical approach of the effective solid angle ratio. This approach is based on the direct mathematical method reported by Selim and Abbas [1,2] and has been used successfully before to calibrate the cylindrical, parallelepiped, and 4π NaI(Tl) detectors by using point, plane and volumetric sources. In addition, the present method is free of some major inconveniences of the conventional methods.

https://file.scirp.org/pdf/WJNST20120300006_25767040.pdf

Determination of Full Energy Peak Efficiency of NaI(Tl) Detector Depending on Efficiency Transfer Principle for Conversion Form Experimental Values

In gamma-ray spectrometry, the analysis of the environmental radioactivity samples (soil, sediment and ash of a living organism) needs to know the linear attenuation coeffi cient of the sample matrix. This coeffi cient is required to calculate the self-absorption correction factor through the sample bulk. In addition, these parameters are very important because the unidentifi ed samples can be different in the composition and density from the reference liquid sources which are usually used for effi ciency calibration in the radioactive monitoring process. The present work is essentially concerned to introduce a mathematical method to calculate the linear attenuation coeffi cient without using any collimator. This method was based mainly on the calculations of the effective solid angle subtended by the source-to-the detector confi gurations, the effi ciency transfer technique and the average path lengths through the samples itself. The method can be used as a tool for the calculation of the linear attenuation coeffi cient of unidentifi ed materials with good facility to use it in the calibration process of γ-ray detectors, particularly in the study of soil samples. The results are compared with the data from NIST-XCOM to show how much the results are in close agreement and to give the validity of the approach. Case Report Using Mathematical Procedure to Compute the Attenuation Coeffi cient in Spectrometry Field Mohamed Elsafi 1, Mona M Gouda1, Mohamed S Badawi1,2*, Abouzeid A Thabet3, Ahmed M El-Khatib1, Mahmuod I Abbas1 and Kholud S Almugren4 1Physics Department, Faculty of Science, Alexandria University, 21511 Alexandria, Egypt 2Department of Physics, Faculty of Science, Beirut Arab University, Beirut, Lebanon 3Department of Medical Equipment Technology, Faculty of Allied Medical Sciences, Pharos University in Alexandria, Alexandria, Egypt 4Physics Department, Faculty of Science, Princess Nourah Bint Abdulrahaman University, 11544-55532 Riyadh, Saudi Arabia *Address for Correspondence: Mohamed S Badawi, Physics Department, Faculty of Science, Alexandria University, 21511 Alexandria, Egypt, Tel: +201005154976; Email: ms241178@hotmail.com Submitted: 19 December 2016 Approved: 03 February 2017 Published: 06 February 2017 Copyright: 2017 Elsafi M, et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

/pdf/using-mathematical-procedure-to-compute-the-attenuation-4zicao4rk7.pdf

Abouzeid Ahmed Thabet

Papers

Determination of Full Energy Peak Efficiency of NaI(Tl) Detector Depending on Efficiency Transfer Principle for Conversion Form Experimental Values

Using Mathematical Procedure to Compute the Attenuation Coeffi cient in Spectrometry Field

Copper nanoparticles obtained by arc discharge method: synthesis, characterization, and properties.