Azhar Malik

Pakistan Institute of Engineering and Applied Sciences | PIEAS · Department of Nuclear Engineering

https://authors.elsevier.com/c/1ifsT,M3GFfCXf

This research focuses on the development and evaluation of heavy-density concrete containing Magnesium oxide and grit scale iron aggregate as potential radiation shielding material for water cooled reactors operating at temperatures between 28 ◦ C and 300 ◦ C. Concrete samples were prepared using varying proportions of grit iron scale aggregate...

In this study, a novel method to determine the surface and lateral dead layers of p-type HPGe detector is proposed to compute the full energy peak efficiency (FEPE). The method employed standard radioactive point sources 241Am, ,133Ba and FEPE measurement at low energies to estimate the thickness of frontal and lateral dead layers. The method is si...

This study examines the physical, mechanical, microstructural, and attenuation properties of high-density concrete exposed to temperatures ranging from 200°C to 1200°C. For this purpose, heavy-density concrete containing 25%, 50%, 75%, and 100% dolerite aggregates was developed and compared with three ordinary concrete mixes. Pre- and post-heated c...

Damped harmonic oscillator model based fitting of nanosecond pulsed laser induced amplitude variations of clamped vibrating circular plate is used to estimate the mechanical damping and natural frequency of the sample in current work. Laser Pulses of 50 mJ energy, 20 ns duration, and focused at a spot of 4 mm diameter at the center of the circular...

Concrete with fillers can serve as a shielding material against harmful radiation effects due to availability of materials, low cost, high strength, and adaptability in various environments. An overview of the recent developments in concrete as a gamma ray shielding material, along with important aspects of aggregates in various nuclear isotope app...

PurposeA nondestructive, noncontact approach for the estimation of elastic parameters of fully clamped thin sheet is presented in current work. Frequency response of pulsed laser impulse excited clamped thin plate is used for the estimation of elastic parameters.Methods Elastic parameters like Young’s modulus, shear modulus and Poisson ratio of ful...

This study covers development methods and a complete spectrum of physical qualities for 4th generation Nuclear Power Plant (NPP) as potential radiation shielding material at higher temperatures between 200 °C and 1200 °C. The samples were prepared using 25%, 50%, 75%, and 100% heavy density Grit Scale Aggregate (GSA) and three normal-weight concret...

Polymer matrix composite (PMCs) materials developed by room temperature vulcanization having various compositions i.e. 0, 30.1, 47.8, 59.8, 68.1 and 88.1 wt. % of tungsten incorporated in silicon rubber matrix were investigated using EGS5 Monte Carlo Code. Narrow beam geometry similar to experimental setup was modeled and validated for Monte Carlo...

CsI scintillators are widely used for the detection of gamma rays due to high light yield, high density, reasonable energy resolution, low cost and ease of operation in the field of radiation and medical physics. Alongwith other radiation detectors, it is used for 511 keV gammas emitted due to positron annihilation emitted from radiotracer injected...

Compton camera have found many applications in the fields of nuclear medicine, molecular imaging, astrophysics, industrial survey, homeland security and medical physics due to its high sensitivity, high resolution, wide field of view, compactness, low patient dose, multiple radioisotope tracing capability, and inherent 3D imaging capability. Consid...

Organic polymers like Polyethylene and Teflon are used in the most of coaxial cables for insulation purposes. When dielectric insulators are subjected to ionizing radiation, radiation induced conductivity is observed. Thus, ionizing radiation deteriorates the insulating properties of these insulators resulting in a steady state current during the r...

High Purity Germanium (HPGe) radiation detectors are widely used for the gamma ray spectroscopy due to their best energy resolution. However, the detector response including Absolute Full Energy Peak (AFEP) efficiency, photo-fraction, Compton-to-photo ratio, etc., depends on the different physical parameters. The main advantage of Monte Carlo simul...

*Quantitative Positron Emission Tomography (PET) studies require the blood sampling which is very inconvenient and painful for the patients, handling of radioactive samples is risky to the workers and lengthy as well as less efficient to the imaging centers. Various approaches are proposed to reduce the exposure to the workers and number of blood s...

In order to obtain plasma time activity curve (PTAC), input function for almost all quantitative PET studies, patient blood is sampled manually from the artery or vein which has various drawbacks. Recently a novel compact Time over Threshold (ToT) based Pr:LuAG-APD animal PET tomograph is developed in our laboratory which has 10% energy resolution,...

Ce(+3): Gd3Al2Ga3O12 (Ce:GAGG) is expected to be promising scintillator for PET, SPECT, and gamma camera applications because of its attractive properties. We designed a Compton camera based on Ce:GAGG, both as scatterer and absorber, for imaging and radioactivity measurement of point sources. The two important parameters sensitivity and spatial re...

Kinetic modeling and dynamic acquisition along with blood sampling is the most accurate method for the PET quantitative studies. However, the blood sampling is very inconvenient and painful for the patients, handling of radioactive samples is risky to workers and time consuming as well as less efficient to imaging centers. Various approaches are pr...

The quality of the optical pulse propagating through single mode fiber is degraded due to fiber loss, group velocity dispersion (GVD) and self phase modulation (SPM). We present and compare our results of the variation in peak power (and hence broadening or compression of the pulse) of a Gaussian pulse propagating through single mode fiber in norma...