Gamma Radiation Absorption Characteristics of Concrete with Components of Different Type Materials

Nuclear facilities as nuclear power stations, nuclear research reactors, particle accelerators and linear accelerator in medical institution using concrete in building construction. The different type materials of the aggregate as component of concrete were analyzed to provide radiation protection. The energy deposited the transmission factor and the mass attenuation coefficients in ordinary and barite concretes have been calculated with the photon transport Monte Carlo software. The numerical simulations results show that using barite as an aggregate in the concrete is one of the solutions for gamma ray shielding. Thereat, it is shown non-destructive method for determining the gamma radiation absorption characteristics of concrete.11th Annual Conference of the Materials-Research-Society-of-Serbia (YUCOMAT 2009), Aug 31-Sep 04, 2009, Herceg Novi, Montenegr

Monte Carlo Analysis of the Influence of Different Packaging on MOSFET Energy Response to X-rays and Gamma Radiation

Radiation sensing MOSFETs have found numerous applications as detectors or device components in radiation fields used in nuclear industry, medical applications and space research. Monte Carlo simulations of MOSFET energy response to X-ray and gamma radiation for different packaging were performed. The photon transport Monte Carlo software FOTELP-2K10 has been adapted to obtain the energy deposited in MOSFET structure with microscopic dimensions. In this work the ratio between values of total energy deposited in the sensitive volume (thick SiO2 layer) for cases of MOSFET structure with and without package lid is presented. For this purpose is defined the shielding energy dependence factor (SDEF), and gave its value for kovar and Ti-24Al-11Nb and Ti-13Nb-13Zr alloys as lid materials

Characterization of New Structure for Silicon Carbide X-Ray Detector by Method Monte Carlo

This work presents a characterization of radiation absorption properties of silicon carbide (SiC) as semiconductor for the realization of detectors for X-rays. SiC detectors can potentially reach superior performance with respect to all the other semiconductors presently employed in hazardous environments in nuclear and space science and technology. Physics and numerical modeling of photons transport through SiC detector is incorporated in non-destructive Monte Carlo method for determining the energy deposited and dose distribution. The Monte Carlo code has been adopted for numerical simulations for different detector conditions and configurations. The X-ray characterization of new SiC structures originates the improving of design of these detector systems.12th Annual YUCOMAT Conference, Sep 06-10, 2010, Herceg Novi, Montenegr

Investigation of the Mortar and Concrete Resistance in Aggressive Solutions

Testing the influence of two aggressive solutions - sulphate and nitrate on mortar and concrete was presented in this paper. Experimental work included testing of mortar prisms with 5 % special admixture. Also, four types of concrete were exposed to aggressive solutions. The chemical resistance was tested according to the Koch-Steinegger method. As a condition for resistance in aggressive solution means that flexural strength of mortar prisms is no less than 70 % of referent prisms cured in water it can be concluded that mortar and concrete made with combination of cement and admixture presented in this investigation are not resistant to ammonium nitrate solution, but are resistant to sulphate corrosion

Investigation of the Mortar and Concrete Resistance in Aggressive Solutions

Testing the influence of two aggressive solutions - sulphate and nitrate on mortar and concrete was presented in this paper. Experimental work included testing of mortar prisms with 5 % special admixture. Also, four types of concrete were exposed to aggressive solutions. The chemical resistance was tested according to the Koch-Steinegger method. As a condition for resistance in aggressive solution means that flexural strength of mortar prisms is no less than 70 % of referent prisms cured in water it can be concluded that mortar and concrete made with combination of cement and admixture presented in this investigation are not resistant to ammonium nitrate solution, but are resistant to sulphate corrosion

Determination of Recycled Aggregate Concrete Degradation By Resonance Frequency Analysis

The evaluation of the dynamic modulus of elasticity of twelve different concrete mix proportions as a function of the density and degradations due to freeze/thaw cycles is presented in this paper. Pore system and saturation are the main factors for concrete freeze-thaw resistance. The frequency analysis of ultrasonic waves in concrete after every 25 cycles was done. Dynamic modulus of elasticity was determination by resonance frequency analysis. This parameter is 35-50% smaller for concrete with recycled bricks as aggregate than ordinary concrete. For all concrete mixes dynamic and static (measured by destructive testing) modules of elasticity were compared

Determination of Recycled Aggregate Concrete Degradation By Resonance Frequency Analysis

The evaluation of the dynamic modulus of elasticity of twelve different concrete mix proportions as a function of the density and degradations due to freeze/thaw cycles is presented in this paper. Pore system and saturation are the main factors for concrete freeze-thaw resistance. The frequency analysis of ultrasonic waves in concrete after every 25 cycles was done. Dynamic modulus of elasticity was determination by resonance frequency analysis. This parameter is 35-50% smaller for concrete with recycled bricks as aggregate than ordinary concrete. For all concrete mixes dynamic and static (measured by destructive testing) modules of elasticity were compared

The influence of nano-silica and barite aggregate on properties of ultra high performance concrete

The development of building materials with improved characteristics and their application for increasing structure durability and sustainability is one of the goals in construction sector. The main objective of this paper is to evaluate the influence of nano-silica replacement of cement (2% or 5%) and aggregate type (quartz, barite or its combination 50:50 by volume) on the properties of ultra high performance concrete (UHPC). UHPC with nano-silica and combination of barite and quartz aggregate is composite which has finer pore-size distribution, improvement in compressive and flexural strength and in radiation protection characteristics, with potential usage as building material for hospitals and nuclear facilities. (C) 2016 Elsevier Ltd. All rights reserved

Detection of DNA mutations based on analysis of multiple wavelength excitation/emission fluorescence kinetics curves in real-time PCR

The key method for therapies of various cancer types could be the molecular-targeted therapy, based on individual gene profile for each patient. One of the main procedures used for genetic testing is the real-time polymerase chain reaction (real-time PCR). Physical principle behind real-time PCR procedure is the fluorescence. Fluorescence labeled probes (primers) is attached to quenchers. Upon reaction of polymerization, quenchers are removed, and the fluorescence emission intensity increases in time. Emission spectra shape and its maximum position can differ if the fluorophore was present in different microenvironment. That property is widely exploited in fluorescence spectroscopy and chromatography. This paper, for the first time, describes utilization of full spectroscopic potential of multichannel excitation/emission filter sets in real-time PCR device. Instead of monitoring fluorescence intensity in time for a single fluorescence emission channel, the ratio values of three different kinetics curves were calculated and analyzed by applying k-means clustering and dendrogram analysis. Obtained results have shown that described analytical improvement provides identification of nine different groups of mutations if the commercial QIAGEN (R) EGFR PCR Kit was used. Method can be applied to any kit, capable to simultaneously detect several different mutations

Detection of DNA mutations based on analysis of multiple wavelength excitation/emission fluorescence kinetics curves in real-time PCR

The key method for therapies of various cancer types could be the molecular-targeted therapy, based on individual gene profile for each patient. One of the main procedures used for genetic testing is the real-time polymerase chain reaction (real-time PCR). Physical principle behind real-time PCR procedure is the fluorescence. Fluorescence labeled probes (primers) is attached to quenchers. Upon reaction of polymerization, quenchers are removed, and the fluorescence emission intensity increases in time. Emission spectra shape and its maximum position can differ if the fluorophore was present in different microenvironment. That property is widely exploited in fluorescence spectroscopy and chromatography. This paper, for the first time, describes utilization of full spectroscopic potential of multichannel excitation/emission filter sets in real-time PCR device. Instead of monitoring fluorescence intensity in time for a single fluorescence emission channel, the ratio values of three different kinetics curves were calculated and analyzed by applying k-means clustering and dendrogram analysis. Obtained results have shown that described analytical improvement provides identification of nine different groups of mutations if the commercial QIAGEN (R) EGFR PCR Kit was used. Method can be applied to any kit, capable to simultaneously detect several different mutations