Faculty Publications

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Author: search.filters.author.Narasimhan, M.C.Subject: search.filters.subject.Shielding

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    Gamma radiation shielding characteristics of concrete mixes-the state of art
    (2013) Santhoshkumar, M.; Narasimhan, M.C.; Karkera, B.
    In this paper, initially the interaction of gamma radiation with materials in general and concrete in particular are discussed. The state-of-art attempts made in different parts of the world, in improving the gamma radiation shielding properties by incorporating alternate/additional ingredients in concrete mixes are discussed. Such incorporation may be in terms of changes in any of the binder, coarse or fine aggregate components of the concrete mixes. The usage of materials such as mineral admixtures, high density solid wastes and fibres is also reported. The possible use of other mineral materials in concrete mixes for enhanced shielding performance against gamma radiation in nuclear installations is brought out. A brief review of the mix design parameters controlling shielding performance of concrete mixes is also cited. An attempt has been made to compare the shielding performances of different concretes by comparing their linear attenuation co-efficient values (μ) reported in the literature. In view of the exponential surge in γ-ray sources in nuclear industry this review is relevant to save the planet earth from an impending global disaster as well as introducing radiation in industries, food preservation, nuclear medicine and many other such applications. © 2013 CAFET-INNOVA TECHNICAL SOCIETY.
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    Effect of mix parameters and hydrogen loading on neutron radiation shielding characteristics of latex modified concrete mixes
    (Elsevier Ltd, 2015) Malkapur, S.M.; Satdive, H.; Narasimhan, M.C.; Karkera, N.B.; Goverdhan, P.; Sathian, V.
    With the tremendous surge in the usage of radioactive materials in industry, education and research, medicine and other fields, it becomes a concern to protect the working personnel and common people around, from hazardous radiation leakages that may seriously affect their health. Among the different types of radiation, gamma and neutron radiations require adequate shielding. There have been several attempts to develop newer concretes and evaluate their neutron radiation shielding characteristics. In the present study, an attempt has been made to study the effect of varying the mix parameters and hence the resulting total hydrogen content on the neutron radiation shielding characteristics of Latex Modified Concrete (LMC) mixes. The experiments are planned in such a way that the hydrogen content of the mixes is varied by controlling the mix parameters i.e., cement content, water/cement ratio and polymer/cement ratio of LMC mixes. The results are statistically analyzed. It is found that definite improvements could be achieved in neutron radiation shielding characteristics of LMC mixes as compared to ordinary concrete, with the increase in hydrogen concentration effected by changes in mix parameters. © 2015 Elsevier Ltd All rights reserved.
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    Neutron radiation shielding properties of polymer incorporated self compacting concrete mixes
    (Elsevier Ltd, 2017) Malkapur, S.M.; Divakar, L.; Narasimhan, M.C.; Karkera, N.B.; Goverdhan, P.; Sathian, V.; Prasad, N.K.
    In this work, the neutron radiation shielding characteristics of a class of novel polymer-incorporated self-compacting concrete (PISCC) mixes are evaluated. Pulverized high density polyethylene (HDPE) material was used, at three different reference volumes, as a partial replacement to river sand in conventional concrete mixes. By such partial replacement of sand with polymer, additional hydrogen contents are incorporated in these concrete mixes and their effect on the neutron radiation shielding properties are studied. It has been observed from the initial set of experiments that there is a definite trend of reductions in the neutron flux and dose transmission factor values in these PISCC mixes vis-à-vis ordinary concrete mix. Also, the fact that quite similar enhanced shielding results are recorded even when reprocessed HDPE material is used in lieu of the virgin HDPE attracts further attention. © 2017 Elsevier Ltd
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    Fresh and hardened properties of polymer incorporated self compacting concrete mixes for neutron radiation shielding
    (Elsevier Ltd, 2017) Malkapur, S.M.; Divakar, L.; Narasimhan, M.C.; Karkera, N.B.; Goverdhan, P.; Sathian, V.; Prasad, N.K.
    Several works in the past have reported that the hydrogen content in the hydrated concrete plays an important role in shielding the neutron radiation; higher the hydrogen content, better is the neutron radiation shielding. In this study, pulverised high density polyethylene (HDPE) material is used as an additional source of hydrogen within concrete to develop a novel class of Polymer-Incorporated Self-Compacting Concrete (PISCC) mixes for enhanced neutron radiation shielding. The HDPE material was incorporated as a partial replacement to river sand. It is found that the PISCC mixes have satisfactory fresh and hardened properties and enhanced neutron radiation shielding properties. © 2017 Elsevier Ltd