scholarly journals Standardization of sterilization regimes for textile materials under pandemic conditions (COVID-19) by the method of ionizing radiation

2021 ◽  
pp. 101-107
Author(s):  
Olena Cherniak ◽  
Nataliia Sorocolat ◽  
Iryna Kanytska ◽  
Ihor Bahaiev ◽  
Lina Fatieieva
Keyword(s):  
Ionizing Radiation ◽  
Gamma Radiation ◽  
Gamma Rays ◽  
Absorbed Dose ◽  
Regulatory Requirements ◽  
Mathematical Formula ◽  
Textile Materials ◽  
Medical Textile ◽  
Properties Of Materials ◽  
The Mathematical Model

Methods for sterilizing textile materials in a pandemic (COVID-19) and the disadvantages of these methods are presented. A number of modern scientific works related to the sterilization of textile materials in a pandemic are considered, aimed at developing a technology for sterilizing protective medical masks and medical suits by radiation methods using gamma radiation. As a result of the analysis, it was found that the use of gamma radiation is a very dangerous technological process since natural sources are used - gamma rays, radiation technologies with gamma radiation are difficult when disposing of spent energy sources and are not easy to maintain. For sterilization of textile materials, the method of ionizing radiation is proposed. The essence of the method is that the textile material is sterilized by accelerated electrons. The expediency of carrying out theoretical and experimental research has been determined. It was found that the main criterion for sterilization of textile materials is the absorbed dose. The absorbed dose is determined experimentally, but such a procedure is time-consuming and resource-intensive, and it is not always possible to carry it out. Therefore, to calculate the absorbed dose, it is proposed to apply the mathematical formula of the absorbed dose of medical textile materials, depending on the frequency of passage of pulses of the accelerated electron beam, conveyor speed and geometric parameters of textile materials, the mathematical formula will allow finding the optimal technological modes of the sterilization process. Using the mathematical model of the absorbed dose of radiation by the material with the proposed technology, taking into account the properties of materials, it is possible to calculate the modes of irradiation of various textile materials that differ in size, shape, and physical properties, which will make it possible to develop a system of normative modes for the technology of radiation-physical sterilization and to ensure the legislative and regulatory requirements of hygiene in conditions of a pandemic.

Registry for Chronic Radiation Sickness in a Cohort of Mayak PA Workers Exposed to Ionizing Radiation

2020 ◽  
Vol 65 (4) ◽  
pp. 87-96
Author(s):  
T. Azizova ◽  
M. Bannikova ◽  
E. Grigor'eva ◽  
G. Zhuntova ◽  
M. Moseeva ◽  
...  
Keyword(s):  
Ionizing Radiation ◽  
Gamma Rays ◽  
Absorbed Dose ◽  
Radiation Sickness ◽  
External Exposure ◽  
Annual Dose ◽  
Chronic Radiation ◽  
Males And Females ◽  
The Mean ◽  
Tissue Reactions

Purpose: To present descriptive characteristics, and structure of the chronic radiation sickness (CRS) registry prospects of its use. Materials and methods: A registry for CRS diagnosed in workers of the nuclear production facility Mayak Production Association (PA) throughout the follow-up period of 1948–2018 was established within a medical and dosimetry database ‘Clinic’ of the Southern Urals Biophysics Institute. Results: The CRS registry includes 2068 cases: 1517 (73.4 %) in males and 551 (26.6 %) in females. Almost all workers (97.9 %) with CRS were hired at the Mayak PA in 1948–1954 and chronically externally and/or internally exposed to ionizing radiation. At a date of CRS diagnosis the mean cumulative red bone marrow absorbed dose of external exposure to gamma rays was 1.1 ± 0.7 Gy in males and 1.0 ± 0.6 Gy in females; the mean annual dose was 0.46 ± 0.33 Gy and 0.38 ± 0.22 Gy in males and females, respectively; maximum annual dose was 0.67 ± 0.46 Gy and 0.55 ± 0.34 Gy in males and females, respectively. The CRS frequency in the Mayak PA worker cohort significantly increased with the cumulative and mean annual RBM absorbed dose of external exposure to gamma rays. In the meantime, the CRS frequency was not associated either with a dose of external neutron exposure or with a dose of internal exposure to alpha particles from incorporated plutonium.  Conclusion: The established CRS registry providing complete high quality demographical, medical and dosimetry information, together with available biological specimens, in future will allow: the updating of dose–response and dose–time–response relationships; the estimation of latent periods, risks and dose thresholds and associated uncertainties for CRS development; certain tissue reactions in lymphoid and haematopoietic tissues; and a better understanding of their development patterns and mechanisms, taking into account non-radiation factors.

Electrons generated from machine sources operated at or below an energy level of 10 MeV The eV (electronvolt) is the unit of energy used to measure and describe the energy of electrons and of other types of radiation. The energy of 1 eV is equivalent to the kinetic energy acquired by an electron on being accelerated through a potential difference of 1 V. The eV is a very small unit of energy. It is therefore more common to speak of keV (kiloelectronvolt = 1000 eV) or MeV (megaelectronvolt = 1 million eV). To convert eV to units of energy one can use the conversion 1 MeV = 1.602 X 10“ J (joule). Gamma rays and x-rays are part of the electromagnetic spectrum (Fig. 1), which reaches from the low-energy, long-wavelength radiowaves to the high-energy, short-wavelength cosmic rays. Radiowaves, infrared (IR) waves, and visible light are nonionizing radiations. Ultraviolet (UV) light can ionize only certain types of molecule under specific conditions and is generally not consid­ ered as ionizing radiation. X-rays and gamma rays are identical in their physical properties and in their effect on matter; they differ in their origin. X-rays are produced by machines and exhibit a wide continuous spectrum of radiation, whereas gamma rays come from radioactive isotopes (radionuclides) in a discon­ tinuous spectrum of radiation intensities. When ionizing radiation penetrates into a medium (e.g., the irradiated food) all or part of the radiation energy is absorbed by the medium. This is called the absorbed dose. The unit in which the absorbed dose is measured is the gray (Gy); it is equal to the absorption of 1 J (joule)/kg. One kGy (kilogray) = 1000 Gy. Formerly the dose unit rad was used. It was defined as 100 erg/g. The conversion of old to new units is based on the relationship 1000 rad = 1 Gy, or 1 krad = 10 Gy, or 1 Mrad = 10 kGy. The dose accumulated per unit of time is called the dose rate. Gamma ray sources provide a relatively low dose rate (typically 100-10,000 Gy/h, whereas

1995 ◽  
pp. 28-28
Keyword(s):  
Ionizing Radiation ◽  
Dose Rate ◽  
Gamma Rays ◽  
Gamma Ray ◽  
Uv Light ◽  
Absorbed Dose ◽  
Radiation Energy ◽  
Radioactive Isotopes ◽  
X Rays ◽  
Small Unit

scholarly journals Interaction of Low Doses of Ionizing Radiation, Potassium Dichromate and Cadmium Chloride in Artemia franciscana Biotest

2007 ◽  
Vol 76 (1) ◽  
pp. 35-40 ◽  
Author(s):  
K. Beňová ◽  
P. Dvořák ◽  
M. Falis ◽  
Z. Sklenář
Keyword(s):  
Ionizing Radiation ◽  
Gamma Radiation ◽  
Gamma Rays ◽  
Cadmium Chloride ◽  
Potassium Dichromate ◽  
Artemia Franciscana ◽  
Low Doses

The influence of cadmium chloride (at concentrations of 100 and 200 mg l-1) and potassium dichromate (at a concentration of 50 mg l-1) along with the effect of gamma radiation 60Co (at a dose of 10 and 50 Gy) on lethality to Artemia franciscana was investigated. Four different interactions were studied, namely, those of potassium dichromate and gamma radiation, cadmium chloride and gamma radiation, and combinations of potassium dichromate and cadmium chloride in interaction with gamma radiation. A significant (α = 0.05) decrease was observed in lethality due to exposure to radiation (10 Gy) in comparison with action of only potassium dichromate and cadmium chloride or their combination without exposure to gamma rays. These results support the theory of hormesis.

scholarly journals An Overview of Radiological Hazards Related to Geological External Gamma Radiation in Outdoor Environments

Proceedings ◽  
2018 ◽  
Vol 2 (10) ◽  
pp. 562
Author(s):  
Carlos Alves ◽  
Jorge Sanjurjo-Sánchez
Keyword(s):  
Gamma Radiation ◽  
Effective Dose ◽  
Dose Rate ◽  
Gamma Rays ◽  
Absorbed Dose ◽  
Absorbed Dose Rate ◽  
Radiological Hazards ◽  
Gamma Index ◽  
Outdoor Environments ◽  
Yearly Effective Dose

Rocks and soils are an important source of external gamma radiation due to their content in U, Th, and K. The dose rate derived from the emission of gamma-rays of radioisotopes can be directly measured or assessed from their content. In the present study, values of outdoor gamma radiation absorbed dose rate are analyzed to explore the implications of levels related to those values in terms of the exposure time necessary for attaining a certain yearly effective dose. We propose simple relations with the absorbed dose rate and with the gamma index of materials.

scholarly journals A gamma radiation exposure risk assessment using Monte Carlo simulation and an adult anthropomorphic phantom

2021 ◽  
Vol 234 ◽  
pp. 00060
Author(s):  
Youssef El-Ouardi ◽  
Adil Aknouch ◽  
Ahmed Dadouch ◽  
Mohammed Mouhib ◽  
Mounir Benmessaoud
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Ionizing Radiation ◽  
Gamma Radiation ◽  
Exposure Time ◽  
Human Life ◽  
Absorbed Dose ◽  
Dose Calculations ◽  
Anthropomorphic Phantom ◽  
Source Distance

The human body is vulnerable to exposure to ionizing radiation permanently. These radiations can be of natural origin such as soil and space, or of artificial and medical origins etc. Despite the great benefits that come from the applications of ionizing radiation in human life can turn at any time into threats to the life of the population once there is serious exposure to ionizing radiation. The aim of this work is to assess the risks of exposure by gamma radiation using the Monte Carlo simulation and an anthropomorphic phantom. This study is carried out on gamma rays received from the cobalt-60 irradiator of the National Institute of Agronomic Research (NIAR) Tangier / Morocco. With the code Geant4 we calculate the absorbed dose by the whole phantom body placed in front of the gamma irradiator inside the NIAR ionization cell. Dose calculations are made as a function of three parameters: phantom-irradiator distance, exposure time and as a function of gamma irradiator activity. The results clearly show that the dose absorbed and thus the danger of irradiation decreases by increasing the phantom-source distance, and by reducing the exposure time and the activity of the cobalt-60 source.

SKIN MELANOMA INCIDENCE IN WORKERS OCUPATIONALLY EXPOSED TO IONIZING RADIATION OVER A PROLONGED PERIOD

2019 ◽  
Vol 65 (3) ◽  
pp. 441-446
Author(s):  
Valentina Rybkina ◽  
Tamara Azizova ◽  
Yevgeniya Grigoreva
Keyword(s):  
Ionizing Radiation ◽  
Gamma Rays ◽  
Disease Risk ◽  
Incidence Rates ◽  
Study Cohort ◽  
Calendar Period ◽  
Skin Melanoma ◽  
Melanoma Incidence ◽  
Occupationally Exposed

Purpose of the study. The study is aimed to investigate skin melanoma incidence in workers occupationally exposed to radiation over a prolonged period. Materials and methods. Skin melanoma incidence was studied in a cohort of workers first employed at nuclear facility Mayak Production Association (PA) between 1948 and 1982 who had been followed up till 31.12.2013 (22,377 individuals). Mean cumulative doses from external gamma-rays over the whole follow-up period were 0.54±0.001 Sv in males and 0.44±0.002 Sv in females. Incident rates for skin melanoma were analyzed by sex, attained age, calendar period of diagnostics and radiation dose using worldwide standard and the direct standardization technique. Results. 60 skin melanoma cases (37 in males and 23 in females) were registered in the study cohort over the whole follow-up period. The standardized skin melanoma incident rate was 8.51±1.46 in males and 8.78±2.27 in females per 100000 workers revealing statistically higher rates compared to corresponding rates for general populations of the Russian Federation, Urals Federal District and Chelyabinsk region. Skin melanoma incidence was significantly increased in the period of 1994 - 2013 as compared to the period of 1974 - 1993. Skin melanoma incidence excess in females was greater than that for males. Skin melanoma incidence increment in females was mostly driven by modifications of disease occurrence risk while in males it was driven by a combined effect of age pattern modifications in the study cohort and increase of disease risk. Conclusions. Skin melanoma incidence rates in the cohort of workers occupationally exposed to ionizing radiation over a prolonged period were associated with sex and attained age workers and the calendar period of diagnostics. No significant association of skin melanoma incidence with dose from external gamma-rays was observed. A significantly increasing trend was observed for skin melanoma incidence by the end of the follow-up in both males and females.

Effect of ionizing radiation on the kinetics of hydrogenation on the Ni-MgO mixed catalyst

1982 ◽  
Vol 47 (7) ◽  
pp. 1780-1786 ◽  
Author(s):  
Rostislav Kudláček ◽  
Jan Lokoč
Keyword(s):  
Experimental Data ◽  
Activation Energy ◽  
Liquid Phase ◽  
Ionizing Radiation ◽  
Oxide Catalyst ◽  
Absorbed Dose ◽  
Hydrogenation Rate ◽  
Solution Composition ◽  
Mixed Catalyst ◽  
Kinetics Of

The effect of gamma pre-irradiation of the mixed nickel-magnesium oxide catalyst on the kinetics of hydrogenation of maleic acid in the liquid phase has been studied. The changes of the hydrogenation rate are compared with the changes of the adsorbed amount of the acid and with the changes of the solution composition, activation energy, and absorbed dose of the ionizing radiation. From this comparison and from the interpretation of the experimental data it can be deduced that two types of centers can be distinguished on the surface of the catalyst under study, namely the sorption centres for the acid and hydrogen and the reaction centres.

scholarly journals Depth-Sensing Indentation as a Micro- and Nanomechanical Approach to Characterisation of Mechanical Properties of Soft, Biological, and Biomimetic Materials

Nanomaterials ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 15 ◽  
Author(s):  
Nikolay V. Perepelkin ◽  
Feodor M. Borodich ◽  
Alexander E. Kovalev ◽  
Stanislav N. Gorb
Keyword(s):  
Review Paper ◽  
Soft Materials ◽  
Data Fitting ◽  
Depth Sensing ◽  
Adhesive Properties ◽  
Distinctive Features ◽  
Experimental Part ◽  
Properties Of Materials ◽  
The Mathematical Model ◽  
Non Destructive

Classical methods of material testing become extremely complicated or impossible at micro-/nanoscale. At the same time, depth-sensing indentation (DSI) can be applied without much change at various length scales. However, interpretation of the DSI data needs to be done carefully, as length-scale dependent effects, such as adhesion, should be taken into account. This review paper is focused on different DSI approaches and factors that can lead to erroneous results, if conventional DSI methods are used for micro-/nanomechanical testing, or testing soft materials. We also review our recent advances in the development of a method that intrinsically takes adhesion effects in DSI into account: the Borodich–Galanov (BG) method, and its extended variant (eBG). The BG/eBG methods can be considered a framework made of the experimental part (DSI by means of spherical indenters), and the data processing part (data fitting based on the mathematical model of the experiment), with such distinctive features as intrinsic model-based account of adhesion, the ability to simultaneously estimate elastic and adhesive properties of materials, and non-destructive nature.

scholarly journals The Impact of Elongation on Change in Electrical Resistance of Electrically Conductive Yarns Woven into Fabric

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3390
Author(s):  
Željko Knezić ◽  
Željko Penava ◽  
Diana Šimić Penava ◽  
Dubravko Rogale
Keyword(s):  
Mathematical Model ◽  
Electrical Resistance ◽  
Electrically Conductive ◽  
Textile Materials ◽  
Measurement Results ◽  
Conductive Yarns ◽  
Yarn Count ◽  
As Relationship ◽  
The Impact ◽  
The Mathematical Model

Electrically conductive yarns (ECYs) are gaining increasing applications in woven textile materials, especially in woven sensors suitable for incorporation into clothing. In this paper, the effect of the yarn count of ECYs woven into fabric on values of electrical resistance is analyzed. We also observe how the direction of action of elongation force, considering the position of the woven ECY, effects the change in the electrical resistance of the electrically conductive fabric. The measurements were performed on nine different samples of fabric in a plain weave, into which were woven ECYs with three different yarn counts and three different directions. Relationship curves between values of elongation forces and elongation to break, as well as relationship curves between values of electrical resistance of fabrics with ECYs and elongation, were experimentally obtained. An analytical mathematical model was also established, and analysis was conducted, which determined the models of function of connection between force and elongation, and between electrical resistance and elongation. The connection between the measurement results and the mathematical model was confirmed. The connection between the mathematical model and the experimental results enables the design of ECY properties in woven materials, especially textile force and elongation sensors.

Sign in / Sign up

Export Citation Format

Share Document