Effect of Processing and Radiation Exposure on the Structure and Properties of Polypropylene

2019 ◽  
Vol 822 ◽  
pp. 355-361
Author(s):  
M.S. Lisanevich ◽  
Rezeda Yu. Galimzyanova ◽  
Elvina P. Rakhmatullina ◽  
Yu.N. Khakimullin ◽  
Ildar N. Musin ◽  
...  
Keyword(s):  
Ionizing Radiation ◽  
Radiation Exposure ◽  
Initial Temperature ◽  
Absorbed Dose ◽  
Radiation Sterilization ◽  
Processing Conditions ◽  
Oxidation Induction Time ◽  
Polymer Properties ◽  
Oxidative Breakdown ◽  
Negative Effect

While producing polymers as well as during their processing, a certain amount of stabilizers is introduced into the product, which should ensure polymer properties saving during processing and those of polymer products during storage and operation. However, in cases where medical products based on polypropylene are subjected to radiation sterilization, there are not enough stabilizers in it to save their characteristics during operation. In this regard, we made an assessment of the influence of processing conditions on the properties of polypropylene with a different set of stabilizers in the manufacture of products based on it, in order to assess the degree of influence of each technological operation, including the effects of ionizing radiation during sterilization. Processing and radiation exposure are shown to affect the properties of polypropylene. Nevertheless, the effect of ionizing radiation with an absorbed dose of 40-60 kGy exceeds the negative effect of thermo-oxidative breakdown greatly during the extrusion of PP. Polypropylene containing organophosphorus stabilizers (brand PP 1562R) is more susceptible to breakdown. This is indicated by low values of oxidation induction time, breakdown initial temperature, as well as high values of MFI after exposure to electron radiation. PP brand PP H350FF/1 whose stabilizing complex contains phenol-phosphite antioxidants is more resistant to breakdown during processing and sterilization. For both brands under study, it is apparently necessary to increase the content of stabilizing additives in order to save the properties at the level of the original unexposed material.

The Effect of Radiation Sterilization on the Stress-Strain Properties of Non-Woven Materials -Based on Polypropylene

2020 ◽  
Vol 992 ◽  
pp. 403-408
Author(s):  
Elvina R. Rakhmatullina ◽  
M.S. Lisanevich ◽  
Rezeda Yu. Galimzyanova ◽  
Yu.N. Khakimullin
Keyword(s):  
Ionizing Radiation ◽  
Absorbed Dose ◽  
Breaking Load ◽  
Radiation Sterilization ◽  
Stress Strain ◽  
Cross Direction ◽  
Absorbed Doses ◽  
Single Use ◽  
The Cross ◽  
The Web

Non-woven materials are widely used for the manufacture of disposable medical clothing and underwear. Radiation is widely used to sterilize single-use medical devices. The paper analyzes the effect of ionizing radiation at absorbed doses of 0-60 kGy on the stress-strain properties of medical non-woven spanmelt material based on polypropylene obtained by blow-molding technology. It has been established that ionizing radiation significantly reduces the breaking load and elongation in the machine and cross directions of the web. For this type of material, the most critical is the decrease in strength in the cross direction of the web, primarily because the level of strength in the cross direction of spanmelt materials is generally low. Sterilization by ionizing radiation further reduces strength and leads to the fact that non-woven materials irradiated with an absorbed dose of 50-60 kGy are close to unacceptable values in accordance with the requirements of EN 13975-2011.

Impact of radiation induced crystallization on programmable metallization cell electrical characteristics and reliability

2019 ◽  
Vol 213 ◽  
pp. 53-66
Author(s):  
Yago Gonzalez-Velo ◽  
Arshey Patadia ◽  
Hugh J. Barnaby ◽  
Michael N. Kozicki
Keyword(s):  
Ionizing Radiation ◽  
Radiation Exposure ◽  
Absorbed Dose ◽  
Electrical Characteristics ◽  
Programmable Metallization Cell ◽  
Radiation Induced ◽  
Programmable Metallization Cells ◽  
Ionizing Radiation Exposure ◽  
Metallization Cells ◽  
Induced Crystallization

Chalcogenide-based, programmable metallization cells (PMC) cells have been characterized after exposure to increasing levels of absorbed dose (i.e., ionizing radiation exposure).

scholarly journals Effects of radiation sterilization on the properties of nonwoven medical devices

2020 ◽  
Vol 64 (11) ◽  
pp. 127-134
Author(s):  
Maria S. Lisanevich ◽  
◽  
Reseda Yu. Galimzyanova ◽  
Ildar N. Musin ◽  
◽  
...  
Keyword(s):  
Ionizing Radiation ◽  
Medical Devices ◽  
Human Life ◽  
Low Cost ◽  
Absorbed Dose ◽  
Nonwoven Material ◽  
Radiation Sterilization ◽  
Nonwoven Materials ◽  
Wide Range ◽  
Materials Used

Currently, there is a tendency for a significant increase in production and expansion of areas of application of nonwoven materials (NM), which are used in almost all areas of human life. Such properties of NMs as hydrophilicity or hydrophobicity, air permeability, good barrier and strength indicators at a relative low cost allow them to be effectively used for medical purposes. Nonwovens for medical use (NMMN) are considered. The most important stage in the final processing of medical devices made of NM is radiation sterilization. The influence of the absorbed dose and the type of ionizing radiation on the properties of NMMN of various designs: obtained by spunlace technology, by spunbond-meltblown-spunbond technology, and laminated nonwoven material has been studied. As a result of the conducted research, it was recommended: to sterilize NM with an electron beam, to control the consumer properties of medical devices from NM to check the quality of products after sterilization by assessing the change in the strength index with elongation, additionally to assess for laminated NM – water resistance, spunlace – absorption. In the production of nonwoven materials, various polymers are used, which have correspondingly different resistance to radiation sterilization. Some materials, for example, based on polypropylene, degrade when exposed to radiation, and the level of technical characteristics of the material is significantly reduced. It is also possible for autooxidative reactions initiated by radiation to occur in polymers, which can continue for a long time after irradiation of articles. To use these materials in radiation sterilized medical devices, it is necessary to have an understanding of the effect of ionizing radiation in a wide range of sterilizing doses on the materials used in these devices.

The problem of ionizing radiation exposure of the radiologists in the opinion of students of Medical Faculties of the Medical University of Lublin

2008 ◽  
Vol 63 (1) ◽  
pp. 230-233
Author(s):  
Elżbieta Czekajska-Chehab ◽  
Piotr Przybylski ◽  
Marcin Pankowicz ◽  
Maria Korzec ◽  
Andrzej Drop
Keyword(s):  
Ionizing Radiation ◽  
Radiation Exposure ◽  
Medical Faculties ◽  
Medical University ◽  
Ionizing Radiation Exposure

Requesting physicians’ knowledge of X-radiation exposure from computed tomography scan examinations: A case study of two Nigerian tertiary hospitals

2020 ◽  
Vol 3 ◽  
pp. 36-39
Author(s):  
Samson O. Paulinus ◽  
Benjamin E. Udoh ◽  
Bassey E. Archibong ◽  
Akpama E. Egong ◽  
Akwa E. Erim ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Ionizing Radiation ◽  
Ct Scan ◽  
Radiation Exposure ◽  
Work Experience ◽  
Radiation Risk ◽  
Radiological Protection ◽  
X Ray ◽  
Tertiary Hospitals ◽  
Medical Exposure

Objective: Physicians who often request for computed tomography (CT) scan examinations are expected to have sound knowledge of radiation exposure (risks) to patients in line with the basic radiation protection principles according to the International Commission on Radiological Protection (ICRP), the Protection of Persons Undergoing Medical Exposure or Treatment (POPUMET), and the Ionizing Radiation (Medical Exposure) Regulations (IR(ME)R). The aim is to assess the level of requesting physicians’ knowledge of ionizing radiation from CT scan examinations in two Nigerian tertiary hospitals. Materials and Methods: An 18-item-based questionnaire was distributed to 141 practicing medical doctors, excluding radiologists with work experience from 0 to >16 years in two major teaching hospitals in Nigeria with a return rate of 69%, using a voluntary sampling technique. Results: The results showed that 25% of the respondents identified CT thorax, abdomen, and pelvis examination as having the highest radiation risk, while 22% said that it was a conventional chest X-ray. Furthermore, 14% concluded that CT head had the highest risk while 9% gave their answer to be conventional abdominal X-ray. In addition, 17% inferred that magnetic resonance imaging had the highest radiation risk while 11% had no idea. Furthermore, 25.5% of the respondents have had training on ionizing radiation from CT scan examinations while 74.5% had no training. Majority (90%) of the respondents were not aware of the ICRP guidelines for requesting investigations with very little (<3%) or no knowledge (0%) on the POPUMET and the IR(ME)R respectively. Conclusion: There is low level of knowledge of ionizing radiation from CT scan examinations among requesting physicians in the study locations.

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 A systematic review on the effect of low-dose radiation on hearing

2021 ◽  
Author(s):  
Srikanth Nayak ◽  
Arivudai Nambi ◽  
Sathish Kumar ◽  
P Hariprakash ◽  
Pradeep Yuvaraj ◽  
...  
Keyword(s):  
Systematic Review ◽  
Ionizing Radiation ◽  
Radiation Exposure ◽  
Low Dose ◽  
Behavioral Symptoms ◽  
National Council ◽  
Low Dose Radiation ◽  
Cochlear Function ◽  
High Frequencies ◽  
Dose Radiation

AbstractNumerous studies have documented the adverse effects of high-dose radiation on hearing in patients. On the other hand, radiographers are exposed to a low dose of ionizing radiation, and the effect of a low dose of radiation on hearing is quite abstruse. Therefore, the present systematic review aimed to elucidate the effect of low-dose ionizing radiation on hearing. Two authors independently carried out a comprehensive data search in three electronic databases, including PUBMED/MEDLINE, CINAHL, and SCOPUS. Eligible articles were independently assessed for quality by two authors. Cochrane Risk of Bias tool was used assess quality of the included studies. Two articles met the low-dose radiation exposure criteria given by Atomic Energy Regulatory Board (AERB) and National Council on Radiation Protection (NCRP) guidelines. Both studies observed the behavioral symptoms, pure-tone hearing sensitivity at the standard, extended high frequencies, and the middle ear functioning in low-dose radiation-exposed individuals and compared with age and gender-matched controls. One study assessed the cochlear function using transient-evoked otoacoustic emissions (TEOAE). Both studies reported that behavioral symptoms of auditory dysfunction and hearing thresholds at extended high frequencies were higher in radiation-exposed individuals than in the controls. The current systematic review concludes that the low-dose ionizing radiation may affect the hearing adversely. Nevertheless, further studies with robust research design are required to explicate the cause and effect relationship between the occupational low-dose ionizing radiation exposure and hearing.

scholarly journals Effects of resveratrol against scattered radiation-induced testicular damage in rats

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Tarik Emre Sener ◽  
Beste Melek Atasoy ◽  
Ozge Cevik ◽  
Ozlem Tugce Cilingir Kaya ◽  
Sule Cetinel ◽  
...  
Keyword(s):  
Ionizing Radiation ◽  
Radiation Exposure ◽  
Scattered Radiation ◽  
Caspase 3 ◽  
Sirtuin 1 ◽  
Protective Agent ◽  
Testicular Damage ◽  
Testosterone Levels ◽  
Protein Expressions ◽  
Ionizing Radiation Exposure

AbstractObjectivesTo investigate the possible protective effects of resveratrol against oxidative testicular damage due to scattered radiation during pelvic ionizing radiation exposure in rats.MethodsRats were divided into 5 groups; control, radiation, and radiation + resveratrol therapy in early and late periods. Under anesthesia, 20 Gy ionizing radiation was applied to prostatic region. Resveratrol was administered (10 mg/kg/day) orally before ionizing radiation exposure. Animals were decapitated at the end of 1st and 10th weeks. Biochemical markers of oxidative stress; caspase-3 and sirtuin-1 protein expressions; testosterone levels were evaluated, histological examinations were performed.ResultsSignificant increases in malondialdehyde, 8-hydroxy-deoxyguanosine levels, myeloperoxidase, and caspase-3 activities were observed after ionizing radiation exposure, also superoxide dismutase and glutathione activities were significantly decreased. Radiotherapy increased caspase-3 and decreased sirtuin-1 protein expressions. Resveratrol treatment significantly reversed these parameters and also reversed the decrease in testosterone levels back to control levels in late period.ConclusionResveratrol showed antioxidant and sirtuin-activating properties against oxidative damage caused by scattered radiation to testis and provided hormonal protection. These results suggest that resveratrol may be an alternative protective agent on testicular tissues against the effects of scattered pelvic radiation.

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