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1 – 10 of 484S. O'Keeffe, C. Fitzpatrick, E. Lewis and A.I. Al‐Shamma'a
The purpose of this paper is to provide a detailed review of radiation dosimetry techniques based on optical fibre dosimeters. It presents a comprehensive bibliography of the…
Abstract
Purpose
The purpose of this paper is to provide a detailed review of radiation dosimetry techniques based on optical fibre dosimeters. It presents a comprehensive bibliography of the current research activities in the area.
Design/methodology/approach
A range of published work on optical fibre radiation dosimeters are presented, with the merits and limitations discussed. Each radiation dosimetry technique is discussed in turn, providing examples of dosimeters using such techniques reviewed. The main focus is on gamma radiation although other radiation dosimeters are considered.
Findings
This paper provides information on the wide range of research activity into radiation dosimeters. The dose ranges of these dosimeters are presented, along with the advantages and disadvantages of different dosimetry techniques.
Originality/value
A comprehensive review of published research in the area of solid radiation dosimetry is presented in this paper. It provides an individual with a review of the various techniques used and most recent research in that field.
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Keywords
This paper aims to describe the effects of radiation on certain classes of sensors and electronic devices and discusses the sensors used in high radiation environments.
Abstract
Purpose
This paper aims to describe the effects of radiation on certain classes of sensors and electronic devices and discusses the sensors used in high radiation environments.
Design/methodology/approach
Following an introduction, this paper firstly discusses the effects of radiation on semiconductors. It then considers the sensor technologies employed in high radiation applications and examines the impact of radiation on MEMS devices. Finally, it describes a radiation‐tolerant imaging sensor technology.
Findings
Ionising and non‐ionising radiation in terrestrial and space environments can exert a detrimental effect on semiconductor devices and has led to the development of a range of radiation hardening technologies. Most of the sensors used in nuclear power plants utilise long‐established and well‐characterised technologies which are inherently radiation‐tolerant but silicon MEMS devices are more prone to damage and a range of failure mechanisms have been identified. Most conventional image sensors are susceptible to radiation damage but a radiation‐hard technology termed the charge‐injection device has been developed which overcomes these problems.
Originality/value
This paper provides details of the sensor technologies used in high radiation applications.
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Sunthorn Chaitat, Nattapon Chantarapanich and Sujin Wanchat
This paper aims to investigate effect of infill density, fabricated built orientation and dose of gamma radiation to mechanical tensile and compressive properties of polylactic…
Abstract
Purpose
This paper aims to investigate effect of infill density, fabricated built orientation and dose of gamma radiation to mechanical tensile and compressive properties of polylactic acid (PLA) part fabricated by fused deposit modelling (FDM) technique for medical applications.
Design/methodology/approach
PLA specimens for tensile and compressive tests were fabricated using FDM machine. The specimens geometry and test method were referred to ASTM D638 and ASTM D695, respectively. Three orientations under consideration were flat, edge and upright, whereas the infill density ranged from 0 to 100%. The gamma radiation dose used to expose to specimens was 25 kGy. The collected data included stress and strain, which was used to find mechanical properties, i.e. yield strength, ultimate tensile strength (UTS), fracture strength, elongation at yield, elongation at UTS and elongation at break. The t-test was used to access the difference in mechanical properties.
Findings
Compressive mechanical properties is greater than tensile mechanical properties. Increasing number of layer parallel to loading direction and infill density, it enhances the material property. Upright presents the lowest mechanical property in tensile test, but greatest in compressive test. Upright orientation should not be used for part subjecting to tensile load. FDM is more proper for part subjecting to compressive load. FDM part requires undergoing gamma ray for sterilisation, the infill density no less than 70 and 60% should be selected for part subjecting to tensile and compressive load, respectively.
Originality/value
This study investigated all mechanical properties in both tension and compression as well as exposure to gamma radiation. The results can be applied in selection of FDM parameters for medical device manufacturing.
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The effects of γ‐radiation on both the optical and the electrical properties of Tellurium dioxide (TeO2) thin films were investigated. TeO2 thin films were fabricated using…
Abstract
The effects of γ‐radiation on both the optical and the electrical properties of Tellurium dioxide (TeO2) thin films were investigated. TeO2 thin films were fabricated using thermal vacuum deposition method. Samples were exposed to a 60Co γ‐radiation source with a dose rate of 6 Gy/min. Absorption spectra for TeO2 thin films were recorded and values of the optical band gap for as‐deposited and γ‐irradiated films were calculated. Sets of measurements based on Hall effect were carried out. From the data received the dependences of sheet resistance, density of charge carriers, mobility and Hall coefficient with radiation dose were determined.
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The object of this paper is to describe English Electric work and experience in the development and application of computer‐produced indexes.
The purpose of this paper is to provide a review of the industrial sensing applications of electromagnetic radiation (EMR) with an emphasis on wavelengths other than visible…
Abstract
Purpose
The purpose of this paper is to provide a review of the industrial sensing applications of electromagnetic radiation (EMR) with an emphasis on wavelengths other than visible light. The paper is in two parts. This, the first, considers radiations with shorter wavelengths than visible light, i.e. γ radiation, X‐rays and ultra‐violet (UV).
Design/methodology/approach
The paper discusses the sensing applications of short wavelength EMR through reference to the techniques employed, products and their uses.
Findings
The paper shows that γ radiation, X‐rays and UV radiation are used in a wide range of industrial sensors for the measurement of physical variables, chemical compounds and gases. The phenomena employed include absorption, backscatter, photoionisation, fluorescence and reflection. Applications are extremely varied and embrace a diversity of industries.
Originality/value
The paper provides a detailed, technical review of the sensing uses of short wavelength EMR.
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J. Gisbert, M. Bonet, P. Díaz, I. Montava and P. Monllor
Electron beam is a way of radiation that can induce different reactions on polymers. The purpose of this work is to analyze the effect that the electron beam can produce on…
Abstract
Purpose
Electron beam is a way of radiation that can induce different reactions on polymers. The purpose of this work is to analyze the effect that the electron beam can produce on polyester fabrics.
Design/methodology/approach
Poly(ethylene terephthalate) (PET) fibres were treated at 0, 50, 100, 150, and 200 KGy. Later on surface modification was analyzed by Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). Colorimetric and thermal measurements were studied too, as well as traction resistance.
Findings
Traction resistance showed no significant variations. As a result the authors could observe some changes in fabric witnesses and cristallinity increase, but no changes in traction resistance were observed. Moreover, when surface was studied, roughness was increased as oligomers moved towards fibre surface because of radiation dose.
Originality/value
The authors could appreciate roughness increased with radiation dose as well as yellowness and crystallinity.
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Kati Kokko, Hanna Harjunpää, Pekka Heino and Minna Kellomäki
The purpose of this paper is to investigate the influence of composite coating structure on the reliability of adhesive flip chip joints. The need for conformal coating is…
Abstract
Purpose
The purpose of this paper is to investigate the influence of composite coating structure on the reliability of adhesive flip chip joints. The need for conformal coating is considered, especially for medical applications, and medical sterilization is also considered.
Design/methodology/approach
Two test lots were assembled and one of them was sterilized using gamma sterilization. Both test lots were coated first with epoxy and then with Parylene C, resulting in a composite coating structure. The reliability was studied using a constant humidity test and the failure analysis was performed with cross‐sections and scanning electron microscopy analysis. These results were compared to earlier research results on conformal coatings.
Findings
The reliability of both test lots proved to be good. The composite coating structure shields the joints from humidity and improves the reliability compared to non‐coated test samples. When the conformal coating was compared to the pure Parylene C coated test lot, the reliability was almost the same. This leads to the conclusion that the epoxy layer in the composite coating structure has no value when long‐term reliability is considered. Gamma sterilization does not greatly affect reliability. The epoxy coating under the Parylene C layer cracked during reliability testing.
Originality/value
The paper shows the influence of composite coating structure on the reliability of adhesive flip chip joints, particularly important in medical applications.
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Flora Philippe, Maria José Abreu, Laurence Schacher, Dominique C. Adolphe and Maria Elisabete Cabeço Silva
More and more disposable goods are available in surgical rooms. Rules and standards have been proposed in order to prevent infection from patient to surgical team and vice versa…
Abstract
More and more disposable goods are available in surgical rooms. Rules and standards have been proposed in order to prevent infection from patient to surgical team and vice versa. A proposed mandatory European standard prEn 13795 “Surgical drapes, gowns and clear air suits used as medical devices, for patients, clinical staff and equipment”, is being developed by the Committee of European Normalisation and specifies the basic performance requirements and test methods for single‐use and reusable materials after sterilisation process. Therefore, the performances of the surgical gowns demand a balance between barrier and comfort properties. In comfort evaluation, tactile feeling is one of the most primary and important aspects with regard to the grading of the products. Therefore, the influence of the sterilisation process on the tactile perception is important to be evaluated. Subsequently, the final aim of this paper is to contribute to the knowledge of influence of sterilisation treatment on the tactile perception.
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The sale of irradiated food is currently prohibited in the UnitedKingdom under The Food (Control of Irradiation) Regulations 1967. Thissituation seems likely to change given first…
Abstract
The sale of irradiated food is currently prohibited in the United Kingdom under The Food (Control of Irradiation) Regulations 1967. This situation seems likely to change given first the recommendation by a number of expert committees that irradiated food is safe and wholesome, and second the current need to complete the EEC internal market for food in a situation where several member states already permit the sale of irradiated produce. The controversy surrounding the irradiated food issue is, in part, politically inspired. In particular, the issue has served to articulate concern over the lack of consumer representation in food policy decision making forums, both at the UK and European level. Consumer resistance to the technology for the most part, however, reflects an exaggeration of the perceived risks associated with buying and consuming irradiated foods, together with a negative evaluation of the benefits that the process offers. Consumers perceive these benefits as accruing mainly to the food industry. The difficulty that consumers have in believing that they, too, can share in these benefits stems from the way in which consumers make sense of the knowledge that they possess about food. It is this problem which needs to be addressed.
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