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11 – 20 of 514The 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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Wan Yusmawati Wan Yusoff, Norliza Ismail, Nur Farisa Nadia Mohmad Lehan, Azuraida Amat, Ku Zarina Ku Ahmad, Azman Jalar and Irman Abdul Rahman
This paper aims to investigate the effect of different doses of gamma radiation on the micromechanical response (hardness properties and creep behaviour) of 96.5Sn-3.0Ag-0.5Cu…
Abstract
Purpose
This paper aims to investigate the effect of different doses of gamma radiation on the micromechanical response (hardness properties and creep behaviour) of 96.5Sn-3.0Ag-0.5Cu (SAC305) solder alloys.
Design/methodology/approach
SAC305 solder pastes deposited on printed circuit boards (PCBs) were subjected to a reflow soldering process to form soldered samples. The soldered samples were irradiated with a gamma source at different doses (5–50 Gy). Nanoindentation testing was used to determine the hardness properties and creep behaviour after gamma irradiation.
Findings
The results showed that the hardness of SAC305 solder alloys gradually increased up to 15 Gy and then gradually decreased to 50 Gy of gamma irradiation. The highest hardness value (0.37 GPa) was observed on SAC305 solder alloys exposed to 15 Gy irradiation. Hardening of SAC305 solder alloy was suggested to be due to the high defect density induced by the gamma irradiation. Meanwhile, exposure to 50 Gy irradiation resulted in the lowest hardness value, 0.13 GPa. The softening behaviour of SAC305 solder alloy was probably due to the evolution of defect size in the solder joint. In addition, the creep behaviour of the SAC305 solder alloys changed significantly with different gamma irradiation doses. The creep rates were higher at a dose of 10 Gy up to a dose of 50 Gy. Gamma irradiation caused the SAC305 solder alloy to become more ductile compared to the non-irradiated alloy. The stress exponent also showed different deformation mechanisms with varying gamma doses.
Originality/value
Research into the micromechanical properties of solder alloys subjected to gamma irradiation has rarely been reported, especially for Sn-Ag-Cu lead-free solder. Thus, this research provides a fundamental understanding of the micromechanical response (hardness and creep behaviour) of solder, especially lead-free solder alloy, to gamma irradiation.
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Sameh Mohamed Gafar and Nehad Magdy Abdel-Kader
The purpose of this paper is to study the effect of gamma-rays on murexide (Mx) dye and its possible use as radiation dosimeters in two different dosimetry systems. The first…
Abstract
Purpose
The purpose of this paper is to study the effect of gamma-rays on murexide (Mx) dye and its possible use as radiation dosimeters in two different dosimetry systems. The first system depends on the Mx dye as a liquid dosimeter. The second dosimetry system depends also on the same dye but as in a gel form, which is more sensitive to gamma-rays.
Design/methodology/approach
The prepared Mx (solutions/gels) have a considerable two peaks at 324 and 521 nm that upon irradiation, the intensity of these peaks decreases with the increasing radiation dose.
Findings
The gamma-ray absorbed dose for these dosimeters was found to be up to 2 kGy for the solution samples and 40 Gy for the gels. Radiation chemical yield, dose response function, radiation sensitivity and before and after-irradiation stability under various conditions were discussed and studied.
Practical implications
It is expected that the radiolysis of the Mx dye can be used as radiation dosimeters in two different dosimetry systems; liquid and gel dosimeters. This can be applied in a wide range of gamma radiation practical industrial applications in water treatment, food irradiation dosimeters, radiotherapy and fresh food irradiation and seed production.
Originality/value
Both of the prepared Mx dyes, either as solutions or gel samples, can be facilely prepared from commercially, cheap, safe, available chemicals and suitable for useful applied Mx solutions and gels radiation dosimeters.
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The purpose of this paper is to provide a review of recent developments in electromagnetic radiation (EMR) sensing.
Abstract
Purpose
The purpose of this paper is to provide a review of recent developments in electromagnetic radiation (EMR) sensing.
Design/methodology/approach
Following a short introduction, this paper discusses a selection of recent research and development activities concerning the sensing of gamma radiation, X‐rays and ultraviolet (UV) radiation.
Findings
This shows that novel sensors are being developed for all of these classes of EMR. Improved gamma sensors are attracting strong interest in the USA, reflecting concerns regarding nuclear security. Novel X‐ray and UV sensors are often being developed in response to new and emerging uses of these types of radiation.
Originality/value
This paper provides a technical review of recent research into sensors for detecting gamma radiation, X‐rays and UV radiation.
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Iram Batool, Ijaz Ahmad Bhatti, Shahid Adeel and Muhammad Abbas
The effect of gamma radiation on the dyeing of cotton with Reactive Blue 13 dye powder has been investigated. The cotton and dye powder are irradiated to absorb doses of 100, 200…
Abstract
The effect of gamma radiation on the dyeing of cotton with Reactive Blue 13 dye powder has been investigated. The cotton and dye powder are irradiated to absorb doses of 100, 200, 300, 400 and 500 Gy by using a Co-60 gamma irradiator. Dyeing is performed by using irradiated and un-irradiated cotton with irradiated and un-irradiated dye powder, in order to observe the effect of radiation treatment on the colour strength of the reactive dye on cotton. Different dyeing parameters such as temperature, time and p H are optimized using irradiated cotton and dye powder. The effect of gamma irradiation on the colour strength and Lab values has been observed through optimized conditions of dyeing. The colour strength and Lab values are obtained by spectra flash spectrophotometer (SF650). ISO standard methods are employed to study the effect of gamma radiation on the Colourfastness properties of fabric. It can be demonstrated that gamma irradiation not only improves the colour strength of the dye in irradiated cotton, but also enhances the Colourfastness properties.
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The purpose of this research paper is to study a comparison between two dosimetry systems, both of them based on basic violet dye (BV).
Abstract
Purpose
The purpose of this research paper is to study a comparison between two dosimetry systems, both of them based on basic violet dye (BV).
Design/methodology/approach
The first system depends on (BV) (incorporating polyvinyl alcohol) as a thin-film dosimeter. The second system also relies on (BV) as a solution dosimeter, which is more sensitive to gamma rays. The two prepared film/solutions have a considerable signal that decreases upon irradiation and the strength of the signal decreases with increasing radiation dose.
Findings
The gamma ray absorbed dose for these dosimeters was found to be up to 35 kGy for films and 1 kGy for the liquid phase. All dosimetric characteristics as radiation chemical yield, additive substance, dose-response function, radiation sensitivity, also before and after-irradiation stability under various conditions were considered.
Practical implications
It is expected the vital role of gamma radiation on this dye in its two forms or two media. This reveals their wide applications in the field of gamma irradiation processing.
Originality/value
These two dosimetry systems which depend upon the same dye are safe to handle, inexpensive, available raw materials and can be applied in various dosimetry applications as mentioned above.
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Md. Asadul Hoque, Md. Anwarul Kabir Bhuiya, Md. Saiduzzaman, Md. Ashadul Islam and Mubarak A. Khan
This paper aim to comparatively study of mechanical properties of gamma radiation treated raw and polyethylene glycol modified bleached jute reinforced polyester composite. The…
Abstract
Purpose
This paper aim to comparatively study of mechanical properties of gamma radiation treated raw and polyethylene glycol modified bleached jute reinforced polyester composite. The natural fiber-reinforced composite has been a wide area of research, and it is the preferred choice due to its superior physical and mechanical properties like low density, stiffness and light weight. Among several natural fibers, jute is one that has good potential as reinforcement in polymer composite. Jute fibers biodegradability, low cost and moderate mechanical properties make it as a preferable reinforcement material in the development of polymer matrix composites.
Design/methodology/approach
In the present work, raw jute fabrics-reinforced polyester composite (as RJPC) and polyethylene glycol (PEG)-modified bleached jute fabrics-reinforced polyester composite (as MBJPC) were fabricated by the heat-press molding technique at 120°C for 5 min at a pressure of 5 tons. Prior to the composite formulation, low lignin content bleached jute fabrics were chemically modified with PEG for the better compatibility of the fabrics with the polyester matrix and enhancing elongation properties. All the composites irradiated with different gamma radiation dose in the range of 2 to 14 kGy.
Findings
The irradiated composites showed highest improved of mechanical properties at the 10 kGy γ-radiation dose. However, the hard and sunlight-sensitive high lignin content γ-RJPC showed higher mechanical properties except elongation properties compared to that of low lignin content γ-MBJPC.
Originality/value
After the γ-ray irradiation, both the γ-RJPC and γ-MBJPC developed high degree of cross-linking among the polyester molecules and thereto fabrics with the consequence of significant changed of surface morphology as observed by atomic force microscopy.
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Khalil Arshak, Olga Korostynska and John Henry
Indium oxide (In2O3) and silicon oxide (SiO) mixtures in the form of thick films pn‐junctions were investigated for gamma radiation dosimetry purposes. Polymer pastes of In2O3 and…
Abstract
Indium oxide (In2O3) and silicon oxide (SiO) mixtures in the form of thick films pn‐junctions were investigated for gamma radiation dosimetry purposes. Polymer pastes of In2O3 and SiO mixtures in various proportions were made of 92 wt per cent of functional material and 8 wt per cent of PVB, while ethyleneglycolmonobutylether was used as a solvent. Raman spectroscopy and X‐ray diffraction (XRD) of the films readily endorse the formation of a mixed silicon oxide and indium oxide coating. All devices were exposed to a disc‐type 137Cs source with an activity of 370 kBq. The I‐V characteristics for the samples were measured after each exposure dose. Results show that the current is increased with the increase in radiation dose to a certain level, exceeding this level resulted in unstable dosimetric characteristics and device damage. The performance parameters of the devices, such as sensitivity to γ‐radiation exposure and working dose region, were found to be highly dependant on the composition of the materials used.
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Khalil Arshak and Olga Korostynska
Combination of a number of sensors with different response parameters into sensor arrays would enhance the overall performance of the radiation detection system. This paper…
Abstract
Purpose
Combination of a number of sensors with different response parameters into sensor arrays would enhance the overall performance of the radiation detection system. This paper presents a conceptual approach to the development of sensor arrays system with instantaneous dose and dose rate readout. A dynamic selection of multiple sensors with various sensitivity and accuracy range is implemented by applying pattern recognition (PR) analysis, which maximizes measurement accuracy. A number of relevant PR methods are discussed.
Design/methodology/approach
Thick films based on NiO, ZnO, In2O3, CeO2, TiO2, CuO and CdO are the key sensing elements in the proposed approach. Pure and carbon‐doped metal oxides were screen‐printed on Si wafers to form pn‐heterojunctions. All devices were exposed to a disc‐type 137 Cs source with an activity of 370 kBq. The values of radiation damage of pn‐junctions were estimated from changes in their current‐voltage characteristics.
Findings
Sensors showed an increase in the values of current with the increase in radiation dose up to certain levels, exceeding these levels results in unstable dosimetric characteristics.
Originality/value
The sensitivity of metal oxide films to γ‐radiation exposure depends on their composition and thickness. Mixing the oxides in different proportions and the addition of conducting particles, such as carbon, alters films susceptibility to radiation. In particular, sensors based on such films have dose response characteristics with certain level of sensitivity and working dose range, conditioned by particular sensing material properties and the device structure.
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Mohamad Bekhit, Essam Fahim and Asmaa Sobhy
The purpose of this paper is to fall light on the possibility of using the biopolymer chitosan in gamma dose monitoring.
Abstract
Purpose
The purpose of this paper is to fall light on the possibility of using the biopolymer chitosan in gamma dose monitoring.
Design/methodology/approach
The chitosan films were irradiated to gamma rays in the range starting from 10 to 120 kGy at a dose rate of 1.4 kGy/h using 60Co gamma source. The ultra violet and visible (UV/Vis) spectrophotometry were used to examine the optical properties of chitosan film. Also, Fourier transform infrared (FTIR) analysis was used to detect and trace any change in structural bands that may take place upon irradiation.
Findings
Increase in optical density of the chitosan film was recorded at 298 nm that correlated with increasing in the absorbed doses. Change in color of the film from pale yellow to denser yellow was detected upon increasing the absorbed doses. The close investigation for UV/Vis and FTIR analysis nominates the chitosan film to be used as a label-dosimeter in the range of 10–120 kGy depending on chitosan concentrations. The chitosan film has an excellent stability in different environmental conditions with ±3.7% uncertainty in measurements (2σ, approximately equal to a 95% confidence level).
Research limitations/implications
Chitosan film may be used as a medium and high-dose monitor with an acceptable overall uncertainty in routine radiation processing
Originality/value
The useful dose range from 10 to 80 kGy was detected for different concentrations of chitosan (0.5, 1, 1.5 Wt%) that correlated with increasing the absorbed dose, which is assigned to the linear parts in the target response curves. For the dose range 10–120 kGy, the film may be used as label dosimeter with detected color change from pale yellow to dense yellow.
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