Effect Of Gamma Radiation Doses Research Articles

Effect of Gamma Radiation Dose on the Crystal Structure of the Ethylene–Tetrafluoroethylene Copolymer

Effect of Gamma Radiation Dose on the Crystal Structure of the Ethylene–Tetrafluoroethylene Copolymer

Gamma radiation effect on the structural and optical properties of CdS thin films prepared by spray pyrolysis technique

One way to increase the solar cell efficiency is to increase the range of transmitted visible light throughout the window layer. This could be achieved via broadening its band gap; an aim that could be attained through doping and/or irradiation technique. In this way, cadmium sulfide (CdS) thin films have been successfully prepared on pre-heated glass substrates at 400 °C by spray pyrolysis technique and the effect of gamma radiation dose on the structural and optical properties of CdS thin films has been investigated in the range of 250 to 450 Gy. The XRD results manifest the formation of hexagonal phase of CdS with a crystallite size of 58.73 nm, which decreased to 47.26 nm after exposure to 350 Gy. Also, the SEM micrographs show the formation of some randomly oriented groups of nano-rods on the surface of highly condensed nanorods of CdS thin film. The optical investigation illustrates that a blue shift in the optical gap from 2.4 to 3.34 eV has been occurred as the radiation dose reached 350 Gy. The sensitivity of the films to the applied dose has approached 0.005 eV/Gy. Moreover, the shifted band gap exhibited less fading up to 74 days.

Green synthesis of sulfonated cellulose/polyether block amide/polyethylene glycol diacrylate (SC/PEBAX/PEGDA) composite membrane by gamma radiation and sulfonation techniques for battery application

Sulfonated cellulose (SC) was successfully prepared through a two-step process of gamma radiation and subsequently sulfonation with potassium metabisulfite of microcrystalline cellulose extracted from sugarcane bagasse. The effect of gamma radiation dose on cellulose showed an increment of oxidation degree, which was evidenced by the intensity ratio of I1718 (carbonyl)/ I2892 (aliphatic) from FTIR analysis. The obtained SC was introduced into polyether block amide/polyethylene glycol diacrylate (PEBAX/PEGDA) polymer matrix as a reinforcement and hydrophilic filler for improving electrolyte affinity and thermal stability of its composite membrane. The increase of SC in PEBAX/PEGDA composite membranes resulted in enhancement of hydrophilicity, electrolyte uptake, and thermal stability compared to pristine composite membranes. However, the excess SC content in the composite membrane exhibited the low physical properties, caused by negligible dispersion on the surface membrane. With the optimum 2.0 wt% SC in PEBAX/PEGDA, the porosity, contact angle and electrolyte uptake capacity was found to be 64.0 %, 12.8° and 37.5 %, respectively. 2.0 wt% SC/PEBAX/PEGDA showed the outstanding thermal stability with negligible shrinkage <10 % at 150 °C whereas pristine PEBAX/PEGDA showed the shrinkage of 29 %. The obtained SC/PEBAX/PEGDA composite membrane is considered as a potential candidate to replace the commercial polyolefin-based separator in lithium-ion batteries.

Effects of Gamma Radiation Doses on the AC Electrical Properties of Epoxy Reinforced with Nano-Silica Composites

This study reports the effects of gamma radiation on the AC electrical properties of epoxy nano-silica composite sheets with an average thickness of 3 mm. Epoxy reinforced with different nano-silica concentrations of 0, 5, 10, and 15 wt.%. The epoxy nano-silica composites were exposed to different gamma radiation dosages of 1, 3, and 5 kGy. The data were analyzed before and after gamma irradiation and the results showed that the AC electrical properties of the gamma-irradiated epoxy nano-silica composites varied from those of the non-irradiated samples. We found that there were significant changes in the impedance, dielectric constant, dielectric loss, and AC electrical conductivity values of the epoxy nano-silica composites after irradiation, and the AC electrical conductivity and dielectric constant values of the nano-silica composites were enhanced by exposing the samples to gamma radiation because more free electrons were released inside the epoxy nano-silica composites. The AC electrical properties, such as impedance, dielectric constant, dielectric loss, and electrical conductivity, of the epoxy nano-silica composites were studied and discussed before and after gamma radiation with different dosages. We found that these AC electrical properties marginally increased with increasing doses of gamma irradiation.

Dilute GaAs1−xBix epilayers with different bismuth concentrations grown by Molecular Beam Epitaxy: A promising candidate for gamma radiation sensor applications

Radiation interaction studies are very important for exploring the technological applications of new materials in radiation environments. This work reports the effect of gamma radiation dose on the structural and optical properties of dilute GaAs1−xBix epitaxial layers grown with different Bismuth contents by MBE on (100) GaAs substrates. The influence of radiation has been studied by X-Ray Diffraction (XRD), Raman spectroscopy, and photoluminescence (PL) measurements. The samples were also characterized by Scanning Transmission Electron Microscopy (STEM) and Scanning Electron Microscopy (SEM. Gamma radiation (γ-) was found to influence the optical properties of GaAs1−xBix epitaxial layers. From Raman measurements it was found that the concentration of holes increased when the samples were irradiated. This result is in good agreement with photoluminescence results, which showed that the intensity of the main peak increases after irradiation, indicating that the optical properties have improved for all samples. Furthermore, the XRD data revealed that for irradiated GaAs1−xBix samples, the crystallographic quality of the samples was slightly changed after irradiation. This result is consistent with the results of photoluminescence measurements, which demonstrated that the GaAs1−xBix samples exposed to 50 kGy dose showed an increase in photoluminescence and full width at half maximum for all irradiated samples.

SOYBEAN GENERATIONS UNDER GAMMA RAYS AND EFFECTS ON SEED QUALITY

Mutation induction is used to improve existing or generate new varieties. The objective of this study was to evaluate the effect of gamma radiation doses under successive generations of cultivation on seed quality of two soybean lines (VX04-6828 and VX04-5692). Different gamma-ray doses (60Co) were evaluated (0; 50; 150 and 250 Gray) in the M0 (first sowing) generation, and analyzed for water content, germination, vigor, abnormal seedlings, dead seeds, and hilum color. Then, sowing (M0) was carried out to obtain plants and seeds of the first production cycle (M1 generation), and then those of the subsequent cycle (M2 generation). The same analyses of M0 were performed for M2 and M3 generations, with the addition of germination rate and emergence speed index in the field. The data were submitted to analysis of variance in a factorial arrangement. The generations were compared using Tukey’s test, while doses were evaluated by regression analysis. Seeds of the two soybean lines showed significant interaction for the different generations and gamma-ray doses in all the variables analyzed, except for water content. The application of gamma rays in soybean seeds showed effects on successive generations of cultivation, with better physiological quality up to the dose of 150 Gy (Gray) and greater sensitivity to gamma radiation for the VX04-5692 line.

Impact of gamma radiation dose on sterility and quality parameters of Anastrepha fraterculus (Diptera: Tephritidae).

Anastrepha fraterculus (Wiedemann, 1830) (Diptera: Tephritidae) is a major fruit pest, which is basicaly controlled using insecticides, which represents a risk to beneficial arthropods, human health and food contamination. The sterile insect technique (SIT) is a potential alternative tool for the management of this pest, however, only conflicting data is found regarding the optimal dose to achieve sterility. Thus, this study evaluated the effect of gamma radiation doses (0, 40, 50, 60 and 70 Gy) on male and female reproductive sterility, gonads morphometry, emergence, flight ability, and longevity under nutritional stress of A. fraterculus. Full female sterility was achieved at 50 Gy, while full male sterility was achieved at 70 Gy. Both ovarian and testicular sizes were affected by irradiation, while no influence was observed on the quality parameters evaluated. Our results suggest that 70 Gy applied 48 h before adult emergence can be used to sterilize A. fraterculus in a SIT programme.

Effect of Gamma Radiation on Greasy and Scoured Wool, Irradiated in Mini-Bale Form

ABSTRACT The effect of gamma radiation dose on certain properties of wool treated in either greasy or scoured form in mini-bales was investigated. Specific properties studied include color (yellowness and brightness), solubility (alkali solubility and urea-bisulfite solubility), fiber diameter and tensile properties (staple strength and bundle tenacity). The irradiation of the wool was performed in a commercial Cobalt-60 gamma irradiation facility to emulate practical irradiation conditions. It was found that gamma radiation dosages of up to ≈ 90 kGy did not significantly affect the fiber physical dimensions, namely fiber diameter and staple length. Alkali and urea-bisulfite solubility as well as yellowness and brightness, on the other hand, showed a systematic, almost linear, change with an increase in radiation dose. For a dose of ≈ 100 kGy, yellowness increased by ≈ 4.5 (Y-Z) units, brightness decreased by ≈ 7.5 Y units and alkali and urea-bisulfite solubility increased by ≈ 14% (absolute) above their zero dose values.

Evaluation of physicochemical characteristics in cherry tomatoes irradiated with 60Co gamma-rays on post-harvest conservation

The aim of this study was to evaluate the effect of gamma radiation doses on storage in postharvest conservation of cherry tomatoes in relation to physicochemical characteristics. The samples of cherry tomatoes were submitted to gamma radiation from a source of Cobalt-60 type Gammacell-220 at doses of 0.25, 0.50, and 1.0 kGy and non-irradiated samples, and stored at room temperature during maturation. Analyses of moisture content, ash content, pH, titratable acidity, soluble solids (Brix), ratio (soluble solids/titratable acidity), carotenoids, ascorbic acid - vitamin C, firmness, peel and fleshy mesocarp color - lightness (L*) and Chroma (C*) at 1, 7, 14, 21 and 28 days after irradiation (DAI) were performed. An increase of total carotenoids and weight loss has been observed as the irradiation dose increased over storage time of cherry tomatoes. The firmness of irradiated group of cherry tomatoes was lower than that of control non-irradiated from 7 DAI. Irradiation did not alter the values of ash contents (0.50–0.62%), pH (6.8–7.2), and peel color L* (32–41) of cherry tomatoes compared to non-irradiated tomatoes. The storage periods of cherry tomatoes also were responsible for the differences observed in titratable acidity, total carotenoids, vitamin C, weight loss and firmness; therefore, it was affirmed that the fruits presented behaviors equal to those expected, since during the ripening and senescence period there are changes in the physicochemical characteristics of most fruits. Thus, it was concluded that irradiation up to 1.0 kGy gamma-rays could improve sufficiently the postharvest conservation of cherry tomatoes to satisfy the consumer with acceptable nutritional quality.

The Effect of Gamma Radiation on Parthenogenetic Artemia (Branchiopoda, Anostraca) Cysts: Nauplius Hatching and Postnauplial Survival under Varying Salinity

Abstract—The effect of gamma radiation doses of 2.5, 5.5, and 7.5 Gy received by Artemia cysts on hatching of nauplii and postnauplial survival of crustaceans has been studied at salinities of 0, 9, 18, 36, 54, 62, 78, and 88 g/L. Under the same salinities, the above parameters are estimated without irradiation. It has been found that the rate of nauplii hatching from cysts depends primarily on the salinity, the coefficient of determination being equal to 90%. The radiation dose does not affect nauplii hatching at any salinity, except 54 g/L, when a significant negative relationship is found between the proportion of hatched nauplii and the radiation dose. The survival of crustaceans appearing from irradiated cysts depends on the salinity. In the salinity range of 9–52 g/L, it is significantly less than in the range of 62–88 g/L (2.5 and 5.5 Gy). The crustaceans emerged from cysts which received 7.5 Gy do not survive to day 12 at the salinity of 88 g/L. The minimum post-nauplial survival of crustaceans is recorded at a salinity of 54 g/L under all irradiation doses; such salinity may be considered critical for Artemia at which the osmoregulation mechanism reconfigures. Ecological effects in Artemia populations can occur starting from a dose of 2.5 Gy. The studied radiation doses may have remote consequences for Artemia populations in hypersaline water bodies. To quantify the effect of these doses on Artemia populations correctly, it is necessary to study not only the generation of crustaceans immediately hatched from irradiated cysts but also 2–3 subsequent generations.

Effect of gamma radiation dose on the performance of negative-index fiber Bragg gratings

The effect of gamma radiation dose (∼1 MGy) on the performance of negative-index fiber Bragg grating (FBG) formed by prolong UV laser exposure (type-IIa grating) and prolong thermal exposure (thermally regenerated grating) is presented for the first time. It is observed that for both negative-index gratings, the radiation-induced shift in Bragg wavelength and temperature sensitivity were less than 37 pm and 0.06 pm / ° C, respectively. The performance of negative-index grating is also compared with that of positive-index grating (type-I) under the same gamma irradiation conditions. It is observed that variation in Bragg wavelength, reflection intensity, and temperature sensitivity was lower in negative-index gratings compared to that of positive-index grating. The effect of radiation is analyzed in terms of “radiation-optic coefficient” for all FBGs. The different behavior of the FBG is linked with a different mechanism responsible for the formation of negative- and positive-index FBGs.

Влияние гамма-облучения цист партеногенетических Artemia (Branchiopoda, Anostraca) на выход науплиусов и постнауплиальную выживаемость при разной солёности

The effect of gamma radiation doses of 0, 2.5, 5.5 and 7.5 Gy received by Artemia cysts on the hatching of nauplii and post-nauplial survival of crustaceans was studied at salinities of 0, 9, 18, 36, 54, 62, 78 and 88 g/L. Under the same salinities, the above parameters were also estimated without irradiation. It has been found that the rate of nauplii hatching from cysts primarily depends on salinity, the coefficient of determination being 90%. The radiation dose did not affect nauplii hatching at any salinity, except 54 g/L, when a reliable negative relationship between the hatched nauplii fraction and the radiation dose was found. The survival of crustaceans appeared from irradiated cysts depended on salinity. In the salinity range of 9–52 g/L, it was significantly less than in the range of 62–88 g/L (2.5 and 5.5 Gy). The crustaceans came from the cysts received 7.5 Gy did not survive to 12 days at a salinity of 88 g/L. The minimum postnauplial survivorship of the crustaceans was noted at a salinity of 54 g/L under all irradiation doses; this salinity can be considered as critical for artemia, when the osmoregulation mechanism reconfigures. Ecological effects in artemia populations can occur, starting from the dose of 2.5 Gy. The studied radiation doses may have long-term consequences for artemia populations in hypersalinated water bodies. To correctly quantify the effect of these doses on artemia populations, it is necessary to study not only the generation of crustaceans immediately hatched from irradiated cysts, but also 2–3 subsequent generations.

Combined effects of gamma radiation doses and sodium nitrite content on the lipid oxidation and color of mortadella

The effects of different doses of gamma radiation (0–20kGy) on the color and lipid oxidation of mortadella prepared with increasing nitrite levels (0–300ppm) were evaluated using a central composite rotatable design. Higher radiation doses increased the redox potential, promoted the lipid oxidation and elevating the hue color of the mortadellas. Nevertheless, higher addition of sodium nitrite elevated the residual nitrite content, reduced the lipid oxidation and promoted the increase of redness and the reduce of hue color of the mortadellas, regardless of the radiation dose applied. Nitrite addition had a greater effect than irradiation on the quality parameters evaluated, and even at low levels (∼75ppm), its use decreased the deleterious effects of irradiation at doses as high as 20kGy.

THE EFFECT OF THE IONIZING RADIATION ON THE TRIBOLOGICAL PROPERTIES OF THERMOPLASTIC POLYMERS RUBBING AGAINST STEEL

The paper describes the effects of gamma radiation doses on the tribological and mechanical properties of selected thermoplastic polymers: PEEK, PEI, PET, and PA6. Samples of those polymers were irradiated with gamma rays of energy 1, 1.2, 3, 4, 5 MeV and with the intensity of the radiation beam 4, 7, 10, 30, 40 μA. With an increasing dose of radiation, properties such as microhardness, the friction coefficient of polymers, and the wear rate are changed. The chemical structure of the irradiated polymer may be changed by crosslinking but also by chain scission. The modified polymers may be used in medical science, electronics, and space technology. In this article, we report the results of steel C45 – thermoplastics (PEEK, PEI, PET, and PA6) friction couple during the slip motion. The analysis is focused on the friction coefficient, wear rate, and microhardness. Kinematic parameters of the experiment in slide movement were constant and defined by the following values: contact pressure p = 1MPa and sliding velocity v = 1m/s. The authors observed that, as gamma radiation dose increased, the microhardness and friction coefficient increased and their wear intensity decreased. Polymers change their microstructure and molecular structure when they are subjected to gamma ray irradiation, which results in modification on many important physical and chemical properties.

Genetic Diversity in Haploid&lt;i&gt; Nicotiana alata&lt;/i&gt; Induced by Gamma Irradiation, Salt Tolerance and Detection of These Differences by RAPD

Haploid plants of Nicotiana alata were cultured in vitro on MS medium with IAA + KIN. The resulting plantlets were irradiated using gamma radiation doses of 10, 15, 20 and 25 Gy. Single node pieces were cut and transferred onto fresh MS medium. Gamma radiation doses caused the death of 9% and up to 28% of explants. NaCl concentrations caused the death of 8% up to 36% of explants, while the combined effect between gamma radiation doses and salinity had an impact suffused on the percentage of survival. The combined effect of gamma radiation doses 20 Gy and 25 Gy on NaCl concentrations of 100, 150 and 200 mM were deadly. Even more, the combined effect of gamma radiation doses and salinity had a severe negative impact on both the proline content and total soluble protein. Random amplified polymorphic DNA (RAPD) analysis was used to determine the degree of genetic variation in treated haploid Nicotiana alata plants. Total genomic DNAs from different haploid plantlets treated were amplified using five arbitrary primers. Two hundred and seventy bands were detected from plantlets irradiated with doses of 15, 20 and 25 Gy, with polymorphic band number 226 (83.7%). The total number of bands resulted from plant grew on 150 mM and 200 mM NaCl were 260 bands with polymorphic bands 185 (85.6%). However, the total number of bands produced from combined effects between gamma rays and salinity (20 Gy X 50 mM NaCl, 20 Gy X 100 mM NaCl and 25 Gy X 50 mM NaCl) were 270, with polymorphic band number 231 (85.5%). High similarity between treatments was revealed. Treatments relationships were estimated through cluster analysis (UPGMA) based on RAPD data.

Genetic Diversity in Haploid&lt;i&gt; Nicotiana alata&lt;/i&gt; Induced by Gamma Irradiation, Salt Tolerance and Detection of These Differences by RAPD

Haploid plants of Nicotiana alata were cultured in vitro on MS medium with IAA + KIN. The resulting plantlets were irradiated using gamma radiation doses of 10, 15, 20 and 25 Gy. Single node pieces were cut and transferred onto fresh MS medium. Gamma radiation doses caused the death of 9% and up to 28% of explants. NaCl concentrations caused the death of 8% up to 36% of explants, while the combined effect between gamma radiation doses and salinity had an impact suffused on the percentage of survival. The combined effect of gamma radiation doses 20 Gy and 25 Gy on NaCl concentrations of 100, 150 and 200 mM were deadly. Even more, the combined effect of gamma radiation doses and salinity had a severe negative impact on both the proline content and total soluble protein. Random amplified polymorphic DNA (RAPD) analysis was used to determine the degree of genetic variation in treated haploid Nicotiana alata plants. Total genomic DNAs from different haploid plantlets treated were amplified using five arbitrary primers. Two hundred and seventy bands were detected from plantlets irradiated with doses of 15, 20 and 25 Gy, with polymorphic band number 226 (83.7%). The total number of bands resulted from plant grew on 150 mM and 200 mM NaCl were 260 bands with polymorphic bands 185 (85.6%). However, the total number of bands produced from combined effects between gamma rays and salinity (20 Gy X 50 mM NaCl, 20 Gy X 100 mM NaCl and 25 Gy X 50 mM NaCl) were 270, with polymorphic band number 231 (85.5%). High similarity between treatments was revealed. Treatments relationships were estimated through cluster analysis (UPGMA) based on RAPD data.

Adsorption of Lead Ions from Aqueous Solutions Using Gamma Irradiated Minerals

For the first time, an irradiated mineral was used as a novel modified adsorbent for lead removal of aqueous solutions. The effects of gamma radiation doses and temperature on the lead adsorption capacity of an unknown mineral were evaluated. The results show that, in the chemisorption process, the highest adsorption capacity (9.91 mg/g) and the maximum percentage of lead removal (99.1%) were reached at 40°C when using an irradiated mineral at 150 kGy. The improvement on the lead adsorption speed was the most important feature of the irradiated mineral. The experimental results were successfully correlated with the pseudo second-order kinetic model. For all results, the average absolute relative deviations (AARD) were less than 13.20%, and the correlation factor (r2) was higher than 0.998. Moreover, the average values of the thermodynamic parameters (ΔG0=-10612 J/mol, ΔH0=-12360 J/mol, and ΔS0=171 J/mol K) suggest the feasibility of the proposed process, in terms of the endothermic and irreversible chemisorption results; moreover, ion exchange was evaluated through the EDS results. The X-ray diffraction analysis showed that the unknown irradiated mineral is mainly composed of quartz (SiO2), calcite (CaCO3), and calcium magnesium silicate (Ca0.15Mg0.85) Mg (SiO6).

Induced Variation in Tetraploid Rudbeckia subtomentosa ‘Henry Eilers’ Regenerated from Gamma-irradiated Callus

Rudbeckia subtomentosa ‘Henry Eilers’ is an adaptable and popular garden plant; however, reduction in height and increased novelty in flower color would be desirable. The effect of gamma radiation dose on in vitro survival and development, and ex vitro fertility, phenology, and morphology of tetraploid Rudbeckia subtomentosa ‘Henry Eilers’ was investigated. In vitro embryogenic callus was treated with gamma radiation (0, 5, 10, 20, or 40 Gy). Rooted microshoots were established ex vitro and evaluated for morphology (plant height, number of flowers, diameter of the terminal flowers, diameter of the secondary flowers, number of stems, number of nodes, and internode length), date of first anthesis, winter survival, and pollen fertility on mature, second-year plants. Callus survival had no response to dose 2 months after treatment; however, microshoot number was significantly reduced with increasing dose. In vitro microshoot survival continued to decline at higher doses up to 4 months after treatment. Plant height, average stem height, number of flowers, flower diameter, percent winter survival, and pollen viability were all reduced with increasing radiation dose. Date of first anthesis was also delayed with increased radiation dose. Several off phenotypes were recorded including increased apical splitting of the ray florets in several plants. Gamma radiation was somewhat effective for reducing the height of R. subtomentosa ‘Henry Eilers,’ but flower morphology, flower number, and plant overwintering survival were often negatively affected with increasing radiation dose. Treating callus with low levels of gamma radiation (5–10 Gy) resulted in relatively high in vitro and field survival while inducing a range of other mutations that could be selected.

Qualidade microbiologica da carne de frango irradiada em embalagem convencional e a vácuo

Foram avaliados os efeitos da radiação gama nas doses de 1,5 e 3,0kGy, em peitos de frango embalados em embalagem convencional e a vácuo. As amostras embaladas foram submetidas à irradiação e estocadas sob refrigeração (4ºC) por 30 dias. A radiação mostrou-se eficiente na redução de mesófilos aeróbios estritos e facultativos viáveis, coliformes totais e termotolerantes, com destaque para Salmonella spp. Os bolores e leveduras mostraram-se bastante resistentes à radiação. Os resultados sugerem que a dose de 3,0kGy pode ser utilizada no controle da microbiota do peito de frango armazenado sob refrigeração, sendo uma alternativa para o aumento da vida de prateleira por até 10 dias, ao garantir a segurança do consumidor pela eliminação de possíveis patógenos.

Effects of radiation and storage time on conductive NBR/LDPE blends

The electrical conductivity, σ, of conductive acrylonitrile-butadiene rubber (NBR) mixed with different concentrations (1, 3 and 5 phr) of low-density polyethylene (LDPE) is presented. The effect of gamma radiation doses in the range 5 to 50 kGy on the electrical conductivity was determined for all samples. Storage of the unirradiated and irradiated samples for 7 days at 60 or 100 °C has a great influence on the electrical conductivity of these blends. The variation in the conduction mechanisms through these blends on both irradiation and storage is also discussed.