Electron Beam Irradiation Dose Research Articles

Electron beam irradiation induces abnormal development and the stabilization of p53 protein of American serpentine leafminer, Liriomyza trifolii (Burgess)

The American serpentine leafminer fly, Liriomyza trifolii (Burgess), is one of the most destructive polyphagous pests worldwide. In this study, we determined electron beam doses for inhibition of normal development of the leaf miner and investigated the effect of electron beam irradiation on DNA damage and p53 stability. Eggs (0–24 h old), larvae (2nd instar), puparia (0–24 h old after pupariation) and adults (24 h after emergence) were irradiated with increasing doses of electron beam irradiation (six levels between 30 and 200 Gy). At 150 Gy, the number of adults that developed from irradiated eggs, larvae and puparia was lower than in the untreated control. Fecundity and egg hatchability decreased depending on the doses applied. Reciprocal crosses between irradiated and unirradiated flies demonstrated that males were more radiotolerant than females. Adult longevity was not affected in all stages. The levels of DNA damage in L. trifolii adults were evaluated using the alkaline comet assay. Our results indicate that electron beam irradiation increased levels of DNA damage in a dose-dependent manner. Moreover, low doses of electron beam irradiation led to the rapid appearance of p53 protein within 6 h; however, it decreased after exposure to high doses (150 Gy and 200 Gy). These results suggest that electron beam irradiation induced not only abnormal development and reproduction but also p53 stability caused by DNA damage in L. trifolii. We conclude that a minimum dose of 150 Gy should be sufficient for female sterilization of L. trifolii.

An approach for vat color printing on cotton and polyester fabrics with electron beam irradiation curable formulations

► Electron beam irradiation was used as a new fixation tool of vat dyes. ► The radiation curable formulations free from reducing agent and thickener. ► This process reduces all the processes of conventional method in one step. ► The effective conditions were: monomer/oligomer ratio of (25/75 wt%) and irradiation dose of 75 kGy. ► Vat printing by electron beam affords color yield higher than the conventional method. Accelerated electrons delivered by electron beam accelerator were used to fix vat colors, incorporated in curable formulations containing diluting monomer and an oligomer, to cellulosic fabric, cotton and polyester fabric. Tetrahydrofurfuryl acrylate, hexane dioldiacrylate, monomers and trifunctional urethane methacrylate, oligomer were used as curable base beside ethylene glycol. The fabrics were printed with these formulations and exposed to various doses of electron beam irradiation generated from the 1.5 MeV (25 kW) electron beam accelerator machine. Critical factors included the irradiation dose, formulation composition, and vat color concentration were studied. The fabrics printed with the vat colors by electron beam irradiation displayed higher color yield than those fabrics printed by the conventional curing at equal vat color ratios. The durable properties of fabrics printed by electron beam irradiation except the roughness properties are extremely better than those printed by conventional fixation method.

EFFECT OF ELECTRON BEAM RADIATION ON HEMATOPOIETIC CELLS OF SWISS ALBINO MICE

AbstractIonizing radiation which results in the free radical formation and it leads to damage of biological macromolecules such as DNA, proteins, lipids. 36 male Swiss albino mice were used for survival assay, to find out the lethal dose of Electron Beam Radiation. It was found to be 10Gy was the lethal dose for mice. Different dosages (4Gy, 6Gy and 8Gy) of electron beam radiation were used to study the micronucleus formation in irradiated mice. The results showed micronucleus formation will increase linearly with radiation dosage.

The Characterization of Different Doses of Electron Beam Irradiation on the Structure and Properties of PAN Precursor Fibers

Different doses of electron beam was imposed on polyacrylonitrile(PAN) precursor fibers before the fibers were stabilized. The effect of electron beam irradiation on the chemical structure, orientation degree, surface morphology and tensile properties of PAN precursor fibers were characterized by use of fourier transform infrared spectroscopy (FTIR), tensile test and scanning electron microscope (SEM), respectively. The results showed that the extent of cyclization and orientation degree was increased firstly and decreased later. The surface morphology of PAN precursor fibers was smoother when the irradiation doses 150kGy and 200kGy. Tensile strength of the fibers was increased first and decreased later. The change of tensile strength might be in correlation with the changes of extent of cylization, orientation factor and surface morphology.

Mechanical properties of rice straw fiber-reinforced polymer composites

Rice straw fibers have been used as reinforcing fillers in different polymers, tow composites were prepared by using polyvinyl alcohol and polystyrene polymers with different ratio of polymers. The pressed samples were subjected to various electron beam irradiation dose. The results indicated that, flexural strength, impact strength and modulus of elasticity increase with increasing the polymer ratio in the mix composition. It was found that the water absorption and thickness swelling percentages of rice straw fiber polystyrene composites decrease with increasing the polystyrene content in the same composition, while its values for rice straw polyvinyl alcohol composites improve. These are attributed to hydrophobic and hydrophilic characteristics of the tow composites. The improvement of physico-mechanical properties of both composites with the increase of electron beam irradiation dose are probably attributed to randomly initiated chain reactions, which started by the reactive centers created by electron beam. These observations were confirmed by IR spectrometer and SEM studies.

Effect of Silane Coupling Agents on Rice Straw Fiber/Polymer Composites

The effect of coupling agents and electron beam (EB) irradiation dose on the mechanical properties of composites made from rice straw fibers and polymers have been studied. Samples were made by hot pressing of mix composition at 130°C. The pressed samples were subjected to electron beam irradiation dose ranged from 10 to 50 kGy. Increasing the electron beam irradiation dose increased the value of flexural strength, modulus of elasticity and impact strength. It was also observed that, the properties of composites containing γ-aminopropyltrimethoxy silane (A-1100) are lower than those of composites containing N-(2aminoethyl)-3-amino propyltrimethoxy silane (A-700) coupling agents. These are attributed to a hydrogen bonding formation between the amine or protonated amine and the hydroxyl groups of rice straw fibers. The presence of coupling agents in the composites during the EB irradiation process produce a more free radicals which are enough to form a chemical bonding between the rice straw fiber and polymer. The thickness swelling and water absorption values decrease with increasing the EB irradiation dose with presence of coupling agents in the composite.

Development of a Thermoplastic Olefin Blend Embo-Pattern Sheet Cross-linked by Electron Beam Irradiation for Luxurious Automotive Interior Parts

Many automakers are developing instrument panels with embo-patterns to make more luxurious interior parts for compact cars. The economical male vacuum forming process helps to make parts with embo-patterns price competitive, but embo-pattern loss is greater than that observed with a female vacuum forming process. In the current study, we developed a thermoplastic olefin blend embo-pattern sheet, cross-linked by electron beam irradiation, to minimize embo-pattern loss incurred during part forming in the male vacuum process. The electron beam irradiation dose and materials mixture in the sheet were optimized, improving the retention rate of embo-patterns by almost 3-fold with an electron beam irradiation dose of 80 kGy. At 80 kGy, the product met all property requirements of sheets developed for instrument panel applications and the performance evaluation for airbag deployment. Additionally, this instrument panel production is expected to result in improved price competitiveness, with a savings of more than 10%.

Electron beam processed plasticized epoxy coatings for surface protection

Epoxy acrylate oligomer (EA) was plasticized by adding different plasticizers such as epoxidized soybean oil, glycerol and castor oil and cured by electron beam (EB). Different irradiation doses (1, 2.5 and 5 Mrad pass −1) were used in the curing process. The effect of both different irradiation doses and plasticizers on the end use performance properties of epoxy acrylate coating namely, pencil hardness, bending test, adhesion test, acid and alkali resistance test were studied. It was observed that incorporation of castor oil in epoxy acrylate diluted by 1,6-hexanediol diacrylate (HD) monomer with a ratio (EA 70%, HD 20%, castor oil 10%) under 1 Mrad pass −1 irradiation dose improved the physical, chemical and mechanical properties of cured films than the other plasticizer. Sunflower free fatty acid was epoxidized in situ under well established conditions. The epoxidized sunflower free fatty acids (ESFA) were subjected to react with aniline in sealed ampoules under inert atmosphere at 140 °C. The produced adducts were added at different concentrations to epoxy acrylate coatings under certain EB irradiation dose and then evaluated as corrosion inhibitors for carbon steel surfaces in terms of weight loss measurements and corrosion resistance tests. It was found that, addition of 0.4 g of aniline adduct to 100 g epoxy acrylate formula may give the best corrosion protection for carbon steel and compete the commercial corrosion inhibitor efficiency with the same concentration.

Ionic conductivity study on electron beam irradiated polyacrylonitrile—polyethylene oxide gel

Different mass percent polyacrylonitrile (PAN)—polyethylene oxide (PEO) gels were prepared and irradiated by an electron beam (EB) with energy of 1.0 MeV to the dose ranging from 13 kGy to 260 kGy. The gels were analysed by using Fourier transform infrared spectrum, gel fraction and ionic conductivity (IC) measurement. The results show that the gel is crosslinked by EB irradiation, the crosslinking degree rises with the increasing EB irradiation dose (ID) and the mass percents of both PAN and PEO contribute a lot to the crosslinking; in addition, EB irradiation can promote the IC of PAN—PEO gels. There exists an optimum irradiation dose, at which the IC can increase dramatically. The IC changes of the PAN—PEO gels along with ID are divided into three regions: IC rapidly increasing region, IC decreasing region and IC balanced region. The cause of the change can be ascribed to two aspects, gel capturing electron degree and crosslinking degree. By comparing the IC—ID curves of different mass percents of PAN and PEO in gel, we found that PAN plays a more important role for gel IC promotion than PEO, since addition of PAN in gel causes the IC—ID curve sharper, while addition of PEO in gel causes the curve milder.

Effects of electron-beam and gamma irradiation treatments on the microbial populations, respiratory activity and sensory characteristics of Tuber melanosporum truffles packaged under modified atmospheres

The effects of electron-beam or gamma irradiation (doses of 1.5 kGy and 2.5 kGy of either one) on the microbial populations, respiratory activity and sensory characteristics of Tuber melanosporum packaged under modified atmospheres were monitored immediately after treatment, and subsequently every seven days during 35 days of storage at 4 °C. Treatments with 1.5 and 2.5 kGy reduced the total mesophilic aerobes counts respectively by 4.3 and 5.6 log cfu/g for electron-beam treatment, and by 6.4 and 6.6 log cfu/g for gamma irradiation. Other microbial groups studied (Pseudomonas genus, Enterobacteriaceae family, lactic acid bacteria, mesophilic aerobic spores, molds and yeasts) were not detected after the treatments. A decrease in the respiratory activity was detected in all the irradiated batches, indicating that the carbon dioxide levels were lower and the oxygen levels higher than those of the non-irradiated ones. Two species of yeasts, Candida sake and Candida membranifaciens var. santamariae, survived the irradiation treatments and became the dominant microbial populations with counts of up to 7.0 log cfu/g. The growth of these microorganisms was visible on the surface of irradiated truffles from day 21 onwards, affecting the flavor and the general acceptability of the ascocarps. Moreover, a watery exudate was detected in the treated truffles from the third week onwards, so the application of irradiation treatments in doses equal to or above 1.5 kGy did not preserve the quality characteristics of T. melanosporum truffles beyond 28 days.

Study of the migration behavior of acetyl tributyl citrate from PVDC/PVC film into fish fillets as affected by intermediate doses of electron beam radiation

Food-grade plasticized polyvinylidene chloride/polyvinyl chloride (PVDC/PVC) film (saran wrap) containing acetyl tributyl citrate (ATBC) plasticizer was used to wrap cod and herring fillets. The ratio of film surface to weight of food was ca. 89:1, in contrast to the generally agreed relationship of 6 dm2 to 1 kg food (6:1). Wrapped fish samples were subjected to electron beam irradiation at doses equal to 5 and 10 kGy, stored at 4 °C and analyzed for ATBC content at time intervals between 12 and 240 h of contact. Determination of the analyte was performed by ultrasonic-assisted solvent extraction followed by analysis on a gas chromatograph coupled with flame ionization detector. Final ATBC concentrations in cod fillets ranged from 11.1 to 12.8 mg/kg, while the corresponding values for herring samples were between 32.4 and 33.4 mg/kg. Data showed that e-beam radiation at pasteurizing doses did not significantly affect the copolymer’s specific migration characteristics. On the contrary, fat content of the packaged fish fillets substantially affected the diffusion coefficient (D) values, as well as the extent to which migration of ATBC occurred. No violations of the tolerable daily intake (TDI) of 1.0 mg/kg body weight set by the EU for ATBC were found in the present study. However, food overwrapping or rewrapping with flexible films is often applied in household applications. Since in such cases unrealistically high plasticizer concentrations are determined experimentally, present specific migration limits (SML) should be redefined on a different basis.

Effect of Electron Beam Irradiation on Physico-Mechanical and Chemical Properties of NBR–PVC Loaded with Cement Kiln Dust

Rubber blends based on acrylonitrile butadiene rubber and poly(vinyl chloride) (NBR–PVC) were loaded with different contents of treated cement kiln dust (CKD) of up to 30 phr with a silane coupling agent and stearic acid. The prepared composites were subjected to electron beam irradiation doses of up to 150 kGy to induce radiation vulcanization under atmospheric conditions. Mechanical properties in terms of tensile strength (TS), tensile modulus, elongation at break and hardness were studied as a function of irradiation dose and degree of loading with filler. Furthermore the soluble fraction, swelling ratio and cross-link density physical properties were measured as a function of filler content and irradiation dose. In addition, the thermal behavior of the prepared composites was also investigated. The results obtained indicated that an improvement had been attained in the different properties of loaded (NBR–PVC) composites with the treated cement kiln dust.

Effects of electron-beam irradiation on the shelf life, microbial populations and sensory characteristics of summer truffles ( Tuber aestivum) packaged under modified atmospheres

The effects of two doses of electron-beam irradiation (1.5 kGy and 2.5 kGy) on the microbial populations (total mesophilic aerobes, Pseudomonas genus, Enterobacteriaceae family, molds and yeasts) and sensory characteristics of Tuber aestivum packaged under modified atmospheres were monitored immediately after treatment, and weekly during 42 days of storage at 4 °C. Treatment with 1.5 and 2.5 kGy reduced the pseudomonads populations by 4.3 and 5.5 logs, respectively. Enterobacteriaceae counts decreased by 5.4 logs with the 1.5 kGy dose and counts below the detection limit (<1.0 log cfu/g) were obtained with the 2.5 kGy dose. Lactic acid bacteria and yeasts were less affected by the ionizing radiation treatments and they became the dominant microbial populations throughout storage with microbial counts up to 7.1 log cfu/g. The carbon dioxide levels inside the packages containing irradiated truffles were lower than those of the non-irradiated ones, suggesting a decrease in the respiration rate of the treated ascocarps. The treatments with 1.5 and 2.5 kGy e-beam did not negatively affect the sensory characteristics of truffles, but a visible superficial yeast growth was detected in truffles irradiated with 1.5 kGy at the end of their shelf life (day 28). Treatment with 2.5 kGy e-beam has prolonged the shelf life to 42 days, compared with 21 days for the untreated samples.

Atom transfer radical polymerization of graft chains onto polyethylene film initiated at tribromomethyl unit introduced by electron beam irradiation

AbstractA novel process for graft polymerization onto a polyethylene (PE) film using atom transfer radical polymerization (ATRP) was examined. First, a PE film irradiated with an electron beam was treated with carbon tetrabromide, thereby introducing tribromomethyl groups. The number of tribromomethyl groups introduced onto the film could be controlled by adjusting the electron beam irradiation dose. Methyl methacrylate (MMA) was then graft‐polymerized by ATRP in the initiator‐introduced PE film in the presence of a copper catalyst. Based on FTIR spectra from the PMMA grafted films, the behavior of graft polymerization reactions on the film surface and inside the film are discussed. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

Impact of Electron Beam Irradiation on Fatty Acid Profile of Canavalia Seeds

The present study provided an evidence for selective changes of the fatty acid methyl esters (FAMEs) of Canavalia seeds and the low doses of electron beam irradiation (EBI; 2.5 and 5 kGy) serve as hormetic doses for selective enhancement of fatty acids. The total lipids and FAMEs of irradiated Canavalia cathartica and Canavalia maritima seeds of the coastal sand dunes of Southwest India were assessed using soxhlet extraction and chloroform–methanol–water extraction (Bligh and Dyer) methods followed by gas chromatography. As the EBI dose increased, total lipid extraction decreased by soxhlet method in seeds of C. cathartica, while it was reverse in C. maritima. Among the doses, 5 and 10 kGy resulted in the highest extraction of lipid by the Bligh and Dyer method in C. maritima and C. cathartica, respectively. A great variation in FAMEs profile of Canavalia seeds subjected to EBI was seen by the soxhlet and Bligh and Dyer methods of extraction. The EBI increased saturated fatty acids in both the seeds. The unsaturated fatty acids were decreased by EBI based on the soxhlet extraction (except for 15 kGy in C. maritima), while a dose-dependent increase was shown by the Bligh and Dyer method on attaining the highest at the doses 5 kGy (C. maritima) and 10 kGy (C. cathartica). The changes in medium chain fatty acids, long chain saturated fatty acids, mono- and polyunsaturated fatty acids, and ratios of fatty acids were dependent on the seed material, the dose EBI, and the method of extraction.

Effect of Electron Beam Irradiation on Postharvest Quality and Selected Enzyme Activities of the White Button Mushroom,Agaricus bisporus

Agaricus bisporus fruit bodies were exposed to different doses (1, 2, 3, and 4 kGy) of electron beam irradiation (EBI), and various physiological changes associated with postharvest deterioration, as well as selected enzymes considered to play a role in senescence, were monitored over a subsequent 16-day storage period at 4 degrees C and 75-85% relative humidity. EBI retarded postharvest mushroom softening and overall increases in malondialdehyde levels were more pronounced in controls compared with those of the irradiated samples. After 10 days of storage, polyphenoloxidase activity in samples irradiated with 1-4 kGy doses was significantly (P<0.05) lower compared to that in control samples. Superoxide dismutase activity generally declined throughout the postharvest storage period in both irradiated and control samples, but no clear correlation between enzyme activity and EBI dosage was evident. Catalase activity decreased more slowly and to a lesser extent in fruit bodies exposed to 1 kGy compared with that in the controls and the other irradiated samples.

Microbial quality evaluation and effective decontamination of nutraceutically valued lotus seeds by electron beams and gamma irradiation

Lotus seeds are nutraceutically valued natural plant produce, which succumbs to microbial contamination, predominantly to toxigenic moulds. Results of the present study revealed seed coat portion to harbor higher proportion of microbial load, particularly fungi than cotyledon portion. Among the mycotoxins analyzed, aflatoxins (B 1, B 2, G 1 and G 2) were below detectable limits, while the seeds were devoid of Ochratoxin-A (OTA). Application of different doses of electron beam and gamma irradiation (0, 2.5, 5, 7.5, 10, 15 and 30 kGy) for decontamination purpose revealed significant dose-dependent decrease in the fungal contaminants ( P<0.05). However, the contaminant yeasts could survive up to 10 kGy dose, which could be completely eliminated at 15 kGy. From the results obtained, a dose range between 10 and 15 kGy is recommended for complete decontamination, as these doses have also been shown earlier to have minimal effects on nutritional and functional properties of lotus seeds.

Engineering properties of electron beam‐crosslinked ethylene methyl acrylate copolymer

AbstractEffect of electron beam on mechanical, thermal, and morphological properties of ethylene methyl acrylate copolymer, grade Elvaloy 1335 has been investigated. The copolymer was subjected to varying doses of electron beam radiation with different proportion of the sensitizer trimethylolpropane trimethacrylate (TMPTMA). It was observed that with increase in electron beam dose, the physicomechanical properties of the crosslinked copolymer improve, reaches an optimum level and subsequently deteriorates. The thermal properties as envisaged from thermogravimetric analysis and differential scanning calorimetric studies revealed stability of the crosslinked irradiated samples over that of the unirradiated ones. The thermal stability was also found to attain the maximum at the same level of radiation and sensitizer. The morphological studies showed consistency with the mechanical properties. Based on the overall study, it may be concluded that ethylene methyl acrylate copolymer with 1 phr TMPTMA at 60 kGy radiation dose is the optimum condition within the range studied in this investigation. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010

Improving Enzymatic Saccharification of Hybrid Poplar by Electron Beam Irradiation Pretreatment

The effects of electron beam irradiation pretreatment on the structural and compositional features and on the enzymatic saccharification of hybrid poplar were investigated. The carbohydrate compositional analyses with 1H-NMR spectroscopic method were applied in this study to investigate the change in the polysaccharides of hybrid poplar quantitatively. As the irradiation dose increased, the amount of extract produced in mild alkaline extraction was increased. The composition of the residual biomass after mild alkaline extraction was also changed depending on the electron beam irradiation dose. Especially for xylose, the peak intensity in NMR spectra was decreased with increasing electron irradiation dose, which demonstrated the significant decomposition of xylan caused by the electron beam irradiation. The changes induced by electron beam irradiation resulted in a better response to enzymatic hydrolysis with commercial cellulases (Celluclast 1.5 L and Novozym 342). More improvement in enzymatic hydrolysis by the irradiation was found in the hydrolysis of the xylan than that of the cellulose in hybrid poplar.

Effect of electron beam irradiation on the electrochemical properties of heteropolyacid–polyethylene oxide composite electrolyte for dye-sensitized solar cell

A composite electrolyte for dye-sensitized solar cell (DSSC) was prepared with heteropolyacids (HPA) and polyethylene oxide (PEO) in the mixture solvent of chloroform and methanol. The amorphicity and ionic conductivity of the HPA–PEO composite electrolytes were significantly enhanced upon the appropriate dose of electron beam (e-beam) irradiation in the range of 40–120 kGy. A DSSC fabricated with HPA–PEO irradiated at the optimum dose of 120 kGy showed maximum overall conversion efficiency of 3.4% with a V OC of 0.588 V, I SC of 9.68 mA/cm 2 and fill factor of 58.9% under 100 mW/cm 2, which improved by 13% efficiency in comparison with the DSSC with bare HPA–PEO composite electrolytes.