• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.34 no.2
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• pp.130-135
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• 2021

Wrinkle patterns were fabricated on styrene-butadiene-styrene (SBS) block copolymer substrates using ion-beam (IB) irradiation with various intensities. The wavelength of the wrinkle pattern increased as the IB intensity was increased from 800 to 1,600 eV. IB irradiation-induced changes in the surface properties that were confirmed via physicochemical surface analyses. X-ray photoelectron spectroscopy analysis revealed chemical surface reformation due to the IB irradiation, resulting in C-O/C=O bonds after IB irradiation that were not reported before. These results indicate that the surface chemical modification caused by IB irradiation is strongly related to the surface modulus, which is important when fabricating wrinkle patterns. Furthermore, a strong IB irradiation induced a strong compressive strain; thus the size of the wrinkle pattern was increased.

• Journal of the Korean Society of Food Culture
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• v.13 no.4
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• pp.275-291
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• 1998

Food irradiation is an emerging technology which offers many advantages such as reduction of microorganisms, extension of shelf-life of foods, reduction in the use of post-harvest chemicals, and destruction of insects and parasites. The commercial utilization of food irradiation, however, has been restricted because of the uncertainty of consumers' responses to it. Because success of food irradiation in the marketplace will depend upon their acceptability by consumers, this study focused on the consumers' perception and acceptance toward food irradiation in order to get basic data for commercial utilization of food irradiation and give information to consumers to help rational consumption behavior. The survey with 411 respondents living in Youngnam area was conducted during the spring of 1997 by the questionnaires. The results and implications from this study are as follows. First, consumers' knowledge about food irradiation is scanty. Two-thirds of respondents in the survey had not heard of irradiated foods and many people confused irradiation with radioactivity. In the willingness to accept food irradiation, one-third of respondents showed a wait-and-see attitude. This result indicated consumers had insufficient information about the irradiation process and nationwide education of food irradiation technology should be undertaken. Second, although the purchase and use of food are very important consumption behaviors, consumer education by mass communication has been rarely done. For the successful commercialization of food irradiation, the information provision by mass communication for the consumers should be made. Third, consumers generally worried about residual pesticide and intended to purchase irradiated foods if radioactivity was not retained in the foods. Therefore, food irradiation could be an alternative method to the use of pesticide Fourth, consumers pointed out that they wanted to extend shelf-life of milk and dairy foods, fish and seafood and to irradiate these foods. Therefore, research for the safety of irradiated foods should be continually conducted. finally, labeling for irradiated foods is needed to provide the information and to further increase public understanding. Especially, the labeling should show the definite reason why irradiation is being used. In conclusion, recently, under the circumstances that the commercial utilization of food irradiation and irradiation for the import and export products have been increased in many countries, many efforts are needed to improve the quality of irradiated foods, and prove the safety of them in Korea. In addition, consumer education for food irradiation should be given to help consumers to make decision for food purchase and use.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.25 no.1
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• pp.71-87
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• 1995

The purpose of this study was to investigate the early irradiation changes on the ultrastructure of the capillary endothelial cell in the rat submandibular glands. For the study, 110 Sprague-Dawley strain male rats were singly irradiated to their neck regions with the doses of 2Gy, 5Gy, and 10Gy by 6MV X -irradiation, and sacrificed on the 3 hours, 6 hours, 12 hours, 1 day, 3 days, 7 days, and 14 days after irradiation. The authors observed the histologic and ultrastructural changes of the capillary endothelial cell using the light and electron microscopes. The results were as follows: I. In the light microscopic examination, the capillary dilation was observed on the 6 hours group and the capillary density was slightly increased on the 12 hours group after 2Gy and 5Gy irradiation. And luminal size and capillary density were decreased on the 3 days and the 7 days groups after irradiation, after then, they were recovered. But capillary density was still decreased on the 14 days group after 10Gy irradiation. 2. In the transmission electron microscopic examination, the mild proliferation of cytoplasmic process of the endothelial cell and reduction in luminal size were observed on the 3 hours group after irradiation. After then, endothelial swelling, marked proliferation of cytoplasmic process, thickened basal lamina, and numerous pinocytotic vesicles were observed after the 1 day group after irradiation. Thickened basal lamina and numerous pinocytotic vesicles were still observed until the 7 days group after irradiation. These changes were recovered to normal on the 14 days group after 2Gy and 5Gy irradiation, but not after 10Gy irradiation. 3. In the scanning electron microscopic examination, the dilation of conduits and constriction, and meandering were observed on the 1 day group after 10Gy irradiation. These changes were observed with increased coarseness of the surface of the vascular resin casting on the 3 days group after irradiation. 4. From the above results, endothelial swelling, proliferation of cytoplasmic process, and thickening of the basal lamina appeared before the 6 hours group after irradiation. And these changes may also induce the increase of the capillary number and luminal size, after then, capillary permeability was increased via the increase of the number of pinocytotic vesicles. The changes were observed earlier and more apparent with the increase of the irradiation doses under the dose of 10Gy irradiation.

• Imaging Science in Dentistry
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• v.35 no.3
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• pp.133-139
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• 2005

Purpose To observe the histopathological changes in the periodontal tissues of mandibular molars in streptozotocin-induced diabetic rats after irradiation. Materials and Methods : The male Sprague-Dawley rats weighing approximately 250 gm were divided into four groups: control, diabetes, irradiation, and diabetes- irradiation groups. Diabetes mellitus was induced in the rats by injecting streptozotocin. Rats in the control and irradiation groups were injected with citrate buffer only After 5days, the head and neck region of the rats in irradiation and diabetes-irradiation groups were irradiated with a single absorbed dose of 10Gy. All the rats were sacrificed at 3, 7, 14, 21, and 28 days after irradiation. The specimen including the mandibular molars were sectioned and observed using a histopathological method. Results In the diabetes group, osteoclastic activity was observed in the alveolar bone and the root throughout the period of experiment. Also, osteoblastic and fibroblastic activities were markedly decreased. In the irradiation group, the osteoclasts were observed in the alveolar bone and the dilated capillaries were increased in the early experimental phases. However, vigorous osteoblastic activity was noted in the late experimental phases. In the diabetes-irradiation group, osteoblastic activity in the alveolar bone and the root was observed in the early experimental phases. However, there were no resorption and osteoblastic activity in the alveolar bone and the root in the late experimental phases, and obvious atrophic change of fibrous tissues was noted. Conclusion : This experiment suggests that osteoblastic activity was caused by irradiation in the late experimental phases, but atrophic change of the periodontal ligament tissues was induced after irradiation in diabetic state.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.4
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• pp.334-338
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• 2003

The objective of this study was to demonstrate whether or not the deleterious effects of accelerated aging on seed vigour and viability are alleviated by interaction with gamma irradiation. Seeds of soybean (Glycine max L.) were artificially aged and subsequently irradiated with 4 and 8 Gy of gamma irradiation. Germination rate was negatively affected by accelerated aging and positively by gamma irradiation, with a positive interaction of a 3day-seed aging treatment occurring with 4 Gy, possibly suggesting that 4 Gy of gamma irradiation partially offset the adverse effects of seed aging on germination. However, 5-day aged seeds did not gain any benefits from the gamma irradiation. Electrolyte leakage from the seeds increased with the duration in days aged. Irradiation, however, did not impose any effects on the leakage. Respiration rate of the seed with hypocotyl and primary root was significantly low for the aged seeds, but not for the seeds with both irradiation and aging treatments. Accelerated aging decreased the dry weight of the hypocotyl and primary root of the seeds without any measurable effects of irradiation. $\alpha$-Amylase activity decreased with seed aging and positively responded to gamma irradiation. The data is discussed with regard to the possible roles of gamma irradiation for improving the seed vigour and viability of aged seeds.

• Journal of Biomedical Engineering Research
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• v.31 no.1
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• pp.81-86
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• 2010

Laser irradiation is known to affect various tissues such as skin, bone, nerve, and skeletal muscle. Laser irradiation promotes ATP synthesis, facilitates wound healing, and stimulates cell proliferation and angiogenesis. In skeletal muscle, laser irradiation is related to the proliferation of skeletal muscle satellite cells. Normal skeletal muscle contains remodeling capacity from myogenic cells that are derived from mononuclear satellite cells. Their processes are activated by the expression of genes related with myogenesis such as muscle-specific transcription factors (MyoD and Myf5) and VEGF (vascular endothelial growth factor). In this study, we hypothesized that laser irradiation would enhance and regulate muscle cell proliferation and regeneration through modulation of the gene expressions related with the differentiation of skeletal muscle satellite cells. $C_2C_{12}$ myoblastic cells were exposed to continuous/non-continuous laser irradiation (660nm/808nm) for 10 minutes daily for either 1 day or 5 days. After laser irradiation, cell proliferation and gene expression (MyoD, Myf5, VEGF) were quantified. Continuous 660nm laser irradiation significantly increased cell proliferation and gene expression compared to control, continuous 808nm laser irradiation, and non-continuous 660nm laser irradiation groups. These results indicate that continuous 660nm laser irradiation can be applied to the treatment and regeneration of skeletal muscle tissue.

• Journal of the Korean Home Economics Association
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• v.30 no.4
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• pp.77-88
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• 1992

To investigate the oxidative stabilities of the ${\gamma}$-ray irradiated soybean during storage and heating and some physico-chemical characteristics of soybean and the extracted soybean oil (SBO) with/without the ${\gamma}$-ray irradiation were determined. The ${\gamma}$-ray level use in irradiation for soybean were 2.5, 5.0 and 10.0 KGY respectively and Acid Value, Peroxide Value, Conjugated Diene Value, Composed Fatty Acids amounts, and Trans Fatty Acid occurrence were determined for all samples, which were incubated at 45$\pm$1$^{\circ}C$ for 25 days heated at 180$\pm$1$^{\circ}C$ for 30 hours. And these values of the ${\gamma}$-ray treated samples were compared to those of nontreated samples. The results were obtained as follows : 1. According to the increased level of the ${\gamma}$-ray irradiation, there was little difference in Dielectric Constant, Viscosity, and the Induction Period by Rancimat. But, in case of 5.0 KGY, oxidative stability was increased more twice than that of non-irradiation. In the quantity of fatty Acids composition of the extracted soybean oil irradiated with 10.0 KGY, palmitic, oleic and linoleic acids were less increased thanb those of non-irradiation, while stearic, linolenic acids were decreased. In the case of 2.5 KGY irradiation, stearic and oleic acids were increased. 2. The Acid Value of SBO according to the ${\gamma}$-ray irradiation level was almost not change, but was 0.1 lower than that of non-irradiation during incubation (45$\pm$1$^{\circ}C$). The Peroxide Value of SBO with the ${\gamma}$-ray irradiation, was very lower than that of non-irradiation, but its effect on oxidative stability was better of SBO treated with 5.0 KGY and 10.0 KGY. In the Fatty Acids composition of SBO, palmitic, stearic, oleic acids were increased, while linoleic, linolenic acids were decreased during incubation(45$\pm$1$^{\circ}C$). This tendency was more obvious due to the ${\gamma}$-ray level. While heating(180$\pm$1$^{\circ}C$), the Acid Value of SBO treated with the ${\gamma}$-ray irradiation was decreased, the Acid Value of SBO irradiated with 2.5 KGY was the lowest. Also the peroxide Values of SBO treated with 5.0 KGY, 10.0 KGY were very lower than that of non-irradiation. Conjugated Diene Value of SBO was almost unchanged according to the ${\gamma}$-level and heating time. 3. When the methyl linoleate was irradiated with the ${\gamma}$-ray, the Trans Fatty Acid was little produced. In case of SBO with non-irradiation, the trans C18:1 was occured about 6.5~7.9%, but trans C18:2 and C18:3 were not shown, while SBO irradiated with the ${\gamma}$-ray 2.5, 5.0, 10.0 KGY, trans C18:3 and C18:2 amount in SBO were increased according to heating time, but trans C18:3 was little occured. As these results, the effects of the ${\gamma}$-ray irradiation to oil containing food were to cut down the energy for food storage and to increase oxdative stability during storge. And also it was shown to be the best that 10.0 KGY of the ${\gamma}$-ray irradiation would be applied to soybean.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.411-411
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• 2009

Low level laser therapy has various therapy effects. This paper performed the basic study for developing the Low Level Laser Therapy Equipment for medical treatment. The apparatus has been fabricated using the laser diode and microprocessor unit. This equipment was fabricated using a micro-controller and a laser diode, and designed to enable us to control light irradiation time, frequency and so on. In this study, the designed device was used to find out how infrared laser diode affected the collagen formation. For in-vivo test, a round wound 1cm in diameter was cut from the test animal whose epidermal and dermal layers were removed. Test animals were relieved for 24 hours after wounds had been excised and then the infrared laser irradiation group was given irradiation therapy over 9 days one 20 min per day. As a result, More collagenosis occurred in the order of infrared laser irradiation and non-irradiation group. Collagenosis is closely related to wound repair and it was found that infrared laser irradiation groups had more collagenosis and was quicker to recover from wound than non-irradiation group.

• Transactions on Electrical and Electronic Materials
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• v.14 no.4
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• pp.208-210
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• 2013

ZnO films were deposited on glass substrates by radio frequency (RF) magnetron sputtering and exposed to intense electron beam irradiation to investigate the effects of electron irradiation on the properties of the films. Although all of the films had ZnO (002) textured structure regardless of electron irradiation, the grain sizes of the films decreased with electron irradiation. Surface roughness also depended on electron irradiation. The surface roughness varied between 2.3 and 1.6 nm, depending on the irradiation energy. Based on photoluminescence (PL) characterization, the most intense UV emission was observed from ZnO films irradiated at 900 eV. Since the intensity of UV emission is dependent upon the stoichiometric of ZnO films, we conclude that 900 eV was the optimum electron irradiation energy to achieve the best stoichiometric of ZnO films in this study.

• Proceedings of the KIEE Conference
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• 2009.04a
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• pp.174-176
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• 2009

This paper aims to investigate generation conditions necessary for the most efficient generation by measuring electricity power under various irradiation conditions, since the photovoltaic generation system has high costs and low efficiency. This thesis aims to investigate generation conditions necessary for the most efficient generation by measuring electricity power under various irradiation conditions, since the photovoltaic generation system has high costs and low efficiency. Although the generation power increased with the irradiation, the former did not vary directly as the latter. This meant that the variation of the generation power was concerned in the temperature of a module, the ambient temperature, and the directions of irradiation as well as the irradiation. As for the monthly accumulated irradiation and monthly accumulated power, the maximum irradiation and generation power were observed in May and October and the irradiation, the power and the accumulated generation power were all the highest in spring, followed by fall, summer and winter.