• Title/Summary/Keyword: Dose modification

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Preferential face coating of knitted PET fabrics via UV curing for water- and oil-repellent finish (자외선 경화에 의한 PET 니트직물의 편면 발수발유 가공)

  • Jeong, Yong-Kyun;Jeong, Yongjin;Jang, Jinho
    • Textile Coloration and Finishing
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    • v.17 no.6 s.85
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    • pp.27-35
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    • 2005
  • Conventional pad- dry-cure(thermo-fixation) process usually produces functional performance on both sides of a fabric. UV curing technique was applied to impart water- and oil-repellent finish effective only on the face of a PET knitted fabric. The preferential one-side coating, by virtue of the limited penetration of UV light, was achieved by W curing after padding of a fluorocarbon agent without special coating or printing equipments. The difference in the functional property of face and back sides was examined by measuring water and oil repellency at each side of the treated fabric. The influence of pre/post-irradiation dose and agent concentration on the performance of the finished fabrics were investigated. While increase in both resin concentration and post-irradiation did not have significant effect on the finish, UV pre-irradiation of PET fabrics caused remarkable influence presumably due to appropriate surface modification of PET fabrics required for facile wetting of the resin. The dimensional stability and color change of the UV cured fabrics measured by FAST and reflectance spectrophotometry showed significantly decreased color difference and increased percent extension compared with the samples pre-irradiated without agent application.

Surface Modification of F-MgO by High Energy Electron-beam (높은 에너지의 전자빔을 이용한 F-MgO의 표면 개질)

  • Kim, Kwang-Dae;Tai, Wei Sheng;Luo, Yuan;Seo, Hyun Ook;Lee, Byung Cheol;Yang, Ki Ho;Park, Ok Kyung;Kim, Young Dok
    • Journal of Radiation Industry
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    • v.3 no.1
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    • pp.1-5
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    • 2009
  • The variation of MgO surfaces, in which fluorine was contained (F-MgO), by high energy electron-beam (EB) was studied using X-ray photoelectron spectroscopy (XPS). Fluorine on the MgO surface was eliminated by EB treatment with the consequence that the electronic structures of Mg, O and C were varied. Moreover, as a result of oxidation of carbon species on the surface by high dose EB treatment (90 kGy), the concentration of carbonate and carboxyl species on the surface was increased. In this experiment, it was confirmed that the structure of oxidized metal surface can be adjusted by varying conditions of EB treatment (energy and dose). This result implies that EB can be applied for developing new catalysts.

Surface Graft Polymerization of Poly(ethylene glycol) Methacrylate onto Kenaf Pulp using Gamma-ray Irradiation (감마선을 이용한 케나프 펄프 표면의 Poly(ethylene glycol) Methacrylate 그라프트 중합반응)

  • Oh, Doori;Jeun, Joon Pyo;Kang, Phil Hyun
    • Journal of Radiation Industry
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    • v.6 no.3
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    • pp.251-255
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    • 2012
  • Pulp is typically used for paper industry to manufacturing various types of papers. However simply chemical modification makes enable the pulp to a wide range of application in various industrial fields. To bring the polymerization the gamma ray irradiated on the mixture of kenaf and PEGMA in various dose ranges from 20 to 60 kGy. As a results, the graft degree of 20.0% was obtained from 475 g of gamma ray irradiated pulp and PEGMA. After the polymerization, the chemical structure and morphology of the surfaces were examined by Fourier transform infrared spectroscopy, thermogravimetric analysis, and scanning electron microscope. Chemical structure of grafted pulp has significantly growth in carbonyl content with increasing the radiation dose. Also surface morphology was distinctly changed with decreased the degree of roughness and increasing the diameter. These results were explained gamma ray irradiation improve performance of graft polymerization efficiency.

Tranquilizer-like Effects of Sanjoinine A: Possible GABA/Benzodiazepine Receptors Complex Involvement

  • Ma, Yu-An;Eun, Jae-Soon;Oh, Ki-Wan
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 2008.04a
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    • pp.119-142
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    • 2008
  • Zizyphi Spinosi Semen (ZSS) has been widely used for the treatment of anxiety and insomnia in Korea and China. This experiment was performed to know whether sanjoinine A, one of major alkaloid compounds of ZSS has anxiolytic and hypnotic effects through the GABAergic systems. Our results showed that administration of sanjoinine A increased open arm entries and spent time in open arm in the elevated plus-maze and increased head dips in hole board test. Different from traditional anxiolytic, diazepam, sanjoinine A itself did not decrease locomotor activity and strength level in mice. Furthermore, Sanjoinine A (0.5-2.0 mg/kg) prolonged sleeping time and reduced sleeping latency induced by pentobarbital in a dose-dependent manner similar to muscimol, a $GABA_A$ receptor agonist. Sanjoinine A (0.25-1.0 mg/kg) also increased sleeping rate and sleeping time in the combined administration at the sub-hypnotic dose of pentobarbital and showed synergic effects with muscimol in potentiating sleeping onset and enhancing sleeping time induced by pentobarbital. However, sanjoinine A itself did not induce sleeping at the higher dose. In addition, both of sanjoinine A and pentobarbital increased chloride influx in primary cultured cerebellar granule cells. Sanjoinine A decreased the $GABA_A$ receptor ${\alpha}$-subunit expression and increased ${\gamma}$-subunit expression, and had no effects on abundance of ${\beta}$-subunit in primary cultured cerebellar granule cells, showing different expression of subunits from pentobarbital. In conclusion, sanjoinine A shows anxiolytic-like effects and augments pentabarbital-induced sleeping behaviors through the modification of GABAergic systems. [This work was supported by the Korea Research Foundation Grant funded by the Korean Government (MOEHRD) (The Regional Research Universities Program/Center for Healthcare Technology Development)].

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Modification of Trunk Thickness of MIRD phantom Based on the Comparison of Organ Doses with Voxel Phantom (체적소팬텀과의 장기선량 비교를 통한 MIRD팬텀 몸통두께 수정)

  • Lee, Choon-Sik;Park, Sang-Hyun;Lee, Jai-Ki
    • Journal of Radiation Protection and Research
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    • v.28 no.3
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    • pp.199-206
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    • 2003
  • Because the MIRD phantom, the representative mathematical phantom was developed for the calculation of internal radiation dose, and simulated by the simplified mathematical equations for rapid computation, the appropriateness of application to external dose calculation and the closeness to real human body should be justified. This study was intended to modify the MIRD phantom according to the comparison of the organ absorbed doses in the two phantoms exposed to monoenergetic broad parallel photon beams of the energy between 0.05 MeV and 10 MeV. The organ absorbed doses of the MIRD phantom and the Zubal yokel phantom were calculated for AP and PA geometries by MCNP4C, general-purpose Monte Carlo code. The MIRD phantom received higher doses than the Zubal phantom for both AP and PA geometries. Effective dose in PA geometry for 0.05 MeV photon beams showed the difference up to 50%. Anatomical axial views of the two phantoms revealed the thinner trunk thickness of the MIRD phantom than that of the Zubal phantom. To find out the optimal thickness of trunk, the difference of effective doses for 0.5 MeV photon beams for various trunk thickness of the MIRD phantom from 20 cm to 36 cm were compared. The optimal thunk thickness, 24 cm and 28 cm for AP and PA geometries, respectively, showed the minimum difference of effective doses between the two phantoms. The trunk model of the MIRD phantom was modified and the organ doses were recalculated using the modified MIRD phantom. The differences of effective dose for AP and PA geometries reduced to 7.3% and the overestimation of organ doses decreased, too. Because MIRD-type phantoms are easier to be adopted in Monte Carlo calculations and to standardize, the modifications of the MIRD phantom allow us to hold the advantage of MIRD-type phantoms over a voxel phantom and alleviate the anatomical difference and consequent disagreement in dose calculation.

Study of Patient's Position to Reduce Late Complications in High Dose Rate Intracavitary Radiation of the Uterine Cervix Cancer (자궁경부암의 고선량율 강내 방사선치료 시 부작용을 줄이기 위한 적정 치료 자세의 연구)

  • Yun, Hyong-Geun;Shin, Kyo-Chul
    • Radiation Oncology Journal
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    • v.16 no.4
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    • pp.477-483
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    • 1998
  • Purpose : Radiation proctitis and radiation cystitis are frequent and problematic late complications in patients treated with radiation for the uterine cervix cancer. Authors tried to find out the better patient's position in high dose rate intracavitary radiation to reduce the radiation dose of bladder and rectum. Materials and Methods : In 13 patients, Foley Catheters were inserted to patient's bladder and rectum and were ballooned with radioopaque dye. After insertion of a tandem and two ovoids, semi-orthogonal anteroposterior and lateral films were taken in both lithotomy and supine position. The rectal point and bladder point were defined according to the criteria recommended in the ICRU Report 38 with modification. Using these films, all patients' bladder and rectal dose were calculated in both positions (the radiation dose of A point was set to 400 cGy). And also, the distance of bladder and rectum from uterine cervical os was calculated in both positions. Results : The average radiation dose of rectum was 240.7 cGy in lithotomy position and 278.3 cGy in supine position, and the average radiation dose of bladder was 303.5 cGy in lithotomy position and 255.8 cGy in supine position. After the paired t-test, the radiation dose of rectum in lithotomy position was marginally significantly lower than that in supine position, while the radiation dose of bladder in lithotomy position was significantly higher than that in supine position. On the other hand, the average distance between rectum and cervical os was 35.2 mm in lithotomy position and 32.3 mm in supine position. and the average distance between bladder and cervical os was 30.4 mm in lithotomy position and 34.0 mm in supine position. After the paired t-test. the distance between rectum and cervical os in lithotomy position was significantly longer than that in supine position, while the distance between bladder and cervical os in lithotomy position was significantly shorter than that in supine position. Conclusion : The radiation dose of bladder can be reduced in supine position and the radiation dose of rectum can be reduced in lithotomy position, so we can choose appropriate position in each patient.

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Structural Modification of Nanodiamond Induced by Ion Irradiation

  • Seok, Jae-Gwon;Im, Won-Cheol;Chae, Geun-Hwa;Song, Jong-Han;Lee, Jae-Yong
    • Proceedings of the Korean Vacuum Society Conference
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    • 2014.02a
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    • pp.195.2-195.2
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    • 2014
  • Nanodiamond (ND) is composed of inner diamond core and outer graphite shell. The size of ND used in this study was about 5 nm. The ND solution was dropped on silicon substrate and dried in air. Dried ND sample was purified by using annealing method in air. Then, 40 keV Fe ion was irradiated into the sample. The dose was varied from $1{\times}10^{14}$ to $1{\times}10^{16}ions/cm^2$. The post annealing was performed at 1073 K in the vacuum to recover diamond structure. The annealing at 873 K in air was performed to remove the outer graphite shell. The structure of ND was confirmed by X-ray diffraction (XRD) and Raman spectroscopy. We will present the detailed data and results in the conference.

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Antioxidative Effect of Silybin Purified from Silybum marianum on modification of Human Low Density Lipoprotein (엉겅퀴에서 분리정제한 silybin의 Human Low Density Lipoprotein 수식에 대한 항산화 효과)

  • Ryu, Beung-Ho;Kim, Hee-Suck;Lee, Baek-Cheon;Lee, Hong-Su
    • Journal of Life Science
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    • v.8 no.4
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    • pp.353-359
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    • 1998
  • This study was initiated to antioxidant activity of silybin on oxidation of human low density lipoproteins(LDL). Siltbin was extracted from Silybum marianum by the combination of fractionation and it was futher purified by silica gel column chromatography, and isolated active substances were identified silybin by IR, NMR and GC-MS. siltbin inhibited the ozidation of human low density lipoprotein(LDL) mediated by 5$^{\mu}$m CU $^{2+}$ ion in a dose dependent manner. LDL oxidation by congugated dines formation was completely inhibited by silybin at a concentration of 5$^{\mu}$M. The results provide a possibility that silybin might protect LDL against oxidation in atherosclerotic lessions.

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Study of the Photo-alignment Technique through the Surface Modification

  • Song, Dong-Mee;Shin, Dong-Myung
    • 한국정보디스플레이학회:학술대회논문집
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    • 2000.01a
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    • pp.197-198
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    • 2000
  • A surface-assisted photo-control of the liquid crystal (LC) alignment has been achieved by modifying the topmost surface of the polyimide film with photo-reactive molecules. Recently, photo-alignment technique using a thin film of poly(vinyl cinnamates) have been reported. However their commercial potentiality is limited by their low thermal stability. To enhance thermal stability, we synthesized the chalcone derivatives as the photo-reactive molecules and introduced the materials on the surface-modified polyimide film.. We identified that the photo-chemical reaction of the chalcone derivatives occur in few minutes with irradiation of UV light. The photo-alignment characteristics of the modified polyimide films treated by polarized UV light and their LC cells are investigated as a function of exposure dose.

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Development of RADCON and Establishments of Its Related System

  • Kim, Kuk-Ki;Lee, Kun-Jai;Park, Won jong
    • Proceedings of the Korean Nuclear Society Conference
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    • 1996.05d
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    • pp.51-56
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    • 1996
  • In a NNP (Nuclear Power Plant) severe accident, radionuclides are dispersed into the air. The official regulatory institute, KINS (Korea Institute of Nuclear Safety), has been authorized and developing Computerized technical Advisory system for the Radiological Emergency preparedness (CARE). In this paper, in line with the CARE system, we presented the result of a modularized intermediate-level emergency dose assessment computer code. The RADCON (RADiological CONsequence analysis) version 3.0, which is operable on PC, is developed for simulating emergency situation by considering continuous washout phenomena, and provide a function of effective emergency planning. The source files are coded by using C language in order to increase the compatibility with the other computer system and modularized to adjust the functions and characteristics of each module fer easy understanding and further modification.

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