• Journal of radiological science and technology
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• v.40 no.4
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• pp.627-632
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• 2017

In order to design a dual-head gantry radiotherapy system, the single head of LINAC was modeled using GATE as a preliminary study. The LINAC head was designed with VARIAN manufacturer's information. 6 MV photons were generated from the head and the photons w irradiated to a water phantom for beam evaluation. GATE simulation was segmented by two stages, the one was to generate X-ray spectrum and the other one was for irradiation X-ray to the water phantom. The quantitative results were described in Percentage depth dose and beam profile. Two field size conditions were employed as $5{\times}5$ and $10{\times}10cm^2$. After beam quality was verified, dual heads gantry radiotherapy system were simulated and they was compared to the single head of LINAC system in terms of dose deposition with in the phantom. The simulated LINAC head showed acceptable beam quality result for radiotherapy. The efficiency was calculated that deposited dose from dual heads was divided by the dose from single head. At all conditions, dual heads showed higher treatment efficiency. Efficiency was increased about 40 to 60%. Form the result, The dual head gantry system of new LINAC system will contribute to the practical radiotherapy of tumor and to reduce treatment time.

• Proceedings of the SAREK Conference
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• 2007.11a
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• pp.310-315
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• 2007

The FTL has been developed to be able to irradiate test fuels at the irradiation hole(IR1 hole) by considering its utility and user's irradiation requirements. FTL consists of In-Pile Test Section (IPS) and Out-of-Pile System (OPS). Test condition in IPS such as pressure, temperature and the water quality, can be controlled by OPS. For safety assurance IPS is designed to have dual stainless steel pressure vessel and OPS is composed of main cooling water system, emergency cooling water system, LMP(letdown, make-up, purification) system, etc. FTL Conceptual design was set up in 2001, basic design had completed including a design requirement, basic piping & instrument diagram (P&ID), and the detail design in 2004. In 2005, the development team carried out purchase and manufacture hardware and make a contract for construction work. FTL construction work began on August, 2006 and ended on March, 2007. After FTL development which is expected to be finished by 2008, FTL will be used for the irradiation test of the new PWR-type fuel and can maximize the usage of HANARO.

• Radiation Oncology Journal
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• v.16 no.3
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• pp.337-345
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• 1998

Purpose : To obtain the uniform dose at limited depth to entire surface of the body, the dose characteristics of degraded electron beam of the large target-skin distance and the dose distribution of the six-dual electron fields were investigated Materials and Method : The experimental dose distributions included the depth dose curve, spatial dose and attenuated electron beam were determined with 300 cm of target-skin distance (TSD) and full collimator size (35*35 $cm^2$ on TSD 100 cm) in 4 MeV electron beam energy. Actual collimated field size of 105 cm * 105 cm at the distance of 300 cm could include entire hemibody. A patient was standing on step board with hands up and holding the pole to stabilize his/her positions for the six-dual fields technique. As a scatter-degrader, 0.5 cm of acrylic plate was inserted at 20 cm from the body surface on the electron beam path to induce ray scattering and to increase the skin dose. Results : The full width at half maximum(FWHM) of dose profile was 130 cm in large field of 105*105 $cm^2$ The width of $100\pm10\%$ of the resultant dose from two adjacent fields which were separated at 25 cm from field edge for obtaining the dose unifomity was extended to 186 cm. The depth of maximum dose lies at 5 mm and the 80$\%$ depth dose lies between 7 and 8 mm for the degraded electron beam by using the 0.5 cm thickness of acrylic absorber. Total skin electron beam irradiation (TSEBI) was carried out using the six dual fields has been developed at Stanford University. The dose distribution in TSEBI showed relatively uniform around the flat region of skin except the protruding and deeply curvatured portion of the body, which showed excess of dose at the former and less dose at the latter. Conclusion : The percent depth dose, profile curves and superimposed dose distribution were investigated using the degraded electron beam through the beam absorber. The dose distribution obtained by experiments of TSEBI showed within$\pm10\%$ difference except the protruding area of skin which needs a shield and deeply curvatured region of skin which needs boosting dose.

• Bulletin of the Korean Chemical Society
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• v.34 no.1
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• pp.154-158
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• 2013

Development of dual functional liposome has been studied for cancer theragnostics. Therefore, we focused on ultrasound-sensitive liposomes with doxorubicin (DOX) and gadolinium (Gd) as a theragnostic carrier having a potential for cancer therapy and diagnosis. In this study, Gd(III)-DOTA-modified sonosensitive liposomes (GL) was developed using chemically synthesized Gd(III)-DOTA-DPPE lipid. Sonosensitivity of GL to 1 MHz ultrasound induced 25% of DOX release. The relaxivities ($r_1$) of GL were $7.33-10.34\;mM^{-1}s^{-1}$, which was higher than that of MR-bester$^{(R)}$. Intracellular delivery of DOX from GL by ultrasound irradiation was evaluated according to ultrasound intensity, resulting in increase of uptake of DOX released from ultrasound-triggered GLs compared to GL3 or Doxil$^{(R)}$ without ultrasound. Taken together, this study shows that the paramagnetic and sonosensitive liposomes, GL, is a novel and highly effective delivery system for drug with the potential for broad applications in human disease.

• Textile Coloration and Finishing
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• v.34 no.4
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• pp.217-223
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• 2022

Flame-retardant finished silk fabrics could release carcinogenic formaldehyde resulting from the conventional finishing agents. New water-soluble cyclophosphazene derivative can be used as a formaldehyde-free flame retardant for the silk protein. Dichloro tetrakis{N-[3-dimethylamino)propyl]methacrylamido}cyclophosphazene(DCTDCP) can be cured by heat or UV irradiation as a durable flame retardant for the silk fabrics. Treatment conditions were optimized including curing temperature and time, finishing formulations, and UV energy. At the 30% DCTDCP application, peak HRR and THR decreased by 42.6% and 49.6% respectively compared to the pristine silk fabrics. Also char residue increased up to 48% from 11% indicating solid-phase retarding mechanism. The flame-retardant silk fabrics showed a LOI of 31.1 and the washed sample maintained a LOI of 26.8 even after ten laundering cycles.

• Progress in Medical Physics
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• v.20 no.3
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• pp.152-158
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• 2009

Total Skin Electron Beam Therapy (TSEBT) of linear accelerator has become use so as to be useful, 2~9 MeV of energy territories came to be used with mycosis fungoides and cutaneous lymphomas in the superficial lesion treatment which covers the major portion of the body. I treat a patient to Stanford technique in this study, and it is $60^{\circ}$ around the patients whom Stanford technique irradiated electronic beam to a linear accelerator in horizontal directions and there is a way a standard of TSEBT treat it to six located field (anterior, posterior, and four obliques) becoming. An each field does horizontally it and consist to beam of the two component which fitted the center to a suitable angle. a patient treats it to three dual field a day in order to make short treatment time. when a first day, we treat one dual field at anterior position and two dual field at posterior position. when the second day, treat one dual field at posterior position and two dual field at anterior position. Therefore, six dual field is finished in perfect periodic two days. we made cylindrical acrylic phantom, and I inserted a dosimeter film between phantom. in order to measure a dose distribution calculation before treat a patient, and a patient checked it in six field directions that got from a treatment. It is after that thermoluminescent dosimetry (TLD) as it uses Rando phantom and then measurement dose distribution in six field directions after attaching at chest, the right and left flank, a back after irradiation.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.23 no.1
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• pp.27-44
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• 1993

This study was performed to investigate the changes of mandibular condyle by low calcium diet and the effects of irradiation on the bone in osteoporotic state. In order to carry out this experiment, 80 seven-week old Sprague-Dawley strain rats weighing about 150 gm were selected and equally divided into one experimental group of 40 rats and one control group with the remainder. The experimental group and the control group were then subdivided into two group and exposed to irradiation. The two irradiation groups received a single dose of 20 Gy on the jaw area only and irradiated with a cobalt-60 teletherapy unit. The rats in the control and experimental groups were serially terminated by fours on the 3rd, the 7th, the 14th, and the 21st day after irradiation. After termination, both sides of the dead rats mandibular condyle were removed and fixed with 10% neutral formalin. The bone mineral density of mandibular condyle was measured by use of dual energy X-ray bone densitometer(model DDX-alpha, Lunn Corp., U. S. A.). The mandibular condyle was radiographed with Hitex HA-80(Hitex Co., Japan). Thereafter, the obtained radiographs were observed, and the mandibular condyle was further decalcified and embedded in paraffin as the general method. The specimen sectioned and stained with hematoxylin-eosin, PAS and Rabbit Anti-Human Tumor Necrosis Factor-a observed by a light microscope. The obtained results were as follows: 1. In the non-irradiated group with the low calcium diet, the bone mineral density of the condyle was markedly decreased after 14 days, and decrease the number of trabeculae of the condyle and resorption of the calcified cartilaginous zone were observed after 3 days. On microscopic observations, the number nd size of trabeculae were decreased after 7 days of experiment. 2. In the irradiated group with the low calcium diet, the bone mineral density of the condyle was markedly decreased after 14 days and resorption of the calcified cartilaginous zone and decrease the number and coarse of the trabeculae of the condyle were observed. These findings were extended rather than in non-irradiated group with low calcium diet. On microscopic observations, many osteoclasts were detected and the number and size of trabeculae were somewhat decreased after 7 days. Also there was degenerative changes of tissues of bone marrow on the 14th day but that condition was restored on the 21st day of experiment. 3. In the irradiated group with normal diet, the bone mineral density of the condyle was somewhat decreased with times and degree of decrease of the number of trabeculae was somewhat larger than in the non-irradiated group with normal diet. On microscopic observations, the tissues of bone marrow were atrophic and degenerative changes but that condition was restored on the 21st day of experiment. 4. In immunocytochemical findings, in the irradiated and non-irradiated groups with low calcium diet, negative or partial positive response to TNF was observed, but positive response in the normal diet groups.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.2
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• pp.207-215
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• 2006

This study evaluated the effect of ultrasonic irradiation on reducing membrane fouling for the treatment of chemically treated leachate and biologically treated leachate. The experiments on improvement of membrane flux according to the membrane types(MF and UF) and membrane materials were performed with changing frequency(40 kHz and 120 kHz) and intensity(200 W and 400 W) of ultrasound in ultrasonic membrane separation apparatus which ultrasound can be periodically irradiated. Additionally, the effect of dual frequency ultrasound which 40 kHz md 120 kHz are irradiated simultaneously was evaluated. The improvement of membrane flux by periodical ultrasound irradiation was higher in microfiltration(MF) membrane than in ultrafiltration(UF) membrane. It was sustained more in the MF membrane of polyvinylidene fluoride(PVDF) than in that of polysulfon(PS). Ultrasonic improvement of membrane flux was different depending on the characteristics of target wastewater. It was sustainably maintained without reclogging using dual frequency ultrasound although the improvement of membrane flux was lower.

• Applied Chemistry for Engineering
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• v.23 no.1
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• pp.65-70
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• 2012

Structural changing materials which can induce the physical deformation of materials are interesting research topics with various potential applications. Particularly, light among many driving mechanisms is a non-contact energy source, hence the light-responsive system can be used where non-destructive, local irradiation, and remote control is needed. Here, a mainchain azobenzene polymer is synthesized and its physical and optical properties are observed and compared to that of a polymer having a light-responsive azobenzene moiety on its side chain. Further dispersion onto polyvinylalcohol hydrogel is made and its dual stability and actuation are observed upon UV-visible light irradiation. Extended azobenzene polymer blend films show an anisotropic light-actuation with non-polarized UV light at room temperature. This physical shape change is quite reversible and occurs at lower temperature than that of any other reported systems including liquid crystalline elastomers. It is successfully demonstrated that the simple physical azobenzene/polymer blending has a very good actuation compared to that of LCEs which need an elaborate chemical design and it can be further used in the areas requiring a dimensional shape change.

• Journal of Radiation Industry
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• v.5 no.4
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• pp.371-376
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• 2011

The surface property of the materials used in tissue engineering application has been essential to regulate cellular behaviors by directing their adhesion on the materials. To modulate surface property of the synthetic biodegradable materials, a variety of surface modification techniques have used to introduced surface functional groups or bioactive molecules, recently polydopamine coating method have been introduce as a facile modification method which can be coated on various materials such as polymers, metals, and ceramics regardless of their surface property. However, there are no reports about the degree of polydopamine coating on the materials with different hydrophilicity. In the present study, we prepared acrylic acid grafted nanofibrous meshes using electron-beam irradiation, and then coated meshes with polydopamine. Polydopamine successfully coated on the all meshes, both properties of acrylic acid and polydopamine were detected on the meshes. In addition, the degree of polydopamine deposition on the materials has been altered according to surface hydrophilicity, which was approximately 8-times greater than those on the non-modified materials. In conclusion, dual effect from the acrylic acid grafting and polydopamine may give a chance as a alternative tool in tissue engineering application.