• Macromolecular Research
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• v.9 no.2
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• pp.92-99
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• 2001

Silica-filled rubber compounds have slower cure characteristics than carbon black-filled ones due to the adsorption of curatives on the silica surface. Fatty acid was used as a cure activator along with zinc oxide in a sulfur cure system. Poly(ethylene glycol), PEG, was used in silica-filled rubber compounds to prevent adsorption of the curatives on the silica surface. In this study, influence of the size of fatty acid and PEG on properties of silica-filled NR compounds was investigated. It was found that the size of fatty acid and PEG affected the curt: characteristics and physical properties. The cure rate becomes faster as the PEG size increases. By increasing the size of fatty acid or PEG, the delta torque of the compound decreases while the Mooney viscosity increases. The modulus of the vulcanizate decreases with increasing the molecular weight of fatty acid or PEG. The experimental results were explained by the filler dispersion and by the prevention of the curative-adsorption on the silica surface.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.548-551
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• 1999

The cure characteristics of metal particle filled DGEBA/MDA/SN/ zeolite epoxy resin composite system for EMI shielding were investigated by dynamic DSC run method and FT-lR spectroscopy. As the heating rate increased, the peak temperature on dynamic DSC curve increased because of the rapid cure reaction. From the straight line of the Kissinger plot, the curing reaction activation energy and pre-exponential factor could be obtained. As the post-curing time at 15$0^{\circ}C$ increased, the glass increased the glass transition temperature or the thermal stability increased. When the post curing time is too long, the system filled with metallic Al particle can be thermally oxidized by the catalytic reaction of metal filler and the thermal stability of the composite for the EMI shielding application may be decreased.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.32 no.4
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• pp.13-28
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• 2019

Objectives : The purpose of this study is to report the effectiveness of Korean medical treatment on 222 patients with alopecia areata. Methods : The subjects of this study were 222 patients who had received Korean medical treatment among the patients who visited the Balmer's Korean Medicine Clinic from January 1, 2016 to December 31, 2017. The extent of the alopecia areata was measured every month to determine the improvement. We analyzed the relationship between the types of alopecia areata, the extent of hair loss, duration of illness, age at first visit, and the treatment of alopecia areata. Results : 1. There were 100 males(45.0%) and 122 females(55.0%). The mean age of patients was 35.3 years old. 2. Of the 222 patients, 142(64%) were "cured". 31(14%) showed "good", 21(9.5%) showed "fair", 28(12.6%) showed "poor" improvement. 3. According to clinical records, of the 64 patients with alopecia areata(AA), 48(75.0%) were cured. Of the 100 patients with alopecia areata multiplex(AAM), 68 patients (68.0%), 12(50.0%) out of 24 patients with ophiasis, 5(55.6%) out of 9 with alopecia semi-totalis(AST), 3(50.0%) out of 6 patients with alopecia totalis(AT), 6(31.6%) out of 19 patients with alopecia universalis(AU) were cured. 4. Patients with the wider hair loss extent and with more severe type of alopecia areata required longer treatment period to cure, and the cure rate was lowered(p<0.05). 5. The shorter duration of the disease was related to the higher cure rate(p<0.05). If the treatment was started after six months of the duration, the cure rate was lowered. Therefore, beginning treatment within six months of the onset is recommended. 6. The period until terminal hair showed was 1.5 months for AA, 1.7 months for AAM, 1.6 months for ophiasis, 1.9 months for AST, 2.3 months for AT, 3.2 months for AU. 7. The treatment period to cure was 4.9 months for AA, 7.3 months for AAM, 7.7 months for ophiasis, 6.8 months for AST, 7.7 months for AT, 16.3 months for AU. 8. The major prognostic factors were extent and type of alopecia, duration of the disease and relapse. Conclusions : We analyzed the effectiveness of Korean medical treatment through cure rate according to the prognostic factors. This study will provide useful data for the treatment of alopecia areata.

• Journal of Haehwa Medicine
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• v.19 no.2
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• pp.57-64
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• 2011

Parkinson's disease is a degenerative disease of a cranial nerve and has a main symptoms of irregular movement of muscle, stiffening, trembling which occurred by about 1% of population in the age of over 65. Moreover, the and prevalence rate and attack rate are soaring according to increase of elderly population. However, allopathy and surgery were done through dopamine and anticholinergic medicine for treatment but it developed a lot of complications due to medicine and progress since it makes slow progress or can't stop the treatment. Hereupon, I report that there is a case on one of the patients Young Jin Oriental Medical Clinic. The patient who is in state of treatment termination who doesn't need any further remedy and no worsening of symptoms after conduction of therapies of dialectic and 5 upright life cure regulations. 5 upright life cure regulations means five practive way for improvement of nature healing power. Upon undertaking the 5 upright life cure regulations, there were found significant results in such tests as Unified Parkinson Disease Rating Scale (UPDRS), Hoehn & Yahr Staging Scale, and Activity of Daily Living (ADL), and the ingestion of Benztropine 1mg and Requip 0.25mg was decreased from 3 times to 0 times. The study offers objective clinical data on Oriental Medicine treatment for Parkinson's disease which is one of representative neuro-degenerative diseases and thus broadens the application range of Oriental Medical treatment and presents the fundamental data on the clinical research on Parkinson's disease by adopting evidence-based medicine (EBM).

• Proceedings of the Korean Society For Composite Materials Conference
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• 2002.10a
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• pp.265-268
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• 2002

In this work, the blend system of epoxy and PMR-15 polyimide is investigated in terms of the cure behaviors and thermal stabilities. The cure behaviors are studied in DSC measurements and thermal stabilities are also carried out by TGA analysis. DDM (4, 4'-diamino diphenyl methane) is used as curing agent for EP and the content of PMR-15 is varied within 0, 5, 10, 35, and 20 phr to neat EP. As a result, the cure activation energy ($E_a$) is increased at 10 phr of PMR-15, compared with that of neat EP. From the TGA results of EP/PMR-15 blend system, the thermal stabilities based in the initial decomposed temperature (IDT) and integral procedural decomposition temperature (IPDT) are increased with increasing the PMR-15 content. The fracture toughness, measured in the context of critical stress intensity factor ($K_{IC}$) and critical strain energy release rate ($G_{IC}$), shows a similar behavior with $E_a$. This result is probably due to the crosslinking developed by the interactions between intermolecules in the polymer chains.

• The Korean Journal of Applied Statistics
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• v.17 no.2
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• pp.253-267
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• 2004

In some clinical trials, one may see that a significant fraction of patients are cured and their original disease does not recur even after termination of treatment and pro-longed follow-up. This situation occurs frequently in pediatric cancer trials where there are excellent therapeutic results. In such cases, interest concentrated on the difference of cure rates rather than other types of differences in failure distributions. Various authors have investigated the parametric and nonparametric methods for testing the difference of cure rates. In this study, we compare by simulation the power and size of a parametric test and five nonparametric tests in a various range of the alternatives, censoring rates and cure rates. Our objectives are to determine if any test was preferable on the basis of size and power in various situation, and to investigate the effect of the model misspecification.

• Korean Journal of Materials Research
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• v.8 no.9
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• pp.797-801
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• 1998

The cure kinetics for diglycidyl ether of bisphenol A(DGEBA)/4, 4'-methylene dianiline(MDA) system with or without lOphr of phenyl glycidyl ether(PGE)-acetamide(AcAm) was studied by autocatalytic cure expression. On the dynamic DSC curves, the exothermic peak temperature and the onset temperature of reaction decreased with the addition of PGE-AcAm. Regardless of the addition of PGE-AcAm, the shape of the conversion curve showed sigmoid, and this meant that DGEBA/MDA and DGEBA/MDA/PGE-AcAm systems followed autocatalytic cure reaction. When PGE-AcAm was added to DGEBA/MDA system, the cure rate increased about 1.2~1.4 times due to the catalytic role of hydroxyl groups in PGE-AcAm.

• Korean Journal of Materials Research
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• v.9 no.5
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• pp.467-472
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• 1999

The isothermal cure behavior of diglycidyl ether of bisphenol A(DGEBA) 4,4'-methylene dianiline(MDA) system with various contents of neopentyl glycol(NPG) has been analyzed by differential scanning calorimetry(DSC). TO increase the cure rate of DGEBA/MDA system, NPG was introduced as an accelerator. Regardless of the NPG content, the shape of the conversion curves showed sigmoid indication that DGEBA/MDA/NPG system followed autocatalytic cure reaction. The cure reaction of DGEBA/MDA system increased with the increment of NPG content and it was due to the catalytic role of hydroxyl groups of NPG.

• Macromolecular Research
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• v.17 no.2
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• pp.121-127
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• 2009

The cure kinetics of the epoxy-layered, silicate nanocomposites were studied by differential scanning calorimetry under isothermal and dynamic conditions. The materials used in this study were o-cresol novolac epoxy resin and phenol novolac hardener, with organically modified layered silicates. Various kinetic parameters, including the reaction order, activation energy, and kinetic rate constants, were investigated, and the storage stability of the epoxy-layered silicate nanocomposites was measured. To synthesize the epoxy-layered silicate nanocomposites, the phenolic hardener underwent pre-intercalation by layered silicate. From the cure kinetics analyses, the organically modified layered silicate decreased the activation energy during cure reaction in the epoxy/phenolic hardener system. In addition, the storage stability of the nanocomposite with the pre-intercalated phenolic hardener was significantly increased compared to that of the nanocomposite with direct mixing of epoxy, phenolic hardener, and layered silicate. This was due to the protective effect of the reaction between onium ions and epoxide groups.

• Design & Manufacturing
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• v.17 no.1
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• pp.1-5
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• 2023

In multi-material injection molding, since two or more materials with different process conditions are used, it is essential to maximize process efficiency by operating the cooling or heating system to a minimum. In this study, Liquid silicone rubber (LSR) that can be cured at a low temperature suitable for the multi-material injection molding was selected and the cure behavior according to the process conditions was analyzed through differential scanning calorimetry (DSC). Dynamic measurement results of DSC with different heating rate were obtained, and through this, the total heat of reaction when the LSR was completely cured was calculated. Isothermal measurement results of DSC were derived for 60 minutes at each temperature from 80 ℃ to 110 ℃ at 10 ℃ intervals, and the final degree of cure at each temperature was calculated based on the total heat of reaction identified from the Dynamic DSC measurement results. As the result, it was found that when the temperature is lowered, the curing start time and the time required for the curing reaction increase, but at a temperature of 90 ℃ or higher, LSR can secure a degree of cure of 80% or more. However, at 80 ℃., it was found that not only had a relatively low degree of curing of about 60%, but also significantly increased the curing start time. In addition, in the case of 110 ℃, the parameters were derived from experimental result using the Kamal kinetic model.