• Title/Summary/Keyword: curable

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Curing Properties of UV-LED Curable Color Coating (UV-LED 경화형 칼라 코팅의 경화특성 연구)

  • Ho, Shin-Chan;Kim, Jong-Gu;Hong, Jin-Who;Ahn, Tae-Jung;Kim, Hyun-Kyoung
    • Journal of Adhesion and Interface
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    • v.13 no.1
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    • pp.31-37
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    • 2012
  • In this study, we investigated the curing properties of UV-LED curable color coating. Specially, the effects of UV-LED wavelength (365, 395, and 405 nm), inert gas, the concentration of photosensitizer, and dual curing on the curing behavior of UV-LED coating systems were studied. The photopolymerization behaviors and the unreacted acrylate groups at Film-air (FA) interface and Film-substrate (FS) interface were investigated by photo differential scanning calorimetry (Photo-DSC) and Fourier-transform infrared spectroscopy with attenuated total reflection (FT-IR/ATR), respectively. Photo-DSC results showed that the heat flow and the ultimate conversion for coating system cured by 405 nm UV-LED were higher than the corresponding values for coating systems cured by 395 and 365 nm UV-LED. FT-IR/ATR results showed that the UV-LED curing systems improved interior and through curing of the coating film, but significantly are affected by oxygen inhibition at FA-interface. The inert environment such as nitrogen purging and the dual curing improved the surface and interior curing of the coating films.

A Clinicopathologic Analysis of Neck Masses (경부 종괴의 임상 및 병리학적 고찰)

  • Km Jeong-Ho;Oh Sang-Hoon;Kim Sang-Hyo
    • Korean Journal of Head & Neck Oncology
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    • v.13 no.1
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    • pp.51-57
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    • 1997
  • A mass appearing in the anterior or lateral side of neck often can be a diagnostic challenge. Differential diagnosis of the neck mass covers a broad spectrum of diseases and the proper evaluation and management of a neck mass requires an impressive amount of anatomic and pathologic information. Because improper diagnosis and management may convert a potentially curable malignant metastasis into incurable disease, a differential diagnosis must be considered in all patients who present with a neck mass. Authors reviewed 2,148 cases of neck mass who were diagnosed by surgical resection, biopsy or aspiration during the period between October 1982 to December 1993, excluding those with thyroid and parathyroid disease. The evaluated characteristics were age, sex, site of lesion, and pathologic diagnosis. The results were as follows: Of 2,148 cases of neck mass, the overall ratio of benign to malignant tumor was 3 : 1. In 1,603 cases of benign mass lesion, the most common disease was lymphadenitis(non-specific and tuberculosis) showing 53% incidence, the second was salivary gland tumor(13%), and the third was congenital lesion(12%). The minor problems such as lipoma and sebaceous cyst were 21 %. In the age distribution of benign lesion, tuberculous lymphadenitis showed peak incidence in second decade, non-specific lymphadenitis was main disease of childhood, salivary gland tumor was peak in fourth decade, and most of congenital lesions were diagnosed at the age below 15. In 545 malignant tumors, the most common lesion was metastatic cancer to cervical lymph nodes yielding 71 % incidence(head and neck primary 52%, infraclavicular primary 42%, unknown primary 5%), the second common disease was lymphoma(19%), and the third was salivary gland cancer(9%). In the age incidence of malignant tumor, 60% of them developed in the fifth and sixth decade, head and neck primary was more common in the fifth decade than sixth, however lymphoma showed higher incidence in sixth decade. In the analysis of mass location according to lymph node level grouping(I - V), lymphadenitis developed mostly in level V nodes, the next common occurring site was level IV in tuberculous lymphadenitis and level II in non-specific lymphadenitis. The majority of metastatic cancers were found in level IV and III, and common occurring site of lymphoma was in level II and IV. Pathologic diagnosis of neck masses were made by fine needle aspiration cytology 80 cases, incisional biopsy 533 cases, excisional surgery 1,399 cases, and neck dissection 116 cases. For the proper management of neck mass, a proper diagnostic modality should be selected from imaging techniques, cytology, biopsy or neck dissection, with the consideration of patient's age, history and clinical findings. The scapel biopsy could be used freely in the inflammatory disease or inoperable metastatic cancer, but it should be reserved in the curable metastatic cancer or clinically possible malignancy.

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Self-Curable Humidity-Sensitive Polyelectrolytes Attached to the Alumina Substrate for the Humidity Sensor and their Stability in Water (알루미나 기재에 부착된 습도센서용 자기 가교형 감습성 전해질 고분자의 내수성)

  • Han, Dae-Sang;Gong, Myoung-Seon
    • Polymer(Korea)
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    • v.34 no.4
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    • pp.313-320
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    • 2010
  • New cinnamate group-containing copolymers for a self-curable, humidity-sensitive polyelectrolyte and polymeric anchoring agents were prepared by copolymerization of [2-[(methacryloyloxy) ethyl]dimethyl]propyl ammonium bromide(MEPAB), methyl methacrylate(MMA), 3-(trimethoxysilyl) propyl methacrylate(TMSPM) and 2-(cinnamoyloxy)ethyl methacrylate(CEMA). Photocrosslinkable copolymer composed of MEPAB/MMA/TMSPM/CEMA=70/20/0/10 were used for humidity-sensitive membrane, and those of 50/0/20/30 and 0/0/50/50 were used for polymeric anchoring agents. 3- (Triethoxysilyl)propyl cinnamate(TESPC) was also used as a surface-pretreating agent for the comparison of capability of attachment of polyelectrolyte to the electrode surface with polymeric photocurable silanecoupling agents. Pretreatment of the electrode substrate with anchoring agents was performed to form a cinnamate thin film on the electrode through covalent bonds. When the sensors were irradiated with UV light, the anchoring of a polyelectrolyte into the substrate was carried out via the [2$\pi$+2$\pi$] cycloaddition. The resulting sensors using polymeric anchoring agents and TESPC showed water durability with increase of resistance by 60~85%, which is corresponding to the reduction of 2.25~3.15%RH, after soaking in water for 24 h. They showed good hysteresis (-0.2%RH), response time (90 sec) and long-term stability at high temperature and humidity.

Fabrication of the Imaging Lens for Mobile Camera using Embossing Method (엠보싱 공법에 의한 카메라 모듈용 광학렌즈 성형기법에 대한 연구)

  • Lee, C.H.;Jin, Y.S.;Noh, J.E.;Kim, S.H.;Jang, I.C.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2007.05a
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    • pp.79-83
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    • 2007
  • We have developed a compact and cost-effective camera module on the basis of wafer-scale replication technology. A multiple-layered structure of several aspheric lenses in a mobile camera module is first assembled by bonding multiple glass-wafers on which 2-dimensional replica arrays of identical aspheric lenses are UV-embossed, followed by dicing the stacked wafers and packaging them with image sensor chips. We have demonstrated a VGA camera module fabricated by the wafer-scale replication processing with various UV-curable polymers having refractive indices between 1.4 and 1.6, and with three different glass-wafers of which both surfaces are embossed as aspheric lenses having 200 um sag-height and aspheric-coefficients of lens polynomials up to tenth-order. We have found that precise compensation in material shrinkage of the polymer materials is one of the most technical challenges, in order to achieve a higher resolution in wafer-scaled lenses for mobile camera modules.

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Effect of Chemical Structure on the Properties of UV-cured Polyurethane Acrylates Films

  • Kwon, Ji-Yun;Yoo, Hye-Jin;Kim, Han-Do
    • Fibers and Polymers
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    • v.2 no.3
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    • pp.141-147
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    • 2001
  • The effect of compositions of isophorone diisocyanate (IPDl)/4.4'-diphenylmethane diisocyalate (MDI) and polypropylene oxide diol (PPG, $M_w$: 3000)/1,4-butane diol (BD) on the properties of UV-cured polyurethane acrylate films based on 2-hydroxyethyl acrylate (HEA) was examined. UV-curable polyurethane acrylates were formulated from the prepolymer. trimethylol propane triacrylate (TMPTA) as a reactive diluent, and 1-hydroxycyclohexyl ketone (Irgacure 184) as a photoinitiator. Dynamic mechanical thermal properties and elastic properties of UV-cured polyurethane acrylates was fecund to depend on the chemical composition of IPDl/MDl and PPG/BD. As the BD content increased, the tensile storage modulus of all series samples increased significantly. The storage modulus increased in the order of samples A (IPDI based samples)> samples B (IPDI/MDl (7/3 molar ratio) based samples) > samples C (IPDI/MDl (5/5 molar ratio) based samples at the same composition. Two distinct louts modulus peaks for all samples are observed owing to the softs segment glass transition temperature ($T_gh$) and hard segment glass transition temperature ($T_gh$). The difference between $T_gh$, and $T_gh$, (Δ$T_g$) increases in the order of A > B > C at the same composition. In cycle test, the initial onset strain (%) was found to decrease with increasing BD content in PPG/BD and with increasing MDI content in IPDI/MDl.

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Acoustic Property and Hardness of Coatings for Musical Instruments with Various Coating Thicknesses

  • Hwang, Hyeon-Deuk;Lee, Byoung-Hoo;Choi, Jae-Hoon;Kim, Hyun-Joong;Chung, Woo-Yang
    • Journal of the Korean Wood Science and Technology
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    • v.34 no.2
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    • pp.58-67
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    • 2006
  • The relationship between acoustic property and coating hardness of musical instruments was investigated using a sound level meter and a pendulum hardness tester. Urethane topcoat, oil stain, natural oil varnish, and UV-curable epoxy acrylate coatings were applied on four different substrates: Paulownia coreana, Pinus koraiensis, Castanea crenata var. dulcis and Pinus densiflora. The influence of the coating type on the acoustic properties was stronger than that of the substrate. In the case of an oil stain formed with tacky coating layer, the sound pressure level (SPL) and surface hardness decreased with increasing of coating thickness. In the other coatings, SPL decreased and hardness increased as the coating layer thickened. However, SPL began to increase again at coating thickness above $100{\mu}m$.

Prevalence of Trichomoniasis by PCR in Women Attending Health Screening in Korea

  • Kim, Seung-Ryong;Kim, Jung-Hyun;Gu, Na-Yeong;Kim, Yong-Suk;Hong, Yeon-Chul;Ryu, Jae-Sook
    • Parasites, Hosts and Diseases
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    • v.54 no.2
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    • pp.187-190
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    • 2016
  • Trichomoniasis is the most common curable sexually-transmitted infection (STI) worldwide. There are few reports on the prevalence of Trichomonas vaginalis in Korea. The purpose of this study was to examine the prevalence of trichomoniasis by PCR in Guri city, Korea. All adult women who visited Hanyang University Guri Hospital for health screening within the National Health Care Service were invited to participate in the study, and 424 women were enrolled between March and June 2011. PCR was used to detect Trichomonas vaginalis using primers based on a repetitive sequence cloned from T. vaginalis (TV-E650). Fourteen women (3.3%) were found to have T. vaginalis. All were over 50, and they were significantly older on average than the 410 Trichomonas-negative women (mean ages 63.4 vs 55.3 years). It seems that T. vaginalis infection is not rare in women receiving health screening, especially among those over 50.

Fabrication of Patchable Organic Lasing Sheets via Soft Lithography

  • Kim, Ju-Hyung
    • Clean Technology
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    • v.22 no.3
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    • pp.203-207
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    • 2016
  • Here, we report a novel fabrication technique for patchable organic lasing sheet based on non-volatile liquid organic semiconductors and freestanding polymeric film with high flexibility and patchability. For this work, we have fabricated the second-order DFB grating structure, which leads to surface emission, embedded in the freestanding polymeric film. Using an ultra-violet (UV) curable polyurethaneacrylate (PUA) mixture, the periodic DFB grating structure can be easily prepared on the freestanding polymeric film via a simple UV curing process. Due to unsaturated acrylate remained in the PUA mixture after UV curing, the freestanding PUA film provides adhesive properties, which enable mounting of the patchable organic lasing sheet onto non-flat surfaces with conformal contact. To achieve laser actions in the freestanding resonator structure, a composite material of liquid 9-(2-ethylhexyl)carbazole (EHCz) and organic laser dyes was used as the laser medium. Since the degraded active materials can be easily refreshed by a simple injection of the liquid composite, such a non-volatile liquid organic semiconducting medium has degradation-free and recyclable characteristics in addition to other strong advantages including tunable optoelectronic responses, solvent-free processing, and ultimate mechanical flexibility and uniformity. Lasing properties of the patchable organic lasing sheet were also investigated after mounting onto non-flat surfaces, showing a mechanical tunability of laser emission under variable surface curvature. It is anticipated that these results will be applied to the development of various patchable optoelectronic applications for light-emitting displays, sensors and data communications.

Development of Surface-mount-type Crown-shaped Lens for Reducing Glare Effect of Light-emitting Diode Light Source (LED 광원의 눈부심 현상을 감소시키기 위한 표면 실장형 CR 렌즈 개발)

  • Park, Yong Min;Bang, Hyun Chul;Seo, Young Ho;Kim, Byeong Hee
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.23 no.1
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    • pp.64-68
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    • 2014
  • This paper introduces the use of a crown-shaped (CR) lens to effectively diffuse the light from a light-emitting diode (LED) without any loss in the light intensity, in contrast to polymer-bulb-type diffusers. The diffusion lens was designed based on the Snell's law, which describes the physical path of a ray passing through the boundary between different media. CR lenses were fabricated by polydimethylsiloxane (PDMS) casting and UV-embossing processes, which used a pre-designed metal mold and UV-curable resin, respectively. Through experiments and optical evaluations, it was verified that the newly proposed CR lens not only decreased the vertical light strength and glare effect from an LED light source but also improved the diffusion characteristics while maintaining the quality of the LED's light intensity.

A Case of Left Atrial Myxoma (좌심방 점액종 1례 보고)

  • 유수웅
    • Journal of Chest Surgery
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    • v.11 no.3
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    • pp.348-354
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    • 1978
  • Myxoma constitue about 50% of a II primary cardiac, tumor (incidence 0.03%) and occur in any of the cardiac chambers, but about 75% of themare found in the left atrium. As is well known, left atrial myxoma usually simulates mitral valvular disease, and it tends to bring about postural syncope and frequent embolic manifestaticns. The clinical manifestation of left atrial myxoma upon the circulation are obstructive effects, embolic effects and constitutional effects. Diagnosis is now most of all important since surgery can be dramatically curable, whereas untreated myxoma apparently invariably lead to deadful course. Preaprative diagncsis by echocardiogram is so simple and accurate for detection of myxoma that awareness of mitral valvular heart disease with rapid deterioration must be screened. We have diagnosed one case of the left atrial myxoma preopratively by phonocardiogram, echocardiogram and levophase pulmonary angiograJ;n and successfully treated by operation under extra corporeal circulation. A 38 years old housewife was admitted to the National Medical Center because of dyspnea, and paroxysmal cough on occasions for prior to hospitalization. Operation was carried out by median sternotomy and left atriotomy with mild hypothermia under E.C.C. The left atrial myxoma was extirpated including endocardial fragment and its weight was 23gm. The hospital course was not eventful and she can work nowadays without symptoms.

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