• Journal of the Korean Wood Science and Technology
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• 제48권2호
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• pp.231-244
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• 2020

As a way of finding value-added materials from waste medium density fiberboard (MDF), this study characterized cellulose nanocrystals (CNCs) isolated by ammonium persulfate (APS) oxidation using recycled MDF fibers. Chemical composition of the recycled MDF fibers was done to quantify α-cellulose, hemicellulose, lignin, nitrogen, ash and extractives. The APS oxidation was performed at 60 ℃ for 16 h, followed by ultrasonication, which resulted in a CNC yield of 11%. Transmission electron microscope images showed that rod-like CNCs had an average length and diameter of 167±47 nm and 8.24±2.28 nm, respectively, which gave an aspect ratio of about 20. The conductometric titration of aqueous CNCs suspension resulted in a carboxyl content of 0.24 mmol/g and the degree of oxidation was 0.04. Attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy clearly showed the presence of carboxyl group on the CNCs prepared by the APS oxidation. The change of pH of the aqueous CNC suspension from 4 to 7 converted the carboxyl group to sodium carboxylate group. These results showed that the APS oxidation was facile and CNCs had a one-step preparation method, and thus suggested an optimization of the oxidation condition in future.

• 조명전기설비학회논문지
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• 제25권12호
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• pp.11-20
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• 2011

PSALI is referred to the supplementary lighting for the interior lighting under the daily lighting situation, and pursuant to the pertinent regulations in energy savings design standard and others in recent architecture works, the importance thereof has been increasing gradually coupled with the energy performance index (EPI), energy savings plan and the like as well as expansion of submittal and implementation policies. However, this type of PSALI studies indeed have a number of limitations since it has surrounding environmental conditions in direction, season, region, climate, time, opening rate, window area ratio, actual index, reflection rate of finishing materials and others in the architecture work as well as frequent changes in interior lighting environment for variables in daily light volume flowing into the interior, and others. Therefore, this study has analyzed existing advance research cases to produce the actual-sized model and scaled-down model, and installed the artificial lighting of LED light source possible to reproduce with same capability on both models. As a result of comparison and analysis of the artificial lighting with the key light, it has certain level of error rate from the scaled down lighting device in certain rate and actual model butit was noticeably significant within specific scope.

• 한국전기전자재료학회논문지
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• 제18권10호
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• pp.936-940
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• 2005

IMML(Inorganic metal multi-layer) was used as cathode in the OLED devices to reduce the reflectance or ITO and increase the contrast ratio. Device structure was $ITO/{\alpha}-NPD/Alq_3:DCJTB/Alq_3/IMML/Al$. $Alq_3$ and DCJTB (4 - (dicyanomethylene) - 2 - ( 1 - propyls) 6 - methy 4H - pyrans) as host material lot red emission and red emitting guest material. IMML made three different layer: thin aluminum layer, aluminum layer doped with silicon monoxide, thick aluminum layer. The red OLED device with IMML showed the average reflectance of $4.97\%$, and then normal OLED with or without polarizer showed the average reflectance of $4.55\%$, $46\%$ at visible range from 380 nm to 780 nm. The brightness of OLED with IMML at 13 V was 5557 $cd/m^2$, and that of normal OLED with polarizer was 4872 $cd/m^2$. IMML could be the substitution for polarizer with same reflection, low cost, easy process in flat panel display market.

• International Journal of Industrial Entomology and Biomaterials
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• 제26권1호
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• pp.54-60
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• 2013

The partial degumming of silk has recently attracted researchers' attention because of its ability to produce silk textiles with new tactile properties, intermediate between the softness of fully degummed silk and the hardness of raw silk. However, it is difficult to obtain partially degummed silk in a homogenously degummed state due to the heterogeneous character of sericin removal. It is also difficult to examine the homogeneity of degumming. In the present study, Fourier transform infrared (FTIR) spectroscopy with attenuated total reflection (ATR) geometry was used to evaluate the effect of processing conditions on the degumming of silk yarns. The crystallinity index, calculated from FTIR spectra, showed an increase with the degumming ratio. Therefore, the homogeneity of degumming could be evaluated by the variation of crystallinity index for 30 different spots in silk yarns. The homogeneity of degumming was influenced by the total degumming time, the content of surfactant, and the liquor rate. No effect was observed upon changing the number of degumming cycles at the same total degumming time.

• 멤브레인
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• 제4권3호
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• pp.142-151
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• 1994

역삼투 공정을 농축공정에 이용하기 위해 향류식 역삼투 나권형 모듈을 고안, 제작하여 염수의 농축실험을 수행하였다. 역삼투 분리의 배제도와 농축도의 관계를 고찰한 결과, 배제유량에 대한 투과유량의 비가 양쪽 관계의 중요한 매개 변수이며, 반사계수 값에 따라, 역삼투막의 배제도와 농축도가 Spiegler-Kedem 식의 경향을 따른다. 향류식 역삼투 공정은 일반 역삼투 농축 공정에 비해 농축의 장애 요소인 삼투압차를 효과적으로 저하시키는 효과가 있으며 농축도가 상대적으로 우수하였다. 향류식 나권형 모듈의 수치모사 결과 농축공정의 농축도 증가를 위해서는 모듈의 지름보다 모듈의 길이를 늘리는 것이 유리함을 알 수 있었다.

• 한국지반환경공학회 논문집
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• 제9권1호
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• pp.27-31
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• 2008

본 연구는 직경 225mm의 KICT 대구경 샘플러와 NX size 피스톤 샘플러를 사용하여 채취한 점토시료의 강도정수를 비교하여 대구경 샘플러가 NX size 피스톤 샘플러에 비해 원지반 상태를 얼마나 잘 반영하는가를 평가하는데 그 목적이 있다. 이 연구를 위하여 두 가지 샘플러로 채취한 점토 시료를 동일 조건에서 표준압밀시험, 일축압축시험, 삼축압축시험을 수행하여 채취 시료의 교란도 분석을 하였다. 분석결과 초기간극비와 선행압밀응력 뿐만 아니라 시료의 일축 및 삼축압축 시험에 의한 강도정수도 KICT 대구경 샘플러에 의한 시료가 약 10% 이상 높게 나타났다.

• 문화기술의 융합
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• 제2권4호
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• pp.61-64
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• 2016

스마트폰 보급이 증가함에 따라 기존의 쇼핑몰 역시 모바일 시장에 적극적으로 가세하며 모바일 쇼핑 시장의 경쟁을 더욱 더 가속하고 있다. 이는 모바일 쇼핑시장이 더 이상 무시할 수 없는 거대한 시장으로 성장 중이라는 것의 반증이라고도 볼 수 있다. 본 논문에서는 모바일 시장의 증가와 모바일 시장에서 가장 높은 비율을 차지하는 의류에 관한 모바일 쇼핑몰 어플리케이션이다. 본 연구는 좀 더 세세한 고객 정보를 토대로 고객만족도를 높이며, 부차적으로는 반품률을 낮춰 기업과 고객 모두의 만족도를 높이는 것을 목표로 한다.

• ETRI Journal
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• 제39권3호
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• pp.390-397
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• 2017

In this paper, we propose a scheme for designing a tunable pixel layer based on a $Ge_2Sb_2Te_5$ (GST) alloy thin film. We show that the phase change of GST can significantly affect the reflection characteristic when the GST film is embedded into a dielectric encapsulation layer. We investigate the appropriate positions of the GST film within the dielectric layer for high diffraction efficiency, and we prove that they are antinodes of Fabry-Perot resonance inside the dielectric layer. Using the proposed scheme, we can increase the diffraction efficiency by about ten times compared to a bare GST film pixel, and 80 times for the first-to-zeroth-order diffraction power ratio. We show that the proposed scheme can be designed alternatively for a broadband or wavelength-selective type by tuning the dielectric thickness, and we discuss a multi-phase example with a double-stack structure.

• 대한한방소아과학회지
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• 제19권1호
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• pp.131-141
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• 2005

Objective : The objective of this study is to assess the clinical effect of Naesowhajungtang Gamibang on atopic dermatitis. Method : A total of 30 patients with atopic dermatitis were evaluated for the symptoms and signs according to SCORAD index and measured for peripheral eosinophil counts and serum total IgE before and after treatment. Results : 1. Among 30 patients diagnosed as Atopic Dermatitis, 11, were male(37%) and 19 were female(63%). the ratio of male and female patients were 1:1.7. 2. Among 30 patients diagnosed as Atopic Dermatitis, 25 Have family history of allergic disease(83%) and 20 have past history of allergic discase. 3. There was statistically significant relationship between serum total IgE and SCORAD score(p=0.019). 4. There was statistically significant relationship between peripheral eosinophil count and SCORAD score(p=0.001). 5. We could find no statistically significant change of serum total IgE and peripheral eosinphil count before and after treatment. 6. There was statistically significant change of SCORAD score and subjective symptom before and after treatment.(p<0.05). Conclusion : Naesowhajungtanggamibang is effective in the treatment of atopic dermatitis. And peripheral eosinophil counts and serum total IgE were good serum maker reflection the severity of atopic dermatitis.

• 전자공학회논문지A
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• 제31A권9호
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• pp.96-103
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• 1994

The GaAs epilayer was grown at low temperature (LT. 250.deg. C) by molecular beam epitaxy. The properties of the LTT GaAs, before and after Rapid Thermal Annealing(RTA), were analyzed by Reflection of High Energy Electron Diffraction (RHEED), Double Crystal X-ray(DCX), Raman spectroscopy, PL and Photo-Induced Current Transient Spectroscopy (PICTS). The LT GaAs before RTA, was analyzed by RHEED and DCX, with a result of an improved surface morphology under a relatively As-rich(As/Ga ratio :28) condition, and of an increased lattics parameter of 1.1 1.7% in comparison with a GaAs substrate. However DCX and Raman spectroscopy revealed that the expanded lattics parameter and the crystallinity of LT GaAs could be recovered after RTA. On the other hand, PL spectra indicated that LT GaAs after RTA showed low optical sensitivity unlike High Temperature(HT) GaAs, and that its surface morphology and crystallinity were corresponded with those of HT GaAs. Finally PICTS spectra proved the fact that low sensitivity of LT GaAs was due to the deep level defects (Ec-0.85eV) which were strogly formed by raising RTA temperature to 750.deg. C.