• 제목/요약/키워드: sample treatments

검색결과 491건 처리시간 0.031초

인쇄회로기판용 solder resist의 해상성과 밀착력 (Resolution and Adhesion Properties of Solder Resist for Printed Circuit Board)

  • 최성호;황성진;김형순
    • 한국재료학회지
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    • 제17권12호
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    • pp.676-681
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    • 2007
  • According to progress rapidly digitalization, networked and mobilization of electronics industry, there are demands for being smaller, thinner, more light, and more efficient complex functions of electronic devices which are wireless devices, semi-conductors, packages and mobile devices. Therefore, the solder resist on a printed circuit board have been required with the high resolution and the eco-friendly materials in the surface treatments such as high heating process and coating process with electrolysis. In this study, the photoinitiator initiator and monomers of the solder resist were prepared with their contents for reducing the occurrence of the under-cut. We investigated the sample surface by UV/VIS spectrometer, FT-IR, OM after HASL and ENIG process. From our results, it is possible to get a high adhesion of resist with optimal contents between the photoinitiator initiator and monomers after surface treatments.

HTV 실리콘 고무에서 열화인자에 따른 저분자량 성분과 표면 발수성의 변화 (Effects of Ageing Factors on Low Molecular Weight Silicone Fluids Content Fluids Content and Surface Hydrophobicity in HTV Silicone Rubber)

  • 허창수;연복희;조한구
    • 한국전기전자재료학회논문지
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    • 제12권1호
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    • pp.1-10
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    • 1999
  • In this paper, we have investigated the effects of the environmental factors on Low Molecular Weight (LMW) silicone fluid contents existing in high temperature vulcanized (HTV) silicone rubber sample, using dipping method and contact angle, current measurement. Artificial treatments such as immersion in water, elevated temperature, UV irradiation and dry band arcing under salt-fog condition are selected as the environmental factors. This results will be helpful to investigate the degradation with time and to expect a life time, because the LMW silicone content, which is important to recovery the hydrophobicity of silicone rubber surface, show different results by each environmental factors.

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처리 조건을 달리한 늙은호박 분말의 이화학적 특성 (Physicochemical Characteristics of Pumpkin(Cucurbita moschata Duch.) Powder with Different Treatment Conditions)

  • 신동선;유선미;박보람
    • 한국식품조리과학회지
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    • 제29권6호
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    • pp.691-697
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    • 2013
  • 본 연구에서는 저장성이 낮고 사용범위가 한정적인 늙은 호박을 이용하여 중간소재로 활용할 수 있도록 증숙, 냉동, 볶음 등의 처리 조건별로 호박분말을 제조하였으며, 제조된 호박분말의 일반성분, 수율 및 당도, 색도, DPPH 소거능, 환원당, 카로틴 등의 이화학적 특성을 조사하여 가공적성을 제시하고자 하였다. 호박 분말의 일반성분을 조사한 결과 수분이 13.61-16.05%, 조단백질이 9.40-9.53%, 조지방이 1.35-1.43%, 조회분이 0.26-0.50%, 수율은 5.01-5.65%로 나타났으며 당도는 $9.40-10.50^{\circ}Brix$로 나타났다. 색도를 측정한 결과 L값의 경우 대조군이 가장 높았고 a값은 증숙 처리군, b값은 볶음 처리군이 각각 높게 나타났다. DPPH radical 소거능에서 RC50값을 측정하였을 때 증숙 처리군에서 가장 높은 소거능을 나타내었다. 환원당 함량은 처리 조건에 따라 증숙(6.99 mg/g) > 대조구 (6.79 mg/g) > 볶음 (6.20 mg/g) > 냉동 (6.10 mg/g)으로 유의적인 차이를 보였으며 카로틴 함량은 대조구 (19.75 mg%) > 증숙 (17.91 mg%) > 냉동 (15.17 mg%) > 볶음 (14.04 mg%) 순서로 관찰되었다. 이상의 결과를 종합해 볼 때, 즉석용 호박분말을 제조하기 위해서는 증숙 처리군이 가장 좋을 것으로 보인다.

체감의이인탕(體減薏苡仁湯)이 비만유도 흰쥐의 체중, 지방조직, 혈액변화, leptin과 Uncoupled protein에 미치는 영향 (Effects of Chegameyiin-tang extract on the change of the weight, tissue in epididymal fat, blood, leptin and uncoupled protein in visceral fat of obesity rats induced by high fat diet)

  • 김길수;송재철
    • 한방비만학회지
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    • 제1권1호
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    • pp.85-100
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    • 2001
  • In Oriental medicine, there has been a theory that the deficiency of the Qi(氣) and the Phlegm(濕)-Damp(痰) bring Obesity. And so a clinically representative herb-medicine of the obesity treatments is Chegameyiin-tang . We observed the effects of Chegameyiin-tang on the fat tissues and what the function of Chegameyiin-tang is. These experimental studies were designed to investigate the effects of Chegameyiin-tang on the weight and lipid metabolism of obesity rats induced by high fat diet. And what is changed in the blood and how the leptin and uncoupled protein is affected. The measurement has been performed on (1) the weight of obese rats fed high fat diet, (2) the average size and number of epididymal fat cells, (3) the total cholesterol, triglyceride, glucose. and free fatty acids in the blood. and (4) the leptin and uncoupled protein in the blood are observed. The results are as follows; 1. In the sample group, the weight decrease occured significantly throughout the whole research period than that of control group. 2. In the sample group, epididymal fat weight showed significantly decrease in the 8th and 14th weeks than that of control group.3. In the sample group, epididymal fat cell size was decreased significantly in the 8th and 14th weeks than that of control group. 4. In the sample group, total cholesterol. triglyceride and glucose increased rather than control group in 8 weeks, those decreased significantly in 14 weeks. 5. In the sample group, free fatty acids and insulin increased rather than control group in 8 weeks. those showed some decrease in 14 weeks . 6. In the sample group, leptin decreased significantly than control group in 8, 14 weeks. Uncoupled protein showed some decrease in 8 weeks. that decreased significantly in 14 weeks.

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임상시험에서의 통계 활용 (Usage of Statistics in Clinical Trials)

  • 안홍엽
    • Journal of Hospice and Palliative Care
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    • 제13권1호
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    • pp.1-6
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    • 2010
  • 임상시험은 인간을 대상으로 약물 또는 치료법의 효과를 검증하는 것을 목적으로 하고 있다. 성공적인 임상시험을 위해서는 단순한 자료분석에만 통계의 이용을 제한하지 않고 다양한 영역으로 활용의 폭을 넓히는 것이 필요하다. 연구계획단계에서부터 구체적이고 체계적으로 통계의 활용을 고려하기 위해 효과에 대한 정의, 적정한 표본크기 산정, 통계분석 방법 등 전반적인 통계의 응용을 고찰한다.

Scanning Probe Microscopy를 이용한 고해 효과 연구 (Study of Refining Effects on Pulp Fibre by Scanning Probe Microscopy(SPM))

  • 김철환;;안경구
    • 펄프종이기술
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    • 제30권4호
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    • pp.49-58
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    • 1998
  • The SPM could image the most detailed microstructure of a sample in a wet and dry state by measuring the interaction between the atoms on the sample surface and the extremely sharp probe tip. The refined fibre exhibited large wrinkles formed by fibrillar bundles, the disintegrated fibres extensively showed “scale-like features”. By using the Non-Contact Atomic Force Microscopy (NC-AFM) and Contact Atomic Force Microscopy (C-AFM) including Phase Detection Microscopy (PDM) and Force Modulation Microscopy (FMM), it was possible to investigate surface topography, surface roughness and mechanical property (hardness or visco-elasticity) of fibre surface in detail. The PDM and FMM images showed that the disintegrated only fibre displayed uniform mechanical properties, whereas the refined one did not. The surface roughness of pulp fibres was higher in refined fibres than in disintegrated fibres due to the presence of external fibrils. These SPM images would be used to provide visual evidence of morphological change of a single fibre created during mechanical treatments such as refining, drying, calendering and so on.

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Nonparametric Tests for 2×2 Cross-Over Design

  • Gee, Kyuhoon;Kim, Dongjae
    • Communications for Statistical Applications and Methods
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    • 제19권6호
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    • pp.781-791
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    • 2012
  • A $2{\times}2$ Cross-over design is widely used in clinical trials for comparison studies of two kinds of drugs or medical treatments. This design has many statistical methods such as Hills-Armitage's (1979) method or Koch's (1972) method. In this paper, we propose a nonparametric test for $2{\times}2$ Cross-over design based on a two-sample test suggested by Baumgartner et al. (1998). In addition, a Monte Carlo simulation study is adapted to compare the power of the proposed methods with those of previous methods.

Optimization of Solid Phase Extraction Method for Quantitative Analysis of Perfluorooctanoic Acid in Serum using Liquid Chromatography-Tandem Mass Spectrometry

  • Lee, Hyun-Seok;Yim, Yong-Hyeon
    • Mass Spectrometry Letters
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    • 제5권1호
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    • pp.30-33
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    • 2014
  • A solid phase extraction (SPE) method was optimized for the quantitative analysis of perfluorooctanoic acid (PFOA) in serum using hydrophilic-lipophilic balance SPE and LC-MS/MS. Fetal bovine serums spiked with $^{13}C_8$-PFOA before or after SPE were used as test samples for evaluation of the SPE efficiency. Simultaneous evaluation of matrix effects and absolute SPE recovery for $^{13}C_8$-PFOA in serum using different sample pre-treatments and SPE conditions allowed optimization of SPE process efficiency with minimal matrix effect and decent SPE recovery. Introduction of protein precipitation as a sample pre-treatment procedure for serum samples before SPE generally decreased matrix effect in LC-MS/MS analysis and provided more stable recovery of PFOA.

Fast Screening of Harmful Disinfectants in Household Products via Low-Temperature Plasma Ionization-Mass Spectrometry

  • Lee, Hyoung Jun;Kweon, Gi Ryang;Yim, Yong-Hyeon
    • Mass Spectrometry Letters
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    • 제8권2호
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    • pp.44-47
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    • 2017
  • Isothiazolinone derivatives are widely used in consumer products as disinfectants or preservatives, but there are growing concerns about their impact on human health. Therefore, rapid screening of these biocides is very important for proper control and regulation of potentially hazardous substances. To this end, low-temperature plasma (LTP) ionization mass spectrometry (MS) was investigated to demonstrate its potential for direct and selective analysis of isothiazolinones from sprayed aerosol samples. Benzisothiazolinone (BIT) was clearly identified from a commercial fabric deodorant using LTP ionization MS and MS/MS. LTP allowed selective ionization of BIT directly from the simply sprayed aerosol sample and illustrated its potential for fast screening without sample pre-treatments. Selective nature of LTP ionization, on the other hands, implicates use of LTP ionization MS as a general screening method for specific groups of hazardous chemicals in commercial products.

Enhanced Cathodoluminescence of KOH-treated InGaN/GaN LEDs with Deep Nano-Hole Arrays

  • Doan, Manh-Ha;Lee, Jaejin
    • Journal of the Optical Society of Korea
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    • 제18권3호
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    • pp.283-287
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    • 2014
  • Square lattice nano-hole arrays with diameters and periodicities of 200 and 500 nm, respectively, are fabricated on InGaN/GaN blue light emitting diodes (LEDs) using electron-beam lithography and inductively coupled plasma reactive ion etching processes. Cathodoluminescence (CL) investigations show that light emission intensity from the LEDs with the nano-hole arrays is enhanced compared to that from the planar sample. The CL intensity enhancement factor decreases when the nano-holes penetrate into the multiple quantum wells (MQWs) due to the plasma-induced damage and the residues. Wet chemical treatment using KOH solution is found to be an effective method for light extraction from the nano-patterned LEDs, especially, when the nano-holes penetrate into the MQWs. About 4-fold CL intensity enhancement factor is achieved by the KOH treatments after the dry etching for the sample with a 250-nm deep nano-hole array.