• Proceedings of the Materials Research Society of Korea Conference
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• 2011.05a
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• pp.33.1-33.1
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• 2011

최근 산업에서는 산업의 고도화로 인한 환경오염이 큰 문제로 대두되고 있다. 이러한 문제점을 해결하기 위한 방안 중, 친환경소재에 대해 연구가 활발히 진행하고 있다. 연잎의 자기세정효과(self-cleaning effect)에 관한 연구는 이러한 친환경소재에 대한 연구 중 하나이다. 연잎의 표면은 마이크로 크기의 돌기와 나노 크기의 왁스의 dual-scale의 구조로 이루어져 있으며, 왁스의 경우 소수성을 가진다. 이러한 dual-scale 구조와 소수성의 왁스에 의해 초소수성이 발현되고, 결과적으로 연잎의 자기세정효과가 발현된다. 본 연구에서는 나노임프린트 리소그래피와 수열합성법을 이용한 나노로드 성장을 이용하여, 연잎의 dual-scale의 표면구조를 형성하는 실험을 진행하였다. 나노임프린트 리소그래피와 수열합성법은 다른 공정에 비하여 상대적으로 적은 비용을 필요로 하고, 대면적에 적용이 가능한 기술이다. 실험 진행은 먼저 silicon 마스터 스탬프를 역상으로 복제한 PDMS (Polydimethylsiloxane) 스탬프와 $TiO_2$ sol을 이용하여 기판 위에 $TiO_2$ gel 패턴을 형성한 후, 열처리 과정을 통해 $TiO_2$ gel 패턴을 결정화한다. 다음으로 결정화된 $TiO_2$ 패턴 기판을 수열합성 방법을 이용하여 $TiO_2$ 나노로드를 무작위적으로 형성하였다. 마지막으로 소수성을 갖는 자기 조립 단분자막 용액을 이용하여 소수성 표면처리를 한 후 접촉각을 측정하였다. 본 연구에서 개발한 기술을 이용하여 다양한 형태의 기판에 초소수성 표면을 형성할 수 있고, 자기세정효과를 갖는 표면을 구현할 수 있다.

• The Safety technology
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• no.189
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• pp.22-23
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• 2013

종합부품기업 아이원스(주)는 1993년 3월 자동차 미디어 관련 부품제작 업체인 동아엔지니어링으로 출발했다. 1994년에는 반도체 LCD부분 그리고 2003년에는 삼성전기(주)광디바이스 사업으로 진출했으며, ISO9001 ISO14001 인증을 획득한 후 2005년 벤처기업으로 등록하면서 전도유망한 기업으로 성장해왔다. 이후 2005년 아이원스 주식회사로 법인전환을 하면서 2006년 기흥 세정공장 준공, 2007년 삼성전자 메모리 사업부 세정 협력업체 등록, 병역 특례업체 선정, 2011년 삼성전자 생산기술연구원 업체 등록, 2013년 2월 코스닥 상장 등으로 지속적인 발전을 이어오게 된다. 이곳의 이러한 성장에는 이문기 대표이사의 안전에 대한 각별한 신념이 밑거름이 됐다. 직원들의 안전을 회사의 가장 큰 가치로, 그리고 직원들을 회사의 가장 큰 자산으로 여기고 안전에 집중 투자하면서 무재해를 이어온 것이 기업 성장의 원동력이 된 것이다. 안전경영의 좋은 본보기가 되고 있는 이문기 대표이사를 찾아가 그만의 안전철학을 들어봤다.

• Korean Journal of Materials Research
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• v.11 no.5
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• pp.361-366
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• 2001

It is difficult to obtain high Cu nucleation density and continuous Cu films in Cu-MOCVD without cleaning the TiN substrate prior to Cu deposition. In this study effects of plasma precleaning on the Cu nucleation density were investigated using SEM, XPS, AES, AFM analyses. Direct plasma pretreatment is much more effective than remote plasma pretreatment in enhancing Cu nucleation. Cleaning effects are enhanced with increasing the rf-power and the plasma exposure time in hydrogen plasma pretreatment. The mechanism through which Cu nucleation is enhanced by plasma pretreatment is as follows: Hydrogen ion\ulcorner in the hydrogen plasma react with TiN to form Ti and $NH_3$ Cu nucleation is easier on the Ti substrate than TiN substrate.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.11 no.5
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• pp.23-29
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• 2002

The soldering is widely used installing the electronic element on circuit board in the common electronic device. Since the flux which improves the liquidity of solder make the electronic and chemical performance worse, the circuit board need to wash clearly. At present however no-washing is required for the cost reduction, the chemical stability, and the protection of environment. In this research, the solder liquidity depending on the power density and the pulse width is comparatively analyzed by the diffusion area method for achieving the no-flux soldering.

• Clean Technology
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• v.6 no.1
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• pp.51-60
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• 2000

The soil remediation by non-ionic surfactant solutions ($C_{12}H_{25}O(CH_2CH_2O)_5H$ and Triton X-100) was studied. Depending on the amounts and use of co-surfactants, MPT(phase inversion temperature), dynamic interfacial tension, and the detergency efficiency of the surfactant solutions in soil were investigated. The oils used were kerosene, n-hexadecane, and paraffin oil. With respect to a higher detergency efficiency, a lower interfacial tension and the MPT was very important. The $C_{12}H_{25}O(CH_2CH_2O)_5H$ was better than Triton X-100 on the oil removal from the soil and the effect of oil kinds was kerosene>paraffin $oil{\geq}n-hexadecane$. The co-surfactant, n-dodecanol, reduced the MPT compared to no addition of this, whereas it did not enhance the detergent efficiency.

• Journal of Naturopathy
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• v.11 no.1
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• pp.31-38
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• 2022

Background: New beauty soaps are always subject to evaluation. Purposes: This study performed a human application test and safety evaluation on the cleaning effect of the fine dust mimic of the test product, Daziwar soap bar, on 52 women. Methods: The quantitative change measured the cleaning effect of fine dust before and after washing immediately after spraying the fine mimetic dust on the forearm of 22 women. In addition, the safety was evaluated at 30 minutes, 24 hours, and 48 hours after 24 hours after applying the patch to the woman's back. Results: After one time washing with the soap immediately after spraying dust on the inside of the arm, the amount of the remaining mimetic was statistically significantly decreased in both the test group and the control group (p < .001). However, the washing rate was 99.96% in the experimental group and 75.58% in the control group. The questionnaire was evaluated as 'Good' or higher in terms of efficacy. In the evaluating of adverse reactions after washing fine dust by a dermatologist, there were no reports or observations of specific skin adverse reactions or abnormal findings in the subjects. The safety evaluation was judged as non-irritating in the skin reaction evaluation at 30 minutes, 24 hours, and 48 hours after instillation on the back for 24 hours. Conclusions: The test product, Daziwar soap, was found to be very helpful in cleaning fine dust on the human body and was found to be safe for the human body.

• Journal of the Korean Vacuum Society
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• v.10 no.2
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• pp.267-274
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• 2001

Removal of Cr, Ni and Cu impurities on Si surfaces using remote plasma-excited hydrogen was investigated. Si surfaces were contaminated intentionally by acetone with low purity. To determine the optimum process condition, remote plasma-excited hydrogen cleaning was conducted for various rf-powers and plasma exposure times. After remote plasma-excited hydrogen cleaning, Si surfaces were analyzed by Total X-ray Reflection Fluorescence(TXRF), Surface Photovoltage(SPV) and Atomic Forece Microscope(AFM). The concentrations of Cr, Ni and Cu impurities were reduced and the minority carrier lifetime increased after remote plasma-excited hydrogen. Also RMS roughness decreased by more than 30% after remote plasma-excited hydrogen cleaning. AFM analysis results also show that remote plasma-excited hydrogen cleaning causes no damage to the Si surface. TXRF analysis results show that remote plasma-excited hydrogen cleaning is effective in eliminating metallic impurities from Si surface only if it is performed under an optimum process conditions. The removal mechanism of the Cr, Ni and Cu impurities using remote plasma-excited hydrogen treatments is proposed to be the lift-off during removal of underlying chemical oxides.

• Korean Journal of Poultry Science
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• v.16 no.2
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• pp.91-100
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• 1989

This study was conducted to observe 1) the changes of cellular association in seminiferous tubles from 2 to 8 weeks of age, and 2) the cycle phenomena of seminiferous epithelia at 14 weeks of age in Japanese quail. Total 80 birds were examined at a week interval from 2 to 8 weeks, and 14 weeks of age. The results were summarized as follows： 1) The body and testis weights showed most prominent increase during 4 to 5 weeks and 6 to 8 weeks of age respectively. And also the diameters of seminiferous tubles were abruptly enlaged during 6 to 8 weeks of age. 2) Genocytes in the seminiferous tubles were still in existence at 3 weeks of age, however they did not come out after 4 weeks of age. Spermatogonia, primary spermatocytes and spermatids made their first arpearances in the seminiferous from 3, 4 and 6 weeks of age, respectively. Spermatozoa were observed for the first time at 7 weeks of age, but full spermatogenic activity was completed from 8 weeks of age. 3) At 14 weeks of age, the average weight at testis was 3.7g and its ratio to the body weight was approximately 3.0 percent. And at this age, average diameter of seminiferous tubules was 192.08 $\mu\textrm{m}$, and average numbers of spermatogonia, spermatocytes, spermatids and spermatozoa within the cross section of seminiferous tubules were 7.74, 40.81, 28.42, 104.55 and 105.98, respectively. Spermatogonia and spermatid were classfied into 2 and 3 types, respectively. 4) At 14 weeks of age, the cycle of seminiferous epithelium could be divided into S stages with following characteristics. (1) Stage I： Seminiferous tubules showing type I and II spermatids. (2) Stage II： Seminiferous tubules showing type III spermatids only. (3) Stage III： Immature spermatozoa gathered near the sertoli cytoplasm. (4) Stage IV： Forming a bundle of 15-20 spematozoa. (5) Stage V： Spermatozoa bundle leaving the sertoli cytoplasm into lumen of the seminferous tubule. 5) Usually 2-3 stages of the seminiferous epithelium cycle were concurrently appeared within a tubular cross section, and frequency of each stage from I to V within cross section of seminiferous tubules were 11.91%, 27.03%, 27.96%, 19.04% and 17.98%, respectively.

• Korean Journal of Materials Research
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• v.6 no.8
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• pp.817-824
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• 1996

Removal of Cu impurities on Si substrates using remote H-plasma was investigated. Si substrates were intentionally contaminated by 1ppm ${CuCI}_{2}$, standard chemical solution. To determine the optimal process condition, remote H-plasma cleaning was conducted varying the parameters of rf power, cleaning time and remoteness(the distance between the center of plasma and the surface of Si substrate). After remote H-plasma cleaning was conducted, Si surfaces were analysed by TXRF(total x-ray reflection fluorescence) and AFM(atomic force microscope). The concentration of Cu impurity was reduced by more than a factor of 10 and its RMS roughness was improved by more than 30% after remote H-plasma cleaning. TXRF analysis results show that remote H-plasma cleaning is effective in eliminating Cu impurity on Si surface when it is performed under the optimal process condition. AFM analysis results also verifies that remote H-plasma cleaning makes no damage to the Si surface. The deposition mechanism of Cu impurity may be explained by the redox potential(oxidation-reduction reaction potential) theory. Based on the XPS analysis results we could draw a conclusion that Cu impurities on the Si substrate are removed together with the oxide by a "lift-off" mechanism when the chemical oxide( which forms when Cu ions are adsorbed on the Si surface) is etched off by reactive hydrogen atoms.gen atoms.

• Food Science and Preservation
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• v.11 no.2
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• pp.160-169
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• 2004

This study was carried out to investigate the efficacy of electrolyzed water manufactured with or without diaphragm on sterilization and preservation of cut-celery and shelled raw oyster. In cut-celery, total viable cell count and coliform group in the treatment of electrolyzed water were decreased to about 1/200∼1/1,000 level and about 1/100 level comparing non-treated ones. But moisture content, pH, hardness, vitamin C and residual chlorine content were showed a little difference among treatments up to 10 days at 10$^{\circ}C$. L and a color values were gradually increased in all treatments, and color differences($\Delta$E) were remarkable between treatment and untreatment sample. In overall acceptability, cut-celery treated with electrolyzed water showed somewhat higher score than that of other ones treated with tap water and 100 ppm NaClO solution until 5 days of storage. After 48 hours of storage, it was showed that VBN, total viable cell count and coliform count of shelled raw oyster treated with electrolyzed alkali water produced by non-diaphragm system are lower by about 3 mg%, 1∼2 log cycle and 2 log cycle respectively than that of ones treated with sea water. Total viable cell count of shelled raw oyster just after treatment was lower by about 1 log cycle than that of ones treated with sea water, and any significant increment was not found after 24∼48 hours of storage.