냉각수 중에서 가스 흡수식 냉온수기 세관의 부식거동에 관한 연구

임우조(Uh-Joh Lim),정기철(Ki-Cheol Jeong),윤병두(Byoung-Du Yun) 대한기계학회 2002 대한기계학회 춘추학술대회 Vol.2002 No.10

This paper was studied on corrosion behavior of tube for gas absorption refrigerating and hot water systems in cooling water. In the tap water at 30 ℃, polarization test of Cu, 10 % cupronickel(90-10 Cu-Ni), 30 % cupronickel(70-30 Cu-Ni) and Al-brass tube was carried out. And polarization behavior, E-I(open circuit potential-corrosion current density), anodic polarization and cyclic polarization of heat exchanger tube for absorption refrigerating and hot water systems were considered. The main results are as following: 1) Open circuit potential of 10% and 30 % cupronickel becomes Jess noble than that of Cu, and noble than that of Al-brass 2) The corrosion current density of Al-brass is high than that of 10% cupronickel and Cu in low anodic potential region, but current density of Al-brass is controlled than 10% cupronickel and Cu over 350 mV/SCE 3) The controlled effect of pitting and crevice corrosion of Al-brass is excellent than cupronickel in tap water.

On the Reduction Potential of Cation-exchanged Heteropolyacids (HPAs)

Song, In Kyu,Kim, Han Soo,Chun, Myung-Suk 한국화학공학회 2003 Korean Journal of Chemical Engineering Vol.20 No.5

UV-Visible spectroscopy and scanning tunneling microscopy (STM) studies were performed to explore reduction potentials of cation-exchanged Keggin-type heteropolyacid (HPA) catalysts. Absorption band edge and negative differential resistance (NDR) peak voltage of cation-exchanged HPA samples determined by UV-Visible spectroscopy and STM, respectivley, were colsely related to their reduction potentials. It was observed that HPAs with higher reduction potentials showed absorption band edges at longer wave lengths and exhibited NDR peak voltages at less negative applied values. The reduction potentials of cation-exchanged HPA catalysts could also be correlated with the electronegativities of counter-cations. Substitution of more electronegative counter-cation increased reduction potentials of the HPAs. The NDR peak voltage and the absorption band edge of HPAs could be utilized as a correlating parameter for their reduction potentials.

Influences of Zeta Potential, Water Absorption and Surface Roughness of Porous Ceramics on Marine Bio-fouling

Sangwon Lee,Seunggu Kang 보안공학연구지원센터 2016 International Journal of Bio-Science and Bio-Techn Vol.8 No.2

The red tide organisms occurring at seashores in Korea damage the marine fish-raising industry every summer. Several methods to prevent the occurrence of red tide organisms, therefore, have been tried; one of them is to filter out red tide organisms using a membrane filled with porous ceramic bodies, allowing only fresh seawater to pass into a fish farm. When this method is used for long period of time, however, the problem of marine bio-fouling can develop on the surfaces of the porous ceramic body, deteriorating the filtering function of the porous bodies. In this paper, the influences of the zeta potential, water absorption and surface roughness of porous ceramics on marine bio-fouling have been inspected. In order to control the above three factors, three kinds of ceramic powders, alumina, titania and zirconia, were coated on the porous bodies. As a result, the water absorption and the surface roughness of the porous ceramics were found to be equally important factors in preventing bio-fouling, while the zeta potential of the specimens did not show a prominent effect. In detail, the water absorption of specimens was an effective factor in the early stages of bio-fouling for about one month; on the other hand, the surface roughness of the specimen was a main factor that could be used to control the amount of bio-fouling after one month. Among the three ceramic powders used as coatings, alumina, by imparting lower water absorption and higher surface roughness to the specimens, proved to be the optimum one to prevent marine bio-fouling.

Poly(laurylacrylate) 중합체의 오일흡수와 열역학적 해석

신영선,신연순,우제완,박상순,최중소 한국화학공학회 2002 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.40 No.1

단량체 laurylacrylate(LA), 가교성단량체 ethyleneglycoldimethacrylate(EGDMA) 및 개시제 benzoylperoxide(BPO) 등을 이용하여 현탁중합을 통해 poly(laurylacrylate)(PLA) 중합체를 합성하였다. 얻어진 PLA 중합체는 25-65℃의 온도범위에서 7종의 기름에 대하여 흡유능력을 측정하여 대부분 60분이내에 포화흡유능력을 보였으며, LA 99.867 wt%와 EGDMA 0.133wt%로 이루어졌을 때 가장 높은 흡유능력을 보였다. 또한 흡유능력은 온도증가에 따라 증가하였으며, 기름종류에도 더욱 의존하여 chloroform>toluene>o-xylene>THF>decane>octane>hexane순으로 감소하였다. 팽윤평형에 관한 열역학적 해석을 위하여 Wilson 모델을 도입하여 팽윤모델을 구성하였다. 팽윤모델은 혼합(Δμ_mix)과 탄성변형(Δμ_el)에 관한 두 종류의 화학포텐셜로 구성되었다. 추산된 팽윤모델의 상호작용에너지(λ_12-λ_11)는 온도증가에 따라 감소하였고, 열역학적으로 기름⑴과 중합체⑵ 성분간 Wilson parameter(A_12)는 증가하는 것으로 나타났다. The poly(laurylacrylate), PLA, polymers were prepared by an emulsion polymerization method. The laurylacrylate, LA, were used as the starting materials and ethyleneglycol dimethacrylate, EGDMA, as the crosslinker and benzoylperoxide as the initiator. The prepared PLA polymer was used to measure the oil-absorption capacity under various conditions and absorbed fastly each oil for seven types of oils within 60 min at temperature range 25℃ to 65℃. The maximum oil-absorption capacities increased with the increase of oil temperature and largely depended on the oil types. The decreasing order of oil-absorptio capacity with the increase of temperature was the order of chloroform>toluene>o-xylene>THF>decane>octane>hexane. We introduced Wilson model to construct the thermodynamic model on swelling equilibria. The model consists of two kinds of chemical potentials which they are mixing chemical potential(Δμ_mix) and elastic deformation chemical potential(Δμ_el). The λ_12-λ_11, which is the interaction energy between the molecules designated in the subscripts, decreased with the increase of oil-absorption temperature. It can be seen that the decrease of interaction energy brings about the increase of Wilson parameter(A_12) between oil⑴ and polymer⑵ component.

세라마이드 함유 에토좀의 물성과 피부흡수

현통일(Tong-Il Hyeon),윤경섭(Kyung-Sup Yoon) 한국응용과학기술학회 (구.한국유화학회) 2021 한국응용과학기술학회지 Vol.38 No.3

바이오틴을 피부에 전달하기 위해 고압균질기를 사용하여 바이오틴과 세라마이드를 모두 함유하는 에토좀에 대하여 연구하였다. 바이오틴이 주된 성분으로 사용되었으며, 세라마이드 NP는 인지질 이중층의 지지체로 활용되었다. 바이오틴은 수용성 내부에 포획되었고, 세라마이드 NP는 에토좀의 이중층에 흡착되었다. 세라마이드 NP를 함유한 에토좀의 물성을 살펴보면 소포체의 크기는 80∼130 nm, 다분산지수는 0.09∼0.16, 제타 전위는 -40∼-49 mV로 측정되었다. 세라마이드 NP가 없는 소포 체의 크기는 124.80±1.46 nm, 다분산지수와 제타전위는 각각 0.088±0.018과 -45.48±1.27 mV이었 다. 따라서 세라마이드 NP가 함유된 에토좀은 세라마이드 NP가 없는 에토좀에 비해 소포체의 물리적 특성이 개선됨을 알 수 있었다. 세라마이드 NP를 함유한 에토좀의 피부흡수율은 12시간 후 6.13∼ 14.98%이었으며, 반면에 세라마이드 NP가 없는 에토좀의 피부흡수율은 7.08%이었다. 결론적으로 세라 마이드 NP를 함유한 에토좀은 피부흡수 효율을 향상시킬뿐만 아니라 소포체의 안정성에도 긍정적인 영향을 미쳤다. In order to delivery biotin to skin, ethosomes containing both biotin and ceramide were researched by using high pressure homogenizer. Biotin was utilized as a drug and ceramide NP was utilized as a supporter of bilayer. The biotin was entrapped in aqueous core, while ceramide NP was packed in the bilayer of the ethosomes. Looking at the physical properties of vesicles containing ceramide NP, the sized was 80∼130 nm, the polydispersity index was 0.09∼ 0.16, and the zeta potential was -40∼-49 mV. In vesicles without ceramide NP, the size was 124.80±1.46 nm, and the zeta potential and polydispersity index were -45.48±1.27 mV and 0.088±0.018, respectively. Therefore, the ethosome with ceramide NP has improved physical properties of vesicles compared to the ethosome without ceramide NP. Skin absorption rates of ethosomes with ceramide NP were 6.13∼14.98%, while skin absorption rate of ethosome without ceramide NP was 7.08% at 12 h. In conclusion, ethosomes containing ceramide NP not only improved the skin absorption efficiency, but had also a positive effect on the stability of vesicles.

순천만 국가정원의 탄소 흡수 잠재량 평가 및 경제성 분석에 대한 연구

최종화 ( Jonghwa Choi ),김희준 ( Heejoon Kim ),정순철 ( Soonchul Jung ),장광민 ( Kwangmin Jang ) 한국전과정평가학회 2019 한국전과정평가학회지 Vol.20 No.1

우리나라는 국가 온실가스 감축목표를 달성하고자 저탄소 녹색성장 기본법 및 온실가스 배출권의 할당 및 거래에 관한 법률 등을 제정하고 배출권을 거래하는 제도를 도입함으로써 배출권거래제 상쇄제도를 운영하고 있다. 본 연구에서는 배출권거래제 상쇄 제도 중 식생복구 사업의 방법론을 적용하여 사업대상지의 잠재적 탄소 흡수량을 평가하고 외부사업의 추진에 따른 경제성을 분석 하였다. 연구결과 본 연구 대상의 연간 이산화탄소 흡수량은 1,179tCO₂-eq으로 평가되었다. 경제성 분석결과 갱신형으로 총 사업 기간을 60년으로 진행할 시 순이익은 21억원으로 경제성이 높은 것으로 나타났다. Korea has enacted laws and operated the emission trading system to effectively achieve the country’s greenhouse gas(GHG) reduction target by introducing a system for trading greenhouse gas emission rights. In this study, the potential carbon absorption is assessed by applying the methodology of the revegetation project in the business to the project site using the methodology of the emission trading system offset system, and then assessing the potential of the project site though economic analysis. The study found that the annual carbon dioxide absorption in this study was assessed at 1,179tCO₂-eq. Economic analysis shows that if the project is carried out to 60 years due to renewal, net profit is 2.1 billion won, which is more economical.

한국 내 해외자회사 시장지향성이 현지시장 지식획득 및 성과에 미치는 영향: 흡수능력의 역할을 중심으로

정갑연 한국기업경영학회 2013 기업경영연구 Vol.20 No.6

In response to an increased need of balancing pressures for global integration and local responsiveness, foreign subsidiaries are demanded to play a prominent role in creating and transferring knowledge, valuable for the multinational corporation (MNC). In this context, a key managerial problem pertains to identifying the relationship between local market knowledge acquisition of foreign subsidairy and performance. If companies want to acquire local market knowledge, they should precede market orientation. Especially, foreign subsidiary that takes charge of business activities in unfamiliar environment has to obtain various factors to acquire local market knowledge. Prior to this, it’s most important that companies construct organizational culture which leads them to fully understand the desire of local customers and the strategy for the local market. This study is to examine that the market orientation of foreign subsidiary influences on the local market knowledge acquisition and performance of foreign subsidiary through variables of the potential absorptive capacity of foreign subsidiary, the local relational embeddedness, and the learning experience of foreign subsidiary. Also this study identify the moderating effect of realized absorptive capacity between the local market knowledge acquisition and performance of foreign subsidiary. For a more realistic approach the data was collected from foreign subsidiaries in South Korea. 253 samples were used for this analysis with AMOS (7.0 version) and SPSS (15.0 version). Collected samples were tested by factor analysis and Cronbach’s Alpha coefficients and were found to be satisfactory in terms of validity and reliability. Furthermore, fitness of the measurement model was tested by using confirmatory factor analysis and fitness of the model for hypothesis testing was adequate on various goodness of fit indices. There are following empirical results. First, the market orientation of foreign subsidiary has a significant effect on the potential absorptive capacity of foreign subsidiary, the local relational embeddedness, and the learning experience of foreign subsidiary. Second, the local relational embeddedness, and the learning experience of foreign subsidiary have an effect on the potential absorptive capacity of foreign subsidiary, Third, the potential absorptive capacity of foreign subsidiary only play a significant role on the local market knowledge acquisition. Finally, the realized absorptive capacity play a significant role in moderating between the local market knowledge acquisition and performance of foreign subsidiary. Even though this study tried hard to provide meaningful results and implications, there still are some limitations. First, since we had selected foreign subsidiaries as subjects of the analysis, we only chose the ones that run their business only in Korea. Thus, it may not be appropriate to argue that the result of this study can be applied to other countries, because of different cultures and systems. Second, this study put restraints on the subjects of the analysis by selecting only foreign subsidiaries of MNCs currently operating production and sales in Korea. Accordingly, it is hard to say that the result of this study can be adapted to other subsidiaries which were established under different purposes such research and development or resource development. Finally, since we only got the response from one personnel per each corporation, the result of the analysis can be biased by subjectivity of the respondent. In other words, the problem of common method bias can occur. To settle those problems, further studies could use the second source added to questionnaire to minimize such problem, for example, getting a multiple response from one subsidiary, or using more objective measurements such as an introduction rate of technology acquired in local market in measuring the level of local market knowledge acquisition. 최근 다국적기업의 경쟁우위 창출에 있어 해외자회사의 역할이 중요시 되면서 상대적으로 부족했던 해외자회사의 현지시장에서의 지식획득에 관한 논의가 점차적으로 주목을 받고 있다. 따라서 본 연구는 해외자회사의 시장지향성, 현지시장 지식획득, 그리고 자회사 성과와의 관계를 규명하고자 하였다. 즉, 해외자회사가 시장지향성 조직문화를 통해 구축할 수 있는 현지시장 지식획득의 영향요인으로 해외자회사 잠재적 흡수능력, 현지국 관계적 체화성, 그리고 해외자회사의 학습경험을 고려하였다. 또한 이렇게 획득된 현지 시장지식이 자회사의 성과에 영향을 미치는데 있어 자회사의 실현적 흡수능력의 조절효과를 살펴보고자 하였다. 이를 위해 한국에 진출한 253개의 다국적기업 해외자회사를 대상으로 조사를 하였으며, AMOS(7.0 version)과 SPSS(15.0 version)을 사용하여 수집된 자료를 분석하였다. 그 결과 해외자회사의 시장지향성은 자회사의 잠재적 흡수능력, 현지국 관계적 체화성, 그리고 자회사 학습경험 모두에 유의한 영향을 미쳤고, 현지국 관계적 체화성, 자회사 학습경험은 자회사의 잠재적 흡수능력에 긍정적인 영향을 미치는 것으로 확인되었다. 반면 앞선 세 요인들과 현지시장 지식획득 간의 관계에 있어서는 해외자회사의 잠재적 흡수능력만이 긍정적인 영향을 미침을 확인하였다. 또한 해외자회사 현지시장 지식획득은 자회사 성과에 긍정적인 영향을 미쳤으며, 이들의 관계에 있어 자회사의 실현적 흡수능력이 조절효과가 있음을 확인하였다.

산림분야 외부감축사업에 따른 흡수 잠재량 평가에 대한 연구

최종화 ( Jonghwa Choi ),주선호 ( Sunho Joo ),정순철 ( Soonchul Jung ),장광민 ( Kwangmin Jang ) 한국전과정평가학회 2019 한국전과정평가학회지 Vol.20 No.1

By introducing a system to trade greenhouse gas(GHG) emission rights, the government has enacted laws to effectively achieve the country's GHG reduction targets and has been operating a carbon offset system for emissions trading. The ministry of forest operates carbon offset schemes to improve the carbon uptake of forests. In this study, we evaluate the potential of carbon stocks by analyzing the potential carbon uptake by using the methodology in forest carbon offsets system.

중국진출 다국적기업의 기술이전 역량과 제품개발 성과의 관계에서 시장 요인의 조절효과

정재휘,조연성 한국전문경영인학회 2014 專門經營人硏究 Vol.17 No.2

This study looked at the path of the technology transfer and the product development between the headquarters and the subsidiary of MNEs in China market. The capabilities related to the technology transfer were divided by a disseminative capability and a absorptive capability. Technology transfer and product development were major factors in performance. As a external environmental factors, there were the market potential and the degree of the intellectual property right protection and the moderating effect hypothesis were proposed using these factors. Seven hypotheses including moderating effects were analyzed using a structural equation model to the 93 manufacturing MNEs. The results of the analysis, the both of the disseminative capability of headquarters and the absorption capabilities of subsidiary had a positive effect on the technology transfer. Technology transfer and also had a positive impact on product development performance. The moderating effect showed when MNEs think the degree of the intellectual property protection is not enough in China, the moderating effect between it and the disseminative capability has a negative impact on technology transfer. The market potential did not show the moderating effect. Based on above discussions, this study looked at the implications and discuss limitations and future research directions.

침치료 원리를 이용한 안면 통증 치료기 개발

이용흠,박창규,Lee Yong-Heum,Bak Chang-Gye 한국정보통신학회 2005 한국정보통신학회논문지 Vol.9 No.5

We developed an orofacial pains diagnosis/therapy system which can enlarge a therapy effect through a new stimulation. Contrary to its established method, this therapy system(DDTS-1) is a treating method which absorbs a surplus ion charge- the cause of an outbreak of a pain-of the human body using a capacitor. Absorbing a surplus ion charge of the human body with effect, it obtained optimal parameters which is control signal to control charging/discharging a capacitor to be 6Hz, and capacitance to be $0.1\~0.33{\mu}F.$ Through clinical demonstration, experimented on among patients-namely dental pain patients, joint disorders patients, and trigeminal neuralgia patients to verification of system. In result, an EAST stimulater had a very low change of abnormal potential against normal potential before/after being placed under medical care. DDTS-1 showed obvious differences that two potentials are one and the same potential or one potential is similar to the other one. DDTS-1 comparing with EAST showed the remedial value of the comparative advantage in all the medical treatment of pains. Therefore, stimulation of DDTS-1 is more effective than the existing electric stimulation. We verified its validity of ion charge absorption in the human body using capacitor which presented the present thesis. That is, we verified theoretical adequacy of control action in a pain, and its efficiency as well as confidence. 한의학적 침구치료원리에 근거한 새로운 자극방식을 통해 치료효과를 증대시킬 수 있는 구강안면 동통 진단/치료기를 개발하였다. 이 새로운 DDTS-1 치료기는 기존방식과는 달리 캐패시터를 이용하여 동통발생 원인인 인체의 과잉 이온전하를 흡수하여 치료하는 방식이다. 과도한 이온전하를 흡수하여 치료하기 위한 최적 파라미터 추출은 실험을 통해, 캐패시터의 충방전을 제어하기 위한 제어신호의 최적의 주파수는 6hz, 캐패시턴스는 $0.1\~0.33{\mu}F$으로 결정하였다. 임상실험을 통해 시스템의 검증을 위해 치성동통환자, 3차 신경통환자 등을 대상으로 정상부위와 이상부위의 전위를 측정하였다. 그 결과, 기존 자극기는 치료전과 후의 전위차가 매우 작았으며 DDTS-1은 생체전위차가 동일하거나 비슷해지는 뚜렷한 차이를 보였다. 따라서, DDTS-1의 자극방식이 기존의 전기적 자극방식보다 치료효과 측면에서 더 효과적이며 이는 캐패시터를 이용한 인체 이온전하 흡수방식의 타당성을 검증하였다. 즉, DDTS-1 치료기의 자극방식에 따른 동통조절기전의 이론적 타당성을 검증하고 성능 및 신뢰성을 검증하였다.