• 한국산학기술학회논문지
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• 제21권10호
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• pp.574-580
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• 2020

무기바인더는 저온에서 경화가 가능하며, 유해가스를 배출하지 않는 친환경성과 중자 조형 시 성형된 제품의 결함이 작다는 장점으로 인해 주조 산업에 적용하고자 관련 연구가 급속도로 진행되고 있다. 그러나 실리케이트(SiO₂-Na₂O)를 주성분으로 하는 무기바인더는 실리케이트 특유의 흡습성으로 인해 공기 중 수분을 흡습하여 결합력이 약해져 주형의 강도가 급격히 감소하는 문제가 있다. 특히 주강 주조에 사용되는 사형 주형의 경우 알루미늄 주조보다 높은 주입 온도로 인해 고강도의 주물 특성을 요구한다. 이에 본 연구에서는 무기바인더의 강도와 흡습성을 개선하기 위해 에스테르기를 함유하는 왁스를 이용하여 이를 효율적으로 합성하는 방법을 연구하였다. 또한 합성된 무기바인더의 특성을 XRF와 TGA를 통해 확인하고, 일반강도와 내수강도 평가를 진행하여 주형의 강도 개선 여부를 확인하였다. 그 결과 에스테르기를 함유하는 왁스를 포함한 무기바인더의 경우 일반 강도가 증가하였으며, 특히 내수강도가 118 N/㎠에서 216 N/㎠까지 증가하여 약 55 %의 내수강도 개선 효과를 확인하였다. 또한 실제 주강 제품을 제작한 뒤 주조를 통해 우수한 주조 특성을 확인하였다.

• Asian-Australasian Journal of Animal Sciences
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• 제30권11호
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• pp.1605-1611
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• 2017

Objective: Following a previous report, an experiment was conducted to determine the effect of increasing level of dried stoned olives pomaces (DSOP) in the diet of lactating buffaloes on milk and mozzarella cheese yield and characteristics. Methods: Sixteen pluriparous buffaloes distributed into two groups were fed an isoenergetic (0.9 milk forage unit/kg) and isoprotein (149 g/kg dry matter [DM] of crude protein) diet, with or without DSOP. Each animal received 17 kg DM/d. Samples of forages and concentrates were weekly collected and used for duplicate chemical analyses. Individual milk samples from each control were analyzed for chemical and coagulating parameters and daily production of mozzarella cheese was estimated. At the end of the trial, bulk milk of each group was processed to produce mozzarella cheese and chemical (fat, protein, ash, pH) composition, fatty acids composition, carotenoids and tocopherols content were determined. A sensory test was also performed. The oxidative stability was measured on mozzarella cheese and on governing liquid. Results: No significant differences were observed, neither for milk yield and body condition score, nor for milk characteristics. The fat was higher (p<0.05) in mozzarella of DSOP fed group but, saturated fatty acids were lower and unsaturated higher (p<0.01). Furthermore, lower atherogenic (p<0.01), and thrombogenic (p<0.05) indices were found in mozzarella cheese of DSOP fed group. In addition, the administration of DSOP did not affect the mozzarella cheese oxidative stability and no negative effect was found in the sensory properties. Conclusion: No contraindications appeared for the inclusion of DSOP in the diet of lactating buffaloes. Besides, important effects on mozzarella cheese quality were obtained, such as a modification of fat content and attributes with an increment in the mono-unsaturated. Additionally, a lower saturated/unsaturated ratio and atherogenic and thrombogenic indices suggest an improvement of dietetic and nutritional characteristics of mozzarella cheese.

• 한국생활과학회지
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• 제17권6호
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• pp.1225-1236
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• 2008

The purpose of this study is to determine the effect of aromatherapy, showing how the composition handling of aromatherapy and abdominal massage treatment reaches body ingredient transformation. The subjects for this research were total 18 middle-aged females in Seoul; aroma massage group of 7 females, aroma inhalation and water bathe group of 5 females, abdominal massage group of 6 females by jojoba oil without any medical effect. This clinic trial was held from July 1, 2008 to Aug.14, 2008. I held this clinic trial under the same condition after and before this clinic. A standard tape and OLYMPIA 3.5 of S hospital were used at the body measuring for subjects after and before clinic trials. I got Average and standard deviation by data analysis by SPSS Win. Ver.14.0. I did paired t-test for the comparison of before and after, and repeated measure ANOVA for between two groups or among three groups'. The verification was held Duncan Test. The results of this study were as follows: 1. Body mass quotient (F=2.86, p= .063) and Body region (F=1.34, p= .279) among three groups showed no meaningful difference, but weight meaningful difference and aroma massage group showed the greatest difference of body measure change quantity. 2. In change quantity of abdomen girth, Waist circumference and WHR, abdomen girth (F=4.56, p= .012) and Waist circumference (F=4.37, p= .031) showed a meaningful statistical difference. The result of subsequent inspection showed that there was a meaningful difference among three groups and aroma massage group was best. 3. In Cell quantity, Body region quantity and Muscle volume, Body region quantity (F=2.76, p= .182) and Muscle volume (F=3.12, p= .054) showed no difference, but Cell quantity (F=3.79, p= .040) showed a meaningful difference. In the comparison of three groups there was no difference, but aromatherapy group showed more change quantity than any other group. According to the result of this study, the composition handling of aromatherapy and body massage was effective in the decrease of Abdominal fatness and Waist circumference, Weight and the increase of Cell quantity. so I suggest that woman use this therapy in the program of obesity management for her health improvement.

• 한국항해항만학회지
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• 제32권3호
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• pp.257-264
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• 2008

이 연구는 수상에 건설되는 해양건축물의 재산권 공시제도의 문제점을 파악하고 개선안을 제시하기 위한 연구이다. 먼저 해양건축물을 둘러싼 현황을 파악하고 미래를 전망하며 다음으로 해양건축물의 개념과 관련된 법제도를 검토한다. 해양건축물의 재산권 공시제도와 관련하여 현황과 문제점을 파악하며 각종 물건의 공시제도를 검토한다. 마지막으로 해양건축물의 재산권 공시제도 정비방안을 제시한다. 연구 결론으로서 해양건축물 공시제도는 고정식과 부유식 구조물로 나누어 적합한 공시제도를 제안한다. 고정식 구조물은 현행 건축법을 보완 수정하여 부동산등기제도를 활용하며 부유식 구조물은 새로운 법을 제정하여 등록원부와 같은 공적장부를 통한 등록제도를 도입하는 것이 필요하다. 해양건축물이 활성화되고 이를 기반으로 해양산업이 발달하기 위해서는 해양건축물에 관한 소유권 취득과 담보물권 설정 등 재산권 행사를 용이하게 하기 위해 해양건축물의 재산권 공시제도가 속히 마련되어야 한다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.490.2-490.2
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• 2014

Since the general solar cells accept sun light at the front side, excluding the electrode area, electrons move from the emitter to the front electrode and start to collect at the grid edge. Thus the edge of gridline can be important for electrical properties of screen-printed silicon solar cells. In this study, the improvement of electrical properties in screen-printed crystalline silicon solar cells by contact treatment of grid edge was investigated. The samples with $60{\Omega}/{\square}$ and $70{\Omega}/{\square}$ emitter were prepared. After front side of samples was deposited by SiNx commercial Ag paste and Al paste were printed at front side and rear side respectively. Each sample was co-fired between $670^{\circ}C$ and $780^{\circ}C$ in the rapid thermal processing (RTP). After the firing process, the cells were dipped in 2.5% hydrofluoric acid (HF) at room temperature for various times under 60 seconds and then rinsed in deionized water. (This is called "contact treatment") After dipping in HF for a certain period, the samples from each firing condition were compared by measurement. Cell performances were measured by Suns-Voc, solar simulator, the transfer length method and a field emission scanning electron microscope. According to HF treatment, once the thin glass layer at the grid edge was etched, the current transport was changed from tunneling via Ag colloids in the glass layer to direct transport via Ag colloids between the Ag bulk and the emitter. Thus, the transfer length as well as the specific contact resistance decreased. For more details a model of the current path was proposed to explain the effect of HF treatment at the edge of the Ag grid. It is expected that HF treatment may help to improve the contact of high sheet-resistance emitter as well as the contact of a high specific contact resistance.

• 한국건축시공학회지
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• 제17권5호
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• pp.453-463
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• 2017

건물의 고층화와 규모의 증가로 인해 프로젝트 설계단계에서의 시공성을 반영한 엔지니어링 기술의 중요성이 점점 커지고 있다. 특히, 설계단계에서의 가설작업을 위한 설비, 장비 및 공법과 관련된 엔지니어링 기술적용의 노력은 시공성 및 프로젝트 성과 향상에 크게 기여할 수 있다. 이에 본 연구에서는 고층 건축공사의 시공성 향상을 위하여 가설공사를 중심으로 설계단계에 요구되는 시공엔지니어링 업무를 도출하고자 하였다. 우선, 문헌고찰과 전문가 집단면접을 통해 27개의 예비 업무를 도출하였으며, 그 후 설문조사를 통하여 각 업무의 필요성 및 중요도를 분석하였다. 분석 결과, 골조공사 및 양중장비 계획과 관련된 대부분의 업무가 상대적으로 중요한 것으로 분석되었다. 마지막으로 요인분석을 통해 21개의 엔지니어링 업무를 선정하였으며, 이들 업무는 크게 1)골조공사 및 측량/동선계획, 2)양중 및 콘크리트 압송계획, 3)공간구획계획, 4)용수계획, 5)가설건물 및 전력/조명계획의 5개 요인으로 분류되었다. 본 연구의 결과는 설계단계에서 시공엔지니어링 업무를 효과적으로 반영할 수 있는 프로세스 수립을 위한 기초 자료로 활용될 수 있을 것이다.

• Korean Chemical Engineering Research
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• 제44권4호
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• pp.404-409
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• 2006

USY 제올라이트에 이원계의 Pd-Cu 복합촉매를 담지하여 FT-IR 분석기로 밀폐계에서 촉매의 표면반응특성을 조사하였다. 700 ppm의 톨루엔 연소반응은 고정반응기를 이용하여 $80{\sim}220^{\circ}C$에서 수행하였으며 톨루엔을 GC로 분석하였다. 촉매활성은 Pd-Cu/USY > Pd/USY > PdO-CuO/USY > PdO/USY > $PdO/Al_2O_3$의 순서임을 알 수 있었다. 저온연소반응에서 수분이 촉매의 활성에 미치는 영향을 관찰하였고 공기의 공급변화를 통하여 촉매표면에 있는 결정격자의 산소가 반응에 참여 여부를 조사하였다. 환원된 촉매들은 톨루엔의 연소활성에너지로 인해 산화된 촉매에 비해 활성이 높았다.

• Ocean and Polar Research
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• 제25권3호
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• pp.277-286
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• 2003

Nitrification performance of fixed film biofilters using coarse sand, loess bead, or styrofoam beads in biofilter columns 1 meter high and 30cm in diameter were studied at different hydraulic and organic matter loading rates. Synthetic wastewater was supplied to the culture tank in order to maintain desired TAN concentrations in inlet water to biofilters. All the biofilters were conditioned 5 months before start of sampling. TAN and $NO_2-N$ conversion rates increased with an increase in the hydraulic loading rate (HLR). However, the improvement in biofilter performance was not linearly correlated to HLR in styrofoam bead filters. This is mainly due to the characteristics of the styrofoam beads used. TAN conversion rates of sand filters increased with the increase of HLR up to $200m^3/m^2$. per day. No increase in the TAN conversion rate was observed at the highest HLR since flooding on the media surface took place. HLR had a significant impact on the TAN conversion rates in loess bead filter up to the highest HLR tested (P<0.05). TAN conversion rates were much less at organic matter loading rates of 9 and 18kg $O_2/m^3$ per day than those without the addition of organic matter in styrofoam bead filters. The addition of glucose resulted in a reduction of the TAN conversion rate from 540 to 284g $TAN/m^3$ per day. No significant difference of TAN conversion rates between the two organic matter loading rates was found (p<0.05). This indicates that the impact of organic matter on nitrification becomes less and less sensitive with an increase in the COD/TAN ratio. At an organic matter loading rate of 9kg $O_2/m^3$. per day, a great reduction of TAN conversion rates was observed in sand filters and loess bead filters. Clearly, organic matter can be one of the most Important Impacting factors on nitrification. $NO_2-N$ conversion rates showed a similar trend for TAN. Based on the TAN and nitrite conversion rates, styrofoam beads showed the best performance among the three filter media tested. Also, the low gravity and price of styrofoam beads make the handling easier and more cost-effective for commercial application. The results obtained at the highest organic matter loading rates can be used in the biofilter design in recirculating aquaculture system.

• 한국수산과학회지
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• 제2권2호
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• pp.155-160
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• 1969

본 연구는 바지락(Tapes Philippinarum) 서식지의 토양을 물리화학적 방법으로 토성, 구성성분 및 유핵화학성분을 분석하여 본종의 서식밀도와의 관계를 조사하여 바지락서식의 적지요인을 연구하였다. 1. 각력의 조성률은 바지락의 서식밀도와 정상관(r=0.78) 관계가 있으며 $13.5\%$ 이상이 적당하다. 2. 조사의 조성률은 바지락의 서식밀도와 정상관(r=0.73) 관계가 있으며 $23.0\%$ 이상의 함량이 적당하다. 3. 세사의 함양은 바지락의 서식밀도와 정상관(r=-0.42)의 관계가 있으며 $41.5\%$ 이하가 적당하다. 4. 징사의 함량은 바지락의 서식밀도와 정상관(r=-0.68)의 관계가 있으며 $10.0\%$ 이하가 적당하다. 5. 점토분은 바지락의 서식 밀도와 부상관(r=-0.51)의 관계가 있는 것으로 $6.8\%$ 이하의 저토가 적당하다. 6. 바지락 서식지의 간석토는 규반율이 $5.09\~5.60$으로 규산질의 초토이다. 7. 바지락 서식지의 토양 pH, 보수능, 유기물, 총질소, 유효린산, 치환성 Ca, 및 치환성 Mg의 함양은 각각 $6.15\~6.60,\;4.26\~6.86\%,\;0.40\~1.10\%,\;14.0\~27.0ppm,\;0.041\~0.394\%$, 및 $0.009\~0.132\%$이었다.

• Journal of Microbiology and Biotechnology
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• 제25권1호
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• pp.74-80
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• 2015

Skin is the soft outer covering of vertebrates that provides protection from pathogenic infection, physical damage, or UV irradiation, and controls body temperature and water content. In this study, we examined the effects of oral intake of kimchi-derived Lactobacillus plantarum K8 lysates on skin moisturizing. In an in vitro study, we observed that the hyaluronic acid content increased in HaCaT cells treated with L. plantarum K8 lysates. Oral administration of L. plantarum K8 lysates effectively attenuated the horny layer formation and decreased epidermal thickening in DNCB-treated SKH-1 hairless mice skin. The damage to barrier function was reduced after 8 weeks of oral administration of L. plantarum K8 lysates as compared with that in the atopic dermatitis mice. For the test with volunteers, we manufactured experimental candy containing 2.1% L. plantarum K8 lysates, while control candy did not contain bacterial lysate. A significant increase in hydration in the experimental candy-administered group as compared with the control candy-administered group was observed on the face after 4 and 8 weeks, and on the forearm after 4 weeks. Decreases in horny layer thickness and TEWL value were observed on the face and forearm of the experimental group. Together, the in vitro cell line and in vivo mouse studies revealed that L. plantarum K8 lysates have a moisturizing effect. A clinical research study with healthy volunteers also showed an improvement in barrier repair and function when volunteers took L. plantarum K8 lysates-containing candy. Thus, our results suggest that L. plantarum K8 lysates may help to improve skin barrier function.