• Korean Journal of Environmental Agriculture
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• v.20 no.3
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• pp.135-142
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• 2001

Compostable household wastes(mainly food wastes), after waste papers and cardboard being removed, were daily fed into small bins and mixed thoroughly while the air was supplied into the bin. Three small bins were employed: in case I, only recycled compost was composted, after being once fed at the beginning of composting, in case II, compostable household wastes(less than 50 mm) torn roughly by the hands with recycled compost, and in case III, compostable household wastes(less than 2 mm) ground by a kitchen mixer for vegetables with recycled compost. The straight-line was maintained between the wet or the dry residual mass of composting mixture versus composting time date(the coefficient of determination $R^2{\geq}0.98$ for the wet and $R^2{\geq}0.90$ for the dry). The decomposition rate of each composted material was estimated during composting. The total weight reduction rate after 30 days was 67.86% and 66.14% for case II and III, respectively. For case II, the daily weight reduction 6.82% and the daily decomposition rate 8.81% with the composting mixture, but the daily weight reduction rate was 56.43% and the daily decomposition rate 19.26% with only compostable household wastes. For case III, the daily reduction rate was 6.93% and the daily decomposition rate 7.70% with the composting mixture, but the daily weight reduction rate was 53.30% and the daily decomposition rate 22.95% with only compostable household wastes. The physicochemical characteristics of composting mixture did not show much difference between case II and III as was expected.

• Microbiology and Biotechnology Letters
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• v.35 no.3
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• pp.231-237
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• 2007

To support the fermentational superiority of Korean nuruks and maintain the various domestic nuruks, the optimal nuruk production of Andong-Soju, which was designated as an intangible cultural asset of Gyungsangbukdo province from 1987, was investigated. Different thickness of nuruks ($2.2{\sim}5.5\;cm$) were manufactured based on traditional Andong-Soju nuruk method, while the size of round form of nuruk was set to 23 cm. During the 3 weeks maturation, changes of water content, weight, pH, brix, the amount of reducing sugar, sac-charifying activity, viable cell and major microorganisms were determined, Also, ethanol fermentation abilities of the manufactured nuruks were evaluated using 20% glucose medium or 16% starch medium, respectively. Our results indicated that the production of high quality of Andong-Soju nuruk needs $4.0{\sim}5.5\;cm$ thickness and 3 weeks maturation without extraneous yeast addition. These results would be applied to production of homogeneous, and high quality of Andong-Soju nuruk.

• Korean journal of applied entomology
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• v.54 no.4
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• pp.443-448
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• 2015

The attractant effect to Platypus koryoensis (Murayama), an insect vector of Korean oak wilt disease, was determined using a multi-funnel trap and trap logs treated with ethanol and ethanol extract of the bark of the Mongolian oak Quercus mongolica (Fisher). The number of entrance holes in ethanol and bark ethanol extract treatments was higher than that in the control (blank bottle). However, the number of entrance holes in ethanol and bark ethanol extract treatments was not significantly different. The number of entrance holes in the logs increased with increase in diameter of the logs. The lower part of the trap logs had significantly more number of entrance holes than that in the upper part (p < 0.05). The lower part of trap logs tends to be rarely exposed to direct sunlight resulting in desiccation of the logs, which in turn provides good conditions for microbial growth, a food source for P. koryoensis. The results show, that ethanol could be used effectively in the monitoring and maintenance of P. koryoensis because of the cheaper cost of ethanol than bark ethanol extracts, and thus, having a higher economical advantage. Further research of oak bark ethanol extracts is necessary to improve its efficiency.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.44 no.2
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• pp.133-139
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• 2018

Chemically damaged hair is vulnerable to external stimuli in daily life due to the weakened physical properties of the hair strand itself. The purpose of this work was to determine whether chemical conjugation between hair keratin proteins restores tensile strength and thus results inpreventing further deterioration under repeated combing. A model damaged hair tress was produced by a typical perm-process. Then, it was internally crosslinked by the bifunctional crosslinker (3-aminopropyl)triethoxysilane (APTES), via both silane coupling and carbodiimide chemistry. Physical properties, including tensile strength, Young's modulus, and plateau stress, were measured to verify the effect of internal crosslinking, and the existence of crosslinking was verified by Fourier transform infrared (FT-IR) spectroscopy. The degrees of hair breakage and split ends were evaluated by repeated combing-drying tests. Physical properties of chemically damaged hair were restored by internal crosslinking. Successful crosslinking of APTES via both silane coupling and carbodiimide chemistry was verified by FT-IR spectra. Prevention of breakage and split ends after repeated combing with heat was observed. Human hair can be weakened by chemical damage including perm-processing, so restoring such properties is a major issue in the hair care industry. This work shows that internal crosslinking of damaged hair via chemical conjugation would be a potent method to restore the healthy hair.

• Journal of dental hygiene science
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• v.2 no.2
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• pp.105-113
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• 2002

This study was aimed to investigate the practice on the infection control and dental waste disposal in dental clinic. The data used in this study had been collected in 100 dental clinics located in Seoul city from August to October, 2001. It was shown that examination instruments, oral surgery instruments, and periodontal instruments were almost sterilization in dental clinic. It was high in the recognition of individual protection but it was low in the degree of practice. Therefore, the practice in infection control is very important to dental team for safety of patients and operators.

• Journal of Life Science
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• v.16 no.7 s.80
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• pp.1158-1163
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• 2006

Bisphenol A (BPA), 2,2-bis(4-hydroxyphenyl) propane, has been widely used as a monomer for production of epoxy resins and polycarbonate plastics, and final products of BPA include adhesives, protective coatings, paints, optical lens, building materials, compact disks and other electrical parts. Since BPA is a toxic chemical to elicit acute cell cytotoxicity and chronic endocrine disrupting activity, the degradation of BPA has been focused during last decades. To overcome the problem of photo-, and chemical-degradation of BPA, in this study, a bacterium that is able to biodegrade BPA, was isolated. The bacterium, isolated froln the soil of plastic factory, was identified as Acinetobacter calcoaceticus (strain BP-2) based on physiological and 16S rDNA sequencing analysis. A. calcoaceticus BP-2 was able to grow in the presence of $1140{\mu}g\;ml^{-1}$ BPA. Biodegradation experiments showed that BP-2 mineralized BPA via 4-hydroxybenzoic acid and 4-hydroxyacetophenone, and average degradation rate was $53.3{\mu}g\;ml^{-1}\;day^{-1}$ under optimal conditions (pH 7 and $30^{\circ}C$). In high density resting cell $(3.5g-dcw.1^{-1})$ experiments, the maximal degradation rate was increased to $89.7{\mu}g\;ml^{-1}\;h^{-1}$. Our results suggest that BP-2 has high potential as a catalyst for practical BPA bioremediation.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.28 no.2
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• pp.5-34
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• 2017

This study measured greening level on the 978 public libraries nationwide, making and distributing questionnaires based on green library evaluation indicators developed to measure the greening level of public libraries. As a result of analyzing the averages by evaluation area, among the green library evaluation areas, the whole average of the library resources was the highest by 1.93, and followed by land use and traffic 1.81, indoor environment 1.30, management of water circulation 1.20, etc. The greening evaluation area which shows the best strength in the surveyed public libraries, was the area of the library resource, and it turned out that it use spaces effectively like effective use of the entire area, effectiveness of conservation of books, use and management of eco-friendly products etc., or use the equipments in eco-friendly way which are purchased or used frequently in the libraries, and, as for the land use and traffic area, most of the libraries had bicycle racks, and chose the location of the libraries, considering accessibility to public transportation and a distance between central urban area and libraries. Also, it turns out that, in the area of materials and resources, most of the libraries were equipped with hand dryers and rolling towels and maintained the eco-friendly view.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.346-346
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• 2007

압전세라믹 재료는 현재 압전 변압기, actuator, transducer, sensor, speaker 등에 광범위하게 이용이 되고 있다. 이 중에서 압전세라믹 소결체를 이용한 스피커의 제조는 가공이 까다롭고, 대형의 크기로 제작 시 소자가 깨지는 등의 많은 제약을 받고 있으며, 저음 특성이 떨어져 응용 범위가 한정되어 있다. 따라서 최근에는 이러한 단점을 극복하기 위하여 세라믹/고분자 복합체를 이용한 필름 스피커를 제작하고자 시도하고 있다. 이러한 세라믹/고분자 0-3형 압전 복합체를 이용할 경우, 제품의 경량화를 실현할 수 있고, 크기나 환경의 영향을 거의 받지 않으므로, 고기능성 스피커로의 응용에 적합할 것으로 보인다. 따라서 본 연구에서는 PZT계의 세라믹와 PVDF, PVDF-TrFE, Polyester, acrylic resin 등의 여러 고분자 물질과의 복합체를 제조하여 압전특성을 평가하였다. 본 실험은 먼저 $(Pb_{1-a-b}Ba_aCd_b)(Zr_xTi_{1-x})_{1-c-d}(Ni_{1/3}Nb_{2/3})_c(Zn_{1/3}Nb_{2/3})_dO_3$ (이하 PZT라 표기)의 최적화 조성을 선택하여, $1050^{\circ}C$에서 소결된 분말을 48시간 ball milling방법 로 약 $1{\mu}m$ 크기로 분쇄하였다. 고분자 물질들은 알맞은 용제들을 선택하여 녹였다. 그 다음 소결된 PZT분말과 고분자를 50:50, 60:40, 65:35, 70:30등의 무게 분율로 혼합하고, 분산제, 소포제 등을 첨가하여 3단 roll mill을 이용하여 충분히 분산시켜 페이스트 (Paste)를 제조하였다. 제조된 페이스트를 ITO가 코팅된 PET필름 위에 스크린 프린팅 법을 사용하여 인쇄하여 $120^{\circ}C$에서 5분간 건조하였다. 코팅된 복합체의 두께는 약 $80{\mu}m$ 정도로 측정되었다. Ag 페이스트를 이용한 상부 전극 형성에도 스크린 프린팅 법을 적용하였다. 이를 $120^{\circ}C$에서 4 kV/mm의 DC 전계로 분극 공정을 수행한 후 전기적 특성을 평가하였다. 유전특성을 조사하기 위해서 LCR meter (EDC-1620)를 사용하였고, 시편의 결정구조는 XRD (Rigaku; D/MAX-2500H)을 통해 분석하였으며, 전자현미경(SEM)을 이용하여 미세구조를 분석하였다. 압전 전하상수$(d_{33})$ 값은 APC 8000 모델을 이용하여 측정하였다. PZT의 혼합비가 증가할수록 비유전율 및 압전 전하 상수 등의 전기적 특성이 증가되었다. 또 여러 고분자 물질 중에서 PVDF-TrFE 수지가 가장 우수한 특성을 보였다. 이는 PVDF-TrFE 수지가 압전성을 나타내기 때문인 것으로 판단되었다.

• Korean journal of food and cookery science
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• v.21 no.2 s.86
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• pp.171-179
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• 2005

This study was investigated on antioxidative and antimicrobial activities of PSW(pomegranate seed water extract), PSE(pomegranate seed ethanol extract) and PSO(pomegranate seed oil). The extraction yields of PSW, PSE and PSO were 28.9, 13.0 and $4.9\%$, respectively. Total phenol contents of PSW, PSE and PSO were 47, 78 mg/g(dry basis) and 40 mg/g, respectively. Electron donating abilities of PSW, PSE and PSO at 1,000 ppm were 18.8, 28.5 and $9.7\%$, respectively. Antioxidative activities in Iinoleic acid substrates at 500 ppm were in order of PSE > $\alpha-tocopherol$ > PSW > PSO. Antioxidative activities in Iinoleic acid emulsion substrates at 200 ppm were in order of $\alpha-tocopherol$l > PSE > PSW > PSO. In antimicrobial activity, PSO showed growth inhibition effect against Micrococcus luteus, Salmonella enteritidis and PSW showed growth inhibition effect against Bacillus cereus, Escherichia coli. Whereas antimicrobial activity of PSE was not observed. The nitrite-scavenging abilities of PSW, PSE and PSO at 2,000 ppm were 27.5, 23.7 and $39.6\%$, respectively. And the SOD-like activities of PSW, PSE and PSO at 1,000 ppm were 15.9, 34.9 and $0.10\%$, respectively.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.1
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• pp.409-414
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• 2021

Tightness performance that blocks compartments is important for surface ships to achieve superior mission performance and survivability in combat environments. To meet the above requirements, airtightness of the structural elements and the appropriate strength to specific areas are checked during a test run after ship construction. In particular, air tests of compartments adjacent to the water surface are performed. In an air test, air is injected into the compartment up to the test pressure of the test memo. The pressure drop value is checked after 10 minutes to determine if the requirements of the corresponding area are satisfied. In summer, however, when the influence of the outside temperature is large, a phenomenon in which the internal pressure increases during the air test was identified. This phenomenon reduces the reliability of the test result. Therefore, a system was designed to compensate for temperature changes in the compartments through this study. The developed system calculates the amount of pressure change caused by a temperature change in the compartment and outputs a correction value. The pressure change was calculated using the ideal gas equation, reflecting the maintenance, increase, and decrease in temperature during the test process. A comparison of the calculated pressure correction value with the database of NIST REFPROP revealed a difference of 0.126% to a maximum of 0.253%.