• Journal of Microbiology and Biotechnology
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• 제24권2호
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• pp.280-286
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• 2014

Four thermophilic bacterial species, including the iron-reducing bacterium Geobacillus sp. G2 and the sulfate-reducing bacterium Desulfotomaculum sp. SRB-M, were employed to integrate a bacterial consortium. A second consortium was integrated with the same bacteria, except for Geobacillus sp. G2. Carbon steel coupons were subjected to batch cultures of both consortia. The corrosion induced by the complete consortium was 10 times higher than that induced by the second consortium, and the ferrous ion concentration was consistently higher in iron-reducing consortia. Scanning electronic microscopy analysis of the carbon steel surface showed mineral films colonized by bacteria. The complete consortium caused profuse fracturing of the mineral film, whereas the non-iron-reducing consortium did not generate fractures. These data show that the iron-reducing activity of Geobacillus sp. G2 promotes fracturing of mineral films, thereby increasing steel corrosion.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2017년도 추계 학술논문 발표대회
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• pp.32-33
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• 2017

In order to improve the flow performance of high performance concrete, use of high performance water reducing agent and low viscosity type water reducing agent is a study of suitable range of use due to side effects. in this study, we aimed at reducing viscosity and yield value using high performance water reducing agent and low viscosity type water reducing agent, and this was evaluated using a rheometer. as a result of analysis of viscosity and yield value, it was found that the high performance water reducing agent has higher reduction effect than the low viscosity type water reducing agent. however, the larger the viscosity lowering effect is, the lower the usable range is, compared to general high performance water reducing agents, and it was found that sufficient consideration for this judgment of appropriate quantity is necessary.

• 복식문화연구
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• 제24권6호
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• pp.777-787
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• 2016

This study was carried out in order to provide useful data for planning fabrics of summer eco-friendly fashion products. The fabrics used in this study were four cellulose fibers: cotton, cotton/mulberry blended, flax, and flax/lyocell blended. Dyeing with natural indigo was carried out under three different reducing conditions (i.e., general, eclectic, and eco-friendly) that have different reducing agent and pH levels, and hydrosulfite and glucose were used as a reducing agent. The dye uptake (K/S value) of fabrics dyed with natural indigo by a reducing condition was the highest at 660nm. Regardless of the fabrics, dye uptake was the highest under the general reducing condition and the lowest under the eco-friendly reducing condition. Under different reducing conditions, the dye uptake of natural indigo fabrics with the maximum absorption wavelength indicated a difference. The colorfastness of cellulose fabrics that were dyed with natural indigo had a rate of 4 to 5 except for rubbing fastness, which indicated good colorfastness. Additionally, natural indigo-dyed cotton and flax fabrics had good antibiosis. When the color characteristics of fabrics dyed with natural indigo were measured, all of the three reducing conditions created purple blue (PB) colors, and the color characteristics of dyed fabrics by reducing condition and fabric showed significant differences.

• 여성건강간호학회지
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• 제24권4호
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• pp.423-434
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• 2018

Purpose: To investigate factors that affect behaviors of reducing exposure to endocrine disrupting chemicals (EDCs) in breastfeeding mothers. Methods: Subjects were 166 breastfeeding mothers who were recruited from January 25 to April 15, 2018. The questionnaire consisted of items associated with behaviors of reducing exposure to EDCs, attitude to behaviors of reducing exposure, subject norms of behavior of reducing exposure, and perceived behavior control. Data were analyzed by t-test, ANOVA, Pearson correlations, and stepwise multiple regression. Results: Factors influencing behaviors of reducing the exposure to EDCs were attitude toward behaviors of reducing exposure, perceived barrier, and period of lactation. The more positive the attitude toward behaviors of reducing exposure was, the lower the perceived barrier. The longer the feeding period, the higher the behaviors of reducing the exposure to EDCs. Conclusions: To enhance behaviors of reducing the exposure to EDCs, it is necessary to develop a positive educational program in breastfeeding department to improve attitude toward behaviors of reducing the exposure to EDCs, decrease perceived barrier, and increase the breastfeeding period.

• 한국직업건강간호학회지
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• 제9권2호
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• pp.132-142
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• 2000

This paper tried to understand the effects of alcohol-reducing program on drinkings behaviour of workers on works under 5 employees. For these, this paper understood a change of drinkings custom and degree of alcohol-reducing strategy practice by enforcement of alcohol reducing program over 7 times during 3 months Reaults from analyses are as follows 1) A health problems related to drinkings were a chronic fatigue and indigestion, 15.5% was over 5 items among items related to liver disease. 2) The subjector of investigation all was involved over 2 items among items that a drinking custom must be collecred. 3) The change of drinkings custom between before and after on enforcement of alcohol reducing program showed a effective difference. 4) For a degree of the alcohol-reducing strategy practice, "reducing drinkings days" was 82.9%. "bearing drinkings impulse" 70.7%, "exchanging drinkings custom" 56.1%, "avoiding drinkings friends" 51.2%, Yet, "avoiding drinking place" and "preparing leisure activity to exchange drinkings" showed a low practice ratio. 5) For correlation between drinkings drinkings behaviour and degree of alcohol-reducing strategy practice, the more drinkings times before program paticipatance the higher alcohol-reducing strategy practice, alcohol dependency and drinkings times, alcohol-reducing strategy and drinkings times, befere drinking custom had an effective negative corelation, after drinkings custom and alcohol-reducing strategy a strong effective positive corelation. 6) workers writing drinkings paper decreased drinkings times. Implications from results are as follows The alcohol-reducing program is necessary to works under 5 employees, and needs to he operated continously. Especially, in works under 5 emplyees, the alcohol-reducing programt needs to be operated by firm or government.

• 가정과삶의질연구
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• 제27권4호
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• pp.141-160
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• 2009

Recently, some policies for reducing standby power, which has quite an effect on electricity consumption, have been employed all over the world. This study surveys the present condition of standby power for major electric home appliances during three years and analyzes the result of technical development reducing standby power. It presents how the industry paid attention to applying the technique of reducing standby power to electric appliances and how it affects the product's energy efficiency. We survey the standby power's change for six items, which were selected from the major electric appliances available on the market. It analyzes the difference of standby power consumption between appliances with a standby power reducing technique and those without during the latest three years. The amount of the average standby power is also compared. The comparison data confirms that the industry's effort and application of reducing standby power contribution has contributed to increasing an appliance's energy efficiency. This study restricted the analyzed items to six appliances, which has been a low volunteered involvement in the standby power reducing program. It is important for reducing standby power consumption of appliances because it contributes to saving electric energy at home and abroad. The development of the standby power reducing technique is needed for more appliances. Along with the development of the standby power reducing technique in the industrial field, it also necessary for consumers to enlarge their understanding of standby power reduction for economic, social, and environmental values.

• 한국농공학회지
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• 제24권2호
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• pp.67-75
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• 1982

A study on the effect of water reducing agent on the various characteristics of concrete has been conducted. The experimental results of the study are summarized as follows. 1. Slump test for the concrete added water reducing setretarding agent in proper quantity have been conducted. According to the test results, the decreasing rate of slump value become bigger than plain concrete with increase of the unit weight of cement and elapse of time 2. In case the proper quantity content of maximum compressive strength in Fig. 5 of water reducing set retarding agent is added, unit weight of water is decreased about 15% or so as compared with plain concrete. with the increase of water reducing set accelerating agent content unit weight of water is decreased much more, And other hand, amount of air entraining shows the increasing tendency with the increase of water reducing agent content. 3. The adding rate of water reducing agent which produce maximum strength shows that WR-CH and WR-SA which is water reducing set-starding agent is 0.2% and WR-CO is 0.5% and that WS-PO which is water reducing set accelerating agent is 0.5 4. compressive strength jof the concrete made of sulfate resistant cement shows less than the strength of normal portland cement at initial strength but the strength of both cement shows almost same at curing age of 28 days. 5. when proper quantity of water reducing set retarding agent is used, boned strength is increased about 15% at curing age of 28days. 6. According to the result of durability test, dynamic young's mudulus of elasticity at plain concrete is decreased about 50% as compared with initial step at 300 cycle of freezing and thawing after curing age of days. on the contarary the concrete used water reducing agent is decreased less than 7%.

• 한국산학기술학회논문지
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• 제17권4호
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• pp.296-302
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• 2016

콘크리트의 내구성 저하로 인한 균열의 보수 및 보강에 소요되는 비용은 콘크리트 구조물의 유지비용 증대로 연결되어 균열발생 저감에 대한 연구가 요구되고 있다. 특히, 전력공급용 시설인 전력구의 경우 지하 매설물이므로 보수 및 보강은 경제적으로 큰 부담이 된다. 그러므로 지하매설 전력구의 경우 효과적인 균열 저감 방안이 설계 초기단계부터 요구되어진다. 본 연구는 전력구용 저수축 콘크리트 제조를 위한 수축저감제 개발의 일환으로 수축저감제 사용 콘크리트의 초기 강도 개선을 위해 TEA를 검토하였다. 검토결과, TEA를 수축저감제의 3% 사용할 경우 조기 강도가 크게 개선되었으며, 수축저감 효과도 우수한 것으로 확인되었다. 또한, TEA 3 %에 수축저감제 2.0 % 혼합하여 적용하였을 경우 압축강도 특성 및 건조수축 길이변화 실험결과에서 가장 우수한 것으로 나타나 수축저감제로서의 가능성을 확인하였다. 추후 수축저감제의 범용적인 적용성 검토를 위하여 수축저감제의 사용재료 변화 등에 대한 다양한 재료변수 요인 검토를 통하여 수축저감제의 성능 검토가 필요할 것으로 사료된다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.2844-2851
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• 2011

The purpose of this study is to set up an acoustic prediction technique and to perform the IL test of scale down noise reducing device for the development of the noise reducing device as the development of 400km/h class high speed train. First of all, the IL prediction of noise reducing device was performed with the 2D BEM method. And the noise test of scale down noise reducing device in anechoic chamber was performed for the verification of acoustic prediction technique and IL performance evaluation. As the results, the acoustic prediction technique for the development of noise reducing device was verified because the averaged IL difference between prediction and test is in 2dB(A). And the measured IL value of noise reducing device is less than 2dB(A), and additional IL with polyester absorption material is increased about 0.5dB(A).

• 동력기계공학회지
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• 제14권1호
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• pp.47-52
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• 2010

In this study, Finite Element Analysis have been adopted to analyze reducing stress effect and used to induce the sensitivity of design parameter on various techniques which was used for reducing stress. And so it can be utilized as a data to design on similar model. The effect of reducing stress with respect to change of relief groove radius can be increased by 27.3~18.2 % more than radius of fillet. And if a shoulder fillet radius is larger, additional reducing stress by relief groove radius is not obtained. And there was only little effect on reducing stress by changing the center point of groove radius along horizontal direction. In the case that undercut radius is 1.5mm, Max. Equivalent stress is reduced by 5.71% under bending force and 11.11% under torsion. The best effect of reducing stress at undercut model was yielded when the undercut radius is a forth of difference of stepped shaft radius.