• 한국의류학회지
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• 제26권2호
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• pp.349-354
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• 2002

In order to decolorize the reactive dye wastewater, we investigated the dye-adsorption ability of chitin, which was natural polymer obtained from shrimp shell. Chitin particle(less than 250 ${\mu}{\textrm}{m}$n) was prepared from shrimp shells in the processes of decalcification in aqueous hydrochloric acid solution and deproteination in aqueous sodium hydroxide solution. The particle size of chitin was controlled to less than 250 ${\mu}{\textrm}{m}$. Three tripes of the reactive dyes-C.I. Reactive Red 120, C.I. Reactive red 241 and C.I. Reactive Black 5-were used. Dye adsorption ability of chitin was investigated by dipping the particle in the dyebaths of concentration of 0.0l%, 0.03% and 0.05% for various periods of time(1,3,5, 10,20,40,80,160minutes). The influence of addition of salt(Na$_2$SO$_4$) and alkali to the dyebaths on dye-absorption was also investigated. We obtained the following results fur the dye-absolution ability of chitin in the dyebaths of three types of reactive dyes. 1) The amount of dye uptake by chitin was increased by addition of salt to the dyebaths. 2) As the concentration of alkali became higher than 3g/I, the amount of dye uptake by chitin was increased. Chitin showed good dye-adsorption ability, when the alkali concentration was high. 3) Chitin showed equal dye uptake in the three types of dyebaths when the dye concentration was 0.0l%. Over 90% of dyestuffs was adsorbed from the dyebaths in ten minutes. When the dye concentration was higher, better adsorption ability was showed in a dye bath of Reactive black 5 than in the others. When the dye concentration was 0.03%, 90% of Reactive red 120 and Reactive red 241 was adsorbed in 40 minutes and the same of Reactive black 5 in 10 minutes. When the dye concentration was 0.05%, 9()% of Reactive red 120 was adsorbed in 80 minutes, and Reactive black 5 in to minutes.

• 한국식품영양학회지
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• 제11권4호
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• pp.426-430
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• 1998

This study was conducted to investigate electron donating ability, antioxdative activity and nitrite-scavenging effect of solvent extracts from Gyrophora esculenta. The phenolic compounds of diethylether, butanol, petroleum ether and hexane extracts were 194.20$\mu\textrm{g}$/ml, 98.80$\mu\textrm{g}$/ml, 1.60$\mu\textrm{g}$/ml and 0.20$\mu\textrm{g}$/ml, respectively. Electron donating abilities of diethyleter and butanol extracts from Gyrophora esculaenta were 80.79% and 72.81%, respectively. Absorption of DPPH by diethyleter and butanol extracts sharply increaed at initial stage. Antioxidative activities of fiethylether and butanol extracts by peroxide values are rather high as compared to those of control, but low s compared to those of BHA. Nitrite-scavenging abilities of diethylether, butanol and petroleum ether from Gyrophora esculenta were 96.07%, 77.39% and 15.07%, respectively.

• 디지털융복합연구
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• 제9권6호
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• pp.255-266
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• 2011

본 연구는 기업의 컨설팅 성과에 있어서 컨설턴트의 역량이 미치는 영향에 관해서 알아보고 이러한 관계에 있어서 프로젝트 매니저의 역량이 얼마나 조절효과가 있는가를 중소기업을 대상으로 분석해 보았다. 결과적으로 프로젝트 매니저의 역량을 중요한 조절 효과가 있는 것으로 나타났으나, 중소기업의 프로젝트의 규모적인 한계로 인해 관리능력은 유의하지 않은 결과가 나타났다.

• Corrosion Science and Technology
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• 제4권1호
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• pp.15-18
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• 2005

Hydroxyapatite(HAp) was synthesized using the waste sludge from semiconductor process and used as an anticorrosive pigment. The water absorption of coating pigmented with anticorrosive pigment and the corrosion at interface between coating and substrate were monitored using AC impedance techniques. The anticorrosive performance of HAp was compared with those of red lead(RL) and zinc potassium chromate(ZPC), which have been known as representative anticorrosive pigments. The amount of absorbed water in ZPC- and HAp- pigmented coatings was much higher compared to that in RL-pigmented and unpigmented film. However, it seems that the water absorbed into HAp- or ZPC-pigmented film is beneficial to anticorrosive function. The anticorrosive performance of HAp is superior or at least comparable to those of ZPC and RL. The excellent anticorrosive properties of HAp can be explained by its passivating ability, caused by the reaction of the soluble component of HAp with Fe to form iron phosphate in the presence of water.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1998년도 가을 학술발표대회 논문집(III)
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• pp.797-802
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• 1998

Fiber reinforcement can significantly improve the properties of concrete. Particulary, toughness or energy-absorbing ability of fiber reinforced concrete is frequently higher than that of unreinforced concrete. Toughness is a measure of energy absorption capacity and used to characterized fiber reinforced concrete's ability to resist fracture when subjected to static, dynamic and impact loads. However, the current standard methods of characterizing the toughness of fiber reinforced concrete have proven to be some inadequate and problems and have caused a great deal of dissent and confusion. This study research some of the inadequate and problems with these toughness measurement methods and proposes the evaluation method for Fiber Reinforced Concrete toughness.

• 대한방사선기술학회지:방사선기술과학
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• 제4권1호
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• pp.37-44
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• 1981

It is a experimental report to investigate optimum exposure technics in angiocardiography. Because of x-ray absorption and rapid voluntary motion in the heart region, it bound that discrimination ability of the exposed film is being decreased in ACG To circumvent these disadvantage it must be necessary to use short time exposure technics and also high capacity equipment in ACG. But in the case of using the low tube voltage to improve contrast on the exposed film, it will be result in a many difficulties in interpretation of the image due to increased contrast in vertebral images. Therefore the ranges 80 kVp to 90 kVp of could be suitable for the purpose of good contrast and an excellent discrimination ability and under this circumstance the optimum grid ratio for ACG was 8:1 to 12:1.

• 중소기업연구
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• 제43권3호
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• pp.91-117
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• 2021

본 연구의 주 목적은 중국 제조업 중소기업의 국제기업가 지향성이 수출 성과에 미치는 영향을 실증 분석 하고 함의를 도출하는 것이다. 이를 위해 본 연구에서는 중국 제조업 수출 기업을 대상으로 총 183개의 기업 데이터를 실증분석에 사용하였다. 본 연구의 연구결과를 요약하면, 첫째, 국제기업가 지향성은 수출 성과에 유의한 정(+)의 영향을 미치는 것으로 나타났고, 둘째, 국제기업가 지향성은 흡수역량에 유의한 정(+)의 영향을 미친다. 셋째, 흡수역량은 수출성과에 유의한 정(+)의 영향을 미치는 것으로 나타났으며, 넷째, 환경 역동성과 네트워크 역량이 강할수록 국제기업가지향성과 수출성과의 관계는 더욱 강화되는 것으로 나타나며, 마지막으로 국제화기간이 길수록 흡수역량과 수출성과의 관계는 약화되는 것으로 나타났다. 본 연구의 시사점을 정리하면 다음과 같다. 중국 중소기업은 혁신적이고 진취적이고 위험을 감수할수록 수출성과가 더욱 향상되고, 유사한 경쟁기업의 경영방식을 흡수하는 능력이 향상된다는 것을 시사한다. 또한 중소기업 경영자는 국제기업가지향성을 통한 수출성과를 향상 시키기 위해서는 네트워크 역량을 지속적으로 강화 시켜야 하고, 역동적인 환경에서 이러한 관계는 더욱 강화되는 것으로 나타났다. 나아가서 기업 경영자의 흡수 역량이 수출성과에 미치는 영향은 기간이 지날수록 영향력이 약화됨을 보여주고 있다.

• 대한소아치과학회지
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• 제51권2호
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• pp.149-164
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• 2024

This study compared the solubility, water absorption, dimensional stability, release of various ions (hydroxyl, calcium, sulfur, strontium, and silicon), and cytotoxicity of light-cured resin-modified pulp-capping materials. Resin-modified calcium hydroxide (Ultra-blend^TM plus, UBP), light-cured resin-modified calcium silicate (TheraCal LC^TM, TLC), and dual-cure resin-modified calcium silicate (TheraCal PT^TM, TPT) were used. Each material was polymerized; solubility, 24-hour water absorption, and 30- day dimensional stability experiments were conducted to test its physical properties. Solubility was assessed according to the ISO 6876 standard, and 24 hours of water absorption, 30 days of dimensional stability were assessed by referring to the previous protocol respectively. Eluates at 3 and 24 hours and on 7, 14, and 28 days were analyzed according to the ISO 10993-12 standard. And the pH, Ion-releasing ability, cell proliferation rate, and cell viability were assessed using the eluates to evaluate biochemical characteristics. pH was measured with a pH meter and Ion-releasing ability was assessed using inductively coupled plasma atomic emission spectrometry (ICP-AES). Cell proliferation rate and cell viability were assessed using human dental pulp cells (hDPCs). The former was assessed by an absorbance assay using the CCK-8 solution, and the latter was assessed by Live and Dead staining. TPT exhibited lower solubility and water absorption than TLC. UBP and TPT demonstrated higher stability than TLC. The release of sulfur, strontium, calcium, and hydroxyl ions was higher for TLC and TPT than for UBP. The 28-day release of hydroxyl and silicon ions was similar for TLC and TPT. TLC alone exhibited a lower cell proliferation rate compared to the control group at a dilution ratio of 1 : 2 in cell proliferation and dead cells from Live and Dead assay evaluation. Thus, when using light-cure resin-modified pulp-capping materials, calcium silicate-based materials can be considered alternatives to calcium hydroxide-based materials. Moreover, when comparing physical and biochemical properties, TPT could be prioritized over TLC as the first choice.

• 자원환경지질
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• 제9권3호
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• pp.165-168
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• 1976

Zeolites are aluminosilicates with a three dimensional framework structure enclosing pores occupied by cation and water molecules, both of which have considerable freedom of movement within certain limits. The ability of zeolites to exchange cation is one of the mere useful of their characteristics. The ion exchange condition of zeolites strongly affects absorption as well as other properties. The application, techniques of identification and evaluation of clinoptilolite, chabazite, mordenite and phillipsite are reviewed.

• 기술사
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• 제45권3호
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• pp.36-39
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• 2012

Roof gardens/Rooftop farm are most often found in urban environments. Plants have the ability to reduce the overall heat absorption of the building which then reduces energy consumption. Plant surfaces however, as a result of transpiration do not rise more than $4-5^{\circ}C$ above the ambient and are sometimes cooler. As Urban agriculture in an accessible rooftop farm, space becomes available for localized small-scale urban agriculture, a source of local food production. An urban garden can supplement the diets of the community it feeds with fresh produce and provide a tangible tie to food production.