• Journal of Ginseng Research
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• 제34권3호
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• pp.227-236
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• 2010

The objective of this study was to evaluate the potential use of ginseng leaf as a cosmetic material. In this research, we employed enzymatic treated ginseng leaf by using Ultraflo L to improve the recovery of ginsenosides from the ginseng leaf and studied the biological activities and skin safety of the enzymatic treated ginseng leaf for use as a cosmetic material. The total ginsenoside contents of the non-enzymatic treated ginseng leaf (NEGL) and Ultraflo L treated ginseng leaf (UTGL) were 271 and 406 mg/g, respectively. The level of metabolite ginsenosides (sum of Rg2, Rg3, Rg5, Rk1, compound K, Rh1, Rh2, and F2) was higher in UTGL (93.1 mg) compared to NEGL (62.4 mg) in one gram ginseng leaf extract. The increase in amounts of ginsenoside types in UTGL compared to NEGL was generally 140% to 157%. UTGL exhibited relatively higher 2,2-diphenyl-2-picrylhydrazyl hydrate ($IC_{50}$, 2.8 mg/mL) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt ($IC_{50}$, 1.6 mg/mL) radical scavenging activities compared to NEGL (4.8 mg/mL and 2.2 mg/mL). The UTGL group showed normalized hydrogen peroxide, lipid peroxidation and visual wrinkling grade induced-UVB exposure. The UTGL did not induce any adverse reactions such as erythema and edema on intact skin sites; however, some guinea pigs treated with UTGL on abraded skin sites showed very slight erythema. The primary irritation index (PII) score of UTGL was 0.05 and it was classified as a practically non-irritating material (PII, 0 to 0.5). In skin sensitization tests with guinea pigs, UTGL had a positive rate of skin sensitization at 40%, and the mean evaluation score was 0.4.

• 콘크리트학회논문집
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• 제17권6호
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• pp.1011-1018
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• 2005

액상 숏크리트 급결제(알칼리 알루미네이트, 2종의 알카리프리)가 시멘트 계의 수화 특성에 미치는 영향을 조사했다. 새로운 알카리프리계 숏크리트용 급결제(AF2)를 적용할 경우 기존의 알칼리 알루미네이트 급결제에 비해 초결, 종결 시간은 단축되었고, 1일 압축 강도는 유사했다. 12시간 경과된 모르타르 시편의 압축 강도는 알칼리 급결제가 첨가된 시편이 가장 높았으나, 이후 최종 강도는 알칼리 급결제를 첨가한 시편이 가장 낮았다. 그러나 알카리프리가 첨가된 AF1, AE2 시편의 압축 강도는 28일까지 plain과 유사했다. XRD와 DSC 분석을 통해 알칼리계 급결제는 주로 수산화칼슘, 알카리프리계 급결제는 에트링자이트 결정 성장으로 응결이 촉진된 것을 확인했다.

• 콘크리트학회논문집
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• 제17권6호
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• pp.1019-1024
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• 2005

4종의 콘크리트용 화학 혼화제(리그노 술폰산, 나프탈렌 술폰산 축합물, 멜라민 술폰산 축합물, 폴리카복실레이트계)가 시멘트 수화 반응에 미치는 영향성을 평가하고자, 각각의 고유동화제들이 적용된 시멘트페이스트 경화 시편을 활용해 X-선 회절분석(XRD), 주사전자현미경(SEM), 그리고 열분석(DSC) 분석을 실시하였다. 고유동화제를 사용하지 않은 plain과 비교해 고유동화제를 첨가한 시편의 경우, 고유동화제의 종류 및 사용량에 관계없이 3일까지 수화 반응은 지연되었으나, 이후 재령에서는 고유동화제를 사용하지 않은 plain과 유사한 경향성을 보였다. 특히 고유동화제 사용량이 높아질 경우 수화 지연성은 커졌고, 리그노 술폰산, 폴리카복실레이트, 멜라민, 나프탈렌 술폰산 축합물 순으로 시멘트페이스트 초기 수화를 지연시켰다. 그러나, 이들 고유동화제를 사용할 경우, 시멘트의 분산성을 개선시켜 수화 생성물이 보다 치밀하고 균일했다.

• 대한소아치과학회지
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• 제24권4호
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• pp.823-829
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• 1997

The patients visiting pediatric dental office have been being younger than the previous, and they were often combined with systemic disease. But, we aren't able to perform the verbal communication, because of their impediment and youthfullness. And, we can't carry out the behavior control via physical restraint, as the developed social structure and the attitude of children and their parents. So, the importance and concerning of conscious sedation using sedative medicine are increased by time and time. Among the various conscious sedation, Chloral Hydrate and Nitrous Oxide inhalation are most popularly used, and barbiturates, benzodiazepine, opioids and hydroxyzine are used often. But, these medications have some side-effects and adverse reactions, may be failed to sedate the children. And limited use of medically compromised patients, especially for ASA class III, IV or more dangerous patients. We, the Department of Pediatric Dentistry, Chosun University have met some dangerous situation due to unfavorable pharmacogenic reactions, but we can control the situation and get well healed results. The below results are common situations and their solutions during conscious sedation. 1. By the intravenous administration, thrombophlebitis is the most common side-effects, but it may be healed with time without any special treatment. 2. Under the definitive guidelines about conscious-sedation, we can perform a safe conscious sedation for ASA class III patients. 3. When adversed reaction of Benzodiazepine is occured, it could be cared effectively with benzodiazepine antagonist, named Flumazenil.

• 한국지반환경공학회 논문집
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• 제13권4호
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• pp.53-59
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• 2012

본 연구에서는 지오폴리머계 그라우트재(HIT)의 강도 및 내구성 특성을 분석하기 위하여 일축압축강도시험, SEM, 공시체 표면변화관찰 및 용탈시험을 실시하였다. 일축압축강도시험 결과, HIT의 경우 초기강도가 높고, 재령일이 경과할수록 강도가 증가하는 경향을 보였으나, SGR과 LW 경우 재령 28일 이후 강도가 감소하는 경향을 보였다. 이는 SEM 결과와 일치하였으며, HIT의 경우 지속적인 수화반응을 통하여 밀실한 형태의 C-S-H 수화물이 다수 분포함을 확인할 수 있어 물유리계 재료보다 강도 및 내구성이 우수한 칼슘실리케이트 수화물을 형성함을 알 수 있었다. 또한 공시체의 표면변화 및 용탈시험 결과에서도 양생 6개월이 지난 시점에서 HIT의 경우 양호한 표면을 유지했으며 중량감소율도 극히 미미했다. LW, SGR의 경우에는 표면의 수축정도가 심했으며, 중량감소율도 HIT보다 큰 것으로 나타나 내구성이 떨어지는 것으로 나타났다. 종합적으로 HIT가 물유리계 재료보다 강도, 내구성면에서 우수한 특성을 나타내는 것으로 나타나 해상구조물 그라우트재로 적합할 것으로 판단된다.

• 대한소아치과학회지
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• 제25권3호
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• pp.525-532
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• 1998

치과의사는 자폐인의 치료시 자폐증의 정도와 의학적 관리가 필수적인 질환, 내과적 병력, 현재 환자가 복용하고 있는 약물등을 고려하여 이에 따라 적절한 행동조절 방법을 선택하여야 한다. 행동조절 방법의 선택시 술자가 선호하는 방법을 우선하기 보다는 환자의 상태와 치과치료시 환자와 보호자가 받는 스트레스를 최우선으로 고려하는 것이 필요하다. 환자의 현증에 대한 적절한 행동조절하의 치과치료도 중요하지만, 그보다 더 중요한 것은 환자가 거부감을 느끼지 않고 치과에 내원할수 있도록 훈련시키는 것과 지속적인 구강위생 관리이므로 보호자를 위한 구강위생 관리교육 및 주기적인 내원에 의한 관리가 필요하다고 생각된다.

• 한국세라믹학회지
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• 제56권5호
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• pp.489-496
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• 2019

Cement-based thermal insulation material was manufactured using OPC, lime, anhydrite, and CSA cement in this study. The morphology and physical properties of the material were analyzed using XRD. All samples had ettringite, Ca(OH)₂, and CaCO₃ crystals. The XRD peak intensity of the ettringite and Ca(OH)₂ slightly increased with an increase in curing time from 3 to 7 days. The compressive strength values at 28 days of specimens 1-8 were in the range of 0.25-0.32 MPa, and the compressive strength values of specimens 3-8 were > 0.3 MPa. The coefficients of correlation between compressive strength and apparent gravity at 7 days and those between compressive strength and ettringite/Ca(OH)₂ XRD peak intensity at 28 days were above 0.8. That is, the compressive strength exhibited an influence on apparent gravity at 7 days and on hydrate at 28 days. The thermal conductivity of all specimens was 0.041-0.045 W/mK, and the highest value of thermal conductivity was shown by specimen 5. The coefficient of correlation between apparent gravity and thermal conductivity was 0.84. It was concluded that control of raw materials and hydrates must be considered for manufacturing of insulation materials. The cement-based thermal insulation material in this study could be used in construction fields.

• 자원리싸이클링
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• 제18권3호
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• pp.42-48
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• 2009

고로 수쇄 슬래그에 알칼리 자극제(NaOH+$Na_2O.SiO_2$)를 첨가한 계는 보통 포틀랜드 시멘트의 수화반응과 다르게, 수화반응 초기에 높은 농도의 $OH^-,\;[SiO_4]^{4-}$ 이온이 존재하게 되므로, 유도기가 없이 수화반응이 빠르게 진행되며, 슬래그 입자 주위에 수화물에 의한 reaction rim을 형성한다 반응기간 1일부터 고로 수쇄 슬래그 입자 주위에 $0.6{\mu}m$의 reaction rim이 형성되었고, 반응기간이 증가함에 따라 reaction rim의 두께는 증가하여 28일에 $1{\mu}m$으로 성장하였으며, 미반응 고로 수쇄 슬래그 입자는 각진 형태에서 구형의 형태로 변화되었다. 슬래그 입자의 내부로부터 reaction rim으로 갈수록 Ca/Si의 몰비는 감소하는 경향을 나타냈었다. 그리고 반응기간이 경과할수록 슬래그 입자 내부와 reaction rim간의 Ca/Si 몰비 차이는 작아졌으며, 생성된 수화물은 저결정성의 Ca/Si 몰비가 1.5 미만인 CSH(I)이었다.

• Corrosion Science and Technology
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• 제6권5호
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• pp.227-232
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• 2007

The corrosion behavior of carbon steel (N80) in carbon dioxide saturated 1%NaCl solution with and without acetic acid or acetate was investigated by weight-loss test, electrochemical methods (polarization curve, Electrochemical impedance spectroscopy). The major objective is to make clear that the effect of acetic acid and acetate on the corrosion of carbon steel in $Co_2$ environments. The results indicate that either acetic acid or acetate accelerates cathodic reducing reaction, facilitates dissolution of corrosion products on carbon steel, and so promotes the corrosion rate of carbon steel in carbon dioxide saturated NaCl solution. All Nyquist Plots are consisting of a capacitive loop in high frequency region, an inductive loop in medial frequency region and a capacitive arc in low frequency region. The high frequency capacitive loop, medial frequency inductive loop and low frequency capacitive arc are corresponding to the electron transfer reaction, the formation/adsorption of intermediates and dissolution of corrosion products respectively. All arc of the measured impedance reduced with the increase of the concentration of Ac-, especially HAc. However, the same phenomenon is not notable after reducing pH value by adding HCl. HAc is a stronger proton donor and can be reduced directly by electrochemical reaction firstly. Ac- can't participate in electrochemistry reaction directly, but $Ac^-$ an hydrate easily to create HAc in carbon dioxide saturated environments. HAc is as catalyst in $Co_2$ corrosion. As a result, the corrosion rate was accelerated in the presence of acetate ion even pH value of solution increased.

• 한국건축시공학회지
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• 제18권3호
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• pp.305-312
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• 2018

This study is about the development of a non-sintered binder (NSB) which does not require a sintering process by using the industrial by-products Phosphogypsum (PG), Waste Lime (WL) and Granulated Blast Furnace Slag (GBFS). In this report, through SEM analysis of the NSB paste hardening body, micropore analysis of paste using the mercury press-in method and microstructure observation were executed to consider the influence of the formation of the pore structure and the distribution of pore volume on strength, and the following conclusions were reached. 1) Pore structure of NSB paste of early age is influenced by hydrate generation amount by GBFS and activator. 2) Through observing the internal microstructure of NSB binder paste, it was found that the strength expression at early age due to hydration reaction was achieved with a large amount of ettringite serving as the frame with C-S-H gel generated at the same time. It was confirmed that C-S-H gel wrapped around ettringite, and as time passed, the amount generated continually increased, and C-S-H gel tightly filled the pores of hardened paste, forming a dense network-type web structure. 3) For NSB-type cement, the degree of formation of gel pores below $10{\mu}m$ had a greater influence on strength improvement than simple pore reduction by charging capillary pores, and the pore size that had the greatest effect on strength was micropores with diameter below $10{\mu}m$.