• 공업화학
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• 제18권4호
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• pp.320-325
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• 2007

본 연구에서는 재래식 및 마이크로파 합성법을 통하여 비수계 유기용매인 diethanolamine을 용매로 하여 초산니켈 수용액과 히드라진 수화물로부터 니켈 분말을 합성하였다. X선 회절분석, 주사 전자현미경 분석, 열분석 및 X선 광전자 분광기 분석등을 통하여 마이크로파의 비열적 효과 및 반응 조건이 니켈분말의 합성에 미치는 영향을 조사하였다. 재래식 합성과 비교해보면, 마이크로파를 이용한 합성에서 마이크로파의 비열적 효과에 기인하여 상대적으로 응집이 적게 일어나고, 입자 크기는 작고, 입도 분포는 균일하였다.

• 상하수도학회지
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• 제19권1호
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• pp.3-7
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• 2005

In the present study a feasibility of a novel filtration process using synthetic for secondary effluent reclamation was investigated. Polyurethane was chosen as a filter medium among tested three media. Compressibility and up-flow velocity were changed to determine the optimum operation for the system. An equation was introduced to express the relationship between the removal efficiency and up-flow velocity. In pilot study, the synthetic medium filtration with compression showed very stable effluent quality without clogging trouble, though the system operated with 3 times higher filtration rate and much longer backwashing interval than conventional systems.

• Journal of Magnetics
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• 제7권4호
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• pp.147-150
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• 2002

The pinning direction, the spin flop behaviors and the magnetoresistive properties in top synthetic spin valve structure [NiFe/CoFe/Cu/CoFe (t$_{p2}$)/Ru/CoFe (t$_{p1}$)/IrMn] were investigated. The magnetoresistive and pinning characteristics of synthetic spin valves strongly depended on the differences in the two pinning layer thickness, ${\Delta}t(=t_{p2}-t_{p1})$. In contrast to the conventional spin valves, the pinning direction (P1) was canted off with respect to the growth field axis with ${\Delta}t$. We found that the canting angle ${\Phi}$ had different values according to the annealing field direction and ${\Delta}t$. When the samples were annealed at above the blocking temperature of IrMn with zero fields, the canted pinned layer could be set along the growth field axis. Because the easy axis which was induced by the growth field during deposition is still active in all ferromagnetic layers except the IrMn at $250{^{\circ}C}$, the pinning direction could be aligned along the growth field axis, even in 0 field annealing.

• 한국산학기술학회논문지
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• 제11권1호
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• pp.29-36
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• 2010

합성과 천연 에메랄드의 열처리에 따른 분광특성 변화를 가시광선과 적외선 분광분석으로 관찰하였다. X-선 형광분석 결과 flux 합성 에메랄드에서는 Mo과 Co이 검출 되었고, hydrothermal 합성 에메랄드에서는 Cl 성분이 나타났다. 자외선-가시광선 분광분석 결과는 콜롬비아산 에메랄드 시료에서 열처리 후에 전체적인 흡수 세기가 증가 한 것을 확인 하였다. 적외선 분광 분석 결과, hydrothermal 합성 에메랄드에서 Cl 성분에 관련된 피크가 $3000-2600cm^{-1}$에서 나타났고, 천연 에메랄드에서는 $CO_2$에 기인하는 $2358cm^{-1}$피크가 열처리후에 감소된 것을 확인하였다. 이는 열처리 후에 기체 성분이 변화된 것과 일치 하였다.

• Biomolecules & Therapeutics
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• 제23권6호
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• pp.597-603
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• 2015

Synthetic cannabinoids JWH-018 and JWH-250 in 'herbal incense' also called 'spice' were first introduced in many countries. Numerous synthetic cannabinoids with similar chemical structures emerged simultaneously and suddenly. Currently there are not sufficient data on their adverse effects including neurotoxicity. There are only anecdotal reports that suggest their toxicity. In the present study, we evaluated the neurotoxicity of two synthetic cannabinoids (JWH-081 and JWH-210) through observation of various behavioral changes and analysis of histopathological changes using experimental mice with various doses (0.1, 1, 5 mg/kg). In functional observation battery (FOB) test, animals treated with 5 mg/kg of JWH-081 or JWH-210 showed traction and tremor. Their locomotor activities and rotarod retention time were significantly (p<0.05) decreased. However, no significant change was observed in learning or memory function. In histopathological analysis, neural cells of the animals treated with the high dose (5 mg/kg) of JWH-081 or JWH-210 showed distorted nuclei and nucleus membranes in the core shell of nucleus accumbens, suggesting neurotoxicity. Our results suggest that JWH-081 and JWH-210 may be neurotoxic substances through changing neuronal cell damages, especially in the core shell part of nucleus accumbens. To confirm our findings, further studies are needed in the future.

• 한국수학교육학회지시리즈E:수학교육논문집
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• 제28권1호
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• pp.97-130
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• 2014

본 연구의 목적은 조립제법 소재의 탐구활동에서 나타난 고등학생들의 사고 과정을 분석하여 유추의 양상을 조사하는 것이다. 인문계 고등학교 1학년 학생 2명을 대상으로 질적 사례연구로 수행되었다. 자료의 분석을 위하여 연구자가 제안한 유사성 분류 틀과 Gentner의 Structure-mapping Model(구조사상 모형, 줄여서 SMM)을 이용하였다. 두 학생 모두 유추를 도구로 사용하여 2차 이상의 조립제법을 발견하였으나, 유추적 사고의 능력에 따라 수학적 발견에 차이를 보였다. 탐구활동 과정에서 표면 유사성은 유추에서 중요한 역할을 수행하였다. 구조 유사성에 근거한 유추는 학생들도 수학자처럼 탐구하고 발견할 수 있도록 하였으며, 체계성의 원리에 의한 유추는 다른 영역에 대한 예측과 설명을 가능하게 하였고, 절차 유사성에 의한 유추는 내면화를 이끌어 냈다. 또한 유추의 성격이 도구적, 발견적이고 또한 반성적이라는 결론을 얻었다.

• 한국수소및신에너지학회논문집
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• 제28권5호
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• pp.561-569
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• 2017

In this study, a synthetic amine made using the ethylene oxide-ammonia reaction was used as an absorbent to remove carbon dioxide. Existing absorbents were used in a mix in order to improve performance; however, because the ethylene oxide-ammonia reaction generates primary, secondary, and tertiary amines simultaneously, it has the merit that separate mixing of the absorbents was not needed. The performance of carbon dioxide absorption with the synthetic amine was compared to that of MEA. As a result of an experiment, it was determined that the $CO_2$ loading was 1.15 times better than that of MEA (a commonly used amine), while the cyclic capacity was 2.28 times higher. Because the heat of reaction was 1.10 times lower than for MEA, the synthetic amine showed superior performance in terms of absorption and regeneration.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2003년도 somma/kms meeting
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• pp.80-80
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• 2003

• KIEE International Transactions on Electrophysics and Applications
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• 제5C권4호
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• pp.145-151
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• 2005

The synthetic breaking test method was developed to evaluate the breaking performance of ultra high-voltage circuit breaker and made up of two independent circuits; current source circuit and voltage source circuit. In application of this test method, it is necessary to extend the arc of the test breaker. So, the new re-ignition system using VTGS (Vacuum Triggered Gap-Switch) was constructed to improve the efficiency and reliability of this test. In this re-ignition system, VTGS operates in high vacuum state of $5{\time}10^{17}$torr and control system consists of the triggering device and the air M-G (Motor-Generator). This re-ignition system showed the operating characteristics, such as delay time ($t_d$) and jitter time ($t_j$ not exceeding 5us and 1us respectively, and had the operating voltage of $25\~150kVdc$ at the gap distance of 24mm.

• 대한본초학회지
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• 제33권6호
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• pp.9-18
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• 2018

Objective : Many patients take antihypertensive drugs as well as herbal medicines at the same time in order to treat other symptoms or to keep their well-being. In this study, interactions between herbal medicines and synthetic antihypertensive drugs were analyzed. Methods : To investigate the interaction between herbal medicines and synthetic antihypertensive drugs, three electronic databases, including OASIS, Mediline and Sciencedirect were searched. Experimental and clinical studies on the interaction between herbal medicines and antihypertensive drugs were independently reviewed and included. Results : Analyzing selected studies, twenty herbs were found to interact with antihypertensive drugs. Herbs found to increase the antihypertensive effect were Panax ginseng, Carthamus tinctorius, Magnolia officinalis, Silybum marianum, Scutellaria baicalensis, Schisandra chinensis, Sophora flavescens, Piper nigrum, Curcuma longa, Ginkgo biloba, Juncus effuses and Hydrastis canadensis. In contrast, Commiphora myrrha, Rhodiola rosea, Hypericum perforatum, Eurycoma longifolia, and Daturae metel were found to inhibit the antihypertensive effect. Stephania tetrandra could increase or decrease the effect depending on the type of antihypertensive drug. Epedria sínica was suspected of pharmacodynamic interaction with antihypertensive drug. Glycyrrhiza uralensis has been reported to have serious side effects in combination with antihypertensive drugs. Conclusion : These results imply that when used in combination with herbal medicines and synthetic antihypertensive drugs, proper doses and herbs which are to avoid need to be informed to the patients. Despite concerns about interactions between herbal medicines and synthetic drugs, related research is very limited. More systematic researches are needed to give information on patient safety as well as to guide clinical practice.