• 대한약침학회지
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• 제8권1호
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• pp.21-30
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• 2005

Objectives : To observe physiological anti-body effects of anti-BV, acute toxic response, measurement of $LD_{50}$, and the effects of anti-body were evaluated. Methods : $LD_{50}$ of Anti-Bee Venom were measured, and to analyze acute toxic responses, weight, and the anti-body effects various concentrations of Anti-BV were diluted and the survival rate was measured. Cell blood count (CBC), liver, spleen, and kidney pathologies were observed from the histological aspects. Results : Experiment was conducted to observe Anti-BV as the anti-body to the bee venom and the following results were obtained : 1.anti-BV was injected intraperitoneally and no toxic responses were witnessed. All of the experiment subjects stayed alive during the experiment, making $LD_{50}$ analysis impossible. 2.Anti-BV was injected intraperitoneally in mice and no significant weight changes were measured between the control group and the experiment groups. 3. Measuring the concentration dependent survival rate, the highest survival rate was at the concentration of $1.25{\times}10^2mg/kg$(1/2.000) for Anti-BV. 4. No particular results were shown in the CBC test. 5. Observation of changes in the organ tissues, Anti-BV was found to suppress blood stasis in the liver and inhibit necrosis of the cells. Conclusion : Above results suggest that Anti-BV doesn't cause any toxic responses in the body and works as an anti-body to the bee venom. Further studies must be followed to secure the findings.

• 대한치과보철학회지
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• 제36권5호
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• pp.701-720
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• 1998

Research advances in dental implantology have led to the development of several different types of materials and it is anticipated that continued research will lead to advanced dental implant materials. Currently used pure titanium has relatively low hardness and strength which may limit its ability to resist functional loads as a dental implant. Ti-6Al-4V also has potential problems such as corrosion resistance. osseointegration properties and neurologic disorder due to aluminium and vanadium, known as highly toxic elements, contained in Ti-6Al-4V. Newly developed titanium based alloys(Ti-20Zr-3Nb-3Ta-0.2Pd-1In, Ti-20Zr-3Nb-3Ta-0.2Pd) which do not contain toxic metallic components were designed by the Korea Institute of Science and Technology (KIST) with alloy design techniques using Zr, Nb, Ta, Pd, and In which are known as non-toxic elements. Biocompatibility and osseointegration properties of these newly designed alloys were evaluated after implantation in rabbit femur for 3 months. The conclusions were as follows : 1. Mechanical properties of the new designed Ti based alloys(Ti-20Zr-3Nb-3Ta-0.2Pd-1In, Ti-20Zr-3Nb-3Ta-0.2Pd) demonstrated close hardness and tensile strength values to Ti-6Al-4V. 2. New desinged experimental alloys showed stable corrosion resistance similar to the pure Ti but better than Ti-6Al-4V. However, the corrosion rate was higher for the new alloys. 3. Cell culture test showed that the new alloys have similar cell response compared with pure Ti and Ti-6Al-4V with no cell adverse reaction. 4. New designed alloys showed similar bone-metal contact ratio and osseointegration properties compared to pure Ti and Ti-6Al-4V after 3 months implantation in rabbit femur. 5. Four different surface treatments of the metals did not show any statistical difference of the cell growth and bone-metal contact ratio.

• 항공우주시스템공학회지
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• 제14권3호
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• pp.24-31
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• 2020

기존 독성 접촉점화성 추진제를 대체할 수 있는 과산화수소 기반 저독성 접촉점화성 추진제에 대한 연구를 수행하였다. Amine 계열 용매와 반응성 첨가제를 이용한 연료 후보군을 선정하고 이들에 대해 CEA code를 이용한 성능해석을 통한 이론적 비추력을 산출하였으며, Drop test를 통해 점화지연을 측정하였다. 해석 결과 산화제 농도 95 wt% 기준 NTO/UDMH 대비 96% 수준의 비추력이 확인되었으며 3종의 연료 후보 모두 10ms 이내의 짧은 점화지연이 확인되었다. 이를 통해 고응답 저독성 접촉점화성 추진제의 개발 가능성이 확인되었으며 향후 비추력과 점화지연 관점의 첨가제 농도 최적화에 대한 연구 필요성을 확인하였다.

• The Korean Journal of Pain
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• 제27권3호
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• pp.229-238
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• 2014

Background: A toxic dose of bupivacaine produces vasodilation in isolated aortas. The goal of this in vitro study was to investigate the cellular mechanism associated with bupivacaine-induced vasodilation in isolated endothelium-denuded rat aortas precontracted with phenylephrine. Methods: Isolated endothelium-denuded rat aortas were suspended for isometric tension recordings. The effects of nifedipine, verapamil, iberiotoxin, 4-aminopyridine, barium chloride, and glibenclamide on bupivacaine concentration-response curves were assessed in endothelium-denuded aortas precontracted with phenylephrine. The effect of phenylephrine and KCl used for precontraction on bupivacaine-induced concentration-response curves was assessed. The effects of verapamil on phenylephrine concentration-response curves were assessed. The effects of bupivacaine on the intracellular calcium concentration ($[Ca^{2+}]_i$) and tension in aortas precontracted with phenylephrine were measured simultaneously with the acetoxymethyl ester of a fura-2-loaded aortic strip. Results: Pretreatment with potassium channel inhibitors had no effect on bupivacaine-induced relaxation in the endothelium-denuded aortas precontracted with phenylephrine, whereas verapamil or nifedipine attenuated bupivacaine-induced relaxation. The magnitude of the bupivacaine-induced relaxation was enhanced in the 100mM KCl-induced precontracted aortas compared with the phenylephrine-induced precontracted aortas. Verapamil attenuated the phenylephrine-induced contraction. The magnitude of the bupivacaine-induced relaxation was higher than that of the bupivacaine-induced $[Ca^{2+}]_i$ decrease in the aortas precontracted with phenylephrine. Conclusions: Taken together, these results suggest that toxic-dose bupivacaine-induced vasodilation appears to be mediated by decreased calcium sensitization in endothelium-denuded aortas precontracted with phenylephrine. In addition, potassium channel inhibitors had no effect on bupivacaine-induced relaxation. Toxic-dose bupivacaine-induced vasodilation may be partially associated with the inhibitory effect of voltage-operated calcium channels.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2012년도 춘계학술발표대회
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• pp.65-65
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• 2012

Copper zinc tin sulfide ($Cu_2ZnSnS_4$, CZTS) is a very promising material as a low cost absorber alternative to other chalcopyrite-type semiconductors based on Ga or In because of the abundant and economical elements. In addition, CZTS has a band-gap energy of 1.4~1.5eV and large absorption coefficient over ${\sim}10^4cm^{-1}$, which is similar to those of $Cu(In,Ga)Se_2$(CIGS) regarded as one of the most successful absorber materials for high efficient solar cell. Most previous works on the fabrication of CZTS thin films were based on the vacuum deposition such as thermal evaporation and RF magnetron sputtering. Although the vacuum deposition has been widely adopted, it is quite expensive and complicated. In this regard, the solution processes such as sol-gel method, nanocrystal dispersion and hybrid slurry method have been developed for easy and cost-effective fabrication of CZTS film. Among these methods, the hybrid slurry method is favorable to make high crystalline and dense absorber layer. However, this method has the demerit using the toxic and explosive hydrazine solvent, which has severe limitation for common use. With these considerations, it is highly desirable to develop a robust, easily scalable and relatively safe solution-based process for the fabrication of a high quality CZTS absorber layer. Here, we demonstrate the fabrication of a high quality CZTS absorber layer with a thickness of 1.5~2.0 ${\mu}m$ and micrometer-scaled grains using two different non-vacuum approaches. The first solution-processing approach includes air-stable non-toxic solvent-based inks in which the commercially available precursor nanoparticles are dispersed in ethanol. Our readily achievable air-stable precursor ink, without the involvement of complex particle synthesis, high toxic solvents, or organic additives, facilitates a convenient method to fabricate a high quality CZTS absorber layer with uniform surface composition and across the film depth when annealed at $530^{\circ}C$. The conversion efficiency and fill factor for the non-toxic ink based solar cells are 5.14% and 52.8%, respectively. The other method is based on the nanocrystal dispersions that are a key ingredient in the deposition of thermally annealed absorber layers. We report a facile synthetic method to produce phase-pure CZTS nanocrystals capped with less toxic and more easily removable ligands. The resulting CZTS nanoparticle dispersion enables us to fabricate uniform, crack-free absorber layer onto Mo-coated soda-lime glass at $500^{\circ}C$, which exhibits a robust and reproducible photovoltaic response. Our simple and less-toxic approach for the fabrication of CZTS layer, reported here, will be the first step in realizing the low-cost solution-processed CZTS solar cell with high efficiency.

• 한국가스학회지
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• 제18권4호
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• pp.76-85
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• 2014

본 연구는 독성가스 사고의 주요 원인의 하나인 부식에 대해 고압 독성가스시설을 대상으로 필요한 안전기술을 정립하기 위하여 미국석유학회에서 개발한 API-581 절차를 채택하여 사고결과 분석방법에 대한 적용성을 검토하고, 이를 바탕으로 사고결과 분석방법을 제시하였다. 고압 독성가스시설에서 API-581의 8단계 사고결과 분석절차에 따라 단계별 적용성을 검토한 결과, 고압 독성가스시설에 적용할 사고결과 분석방법은 총 6단계로 단순화 할 수 있었다. 즉, Step 1(대표물질 결정), Step 5(누출유형 결정), Step 6(유체상 결정)과 Step 8(사고 피해영역 산출)은 적용하지 않고, Step 3(누출량 산출)은 inventory group 개념만 적용하며, Step 4(누출속도 산출)는 기체 누출속도만을 적용하고, Step 2(누출공 크기 선정)와 Step 7(완화시스템 등급 결정)은 전부 적용한다. 이때, Step 5와 Step 8은 일반적으로 적용이 가능한 CCPS 방법을 대안적인 방법으로 채택한다.

• Safety and Health at Work
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• 제9권3호
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• pp.352-355
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• 2018

Hazardous work zones (i.e., hot, warm, and cold) are typically established by emergency response teams during hazardous materials (HAZMAT) calls but less consistently for fire responses to segment personnel and response activities in the immediate geographic area around the fire. Despite national guidelines, studies have documented the inconsistent use of respiratory protective equipment by firefighters at the fire scene. In this case-series report, we describe warm zone gas levels using multigas detectors across five independent fire incident responses all occurring in a large South Florida fire department. Multigas detector data collected at each fire response indicate the presence of sustained levels of volatile organic compounds in the "warm zone" of each fire event. These cases suggest that firefighters should not only implement strategies for multigas detector use within the warm zone but also include respiratory protection to provide adequate safety from toxic exposures in the warm zone.

• Animal cells and systems
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• 제6권3호
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• pp.187-193
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• 2002

It has long been recognized that exposure to low levels of toxic chemicals could have beneficial effects, such as increased resistance to related chemicals or stimulation of growth or development. The notion of radiation hormesis, that exposure to low levels of ionizing radiation could produce beneficial effects, developed seriously in the late 1950’s, and was, to most radiation scientists, incredible. This was due in pan to the then prevailing ideas of radiobiological mechanisms, in part to the sweeping generalizations made by the leading proponents of the radiation hormesis concept, and in pan to the many failures to confirm reports of beneficial effects. More recent understanding of the mechanisms of radiation damage and repair, and discoveries of induction of gene expression by radiation and other genotoxic agents [the adaptive response] make it seem inevitable that under suitable conditions, irradiation will produce beneficial effects.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.405-405
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• 2000

We designed the artificial olfactory sensing system (Electronic Nose) using MOS type sensor array fur recognizing and analyzing odour. The response of individual sensors of sensor array, each processing a slightly different response towards the sample volatiles, can provide enough information to discriminate between sample odours. In this paper, we applied clustering algorithm for dimension reduction, such as linear projection mapping (PCA method), nonlinear mapping (Sammon mapping method) and the combination of PCA and Sammon mapping having a better discriminating ability. The odours used are VOC (Volatile chemical compound) and Toxic gases.

• 한국대기환경학회:학술대회논문집
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• 한국대기환경학회 2002년도 추계학술대회 논문집
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• pp.103-104
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• 2002

산업의 발달에 따라 국내에 유통되는 화학물질의 종류 및 취급량이 최근 급증하고 있으며 이에 비례해서 유해화학물질과 연관된 사고 사례도 매년 증가하고 있다(산업자원부, 2001). 이러한 화학사고의 체계적인 대응을 위해 국립환경연구원의 화학물질안전관리센터에서는 2002년 초부터 주요 화학 공단을 중심으로 국가차원의 실시간 화학물질 사고대응 정보시스템 (CARIS : Chemical Accident Response Information System)을 구축하여 유해화학물질을 체계적으로 관리·운영하고 있다 (국립환경 연구원, 2002). (중략)