• 한국안전학회지
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• 제25권1호
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• pp.79-86
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• 2010

Although nano materials are used a lot in industries, there has not been any standard nano hazard graphic symbol. An experiment was conducted to know the comprehension ratio of newly designed eight nano graphic symbols. To compare the symbols with existing safety graphic symbols, other sixteen symbols were also included. 54 subjects evaluated the difficulties of graphic symbols on seven point Likert scale and answered the meaning for each symbol. The all eight nano safety symbols marked under 30% comprehension ratio. However, one of them didn't show any statistically significant difference with other existing safety symbols as like bio hazard, radiation, and laser. Therefore the nano symbol tested in the best could be adopted as the nano safety graphic symbol if it is sufficiently exposed in training period and used with warning label. The workers in industries using nano materials can be alerted and protect themselves where the sign is attached.

• 한국산업보건학회지
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• 제25권1호
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• pp.95-103
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• 2015

Objectives: This study was conducted in order to better understand the conceptual model and Stoffenmanager nano module and apply it to the synthesis and packing processes of nanomaterials. Methods: Site visits were conducted to five nanomaterial production processes. Product and exposure variables were investigated in these workplaces. Hazard banding and exposure classification of the synthesis and packing processes of nanomaterials were conducted using documents and the website of Stoffenmanager Nano. Results: The five sites featured different products, packing tasks, ventilation and local exhaust, and others. The hazards for nano-nickel and copper were classified as E. The hazards for both fumed silica and indium tin oxide were classified as D. The hazard for spherical silica was classified as C. The exposure classes in the synthesis process of nanomaterials ranged from 2 through 4. The exposure classes in the packing process of nanomaterials ranged from 1 through 4. Conclusions: Application of Stoffenmanager nano to the synthesis and packing processes of nanomaterials helped to better understand the control level of the work environment and to suggest appropriate actions. The comparison of each process showed the effect of the production process and handling of solids and ventilation on exposure class.

• 한국가스학회지
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• 제19권5호
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• pp.75-80
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• 2015

나노 및 마이크로 크기의 알루미늄(Al) 분진은 매우 높은 연소열을 가지고 있어서 로켓 추진체와 폭발물 등을 제조하는 원료로 많이 사용되고 있다. 본 연구에서는 서로 다른 크기의 입자경 (70 nm, 100 nm, $6{\mu}m$, $15{\mu}m$)을 가진 알루미늄 분진을 사용하여 열분해 위험성을 실험적으로 검토하였다. 이를 위해 열중량분석장치(TGA)를 사용하여 승온속도의 변화에 따른 열분해특성을 조사하고 입경이 다른 나노 및 마이크로 크기의 Al에서의 중량개시온도(Temperature of weight gain)로부터 발화온도를 추정하였다. 승온속도가 동일한 조건에서 Al분진의 중량개시온도는 입경이 증가할수록 또한 공기중 승온속도가 증가할수록 증가하는 경향을 나타냈다. 이러한 실험결과로부터 Al분진의 열분해 위험성은 분진 입자경의 증가와 함께 감소할 것으로 추정되었다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.38.3-38
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• 2001

In the planetary surface exploration , micro-rovers or nano-rovers are very attractive choices for a surface exploration system providing mobility functions and other features required in the surface probe missions at small mass and relatively small cost. This paper surveys and summarizes the requirements for Mars exploration rovers in micro or nano scale and outlines the control concepts for navigation including the obstacle/hazard avoidance and the path planning. In this context, autonomous reaction capabilities are the key elements to control design in conjunction with the remote control schemes to deal with the significant signal propagation delays. Other navigation and control aspects such as the instrument fine positioning and the flip-over of the rovers are also briefly introduced. The current technical limitations of the micro- and nano-rovers are summarized.

• 한국방재학회 논문집
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• 제7권3호
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• pp.33-39
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• 2007

본 연구는 균열이 발생된 콘크리트 구조물의 성능 회복 및 성능 향상을 위하여 첨단 기술을 접목한 경제적이고 친환경적인 나노 합성 무기계 균열보수재를 균열이 발생된 콘크리트 구조물에 적용하기 위하여 나노 합성 무기계 균열보수재의 역학적 특성 및 내구 특성을 종합적으로 평가하였다. 균열 보수재의 역학적 특성을 평가한 결과 모든 균열보수재가 표준 및 건습반복 상태에서 우수한 부착성능을 나타내었으며, 염분침투확산, 탄산화 및 내염수성 실험결과도 매우 양호한 결과를 나타내었다. 따라서 균열에 의한 성능저하가 발생하여 콘크리트 구조물의 보수 보강이 필요할 경우 본 연구에서 적용한 나노 합성 무기계 균열보수재를 이용하여 콘크리트 구조물의 성능 회복 및 성능 향상을 이룰 수 있을 것으로 판단된다.

• Toxicological Research
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• 제31권2호
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• pp.181-189
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• 2015

In recent years, the use of both nano- and micro-sized lanthanum has been increasing in the production of optical glasses, batteries, alloys, etc. However, a hazard assessment has not been performed to determine the degree of toxicity of lanthanum. Therefore, the purpose of this study was to identify the toxicity of both nano- and micro-sized lanthanum oxide in cultured cells and rats. After identifying the size and the morphology of lanthanum oxides, the toxicity of two different sized lanthanum oxides was compared in cultured RAW264.7 cells and A549 cells. The toxicity of the lanthanum oxides was also analyzed using rats. The half maximal inhibitory concentrations of micro-$La_2O_3$ in the RAW264.7 cells, with and without sonication, were 17.3 and 12.7 times higher than those of nano-$La_2O_3$, respectively. Similar to the RAW264.7 cells, the toxicity of nano-$La_2O_3$ was stronger than that of micro-$La_2O_3$ in the A549 cells. We found that nano-$La_2O_3$ was absorbed in the lungs more and was eliminated more slowly than micro-$La_2O_3$. At a dosage that did not affect the body weight, numbers of leukocytes, and concentrations of lactate dehydrogenase and albumin in the bronchoalveolar lavage (BAL) fluids, the weight of the lungs increased. Inflammatory effects on BAL decreased over time, but lung weight increased and the proteinosis of the lung became severe over time. The effects of particle size on the toxicity of lanthanum oxides in rats were less than in the cultured cells. In conclusion, smaller lanthanum oxides were more toxic in the cultured cells, and sonication decreased their size and increased their toxicity. The smaller-sized lanthanum was absorbed more into the lungs and caused more toxicity in the lungs. The histopathological symptoms caused by lanthanum oxide in the lungs did not go away and continued to worsen until 13 weeks after the initial exposure.

• 한국재료학회지
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• 제14권6호
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• pp.407-412
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• 2004

Photo decomposition of gas phase benzene by $TiO_2$ thin films chemically deposited on alumina balls were investigated under UV irradiation. Photo decomposition rates were measured in real time during the reaction using a photo ionization detector, which ionizes C-H bonding of benzene molecules and then converts into volatile organic compounds (VOCs) concentrations. From the measuring results, the VOCs concentration increased instantly when IN irradiated because C-H bonds of benzene molecules strongly absorbed on the surface of $TiO_2$ films before the IN irradiation was destroyed by photo decomposition. After that, the VOCs concentration decreased with increasing surface area of $TiO_2$ and reaction time under the IN irradiation. At the optimal conditions for the photo decomposition of gas phase benzene, the reaction rate of the photo decomposition for high concentrations (over 60 ppm) was slow but that of relatively low concentration (under 60 ppm) was fast, due to limited surface area of $TiO_2$ thin films for the reaction. Thus, it is concluded that the photo decomposition rate was mainly affected by the surface area of $TiO_2$ or absorption reaction.

• Journal of Biosystems Engineering
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• 제39권2호
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• pp.115-121
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• 2014

Background: Frequent outbreaks of foodborne illness have been increased awareness of food safety. CDC estimates that each year roughly 48 million people gets sick, 128,000 are hospitalized and 3,000 die of foodborne diseases in US. In Korea, 6,058 were hospitalized and 266 incidents were reported in 2012. It is required to develop rapid methods to identify hazard substances in food products for protecting and maintaining safety of the public health. However, conventional methods for pathogens detection and identification involve prolonged multiple enrichment steps. Purpose: This review aims to provide information on biosensors to detect pathogens in food products to enhance food safety. Results: Foodborne outbreaks continue to occur and outbreaks from various food sources have increased the need for simple, rapid, and sensitive methods to detect foodborne pathogens. Conventional methods for foodborne pathogens detection require tremendous amount of labor and time. Biosensors have drawn attentions in recent years because of their ability to detect analytes sensitively and rapidly. Principles along with their advantages and disadvantages of a variety of food safety biosensors including fiber optic biosensor, impedimetric biosensor, surface Plasmon resonance biosensor, and nano biosensor were explained. Also, future trends for the food safety biosensors were discussed.

• Advances in nano research
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• 제10권4호
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• pp.397-414
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• 2021

The steady growth in population has led to an enhanced water demand and immense pressure on water resources. Pharmaceutical residues (PRs) are unused or non-assimilated medicines found in water supplies that originate from the human and animal consumption of antibiotics, antipyretics, analgesics etc. These have been detected recently in sewage effluents, surface water, ground water and even in drinking water. Due to their toxicity and potential hazard to the environment, humans and aquatic life, PRs are now categorized as the emerging contaminants (ECs). India figures in the top five manufacturers of medicines in the world and every third pill consumed in the world is produced in India. Present day conventional wastewater treatment methods are ineffective and don't eliminate them completely. The use of nanotechnology via advanced oxidation processes (AOP) is one of the most effective methods for the removal of these PRs. Present study is aimed at reviewing the presence of various PRs in water supplies and also to describe the process of AOP to overcome their threat. This study is also very important in view of World Health Organization report confirming more than 30 million cases of COVID-19 worldwide. This will lead to an alleviated use of antibiotics, antipyretics etc. and their subsequent occurrence in water bodies. Need of the hour is to devise a proper treatment strategy and a decision thereof by the policymakers to overcome the possible threat to the environment and health of humans and aquatic life.

• 한국환경보건학회지
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• 제39권4호
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• pp.369-375
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• 2013

Objectives: This study was conducted to identify factors determining the toxicity of manufactured silver nano-particles (AgNPs) on aquatic organisms. Methods: For this purpose, we prepared several AgNPs with varied characteristics, including hydrodynamic size (nano-$^{ABC}Ag^{Cit}\;vs$-sized-$^{ABC}Ag^{Cit}$), impurities ($^{ABC}Ag$ stock vs $^{ABC}Ag$), and citrate capping ($^{ABC}Ag^{Cit}$), using a commercially available manufactured AgNP ($^{ABC}Ag$ stock). Acute tests were conducted using larval zebrafish (Danio rerioI). In addition, in order to determine the ecotoxicological potentials of various capping agents, toxicity tests were conducted with microbes, waterfleas, and fish for eight different capping agents that are used for NPs. Results: The toxicity of AgNPs in terms of 96 h fish $LC_{50}$ increased in the following order: $^{ABC}Ag$ stock < $^{ABC}Ag=^{ABC}Ag^{Cit}=nano-^{ABC}Ag^{Cit}$ < ${\mu}$-sized-$^{ABC}Ag^{Cit}$ < $AgNO_3$. After removing impurities by dialysis, 96 h $LC_{50}$ value decreased significantly from $126.6{\mu}g/L$ (95% confidence intervals [CI]: 107.0-146.2) ($^{ABC}Ag$ stock) to $78.6{\mu}g/L$ (CI: 72.7-84.8) ($^{ABC}Ag$). For ${\mu}$-sized-$^{ABC}Ag^{Cit}$ (ranging between 3.9 and 40.6 nm) and $^{ABC}Ag^{Cit}$ (40.6 nm and $9.1{\mu}m$), the 96 h $LC_{50}$ of the former ($43.9{\mu}g/L$, CI: 36.0-51.7) was approximately two-fold lower than that of the latter ($87.0{\mu}g/L$, CI: 73.5-100.3). Conclusions: In this study, we found that for acute lethality, the contribution of impurities and particle size was significant, but that of citrate was negligible.