• 한국화재소방학회:학술대회논문집
• /
• 한국화재소방학회 1996년도 학술발표회
• /
• pp.57-61
• /
• 1996

Our goal was to make a cost-effective automatic fire extinguishing system for the engine compartment use of automobiles. We designed this system for the engine compartment. This system consists of 1)foam extinguisher, 2)four nozzles, 3)a pipe arrangement, and 4)an extinguishing device which is equipped with a glass bulb as detector. First and foremost, the extinguishing device was carefully designed to keep the system cost to a minimum. Second, a AFFF foam extinguisher was used because no other fire-fighting agents proved effective against fire in the engine compartment. The AFFF(Aqueous Film Forming Foam) agent which was used in the extinguisher is the 3M company's Light Water. We sought, however, to make other foams by using Halon 1301 and Halon alternatives such as HCFC Blend A, HFC-227ea. We selected these alternatives instead of air in order to raise the expansion ratio of the AFFF agent. By these means we discovered that it is possible to increase the expansion ration of the AFFF agent up to 44:1. We then demonstrated that our automatic fire extinguishing system is the most effective and lowest cost-system yet devised for passenger cars.

• 대한한방부인과학회지
• /
• 제33권3호
• /
• pp.95-118
• /
• 2020

목 적: 이 생체 내 연구의 목적은 인도메타신과 비교했을 때 쥐의 원발성 월경통에 대한 계지 복령환 열수 추출물의 진통 및 개선 효과를 관찰하는 것이다. 방 법: 랫트 PD 모델을 만들기 위해, Estradiol benzoate를 10일간 투여한 다음 마지막 10회 estradiol benzoate 투여 1시간 후 1 U/kg의 oxytocin을 투여하였다. 계지복령환 열수 추출물을 500, 250 및 125 mg/kg 용량으로 매일 1회씩 10일간 투여하였다. 이후 체중 및 실험 기간 동안의 체중 증가량, 자궁 중량 및 육안부검 소견, 진통 활성을 나타내는 abdominal writhing test, 자궁 조직 내 지질 과산화(Malondialdehyde, MDA 함량) 및 항산화 방어 시스템 - glutathione (GSH) 함량, superoxide dismutase (SOD) 및 catalase (CAT) 활성, Nuclear factor-κB (NF-κB) 및 cyclooxygenase (COX)-2 mRNA의 발현, 자궁의 조직병리학적 변화, tumor necrosis factor (TNF)-α 및 inducible nitric oxide synthase (iNOS)로 나타나는 면역조직 화학적 변화를 관찰하였다. 계지복령환 열수 추출물의 결과는 인도메타신 투여 쥐의 결과와 비교하였다. 결 과: Estradiol benzoate 및 oxytocin 투여 결과, 현저한 체중 및 증체량, 자궁 GSH 함량, SOD와 CAT 활성의 감소와 abdominal writhing 반응, 자궁 지질 과산화(MDA 함량), 자궁 중량, NF-κB 및 COX-2 mRNA 발현의 증가가 TNF-α 및 iNOS 면역반응세포와 염증세포 침윤 증가, 자궁의 충혈 및 확대와 함께 관찰되었다. 이는 전형적인 염증 및 산화 스트레스성 원발성 월경통이 잘 유도되었음을 의미한다. 한편 이러한 소견은 계지복령환 열수 추출물의 투여에 의해 용량의존적으로 현저히 억제되었으며, 인도메타신의 억제 효과보다는 낮았다. 결 론: 이 연구에서 얻은 결과는 계지복령환 열수 추출물이 estradiol benzoate 및 oxytocin으로 유도된 원발성 월경통에 용량-의존적으로 유리한 진통 및 개선 활성을 가짐을 시사한다.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2010년도 추계학술대회 초록집
• /
• pp.115.2-115.2
• /
• 2010

Autothermal reforming(ATR) processes of hydrocarbon liquids such as diesel fuels are spotlighted as methods to produce hydrogen for Fuel cell. However, the use of heavy hydrocarbons as feedstocks for hydrogen production causes some problems which increase the catalyst deactivation by the carbon deposition. Coking can be inhibited by increasing the water dissociation on the catalyst surface. This results in catastrophic failure of whole system. Performance degradation of diesel autothermal reforming leads to increase of undesirable hydrocarbons at reformed gases and subsequently decrease the performance. In this study, perovskite-based catalysts were investigated as alternatives to substitute the noble metal catalyst for the ATR of diesel. The investigated perovskite structure was based on LaCrO3. and metals were added at the A-site to enhance oxygen ion mobility, transition metals were doped on the B-site to enhance the reformation. Substituted Lanthanum chromium perovskite were made by aqueous combustion synthesis, which can produce high surface area. And for the homogeneous fuel supply, we made ultrasonic injection system for reforming. We compared durability of evaporation system and ultrasonic system for fuel injection.

• Macromolecular Research
• /
• 제15권6호
• /
• pp.547-552
• /
• 2007

Water soluble polymer, poly(vinyl pyrrolidone) was chosen to conjugate with 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine-N-(succinyl) (N-succinyl DPPE) to make a new drug delivery system. PVP with an amine group (amino-PVP) was polymerized by free radical polymerization. The amine group of amino-PVP was conjugated with the carboxylic group of N-succinyl DPPE. The resultant conjugate could form nanoparticles in the aqueous solution; these nanoparticles were termed a lipid-polymer system. The critical aggregation concentration was measured with pyrene to give a value of $1{\times}10^{-3}g/L$. The particle size of the lipid-polymer system, as measured by DLS, AFM and TEM, was about 70 nm. Lipophilic component in the inner part of the lipid-polymer system could derive the physical interaction with hydrophobic drugs. Griseofulvin was used as a model drug in this study. The loading efficiency and release profile of the drug were measured by HPLC. The loading efficiency was about 54%. The release behavior was sustained for a prolonged time of 12 days. The proposed lipid-polymer system with biodegradable and biocompatible properties has promising potential as a passive-targeting drug delivery carrier because of its small particle size.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
• /
• pp.69-69
• /
• 2013

In the area of artificial photosynthesis, particularly for the generation of hydrogen form water, much attention has been paid on organic-inorganic hybrid system. Most of all, a dye/TiO2-combined system has been suggested and its potential utility was well manifested. However, due to its complicated nature of charge interactions in between dye and TiO2 -interface there remains a great challenge to establish the charge-activity relationship, per se light driven charge generation and recombination kinetics with respect to the amount of hydrogen produced. Further complexity of that hybrid system has been witnessed when sacrificial donor and aqueous media are considered. To unveil the operating mechanism on such a dye/TiO2-combined system, we have prepared organic dyes suitable to account for the effect of sacrificial donor as well as water interactions, and prepared the typical dye-grafted TiO2 films to investigate charge-activity relationship. Femtosecond flash photolysis clearly defined the dye effects anchored on to the TiO2 platform. In addition, photodynamic data contemplated well to the dye orientation proposed by the DFT calculations. Recent findings provide fundamental understanding on the dye-grafted TiO2 system and establish a firm background how future dye-sensitized organic-inorganic hybrid system can be designed for the light driven hydrogen generation from water.

• 한국초전도ㆍ저온공학회논문지
• /
• 제22권4호
• /
• pp.45-50
• /
• 2020

In this research, the variation of round-trip efficiency in a liquid air energy storage system (LAES) is calculated and an optimal configuration is found. The multiple stages of cold energy storage are simulated with several materials that process latent heat at different temperature ranges. The effectiveness in the charging and discharging processes of LAES is newly defined, and its relationship with the round-trip efficiency is examined. According to defined correlation, the effectiveness of the discharging process significantly affects the overall system performance. The round-trip efficiency is calculated for the combined cold energy storage materials of aqueous dimethyl sulfoxide (DMSO) solution, ethanol, and pentane theoretically. The performance of LAES varies depending on the freezing point of the cold storage materials. In particular, when the LAES uses several cold storage materials, those materials whose freezing points are close to room temperature and liquid air temperature should be included in the cold storage materials. In this paper, it is assumed that only latent heat is used for cold energy storage, but for more realistic analyzes, the additional consideration of the transient thermal situation to utilize sensible heat is required. In the case of such a dynamic system, since there is certainly more increased heat capacity of the entire storage system, the volume of the cold energy storage system will be greatly reduced.

• Corrosion Science and Technology
• /
• 제7권2호
• /
• pp.85-91
• /
• 2008

By operation in aqueous environment at high temperature and pressure, the structural materials from Primary Heat Transport System (PHTS) cover with protective oxide films, which maintain the corrosion rate in admissible limits. A lot of potential factors exist, which conduct to degradation of the protective films and consequently to intensification of the corrosion processes. The existing experience of different nuclear reactors shows that the water chemistry has an important role in integrity maintaining of the protective oxide films. To investigate the influence of water chemistry (pH, O2 dissolved, $Cl^-$, $F^-$) on corrosion of some structural materials (carbon and martensitic steel, Zr and Ni alloys) and to establish the maximum permissible values, corrosion experiments by static autoclaving and electrochemical methods were performed. The experimental results allowed us to establish the contribution of the water chemistry in initiation and evolution of some accelerated corrosion processes.

• 한국자기공명학회논문지
• /
• 제22권2호
• /
• pp.34-39
• /
• 2018

The Nuclear Magnetic Resonance (NMR) technique using Dynamic Nuclear Polarization (DNP) procedures is one of the promising techniques that enable overcoming low sensitivity problems in NMR spectroscopy. We constructed an ODNP-NMR system using a commercial benchtop EPR spectrometer. The $^1H$ NMR peak area of water in aqueous solutions of 4-hydroxy-TEMPO was enhanced more than 95 times in the ODNP-NMR experiments. Our signal enhancement results were about 55% of the previously reported result. This could be due to non-uniform microwave power over a sample and unwanted sample heating by microwave. However, this portable ODNP-NMR spectrometer will be eventually useful for site-specific detection with nano-scale spatial resolutions and molecular dynamics studies with significantly improved signal sensitivity.

• Applied Microscopy
• /
• 제47권3호
• /
• pp.165-170
• /
• 2017

Gas vesicles are intracellular gas-filled protein-shelled nanocompartments. The structures are spindle or cylinder-shaped, and typically $0.1{\sim}2{\mu}m$ in length and 45~250 nm in width. A variety of prokaryotes including photosynthetic bacteria and halophilic archaea form gas vesicles in their cytoplasm. Gas vesicles provide cell buoyancy as flotation devices in aqueous habitats. They are used as nanoscale molecular reporters for ultrasound imaging for biomedical purposes. The structures in halophilic archaea are poorly resolved due to the low signal-to-noise ratio from the high salt concentration in the medium. Such a limitation can be overcome using focused ion beam-thinning or inelastically scattered electrons. As the concentric bodies (~200 nm in diameter) in fungi possess gas-filled cores, it is possible that the concept of gas vesicles could be applied to eukaryotic microbes beyond prokaryotes.

• KSBB Journal
• /
• 제6권3호
• /
• pp.281-288
• /
• 1991

This research was carried to investigate the effects of several organic solvents on the enzymatic transphosphatidylation in emulsion and two-phase solvent systems. The solvents having a similar dielectric constant with diethylether were effective for the enzyme activity. Diethylether and butylacetate were the most effective solvents, when added 12-15%(v/v) and 10-40%(v/v), respectively, for the synthesis of phosphatidylglycerol, phosphatidylethyleneglycol and phosphatidylpropyleneglycol. In the emulsion system, the size of ovolecithin liposome was increased and the clearness of the phospholipid bilayer was reduced as increasing the diethylether concentration. In the twophase solvent system, the rapidest reaction was obtained when water-organic solvent ratio was close to 1. The ratio of aqueous phase. however, should be lowered to 37% to gain the sole product of transphosphatidy1ation, without phosphatidohydrolysis.