• Journal of Korean Neurosurgical Society
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• v.30 no.sup1
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• pp.37-43
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• 2001

Object : The rapid and early oxygen delivery to brain tissue was a common therapeutic method in the treatment of severe head injury patients. The purpose of this study was to investigate the effect of increased fraction of inspired oxygen in early stage of severe head injury. Methods : The parameters of research were CSF(cerebral spinal fluid) oxygen pressure($PcsfO_2$), lactate, pH, temperature, and CSF carbon dioxide pressure($PcsfCO_2$). We selected 28 patients with head trauma whose the Glasgow Coma Scale(GCS) score was less than 8 point at admission. All patients were mechanically ventilated and monitored with the commercial ICP monitoring device. Each of parameters was compared as increased fraction of inspired oxygen. In experimental cohort of 14 patients, the mean $PcsfO_2$ level was increased to $314.93{\pm}259.15mmHg$ by raising the $FiO_2$ from 40% to 100% for nine hours(p<0.05). And the mean CSF lactate level was decreased to $2.96{\pm}1.98mmol/L$ on 100% $FiO_2$ as compared with $5.98{\pm}3.25mmol/L$ on 40% $FiO_2$ in control group(p<0.05). The only above two parameters were showed statistically meaningful outcome. Conclusions : Although this study was performed in small cohort and short period, these results supports that increased inspired oxygen therapy in severe head injuried patients was recommended as a modality of treatment in future through the continuous survey.

• Environmental and Resource Economics Review
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• v.30 no.3
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• pp.471-501
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• 2021

We measure Environmental Efficiency (EE) based on CO₂ in four income groups from 1998 to 2018, using the Meta Stochastic Frontier Analysis method by Input Distance Function. Our results showed that economic growth and energy consumption would increase carbon dioxide emissions, and increasing labor and capital input will reduce it. Moreover, we compared Group Environmental Efficiency (GEE), Meta Environmental Efficiency (MEE), and Environmental Gap Ratio (EGR). The results showed that GEEs were be overestimated. Furthermore, the MEE showed a downward trend during this period. The lower-middle-income group had the highest EGR performance. High-income and upper-middle-income groups showed less efficiency in MEE and EGR. To improve environmental efficiency, we must reduce fossil fuels and find more scientific and technological ways to solve existing environmental problems as soon as possible.

• Journal of Climate Change Research
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• v.7 no.3
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• pp.249-256
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• 2016

Porous $Al_2O_3$ hollow fiber membranes were successfully prepared by dry-wet spinning/sintering method. The SEM image shows that the $Al_2O_3$ hollow fiber membrane consists mostly of sponge pore structure. The contact angle and the breakthrough pressure were $126^{\circ}$ and 1.91 bar, respectively. This results indicate that the $Al_2O_3$ hollow fiber membranes were successfully modified to hydrophobic surface. The hydrophobic modified $Al_2O_3$ hollow fiber membranes were assembled into a membrane contactor system to separate $CO_2$ from a model gas mixture of the flue gas at elevated gas velocity. The $CO_2$ absorption flux was enhanced when the gas velocity increased from $1{\times}10^{-3}$ to $6{\times}10^{-3}$ m/s. Whereas the $CO_2$ absorption flux was decreased with the number of hollow fiber membrane of a module because of the concentration polarization. Furthermore, we developed an lab-scale $Al_2O_3$ hollow fiber membrane contactor modules and their system (i.e., $CO_2$ absorption using the $Al_2O_3$ membrane and monoethanolamine (MEA)) that could dispose of over $0.02Nm^3/h$ mixture gas (15% $CO_2$) with the removal efficiency higher than 95%. The results can be useful in a field of the membrane contactor for $CO_2$ separation, helping to design and extend a equipment.

• Journal of the Korea Organic Resources Recycling Association
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• v.26 no.4
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• pp.5-10
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• 2018

In this study, the effect of physico-chemical factors (e.g., pressure, electrolyte, and organic matter) in the gas hydrate deposit on CH4-CO2 replacement process was investigated experimentally. The higher initial pressure during gas injection led the higher reaction rate at the first time, but finally it did not. Electrolytes and organic matter have some effects on reforming process after dissociation of gas hydrate. It is expected that further research using real marine sediments with actual gas hydrate will enable the development of technologies applicable to the characteristics of domestic seabed geology. Ultimately, it is expected that it will be possible to recover and utilize methane as an organic resource through application of domestic gas hydrate deposit in the Ulleung Basin, East Sea.

• Korean Journal of Heritage: History & Science
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• v.48 no.3
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• pp.138-153
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• 2015

For preventing the biological damage domestically, insect damage control method using chemical medicine has been applied. However, it is trend to avoid existing chemical medicine such as Methyl bromide because of the problem of being harmful to human body and environment. Therefore, the research for new medicine to replace this has been done and the interest to the physical treatment such as temperature(high & low) treatment, hypoxic treatment, carbon dioxide treatment, and radiation treatment has increased. However the systematic application standard and way has not been established. Therefore, in this research, we are going to organize present condition of domestic cultural asset preventing biological damage after the 1980's. It will also consider the direction through the characteristic of technology, limit, and replacement medicine by examining the past research.

• Journal of the Korea Institute of Building Construction
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• v.19 no.4
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• pp.323-330
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• 2019

The cement industry is considered a major industry for reducing greenhouse gases, increasing the amount of binding materials that can replace cement in concrete is known as the most effective method for reducing carbon dioxide. Therefore, research is being carried out to utilize large quantities of by-products that can be used as alternatives to cement. However, there are problems with reduced strength at early age and retarded setting for major reasons that do not increase the amount of mixture of binders used to replace cement. Thus, in this study, normal cement and high-fineness cement were used and physical properties were reviewed by placing differences in fly ash usage depending on the type of cement. As a result, the characteristics of strength were similar, and the hydration temperature was the same level. Also, the durability test showed that the length change, carbonation resistance were better than those of normal cement. Therefore, it is confirmed that the use of high-fineness cement is effective to reduce the amount of cement used and using more by-products.

• Textile Coloration and Finishing
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• v.31 no.1
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• pp.48-64
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• 2019

With evolution in the production environment of the textile industry, the need for non-water-based dyeing technologies and eco-friendly process facilities in the dyeing and processing stages has increased. In recent years, supercritical fluid dyes have been developed and commercialized in Europe, centering on this demand. However, so far, such dyes have been mainly applied in the processing of PET fibers. Basic research has mainly involved investigation of dyeing by supercritical carbon dioxide or solubility of such dyes, and more in-depth research should be continuously carried out. In this review, we describe the types and characteristics of supercritical fluids that exhibit specific properties at pressures and temperatures over the critical point. In addition, the state of the art in the dyeing and processing technology using supercritical fluids and associated, processing problems, environmental regulation, and wastewater treatment issues are described in detail. We hope this review can contribute to the supercritical fluid technology being further developed as an environment friendly dyeing processing method. Furthermore, we expect that the technique can be used as a means of ensuring different, high-quality dyed products.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.12
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• pp.600-606
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• 2018

A class D fire or combustible metal fire is characterized by the presence of burning metals. Only certain metals or metal compounds are flammable, including sodium and lithium. General fire extinguishing agents, such as dry chemical powder, water-based fire extinguish agents, and carbon dioxide, cannot be used in class D fires. This is because these agents cause adverse reactions or are ineffective. In addition, the amount of usage of combustible metals is increasing due to continuous development of the semiconductor and fuel cell industries. Despite this, Korea does not have standards and laws related to combustible metal fires. This paper suggests directions of the class D fire management policies to reduce the class D fire risk and impact by analyzing the standards and laws related to class D fires and combustible metal fire cases. The factors to make laws on class D fire prevention and response systems, and management system of dry sand were determined. These results may be used to help reduce the risk of class D fires and improve the response abilities.

• Journal of the Korea Society of Computer and Information
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• v.23 no.11
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• pp.143-149
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• 2018

The purpose of this study is to propose a management method to maintain the pleasant indoor air quality of the dental clinic by measuring and analyzing the indoor air quality of the dental clinic. The measurement was conducted in two rooms, a lobby where many residents stay in the reception room for waiting for medical treatment, and a VIP room where treatment activities are mainly performed. Measurement items are Temperature, Humidity, $CO_2$, CO, $NO_2$, $CH_2O$, VOC, $PM_{10}$ and measurement were taken on April 27, 2018. As a result of analyzing the temperature and humidity of the dental clinic, it was analyzed that the average indoor temperature was maintained at $25^{\circ}C$ and the humidity was kept at around 50%, maintaining proper indoor temperature and humidity environment. $CO_2$ was 855ppm in the VIP Room, which satisfied the maintenance standard. In the case of the lobby, it was analyzed to be 1,160ppm, which exceeded the maintenance standard and it is judged that the carbon dioxide generated by the respiration of the people staying in the lobby is the main reason. The mean concentration of formaldehyde in the VIP room was analyzed as $436{\mu}g/m^3$, exceeding the maintenance standard, and $2,100{\mu}g/m^3$ for the VOC exceeded the recommended standard. It was analyzed that the concentration was relatively higher due to the use of disinfectant and other drugs. The mean concentration of PM-10 in the lobby was analyzed as $65{\mu}g/m^3$ and it was analyzed that it satisfied the maintenance standard. To maintain a pleasant indoor air quality in a dental clinic it is necessary to minimize the effects of formaldehyde, VOC, $CO_2$ in the VIP rooms and lobby. For this purpose, the entire ventilation system and air purification system of the dental clinic should be installed. In case of the VIP room, local exhaust ventilation should be installed and workers should wear personal protective equipment.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.168-168
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• 2022

According to the 5th Climate Change Report, global average temperature in 2081~2100 will increase 1.8℃ based on RCP 4.5 and 3.7℃ based on RCP 8.5 from the current climate value (IPCC Working Group I AR5). As temperature is expected to increase due to global warming and the intensity and frequency of rainfall are expected to increase, damage to crops is expected, and countermeasures must be taken. This study intends to evaluate rice growth in terms of nitrogen utilization efficiency according to future climate change conditions. In this experiment, Oryza sativa cv. Shindongjin were planted at the SPAR facility of the NICS in Wanju-gun, Jeollabuk-do on June 10, and were planted and grown according to the standard cultivation method. Cultivation conditions are high temperature, high CO₂ (current temperature+4.7℃·CO₂ 800ppm), high temperature (current temperature+4.7℃·CO₂ 400ppm), current climate (current tempreture·CO₂ 400 ppm). Nitrogen was varied as 0, 9, 18 kg/10a. The N content and C/N ratio of all rice leaves, stems, and seeds increased at high temperature, and the N content and C/N ratio decreased under high temperature and high CO₂ conditions com pared to high temperature. Compared to the current climate, NUE increases by about 8% under high temperature and high CO₂ conditions and by about 2% under high temperature conditions. This seems to be because the increase in temperature and CO₂ induced the increase in biomass. ANUE related to yield decreased by about 70% compared to the current climate under high temperature conditions, and decreased by about 45% at high temperature and high CO₂, showing a tendency to decrease compared to high temperature. This appears to be due to reduced fertility and poor ripening due to high temperature stress. However, as the nitrogen increased, the number of ears and the number of grains increased, slightly offsetting the production reduction factor.