• Korean Chemical Engineering Research
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• v.54 no.6
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• pp.854-862
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• 2016

As the demand for a clean energy to replace fossil fuel being depleted increases, hydrogen energy is considered as a promising candidate for future energy source. Water electrolysis which produces hydrogen has high energy efficiency and stability but still has a large overpotential for oxygen evolution reaction (OER). In this study, $Co_3O_4$ catalysts with different morphology were prepared by spray pyrolysis from solutions which contain Co precursor and various organic additives (urea, sucrose, and citric acid), followed by post heat treatment. For the catalysts synthesized, X-ray diffraction (XRD) measurements were performed to identify their crystal structure. Morphology and surface shape of the catalysts were observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Surface area and pore volume were examined by nitrogen adsortpion & desorption tests and X-ray photoelectron spectroscopy (XPS) was conducted to confirm nitrogen doping. Linear sweep voltammetry (LSV) was carried out to investigate OER activity of $Co_3O_4$ catalysts. As a result, bare-$Co_3O_4$ which has high surface area and small particle size determined by spray pyrolysis showed high activity toward OER.

• Journal of Korean Academy of Nursing
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• v.20 no.3
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• pp.307-323
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• 1990

This Study was done to design and test an instrument to measure the health status of the elderly including physical, psychologyical and social dimensions. Data collection was done from July 18 to August 17, 1990. Subjects were 412 older persons in Korea. A convenience sample was used but the place of residence was stratified into large, medium and small city and rural areas. Participants located in Sudaemun-Gu, Mapo-Gu, and Kangnam-Gu, Seoul were interviewed by brained nursing students, and those in Chungju, Jonju, Chuncheon, and Jinju by professors of nursing colleges. Rural residents were interviewed by community health practioners working in Kungsang-Buk-Do, Kyngsang- Nam - Bo, Jonla Buk -Do, and Kyung Ki- Do. The tool developed for this study was a structured questionnaire based on previous literature and then tested for reliability and validity. This tool contained 20 physical health status items, 17 mental-emotional health status items and 38 social health status items. Physical health status items clustered in to six factors such as personal hygiene, activity, home management, digestive, sexual, sensory, and climination functions. Mental-emotional health status items clustered into two factors, mental health and emotional health. Social health status items clustered into seven factors, grandparent, parent, spouse, friend, kinships, group member and religious role functions. Data analysis included percentage, average, S.D., t-test and ANOVA. The results of the analysis were as follows : 1. The tool measuring the health status of the elderly and developed for this research had a relatively high reliavility indicated by a cronbach＝0.97793. 2. Average score of the subjects physical health status was 4, 054 in a 5 point likert scale, mentalemotional health status was 3.803, social health status was 2.939 and the total average was 3.521. The social status of the subjects was the lowest and the next was mental-emotional health status ; physical health status was the highest. 3. Educational background, perceived health status, the amount of pocket money were related to physical and mental-emotional health status and family structure was related mental-emotional physical and social health status. Occupation was related to physical and mental-emotional status. Area of residence was related to metal-emotional and social status. Source of living in the expeneses was related to physical and mental-emotional health status marital status to mental-emotional and social health status, and the number living in the home physical health status and religion to social health status. The following conciusions were derived from the above results ; 1. The health status of Korean elderly was relatively sound but social health status was the most vulnerable. The Social activity for Korean elderly is needed to improve social health. 2. Educational background, perceived health status and the amount of pocket money must be considered in the health assessment criteria of the elderly, Family structure, marial status, occupation, residence variables and sources of living expense must also be considered as significant. 3. A health education program based on the educational background of the elderly, and provision of an occupational socioeconomic welfare policy will be useful in order to increase social health status of Korean elderly.

• The Korean Journal of Ecology
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• v.17 no.1
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• pp.1-9
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• 1994

This study focuses on forest fires attributed to cigarette light, the main source of wild fires, by examining the characteristics of the fire types. It aims to present useful data for preventive measures. Statistics show that the average length of cigarette butts left after smoking is 30mm excluding filter for domestic cigarette smokers. Also the average thickness of litter layer in forests is 58.2mm throughout the nation. The value varies according to how often leaves were trodden by hikers : the accumulation amount of Mt. Sunchi. which is relatively protected from human disturbances, is 29.6% more than that of Mt. Kye-Ryong National Park. Aged trees such as Pznus rzgidu, Quercus acutissima and Larix leptolepis have relatively large inflammable contents, 2.43kg in 15 year-old stand and 2.55kg in 10 year-old stand. This study found out the following fact with regard to the start of lighting and the out-break of fire. Fire breaks out within five minutes in the sample(C), in which Zoysza gaponica and Populus X tomentiglandulosu has been tramped when the sample has 2~6 percent of moisture contents. Coniferous trees such as Pinus rigida and Larzx leptolepis do not burn easily while leaving charcoal. In contrast, deciduous trees with Zoysia japonzca and Populus X tomentiglandulosu are quick to catch fire. As a result of the experiments, it is proved that cigarette light is a very dangerous cause of wild fire especially for dry grass like Zoysia gaponica.

• Journal of Environmental Science International
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• v.11 no.5
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• pp.419-436
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• 2002

The current paper reports on the enhancement of O$_3$, CO, NO$_2$, and aerosols during the Asian dust event that occurred over Korea on 1 May 1999. To confirm the origin and net flux of the O$_3$, CO, NO$_2$, and aerosols, the meteorological parameters of the weather conditions were investigated using Mesoscale Meteorological Model 5(MM5) and the TOMS total ozone and aerosol index, the back trajectory was identified using the Hybrid Single-Particle Lagrangian Integrated Trajectory Model(HYSPLIT), and the ozone and ozone precursor concentrations were determined using the Urban Ashed Model(UAM). In the presence of sufficiently large concentrations of NO$\sub$x/, the oxidation of CO led to O$_3$ formation with OH, HO$_2$, NO, and NO$_2$ acting as catalysts. The sudden enhancement of O$_3$, CO, NO$_2$ and aerosols was also found to be associated with a deepening cut-off low connected with a surface cyclone and surface anticyclone located to the south of Korea during the Asian dust event. The wave pattern of the upper trough/cut-off low and total ozone level remained stationary when they came into contact with a surface cyclone during the Asian dust event. A typical example of a stratosphere-troposphere exchange(STE) of ozone was demonstrated by tropopause folding due to the jet stream. As such, the secondary maxima of ozone above 80 ppbv that occurred at night in Busan, Korea on 1 May 2001 were considered to result from vertical mixing and advection from a free troposphere-boundary layer exchange in connection with an STE in the upper troposphere. Whereas the sudden enhancement of ozone above 100 ppbv during the day was explained by the catalytic reaction of ozone precursors and transport of ozone from a slow-moving anticyclone area that included a high level of ozone and its precursors coming from China to the south of Korea. The aerosols identified in the free troposphere over Busan, Korea on 1 May 1999 originated from the Taklamakan and Gobi deserts across the Yellow River. In particular, the 1000m profile indicated that the source of the air parcels was from an anticyclone located to the south of Korea. The net flux due to the first invasion of ozone between 0000 LST and 0600 LST on 1 May 1999 agreed with the observed ground-based background concentration of ozone. From 0600 LST to 1200 LST, the net flux of the second invasion of ozone was twice as much as the day before. In this case, a change in the horizontal wind direction may have been responsible for the ozone increase.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.9
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• pp.1045-1050
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• 2014

$N_2O$(Nitrous Oxide) is known as the third major GHG(Green House Gas) following $CO_2$(Carbon Oxide) and $CH_4$(Methane). The GWP(Global Warming Potential) factor of $N_2O$ is 310 times as large as that of $CO_2$ because $N_2O$ in the atmosphere is very stable, and it becomes a source of secondary contamination after photo-degradation in the stratosphere. Investigation on the cause of the $N_2O$ formation have been continuously reported by several researchers on power sources with continuous combustion form, such as a boiler. However, in the diesel engine, research on $N_2O$ generation which has effected from fuel components has not been conducted. Therefore, in this research, author has investigated about $N_2O$ emission rates which was changed by nitrogen and sulfur concentration in fuel on the diesel engine. The test engine was a 4-stroke direct injection diesel engine with maximum output of 12 kW at 2600rpm, and operating condition of that was set up at a 75% load. Nitrogen and sulfur concentrations in fuel were raised by using six additives : nitrogen additives were Pyridine, Indole, Quinoline, Pyrrol and Propionitrile and sulfur additive was Di-tert-butyl-disulfide. In conclusion, diesel fuels containing nitrogen elements less than 0.5% did not affect $N_2O$ emissions in the all concentrations and kinds of the additive agent in the fuel. However, increasing of the sulfur additive in fuel increased $N_2O$ emission in exhaust gas.

• Parasites, Hosts and Diseases
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• v.49 no.4
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• pp.427-430
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• 2011

The aim of this study was to test the susceptibility of mice to Trypanosoma evansi treated with human plasma containing different concentrations of apolipoprotein L-1 (APOL1). For this experiment, a strain of T. evansi and human plasma (plasmas 1, 2, and 3) from 3 adult males clinically healthy were used. In vivo test used 50 mice divided in 5 groups (A to E) with 10 animals in each group. Animals of groups B to E were infected, and then treated with 0.2 ml of human plasma in the following outline: negative control (A), positive control (B), treatment with plasma 1 (C), treatment with plasma 2(D), and treatment with plasma 3 (E). Mice treated with human plasma showed an increase in longevity of $40.9{\pm}0.3$ (C), $20{\pm}9.0$ (D) and $35.6{\pm}9.3$ (E) days compared to the control group (B) which was $4.3{\pm}0.5$ days. The number of surviving mice and free of the parasite (blood smear and PCR negative) at the end of the experiment was 90%, 0%, and 60% for groups C, D, and E, respectively. The quantification of APOL1 was performed due to the large difference in the treatments that differed in the source plasma. In plasmas 1, 2, and 3 was detected the concentration of 194, 99, and 115 mg/dl of APOL1, respectively. However, we believe that this difference in the treatment efficiency is related to the level of APOL1 in plasmas.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.5
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• pp.361-366
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• 2017

As the recent development of computing architecture and application software technology, real world simulation, which is the ultimate destination of computer simulation, is emerging as a practical issue in several research sectors. In this paper, metal plate motion in a square shock tube for small time interval was calculated using a supercomputing-based fluid-structure-combustion multi-physics simulation tool called Illinois Rocstar, developed in a US national R amp; D program at the University of Illinois. Afterwards, the simulation results were compared with those from experiments. The coupled solvers for unsteady compressible fluid dynamics and for structural analysis were based on the finite volume structured grid system and the large deformation linear elastic model, respectively. In addition, a strong correlation between calculation and experiment was shown, probably because of the predictor-corrector time-integration scheme framework. In the future, additional validation studies and code improvements for higher accuracy will be conducted to obtain a reliable open-source software research tool.

• Fire Science and Engineering
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• v.30 no.6
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• pp.48-56
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• 2016

A crude oil leakage from a large atmospheric storage tank occurred on 4 April 2014 at 14:50 in Ulsan City, while storing the crude oil in the tank. Emergency Rescue Control Group was deployed in the scene. The company, Fire Service Headquarters and associated agencies got together in Command Post (CP) for discussing an effective corresponding strategy. Many solution plans were drafted in the debate such as power down, stopping the facilities, checking the density of inflammable gas, suppressing oil evaporation, moving the leaked crude oil to a nearby tank and a processing plant and avoiding marine pollution. All the solutions were carried out in cooperation with several agencies and partners. The oil leakage accident was successfully settled up within the process of responding, The Fire Service Headquarters and the company thought that the most important thing was the suppression of oil evaporation and the elimination of ignition source. With Fire Service Headquarters and several agencies' every effort, an explosion and a fire didn't occurred in the scene. This study suggest the improvement of the operating system in Emergency Rescue Control Group in case of petroleum leakage, explosion and fire accidents of atmospheric storage tank, different from a ordinary disaster. Assuming that petroleum leakage in atmospheric storage tank develop the explosion and fire accidents, the spreading speed of the flame and the burning time was experimented and compared with each other. Furthermore, this study concentrates on the effective field response plan prepared for the afterward explosion and fire accidents from petroleum leak in a storage tank, with the database experimented and analyzed in accordance with the angle of radiation in the foam nozzle and the pressure of pumping in a fire engine.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.10
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• pp.1507-1516
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• 2002

Meat and bone meal is a valuable protein and mineral source in diets of production animals and contributes to the protein, energy and mineral component of diets. The aim of the present study was to more accurately characterise the apparent ileal amino acid digestibility of meat and bone meals produced in New Zealand and evaluate routine in vitro assays used in practise to measure meat and bone meal quality. A total of 94 commercial meat and bone meals from 25 New Zealand rendering plants over a two and a half year period were analysed for proximates, gross energy, gross amino acid content (incl. hydroxyproline, hydroxylysine and lanthionine), apparent ileal amino acid digestibility, pepsin nitrogen digestibility, protein solubility and bone content. The mean crude protein content of the 94 meat and bone meal samples was 56.8% with a range of >35% units and a coefficient of variation of 9.8%. The mean crude fat and ash content were 10.0 and 28.4% respectively. These latter components showed a large range (16 and 43%, respectively) with coefficients of variation above 22%. Amino acid digestibility between samples was highly variable with lysine and sulphur amino acids digestibility ranging between 45.8-89.0 and 38.2-85.5%, respectively. Pearson correlation coefficients are presented between crude protein content and individual gross amino acids, crude protein content and individual digestible amino acid content, and pepsin N digestibility and individual digestible amino acid content. There was a significant relationship between the digestible amino acid nitrogen content and the crude protein content while pepsin nitrogen digestibility was not correlated to ileal amino acid nitrogen digestibility (r=-0.06). Meat meals with a high protein content had relatively low hydroxyproline and hydroxylysine levels something that was attributed to the levels of collagen from bone. The data indicated that lanthionine (formed upon heat treatment of cysteine with a hydroprotein) is not a good indicator of the heat treatment employed to meat and bone meals. Step-wise multiple regression equations to predict the apparent digestible content of amino acids from rapid in vitro assays are presented. The most selected variables included ash and crude fat content. In general the equations derived for the essential amino acids had a higher degrees of fit (R2) compared to the non-essential amino acids. The R2 for the essential amino acids ranged from 0.43 for histidine and 0.68 for leucine. These equations provide a means of more rapidly estimating the apparent ileal digestible amino acid content (protein quality) of meat and bone meal using standard analyses.

• The Journal of the Convergence on Culture Technology
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• v.6 no.3
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• pp.83-90
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• 2020

Recently, a growing number of copyright infringement websites have illegally copied and posted works such as broadcasting, movies and music, and posted advertisements to make profits. The research is aimed at finding solutions by analyzing the current status of advertisements on copyright infringement websites. The results of this study are as follows. First of all, there are many advertisements harmful to teenagers, such as casinos, betting, games, adult products, and adult meeting, which is necessary to deal with. Secondly, there were many unethical advertisements on copyright infringement websites, but there were also many advertisements from famous companies. Advertisements from large companies and famous brands are also being executed continuously, which can create trust in illegal sites. Therefore, the government, advertisers, citizens, and academia should participate in a campaign to root out the use of illegal websites because it is impossible to eradicate them by crackdown alone. In this paper, we pointed out the practical problems of advertising execution, the main source of revenue for copyright infringement websites, and presented a comprehensive solution.