• Applied Chemistry for Engineering
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• v.19 no.5
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• pp.574-581
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• 2008

The optimum regeneration conditions for the regeneration of three way spent catalysts (TWCs), which were taken from automobiles with different driving conditions, were investigated to evaluate the suitability as alternative catalysts for removing VOCs. The spent catalysts were washed with five different acids ($HNO_3$, $H_2SO_4$, $C_2H_2O_4$, $C_6H_8O_7$, and $H_3PO_4$) to remove contaminants and examine the optimum conditions for recovering the catalytic activity. The physicochemical properties of spent and its regenerated TWCs were evaluated by using nitrogen adsorption-desorption isotherms, XRD, and ICP. The relative atomic ratios of contaminants and platinum group metals (PGMs) of the spent TWCs were greatly dependent on the placed positions. The main contaminants formed were lubricant oil additives and metallic components. Also, the regeneration treatment increased the PGMs ratio, BET surface area, and average pore diameter of TWCs. The catalytic activity results indicated that the spent TWCs have the possibility for removing VOCs. Moreover, the employed acid treatments greatly enhanced the catalytic activity of the spent TWCs. Especially, nitric and oxalic acids provided the most improvement in the catalytic behavior. The catalytic activities of the regenerated TWCs were significantly influenced by the containing platinum ratios rather than the removal ratios of contaminants and the changes in the structural properties offered by the acid treatments.

• Fire Science and Engineering
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• v.34 no.3
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• pp.67-75
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• 2020

In this study, the risk of heat generation due to normal and overload currents that vary with the abnormal loosening angle of wire-connecting bolts were identified. The risks were analyzed based on the thermal characteristics to minimize the carbonization accidents of terminal blocks inside distribution panels typically used in industrial sites. We applied a method for measuring the heating temperature and temperature variations in the terminal blocks in real-time by installing a resistance temperature detector sensor board in the terminal block. The experimental results showed that the terminal block model with a low-rated current exhibited a higher heating temperature, thus, confirming the need to select the terminal block capacity based on load currents. Additionally, the higher the rated current of the terminal block with a high-rated current and the higher the degree of loosening, the faster the carbonization point. Such heating temperature monitoring enabled real-time thermal temperature measurement and a step-by-step risk level setting through thermal analysis. The results of the measurement and analysis of carbonization risks can provide a theoretical basis for further research regarding the risk of fire due to carbonization. Furthermore, the deterioration measurement method using the temperature sensor board developed in this study is widely applicable to prevent fires caused by poor electrical contact as well as risk-level management.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.38 no.3
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• pp.211-222
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• 2020

The purpose of this study is to derive a plan to improve the standard of survey cost, which is a system for estimating survey cost operated by the National Geographic Information Institute. The current standard has not been revised significantly since the initial enactment. However, in the situation where the survey industry is getting worse, the actualization of the standard is an urgent task for training engineers and industrial development. In this study, in order to break the problems of the standard and to derive improvement plan, we analyzed the outline, basic characteristics, and history of the standard and compared it with similar domestic ones. We collected opinions from the government and the industry through a survey, and verified labor cost and overhead rates. The conclusions are as follows. First, it is necessary to complement standard for production rate that directly affects direct cost, and to compensate for the missing items in the direct cost. Second, when compared with cost standards in foreign countries and cadastre field, the labor cost in survey field was found to be very low and improvement is needed. Third, the overhead rates were assessed to be appropriate, and the problem of improper overhead design should be coped with by strengthening education and promotion. Fourth, it is necessary to consider the introduction of deliberation committee or standard market price system for rapid response to new technologies.

• 대한공업교육학회지
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• v.40 no.2
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• pp.44-71
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• 2015

This study is aimed to analyze the cognitive level of basic job skill for students, graduates, and teachers in a specialized high school, as well as for workers in a company, and to suggest an optimal educational curriculum by deciding the priority of the basic job skill in education in the field of mechanic, electric electronic semiconductor, and architecture civil engineering construction. This research was undertaken with the use of various statistic skills, the Borich method, and the locus for focus model. Also, this research shall be valued in synthetic understandings for curriculum revising. The educational priority which shall be applied to the mechanic, electric electronic semiconductor, and architecture civil engineering construction at specialized high school was analyzed, and according to this, a new curriculum was suggested. For mechanic, it put its educational priority on Expressing oneself, Problem solving, Self-development, Career development, Managing time, Negotiation, and Understanding technology. For electric electronic semiconductor, its focus was on Managing time, and for architecture civil engineering construction, they emphasized Problem solving, Self-development, Career development, Managing time, and Conflict management.

• Environmental Engineering Research
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• v.13 no.3
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• pp.131-135
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• 2008

In this study, Fe(VI) was employed as a multi-functional agent to treat the simulated industrial wastewater contaminated with Cu(II)-EDTA through oxidation of EDTA, decomplexation of Cu(II)-EDTA and subsequent removal of free copper through precipitation. The decomplexation of $10^{-4}\;M$ Cu(II)-EDTA species was performed as a function of pH at excess concentration of Fe(VI). It was noted that the acidic conditions favor the decomplexation of Cu(II)-EDTA as the decomplxation was almost 100% up to pH 6.5, while it was only 35% at pH 9.9. The enhanced degradation of Cu(II)-EDTA with decreasing the pH could be explained by the different speciation of Fe(VI). $HFeO_4^-$ and $H_2FeO_4$, which are relatively more reactive than the unprotonated species $FeO_4^{2-}$, are predominant species below neutral pH. It was noted that the decomplexation reaction is extremely fast and within 5 to10 min of contact, 100% of Cu(II)-EDTA was decomplexed at pH 4.0. However, at higher pH (i.e., pH 10.0) the decomplexation process was relatively slow and it was observed that even after 180 min of contact, maximum ca 37% of Cu(II)-EDTA was decomplexed. In order to discuss the kinetics of the decomplexation of Cu(II)-EDTA, the data was slightly fitted better for the second order rate reaction than the first order rate reaction in the excess of Fe(VI) concentration. On the other hand, the removal efficiency of free Cu(II) ions was also obtained at pH 4.0 and 10.0. It was probably removed through adsorption/coagulation with the reduced iron i.e., Fe(III). The removal of total Cu(II) was rapid at pH 4.0 whereas, it was slow at pH 10.0. Although the decomplexation was 100% at lower pH, the removal of free Cu(II) was relatively slow. This result may be explicable due to the reason that at lower pH values the adsorption/coagulation capacity of Fe(III) is greatly retarded. On the other hand, at higher pH values the decomplexation of Cu(II)-EDTA was partial, hence, slower Cu(II) removal was occurred.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.6
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• pp.269-276
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• 2017

In this study, a test was conducted to examine the effects of micro-needle therapy (MTS) and cosmetics containing spirulina on improving the skin tone, skin hydration, hyper-pigmentation, and fine lines of middle-aged women in their 40s and 50s and to propose an effective skin care method. The subjects were divided into a control group of eight people who used serum and cream mask that does not contain MTS and spirulina, and an experimental group who used serum and cream containing MTS and spirulina. The test was conducted with six 30-minute sessions for one week. The change in skin was measured over three times in the week of the test, after six weeks of the test, and two weeks after the test had finished. The result showed that after six weeks of the test, in the experimental group, the skin tone (color brightness, saturation brightness, skin brightness) and moisture showed a significant increase (p<0.05), while the number of small hyper-pigmentation and large hyper-pigmentation, as well as the length of crow's feet, melanin, erythema showed a significant reduction (p<0.05). No significant differences in fine lines under the eyes and length of crow's feet were observed. Two weeks after the test was finished, the experimental group showed a significant decrease in the length of crow's feet and melanin (p<0.05), and a significant increase in skin brightness and moisture (p<0.05). Even after the test was completed, the skin brightness, fine lines, melanin, and moisture improved continuously. In conclusion, skin care using MTS and cosmetics containing spirulina was more effective on improving the skin tone, hydration, hyper-pigmentation, and fine lines, than skin care without using them.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.5
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• pp.2178-2188
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• 2012

This study is based upon 200 final responses from a survey conducted for 153 nurses and 147 nursing students in Busan and Gyeongnam province from september to october 2011. It is carried out to compare and understand the spiritual needs of nurses and nursing students that are inclined to be more exposed unhealthy people rather than healthy people. In this study, the level of spiritual care needs was divided into five fields such as 'love and fellowship', 'hope and peace', 'meaning and purpose of life', 'acceptance of death' and 'relationship with God' and was investigated. As a result, the love and fellowship was the highest level in group of nurses (r = 3.82) and the relationship with God was the lowest one (r = 2.73). In contrast, a group of nursing students showed that love and fellowship was the highest level (r = 3.92) and relationship with God was the lowest (r = 2.99) among five fields. There were statistical significances between nurses and nursing students in 'acceptance of death' and 'relationship with God' (p < 0.05). When looking at correlation between fields of spiritual needs of nurses, the correlation between 'meaning and purpose of life' and 'hope and peace' was the highest (r = .699) and the correlation between 'relationship with God' and 'hope and peace' was the lowest (r = .247). As the result of analysis on correlation between fields of spiritual needs of nursing students, the correlation between 'meaning and purpose of life' and 'hope and peace' was the highest (r = .660) and the correlation between 'acceptance of death' and 'relationship with God' was the lowest (r = .277). Therefore, it would be imperative to develop a more efficient and systemized education program for the spiritual care of nursing patients, on the basis of understanding the spiritual needs of nurses and nursing students.

• Applied Chemistry for Engineering
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• v.21 no.1
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• pp.6-10
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• 2010

In order to research the effect of solvents of extract on biological activities of Phyllostachys nigra Munro, antioxidative activity, superoxide dismutase (SOD)-like activity, nitrite scavenging activity, tyrosinase inhibitory activity, angiotensin-converting enzyme (ACE) inhibibitory activity in vitro were investigated. When ethyl acetate and hexane as solvents were used, the total phenols concentrations were 44.1 and 47.3 mg/kg, respectively, which was about 2.0 fold higher than that of water. The antioxidive activity was affected by solvents of extraction. The antioxidative activity was increased in order of hexane > ethyl acetate > n-butanol > methanol > water extraction. On the other hand, in the case of SOD-like activity, it was in the order of methanol > n-butanol > hexane > ethyl acetate extraction. The nitrite scavenging ability showed the most remarkable activity at pH 1.2 irrespective of solvents. Especially, when pH was increased from 1.2 to 6.0 using ethyl acetate extraction, it was decreased from 69.2 to 7.8%. The tyrosinase inhibitory activity was in the range of 15.2~21.3% and was increased in order of water > methanol > n-butanol>hexane > ethyl acetate extract. These results suggest that hexane and ethyl acetate extraction of Phyllostachys nigra Munro can be used in bioactive and functional materials.

• Korean Journal of Construction Engineering and Management
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• v.13 no.4
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• pp.120-131
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• 2012

Today, companies exist amid unlimited competition and uncertain adminstration environment, so hands-on workers are being exposed to various job requirements and stress due to this. Especially, employees in the design firm are physically difficult because of heavy working intensity unlike other industrial field, and because the process is interrelated unlike working of a five-day workday of the other industry, it is difficult to guarantee periodic holidays and vacation. In addition, recently, while BIM is introduced in the construction industry, various changes in the individual role as well as organizational dimension such as business environment and scope & role, etc. are required, so it is the actual situation that the category and factors of job stress due to this are being also changed. Accordingly, this research has grasped important and weak sectors according to characteristics such as career, position, gender, education and existence/nonexistence of BIM template, etc. by confirming a job stress level and inducing factors of hands-on workers at the design firm. This research has a meaning in constructing a business environment of a design firm that is a main participant of BIM-based projects that are expected to have high utilization in the future.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.251-251
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• 2016

For several decades, industrial processes consume a huge amount of raw water for various objects that consequently results in the generation of large amounts of wastewater. Wastewaters are consisting of complex mixture of different inorganic and organic compounds and some of them can be toxic, hazardous and hard to degrade. These effluents are mainly treated by conventional technologies such are aerobic and anaerobic treatment and chemical coagulation. But, these processes are not suitable for eliminating all hazardous chemical compounds form wastewater and generate a large amount of toxic sludge. Therefore, other processes have been studied and applied together with these techniques to enhance purification results. These include photocatalysis, absorption, advanced oxidation processes, and ozonation, but also have their own drawbacks. In recent years, electrochemical techniques have received attention as wastewater treatment process that could be show higher purification results. Among them, boron doped diamond (BDD) attract attention as electrochemical electrode due to good chemical and electrochemical stability, long lifetime and wide potential window that necessary properties for anode electrode. So, there are many researches about high quality BDD on Nb, Ta, W and Si substrates, but, their application in effluents treatment is not suitable due to high cost of metal and low conductivity of Si. To solve these problems, Ti has been candidate as substrate in consideration of cost and property. But there are adhesion issues that must be overcome to apply Ti as BDD substrate. Al, Cu, Ti and Nb thin films were deposited on Ti substrate to improve adhesion between substrate and BDD thin film. In this paper, BDD films were deposited by hot filament chemical vapor deposition (HF-CVD) method. Prior to deposition, cleaning processes were conducted in acetone, ethanol, and isopropyl alcohol (IPA) using sonification machine for 7 min, respectively. And metal layer with the thickness of 200 nm were deposited by DC magnetron sputtering (DCMS). To analyze microstructure X-ray diffraction (XRD, Bruker gads) and field emission scanning electron microscopy (FE-SEM, Hitachi) were used. It is confirmed that metal layer was effective to adhesion property and improved electrode property. Electrochemical measurements were carried out in a three electrode electrochemical cell containing a 0.5 % H2SO4 in deionized water. As a result, it is confirmed that metal inter layer heavily effect on BDD property by improving adhesion property due to suppressing formation of titanium carbide.