• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.9
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• pp.971-978
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• 2012

Vacuum carburizing is supposed to be the superior process to the gas carburizing. However, the vacuum carburizing has the stage in which hydrocarbon gas is supplied into the furnace to be pyrolysis, and consequently the stable heat treatment is hard to achieve due to the soot from the hydrocarbon pyrolysis. Recently, many studies have been made which utilize acetylene gas to overcome this defects. In this paper, the carburizing and the diffusion periods have been selected based on the Harris experimental formula, and the mechanical properties of the vacuum carburized specimen have been compared with those of the gas carburized SCM415H specimen to identify the feasibility of the $CO_2$ free vacuum carburizing process. The result showed that the vacuum carburized materials used have no oxidization of the grain boundaries, and show the 29.8% higher effective hardness depth and the acceptable tensile strength.

• Korean Journal of Heritage: History & Science
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• v.48 no.1
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• pp.148-165
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• 2015

Iron was one of the most influential factors for formation and development of ancient countries. The diffusion of ironware had increased agricultural productivity and brought about military technical revolution. Needless to say, the rise and fall of the countries depended on the possession of stable iron production. Raw materials and fuels are the key factors for mass production of iron and a transportation route is essential to supply the goods. Jungwon area satisfies the three factors. There are many iron manufacture sites such as Jincheon Seokjang-ri Gusan-ri, and Chunju Chilgeum-dong Tangeumdae earthen ramparts in the Jungwon area. In order to study the ancient iron manufacture technique, reconstitution experiment was carried out using restored furnace which was made based on the Jincheon Seokjang-ri B-23 furnace. Some notable results were identified with the experiment as in the followings. Firstly, a roasting process has a connection with the decrease of hardness of the iron ore. Secondly, melting of the blast pipe as well as the formation of product within the furnace had a crucial effect on the cessation of the experiment. Thirdly, reduced iron in various locations within the furnace prove that there was enough reducing environment during the working. Not only melting point but also properties of iron can vary depending on the carbon contents. For the reason, formation of approximate environment in which iron can react to the chalcoal is the most important factor in terms of iron manufacture.

• Korean Journal of Clinical Laboratory Science
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• v.53 no.1
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• pp.19-31
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• 2021

This study aimed at comparing the performance of imported LX detergent cleaning solution (LX-CS) and the self-manufactured OC cleaning solution (OC-CS), based on functional and quantitative analysis. The functional analysis was carried out using apparent diffusion coefficient (ADC) values. For quantitative analysis, precision, linearity, and carry-over rates were measured with commercial control materials according to the Clinical and Laboratory Standards Institute (CLSI) guidelines. Using OC-Sensor PLEDIA (Eiken Chemical, Japan), the ADC value of all cuvettes satisfied the acceptance criteria. For quantitative analysis, precision was less than 5.0% for the two products, and carry-over rates were less than ±1.00%. The linearity slopes and r2 values were 1.0017 and 0.9982 in the LX-CS, and 0.9924 and 0.9996 in the OC-CS, respectively. The correlation coefficient (r) was found to be 0.9997. Also, the percent difference in correlation with 40 artificial-stool specimens was less than 10% and the p-value was less than 0.1. The result of standard deviation ratio (D: ±1 SD ratio) was similar for both products. In conclusion, the functional and quantitative analyses of the two products were compared and showed similar results. In the future, the self-manufactured OC-CS will be able to provide a much more stable and faster supply than the imported LX-CS.

• Korean Journal of Radiology
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• v.20 no.5
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• pp.854-861
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• 2019

Objective: To evaluate quantitative magnetic resonance imaging (MRI) parameters for differentiation of cysts from and solid masses in the anterior mediastinum. Materials and Methods: The development dataset included 18 patients from two institutions with pathologically-proven cysts (n = 6) and solid masses (n = 12) in the anterior mediastinum. We measured the maximum diameter, normalized T1 and T2 signal intensity (nT1 and nT2), normalized apparent diffusion coefficient (nADC), and relative enhancement ratio (RER) of each lesion. RERs were obtained by non-rigid registration and subtraction of precontrast and postcontrast T1-weighted images. Differentiation criteria between cysts and solid masses were identified based on receiver operating characteristics analysis. For validation, two separate datasets were utilized: 15 patients with 8 cysts and 7 solid masses from another institution (validation dataset 1); and 11 patients with clinically diagnosed cysts stable for more than two years (validation dataset 2). Sensitivity and specificity were calculated from the validation datasets. Results: nT2, nADC, and RER significantly differed between cysts and solid masses (p = 0.032, 0.013, and < 0.001, respectively). The following criteria differentiated cysts from solid masses: RER < 26.1%; nADC > 0.63; nT2 > 0.39. In validation dataset 1, the sensitivity of the RER, nADC, and nT2 criteria was 87.5%, 100%, and 75.0%, and the specificity was 100%, 40.0%, and 57.4%, respectively. In validation dataset 2, the sensitivity of the RER, nADC, and nT2 criteria was 90.9%, 90.9%, and 72.7%, respectively. Conclusion: Quantitative MRI criteria using nT2, nADC, and particularly RER can assist differentiation of cysts from solid masses in the anterior mediastinum.

• Tuberculosis and Respiratory Diseases
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• v.53 no.4
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• pp.369-378
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• 2002

Background : The effects of chemotherapy on pulmonary function are mainly a reduced diffusion capacity and a restrictive ventilatory impairment. Exercise can expose cardiovascular and pulmonary abnormalities not evident at rest. Exercise related cardiopulmonary function is important in patients with malignant disease as a determinant of quality of life. We performed this study to evaluate the changes of body composition and cadiopulmonary exercise perfoemance of patients with locally advanced, non-small cell, lung cancer (NSCLC) before and after chemotherapy. Methods : We evaluated resting pulmonary function, body composition, physiologic performance status, and cardiopulmonary exercise function in 11 patients with locally advanced NSCLC, at diagnosis and prior to the fourth cycle of chemotherapy. Results : After chemotherapy, 4 patients (36.4%) showed partial response and 7 (63.4%) had stable disease. After chemotherapy, diffusion capacity of the lung for carbon monoxide was reduced ($89.7{\pm}34.1%$, vs. $71.9{\pm}20.5%$) but not significantly. There were no significant changes in body composition or the state of physiologic performance after chemotherapy. There was a significant impairment of cardiopulmonary exercise tolerance in patients with NSCLC, evidenced by a reduction of maximal oxygen uptake ($VO_2$max, ml/kg/min, $17.9{\pm}2.6$ : $12.6{\pm}6.1$, <0.05) and $O_2$pulse ($O_2$ pulse, ml/beat, $7.0{\pm}1.7$, $5.2{\pm}2.1$, <0.05). Conclusion : Systemic chemotherapy resulted in a loss of cardiopulmonary exercise function in patients with locally advanced NSCLC within the short-term period, but not a physiologic change of body composition within the same period.

• Journal of the Mineralogical Society of Korea
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• v.22 no.3
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• pp.177-189
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• 2009

Iron (oxyhydr)oxides commonly form as secondary minerals of high reactivity and large surface area resulting from alteration and weathering of primary minerals, and they are efficient sorbents for inorganic and organic contaminants. Accordingly, they have a great potential in industrial applications and are also of substantial interest in environmental sciences. Goethite (${\alpha}$-FeOOH) is one of the most ubiquitous and stable forms of iron (oxyhydr)oxides in terrestrial soils, sediments, and ore deposits, as well as a common weathering product in rocks of all types. This study focused on adsorption reaction as a main mechanism in scavenging arsenic using goethite. Goethite was synthesized in the laboratory to get high purity, and a variety of mineralogical and physicochemical features of goethite were measured and related to adsorption characteristics of arsenic. To compare differences in adsorption reactions between arsenic species, in addition, a variety of experiments to acquire adsorption isotherm, adsorption edges, and adsorption kinetics were accomplished. The point of zero charge (PZC) of the laboratory-synthesized goethite was measured to be 7.6, which value seems to be relatively higher, compared to those of other iron (oxyhydr)oxides. Its specific surface area appeared to be $29.2\;m^2/g$ and it is relatively smaller than those of other (oxyhydr)oxides. As a result, it was speculated that goethite shows a smaller adsorption capacity. It is likely that the affinity of goethite is much more larger for As(III) (arsenite) than for As(V) (arsenate), because As(III) was observed to be much more adsorbed on goethite than As(V) in equivalent pH conditions. When the adsorption of each arsenic species onto goethite was characterized in various of pH, the adsorption of As(III) was largest in neutral pH range (7.0~9.0) and decreased in both acidic and alkaline pH conditions. In the case of As(V), the adsorption appeared to be highest in the lowest pH condition, and then decreased with an increase of pH. This peculiarity of arsenic adsorption onto goethite might be caused by macroscopic electrostatic interactions due to variation in chemical speciation of arsenic and surface charge of goethite, and also it is significantly affected by change in pH. Parabolic diffusion model was adequate to effectively evaluate arsenic adsorption on goethite, and the regression results show that the kinetic constant of As(V) is larger than that of As(III).

• Journal of Life Science
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• v.19 no.7
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• pp.994-1002
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• 2009

A bacteriocin-producing bacterium identified as Bacillus licheniformis was isolated from soybean sauce. Antibacterial activity was confirmed by paper disc diffusion method, using Micrococcus luteus as a test organism. The bacteriocin also showed antibacterial activities against Bacillus sphaericus, Lactobacillus bulgaricus, Lactobacillus planiarum, Paenibacillus polymyxa, and Pediococcus dextrinicus. Optimal culture conditions for the production of bacteriocin was attained by growing the cells in an MRS medium at a pH of 6.5~ 7.0 and a temperature of 37$^\circ$C for 36$\sim$48 hr. Solvents such as chloroform, ethanol, acetone, and acetonitrile had little effect on bacteriocin activity. However, about 50% of bacteriocin activity diminished with treatment of methanol and isopropanol at the final concentration of 50% at 25$^\circ$C for 1 hr. It was stable against a pH variation range from 3.0 and 7.0, but the activity reduced to 50% at a pH range from 9.0 to 11.0. It's activity was not affected by heat treatment at 100$^\circ$C for 30 min and 50% of activity was retained after heat treatment at 100$^\circ$C for 60 min, showing high thermostability. The bacteriocin was purified to a homogeneity through ammonium sulfate precipitation, SP-Sepharose ion-exchange chromatography, and reverse-phase high-performance liquid chromatography (HPLC). The entire purification protocol led to a 75-fold increase in specific activity and a 13.5% yield of bacteriocin activity. The molecular weight of purified bacteriocin was estimated to be about 2.5 kDa by tricine-SDS-PAGE.

• Korean Journal of Food Science and Technology
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• v.42 no.2
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• pp.155-159
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• 2010

The antimicrobial activity of Sargassum fulvellum (SF) was investigated using the agar diffusion assay and MIC test. In addition, the stability of this activity under extreme heat and pH conditions was examined. The SF ethanol extract was shown to display strong antimicrobial activities against B. subtilis, C. perfringens, L. plantarum, S. aureus, L. monocytogenes, S. cerevisae and C. tropicalis in the agar diffusion assay at the concentration of 4 mg/mL. The MIC value of the SF ethanol extract against the tested microbes ranged from 0.05 to 0.0063%. In the heat and pH stability test, the antimicrobial activity of the SF ethanol extract was not altered when the temperature was maintained at $121^{\circ}C$ for 15 min, and it was also not affected in the pH range of 2-10. These results suggest that the SF ethanol extract is highly stable against drastic changes in temperature and pH.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.9 no.5
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• pp.69-81
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• 2014

There is a growing interest in the technology transfer and commercialization both at home and abroad. Accordingly, this study looked at the concept of technology transfer and commercialization, identified the factors that should be taken into account in order to facilitate technology transfer and commercialization, and then performed a empirical analysis. As for the conventional technology transfer and commercialization, there was a tendency to limit its scope to the exploration, transfer and commercialization of technology itself. Here in this research, technology transfer and commercialization is defined the category to expand as various activities implemented in order to make sure that intellectual properties such as intangible technological developments, know-how, and knowledge are transferred between the relevant parties through a contract or negotiation, and the party to which the transfer is made can then further develop and exploit the technology into tangible products and other activities to obtain economic benefit out of that. In addition, the findings of the positive analysis of technology transfer and commercialization revealed that the focus of facilitating technology transfer has been on the technology itself, its management and securing efficiency of the systems and institutions involved in the technology transfer and commercialization. So there was lack of recognition as to the importance of financial support given to the phase of technology commercialization. This indicates that when it comes to the technology transfer and commercialization, quantitative performance has been the focus of interest such as patent application, registration, number of technology transfers, royalty, etc. So there was not enough understanding as to the issues of starting up a business, creating quality jobs through technology transfer and commercialization, which are directly related to the realization of the creative economy. In this regard, this research is expected to be used for the development for the future policies to boost technology transfer and commercialization as it suggests not only simply ensuring quantitative performance but also necessary to create the environment for the creation of the stable ecosystem for the parties involved in the technology transfer and commercialization and then to build circumstances in which creative economy can be realized.

• Microbiology and Biotechnology Letters
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• v.36 no.3
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• pp.227-232
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• 2008

Biological antagonists of Phytophthora capsici were isolated from soil in Gyeongbuk, Korea. Among the isolated bacteria, a Bacillus sp. was identified from l6S rDNA sequence analysis and named Bacillus sp. AM-651. Bacillus sp. AM-65l strain which can strongly a antifungal activity against Phytophthora capsici. Culture conditions for the maximum production of the antagonistic substance were optimized. The production of antibiotic were high on modified Davis mineral medium pH 7 at $30^{\circ}C$. The medium for highest production of the agonistic substance optimized. It is composed the best activity on glucose, $(NH_4)_2SO_4$ and $K_2HPO_4$ at 0.5%, 0.1%, and 0.7%, respectively. By time course of culture solution selected Bacillus sp. AM-65l, the culture solution after 48hrs had strongly growth inhibition rate against P. capsici. And culture solution of Bacillus sp. AM-651 was stable within a pH range $5{\sim}11$ and temperature range $4{\sim}70^{\circ}C$. Bacillus sp. AM-651 cultured broth shown fungal growth inhibitory activity against B. sorokiniana, B. cinerea, R. solani avove and beyond P. capsici and comparatively showed a high activity against C. gloeosporioides, B. dothidea, B. cinerea and F. graminearum by agar diffusion method.