• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2016.11a
• /
• pp.189-189
• /
• 2016

In this study, the Al-rich AlTiSiN thin films that consisted of TiN/AlSiN nano-multilayers were deposited on the steel substrate by magnetron sputtering, and their high-temperature oxidation behavior was investigated, which has not yet been adequately studied to date. Since the oxidation behavior of the films depends sensitively on the deposition method and deposition parameters which affect their crystallinity, composition, stoichiometry, thickness, surface roughness, grain size and orientation, the oxidation studies under various conditions are imperative. AlTiSiN nano-multilayer thin films were deposited on a tool steel substrate, and their oxidation behavior of was investigated between 600 and $1000^{\circ}C$ in air. Since the amount of Al which had a high affinity for oxygen was the largest in the film, an ${\alpha}-Al_2O_3-rich$ scale formed, which provided good oxidation resistance. The outer surface scale consisted of ${\alpha}-Al_2O_3$ incoporated with a small amount of Ti, Si, and Fe. Below this outer surface scale, a thin ($Al_2O_3$, $TiO_2$, $SiO_2$)-intermixed scale formed by the inwardly diffusing oxygen. The film oxidized slower than the $TiO_2-forming$ kinetics and TiN films, but faster than ${\alpha}-Al_2O_3-forming$ kinetics. During oxidation, oxygen from the atmosphere diffused inwardly toward the reaction front, whereas nitrogen and the substrate element of iron diffused outwardly to a certain extent.

• Journal of the Korean Society of Tobacco Science
• /
• v.22 no.2
• /
• pp.107-113
• /
• 2000

This study was carried out to investigate the changes in composition of the non-volatile organic acid, fatty acid and polyphenolic compounds during air-curing in burley tobacco leaves, and the effect of curing methods on the contents in air-cured leaves. The air-cured variety, (Nicotiana tabacum cv KB108) was normally grown at the Chonju tobacco experiment station in 1998. Plants designated for the each curing methods were harvested on the same date, and the ripe leaves for primed curing were harvested at the tenth leaf position from the top on the stalk. The major compounds of non-volatile organic acid and fatty acid were malic, citric, oxalic, palmitic, and linolenic acid. The concentrations of malic acid, unsaturated fatty acids, chlorogenic acid and rutin in cured leaves were remarkably decreased during curing, while citric acid was increased. The changes of these compounds showed the similar pattern during both primed and stalk curing. In connection with curing methods, the contents of malic, linoleic and linolenic acid were higher in excessive cured leaves than those in primed cured or stalk cured leaves, while the content of citric acid was lower in excessive cured leaves than that in primed cured or stalk cured leaves.

• Economic and Environmental Geology
• /
• v.20 no.1
• /
• pp.61-75
• /
• 1987

The Daejang mine is one of the representatives of Cu-Pb-Zn-(Ag) vein deposit related genetically to late Cretaceous granitoid in Korea. Sericite from an alteration halo of the mine yielded a K-Ar date of $95{\pm}3.5Ma$. Based on macrostructures of vein filling, three major mineralization stages (I, II and III) are distinguished by tectonic breaks. Major ore constituents are arsenopyrite, pyrite, pyrrhotite, sphalerite, chalcopyrite, galena, boulangerite, with small amounts of Ag-bearing tetrahedrite, pyrargyrite, native bismuth, marcasite, siderite, ankerite, gudmundite and calcite. Characteristic feature of each mineralization stage and compositional variation of sphalerite and arsenopyrite are discussed in relation to the genetic environments. The FeS contents of sphalerites are 20.5~14.9 mole % in stage I, 17.9~11.9 mole % in stage IIA, 17.0~9.2 mole % in stage IIB, and 6.9~4.7 mole % in stage III. Their results are indicative of decreasing FeS contents during mineralization process in sphalerite coexisting with sulfur-rich sulfide assemblages, such as monoclinic pyrrhotite and pyrite, and is agreement with the conclusions shown by Scott and Kissin(1973). The composition of arsenopyrite decrease also in As content from stage I to stage III, and the compositional variation correlate with position of the associated minerals in the paragenesis. Temperature and pressure of the mineralization are determined as $250{\sim}430^{\circ}C$ and 4.0~0.3kb respectively, based on the chemistry of the minerals.

• Biotechnology and Bioprocess Engineering:BBE
• /
• v.6 no.1
• /
• pp.6-10
• /
• 2001

The production of chitosan from the mycelia of Absidia coerulea was studied to improve cell growth and chitosan productivity. Culture conditions were optimized in batch cultivation (pH 4.5, agitator speed of 250 rpm, and aeration rate of 2 vvm) and the maximum chitosan concentration achieved was 2.3g/L under optimized conditions. Continuous culture was carried out successfully by the formation of new growth spots under optimized conditions, with a chitosan productivity of 0.052g/L(sup)-1 h(sup)-1, which is the highest value to date, and was obtained at a dulution rate of 0.05h(sup)-1. Cell chitosan concentrations reached about 14% in the steady state, which is similar to that achieved in batch culture. This study shows that for the continuous culture of Absidia coerulea it is vital to control the medium composition.

• Biotechnology and Bioprocess Engineering:BBE
• /
• v.5 no.4
• /
• pp.263-274
• /
• 2000

Carotenoids are widely distributed natural pigments which are in an increasing demand by the market, due to their applicatins in the human food, animal feed, cosmetics, and pharmaceutical industries. Although more than 600 carotenoids have been identified in nature, only a few are industrially important (${\beta}$-carotene, astaxanthin, lutein or lycopene). To date chemical processes manufacture most of the carotenoid production, but the interest for carotenoids of biological origin is growing since theire is an increased public concern over the safety of artificial food colorants. Although much interest and effort has been devoted to the use of biological sources for industrially important carotenoids, only the production of biological ${\beta}$-carotene and astaxanthin has been reported. Among fungi, several Mucorales strains, particularly Blakeslea trispora, have been used to develop fermentation processes for the production of ${\beta}$-carotene on almost competitive cost-price levels. Similarly, the basidiomycetous yeast Xanthophyllomyces dendrorhous (the perfect state of Phaffia rhodozyma), has been proposed as a promising source of astaxanthin. This paper focuses on recent findings on the fungal pathways for carotenoid production, especially the structure and function of the genes involved in the biosynthesis of carotenoids in the Mucorales. An outlook of the possibilities of an increased industrial production of carotenoids, based on metabolic engineering of fungi for carotenoid content and composition, is also discussed.

• Korean Institute of Interior Design Journal
• /
• no.23
• /
• pp.116-123
• /
• 2000

The importance of evaluation in design activity has been increased. Specially, it is necessary to take into consideration of user's needs as design criteria nowadays. Through these evaluations, the comprehensive quality of architectural design could be substantially improved and play the part of recycling at least in cases of theme similar structures. By a viewpoint of library patrons, there have increased many problems In library environment because more library patrons use the reference room for their study since reform of university education was carried out In 1981. Therefore, after post occupancy evaluation and spatial-planning matters of architecture are taken into consideration in this study, the problems of the plan-composition on the existing structure is pointed out and introduced the concept of post occupancy evaluation to grope the solution. With the question about users's needs and the state of use in the K-University Library, this study aims to investigate the actual use circumstance of space and maintenance of facilities as well as giving the most relevant alternatives instead of already existing one. This also intends to propose the essential date to meet the users' sociopsychological needs and environment innovation when planning the university library.

• Journal of the Korean Chemical Society
• /
• v.14 no.1
• /
• pp.119-122
• /
• 1970

In those six kinds of diamine salt crystal of which their structures had already been determined up to date, commonly one molecule of diamine and two molecules of acid were combined; although the crystal of benzidine perchlorate, only one molecule each of benzidine and perchloric acid were combined. At the case of benzidine perchlorate, one molecule acts as the role of two molecules by coincidence of the center of symmetry point of both the lattice and molecule, and perchlorate ion is locating symmetrically between two -$NH_2$ groups of different benzidine molecule, therefore benzidine and acid could be combined together with 1:1 by mole ratio. When forming the salt with diamine and acid, the combining mole ratio would be determined in accordance with the relationship between the symmetry element that presented by the space group and the symmetry element of diamine salt melecule.

• The Journal of the Society of Korean Medicine Diagnostics
• /
• v.17 no.3
• /
• pp.241-252
• /
• 2013

Objectives The purpose of this study was to investigate the effects of walking exercise on diabetes mellitus indicator and vascular compliance of type 2 diabetes mellitus adults. Methods The subjects were 2 groups; exercise group(n=11, $age=57.36{\pm}8.74$), non-exercise group(n=10, $age=59.20{\pm}5.81$). Walking exercise five or more times a week, and more than 10,000 steps per day with writing the walking diary ordered to the exercise group. For date analysis, mean and standard deviation scores were calculated, and independent t-test was performed. Result After 45 days of walking exercise, weight (p <.01), abdominal obesity rate (p <.05), body fat mass (p <.05) showed significant difference between the groups. but diabetes indicators and vascular compliance tend to decreased in the exercise group, there was no significant difference between the groups. Conclusions Walking exercise is effective in improving body composition.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.47 no.2
• /
• pp.135-140
• /
• 2021

Since the first report of a nasal septal abscess (NSA) from a dental origin (1920), six articles have been published in the English literature to date. The most common cause of NSA is an infection of the nasal septal hematoma after trauma. This is a report of an uncommon cause of NSA with a dental origin. A PubMed search performed regardless of year and country using the terms ("nasal septal abscess") OR ("nasal septum abscess") initially yielded 229 articles. After screening, seven articles (eight patients) were selected. Addition of two related articles produced a total of nine articles (10 patients) to be included. The age of the included patients ranged from 7 to 69 years (mean, 32.82 years; standard deviation, ±23.86 years). The sex composition was as followed: males (n=7; 63.6%), females (n=4; 36.4%). Dental histories were various: periapical lesions, caries, extraction, endodontic therapy, and cystic lesions. The maxillary incisor dominated as the tooth of origin. Early diagnosis and treatment of NSAs are important to avoid not only facial deformity, but also severe complications (e.g., intracranial infection). If NSA is suspected in patients without facial trauma, the possibility of a dental origin, especially from the maxillary incisor area, should be considered.

• Fashion & Textile Research Journal
• /
• v.24 no.6
• /
• pp.775-781
• /
• 2022

As part of research to develop a permanent wave-reducing agent for hair, in the current study, 0.1%-1.0% of Polyquaternium-10 was added to a permanent reagent containing Nicotinoyl Dipeptide-23 to prepare the agent, which was tested on damaged hair. The pH change was relatively stable even after a date, but due to the hair's natural composition, 0.1%-0.6% of the Polyquaternium-10 concentration according to pH was suitable. The temperature safety experiment demonstrated it to be stable at a high temperature and at room temperature, but when a Polyquaternium-10 concentration of 0.9% or higher was added at 0℃, coagulation occurred. In terms of the force efficiency of permanent wave formation, wave efficiency lowered as the concentration increased: the longer the wave lasts, the lower the Polyquaternium-10 concentration. The permanent moisture content was found to be higher as the concentration of Polyquaternium-10 increased. Therefore, when Polyquaternium-10 is applied to the permanent wave-reducing agent, considering stability, permanent formation, durability, and moisture rate, the most suitable concentration was found to be that of Polyquaternium-10 in the cysteine-reducing agent. A novel finding from this study is that as the concentration of Polyquaternium-10 increases, the consistency of the permanent wave-reducing agent changes, shifting from a liquid to a viscous liquid formulation.