• Korean Journal of Food Science and Technology
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• v.13 no.4
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• pp.261-266
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• 1981

In order to clarify the removal of astringency in persimmon fruits (Diospyros koki L.) and its mechanism, a comparative histology of tannin cells in tile cultivars of astringent persimmon fruits (Sangju Dungsi. Daegu Bansi. Cheongdo Bansi) and a sweet persimmon fruit (Fuyu) was observed. Tannin cells were widespread in all fruits tissue expert for tissue of ovule before full blossom. The epidermal cells of ovary. flower and calyx consist of tannin cell. Arrangement of tannin cells has radiated type toward the upper directions in the calyx. The major part of seed coat consisted of tannin cells. The epidermal cells of persimmon fruits were consisted of small tannin cells, and the inner part of epicarp of the astringent persimmon was consisted of stone cells, but the sweet persimmon was consisted of parenchymatous cells. It was suggested that differantiation of tannin cell In persimmon fruits occured until about the middle of August. Some tannin cells of matured astringent persimmon fruits was coagulated and wall of tannin cell produced protuberance, and most of tannin cells of matured sweet persimmon fruits was coagulated or ruptured.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.995-998
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• 2007

The number of households old over as much as 20 years is expected to get increased rapidly more than 1,000,000(1 million). As a measure to this fact remodeling is being revitalized over the country. parking lots expansion actually takes up a great deal of weight among the requirement for remodeling. When constructing a parking lot for enlargement, the way of going into the main building determines such construction features as selection of Retaining Wall Method, installation of an elevator, parking measure of capacity, etc. This study derived the affecting factors for selecting the way of going into the main building when constructing an underground parking lot. In a research way, we examined the features on each method of going into the main building in an apartment complex through an in-depth interview with some experts after investigating the method of enlarging an underground parking lot and going into the main building. After that, we derived the affecting factors for selecting the way of going into the main building. The affecting factors include constructability, convenience, economic efficiency as a high level as well as existence and nonexistence of basement and removal, safety of current building, parking measure of capacity, amenity, inhabitant traffic line, construction expenses and construction duration as a low one. This study will be applied as a reference for selecting the way of going into the main building when constructing an underground parking lot especially targetted on an old apartment house.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.10
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• pp.743-748
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• 2013

The purposes of this study are to prepare Hanji fiber-filter sheets using replacement liquid in water-swollen fiber with non-polar solvent such as ethanol, methanol and pentane. The experiments were studied on the selection of optimal non-polar solvent and the optimal drying method for wetted fiber and then were to know physicochemical characteristics of prepared Hanji fiber-filter sheet. The Ethanol as liquid changer in water-swollen fiber was excellent solvent and the optimal drying method for them was freeze drying served with vacuum pump. The bulk density and porosity of prepared fiber sheet from freeze dryer were 0.11-0.13 g/mL, half of natural dried fiber sheet, and 90%, respectively. The results of SEM observation for the fiber sheet prepared with natural drying or heating drying were shown very close structure of fiber wall in dry state. However, the freeze drying sheet were shown the open structure. So, the head loss of freeze drying sheet was very lower than natural drying and heating drying sheets. From the results of BTEX removal experiments, the sheets dried at water wetted condition was shown more higher efficiency than the fiber sheets dried at solvent wetted condition.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.2
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• pp.1204-1210
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• 2014

New control methods are proposed for indoor air quality by removing fine airborne dust-particles. As suspended fine dust-particles contain inorganic dust as well as fine organic bacteria, studies for simultaneous control of these contaminants are required. In this study, photocatalytic disinfection of indoor suspended microorganisms such as E. coli and Bacillus subtilis is performed by three types of photocatalysts with UVA irradiation. The UVA irradiation strength was controlled to the minimum $3{\mu}W/cm^2$, and ZnO, $TiO_2$, and ZnO/Laponite ball were used as the catalysts. The results indicate that E. coli was removed over 80 % after about 2 hours of reaction with UVA and all three types of photocatalysts, whereas only with UVA, around 50 % E. coli removal was obtained. Among the catalysts, ZnO/Laponite composite ball was found to have similar sterilizing capacity to $TiO_2$. However, in case of B. subtilis, which has thick cell wall in its spore state, disinfection was not effective under the low UVA irradiation condition, even with the catalysts. Further studies need to figure out the optimal UVA irradiation ranges as well as photocatalysts doses to control airborne dust, to provide healthy clean air environment.

• Restorative Dentistry and Endodontics
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• v.23 no.1
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• pp.477-486
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• 1998

Recently the development of rotary instrument makes it possible that in root canal treatment operator saves much more time, maintans original curved canal shape and easily prepares continuous tapered root canal. The purpose of this experiment was to examine the smoothness of the internal surface of prepared root canal and the effectiveness of debridement in prepared root canal by SEM for the comparison of hand and Ni-Ti rotary instrument. 25 extracted human teeth were access opened and # 10 K-type file was introduced into canal until it was appeared at the apical foramen. The working length was established by subtracting 0.5mm from this measurement. Group 1. The root canal preparation was done to # 30 with working length and then step-back until # 45 with K-Flexofile (Maillefer, Swiss). Group 2. Root canal preparation was done by Naviflex Ni-Ti file (Brasseler, USA) as the same technique with group 1. Group 3. Canal was prepared by Profile .04 (Maillefer, Swiss) taper until #30. Group 4. With use of Quantec (Tycom, USA) root canal was prepared from file number 1 to 8. In group 1 and 2, the root canal irrigant was NaOCl and the other groups, NaOCl and RC-prep (Premine Dental Products, USA) was used. The prepared teeth were notched with high-speed bur as bucco-lingual direction and fractured with chisel and mallet, then examined with SEM. Group 1 showed smooth internal surface. There were scratches mainly to the axial direction. Group 2 showed similar characteristics to those in group 1. Group 3 showed more smoother and linear cutting surface with bised scratches. Group 4 has the almost same characteristics group 3 and there was no difference in the file design. Ni-Ti rotary root canal instrument prepare the dentinal wall more smoother than hand instrument. The effectiveness of debridement was not fully affected by file design. The isthmus area and accessory canals of the root canal system were not prepared in any group. According to the result, hand and rotary type instrumentation techniques were effective in removal of major amount of tissue from root canal but it was not complete. In the direction of cutting movement there was difference between them.

• Korean Journal of Microbiology
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• v.55 no.3
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• pp.242-247
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• 2019

Biological factors (e.g. microorganism activity) in wastewater treatment plant (WWTP) play essential roles for degradation and/or removal of organic matters. In this study, to understand the microbial functional roles in WWTP, we tried to isolate and characterize a bacterial strain from activated sludge sample. Strain S16 was isolated from the activated sludge of a municipal WWTP in Daejeon metropolitan city, the Republic of Korea. The cells were a Gram-stain-positive, non-motile, facultative anaerobe, and rod-shaped. Strain S16 grew at a temperature of $15{\sim}40^{\circ}C$ (optimum, $30^{\circ}C$), with 0~9.0% (w/v) NaCl (optimum, 1.0~2.0%), and at pH 5.5~9.0 (optimum, pH 7.0~7.5). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain S16 was most closely related to the unique species Miniimonas arenae NBRC $106267^T$ (99.79%, 16S rRNA gene sequence similarity) of the genus Miniimonas. The cell wall contained alanine, glutamic acid, serine, and ornithine. Although the isolation source of the type strain NBRC $106267^T$ which considered as a marine microorganism is sea sand, that of strain S16 is terrestrial environment. It might raise an ecological question for habitat transition. Therefore, comparative genome analysis will be valuable investigation for shedding light on their potential metabolic traits and genomic streamlining.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.29 no.1
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• pp.131-141
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• 2011

This study, as a purpose of base study for landscape redevelopement of Seowon, pointed out problems of planting patterns in each sector and suggested an alternative through analyzing old literature, complete enumeration survey in each sector and taking aerial images. the conclusions drawn from this study are as follows. A Pilam Seowon(historic site no 242) is located in a Pyungya-Sanrok(plain and mountain) district in Jangsung-gun and has Junhak-Humyo(Study room in the front and Shirne in the back) type. 23 taxonomic group of arbor, 6 taxonomic group of shrub and 5 taxonomic group of flowers are planted high-densitily in limited flat surface. It can be classified into being planted by family and being planted through landscape redevelopement in 1980s. Korean traditional trees are planted in this area like Pinus densiflora, Juniperus chinensis L., Thuja orientalis L., Zelkova serrato Makino, Sophora japonica L., Lagerstroemia indica, Prunus mume include Ginkgo biloba which is old big tree and is registered in Jangsung-gun as protected trees. The tea tree in this area was introduced from wild tea plantation in Yonhwa moutain and was planted. From now on, we have to pay consideration a form management of planted trees in the historical area, rearrangement of plant density due to over planting, removal of alien trees like Pinus bungeana and Canna generalisa, prevention a dwarfishness of main area due to over planting in outside facilities, recovery a alienation among each planting area, and planting concept from plants drawings on wall of buildings can be suggested. The implications of this case study is that introduction of over planting can make more problems like losing sense of place. Therefore, we must do a actual state survey on traditional landscape area like Seowon from preservation point of view.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.6C
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• pp.385-393
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• 2006

Soil nailing is a reinforcement method used for stabilizing excavated walls or slopes. Due to its much advantages such as ease of construction and economical efficiency, use of soil nailing is increased. However, the soil nail has much disadvantages for use in urban area. The soil nail needs to be installed inevitably beyond private land boundary, which causes rent for use. For this reason, removable soil nailing system was developed. However, the removal rate of this system is just about 50￠¦70%. To resolve this problem, the Fiber Reinforced Plastic (FRP) soil nailing system which does not need to be removed and allows for the installation beyond private land, is developed. In this paper, through theoretical and experimental studies in laboratory and field such as prototype tests, pullout tests, we evaluate the stability and behavior characteristics of the FRP soil nailing system. And, numerical analyses using FLAC2D were performed with respect to various soil conditions, where prototype test for excavation wall and pullout tests were carried out. As a result of this study, the FRP soil nailing systems show similar behavior characteristics with those of removable soil nailing system. Finally, considering the serviceability and mechanical stability of FRP soil nailing systems, it is enough to be used as a good alternative of general soil nailing system.

• Journal of Korean Neurosurgical Society
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• v.30 no.9
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• pp.1079-1085
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• 2001

Objective : We analysed various surgical approaches and surgical results of 28 middle cranial base tumors for the purpose of selecting optimal surgical approach to the middle cranial base tumor. Methods : In this retrospective review, 28 patients, including 16 meningioma, 6 trigeminal neurinoma, 2 pituitary adenoma, 2 craniopharyngioma, 1 facial neurinoma, and 1 metastatic tumor, underwent surgical treatment using skull base technique. Of theses, 16 tumors were mainly confined to middle cranial fossae, 5 tumors with extension into both anterior and middle fossa, and 7 tumors with extension into both middle and posterior fossa. Tumors that confined to the middle cranial fossa or extended into the anterior cranial fossa were operated with modified pterional, orbitozygomatic or Dolen'c approach, and tumors that extended into the posterior cranial fossa were operated with anterior, posterior or combined transpetrosal approach. Completeness of tumor resection, surgical outcome, postoperative complication, and follow up result were studied. Results : Total tumor removal was achieved in 9 tumors of 10 tumors that did not extended to the cavernous sinus, and was achieved in 7 tumors of 8 tumors that extended to the lateral wall of the cavernous sinus. Of 10 tumors that extended to the venous channel of the cavernous sinus, only 2 were removed totally. Surgical outcome was excellent in 14 patients, good in 10, fair in 2 and poor in 2. There were no death in this series. Dumbell type tumor which extended into both middle and posterior fossae showed tendency of poor prognosis as compared with tumors that confined middle cranial fossa and extended into both anterior and middle cranial fossa. Postoperative dysfunctions were trieminal hypesthesia in 3, oculomotor nerve palsy in 2, abducens nerve palsy in 2, hemiparesis in 2, cerebellar sign in 1, facial palsy in 1 and hearing impairment in 1. Conclusion : Based on our findings and a review of the literature, we conclude that, when selecting the surgical approach to the middle cranial fossa tumors, the most important factors to be considered were exact location of the tumor mass and existence of the cavernous sinus invasion by tumor mass. We recommend modified pterional or orbitozygomatic approach in cases with tumors located anterior and middle cranial base, without cavernous sinus invasion. In cases with tumors invading into cavernous sinus, we recommend Dolen'c or orbitozygomatic approach. And in lateral wall mass and the cavernous sinus, it is preferred to approach the tumor extradurally. For the tumor involing with middle fossa and posterior fossa(dumbell type) a combined petrosal approach is necessary. In cases with cavernous sinus invasion and internal carotid artery encasement, we recommend subtotal resection of the tumor and radiation therapy to prevent permanent postoperative sequele.

• Restorative Dentistry and Endodontics
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• v.31 no.4
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• pp.323-329
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• 2006

The aim of this study was to evaluate the retrievability of Resilon as a root canal filling material Twenty-seven human single-rooted extracted teeth were instrumented utilizing a crown down technique with Gates-Glidden burs and ProFile system. In group1 (n = 12) canals were obturated with gutta percha and AH-26 plus sealer using a continuous wave technique and backfilled. In group 2 (n = 15) Resilon was used as a filling material. Then teeth were sealed and kept in $37^{\circ}C$ and 100% humidity for 7 days. For retreatment, the samples were re-accessed and filling material was removed using Gates-Glidden burs and ProFiles. Teeth were sectioned longitudinally to compare the general cleanliness and amount of debris $({\times}\;75)$ using SEM. Chi-square test was used $({\alpha}\;=\;0.05)$ to analyze the data. The total time required for removal of filling materials was expressed as mean ${\pm}SD$ (min) and analyzed by the Student t-test $({\alpha}\;=\;0.05)$, Required time for retreatment was $3.25\;{\pm}\;0.32$ minutes for gutta percha/ AH 26 plus sealer and $3.05\;{\pm}\;0.34$ minutes for Resilon. There was no statistically significant difference between the two experimental groups. There was no significant difference between the groups in the cleanliness of the root canal wall. This study showed that Resilon was effectively removed by Gates-Glidden burs and ProFiles.