• Proceedings of the Korea Association of Crystal Growth Conference
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• 1996.06a
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• pp.179-200
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• 1996

The intrinsic instabilities of fluid flow occurred in the melt of the Czochralski crystal growth system Czochralski method, asymmetric flow patterns and temperature profiles in the melt have been studied by many researchers. The idea that the non-symmetric structure of the growing equipment is responsible for the asymmetric profiles is usually accepted at the first time. However further researches revealed that some intrinsic instabilities not related to the non-symmetric equipment structure in the melt could also appear. Ristorcelli had pointed out that there are many possible causes of instabilities in the melt. The instabilities appears because of the coupling effects of fluid flow and temperature profiles in the melt. Among the instabilities, the B nard type instabilities with no or low crucible rotation rates are analyzed by the visualizing experiments using X-ray radiography and the 3-D numerical simulation in this study. The velocity profiles in the Silicon melt at different crucible rotation rates were measured using X-ray radiography method using tungsten tracers in the melt. The results showed that there exits two types of fluid flow mode. One is axisymmetric flow, the other is asymmetric flow. In the axisymmetric flow, the trajectory of the tracers show torus pattern. However, more exact measurement of the axisymmetrc case shows that this flow field has small non-axisymmetric components of the velocity. When fluid flow is asymmetric, the tracers show random motion from the fixed view point. On the other hand, when the observer rotates to the same velocity of the crucible, the trajectory of the tracer show a rotating motion, the center of the motion is not same the center of the melt. The temperature of a point in the melt were measured using thermocouples with different rotating rates. Measured temperatures oscillated. Such kind of oscillations are also measured by the other researchers. The behavior of temperature oscillations were quite different between at low rotations and at high rotations. Above experimental results means that the fluid flow and temperature profiles in the melt is not symmetric, and then the mode of the asymmetric is changed when rotation rates are changed. To compare with these experimental results, the fluid flow and temperature profiles at no rotation and 8 rpm of crucible rotation rates on the same size of crucible is calculated using a 3-dimensional numerical simulation. A finite different method is adopted for this simulation. 50×30×30 grids are used. The numerical simulation also showed that the velocity and flow profiles are changed when rotation rates change. Futhermore, the flow patterns and temperature profiles of both cases are not axisymmetric even though axisymmetric boundary conditions are used. Several cells appear at no rotation. The cells are formed by the unstable vertical temperature profiles (upper region is colder than lower part) beneath the free surface of the melt. When the temperature profile is combined with density difference (Rayleigh-B nard instability) or surface tension difference (Marangoni-B nard instability) on temperature, cell structures are naturally formed. Both sources of instabilities are coupled to the cell structures in the melt of the Czochralski process. With high rotation rates, the shape of the fluid field is changed to another type of asymmetric profile. Because of the velocity profile, isothermal lines on the plane vertical to the centerline change to elliptic. When the velocity profiles are plotted at the rotating view point, two vortices appear at the both sides of centerline. These vortices seem to be the main reason of the tracer behavior shown in the asymmetric velocity experiment. This profile is quite similar to the profiles created by the baroclinic instability on the rotating annulus. The temperature profiles obtained from the numerical calculations and Fourier transforms of it are quite similar to the results of the experiment. bove esults intend that at least two types of intrinsic instabilities can occur in the melt of Czochralski growing systems. Because the instabilities cause temperature fluctuations in the melt and near the crystal-melt interface, some defects may be generated by them. When the crucible size becomes large, the intensity of the instabilities should increase. Therefore, to produce large single crystals with good quality, the behavior of the intrinsic instabilities in the melt as well as the effects of the instabilities on the defects in the ingot should be studied. As one of the cause of the defects in the large diameter Silicon single crystal grown by the

• Journal of Dental Rehabilitation and Applied Science
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• v.25 no.3
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• pp.225-235
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• 2009

A common procedure of restoration of endodonticlly treated tooth with fiber-reinforced post is followed by core build-up after post cementation. However, this technique is complex and time-consuming. The aim of this study was to compare fracture strength of premolar, restored with various methods of core fabrications on fiber-reinforced posts and casting metal restoration. Forty five freshly extracted human mandibular premolars were obtained and devided into 5 groups acconding to the type of post and methods of core build-up. In Group A, D.T. $Light-post^{(R)}$ were cemented with $DUO-LINK^{TM}$ and then $LIGHT-CORE^{TM}$ was used for core restoration. In Group B, D.T. $Light-post^{(R)}$ and $DUO-LINK^{TM}$ were used for cementing in the postspace, and $DUO-LINK^{TM}$ was used again for core restoration. In Group C, $Light-post^{(R)}$ bonding and the core build-up were performed simultaneously by using $DUO-LINK^{TM}$. In Group D, $LuxaPost^{(R)}$ was bonded by using $LuxaCore^{(R)}-Dual$. Again, $LuxaCore^{(R)}-Dual$ was used for core restoration. In Group E, $LuxaPost^{(R)}$ bonding and the core build-up were performed simultaneously by using $LuxaCore^{(R)}-Dual$. Axial reduction was formed parallelly as possible and 45 degree bevel was made at buccal occlusal surface. Crowns were fabricated and cemented. Each tooth was embedded in self-curing acrylic resin to the level of 2mm below the CEJ. Specimens were fixed on universal testing machin such that the axis of the tooth was at 45 degree inclination to the horizontal plane, and compressive force was applied at a crosshead speed of 1mm/min until failure occurred. The mean fracture strength was the highest in group A followed by descending order in group B, D, E and C. However, there were no statistically significant differences between groups with regard to the fracture strength. The type of the post or build-up methods of the core does not seem to influence the fracture strength.

• Tuberculosis and Respiratory Diseases
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• v.58 no.5
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• pp.480-489
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• 2005

Background : Dysregulation of apoptosis plays an important role in carcinogenesis, tumor progression, and resistance to chemotherapy. X-linked inhibitor of apoptosis (XIAP) is considered to be the most potent caspase inhibitor of all known IAP (inhibitor of apoptosis) family members. This study was designed to assess the pattern of expression and the prognostic value of XIAP in radically resected non-small cell lung carcinoma (NSCLC) patients. Method : The expression of XIAP and its relationship with clinicopathologic parameters (patient age, TNM stage, TNM-pT, TNM-pN, histologic type, VEGF expression, microvessel density, PCNA index) and overall survival were analysed with formalin-fixed, paraffin-embedded blocks from eighty cases of NSCLC. In addition, the apoptotic index (AI) was also assessed. Results : In a regard to histologic type, squamous cell carcinoma (SCC) showed XIAP expression in 91.3%(42/46) and adenocarcinoma (AC) in 61.8%(21/34). The difference was significant(p=0.001). There was no correlation between XIAP expression and other parameters. In the group of AC, XIAP expression showed the signifcant correlation with older age group ${\geq}58years$ and VEGF expression(p=0.028, p=0.014, respectively). The AI in the group with or without XIAP expression were $2.5{\pm}4.9%$ and $18.5{\pm}28.9%$, respectively(p=0.001). Both groups just aforementioned showed no significant difference in median survival time (42.5 months, 29.8 months, respectively). Conclusion : This study suggests that the XIAP expression in NSCLCs could have relation to inhibition of apoptosis, and show differential expression according to histologic type. However, its prognostic role during the progression of NSCLC needs to be further defined.

• Journal of Periodontal and Implant Science
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• v.26 no.1
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• pp.1-26
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• 1996

This study was performed to estimate the effects of cultured bone cell inoculated on porous type hydroxyaptite for the regeneration of the artificial alveolar bone defect. In this experiment 3 beagle dogs were used, and each of them were divided into right and left mandible. Every surgical intervention were performed under the general anesthesia by using with intravenous injection of Pentobarbital sodium(30mg/Kg). To reduce the gingival bleeding during surgery, operative site was injected with Lidocaine hydrochloride(l:80,000 Epinephrine) as local anesthesia. After surgery experimental animal were feeded with soft dietl Mighty dog, Frisies Co., U.S.A.) for 1 weeks to avoid irritaion to soft tissue by food. 2 months before surgery both side of mandibular 1st premolar were extracted and bone chips from mandibular body were obtained from all animals. Bone cells were cultured from bone chips obtained from mandible with Dulbecco's Modified Essential Medium contained with 10% Fetal Bovine Serum under the conventional conditions. Porous type hydroxyapatite were immerse into the high concentrated cell suspension solution, and put 4 hours for attachin the cells on the surface of hydroxyapatite. Graft material were inserted on the artificial bone defect after 3 days of culture. Before insertion of cellinoculated graft material, scanning electronic microscopic observation were performed to confirm the attachment and spreading of cell on the hydroxyapatite surface. 3 artificial bone defects were made with bone trephine drill on the both side of mandible of the experimental animal. First defect was designed without insertion of graft material as negative control, second was filled with porous replamineform hydroxyapatite inoculated with cultured bone marrow cells as expermiental site, and third was filled with graft materials only as positive control. The size of every artificial bone defect was 3mm in diameter and 3mm in depth. After the every surgical intervention of animals, oral hygiene program were performed with 1.0% chlorhexidine digluconate. All of the animals were sacrificed at 2, 4, 6 weeks after surgery. For obtaining histological section, tissus were fixed in 10% Buffered formalin and decalcified with Planko - Rycho Solution for 72hr. Tissue embeding was performed in paraffin and cut parallel to the surface of mandibular body. Section in 8um thickness of tissue was done and stained with Hematoxylin - Eosin. All the specimens were observed under the light microscopy. The following results were obtained : 1. In the case of control site which has no graft material, less inflammatory cell infiltration and rapid new bone forming tendency were revealed compared with experimental groups. But bone surface were observed depression pattern on defect area because of soft tissue invasion into the artificial bone defect during the experimental period. 2. In the porous hydroxyapatite only group, inflammatory cell infiltration was prominet and dense connective tissue were encapsulated around grafted materials. osteoblastic activity in the early stage after surgery was low to compared with grafted with bone cells. 3. In the case of porous hydroxyapatite inoculated with bone cell, less inflammatory cell infiltration and rapid new bone formation activity was revealed than hydroxyapatite only group. Active new bone formation were observed in the early stage of control group. 4. The origin of new bone forming was revealed not from the center of defected area but from the surface of preexisting bony wall on every specimen. 5. In this experiment, osteoclastic cell was not found around grafted materials, and fibrovascular invasion into regions with no noticeable foreign body reaction. Conclusively, the cultured bone cell inoculated onto the porous hydroxyapatite may have an important role of regeneration of artificial bone defects of alveolar bone.

• Journal of the Korean Geographical Society
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• v.28 no.1
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• pp.1-15
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• 1993

This research aims to investigate some respects of chemical weathering processes, espcially the amount of solute leaching, formation of clay minerals, and the chemical weathering rate of granite rocks under present climatic conditions. For this purpose, I investigated geochemical mass balance in a small catchment and the mineralogical composition of weathered bedrocks including clay mineral assemblages at four res-pective sites along one slope. The geochemical mass blance for major elements of rock forming minerals was calculated from precipitation and streamwater data which are measured every week for one year. The study area is a climatically and litholo-gically homogeneous small catchment($3.62Km^2$)in Anyang-shi, Kyounggi-do, Korea. The be-drock of this area id Anyang Granite which is composed of coarse-giained, pink-colored miner-als. Main rock forming minerals are quartz, K-Feldspar, albite, and muscovite. One of the chracteristics of this granite rock is that its amount of Ca and Mg is much lower than other granite rock. The leaching pattern in the weathering profiles is in close reltion to the geochemical mass balance. Therefore the removal or accumulation of dissolved materials shows weathering patterns of granite in the Korean peninsula. Oversupplied ions into the drainage basin were $H^+$, $K^+$, Fe, and Mn, whereas $Na^2+$, $Mg^2+$, $Ca^2+$, Si, Al and $HCO-3^{-}$ were removed from the basin by the stream. The consumption of hydrogen ion in the catchment implies the hydrolysis of minerals. The surplus of $K^+$ reflects that vegetation is in the aggravation stage, and the nutrient cycle of the forest in study area did not reach a stable state. And it can be also presumed that the accumulation of $K^+$ in the top soil is related to the surplus of $K^+$. Oversupplied Fe and Mn were presumed to accumulate in soil by forming metallic oxide and hydroxide. In the opposite, the removal of $Na^+$, Si, Al resulted from the chemical weathering of albite and biotite, and the amount of removal of $Na^+$, Si, Al reflected the weathering rate of the bedrock. But $Ca^2+$ and $Mg^2+$ in stream water were contaminated by the scattered calcareous structures over the surface. Kaolinite is a stable clay mineral under the present environment by the thermodynamical analysis of the hydrogeochemical data and Tardy's Re value. But this result was quite different from the real assemblage of clay miner-als in soil and weathered bedrock. This differ-ence can be explained by the microenvironment in the weathering profile and the seasonal variation of climatic factors. There are different clay forming environments in the stydy area and these differences originate from the seasonal variation of climate, especially the flushing rate in the weathering profile. As it can be known from the results of the analysis of thermodynamic stability and characteristics of geochemical mas balance, the climate during winter and fall, when it is characterized by the low flushing rate and high solute influx, shows the environmental characteristics to from 2:1 clay minerals, such as illite, smectite, vermiculite and mixed layer clay minerals which are formed by neoformation or transformation from the primary or secondary minerals. During the summer and spring periods, kaoli-nite is a stable forming mineral. However it should consider that the other clay minerals can transformed into kaolinite or other clay minerals, because these periods have a high flushing rte and temperature. Materials which are directly regulated by chemical weathering in the weathered bedrock are $Na^+$, Si, and Al. The leaching of Al is, however, highly restricted and used to form a clay mineral, and that of Si falls under the same category. $Na^+$ is not taked up by growing veget ation, and fixed in the weathering profile by forming secondary minerals. Therefore the budget of $Na^+$ is a good indicator for the chemical weathering rate in the study area. The amount of chemical weathering of granite rocks was about 31.31g/$m^2+$/year based on $Na^+$ estimation.

• Journal of Animal Science and Technology
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• v.49 no.6
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• pp.711-718
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• 2007

Most cattle breeds have a coat color pattern that is characteristic for the breed. Korean cattle(Hanwoo) has a coat color ranging from yellowish brown to dark brown including a red coat color. Variation in the Hanwoo coat color is likely to be the effects of modified genes segregating within the Hanwoo breed. MC1R encoded by the Extension(E) locus was almost fixed with recessive red e allele in the Hanwoo, but other gene(s) might be affecting the variation of the Hanwoo coat color into yellowish to red brown. We have analyzed a segregation of coat color in the F2 families generated from two Hanwoo bulls(yellowish brown) mated to six F1 dams(black) derived from Hanwoo and Holstein crosses. Segregation of coat color in the offspring found a ratio of 1(yellowish brown) : 1(black) and this ratio indicates that a single gene may play a major role for the Hanwoo coat color. We further investigated SNPs in MC1R, ASIP and TYRP1 loci to determine genetic cause of the Hanwoo coat color. Several polymorphisms within ASIP intron 2 and TYRP1 exons were found but not conserved within the Hanwoo population. However, the segregation of the MC1R e allele was completely associated with the Hanwoo coat color. Based on this information, it is clear that the MC1R e allele is mainly responsible for the yellowish red Hanwoo coat color. Further study is warrant to identify possible genetic interaction between MC1R e allele and other coat color related gene(s) for the variation of Hanwoo coat color from yellowish brown to dark brown. (Key words : Hanwoo, Coat color, SNP, MC1R, ASIP, TYRP1)

• Journal of Life Science
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• v.26 no.9
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• pp.1056-1062
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• 2016

Lung cancer is currently the most common malignant disease and the leading cause of mortality in the world and non-small cell lung cancer (NSCLC) accounts for 75-80% of lung cancer cases. miR-155 gene was found to be over expressed in several solid tumors, such as thyroid carcinoma, breast cancer, colon cancer, cervical cancer, pancreatic ductal adenocarcinoma (PDAC) and lung cancer. The aims of this study were to define the expression of miR-155 in lung cancer and its associated clinic-pathologic characteristics. Total RNA was purified from formalin-fixed, paraffin-embedded NSCLC tissues and benign lung tissues. Expression of miR-155 in human lung cancer tissues were evaluated as mean fold changes of miR-155 in cancer tissues compared to benign lung tissues by quantitative real-time reverse transcriptase polymerase chain reaction (real-time qRT-PCR) and associations of miR-155 expression with clinic-pathologic findings of cancer. Compared with the benign control group, miR-155 expression was significantly overexpressed in NSCLCs (p=<0.001). miR-155 was more overexpressed in squamous cell carcinoma than in adenocarcinoma. Poorly differentiated tumors showed significantly overexpression of miR-155 than well-differentiated tumors (p=<0.001). Overexpression of miR-155 was significantly associated with lymph node metastasis (p=<0.05). In survival analysis for all NSCLC patients, high miR-155 expression was significantly correlated with worse overall survival (p=<0.05). These results suggested that miR-155 might play an important role in lung cancer progression and metastasis.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.4
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• pp.733-742
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• 2000

Fundamental materialistic characterization and adsorption/neutralization behavior of waste egg shell for heavy metal ion have been studied for its application to wastewater treatment. To investigate the structural change and thermal decomposition characteristics of egg shell. X-ray diffraction and FT-IR analysis were conducted for egg shell treated at $105^{\circ}C$ and $700^{\circ}C$, respectively. For the result of FT-IR analysis, the sample treated at $700^{\circ}C$ showed a reduced C-O absorption band compared with that of egg shell treated at $105^{\circ}C$, which may be due to the $CO_2$ release. Unlike to the result of FT-IR analysis, the XRD patterns of egg shell were almost similar for the cases of $105^{\circ}C$ and $700^{\circ}C$ treatment. however, characteristic diffraction pattern of CaO was observed for $850^{\circ}C$ treatment, at which $CaCO_3$ is known to be completely converted to CaO. TGA/DTA analysis showed a slow decline in weight loss up to $600^{\circ}C$ and, for $600{\sim}800^{\circ}C$ range, the weight loss became drastic by reason of $CO_2$ discharge, which was accompanied by an appearance of major endothermic peak. The ratio of practical breakthrough time to ideal one, total transfer unit, and mass transfer coefficient were observed to be increased as the adsorption was progressed in a multiple-column fixed-bed reactor using egg shell as an adsorbent, which signified the distribution effect of mass transfer for continuous adsorption reaction. The neutralization effect of egg shell for several types of acidic wastewater made of different mineral acids was not much different from each other except for the case of $H_2SO_4$, for which the neutralization reaction was thought to be retarded by the formation of gypsum.

• Journal of the Korean Arthroscopy Society
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• v.8 no.2
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• pp.119-123
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• 2004

Purpose: The purpose of this study is to check the range of motion of shoulder and inverstigate the frequencies and patterns of partial thickness rotator cuff tear in SLAP lesions. Materials and Methods: Forty-six patients, forty-seven cases who had SLAP lesions at shoulder arthroscopy were analyzed spectively using the medical records, intra-operative arthroscopic photo & video for SLAP lesions and rotator cuff articular side partial tear. Under the interscalene anesthesia, the range of notion of foreward elevation, internal rotation and external rotation was measured on fixed scapula and 90 degree abduction of the shoulder. Results: The rang of Motion are 150 degree on foreward elevation, 65.5 degree on external rotation, 61.7 degree on internal rotation. By Snyder's classification, type ll SLAP lesion is noted in 24 cases (five cases in type 1, one case in type IV). Rotator cuff articular side partial tear is noted in 24 cases ( one case in type I, 22 cases in type II, one case in type IV SLAP). All the rotator cuff articular side partial thickness tear were located in the anterior part of the supraspinatus. Conclusion: The rotator cuff partial thickness tear is mostly noted on the articular side and frequently found in the relatively more unstable type of SLAP lesions. So we consider that SLAP lesion may be a one of the causes for partial tear of the rotator cuff articular side.

• Ecology and Resilient Infrastructure
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• v.8 no.4
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• pp.223-232
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• 2021

In general, stormwater flows to the road surface, especially in urban areas, and it is discharged through the drainage grate inlets on roads. The appropriate evaluation of the road drainage capacity is essential not only in the design of roads and inlets but also in the design of sewer systems. However, the method of road surface flow analysis that reflects the topographical and hydraulic conditions might not be fully developed. Therefore, the enhanced method of road surface flow analysis should be presented by investigating the existing analysis method such as the flow analysis module (uniform; varied) and the flow travel time (critical; fixed). In this study, the algorithm based on varied and uniform flow analysis was developed to analyze the flow pattern of road surface. The numerical analysis applied the uniform and varied flow analysis module and travel time as parameters were conducted to estimate the characteristics of rainfall-runoff in various road conditions using the developed algorithm. The width of the road (two-lane (6 m)) and the slope of the road (longitudinal slope of road 1 - 10%, transverse slope of road 2%, and transverse slope of gutter 2 - 10%) was considered. In addition, the flow of the road surface is collected from the gutter along the road slope and drained through the gutter in the downstream part, and the width of the gutter was selected to be 0.5 m. The simulation results were revealed that the runoff characteristics were affected by the road slope conditions, and it was found that the varied flow analysis module adequately reflected the gutter flow which is changed along the downstream caused by collecting of road surface flow at the gutter. The varied flow analysis module simulated 11.80% longer flow travel time on average (max. 23.66%) and 4.73% larger total road surface discharge on average (max. 9.50%) than the uniform flow analysis module. In order to accurately estimate the amount of runoff from the road, it was appropriate to perform flow analysis by applying the critical duration and the varied flow analysis module. The developed algorithm was expected to be able to be used in the design of road drainage because it was accurately simulated the runoff characteristics on the road surface.