• Clean Technology
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• v.18 no.3
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• pp.280-286
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• 2012

The dry etching of sacrificial $SiO_2$ was performed in supercritical carbon dioxide. The etching of boron phosphor silica glass (BPSG), tetraethyl orthosilicate (TEOS), thermal $SiO_2$, and Si-nitride (SiN) was investigated by using a two chamber system with HF/py etchant and alcohol additives. The etch rate of sacrificial $SiO_2$ increased upon the addition of methanol. The etch selectivity of BPSG with respect to SiN was highest with IPA although the highest etch rate was resulted from methanol except BPSG. The etch rate increased with the temperature in HF/py/MeOH system. Especially the increase of the etch rate was much higher for BPSG with an increase in the reaction temperature. The etch residue was not reduced apparently upon the addition of alcohol cosolvents to HF/py. While the etch rate in HF/$H_2O$ was higher than HF/py/alcohol system, the rate decreased with the addition of alcohols to HF/$H_2O$. The cantilever beam structure of high aspect ratios was released by the dry ething in supercritical carbon dioxide without damage.

• The Journal of Dong Guk Oriental Medicine
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• v.7 no.1
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• pp.65-74
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• 1998

We investigated the in vivo effect of an aquous extract from Rhois Galla (R-G) on glucokinase and hexokinase activities of diabetes mellitus induced by interleukin-$1{\beta}$ ($IL-1{\beta}$). After 1 week of alloxan injection, the levels of serum glucose and insulin secretion were dramatically increased, however, the insulin secretion was decreased with administration of R-G. $IL-1{\beta}$ injection allowed the serum glucose level increased and the level was decreased by R-G administration. Furthermore, we could observe that R-G was effective in recovering the levels of insulin secretion. Enzyme activities of the glucokinase and hexokinase were decreased by $IL-1{\beta}$ treatment In contrast, R-G administration to the mice allowed proportion increasing. Seemingly, when $IL-1{\beta}$ was injected to the mice, enzyme activities of the glucokinase and hexokinase were decreased. But, R-G stimulated induction of enzyme activities of the glucokinase and hexokinase as high as normal group. These results suggested that R-G is highly effective in treatment of diabetes mellitus.

• The Journal of Dong Guk Oriental Medicine
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• v.7 no.1
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• pp.119-133
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• 1998

This study was performed to investigated the effects of an immunosuppression and a mitigation of inflammation of Scutellaria baicalensis GEORGI on Allergic contact dermatitis. In order to study, after oral administration of Scutellaria baicalensis GEORGI extract, contact hypersensitivity assay, general morphologic change of skin, sulfated acid mucosubstance, mast cell, IL-2R, ICAM-1 and CD11b were observed in BALB/C mouse induced allergic contact dermatitis by the contact sensitizing DNCB. Ear swelling in contact hypersensitivity assay was decreased in the Scutellaria baicalensis GEORGI extracts administered(HEGT) group, compared with DNCB painted group. In the general morphologic change of skin, hyperplasia of keratinocytes, increase of lymphocytes and inflammatory cell, increase of vasculogenesis and epidermal lymphocytes infiltration, increase of cell damage in epidermal basal layer and prickle layer were decreased in the HEGT group, compared with DNCB painted group. Increase of sulfated acid mucosubstance, mast cell, IL-2R positive cell, ICAM-1 positive cell, CD11b positive cell were decreased in the HEGT group, compared with DNCB painted group.

• Korean Journal of Materials Research
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• v.9 no.10
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• pp.1018-1024
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• 1999

The effects of operating temperature and stress on degradation of components in high temperature steam generator were investigated. Several 2.25CrlMo tubes which had operated over 20 years and an unused 9CrlMoVNb tube were tested. For the former samples, the amount of $\textrm{M}_{6}\textrm{C}$ carbide and its size are increased with the aging or operating time. The precipitation behavior of carbides ($\textrm{M}_{2}\textrm{O}$, $\textrm{M}_{6}\textrm{C}$) is changed with the operating temperature of the tubes. However, unused 9CrlMoVNb samples show a different carbide precipitation process due to high chromium, vanadium, and niobium contents. The amount of Cr-rich $\textrm{M}_{23}\textrm{C}_{6}$ carbide is significantly increased with aging time, but that of $\textrm{M}_{6}\textrm{C}$ type carbide is rarely changed with aging time at elevated temperatures.

• Journal of Veterinary Clinics
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• v.30 no.3
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• pp.159-165
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• 2013

The present study was conducted to evaluate the efficacy of Cinnamomum cassia Blume (CC) extract on the repair of damaged cartilage in a rat model of osteoarthritis (OA) by anterior cruciate ligament transection (ACLT) and medial meniscus resection (MMx). Forty-eight rats were assigned to six groups (n = 8 per group): sham as negative control (NC), positive control (PC), diclofenac sodium (DS, 2 mg/kg), CC 25 mg/kg, CC 50 mg/kg and CC 100 mg/kg groups. Treatments were 12 weeks from 7 days after ACLT + MMx. Loss of cartilage and joint instability were significantly reduced in response to treatment with CC or DS compared to the PC (p < 0.05). CC significantly ameliorated cartilage degradation in a dose-dependent manner as assessed by histological findings (p < 0.01). A reduction in the severity of structural changes and a dose-dependent increase in Safranin-O staining intensity were observed in CC treatments, indicating that cartilage degradation was inhibited. Although DS did not affect the increase in active caspase-3 and cleaved poly(ADP-ribose) polymerase-induced apoptosis during the progression of OA, cells reactive to these apoptotic markers were decreased significantly by CC (p < 0.05). However, treatments with CC or DS did not influence the uptake of 5-bromo-2'-deoxyuridine. The findings suggest that CC can exert a chondroprotective action on OA through anti-inflammatory and anti-apoptotic properties.

• Korean Journal of Microbiology
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• v.46 no.3
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• pp.270-277
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• 2010

In order to manufacture Bacillus cereus-free fermented soybean products, an antimicrobial agentproducing isolate against B. cereus was obtained from 150 traditionally fermented soybean products. The morphological and biochemical tests and the phylogenetic relationship among 16S rRNA gene sequences indicated that the isolate named as the strain SCK 121057 was most closely related to Bacillus licheniformis. The B. licheniformis isolate began to produce the antimicrobial agent after 48 h of incubation. The agent was nonproteinaceous and insensitive to heat, long term storage and protease K. Electron microscopic observation indicated that the agent attacked the membrane of B. cereus, leaving the ghost cell. The isolate inhibited growth of B. subtilis, Lactobacillus brevis and various types of pathogenic strains including Escherichia coli, E. faecalis, Micrococcus luteus, Staphylococcus aureus, Aspergillus flavus, A. ochraceus, and A. parasiticus as well as B. cereus. After coinoculation of B. licheniformis SCK 121057 and B. cereus in the ratio (as the basis of CFU/g sample) of 10 to 1 on the surface of cooked soybeans, cell numbers of B. cereus had been dramatically reduced after 31 days of incubation compared to those of single inoculation of B. cereus.

• Journal of Conservation Science
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• v.32 no.4
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• pp.521-534
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• 2016

Ancient tombs are typically comprised of confined rooms, which have different spatial characteristics than the external environment because they are covered by heavy layers of soil. In this study, we examined the thermal energy flow from the outside to inside of Songsan-ri tomb No. 6. External heat flows slowly to the inside because of heavy soil layer, and the presence of several rooms and entrances. For this reason, it takes about two months for the air temperature to travel from the outside to the inside of the tomb. Interestingly, the gradational inflow of thermal energy from outside the tomb leads to delicate horizontal and vertical variations in the wall temperature. These micro-environmental differences occur in the inner tomb every year, so we can expect them to cause condensation with regularity. In addition, we show that the previously installed forced circulation air conditioning system risks fatal damage to the mural wall painting. The results of this research suggest an optimal air conditioning system and optimized space planning to conserve Songsan-ri tomb No. 6 and its mural painting.

• Journal of the Korea Concrete Institute
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• v.24 no.3
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• pp.249-258
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• 2012

Integral and rigid frame bridges have advantages in bridge maintenance and structural efficiency by eliminating expansion joints and bridge supports. However, the detail of typical girder-abutment connection is rather complex and increases construction cost depending on construction detail. For the purpose of compensating disadvantages such as complexity and additional cost, a new type of bridge is proposed in this study, which improves the efficiency of construction by simplifying the construction detail of girder-abutment connection. The proposed bridge has the connection detail of steel girder and abutment integrated by prestressed PS bar installed in the connection. In this study, finite element analysis and fatigue load test are conducted to evaluate the fatigue capacity of the proposed girder-abutment connection. The results of the finite element analysis revealed that the possibility of the fatigue damage in the girder-abutment connection is very low. The results of the fatigue load test verified that the integrity of the girder and abutment connection is maintained after 2,000,000 cycles of fatigue loading.

• Journal of the Korea Concrete Institute
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• v.23 no.1
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• pp.109-120
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• 2011

This paper presents an experimental study results on the crack control of flexure-dominant reinforced concrete beams repaired with strain-hardening cement composite (SHCC). Five RC beams were fabricated and tested until failure. One unrepaired RC beam was a control specimen (CBN) and remaining four speciemens were repaired with SHCC materials. The test parameters included two types of SHCC matrix ductility and two types of repair method (patching and layering). Test results demonstrated that RC beams repaired with SHCC showed no concrete crushing or spalling until final failure, but numerous hair cracks were observed. The control specimen CBN failed due to crushing. It is important to note that SHCC matrix can improve crack-damage mitigation and flexural behavior of RC beams such as flexural strength, post peak ductility, and energy dissipation capacity. In the perspective of crack width, crack widths in RC beams repaired with SHCC had far smaller crack width than the control specimen CBN under the same deflection. Especially, the specimens repaired with SHCC of PVA0.75%+PE0.75% showed a high durability and ductility. The crack width indicates the residual capacity of the beam since SHCC matrix can delay residual capacity degradation of the RC beams.

• Journal of the Korea Concrete Institute
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• v.22 no.2
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• pp.219-228
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• 2010

It has been well known that concrete structures exposed to acid and sulfate environments such as sewer, sewage and wastewater, soil, groundwater, and seawater etc. show significant decrease in their durability due to chemical attack. Such deleterious acid and sulfate attacks lead to expansion and cracking in concrete, and thus, eventually result in damage to concrete matrix by forming expansive hydration products due to the reaction between portland cement hydration products and acid and sulfate ions. Objectives of this experimental research are to investigate the effect of mineral admixtures on the resistance to acid and sulfate attack in concrete and to suggest high-resistance concrete mix against acid and sulfate attack. For this purpose, concretes specimens with three types of cement (ordinary portland cement (OPC), binary blended cement (BBC), and ternary blended cement (TBC) composed of different types and proportions of admixtures) were prepared at water-biner ratios of 32% and 43%. The concrete specimens were immersed in fresh water, 5% sulfuric acid, 10% sodium sulfate, and 10% magnesium sulfate solutions for 28, 56, 91, 182, and 365 days, respectively. To evaluate the resistance to acid and sulfate for concrete specimens, visual appearance changes were observed and compressive strength ratios and mass change ratios were measured. It was observed from the test results that the resistance against sulfuric acid and sodium sulfate solutions of the concretes containing mineral admixtures were much better than that of OPC concrete, but in the case of magnesium sulfate solution the concretes containing mineral admixtures was less resistant than OPC concrete due to formation of magnesium silicate hydrate (M-S-H) which is non-cementitious.