• Environmental Analysis Health and Toxicology
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• v.3 no.1_2
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• pp.33-42
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• 1988

Dose-dependent, immune modulatory effects of aconitine and heated aconitine were studied in mice. Mice, administered aconitine and heated aconitine intraperitoneally every other day for 4 weeks, were sensitized and challenged with sheep red blood cells. Serum antibody titer, foot pad swelling and rosette forming cell number were measured to evaluate hurmoral and cell mediated immune responses. The results show that Humoral immune response was suppressed by aconitine 0.05 mg/kg and heated aconitine but increased by aconitine 0.10 mg/kg administration. Cell mediated immune response was suppressed in all groups. Especially heated aconitine administration significantly suppressed the cell mediated immune response. The number of peripheral circulating white blood cell was reduced by aconitine but was not affected by heated aconitine.

• Transactions of the Korean Society of Automotive Engineers
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• v.15 no.2
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• pp.126-134
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• 2007

Although there has been substantial research on the squeal noise for the automotive brake system, robust design issues with respect to control factors equivalent to design variables in optimization, noise factors due to system uncertainties, and signal factors designed to accommodate a user-adjustable setting still need to be addressed. For the purpose, the robust design applied to the disk brake system has been investigated by DOE (Design of Experiments) based Taguchi analysis with dynamic characteristics. The specific goal of this methodology is to identify a design with linear signal-response relationship, and variability minimization. The finite element models of the disk brake assembly have been constructed, and the squeal noise problems have been solved by complex eigenvalue analysis. As the practical robust design to reduce the brake squeal noise, material properties of pad, disk, and backplate, thickness and geometry of pad are selected as control factors, material properties of pad and disk, and the contact stiffness have been considered as noise factors, and friction coefficient between pad and disk is chosen as a signal factor. Through the DOE based robust design, the signal-to-noise ratio and the sensitivity for each orthogonal array experiment have been analyzed. Also, it has been proved that the proposed robust design is effective and adequate to reduce the brake squeal noise.

• KEPCO Journal on Electric Power and Energy
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• v.1 no.1
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• pp.79-84
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• 2015

Transformer is widely used element on power system and industrial area. Especially the transformers installed at power system are exposed to an environment of arbitrary changed. Thus the prediction of degradation and the analysis of response to impulse are important. To conduct those works, the electrical characteristics of system should be analyzed, effectively. But the analysis of electrical characteristic in electric machine level such as pole and pad-mounted transformer is almost no, thus commercial VNA (Vector Network Analyzer) is used to getting the response in wide frequency range. However, the output power of VNA is usually under 10mW, so verification for effectiveness of measuring electrically large component should be conducted, firstly. Next, after getting total S-parameter of transformer, predicting impulse response can be performed in time-domain with circuit simulator. In this paper, it is introduced that verification effectiveness of VNA using transfer function from SFRA (Sweep Frequency Response Analyzer), firstly. Next, total S-parameter, six by six matix form, was built using measured 2 port S-parameter from vector network analyzer. To get the response to impulse which is defined by IEC 60060-1, time-domain simulation is conducted to ADS (Advenced Design System) circuit simulator.

• The Journal of Internal Korean Medicine
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• v.35 no.2
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• pp.195-207
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• 2014

Objectives : The purpose of this study was to investigate how Rhei Radix et Rhizoma affects on insulin resistance and adipose tissue inflammatory response in high fat diet induced obese C57BL/6 mice. Methods : Obesity was induced in C57BL/6 mice by high fat diet for 12 weeks. Models were divided into 3 groups (n=6) of normal diet, high fat diet (HFD), and high fat diet with Rhei Radix et Rhizoma and investigated for 12 weeks. We measured body weight, FBS and oral glucose tolerance test (OGTT), serum insulin, homeostatic model assessment-insulin resistance (HOMA-IR), weight of liver and epididymal fat pad. Inflammatory markers such as adipose tissue macrophage (ATM), tumor necrosis factor-${\alpha}$ and interlukin-10 and CD68 of epididymal adipocyte were determined to evaluate the effect of Rhei Radix et Rhizoma on adipose tissue inflammation. Results : Compared with the HFD group, we observed loss of body weight and epididymal fat pad weight, improvement of glucose level and HOMA-IR, reduction of ATM and gene expression of TNF-${\alpha}$, CD68 in the high fat diet with Rhei Radix et Rhizoma group. Conclusions : This study suggests that Rhei Radix et Rhizoma has effects on insulin resistance and adipose tissue inflammatory response in high fat diet induced obese mice.

• Journal of the Korean Institute of Landscape Architecture
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• v.33 no.1 s.108
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• pp.19-32
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• 2005

The role of emotional responses is an important subject of study in consumer behavior. Although the perceived performance and satisfaction related emotions have been studied with increasing quantities in leisure studies or fields of outdoor recreation and tourism, issues concerning the appropriate way to measure these emotional responses remains unresolved. This article reviews the emotion measuring scales, and testify the usefulness of PAD scale based upon 349 questionnaires by users of Phoenix Park(Ski Resort) and Seoul Land(Theme Park) in Korea. It was found that, users' emotional response was closely related with satisfaction in Phoenix Park(Ski Resort); however, users' perceived performance was closely related with satisfaction in Seoul Land (Theme Park). This article argues that the meanings of these findings is due to different characteristics of consumption typology between ski resort and theme park. In conclusion, users' emotional experience may be more useful in understanding skiing activities and in formulating management strategies for ski resorts than theme parks.

• Advances in Traditional Medicine
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• v.10 no.3
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• pp.150-154
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• 2010

The immunosuppressive activity of the Methanol extract of bark of Madhuca longifolia (Koenig) consisting of a mixture of saponins, flavonoids, tannins, steroids, phenol and glycosides was studied on the immune responses in mice. Methanol extract of Madhuca longifolia (MLL) was administered orally at doses of 50, 100 and 150 mg/kg/day to healthy mice divided into four groups consisting of six animals each. The assessment of immunomodulatory activity was carried out by testing the humoral (antibody titre) and cellular (foot pad swelling) immune responses to the antigenic challenge by sheep RBCs. Furthermore, the effect on hematological parameters as well as relative organ weight was determined. On oral administration MML showed a significant decrease delayed type hypersensitivity (DTH) response whereas the humoral response to sheep RBCs was unaffected. Thus MLL significantly suppressed the cellular immunity by decreasing the footpad thickness response to sheep RBCs in sensitized mice. With a dose of 100 and 150 mg/kg/day the DTH response was $7.66{\pm}2.75$ and $6.41{\pm}1.21$ respectively in comparison to corresponding value of $14.50{\pm}2.38$ for untreated control group. These differences in DTH response were statistically significant (P < 0.05). The study demonstrates that MLL shows preferential suppression of the components of cell-mediated immunity and shows no effect on the humoral immunity.

• Tribology and Lubricants
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• v.33 no.1
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• pp.9-14
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• 2017

This paper presents a rotordynamic analysis and the operation of a power turbine applied to a 250 kW super-critical $CO_2$ cycle. The power turbine consists of a turbine wheel and a shaft supported by two fluid film bearings. We use a tilting pad bearing for the power turbine owing to the high speed operation, and employ copper backing pads to improve the thermal management of the bearing. We conduct a rotordynamic analysis based on the design parameters of the power turbine. The dynamic coefficients of the tilting pad bearings were calculated based on the iso-thermal lubrication theory and turbine wheel was modeled as equivalent inertia. The predicted Cambell diagram showed that there are two critical speeds, namely the conical and bending critical speeds under the rated speed. However, the unbalance response prediction showed that vibration levels are controlled within 10 mm for all speed ranges owing to the high damping ratio of the modes. Additionally, the predicted logarithmic decrement indicates that there is no unstable mode. The power turbine uses compressed air at a temperature of $250^{\circ}C$ in its operation, and we monitor the shaft vibration and temperature of the lubricant during the test. In the steady state, we record a temperature rise of $40^{\circ}C$ between the inlet and outlet lubricant and the measured shaft vibration shows good agreement with the prediction.

• The KSFM Journal of Fluid Machinery
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• v.12 no.5
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• pp.47-53
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• 2009

A rotordynamic and detailed stability analysis in accordance with API 617 standard were performed with a turbo-compressor, which is one of key rotating machinery in refinery, petroleum, and power plants. The system is composed of rotor shaft, impeller, sleeve hub, balance drum, and coupling hub. The rotor system is supported by tilting pad bearings, which has 5 pads and pad on loading condition. The rotordynamic analysis specified by API 617 includes the critical speed map, mode shape analysis, Campbell diagram, unbalance response analysis, and stability analysis. In particular, the specifications of stability analysis consist of a Level 1 analysis that approximates the destabilizing effects of the labyrinth seals and aerodynamic excitations, and Level 2 analysis that includes a detailed labyrinth seal aerodynamic analysis. The results of a rotordynamic analysis and stability analysis can evaluate the operating compressor health and can be utilized as a guide of its maintenance, repair and trouble solution.

• The KSFM Journal of Fluid Machinery
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• v.13 no.3
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• pp.43-48
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• 2010

In this study rotordynamic characteristics of an air turbo-compressor (ATC) used in oxygen plant are analyzed and its operating-speed balancing is performed to solve the vibration trouble caused by rotor unbalance. Three dimensional model of the ATC rotor is completed and then analytical FE (finite element) model, which is verified by experimental modal testing, is developed. A rotordynamic analysis includes the critical map, Campbell diagram, and unbalance response, especially considering the pedestal housings supporting tilting pad bearings. A test run of operating-speed, using tilting-pad bearing of actual use, showed that the vibration level increased very sharply as approaching the rated speed. The operating-speed balancing specified by API 684 was carried out by using influence coefficient method. The results showed that the vibrations at the bearing pedestal housings represented good levels of 0.1 mm/s. From the test run and operating-speed balancing, the analytical results, that is, critical speeds are in good agreement with the test results and unbalance responses introducing the correction masses are similar to the as-is test responses in its aspect.

• Korean Journal of Pharmacognosy
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• v.27 no.3
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• pp.274-281
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• 1996

Ulmus parvifolia has been used as a traditional folk medicine to treat the carbuncle in deep skin. In this study, the effect of water extract of root bark of Ulmus parvifolia (WUP) on the carbuncle, pain, inflammation and hypersensitivity was evaluated in animal models. The administration of WUP significantly decreased the size of Staphylococcus aureus ($10^8$ cells/mouse)-induced carbuncle, and also exhibited analgesic activity in the HAc-induced writhing syndrome at doses of 50-500 mg/kg. It also showed significant anti-inflammatory activity in the carageenin- and complete Freund's adjuvant-induced inflammation. In the histamine-induced anaphylaxis, it decreased the percent of mortality by protecting mice treated with Bordetella pertussis. In the immune responses in the mice sensitized and challenged with sheep red blood cells, the Arthus reaction determined by swelling of foot pad at 4 h after challenge, HA titer, HY titer and PFC which can be used to evaluate the humoral immune response were significantly suppressed by oral administration of WUP at doses of 100 and 200mg/kg. The cellular immune responses in the same mice such as delayed type hypersensitivity determined by swelling of foot pad at 24 h after challenge and RFC were also significantly suppressed in the same manner.