• Journal of Power System Engineering
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• v.1 no.1
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• pp.98-105
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• 1997

In general, crankshafts which are used in internal combustion reciprocating engines are subjects to high torsional vibration. Therefore, a damper is often used to minimize the torsional vibration in reciprocating engines. In this paper, in order to investigate damping performance of viscous damper, the real effective viscosity and complex damping coefficient of silicone oil, and the effective inertia moment of inertia ring are calculated considering the relative motion between damper casing and inertia ring. Based on these results multi-cylinder shaft is modeled into equivalent 2-degree of freedom system and optimum condition is estimated by calculating the amplification factor of viscous damper. Also the test damper was manufactured according to the result of theoretical investigation, the performance and durability was ascertained through experimental examination.

• Journal of the Korean Chemical Society
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• v.7 no.2
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• pp.106-114
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• 1963

The products from polymer pyrolysis at $450^{\circ}$ are cooled with ice, then liquid and gaseous portions are analysed by gas chromatography. Di-2-ethyl hexyl sebacate column, silicone oil column, silica gel column and tetraethyleneglycol dimethylether column, which was most effective for the separation of hydrocarbon gases, are used. Identification of isomers could be secured more effectively by gas chromatography than mass spectrometry. Elucidation of the mechanism for thermal decomposition of polymers could be done through the identification of pyrolysis products. Although more extensive work is needed, some patterns of polymer pyrolysis are discussed.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2248-2253
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• 2008

A numerical study on oscillatory thermocapillary flow in half-zone has performed to understand the effect of axial rotation. 2d unsteady code is developed to observe the onset of oscillation. 2cs Silicone oil with Prandtl number of 26.5 is used as a working fluid. The critical temperature difference at onset of oscillation is investigated under the different aspect ratios and rotation modes. It is shown that the onset of oscillation is delayed when aspect ratio reduces and rotating speed increases. The oscillatory flow is strongly reduced under top rotation and co-rotation modes, while it is augmented under bottom rotation and counter-rotation modes. It is thought that interaction between return flow and bottom wall is important to explain the oscillatory flow.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.601-604
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• 2001

The insulation materials of cables used for underground power transmission requires a higher insulating capability, and the most popular method to examine the cable is partial discharge test due to applying variation voltage. In the thesis, air void, silicone oil, of which may possibly exist real cables, are simulated by Electro 2D program. Also the relations between calculated field strength and the void defect type in the cable joint materials. In the modeling, eclectic field inner to the cable joint material composed by XLPE and EPDM is modeling simulated. We obtained the electric field distribution in void due to two conditions.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.11a
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• pp.77-80
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• 2000

In order to determine what influences the interfacial charge in EPDM/XLPE laminates, We used PEA (pulsed electroacoustic) method. Interfacial properties such as space charge accumulation and breakdown strength in crosslinked polyethylene (XLPE)/ethylene-propylene-diene monomer (EPDM) laminates were investigated. Interfacial charge develops when the EPDM is laminated with XLPE. It showed the positive polarity same as the simulation in case on intercase of EPDM/XLPE. In case of coupling agent added silicone oil, as increasing the content of coupling agent, the interfacial charge decreased. Details of the results are given and their origins discussed.

• Proceedings of the KIEE Conference
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• 1993.07b
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• pp.1174-1176
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• 1993

Morphology of low density polyethylene(LDPE) such as the degree of crystallinity changes with thermal history etc. In order to clarify the effects of morphological changes on electrical breakdown, we studied direct current and impulse breakdown phenomena of LDPE films heat-treated at 100[$^{\circ}C$] for 1[H] in silicone oil and subsequently cooling to various ways. The degree of crystallinity was estimated by the infra red absorption and X-ray diffraction measurements for the specimens of slowly cooled, cooled in water, original, and cooled in liquid nitrogen gas. As the result, we obtained that the first, second, third, and fourth was slowly cooled of 70.23[%], cooled in water of 61.6[%], original specimen of 56.75[%], and cooled in liquid nitrogen gas of 34.7[%] respectively. The crystalline size and distribution of specimens were researched by Differential scanning calolimeter measurements.

• KSTLE International Journal
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• v.8 no.2
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• pp.21-25
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• 2007

The electrorheological effect of the suspension composed of Bismark Brown chitosan succinate as the dispersed phase in silicone oil was investigated. Bismark Brown chitosan succinate suspension showed a typical ER response (Bingham flow behavior) upon application of an electric field. The shear stress for the suspension exhibited the dependence with a factor equals to 1.84 power on the electric field. The experimental results for the suspension correlated with the polarization model and Bismark Brown chitosan succinate suspension behaved as an anhydrous ER fluid. On the basis of the results, Bismark Brown chitosan succinate suspension showed the ER flow behavior upon application of the electric field due to the polarizability of the branched amide and amine polar groups of the Bismark brown chitosan succinate particles.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1997.10a
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• pp.451-455
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• 1997

This paper presents vibration mode control of a smart plate containing electro-rheological (ER) fluid between elastic face layers. Following the composition of a silicone oil-based ER fluid, the ER fluid-embedded plate partitioned into four sections is constructed. Then, an extensive modal test is experimentally carried out to identify field-dependent modal parameters such as mode shapes and natural frequencies of the structure with respect to different are subjected to electric fields. The distilled results from the experiment exhibit that the ER fluid can be effectively employed in a continuous fashion to tune modal behaviors of the distributed parameter systems,

• Journal of Industrial and Engineering Chemistry
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• v.68
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• pp.342-349
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• 2018

Polystyrene (PS) was coated on carbonyl iron (CI) particles via dispersion polymerization to produce core-shell structured CI/PS particles and adopted as magnetorheological (MR) material. Two MR fluids were prepared by dispersing CI/PS and CI particles in silicone oil. Their MR and tribological properties were investigated using a rheometer and a reciprocating friction and wear tester, respectively. Experimental data showed that tribological properties of MR fluid based on CI/PS particles are significantly enhanced compared to those of CI based MR fluid. Sedimentation problem of CI/PS MR fluid was also expected to be improved due to relatively lower density of CI/PS particles.

• Journal of Magnetics
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• v.21 no.4
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• pp.616-621
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• 2016

This paper presents a new multifunctional active guidewire system for medical applications that uses a magnetic microrobot. The study demonstrated that the proposed microrobot system could swim and be controlled under Low-Reynolds-number (Re) environments in blood vessel models. The prototype of the robotic guidewire, which is driven within a three-axis Helmholtz coil system, consists of a guide-wire, spiral blade, drilling tip, and permanent magnet. The spiral-type microrobot showed stable active locomotion between 3 kA/m and 9.1 kA/m under driving frequency up to 70 Hz in a silicone oil (of viscosity 1000 cst). The microrobot produced a maximum moving velocity of $8.08{\times}10^{-3}m/s$ at 70 Hz and 9.1 kA/m. In particular, the robotic guidewire produced 3D locomotion with drilling in the three-axis Helmholtz coil system. We verified active locomotion, towing of guidewire, steering, and drilling of the proposed robotic guidewire system through experimental analyses.