• Journal of Convergence for Information Technology
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• v.11 no.10
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• pp.270-276
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• 2021

The purpose of this study was to investigate the effects of home care hair treatment characteristics and frequency on hair during permanent wave treatment. The hair treatments distributed on the market were classified into cationic surfactants and silicone oil. Hair treatment was performed 5 times, 10 times, 20 times differently according to the frequency of use, and hair permanent wave was performed. The hair thickness, tensile strength, epidermal observation using SEM, and hair component analysis using EDS were performed as experimental methods. The results of the experiment showed that the natural-derived ingredient was the main ingredient, and the cationic surface activity and silicon oil-free product group had high hair protection effect. Therefore, the product group using natural ingredients should be further researched and developed, and the study on the method and frequency of use of products with irritant chemical ingredients should be conducted.

• Applied Chemistry for Engineering
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• v.22 no.2
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• pp.149-154
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• 2011

In order to explore properties of various rubber compounds after thermal aging under the condition similar to the operating environment of a fuel cell-stack, heat resistance and compression set of those compounds were investigated for a long term operation in $H_2SO_4$, $H_2O$, and LLC (ethylene glycol : $H_2O=50:50$) solution. It was assumed that aging Acrylonitrile butadiene rubber (NBR) and Elthylene Propylene diene rubber (EDPM) compound in the solution resulted in discoloration as time passed. It was also found that hydrolysis was developed on the Silicone rubber (VMQ) compound intentionally aged under acidic condition by means of TGA, SEM, and EDS analysis.

• Tribology and Lubricants
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• v.25 no.5
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• pp.285-291
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• 2009

In this work, durability characteristics of electrorheological (ER) fluid for damper application are experimentally investigated. ER fluid is prepared by using phosphorated starch particles and silicone oil. The field-dependent Bingham characteristics and response time for the proposed ER fluids are experimentally obtained. Experimental apparatus of durability test for ER fluid is established with cylindrical ER cylinder for mid-sized passenger vehicle. In order to evaluate the durability characteristics of ER fluid as a function of time, damping force and temperature variations are measured until one million cycles. After durability test, Bingham characteristics and response time of ER fluid are measured and compared to the initial properties. Microscopic pictures of ER fluid are taken to validate the changes of properties. The results indicate that the ER fluid can be commercially utilized in vehicle damper system with its durability performance. Moreover, the understanding of durability characteristics is essential to predict the service life of ER fluid as well as to design its applications.

• Tribology and Lubricants
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• v.15 no.3
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• pp.240-247
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• 1999

The electrorheological (ER) behavior of suspensions in silicone oil of phosphoric ester cellulose particles (average particle size : 18$\pm$1${\mu}{\textrm}{m}$) coated with octadecylamine ( $C_{18}$ $H_{37}$ N $H_2$) as surfactant was investigated at room temperature. For development of anhydrous ER suspension using at real application, it should be researched how can reduce deposition of ER particles in ER suspension. Anhydrous ER suspensions mixing with phosphoric ester cellulose particles coated with octadecylamine were measured. As increasing the coating concentration of octadecylamine, not only analysis of electrical properties such as dielectric constant, current density and electrical conductivity but also rheological properties of ER suspensions were studied. From the experimental results, coating concentration of surfactant had large influence to ER properties of anhydrous ER suspension. Current density, conductivity and electrorheological effect ($\tau$/$\tau$$_{0}$) of ER suspension were linearly reduced with increasing the coating concentration of octadecylamine. But ER suspensions dispersed the phosphoric ester cellulose particles coated with octadecylamine showed reducing deposition of ER particles and could be redispersed easily.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.1
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• pp.119-125
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• 1997

This paper deals with an experimental investigation on an active vibration control of ahybrid smart structure(HSS) via an electro-rheological fluid actuator(ERFA) and a piezoelectric film actuator(PFA). Firstly, an HSS is constructed by inserting a silicone oil-based electro-rheological fluid into a hollow can- tilevered beam and perfectly bonding piezoelectric films ofn the upper and lower surfaces of the beam as an actuator and a sensor, respectively. The control scheme of the ERFA tuning stiffness and damping charac- teristics of the HSS with imposed electric fields is formulated as a function of excitation frequencies on the basis of field-dependent respnses. On the other hand, as for the control scheme of the PFA permitting control voltages to generate axial forces or bending moments for suppressing deflections of the HSS, a neuro sliding mode controller(NSC) is employed. Furthermore, an experimental implementation activating the ERFA and the PFA independently is established to carry out an active vibration control in both the transient and forced vibrations. The experimental results exhibit a superior ability of the gtbrid actuation system to tailor elastodynamic response characteristics of the HSS rather than a single class of actuator system alone.

• Tribology and Lubricants
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• v.14 no.3
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• pp.7-16
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• 1998

The electrorheological (ER) behavior of suspensions in silicone oil of phosphoric ester cellulose powder (average particle size: 17.77 $\mu$m) was investigated at room temperature with electric fields up to 2.5 KV/mm. For development of anhydrous ER suspensions using at wide temperature range, we aimed to know the effect of activation of phosphoric ester cellulose particles on the ER activities. As a first step, the anhydrous ER suspensions mixing with the phosphoric ester cellulose particles which were treated with 2M phosporic acid and 4M urea were measured. After activating the anhydrous ER suspensions at 12$0^{\circ}C$, not only the analysis of dispersing cellulose particles which were reacted by phosphoric ester but also the electrorheological characteristics of ER suspensions such as dielectric constant, current density, electrical conductivity and rheological properties were studied. From the experimental results, the activation of phosphoric ester cellulose particles had an influence on the ER properties of anhydrous ER suspensions. As the activation time went by, the size and number of dispersing particles, the electrical properties and the initial apparent viscosity $(η_0)$ of ER suspensions were increased till the activation time passed 5 hours. Also, it was possible, the electrorheological effect $($\tau$/$\tau$_0)$ of ER fluids was grown by the activation of phosphoric ester cellulose particles.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1993.11a
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• pp.85-89
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• 1993

Silicone oil exhibits the properies of both organic and inorganic substances and, thus, it has many superior properties such as higher thermal resistance and lower thermal oxidation level when compared to other dielectric liquids. In order to investigate the dielectric characteristics, dielectric liquids of viscosity 1 [cSt] is chosen as the specimen and experiment is performed in the temperature range of 20∼65 [$^{\circ}C$] and frequency range of 30∼1${\times}$10$\^$6/ [Hz] respectively. As a result, the observed linear decrease in dissipation factor at the frequency range below 3 [kHz] is due to the influence of frequency, whereas the increase in dissipation factor at higher frequency range is contributed by electrode's resistance. At a fixed frequency of 30 [kHz], increasing temperature results in higher peak value and wide width of the absorption curve. This is due to the increase in dipole and viscosity. As temperature increases, dipole moment is decreased from 0.98 to 0.64 [debye]. The activation energy which causes the relaxation and loss of dielectric is obtained about 15 [kcal/mole].

• Journal of Magnetics
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• v.19 no.4
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• pp.345-348
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• 2014

Magnetorheological suspensions (MRSs) are smart materials that have the potential to revolutionize several industrial sectors because of their special rheological behaviors. In this paper, MRS, based on carbonyl iron (CI) microparticles that were dispersed in silicone oil with oleic acid, were prepared. We showed that the electroconductibility of MRS was significantly influenced by the intensity of the external magnetic field that was applied. The resistance value can vary from infinite to below $300{\Omega}$ after applying an external magnetic field. The results indicated that this MRS had the property of magnetic-field-tuned insulator to conductor transition. This system has potential applications in controllable MRS electrical devices.

• Journal of Drive and Control
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• v.16 no.4
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• pp.87-92
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• 2019

Rotary dampers are damping devices which provide high resistance to shaft rotation. Rotary dampers are being used in various areas to enable the gentle opening and closing of the rotation motion relative to home furniture, industry machinery and automotive parts. Rotary dampers can be installed directly at the rotating point of a various part and can achieve uniform, gentle movement which increases quality and value of products. And generally, the silicone fluid is used as the damping medium because of its stable viscous properties. The movement of these little decelerators can be achieved with a high viscosity of working fluid and throttles installed in the body of the rotary damper. The damping force can be achieved clockwise, anti-clockwise or in both directions according to the structure of the orifices or throttles. In this paper, the torque performances of the rotary damper containing air in the working fluid were studied. For this purpose, the torque characteristic of the rotary damper according to the variation of various operating conditions such as clearance of leakage, dimensions of groove orifice, content ratio of air, etc., were simulated with AMEsim software.

• Journal of Power System Engineering
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• v.10 no.2
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• pp.29-35
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• 2006

Two-dimensional numerical simulation has been performed to investigate mixed convection heat transfer between inclined parallel plates with bottom-heated and top-cooled uniformly. The ratio of parallel plate length to height is 9.33, Prandtl number is 909(that of silicone oil at 298K) and Rayleigh number is 8600. In the ranges of the Reynolds number Re from 0 to 1.8 and the angle of inclination ${\theta}$ from 0 to 90 degree. The governing equations are discretized using the finite volume method. In this study, the effects of the Reynolds number, the angle of inclination, and the local and mean Nusselt numbers are presented and discussed. It is found that the periodic flow of mixed convection between inclined parallel plates is shown at $0^{\circ}{\leq}\;{\theta}<30^{\circ},\;Re<0.063$, and the flow pattern can be classified into three patterns which depend on Reynolds number and the angle of inclination. The minimum average Nusselt numbers occur at Re=0.05 regardless of the angle of inclination.