• Nutrition Research and Practice
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• 제13권1호
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• pp.17-22
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• 2019

BACKGROUND/OBJECTIVES: Successful recovery of an animal from exercise is essential, especially prior to the next exercise session. This study was conducted to find an effective exercise-to-rest period ratio for the restoration of energy sources and replenishment of anti-oxidative status in tissue after exercise. MATERIALS/METHODS: Thirty-two rats were assigned to either non-training or training exercise groups for 5 weeks. After that period, the two groups were subdivided into four smaller groups: non-exercise (NE), exercise 0.5 hour and rest 1 hour (ER0.5:1), exercise 1 hour and rest 1 hour (ER1:1), exercise 2 hours and rest 1 hour (ER2:1). RESULTS: In the training group animals and compared to the NE group, the levels of plasma glucose after the rest period were significantly high in all ER groups but highest in the ER2:1 group. Similarly, the liver glycogen level was highest in the ER2:1 group. The plasma FFA level reached the highest level in the ER2:1 group but was similarly high in the ER0.5:1 group. Liver TG level was unchanged in the ER2:1 and ER1:1 groups but was significantly high in the ER0.5:1 group. Muscle TG levels were decreased in all three ER groups. Plasma protein levels were significantly high in the ER2:1 and ER0.5:1 groups. In both training animal and non-training animals, the liver protein levels did not change significantly between the NE and ER groups, irrespective of the exercise-to-rest ratio. In the training animal group, muscle protein level was significantly low in the ER2:1 and ER0.5:1 groups. The activity levels of superoxide dismutase and catalase, as well as the malondialdehyde concentration, were not significantly different between NE and ER groups, irrespective of the exercise-to-rest period ratio. CONCLUSIONS: These results indicate that animals provided with a 0.5:1 to 1:1 exercise-to-rest period ratio can restore their muscle energy sources and recover their anti-oxidative defense system.

• Tribology and Lubricants
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• 제25권5호
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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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• 제15권3호
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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.

• 한국정밀공학회지
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• 제18권9호
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• pp.45-52
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• 2001

This paper presents two different models of electrorheological(ER) valves which can be applicable to an automatic cargo handling system at the seaport. Four different ER fluids, which are commercially available, are adopted and their Bingham characteristics are experimentally evaluated with respect to the intensity of electric field. The field-dependent Bingham models are used in the design of two types of ER valves; single-type and divided-type. The governing equations of motion of the ER valves are derived and the principal design parameters are determined based on 200ton platform to be vertically controlled by the ER valves. Both pressure drops due to the applied field and current density required to operate the ER valves are analyzed. In addition, the pressure drops of the cylinder system are evaluated for both ER valves.

• 한국기계가공학회지
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• 제3권1호
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• pp.84-89
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• 2004

This study is a basic one for application of ER Fluid to fluid power systems. By mixing silicone oil with zeolite particles, four kinds of ER fluids were made, in which the weight ratio of zeolite particles are different. We examined how the Yield shear stress and Bingham characteristics of the ER fluids are effected by varying electric field intensity. We designed and constructed a disk type power transmission clutch in which ER fluid fills and this ER fluid transmits the power of drive shaft to the driven shaft. With this equipment, the revolution transmission ratio from the chive shaft to the driven shaft by varying electric field density of the ER fluid was examined.

• 한국공작기계학회논문집
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• 제12권6호
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• pp.29-35
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• 2003

In this research 4 plate type ER-Valves which have same surface but different width and length are designed and an experimental apparatus is constructed. With this experimental apparatus, flow rate and pressure drop of ER fluid flowing in ER-valves are measured with varying electric field strength of ER-valve, and relation between valve types and pressure drop is also experimented. ER fluid is made silicon oil mixed with 40wt% starch having hydrous particles. If we allow the same electric field in the ER-Valve, we came to how that the pressure drop is effected by the electrode length and electrode width. When the strength of the electric field increased, the pressure drop happened big and the flow rate decreased.

• 한국안전학회지
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• 제12권4호
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• pp.47-56
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• 1997

This paper presents the vibration control of an engine mount featuring an ER(electro-rheological) fluid. The Bingham properties of the ER fluid to be employed to the ER engine mount are experimentally obtained through Coeutte type viscometer. The ER engine mount is devised ant its governing equation is derived. After evaluating the performance of the ER engine mount on the basis of the mathematical model, the novel type of the ER engine mount is then designed and manufactured. The electric field-dependent transmissibility of the ER engine mount is evaluated by changing the particle concentration and the electrode gap size. To investigate the control performance of the ER engine mount, neuro-control algorithm is adopted. It is shown that the proposed ER engine mount has prominent capabilities of controlling the damping force by tuning the electric fields and excellent vibration isolation performance.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 춘계학술대회논문집
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• pp.489-494
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• 2002

This paper presents hydraulic model which can capture the hysteric damping force behavior of ER damper. A flow mode rue ER damper is manufactured, and its field-dependent damping forces are measured. Newly proposed hydraulic model which derived from physical hydro-mechanical parameters of ER damper are conventional Bingham model are investigated to represent the field-dependent damping force characteristics of ER damper. After principal parameters of two models are estimated from the measured damping forces data, the force vs velocity hysteresis cycles are then reconstructed. The results show that the proposed hydraulic model can capture the hysteresis behavior of ER damper accurately.

• 유변학
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• 제10권3호
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• pp.143-151
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• 1998

실리콘 오일에 인산처리 셀룰로오스 분말을 분산시킨 비수계 전기유변성(ER) 유체 의 전기유변 거동을 상온에서 최대 2.5KV/mm의 전기장하에서 실험하였다. 넓은 온도 영역 에서 사용이 가증한 비수계 ER 유체를 개발하기 위해 셀룰로오스의 인산 에스테르 반응이 ER 유체의 전기유변효과에 미치는 영향을 조사하였다. 먼저 여러 가지의 인산처리 농도로 처리된 인산처리 셀룰로오스 미립자를 분산시킨 ER 유체를 제조한 후 ER 유체의 유전상수, 전류밀도 및 전기전도도 등과 같은 전기적 특성을 측정하였으며 ER 유체의 전기유변 특성 또한 측정하였다. 인산처리 셀룰로오스가 분산된 비수계 ER 유체의 전류밀도는 셀룰로오스 의 인산 에스테르 반응에서의 인산처리 농도에 의해 조절할수 있음을 알수있었으며 셀룰로 오스의 인산처리 농도가 2.5 M과 3.0 M 사이일 때 인산처리 셀룰로오스가 첨가된 비수계 ER 유체의 전기유변효과 ($\tau$/$\tau$0)가 가장 높게 측정되었다.

• Journal of Plant Biology
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• 제37권3호
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• pp.293-299
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• 1994

Developing rice endosperm cells display two morphologically distinct rough endoplasmic reticulum (ER) membranes, the cisternae ER (C-ER) and theprotein body ER (PB-ER), the latter delimiting the prolamine protein bodies. We (Li et al., 1993) have recently shown that the storage protein mRNAs are not randomly distributed on these ER types; the C-ER is enriched for glutelin mRNAs, whereas the PB-ER harbors predominantly prolamine transcripts. To address whether these ER types have differnet capacities to translate these mRNAs and translocate their proteins into the lumen, a microsomal fraction enriched in C-ER vesicles was prepared from devleoping rice seeds. When present in an in vitro translatin system, the microsomes were able to proteolytically remove the signal peptide and internalize both preproglutelin and preprolamine within the microsomal vesicles. Of the two species, preprolamine was more effectively translocated and processed. These results suggest that the C-ER has the capacity to recognize and bind both storage protein mRNAs during protein synthesis. Moreover, efficient translocation and processing of glutelin requires additional factors that are deficient or absent in the in vitro system.