• Elastomers and Composites
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• v.53 no.4
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• pp.202-206
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• 2018

Five solution styrene butadiene rubber/neodymium butadiene rubber (SSBR/NdBR) composites were manufactured using different ratios of SSBR and NdBR. In this study, the composites were reinforced with NdBR and silica to confirm the physical properties of SSBR used for treads of automobile tires and the dispersibility with silica. The morphologies of the rubber composites were observed using field-emission scanning electron microscopy (FE-SEM). The crosslinking behaviors of the composites were tested using a rubber process analyzer (RPA), and the abrasion resistances were tested using a National Bureau of Standards (NBS) abrasion tester. The hardness values, tensile strengths, and cold resistances of the composites were also tested according to ASTM standards. Increased NdBR content yielded composites with excellent crosslinking properties, abrasion resistances, hardnesses, tensile strengths, and cold resistances. The crosslinking point increased due to the double bond in NdBR, thereby increasing the degree of crosslinking in the composites. The NdBR-reinforced composites exhibited excellent abrasion resistances, which is explained as follows. In SSBR, a breakage is permanent because a resonance structure between styrene and SSBR forms when the molecular backbone is broken during the abrasion process. However, NdBR forms an additional crosslink due to the breakdown of the molecular backbone and high reactivity of the radicals produced. In addition, the low glass transition temperature (Tg) of NdBR provided the rubber composites with excellent cold resistances.

• New & Renewable Energy
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• v.20 no.1
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• pp.116-125
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• 2024

Ultra-low-head is an unexplored classification among the sites in which hydroelectric power can be produced. This is typically owing to the low power output and the economic value of the turbines available in this segment. A turbine capable of operating in an ultra-low-head condition without the need of a dam to produce electricity is developed in this study. A gate structure installed at a shallow water channel acting as a weir generates artificial head for the turbine mounted on the gate to produce power. The turbine and generator are designed to be compact and submersible for an efficient and silent operation. The gate angle is adjustable to operate the turbine at varying flow rates. The turbine is designed and tested using computational fluid dynamics tools prior to manufacturing and experimental studies. A parametric study of the runner blade parameters is conducted to obtain the most efficient blade design with minimal hydraulic losses. These parameters include the runner stagger and runner leading edge flow angles. The selected runner design showed improved hydraulic characteristics of the turbine to operate in an ultra-low-head site with minimal losses.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.6
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• pp.1762-1772
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• 1996

The main objective of this study is to develop a gripper mechanixm that can be employed for assembly and removal tasks of a nozzle-dam of steam genetator in the process of the nuclear reactor maintenances. Brief description of the open-close thpe gripper mechanism, its position analysis, and its kinematic analysis are given. The optimal design of the gripper mechanism with and without slipping on its two gipping surfaces is considered. As an optimal design index, the ratio of the actuator force of prismatic cylinder to gripping load is proposed. Then, based on this index the oiptimal design is carried out to identify values of optimal design parameters for the gripper dechanism.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.133-137
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• 2007

As the waterpower generation plant, the subject of this Study, is a facility that produces plenty of electricity corresponds to $196{\sim}240GWh$ annually, and in its generation process it creates a loud noise when the turbine related to the hydraulic turbine dynamo revolves, and since such loud noise must be transmitted to the dynamo room and amplified, it is effecting a lot of influences to the adjacent office and space. In such viewpoint, this Research, based on the soundproof measure presented at the preceding research, has attempted to evaluate about the effect of noise-reduction countermeasure against the hydraulic turbine dynamo using Auralizational Technique through Psycho-Acoustics Experiment. It deems that such result could be applied hereafter as the useful material when setting up a soundproof countermeasure for the hydraulic turbine dynamo room in dam.

• Environmental Engineering Research
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• v.16 no.1
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• pp.41-45
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• 2011

The aim of this investigation was to demonstrate a rapid bioluminescence bioassay for comparison of the toxicity of whole solids and the aqueous extracts of various environmental solid samples. With regard to the toxicities, those for the soil extracts were mostly found to be lower than those of whole soils, which may have been caused by un-extracted pollutants or dilution during the extraction process. Solid samples from dam-reservoir sediments and municipal refuses were also tested. The toxicities of the solid extracts (0-34%; refuses and sediments) were much lower than those of the whole solids (13-91%). The bioluminescence inhibition test indicated that the harmful effects of the contaminated solids samples were greater than those of the solid extracts.

• Spatial Information Research
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• v.8 no.1
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• pp.131-140
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• 2000

The systematic data management system in the area of river flow analysis has not yet constructed, even though the need is evident due to the complicated process of tremendous input/output data in the modeling study and the importance of visualization of spatial flow variation. The objectives of this study are to suggest the method for constructing the NGIS-based river database based on contour, river, elevation, boundary layers and river cross sections and to provide the algorithm for interpolating equi-distance river cross section points. The selected study area is the main Han River starting from Paldang dam site to Indogyo bridge. The constructed database will be useful for the scientific water flow management system in the study area.

• Journal of information and communication convergence engineering
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• v.7 no.2
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• pp.131-134
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• 2009

The red-eye effect in photography occurs when using a photographic flash very close to the camera lens, in ambient low light due to in experience. Once occurred, the photographer needs to remove it with image tool that requires time consuming, skillful process. In this paper, we propose a new method to extract and remove such red-eye area automatically. Our method starts with transforming ROB space to YCbCr and HSI space and it extracts the face area by using skin color information. The target red-eye area is then extracted by applying 8-direction contour tracking algorithm and removed. The experiment shows our method's effectiveness.

• Journal of Industrial Technology
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• v.3
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• pp.95-101
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• 1983

This study aims at the determination of the coefficienties of runoff and infiltration affecting runoff. The rating curve is more available than the peak flood runoff to determine flood control plan of flood control reservoir and the volume of hydroelectric power plant, or to make multipurpose dam. In hydrologic analysis and design, it is necessary to develop relations between precipitation and runoff, possible using some of the factors affecting runoff as parameters. In order to calculate the runoff discharge, the runoff process constituting elements are divided to the surface runoff, the subsurface runoff and the groundwater runoff. By comparing the computed hydrograph with the measured hydrograph, determinned the watershed TANK Model constant Varying the tank model constant for approximating the computed hydrograph to the measured hydrograph.

• CELLMED
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• v.7 no.4
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• pp.19.1-19.5
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• 2017

Fasad i.e. venesection is an old classical method of treatment in the Unani system of medicine. Fasad is Arabic word which means "to open". In the process, complete evacuation which drains out blood and dominating humours mixed with blood from veins. Fasad is carried out when the kamiyat (quantity) of the blood is excess in the body and patient is either exposed to the risk of developing a disease or has actually developed one. In classical literature of Unani system of medicine, physicians wrote a lot about this procedure. The details of venesection is mentioned in the given paper on the basis of classical literature including history, indications, types, amount of blood to be venesected, time, person, procedure, complications and special focus has been made on the number of vessels to be venesected and their benefits with respected to disease and condition.

• Journal of environmental and Sanitary engineering
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• v.17 no.3
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• pp.46-51
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• 2002

This study was performed to treat a sewage at the upper stream of dam using modified sequencing batch reactor, During the operating period, average $COD_{cr}$, removal efficiency was about 85% but average T-N and ${PO_4}^{3-}-P$ removal efficiencies were 43% and 30% respectively. Because the organic matter was very low compared with nitrogen and phosphorous in influent($BOD_{5}/{NH_4}^{+}-N{\;}={\;}2,{\;}BOD_{5}/{PO_4}^{3-}-P{\;}={\;}15.6$), nitrogen and phosphorus removal efficiency was relatively low. Average nitrogen removal efficiency was 50 % at $10^{\circ}C$ or above and it was 36 % at $10^{\circ}C$ or below. As reactor was located in outdoor without any thermostat, temperature decreased at least $2.4^{\circ}C$ in the winter season. Therefore, if we would apply this modified sequencing batch reactor to sewage which concentration of organic matter was very low compared with nitrogen and phosphorous, we have to addition of external carbon and installation of any thermostat.