• Design & Manufacturing
• /
• v.11 no.2
• /
• pp.29-36
• /
• 2017

In this study, the non-contact type bicycle generator system considering the recharge is developed to use the eco-friendly energy source when the bicycle is operating. The following three main factors are considered in this study. One of factors is that the intensity of the rotating magnet is in the range of 2,700~4,300 [Gause]. The next factor is that the separation distance of rotating magnet and bicycle rim is in the range of 1.5-3.0 mm. The last factor is that the pedaling speed is in the range of 55 RPM [Wheel speed 5.6Km]~150 RPM [Wheel speed 15.25Km] consirering with the 5 staged gear transmission. The obtained results are as followed. (1) The generator output voltage gradually increases from 3V to 10V with the pedaling speed increases, at the separation distance is less than 2.5 mm and the operating voltage of the LED lamp is generated at a pedaling speed of 60 RPM or more. (2) The output current of the generator increases from 20mA to 40mA with the pedaling speed increases, at a separation distance is less than 2.0 mm and the operating current of the LED lamp is generated at a pedaling speed of 60 RPM or more. (3) When the separation distance was 3.0 mm, the output voltage and current are significantly lower than those of the bicycle LED lamp is generated. (4) The charging time is expected to be 12.24 ~ 17.65 hours when the magnitude of the magnet is 3,400[Gauss] at a pedaling speed of 55 RPM or more. (5) As a result of this study, it is thought that the non-contact type bicycle generator system considering the recharge can replace the conventional friction power generation system.

• 한국신재생에너지학회:학술대회논문집
• /
• 2008.10a
• /
• pp.51-54
• /
• 2008

This study aims to devise and analyze a power generation system combining the solid oxide fuel cell and oxy-fuel combustion technology. The fuel cell operates at an elevated pressure, a constituting a SOFC/gas turbine hybrid system. Oxygen is extracted from the high pressure cathode exit gas using ion transport membrane technology and supplied to the oxy-fuel power system. The entire system generates much more power than the fuel cell only system due to increased fuel cell voltage and power addition from oxy-fuel system. More than one third of the power comes out of the oxy-fuel system. The system efficiency is also higher than that of the fuel cell only system. Recovering most of the generated carbon dioxide is major advantage of the system.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.1 no.3
• /
• pp.189-196
• /
• 2013

In order for efficient recycling and eco-friendly treatment of construction waste, there is a need to apply a building separation and dismantling technique early on in the stage of waste generation. This study was conducted to analyze the relevant domestic circumstances and propose the applicable range of buildings in order to introduce a building separation and dismantling system to Korea. For this purpose, related policies and systems implemented overseas and the current situation of buildings were examined, and the workability of separation and dismantling of buildings according to their uses was compared. Also, the economic impact of the separation and dismantling system was examined and a survey was conducted, seeking the opinions of the relevant companies regarding the need for the system and the selection criteria for eligible buildings. Based on the results, it was determined that it would be impossible to apply the separation and dismantling system to all buildings in Korea, considering the current technical power and economic situation, and that the system should be introduced in phases, according to the building classification determined based on floor area and use, as the cost may vary depending on a number of variables including the level of difficulty and field conditions.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.17 no.1
• /
• pp.61-68
• /
• 2011

The "ship's routeing" system was adopted by IMO and has been operated on the major sea routes of all over the world for the prevention of marine casualty and the improvement of marine traffic flow. Thereupon, also in Korea, the "Hong-do" and "Bogil-do" sea routes on southern coast were designated to mandatory sea area by traffic separation scheme(TSS) in 2003, and the "Geomun-do" sea route on southern coast was designated in 2005. But there were few or no studies on the effect of designated traffic separation scheme in Korea. For this reason, in this paper, we evaluated the contribution of traffic separation scheme to the prevention of marine casualty and the improvement of marine traffic flow after designation of domestic traffic separation scheme using data of the marine casualties and ship's tracks from AIS information. The results of evaluation showed that on the contrary, the cases of marine casualties were increased on some sea routes and regular traffic flows were disturbed by some vessels after designation of traffic separation scheme. For the safer and better sea routes, alternative ideas such as reposition of ship's routing on "Hong-do" and "Bogil-do" sea areas were suggested.

• Journal of Hydrogen and New Energy
• /
• v.26 no.1
• /
• pp.45-53
• /
• 2015

The objective of this study is to develop a gas pro-treatment system for DME synthesis, wherein this system separates $CO_2$ from Flaring gas as Membrane, in order to save raw material ($CH_4$) cost of DME. In this study, hollow fiber membrane is developed, which is able to separate high-pressure gas, supported by polysulfone and coated with amorphous fluorinated polymer. Throughout the evaluation of the membrane's separation characteristics, the membrane is applied to this system. The membrane is designed by 2 stages for over 90% removal rate of $CO_2$ and over 90% recovery rate of $CH_4$. The bench scale of pro-treatment system is developed as $25Nm^3/hr$.

• Health Policy and Management
• /
• v.12 no.3
• /
• pp.23-35
• /
• 2002

Fiscal crisis in the medical insurance system has put the pressure upon hospitals by increasing the rate of curtailment, since the implementation of the separation of prescription and dispensing of medicine. The purpose of this study is to analyse the curtailment of mdical and drug expenditure before and after the system of separation between prescribing and dispensing and to suggest the problems about current inspection system. Data were obtained from 13 general hospitals and used for analysis of trends on medical & drug expenditure, and curtailment in 1999-2000 at three months intervals. The results were as follows; The scale of curtailment for drug expenditure has been increased on outpatient and inpatient since 2000. For the curtailed drug cost with outpatient, the ratio of curtailed drug expenditure has been increased in the case of prescription within the hospital. These results suggest that review system in social insurance were over-focused to control the cost and it might to impede the validity of review function in insurance system. Therefore, it' s needed to develope the scientific and reasonable criteria for Inspection and evaluation of durg expenditure.

• Progress in Superconductivity and Cryogenics
• /
• v.20 no.2
• /
• pp.6-10
• /
• 2018

Removal of iron oxide scale from feed-water in thermal power plant can improve power generation efficiency. We have proposed a novel scale removal system utilizing High Gradient Magnetic Separation (HGMS). This system can be applied to high temperature and pressure area. We have conducted the lab-scale model experiments using ${\varphi}50mm$ filters and it demonstrated high removal efficiency in HGMS, but scale-up of the system is required toward practical use. In this study, we conducted a large scale mock-up HGMS experiment. We used the superconducting solenoidal magnet with ${\varphi}400mm$ bore and demonstrated that our HGMS system can achieve sufficient scale removal capacity that is required to introduce into both off-line and on-line system.

• Journal of Korean Society of Water and Wastewater
• /
• v.24 no.3
• /
• pp.267-276
• /
• 2010

Many plants have been improved to adapt the target of the biological treatment processes changed from organics to nutrients since the water quality criteria of effluent was reinforced and included T-N and T-P for the municipal wastewater treatment plant. To meet the criteria of T-N and T-P, the conventional biological reactor such as aeration tank in activated sludge system is changed to the BNR (biological nutrient removal) processes, which are typically divided into three units as anaerobic, anoxic and oxic tank. Therefore, the solid separation process should be redesigned to fit the BNR processes in case of the application of the DAF (dissolved air flotation) process as an alternatives because the solid-liquid separation characteristics of microbial flocs produced in the BNR processes are also different from that of activated sludge system as well. The results of this study revealed that the microbial floc of the anaerobic tank was the hardest to be separated among the three steps of the unit tanks for the BNR processes. On the contrary, the oxic tank was best for the removal efficiency of nutrients as well as suspended solid. In addition, the removal efficiency of nutrients was much improved under the chemical coagulation treatment though coagulation was not indispensable with a respect to the solid separation. On the other hand, in spited that the separation time for the microbial floc from the BNR processes were similar to the typical particles like clay flocs, over $2.32{\times}10^3$ ppm of air volume concentration was required to keep back the break-up of the bubble-floc agglomerates.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.16 no.5
• /
• pp.22-28
• /
• 2008

A closed type crankcase ventilation system has been adopted to engines to prevent emission of blow-by gas to atmosphere. In the early closed type crankcase ventilation system, blow-by gas which contains engine lubricating oil is re-circulated into the intake system. The blow-by gas containing oil mist leads to increased harmful emissions and engine problems. To reduce loss of the engine oil, a highly-efficient oil separation device is required. Principle of a cyclone oil separator is to utilize centrifugal force in the separator and, therefore, oil separator designs depend on rotational flow which causes the centrifugal force. In this paper, flow characteristics and oil separation performances for cyclone type designs are calculated with CFD methodology. In the CFD model, oil particle was injected on a inlet surface with Rosin-Rammler distribution and uniform distribution. The major design parameters considered in the analysis model are inlet area, cone length and outlet depth of the oil separator. As results, reducing inlet area and increasing cone length increase oil separation performance. Changes in outlet depth could avoid interference between rotational flow and outlet flow in the cyclone oil separator.

• Journal of Hydrogen and New Energy
• /
• v.22 no.1
• /
• pp.13-20
• /
• 2011

$SO_2$ has been absorbed and separated selectively by an ionic liquid from $SO_2/O_2$ mixture decomposed from sulfuric acid during the thermochemical SI cycle for the water splitting. In order to design and operate high pressure $SO_2/O_2$ separation system, the solubility of $SO_2$ in [EMIm]$EtSO_4$ (1-ethyl-3-methylimidazolium ethylsulfate) has been measured by Magnetic Suspension Balance at high pressure and temperature. Based on the measured solubility, a pressurized separation system was set up and operated. 194 L/h of $SO_2$($SO_2:O_2$=0.65:1) has been separated with 99.85% of $O_2$ at the vent of absorption tower, which is 22.7% of the theoretically ideal capacity of the system. This discrepancy results from the reduced contact between the gaseous $SO_2$ and the ionic liquid. Increased $SO_2$ supply, scale-up of the absorption column, and a faster ionic liquid circulation speed were suggested to improve the separation capacity.