• Transactions of the Korean hydrogen and new energy society
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• v.23 no.1
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• pp.56-64
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• 2012

The ITER fuel cycle is designed for DT operation in equimolar ratio. It involves not only a group of fuelling system and torus cryo-pumping system of the exhaust gases through the divertor from the torus in tokamak plant, but also from the exhaust gas processing of the fusion effluent gas mixture connected to the hydrogen isotope separation in cryogenic distillation to the final safe storage & delivery of the hydrogen isotopes in tritium plant. Tritium plant system supplies deuterium and tritium from external sources and treats all tritiated fluids in ITER operation. Every operation and affairs is focused on the tritium inventory accountancy and the confinement. This paper describes the major fuel cycle processes and interfaces in the tritium plant in aspects of upcoming technologies for future hydrogen and/or hydrogen isotope utilization.

• Journal of The Korean Astronomical Society
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• v.36 no.3
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• pp.167-175
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• 2003

There is accumulating evidence for a strong link between nuclear starbursts and AGN. Molecular gas in the central regions of galaxies plays a critical role in fueling nuclear starburst activity and feeding central AGN. The dense molecular ISM is accreted to the nuclear regions by stellar bars and galactic interactions. Here we describe recent observational results for the OB star forming regions in M51 and the nuclear star burst in Arp 220 - both of which have approximately the same rate of star formation per unit mass of ISM. We suggest that the maximum efficiency for forming young stars is an Eddington-like limit imposed by the radiation pressure of newly formed stars acting on the interstellar dust. This limit corresponds to approximately 500 $L_{\bigodot} / M_{\bigodot}$ for optically thick regions in which the radiation has been degraded to the NIR. Interestingly, we note that some of the same considerations can be important in AGN where the source of fuel is provided by stellar evolution mass-loss or ISM accretion. Most of the stellar mass-loss occurs from evolving red giant stars and whether their mass-loss can be accreted to a central AGN or not depends on the radiative opacity of the mass-loss material. The latter depends on whether the dust survives or is sublimated (due to radiative heating). This, in turn, is determined by the AGN luminosity and the distance of the mass-loss stars from the AGN. Several AGN phenomena such as the broad emission and absorption lines may arise in this stellar mass-loss material. The same radiation pressure limit to the accretion may arise if the AGN fuel is from the ISM since the ISM dust-to-gas ratio is the same as that of stellar mass-loss.

• Journal of the Korean Institute of Gas
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• v.13 no.4
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• pp.33-39
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• 2009

This study is intended to experiment performance of pressure relief device and to extend the effective ways to prevent cylinders of NGV from bursting when they are exposed to local fire intensively or when they are overcharged under ambient temperature at fueling stations in summer. In the results of thermal cycling experiments, all products of three companies met the requirements for gas leakage in the qualification criteria between $82^{\circ}C$ and $-40^{\circ}C$. But the o-rings of two companies' specimens among the three companies' specimens got damaged under the accelerated conditions between $135^{\circ}C$ and $-45^{\circ}C$. It took one minute and thirty nine seconds for a glass bulb type of a thermal sensitive type PRD to activate and it took two minutes and thirty one seconds for a fusible plug type of a thermal sensitive type PRD to activate. These results indicated that a glass bulb type of a thermal sensitive type PRD was one minute faster than a fusible plug type of a thermal sensitive type PRD. Under the accelerated condition $135^{\circ}C$, the activation pressure of a pressure sensitive type PRD burst at 32.1 MPa and, under the condition of qualification criteria, it burst from 30.7 MPa to 32.1 MPa.. As a result of the experiment for performance of pressure relief device, in the case of the thermal sensitive type PRD, a glass bulb type is more effective to flame than a fusible plug type. we confirmed that the rupture pressure of a pressure sensitive type PRD could not be affected by temperature and pressure cycling.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.2
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• pp.183-190
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• 2015

An ejector is a type of non-powered pump that is used to supply a secondary flow via the ejection of a primary flow. It is utilized in many industrial fields, and is used for fueling the vehicle because of less failures and simple structure. Since most of ejectors in industry are gas-to-gas and liquid to gas ejector, many research activities have been reported in optimization of gas ejector. On the other hand, the liquid ejector is also applied in many industry but few research has been reported. The liquid ejector occurs cavitation, and it causes damage of parts. Cavitation has bees observed at the nozzle throat at the specified pressure. In this study, a two-dimensional axisymmetric simulation of a liquid-liquid ejector was carried out using five different parameters. The angle of the nozzle plays an important role in the cavitation of a liquid ejector, and the performance characteristics of the flow ratio showed that an angle of $35^{\circ}$ was the most advantageous. The simulation results showed that the performance of the liquid ejector and the cavitation effect have to be considered simultaneously.

• Journal of the Korea Organic Resources Recycling Association
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• v.24 no.4
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• pp.49-57
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• 2016

In this study, a thermal hydrolysis technology was used to treat the poultry carcasses that were killed due to Avian Influenza (AI) occurrence, as well as to determine the possibility of fueling for the resultant products. Experimental results showed that the poultry carcasses were liquefied except for sand, and showed the optimum efficiency at $190^{\circ}C$ and operating time of 60 minutes. It has been shown that liquid products obtained after thermal hydrolysis has good conditions for fuel conversion since it had high carbon contents and calorific value, as well as low ash content. In addition, it was possible to operate the thermal hydrolysis facility by using only the waste heat generated in the combustion without injecting the auxiliary fuel, and the exhaust gas generated in the combustion has a small influence on the atmosphere.