• Solar Energy
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• v.19 no.4
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• pp.11-20
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• 1999

The study on ice thermal storage system is to improve total system performance and increase the economical efficiency in actual air-conditioning facilities. To obtain the high charging and discharging efficiencies in ice thermal storage system, the improvement of thermal stratification is essential, therefore the process flow must be piston flow in the cylindrical type. In the influence of the inlet port type, the inflowing water in the distributor type diffuses through the whole storage tank more than in the slot type. In case of the flow process in the ice storage tank, the upward flow type in the charging process and the downward flow type in the discharging process make the stratification well, thereby the loss of energy wored be smaller. The influence of the inlet temperature difference and the change of the inlet flow rate is intensive when the temperature difference is larger, the flow rate is smaller in case of charging and the results are opposite in case of discharging with the reason that the good coduction condition. The total effeciency of the ice thermal storge system is 73% on condition that the porosity in the thermal storage tank is 0.55. This result shows that cylinderical ice storage tank has better storage capacity than rectangular type in case of the same porosity.

• Resources Recycling
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• v.16 no.4
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• pp.3-9
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• 2007

Dismantlement of lithium primary batteries without explosion is required to recycle the lithium primary batteries which could be exploded by heating too much or crushing. In the present study, the optimum discharging condition was investigated to dismantle the batteries without explosion. When the batteries were discharged with $0.5kmol{\cdot}m^{-3}$ sulfuric acid, the batteries became inert after 4 days at $35^{\circ}C$ and after 1 day at $50^{\circ}C$, respectively. This result shows that higher temperature accelerates inert of the batteries. Because loss of metals recycled increases when the batteries are discharged only with the sulfuric acid, discharging process using acid solution and water was newly proposed. When the batteries were discharged with water during 24 hours after discharging with $0.5kmol{\cdot}m^{-3}$ sulfuric acid during 6 hours, the batteries discharged were dismantled without explosion. Because decrease in loss of metals was accomplished by new process, the recycling process of the batteries could become economic by the 2-step discharging process.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.1083-1087
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• 1996

Bore evacuator which have circular structure of cylindrical form is located at tube, and its function is to evacuate toxic gases generated during firing intervals. Between bore evacuator and bore interior, gas flow field is developed through the nozzles, and the charging and discharging process is formed. By these flow cycle(charging and discharging) the evacuation effect can be generated. This report contains an analyses and results consideration about bore evacuator flowfield.

• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.602-606
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• 2006

The electrostatic is well known phenomena. The fires and explosions caused by electrostatic occur often in the coating mechanical system. This paper presents various cases of electrostatic hazards, reasons why electrostatic hazards are happened, and methods for preventing electrostatic hazards. Generally the electrostatic can be lead to corona discharging, streaming electrification, and impinging electrification in the coating process. Corona discharging happens at electrostatic spray gun with 70 kV. Streaming electrification occurs at mixing process between paint and thinner, and transportation process with thinner. Impinging electrification is shown when the thinner are sprayed to drums. For the purpose of preventing the electrostatic discharge and damage, conductors should be ground, surface electric potential of should be decreased in using electrostatic shielding and ground, and flow of thinner should be controlled acceptable velocity.

• Transactions on Electrical and Electronic Materials
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• v.14 no.1
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• pp.36-38
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• 2013

Eight sample panels using an indium tin oxide(ITO)-coated glass substrate were fabricated, with barrier ribs formed of 55 ${\mu}m$ height and 10 ${\mu}m$ width. The upper and lower substrates were designed with the same panel condition, so a cell gap of 110 ${\mu}m$ was obtained. The charged particles in a cell consisted of $TiO_2$ (for white color) or carbon black (black color), negative or positive charge control agents, and a polymer. The average diameter of the two types of particles was commonly 10 ${\mu}m$, and their q/m value was -4.5 ${\mu}C/g$ and +4.5 ${\mu}C/g$, respectively. The electrically opposite particles mixed by an agitator were loaded into their cells by a simple particle-loading method. The discharging process proceeded at a humidity of 80% and a temperature of $30^{\circ}C$. Reflectivity was measured depending on discharging time, and a hysteresis curve by bias voltage obtained for comparison between the neutralized and non-neutralized panel, in which the superior optical property of the neutralized panel was ascertained.

• Journal of the Korean Society for Precision Engineering
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• v.12 no.11
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• pp.125-131
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• 1995

Pneumatic System has been mainly used as main equipment for actuation and control of fluid force in manufacturing industry. For velocity control of piston, meter-out restriction method is used in many cases. In this systems, meter-out restriction method is adopted for analysing the Dynamic Charging and Discharging Process which is Variable Volume Chamber. Experiments has been conducted for different supply pressure condition. As a experimental result, charge side chamber pressure rises to supply pressure rapidily and discharge side chamber pressure decreases. Also, when the air in the cylinder is discharged, tempdrature of air decreases steeply. Restriction of the Cylinder sometimes freeze and it dose not function. The result will be useful for the analysis of pneumatic system.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.2
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• pp.40-46
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• 2012

In this study, numerical analysis was conducted to understand the flow characteristics of lubrication system in a manual transmission installed in a commercial vehicle. Also, the analysis was conducted with the purpose of improving the heat and lubricative condition of the transmission. Discharging flow rates on each oil hole outlet according to various engine rotating speed and the length of oil hole branch was calculated. In conclusion, as engine rotating speed is high and the length of oil hole branch is long, the discharging flow rate is high by virtue of the centrifugal force. In addition, this study proposed data for optimal design of lubrication system in manual transmission for a commercial vehicle.

• The Transactions of the Korean Institute of Power Electronics
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• v.15 no.6
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• pp.441-450
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• 2010

Lithium battery is widely used as the power source of various electronic devices. The formation process which is the repeated charging and discharging process is essential in the production of lithium battery. In this paper, it is proposed and designed the DC-DC converter that can charge and also discharge the lithium battery in one converter. The proposed converter is designed by considering the charge/discharge characteristics of the lithium battery. The converter is operated as a forward converter in charging process and a electrically isolated boost converter in discharging process. Based on the analyses, the number of transformer turns, inductor, capacitor, and switching devices are designed. Finally, the validity of the design for the proposed converter is verified by both simulations and experiments.

• Journal of the Korean Ceramic Society
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• v.42 no.7 s.278
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• pp.503-508
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• 2005

A simple and effective method for the synthesis of LiMn$_{2}$O$_{4}$ powder as a cathode material for lithium secondary battery is reported. Micrometer size LiMn$_{2}$O$_{4}$ was prepared by combustion synthesis technique employing initial mixture of l.l LiNO$_{3}$ -1.3Mn-0.7MnO$_{2}$-1NaCl composition. Parametric study of the combustion process including molar ratio of Mn/MnO$_{2}$ and NaCl concentration were carried out under air atmosphere. The combustion products obtained were additionally heat treated at the temperature 900$^{\circ}C$ and the washed by distilled water. The results of charging-discharging characteristics revealed that LiMn$_{2}$O$_{4}$ cell synthesized in the presence of NaCl had a high capacity and much better reversibility than one formed without NaCl An approximate chemical mechanism for LiMn$_{2}$O$_{4}$ formation is proposed.

• Journal of the Korean Electrochemical Society
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• v.1 no.1
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• pp.8-13
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• 1998

This work presents the way how to evaluate the degree of reversibility of the discharging process undergone by the nickel hydroxide film cathodically deposited on pure nickel as a positive electrode for electrochemical capacitor using the combined cyclic voltammetry and potential drop method, supplemented by galvanostatic discharge and open-circuit potential transient methods. The time interval necessary just to establish the current reversal of anodic to cathodic direction from the moment just after applying the potential inversion of anodic to cathodic direction, was obtained on cyclic voltammogram. The cathodic charge density passed upon dropping the applied potential, was calculated on potentiostatic current density-time curve. Both the time interval and the cathodic charge density in magnitude can be regarded as being measures of the degree of reversibility of the discharging process undergone by the positive active material for supercapacitor, i.e. , the longer the time interval is, the lower is the degree of reversibility and the greater the cathodic charge density is, the higher is the degree of reversibility. From the applied potential dependences of the time interval and cathodic charge density, discharge at $0.42 V_{SCE}$ was determined to be the most reversible.