• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.1167-1174
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• 2008

Vertical drain method, which is one of the soft ground improvement methods, shorten s drain path to accelerate consolidation process and is applied in many sites. At a recent, composite discharge capacity experiment that analyze discharge amount by consolidation behavior with overburden pressure of soft ground in laboratory, simulates similarly with actuality. Geotechnical engineering problems such a s soft ground improvement are solved by numerical analysis by development of computer and numerical analysis techniques. Numerical analysis does that result is contrary by user's inexperience for choice of constitution model and application of analysis method. Therefore, this thesis experiments on composite discharge capacity test and study discharge capacity of drain and consolidation behavior of soft ground installed prefabricated vertical drain boards. Also, This thesis studied reasonable input parameters and constitution model by compare results of composite discharge capacity test and numerical analysis using PLAXIS that is 2D finial element numerical analysis program.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.11
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• pp.1224-1229
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• 2004

The purpose of this study is to research and develop tin oxide-flyash composite for lithium Ion polymer battery. Tin oxide is one of the promising material as a electrode active material for lithium Ion polymer battery (LIPB). Tin-based oxides have theoretical volumetric and gravimetric capacities that are four and two times that of carbon, respectively. We investigated cyclic voltammetry, AC impedance and charge/discharge cycling of SnO$_2$-flyash/SPE/Li cells. The first discharge capacity of SnO$_2$-flyash composite anode was 639 mAh/g. The discharge capacity of SnO$_2$-flyash composite anode was 563 and 472 mAh/g at 6th and 15th cycle, respectively. The SnO$_2$-flyash composite anode with PVDF-PMMA-PC-EC-LiClO$_4$ electrolyte showed good capacity with cycling.

• Journal of the Korean Geosynthetics Society
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• v.4 no.1
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• pp.27-36
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• 2005

Discharge capacity of the fiber mat and the fiber drain made with natural fibers abstracted from plant source was evaluated by permeability test for fiber mat and Delft type test and composite discharge capacity test using disturbed clayey soils for fiber drain. The permeability test results for environmentally friendly coconut fiber mat prove that fiber mat has outstanding permeability in substituting permeable sand. However, discharge capacity of fiber drain evaluated by conventional Delft type discharge capacity test was relatively lower than that of plastic drain board. Nevertheless, settlement and pore pressure dissipation behaviors of fiber drain and plastic drain board installed clay soil during the composite discharge capacity test were almost similar to that of plastic drain board. It is found that the natural fiber drain satisfies requiring minimum discharge capacity in substituting the conventional plastic drain board.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.03a
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• pp.293-299
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• 2008

If a conventional type of Plastic Board Drain (PBD) is installed to the deep clay deposit, it is subjected to a high lateral earth pressure. a flow channel of PBD may be reduced by the collapse of cores and clogged by the intrusion of filter into the space between cores which are made by lateral pressure. It could decrease the ability of initial discharge capacity and the reliability of long term discharge capacity. A cylindrical plastic board drain (C-PBD) considered in this study consists of cylindrical core and several supports so that it can prevent the reduction of area of flow channel from the higher lateral earth pressure effectively. The discharge capacity of C-PBD was compared to that of a conventional PBD through performing experiments using the composite discharge capacity apparatus which can consider in-situ condition such as penetration of drains, ground settlement and discharge capacity. As a result, C-PBD showed much better performance than PBD in the ability of discharge. It was observed that the C-PBD was folded whereas the conventional PBD was folded after the experiment.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.05c
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• pp.88-90
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• 2003

The purpose of this study is to research and develop tin oxide-flash composite for lithium Ion polymer battery. Tin oxide is one of the promising material as a electrode active material for lithium Ion polymer battery (LIPB). Tin-based oxides have theoretical volumetric and gravimetric capacities that are four and two times that of carbon, respectively. We investigated cyclic voltammetry and charge/discharge cycling of SnO-flyash/SPE/Li cells. The first discharge capacity of SnO-flyash composite anode was 720 mAh/g. The discharge capacity of SnO-flyash composite anode 412 and 314 mAh/g at cycle 2 and 10 at room temperature, respectively. The SnO-flyash composite anode with PVDF-PMMA-PC-EC-$LiClO_4$ electrolyte showed good capacity with cycling.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.11a
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• pp.359-362
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• 2000

The purpose of this study is to research and develop graphene composite for lithium polymer battery. VO(graphene) composite is one of the promising material as a electrode active material for lithium polymer battery(LPB). We investigated AC impedance response and charge/discharge cycling of VO(graphene)/SPE/Li cells. The first discharge capacity of VO(graphene) cathode with 50wt.% V$_2$O$\sub$5/ was 150mAh/g, while that of VO(graphene) cathode with 85wt.% V$_2$O$\sub$5/ was 248mAh/g. The Ah efficiency was above 98% after the 2nd cycle. The discharge capacity of VO(graphene) anode with 3wt.% V$_2$O$\sub$5/ was 718 and 266mAh/g at cycle 1 and 10 at room temperature, respectively. The VO(graphene) anode with 3wt.% V$_2$O$\sub$5/ in PVDF-PAN-PC-EC-LiC1O$_4$ electrolyte showed good capacity with cycling.

• Journal of the Korean Geosynthetics Society
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• v.11 no.1
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• pp.47-56
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• 2012

Discharge capacity of PBD is sensitive in proportion to thickness and ground condition, and drainage of PBD declines due to disturbance effect in surrounding ground by mandrel used for vertical drainage setting and setting machines and type. Also, deviation of discharge capacity gets larger according to ground condition, construction condition and soil properties. But cause and analysis of those problems like reduced discharge of capacity and delayed dissipation of pore water pressure for discharge capacity is lack. Thus, in this text, ground improvement and discharge capacity is investigated by implementing composite discharge capacity test for analysis of an effect factor of PBD discharge capacity with in-situ ground condition. After fixing the vertical drain on a cylindrical cylinder, put churned sample into the cylinder. After in-situ ground and reclamation of ground are dredged, load following the loading step of 30, 70 and 120kPa using a pressure device. Result of the test, The discharge capacity was SM>ML>CL>CL(dredged soil) in situ condition and more fine-grained content, the amount of discharge was greater.

• Journal of Power System Engineering
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• v.17 no.1
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• pp.110-115
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• 2013

The electrochemical performance and microstructure of Al-Si, Al-Si/C was investigated as anode for lithium ion battery. The Al-Si nano composite with 5 : 1 at% ratio was prepared by arc-discharge nano powder process. However, some of problem is occurred, when Al nano composite was synthesized by this manufacturing. The oxidation film is generated around Al-Si particles for passivating processing in the manufacture. The oxidation film interrupts electrical chemistry reaction during lithium ion insertion/extraction for charge and discharge. Because of the existence the oxidation film, Al-Si first cycle capacity is very lower than other examples. Therefore, carbon synthsized by glucose ($C_6H_{12}O_6$) was conducted to remove the oxidation film covered on the composite. The results showed that the first discharge cycle capacity of Al-Si/C is improved to 113mAh/g comparing with Al-Si (18.6mAh/g). Furthermore, XRD data and TEM images indicate that $Al_4C_3$ crystalline exist in Al-Si/C composite. In addition the Si-Al anode material, in which silicon is more contained was tested by same method as above, it was investigated to check the anode capacity and morphology properties in accordance with changing content of silicon, Si-Al anode has much higher initial discharge capacity(about 500mAh/g) than anode materials based on Aluminum as well as the morphology properties is also very different with the anode based Aluminum.

• Journal of the Korean GEO-environmental Society
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• v.12 no.12
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• pp.37-46
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• 2011

An application frequency of vertical drainage method is increasing as an effective consolidation acceleration method. PBD method is most frequently used as a consolidation acceleration method in vertical drainage methods. PBD is economical and easy to operate but has some problems those are an environmental pollution and a decrease of a discharge capacity caused by bending of drainage materials when it is used in great depth. SCP method was frequently used because it's discharge capacity was good but now it is rarely used because of an increase of the material price because of an order imbalance. As the way to solve these problems, GCP method has been to the fore. For analyzing the effect of GCP method on the discharge capacity, three types of composite discharge capacity tests are done by using GCP, SCP and PBD respectively with the circle case, ${\phi}38{\times}h70cm$. On the contrary to this, GCP shows the worst discharge capacity for a decrease of the void ratio and the clogging phenomenon caused by increasing load. Also to figure out the clogging range of GCP, the clogging of GCP is checked in each load stage with a large case($1.0m{\times}0.5m{\times}1.1m$) which has clear acrylic front face. The diameter of GCP was 35cm and a clogging phenomenon occurred in 10% approximately. The result shows that the discharge capacity of GCP was given the lowest value for a decrease of the void ratio and the clogging phenomenon causing by increasing load. And the clogging phenomenon mostly occurred within 10% of GCP's diameter range.

• Proceedings of the KIEE Conference
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• 1996.07c
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• pp.1414-1417
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• 1996

The purpose of this study Is to research and develop $V_{6}O_{13}$ composite cathode for lithium thin film battery. $V_{6}O_{13}$ represents a class of cathode active material used in Li rechargeable batteries. In this study, we investigated cyclic voltammetry and charge/discharge characteristics of $V_6O_{13}$/SPE/Li cells. Cyclic voltammogram of $V_{6}O_{13}$/SPE/Li cell at scan rate 1mV/sec showed reduction peaks of 2.25V and 2.4V and oxidation peaks of 2.4V and 2.2V. The discharge curve of $V_{6}O_{13}$/SPE/Li cell showed 4 potential plateaus. The discharge capacity was decreased in the beginning of charge/discharge cycling. After 8th cycling, the discharge capacity was stable. The discharge capacity of 1st cycle and 15th cycle was 290mAh/g and 147mAh/g at $25^{\circ}C$, respectively.