• Applied Chemistry for Engineering
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• v.9 no.7
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• pp.1059-1064
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• 1998

We have investigated various kind of graphite and MCMB6-28 to develop carbon negative electrode for lithium ion secondary battery. The interlayer length of them was $3.358{\sim}3.363{\AA}$ and the BET specific surface area was $2.95{\sim}26.15m^2/g$. From this study, When the interlayer of them was large and the BET specific surface area was high, the electrochemical characteristics of them was very excellent. Adding 0, 3, 5, wt% of KJ-Black as conducting agent to various graphitic carbon active materials, interface resistance of electrode and electrolyte was less, but rechargeability was better at 3 wt%. At constant current charge and discharge test, discharge capacity was small according to large current.

• Fire Science and Engineering
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• v.24 no.5
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• pp.150-158
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• 2010

There are lots of buildings with their deterioration in wholesale markets which have high concentration that can cause big fire due to difficulty of installing fire protection system in fire compartment, absence of safety awareness, access by many and unspecified people. There had been big fire that caused by these kind of fire weakness such as Seomun Market's in 2005 which costed tens of millions dollar, Dongmun Shopping District’s with 7 casualties. Now counter-measure against these fire is urgently needed. This study drew characteristic of current condition of wholesale markets and the one classified by main agent, fire cases and prevention of fire through statistical data. Also, current condition of fire prevention management and actual state were investigated by conducting a survey of person in charge of fire prevention and current practician. As a result, it was shown that securing professionalism of fire prevention, improvement of structural weakness of buildings, obtaining reliability on performance of fire protection system and internal fire education against practician in the market are needed.

• Polymer(Korea)
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• v.24 no.1
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• pp.133-139
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• 2000

Poly(ethylene glycol) with number-average molecular weight (M$_{n}$) of 200 (PEG 200) or 400 (PEG 400) was reacted with various linking agents (CH$_2$Cl$_2$, CH$_2$Br$_2$, CH$_2$I$_2$, Br(CH$_2$)$_3$Br) in the presence of alkali to form of oxyalkylene linked chains. Molecular weights of copolymers were controlled using feed mole ratio of alkali/CH$_2$C1$_2$/PEG. The M$_{n}$ of the polymers measured by end group analysis and that measured by GPC agreed well. Molecuglar weights of polyether copolymers obtained from PEG 200 and PEG 400 were about 500~8500 and 1000~2000, respectively. Polyether copolymers prepared from PEG 400 showed melting points of around 1$0^{\circ}C$. Glass transition temperatures of the copolymers were around -75$^{\circ}C$ and the crystallinity was about 0~25%. The polyether copolymers prepared from PEG 200 had no crystallinity below the M$_{n}$ of 2500. 2500.

• The Korean Journal of Pain
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• v.12 no.1
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• pp.64-69
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• 1999

Background: The new drug HP228 is a cytokine restraining agent with a broad spectrum of anti-inflammatory, analgesic, and antipyretic activity. Six healthy, adult, male volunteers were studied to determine the independent and interactive effects of HP228 and morphine on pain perception. Methods: Two groups of stimuli were applied to each volunteers before drug administration as control, 20 min after morphine and HP228 administration, and 20 min after combined administration of these two drugs. Two adhesive electrically-conducting pads were applied on opposite sides of the arm approximately 8 cm apart. The electrode were connected to an electrical impulse generator and 50 Hz 1 msec pulses of incrementally increasing intensity were delivered at 1 sec intervals. The analgesic endpoints were the current intensity (mA) at which the subject first detected the stimulus (THRESH), the intensity at which the stimulus was first idenfied as being painful (PAIN), and the intensity at which the subject requested that the stimulus be terminated due to discomfort (LIMIT). A second series of stimuli were applied immediately thereafter using 1-sec duration 50 Hz tetanus pulses with increasing intensities at 2~5 sec intervals. Results: There were significant differences between drug treatments (Morphine, HP228, HP228/Morphine) and control (No drugs) in any of the measurements (PAIN, LIMIT) except THRESH with the twitch and tetanus test. Conclusions: The data suggests that HP228 is an analgesic, but it does not appear to interact with morphine in an additive manner.

• Transactions of the Korean hydrogen and new energy society
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• v.22 no.1
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• pp.83-91
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• 2011

We investigated the effect of composition of a sulfur electrode with MWNT on the discharge behavior and cycling property of a Li/S cell. The MWNT content of a 60wt.% sulfur electrode varied from 10 wt.% to 30 wt.%. The optimum content of MWNT is 20wt.%, which shows the best cycling property. The first discharge capacity is 1166 mAh/g and decrease to the 542 mAh/g after 30th cycle. The homogeneous distribution of MWNT is an important factor for cycling properties.

• Transactions of the Korean hydrogen and new energy society
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• v.22 no.1
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• pp.42-50
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• 2011

The Montmorillonite (MMT) in the polymer matrix is expected to reduce methanol permeability due to the tortous path formed by dispersed silicate layers. However, the polymer composite membranes containing non-proton conducting inorganic particle tend to show low proton conductivity. To solve this problem, we used an ion exchange method to prepare functionalized MMT with various silane coupling agents. The modified MMT was randomly dispersed in sulfonated poly (arylene ether sulfone) (SPAES) matrix to prepare SPAES/modified MMT composite membranes. The performances of hybrid membranes for DMFCs application were investigated. The SPAES/modified composite membrane showed increased proton conductivity compared with the non-modified MMT composite membrane. However, the methanol permeability of the SPAES/modified membrane was higher than that of the non-modified MMT.

• Journal of the Korean Electrochemical Society
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• v.3 no.3
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• pp.141-145
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• 2000

Anodically Polymerized conducting Polypyrrole film electrode was employed to Pick up uranyl ion with the type of Gr/ppy, xylenol orange modified electrode. To have Porous and oriented ppy film, NBR was applied as precoating agent. The rate constant of polymerization was $3.22\times10^{-3}s^{-1}$ which was 1.6 times smaller value than bare graphite surface. The deposited amount of uranyl iou on $1.70Ccm^{-2}$ of ppy was $1.55\times10^{-4}g$. The matrix effect in artificial seawater was $6.8\%$. The polymer film electrode has a diffusion controlled process in conduction, but the modified Gr/ppy, $X.O^{4-}UO^+$ type was influenced on the ion doping and electronic conduction of film itself owing to increasing of impedance. The capacitance of electrical double layer was respectively enhanced to 56 and 130 times in Gr/ppy, $X.O.^{4-}$ and Gr/ppy, $X.O^{4-}UO^+$ than Grippy type electrode.

• Journal of the Korea Institute of Building Construction
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• v.9 no.2
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• pp.77-83
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• 2009

In this study, a test has been carried out to solve the problem with ground granulated blast-furnace slag, low early strength & lack of supply and to find out a way to use as concrete admixture of the ultrafine blaine air cooling slag which is all disposed as the by product of air cooling slag and its test was conducted to the replacement rate of ultrafine blaine air cooling slag & mixing condition of every concrete admixtures by type for the purpose of obtaining later a basic data for practical use of the cement that used ultrafine blaine air cooling slag by conducting comparative analysis. If ultrafine-blaine air cooling slag is used to the concrete following the results, a high efficiency water reducing agent won't be needed much for flow acquisition due to a high increase in flow, and the stripping time of concrete form will be shortened thanks to the acquisition of early strength, And though, it has the problems with long term strength which is similar or a little lower than the 3 types of ground granulated blast-furnace slag, it's still applicable as the substitute materials for 3 types of ground granulated blast-furnace slag at 10, 15% replacement rate of ultrafine-blaine air cooling slag, at which it shows higher activation index than 3 types of ground granulated blast-furnace slag.

• The Journal of Information Systems
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• v.19 no.2
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• pp.37-71
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• 2010

This article identifies factors affecting successful ERP systems by focusing on the stages after stabilizing ERP systems and overcoming temporary performance dip by introduction of ERP systems, and suggests change management tactics to control those identified factors. We can not expect that every users are familiar with the usage of an ERP system even after they are informed about the expected advantage of the newly implemented ERP system and trained intensively for changed business process and system usage while implementing a new ERP system. Moreover, even after more than six months usage of the system, the users may still have some trouble due to the reason why they have insufficient information about the expected advantage of the system (recognition gap) and insufficient knowledge about the changed usage of the system (knowledge gap). Hence, this article diagnoses by conducting a case study that those recognition and knowledge gap would have a severe bad influence upon the users' trust and satisfaction on ERP systems. This article suggests an appropriate change management tactics to overcome those recognition and knowledge gap by considering the relationship with the efforts for change management before, during, and after the introduction of ERP systems and performing an in-depth analysis on the users' dissatisfaction and request for update during the stages after the stabilization of the ERP systems. This article also shows a corroborative evidence that these efforts of change management consequently contributes to the solution of users' distrust and dissatisfaction. In sum, this article identifies the factors influencing badly on the magnitude and seriousness of knowledge and recognition gap, and suggests a conceptual research model which says that the satisfaction of ERP users could be uplifted by the solution of their knowledge and recognition gap if we keep making efforts on appropriate change management considering those identified factors during the stages after the stabilization of an ERP system.

• Carbon letters
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• v.8 no.3
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• pp.184-190
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• 2007

Carbon Nano Tubes could be either metallic or semi-conducting in nature, depending on their diameter. Its photocatalytic behavior has given an impetus to use it as an anti-microbial agent. More than 95% Escherichia coli and Staphylococcus aureus bacteria got killed when exposed to Carbon Nano Tubes for 30 minutes in presence of sunlight. Carbon Nano Tubes are supposed to have smooth surface on to which it accumulates positive charges when exposed to light. The surface that is non illuminated has negative charge. At the cellular level microorganisms produce negative charges on the cell membrane, Therefore damaging effect of multi walled carbon nano tubes (exposed to light) on the microorganisms is possible. In this paper, photo catalytic killing of microbes by multi walled carbon nano tubes is reported. Killing was due to damage in the cell membrane, as seen in SEM micrographs. Moreover biochemical analysis of membrane as well as total cellular proteins by SDS PAGE showed that there was denaturation of membrane proteins as well as total proteins of both the microbes studied. The killed microbes that showed a decrease in number of protein bands (i.e. due to breaking down of proteins) also showed an increase in level of free amino acids in microbes. This further confirmed that proteins got denatured or broken down into shorter units of amino acids. Increased level of free amino acids was recorded in both the microbes treated with multi walled carbon nano tubes and sunlight.