• Journal of Korean Society of Environmental Engineers
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• v.33 no.4
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• pp.237-242
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• 2011

In this study, the catalytic activity of Mn-Phthalocyanine (Mn-PC) for VOCs (acetadehyde, propionaldehyde and toluene) combustion was determined. The reaction was carried out in a fixed bed reactor at the temperature range of $200{\sim}380^{\circ}C$. We investigated the physicochemical properties of Mn-PC before and after the pretreatment (air, $450^{\circ}C$, 1 hr, 60 cc/min) by TGA (Thermogravimetric Analyzer), BET (Brunauer Emmett Teller), EA (Elemental Analyzer), XRD (X-ray Diffractometer) and SEM (Scanning Electronic Microscope). By TGA analysis, 88 wt.% mass loss of Mn-PC was found at $419^{\circ}C$. The BET surface area of Mn-PC increased after the pretreatment. The decomposition and combustion of organic components in Mn-PC were observed by EA analysis. We also confirmed that Mn-PC had transformed into a new manganese oxide phase ($Mn_3O_4$) after the pretreatment by XRD analysis. By SEM analysis, many of the micropores generated during the pretreatment were found. The catalytic activity of Mn-PC with the pretreatment for propionaldehyde combustion was higher than that of $Mn_3O_4$ and fresh Mn-PC. It showed the catalytic activity of Mn-PC with the pretreatment for VOCs combustion by the order of toluene < acetadehyde < propionaldehyde.

• Magazine of the Korea Concrete Institute
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• v.20 no.1
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• pp.34-40
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• 2008

• International Journal of Concrete Structures and Materials
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• v.10 no.4
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• pp.539-553
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• 2016

Polymer concrete (PC) has been favoured over Portland cement concrete when low permeability, high adhesion, and/or high durability against aggressive environments are required. In this research, a new class of PC incorporating Multi-Walled Carbon Nanotubes (MWCNTs) is introduced. Four PC mixes with different MWCNTs contents were examined. MWCNTs were carefully dispersed in epoxy resin and then mixed with the hardener and aggregate to produce PC. The impact strength of the new PC was investigated by performing low-velocity impact tests. Other mechanical properties of the new PC including compressive, flexural, and shear strengths were also characterized. Moreover, microstructural characterization using scanning electron microscope and Fourier transform infrared spectroscopy of PC incorporating MWCNTs was performed. Impact test results showed that energy absorption of PC with 1.0 wt% MWCNTs by weight of epoxy resin was significantly improved by 36 % compared with conventional PC. Microstructural analysis demonstrated evidence that MWCNTs significantly altered the chemical structure of epoxy matrix. The changes in the microstructure lead to improvements in the impact resistance of PC, which would benefit the design of various PC structural elements.

• Macromolecular Research
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• v.14 no.1
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• pp.38-44
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• 2006

Vacuum deposited copper phthalocyanine (CuPc) was placed as a thin interlayer between indium tin oxide (ITO) electrode and a hole transporting layer (HTL) in a multi-layered, organic, light-emitting diode (OLEOs). The well-stacked CuPc layer increased the stability and efficiency of the devices. Thermal annealing after CuPc deposition and magnetic field treatment during CuPc deposition were performed to obtain a stacked-CuPc layer; the former increased the stacking density of the CuPc molecules and the alignment of the CuPc film. Thermal annealing at about 100$^{circ}C$ increased the current flow through the CuPc layer by over 25$\%$. Surface roughness decreased from 4.12 to 3.65 nm and spikes were lowered at the film surface as well. However, magnetic field treatment during deposition was less effective than thermal treatment. Eventually, a higher luminescence at a given voltage was obtained when a thermally-annealed CuPc layer was placed in the present, multi-layered, ITO/CuPc/NPD/Alq3/LiF/AI devices. Thermal annealing at about 100$^{circ}C$ for 3 h produced the most efficient, multi-layered EL devices in the present study.

• Journal of Gastric Cancer
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• v.10 no.3
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• pp.126-132
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• 2010

Purpose: Peritoneal carcinomatosis (PC) has a dismal prognosis and is occasionally encountered during initial exploration in patients with gastric cancer. The clinicopathological characteristics and survival were analyzed in patients with gastric cancer and PC. Materials and Methods: Among 2,083 gastric cancer patients who received surgery at the department of surgery, Hanyang University Hospital from 1992 to 2009, 130 patients revealed PC. Ten patients who were lost during follow-up were excluded. The remaining 120 patients were divided into three groups according to the type of surgery. The degree of PC was classified into P1(to the adjacent peritoneum) and P2 (to the distant peritoneum). Various other clinicopathological factors were analyzed using univariate and multivariatec survival analyses. Results: Systemic chemotherapy (SC), type of surgery, lymph node dissection, degree of PC, and presence of ascites were significant prognostic factors. However, age, gender, resection of PC, and Borrmann type were not significant prognostic factors. In a multivariate analysis, SC and the degree of PC were independent prognostic factors. The survival benefit of SC was significant without reference to the type of surgery or degree of PC. Conclusions: A gastrectomy should be considered feasible in patients with gastric cancer and PC. The independent favorable prognostic factors were SC and a low degree of PC. SC improved the prognosis regardless of operation type and degree of PC.

• Journal of Information Processing Systems
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• v.1 no.1 s.1
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• pp.62-69
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• 2005

This paper presents a queuing analysis model of a PC-based software router supporting IPv6-IPv4 translation for residential gateway. The proposed models are M/G/1/K or MMPP-2/G/1/K by arrival process of the software PC router. M/G/1/K is a model of normal traffic and MMPP-2/G/1/K is a model of burst traffic. In M/G/1/K, the arriving process is assumed to be a Poisson process, which is independent and identically distributed. In MMPP-2/G/1/K, the arriving process is assumed to be two-state Markov Modulated Poisson Process (MMPP) which is changed from one state to another state with intensity. The service time distribution is general distribution and the service discipline of the server is processor sharing. Also, the total number of packets that can be processed at one time is limited to K. We obtain performance metrics of PC-based software router for residential gateway such as system sojourn time blocking probability and throughput based on the proposed model. Compared to other models, our model is simpler and it is easier to estimate model parameters. Validation results show that the model estimates the performance of the target system.

• Computational Structural Engineering
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• v.1 no.2
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• pp.18-25
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• 1988

1981년 여름 대형컴퓨터의 대부로서 군림해온 IBM이 PC를 발표함과 더불어 그들의 기술을 공개함으로써 많은 회사들이 IBM PC 호환기종을 개발, 생산할 수 있었고 특히 표준 OS인 MS-DOS와 더불어 PC의 표준화를 유도함으로써 많은 주변기기 및 소프트웨어 등장이 가능했고 최근에는 반도체의 급속한 기술발달로 고집적 메모리의 값싼 공급과 16비트 및 32비트 마이크로프로세서의 등장으로 PC도 그 기능이 점차 확대되어 개인 오락기나 간단한 OA차원을 벗어나 이제는 엔지니어링 분야에까지 그 영역을 넓혀가고 있다. 그러나 아직 국내에 보급된 PC로는 3차원 구조계산과 같은 복잡한 엔지니어링 업무를 수행하기에는 많은 제약조건이 있으나 80386의 보급이 확대되고 80486의 발표가 눈앞에 와 있는 싯점에 PC의 성능은 놀라울 정도로 향상될 것이고 엔지니어링 분야에도 크게 기여할 것으로 믿는다. PC를 이루는 많은 하드웨어 중에서 엔지니어링 분야 이용자에게 특히 필요한 부분을 먼저 간단히 소개하고 다음에 이의 활용을 소개함으로써 엔지니어링 분야의 프로그램 개발자나 이용자가 보다 능동적으로 PC를 선정하고 나아가 기능확대, 성능향상을 꾀하는데 도움을 주고자 한다.

• Polymer(Korea)
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• v.32 no.5
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• pp.483-488
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• 2008

The effect of methylene chloride/1,3-dioxolane co-solvent on the crystallization in the optical polycarbonate film was investigated. Increasing 1,3-dioxolane content in co-solvent resulted in the crystallization due to the lowering of solvent evaporation rate during film drying process. The crystallization in PC film could be minimized by either controlling of solvent composition and increasing solvent drying temperature. It was found that the surface roughness of solution casting PC film was affected by both crystallization and solvent evaporation rate. This morphological effect by alternative solvent is ascribed to a large decrease in light transmissivity on the optical PC film.

• Journal of Astronomy and Space Sciences
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• v.29 no.3
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• pp.259-267
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• 2012

Polar cap potential has long been considered as an indicator for the amount of energy flowing in the magnetosphere-ionosphere system. Thus, the estimation of polar cap potential is important to understand the physical process of the magnetosphere. To estimate the polar cap potential in the Northern Hemisphere, merging electric field by Kan & Lee (1979) is adopted. Relationships between the PC index and calculated merging electric field ($E^*$) are examined during full-time and storm-time periods separately. For this purpose Dst, AL, and PC indices and solar wind data are utilized during the period from 1996-2003. From this linear relationship, polar cap potential (${\Phi}^*$) is estimated using the formula by Doyle & Burke (1983). The values are represented as $58.1{\pm}26.9$ kV for the full-time period and $123.7{\pm}84.1$ kV for a storm-time period separately. Considering that the average value of polar cap potential of Doyle & Burke (1983) is about 47 kV during moderately quiet intervals with the S3-2 measurements, these results are similar to such. The monthly averaged variation of Dst, AL, and PC indices are then compared. The Dst and AL indices show distinct characteristics with peaks during equinoctial season whereas the average PC index according to the month shows higher values in autumn than in spring. The monthly variations of the linear correlation coefficients between solar wind parameters and geomagnetic indices are also examined. The PC-AL linear correlation coefficient is highest, being 0.82 with peaks during the equinoctial season. As with the AL index, the PC index may also prove useful for predicting the intensity of an auroral substorm. Generally, the linear correlation coefficients are shown low in summer due to conductance differences and other factors. To assess the role of the PC index during the recovery phase of a storm, the relation between the cumulative PC index and the duration is examined. Although the correlation coefficient lowers with the storm size, it is clear that the average correlation coefficient is high. There is a tendency that duration of the recovery phase is longer as the PC index increases.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.37-40
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• 2008

Recently, Construction Business, is changing very quickly, exceedingly needs to slim down the construction expensive by reducing material costs and the term of works. The term of formwork takes 25% of the term of works and costs 15% to 20% of the cost of construction. Hereupon, the purpose of this study is to investigate the Axial Strength of Centrifugall Formed Shell PC Columns that can reduce the term of formwork, the costs of material, the difficulty of throwing away the waste. Shell PC Column is loaded stirrups and manufactured at factory, so it has good points like construction's quality control and part's precision. However, it needs to be tested for checking bonded ability because it is set up at core and coverd with concrete. therefore this study is necessary three type of columns, which are a RC column, different type of two compressive strength core concrete columns and a Shell PC Column. By three columns, this study compare with and analysis three columns's bonded and Compressive Behavior abilities.