최근 정부에서는 전자적 대금지급시스템을 고도화하여 건설 현장에서 체불을 해결하고 양질의 일자리를 창출하고자 방안을 모색하고 있다. 그러나 아직까지 논의 되고 있는 방안은 다단계 하도급을 구성하는 발주자-수급인-하수급인-노무자, 자재·장비업자 사이의 직접 지급 합의를 통한 대금지급시스템의 적용 수준에 머물러 있다. 이렇게 직접 지급 합의를 통한 대금지급시스템의 고도화는 신속한 공사대금 지급을 할 수 없을 뿐만 아니라 체불 및 하도급대금의 미지급 위반 등의 하도급법 위반 문제까지 해결하기 어려울 것으로 본다. 이에 대금지급시스템에 민간 건설 현장에 시범적으로 적용되고 있는 공사대금 채권신탁 방안을 보완 적용 함으로써 공사대금 채권 가압류 및 정산분쟁 등으로 인해 발생되는 다수의 대금 지급시스템의 문제점을 해결함으로써 건설 현장 관련 이해관계인 모두가 동반성장 상생 협력하는 공정한 문화를 정착해 나가야 한다.

PURPOSES : This study aims to evaluate the applicability of ground penetrating radar (GPR) for surveying utility pipes under sidewalks made of concrete brick and plate-stone block pavements. METHODS : GPR tests were conducted at two test sections to detect layer boundary and utility pipes under the pavements. The central frequency of the single-channel GPR was 800, 500, 250, and 100 MHz, and the central frequency of multi-channel (8) GPR was 450 MHz. GPR signals were analyzed in terms of 1-D (A-scan) and 2-D (B-scan) profiles. RESULTS: From the A-scan data analysis, the vertical resolution of the GPR ranged from 7.3 cm for 800 MHz to 133.1 cm for 100 MHz in the concrete brick block pavement and 13.9 cm for 800 MHz to 144.2 cm for 100 MHz in plate stone block pavement. From the B-scan data analysis, 250 MHz to 500 MHz GPR was sufficient to differentiate the layer boundary at a depth of 1.0~1.5 m to detect utility pipes at a depth of 0.5~2.0 m in both block pavements. In the plate-stone block pavement, GPR signal attenuation was greater because of the wire mesh in the concrete layer. Thus, the penetration depth was approximately 80% of the concrete brick-block pavement. CONCLUSIONS : The penetration depth and vertical resolution of GPR in the sidewalk paved with blocks were comparable to those of roadway pavement. Among the GPR evaluated, the 250 MHz GPR was the most desirable, and the 500 MHz GPR was affordable for the investigation of underground pipes situated up to 2.0~3.0 m under sidewalks.

다성분계 휘발성 유기화합물(VOCs; Volatile Organic Compounds)의 분리를 위하여 상전이법을 이용하여 방사 한 poly (ether imide) (PEI) 중공사 지지체에 poly (dimethylsiloxane) (PDMS)를 코팅하여 중공사 복합막을 제조하였다. VOCs 회수용 중공사막으로서 적합성을 알아보기 위해서 중공사막의 모폴로지, 질소 및 산소 기체 투과도를 측정하고, 벤젠, 톨루엔 그리고 자일렌에 대한 내구성을 조사하였다. 다성분계 휘발성 유기화합물의 효과적인 분리성능을 조사하기 위하여 Stage-cut과 feed 농도에 따른 다성분계 VOCs 투과 성능 변화를 관찰하였다. PEI 지지체 중공사막에 PDMS를 코팅시킴 에 따라 산소와 질소 투과도는 각각 45,000 GPU와 49,450 GPU에서 63 GPU와 30 GPU로 감소하는 것을 확인하였다. VOCs 투과농도는 Stage-cut이 감소함에 따라 증가하나, 회수율은 감소하였다. 반면에 공급농도 증가에 따라 투과농도는 비례적으로 증가하였지만, 농축비나 회수율은 큰 변화가 없었다.

도장공정에서 발생되는 휘발성 유기화합물의 회수를 위하여 중공사 분리막 모듈을 이용한 공정을 준비하여, 공급 압력과 시간변화에 따른 휘발성 유기화합물의 회수에 대한 특성평가를 실시하였다. 중공사 분리막 모듈을 도장공정에 직접 적용한 결과, 투과된 휘발성 유기화합물의 농도는 투과시간과 압력의 증가됨에 따라 증가되었으며, 단일공정보다 다단공정이 더 우수한 분리성능을 나타내는 것을 확인하였다.

정상 성인의 망막 신경섬유층을 측정하여 연령에 따른 망막 신경섬유층의 감소와 성별 망막 신경섬유층(Retina Nerve Fibre Layer) 의 차이를 비교 분석하기 위하여， 2004년 5월에서 10월까지 서울00 병원 외래 내원환자 중 136안을 대상으로 Optical Coherence Tomography(Stratus Model 3000, Carl Zeiss. Meditec inc. Dublin. CA U.S.A. Software Version 3.0) 와 Variable Cornea Compensation(Laser Diagnostic Technologies. inc, San Diego. CA. U.S,A. Software Verision 5.5.4)을 시 행하였다. ANOVA 분석을 통한 정상 성인의 연령에 따른 망막 신경섬유층의 변화는 VCC 측정 값에 서 TSNIT SD, Superior ratio, Superior씨asal ， Maximum modulation, Ellip modulation, Ellip SD 이 통계적으로 유의하였으며， Superior, Inferior average는 연령 증가에 따라 RNFL 의 값이 1-2μm 감소하는 경향을 보였으나 유의성이 없었다 OCT 측정 값은 Superior Maximum/Nasal A verage, Maximum!Minímum, Superior Maxímum에서 통계적으로 유의한 차이를 보였으며， Superior A verageQ} Inferior Average는 RNFL 의 값이 평균 3-4μm 감소하는 양상을 보였으나 유의성이 없었다. VCC와 OCT 측정값 모두 성별에 따른 RNFL의 차이는 없는 것으로 나타났다. 또 한 VCC 와 OCT 측 정 값에 서 Superior A verage, Inferior A verage 빛 Thickness Average는 낮은 상관성을 보였다. VCC와 OCT로 측정한 정상 성인의 연령증가에 따른 RNFL 변화도 및 두 기기의 상관성을 명확하게 입증하기 위해서는 후속 연구가 필요한 것으로 생각된다.

The spinel LiMn2O4 powders were synthesized at 480℃ for 12 h in air by a sol-gel method using manganese acetate and lithium hydroxide as starting material and the Fe3O4 powders were synthesized by the precipitation method using 0.2M-FeSO4·H2O and 0.5M-NaOH. The synthesized Fe3O4 powders were mixed at portion of 5, 10, 15 and 20 wt% about LiMn2O4 powders through ball-milling followed by drying at room temperature for 48 h in air. The mixed catalysts were reduced at 350℃ for 3 h by hydrogen and the decomposition rate of carbon dioxide was measured at 350℃ using the reduced catalysts. As the results of CO2 decomposition experiments, the decomposition rates of carbon dioxide were 85% in all catalysts but the initial decomposition rates of CO2 were slightly high in the case of the 5%-Fe3O4 added catalyst.

For decompose carbon dioxide, manganese oxide was synthesized with 0.25M-MnSO4·nH2O and 0.5M-NaOH by coprecipitation. We made magnetite deoxidized manganese oxide by hydrogen reduction for 1hour at 330℃. We investigated characteristics of catalyst, hydrogen reduction degree and decomposition rate of carbon dioxide. The structure of the hausmannite certified spinel type. The specific surface area of synthesized hausmannite and deoxidized hausmannite were 22.36m2/g, 33.56m2/g respectively. The decomposition rate of CO2 of deoxidized hausmannite was 57%.

On June 5, 2008, the “Act on Special Cases Concerning the Simplification of Authorization and Permission Procedures for Industrial Complexes” (Act No. 9106) was enacted. When it was implemented in August 2008, many industrial complex development projects were established, and the number of industrial complexes growth rates of 3 6% during 2003 2007 rose to around 15% in 2008. With the increase in industrial complexes, the environmental impacts of individual projects were examined, but comprehensive regional reviews of environmental impacts were not undertaken. In this study, we determined changes in air quality by applying the industrial complex development plan that completed the consultation at the end of 2010 to assess the comprehensive regional environmental impacts and presented the adequacy review plan for future industrial development plans based on the study’s results. When considering these industrial complex development plans, emissions in North Jeolla and South Chungcheong Provinces and Daegu City have increased significantly. Air quality analyses showed that the 24 h mean SO2 concentration in Daegu increased by more than 50% in summer compared to air quality concentrations in summer. The 24 h mean PM10 and NO2 concentrations increased by approximately 12 and 30%, respectively, in North Jeolla Province in summer. Areas exceeding the air quality standard for 1 h mean O3 concentration increased by more than 3,500 km2. Based on the above analysis, changes in air quality should be anticipated through a comprehensive evaluation of long-term development plans. Furthermore, control of air quality in accordance with the development of future industrial complexes is possible.

A comparison of ozone simulations in the seoul metropolitan region (SMR) using the community multiscale air quality (CMAQ) model with SAPRC99 and CB05 chemical mechanisms (i.e. EXP-SP99 and EXP-CB05) has been conducted during four seasons of 2012. The model results showed that the differences in average ozone concentrations between the EXP-SP99 and EXP-CB05 were found to be large in summer, but very small in the other seasons. This can be attributed that the SAPRC99 tends to produce more ozone than the CB05 in urban area like the SMR with low VOC/NOx ratio under high ozone conditions. Through quantitative comparison between two mechanisms for the summer, it was found that the average ozone concentrations from the EXP-SP99 were about 3 ppb higher than those from the EXP-CB05 and agreed well with the observations. Horizontal differences in ozone concentrations between SAPRC99 and CB05 showed that significant differences were found in southern part of the SMR and over the sea near the coast in summer.

The accuracy of ozone sensitivity coefficients estimated with HDDM (High-order Decoupled Direct Method) can vary depending on the NOx (Nitrogen Oxides) and VOC (Volatile Organic Compound) conditions. In order to evaluate the applicability of HDDM over the Seoul Metropolitan Area (SMA) during a high ozone episode in 2007 June, we compare BFM (Brute Force Method) and HDDM in terms of the 1st-order ozone sensitivity coefficient to explain ozone change in response to changes in NOx and VOC emissions, and the 2nd-order ozone sensitivity coefficient to represent nonlinear response of ozone to the emission changes. BFM and HDDM estimate comparable ozone sensitivity coefficients, exhibiting similar spatial and temporal variations over the SMAduring the episode. NME (Normalized Mean Error) between BFM and HDDM for the episode average 1st- and 2nd-order ozone sensitivity coefficients to NOx and VOC emissions are less than 3% and 9%, respectively. For the daily comparison, NME for the 1st- and 2nd-order ozone sensitivity coefficients are less than 4% (R2> 0.96) and 15% (R2> 0.90), respectively. Under the emission conditions used in this study, two methods show negative episode average 1st-order ozone sensitivity coefficient to NOx emissions over the core SMA. The 2nd-order ozone sensitivity coefficient to NOx emissions leads ozone to respond muchnonlinear to the reduction in NOx emissions over Seoul. Nonlinear ozone response to reduction in VOC emissions is mitigated due to the 2nd-order ozone sensitivity coefficientwhich is much smaller than the 1st-order ozone sensitivity coefficient to the emissions in the magnitude.