• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.334-338
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• 2011

일반적으로 유역에서 발생하는 토양손실은 붕괴사면과 표면침식, 토사류 붕괴에 의한 운반, 하상의 침식등 자연적인 요인과 도로건설, 산림의 벌채, 단지개발 등 인위적인 원인으로 발생할 수 있다. 토양손실의 발생은 농업생산성을 떨어뜨리고 목초지를 손상시키며, 물의 흐름을 방해하여 홍수위 상승, 저수지의 저수용량 감소, 고탁수 등 다양한 문제를 야기 시킨다. 이러한 문제를 해결하기 위해선 우선 토양손실 발생의 위험지역을 선정하고 그 지역을 집중적으로 관리하는 적절한 관리 대책의 마련이 필요하다. 이에 본 연구에서는 낙동강유역 전체를 대상유역으로 선정하고 토양손실 발생에 영향을 주는 여러 요소중 도시화나 농경지 확장 등 인간의 인위적인 개발로 인해 쉽게 변경될 수 있는 토지이용도를 이용하여 세부적으로 분석하였다. 토지이용도를 구성하고 있는 총 8가지의 토지이용항목 중 다른 항목들에 비해 분포면적이 매우 작은 녹지, 습지, 나지를 제외한 5가지의 항목(시가화, 논, 밭, 산림, 수역)의 분포면적을 통해 토지 이용특성에 따른 유사발생의 연관성을 파악하였으며 유역별 유사발생 위험순위를 평가하였다. 유사발생 위험순위 평가결과, 전체 낙동강유역내 유사발생 위험성이 높은 표준유역들로 구성되어있는 중권역은 내성천, 위천합류점, 합천댐유역, 안동댐유역으로 모두 높은 순위를 차지했다. 내성천유역, 위천합류점 유역, 합천댐유역은 구성하고 있는 표준유역의 절반 이상이 높은 순위들로 구성되어 있으며 안동댐유역은 구성하고 있는 소수의 표준유역이 유역내 최상위 순위를 차지하였다.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2011.11a
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• pp.50-50
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• 2011

국내 섬유산업은 해외로부터의 저가 섬유제품이 대량으로 유입되는 속에서도 수출의 상당한 부분을 차지하며, 꾸준히 양에서 질로의 전환을 도모해 왔으며, 특히 최근에는 섬유 전반에 걸쳐 고부가 가치화를 지향하고 있다. 이러한 소비자의 요구에 부응하여 섬유소재에도 다양한 신개념과 이를 충족시킬 수 있는 기술이 요구되고 있으며, 그 가운데 하나의 영역을 구축해 나가고 있는 분야가 면 리플가공과 같은 표면 형태 가공이며, 최근 들어 폴리에스테르 입체(3D)가공제의 개발 및 가공 방법도 이런 흐름에 부응하여 업계에서 절실한 개발을 요구하고 있는 분야이다. 기존의 폴리에스테르 및 합성섬유의 입체 가공에 적용된 화학제품보다 성능은 우수하면서, 가공 공정이나 완성된 섬유제품에 전혀 잔존하지 않아 인체친화적(기존의 제품들은 인체에 유해한 재료이면서 가공 후 잔존함)이며, 환경적인 측면에서도 친환경을 유지하면서 새로운 폴리에스테르섬유, 좀 더 폭넓게는 열가소성인 모든 합성섬유의 입체가공이 가능한 약품의 개발 및 이를 이용한 가공방법의 개발은 매우 중요한 의의를 가지게 된다. 본 연구에서는 폴리에스테르의 3D입체 디보싱을 부여하는 합성바인더가 물에 의한 용해도를 확인하기 위하여 용액의 PH에 따른 용해성 시험을 진행하였으며, 합성한 발포제의 양에 따른 3D입체형성 정도를 이미지로 형상화 하였다.

• The Journal of Engineering Geology
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• v.32 no.2
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• pp.271-280
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• 2022

Landfast sea ice forms near coastlines in polar regions. Continuous monitoring of this sea ice is important, as it plays a key role in the marine ecosystem and affects the operation of nearby research stations. This study detected landfast sea ice around Jang Bogo research station in East Antarctica by stacking interferometric coherence images of Sentinel-1 synthetic aperture radar (SAR) data with 6-, 12- and 18-day temporal baselines. A total of 50 landfast sea ice maps were generated covering July 2017 to June 2018. The time series revealed regional differences in the timing of the maximum extent as well as growth rate of landfast sea ice. Overall, detecting landfast sea ice using interferometric SAR coherence seems promisingly feasible; however, limitations remain owing to low backscattering coefficients from new and smooth sea ice surfaces and subtle movements of sea ice in contact with the Campbell Glacier Tongue.

• Journal of the Korean Institute of Landscape Architecture
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• v.43 no.3
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• pp.101-113
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• 2015

The purpose of this study is increasing ventilation network usability for urban green space planning by enhancing its practicality and detail. A ventilation network feature extraction technique using roughness length($z_0$) was proposed. Continuously surfaced DZoMs generated from $z_0$(cadastral unit) using three interpolations(IDW, Spline, and Kriging) were compared to choose the most suitable interpolation method. Ventilation network features were extracted using the most suitable interpolation technique and studied with land cover and land surface temperature by spatial overlay comparison. Results show Kriging is most suitable for DZoM and feature extraction in comparison with IDW and Spline. Kriging based features are well fit to the land surface temperature(Landsat-7 ETM+) on summer and winter nights. Noteworthy is that the produced ventilation network appears to mitigate urban heat loads at night. The practical use of proposed ventilation network features are highly expected for urban green space planning, though strict validation and enhancement should follow. (1) $z_0$ enhancement, (2) additional ventilation network interpretation and editing, (3) linking disconnected ventilation network features, and (4) associated dataset enhancement with data integrity should technically preceded to enhance the applicability of a ventilation network for green space planning. The study domain will be expanded to the Seoul metropolitan area to apply the proposed ventilation network to green space planning practice.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.2D
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• pp.245-253
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• 2009

Road facility is the most fundamental infrastructure for traffic and various information for smooth traffic is included in road surfaces. Various information included in road surfaces should be often removed and reinstalled by partial damage and aging. In addition, the existing road surface information should be removed in order to mark new information as traffic information changes. The existing road surface removal method suing grinders and torches had problems such as dangerous working equipment and workers' direct exposure to cars. In addition, although water-jet system using super high-pressure water was used to remove road surface in order of improvement of traditional method, there are another problems such as limitations according to water-tanks and water frost on the road surfaces after work. Therefore, this study analyzes and suggests systems to develop prototype after analyzing dry ice blaster in order to improve the current road surface removal methods. In addition, the study analyzes the possibility of introduction of dry ice blaster through a test for proposing an automatized equipment for new road surface mark removal considering environment and work efficiency, and compare traditional method with introduced dry ice blaster for operating cost.

• Journal of the Korean Applied Science and Technology
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• v.34 no.2
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• pp.349-356
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• 2017

OH radical generation is one of the common method to evaluate photocatalytic activity. In many of previous studies, only the UV(Ultraviolet) light was applied to test photocatalytic ability of $TiO_2$ nanotubes by studying probe compound(4-Chlorobenzoic acid) concentration change in solution. Also, $TiO_2$ nanotubes were found to show some electrochemical characteristics when the flow of electric current was applied. In this study, the flow of electric current and UV light were applied at the same time to determine whether electrochemical characteristics of $TiO_2$ nanotube plate can give synergetic effect on the photocatalytic activity. $TiO_2$ nanotube was grown on Ti by anodic oxidation to create $TiO_2$ nanotube plate which can be used as a photocatalyst and a electrode that can undergo AOP(Advanced Oxidation Process) for water treatment. Probe compound solution was prepared using 4-chlorobenzoic acid and $H_2O$ as a solvent. NaCl was added to give conductivity to work as electrolyte. As a result, enough level of electric current flow was found to give synergetic photocatalytic effect which can be used for efficient AOP water treatment method.

• Journal of Korea Water Resources Association
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• v.52 no.4
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• pp.301-312
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• 2019

The importance of the dual drainage system model has increased as the urban flood damage has increased due to the increase of local storm due to climate change. The dual drainage model is a model for more accurately expressing the phenomena of surface flow and conduit flow. Surface runoff and pipe runoff are analyzed through the respective equations and parameters. And the results are expressed visually in various ways. Therefore, inundation analysis results of dual drainage model are used as important data for urban flood prevention plan. In this study, the applicability of the COBRA model, which can be interpreted by combining the dual drainage system with the natural watershed and the urban watershed, was investigated. And the results were compared with other dual drainage models (XP-SWMM, UFAM) to determine suitability of the results. For the same watershed, the XP-SWMM simulates the flooding characteristics of 3 types of dual drainage system model and the internal flooding characteristics due to the lack of capacity of the conduit. UFAM showed the lowest inundation analysis results compared with the other models according to characteristics of consideration of street inlet. COBRA showed the general result that the flooded area and the maximum flooding depth are proportional to the increase in rainfall. It is considered that the COBRA model is good in terms of the stability of the model considering the characteristics of the model to simulate the effective rainfall according to the soil conditions and the realistic appearance of the flooding due to the surface reservoir.

• Journal of Dental Rehabilitation and Applied Science
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• v.25 no.4
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• pp.361-374
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• 2009

For successful osteogenesis around the implants, interaction between implant surface and surrounding tissue is important. Biomechanical bonding and biochemical bonding are considered to influence the response of adherent cells. But the focus has shifted surface chemistry. The purpose of this study is to evaluate the MC3T3-E1 osteoblast like cell responses of magnesium (Mg) ion implanted titanium surface produced using a plasma source ion implantation method. Commercially pure titanium disc was used as substrates. The discs were prepared to produce four different surface, A: Machine turned surface, B: Mg implanted surface, C: sandblasted surface, D: sandblasted and Mg implanted surface. MC3T3 El osteoblastic like cells were cultured on the disc specimens. Cell adhesion, proliferation, differentiation, and synthesis of extracellular matrix were evaluated. The cell adhesion morphology was evaluated by SEM. RT PCR assay was used for assessment of cell adhesion, proliferation and differentiation. ALP activity was measured for cell differentiation. The results of this study were as follows: 1. SEM showed that cell on Mg ion groups was more proliferative than that of non Mg ion groups. On the machine turned surface, cell showed some degree of contact guidance in aligning with the machining grooves. 2. In RT PCR analysis, osteonectin and c-fos mRNA were more expressed on sandblasted and Mg ion implanted group. 3. ALP activity was not significantly different among all groups. Within the limitations of this study, the following conclusions were drawn: It might indicate Mg ion implanted titanium surface induce better bone response than non Mg ion groups.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.9
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• pp.1-11
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• 2016

The effect of the migration of nanoparticles near the wall of a channel on the convective heat transfer in a laminar flow of $SiO_2$ nanoparticle suspensions (nanofluids) under constant wall heat flux boundary conditions was numerically and experimentally investigated in this study. The dynamic thermal conductivity of the aqueous $SiO_2$ nanofluids was measured using T-type thermocouples attached to the outer surface of a stainless steel circular tube (with a length of 1 m and diameter of 1.75 mm). The nanofluids used in this study were synthesized by dispersing $SiO_2$ spherical nanoparticles with a diameter of 24 nm in de-ionized water (DIW). The enhancement of the thermal conductivity of the nanofluids (e.g., an increase of up to 7.9 %) was demonstrated by comparing the temperature profiles in the flow of the nanofluids with that in the flow of the basefluids (i.e., DIW). However, this trend was not demonstrated in the computational analysis, because the numerical models were based on continuum assumptions and flow features involving nanoparticles in a stable colloidal solution. Thus, to explore the non-continuum effects, such as the modification of the morphology caused by nanoparticle-wall interactions on the heat exchanging surfaces (e.g., the isolated and dispersed precipitation of the nanoparticles), additional experiments were performed using DIW right after the measurements using the nanofluids.

• Applied Chemistry for Engineering
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• v.21 no.6
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• pp.648-652
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• 2010

Catalytic activities of the partial oxidation of methane (POM) to hydrogen were investigated over Pd(5)/Ti-SPK and Pd(5)/Zr-SPK in a fixed bed flow reactor (FBFR) under atmosphere, and the catalysts were characterized by BET, XPS, XRD. The BET surface areas, pore volume and pore width of Horvath-Kawaze, micro pore area and volume of t-plot of Pd(5)/Ti-SPK and Pd(5)/Zr-SPK were $284m^2/g$, $0.233cm^3/g$, 3.9 nm, $30m^2/g$, $0.015cm^3/g$ and $396m^2/g$, $0.324cm^3/g$, 3.7nm, $119m^2/g$, $0.055cm^3/g$, repectively. The nitrogen adsorption isotherms were type IV with hysteresis. XPS showed that Si 2p and O 1s core electronlevels of Ti-SPK and Zr-SPK substituted Ti and Zr shifted to slightly lower binding energies than SPK. The oxidation states of Pd on the surface of catalysts were $Pd^0$ and $Pd^{+2}$. XRD patterns showed that crystal structures of fresh catalyst changed amorphous into crystal phase after reaction. The conversion and selectivity of POM to hydrogen over Pd(5)/Ti-SPK and Pd(5)/Zr-SPK were 77, 84% and 78, 72%, respectively, at 973 K, $CH_4/O_2$ = 2, GHSV = $8.4{\times}10^4mL/g_{cat}{\cdot}h$ and were kept constant even after 3 days in stream. These results confirm superior activity, thermal stability, and physicochemical properties of catalyst in POM to hydrogen.