본 논문은 Ni - Al2O3로 구성된 금속-세라믹 이종 입자복합재의 2차원 미세구조(microstructure) 생성과 미세구조 스케일 (scale)에 따라 정의되는 계층적 모델들의 역학적 특성 분석에 관한 내용이다. 이종 입자복합재의 미세구조는 수학적인 RMDF(random morphology description functions) 모델링기법을 복합재의 2차원 RVE(representative volume element) 영 역에 적용하여 생성하였다. 그리고 미세구조 생성에 필요한 가우스 함수들의 개수에 따라 미세구조의 계층적 모델을 정의하였다. 한편 임의 미세구조 내 금속과 세라믹 입자가 차지하는 체적분율(volume fraction)은 RMDF 함수의 레벨을 조정함으로서 설정하였다. RMDF기법에 의한 미세구조들은 가우스 함수들의 개수가 일정할지라도 랜덤하게 생성된다. 이렇게 랜덤 하게 생성되는 미세구조들을 2차원 보(beam) 모델에 적용하여 미세구조의 스케일에 따른 수직응력과 전단응력의 계층적 변 동을 수치 해석적으로 고찰하였다. 또한, 균열해석을 통해 RMDF의 랜덤성과 가우스 함수들의 개수가 균열선단에서의 응력 값에 미치는 영향을 고찰하였다.

FRP is a new material that has light, high strength and high durability characteristics and is emerging as a third construction material in and out of countries. However, very few studies have been done on curved FRP construction materials that can be used for tunnels or arched bridges. In particular, many joints are required for the application of curved panels to the open cut tunnel. Experimental data on the performance of the joint is required due to insufficient design criteria. The purpose of this study is to analyze the structural performance of real size, composite materials curved panels. To achieve this goal, curved panels were constructed and bending performance was tested. A numerical analysis was also performed and compared with the results of the test. The results of the test showed that the average load was 757.6 kN and the average displacement of bottom was measured at 53.12 mm. Compression stress on the upper flange and tensile stress on the lower flange were within acceptable limits of 50% of the allowable stress.

In the 1930s, The Architectural Association of Joseon run the ‘Architectural Material Display’ on the 2nd floor of the Japan Life Insurance Building in Hwanggumjeong(currently Euljiro street). The purpose of this place was to introduce new architectural materials to builders. And they issued a 『建築資料型錄(Architectural Material Catalog)』and distributed it free of charge so that people in districts at long distances can make use of it. This catalog contains descriptions, photographs and drawings of various architectural materials that were common at the time, and the overseas branch address of the store is stated. The purpose of this research is to investigate the type and characteristics of architectural materials distributed in Northeast Asia around the 1930s, the region of sale, affiliated companies by closely analyzing the 『建築資料型錄』.

Lithium-ion batteries have been considered the most important devices to power mobile or small-sized devices due to their high energy density. LixCoO2 has been studied as a cathode material for the Li-ion battery. However, the limitation of its capacity impedes the development of high capacity cathode materials with Ni, Mn, etc. in them. The substitution of Mn and Ni for Co leads to the formation of solid solution phase LiNixMnyCo1-x-yO2 (NMC, both x and y < 1), which shows better battery performance than unsubstituted LiCoO2. However, despite a high discharge capacity in the Ni-rich compound (Ni > 0.8 in the metal site), poor cycle retention capability still remains to be overcome. In this study, aiming to improve the stability of the physical and chemical bonding, we investigate the stabilization effect of Ca in the Ni-rich layered compound Li(Ni0.83Co0.12Mn0.05)O2, and then Ca is added to the modified secondary particles to lower the degree of cationic mixing of the final particles. For the optimization of the final grains added with Ca, the Ca content (x = 0, 2.5, 5.0, 10.0 at.%) versus Li is analyzed.

The objective of this study was to estimate physical properties and fishing performances of net twine with improved PBS copolymer resin (Bio-new), the existing PBS/PBAT blending resin (Bio-old) and commercial Nylon (Nylon). The tensile strength of Bio-new monofilament was equal to Bio-old and the elongation of Bio-new was about 6 % higher than that of Bio-old in wet condition. The physical properties tests were carried out to estimate breaking load and stiffness in dry and wet conditions, respectively. In the results, the breaking load of Nylon netting was the highest whereas the elongation of Bio-new was 1.4 times higher than that of Nylon netting in wet condition. The breaking load of Bio-old netting was about 9.2 % higher than that of Bio-new netting. However, the elongation of the Bio-new netting was about 3% higher than that of Bio-old. The stiffness of the Bio-new compared to Bio-old was improved about 34 % in dry condition and about 32 % in wet condition. The filed experiments of the fishing performance were conducted with three kinds of drift nets with different netting materials in the coastal sea of Jeju. The each experimental drift net made of different materials showed the similar fishing performance. Bio-old drift net yielded less catches of small sized yellow croaker than other drift nets. The netting materials affected the fishing performance and length distribution of catches in the drift nets.

This study was conducted to develop a heat interception permeability aggregate pavement material that resists increase of air temperature and has permeability by decreasing pavement temperature of city in summer. For this study, a heat interception polymer binder mixed with heat interception material and polyurethane binder. And the study made heat interception permeability aggregate pavement material by mixing heat interception polymer binder. Using the materials, the study conducted flexural strength test and temperature reduction effect experiment. As the result, flexural strength was 5.43MPa average and the temperature reduction effect was effective up to maximum 16 degrees Celsius compared to current asphalt concrete.

The bond property is mightily important in asphalt construction site as overlay, post-cutting overlay and new establishment of asphalt pavement. If the bonding between the lower and upper pavements isn't approriately applied, the slipping phenomenon can happen due to the tensile stress and shear stress. It can resultantly take the forms of the rutting, failure and other damages. Moreover, the greater damage phenomenon from the intense reflection cracking can be generated when the appropriate methods regarding the cracks or failures on the lower pavement aren't conducted and the bonding with its pavements isn't properly applied. In this regard, the researched content on the existing research is shown below. The types of asphalt emulsion applied to the pavement construction site are classified as Tack-Coat and Prime-Coat in South Korea. The application purpose of Tack-Coat is to bond the pavements comprised of the rigid material. And the application objective of Prime-Coat is to attach the layers consisting the disturbed materials. The best performance related to the optimum application rates depends on the type or property of the emulsified asphalt materials. To solve these phenomenons, the various researches have been globally done. The test methods to obtain the optimum application rates of the asphalt emulsion vary in different organizations or countries. The objective of this research is to develop the tester for Tack-Coat bonding property in accordance with the standards and circumstances of the pavement construction in South Korea. In the nation, the application rate of Tack-Coat is presented as 0.3 l/m2 ~ 0.6 l/m2 in the construction specification and pavement design guideline published in the Ministry of Land, Infrastructure and Transport (MOLIT), but there aren't the specific suggestions. And, it depends on the superintendents or the ordering bodies in the construction sites. In that regard, the objectives of this paper are listed below. First, Suggestion of the test methods regarding the Interlayer Shear Strength in accordance with the domestic construction conditions and standards. Second, Development of the tester for conducting various tests using a tester. Last, Development of the predictive model for the optimum application rates of the emulsified asphalt.

It has been recognized that the performance of pavements is closely related to the properties of the underlying unbound layers and subgrade. It has also been recognized that unbound pavement materials possess a complex nature and often exhibit nonlinear behaviors [1, 2]. The Mechanistic-Empirical Pavement Design Guide (MEPDG) is founded on the use of resilient modulus as the primary input parameter when characterizing unbound pavement materials [3, 4]. The resilient moduli of unbound materials are typically determined by performing repeated load triaxial (RLT) tests in the laboratory. Due to that laboratory resilient modulus tests require sophisticated equipment and trained operators following complicated test procedures, many transportation agencies may not have access to the laboratory facility and opt to correlate resilient modulus with field tests [5]. The long-term pavement performance (LTPP) program offers a large and diverse database that includes a range of laboratory-derived and field-derived properties for unbound materials of many in-service pavement sections. This study is aimed to utilize LTPP data to develop a correlation between the laboratory-derived resilient modulus and a field-derived parameter, dynamic cone penetration index (DCPI) for unbound aggregate materials. Data extracted from the LTPP database were subjected to a thorough quality check to ensure that the data are of good quality and without errors. One-on-one univariate regression was first performed to examine the significance of different variables, including DCPI and some physical properties such as dry unit weight, water content, plasticity index, percent passing No.200 sieve. The physical properties that show strong correlation were selected to be combined with field test parameter (DCPI) to conduct a multivariate regression analysis. A statistical model was developed for the prediction of resilient modulus of unbound aggregates from the DCP test parameters and physical properties. The model predicted a separate data set that did not participate in the correlation analysis, suggesting the success of applying the DCP test in evaluating the resilient modulus of pavement unbound aggregate materials.

Recently in Construction field, It has been the big issues to produce an Eco-friendly Construction material and to solve problems about the First grade–Aggregates’ supply&demand. While the Eco-friendly Construction materials which are refurbished and reproduced from construction wastes and industrial by-products have a great deal of effectiveness such as cost or CO2 emission reduction, there is an additional logistical cost due to go through with some processes for recycle such as Intermediary treatments or management and collection of materials. Furthermore, Demand of the First grade-Aggregates is rising and spreading all over the nation for the improvement of Road driving performance, But there is also an additional logistical cost for supply&demand due to the cost of transport growth by sites of construction. In this study, the process and methodology of the new material supply and demand route routings using the Arc Gis Program and the calculation of the available distance through economic analysis are presented. After examining the cost status of construction materials and logistics costs by examining the literature review and related industry, economic feasibility was obtained by comparing the price of general construction materials with the total cost of comparable materials and logistics costs. After an economic analysis, ArcGis3.0 was used to visualize the materials’ supply&demand route and As a result, We can observe the economically secured route from the construction materials’ production plant to where the domestic transportable route and nodes mapped. Throughout the study, the pre-groundwork for an efficient use of the construction materials is able to be prepared and It will be helpful to invigorate supply&demand. In addition to the economic analysis in the future, If the real-time traffic information (traffic volume, speed, environment, etc.) and the performance (structure, functionality, etc.) of each construction materials are reflected, It will be possible to build a decision system for selecting construction materials which meet consumers’ various needs.

Road network in the Mekong Delta is mostly coastal and river routes, then they are often flooded when the floods come in. As a result, the foundation and pavement are destroyed, reduced life expectancy, resulting in unsafety in traffic, cost of maintenance and repairs…. This paper establishes the technical conditions for the calculation on the flexible pavement working in the wet conditions (so flooded) based on the maximum usage of available materials in the provinces in the Mekong Delta. Simultaneously, we propose the flooded flexible pavement under the current climate change conditions.

New three emitting compounds, AK-1, AK-2 and AK-3 including diazocine moiety were synthesized through Suzuki-coupling reaction. Physical properties such as optical, electroluminescent properties were investigated. UV-visible spectrum of AK-1, AK-2 and AK-3 in film state showed maximum 392, 393 and 401 nm. PL spectrum of AK-1, AK-2 and AK-3 showed maximum emission wavelength of 472, 473 and 435 nm. Three compounds were used as EML in OLED device: ITO/2-TNATA (60 nm)/NPB (15 nm)/EML (35 nm)/Alq3 (20 nm)/LiF (1 nm)/Al (200 nm). AK-3 OLED device showed C.I.E value of (0.18, 0.26) and luminance efficiency of 0.51 cd/A at 10 mA/cm2. New derivatives including diazocine moiety were introduced as OLED emitting material and the EL efficiency was increased by the proper combination of core and side group.

A new green light emitting compound based on tris (N-methylindolo) benzene (NMTI), anthracene and pyrene was synthesized. NMTI-An and NMTI-Py were used as the light emitting layer of the OLED element to investigate the luminescence characteristics. The OLED device containing NMTI - NPB luminescent layer and hole transport layer (HTL) showed superior characteristics compared to NMTI-Py. The device exhibited maximum EL emission at 502 nm and 550 nm, CIE coordinates (0.38, 0.48) and a luminance efficiency of 2.06 cd/A. Also, when NMTI and NMTI-An were used as HTL instead of NPB, the device containing NMTI-An emitter showed 2.67 cd/A and 2.29 cd/A in luminescence efficiency.

Two emitting compounds, 9,10-bis-[1,1;3,1]terphenyl-5-yl-1,5-di-o-tolyl- anthracene [TP-DTA-TP] and 9,10-bis-phenyl[1,1;3,1]triphenyl-5-yl-1,5-di-o- tolylanthracene[ TPB-DTA-TPB] based on newtwisted core moiety were synthesized through boration, Suzuki reaction, and Sandmeyer reactions. EL performance was improved by varying the chemical structure of the side group. Physical properties such as optical, electrochemical, and electroluminescent properties were investigated. Synthesized compounds were used as an EML in OLED device: ITO/2-TNATA (60 nm)/NPB (15 nm)/TP-DTA-TP or TPB-DTA-TPB (35 nm)/Alq3 (20 nm)/LiF (1 nm)/Al (200 nm). It was found that TPB-DTA-TPB showed higher luminance efficiency and better C.I.E. value than TP-DTA-TP device.

Membranes techniques used to convert chemical energy into electrical energy from energy sources such as hydrogen, salt water, and water. Membrane materials have transport property of desire molecular and barrier property for satisfy to requirement of cell performance. Typically, PFSA polymer is used to fabricate membrane. Each material has different characteristics depending on the membrane formation conditions. Macroscopic characteristics are difficult to correlation with molecular motion, mobility, and transport within membrane matrices. NMR spectroscopy can analysis about these characteristics by observing the molecule level. In this study, NMR spectroscopy can provide fundamental information of PFSA ionomers and correlation with macroscopic characteristics.

이온전도성 분리막을 이용한 산소 제조 기술은 효율적으로 산소를 제조할 수 있으며, 산소부화 연소기술, 순산소 연소기술 등에 적용 범위가 넓다. 고온에서 운전하는 특성상 열적, 화학적으로 안정적이어야 하며, 특히 이산화탄소 재순환기술을 적용하기 위해서는 이산화탄소 내성이 필수적이다. 본 연구에서는 높은 투과성능을 가지는 Ba0.5Sr0.5Co0.8Fe0.2O3-δ를 상전이 및 소결법으로 중공사막을 제조하였으며 표면을 페롭스카이트-플로라이트 이중상 물질로 개질하여 이산화탄소 내성을 갖도록 하였다. 제조한 분리막을 산소 분리 모듈에 적용하여 부피당 면적에 따른 투과도 및 산소 유량 변화를 관찰하였다.

해양경찰은 바다라는 극한 환경에서 임무수행 중 빈번히 사망·실종의 위험에 맞닥뜨린다. 사고 발생 시 신속한 신원확인을 위해 해양경찰연구센터는 해양경찰을 대상으로 DNA를 이용한 신원확인 시스템을 구축하였으며 사체가 발견되지 않을 경우를 대비해 국립 묘지 안장이 가능한 장치 또한 마련하였다. 순직· 실종 등 대비 신원확인용 인체유래물 보관사업 운영규칙에 따라 인체유래물의 관리, 보 관, 폐기, 품질검사가 진행되며 이는 관리위원회의 감시하에 행해진다. 한반도 해역에서는 매년 700여건의 해양 변사자가 발생하는데 사체가 늦게 발견되어 부패가 심하거나, 일부분만 발견되어 지문 또는 치아로 개인 식별이 불가능할 경우 해양 변사자의 신원확인을 위한 방법이 필요하다. 해양경찰연구센터가 운영중인 ‘인체유래물 보관사업’을 해양·수산 종사자, 관련 연구자, 해양 레저인에게까지 확대 실행 한다면 해양 변사자 신원확인에 큰 도움이 될 것이다.