In this study, a cobalt sulfate ceramic coating was sintered on various clays at 1250˚C. The specimen characteristics were investigated by X-ray diffraction(XRD), scanning electron microscopy(SEM), TG-DTA, UV-vis spectrophotometer, and HRDPM. The ceramic coating had a constant thickness of thousands μm, and the surface was confirmed to be densely fused. Other new compounds were produced by the cobalt sulfate sintering process and reactions. These compounds were a CoAl2O4 phase, Co2SiO4 phase, anorthite(CaAl2Si2O8) phase, and FeAl2O4 phase, respectively. UV properties of the coated specimen were investigated, celadon clay specimen in 530-550 nm band is showing a dark gray color. The white clay and white mix clay specimen in 460-500 nm band is showing a blue color. The cobalt-aluminate(CoAl2O4) spinel and the cobalt-silicate olivine(Co2SiO4) were the strongest of the ceramic pigments, producing a very pure, navy blue color.

As a part of the electromagnetic spectrum, microwaves heat materials fast and efficiently via direct energy transfer, while conventional heating methods rely on conduction and convection. To date, the use of microwave heating in the research of carbon-based materials has been mainly limited to liquid solutions. However, more rapid and efficient heating is possible in electron-rich solid materials, because the target materials absorb the energy of microwaves effectively and exclusively. Carbon-based solid materials are suitable for microwave-heating due to the delocalized pi electrons from sp2-hybridized carbon networks. In this perspective review, research on the microwave heating of carbon-based solid materials is extensively investigated. This review includes basic theories of microwave heating, and applications in carbon nanotubes, graphite and other carbon-based materials. Finally, priority issues are discussed for the advanced use of microwave heating, which have been poorly understood so far: heating mechanism, temperature control, and penetration depth.

목적: 본 연구는 콘택트렌즈 재료로 널리 사용되는 2-hydroxyethyl methacrylate, N-vinyl-2-pyrrolidone, methyl methacrylate, ethylene glycol dimethacrylate에 titanium isopropoxide와 tungsten(VI) oxide 나노입자를 첨가하여 안의료용 렌즈 재료를 중합하였다. 방법: 안의료용 콘택트렌즈의 첨가제로 Tungsten (VI) oxide 나노입자 사용의 활용도를 조사하기 위해 tungsten(VI) oxide 나노입자를 포함한 하이드로젤 콘택트렌즈 재료의 광학적, 물리적 특성 변화를 측정하였다. 결과: 생성된 고분자에 대한 자외선 영역의 투과율은 매우 낮게 측정되어 자외선 차단 능력이 있는 것으로 나타났다. 또한 tungsten(VI) oxide 나노입자의 첨가는 함수율의 큰 변화를 나타내지 않았으나 일정비율을 첨가한 조합에서는 소량의 함수율 변화가 나타났다. 함수율의 큰 변화가 없음에도 불구하고 산소침투율의 측정 값은 tungsten(VI) oxide 나노입자의 첨가 비율이 증가할수록 계속적으로 감소하는 경향이 나타 났다. 결론: 이상의 결과를 통해 titanium isopropoxide 및 tungsten(VI) oxide 나노입자는 하이드로젤 콘택트렌즈의 기본적인 물성을 만족시키면서 기능성 콘택트렌즈 재료로 유용하게 활용될 수 있을 것으로 판단된다.

Recent rapid development of the Chinese economy based on science and technology is challenging Korean industries and economy. Since the driving force for this rapid development of China is known to be scientific technologies, the purpose of this research is to confirm the current status of Chinese scientific research in the field of "Materials Science and Engineering" and propose a strategy for competition with China. Even though there are numerous journals of "Materials Science and Engineering", the 10 most popular journals with high impact factors were selected to cover general materials, nano materials, bio materials, and electronic materials. It was found that the number of scientific papers written by Chinese scientists for the materials field in the 10 journals was slowly increasing from the year 2000 until 2005, but has been rapidly increasing since 2005. This research found that Chinese research activities in the traditional metallic materials and nano materials have tremendously increased to occupy around 30 % or more papers published in several major journals related with materials science and engineering. On the other hand, bio materials and electronic materials research has not been pursued so actively; however, very recently the number of publications in these fields is also beginning to increase. To compete with this tremendously growing Chinese scientific development, Korea should have a policy of "selection and concentration" in materials-related fields, including basic science in nano, bio, and electronic materials.

퍼플루오르옥탄설포네이트를 LC/MS/MS를 이용하여 분석한 결과 분석 대상물질의 고유한 스팩트럼을 얻어 정량 하여 머므름 시간은 4.33분이었으며 상관계수(R2)은 0.9998 로 양호한 직선상의 그래프를 얻을 수 있었다. 퍼플루오르옥탄설포네이트에 대한 분석법의 회수율은 99.84%로 전반적으로 좋은 회수율을 보였으며 또한 이 연구에 적용되기에 충분한 정밀도와 정확도를 가지고 있음을 확인할 수 있었다. 퍼플루오르옥탄설포네이트 정량한계 및 검출한계 는 0.03, 0.009 ug/L이었다. 따라서 식품 용기포장재에서의 분석에 적용이 가능하였다.

The research is a correlational study to look for causes and factors relating to the design of written documents (professional reading materials) and identify those relationships that are useful for communication designers. The research specifically targeted the relationships between perception and reader’s past experiences and appearance of the written documents. A preliminary survey, such as interviews, discussions, questionnaires and brainstorming sessions are conducted to establish the observable attributes related to perception which are reader’s interests, importance of information and written documents complexity. Finally, the research used Structural Equation Model (SEM) to identify significant differences and analyze strong and weak correlations between these attributes. In general, the results of the study shows that the attribute appearances of a written documents with excellent visualizations for information display shows a strong correlation with interests while the attributes importance is weakly correlated with the complexity of the documents.

This study explores a group of 26 Korean EFL secondary teachers' experience with process drama during an intensive teacher training program conducted in the spring of 2013. The drama session consisted of five two-hour classes which introduced the main features of process drama by implementing it with the participants. Questionnaires, trainees' reflections, trainee's adaptation materials and researcher's teaching log were used to find out how the teachers perceived process drama and in what ways they wanted to adapt it in their teaching context. The result of the study shows that all of the teachers want to use process drama techniques in their classroom since it offers meaningful context as well as engaging atmosphere for the students to communicate spontaneously. The combination of tableau and thought-tracking is regarded as the most useful technique to adapt their classroom materials because it would provide opportunities not only to practice productive skills but also to develop creativity. More teacher training program and teaching materials about process drama were suggested to be developed for the convenient use of teachers.

Friction welding in dissimilar materials is widely applied in various engineering fields such as automobiles, rolling stocks, machine tools. Since interface edges of Friction-welded materials have stress singularity by differences of mechanical properties and temperature changes, it is necessary to assess stress singularity with the variation of flash shape and length. In this paper, the influences which the flashes created by friction welding concern to the stress singularity at interface edges are investigated. Through stress analysis by the BEM and static experiments, the influences were studied quantitatively, the stress singularity greatly depends on the shape of the flash and its size.

Recently, applied areas of nonferrous materials have been expanded in terms of efficiency of materials used and cost reduction. And, in accordance with compactness and accuracy of parts, the need of joining of dissimilar materials is raised. Accordingly, this study aimed at finding out the optimal welding current value(6.3～6.5kA) considering tensile strength, fracture test and welding residue after joining with various welding conditions by means of copper pipe(Φ7.0 × t0.5) and aluminium pipe(Φ7.0 × t0.7) using an eutectic diffusion bonding machine.

이 연구에서는 참깨 과립종자의 저장 시 활력손실 정도를 파악하여 적정한 저장 방법을 규명하기 위하여 저장고의 온도 를 4, 15, 25oC로 하고 상대습도를 40, 60, 80%로 달리하여 1개월 간격으로 4개월간 저장기간별로 종자의 수분함량 및 활력유지 정도를 비교하였다. 1. 무처리 종자의 수분함량이 가장 높게 나타났으며 점토 단 독처리이거나 점토성분이 함유된 과립에서는 수분함량이 많았 고, 활석처리에서는 종자수분함량이 가장 낮게 나타났다. 2. 상대습도가 80%일 때는 4oC에서 15oC와 25oC일 때보다 종자수분함량이 높게 나타났다. 3개월째는 종자수분함량이 가 장 높았으며 이때 발아율은 가장 낮았다. 3. 종자활력검사결과를 종합해보면 점토+질석의 조합으로 과 립화할 경우 15oC이하이면서 상대습도 80%이하로 저장할 경 우 50%이상의 활력을 3개월 이상 유지할 수 있었다. 그러나 25oC로 저장할 경우 2개월까지만 가능하였다. 점토 +피트모 스 +활석의 조합으로 과립화할 경우 15oC이하이면서 상대습 도 80%이하의 조건에서 2개월까지 50% 이상의 활력유지가 가능하였지만, 25oC이하와 상대습도 80%이하의 조건에서는 1 개월까지만 저장 가능하였다. 활석 단독으로 과립화할 경우 25oC이하 및 상대습도 80%이하의 조건에서 1개월까지만 저장 가능하였다. 따라서 점토+질석의 조합으로 과립화하였을 때 종 자의 저장수명이 가장 긴 것으로 나타났다.

2011년에 전국 79개 악취검사기관을 대상으로 공기희석관능법에 대한 숙련도 시험을 실시하였다. 악취방지법의 부지 경계선과 악취 배출원의 배출허용기준을 모사한 2개의 합성복합악취를 숙련도 시험물질(proficiency testing materials, PTM)로 사용 하였다. 부지 경계선 시료는 7ppm의 톨루엔과 7ppm m-자일렌의 복합악취로 구성하였으며, 배출구 시 료는 10ppm DMS (dimethyl sulfide)와 10ppm DMDS (dimethyl disulfide)의 복합악취로 구성하였다. 숙련도 시험 결과는 기준값으로 평균과 중간값을 사용하고, 목표표준편차로 일반 표준편차, 로버스트 표준편차 및 변동계수를 사용하여 Z-점수를 평가하였다. 시험결 과의 변동계수는 PTMs의 냄새강도가 증가함에 따라 감소하였다. 복합악취에 대한 숙련 도 시험 결과는 악취희석배율보다 로그 스케일의 악취지수를 사용하여 평가하는 것이 적 절했다. 두 PTMs에 대한 참여기관의 Z-점수를 변동계수, 표준편차, 그리고 로버스트 표 준편차를 사용하여 평가할 때, 참여기관의 95%가 숙련도 기준을 만족하였다. 목표 표준 편차를 변동계수의 20%로 설정하였을 때 참여기관의 만족도 비율은 부지경계와 출구 PTM 시료에 대해 각각 90%와 95%로 양호하였다. 이러한 결과들로부터 부지경계와 출 구의 복합악취를 모사한 두 합성 PTMs 모두 복합악취의 숙련도 시험물질로 적합하였다.

PTEF membranes are used for roofing materials of membrane structures. PTEF is the abbreviation of Poly-tetra Fluotide-ethylene. These materials are consisted of fiberglass weave and polyetrfluoroethylene coating. Also, PTEF membranes have some problems of structural capacity by wind or snow load, etc. In this study, sensor housings using lead switches are bonding in PTFE membranes, Monitoring to changes tension and tear damages are studied using radio frequency. If tension is received on edged membranes, bonded lead switches of sensor housings will be destroyed by changes tension, and these become to send signals of damages at the connected radio frequency system with increased tension. Study of these functional membrane materials will be contributed to prevent water leakage and long-term maintenance of membrane structures.

Activated carbon (AC) was synthesized from rice husks using the chemical activation method with KOH, NaOH, a combination of (NaOH + Na2CO3), and a combination of (KOH + K2CO3) as the chemical activating reagents. The activated carbon with the highest surface area (around 2000m2/g) and high porosity, which allows the absorption of a large number of ions, was applied as electrode material in electric double layer capacitors (EDLCs). The AC for EDLC electrodes is required to have a high surface area and an optimal pore size distribution; these are important to attain high specific capacitance of the EDLC electrodes. The electrodes were fabricated by compounding the rice husk activated carbons with super-P and mixed with polyvinylidene difluoride (PVDF) at a weight ratio of 83:10:7. AC electrodes and nickel foams were assembled with potassium hydroxide (KOH) solution as the electrolyte. Electrochemical measurements were carried out with a three electrode cell using 6 M KOH as electrolyte and Hg/HgO as the reference electrode. The specific capacitance strongly depends on the pore structure; the highest specific capacitance was 179 F/g, obtained for the AC with the highest specific surface area. Additionally, different activation times, levels of heating, and chemical reagents were used to compare and determine the optimal parameters for obtaining high surface area of the activated carbon.

The characteristics of abrasive wear of the rubber matrix composites filled with nano sized silica particles were investigated at ambient temperature by pin-on-disc friction test. The range of volume fraction of silica particles tested are between 11% to 25%. The cumulative wear volume and friction coefficient of these materials on particle volume fraction were determined experimentally. The major failure mechanisms were lapping layers, deformation of matrix, ploughing, deboding of particles and microcracking by scanning electric microscopy photograph of the tested surface. The cumulative wear volume showed a tendency to increase nonlinear with increase of sliding distance. As increasing the silica particles of these composites indicated higher friction coefficient.

The main cause of building fire fatalities occur in the combustible material heat, smoke and toxic gases are. Building interior decoration, etc., especially as much of the harmful substances generated during combustion, and, used in domestic architecture wallpaper, ceiling, and other plastics, built-in foam insulation also analyzed recognition of fire hazards approach to test the conkalrorimiteo test, choedaeyeolbangchulryul through, chongbal heat, mass loss rate, generates carbon monoxide gas hazard ratio tests, analysis and evaluation rigid foam index testing the toxicity of hazardous material generated by performing a gas clean up and assess the material test results, the minimum order to provide data to quantify the risk of fire. Ensure fire safety of building materials, composite materials in order to test the various risk factors could be considered organic to the introduction of testing and evaluation is needed urgently.

In this study, the property of crack growth in structural steel is investigated according to length and angle of crack at the analysis result of model. Strain energy, deformation and stress obtained by finite element analysis are compared with various configuration of crack. Stress intensity factors as fracture toughness are calculated by the basis of strain energy, deformation and stress. As there are almost no errors by comparing stress intensity factors with those from the standard formula, these calculated factors can be confirmed in order to be applied at real structure. In case cracks or holes at structure are existed, the fatigue damage possibility can be examined by use of this study result.

Developing proper reduction strategies of indoor radon which have been an important issue in Korea requires proper information on source characteristics a phosphate gypsum board which is a common building material used for inter-wall thermal protection in Korea could be a major source of indoor radon level. This study evaluated the correlation between indoor radon concentration and the attribution of gypsum board content in building materials. In this study we valuated indoor/outdoor radon from 58 facilities selected based on the information availability of gypsum content in the building material across 8 different cities in Korea. Our results showed that indoor radon concentrations were 2 to 3 times higher than outdoor but those results were not significantly attributed from gypsum contents in the building material. Indeed, phosphate content in gypsum board did not significantly play a role in indoor radon level variations. It is concluded that physical environmental condition such as temperature, relative humidity, radon exhalation rate out of each building materials, as well as pathway from external sources (e.g., soil) needs to be identified to develop indoor radon reduction strategies.

전도성 고분자는 고분자가 갖는 높은 투과도와 화학적 구조에 의한 전도성 특성, 좋은 가공성, 낮은 가격과 같은 이점 때문에 전자산업, 특히 디스플레이 재료 개발 분야에서 그 응용에 대한 연구가 활발히 진행되고 있다. 전도성 고분자는 산화환원에 의해 다른 상태의 구조를 갖게 되는데, 이때 색변화, 전도도가 변하게 된다. 따라서 이러한 특징을 이용하여 전도성 고분자의 직접적인 색변화를 이용한 전기변색 디스플레이와 전도성 고분자가 갖는 전기전도도를 이용한 디스플레이 재료들의 연구가 이루어지고 있다. 전도성 고분자는 그 종류마다 다른 전도도를 갖게 되는데, 이는 그 고분자를 이루는 물질에 의해 결정되기 때문이며, 또한 doping level, dopant, 중합방법에 따라 전도도의 조절이 가능한 특징이 있다. 최근 전도성 고분자 응용 분야의 대표적인 선도 연구로는 전기변색 디스플레이, 대전방지, 높은 전도도를 이용한 투명전극 응용 등이 있다.