• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 1998년도 가을 학술발표대회 논문집(III)
• /
• pp.779-784
• /
• 1998

The velocity and amplitude of microwaves are affected by the electromagnetic properties of a material through which the wave propagates. And the electromagnetic properties of a dielectric material such as concrete is represented by its permittivity. For the development of an accurate and reliable nondestructive testing (NDT) technique for concrete structures using microwave, it is necessary to have knowledge about the permittivity of concrete. In this paper, mortar specimens are used to serve as a basis for further measurement of concrete. The effect of water on the permittivity was studied using specimens with different water content. To assure the reliability of the measurement results, a statistical method was introduced.

• 한국실내디자인학회논문집
• /
• 제20권1호
• /
• pp.24-32
• /
• 2011

The study was to grasp features of new material applicable to housing space in the sustainable side by analyzing materialistic features of new material and features of sustainable material with sustainable new material. Through analysis on sustainable new material, the study deducted the below conclusion. First, through the precedent studies, the characteristics of sustainable materials have been classified into eight categories : friendly healthiness, non-toxicity, comfortableness, naturality, recycling, harmlessness of environment, separate collection, reusability. After the criteria have been brought up from new material applicable to housing space in the sustainable. Second, in materialistic Characteristics of new material, 'New Process' was mainly applied. There was no any new material applied to 'new raw material'. Therefore, it is thought that it is necessary to study on development of perfectly new material and to study on new material to apply material used in other fields to finishing material of dwelling space. Third, in Characteristics of sustainable material, 'Re-serviceability' appeared most and 'Non-toxicity' and 'Recycling' appeared in the next. 'Friendly Healthiness' and 'Separate collection' appeared only one on the other side. Therefore, it is judged that it is necessary to develop and study new material including health components considering user's health, function for health increase and function to grope comfort for humans. Finally, after researching and analysis the criteria by recently presented the new material, it has been concluded that the standard can be used as the criteria of new material for the possibility of application in housing space. On the basis of the study, the author will carry out analysis on sustainable new material minutely and utilize it as basic data to suggest a standard of sustainable new material applicable to dwelling space in the future.

• 박물관보존과학
• /
• 제1권
• /
• pp.53-59
• /
• 1999

조선시대 나전칠기함(유물번호 : 덕4182) 상태조사 중에 발견한 백골(白骨)의 모서리 보강재(補强材)에 대한 잔존지방산(殘存脂肪酸) 분석(分析)을 실시하였다 그 결과 콜레스테롤의 함량이 높아 동물성 재료임을 확인할 수 있었고, 가스크로마토그라프 분석을 통해 그 지방산 조성(組成)이 상어가죽[교피(鮫皮)]과 유사한 패턴을 보임을 알 수 있었다. 이 분석결과에 따라 나전칠기함의 손상된 보강재를 새로운 상어가죽으로 대체(代替) 복원(復元)하였다.

• Advances in materials Research
• /
• 제6권1호
• /
• pp.45-63
• /
• 2017

In this article, static deflection and buckling of functionally graded (FG) nanoscale beams made of porous material are carried out based on the nonlocal Timoshenko beam model which captures the small scale influences. The exact position of neutral axis is fixed, to eliminate the stretching and bending coupling due to the unsymmetrical material change along the FG nanobeams thickness. The material properties of FG beam are graded through the thickness on the basis of the power-law form, which is modified to approximate the material properties with two models of porosity phases. By employing Hamilton's principle, the nonlocal governing equations of FG nanobeams are obtained and solved analytically for simply-supported boundary conditions via the Navier-type procedure. Numerical results for deflection and buckling of FG nanoscale beams are presented and validated with those existing in the literature. The influences of small scale parameter, power law index, porosity distribution and slenderness ratio on the static and stability responses of the FG nanobeams are all explored.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2000년도 추계학술대회 논문집
• /
• pp.281-284
• /
• 2000

For estimation manufacturing cost during the early design stage, desingers have to know compositon of manufacturmg cost. Manufacturing cost is summalion of material cost and processmg cost. To be able to control the manufacturmg cost, it is necessary to estimate the costs adequately and to store the cost data in a generic way. a generic system, which is the basis for the control of the production costs, takes into account geometric information, material information, process information and production planning information Manufacturing cost is summation of material cost and processing cost.

• International Journal of Railway
• /
• 제5권1호
• /
• pp.22-28
• /
• 2012

This report is devoted to the problems of Mongolian Railway Transportation Safety such as high length of wagon service life, defects due to the more factors of exploitation, idle time, increase of faults, poor condition of repairing shops and more hand and mechanical operations and these conditions are quite difficult to meet the safety and reliability of increasing transportation from day to day. The paper discusses that the most optimum solution is diagnosing before occurring wear, breakdown, and defects on the basis of studying characteristics of structural material breakdown, residual methods of voltage, effects of material hardness and linear defects of a crystal net and the reform of machines is very important to implement it. It focuses the structures, characteristics of the material transportation and tests and analyses of the wagon cart which has to meet the traffic safety of wagons and slow and soft movement. The study is done on the wagon chassis which has to meet the traffic safety of luggage wagons.

• International Journal of Precision Engineering and Manufacturing
• /
• 제7권2호
• /
• pp.52-55
• /
• 2006

The OLEDs(Organic Light-Emitting Diodes) structure organizes the bottom layer using glass, ITO(indium thin oxide), hole injection layer, hole transport layer, emitting material layer, electron transport layer, electron injection layer and cathode using metal. OLED has various advantages. OLEDs research has been divided into structural side and emitting material side. The amount of emitting light and luminescence efficiency has been improved by continuing effort for emitting material layer. The emitting light mechanism of OLEDs consists of electrons and holes injected from cathode and anode recombination in emitting material layer. The mobilities of injected electrons and holes are different. The mobility of holes is faster than that of electrons. In order to get high luminescence efficiency by recombine electrons and holes, the balance of their mobility must be set. The more complex thin film structure of OLED becomes, the more understanding about physical phenomenon in each interface is needed. This paper observed what the thickness change of hole transport layer has an affection through the below experiments. Moreover, this paper uses numerical analysis about carrier transport layer thickness change on the basis of these experimental results that agree with simulation results.

• 대한기계학회논문집
• /
• 제6권3호
• /
• pp.204-210
• /
• 1982

The mechanical behaviors of an elastic body containing another materials are studied with the statistical method since they are generally distributed at random in size, orientation, and position. As the basis of this research, the size, the shape, and the ratio of volume for another material assumed to be constant, and only the positions of another material are changed randomly. The stress intensity factor, the compliance, and the modulus of elasticity are investigated in two-dimensional state by using the Monte Carlo Method and the Finite Element Method. The methodology of the simulation analysis for the mechanical behavior of such material is also proposed.

• 한국농공학회지
• /
• 제43권6호
• /
• pp.143-153
• /
• 2001

Hog manure amended with sawdust (moisture 56~60% wet basis, C/N 19-21) was composted in pilot-scale vessels using continuous aeration(CA) and intermittent aeration(IA) for 3 and 4 weeks. In two subsequent runs of the same duration, composts resulting from each of the first runs were used as a biofilter on the exhaust gas from newly composting material. Conditions between each of these paired sets appeared to be similar. Ammonia was released from the biofilter material during the first week of stabilization while the compost produced ammonia after the first week of composting. In both cases substantial absorption, 61~96 %, of ammonia production from the composting raw material was achieved in the stabilizing material during the final weeks of operation and indicates the use of the stabilizing hog manure/sawdust compost as a biofilter can reduce ammonia emissions. Total $NH_3-N$ emissions during run 2 in IA was less than 2/3 of those in CA. Dry solids loss for the stabilized compost (6~8 weeks) was 19~46%.

• 한국분말재료학회지
• /
• 제21권3호
• /
• pp.235-240
• /
• 2014

The basis of the cobalt demand analysis by use was established via the investigation and analysis of the cobalt materials flow, and the overall cobalt metal material and parts industry structure in Korea was examined to determine the cobalt material flow. The markets of the cobalt material for machinery were studied, including their interrelations, via market and study trends, and relevant plans were examined. The results of the study indicated that the advanced core technology for advanced industry and technology-intensive industry development is required to structurally innovate the parts materials and basic materials industries and to upgrade the catch-up industry structure to the new frontier structure.