• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2016년도 춘계 학술논문 발표대회
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• pp.26-27
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• 2016

This study is an experiment to know mechanical properties that matrix of the magnesium oxide-based can interior Radon gas absorption and decrease by the addition of Bentonite, Vermiculite, illite having characteristic of the cation-exchange and porous. As a study to examine the possibility was fixed the addition amount of each adsorbent that was added to the 0, 10, 20% of magnesium oxide and magnesium chloride with 25%. Illite, bentonite WB is 45 (wt,%), vermiculite W/B was carried out an experiment to 50 (wt,%).

• 대한기계학회논문집A
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• 제24권6호
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• pp.1456-1469
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• 2000

Mechanical behaviors of uniaxially fiber-reinforced metal matrix composites under transverse loading conditions were studied at room and elevated temperatures. A mono-filament composite was selecte d as a representative analysis model with perfectly bonded fiber/matrix interface assumption. The elastic-plastic and visco-plastic models were investigated by both theoretical and numerical methods. The product of triaxiality factor and effective strain as well as stress components and strain energy was obtained as a function of location to estimate the failure sites in fiber-reinforced metal matrix composite. Results showed that fiber/ matrix interfacial debond plays a key role for local failure at the room temperature, while void creation and growth in addition to the interfacial debond are major concerns at the elevated temperature. It was also shown that there would be an optimal diameter of fiber for the strong fiber-reinforced metal matrix composite.

• BMB Reports
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• 제53권7호
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• pp.349-356
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• 2020

Mass spectrometry (MS) is an ideal tool for analyzing multiple types of (bio)molecular information simultaneously in complex biological systems. In addition, MS provides structural information on targets, and can easily discriminate between true analytes and background. Therefore, imaging mass spectrometry (IMS) enables not only visualization of tissues to give positional information on targets but also allows for molecular analysis of targets by affording the molecular weights. Matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) MS is particularly effective and is generally used for IMS. However, the requirement for an organic matrix raises several limitations that get in the way of accurate and reliable images and hampers imaging of small molecules such as drugs and their metabolites. To overcome these problems, various organic matrix-free LDI IMS systems have been developed, mostly utilizing nanostructured surfaces and inorganic nanoparticles as an alternative to the organic matrix. This minireview highlights and focuses on the progress in organic matrix-free LDI IMS and briefly discusses the use of other IMS techniques such as desorption electrospray ionization, laser ablation electrospray ionization, and secondary ion mass spectrometry.

• 열처리공학회지
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• 제28권5호
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• pp.239-249
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• 2015

Various amount of NbC carbide was intentionally formed in a matrix-type cold-work tool steel by controlled amount of Nb and C addition. And the effect of NbC addition on the mechanical properties was investigated. Four alloys with different Nb and C contents were cast by vacuum induction melting, then hot forging and spheroidizing annealing were conducted. The machinability of the annealed specimens was examined with 3 different cutting tools. And tensile tests at room temperature were conducted. After quenching and tempering, hardness and impact toughness were measured, while wear resistance was evaluated by disk-on-plate type wear test. The increasing amount of NbC addition resulted in degraded machinability with increased strength, whereas the absence of NbC also led to poor machinability due to high toughness. After quenching and tempering, the additional NbC improved wear resistance with increasing hardness, whereas it deteriorated impact toughness. Therefore, it could be found that a moderate addition of NbC was desirable for the balanced combination of mechanical properties.

• Journal of Pharmaceutical Investigation
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• 제31권1호
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• pp.37-41
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• 2001

Various characteristics of polyethylene oxide (PEO) are useful for drug delivery systems. In this study, PEO was used as a sustained release matrix system containing cefatrizine propyleneglycol (Cefa-PG) which is a new semi-synthetic broad-spectrum and orally active cephalosporin. Five kinds of sustained release matrix tablets were formulated with various content of PEO and other ingredients. And three types of matrix tablets were formulated of which compositions were the same but the hardness was different. It was found that PEO content influenced drug release rate. Increasing PEO content, the drug release rate from matrix tablets was decreased. In addition, Avicel, one of the ingredients of matrix components, changed the drug release from the sustained release PEO matrix tablets. With increasing Avicel content, the rate of drug release was increased. For the effect of hardness of matrix tablets, the rate of drug release is decreased with increasing hardness. In comparison of bioavailability parameters after oral administration of Cefa-PG PEO matrix tablets and general Cefa-PG capsule in beagle dog, the sustained release PEO matrix tablets is more useful than a general dosage form. $AUC^{0-12}$ of the sustained release PEO matrix tablet and the general dosage form was 1.16 and 0.644 respectively.

• 환경위생공학
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• 제16권1호
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• pp.91-101
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• 2001

In order to propose a optimum method increasing accuracy and reproducibility in analysis of urine lead levels, we compared matrix modifier addition method and microwave digestion method. The results were as follows ; 1. Where the concentration of $Pd(NO_3)_2$(matrix modifier) was $50mg/{\ell}$, and ashing temperature was $900^{\circ}C$, the results were optimum. In case of matrix modifier addition method, the average coefficient of variation (CV) of normal man was 24.1%, and lead worker was 7.9%. The average urine lead levels of standard were $10.42\mu{g}/{\ell}$ and $19.89\mu{g}/{\ell}$ , the accuracies compared to reference values were 97.0% and 92.6%, respectively. 2. Microwave digestion temperature($160~180^{\circ}C$), time(15~25min) and the ratio of urine/ashing acid(1:1~4:1) did not significantly affect lead absorbance and background absorbance. Therefore we set up a optimum analytical conditions as follows: temperature, $160^{\circ}C$; time, 15min; the ratio of urine/ashing acid, 4:1. after samples were digested by the above analytical conditions, lead absorbance and background absorbance was measured at $450^{\circ}C$ as ashing temperature. The average coefficient of variation (CV) of normal man was 12.4%, and lead worker was 6.2%. The average urine lead levels of standard urine were $10.66\mu{g}/{\ell}$ and $23.31\mu{g}/{\ell}$, the accuracies compared to reference values were 99.3% and 103.9%, respectively. From the results, we suggest that microwave digestion method is a more favorable method than matrix modifier addition method because of easiness to reduce organic matter, possibility to analysis at low temperature and accuracy.

• 한국전기전자재료학회논문지
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• 제20권6호
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• pp.561-565
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• 2007

Because of a good wear resistance and a stable contact resistance, Ag-CdO is widely used as electrical contact material. But, the Cd-oxide mainly exists as a coarse particle and adversely affected to environment. As a reason, $Ag-SnO_2$ alloy has been developed. The Sn-oxide maintains stable and fine particle even at high temperature. In order to investigate the effect of Misch metal (Mm) additional that affects the formation of the oxide and the formation of fine matrix Ag, we studied the microstructures and properties of Ag-Sn-In(-Mm) material fabricated by rapid solidification process. The experimental procedure were melting using high frequency induction, melt spinning, and internal oxidation. The Mm addition makes Ag matrix more fine than no Mm addition. The reason is that the addition of Misch metal decreased a latent heat of fusion of alloy, as a result the rapid solidification effect of alloy is increased. The maximum hardness shows at 0.3 wt%Mm. after that the hardness is decreased until 0.4 wt% Mm, but still larger than no Mm addition alloy. At 0.5 wt% Mm alloy, the precipitation of Misch metal causes a decrease of hardness than no Mm addition alloy.

• 한국주조공학회지
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• 제20권2호
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• pp.89-96
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• 2000

The effects of modification processing on the refinement of primary Si and the wear behavior of hyper-eutectic Al-Si alloys have been mainly investigated. Refining effects of primary Si in Al-17%Si alloy was more efficient than that of B.390 alloy. Optimum condition of getting the finest primary Si microstructure was when AlCuP modifier is added into the melt at $750^{\circ}C$ and held it at $700^{\circ}C$ for 30 minutes. Wear loss in the specimens of as-cast condition decreases as the size of primary Si decreases, in the order of B.390 alloy, B.390 alloy with AlCuP addition, Al-17%Si alloy and Al-17%Si alloy with AlCuP addition. Wear loss in the aged condition of Al-17%Si alloy, B.390 alloy and B.390 alloy with AlCuP addition decreased due to the increase of compressive residual stress in the matrix by the aging treatment. While, wear loss increased in the aged specimens of Al-17%Si alloy with AlCuP addition and Hepworth addition in which compressive residual stress decreases by the aging treatment. Therefore, it is assumed that higher compressive residual stress in the matrix can reduce the wear loss in composite materials such as hyper-eutectic Al-Si alloys.

• 한국융합학회논문지
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• 제4권3호
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• pp.27-33
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• 2013

기존의 바코드는 정보 배열이 나란히 나열된 선 모양을 가지며 이를 1차원 바코드라 부른다. 이에 반해 2차원 바코드는 점자방식 또는 모자이크방식 코드로 작은 정사각형 도는 직사각형 안에 정보를 표현한다. 2차원 바코드는 기존의 1차원 바코드보다 작은 공간에 많은 데이터를 표현 가능함으로써 보다 효율적인 바코드의 구현이 가능하다. 현재 ISO 국제 표준화된 2차원 바코드는 총 4가지로 분류되는데 QR Code, Data Matrix, PDF417, MaxiCode가 있다. 본 논문에서는 ISO 국제 표준화된 바코드 중 하나인 Data Matrix의 Base 256 모드에 대한 기본 개념, 구성 방법, 인코딩 및 디코딩 방법을 상세히 제안한다. Data Matrix 심벌에 저장된 데이터를 보다 효율적으로 구성하기 위해 숫자, Alphanumeric 문자, 이진법에 따라 다른 인코딩, 디코딩 방법을 사용하게 되는데 본 논문에서는 이를 고려한 디코딩 방법에 초점을 맞춰 기술할 것이다.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2014년도 춘계 종합학술대회 논문집
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• pp.71-72
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• 2014