• Title/Summary/Keyword: mesh 크기

Search Result 393, Processing Time 0.028 seconds

Impact of Mesh Size Difference on Zooplankton Distribution Data and Community Interpretation (망목 크기가 동물플랑크톤 분포 자료 및 군집해석에 미치는 영향)

  • Lee, Pyung-Gang;Park, Chul
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
    • /
    • v.9 no.1
    • /
    • pp.13-19
    • /
    • 2004
  • We compared two different zooplankton data sets simultaneously obtained at the same place with different mesh-sized nets. Smaller mesh-sized net yielded less diverse zooplankton taxa. However, it was difficult to generalize the relationship between the size of the mesh of the net used and the length of the species list observed. It was not only because the sample sizes obtained by smaller mesh net were relatively smaller due to the clogging problem but also because smaller mesh net usually collected more tiny animals that were difficult to identify at lower taxonomic categories. In terms of abundances, on the other hand, the smaller and the larger mesh-sized nets collected smaller and larger-sized animals more effectively, respectively. The abundances of small sized animals were usually greater than those of large-sized animals by about an order of differences. Due to this different catchability of the nets, the community analyses based on Principal Component Analysis led to different results for the same community.

Effect of Morphology and Granule Size of Crystalline D-Sorbitol on Texture of Sugar-Free Chewing Gum (결정형 솔비톨의 형태 및 입자 크기가 무설탕 츄잉껌의 텍스쳐에 미치는 영향)

  • Kim, Sang-Yong;Oh, Deok-Kun
    • Korean Journal of Food Science and Technology
    • /
    • v.29 no.5
    • /
    • pp.987-991
    • /
    • 1997
  • Effect of morphology and granule size of crystalline D-sorbitol on texture of sugar-free chewing gum was investigated with different morphology of sorbitol such as a compact shaped P-type and a loose shaped S-type, and with different granule size such as 50 mesh, 80 mesh, and 100 mesh. The chewing gum including S-type sorbitol exhibited an increased flexibility and a decreased hardness as compared with that including P-type sorbitol. S-type sorbitol was chosen as a solid phase of sugar-free chewing gum because the consumer preferred a chewing gum with high flexibility and low hardness. The flexibility and hardness of chewing gum including S-type sorbitol were determined to be optimum at 80 mesh of the sorbitol size. The flexibility of the chewing gum including 80 mesh S-type sorbitol increased but the hardness decreased with increasing temperature.

  • PDF

Numerical Study on Effect of Mesh Size on Vibration and Overpressure Propagation Induced by Underwater Blasting (수중발파로 인한 과압 및 진동 전파에서 메쉬크기의 영향에 대한 수치해석 연구)

  • Jeong, Hoyoung;Son, Hanam;Kim, Suhan;Kim, Yeolwoo
    • Tunnel and Underground Space
    • /
    • v.31 no.6
    • /
    • pp.578-592
    • /
    • 2021
  • This study performed to investigate the propagation characteristics of overpressure, impulse, vibration in underwater blasting. The difference between air blasting and underwater blasting is that noise and vibration propagate through water as a medium. In some cases, the noise and vibration propagates through various media (rock, water, air, etc.). In this study, the underwater blasting was simulated using AUTODYN, and the propagation characteristics of overpressure, impulse and vibration induced by blasting were analyzed. We mainly focused on the effect of mesh size on the overpressure, impulse and peak particle velocity from the underwater blasting simulation. The numerical results indicated that the overpressure and peak particle velocity tended to decrease as the mesh size increased, while the impulse increased with the mesh size. The results also indicated that the mesh dependence varied depending on the explosive charge and scaled distance.

THE EFFECT OF INCINERATED TOOTH PARTICLES ON OSTEOGENESIS ACCORDING TO PARTICLE SIZE (치아회분의 입자 크기에 따른 골형성에 대한 영향)

  • Lee, Kyu-Chil;Yoon, Chang-Keun
    • The Journal of Korean Academy of Prosthodontics
    • /
    • v.25 no.1
    • /
    • pp.355-362
    • /
    • 1987
  • 본 실험의 목적은 치아 회분이 입자 크기에 따라 골형성에 어떠한 영향을 주며 순수 합성수산화 apatite인 calcitite와는 어떠한 차이가 있는가를 평가하기 위하여 수행하였다. 이를 위하여 200mesh와 40mesh의 치아 회분말과 40mesh calcitite를 잡종견의 신선한 발치와에 매식후 1주, 2주, 3주, 4주에 각각 희생하여 임상, X-선상 및 현미경적으로 관찰한 바 다음과 같은 결론을 얻었다. 1. 모든 경우에 조직의 거부반응이 없었다. 2. 40mesh치아 회분의 경우가 200mesh의 치아회분의 경우 보다 골 형성 능력이 현저히 높았다. 3. 40 mesh 치아회분과 calcitite 모두 비교군에 비하여 골 형성이 지연되었다. 4. 40 mesh 치아 회분과 calcitite의 골 형성 능력은 유사하였다.

  • PDF

그래핀 합성 및 TEM grid막으로의 응용

  • Lee, Byeong-Ju;Jeong, Gu-Hwan
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2011.02a
    • /
    • pp.461-461
    • /
    • 2011
  • 최근의 나노기술의 발전과 함께 나노미터크기의 물질들의 물성과 미세구조 등을 분석하기 위한 노력들이 활발히 이루어지고 있다. 투과전자현미경(transmission electron microscope; TEM)은 나노물질의 미세구조 관찰, 화학성분 분석, 전자기적 특성평가가 가능한 초정밀 분석장비이다. TEM 관찰을 위한 시편의 제작방법중 TEM 그리드(grid)를 사용하는 방법은, 분석하고자 하는 물질을 망(mesh) 형태의 그리드에 도포하여 샘플을 준비하는 방법으로 다른 방법에 비해 아주 빠르고 간편한 장점이 있다. 그러나 TEM 그리드에 나노물질을 분산/도포하여 공중에 떠있는 형태로 샘플을 제작하려면, 나노물질이 mesh 사이로 빠져나오지 않도록 그리드 mesh의 간격이 아주 미세하여야 하는데, 일반적으로 mesh의 크기가 미세할수록 그리드의 가격은 높아진다. 또한 기존에 사용되고 있는 비정질 탄소박막으로 덮여진 그리드는 극미세 크기의 나노물질 및 탄소나노물질을 분석할 경우, 고해상도의 TEM상을 얻는데 한계가 있다. 한편 그래핀은 2차원의 육각판상의 구조로 탄소원자가 빼곡히 채워진 흑연 한 층의 나노재료이다. 이는 원자단위 두께로 가장 얇은 물질로서 기계적 강도가 우수하여 지지막으로의 응용이 가능하다고 알려져 있다. 따라서 TEM grid막으로 사용할 경우 기존의 고가의 미세한 mesh가 형성된 그리드를 사용하지 않아도 나노물질을 효과적으로 분석할 수 있을 것으로 예상 된다. 본 연구에서는 열화학증기증착법(thermal chemical vapor deposition; TCVD)을 이용하여 300 nm 두께의 니켈박막이 증착된 기판위에 대면적으로 합성한 그래핀을 TEM 관찰용 그리드 위에 전사(transfer)함으로써 나노물질이 그리드 mesh사이로 빠져나오지 않는 저가의 TEM 그리드 제작 방법 및 응용 가능성에 대하여 보고한다.

  • PDF

Effect of Different Milling Methods on Distribution of Particle Size of Rice Flours (제분방법이 쌀가루의 입자크기에 미치는 영향)

  • Kum, Jun-Seok;Lee, Sang-Hyo;Lee, Hyun-Yu;Kim, Kil-Hwan;Kim, Young-In
    • Korean Journal of Food Science and Technology
    • /
    • v.25 no.5
    • /
    • pp.541-545
    • /
    • 1993
  • Two different methods (Sieve shaker, Elzone particle size analyzer) were used to investigate rice flour particle size obtained by various milling method. Results of Elzone particle size analyzer were more effective than Sieve shaker in determining particle size, and the distribution of particle size of rice flours was affected by the type of the milling methods used. A rice flour, prepared in a Pin mill had a particle size range of $60{\sim}500$ mesh, and 30.38% of the sample was in the particle size range $200{\sim}270$ mesh. A rice flour, prepared in a Colloid mill had a particle size range of $40{\sim}500$ mesh and more of flour particles appeared in the range $140{\sim}200$ mesh than any other particle size. A rice flour, prepared in a Micro mill had a particle size range of $140{\sim}500$ mesh, and 41.62% of the sample was in the particle size range over 500 mesh. A rife flour, prepared in a Jet mill had a finer flour particle size was over the particle size range 500 mesh. The finer rice flour gave the highest L value and the lowest a value. The wet-milled flour particles were observed as a cluster of starch granules and the particles of rice flour (dry-milling) were observed as fragment of rice grains. Scanning Electron Photomicrographs revealed that visual differences in structure between milling methods, and similar results with Elzone particle size analyzer method in particle size.

  • PDF

A Study on Grid Size and Generation Method for Fire Simulations for Ship Accommodation Areas (선박 거주구역 화재시뮬레이션을 위한 격자크기와 생성방법에 관한 연구)

  • Kim, Byeol;Hwang, Kwang-Il
    • Journal of the Korean Society of Marine Environment & Safety
    • /
    • v.23 no.7
    • /
    • pp.791-800
    • /
    • 2017
  • For fires in ship accommodation areas, if it is possible to predict the pattern in which fire will spread and suggest proper countermeasures according to a situation using a fire simulation tool, fire damage may be reduced. However, fire simulations have a practical limit: a significant amount of time is required to analyze the results due to the size of the computational domain and the number of grids. Therefore, in this study, applicable grid size for fire simulations to predict fire patterns in ship accommodation areas was analyzed, and a generation method was conducted to predict fire behavior in real time. As a result, a value within 0.25[m] was judged appropriate as an applicable grid size for ship accommodation areas. Also, in comparison with studies using a single mesh generation method, the visibility value was similar, within 4.3 %, as was the temperature value, within 8.3 %, when a multi mesh generation method was used, showing a decline of 80 % in analysis time. Therefore, it was confirmed that composing a grid using multi mesh was effective for reducing analysis time.

Effect of Particle Size and Mixing Ratio on Quality of Fluidized Coated Vitamin C (입자크기와 혼합비에 따른 유동층 코팅 비타민 C의 품질 특성)

  • Park, Su-Jung;Hwang, Sung-Hee;Chung, Hun-Sik;Youn, Kwang-Sup
    • Food Science and Preservation
    • /
    • v.14 no.4
    • /
    • pp.364-368
    • /
    • 2007
  • The purpose of this study was to improve the stability and the processing property of vitamin C. Vitamin C was coated according to particle size(80-100 mesh, 100-140 mesh) and mixing ratio(1:1.6, 1:2.5, 1:3(w/w)) with coating solution(8% Zein-DP, 6% HPMC-FCC), and then the quality characteristics of fluidized bed micro coated vitamin C were investigated. The coating efficiency and the thickness of coating film were higher in $80{\sim}100$ mesh particle than in $100{\sim}140$ mesh particles, and coating efficiency was decreased as the coating material was increased. The distribution range of particle was more narrow in mixing ratio of 1:3(w/w) than in the other. DPPH radical scavenging activity was not affected by the particle size and the mixing ratio. There was no difference between the coating materials in terms of the quality characteristics. The optimum coating condition for fluidized bed micro-coating of vitamin C powder was selected as the particle size of $80{\sim}100$ mesh and the mixing ratio with coating solution of 1:3(w/w).

Motion Estimation Using Dynamic Regular Mesh (동적 정규화 메쉬를 이용한 움직임 추정)

  • Lee, Dong-Gyu;Lee, Du-Su
    • Journal of the Institute of Electronics Engineers of Korea SP
    • /
    • v.38 no.6
    • /
    • pp.599-607
    • /
    • 2001
  • In Conventional BMA, the motion vector can describe only translational movement and blocking noise is generated. To overcome this defect, motion estimation using triangular mesh has been proposed. The regular mesh is the method of dividing the image area into equal size triangle and haying the same node connection. It has no additional information about mesh structure, but do not reflect the real motion because it represents the regions by equal mesh structure regardless of the amount of motion. In this paper, motion estimation using dynamic regular mesh is proposed, In this method, the mesh structure is varied from the amount of motion and maintain the form of regular mesh. By the simulation, proposed method have better performance in PSNR and is superior to the other method in convergence rate.

  • PDF

Embedding a Mesh of Size 2n ×2m Into a Twisted Cube (크기 2n ×2m인 메쉬의 꼬인 큐브에 대한 임베딩)

  • Kim, Sook-Yeon
    • The KIPS Transactions:PartA
    • /
    • v.16A no.4
    • /
    • pp.223-226
    • /
    • 2009
  • The twisted cube has received great attention as an interconnection network of parallel systems because it has several superior properties, especially in diameter, to the hypercube. It was recently known that, for even m, a mesh of size $2{\times}2^m$ can be embedded into a twisted cube with dilation 1 and expansion 1 and a mesh of size $4{\times}2^m$ with dilation 1 and expansion 2 [Lai and Tsai, 2008]. However, as we know, it has been a conjecture that a mesh with more than eight rows and columns can be embedded into a twisted cube with dilation 1. In this paper, we show that a mesh of size $2^n{\times}2^m$ can be embedded into a twisted cube with dilation 1 and expansion $2^{n-1}$ for even m and with dilation 1 and expansion $2^n$ for odd m where $1{\leq}n{\leq}m$.