• 제목/요약/키워드: minimal surface

검색결과 419건 처리시간 0.026초

Analysis of Flavor Composition of Coriander Seeds by Headspace Mulberry Paper Bag Micro-Solid Phase Extraction

  • Cha, Eun-Ju;Won, Mi-Mi;Lee, Dong-Sun
    • Bulletin of the Korean Chemical Society
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    • 제30권11호
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    • pp.2675-2679
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    • 2009
  • This paper reports the example of headspace mulberry paper bag micro solid phase extraction (HS-MPB-$\mu$-SPE) as a new sampling method for the determination of volatile flavor composition of coriander seeds. Adsorption efficiencies between two configurations of mulberry paper bag were compared, and several parameters affecting the HS-MPB-$\mu$-SPE were investigated and optimized. The optimized technique uses an adsorbent (Tenax TA, 0.1 mg) contained in a mulberry paper bag of front configuration where fine surface was outside, and minimal amount of organic solvent (0.6 mL). Linalool and $\gamma$-terpinene were found as abundant flavor compounds from coriander seeds. The limit of detection (LOD) and the limit of quantitation (LOQ) for linalool of major flavor in coriander seeds were 10.3 ng/mL and 34.4 ng/mL, respectively. The proposed method showed good reproducibility and good recovery. The HS-MPB-$\mu$-SPE is very simple to use, inexpensive, requires small sample amounts and solvent consumption. Because the solvent for extraction is reduced to only a very small volume, there is minimal waste or exposure to toxic organic solvent and no further concentration step.

라플라스 모세관이론과 수학물리학의 태동 (Theory of Capillarity of Laplace and birth of Mathematical physics)

  • 이호중
    • 한국수학사학회지
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    • 제21권3호
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    • pp.1-30
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    • 2008
  • 뉴턴의 중력이론의 성공은 수학물리학을 태동시키는 바, 최초로 19세기 초의 분자력의 모델성립에 중요한 요소로 등장하였다. 라플라스는 여기서 회전타원체의 작용이라는 모델을 이용하였고 회전타원체의 작용은 이계편미분방정식으로 표현이 되었다. 이것을 풀어서 유체를 담은 용기의 기하학적 모습과 와 유체와 고체의 접촉각에 대응시켰다. 알 수 없는 분자간거리는 추상적이고 미지의 힘 함수 $\varphi(f)$를 써서 표현하여, 분자 작용반경이라는 개념을 도입하여 이론적인 포텐셜 함수의 이론적인 토대를 구축하였다. 뉴턴의 중력이론은 라플라스이론에서 완성을 이루었고, 이후 분자력의 모델로서 작용을 하였다. 라플라스-영의 모세관이론은 수학적으로는 극소 곡면론에서 물리학적으로는 표면장력현상으로 설명이 된다.

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한지의 특성을 이용한 웨딩드레스 소재 연구: 미니멀 웨딩드레스 제작을 중심으로 (A Study of Wedding Dress Materials Using the Characteristics of Hanji: Focusing on Making Minimal Wedding Dresses)

  • 이지현;간호섭
    • 패션비즈니스
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    • 제25권1호
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    • pp.80-95
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    • 2021
  • In the modern fashion industry, the application of different materials along with an emotional design is emerging as an important factor stimulating consumer sentiment. This has led to the diversity of materials and continued active research on materials. Traditional Korean paper is expressed in various ways in the field of visual arts based on Korean sentiment and unique formative characteristics. Hanji costumes have been produced in various ways over the past 20 years utilizing Hanji's physical characteristics, showing unique surface texture and various techniques that differentiate them from existing fabrics, making it symbolic in expanding the area of fashion materials. In this work, various techniques were developed by utilizing the nonwoven characteristics and excellent variability of Hanji while considering visual images, focusing on the delicate decorations and materialistic representations of wedding dresses. In addition, minimal wedding dresses with unique textures were produced to realize fantasy ideas and show surface aesthetics, confirming as a fashion material different from that of existing wedding dresses. The direction of high value-added creation for the industrialization and globalization of Hanji wedding dresses was presented, and the usefulness and scalability of Hanji materials for practical and industrialization were identified in materials that expressed visual art. To in the fashion industry, which is changing in both the wedding industry and the global market, the development of materials with high sensitivity images and original and solid identity should continue.

High System Performance with Plasmonic Waveguides and Functional Devices

  • Kwong, Wing-Ying
    • ETRI Journal
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    • 제32권2호
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    • pp.319-326
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    • 2010
  • Photonics offers a solution to data communication between logic devices in computing systems; however, the integration of photonic components into electronic chips is rather limited due to their size incompatibility. Dimensions of photonic components are therefore being forced to be scaled down dramatically to achieve a much higher system performance. To integrate these nano-photonic components, surface plasmon-polaritons and/or energy transfer mechanisms are used to form plasmonic chips. In this paper, the operating principle of plasmonic waveguide devices is reviewed within the mid-infrared spectral region at the 2 ${\mu}m$ to 5 ${\mu}m$ range, including lossless signal propagation by introducing gain. Experimental results demonstrate that these plasmonic devices, of sizes approximately half of the operating free-space wavelengths, require less gain to achieve lossless propagation. Through optimization of device performance by means of methods such as the use of new plasmonic waveguide materials that exhibit a much lower minimal loss value, these plasmonic devices can significantly impact electronic systems used in data communications, signal processing, and sensors industries.

변형된 안검봉합술 (Modified Temporary Tarsorrhaphy)

  • 우흥명
    • 한국임상수의학회지
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    • 제16권1호
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    • pp.189-192
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    • 1999
  • Tarsorrhaphy is widely used to protect the cornea, reduce evaporation of tears, and facilitate reepithelialization of the ocular surface. However, a dilemma ensues in patients when frequent neurological evaluations and postoperative examinations are needed. The modified temporary tarsorrhaphy in this study was simple to perform, provided stable eyelid closure, and could be opened and closed as needed. It could be easily reversed with minimal complications of the eyelid and it allowed the surgeon to control traction of the bolsters in all of 45 dogs with corneal epithelial defects. Also, The globe could be examined without further anesthesia, sutures, and pain at any time after surgery. It was concluded that this modified method might be effective for evaluation of the corneal healing process and useful for ocular surface reconstruction clinically.

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실시간 곡면 가공에 관한 제어 알고리즘 및 하드웨어 연구 (Realtime control algorithm and hardware for machining curved surfaces)

  • 정승권;권욱현
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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    • pp.1320-1323
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    • 1996
  • This paper describes an interpolation method for a parametric surface. A parametric surface is approximated to triangular mesh surfaces and then the basic paths are achieved. As the generated path is a series of linear segments, this algorithm can be easily adapted to general NC controllers. The generated paths have minimal transfer length and are gouge-free within the approximation tolerance. The problems, induced when the paths are represented by linear segments, are overcome without making any path deviation by this algorithm. This algorithm saves machining time by eliminating overdetermined tool paths and keeping the desired average feedrate, which improve productivity and lead to lower production costs.

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공구간섭과 절삭성을 고려한 자유 곡면의 4, 5축 NC 가공을 위한 공구 경로 산출 (Interference-Free Tool Path with High Machinability for 4- and 5-Axes NC Machining of Free-Formed Surfaces)

  • 강재관
    • 한국정밀공학회지
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    • 제15권2호
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    • pp.146-153
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    • 1998
  • NC machines with 4 or 5 axes are capable of various tool approach motions, which makes interference-free and high machinablity machining possible. This paper deals with how to integrate these two advantages (interference-free and high machinability machining) in multi-axes NC machining with a ball-end mill. Feasible tool approach region at a point on a surface is first computed, then among which an approach direction is determined so as to minimize the cutting force required. Tool and spindle volumes are considered in computing the feasible tool approach region, and the computing time is improved by trans-forming surface patches into minimal enclosing spheres. A cutting force prediction model is used for estimating the cutting force. The algorithm is developed so as to be applied to 4- or 5-axes NC machining in common.

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임의의 구멍을 포함하는 B-Spline 곡면상에서의 자동 삼각 요소망 생성 (Automatic Triangular Mesh Generation Over B-Spline Surfaces Including Arbitrary Holes)

  • 김근호;양현익
    • 한국CDE학회논문집
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    • 제9권1호
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    • pp.1-10
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    • 2004
  • In the process of finite element analysis, mesh generation is tedious job which consumes tremendous time. Therefore, the automation of well shaped mesh generation from the minimal boundary input data is desirable to improve reliability and accuracy of the analysis and also to reduce the process time of the entire design process. The automation of triangular mesh generation has been relatively well treated due to its robustness and ease of handling when compared to rectangular element mesh generation. In this study, the offset method developed previously for generating plane rectangular element mesh has been corrected and modified to generate triangular element mesh on the B-spline surface having arbitrary holes. The result shows that the generated triangular mesh has the average aspect ratio over 0.9. The designed arbitrary surface shape has been interactively constructed by non-uniform B-spline theory for triangular mesh generation.

Encapsulation of Flavors by Molecular Inclusion Using $\beta$-Cyclodextrin: Comparison with Spray-drying Process Using Carbohydrate-based Wall Materials

  • Cho, Young-Hee;Park, Ji-Yong
    • Food Science and Biotechnology
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    • 제18권1호
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    • pp.185-189
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    • 2009
  • Microencapsulation of flavor was carried out by molecular inclusion process using $\beta$-cyclodextrin (${\beta}CD$). ${\beta}CD$-flavor complex was prepared at various flavor-to-${\beta}CD$ ratios (1:6-1:12) to determine the effect of ${\beta}CD$ concentration on the inclusion efficiency. Maximum total oil retention and minimal surface oil content were obtained at flavors to ${\beta}CD$ ratio of 1:10. The physical properties and controlled release pattern of flavors from ${\beta}CD$-flavor complex were measured and compared with spray-dried microcapsules prepared using carbohydrate wall system. ${\beta}CD$-flavor complex showed higher total oil retention and surface oil contents, smaller mean particle size, lower moisture uptake, and higher oxidation stability than spray-dried microcapsule. Oxidative stability of flavor was correlated with hygroscopicity of wall materials. The controlled release mechanism was highly affected by temperature and characteristics of wall materials.

On the Trajectory Null Scrolls in 3-Dimensional Minkowski Space-Time E13

  • Ersoy, Soley;Tosun, Murat
    • Kyungpook Mathematical Journal
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    • 제48권1호
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    • pp.81-92
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    • 2008
  • In this paper, the trajectory scroll in 3-dimensional Minkowski space-time $E_1^3$ is given by a firmly connected oriented line moving with Cartan frame along curve. Some theorems and results between curvatures of base curve and distribution parameter of this surface are obtained. Moreover, some theorems and results related to being developable and minimal of this surface are given. And also, some relationships among geodesic curvature, geodesic torsion and the curvatures of base curve of trajectory scroll are found.