• Title/Summary/Keyword: 원추형태

Search Result 111, Processing Time 0.025 seconds

Ultrastructure of the Midgut Epithelial Cells in the Mosquito Larvae, Anopheles sinensis Wiedemann (중국얼룩날개모기 유충내에 있는 중장 상피세포들의 미세구조)

  • Yu, Chai-Hyeock
    • Applied Microscopy
    • /
    • v.34 no.3
    • /
    • pp.199-209
    • /
    • 2004
  • The migut epitheluim of the last instar larva in the mosquito larvae, Anopheles sinensis was observed with electron microscopes. The midgut epitheluim of the mosquito larva is composed of a single-layered columnar absorptive cells, regenerative cells and secretory granular cells. The free surface of the columnar absorptive cells has a regular array of microvilli 'brush border', while cell membranes close to the basal lamina are extrmely infolded and a lot of mitochondria are concentrated in those processes. The columnar absorptive cells also contain cell organelles expected to be found in absorptive cell. Midgut regenerative cells which are positioned basally in the epithelium form the groups, which are called 'nidi', composed of 1 or $2{\sim}3$ cells, they show darker appearance than the columnar absoptive cells. The secretory granular cells contain numerous electron dense granules, $200{\sim}400$ nm in diameter. The cone shaped secretory granular cells are located in the basal portion of the midgut epitheluim. The epithelium is surrounded by the subepithelial space and muscle bundles. The subepithelial space, which is filled with fibrous connective tissue, is innervated by many axon cells and tracheoles.

Taxonomy of tribe Neillieae (Rosaceae): Neillia (나도국수나무족(장미과)의 분류: 나도국수나무속)

  • Oh, Sang-Hun
    • Korean Journal of Plant Taxonomy
    • /
    • v.46 no.1
    • /
    • pp.13-32
    • /
    • 2016
  • Neillieae was traditionally recognized as a small tribe in Rosaceae, which consists of Neillia, Stephanandra, and Physocarpus. Recently, Stephanandra was merged into Neillia based on molecular phylogenetic analyses, meaning that Neillieae now contains Neillia and Physocarpus. The genus Neillia is distinguished from Physocarpus by ovate to lanceolate leaves with acuminate to caudate apices, racemose or paniculate inflorescences, and a unicarpellate (rarely bicarpellate) gynoecium. Plants of Neillia are distributed from the Himalayas across China and Korea to Japan in the east, and south to Indonesia. This study provides a taxonomic treatment of Neillia based on a morphological examination of herbarium specimens, including types, and field observations, as the second part of the taxonomic revision of the tribe Neillieae. A summary of the phylogeny of Neillia, keys to the species, nomenclatural reviews, descriptions, distribution maps, and lists of specimens examined are provided. Twelve species with ten varieties are recognized in Neillia. A lectotype was designated here for the following species: N. sinensis f. glanduligera and N. thyrsiflora.

Three-Dimensional Vibration Analysis of Thick Shells of Revolution (두꺼운 축대칭 회전쉘의 3차원적 진동해석)

  • 강재훈;양근혁;장경호
    • Journal of the Computational Structural Engineering Institute of Korea
    • /
    • v.15 no.3
    • /
    • pp.399-407
    • /
    • 2002
  • A three-dimensional method of analysis is presented for determining the free vibration frequencies and mode shapes of hollow bodies of revolution (i.e., thick shells), not limited to straight line generators or constant thickness. The middle surface of the shell may have arbitrary curvatures, and the wall thickness may vary arbitrarily. Displacement components$U_\Phi, U_z, U_\theta$ in the meridional, normal and circumferential directions, respectively, are taken to be sinusoidal in time, periodic in$\theta$, and algebraic polynomials in the$\Phi$and z directions. Potential(strain) and kinetic energies of the entire body are formulated, and upper bound values of the frequencies are obtained by minimizing the frequencies. As the degrees of the polynomials are increased, frequencies converge to the exact values. Novel numerical results are presented for two types of thick conical shells and thick spherical shell segments having linear thickness variations. Convergence to four digit exactitude is demonstrated for the first five frequencies of both types of shells. The method is applicable to thin shells, as well as thick and very thick ones.

A Study on Microfailure Mechanism of Single-Fiber Composites using Tensile/Compressive Broutman Fragmentation Techniques and Acoustic Emission (인장/압축 Broutman Fragmentation시험법과 음향방출을 이용한 단섬유 복합재료의 미세파괴 메커니즘의 연구)

  • Park, Joung-Man;Kim, Jin-Won;Yoon, Dong-Jin
    • Composites Research
    • /
    • v.13 no.4
    • /
    • pp.54-66
    • /
    • 2000
  • Interfacial and microfailure properties of carbon fiber/epoxy matrix composites were evaluated using both tensile fragmentation and compressive Broutman tests with an aid of acoustic emission (AE) monitoring. A polymeric maleic anhydride coupling agent and a monomeric amino-silane coupling agent were used via the electrodeposition (ED) and the dipping applications, respectively. Both coupling agents exhibited significant improvements in interfacial shear strength (IFSS) compared to the untreated case under tensile and compressive tests. The typical microfailure modes including fiber break of cone-shape, matrix cracking, and partial interlayer failure were observed during tensile test, whereas the diagonal slippage in fiber ends was observed under compressive test. For both loading types, fiber breaks occurred around just before and after yielding point. In both the untreated and treated cases AE amplitudes were separately distributed for the tensile testing, whereas they were closely distributed for the compressive tests. It is because of the difference in failure energies of carbon fiber between tensile and compressive loading. The maximum AE voltage for the waveform of carbon or basalt fiber breakages under tensile tests exhibited much larger than those under compressive tests, which can provide the difference in the failure energy of the individual failure processes.

  • PDF

Spray Characteristics of Supersonic Liquid Jet by a Nozzle Geometry of Miniature High-Pressure Injection System (축소형 초고압 분사 시스템의 노즐 형상에 따른 초음속 액체 제트 분무 특성에 관한 연구)

  • Shin, Jeung-Hwan;Lee, In-Chul;Kim, Heuy-Dong;Koo, Ja-Ye
    • Proceedings of the Korean Society of Propulsion Engineers Conference
    • /
    • 2010.11a
    • /
    • pp.177-180
    • /
    • 2010
  • Two-stage light gas gun, sorted with Ballistic Range System, is used to research spray characteristics of supersonic liquid jets. When high pressure tube was pressurized to the 135 bar, diaphragm films which composed with OHP film are ruptured. Expansion gases accelerate a projectile approximately 250 m/s at the exit of pump tube. And accelerated projectile collides with liquid storage part and liquid jets were injected into supersonic conditions. Supersonic liquid jets show the multiple jets and generate shockwave at the forward region of jets. Supersonic liquid jets of speed and shockwave angle have different value at each case. Supersonic liquid jets with minimum velocities are injected with M=1.53 at the geometry condition of L/d=23.8.

  • PDF

Studies on the Landscape Greenery Specificity of Indigenous Plants (자생초본식물의 녹화소재로서의 특성에 관한 연구)

  • Bang, Kwang-Ja;Lee, Jong-Suk;Lee, Taek-Ju;Kang, Hyan-Kyoung;Sul, Jong-Ho
    • Journal of the Korean Society of Environmental Restoration Technology
    • /
    • v.1 no.1
    • /
    • pp.45-53
    • /
    • 1998
  • This study was conducted to investigate the ornamental, ecological, and using characteristic of Korean indigenous perennials of 100 species through observation in native region and in farm. The results were as follows : All of the species were divided into seven groups according to landscape use. Among Korean native perennials, Dicentra spectabilis, Dianthus superious var. longicalycinus, Aster koraiensis, Caryopteris incana, Ixeris stolonifera, Lilium, Chrysanthemum, Sedum, Potentilla, Hosta, Hemerocallis, and Liliope have high and long ornamental values regardless of flower. And they can be planted in any place of Korea.

  • PDF

Improvement of Head Related Transfer Function to Create Realistic 3D Sound (현실감있는 입체음향 생성을 위한 머리전달함수의 개선)

  • Koo, Kyo-Sik;Cha, Hyung-Tai
    • Journal of the Korean Institute of Intelligent Systems
    • /
    • v.18 no.3
    • /
    • pp.381-386
    • /
    • 2008
  • Virtual 3D audio methods that create 3D sound effects are researched highly for multimedia devices using 2 speakers or headphone. The most typical method to create 3D effects is a technology through use of head related transfer function (HRTF) which contains the information that sound arrives from a sound source to the ears of the listener. But it can decline some 3D effects by cone of confusion between front and back directions due to the non-individual HRTF depending on each listener. In this paper, we propose a new method to use psychoacoustic theory that creates realistic 3D audio. In order to improve 3D sound, we calculate the excitation energy of each symmetric HRTF and extract the ratio of energy of each bark range. Informal listening tests show that the proposed method improves the front-bach sound localization characteristics much better than the conventional methods.

Techniques of Oriental and Western Flower Arrangement through Historical Study (동서양 꽃꽂이의 역사적 고찰을 통해서 본 기법)

  • Lee, Jeong-Hwa
    • Journal of agriculture & life science
    • /
    • v.43 no.6
    • /
    • pp.53-57
    • /
    • 2009
  • The Oriental flower arrangements have the beauty of a strict triangle in a symmetrical three-dimensional effect as the form of flower tribute to gods in ancient times and used frogs to fix flowers to a basin easily. Flower arrangements of a conical shape made by repeatedly piled flowers in ancient Egypt shows the origin of the present vertical form of the Western flower arrangements. Flower arrangements in ancient Greece formed in a smooth S shape, while Roman flower arrangements were rich and gorgeous in a lowering and thin shape horizontally. Persians were showing triangular forms similar to the Oriental three-dimensional effect. The basic form of flower arrangements in the age of Renaissance was also created upon the ancient one, descending to Art Nouveau when flower arrangements were widely expressed from mass to space aesthetics led by America in the 20th century influenced by mild color, simplicity and realistic description of the Oriental art in the late 19th century. The Western flower arrangements are focused on formation, same as the Oriental ones, yet they disregard naturality and based on practicality.

Implementation of 3D Video using Time-Shortening Algorithm (시간단축 알고리즘을 통한 3D 동영상 구현)

  • Shin, Jin-Seob;Jeong, Chan-Woong
    • The Journal of the Institute of Internet, Broadcasting and Communication
    • /
    • v.20 no.6
    • /
    • pp.123-128
    • /
    • 2020
  • In this paper, we presents a new cone beam computerized tomography (CBCT) system for the reconstruction of 3 dimensional dynamic images. The system using cone beam has less the exposure of radioactivity than fan beam, relatively. In the system, the reconstruction 3-D image is reconstructed with the radiation angle of X-ray in the image processing unit and transmitted to the monitor. And in the image processing unit, the Three Pass Shear Matrices, a kind of Rotation-based method, is applied to reconstruct 3D image because it has less transcendental functions than the one-pass shear matrix to decrease a time of calculations for the reconstruction 3-D image in the processor. The new system is able to get 3~5 3-D images a second, reconstruct the 3-D dynamic images in real time. And we showed the Rotation-based method was good rather than existing reconstruction technique for 3D images, also found weakness and a solution for it.

Prosthetic Treatment Strategies for Improving Denture Retention in Pediatric Patients with Hypohidrotic Ectodermal Dysplasia: a Report of Two Cases (저한성 외배엽 이형성증을 가진 소아 환자에서 의치 유지력 향상을 위한 보철 치료 전략: 두 가지 증례 보고)

  • Hongju Jeon;Seonmi Kim;Namki Choi
    • Journal of the korean academy of Pediatric Dentistry
    • /
    • v.50 no.4
    • /
    • pp.483-494
    • /
    • 2023
  • This report presents two cases concerning strategies for improving denture retention in pediatric patients with oligodontia caused by hypohidrotic ectodermal dysplasia (HED). Both patients presented with multiple missing teeth, conical canines, alveolar bone atrophy, and a skeletal Class III tendency. In the first case, a modified form of conical-crown-retained denture was used to cover the canines. This approach was carried out without tooth extraction or coping. In the second case of severe alveolar bone resorption and a distally tilted lower left canine, the tooth was restored with a hybrid ceramic crown. It was subsequently converted into a clasp-retained removable partial denture, utilizing a suction mechanism. Both patients are currently receiving regular check-ups for the maintenance of their prosthetic appliances and the evaluation of their growth patterns. This study presents innovative prosthetic treatment methods for pediatric patients with HED who have inadequate denture retention.