• Title/Summary/Keyword: Wings

Search Result 530, Processing Time 0.025 seconds

Leaf and petiole anatomy of Thymelaeaceae Adans. in Korea and its taxonomic consideration (한국산 팥꽃나무과 잎과 엽병의 해부 및 분류학적인 검토)

  • Jung, Eun-Hee;Hong, Suk-Pyo
    • Korean Journal of Plant Taxonomy
    • /
    • v.35 no.2
    • /
    • pp.115-127
    • /
    • 2005
  • Two anatomical features of leaves, transverse section of midribs and petioles, were examined for nine species of five genera of Thymelaeaceae, Daphne L. -4 spp., Diarthron Turcz. -1 sp., Edgeworthia Meisn. -1 sp., Stellera L. -1 sp., Wikstroemia Endl. -2 sp., using light microscopy and scanning electron microscopy. In terms of shape of upper side, three types were observed, i.e., flattened, depressed, and raised. Outline of petioles is mostly semi-circular or circular in transverse section, with two distinct wings/weakly developed wings or without wings. Other characters besides anatomical features of leaves such as vascular bundle tissues, crystal, tannin are also described in details. Finally, we briefly discussed the systematic significance of the anatomical features of leaves for identification of Korean Thymelaeaceae.

Wind Tunnel Test Study on the Wings of WIG Ship (WIG선의 날개에 대한 풍동실험 고찰)

  • Kim, S.K.;Suh, S.B.;Lee, D.H.;Kim, K.E.
    • Journal of the Society of Naval Architects of Korea
    • /
    • v.34 no.1
    • /
    • pp.60-67
    • /
    • 1997
  • This paper presents the results of 3rd wind tunnel test for the wings of WIG R/C test models, 'Hanjin-1' & 'Hanjin-2'. We made 'Hanjin-1' in last May 1995 and had a success in test flight. And in order to grasp the aerodynamic characteristics of wings in ground effect, the measurements of lift and drag were carried out for the various kinds of wing. It was shown that lift and lift-drag ratio increase with decrease of the clearance, but the feature was considerably depended on the shape of wing section. In this case we select the three kind of wing. section, and then compare their characteristics especially for a stability in longitudinal motion. They are NACA6409 for 'Hanjin-1' and the two kinds of DHMTU for ekranoplans of Russia. Experimental results show that the pitching moments of DHMTU wing sections are smaller than NACA6409.

  • PDF

The Strain Corrections for Accuracy Improvement to Predict Large Deformation of Wings (날개 대변형 예측의 정확성 향상을 위한 변형률 보정)

  • Lee, Hansol;Kim, In-Gul;Park, Sunghyun;Kim, Min-Sung
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.44 no.1
    • /
    • pp.1-11
    • /
    • 2016
  • The information about the deformations of high-aspect-ratio wings is needed for the real-time monitoring of structural responses. Wing deformation in flight can be predicted by using relationship between the curvatures and the strains on the wing skin. It is also necessary to consider geometric nonlinearity when the large deformation of wing is occurred. The strain distribution on fixed-end is complex in the chordwise direction because of the geometric shape of fixed-wings on fuselages. Hence, the wing displacement can be diversely predicted by the location of the strain sensing lines in the chordwise direction. We conducted a study about prediction method of displacements regardless of the chordwise strain sensing locations. To correct spanwise strains, the ratio of spanwise strain to chordwise strain, Poisson's ratio, and the ratio of the plate strain to the beam strain were used. The predicted displacements using the strain correction were consistent with those calculated by the FEA and verified through the bending testing.

Comparison of fishing gears and catches by areas in the Gape net with wings in Jeonnam, Korea (전남지역 낭장망의 어구 및 어획물 비교)

  • Cho, Sam-Kwang;Song, Dae-Ho;Yoo, Joon-Taek;Choi, Mun-Seong;Cha, Bong-Jin
    • Journal of the Korean Society of Fisheries and Ocean Technology
    • /
    • v.50 no.3
    • /
    • pp.301-309
    • /
    • 2014
  • This study was carried out to compare the regional fishing gears and catches of the gape net with wings used in Jeonnam, Korea. The total length of the gear used in Yeosu, Wando and Jindo was 107.0m, 64.0m, 52.8m, and the size of codend was 4.3mm. 7.8mm. 9.8mm, respectively. The total number of bycatch species from anchovy (Engraulis japonicus) catches in Yeosu, Wando, and Jindo during the survey period were 21, 13, and 13 species. A total of individuals of anchovy accounted for over 90% out of total catches in all survey areas. The proportion of anchovy individuals was constantly high up to October in Yeosu, but it showed a sharp reduction to 18% in October in Wando with the increase of the individuals of Kammal thryssa (Thryssa kammalensis) and Big eyed herring (Sardinella zunasi). In Jindo, individuals of anchovy occupied over 99.8% out of total catches up to August. Since August, the number of individuals of Big eyed herring (Sardinella zunasi), Kammal thryssa (Thryssa kammalensis), and Slimy (Leiognathus nuchalis) has increased while the number of anchovy individuals were decreased.

A Convergent Investigation on the Air Flow Analysis of a Light Aircraft Propeller (경비행기 프로펠러의 공기 유동해석에 관한 융합 연구)

  • Choi, Kye-Kwang;Cho, Jae-Ung
    • Journal of the Korea Convergence Society
    • /
    • v.11 no.12
    • /
    • pp.131-135
    • /
    • 2020
  • In this study, the models with three, five and ten wings of the propeller which made a light aircraft fly were performed by air flow analyses. As for the flow model A with the shape with five wings, Model A can be seen to be the most ideal flow of air. The flow of air through the number of wings, which is not too many or too few, shows the most smooth flowing form. The smaller the number of propeller blades, the smaller the flow of air. Model A is applied under pressure of up to 0.5631 MPa at the front of air flow. Also, models B and C are applied under pressures of 0.5758 MPa and 0.5589 MPa, respectively. Comparing the pressure contours for each model of flux, model B can be shown to have the highest pressure distribution. The result of this study can be used to investigate the air flow without actual testing. It also seems to be helpful in the aesthetic convergent design of light aircraft propeller.

Studies on the Trial Manufacture of Telesounder and its Application (2) - Remote Observations of Fishes Entering in the Gape Nets With Wings - (원격어군탐지기의 시작 및 그 응용에 관한 연구 -II -낭장망 입망어군의 원격관측-)

  • 이원우
    • Journal of the Korean Society of Fisheries and Ocean Technology
    • /
    • v.31 no.1
    • /
    • pp.54-62
    • /
    • 1995
  • In order to telemeter the behavior and distribution of fishes. the telesounder was manufactured and it was examined to verify its performance and effects in the gape nets with wings located around Gokunsan islands. Yellow Sea. on August 8. 18~19 and September 8~9, 1994. The behavior of fish entering the net was observed with the buoy station at sea which was installed at the entrance of the gape nets with wing and its echosignal was transmitted remotely to the base station on ship at distance of about 1 km away from the buoy station at sea. The fishes catched by the gape nets with wings were 12 species and Anchovy(Engraulis japonica), Beka squid(Loligo beka), Herring(Harengula zunasi) was 95% of total catches. The images of color display monitor at the base station on ship were very well coincident with the records of fish finder from the buoy station located at sea. When the current velocity was less than 0.6 kt and slight fluctuation, the fishes entered into the gape net were much more in comparision with over 1.0kt and heavy fluctuation, and then the average swimming depth was about 4 m. The catches per one hauling was about 10~30 kg and when the current velocity was too weak and the current direction did not coincident with the direction of net or the current velocity was too strong, the catches was a few. It is concluded that telesounder system is very useful for investigating the distribution and the swimming behavior of fishes entering in the gape nets with wings.

  • PDF

Free surface effects on 2-D airfoils and 3-D wings moving over water

  • Bal, Sakir
    • Ocean Systems Engineering
    • /
    • v.6 no.3
    • /
    • pp.245-264
    • /
    • 2016
  • The iterative boundary element method (IBEM) developed originally before for cavitating two-dimensional (2-D) and three-dimensional (3-D) hydrofoils moving under free surface is modified and applied to the case of 2-D (two-dimensional) airfoils and 3-D (three-dimensional) wings over water. The calculation of the steady-state flow characteristics of an inviscid, incompressible fluid past 2-D airfoils and 3-D wings above free water surface is of practical importance for air-assisted marine vehicles such as some racing boats including catamarans with hydrofoils and WIG (Wing-In-Ground) effect crafts. In the present paper, the effects of free surface both on 2-D airfoils and 3-D wings moving steadily over free water surface are investigated in detail. The iterative numerical method (IBEM) based on the Green's theorem allows separating the airfoil or wing problems and the free surface problem. Both the 2-D airfoil surface (or 3-D wing surface) and the free surface are modeled with constant strength dipole and constant strength source panels. While the kinematic boundary condition is applied on the airfoil surface or on the wing surface, the linearized kinematic-dynamic combined condition is applied on the free surface. The source strengths on the free surface are expressed in terms of perturbation potential by applying the linearized free surface conditions. No radiation condition is enforced for downstream boundary in 2-D airfoil and 3-D wing cases and transverse boundaries in only 3-D wing case. The method is first applied to 2-D NACA0004 airfoil with angle of attack of four degrees to validate the method. The effects of height of 2-D airfoil from free surface and Froude number on lift and drag coefficients are investigated. The method is also applied to NACA0015 airfoil for another validation with experiments in case of ground effect. The lift coefficient with different clearance values are compared with those of experiments. The numerical method is then applied to NACA0012 airfoil with the angle of attack of five degrees and the effects of Froude number and clearance on the lift and drag coefficients are discussed. The method is lastly applied to a rectangular 3-D wing and the effects of Froude number on wing performance have been investigated. The numerical results for wing moving under free surface have also been compared with those of the same wing moving above free surface. It has been found that the free surface can affect the wing performance significantly.

Nutritional Analysis of Chicken Parts (닭고기의 부위별 영양 성분 분석)

  • Koh, Ha-Young;Yu, Ick-Jong
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.44 no.7
    • /
    • pp.1028-1034
    • /
    • 2015
  • General composition and cholesterol contents of chicken 4 parts (breasts, thighs, legs without skin, and wings with skin) were analyzed. Fatty acids, amino acids, and mineral contents of breasts and thighs were also analyzed and compared with sirloin parts of beef and pork. Lipid contents of chicken parts (1.2% in breasts, 2.8% in thighs, and 14.9% in wings) were lower than those of beef and pork. Protein contents of chicken parts (22.9% in breasts, 19.7% in thighs, and 17.6% in wings) were higher than those of beef and pork. Cholesterol contents of chicken parts (99.0 mg% in wings, 80.8 mg% in thighs, and 56.7 mg% in breasts) were higher than those of beef and pork. However, saturated fatty acid contents of chicken (31.6~32.9%) was lower than those of beef (40.8%) and pork (42.7%). In the meanwhile, unsaturated fatty acid contents of chicken (67.1~68.4%) was higher than those of beef (59.2%) and pork (57.3%). Essential fatty acid contents of chicken (16.6~16.9%) were 1.6 times as high as that of pork (10.4%) and 5 times as high as that of beef (3.9%). Major amino acids composition were glutamic acid, aspartic acid, lysine, and leucine. Ten essential amino acid contents were 11,860 mg% in breasts and 10,454 mg% in thighs, and the ratio of essential amino acids (41.7~44.1%) was similar to those of pork and beef. Mineral contents of chicken were similar to those of pork and beef despites of slight different mineral contents in thighs and breasts.

A Study on the functional pattern design for brassiere-focusing on large-breasted women- (기능성 브래지어 패턴디자인 연구 -돌출.하수 유방유형을 중심으로-)

  • Park, Eun-Mi;Im, Soon
    • Journal of the Korean Society of Clothing and Textiles
    • /
    • v.27 no.3_4
    • /
    • pp.407-417
    • /
    • 2003
  • The purpose of this study is to develop designs and patterns of a functional brassiere. For this purpose, women who have protruding and drooping breasts with 75B for their brassiere size were sampled. The fitting test for the fitness and function of test brassiere and control brassiere were carried out twice and compared the results from the both in terms of front, rear and side looks. The results of this study can be summarized as follows; 1. The results from measuring the level of sag and spread, and volume and protrusion of breasts shows that there are some distinctive differences in the measurements before and after wearing the test brassiere and the test brassiere is proved to be very effective in correcting breasts' shapes. 2. Front look: Since the two front cutting lines of the test brassiere served to have the curved main part pressing against the breasts, it could support breasts to more than satisfactory level. In addition, upperline panel and side panels of the test brassiere were found to have the upperline of the upper cup pressed against the breasts and at the same time it pressed and gathered the flab around upper part of the breasts and armpits that helped to rearrange the shape of the breasts. It is also proved that the two-pieced test brassier was found to be more functional in supporting the lower cup of the breasts. 3. Rear look: The test brassier was made up of two wide U-shaped wings with 2.5cm tape on its lower sides. Each wing has 4 lines and 3 hems (5.5cm). For this reason, the test brassiere was tighter and better fitted on its back. 4. Side look and entire look: The wings of the test brassiere might look wider than that of the control brassier which has conventional straight-shaped wings, but it was analyzed that the test brassiere held the upper and lower sides of the wings more effectively to be more pressed against the breast. Therefore, the test brassiere scored higher in terms of adjusting to body movements, while the control brassiere looked better in overall terms. 5. The functional brassier fur protruding and drooping breasts developed from the experiments of this study is a full side stretch brassiere which covers the entire breasts satisfactorily. The pattern drafting methods are suggested in to .