• Title/Summary/Keyword: Flat Part

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Dome Shape Design and Performance Evaluation of Composite Pressure Vessel (복합재 압력용기의 돔 형상 설계 및 성능 평가)

  • Hwang, Tae-Kyung;Park, Jae-Beom;Kim, Hyoung-Geun;Doh, Young-Dae;Moon, Soon-Il
    • Composites Research
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    • v.20 no.4
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    • pp.31-41
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    • 2007
  • Dome shape design methods of Filament Winding (FW) composite pressure vessel, which can suggest various dome contour according to the external loading conditions, were investigated analytically and numerically. The performance indices(PV/W) of the pressure vessels with same cylinder radius and boss opening but different dome shape were evaluated by finite element analysis under the internal pressure loading condition. The analysis results showed that as the dome shape becomes flat, the performance index decreases significantly due to the reduced burst pressure. Especially, for the case of the high value of the parameter ro, the ratio between the radii of the cylinder part and the boss opening, the flat dome is disadvantageous in the aspect of the weight reduction, and additional reinforcing dome design technique should be required to increase the burst pressure. For example, above ro=0.54 condition, the dome shape change according to the loading condition could cause the low burst pressure and increase of composite weight in dome region and is not recommendable except for the special case that maximum inner volume or sufficient space between skirt and dome is the primary design objective. However, at ro=0.35, the dome shape change brings not so significant differences in the performance of FW vessel.

Comparison of Hsp90 and CYP1A Expression Patterns by Water Temperature Stress in Atlantic Salmon (Salmo salar) (대서양 연어(Salmo salar)의 수온 스트레스에 의한 Hsp90 및 CYP1A 발현 양상 비교)

  • Kang, Han Seung;Song, Jae-Hee;Kang, Hee Woong
    • Journal of Marine Life Science
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    • v.3 no.2
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    • pp.51-58
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    • 2018
  • Variations in water temperature are known to affect almost every part of fish physiology. The rise in water temperature due to climate change can physically damage fish. This study was conducted to evaluate the health status of the Atlantic salmon (Salmo salar) at high water temperature (20℃) than the optimum water temperature (15℃). Liver tissue exerts important metabolic functions in thermal adaptation. Therefore, liver tissue was used in this study. The evaluation method is to develop the biomarker gene using NGS RNAseq analysis and to examine the expression pattern using RT-qPCR analysis. The NGS RNAseq analysis revealed 1,366 differentially expressed genes, among which 880 genes were increase expressed and 486 genes were decrease expressed. The biomarker genes are such as heat shock protein 90 alpha (Hsp90α), heat shock protein 90 beta (Hsp90β) and cytochrome P450 1A (CYP1A). The selected genes are sensitive to changes in water temperature through NGS RNAseq analysis. Expression patterns of these genes through RT-qPCR were similar to those of NGS RNAseq analysis. The results of this study can be applied to other fish species and it is considered to be useful industrially.

Metamorphic Evolution of the central Ogcheon Metamorphic Belt in the Cheongju-Miwon area, Korea (청주-미원지역 중부 옥천변성대의 변성진화과정)

  • 오창환;권용완;김성원
    • The Journal of the Petrological Society of Korea
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    • v.8 no.2
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    • pp.106-124
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    • 1999
  • In the Cheongju-Minwon area which occupies the middle part of the Ogcheon Metamorphic Belt, three metamorphic events(M1, M2, M3) had occurred. Intermediate P/T type M2 regional metamorphism formed prevailing mineral assemblages in the study area. Low PIT type M3 contact metamorphism occurred due to the intrusion of granites after M2 metamorphism. M1 metamorphism is recognized by inclusions within garnet. During M2 metamorphism, the metamorphic grade increased from the biotite zone in the southeastern part to the garnet zone in the northwestern part of the study area. This result is similar to the metamorphic evolution of the southwestern part of the Ogcheon Metamorphic Belt. Garnets in the garnet zone are classified into two types; Type A garnet has inclusions whose trail is connected to the foliation in the matrix and Type B garnet has inclusion rich core and inclusion poor rim. Type A garnet formed in the mica rich part with crenulation cleavage whereas Type B garnet formed in the quartz rich part with weak crenulation cleavage. In some outcrops, two types garnets are found together. Compared to the rim of Type A garnet, the rim of Type B garnet is lower in grossular and spessartine contents but higher in almandine and pyrope contents. In some Type B garnets, the inclusion poor part is rimmed by muddy colored or protuberant new overgrowth. In the inclusion poor part and new overgrowth, a rapid increase in grossular and decrease in spessartine is observed. However, the compositional patterns of Type A and B are similar; Ca increases and Mn decreases from core to rim. Two types garnets formed mainly due to the difference of bulk chemistry instead of metamorphic and deformational differences. The metamorphic P-T conditions estimated from Type A garnets are 595-690 OC15.7-8.8 kb, which indicates M2 metamorphism is intermediate P/T type metamorphism. On the other hand, a wide range of P-T conditions is calculated from Type B garnets. The P-T conditions from most Type B garnet rims are 617-690 OC16.2-8.9 kb which also indicates an intermediate P/T type metamorphism. However, at the rim part with flat end or weak overgrowth, grossular content is low and 573-624OC14.7-5.8 kb are estimated. The P-T conditions calculated from plagioclase and biotite inclusions in garnet are 460-500 0C/1.9-3.0 kb. The P-T conditions from rim part with weak overgrowth and inclusions within garnet, indicate that low P/T type M1 regional metamorphism might have occurred before intermediate P/T type M2 regional metamorphism. The P-T conditions estimated from samples which had undergone low PIT type M3 metamorphism strongly, are 547-610 0C/2.1-5.0 kb.

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A Comparison of Lens Centrations on Cornea with RGP Lens Fitting by the Measured Values using Keratometer and Corneal Topography (각막곡률계와 각막 지형도 검사에서의 측정값을 이용한 RGP 렌즈 피팅시 각막에서의 중심안정위치 비교)

  • Kim, So Ra;Park, Sang-Il;Lee, Se Eun;Park, Mijung
    • Journal of Korean Ophthalmic Optics Society
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    • v.16 no.1
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    • pp.41-50
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    • 2011
  • Purpose: The present study was conducted to compare the centration of RGP lens on cornea when lens was fitted based on keratometric astigmatisms measured by keratometer and the lens centration when fitted by corneal topography. Methods: Thirty eight eyes of 19 male and female in their twenties were applied RGP lens with 9.9 mm of diameter by the keratometric astigmatisms classified by the measurement with a keratometer. Then, lens centrations were estimated using high speed camera and compared with the lens centration when fitted by total keratometric astigmatism using corneal topography. The relationship of the steepest location of cornea and lens centration was further compared. Results: With the rule astigmatism, lens centration was not changed even with the difference in central and total keratometric astigmatisms. When the relationship of the steepest part of cornea measured by corneal topography and lens centration was analyzed, the lens centration in vertical direction was exactly correlated with the steepest part of cornea in 52.3% of subjects. In the case of non-correlation, the steepest part of cornea was mostly upper part of cornea, however, lens centration was located on lower part of cornea. The lens centration in horizontal direction was exactly correlated with the steepest region of cornea in 65.6% of subjects. In non-correlated case, the difference in cornea curvatures between the steepest and the flattest parts was smaller than 0.05 mm in 76.9% of subjects. Conclusions: From these results, we conclude that corneal topographic patterns may more contribute the centration of RGP lens on cornea than the difference in central and total keratometric astigmatisms.

A Morphologic Study of Head and Face of Man in the Age 30 to 40 according to Sasang Constitution (30-40대(代) 남성(男性)의 사상체질별(四象體質別) 안면특징(顔面特徵)에 관(關)한 연구(硏究))

  • Jung, Kwang-Hee;Koh, Byung-Hee;Song, Il-Byung
    • Korean Journal of Oriental Medicine
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    • v.6 no.1
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    • pp.29-46
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    • 2000
  • The clinical application of constitutional Diagnosis is the most important part of Sasang constitutional medicine. It has been studied in various way. The study of morphologic characteristics on the head and face has been identified but didn't considered the Variations of age and sex. For the statistic analysis of the correlation between the sasang constitution and the shape of the face, the head-facial part of 182 cases(the group of throughout the age) and 69 cases(the group of age 30 to 40) were measured by Martin's measurement and analysis of a) the measurement value of height and the component ratio from the Gnathion to each part of face by constitution. b) the measurement value of depth and the component ratio from T-projected to each part of the face by constitution. c) the measurement value of breadth and component ratio between each parts of the facial breadth by constitution. d) the characteristics on each part of face by constitution. e) the result of discriminant analysis about the constitution Authors obtained the results from the study as follows: 1. Taeum-In group is characterized by the value of variables had a tendency to maximum value in throughout the age, the charateristics that the total group show is the shape of face is wide shape in horizontally and flat, the nasal breadth is wider than other constitutions, the lips is narrower than Soyang-In in horizontally and thick shape in vertically, and the biogonial breadth is more developed than other constitutions, so lower face is developed. The charateristics that only the age of 30 40 group show is that the lips is thicker than Soeum-IN. The projection of inter-eyebrows is more projected than Soyang-IN. 2. Soeum-IN group is characterized by the value of variables had a tendency to minimum value in throughout the age. The characteristics that the total group show is the lips is thiner than other constitutions, the breadth of eyes is wider than other constitutions, the difference between sellion and nasal breadth is to be little. The charateristics that only the age of 30 40 group show is that the ratio of upper face in physiognomic face is lager than Soyang-IN. 3. The total age group of Soyang-In is characterized by the shape of face is long in vertically and narrow in horizontally, the total eyebrow breadth and lips and philtrun is wider than other constitutions. The charateristics that only the age of 30 40 group is characterized by the projection of sellion is more projected than Taeum-IN. 4. The values which showed significance in both age group V76, V52, V54, V55, V57, V59, V64, V65, V67, V88, V89, V148, V150, V151, V155, V160, V161, V28, V50, V99, V102, V167, V169, V173, V175, V177, V181 are 27 in all. 5. The values which was significant in the age 30 to 40 group V77, V78, V79, V109, V140, V142, V143, V166, V174 are 9 in all.

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Development of Chestnut Harvesters for Small Farms (소농을 위한 밤 수확기의 개발)

  • Kang, Whoa-Seug;Guyer, Daniel
    • Journal of Biosystems Engineering
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    • v.33 no.6
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    • pp.384-389
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    • 2008
  • Three prototype chestnut harvesters were constructed and evaluated their chestnut collection ability and field efficiency. Air-lock paddle system successfully picked up all loose material, and pick up efficiency was about 56 kg/h. Power required to operate this system was evaluated to be 8.7 kW with an air flow rate of $32.6\;m^3/min$. A radial blade type blower with 0.41 m impeller diameter was considered to be a minimum size for this system. For the auger system, air was sucked into the cylinder as the hinged flat cover began to be opened by the material pushed by the auger, and the empty burrs flew back to the container through the space between auger flights and collected in the bottom of the container. It was considered to add a device to prevent air from flowing back or to use the back flowing air for separation of burrs and nuts inside the container. The venturi system could not pick up chestnuts, as they only carried part way up to the suction hose. Consideration was given to an idea that the venturi could be used as a cleaning and separation mechanism for containers filled with both empty burrs and good nuts. A minimum vacuum of 129 mm wg was required to pick up chestnuts, and the corresponding inlet air velocity was 19.3 m/s. 104 mm of vacuum, which was about 81 % of that required for nuts, was enough to pick up burrs with nuts inside. Also, empty burrs with higher moisture content recorded the same pressure as for the burrs with nuts.

The effects of increased unilateral and bilateral calcaneal eversion on pelvic and trunk alignment in standing position

  • Yi, Jaehoon
    • Physical Therapy Rehabilitation Science
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    • v.5 no.2
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    • pp.84-88
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    • 2016
  • Objective: Generally, it is known that there is a correlation between excessive calcaneus eversion and a patient with low back pain and it also affects pelvic alignment. However, there are not enough studies that show calcaneal eversion having an effect on the alignment of the trunk. Design: Cross-sectional study. Methods: A 3-dimensional motion analysis system was used to assess the lower limbs, pelvic alignment, and trunk alignment with increased unilateral and bilateral calcaneal eversion in twenty-one subjects. All subjects were asked to maintain a static posture for seven seconds on a wedge three times per posture for measurement and analysis purposes. The wedge used in the process was a lateral wedge with a 10-degree tilt to the lateral direction. To unify all of the subjects' foot position, the front and inner side of the wedge were marked. The height of the tilted wedge's inner side and flat wedge were balanced equally in order to be able to maintain the lateral part of the foot to the same height when producing an increased calcaneal eversion. Results: Comparing the changes in trunk and pelvic alignment in accordance to calcaneal eversion for each posture, there was a significant different in the X and Y-axis for each posture, but not in the Z-axis (p<0.05). Thus, it can be confirmed that calcaneal eversion in the sagittal plane and frontal plane may have and effect on the pelvis and the trunk. Conclusions: Postures with increased bilateral and unilateral calcaneal eversion has an effect on pelvic alignment, but does not cause any changes in trunk alignment.

A Comparative Study of Ancient Palace Ponds of Korea, China and Japan - Focus on the Recent Excavated Palace Pond - (고대 한.중.일 원지의 비교연구 - 최근 발굴된 원지를 중심으로 -)

  • 박경자
    • Journal of the Korean Institute of Landscape Architecture
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    • v.30 no.4
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    • pp.1-8
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    • 2002
  • The place of South Weol Dynastys authorities exhumed in the region of KangChoWu, China lies adjacent to a stone ditch through which water streams crookedly, and a dark trough of stone pond in the north side. There is a sharply curved stone ditch and a crescent-shaped water entrance made by stones. The place was separated by using stone columns and stone walls. There is a beam of ditch, a crooked entrance, a flat bridge of slate, a stepping-stone, a sluice gate, and a crooked corridor. There are big and small artificial islands, and reinforcing stone drainage way in the palace pond recently exhumed at the building site for the pavilion of Hwang-Yong Temple in Kuhwang-Dong, Gyeongju city, Korea. There are four facilities assumed to be entrance and exits at four corners and an open space on which gravel was spread extensively. A narrow road and a middle road with indefinite curves at the south of Asukakyoseki exhumed by the first, second and third and two stone buckets which one is to fill with water and the other is to drain water off like fountain are there, and besides wave protecting dam and north pond and the part that water pass were excavated. Palace ponds that were extensively distributed at old residential cities are a general phenomenon of countries in eastern Asia. Anap pond of Silla and Gungnam pond of Baekje were in Kroea. We believe that Asutnkyoseki is on the extension. Although more investigations in the background of thought and the genealogical relation about the palace pond are required, it seems that an idea was surely received from China.

A Numerical Analysis on Transient Temperatures of Fuel and Oil in a Military Aircraft (항공기내 연료 및 오일온도 변화에 대한 수치해석적 연구)

  • Kim, Yeong-Jun;Kim, Chang-Nyeong;Kim, Cheol-In
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.26 no.8
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    • pp.1153-1163
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    • 2002
  • A transient analysis on temperatures of fuel and oil in hydraulic and lubrication systems in an aircraft was studied using the finite difference method. Numerical calculation was performed by an explicit method with modified Dufort-Frankel scheme. Among various missions, air superiority mission was considered as a mission model with 20% hot day ambient condition in subsonic region. The ambience of the aircraft was assumed as turbulent flow. Convective heat transfer coefficient were used in calculating heat transfer between the aircraft surface and the ambience. For an aircraft on the ground, an empirical equation represented as a function of free-stream air velocity was used. And the heat transfer coefficient for flat plate turbulent flow suggested by Eckert was employed for in-flight phases. The governing equations used in this analysis are the mass and energy conservation equations on fuel and oils. Here, analysis of fuel and oil temperature in the engine was not carried out. As a result of this analysis, the ground operation phase has shown the highest temperature and the largest rate of temperature increase among overall mission phases. Also, it is shown that fuel flow rate through fuel/oil heat exchanger plays an important role in temperature change of fuel and oil. This analysis could be an important part of studies to ensure thermal stability of the aircraft and can be applicable to thermal design of the aircraft fuel system.

Effects of Humidity and Velocity on Frost Distribution Characteristics of Humid Air Flow on Cold Surfaces (차가운 표면위에서의 습공기 유동의 습도 및 속도가 착상분포 특성에 미치는 영향)

  • Kwon Jeong-Tae;Rew Keun-Ho;Lim Hyo-Jae;Han Ji-Won;Kwon Young Chul
    • Journal of Energy Engineering
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    • v.14 no.4 s.44
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    • pp.213-218
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    • 2005
  • In order to understand the heat and mass transfer characteristics of humid airflow in frosting conditions, a flat plate of aluminum with cooling modules located in the central part of the plate was used. A microscope system (resolution of 0.05 mm) was used for the measurement of local thickness of frost at seven points along the plate in the flow direction. For the total mass of frost at each test operation, an electronic balance (resolution of 1 mg) was used. The local frost thickness distributions far various test conditions were presented along with the frost mass data measured at the given operating times. The effect of humidity and velocity of humid air on frosting were analyzed.