• Title/Summary/Keyword: swirling

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Efficient Micro-Ozone-Bubble Generation by Improving Ozone Dissolution Tank Structure (오존용해탱크 구조 개선을 통한 효율적인 마이크로오존버블 생성)

  • Park, Yong-hwa;Lee, Gwang-hi;Jang, Am
    • Journal of Korean Society of Environmental Engineers
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    • v.39 no.10
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    • pp.549-555
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    • 2017
  • The purpose of this study is to investigate how ozone-dissolution-tank structure affects micro-ozone-bubble distribution, energy consumption and water treatment efficiency. The partition walls inside the ozone-dissolution-tank generate pressure changes, shear forces, and swirling flows, which change the size of the bubble diameter. The size of the bubble diameter differs by 10.5% depending on the partition walls. Changes in ozone-bubble diameter are related to energy consumption. As the ozone-bubble becomes smaller, the bubble generation energy increases, but the ozone production energy decreases as the dissolution efficiency increases. Therefore, an ozone-dissolution-tank should be determined by means of an optimal condition producing a micro-ozone-bubble with a minimum sum of bubble generation energy and ozone production energy. The energy consumed to inject the same amount of ozone into the effluent differs by 2.5% depending on the partition walls. However, considering the water treatment efficiency, the conditions for selecting the ozone-dissolution-tank are variable. This is because the free radicals that increase as the ozone-bubble gets smaller are very efficient for water treatment. Even at the same ozone injection concentration, the water treatment efficiency differs by 10.4% according to the partition walls. Therefore, we have studied ozone-dissolution-tank structure which produces reasonable ozone-bubble considering water treatment efficiency and energy efficiency.

Molecular and Morphologic Identification of Spirometra ranarum Found in the Stool of African Lion, Panthera leo in the Serengeti Plain of Tanzania

  • Eom, Keeseon S.;Park, Hansol;Lee, Dongmin;Choe, Seongjun;Kang, Yeseul;Bia, Mohammed Mebarek;Lee, Sang-Hwa;Keyyu, Julius;Fyumagwa, Robert;Jeon, Hyeong-Kyu
    • Parasites, Hosts and Diseases
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    • v.56 no.4
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    • pp.379-383
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    • 2018
  • The present study was performed with morphological and molecular analysis (cox1 and nad1 mitochondrial genes) to identify the proglottids of spirometrid tapeworm found in the stool of an African lion, Panthera leo, in the Serengeti plain of Tanzania. A strand of tapeworm strobila, about 75 cm in length, was obtained in the stool of a male African lion in the Serengeti National Park ($34^{\circ}$ 50' E, $02^{\circ}$ 30' S), Tanzania, in February 2012. The morphological features of the adult worm examined exhibited 3 uterine coils with a bow tie appearance and adopted a diagonal direction in the second turn. The posterior uterine coils are larger than terminal uterine ball and the feature of uteri are swirling rather than spirally coiling. The sequence difference between the Spirometra species (Tanzania origin) and S. erinaceieuropaei (GenBank no. KJ599680) was 9.4% while those of S. decipiens (GenBank no. KJ599679) differed by 2.1% in the cox1 and nad1 genes. Phylogenetic tree topologies generated using the 2 analytic methods were identical and presented high level of confidence values for the 3 major branches of the 3 Spirometra species in the cox1 gene. The morphological and molecular findings obtained in this study were nearly coincided with those of S. ranarum. Therefore, we can know for the first time that the African lion, Panthera leo, is to the definitive host of this tapeworm.

A Study of Cold Flow Characteristics of a Flue Gas Recirculation Burner using Coanda Nozzles (코안다 노즐을 이용한 배기가스 재순환 버너의 냉간 유동 특성에 관한 연구)

  • Ha, Ji Soo;Park, Chan Hyuk;Shim, Sung Hun;Jung, Sang Hyun
    • Journal of Energy Engineering
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    • v.25 no.4
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    • pp.152-158
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    • 2016
  • Nitrogen oxide is generated by the chemical reaction of oxygen and nitrogen in higher temperature environment of combustion facilities. The NOx reduction equipment is generally used in the power plant or incineration plant and it causes enormous cost for the construction and maintenance. The flue gas recirculation method is commonly adopted for the reduction of NOx formation in the combustion facilities. In the present study, the computational fluid dynamic analysis was accomplished to elucidated the cold flow characteristics in the flue gas recirculation burner with coanda nozzles in the flue gas recirculation pipe. The inlet and outlet of flue gas recirculation pipes are directed toward the tangential direction of circular burner not toward the center of burner. The swirling flow is formed in the burner and it causes the reverse flow in the burner. The ratio of flue gas recirculation flow rate with the air flow rate was about 2.5 for the case with the coanda nozzle gap, 0.5mm and it was 1.5 for the case with the gap, 1.0mm. With the same coanda nozzle gap, the flue gas recirculation flow rate ratio had a little increase when the air flow rate changes from 1.1 to 2.2 times of ideal air flow rate.

Analysis of Nonlinear Destructive Interaction between Wind and Wave Loads Acting on the Offshore Wind Energy Converter based on the Hydraulic Model Test (해상 풍력발전체에 작용하는 풍하중과 파랑하중간의 비선형 상쇄간섭 해석 -수리모형실험을 중심으로)

  • Cho, Yong Jun;Yang, Kee Sok
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.27 no.5
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    • pp.281-294
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    • 2015
  • In order to quantitatively estimate the nonlinear destructive interaction of wave load with wind load, which is very vital for the optimal design of offshore wind energy converter, we carried out a hydraulic model test and wind tunnel test. As a substructure of offshore wind energy converter, we would deploy the monopile, which is popular due to its easiness in construction. Based on the simulation using Monte Carlo simulation using Kaimal spectrum and cross spectrum, the instantaneous maximum wind velocity is adjusted to 10 m/s. And, considering the wave conditions of the Western Sea where a pilot wind farm is planned to be constructed, $H_s=0.1m$, 0.15 m, 0.2 m is carefully chosen. It turns out that the nonlinear destructive interaction between the wind and wave loads acting on the offshore wind energy converter is more clearly visible at rough seas rather than at mild seas, which strongly support our deduction that a Large eddy, a swirling vortex developed near the bumpy water surface in the opposite direction of the wind, is the driving mechanism underlying nonlinear destructive interaction between the wind and wave loads.

Genetic and Morphologic Identification of Spirometra ranarum in Myanmar

  • Jeon, Hyeong-Kyu;Park, Hansol;Lee, Dongmin;Choe, Seongjun;Kang, Yeseul;Bia, Mohammed Mebarek;Lee, Sang-Hwa;Sohn, Woon-Mok;Hong, Sung-Jong;Chai, Jong-Yil;Eom, Keeseon S.
    • Parasites, Hosts and Diseases
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    • v.56 no.3
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    • pp.275-280
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    • 2018
  • In the present study, we identified a Spirometra species of Myanmar origin (plerocercoid) by molecular analysis using mitochondrial cox1 and nad1 genes, as well as by morphological observations of an adult tapeworm. Spargana specimens were collected from a paddy-field in Taik Kyi Township Tarkwa Village, Yangon, Myanmar in December 2017. A total of 5 spargana were obtained from 20 frogs Hoplobatrachus rugulosus; syn: Rana rugulosa (Wiegmann, 1834) or R. tigrina (Steindachner, 1867). The plerocercoids were used for experimental infection of a dog. After 4 weeks of infection, an adult tapeworm was recovered from the intestine of the dog. Morphologically, the distinct features of Spirometra sp. (Myanmar origin) relative to S. erinaceieuropaei and S. decipiens include a uterine morphology comprising posterior uterine coils that larger than the terminal uterine ball and coiling of the uteri diagonally (swirling) rather than spirally. The cox1 sequences (1,566 bp) of the Myanmar-origin Spirometra species showed 97.9% similarity to a reference sequence of S. decipiens (GenBank no. KJ599679) and 90.5% similarity to a reference sequence of S. erinaceieuropaei (GenBank no. KJ599680). Phylogenetic tree topologies were identical and presented high confidence level of values for the 3 major branches of the 3 Spirometra species in cox1 and nad1 genes. These results indicated that Myanmar-origin Spirometra species coincided with those of S. ranarum and may be considered as a valid species.

Characteristics of Ammonia Removal from a Synthetic Wastewater in a Jet Loop Reactor with a Two-fluid Venturi-type Swirl Nozzle (이유체 벤츄리형 선회 노즐이 장착된 제트 루프 반응기에서 합성폐수 중의 암모니아 제거특성)

  • Noh, Da-ji;Yun, Chan-Su;Lim, Jun-Heok;Won, Yong-Sun;Lee, Tae-Yoon;Lee, Jea-Keun
    • Clean Technology
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    • v.23 no.2
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    • pp.205-212
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    • 2017
  • We investigated the performance of a jet loop reactor (JLR) with the two-fluid venturi-type swirl nozzle (TVSN) during experiment for ammonia removal by air stripping from a synthetic wastewater, and compared it with that of a JLR with the two-fluid venturi-type conventional nozzle (TVCN), with the variation of pH, liquid circulation rate ($Q_L$), and air flow rate ($Q_G$). Their performance levels were compared based on the ammonia removal efficiency and overall mass transfer coefficient ($K_La$). Investigated parameters in a JLR were pH (10-12), air flow rate ($Q_G=5-20L\;min^{-1}$), and liquid circulation rate ($Q_L=25-35L\;min^{-1}$). Throughout the experiment, the ammonia removal efficiency and $K_La$ in a JLR with TVSN was higher than in a JLR with TVCN. This may be due to the enhanced turbulent intensity by swirling flow formed in the JLR with TVSN compared to that with TVCN. Further, we obtained higher $K_La$ when pH, $Q_L$ and $Q_G$ were increased. In particular, $K_La$ was increased more efficiently by increasing $Q_G$ than by increasing pH and $Q_L$.

An Experimental Study on the Augmentation of Heat Transfer by Impinging Air Jets with Swirl (충돌선회분류(衝突旋回噴流) 열전달증진(熱傳達增進)에 관(關)한 실험적(實驗的) 연구(硏究))

  • Ohu, Su-Cheol;Park, Sung-Soo
    • Solar Energy
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    • v.13 no.1
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    • pp.22-30
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    • 1993
  • This Paper deals with the experimental study of the axisymmetric air jet impinging vertically on the flat heating surface with and without swirl. The purpose of this study is to investigate the characteristics of flow, augmentation of heat transfer rate, turbulent intensity, and the comparison of heat transfer rate, the optimal swirling condition about the swirl and nonswirl axisymmetric air jet. In order to augment the heat transfer on the flat heating surface without introducing any additional power, the technique used in the present work was placement of twisted tape inserted pipe in front of the nozzle exit in order to make a swirl. The effect of swirl degree is investigated in case of S=0., 0.056, 0.111, 0.222 and the velocity of the jet was 14, 20, 26, 32, 38, 44m/s. The distance between the nozle exit and the stagnation point on the impinging plate was the H/D=$1{\sim}14$. In order to analyze of the flow structure which increase heat transfer, the velocity and the turbulent intensity of the axisymmetric jet was measured by a hot wire anemometer according to the swirl number and H/D.

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Analysis of an internal flow with multi-perforated tube geometry in an integrated Urea-SCR muffler (다공튜브 형상변화에 따른 촉매 삽입형 Urea-SCR 머플러 내부유동 해석)

  • Moon, Namsoo;Lee, Sangkyoo;Lee, Jeekeun
    • Journal of Advanced Marine Engineering and Technology
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    • v.37 no.5
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    • pp.500-509
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    • 2013
  • This study reports a numerical analysis of the internal flow characteristics of the integrated urea-SCR muffler system with the various geometries of the multi-perforated tube which is set up between the muffler inlet and in front of SCR catalysts. The multi-perforated tube is generally used to disperse uniformly the urea-water solution spray and to make better use of the SCR catalyst, resulting in the increased $NO_x$ reduction and decreased ammonia slip. The effects of the multi-perforated tube orifice area ratios on the velocity distributions in front of the SCR catalyst, which is ultimately quantified as the uniformity index, were investigated for the optimal muffler system design. The steady flow model was applied by using a general-purpose commercial software package. The air at the room temperature was used as a working fluid, instead of the exhaust gas and urea-water solution spray mixture. From the analysis results, it was clarified that the multi-perforated tube geometry sensitively affected to the formation of the bulk swirling motion inside the plenum chamber set in front of the SCR catalyst and to the uniformity index of the velocity distribution produced at the inlet of the catalyst.

A Theory of Intermediality and its Application in Peter Greenaway's (상호매체성의 이론과 그 적용 - 피터 그리너웨이의 <프로스페로의 서재>를 중심으로)

  • PARK, Ki-Hyun
    • Cross-Cultural Studies
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    • v.19
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    • pp.39-77
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    • 2010
  • The cinema of Peter Greenaway has consistently engaged questions of the relationship between the arts and particularly the relations of image and writing to cinema. When different types of images are correlated and merged with each other on the borders of painting, photography, film, video and computer animation, the interrelationships of the distinct elements cause a shift in the notion of the whole image. This analysis proposes to articulate the complex relationship between the 'interartial' dimension and the 'intermedial' dimension in Peter Greenaway's film, (1991). If the interartiality is interested in the interaction between various arts, including the transition from one to another, the intermediality articulates the same type of relationship between two or more media. The interactional relationship is the same on both sides; on the contrary, the relationship between art and media does not show the same symmetry. All art is based on one or more media - the media is a condition existence of art - but no art can't be reduced to the status of media. This suggests that if the interartiality always involves the intermediality, this proposal may not be reversed. First, we analyse a self-conscious investigation into digital art and technology. Prosospero's Books can be read as a daring visual essay that self-consciously investigates the technical and philosophical functions of letters, books, images, animated paintings, digital arts, and the other magical illusions, which have been modern or will be post-modern media to represent the world. Greenaway uses both conventional film techniques and the resources of high-definition television to layer image upon image, superimposing a second or third frame within his frame. Greenaway uses the frame-within-frame as the cinematic equivalent of Shakespeare's paly-within-play : it offer him the possibility to analyse the work of art/artist/spectator relationship. Secondly, we analyse the relationship between the written word, oral word and the books. Like the written word, the oral word changes into a visual image: The linguistic richness and nuances of Shakeaspeare's characters turn into the powerful and authoritative, but monotone, voices of Gielgud-Prospero, who speaks the Shakespearean lines aloud, shaping the characters so powerfully through his worlds that they are conjured before us. Specially each book is placed over the frame of the play's action, only partially covering the image, so that it gives virtually every frame at least two space-time orientations. Thirdly, we try to show how Peter Greenaway uses pictorial references in order to illustrate the context of the Renaissance as well as pictorial techniques and language in order to question the nature of artistic representation. For exemple, The storm is visualised through reference to Botticelli's : the storm of papers swirling around the library is constructed to look like a facsimili copy of Michelangelo's Laurentiana Library in Florence. Greenaway's modern mannerism consists in imposing his own aesthetic vision and his questioning of art beyond the play's meta-theatricality: in other words, Shakespeare''s text has been adapted without being betrayed.

Qualitative Evaluation of Effectiveness of 'Family Hope Partner Project' for Pediatric Cancer Patients and their Families (소아암 환아와 가족을 위한 가족희망파트너사업의 효과에 대한 질적 평가)

  • Kim, Sunhee
    • Korean Journal of Family Social Work
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    • no.55
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    • pp.59-90
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    • 2017
  • The purpose of this study is to identify the overall effect of Family Hope Partner Project conducted by the Korean Association for Children with Leukemia and Cancer (KACLC) for pediatric cancer patients and their families and provide empirical basic data for the support of them. For this purpose, this study applied a qualitative research methodology as follows; 6 parents and 5 children who used the service for more than one year through the Family Hope Partner Project participated in the interviews. The interviews were conducted from June to July 2016, and the collected data were analyzed through the processes of qualitative analysis. The results of this study are as follows. Pediatric cancer patients and their families who were previously confronted with problems such as a 'barrier of severe pain' and 'swirling anxiety and exhaustion' experienced multi-dimensional effects, thanks to the intervention of 'a genuine master serving as a stepping stone toward their recovery and growth', who were linked to the pediatric cancer patients through Family Hope Partner Project. In other words, they experienced positive effects such as 'support for overall rehabilitation of pediatric patients', 'improvement of family relations', 'relief of needs for social relations', and 'liberation from pressure'. The results of this study were meaningful, in that it substantially corroborated the multidimensional effects of the Family Hope Partner Project, and presented the development direction of the Family Hope Partner Project, which was the first of its kind at home and abroad initiated by the Korean Association for Children with Leukemia and Cancer (KACLC) for pediatric cancer patients and their families.