• Title/Summary/Keyword: microscopic characteristics

Search Result 672, Processing Time 0.024 seconds

A Study on Characteristics of Gas/Liquid Coaxial Sprays Under Varying Flow Conditions (분사조건에 따른 기체/액체 동축형 인젝터의 분무특성에 관한 연구)

  • Jeong, W.H.;Kim, D.;Im, J.H.;Yun, Y.
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.33 no.1
    • /
    • pp.54-61
    • /
    • 2005
  • Characteristics of sprays injected by gas/liquid coaxial atomizers operated at atmospheric pressure are studied using shadowgraph, mechanical patternator and PDPA. The gas-to- liquid momentum flux ratio(M) and the liquid Reynolds number(Re) are selected as key parameters in characteristics of gas/liquid coaxial sprays from the dimensional analysis. The properties of shear coaxial sprays are compared with those of swirl coaxial sprays through the macroscopic and microscopic analysis. Macroscopic similarities between shear and swirl coaxial sprays are revealed under flow conditions of high momentum flux ratio. Also, empirical correlations between the mean drop diameters(D32) and operating conditions of coaxial sprays are proposed in this paper.

Confirmation of Chestnut Powdery Mildew, Erysiphe castaneigena, in Korea with Morphological Characteristics and Molecular Analyses (형태적 특징 및 분자적 분석에 의한 밤나무 흰가루병균 Erysiphe castaneigena의 확인)

  • Cho, Sung-Eun;Lee, Sang-Hyun;Lee, Sun Keun;Shin, Hyeon-Dong
    • The Korean Journal of Mycology
    • /
    • v.45 no.2
    • /
    • pp.145-152
    • /
    • 2017
  • The powdery mildew on Castanea crenata in South Korea was first recorded as Microsphaera alni in 1958. On the basis of its morphological characteristics and host range, the mildew was determined as Microsphaera sinensis in 1988. According to the rules of The International Code of Botanical Nomenclature, M. sinensis was renamed Erysiphe castaneigena in 2006. Nevertheless, taxonomic re-consideration of the morphological and molecular characteristics for the Castanea powdery mildew in Korea has not been performed. In the present study, we studied 34 powdery mildew samples collected from C. crenata in the Korea University Herbarium. On the basis of microscopic examinations of the holomorph and phylogenetic analysis of the internal transcribed spacer regions, we confirmed the powdery mildew fungus as E. castaneigena. In addition, sequence comparison between E. castaneigena and E. alphitoides ex Castanea sp. suggested a close phylogenetic affinity.

The Rational Regulation of Illegal & Harmful Information in Cyberspace (모바일 라이브 스트리밍 서비스의 불법·유해방송 근절에 관한 연구)

  • Song, You-Jin;Kim, Seung-In
    • Journal of the Korea Convergence Society
    • /
    • v.8 no.9
    • /
    • pp.231-236
    • /
    • 2017
  • This study analyzes the characteristics of mobile live streaming service, the illegal and harmful information characteristics of mobile live streaming service for the purpose of eradicating illegal and harmful broadcasting, and shows illegal and harmful broadcast on the mobile live streaming service and eradication plan. First, we reviewed the mobile live streaming service, illegal and harmful broadcasts through literature review, and secondly surveyed illegal and harmful broadcasts of mobile live streaming services and their awareness and countermeasures. As a result, it is confirmed that the mobile live streaming service is illegal, harmful broadcasting exposure frequency is high, illegal, and harmful broadcasting exposure is caused by characteristics of real time broadcasting rather than user's. In order to eradicate the illegal and mobile information about the mobile live streaming service, it is necessary to fix the illegal service and harmful broadcasting reporting system, but the government has confirmed the requirements for regulatory measures. From a microscopic point of view, it will be necessary to investigate the illegal use of mobile live streaming services and the eradication of harmful information.

Tribology Characteristics of Hexagonal Shape Surface Textured Reduction Gear in Electric Agricultural Vehicle

  • Choi, Wonsik;Pratama, Pandu Sandi;Byun, Jaeyoung;Kwon, Soonhong;Kwon, Soongu;Park, Jongmin;Kim, Jongsoon;Chung, Songwon
    • Journal of the Korean Society of Industry Convergence
    • /
    • v.22 no.1
    • /
    • pp.47-54
    • /
    • 2019
  • An experimental study was conducted on the wear and friction responses in sliding tests of a micro-textured surface on laser pattern (LP) steel as reduction gear material in electric guided vehicle. In this research, the friction characteristics of laser pattern steel under different micro texture density conditions were investigated. The friction tests were carried out at sliding speeds of 0.06 m/s to 0.34 m/s and at normal loads of 2 to 10 N. Photolithography method was used to create the dimples for surface texturing purpose. Four different specimens having different dimple densities of 10%, 12.5%, 15%, and 20% were observed respectively. In this research, friction conditions as shown in Stribeck curve were investigated. Furthermore, the microscopic surface was observed using scanning electron microscope. It was found that the dimple density had a significant role on the friction characteristics of laser pattern steel conditioned as reduction gear material in an agricultural vehicle. The duty number showed that the friction condition was hydrodynamic regime. The best performance was obtained from 12.5% dimple density with lowest friction coefficient achieved at 0.018771 under the velocity of 0.34 m/s and 10N load.

Analysis of Correlation between Flexural Strength and Pore Characteristics on CFRP Rebar as Fabrication Method (탄소보강근의 제조 조건에 따른 휨강도와 기공 특성과의 상관성 분석)

  • Kim, Nam-Il;Kwon, Do-Young;Chu, Yong-Sik
    • Composites Research
    • /
    • v.35 no.5
    • /
    • pp.328-333
    • /
    • 2022
  • In this study, the fabrication conditions of CFRP rebar were controlled to derive the correlation between flexural strength and pore characteristics. The fabrication conditions of CFRP rebar were adjusted for presence or absence of rib, resin temperature, and curing furnace temperature. Flexural strength and pore characteristics of fabricated CFRP rebar were analyzed. The flexural strength of CFRP rebar was changed depending on the fabrication condition, such as the presence or absence of rib, the resin temperature, and the curing furnace temperature. It was confirmed that the flexural strength of CFRP rebar was significantly lowered when the rib was not wound. As a result of Nano X-ray CT analysis, the max. pore diameter was shown in CFRP rebar prepared at a resin temperature of 60℃. According to optical microscopic analysis, the maximum porosity was 6.89% in No. 1, and the minimum porosity was 2.88% in No. 7. The correlation coefficient between porosity used optical microscopy and flexural strength was -0.64, which was higher than the correlation coefficient between porosity or pore size used Nano X-ray CT and flexural strength.

Reproductive Characteristics of Pacific Anchovy Engraulis japonicus from the Southern Waters of Korea (남해안에 서식하는 멸치(Engraulis japonicus)의 산란 특성)

  • Moon, Seong Yong;Baeck, Gun Wook;Lee, Mi Hee;Kim, Heeyong;Jung, Kyung Mi
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.55 no.6
    • /
    • pp.927-937
    • /
    • 2022
  • The reproductive characteristics of Pacific anchovy, Engraulis japonicus were investigated using samples randomly collected from the southern waters of Korea between January and December 2021. We analyzed monthly changes in maturity stages, gonadosomatic index (GSI), egg diameter, fecundity, and fork length (FL) at sexual groups maturity of 50%, 75% and 97.5%, and sex ratio (female:male). GSI value showed two peaks in May and August; however, microscopic analysis of E. japonicus gonad tissue revealed that the spawning period was from March to October. The main spawning seasons for the entire populations were from April to June and August to September. The overall sex ratio was female-biased (1 females, 0.89 male). The fecundity (F) of female anchovies ranged from 429 eggs at an FL of 8.0 cm to 13,824 eggs at an FL of 14.9 cm and the relationship between FL and F was 0.0788FL4.422. The FL at 50% group maturity was 8.26 cm for female anchovies. Based on the results, we suggest that the reproductive cycle in Pacific anchovies may be related to pulses in water temperature and the sexual cycle of the fish.

Development of A Network loading model for Dynamic traffic Assignment (동적 통행배정모형을 위한 교통류 부하모형의 개발)

  • 임강원
    • Journal of Korean Society of Transportation
    • /
    • v.20 no.3
    • /
    • pp.149-158
    • /
    • 2002
  • For the purpose of preciously describing real time traffic pattern in urban road network, dynamic network loading(DNL) models able to simulate traffic behavior are required. A number of different methods are available, including macroscopic, microscopic dynamic network models, as well as analytical model. Equivalency minimization problem and Variation inequality problem are the analytical models, which include explicit mathematical travel cost function for describing traffic behaviors on the network. While microscopic simulation models move vehicles according to behavioral car-following and cell-transmission. However, DNL models embedding such travel time function have some limitations ; analytical model has lacking of describing traffic characteristics such as relations between flow and speed, between speed and density Microscopic simulation models are the most detailed and realistic, but they are difficult to calibrate and may not be the most practical tools for large-scale networks. To cope with such problems, this paper develops a new DNL model appropriate for dynamic traffic assignment(DTA), The model is combined with vertical queue model representing vehicles as vertical queues at the end of links. In order to compare and to assess the model, we use a contrived example network. From the numerical results, we found that the DNL model presented in the paper were able to describe traffic characteristics with reasonable amount of computing time. The model also showed good relationship between travel time and traffic flow and expressed the feature of backward turn at near capacity.

The post-epic characteristics in Jan Lauwers' theatre -, and - (얀 라우어스(Jan Lauwers) 공연의 탈서사적 특징들 -<이사벨라의 방(Isabella's Room)>, <랍스터 가게(The Lobster Shop)>, <사슴의 집(Deer House)>을 중심으로-)

  • Nam, Jisoo
    • Journal of Korean Theatre Studies Association
    • /
    • no.48
    • /
    • pp.447-484
    • /
    • 2012
  • This study aims to analyze the characteristics of post-epic theatre in the Belgian theatre director Jan Lauwers' trilogy titled in "Happy Face/Sad Face": (2004), (2006) and (2008). I regard that it played a very important junction for him to create his own theatrical style compared to earlier years. From this period, Lauwers has tried to create his original plays in order to concentrate the story of our era and has showed to combine a variety of media such as dance, installation, video, singing etc. In this context, I would like to study his own theatricality from the three perspectives of dramaturgy, directing and acting largely based on Hans-Thies Lehmann's theory of post-epic theatre, who pointed out the significance of Lauwer's theatrical leading role very early. First, from the dramaturgical point of view, we need to pay attention to the theme of translunary death; where the living and the dead coexist on the stage. In fact, death is the theme that Lauwers has been struggling to research for quite long time. In his trilogy, the dead never exits the stage. The dead, who is not a representative tragic character, even meddles the things among or with the living and provide comments to people. As a consequence, it happens to reduce a dramaturgical strong tension, leads depreciation of suspense and produces humanism in a way. This approach helps to create his unique comical theatrical atmosphere even though he deals with the contemporary tragic issues such as war, horror and death. Second, from the directing point of view, it is worth to take a look at the polyphonic strategy in terms to applying various media. Among all the things, the arts of dancing and singing in chorus are actively applied in Lauwer's trilogy. The dance is used in individual and microscopic way, on the other hand, singing shows collective and is a macroscopic quality. The dance is the representing media to show Lauwer's simultaneous microscopic mise-en-scene. While main plot takes place around the center-stage, actors perform a dance around the off-centered stage. Instead of exiting from the stage during the performance, the actors would continue dance -sometimes more like movements- around the off-centered stage. This not only describes the narrative, but also shows how each character is engaged to the main plot or incident, and how they look into it as a character. Its simultaneous microscopic mise-en-scene intends to function such as: showing a variety moments of lives, amplifying some moments or incidents, revealing character's emotion, creating illusionary theatrical atmosphere and so on. Meanwhile, singing simple lyrics and tunes are an example of the media to stimulate the audiences' catharsis. As the simple melody lingers in the audiences' mind, it ends up delivering a theatrical message or theme after the performance. This message would be transferred from the singing in chorus functions as a sort of leitmotive in order to make an impression to the audience. This not only richens their emotion but also creates an illusionary effect. Third, from the acting perspective, I'd like to point out the "detachment" aesthetic which Lehmann has pointed out. The actors never go deep into the drama by consistently doing recognize a theatrical illusion. The audience happens to pay attention to their presence through the actor's deliberate gesture, business, movement, rhythm, language, dance etc. The actors are against forming closed action by speaking in various languages or by revealing deliberately stage directions or acts, and by creating expressive mise-en-scene with multiple media. As a consequent, the stage can be transformed to not a metaphoric but a metonymic place. These actions are the ultimate intention for a direct effect to the audience. So to speak, Lauwers uses the anti-illusionary theatrical method: the scenes of fantastic death, interruption of singing and dance, speaking many kinds of languages, acting in detachment-status and so on. These strategies function to make cracks in spectators' desire who has a desire to construct a linear narrative. I'd like to say that it is the numerous potentiality to let the reality penetrate though and collide the reality with a fiction. By doing so, it induces for spectators to see the reality in the fiction. As Lehmann says, "when theatre presents itself as a sketch and not as a finished painting, the spectators are given the chance to feel their own presence, to reflect on it, and to contribute to the unfinished character themselves". In this sense the spectators can perform an objective criticism on our society and world in Lauwer's theatre because there are a number of gaps and cracks in his theatrical illusion where reality can penetrate. This is also the point that we can find out the artists' responsibility in this era of our being.

A Study about The Typical Patterns of Driver's Characteristics by The Q Analysis Method (with Traffic Law Violator and Traffic Accident Causer) (Q 분석 방법을 이용한 운전자 운전성향별 유형화에 관한 연구 (교통법규 위반자 및 교통사고 야기자를 중심으로))

  • Jang, Seok-Yong;Jung, Hun-Young;Lee, Won-Gyu;Ko, Sang-Seon
    • Journal of Korean Society of Transportation
    • /
    • v.26 no.1
    • /
    • pp.165-180
    • /
    • 2008
  • The purpose of this research is to propose an effective traffic safety countermeasure to reduce both violations of road traffic acts and accident rates related to the driver's characteristics by measuring them using Q analysis method, a microscopic statistics analysis method. As a result, violators of the road traffic act could be divided into five driving characteristics and causers of traffic accident could be classified into six driving characteristics. By understanding these characteristics, We could establish a proper traffic safety countermeasure for each driving characteristic. The accomplishments of this research are as follows: The first, We could classify the decisive driving characteristics, which cause road traffic acts and traffic accidents, into internal and external causes. The relationship between each driver's characteristic and the occurrence of the road traffic act and traffic accident could be recognized more clearly. We could find the dangerous driver samples who have Accidents proneness. The second, As a result of analyzing the characteristics of these factors, We could sort out and suggest countermeasure for reducing violation of road traffic acts and traffic accidents as a priority countermeasure and complementary countermeasure. Finally, transportation companies most closely related to automobile accidents can judge new personnels on the basis of their driving characteristics before hiring, and also apply this principle to the traffic safety education vigorously.

The Possible Involvement of the Cell Surface in Aliphatic Hydrocarbon Utilization by an Oil-Degrading Yeast, Yarrowia lipolytica 180

  • Kim, Tae-Hyun;Oh, Young-Sook;Kim, Sang-Jin
    • Journal of Microbiology and Biotechnology
    • /
    • v.10 no.3
    • /
    • pp.333-337
    • /
    • 2000
  • An oil-degrading yeast, Yarrowia lipolytica 180, exhibits interesting cell surface characteristics under the growth on hydrocarbons. An electron microscopic study revealed that the cells grown on crude oil showed protrusions on the cell surface, and thicker periplasmic space and cell wall than the cell surface, and thicker periplasmic space and cell wall than the cells grown on glucose. Y. lipolytica cells lost its cell hydrophobicity after pronase(0.1 mg/ml) treatment. The strain produced two types of emulsifying materials during the growth on hydrocarbons; one was water-soluble extracellular materials and the other was cell wall-associated materials. Both emulsifying materials at lower concentration (0.12%) enhanced the oil-degrading activity of Moraxella sp. K12-7, which had medium emulsifying activity and negative cell hydrophobicity; however, it inhibited the oil-degrading activity of Pseudomunas sp. K12-5, which had medium emulsifying activity and cell hydrophobicity. These results suggest that the oil-degrading activity of Y. lipolytica 180 is closely associated with cell surface structure, and that a finely controlled application of Y.lipolytica 180 in combination with other oil-degrading microorganisms showed a possible enhancing efficiency of oil degradation.

  • PDF