• Title/Summary/Keyword: TENSION RELEASE

Search Result 136, Processing Time 0.028 seconds

Cosmological Tests using Redshift Space Clustering in BOSS DR11

  • Song, Yong-Seon;Sabiu, Cristiano G.;Okumura, Teppei;Oh, Minji;Linder, Eric V.
    • The Bulletin of The Korean Astronomical Society
    • /
    • v.40 no.1
    • /
    • pp.43.3-44
    • /
    • 2015
  • We analyze the clustering of large scale structure in the Universe in a model independent method, accounting for anisotropic effects along and transverse to the line of sight. A large sample of 690,000 galaxies from The Baryon Oscillation Spectroscopy Survey Data Release 11 are used to determine the Hubble expansion H, angular distance D_A, and growth rate GT at an effective redshift of z=0.57. After careful bias and convergence studies of the effects from small scale clustering, we find that cutting transverse separations below 40 Mpc/h delivers robust results while smaller scale data leads to a bias due to unmodelled nonlinear and velocity effects. The converged results are in agreement with concordance LCDM cosmology, general relativity, and minimal neutrino mass, all within the $68{\backslash}%$ confidence level. We also present results separately for the northern and southern hemisphere sky, finding a slight tension in the growth rate -- potentially a signature of anisotropic stress, or just covariance with small scale velocities -- but within $68{\backslash}%$ CL.

  • PDF

Kinematical Analysis of Men's Pole Vault Event (장대높이뛰기 경기의 운동학적 분석)

  • Lim, Kyu-Chan
    • Korean Journal of Applied Biomechanics
    • /
    • v.13 no.3
    • /
    • pp.15-26
    • /
    • 2003
  • This study was conducted to investigate the performance times, CM position and CM speed, pole chord length and pole chord angle, whole body angular momentum(X axis), and grip width in pole vault event according to the event and phase; touch down, pole plant, take-off, maximum pole bending pole straight, pole release, peak height, and foot contact, pole contact, free flight. The pole vaulting of four male elite vaulters including six trial were filmed using two video digital cameras at 60 Hz at 56th national athletic match, and data were collected through the DLT method of three dimensional cinematography. In general the better jumper is, the longer the performance time is. And the greater CM speed is, and the better his transformation ability of CM horizontal speed into vertical speed is. As he uses a longer pole, his grip is higher, and it is a enough for him to rock back his body, so that he pulls and pushes the pole well keeping his hips close to. An greater maximum angular momentum and early positioning of the hips parallel to the bar makes his body far side of the bar and his bar clearance easier. Specially our national jumper needs to have more powerful braking force during foot contact phase, and take his body on the pole after maximum pole bending, and pull and push the pole strongly keeping his hips close to. Also he needs to have stronger muscular strength in order to control the longer pole and use the pole of proper tension more efficiently.

Fundamental Study on Mechanism of Strip Pinching in Rolling (압연 공정에서 꼬임 발생 메커니즘에 대한 기초 연구)

  • Lee Chang Woo;Shin Kee Hyun;Hong Wan Kee;Jung Dong Taek
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.21 no.12
    • /
    • pp.127-132
    • /
    • 2004
  • It is very important to find out causes of strip pinching for the high quality of products and fer the stable operation of rolling system. We have examined the strip pinching from three points of view to find out the causes of strip pinching in rolling system: strip shape, rolling operation conditions, and behavior of strip. Wedge, off center, and difference of rolling force through CMD(Cross machine direction) are found to possibly provide major initial causes of strip pinching. Generally strip pinching occurred in the tail of strip. Thus, computer simulations by using a FEM code were also carried out to find out the initial mechanism of strip pinching depending upon the force and geometric boundary conditions at the time of strip tail rolling. The strong compression force effect due to the sudden release of strip tail from the work roll and non-uniform strip tail shape (ex. Fish tail) across the CMD were found to provide possible major causes of strip pinching.

Effects of Ginseng Total Saponins and U-50,488H on Electrically Induced Twitch Responses of Mouse Vas Deferens (전기자극으로 유도된 마우스 수정관의 수축작용에 미치는 U-50,488H와 인삼사포닌의 영향)

  • Kim, Hack-Seang;Seong, Yeon-Hee;Kim, Sun-Hye;Kim, Suk-Chang;Choi, Kang-Ju;Oh, Ki-Wan
    • Journal of Ginseng Research
    • /
    • v.17 no.2
    • /
    • pp.109-113
    • /
    • 1993
  • The effects of ginseng total saponins (GTS) on the action of U-50,488H, a $textsc{k}$-opioid receptor agonist, on the electrically induced twitch responses of mouse vats deferens were studied. U-50,488H ($10^9$~$10^{-5}$M) inhibited the twitch contractions in a dose-dependent manner, which were caused by adenosine 5'-triphosphate (ATP) released from the stimulated sympathetic nerve, and this effect was antagonized by naloxone ($10^6$ M). GTS, which itself induced the inhibition of the twitch contractions, acted additively to U-50,488H, GTS and U-50,488H had no effect on the tension of the unstimulated organs. The contractions elicited by ATP were not affected by U-50,488H, but inhibited by GTS. These results suggest that U-50,488H suppressed the twitch contractions by the inhibition of neurotransmitter release from presynaptic nerve terminals via action on opioid receptor, but G75, by inhibiting the action of the neurotransmitter on the smooth muscle.

  • PDF

A Field Study of 「Toronto Birth Centre」 in the Perspective of a Public Service Strategy Coping with Low Birth-rate (저출산 대응 공공서비스 관점에서 본 「토론토 출산지원센터」 현지조사연구)

  • Lee, Yeunsook;Park, Jiyoung;Kim, Hyunjung
    • Journal of the Korean housing association
    • /
    • v.26 no.1
    • /
    • pp.31-41
    • /
    • 2015
  • Korea has shown the lowest birth rate among OECD countries for over 10 years. This caused various social tensions and problems including negative impacts on national economy. To deal with these problems and to cope with future risk, diverse strategies must be actively explored. The purpose of this research is to delineate the characteristics of Toronto Birth Centre in Canada which was established currently to support families. Field visit study was the major methodology which includes interview with a staff and walk-through guided observation accompanied by visual recording. As a result, the specific functions and the logic of utilizing the center along with its spatial characteristics were delineated. The result has significant implication in developing coping strategies to release the social tension. The birth center can be an efficient strategy to include as a public strategy to Korean Society who has suffered from long lasting lowest birth rate.

Modeling the Influence of Gas Pressure on Droplet Impact Using a Coupled Gas/liquid Boundary Element Method

  • Park, Hong-Bok;Yoon, Sam S.;Jepsen Richard A.;Heister Stephen D.
    • Journal of ILASS-Korea
    • /
    • v.11 no.2
    • /
    • pp.89-97
    • /
    • 2006
  • An inviscid axisymmetric model capable of predicting droplet bouncing and the detailed pre-impact motion, influenced by the ambient pressure, has been developed using boundary element method (BEM). Because most droplet impact simulations of previous studies assumed that a droplet was already in contact with the impacting substrate at the simulation start, the previous simulations could not accurately describe the effect of the gas compressed between a failing droplet and the impacting substrate. To properly account for the surrounding gas effect, an effect is made to release a droplet from a certain height. High gas pressures are computationally observed in the region between the droplet and the impact surface at instances just prior to impact. The current simulation shows that the droplet retains its spherical shape when the surface tension energy is dominant over the dissipative energy. When increasing the Weber number, the droplet surface structure is highly deformed due to the appearance of the capillary waves and, consequently, a pyramidal surface structure is formed; this phenomenon was verified with our experiment. Parametric studies using our model include the pre-impact behavior which varies as a function of the Weber number and the surrounding gas pressure.

  • PDF

Oxygen matters: hypoxia as a pathogenic mechanism in rhinosinusitis

  • Cho, Hyung-Ju;Kim, Chang-Hoon
    • BMB Reports
    • /
    • v.51 no.2
    • /
    • pp.59-64
    • /
    • 2018
  • The airway epithelium is the first place, where a defense mechanism is initiated against environmental stimuli. Mucociliary transport (MCT), which is the defense mechanism of the airway and the role of airway epithelium as mechanical barriers are essential in innate immunity. To maintain normal physiologic function, normal oxygenation is critical for the production of energy for optimal cellular functions. Several pathologic conditions are associated with a decrease in oxygen tension in airway epithelium and chronic sinusitis is one of the airway diseases, which is associated with the hypoxic condition, a potent inflammatory stimulant. We have observed the overexpression of the hypoxia-inducible factor 1 (HIF-1), an essential factor for oxygen homeostasis, in the epithelium of sinus mucosa in sinusitis patients. In a series of previous reports, we have found hypoxia-induced mucus hyperproduction, especially by MUC5AC hyperproduction, disruption of epithelial barrier function by the production of VEGF, and down-regulation of junctional proteins such as ZO-1 and E-cadherin. Furthermore, hypoxia-induced inflammation by HMGB1 translocation into the cytoplasm results in the release of IL-8 through a ROS-dependent mechanism in upper airway epithelium. In this mini-review, we briefly introduce and summarize current progress in the pathogenesis of sinusitis related to hypoxia. The investigation of hypoxia-related pathophysiology in airway epithelium will suggest new insights on airway inflammatory diseases, such as rhinosinusitis for clinical application and drug development.

Design and Fabrication of a 3 Chopstick Gripper for Microparts (미세 물체 조작을 위한 3젓가락형 집게의 설계 및 제작)

  • 박종규;문원규
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • 1997.10a
    • /
    • pp.1067-1071
    • /
    • 1997
  • A new type of gripper for micrometer-size objects is developed using piezoelectric multi-layer benders. It is composed of three chopsticks, two of which are designed to grip micro-objects. The third one is reserved for helping the two when objects are released from the chopsticks. It is well known that a micro object is much easier to grasp than to release it after holding it. The electrostatic force between the chopsticks and an object is believed to be the main cause of adhesion in a dry environment. The surface tension becomes very important when liquids are present or in a liquid. The third auxiliary chopsticks is introduced to solve there surface effects. All the three chopsticks are made of tungsten wires with sharpened ends by etching. When grasping microparts, the two chopsticks are utilized, and, when releasing them anywhere the parts are located, the third one reduces the electrostatic force between the objects and the chopstick may be to help the other two chopsticks to hold an objects in a desired orientation. We constructed the three chopstick gripoer for micro objects and test their function by holding and releasing an object of a diameter of 100 micrometers. We make use of open loop voltage control. The bender displacement resolution is sub-micrometer. The gripping forces, about tens of mN are obtained. The experiment shows that the third auxiliary chopstick functions effectively.

  • PDF

Fundamental Study on Pinching Mechanism in Hot Strip Mill (사상 압연 공정에서 꼬임 발생 메커니즘에 대한 기초 연구)

  • 신기현;권순오;이창우;안영세;정동택;홍완기
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • 2003.06a
    • /
    • pp.1091-1096
    • /
    • 2003
  • It is very important to find out causes of strip pinching for the high quality of products and for the stable operation of hot roiling system. We have examined the strip pinching from three points of view to find out the causes of strip pinching in hot rolling system: strip shape, rolling operation conditions, and behavior of strip. Wedge, off center, and difference of rolling force through CMD are found to possibly provide major initial causes of strip pinching. Generally strip pinching occurred in the tail of strip. Thus, computer simulations by using a FEM code were also carried out to find out the initial mechanism of strip pinching depending upon the force and geometric boundary conditions at the time of strip tail rolling. The strong compression force effect due to the sudden release of strip tail from the work roll and non-uniform strip tail shape (ex. Tongue tail) across the CMD were found to provide possible major causes of strip pinching.

  • PDF

Botulinum Toxin : Basic Science and Clincal Uses in Otolaryngology (Botulinum Toxin : 기초과학과 이비인후과 영역에서의 임상적 사용)

  • 최홍식;문인석;김한수;김현직
    • Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
    • /
    • v.13 no.2
    • /
    • pp.164-172
    • /
    • 2002
  • The role of botulinum toxin as a therapeutic agent is expanding rapidly in otolaryngology. Botulinum toxin is a protease that blocks the release of acetylcholine from nerve terminals. Its effects are transient and nondestructive, and largely limited to the area in which it is administered These effects are also graded according to the dose, allowing for individualized treatment of patients and disorders. Botulinum toxin has been used primarily to treat disorders of excessive or inappropriate muscle contraction. In the field of otolaryngology, these include spasmodic dysphonia, oromandibular dystonia, and blepharospasm, vocal tics and stuttering, cricopharyngeal achalasia, various tremors and tics, hemifacial spasm, temporomandibular joint disorders and a number of cosmetic applications. Botulinum toxin treatment has recently begun to show some benefit in the control of pain from migraine and tension headache. It may also prove useful in the control of autonomic dysfunction, as in Frey syndrome, sialorrhea, and rhinorrhea. In over 20 yews of use in humans, botulinum toxin has accumulated a considerable safety record, and in many cases represents relief for thousands of patients unaided by other therapy.

  • PDF