• Title/Summary/Keyword: Asymmetry effect

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ASYMMETRIC LIGHT CURVES OF BLACK HOLE BINARIES AND THE DOPPLER BEAMING EFFECT (블랙흘 쌍성계의 비대칭 광도 곡선과 DOPPLER BEANING 효과)

  • 이희원;강영운;이창환
    • Journal of Astronomy and Space Sciences
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    • v.19 no.1
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    • pp.25-30
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    • 2002
  • Black hole binary candidates are known to be composed of a black hole with 10 $M_{\odot}$ and a K or M type companion. Because the companion is believed to fill the Roche lobe that is very aspherical, the light curves of black hole binaries are characterized by an ellipsoidal variation. It has been known that the ellipsoidal light curves exhibit asymmetric maximum brightness at the orbital phases 0.25 and 0.75, which has been attributed to star spots or the hot impact points of the accretion flow on to the accretion disk around the black hole. In this paper, it is pointed out that the special relativistic beaming effect contributes to the asymmetry of several percent often observed in the light curves. The typical orbital velocity 400 km $s^{-1}$ observed in black hole binaries may induce the temperature difference $\DeltaT/T$ ~ 1/400 of the late type companion star in the observer`s rest frame, because of the special relativistic Doppler beaming effect. This difference in temperature can result in several per cent of brightness sensitively dependent on the wavelength band, which is comparable to what has been observed in most black hole binary candidates. Considering the significant contribution of the special relativistic Doppler beaming effect, we conclude that the estimation of the sizes and temperatures of the star spots or the hot impact point needs serious revision.

Annealing Effect on Magneto-transport Properties of Amorphous Ge1-xMnx Semiconductor Thin Films (비정질 Ge1-xMnx 박막의 자기수송특성에 미치는 열처리 효과)

  • Kim, Dong-Hwi;Lee, Byeong-Cheol;Lan Anh, Tran Thi;Ihm, Young-Eon;Kim, Do-Jin;Kim, Hyo-Jin;Yu, Sang-Soo;Baek, Kui-Jong;Kim, Chang-Soo
    • Journal of the Korean Magnetics Society
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    • v.19 no.4
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    • pp.121-125
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    • 2009
  • Amorphous $Ge_1$_$_xMn_x$ semiconductor thin films grown by low temperature vapor deposition were annealed at various temperatures from 400 to $700^{\circ}C$ for 3 minutes in high vaccum chamber. The electrical and magnetotransport properties of as-grown and annealed samples have been studied. X-ray diffraction patterns analysis revealed that the samples still maintain amorphous state after annealling at $500^{\circ}C$ for 3 minutes and they were crystallized when annealing temperature increase to $600^{\circ}C$. Temperature dependence of resistivity measurement implied that as-grown and annealed $Ge_1$_$_xMn_x$ films have semiconductor characteristics, the increase of resistivity with annealling temperature was obseved. The $700^{\circ}C$-annealed sample exhibited negative magnetoresistance (MR) at low temperatures and the MR ratio was ${\sim}$8.5% at 10 K. The asymmetry was present in all MR curves. The anomalous Hall Effect was also observed at 250 K.

Determination of Thiamine in Pharmaceutical Preparations by Reverse Phase Liquid Chromatography Without Use of Organic Solvent

  • Suh, Joon Hyuk;Kim, Junghyun;Jung, Juhee;Kim, Kyunghyun;Lee, Seul Gi;Cho, Hyun-Deok;Jung, Yura;Han, Sang Beom
    • Bulletin of the Korean Chemical Society
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    • v.34 no.6
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    • pp.1745-1750
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    • 2013
  • A novel green aqueous mobile phase modified with room temperature ionic liquids (RTILs) was employed in the absence of volatile organic solvents or ion-pairing reagents to analyze thiamine, a very polar compound, by reverse phase high performance liquid chromatography (RP-HPLC). Due to its strongly hydrophilic nature, thiamine was eluted near the column dead time ($t_0$) using a mobile phase without adding RTILs or ion-pairing reagents, even if a 100% aqueous mobile phase, which has weak elution power under reverse phase conditions, was used. Thus, 1-ethyl-3-methyl-imidazolium hexafluorophosphate ([EMIM][$PF_6$]), which has the strongest chaotropic effect, was selected as a mobile phase additive to improve retention and avoid baseline disturbances at $t_0$. Various mobile phase parameters such as cation moiety, chaotropic anion moiety, pH and concentration of RTILs were optimized to determine thiamine at the proper retention time. Method validation was performed to assess linearity, intra- and inter-day accuracy and precision, recovery and repeatability; all results were found to be satisfactory. The developed method was also compared to the current official United States Pharmacopoeia (USP) and Korean Pharmacopoeia (KP) methods using an organic mobile phase containing an ionpairing reagent by means of evaluating various chromatographic parameters such as the capacity factor, theoretical plate number, peak asymmetry and tailing factor. The results indicated that the proposed method exhibited better efficiency of thiamine analysis than the official methods, and it was successfully applied to quantify thiamine in pharmaceutical preparations.

Case Study of Miso Facial Rejuvenation Acupuncture on Intractable Facial Palsy (중증 안면마비에 대한 미소안면침 증례보고)

  • Lee, Soh-Young;Ko, Jung-Min;Kim, Joo-Hee;Kwon, Hyo-Jung;Chung, Jie-Youn;Song, Jeong-Hwa;Choi, Do-Young;Lee, Jae-Dong;Lee, Sang-Hoon
    • Journal of Acupuncture Research
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    • v.26 no.1
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    • pp.163-171
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    • 2009
  • Objectives : This study was designed to evaluate the effect of Miso Facial rejuvenation Acupuncture on severe cases of facial palsy. Methods : Facial palsy patients over the age of 70 with House-Brackmann grading system(HBGS) above Grade V were treated with Miso Facial rejuvenation Acupuncture. The effects of the treatment were evaluated via scales and picture. Results : Before treatment with Miso Facial rejuvenation acupuncture, the three patients showed H-B Gr V. After treatment, they showed improvement to H-B Gr II, III, and II respectively. There also formed nasolabial folds on the palsied side, with better blinking of the eyes, and improved asymmetry of the left and right face. Conclusions : Miso Facial rejuvenation Acupuncture showed marked improvement in intractable facial palsy. Randomized-controlled trial for further evaluation will be needed in the future.

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Effects of Slope Changes During Body Weight-Supported Treadmill Training on Gait Characteristics in Patients With Hemiplegia

  • Hwang, Young-In;An, Duk-Hyun
    • Physical Therapy Korea
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    • v.15 no.4
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    • pp.10-17
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    • 2008
  • The purpose of this study was to determine the therapeutic effect of slope changes of the treadmill with body weight-supported training on gait characteristics in patients with hemiplegia. The volunteered subjects were divided into 3 groups based upon slope changes: control group ($0^{\circ}$ incline), $7^{\circ}$ group ($7^{\circ}$ incline), $12^{\circ}$ group ($12^{\circ}$ incline), They were trained the body weight-supported treadmill training (BWSTT) for 8 weeks. All subjects were supported up to 40% of their body weight on the treadmill training and the support was gradually decreased to 0~10% as the subjects were adapted to the training. There were significant improvements of walking velocity, step length of the affected side, the asymmetry ratio of step length in $7^{\circ}$ group (57.80 cm/s, 67.25 cm, .14), $12^{\circ}$ group (71.00 cm/s, 71.00 cm, .11) than control group (40.62 cm/s, 55.00 cm, .74) (p<.05): there were no differences between $7^{\circ}$ group and $12^{\circ}$ group in the all outcomes (p>.05). Both $7^{\circ}$ group and $12^{\circ}$ group scored higher than the control group in those outcomes and finally the effects of slopes changes of the treadmill were effective on gait characteristics of patients. But it s till remains undetermined what degree on the treadmill might be better to train the hemipareric patients. Therefore, more studies are required to look into minutely the changes of slopes of the treadmill influencing on gait characteristics.

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Effects of Muscle Strengthening Exercises Using a Thera Band on Lower Limb Function of Hemiplegic Stroke Patients (세라밴드를 이용한 근육강화운동이 뇌졸중 환자의 하지기능에 미치는 효과)

  • Han, Sang-Sook;Her, Jeong-Ja;Kim, Youn-Jung
    • Journal of Korean Academy of Nursing
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    • v.37 no.6
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    • pp.844-854
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    • 2007
  • Purpose: This study was to verify the effect of muscle strengthening exercises using a Thera-Band on the lower limbs. Methods: The design utilized for this study was a nonequivalent control group pretest-posttest design. A control group (16) and experimental group (16) were selected from stroke patients of K Oriental Medicine Hospital who were hospitalized for 5 months from December 2005 through April 2006. While only acupuncture therapy and physical therapy were used on the control group, acupuncture, physical therapy and additional muscle strengthening exercises using a red thera band were used on the experimental group. Muscle strengthening was performed 20 minutes per session, more than one session a day for 4 weeks. Hypotheses for this study were verified using Two-way repeated ANOVA and ANCOVA using a pre test score as a covariate. Results: The experimental group with thera band muscle strengthening exercises showed a decrease in asymmetry weight loading percentage(F=14.704, P= .010), range of knee (Z=-3.15, P= .001) & deep tendon reflex score(Z=-2.52, P= .012) and moving performance(F=12.328, P= .001)compared to the control group. Conclusion: It is confirmed that muscle strengthening exercises using a Thera-Band can be used as an effective nursing intervention to improve the function of the lower limb of hemiplegic stroke patients.

Pressure-Loss Characteristics of an Asymmetric Bifurcation Model of Human Lung Airways (비대칭 인체 기관지 분지관의 압력손실 특성)

  • Kang, Min-Yeong;Lee, Jin-Won
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.36 no.3
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    • pp.301-307
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    • 2012
  • The characteristics of pressure loss in an asymmetric bifurcating tube were investigated numerically for steady inspiratory conditions. The loss coefficient K calculated for various asymmetry and flow-distribution ratios found in human lung airways showed a power-law dependence on the Reynolds number (Re) and length-to-diameter ratio (L/d), with different exponents for Re $\geq$ 100 and Re < 100. The fundamental characteristics of the asymmetric bifurcation are similar to the case of symmetric bifurcation. In addition, the effect of skewed inlet velocity profiles on the pressure loss was weak, and decreased with an increasing number of bifurcations.

Effects of Therapeutic Exercise on Posture, Pain and Asymmetric Muscle Activity in a Patient with Forward Head Posture: case report (치료적운동이 전방두부자세 환자의 자세, 통증 및 비대칭적 근육활성에 미치는 영향: 증례보고)

  • Yoo, Kyung-Tae;Lee, Ho-Seong
    • Journal of the Korean Society of Physical Medicine
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    • v.11 no.1
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    • pp.71-82
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    • 2016
  • PURPOSE: The purpose of this case report was to determine the effect of therapeutic exercise on posture, pain, and muscle activity in two patients with forward head posture (FHP). METHODS: A-31-year-old male (patient A) and a 19-year-old women (patient B) presented with FHP, neck pain, and headache. The therapeutic exercise program consisted of cervical mobilization, deep cervical flexors strengthening, and cervical extensors stretching, for 40 min/d, 2 d/week, for 8 weeks. Neck pain (VAS), neck disability (NDI), cervical range of motion (CROM), lateral view of cervical spine X-ray (indicating the FHP), and asymmetrical neck and shoulder muscular activity ratio were measured before, after 4 weeks, and after 8 weeks of corrective exercise. RESULTS: VAS and NDI decreased in patients A and B after exercise compared to before the program. CROM increased in patients A and B at flexion, extension, side bending, and rotation after exercise compared to before the program. FHP decreased in patients A and B at distance after exercise compared to before the program. In addition, asymmetrical neck and shoulder muscles activity ratio improved in patients A and B after exercise compared to before the program. CONCLUSION: We demonstrated in a case report that therapeutic exercise increases ROM, decreases pain and disability of neck, FHP, and asymmetry muscle activity ratio in patients with FHP. These finding have clinical implications for therapeutic exercise in patients with FHP.

MAGNETIC PROPERTIES OF INNER MAGNETOSPHERE DURING GEOMAGNETIC STORMS INFERRED FROM A TSYGANENKO MAGNETIC FIELD MODEL

  • Lee, D.Y.;Kim, K.C.;Choi, C.R.;Kim, H.J.
    • Journal of Astronomy and Space Sciences
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    • v.21 no.4
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    • pp.303-314
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    • 2004
  • In this paper we report some properties of inner magnetospheric structure inferred from the T01_s code, one of the latest magnetospheric models by Tsyganenko. We have constructed three average storms representing moderate, strong, and severe intensity storms using 95 actual storms. The three storms are then modelled by the T01_s code to examine differences in magnetic structure among them. We find that the magnetic structure of intense storms is strikingly different from the normal structure. First, when the storm intensity is large, the field lines anchored at dayside longitudinal sectors become warped tailward to align to the solar wind direction. This is particularly so for the field lines anchored at the longitudinal sectors from postnoon through dusk. Also while for the moderate storm the equatorial magnetic field near geosynchronous altitude is found to be weakest near midnight sector, this depression region expands into even late afternoon sector during the severe storm. Accordingly the field line curvature radius at the equator in the premidnight geosynchronous region becomes unusually small, reaching down to a value less than 500 km. We attribute this strong depression and the dawn-dusk asymmetry to the combined effect from the enhanced tail current and the westward expansion/rotation of the partial ring current.

The BV Photometry of the RR Lyrae Star, BH Ursae Majoris: Light Curves and Period Study

  • Kim, Chun-Hwey;Jeong, Jang-Hae
    • Journal of Astronomy and Space Sciences
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    • v.28 no.2
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    • pp.109-116
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    • 2011
  • The first presented BV light curves of BH UMa confirmed Krajci's (2005) result that BH UMa is an RR Lyr star that belongs to the RRc subgroup. The light curves showed a slight asymmetry of D = 0.453 with an amplitude of about $0.^m58$ in B, $0.^m47$ in V, and $0.^m11$ in B-V and with a small hump between $0.^p82$ and $0.^p86$. We determined nine new times of minimum light and eight times of maximum light. We also analyzed all of the available unanalyzed minimum timings and found for the first time that the period of BH UMa has varied dramatically in at least three independent sinusoidal ways superposed on a secularly downward parabola over 66 years. The secular period decreasing rate was obtained as $6.^d684{\times}10^{-8}y^{-1}$, corresponding to -0.58 s/century. The semi-amplitude and period for each of the three sinusoidal variations were ($0.^d058$, $14.^y44$), ($0.^d044$, $9.^y98$), and ($0.^d005$, $0.^y97$), respectively. It is uncertain whether the periodicity for the shortest period of $0.^y97$ is real or spurious. The secular period decrease, well consistent with those of the other RRc stars, could be considered as a natural result of the evolution of the BH UMa system. The two possible sinusoidal terms were interpreted as both two light-time effects due to two additional bodies orbiting BH UMa and combinations of random fluctuations in the pulsation period of BH UMa. Two interpretations were shortly discussed with related parameters.