• Title/Summary/Keyword: spiral

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The Effects of Spiral Taping Treatment on Low Back Pain (요통에 대한 첩대(스파이랄 테이핑)요법의 효과)

  • Hwang, Jae-Ok;Seo, Jung-Chul
    • Journal of Pharmacopuncture
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    • v.9 no.1
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    • pp.103-107
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    • 2006
  • Objective : The purpose of this study is to estimate the effects of spiral taping treatment on low back pain. Methods : 420 low back pain patients were treated with spiral taping or spiral taping plus herbal medicine, and no other treatments such as acupuncture, herbal acupuncture, and chiropractic therapy were added. We evaluated the improvement by physical examination and pain. Results : 364 patients felt no pain or inconvenience of daily life and 43 patients showed improvement of pain or symptom after 1 month of treatment. 13 patients showed same pain with before treatment. Conclusion : These results suggest spiral taping treatments contribute to the improvement of low back pain. Further study is needed for the confirmation of this effect of spiral taping treatments on low back pain.

Spiral Casing of a Volute Centrifugal Pump - Effects of the Cross Sectional Shape - (볼류트 원심펌프의 스파이럴 케이싱 - 단면 형상의 영향 -)

  • Jin, Hyun Bae;Kim, Myung Jin;Son, Chang Ho;Chung, Wui Jun
    • The KSFM Journal of Fluid Machinery
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    • v.16 no.4
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    • pp.28-34
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    • 2013
  • Centrifugal pump consists of a axis, a impeller and a spiral casing. The impeller is the most important component in centrifugal pump. But to minimize flow loss in discharge passage including spiral casing, the shape of spiral casing is very important also. So, to investigate the effect of shape of the spiral casing on performance curve of pump, the characteristics of spiral casing were studied through numerical analysis for centrifugal pump used on industry field. From the results the rectangular model was showed more loss than the others because of asymmetric flow field.

Cavity-backed Two-arm Spiral Antenna with a Ring-shaped Absorber for Partial Discharge Diagnosis

  • Kim, Han-Byul;Hwang, Keum-Cheol;Kim, Hyeong-Seok
    • Journal of Electrical Engineering and Technology
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    • v.8 no.4
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    • pp.856-862
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    • 2013
  • A cavity-backed two-arm spiral antenna for partial discharge diagnosis is presented. The proposed antenna consists of a two-arm Archimedean spiral, a tapered microstrip balun as spiral antenna feed, and a ring-shaped absorber-loaded cavity. The Archimedean spiral antenna is designed for the operating frequency band of 0.3 GHz to 1.5 GHz and fed by the tapered microstrip balun. The cavity is utilized to transform the bidirectional beam into a unidirectional beam, thereby enhancing gain. The ring-shaped absorber is stacked in the cavity to reduce the reflected waves from the cavity wall. The proposed antenna is designed and simulated using CST Microwave Studio. A prototype of the proposed antenna is likewise fabricated and tested. The measured radiation patterns are directional to the positive z-axis, and the measured peak gain is 8.13 dBi at a frequency of 1.1 GHz.

Experimental and numeral investigation on self-compacting concrete column with CFRP-PVC spiral reinforcement

  • Chen, Zongping;Xu, Ruitian
    • Earthquakes and Structures
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    • v.22 no.1
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    • pp.39-51
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    • 2022
  • The axial compression behavior of nine self-compacting concrete columns confined with CFRP-PVC spirals was studied. Three parameters of spiral reinforcement spacing, spiral reinforcement diameter and height diameter ratio were studied. The test results show that the CFRP strip and PVC tube are destroyed first, and the spiral reinforcement and longitudinal reinforcement yield. The results show that with the increase of spiral reinforcement spacing, the peak bearing capacity decreases, but the ductility increases; with the increase of spiral reinforcement diameter, the peak bearing capacity increases, but has little effect on ductility, and the specimen with the ratio of height to diameter of 7.5 has the best mechanical properties. According to the reasonable constitutive relation of material, the finite element model of axial compression is established. Based on the verified finite element model, the stress mechanism is revealed. Finally, the composite constraint model and bearing capacity calculation method are proposed.

Local TIGRESS Simulations of Star Formation in Spiral Galaxies

  • Kim, Woong-Tae;Kim, Chang-Goo;Ostriker, Eve C.
    • The Bulletin of The Korean Astronomical Society
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    • v.46 no.1
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    • pp.51.1-51.1
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    • 2021
  • Spiral arms greatly affect gas flows and star formation in disk galaxies. We use local 3D simulations of vertically-stratified, self-gravitating, gaseous disks under a stellar spiral potential to study the effects of spiral arms on galactic star formation as well as formation of gaseous spurs/feathers. We adopt the TIGRESS framework to handle radiative heating and cooling, star formation, and ensuing supernova (SN) feedback. We find that more than 90% of star formation takes place inside spiral arms. The global star formation rate (SFR) in models with spiral arms is enhanced by less than a factor of 2 compared to the no-arm counterpart. This supports the picture that spiral arms do not trigger star formation but rather redistribute star-forming regions. Correlated SN feedback produces interarm feathers in both magnetized and unmagnetized models. These feathers live short, have parallel magnetic fields along their length, and are bounded by SN feedback in the lateral direction, in contrast to instability-induced feathers formed in our previous isothermal simulations.

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Estimation of Confinement Effectiveness Factor for Confining Stress by Spiral (나선근에 의한 횡보강 응력 계산을 위한 횡보강 유효 계수의 산정법)

  • 김진근;박찬규
    • Proceedings of the Korea Concrete Institute Conference
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    • 1995.04a
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    • pp.280-285
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    • 1995
  • In order to predict the behavior of column confined with spirals, the accurate estimation of confining stress by spiral is very important, Thus a number of models have been proposed for calculating the confining stress by spiral. However, in these equations, it was not considered the effects of the difference of mechanical characteristics related to the application of high strength concrete and spiral in structures. In this study, a model equation for calculation of the confining stress by spiral was proposed based on the test results investigated here. The proposed equation included the effects of concrete strength, spacing and yield strength of spirals

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RESONANCE EXCITATION AND THE SPIRAL-RING STRUCTURE OF DISK GALAXIES

  • YUAN CHI
    • Journal of The Korean Astronomical Society
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    • v.29 no.spc1
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    • pp.45-48
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    • 1996
  • Rings are common in disk galaxies. These rings are either indistinguishable from a pair of tightly wound spirals, or themselves are a part of the spiral structure. Furthermore, their occurrence is seen coincident with a bar in the center. In this paper, we interpret this spiral-ring structure as density waves resonantly excited by a rotating bar potential. The theory gives excellent agreement for the molecular spiral-rings in central parts. of nearby disk galaxies, observed by high resolution radio arrays. The same mechanism works for more distant spiral-rings in the outer parts of disk galaxies qualitatively, although the problem is complicated by the coupling of the stellar and gaseous disks.

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Comparison of Target Localization Error between Conventional and Spiral CT in Stereotactic Radiosurgery

  • Kim, Jong-Sik;Ju, Sang-Kyu;Park, Young-Hwan
    • The Journal of Korean Society for Radiation Therapy
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    • v.12 no.1
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    • pp.20-25
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    • 2000
  • The accuracy of the target localization was evaluated by conventional and spiral CT in stereotactic radiosurgerv. Conventional and spiral CT images were obtained with geometrical phantom, which was designed to produce exact three-dimensional coordinates of several objects within 0.1mm error range. Geometrical phantom was attached by BRW headframe, intermediate head ring, and CT localizer. Twentv-seven slices of conventional CT image were scanned at 3 mm slice thickness. Spiral CT images were scanned at 3 mm slice thickness from the pitch value 1 to 3, and twenty-seven slices of image were obtained per each the pitch value. These CT images were transferred to a treatment planning system(X-knife, Radionics) by ethernet, Three-dimensional coordinates of these images measured from the treatment planning system were compared to known values of geometrical phantom. The mean localization error of the target localization of conventional CT was 1.4mm. In case of spiral CT, the error of the target localization was within 1.6mm from the pitch value 1 to 1.3, but was more than 30mm above the pitch value 1.5. In conclusion, as the localization error of spiral CT was increased in high pitch value compared to conventional CT, the application of spiral CT will be with caution in stereotactic radiosurgery.

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Effect of spiral reinforcement on flexural-shear-torsional seismic behavior of reinforced concrete circular bridge columns

  • Belarbi, Abdeldjelil;Prakash, Suriya;You, Young-Min
    • Structural Engineering and Mechanics
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    • v.33 no.2
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    • pp.137-158
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    • 2009
  • This paper investigates the behavior of reinforced concrete (RC) circular columns under combined loading including torsion. The main variables considered in this study are the ratio of torsional moment to bending moment (T/M) and the level of detailing for moderate and high seismicity (low and high transverse reinforcement/spiral ratio). This paper presents the results of tests on seven columns subjected to cyclic bending and shear, cyclic torsion, and various levels of combined cyclic bending, shear, and torsion. Columns under combined loading were tested at T/M ratios of 0.2 and 0.4. These columns were reinforced with two spiral reinforcement ratios of 0.73% and 1.32%. Similarly, the columns subjected to pure torsion were tested with two spiral reinforcement ratios of 0.73% and 1.32%. This study examined the significance of proper detailing, and spiral reinforcement ratio and its effect on the torsional resistance under combined loading. The test results demonstrate that both the flexural and torsional capacities are decreased due to the effect of combined loading. Furthermore, they show a significant change in the failure mode and deformation characteristics depending on the spiral reinforcement ratio. The increase in spiral reinforcement ratio also led to significant improvement in strength and ductility.