• Title/Summary/Keyword: Dumbbell

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Brownian Dynamics Simulation Study on the Anisotropic FENE Dumbbell Model for Concentrated Polymer Solution and the Melt

  • Sim, Hun Gu;Lee, Chang Jun;Kim, Un Jeon;Bae, Hyeong Seok
    • Bulletin of the Korean Chemical Society
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    • v.21 no.9
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    • pp.875-881
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    • 2000
  • We study the rheological properties of concentrated polymer solution and the melt under simple shear and elon-gational flow using Brownian dynamicssimulation. In order to describe the anisotropic molecular motion, we modifiedthe Giesekus' mobility tensor by incorporating the finitely extensible non-linear elastic (FENE) spring force into dumbbell model. To elucidate the nature of this model, our simulation results are compared with the data of FENE-P ("P"standsfor the Perterin) dumbbell model and experiments. While in steady state both original FENE and FENE-P models exhibit a similar viscosity response,the growthof viscosity becomes dissimilar as the anisotropy decreases and the flowrate increases. The steady state viscosity obtained from the simulation well describes the experiments including the shear-thinning behavior in shear flow and viscosity-thinning behavior in elongational flow. But the growth of viscosity oforiginal FENE dumbbell model cannot describe the experimental results in both flow fields.

The Effects of Dumbbell, Walking, and Yoga Exercise Interventions for the Community-Dwelling Women (성인여성의 덤벨운동, 걷기운동 및 요가운동중재 효과)

  • Shin, Kyung Rim;Kang, Youn Hee;Choi, Kyung Ae;Baek, Hyo Jin;Choi, Mi Jin;Yun, Ok Jong
    • Korean Journal of Adult Nursing
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    • v.18 no.5
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    • pp.771-780
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    • 2006
  • Purpose: The purpose of this study was to examine the effects of exercise intervention, including dumbbell(weight lifting), walking, and yoga, on the body composition, physiologic factors, body image, and perceived health in the community-dwelling women. Method: This study utilized pretest-posttest design with three types of exercise interventions. The types of exercise intervention included dumbbell, walking, and yoga. Results: A total of 136 subjects were included: 49 for dumbbell, 67 for walking, and 20 for yoga. As measures of body composition, BMI, body weight, and body fat rate were significantly improved only after dumbbell intervention(p<.01). Systolic blood pressures were significantly decreased in the groups of dumbbell and walking. Diastolic blood pressure was significantly declined only in the walking group. Vital capacities and body image were improved in all groups(p<.01). However, total cholesterol levels were not improved in all groups(p>.05) and none of the measures for perceived health state were not significantly changed in all groups(p>.05). Conclusion: From the findings of this study, it was demonstrated that the effects of exercise interventions were differentiated by their types and variables to be affected. Therefore, future studies that apply the tailored exercise intervention to each age-categorical group are needed.

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Electrochemical Synthesis of Dumbbell-like Au-Ni-Au Nanorods and Their Surface Plasmon Resonance

  • Park, Yeon Ju;Liu, Lichun;Yoo, Sang-Hoon;Park, Sungho
    • Journal of Electrochemical Science and Technology
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    • v.3 no.2
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    • pp.57-62
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    • 2012
  • In this report, we demonstrate that the longitudinal localized surface plasmon resonance mode can be suppressed when the nanorods were in dumbbell shape. The seed nanorods were synthesized by electrochemical deposition of metals into the pores of anodic aluminum oxide templates. The dumbbell-like nanorods were grown from seed Au-Ni-Au nanorods by a rate-controlled seed-mediated growth strategy. The selective deposition of Au atoms onto Au blocks of Au-Ni-Au nanorods produced larger diameter of Au nanorods with bumpy surface resulting in dumbbell-like nanorods. The morphology of nanorods depended on the reduction rate of $AuCl_4^-$, slow rate producing smooth surface of Au nanorods, but high reduction rate producing bumpy surface morphology. Through systematic investigation into the UV-Vis-NIR spectroscopy, we found that the multiple localized surface plasmon resonance (LSPR) modes were available from single-component Au nanorods. And, their LSPR modes of Au NRs with bumpy surface, compared to the smooth seed Au NRs, were red-shifted, which was obviously attributed to the increased electron oscillation pathways. While the longitudinal LSPR modes of smoothly grown Au NRs were blue-shifted except for a dipole transverse LSPR mode, which can be interpreted by decreased aspect ratio. In addition, dumbbell-like nanorods showed an almost disappeared longitudinal LSPR mode. It reflects that the plasmonic properties can be engineered using complex nanorods structure.

One Stage Posterior Minimal Laminectomy and Video-Assisted Thoracoscopic Surgery (VATS) for Removal of Thoracic Dumbbell Tumor

  • Nam, Kyoung Hyup;Ahn, Hyo Yeoung;Cho, Jeong Su;Kim, Yeoung Dae;Choi, Byung Kwan;Han, In Ho
    • Journal of Korean Neurosurgical Society
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    • v.60 no.2
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    • pp.257-261
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    • 2017
  • Objective : This study was conducted to assess the surgical results of one-stage posterior minimal laminectomy and video-assisted thoracoscopic surgery (VATS) for the treatment of thoracic dumbbell tumor and to describe its precise technique. In addition, we investigated the technique's usefulness and limitations. Methods : Seven cases of thoracic dumbbell tumor (two men and five women, mean age, 43 years) were analyzed retrospectively. Pathological findings included schwannoma in four patients, neurofibroma in two patients, and hemangioma in one patient. The location of tumors varied from T2/3 to T12/L1. Dumbbell tumors were resected by one-stage operation using posterior laminectomy followed by VATS without instrumentation. Clinical data were reviewed. Results : The mean follow-up period was 25 months (range, 3-58 months), and the operative time ranged from 255 to 385 min (mean, 331 min), with estimated blood loss ranging from 110 to 930 mL (mean, 348 mL). The tumor was completely resected without instrumentation and postoperative instability in all cases. Postoperative complications included atelectasis and facial anhydrosis in one case each. Conclusion : One-stage posterior minimal laminectomy and VATS may be a safe and less invasive technique for removal of thoracic dumbbell tumor without instability. This method has the advantage of early ambulation and rapid recovery because it reduces blood loss and postoperative pain.

A Dumbbell-Shaped Meningioma Mimicking a Schwannoma in the Thoracic Spine

  • Kim, Myeong-Soo;Eun, Jong-Pil;Park, Jeong-Soo
    • Journal of Korean Neurosurgical Society
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    • v.50 no.3
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    • pp.264-267
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    • 2011
  • A 50-year-old man presented bilateral hypesthesia on and below the T6 dermatome and paresthesia. Magnetic resonance imaging (MRI) showed an intraspinal extradural tumor, which located from the 6th thoracic vertebral body to the upper margin of the 7th vertebral body, continuing dumbbell-like through the intervertebral foramen into the right middle thorax suggesting a neurogenic tumor (neurofibroma or neurilemmoma). With the patient in a prone position, we exposed and excised the tumor via a one stage posterior approach through a hemi-laminictomy of T6. Histologic examination showed a grade 1 meningothelial meningioma, according to the World Health Organization classification. Initially, we assumed the mass was a schwannoma because of its location and dumbbell shape. However, the tumor was actually a meningioma. Postoperatively, hypesthesia resolved completely and motor power of the leg gradually full recovered. A postoperative MRI revealed no evidence of residual tumor.

Orientation and deformation of FENE dumbbells in confined microchannel and contraction flow geometry

  • Song, Sun-Jin;Kim, Ju-Min;Ahn, Kyung-Hyun;Lee, Seung-Jong;Yeo, Jong-Kee
    • Korea-Australia Rheology Journal
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    • v.19 no.3
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    • pp.147-156
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    • 2007
  • The orientation and deformation of polymer chains in a confined channel flow has been investigated. The polymer chain was modeled as a Finitely Extensible Nonlinear Elastic (FENE) dumbbell. The Brownian configuration field method was extended to take the interaction between the flow and local chain dynamics into account. Drag and Brownian forces were treated as anisotropic in order to reflect the influence of the wall in the confined flow. Both Poiseuille flow and 4 : 1 contraction flow were considered. Of particular interest was molecular tumbling of polymer chains near the wall. It was strongly influenced by anisotropic drag and high shear close to the wall. We discussed the mechanism of this particular behavior in terms of the governing forces. The dumbbell configuration was determined not only by the wall interaction but also by the flow type of the geometric origin. The effect of extensional flow on dumbbell configuration was also discussed by comparing with the Poiseuille flow.

Analysis of the Coordination Relationship and Muscle Fatigue of Agonist and Synergist During Dumbbell Side Lateral Raise Using Biosignals (생체신호를 이용한 덤벨 사이드 레터럴 레이즈 시 주동근과 협력근의 협응 관계 및 근피로 분석)

  • Jong min Kim;Chang hyun Song;Jun won Choi ;Han Sung Kim
    • Journal of Biomedical Engineering Research
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    • v.44 no.3
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    • pp.218-224
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    • 2023
  • This study aimed to analyze the coordination of muscle and muscle fatigue between biceps, lateral deltoid, and anterior deltoid during dumbbell side lateral raise using bio-signal. One male subject performed dumbbell side lateral raise with 3% of 1RM dumbbell at the rate of 30bpm until failure (8 minutes). While performing, ECG were recorded to observe the participant's performance. EMG were recorded from biceps, lateral deltoid, and anterior deltoid for observing coordination and fatigue. ECG were analyzed in time and frequency domain to observe Heart rate, normLF, normHF. Changes in heart rate, normLF, and normHF indicate that the sympathetic nervous system is activated, while changes in median frequency (MDF) indicate the occurrence of muscle fatigue. Moreover, the coordination relationship of muscle changed. The correlation of MDF between each muscles indicated that lateral deltoid is associated with biceps and anterior deltoid. These results showed that our study can contribute to improving understanding of muscle fatigue and muscle coordination relationships.

The Converge Effects of Kaatsu Treatment on Body Compositions, Physical Fitness and Dynamic and Static Balance during Unmilled Rice Dumbbell Exercise in Older Women (현미덤벨 운동시 가압처치가 노인여성의 신체구성, 체력과 동적 및 정적평형성에 미치는 융합적 효과)

  • Byun, Jae-Chul
    • Journal of the Korea Convergence Society
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    • v.9 no.4
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    • pp.261-269
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    • 2018
  • The purpose of this study was to determined the converge effects of Kaatsu treatment on body compositions, physical fitness and dynamic and static balance during unmilled rice dumbbell exercise in older women. They are divided into three groups(Kaatsu treatment+exercise, n=12, non-Kaatsu treatment+exercise, n=11, Control, n=12). In this study, there were a no significant differences on body weight and lean body mass and body mass index between the group, but there was a significant differences on percent of body fat between the group(P<.001). There was a significant differences on left grip strength between the group, and significant differences on flexibility and agility after the unmilled rice dumbbell exercise training. There were a significant differences on the dynamic and static balance between the group after the unmilled rice dumbbell exercise training(respectively P<.001, P<.05).

Design of Dumbbell-type CPW Transmission Lines in Optoelectric Circuit PCBs for Improving Return Loss (광전회로 PCB에서 반사특성 개선을 위한 덤벨 형태의 CPW 전송선 설계)

  • Lee, Jong-Hyuk;Kim, Hwe-Kyung;Im, Young-Min;Jang, Seung-Ho;Kim, Chang-Woo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.35 no.4A
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    • pp.408-416
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    • 2010
  • A dumbbell-type CPW transmission-line structure has been proposed to improve the return loss of the transmission line between a driver IC and flip-chip-bonding VCSEL(Vertical Cavity Surface Emitting Laser) in a hybrid opto-electric circuit board(OECB). The proposed structure used a pair of dummy ground solder balls on the ground lines for flip-chip bonding of the VCSEL and designed the dumbbell-type CPW transmission line to improve reflection characteristics. The simulated results revealed that the return loss of the dumbbell-type CPW transmission line was 13-dB lower than the conventional CPW transmission line. A 4-dB improvement in the return loss was obtained using the dummy ground solder balls on the ground lines. The variation rate of the reflection characteristic with the variation of terminal impedances of the transmission line (at the output terminal of the driver IC and the input terminal of the VCSEL) is about ${\pm}2.5\;dB$.

Self-assembly of Dumbbell-shaped Rod Amphiphiles Based on Dodeca-p-phenylene

  • Huang, Zhegang;Liu, Libin;Lee, Eun-Ji;Lee, Myong-Soo
    • Bulletin of the Korean Chemical Society
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    • v.29 no.8
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    • pp.1485-1490
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    • 2008
  • Dumbbell-shaped aromatic amphiphilic molecules consisting of a dodeca-p-phenylene as a rigid segment and oligoether dendrons as a flexible chains were synthesized, characterized, and their aggregation behavior was investigated in the bulk and at the air-water interface. In contrast to the molecule 2 which shows a nematic liquid crystalline state, molecule 1 based on shorter dendritic chains was observed to self-assemble into a 3-D primitive orthorhombic supercrystal. And molecule 1 at the air-water interface was observed to reorganize from circular plates to ring structures by lateral compressions.