• Title/Summary/Keyword: meniscus effect

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Flow and Heat Transfer Characteristics of the Evaporating Extended Meniscus in a Micro Parallel Plate (마이크로 평판내 증발에 의한 확장초승달영역의 열/유동특성)

  • Park, Kyong-Woo;Noh, Kwan-Joong;Lee, Kwan-Soo
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.27 no.4
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    • pp.476-483
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    • 2003
  • A mathematical model is presented to predict the two-phase flow and heat transfer phenomena of the evaporating extended meniscus region in a micro-channel. The pressure difference at the liquid-vapor interface can be obtained by the augmented Laplace-Young equation. The correlative equations for film thickness, pressure, and velocity in the meniscus region are derived by applying the mass, momentum, and energy equations into the control volume. The results show that increasing the heat flux and the liquid inlet velocity cause the length and liquid film thickness of the extended meniscus region to decrease. The variation, however, of the heat flux and liquid inlet velocity has no effect on the profile of film thickness. The majority of heat is transferred through the thin film region that is a very small region in the extended meniscus region. It is also found that the vapor velocity increases gradually in the meniscus region. However, it increases sharply at the junction of the meniscus and thin film regions.

Effect of Traditional Korean Medicine Treatments on the Discoid Meniscus of Knee Joint: Two Clinical Cases

  • Yoon-Jae Won;Sun-Woo Kang;Myeong-Yeol Yang;Jae-Joon Ha;Ji-Sun Kim;Hong-Wook Choi;Gyu-Bin Lee
    • Journal of Acupuncture Research
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    • v.40 no.1
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    • pp.90-96
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    • 2023
  • The discoid meniscus is an innate modified form of the meniscus, characterized by middle hypertrophy and a larger than the regular diameter, leading to an absence of the characteristic "C" arrangement. Previously, no study has reported the traditional Korean medicine treatment of knee pain mainly due to discoid meniscus. Here, we report two cases of a discoid meniscus of the knee as the cause of knee pain. Patients were diagnosed with magnetic resonance imaging for discoid meniscus and received traditional Korean medicine treatments, including pharmacopuncture, acupuncture, herbal medicine, and chuna. The pain was alleviated when assessed by patient-reported pain scale scores, and the general knee condition was improved. Thus, traditional Korean medicine treatments could be effective for patients who had discoid meniscus of the knee joint in this case report.

Geometry Effects of Capillary on the Evaporation from the Meniscus (모세관 단면 형상에 따른 계면 및 증발 특성)

  • Choi, Choong-Hyo;Jin, Songwan;Yoo, Jung-Yul
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.31 no.4
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    • pp.313-319
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    • 2007
  • The effect of capillary cross-section geometry on evaporation is investigated in terms of the meniscus shape, evaporation rate and evaporation-induced flow for circular, square and rectangular cross-sectional capillaries. The shapes of water and ethanol menisci are not much different from each other in square and rectangular capillaries even though the surface tension of water is much larger than that of ethanol. On the other hand, the shapes of water and ethanol menisci are very different from each other in circular capillary. The averaged evaporation fluxes in circular and rectangular capillaries are measured by tracking the meniscus position. At a given position, the averaged evaporation flux in rectangular capillaries is much larger than that in circular capillary with comparable hydraulic diameter. The flow near the evaporating meniscus is also measured using micro-PIV, so that the rotating vortex motion is observed near the evaporating ethanol and methanol menisci except for the case of methanol meniscus in rectangular capillary. This difference is considered to be due to the existence of corner menisci at the four comers.

The Analysis of Dynamic Pressure in the Molten Flux near the Meniscus during Mold Oscillation for the Continuous Casting of Steel (강의 연속주조시 Mold Oscillation에 따른 Flux층 내의 동적 압력변화 해석)

  • Park, Tae-Ho;Kim, Ji-Hun;Choi, Joo;Ye, Byung-Joon
    • Journal of Korea Foundry Society
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    • v.24 no.1
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    • pp.26-33
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    • 2004
  • The pressure of the mold flux acting on the meniscus shell was investigated through the coupling analysis of heat transfer in the mold and fluid flow in the flux caused by the mold oscillation. Finite element method was employed to solve the conservation equation associated with appropriate boundary conditions. As reported by previous workers, the axial pressure is positive on the negative strip time and negative on the positive strip time. A maximum pressure is predicted toward the top of the meniscus shell which has the thin shell arid a maximum value is in proportion to the relative mold oscillation velocity. The relative mold oscillation velocity was changed by the effect of meniscus level fluctuation. Therefore the pressure of the mold flux acting on the meniscus shell was different each cycle of the mold oscillation due to the irregularity of relative mold oscillation velocity.

A Review of the Korean Traditional Medicine Treatment for Meniscus Injury (반월상 연골판 손상의 한의학적 치료에 대한 국내외 최신 연구 동향 분석)

  • Han, Sihoon;Oh, Taeyoung;Oh, Minseok
    • The Journal of Korean Medicine
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    • v.43 no.1
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    • pp.154-170
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    • 2022
  • Objectives: The purpose of this study was review the current clinical studies about the effect of Korean traditional medicine treatment for meniscus injury. Methods: Clinical studies on Korean traditional medicine treatment of meniscus injury were searched through 11 online databases. We analyzed the authors, publication year, country, study design, subjects, treatment methods, treatment effects, evaluation tools and adverse events of the selected studies. Results: 23 studies which included 9 randomized controlled trials, 8 case reports, 4 retrospective observational studies, 2 non-randomized controlled trials were selected through the databases. A total of 9 Korean traditional medicine treatments were used, among them, acupuncture treatment was the most used. The most commonly used outcome was effective rate. Conclusions: Through this study, we could confirm that Korean traditional medicine is an effective treatment for meniscus injury. It was suggested that various clinical studies on the effects of Korean traditional medicine for meniscus injury are needed and it is necessary to establish more scientific evidence through studies with a high level of evidence.

Comparative Study between MRI and pain, duration, physical examination in 20 patients with knee joint pain (20례 슬통환자의 통증, 이환기간, 물리적 검사법과 MRI소견과의 비교 고찰)

  • Yang, Myung-bok;Jang, Byung-sun;Lee, Dae-yong;Lee, Seung-hoon;Hwang, Byung-chun;Park, Jung-un;Guk, Ui-suk;Lee, Geon-mok
    • Journal of Acupuncture Research
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    • v.19 no.6
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    • pp.221-233
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    • 2002
  • Background and Purpose : MRI(Magnetic Resonance Imaging) has become one of the most sensitive diagnostic tool no evaluate problems of the knee, because it enables us to identify not only osseous tissue but also soft tissues including muscle, fascia, tendon, ligament, meniscus and fat around the knee joint. Objective : To compare between MRI reading and pain, duration, physical examination in patients with pain of knee joint. Methods : 20 patients with pain of knee joint included in this study. This study researched pain-degree, duration, physical examination with pain of knee joint. Using MRI(Horizon Lx 1.0T-GE), we obtained the results. Results : 1. In the distribution of sex; Female rate was 80.0% and male rate was 20.0%. In the distribution of age, above sixty group was the largest group by each 55.0%. 2. In the distribution of MRI reading; 'Meniscus horm tear' was 70.0%, 'Osteoarthritis' was 55.5%, 'ACL partial tear' was 15.0%, 'Bone bruise at tibia, femur' was 15.0%. 3. Correlation between duration of pain and MRI reading showed that acute and subacute stage related various MRI reading, that chronic stage related 'Osteoarthritis' and 'Meniscus horn tear' by each 69.2%, 92.3%. 4. Correlation between pain and MRI reading showed that severe pain(GVI) related 'ACL partial tear, PCL partial tear' by each 100%, that mild pain(GII) related 'Osteoarthritis, Meniscus horn tear' by each 70.0%, 80.0%. 5. Correlation between physical examination and MRI reading showed that Drawer test related ACL partial tear by each 60.0%, that McMurray test related 'Meniscus horn tear' by each 75.0%. 6. Correlation between effect of treatment and MRI reading showed that 'Osteoarthritis, Meniscus horn tear' related good effect, that ACL partial tear related poor effect. Conclusions : These results suggest that acute and sever pain relate 'ACL partial tear, PCL partial tear', that chronic and mild pain related 'Osteoarthritis, Meniscus horn tear'. So it is responsibility to use MRI as a sensitive diagnostic tool in the knee problems.

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Efficacy of Manual Therapy for Knee Meniscus Injuries: A Systematic Review and Meta-Analysis (반월상 연골 손상에 대한 수기치료의 효과: 체계적 고찰 및 메타분석)

  • Seok-Beom Kang;Han-Byeol Park;Woo-Seok Shon;Young-Jun Kim;Chang-Hoon Woo
    • The Journal of Churna Manual Medicine for Spine and Nerves
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    • v.17 no.2
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    • pp.17-25
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    • 2022
  • Objectives This study aimed to evaluate the efficacy of manual therapy for knee meniscus injuries. Methods We searched seven electronic databases (MEDLINE, Cochrane Library, CAJ, Wanfang, RISS, ScienceON, and OASIS) to collect randomized controlled trials (RCTs) using the keywords "manual therapy OR chuna OR tuina" and "meniscus injury." Results Eleven RCTs were selected based on the inclusion criteria, and all studies were conducted in China. Five studies were meta-analyzed. The systematic review revealed a positive effect of manual therapy for knee meniscus injury. Low risk of selection, attrition, and reporting bias were demonstrated in all studies. Ten studies had a high risk of performance bias. Conclusions The systematic review reported favorable results using manual therapy for knee meniscus injury. However, this study has several limitations because of the high risk of bias. Further clinical studies and reviews with higher levels of evidence are warranted.

Visualization for racing effect and meniscus merging in underfill process (언더필 공정에서 레이싱 효과와 계면 병합에 대한 가시화)

  • Kim, Young Bae;Kim, Sungu;Sung, Jaeyong;Lee, MyeongHo
    • Journal of Advanced Marine Engineering and Technology
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    • v.37 no.4
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    • pp.351-357
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    • 2013
  • In flip chip packaging, underfill process is used to fill epoxy bonder into the gap between a chip and a substrate in order to improve the reliability of electronic devices. Underfill process by capillary motion can give rise to unwanted air void formations since the arrangement of solder bumps affects the interfacial dynamics of flow meniscus. In this paper, the unsteady flows in the capillary underfill process are visualized and then the racing effect and merging of the meniscus are investigated according to the arrangement of solder bumps. The result is shown that at higher bump density, the fluid flow perpendicular to the main direction of flow becomes stronger so that more air voids are formed. This phenomenon is more conspicuous at a staggered bump array than at a rectangular bump array.

Three cases meniscus injury treated with Shinbaro pharmacopuncture therapy

  • Lee, So Jin;Yoon, Tae Kyung;Shin, Soo Ji;Ahn, Sang Min;Lee, Seong Jin;Won, Jeong Yoon;Jang, Yeo Jin
    • Journal of Acupuncture Research
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    • v.34 no.3
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    • pp.109-119
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    • 2017
  • Objectives : The purpose of this report was to show that oriental therapy, specifically Shinbaro pharmacopuncture is effective for improvement of symptoms and and range of motion (ROM) in patients diagnosed with meniscus tears in the knee. Methods : Three patients were treated with herbal medicine, acupuncture, cupping, Shinbaro pharmacopuncture. The efficacies of the treatments in the three cases were assessed and the progress of the three cases were measured Numerical Rating Scale (NRS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), European Quality of Life five dimensions dimensions (EQ-5D), and range of motion (ROM) measurements. Results : After all the treatments, NRS, WOMAC, and EQ-5D decreased. Active and passive ROM of the knee increased. Conclusion : These reports show the effect of Shinbaro pharmacopucture on a meniscus tear. Due to the small number of cases in this study, further case reports are needed.

Effect of Casting Temperature and Speed on Formation of Surface Defect in Al-8Zn-2Mg-2Cu Billets Fabricated by Direct-Chill Casting Process (수직 연속주조 공정으로 제조된 Al-8Zn-2Mg-2Cu 빌렛의 표면 결함 형성에 미치는 주조 온도와 주조 속도의 영향)

  • Lee, Yoon-Ho;Kim, Yong-You;Lee, Sang-Hwa;Kim, Min-Seok;Euh, Kwangjun;Lee, Dong-Geun
    • Journal of Korea Foundry Society
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    • v.41 no.3
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    • pp.241-251
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    • 2021
  • 7000-series aluminum alloys are noted for their superior strength compared with other Al alloys, and their billets are generally fabricated by direct-chill (DC) casting. Surface defects in a DC-cast aluminum billet are mainly related to exudation and the meniscus freezing phenomenon, which are influenced by alloy compositions, casting speed, and casting temperature. 7000-series aluminum alloys have a wide freezing range during solidification, which makes it easy for casting defects to occur. In this study, we investigated surface defect evolution in casting billets of Al-8Zn-2Mg-2Cu alloy fabricated by a DC casting process. The billets showed "wavy" or "dotted" surfaces. The wavy surface was formed by meniscus freezing at a lower casting speed (200 mm/min) and temperature (655 ℃). In the wavy surface, refined dendritic cells were observed in a concave region due to the constitutional supercooling caused by meniscus freezing. Meanwhile, at a higher casting temperature (675 ℃), the dotted surface was formed by pore formation. In the dotted surfaces in the billet formed at a high casting speed (230 mm/min), an exudation layer was formed by the high metallostatic head pressure. The dotted region and the smooth region had a refined dendritic morphology and a columnar morphology at the exudation layer, respectively. This is attributed to the formation of gas pores in the dotted region.