• Title/Summary/Keyword: Magnus Effect

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Anti-nociceptive, Anti-inflammatory, Mental Effects of Essential Oil from Thymus magnus (섬백리향 정유의 진통, 항염증, 정신적인 작용)

  • Kim, Sun-Min;Suk, Kui-Duk
    • YAKHAK HOEJI
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    • v.51 no.6
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    • pp.508-516
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    • 2007
  • Thymus magnus is an endemic (Ulleung Island) species in Korea. This plant is used as diaphoretics and carminatives in traditional medicine. In the literature, few scientific assays were realized on this species, such as antibiotic (Streptococcus pneumoniae, Staphylococcus aureus, Salmonella enteritidis, and S. typhimurium) and antifungal activities. In order to clarify whether essential oil of T. magnus have pharmacological effects, anti-inflammatory, sedative, anti-depressant, analgesic, and sleep-prolonged effects were investigated using animal models. From this study, the following conclusions were attained; 1) Essential oil of T. magnus did not show any acute toxicity on mice when orally administered at the dose of 2-3 g/kg body weight. 2) Essential oil of T. magnus possessed strong anti-inflammatory activity, similar to that of a positive control prednisolone. 3) Essential oil of T. magnus had excellent analgesic activity, comparable to that of aspirin. 4) The essential oil of T. magnus possessed strong sleep-prolonged effect on pentobarbital induced-sleep test in mice model. 5) In the hot plate test, the essential oil of T. magnus had moderate effect. 6) And the essential oil of T. magnus had no significant effects in forced-swimming test and open-field test.

Development of Magnus Effect Measurement Technique for Spinning Projectile (회전 발사체용 마그너스 효과 특정기법의 개발)

  • Oh, Se-Yoon;Kim, Sung-Cheol;Lee, Do-Kwan;Choi, Joon-Ho;Ahn, Seung-Ki
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.35 no.1
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    • pp.79-86
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    • 2007
  • The Magnus effect measurement apparatus was designed and built for spinning wind tunnel model which would simulate the rotation of projectiles. Prior to the high speed test, the ground functional test and the low speed test were carried out in the Agency for Defense Development's Low Speed Wind Tunnel(ADD-LSWT) at spin rates from about 6,000 to 10,000 rpm. Magnus force and moment were measured on the spinning projectile model at velocity of 100 m/s. It was shown that the Magnus force and moment were linear function of spin parameter. The test results were compared with Magnus test run on the same configuration in the Arnold Engineering Development Center's Propulsion Tunnel 4T(AEDC-4T).

Evaluation of The Dispersion Uniformity of Footprint of The Magnus Rotor Type Dispersive Submunition (Magnus Rotor형 분산자탄 탄착군의 분산 균일도 평가)

  • Hyeongyu Sakong
    • Journal of the Korea Institute of Military Science and Technology
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    • v.27 no.2
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    • pp.230-237
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    • 2024
  • Dispersion munitions are often equipped with dispersive submunitions used to scatter bombs over a wide area, and one of the types of dispersive submunitions is the Magnus rotor, commonly referred to as a self-rotating flying body. The Magnus rotor is designed to be dispered over a wide area by utilizing the principle of the Magnus effect through self-rotation, and has various trajectories depending on the initial conditions from the mother dispersion munition. In this paper, an index to evaluate the dispersion uniformity of footprint of the dispersive submunition is presented and the dispersion uniformity according to various initial release conditions is evaluated, and it is getting larger with high incidence angle and get max value at certain initial angular velocity.

Experimental Study on the Effects of Surface Shape and Roughness on the Magnus Effect of Rotor Sails (로터 세일의 표면 형상과 조도 변화에 따른 마그누스 효과에 관한 실험연구)

  • Young-Jin Kim;Jae-Yeun Hwang;Byoung-Kwon Ahn
    • Journal of the Society of Naval Architects of Korea
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    • v.60 no.5
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    • pp.351-357
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    • 2023
  • In this study, we devised methods to enhance the efficiency of rotor sails which have been applied as one of the energy saving devices of ships. The idea of the study originated from the notion that installing protrusions or increasing the surface roughness on the smooth surface of the rotor sail could delay the separation of the incoming wind flow and consequently increase the lift force. Five cylinder models were considered and tested in an open-type wind tunnel at Chungnam National University. A smooth surface cylinder exhibits the highest lift-to-drag ratio at a specific Reynolds number, and as the Reynolds number increases this value decreases sharply. The variation in this typical Magnus force can be significantly improved by altering the surface shape and roughness of the rotor sail. It has been observed that increasing the surface roughness improves the lift characteristics, resulting in increased efficiency. Furthermore, it revealed that the reverse Magnus effect which may occur during actual operation in the low spin ratio region can be significantly enhanced.

The Effect of Electroacupuncture on Pain Threshold and 5.Hydroxytryptamine Synthesis Induced by Nociception in the Raphe Magnus Nucleus of Dog Brain Stem (개의 발에 염증 유발 후 전침이 통증역치 및 뇌줄기 큰솔기핵의 5-Hydroxytryptamine 합성에 미치는 효과)

  • Cho, Mi-Suk
    • The Journal of Korean Physical Therapy
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    • v.23 no.1
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    • pp.59-66
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    • 2011
  • Purpose: The purpose of this study was to investigate the effect of electroacupuncture on pain threshold and 5-HT synthesis in raphe magnus nucleus of dog brain stem following nociception induced by 1% carageenan. Method: Twenty male dogs were randomly divided into two groups, a control group and an electroacupuncture group with the following parameters: ST36, LI11 and SP9 with 120Hz and 0.5mA. The dogs were sacrificed at 30, 60, 90, 120, 150 and 180 min after nociception using 1% carageenan injection into the plantar side of the dog's left leg. The pain threshold was recorded by an Analgesia-meter. After making brain slice sections, the tissues were immunostained with 5-HT antisera (1:2,500). Results: The pain threshold for the electroacupuncture group was higher than for the control group. The number of 5-HT immunoreactive neurons in the electroacupuncture group was greater than that of the control group. Differences between the two groups regarding the number of 5-HT immunoreactive neurons at 30 min and 60 min (p<0.05), at 120 min and 150 min (p<0.01), and at 8 days (p<0.05) were significant. Conclusion: The increases in pain threshold and number of 5-HT immunoreactive neurons in the raphe magnus nucleus of dog brain stem showed that electroacupuncture can attenuate pain transduction through the descending tract.

Quantitative Analysis of Initial Dispersion Condition Effects on Randomness of Magnus Rotor Bomblet (Magnus Rotor 자탄의 초기 방출조건이 분산도에 미치는 영향에 대한 정량적 분석)

  • Bai, Ikhyun
    • Journal of the Korea Society for Simulation
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    • v.28 no.3
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    • pp.83-89
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    • 2019
  • This research describes quantitative effects of initial dispersion conditions upon the dispersion randomness of Magnus rotor bomblets. Ratios of the missile spin rate to the missile velocity, a, flight path angles, ${\gamma}$ and altitudes, h, were changed to investigate their effects on dispersion randomness. Dispersion was analyzed through calculation of 6 degree of freedom motion equation with aerodynamic coefficients from wind tunnel experiments. In order to analyze the randomness, regression analysis is adopted to calculate the coefficient of determination. The optimized ratio of the missile spin rate to the missile velocity and flight path angle were obtained and the dispersion altitudes had more effect on the dispersion diameter and had less effect on dispersion than other parameters.

An Experimental Study on Magnus Characteristics of a Spinning Projectile at High Speed Region (회전발사체 마그너스 특성에 관한 고속 유동장 실험연구)

  • Oh, Se-Yoon;Lee, Do-Kwan;Kim, Sung-Cheol;Kim, Sang-Ho;Ahn, Seung-Ki
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.39 no.5
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    • pp.385-390
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    • 2011
  • The purpose of this research is to determine the dynamic Magnus effect data of a spinning projectile in wind-tunnel testing. In the present work, the high-speed wind-tunnel tests for the Magnus effect measurements were conducted on a 155-mm spin-stabilized projectile model in the Agency for Defense Development's Tri-Sonic Wind Tunnel at spin rates about 12,000 rpm. The test Mach numbers ranged from 0.7 to 2.0, and the angles of attack ranged from -4 to +10 deg. The validity of the wind-tunnel measurement techniques was evaluated by comparing them with the previous test results on the same configuration. The experimental results show that fair to good agreement is obtained with resonable accuracy.

In vivo Anti-fungal Activity of the Essential Oil Fraction from Thymus Species and in vitro Synergism with Clotrimazole

  • Kim, Ji-Hyun;Shin, Seung-Won
    • Natural Product Sciences
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    • v.13 no.3
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    • pp.258-262
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    • 2007
  • The antifungal activity of the essential oil fraction from Thymus magus, and its major component thymol, against Candida albicans was investigated in vitro and in vivo. The combined effects of the oils and clotrimazole, a commonly used antifungal drug for treatment of external candidiasis, were evaluated in this study. In experimental vaginal candidiasis the essential oil fraction of T. magnus resulted in relatively milder inhibition of fungal growth following the inoculation of test mice compared to clotrimazole. However, new fungal growth was not detected up to 12 days after cessation of treatment. In contrast, in a similar experiment using clotrimazole, C. albicans was detected in the $12^{th}$ day post-treatment with the sample. This result indicates that T. magnus oil could be a promising drug to control vaginal candidiasis. In checkerboard titer tests, the combination of clotrimazole with the essential oil fraction of T. magus or T. quinquecostatus resulted in significant synergism, with FIC indices between 0.14 and 0.27 against C. albicans, while clotrimazole combined with thymol, the major component of these oils, produced only an additive effect, with FIC indices ranging between 0.50 and 1.00. Thus, the prominent synergistic effects of clotrimazole combined with T. magus essential oil indicate that these compounds may be an effective treatment for C. albicans infections.

Selection of Native Ground Cover Plants for Sod Culture in an Organic Apple Orchard (유기농 사과과원에서 초생재배를 위한 자생지피식물의 선발)

  • Heo, Jae-Yun;Park, Young-Sik;Um, Nam-Yong;Park, Sung-Min
    • Korean Journal of Plant Resources
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    • v.28 no.5
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    • pp.641-647
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    • 2015
  • This study was conducted to select native ground cover plants for sod culture in an organic apple orchard by estimating the effect of three native ground cover plants, Glechoma hederacea, Thymus magnus, and Ixeris stolonifera, on the soil coverage, time-periodic weed occurrence, fruit characteristics, and soil chemical properties. The plant height of G. hederace, T. magnus and I. stolonifera were 15.0 ㎝, 13.4 ㎝ and 7.2 ㎝, respectively. The dry weight of G. hederace, T. magnus and I. stolonifera were 463 ㎏/10a, 247 ㎏/10a, and 255 ㎏/10a, respectively. The plant height and dry weight of G. hederacea were higher than in the other species. T. magnus and I. stolonifera having relatively lower soil cover rate during their life cycle produced a lot of weeds in the orchard as compared with the control. In contrast, G. hederacea showed 100 percentage of ground cover in the first year, and maintained high percentage of ground cover in the growing season of ‘Tsugaru’ apple for another 2 years. When the soil was covered with G. hederacea in the orchard for 3 years, the amount of weed was only 114 ㎏/10a and number of weeding was also reduced about 33% compared with control as well as the other species. There were no differences in the tree growth and fruit characteristics between the native ground cover plants and the control; however, positive effects of native ground cover plants on soil chemical properties were found. In G. hederacea, available P2O4content in soils remarkably increased and was a significant difference among native species. In addition, cation (Ca, Mg and K) content in soils increased by 39% in Ca, 6% in Mg, and 11% in K at G. hederacea compared with control. These results suggest that G. hederacea could be advantageous in terms of reducing the amount of herbicide applied and the labor required for weed control, and controlling soil chemical properties; therefore, it is a good candidate for sod culture in an organic apple orchard.

Preparation and Characteristics of Anti-Fungal Paper with Natural Extractives (천연 추출물을 이용한 항균지의 제조 및 특성)

  • Kim, Kang-Jae;Jung, Jin-Dong;Ahn, Eun-Byeoul;Eom, Tae-Jin
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.47 no.1
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    • pp.45-51
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    • 2015
  • The anti-fungal activity of plant extractives was investigated and the lacquer extractives were selected. The lacquer extractives were coated on anti-fungal paper and confirmed its effect. Water repellency, tensile index and brightness of anti-fungal paper treated with natural extractives were similar to commercial pesticide-treated paper. The incidence of Fusicaladium leuieri MAGNUS of commercial pesticide-treated paper and anti-fungal paper treated with lacquer were similar but, the incidence of Botryosphaeria dothidea (Moug.) Ces & De Not and Gloeodes pomigena of those were increased 10-60 % than commercial pesticide-treated paper.