• Title/Summary/Keyword: Experimental formula

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Protective effects of Jinnoe-san, a novel herbal formula in experimental in vitro models of Parkinson's disease (파킨슨병의 세포모델에서 진뇌산(鎭腦散)의 보호효과)

  • Han, Sangtae;Jeong, Ji Cheon
    • Herbal Formula Science
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    • v.25 no.4
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    • pp.537-551
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    • 2017
  • Objectives : Jinnoe-san (JNS) is a novel herbal formula consisting of five oriental medicinal herbs including Polygalae Radix, Prunellae Spica, Perillae Herba, Betulae Cortex, and Lonicerae Flos. In this study, we investigated the effects and molecular mechanism of JNS on Parkinson's disease in vitro model. Methods : The effects of JNS on 1-methyl-4-phenylpyridinium ($MPP^+$)-induced cell death in SH-SY5Y cells were evaluated with a cell viability assay, flow cytometry, and western blots analysis. The effects of JNS on lipopolysaccharide (LPS)-stimulated BV2 microglia were determined with a nitric oxide (NO) assay, enzyme linked immunosorbent assays, and western blots analysis. Result : $MPP^+$-induced cell death in SH-SY5Y cells was significantly reduced by JNS pre-treatment in a dose-dependent manner. JNS inhibited the production of reactive oxygen species, mitochondria dysfunction, and apoptosis induced by $MPP^+$ in SH-SY5Y cells. Furthermore, JNS significantly activated Akt and ERK in SH-SY5Y cells and the ability of JNS to prevent mitochondria dysfunction by $MPP^+$ was antagonized by pre-treatment of LY294002 and PD98059, an Akt and ERK inhibitor, respectively. In addition, JNS inhibited LPS-induced NO and $PGE_2$ production as well as iNOS expression and secretion of TNF-${\alpha}$, pro-inflammatory cytokines without affecting the cell viability. JNS also suppressed LPS-induced ERK activation. Conclusions : These results demonstrate that JNS has a protective effect on the dopaminergic neurons against $MPP^+$-induced neurotoxicity and anti-inflammatory effect on the LPS-stimulated microglia. These findings provide evidences for JNS to be considered as a new prescription for treating Parkinson's disease.

A Simple Formula for Ultimate Strength Prediction of Hull Girders (선각거더의 최종강도 간이계산식)

  • J.K. Paik;A.E. Mansour
    • Journal of the Society of Naval Architects of Korea
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    • v.32 no.3
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    • pp.83-97
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    • 1995
  • The aim of this study is to derive a simple formula for predicting ultimate strength of hull girders under vertical bending moment. The existing formulas have been reviewed and classified into analytical approach, empirical approach and linear approximate approach. It is known that the ship hull will reach the ultimate limit state if both collapse of the compression flange and yielding of the tension flange occur. Side shells in the vicinity of the compression and tension flanges will often fail also, but the material around the final neutral axis will remain in the elastic state. Based on this observation, a credible distribution of longitudinal stresses around the hull section at the overall collapse state is assumed, and an explicit analytical formula is derived. The accuracy of the formula has been verified by a comparison of the experimental and the numerical results.

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Formula for Equivalent Impulsive Force to Predict Vibrational Response of High-frequency Staircases (고진동수 계단의 진동응답 산정을 위한 등가임펄스 산정식 제안)

  • Kim, Na Eun;Lee, Cheol Ho;Kim, Sung Yong
    • Journal of Korean Society of Steel Construction
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    • v.27 no.2
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    • pp.181-193
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    • 2015
  • High-frequency staircases are widely used nowadays to meet aesthetics and functionality needed in modern architecture. Unfortunately, no design guide is available in domestic practice to predict response or evaluate the vibration performance of high-frequency staircases. SCI-P354 published by the Steel Construction Institute of UK provides the formula for effective impulsive force. However, this formula was shown to overestimate the response of high-frequency staircases excited by fast ascending and descending over 2.2Hz pace frequency because it was developed based on the walking test in a slow pace frequency. This study proposes a semi-analytical formula to predict the response of stiff staircases based on analytical and experimental studies of response acceleration for various walking frequencies covering 1.4~4.5Hz.

Atom Number Densities for Uranyl Nitrate Solution (질산우라늄용액의 구성원소별 원자수밀도)

  • Seung Gy Ro;Duck Kee Min;Jung-Kyoon Chon
    • Nuclear Engineering and Technology
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    • v.14 no.3
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    • pp.103-109
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    • 1982
  • An empirical formula for determining water content as functions of uranium concentration and nitric acid normalities in uranyl nitrate solutions has been derived from a least-squares analysis of experimental data, i.e., uranium concentration, nitric acid normalities and solution densities for a large number of UO$_2$(NO$_3$)$_2$ solutions. The formula derived is Q=1-0.3628C-0.0327H$^{+}$ where Q, C, and H$^{+}$ stand for water content (g/cc), uranium concentration (g/cc), ana nitric acid normality, respectively. Atom number densities and nuclear criticality for hypothetical uranyl nitrate solutions have been calculated by using the empirical formula, ana compared with the results obtained on the basis of uranium concentration, nitric acid normality, and solution density. The empirical formula derived in this study seems to be useful in uranium concentrations ranging from 0.295g/cc down to 0.004g/cc and nitric acid normality from 5.06 to 1.00..00.

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Development of a New Munk-type Breaker Height Formula Using Machine Learning (머신러닝을 이용한 새로운 Munk-type 쇄파파고 예측식의 제안)

  • Choi, Byung-Jong;Nam, Hyung-Sik;Lee, Kwang-Ho
    • Journal of Navigation and Port Research
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    • v.45 no.3
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    • pp.165-172
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    • 2021
  • Breaking wave is one of the important design factors in the design of coastal and port structures as they are directly related to various physical phenomena occurring on the coast, such as onshore currents, sediment transport, shock wave pressure, and energy dissipation. Due to the inherent complexity of the breaking wave, many empirical formulas have been proposed to predict breaker indices such as wave breaking height and breaking depth using hydraulic models. However, the existing empirical equations for breaker indices mainly were proposed via statistical analysis of experimental data under the assumption of a specific equation. In this study, a new Munk-type empirical equation was proposed to predict the height of breaking waves based on a representative linear supervised machine learning technique with high predictive performance in various research fields related to regression or classification challenges. Although the newly proposed breaker height formula was a simple polynomial equation, its predictive performance was comparable to that of the currently available empirical formula.

Horizontal Wave Pressures on the Crown Wall of Rubble Mound Breakwater Under a Non-Breaking Condition: Effect of the Armour Crest Width (비쇄파조건에서 경사식방파제의 상치콘크리트에 작용하는 수평파압: 피복재 어깨폭 영향)

  • Lee, Jong-In;Lim, Ho Seok;Cho, Ji Hoon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.42 no.4
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    • pp.469-480
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    • 2022
  • To design the crown wall of rubble-mound breakwaters, the horizontal wave load should be available, but determining this load remains difficult. Lee et al. proposed modification factors for Goda's formula for the horizontal wave pressures on acrown wall. The empirical formula by Lee et al. was based on a two-dimensional model test with a relatively narrow armour crest width in front of the crown wall. In this study, a series of experiments at the same facility were conducted on the horizontal wave pressures on the crown wall of a rubble-mound breakwater with a wide armour crest width. As a result, the pressures of the unprotected part of the crown wall were nearly identical to the narrow crest width. However, the pressures of the protected part tended to decrease with a change in the armour crest width. From the experimental results, the horizontal pressure modification factors of Goda's formula including the armour crest width effect are suggested here and are likely applicable to practical designs of the crown walls of rubble-mound breakwaters covered with tetrapods.

A Experimental Study on Fatigue Behavior of Joints between RC and RSFC subjected to shear (강섬유 보강 철근콘크리트 전단이음부의 피로거동에 대한 실험적 연구)

  • 강보순
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2000.10a
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    • pp.389-396
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    • 2000
  • Fatigue behavior of shear joints between combined reinforced concrete(RC) and reinforced steel fiber concrete(RSFC) specimens has been experimentally investigated. Experimental parameters used are the amount of steel fiber and the type of shear joint. 6 specimens have been tested under static load, and 8 specimens have been subjected to the fatigue load in a range of 50% and 5 % of the ultimate static load. The purpose of this research is to propose an empirical formula for fatigue shear behavior of combined RC and RSFC structures on the basic of experimental result. It can be observed from experimental result that addition of steel fibers to concrete specimen increases the static ultimate load by approximately 25%, enhances the fatigue behavior, and also reduces vertical and lateral displacements at the shear joint for a given load cycle after the occurrence of first crack.

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Experimental Analysis of Stress Intensity Factors by Combination With Moire Method and Slab Analogy (모아레法 과 스라브相似 의 複合 에 의한 應力擴大係數 의 實驗的 解析法 -有限板크랙 의 $K_I$$K_II$-)

  • 최선호;권재도;김종주;채영석
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.6 no.4
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    • pp.315-322
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    • 1982
  • The slab analogy method was introduced in the 1920's for the first time as a new experimental stress analysis method. Notwithstanding its theoretical propriety, this method has not been recognized as efficient one because of its difficulty in practical measurement of the slab curvature. In this paper, aiming at experimental determination of two-dimensional stress intensity factors(S. I. F) of arbitrarily shaped cracks which had been regarded as almost impossible by conventional method, the slab analogy was reevaluated. Measuring of slab curvature was replaced by three simple measuring factors to overcome vital slab-analogy's shortcoming by joint use of the shadow-moire method. A determination formula was also derived from the theory of fracture mechanics. By this newly exploited method, it was found that the slab analogy still has its great advantage in determination of S.I.F. of arbitrarily shaped cracks with considerable accuracy compared with existent experimental methods.

The Added Mass and Damping for the Axial Rigid Body Motion of a Marine Propeller Rotating in a Uniform Flow (선박용 프로펠러의 종방향 강체운동에 대한 부가질량)

  • Kim, Young-Joong;Lee, Hyun-Yup;Lee, Chang-Sup
    • Journal of the Society of Naval Architects of Korea
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    • v.45 no.3
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    • pp.309-314
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    • 2008
  • An experimental method to estimate the added mass of a marine propeller has been developed for the axial rigid body motion in still water, and the experiments have been carried out. The experimental result has been compared to the theoretical result by PRODAS based on the unsteady lifting surface theory. The experimental method developed in this research and the theoretical method by PRODAS have been validated by confirming good agreements between the experimental results and the theoretical ones. Also the comparison to the results by empirical formula has been made and discussed.

An Experimental Study on the Shear Wave Velocity Improvement of Ground by Ground Improvement (지반개량을 통한 원지반의 전단파속도 향상에 대한 실험적 연구)

  • Jeong, Chan-Yu;Mun, Jae-Sung;Jo, Myoung-Su;Kang, Ho-deok;Yang, Hee-Jeong
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.23 no.7
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    • pp.33-39
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    • 2019
  • In this study, an experimental study was carried out with variables of the shape of the ground soil-binder in order to find out whether the shear wave velocity and the ground grade were improved by the ground improvement. In this study, the shear wave velocity was measured using the crosshole method with variables of the shape of the ground soil-binder. In addition, the prediction formula of the shear wave velocity for suitability of N-Values for the domestic soil conditions are proposed using the result value of this study and the existing results of shear wave velocity. As a result, the shear wave velocity of the ground has increased. In addition, the prediction formula proposed in this study reasonably issued the existing experimental results regardless of the stratum conditions.