• Title/Summary/Keyword: Conical Tube

Search Result 40, Processing Time 0.026 seconds

A study on the influence of Baekje costumes on Japanese costumes in ancient times (일본 고대 복식에 미친 백제복식의 영향)

  • Kim, Moon-Ja
    • Journal of the Korean Society of Costume
    • /
    • v.62 no.5
    • /
    • pp.96-107
    • /
    • 2012
  • In ancient times, immigrants from Baekje wore various kinds of costumes that provided technological and aesthetic guidance for the Japanese costume, which has been modified and changed in Japan. The clothing and ornaments were strongly influenced directly by costumes of the Baekje period; therefore, many of the Japanese costumes at that time were crafted in the Baekje style. Through the antique records, paintings of tombs and bequests, we were able to find similarities between Baekje and Japan costumes in these categories: clothes, headgear, belt hooks and belt plaques, bronze shoes, and ornaments. (1) Clothes : They wore high-shaped hat and jacket and trousers(;袴) tied the bottom. (2) Headgear : There was a gilt bronze Conical Cap attached to the long tube with terminals in the shape of a hemisphere. (3) Belt hooks and belt plaques: There were horse-shaped belt hooks in mane styles and a checkered pattern on the lower part of the haunch and a belt Plaque shaped like the face of an animal. (4) Gilt bronze shoes: They were made with the style that had two side plates fixed in the instep side and heel-side. (5) Ornaments : They were made with flower-shaped plaques and spiral-shaped decorations. One earring was made with a three-winged pendent that were connected in a chain style and the others were in unique forms that were made by connecting narrow rings and a heart-shaped pendent.

A Study on the Unsteady Aerodynamics of Projectiles in Overtaking Blast Flowfields

  • Muthukumaran, C.K.;Rajesh, G.;Lijo, Vincent;Kim, Heuy-Dong
    • Proceedings of the Korean Society of Propulsion Engineers Conference
    • /
    • 2011.11a
    • /
    • pp.409-414
    • /
    • 2011
  • A projectile that passes through a shock wave experiences drastic changes in the aerodynamic forces. These sudden changes in the forces are attributed to the wave structures produced by the projectile-shock wave interaction. A computational study using moving grid method is performed to analyze the effect of the projectile-shock wave interaction. Cylindrical and conical projectiles have been employed to study such interactions. This sort of unsteady interaction normally takes place in overtaking blast flow fields. It is found that the overall effect of overtaking a blast wave on the unsteady aerodynamic characteristics is hardly affected by the projectile configurations. However, it is noticed that the projectile configurations do affect the unsteady flow structures and hence the drag coefficient for the conical projectile shows considerable variation from that of the cylindrical projectile. The projectile aerodynamic characteristics, when it interacts with the secondary shock wave, are analyzed. It is also observed that the change in the characteristics of the secondary shock wave during the interaction is different for different projectile configurations.

  • PDF

Large Eddy Simulation of a High Reynolds Number Swirling Flow in a Conical Diffuser

  • Duprat, Cedric;Metais, Olivier;Laverne, Thomas
    • International Journal of Fluid Machinery and Systems
    • /
    • v.2 no.4
    • /
    • pp.346-352
    • /
    • 2009
  • The objective of the present work is to improve numerical predictions of unsteady turbulent swirling flows in the draft tubes of hydraulic power plants. We present Large Eddy Simulation (LES) results on a simplified draft tube consisting of a straight conical diffuser. The basis of LES is to solve the large scales of motion, which contain most of the energy, while the small scales are modeled. LES strategy is here preferred to the average equations strategies (RANS models) because it resolves directly the most energetic part of the turbulent flow. LES is now recognized as a powerful tool to simulate real applications in several engineering fields which are more and more frequently found. However, the cost of large-eddy simulations of wall bounded flows is still expensive. Bypass methods are investigated to perform high-Reynolds-number LES at a reasonable cost. In this study, computations at a Reynolds number about 2 $10^5$ are presented. This study presents the result of a new near-wall model for turbulent boundary layer taking into account the streamwise pressure gradient (adverse or favorable). Validations are made based on simple channel flow, without any pressure gradient and on the data base ERCOFTAC. The experiments carried out by Clausen et al. [1] reproduce the essential features of the complex flow and are used to develop and test closure models for such flows.

Self-Excited Noise Generation from Laminar Methane/Air Premixed Flames in Thin Annular JetsPut (환형제트에서의 메탄과 공기의 층류 예혼합 화염에서 발생되는 자발적인 소음에 대한 실험적 연구)

  • Jin, S.H.;Joung, J.H.;Kwon, S.J.;Chung, S.H.
    • 한국연소학회:학술대회논문집
    • /
    • 2003.05a
    • /
    • pp.159-165
    • /
    • 2003
  • Self-excited noise generation from laminar flames in thin annular jets of methane/air premixture has been investigated experimentally. Various flames were observed in this flow configuration, including conical shape flames, ring shape flames, steady crown shape flames, and oscillating crown shape flames. Self-excited noise with the total sound pressure level of about 70dB was generated from the oscillating crown shape flames for the equivalence ratio larger than 0.95. Sound pressure and $CH^{\ast}$ chemiluminescence were measured by using a microphone and a photomultiplier tube. The frequency of generated noise was measured as functions of equivalence ratio and premixture velocity. A frequency doubling phenomena have also been observed. The measured $CH^{\ast}$ chemiluminescence data were analyzed from which the corresponding sound pressure has been calculated. By comparing the data with those of measured ones, the noise source can be attributed to the flame front fluctuation near the edge of the oscillating crown-shape flames. The flame stability regime was influenced sensitively to the supplying air through the inner tube.

  • PDF

Effects of Field Configuration Shielding Area and Changing of Density and Sensitivity on Tube Current and Image Quality in Automatic Exposure Control System (자동노출제어장치의 채광창 차폐정도와 농도, 감도의 변화가 관전류량과 영상품질에 미치는 영향)

  • Jeong, Min-Gyu;Seoung, Youl-Hun
    • Journal of the Korean Society of Radiology
    • /
    • v.14 no.5
    • /
    • pp.635-642
    • /
    • 2020
  • The purpose of this study was to analysis the effects of shielding area of field configuration with changing of sensitivity and density on tube current (milliampere-seconds, mAs) and image quality in automatic exposure control (AEC) system. The equipment used a digital radiography device (Digital Diagnost, Philips, Netherlands), which has a integral type with an X-ray tube and an indirect digital detector. The AEC system conditions were consisted of 9 setting environments, that mode changing of the sensitivity (S200, S400, S800) and the density (+2.5, 0, -2.5). The tube current evaluated automatically exposed mAs under 81 combination conditions crossed by AEC conditions in fixed at 40 kVp. The image quality evaluated the radiographic images that selected valid images by visual assessment the radiographic images of the self-produced conical pyramid phantom and then measured their signal to noise ratio (SNR). As a result, the maximum tube current was 60.0 mAs that automatically exposed conditions were the 100% of shielding area and the sensitivity of S200 and the density of +2.5. The minimum tube current was 0.9 mAs with non-shielding area and the sensitivity of S800 and the density of -2.5. When the shielded area 0% with the sensitivity of S200 and the density of +2.5, the maximum SNR was the highest as 25.2. But when the shielded area 25% with the sensitivity of S800 and the density of -2.5, the minimum SNR was the lowest as 4.7.

Body action impacts the stability of nanomedicine tools in the drug delivery

  • Peng Zou;Wei Zhao;Jinpeng Dong;Yinyin Cao
    • Advances in nano research
    • /
    • v.14 no.3
    • /
    • pp.247-259
    • /
    • 2023
  • Muscle strength and hypertrophy are equivalent when low-intensity resistance exercise is paired with blood flow restriction. This paper deals with the impact of physical exercise in the form of body activities on drug delivery using nanodevices. The body's actions impact the blood flow since the nano drug delivery devices are released into the bloodstream, and physical exercise and all the activities that change the blood flow influence the stability of these nanodevices. The nanodevice for the drug delivery purpose is modeled via nonuniform tube structures based on the high-order beam theory along with the nonlocal strain gradient theory. The nanodevice is made by a central nanomotor as well as two nanoblade in the form of truncated conical nanotubes carrying the nanomedicine. The mathematical simulation of rotating nanodevices is numerically solved, and the effect of various parameters on the stability of nanodevices has been studied in detail after the validation study.

Effect of cross-section geometry on the stability performance of functionally graded cylindrical imperfect composite structures used in stadium construction

  • Ying Yang;Yike Mao
    • Geomechanics and Engineering
    • /
    • v.35 no.2
    • /
    • pp.181-194
    • /
    • 2023
  • The primary objective of this study is to examine the influence of geometry on the stability characteristics of cylindrical microstructures. This investigation entails a stability analysis of a bi-directional functionally graded (BD-FG) cylindrical imperfect concrete beam, focusing on the impact of geometry. Both the first-order shear deformation beam theory and the modified coupled stress theory are employed to explore the buckling and dynamic behaviors of the structure. The cylinder-shaped imperfect beam is constructed using a porosity-dependent functionally graded (FG) concrete material, wherein diverse porosity voids and material distributions are incorporated along the radial axis of the beam. The radius functions are considered in both uniform and nonuniform variations, reflecting their alterations along the length of the beam. The combination of these characteristics leads to the creation of BD-FG configurations. In order to enable the assessment of stability using energy principles, a numerical technique is utilized to formulate the equations for partial derivatives (PDEs).

Multi-objective optimization of tapered tubes for crashworthiness by surrogate methodologies

  • Asgari, Masoud;Babaee, Alireza;Jamshidi, Mohammadamin
    • Steel and Composite Structures
    • /
    • v.27 no.4
    • /
    • pp.427-438
    • /
    • 2018
  • In this paper, the single and multi-objective optimization of thin-walled conical tubes with different types of indentations under axial impact has been investigated using surrogate models called metamodels. The geometry of tapered thin-walled tubes has been studied in order to achieve maximum specific energy absorption (SEA) and minimum peak crushing force (PCF). The height, radius, thickness, tapered angle of the tube, and the radius of indentation have been considered as design variables. Based on the design of experiments (DOE) method, the generated sample points are computed using the explicit finite element code. Different surrogate models including Kriging, Feed Forward Neural Network (FNN), Radial Basis Neural Network (RNN), and Response Surface Modelling (RSM) comprised to evaluate the appropriation of such models. The comparison study between surrogate models and the exploration of indentation shapes have been provided. The obtained results show that the RNN method has the minimum mean squared error (MSE) in training points compared to the other methods. Meanwhile, optimization based on surrogate models with lower values of MSE does not provide optimum results. The RNN method demonstrates a lower crashworthiness performance (with a lower value of 125.7% for SEA and a higher value of 56.8% for PCF) in comparison to RSM with an error order of $10^{-3}$. The SEA values can be increased by 17.6% and PCF values can be decreased by 24.63% by different types of indentation. In a specific geometry, higher SEA and lower PCF require triangular and circular shapes of indentation, respectively.

Antimicrobial Effects of Fermented Coptidis rhizoma and Lonicerae Flos against pathogen (발효 금은화 및 황련의 유해균 억제 효과)

  • Lee, Sin-Ji;Lee, Myeong-Jong;Jung, Ji-Eun;Kim, Ho-Jun;Bose, Shambhunath
    • Journal of Korean Medicine for Obesity Research
    • /
    • v.11 no.1
    • /
    • pp.35-46
    • /
    • 2011
  • Objectives This study was designed to examine antimicrobial effects of Fermented Coptidis rhizoma and Lonicerae Flos against pathogens. Methods Lactobacilli MRS broth was added to 200mL glass bottle containing 20% herb powder(w/v) followed by 30 minute sonication and then shaking at 70 rpm in $70^{\circ}C$ water bath for 3 hours in order to extract fermented herb. Fermented herb extract was autoclaved at $121^{\circ}$ for 15minutes. $2{\times}10^7$ CFU/mL subcultured bacteria was inoculated and cultured for 24 hours and centrifuged at 3000 rpm for 5 minutes. After transferring to 15 mL conical tube, the viable cells were counted. Results and Conclusion Fermented Coptidis rhizoma and Lonicerae Flos both showed antimicrobial effect on pathogens especially when Fermented Coptidis rhizoma was experimented against Staphylococcus aureus.

Characteristics of Phosphate Adsorption using Prepared Magnetic Iron Oxide (MIO) by Co-precipitation Method in Water (공침법에 의해 제조된 Magnetic Iron Oxide (MIO)를 이용한 수중 인 흡착 특성)

  • Lee, Won-Hee;Chung, Jinwook;Kim, Jong-Oh
    • Journal of Korean Society of Water and Wastewater
    • /
    • v.29 no.6
    • /
    • pp.609-615
    • /
    • 2015
  • This study was carried out for characterization of MIO synthesized in our laboratory by co-precipitation method and applied isotherm and kinetic models for adsorption properties. XRD analysis were conducted to find crystal structure of synthesized MIO. Further SEM and XPS analysis was performed before and after phosphate adsorption, and BET analysis for surface characterization. Phosphate stock solution was prepared by KH2PO4 for characterization of phosphate adsorption, and batch experiment was conducted using 50 ml conical tube. Langmuir and Freundlich models were applied based on adsorption equilibrium test of MIO by initial phosphate solution. Pseudo first order and pseudo second order models were applied for interpretation of kinetic model by temperature. Surface area and pore size of MIO were found $89.6m^2/g$ and 16 nm respectively. And, the determination coefficient ($R^2$) value of Langmuir model was 0.9779, which was comparatively higher than that of Freundlich isotherm model 0.9340.