Solidification Front Velocity of Ternary Titanium-Aluminides

1995 ◽  
Vol 398 ◽  
Author(s):  
M. Wettlaufer ◽  
J. Laakmann
Keyword(s):  
Experimental Data ◽  
Temperature Measurement ◽  
Solidification Front ◽  
High Speed ◽  
Titanium Aluminides ◽  
Front Velocity ◽  
Experimental Results ◽  
Video System ◽  
High Speed Video ◽  
Bulk Undercooling

ABSTRACTTernary titanium-aluminides with compositions of Ti51Al47Fe2, Ti51A147Cr2 and Ti51Al47Mn2 were investigated with respect to the correlation of their solidification front velocity v and bulk undercooling ΔT. The observation of the solidification front during the recalescence event has been realized using a high speed video system capable of recording up to 12,000 pictures per second. The temperature measurement was carried out by pyrometry, avoiding contact with the sample. The comparison of the experimental data with the LKT-theory (Lipton, Kurz, Trivedi; [1]) refers to a primary (hcp) β-Ti solidification for undercoolings below ΔT≈ 130 K and primary (bcc) α-Ti solidification for ΔT≥ 130 K. For undercoolings ≥ 150 K the theory differs greatly from the experimental results.The maximum undercoolings achieved were 268 K (Ti51Al47Fe2), 285 K (Ti51Al47Cr2) and 280 K (Ti51Al47Mn2), corresponding to a solidification front velocity v ≈ 9-10 m/s for all alloys.

scholarly journals Kinematic parameters of goats walking on different slopes and biomimetic walking mechanisms

2017 ◽  
Author(s):  
Fu Zhang ◽  
Yafei Wang ◽  
Wei Wang ◽  
Keyword(s):  
Experimental Data ◽  
Theoretical Basis ◽  
High Speed ◽  
Rate Of Change ◽  
Kinematic Parameters ◽  
High Speed Video ◽  
Experimental Image ◽  
Displacement Speed ◽  
Walking Mechanism ◽  
Uphill Walking

A comparative analysis of the kinematic parameters of a goat on different slopes was conducted to study the kinematic parameters of goats on different slopes with walking mechanics. The uphill walking processes on different slopes (0°, 5°, 10°, 15°, 20°, 25° and 30°) were recorded by a high speed video system (VRI Phantom M110). The experimental image results were processed and analyzed using PCC and MATLAB software. The kinematic parameters were obtained from the goat walking on different slopes; these parameters are the changes of centroid with displacement, speed with time, and acceleration with time. As the gradient in the uphill process increases, the range of centroid fluctuation ranges from 0.079 to 0.59 and the rate of change ranges from 0.4 to 2.2 m/s, while the acceleration of the goat slope decreases. The present research can provide theoretical basis and experimental data for the design of a biomimetic agricultural slope walking mechanism.

High Speed Milling Vibration Surveillance with Optimal Spindle Speed Based on Optimal Speeds Map

2013 ◽  
Vol 597 ◽  
pp. 125-130 ◽  
Author(s):  
Krzysztof J. Kalinski ◽  
Marek A. Galewski ◽  
Michał R. Mazur
Keyword(s):  
Experimental Data ◽  
Computational Model ◽  
High Speed ◽  
End Milling ◽  
The Self ◽  
Experimental Results ◽  
Modal Parameters ◽  
Chatter Vibration ◽  
High Speed Milling ◽  
Milling Vibration

The paper presents the method of the surveillance of the self-excited chatter vibration. At first, the workpiece modal parameters are estimated based on experimental data which leads to verification of computational model. Then, for selected surface points optimal spindle speeds are calculated. By considering sufficient amount of points it is possible to build a map of optimal spindle speeds. Experimental results show that this map may be used effectively for eliminating chatter in case of the process of ball end milling of a curved flexible detail.

Evaluation of botulinum toxin effects in hemifacial spasm patients: correlation between clinical rating scales and high-speed video system measurements

2020 ◽  
Vol 127 (7) ◽  
pp. 1041-1046
Author(s):  
Tammy H. Osaki ◽  
Midori H. Osaki ◽  
Denny M. Garcia ◽  
Teissy Osaki ◽  
Lilian Ohkawara ◽  
...  
Keyword(s):  
Botulinum Toxin ◽  
Hemifacial Spasm ◽  
High Speed ◽  
Rating Scales ◽  
Video System ◽  
High Speed Video ◽  
Clinical Rating

Experiments and Modeling of Failure and Fragmentation of Alumina Cylinders under Uniaxial Compression

2012 ◽  
Vol 13 (1) ◽  
Author(s):  
Yong-Gang Wang ◽  
Jian-Dong Hu ◽  
Feng-Hua Zhou
Keyword(s):  
Experimental Data ◽  
Compressive Strength ◽  
Uniaxial Compression ◽  
High Speed ◽  
Cylindrical Specimen ◽  
Specimen Size ◽  
Fragmentation Model ◽  
High Speed Video ◽  
Axial Splitting

AbstractQuasistatic compressive strength of alumina cylinders was measured using specimen of two sizes. The strength of the material was dependent on the specimen size. High speed video photography showed that the failure of the cylindrical specimen started from axial splitting, and after failure the specimen fragmentized into small pieces. A fragmentation model was proposed for estimating the average sizes of the fragments. The calculated fragment sizes agreed reasonably well with the experimental data. By using Ls-Dyna software, the failure of cylindrical specimen containing pre-existing crack-like flaws had been simulated.

Design and Fabrication of MEMS-Based Solid Propellant Microthrusters Array

2014 ◽  
Vol 490-491 ◽  
pp. 1042-1046 ◽  
Author(s):  
Cheng Bo Ru ◽  
Ying Hua Ye ◽  
Cheng Ling Wang ◽  
Peng Zhu ◽  
Rui Qi Shen ◽  
...  
Keyword(s):  
Solid Propellant ◽  
High Speed ◽  
Adhesive Bonding ◽  
Power Source ◽  
Test Stand ◽  
Propulsion System ◽  
Constant Voltage ◽  
Initial Test ◽  
Video System ◽  
High Speed Video

A solid propellant microthruster array consists of three parts (five layers) was designed to form propulsion system of nanosatellite. The layers of the array were fabricated by different MEMS technique respectively. Then the array was assembled by adhesive bonding (H70E thermal epoxy). An initial test was operated with the ignition test stand composed of high speed video system, electronic power source, and oscilloscope. A constant voltage was applied to the igniters through two probes contact with the pad of ignition circuitry. The test indicates that the microthruster array can be ignited under 15V.

New Approach to Assess in Vivo Rearfoot Control of Court Footwear during Side-Stepping Moves

1997 ◽  
Vol 13 (2) ◽  
pp. 197-204 ◽  
Author(s):  
Mario A. Lafortune
Keyword(s):  
High Speed ◽  
Pressure Sensors ◽  
Experimental Results ◽  
Lateral Side ◽  
New Approach ◽  
High Speed Video ◽  
High Discrimination

Miniature pressure sensors and high-speed video were used to assess the lateral support and stability of court footwear during in vivo performance of lateral side-stepping moves. Two distinct types of court footwear construction were evaluated and were found to differ by approximately 100% and 200% in lateral support and stability, respectively. The heel control index that combined both parameters revealed differences exceeding 425%. A comparison of shoes that differed only in one construction feature produced similar trends. These overall results suggest that the combined high-speed video/pressure approach allows high discrimination of footwear rearfoot control properties during in vivo simulated playing conditions. The specific experimental results suggest that footwear designed for court sports exhibits considerable differences in foot support and stability. Furthermore, it was found that some construction features could improve these properties in court footwear.

scholarly journals On the mechanism of droplet rolling and spinning in inclined hydrophobic plates in wedge with different wetting states

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Bekir Sami Yilbas ◽  
Mubarak Yakubu ◽  
Abba Abdulhamid Abubakar ◽  
Hussain Al-Qahtani ◽  
Ahmet Sahin ◽  
...  
Keyword(s):  
Experimental Data ◽  
High Speed ◽  
Recording System ◽  
Experimental Results ◽  
Phase Contact ◽  
Droplet Motion ◽  
3D Space ◽  
Three Phase ◽  
Tangential Momentum ◽  
Recorded Data

AbstractA water droplet rolling and spinning in an inclined hydrophobic wedge with different wetting states of wedge plates is examined pertinent to self-cleaning applications. The droplet motion in the hydrophobic wedge is simulated in 3D space incorporating the experimental data. A high-speed recording system is used to store the motion of droplets in 3D space and a tracker program is utilized to quantify the recorded data in terms of droplet translational, rotational, spinning, and slipping velocities. The predictions of flow velocity in the droplet fluid are compared with those of experimental results. The findings revealed that velocity predictions agree with those of the experimental results. Tangential momentum generated, via droplet adhesion along the three-phase contact line on the hydrophobic plate surfaces, creates the spinning motion on the rolling droplet in the wedge. The flow field generated in the droplet fluid is considerably influenced by the shear rate created at the interface between the droplet fluid and hydrophobic plate surfaces. Besides, droplet wobbling under the influence of gravity contributes to the flow inside the rolling and spinning droplet. The parallel-sided droplet path is resulted for droplet emerging from the wedge over the dusty surface.

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