Demonstration and Characterization of a Multi-Stage Silicon Microturbine

2005 ◽  
Author(s):  
Changgu Lee ◽  
Luc G. Fre´chette
Keyword(s):  
Layer Structure ◽  
Experimental Testing ◽  
Maximum Speed ◽  
Glass Wafer ◽  
Multi Stage ◽  
Calculation Results ◽  
Etched Silicon ◽  
Radial Outflow ◽  
Isentropic Efficiency

This paper presents the experimental testing and characterization of a microscale radial outflow turbine with four concentric stages. The device is a five layer structure composed of shallow and deep reactive ion etched silicon wafers and an ultrasonically drilled Pyrex glass wafer that are assembled using anodic and fusion bonding techniques. They enclose a 4mm diameter rotor that was spun up to 330,000 rpm and produced roughly 0.1W of mechanical power from each stage totaling 0.38W with 0.75 atm differential pressure across the microturbine. Modeling of the turbine based on a mean line analysis with loss correlations extracted from CFD suggests a turbine isentropic efficiency of 35% and Re=266 at the maximum speed. The pressure distribution across the blades rows was measured and showed close agreement with the calculation results. Using the model, the microturbine is predicted to produce 3.2 watts with an isentropic efficiency of 63% at a rotor speed of 1.1 million rpm.

Characterization of multi- and single-layer structure SAW sensor

2006 ◽  
Author(s):  
S. Ahmadi ◽  
F. Hassani ◽  
C. Korman ◽  
M. Rahaman ◽  
M. Zaghloul
Keyword(s):  
Layer Structure ◽  
Single Layer ◽  
Saw Sensor

scholarly journals Process-Induced Distortions Characterization of MBWK Fabric Reinforced Composite Helmet Shell

Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 2983
Author(s):  
He Xiang ◽  
Yaming Jiang ◽  
Yexiong Qi ◽  
Jialu Li
Keyword(s):  
Thin Shell ◽  
High Performance ◽  
Laser Scanning ◽  
Textile Composites ◽  
Reinforced Composite ◽  
Measurement Results ◽  
Calculation Results ◽  
High Performance Composite ◽  
Working Procedure

In order to characterize the process-induced distortions of 3D thin shell composites with complex shape, the multilayered biaxial weft knitted (MBWK) fabric reinforced high-performance composite helmet was selected as the research object, and the 3D laser scanning machine was used to scan the helmet surface, then the 3D scanning data was compared with the CAD model to evaluate the deformation. The results and discussion indicated that the conventional method was workable, but the speed of convergence was slow and the calculation results were easy to drop into local optimization. According to detailed analysis, a measurement method focusing on the principle of “Feature Distance” was developed. The measurement results shown that this method can not only give accurate results, but also reduce working procedure and greatly save the computing resources, which is proved to be a feasible approach for the deformation measurement foundation of 3D thin shell textile composites.

An Elaborate Data Set for Mechanical Characterization of the Foot

2008 ◽  
Author(s):  
Pavana Sirimamilla ◽  
Ahmet Erdemir ◽  
Antonie J. van den Bogert ◽  
Jason P. Halloran
Keyword(s):  
Mechanical Response ◽  
Experimental Testing ◽  
Experimental Tests ◽  
Shear Loading ◽  
Data Set ◽  
Material Response ◽  
Heel Pad ◽  
Biaxial Tests

Experimental testing of cadaver specimens is a useful means to quantify structural and material response of tissue and passive joint properties against applied loading[1,4]. Very often, specific material response (i.e., stress-strain behavior of a ligament or plantar tissue) has been the goal of experimental testing and is accomplished with uniaxial and/or biaxial tests of prepared tissue specimens with uniform geometries[2,5]. Material properties can then be calculated directly and if testing data involves individual sets of multiple loading modes (e.g. compression only, shear only, volumetric) an accurate representation of the global response of the specimen may be possible. In foot biomechanics, however, it is practically impossible to perform isolated mechanical testing in this manner. The structural response, therefore the stiffness characteristics, of the foot have been quantified, usually using a dominant loading mode: e.g., whole foot compression [6], heel pad indentation [3]. This approach ignores the complexity of most in vivo loading conditions, in which whole foot deformation involves interactions between compression, shear (e.g. heel pad) and tension (e.g. ligaments). Therefore, the purpose of this study was to quantify the mechanical response of a cadaver foot specimen subjected to compression and anterior-posterior (AP) shear loading of isolated heel and forefoot regions as well as whole foot compression. Results from the experimental tests represent a novel methodology to quantify a complete structural biomechanical response. Combined with medical imaging, followed by inverse finite element (FE) analysis, the data may also serve for material characterization of foot tissue.

scholarly journals User Interface for the Acquisition and Characterization of Defects and Performed Rework in Multi-Stage Production Systems

Procedia CIRP ◽  
2018 ◽  
Vol 78 ◽  
pp. 243-248 ◽  
Author(s):  
Colin Reiff ◽  
Florian Eger ◽  
Tobias Korb ◽  
Hermann Freiberger ◽  
Alexander Verl
Keyword(s):  
User Interface ◽  
Production Systems ◽  
Multi Stage

Understanding the structure details when drying hydrate crystals of pharmaceuticals – interpretations from diffuse scattering and inter-modulation satellites of a partially dehydrated crystal

2014 ◽  
Vol 70 (3) ◽  
pp. 555-567 ◽  
Author(s):  
E. J. Chan ◽  
Q. Gao ◽  
M. Dabros
Keyword(s):  
Large Scale ◽  
Structural Information ◽  
Layer Structure ◽  
Modulated Structure ◽  
Drying Procedures ◽  
Pure Phase ◽  
Disordered Layer ◽  
Transitory Phase ◽  
Lower Water Content

Simplified models for the crystal lattice of the sesquihydrate form of the hemi-sulfate salt of (5S,6S,9R)-5-amino-6-(2,3-difluorophenyl)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-9-yl 4-(2-oxo-2,3-dihydro-1H-imidazol[4,5b]pyridin-1-yl)-1-piperidine carboxylate (BMS-927711, C28H29F2N6O3+) are used to calculate diffuse diffraction features in order to develop a mechanistic understanding of the dehydration process with respect to disruption of the lattice, since a Bragg model cannot be established. The model demonstrates that what we observe when the water leaves the crystal is partial transformation from the parent form to a child form (a new form, less hydrated and structurally related to the parent). Yet this `dried' structure is not a pure phase. It consists of semi-random layers of both child, parent and an interfacial layer which has a modulated structure that represents a transitory phase. Understanding the fact that a single `dried' crystal can have the disordered layer structure described as well as understanding mechanistic relationships between the phases involved can have implications in understanding the effect of common large scale bulk drying procedures. During the development of BMS-927711, difficulties did arise during characterization of the dried bulk when using only routine solid-state analysis. The material is now better understood from this diffraction study. The diffraction experiments also reveal intermodulation satellites, which upon interpretation yield even more structural information about the crystal transformation. The model suggests the mechanism of transformation is laminar in which layers of the crystal are driven to approach a stableB-centered supercell phase of lower water content.

Photoluminescence Characterization of p-type GaN:Mg

1997 ◽  
Vol 482 ◽  
Author(s):  
Dorina Corlatan ◽  
Joachim Krüger ◽  
Christian Kisielowski ◽  
Ralf Klockenbrink ◽  
Yihwan Kim ◽  
...  
Keyword(s):  
Layer Structure ◽  
Growth Conditions ◽  
Buffer Layers ◽  
Near Band Edge ◽  
Acceptor Pair ◽  
Donor Acceptor ◽  
Si Doped ◽  
P Type ◽  
Mg Doped

AbstractWe report on results of low-temperature photoluminescence measurements performed on GaN films, grown by molecular beam epitaxy (MBE) on sapphire substrates. The GaN films are either Mg doped (p-type) or consist of a Mg-doped layer on top of a Si doped GaN layer (n-type). In the p-doped samples, the sharpness of the donor-acceptor-pair transition is striking, three phonon replicas are clearly resolved. A transition band occurs around 3.4 eV, which becomes dominant for samples with an np-layer structure. The position and the composition of the near band edge transitions are influenced by the growth of the buffer layers. Depending on the growth conditions a transition at 3.51 eV can be observed.

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