scholarly journals Effect of probe geometry during measurement of >100 A Ga2O3 vertical rectifiers

2021 ◽  
Vol 39 (1) ◽  
pp. 013406
Author(s):  
Ribhu Sharma ◽  
Minghan Xian ◽  
Chaker Fares ◽  
Mark E. Law ◽  
Marko Tadjer ◽  
...  
Keyword(s):  
Probe Geometry

scholarly journals Can gravitational microlensing be used to probe geometry of a massive black-hole?

2006 ◽  
Vol 2 (S238) ◽  
pp. 431-432
Author(s):  
Luka Č Popović ◽  
Predrag Jovanović
Keyword(s):  
Black Hole ◽  
Line Shape ◽  
X Rays ◽  
Massive Black Hole ◽  
Gravitational Microlensing ◽  
Probe Geometry

AbstractHere we discuss the possibility to use gravitational microlensing in order to probe the geometry around a massive black hole. Taking into account that lensed quasars are emitting X-rays which come from the heart of these objects, we investigated the influence of microlensing on the Fe Kα line shape originated in Schwarzschild and Kerr metrics.

Detection of inorganic chemicals in a sandy soil using TDR: Effect of probe geometry and water content

2010 ◽  
Vol 14 (3) ◽  
pp. 321-326 ◽  
Author(s):  
Min-Hee Kim ◽  
Dong-Ju Kim ◽  
Jae-Woo Choi ◽  
Hyoung-Soo Kim ◽  
Chun-Sik Kim
Keyword(s):  
Water Content ◽  
Sandy Soil ◽  
Probe Geometry

Evaluation of a Flow Measurement Probe Influence on the Flow Field in High Speed Axial Compressors

2021 ◽  
Author(s):  
Ryosuke Seki ◽  
Satoshi Yamashita ◽  
Ryosuke Mito
Keyword(s):  
Flow Field ◽  
Approximation Method ◽  
High Speed ◽  
Static Pressure ◽  
Axial Compressor ◽  
Pressure Change ◽  
Operating Point ◽  
Blade Row ◽  
Probe Insertion ◽  
Probe Geometry

Abstract The aerodynamic effects of a probe for stage performance evaluation in a high-speed axial compressor are investigated. Regarding the probe measurement accuracy and its aerodynamic effects, the upstream/downstream effects on the probe and probe insertion effects are studied by using an unsteady computational fluid dynamics (CFD) analysis and by verifying in two types of multistage high-speed axial compressor measurements. The probe traverse measurements were conducted at the stator inlet and outlet in each case to evaluate blade row performance quantitatively and its flow field. In the past study, the simple approximation method was carried out which considered only the interference of the probe effect based on the reduction of the mass flow by the probe blockage for the compressor performance, but it did not agree well with the measured results. In order to correctly and quantitatively grasp the mechanism of the flow field when the probe is inserted, the unsteady calculation including the probe geometry was carried out in the present study. Unsteady calculation was performed with a probe inserted completely between the rotor and stator of a 4-stage axial compressor. Since the probe blockage and potential flow field, which mean the pressure change region induced by the probe, change the operating point of the upstream rotor and increase the work of the rotor. Compared the measurement result with probe to a kiel probe setting in the stator leading edge, the total pressure was increased about 2,000Pa at the probe tip. In addition, the developed wake by the probe interferes with the downstream stator row and locally changes the static pressure at the stator exit. To evaluate the probe insertion effect, unsteady calculations with probe at three different immersion heights at the stator downstream in an 8-stage axial compressor are performed. The static pressure value of the probe tip was increased about 3,000Pa in the hub region compared to tip region, this increase corresponds to the measurement trend. On the other hand, the measured wall static pressure showed that there is no drastic change in the radial direction. In addition, when the probe is inserted from the tip to hub region in the measurement, the blockage induced by the probe was increased. As a result, operating point of the stator was locally changed, and the rise of static pressure of the stator increased when the stator incidence changed. These typical results show that unsteady simulations including probe geometry can accurately evaluate the aerodynamic effects of probes in the high-speed axial compressor. Therefore, since the probe will pinpointed and strong affects the practically local flow field in all rotor upstream passage and stator downstream, as for the probe measurement, it is important to pay attention to design the probe diameter, the distance from the blade row, and its relative position to the downstream stator. From the above investigations, a newly simple approximation method which includes the effect of the pressure change evaluation by the probe is proposed, and it is verified in the 4-stage compressor case as an example. In this method, the effects of the distance between the rotor trailing edge (T.E.) and the probe are considered by the theory of the incompressible two-dimensional potential flow. The probe blockage decreases the mass flow rate and changes the operating point of the compressor. The verification results conducted in real compressor indicate that the correct blockage approximation enables designer to estimate aerodynamic effects of the probe correctly.

scholarly journals The Effect of Probe Geometry on Rind Puncture Resistance Testing of Maize Stalks

2020 ◽  
Author(s):  
Douglas D. Cook ◽  
Kyler Meehan ◽  
Levan Asatiani ◽  
Daniel J Robertson
Keyword(s):  
Meta Analysis ◽  
Resistance Testing ◽  
Test Results ◽  
Lodging Resistance ◽  
Puncture Resistance ◽  
Analysis Of Results ◽  
Stalk Lodging ◽  
Penetration Tests ◽  
Shape And Size ◽  
Probe Geometry

Abstract Background: Stalk lodging (breaking of plant stems prior to harvest) is a major impediment to increasing agricultural yields of grain crops. Rind puncture resistance is commonly used to predict the lodging resistance of several crop species. However, there exist no standard operating procedures or suggested protocols for conducting rind penetration experiments. In addition, experimental details of rind penetration tests such as the shape and size of the penetrating probe are rarely reported in the literature. This has prevented meta-analysis of results and has likewise prevented key findings of past studies from being replicated. As a first step towards establishing an agreed upon measurement standard for rind puncture resistance this study investigates the effect of the puncturing probe’s geometry on test results.Results: Results demonstrate that probe geometry has a significant impact on test results. In particular, results showed that a 2mm diameter chamfered probe produced stronger correlations with stalk bending strength than a 1.5mm diameter pointed probe. The chamfered probe was also more strongly correlated with geometric features of the stalk that are known to influence stalk lodging resistance (e.g., rind thickness, diameter and section modulus). In addition, several alternative rind penetration metrics were investigated, and some were found to be superior to the most common rind penetration metric of maximum load. Conclusions:There is a need in the agricultural and plant science community to create agreed-upon operating procedures and testing standards related to mechanical traits of plant stems. In particular, a standardized probe geometry and insertion rate for rind penetration studies are needed to enable greater interoperability and meta-analysis of results. Probe shape and size should be reported in any study conducting rind penetration tests as these factors significantly impact test results.

scholarly journals Measurement station for interim inspections of Lightbridge metallic fuel rods at the Halden Boiling Water Reactor

2018 ◽  
Vol 170 ◽  
pp. 04011 ◽  
Author(s):  
C. Hartmann ◽  
A. Totemeier ◽  
S. Holcombe ◽  
J. Liverud ◽  
M. Limi ◽  
...  
Keyword(s):  
Cross Section ◽  
Eddy Current ◽  
Boiling Water ◽  
Third Party ◽  
Boiling Water Reactor ◽  
Bonding Layer ◽  
Metallic Fuel ◽  
Fuel Rods ◽  
Water Reactor ◽  
Probe Geometry

Lightbridge Corporation has developed a new Uranium-Zirconium based metallic fuel. The fuel rods aremanufactured via a co-extrusion process, and are characterized by their multi-lobed (cruciform-shaped) cross section. The fuel rods are also helically-twisted in the axial direction. Two experimental fuel assemblies, each containing four Lightbridge fuel rods, are scheduled to be irradiated in the Halden Boiling Water Reactor (HBWR) starting in 2018. In addition to on-line monitoring of fuel rod elongation and critical assembly conditions (e.g. power, flow rates, coolant temperatures, etc.) during the irradiation, several key parameters of the fuel will be measured out-of-core during interim inspections. An inspection measurement station for use in the irradiated fuel handling compartment at the HBWR has therefore been developed for this purpose. The multi-lobed cladding cross section combined with the spiral shape of the Lightbridge metallic fuel rods requires a high-precision guiding system to ensure good position repeatability combined with low-friction guiding. The measurement station is equipped with a combination of instruments and equipment supplied from third-party vendors and instruments and equipment developed at Institute for Energy Technology (IFE). Two sets of floating linear voltage differential transformer (LVDT) pairs are used to measure swelling and diameter changes between the lobes and the valleys over the length of the fuel rods. Eddy current probes are used to measure the thickness of oxide layers in the valleys and on the lobe tips and also to detect possible surface cracks/pores. The measurement station also accommodates gamma scans. Additionally, an eddy-current probe has been developed at IFE specifically to detect potential gaps or discontinuities in the bonding layer between the metallic fuel and the Zirconium alloy cladding. Potential gaps in the bonding layer will be hidden behind a 0.5-1.0 mm thick cladding wall. It has therefore been necessary to perform a careful design study of the probe geometry. For this, finite element analysis (FEA) has been performed in combination with practical validation tests on representative fuel dummies with machined flaws to find the probe geometry that best detects a hidden flaw. Tests performed thus far show that gaps down to 25 μm thickness can be detected with good repeatability and good discrimination from lift-off signals.

Generalizing the Theory of Microdialysis

2002 ◽  
Author(s):  
Rupak K. Banerjee ◽  
Peter M. Bungay ◽  
Malisa Sarntinoranont ◽  
Srinivas Chippada
Keyword(s):  
In Vivo Microdialysis ◽  
Convective Transport ◽  
Low Molecular Weight ◽  
Cross Sectional ◽  
Bulk Fluid ◽  
Solute Movement ◽  
Dominant Process ◽  
Hydrophilic Solutes ◽  
Probe Geometry

The efficiency of sampling or delivering solutes (analytes) by in vivo microdialysis is influenced by the diffusive permeabilities of the probe and the tissue in which the probe is implanted. In tissue, processes removing the analyte from the extracellular space are as important as diffusion in determining permeability. In addition to diffusion, analyte permeation through these media may be augmented or diminished by bulk fluid movement (transmembrane and interstitial convection). Within the perfusate, the dominant process is axial convection. Both diffusive and convective determinants of probe efficiency may be influenced by probe geometry (Figure 1; longitudinal cross-sectional view). The main geometric parameters are the probe membrane length and radii, but inner cannula geometry can also be an appreciable factor. The objective of this study is to generalize the mathematical description of microdialysis. The treatment extends in several ways previous mathematical models (Bungay et al. [1]; Morrison et al. [2]; Morrison et al. [3]; Wallgren et al. [4]). In addition to removing some simplifications and approximations and adding convective transport, the revised theory is applicable to low-molecular-weight lipophilic, as well as hydrophilic solutes. This is achieved by incorporating transcellular solute movement as a pathway paralleling interstitial diffusion. This change accompanies employing the combined intracellular and extracellular volumes, rather than the interstitial volume, as the basis for solute mass balances.

Acoustic impedance measurements—correction for probe geometry mismatch

2005 ◽  
Vol 117 (5) ◽  
pp. 2889-2895 ◽  
Author(s):  
N. H. Fletcher ◽  
J. Smith ◽  
A. Z. Tarnopolsky ◽  
J. Wolfe
Keyword(s):  
Acoustic Impedance ◽  
Impedance Measurements ◽  
Probe Geometry
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