Use of thermal emission signals to characterize the impact of fully and partially molten plasma-sprayed zirconia particles on glass surfaces

Abstract In thermal spray processes, the coating structure is the result of flattening and cooling of molten droplets on the substrate. The study of the cooling time and evolution of the splat size during impact is then of the highest importance to understand the influence of the spray parameters and substrate characteristics on the coating structure. Measurement of particle temperature during impact requires the use of a high-speed 2-color pyrometer to collect the thermal emission of the particle during flattening. Simultaneous measurement of the splat size with this pyrometer is difficult since the size of the particle can change as it cools down. To measure the splat size independently, a new measurement technique has been developed. In this technique the splat size is measured from the attenuation of the radiation of a laser beam illuminating the particle during impact. Results are presented for plasma sprayed molybdenum particles impacting on a glass substrate at room temperature. It is shown that the molybdenum splat reaches its maximum extent about 2 microseconds after the impact. In this work, we show that this increase of the splat surface is followed by a phase during which the splat size decreases significantly during 2 to 3 microseconds.

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Exoplanet pollution in transit spectroscopy with the next-generation of infrared space telescopes

10.5194/epsc2020-432 ◽

2020 ◽

Author(s):

Giuseppe Morello ◽

Tiziano Zingales ◽

Marine Martin-Lagarde ◽

Rene Gastaud ◽

Christophe Cossou ◽

...

Keyword(s):

Thermal Emission ◽

Phase Curve ◽

Next Generation ◽

Space Telescopes ◽

System Parameters ◽

James Webb Space Telescope ◽

Infrared Wavelengths ◽

In Transit ◽

The Impact

The next generation of space telescopes is expected to deliver transmission spectra of exoplanet atmospheres with precision down to 10 parts per million (ppm). Therefore, it is required to model the astrophysical signals with even greater precision in order not to introduce significant biases for the characterization of the planet and its atmosphere. We discuss, in particular, the contribution of the planetary flux in the analysis of transit observations. Usually, the planetary flux is assumed to be a negligible fraction of the stellar flux, so called dark planet hypothesis. However, this hypothesis is not always valid, especially at the infrared wavelengths, around the peak of thermal emission from the planet. We identify two effects, named self-blend and phase-blend, that tend to bias the measured transit depth in opposite directions (the self-blend effect was already known from Kipping & Tinetti 2010). We introduce a novel sub-package of the software ExoTETHyS that can be used to estimate the amplitude of these two effects depending on the exoplanet system parameters, along with the derivation of the mathematical formulae. In this way, it is possible to identify some priority targets to observe longer transit windows, the secondary eclipse and/or the full phase-curve in order to reduce these potential biases. We also show the impact of the self- and phase-blend effects in the analysis of simulated transit spectra taken with the James Webb Space Telescope (JWST), including the results of the atmospheric retrievals. Our analysis takes into account the possible mitigation depending on the alternative data detrending methods. &#160;

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Assessing the impact of different sources of topographic data on 1-D hydraulic modelling of floods

Hydrology and Earth System Sciences Discussions ◽

10.5194/hessd-11-7375-2014 ◽

2014 ◽

Vol 11 (7) ◽

pp. 7375-7408 ◽

Cited By ~ 1

Author(s):

A. Md Ali ◽

D. P. Solomatine ◽

G. Di Baldassarre

Keyword(s):

Thermal Emission ◽

Low Cost ◽

Water Levels ◽

Flood Inundation ◽

Model Accuracy ◽

Hydraulic Models ◽

Topographic Data ◽

Ground Survey ◽

The Impact ◽

Different Sources

Abstract. Topographic data, such as digital elevation models (DEMs), are essential input in flood inundation modelling. DEMs can be derived from several sources either through remote sensing techniques (space-borne or air-borne imagery) or from traditional methods (ground survey). The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), the Shuttle Radar Topography Mission (SRTM), the Light Detection and Ranging (LiDAR), and topographic contour maps are some of the most commonly used sources of data for DEMs. These DEMs are characterized by different precision and accuracy. On the one hand, the spatial resolution of low-cost DEMs from satellite imagery, such as ASTER and SRTM, is rather coarse (around 30–90 m). On the other hand, LiDAR technique is able to produce a high resolution DEMs (around 1m), but at a much higher cost. Lastly, contour mapping based on ground survey is time consuming, particularly for higher scales, and may not be possible for some remote areas. The use of these different sources of DEM obviously affects the results of flood inundation models. This paper shows and compares a number of hydraulic models developed using HEC-RAS as model code and the aforementioned sources of DEM as geometric input. The study was carried out on a reach of the Johor River, in Malaysia. The effect of the different sources of DEMs (and different resolutions) was investigated by considering the performance of the hydraulic models in simulating flood water levels as well as inundation maps. The outcomes of our study show that the use of different DEMs has serious implications to the results of hydraulic models. The outcomes also indicates the loss of model accuracy due to re-sampling the highest resolution DEM (i.e. LiDAR 1 m) to lower resolution are much less compared to the loss of model accuracy due to the use of low-cost DEM that have not only a lower resolution, but also a lower quality. Lastly, to better explore the sensitivity of the hydraulic models to different DEMs, we performed an uncertainty analysis based on the GLUE methodology.

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Process Parameter Impact on Suspension-HVOF-Sprayed Cr2O3 Coatings

Journal of Thermal Spray Technology ◽

10.1007/s11666-019-00940-7 ◽

2019 ◽

Vol 28 (8) ◽

pp. 1933-1944 ◽

Cited By ~ 1

Author(s):

Jarkko Kiilakoski ◽

Richard Trache ◽

Stefan Björklund ◽

Shrikant Joshi ◽

Petri Vuoristo

Keyword(s):

Chromium Oxide ◽

High Velocity ◽

Atmospheric Plasma ◽

Promising Alternative ◽

Air Curtain ◽

Resistance To Sliding ◽

Wear And Corrosion ◽

And Performance ◽

Plasma Sprayed ◽

The Impact

Abstract Chromium oxide (Cr2O3) is commonly used as an atmospheric plasma-sprayed (APS) coating from powder feedstock in applications requiring resistance to sliding wear and corrosion, as well as amenability to texturing, e.g., in anilox rolls. Recently, high-velocity oxy-fuel spray methods involving suspension feedstock have been considered an extremely promising alternative to produce denser and more homogeneous chromium oxide coatings with lower as-sprayed surface roughness, higher hardness and potentially superior wear performance compared to conventional APS-sprayed coatings. In this study, the impact of process parameters namely auxiliary air cleaning nozzles and a transverse air curtain on suspension high-velocity oxy-fuel-sprayed Cr2O3 suspensions is presented. The produced coatings are characterized for their microstructure, mechanical properties and wear resistance by cavitation erosion. The results reveal the importance of optimized air nozzles and air curtain to achieve a vastly improved coating structure and performance.

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Parameterization of Surface Roughness Based on ICESat/GLAS Full Waveforms: A Case Study on the Tibetan Plateau

Journal of Hydrometeorology ◽

10.1175/jhm-d-12-0130.1 ◽

2013 ◽

Vol 14 (4) ◽

pp. 1278-1292 ◽

Cited By ~ 9

Author(s):

Junchao Shi ◽

Massimo Menenti ◽

Roderik Lindenbergh

Keyword(s):

Tibetan Plateau ◽

Thermal Emission ◽

Laser System ◽

Heat Fluxes ◽

Waveform Analysis ◽

The Tibetan Plateau ◽

Laser Altimeter ◽

Glacier Surface ◽

Engineering Research ◽

The Impact

Abstract Glaciers in the Tibetan mountains are expected to be sensitive to turbulent sensible and latent heat fluxes. One of the most significant factors of the energy exchange between the atmospheric boundary layer and the glacier is the roughness of the glacier surface. However, methods to parameterize this roughness for glacier surfaces in remote regions are not well known. In this paper, the authors use the data acquired by Ice, Cloud, and Land Elevation Satellite (ICESat)/Geoscience Laser Altimeter System (GLAS) laser altimetry from February 2003 to November 2004 along several tracks over glaciers of the Nyainqêntanglha range in central Tibet. The authors make a study of the waveforms measured by the ICESat/GLAS laser system over mountainous and glacial areas. The surface characteristics are evaluated within laser footprints over the glacier outlines based on the glaciological inventory of the Tibetan Plateau constructed by the Cold and Arid Regions Environmental and Engineering Research Institute (CAREERI), Chinese Academy of Sciences. For this purpose, the authors extract waveform parameters: the waveform width, the number of modes, and the RMS width of the waveform. These parameters are compared with surface slope and roughness obtained from the Advanced Spaceborne Thermal Emission and Reflection Radar (ASTER) Global Digital Elevation Model (GDEM). Through this analysis, the impact of morphology on the returned laser waveform is shown for the Nyainqêntanglha range. The roughness and the slope of the surface can be quite significant and may contribute from several meters to tens of meters to the pulse extent. The waveform analysis results indicate that the received waveforms are capable representations of surface relief within the GLAS footprints.

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Mathematical Modeling of Convective Heat and Mass Transfer of a Rotating Nano-Fluid Bounded by Stretching and Stationary Walls in a Vertical Conduit

International Journal of Applied Mechanics and Engineering ◽

10.2478/ijame-2020-0050 ◽

2020 ◽

Vol 25 (4) ◽

pp. 69-83

Author(s):

B. Haritha ◽

C. Umadevi ◽

M.Y. Dhange

Keyword(s):

Mass Transfer ◽

Heat And Mass Transfer ◽

Convective Heat ◽

Thermal Emission ◽

Skin Friction Coefficient ◽

Temperature Dependent ◽

Shooting Technique ◽

Transfer Rates ◽

Nano Fluid ◽

The Impact

AbstractThe influence of thermal emission and unvarying magnetic field of convective heat and mass transfer of a rotating nano-liquid in an upright conduit constrained by a stretching and motionless wall is studied. The temperature, concentration profile, primary and secondary velocities have been computed through similarity transformation and fourth-order Runge-Kutta shooting technique. The objective of this article is to measure the impact of emission constraint, Brownian movement constraint and Eckert number, thermophoresis constraint, Prandtl number, space, and temperature-dependent heat source constraint on velocity. The results are presented in tables and graphs. Further, various constraint impacts on the skin friction coefficient, heat and mass transfer rates are also explored. This work is pertinent to biotechnological and engineering uses, like mass and heat transfer enhancement of microfluids and design of bioconjugates.

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Tribological Characteristics of Carbon Nanotubes-Reinforced Plasma-Sprayed Al2O3-TiO2 Ceramic Coatings

Advances in Materials Science and Engineering ◽

10.1155/2021/8094640 ◽

2021 ◽

Vol 2021 ◽

pp. 1-12

Author(s):

Chaitanya Kalangi ◽

Venkateshwarlu Bolleddu ◽

Haiter Lenin Allasi

Keyword(s):

Carbon Nanotubes ◽

Oil And Gas ◽

Steel Substrate ◽

Ceramic Coatings ◽

Porous Coating ◽

Air Plasma ◽

Wear Performance ◽

Wide Range ◽

Plasma Sprayed ◽

The Impact

Thermal-sprayed coatings are widely used in various oil and gas industries for wear and corrosion applications. However, increasing performance and requirements make conventional coatings inadequate for future needs. Furthermore, the heat conductivity of bulk materials cannot be minimized easily. Therefore, the use of low porous coating with nanocomposite doping is an effective way to produce coatings with reduced thermal conductivity. Plasma-sprayed Al2O3-TiO2 coatings are found in a wide range of applications recently in many industries because of their exceptional properties including low expenses and ease of availability. In this work, the wear-resistant and low porous coatings of Al2O3 + 3 wt%TiO2 and respective carbon nanotube (CNT) doped coatings are prepared and characterized. The coatings are deposited on the AISI 1020 steel substrate using air plasma spraying. The impact of CNTs reinforcement on the percentage of pores and wear performance of coatings is investigated. Also, wear tracks morphology is investigated to determine the wear mechanism that is responsible for the wear of coatings. From the analysis, it is observed that the formation of cracks as well as micropores is decreased by the addition of carbon nanotubes. Moreover, uniform CNT distribution and good adhesion of coatings with the substrate are the major factors that improve the wear performance of the coated surface.

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Plasma Sprayed Zirconia: Relationships Between Particle Parameters, Splat Formation and Deposit Generation-Part I: Impact and Solidification

Thermal Spray 1996: Proceedings from the National Thermal Spray Conference ◽

10.31399/asm.cp.itsc1996p0623 ◽

1996 ◽

Author(s):

A.C. Léger ◽

M. Vardelle ◽

A. Vardelle ◽

P. Fauchais ◽

S. Sampath ◽

...

Keyword(s):

New York ◽

Research Work ◽

State University ◽

Characteristic Parameters ◽

Joint Research ◽

Splat Formation ◽

Particle Parameters ◽

Plasma Sprayed ◽

The University ◽

The Impact

Abstract Joint research work between the University of Limoges and the State University of New York, Stony Brook, has been carried out on the impact and solidification of plasma sprayed zirconia particles. A measurement device, consisting of a phase doppler particle analyser and a pyrometer, was used to correlate the characteristic parameters of splats to those of the substrate and to the size, velocity and temperature of the impacting particles.

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Microstructure and Oxidation Resistance of Laser Remelted Plasma Sprayed Nicraly Coating

Archives of Metallurgy and Materials ◽

10.1515/amm-2016-0197 ◽

2016 ◽

Vol 61 (2) ◽

pp. 1183-1191

Author(s):

D. Niemiec ◽

G. Moskal ◽

Ł. Carski

Keyword(s):

Laser Treatment ◽

Oxidation Resistance ◽

Laser Melting ◽

Nicraly Coating ◽

Plasma Sprayed Coatings ◽

Plasma Sprayed ◽

The Impact ◽

Sprayed Coatings ◽

Microscopic Investigations

Abstract The article presents results of research relating to the impact of laser treatment done to the surface of plasma sprayed coatings NiCrAlY. Analysis consisted microstructure and oxidation resistance of coatings subjected to two different laser melting surfaces. The test were performed at a temperature 1000°C the samples were removed from the furnace after 25, 300, 500, 750 and 1000 hours. The investigations range included analysis of top surface of coatings by XRD characterization oxides formed types and microscopic investigations of coatings morphology

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Backside Sample Preparation Challenges for Fault Localization Analysis of Flip Chip Package

ISTFA 2013: Conference Proceedings from the 39th International Symposium for Testing and Failure Analysis ◽

10.31399/asm.cp.istfa2013p0553 ◽

2013 ◽

Author(s):

Lihong Cao ◽

Donna Wallace ◽

Lynda Tuttle ◽

Kirk Martin

Keyword(s):

Image Quality ◽

Flip Chip ◽

Thermal Emission ◽

Photon Emission ◽

Fault Isolation ◽

Isolation Techniques ◽

High Uniformity ◽

Localization Analysis ◽

Mechanical Thinning ◽

The Impact

Abstract Mechanical thinning of Si die backside was introduced to support fault isolation for flip chip package in this paper. The backside milling system provides two types of thinning with good die planarity and mirror polishing to yield a high image quality for fault isolation techniques such as laser base thermal emission and photon emission techniques. In this paper, two mechanical thinning techniques were applied by using the 3D die curvature thinning and 2D planar thinning on flip chip Si backside. The impact of process parameters on die planarity and fault isolation were also discussed. The experimental results demonstrate the milling system’s high uniformity across the large die size and provide a very good solution for fault isolation techniques.

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