Influence of heating rates on in situ resistance measurements of a bronze route Nb–Sn–Cu–Ta multifilamentary conductor

ABSTRACTIn-situ synthesis of a composite of MoSi2-Al2O3 was carried out by reacting a thermite mixture consisting of MoO3, Al, and Si powders. The reaction was found to be extremely fast and violent, and a diluent was required to moderate the reaction. Thermal behavior of the thermite mixture was studied using DTA at different heating rates, and DTA was interrupted at different temperatures to determine the reaction mechanism. X-ray characterization of the products obtained at different temperatures reveals that the mechanism consists of a reduction of MoO3 by Al to MoO2 followed by a simultaneous oxidation of Al to Al2O3 and synthesis reaction between reduced Mo and Si to form MoSi2. The rate determining step is found to be reduction of MoO2 by Al and oxidation of Al to Al2O3. The thermite reaction was moderated by adding Mo and Si to the mixture of MoO3, Al, and Si such that the ratio of MoSi2 to the thermite was in the range of 60:40 to 90:10.

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Effect of heating rates on superconducting properties of pure MgB2, carbon nanotube- and nano-SiC-doped in situ MgB2∕Fe wires

Applied Physics Letters ◽

10.1063/1.2126148 ◽

2005 ◽

Vol 87 (18) ◽

pp. 182504 ◽

Cited By ~ 28

Author(s):

S. K. Chen ◽

K. S. Tan ◽

B. A. Glowacki ◽

W. K. Yeoh ◽

S. Soltanian ◽

...

Keyword(s):

Carbon Nanotube ◽

Superconducting Properties ◽

Heating Rates

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Radiative forcing associated with a springtime case of Bodélé and Sudan dust transport over West Africa

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-10-8811-2010 ◽

2010 ◽

Vol 10 (4) ◽

pp. 8811-8858 ◽

Cited By ~ 3

Author(s):

C. Lemaître ◽

C. Flamant ◽

J. Cuesta ◽

J.-C. Raut ◽

P. Chazette ◽

...

Keyword(s):

West Africa ◽

Heating Rate ◽

Radiative Forcing ◽

Mineral Dust ◽

Regional Scale ◽

Longwave Radiation ◽

Heating Rates ◽

Dust Layer ◽

In Situ Observations

Abstract. The radiative forcing due to mineral dust over West Africa is investigated using the radiative code STREAMER, as well as remote sensing and in situ observations gathered during the African Monsoon Multidisciplinary Analysis Special Observing Period (AMMA SOP). We focus on two days (13 and 14 June 2006) of an intense and long-lasting episode of dust being lifted in remote sources in Chad and Sudan and transported across West Africa in the African easterly jet region, during which airborne operations were conducted at the regional scale, from the southern fringes of the Sahara to the Gulf of Guinea. Profiles of heating rates are computed from airborne LEANDRE 2 and space-borne CALIOP lidar observations using two mineral dust model constrained by airborne in situ data and ground-based sunphotometer obtained during the campaign. Complementary space-borne observations (from MODIS) and in-situ observations such as dropsondes are also used to take into account a realistic infrared contribution of the water vapour. We investigate the variability of the heating rate on the vertical within a dust plume, as well as the contribution of longwave radiation to the heating rate and the radiative forcing of dust during the nighttime. The sensitivity of the so-derived heating rate is also analyzed for some key variables for which the associated uncertainties are quite large. During daytime, the warming associated with the presence of dust was found to be between 1.5 K day−1 and 4 K day−1, on average, depending on altitude and latitude. Strong warming (i.e. heating rates as high as 8 K day−1) was also observed locally in some limited part of the dust plumes. Obviously, during nighttime much smaller values of heating/cooling are retrieved (less than ±1 K day−1) but large enough to modify the low tropospheric equilibrium. Furthermore, cooling is observed as the result of the longwave forcing in the dust layer, while warming is observed below the dust layer, in the monsoon layer.

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In-situ sounding of radiation flux profiles through the Arctic lower troposphere

10.5194/amt-2018-173 ◽

2018 ◽

Cited By ~ 1

Author(s):

Ralf Becker ◽

Marion Maturilli ◽

Rolf Philipona ◽

Klaus Behrens

Keyword(s):

Surface Composition ◽

Lower Troposphere ◽

Time Frame ◽

The Arctic ◽

Heating Rates ◽

Heterogeneous Terrain ◽

Near Surface ◽

Clear Sky ◽

Radiation Fluxes

Abstract. In-situ profiles of all four net radiation components were obtained at Ny Ålesund/Svalbard (78.9° N, 11.9° E) in the time frame May 04–21, 2015. Measurements could be performed using adapted high quality instrumentation classified as secondary standard carried by a tethered balloon system. Balloon lifted measurements of albedo under clear sky conditions demonstrate the altitude dependence of this parameter over heterogeneous terrain. Depending on the surface composition within the sensor's footprint, the albedo over predominantly snow covered surfaces was found to decrease to 53.4 % and 35.8 % compared to 73.1 % and 78.8 % measured with near surface references, respectively. Albedo profiles show an all-sky maximum at 150 m above surface level, and an averaged vertical change rate of −2.1 %/100 m (clear sky) and −3.4 %/100 m (overcast) above. Profiling of arctic low-level clouds reveals distinct vertical gradients in all radiation fluxes but longwave upward. Observed radiative cooling at cloud top with heating rates of −53 to −84 K/d in subsequent observations tend to be lower than suggested by 1-D simulations.

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Design and Application of a New Reactor for in Situ Infrared Spectroscopic Investigations of Heterogeneously Catalyzed Reactions

Applied Spectroscopy ◽

10.1366/0003702944028461 ◽

1994 ◽

Vol 48 (2) ◽

pp. 194-197 ◽

Cited By ~ 25

Author(s):

Gabriele Mirth ◽

Florian Eder ◽

Johannes A. Lercher

Keyword(s):

Heating Rates ◽

Time Resolved ◽

Ft Ir ◽

Temperature Programmed ◽

Kinetic Investigations ◽

Catalyzed Reactions ◽

Gas Chromatography Mass Spectroscopy ◽

Transparent Windows ◽

Desorption Reaction

A design of a metal reactor equipped with gas in- and outlet tubings and IR transparent windows is described. The IR cell approximates a wellstirred tank reactor and is suited for in situ kinetic investigations of catalytic reactions. While the catalyst, in contact with the reactants and products, is analyzed in situ by means of time-resolved FT-IR spectroscopy, the effluent gas stream is analyzed by gas chromatography mass spectroscopy. The reactor operates at temperatures up to 870 K; for applications of temperature-programmed desorption/reaction, linear heating rates between 1 and 20 K/min can be realized. Examples for applications are given.

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Visualizing models and observations of the thermosphere-ionosphere in support of the ESA EE10 candidate mission Daedalus

10.5194/egusphere-egu2020-7386 ◽

2020 ◽

Author(s):

Eelco Doornbos ◽

Theodoros Sarris ◽

Stylianos Tourgaidis ◽

Panagiotis Pirnaris ◽

Stephan Buchert ◽

...

Keyword(s):

Local Density ◽

Lower Thermosphere ◽

Satellite Orbits ◽

Heating Rates ◽

Satellite Mission ◽

Temporal And Spatial Variability ◽

Phase 0 ◽

Definition Of ◽

2D And 3D

Daedalus is a new satellite mission concept for studying the lower thermosphere-ionosphere (LTI). The mission is currently undergoing Phase 0 studies, funded by ESA as one of three missions that are candidates for becoming its Earth Explorer 10 mission (EE10).Using an elliptical orbit with a very low perigee (140 km and lower), the mission will make comprehensive in-situ measurements, including local density, composition, temperature and velocities of both the neutral and charged particles. An option of having two Daedalus satellites is being studied to allow better separation of temporal and spatial variability, and to better measure the strong vertical gradients and wave activity that occur in the LTI. The complete suite of instruments on Daedalus will allow the computation of higher level products such as local collision frequencies, conductivities and heating rates, along the orbit. The unique complementarity of instrumentation and orbit sampling over a large range of altitudes will be extremely valuable in advancing the science of the LTI region, which is a key region for many space weather phenomena. High quality visualizations of models and data are very important during the definition of the mission. They allow both experts and newcomers to the field to better comprehend the physics of the LTI region, how it couples with other regions and systems, as well as how Daedalus will be able to sample this region from its unconventional orbit. The presentation will showcase 2D and 3D visuals that were developed during the phase 0 studies, and that make use of empirical and physics-based models of the thermosphere-ionosphere, Earth's magnetic field and simulated satellite orbits.

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Experimental Measurements of Spectral Emissivity of Al-Si Coated Steel Blanks Undergoing Rapid Heating

Volume 8A: Heat Transfer and Thermal Engineering ◽

10.1115/imece2014-38375 ◽

2014 ◽

Cited By ~ 1

Author(s):

N. L. Chester ◽

M. A. Wells ◽

K. J. Daun

Keyword(s):

Heating Temperature ◽

Rapid Heating ◽

Spectral Emissivity ◽

Ex Situ ◽

Temperature History ◽

Detailed Knowledge ◽

Coated Steel ◽

Heating Rates ◽

Rapid Changes

Detailed knowledge of the blank temperature history is essential in hot forming die quenching, in order to ensure adequate austenitization of the steel and transformation of a protective Al-Si later into a permanent Al-Si-Fe coating. This, in turn, requires detailed knowledge of the blank emissivity, which is complicated by the fact that the coating undergoes rapid changes in surface chemistry, and surface roughness as it is heated. This paper spectral emissivity of Usibor® 1500 P as it undergoes heating. Samples were heated in a DSI Gleeble® 3500 under prescribed heating rates. The spectral emissivity was measured ex situ using an FTIR reflectometer, and in situ with a NIR-spectrometer. While the trends agree with manufacturer data in the cases of the as-received and final furnace heating temperature of 900°C, the spectral emissivity changes at a faster rate than previously reported.

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Analytical Electron Microscopy Studies of Bi-Substituted Garnet Films

MRS Proceedings ◽

10.1557/proc-232-119 ◽

1991 ◽

Vol 232 ◽

Cited By ~ 1

Author(s):

P. A. Crozier ◽

P. A. Labun ◽

T Suzuki

Keyword(s):

Electron Microscopy ◽

Analytical Electron Microscopy ◽

Second Phase ◽

Processing Conditions ◽

Transformation Kinetics ◽

Heating Rates ◽

Garnet Films ◽

Analytical Electron ◽

In Situ Heating

ABSTRACTIn-situ heating in an electron microscope, together with EDX and EELS analysis, was used to characterize as-deposited amorphous and transformed garnet films. It was found that upon initial crystallization, a non-uniform precipitation of a second phase occurred, altering the local chemistry and microstructure of the transformed film. In addition, to study the transformation kinetics in more detail some experiments were conducted at slower heating rates and lower temperatures. It is hoped that the data obtained can be correlated to magnetic property measurements and contribute to the development of improved processing conditions.

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