Water speciation in hydrous sodium tetrasilicate and hexasilicate melts: Constraint from high temperature NIR spectroscopy

2008 ◽  
Vol 256 (3-4) ◽  
pp. 306-315 ◽  
Author(s):  
Harald Behrens ◽  
Shigeru Yamashita
Keyword(s):  
High Temperature ◽  
Nir Spectroscopy ◽  
Water Speciation

scholarly journals Revisiting water speciation in hydrous alumino-silicate glasses: A discrepancy between solid-state 1H NMR and NIR spectroscopy in the determination of X-OH and H2O

2020 ◽  
Vol 285 ◽  
pp. 150-174 ◽  
Author(s):  
George D. Cody ◽  
Michael Ackerson ◽  
Carolyn Beaumont ◽  
Dionysis Foustoukos ◽  
Charles Le Losq ◽  
...  
Keyword(s):  
Solid State ◽  
1H Nmr ◽  
Nir Spectroscopy ◽  
Silicate Glasses ◽  
Alumino Silicate ◽  
Water Speciation

High-temperature Raman spectroscopy of silicate and aluminosilicate hydrous glasses: Implications for water speciation

1996 ◽  
Vol 128 (1-4) ◽  
pp. 25-39 ◽  
Author(s):  
François Holtz ◽  
Jean-Michel Bény ◽  
Bjorn O. Mysen ◽  
Michel Pichavant
Keyword(s):  
Raman Spectroscopy ◽  
High Temperature ◽  
Water Speciation

scholarly journals Response of Mycorrhizal ’Touriga Nacional‘ Variety Grapevines to High Temperatures Measured by Calorespirometry and Near-Infrared Spectroscopy

Plants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1499
Author(s):  
Amaia Nogales ◽  
Hugo Ribeiro ◽  
Julio Nogales-Bueno ◽  
Lee D. Hansen ◽  
Elsa F. Gonçalves ◽  
...  
Keyword(s):  
High Temperature ◽  
High Temperatures ◽  
Near Infrared ◽  
Nir Spectroscopy ◽  
Temperature Adaptation ◽  
Biochemical Processes ◽  
Before And After ◽  
Heat Shocks ◽  
Temperature Exposure ◽  
Sensitive Parameters

Heat stress negatively affects several physiological and biochemical processes in grapevine plants. In this work, two new methods, calorespirometry, which has been used to determine temperature adaptation in plants, and near-infrared (NIR) spectroscopy, which has been used to determine several grapevine-related traits and to discriminate among varieties, were tested to evaluate grapevine response to high temperatures. ‘Touriga Nacional’ variety grapevines, inoculated or not with Rhizoglomus irregulare or Funneliformis mosseae, were used in this study. Calorespirometric parameters and NIR spectra, as well as other parameters commonly used to assess heat injury in plants, were measured before and after high temperature exposure. Growth rate and substrate carbon conversion efficiency, calculated from calorespirometric measurements, and stomatal conductance, were the most sensitive parameters for discriminating among high temperature responses of control and inoculated grapevines. The results revealed that, although this vine variety can adapt its physiology to temperatures up to 40 °C, inoculation with R. irregulare could additionally help to sustain its growth, especially after heat shocks. Therefore, the combination of calorespirometry together with gas exchange measurements is a promising strategy for screening grapevine heat tolerance under controlled conditions and has high potential to be implemented in initial phases of plant breeding programs.

Discrimination of adulterants in UHT milk samples by NIRS coupled with supervision discrimination techniques

2016 ◽  
Vol 8 (39) ◽  
pp. 7204-7208 ◽  
Author(s):  
Aderval S. Luna ◽  
Jéssica S. A. Pinho ◽  
Luciana C. Machado
Keyword(s):  
High Temperature ◽  
Nir Spectroscopy ◽  
Uht Milk ◽  
Milk Samples ◽  
Ultra High Temperature

A methodology was developed for distinguishing different ultra-high temperature (UHT) milk adulterants (water, urea, and formaldehyde) at various levels using NIR spectroscopy (NIRS) coupled with supervision discrimination techniques (SIMCA, SVM-DA, and PLS-DA).

scholarly journals Development of High-Temperature Uv-Vis-Nir Spectroscopy for the Measurement of Free Energies of Complexation at Elevated Temperatures

1990 ◽  
Vol 212 ◽  
Author(s):  
Piotr Robouch ◽  
Pat Grant ◽  
Richard A. Torres ◽  
P. A. Baisden ◽  
R. J. Silva
Keyword(s):  
High Temperature ◽  
Optical Absorption ◽  
Elevated Temperatures ◽  
Fiber Optic ◽  
Equilibrium Constants ◽  
Nir Spectroscopy ◽  
Model System ◽  
Optical Absorption Spectra ◽  
Free Energies ◽  
Metal Ligand

ABSTRACTWe have developed instrumentation capable of measuring optical absorption spectra over a wavelength range of 200–1200 nm and a temperature range of 20–100°C. This fiber-optic based spectrometer generates data which allow the computation of metal-ligand equilibrium constants. Studies at five temperatures have been completed using praseodymium-diglycolate as a model system. Fundamental thermodynamic values (free energies, enthalpies, entropies) were obtained from the experimentally-determined stability constants.

scholarly journals Self-Initiated Butyl Acrylate Polymerizations in Bulk and in Solution Monitored By In-Line Techniques

Polymers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2021
Author(s):  
Jonas Mätzig ◽  
Marco Drache ◽  
Sabine Beuermann
Keyword(s):  
High Temperature ◽  
Linear Regression ◽  
Monomer Concentration ◽  
Nir Spectroscopy ◽  
Polymerization Rate ◽  
Additional Parameter ◽  
Initial Monomer Concentration ◽  
Rate Of Polymerization ◽  
Initial Monomer ◽  
Kinetics Of

High-temperature acrylate polymerizations are technically relevant, but yet not fully understood. In particular the mechanism and the kinetics of the thermal self-initiation is a topic of current research. To obtain more detailed information the conversion dependence of the polymerization rate, rbr, is determined via in-line DSC and FT-NIR spectroscopy for reactions in bulk and in solution at temperatures ranging from 80 to 160 °C. Solution polymerizations revealed that dioxane is associated with the highest rbr, while aromatic solvents result in the lowest values of rbr. Interestingly, rbr for polymerizations in solution with dioxane depends on the actual monomer concentration at a given time in the system, but is not depending on the initial monomer concentration. The overall rate of polymerization in bulk and in solution is well represented by an equation with three or four parameters, respectively, being estimated by multiple linear regression and the temperature as additional parameter.

The Applicability of near Infrared Reflectance Spectroscopy for Determining Solubility and Digestibility of Heated Protein under High Pressure

1995 ◽  
Vol 3 (2) ◽  
pp. 73-79 ◽  
Author(s):  
R.K. Cho ◽  
J.H. Lee ◽  
J.J. Ahn ◽  
Y. Ozaki ◽  
M. Iwamoto
Keyword(s):  
High Temperature ◽  
Structural Changes ◽  
Near Infrared ◽  
Linear Regression Analysis ◽  
Nir Spectroscopy ◽  
Reflectance Spectroscopy ◽  
Near Infrared Reflectance ◽  
Absorption Bands ◽  
Steel Cylinder ◽  
Temperature And Pressure

The potential of near infrared (NIR) reflectance spectroscopy for non-destructively probing structural changes in protein during the process of denaturation was investigated. Lysozyme as a model protein was adjusted to 15% moisture content, placed in a steel cylinder and then heated at 30, 90, 120 and 150°C under pressure conditions of 10, 15, 30 and 45 MPa. Significant changes were observed in absorption bands near 2144, 2168 and 2208 nm with increases in temperature and pressure. The spectral changes were, in general, much larger for samples subjected to both high temperature and pressure than for those subjected to high temperature only. It is likely that these changes are due to changes in the secondary structure of protein. Absorbance changes at the above wavelengths showed high correlations to variations in solubility and digestibility of protein treated under high heat and pressure conditions. The results of multiple linear regression analysis suggest that NIR spectroscopy may be used to predict the solubility and digestibility of protein.

Influence of Thermo-Mechanical Processing on the Microstructure of Beryllia Dispersed Nickel Alloys

1973 ◽  
Vol 31 ◽  
pp. 184-185
Author(s):  
M.S. Grewal ◽  
S.A. Sastri ◽  
N.J. Grant
Keyword(s):  
High Temperature ◽  
Nickel Alloys ◽  
Thermomechanical Processing ◽  
Cold Work ◽  
High Temperature Strength ◽  
Strengthening Effect ◽  
Mechanical Processing ◽  
Uniform Dispersion ◽  
Oxide Particles ◽  
Nickel Base

Currently there is a great interest in developing nickel base alloys with fine and uniform dispersion of stable oxide particles, for high temperature applications. It is well known that the high temperature strength and stability of an oxide dispersed alloy can be greatly improved by appropriate thermomechanical processing, but the mechanism of this strengthening effect is not well understood. This investigation was undertaken to study the dislocation substructures formed in beryllia dispersed nickel alloys as a function of cold work both with and without intermediate anneals. Two alloys, one Ni-lv/oBeo and other Ni-4.5Mo-30Co-2v/oBeo were investigated. The influence of the substructures produced by Thermo-Mechanical Processing (TMP) on the high temperature creep properties of these alloys was also evaluated.

Application of TEM to Deformation, Wear, and Fracture of Ceramics

1974 ◽  
Vol 32 ◽  
pp. 472-473
Author(s):  
B. J. Hockey
Keyword(s):  
Wear Resistance ◽  
High Temperature ◽  
Mechanical Behavior ◽  
Brittle Materials ◽  
High Temperature Strength ◽  
Wide Range ◽  
Corrosive Environments ◽  
Further Development

Ceramics, such as Al2O3 and SiC have numerous current and potential uses in applications where high temperature strength, hardness, and wear resistance are required often in corrosive environments. These materials are, however, highly anisotropic and brittle, so that their mechanical behavior is often unpredictable. The further development of these materials will require a better understanding of the basic mechanisms controlling deformation, wear, and fracture.The purpose of this talk is to describe applications of TEM to the study of the deformation, wear, and fracture of Al2O3. Similar studies are currently being conducted on SiC and the techniques involved should be applicable to a wide range of hard, brittle materials.

Lattice Imaging of Grain Boundaries in Ceramics

1977 ◽  
Vol 35 ◽  
pp. 114-115
Author(s):  
D. R. Clarke ◽  
G. Thomas
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Silicon Nitride ◽  
Grain Boundaries ◽  
High Temperature Strength ◽  
Current Interest ◽  
Lattice Imaging ◽  
Special Significance ◽  
Structural Applications ◽  
Refractory Ceramics

Grain boundaries have long held a special significance to ceramicists. In part, this has been because it has been impossible until now to actually observe the boundaries themselves. Just as important, however, is the fact that the grain boundaries and their environs have a determing influence on both the mechanisms by which powder compaction occurs during fabrication, and on the overall mechanical properties of the material. One area where the grain boundary plays a particularly important role is in the high temperature strength of hot-pressed ceramics. This is a subject of current interest as extensive efforts are being made to develop ceramics, such as silicon nitride alloys, for high temperature structural applications. In this presentation we describe how the techniques of lattice fringe imaging have made it possible to study the grain boundaries in a number of refractory ceramics, and illustrate some of the findings.

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