Sintering of Nanophase TiO2 At 550°C

1988 ◽  
Vol 132 ◽  
Author(s):  
J. E. Epperson ◽  
R. W. Siegel ◽  
J. W. White ◽  
T. E. Klippert ◽  
A. Narayanasamy ◽  
...  
Keyword(s):  
Small Angle Neutron Scattering ◽  
Size Distributions ◽  
Entropy Analysis ◽  
Analysis Method ◽  
In Situ Oxidation ◽  
Scattering Centers ◽  
Microstructural Model ◽  
Thin Disks ◽  
Wide Boundary

ABSTRACTSamples of nanophase TiO2 were prepared by the condensation of Ti vapors into clusters, their in situ oxidation to TiO2, and their consolidation into thin disks. Small angle neutron scattering was measured in the as-consolidated condition and after selected isothermal sintering anneals of up to 23 h at 550°C. The maximum entropy analysis method was used to obtain the size distributions of the scattering centers from the scattering curves. The results are interpreted in terms of a microstructural model consisting of nanometer sized grains of TiO2 separated by about 0.5 nm wide boundary regions, which contain voids and TiO2 of ≤60–70% of bulk density.

Tuning the Magnetic Alignment of Cellulose Nanocrystals from Perpendicular to Parallel Using Lepidocrocite Nanoparticles

2019 ◽  
Author(s):  
Valentina Guccini ◽  
Sugam Kumar ◽  
Yulia Trushkina ◽  
Gergely Nagy ◽  
Christina Schütz ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Cellulose Nanocrystals ◽  
Small Angle Neutron Scattering ◽  
Lower Amount ◽  
Magnetic Alignment ◽  
Polarized Optical Microscopy ◽  
Parallel Orientation ◽  
Weak Magnetic Fields

The magnetic alignment of cellulose nanocrystals (CNC) and lepidocrocite nanorods (LpN), pristine and in hybrid suspensions has been investigated using contrast-matched small-angle neutron scattering (SANS) under in situ magnetic fields (0 – 6.8 T) and polarized optical microscopy. The pristine CNC (diamagnetic) and pristine LpN (paramagnetic) align perpendicular and parallel to the direction of field, respectively. The alignment of both the nanoparticles in their hybrid suspensions depends on the relative amount of the two components (CNC and LpN) and strength of the applied magnetic field. In the presence of 10 wt% LpN and fields < 1.0 T, the CNC align parallel to the field. In the hybrid containing lower amount of LpN (1 wt%), the ordering of CNC is partially frustrated in all range of magnetic field. At the same time, the LpN shows both perpendicular and parallel orientation, in the presence of CNC. This study highlights that the natural perpendicular ordering of CNC can be switched to parallel by weak magnetic fields and the incorporation of paramagnetic nanoparticle as LpN, as well it gives a method to influence the orientation of LpN.<br>

Technology Status Review In Situ Oxidation

1999 ◽  
Author(s):  
VIRGINIA UNIV CHARLOTTESVILLE
Keyword(s):  
In Situ Oxidation

Laccase-Mediated In Situ Oxidation of Dopamine for Dyeing of Human Hair

2021 ◽  
Vol 22 (1) ◽  
pp. 141-148
Author(s):  
Weini Jia ◽  
Shirong Li ◽  
Zhengxin Luo ◽  
Hainan Yu ◽  
Wenjun Zhu ◽  
...  
Keyword(s):  
Human Hair ◽  
In Situ Oxidation

An automatic analysis method for in situ hybridization using high-resolution image analysis

1989 ◽  
Vol 281 (5) ◽  
pp. 336-341 ◽  
Author(s):  
W. Stolz ◽  
K. Scharffetter ◽  
W. Abmayr ◽  
W. K�ditz ◽  
T. Krieg
Keyword(s):  
Image Analysis ◽  
In Situ Hybridization ◽  
High Resolution ◽  
Automatic Analysis ◽  
Analysis Method ◽  
Resolution Image ◽  
High Resolution Image

Electronic spectroscopy of iron alloys in the process of in-situ oxidation

2000 ◽  
Vol 36 (3) ◽  
pp. 406-411
Author(s):  
M. G. Nakhodkin ◽  
V. M. Lysenko ◽  
I. P. Koval ◽  
O. F. Bardamyd
Keyword(s):  
Electronic Spectroscopy ◽  
Iron Alloys ◽  
In Situ Oxidation

Back Analysis Methods in Geotechnical Engineering

2014 ◽  
Vol 1020 ◽  
pp. 423-428 ◽  
Author(s):  
Eva Hrubesova ◽  
Marek Mohyla
Keyword(s):  
Rock Mass ◽  
Geotechnical Engineering ◽  
Back Analysis ◽  
Rheological Parameters ◽  
Analysis Method ◽  
Direct Optimization ◽  
Initial Stress State ◽  
Analytical Functions ◽  
Is Evaluation

The paper deals with the back analysis method in geotechnical engineering, that goal is evaluation the more objective and reliable parameters of the rock mass on the basis of in-situ measurements. Stress, deformational, strength and rheological parameters of the rock mass are usually determined by some inaccuracies and errors arising from the complexity and variability of the rock mass. This higher or lower degree of imprecision is reflected in the reliability of the mathematical modelling results. The paper presents the utilization of direct optimization back analysis method, based on the theory of analytical functions of complex variable and Kolosov-Muschelischvili relations, to the evaluation of initial stress state inside the rock massif.

scholarly journals Methodology for determining rom size distribution

2014 ◽  
Vol 67 (4) ◽  
pp. 405-412
Author(s):  
Christiane Ribeiro da Silva ◽  
Vládia C. G. de Souza ◽  
Jair C. Koppe
Keyword(s):  
Size Distribution ◽  
Distribution Curve ◽  
Size Distributions ◽  
Sampling Protocol ◽  
Product Size ◽  
Operational Conditions ◽  
Specific Protocol ◽  
Open Side ◽  
Ore Dressing

A methodology to determine the size distribution curve of the ROM was developed in a Brazilian iron ore mine. The size of the larger fragments was determined taking photographs and setting the scale of the images to analyze their dimensions (length of their edges and areas). This was implemented according to a specific protocol of sampling that involves split and homogenization stages in situ of a considerable quantity of ore (about 259 metric tonnes). During the sampling process, larger fragments were separated and smaller size material was screened. The methodology was developed initially in order to preview the performance of a primary gyratory crusher that is fed directly from trucks. Operational conditions of the equipment such as closed and open-side settings could be adjusted previously, obtaining different product size distributions. Variability of size of the fragments affects subsequent stages of crushing and can increase circulating load in the circuit. This leads to a decrease of productivity or recovery of the ore dressing. The results showed insignificant errors of accuracy and reproducibility of the sampling protocol when applied to friable itabirite rocks.

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