Characterization of defects in tabular silver halide grains

1990 ◽  
Vol 48 (4) ◽  
pp. 1046-1047
Author(s):  
C. Goessens ◽  
D. Schryvers ◽  
J. Van Landuyt ◽  
A. Verbeeck ◽  
R. De Keyzer
Keyword(s):  
Radiation Damage ◽  
Silver Halide ◽  
Chemical Characteristics ◽  
X Ray ◽  
Free Region ◽  
Central Defect ◽  
Crystallographic Defects ◽  
Physical And Chemical ◽  
Two Sides

Silver halide grains (AgX, X=Cl,Br,I) are commonly recognized as important entities in photographic applications. Depending on the preparation specifications one can grow cubic, octahedral, tabular a.o. morphologies, each with its own physical and chemical characteristics. In the present study crystallographic defects introduced by the mixing of 5-20% iodide in a growing AgBr tabular grain are investigated. X-ray diffractometry reveals the existence of a homogeneous Ag(Br1-xIx) region, expected to be formed around the AgBr kernel. In fig. 1 a two-beam BF image, taken at T≈100 K to diminish radiation damage, of a triangular tabular grain is presented, clearly showing defect contrast fringes along four of the six directions; the remaining two sides show similar contrast under relevant diffraction conditions. The width of the central defect free region corresponds with the pure AgBr kernel grown before the mixing with I. The thickness of a given grain lies between 0.15 and 0.3 μm: as indicated in fig. 2 triangular (resp. hexagonal) grains exhibit an uneven (resp. even) number of twin interfaces (i.e., between + and - twin variants) parallel with the (111) surfaces. The thickness of the grains and the existence of the twin variants was confirmed from CTEM images of perpendicular cuts.

scholarly journals Characterization of Spent Ni-MH Batteries

2012 ◽  
Vol 730-732 ◽  
pp. 569-574
Author(s):  
Marta Cabral ◽  
Fernanda Margarido ◽  
Carlos A. Nogueira
Keyword(s):  
Quantitative Analysis ◽  
Electrode Materials ◽  
Phase Identification ◽  
Recycling Process ◽  
X Ray ◽  
Leaching Experiments ◽  
Plastic Components ◽  
Definition Of ◽  
Physical And Chemical

Spent Ni-MH batteries are not considered too dangerous for the environment, but they have a considerable economical value due to the chemical composition of electrodes which are highly concentrated in metals. The present work aimed at the physical and chemical characterisation of spent cylindrical and thin prismatic Ni-MH batteries, contributing for a better definition of the recycling process of these spent products. The electrode materials correspond to more than 50% of the batteries weight and contain essentially nickel and rare earths (RE), and other secondary elements (Co, Mn, Al). The remaining components are the steel parts from the external case and supporting grids (near 30%) containing Fe and Ni, and the plastic components (<10%). Elemental quantitative analysis showed that the electrodes are highly concentrated in metals. Phase identification by X-ray powder diffraction combined with chemical analysis and leaching experiments allowed advancing the electrode materials composition. The cathode is essentially constituted by 6% metallic Ni, 66% Ni(OH)2, 4.3% Co(OH)2 and the anode consists mainly in 62% RENi5 and 17% of substitutes and/or additives such as Co, Mn and Al.

HIGH RESOLUTION MINERALOGICAL CHARACTERIZATION OF SEDIMENTS - LAKE BOLĂTĂU-FEREDEU (ROMANIA)

2021 ◽  
Vol 16 (1) ◽  
pp. 199-210
Author(s):  
Máté Karlik ◽  
◽  
Ildikó GYOLLAI ◽  
Anna VANCSIK ◽  
Krisztián FINTOR ◽  
...  
Keyword(s):  
High Resolution ◽  
Chemical Weathering ◽  
Soil Formation ◽  
Mineralogical Characterization ◽  
X Ray ◽  
Geochemical Conditions ◽  
Formation Conditions ◽  
Physical And Chemical ◽  
Microbial Mediation

The catchment (bedrock and soil) and sediments of lake Bolătău, Romania were studied by high resolution multi-methodological investigations to characterize paleoenvironmental and formation conditions. Particle size analyses, optical and cathodoluminescence microscopy, FTIR-ATR and Raman spectroscopy, X-ray powder diffraction, and XRF were applied for microtextural, chemical, micro-mineralogical and embedded organic material characterization and distribution of the sediments, especially concerning geochemical conditions, like pH and redox potential change. Our results support physical and chemical weathering in the process of soil formation with appearance of the new minerals appear (10Å sized phyllosilicates and clay minerals). Comparison of these studies offer possible differentiation of syn- and diagenetic mineralization, the clarification of debris contribution, microbial mediation and complex mineralization via decomposition of cell and extracellular polymeric substance. Based on the analyses on the abrasives, a suboxic environment prevailed in the depositional area and considerable microbial contribution is proposed via accumulation of lake sediments.

Characterization of Surface Roughness

2000 ◽  
Vol 6 (S2) ◽  
pp. 916-917
Author(s):  
John C. Russ
Keyword(s):  
Surface Roughness ◽  
Chemical Deposition ◽  
Irregular Surfaces ◽  
X Ray ◽  
Surface Areas ◽  
Raster Scan ◽  
Vertical Displacements ◽  
Physical And Chemical ◽  
Deposition Techniques

Because of the session at this Microscopy and Microanalysis 2000 meeting concerned with the microanalysis of irregular surfaces, it seems appropriate to briefly review the methods used for the characterization of rough surfaces. This includes both mathematical tools for the concise description of surface roughness, and instruments used to acquire the necessary data. These methods are widely used in industry to characterize and specify the roughness of surfaces prepared by various machining, grinding, polishing, chemical etching, and physical and chemical deposition techniques, and to correlate the surface roughness with performance.Historically, surface roughness has been measured by performing a linear traverse with a mechanical stylus that is sensitive to vertical displacements of nm but with a lateral resolution on the order of pm, which is quite similar to the dimensions of the region analyzed by X-ray microanalysis. Recently, more comprehensive characterizations have been obtained using a raster scan over surface areas.

Limiting radiation damage for high-brilliance biological solution scattering: practical experience at the EMBL P12 beamline PETRAIII

2015 ◽  
Vol 22 (2) ◽  
pp. 273-279 ◽  
Author(s):  
Cy M. Jeffries ◽  
Melissa A. Graewert ◽  
Dmitri I. Svergun ◽  
Clément E. Blanchet
Keyword(s):  
Radiation Damage ◽  
Practical Experience ◽  
Quality Data ◽  
Biological Macromolecules ◽  
Sample Handling ◽  
X Ray ◽  
X Ray Scattering ◽  
Sample Position ◽  
Effects Of Radiation

Radiation damage is the general curse of structural biologists who use synchrotron small-angle X-ray scattering (SAXS) to investigate biological macromolecules in solution. The EMBL-P12 biological SAXS beamline located at the PETRAIII storage ring (DESY, Hamburg, Germany) caters to an extensive user community who integrate SAXS into their diverse structural biology programs. The high brilliance of the beamline [5.1 × 1012 photons s−1, 10 keV, 500 (H) µm × 250 (V) µm beam size at the sample position], combined with automated sample handling and data acquisition protocols, enable the high-throughput structural characterization of macromolecules in solution. However, considering the often-significant resources users invest to prepare samples, it is crucial that simple and effective protocols are in place to limit the effects of radiation damage once it has been detected. Here various practical approaches are evaluated that users can implement to limit radiation damage at the P12 beamline to maximize the chances of collecting quality data from radiation sensitive samples.

Characterization of Shivirtui Zeolite Modified with Aluminum Oxyhydroxide Nanofibers

2019 ◽  
Vol 942 ◽  
pp. 40-49
Author(s):  
Yulia Murashkina ◽  
Olga B. Nazarenko
Keyword(s):  
Chemical Properties ◽  
Nitrogen Adsorption ◽  
X Ray Diffraction ◽  
Scanning Electronic Microscopy ◽  
Electronic Microscopy ◽  
X Ray ◽  
Physical And Chemical ◽  
And Chemical Properties ◽  
Aluminum Oxyhydroxide

Natural zeolite of Shivirtui deposit (Russia) was modified with nanofibers of aluminum oxyhydroxide AlOOH. Aluminum oxyhydroxide nanofibers were produced at the heating and oxidation of aluminum powder with water. The properties of modified zeolite were investigated by means of X-ray diffraction, transmission electronic microscopy, scanning electronic microscopy, low-temperature nitrogen adsorption, thermal analysis, and Fourier transform infrared spectroscopy. It was found that water content in the modified sample of zeolite was about 15 %. Based on the study of the physical and chemical properties, shivirtui zeolite modified with nanofibers of aluminum oxyhydroxide can be proposed for use as a flame-retardant additive to polymers.

Characterization of Radiation Damage at the Nb Site in Natural Pyrochlores and Samarskites by X-Ray Absorption Spectroscopy

1988 ◽  
Vol 127 ◽  
Author(s):  
R. B. Greegor ◽  
F. W. Lytle ◽  
B. C. Chakoumakos ◽  
G. R. Lumpkin ◽  
J. K. Warner ◽  
...  
Keyword(s):  
Radiation Damage ◽  
Long Range ◽  
Absorption Spectroscopy ◽  
Alpha Decay ◽  
Long Range Order ◽  
Static Disorder ◽  
Annealed Condition ◽  
X Ray ◽  
X Ray Absorption

ABSTRACTX-ray absorption spectroscopy has been used to investigate the Nb B-site in pyrochlores (A1.2B2O6Y0–1, Fd3m, Z=8) and samarskites (A3B5O16) in both metamict and annealed condition. The XANES and EXAFS measurements indicate significant changes in pyrochlore and smaller changes in samarskite as a result of radiation damage. In the metamict state the Nb site in both pyrochlores and samarskites is similar to Nb in Nb2O5. Short Nb-O (1.65Å) bonds are not disrupted by alpha-decay/recoil-nuclei events as much as longer bonds (2.00Å). This increases the asymmetry and static disorder at the local Nb site while long range order is greatly diminished resulting in considerable distribution in Nb-M distances and bond angles.

Characterization of “Stickies” Polymeric Contaminants in Recycle Pulp Slurries by Optical Fluorescence and Scanning Electron Microscopy.

1997 ◽  
Vol 3 (S2) ◽  
pp. 1247-1248
Author(s):  
R. M. Fisher ◽  
J. Holbery ◽  
Barbara Reine
Keyword(s):  
Electron Microscopy ◽  
Fine Particles ◽  
Polymeric Materials ◽  
Measuring Instruments ◽  
Paper Machine ◽  
X Ray ◽  
Optical Fluorescence ◽  
Thermal Analysis Techniques ◽  
Physical And Chemical

A major problem now hampering increased recycling of old cardboard containers (OCC), is the presence of significant amounts of polymeric materials such as adhesives, tapes, labels and wax which enter the pulp process stream along with the cardboard and paper that was collected for recycling. Many of these materials contain very fine particles of inorganic fillers and pigments. These various contaminant constituents combine in some, as yet unknown, manner to form an extremely gummy material that deposits on paper machine surfaces and sticks tenaciously (hence the term “Stickies”). The sticky blobs are very difficult to remove and increases machine downtime and maintenance costs as well as causing blemishes on the finished container board product Light optical image analysis, UV fluorescence, FTIR and electron microscopy are being used in consort with particle size measuring instruments, TGS and DSC thermal analysis techniques, FTIR infra-red spectroscopy as well as XRF (x-ray fluorescence spectroscopy ), XPS (x-ray photo emission spectroscopy) and classical contact angle determination methods as part of a broad program to characterize the physical and chemical nature of stickies in pulp slurries with the goal of removing them or alleviating their pronounced tendency to deposit on machinery and paper products.

scholarly journals Chemical and Physical Characterization of Peanut Powder Extracts

2018 ◽  
Vol 10 (4) ◽  
pp. 323
Author(s):  
Luzia Marcia de Melo Silva ◽  
Francisco de Assis Cardoso Almeida ◽  
Francinalva Cordeiro de Sousa ◽  
Deise Souza de Castro ◽  
Inácia dos Santos Moreira ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Ambient Temperature ◽  
Spherical Shape ◽  
Chemical Compounds ◽  
Growth Potential ◽  
Chemical Characteristics ◽  
Peanut Extract ◽  
Physical And Chemical ◽  
Great Growth

The production of lyophilized foods is a market with great growth potential, for providing important preservation characteristics, such as stability at ambient temperature, versatility of the product and preservation of the chemical compounds. Given the functional effects of peanut powder extracts, this study aimed to quantify the bioactive compounds and determine physical and chemical characteristics, comparing samples with and without skin. After obtaining the aqueous peanut extract the samples were frozen at -18 °C for 24 h. The formulated extracts were dried in a benchtop lyophilizer operating at temperature of -55 °C for a period of 48 hours. The powder extracts were disintegrated in a multiprocessor for 30 seconds and the samples were physically and chemically evaluated. The powder extracts were classified as non-hygroscopic, exhibiting poor fluidity and intermediate cohesiveness in samples with skin, and high cohesiveness in samples without skin. The powders showed agglomerated particles, with irregular and non-uniform shape. Potassium was the mineral found in largest amounts, as well as oleic and linoleic fatty acids. The particles of the powders exhibit a spherical shape, showing the presence of amorphous surfaces, in which there is no repetition of geometric forms. The peanut powder extracts are classified as non-hygroscopic, have poor fluidity, intermediate cohesiveness in samples with skin and high cohesiveness in samples without skin.

scholarly journals Preparation, Modification, and Characterization of Alginate Hydrogel with Nano-/Microfibers: A New Perspective for Tissue Engineering

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Bianca Palma Santana ◽  
Fernanda Nedel ◽  
Evandro Piva ◽  
Rodrigo Varella de Carvalho ◽  
Flávio Fernando Demarco ◽  
...  
Keyword(s):  
Cell Viability ◽  
Chemical Properties ◽  
Chemical Characteristics ◽  
X Ray Diffraction ◽  
Alginate Hydrogel ◽  
X Ray ◽  
New Perspective ◽  
Nih 3T3

We aimed to develop an alginate hydrogel (AH) modified with nano-/microfibers of titanium dioxide (nfTD) and hydroxyapatite (nfHY) and evaluated its biological and chemical properties. Nano-/microfibers of nfTD and nfHY were combined with AH, and its chemical properties were evaluated by FTIR spectroscopy, X-ray diffraction, energy dispersive X-Ray analysis, and the cytocompatibility by the WST-1 assay. The results demonstrate that the association of nfTD and nfHY nano-/microfibers to AH did not modified the chemical characteristics of the scaffold and that the association was not cytotoxic. In the first 3 h of culture with NIH/3T3 cells nfHY AH scaffolds showed a slight increase in cell viability when compared to AH alone or associated with nfTD. However, an increase in cell viability was observed in 24 h when nfTD was associated with AH scaffold. In conclusion our study demonstrates that the combination of nfHY and nfTD nano-/microfibers in AH scaffold maintains the chemical characteristics of alginate and that this association is cytocompatible. Additionally the combination of nfHY with AH favored cell viability in a short term, and the addition of nfTD increased cell viability in a long term.

Mineralogy and Physical and Chemical Characteristics of Coal Ash from Yang Zonghai Power Plant

2010 ◽  
Vol 177 ◽  
pp. 497-501
Author(s):  
Feng Rui Zhai ◽  
Zhong Zhou Yi ◽  
Qun Cai ◽  
Huan Bin Song ◽  
Li Li Zhang ◽  
...  
Keyword(s):  
Power Plant ◽  
Particle Diameter ◽  
Coal Ash ◽  
Chemical Characteristics ◽  
Test Results ◽  
X Ray Diffraction ◽  
X Ray ◽  
Physical And Chemical Characteristics ◽  
Coal Ashes ◽  
Physical And Chemical

The modality, physical and chemical characteristics, mineralogy and distribution of particle size of coal ash were studied by modern analytic technology SEM, spectral analysis, X - ray Diffraction (XRD) and laser granularity analyzer. The test results show that the mineralogy of coal ashes is dominated mainly by mullite, quartz and hematite.The coal ash of Yang Zonghai power plant has lower content of calcium oxide and is low calcium ash.At the same time, the losing amount is low to burn.The particle diameter is small and mainly concentrates on the range of 1-40 m.

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