The Thermal Decomposition of Thorium Oxalate

1951 ◽  
Vol 4 (4) ◽  
pp. 644 ◽  
Author(s):  
R Beckett ◽  
ME Winfield
Keyword(s):  
Electrical Conductivity ◽  
Thermal Decomposition ◽  
Weight Loss ◽  
Weight Loss Curve ◽  
Large Area ◽  
Small Temperature ◽  
X Ray ◽  
Almost All ◽  
Thorium Oxalate ◽  
Composition Of Products

The thermal decomposition of hydrated thorium oxalate was followed by determining weight loss, change in electrical conductivity, and chemical composition of products. At temperatures below 200�C. the weight-loss curve indicated the existence of a tri- and a dihydrate and possibly a pentahydrate of thorium oxalate as stages m the dehydration. At higher temperatures dehydration was accompanied by loss of CO and CO2. Almost all the (C2O4)= decomposed sharply over a small temperature range near 300�C. Although some carbonate was formed, it did not exceed a concentration of 0.076 mole per mole of total thorium. According to chemical analysis the residue after heating at 350�C. was ThO2 with a trace of carbonate and water. X-ray analysis, however, showed it to be a mixture of ThO2, and a second substance whose identity is unknown. In the electron microscope the hydrated oxalate and the thoria produced from it were little different in appearance. Both appeared as relic crystals which were square prisms about l μ across and 0.2 μ thick, with a characteristic central aperture which exposed a large area of surface.

Complexing Ability of Some 2-Spirothiazolid-4-one Derivatives

1994 ◽  
Vol 49 (4) ◽  
pp. 551-555
Author(s):  
Mohamed A. El-Gahami ◽  
Maher F. El-Zohry
Keyword(s):  
Electrical Conductivity ◽  
Thermal Decomposition ◽  
Metal Ions ◽  
Chelating Ligands ◽  
Bidentate Ligands ◽  
Conductivity Measurements ◽  
X Ray Diffraction ◽  
X Ray ◽  
H Nmr ◽  
Conducting Materials

The complexes of some 2-spirothiazolid-4-one derivatives have been prepared with Cu(II), N i(II), C o(II) and Cd(II) salts. The complexes all have a metal to ligand ratios of 1:1 or 1:2 and are all believed to have tetrahedral structures with chelating ligands. Their structures are suggested on the basis of analysis, X-ray diffraction techniques, spectral (UV-VIS, IR, 1H NMR), and thermal decomposition as well as conductivity measurements. The ligands are coordinated to the metal ions as monovalent bidentate ligands through the OCO groups. Electrical conductivity studies indicated that these complexes have activation energies in the range of semi-conducting materials. It is observed that some of the complexes are m ore potent as bacteriostatic agents than the free ligands.

Studies on Bis-hydrazine Complexes of Metal Propionates and Mixed Metal Propionates

1994 ◽  
Vol 49 (7) ◽  
pp. 950-954 ◽  
Author(s):  
B. N. Sivasankar ◽  
S. Govindarajan
Keyword(s):  
Thermal Decomposition ◽  
Weight Loss ◽  
Ir Spectra ◽  
Metal Complexes ◽  
Metal Oxides ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mixed Metal ◽  
Mixed Metal Complexes ◽  
Final Residue

Abstract Metal propionate hydrazinates, M(CH3Ch2COO)2(N2H4)2 where M = Mn, Co, Ni, Zn or Cd, and mixed metal propionate hydrazinates with cobalt, M1/3Co2/3(CH3CH2COO)2(N2H4)2 where M = Mg, Mn, Ni, Zn or Cd, have been prepared and characterized by analytical, magnetic, spectral, thermal and X-ray diffraction studies. The thermal decomposition of the former complexes yields the metal oxides while the latter mixed metal complexes give the corresponding metal cobaltites as the final residue. Formation of metal cobaltites has been confirmed by TG weight loss, IR spectra and X-ray diffraction.

Polytypism of heterogenite

1973 ◽  
Vol 39 (302) ◽  
pp. 152-157 ◽  
Author(s):  
M. Deliens ◽  
H. Goethals
Keyword(s):  
Crystal Structure ◽  
Weight Loss ◽  
Microprobe Analysis ◽  
Weight Loss Curve ◽  
Cell Content ◽  
New Variety ◽  
X Ray ◽  
Cell Dimensions ◽  
Degree Of Anisotropy ◽  
Main Index

SummaryA new variety of heterogenite was found in samples from Mindigi, Shaba, Zaïre. Photometric reflectance varies from 0·235 to 0·165 at λ 5890 Å in air. The bireflectance is 0·070, the degree of anisotropy is 0·7 and the main index in air is 2·7. A thermal weight-loss curve and a microprobe analysis are given and discussed, indicating the formula (Co,Ni) O.OH.The new variety, referred to as heterogenite-H, is hexagonal with cell dimensions a 2·85, c 8·80, space group P63/mmc and cell-content 2 [(Co, Ni)O.OH)]. Indexed X-ray powder data are given. A crystal structure is suggested based on CoO.OH octahedra layers and indicating a polytypic relation between heterogenite-H, the 2H form, and normal heterogenite, the 3R form.

scholarly journals Chlorination of antimony and its volatilization treatment of waste antimony-uranium composite oxide catalyst

2011 ◽  
Vol 1 (1) ◽  
pp. 97-100
Author(s):  
K. Sawada ◽  
Y. Enokida
Keyword(s):  
Weight Loss ◽  
Nitric Acid ◽  
Acid Solution ◽  
Uranium Oxide ◽  
Oxide Catalyst ◽  
X Ray Diffraction ◽  
Composite Oxide ◽  
X Ray ◽  
Almost All ◽  
Oxide Sample

Abstract For the waste antimony-uranium composite oxide catalyst, the chlorination of antimony and its volatilization treatment were proposed, and evaluated using hydrogen chloride gas at 873–1173 K. During the treatment, the weight loss of the composite oxide sample, which resulted from the volatilization of antimony, was confirmed. An X-ray diffraction analysis showed that uranium oxide, U3O8, was formed during the reaction. After the treatment at 1173 K for 1 h, almost all the uranium contained in the waste catalyst was dissolved by a 3 M nitric acid solution at 353 K within 10 min, although that of the non-treated catalyst was less than 0.1%. It was found that the chlorination and volatilization treatment was effective to separate antimony from the composite oxide catalyst and change uranium into its removable form.

Dickite from sandstones in northern England and North Wales

1957 ◽  
Vol 31 (236) ◽  
pp. 381-391 ◽  
Author(s):  
Frank Smithson ◽  
George Brown
Keyword(s):  
Thermal Analysis ◽  
Weight Loss ◽  
Differential Thermal Analysis ◽  
Chemical Analysis ◽  
Middle Jurassic ◽  
Weight Loss Curve ◽  
Lower Carboniferous ◽  
X Ray ◽  
Powder Method ◽  
North Wales

SummaryThe occurrence of dickite as a rock-forming mineral in sandstones of the Lower Carboniferous Series, the Millstone Grit, and the Middle Jurassic has been reported previously by the authors. In view of the paucity of data on this mineral, six samples were purified and examined optically, by staining tests, and by the X-ray powder method. In addition, a chemical analysis, a differential thermal analysis, and a thermal weight-loss curve were made on the purest sample. The investigations confirm the identity of the material.

Crystallinity and Thermal Decomposition of Dialdehyde Celluloses from Bacterial Cellulose

2007 ◽  
Vol 330-332 ◽  
pp. 1289-1292 ◽  
Author(s):  
Yu Hong Feng ◽  
Jia Cheng Li ◽  
Qiang Lin ◽  
Xi Bin Wang ◽  
Zhou Xin Wu ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Weight Loss ◽  
Bacterial Cellulose ◽  
Sodium Periodate ◽  
Rapid Weight Loss ◽  
Crystallinity Degree ◽  
X Ray ◽  
Dialdehyde Cellulose ◽  
Lower Temperature Range ◽  
Lower Temperature

A series of dialdehyde cellulose samples with varied aldehyde content were prepared by oxidation of bacterial cellulose with sodium periodate. The X-ray diffractometry profile showed that the crystallinity degree of bacterial cellulose was 66%, but that of the dialdehyde cellulose (containing 12% aldehyde ) was 56%. Thermal decomposition of these dialdehyde cellulose samples and bacterial cellulose were studied by thermogravimetry. The decomposition of bacterial cellulose in nitrogen started at 230 and rapid weight loss occurred between 300-400. The introduction of dialdehyde group to bacterial cellulose resulted in significant shifts of decomposition to lower temperature range. The decomposition of dialdehyde cellulose (12% aldehyde ) started at 180 and rapid weight loss between 200-350. The temperature of rapidest weight loss shifted from 340 of bacterial cellulose to 290 of the dialdehyde cellulose(12% aldehyde).

Removing Substrate Background in TEM Microanalysis

1974 ◽  
Vol 32 ◽  
pp. 568-569
Author(s):  
John C. Russ ◽  
Nicholas C. Barbi
Keyword(s):  
Electrical Conductivity ◽  
Rapid Growth ◽  
Organic Film ◽  
Absolute Concentration ◽  
Background Signal ◽  
X Ray ◽  
Elemental Concentrations ◽  
Transmission Electron ◽  
Electron Microscopes ◽  
The Continuum

The rapid growth of interest in attaching energy-dispersive x-ray analysis systems to transmission electron microscopes has centered largely on microanalysis of biological specimens. These are frequently either embedded in plastic or supported by an organic film, which is of great importance as regards stability under the beam since it provides thermal and electrical conductivity from the specimen to the grid.Unfortunately, the supporting medium also produces continuum x-radiation or Bremsstrahlung, which is added to the x-ray spectrum from the sample. It is not difficult to separate the characteristic peaks from the elements in the specimen from the total continuum background, but sometimes it is also necessary to separate the continuum due to the sample from that due to the support. For instance, it is possible to compute relative elemental concentrations in the sample, without standards, based on the relative net characteristic elemental intensities without regard to background; but to calculate absolute concentration, it is necessary to use the background signal itself as a measure of the total excited specimen mass.

Analytical Electron Microscopy Study of Second-Phase Particles in 7075 and 7475 Aluminum Alloys

1985 ◽  
Vol 43 ◽  
pp. 348-349
Author(s):  
M. Raghavan ◽  
J. Y. Koo ◽  
J. W. Steeds ◽  
B. K. Park
Keyword(s):  
Aluminum Alloys ◽  
Silicon Oxide ◽  
Analytical Electron Microscopy ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Partial Substitution ◽  
Second Phase ◽  
X Ray ◽  
Second Phase Particles ◽  
Almost All

X-ray microanalysis and Convergent Beam Electron Diffraction (CBD) studies were conducted to characterize the second phase particles in two commercial aluminum alloys -- 7075 and 7475. The second phase particles studied were large (approximately 2-5μm) constituent phases and relatively fine ( ∼ 0.05-1μn) dispersoid particles, Figures 1A and B. Based on the crystal structure and chemical composition analyses, the constituent phases found in these alloys were identified to be Al7Cu2Fe, (Al,Cu)6(Fe,Cu), α-Al12Fe3Si, Mg2Si, amorphous silicon oxide and the modified 6Fe compounds, in decreasing order of abundance. The results of quantitative X-ray microanalysis of all the constituent phases are listed in Table I. The data show that, in almost all the phases, partial substitution of alloying elements occurred resulting in small deviations from the published stoichiometric compositions of the binary and ternary compounds.

scholarly journals Estimation of bulk permittivity of the Moon’s surface using Lunar Radar Sounder on-board Selenological and Engineering Explorer

2020 ◽  
Vol 72 (1) ◽  
Author(s):  
Keigo Hongo ◽  
Hiroaki Toh ◽  
Atsushi Kumamoto
Keyword(s):  
Electrical Conductivity ◽  
Physical Properties ◽  
Titanium Content ◽  
Spectroscopic Observation ◽  
Lunar Rock ◽  
Almost All ◽  
Mare Serenitatis ◽  
Radar Sounder ◽  
Lunar Maria ◽  
Regolith Layer

Abstract Site-dependent bulk permittivities of the lunar uppermost media with thicknesses of tens to hundreds meters were estimated based on the data from Lunar Radar Sounder onboard the Selenological and Engineering Explorer (SELENE). It succeeded in sounding almost all over the Moon’s surface in a frequency range around 5 MHz to detect subsurface reflectors beneath several lunar maria. However, it is necessary to estimate the permittivity of the surface regolith of the Moon in order to determine the actual depths to those reflectors instead of apparent depths assuming a speed of light in the vacuum. In this study, we determined site-dependent bulk permittivities by two-layer models consisting of a surface regolith layer over a half-space with uniform, but different physical properties from the layer above. Those models consider the electrical conductivity as well as the permittivity, whose trade-off was resolved by utilizing the correlation between iron–titanium content and measured physical properties of lunar rock samples. Distribution of the iron–titanium content on the Moon’s surface had already been derived by spectroscopic observation from SELENE as well. Four lunar maria, Mare Serenitatis, Oceanus Procellarum, Mare Imbrium, and Mare Crisium, were selected as regions of evident reflectors, where we estimated the following four physical properties of each layer, i.e., bulk permittivity, porosity, loss tangent and electrical conductivity to conclude the actual depths of the reflectors are approximately 200 m on average. The bulk permittivity ranges from 2.96 at Mare Imbrium to 6.37 at Oceanus Procellarum, whereas the porosity takes the values between 1.8 and 41.1% in the respective maria. It was found that although the bulk permittivity of the four lunar maria differs from a mare to a mare, it shows a good correlation with their composition, viz., their iron–titanium content.

scholarly journals Thermoelectric Generator Using Polyaniline-Coated Sb2Se3/β-Cu2Se Flexible Thermoelectric Films

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1518
Author(s):  
Minsu Kim ◽  
Dabin Park ◽  
Jooheon Kim
Keyword(s):  
Electron Microscopy ◽  
Electrical Conductivity ◽  
Field Emission ◽  
Photoelectron Spectroscopy ◽  
Thermoelectric Generator ◽  
Hydrothermal Reaction ◽  
Water Evaporation ◽  
Pani Film ◽  
Portable Devices ◽  
X Ray

Herein, Sb2Se3 and β-Cu2Se nanowires are synthesized via hydrothermal reaction and water evaporation-induced self-assembly methods, respectively. The successful syntheses and morphologies of the Sb2Se3 and β-Cu2Se nanowires are confirmed via X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, field emission scanning electron microscopy (FE-SEM), and field emission transmission electron microscopy (FE-TEM). Sb2Se3 materials have low electrical conductivity which limits application to the thermoelectric generator. To improve the electrical conductivity of the Sb2Se3 and β-Cu2Se nanowires, polyaniline (PANI) is coated onto the surface and confirmed via Fourier-transform infrared spectroscopy (FT-IR), FE-TEM, and XPS analysis. After coating PANI, the electrical conductivities of Sb2Se3/β-Cu2Se/PANI composites were increased. The thermoelectric performance of the flexible Sb2Se3/β-Cu2Se/PANI films is then measured, and the 70%-Sb2Se3/30%-β-Cu2Se/PANI film is shown to provide the highest power factor of 181.61 μW/m·K2 at 473 K. In addition, a thermoelectric generator consisting of five legs of the 70%-Sb2Se3/30%-β-Cu2Se/PANI film is constructed and shown to provide an open-circuit voltage of 7.9 mV and an output power of 80.1 nW at ΔT = 30 K. This study demonstrates that the combination of inorganic thermoelectric materials and flexible polymers can generate power in wearable or portable devices.

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