Effect of pH on the detailed chemical nature and metal‐carbonate species in as synthesized zirconia alumina composites

2020 ◽  
Vol 103 (11) ◽  
pp. 6615-6629
Author(s):  
Ruhi H. Pathan ◽  
Chetan K. Modi ◽  
Arun Basrur
Keyword(s):  
Chemical Nature ◽  
Effect Of Ph ◽  
Metal Carbonate ◽  
Alumina Composites ◽  
Carbonate Species ◽  
Detailed Chemical

scholarly journals The chemical nature of the young 120-Myr-old nearby Pisces–Eridanus stellar stream flowing through the Galactic disc

2020 ◽  
Vol 496 (2) ◽  
pp. 2422-2435
Author(s):  
Keith Hawkins ◽  
Madeline Lucey ◽  
Jason Curtis
Keyword(s):  
Chemical Nature ◽  
Rotation Period ◽  
Major Axis ◽  
Abundance Distribution ◽  
Galactic Disc ◽  
Kinematic Data ◽  
Period Distribution ◽  
Solar Metallicity ◽  
Detailed Chemical

ABSTRACT Recently, a new cylindrical-shaped stream of stars up to 700 pc long was discovered hiding in the Galactic disc using kinematic data enabled by the Gaia mission. This stream of stars, dubbed Pisces–Eridanus (Psc–Eri), was initially thought to be as old as 1 Gyr, yet its stars shared a rotation period distribution consistent with a population that was 120 Myr old. Here, we explore the detailed chemical nature of this stellar stream. We carried out high-resolution spectroscopic follow-up of 42 Psc–Eri stars using McDonald Observatory and combined these data with information for 40 members observed with the low-resolution LAMOST spectroscopic survey. Together, these data enabled us to measure the abundance distribution of light/odd-Z (Li, Na, Al, Sc, V), α (Mg, Si, Ca, Ti), Fe-peak (Cr, Mn, Fe, Co, Ni, Zn), and neutron capture (Sr, Y, Zr, Ba, La, Nd, Eu) elements along the Psc–Eri stream. We find that the stream is (1) near-solar metallicity with [Fe/H] = –0.03 dex and (2) has a metallicity spread of 0.07 dex (or 0.04 dex when outliers are excluded). We also find that (3) the abundance of Li indicates that Psc–Eri is ∼120 Myr old, consistent with its gyrochronology age. Additionally, Psc–Eri has (4) [X/Fe] abundance spreads that are just larger than the typical uncertainty in most elements, (5) it is a cylindrical-like system whose outer edges rotate about the centre, and (6) no significant abundance gradients along its major axis except a potentially weak gradient in [Si/Fe]. These results show that Psc–Eri is a uniquely close young chemically interesting laboratory for testing our understanding of star and planet formation.

scholarly journals Characterization of sirodesmins isolated from the phytopathogenic fungus Leptosphaeria maculans

2012 ◽  
Vol 77 (10) ◽  
pp. 1363-1379 ◽  
Author(s):  
Petar Mitrovic ◽  
Dejan Orcic ◽  
Zvonimir Sakac ◽  
Ana Marjanovic-Jeromela ◽  
Nada Grahovac ◽  
...  
Keyword(s):  
High Performance ◽  
Chemical Nature ◽  
Leptosphaeria Maculans ◽  
Stem Canker ◽  
Phytopathogenic Fungi ◽  
Phytopathogenic Fungus ◽  
Brassica Napus L ◽  
Layer Chromatography ◽  
Detailed Chemical

Pathogenicity of phytopathogenic fungi is accociated with phytotoxins, especially with their chemical nature and quantity. Sirodesmins are phytotoxins from epipolythiodioxopiperazines group, produced by fungi Leptosphaeria maculans that is a cause of blackleg and stem canker in oilseed rape (Brassica napus L.). The aim of this work was to obtain a detailed chemical profile of sirodesmins in five fungal isolates (four from Vojvodina and one from UK). Sirodesmins showing different phytotoxicity on treated cotyledons of cv. Quinta were separated and detected by thin layer chromatography in all analysed isolates (L.m, C-3, St-5, S-11) except K-113, which did not contain sirodesmin congeners nor exhibited activity. By use of high performance liquid chromatography coupled with tandem mass spectrometer, it was possible to identify total of 10 sirodesmins, together with their precursor - phomamide. It was found that dominant epipolythiodioxopiperazines of investigated L. maculans isolates were sirodesmin PL, sirodesmin C, and their deacetylated derivatives.

scholarly journals Studies on Metal Carbonate Equilibria. 22. A Coulometric Study of the Uranium(VI)--Carbonate System, the Composition of the Mixed Hydroxide Carbonate Species.

1991 ◽  
Vol 45 ◽  
pp. 122-128 ◽  
Author(s):  
Ingmar Grenthe ◽  
Bo Lagerman ◽  
R. G. Hazell ◽  
Fredrik Lindgren ◽  
Michael Sjöström ◽  
...  
Keyword(s):  
Carbonate System ◽  
Metal Carbonate ◽  
Carbonate Equilibria ◽  
Carbonate Species

REACTION OF CO2 WITH MgO(100) SURFACES

1999 ◽  
Vol 06 (06) ◽  
pp. 1237-1245 ◽  
Author(s):  
X. CARRIER ◽  
C. S. DOYLE ◽  
T. KENDELEWICZ ◽  
G. E. BROWN
Keyword(s):  
High Pressures ◽  
Chemical Nature ◽  
Photoemission Spectroscopy ◽  
Threshold Pressure ◽  
Stage Model ◽  
Equilibrium Thermodynamic ◽  
Two Stage ◽  
Nexafs Spectroscopy ◽  
Defect Sites ◽  
Carbonate Species

Synchrotron-based photoemission spectroscopy (C 1s and O 1s regions) as well as C K-edge NEXAFS spectroscopy have been used to investigate the formation of carbonate species on the surface of MgO(100) after exposure to CO 2 at pressures ranging from 0.8 to 260 Torr. These results are tentatively compared with a two-stage model for the reaction of H 2 O on MgO(100) [Liu et al., Surf. Sci.412/413, 287 (1998)]. At p( CO 2) values below a threshold pressure (predicted to be in the range of 10-9–10-6 Torr), the reaction of CO 2 with MgO(100) is fairly limited and CO 2 is assumed to react with defect sites only. At pressures ≥ 0.8 Torr, CO 2 reacts with terrace sites, resulting in extensive formation of [Formula: see text] groups on the MgO(100) surface. However, carbonate formed at "high" pressures ( P CO 2 ≥ 0.8 Torr) begins to desorb at the low pressure of the analysis chamber (10-11 Torr), which is consistent with equilibrium thermodynamic predictions of the "threshold" pressure for the reaction MgO + CO 2= MgCO 3. Results from polarization-dependent C K-edge NEXAFS spectroscopy suggest that the carbonate molecules formed on the surface are structurally disordered. The chemical nature of adventitious carbon formed on the MgO(100) surface was also invesgtigated, and is clearly different from [Formula: see text].

Release of Neurosecretion in the Crayfish Sinus Gland

1968 ◽  
Vol 26 ◽  
pp. 150-151
Author(s):  
Richard R. Shivers
Keyword(s):  
Chemical Nature ◽  
Storage Site ◽  
Neurosecretory Granules ◽  
Sinus Gland ◽  
Diameter Class ◽  
Dense Membrane ◽  
Neurohemal Organ ◽  
Dense Vesicles

The sinus gland is a neurohemal organ located in the crayfish eyestalk and represents a storage site for neurohormones prior to their release into the circulation. The sinus gland contains 3 classes of dense, membrane-limited granules: 1) granules measuring less than 1000 Å in diameter, 2) granules measuring 1100-1400 Å in diameter, and 3) granules measuring 1500-2000 Å in diameter. Class 3 granules are the most electron-dense of the granules found in the sinus gland, while class 2 granules are the most abundant. Generally, all granules appear to undergo similar changes during release.Release of neurosecretory granules may be initiated by a preliminary fragmentation of the “parent granule” into smaller, less dense vesicles which measure about 350 Å in diameter (V, Figs. 1-3). A decrease in density of the granules prior to their fragmentation has been observed and may reflect a change in the chemical nature of the granule contents.

Freeze-fracture cytochemistry: A goal set by Russell Steere in 1957

1993 ◽  
Vol 51 ◽  
pp. 60-61
Author(s):  
Nicholas J Severs
Keyword(s):  
Chemical Nature ◽  
Biological Systems ◽  
Freeze Fracture ◽  
Structural Components ◽  
Major Goal ◽  
Membrane Biology ◽  
Routine Application ◽  
The Future ◽  
Freeze Etching

In his pioneering demonstration of the potential of freeze-etching in biological systems, Russell Steere assessed the future promise and limitations of the technique with remarkable foresight. Item 2 in his list of inherent difficulties as they then stood stated “The chemical nature of the objects seen in the replica cannot be determined”. This defined a major goal for practitioners of freeze-fracture which, for more than a decade, seemed unattainable. It was not until the introduction of the label-fracture-etch technique in the early 1970s that the mould was broken, and not until the following decade that the full scope of modern freeze-fracture cytochemistry took shape. The culmination of these developments in the 1990s now equips the researcher with a set of effective techniques for routine application in cell and membrane biology.Freeze-fracture cytochemical techniques are all designed to provide information on the chemical nature of structural components revealed by freeze-fracture, but differ in how this is achieved, in precisely what type of information is obtained, and in which types of specimen can be studied.

Cell parameters refinements showing an influence of the chemical nature of the grain surface on the crystalline characteristics of fine grained powders

1998 ◽  
Vol 08 (PR5) ◽  
pp. Pr5-85-Pr5-89
Author(s):  
P. Sarrazin ◽  
F. Bernard ◽  
G. Calvarin ◽  
J. C. Niepce ◽  
B. Thierry
Keyword(s):  
Chemical Nature ◽  
Cell Parameters ◽  
Fine Grained ◽  
Grain Surface
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