scholarly journals Improving the efficiency of operational control during the expert evaluation of the quality and biosafety of seed material and forage grain

2020 ◽  
Author(s):  
M.V. Arkhipov ◽  
◽  
N.S. Priyatkin ◽  
L.P. Gusakova ◽  
N.N. Potrakhov ◽  
...  
Keyword(s):  
Expert Evaluation ◽  
Operational Control ◽  
Minimum Level ◽  
Preliminary Assessment ◽  
Traditional Methods ◽  
X Ray ◽  
Ripening Period ◽  
Post Harvest ◽  
Seed Material ◽  
High Degree

The aim of this work was to assess the effectiveness of X-ray radiography when evaluating the suitability of batches of grain for sowing or technological purposes, taking into account the possibility to control them during the post-harvest ripening period. X-ray radiography allows solving the problem of choosing batches of grain for different purposes with a minimum level of hidden defects and a high degree of economic suitability for sowing or technological purposes. This technique is of particular value for conducting a preliminary assessment of the quality and biosafety of grain immediately after harvesting when traditional methods are not always applicable.

Anionic and Cationic Redox Processes in β-Li2IrO3 and Their Structural Implications on Electrochemical Cycling in Li-Ion Cell

2019 ◽  
Author(s):  
Paul Pearce ◽  
Gaurav Assat ◽  
Antonella Iadecola ◽  
François Fauth ◽  
Rémi Dedryvère ◽  
...  
Keyword(s):  
Analytical Techniques ◽  
Charge Compensation ◽  
Coupling Mechanism ◽  
Redox Processes ◽  
Positive Electrodes ◽  
X Ray ◽  
Electrochemical Cycling ◽  
Li Ion ◽  
Electrochemical Instability ◽  
High Degree

The recent discovery of anionic redox as a means to increase the energy density of transition metal oxide positive electrodes is now a well established approach in the Li-ion battery field. However, the science behind this new phenomenon pertaining to various Li-rich materials is still debated. Thus, it is of paramount importance to develop a robust set of analytical techniques to address this issue. Herein, we use a suite of synchrotron-based X-ray spectroscopies as well as diffraction techniques to thoroughly characterize the different redox processes taking place in a model Li-rich compound, the tridimentional hyperhoneycomb β-Li2IrO3. We clearly establish that the reversible removal of Li+ from this compound is associated to a previously described reductive coupling mechanism and the formation of the M-(O-O) and M-(O-O)* states. We further show that the respective contributions to these states determine the spectroscopic response for both Ir L3-edge X-ray absorption spectroscopy (XAS) and X-ray photoemissions spectroscopy (XPS). Although the high covalency and the robust tridimentional structure of this compound enable a high degree of reversibile delithiation, we found that pushing the limits of this charge compensation mechanism has significant effects on the local as well as average structure, leading to electrochemical instability over cycling and voltage decay. Overall, this work highlights the practical limits to which anionic redox can be exploited and sheds some light on the nature of the oxidized species formed in certain lithium-rich compounds.<br>

Anionic and Cationic Redox Processes in β-Li2IrO3 and Their Structural Implications on Electrochemical Cycling in Li-Ion Cell

2019 ◽  
Author(s):  
Paul Pearce ◽  
Gaurav Assat ◽  
Antonella Iadecola ◽  
François Fauth ◽  
Rémi Dedryvère ◽  
...  
Keyword(s):  
Analytical Techniques ◽  
Charge Compensation ◽  
Coupling Mechanism ◽  
Redox Processes ◽  
Positive Electrodes ◽  
X Ray ◽  
Electrochemical Cycling ◽  
Li Ion ◽  
Electrochemical Instability ◽  
High Degree

The recent discovery of anionic redox as a means to increase the energy density of transition metal oxide positive electrodes is now a well established approach in the Li-ion battery field. However, the science behind this new phenomenon pertaining to various Li-rich materials is still debated. Thus, it is of paramount importance to develop a robust set of analytical techniques to address this issue. Herein, we use a suite of synchrotron-based X-ray spectroscopies as well as diffraction techniques to thoroughly characterize the different redox processes taking place in a model Li-rich compound, the tridimentional hyperhoneycomb β-Li2IrO3. We clearly establish that the reversible removal of Li+ from this compound is associated to a previously described reductive coupling mechanism and the formation of the M-(O-O) and M-(O-O)* states. We further show that the respective contributions to these states determine the spectroscopic response for both Ir L3-edge X-ray absorption spectroscopy (XAS) and X-ray photoemissions spectroscopy (XPS). Although the high covalency and the robust tridimentional structure of this compound enable a high degree of reversibile delithiation, we found that pushing the limits of this charge compensation mechanism has significant effects on the local as well as average structure, leading to electrochemical instability over cycling and voltage decay. Overall, this work highlights the practical limits to which anionic redox can be exploited and sheds some light on the nature of the oxidized species formed in certain lithium-rich compounds.<br>

Low-temperature route to nanoscale P3N5 hollow spheres

2003 ◽  
Vol 18 (10) ◽  
pp. 2359-2363 ◽  
Author(s):  
Hongzhou Gu ◽  
Yunle Gu ◽  
Zhefeng Li ◽  
Yongcheng Ying ◽  
Yitai Qian
Keyword(s):  
Photoelectron Spectroscopy ◽  
Hollow Spheres ◽  
Molar Ratio ◽  
Visible Absorption ◽  
X Ray ◽  
Transmission Electron ◽  
Influence Of Temperature On ◽  
Wide Gap ◽  
20 Nm ◽  
High Degree

Nanoscale hollow spheres of amorphous phosphorus nitride (P3N5) were synthesized by reacting PCl3 with NaN3 at 150–250 °C. Transmission electron microscope images show that the hollow spheres have a diameter of 150–350 nm, and the thickness of the shell is 20 nm. A very small amount of curly films were also found in the sample prepared at 150 °C. The infrared spectrum indicates a high degree of purity. X-ray photoelectron spectroscopy indicates the presence of P and N, with a molar ratio of 1:1.62 for P:N. Ultraviolet-visible absorption spectroscopy shows an absorption band at 265–315 nm. Under photoluminescent excitation at 230 nm, the P3N5 emits ultraviolet light at 305 nm. With a band gap of 4.28 eV, the products may be a wide gap semiconductor. A possible mechanism and the influence of temperature on the formation of the hollow spheres are also discussed.

ANALYSIS OF THE TOPOGRAPHIC DISTRIBUTION OF THYROID ACTIVITY IN A TELEOST FISH: CARASSIUS CARASSIUS L.

1967 ◽  
Vol 56 (3) ◽  
pp. 533-546 ◽  
Author(s):  
Lars Frisén ◽  
Marianne Frisén
Keyword(s):  
Crucian Carp ◽  
Carassius Carassius ◽  
Caudal Part ◽  
Thyroid Activity ◽  
X Ray ◽  
Lower Jaw ◽  
Thyroid Uptake ◽  
Regression Functions ◽  
Sampling Intervals ◽  
High Degree

ABSTRACT Combined autoradiography and X-ray photography has demonstrated that the tissues of the caudal part of the lower jaw and the pronephric region have a considerably larger uptake of radioiodine than other tissues in the immature crucian carp, Carassius carassius L. It is known from previous studies that thyroid follicles occur in these regions. The pronephric thyroid differs from the mandibular thyroid with regard to radioiodine turnover. On an average, the pronephric thyroid has a larger uptake than the lower jaw thyroid. The relative uptakes varied considerably in the population investigated. The ratio mandibular uptake/total thyroid uptake has been determined at several sampling intervals. The means of these ratios show no significant trend with time, a finding which strongly supports the view that the two regions are variably sized parts of a physiologically homogeneous thyroid gland. The analysis is based on a mathematical model of iodine turnover. The method of comparing complex regression functions (sums of exponential functions) should be widely applicable. The correlation between the radioiodine content of either region and total thyroid content is low. Thus, it is necessary to study simultaneously all follicle-carrying tissues in fish with more than one aggregation of thyroid elements. The net radioiodine turnover in the crucian carp indicates a comparatively high degree of thyroid activity and considerably higher than that reported for C. auratus L. This phenomenon is discussed.

scholarly journals Defects of copper patina / Vady mìdìných patin

2015 ◽  
Vol 59 (3) ◽  
pp. 87-90 ◽  
Author(s):  
J. Stoulil ◽  
P. Šedá ◽  
M. Anisová ◽  
Z. Fencl ◽  
P. Novák ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Image Analysis ◽  
Compact Surface ◽  
Historical Buildings ◽  
X Ray Diffraction ◽  
X Ray ◽  
Destructive Analysis ◽  
High Degree ◽  
Scanning Electron

Abstract The paper is focused on analyses of dark copper patina defects that were formed on one sheet under the same conditions. Roofs of ten historical buildings were studied by image analysis and samples of two roofs were subjected to more detailed destructive analysis. These samples were studied by means of scanning electron microscopy with energy dispersive X-ray spectroscopy, X-ray diffraction and infrared spectroscopy. Both types of patina are composed of brochantite. Green patinas consisted of a pure brochantite and they had a fl at and compact surface. Conversely, black patina contained a high degree of impurities (ammonia cations, nitrates, silicates) and the surface was rough. The proportion of dark patina was higher in south and east facing surfaces, where washing by rainfall is more difficult.

scholarly journals Intramural Duodenal Hematoma In 2-year Old Child

2018 ◽  
Vol 9 (3) ◽  
pp. 18
Author(s):  
Dayanand Hota ◽  
Kamal Nain Rattan ◽  
Ahmad Khursheed ◽  
Manish Swami ◽  
Harish Bhardwaj
Keyword(s):  
Duodenal Obstruction ◽  
Intramural Hematoma ◽  
Abdominal Distension ◽  
Rare Entity ◽  
Diagnostic Dilemma ◽  
X Ray ◽  
Duodenal Hematoma ◽  
High Degree ◽  
High Intestinal Obstruction ◽  
Head Of Pancreas

Background: Intramural hematoma of the duodenum is a rare cause of acquired duodenal obstruction. It is often a diagnostic dilemma and a high degree of suspicion is required to make an early and accurate diagnosis in children. Case Report: A 2-year-old child presented with bilious vomiting and abdominal distension. X-ray abdomen showed high intestinal obstruction. Ultrasound and CT scan abdomen gave suspicion of pancreatic pseudo-cyst near head of pancreas. At surgery, an intramural hematoma of the duodenum was found and drained. Conclusion: Intramural duodenal hematoma is a rare entity especially in children and should be considered in differential diagnosis of acquired duodenal obstruction.

scholarly journals Water–DNA interactions as studied by X–ray and neutron fibre diffraction

2004 ◽  
Vol 359 (1448) ◽  
pp. 1237-1248 ◽  
Author(s):  
Watson Fuller ◽  
Trevor Forsyth ◽  
Arumugam Mahendrasingam
Keyword(s):  
Structural Information ◽  
Double Helix ◽  
Water Environment ◽  
Structural Features ◽  
Molecular Conformations ◽  
X Ray ◽  
Biochemical Processes ◽  
Fibre Diffraction ◽  
Dna Double Helix ◽  
High Degree

X–ray fibre–diffraction studies indicate a high degree of stereochemical specificity in interactions between water and the DNA double helix. Evidence for this comes from data that show that the molecular conformations assumed by DNA in fibres are highly reproducible and that the hydration–driven transitions between these conformations are fully reversible. These conformational transitions are induced by varying the relative humidity of the fibre environment and hence its water content. Further evidence for stereochemical specificity comes from the observed dependence of the conformation assumed on the ionic content of the fibre and the nucleotide sequence of the DNA. For some transitions, information on stereochemical pathways has come from real–time X–ray fibre diffraction using synchrotron radiation; information on the location of water with respect to the double helix for a number of DNA conformations has come from neutron fibre diffraction. This structural information from fibre–diffraction studies of DNA is complemented by information from X–ray single–crystal studies of oligonucleotides. If the biochemical processes involving DNA have evolved to exploit the structural features observed in DNA fibres and oligonucleotide single crystals, the challenges in developing alternatives to a water environment can be expected to be very severe.

The amino acid sequence of yeast phosphoglycerate mutase

1982 ◽  
Vol 215 (1198) ◽  
pp. 19-44 ◽  
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Proteolytic Enzymes ◽  
Phosphoglycerate Mutase ◽  
Crystallographic Structure ◽  
X Ray ◽  
C Terminus ◽  
Detailed Interpretation ◽  
High Degree

The complete amino acid sequence of yeast phosphoglycerate mutase comprising 241 residues has been determined. The sequence was deduced from the two cyanogen bromide fragments, and from the peptides derived from these fragments after digestion by a number of proteolytic enzymes. Determination of this sequence now allows a detailed interpretation of the existing high-resolution X-ray crystallographic structure. A comparison of the sequence reported here with the sequences of peptides from phosphoglycerate mutases from other species, and with the sequence of erythrocyte diphosphoglycerate mutase, indicates that these enzymes have a high degree of structural homology. Autolysis of phosphoglycerate mutase by yeast extracts leads to the complete loss of mutase activity, and the formation of electrophoretically distinguishable forms (R. Sasaki, E. Sugimoto & H. Chiba, Archs Biochem. Biophys. 115, 53-61 (1966)). It is apparent from the amino acid sequence that these changes are due to the loss of an 8─12 residue peptide from the C-terminus.

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