Manipulating the Structure and Morphology of Cobalt-Boron Nanoparticles through a Chemical Approach

2013 ◽  
Vol 829 ◽  
pp. 762-766 ◽  
Author(s):  
Hooman Sabarou ◽  
Abolghasem Ataie
Keyword(s):  
Growth Process ◽  
Ph Value ◽  
Amorphous Structure ◽  
Detailed Characterization ◽  
Synthesis Mechanism ◽  
Subsequent Formation ◽  
Structure And Morphology ◽  
Morphology And Structure ◽  
Structure Phase

Cobalt-boron nanoparticles have been synthesized by a chemical reaction between NaBH4 and CoCl2.6H2O through manipulating pH value of the reaction mixture. The morphology, structure, phase composition, and thermal behavior have been examined via FESEM, TEM, XRD, EDS, and DSC techniques, respectively. It is demonstrated that the morphology and structure of ultimate nanoparticles completely depends on the pH value of reaction mixture. While the neutral pH value favors the smallest nanoparticles with a mean particle size of 50 nm and complete amorphous structure, the acidic condition promotes the growth process and the crystal structure. Furthermore, these nanoparticles transform into cobalt nanocrystallites after heated at 600°C, and retained the discrepancies in the morphology and the structure of the parent cobalt-boron nanoparticles. A detailed characterization of the nanoparticulates, discussions on the synthesis mechanism, and subsequent formation transformation have been provided.

Isolation and Characterization of a Strain of Acidithiobacillus ferrooxidans

2013 ◽  
Vol 777 ◽  
pp. 242-246
Author(s):  
Ju Fang Xiao ◽  
Song Yan Qin ◽  
Peng Huang ◽  
Li Na Guo ◽  
Yi Chun Chen
Keyword(s):  
Acidithiobacillus Ferrooxidans ◽  
Oxidation Rate ◽  
Growth Process ◽  
Ph Value ◽  
Exponential Growth Phase ◽  
Sequencing Analysis ◽  
Isolation And Characterization ◽  
Potential Alternative ◽  
Acid Waste

An acidophilic strain was isolated from drainage in Shanxi coal mine, after 16SrDNA amplification and sequencing analysis, it was identified to be Acidithiobacillus ferrooxidans. The ferrous ion oxidation rate of At.f and pH value were studied during its growth, the results showed that, the strain entering into the exponential growth phase needed about 30 hours, and the oxidation rate was more than 99% after 60 hours. The pH value increased from 2.08 to 2.64 at first 30 hours and then decreased to 2.0, and finally maintained at 2.0 in the whole growth process. The isolated strain provided a potential alternative method to handle the steel-picking sulfuric acid waste liquor.

scholarly journals Characterization of Crystalline Structure and Morphology of Ga2O3 Thin Film Grown by MOCVD Technique

2016 ◽  
Vol 721 ◽  
pp. 253-257
Author(s):  
Alvars Kjapsna ◽  
Lauris Dimitrocenko ◽  
Ivars Tale ◽  
Anatoly Trukhin ◽  
Reinis Ignatans ◽  
...  
Keyword(s):  
Thin Film ◽  
Gallium Oxide ◽  
Growth Process ◽  
Oxygen Vacancies ◽  
Oxide Thin Film ◽  
Structure And Morphology ◽  
Carrier Gases ◽  
Compositional Properties ◽  
Mocvd Technique

Growth of gallium oxide thin film was realized with MOCVD on (0001) sapphire substrate. Structural and compositional properties of thin film were studied employing trimethylgallium and water as precursors, carrier gases were H2 and N2. Obtained film is polycrystalline and predominantly consisted of (201) oriented β-Ga2O3. Sample exhibited blue luminescence which is attributed to oxygen vacancies. H2 gas proved to have beneficial effect on film quality and overall growth process.

Intramolecular Proton Transfer in the Isomerization of Hydroxyacetone: A Detailed Characterization Based on Reaction Force Analysis and the Bond Fragility Spectrum

2020 ◽  
Author(s):  
Wallace Derricotte ◽  
Huiet Joseph
Keyword(s):  
Chemical Potential ◽  
Reaction Force ◽  
Intramolecular Proton Transfer ◽  
Intermediate Energy ◽  
Force Analysis ◽  
Activation Energy Barrier ◽  
Detailed Characterization ◽  
Proton Transfers ◽  
Reaction Force Constant

The mechanism of isomerization of hydroxyacetone to 2-hydroxypropanal is studied within the framework of reaction force analysis at the M06-2X/6-311++G(d,p) level of theory. Three unique pathways are considered: (i) a step-wise mechanism that proceeds through formation of the Z-isomer of their shared enediol intermediate, (ii) a step-wise mechanism that forms the E-isomer of the enediol, and (iii) a concerted pathway that bypasses the enediol intermediate. Energy calculations show that the concerted pathway has the lowest activation energy barrier at 45.7 kcal mol<sup>-1</sup>. The reaction force, chemical potential, and reaction electronic flux are calculated for each reaction to characterize electronic changes throughout the mechanism. The reaction force constant is calculated in order to investigate the synchronous/asynchronous nature of the concerted intramolecular proton transfers involved. Additional characterization of synchronicity is provided by calculating the bond fragility spectrum for each mechanism.

DETAILED CHARACTERIZATION OF EUROPA'S RIDGE MORPHOLOGY

2016 ◽  
Author(s):  
Janelle A.F. Heitmeier ◽  
◽  
Emily S. Martin ◽  
Jordan M. Bretzfelder ◽  
D. Alex Patthoff ◽  
...  
Keyword(s):  
Detailed Characterization

The Problem of Divine Hiddenness

2018 ◽  
Author(s):  
Michael C. Rea
Keyword(s):  
Problem Of Evil ◽  
Philosophical Discussion ◽  
Detailed Characterization ◽  
The Past ◽  
Divine Hiddenness ◽  
The Problem Of Evil ◽  
The Relationship

This chapter provides a detailed characterization of the various meanings of the term “divine hiddenness,” carefully and rigorously articulates the version of the problem of divine hiddenness that has dominated contemporary philosophical discussion for the past twenty-five years, and then explains the relationship between that problem and the problem of evil.

Acid-Sensing Ion Channels

2020 ◽  
Author(s):  
Stefan Gründer
Keyword(s):  
Nervous System ◽  
Ion Channels ◽  
Excitatory Synapses ◽  
Detailed Characterization ◽  
High Affinity ◽  
Acid Sensing Ion Channels ◽  
Long Time ◽  
Pathological Pain

Acid-sensing ion channels (ASICs) are proton-gated Na+ channels. Being almost ubiquitously present in neurons of the vertebrate nervous system, their precise function remained obscure for a long time. Various animal toxins that bind to ASICs with high affinity and specificity have been tremendously helpful in uncovering the role of ASICs. We now know that they contribute to synaptic transmission at excitatory synapses as well as to sensing metabolic acidosis and nociception. Moreover, detailed characterization of mouse models uncovered an unanticipated role of ASICs in disorders of the nervous system like stroke, multiple sclerosis, and pathological pain. This review provides an overview on the expression, structure, and pharmacology of ASICs plus a summary of what is known and what is still unknown about their physiological functions and their roles in diseases.

Impulsivity and Drug Addiction: A Neurobiological Perspective

2012 ◽  
Author(s):  
Trevor Robbins
Keyword(s):  
Drug Addiction ◽  
Conceptual Analysis ◽  
Animal Studies ◽  
Reaction Time Task ◽  
Compulsive Behavior ◽  
Self Administration ◽  
Detailed Characterization ◽  
Cocaine Seeking ◽  
Serial Reaction

A conceptual analysis of the impulsivity construct in behavioral and neurobiological terms is followed by an analysis of its causal role in certain forms of drug addiction in both human and animal studies. The main focus of this chapter is on a rat model of impulsivity based on premature responding in the five-choice serial reaction time task and a more detailed characterization of this phenotype in neurobehavioral, neurochemical, and genetic terms. Evidence is surveyed that high impulsivity on this task is associated with the escalation subsequently of cocaine self-administration behavior and also with a tendency toward compulsive cocaine seeking. Novelty reactivity, by contrast, is associated with the enhanced acquisition of self-administration, but not with the escalation of intravenous self-administration of cocaine or the development of compulsive behavior associated with cocaine seeking. These results indicate that the vulnerability to stimulant addiction may depend on different factors, as expressed through distinct presumed endophenotypes. These observations help us further to dissociate various aspects of the impulsivity construct in neural as well as behavioral terms.

scholarly journals New Trimethoprim-Like Molecules: Bacteriological Evaluation and Insights into Their Action

Antibiotics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 709
Author(s):  
Marta Jorba ◽  
Marina Pedrola ◽  
Ouldouz Ghashghaei ◽  
Rocío Herráez ◽  
Lluis Campos-Vicens ◽  
...  
Keyword(s):  
Inhibitory Concentration ◽  
Efflux Pump ◽  
Synergistic Effects ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Detailed Characterization ◽  
Low Concentrations ◽  
Pump Activity ◽  
Bacteriological Evaluation ◽  
Kinetics Of

This work reports a detailed characterization of the antimicrobial profile of two trimethoprim-like molecules (compounds 1a and 1b) identified in previous studies. Both molecules displayed remarkable antimicrobial activity, particularly when combined with sulfamethoxazole. In disk diffusion assays on Petri dishes, compounds 1a and 1b showed synergistic effects with colistin. Specifically, in combinations with low concentrations of colistin, very large increases in the activities of compounds 1a and 1b were determined, as demonstrated by alterations in the kinetics of bacterial growth despite only slight changes in the fractional inhibitory concentration index. The effect of colistin may be to increase the rate of antibiotic entry while reducing efflux pump activity. Compounds 1a and 1b were susceptible to extrusion by efflux pumps, whereas the inhibitor phenylalanine arginyl β-naphthylamide (PAβN) exerted effects similar to those of colistin. The interactions between the target enzyme (dihydrofolate reductase), the coenzyme nicotinamide adenine dinucleotide phosphate (NADPH), and the studied molecules were explored using enzymology tools and computational chemistry. A model based on docking results is reported.

scholarly journals Microscopic Image Segmentation and Morphological Characterization of Novel Chitosan/Silica Nanoparticle/Nisin Films Using Antimicrobial Technique for Blueberry Preservation

Membranes ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 303
Author(s):  
Rokayya Sami ◽  
Schahrazad Soltane ◽  
Mahmoud Helal
Keyword(s):  
Ph Value ◽  
Silica Nanoparticle ◽  
Morphological Characterization ◽  
Aerobic Bacteria ◽  
Nano Materials ◽  
Elongation At Break ◽  
Stable Suspension ◽  
Average Size ◽  
Material Ductility

In the current work, the characterization of novel chitosan/silica nanoparticle/nisin films with the addition of nisin as an antimicrobial technique for blueberry preservation during storage is investigated. Chitosan/Silica Nanoparticle/N (CH-SN-N) films presented a stable suspension as the surface loads (45.9 mV) and the distribution was considered broad (0.62). The result shows that the pH value was increased gradually with the addition of nisin to 4.12, while the turbidity was the highest at 0.39. The content of the insoluble matter and contact angle were the highest for the Chitosan/Silica Nanoparticle (CH-SN) film at 5.68%. The use of nano-materials in chitosan films decreased the material ductility, reduced the tensile strength and elongation-at-break of the membrane. The coated blueberries with Chitosan/Silica Nanoparticle/N films reported the lowest microbial contamination counts at 2.82 log CFU/g followed by Chitosan/Silica Nanoparticle at 3.73 and 3.58 log CFU/g for the aerobic bacteria, molds, and yeasts population, respectively. It was observed that (CH) film extracted 94 regions with an average size of 449.10, at the same time (CH-SN) film extracted 169 regions with an average size of 130.53. The (CH-SN-N) film presented the best result at 5.19%. It could be observed that the size of the total region of the fruit for the (CH) case was the smallest (1663 pixels), which implied that the fruit lost moisture content. As a conclusion, (CH-SN-N) film is recommended for blueberry preservation to prolong the shelf-life during storage.

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