Characterization of Adhesion Interlayer Between Rubber and Brass by a Novel Method of Sample Preparation

2007 ◽  
Vol 80 (1) ◽  
pp. 61-82 ◽  
Author(s):  
Takeshi Hotaka ◽  
Yasuhiro Ishikawa ◽  
Kunio Mori
Keyword(s):  
Filter Paper ◽  
Copper Sulfide ◽  
Hot Water ◽  
Rubber Matrix ◽  
Detailed Characterization ◽  
Initial Stage ◽  
Brass Surface ◽  
Novel Method ◽  
Clean Interface

Abstract Instrumental characterization of an adhesion interface in a rubber-brass system often faces a difficulty in exposing a clean surface due to a stick of rubber residue on a brass surface. We have succeeded in isolating an interface from the rubber matrix by inserting a filter paper between rubber and brass during the vulcanization. Clean interface was obtained by removing the filter paper after the vulcanization, enabling a detailed characterization of the interface by XPS and SEM-EDX from a practical rubber formulation. Formulation of cobalt naphthenate did not contribute to a formation of adhesion interlayer in an initial stage of cure, but greatly affected the composition of copper sulfide during the vulcanization. It was found that a dosage of cobalt improved a growth of interface at aging. Copper sulfide particles were found to be spherical at the interface for unaged specimens. It was revealed that excess growth of copper sulfide was a main feature at a humidity aging, while the growth of zinc oxide was eminent under a hot water aging. Scheme of an aging reaction was considered to depend on an interaction between brass and external factors such as heat, water, and oxygen.

scholarly journals Using Pedotransfer Function (PTF) analysis in the assessment of the parameters of potential radionuclide transport through the vadose zone of PRAW “Novi Han” – an initial stage of a model case study

2019 ◽  
Vol 48 (2) ◽  
pp. 3-12
Author(s):  
Dimitar Antonov ◽  
Nikolay Stoyanov ◽  
Aleksey Benderev
Keyword(s):  
Vadose Zone ◽  
Hydraulic Parameters ◽  
Radionuclide Transport ◽  
Pedotransfer Function ◽  
Radionuclide Migration ◽  
Detailed Characterization ◽  
Model Case ◽  
Initial Stage

The Repository for Radioactive Waste in Novi Han, Lozen Mountain (Bulgaria), dates from the early 1960s. In the present study, the complex geoenvironmental setting of the repository site was analysed from the viewpoint of assessment of potential radionuclide migration from the repository to the geosphere. Thus, components of the mass transport field were elaborated as a part of a conceptual model. In connection with this, a detailed characterization of the subsurface, especially of the vadose zone around the repository, was performed. The fractions of sand, silt and clay based on the grain-size distribution curves of samples from the different hydrogeological units gathered on the site of RAW-Novi Han were implemented in the ROSETTA program, and the respective hydraulic parameters were determined. As a result, the entire vadose zone was hydraulically determined.

Characterization of the Initial Stage of Discharges between Micro-gap in Liquid using Optical Measurement

2010 ◽  
Vol 130 (4) ◽  
pp. 313-318
Author(s):  
Makoto Kanemaru ◽  
Shohei Sorimachi ◽  
Shinji Ibuka ◽  
Shozo Ishii
Keyword(s):  
Optical Measurement ◽  
Initial Stage

Characterization of dissolved organic matter (DOM) extracted from soils by hot water percolation (HWP)

2010 ◽  
Vol 59 (1) ◽  
pp. 99-108 ◽  
Author(s):  
M. Takács ◽  
Gy. Füleky
Keyword(s):  
Organic Matter ◽  
Humic Acid ◽  
Natural Organic Matter ◽  
Extraction Methods ◽  
Soil Samples ◽  
Hot Water ◽  
Soil Extracts ◽  
Water Percolation ◽  
Soil Humic Acid

The Hot Water Percolation (HWP) technique for preparing soil extracts has several advantages: it is easily carried out, fast, and several parameters can be measured from the same solution. The object of this study was to examine the possible use of HWP extracts for the characterization of soil organic matter. The HPLC-SEC chromatograms, UV-VIS and fluorescence properties of the HWP extracts were studied and the results were compared with those of the International Humic Substances Society (IHSS) Soil Humic Acid (HA), IHSS Soil Fulvic Acid (FA) and IHSS Suwannee Natural Organic Matter (NOM) standards as well as their HA counterparts isolated by traditional extraction methods from the original soil samples. The DOM of the HWP solution is probably a mixture of organic materials, which have some characteristics similar to the Soil FA fractions and NOM. The HWP extracted organic material can be studied and characterized using simple techniques, like UV-VIS and fluorescence spectroscopy.

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.

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