scholarly journals Oxidation potentials of phenols and anilines: correlation analysis of electrochemical and theoretical values

2017 ◽  
Vol 19 (3) ◽  
pp. 339-349 ◽  
Author(s):  
Ania S. Pavitt ◽  
Eric J. Bylaska ◽  
Paul G. Tratnyek
Keyword(s):  
Correlation Analysis ◽  
Kinetic Data ◽  
Manganese Oxides ◽  
Substituted Phenols ◽  
Oxidation Potentials

New experimental and theoretical oxidation potentials for substituted phenols and anilines give improved correlations to kinetic data with manganese oxides.

Calculation of the relative acidities and oxidation potentials of para-substituted phenols. A model for α-tocopherol in solution

2007 ◽  
Vol 5 (11) ◽  
pp. 1739-1743 ◽  
Author(s):  
Nakul K. Singh ◽  
Majeed S. Shaik ◽  
Patrick J. O'Malley ◽  
Paul L. A. Popelier
Keyword(s):  
Substituted Phenols ◽  
Oxidation Potentials

scholarly journals Coexistence of Substituted Phenols Reduces the Fouling Ability of Phenol in Non-aqueous Solvents

2021 ◽  
Author(s):  
László Kiss
Keyword(s):  
Phenol Concentration ◽  
Aqueous Systems ◽  
Substituted Phenols ◽  
Oxidation Potentials

The electrooxidation of phenol showed different rate of deactivation by varying the concentration of substituted phenols (4-chlorophenol, 4-methoxyphenol, 4-tert-butylphenol). This was due to the more favourable solubility properties of the product copolymers compared with poly(phenyleneoxide) the product which forms when only unsubstituted phenol is present. The nature of substituent, switching potential and oxidation potentials of the studied phenols were significant in prevention of electrode fouling. The best reproducibility could be achived upon addition of 4-chlorophenol. This offered a possibility for estimation of phenol concentration in non-aqueous systems.

scholarly journals Correlation of the rates of solvolysis of α-bromoisobutyrophenone using both simple and extended forms of the Grunwald-Winstein equation and the application of correlation analysis to related studies

2018 ◽  
Vol 9 (1) ◽  
pp. 1-6
Author(s):  
Dennis Neil Kevill ◽  
Chang-Bae Kim ◽  
Malcolm John D’Souza
Keyword(s):  
Regression Analysis ◽  
Correlation Analysis ◽  
Multiple Regression Analysis ◽  
Linear Combination ◽  
Multiple Regression ◽  
Perchloric Acid ◽  
Kinetic Data ◽  
Aqueous Ethanol ◽  
Specific Rate ◽  
Silver Perchlorate

A Grunwald-Winstein treatment of the specific rates of solvolysis of α-bromoisobutyro phenone in 100% methanol and in several aqueous ethanol, methanol, acetone, 2,2,2-trifluoroethanol (TFE), and 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) mixtures gives a good logarithmic correlation against a linear combination of NT (solvent nucleophilicity) and YBr (solvent ionizing power) values. The l and m sensitivity values are compared to those previously reported for α-bromoacetophenone and to those obtained from parallel treatments of literature specific rate values for the solvolyses of several tertiary mesylates containing a C(=O)R group attached at the α-carbon. Kinetic data obtained earlier by Pasto and Sevenair for the solvolyses of the same substrate in 75% aqueous ethanol (by weight) in the presence of silver perchlorate and perchloric acid are analysed using multiple regression analysis.

scholarly journals 3-Pyridinols and 5-pyrimidinols: Tailor-made for use in synergistic radical-trapping co-antioxidant systems

2013 ◽  
Vol 9 ◽  
pp. 2781-2792 ◽  
Author(s):  
Luca Valgimigli ◽  
Daniele Bartolomei ◽  
Riccardo Amorati ◽  
Evan Haidasz ◽  
Jason J Hanthorn ◽  
...  
Keyword(s):  
Phenolic Compounds ◽  
Aromatic Ring ◽  
Kinetic Data ◽  
Peroxyl Radicals ◽  
Antioxidant Systems ◽  
Phenolic Antioxidants ◽  
Substituted Phenols ◽  
Radical Trapping ◽  
Insight Into

The incorporation of nitrogen atoms into the aromatic ring of phenolic compounds has enabled the development of some of the most potent radical-trapping antioxidants ever reported. These compounds, 3-pyridinols and 5-pyrimidinols, have stronger O–H bonds than equivalently substituted phenols, but possess similar reactivities toward autoxidation chain-carrying peroxyl radicals. These attributes suggest that 3-pyridinols and 5-pyrimidinols will be particularly effectiveco-antioxidants when used in combination with more common, but less reactive, phenolic antioxidants such as 2,6-di-tert-butyl-4-methylphenol (BHT), which we demonstrate herein. The antioxidants function in a synergistic manner to inhibit autoxidation; taking advantage of the higher reactivity of the 3-pyridinols/5-pyrimidinols to trap peroxyl radicals and using the less reactive phenols to regenerate them from their corresponding aryloxyl radicals. The present investigations were carried out in chlorobenzene and acetonitrile in order to provide some insight into the medium dependence of the synergism and the results, considered with some from our earlier work, prompt a revision of the H-bonding basicity value of acetonitrile to β2 H of 0.39. Overall, the thermodynamic and kinetic data presented here enable the design of co-antioxidant systems comprising lower loadings of the more expensive 3-pyridinol/5-pyrimidinol antioxidants and higher loadings of the less expensive phenolic antioxidants, but which are equally efficacious as the 3-pyridinol/5-pyrimidinol antioxidants alone at higher loadings.

Microdensitometer—computer correlation analysis of ultrastructural periodicity

1978 ◽  
Vol 36 (2) ◽  
pp. 32-33
Author(s):  
D.R. Ensor ◽  
C.G. Jensen ◽  
J.A. Fillery ◽  
R.J.K. Baker
Keyword(s):  
Correlation Analysis ◽  
Background Noise ◽  
Computer Control ◽  
Optical Diffraction ◽  
Screw Thread ◽  
Straight Line ◽  
Computer Storage ◽  
Correlation Process ◽  
Electron Microscope Image ◽  
Fixed Beam

Because periodicity is a major indicator of structural organisation numerous methods have been devised to demonstrate periodicity masked by background “noise” in the electron microscope image (e.g. photographic image reinforcement, Markham et al, 1964; optical diffraction techniques, Horne, 1977; McIntosh,1974). Computer correlation analysis of a densitometer tracing provides another means of minimising "noise". The correlation process uncovers periodic information by cancelling random elements. The technique is easily executed, the results are readily interpreted and the computer removes tedium, lends accuracy and assists in impartiality.A scanning densitometer was adapted to allow computer control of the scan and to give direct computer storage of the data. A photographic transparency of the image to be scanned is mounted on a stage coupled directly to an accurate screw thread driven by a stepping motor. The stage is moved so that the fixed beam of the densitometer (which is directed normal to the transparency) traces a straight line along the structure of interest in the image.

The German Strengths and Difficulties Questionnaire (SDQ)

2010 ◽  
Vol 26 (4) ◽  
pp. 256-262 ◽  
Author(s):  
Ulrike Petermann ◽  
Franz Petermann ◽  
Ina Schreyer
Keyword(s):  
Correlation Analysis ◽  
Teacher Ratings ◽  
Screening Instrument ◽  
Preschool Age ◽  
Strengths And Difficulties Questionnaire ◽  
Preschool Age Children ◽  
Discriminant Analyses ◽  
Strengths And Difficulties ◽  
Behavioral Attributes ◽  
And Behavior

The Strengths and Difficulties Questionnaire (SDQ) is a screening instrument that addresses positive and negative behavioral attributes of children and adolescents. Although this questionnaire has been used in Germany to gather information from parents and teachers of preschoolers, few studies exist that verify the validity of the German SDQ for this age. In the present study, teacher ratings were collected for 282 children aged 36 to 60 months (boys = 156; girls = 126). Likewise, teacher ratings were collected with another German checklist for behavior problems and behavior disorders at preschool age (Verhaltensbeurteilungsbogen für Vorschulkinder, VBV 3–6). Moreover, children’s developmental status was assessed. Evaluation included correlation analysis as well as canonical correlation analysis to assess the multivariate relationship between the set of SDQ variables and the set of VBV variables. Discriminant analyses were used to clarify which SDQ variables are useful to differentiate between children with or without developmental delay in a multivariate model. The results of correlation and discriminant analyses underline the validity of the SDQ for preschoolers. According to these results, the German teacher SDQ is recommended as a convenient and valid screening instrument to assess positive and negative behavior of preschool age children.

Kinetics of Various 99mTc-Sn-Pyrophosphate Compounds in the Rat

1977 ◽  
Vol 16 (03) ◽  
pp. 100-103 ◽  
Author(s):  
C. Schümichen ◽  
J. Waiden ◽  
G. Hoffmann
Keyword(s):  
Glomerular Filtration ◽  
Renal Clearance ◽  
Plasma Protein ◽  
Kinetic Data ◽  
Adult Rats ◽  
Compound A ◽  
Extravascular Space ◽  
Tubular Cells ◽  
Glomerular Filtrate ◽  
Kinetics Of

SummaryThe kinetic data of two different 99mTc-Sn-pyrophosphate compounds (compound A and B) were evaluated in non-adult rats. Only compound A concentrated in bone. Both compounds dispersed rapidly in the intravascular as well as the extravascular space. The plasma protein bond of both compounds increased with time after injection and impaired both the renal clearance of both compounds and the bone clearance of compound A. The renal clearance of both compounds was somewhat above that of 5 1Cr-EDTA. It is concluded that compound A and B is mainly excreted by glomerular filtration. About one fourth of the glomerular filtrate of compound B is reabsorbed and accumulated by the tubular cells.

Analysis of Maximum Expiratory Flow Volume Curves Using Canonical Correlation Analysis

1985 ◽  
Vol 24 (02) ◽  
pp. 91-100 ◽  
Author(s):  
W. van Pelt ◽  
Ph. H. Quanjer ◽  
M. E. Wise ◽  
E. van der Burg ◽  
R. van der Lende
Keyword(s):  
Correlation Analysis ◽  
Canonical Correlation Analysis ◽  
Canonical Correlation ◽  
Flow Volume ◽  
Non Linear ◽  
Maximum Expiratory Flow ◽  
Expiratory Flow ◽  
Relationship Of ◽  
The Relationship ◽  
Age And Sex

SummaryAs part of a population study on chronic lung disease in the Netherlands, an investigation is made of the relationship of both age and sex with indices describing the maximum expiratory flow-volume (MEFV) curve. To determine the relationship, non-linear canonical correlation was used as realized in the computer program CANALS, a combination of ordinary canonical correlation analysis (CCA) and non-linear transformations of the variables. This method enhances the generality of the relationship to be found and has the advantage of showing the relative importance of categories or ranges within a variable with respect to that relationship. The above is exemplified by describing the relationship of age and sex with variables concerning respiratory symptoms and smoking habits. The analysis of age and sex with MEFV curve indices shows that non-linear canonical correlation analysis is an efficient tool in analysing size and shape of the MEFV curve and can be used to derive parameters concerning the whole curve.

Factor V from Human Plasma

1961 ◽  
Vol 05 (01) ◽  
pp. 001-020
Author(s):  
Douglas M. Surgenor ◽  
Nancy A. Wilson ◽  
Anne S. Henry
Keyword(s):  
Human Serum ◽  
Human Plasma ◽  
Kinetic Data ◽  
Human Factor ◽  
Kinetic Studies ◽  
Partial Purification ◽  
Factor V ◽  
Two Stage ◽  
Plasma Factor ◽  
Tissue Thromboplastin

SummaryA method is described for the partial purification of a human plasma factor which accelerates the conversion of prothrombin to thrombin in the presence of tissue thromboplastin. This factor may be dried from the frozen state, and may be kept in stable dry form for long periods of time. The quantitative assay of this activity is done in a classical two-stage prothrombin system using tissue thromboplastin and calcium. From its properties, it is concluded that this activity corresponds to factor V, labile factor and plasma Ac-globulin.Chemical and kinetic studies reveal that human factor V is active in plasma and is destroyed by thrombin. Human serum has little or no factor V activity.These results thus fail to support the postulated activation of factor V during clotting. All of the kinetic data are consistent with an enzymatic role for factor V in the formation of tissue prothrombin activator (thromboplastin).

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