scholarly journals Application of the log k pair linearity rule and proportionality rule to the RPP mobile phase scales estimation on diol-silica column

2000 ◽  
Vol 65 (10) ◽  
pp. 733-742
Author(s):  
Tomislav Janjic ◽  
Gordana Vuckovic ◽  
Milenko Celap
Keyword(s):  
Linear Function ◽  
Linear Correlation ◽  
Mobile Phase ◽  
Correlation Coefficients ◽  
Practical Work ◽  
Silica Column ◽  
The Third ◽  
Proportionality Rule ◽  
Diol Silica ◽  
Better Than

By the application of the Log ? pair linearity rule and the Proportionality rule to the previously published log ? values for 27 compounds, obtained on diol-silica columns with acetonitrile, methanol and tetrahydrofuran as modifiers, the existence of common RPP scales was established. The obtained correlation coefficients of the linear function log k = f(RPP) were better than 0.9900 for 26 compounds in the first, 21 in the second and 20 in the third case. In addition, in the case of the two first modifiers a linear correlation between the obtained RPP values and mol % of modifier in the mobile phase was found. On the basis of this, the following simple linear function: log k= f(mol % of modifier) was proposed as a criterion for log k values judgment in practical work. A linear correlation was also established between intercept and slope of the function, in spite of the fact that the investigated compounds essentially differ in their descriptors.

Adsorption of Copper Ions from Aqueous Solutions by Chitin

2012 ◽  
Vol 550-553 ◽  
pp. 2424-2427
Author(s):  
Chung Hsin Wu ◽  
Chao Yin Kuo ◽  
Meng Jia Chen
Keyword(s):  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Linear Correlation ◽  
Langmuir Isotherm ◽  
Copper Ions ◽  
Correlation Coefficients ◽  
Freundlich Isotherm ◽  
Freundlich Isotherms ◽  
Langmuir And Freundlich Isotherms ◽  
Better Than

This study utilizes chitin to remove dissolved Cu(II) from aqueous solutions. The effects of the dissolved Cu(II) concentration, chitin dosage, and pH on adsorption of dissolved Cu(II) by chitin are determined. Adsorption capacity for 20 and 80 mg/L dissolved Cu(II) onto chitin (2 g/L) was 3.86 mg/g and 5.12 mg/g, respectively. The dissolved Cu(II) adsorption percentage increased from 39% to 70% when the chitin dosage was increased from 2 g/L to 4 g/L. The linear correlation coefficients of Langmuir and Freundlich isotherms were obtained. Analytical results demonstrate that the Freundlich isotherm fitted experimental results better than did the Langmuir isotherm. Enthalpy (ΔH0) and entropy (ΔS0) for dissolved Cu(II) adsorption were 8.46 kJ/mol and 123.1 J/mol.K, respectively.

scholarly journals Application of the log k pair linearity rule and proportionality rule to the RPP mobile phase scales estimation on cyano-silica column

2001 ◽  
Vol 66 (3) ◽  
pp. 173-178
Author(s):  
Tomislav Janjic ◽  
Gordana Vuckovic ◽  
Milenko Celap
Keyword(s):  
Linear Relationship ◽  
Satisfactory Agreement ◽  
Linear Dependence ◽  
Mobile Phase ◽  
Silica Column ◽  
Good Linear ◽  
Good Linear Relationship ◽  
Solvent Strength ◽  
Proportionality Rule

On the basis of literature-reported log k values, the Log k pair linearity rule and the Proportionality rule were found to be also valid in the case of cyano-silica sorbent, whenmethanol, acetonitrile or propane-2-olwere used as modifiers. The RPPscales, reflecting the solvent strength, are in good linear relationship with the experimentally determined log k values. Furthermore, in the case of methanol and acetonitrile, the linear dependence: log k = f(mol%of modifier) was also established. In the function obtained in a such way, the intercept and the slope exhibit an approximate linear dependence. Finally, in the case of methanol, the experimentally obtained log k values are in a satisfactory agreement with the values calculated by the above equation.

A Developmental Study of Intonation Recognition

1968 ◽  
Vol 11 (4) ◽  
pp. 825-832 ◽  
Author(s):  
Marilyn M. Corlew
Keyword(s):  
Significant Interaction ◽  
Multiple Choice ◽  
Semantic Content ◽  
First Grade ◽  
Choice Test ◽  
Developmental Study ◽  
Multiple Choice Test ◽  
The Third ◽  
Matching Test ◽  
Better Than

Two experiments investigated the information conveyed by intonation from speaker to listener. A multiple-choice test was devised to test the ability of 48 adults to recognize and label intonation when it was separated from all other meaning. Nine intonation contours whose labels were most agreed upon by adults were each matched with two English sentences (one with appropriate and one with inappropriate intonation and semantic content) to make a matching-test for children. The matching-test was tape-recorded and given to children in the first, third, and fifth grades (32 subjects in each grade). The first-grade children matched the intonations with significantly greater agreement than chance; but they agreed upon significantly fewer sentences than either the third or fifth graders. Some intonation contours were matched with significantly greater frequency than others. The performance of the girls was better than that of the boys on an impatient question and a simple command which indicates that there was a significant interaction between sex and intonation.

Using Connectionist Modules for Decision Support

1990 ◽  
Vol 29 (03) ◽  
pp. 167-181 ◽  
Author(s):  
G. Hripcsak
Keyword(s):  
Decision Support ◽  
Standard Deviation ◽  
Confidence Interval ◽  
Posterior Probability ◽  
Back Propagation ◽  
Connectionist Model ◽  
Test Set ◽  
The Third ◽  
Independent Test ◽  
Better Than

AbstractA connectionist model for decision support was constructed out of several back-propagation modules. Manifestations serve as input to the model; they may be real-valued, and the confidence in their measurement may be specified. The model produces as its output the posterior probability of disease. The model was trained on 1,000 cases taken from a simulated underlying population with three conditionally independent manifestations. The first manifestation had a linear relationship between value and posterior probability of disease, the second had a stepped relationship, and the third was normally distributed. An independent test set of 30,000 cases showed that the model was better able to estimate the posterior probability of disease (the standard deviation of residuals was 0.046, with a 95% confidence interval of 0.046-0.047) than a model constructed using logistic regression (with a standard deviation of residuals of 0.062, with a 95% confidence interval of 0.062-0.063). The model fitted the normal and stepped manifestations better than the linear one. It accommodated intermediate levels of confidence well.

Nucleophilicity and its parametrization

1989 ◽  
Vol 54 (1) ◽  
pp. 117-135
Author(s):  
Oldřich Pytela ◽  
Vítězslav Zima
Keyword(s):  
Regression Analysis ◽  
Linear Correlation ◽  
Correlation Equation ◽  
Chemical Processes ◽  
General Tendency ◽  
Orbital Interaction ◽  
Physico Chemical ◽  
Physical And Chemical ◽  
Two Parameter ◽  
Better Than

The method of conjugate deviations based on the regression analysis has been suggested for construction of a new nucleophilicity scale. This method has been applied to a set of 28 nucleophiles participating in 47 physical and chemical processes described in literature. The two-parameter nucleophilicity scale obtained represents-in the parameter denoted as ND-the general tendency to form a bond to an electrophile predominantly on the basis of the orbital interaction and-in the parameter denoted as PD-the ability to interact with a centre similar to the proton (basicity). The linear correlation equation involving the ND, PD parameters and the charge appears to be distinctly better than the most significant relations used. The correlation dependences have the physico-chemical meaning. From the position of individual nucleophiles in the space of the ND and PD parameters, some general conclusions have been derived about the factors governing the reactivity of nucleophiles.

scholarly journals Deep learning for intelligent diagnosis in thyroid scintigraphy

2021 ◽  
Vol 49 (1) ◽  
pp. 030006052098284
Author(s):  
Tingting Qiao ◽  
Simin Liu ◽  
Zhijun Cui ◽  
Xiaqing Yu ◽  
Haidong Cai ◽  
...  
Keyword(s):  
Deep Learning ◽  
Disease Diagnosis ◽  
Kappa Coefficient ◽  
Diagnostic Assessment ◽  
First Year ◽  
Thyroid Scintigraphy ◽  
Diagnostic Ability ◽  
The Third ◽  
Classification Time ◽  
Better Than

Objective To construct deep learning (DL) models to improve the accuracy and efficiency of thyroid disease diagnosis by thyroid scintigraphy. Methods We constructed DL models with AlexNet, VGGNet, and ResNet. The models were trained separately with transfer learning. We measured each model’s performance with six indicators: recall, precision, negative predictive value (NPV), specificity, accuracy, and F1-score. We also compared the diagnostic performances of first- and third-year nuclear medicine (NM) residents with assistance from the best-performing DL-based model. The Kappa coefficient and average classification time of each model were compared with those of two NM residents. Results The recall, precision, NPV, specificity, accuracy, and F1-score of the three models ranged from 73.33% to 97.00%. The Kappa coefficient of all three models was >0.710. All models performed better than the first-year NM resident but not as well as the third-year NM resident in terms of diagnostic ability. However, the ResNet model provided “diagnostic assistance” to the NM residents. The models provided results at speeds 400 to 600 times faster than the NM residents. Conclusion DL-based models perform well in diagnostic assessment by thyroid scintigraphy. These models may serve as tools for NM residents in the diagnosis of Graves’ disease and subacute thyroiditis.

scholarly journals A Preliminary Study on Dependence of Mercury Distribution on the Degree of Coalification in Ningwu Coalfield, Shanxi, China

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3119
Author(s):  
Yinjiao Su ◽  
Xuan Liu ◽  
Yang Teng ◽  
Kai Zhang
Keyword(s):  
Linear Correlation ◽  
Bituminous Coal ◽  
Rank Correlation ◽  
Correlation Coefficients ◽  
Chemical Extraction ◽  
Mercury Distribution ◽  
Sequential Chemical Extraction ◽  
Average Proportion ◽  
Total Proportion ◽  
The Relationship

Mercury (Hg) is a toxic trace element emitted from coal conversion and utilization. Samples with different coal ranks and gangue from Ningwu Coalfield are selected and investigated in this study. For understanding dependence of mercury distribution characteristics on coalification degree, Pearson regression analysis coupled with Spearman rank correlation is employed to explore the relationship between mercury and sulfur, mercury and ash in coal, and sequential chemical extraction method is adopted to recognize the Hg speciation in the samples of coal and gangue. The measured results show that Hg is positively related to total sulfur content in coal and the affinity of Hg to different sulfur forms varies with the coalification degree. Organic sulfur has the biggest impact on Hg in peat, which becomes weak with increasing the coalification degree from lignite to bituminous coal. Sulfate sulfur is only related to Hg in peat or lignite as little content in coal. However, the Pearson linear correlation coefficients of Hg and pyritic sulfur are relatively high with 0.479 for lignite, 0.709 for sub-bituminous coal and 0.887 for bituminous coal. Hg is also related to ash content in coal, whose Pearson linear correlation coefficients are 0.504, 0.774 and 0.827 respectively, in lignite, sub-bituminous coal and bituminous coal. Furthermore, Hg distribution is directly depended on own speciation in coal. The total proportion of F2 + F3 + F4 is increased from 41.5% in peat to 87.4% in bituminous coal, but the average proportion of F5 is decreased from 56.8% in peat to 12.4% in bituminous coal. The above findings imply that both Hg and sulfur enrich in coal largely due to the migration from organic state to inorganic state with the increase of coalification degree in Ningwu Coalfield.

Propertiana

1949 ◽  
Vol 43 (1-2) ◽  
pp. 22-29
Author(s):  
D. R. Shackleton Bailey
Keyword(s):  
Early Paper ◽  
The Moon ◽  
The Third ◽  
Better Than

Housman put the case against fallacia with characteristic trenchancy in an early paper (Journ. Phil, xvi, p. 25). ‘I conceive’, he wrote, ‘that so far as Latinity is concerned the words deductae fallacia lunae may bear any one of three meanings. First they may mean “false pretence of bringing down the moon”: a sense peremptorily forbidden by the context. Mr. Lucian Mueller points out that Propertius cannot look for help to those whom he holds and asserts to be impostors, and that argument is clinched by the tune ego crediderim of 23: Propertius now doubts whether the power of magic be real or no, but turn Cynthia's heart and he will believe. Secondly deductae fallacia lunae may legitimately mean “deceiving men by bringing down the moon” on the analogy of Ov. Met. 13. 164deceperat omnes, in quibus Aiacem, sumptae fallacia uestis. But plainly this sense is no better than nonsense: if magicians bring down the moon as men believe them to do, then men are not deceived. Equally absurd is the third possible sense of the words, deceiving the moon and bringing her down. I know that Pan deus Arcadiae captain te, Luna, fefellitin nemora alta means, but in what sense do magicians faltere lunam? What conceivable deceit do they employ? Manufacture a cerea effigies of Endymion I suppose and lay it on the mountain tops.’

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