Study of Solvent Composition Effects on the Protonation Equilibria of Various Anilines by Multiple Linear Regression and Factor Analysis Applied to the Correlation Between Protonation Constants and Solvatochromic Parameters in Ethanol–Water Mixed Solvents

2004 ◽  
Vol 33 (5) ◽  
pp. 479-497 ◽  
Author(s):  
Yüksel Altun
Keyword(s):  
Factor Analysis ◽  
Linear Regression ◽  
Multiple Linear Regression ◽  
Mixed Solvents ◽  
Solvent Composition ◽  
Protonation Constants ◽  
Solvatochromic Parameters ◽  
Protonation Equilibria ◽  
Composition Effects

Interpretation of Hydroxylic Solvent Effects Based on Correlations with Solvent Parameters. Reaction of Et3N with EtI

1994 ◽  
Vol 59 (4) ◽  
pp. 898-904 ◽  
Author(s):  
António R. T. Calado ◽  
Lídia M. V. Pinheiro ◽  
Lídia M. P. C. Albuquerque ◽  
Raquel M. C. Goncalves ◽  
Martí Rosés ◽  
...  
Keyword(s):  
Energy Density ◽  
Linear Regression ◽  
Multiple Linear Regression ◽  
Solvent Effects ◽  
Rate Constants ◽  
Cohesive Energy ◽  
Regression Equations ◽  
Solvatochromic Parameters ◽  
Cohesive Energy Density ◽  
Solvent Parameters

Hydroxylic solvent effects on 20 rate constants, k, of the Menschutkin reaction of Et3N with EtI are unravelled and rationalized by means of multiple linear regression equations. To perform this analysis new k values in 2 mono- and 9 dialcohols are obtained. New values are also presented for the Kamlet and Taft solvatochromic parameters π*, α and β of 1-hexanol. The results show that the solvent dipolarity, polarizability and cohesive energy density are the main properties influencing the reactivity, for the set of studied solvents.

scholarly journals Resilience measures to dealing with the COVID-19 pandemic Evidence from Romanian micro and small enterprises

2020 ◽  
Vol 15 (s1) ◽  
pp. 439-457
Author(s):  
Carmen Păunescu ◽  
Enikő Mátyus
Keyword(s):  
Factor Analysis ◽  
Linear Regression ◽  
Multiple Linear Regression ◽  
Exploratory Factor Analysis ◽  
Strong Support ◽  
Small Enterprises ◽  
Business Operations ◽  
Operational Management ◽  
Micro And Small Enterprises

AbstractCOVID-19 has created an un-precedent crisis for SMEs and challenged each single enterprise to reconsider its business operations and to adapt to the new unexpected circumstances. The present paper aims to explore the resilience measures that the micro and small enterprises in Romania can consider to dealing with the disruptions caused by the pandemic. A questionnaire-based survey was used to collect data from a sample of micro and small enterprises operating in the central part of the country. An exploratory factor analysis was employed to identify underlying variables that explain the pattern of correlations between the resilience measures for enterprises, which help them cope with the pandemic effects. There are seventeen resilience measures to the pandemic included in the analysis and further tested in the paper. In addition, a multiple linear regression was conducted to determine which of the resilience measures has the most impact on the enterprises’ overcoming illness. The results show that in order for the micro and small enterprises to better cope with the disruption caused by the COVID-19 pandemic they should demonstrate, on the first place, openness to production innovation and adaptation and ensure a strong support for customers and communities. On the second place, efforts should be directed toward ensuring efficiency of their internal operational management and worker protection. While there exist external circumstances that lead enterprises to adopt several resilience measures to better respond to the pandemic, the motivations that are most relevant in this decision are generally internal in nature.

Evaluation of Community Perception towards Tourism Industry

2015 ◽  
Vol 4 (4) ◽  
pp. 31-53
Author(s):  
Yidnekachew Mare ◽  
Emmanuel Gebreyohannes ◽  
Yohannes Yebabe Tesfay
Keyword(s):  
Factor Analysis ◽  
Linear Regression ◽  
Multiple Linear Regression ◽  
Linear Regression Analysis ◽  
Multiple Linear Regression Analysis ◽  
Tourism Industry ◽  
Community Perception ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
Potential Factors

The purpose of this study was to identify and analyze the factors affecting the perception of Hawassa community towards the tourism industry using Factor Analysis, Multiple linear regression and Multivariate Analysis of Variance (MANOVA). Cross-sectional survey was conducted on a sample of 591 from a target population of 24021 of Hawassa City. The Factor analysis estimation result identified five potential factors that affect the community's perception towards the tourism industry. These potential factors are economic, socio-cultural, environmental, community service and community attitude factors, which explained 77.5 percent of the total variation of the community's perception towards the tourism industry. Multiple linear regression analysis indicated that length of residency, number of tourist contacts, number of recreational activities, job creation and tourism policy participation are found significant in explaining the variation in the underlined perceptions of the community towards tourism. Among the demographic characteristics, sub city, sex, educational level, working profession and monthly income of the respondents are found were statistically significant different for the mean scores of the perceptions towards tourism.

Determination of substituent effects by factor analysis and multiple linear regression for the carbon-13 nuclear magnetic resonance chemical shifts in 4-substituted phenols and 2-nitrophenols

1987 ◽  
Vol 65 (6) ◽  
pp. 1316-1321 ◽  
Author(s):  
Harold M. Hutton ◽  
Kenneth R. Kunz ◽  
John D. Bozek ◽  
Barry J. Blackburn
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Factor Analysis ◽  
Magnetic Resonance ◽  
Linear Regression ◽  
Multiple Linear Regression ◽  
Chemical Shifts ◽  
Substituent Effects ◽  
Correlation Coefficients ◽  
Substituted Phenols ◽  
Nuclear Magnetic

Carbon-13 nuclear magnetic resonance chemical shifts are reported for a series of 4-substituted phenols and 2-nitrophenols in dimethyl sulfoxide solution. For chemical shift correlations, it was found by factor analysis and iterative multiple linear regression that the para chemical shifts require two substituent factors whereas the ipso, ortho, and meta chemical shifts require three factors. Regression analyses were performed using the field and resonance parameters (σF, σR0) and the appropriate ipso, ortho, and meta parameters (I, O, M) determined by Reynolds. Good correlations were obtained except for the three meta carbon analyses, where the correlation coefficients range from 0.877 to 0.963.

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