Structure–boiling point relationships of alkanes using the multifunctional autocorrelation method

2001 ◽  
Vol 7 (4) ◽  
pp. 65-69 ◽  
Author(s):  
Mohamed Nohair ◽  
Driss Zakarya ◽  
Hamid Nyassi
Author(s):  
Mohamed Nohair ◽  
Noura Mallouk ◽  
Marouane Benmarzouk ◽  
El Morrakchi Mohssine

A three-layer feed forward neural network trained with a Levenberg–Marquardt batch error back propagation algorithm has been used to model the strong relationships between the boiling point of aliphatic alcohols and intermolecular forces consisting both in Van Der Waals forces and polar interactions, respectively. For that purpose, we use the multifunctional autocorrelation method to provide an appropriate topological description. Two types of descriptors are generated: the first is commonly used in QSARs and QSPRs modelling, it gives a general description of the whole of the molecule; the second is attributed to the local description of the group hydroxyl. In this we have turned our interests to the explanatory capacities of our methodology to explore the relative contribution and/or the contribution profile of the input factors compared to the size of the molecule. The initial data set is divided into different subsets in increasing order of values of boiling point. Then, we explore the good descriptive ability of the molecular descriptors calculated solely from the modified autocorrelation method to carry out a variable analysis and give information about features of the compounds responsible for their boiling points. This is made possible by comparing the regression coefficients for the established linear model, and by using the Garson weight portioning method for the ANN analysis.


2012 ◽  
Vol 9 (2) ◽  
pp. 1
Author(s):  
Asra Hosseini

From earliest cities to the present, spatial division into residential zones and neighbourhoods is the universal feature of urban areas. This study explored issue of measuring neighbourhoods through spatial autocorrelation method based on Moran's I index in respect of achieving to best neighbourhoods' model for forming cities smarter. The research carried out by selection of 35 neighbourhoods only within central part of traditional city of Kerman in Iran. The results illustrate, 75% of neighbourhoods' area in the inner city of Kerman had clustered pattern, and it shows reduction in Moran's index is associated with disproportional distribution of density and increasing in Moran's I and Z-score have monotonic relation with more dense areas and clustered pattern. It may be more efficient for urban planner to focus on spatial autocorrelation to foster neighbourhood cohesion rather than emphasis on suburban area. It is recommended characteristics of historic neighbourhoods can be successfully linked to redevelopment plans toward making city smarter, and also people's quality of life can be related to the way that neighbourhoods' patterns are defined. 


2012 ◽  
Vol 9 (2) ◽  
pp. 1
Author(s):  
Asra Hosseini

From earliest cities to the present, spatial division into residential zones and neighbourhoods is the universal feature ofurban areas. This study explored issue ofmeasuring neighbourhoods through spatial autocorrelation method based on Moran's I index in respect of achieving to best neighbourhoods' model for forming cities smarter. The research carried out by selection of 35 neighbourhoods only within central part of traditional city of Kerman in Iran. The results illustrate, 75% ofneighbourhoods, area in the inner city of Kerman had clustered pattern, and it shows reduction in Moran's index is associated with disproportional distribution of density and increasing in Moran's I and Z-score have monotonic relation with more dense areas and clustered pattern. It may be more efficient for urban planner to focus on spatial autocorrelation to foster neighbourhood cohesion rather than emphasis on suburban area. It is recommended characteristics of historic neighbourhoods can be successfully linked to redevelopment plans toward making city smarter, and also people's quality of life can be related to the way that neighbourhoods' patterns are defined.


Author(s):  
M.A. Nisbet ◽  
S. Schmeller

AbstractBoth the vapour and particulate phases of tobacco smoke have been shown to retard benzoyI-peroxide-initiated polymerisation of vinyl acetate by interception of the radicals involved in the polymerisation process. The extent of inhibition of polymerisation by test compounds is estimated by measuring time taken for a mixture of monomer and benzoyl peroxide, immersed in a water-bath at 70°C, to reach a spontaneous boil and comparing it with the time required for a similar mixture with added retarder to reach boiling point. Units are expressed as minutes of inhibition per part per million of inhibitor × 10


Alloy Digest ◽  
1956 ◽  
Vol 5 (11) ◽  

Abstract HASTELLOY ALLOY-D is a cast alloy composed primarily of nickel and silicon, and is exceptionally resistant to sulfuric acid of all concentrations even up to the boiling point. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Ni-29. Producer or source: Haynes Stellite Company.


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