Topological indices

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1 - تبیین مولفه های مؤثر بر دلبستگی به مکان از منظر گروه نوجوان در شهر تهران
زهرا خدائی مجتبی رفیعیان هاشم داداش پور علی اکبر تقوایی

این تحقیق به بررسی و سنجش مولفه های اثر گذار بر دلبستگی به مکان و تبیین معناداری یا عدم معناداری آنها در محله های منتخبی از شهر تهران می پردازد. روش این مطالعه از نوع توصیفی- تحلیلی بوده است و داده ها با توزیع 475پرسشنامه با نوجوانان در رده سنی (12- 16) ساله که به روش چکیده کامل

این تحقیق به بررسی و سنجش مولفه های اثر گذار بر دلبستگی به مکان و تبیین معناداری یا عدم معناداری آنها در محله های منتخبی از شهر تهران می پردازد. روش این مطالعه از نوع توصیفی- تحلیلی بوده است و داده ها با توزیع 475پرسشنامه با نوجوانان در رده سنی (12- 16) ساله که به روش طبقه ای سیستماتیک انتخاب شده اند، انجام شد. در این مقاله، شاخص دلبستگی به مکان به تفکیک در چهار محله مورد بررسی قرار گرفت. بدین منظور از آزمون پارامتریک F و نیز آزمون Tukey (تفاوت معناداری) استفاده شد تا بتوان محله های منتخب را خوشه بندی و به این سئوال پاسخ داد که کدام محله ها، شبیه به هم و کدام محله ها با هم متفاوت هستند. در انتها، محله ها از نظر شاخص دلبستگی به مکان مقایسه شده و مولفه های دلبستگی به محله با استفاده از ضریب لامبدا مورد تبیین قرار گرفتند. پرونده مقاله

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2 - Quantitative Structure-Property Relationship to Predict Quantum Properties of Monocarboxylic Acids By using Topological Indices
fatemeh shafiei

Abstract. Topological indices are the numerical value associated with chemical constitution purporting for correlation of chemical structure with various physical properties, chemical reactivity or biological activity. Graph theory is a delightful playground for the exp چکیده کامل

Abstract. Topological indices are the numerical value associated with chemical constitution purporting for correlation of chemical structure with various physical properties, chemical reactivity or biological activity. Graph theory is a delightful playground for the exploration of proof techniques in Discrete Mathematics and its results have applications in many areas of sciences. A graph is a topological concept rather than a geometrical concept of fixed geometry, and hence Euclidean metric lengths, angles and three-dimensional spatial configurations have no meaning. One of the useful indices for examination of structure- property relationship is Randic' index. In this study, the relationship between the Randic'(1X), Balaban (J) and Szeged (Sz) indices and Harary numbers (H) to the thermal energy (Eth), heat capacity (Cv) and entropy(S) of monocarboxylic acids (C2- C20) are established. The thermodynamic properties are taken from HF level using the ab initio 6-31 G basis sets from the program package Gussian 98. Then, some useful topological indices for examination of the structure- property relationship are presented. پرونده مقاله

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3 - Application of Graph Theory: Investigation of Relationship Between Boiling Temperatures of Olefins and Topological Indices
Esmat Mohammadinasab

Abstract: In this study an appropriate computational approach was presented for estimating the boiling temperatures of 41 different types of olefins and their derivatives. Based on the guidelines of this approach, several structural indices related to the organic compon چکیده کامل

Abstract: In this study an appropriate computational approach was presented for estimating the boiling temperatures of 41 different types of olefins and their derivatives. Based on the guidelines of this approach, several structural indices related to the organic components were applied using graph theory. Meanwhile, in addition to evaluating the relation between the boiling temperatures of olefins with the structural indices, the property estimation was done with the help of multiple non-linear regression model and other suitable coefficients. For specifying the best structural descriptors out of seven descriptors for determining the considered boiling temperatures, the most appropriate one was specified with the help of multiple non-linear regression model. It was determined that a combined model of Harary and Randic indices is appropriate for determining the boiling temperatures of olefins. The best model to predict Tboil of olefins was obtained as follows: Tboil/K= 0.112 H**2 + 2.148 exp (χ) + 290.606 پرونده مقاله

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4 - The Structural Relationship Between Topological Indices and Some Thermodynamic Properties
F. Shafiei M. Aghaie K. Zare H. Aghaie

The fact that the properties of a molecule are tightly connected to its structural characteristics is one of the fundamental concepts in chemistry. In this connection, graph theory has been successfully applied in developing some relationships between topological indice چکیده کامل

The fact that the properties of a molecule are tightly connected to its structural characteristics is one of the fundamental concepts in chemistry. In this connection, graph theory has been successfully applied in developing some relationships between topological indices and some thermodynamic properties. So , a novel method for computing the new descriptors to construct a quantitative relation between structure and properties is presented. At first, a brief review on the classical graph theories introduced and, then, the link with molecular similarity is drawn. In the applications section, molecular topological indices are calculated. Afterwards, the molecular descriptors, that include the necessary structural information for properly describtion of system are employed to derive a numerical correlation with thermodynamic properties. Finally, some useful topological indices for examination of the structure-property relationship are presented. In addition, the relationship between the Randic, Wiener, Hosoya , Balaban and Schultz indices and Harary numbers and Distance matrix to the enthalpies of formation, heat capacities, (Cp) , enthalpies of combustion, enthalpies of vaporization and normal boiling points for normal alcohols is established. پرونده مقاله

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5 - Application of Graph Theory to Some Thermodynamic Properties and Topological Indices
H. Aghaie M. Monajjemi F. Shafiei

The relationship between the Randic , Wiener, Hosoya , Balaban, Schultz indices, Harary numbers andDistance matrix to enthalpies of formation (Airf), heat capacity, (Cp) , enthalpies of combustion (AH °c ),enthalpy of vaporization (AH °vap) and normal boiling po چکیده کامل

The relationship between the Randic , Wiener, Hosoya , Balaban, Schultz indices, Harary numbers andDistance matrix to enthalpies of formation (Airf), heat capacity, (Cp) , enthalpies of combustion (AH °c ),enthalpy of vaporization (AH °vap) and normal boiling points (bpK)of C2 C10 normal alkanes isrepresented پرونده مقاله

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6 - Application of Graph Theory: Relationship of Topological Indices with the Partition Coefficient (logP) of the Monocarboxylic Acids
Fatemeh Shafiei

It is well known that the chemical behavior of a compound is dependent upon the structure of itsmolecules. Quantitative structure activity relationship (QSAR) studies and quantitative structure property relationship (QSPR) studies are active areas of chemical research چکیده کامل

It is well known that the chemical behavior of a compound is dependent upon the structure of itsmolecules. Quantitative structure activity relationship (QSAR) studies and quantitative structure property relationship (QSPR) studies are active areas of chemical research that focus on the nature ofthis dependency. Topological indices are the numerical value associated with chemical constitutionpurporting for correlation of chemical structure with various physical properties, chemical reactivityor biological activity. Graph theory is a delightful playground for the exploration of proof techniquesin Discrete Mathematics and its results have applications in many areas of sciences. One of the usefulindices for examination of structure- property relationship is Randic' index. In this study isrepresented the relationship between the Randic', Balaban and Szeged indices and Harary numbers tothe octanol-water partition coefficient (logP) of monocarboxylic acids (C2- C20) are established, andthen, some useful topological indices for examination of the structure- property relationship arepresented. پرونده مقاله

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7 - Application of topological and physicochemical descriptors: QSTR analysis of the toxicity of benzene derivatives
H. Hosseini F. Shafiei

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8 - Balaban Index of C4C8(S) Nanotubes
Abbas Heydari

where m is the number of edges, μ is the cyclomatic number of G, d(u) is thesum of distances between vertex u and all of the vertices of G, and the summationgoes over all edges from the edge set E(G). In this paper we obtain amethod for calculating the Balaban index چکیده کامل

where m is the number of edges, μ is the cyclomatic number of G, d(u) is thesum of distances between vertex u and all of the vertices of G, and the summationgoes over all edges from the edge set E(G). In this paper we obtain amethod for calculating the Balaban index of nanotubes which have square andoctagon structure and denoted by C4C8(S) nanotubes. پرونده مقاله

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9 - A new method for computation of Wiener index if C4C8(S) Nanotorus
Abbas Heydari

The Wiener index of a graph G is defined as W(G) = ... where V (G) is the setof all vertices of G and for i,j in V (G), d(i,j) is the minimum distance between i and j. Ashrafiand yousefi (see A. R. Ashrafi and S. Yousefi, Computing the Wiener Index of a TUC4C8(S)Nanotor چکیده کامل

The Wiener index of a graph G is defined as W(G) = ... where V (G) is the setof all vertices of G and for i,j in V (G), d(i,j) is the minimum distance between i and j. Ashrafiand yousefi (see A. R. Ashrafi and S. Yousefi, Computing the Wiener Index of a TUC4C8(S)Nanotorus, MATCH Commun. Math. Comput. Chem., 57(2)(2007), 403-410) computed theWiener index of TUC4C8(S) Nanotorus. In this paper we use a new method to compute theWiener index of these Nanotorus. پرونده مقاله

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