Results 231 to 240 of about 5,663,589 (279)

Extremal values of vertex-degree-based topological indices of chemical trees

Applied Mathematics and Computation, 2020
One important topic in chemical graph theory is the extremal value problem of vertex-degree-based topological indices over chemical trees. It is our main goal in this paper to unify many of these results in one general theorem which captures the common ...
Roberto Cruz, Juan Monsalve, J. Rada
semanticscholar   +1 more source

A note on chemical trees with minimum Wiener polarity index

Applied Mathematics and Computation, 2018
The Wiener polarity index (usually denoted by Wp) of a graph G is defined as the number of unordered pairs of the vertices of G which are at distance 3. Denote by CTn the family of all n-vertex chemical trees. In a recent paper, Ashrafi and Ghalavand [1]
Akbar Ali, Z. Du, Muhammad Amjad Ali
semanticscholar   +1 more source

Chemical Trees with Maximal VDB Topological Indices

match Communications in Mathematical and in Computer Chemistry, 2023
Summary: A general vertex-degree-based (VDB) topological index of a graph \(G\) is defined as \[ \mathcal{T}_f=\mathcal{T}_f(G)=\sum_{uv\in E(G)}f(d_G(u),d_G(v)), \] where \(f(x,y)>0\) is a symmetric real function with \(x\ge 1\) and \(y\ge 1\).
openaire   +2 more sources

Counting Chemical Structures Resembling Trees

2018 International Conference on Advances in Computing, Communications and Informatics (ICACCI), 2018
Trees have been used for counting chemical structures of non-isomorphic forms. Graph enumeration can be either isomorphic or non-isomorphic. Isomorphic tree enumeration arises in the context of listing all isomorphic subtrees of a given graph whereas non-isomorphic enumeration lists all unique trees that satisfy given constraints. We study the chemical
Athira Selvam, Sravya K V S P Sai, Bhadrachalam Chitturi   +2 more
openaire   +1 more source

Fault tree synthesis for chemical processes

AIChE Journal, 1974
AbstractThis paper outlines the concepts for a systematic approach to the safety analysis of chemical processing systems. A procedure for automatically generating fault trees is presented. The fault trees describe nearly all the failure modes for the system under analysis.
Gary J. Powers, Frederick C. Tompkins
openaire   +1 more source

Complete Characterization of Chemical Trees with Maximal Augmented Zagreb Index

Journal of Applied Mathematics and Computation, 2023
Y. Shao, Wei Gao
semanticscholar   +1 more source

Mining environmental chemicals with boosted trees

Proceedings of the 35th Annual ACM Symposium on Applied Computing, 2020
In response to scientific reports and legislative actions, the United States Environmental Protection Agency (EPA) launched an Endocrine Disruptor Screening Program (EDSP). The overarching aim of this program is to develop novel analytical and computational tools and methods for the detection of environmental chemicals causing aberrations in estrogen ...
openaire   +1 more source

TECHNIQUES FOR INJECTING CHEMICALS INTO TREES

Arboricultural Journal, 1985
Summary Many existing techniques for applying solutions to woody plants are inexact, or require expensive apparatus and specialised training to use. Simple, cheap, and accurate methods are described for injecting volumes from 1 μ1 to 100 ml into main stems or branches of 5 mm diameter upwards.
J McP Dick, K A Longman
openaire   +1 more source

Decision tree for chemical detection applications

Analytical Chemistry, 1985
Analyse discriminante et par regression de l'augmentation de la fluorescence du (diphenylacetyl-2) indanedione-1,3 ((p-dimethylamino) benzaldazine)-1, reactif analytique possible pour pesticide, aminoacide, composes ...
William P. Ashman, James H. Lewis, Edward J. Poziomek   +2 more
openaire   +1 more source

Induced chemical defences in Colophospermum mopane trees

African Journal of Range & Forage Science, 2007
A field experiment was conducted in which Mopane (Colophospermum mopane) trees were subjected to three different canopy treatments:felling of trees at a mean height of 0.7m above ground level, felling at a height of 2m, or pruning of selected branches.
Wessels, D.C.J., van der Waal, C., de Boer, W.F.   +2 more
openaire   +2 more sources