<?xml version="1.0" encoding="UTF-8"?>
<article article-type="Research Article">
  <front>
    <journal-meta>
      <journal-id journal-id-type="publisher">journal-of-information-and-optimization-sciences</journal-id>
      <journal-title-group>
        <journal-title>Journal of Information and Optimization Sciences</journal-title>
      </journal-title-group>
      <issn publication-format="electronic">2169-0103</issn>
      <issn publication-format="print">0252-2667</issn>
      <publisher>
        <publisher-name>Taru Publications</publisher-name>
      </publisher>
    </journal-meta>
    <article-meta>
      <article-id pub-id-type="doi">10.47974/JIOS-1123</article-id>
      <title-group>
        <article-title>Calculation of Gourava topological indices in HAC5C6C7[p, q] nanotubes</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <name>
            <surname>Tousi</surname>
            <given-names>Jaber Ramezani</given-names>
          </name>
          <aff>Department of Applied Mathematics, Faculty of Mathematics, Statistics and Computer Science, Semnan University, Semnan, 35131-19111, Iran</aff>
        </contrib>
        <contrib contrib-type="author" corresp="yes">
          <name>
            <surname>Ghods</surname>
            <given-names>Masoud</given-names>
          </name>
          <aff>Department of Applied Mathematics, Faculty of Mathematics, Statistics and Computer Science, Semnan University, Semnan, 35131-19111, Iran</aff>
        </contrib>
      </contrib-group>
      <volume>44</volume>
      <issue>5</issue>
      <fpage>823</fpage>
      <lpage>834</lpage>
      <pub-date date-type="pub">
        <day>10</day>
        <month>10</month>
        <year>2023</year>
      </pub-date>
      <abstract>
        <p>One of the best and most widely used carbon structures is carbon nanotubes. The most important features of carbon nanotubes are high durability, flexibility and good conductivity. In this article, the graph of HAC5C6C7[p, q] carbon nanotube structure is investigated using a section of its surface. By presenting a method for obtaining the degree of vertices in the relevant area, the topological indices of Gourava and Hyper Gourava are calculated, and the relevant theorems are expressed. The Gourava indices and Hyper Gourava indices are then calculated for the line graph and subdivision graph of HAC5C6C7[p, q]  Also, to compare the obtained values, the diagrams of Gourava and Hyper Gourava indices are drawn.</p>
      </abstract>
      <kwd-group>
        <kwd>Gourava indices</kwd>
        <kwd>HAC5C6C7[p</kwd>
        <kwd>q] nanotube</kwd>
        <kwd>Line graph</kwd>
        <kwd>Subdivision graph</kwd>
      </kwd-group>
      <custom-meta-group>
        <custom-meta>
          <meta-name>access</meta-name>
          <meta-value>open</meta-value>
        </custom-meta>
        <custom-meta>
          <meta-name>retracted</meta-name>
          <meta-value>no</meta-value>
        </custom-meta>
      </custom-meta-group>
    </article-meta>
  </front>
</article>
