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    <journal-meta>
      <journal-id journal-id-type="nlm-ta">REA Press</journal-id>
      <journal-id journal-id-type="publisher-id">Null</journal-id>
      <journal-title>REA Press</journal-title><issn pub-type="ppub">3042-3104</issn><issn pub-type="epub">3042-3104</issn><publisher>
      	<publisher-name>REA Press</publisher-name>
      </publisher>
    </journal-meta>
    <article-meta>
      <article-id pub-id-type="doi">https://doi.org/10.48314/apem.v3i1.57</article-id>
      <article-categories>
        <subj-group subj-group-type="heading">
          <subject>Research Article</subject>
        </subj-group>
        <subj-group><subject>Bio-based grease, Extreme pressure additives, Boundary lubrication, Specific wear rate, Rice husk pyrolysis oil, Agricultural waste valorization, Sustainable lubricants</subject></subj-group>
      </article-categories>
      <title-group>
        <article-title>Load-Dependent Tribological Performance of a Rice Husk–Derived Lithium Grease Without Conventional Extreme Pressure Additives</article-title><subtitle>Load-Dependent Tribological Performance of a Rice Husk–Derived Lithium Grease Without Conventional Extreme Pressure Additives</subtitle></title-group>
      <contrib-group><contrib contrib-type="author">
	<name name-style="western">
	<surname>Uchenna </surname>
		<given-names>Okaforobah</given-names>
	</name>
	<aff>Department of Mechanical Engineering, Nnamdi Azikiwe University, Awka, Nigeria.</aff>
	</contrib></contrib-group>		
      <pub-date pub-type="ppub">
        <month>01</month>
        <year>2026</year>
      </pub-date>
      <pub-date pub-type="epub">
        <day>07</day>
        <month>01</month>
        <year>2026</year>
      </pub-date>
      <volume>3</volume>
      <issue>1</issue>
      <permissions>
        <copyright-statement>© 2026 REA Press</copyright-statement>
        <copyright-year>2026</copyright-year>
        <license license-type="open-access" xlink:href="http://creativecommons.org/licenses/by/2.5/"><p>This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.</p></license>
      </permissions>
      <related-article related-article-type="companion" vol="2" page="e235" id="RA1" ext-link-type="pmc">
			<article-title>Load-Dependent Tribological Performance of a Rice Husk–Derived Lithium Grease Without Conventional Extreme Pressure Additives</article-title>
      </related-article>
	  <abstract abstract-type="toc">
		<p>
			This study evaluates the load-dependent tribological performance of a lithium grease formulated from rice husk–derived materials, comprising rice husk pyrolysis oil (60 wt%), lithium stearate thickener (35 wt%), and rice husk ash additive (5 wt%). Gravimetric wear tests were conducted at 1490 rpm under applied loads of 800 g, 900 g, and 1000 g, and the results were benchmarked against two commercial lithium-based greases. At 800 g, all greases exhibited comparable specific wear rates on the order of 10⁻⁶ – 10⁻⁷ g·N⁻¹·s⁻¹. However, at 1000 g, both commercial greases failed prematurely, entering a severe wear regime with specific wear rates of approximately 3.4–3.6 × 10⁻⁴ g·N⁻¹·s⁻¹. In contrast, the rice husk–derived grease completed the full 300 s test duration with a significantly lower wear rate of 1.70 × 10⁻⁶ g·N⁻¹·s⁻¹, corresponding to about a 99.5% reduction relative to the commercial formulations. This superior load-bearing performance is attributed to synergistic effects between polar oxygenated compounds in the bio-oil, the mechanically stable lithium stearate network, and load redistribution by finely dispersed rice husk ash particles. Notably, this performance was achieved without the use of conventional sulfur- or phosphorus-based extreme-pressure additives, demonstrating the potential of agro-residue-derived greases as a sustainable and high-performance alternative for lubrication applications.
		</p>
		</abstract>
    </article-meta>
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