Rogers Harry-O'kuru

Dr. Rogers Harry-O'kuru


Research Focus & Metrics

Academic Career Length

18Years (2009-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 April 2010 in Applied Spectroscopy
Verified
Journal Article
Closed access
SGS. H. Gordon
S. H. Gordon
AMAbdellatif Mohamed
Abdellatif Mohamed
RHRogers Harry-O'kuru
Rogers Harry-O'kuru
SIS. H. Imam
S. H. Imam
Mid-infrared (mid-IR) analysis of solid biomaterials by the familiar KBr disc technique is all too often frustrated by water interference in the very important protein (amide) and carbohydrate (hydroxyl) regions of their spectra. A method was therefore devised that overcomes the difficulty and corrects IR spectra of solid biomaterials in KBr discs by mathematically eliminating the interference that arises from water molecules absorbed and bound in the KBr crystal lattice. The derivation of a linear system of chemometric equations that solves the water interference problem in a rigorous objective way is presented. Infrared spectra that result after correction by the method can be used reliably for quantitative analysis as well as structure identification. A major advantage is realized in quantitative analysis as the technique permits cryogenic pulverization of the biomaterial in KBr to prevent change in chemical structure and minimize the particle size to closely approach the solid solution condition required by the Beer–Lambert law. Extensive pulverization, which produces large water absorption bands that overlap and obscure the amide and hydroxyl regions of interest, is no longer problematic. The method is illustrated by removing strong water interference to extract the spectra of corn starch and gluten in pressed KBr discs. Results of the new method are compared with attenuated total reflection (ATR) spectra of gluten corrected using the conventional advanced ATR correction algorithm.

23 March 2011 in Journal of Agricultural and Food Chemistry
Verified
Journal Article
Closed access
RHRogers Harry-O'kuru
Rogers Harry-O'kuru
GBGirma Biresaw
Girma Biresaw
SCSteven C. Cermak
Steven C. Cermak
SGSherald H. Gordon
Sherald H. Gordon
KVKarl Vermillion
Karl Vermillion

20 July 2015 in Journal of Agricultural and Food Chemistry
Verified
Journal Article
Closed access
RHRogers Harry-O'kuru
Rogers Harry-O'kuru
BTBrent Tisserat
Brent Tisserat
SGSherald H. Gordon
Sherald H. Gordon
AGAlan Gravett
Alan Gravett

18 February 2011 in Journal of the American Oil Chemists' Society
Verified
Journal Article
Closed access
PDF file
RHRogers Harry-O'kuru
Rogers Harry-O'kuru
AMA. Mohamed
A. Mohamed
JXJ. Xu
J. Xu
BSB. K. Sharma
B. K. Sharma

1 February 2018 in Journal of Analytical Methods in Chemistry
Verified
Journal Article
Open access
PDF file
RHRogers Harry-O'kuru
Rogers Harry-O'kuru
GBGirma Biresaw
Girma Biresaw
SGSherald Gordon
Sherald Gordon
JXJingyuan Xu
Jingyuan Xu
Jojoba liquid wax is a mixture of esters of long-chain fatty acids and fatty alcohols mainly C38:2–C46:2. The oil exhibits excellent emolliency on the skin and, therefore, is a component in many personal care cosmetic formulations. The virgin oil is a component of the seed of the jojoba (Simmondsia chinensis) plant which occurs naturally in the Sonora Desert in the United States and northwestern Mexico as well as in the northeastern Sahara desert. The seed contains 50–60% oil by dry weight. The plant has been introduced into Australia, Argentina, and Israel for commercial production of the jojoba oil. As a natural lubricant, we are seeking to explore its potential as a renewable industrial lubricant additive. Thus, we have chemically modified the carbon-carbon double bonds in the oil structure in order to improve its already good resistance to air oxidation so as to enhance its utility as well as its shelf life in nonpersonal care applications. To achieve this goal, we have hydroxylated its –C=C– bonds. Acylation of the resulting hydroxyl moieties has generated short-chain vicinal acyl substituents on the oil which keep the wax liquid, improving its cold flow properties and also protecting it from auto-oxidation and rancidity.

24 April 2018 in Fibers
Verified
Journal Article
Open access
PDF file
BTBrent Tisserat
Brent Tisserat
FEFred Eller
Fred Eller
RHRogers Harry-O'kuru
Rogers Harry-O'kuru
Lignocellulosic composite (LC) panels were fabricated using an adhesive matrix prepared from three different agricultural by-products: dried distillers grains with solubles (DDGS), pennycress (Thlaspi arvense L.) press cake (PPC), or lesquerella [Lesquerella fendleri (A. Gary) S. Watson] press cake (LPC) reinforced with Paulownia elongata L. wood (PW) particles. The goal in this study was to assess the mechanical properties of composites utilizing these low-cost matrix materials, which were subjected to various oil extraction methods. Three types of oil extraction methods were utilized: ethanol, supercritical CO2, and hexane, in order to generate matrix materials. These matrix materials were mixed with equal proportions of PW and hot pressed to generate panels. Overall, hexane extraction was the best method to enhance the mechanical properties of the matrices used to fabricate lignocellulosic composites. LPC’s produced a matrix that gave the resulting composite superior flexural properties compared to composites generated from DDGS and PPC matrices. The mechanical properties of composites generated from soy products (soybean meal flour or soy protein isolate) were similar to those derived from DDGS, PPC, or LPC. The dimensional stability properties of LCs were improved when the hexane extraction method was employed, unlike with the other extraction methods that were used to generate matrices.