Agumba, J. O., Namusonge, L., Ogendo, J., Hassan, M. A., Pembere, A., & Takavarasha, M. (2026). KESOZI Digital Twin: Physics-informed neural network for independent estimation and prediction of childhood diarrheal disease burden in Kenya, Somaliland, and Zimbabwe [Preprint]. https://doi.org/10.64898/2026.06.03.26354823
Agumba, J. O., Barasa, G. O., Takembo, C. N., Amuyunzu, P. M., & Owino, J. (2026).
Silver nanoparticle kinetics: plasmonic and quantum confinement modeling. Applied Physics A, 132(2). https://doi.org/10.1007/s00339-026-09291-x
John Onyango Agumba, Godfrey Okumu Barasa, Clovis Ntahkie Takembo et al.
Kinetic Modeling and Optical Property Evolution of Silver Nanoparticles from Water Hyacinth: A Simulation Approach Using Mie-Drude and Quantum Confinement Theories, 20 November 2025, PREPRINT (Version 1) available at Research Square. https://doi.org/10.21203/rs.3.rs-8157645/v1
Agumba, J. O., & Barasa, G. O. Computational Modeling of Vibronic Transitions and Stokes Shift in Poly(3-hexylthiophene) Aggregates: Insights into Molecular Ordering and Optical Behavior, PREPRINT (Version 1), Research Square (not peer reviewed). https://doi.org/10.21203/rs.3.rs-8633663/v1
Agumba, J. O., & Barasa, G. O. (2025). Computational Modeling of Vibronic Transitions and Stokes Shift in Poly(3-hexylthiophene) Aggregates: Insights into Molecular Ordering and Optical Behavior. Macromolecular Theory and Simulations - Manuscript Draft under Consideration (Manuscript No. MATS.202500113).
Antonate, W., Barasa, G. O., Agumba, J. O., Okoth, S. O., & Atego, E. (2025).
Novel synthesis and characterization of cellulose nanocrystals composites fabricated from rice husks. Advances in Chemical Engineering and Science, 15(1). https://doi.org/10.4236/aces.2025.151001
Okoth, S. O., Barasa, G. O., Agumba, J. O., Wanyonyi, A., & Atego, E. (2024).
Tailoring graphene for enhanced biosensing: Structural modifications and modeling of electronic and optical properties. Journal of Materials Science Research and Reviews, 7(4), 551-565. https://journaljmsrr.com/index.php/JMSRR/article/view/349
Manda, T., Barasa, G., Louis, H., Pembere, A., Agumba, J. O., & Irfan, A. (2024).
A data-guided approach for the evaluation of zeolites for hydrogen storage with the aid of molecular simulations. Journal of Molecular Modeling, 30(2), 43. https://doi.org/10.1007/s00894-024-05837-z
Barasa, G. O., Awino, C., Li, C., Agumba, J. O., Okoth, K. O., & Magero, D. (2022).
Indium-decorated nanoporous Ag as an efficient catalyst for enhanced CO₂ electroreduction.
Solid State Sciences, 129. https://doi.org/10.1016/j.solidstatesciences.2022.106916
Adem, J. A., Agumba, J. O., Barasa, G. O., & Ochung’, A. A. (2022).
Hydrolysis temperature-dependent structural, optical band gap, and the associated Urbach tail energy of cellulose nanocrystals fabricated from water hyacinth. European Journal of Applied Sciences, 10(1). https://doi.org/10.14738/aivp.101.11506
Adem, J. A., Agumba, J. O., Barasa, G. O., & Ochung’, A. A. (2022).
The role of acid concentration on band gap shrinkage in cellulose nanocrystals fabricated from water hyacinth. Journal of Material Sciences & Manufacturing Research. https://doi.org/10.47363/JMSMR/2022(3)123
Atego, E., Agumba, J. O., & Barasa, G. O. (2022). The signatures of acid concentration on the optical band gap and associated band tails of chitosan from shrimp for application in optoelectronic devices. Advances in Chemical Engineering and Science, 12(1), 1-12.
https://doi.org/10.4236/aces.2022.121001
Adem, J. A., & Agumba, J. O. (2021). The optical signatures of the temperature-controlled order-disorder conformational transition during the aggregation processes in poly(3-hexylthiophene-2,5-diyl) (P3HT) thin films. SunText Review of Material Science, 2(1), 108.
https://doi.org/10.51737/2766-5100.2021.00
Joseph, L., Agumba, J. O., & Keheze, F. M. (2021). The role of bio-extracted reduced graphene oxide in the crystallization kinetics of chitosan bio-polymer.
Materials Science and Manufacturing Research, 2(1), 1-4.
Mbilo, M., Agumba, J. O., & Mugwang’a, F. K. (2019). Correlation between the preparation methods and the structural morphologies of organometallic halide perovskite thin films.
Colloid and Surface Science, 4(1), 7-12.
Mbilo, M., Agumba, J. O., & Mugwang’a, F. K. (2019). Correlation between the morphology and the opto-electronic and electrical properties of organometallic halide perovskite (CH₃NH₃MH₃) thin films. Materials Research Express, 6, 076431.
Agumba, J. O. (2019). The role of solvents’ dielectric constants in delicate interplay between microstructure and optical properties of poly(3-hexylthiophene) thin films.
American Journal of Nanoresearch and Nanotechnology Research, 7(1), 1-13.
Joseph, S. L., Agumba, J. O., Mugwang’a, F. K., & Katana, G. G. (2019). Tuning the band gap energy of reduced graphene oxide using biopolymer chitosan for high power and frequency device applications. American Journal of Polymer Science and Engineering, 7(1), 1-12.
Hanif, J., Agumba, J. O., & Gabriel, K. G. (2018). The α- and β-relaxation processes of polymeric chitosan from squid gladii as revealed by dynamic mechanical analysis.
American Journal of Mechanical and Materials Engineering, 2(4), 40-45.
Agumba, J. O., & Adem, A. J. (2017). The interplay of the opto-electrical properties of cuprite and tenorite semiconductors for solar cell application. American Journal of Nano Research and Applications, 5(6), 81-86.
Rahimi, K., Botiz, I., Agumba, J. O., Motamen, S., Stingelin, N., & Reiter, G. (2014).
Light absorption of poly(3-hexylthiophene) single crystals. RSC Advances, 4(11), 1121.
Wang, Y., Heck, B., Schiefer, D., Agumba, J. O., Sommer, M., Wen, T., & Reiter, G. (2014).
Anisotropic photophysical properties of highly aligned crystalline structures of a bulky substituted poly(thiophene). ACS Macro Letters, 3(8), 881-885.
Brambilla, L., Tommasini, M., Botiz, I., Rahimi, K., Agumba, J. O., Stingelin, N., & Zerbi, G. (2014). Regio-regular oligo and poly(3-hexylthiophene): Precise structural markers from the vibrational spectra of oligomer single crystals.
Macromolecules, 47, 6730-6739.
Agumba, J. O., Okumu, J., & Karimi, P. (2012). LabVIEW run four-point probe device; Electrical characterization of semiconducting thin films made easy by four-point probe system controlled by LabVIEW. Lap Lambert Academic Publishing, Germany.
Agumba, J. O., Karimi, P. K., Okumu, J. O., & Njoroge, W. K. (2011). Design and fabrication of a simple four-point probe system for electrical characterization of thin films.
International Journal of Current Research, 3(7), 135-139.
Agumba, J. O., Gabriel, K. G., & Karimi, P. M. (2011). Towards virtual laboratories: A survey of LabVIEW-based conduction of science experiments via the internet with an illustrative consideration of remote control of an oscilloscope. International Journal of Current Research, 33(6), 123-127.