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Journal : tech journal of engineering science

Rigour over R²: Defensible Practice in BET Surface Area and Adsorption Kinetic Analysis Zik Ken Ebikebina; Eyere Emagbetere; Benjamin Ufuoma Oreko; Chinedum Ogonna Mgbemena
Tech : Journal of Engineering Science Vol 2 No 2 (2026): IOT is a Future? Nice.....
Publisher : Yayasan Penelitian dan Pengabdian Masyarakat Sisi Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.69836/tech.v2i2.929

Abstract

This comprehensive review synthesizes the theoretical foundations, core physical assumptions, and standardized experimental protocols required for defensible Brunauer–Emmett–Teller (BET) surface area determination and adsorption kinetic analysis. The work addresses critical methodological gaps in porous materials characterization, focusing on recurring pitfalls such as conflating mathematical goodness-of-fit (R²) with true physical mechanism and applying fixed relative-pressure windows or linearized regressions without regard to data error structure. A systematic review and critical evaluation framework was employed, compiling authoritative guidelines, IUPAC technical recommendations, ISO 9277:2022 standards, and interlaboratory consensus studies published between 2015 and 2026. The evaluation reveals that unstandardized sample degassing protocols and arbitrary pressure-interval selections can induce discrepancies exceeding 30% in reported BET surface areas. Furthermore, algebraic linearization of non-linear kinetic frameworks (pseudo-first-order, pseudo-second-order, Elovich, and Weber–Morris intraparticle diffusion) severely distorts error distributions, resulting in biased rate constants and flawed mechanistic interpretations. To establish rigorous characterization standards, BET analysis must objectively implement Rouquerol consistency criteria, select appropriate probe gases (e.g., argon at 87 K for micropores or krypton for low-area solids), and incorporate complementary porosity techniques such as t-plot or NLDFT kernels. For kinetic modeling, non-linear regression must be prioritized alongside multi-metric statistical evaluations (such as chi-squared and residual sum of squares) corroborated by independent spectroscopic or structural evidence. The study concludes that strict adherence to standardized reporting guidelines, complete metadata disclosure, and FAIR data principles using Adsorption Information File (AIF) repositories are essential for ensuring international comparability and academic integrity, particularly when evaluating locally sourced bio-derived adsorbents and novel functional porous materials for environmental and energy applications.
Investigating the Viscosity-Pressure Drop Trade-Off and Hydrodynamic Penalties in Nanofluid-Enhanced Cooling Loops Victor Chimdike Obinani; David Samuel Olusegun; Chinedum Ogonna Mgbemena
Tech : Journal of Engineering Science Vol 2 No 2 (2026): IOT is a Future? Nice.....
Publisher : Yayasan Penelitian dan Pengabdian Masyarakat Sisi Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.69836/tech.v2i2.931

Abstract

This research explores the non-linear thermofluidic trade-offs in a thermal management loop for solid-state thermoelectric cooling (TEC) applications in the presence of nanoparticles. Although nanofluids convey a significant advantage in the convective heat transfer, the presence of a significant increase in dynamic viscosity of the nanofluid considerably limits its application, leading to an increase in pumping power. A stable Nanofluid of alumina-water ( ) with alpha phase alumina was synthesized using the two-step method with fixed ratio (1:1) using the stabilizer of Sodium Dodecylbenzene Sulfonate (SDBS). The Face-Centered Central Composite Design (CCD) was used to run 27 different parametric runs with a multi-variable experimental matrix. Three diameters of the nanoparticles (10 nm, 30 nm and 50 nm), three volume fractions (2.0%, 4.0% and 5.0% vol.), and three volumetric flow rates (0.5 L/min, 1.2 L/min and 2.4 L/min) were selected to encompass the laminar, transitional, and turbulent flow regimes. The performance of the system was determined by measuring the hot and cold junction temperature ( , ), system COP ( ), microchannel friction factors (fnf) and drop in core line pressure (ΔP). To minimize error, theoretical reduction models were used, such as Corcione's viscosity correlation and Leong's stationary nanolayer thermal reduction model. System level multi-objective optimization at a 2.36L/min flow rate was able to define a clear "sweet spot" envelope. The best combination is obtained when using 29.60 nm nanoparticles with a volume fraction of 4.18% vol., which leads to a minimum dynamic viscosity of 0.000891 , a well-controlled pressure drop of 10.52 Pa and maximized Performance Evaluation Criterion (PEC = 1.065). This empirical boundary shows that targeted particle nesting can be an effective way to avoid the large degradation of hydrodynamic performance at the hot-side thermal resistance limit (hydrodynamic degradation >5.0% vol.) and the clogging of the cooling loops by particles (clogging >5.0% vol.), and gives a clear mathematical recipe for reducing the hot-side thermal resistance without the hydrodynamic and clogging degradation.