Agric & Bioresources Engineering
Permanent URI for this collectionhttp://197.211.34.35:4000/handle/123456789/145
Agric & Bioresources Engineering
Browse
4 results
Search Results
Item Drying kinetics, Energy requirement, Bioactive composition, and Mathematical Modeling of Allium Cepa Slices(2022-09-24) Asoiro, Felix; Simeon, Meshack Imologie; Azuka, Chinenye E.; Harami, SolomonItem Effect of floral locations on physicochemical and thermal honey bee properties.(AgricEngInt: CIGR Journal, 2022-03-30) Asoiro, Felix; Simeon, Meshack Imologie; Azuka, CEThe effects of floral location on the physicochemical and thermal parameters of honey bee samples from Enugu North senatorial zone were evaluated. For physicochemical properties, a 14×5×10 completely randomized design (CRD) with a total of 700 observations (14 physicochemical properties as responses × 5 levels of floral location as treatment × 10 replications) was conducted. For thermal properties, a 3×5×10 CRD with a total of 150 observations (3 thermal properties as responses × 5 levels of floral location as treatment × 10 replications) was also conducted. Floral location had significant effects (P≤0.05) on viscosity, electrical conductivity, sugar content, free acidity, ash content, moisture content, density, pH, colour, thermal heat conductivity and thermal heat diffusivity except, fructose/glucose (F/G) ratio and specific heat capacity. Viscosity of honey decreased as temperature increased with samples from Igbo-Eze South more viscose than those from other floral locations. Fructose had the highest mean value (35.26 g/100g), followed by glucose (31.92 g/100g) and sucrose (1.47 g/100g). All samples were generally acidic and of very high quality standard as Udenu, Igbo-Eze South and Nsukka honeys were adjudged extra white in colour, while Igbo-Eze North and Igbo-Etiti were white honey. Values for thermal heat conductivity and thermal heat diffusivity were 0.44 W m-1oC-1 and 3.51 m2s-1; 0.43 W m-1oC-1 and 3.84 m2s-1; 0.44 W m-1C-1 and 2.43 m2s-1; 0.44 W m-1oC-1 and 2.84 m2s-1; and 0.45 W m-1oC-1 and 2.69 m2s-1 for Igbo- Eze North, Udenu, Igbo-Eze South, Igbo-Etiti and Nsukka respectively. Honey is a promising food rich in essential minerals. Knowledge of its physicochemical and thermal properties is inevitable to facilitate its postharvest processing.Item Electrochemical evaluation of different polymer binders for the production of carbon-modified stainless-steel electrodes for sustainable power generation using a soil microbial fuel cell.(Chemical Engineering Journal Advances-Elsevier, 2022-01-11) Simeon, Meshack Imologie; Herkendell, Katharina; Pant, Deepak; Freitag, RuthIn this study, four different polymeric binders - polytetrafluoroethylene (PTFE), two-component epoxy (epoxy), polyvinyl alcohol (PVA), and polyvinylidene fluoride (PVDF) - were used to fabricate a surface-modified stainless-steel electrode. The polymeric binders were used to bond highly conductive carbon-black to a stainless-steel support using a simple fabrication method. The electrodes' performance in sustainable power generation was tested in a soil microbial fuel cell (SMFC). PTFE showed the fastest and best initial response in no-load operation, reaching a voltage of 370 mV after 7 days, compared to epoxy, PVA, and PVDF, which had 163, 151.7, and -26.7 mV, respectively. Electrochemical measurements showed that epoxy and PVDF have similar redox potentials when operated as anode and cathode in an SMFC. Evaluation of the long-term performance of the binders showed that epoxy gave 2.2-, 3.4-, and 4.9-fold higher performance than PVDF, PTFE, and PVA, respectively, under intermittent polarization. Although PVDF did not perform well in open circuits, it produced the highest current density in continuous operation with external loads. The most sustained performance was obtained with epoxy. This study has shown that epoxy can be a suitable and eco-friendly substitute for other binders using a simple fabrication method to produce high-performance anodes and cathodes for sustainable bioelectricity generation with a SMFC.Item Performance evaluation of microbial fuel cells for bioelectricity generation: influence of potential scan‑rate and real‑time external load(International Journal of Environmental Science and Technology-Springer Nature, 2024-01-19) Simeon, Meshack Imologie; Gbabo, Agidi; Feitag, RuthThe electrochemical performance of microbial fuel cells is conventionally assessed through linear sweep voltammetry at predefined potential scan rates. Nevertheless, this approach frequently falls short in representing the long-term behavior of microbial fuel cells under actual external loads, highlighting the need for a standardized evaluation method incorporating both linear sweep voltammetry and external loads. To address this gap, this study evaluates the performance of single-chamber microbial fuel cells under different loads and scan rates. The MFCs were tested with external loads of 1200, 470, and 270 Ω, derived from maximum power points of polarization sweeps at scan rates of 0.1, 0.5, and 1 mV/s at two operational phases. Power estimates at these scan rates were 61.96, 87.88, and 166.68 mW/m² at current densities of 116.5, 229.6, and 403 mA/m², respectively. In the initial two hours, average power densities with 1200, 470, and 270 Ω were 73 ± 16.7, 36.3 ± 42, and 88.5 ± 120.1 mW/m², respectively. Over the long term, the fuel cells under constant loading with resistance estimated at 0.1 mV/s showed average power 73.7% and 89.1% higher than those with resistances estimated at 0.5 mV/s and 1 mV/s, respectively, indicating that higher scan rates lead to overestimation of power. Although initially underestimated, the 0.1 mV/s scan rate more accurately reflected the true long-term performance of the fuel cells. This study emphasizes the importance of using appropriate scan rates for linear sweep voltammetry to obtain realistic long-term performance estimates of microbial fuel cells under real-time loads.