Rice husks, which can be considered as an agricultural waste, are produced every year in South Gonder, Ethiopia. Precipitated silica is commonly used as reinforcing filler in rubber industry, in the present study an effort has been attempted to replace commercial silica commonly used in natural rubber industries with rice husk ash silica (RHAS). Silica was extracted from RHA by using alkaline extraction followed by acid precipitation. The synthesized RHAS was characterized by AAS, BET, DSC, FTIR, and XRD. RHAS was then used as reinforcing filler in natural rubber. The curing characteristics of natural rubber products filled with RHAS resulted a smaller scorch time which caused a premature vulcanization than the commercial silica filled rubber composite. Overall mechanical properties like hardness, young’s modulus, abrasion resistance of rubber products reinforced with RHAS was better than commercial silica filled rubber composite.

Amongst the surface treatment technologies to emerge in the last few decades, UV-C radiation surface treatment is widely used in food process industries for the purpose of shelf life elongation, bacterial inactivation, and stimulation. However, the short wave application is highly dose-dependent and induces different properties of the product during exposure. Mechanical properties of the agricultural products and their derivatives represent the key indicator of acceptability by the end-user. This paper surveys the recent findings of the influence of UV-C on the stress response and physiological change concerning the mechanical and textural properties of miscellaneous agricultural products with a specific focus on a potato tuber. This paper also reviewed the hormetic effect of UV-C triggered at a different classification of doses studied so far on the amount of phenolic content, antioxidants, and other chemicals responsible for the stimulation process. The combined technologies with UV-C for product quality improvement are also highlighted. The review work draws the current challenges as well as future perspectives. Moreover, a way forward in the key areas of improvement of UV-C treatment technologies is suggested that can induce a favorable stress, enabling the product to achieve self-defense mechanisms against wound, impact, and mechanical damage.

The current experimental work aimed at developing PCC through two major process steps: dissolution and precipitation, using raw materials domestically available as SL, which are intensively used in construction inputs. The pH level was the decisive parameter used to determine the time required to complete the dissolution and carbonation processes during precipitation. The optimal pH levels were found to be 13 for dissolution and 7.1 for precipitation, respectively. The produced PCC was characterized based on chemical analysis, crystallinity, and morphology, showing an increment of CaCO₃ content exceeding 99%, sharper crystal peaks, and predominantly calcite PCC. The compatibility of the PCC was assessed by incorporating 25%, 50%, 75%, and 100% of PCC with commercial filler, followed by selected mechanical tests, such as stress at yield, density, and elongation at break. The results indicated that mixing ratios of 25%, 50%, and 75% of PCC with the commercial filler met the standards, with stress at a yield above 45 MPa and density within the range of 1.35 to 1.46 g/cm³. However, complete substitution slightly lowered these properties. Nevertheless, the elongation at break was acceptable at all treatment levels.

The present experimental study aimed at investigating the effect of certain calcination temperature zones on the corrosion prevention performance of biomass. Na₂SiO₃ was synthesized from rice husk ash (RHA) calcined at 500°C, 550°C, and 600°C. The prepared RHA samples were characterized in terms of surface functional groups, chemical compositions, and crystallinity confirming the presence of the Si-O-Si (Silanol) group, an abundant constituent of SiO_2, and the amorphous nature of the silica, respectively. The major step in the synthesis of Na₂SiO₃ involves a reaction of sodium hydroxide with RHA (SiO₂). The effect of inhibitor dose and immersion time on corrosion rate and inhibition efficiency was investigated on mild steel prepared strips. The interaction of the parameter that results in maximum corrosion efficiency of 95.41% was recorded at 30 ml of inhibition dose and 144 hours of immersion time in a sample prepared from 600°C calcined RHA. Isotherm study resulted in best fit on Temkin isotherm model for all samples, a kinetic model was best represented by pseudo-second-order for 500°C and 600°C thermally treated samples and pseudo-zero-order kinetic model for 550°C. The thermodynamic model revealed important parameters including activation energy, enthalpy, and entropy confirming the endothermic process, feasibility, and energy barrier formed on the metal surface. Generally, the effect of low-temperature extracted Na₂SiO₃ showed a significant effect on the buildup of protective layer which is determined by the amount of silica content and reactivity.