Search

Background: Salmonella enteritidis (SE) was the main cause of the pandemic of foodborne salmonellosis. The surface of eggs’ shells can be contaminated with this bacterium; however, washing them with sodium hypochlorite solution not only reduces their flavor but also heavily impacts the environment. An alternative to this is surface sterilization using low-energy electron beam. It is known that irradiation with 1 kGy resulted in a significant 3.9 log reduction (reduction factor of 10,000) in detectable SE on the shell. FAO/IAEA/WHO indicates irradiation of any food commodity up to an overall average dose of 10 kGy presents no toxicological hazard. On the other hand, the Food and Drug Administration has deemed a dose of up to 3 kGy is allowable for eggs. However, the maximum dose permitted to be absorbed by an edible part (i.e. , internal dose) is 0.1 Gy in Japan and 0.5 Gy in European Union. Materials and Methods: The electron beam (EB) depth dose distribution in the eggshell was calculated by the Monte Carlo method. The internal dose was also estimated by Monte Carlo simulation and experimentation. Results and Discussion: The EB depth dose distribution for the eggshells indicated that acceleration voltages between 80 and 200 kV were optimal for eggshell sterilization. It was also found that acceleration voltages between 80 and 150 kV were suitable for reducing the internal dose to ≤ 0.10 Gy. Conclusion: The optimum irradiative conditions for sterilizing only eggshells with an EB were between 80 and 150 kV.

Lithium iron phosphate (LiFePO 4 ) which is a promising cathode material for lithium-ion batteries requires particle size reduction, carbon coating and granulation to improve its electrochemical performances and increase the energy densities. In addition, their composite granules desire a porous structure in order to assist the penetration of liquid electrolyte. Here, we report a facile preparation of porous LiFePO 4 /C composite granules by a mechanical method using an attrition-type mill. By the mechanical treatment of starting materials, LiFePO 4 /C composite granules with an average pore size of 20–30 nm were synthesized in one-step process without atmosphere control and external heating. This simple mechanical technique does not require additional pore forming agents. According to the cell tests, a favorable cycle performance was exhibited.

A new approach to prepare LiFePO4/C composite granule as cathode for lithium-ion batteries has been demonstrated. The LiFePO4/C composite granule was synthesized by one-step mechanical process under ambient atmosphere without external heating. The obtained granule consisted of nano-sized primary particles. The new synthetic method which is achieved by using an attrition-type mill does not require an inert gas to prevent iron oxidation. The initial electrochemical performance of the LiFePO4/C composite granule was also investigated.

It is known that grain refinement improves balance of strength and ductility of materials. As a technique to obtain fine-grained microstructure, dynamic recrystallization can be used in industrial processes. The authors reported that fine grains appear beneath the surface of Al-Mg alloy sheet by high-speed rolling. In this study, rolling conditions to form fine recrystallized microstructure were investigated. AA5052 alloy sheets were rolled at 500 m/min, 1000 m/min or 2000 m/min with thickness reduction of 30%, 50% or 70% at 473 K, 523 K, 573 K or 623 K. After the rolling, the sheets were water-quenched immediately. It is found that the critical strain for dynamic recrystallization is very large. For example, when the sheets are rolled at 1000 m/min and 623 K, thickness reduction greater than 76% is required for dynamic recrystallization.