An improved encapsulation method of a sensing element for a cement-based piezoelectric sensor used in civil engineering structure was developed and some tests were carried out for validating this method. The cement-ba...An improved encapsulation method of a sensing element for a cement-based piezoelectric sensor used in civil engineering structure was developed and some tests were carried out for validating this method. The cement-based piezoelectric sensor of this kind is mainly used in concrete structure due to its compatibility with concrete, and the encapsulation method of its sensing element is important to the effectiveness and accuracy of the transfer of the stress from concrete to the sensing element. The sensor′s measurement error of the previous encapsulation method, which was induced by the area of the encapsulation material and the inherent difference of Young′s modulus between cement and encapsulation material, was analyzed theoretically using parallel model. In the improved method, the error is minimized by decreasing the area of the encapsulation material and changing the configuration of the cement and piezoelectric material in the sensor. Two sensors made by the previous and improved methods were embedded in two prisms respectively and the prisms were compressed on Material Test System. Through the comparison of the measurement errors of the two sensors, the improved method was evaluated. The test results show that the improved encapsulation method is effective and feasible.展开更多
The increasing demand for prolonging food shelf life and inhibiting food spoilage and pathogenic microorganisms lead to development of novel biopreservatives and conservation methods. Antimicrobial peptides derived fr...The increasing demand for prolonging food shelf life and inhibiting food spoilage and pathogenic microorganisms lead to development of novel biopreservatives and conservation methods. Antimicrobial peptides derived from microorganisms like bacteriocins are considered as a major alternative to the application of chemical preservatives in food products. Direct addition of purified antimicrobial peptides into food matrix results in reduced antibacterial activity due to the interaction of peptides with food components. Nano- or microencapsulation process can protect biopreservatives against many adverse conditions and controlled release of the agents efficiently prevent microbial contamination and food spoilage. This review focuses on the most frequently used chemical, physical and mechanical encapsulation methods for various antimicrobial bacteriocins including liposome entrapment, coacervation, emulsification, spray-drying, and vibrating technology. The most recent applications of nano- or microencapsulated antimicrobial bacteriocins with emphasis on nisin and pediocin in various food products like dairy, meat products and fruit juice have been discussed.展开更多
基金Supported by Hong Kong Research Grant Council to HKUSTunder grant HKUST6212/O2ENational Science Fund forDistinguished Young Scholars of China(No.50425824).
文摘An improved encapsulation method of a sensing element for a cement-based piezoelectric sensor used in civil engineering structure was developed and some tests were carried out for validating this method. The cement-based piezoelectric sensor of this kind is mainly used in concrete structure due to its compatibility with concrete, and the encapsulation method of its sensing element is important to the effectiveness and accuracy of the transfer of the stress from concrete to the sensing element. The sensor′s measurement error of the previous encapsulation method, which was induced by the area of the encapsulation material and the inherent difference of Young′s modulus between cement and encapsulation material, was analyzed theoretically using parallel model. In the improved method, the error is minimized by decreasing the area of the encapsulation material and changing the configuration of the cement and piezoelectric material in the sensor. Two sensors made by the previous and improved methods were embedded in two prisms respectively and the prisms were compressed on Material Test System. Through the comparison of the measurement errors of the two sensors, the improved method was evaluated. The test results show that the improved encapsulation method is effective and feasible.
文摘The increasing demand for prolonging food shelf life and inhibiting food spoilage and pathogenic microorganisms lead to development of novel biopreservatives and conservation methods. Antimicrobial peptides derived from microorganisms like bacteriocins are considered as a major alternative to the application of chemical preservatives in food products. Direct addition of purified antimicrobial peptides into food matrix results in reduced antibacterial activity due to the interaction of peptides with food components. Nano- or microencapsulation process can protect biopreservatives against many adverse conditions and controlled release of the agents efficiently prevent microbial contamination and food spoilage. This review focuses on the most frequently used chemical, physical and mechanical encapsulation methods for various antimicrobial bacteriocins including liposome entrapment, coacervation, emulsification, spray-drying, and vibrating technology. The most recent applications of nano- or microencapsulated antimicrobial bacteriocins with emphasis on nisin and pediocin in various food products like dairy, meat products and fruit juice have been discussed.
