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1.
Micromachines (Basel) ; 10(5)2019 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-31052249

RESUMO

This paper presents a novel approach of annular concentric split rings microelectromechanical resonators with tether configuration to reduce anchor loss and gives very high-quality factor (Q) 2.97 Million based on FEA (Finite Element Analysis) simulation. The operating frequencies of these resonators are 188.55 MHz to 188.62 MHz. When the proposed SR (square rectangle) hole shaped one dimensional phononic crystal (1D PnC), and two dimensional phononic crystal (2D PnC) structure consist of very wide and complete band gaps is applied to novel design rings MEMS resonators, the quality factor (Q) further improved to 19.7 Million and 1750 Million, respectively, by using the finite element method. It is also observed that band gaps become closer by reducing the value of filling fraction, and proposed SR PnC gives extensive peak attenuation. Moreover, harmonic response of ring resonator is verified by the perfect match layers (PML) technique surrounded by resonators with varying width 1.5λ, and 3λ effectively reduce the vibration displacement.

2.
Ultrason Sonochem ; 21(3): 984-90, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24373787

RESUMO

Enzymatic browning and microbial growth lead to quality losses in apple products. In the present study, fresh apple juice was thermosonicated using ultrasound in-bath (25 kHz, 30 min, 0.06 W cm(-3)) and ultrasound with-probe sonicator (20 kHz, 5 and 10 min, 0.30 W cm(-3)) at 20, 40 and 60°C for inactivation of enzymes (polyphenolase, peroxidase and pectinmethylesterase) and microflora (total plate count, yeast and mold). Additionally, ascorbic acid, total phenolics, flavonoids, flavonols, pH, titratable acidity, (°)Brix and color values influenced by thermosonication were investigated. The highest inactivation of enzymes was obtained in ultrasound with-probe at 60°C for 10 min, and the microbial population was completely inactivated at 60°C. The retention of ascorbic acid, total phenolics, flavonoids and flavonols were significantly higher in ultrasound with-probe than ultrasound in-bath at 60°C. These results indicated the usefulness of thermosonication for apple juice processing at low temperature, for enhanced inactivation of enzymes and microorganisms.


Assuntos
Bebidas , Manipulação de Alimentos/métodos , Qualidade dos Alimentos , Temperatura Alta , Malus , Sonicação , Ácido Ascórbico/metabolismo , Hidrolases de Éster Carboxílico/metabolismo , Catecol Oxidase/metabolismo , Malus/enzimologia , Peroxidases/metabolismo
3.
J Agric Food Chem ; 60(29): 7111-20, 2012 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-22732007

RESUMO

The effects of sodium selenite (SS) and selenium yeast (SY) alone and in combination (MS) on the selenium (Se) content, antioxidant enzyme activities (AEA), total antioxidant capacity (TAC), and oxidative stability of chicken breast meat were investigated. The results showed that the highest (p < 0.05) glutathione peroxidase (GSH-Px) activity was found in the SS-supplemented chicken breast meat; however, SY and MS treatments significantly increased (p < 0.05) the Se content and the activities of catalase (CAT), total superoxide dismutase (T-SOD), and TAC, but decreased (p < 0.05) the malondialdehyde (MDA) content at 42 days of age. Twelve days of storage at 4 °C decreased (p < 0.05) the activity of the GSH-Px, but CAT, T-SOD, and TAC remained stable. SY decreased the lipid oxidation more effectively in chicken breast meat. It was concluded that SY and MS are more effective than SS in increasing the AEA, TAC, and oxidative stability of chicken breast meat.


Assuntos
Antioxidantes/análise , Galinhas/metabolismo , Dieta/veterinária , Carne/análise , Selênio/administração & dosagem , Selenito de Sódio/administração & dosagem , Animais , Disponibilidade Biológica , Catalase/análise , Galinhas/crescimento & desenvolvimento , Suplementos Nutricionais , Conservação de Alimentos , Glutationa Peroxidase/análise , Humanos , Valor Nutritivo , Saccharomyces cerevisiae , Selênio/análise , Selênio/farmacocinética , Sensação , Selenito de Sódio/farmacocinética , Superóxido Dismutase/análise
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