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Aims Fish is a potential source of vitamins and minerals and the cooking method an important role on the final content of nutrients in fish. The aim of this study was to the effects of different cooking methods on the heavy metals, fillet proximate composition and fatty acid composition of Roach (Rutilus rutilus) fillet.
Materials & Methods  Four cooking method such as deep frying, baking, steaming and microwave cooking were applied on fillet. Determination of the remaining heavy metals of the samples were carried out using atomic absorption.The proximate composition was assessed using the standard methods. To measure the composition of fatty acids, Gas-chromatography method (GC) was applied.
Findings The results showed that the all treated sample had significant decrease in moisture (frying) and ash (microwave) and significant increase in fat (frying) and protein (baking). The polyunsaturated fatty acids (PUFA), ω-3 fatty acids  as well as EPA/DHA content increased in baked samples in comparison to raw fish fillets and other coocked, although there were no significant was observed. The frying process caused a significant increase in lead concentration content. While, the steaming significantly decreased cadmium and lead heavy metals concentration in comparison to raw fish fillets and other cooked.
Conclusion Considering the increasing of PUFA and ω-3/ω-6 ratio in baked-cooked and losses of heavy metals in steamed, the baking and steaming are the best cooking method for a healthy consumption of Roach.

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Delamination is the most common failure mode in composite materials. It takes place in different modes, i.e. mode I, mode II or the combination of these modes. The present study is concerned with an investigation of mechanical and acoustic emission behavior of delamination. In this work, various lay-ups of glass/epoxy composite laminates have been used to study the delamination behavior when subjected to mode I, mode II and the mixed-mode I/II tests. First, the characterization of load-displacement curves of the specimens is done based on the AE parameters and mechanical responses and the curves were divided into three parts. The crack growth in the mode I was stable state and in the mixed-mode and mode II was unstable. In the next, interlaminar fracture toughness of the specimens, Gc, were measured using standard methodologies and acoustomechanical methodologies which is based on the mechanical behavior and AE information. It was found that the acoustomechanical method presents the lower limit of the interlaminar fracture toughness and agrees with the results that obtained from standard. The images were captured with Scanning electron microscope (SEM) from damage surfaces verifies the results that obtained from Acoustic emission.

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Sandwich composites are widely used in structural applications because of their appropriate mechanical properties and low strength/weight ratio. Delamination is common failure mode in these structures that lead to a reduction in strength and stiffness of composite. In this paper, using acoustic emission, initiation and propagation of delamination in sandwich composite specimens was investigated. The specimens were loaded under mode I loading. Then the characteristics of the signals related to different damage mechanisms were specified. The acoustic emission signals were classified based on their frequency ranges. Then the acoustic emission signals were recorded during the test specimens were processed using wavelet transform. Thus the percentage of energy in each components of the acoustic emission signal was specified. Each of these components has a certain frequency range corresponding to a damage mechanism. Thus the percentages of different damage mechanisms in each specimen were specified. The Scanning Electron Microscopy (SEM) was also employed to verify the results which were obtained from acoustic emission and wavelet transform method. The results showed acoustic emission is efficient tool for identification and separation of different damage mechanisms in sandwich structures.

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The AISI D2 steel is a high-chromium and high-carbon tool steel which has good mechanical properties such as high compressive strength and good through-hardening. Despite these advantages, fracture toughness of this steel is moderate. In this study, fracture toughness of AISI D2 steel was determined using Finite Element and Acoustic Emission methods. Selected steel (AISI D2 cold-work tool steel) was heat treated and tempered at different conditions. Then Compact testing specimens were prepared according to ASTM E399 standard and fracture toughness of the specimens was specified according to the standard method. The specimens were modeled in the commercial FE software (ABAQUS) and fracture toughness of the specimens was determined using FEM. Determination of fracture toughness using AE technique was carried out according to three methods: Acoustic Emission Energy Rate (AEER), Acoustic Emission Count Rate (AECR) and integral of sentry function. The results obtained from ASTM E399, Finite Element and Acoustic Emission methods were compared with each other. It was found that fracture toughness values which were obtained using AECR and integral of sentry function techniques are lower bound and the results obtained from FEM are upper bound values of the fracture toughness. Furthermore, fracture toughness values obtained using AEER were the most consistent with the results obtained from ASTM E399 standard method. Finally, it could be concluded that Acoustic Emission method can be used as a useful method for determination of fracture toughness of engineering materials.

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Despite the fact that fiber reinforced plastic composites have excellent mechanical properties, various failure mechanisms can be occurred in these materials. Delamination is the most common failure mode in laminated composites that can be occurred under quasi-static and fatigue loading conditions. The present study is concerned with the investigation of mechanical and Acoustic Emission (AE) behavior of delamination in glass/epoxy composites under mode I quasi-static and fatigue loading conditions. First, the unidirectional and woven specimens were subjected to mode I quasi-static loading. The behavior of the delamination in the specimens was investigated and interlaminar fracture toughness of the specimens was calculated. Then, according to the information that obtained from quasi-static loading, the similar specimens were subjected to the fatigue loading. The mechanical and AE behavior of the delamination under fatigue loading was investigated. A linear relationship was established between cumulative AE energy and fatigue crack growth and fatigue crack growth curve was predicted using the AE method. Then, energy release rate variations curve and fatigue crack growth rate diagram were predicted using AE method. The predicted results by AE have a good compatibility with the visually based data that recommended by standard. The results indicate that, the AE method has good applicability for health monitoring of composite structures that subjected to quasi-static and fatigue loading conditions.

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The laminated composites have many advantages such as high specific strength and specific stiffness. Despite of these advantages, they are prone to different damage mechanisms. This paper focuses on quantification of damage mechanisms in standard Open-Hole Tensile (OHT) laminated composites using Acoustic Emission (AE) and Finite Element Method (FEM). These damages include three main mechanisms, matrix cracking, fiber/ matrix debonding and fiber breakage. To this aim, OHT tests were carried out. The specimens fabricated from two types of glass/epoxy composite materials with [0]5S lay-up and [90]5S lay-up. AE accompanied with wavelet-based approach was then used to detect and quantify damage mechanisms of the specimens. FE analysis based on Hashin criteria was then utilized to simulate the damage mechanisms in the specimens and to validate the AE-wavelet based results. The comparison of applied methods show that the results of the AE-wavelet based approach are in very good agreement with the FEM results. Finally, it was concluded that the AE method has a good applicability to determine the damage mechanisms in laminated composite structures and to predict the remaining life-time of the structure.