The effect of liquid smoking of fillets of trout (Salmo gairdnerii) on sensory,microbiological and chemical changes during chilled storage

The storage time at 4 ± 1 °C of liquid smoked fillets of trout (Salmo gairdnerii) produced with a new smoking technique, using a combination of liquid smoke and steaming at 2 bar pressure for 30, 45 and 60 min, was studied. Maximum total viable counts (TVC) were reached after 25 days in the samples processed for 30 min and after 48 days in those processed for 45 and 60 min. However, panellists rejected the samples long after maximum TVC was observed. The increase of TVC was also confirmed using a particle size analyser, indicating a possible direct detection of microbial growth. A reduction of about 50% in the C22:6n − 3/C16:0 ratio was found across the whole period of storage, indicating lipid oxidation. The hypoxanthine/inosine (Hx/Ino) ratio showed a good relationship with both TVC and sensory results. Thus, when the Hx/Ino ratio was higher than 1.3, the products had reached their maximum acceptable TVC and were approaching their rejection time by the panellists, indicating that the Hx/Ino ratio is a good indicator of the shelf-life of smoked products of trout (S. gairdnerii).     

A CFD methodology for the design of sedimentation tanks in potable water treatment: Case study: The influence of a feed flow control baffle

Computational fluid dynamics simulations are employed to assess the effect of adding a vertical baffle at the feed section of a full-scale sedimentation tank for the improvement of solids settling in potable water treatment. A general CFD-based simulation strategy is developed based on the specific features and conditions met in practice for potable water treatment. The linearity of the particle conservation equations allows separate calculations for each particle size class – but performed for all classes of interest – leading to the uncoupling of the CFD problem from a particular inlet particle size distribution. The usually unknown and difficult to be measured particle density is found by matching the theoretical to the easily measured experimental total settling efficiency. The proposed strategy is computationally much more efficient than the corresponding strategies used for the simulation of wastewater treatment. This work compares simulations from a standard and a baffle-equipped tank. It is found that the baffle decreases the inlet recirculation zone and enhances the settling of solids by directing them towards the bottom of the tank with high velocities. It is noteworthy that even small differences in the particle velocity can cause large changes in the percent of settled particles; in this work, the overall solids removal efficiency increased when using the baffle from 90.4 to 98.6% leading to a reduction of the effluent solids concentration of approximately 85%.     

Correction to: Automatic stress analysis from facial videos based on deep facial action units recognition

Pattern Analysis and Applications - A correction to this paper has been published: 10.1007/s10044-021-01012-9     

A study of in situ plated tin-film electrodes for the determination of trace metals by means of square-wave anodic stripping voltammetry

This work is a study of tin-film electrodes (SnFEs) for the determination of trace metals by means of square-wave anodic stripping voltammetry (SWASV). SnFEs represent a new promising type of environment-friendly electrodes but their analytical performance has not been explored in detail so far. Initially, the operational parameters for the simultaneous determination of Cd(II) and Zn(II) on in situ plated SnFEs on different substrates were thoroughly investigated. Using the selected conditions, at a preconcentration time of 120 s the limits of detection were 0.7 μg l⁻¹ for Cd and 0.9 μg l⁻¹ for Zn and the percent relative standard deviations were 4.2% for Zn(II) and 3.6% for Cd(II) at the 20 μg l⁻¹ level (n = 8). Subsequently, a study was conducted to investigate the utility of SnFEs as sensors for the determination of other metals, including those with oxidation potentials close to, or more positive than, the oxidation potential of Sn (Tl(I), Pb(II), Cu(II)). Finally, the SnFEs were successfully applied for the determination of Pb(II) and Zn(II) in tap water.     

A compound real option and AHP methodology for evaluating ICT business alternatives

After the liberalization of information and communication technology (ICT) markets many potential providers have appeared. Thus, business complexity, for ICT decision makers, has increased. In this paper, we focus on the problem of selecting the optimal business evolution path for ICT, focusing on the broadband technology (BT) field. Traditional quantitative cost–benefits analysis, such as net present value (NPV), is by no means sufficient for capturing the complexity of the problem in its entire. Researchers suggest the real options (ROs) for valuating ICT investments. However, RO models are strictly quantitative and very often ICT investments may also contain qualitative factors, which cannot be quantified in monetary terms. In addition, ROs analysis itself brings to the “surface” some factors that can be more efficiently treated qualitatively. We combine the ROs and analytic hierarchy process (AHP) into a common decision analysis framework providing an integrated multicriteria model, called ROAHP, for prioritizing ICT business alternatives. The proposed model is applied to a real life BT business case, showing how it can be formulated and solved.     

Experimental investigation of R-ratio effects on fatigue crack growth of adhesively-bonded pultruded GFRP DCB joints under CA loading

A series of fatigue experiments was performed in order to investigate the effect of the R-ratio on the fatigue/fracture behavior of adhesively-bonded pultruded GFRP double cantilever beam joints. Constant amplitude fatigue experiments were carried out under displacement control with a frequency of 5 Hz in ambient laboratory conditions. Three different R-ratios were applied: R = 0.1, R = 0.5 and R = 0.8. The crack length was determined by means of crack gages and a dynamic compliance method. The dominant failure mode was a fiber-tear failure that occurred in the mat layers of the pultruded laminates. The depth of the crack location significantly affected the energy dissipated for the fracture under cyclic loading. Short-fiber and roving bridging increased the fracture resistance during crack propagation. Fatigue crack growth curves were derived for each R-ratio and each observed crack path location. The fatigue threshold and slope of the fatigue crack growth curve significantly increased with increased R-ratio.     

Spatiotemporal analysis of human activities for biometric authentication

This paper presents a novel framework for unobtrusive biometric authentication based on the spatiotemporal analysis of human activities. Initially, the subject’s actions that are recorded by a stereoscopic camera, are detected utilizing motion history images. Then, two novel unobtrusive biometric traits are proposed, namely the static anthropometric profile that accurately encodes the inter-subject variability with respect to human body dimensions, while the activity related trait that is based on dynamic motion trajectories encodes the behavioral inter-subject variability for performing a specific action. Subsequently, score level fusion is performed via support vector machines. Finally, an ergonomics-based quality indicator is introduced for the evaluation of the authentication potential for a specific trial. Experimental validation on data from two different datasets, illustrates the significant biometric authentication potential of the proposed framework in realistic scenarios, whereby the user is unobtrusively observed, while the use of the static anthropometric profile is seen to significantly improve performance with respect to state-of-the-art approaches.     

Natural Origin Lycopene and Its “Green” Downstream Processing

Lycopene is an abundant natural carotenoid pigment with several biological functions (well-known for its antioxidant properties) which is under intensive investigation in recent years. Lycopene chemistry, its natural distribution, bioavailability, biological significance, and toxicological effects are briefly outlined in the first part of this review. The second, major part, deals with various modern downstream processing techniques, which are assessed in order to identify promising approaches for the recovery of lycopene and of similar lipophilic compounds. Natural lycopene is synthesized in plants and by microorganisms, with main representatives of these two categories (for industrial production) tomato and its by-products and the fungus Blakeslea trispora, respectively. Currently, there is a great deal of effort to develop efficient downstream processing for large scale production of natural-origin lycopene, with trends strongly indicating the necessity for “green” and mild extraction conditions. In this review, emphasis is placed on final product safety and ecofriendly processing, which are expected to totally dominate in the field of natural-origin lycopene extraction and purification.