27 research outputs found

    Species-Specific Discrimination of Insect Meals for Aquafeeds by Direct Comparison of Tandem Mass Spectra

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    Insect protein has the potential to become a sustainable feed ingredient for the rapidly growing aquaculture industry. In the European Union, insect derived protein is placed under the same legislation as processed animal proteins (PAP). It is therefore of interest to develop methods for regulatory use, which unambiguously identify the species origin of insect-based ingredients. We performed (i) total protein quantification of insect samples using the traditional nitrogen-to-protein conversion factor of 6.25 and the sum of anhydrous amino acids, (ii) quantitative amino acid profiling and (iii) high-throughput tandem mass spectrometry to describe and differentiate 18 different commercial-grade insect meal samples derived from Hermetia illucens (8), Tenebrio molitor (5), Alphitobius diaperinus (3) and Acheta domesticus (2). In addition, we investigated and compared different protein extraction and digestion protocols for proteomic analysis. We found that irrespective of sample preparation, shotgun proteomics in combination with direct spectral comparison were able to differentiate insect meal according to their taxonomic classification. The insect specific spectral libraries created in the present work can in future be used to develop more sensitive targeted methods of insect PAP identification and quantification in commercial feed mixtures

    ENERGY EFFICIENCY OF A PHOTOVOLTAIC CELL BASED THIN FILMS CZTS BY SCAPS

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    <p>In the overall context of the diversification of the use of natural resources, the use of renewable energy including solar photovoltaic has become increasingly indispensable. As such, the development of a new generation of photovoltaic cells based on CuZnSnS4 (CZTS) looks promising. Cu2ZnSnS4 (CZTS) is a new film absorber, with good physical properties (band gap energy 1.4-1.6 eV [01] with a large absorption coefficient over 10<sup>4</sup> cm<sup>-1</sup>). Indeed, the performance of these cells exceeded 30% in recent years.In the present paper, our work based on modeling and numerical simulation, we used SCAPS to study the performance of solar cells based on Cu2ZnSnS4 (CZTS) and thus evaluate the electrical efficiency η for typical structures of ZnO / i- ZnO / CdS / CZTS and ITO / ZnO / CdS / CZTS. Furthermore, the influence of the change of CdS by ZnSe buffer layer was treated in this paper.</p><strong></strong><em></em

    Study of Mechanical Properties and Precipitation Reactions in Low Copper Containing Al-Mg-Si Alloy

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    The scope of this work is to investigate the precipitation of two Al-Mg-Si alloys with and without Cu and excess Si by using the differential scanning calorimetry (DSC), transmission electron microscopic (TEM), Vickers hardness measurement and X-ray diffraction. The analysis of the DSC curves found that the excess Si accelerate the precipitation and the alloy contain the excess Si and small addition of copper has higher aging-hardness than that of free alloy (without excess Si and Cu) at the same heat treatment condition. The sufficient holding time for the precipitation of the β'' phase was estimated to be 6 hours for the alloy aged at 100°C and 10 hours for the alloy aged at 180°C. The low Copper containing Al-Mg-Si alloy gives rise to the forming a finer distribution of β (Mg2Si) precipitates which increases the hardness of the alloy. In order to know more about the precipitation reactions, concern the peaks on the DSC curve transmission electron microscopy observation were made on samples annealed at temperatures (250°C, 290°C and 400°C) just above the corresponding peaks of the three phases β'', β' and β respectively

    Impact of dietary glutamate and glycine on growth and nutrient utilization in rainbow trout (Oncorhynchus mykiss)

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    A feeding trial was conducted to test the effect of dietary glutamate and glycine supplementation on growth potential, nutritional utilization and digestion, and energy metabolism of rainbow trout (Oncorhynchus mykiss). Four isonitrogenous and isolipidic diets (2 × 2 factorial design) were formulated with glutamate (Glu) and glycine (Gly) as the main factors. The protein source consisted mainly of black soldier fly larvae meal (40% inclusion in all diets) for its low-level content of glutamate and glycine. Triplicate groups of rainbow trout (30 fish/tank with mean initial body weight of 87.5 g ± 0.9) were restrictively fed by hand twice a day for 6 weeks. Dietary Glu and Gly supplementation did not affect feed intake, specific growth rate, or the feed conversion ratio. Whole body protein, lipid, amino acid and fatty acid composition were also unaffected by the supplementation of Glu and Gly in the diets. Dietary Gly supplementation increased the apparent digestibility of amino acids. Furthermore, supplementation with Gly, increased the concentration of serine, glycine, tryptophane, tyrosine and citrulline, while supplementation with Glu in the diets increased the concentration of hydroxy-proline and β-alanine in the serum of rainbow trout. Both dietary Glu and Gly supplementation improved the digestibility of the fatty acids. The expression of genes involved in the hepatic bile acid synthesis (e.g., apical sodium dependent bile acid transporter and organic solute transporter) were affected by supplementation of Gly in the diets. In general, this study showed that dietary supplementation with Gly and Glu improved the nutrient digestibility in rainbow trout

    Logisticians’ ethical decision-making: does the psychological safety team matter?

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    This study mobilizes the concept of team psychological safety to study the link between ethical decision-making and the feeling of safety perceived within their team. This research examines a logistician’s ethical judgments depending on a moral intensity dimension. Based on a population of 260 European professional logisticians, the study uses 12 scenarios that have been designed to describe logistical situations. A first sample of 123 purchasers was given a low moral intensity questionnaire and a second group, composed of 137 other purchasers, answered another questionnaire with a high moral intensity. The findings reveal that the moral intensity, clear direction, team leader coaching and team learning behaviors intensity have a positive impact on judgment of 2 scenarios : social consensus and temporality
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