4,450 research outputs found
Simultaneously prediction of sheep and goat carcass composition and body fat depots using in vivo ultrasound measurements and live weight
The present study established multiple linear regression models using two ultrasound in vivo measurements (at lumbar and sternal regions, with different real-time ultrasonography machines and probes) and live weight, to predict simultaneously carcass composition and body fat depots of different breeds of sheep and goat. This study is important for the small ruminant industry, considering the feasibility of using the ultrasound methodology in field conditions, as well as an online system of the carcass evaluation. The multiple linear regression models were obtained by selecting the best subset of variables between using the in vivo measurements (raw variables), their second degree and interactions, evaluated in terms of prediction performance using cross-validation âK-foldsâ and validated by a test group. Overall, high accuracy (adj R2) was obtained from the linear relationship between predicted and experimental values of the group test for each of the nine dependent variables, with values varying between adj R2 0.88 and 0.98.The authors are grateful to Laboratory of Carcass and Meat Quality
of Agriculture School of Polytechnic Institute of Bragança âCantinho do
Alfredoâ. The authors are members of the CYTED network HEALTHY
MEAT (119RT0568).info:eu-repo/semantics/publishedVersio
Dynamic capabilities: Antecedents and implications for firms' performance
Purpose: This paper aims to explore a new causal link between learning, market and entrepreneurial orientations and firms' performance by introducing dynamic capabilities and competitive advantages as mediator variables. Design/methodology/approach: The mediating role of dynamic capabilities and competitive advantages is tested using a sample of 1,190 Portuguese firms, and structural equation models. Findings: It is shown that dynamic capabilities mediate the relationship between the three orientationsâlearning, market and entrepreneurialâand competitive advantages of differentiation and cost leadership, and both competitive advantages lead to firm's performance. It is also shown that learning orientation is an antecedent of market orientation and entrepreneurial orientation. Practical implications: This research shows that firm's performance depends on the capacity of firms to learn, innovate, be proactive, take risks and collect the best market data. Indeed, by optimizing the internal management and knowledge dissemination, firms will develop a set of capabilities and competitive advantages that lead to an appropriate response to market challenges. Originality/value: This study tests the relationship between strategic orientations and firm's performance by taking the mediating effects of dynamic capabilities and competitive advantages into account. This research was conducted in Portugal.info:eu-repo/semantics/acceptedVersio
Intramuscular fat prediction using color and image analysis of bĂsaro pork breed
This work presents an analytical methodology to predict meat juiciness (discriminant semi-quantitative analysis using groups of intervals of intramuscular fat) and intramuscular fat (regression analysis) in Longissimus thoracis et lumborum (LTL) muscle of BĂsaro pigs using as independent variables the animal carcass weight and parameters from color and image analysis. These are non-invasive and non-destructive techniques which allow development of rapid, easy and inexpensive methodologies to evaluate pork meat quality in a slaughterhouse. The proposed predictive supervised multivariate models were non-linear. Discriminant mixture analysis to evaluate meat juiciness by classified samples into three groupsâ0.6 to 1.1%; 1.25 to 1.5%; and, greater than 1.5%. The obtained model allowed 100% of correct classifications (92% in cross-validation with seven-folds with five repetitions). Polynomial support vector machine regression to determine the intramuscular fat presented R2 and RMSE values of 0.88 and 0.12, respectively in cross-validation with seven-folds with five repetitions. This quantitative model (modelâs polynomial kernel optimized to degree of three with a scale factor of 0.1 and a cost value of one) presented R2 and RSE values of 0.999 and 0.04, respectively. The overall predictive results demonstrated the relevance of photographic image and color measurements of the muscle to evaluate the intramuscular fat, rarther than the usual time-consuming and expensive chemical analysis.Work included in the Portuguese PRODER research Project BISOPORCâPork
extensive production of BĂsara breed, in two alternative systems: fattening on concentrate vs. chesnut.
The CIMO authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for
financial support by national funds FCT/MCTES to CIMO (UIDB/00690/2020) and are members of
the Healthy Meat network by (CYTED-119RT0568). The CECAV authors are thankful to the project
UIDB/CVT/00772/2020 funded by the Foundation for Science and Technology (FCT, Portugal). The
authors are grateful to Laboratory of Carcass and Meat Quality of Agriculture School of Polytechnic
Institute of Bragança âCantinho do Alfredoâ.UIDB/CVT/00772/2020info:eu-repo/semantics/publishedVersio
Prediction of Friction Stir Welding effects on AA2024-T3 plates and stiffened panels using a shell-based finite element model
Manufacturing-induced effects significantly affect in-service behaviour of welded structures, such as integrally stiffened panels for aeronautic applications. Being a complex phenomenon with several variables involved, the assessment of the effects coming from welding usually relies on numerical simulations. Here, a novel shell-based finite element model is proposed to accurately simulate the transient thermal fields and stress-strain distributions resulting from friction stir welding (FSW) processes. The capability of the model to predict (i) residual stresses, (ii) material softening and (iii) geometric distortion of the welded parts is assessed by the modelling and simulation of FSW applied on aluminium integrally stiffened panels
Teores de nutrientes em mudas clonais de Coffea canephora BRS Ouro Preto em diferentes volumes de tubetes.
Objetivou-se com este trabalho avaliar o desenvolvimento de mudas de cafeeiros C. canephora ?Conilon ? BRS Ouro Preto? em diferentes volumes de tubetes. o experimento foi instalado no Campo Experimental da Embrapa RondĂŽnia, no municĂpio de Ouro Preto do Oeste. o experimento foi conduzido com cinco tratamentos e uma testemunha adicional. os tratamentos foram constituĂdos por cinco volumes de tubetes (50, 100, 170, 280 e 400 cmÂł).Organizado por: Henrique Nery Cipriani; Alaerto Luiz Marcolan; Fernando Machado Pfeifer: Alexandre Martins AbdĂŁo dos Passos; Marcelo Curitiba EspĂndula; Angelo Mansur Mendes
Modelling of friction stir welding and its influence on the structural behaviour of aluminium stiffened panels
This work deals with the modelling and numerical simulation of aluminium stiffened panels, assembled by means of friction stir welding (FSW) operations, and subjected to compressive loads that can catastrophically induce buckling (global or local) unstable modes and, subsequently, overall failure. Due to their geometrical complexity, added to localized thermo-mechanical effects that typically come from joining by welding, approximation methods such as the Finite Element Method are typically used in such nonlinear analyses, having proved to be useful to designers focused on the prediction of the behaviour (before and post buckling) of such structures. Being grounded on previous contributions from the authors, the present paper aims to bring a number of innovative aspects to the current state of the art by considering in the developed models the simultaneous influence of residual stress fields, material softening effects and geometrical imperfections. Doing so, it is possible to infer about the singular and combined influence of these effects in the overall structural performance of stiffened panels, building up a useful and comprehensive methodology for design stages
Numerical simulation of the buckling behaviour of stiffened panels: Benchmarks for assessment of distinct modelling strategies
This work deals with the effective modelling and simulation of the behavior of stiffened panels, when subjected to compressive (buckling) loads. Within the Finite Element Method, two numerical strategies are compared, namely the Riks method and the displacement incremental control method, including damping effects. The capabilities and limitations of both approaches are explored for two distinct benchmarks: a panel with a blade stiffener, and a panel with a T shaped stiffener. In both cases, material (plasticity) and geometrical (large displacements) nonlinearities are considered, together with a modelling strategy based on shell elements. Following previous works of the authors, each panel accounts for initial geometric imperfections coming from friction stir welding joining operations. The paper shows a number of considerations that must be undertaken when choosing between one of the two modelling strategies. Both benchmarks involve a number of challenges from the point of view of modelling unstable structural behaviors, and therefore the proposed benchmarks can represent a valid set of case studies in the understanding of the capabilities of current numerical simulation codes
- âŠ