1,721,061 research outputs found
Marco Fabbri - Angelo Trotta, Una scuola-collegio di età augustea. L'insula II di Velia
No full textBalty Jean-Charles. Marco Fabbri - Angelo Trotta, Una scuola-collegio di età augustea. L'insula II di Velia. In: L'antiquité classique, Tome 62, 1993. pp. 580-581
Marco Fabbri, Angelo Trotta. — Una scuola- collegio di età augustea. L'insula II di Velia, 1989. (Archaeologia Perusina, 7. Archaeologina, 90)
No full textGros Pierre. Marco Fabbri, Angelo Trotta. — Una scuola- collegio di età augustea. L'insula II di Velia, 1989. (Archaeologia Perusina, 7. Archaeologina, 90). In: Revue des Études Anciennes. Tome 94, 1992, n°3-4. pp. 521-522
Marco Fabbri, Angelo Trotta. — Una scuola- collegio di età augustea. L'insula II di Velia, 1989. (Archaeologia Perusina, 7. Archaeologina, 90)
No full textGros Pierre. Marco Fabbri, Angelo Trotta. — Una scuola- collegio di età augustea. L'insula II di Velia, 1989. (Archaeologia Perusina, 7. Archaeologina, 90). In: Revue des Études Anciennes. Tome 94, 1992, n°3-4. pp. 521-522
Modelling volume change and deformation in food products/processes: An overview
Full text linkVolume change and large deformation occur in different solid and semi-solid foods during processing, e.g., shrinkage of fruits and vegetables during drying and of meat during cooking, swelling of grains during hydration, and expansion of dough during baking and of snacks during extrusion and puffing. In addition, food is broken down during oral processing. Such phenomena are the result of complex and dynamic relationships between composition and structure of foods, and driving forces established by processes and operating conditions. In particular, water plays a key role as plasticizer, strongly influencing the state of amorphous materials via the glass transition and, thus, their mechanical properties. Therefore, it is important to improve the understanding about these complex phenomena and to develop useful prediction tools. For this aim, different modelling approaches have been applied in the food engineering field. The objective of this article is to provide a general (non-systematic) review of recent (2005–2021) and relevant works regarding the modelling and simulation of volume change and large deformation in various food products/processes. Empirical-and physics-based models are considered, as well as different driving forces for deformation, in order to identify common bottlenecks and challenges in food engineering applications.Fil: Purlis, Emmanuel. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; ArgentinaFil: Cevoli, Chiara. Università di Bologna; ItaliaFil: Fabbri, Angelo. Università di Bologna; Itali
Heat transfer finite element model of fresh fruit salad insulating packages in non-refrigerated conditions
Full text linkThe quality of many foods is significantly affected by temperature fluctuations that can occur during distribution and transport. Packaging materials can help to shield the product from temperature variation by increasing the heat transfer resistance. Thermal insulation power is influenced by several factors, such as material, geometry, and degree of contact between materials. To maintain the cool chain of fruit salad with syrup during the transportation (temperature less than 5 °C), thermal insulation effect of different packaging materials was investigated. A parametric analysis using a finite element model able to describe the heat transfer inside the containers, on varying packaging material (expanded polystyrene: EPS, and air), geometry, dimension, and boundary conditions, was developed and validated. Good agreement was obtained between numerical and experimental results (R2 up to 0.98). The effectiveness of the insulation configurations was evaluated by determining the time taken for the temperature to rise the critical value of 5 °C. Results showed that insulating performance of the air is better than EPS. This is realistic only taking into account insulation layer less than 0.013 m. From a practical point of view, an EPS packaging could result stronger compared to a packaging characterised by an insulating air layer. For the same EPS insulation thickness, product temperature exponentially decreases with the volumetric capacity (R2 = 0.99)
Rheological parameters estimation of non-Newtonian food fluids by finite elements model inversion
No full textThe knowledge of fluid food rheological properties plays an important role in process engineering. Unfortunately, characterization of non-Newtonian fluids requires a notable effort in terms of time and resources. As a consequence, the aim of this research was to set up an method, based on the combination of the inversion of a simple finite element model and a laboratory measurement, carried on with a simplified tool. Although the method has a more general applicability, for illustrative purpose, it is here mainly shown with reference to power-law rheological model and two different materials (tara gum mixture and dough of water and flour). To measure the rheological parameters, the square of distance between simulated and experimental data was considered as an objective function, and some well-known optimization algorithms were tested. In order to verify the feasibility of the method, the experimental rheological characterization of the considered materials were carried out using a rotational rheometer. The calculated rheological parameter values were comparable with those obtained by traditional procedure (mean percentage error 6.47 ± 5.57). The most efficient optimization algorithm, in terms of iterations number, computational speed and minimum of the objective function, was the Levenberg-Marquardt one, but even other tested algorithms drove to similar final results (maximum difference of 18% between the optimized k and n values). The results demonstrated also that the precision of the calculated rheological parameters does not depend on the initial parameter values. In the light of the obtained results, the method could represent a feasible technique and well suited for various rheological models and viscosity range of food materials. Moreover, the method could be susceptible to some development by an industrial point of view being possible to hypothesize the development of an integrated automatic instrument, equipped with finite element software, useful both for laboratory and industrial purposes
Estimation of semolina dough rheological parameters by inversion of a finite elements model
Full text linkThe description of the rheological properties of food material plays an important role in food engineering. Particularly for the optimisation of pasta manufacturing process (extrusion) is needful to know the rheological properties of semolina dough. Unfortunately characterisation of non-Newtonian fluids, such as food doughs, requires a notable time effort, especially in terms of number of tests to be carried out. The present work proposes an alternative method, based on the combination of laboratory measurement, made with a simplified tool, with the inversion of a finite elements numerical model. To determine the rheological parameters, an objective function, defined as the distance between simulation and experimental data, was considered and the well-known Levenberg-Marqard optimisation algorithm was used. In order to verify the feasibility of the method, the rheological characterisation of the dough was carried also by a traditional procedure. Results shown that the difference between measurements of rheological parameters of the semolina dough made with traditional procedure and inverse methods are very small (maximum percentage error equal to 3.6%). This agreement supports the coherence of the inverse method that, in general, may be used to characterise many non-Newtonian materials
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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