GRASS UTILIZATION IN GROWING FINISHING BÍSARO PIGS (85-107 KG). PERFORMANCE AND CARCASS COMPOSITION

The use of different quantities of vegetables, forages or fresh grass as fodder for growing-finishing pigs is an important factor of the northern Portugal traditional system. The increasing development of swine production in outdoor systems, extensive and organic production, turns to upcoming natural diets, in which grass performs a significant part. With regard to this, some investigation has been made concerning the use of fibre-rich feed ingredients in pig nutrition. Metabolic effects of its ingestion are analysed concerning different sights (economical, social, environmental and physiological ones). The aim of this work was to study the effects of grass utilization in the diets on performances of finishing Bísaro pigs. A total of 22 pigs (16 castrated males and 6 females) was housed outdoor and fed ad libitum (37 – 85 kg live weight) with a growing diet and then transferred to an indoor system (with free access to an outdoor area) for 49 days, according to 3 different treatments: 100% concentrate (C), 75% concentrate + ad libitum grass (CE75), 50% concentrate + ad libitum grass (CE50). The grass was supplied and its intake registered on a daily basis. Every 14 days, the pigs were weighted and their back fat (P2 in vivo) measured. After slaughter (average weight of 107 kg LW), yield and ½ left carcass characteristics were controlled. During the outdoor growing phase, the ADG was 513 g/day. During the indoor finishing phase, the increase grass intake was proportional to the reduction of concentrate in the diet. The ADG (g) and the fat deposition (P2 cm) were significantly different (P<0,05) in the 3 treatments (ADG: C=641, CE75=467, CE50=356 and: C=11,4, CE75=+9,5, CE50=+6,2). The empty body weight (kg) was also proportional to the intake of concentrate (C=116,2; CE75=107,7; CE50=102,2). Comparatively to the weight of the body parts, pigs that had higher intake of grass and lower of concentrate showed a higher % of shoulder (P<0,05; C=20,4, CE75=21,7, CE50=22,2) and the pH45min of CE carcasses was significantly higher (P<0,05). As a conclusion, concentrate substitution for grass showed a slower growing rate, thinner carcasses and a high technological quality. Neverthelles variability (CV %) of the productive parameters at the end of this study were higher in the treatments that included grass: live weight (C= 10,5%; C75=10,7%; C50=14,3%), finishing ADG (C=24%; C75=37%, C50=42%), and final fat (C=37%; C75=32%, C50=52%). These values suggest that the utilization of fibrous feeds in growing-finishing swine may be one of the possible explanations of the more heterogeneous products and carcasses found in the traditional or extensive systems, common users of fibrous feeds in the carcass finishing phase

Domus tutor: A CBR tutoring agent for student support

The changes introduced by the Bologna process in the educational paradigm, moving from a lecturer centered paradigm to a learner centered paradigm, involves a more supported learning process based on learning outcomes and the adoption of new pedagogical methodologies. In this paper we present our strategy of integration of tutoring agents in learning environments, using the features of intelligent tutoring systems adapted to collaborative environments. The Domus Tutor agent is the face of the adaptive learning environment that integrates Learning Design, groupware and collaborative work technologies. The adaptation of the system to the learner profile is based on case-based reasoning methodology; witch is one of the major reasoning paradigms in artificial intelligence.- (undefined

Guest Editorial

[Excerpt] The 13th European Meeting on Ferroelectricity (EMF-13) has welcomed participants to Portugal for the first time in the history of these meetings. EMF-13 was held, from 28th June to 3rd July 2015, in the Faculty of Sciences of the University of Porto. The conference has been organized by the group “Polarized Materials and Functional Nanostructures” of the Materials Physics Institute, IFIMUP-IN, (IN - Institute of Nanoscience and Nanotechnology), in the Physics and Astronomy Department of the Faculty of Sciences, University of Porto. The Local Organizing Committee included members of the Universities of Porto, Minho and Aveiro. Three hundred and sixty six attendees from thirty four countries in Europe, Asia, America, and Africa were fully registered at EMF-13 meeting. These participants took active part in the sessions and informal discussions that had place along the 5 days of the meeting. Five plenary talks, given by Vladimir Fridkin, David Field, Annette Bussmann-Holder, Manuel Bibes, and Stephen Rowley, sixty invited talks, and one hundred thirty five oral contributions covered a wide number of topics ranging from basic research to new characterization techniques or novel applications of ferroelectrics and related materials. Complementary to the program of the meeting, a one day satellite workshop on “Inelastic scattering in ferroic materials” took place on Sunday 28th. [...]info:eu-repo/semantics/publishedVersio

A Review of the Power Converter Interfaces for Switched Reluctance Machines

The use of power electronic converters is essential for the operation of Switched Reluctance Machines (SRMs). Many topologies and structures have been developed over the last years considering several specific applications for this kind of machine, improving the control strategies, performance range, fault-tolerant operation, among other aspects. Thus, due to the great importance of power electronic converters in such applications, this paper is focused on a detailed review of main structures and topologies for SRM drives. The proposed study is not limited to the classic two-level power converters topologies dedicated to the SRMs; it also presents a review about recent approaches, such as multilevel topologies and based on impedance source network. Moreover, this review is also focused on a new class of topologies associated to these machines, namely the ones with fault-tolerant capability. This new category of topologies has been a topic of research in recent years, being currently considered an area of great interest for future research work. An analysis, taking into consideration the main features of each structure and topology, was addressed in this review. A classification and comparison of the several structures and topologies for each kind of converter, considering modularity, boost capability, number of necessary switches and phases, integration in the machine design, control complexity, available voltage levels and fault-tolerant capability to different failure modes, is also presented. In this way, this review also includes a description of the presented solutions taking into consideration the reliability of the SRM drive.info:eu-repo/semantics/publishedVersio

A universal approach for drainage basins

Drainage basins are essential to Geohydrology and Biodiversity. Defining those regions in a simple, robust and efficient way is a constant challenge in Earth Science. Here, we introduce a model to delineate multiple drainage basins through an extension of the Invasion Percolation-Based Algorithm (IPBA). In order to prove the potential of our approach, we apply it to real and artificial datasets. We observe that the perimeter and area distributions of basins and anti-basins display long tails extending over several orders of magnitude and following approximately power-law behaviors. Moreover, the exponents of these power laws depend on spatial correlations and are invariant under the landscape orientation, not only for terrestrial, but lunar and martian landscapes. The terrestrial and martian results are statistically identical, which suggests that a hypothetical martian river would present similarity to the terrestrial rivers. Finally, we propose a theoretical value for the Hack's exponent based on the fractal dimension of watersheds, $\gamma=D/2$. We measure $\gamma=0.54 \pm 0.01$ for Earth, which is close to our estimation of $\gamma \approx 0.55$. Our study suggests that Hack's law can have its origin purely in the maximum and minimum lines of the landscapes.Comment: 20 pages, 6 Figures, and 1 Tabl

Fault detection and diagnosis technique for a SRM drive based on a multilevel converter using a machine learning approach

Trabalho apresentado em 12th International Conference on Renewable Energy Research and Applications (ICRERA 2023), 29 augusto-1 setembro 2023, Oshawa, CanadaSRM drives based on multilevel converters is now a solution well accepted due to their interesting features like extended voltage range and capability to fault tolerance. However, one aspect that is fundamental to ensure fault tolerance or preventive maintenance is the fault detection and diagnosis of failures in power semiconductors. In this way, in this paper it is presented a new diagnostic method for the failure of those semiconductors in asymmetric neutral point clamped converters. The proposed method will be based on the development of specific patterns that are associated to each semiconductor and fault type. The procedures presented here are based on the image identification of the currents patterns in the multilevel converter that allow the identification of distinct fault type. The pattern recognition system uses visual-based efficient invariants features for continuous monitoring of multilevel converter The proposed method will be verified through several tests in which were used a simulation tool and an experimental prototype.N/

Pathophysiological mechanisms of renal fibrosis: a review of animal models and therapeutic strategies

Chronic kidney disease (CKD) is a long-term condition in which the kidneys do not work correctly. It has a high prevalence and represents a serious hazard to human health and estimated to affects hundreds of millions of people. Diabetes and hypertension are the two principal causes of CKD. The progression of CKD is characterized by the loss of renal cells and their replacement by extracellular matrix (ECM), independently of the associated disease. Thus, one of the consequences of CKD is glomerulosclerosis and tubulointerstitial fibrosis caused by an imbalance between excessive synthesis and reduced breakdown of the ECM. There are many molecules and cells that are associated with progression of renal fibrosis e.g. angiotensin II (Ang II). Therefore, in order to understand the biopathology of renal fibrosis and for the evaluation of new treatments, the use of animal models is crucial such as: surgical, chemical and physical models, spontaneous models, genetic models and in vitro models. However, there are currently no effective treatments for preventing the progression of renal fibrosis. Therefore it is essential to improve our knowledge of the cellular and molecular mechanisms of the progress of renal fibrosis in order to achieve a reversion/elimination of renal fibrosis.This work was supported in part by a project grant from the Fundação para a Ciência e Tecnologia, Ministério da Educação, Portugal (grant no. SFRH/PROTEC/67576/2010).info:eu-repo/semantics/publishedVersio

Ação do ácido quetomélico nas alterações hematológicas induzidas pela redução de 5/6 de massa renal em ratos

A doença renal crónica está associada com o desenvolvimento de anemia devido principalmente à diminuição da produção de eritropoetina. O ácido quetomélico (AC) é um potente inibidor seletivo da farnesil transferase e, desta forma, inibe as vias de sinalização que levam à progressão da fibrose renal. Assim, o objectivo deste trabalho foi o de estudar os efeitos do tratamento crónico com o AC nas alterações hematológicas induzidas pela redução de 5/6 de massa renal (RMR). Neste estudo foram utilizados 70 ratos machos da estirpe Wistar. Uma semana após a redução cirúrgica de 5/6 de massa renal, os animais foram divididos em quatro grupos experimentais: CO: animais em que se simulou a cirurgia e sem tratamento; CO+AC: animais em que se simulou a cirurgia e tratados com o AC; RMR: animais com RMR e não tratados; RMR+AC: animais com RMR e tratados com o AC. O tratamento foi administrado por via intraperitoneal, durante seis meses. Para o estudo hematológico procedeu-se à contagem manual, em câmara de Neubauer, do número total de eritrócitos e de leucócitos, à determinação do microhematócrio, à contagem diferencial de leucócitos e à estimativa do número total de plaquetas no esfregaço de sangue corado com Diff-Quick. Nos grupos RMR e RMR+AC observou-se um aumento estatisticamente significativo (p<0.01) do número total de eritrócitos, do microhematócrito, do número total de leucócitos e das plaquetas, em relação aos grupos CO e CO+AC. Deste modo, os resultados deste estudo sugerem que em ratos Wistar com doença renal crónica, o tratamento com o AC, durante seis meses, não diminui a gravidade da anemia, da leucocitose e da trombocitose induzidas pela redução de 5/6 de massa renal

A Fault Diagnosis Scheme Based on the Normalized Indexes of the Images eccentricity for a Multilevel Converter of a Switched Reluctance Motor Drive

Trabalho apresentado em ICRERA 2022, 18-21 setembro 2022, Istambul, TurquiaThis paper addresses the fault detection and diagnosis of a fault in the switches of the Switched Reluctance Machine (SRM) power electronic converter. Due to the advantages of using multilevel converters with these machines, a fault detection and diagnosis algorithm is proposed for this converter. The topology under consideration is the asymmetric Neutral Point Clamped (ANPC), and the algorithm was developed to detect open and short circuit faults. The proposed algorithm is based on an approach that discriminates eccentricity of the images formed by the converter voltages. This discrimination is realized through the development of normalized indexes based on the entropy theory. Besides the different fault type the algorithm is also able to detect the transistor under fault. The possibility to implement the proposed approach will be verified through simulation tests.N/

On the width of the last scattering surface

We discuss the physical effects of some accelerated world models on the width of the last scattering surface (LSS) of the cosmic microwave background radiation (CMBR). The models considered in our analysis are X-matter (XCDM) and a Chaplygin type gas. The redshift of the LSS does not depend on the kind of dark energy (if XCDM of Chaplygin). Further, for a Chaplygin gas, the width of the LSS is also only weakly dependent on the kind of scenario (if we have dark energy plus cold dark matter or the unified picture).Comment: 10 pages, 1 figure, 2 tables, accepted to IJMP