Valor nutritivo de silagens de bagaço de sorgo sacarino produzido na Beira Interior Sul

Pelas utilizações diversificadas que lhe estão associadas, o sorgo sacarino (Sorghum bicolor (L.) Moench) é uma cultura que tem vindo a receber assinalável atenção nos meios académicos. Apesar de em regra ser encarada como uma matéria-prima para a produção de biocombustíveis, nomeadamente bioetanol, a verdade é que a cultura e os seus subprodutos, designadamente a fração fibrosa da planta, apresentam a capacidade de ser utilizados com outros fins, nomeadamente na alimentação de ruminantes. O objetivo deste estudo foi comparar o valor nutritivo da silagem de bagaço de três cultivares de sorgo sacarino (Sugargraze, Sugar-T e 23402), com o valor nutritivo da silagem das mesmas cultivares processadas sem e com pré-fenação. Os resultados obtidos (% na MS) para as silagens de sorgo sacarino sem pré-fenação vs silagens de sorgo sacarino com pré-fenação vs silagens de bagaço de sorgo sacarino foram, respetivamente, os seguintes: MS 23,23% (±2,045) vs 26,52% (±1,233) vs 28,56% (±4,115) (P<0,05); PB 6,47% (±0,589) vs 5,96% (±0,164) vs 4,81% (±0,392) (P<0,05); GB 1,11% (±0,084) vs 1,01% (±0,096) vs 0,86% (±0,041) (P<0,05); NDF 55,05% (±2,613) vs 54,39% (±0,638) vs 74,53% (±1,283) (P<0,05); ADF 31,16% (±1,530) vs 31,76% (±0,725) vs 45,46% (±1,073) (P<0,05); ADL 3,22% (±0,497) vs 3,39% (±0,708) vs 4,87% (±0,474) (P<0,05); Cinzas 4,41% (±0,437) vs 4,33% (±0,489) vs 3,17% (±0,263) (P<0,05); Digestibilidade da MO 59,25% (±1,584) vs 59,40% (±1,708) vs 48,32% (±0,988) (P<0,05). Estes resultados levam-nos a concluir que as silagens de bagaço de sorgo sacarino apresentam valores de PB, GB e Digestibilidade da MO mais baixos (P<0,05) e valores de NDF, ADF e ADL mais elevados (P<0,05). No entanto, parecem apresentar valor nutritivo adequado para serem utilizadas na alimentação de ruminantes. Serão necessários estudos futuros para avaliar o efeito da utilização deste subproduto na produção de leite e carne

Static Hopfions in the extended Skyrme-Faddeev model

We construct static soliton solutions with non-zero Hopf topological charges to a theory which is an extension of the Skyrme-Faddeev model by the addition of a further quartic term in derivatives. We use an axially symmetric ansatz based on toroidal coordinates, and solve the resulting two coupled non-linear partial differential equations in two variables by a successive over-relaxation (SOR) method. We construct numerical solutions with Hopf charge up to four, and calculate their analytical behavior in some limiting cases. The solutions present an interesting behavior under the changes of a special combination of the coupling constants of the quartic terms. Their energies and sizes tend to zero as that combination approaches a particular special value. We calculate the equivalent of the Vakulenko and Kapitanskii energy bound for the theory and find that it vanishes at that same special value of the coupling constants. In addition, the model presents an integrable sector with an infinite number of local conserved currents which apparently are not related to symmetries of the action. In the intersection of those two special sectors the theory possesses exact vortex solutions (static and time dependent) which were constructed in a previous paper by one of the authors. It is believed that such model describes some aspects of the low energy limit of the pure SU(2) Yang-Mills theory, and our results may be important in identifying important structures in that strong coupling regime.Comment: 22 pages, 42 figures, minor correction

Retrofitting strategies for improving the energy and environmental efficiency in industrial furnaces: A case study in the aluminium sector

This study aims to analyse some of the most relevant issues that the energy intensive industry needs to face in order to improve its energy and environmental performance based on innovative retrofitting strategies. To this end, a case study based on the aluminium industry, as one of the most relevant within the European energy intensive industry has been thoroughly discussed. In particular, great efforts must be addressed to reduce its environmental impact; specifically focusing on the main stages concerning the manufacturing of an aluminium billet, namely alloy production, heating, extrusion and finishing. Hence, an innovative DC (direct current) induction technology with an expected 50% energy efficiency increase is used for retrofitting conventional techniques traditionally based on natural gas and AC (alternating current) induction. A life cycle assessment was applied to analyse three different scenarios within four representative European electricity mixes. The results reported reductions up to 8% of Green House Gases emissions in every country. France presented the best-case scenario applying only DC induction; unlike Greece, which showed around 150% increment. However, the suitability of the new DC induction technology depends on the electricity mix, the technological scenario and the environmental impact indicators. Finally, environmental external costs were assessed with comparison purposes to evaluate the increase of energy and environmental efficiency in existing preheating and melting industrial furnaces currently fed with natural gas

High-temperature PCM-based thermal energy storage for industrial furnaces installed in energy-intensive industries

The energy considered as waste heat in industrial furnaces owing to inefficiencies represents a substantial opportunity for recovery by means of thermal energy storage (TES) implementation. Although conventional systems based on sensible heat are used extensively, these systems involve technical limitations. Latent heat storage based on phase change materials (PCMs) results in a promising alternative for storing and recovering waste heat. Within this scope, the proposed PCM-TES allows for demonstrating its implementation feasibility in energy-intensive industries at high temperature range. The stored energy is meant to preheat the air temperature entering the furnace by using a PCM whose melting point is 885 °C. In this sense, a heat transfer model simulation is established to determine an appropriate design based on mass and energy conservation equations. The thermal performance is analysed for the melting and solidification processes, the phase transition and its influence on heat transference. Moreover, the temperature profile is illustrated for the PCM and combustion air stream. The obtained results prove the achievability of very high temperature levels (from 700 to 865 °C) in the combustion air preheating in a ceramic furnace; so corroborating an energy and environmental efficiency enhancement, compared to the initial condition presenting an air outlet at 650 °C

Associative study between handgrip strength, body composition and functional fitness in healthy elderlies

Poor handgrip strength is associated with [1,2]. As far as our understanding goes, [1] elderly’s disability independent elderlies trend to have high levels of quality of life . Even more, body composition and functional fitness presents [2] association with quality of life . OBJECTIVE: Thus, the aim of this study was to assess the associations between body composition, functional fitness and handgrip strength. METHODS: It was hypothesized that handgrip strength is associated with elderly’s body composition and functional fitness. Forty-eight elderly subjects (10 males and 38 females) with 69.61 (± 4.21) years old volunteered for this study. All the procedures were in accord to the Helsinki’s declaration regarding human research. The handgrip strength was measured with a digital mechanical dynamometer (CAMRY, New York, USA). The functional fitness was assessed by the functional fitness [3] test . The body composition was evaluated by a bioimpedance balance (Tanita, BC-601, Illinois, USA). The spearmen’s test allowed to assess the significant associations between the handgrip strength, functional fitness and body composition.info:eu-repo/semantics/publishedVersio

Compatible blends of thermoplastic starch and hydrolyzed ethylene-vinyl acetate copolymers

AbstractEthylene-vinyl acetate copolymer (EVA) with 19% of vinyl acetate and its derivatives modified by hydrolysis of 50 and 100% of the initial vinyl acetate groups were used to produce blends with thermoplastic starch (TPS) plasticized with 30wt% glycerol. The blends were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray diffraction, water absorption, stress–strain mechanical tests, dynamic mechanical analysis and thermogravimetric analysis. In contrast to the blends with unmodified EVA, those made with hydrolyzed EVA were compatible, as demonstrated by the brittle fracture surface analysis and the results of thermal and mechanical tests. The mechanical characteristics and water absorption of the TPS were improved even with a small addition (2.5wt%) of hydrolyzed EVA. The glass transition temperature rose with the degree of hydrolysis of EVA by 40 and 50°, for the EVA with 50 and 100% hydrolysis, respectively. The addition of hydrolyzed EVA proved to be an interesting approach to improving TPS properties, even when very small quantities were used, such as 2.5wt%

CERNAS: Current Evolution and Research Novelty in Agricultural Sustainability

Climate changes pose overwhelming impacts on primary production and, consequently, on agricultural and animal farming. Additionally, at present, agriculture still depends strongly on fossil fuels both for energy and production factors ,such as synthetized inorganic fertilizers and harmful chemicals such as pesticides. The need to feed the growing world population poses many challenges. The need to reduce environmental impacts to a minimum, maintain healthy ecosystems, and improve soil microbiota are central to ensuring a promising future for coming generations. Livestock production under cover crop systems helps to alleviate compaction so that oxygen and water can sufficiently flow in the soil, add organic matter, and help hold soil in place, reducing crusting and protecting against erosion. The use of organic plant production practices allied to the control of substances used in agriculture also decisively contributes to alleviating the pressure on ecosystems. Some of the goals of this new decade are to use enhanced sustainable production methodologies to improve the input/output ratios of primary production, reduce environmental impacts, and rely on new innovative technologies. This reprint addresses original studies and reviews focused on the current evolution and research novelty in agricultural sustainability. New developments are discussed on issues related to quality of soil, natural fertilizers, or the sustainable use of land and water. Also, crop protection techniques are pivotal for sustainable food production under the challenges of the Sustainable Development Goals of the United Nations, allied to innovative weed control methodologies as a way to reduce the utilization of pesticides. The role of precision and smart agriculture is becoming more pertinent as communication technologies improve at a rapid rate. Waste management, reuse of agro-industrial residues, extension of shelf life, and use of new technologies are ways to reduce food waste, all contributing to higher sustainability in food supply chains, leading to a more rational use of natural resources. The unquestionable role of bees as pollinators and contributors to biodiversity is adjacent to characterizing beekeeping activities, which in turn contributes, together with the valorization of endemic varieties of plant foods, to the development of local communities. Finally, the short circuits and local food markets have a decisive role in the preservation and enhancement of rural economies.info:eu-repo/semantics/publishedVersio