http://hdl.handle.net/10174/164 Sun, 05 Apr 2026 21:02:06 GMT 2026-04-05T21:02:06Z http://hdl.handle.net/10174/37615 Title: Influence of co-applying biochar, compost and inorganic nitrogen on growth, nutrient uptake and nitrates and riboflavin content of turnips Authors: Machado, R.M.A.; Alves-Pereira, I.; Velez, D.; Grilo, A.; Ferreira, R. Abstract: In the pursuit of sustainable vegetable farming methods, the effect of co-application of compost, biochar, and a reduced amount of inorganic nitrogen on growth and the quality of turnips was studied in a greenhouse pot experiment. The experiment was carried out with five treatments: unfertilized soil, compost + biochar, compost + 0.5g N/pot, biochar + 0.5 g N/pot, compost + biochar + 0.5 g N/pot. Municipal organic compost (150 g/pot), collected selectively, and biochar (15 g/pot) were mixed with the top 10cm of soil. Nitrogen, as ammonium nitrate nitrogen (16.9% NO3–N and 16.7% NH4-N), was applied weekly in equal amounts. The experiment was arranged in a randomized complete block design with five replicate pots per treatment. All treatments led to an increase in shoot and root macronutrient and micronutrient uptake relative to unfertilized soil. The higher nutrient uptake by shoots and roots occurred in treatments C + 0.5 g N/pot and C + B + 0.5g N/pot. In these treatments, the fresh (root and shoot) of the plant were similar. Shoot nitrate level increased with nitrogen addition but was not affected by the presence of biochar, compost, or compost plus biochar. Root and shoot riboflavin decreased with nitrogen application but were also not affected by the application of compost, biochar, or compost and biochar. The findings of this work indicate that the combined application of compost, biochar, and nitrogen maintains fresh yield and quality, and contributes to carbon sequestration. Tue, 24 Sep 2024 23:00:00 GMT http://hdl.handle.net/10174/37615 2024-09-24T23:00:00Z http://hdl.handle.net/10174/37612 Title: Enhancing the Sustainability of Growing Media: Exploring Pine Bark as a Perlite Substitute in Coir-Based Substrates for Lettuce Cultivation. Authors: Machado, R.A.M.; Dias, G.; Alves-Pereira, I.; Ferreira, R. Abstract: Increasing the sustainability of growing media constituents is currently a priority. This study aimed to evaluate whether pine bark can replace perlite in coir-based substrates. For this purpose, an experiment was carried out with four treatments: two coir-based mixes, one containing perlite and the other pine bark, and two electrical conductivities of nutrient solution (1.5 ± 0.2 and 2.5 ± 0.2 dS m-1). Lettuce plants (Lactuca sativa L. cv. Godzilla) were grown in Styrofoam boxes filled with growing media containing, by volume, 80% coir, 12% compost, and 8% of either perlite or pine bark. The pine bark led to an increase in the electrical conductivity and bulk density of the mix. The presence of pine bark in the mix did not influence the effect of nutrient solution concentration on the average values of pH and electrical conductivity of the leachate. The electrical conductivity of leachate increased with the nutrient solution ion concentration. The presence of pine bark in the mix did not affect the shoot nutrient content of N, P, K, Ca, and Mg. Shoot iron and boron content were higher in plants grown with pine bark-containing substrates. Shoot N and P increased with the increase in ion concentration in the nutrient solution. The presence of pine bark relative to perlite did not affect the influence of nutrient solution concentration on photosynthetic pigment contents, shoot dry weight, or yield (head fresh weight). This indicates the potential of pine bark as a sustainable alternative to perlite without compromising lettuce production. Tue, 24 Sep 2024 23:00:00 GMT http://hdl.handle.net/10174/37612 2024-09-24T23:00:00Z http://hdl.handle.net/10174/28053 Title: Caracterización de morteros asociados con el Sistema hidráulico de la villa romana Horta da Torre (Fronteira, Portugal) Authors: Valdez, Dulce; Moita, Patrícia; Galacho, Cristina; Carneiro, André Abstract: El objetivo principal de este proyecto es la caracterización de morteros con propiedades hidráulicas utilizados en las instalaciones de almacenamiento de agua, la comprensión de sus técnicas de producción y la posible fuente de sus materias primas en el contexto histórico de la villa romana “Horta da Torre”, ubicada en el municipio de Fronteira, Portugal. Para lograrlo, será necesario el uso de una metodología multianalítica para determinar su composición mineralógica cualitativa y semi-cuantitativa, así como la caracterización de su morfología y composición elemental, siendo estos soportados por el uso de Microscopía Óptica(MO; OM), Microscopio Electrónico de Barrido-Espectrometría de Energía de Dispersión (MEBEED;SEM-EDS), Difracción de Rayos X (DRX; XRD), Termogravimetría (TR; TGA-DTA), Ataque con ácido clorhídrico y caracterización granulométrica. Mon, 30 Sep 2019 23:00:00 GMT http://hdl.handle.net/10174/28053 2019-09-30T23:00:00Z http://hdl.handle.net/10174/26474 Title: New Proton Conductive Heteroaromatic Bisphosphonic acid-Nafion Membranes for PEMFC Authors: Teixeira, António P. S.; Teixeira, Fátima C.; Sá, Ana I. de; Rangel, C. M. Abstract: The integration of new cleaner, renewable and environment-friendly sources and energy vectors for sustainable energy systems are a key challenge for 21st century society. Fuel cells are among the clean energy conversion technologies with vast applications and scope, introducing hydrogen as a flexible and storable energy vector and presenting a viable alternative to fossil fuels. Proton exchange membrane fuel cells (PEMFCs) are considered promising power sources, but their performance depends crucially on the properties of their proton exchange membranes (PEM). These membranes strongly depend on the presence of conducting water or other electrolyte content, which limits their operation to 80 ºC. In order to advance novel membranes for application in PEMFCs, we have developed a series of bisphosphonic acid derivatives, which are used as dopants. Herein, we present the preparation and characterization of the new Nafion doped membranes, and the evaluation of their proton conductivity at different temperature and relative humidity (RH) conditions. In this work, new Nafion doped membranes were prepared and their proton conductivity were evaluated. The incorporation of BPs dopants on Nafion polymer enhances the proton conductivities of the new membranes, with all membranes showing higher proton conductivities than Nafion. Sat, 31 Aug 2019 23:00:00 GMT http://hdl.handle.net/10174/26474 2019-08-31T23:00:00Z