Browsing by Issue Date, starting with "2021"
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- Evaluation of cost-optimal retrofit investment in buildings: the case of Bragança fire station, PortugalPublication . Cova, Sónia; Andrade, Carlos A.R.; Soares, Orlando; Lopes, JorgeOffice buildings built before the entry into force of the first thermal regulation in 1991 constitute a relevant group for analysing the energy performance of the Portuguese building sector. A dynamic energy simulation was used to assess the energy performance of an existing office building located in the town of Bragança, Portugal. Four energy efficiency measures were selected and a financial evaluation through the internal rate of return (IRR) method was undertaken to choose the best retrofit option for improving the building’s energy performance. An investment package consisting of the roof insulation and a new equipment for the domestic hot water system presented an IRR higher than the discount rate used in the analysis, and, thus, a positive financial return. The results of the study also suggest that the EU’s comparative methodology framework is not particularly suitable for assessing building retrofit investment at the private investor’s perspective and further refinement in the cost-effective approach to renovations is needed to help stimulate building’s energy renovation market. Suggestions for further studies conducted for office buildings in the different climate zones in Portugal are also proposed.
- Genetic variability of Araucaria angustifolia Bertol. initial growth: subsidy to the formation of seed orchardsPublication . Gerber, Dionatan; Brun, Eleandro José; Topanotti, Larissa Regina; Ferreira, Josângela de Jesus; Porrua, Douglas; Gorenstein, Maurício Romero; Wagner, AméricoThe species Araucaria angustifolia Bertol. is native from Brazil, and it is now an endangered species due to the anthropic actions for several years. The objective of this study was to evaluate the genetic variability of Araucaria angustifolia based on initial growth qualitative and quantitative variables in a provenance and progeny test. Based on this performance, the genotypes with higher presence of superior characteristics were selected, to subsidize the formation of seed orchards. The matrices from Guarapuava-PR and Palmeira-SC were chosen according to their biometric and morphometric characteristics. Each matrix received a control code card. The matrices trees were assessed according to dendrometric and sanitary characteristics, and the harvested pine cones were evaluated for their weight, volume, and sanity. A total of 14 matrices from Palmeira-SC and 10 matrices from Guarapuava- PR were selected. The pinecones from each selected matrix were evaluated by quantitative characters. The seeds of these pineconeswere separated according to matrix tree, and they were used in the experiment to evaluatethe emergency and initial growth among genotypes.All the statistical analyses were conducted in a computational application about genetics –GENES® and on the software R Studio. It was verified that there is genetic variability among the provenances and progenies for most of the quantitative characters studied for A. angustifolia, and thus, there is also the possibility of obtaining gains through selection among and within the provenances. The selection among and within the provenances suggests that it is possible to reach significant genetic gains, especially for weight and diameter of pine cones, weight, and number of seeds per pinecone, and tree growth.
- Designing a simple volumetric apparatus for measuring gas adsorption equilibria and kinetics of sorption. Application and validation for COPublication . Karimi, Mohsen; Rodrigues, Alírio; Silva, José A.C.The screening of adsorbents (zeolites, MOFs, ACs, etc) requires the measurement of adsorption equilibria and kinetics at the milligram scale. In this regard, a volumetric apparatus (constant volume variable pressure – batch adsorber) has been developed for studying adsorption equilibria and kinetics of sorption. Its validation was accomplished by studying the adsorption equilibria of carbon dioxide (CO2), methane (CH4) and nitrogen (N2) and the kinetics of sorption of CO2 on commercial binder-free 4A zeolite. The data collected has an acceptable agreement with already published values by a gravimetric and breakthrough flow technique. The isotherms were modeled using Sips model from low pressure till 8 bar at 303, 343 and 373 K. The sorption kinetics of CO2 was measured from the uptake rate experiments and fitted with a solid-film linear-driving-force model (LDF). It was observed that the LDF mass transfer coefficients increase with pressure and temperature. Finally, the statistical analysis of the data was performed by Response Surface Methodology (RSM) to determine the interactions among process variables such as temperature and pressure in the respective gas adsorption equilibria data.
- Applications of bioactive compounds extracted from olive industry wastes: a reviewPublication . Margaça, Fernanda M.A.; Santos‐Buelga, Celestino; Ferreira, Isabel C.F.R.; Cabo Verde, Sandra; Barros, LillianThe wastes generated during the olive oil extraction process, even if presenting a negative impact for the environment, contain several bioactive compounds that have considerable health benefits. After suitable extraction and purification, these compounds can be used as food antioxidants or as active ingredients in nutraceutical and cosmetic products due to their interesting technological and pharmaceutical properties. The aim of this review, after presenting general applications of the different types of wastes generated from this industry, is to focus on the olive pomace produced by the two-phase system and to explore the challenging applications of the main individual compounds present in this waste. Hydroxytyrosol, tyrosol, oleuropein, oleuropein aglycone, and verbascoside are the most abundant bioactive compounds present in olive pomace. Besides their antioxidant activity, these compounds also demonstrated other biological properties such as antimicrobial, anticancer, or anti-inflammatory, thus being used in formulations to produce pharmaceutical and cosmetic products or in the fortification of food. Nevertheless, it is mandatory to involve both industries and researchers to create strategies to valorize these byproducts while maintaining environmental sustainability.
- Nutritional value and chemical composition of three types of Petroselinum crispum leavesPublication . Ardohain, Elizandra; Fernandes, Ângela; Polyzos, Nikolaos; Petropoulos, Spyridon Α.; Pinela, José; Moreira, Glaucia; Ferreira, Isabel C.F.R.; Barros, LillianPetroselinum crispum Mill. Nym., commonly known as parsley, is an aromatic herb used to garnish and to give flavour and odour to dishes and salads [1]. The most common parsley types in the Mediterranean region are Petroselinum crispum ssp. neapolitanum (plain-leafed) and Petroselinum crispum ssp. crispum (curly- and bioactive properties, such as the genotype, the irrigation regime, the planting density, the sowing date and the climate conditions. The main objective of this study was to evaluate the crop diversification through the determination of the nutritional value and the chemical composition of leaves from twenty-five plain-leafed, curly-leafed and turnip-rooted parsley (Petroselinum crispum ssp. tuberosum) cultivars, cultivated in central Greece. The proximate composition was evaluated by AOAC official procedures, free sugars and tocopherols were determined using liquid chromatography coupled to a refraction index (HPLC-RI) and fluorescence (HPLC-FL) detectors, respectively. Fatty acids were determined by gas chromatography coupled to a flame ionization detector (GC-FID) and organic acids by ultra-fast liquid chromatography coupled to a diode detector (UPLC-DAD) [1]. The plain and curly-leafed type contains higher amount of fat and energy than the turnip-rooted one, protein content was higher in the curly-leafed and turnip-rooted type and no significant differences were observed between the three types in terms of the carbohydrates content. The total sugars content did not differ significantly among the tested -- linolenic and linoleic acid followed by palmitic acid, while only linoleic acid content differed among the cultivar types. The curly-leafed type contains the highest amount of malic, citric and total organic acids, whereas the highest oxalic acid content was recorded in both curly-leafed and turnip-rooted type. The results of our study showed a great variability in the nutritional value parameters and the chemical composition of twenty-five parsley cultivars from three distinct types, which indicates the great potential of the valorization of the existing genotypes to increase the agrobiodiversity and introduce the turnip-rooted type in the Mediterranean region.
- Polydimethylsiloxane composites characterization and its applications: a reviewPublication . Ariati, Ronaldo; Sales, Flaminio; Souza, Andrews Victor Almeida; Lima, Rui A.; Ribeiro, J.E.Polydimethylsiloxane (PDMS) is one of the most promising elastomers due its remarkable pro-prieties such as good thermal stability, biocompatibility corrosion resistance, flexibility, low cost, ease of use, chemically inertia, hyperplastic characteristics, and gas permeability. Thus, it can be used in areas like microfluidic systems, biomedical devices, electronic components, membranes for filtering and pervaporation, sensors and coatings. Although pure PDMS has low mechanical properties, such as low modulus of elasticity and strength, it can be improved by mixing the PDMS with other polymers and by adding particles or reinforcements. Fiber-reinforced PDMS has proved to be a good alternative to manufacture flexible displays, batteries, wearable devices, tac-tile sensors, and energy harvesting systems. PDMS and particulates are often used in the sepa-ration of liquids from wastewater by means of porosity followed by hydrophobicity. Waxes as beeswax and paraffin have proved to be materials capable of improving properties such as hy-drophobic, corrosion resistance, thermal and optical properties of PDMS. Finally, blended with polymers such as poly (vinyl chloride-co-vinyl acetate), PDMS became a highly efficient alterna-tive for separation membrane applications. However, to the best of our knowledge there are few works dedicated to the review and comparison of different PDMS composites. Hence, this review will be focused in PDMS composites, their respective applications, and properties. Generally, it will be discussed the combination of elastomer with fibers, particles, waxes, polymers, and others; aiming to be a review able to demonstrate the wide applications of this material and how tailored characteristics can be reached for custom applications.
- Composite material of PDMS with interchangeable transmittance: study of optical, mechanical properties and wettabilityPublication . Sales, Flaminio; Souza, Andrews; Ariati, Ronaldo; Noronha, Verônica Teixeira; Giovanetti, Elder Gulick; Lima, Rui A.; Ribeiro, J.E.Polydimethylsiloxane (PDMS) is a polymer that has attracted the attention of researchers due to its unique properties such as transparency, biocompatibility, high flexibility, and physical and chemical stability. In addition, PDMS modification and combination with other materials can expand its range of applications. For instance, the ability to perform superhydrophobic coating allows for the manufacture of lenses. However, many of these processes are complex and expensive. One of the most promising modifications, which consists of the development of an interchangeable coating, capable of changing its optical characteristics according to some stimuli, has been underexplored. Thus, we report an experimental study of the mechanical and optical properties and wettability of pure PDMS and of two PDMS composites with the addition of 1% paraffin or beeswax using a gravity casting process. The composites’ tensile strength and hardness were lower when compared with pure PDMS. However, the contact angle was increased, reaching the highest values when using the paraffin additive. Additionally, these composites have shown interesting results for the spectrophotometry tests, i.e., the material changed its optical characteristics when heated, going from opaque at room temperature to transparent, with transmittance around 75%, at 70 °C. As a result, these materials have great potential for use in smart devices, such as sensors, due to its ability to change its transparency at high temperatures.
- Characterization and primary treatment of the effluent of olive pomace oil extractor industryPublication . Mazur, Andressa; Martins, Ramiro; Pietrobelli, Juliana Martins TeixeiraThe olive pomace oil is the principal by-product in the olive oil sector. Nonetheless the production uses olive bagasse after the primary extraction, it also produces byproducts and effluents that need strategic approach to possibility reuse and a treatment. This study aimed for the characterization of the effluent from an olive pomace oil extractor industry and investigate the application of physicochemical pre-treatments to future water reuse. The physicochemical characterization shows high amounts of BOD and COD for the effluent freshly produced (E1) and effluent collected from storage tanks (E2) in the industrial plant. Other parameters were evaluated: Phosphorus, Organic nitrogen and Ammonia, FOG, Phenolic compounds, Alkalinity, TS, TDS and TSS, and Biodegradability (Zahn-Wellens Test). E2 shows the storage tanks were able to reduce 55% of TS and TDS, 77.5% of COD and 69% of BOD when compared with E1. Comparing with the Portuguese legislation, these effluents cannot be discharge to waterbodies and need treatments, such as coagulation and flocculation as tested in this work. Aluminium Sulphate show to work at best as a coagulant in the minimum concentration 10 g/L and pH 5, RIFLOC F45 (4 mg/L) was used as flocculant. After the treatment, it was observed a remotion of 95.6% of turbidity, 76,4% of COD,76,7% of TSS, and 85.4% of PhC when compared with E2. A sampling campaign was carried out on the Tua river to assess its water quality, and samples were taken at four different points to assess the impact of the effluent discharge, with none of the evaluated parameters presenting values higher than those recommended by the Law-Decree nº236/98 from the Portuguese Legislation.
- Brief review on electrocardiogram analysis and classification techniques with machine learning approachesPublication . Borghi, Pedro HenriqueElectrocardiogram captures the electrical activity of the heart. The signal obtained can be used for various purposes such as emotion recognition, heart rate measuring and the main one, cardiac disease diagnosis. But ECG analysis and classification require experienced specialists once it presents high variability and suffers interferences from noises and artefacts. With the increase of data amount on long term records, it might lead to long term dependencies and the process become exhaustive and error prone. Automated systems associated with signal processing techniques aim to help on these tasks by improving the quality of data, extracting meaningful features, selecting the most suitable and training machine learning models to capture and generalize its behaviour. This review brings a brief stage sense of how data flows into these approaches and somewhat techniques are most used. It ends by presenting some of the countless applications that can be found in the research community.
- Fixed bed adsorption of CO2, CH4, and N2 and their mixtures in potassium-exchanged binder-free beads of Y zeolitePublication . Aly, Ezzeldin; Zafanelli, Lucas F.A.S.; Henrique, Adriano; Pires, Marcella Golini; Rodrigues, Alírio; Gleichmann, Kristin; Silva, José A.C.; Golini Pires, MarcellaThe adsorption of carbon dioxide (CO2), methane (CH4), and nitrogen (N2) has been studied on potassium-exchanged (95%) binder-free beads of Y zeolite through single, binary, and ternary fixed bed breakthrough experiments, covering the temperature range between 313 and 423 K and a pressure of up to 350 kPa. At 313 K and 350 kPa, the single-component data obtained showed that the amounts adsorbed of CO2, CH4, and N2 are around 6.42, 1.45, and 0.671 mol kg-1, respectively. The binary experiments CO2/N2 carried out under typical post-combustion conditions show a selectivity of CO2 over N2 around 104. The ternary experiments resulted in the selectivities of CO2 over CH4 and N2 around 19 and 45, respectively. The adsorption equilibrium data have been modeled by the dual-site Langmuir model, and the breakthrough experiments were numerically simulated with a suitable dynamic fixed bed adsorption model. The model predicts with good accuracy the systematic behavior of all breakthrough experiments. The results shown in the present work prove that the potassium-exchanged binder-free beads of Y zeolite enhance the amount adsorbed of CO2 at low partial pressure over other alkali metal-exchanged faujasites and efficiently separate it from binary (CO2/N2) and ternary (CO2/CH4/N2) mixtures by fixed bed adsorption.