A carregar...
29 resultados
Resultados da pesquisa
A mostrar 1 - 10 de 29
- Promoting water efficiency in a student residence as a contribution to sustainability: hydroSAAP innovation projectPublication . Silva, Flora; Barros, João; Afonso, Maria João A.P.S.; Oliveira, Gustavo Gabriel Lima de; Fachada, Ivone; Geraldes, Ana MariaIn addition to the constraints on water availability caused by climatic factors, many urban areas face demographic and pollution phenomena that can affect the efficient supply of water to the population. Therefore, it is increasingly important to implement water efficiency measures, such as reducing consumption by installing water-efficient devices (e.g., taps, showers, and flushing cisterns), without neglecting behavioral aspects, and using alternative sources for non-potable uses. Thus, the “HydroSAAP” innovation project was designed and launched in May 2023 to improve the management of water consumption in a student residence of a Higher Education Institution in the northeast of Portugal, while promoting technical and scientific knowledge about rainwater harvesting systems, still little explored in Portugal. The project phases are: (1) installation of a rainwater harvesting system for non-potable uses, such as floor washing and irrigation of green areas, and water-efficient devices; (2) estimation of water consumption per use after installation of the system and devices (by carrying out a survey to the residents and employees), and promotion of technical and scientific knowledge about the system (e.g., evaluation of the quality of the collected rainwater considering the type of roof, local climatic conditions, and storage time in the reservoir) and (3) knowledge transfer to the academic community and other stakeholders: (i) disseminate the system and devices installed and the knowledge obtained in phase 2; (ii) raise awareness of the importance of the project in water management and (iii) organize seminars, lectures and school visits to the building, as well as activities in collaboration with civil society institutions such as the Ciência Viva Centre. The results of this project include the completion of phase 1 in July, with the installation of the system, seven showers and a kitchen tap with a class A water efficiency rating and certified by a national organization. Phases 2 and 3 are underway. In phase 2, the quality of the rainwater collected by the system has been analyzed since September. The survey about “Water consumption habits in the student residence” was approved by the Institution's Ethics Committee at the end of November and will be addressed to the residents and employees. In phase 3, the project has already been combined with educational practice, having been disseminated to the academic community through the organization of the seminar “Sustainability in the use of water: Importance, techniques and challenges”, which took place in November at the Institution, with the participation of experts in the field of sustainable water use and reuse, mostly involving students from Civil and Environmental Engineering and local stakeholders. It is important to note that the involvement of the students and stakeholders in this project will help to disseminate the obtained knowledge and could be the starting point for further promoting education for sustainable water use. It is also intended to replicate this project for other types of buildings and other non-potable uses, and to extend it to the industrial and agricultural sectors. As the activities of this project will be extended beyond the funding period (planned until December 2023), it is hoped that it will make an overall contribution to promoting sustainable water management in urban areas.
- Towards Sustainable Water Use in Two University Student Residences: A Case StudyPublication . Geraldes, Ana Maria; Ohara, Gabriel; Afonso, Maria João A.P.S.; Albuquerque, António; Silva, FloraThis research is focused on the water usage patterns in two student residences—one for male students (Residence I) and the other for female students (Residence II). Surveys and measurements of flushing cisterns, taps, and shower flows were conducted to understand water use behaviors. Scenario 1 proposed replacing washbasin and kitchen taps and installing flow reducers in showers, while Scenario 2 combined Scenario 1 with a rainwater harvesting system for recharging flush cisterns. Showers were found to be the most water-consuming devices, accounting for 46% and 61.41% of water consumption in Residences I and II, respectively, followed by kitchen taps (31.51% in Residence I and 11.52% in Residence II). The flushing cistern consumption was 7.02% in Residence I and 13.22% in Residence II. The implementation of Scenario 1 anticipates a 13% reduction in total water consumption in Residence I and a 10% reduction in Residence II. The reduction in hot water consumption would result in a decrease in annual electricity consumption by 27.8% and 23.06% in Residence I and II, respectively. With the implementation of Scenario 2, the total potential water savings for Residence I could increase to 19.98%, and for Residence II, it could rise to 23.17%. The proposed measures aim to enhance water sustainability in these buildings and can be replicated elsewhere.
- Improving water efficiency in a municipal indoor swimming-pool complex: a case studyPublication . Silva, Flora; Geraldes, Ana Maria; Zavattieri, Carmem; Afonso, Maria João A.P.S.; Freire, Flávio; Albuquerque, AntónioThis study aimed to determine the water demand of a municipal swimming pool complex to propose water use efficiency measures. Concomitantly, the possibility of recycling and reusing the water from filter backwashing was evaluated. The pools consumed 25.6% of water, the filter backwashing 24.5%, and the showers 34.7%. Despite the current impossibility of reducing water consumption in pools and filter backwashing, it is feasible to promote more efficient use of water through reducing water consumption by adopting simple water-saving initiatives for showers, taps, and flushing cisterns. These were organized into three distinct scenarios: (a) flushing cistern volume adjustment and the replacement of washbasin and kitchen taps; (b) flushing cistern volume adjustment and shower replacement and (c) flushing cistern volume adjustment, shower, washbasin, and kitchen taps replacement. Under scenarios 1, 2, and 3, the water consumption reduction was 8.0, 13.2, and 20.4%, respectively. The initial investment for scenario 1 was €2290.5, €859.0 for scenario 2 and €3149.5 for scenario 3; the annual water bill reduction was €7115.4, €11,518.1, and €17,655.9, respectively. Therefore, the turnover of the investment was four (scenario 1), one (scenario 2), and three months (scenario 3). The filter washings attained the required standard for irrigation after being subjected to 15 h of sedimentation.
- Effect of stirring and ultrasound-assisted extraction conditions in flavonoids, tannins, antioxidant, antimicrobial activities of the outer skin of chestnuts (Castanea sativa Miller)Publication . Afonso, Maria João A.P.S.; Dias, Rolando; Gomes, Catarina; Pereira, Ermelinda; Guerra, Nelson P.; Ramalhosa, ElsaThis study aimed to evaluate the presence of bioactive antioxidant molecules in chestnut outer shells. For this proposal, several extraction procedures were used, specifically different solvents (water, ethanol:water (80:20) and acetone:water (80:20)) combined with two extraction methods (stirring and ultrasounds (US)) and times of extraction. Several chemical assays were applied to evaluate the flavonoids, hydrolysable and condensed tannins contents, and the antioxidant activity by total reducing capacity, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, and reducing power. Some individual compounds were identified by HPLC-UV detection. Furthermore, the antimicrobial activity of the obtained extracts was screened using different microorganisms, namely Gram-positive bacteria (Staphylococcus aureus, Bacillus subtilis, Bacillus cereus, Enterococcus faecalis) and Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa, Enterobacter aerogenes, Proteus mirabilis, Klebsiella pneumoniae), as well as fungi (Candida albicans). The mixture acetone:water (80:20) was the best solvent to extract condensed tannins and flavonoids. It was with this mixture that the best total reducing capacity, (DPPH) radical scavenging activity and reducing power were determined. The highest extraction yield was also obtained with this mixture. Only for the hydrolysable tannins, the most suitable extraction solution was ethanol:water (80:20). The presence of gallic and tannic acids was detected by HPLC-UV. Concerning the extraction methods, only the extracts obtained by the US exhibited antimicrobial activity. The ethanolic extract showed antimicrobial activity against the Gram-positive bacteria (Staphylococcus aureus, Bacillus subtilis, Bacillus cereus, Enterococcus faecalis) and the extracts with acetone:water (80:20) and water showed antimicrobial activity against Proteus mirabilis. The results of this study demonstrated that the chestnut outer shell is a promising source of bioactive compounds.
- Effect of extraction conditions on flavonoids, tannins, antioxidant and antimicrobial activities of chestnut outer shells (Castanea sativa Miller)Publication . Afonso, Maria João A.P.S.; Dias, Rolando; Gomes, Catarina; Pereira, Ermelinda; Pérez Guerra, Nelson; Ramalhosa, ElsaDuring the chestnut processing, are generated high amounts of by-products such as chestnut outer shells. They are a promising source of bioactive compounds. This study aimed to evaluate the presence of bioactive compounds in chestnut outer shells (Castanea sativa Mill.), to valorize this by-product. Material and methods. Several extraction procedures were used, specifically different solvents (water, ethanol:water (80:20) and acetone:water (80:20)), combined with two extraction methods (stirring (ST) and ultrasounds (US)) and extraction times. Flavonoids, hydrolizable and condensed tannins, antioxidant activity, antimicrobial activity were determined in the extracts. HPLC-PDA analysis was made to identify some phenolic compounds. Results. The acetone:water (80:20) mixture was the best solvent to extract flavonoids and condensed tannins. With this solvent, the highest total reducing capacity, DPPH radical scavenging activity, and reducing power were also obtained. On the contrary, the most suitable extraction solution for hydrolysable tannins was ethanol:water (80:20). Gallic, (+)-catechin, and tannic acids were detected by HPLC-PDA. Only the extracts obtained by the US exhibited antimicrobial activity. Conclusion. It was stated that chestnut outer shells have high amounts of bioactive compounds. In the extractions, the solvent plays a higher role than the method applied.
- Polymer laboratory: an educational approachPublication . Barreiro, M.F.; Plasencia, Paula; Afonso, Maria João A.P.S.; Silva, Adília T.; Ferreira, OlgaPolymers are part of our everyday lives. They assume different forms such as plastics, fibres, foams and elastomers. Its prevalence in modern society and impact on several industrial sectors is well recognized and motivates the development of different educational tools to support the demonstration of polymer chemistry principles, very often hard to rationalize. This work aims to present the work developed within the science communication project CV/PVI/1386-Laboratório de Polímeros (Polymer Laboratory), financed by Ciência Viva (2006-2008). Three modules have been developed concerning the following main thematics: (1) Polymer concepts; (2) Polymer synthesis and (3) Polymer properties. They were designed to be devoted to a wide target public including students from primary and secondary schools to undergraduate levels, and general society. Several demonstration/experimental kits were developed. Concepts such as polymer architecture (linear, branched and crosslinked) and polymer synthesis procedures (step versus chain growth polymerization) can be demonstrated by using the “Kit-models”. Here the student is able to create several models representative of the concepts to be illustrated. Synthesis examples include the preparation of linear polymers to networks. In the first case Nylon 6-10 synthesis is proposed and, in the second one, polyurethane foam (chemical crosslinking) and a PVA polymer slime (ionic crosslinking) can be experienced. Among polymer properties, several demonstrations can be mentioned: (1) Dissolution versus swelling, (2) Swelling versus crosslinking degree, (3) Hydrophobic versus hydrophilic polymers and (4) Polymer identification. Following the experience acquired with the former project, the work has continued, expanding the developed concepts. The demonstration/experimental kits were improved, an identification logo was created, and the production of a book of protocols and a web page are currently in course.
- Evaluation of the kefir potential to produce a fermented product from chestnut purée: a preliminary studyPublication . Afonso, Maria João A.P.S.; Guerra, Nelson P.; Río, Pablo G.; Martins, Fátima; Baptista, Paula; Pereira, Ermelinda; Ramalhosa, ElsaThe concept of functional food as a source of energy and nutrients, promoting healthy benefit and reducing the disease risk
- Phenolic compounds content, antioxidant and antimicrobial activities of juniper (Juniperus communis L.)Publication . Bacém, Isabel; Afonso, Maria João A.P.S.; Amaral, Joana S.Juniper (Juniper communis L.) berries are widely used in different products such as perfumes, pharmaceuticals and to aromatize alcoholic beverages. In particular, they are employed with other botanical ingredients in the production of commonly consumed juniper-based spirits, such as gin [1]. Juniper berries are also frequently used in the European gastronomy to season and flavour foods, being considered the only spice obtained from Cupressaceae plants and one of the few examples of spices produced in cold or temperate regions [2]. In the northeast region of Portugal, the berries are traditionally used in game meat dishes. Besides being used in drinks and for culinary purposes, J. communis berries are also used in folk medicine for their diuretic, antiseptic, stomachic, and carminative properties [3], being inscribed in different Pharmacopoeias. In this work, the total content of phenolic compounds and of flavonoids, reducing power and antioxidant activity (in vitro measurement of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity) of the methanolic extracts of juniper (Juniperus communis L.) berries and leaves were evaluated using spectrophotometric techniques. Two samples of berries were acquired in a local supermarket and in a specialized store, respectively and one sample of berries and leaves were collected in the wild in Trásos- Montes region. Additionally, the antimicrobial activity of a sample of essential oil obtained by hydrodistillation was determined by the macrodillution broth assay against several Gram-positive and Gram-negative bacteria and Candida albicans. Total phenolics content, determined by the Folin-Ciocalteu methodology and expressed as mg gallic acid equivalents per gram of sample (GAE/g), ranged from 11.13±1.33 to 16.16±0.64 mg GAE/g for the berries samples, being significantly higher for the leaves sample (141.12±9.56 mg GAE/g). As expected, based on the phytochemicals content determined for the berries and leaves, the leaves showed a higher reducing power (EC50=0.17±0.00 mg/mL) and antioxidant activity, measured as the ability to decrease to 50% the DPPH absorbance (EC50= 0.10±0.01 mg/mL) compared to the berries (reducing power ranging from 2.40±0.04 to 3.48±0.26 mg/mL and antioxidant activity ranging from 1.74±0.04 to 3.84±0.39 mg/mL). The essential oil was able to inhibit the growth of C. albicans and different bacteria (Bacillus cereus, Bacillus subtillis, Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae and Enterococcus faecalis) to different extents, while showing no activity against Pseudomonas aeruginosa and Proteus mirabilis.
- Efeito da temperatura no comportamento reológico de méis colhidos na região nordeste de PortugalPublication . Magalhães, Marta; Castro, Marina; Afonso, Maria João A.P.S.; Ramalhosa, ElsaO mel é um produto biológico produzido pelas abelhas a partir do néctar recolhido das flores e processado pelas enzimas digestivas destes insetos. A sua produção é de elevada importância económica, principalmente para as comunidades rurais da zona de Trás-os-Montes. O mel tem inúmeras aplicações, além de apresentar propriedades antimicrobianas e antissépticas. A viscosidade é considerada uma das mais importantes propriedades do mel. Esta propriedade tem particular interesse para os apicultores porque afeta a vida útil do produto, o processamento e o acondicionamento do mel. No que respeita à consistência, o mel pode apresentar-se fluido, espesso ou, parcial ou totalmente cristalizado. Como o mercado, em grande parte, favorece a venda do mel líquido, alguns tipos de tratamento são necessários para manter o mel nesse estado, tais como, a filtração e o aquecimento. O aquecimento é aplicado por inúmeras razões, como por exemplo, para facilitar a sua manipulação e acondicionamento, retardar o fenómeno de granulação e destruir microrganismos que possam estar presentes e que possam alterar negativamente a qualidade do mel. No presente trabalho estudou-se as propriedades reológicas de três méis colhidos no nordeste de Portugal. Dois méis monoflorais – urze e rosmaninho – provenientes do Parque Natural de Montesinho, e um mel polifloral do Sítio de Morais. Como o aquecimento é aplicado para manter o mel em estado líquido e como também é utilizado na preparação de vários pratos culinários, o comportamento reológico desses méis foi analisado às temperaturas de 30, 50, 70 e 95 ºC. Para tal, foi utilizado um viscosímetro de cilindros concêntricos equipado com um controlador de temperatura. Todos os méis estudados apresentaram um fluxo independente do tempo e a sua maioria comportou-se como um Fluido Newtoniano, ou seja, com viscosidade constante. Apenas o mel de urze à temperatura de 50 °C e o mel de rosmaninho à temperatura de 95 °C demonstraram ter comportamento de um Fluido Pseudoplástico. A dependência da viscosidade com a temperatura foi descrita pela equação de Arrhenius, tendo a energia de activação (Ea) variado entre 72,6 e 81,3 KJ/mol. De entre os méis analisados, o mel de rosmaninho foi aquele que mostrou ser mais sensível à temperatura, apresentando o valor mais elevado de Ea (81,3 kJ/mol).
- Promoting water efficiency in a municipal market building: a case studyPublication . Geraldes, Ana Maria; Pinto, Matheus Fagundes Garcia Duarte Alves; Afonso, Maria João A.P.S.; Albuquerque, António; Calheiros, Cristina; Silva, FloraThis study aimed to determine the water demand of a Municipal Market building to propose water use efficiency measures. The flushing cisterns have the highest water consumption (63.15%), followed by washbasins, restaurant and coffee shop taps, and hairdresser's showerhead (31.64%). Therefore, the implementation of two main categories of solutions: reducing water consumption through the adoption of efficient devices and installing a rainwater harvesting system (RWHS) when drinking water quality is not required, was evaluated. These solutions were organized in four distinct scenarios: (1) Flushing cistern replacement by dual-flush ones; (2) washbasins, restaurant, coffee shop taps, and hairdresser showerhead replacement; (3) scenario 1 combined to a RWHS for recharging the replaced flushing cisterns and (4) combining scenarios 3 and 4. Under scenarios 1, 2, 3, and 4, the expected water consumption reduction was 28.36%, 17.06%, 57.36%, and 74.41%, respectively. As a result, the annual water bill reduction was euro3835.81 (scenario 1), euro2307.07 (scenario 2), euro7757.65 (scenario 3), and euro10,064.73 (scenario 4). Furthermore, to ensure the harvested rainwater attains the required standard for recharge flushing cisterns, it is advisable to dispose of the first-flush rainwater collected after a long dry period.
- «
- 1 (current)
- 2
- 3
- »