ESTGV - DEM - Artigo em revista científica, não indexada ao WoS/Scopus
Permanent URI for this collection
Browse
Browsing ESTGV - DEM - Artigo em revista científica, não indexada ao WoS/Scopus by Title
Now showing 1 - 10 of 15
Results Per Page
Sort Options
- Avaliação de impacte ambiental da gestão de resíduos da produção de uma bancada com base na abordagem de ACVPublication . Silva, Luiza; Ferreira Silva, Maria Elisabete; Brás, Isabel; Domingos, Idalina; Ferreira Wessel, Dulcineia; Ferreira, JoséIntroduction: Consumerism has led to an increase in environmental problems, and for this reason, sustainable solutions must be the priority when designing new products or services. Life Cycle Assessment (LCA) is one of the most important analytical tools available for choosing the best decision when it comes to sustainability. Objective: The focus of this study was to apply an LCA to the management of wastes from a kitchen/bathroom countertop production. The waste management scenarios studied were landfill (current practice) and waste recycling. The panel consists of a ceramic layer on a lamellar panel substrate, formed by glassliner and PVC, which is intended to be resistant to water, scratches and impacts. The residues generated from the panel production are glassliner and PVC plastics and ceramics. Methods: The LCA methodology was followed and the EPD 2018 method available in the SimaPro software was chosen to quantify the environmental impacts of waste management. The environmental impact categories studied were eutrophication, global warming, photochemical oxidation, ozone layer depletion, abiotic depletion and acidification. Results: The results showed that the two plastic wastes are the main contributors to acidification, eutrophication and global warming. However, for photochemical oxidation and water scarcity, the ceramic component residue is the main contributor. Comparing the two scenarios, waste recycling reduces the impacts in all environmental impact categories, in comparison with landfill. Conclusion: Recycling the residues from the production of panels brings improvements in environmental impacts in all categories analyzed.
- Ensino Superior e a Realidade Empresarial: em busca do adequado interposicionamentoPublication . Figueiredo, António JoséO grande "divórcio" que tem caracterizado o interrelacionamento entre ensino superior e a realidade do jogo económico tem - salvo honrosas e escassíssimas excepções - resistido tenazmente quer a críticas quer às variadas tentativas dos "conselheiros matrimoniais" mais empenhados. Se, por um lado, a realidade empresarial se queixa do grande desajuste entre a formação com que os alunos saem das nossas escolas de ensino superior e as reais necessidades das empresas e demais organizações, por outro assiste-se à lamentação das escolas em relação à falta de interesse com que empresários e outros responsáveis encaram a sua participação - supostamente activa - nos conselhos consultivos e, de um modo geral, sempre que são chamados a sugerir, colaborar, ou seja, a contribuir para o almejado ajustamento de posicionamentos.
- Evolution of land use environmental impact of eucalyptus globulus in the context of life cycle assessmentPublication . Ferreira, José; Esteves, Bruno; Domingos, IdalinaIntroduction: The eucalyptus globulus forest area in Continental Portugal has shown a systematic increase over the last 50 years. In 20015 it was the species with the highest forest land occupation representing 26.2% of the total Portuguese forest area. Although between 2005 and 2015 the occupation of the soil by eucalyptus globulus had grown about 7.5%, the existing volume increased slightly 0.2%. The wildfires had a strong impact on this with a total burnt area of 1.1 million hectares during this period. Objective: Due to its economic value (national leader in exports of high added value) and social (contributes to the generation of thousands of jobs) this study aims to assess the evolution of the environmental impact of eucalyptus globulus on the land use between 2005 and 2015. Methods: The life cycle assessment methodology is followed and the ILCD 2011 Midpoint+ method available in the SimaPro software was chosen to assess the land use environmental impact. Results: Land use impact category of 1 m3 of eucalyptus globulus trees, standing, in forest, was 21832 Kg C deficit in 2005 and 23430 Kg c deficit in 2015 that means an increased about 7.3% during this period. Conclusion: Transformation to forest road (from natural forest) is the process that most contributes for the land use impact with approximately 78%. Forest occupation is the second most important process representing about 19.5% of the total impact category and forest road occupation represents only 3%.
- Heat induced colour changes of pine (Pinus pinaster) and eucalypt (Eucalyptus globulus) woodPublication . Esteves, BrunoHeat treatment of Pinus pinaster and Eucalyptus globulus wood was made by hot air in an oven during 2 to 24 h at 170-200 ºC and by steam in an autoclave during 2 to 12 h at 190- 210 ºC. The colour parameters L*, a* and b* were determined by the CIELAB method on radial, tangential and transverse sections for untreated and treated wood, and their variation with the treatment (ΔL*, Δa* and Δb*) were calculated in percent. In the untreated woods, for eucalypt wood lightness (L*) varied between 54.1- 63.8% with a* between 7.4-8.5 and b* 15.7-19.9, and for pine wood L* varied between 67.3-76.1%, a* between 6.9 -7.6 and b* 16.3 -24.1. With the heat treatment wood became darker, more for oven treatment (ΔL* about 50% for 4% mass loss), and at the same treatment conditions more for eucalypt wood. In general the contribution of the red colour (a*) and yellow (b*) decreased with the heat treatment. The transverse section darkened less in the two species and for both treatments, with small differences between radial and tangential sections. Lightness decrease was related to chemical changes, with good correlations with glucose (R2= 0.96), hemicelluloses (R2 = 0.92) and lignin (R2 = 0.86). As regards colour, the heat treatments showed an interesting potential to improve the wood quality for solid timber products from pine and eucalypt.
- Improvement of technological quality of eucalypt wood by heat treatment in air at 170-200ºCPublication . Esteves, BrunoEucalypt wood is a low value wood considered a non durable species with low dimensional stability, used almost exclusively for pulp and paper or as firewood. The heat treatment was made in an oven in the presence of oxygen during 2 to 24 h and temperatures of 170-200ºC. Mass loss with treatment, equilibrium moisture content, dimensional stability measured as ASE in radial and tangential directions and at 35%, 65% and 85% relative humidity, MOE, bending strength and wettability were determined. Mass loss increased with treatment time and temperature reaching 9.5% for wood treated at 190ºC for 24h. Equilibrium moisture content decreased more than 50% (at 35% relative humidity) reaching a maximum of 61% reduction. At higher air relative humidity the reduction was smaller, 49% and 38% at the most for 65% and 85% relative humidity. Dimensional stability (ASE) increased with maximum values of 88% and 96% in radial and tangential direction, respectively. The improvement was higher for lower relative humidity. There was a reduction on mechanical resistance with heat treatment especially for bending strength that decreased about 20% for 3% mass loss, reaching 60% for mass losses higher than 10%. MOE decreased with heat treatment the reduction was under 10% until 8% mass loss. The contact angle increased until 5% mass loss, decreasing slightly afterwards. Heat treatment was shown to be a useful method to improve the technological quality of eucalypt wood as regards dimensional stability allowing it to compete with higher cost woods for some applications.
- A Indústria de Preservação em PortugalPublication . Esteves, Bruno MiguelA preservação de madeiras é uma ciência que remonta aos primórdios da civilização e que terá tido origem nas civilizações egípcia e chinesa. No século X a.C. já havia uma preocupação em tratar a madeira dos barcos com extractos de óleo de cedro, com o intuito de os proteger contra a biodegradação. No início do século XIX, devido ao enorme consumo de madeira na construção e reparação de barcos dos impérios coloniais, a falta de espécies duráveis, como cedros e carvalhos, obrigou ao uso de espécies menos resistentes, o que aumentou os problemas da biodegradação. Consequentemente, a preservação de madeiras voltou a ser uma área de estudo muito importante. Em 1832, Kyanizing usou com sucesso cloreto de mercúrio na preservação de madeiras e, em 1833, Theodor Hartig foi o primeiro a registar, através de um microscópio, as hifas de um fungo numa madeira atacada (Zabel e Morrell 1992). O surgimento da era moderna da preservação deve-se ao trabalho de Moll que, em 1836, patenteou o uso do creosote na preservação de madeiras e de Jonh Bethell que, em 1838, desenvolveu um processo de introdução de preservantes na madeira, apelidado de processo de célula-cheia, utilizando um sistema de pressão, método que ainda é amplamente utilizado nos dias de hoje. Os métodos de Rueping e Lowry – processos de célula vazia para uso com preservantes oleossolúveis – surgiram alguns anos depois. A protecção da madeira pode ser uma protecção a curto ou a longo prazo. A aplicação de algumas soluções na superfície da madeira por imersão, pincelagem ou por spray, apenas a protegem durante cinco a seis meses, enquanto a protecção a longo prazo necessita de uma penetração superior na madeira, o que só se consegue por imersão da madeira ou com pressão.
- Influence of steam heating on the properties of pine (Pinus pinaster) and eucalypt (Eucalyptus globulus) woodPublication . Esteves, Bruno; Velez Marques, António; Domingos, Idalina; Pereira, HelenaHeat treatment of Pinus pinaster and Eucalyptus globulus woods, two important species in Portugal, was made in the absence of air by steaming, inside an autoclave, for 2 to 12h at 190 ºC to 210ºC. Mass losses increased with treatment time and temperature reaching 7.3% for pine and 14.5% for eucalypt wood. The wood behaviour with moisture was improved. The equilibrium moisture content decreased by 46% for pine and 61% for eucalypt, the dimensional stability increased (maximum anti-shrinking efficiency in the radial direction of 57% and 90% for pine and eucalypt respectively) and the surface wettability was lowered. In relation to mechanical properties, the modulus of elasticity was little affected (maximum decrease of 5% for pine and 15% for eucalypt) but the bending strength was reduced (by 40% at 8% mass loss for pine and 50% at 9% mass loss for eucalypt wood). The variation of properties was related to treatment intensity and mass loss but significant improvements could already be obtained for a 3-4% mass loss without impairing the mechanical resistance. The response of eucalypt was higher than that of pinewood. Heat treatment of eucalypt wood shows an interesting potential to improve the wood quality for solid timber products.
- A Influência da Prensagem a Quente nas Propriedades dos Painéis de Fibras de Alta Densidade, Aquando do seu Revestimento por PelículasPublication . Domingos, Idalina; Almeida, Paula; Esteves, Bruno; Ferreira, JoséUm conjunto de painéis de fibras de alta densidade, colados com uma resina de melamina/ureia-formaldeído, foi submetido a operações de prensagem a quente, de modo a estudar a influência desta operação nas propriedades do substrato. Usou-se uma prensa de pratos, a uma pressão que permitisse um contacto firme entre os painéis e os pratos da prensa. Foi desenvolvido um plano experimental para três temperaturas diferentes de 95, 180 e 210 º C e dois tempos de prensagem, de 22 e 35 segundos, para cada uma delas. Os painéis foram fabricados com fibras de pinho (Pinus pinaster) a uma densidade média de 930 kg/m3 e espessura média de 6,7 mm De acordo com os resultados obtidos, as operações de pós-fabrico dos painéis de alta densidade resultaram numa ligeira melhoria do módulo de elasticidade, da tensão de rotura à flexão estática e da resistência interna dos painéis usados como substrato. Observou-se também uma ligeira diminuição da humidade de equilíbrio e espessura dos painéis, bem como um aumento da densidade e do inchamento, com o aumento da temperatura e tempo de prensagem.
- Life cycle assessment of computers and electronic devices: A comprehensive review of environmental impactsPublication . Domingos Ferreira, Miguel; Domingos, idalina; Ferreira, José; IJASEATThe objective of this study was to evaluate Life Cycle Assessment studies applied to computers with respect to temporal and geographical distribution, research subjects, impact assessment methods, databases and software utilized, and principal findings. To achieve this, a bibliographical search was conducted using the Web of Science Core Collection database platform, using the keywords "Life cycle assessment" "AND" "computer" for title topic. The search yielded 12 publications selected from 28, for which a descriptive analysis was performed. It was determined that most of the studies (six in total) took place between 2011 and 2020. Geographically, the majority of these studies were conducted in Asia and the USA/Canada, with six studies in each region. The majority of studies (6) have aimed to evaluate the environmental impacts of computers (desktop/all-in-one). Regarding the impact assessment methods employed, there is considerable variation among ReciPe (2), Ecoindicator (2), IPCC (2), and CML (1), although some studies have utilized multiple methods. The primary findings indicate significant environmental benefits from adopting newer, energy-efficient technologies (APCs and LCDs), improving formal e-waste management, and focusing on recycling and sustainable manufacturing. Proper End-of-Life handling and the minimization of informal disposal also yield substantial environmental gains.
- LIFE CYCLE ASSESSMENT OF PIG PRODUCTION: A CASE STUDYPublication . Ferreira, José; Leite dos Santos, Lenise Maria; Domingos Ferreira, Miguel; OLIVEIRA VERONICA; RODRIGUES CARLA; FERREIRA ANTONIO; Domingos, idalina; IRAJPig farming plays a crucial socioeconomic role in the European Union (EU), with Germany, France, and Spain leading pork production. In Portugal, pig farming is vital for regional development and national economy. To ensure future sustainability, it is essential to identify the pig production activities that have the most significant environmental impacts. This study carried out a Life Cycle Assessment (cradle-to-gate) of pig production using a conventional system in central Portugal to identify the phases with the greatest environmental impact. LCA followed the ISO 14040/14044 standards, covering the production cycle, using 1 kg of live pig weight as a functional unit. The analyzed scenario encompasses everything from the production and growth of piglets to the pig fattening phase, including the formulation of specific feed for each stage of development, transport of inputs, use of diesel to generate electricity in the facilities, and management of pig manure. The results highlight feed production and piglet management as the most important steps. The study highlights the importance of sustainable practices in order to mitigate environmental issues such as human carcinogenic toxicity and the ecotoxicity of freshwater and marine water, emphasizing the need for improved strategies in pig farming.