IPT - Techn&Art - Artigos em Revistas Científicas
Permanent URI for this collection
Browse
Browsing IPT - Techn&Art - Artigos em Revistas Científicas by Issue Date
Now showing 1 - 10 of 52
Results Per Page
Sort Options
- Water quality monitoring in the Paul do Boquilobo Biosphere ReservePublication . Baptista, C.; Santos, LuisThe Paul do Boquilobo is an important wetland ecosystem classified by Unesco as a MAB Biosphere reserve also awarded Ramsar site status, representing one of the most important habitats for the resident nesting colony of Cattle Egret (Bulbucus ibis). Yet owing to its location, it suffers from human induced impacts which include industrial and domestic effluent discharges as well as agricultural land use which have negatively impacted water quality. The current study reports the results obtained from the introductory monitoring programme of surface water quality in the Nature Reserve to emphasize the detrimental impact of the anthropogenic activities in the water quality of such an important ecosystem. The study involved physicochemical and biotic variables, microbial parameters and biological indicators. Results after 3 years of monitoring bring to evidence a poor water quality further impaired by seasonal patterns. Statistical analysis of data attributed water quality variation to 3 main parameters – pH, dissolved oxygen and nitrates, indicating heavy contamination loads from both organic and agricultural sources. Seasonality plays a role in water flow and climatic conditions, where sampling sites presented variable water quality data, suggesting a depurative function of the wetland.
- E-waste Management in Portugal: Legislation, Practices and RecommendationsPublication . Marques, C. G.; Silva, VascoThe use of electrical and electronic devices has grown exponentially in the last years thanks to technological advances and its wide dissemination. Consequently, the number of obsolete equipment (electronic waste or e-waste) has also increased significantly, becoming a major problem for society. This paper deals with electronic waste and explains the concept and risks for the particular case of Portugal. Measures to reduce the problem such as legislation, education production R&D and social responsibility are also discussed. And finally, a survey is presented which was carried out in two Portuguese Higher Education institutions with a view to determining students' awareness, attitudes and opinions on this matter.
- Using Mobile Technologies in Education: A New Pedagogical Approach to Promote Reading LiteracyPublication . Marques, C. G.; Manso, António; Ferreira, Ana Paula; Morgado, FelisbelaThe acquisition of reading skills is decisive for the academic achievement of students. However, learning to read is a complex process. With this in mind, several attempts have been made to find new educational approaches to enhance students' reading motivation. Considering the enormous potential of ICT for education and training, we have developed a digital repository of teaching and learning materials and a multiplatform application that runs on mobile devices: Letrinhas. This information system was designed to promote the development of reading and to provide tools for monitoring and assessing reading skills against the curricular targets set by the Ministry of Education. Letrinhas was evaluated by specialists and users and a high level of satisfaction was observed among students and teachers as time and effort spent to consolidate reading is considerably reduced with this application. This evaluation also enabled to identify features that will be available in the future.
- New changes of a journal in transformation,Novas mudanças de uma revista em transformaçãoPublication . Cruz, António João
- Dome and Away: Logan's Run Post-Apocalyptic CityscapesPublication . Sol, HermíniaThe rapid growth of population has been a global concern for quite some time due to its severe environmental, poverty control and social instability implications. A concern that becomes even more acute if one is to accept the United Nations’ Population Division latest predictions that by 2050, more than two-thirds of the world’s population is to live in cities (United Nations 1). Despite not being new, the concept of smart city has, in recent years, acquired privileged status amongst city planners and imagineers all over the world due to the belief that its focus on innovation, technology, ecology and people’s well-being can contribute to a more sustainable urban paradigm (Cowley; Dameri; Lindner). Mostly, smart cities are fast becoming a tangible representation of the futuristic cityscapes which were, till recently, confined to science fiction literature and cinema. Thus, it is no wonder that these tend to be regarded as a sort of dream-come-true project with a strong emphasis on the notion that the products and mechanism generated therein will ultimately “ensure the ‘good life’” (Foley et. al. 84). Whether this premise is a hundred percent valid it remains to be seen as smart-city initiatives are still being put to the test. Yet, the dangerous implications of present-day societies’ blind faith and dependence on technology have been persistently tackled in science fiction texts since the 1950s. A fine example of one such text is Michael Anderson’s film Logan’s Run (1976), a dystopian account of the pleasures and perils of the inhabitants of a computer controlled domed city in a post-apocalyptic future scenario. As defended by several researchers (Bina et al.; Foley et. al.), science fiction’s speculative spectrum regarding architecture and urban planning is particularly relevant as it provides “alternative insights into what challenges lie ahead,” both in terms of “future ‘possibilities’ and ‘warning signals’” (Bina et. al. 167). Consequently, both material and imaginary cityscapes “mingle and resonate together in complex and unpredictable ways” (Graham 395) since they influence each other. Bearing all this in mind, this article will first consider science fiction’s impact in the conception of the city of the future. While doing so, it will also consider how the notion of city of the future often carries utopian overtones, only to see them degenerate into dystopian scenarios. Subsequently, it will examine the different architectural styles present in Logan’s Run and their intended symbolism. Lastly, it will look into some warning signs regarding the environmental and personal privacy challenges that come with living in a smart city.
- Eggshell waste to produce building lime: calcium oxide reactivity, industrial, environmental and economic implicationsPublication . Ferraz, Eduardo; Gamelas, José A. F.; Coroado, João; Monteiro, Carlos; Rocha, FernandoEggshells wastes are produced in huge amounts worldwide. The recycling or valorization of this waste, which otherwise is usually disposed in landfills, represents an opportunity within a circular economy perspective. In the present work, the potential of chicken eggshell waste to produce calcitic lime was explored. After collection from an industry supplier, the waste was thoroughly characterized for its mineralogical, chemical, and thermal properties. The material was calcined at 1000 °C, and the obtained calcium oxide was evaluated for its reactivity in wet slaking tests. Comparison was made with commercial limestone used as reference. It was found that the calcium oxide from eggshell waste belonged to the most reactive class (R5—60 °C within 10 min), the same of the calcium oxide from limestone. However, different times were obtained to reach 60 °C (25 s and 4:37 min:s) and for 80% of the reaction (28 s and 5 min) for calcium oxide from limestone and eggshell waste, respectively. The lower reactivity of calcium oxide from eggshell waste was related to its larger size particles with smoother surfaces and lower specific surface area in comparison to limestone calcium oxide. Industrial, environmental and economic implications concerning the use of this waste to produce lime were also evaluated. The eggshell waste could be all consumed at an industrial scale in Portugal allowing for approximately 2.6% partial substitution of limestone in a lime factory.
- Recycling Waste Seashells to Produce Calcitic Lime: Characterization and Wet Slaking ReactivityPublication . Ferraz, Eduardo; Gamelas, José A. F.; Coroado, João; Monteiro, Carlos; Rocha, FernandoThe present work aimed at valorizing marine bivalve shells. First, clam, mussel, edible cockle, wedge, razor, oyster, dog cockle and scallop shells wastes were thoroughly characterised for their mineralogical, chemical and thermal properties. Then, the materials were calcined at 1000 °C, milled and sieved to lower than 0.250 mm. The obtained calcium oxide was subjected to wet slaking test to evaluate its reactivity in the production of hydrated lime. The reactivity results of the calcined materials showed that, dog cockle (60 °C in 7:54 min:s) and edible cockle (60 °C in 9:20 min:s) can be classified in the most reactive class (R5) in which 60 °C is reached in less than 10 min. The remaining species were classified in the R4 class, reaching 60 °C between 10 and 25 min, with the lowest reactivity being found for oyster shell (60 °C in 19:09 min:s). Interestingly, the hydrated limes from seashells typically presented a white tonality superior that of the lime from commercial limestone used as reference. Overall, seashell wastes can be used in the production of lime, with several benefits, including, the inexistence of environmental impacts related to the exploitation of limestone on quarry, lesser energy spent in the comminution process, or, inexistence of disposal costs related with landfill tariff. These wastes could thus be used as raw materials in other industrial sector.
- Composites of nanofibrillated cellulose with clay minerals: A reviewPublication . Alves, L.; Ferraz, Eduardo; Gamelas, J. A. F.Biopolymers-based composites are, in general, environmentally friendly materials, which can be obtained from renewable sources. Some of them can also present promising properties to be used in food packaging and electronic devices, being thus logical substitutes to petroleum-based polymers, specifically plastics. Cellulose nanofibrils (CNF) obtained by chemical/enzymatic pre-treatments followed by a mechanical treatment appear as a new suitable biomaterial. However, CNF are still quite expensive materials, due to the required chemicals/equipment/energy involved, and additionally, they present some limitations such as high hydrophilicity/high water vapour permeability. The combination of CNF with clay minerals, such as montmorillonite or kaolinite, as widely available geo-resources, represents an excellent way to reduce the amount of CNF used, enabling the production of valuable materials and reducing costs; and, at the same time it is possible to improve the characteristics of the formed materials, such as mechanical, gas barrier and fire retardancy properties, if appropriate conditions of preparation are used. Nevertheless, to obtain hybrid CNF/clay composites with superior properties it is necessary to ensure a good dispersion of the inorganic material in the CNF suspension and a good compatibility among the inorganic and organic components. To fulfil this goal, several strategies can be considered, including physical treatments of the suspensions, CNF and clay surface chemical modifications, and the use of a coupling agent. In this review article, the state-of-the-art on a new emerging generation of composites (films, foams or coatings) based on nanofibrillated cellulose and nanoclay, with focus on strategies for their preparation and most relevant achievements is critically reviewed, bearing in mind their potential application as substitutes for common plastics. A third component has been eventually added to these organic-inorganic hybrids, e.g., chitosan, carboxymethylcellulose, borate or epoxy resin, to enhance specific characteristics of the material. Some general background on the production of different types of CNF and their main properties is previously provided.
- The impact of Portuguese legislative changes in local accommodationPublication . Almeida, Paula; Marques, C. G.; Dionísio, Marta; Silva, Cláudia Pires DaThis study seeks to fill the epistemological gap regarding the impact of legislative and regulatory means of managing local accommodation, has been changed, as it relates to the cultural identity of cities and parts of cities in Portugal. We presume such a cultural identity to be a complex entity which is built in part in negotiation with the tourist, but one that is currently being done on an imbalanced relationship. This study is conducted from a law studies point of view, seeking to draw conclusions from recent touristic trends especially in the cities of Porto and Lisbon. The Governmental Decree nº128/2014, August 29th, with the news brought by Decree nº63/2015 created severe dangers to municipal institutions: the risk of ‘desertification’ of the center by local citizens, rent pressure, social polarization, amongst other risks, which led to the “gentrification phenomenon” that has occurred in other centers such as Barcelona, Venice and Berlin. This growth has been leveraged by the use of digital platforms that promote accommodation, like Airbnb, Homeway and Booking. While these digital platforms relate to a shared economy and the democracy of tourism phenomenon as it allows tourists to find accommodation adjusted to their budgets, the lack of policing also led to some scams and taxes evasion. In order to control the unbridled growth of local accommodation in some areas, the national legislator has imposed in Law nº62/2018, 22 of august, the possibility to municipalities to establish, by regulation, some containment areas, to contain registration of more places as local accommodation. On the course of this study we propose to approach the impact of this solution and evaluate the economic impact of these legal efforts to contain that growth.
- The use of glass particles and its consequences in late 16th century oil painting: A Portuguese case based on the analytical results and the technical treatisesPublication . Melo, Helena P.; Cruz, António João; Valadas, Sara; Cardoso, Ana Margarida; Candeias, AntónioColourless glass particles were identified for the first time in Portuguese paintings in two altarpieces attributed to the painter Francisco João, active between 1558 and 1595. They were found in red glazes with conservation problems. The glass was analysed by SEM-EDX and the binder by μ-FTIR. Portuguese 17th century painting treatises, which record earlier practices, were examined providing additional information. The glass particles had a vegetable silica-soda-lime composition, different in the two altarpieces, and a medium to very high alumina content. Although the provenance of the glass could not be determined, the use of local glass is suggested, as archaeological glass of the same period and similar composition has been found in southern Europe, notably Portugal. Furthermore, the glass from one of the altarpieces closely matches the composition of glass found in a painting by the Spaniard Luis de Morales. As a result, it is possible that the painter deliberately added a local glass to his red lakes, as advised in the two Portuguese painting treatises of this period. The exclusive presence of glass in the uppermost medium-rich glazes suggests that it was mainly used for its transparency and assumed siccative role. Although the siccative properties of glass have not been proved, by lowering the oil concentration in the paint, the addition of glass might have indirectly assisted the drying of the glazes. The glass particles were subject to a severe leaching of the alkali, a degradation that might explain the disruption of the glaze layers in these paintings.