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- Solution-Processable Donor-Acceptor-Donor Oligomers with Cross-Linkable FunctionalityPublication . Brotas, Graça; Costa, Cristiana; Dias, Sandra I. G.; Costa, Pedro M. M.; Paolo, Roberto E. Di; Martins, João; Farinhas, Joana; Alcácer, Luís; Jorge Morgado; Matos, Manuel; Charas, AnaElectron-acceptor units, combined with bithiophene substituted with flexible chains end-functionalized with cross-linkable moieties, provide soluble donor-acceptor-donor (DAD) it-conjugated oligomer-type molecules with cross-linking ability and broad absorption in the visible spectrum. A study on the cross-linking conditions of the new oligomers to yield insoluble polymer networks is presented, including conditions for obtaining polymer films over poly(3,4-ethylenedioxythiophene):polystyrene sulfonate-covered substrates. The combination of the DAD molecular design and cross-linking functionality opens prospects for applications in solution-processed small-molecule solar cells with morphologically-stable organic layers.
- Road tunnel, roadside, and urban background measurements of aliphatic compounds in size-segregated particulate matterPublication . Oliveira, Cesar; Martins, Natercia; Mirante, Fátima; Caseiro, Alexandre; Pio, Casimiro; Matos, Manuel; Silva, Hugo; Oliveira, Cristina; Camões, FilomenaParticulate matter samples were collected in a road tunnel in Lisbon (PM0.5, PM0.5-1, PM1-2.5, and PM2.5-10) and at two urban locations representing roadside and background stations (PM2.5 and PM2.5-10). Samples were analysed for organic and elemental carbon (OC and EC), n-alkanes, n-alkenes, hopanes, some isoprenoid compounds, and steranes. Particulate matter concentrations in the tunnel were 17-31 times higher than at roadside in the vicinity, evidencing an aerosol origin almost exclusively in fresh vehicle emissions. PM0.5 in the tunnel comprised more than 60% and 80% of the total OC and EC mass in PM10, respectively. Concentrations of the different aliphatic groups of compounds in the tunnel were up to 89 times higher than at roadside and 143 times higher than at urban background. Based on the application of hopane-to-OC or hopanes-to-EC ratios obtained in the tunnel, it was found that vehicle emissions are the dominant contributor to carbonaceous particles in the city but do not represent the only source of these triterpenic compounds. Contrary to what has been observed in other studies, the Sigma hopane-to-EC ratios were higher in summer than in winter, suggesting that other factors (e.g. biomass burning, dust resuspension, and different fuels/engine technologies) prevail in relation to the photochemical decay of triterpenoid hydrocarbons from vehicle exhaust
- O projeto MySafeWater no ISELPublication . Barreiros, Ana Maria; Silva, Hugo; Matos, Manuel; Gonçalves Cavaco Mendes, Mário José; Monge, Nuno; Sousa, Ana Catarina; Costa, AlexandraO projeto MySafeWater pretendeu promover os objetivos nacionais e europeus, em matéria de Ambiente, no que se refere essencialmente à promoção do “consumo da água da torneira como forma ambientalmente sustentável de consumo, prevenindo a produção de resíduos e diminuindo a pegada ecológica”, através da informação e da conscientização do papel dos cidadãos na promoção do desenvolvimento sustentável em aspetos como a qualidade da água para consumo humano, abrangendo a participação ativa do público e pela sensibilização ambiental e a participação passiva do público.
- OC/EC ratio observations in Europe: Re-thinking the approach for apportionment between primary and secondary organic carbonPublication . Casimiro Pio; Cerqueira, Mario; Harrison, Roy M.; Nunes, Teresa; Mirante, Fátima; Alves, Célia; Oliveira, Cesar; Sanchez de la Campa, Ana; Artinano, Begona; Matos, ManuelThis study explores a large set of OC and EC measurements in PM(10) and PM(2.5) aerosol samples, undertaken with a long term constant analytical methodology, to evaluate the capability of the OC/EC minimum ratio to represent the ratio between the OC and EC aerosol components resulting from fossil fuel combustion (OC(ff)/EC(ff)). The data set covers a wide geographical area in Europe, but with a particular focus upon Portugal, Spain and the United Kingdom, and includes a great variety of sites: urban (background, kerbside and tunnel), industrial, rural and remote. The highest minimum ratios were found in samples from remote and rural sites. Urban background sites have shown spatially and temporally consistent minimum ratios, of around 1.0 for PM(10) and 0.7 for PM(2.5).The consistency of results has suggested that the method could be used as a tool to derive the ratio between OC and EC from fossil fuel combustion and consequently to differentiate OC from primary and secondary sources. To explore this capability, OC and EC measurements were performed in a busy roadway tunnel in central Lisbon. The OC/EC ratio, which reflected the composition of vehicle combustion emissions, was in the range of 03-0.4. Ratios of OC/EC in roadside increment air (roadside minus urban background) in Birmingham, UK also lie within the range 03-0.4. Additional measurements were performed under heavy traffic conditions at two double kerbside sites located in the centre of Lisbon and Madrid. The OC/EC minimum ratios observed at both sites were found to be between those of the tunnel and those of urban background air, suggesting that minimum values commonly obtained for this parameter in open urban atmospheres over-predict the direct emissions of OC(ff) from road transport. Possible reasons for this discrepancy are explored. (C) 2011 Elsevier Ltd. All rights reserved.
- The solid solutions (Per)(2)[PtxAu(1-x)(mnt)(2)]; alloying para-and diamagnetic anions in two-chain compoundsPublication . Matos, Manuel; Bonfait, Gregoire; Santos, Isabel C.; Afonso, Monica L.; Henriques, Rui T.; Almeida, ManuelThe alpha-(Per)(2)[M(mnt)(2)] compounds with M = Pt and Au are isostructural two-chain solids that in addition to partially oxidized conducting perylene chains also contain anionic chains that can be either paramagnetic in the case of M = Pt or diamagnetic for M = Au. The electrical transport and magnetic properties of the solid solutions (Per)(2)[Pt-x-Au(1-x)(mnt)(2)] were investigated. The incorporation of paramagnetic [Pt(mnt)(2)] impurities in the diamagnetic chains, and the effect of breaking the paramagnetic chains with diamagnetic centers for the low and high Pt range of concentrations were respectively probed. In the low Pt concentration range, there is a fast decrease of the metal-to-insulator transition from 12.4 K in the pure Au compound to 9.7 K for x = 0.1 comparable to the 8.1 K in the pure Pt compound. In the range x = 0.5-0.95, only beta-phase crystals could be obtained. The spin-Peierls transition of the pure Pt compound, simultaneous with metal-to-insulator (Peierls) transition is still present for 2% of diamagnetic impurities (x = 0.98) with transition temperature barely affected. Single crystal X-ray diffraction data obtained a high-quality structural refinement of the alpha- phase of the Au and Pt compounds. The beta-phase structure was found to be composed of ordered layers with segregated donors and anion stacks, which alternate with disordered layers. The semiconducting properties of the beta-phase are due to the disorder localization effects.
- Heavy metals contamination of urban soils—a decade study in the city of Lisbon, PortugalPublication . Silva, Hugo; Silva, Nelson A. F.; Oliveira, Cristina; Matos, ManuelThere is an intense and continuous growth of the world population living in cities. This increase in population means an increase in car traffic, an increase in new constructions and an increase in the production of waste that translates into an intensive use of land, particularly in terms of soil contaminants. Among other environmental contaminants, toxic metals, such as lead (Pb), cadmium (Cd), nickel (Ni) and chromium (Cr) represent a public health problem. In this study the content of toxic metals in Lisbon’s (Portugal) soils was determined. The study was conducted over approximately a decade in six city locations, with a total of about 700 samples. Each site has different urban characteristics: traffic zone, residential area, urban park and mixed areas. The study allowed to verify the heterogeneity of metal content values in the city soils and their dependence on local traffic. Metal contents were determined by graphite furnace atomic absorption spectroscopy (GFAAS). For each site the geo-accumulation index, pollution factor, degree of contamination, pollution load índex and ecological risk factor were calculated. The mean concentrations of Cd, Cr, Ni and Pb in soils were 0.463, 44.0, 46.6 and 5.73 mg/kg of dry soil, respectively. In the last year of the study the values were 0.417, 51.5, 62.4 and 8.49 mg/kg of dry soil, respectively. Cd and Ni exceeded the typical content values of these metals in the earth’s crust, indicating their anthropogenic origin. The correlation analysis revealed a significant correlation between Cr and Ni, Cd and Ni and Cd and Pb contents in the city soils. Regarding the results obtained in this long monitoring campaign, Lisbon’s soils can be considered as having low levels of pollution by these metals.
- Growth of (Perylene)(2) [PD(MNT)(2)] crystalsPublication . Afonso, M. L.; Silva, R. A. L.; Matos, Manuel; Lopes, E. B.; Coutinho, J. T.; Pereira, L. C. J.; Henriques, R. T.; Almeida, M.The conditions for [pd(mnt)(2)]he growth of [pd(mnt)(2)]Perylene) [pd(mnt)(2)] [Pd(mnt) [pd(mnt)(2)]] crystals either by chemical oxidation and electrochemical routes are [pd(mnt)(2)]escribed. The electrocrystallisation is limited by close [pd(mnt)(2)]roximity of [pd(mnt)(2)]he oxidation [pd(mnt)(2)]otentials of [pd(mnt)(2)]he [pd(mnt)(2)]erylene [pd(mnt)(2)]onor and [Pd(mnt) [pd(mnt)(2)]] - anion, and [pd(mnt)(2)]epending on [pd(mnt)(2)]he experimental conditions [pd(mnt)(2)]ifferent [pd(mnt)(2)]orphologies can be obtained. [pd(mnt)(2)]Per) [pd(mnt)(2)] [Pd(mnt) [pd(mnt)(2)]] crystals obtained by elecrocrystallisation were found [pd(mnt)(2)]o be [pd(mnt)(2)]ainly of [pd(mnt)(2)]he β-polymorph with [pd(mnt)(2)]roperties comparable [pd(mnt)(2)]o [pd(mnt)(2)]he Cu, Ni and Pt analogues [pd(mnt)(2)]reviously [pd(mnt)(2)]escribed at variance with [pd(mnt)(2)]hose obtained by chemical oxidation which are [pd(mnt)(2)]ainly of [pd(mnt)(2)]he α-polymorph.
- Determination of antioxidants and total polyphenols in cabbages (Brassica Oleracea) irrigated wiht wastewater contaminated with toxic metalsPublication . Silva, Hugo F.A.; Barreiros, Ana Maria; Silva, Nelson A. F.; Oliveira, Cristina; Coelho, Jose; Matos, ManuelWater is a natural resource essential to all kinds of life. The reuse of treated wastewater (TWW) for irrigation is a possibility with challenges to be clarified at scientific level, in particular, its use in irrigation activities due to the eventual contamination of vegetables, like cabbages (Brassica oleracea), by toxic metals and other compounds harmful to humans present in these waters. On the other hand, the use of TWW for vegetable irrigation may allow significant water saving and also providing the cultivated species with nutrients, which may dispense the use of fertilizers. In this work, vegetables such as Brassica oleracea (cabbage), were planted in a greenhouse with a controlled environment (temperature and humidity) located at ISEL campus. Part of the vegetables was irrigated with tap water, and another part with TWW from two wastewater treatment plants (WWTP) located in Lisbon´s District. One of the WWTP receives only domestic wastewater (A), whilst the other one receives industrial and domesti
- Behaviour and fate of metals in urban wastewater treatment plants: a reviewPublication . Cantinho, Paula; Matos, Manuel; Maria A. Trancoso; Santos, M. M. Correia dosThe concerns on metals in urban wastewater treatment plants (WWTPs) are mainly related to its contents in discharges to environment, namely in the final effluent and in the sludge produced. In the near future, more restrictive limits will be imposed to final effluents, due to the recent guidelines of the European Water Framework Directive (EUWFD). Concerning the sludge, at least seven metals (Cd, Cr, Cu, Hg, Ni, Pb and Zn) have been regulated in different countries, four of which were classified by EUWFD as priority substances and two of which were also classified as hazardous substances. Although WWTPs are not designed to remove metals, the study of metals behaviour in these systems is a crucial issue to develop predictive models that can help more effectively the regulation of pre-treatment requirements and contribute to optimize the systems to get more acceptable metal concentrations in its discharges. Relevant data have been published in the literature in recent decades concerning the occurrence/fate/behaviour of metals in WWTPs. However, the information is dispersed and not standardized in terms of parameters for comparing results. This work provides a critical review on this issue through a careful systematization, in tables and graphs, of the results reported in the literature, which allows its comparison and so its analysis, in order to conclude about the state of the art in this field. A summary of the main consensus, divergences and constraints found, as well as some recommendations, is presented as conclusions, aiming to contribute to a more concerted action of future research. © 2015, Islamic Azad University (IAU).
- Development of a flow injection analytical system for short chain amide determination based on a tubular bioreactor and an ammonium sensorPublication . Veríssimo, M.I.S.; Oliveira, Sara B.; Silva, Nelson A. F.; Matos, Manuel; Karmali, Amin; Gomes, Maria Teresa SRPseudomonas aeruginosa (P. aeruginosa) possesses intracellular amidase activity, which catalyses the hydrolysis of short aliphatic amides producing NH4 +, and has already been used along with an ammonium ion selective electrode for amide quantification. However, the incorporation of a biological membrane turned to be a challenging process and either the final arrangement was prone to amidase losses or the recovery of the sensor coating after the interaction took too long. In this article a flow injection system with an ammonium acoustic wave sensor is proposed, and after testing several different arrangements for the biological element, the ultimate choice consisted of the immobilization of a P. aeruginosa cell-free extract in the inner wall of a tubular glass reactor, which resulted in a reliable analytical system. Response times less than one minute and complete recovery in less than two minutes assured conveniently fast analysis. The analytical system, as long as the column was properly stored in HEPES buffer containing 2 mM β-mercaptoethanol and 1 mM benzamidine and refrigerated when not in use, could be used at least for 20 working days, along a period of one month, maintaining the initial sensitivity.