Organic acids composition of Cydonia oblonga Miller leaf

Organic acid profiles of 36 Cydonia oblonga Miller leaf samples, from three different geographical origins of northern (Bragança and Carrazeda de Ansiães) and central Portugal (Covilhã), harvested in three collection months (June, August and October of 2006), were determined by HPLC/UV (214 nm). Quince leaves presented a common organic acid profile, composed of six constituents: oxalic, citric, malic, quinic, shikimic and fumaric acids. C. oblonga leaves total organic acid content varied from 1.6 to 25.8 g/kg dry matter (mean value of 10.5 g/kg dry matter). Quinic acid was the major compound (72.2%), followed by citric acid (13.6%). Significant differences were found in malic and quinic acids relative abundances and total organic acid contents according to collection time, which indicates a possible use of these compounds as maturity markers. Between June and August seems to be the best period to harvest quince leaves for preparation of decoctions or infusions, since organic acids total content is higher in this season

Phenolic profile of Cydonia oblonga Miller leaves

Cydonia oblonga Miller leaves phenolic compounds were analyzed by reversed-phase HPLC/DAD and HPLC/UV. Qualitative and quantitative analysis of phenolics were carried out in a total of 36 samples of quince leaves from three different geographical origins of Northern (Bragança and Carrazeda de Ansiães) and Central Portugal (Covilhã) and three collection months (June, August, and October of 2006). These leaves presented a common phenolic profile composed by nine compounds: 3-O-, 4-O- and 5-O-caffeoylquinic acids, 3,5-O-dicaffeoylquinic acid, quercetin-3-Ogalactoside, quercetin-3-O-rutinoside, kaempferol-3-O-glycoside, kaempferol-3-O-glucoside, and kaempferol-3-O-rutinoside. 5-O-caffeoylquinic acid was the major phenolic compound (36.2%), followed by quercetin 3-O-rutinoside (21.1%). Quince leaves are characterized by higher relative contents of kaempferol derivatives than fruits (pulps, peels, and seeds), especially in what concerns kaempferol-3-O-rutinoside (12.5%). C. oblonga leaves total phenolic content was very high, varying from 4.9 to 16.5 g/kg dry matter (mean value of 10.3 g/kg dry matter), indicating that these leaves can be used as a good and cheap source of bioactive constituents. Significantly differences were observed in 3-O-caffeoylquinic and 3,5-O-dicaffeoylquinic acids contents, according to geographical provenance and harvesting month, suggesting a possible use of these compounds as geographical origin and/or maturity markers

Selection of novel geopolymeric mortars for sustainable construction applications using fuzzy topsis approach

Construction is recognized as one of the most polluting and energy consuming industries worldwide, especially in developing countries. Therefore, Research and Development (R&D) of novel manufacturing technologies and green construction materials is becoming extremely compelling. This study aims at evaluating the reuse of various wastes, originated in the Kraft pulp-paper industry, as raw materials in the manufacture of novel geopolymeric (GP) mortars whose properties fundamentally depend on the target application (e.g., insulating panel, partition wall, structural element, furnishing, etc.). Five different wastes were reused as filler: Two typologies of Biomass Fly Ash, calcareous sludge, grits, and dregs. The produced samples were characterized and a multi criteria analysis, able to take into account not only the engineering properties, but also the environmental and economic aspects, has been implemented. The criteria weights were evaluated using the Delphi methodology. The fuzzy Topsis approach has been used to consider the intrinsic uncertainty related to unconventional materials, as the produced GP-mortars. The computational analysis showed that adding the considered industrial wastes as filler is strongly recommended to improve the performance of materials intended for structural applications in construction. The results revealed that the formulations containing 5 wt.% of calcareous sludge, grits, and dregs and the one containing 7.5 wt.% of calcareous sludge, grits, dregs, and Biomass Fly Ash-1 have emerged as the best alternatives. Furthermore, it resulted that the Biomass Fly Ash-2 negatively influences the structural performance and relative rank of the material. Finally, this case study clearly shows that the fuzzy Topsis multi-criteria analysis represents a valuable and easy tool to investigate construction materials (either traditional and unconventional) when an intrinsic uncertainty is related to the measurement of the quantitative and qualitative characteristics

Highly efficient lead extraction from aqueous solutions using inorganic polymer foams derived from biomass fly ash and metakaolin

This work reports a simple and safe, but powerful, route to depollute lead-containing aqueous solutions. Inorganic polymer foams (cm-size) were used as bulk-type adsorbents. The influence of the specimens' porosity and activator molarity on the foams' physical properties and on their lead extraction ability was studied. Then, the best performing samples were deeply evaluated as lead adsorbents by studying the impact of pH, lead concentration, contact time, ionic strength and solution volume. Lead sorption kinetics is strongly affected by the pollutant concentration, pH and the solution ionic strength. Under the most favourable conditions the foams showed an impressive removal capacity (105.9 mg/g at pH 5, 23 °C, C0 = 800 ppm, deionised water), surpassing all other reported values on the use of bulk-type inorganic polymers. The foams’ lead uptake is 2.3 times higher than the previous best performing bulk-type specimens (mm-size spheres), and sorption is 12.5–15 times faster. The foams can be easily regenerated using mild acidic conditions, and then reused as adsorbent, suggesting that the main adsorption mechanism is ion exchange

Red mud-based geopolymers with tailored alkali diffusion properties and pH buffering ability

This study develop novel porous red mud (RM) based geopolymers and evaluates their potential to ensure prolonged pH control. Several properties of the novel geopolymers were examined including buffering ability, alkalis leaching behaviour, mineralogical composition, microstructure and physical properties. Two experimental plans were defined to evaluate the influence of porosity and RM content on those properties. The pH values of the eluted water and geopolymers OH ions leaching have been determined over time showing that total OH ions and the leaching rate can be tailored by controlling the geopolymers porous structure and the availability of free alkaline species. The lower pH gradient over 28th d (1.64 pH units) was achieved by combining a 0.025 wt% pore forming agent (aluminium powder) with 45 wt% MK replacement by red mud. A high and prolonged buffer capacity was accomplished, proving that red mud-based geopolymers have potential to be applied as pH buffering material.This work was developed within the scope of the project CICECO-Aveiro Institute of Materials, POCI-01-0145-FEDER-007679 (FCT Ref. UID/CTM/50011/2013), financed by national funds through the FCT/MEC and when appropriate co-financed by FEDER under the PT2020 Partnership Agreement.info:eu-repo/semantics/publishedVersio

Crops on the edge of a cliff: Storage at Castro S. João das Arribas (Northwest Iberia) in the Late Antiquity

The site of Castro S. João das Arribas is placed on the edge of a cliff over the Douro river (Miranda do Douro, Northeast of Portugal). Archaeological interventions in its highest area uncovered a main occupation from Late Antiquity. On its western part a functional space was recorded, which included two small above-ground structures and abundant charred carpological remains. These were found inside ceramic vessels and spread throughout the area, suggesting its destruction occurred after a fire event. A radiocarbon date places such episode in some moment between the late 6th and the first half of the 7th century CE. Carpological results revealed an assemblage dominated by cereal grains, mostly rye (Secale cereale). Naked wheat (Triticum aestivum/durum), barley (Hordeum vulgare), common millet (Panicum miliaceum) and foxtail millet (Setaria italica) were also found but in smaller amounts. The large amount of carpological remains in the above-mentioned contexts, suggests the space was used for storage, at least between the 6th and 7th centuries CE. Although some uncertainties remain regarding how crops were stored, evidence points that they were kept in ceramic vessels, outside and inside the small storage facilities, but also in other types of containers, eventually made of perishable materials. At Castro S. João das Arribas, past communities chose a diversity of crops, however, most of them show undemanding features in terms of soil and climatic conditions. The agricultural choices could have been motivated by several factors, but cereals like rye were certainly well-suited to the environmental conditions around the settlement.LS was financially supported by a PhD grant (Norte-08-5369-FSE000057) from the University of Porto (Faculty of Sciences) and the European Social Fund, through the North Portugal Regional Operational Program “Norte 2020”, under the announcement “Aviso Norte-69-2015-15-Formaç˜ao Avançada (Programas Doutorais)”. MMS was funded by the Beatriz Galindo program as Junior Distinguished Researcher (BG20/00076). JPT was supported by national funds through the Foundationfor Science and Technology (FCT)

Innovative application for bauxite residue: red mud-based inorganic polymer spheres as pH regulators

In this study, and for the first time, red mud (RM)-based geopolymer spheres were synthesised, with varying porosity and RM content, and then their use as pH regulators was evaluated. The aluminosilicate sources of these inorganic polymers were 100% waste-based, consisting of a mixture of RM and fly ash wastes. Geopolymer spheres containing up to 60 wt.% RM were successfully produced, while higher RM contents distorted the specimens' spherical shape. Results showed that alkalis leaching from the spheres over time can be controlled by their porosity, while the RM content induces only minor changes to leaching. The RM-based spheres leached up to 0.0237 mol/dm3g of OH- ions from their structure, this being among the highest values ever reported for geopolymers. This allowed a continuous and prolonged pH buffer capacity with narrow pH decay over the 28 days (2.4 pH units), suggesting the use of the RM-based spheres as pH buffering materials in wastewater treatment and anaerobic digestion systems.publishe

Unravelling the Affinity of Alkali-Activated Fly Ash Cubic Foams towards Heavy Metals Sorption

In this work, alkali-activated fly ash-derived foams were produced at room temperature by direct foaming using aluminum powder. The 1 cm3 foams (cubes) were then evaluated as adsorbents to extract heavy metals from aqueous solutions. The foams’ selectivity towards lead, cadmium, zinc, and copper ions was evaluated in single, binary, and multicomponent ionic solutions. In the single ion assays, the foams showed much higher affinity towards lead, compared to the other heavy metals; at 10 ppm, the removal efficiency reached 91.9% for lead, 83.2% for cadmium, 74.6% for copper, and 64.6% for zinc. The greater selectivity for lead was also seen in the binary tests. The results showed that the presence of zinc is detrimental to cadmium and copper sorption, while for lead it mainly affects the sorption rate, but not the ultimate removal efficiency. In the multicomponent assays, the removal efficiency for all the heavy metals was lower than the values seen in the single ion tests. However, the superior affinity for lead was preserved. This study decreases the existing knowledge gap regarding the potential of alkali-activated materials to act as heavy metals adsorbents under different scenarios

Effect of the conservation procedure on the contents of phenolic compounds and organic acids in Chanterelle (Cantharellus cibarius) Mushroom

To check the influence of the conservation procedure in the chemical composition of chanterelle mushroom, phenolic compounds and organic acids of samples preserved under four different conditions (drying, freezing, conservation in olive oil and in vinegar) were determined. Phenolics and organic acids were analyzed by HPLC-DAD and HPLC-UV, respectively. The results showed that chanterelle is characterized by the presence of six phenolic compounds (3-, 4-, and 5-O-caffeoylquinic acid, caffeic acid, p-coumaric acid, and rutin) and five organic acids (citric, ascorbic, malic, shikimic, and fumaric acids). Samples preserved in olive oil also exhibited hydroxytyrosol, tyrosol, luteolin, and apigenin, whereas conservation in vinegar led to the detection of hydroxytyrosol, tyrosol, and tartaric acid in the analyzed samples. The conservation procedures to which chanterelle samples were subjected seem to affect the qualitative and quantitative phenolics and organic acids profiles

To practice or not to practice? Designing higher education curriculum to boost employability

One important dimension of Higher education curriculum design pertains to the inclusion of internships in study programmes. These have been generally conceptualized as learning experiences capable of bridging theoretical knowledge and hands-on experiences. The underlying pedagogical relevance is based on the premise that internships create the possibility of contextualized learning, fostering both professional growth and students’ self-esteem and pro-activity (Little, 2006). Interns are provided with the opportunity of early networking, as they enrol in practical activities and professionally interact with other people, besides their academic teachers and their graduate colleagues (Alpert, Heaney, & Kuhn, 2009; Weible, 2009). Research concerning internships has extensively reported the overwhelming positive effect of internships. Nevertheless, a more recent trend in literature has argued that little has been said concerning the relationship between internships and graduate employment or employability. Wilton (2012), for example, argues that more needs to be understood about the characteristics and specificities of internships and the extent to which such characteristics are capable of overcoming the current concern over the increase of graduates’ unemployment rates. Research conducted on the Portuguese case based on a database of 1,168 study programmes of first cycle degrees sough to redress this gap. Besides demonstrating that study programmes which include internships (cooperative education) tend to generate lower levels of unemployment than those that do not include internships, this research has suggested that the nature and structure of internships significantly impacts on graduate unemployment rates. In specific, mandatory internships tend to outperform their optional counterpart in reducing graduate unemployment levels. Moreover, thin sandwich courses also seem to be more beneficial than thick sandwich courses, suggesting that expanding and diversifying internships throughout the curriculum can reduce graduate unemployment rates. These results strongly suggest that it is not (only) the internship learning experience per se that makes the difference considering graduate employability, but (also) the way those internship experiences are organized along the study programme. This poster is, thus, focused on the nature and structure of internships, assessing their implications for higher education curriculum design. It does so by exploring the perspectives of the main stakeholders involved in internships regarding their motivations; required efforts; and expected outcomes. Empirically, the poster is based on the content analysis of semi-structured individual interviews to units coordinators and also focus groups conducted with coordinators of study programmes; internship supervisors (both academics and employers); and also interns. Qualitative analysis has been sustained by the main learning models traditionally used in research on work-based learning and aims at identifying a set of principles related with internships design, and modes of embedding them along an entire course, which may contribute to the development of graduates’ employability. Reported findings may constitute an important primer for reflection on the design of pedagogical strategies that maximize the contextual learning outputs of internships in a more systematic way, being particularly relevant for leading academics, namely those involved in curriculum design