Mini-review and discussion of a potential standardization

Gonçalves, G., Andriolo, U., Gonçalves, L. M. S., Sobral, P., & Bessa, F. (2022). Beach litter survey by drones: Mini-review and discussion of a potential standardization. Environmental Pollution, 315(15 December), 1-8. [120370]. https://doi.org/10.1016/j.envpol.2022.120370The abundance of beach litter has been increasing globally during the last decades, and it is an issue of global concern. A new survey strategy, based on uncrewed aerial vehicles (UAV, aka drones), has been recently adopted to improve the monitoring of beach macro-litter items abundance and distribution. This work identified and analysed the 15 studies that used drone for beach litter surveys on an operational basis. The analysis of technical parameters for drone flight deployment revealed that flight altitude varied between 5 and 40 m. The analysis of final assessments showed that, through manual and/or automated items detection on images, most of studies provided litter bulk characteristics (type, material and size), along with litter distribution maps. The potential standardization of drone-based litter survey would allow a comparison among surveys, however it seems difficult to propose a standard set of flight parameters, given the wide variety of coastal environments, the different devices available, and the diverse objectives of drone-based litter surveys. On the other hand, in our view, a set of common outcomes can be proposed, based on the grid mapping process, which can be easily generated following the procedure indicated in the paper. This work sets the ground for the development of a standardized protocol for drone litter data collection, analysis and assessments. This would allow the provision of broad scale comparative studies to support coastal management at both national and international scales.publishersversionpublishe

Production and characterization of a new dextrin based hydrogel

Dextrin is a polymer composed of α-(1→4) D-glucose units produced by partial hydrolysis of starch. In this work, the transesterification of the soluble polysaccharide with vinyl acrylate (VA) was carried out in anhydrous dimethylsulfoxide (DMSO). The effect of the water activity and of the enzyme Proleather, on the reaction rates, was analysed. Different degrees of substitution (DS) ranging from ca. 10% to 70% were obtained by controlling the molar ratio of VA to dextrin. Gels were obtained by free radical polymerization of dextrin-VA, with different degrees of substitution and monomer concentration, in water. A comprehensive solid state-NMR analysis of the hydrogels was performed. These hydrogels are being developed as scaffold materials for bioactive molecule and cell delivery, tissue engineering and a variety of other biomedical applications

Characterization of dextrin hydrogels by FTIR spectroscopy and solid state NMR spectroscopy

Fourier transform infrared (FTIR) and 13C solid state nuclear magnetic resonance (NMR) spectroscopy were used to study dextrin structural changes occurring upon hydrogel formation by vinyl acrylate (VA) grafting and subsequent free radical polymerization. The degrees of VA substitution (DS) and polymerization (DP) were quantified up to 40%VA by FTIR intensity measurements and partial least squares (PLS)/FTIR, the latter being a faster and less error-prone method. Above 40%VA, both parameters are underestimated by FTIR. A spin counting NMR experiment showed high carbon observabilities for hydrogels and improved PLS/NMR models were achieved for DS and DP determination. Alternative NMR integration methods are hindered by the broad VA peaks and need for area correction, due to their CP dynamics. NMR changes in C1 profile showed that a single helical conformation predominates at lower %VA, being replaced by disordered conformations as %VA increases. Furthermore, a correlation FTIR/NMR study indicated that ring conformations are significantly affected in hydrogels, compared to unpolymerized dextrin.Funding is acknowledged from the Foundation for Science and Technology, Portugal, for project POCI/QUI/ 56229/2004 and grants for H.G. and C.G. (SFRH/22242/ 2005). The authors also wish to acknowledge CICECO for partial funding of this work.Fundação para a Ciência e a Tecnologia (FCT

Optically active aziridine esters by nucleophilic addition of nitrogen heterocycles to a chiral 2H-azirine-2-carboxylic ester

Chiral enriched ethyl 3-methyl-2H-azirine-2-carboxylate acts as an efficient alkylating agent for a variety of five membered aromatic nitrogen heterocycles.Fundação para a Ciência e Tecnologia - POCTI/32723/QUI/2000. FEDER

Preparation of Poly(vinyl chloride) Latexes Using a Dual Surfactant System: The Effect in the Particle Size Distribution

The control of the average particle size and size distribution in the emulsion polymerization of vinyl chloride monomer is an important parameter to determine, not only the latex characteristics, but also the properties of the final dispersion powder in several industrial applications. It is possible to manipulate the particle size distribution (PSD) by applying a mixture of an anionic surfactant-fatty alcohol before the start of the free radical polymerization. Contrary to the procedures of the miniemulsion and the derivative diffusional swelling techniques, no kind of high shear is applied to the monomer and/or surfactant mixtures. In fact, the concentration and selection of the anionic surfactant, together with the fatty-alcohol, can play an interesting role on the final PSD of the polymer's particlesFCT; contract grant number SFRH/BDE/15534/200

Characterization of suspension poly(vinyl chloride) resins and narrow polystyrene standards by size exclusion chromatography with multiple detectors: Online right angle laser-light scattering and differential viscometric detectors

This work reports the utilization of a multi-detector size chromatography for the characterization of poly(vinyl chloride) (PVC) resins prepared by suspension polymerization in the range of temperatures between 21 and 75 °C. The chromatography equipment offers the possibility of analyzing the samples in terms of their absolute molecular mass using a combination of three detectors (TriSEC): right angle light scattering (RALLS), a differential viscometer (DV) and refractive index (RI). The PVC resins were fully characterized concerning the molecular weight distribution (MWD), its dependence with intrinsic viscosity ([eta]) and molecular sizes (radius of gyration, Rg and hydrodynamic radius, Rh). Additionally, it is also presented the characterization of polystyrene narrow standards serving as reference polymers.http://www.sciencedirect.com/science/article/B6TWW-4HHGNVH-4/1/170871b80274a89470f2a790d3ed999

Natural pigments of anthocyanin and betalain for coloring soy-based yogurt alternative

The aim of this work was to evaluate the color stability of betalain- and anthocyanin-rich extracts in yogurt-like fermented soy, in order to develop a preliminary understanding of how these pigments behave in this type of food system during storage for 21 days at 4 °C. Thus, the extracts of red beetroot, opuntia, hibiscus and red radish were integrated into the yogurt-like fermented soy in two different ways—directly after lyophilization, and encapsulated in nanosystems based in soybean lecithin—as this approach has never been used to further increase the value and potential of the dairy-free alternatives of yogurt-like fermented soy. The results showed that non-encapsulated betalain-rich extracts from red radish are the most promising for coloring yogurt-like fermented soy. However, encapsulated opuntia extracts can also be an alternative to supplement the soy fermented beverages with betalains, without changing significantly the color of the system but giving all its health benefits, due to the protection of the pigments by nanoencapsulation.This research was funded by COMPETE 2020 program, co-financed by the FEDER and the European Union, PTDC/ASP-AGR/30154/2017 (POCI-01-0145-FEDER-030154). Foundation for Science and Technology (FCT, Portugal), and FEDER-COMPETE-QREN-EU funded research centers CQ-UM (UID/QUI/00686/2019), CF-UM-UP (UID/FIS/04650/2019) and REQUIMTE (UIDB/50006/2020)

High affinity of 3D spongin scaffold towards Hg(II) in real waters

This study focuses on the ability of commercial natural bath sponges, which are made from the skeletons of marine sponges, to sorb Hg from natural waters. The main component of these bath sponges is spongin, which is a protein-based material, closely related to collagen, offering a plenitude of reactive sites from the great variety of amino acids in the protein chains, where the Hg ions can sorb. For a dose of 40 mg L-1 and initial concentration of 50 μg L-1 of Hg(II), marine spongin (MS) removed ~90% of Hg from 3 water matrixes (ultrapure, bottled, and seawater), corresponding to a residual concentration of ~5 μg L-1, which tends to the recommend value for drinking water of 1 μg L-1. This value was maintained even by increasing the MS dosage, suggesting the existence of a gradient concentration threshold below which the Hg sorption mechanism halts. Kinetic modelling showed that the Pseudo Second-Order equation was the best fit for all the water matrixes, which indicates that the sorption mechanism relies most probably on chemical interactions between the functional groups of spongin and the Hg ions. This material can also be regenerated in HNO3 and reused for Hg sorption, with marginal losses in efficiency, at least for 3 consecutive cycles.publishe

A framework for cooperative engineering

This paper discusses a framework for Cooperative Engineering (CE) and itsprototype implementation. Cooperative Engineering concerns the application ofConcurrent Engineering techniques to the design and development of products and oftheir manufacturing systems by a network of companies coming together exclusively forthat purpose. CE is a common practice in many industries such as automotive, aerospace,shipbuilding, defence, and pharmaceutical. This framework provides a formal model forCE. This is done in the context of distributed hybrid systems (DHS), a modelling andcontrol framework for networked systems introduced recently by the control andcomputer science communities

Valorization of plant extracts by encapsulation in lipid nanosystems for application as potential insecticides

Plants have been used for centuries to treat diseases and are considered an important source of new antimicrobial agents. Plant extracts can be obtained and their composition determined, being widely employed in the pharmaceutical and cosmetic industries. A less explored and potential application is the use as green insecticides/insect repellents, as an alternative to current pesticides. Despite the desirable properties, many of the isolated components (phytochemicals) present limitations on their use, due to high volatility and easy degradation when exposed to air. Nanoencapsulation techniques arise as promising strategies to allow the preservation and controlled release of plant extracts. In this work, a series of plant materials, Tamus communis L., Tagetes patula L. and Ruta graveolens L., were subjected to Soxhlet extraction using various solvents and times of extraction. The extracts obtained were submitted to biological studies, to assess their potential against the insect cell line Sf9. Encapsulation assays in lipid nanosystems were carried out, with encapsulation efficiencies higher than 70%.This research was funded by Foundation for Science and Technology (FCT) for financial support to the research centres CQ/UM (UID/QUI/00686/2016 and UID/QUI/00686/2019) and CF-UM-UP (UID/FIS/04650/2019). Funding by FCT, COMPETE2020 and FEDER through project PTDC/ASP-AGR/30154/2017 (POCI-01-0145-FEDER-030154) is also acknowledged. The NMR spectrometer Bruker Avance III 400 (part of the National NMR Network) was financed by FCT and FEDER