Upconverting nanoparticles as primary thermometers and power sensors

Luminescence thermometry is a spectroscopic technique for remote temperature detection based on the thermal dependence of the luminescence of phosphors, presenting numerous applications ranging from biosciences to engineering. In this work, we use the Er3+ emission of the NaGdF4/NaGdF4:Yb3+,Er3+/NaGdF4 upconverting nanoparticles upon 980 nm laser excitation to determine simultaneously the absolute temperature and the excitation power density. The Er3+ 2H11/2→4 I15/2 and 4 S3/2→4 I15/2 emission bands, which are commonly used for thermometric purposes, overlap with the 2 H9/2 →4 I13/2 emission band, which can lead to erroneous temperature readout. Applying the concept of luminescent primary thermometry to resolve the overlapping Er3+ transitions, a dual nanosensor synchronously measuring the temperature and the delivered laser pump power is successfully realized holding promising applications in laser-supported thermal therapies.publishe

Designing Ln3+-doped BiF3 particles for luminescent primary thermometry and molecular logic

The design of molecular materials suitable for disparate fields could lead to new advances in engineering applications. In this work, a series of Ln3+-doped BiF3 sub-microparticles were synthesized through microwave-assisted synthesis. The effects of doping are evaluated from the structural and morphological viewpoint. In general, increasing the Ln3+ concentration the octahedral habitus is distorted to a spheric one, and some aggregates are visible without any differences in the crystalline phase. The optical response of the samples confirms that the BiF3 materials are suitable hosts for the luminescence of the tested trivalent lanthanide (Ln3+) ions (Ln = Eu, Tb, Tm, Ho, Er, Yb). A Yb3+/ Er3+ co-doped sample is presented as an illustrative example of all-photonic molecular logic operations and primary luminescent thermometry.publishe

Exergy efficiency optimization for gas turbine based cogeneration systems

Energy degradation can be calculated by the quantification of entropy and loss of work and is a common approach in power plant performance analysis. Information about the location, amount and sourc es of system deficiencies are determined by the exergy analysis, which quantifies the exergy destruction. Micro - gas turbines are prime movers that are ideally suited for cogeneration applications due to their flexibility in providing stable and reliable power. This paper presents an exergy analysis by means of a numerical simulation of a regenerative micro - gas turbine for cogeneration applications . The main objective is to study the best configuration of each system component , considering the minimization of the system irreversibilities . Each component of the system was evaluated considering the quantitative exergy balance . Subsequently the optimization procedure was applied to the mathematical model that describes the full system. The rate of irreversibility, efficiency and flaws are highlighted for each system component and for the whole system. The effect of turbine inlet temperature change on plant exergy destruction was also evaluated . The results disclose that considerable exergy destruction occurs in the combustion chamber. Also, it was revealed that the exergy efficiency is expressively dependent on the changes of the turbine inlet temperature and increases with the latter .The authors would like to express their acknowledgments for the support given by the Portuguese F01mdation for Science and Technology (FCT) through the PhD grant SFRH/BD/62287/2009. This work was financed by National Funds-Portuguese Foundation for Science and Technology, under Strategic Project and PEst-OE/EME/UI0252/2011 and also the PEst-C/EME/UI4077/2011

Sustainable smart tags with two‐step verification for anticounterfeiting triggered by the photothermal response of upconverting nanoparticles

No abstract available.This work was developed within the scope of the projects CICECO-Aveiro Institute of Materials (UIDB/50011/2020 and UIDP/50011/2020) and Shape of Water (PTDC/NAN-PRO/3881/2020) financed by Portuguese funds through the FCT/MEC and when appropriate cofinanced by FEDER under the PT2020 Partnership Agreement. F.E.M. acknowledges the funding received from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement no. 823941. The support of the European Union’s Horizon 2020 FET Open program under grant agreement no. 801305 (NanoTBTech) is also acknowledged. R.R.S. acknowledges the financial support from the Brazilian agency FAPESP (process no. 16/06612-6).publishe

Customized luminescent multiplexed quick‐response codes as reliable temperature mobile optical sensors for eHealth and Internet of Things

The need to sense and track in real time through sustainable and multifunctional labels is exacerbated by the COVID-19 pandemic, where the simultaneous measurement of body temperature and the fast tracking of people is required. One of the big challenges is to develop effective low-cost systems that can promote healthcare provision everywhere and for that, smarter and personalized Internet of things (IoT) devices are a pathway in large exploration, toward cost reduction and sustainability. Using the concept of color-multiplexed quick response (QR) codes, customized smart labels formed by two independent layers and smart location patterns provide simultaneous tracking and multiple synchronous temperature reading with maximum sensitivity values of 8.5% K−1 in the physiological temperature range, overwhelming the state-of-the-art optical sensor for healthcare services provided electronically via the internet (eHealth) and mobile sensors (mHealth).publishe

Synthesis, characterisation and luminescent properties of lanthanide-organic polymers with picolinic and glutaric acids

Three new lanthanide(III) complexes (Ln = Sm, Tb and Eu) of picolinic and glutaric acid were prepared and characterised. The crystal structure of the complex [Sm(glu)(pic)- (H2O)2] (where Hpic and H2glu stand for picolinic and glutaric acid, respectively) was determined by single-crystal Xray diffraction. All the Ln complexes were characterised by elemental analysis, infrared spectroscopy, X-ray powder diffraction and thermoanalytical measurements. The combined Introduction The design of functional units from the molecular scale to macroscopic assemblies has emerged as a new paradigm in materials synthesis resulting in an interplay between conventional molecular chemistry and conventional solid-state science. This has been particularly clear in the development of functional materials using coordination compounds such as in the field of semiconductors technology, supramolecular machinery, microporous and hybrid materials and catalysis.[ 1] In some cases, the development of these functional materials is based on the chemistry of well-known coordination compounds as illustrated by the assembly of inorganic- organic extended lattices[2] and in the thermolysis of metal thiolato compounds to produce thin films or nanoparticles.[ 3] Metals coordinated to aromatic ambidentate ligands form a class of compounds with a wide variety of coordination modes which has long attracted the attention of chemists.[ 4] Griffith and co-workers extended this type of chemistry to the second row transition metals and, in particular, [a] Department of Chemistry, University of Aveiro, CICECO, 3810-193 Aveiro, Portugal Fax: +351-234-370-084 E-mail: [email protected] [b] Department of Physics, University of Aveiro, CICECO, 3810-193 Aveiro, Portugal [c] Department of Chemistry, University of Cambridge, Lensfield Road, CB2 1EW Cambridge, United Kingdom Supporting information for this article is available on the WWW under http://www.eurjic.org or from the author. © 2007 Wiley-VCH Verlag 4238 GmbH & Co. KGaA, Weinheim Eur. J. Inorg. Chem. 2007, 4238–4246 data show that these Ln complexes are isostructural. The effect of both organic ligands on the photoluminescent behaviour of the Sm3+, Eu3+ and Tb3+ complexes is discussed and we anticipate the possibility of controlling the photoluminescence of picolinic-containing lanthanide compounds by systematically varying the length of the bridging ligand.FCT - POCI/QUI/58377/2004Grant - SFRH/BD/17968/2004Grant - SFRH/BPD/14954/ 200

Lanthanopolyoxotungstates in silica nanoparticles: multi-wavelength photoluminescent core/shell materials

We thank Dr Marc Willinger and the RNME (National Electronic Microscopy Network, Portugal) for HRTEM images. Electronic supplementary information (ESI) available: FT-IR and FT-Raman spectra, additional HRTEM images and complementary photoluminescence spectra details, see DOI: 10.1039/b919691a.Photoluminescent lanthanopolyoxotungstate core/shell nanoparticles are prepared by the encapsulation of lanthanide-containing polyoxometalates (POMs) with amorphous silica shells. The preparation of morphological well-defined core/shell nanoparticles is achieved by the hydrolysis of tetraethoxysilane in the presence of POMs using a reverse microemulsion method. The POMs used are decatungstolanthanoates of [Ln(W(5)O(18))(2)](9-) type (Ln(III) = Eu, Gd and Tb). Photoluminescence studies show that there is efficient emission from the POM located inside the SiO(2) shells, through excitation paths that involve O --> Eu/Tb and O --> W ligand-to-metal charge transfer. It is also shown that the excitation of the POM containing europium(III) may be tuned towards longer wavelengths via an antenna effect, by coordination of an organic ligand such as 3-hydroxypicolinate. The POM/SiO(2) nanoparticles form stable suspensions in aqueous solution having the advantage of POM stabilization inside the core and the possibility of further surface grafting of chemical moieties via well known derivatization procedures for silica surfaces. These features together with the possibility of tuning the excitation wavelength by modifying the coordination sphere in the lanthanopolyoxometalate, make this strategy promising to develop a new class of optical bio-tags composed of silica nanobeads with multi-wavelength photoluminescent lanthanopolyoxometalate cores.FCT- POCI/QUI/58887/2004FCT- PTDC/ QUI/67712/2006FCT- SFRH/BD/30137/2006FCT- SFRH/BPD/14954/200

Associação de suscetibilidade dos alelos HLA-DRB1 e HLA-DQB1 com a periodontite agressiva localizada

The aim of this study was compare the class II HLA profile of generalized (GAgP) and localized aggressive periodontitis (LAgP), case group with periodontally healthy patients (CG). The sample was composed of 34 patients with GAgP (mean age = 29.4, SD ± 4.6), 8 patients with LAgP   (23.9, SD ± 5.8) and 46 CG patients (mean age= 42.8, SD ± 8.6). PCR-SSP was the method used to analysis the HLA genotype. Gene frequencies of the alleles HLA-DRB1* and HLA-DQB1* were calculated in both case and control groups. The results showed that alleles HLA-DRB1*08 and -DQB1*04 were found at a significantly (p < 0,05) higher level frequently associated with LAgP. IN conclusion, It might exist an association for susceptibility between Localized aggressive periodontitis and the HLA-DRB1*08 e HLA-DQB1*04.O objetivo deste estudo foi analisar o perfil HLA classe II em indivíduos portadores de periodontite agressiva localizada e generalizada e comparar com pacientes periodontalmente sadios (grupo controle, GC). As amostras foram compostas por 34 patientes com periodontite agressiva generalizada (média de idade = 29.4, DP ± 4.6), 8 patientes com periodontite agressiva localizada (23.9, DP ± 5.8) e 46 patientes-controle (média de idade 42.8. DP ± 8.6). As amostras foram analisadas pelo método PCR-SSP para análise de genótipo para HLA. As freqüências genéticas dos alelos HLA-DRB1* e HLA-DQB1* foram calculadas. Os resultados mostraram que os alelos HLA-DRB1*08 e -DQB1*04 estavam com sua freqüência significantemente aumentada (p < 0,05) na periodontite agressiva localizada. Sendo assim, podemos concluir que pode existir uma associação de suscetibilidade entre os alelos HLA-DRB1*08 e HLA-DQB1*04, separados ou em combinação, e a periodontite agressiva localizada.

Electrospun nanosized cellulose fibers using ionic liquids at room temperature

Aiming at replacing the noxious solvents commonly employed, ionic-liquid-based solvents have been recently explored as novel non-volatile and non-flammable media for the electrospinning of polymers. In this work, nanosized and biodegradable cellulose fibers were obtained by electrospinning at room temperature using a pure ionic liquid or a binary mixture of two selected ionic liquids. The electrospinning of 8 wt% cellulose in 1-ethyl-3-methylimidazolium acetate medium (a low viscosity and room temperature ionic liquid capable of efficiently dissolving cellulose) showed to produce electrospun fibers with average diameters within (470 ± 110) nm. With the goal of tailoring the surface tension of the spinning dope, a surface active ionic liquid was further added in a 0.10 : 0.90 mole fraction ratio. Electrospun cellulose fibers from the binary mixture composed of 1-ethyl-3-methylimidazolium acetate and 1-decyl-3-methylimidazolium chloride ionic liquids presented average diameters within (120 ± 55) nm. Scanning electron microscopy, X-ray diffraction analysis, nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy, and thermogravimetric assays were used as core methods to evaluate the structural integrity, morphology and crystallinity of the raw, electrospun, and regenerated samples of cellulose. Moreover, the photoluminescence spectra of both raw and electrospun fibers were acquired, and compared, indicating that the cellulose emitting centers are not affected by the dissolution of cellulose in ionic liquids. Finally, the use of non-volatile solvents in electrospinning coupled to a water coagulation bath allows the recovery of the ionic fluid, and represents a step forward into the search of environmentally friendly alternatives to the conventional approaches

Corpo docente da Universidade do Minho: caraterização demográgica e estratégias de rejuvenescimento

Este relatório apresenta os principais resultados da pesquisa iniciada no final de 2019, relativa ao projeto “DocentesUM -- Corpo Docente: caracterização demográfica e estratégias de rejuvenescimento”. Tem um duplo objetivo: por um lado, caracterizar em termos demográficos a situação atual do corpo docente da UMinho e, por outro lado, apresentar propostas de intervenção geracional concordantes com o desígnio de reforçar a sustentabilidade da UMinho, a médio e longo prazo. A partir da análise de dados do corpo docente da Universidade do Minho que permitiram mapear as principais tendências relativas ao volume de aposentações nos próximos anos, o relatório apresenta as principais perceções dos docentes e investigadores auscultados e procura discernir algumas opções de política para a mitigação dos efeitos do envelhecimento, no quadro de estratégias institucionais mais gerais e, de algum modo, interdisciplinares. Na prática, o estudo envolveu o cruzamento de diversas técnicas de diagnóstico de índole qualitativa (entrevistas semiestruturadas e grupos de discussão) e quantitativa (dados administrativos e inquérito por questionário), procurando favorecer a participação alargada da população académica na compreensão do problema. A informação recolhida e tratada permite concluir que o envelhecimento docente é uma preocupação estrutural para a grande maioria das Escolas/Institutos e que reflete algumas tensões já constituintes dos quotidianos da gestão académica, em particular no que se refere à atribuição de serviço docente e, em consequência, a necessidade crescente de recorrer semestralmente a contratações de pessoas em regimes mais flexíveis e pouco estáveis. Ainda que o envelhecimento seja percebido de forma muito particular em algumas escolas com dinâmicas muito específicas no que respeita ao modo de estruturar o ensino, genericamente é entendido como um fenómeno que implica atenção especial à oferta formativa e à capacidade de manutenção de certas áreas e/ou cursos. Todavia, o estudo permite identificar outros vértices colaterais do problema, nomeadamente no que se refere ao desenvolvimento dos recursos docentes e ao interesse em se repensar alguns dos enquadramentos legais existentes, em especial no que se refere à ativação de modalidades que facilitam as decisões estratégicas a respeito das carreiras dos docentes e mudança/reconfiguração dos universos culturais que caraterizam os modos de estar na academia.Conselho Geral da Universidade do Minho. UIDB/00736/202