Identificação de conflitos na delimitação da Reserva Ecológica Nacional - Caso de estudo : concelho de Nisa

Este estudo tem como objectivo a aplicação de uma metodologia para a delimitação da REN do concelho de Nisa, baseada em Sistemas de Informação Geográfica (SIG) e sua comparação com a REN legalmente aprovada

Photonic superdiffusive motion in resonance radiation trapping

In this work we consider the relation between the jump length probability density function and the line shape function in resonance radiation trapping in atomic vapors. The two-sided jump length probability density function suitable for a unidimensional formulation of radiative transfer is also derived. As a side result, a procedure to obtain the Maxwell distribution of velocities from the Maxwell-Boltzmann distribution of speeds was obtained. General relations that give the asymptotic jump length behavior and the Lévy flight parameter niu for any line shape are obtained. The results are applied to generalized Doppler, generalized Lorentz, and Voigt line shape functions. It is concluded that the lighter the tail of the line shape function, the less heavy the tail of the jump length probability density function, although this tail is always heavy, with niu <= 1

Click-Derived Triazoles and Triazolylidenes of Manganese for Electrocatalytic Reduction of CO2

022162, CEECIND/00509/2017, PTDC/QUI-QIN/28151/2017, RECI/BBB-BEP/0124/2012, SFRH/BD/131955/2017, UIDB/00100/2020, UIDB/04378/2020, UIDB/04612/2020, UIDP/00100/2020, UIDP/04046/2020, UIDP/04378/2020, UIDP/50006/2020, UIPD/04612/2020 Funding Information: This research was funded by FUNDA??O DE CI?NCIA E TECNOLOGIA, FCT, grant numbers: PTDC/QUI-QIN/28151/2017, SFRH/BD/131955/2017, CEECIND/00509/2017. The MOSTMICRO-ITQB was funded by UIDB/04612/2020 and UIPD/04612/2020. The NMR spectrome-ters at CERMAX were funded by 022162. LAQV and UCIBIO were funded by UIDB/50006/2020, UIDP/50006/2020, UIDB/04378/2020, and UIDP/04378/2020. The X-ray infrastructure was funded by RECI/BBB-BEP/0124/2012. The BioISI was funded by UIDB/04046/2020, UIDP/04046/2020, UIDB/00100/2020, and UIDP/00100/2020. We thank C. Almeida for elemental analysis at ITQB laboratories. Funding Information: Funding: This research was funded by FUNDAÇÃO DE CIÊNCIA E TECNOLOGIA, FCT, grant numbers: PTDC/QUI-QIN/28151/2017, SFRH/BD/131955/2017, CEECIND/00509/2017. The MOSTMICRO-ITQB was funded by UIDB/04612/2020 and UIPD/04612/2020. The NMR spectrometers at CERMAX were funded by 022162. LAQV and UCIBIO were funded by UIDB/50006/2020, UIDP/50006/2020, UIDB/04378/2020, and UIDP/04378/2020. The X-ray infrastructure was funded by RECI/BBB-BEP/0124/2012. The BioISI was funded by UIDB/04046/2020, UIDP/04046/2020, UIDB/00100/2020, and UIDP/00100/2020. Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland.A series of new fac-[Mn(L)(CO)3 Br] complexes where L is a bidentate chelating ligand containing mixed mesoionic triazolylidene-pyridine (MICˆpy, 1), triazolylidene-triazole (MICˆtrz, 2), and triazole-pyridine (trzˆpy, 3) ligands have been prepared and fully characterized, including the single crystal X-ray diffraction studies of 1 and 2. The abilities of 1–3 and complex fac-[Mn(MICˆMIC)(CO)3 Br] (4) to catalyze the electroreduction of CO2 has been assessed for the first time. It was found that all complexes displayed a current increase under CO2 atmosphere, being 3 and 4 the most active complexes. Complex 3, bearing a NˆN-based ligand exhibited a good efficiency and an excellent selectivity for reducing CO2 to CO in the presence of 1.0 M of water, at low overpotential. Interestingly, complex 4 containing the strongly electron donating di-imidazolylidene ligand exhibited comparable activity to 3, when the experiments were performed in neat acetonitrile at slightly higher overpotential (−1.86 vs. −2.14 V).publishersversionpublishe

Mechanistic insights into the electrochemical reduction of CO2 to CO on Ni(salphen) complexes

LA/P/0056/2020. The NMR spectrometers are part of the National NMR Network (PTNMR) and are partially supported by Infrastructure Project No 022161 (co-financed by FEDER through COMPETE 2020, POCI and PORL and FCT through PIDDAC). FCT is acknowledged for PTDCQUI-QIN0252_2021 (PNM). The CARISMA COST action CM1205 is acknowledged. MJC thanks N. A. G. Bandeira for technical assistance. The CATSUS doctoral programme is also acknowledged. Publisher Copyright: © 2023 The Royal Society of Chemistry.Cyclic voltammetry and bulk electrolysis showed that [Ni(ii)(salphen)] [1], [Ni(ii)(tBu-salphen)] [2], and a binuclear Ni(ii) compound combining salphen and tBu-salphen [3] react with CO2 to yield a metal-carbonyl species that is stable under an oxygen free atmosphere. Upon exposure to air, a stoichiometric amount of CO is released (detected by gas chromatography) and protonation regenerates the initial complex. To shed light on the mechanism of CO2 reduction and O2-dependent CO release by [1], UV-vis, EPR and SEC-IR spectroscopy studies complemented with DFT calculations were performed. It is proposed that the mono reduced [Ni(i)(salphen)]−, 2[1]−, formed a CO2 complex, 2[1(CO2)]−, which was then further reduced to 3[1(CO2)]2−. After addition of two protons, the coordinated CO2 was reduced to CO and released, regenerating 1[1]. Alternatively, 2[1(CO2)]− is protonated and then reduced to the same intermediate as before, continuing the same way. In the second cycle, the CO released competed with CO2 and coordinated to 2[1]− much more strongly, thereby deactivating the system. The new 2[1(CO)]− was reduced to 3[1(CO)]2− which was identified by comparison of experimental spectroscopic (UV-vis, EPR, SEC-IR) data with DFT calculated parameters.publishersversionpublishe

Diversification of EPR signatures in site directed spin labeling using a beta-phosphorylated nitroxide

Site Directed Spin Labeling (SDSL) combined with EPR spectroscopy is a very powerful approach to investigate structural transitions in proteins in particular flexible or even disordered ones. Conventional spin labels are based on nitroxide derivatives leading to classical 3-line spectra whose spectral shapes are indicative of the environment of the labels and thus constitute good reporters of structural modifications. However, the similarity of these spectral shapes precludes probing two regions of a protein or two partner proteins simultaneously. To overcome the limitation due to the weak diversity of nitroxide label EPR spectral shapes, we designed a new spin label based on a β-phosphorylated nitroxide giving 6-line spectra. This paper describes the synthesis of this new spin label, its grafting at four different positions of a model disordered protein able to undergo an induced α-helical folding and its characterization by EPR spectroscopy. For comparative purposes, a classical nitroxide has been grafted at the same positions of the model protein. The ability of the new label to report on structural transitions was evaluated by analyzing the spectral shape modifications induced either by the presence of a secondary structure stabilizer (trifluoroethanol) or by the presence of a partner protein. Taken together the results demonstrate that the new phosphorylated label gives a very distinguishable signature which is able to report from subtle to larger structural transitions, as efficiently as the classical spin label. As a complementary approach, molecular dynamics (MD) calculations were performed to gain further insights into the binding process between the labeled NTAIL and PXD. MD calculations revealed that the new label does not disturb the interaction between the two partner proteins and reinforced the conclusion on its ability to probe different local environments in a protein. Taken together this study represents an important step forward in the extension of the panoply of SDSL-EPR approaches. This journal is © 2014 the Owner Societies

Assessing estuarine environmental quality using fish-based indices: Performance evaluation under climatic instability

http://www.sciencedirect.com/science/article/B6V6N-4TFDY7X-2/2/c9f9bbc565621cbb798d6d663e74a8f

Instagram: A gimmick or a serious reputation builder in the airline business?

The purpose of the research is to shed light on the interrelatedness between Instagram and corporate reputation on the one hand and customer service expectations on the other. A conceptual model is proposed to be tested in the context of the civil aviation economy. A national flagship airline company was chosen in which to conduct the research. An online questionnaire was made available and 283 responses were collected. Partial Least Squares Structural Equation Modelling (PLS-SEM) was used to test research hypotheses derived from the literature. The novelty of the work is in the scarce research found when scrutinizing the literature on possible links between Instagram and airline corporate reputation. The study found there to be a positive correlation between social media usage and corporate reputation in the airline sector. Future research needs to replicate this study across other airlines to ascertain the external validity of the current study and its potential for extrapolation.info:eu-repo/semantics/acceptedVersio

Influence of the apical enlargement size on the endotoxin level reduction of dental root canals

Gram-negative bacteria play an essential role in endodontic infections because they have virulence factors such as endotoxin. Due to its potential cytotoxic activity, special attention has been given to the removal/neutralization of this endotoxin in the root canal system. OBJECTIVE: The aim of this study was to evaluate the influence of the apical enlargement size (AES) by using rotary instruments on the endotoxin level reduction of dental root canals. MATERIAL AND METHODS: Forty root canals of the mandibular premolar teeth were used. Escherichia coli endotoxin (055: B55) was inoculated into thirty root canals. Ten teeth served as the negative control group. After the incubation period, the first endotoxin samples were collected from the root canals with a sterile/apyrogenic paper point for the analysis of the endotoxin units (EU/mL) present before instrumentation (S1). Specimen instrumentation was performed with the Mtwo(®) rotary system in the sequence 10/.04, 15/.05, 20/.06, 25/.06, 30/.05, 35/.04 and 40/.04. To monitor the effectiveness of increasing apical enlargement on endotoxin removal, the second endotoxin samples were collected from all the root canals after instrumentation with the following instruments: #25/.06- (S2); #30/.05- (S3); # 35/.04- (S4); and #40/.04- (S5). Limulus amebocyte lysate (LAL) was used to quantify the levels of endotoxin. The results were statistically compared by using repeated measures of ANOVA with post hoc Tukey testing. RESULTS: Increasing levels of endotoxin removal was achieved by large sized apical enlargement: S2 (AES #25/.06)- 89.2%, S3 (AES #30/.05)- 95.9%, S4 (AES #35/.04)- 97.8% and S5 (AES #40/.04)- 98.2%. Substantial reduction of endotoxin content was obtained in S4 and S5 compared to S2 (p<0.05), however, the root canal preparation was not able to eliminate the endotoxin. CONCLUSIONS: Under the conditions of this study, it was concluded that the reduction of endotoxin levels of the dental root canals could be predicted by increasing the apical enlargement size

The influence of surface finishing on laser heat treatments of a tool steel

Laser heat treatments (LHT) has received growing attention in the last years because of highly localized precision and manufacturing efficiency related to laser processing of moulds steel. Due of its strong resistance and ability to maintain hardness and strength at high temperatures, AISI P20 steel is one of the most widely used tool steel in the plastics injection mould industry. This work presents an experimental investigation on LHT using P20 mod. steel produced with different surface finishes. After mechanical surface finishing, the diode laser beam with 15 mm width was applied to the P20 specimens at 1060 °C using a feed rate of 8.8 mms-1in an air and argon ambient. The influence of different LHT atmosphere conditions and specimen initial surface finishing on characteristics such as final roughness, microhardness and microstructure were comprehensively analyzed. The use of a controlled atmosphere during processing showed an increment in depth and hardness values of samples. Through 3D profilometer, it was possible to determine the samples roughness. Results showed that lower average roughness leads to higher hardness values close to the surface, while higher average roughness lead to a deeper heat-treated zone. Macroscopical analysis revealed the depth and width afftected by LHT. The microhardness results showed an increment from 300 HV to around 750 HV on laser heat-treated zone using a controlled environment. Optical microscopy analysed the microstructural changes into martensite between LHT and non LHT zones for all samplespublishe