Julio Pedrosa de Jesus

University of Aveiro | UA · CICECO - Centre for Research in Ceramics and Composite Materials

Pedrosa, J., Leite, C., Rosa, M. J., Pinho, I., Vieira, C., & Marinho, P. (2022). Avaliação de Aprendizagens em Instituições Educativas. Fundação Calouste Gulbenkian. https://cdn.gulbenkian.pt/wp-content/uploads/2022/10/AAIE_Gulbenkian_DIGITAL-06-05-22_low.pdf

A avaliação das aprendizagens, enquanto dimensão organizadora do currículo e das práticas pedagógicas, assume uma relevância transversal a todos os níveis de educação. “Medir” e “aferir” as aprendizagens pode constituir-se, assim, uma ferramenta que permita alinhar os diversos atores de todo o sistema, com vista à melhoria da aprendizagem e a artic...

The Portuguese-speaking countries (PSC) have a population of close to 250 million and occupy an area of about 10.7 million square kilometers across four continents. Most of these countries are rich in biodiversity and at the same time have a human development Index below the global average. This network of countries has a great potential to promote...

Neste início de século vem se construindo um consenso de que as universidades são agentes estratégicos para a promoção da sustentabilidade por diversas razões como: (1) a necessidade de reduzir o impacto ambiental decorrente de suas atividades; (2) o fato de serem instituições promotoras de inovação; (3) o seu papel formador de lideranças, professo...

Chromated copper arsenate (CCA) was widespread used as a chemical wood preservative with application in the construction of playground equipment, fences, jetties, and naval. Environmental protection agency (EPA) had limited the use of CCA-treated wood on 2002, due to probable implications on both human and environmental health. Although this fact,...

This study shows how 152 researchers from several research centers of a Portuguese university perceive the facilitators and barriers to knowledge management. Three domains are considered – knowledge gathering, creation, and diffusion. Three dimensions of barriers and facilitators were considered – individuals, socio-organizational processes, and te...

The purpose of this work was to assess the acute toxicity on male mice to a chromated copper arsenate (CCA) solution, a widespread wood preservative used in building industry until 2002. Animals were subcutaneously injected with CCA (7.2mg/kg arsenic and 10.2mg/kg chromium per body weight), CrO(3) (10.2mg/kg), As(2)O(5) (7.2mg/kg) and NaCl (0.9%) p...

Chromium copper arsenate (CCA) was used for the protection of wood building materials until the restriction by EPA in 2002. During a short period of time 14-24h, a comparative nephrotoxicity study was performed regarding the effects of CCA and its compounds per se. Histopathological and histochemical features were correlated with the concentration...

The purpose of this work was to assess the acute toxicity on male mice to a chromated copper arsen-ate (CCA) solution, a widespread wood preservative used in building industry until 2002. Animals were subcutaneously injected with CCA (7.2 mg/kg arsenic and 10.2 mg/kg chromium per body weight), CrO 3 (10.2 mg/kg), As 2 O 5 (7.2 mg/kg) and NaCl (0.9%...

Bis(ethylenediamine)(oxalato)rhodium(III) Perchlorate cis-Bis(ethylenediamine)Dinitrorhodium(III)Nitrate cis-Dichlorobis(ethylenediamine)rhodium (III)Chloride Hydrate

An overview of the chemical strategies developed in our laboratories to obtain welldefined BiVO4 particles is presented. The methods rely on the thermal treatment (including hydrothermal conditions) of aqueous solutions containing bismuth(III) cations, vanadium(V) species and organic ligands. The use of distinct polyaminocarboxylates and cyclodextr...

Cr(V) species are formed during the intracellular reduction of Cr(VI), a ubiquitous environmental pollutant. In this study, the acute toxicity of a physiologically stable Cr(V) compound, [CrV-BT](2-) (BT = bis(hydroxyethyl)aminotris(hydroxymethyl)methane) was investigated in the male reproductive system of sexually mature 60-day-old male ICR-CD1 mi...

Transport of macromolecules from the interstitial testis tissue to cells at the adlumenal compartment of the seminiferous epithelium occurs naturally through Sertoli cells. In previous studies we have shown that Cr(V) intoxication disturbed spermatogenesis in mice. To test if Sertoli cells are affected by chromium, a well proved carcinogen, the upt...

Novel non-stoichiometric mixed lead and tin niobates with the pyrochlore structure have been synthesized via a solid-state route. The materials have been characterized by bulk chemical analysis, single-crystal and powder X-ray diffraction, 207Pb, 119Sn and 93Nb (single and triple quantum) solid-state NMR spectroscopy. The structures of the new non-...

The synthesis and structural characterisation of the complex [Cr([14]aneN4)(O-dmso)Cl](PF6)2·dmso is reported. The structural studies were carried out in gas-phase by electrospray mass spectrometry (ESMS) and in the solid state by single crystal X-ray diffraction. The metal complex shows a distorted octahedral coordination environment with the macr...

Chromium toxicity is strongly dependent on its oxidation state. Cr(VI) is carcinogenic and mutagenic, although its in vivo and in vitro toxic effects are related to its intracellular fate. Inside the cells, Cr(VI) is rapidly reduced to stable Cr(III). As Cr(V) and Cr(IV) species have been reported to be formed in the Cr(VI) reduction pathways, Cr(V...

) was investigated for its solubility in water or aqueous NaOH, for its stability when stored in the form of a solution in 5% NaOH, and for the physical properties and bondability of formulations prepared by incorporation of tannins into a PF resin. The extract is poorly soluble even in aqueous NaOH and its reactivity towards formaldehyde increases...

The functional integrity of the blood-testis barrier (BTB) in male mice exposed to Cr(V) was studied in order to clarify the mechanism underlying testicular injury. Adult male mice were subcutaneously injected repeated doses of 8.02 micromol (0.5 ml) of Cr/mouse.day for 5 days. Animals receiving a similar volume of bis(hydroxyethyl)-aminotris(hydro...

The chemical composition of maritime pine (Pinus pinaster) bark and of alkaline bark extracts has been investigated with bark from trees grown in Portugal. Bark is composed of lignin and polyphenolics (ca. 44%), polysaccharides (ca. 39%), dichoromethane, ethanol and water extractives (ca. 17%) and ashes (ca. 1%). The lignin content determined by th...

This work describes the very expeditious combustion synthesis of Pb(Mg1/3Nb2/3)O3 perovskite powders from mixtures of Pb(NO3)2, Mg(NO3)2·6H2O and Nb2O5, as cation precursors, and urea as fuel. The powders produced were characterized by XRD, SEM (EDS), and ICP and MAS NMR spectroscopies. Since, with this method, exposure to high temperatures is redu...

The preparation of hollow particles of ZnO by calcination of hydrozincite coated poly(styrene) beads is reported. Synthetic studies have been performed on such polymer/inorganic composite precursors in order to establish the optimum conditions for the preparation of the ZnO particles. The morphological properties of the powders were characterised b...

Cr(VI), the highest oxidation state for chromium, is a carcinogenic and mutagenic agent. In vivo and in vitro Cr(VI) toxic effects are related to its intracellular fate. Once inside the cell it is reduced to stable Cr(III) by cysteine, glutathione and ascorbic acid. Additionally, as Cr(V) and/or Cr(IV) intermediates have been reported in Cr(VI) rea...

The synthesis and the structural characterization of tin niobates Sn1+xNb2O6+x, x=0.0, 0.5, and 1.0, are reported. The materials have been characterized by bulk chemical analysis, single-crystal and powder X-ray diffraction, and 119Sn Mössbauer and 93Nb and 119Sn solid-state NMR spectroscopies. SnNb2O6 is a synthetic analog of the rare mineral foor...

The complexes [Ru([9]aneS3)(dppz)Cl]Cl 1 and [Ru([12]aneS4)(dppz)]Cl2 2 ([9]aneS3 = 1,4,7- trithiaciclononane and [12]aneS4 = 1,4,7,10-tetrathiaciclododecane) were synthesised and fully characterised. These complexes belong to a small family of dipyridophenazine complexes with non-polypyridyl ancillary ligands . Interaction studies of these complex...

Pb(Mg1/3Nb2/3)O3 (PMN), a well-known relaxor ferroelectric material, and a related pyrochlore phase have been studied by single- and triple-quantum 93Nb MAS NMR spectroscopy. The assignment of the NMR resonances has been attempted.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and...

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and...

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and...

The magnitude of the circular dichroism of (S)-aspartic acid in aqueous solutions at a fixed wavelength varies with the addition of strong base. This laboratory experiment consists of the circular dichroism spectrophotometric acid-base titration of (S)-aspartic acid in dilute aqueous solutions, and the use of the resulting data to determine the ion...

A new hexaniobate complex with chromium(III) was prepared and characterised by analytical and spectroscopic techniques. The compound is a violet, non-crystalline solid, formulated as [Cr2(μ-OH)(H3Nb6O19)(en)3(H2O)]. It was synthesised in aqueous solution by reaction of [Cr(en)3], en = ethylenediammine, with the hexaniobate anion [Nb6O19], at pH 8....

The second example of a microporous framework stannosilicate with a known structure (AV-7) has been reported. The structure of AV-7, which is very similar to the structure of both the zirconosilicate mineral kostylevite and the previously reported microporous titanosilicate UND-1, has been studied by the Rietveld method and further characterised by...

Pb(Mg1/3Nb2/3)O3 (PMN), a well-known relaxor ferroelectric material, and a related pyrochlore phase have been studied by single- and triple-quantum 93Nb MAS NMR spectroscopy. The assignment of the NMR resonances has been attempted.

A large number of new [RuII([9]aneS3)(L)Cl]+ complexes (where L is a polypyridyl bidentate ligand) were synthesized from the precursor [Ru([9]aneS3)(dmso)Cl2] in the search for new DNA intercalators. The ancillary ligands used have different molecular architectures which include cross bridges, pyridyl units, phenanthroline and diamine derivatives....

Wood, macromolecular and simple model compounds, were reacted with CrO3 or K2CrO4 aqueous solutions. Extracted lignin, guaiacol, vanillin, vanillyl alcohol and homovanillyl alcohol were chosen as model compounds for lignin, whilst cellulose, gum Ghatti, xylan, extracted hemicellulose from pine, methyl-β-D-glucopyranoside and methyl-β-cellobioside w...

Hexavalent chromium solutions at two pH levels (about 1.3 and 7.8) were reacted with wood, gum ghatti, lignin, cellulose and simple model compounds representing wood chemical structures (guaiacol, vanillin, vanillyl alcohol, homovanillyl alcohol, methyl-(β-D-glucoside, and methyl-β-cellobioside). Reaction products were isolated and characterised by...

The reaction between cis-[Ru(dmso)Cl2] (dmso=dimethylsulfoxide) and the macrocycle 1,4,7,10-tetrathiacyclododecane ([12]aneS4) gives the complex cation [Ru([12]aneS4)(dmso)Cl]+. A new series of RuII([12]aneS4) complexes were obtained by replacing the dmso and the chlorine ligands with polypyridylic or related monodentate ligands. Complexes with the...

The synthesis, structural characterisation and catalytic activity in tert-butanol dehydration of microporous titanoniobosilicate ETNbS-10 are reported.

The thermal decomposition of the tetrabutylammonium (TBA) salts (TBA)4H3[PW11O39] and (TBA)4Hx[PW11M(H2O)O39]·nH2O, x = 3-(oxidation number of M), M = Mn(II), Co(II), Ni(II), Cu(II) or Fe(III), n = 0–3, has been studied by thermal analyses and the decomposition products identified by powder X-ray diffraction, FTIR and NMR spectroscopy. The organic...

The aim of this study was to fix chromium chemically in wood from trivalent chromium solutions. Chromium(III) nitrate, chloride and sulphate salts were applied, both in aqueous and in methanolic solutions. To improve chromium fixation metallic zinc was used as a strong reductant to generate labile Cr(LI) species from Cr(III), and base was added (Na...

Pb(Mg1/3Nb2/3)O3 (PMN), a well-known relaxor ferroelectric material, and a related pyrochlore phase have been studied by single- and triple-quantum 93Nb MAS NMR spectroscopy. The assignment of the NMR resonances has been attempted.

Cyclic voltammetry was used to study, in aqueous solution (pH 2–6), polyoxotungstates with the Keggin structure with the general formula α-[XW11M(H2O)O39]n−, X=P, Si, B and M=Cr(III), Fe(III), Co(II,III), Ni(II). The results provide valuable information on the comparative ease of reduction of the several species studied and on the stability of the...

The synthesis and structural characterization of AV-1 (Aveiro microporous solid no. 1), the first synthetic microporous yttrium silicate containing stoichiometric amounts of framework sodium (and yttrium) cations, are reported. AV-1, Na4K2Y2Si16O38·10H2O, possesses the structure of the rare mineral montregianite. The synthesis and structural charac...

Two crystalline forms of d-mannitol precipitated at room temperature from acetone/water mixtures in the presence of the Keggin heteropolyanions [PW12O40]3− or [SiW12O40]4− were identified by X-ray powder diffraction and solid state 13C NMR spectroscopy. In the presence of [SiW12O40]4− (acid or K+ salt) the α polymorph was the only form obtained. Th...

A new approach for pulp bleaching using oxygen in the presence of a polyoxometalate (POM), such as the heptamolybdopentavanadophosphate anion (HPA-5), in aqueous and nonaqueous media is presented. The selective oxidation of residual lignin in the pulp/POM/O2 system is catalyzed by HPA-5 oxidized species. The reduced forms of HPA-5 after the reactio...

The catalytic effect of molybdovanadophosphate heteropolyanions (HPAs) on the delignification of wood by oxygen has been investigated. The VO2+ ions produced via the dissociation of HPA in acidic conditions are suggested to have a much stronger catalytic effect on the oxidation of lignin than parent HPA. The influence on delignification of the pH,...

The synthesis of a series of RuII complexes with the thioether ligand [9]aneS3 and various polypyridyl ligands was carried out using [Ru(dmso)4Cl2] as a starting material. The first synthetic step involved the introduction of the thioether ligand and the isolation of the compound [Ru([9]aneS3) (dmso)Cl2]. The polypyridyl ligands were then exchanged...

The synthesis of a series of RuII complexes with the thioether ligand [12]aneS4 (1,4,7,10-tetrathiocyclododecane) and various polypyridyl ligands was carried out using [Ru(DMSO)4Cl2] (DMSO-= dimethylsulphoxide) as a starting material. The first synthetic step involved the introduction of the thioether ligand and the isolation of the compound [Ru([1...

Synthetic analogues of the microporous minerals umbite (AM-2) and penkvilksite, polytype 2O (AM-3), have been prepared. The facile syntheses of two other titanosilicates, AM-1 and AM-4, have also been reported. AM-1 and the previously reported, layered titanosilicate known as JDF-L1 have been shown to have the same structure. AM-4 is a new micropor...

It has been reported that treatment of wood surfaces with aqueous solutions of chromium trioxide imparts some beneficial properties like weather resistance and some degree of water repellency. The work presented here aims at finding alternative ways of fixing chromium in wood with the avoidance of the very acidic and strong oxidant conditions of ch...

The thermal decomposition of cork has been studied by Fourier transform infrared (FTIR) spectroscopy and 13C solid-state nuclear magnetic resonance (NMR) spectroscopy with cross-polarization and magic-angle spinning (CP-MAS), high-power 1H decoupling (HPDEC) and cross-polarization depolarization-polarization (CPDP). Waxes and other soluble componen...

The co-ordination geometry of boron in derivatives of a polyoxotungstate with the Keggin structure, K5[BW12O40]·11 H2O, has been studied by solid-state magic-angle-spinning NMR spectroscopy (in tandem with Fourier-transform infrared spectroscopy) which is shown to be a sensitive tool for probing the immediate environment of 11B in polyoxotungstates...

ZnO and ZnS powders were prepared from aqueous solutions of zinc salts in the presence of ethylenediamine or triethanolamine. The morphology of the powders was analysed by scanning electron microscopy and infrared spectroscopy. The effect of the experimental conditions upon the size and shape of the particles is described with a special emphasis on...

Standard samples of stream humic and fulvic acids have been studied by high-resolution 13C solid-state NMR. The spectra have been recorded at a high (9.4 T) magnetic field using 1H-13C cross-polarization (CP) and proton high-power decoupling (HPDEC) with fast (up to 15 kHz) magic-angle spinning (MAS). The widths of the spectral lines decrease with...

Similar anionic complexes are formed by the sulphur-containing amino acids cysteine and penicillamine with chromium(III). The compounds form stereospecifically with CrS2N2O2 chromophores, the sulphur atoms being trans to each other. The CrS bonds are unusually labile and the hydrolysis of these bonds has been studied by electronic and CD spectrosc...

Pink tris(S-alaninato)chromium(III) has been prepared and characterized. The compound is found to have sufficient solubility in water for the circular dichroism to be measured, moreover the circular dichroism in water is identical to that of the complex dissolved in DMSO or in the solid state (KBr disc). These results are used to comment on the wor...

Complex formation between Mo(VI) and (R)- cysteine, abbreviated H2cys, was studied in aqueous solutions (CMo⩽0.1 mol dm−3), using circular dichroism (CD) spectrophotometry and NMR spectrometry. Only one Mo(VI) complex is present in neutral or basic solutions, [MoO3(cys)]2− (I), in which cysteine is bonded to the metal as a terdentate ligand. Its fo...

The solvolyses by trifluoroethanoic (“trifluoroacetic” TFA) acid of several known and new thiocyanates have been studied using proton magnetic resonance. For the organic linkage isomers of RNCS (R = alkyl groups) isothiocyanates react (via N-alkyl monothiocarbamato trifluoroethanoates) to form alkylamines RNH2, whereas the thiocyanates RSCN yield t...

Resolved cis-[Rh(en)2(OH)2]+ or cis-[Rh(en)2(OH2)2]3+ were formed by base or acid hydrolysis, respectively, of resolved oxalato bisethylenediamine rhodium(III); acid dissociation constants, determined using circular dichroism, are given by pK1 = 5.02 and pK2 = 9.04, and these are compared with values from pH titration. Cis-[Rh(en)2(H2O)(OH)]2+ show...

The activities of the nicotine complexes of rhodium(III)-[RhCl3(nicH+)3](PF6)3 andtrans-[RhCl2(nic)4](PF6) (nicH+=monoprotonated S-nicotine, nic=unprotonated S-nicotine)—were studied onEscherichia coli B growing in a minimal glucose medium in both lag- and log-phases. [RhCl3(nicH+)3](PF6)3 at 50 ppm caused bacteriostasis, and at 100 ppm or more wa...

Isothiocyanates such as (I) are solvolyzed to give the corresponding amine (IV) via the intermediate (III).

Solution studies of H-autunite, H2(UO2)2(PO4)2, and its K+, Na+, Li+, Ca2+, Mg2+, Cu2+ and Ni2+ analogues, have been carried out and solution stability constants determined. These values are in excellent agreement with those recently reported by other workers at 298.2 K and ionic strength equal to zero. separate field study involving groundwaters c...

Ionen (I), die N-koordiniertes Nitrit enthalten, unterliegen in wäßriger Lösung einer Photoreaktion mit O3 unter Bildung der monomeren oder dimeren Titelverbindungen (II) und (III).

Complex formation between molybdate ions and R,R-(+)-tartaric acid has been studied in aqueous solution, and to a limited extent in DMSO, over a range of concentrations and pH at 298K, using1H and13C n.m.r. techniques. Only four main species are evident; two, which have Mo: L ratios of 11 and 12, are bondedvia a carboxylic oxygen atom and an adjace...

A number of studies of species formed in the tungsten(VI) oxide-R,R-(+)-tartaric acid-water system have been carried out(1–3). While various species have been proposed, it is generally accepted that three main ones predominate. Two have tungsten: (+)-tartaric acid [(+)-tartH4] ratios of 1∶1 and the third has the same ratio of 1∶2. This latter speci...

Bis(ethylenediamine)rhodium(III) compounds containing N-co-ordinated nitrite ion photoreact with molecular oxygen to give the monomeric superoxorhodium(III) ion, [Rh(en)2(OH2)(O2)]2+, and dimeric superoxo-bridged dirhodium(III,III) species. Irradiation of cis- and trans-bis(ethylenediamine)- dinitrorhodium(III) salts, both in the presence and the a...

The bridged dimeric MoVI complexes of citric acid M2[Mo2O5OH(H2O)(C6H5O7)] 0.5 H2O, M=K+, NH 4 + , have been synthesized. In the solid state they undergo an irreversible photochemical reaction to yield CO2, MoV species and acetone dicarboxylic acid. In aqueous solution the ligand decomposition proceeds further to yield acetone as the main product....

ESR-Spektren von cis- und trans- [Rh(O2)(en),Cl] , [ Rh(en),C1 ,(u-0,)]3+ und [ RhL4Cl 2(u-O,)]3 (L: 4-Methylpyridin) in einer gefroreren DMF-Lösung bei 77 K zeigen, daß das ungepaarte Elektron weitgehend an O2 lokalisiert ist, und daß die Komplexe nominal als Verbindungen mit einer RhHI-Og-Einheit beschrieben werden können.

The complexation of molybdenum(VI) by L-aspartate in dilute aqueous solutions, at pH 6, was studied using u.v. spectrophotometry,1H and13C n.m.r. spectroscopy. A single complex anion, [MoO3(C4H5NO4)]2-, is observed in solution. The conformation of the aspartate ion in the complex was determined and shown to be consistent with it acting as a terdent...

Electron spin resonance spectra of cis- and trans-[Rh(O2)(en)2Cl]+, [{Rh(en)2Cl}2(µ-O2)]3+, and [{Rh(4Me-py)4Cl}2(µ-O2)]3+(en = ethylenediamine, 4Me-py = 4-methylpyridine) ions in solution show that the unpaired electron is largely localized on the dioxygen and that the complexes may nominally be described as having the RhIII–O2– unit. A molecular-...

Solid samples (powders and crystals ) of optically active sodium chlorate, bromate, periodate trihydrate, uranylacetate, of benzil, and of nickel sulphate hexahydrate have been used in attempts to secure selective absorption or reaction with several racemic compounds, such as tris(pentane-2,4-dionato)cobalt(III) and α-lipoic acid. No genuine optica...

Monomeric superoxo-rhodium(III) species, relatively stable in water, have been synthesised by the action of light and dioxygen upon compounds containing the nitro-rhodium(III) function.

Transient species produced on photolysis of aqueous solutions of UO2+2 and some inorganic anions have been studied by flash photolysis. With I−, CNS− and Br− absorptions are observed which are assigned to the X??2 radical anions formed by one-electron photo-oxidation by uranyl followed by reaction with the corresponding anion. Both intra- and inter...