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Women's football experienced exponential growth after the FIFA Women's World Cup 2019. Determinants of the construction of the player's brand add value to understanding which image they want for themselves and their sport. This study aims to provide a multidimensional exploration of this process based on self-presentation, gender roles, and economy of visibility. Two studies were conducted, a content analysis of eight female national team footballers' Instagram posts (n= 278) and a survey of football fans (n= 430). The footballers presented themselves first as players and second as females. The results revealed that male agentic roles are part of the players' brand construction narrative, including female communal gender roles. The survey disclosed that elite footballers' perceived images were primarily congruent with how they presented their persona. Fans preferred the professional presentation as footballers. Fans' interest was related to agentic and communal roles, which players rarely addressed. Personal brand management by players and the collective construction of a global women's football brand is discussed.

AbstractThe decline of voter turnout in Portugal was confirmed in the legislative election of 2015. The unquestionable democratic value associated with the act of voting, leads to the discussion of this issue, and emphasizes the need for additional investigation. Particularly, it is crucial to identify the characteristics of citizens who vote, to better understand the phenomenon and think about solutions. This work identified the most significant sociodemographic variables in explaining voter turnout in continental Portugal and described the relationship between those variables and voter turnout, including the geographical variation existing across the municipalities. A Semiparametric Geographically Weighted Regression (SGWR) model enabled the investigation of local variations in turnout values, simultaneously considering that its relationship with some variables might vary over space. Results show that turnout is influenced by a set of sociodemographic variables. While some variables affect turnout differently over the country (percentage of family cores with children aged less than 15, and percentage of owner-occupied houses), others affect it uniformly (percentage of graduated residents, percentage of classic families, and distance to Lisbon or Oporto – the nearest). These results suggest the use of a semiparametric approach to better understand turnout and for further research on voting issues.

This work aims to synthesize the alloy Co62Nb32B6through a wet-route mechanical alloying using a planetary ball mill. A disc rotation per minute and a ball/powder weight ratio of 350 rpm and 20:1 were used, with a grinding time of 15 h, respectively. The characterization of the Co62Nb32B6alloy was performed by X-ray diffraction (XRD), examined by scanning electron microscope-energy-dispersive X-ray spectroscopy (SEM–EDS), thermoanalytical techniques (TGA/DTA), vibrating sample magnetometer (VSM), and confirmed by the BET method type IV isotherms with a hysteresis loop for mesoporous materials. The results indicated the evolution of the amorphous phase in the Co62Nb32B6composition through the mechanical alloying process and exhibited good soft magnetic properties with the addition of the B metalloid element and their excellent unique ferromagnetic properties. Through thermoanalytical analysis (TGA/DTA), it was shown that at higher temperatures, oxidation with a significant increase in mass gain of 19.69% at 865 °C, probably due to the contribution of B in the evolution stability thermal and magnetic in the amorphous phase, respectively. This suggests that the newly developed high-performance amorphous alloy Co62Nb32B6has great application potential.

Internal devaluation policies imposed in southern European countries since 2010 have weakened labour market institutions and intensified wage inequality and the falling wage share. The debate in the wake of the financial and economic crisis raised concerns about slow wage growth and persistent economic inequality. This article attempts to shed light on this debate, scrutinising the case of Portugal in the period 2010–2017. Mapping the broad developments at the national level, the article examines four sectors, looking in particular at the impact of minimum wages and collective bargaining on wage trends vis-à-vis wage inequality and wage share trajectories. We conclude that both minimum wage increases and the slight recovery of collective bargaining had a positive effect on wage outcomes and were important in reducing wage inequality. The extent of this reduction was limited, however, by uneven sectoral recovery dynamics and the persistent effects of precarious work, combined with critical liberalisation reforms.

Aim:To assess the effect of cashew nut flour on the hematological parameters of children living with HIV-AIDS. Method:A 32-week randomized, blind clinical trial conducted at a specialized outpatient clinic. Children aged 2–12 years were allocated to intervention groups (IGs) (n= 11) receiving 12 g/day of cashew nut flour and control groups (CGs) (n= 9) receiving 12 g/day of carboxymethyl cellulose. Parameters of erythrocytes, leukocytes, platelets, and lipid profiles were evaluated. Results:In the IG, the elevation and reduction of leukocyte and lipid profile biomarkers, respectively, were not statistically significant (p> 0.05). A clinically and statistically significant increase in mean corpuscular hemoglobin concentration was observed in the CG (p= 0.018), with a large effect size (Cohen's d = 0.9). There were no statistically significant changes in platelet counts among participants (p= 0.18). The effect size for white blood cell count, low-density lipoprotein cholesterol, very low-density lipoprotein, and triglycerides was moderate in the IG compared to the CG. Conclusion:Cashew nut flour supplementation may increase levels of leukocytes and lipid profile parameters in children living with HIV. Brazilian Clinical Trials Registry (REBEC): U1111.1276.6591.

This work synthesized and investigated the amorphous alloy Fe73Si22B5obtained by high-energy milling. The properties of the amorphous alloy Fe73Si22B5were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) with EDS, Fourier transform infrared spectrometry (FTIR), thermal analysis TGA/DTA, textural analysis by N2 (BET/BJH), and magnetic measurements (VSM). The results confirmed that the Fe73Si22B5alloy reached the desired amorphization degree and presented IV isotherms with a hysteresis loop for mesoporous materials. The TGA/DTA confirmed that Fe and Si ions are quickly oxidized in the environment with the mass slightly increased to 27.5%. The Fe73Si22B5exhibited soft magnetic properties with ferromagnetic characteristics. The FTIR spectra exhibit absorption peaks corresponding to the presence of (R)O–H, Fe–O, Si–O, O–Fe–O, and Si–O–Fe groups. This result suggests that the developed high-performance Fe73Si22B5amorphous alloy has great application potential in various research fields.

ABSTRACTUrban systems are not only major drivers of climate change but also the impact hotspots. In the context of the planet currently undergoing a process of greenhouse warming, and simultaneously predominantly urban based ever continuing population growth, our agglomerations became vulnerable to chain reactions triggered by climate related hazards. Hence, the reliable and cost-effective assessment of future impact is of high importance. While the climate community has invested significant effort to provide downscaling techniques yielding localized information on future climate extreme behaviours, these methods do not remain widely exploited in the process of urban planning. In this work, we discuss the underlying reasons and main challenges of the applicability of downscaling procedures in the real process of urban planning. This paper attempts to help bridge the gap between the communities of urban planners and climatology. In the beginning, we summarize the rationale for such cooperation, supporting the argument that the scale represents an important linkage between urbanistic and climate science in the process of designing an urban space. Secondly, we introduce the main families of downscaling techniques and their application on climate projections, also providing the references to profound studies in the field. Thirdly, special attention is given to previous works focused on the utilization of downscaled ensembles of climate simulations in urban agglomerations. Finally, we identify three major challenges of the wider utilization of climate projections and downscaling techniques, namely: (i) the scale mismatch between data needs and data availability, (ii) the terminology, and (iii) the IT bottleneck. The practical implications of these issues are discussed in the context of urban studies.

This work involved the development of alumina/hydroxyapatite (Al2O3/HAp) composites for use as bone graft material in maxillofacial reconstruction. The effect of introducing 20 and 30 wt% of hydroxyapatite into the alumina matrix was also investigated. The composites were produced from hydroxyapatite synthesized by the precipitation method, using commercial alumina as a matrix. Samples of the composite material were compacted under 260 MPa of isostatic pressure, followed by sintering at 1200°C/2h and characterization by X-ray diffraction (XRD), scanning electron microscopy (SEM), and diametral compression. The XRD results confirmed the presence of Al2O3 and Ca10(PO4)6(OH)2 – HAp crystalline phases in all composites. The addition of HAp to the alumina matrix inhibited alumina grain growth, reducing intergranular porosity and thus promoting greater densification and mechanical strength of the composites.

Biodiesel is a biodegradable fuel derived from renewable biomass, such as soybean and cottonseed oil, which may be obtained by different processes and requires a material to catalyze the obtaining reactions. The irons spinel comes overlapping as excellent materials to catalyze the biodiesel production reactions. Thus, the purpose of this work was the use of Ni0.5Zn0.5Fe2O4 nanoferrite as a catalyst in esterification reactions. The nanoferrite was synthesized by combustion in large scale, 200g/batch, where time and the temperature of the reactions were measured, and characterized by XRD and measuring its surface area. The biodiesel was obtained from methyl and ethyl esterification of acidified soybean oil and cottonseed, at a temperature of 160°C for 1 hour, molar ratio 1:15, 3% of catalyst and analyzed by chromatography. The nanoferrite has shown peaks of greater intensity corresponding to a majority crystal phase of the spinel and a surface area of ​​64.17m2/g. The conversion results for the soybean oil were 99.08% in methyl route and 98.38% in ethyl route. For cottonseed oil were 88.79% in methyl route and 78.65% in ethyl route.

This study aims to evaluate the hydrophobicity of vulcanized silicone rubber coatings at room temperature (RTV SR) with loads of alumina trihydrate (ATH) and nanosilica (NS) in the polymeric silicone rubber matrix, in order to obtain coatings ATH/NS/RTV SR to cover the surface of glass electrical insulators. The coatings were characterized by scanning electron microscopy (SEM), testing in salt spray chamber, loss test and recovery of hydrophobicity. These coatings showed varying sizes of agglomerates and heterogeneous distribution of particles within the matrix RTV SR. In the test in salt spray chamber smaller leakage current values was observed for the insulator coating with the ATH/NS loads. In the loss and recovery of the hydrophobicity test the best result was observed for insulating load RTV SR / 20: 1 (ATH: NS).

This paper presents a portable total reflection X-ray fluorescence system composed of a 15 W X-ray tube, with a gold anode, a waveguide constituted by two Perspex®parallel plates, a Si PIN detector and a quartz optical flat. The critical angle of the total reflection system was experimentally determined by measuring a zinc solution (100 mg/L). The accuracy of the system was checked using SRM 1577b Bovine Liver by NIST as standard reference material. We obtained the absolute detection limits of the following elements: P (450 ± 40 ng), S (200 ± 31 ng), K (30 ± 2.5 ng), Ca (19 ± 3.5 ng), Mn (4.1 ± 0.5 ng), Fe (3.6 ± 0.9 ng), Cu (3.3 ± 0.4 ng) and Zn (3.5 ± 0.3 ng). This paper shows that it is possible to produce total reflection X-ray fluorescence with very compact, efficient, low-cost and easy-to-handle instrumentation using a low-power X-ray tube and a Si PIN compact detector.

This paper aims to synthesize by combustion reaction and silanilized of the ZnAl1.9Eu0.1O4, with silane agent 3-aminopropyltrimethoxysilane. The characterization of materials before and after silanization was investigated. Nanoparticles ZnAl1.9Eu0.1O4 was obtained according to the theory of propellants and explosives using the synthesis combustion reaction. The samples were deagglomerated and passed through a sieve of 325 mesh and added to 3-aminopropyltrimethoxysilane, followed by heat shock treatment by ultrasonic and microwave. Subsequently centrifuged and dried at 150 ° C for 24 hours. The samples before and after the silane were characterized by X-ray diffraction, infrared spectroscopy and thermogravimetric analysis. The results indicate the formation of a major phase spinel normal ZnAl2O4, and the EuAlO3 peaks as secondary phase. The FTIR spectra for ZnAl1.9Eu0.1O4 have absorption bands below 1000 cm-1, and after silanization showed bands of C = O, axial strain - CN and Si-O bands, which proves the silanization. The thermogravimetric curves showed good thermal stability, with mass loss around 30%.

This paper proposes to investigate the influence of the type of container on the structure, morphology and measures magnetic nanoparticles of the Zn0.6Fe0.4O synthesized by combustion reaction, for use as diluted magnetic semiconductors (DMSs). For synthesis were used as containers stainless crucibles and porcelain. The heating was realized in a muffle furnace at 500 °C. During the reactions, were performed measurements of the maximum temperature and total time of combustion reaction. The synthesized samples were characterized by XRD, SEM and magnetic measurements. The maximum temperatures obtained were 478 and 456 °C and total reaction time of 285 and 195 s for the samples synthesized in the crucible of stainless steel and porcelain, respectively. In both containers were possible to obtain single phase material with average crystallite size of 26 to 37 nm, irregular agglomerates formed by, behavior ferrimagnetic whose, saturation magnetization values of 1.6 e 2.0 emu/g respectively.

The aim of this study is to evaluate the effect of temperature during the synthesis of alumina by combustion in a muffle furnace. The alumina was characterized by X-ray diffraction, particles size distribution and scanning electron microscopy. The results showed that the synthesis temperature of the alumina can affect the structure of the produced samples. The size distribution of the median particle diameter reached higher value for the alumina synthesized at 500°C with 16.07 μm, the range of the total distribution of particles is introduced to the large alumina synthesized 500 and 600°C and close synthesized when 700 and 800°C. The phase of the alumina was identified only after the synthesized sample at 800°C with crystallite size of 22.16 and 6.75 μm synthesized samples 800 and 900°C, respectively. With respect to morphology, increased synthesis temperature was not enough to significantly change.

The search of variations in the methodology for obtaining nanoferrites has attracted the interest of researchers in search of better results with regard to the structure and morphology of these materials. This study evaluates the effect of microwave power (50 and 70 W) in the structural and morphological characteristics of NiZn ferrite, using aniline as a fuel for combustion reaction. The aluminas were characterized by X-ray diffraction and scanning electron microscopy. The results showed that only the variation in microwave power is sufficient to change the structure of nanoferrites. The sample synthesized in power of 50 W was presented monophasic, illustrating the ferrite phase with crystallite size of 50.04 nm; and for 70 W, it was appeared, besides the ferrite phase, hematite and zinc oxide with a crystallite size of 17.07 nm. The morphology did not change significantly, the nanoferrites showed particles with similar geometry.

This study proposes to evaluate the influence of the variation of sintering temperature on microstructural characteristics and magnetic ferrite Ni0,5Zn0,5Fe2O4 sintered by microwave energy. The samples were sintered at 900, 1000, 1100 and 1200oC for exposure time of 10 minutes, with rate 50oC/minutes and characterized by density and porosity, X-ray diffraction, scanning electron microscopy and magnetic measurements. The results indicate that the values of density and apparent porosity were 4.2, 4.5, 4.4 and 4.5 g/cm3 and 3.4, 2.1, 2.2 and 2.4% for the sintering temperatures of 900, 1000, 1100 and 1200oC respectively. The formation of the ferrite phase Ni0,5Zn0,5Fe2O4 been identified for all conditions of sintering, with grain sizes of 52, 62, 71 and 58nm and saturation magnetization values of 63, 68, 69 and 27 emu/g to temperatures sintering 900, 1000, 1100 and 1200oC respectively.

This work involved a study of the reproducibility of the process of combustion synthesis to produce Ni-Zn ferrites. The structural, morphological and magnetic characteristics of the samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and magnetometry using an alternating gradient magnetometer (AGM). The XRD diffractograms of the samples indicated that they are monophasic, crystalline, with crystallite sizes ranging from 21 to 38 nm, and have a homogeneous morphology consisting of agglomerates of spherical particles. The samples behaved as soft magnetic materials, with magnetization levels ranging from 37 to 47 emug-1. The combustion synthesis was found to be efficient in producing Ni-Zn nanoferrites, yielding reproducible results.

The influence of particle size of the load in the structure and morphology of the composite is an important factor in their final properties. This study will evaluate the behavior of the load of nickel ferrite calcined at different temperatures (700, 900 and 1200 ° C) with the polyamide matrix 6. In the preparation the polymer matrix was previously been dried in a vacuum oven at 80 ° C/48hs for eliminating humidity, and then the load was incorporated in the form of powders calcined at three temperatures in the mass concentration of 50%. Thereafter, the mixture was compressed to obtain composites, which were characterized by XRD and SEM. The results show XRD characteristic peaks of nickel ferrite and polyamide 6, showing that the calcination caused an increase in crystallinity of the load. SEM results show that the calcination caused an increase in the size of the agglomerates of the load, favoring significant changes in the morphology of the composite.

Freshwater systems on the volcanic oceanic islands of Macaronesia and the macroinvertebrate communities that occupy them differ strongly from European mainland systems. This is a result of their geological origin, relatively small size, catchment morphology and distance from potential sources of colonization. The spatial and temporal distribution patterns of benthic macroinvertebrate assemblages were assessed over two seasons at 23 sites in 13 streams across the Azores Archipelago. ANOSIM results indicated significant spatiotemporal differences in macroinvertebrate assemblages between islands. Links between environmental factors distributed over different spatial scales and macroinvertebrate assemblages were assessed using DISTLM, a linear model for distance-based multivariate analysis and partial redundancy analysis (pRDA). Latitude and island age complex largely explained macroinvertebrate composition at the regional scale, while drivers of change at the local scale were land use, temperature, conductivity and nutrient levels. Flow variation was identified as the principal factor driving temporal change in macroinvertebrate community patterns. The results of this study provide support for current and future stream ecosystem research and baseline information for developing integrated freshwater management strategies for streams on the Azorean archipelago.

Freshwater systems on the volcanic oceanic islands of Macaronesia and the macroinvertebrate communities that occupy them differ strongly from European mainland systems. This is a result of their geological origin, relatively small size, catchment morphology and distance from potential sources of colonization. The spatial and temporal distribution patterns of benthic macroinvertebrate assemblages were assessed over two seasons at 23 sites in 13 streams across the Azores Archipelago. ANOSIM results indicated significant spatiotemporal differences in macroinvertebrate assemblages between islands. Links between environmental factors distributed over different spatial scales and macroinvertebrate assemblages were assessed using DISTLM, a linear model for distance-based multivariate analysis and partial redundancy analysis (pRDA). Latitude and island age complex largely explained macroinvertebrate composition at the regional scale, while drivers of change at the local scale were land use, temperature, conductivity and nutrient levels. Flow variation was identified as the principal factor driving temporal change in macroinvertebrate community patterns. The results of this study provide support for current and future stream ecosystem research and baseline information for developing integrated freshwater management strategies for streams on the Azorean archipelago.

This paper proposes to assess the efficiency of ZnAl2O4 obtained by combustion reaction on the process of esterification and transesterification of soybean oil to biodiesel production. In the synthesis it was used three heating conditions: spiral resistance, muffle furnace, and microwave oven. In order to investigate the influence of the heating source on the structure, morphology, and on the catalytic activity, the samples were characterized by XRD, FTIR, granulometric analysis, TGA, carbon content, TEM, and gas chromatography. The results showed that it was possible to obtain the ZnAl2O4 cubic phase with traces of ZnO. The ZnAl2O4 monophasic was just obtained by the synthesis carried out in the microwave oven and in the electrical resistance. All the samples showed a typical morphology of dense agglomerates and low carbon content. The samples also presented low catalytic activity in the esterification and transesterification process under the adopted conditions.

Through different field of application and productive growth that membrane technology has been presented in the last years, the aim of this work is to prepare and characterize anisotropic porous ceramic membrane. The membrane were done with alumina, prepared by combustion reaction in microwave oven from urea as combustible and after deposited on support based on a commercial alumina. The results showed that it was obtained α-alumina as unique phase with average agglomerate size of 10µ and surface area of 33 m2/g. The alumina morphology was constituted by pre-sintering particles with hard agglomerates and/or aggregates. In relation to the membranes, it was observed a longitudinal section without cracks and uncovers support surface, also it can be observed grain formation well distributed and a layer of alumina with approximately 35.25µm. In relation to the permeate flux, the membrane presented initially values relatively high that is decrease with the permeation time, due to adsorption of water in the internal surface of the pores of the membrane, experiencing a decrease in size.

This research was incorporated the hydroxyapatite in a mineral trioxide aggregate sealer, with the aim of studying this influence in the structure, morphology and radiopacity of the cement to obtain osteoconductive material. The samples were characterized by X ray diffraction (XRD), spectrometry fluorescence X ray (EDX), spectroscopy transform infrared Fourier (FTIR), scanning electron microscopy (SEM) and radiographic appearance. Through the results obtained by XRD for the new sealer observed the formation of phases HAp and MTA evidenced by the presence of phases: CaO, SiO2 and Bi2O verified also by EDX. Through FTIR was observed the presence of absorption bands related to links Ca-O, Si-O and Bi-O present in MTA and P-O present in HAp. The morphology visualized by SEM consists of irregular agglomerates with the formation of pre-sintered particles. The sample MTA/HAp3% presented radiopacity viable for their application as endodontic cement.

The aim of this work is to evaluate the esterification and transesterification activity of ZnAl2O4 catalysts obtained by different ways of heating during the combustion synthesis using glycine as fuel. Samples were prepared according to the propellants and explosives theory using a vitreous silica crucible as container, and as heating source, plate, muffle furnace and microwave oven. After synthesis, the samples were structural and morphologically characterized by: XRD, nitrogen adsorption and carbon content analysis, and employed in the esterification and transesterification reactions, the percentage of biodiesel formed (FAME) was determined by gas chromatography. The samples obtained on the plate, muffle furnace and microwave showed that even using different heating ways, led to the formation of ZnAl2O4 as majority phase, with crystallite sizes of 11, 15 and 10 nm, respectively. The samples present values of surface area ranging from 16 to 77 m2/g, particle size from 17 to 81 nm, and carbon content lower than 11%. The forms used for heating influenced the esterification and transesterification reactions, showing that there was a gap in the production of biodiesel, which is a promising indication that this material has potential to be used as catalysts on the biodiesel production.

This study aimed to assess the performance of the solid catalyst Ni0.4Cu0.1Zn0.5Fe2O4, synthesized by combustion reaction, over the methyl esterification reaction of the fatty acids present in cottonseed oil. The catalyst was characterized by XRD, FTIR pyridine absorption, Raman spectroscopy, and SEM. The reactions were conducted at 140 and 180°C with molar ratios of 1:3, 1:6 and 1:9, with 2% of catalyst and reaction time of 2 h. The XRD results showed that the single phase ferrite was obtained with surface area of 87 m2/g and with mesoporous characteristic. It was observed from the FTIR pyridine absorption only the presence of Lewis acid sites. The Raman spectra confirm the presence of the inverse spinel phase. The results indicated that at 180°C and molar ratio of 1:9, the conversion of free fatty acids was about 87%.

This paper aims to synthesize and characterize nanosized nickel and zinc ferrites (NiFe2O4 and ZnFe2O4) samples by a combustion reaction method, using glycine as fuel. The performance in HT-WGRS reaction the samples was investigated. The results showed that the combustion reaction was effective in the production of major phases of the spinel ferrite (crystallite sizes of 44 and 27 nm) and presence of the secondary phases, such as Ni and ZnO, with surface area 3 and 115 m2/g for NiFe2O4 and ZnFe2O4, respectively. HT-WGSR activity was achieved (80%) to NiFe2O4 ferrite in the temperature range of 300 - 500oC.

This aim of this work is to evaluate the influence of citric acid/metallic cation ratio of 3:1, 4:1 and 5:1 used in the TiO2 synthesis by Pechini method in the structure, morphology and photocatalytic activity of methyl red dye. The prepared samples were characterized by X-ray Diffraction (XRD) using Rietveld refinement method, textural analyses, and photocatalytic activity. The results obtained by XRD technique confirm the efficiency of the Pechini method in the preparation of TiO2 samples with nanosize particle. All samples present anatase phase and presence of rutile as secondary phase with content of 15.6, 10.5 and 18.3%. The isothermal adsorption showed that samples have mesopores characteristics and morphology with irregular shape agglomerates. The sample 4:1 presented better photocatalytic performance discoloring 70% of dye in 24h, indicating that the presence of 10.5% of rutile phase jointly with anatase phase improve the photocatalytic activity.

Research in Mn-Zn ferrites have been growing in recent years, mainly because of the properties in high frequency application such as high saturation magnetization, low core losses, which are sensitive to the structure, processing conditions, such as sintering temperature, time and atmosphere. This study aims to evaluate the microstructure and magnetic characteristics Mn0.65Zn0.35Fe2O4 ferrite sintered in N2 atmosphere and to microwave energy at 1200oC/2h. The samples were compacted by uniaxial pressing at 200 MPa and sintered in a microwave oven with a heating rate of 50oC/min and sintering time of 30 min. For samples sintered in N2 atmosphere was used heating rate of 5oC/min with sintering time of 2 hours. The samples were characterized by apparent and bulk density, XRD, SEM and magnetic measurements. The results indicate the formation single phase of Mn-Zn ferrite for sample sintering in N2 atmosphere, and to sintering by microwave oven observed the phase ferrite Mn-Zn with trace of secondary phase hematite. The density and saturation magnetization were 3.14 and 3.12 g/cm3, 5 and 83 emug-1 for the samples sintered by microwave energy and N2 atmosphere respectively.

This work proposes to study the influence of dilution on the synthesis of ferrites Mn0.65Zn0.35Fe2O4 using glycine. It was used the reactants/H2O proportions of 1:0; 1:3.5; 1:7; 1:10, and 1:14 (100 mL of H2O). During the synthesis were measured the time and temperature of combustion. The samples were characterized by X-ray diffraction and X-ray fluorescence. The dilution in the samples increased with the increasing of the reaction time and flame temperature. For samples synthesized with 1:0, 1:3.5; and 1:7 ratio were observed traces of hematite, and to the remaining samples only the single phase of the Mn0.65Zn0.35Fe2O4 spinel. The crystallite sizes ranged from 32 to 42 nm.

The aim of this work is to evaluate the catalytic performance in steam reforming of methane of the NiAl2O4 catalysts prepared by combustion reaction with different urea levels. The catalysts were prepared with urea in the stoichiometric proportion, and with excess of 10% and 20%. The samples were characterized by DRX, textural analysis by nitrogen adsorption, SEM, TPR, and then, catalytically evaluated in the methane reforming reaction. The results showed the presence of NiAl2O4 and traces of NiO for all the samples. The increase of the urea content caused an increase in the particle size and a reduction in the surface area, from 171 to 35 m2/g. All the samples presented irregular morphology. The TPR curves showed peaks of reduction of the NiO species, and reduction of nickel present in the NiAl2O4. Regarding the conversion of methane to synthesis gas, it was observed that the increase of the urea content allowed obtaining higher conversion. However, it was also observed a rapid deactivation of these catalysts due to high coke deposition on the active phases surfaces.

This work shows the influence of the fuels aniline, carbohydrazide and glycine on structural and morphological characteristics of ZnAl2O4 synthesized by combustion reaction. Samples were prepared according to the propellants and explosives theory using a vitreous silica crucible and a muffle furnace as heating source. During the synthesis was measured the time and temperature of the reaction. After The samples were structurally and morphologically characterized by the following techniques: XRD, nitrogen adsorption / desorption (BET / BJH), and SEM. The higher temperature was achieved by the synthesis using aniline, whose value was of 876°C. XRD results showed that all the samples presented the ZnAl2O4 spinel as majority phase and, ZnO and Al2O3 as segregated phases. The samples also showed low surface area, varying of 23.6 to 28.7 m2/g, and particle size of 45 to 55 nm, besides mesoporous characteristic and irregular agglomerates formation.

This paper reports the preparation of ferrite Ni0,5Zn0,5Fe2O4 by combustion reaction in a microwave oven, and its structural, morphological and magnetic characterization. The influence of microwave power and the fuel type was investigated. The samples were characterized by: XRD, BET, SEM and AGM. The results showed the formation of phase ferrite Ni0, 5Zn0,5Fe2O4 in all conditions evaluated. The presence of secondary phase hematite and nickel were observed only in samples with glycine. The microwave oven power and the fuel type altered the structure, morphology and magnetic behavior of the samples. In general, the samples synthesized with urea are promising for applications in catalysis, ferrofluids, magnetic sensors and the samples synthesized with glycine are promising for use as absorber electromagnetic radiation, due to the large particle size and good magnetic characteristics observed.

This paper proposes to assess the sintering of Ni-Zn ferrites synthesized by combustion reaction in advance to procure materials for applications as soft magnetic devices. The samples used for sintering have different morphological characteristics and were previously synthesized by microwave energy. The samples were uniaxially pressed and sintered in a microwave oven at 1200oC/2h with a heating rate of 5oC/min, and characterized by XRD, SEM and magnetic measurements. The results show that for all samples have the formation of Ni-Zn phase and traces hematite as secondary phase. The resulting microstructure after sintering was different and was influenced by previous morphological characteristics of the synthesized samples. As for the magnetic parameters, all samples were characteristic of soft magnetic material with saturation magnetization between 57 and 62 emu.g-1, indicating are promising materials for the fabrication of soft magnetic devices.