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Highly electroactive N–Fe hydrothermal carbons and carbon nanotubes for the oxygen reduction reaction

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Journal of Energy Chemistry 2020年第11期29卷 260-270页

作者： R.G.Morais N.Rey-Raap J.L.Figueiredo M.F.R.Pereira Associate Laboratory LSRE-LCM Departamento de Engenharia QuimicaFaculdade de EngenhariaUniversidade do PortoR.Dr.Roberto Frias s/n4200-465PortoPortugal

Glucose-derived carbons were prepared by hydrothermal carbonization of glucose followed by carbonization or activation to obtain carbon materials with different microporosities. These microporous carbons and carbon nanotubes(CNTs) were functionalized with melamine and/or iron(Ⅱ) phthalocyanine(FePc)following three different methodologies:(i) Functionalization with melamine via thermal treatment,(ii)incorporation of the lowest amount of FePc reported in the literature via incipient wetness impregnation followed by thermal treatment and(iii) functionalization with melamine followed by Fe Pc *** chemical and textural characterization of the prepared materials and their electrochemical assessment allowed to understand the role of microporosity in the incorporation of FePc and its effect on the oxygen reduction reaction(ORR). It was observed that FePc was preferentially incorporated inside the porous structure, especially in samples with more developed microporosity. However, functionalization with melamine modified the textural properties and the surface chemistry, favoring the incorporation of FePc on the surface. Regarding the electrochemical performance, the presence of FePc greatly enhanced the electroactivity of the microporous catalysts. An onset potential of 0.88 V and a four-electron pathway were obtained for glucose-derived carbons, whereas the limiting current densities and kinetic current densities rose by 126% and 222%, respectively, in comparison to the base sample. Notwithstanding, the highest electrochemical activity was observed for the sample prepared with CNTs, due to the synergy between the active metal centers and their highly graphitic carbon structure. The electrochemical parameters of CNTFeP csurpass the commercial Pt/C. The half-wave potential is 40 mV higher, the limiting current density increases by 17%, and a negligible production of by-products(< 1%) was observed.

关键词： Iron(Ⅱ)phthalocyanine Hydrothermal carbons Carbon nanotubes Oxygen reduction reaction Electrocatalysis

An advanced anaerobic biofilter with effluent recirculation for phenol removal and methane production in treatment of coal gasification wastewater

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Journal of Environmental Sciences 2016年第9期28卷 23-33页

作者： Yajie Li Salma Tabassum Zhenjia Zhang School of Environmental Science and Engineering Shanghai Jiao Tong University LCM-Laboratory of Catalysis and Materials Associate Laboratory LSRE-LCMDepartamento de Engenharia QuímicaFaculdade de EngenhariaUniversidade do Porto

An advanced anaerobic biofilter（AF） was introduced for the treatment of coal gasification wastewater（CGW）,and effluent recirculation was adopted to enhance phenol removal and methane *** results indicated that AF was reliable in treating diluted CGW,while its efficiency and stability were seriously reduced when directly treating raw ***,its performance could be greatly enhanced by effluent *** optimal effluent recirculation of 0.5 to the influent,concentrations of chemical oxygen demand（COD） and total phenol in the effluent could reach as low as 234.0 and 14.2 mg/L,***,the rate of methane production reached 169.0 m L CH_4/L/*** CGW seemed to restrain the growth of anaerobic microorganisms,especially methanogens,the inhibition was temporary and reversible,and anaerobic bacteria presented strong *** activities of methanogens cultivated in CGW could quickly recover on feeding with glucose wastewater（GW）.However,the adaptability of anaerobic bacteria to the CGW was very poor and the activity of methanogens could not be improved by long-term *** analysis using the Haldane model,it was further confirmed that high effluent recirculation could result in high activity for hydrolytic bacteria and substrate affinity for toxic matters,but only suitable effluent recirculation could result in high methanogenic activity.

关键词： Coal gasification wastewater Effluent recirculation Methane production Anaerobic biofilters

Quasinormal Modes of the Planar Black Holes of a Particular Lovelock Theory

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Communications in Theoretical Physics 2018年第12期69卷 689-694页

作者： Dan Wen Kai Lin Wei-Liang Qian faculdade de engenharia de Guaratingueta Universidade Estadual Paulista Hubei Subsurface Multi-Scale Imaging Key Laboratory Institute of Geophysics and GeoinformaticsChina University of Geosciences Escola de engenharia de Lorena Universidade de Sao Paulo

In this work, we study the scalar quasinormal modes of a planar black hole metric in asymptotic anti-de Sitter spacetime derived from a particular Lovelock theory. The quasinormal frequencies are evaluated by adopting the Horowitz-Hubeny method as well as a matrix formalism. Also, the temporal evolution of small perturbations is studied by using finite difference method. The roles of the dimension of the spacetime, the parameter of the metric k, as well as the temperature of the background black hole, are discussed. It is observed that the particular form of the metric leads to quasinormal frequencies whose real parts are numerically insignificant. The black hole metric is found to be stable against small scalar perturbations.

关键词： quasinormal modes Lovelock theory Horowitz-Hubeny method matrix method

Evaluation of bearing, gears and gearboxes performance with different wind turbine gear oils

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Friction 2015年第4期3卷 275-286页

作者： Ramiro Carneiro MARTINS Carlos M.C.G.FERNANdeS Jorge H.O.SEABRA INEGI Universidade do PortoPortoPortugal faculdade de engenharia Universidade do PortoPortoPortugal

The oil viscosity specification for wind turbine gear oils is ISO VG 320,although there are quite different viscosity indexes oils for that viscosity *** work evaluates the behaviour of different base oil formulations,since polyalphaolefin(PAO),mineral,ester and polyalkeleneglycol(PAG)that withstand quite different viscosity *** oils evaluation was done in rolling bearing tests and gear *** behaviour was compared for operating conditions in the range observable in a wind turbine *** experimental results showed considerable differences between the different oils and it was observed that depending on the contact type the relative behaviour of the lubricants would change,i.e.,the best lubricant for the rolling bearing would not imply the best result on the gear *** gear geometry is also very important toward the transmission efficiency,once using a low loss gear concept a decrease of up to 25%in torque loss could be *** models were implemented with the purpose of performing a better simulation of the mechanical system and also to obtain the friction coefficient promoted by the tested oils.

关键词： gears rolling bearings friction coefficient lubricants efficiency

Assessing the estrogenic potency in a Portuguese wastewater treatment plant using an integrated approach

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Journal of Environmental Sciences 2010年第10期22卷 1613-1622页

作者： Mário S.Diniz Rita Maurício Mira Petrovic Maria J.López de Alda Leonor Amaral Isabel Peres Damiá Barceló Fernando Santana Universidade Nova de Lisboa Faculdade de Ciencias e TecnologiaREQUIMTEDep.de Quimica Universidade Nova de Lisboa Faculdade de Ciencias e TecnologiaDep.de Ciencias e Engenharia do Ambiente department of Environmental Chemistry-IIQAB-CSIC c/Jordi Girona

The estrogenic potency of a wastewater treatment plant （WWTP） was evaluated using chemical and biological analyses, which showed that after the station treatment processes some of the selected endocrine disruptor compounds （EDCs） were still present in the treated effluent （e.g., bisphenol A, alkylphenols, estrone）. Thus, the most common endocrine EDCs were identified and quantified and the overall estrogenicity of the treated effluent assessed by integrating the results. Male goldfish （Carassius auratus） were used as biological indicators in a 28-day experiment. Vitellogenin （Vtg）, gonadosomatic and hepatosomatic indices, steroids （17β-estradiol and 11-ketotestosterone） and histopathology were biomarkers used in fish to evaluate WWTP treated effluent estrogenicity, in combination with instrumental analyses. The results showed a significant increase （P 〈 0.01） in plasma and liver Vtg, which were significantly correlated （r = 0.66; P 〈 0.01）. The gonadosmatic index was significantly （P 〈 0.01） reduced in exposed fish. The steroid analyses revealed significant elevations in 17β-estradiol and depressed 11-ketotestosterone concentrations. The histological examinations show changes in exposed fish gonads, such as regressed testes and in some cases （43% to 75%） the development of ovo-testis in fish exposed to 50% and 100% treated effluent.

关键词： Carassius auratus endocrine disruptors vitellogenin steroids intersex

Effect of pier shape and pier alignment on the equilibrium scour depth at single piers

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International Journal of Sediment Research 2016年第3期31卷 244-250页

作者： Cristina Fael Rui Lana António Cardoso faculdade de engenharia Universidade da Beira InteriorEdificio Ⅱ das EngenhariasCalcada Fonte da Lameiro Instituto Superior de engenharia/Universidade do Algarve Instituto Superior Tecnico Universidade de Lisboa

The equilibrium scour depth at uniform single bridge piers depends on a large number of variables,including the pier horizontal cross-section shape and its alignment angle towards the flow *** influence of these variables has been studied by only a few researchers,mostly,on the basis of tests that were far from approaching *** experimental study aims at revisiting the influence of piers’ shape and alignment on local scouring for length-width ratios smaller than or equal to 4,by increasing the experimental *** five long-duration laboratory tests were run under steady,clear-water flow,close to the threshold for initiation of sediment *** pier shapes were considered:circular,rectangular square-nosed,rectangular round-nosed,oblong,and zero-spacing(packed) pile-groups;the tested skew-angles were 0°,30°,45°,60°,and 90°.It was concluded that i) the shape factor can be taken as 1.0,for rectangular round-nosed and oblong cross-section piers,and as 1.2,for rectangular squarenosed and packed pile-group cross-section piers,ii) the shape factor does not vary significantly with the duration of tests,this way confirming the robustness of the shape factors reported to date,iii) the effect of shape is present at skewed piers although the associated coefficients remain in the narrow range of1.0-1.2,and iv) for length-width ratios smaller than 4,the shape factor is of the same order of magnitude as the skew angle factor and should not be neglected.

关键词： Scour Pier shape Pier alignment

Species-specific biomass allometric models and expansion factors for indigenous and planted forests of the Mozambique highlands

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Journal of Forestry Research 2021年第3期32卷 1047-1065页

作者： Tarquinio Mateus Magalhaes Victoria Norberto Cossa Benard Soares Guedes Amélia Saraiva Monguela Fanheiro departamento de engenharia Florestal Faculdade de Agronomia e Engenharia FlorestalUniversidade Eduardo MondlaneCampus UniversitárioEdifício no.1257MaputoRepública de Mocambique departamento de Sociologia Rural Escola Superior de Desenvolvimento RuralUniversidade Eduardo MondlaneVilankuloRepública de Mocambique

Secondary Miombo woodlands and forest plantations occupy increasing areas in Mozambique,the former due to anthropogenic ***,mainly species of Eucalyptus and Pinus,are being established on sites previously covered by secondary Miombo *** affects the evolution,cycle and spatiotemporal patterns of carbon(C)storage and stocks in forest *** estimation of C storage,which is indispensable for formulating climate change policies on sequestrating CO_(2),requires tools such as biomass models and biomass conversion and expansion factors(BCEF).In Mozambique,these tools are needed for both indigenous forests and *** objective of this study is to fit species-specific allometric biomass models and BCEF for exotic and indigenous tree *** incorporate efficient inter-species variability,biomass equations were fitted using nonlinear mixed-effects *** tree component biomass models had good predictability;however,better predictive accuracy and ability was observed for the 2-predictors biomass model with tree height as a second *** majority of the variability in BCEF was explained by the variation in tree *** species had larger crown biomass per unit of stem diameter and stored larger amounts of biomass per stem ***,due to relatively rapid growth,larger stem diameters,heights,and stand density,the plantations stored more biomass per tree and per unit area.

关键词： Biomass allometry Biomass partitioning Miombo Exotic forest plantations Brachystegia spiciformis Julbernardia globifl ora Eucalyptus Pinus

O_(3) based advanced oxidation for ibuprofen degradation

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Chinese Journal of Chemical Engineering 2022年第2期35卷 277-284页

作者： Vitória M.Almeida Carla A.Orge M.Fernando R.Pereira O.SaloméG.P.Soares Laboratory of Separation and Reaction Engineering-Laboratory of Catalysis and Materials (LSRE-LCM)Faculdade de Engenharia da Universidade do PortoRua Dr.Roberto Frias4200-465 PortoPortugal

The degradation of the anti-inflammatory ibuprofen(IBP)was evaluated by several advanced oxidation *** was treated by single ozonation and oxidation with hydrogen peroxide(H_(2)O_(2)),as well as a combination of these *** order to improve the efficiency,the presence of catalysts such as original carbon nanotubes,labelled as CNT,and iron oxide supported on carbon nanotubes,named as Fe/CNT sample,was *** evolution of IBP degradation,mineralization and toxicity of the solutions was *** formation of intermediates was also *** the non-catalytic processes,IBP was faster removed by single ozonation,whereas no significant total organic carbon(TOC)removal was *** with H_(2)O_(2) did not present satisfactory *** ozone and H_(2)O_(2) were combined,a higher mineralization was attained(70%after 180 min of reaction).On the other hand,in the catalytic processes,this combined process allowed the fastest IBP *** terms of mineralization degree,the presence of Fe/CNT increases the removal rate in the first hour of reaction,achieving a TOC removal of 85%.Four compounds were detected as *** treated solutions presented lower toxicity than the initial solution,suggesting that the released intermediates during applied processes are less toxic.

关键词： Advanced oxidation processes Catalysts Emerging pollutants Ibuprofen

Growth of Variable Aspect Ratio ZnO Nanorods by Solochemical Processing

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Journal of Materials Science & Technology 2015年第1期31卷 10-15页

作者： Marivone Gusatti Daniel A.R.Souza Nivaldo C.Kuhnen Humberto G.Riella departamento de engenharia Química e engenharia de Alimentos Programa de Pós-Graduacao em Engenharia Química LABMAC Universidade Federal de Santa Catarina (UFSC) Campus UniversitárioCP 476 Florianópolis Santa Catarina 88040-900 Brazil

In this work,variable aspect ratio（length divided by diameter） zinc oxide nanorods were synthesized through a simple solochemical method by reacting a Zn2+precursor with sodium hydroxide at low reaction *** analysis of the X-ray diffraction data indicated that the samples had hexagonal wurtzite structure and nanometric size *** transmission electron microscopy（TEM） images of the products prepared at60 and 80 ℃ exhibited rod-like architecture,showing that the reaction temperature did not affect the ZnO *** average aspect ratio of the ZnO nanorods decreased from 3.4 to 2.4 when the reaction temperature was raised from 60 to 80 ℃.The samples presented a blue shift in the excitonic absorption compared to ZnO bulk that increased alongside with reaction *** addition,this research investigated the results obtained by varying the concentration of zinc chloride *** the same temperature,it could be verified that when the zinc concentration was increased,the diameter of the ZnO nanorods also slightly increased,and much shorter nanorods were achieved,especially in the reactions performed at 50 and 70 ℃.Finally,the growth mechanism of the ZnO nanostructures was proposed based on the results obtained by changing the zinc precursor concentration and reaction temperature.

关键词： Chemical synthesis ZnO nanorods Growth mechanism