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Addressing soil protection concerns in forest ecosystem management under climate change

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Forest Ecosystems 2020年第3期7卷 432-442页

作者： ana Raquel Rodrigues Brigite Botequim catarina tavares Patrícia Pécurto JoséGBorges Forest Research centre School of AgricultureLisbon UniversityTapada da Ajuda1349-017LisbonPortugal

Background: climate change may strongly influence soil erosion risk, namely through variations in the precipitation pattern. Forests may contribute to mitigate the impacts of climate change on soil erosion and forest managers are thus challenged by the need to define strategies that may protect the soil while addressing the demand for other ecosystem services. Our emphasis is on the development of an approach to assess the impact of silvicultural practices and forest management models on soil erosion risks under climate change. Specifically, we consider the annual variation of the cover-management factor(c) in the Revised Universal Soil Loss Equation over a range of alternative forest management models to estimate the corresponding annual soil losses, under both current and changing climate conditions. We report and discuss results of an application of this approach to a forest area in Northwestern Portugal where erosion control is the most relevant water-related ecosystem ***: Local climate change scenarios will contribute to water erosion processes, mostly by rainfall erosivity *** forest management models provide varying levels of soil protection by trees, resulting in distinct soil loss ***: Results confirm the suitability of the proposed approach to address soil erosion concerns in forest management planning. This approach may help foresters assess management models and the corresponding silvicultural practices according to the water-related services they provide.

关键词： c-factor Erosivity Ecosystem services Forest management Revised universal soil loss equation(RUSLE)

Hydrocarbons in particulate samples from wildfire events in central Portugal in summer 2010

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Journal of Environmental Sciences 2017年第3期29卷 122-131页

作者： ana Vicente ana calvo ana P.Fernandes Teresa Nunes cristina Monteiro casimiro Pio célia Alves centre for Environmental and Marine Studies (cESAM) Department of EnvironmentUniversity of Aveiro Department of Physics IMARENABUniversity of León

In summer 2010, twenty eight （14 PM=2.5 samples plus 14 samples PM2.5-10） smoke samples were collected during wildfires that occurred in central Portugal. A portable high-volume sampler was used to perform the sampling, on quartz fibre filters of coarse （PM=2.5-10） and fine （PM2.5） smoke samples. The carbonaceous content （elemental and organic carbon） of particulate matter was analysed by a thermal-optical technique. Subsequently, the particulate samples were solvent extracted and fractionated by vacuum flash chromatog- raphy into three different classes of organic compounds （aliphatics, polycyclic aromatic hydrocarbons （PAHs） and carbonyl compounds）. The organic speciation was performed by gas chromatography-mass spectrometry （Gc-MS）. Emissions were dominated by the fine particles, which represented around 92% of the PM10. A clear predominance of carbonaceous constituents was observed, with organic to elemental carbon （Oc/Ec） ratios ranging between 1.69 and 245 in both size fractions. The isoprenoid ketone 6,10,14-trimethyl-2-pentadecanone, a tracer for secondary organic aerosol formation, was one of the dominant constituents in both fine and coarse particles. Retene was the most abundant compound in all samples. Good correlations were obtained between Oc and both aliphatic and PAH compounds. Pyrogenic processes, thermal release of biogenic com- pounds and secondary processing accounted for 97% of the apportioned PM2.5 levels.

关键词： WildfiresOrganic carbonOrganic compoundsBiomarkersParticulate matterPortugal

Thermal properties and high-temperature ablation of high-entropy (Ti_(0.25)V_(0.25)Zr_(0.25)Hf_(0.25))B_(2) coating on graphite substrate

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Journal of Advanced ceramics 2024年第8期13卷 1268-1281页

作者： ana c.Feltrin Daniel Hedman Farid Akhtar Division of Materials Science Lulea University of TechnologyLulea 97187Sweden center for Multidimensional carbon Materials(cMcM) Institute for Basic Science(IBS)Ulsan 44919Republic of Korea

An entropy-stabilized multicomponent ultrahigh-temperature ceramic(UHTc)coating,(Ti_(0.25)V_(0.25)Zr_(0.25)Hf_(0.25))B_(2),on a graphite substrate was in-situ sintered by spark plasma sintering(SPs)from constituent transition metal diboride ***(Ti_(0.25)V_(0.25)Zr_(0.25)Hf_(0.25))B_(2) coating had a hardness of 31.2±2.1 GPa and resisted 36.9 GPa of stress before delamination,as observed at the *** temperature-dependent thermal properties of the multicomponent diboride(Ti_(0.25)V_(0.25)Zr_(0.25)Hf_(0.25))B_(2) were obtained by molecular dynamics(MD)simulations driven by a machine learning force field(MLFF)trained on density functional theory(DFT)*** thermal conductivity,density,heat capacity,and coefficient of thermal expansion obtained by the MD simulations were used in time-dependent thermal stress finite element model(FEM)*** low thermal conductivity(component diboride coupled with its similar coefficient of thermal expansion to that of graphite indicated that stresses of less than 10 GPa were generated at the interface at high temperatures,and therefore,the coating was mechanically resistant to the thermal stress induced during *** experiments at 220℃ showed that the multicomponent diboride coating was resistant to thermal stresses with no visible cracking or *** ablation mechanisms were mechanical denudation and evaporation of B_(2)O_(5) and light V-Ti oxides,which caused a decrease in the mass and thickness of the coating and resulted in mass and linear ablation rates of-0.51 mg·s^(-1) and -1.38μm·s^(-1),respectively,after 60 *** findings demonstrated the thermal and mechanical stability of multicomponent entropy-stabilized diborides as coatings for carbon materials in engineering components under extreme environments.

关键词： entropy-stabilized diborides ultrahigh temperature ceramics molecular dynamics(MD)simulations density functional theory(DFT) ablation properties

Adsorption Behavior of Reducing End-Modified cellulose Nanocrystals:A Kinetic Study Using Quartz crystal Microbalance

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Journal of Renewable Materials 2020年第1期8卷 29-43页

作者： Maud chemin céline Moreau Bernard cathala ana Villares INRAE UR BIAF-44316NantesFrance

In this work,we studied the adsorption of modified cellulose nanocrystals onto solid surfaces by quartz crystal microbalance with dissipation monitoring(QcM-D).cellulose nanocrystals obtained from tunicate(cNc)were modified at reducing end by amidation *** different functionalities were investigated:a polyamine dendrimer(cNc-NH_(2)),which interacts with gold surface by the amine groups;and a biotin moiety(cNc-Biot),which has a strong affinity for the protein streptavidin(SAV).QcM-D results revealed different adsorption behaviors between modified and unmodified ***,unmodified cNcs covered almost all the surface forming a rigid and flat layer whereas reducing end modified cNcs remained rather upright forming a hydrated and viscoelastic layer with lower surface *** analysis of adsorption kinetics allowed the calculation of an apparent collision rate factor,which resulted 10-fold higher for unmodified cNcs compared to reducing end modified cNcs,therefore,demonstrating the different adsorption behavior.

关键词： cellulose nanocrystals amidation reducing-end modification Voight model collision rate efficiency factor rate constant

The road to sustainable use and waste management of plastics in Portugal

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Frontiers of Environmental Science & Engineering 2022年第1期16卷 91-106页

作者： Joana c.Prata ana LPatrício Silva Armando cDuarte Teresa Rocha-Santos centre for Environmental and Marine Studies(cESAM)&Department of chemistry University of Aveiro3810-193 AveiroPortugal centre for Environmental and Marine Studies(cESAM)&Department of Biology University of Aveiro3810-193 AveiroPortugal

As a European Union(EU)member,Portugal must comply with reductions in plastic *** Portugal,the 330 items/100 m of beach litter,comprising up to 3.9 million pieces and of which 88%is plastic,is higher than the EU median(149 items/100 m)and must be reduced to 20 items/100 m(94%).Integrative measures are needed to reduce littering and improve plastics’use and disposal under the circular *** this 414 kt of plastic packaging waste,163 kt were declared plastic packaging,140 kt subjected to recycling,and 94 kt to energy *** current recycling rate of plastic packaging(34%)should be improved to reach EU recycling averages(42%)and goals and to provide widespread benefits,considering revenues of 167€/*** a net importer of waste,Portugal could benefit from the valorization of imported *** increased recycling,pyrolysis and gasification could provide short-term alternatives for producing value-added substances from plastic waste,such as hydrogen,consistent with the National Plan of Hydrogen and improving ongoing regulations on single-use *** manuscript provides an integrative view of plastics in Portugal,from use to disposal,providing specific recommendations under the circular economy.

关键词： Single-use plastics Plastic packaging Plastic waste Waste management Waste shipment Lightweight plastic bags

Tailoring the partitioning of proteins using ionic liquids as adjuvants in polymer-polymer aqueous biphasic systems

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Green chemical Engineering 2022年第4期3卷 328-337页

作者： Flavia F.Magalhaes Matheus M.Pereira Rita de cassia Superbi de Sousa ana P.M.tavares Joao A.P.coutinho Mara G.Freire cIcEcO-Aveiro Institute of Materials Department of ChemistryUniversity of AveiroAveiro3810-193Portugal Separation Process Laboratory(LPS) Department of Food TechnologyFederal University of Viçosa(UFV)P.H.Rolfs Av.s/n36570-000 ViçosaMGBrazil

Aqueous biphasic systems(ABS)are promising for proteins purification;however,when dealing with samples comprising several proteins,the selectivity towards a target protein is difficult to *** this work,the addition of ionic liquids(ILs)as adjuvants(5 wt%and 10 wt%)in ABS composed of polyethylene glycol(PEG)and dextran was investigated to tailor proteins partitioning between the coexisting *** liquid-liquid phase diagrams were determined at 298 K,followed by partition studies of three proteins(bovine serum albumin(BSA),immunoglobulin G(IgG),and cytochrome c(cyt c)).Partition coefficients of IgG and BSA indicate the preference of both proteins to the dextran-rich phase,whereas cyt c has no preferential partitioning between the *** addition of chloride-based ILs as adjuvants allows to increase or decrease the partition coefficients,thus tailoring the proteins partitioning between the *** partitioning essentially depends on the IL content in each phase,whereas cyt c and IgG partitioning is ruled by the ILs chemical structure and established *** docking was carried out to address the ILs effect on the proteins partitioning,supporting experimental observations,while identifying the specific interactions *** partition of each protein in polymer-salt ABS with ILs as adjuvants was determined,demonstrating the higher tailoring ability of polymer-polymer ABS when adding ***,the partition of each protein in presence of the remaining ones was determined,as well as the selectivity of the studied systems to separate each pair of proteins,paving the way for their use in liquidliquid chromatography.

关键词： Aqueous biphasic systems Polymer-polymer systems Protein partition Ionic liquids Adjuvants

On conditionally Positive Definite Dot Product Kernels

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Acta Mathematica Sinica,English Series 2008年第7期24卷 1127-1138页

作者： V.A.MENEGATTO c.P.OLIVEIRA ana P.PERON Departamento de Matemática ICMC-USP- Sāo CarlosCaixa Postal 66813560-970 Sāo Carlos SPBrasil Universidade Federal de Itajubá ICE-DMCCaixa Postal 5037500-903 ItajubáMGBrasil

Let m and n be fixed, positive integers and P a space composed of real polynomials in m variables. The authors study functions f ： R →R which map Gram matrices, based upon n points of R^m, into matrices, which are nonnegative definite with respect to P Among other things, the authors discuss continuity, differentiability, convexity, and convexity in the sense of Jensen, of such functions

关键词： conditionally positive definite kernels dot product kernels Gram matrices convexity convexity in the sense of Jensen

Evaluation of Biodegradation in Aqueous Medium of Poly(Hydroxybutyrate-co-Hydroxyvalerate)/carbon Nanotubes Films in Respirometric System

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Journal of Renewable Materials 2019年第2期7卷 117-128页

作者： Larissa Stieven Montagna Isabela cÉSAR Oyama Rita de cÁSSIA Barbosa camargo Lamparelli ana Paula Silva THAIS Larissa do Amaral Montanheiro ana Paula Lemes Federal University of São Paulo(UNIFESP) Institute of Science and TechnologyTechnology Laboratory of Polymers and Biopolymers(TecPBio)Talim330São Josédos CamposSP12231-280BrazilSão Josédos CamposSPBrazil

Biodegradable polymers have been increasingly used for scientific and commercial applications because they are similar to some conventional thermoplastics and exhibit the ability of ***(3-hydroxybutyrate-co-3-hydroxyvalerate)(PHBV)nanocomposites films with 1 and 2 wt% of carbon nanotubes(cNT)were prepared by solution mixing,followed by solvent *** this work,PHBV/cNT nanocomposites were submitted to biodegradation in an aqueous medium for 34 days through a respirometric ***,the PHBV films were analyzed by the cO2 production and mineralization as a response of a microbial attack,which was monitored by back titration during all the *** films were also characterized by measuring the weight loss;crystallinity was evaluated by differential scanning calorimetry(DSc)and the surface morphology by scanning electron microscopy(SEM).By analyzing the weight loss of the films,it was observed that adding cNT increases the resistance to biodegradation *** obtained values of cO2 production and mineralization of the samples,as well as the values of weight loss,showed that the biodegradation of PHBV/cNT nanocomposites was minor in comparison to neat *** addition of cNT in PHBV matrix influences the surface morphology,causing the presence of cavities and an increase of roughness.

关键词： Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) carbon nanotube nanocomposites biodegradation in aqueous medium

Investigation of chlorinated phenols sorption mechanisms on different layers of the Danube alluvial sediment

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Journal of Environmental Sciences 2020年第12期32卷 134-142页

作者： Tamara Apostolovic Jelena Trickovic Marijana Kragulj Isakovski Branislav Jovic Snežana Maletic Aleksandra Tubic Jasmina Agbaba University of Novi Sad Faculty of SciencesDepartment of ChemistryBiochemistry and Environmental ProtectionTrg Dositeja Obradovica 3Novi SadSerbia

The characteristics of the Danube river alluvial sediment are of great importance in assessing the risk for transport of pollutants to drinking water sources. characterization of the sediment column layers has shown that the alluvial sediment, sampled near the city of Novi Sad, is a mesoporous sandy material with certain differences in the properties of individual layers. In order to investigate the sorption mechanisms of four chlorinated phenols(cPs) on the alluvial deposit, static sorption experiments were performed at pH 4, 7 and 10. The results of sorption experiments, confirmed by principal components analysis sugest different mechanisms govern the sorption process at different p H conditions. This can be attributed to the molecular characteristics of cPs, geosorbent properties and to variations in the surface charge of the sorbent at different p H conditions.

关键词： Sorption mechanisms chlorinated phenols Alluvial sediment Principal component analysis