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Constrained fractional Variational Problems of Variable Order

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IEEE/CAA Journal of Automatica Sinica 2017年第1期4卷 80-88页

作者： Dina Tavares Ricardo Almeida delfim f.m.torres Department of mathematics Polytechnic Institute of Leiria Department of mathematics University of Aveiro

Isoperimetric problems consist in minimizing or maximizing a cost functional subject to an integral *** this work, we present two fractional isoperimetric problems where the Lagrangian depends on a combined Caputo derivative of variable fractional order and we present a new variational problem subject to a holonomic constraint. We establish necessary optimality conditions in order to determine the minimizers of the fractional problems. The terminal point in the cost integral,as well as the terminal state, are considered to be free, and we obtain corresponding natural boundary conditions.

关键词： fractional calculus fractional calculus of variations holonomic constraints isoperimetric constraints optimization variable fractional order

ISOPERImETRIC PROBLEmS Of THE CALCULUS Of VARIATIONS WITH fRACTIONAL DERIVATIVES

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Acta mathematica Scientia 2012年第2期32卷 619-630页

作者： Ricardo Almeida Rui A.C.ferreira delfim f.m.torres Center for Research and Development in mathematics and Applications Department of MathematicsUniversity of Aveiro3810-193 AveiroPortugal Department of mathematics Faculty of Engineering and Natural SciencesLusophone University of Humanities and Technologies1749-024 LisbonPortugal

In this article, we study isoperimetric problems of the calculus of variations with left and right Riemann-Liouville fractional derivatives. Both situations when the lower bound of the variational integrals coincide a... 详细信息

关键词： Calculus of variations fractional derivatives isoperimetric problems

A unified approach to the calculus of variations on time scales

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A unified approach to the calculus of variations on time sca...

Photocatalytic performance of K2Ti6O13 whiskers to H2 evolution and CO2 photo-reduction

2010 Chinese Control and Decision Conference

作者： Ewa Girejko Agnieszka B.malinowska delfim f.m.torres Department of mathematics University of Aveiro3810-193 AveiroPortugal faculty of Computer Science Biatystok University of Technology15-351 BiatystokPoland

ISBN: (纸本)9781424451814;9781424451821

＜正＞In this work we propose a new and more general approach to the calculus of variations on time scales that allows to obtain,as particular cases,both delta and nabla *** precisely,we pose the problem of minimizing or maximizing the composition of delta and nabla integrals with Lagrangians that involve directional *** Euler-Lagrange necessary optimality conditions,as well as sufficient conditions under appropriate convexity assumptions, are *** illustrate presented results with simple examples.

关键词： Euler-Lagrange equations calculus of variations delta and nabla calculi time scales directional derivatives

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Journal of Energy Chemistry 2019年第10期28卷 18-28页

作者： L. f. Garay-Rodríguez L.m.torres-martínez E.moctezuma facultad de Ingeniería Civil-Departamento de Ecomateriales y Energía Universidad Autónoma de Nuevo LeónAv. Universidad S/N Cd. UniversitariaC. P. 66455 San Nicolás de los GarzaNLMéxico facultad de Ciencias Químicas Universidad Autónoma de San Luis PotosíAv. Manuel Nava#6C. P.78290 San Luis PotosíSLPMéxico

K2Ti6O13 whiskers were synthesized by conventional sol-gel method, sono-chemical assisted and microwave assisted sol-gel method in order to obtain catalysts with different particle sizes and to modify their optical, textural and electrochemical properties. These modifications improved their photocatalytic activity for H2 evolution and CO2 photo-reduction. Long K2Ti6O13 whiskers prepared by ultrasound assisted sol-gel method are the most active photocatalysts for the hydrogen evolution reaction using pure water as reactant (U-SG, 10,065 μmol g^-1). In contrast, an opposite behavior was observed using a mixture of ethanol-water, where the highest activity was achieved by the shortest and less crystalline K2Ti6O13 whiskers (C-SG, 3,2871 μmol g^-1). In case of CO2 photo-reduction, long whiskers that were also prepared by the sono-chemical assisted sol-gel method were the most active to transform CO2 to formaldehyde, methane, methanol and hydrogen. The EfB value of this catalyst is located very close to the potential for formaldehyde production and favors the selectivity to this organic product.

关键词： K2Ti6O13 Sol-gel Whiskers Hydrogen evolution CO2 reduction

Plant cover as an estimator of above-ground biomass in semi-arid woody vegetation in Northeast Patagonia,Argentina

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Journal of Arid Land 2021年第9期13卷 918-933页

作者： Laura B RODRIGUEZ Silvia S torres ROBLES marcelo f ARTURI Juan m ZEBERIO Andrés C H GRAND Néstor I GASPARRI National University of Río Negro Atlantic HeadquartersCenter for Environmental Studies from Norpatagonia(CEANPa)Viedma 8500Argentina National Council of Scientific and Technical Research(CONICET) Viedma 8500Argentina Ecological and Environmental Systems Research Laboratory(LISEA) National University of La PlataLa Plata 1900Argentina National Institute of Agricultural Technology(INTA) AER PatagonesCarmen de Patagones 8504Argentina Institute of Regional Ecology(IER) National University of Tucumán(UNT)-National Council of Scientific and Technical Research(CONICET)Tucumán 4000Argentina faculty of Natural Sciences and miguel Lillo Institute National University of Tucumán(UNT)Yerba Buena 4107Argentina

The quantification of carbon storage in vegetation biomass is a crucial factor in the estimation and mitigation of CO2 ***,arid and semi-arid regions are considered an important carbon ***,they have received limited attention and,therefore,it should be a priority to develop tools to quantify biomass at the local and regional *** plant variables,such as stem diameter and crown area,were reported to be good predictors of individual plant ***-level variables,such as plant cover and mean height,are also easy-to-measure estimators of above-ground biomass(AGB)in dry *** this study,we estimated the AGB in semi-arid woody vegetation in Northeast Patagonia,*** evaluated whether the AGB at the stand level can be estimated based on plant cover and to what extent the estimation accuracy can be improved by the inclusion of other field-measured structure *** also evaluated whether remote sensing technologies can be used to reliably estimate and map the regional mean *** this purpose,we analyzed the relationships between field-measured woody vegetation structure variables and AGB as well as LANDSAT Tm-derived *** obtained a model-based ratio estimate of regional mean AGB and its standard *** plant cover allowed us to obtain a reliable estimation of local AGB,and no better fit was attained by the inclusion of other structure *** stand-level plant cover ranged between 18.7%and 95.2%and AGB between about 2.0 and 70.8 mg/hm^(2).AGB based on total plant cover was well estimated from LANDSAT Tm bands 2 and 3,which facilitated a model-based ratio estimate of the regional mean AGB(approximately 12.0 mg/hm^(2))and its sampling error(about 30.0%).The mean AGB of woody vegetation can greatly contribute to carbon storage in semi-arid ***,plant cover estimation by remote sensing images could be used to obtain regional estimates and map biomass,as well as to assess and monitor the i

关键词： above-ground biomass shrublands ratio estimation carbon storage remote sensing Patagonia

Dothiorella vidmadera, a novel species from grapevines in Australia and notes on Spencermartinsia

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fungal Diversity 2013年第4期61卷 209-219页

作者： Wayne m.Pitt Jose RamonÚrbez-torres florent P.Trouillas National Wine and Grape Industry Centre School of Agricultural and Wine SciencesCharles Sturt UniversityLocked Bag 588Wagga WaggaNSW 2678Australia Pacific Agri-food Research Centre 4200 Highway 97Box 5000SummerlandBC V0H1Z0Canada Department of Plant Pathology University of CaliforniaDavisCA 95616USA

Strains of a coelomycete isolated from grapevine cankers in southeastern Australia and identified as Dothiorella iberica in previous studies are redescribed in this study as a novel species based on morphological characters and phylogenetic analyses of DNA sequences of the internal transcribed spacer region(ITS1-5.8S-ITS2),and partial sequences of the translation elongation factor 1-αandβ-tubulin *** vidmadera *** most closely related to ***,*** and ***,but differs in morphological characters and DNA *** four species are known to be associated with Botryosphaeria dieback of ***,an unidentified ascomycete isolated from dead wood of grapevines in Western Australia is ***,strains were most closely related to Spencermartinsia viticola,and bore conidia with morphological characters and dimensions consistent with published ***,ascospores were shorter and narrower than previously reported and lacked the terminal apiculi that typify the genus.

关键词： Botryosphaeriaceae Grapevine trunk diseases Grapevine canker multigene phylogeny Taxonomy

Use of two-surfactants mixtures to attain specific HLB values for assisted TPH-diesel biodegradation

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Journal of Environmental Sciences 2004年第6期16卷 950-956页

作者： Luis G. torres Neftalí Rojas Rosario Iturbe Instituto de Ingeniería Universidad Nacional Autó noma de México Coordinación de Ingeniería Ambiental Grupo Saneamiento de Suelos y Acuíferos Apartado Postal 70-472 Coyoacán 04510 México D.F. Mexico

In a surfactant assisted biodegradation process, the choice of surfactant(s) is of crucial importance. The question is: does the type of surfactant(i.e. chemical family) affect the biodegradation process at fixed hidrophillic-lypofillic balance(HLB) values? microcosm assessments were developed using contaminated soil, with around of 5000 mg/kg of hydrocarbons as TPH-diesel. mixtures of three nonionic surfactants were employed to get a wide range of specific HLB values. Tween20 and Span20 were mixed in the appropriate proportions to get HLB values between 8.6 and 16.7. Tween/Span60 mixtures reached HLB values between 4.7 and 14.9. finally, Tween/Span80 combinations yielded HLB values between 4.3 and 15. TPH-diesel biodegradation was measured at the beginning, and after 8 weeks, as well as the fCU/gr soil, as a measure of microorganisms′ development during the biodegradation period. A second aim of this work was to assess the use of guar gum as a biodegradation enhancer instead of synthetic products. The conclusions of this work are that surfactant chemical family, and not only the HLB value clearly affects the assisted biodegradation rate. Surfactant's synergism was clearly observed. Regarding the use of guar gum, no biodegradation enhancement was observed for the three assessed concentrations, i.e., 2, 20, and 200 mg/kg, respectively. On the contrary, TPH-diesel removal was lower as the gum concentration increased. It is quite possible that guar gum was used as a microbial substrate.

关键词： aged soils enhanced bioremediation HLB mixtures Tween Span surfactants

Compliant lightweight non-invasive standalone“marine Skin”tagging system

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npj flexible Electronics 2018年第1期2卷 97-105页

作者： Joanna m.Nassar Sherjeel m.Khan Seneca J.Velling Andrea Diaz-Gaxiola Sohail f.Shaikh Nathan R.Geraldi Galo A.torres Sevilla Carlos m.Duarte muhammad m.Hussain mmh Labs Computer Electrical Mathematical Science and Engineering DivisionKing Abdullah University of Science and Technology(KAUST)Thuwal 23955-6900Saudi Arabia material&Nanoscience Program Faculty of ScienceUniversity of WaterlooWaterlooON N2L-3G1Canada Red Sea Research Center(RSRC) Biological and Environmental Sciences and Engineering(BESE)DivisionKing Abdullah University of Science and Technology(KAUST)Thuwal 23955-6900Saudi Arabia

Current marine research primarily depends on weighty and invasive sensory equipment and telemetric network to understand the marine environment,including the diverse fauna it contains,as a function of animal behavior and size,as well as equipment *** match animal morphology and activity within the surrounding marine environment,here we show a physically flexible and stretchable skin-like and waterproof autonomous multifunctional system,integrating Bluetooth,memory chip,and high performance physical *** sensory tag is mounted on a swimming crab(Portunus pelagicus)and is capable of continuous logging of depth,temperature,and salinity within the harsh ocean *** fully packaged,ultra-lightweight(mpliant“marine Skin”system does not have any wired connection enabling safe and weightless cuttingedge approach to monitor and assess marine life and the ecosystem’s health to support conservation and management of marine ecosystems.

关键词： marine system Skin

Effects of aeration on the suspended matter from a tropical and eutrophic estuary

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Journal of Environmental Sciences 2019年第12期31卷 175-186页

作者： Natascha Krepsky maria das Gracas S.Bispo Luiz f.fontana frederico S.da Silva Jodo P.m.torres Olaf malm Cleverson G.Silva mirian A.C.Crapez Laboratory of marine Geology Fluminense Federal UniuersityAue.Gen.Milton Tauares de Souza s/n°-Gragoata24210-346 NiterdiRJBrazil Radioisotopes Laboratory Eduardo Penna franca Biophysics Institute Carlos Chagas FilhoFederal University of Rio de JaneiroAu.Carlos Chagas Filho373 CCS-Bl.G21941-902 Rio de JaneiroRJBrazil marine Biology Department Fluminense Federal UniversityR.Mario Santos Bragas/nNiteroi24.020-141 NiteroiRJBrazil

A comprehensive understanding of the complex biogeochemical interactions between organic matter and persistent contaminants in the suspended matter is vital for ecoefficient estuary ***,little is known regarding aeration effects in suspended particulate ***,this study aimed to investigate the effects of aeration on the suspended matter from a Tropical and Eutrophic estuarine *** water with 60 g/L of suspended particulate matter(SPm)was collected from Guanabara Bay,Rio de Janeiro,Brazil,transferred to experimental boxes and aerated for 61 *** aggregates monitoring included abiotic variables measurements and,determination of total organic matter(TOm),biopolymers composition,bacterial activity,trace metals,and polycyclic aromatic hydrocarbons(PAHs)*** aeration enhanced dissolved oxygen(DO)concentration and the redox potential(Eh).However,from days 0 to 61 the predominant bacterial activities were denitrification and *** transport system activity increased after day 10,and aerobic activity was detected after day *** summary,aeration increased aerobic bacterial activity,lipids(LIP)and trace metal concentrations,although diminished protein/carbohydrate ratio and PAH *** metals concentration(Ni,Pb,Cu,Cr,mn,and fe)were the highest on day 19 when the p H was *** presented toxic values(Cu>20.0μg/g).The p H showed a strong negative correlation with Eh(r=-0.94;pment(p H≤5.9)in marine ecosystems with high loads of toxic trace metals is unsafe for ***,managers must be aware of the environmental and biological risks of introducing the aeration technique into a eutrophic marine environment.

关键词： mixed-pollution Remediation Acidification Esterases enzymes Biopolymer