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Valorization of Kraft Lignin as Thickener in Castor Oil for Lubricant Applications

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journal of Renewable Materials 2018年第4期6卷 347-361页

作者： A.M.Borrero-Lopez f.j.santiago-medina C.Valencia M.E.Eugenio R.Martin-Sampedro j.M.franco Department of Chemical Engineering University of HuelvaEl Carmen CampusAgrifood Campus of International Excellence(ceiA3)21071 HuelvaSpain Pro2TecS-Chemical Process and Product Technology Research Center University of Huelva21071 HuelvaSpain INIA-CIfOR Ctra de la Coruñakm 7.5.28040MadridSpain

It is known that large amounts of residual lignin are generated in the pulp and paper industry.A new alternative for Kraft lignin valorization,which consists of first a chemical modification using a diisocyanate and then the efficient dispersion in castor oil to achieve stable gel-like systems,is proposed in this *** properties and microstructure of these materials were determined by means of small amplitude oscillatory shear tests and viscous flow measurements and atomic force microscopy observations,***,both standardized penetration tests and tribological assays,usually performed in the lubricant industry,were carried out to evaluate the performance characteristics as lubricating *** viscoelasticity functions are affected by the lignin/diisocyanate ratio and thickener *** thermorheological response evidenced a softening temperature of around 105°*** microstructure of these gel-like dispersions is composed of interconnected thin fibers,homogeneously distributed in castor ***,the NCO-functionalized lignin gel-like dispersions studied show lower friction coefficients than traditional lubricating greases.

关键词： Kraft lignin diisocyanate gel-like dispersion rheology thermal properties

Catalytic performance of zinc-supported copper and nickel catalysts in the glycerol hydrogenolysis

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journal of Energy Chemistry 2020年第3期29卷 185-194页

作者： R.j.Chimentao B.C.Miranda D.Ruiz f.Gispert-Guirado f.medina j.Llorca j.B.O.Santos Physical Chemistry Department Faculty of Chemical SciencesUniversity of ConcepcionCasilla 160-CConcepcionChile Chemical Engineering School Universidad de Costa Ric1San Jose 2060Costa Rica Scientific Resources Service Universitat Rovira i VirgiliTarragona 43007Spain Department of Chemical Engineering Universitat Rovira i VirgiliTarragona 43007Spain Department of Chemical Engineering Barcelona Research Center in Multiscale Science and EngineeringInstitute of Energy TechnologiesUniversitat Politècnica de Cataluny1EEBE08019 Barcelon1Spain Department of Chemical Engineering Universidade Federal de Sao Carlos(UFSCAR)Sao CarlosBrazil

Gas-phase catalytic conversion of glycerol to value added chemicals was investigated over zinc-supported copper and nickel *** addition of aluminum in the support was also investigated in glycerol conversion and the results indicate an increase in the acidity and adsorption capacity for both copper and nickel *** and XRD analysis revealed Ni Zn alloy formation in the Ni/ZnO *** XRD patterns of the prepared Zn Al mixed oxide catalysts show the presence of Gahanite phase(ZnAl2O4).In addition,H2 chemisorption and TPR results suggest a strong metal-support interactions(SMSI)effect between Ni and Zn O *** supports Zn O and ZnAl(Zn/Al=0.5)were investigated in the glycerol conversion and they did not present *** supported on ZnO and ZnAl mixed oxide(Zn/Al=0.5)was active towards hydroxyacetone *** was active in the hydrogenolysis of glycerol both for C–C and C–O bonds cleavage of glycerol producing *** metal-support interactions(SMSI)between Ni and ZnO has a remarkable suppression effect on the methanation activity during the glycerol conversion.

关键词： Glycerol Hydrogenolysis Dehydration Hydroxyacetone Copper Nickel Catalyst

Power factor Estimation of Distributed Energy Resources Using Voltage Magnitude Measurements

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journal of Modern Power Systems and Clean Energy 2021年第4期9卷 859-869页

作者： Samuel Talkington santiago Grijalva Matthew j.Reno School of Electrical and Computer Engineering Georgia Institute of TechnologyAtlantaGA 30318USA Electric Power Systems Research Department Sandia National LaboratoriesAlbuquerqueNM 87123USA

This paper presents a new method for the estimation of the injection state and power factor of distributed energy resources (DERs) using voltage magnitude measurements only. A physics-based linear model is used to develop estimation heuristics for net injections of real and reactive power at a set of buses under study, allowing a distribution engineer to form a robust estimate for the operating state and the power factor of the DER at those buses. The method demonstrates and exploits a mathematical distinction between the voltage sensitivity signatures of real and reactive power injections for a fixed power system model. Case studies on various test feeders for a model of the distribution circuit and statistical analyses are presented to demonstrate the validity of the estimation method. The results of this paper can be used to improve the limited information about inverter parameters and operating state during renewable planning, which helps mitigate the uncertainty inherent in their integration.

关键词： Decentralized power system control detection and estimation power factor sparse approximation

Phase Transformation under Continuous Cooling Conditions in Medium Carbon Microalloyed Steels

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journal of Materials Science & Technology 2014年第5期30卷 511-516页

作者： Manuel Gomez Lucia Rancel Esther Escudero Sebastian f.medina National Centre for Metallurgical Research CENIM-CSICAv.Gregorio del Amo 828040 MadridSpain

Several 35CrMo4 and 38MnV7 steels with different additions of Ti and V were manufactured by electroslag remelting. The influence of the alloying and microalloying elements on phase transformation at different cooling rates was studied and the continuous cooling transformation diagrams were plotted. In order to optimize the heat treatment and improve the mechanical properties, the range of cooling rates leading to a fully bainitic microstructure （without ferrite, pearlite and especially without martensite） was determined. Bainite and martensite transformation start temperatures （Bs, Ms） were also established and compared with the values predicted by empirical equations. The important role of precipitates （especially V carbonitride particles） on final microstructure and mechanical properties was assessed.

关键词： Microalloyed steel Phase transformation Precipitation Dilatometry Continuous cooling transformation diagram

Study on Characteristics of Co-firing Ammonia/Methane fuels under Oxygen Enriched Combustion Conditions

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journal of Thermal Science 2018年第3期27卷 270-276页

作者： XIAO Hua WANG Zhaolin VALERA-medina Agustin BOWEN Philip j School of Engineering Cardiff University College of Energy Xiamen University

Having a background of utilising ammonia as an alternative fuel for power generation, exploring the feasibility of co-firing ammonia with methane is proposed to use ammonia to substitute conventional natural gas. However, improvement of the combustion of such fuels can be achieved using conditions that enable an increase of oxygenation, thus fomenting the combustion process of a slower reactive molecule as ammonia. Therefore, the present study looks at oxygen enriched combustion technologies, a proposed concept to improve the performance of ammonia/methane combustion. To investigate the characteristics of ammonia/methane combustion under oxygen enriched conditions, adiabatic burning velocity and burner stabilized laminar flame emissions were studied. Simulation results show that the oxygen enriched method can help to significantly enhance the propagation of ammonia/methane combustion without changing the emission level, which would be quite promising for the design of systems using this fuel for practical applications. furthermore, to produce low computational-cost flame chemistry for detailed numerical analyses for future combustion studies, three reduced combustion mechanisms of the well-known Konnov's mechanism were compared in ammonia/methane flame simulations under practical gas turbine combustor conditions. Results show that the reduced reaction mechanisms can provide good results for further analyses of oxygen enriched combustion of ammonia/methane. The results obtained in this study also allow gas turbine designers and modellers to choose the most suitable mechanism for further combustion studies and development.

关键词： Ammonia/Methane Oxygen-enriched Combustion Reduced Mechanism Gas Turbine

Structural studies of BaTiO_3:Er^(3+) and BaTiO_3:Yb^(3+) powders synthesized by hydrothermal method

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journal of Rare Earths 2014年第11期32卷 1016-1021页

作者： Garrido-Hernández A García-Murillo A Carrillo-Romo f de j Cruz-santiago L A Chadeyron G Morales-Ramírez A de j Velumani S T.A. Post-graduate Student. Instituto Politécnico Nacional CIITEC IPN Cerrada de Cecati S/N. Col. Santa Catarina Azcapotzalco México D.F. C.P. 02250 México D.F México Instituto Politécnico Nacional CIITEC IPN Cerrada de Cecati S/N. Col. Santa Catarina Azcapotzalco México D.F. C.P. 02250 México D.F Departament of Engineering Materials Tecnológico de Estudios Superiores de Coacalco (TESCo) Av. 16 de Septiembre # 54 Cabecera Municipal C.P. 55700 Coacalco de Berriozábal Estado de México Institut de Chimie de Clermont-ferrand UMR 6296 CNRS / UBP / ENSCCF 24 avenue des Landais BP 80026 63171 Aubière Cedex – France Department of Electrical Engineering (SEES) Centro de Investigación y de Estudios Avanzados del IPN Av. Instituto Politécnico Nacional 2508 Col. San Pedro Zacatenco C.P. 07360 Mexico D.F. Mexico

Erbium and ytterbium doped barium titanate nanopowders were prepared using the hydrothermal method. A barium titanate structure doped with rare earth ions manifested new characteristics and improved the field of application of optical devices such as trichromatic tubes, LCD displays, lamps, and infrared lasers. In this work, BaTiO3：Er3＋ and BaTiO3：Yb3＋ were prepared using barium chloride [BaCl2], titanium butoxide [C16H36O4Ti], erbium chloride [ErCl3] and ytterbium chloride [YbCl3] as precursors. Anhydrous methanol was employed as a solvent. Metallic potassium was used to promote solubility in the system and increase the pH to 13. This method yielded the formation of a predominantly cubic structure in both Er3＋ and Yb3＋ doped BaTiO3 powders. Characteristic bondings of BaTiO3 were observed with fT-IR spectroscopy. The predominantly cubic structure was confirmed by X-ray diffraction and micro-Raman analyses. The particle size（～30 nm） was estimated using the Scherrer equation and X-ray diffraction data. The results were presented and discussed.

关键词： nanopowders hydrothermal BaTiO3:Er3+ BaTiO3:Yb3+ rare earths

The logically consistent relationship between cladograms and synapomorphies

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Zoological Systematics 2024年第4期49卷 281-284页

作者： santiago j.Sanchez-Pacheco Direccion Academica Universidad Nacional de ColombiaSede de La PazLa PazCesarColombia

Here I explore the biological relevance,origin and meaning of the concept of cladogram(rooted,directed branching diagrams representing the hypothesized phylogenetic relationships among the terminal taxa under study)and argue that cladograms do not necessarily entail synapomorphies,but synapomorphies are required to test and ultimately falsify cladograms.

关键词： meaning sized among

Raman-IR vibrational and XRD characterization of ancient and modern mineralogy from volcanic eruption in Tenerife Island： Implication for Mars

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Geoscience frontiers 2016年第4期7卷 673-681页

作者： E.A.Lalla G.Lopez-Reyes A.Sansano A.Sanz-Arranz j.Martinez-frias j.medina f.Rull-Perez department of physics faculty of science university of la laguna san cristobal de la laguna santa cruz de tenerifeCP 38206 spain Unidad Asociada al Centro de Astrobiologfa CSIC-INTA Associated to the NASA Astrobiology Center-Instituto Nacional de Tecnica Aeroespacial Torrejon de ArdozCP 28850MadridSpain Department of Earth Dynamics and Observation lnstituto de Ceociencias IGEO-(CSIC-UCM)Facultad de Ciencias Geologicas.Ciudad UniversitariaCP 28040MadridSpain

A detailed vibrational Raman-lR spectroscopic and diffractional analyses have been performed on basalts from two locations from Tenerife Island：（1） the Arenas Negras volcano which belongs to the historical eruption not showing visible alteration and （2） Pillow Lavas zone from Anaga Massif which shows a clearly fluid-rock interaction caused by submarine alteration. These places have been extensively studied due to its similarity with the surface of Mars. The analysis is based on the mineral detection of selected samples by a Micro-Raman study of the materials. The complementary techniques have confirmed the mineralogy detected by the Raman measurement. The results show a volcanic environment behavior with primary phases like olivine, pyroxene, and feldsparjplagioclase. Moreover, the presence of accessory minerals or secondary mineralization like phosphate, iron oxides, zeolite or carbonates shows the alteration processes on each outcrop. The variation in the crystallinity and amorphous phases is related to fluid-rock interaction caused by hydrothermal episodes and external weathering processes, which shows several analogies with the ancient volcanic activity from Mars.

关键词： Mars Volcanoes Terrestrial analog Raman spectroscopy Tenerife Island Mineralogy

Subtle sexual plumage color dimorphism and size dimorphism in a South American colonial breeder, the Monk Parakeet(Myiopsitta monachus)

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Avian Research 2020年第2期11卷 157-165页

作者： Macarena Morales Deysi j.Gigena santiago MBenitez‑Vieyra Diego j.Valdez facultad de Ciencias Exactas Físicas y NaturalesCentro de Zoología AplicadaUniversidad Nacional de CórdobaRondeau 798CP X5000AVP CórdobaArgentina Instituto de Diversidad y Ecología Animal(IDEA) Consejo Nacional de Investigaciones Científicas y Técnicas(CONICET)Av.Vélez Sarsfield 299X5000JJC CórdobaArgentina Departamento de Diversidad Biológica y Ecología Facultad de Ciencias ExactasFísicas y NaturalesUniversidad Nacional de CórdobaAv.Vélez Sarsfield 299CP 5000 CórdobaArgentina Instituto Multidisciplinario de Biología Vegetal(IMBIV) Consejo Nacional de Investigaciones Científicas y Técnicas(CONICET)Av.Vélez Sarsfield 1666CP X5016GCN CórdobaArgentina

Background:Parrots(Psittacidae family)are one of the most colorful groups of birds in the world,their colors pro-duced both structurally and via unusual pigments(psittacofulvins).Most species are considered to be monogamous,and many have been viewed historically as sexually monomorphic and ***,studies using morphometric analysis and spectrophotometric techniques have revealed sexual size dimorphism and also sexual plumage color dimorphism among some *** Monk Parakeet(Myiopsitta monachus),a native parrot of South America,is an interesting species for the study of plumage coloration and size since it is considered sexually mono-chromatic and ***,recent studies show that the Monk Parakeet has extra-bond paternity behavior and even breeding trios,which suggests that sexual selection may play an important role in this species,and that it might have sexually dimorphic plumage(albeit imperceptible by humans)and be dimorphic in ***:for the determination of plumage color we used spectrophotometry in the range of avian vision(300-700 nm)and performed a morphological ***:Our spectrophotometric results indicate that the Monk Parakeet shows subtle sexual plumage color dimor-phism in three(crown,nape and wing)out of twelve body ***,our morphometric analysis showed that there are subtle sex differences in body size(bill and weight).Conclusions:Although the Monk Parakeet shows extra-bond paternity and breeding trio behaviors which could increase sexual dimorphism,these behaviors occur among highly related individuals;perhaps the high rate of inbreeding is responsible for the attenuation of sexual plumage color dimorphism and sex differences in body size observed.

关键词： Argentina Avian vision Colonial breeder Myiopsitta monachus Parrot Sexual plumage color dimorphism Sexual size dimorphism