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

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

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Strength and stiffness reduction factors for infilled frames with openings

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Earthquake Engineering and Engineering Vibration 2014年第3期13卷 437-454页

作者： luis D.Decanini Laura Liberatore Fabrizio Mollaioli Department of Structural Engineering and Geothecnics "Sapienza" University of Rome

Framed structures are usually infilled with masonry walls. They may cause a significant increase in both stiffness and strength, reducing the deformation demand and increasing the energy dissipation capacity of the system. On the other hand, irregular arrangements of the masonry panels may lead to the concentration of damage in some regions, with negative effects; for example soft story mechanisms and shear failures in short columns. Therefore, the presence ofinfill walls should not be neglected, especially in regions of moderate and high seismicity. To this aim, simple models are available for solid infills walls, such as the diagonal no-tension strut model, while infilled frames with openings have not been adequately investigated. In this study, the effect of openings on the strength and stiffness of infilled frames is investigated by means of about 150 experimental and numerical tests. The main parameters involved are identified and a simple model to take into account the openings in the infills is developed and compared with other models proposed by different researchers. The model, which is based on the use of strength and stiffness reduction factors, takes into account the opening dimensions and presence of reinforcing elements around the opening. An example of an application of the proposed reduction factors is also presented.

关键词： infilled frames openings strength stiffness reduction factor

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Cell bioenergetics:Simple logics,complex solut

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BIOCELL 2022年第10期46卷 2217-2220页

作者： luis S.MAYORGA Instituto de Histología y Embriología de Mendoza(IHEM Universidad Nacional de CuyoCONICET)Facultad de Ciencias Exactas y NaturalesMendoza5500Argentina

Cells are open systems that exchange energy and molecules with their *** any material system,they perform all the complex activities required for homeostasis and reproduction,obeying the thermodynamic *** viewpoint will argue that the basic logic governing the energy flux required to preserve cell organization and function is simple:to decrease the activation energy(Ea)of specific *** none of the possible chemical reactions and energy transformations inside a cell occur at a measurable speed at room or body *** or other macromolecular structures speed up particular transformations by decreasing the corresponding energetic ***,to maintain the systems in a homeostatic state,capable of sophisticated functions based on this simple strategy requires an inconceivably complex *** conclusion will point to the challenging and intricate problems that cells have solved to carve the highly regulated channel through which the energy flows,fueling the work of these nanoscale machines.

关键词： Thermodynamics Cellular logics Self-organization Complexity

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Less is more:dimensionality reduction as a general strategy for more precise luminescence thermometry

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Light(Science & Applications) 2022年第9期11卷 2127-2139页

作者： ERVING XIMENDES RICCARDO MARIN luis DIAS CARLOS DANIEL JAQUE NanoBIG Departamento de Fisica de MaterialesFacultad de CienciasUniversidad Autónoma de MadridC/Francisco Tomás y Valiente 7Madrid 28049Spain NanoBIG Instituto Ramón y Cajal de Investigación Sanitaria(IRYCIS)Ctra.Colmenar km.9.100Madrid 28034Spain Phantom-g CICECO-Aveiro Institute of MaterialsDepartment of PhysicsUniversity of AveiroAveiro 3810-193Portugal

Thermal resolution(also referred to as temperature uncertainty)establishes the minimum discernible temperature change sensed by luminescent thermometers and is a key figure of merit to rank *** has been done to minimize its value via probe optimization and correction of readout artifacts,but little effort was put into a better exploitation of calibration *** this context,this work aims at providing a new perspective on the definition of luminescence-based thermometric parameters using dimensionality reduction techniques that emerged in the last *** application of linear(Principal Component Analysis)and non-linear(t-distributed Stochastic Neighbor Embedding)transformations to the calibration datasets obtained from rare-earth nanoparticles and semiconductor nanocrystals resulted in an improvement in thermal resolution compared to the more classical intensity-based and ratiometric ***,in turn,enabled precise monitoring of temperature changes smaller than 0.1℃.The methods here presented allow choosing superior thermometric parameters compared to the more classical ones,pushing the performance of luminescent thermometers close to the experimentally achievable limits.

关键词： precise dimensionality luminescence

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Optimal Design of Hybrid Microgrid in Isolated Communities of Ecuador

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Journal of Modern Power Systems and Clean Energy 2024年第2期12卷 488-499页

作者： luis A.Pesantes Ruben Hidalgo-León Johnny Rengifo Miguel Torres Jorge Aragundi JoséCordova-Garcia luis F.Ugarte Facultad de Ingeniería en Electricidad y Computación of Escuela Superior Politécnica del Litoral(ESPOL)University GuayaquilEcuador Department of Electrical Engineering at Universidad Técnica Federico Santa María SantiagoChile IEEE

In rural territories, the communities use energy sources based on fossil fuels to supply themselves with electricity, which may address two main problems: greenhouse gas emissions and high fuel prices. Hence, there is an opportunity to include renewable resources in the energy mix. This paper develops an optimization model to determine the optimal sizing, the total annual investment cost in renewable generation, and other operating costs of the components of a hybrid microgrid. By running a k-means clustering algorithm on a meteorological dataset of the community under study, the hourly representative values become input parameters in the proposed optimization model. The method for the optimal design of hybrid microgrid is analyzed in six operating scenarios considering:(1) 24-hour continuous power supply;(2) load shedding percentage;(3) diesel power generator(genset) curtailment;(4) the worst meteorological conditions;(5) the use of renewable energy sources including battery energy storage systems(BESSs);and(6) the use of genset. A mathematical programming language(AMPL) tool is used to find solutions of the proposed optimization model. Results show that the total costs of microgrid in the scenarios that cover 100% of the load demand(without considering the scenario with 100% renewables) increase by over 16% compared with the scenario with genset operation limitation. For the designs with power supply restrictions, the total cost of microgrid in the scenario with load shedding is reduced by over 27% compared with that without load shedding.

关键词： Battery energy storage system(BESS) isolated community microgrid renewable energy optimization

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Symmetrization for Fractional Elliptic and Parabolic Equations and an Isoperimetric Application(Dedicated to Haim Brezis,great master of analysis,on his 70th birthday)

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Chinese Annals of Mathematics,Series B 2017年第2期38卷 661-686页

作者： Yannick SIRE Juan luis VAZQUEZ Bruno VOLZONE johns hopkins university Krieger Hall3401 N.Charles StBaltimoreM D21218USA. departamento de matemticas universidad autnoma de madrid28049 M adridSpain dipartimento di ingegneria universit degli studi di napoli"parthenope"80143 Italia.

This paper develops further the theory of symmetrization of fractional Laplacian operators contained in recent works of two of the authors. This theory leads to optimal estimates in the form of concentration comparison inequalities for both elliptic and parabolic equations. The authors extend the theory for the so-called restricted fractional Laplacian defined on a bounded domain Ω of R^N with zero Dirichlet conditions outside of Ω. As an application, an original proof of the corresponding fractional Faber-Krahn inequality is derived. A more classical variational proof of the inequality is also provided.

关键词： Symmetrization, Fractional Laplacian, Nonlocal elliptic and parabolicequations, Faber-Krahn inequality

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Adding fifth dimension to optoacoustic imaging: volumetric time-resolved spectrally enriched tomography

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Light(Science & Applications) 2014年第1期3卷 330-334页

作者： Xose luis Dean-Ben Daniel Razansky Institute for Biological and Medical Imaging(IBMI) Technical University of Munich and Helmholtz Center Munich85764 NeuherbergGermany

Optoacoustics provides a unique set of capabilities for bioimaging,associated with the intrinsic combination of ultrasound-and light-related advantages,such as high spatial and temporal resolution as well as powerful spectrally enriched imaging contrast in biological *** demonstrate here,for the first time,the acquisition,processing and visualization of five-dimensional optoacoustic data,thus offering unparallel imaging capacities among the current bioimaging *** newly discovered performance is enabled by simultaneous volumetric detection and processing of multispectral data and is further showcased here by attaining time-resolved volumetric blood oxygenation maps in deep human vessels and real-time tracking of contrast agent distribution in a murine model in vivo.

关键词： biophotonics multispectral optoacoustic imaging photoacoustic tomography

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Glyphosate Dissipation in Different Soils Under No-Till and Conventional Tillage

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Pedosphere 2019年第6期29卷 773-783页

作者： Elena OKADA Joséluis COSTA Francisco BEDMAR Consejo Nacional de Investigaciones Científicas y Técnicas(CONICET) Balcarce 7620(Argentina Estación Experimental Agropecuaria Balcarce Instituto Nacional de Tecnología Agropecuaria(INTA)Balcarce 7620(Argentina Facultad de Ciencias Agrarias Universidad Nacional de Mar del PlataBalcarce 7620(Argentina

Glyphosate is the most used herbicide in Argentina, accounting for 62% of the commercialized pesticides on the market. It is used as a weed controller in no-till systems, and it is also applied to various genetically modified crops ( e.g., soybean, corn, and cotton). Although it has a high solubility in water, it tends to adsorb and accumulate in agricultural soils. The main objectives of this work were to compare the dissipation of glyphosate and the accumulation of its metabolite aminomethylphosphonic acid (AMPA) over time in three soils from agricultural areas of Argentina under long-term management with no-till (NT) and conventional tillage (CT) practices. There were no differences in dissipation between NT and CT, indicating that the glyphosate-degrading microflora was not modified by the different tillage managements. Moreover, tillage practices did not alter the general soil properties;therefore, glyphosate bioavailability was not affected by NT or CT practice. Forty percent of the applied glyphosate was degraded within the first three days in all soils, indicating a fast initial dissipation rate. However, the dissipation rate considerably decreased over time, and the degradation kinetics followed a bi-exponential (or two-compartment) kinetic model. No differences were found between tillage practices. Dissipation was not related to the microbial activity measured as soil respiration. The fast decrease in the concentration of glyphosate at the beginning of the dissipation study was not reflected in an increase in the concentration of AMPA. The estimated half-lives for glyphosate ranged between 9 and 38 d. However, glyphosate bioavailability decreases over time, as it is strongly adsorbed to the soil matrix. This increases its residence time, which may lead to its accumulation in agricultural soils.

关键词： Aminomethylphosphonic acid Bioavailability Biodegradation Herbicide Metabolite Pesticide Two-compartment kinetic model

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Magnetofection as a new tool to study microglia biology

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Neural Regeneration Research 2019年第5期14卷 767-768页

作者： Jose luis Venero Miguel Angel Burguillos Instituto de Biomedicina de Sevilla (IBiS)/Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla and Departamento de Bioquímica y Biología Molecular Facultad de Farmacia Universidad de Sevilla Department of Biochemistry University of Cambridge

Microglia are the resident macrophages of the brain,originally described by Pio del Rio-Hortega(a student of Santiago Ramon y Cajal)in a series of studies in *** those pioneering studies,many others have followed to describe microglia as complex and multitasking cells with many diverse roles under physiological(*** key role in synapse pruning during development)or diseased *** exist as sentinels or surveyors of the environment that surround neurons,becoming reactive upon a wide array of stimuli and consequently developing an appropriate inflammatory *** fact,a neuroinflammatory response driven by microglia is found in virtually every disease process that occurs within the central nervous ***,a better understanding of the mechanisms governing the microglia response is the key to improving the outcome of neurodegenerative conditions.

关键词： Magnetofection new tool study microglia biology

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Perpendicularly Self-Oriented and Shape-Controlled L10-FePt Nanorods Directly Synthesized by a Temperature-Modulated Process

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Nano Research 2011年第7期4卷 666-674页

作者： Tiago luis da Silva Laudemir Carlos Varanda Colloidal Materials Group Instituto de Quimica de Sao Carlos Universidade de Sao Paulo--USP Sao Carlos PO Box 780 13566-590 Brazil

The synthesis and self-assembly of tetragonal phase-containing L10-Fe55Pt45 nanorods with high coercive field is described. The experimental procedure resulted in a tetragonal/cubic phase ratio close to 1：1 for the as-synthesized nanoparticles. Using different surfactant/solvent proportions in the process allowed control of particle morphology from nanospheres to nanowires. Monodisperse nanorods with lengths of 60 ＋ 5 nm and diameters of 2-3 nm were self-assembled in a perpendicular oriented array onto a substrate surface using hexadecylamine as organic spacer. Magnetic alignment and properties assigned, respectively, to the shape anisotropy and the tetragonal phase suggest that the self-assembled materials are a strong candidate to solve the problem of random magnetic alignment observed in FePt nanospheres leading to applications in ultrahigh magnetic recording （UHMR） systems capable of achieving a performance of the order of terabits/in2.

关键词： Magnetic materials data storage FePt nanorods self-assembl~ perpendicular magnetic alignment

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