173 research outputs found

    CODEA : an agent based multi-objective optimization framework

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    This work presents CODEA, a COoperative DEcentralized Architecture for Multiobjective Optimization. CODEA is an objectoriented framework that aims at the creation of groups of agents to tackle complex problems by cooperative search. This cooperation is carried out without any individual controlling the cooperation nor the behaviour of the agents. Each agent works on its own to improve itself and collaborates to improve the performance of the group by sharing information

    Nature of real-world multi-objective vehicle routing with evolutionary algorithms

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    The Vehicle Routing Problem with Time Windows VRPTW) is an important logistics problem which in the realworld appears to be multi-objective. Most research in this area has been carried out using classic datasets designed for the single-objective case, like the well-known Solomon's problem instances. Some unrealistic assumptions are usually made when using these datasets in the multi-objective case (e.g. assuming that one unit of travel time corresponds to one unit of travel distance). Additionally, there is no common VRPTW multiobjective oriented framework to compare the performance of algorithms because different implementations in the literature tackle different sets of objectives. In this work, we investigate the conflicting (or not) nature of various objectives in the VRPTW and show that some of the classic test instances are not suitable for conducting a proper multi-objective study. The insights of this study have led us to generate some problem instances using d ata from a real-world distribution company. Experiments in these new dataset using a standard evolutionary algorithm NSGA-II) show stronger evidence of multi-objective features. Our contribution focuses on achieving a better understanding about the multi-objective nature of the VRPTW, in particular the conflicting relationships between 5 objectives: number of vehicles, total travel distance, makespan, total waiting time, and total delay time

    The Effects Of Plastics Intake on Drosophila

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    Drosophila melanogaster is commonly used as a model organism to study countless human health-related issues and concerns (Pandey et al., 2011. From a global aspect, pollution, in all its forms, is an ever-growing concern. In particular, plastics, due to their incapability to decompose, has raised many questions pertaining to the effect this will have on our already struggling planet and ultimately what those effects mean for the human race. Plastics are composed of a group of chemicals known as phthalates which allow the material to be as flexible and durable as it is. Phthalates are also used in a widespread category for other commonly used products such as nail polishes, shampoos, soaps, hair sprays, detergents, vinyl flooring, lubrication oils, toys, medical equipment, plastic in clothing, adhesives, car parts, etc (Center for Disease Control and Prevention, 2017). Phthalates are in nearly everything we use, on the floors of the cities we walkthrough, and even in the air, we breathe. Effects on human health in relation to the exposure of phthalates are unknown since this is a relatively new concern in our era (CDCP, 2017). This study looks to measure the effects of phthalates on many aspects of Drosophila development and lifespan in order to predict potential human health threats. By diluting a solvent form of phthalates and using the CAFE assay (Diegelmann et al, 2017) we are developing an assay for phthalate exposure and its various potential effects

    Spectroscopic detection of carbon nanotube interaction with amphiphilic molecules in epoxy resin composites

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    Incorporation of carbon nanotubes into epoxy resin composites has the effect of increasing electrical conductivity at low percolation levels. An amphiphilic molecule such as palmitic acid has been used to increase the surface contact area and improve the dispersion of the carbon nanotube bundles in the prepolymer. The chemical environment of the dispersed nanotubes has been probed using vibrational Raman spectroscopy. Spectroscopic Raman maps, on sample surfaces (60x60 ”m2) with ratios of nanotubes to palmitic acid varying from 1:2 to 2:1 by weight, have been recorded to test the uniformity of the dispersion. Substantial spatial inhomogeneities have been observed in the G-band shift and an additional spectral band at 1450 cm-1. The 1450 cm-1 band has been attributed to the CH3 group of the amphiphilic molecules adsorbed onto the nanotube surface. The maps are correlated with the measured electrical conductivity values. The highest conductivity has been observed for the best dispersed nanotubes and nanotubes with the highest degree of interaction

    Association of 5-HT1A Receptors with Affective Disorders

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    Serotonin or 5-hydroxytryptamine (5-HT) is synthesized in both the brain and peripheral system, which exert their actions at a wide family of receptors classified as 5-HT1 to 5-HT7. Pharmacological, behavioral, and clinical studies involve particularly to the 5-HT1A receptors (5-HT1A-R) - auto-receptors (presynaptic) and heteroreceptors (postsynaptic) - in the control of motivated behavior, and consequently in the physiopathology of affective disorders and in the action mechanism of antidepressant drugs. In this way, some research support that 5-HT1A-R participates in the delayed effect of different types of antidepressants, including selective serotonin reuptake inhibitors (SSRIs), and tricyclic drugs, principally. The therapeutic effect of serotonergic drugs as the SSRIs, starting with the binding to auto-receptors, which produces increases of 5-HT in the synaptic cleft as consequence of blockade of serotonin reuptake. While these molecular events occur initially, in the long-term are produced plastic changes at neuronal level, as well as down-regulation of the 5-HT1A-R, which is associated with the therapeutic effects of antidepressant drugs. The purpose of this chapter is to analyze and discuss the current information about of 5-HT1A-R-mediated signaling cascades, the intracellular signaling of 5-HT1A-R, in addition to their expression and pharmacology that are important to treatment of affective disorders symptoms

    Occupational Health and Safety Prevention Plan in Water Treatment Plant

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    The research was carried out at the "El Guarumo" drinking water plant located in Santa Ana, province of ManabĂ­, Ecuador. The objective of the investigation was the proposal of a plan of prevention of occupational risks that allows the management of the labor risks in said plant. The main tools used were: survey, interview, checklist, LEST questionnaire for the diagnosis of the current situation in terms of working conditions, the risk identification matrix and the binary method of risk assessment. The main results obtained were the identification of the risks in their different categories, observing that the critical risk factors are related to the physical overexertion, the uncomfortable postures and the manual lifting of the load. Among the important risks are falling objects, skin contact with toxic substances and mental overwork, closely related to work pressures and job security? It was possible to carry out the proposal of preventive and corrective measures in order to properly manage the risks and contribute to the safety and health of the workers

    Magnetic and elastic anisotropy in magnetorheological elastomers using nickel-based nanoparticles and nanochains

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    Nickel (Ni) based nanoparticles and nanochains were incorporated as fillers in polydimethylsiloxane (PDMS) elastomers and then these mixtures were thermally cured in the presence of a uniform magnetic field. In this way, macroscopically structured-anisotropic PDMS-Ni based magnetorheological composites were obtained with the formation of pseudo-chains-like structures (referred as needles) oriented in the direction of the applied magnetic field when curing. Nanoparticles were synthesized at room temperature, under air ambient atmosphere (open air, atmospheric pressure) and then calcined at 400 °C (in air atmosphere also). The size distribution was obtained by fitting SAXS experiments with a polydisperse hard spheres model and a Schulz-Zimm distribution, obtaining a size distribution centered at (10.0 - 0.6) nm with polydispersivity given by sigma= (8.0 ± 0.2) nm. The SAXS, XRD and TEM experiments are consistent with single crystal nanoparticles of spherical shape (average particle diameter obtained by TEM: (12 ± 1) nm). Nickel-based nanochains (average diameter: 360 nm; average length: 3 mm, obtained by SEM; aspect ratio=length/diameter ~10) were obtained at 85 ÂșC and ambient atmosphere (open air, atmospheric pressure). The magnetic properties of Ni-based nanoparticles and nanochains at room temperature are compared and discussed in terms of surface and size effects. Both Ni-based nanoparticles and nanochains were used as fillers for obtaining the PDMS structured magnetorheological composites, observing the presence of oriented needles. Magnetization curves, ferromagnetic resonance spectra (FMR) and strain-stress curves of low fillerÂŽs loading composites (2% w/w of fillers) were determined as functions of the relative orientation respect to the needles. The results indicate that even at low loadings it is possible to obtain magnetorheological composites with anisotropic properties, with larger anisotropy when using nanochains. For instance, the magnetic remanence, the FMR-resonance field and the elastic response to compression are higher when measured parallel to the needles (about 30% with nanochains as fillers). Analogously, the elastic response is also anisotropic, with larger anisotropy when using nanochains as fillers. Therefore, all experiments performed confirm the high potential of nickel nanochains to induce anisotropic effects in magnetorheological materials.Fil: Landa, Romina AilĂ­n. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Oficina de Coordinacion Administrativa Ciudad Universitaria. Instituto de QuĂ­mica FĂ­sica de los Materiales del Medioambiente y EnergĂ­a; Argentina;Fil: P Soledad Antonel. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Oficina de Coordinacion Administrativa Ciudad Universitaria. Instituto de QuĂ­mica FĂ­sica de los Materiales del Medioambiente y EnergĂ­a; Argentina;Fil: Mariano M. Ruiz. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Oficina de Coordinacion Administrativa Ciudad Universitaria. Instituto de QuĂ­mica FĂ­sica de los Materiales del Medioambiente y EnergĂ­a; Argentina;Fil: Oscar E PĂ©rez. Universidad de Buenos Aires. Facultad de Cs.exactas y Naturales. Departamento de Industrias;Fil: Alejandro Butera. ComisiĂłn Nacional de EnergĂ­a AtĂłmica;Fil: Guillermo Jorge. Universidad Nacional de General Sarmiento;Fil: Cristiano L. P. Oliveira. Instituto de FĂ­sica, Universidade De SĂŁo Paulo; Brasil;Fil: MartĂ­n Negri. Universidad de Buenos Aires. Facultad de Cs.exactas y Naturales. Departamento de Industrias

    Regional carbon fluxes and the effect of topography on the variability of atmospheric CO2.

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    Using a mesoscale atmospheric circulation model, it is shown that relatively modest topography height differences of ∌500 m over 200 km near Zotino (60°N, 89°E) in central Siberia may generate horizontal gradients in CO<inf>2</inf> concentration in the order of 30 ppm. In a case study for 15 and 16 July 1996, when Lloyd et al. (2001) conducted a convective boundary layer budget experiment in the area, we show that advection of these gradients disturbs the relation between diurnal concentration changes in the boundary layer and the surface fluxes. This demonstrates that mesoscale atmospheric heterogeneity may have severe impact on the applicability of methods to derive the regional-scale fluxes from CO<inf>2</inf> concentrations measurements, such as the convective boundary layer budget method or inverse modeling. It is shown that similar mesoscale gradients are likely to occur at many long-term observation stations and tall towers. We use the modeled concentration fields to quantify the horizontal and vertical variability of carbon dioxide in the atmosphere. In future observation campaigns, mesoscale processes may be best accounted for by measuring horizontal variability over a few hundred kilometers and by attempting to quantify the representation errors as a function of mesoscale conditions. Copyright 2007 by the American Geophysical Union

    Mesoscale covariance of transport and CO2 fluxes: Evidence from observations and simulations using the WRF-VPRM coupled atmosphere-biosphere model

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    We developed a modeling system which combines a mesoscale meteorological model, the Weather Research and Forecasting (WRF) model, with a diagnostic biospheric model, the Vegetation Photosynthesis and Respiration (VPRM). The WRF-VPRM modeling system was designed to realistically simulate high-resolution atmospheric CO<sub>2</sub> concentration fields. In the system, WRF takes into account anthropogenic and biospheric CO<sub>2</sub> fluxes and realistic initial and boundary conditions for CO<sub>2</sub> from a global model. The system uses several “tagged” tracers for CO<sub>2</sub> fields from different sources. VPRM uses meteorological fields from WRF and high-resolution satellite indices to simulate biospheric CO<sub>2</sub> fluxes with realistic spatiotemporal patterns. Here we present results from the application of the model for interpretation of measurements made within the CarboEurope Regional Experiment Strategy (CERES). Simulated fields of meteorological variables and CO<sub>2</sub> were compared against ground-based and airborne observations. In particular, the characterization by aircraft measurements turned out to be crucial for the model evaluation. The comparison revealed that the model is able to capture the main observed features in the CO<sub>2</sub> distribution reasonably well. The simulations showed that daytime CO<sub>2</sub> measurements made at coastal stations can be strongly affected by land breeze and subsequent sea breeze transport of CO<sub>2</sub> respired from the vegetation during the previous night, which can lead to wrong estimates when such data are used in inverse studies. The results also show that WRF-VPRM is an effective modeling tool for addressing the near-field variability of CO<sub>2</sub> fluxes and concentrations for observing stations around the globe
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