Automatic control system for an oil-hydraulic actuator of a scissor lift

Lifting equipment’s have the purpose to lift goods within their safe working load and design rules specified in standards. However, some applications require additional care regarding handling the load when this care is out of the standard’s specifications. This paper presents the control and supervision system development of a scissor lift table, which should ensure, during its motion, that the vertical speed is constant. This lift table is working alongside a system for handling boxes composed by 3 entry conveyors and 1 exit conveyor. In this work, it was carried out the study of the direct and inverse kinematics to obtain the equations of position, speed and force for the oil-hydraulic actuator and the applicability of Denavit-Hartenberg’s algorithm for these equations. It was proposed a hydraulic circuit, with the selection of the main hydraulic components and the design of the oil-hydraulic actuator (a cylinder) with the magnetostrictive transducer as well. A programmable logical controller was selected, as well as the sensors and actuators for the conveyor system and a program was developed which allows to automatically control the system. The lift table’s velocity control is done by equations which define an oil flow profile of the hydraulic cylinder, which ensures a constant vertical speed of the lift table. To improve the control of the system, initial and final flow ramps were added to the equations, with reduced oil flow at the target height. It was observed that the use of Denavit-Hartenberg’s algorithm revealed to be limited, on which it was necessary to use other calculation methods to obtain the equations of speed and force. However, the proposed oil-hydraulic circuit, as well as the developed speed control, allow the control of the lift table’s position and speed.info:eu-repo/semantics/publishedVersio

Large-scale analysis of the SDSS-III DR8 photometric luminous galaxies angular correlation function

We analyse the large-scale angular correlation function (ACF) of the CMASS luminous galaxies (LGs), a photometric-redshift catalogue based on the Data Release 8 (DR8) of the Sloan Digital Sky Survey-III. This catalogue contains over $600 \, \, 000$ LGs in the range $0.45 \leq z \leq 0.65$, which was split into four redshift shells of constant width. First, we estimate the constraints on the redshift-space distortion (RSD) parameters $b\sigma_8$ and $f\sigma_8$, where $b$ is the galaxy bias, $f$ the growth rate and $\sigma_8$ is the normalization of the perturbations, finding that they vary appreciably among different redshift shells, in agreement with previous results using DR7 data. When assuming constant RSD parameters over the survey redshift range, we obtain $f\sigma_8 = 0.69 \pm 0.21$, which agrees at the $1.5\sigma$ level with Baryon Oscillation Spectroscopic Survey DR9 spectroscopic results. Next, we performed two cosmological analyses, where relevant parameters not fitted were kept fixed at their fiducial values. In the first analysis, we extracted the baryon acoustic oscillation peak position for the four redshift shells, and combined with the sound horizon scale from 7-year \textit{Wilkinson Microwave Anisotropy Probe} $(WMAP7)$ to produce the constraints $\Omega_{m}=0.249 \pm 0.031$ and $w=-0.885 \pm 0.145$. In the second analysis, we used the ACF full shape information to constrain cosmology using real data for the first time, finding $\Omega_{m} = 0.280 \pm 0.022$ and $f_b = \Omega_b/\Omega_m = 0.211 \pm 0.026$. These results are in good agreement with $WMAP7$ findings, showing that the ACF can be efficiently applied to constrain cosmology in future photometric galaxy surveys.Comment: MNRAS accepted. Minor corrections to match publish versio

Strong phenological differences between two populations of a Neotropical funnel-web wolf spider

Comparisons of phenological patterns among populations within a species are uncommon in arachnids. Aglaoctenus lagotis is a wolf spider that lives in funnel-webs across South America. The aim of this study was to describe the phenological patterns of two distant populations of A. lagotis (central Argentina, CA, and southern Uruguay, SU). Individuals of each population were sighted along transects, every month for two years. The CA and SU populations differed in their phenological patterns (Wald χ2 = 966.94, df = 66; p <0.001). The CA population showed a spring–summer unified reproductive season and immature individuals overwintered. SU showed the sexual period during autumn, the maternal period during spring–summer and the females, mostly mated, overwintered. These strong differences imply temporal isolation in mating possibilities between both populations. The differences encountered could be due to phenotypic plasticity or have a phylogenetic basis. Interpopulation studies of other features of A. lagotis would show whether they also vary, suggesting speciation.Fil: González Pérez, María de la Macarena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Cátedra de Diversidad Animal I; Argentina. Instituto de Investigaciones Biológicas "Clemente Estable"; UruguayFil: Costa, Fernando G.. Instituto de Investigaciones Biológicas "Clemente Estable"; UruguayFil: Peretti, Alfredo Vicente. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Cátedra de Diversidad Animal I; Argentin

Impacts of dielectric screening on the luminescence of monolayer WSe2_2

Single layers of transition metal dichalcogenides, such as WSe$_2$ have gathered increasing attention due to their intense electron-hole interactions, being considered promising candidates for developing novel optical applications. Within the few-layer regime, these systems become highly sensitive to the surrounding environment, enabling the possibility of using a proper substrate to tune desired aspects of these atomically-thin semiconductors. In this scenario, the dielectric environment provided by the substrates exerts significant influence on electronic and optical properties of these layered materials, affecting the electronic band-gap and the exciton binding energy. However, the corresponding effect on the luminescence of transition metal dichalcogenides is still under discussion. To elucidate these impacts, we used a broad set of materials as substrates for single-layers of WSe$_2$, enabling the observation of these effects over a wide range of electrical permittivities. Our results demonstrate that an increasing permittivity induces a systematic red-shift of the optical band-gap of WSe$_2$, intrinsically related to a considerable reduction of the luminescence intensity. Moreover, we annealed the samples to ensure a tight coupling between WSe$_2$and its substrates, reducing the effect of undesired adsorbates trapped in the interface. Ultimately, our findings reveal how critical the annealing temperature can be, indicating that above a certain threshold, the heating treatment can induce adverse impacts on the luminescence. Furthermore, our conclusions highlight the influence the dielectric properties of the substrate have on the luminescence of WSe$_2$, showing that a low electrical permittivity favours preserving the native properties of the adjacent monolayerComment: 16 pages, 8 figure

Co-exposure of the organic nanomaterial fullerene C60 with benzo[a]pyrene in Danio rerio (zebrafish) hepatocytes: Evidence of toxicological interactions

Compounds from the nanotechnology industry, such as carbon-based nanomaterials, are strong candidates to contaminate aquatic environments because their production and disposal have exponentially grown in a few years. Previous evidence shows that fullerene C60, a carbon nanomaterial, can facilitate the intake of metals or PAHs both in vivo and in vitro, potentially amplifying the deleterious effects of these toxicants in organisms. The present work aimed to investigate the effects of fullerene C60 in a Danio rerio (zebrafish) hepatocyte cell lineage exposed to benzo[a]pyrene (BaP) in terms of cell viability, oxidative stress parameters and BaP intracellular accumulation. Additionally, a computational docking was performed to investigate the interaction of the fullerene C60 molecule with the detoxificatory and antioxidant enzyme πGST. Fullerene C60 provoked a significant (p 0.05) alter the enzyme activity when added to GST purified extracts from the zebrafish hepatocyte cells. These results show that fullerene C60 can increase the intake of BaP into the cells, decreasing cell viability and impairing the detoxificatory response by phase II enzymes, such as GST, and this latter effect should be occurring at the transcriptional level.Fil: Ribas Ferreira, Josencler L.. Universidade Federal do Rio Grande do Sul; BrasilFil: Lonné, María Noelia. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: França, Thiago A.. Universidade Federal do Rio Grande do Sul; BrasilFil: Maximilla, Naiana R.. Universidade Federal do Rio Grande do Sul; BrasilFil: Lugokenski, Thiago H.. Universidade Federal de Santa Maria. Departamento de Química; BrasilFil: Costa, Patrícia G.. Universidade Federal do Rio Grande do Sul; BrasilFil: Fillmann, Gilberto. Universidade Federal do Rio Grande do Sul; BrasilFil: Soares, Félix A.. Universidade Federal de Santa Maria. Departamento de Química; BrasilFil: de la Torre, Fernando Roman. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Luján. Departamento de Ciencias Básicas; ArgentinaFil: Monserrat, José María. Universidade Federal do Rio Grande do Sul; Brasil. Instituto Nacional de Ciência e Tecnologia de Nanomateriais de Carbono; Brasi

Isothermal omega assisted alpha phase precipitation and microstructural evolution of an aged Ti-30Nb-3Fe alloy

The mechanical behavior of metastable β Ti alloys can be controlled through heat treatments. Thus, the relationship between the precipitation of α phase and the mechanical properties of these alloys is of special interest. In this work, the microstructure evolution of Ti-30Nb-3Fe alloy during aging heat treatments was evaluated using optical microscopy, scanning electron microscopy and X-ray diffraction. Moreover, Vickers hardness and elastic modulus were measured as a function of aging time. Finally, the ultimate strength and ductility of the alloy aged at 500 °C was assessed by tensile tests. In comparison to a Ti-30Nb alloy, the addition of Fe lowered the β-transus temperature, decreased the martensite start temperature to a value below room temperature, increased the precipitation temperature and reduced the dissolution temperature of ω phase, and lastly, decreased the α phase precipitation temperature. Low heating rates enabled isothermal ω phase precipitation and growth, providing favorable conditions for α phase precipitation and increasing the amount of α phase precipitates. Compared to the solution heat-treated and water-quenched condition, aging heat-treated Ti-30Nb-3Fe alloy presented higher Vickers hardness and mechanical strength, without significant loss of ductility233CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP405054/2016-588887.357955/2019-002016/24693-3The authors gratefully acknowledge the LNNano (National Nanotechnology Laboratory) at the CNPEM (National Center for Research on Energy and Materials) for allowing access to its SEM facilities. We also acknowledge the financial support of the Brazilian research funding agencies FAPESP (State of São Paulo Research Foundation) for Grant #2016/24693-3, CNPq (National Council for Scientific and Technological Development) for Grant #405054/2016-5, and CAPES/PNPD (Coordination for the Improvement of Higher Education Personnel) for Grant #88887.357955/2019-00. We thank the Brazilian Niobium Mining and Processing Company CBMM for supplying the Nb used in this stud

Ecological Footprint as a sustainability indicator to analyze energy consumption in a Portuguese textile facility

The main objective of this paper is to apply Ecological Footprint methodology as a tool to analyze the Portuguese textile industry. This analysis is related to energy and resources consumption in dyeing, printing and finishing processes. It also includes identification of mitigation measures to increase energy efficiency, promoting at the same time the reduction of CO2 emissions and consequently the decrease in industry's Ecological Footprint. Moreover, the analysis presents the Ecological Footprint reduction potential for each mitigation option proposed for an important textile facility located in the North Region of Portugal, used as a case study in this work. The results for the case study showed that the total Ecological Footprint accounted, for the year 2016, summed up to 4890 gha. Furthermore, the energy category corresponds to more than 50% of the total Ecological Footprint estimation, and natural gas was the most required fuel for the processes. The calculation of the Ecological Footprint in the textile facilities can be used as a tool to analyze the processes' energy efficiency and to quantify the global impact of the implementation of mitigation measures in the energy field. The result is an indicator shown in a common unit, gha (global hectare) and it can be easily used to compare energy-intensive processes and industrial sectors. In addition, it can be used to analyze how each sector can impact the country's total demand for resources