In computer vision applications one of important step, when the aim of the system is to obtain a measurement result, is the uncertainty of measurement evaluation. Involving image processing and analysis for measuremen...
In computer vision applications one of important step, when the aim of the system is to obtain a measurement result, is the uncertainty of measurement evaluation. Involving image processing and analysis for measurement requires a specific study of all input quantities and its contribution for expanded uncertainty. In this paper will be described all contributions and how each one affect the measurement result, including contributions from algorithms of image processing. Finally this work compares the uncertainty obtained with a previous result from Monte Carlo simulation for analysis validation.
This work presents the preparation of modified titanates nanotubes with tetraethyl orthosilicate (TNT-TEOS) and their use in the synthesis of TNT-TEOS/polyurethane nanocomposite by in situ polymerization. The filler w...
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The objective of this study was to identify the perspectives and factors affecting management performance of companies in horizontal networks. The instrument used for the selection of articles was Proknow C-structured...
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PV Grid-connected inverters must fulfill the standards specifications of current harmonics injected to the grid. In order to satisfy these grid requirements, passive filters are connected between the inverter and the ...
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PV Grid-connected inverters must fulfill the standards specifications of current harmonics injected to the grid. In order to satisfy these grid requirements, passive filters are connected between the inverter and the grid. This paper compares the response characteristic of the traditional inductive (L) filter with the inductive-capacitive-inductive (LCL) filter. It is shown that the increasing the inductance L leads to a good ripple current suppression around the inverter switch frequency. The LCL filter provides better harmonic attenuation and reduces the filter size. The main drawback is the LCL filter impedance, which is characterized by a typical resonance peak, which has to be damped to avoid instability. Passive or active techniques can be used to damp the LCL resonance. To address this issue, this paper presents a comparison of passive and active damping strategies. Experimental results are given to support the theoretical analysis and to illustrate the performance of grid connected PV inverter system.
The LCL filter is one of the most used filters in grid connected distributed generation. It is mainly due to its efficiency and reduced physical size when compared to a typical L filter. However, the LCL filter has an...
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The LCL filter is one of the most used filters in grid connected distributed generation. It is mainly due to its efficiency and reduced physical size when compared to a typical L filter. However, the LCL filter has an inherent resonance frequency that can lead the system to instability or power quality degradation. The converter or the grid current can be used as controlled variable in the current controller. Based in this context, this paper analyzes the stability and studies the control issues brought by the dynamics of the LCL filter. A comparative analysis of the results provided by the use of different controlled variable in the current controller is presented. An evaluation of PI and PD control is done to verify which one is the better option to be used in the current control. A theoretical analysis is carried out based in the pole-zero map of the system, Bode diagrams and numerical simulation.
The Body Appreciation Scale-2 (BAS-2) is a widely used measure of a core facet of the positive body image construct. However, extant research concerning measurement invariance of the BAS-2 across a large number of nat...
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The Body Appreciation Scale-2 (BAS-2) is a widely used measure of a core facet of the positive body image construct. However, extant research concerning measurement invariance of the BAS-2 across a large number of nations remains limited. Here, we utilised the Body Image in Nature (BINS) dataset - with data collected between 2020 and 2022 - to assess measurement invariance of the BAS-2 across 65 nations, 40 languages, gender identities, and age groups. Multi-group confirmatory factor analysis indicated that full scalar invariance was upheld across all nations, languages, gender identities, and age groups, suggesting that the unidimensional BAS-2 model has widespread applicability. There were large differences across nations and languages in latent body appreciation, while differences across gender identities and age groups were negligible-to-small. Additionally, greater body appreciation was significantly associated with higher life satisfaction, being single (versus being married or in a committed relationship), and greater rurality (versus urbanicity). Across a subset of nations where nation-level data were available, greater body appreciation was also significantly associated with greater cultural distance from the United States and greater relative income inequality. These findings suggest that the BAS-2 likely captures a near-universal conceptualisation of the body appreciation construct, which should facilitate further cross-cultural research.
In this work, the joint photocatalytical and bactericidal potential, under UV radiation, of titania and silver nano powders dispersed in PMMA and deposited on porous ceramic substrates (40 and 80 ppi) by dip- and spra...
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In this work, the joint photocatalytical and bactericidal potential, under UV radiation, of titania and silver nano powders dispersed in PMMA and deposited on porous ceramic substrates (40 and 80 ppi) by dip- and spray-coating, were investigated in low power consumption water purification reactors, using the Escherichia coli (E. coli) as reference pathogen. The results show the effect of different reactor morphologies (porosity, permeability, mechanical strength) on the bactericidal efficiency.
This paper shows an analysis of the interaction of the electromagnetic field generated by a tablet with three different models of human heads: a homogeneous model Specific Anthropomorphic Mannequin (SAM) and two heter...
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The term crystal structure is understood as a set of atoms periodically distributed in space, forming a lattice. The composite material, bone, contains an organic part consisted of collagen and an inorganic part consi...
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The term crystal structure is understood as a set of atoms periodically distributed in space, forming a lattice. The composite material, bone, contains an organic part consisted of collagen and an inorganic part consisted predominantly of hydroxyapatite crystals, having the molecular formula Ca 10 (PO4) 6 (OH) 2 in its unit cell. The crystal structure of hydroxyapatite can indicate the trabecular bone quality, by the identification of crystallite size, microhardness, microstrain and ratio of calcium and phosphorus in bones of three types: normal, osteopenic or osteoporotic. Osteoporosis is defined by the National Institute of Health as a skeletal disorder characterized by compromised bone strength and increased risk of fracture. Dried trabecular bones of vertebrae L1 columns of nine human cadavers from the São Paulo City Morgue were used. Before sample collection, they were pre-divided into three groups: normal, osteopenic or osteoporotic, through quantitative ultrasound of the calcaneus. The characterization of the three types of bones was made by electron microscopy scanning, microanalysis by energy dispersive spectrometry, microhardness and powder X-ray diffraction with application of the Rietveld method. The results showed a decrease of the crystallite size, hardness, ratio of calcium and phosphorus, trabecular number and bone density and an increase in microstrain values suggesting greater fragility and disruption in the crystalline structure of hydroxyapatite in osteopenic and osteoporotic bone. Microstructural characterization of hydroxyapatite crystals in dry trabecular bone could differentiate the three types of bones (normal, osteopenic and osteoporotic) and supplement assessment of osteoporosis, with an emphasis on bone quality.
This paper presents a design methodology for a first order L filter inductance used to connect a three-phase power converter to the grid. This method uses the desired THD_i to calculate the L filter inductance to ensu...
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ISBN:
(纸本)9781479987801
This paper presents a design methodology for a first order L filter inductance used to connect a three-phase power converter to the grid. This method uses the desired THD_i to calculate the L filter inductance to ensure the grid-connection standards are met. This methodology was designed for converters operating with Space Vector PWM modulation.
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