Latest Articles

Open AccessArticle
Spectro-Temporal Heterogeneity Measures from Dense High Spatial Resolution Satellite Image Time Series: Application to Grassland Species Diversity Estimation
Remote Sens. 2017, 9(10), 993; doi:10.3390/rs9100993 (registering DOI) -
Abstract
Grasslands represent a significant source of biodiversity that is important to monitor over large extents. The Spectral Variation Hypothesis (SVH) assumes that the Spectral Heterogeneity (SH) measured from remote sensing data can be used as a proxy for species diversity. Here, we argue
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Grasslands represent a significant source of biodiversity that is important to monitor over large extents. The Spectral Variation Hypothesis (SVH) assumes that the Spectral Heterogeneity (SH) measured from remote sensing data can be used as a proxy for species diversity. Here, we argue the hypothesis that the grassland’s species differ in their phenology and, hence, that the temporal variations can be used in addition to the spectral variations. The purpose of this study is to attempt verifying the SVH in grasslands using the temporal information provided by dense Satellite Image Time Series (SITS) with a high spatial resolution. Our method to assess the spectro-temporal heterogeneity is based on a clustering of grasslands using a robust technique for high dimensional data. We propose new SH measures derived from this clustering and computed at the grassland level. We compare them to the Mean Distance to Centroid (MDC). The method is experimented on 192 grasslands from southwest France using an intra-annual multispectral SPOT5 SITS comprising 18 images and using single images from this SITS. The combination of two of the proposed SH measures—the within-class variability and the entropy—in a multivariate linear model explained the variance of the grasslands’ Shannon index more than the MDC. However, there were no significant differences between the predicted values issued from the best models using multitemporal and monotemporal imagery. We conclude that multitemporal data at a spatial resolution of 10 m do not contribute to estimating the species diversity. The temporal variations may be more related to the effect of management practices. Full article
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Open AccessArticle
Trajectory Optimization of Electrostatic Spray Painting Robots on Curved Surface
Coatings 2017, 7(10), 155; doi:10.3390/coatings7100155 (registering DOI) -
Abstract
In this paper, a new practical electrostatic rotating bell (ESRB) cumulative rate model of painting is derived, and an experimental study on painting is carried out. First, the experimental method is used to obtain the radial thickness profile function of the spatial paint
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In this paper, a new practical electrostatic rotating bell (ESRB) cumulative rate model of painting is derived, and an experimental study on painting is carried out. First, the experimental method is used to obtain the radial thickness profile function of the spatial paint distribution of static spray. Then, a spatial trajectory-planning scheme for a spray-painting robot based on a rectangular model is presented. This method designs the spatial path of the spray-painting robot by using the cuboid model method after the optimal value is taken as the width d of the overlapping area of the two spray-painting strokes in the plane. The experimental results illustrate that the paint thickness basically meets the requirements, and the experimental results verify the effectiveness of the trajectory optimization method. Full article
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Open AccessArticle
An Improved Flexible Solar Thermal Energy Integration Process for Enhancing the Coal-Based Energy Efficiency and NOx Removal Effectiveness in Coal-Fired Power Plants under Different Load Conditions
Energies 2017, 10(10), 1485; doi:10.3390/en10101485 (registering DOI) -
Abstract
An improved flexible solar-aided power generation system (SAPG) for enhancing both selective catalytic reduction (SCR) de-NOx efficiency and coal-based energy efficiency of coal-fired power plants is proposed. In the proposed concept, the solar energy injection point is changed for different power plant
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An improved flexible solar-aided power generation system (SAPG) for enhancing both selective catalytic reduction (SCR) de-NOx efficiency and coal-based energy efficiency of coal-fired power plants is proposed. In the proposed concept, the solar energy injection point is changed for different power plant loads, bringing about different benefits for coal-fired power generation. For partial/low load, solar energy is beneficially used to increase the flue gas temperature to guarantee the SCR de-NOx effectiveness as well as increase the boiler energy input by reheating the combustion air. For high power load, solar energy is used for saving steam bleeds from turbines by heating the feed water. A case study for a typical 1000 MW coal-fired power plant using the proposed concept has been performed and the results showed that, the SCR de-NOx efficiency of proposed SAPG could increase by 3.1% and 7.9% under medium load and low load conditions, respectively, as compared with the reference plant. The standard coal consumption rate of the proposed SAPG could decrease by 2.68 g/kWh, 4.05 g/kWh and 6.31 g/kWh for high, medium and low loads, respectively, with 0.040 USD/kWh of solar generated electricity cost. The proposed concept opens up a novel solar energy integration pattern in coal-fired power plants to improve the pollutant removal effectiveness and decrease the coal consumption of the power plant. Full article
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Open AccessArticle
A Rigorously-Weighted Spatiotemporal Fusion Model with Uncertainty Analysis
Remote Sens. 2017, 9(10), 990; doi:10.3390/rs9100990 (registering DOI) -
Abstract
Interest has been growing with regard to the use of remote sensing data characterized by a fine spatial resolution and frequent coverage for the monitoring of land surface dynamics. However, current satellite sensors are fundamentally limited by a trade-off between their spatial and
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Interest has been growing with regard to the use of remote sensing data characterized by a fine spatial resolution and frequent coverage for the monitoring of land surface dynamics. However, current satellite sensors are fundamentally limited by a trade-off between their spatial and temporal resolutions. Spatiotemporal fusion thus provides a feasible solution to overcome this limitation, and many blending algorithms have been developed. Among them, the popular spatial and temporal adaptive reflectance fusion model (STARFM) is based on a weighted function; however, it uses an ad hoc approach to estimate the weights of surrounding similar pixels. Additionally, an uncertainty analysis of the predicted result is not provided in the STARFM or any other fusion algorithm. This paper proposes a rigorously-weighted spatiotemporal fusion model (RWSTFM) based on geostatistics to blend the surface reflectances of Moderate Resolution Imaging Spectroradiometer (MODIS) and Landsat-5 Thematic Mapper (TM) imagery. The RWSTFM, which is based on ordinary kriging, derives the weights in terms of a fitted semivariance-distance relationship and calculates the estimation variance, which is a measure of the prediction uncertainty. The RWSTFM was tested using three datasets and compared with two commonly-used spatiotemporal reflectance fusion algorithms: the STARFM and the flexible spatiotemporal data fusion (FSDAF) method. The fusion results show that the proposed RWSTFM consistently outperformed the other algorithms both visually and quantitatively. Additionally, more than 70% of the squared error was accounted for by the estimation variance of the RWSTFM for all three of the datasets. Full article
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Open AccessArticle
Reframing Catholic Theological Ethics: Summary and Application
Religions 2017, 8(10), 203; doi:10.3390/rel8100203 (registering DOI) -
Abstract
This text represents a summary of the major points developed in the book, Reframing Catholic Theological Ethics, and a brief overview of how the author understands the relation between religion, ethics, and the building of a virtuous community. The main points of the
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This text represents a summary of the major points developed in the book, Reframing Catholic Theological Ethics, and a brief overview of how the author understands the relation between religion, ethics, and the building of a virtuous community. The main points of the book involve the anatomy of “the moral event” that includes a breakdown of all the elements necessary to consider before one arrives at ethical judgments and decision-making. Foundations are brought forth for these elements, each of which exhibits its own characteristics. The good and evil details of actions and circumstances that make up behavior are based upon an analysis of what is beneficial or harmful to human persons, integrally and adequately considered. Behaviors themselves are considered right or wrong in relation to whether they are appropriate ways of achieving one’s intended ends. Then, the distinction between good and bad is related to one’s virtuous or vicious dispositions, which necessitates a revised understanding of virtue. Based upon a view of religion that provides a formulation of principles that guide the life of the believing community, it is suggested that these principles encourage a commitment to ends or goals that serve the maintenance and advance of a community’s ethics. Full article
Open AccessArticle
Investigation of the Microstructure Evolution in a Fe-17Mn-1.5Al-0.3C Steel via In Situ Synchrotron X-ray Diffraction during a Tensile Test
Materials 2017, 10(10), 1129; doi:10.3390/ma10101129 (registering DOI) -
Abstract
The quantitative characterization of the microstructure evolution in high-Mn steel during deformation is of great importance to understanding its strain-hardening behavior. In the current study, in situ high-energy synchrotron X-ray diffraction was employed to characterize the microstructure evolution in a Fe-17Mn-1.5Al-0.3C steel during
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The quantitative characterization of the microstructure evolution in high-Mn steel during deformation is of great importance to understanding its strain-hardening behavior. In the current study, in situ high-energy synchrotron X-ray diffraction was employed to characterize the microstructure evolution in a Fe-17Mn-1.5Al-0.3C steel during a tensile test. The microstructure at different engineering strain levels—in terms of ε-martensite and α’-martensite volume fractions, the stacking fault probability, and the twin fault probability—was analyzed by the Rietveld refinement method. The Fe-17Mn-1.5Al-0.3C steel exhibits a high ultimate tensile strength with a superior uniform elongation and a high strain-hardening rate. The remaining high strain-hardening rate at the strain level about 0.025 to 0.35 results from ε-martensite dominant transformation-induced-plasticity (TRIP) effect. The increase in the strain-hardening rate at the strain level around 0.35 to 0.43 is attributed to the synergetic α’-martensite dominant TRIP and twinning-induced-plasticity (TWIP) effects. An evaluation of the stacking fault energy (SFE) of the Fe-17Mn-1.5Al-0.3C steel by the synchrotron measurements shows good agreement with the thermodynamic calculation of the SFE. Full article
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Open AccessReview
Diverse Phytochemicals and Bioactivities in the Ancient Fruit and Modern Functional Food Pomegranate (Punica granatum)
Molecules 2017, 22(10), 1606; doi:10.3390/molecules22101606 (registering DOI) -
Abstract
Having served as a symbolic fruit since ancient times, pomegranate (Punica granatum) has also gained considerable recognition as a functional food in the modern era. A large body of literature has linked pomegranate polyphenols, particularly anthocyanins (ATs) and hydrolyzable tannins (HTs),
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Having served as a symbolic fruit since ancient times, pomegranate (Punica granatum) has also gained considerable recognition as a functional food in the modern era. A large body of literature has linked pomegranate polyphenols, particularly anthocyanins (ATs) and hydrolyzable tannins (HTs), to the health-promoting activities of pomegranate juice and fruit extracts. However, it remains unclear as to how, and to what extent, the numerous phytochemicals in pomegranate may interact and exert cooperative activities in humans. In this review, we examine the structural and analytical information of the diverse phytochemicals that have been identified in different pomegranate tissues, to establish a knowledge base for characterization of metabolite profiles, discovery of novel phytochemicals, and investigation of phytochemical interactions in pomegranate. We also assess recent findings on the function and molecular mechanism of ATs as well as urolithins, the intestinal microbial derivatives of pomegranate HTs, on human nutrition and health. A better understanding of the structural diversity of pomegranate phytochemicals as well as their bioconversions and bioactivities in humans will facilitate the interrogation of their synergistic/antagonistic interactions and accelerate their applications in dietary-based cancer chemoprevention and treatment in the future. Full article
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Open AccessFeature PaperArticle
Formation of Light-Weight Ferroalloys in the Fe2O3-Al2O3-C System at 1550 °C: Influence of Silica Impurities
Metals 2017, 7(10), 391; doi:10.3390/met7100391 (registering DOI) -
Abstract
Light-weight ferro-aluminium alloys are finding increasing application in the transport sector to reduce overall weights, energy costs and CO2 emissions. As the primary production processes of both Fe and Al are among the most energy-intensive industrial processes in the world, there is
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Light-weight ferro-aluminium alloys are finding increasing application in the transport sector to reduce overall weights, energy costs and CO2 emissions. As the primary production processes of both Fe and Al are among the most energy-intensive industrial processes in the world, there is an urgent need to develop alternate routes for producing Fe-Al alloys. Our group has successfully produced these alloys in the Fe2O3-Al2O3-C system by producing molten iron in situ, followed by the reduction of alumina at 1550 °C and pick-up of Al by Fe. In this article, we report on the influence of silica, a typical impurity present in iron oxide and reductant carbon, on the reduction reactions in this system, and on the formation of ferroalloys. In-depth investigations were carried out on the Fe2O3-SiO2-C and Fe2O3-Al2O3-SiO2-C systems at 1550 °C for times of up to 60 min. Detailed HRSEM/EDS and XRD analysis was carried on the quenched reaction products recovered after various heat treatments. A complete reduction of silica and alumina was observed in the Fe2O3-SiO2-C system, along with the formation of FeSi and SiC. The reduction reactions were relatively slow in the Fe2O3-Al2O3-SiO2-C system. While the formation of SiC, FeSi and mullite (Al6Si2O13) was observed, even small amounts of Fe-Al alloys could not be detected. The presence of silica impurities reduced the formation of Fe-Al to negligible levels by depleting molten iron from the reaction zone, a key ingredient for the low-temperature carbothermic reduction of alumina. This study shows that some impurities can be highly detrimental to the reaction kinetics and the formation of ferroalloys, and great care needs to be exercised during the choice of reaction constituents. Full article
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Open AccessFeature PaperArticle
Toughening of Epoxy Adhesives by Combined Interaction of Carbon Nanotubes and Silsesquioxanes
Materials 2017, 10(10), 1131; doi:10.3390/ma10101131 (registering DOI) -
Abstract
The extensive use of adhesives in many structural applications in the transport industry and particularly in the aeronautic field is due to numerous advantages of bonded joints. However, still many researchers are working to enhance the mechanical properties and rheological performance of adhesives
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The extensive use of adhesives in many structural applications in the transport industry and particularly in the aeronautic field is due to numerous advantages of bonded joints. However, still many researchers are working to enhance the mechanical properties and rheological performance of adhesives by using nanoadditives. In this study the effect of the addition of Multi-Wall Carbon Nanotubes (MWCNTs) with Polyhedral Oligomeric Silsesquioxane (POSS) compounds, either Glycidyl Oligomeric Silsesquioxanes (GPOSS) or DodecaPhenyl Oligomeric Silsesquioxanes (DPHPOSS) to Tetraglycidyl Methylene Dianiline (TGMDA) epoxy formulation, was investigated. The formulations contain neither a tougher matrix such as elastomers nor other additives typically used to provide a closer match in the coefficient of thermal expansion in order to discriminate only the effect of the addition of the above-mentioned components. Bonded aluminium single lap joints were made using both untreated and Chromic Acid Anodisation (CAA)-treated aluminium alloy T2024 adherends. The effects of the different chemical functionalities of POSS compounds, as well as the synergistic effect between the MWCNT and POSS combination on adhesion strength, were evaluated by viscosity measurement, tensile tests, Dynamic Mechanical Analysis (DMA), single lap joint shear strength tests, and morphological investigation. The best performance in the Lap Shear Strength (LSS) of the manufactured joints has been found for treated adherends bonded with epoxy adhesive containing MWCNTs and GPOSS. Carbon nanotubes have been found to play a very effective bridging function across the fracture surface of the bonded joints. Full article
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