bluuebunny/crossref_metadata_2025 huggingface dataset:
Nisin Influence on the Antimicrobial Resistance Ability of Canine Oral Enterococci
Authors: Cunha Eva , Janela Rita , Costa Margarida , Tavares Luís , Veiga Ana Salomé , Oliveira Manuela
Published: December 2020

Periodontal disease (PD) is one of the most common diseases in dogs. Although previous studies have shown the potential of the antimicrobial peptide nisin for PD control, there is no information regarding its influence in the development of antimicrobial resistance or horizontal gene transfer (HGT). Nisin’s mutant prevention concentration (MPC) and selection window (MSW) were determined for a collection of canine oral enterococci. Isolates recovered after the determination of the MPC values were characterized for their antimicrobial profile and its nisin minimum inhibitory and bactericidal concentrations. The potential of vanA HGT between Enterococcus faecium CCGU36804 and nine clinical canine staphylococci and enterococci was evaluated. Nisin MPC values ranged from 400 to more than 600 μg/mL. In comparison with the original enterococci collection, the isolates recovered after the determination of the nisin MPC showed increased resistance towards amoxicillin/clavulanate (5%), vancomycin (5%), enrofloxacin (10%), gentamicin (10%) and imipenem (15%). The HGT of vanA gene was not observed. This work showed that nisin selective pressure may induce changes in the bacteria’s antimicrobial resistance profile but does not influence horizontal transfer of vanA gene. To our knowledge, this is the first report of nisin’s MPC and MSW determination regarding canine enterococci.
Impact of Enzymatic and Microbial Bioprocessing on Antioxidant Properties of Hemp (Cannabis sativa L.)
Authors: Pontonio Erica , Verni Michela , Dingeo Cinzia , Diaz-de-Cerio Elixabet , Pinto Daniela , Rizzello Carlo Giuseppe
Published: December 2020

Although the hemp seed boasts high nutritional and functional potential, its use in food preparations is still underestimated due to scarce technological properties and the presence of several anti-nutritional factors. Here, an optimization of a biotechnological protocol aimed at improving the antioxidant properties and the protein digestibility of the whole hemp seed has been proposed. Processing based on the use of commercial food grade enzymes and ad hoc selected lactic acid bacteria was tested and the phenolic and protein profiles were investigated through an integrated approach including selective extraction, purification, and identification of the potentially active compounds. The influence of the bioprocessing on the antioxidant activity of the hemp was evaluated both in vitro and on human keratinocytes. The lactic acid bacteria fermentation was the best method to significantly improve the antioxidant potential of the hemp through intense proteolysis which led to both the release of bioactive peptides and the increase in the protein digestibility. Moreover, changes in the phenolic profile allowed a significant protective effect against oxidative stress measured on the human keratinocyte cell line.
Therapeutic Effects of Specialized Pro-Resolving Lipids Mediators on Cardiac Fibrosis via NRF2 Activation
Authors: Kang Gyeoung Jin , Kim Eun Ji , Lee Chang Hoon
Published: December 2020

Heart disease is the number one mortality disease in the world. In particular, cardiac fibrosis is considered as a major factor causing myocardial infarction and heart failure. In particular, oxidative stress is a major cause of heart fibrosis. In order to control such oxidative stress, the importance of nuclear factor erythropoietin 2 related factor 2 (NRF2) has recently been highlighted. In this review, we will discuss the activation of NRF2 by docosahexanoic acid (DHA), eicosapentaenoic acid (EPA), and the specialized pro-resolving lipid mediators (SPMs) derived from polyunsaturated lipids, including DHA and EPA. Additionally, we will discuss their effects on cardiac fibrosis via NRF2 activation.
Adaptive Task-Space Manipulator Control with Parametric Uncertainties in Kinematics and Dynamics
Authors: Yih Chih-Chen , Wu Shih-Jeh
Published: December 2020

This paper aims to deal with the problem of robot tracking control in the presence of parametric uncertainties in kinematics and dynamics. We propose a simple and effective adaptive control scheme that includes adaptation laws for unknown constant kinematic and dynamic parameters. In addition, instead of convolution-type filtered differentiation, we designed a new observer to estimate velocity in the task space, and the proposed adaptive control requires no acceleration measurement in the joint space. Using the Lyapunov stability and Barbalat’s lemma, we show that by appropriately choosing design parameters, the tracking errors and estimation errors in task space can asymptotically converge to zero. Through numerical simulation on a two-link robot with a fixed camera, we illustrate the design procedures and demonstrate the feasibility of the proposed adaptive control scheme for the trajectory tracking of robot manipulators.
Duty Factor Reflects Lower Limb Kinematics of Running
Authors: Patoz Aurélien , Lussiana Thibault , Thouvenot Adrien , Mourot Laurent , Gindre Cyrille
Published: December 2020

The aim was to identify the differences in lower limb kinematics used by high (DFhigh) and low (DFlow) duty factor (DF) runners, particularly their sagittal plane (hip, knee, and ankle) joint angles and pelvis and foot segment angles during stance. Fifty-nine runners were divided in two DF groups based on their mean DF measured across a range of speeds. Temporal characteristics and whole-body three-dimensional kinematics of the running step were recorded from treadmill runs at 8, 10, 12, 14, 16, and 18 km/h. Across speeds, DFhigh runners, which limit vertical displacement of the COM and promote forward propulsion, exhibited more lower limb flexion than DFlow during the ground contact time and were rearfoot strikers. On the contrary, DFlow runners used a more extended lower limb than DFhigh due to a stiffer leg and were midfoot and forefoot strikers. Therefore, two different lower limb kinematic mechanisms are involved in running and the one of an individual is reflected by the DF.
Iterative Signal Detection Scheme Using Multilayer Perceptron for a Bit-Patterned Media Recording System
Authors: Jeong Seongkwon , Lee Jaejin
Published: December 2020

Because of the physical and engineering problems of conventional magnetic data storage systems, bit-patterned media recording (BPMR) is expected to be a promising technology for extending the storage density to beyond 1 Tb /in2. To increase the storage density in BPMR systems, the separation between islands in both down- and cross-track directions must be reduced; this reduction results in two-dimensional interference from neighboring symbols in those directions, which is a major performance degradation factor in BPMR. Herein, we propose an iterative signal detection scheme between a Viterbi detector and a multilayer perceptron to improve the performance of a BPMR system. In the proposed signal detection scheme, we use the modified output of a multilayer perceptron as a priori information to improve equalization and extrinsic information to decrease the effect of intertrack interference.
Energy Consumption Comparison of a Single Variable-Speed Pump and a System of Two Pumps: Variable-Speed and Fixed-Speed
Authors: Oshurbekov Safarbek , Kazakbaev Vadim , Prakht Vladimir , Dmitrievskii Vladimir , Gevorkov Levon
Published: December 2020

The energy efficiency of a multi-pump system consisting of two low-power (0.75 kW) pumps operating in parallel mode and a single-pump mechanism (1.5 kW) is compared in this study. For this purpose, mathematical models, experimental data, and data retrieved from the manuals provided by the pump manufacturers are used. The single-pump system is fed by a single variable speed drive. A multi-pump system running in parallel mode consists of two pumps. One of them is driven by an induction motor connected directly to the electrical grid and equipped with a throttle. Another pump is actuated by an induction motor fed by a variable speed drive. The flowrate of the liquid in the multi-pump is controlled with the help of speed variation and throttling. In the case of the single-pump system the conventional speed control method is applied during the analysis. For both pump system topologies, the daily and annual energy consumption is obtained. As a result of conducted calculations, it was shown that the multi-pump provides 29.8% savings in comparison to the single-pump system in the case of a typical flowrate profile.
Balancing Workload and Workforce Capacity in Lean Management: Application to Multi-Model Assembly Lines
Authors: Fortuny-Santos Jordi , Ruiz-de-Arbulo-López Patxi , Cuatrecasas-Arbós Lluís , Fortuny-Profitós Jordi
Published: December 2020

While multi-model assembly lines are used by advanced lean companies because of their flexibility (different models of a product are produced in small lots and reach the customers in a short lead time), most of the extant literature on how to staff assembly lines focuses either on single-model lines or on mixed-model lines. The literature on multi-model lines is scarce and results given by current methods may be of limited applicability. In consequence, we develop a procedure to staff multi-model assembly lines while taking into account the principles of lean manufacturing. As a first approach, we replace the concepts of operation time and desired cycle time by their reciprocal magnitudes workload and capacity, and we define the dimensionless term of unit workload (load/capacity ratio) in order to avoid magnitudes related to time such as cycle time because, in practice, they might not be known. Next, we develop the necessary equations to apply this framework to a multi-model line. Finally, a piece of software in Python is developed, taking advantage of Google’s OR-Tools solver, to achieve an optimal multi-model line with a constant workforce and with each workstation performing the same tasks across all models. Several instances are tested to ensure the performance of this method.
Effect of Uncertainties in Material and Structural Detailing on the Seismic Vulnerability of RC Frames Considering Construction Quality Defects
Authors: Kim Siyun , Moon Taehwan , Kim Sung Jig
Published: December 2020

This paper evaluates the effect of construction quality defects on the seismic vulnerability of reinforced concrete (RC) frames. The variability in the construction quality of material properties and structural detailing is considered to assess the effect on the seismic behavior of RC frames. Concrete strength and yield strength of the reinforcement are selected as uncertain variables for the material properties, while the variabilities in the longitudinal reinforcement ratio and the volumetric ratio of transverse reinforcement are employed for structural detailing. Taking into account the selected construction quality uncertainties, the sensitivity analysis of the seismic vulnerability of the RC frames is performed and the impact of significant parameters is assessed at the global and local levels. This extensive analytical study reveals that the seismic vulnerability of the selected RC frame is particularly sensitive to concrete strength and the volumetric ratio of transverse reinforcement.
Modelling, Design and Validation of Spatially Resolved Reflectance Based Fiber Optic Probe for Epithelial Precancer Diagnostics
Authors: Singh Pankaj , Pandey Prabodh , Shukla Shivam , Naik Naren , Pradhan Asima
Published: December 2020

Fiber-optic probes are imperative for in-vivo diagnosis of cancer. Depending on the access to a diseased organ and the mutations one aims to sense, the probe designs vary. We carry out a detailed numerical study of the efficacy of the common probe geometries for epithelial cancer characterization based on spatially resolved reflectance data. As per the outcomes of this comparative study, a probe has been manufactured and using Monte Carlo look up table based inversion scheme, the absorption and scattering coefficients of the epithelium mimicking top layer have been recovered from noisy synthetic as well as experimental data.
On Mathematical Modelling of Automated Coverage Optimization in Wireless 5G and beyond Deployments
Authors: Seda Pavel , Seda Milos , Hosek Jiri
Published: December 2020

The need to optimize the deployment and maintenance costs for service delivery in wireless networks is an essential task for each service provider. The goal of this paper was to optimize the number of service centres (gNodeB) to cover selected customer locations based on the given requirements. This optimization need is especially emerging in emerging 5G and beyond cellular systems that are characterized by a large number of simultaneously connected devices, which is typically difficult to handle by the existing wireless systems. Currently, the network infrastructure planning tools used in the industry include Atoll Radio Planning Tool, RadioPlanner and others. These tools do not provide an automatic selection of a deployment position for specific gNodeB nodes in a given area with defined requirements. To design a network with those tools, a great deal of manual tasks that could be reduced by more sophisticated solutions are required. For that reason, our goal here and our main contribution of this paper were the development of new mathematical models that fit the currently emerging scenarios of wireless network deployment and maintenance. Next, we also provide the design and implementation of a verification methodology for these models through provided simulations. For the performance evaluation of the models, we utilize test datasets and discuss a case study scenario from a selected district in Central Europe.
Comparison of Urban Heat Island Intensity Estimation Methods Using Urbanized WRF in Berlin, Germany
Authors: Vogel Julian , Afshari Afshin
Published: December 2020

In this study, we present a meso-scale simulation of the urban microclimate in Berlin, Germany, using the Weather Research and Forecasting (WRF) numerical weather prediction platform. The objective of the study is to derive an accurate estimate of the near-surface urban heat island (UHI) intensity. The simulation is conducted over a two-week summer period. We compare different physical schemes, different urban canopy schemes and different methods for estimating the UHI intensity. The urban fraction of each urban category is derived using the Copernicus Impervious Density data and the Corine Land Cover data. High-resolution City Geography Markup Language (CityGML) data is used to estimate the building height densities required by the multi-layer urban canopy model (UCM). Within the single-layer UCM, we implement an anthropogenic heat profile based on the large scale urban consumption of energy (LUCY) model. The optimal model configuration combines the WRF Single Moment Five-Class (WSM5) microphysics scheme, the Bougeault–Lacarrère planetary boundary layer scheme, the eta similarity (Mellor–Yamada–Janjic) surface layer scheme, the Noah Multi-Parameterization land surface model, the Dudhia and Rapid Radiative Transfer Model (RRTM) radiation schemes, and the multi-layer UCM (including the building energy model). Our simulated UHI intensity results agree well with measurements with a root mean squared error of 0.86K and a mean bias error of 0.20K. After model validation, we proceed to compare several UHI intensity calculation methods, including the ‘ring rural reference’ (RRR) method and the ‘virtual rural reference’ (VRR) method. The VRR mthod is also known as the ‘urban increment’ method. We suggest and argument that the VRR approach is superior.
Antibacterial Effect of Aluminum Surfaces Untreated and Treated with a Special Anodizing Based on Titanium Oxide Approved for Food Contact
Authors: Di Cerbo Alessandro , Mescola Andrea , Iseppi Ramona , Canton Roberto , Rossi Giacomo , Stocchi Roberta , Loschi Anna Rita , Alessandrini Andrea , Rea Stefano , Sabia Carla
Published: December 2020

One of the main concerns of the food industry is microbial adhesion to food contact surfaces and consequent contamination. We evaluated the potential bacteriostatic/bactericidal efficacy of aluminum surfaces with different large-scale roughness (0.25, 0.5 and 1 μm) before and after the surface treatment with a special anodizing based on titanium oxide nanotechnology (DURALTI®) and after 3 different sanitizing treatments, e.g., UV, alcohol and a natural product named Gold lotion. Four Gram-negative (Escherichia coli ATCC 25922, Salmonella typhimurium ATCC 1402, Yersinia enterocolitica ATCC 9610 and Pseudomonas aeruginosa ATCC 27588) and four Gram-positive (Staphylococcus aureus ATCC 6538, Enterococcus faecalis ATCC 29212, Bacillus cereus ATCC 14579 and Listeria monocytogenes NCTT 10888) bacteria were screened. As far as concerns aluminum surfaces without nanotechnology surface treatment, an overall bacteriostatic effect was observed for all strains with respect to the initial inoculum that was 106 CFU/mL. Conversely, an overall bactericidal effect was observed both for Gram-negative and -positive bacteria on DURALTI®-treated aluminum disks, regardless of roughness and sanitizing treatment. These results are innovative in terms of the great potential of the antibacterial activity of nanotechnologically treated food contact surfaces and their combination with some sanitizing agents that might be exploited in the food industry.
Endometriosis Is Associated with a Significant Increase in hTERC and Altered Telomere/Telomerase Associated Genes in the Eutopic Endometrium, an Ex-Vivo and In Silico Study
Authors: Alnafakh Rafah , Choi Fiona , Bradfield Alice , Adishesh Meera , Saretzki Gabriele , Hapangama Dharani K.
Published: December 2020

Telomeres protect chromosomal ends and they are maintained by the specialised enzyme, telomerase. Endometriosis is a common gynaecological disease and high telomerase activity and higher hTERT levels associated with longer endometrial telomere lengths are characteristics of eutopic secretory endometrial aberrations of women with endometriosis. Our ex-vivo study examined the levels of hTERC and DKC1 RNA and dyskerin protein levels in the endometrium from healthy women and those with endometriosis (n = 117). The in silico study examined endometriosis-specific telomere- and telomerase-associated gene (TTAG) transcriptional aberrations of secretory phase eutopic endometrium utilising publicly available microarray datasets. Eutopic secretory endometrial hTERC levels were significantly increased in women with endometriosis compared to healthy endometrium, yet dyskerin mRNA and protein levels were unperturbed. Our in silico study identified 10 TTAGs (CDKN2A, PML, ZNHIT2, UBE3A, MCCC2, HSPC159, FGFR2, PIK3C2A, RALGAPA1, and HNRNPA2B1) to be altered in mid-secretory endometrium of women with endometriosis. High levels of hTERC and the identified other TTAGs might be part of the established alteration in the eutopic endometrial telomerase biology in women with endometriosis in the secretory phase of the endometrium and our data informs future research to unravel the fundamental involvement of telomerase in the pathogenesis of endometriosis.
CD146/sCD146 in the Pathogenesis and Monitoring of Angiogenic and Inflammatory Diseases
Authors: Heim Xavier , Joshkon Ahmad , Bermudez Julien , Bachelier Richard , Dubrou Cléa , Boucraut José , Foucault-Bertaud Alexandrine , Leroyer Aurélie S. , Dignat-George Francoise , Blot-Chabaud Marcel , Bardin Nathalie
Published: December 2020

CD146 is a cell adhesion molecule expressed on endothelial cells, as well as on other cells such as mesenchymal stem cells and Th17 lymphocytes. This protein also exists in a soluble form, whereby it can be detected in biological fluids, including the serum or the cerebrospinal fluid (CSF). Some studies have highlighted the significance of CD146 and its soluble form in angiogenesis and inflammation, having been shown to contribute to the pathogenesis of many inflammatory autoimmune diseases, such as systemic sclerosis, mellitus diabetes, rheumatoid arthritis, inflammatory bowel diseases, and multiple sclerosis. In this review, we will focus on how CD146 and sCD146 contribute to the pathogenesis of the aforementioned autoimmune diseases and discuss the relevance of considering it as a biomarker in these pathologies.
Polyvinylpyrrolidone-Stabilized Iridium Nanoparticles Catalyzed the Transfer Hydrogenation of Nitrobenzene Using Formic Acid as the Source of Hydrogen
Authors: Zhou Xinrui , Zhou Meng
Published: December 2020

Catalytic nitrobenzene reduction is crucial for the synthesis of 4,4-methylene diphenyl diisocyanate, which is used to produce polyurethane foams, thermoplastic elastomers, and adhesives. The stability and activity of nanoparticle catalysts are affected by surface ligands and stabilizers. We established the complete composition of 7.0 ± 1.1 nm iridium oxide nanoparticles that were stabilized by polyvinylpyrrolidone (PVP[Ir]). PVP[Ir] and its surface stabilizers were characterized using elemental analysis (EA), high-resolution X-ray photoelectron spectroscopy (XPS), powder X-ray diffraction (PXRD), FT-IR, and UV-vis spectroscopy. Notably, PVP[Ir] contained 33.8 ± 0.4% Ir. XPS binding energy analyses suggest that 7% of the Ir is Ir(0) and 93% is IrO2. Using formic acid as the source of hydrogen, PVP[Ir] catalyzed the selective hydrogenation of nitrobenzene to give aniline as the only product in 66% yield in 1 h at 160 °C in a high-pressure metal reactor. Less than 1% of the side products (azobenzene and azoxybenzene) were detected. In contrast, using alcohol as the hydrogen source led to a low yield and a poor selectivity for aniline.
Vulnerability and Risk Factors due to Tropical Cyclones in Coastal Cities of Baja California Sur, Mexico
Authors: Marín-Monroy Elvia Aida , Hernández-Trejo Víctor , Romero-Vadillo Eleonora , Ivanova-Boncheva Antonina
Published: December 2020

Coastal cities have seen an unprecedented growth with regional settlements due to development activities; that is why measures are needed to mitigate risk of adverse events such as tropical cyclones. Baja California Sur, a state known as a relevant ecological and tourist region, includes destinations such as Cabo San Lucas and La Paz, impacted yearly by tropical cyclones, so it is important to design contingency plans and provide available information to the residents. Los Cabos municipality has the highest population growth rate and its inhabitants are more susceptible to adverse events; despite this, there were no indicators of social and ecological vulnerability to risk effects of tropical cyclones. The objective of this research is to calculate the socio-environmental vulnerability of households through an index to identify risk factors. We have obtained a classification according to levels of vulnerability, and the results have shown that 74% of the households are high on the vulnerability scale, 21% of households are moderately vulnerable and only the remaining 5% of households are less vulnerable. In conclusion, the devastating effects of hydrometeorological events were mainly due to a lack of knowledge regarding such events among inhabitants.
FuseVis: Interpreting Neural Networks for Image Fusion Using Per-Pixel Saliency Visualization
Authors: Kumar Nishant , Gumhold Stefan
Published: December 2020

Image fusion helps in merging two or more images to construct a more informative single fused image. Recently, unsupervised learning-based convolutional neural networks (CNN) have been used for different types of image-fusion tasks such as medical image fusion, infrared-visible image fusion for autonomous driving as well as multi-focus and multi-exposure image fusion for satellite imagery. However, it is challenging to analyze the reliability of these CNNs for the image-fusion tasks since no groundtruth is available. This led to the use of a wide variety of model architectures and optimization functions yielding quite different fusion results. Additionally, due to the highly opaque nature of such neural networks, it is difficult to explain the internal mechanics behind its fusion results. To overcome these challenges, we present a novel real-time visualization tool, named FuseVis, with which the end-user can compute per-pixel saliency maps that examine the influence of the input image pixels on each pixel of the fused image. We trained several image fusion-based CNNs on medical image pairs and then using our FuseVis tool we performed case studies on a specific clinical application by interpreting the saliency maps from each of the fusion methods. We specifically visualized the relative influence of each input image on the predictions of the fused image and showed that some of the evaluated image-fusion methods are better suited for the specific clinical application. To the best of our knowledge, currently, there is no approach for visual analysis of neural networks for image fusion. Therefore, this work opens a new research direction to improve the interpretability of deep fusion networks. The FuseVis tool can also be adapted in other deep neural network-based image processing applications to make them interpretable.
Changes in Skin Elasticity and Firmness Caused by Cosmetic Formulas Elaborated with Essential Oils of Aristeguietia glutinosa (matico) and Ocotea quixos (ishpingo). A Statistical Analysis
Authors: Mosquera Tatiana , Peña Sebastián , Álvarez Priscila , Noriega Paco
Published: December 2020

External factors such as prolonged exposure to solar radiation and environmental pollution accelerate the aging process of the skin, and this process is a challenge for pharmacological science. To counteract the effects of skin photoaging, the cosmetic industry has introduced natural topical products that have proved to be effective in reducing signs of age. In this sense, a statistical analysis was conducted on the changes in the properties of firmness and elasticity of the skin caused by cosmetic formulas (lotion and cream) elaborated with essential oils of Aristeguietia glutinosa (matico) and Ocotea quixos (ishpingo) in which the concentration of the oils in two cosmetic products (lotion and cream) varied to be tested in vivo, through the measurement of elasticity and firmness in three times T1 (0 day), T2 (28 days) and T3 (56 days), and in two age groups according to the Glogau scale (30 to 40 and 41 to 50 years). The results showed positive changes in the values of elasticity and firmness of the skin in the presentation of the lotion whose concentration was 20% Aristeguietia glutinosa (matico) and 80% Ocotea quixos (ishpingo), with a minimum application time of 28 days.
How Long Has It Taken for the Physical Landscape to Form? Conceptions of Spanish Pre-Service Teachers
Authors: Gómez-Gonçalves Alejandro , Corrochano Diego , Fuertes-Prieto Miguel Ángel , Ballegeer Anne-Marie
Published: December 2020

This paper analyses the conceptions of a group of students about geological time and its relation to physical landscape formation, focusing on the frequency and rate of a number of geological processes that have shaped our planet over time and that are involved in the formation of the current relief. Data were collected by means of a questionnaire that was administered to 199 university students from a Spanish public university. A total of 185 of them were pre-service teachers and 14 were geology students. Results demonstrated that pre-service teachers had trouble correctly answering questions about the current relief, but especially those questions related to landscapes throughout the history of Earth. Data analysis was done, taking into account pre-university students’ tuition, and results showed that those who had taken a high school branch of sciences and technology obtained better results than those who had taken a humanities and social sciences branch. These latter also obtained better results than those who had taken arts as a high school branch. Furthermore, pre-service teachers had difficulties mastering mid-time magnitudes, which ended up making it difficult for them to understand how the physical landscapes were formed. Finally, from the obtained results, some curricula implications are discussed.
Resistive Switching in Non-Stoichiometric Germanosilicate Glass Films Containing Ge Nanoclusters
Authors: Volodin Vladimir A. , Geydt Pavel , Kamaev Gennadiy N. , Gismatulin Andrei A. , Krivyakin Grigory K. , Prosvirin Igor P. , Azarov Ivan A. , Fan Zhang , Vergnat Michel
Published: December 2020

Metal–insulator–semiconductor (MIS) structures based on thin GeO[SiO2] and GeO[SiO] films on Si substrates were fabricated with indium-tin-oxide as a top electrode. The samples were divided it two series: one was left as deposited, while the second portion of MIS structures was annealed at 500 °C in argon for 20 min. The structural properties of as-deposited and annealed non-stoichiometric germanosilicate (GeSixOy) films were studied using X-ray photoelectron spectroscopy, electron microscopy, Raman and infrared absorption spectroscopy, spectral ellipsometry, and transmittance and reflectance spectroscopy. It was found that the as-deposited GeO[SiO] film contained amorphous Ge clusters. Annealing led to the formation of amorphous Ge nanoclusters in the GeO[SiO2] film and an increase of amorphous Ge volume in the GeO[SiO] film. Switching from a high resistance state (HRS OFF) to a low resistance state (LRS ON) and vice versa was detected in the as-deposited and annealed MIS structures. The endurance studies showed that slight degradation of the memory window occurred, mainly caused by the decrease of the ON state current. Notably, intermediate resistance states were observed in almost all MIS structures, in addition to the HRS and LRS states. This property can be used for the simulation of neuromorphic devices and related applications in data science.
Systematic Study of the Influence of the Angle of Incidence Discretization in Reflectarray Analysis to Improve Support Vector Regression Surrogate Models
Authors: Prado Daniel R. , López-Fernández Jesús A. , Arrebola Manuel
Published: December 2020

A systematic study concerning the discretization of the angle of incidence in surrogate models obtained with support vector regression (SVR) is presented. The problem addressed in this work arises from the dependence of the reflection coefficients on the angle of incidence. While the direct coefficients are usually stable with the angle of incidence, this is not the case with the cross-coefficients, which translates this behavior to the crosspolar component of the radiation pattern. Then, correctly assessing this influence and minimizing radiation pattern distortion allow training SVR surrogate models per angle of incidence without penalizing accuracy in the prediction of the far field. The results shown in this work are directly relevant to improving the computational performance of SVRs applied to reflectarray design since they allow reducing the dimensionality of the models by generating surrogate models per angle of incidence instead of including the angles of incidence as input variables. In addition, it highlights the importance of a proper discretization of the angles of incidence for a correct prediction of the crosspolar pattern for its subsequent optimization, especially for advanced space applications with tight crosspolar requirements.
A Time-Based Dynamic Operation Model for Webpage Steganography Methods
Authors: Yuk Simun , Cho Youngho
Published: December 2020

The webpage steganography technique has been used for a covert communication method for various purposes in which a sender embeds a secret message into a plain webpage file like an HTML file by using various steganography methods. With human eyes, it is very difficult to distinguish between the original webpage (cover webpage) and the modified webpage with the secret data (stego webpage) because both are displayed alike in a web browser. In this approach, when two communicating entities want to share a secret message, a sender uploads a stego webpage to a web server or modifies an existing webpage in the web server by using a webpage steganography method, and then a receiver accesses the stego webpage to download and extract the embedded secret data from it. Meanwhile, according to our extensive survey, we observed that most webpage steganography methods focused on proposing or improving steganography algorithms but did not well address how to operate a stego webpage as time passes. However, if a stego webpage is used in a static way such that the stego webpage does not change and is constantly exposed to web clients until the sender removes it, such a static operation approach will limit or badly affect the hiding capacity and undetectability of a webpage steganography method. By this motivation, in this paper, we proposed a time-based dynamic operation model (TDOM) that improves the performance of existing webpage steganography methods in terms of hiding capacity and undetectability by dynamically replacing the stego webpage with other stego webpages or the original webpage. In addition, we designed two time-based dynamic operation algorithms (TDOA-C and TDOA-U), which improve the hiding capacity of existing methods and TDOA-U for improving the undetectability of existing methods, respectively. To validate our model and show the performance of our proposed algorithms, we conducted extensive comparative experiments and numerical analysis by implementing two webpage steganography methods with our TDOM (CCL with TDOA-C and COA with TDOA-C) and tested them in the web environment. According to our experiments and analysis, our proposed algorithms could significantly improve the hiding capacity and undetectability of two existing webpage steganography methods.
Effects of Welding Time and Electrical Power on Thermal Characteristics of Welding Spatter for Fire Risk Analysis
Authors: Shin Yeon Je , You Woo Jun
Published: December 2020

To predict the fire risk of spatter generated during shielded metal arc welding, the thermal characteristics of welding spatter were analyzed according to different welding times and electrical powers supplied to the electrode. An experimental apparatus for controlling the contact angle between the electrode and base metal as well as the feed rate was prepared. Moreover, the correlations among the volume, maximum diameter, scattering velocity, maximum number, and maximum temperature of the welding spatter were derived using welding power from 984–2067 W and welding times of 30 s, 50 s, and 70 s. It was found that the volume, maximum diameter, and maximum number of welding spatters increased proportionally as the welding time and electrical power increased, but the scattering velocity decreased as the particle diameter increased regardless of the welding time and electrical power. When the measured maximum temperature of the welding spatter was compared with an empirical formula, the accuracy of the results was confirmed to be within ±7% of the experimental constant C=112.414×Pe−0.5045. Results of this study indicate quantitatively predicting the thermal characteristics of welding spatter is possible for minimizing the risk of fire spread when the electrode type and welding power is known.
Hierarchical Two-Layer Distributed Control Architecture for Voltage Regulation in Multiple Microgrids in the Presence of Time-Varying Delays
Authors: Andreotti Amedeo , Caiazzo Bianca , Petrillo Alberto , Santini Stefania , Vaccaro Alfredo
Published: December 2020

The Multiple Microgrids (MMGs) concept has been identified as a promising solution for the management of large-scale power grids in order to maximize the use of widespread renewable energies sources. However, its deployment in realistic operation scenarios is still an open issue due to the presence of non-ideal and unreliable communication systems that allow each component within the power network to share information about its state. Indeed, due to technological constraints, multiple time-varying communication delays consistently appear during data acquisition and the transmission process and their effects must be considered in the control design phase. To this aim, this paper addresses the voltage regulation control problem for MMGs systems in the presence of time-varying communication delays. To solve this problem, we propose a novel hierarchical two-layer distributed control architecture that accounts for the presence of communication latencies in the information exchange. More specifically, the upper control layer aims at guaranteeing a proper and economical reactive power dispatch among MMGs, while the lower control layer aims at ensuring voltage regulation of all electrical buses within each MG to the desired voltage set-point. By leveraging a proper Driver Generator Nodes Selection Algorithm, we first provide the best choice of generator nodes which, considering the upper layer control goal, speeds up the voltage synchronization process of all the buses within each MG to the voltage set-point computed by the upper-control layer. Then, the lower control layer, on the basis of this desired voltage value, drives the reactive power capability of each smart device within each MG and compensates for possible voltage deviations. Simulation analysis is carried out on the realistic case study of an MMGs system consisting of two identical IEEE 14-bus test systems and the numerical results disclose the effectiveness of the proposed control strategy, as well as its robustness with respect to load fluctuations.
Environmental Impacts of Charging Concepts for Battery Electric Vehicles: A Comparison of On-Board and Off-Board Charging Systems Based on a Life Cycle Assessment
Authors: Kabus Mona , Nolting Lars , Mortimer Benedict J. , Koj Jan C. , Kuckshinrichs Wilhelm , De Doncker Rik W. , Praktiknjo Aaron
Published: December 2020

We investigate the environmental impacts of on-board (based on alternating current, AC) and off-board (based on direct current, DC) charging concepts for electric vehicles using Life Cycle Assessment and considering a maximum charging power of 22 kW (AC) and 50 kW (DC). Our results show that the manufacturing of chargers provokes the highest contribution to environmental impacts of the production phase. Within the chargers, the filters could be identified as main polluters for all power levels. When comparing the results on a system level, the DC system causes less environmental impact than the AC system in all impact categories. In our diffusion scenarios for electric vehicles, annual emission reductions of up to 35 million kg CO2-eq. could be achieved when the DC system is used instead of the AC system. In addition to the environmental assessment, we examine economic effects. Here, we find annual savings of up to 8.5 million euros, when the DC system is used instead of the AC system.
Research on Comprehensive Value of Electrical Energy Storage in CCHP Microgrid with Renewable Energy Based on Robust Optimization
Authors: Zhao Huiru , Lu Hao , Wang Xuejie , Li Bingkang , Wang Yuwei , Liu Pei , Ma Zhao
Published: December 2020

The combined cooling, heating, and power (CCHP) microgrid system is good for energy gradient utility. At the same time, it can promote the renewable energy (RE) consumption and abate environmental pollution. In a CCHP microgrid system, the electrical energy storage (EES), which can storage and release electrical energy, plays an indispensable role. A robust optimization model of the CCHP microgrid participating in power market transaction is constructed to calculate the CCHP microgrid operation cost in 4 cases. The results show that the EES can significantly reduce the cost of the CCHP microgrid by 13.21%, compared with 8.36% in Group 1 without renewable energy. The EES can reduce the reserved capacity of micro gas turbine units to deal with the precariousness of RE generation and then reduce the CCHP microgrid operation cost by reducing the purchase of energy from the power grid and arbitrage. Finally, the calculation method of comprehensive value of the EES is constructed. The comprehensive value of the EES is higher in Group 2 with renewable energy compared with Group 1 without renewable energy. Through net present value (NPV) calculation and sensitivity analysis, it is found that the RE penetration level and EES cost have the greatest impact on the economic performance of EES. This shows that with the continuous rising of the RE penetration level and the gradual decrease of EES cost, great potential still waits to be tapped in the comprehensive value of EES in the future.
A Secondary-Side Controlled Electric Vehicle Wireless Charger
Authors: Corti Fabio , Reatti Alberto , Nepote Andrea , Pugi Luca , Pierini Marco , Paolucci Libero , Grasso Francesco , Grasso Emanuele , Nienhause Matthias
Published: December 2020

In this paper, the design procedure of an electric vehicle (EV) wireless charger is presented. Unlike most of the systems available in the literature, the proposed charging system is regulated from the vehicle side. The on-board electrical circuit automatically adapts the resonant compensation to guarantee compatibility with the primary inverter characteristics and achieve high transmission efficiency without communication between sides. Moreover, the proposed control strategy, used to regulate the secondary full active rectifier (FAR), allows the supply of the the EV battery, maximizing the efficiency during the whole charging process.
Induction Motor Fault Diagnosis Based on Zero-Sequence Current Analysis
Authors: Duda Arkadiusz , Drozdowski Piotr
Published: December 2020

This paper presents some considerations regarding the application of the stator zero-sequence current component (ZSC) in the fault detection of cage induction machines, including the effects of magnetic core saturation. Faults such as rotor cage asymmetry and static, dynamic, and mixed eccentricity were considered. The research started by developing a harmonic motor model, which allowed us to obtain a voltage equation for the zero-sequence current component. The equation allowed us to extract formulas of typical frequencies for particular fault types. Next, in order to verify the effectiveness of ZSC in induction motor fault diagnosis, finite element calculations and laboratory tests were carried out for the previously mentioned faults for delta and wye connections with neutral wire stator winding configurations.
History Lessons from the Late Joseon Dynasty Period of Korea: Human Technology (Ondol), Its Impacts on Forests and People, and the Role of the Government
Authors: Bae Jae Soo , Kim Yeon-Su
Published: December 2020

Historical analogies can help us contextualize new technical developments with social, cultural, and political forces at work. The late Joseon Dynasty period of Korea (1639–1910), a closed economy with detailed written records, provides a rare opportunity to examine a social-ecological system (SES) responding to drivers of change over a long period of time. Based on historical records and reconstructed data, we aim to: (1) characterize how the expansion of human technology, Ondol (traditional underfloor heating system), affected different subsystems and their interactions within the SES over time, (2) examine the role of the government in promoting the technology and regulating its impacts, and (3) summarize the pertinent lessons learned from old Korea for governing a modern-day bioeconomy. Ondol allows various forest biomass to be utilized as household fuel, including fuelwood, forest litter, and grass scraped from forest floor. Continuous biomass harvesting over 250 years to feed Ondol contributed to forest degradation and the forest ecosystem condition trapped in the early successional stage in the Korean Peninsula. The ecological changes were exacerbated by the Pine Policy with a singular focus on reserving Korean red pine (Pinus densiflora Siebold and Zucc.) for government uses. The policy failed to recognize basic needs of the public while countenancing an expansion of Ondol and a cultural preference for heated floors that propagated an increased use of biomass fuel. This case illustrates the importance of recognizing potential technology traps where a human innovation opened opportunities for more resource use. The lessons learned from old Korea show that bioeconomy transitions would require multifaceted governance responses while being cautious about being too closely tied to the dominant national agenda. Environmental history has much to offer for understanding the social and ecological systemic risks of the current technical developments. We call for more historical analogs from different parts of the world to “move forward by looking back”.
Examining Long-Term Effects of Human Papillomavirus Vaccine Recommendation Messages: A 4-Month Follow-Up Survey of a Randomized Controlled Study in Japan
Authors: Okuhara Tsuyoshi , Ishikawa Hirono , Ueno Haruka , Okada Hiroko , Kiuchi Takahiro
Published: December 2020

We previously conducted a randomized controlled study to examine persuasive messages recommending HPV vaccination to mothers with daughters in Japan. That study showed that the three types of intervention message used (statistical information only, a patient’s narrative in addition to statistical information, and a mother’s narrative in addition to statistical information) all significantly improved mothers’ intention to have their daughter(s) receive the HPV vaccine, in comparison with mothers who received no messaging. The present study is a follow-up survey to assess the long-term effect of the intervention. Four months after the initial study, in January 2018, participants in the previous study were contacted and queried about their current intention to have their daughter(s) receive the HPV vaccine. Statistical analysis was conducted using the paired t-test and analysis of variance. A total of 978 mothers participated in the current survey. Vaccination intention 4 months after intervention had decreased to a level that did not differ significantly from the level prior to intervention in all three intervention conditions. The amount of change in vaccination intention 4 months after intervention did not differ significantly among the three intervention groups (p = 0.871). A single exposure to messaging was insufficient to produce a persistent intervention effect.
Management of Occupational Risk Prevention of Nanomaterials Manufactured in Construction Sites in the EU
Authors: López-Alonso Mónica , Díaz-Soler Beatriz , Martínez-Rojas María , Fito-López Carlos , Martínez-Aires María Dolores
Published: December 2020

Currently, nanotechnology plays a key role for technological innovation, including the construction sector. An exponential increase is expected in its application, although this has been hampered by the current degree of uncertainty regarding the potential effects of nanomaterials on both human health and the environment. The accidents, illnesses, and disease related to the use of nanoproducts in the construction sector are difficult to identify. For this purpose, this work analyzes in depth the products included in recognized inventories and the safety data sheets of these construction products. Based on this analysis, a review of the recommendations on the use of manufactured nanomaterials at construction sites is performed. Finally, a protocol is proposed with the aim of it serving as a tool for technicians in decision-making management at construction sites related to the use of manufactured nanomaterials. This proposed protocol should be an adaptive and flexible tool while the manufactured nanomaterials-based work continues to be considered as an “emerging risk,” despite the expectation that the protocol will be useful for the development of new laws and recommendations for occupational risk prevention management.