bluuebunny/crossref_metadata_2025 huggingface dataset:
A Review on Sampling Techniques and Analytical Methods for Microbiota of Cultural Properties and Historical Architecture
Authors: Ding Xinghua , Lan Wensheng , Gu Ji-Dong
Published: November 2020

World cultural heritage suffers from deterioration caused by both natural and anthropogenic processes, among which microorganisms are significantly involved. Among the key issues of this topic, sampling techniques and analytical methods for revealing the microbiome are fundamental to obtaining useful results for understanding the key players and processes involved, and also for effective protection and management of the cultural heritage for humanity. A non-invasive and non-destructive sampling method is required for sampling of cultural properties prior to further analysis of the microbiome. One example is illustrated in this article. For many years, culture-dependent methods had been used before the invention of polymerase-chain reaction (PCR) methods and, more recently, specifically high-throughput next generation sequencing (NGS). NGS reveals the whole microbial community composition and the active microorganisms from genomic DNA and RNA, respectively. The recovered environmental DNA and RNA from samples provide the information on microbial community and composition, and the active members and biochemical processes of the microbial attributes. It should be emphasized that the metabolically-active members of functional microflora in the biofilm or microbiome on cultural heritage must be determined and identified from the RNA-based analysis to gain a substantially important insight of the active biodeterioration processes and also the effectiveness of the conservation strategies. The importance of the culture-independent technique, based on NGS, is that it can be used in combination with the conventional culturing methods to guide the isolation and enrichment of new microorganisms to gain further biochemical insights to advance the role of the specific microbial groups for biodeterioration of cultural heritage. At the same time, effective restoration and maintenance strategies can be formulated for the protection of world cultural heritage.
Stress-Based Weibull Method to Select a Ball Bearing and Determine Its Actual Reliability
Authors: Villa-Covarrubias Baldomero , Piña-Monarrez Manuel R. , Barraza-Contreras Jesús M. , Baro-Tijerina Manuel
Published: November 2020

Since the designed bearing’s reliability of 90% was determined in a lab environment, it does not represent the actual used environment. In this paper, a new methodology to determine the actual reliability that corresponds to the use conditions is offered. This new method is based on the standard method used to select the ball bearing. The proposed method is based on the two parameters of Weibull distribution, where the shape (β) and scale (η) parameters are both determined from the Hertz contact stresses values, which are generated under the surface of the motionless outer race, and by the forces transmitted between the ball and the outer race. Therefore, the derived reliability is different from the 90% index offered by manufacturers.
Leaky Lamb Wave Radiation from a Waveguide Plate with Finite Width
Authors: Park Sang-Jin , Kim Hoe-Woong , Joo Young-Sang
Published: November 2020

In this paper, leaky Lamb wave radiation from a waveguide plate with finite width is investigated to gain a basic understanding of the radiation characteristics of the plate-type waveguide sensor. Although the leaky Lamb wave behavior has already been theoretically revealed, most studies have only dealt with two dimensional radiations of a single leaky Lamb wave mode in an infinitely wide plate, and the effect of the width modes (that are additionally formed by the lateral sides of the plate) on leaky Lamb wave radiation has not been fully addressed. This work aimed to explain the propagation behavior and characteristics of the Lamb waves induced by the existence of the width modes and to reveal their effects on leaky Lamb wave radiation for the performance improvement of the waveguide sensor. To investigate the effect of the width modes in a waveguide plate with finite width, propagation characteristics of the Lamb waves were analyzed by the semi-analytical finite element (SAFE) method. Then, the Lamb wave radiation was computationally modeled on the basis of the analyzed propagation characteristics and was also experimentally measured for comparison. From the modeled and measured results of the leaky radiation beam, it was found that the width modes could affect leaky Lamb wave radiation with the mode superposition and radiation characteristics were significantly changed depending on the wave phase of the superposed modes on the radiation surface.
Improved Model Predictive-Based Underwater Trajectory Tracking Control for the Biomimetic Spherical Robot under Constraints
Authors: Hou Xihuan , Guo Shuxiang , Shi Liwei , Xing Huiming , Yin He , Li Zan , Zhou Mugen , Xia Debin
Published: November 2020

To improve the autonomy of the biomimetic sphere robot (BSR), an underwater trajectory tracking problem was studied. Considering the thrusters saturation of the BSR, an improved model predictive control (MPC) algorithm that features processing multiple constraints was designed. With the proposed algorithm, the kinematic and dynamic models of the BSR are combined in order to establish the predictive model, and a new state-space model is designed that is based on an increment of the control input. Furthermore, to avoid the infeasibility of the cost function in the MPC controller design, a new term with a slack variable is added to the objective function, which enables the constraints to be imposed as soft constraints. The simulation results illustrate that the BSR was able to track the desired trajectory accurately and stably while using the improved MPC algorithm. Furthermore, a comparison with the traditional MPC shows that the designed MPC-based increment of the control input is small. In addition, a comparative simulation using the backstepping method verifies the effectiveness of the proposed method. Unlike previous studies that only focused on the simulation validations, in this study a series of experiments were carried out that further demonstrate the effectiveness of the improved MPC for underwater trajectory tracking of the BSR. The experimental results illustrate that the improved MPC is able to drive the BSR to quickly track the reference trajectory. When compared with a traditional MPC and the backstepping method used in the experiment, the proposed MPC-based trajectory is closer to the reference trajectory.
Safety Operation of n-DOF Serial Hydraulic Manipulator in Constrained Motion with Consideration of Contact-Loss Fault
Authors: Truong Hoai Vu Anh , Trinh Hoai An , Ahn Kyoung Kwan
Published: November 2020

In consideration of accidental contact-loss due to step-change or accidentally moving out of a constrained framework, this paper focuses on solving this problem during working processes of an n-degree-of-freedom hydraulic manipulator (n-DOF manipulator). In order to overcome this phenomenon, a fault detection methodology-based virtual energy tank is employed with a shaping function to prevent the end-effector from damage or unexpected motion. This technique helps to detect when the contact-loss happens by a virtual energy variable; thus, decoupling a force control regulation. Moreover, a new trajectory for smooth motion after contact-loss detection is also discussed to increase system robustness. Additionally, to enhance tracking performance, adaptive laws are designed to compensate for system uncertainties. Comparative simulations are given on the n-DOF hydraulic manipulator to evaluate effectiveness of the impedance-based energy tank methodology under the sudden step-changed environment. Moreover, influences of control gains and setup energy parameters to the system behaviors when contact-loss happens are remarkably discussed as indispensable criteria for further development. The simulated results certified the superior effectiveness and reliability of the suggested methodology over the conventional impedance control for safe operation.
TD-DFT Prediction of the Intermolecular Charge-Transfer UV-Vis Spectra of Viologen Salts in Solution
Authors: Saielli Giacomo
Published: November 2020

The absorption spectrum of viologen salts in a medium or low polar solvent is an essential feature that influences all its “chromic” applications, whether we are considering thermochromic, electrochromic, photochromic or chemochromic devices. The prediction by quantum chemical methods of such absorption bands, typically observed in the visible range and due to charge transfer (CT) phenomena, is a very challenging problem due to strong solvent effects influencing both the geometry and the electronic transitions. Here we present a computational protocol based on DFT to predict with very high accuracy the absorption maxima of the CT bands of a series of viologen salts in solvents of low and medium polarity. The calculations also allow a clear dissection of the solvent effects, direct and indirect, and orbital contributions to the CT band.
Relationships among Permeability, Membrane Roughness, and Eukaryote Inhabitation during Submerged Gravity-Driven Membrane (GDM) Filtration
Authors: Lee Dongwhi , Cha Yun Jeong , Baek Youngbin , Choi Shin Sik , Lee Yunho
Published: November 2020

Gravity-driven membrane (GDM) filtration is one of the promising technologies for decentralized water treatment systems due to its low cost, simple operation, and convenient maintenance. The objective of this study was to evaluate the permeability of submerged GDM filtration with three different membranes, i.e., polyethersulfone and polyvinylidene difluoride ultrafiltration (PES-UF and PVDF-UF) and polytetrafluoroethylene microfiltration membrane (PTFE-MF). The GDM system was operated using lake water for about one year. The determined average permeability values were high for PVDF-UF (192.9 L/m2/h/bar (LMH/bar)) and PTFE-MF (80.6 LMH/bar) and relatively lower for PES-UF (46.1 LMH/bar). The observed higher permeability for PVDF-UF and PTFE-MF was thought to be related to the rougher surface of these two membranes compared to PES-UF. The fouling layers of PVDF-UF and PTFE-MF were characterized by high biomass and the presence of a number of nematodes, while PES-UF showed a thin fouling layer with no nematode. The relatively high and fluctuated permeability of PVDF-UF and PTFE-MF could thus be attributed to the high biological activity of nematodes making the fouling layer more loose and porous. This was supported by a good linear relationship among the permeability, biomass concentration, and the number of nematodes in the fouling layers. These results provide important insights into membrane selection as a critical factor affecting the flux performance of the GDM filtration system for a decentralized drinking water supply.
Feasibility Study of Pump Units with Various Direct-On-Line Electric Motors Considering Cable and Transformer Losses
Authors: Kazakbaev Vadim , Prakht Vladimir , Dmitrievskii Vladimir , Golovanov Dmitry
Published: November 2020

The high energy intensity of the modern industry determines the high urgency of increasing the energy efficiency of production processes. However, a big number of motor types of enhanced efficiency classes are available on the market. The motor users can be confused about the choice of the right motor solution for a certain application. In this paper, to help with this choice the energy efficiency indicators of various types of electric motors in a low-power pump unit with a constant rotation speed are studied. Moreover, not only power losses in the motor are considered, but also power losses in the cable and transformer, which are influenced by the power factor of the motor. Induction motors (IMs) and synchronous motors powered directly from the grid (direct-on-line synchronous motor with permanent magnet in the rotor, DOL PMSM; direct-on-line synchronous reluctance motor without permanent magnet, DOL SynRM) of IE2, IE3, and IE4 energy efficiency classes are compared. To carry out the analysis, polynomial interpolation of the available catalogue data and experimental data of the motors are used. The main criteria for comparing different motors in this work are the energy savings over the pump’s life cycle and the payback period when replacing an IE2 motor with a motor of a higher energy efficiency class. The article shows that although the DOL PMSM has a lower motor efficiency than the DOL SynRM, it saves more energy due to its higher power factor, which reduces cable and transformer losses. It is also shown that, despite the highest initial cost, when taking into account cable and transformer losses, the payback period of DOL PMSM can be shorter than that of IE3 and IE4 induction motors. DOL SynRM has the shortest payback period in all considered cases, has no troublesome rare-earth permanent magnets, and can also be a valuable solution.
Meteorological Detrending of Ozone at Three Sites in the Dallas-Fort Worth Area: Application of KZ Filter Method
Authors: Upadhaya Poojan , Du Hongbo , Kommalapati Raghava R.
Published: November 2020

The Dallas-Fort Worth (DFW) area that experiences high temperature and intense solar radiation falls into the moderate nonattainment classification. The variation in meteorological parameters plays an important role in ambient ozone levels variation. Meteorological influences need to be decoupled from ozone data for long-term trend analysis. Temporal separation of maximum daily average 8-h ozone (MDA8 ozone), maximum daily temperature (TMAX), daily average solar radiation (DASR), and daily average wind speed (DAWS) were conducted using Kolmogorov-Zurbenko (KZ) filter for ozone records at Keller (C17), Arlington (C61), Red Bird (C402) monitoring stations in the DFW area from 2003 to 2017. Temporal separation, regression analysis, and meteorological detrending were performed. The long-term component had a clear and stable trend. The contribution of the long-term component to total variation was negligible, which is less than 2%. This is due to the removal of the data noise from the original time series data. The seasonal component had a major contribution (55% to 72%) in the total variation of the maximum temperature and solar radiation. However, the short-term component was dominant in the total variation of the MDA8 ozone (41–54%) and wind speed (68–79%). Regression analysis showed the baseline component bears the highest correlation than the short-term and raw. Solar radiation had the highest correlation to the MDA8 ozone, followed by temperature data in all three stations. Meteorological detrending showed the detrended long-term ozone had an increasing trend. The increasing trend was significant at C402 with a trend of 0.19 ± 0.006 ppb/y (0.398 R2), whereas slight increasing trends were found at C17 (0.072 ± 0.006 (0.107 R2)) and at C61 (0.019 ± 0.007 (0.005 R2)). The increasing trend of long-term components of MDA8 ozone was justified by the increasing level of NOx and VOCs from the mobile sources in the DFW area.
Variability of Chemical Properties of the Atmospheric Aerosol above Lake Baikal during Large Wildfires in Siberia
Authors: Golobokova Liudmila , Khodzher Tamara , Khuriganova Olga , Marinayte Irina , Onishchuk Natalia , Rusanova Polina , Potemkin Vladimir
Published: November 2020

The article analyzes the chemical composition (ions, elements, and polycyclic aromatic hydrocarbons) of the atmospheric aerosol in the near-water layer of the atmosphere above Lake Baikal during wildfires in Siberia. Aerosol deposition affects the aquatic environment of the watershed basin and the lake itself. The current law on Lake Baikal limits the activity of the permanent stationary anthropogenic sources of the aerosol in the central ecological zone, and they do not have a significant negative impact. Wildfires can have a much greater impact on the environment. Smoke emissions entering the area of Lake Baikal due to wildfires change the chemical properties of the atmospheric aerosol and increase its mass and number concentration. The concentrations of NH4+, K+, NO3−, and SO42−, which enter with submicron aerosol fraction, increase in the ionic composition of the aerosol. The composition of polyaromatic compounds changes, and their concentrations increase. Elevated concentrations of B, Mn, Zn, As, Sr, Cd, and Pb in the composition of aerosol indicate the influx of air masses from the areas prone to wildfires. Despite the sporadic effects of these natural factors, they affect the pollution of various Baikal ecosystems, especially small tributaries of the lake, whose main supply is atmospheric.
Development of Precise Indices for Assessing the Potential Impacts of Climate Change
Authors: Kumar Vinay
Published: November 2020

The Special Issue on climate indices and climate change deals with various kinds of indices exits to assess weather and climate over a region. These indices might be based on local, regional, remote variables, which may affect and define the weather and climate of a region. Climate indices are the time series used to monitor the state of the climate and its relationship with other possible causes. With indices being myriad, it is challenging to choose which one is appropriate for a region of interest. However, the relationship between the indices and the climate of a region varies. El-Nino Southern Oscillation (Southern Oscillation Index, SOI/ENSO) is one of the most robust climate signals that stimulate rainfall, temperature, and hurricanes via teleconnections. SOI has a correlation of 0.5 over the Indonesian archipelago. Here, some of the well-known indices Holiday Climate Index (HCI), Tourism Climate Index (TCI), and Simple Diversity Index (SDI) are being reconnoitered to understand the holiday-tourism, end-of-the-day (EOD) judgment. The intrusion of dry air in the middle troposphere can create unstable weather, leading to heavy precipitation. The Special Issue seeks to encourage researchers to discover new indices in multidisciplinary department of atmospheric and physical sciences.
Novel Bionics Assessment of Anorectal Mechanosensory Physiology
Authors: Gregersen Hans
Published: November 2020

Biomechatronics (bionics) is an applied science that creates interdisciplinary bonds between biology and engineering. The lower gastrointestinal (GI) tract is difficult to study but has gained interest in recent decades from a bionics point of view. Ingestible capsules that record physiological variables during GI transit have been developed and used for detailed analysis of colon transit and motility. Recently, a simulated stool named Fecobionics was developed. It has the consistency and shape of normal stool. Fecobionics records a variety of parameters including pressures, bending, and shape changes. It has been used to study defecation patterns in large animals and humans, including patients with symptoms of obstructed defecation and fecal incontinence. Recently, it was applied in a canine colon model where it revealed patterns consistent with shallow waves originating from slow waves generated by the interstitial Cells of Cajal. Novel analysis such as the “rear-front” pressure diagram and quantification of defecation indices has been developed for Fecobionics. GI research has traditionally been based on experimental approaches. Mathematical modeling is a unique way to deal with the complexity. This paper describes the Fecobionics technology, related mechano-physiological modeling analyses, and outlines perspectives for future applications.
β-Hexachlorocyclohexane: A Small Molecule with a Big Impact on Human Cellular Biochemistry
Authors: Rubini Elisabetta , Paglia Giuliano , Cannella David , Macone Alberto , Di Sotto Antonella , Gullì Marco , Altieri Fabio , Eufemi Margherita
Published: November 2020

Organochlorine pesticides (OCPs) belong to a heterogeneous class of organic compounds blacklisted by the Stockholm Convention in 2009 due to their harmful impact on human health. Among OCPs, β-hexachlorocyclohexane (β-HCH) is one of the most widespread and, at the same time, poorly studied environmental contaminant. Due to its physicochemical properties, β-HCH is the most hazardous of all HCH isomers; therefore, clarifying the mechanisms underlying its molecular action could provide further elements to draw the biochemical profile of this OCP. For this purpose, LNCaP and HepG2 cell lines were used as models and were subjected to immunoblot, immunofluorescence, and RT-qPCR analysis to follow the expression and mRNA levels, together with the distribution, of key biomolecules involved in the intracellular responses to β-HCH. In parallel, variations in redox homeostasis and cellular bioenergetic profile were monitored to have a complete overview of β-HCH effects. Obtained results strongly support the hypothesis that β-HCH could be an endocrine disrupting chemical as well as an activator of AhR signaling, promoting the establishment of an oxidative stress condition and a cellular metabolic shift toward aerobic glycolysis. In this altered context, β-HCH can also induce DNA damage through H2AX phosphorylation, demonstrating its multifaceted mechanisms of action.
Performing Quality Assurance of Carbon Dioxide for Carbon Capture and Storage
Authors: Murugan Arul , Brown Richard J. C. , Wilmot Robbie , Hussain Delwar , Bartlett Sam , Brewer Paul J. , Worton David R. , Bacquart Thomas , Gardiner Tom , Robinson Rod A. , Finlayson Andrew J.
Published: November 2020

Impurities in carbon dioxide can affect several aspects of the carbon capture and storage process, including storage capacity, rock erosion, accuracy of flow meters, and toxicity of potential leaks. There is an industry need for guidance on performing purity analysis before carbon dioxide is transported and stored. This paper reviews selected reports that specifically provide threshold amount fraction limits for impurities in carbon dioxide for the purpose of transport and storage, with rationales for these limits. A carbon dioxide purity specification is provided (including threshold amount fractions of impurities) on the basis of the findings, as well as recommendations on further work required to develop a suitable gas metrology infrastructure to support these measurements including primary reference materials, sampling methods, and instruments for performing purity analysis. These recommendations provide important guidance to operators and gas analysis laboratories for performing quality assurance.
Enzyme-Assisted Aqueous Extraction of Cobia Liver Oil and Protein Hydrolysates with Antioxidant Activity
Authors: Wang Yu-Hsiang , Kuo Chia-Hung , Lee Chien-Liang , Kuo Wen-Cheng , Tsai Mei-Ling , Sun Pei-Pei
Published: November 2020

Cobia, Rachycentron canadum, is a medium-size marine fish with emerging global potential for offshore aquaculture. The processing waste, cobia liver, is a raw material rich in polyunsaturated fatty acid oils. In this study, an environmentally friendly green process, aqueous extraction (AE), was used to extract the cobia liver oil. The effect of cooking time and substrate water ratio on the oil extractability was investigated herein. The cooking time of 15 min, and substrate water ratio of 1:2 obtained the highest extraction efficiency. However, the oil extractability was only 18.8%. Thus, enzyme-assisted aqueous extraction (EAAE) was used to increase oil extractability and recovery of protein hydrolysates. The commercial proteases—including alcalase, papain, trypsin, and pepsin—were employed in pretreated cobia liver in order to increase oil release during AE. The EAAE results showed that maximum oil extractability was 38% by papain pretreatment. EAAE greatly improved the extraction efficiency; the oil extractability was double than that of AE (18.8%). The fatty acid profiles revealed that ω-3 polyunsaturated fatty acid contents of extracted oil obtained from AE and EAAE were 21.3% and 19.5%, respectively. Besides, the cobia liver hydrolysates obtained from EAAE by alcalase, papain, pepsin, and trypsin pretreatment showed scavenge DPPH radical activity with EC50 values of 0.92, 1.03, 0.83, and 0.53 mg, respectively. After in vitro simulated gastrointestinal digestion, the protein hydrolysates exhibited scavenge DPPH radical activity with EC50 values of 1.15, 1.55, 0.98, and 0.76 mg for alcalase, papain, pepsin, and trypsin, respectively. The study showed that the EAAE process can be used for extracting fish oil from fish waste while simultaneously obtaining the protein hydrolysates with antioxidant activity.
Green Synthesized Palladium Coated Titanium Nanotube Arrays for Simultaneous Azo-Dye Degradation and Hydrogen Production
Authors: Lin Yuan-Chung , Chen Chia-Hung , Chen Kang-Shin , Peng Yen-Ping , Lin Yung-Chang , Huang Shih-Wei , Huang Chien-Er , Lai Hsiao-Wu , Li Hsing-Wang
Published: November 2020

In this study, electrodes of titanium dioxide nanotube arrays (TNAs) were successfully synthesized by applying the anodic oxidation etching method, as well as the use of green synthetic technology to add reducing agents of tea or coffee to reduce metal palladium from palladium chloride. Synthesis of palladium modified TNAs (Pd/TNAs) was conducted by the microwave hydrothermal method after the metal palladium was reduced. In order to identify the surface structure, light absorption and elemental composition, TNAs and Pd/TNAs were characterized by X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD). Furthermore, to test the photocurrent density, electron resistance, and hydroxyl radicals by I-t plot, electrochemistry impedance spectroscopy (EIS), and electron paramagnetic resonance (EPR) were investigated. The photocurrent (4.0 mA/cm2) of Pd/TNAs-C (using coffee as the reducing agent) at +1.0 V (vs. Ag/AgCl) was higher than that of the pure TNAs (1.5 mA/cm2), illustrating that Pd/TNAs-C can effectively separate photogenerated electrons and holes. Pd/TNAs is a favorable material as a photoanode for the photoelectrochemical (PEC) removal of organic pollutants in wastewater.
A Tale of Two Tiles: Characterization of Floor Tiles from the Nineteenth-Century Akko Tower Shipwreck (Israel)
Authors: Inberg Alexandra , Ashkenazi Dana , Feldman Yishai , Dvir Omri , Cvikel Deborah
Published: November 2020

Fragments of decorated floor tiles were retrieved from the Akko Tower shipwreck, Israel. Most tiles were made of bright brown fired clay with a white glaze decorated with colored stenciled motifs (Type A); and others consisted of a red-brown fired clay body, coated with a brown pigment covered with transparent brown glaze (Type B). This study aimed to characterize the two tile types; to reveal information concerning the manufacturing process; and to determine the origin of their raw material. A multidisciplinary approach was used, including light microscopy, SEM-EDS, electron probe microanalysis with wavelength-dispersive X-ray spectroscopy (EPMA-WDS), XRD, Raman spectroscopy, and time-of-flight secondary ion mass spectrometry (TOF-SIMS) analyses. The characterization of both tile types demonstrated the use of different raw materials. The Type A tiles were covered with tin-opacified majolica glaze and colored with various mixtures of pigments. The blue color was due to pigment rich in cobalt; the yellow color was due to Naples yellow and lead-tin yellow I minerals; and the green, orange, and brown colors were all prepared by mixing the Naples yellow pigment with different minerals. These majolica glaze tiles were probably manufactured in Sicily. The brown coating of the Type B tiles was due to pigment rich in lead and iron minerals. These tiles were produced with different manufacturing processes, and apparently made in France.
Electrodeposition of Ni-W/CNT Composite Plating and Its Potential as Coating for PEMFC Bipolar Plate
Authors: Park Jae-Hyeok , Wada Tatsuya , Naruse Yuto , Hagio Takeshi , Kamimoto Yuki , Ryoichi Ichino
Published: November 2020

In this study, Ni-W/carbon nanotube (CNT) composite platings are electrodeposited onto steel plate as a possible coating material for the polymer electrolyte membrane fuel cell (PEMFC) bipolar plate, which requires high corrosion resistance under acidic environment and low contact resistance. The dispersibility of CNT in the plating bath is improved by surface modification of CNT through hydrothermal treatment in mixed acid solution. The change in electrodeposition behavior of Ni-W plating by CNT addition is investigated by cathodic polarization measurement. The corrosion resistance under acidic environment is evaluated using 0.5M H2SO4 solution and contact resistance of the composite platings is measured and compared with Ni and Ni-W plating. The surface modification of CNT through hydrothermal treatment is found to increase the CNT content in the Ni-W/CNT composite plating up to 0.33 mass.% and sufficient incorporation of hydrothermally treated CNT in Ni-W plating results in low contact resistance and enhanced corrosion resistance than pristine Ni-W plating.
Electrochemical Properties and Chemical Oxygen Demand Depending on the Thickness of Boron-Doped Diamond
Authors: Song Chang Weon , You Mi Young , Lee Jae Myung , Cho Dae-Seung , Song Pung Keun
Published: November 2020

In this study, boron-doped diamond (BDD) film was deposited by hot-filament chemical vapor deposition (HFCVD) using acetone as the carbon source and trimethyl borate (TMB) as the boron source with the aim of lowering the manufacturing cost of BDD electrodes. The BDD film was deposited for 12 and 60 h to observe changes in the morphological behavior of the film as well as subsequent changes in the electrochemical properties. The morphology of the BDD film was not affected by the deposition time, but the thickness increased with increasing deposition time. As the deposition time increased, the deposition rate of the BDD film did not increase or decrease; rather, it remained constant at 100 nm/h. As the thickness of the BDD film increased, an increase in the potential window was observed. On the other hand, no distinct change was observed in the electrochemical activation and catalytic activity depending on the thickness, and there were not many differences. Chemical oxygen demand (COD) was measured to determine the practical applicability of the deposited BDD film. Unlike the potential window, the COD removal rate was almost the same and was not affected by the increase in the thickness of the BDD film. Both films under the two deposition conditions showed a high removal rate of 90% on average. This study confirms that BDD electrodes are much more useful for water treatment than the existing electrodes.
Recommendations for Integrating a P300-Based Brain–Computer Interface in Virtual Reality Environments for Gaming: An Update
Authors: Cattan Grégoire , Andreev Anton , Visinoni Etienne
Published: November 2020

The integration of a P300-based brain–computer interface (BCI) into virtual reality (VR) environments is promising for the video games industry. However, it faces several limitations, mainly due to hardware constraints and limitations engendered by the stimulation needed by the BCI. The main restriction is still the low transfer rate that can be achieved by current BCI technology, preventing movement while using VR. The goal of this paper is to review current limitations and to provide application creators with design recommendations to overcome them, thus significantly reducing the development time and making the domain of BCI more accessible to developers. We review the design of video games from the perspective of BCI and VR with the objective of enhancing the user experience. An essential recommendation is to use the BCI only for non-complex and non-critical tasks in the game. Also, the BCI should be used to control actions that are naturally integrated into the virtual world. Finally, adventure and simulation games, especially if cooperative (multi-user), appear to be the best candidates for designing an effective VR game enriched by BCI technology.
Graphene Synthesis by Ultrasound Energy-Assisted Exfoliation of Graphite in Various Solvents
Authors: Gürünlü Betül , Taşdelen-Yücedağ Çiğdem , Bayramoğlu Mahmut
Published: November 2020

The liquid-phase exfoliation (LPE) method has been gaining increasing interest by academic and industrial researchers due to its simplicity, low cost, and scalability. High-intensity ultrasound energy was exploited to transform graphite to graphene in the solvents of dimethyl sulfoxide (DMSO), N,N-dimethyl formamide (DMF), and perchloric acid (PA) without adding any surfactants or ionic liquids. The crystal structure, number of layers, particle size, and morphology of the synthesized graphene samples were characterized by X-ray diffraction (XRD), atomic force microscopy (AFM), ultraviolet visible (UV–vis) spectroscopy, dynamic light scattering (DLS), and transmission electron microscopy (TEM). XRD and AFM analyses indicated that G-DMSO and G-DMF have few layers while G-PA has multilayers. The layer numbers of G-DMSO, G-DMF, and G-PA were determined as 9, 10, and 21, respectively. By DLS analysis, the particle sizes, polydispersity index (PDI), and zeta potential of graphene samples were estimated in a few micrometers. TEM analyses showed that G-DMSO and G-DMF possess sheet-like fewer layers and also, G-PA has wrinkled and unordered multilayers.
Influence of Stabilizing Ion Content on the Structure, Photoluminescence and Biological Properties of Zr1–xEuxO2–0.5x Nanoparticles
Authors: Bugrov Alexander N. , Smyslov Ruslan Yu. , Zavialova Anastasia Yu. , Kopitsa Gennady P. , Khamova Tamara V. , Kirilenko Demid A. , Kolesnikov Ilya E. , Pankin Dmitrii V. , Baigildin Vadim A. , Licitra Christophe
Published: November 2020

Quasi-spherical nanoparticles of ZrO2 containing EuO1.5 from 2 to 15 mol.% were synthesized from the chlorides of the corresponding metals under hydrothermal conditions. The structural changes of Zr1–xEuxO2–0.5x (x = 0.02 ÷ 0.15) nanoparticles depending on the content of europium (III) ions were studied using the complementary methods (X-ray diffraction, electron microdiffraction, Raman and photoluminescence spectroscopy). It was shown that increasing the Eu3+ concentration in the Zr1–xEuxO2–0.5x nanoparticles leads to a transition from the equilibrium monoclinic zirconia phase to metastable tetragonal and cubic polymorphic modifications. In this case, the size of the nanoparticles decreases from 11.5 nm to 9 nm; the specific surface area grows from 80.2 to 111.3 m2/g, and the electrokinetic potential increases monotonously from −8.7 to 16.3 mV. The evolution of the phase composition of Zr1–xEuxO2-0.5x nanoparticles from monoclinic to tetragonal/cubic allomorphs with an increase in the molar fraction of stabilizer ions was correlated with changes in the sublevel structure of 5D0 → 7F2 and 5D0 → 7F4 optical transitions for Eu3+ in the luminescence spectra. Besides, for the nanoparticles obtained by hydrothermal synthesis from chlorides, the quantum efficiency does not exceed 3%. According to the M.T.T. assay, as a result of three-day human fibroblast cultivation in the aqueous dispersion of Zr1–xEuxO2–0.5x (x = 0.02 ÷ 0.15) nanoparticles, the proliferation activity of the cells is maintained, indicating that they do not have cytotoxic properties. Such nanoparticles can be used in organic–inorganic composites for medical applications in order to strengthen the polymer scaffolds and visualize changes in their structure within time.
Microwave-Assisted vs. Conventional Hydrothermal Synthesis of MoS2 Nanosheets: Application towards Hydrogen Evolution Reaction
Authors: Solomon Getachew , Mazzaro Raffaello , Morandi Vittorio , Concina Isabella , Vomiero Alberto
Published: November 2020

Molybdenum sulfide (MoS2) has emerged as a promising catalyst for hydrogen evolution applications. The synthesis method mainly employed is a conventional hydrothermal method. This method requires a longer time compared to other methods such as microwave synthesis methods. There is a lack of comparison of the two synthesis methods in terms of crystal morphology and its electrochemical activities. In this work, MoS2 nanosheets are synthesized using both hydrothermal (HT-MoS2) and advanced microwave methods (MW-MoS2), their crystal morphology, and catalytical efficiency towards hydrogen evolution reaction (HER) were compared. MoS2 nanosheet is obtained using microwave-assisted synthesis in a very short time (30 min) compared to the 24 h hydrothermal synthesis method. Both methods produce thin and aggregated nanosheets. However, the nanosheets synthesized by the microwave method have a less crumpled structure and smoother edges compared to the hydrothermal method. The as-prepared nanosheets are tested and used as a catalyst for hydrogen evolution results in nearly similar electrocatalytic performance. Experimental results showed that: HT-MoS2 displays a current density of 10 mA/cm2 at overpotential (−280 mV) compared to MW-MoS2 which requires −320 mV to produce a similar current density, suggesting that the HT-MoS2 more active towards hydrogen evolutions reaction.
Mesomorphic, Optical and DFT Aspects of Near to Room-Temperature Calamitic Liquid Crystal
Authors: Zaki Ayman A. , Hagar Mohamed , Alnoman Rua B. , Jaremko Mariusz , Emwas Abdul-Hamid , Ahmed Hoda A.
Published: November 2020

A new liquid crystalline, optical material-based Schiff base core with a near to room-temperature mesophase, (4-methoxybenzylideneamino)phenyl oleate (I), was prepared from a natural fatty acid derivative, and its physical and chemical properties investigated by experimental and theoretical approaches. The molecular structure was confirmed by elemental analysis, FT-IR (Fourier-Transform-Infrared Spectroscopy) and NMR (nuclear magnetic resonance) spectroscopy. Optical and mesomorphic activities were characterized by differential scanning calorimetry (DSC) and polarized optical microscopy (POM). The results show that compound (I) exhibits an enantiotropic monomorphic phase comprising a smectic A phase within the near to room-temperature range. Ordinary and extraordinary refractive indices as well as birefringence with changeable temperatures were analyzed. Microscopic and macroscopic order parameters were also calculated. Theoretical density functional theory (DFT) calculations were carried out to estimate the geometrical molecular structures of the prepared compounds, and the DFT results were used to illustrate the mesomorphic results and optical characteristics in terms of their predicted data. Three geometrical isomers of the prepared compound were investigated to predict the most stable isomer. Many parameters were affected by the geometrical isomerism such as aspect ratio, planarity, and dipole moment. Thermal parameters of the theoretical calculations revealed that the highest co-planar aromatic core is the most stable conformer.
Autonomous Detection and Classification of PI-RADS Lesions in an MRI Screening Population Incorporating Multicenter-Labeled Deep Learning and Biparametric Imaging: Proof of Concept
Authors: Winkel David J. , Wetterauer Christian , Matthias Marc Oliver , Lou Bin , Shi Bibo , Kamen Ali , Comaniciu Dorin , Seifert Hans-Helge , Rentsch Cyrill A. , Boll Daniel T.
Published: November 2020

Background: Opportunistic prostate cancer (PCa) screening is a controversial topic. Magnetic resonance imaging (MRI) has proven to detect prostate cancer with a high sensitivity and specificity, leading to the idea to perform an image-guided prostate cancer (PCa) screening; Methods: We evaluated a prospectively enrolled cohort of 49 healthy men participating in a dedicated image-guided PCa screening trial employing a biparametric MRI (bpMRI) protocol consisting of T2-weighted (T2w) and diffusion weighted imaging (DWI) sequences. Datasets were analyzed both by human readers and by a fully automated artificial intelligence (AI) software using deep learning (DL). Agreement between the algorithm and the reports—serving as the ground truth—was compared on a per-case and per-lesion level using metrics of diagnostic accuracy and k statistics; Results: The DL method yielded an 87% sensitivity (33/38) and 50% specificity (5/10) with a k of 0.42. 12/28 (43%) Prostate Imaging Reporting and Data System (PI-RADS) 3, 16/22 (73%) PI-RADS 4, and 5/5 (100%) PI-RADS 5 lesions were detected compared to the ground truth. Targeted biopsy revealed PCa in six participants, all correctly diagnosed by both the human readers and AI. Conclusions: The results of our study show that in our AI-assisted, image-guided prostate cancer screening the software solution was able to identify highly suspicious lesions and has the potential to effectively guide the targeted-biopsy workflow.
A Novel DSP Truncating Variant in a Family with Episodic Myocardial Injury in the Course of Arrhythmogenic Cardiomyopathy—A Possible Role of a Low Penetrance NLRP3 Variant
Authors: Chmielewski Przemysław , Truszkowska Grażyna T. , Kukla Piotr , Zakrzewska-Koperska Joanna , Śpiewak Mateusz , Stępień-Wojno Małgorzata , Bilińska Maria , Lutyńska Anna , Płoski Rafał , Bilińska Zofia T.
Published: November 2020

Mono-allelic dominant mutations in the desmoplakin gene (DSP) have been linked to known cardiac disorders, such as arrhythmogenic right ventricular cardiomyopathy and dilated cardiomyopathy. During the course of DSP cardiomyopathy, episodes of acute myocardial injury may occur. While their mechanisms remain unclear, myocarditis has been postulated as an underlying cause. We report on an adolescent girl with arrhythmogenic biventricular cardiomyopathy and three acute myocarditis-like episodes in whom we found a novel truncating DSP variant accompanied by a known low penetrance R490K variant in the NLRP3. Upon family screening, other carriers of the DSP variant have been identified in whom only mild cardiac abnormalities were found. We hypothesized that the uncommon course of cardiomyopathy in the proband as well as striking discrepancies in the phenotype observed in her family may be explained by the co-existence of her low penetrance genetic autoinflammatory predisposition.
Enhanced Multimodal Biometric Recognition Based upon Intrinsic Hand Biometrics
Authors: Haider Syed Aqeel , Rehman Yawar , Ali S. M. Usman
Published: November 2020

In the proposed study, we examined a multimodal biometric system having the utmost capability against spoof attacks. An enhanced anti-spoof capability is successfully demonstrated by choosing hand-related intrinsic modalities. In the proposed system, pulse response, hand geometry, and finger–vein biometrics are the three modalities of focus. The three modalities are combined using a fuzzy rule-based system that provides an accuracy of 92% on near-infrared (NIR) images. Besides that, we propose a new NIR hand images dataset containing a total of 111,000 images. In this research, hand geometry is treated as an intrinsic biometric modality by employing near-infrared imaging for human hands to locate the interphalangeal joints of human fingers. The L2 norm is calculated using the centroid of four pixel clusters obtained from the finger joint locations. This method produced an accuracy of 86% on the new NIR image dataset. We also propose finger–vein biometric identification using convolutional neural networks (CNNs). The CNN provided 90% accuracy on the new NIR image dataset. Moreover, we propose a robust system known as the pulse response biometric against spoof attacks involving fake or artificial human hands. The pulse response system identifies a live human body by applying a specific frequency pulse on the human hand. About 99% of the frequency response samples obtained from the human and non-human subjects were correctly classified by the pulse response biometric. Finally, we propose to combine all three modalities using the fuzzy inference system on the confidence score level, yielding 92% accuracy on the new near-infrared hand images dataset.
A State of the Art of the Multilevel Inverters with Reduced Count Components
Authors: Hassan Alaaeldien , Yang Xu , Chen Wenjie , Houran Mohamad Abou
Published: November 2020

Multilevel inverters (MLIs) have become a trend in the field of DC/AC inverters and one of the main requirements in many of the industrial applications. MLIs spread in the academic research field and replaced the conventional inverters due to the several advantages that these topologies presented over the conventional inverters, as follows. (1) Operate with a high number of steps in the output voltage waveform, which helps in reducing the level of harmonics and presents fine and clear waveforms; furthermore, reduce the voltage stress on the switching devices and gives it a long lifetime and more reliability. (2) MLIs have a low rating of the switching devices, which has a noticeable role in reducing the system cost. (3) MLIs can be operated at both higher and lower switching frequencies, which reduces the level of power losses and enhances the overall efficiency. The main problem that faces the researchers in the multilevel inverters field is to design a topology that uses the optimum number of components to ensure the low cost and obtain a high efficiency. This paper presents a description of different topologies of MLIs that were investigated in the last two decades to show the pros and cons of each topology. Also a set of performance parameters that were used to measure the effectiveness of the MLI topologies have been discussed.
Acceleration of the Multi-Level Fast Multipole Algorithm Using K-Means Clustering
Authors: Yun Dal-jae , Jung Haewon , Kang Hoon , Yang Woo-Yong , Seo Dong-Wook
Published: November 2020

The multilevel fast multipole algorithm (MLFMA) using K-means clustering to accelerate electromagnetic scattering analysis for large complex targets is presented. By replacing the regular cube grouping with the K-means clustering, the addition theorem is more accurately approximated. The convergence rate of an iterative solver is thus improved significantly. However, irregular centroid locations as a result of the K-means clustering increase the amount of explicit transfer function calculations, compared with the regular cubes. In the MLFMA, a multilevel hierarchical structure is applied to the finite multipole method (FMM) to reduce transfer function calculations. Therefore, the MLFMA is suitable for applying K-means clustering. Simulation results with both canonical and realistic targets show an improvement in the computation time of the proposed algorithm.
Coordinated Power Sharing in Islanding Microgrids for Parallel Distributed Generations
Authors: Baneshi Ehsan , Kolahduzloo Hasan , Ebrahimi Javad , Mahmoudian Mehrdad , Pouresmaeil Edris , Rodrigues Eduardo M. G.
Published: November 2020

Optimal power sharing between parallel inverters and the demand load in microgrids is challenging and particularly critical for power grids in islanding operation. This paper introduces a novel control approach for managing parallel distributed power sources in the presence of variable load in islanding regime. The proposed scheme is based on the modified sliding mode control (MSMC) which is combined with the optimal Riccati control method to achieve convergence at the slip level with higher accuracy. The mathematical principles of the network equations are derived and its stability is obtained using the Lyapunov function. The MSMC simulation results are discussed in relation to the conventional droop method, while the laboratory evaluation was carried out to characterize its dynamic and static response. The results show that the proposed scheme control is able to manage the distributed power generation for static and dynamic load scenarios, and as such, guarantying microgrid frequency stability.