bluuebunny/crossref_metadata_2025 huggingface dataset:
Coating Deterioration and Underlying Metal Corrosion Processes in Water-Line Area: Role of DACs
Authors: Chen Zhiwei , Zhang Wei , Zhan Yi , Lei Bing , Sun Tianying , Li Weihua
Published: July 2020

Water-line corrosion is a highly concentrated type of localized corrosion. The conventional single electrode method is limited in its ability to obtain the kinetic information of the corrosion occurrence and development processes. Herein, the coating deterioration and underlying metal corrosion processes in water-line area were studied by a small wire beam electrode to monitor the current density distribution. The distance between each electrode was very small (interval: 0.3 mm), thus facilitating it to approach the practical metal component with a continuous surface. The results showed that cathodic and anodic sites tended to be weak points of the coating at the initial stage. With the continuous degradation of the coating, the cathodic zone tended to occur in the above the anodic zone due to the effect of differential aeration cells (DACs). Subsequently, the cathodic zone expanded to the waterline and the polarity reversed to the anodic zone, causing the coating to peel and blister continuously from the bottom up. When the cathodic zone extended to the gas phase area above the water line, this area became the strongest cathodic zone under the action of the thin liquid film, thus significantly accelerating the corrosion of the base metal at the bottom. The present study aims to achieve an in-depth understanding of coating deterioration and underlying metal corrosion processes in the water-line area, providing a new means of directly visualizing the role of DACs played in water line corrosion.
Top Coating Anti-Erosion Performance Analysis in Wind Turbine Blades Depending on Relative Acoustic Impedance. Part 1: Modelling Approach
Authors: Domenech Luis , Renau Jordi , Šakalytė Asta , Sánchez Fernando
Published: July 2020

Top coating are usually moulded, painted or sprayed onto the wind blade Leading-Edge surface to prevent rain erosion due to transverse repeated droplet impacts. Wear fatigue failure analysis based on Springer model has been widely referenced and validated to quantitatively predict damage initiation. The model requires liquid, coating and substrate speed of sound measurements as constant input parameters to define analytically the shockwave progression due to their relative vibro-acoustic properties. The modelling assumes a pure elastic material behavior during the impact event. Recent coating technologies applied to prevent erosion are based on viscoelastic materials and develop high-rate transient pressure build-up and a subsequent relaxation in a range of strain rates. In order to analyze the erosion performance by using Springer model, appropriate impedance characterization for such viscoelastic materials is then required and represents the main objective of this work to avoid lack of accuracy. In the first part of this research, it is proposed a modelling methodology that allows one to evaluate the frequency dependent strain-stress behavior of the multilayer coating system under single droplet impingement. The computational tool ponders the operational conditions (impact velocity, droplet size, layer thickness, etc.) with the appropriate variable working frequency range for the speed of sound measurements. The second part of this research defines in a complementary paper, the ultrasonic testing characterization of different viscoelastic coatings and the methodology validation. The modelling framework is then used to identify suitable coating and substrate combinations due to their acoustic matching optimization and to analyze the anti-erosion performance of the coating protection system.
Investigation of Ancient Architectural Painting from the Taidong Tomb in the Western Qing Tombs, Hebei, China
Authors: Fu Peng , Teri Ge-Le , Li Jing , Li Jia-Xin , Li Yu-Hu , Yang Hong
Published: July 2020

The Taidong Tomb in the imperial tombs of the Qing dynasties has great aesthetic value and a rich history. In this study, we conducted the first investigation ever performed on the raw materials used in the paintings in the Taidong Tomb. Energy dispersive X-ray spectroscopy (EDX), polarized light microscopy (PLM), X-ray diffraction (XRD), micro-Raman spectroscopy (m-RS), Fourier-transform infrared spectroscopy (FTIR) and pyrolysis–gas chromatography–mass spectrometry (Py-GC/MS) were used to comprehensively analyze the painting of Long’en Hall, Xipei Hall and the ceiling of Minglou. In the conclusion of the study, the paintings were found to contain natural mineral and synthetic pigments, including atacamite (Cu2Cl(OH)3), azurite (2CuCO3·Cu(OH)2), vermilion (HgS), carbon black (C), anglesite (PbSO4), white lead (2PbCO3·Pb(OH)2), synthetic emerald green (Cu(CH3COO)2·3Cu(AsO2)2) and ultramarine ((Na,Ca)8(AlSiO4)6(SO4,S,Cl)2). This allows us to conclude that some of the architectural paintings were repainted in the mid-to-late 19th century. The mortar layer may consist of brick ash (albite, gismondine), lime water, tung oil and flour. The fiber layer material may be ramie. Researching the raw materials of the paintings in the Taidong Tomb is of great value because it provides scientific data for the future preservation of the paintings in the tomb.
Preparation of High Hardness Transparent Coating with Controllable Refractive Index by Sol-Gel Technology
Authors: Liu Xiaolin , Wang Yansong , Bai Tao
Published: July 2020

SiO2/ZrO2 and SiO2/ZrO2/Al2O3 composite organic–inorganic coatings were prepared by the sol-gel technology. The structure of the coating was characterized by IR, particle size analyzer, SEM, and AFM, respectively. The results showed that ZrO2, SiO2 (inorganic component), and siloxane had undergone a hydrolytic condensation reaction, and the composite organic–inorganic coatings were formed with -O-M-O- (M is Si, Zr) as molecular skeleton network structure. Adding an appropriate ratio of ZrO2 sol, no agglomeration and phase separation occurred, which could significantly improve the refractive index, hardness, and light transmittance of the coatings. Al2O3 sol could greatly improve the friction resistance of the composite organic–inorganic coatings, and the Bayer ratio of the composite coatings could reach 7.86. By adjusting the proportioning of composite sol solution, the refractive index of the composite transparent coatings could be controlled from 1.52 to 1.65.
Theoretical Analysis of Roll-Over-Web Surface Thin Layer Coating
Authors: Manzoor Tareq , Zafar Muhammad , Iqbal Shaukat , Nazar Kashif , Ali Muddassir , Saleem Mahmood , Manzoor Sanaullah , Kim Woo Young
Published: July 2020

This study presents the theoretical investigation of a roll-over thin layer formation under the lubrication approximation theory. The set of differential equations derived by lubrication approximation is solved by the optimal homotopy asymptotic method (OHAM) to obtain precise expressions for pressure and velocity gradients. Critical quantities such as velocity, pressure gradient, and coating layer depth are numerically estimated. The impact of parameters affecting the coating and layer formation is revealed in detail. Results indicate that the transport properties of the higher-grade fluid play an essential role in regulating velocity, pressure, and the final coated region. Moreover, couple stress effects on the properties of fluid particles to be coated on roller-surface have also been studied.
Natural vs. Synthetic Zeolites
Authors: Król Magdalena
Published: July 2020

This brief review article describes the structure, properties and applications of natural and synthetic zeolites, with particular emphasis on zeolites obtained from natural or waste materials. Certainly, such short work does not exhaust the complexity of the problem, but it sheds light on some outstanding issues on this subject.
The Convolutional Multiple Whole Profile (CMWP) Fitting Method, a Global Optimization Procedure for Microstructure Determination
Authors: Ribárik Gábor , Jóni Bertalan , Ungár Tamás
Published: July 2020

The analysis of line broadening in X-ray and neutron diffraction patterns using profile functions constructed on the basis of well-established physical principles and TEM observations of lattice defects has proven to be a powerful tool for characterizing microstructures in crystalline materials. These principles are applied in the convolutional multiple-whole-profile (CMWP) procedure to determine dislocation densities, crystallite size, stacking fault and twin boundary densities, and intergranular strains. The different lattice defect contributions to line broadening are separated by considering the hkl dependence of strain anisotropy, planar defect broadening and peak shifts, and the defect dependent profile shapes. The Levenberg–Marquardt (LM) peak fitting procedure can be used successfully to determine crystal defect types and densities as long as the diffraction patterns are relatively simple. However, in more complicated cases like hexagonal materials or multiple-phase patterns, using the LM procedure alone may cause uncertainties. Here, we extended the CMWP procedure by including a Monte Carlo statistical method where the LM and a Monte Carlo algorithm were combined in an alternating manner. The updated CMWP procedure eliminated uncertainties and provided global optimized parameters of the microstructure in good correlation with electron microscopy methods.
A Comparative Phylogeographic Approach to Facilitate Recovery of an Imperiled Freshwater Mussel (Bivalvia: Unionida: Potamilus inflatus)
Authors: Smith Chase H. , Johnson Nathan A.
Published: July 2020

North American freshwaters are among the world’s most threatened ecosystems, and freshwater mussels are among the most imperiled inhabiting these systems. A critical aspect of conservation biology is delineating patterns of genetic diversity, which can be difficult when a taxon has been extirpated from a significant portion of its historical range. In such cases, evaluating conservation and recovery options may benefit by using surrogate species as proxies when assessing overall patterns of genetic diversity. Here, we integrate the premise of surrogate species into a comparative phylogeographic framework to hypothesize genetic relationships between extant and extirpated populations of Potamilus inflatus by characterizing genetic structure in co-distributed congeners with similar life histories and dispersal capabilities. Our mitochondrial and nuclear sequence data exhibited variable patterns of genetic divergence between Potamilus spp. native to the Mobile and Pascagoula + Pearl + Pontchartrain (PPP) provinces. However, hierarchical Approximate Bayesian Computation indicated that the diversification between Mobile and PPP clades was synchronous and represents a genetic signature of a common history of vicariance. Recent fluctuations in sea-level appear to have caused Potamilus spp. in the PPP to form a single genetic cluster, providing justification for using individuals from the Amite River as a source of brood stock to re-establish extirpated populations of P. inflatus. Future studies utilizing eDNA and genome-wide molecular data are essential to better understand the distribution of P. inflatus and establish robust recovery plans. Given the imperilment status of freshwater mussels globally, our study represents a useful methodology for predicting relationships among extant and extirpated populations of imperiled species.
Entropy-Based Solutions for Ecological Inference Problems: A Composite Estimator
Authors: Bernardini Papalia Rosa , Fernandez Vazquez Esteban
Published: July 2020

Information-based estimation techniques are becoming more popular in the field of Ecological Inference. Within this branch of estimation techniques, two alternative approaches can be pointed out. The first one is the Generalized Maximum Entropy (GME) approach based on a matrix adjustment problem where the only observable information is given by the margins of the target matrix. An alternative approach is based on a distributionally weighted regression (DWR) equation. These two approaches have been studied so far as completely different streams, even when there are clear connections between them. In this paper we present these connections explicitly. More specifically, we show that under certain conditions the generalized cross-entropy (GCE) solution for a matrix adjustment problem and the GME estimator of a DWR equation differ only in terms of the a priori information considered. Then, we move a step forward and propose a composite estimator that combines the two priors considered in both approaches. Finally, we present a numerical experiment and an empirical application based on Spanish data for the 2010 year.
The Battle between the Correct and Mirror Writings of a Digit in Children’s Recognition Memory
Authors: Fischer Jean-Paul , Luxembourger Christophe
Published: July 2020

Recent research into character reversals in writings produced by occidental children has shown that they mainly reverse the left-oriented digits (1, 2, 3, 7, and 9) and therefore appear to apply a right-orienting rule. But do they produce similar reversal errors when asked to recognize the digits? In an experiment, based on eye-tracking observations of 50 children (Mage = 5.4 years), children had to point towards a target digit in a 2 × 2 matrix also containing three distractor digits, one of which was the mirror-reversed writing of the correctly written target digit. This recognition task led to a true “battle” in children’s memory between the two writings of the target digit. This battle is shown in the graphical abstract that represents a heat map from a sub-sample of children (on the left side) and the fixation points map from an individual child (on the right side). Rather than following the predicted right-orienting rule, the children’s responses appeared to be biased towards digits in the right-hand column of the 2 × 2 matrices (when the reversed target digit was not in the same column as the correctly written target digit). As a whole, these findings support the hypotheses that many 4- to 6-year-old’s representations of the digit writings are unoriented in their memory and that these children may adopt different solutions to overcome this lack of orientation depending on whether they write or read.
Packet Preprocessing in CNN-Based Network Intrusion Detection System
Authors: Jo Wooyeon , Kim Sungjin , Lee Changhoon , Shon Taeshik
Published: July 2020

The proliferation of various connected platforms, including Internet of things, industrial control systems (ICSs), connected cars, and in-vehicle networks, has resulted in the simultaneous use of multiple protocols and devices. Chaotic situations caused by the usage of different protocols and various types of devices, such as heterogeneous networks, implemented differently by vendors renders the adoption of a flexible security solution difficult, such as recent deep learning-based intrusion detection system (IDS) studies. These studies optimized the deep learning model for their environment to improve performance, but the basic principle of the deep learning model used was not changed, so this can be called a next-generation IDS with a model that has little or no requirements. Some studies proposed IDS based on unsupervised learning technology that does not require labeled data. However, not using available assets, such as network packet data, is a waste of resources. If the security solution considers the role and importance of the devices constituting the network and the security area of the protocol standard by experts, the assets can be well used, but it will no longer be flexible. Most deep learning model-based IDS studies used recurrent neural network (RNN), which is a supervised learning model, because the characteristics of the RNN model, especially when the long-short term memory (LSTM) is incorporated, are better configured to reflect the flow of the packet data stream over time, and thus perform better than other supervised learning models such as convolutional neural network (CNN). However, if the input data induce the CNN’s kernel to sufficiently reflect the network characteristics through proper preprocessing, it could perform better than other deep learning models in the network IDS. Hence, we propose the first preprocessing method, called “direct”, for network IDS that can use the characteristics of the kernel by using the minimum protocol information, field size, and offset. In addition to direct, we propose two more preprocessing techniques called “weighted” and “compressed”. Each requires additional network information; therefore, direct conversion was compared with related studies. Including direct, the proposed preprocessing methods are based on field-to-pixel philosophy, which can reflect the advantages of CNN by extracting the convolutional features of each pixel. Direct is the most intuitive method of applying field-to-pixel conversion to reflect an image’s convolutional characteristics in the CNN. Weighted and compressed are conversion methods used to evaluate the direct method. Consequently, the IDS constructed using a CNN with the proposed direct preprocessing method demonstrated meaningful performance in the NSL-KDD dataset.
Design of a Low-Cost Configurable Acoustic Sensor for the Rapid Development of Sound Recognition Applications
Authors: Alsina-Pagès Rosa Maria , Hervás Marcos , Duboc Leticia , Carbassa Jordi
Published: July 2020

Concerned about the noise pollution in urban environments, the European Commission (EC) has created an Environmental Noise Directive 2002/49/EC (END) requiring Member states to publish noise maps and noise management plans every five years for cities with a high density of inhabitants, major roads, railways and airports. The END also requires the noise pressure levels for these sources to be presented independently. Currently, data measurements and the representations of the noise pressure levels in such maps are performed semi-manually by experts. This process is time and cost consuming, as well as limited to presenting only a static picture of the noise levels. To overcome these issues, we propose the deployment of Wireless Acoustic Sensor Networks with several nodes in urban environments that can enable the generation of real-time noise level maps, as well as detect the source of the sound thanks to machine learning algorithms. In this paper, we briefly review the state of the art of the hardware used in wireless acoustic applications and propose a low-cost sensor based on an ARM cortex-A microprocessor. This node is able to process machine learning algorithms for sound source detection in-situ, allowing the deployment of highly scalable sound identification systems.
A Comprehensive Review of Li-Ion Battery Materials and Their Recycling Techniques
Authors: Kim Hee-Je , Krishna TNV , Zeb Kamran , Rajangam Vinodh , Gopi Chandu V. V. Muralee , Sambasivam Sangaraju , Raghavendra Kummara Venkata Guru , Obaidat Ihab M.
Published: July 2020

In the context of constant growth in the utilization of the Li-ion batteries, there was a great surge in the quest for electrode materials and predominant usage that lead to the retiring of Li-ion batteries. This review focuses on the recent advances in the anode and cathode materials for the next-generation Li-ion batteries. To achieve higher power and energy demands of Li-ion batteries in future energy storage applications, the selection of the electrode materials plays a crucial role. The electrode materials, such as carbon-based, semiconductor/metal, metal oxides/nitrides/phosphides/sulfides, determine appreciable properties of Li-ion batteries such as greater specific surface area, a minimal distance of diffusion, and higher conductivity. Various classifications of the anode materials such as the intercalation/de- intercalation, alloy/de-alloy, and various conversion materials are illustrated lucidly. Further, the cathode materials, such as nickel-rich LiNixCoyMnzO2 (NCM), were discussed. NCM members such as NCM 333, NCM 523 that enabled to advance for NCM622 and NCM81are reported. The nanostructured materials bridged the gap in the realization of next-generation Li-ion batteries. Li-ion batteries’ electrode nanostructure synthesis, performance, and reaction mechanisms were considered with great concern. The serious effects of Li-ion batteries disposal need to be cut significantly to reduce the detrimental effect on the environment. Hence, the recycling of spent Li-ion batteries has gained much attention in recent years. Various recycling techniques and their effect on the electroactive materials are illustrated. The key areas covered in this review are anode and cathode materials and recent advances along with their recycling techniques. In light of crucial points covered in this review, it constitutes a suitable reference for engineers, researchers, and designers in energy storage applications.
Function Similarity Using Family Context
Authors: Black Paul , Gondal Iqbal , Vamplew Peter , Lakhotia Arun
Published: July 2020

Finding changed and similar functions between a pair of binaries is an important problem in malware attribution and for the identification of new malware capabilities. This paper presents a new technique called Function Similarity using Family Context (FSFC) for this problem. FSFC trains a Support Vector Machine (SVM) model using pairs of similar functions from two program variants. This method improves upon previous research called Cross Version Contextual Function Similarity (CVCFS) e epresenting a function using features extracted not just from the function itself, but also, from other functions with which it has a caller and callee relationship. We present the results of an initial experiment that shows that the use of additional features from the context of a function significantly decreases the false positive rate, obviating the need for a separate pass for cleaning false positives. The more surprising and unexpected finding is that the SVM model produced by FSFC can abstract function similarity features from one pair of program variants to find similar functions in an unrelated pair of program variants. If validated by a larger study, this new property leads to the possibility of creating generic similar function classifiers that can be packaged and distributed in reverse engineering tools such as IDA Pro and Ghidra.
Glass-Ceramic Sealants for SOEC: Thermal Characterization and Electrical Resistivity in Dual Atmosphere
Authors: Javed Hassan , Sabato Antonio Gianfranco , Mansourkiaei Mohsen , Ferrero Domenico , Santarelli Massimo , Herbrig Kai , Walter Christian , Smeacetto Federico
Published: July 2020

A Ba-based glass-ceramic sealant is designed and tested for solid oxide electrolysis cell (SOEC) applications. A suitable SiO2/BaO ratio is chosen in order to obtain BaSi2O5 crystalline phase and subsequently favorable thermo-mechanical properties of the glass-ceramic sealant. The glass is analyzed in terms of thermal, thermo-mechanical, chemical, and electrical behavior. Crofer22APU-sealant-Crofer22APU joined samples are tested for 2000 h at 850 °C in a dual atmosphere test rig having reducing atmosphere of H2:H2O 50/50 (mol%) and under the applied voltage of 1.6 V. In order to simulate the SOEC dynamic working conditions, thermal cycles are performed during the long-term electrical resistivity test. The glass-ceramic shows promising behavior in terms of high density, suitable CTE, and stable electrical resistivity (106–107 Ω cm) under SOEC conditions. The SEM-EDS post mortem analysis confirms excellent chemical and thermo-mechanical compatibility of the glass-ceramic with Crofer22APU.
Modeling and Stability Analysis of Weak-Grid Tied Multi-DFIGs in DC-Link Voltage Control Timescale
Authors: Wang Dong , Chen Houquan , Huang Yunhui , Deng Xiangtian , Zhu Guorong
Published: July 2020

The DC-link voltage control (DVC) timescale (i.e., the frequency dynamics covering converter outer controls) instabilities in wind generation have gained increased attention recently. This paper presents DVC timescale modeling and stability analysis for multi doubly-fed induction generators (DFIGs) connected to weak AC grids. A reduced-order, small-signal model of a grid-tied multi-DFIG system, designed for DVC dynamics analysis, is firstly proposed. The model allows for the dynamic interactions among the DC-link voltage control, active power control (APC), terminal voltage control (TVC) and phase-locked loop (PLL). Eigenvalue and participation factor analyses are conducted to explore the potential instabilities and correlated critical factors for such a multi-machine system. The sensitivity studies find that instability can occur at high levels of power generations or low short-circuit ratio (SCR) conditions. In addition, the dominant mode is identified to be highly related to the PLL, and its modal damping is decreased when the bandwidths of PLLs in different generators are close. Detailed model-based time domain simulations verified the analysis above.
Ungulate Species and Abundance as well as Environmental Factors Determine the Probability of Terminal Shoot Browsing on Temperate Forest Trees
Authors: Kupferschmid Andrea Doris , Bütikofer Lukas , Hothorn Torsten , Schwyzer Andreas , Brang Peter
Published: July 2020

Ungulate browsing is a major factor influencing tree regeneration. However, it is unclear if the observed increase in ungulate abundance in Central Europe implies increased browsing, and which other factors influence the incidence of browsing. We investigated the impact of forty variables (site, climate, forest and ungulates) on the probability of leader shoot browsing of six tree species which are frequent in Switzerland. The analysis was based on a large dataset including 49 monitoring areas, each containing 25–64 circular plots, in which 10 to 130 cm tall seedlings were repeatedly assessed. Browsing probability was estimated for each plot and year by mixed effects logistic regression and used as a response in random forests to disentangle the influence of the explanatory variables. Browsing probability was positively correlated with ungulate density measures (number culled by hunting or found dead) for all six tree species. Where beyond roe deer, some red deer and/or chamois were present, the browsing probability was higher. Small timber tree stands had less browsing than young growth and thicket stands. Seedlings tended to be more frequently browsed in stands with >80% canopy shading. Browsing increased with increasing understory cover, independent of vegetation category. In conclusion, browsing is a multifactorial phenomenon and ungulate density estimates alone do not explain the whole browsing probability.
Impact of Stand Density and Tree Social Status on Aboveground Biomass Allocation of Scots Pine Pinus sylvestris L.
Authors: Wertz Bogdan , Bembenek Mariusz , Karaszewski Zbigniew , Ochał Wojciech , Skorupski Maciej , Strzeliński Paweł , Węgiel Andrzej , Mederski Piotr S.
Published: July 2020

Stand density changes due to aging and thinning interventions. At the same time, the social status of trees develops and varies due to different genetic conditions as well as access to nutrients and light. Trees growing in diverse conditions gain their social status in the stand, which, in the end, influences their development and biomass allocation. The objective of this research was to discover if stand density or tree social status has an impact on a tree’s aboveground biomass allocation. The study was carried out in five premature and five mature pine stands, growing in the same soil conditions. The selected sample stands had a different growing density, from low to high. In each sample stand, 10 trees were selected to represent a different social status, according to the Schädelin classification. There were 100 trees felled in total (50 in the premature stands and 50 in the mature stands), for which the dry biomass of the stem, living and dead branches, needles, and cones was determined. The results showed that stand density only had an impact on the branches’ biomass fraction but not the stem and foliage fractions, while social status had an impact on all the fractions. Dominant and codominant trees, as well as those with developed crowns, had a smaller share of the stem and higher share of branches in comparison with trees of a lower social status.
Effect of Substrate Characteristics on the Growth and Sporulation of Two Biocontrol Microorganisms during Solid State Cultivation
Authors: Lee Ga Young , Li Wenqi , Chirwa Ulalo M. , Shi Jian
Published: July 2020

Biocontrol agents are a group of naturally occurring organisms capable of interrupting the lifespan and suppressing the propagation of disease organisms. The use of biocontrol agents offers an environment-friendly and sustainable solution to the synthetic agrochemicals. In this study, we investigated parboiled rice and millets as substrates for spore production of two model biocontrol microorganisms (Bacillus pumilus and Streptomyces griseus) under solid state cultivation (SSC) conditions. The effects of cultivation parameters such as initial moisture content, water activity, and cultivation time on microbial growth and spore production were studied. Furthermore, texture profile analysis was performed to test the stress and strain curve and the hardness and stickiness of the substrates. The greatest spore production occurred at 50% moisture content with millets as a substrate, yielding a count of 1.34 × 108 spores/g-wet-substrate enumerated with plate count analysis and 1.70 × 108 events/g-wet-substrate using flow cytometry analysis. Substrate texture profile was highly correlative to the initial moisture content and substrate type and all proved to be essential process variables in controlling the bacterial growth and sporulation during SSC processes.
Assessment of the Economic and Health-Care Impact of COVID-19 (SARS-CoV-2) on Public and Private Dental Surgeries in Spain: A Pilot Study
Authors: Chamorro-Petronacci Cintia , Martin Carreras-Presas Carmen , Sanz-Marchena Adriana , A Rodríguez-Fernández María , María Suárez-Quintanilla José , Rivas-Mundiña Berta , Suárez-Quintanilla Juan , Pérez-Sayáns Mario
Published: July 2020

Objectives: The COVID-19 (SARS-CoV-2) pandemic is an ongoing public health challenge, also for the dentistry community. The main objective of this paper was to determine the economic and health-care impact of COVID-19 on dentists in the Autonomous Region of Galicia (Spain). Methods: This was a descriptive observational study in which the data was collected by means of a self-administered survey (from 1 April 2020 to 30 April 2020). Results: A total of 400 dentists from Galicia responded to the survey. Only 12.3% of the participants could obtain personal protective equipment (PPE) including FFP2 masks. Of the male respondents, 33.1% suffered losses >€15,000 compared to 19.4% of female respondents (OR = 3.121, p < 0.001). Economic losses seem to have contributed to the applications for economic help as 29.5% of the respondents who applied for this measure recorded losses in excess of €15,000 (p = 0.03). Patients complained more about the fact that only emergency care was available during the State of Alarm, in dental surgeries that do not work with insurance companies or franchises. Only 4 professionals tested positive, 50% of whom worked exclusively in private practice and the other 50% who practised in both private and public surgeries. Dentists who practise in the public sector saw more urgent patients per week than those practising in private surgeries (p = 0.013). Conclusions: The COVID-19 pandemic has had economic repercussions in dentistry as only urgent treatment was available during the State of Alarm. These repercussions seem to be higher in male participants, as the majority of the participants have revealed higher economic losses than females. The level of assistance has also been affected, reducing the number of treated patients, although this quantity has been different in private and public surgeries. By presenting these findings we look to highlight the role that dentists play in society in treating dental emergencies in our surgeries, and this must be recognised and addressed by the relevant authorities, who must provide PPEs as a priority to this group as well as providing special economic aid in accordance with the losses incurred by the sector.
Mapping the Potential Distribution of Major Tick Species in China
Authors: Yang Xin , Gao Zheng , Zhou Tianli , Zhang Jian , Wang Luqi , Xiao Lingjun , Wu Hongjuan , Li Sen
Published: July 2020

Ticks are known as the vectors of various zoonotic diseases such as Lyme borreliosis and tick-borne encephalitis. Though their occurrences are increasingly reported in some parts of China, our understanding of the pattern and determinants of ticks’ potential distribution over the country remain limited. In this study, we took advantage of the recently compiled spatial dataset of distribution and diversity of ticks in China, analyzed the environmental determinants of ten frequently reported tick species and mapped the spatial distribution of these species over the country using the MaxEnt model. We found that presence of urban fabric, cropland, and forest in a place are key determents of tick occurrence, suggesting ticks were likely inhabited close to where people live. Besides, precipitation in the driest month was found to have a relatively high contribution in mapping tick distribution. The model projected that theses ticks could be widely distributed in the Northwest, Central North, Northeast, and South China. Our results added new evidence on the potential distribution of a variety of major tick species in China and pinpointed areas with a high potential risk of tick bites and tick-borne diseases for raising public health awareness and prevention responses.
Effect of a Single Nutritional Intervention Previous to a Critical Period of Fat Gain in University Students with Overweight and Obesity: A Randomized Controlled Trial
Authors: Hernández-Jaña Sam , Huber-Pérez Tamara , Palma-Leal Ximena , Guerrero-Ibacache Paola , Campos-Nuñez Valentina , Zavala-Crichton Juan Pablo , Jorquera-Aguilera Carlos , Sadarangani Kabir P. , Rodríguez-Rodríguez Fernando , Cristi-Montero Carlos
Published: July 2020

Background: the present study aimed to investigate the effects of a single nutritional preventive session previous to a critical period linked to fat gain in university students with overweightness and obesity, emulating a nutritional session of a public health system. Methods: In this single-blind randomized controlled trial, 23 students met all the criteria to be included (20.91 ± 2.52-year-old; 52.2% women) who were divided into two groups: intervention group (IG) and control group (CG). Fat mass (FM) by dual-energy X-ray absorptiometry (DXA), physical activity by accelerometry, feeding evaluation through three questionnaires, and a set of healthy lifestyle recommendations were evaluated before and after the national holidays (NH). Results: Our findings showed that FM increased significantly in the CG, but not in the IG (CG = 428.1 g; IG = 321.9 g; Δ = 106.2 g; p = 0.654 [95% CI = −379.57, 591.92]). However, no differences were found during the NH between them (Hedges’ g effect size = 0.19; p = 0.654). In addition, no statistical differences were observed between groups in feeding evaluations, the set of recommendations performed, and physical activity. Conclusion: a single preventive session before a critical period, using a similar counselling approach as used in the public health system, might not be enough to promote changes in eating and physical activity patterns and preventing fat gain in overweight/obese university students. Long-term interventions are a must.
Comparison of a General and Conditional Measure of E-Cigarette Harm Perceptions
Authors: Wackowski Olivia A. , Jeong Michelle
Published: July 2020

Measures of tobacco product harm perceptions are important in research, given their association with tobacco use. Despite recommendations to use more specific harm and risk perception measures, limited research exists comparing different wordings. We present exploratory survey data comparing young adults’ (ages 18–29) responses to a general e-cigarette harm perception measure (“How harmful, if at all, do you think vaping/using an e-cigarette is to a user’s health?”) with a more specific conditional measure, which personalized the behavior/harm (“imagine you vaped,” “your health”) and presented a specific use condition (exclusive daily vaping) and timeframe (10 years). Data were collected in January 2019 (n = 1006). Measures were highly correlated (r = 0.76, Cronbach’s α = 0.86), and most (65%) provided consistent responses, although more participants rated e-cigarettes as very or extremely harmful using the conditional (51.6%) versus the general (43.9%) harm measure. However, significant differences in harm ratings were not observed among young adults who currently vaped. Correlations between each harm perception measure and measures of e-cigarette use intentions were similar. More specifically worded harm perception measures may result in somewhat higher e-cigarette harm ratings than general measures for some young adults. Additional research on best practices for measuring e-cigarette and other tobacco harm perceptions is warranted.
Relief Role of Lysine Chelated Zinc (Zn) on 6-Week-Old Maize Plants under Tannery Wastewater Irrigation Stress
Authors: Ahmad Rehan , Ishaque Wajid , Khan Mumtaz , Ashraf Umair , Riaz Muhammad Atif , Ghulam Said , Ahmad Awais , Rizwan Muhammad , Ali Shafaqat , Alkahtani Saad , Abdel-Daim Mohamed M.
Published: July 2020

Tannery wastewater mainly comes from leather industries. It has high organic load, high salinity, and many other pollutants, including chromium (Cr). Tannery wastewater is generally used for crop irrigation in some areas of Pakistan and worldwide, due to the low availability of good quality of irrigation water. As tannery wastewater has many nutrients in it, its lower concentration benefits the plant growth, but at a higher concentration, it damages the plants. Chromium in tannery wastewater accumulates in plants, and causes stress at physiological and biochemical levels. In recent times, the role of micronutrient-amino acid chelated compounds has been found to be helpful in reducing abiotic stress in plants. In our present study, we used lysine chelated zinc (Zn-lys) as foliar application on maize (Zea mays L.), growing in different concentrations of tannery wastewater. Zinc (Zn) is required by plants for growth, and lysine is an essential amino acid. Maize plants were grown in tannery wastewater in four concentrations (0, 25%, 50%, and 100%) and Zn-lys was applied as a foliar spray in three concentrations (0 mM, 12.5 mM, and 25 mM) during plant growth. Plants were cautiously harvested right after 6 weeks of treatment. Foliar spray of Zn-lys on maize increased the biomass and improved the plant growth. Photosynthetic pigments such as total chlorophyll, chlorophyll a, chlorophyll b and contents of carotenoids also increased with Zn-lys application. In contrast to control plants, the hydrogen peroxide (H2O2) contents were increased up to 12%, 50%, and 68% in leaves, as well as 16%, 51% and 89% in roots at 25%, 50%, and 100% tannery water application, respectively, without Zn-lys treatments. Zn-lys significantly reduced the damages caused by oxidative stress in maize plant by decreasing the overproduction of H2O2 and malondialdehyde (MDA) in maize that were produced, due to the application of high amount of tannery wastewater alone. The total free amino acids and soluble protein decreased by 10%, 31% and 64% and 18%, 61% and 122% at 25%, 50% and 100% tannery water treatment. Zn-lys application increased the amino acids production and antioxidant activities in maize plants. Zn contents increased, and Cr contents decreased, in different parts of plants with Zn-lys application. Overall, a high concentration of tannery wastewater adversely affected the plant growth, but the supplementation of Zn-lys assertively affected the plant growth and enhanced the nutritional quality, by enhancing Zn and decreasing Cr levels in plants simultaneously irrigated with tannery wastewater.
Effects of Match-Related Contextual Factors on Weekly Load Responses in Professional Brazilian Soccer Players
Authors: Gonçalves Luiz Guilherme Cruz , Kalva-Filho Carlos Augusto , Nakamura Fábio Yuzo , Rago Vincenzo , Afonso José , Bedo Bruno Luiz de Souza , Aquino Rodrigo
Published: July 2020

This study aimed to quantify the weekly training load distributions according to match location, opponent standard, and match outcome in professional soccer players. Rate-of-perceived-exertion-based training load (sRPE) and distance- and accelerometry-based measures were monitored daily during 52 training sessions and 11 matches performed by 23 players. Athletes who played ≥ 60 min during non-congested weeks were considered for data analysis. The training days close to away matches (e.g., one day before the match = MD-1) presented greater sRPE, distance-based volume measures, and mechanical work (player load) compared to the training days close to home matches (p = 0.001–0.002; effect size (ES) = medium−large). The most distant days of the home matches (e.g., five days before the match = MD-5) presented higher internal and external loads than before away matches (p = 0.002–0.003, ES = medium). Higher sRPE, distance-based volume measures, and mechanical work were found during the middle of the week (e.g., three days before the match, MD-3) before playing against bottom vs. medium-ranking teams (p = 0.001–0.01, ES = small−medium). These metrics were lower in MD-5 before matches against bottom vs. medium-ranking opponents (p = 0.001, ES = medium). Higher values of all external load measures were observed during the training session before winning matches (MD-1) compared to a draw or loss (p < 0.001–0.001, ES = medium−large). In conclusion, the training load distribution throughout the week varied considerably according to match-contextual factors.
Pollution Assessment Based on Element Concentration of Tree Leaves and Topsoil in Ayutthaya Province, Thailand
Authors: Molnár Vanda Éva , Simon Edina , Ninsawat Sarawut , Tóthmérész Béla , Szabó Szilárd
Published: July 2020

Atmospheric aerosol particles containing heavy metal contaminants deposit on the surface of plant leaves and the topsoil. Our aim was to reveal the pollution along an industrial–urban–rural gradient (IURG) in the central provinces of Thailand. Leaf samples from Ficus religiosa and Mimusops elengi were collected along with topsoil samples under the selected trees. Al, Ba, Ca, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, and Zn concentrations were determined by ICP-OES in soil and plant samples. Soils were not polluted according to the critical value; furthermore, the elemental composition did not differ among the sampling sites of the IURG. The rural site was also polluted due to heavy amounts of untreated wastewater of the adjacent Chao Phraya River. Bioaccumulation factors of Ba, Cu, and Mn was higher than 1, suggesting active accumulation of these elements in plant tissue. Our findings proved that the deposition of air pollutants and the resistance to air pollutants in the case of plant leaves were different and that humus materials of the soils had relevant role in bioaccumulation of Al, Ba, and Cu. At the same time, the geochemical background, the source of pollution, and the local plant species greatly influence the metal content of any given environmental compartment.
Rethinking Air Quality and Climate Change after COVID-19
Authors: Ching Joseph , Kajino Mizuo
Published: July 2020

The world is currently shadowed by the pandemic of COVID-19. Confirmed cases and the death toll has reached more than 12 million and more than 550,000 respectively as of 10 July 2020. In the unsettling pandemic of COVID-19, the whole Earth has been on an unprecedented lockdown. Social distancing among people, interrupted international and domestic air traffic and suspended industrial productions and economic activities have various far-reaching and undetermined implications on air quality and the climate system. Improvement in air quality has been reported in many cities during lockdown, while the death rate of COVID-19 has been found to be higher in more polluted cities. The relationship between the spread of the SARS-CoV-2 virus and air quality is under investigation. In addition, the battle against COVID-19 could bring short-lived and long-lasting and positive and negative impacts to the warming climate. The impacts on the climate system and the role of the climate in modulating the COVID-19 pandemic are the foci of scientific inquiry. The intertwined relationship among environment, climate change and public health is exemplified in the pandemic of COVID-19. Further investigation of the relationship is imperative in the Anthropocene, in particular, in enhancing disaster preparedness. This short article intends to give an up-to-date glimpse of the pandemic from air quality and climate perspectives and calls for a follow-up discussion.
Physical Activity, Screen Time, and Emotional Well-Being during the 2019 Novel Coronavirus Outbreak in China
Authors: Qin Fei , Song Yiqing , Nassis George P , Zhao Lina , Dong Yanan , Zhao Cuicui , Feng Yiwei , Zhao Jiexiu
Published: July 2020

We aimed to evaluate the effects of the COVID-19 lock down on lifestyle in China during the initial stage of the pandemic. A questionnaire was distributed to Chinese adults living in 31 provinces of China via the internet using a snowball sampling strategy. Information on 7-day physical activity recall, screen time, and emotional state were collected between January 24 and February 2, 2020. ANOVA, χ² test, and Spearman’s correlation coefficients were used for statistical analysis. 12,107 participants aged 18–80 years were included. During the initial phase of the COVID-19 outbreak, nearly 60% of Chinese adults had inadequate physical activity (95% CI 56.6%–58.3%), which was more than twice the global prevalence (27.5%, 25.0%–32.2%). Their mean screen time was more than 4 hours per day while staying at home (261.3 ± 189.8 min per day), and the longest screen time was found in young adults (305.6 ± 217.5 min per day). We found a positive and significant correlation between provincial proportions of confirmed COVID-19 cases and negative affect scores (r = 0.501, p = 0.004). Individuals with vigorous physical activity appeared to have a better emotional state and less screen time than those with light physical activity. During this nationwide lockdown, more than half of Chinese adults temporarily adopted a sedentary lifestyle with insufficient physical activity, more screen time, and poor emotional state, which may carry considerable health risks. Promotion of home-based self-exercise can potentially help improve health and wellness.