bluuebunny/crossref_metadata_2025 huggingface dataset:
Cadmium Uptake in Native Cacao Trees in Agricultural Lands of Bagua, Peru
Authors: Oliva Manuel , Rubio Karol , Epquin Melissa , Marlo Gladys , Leiva Santos
Published: October 2020

Cadmium (Cd) contamination threatens cocoa farming in the province of Bagua in Amazonas, Peru. This study reports our assessment of Cd concentrations in cocoa farm soils, and in cocoa roots, leaves, testa, and cotyledon, thus evaluating the magnitude of the problem caused by Cd exposure. For our analysis, we sampled agricultural soil, cocoa roots, leaves and pods at 29 farms in the province of Bagua. Concentrations of Cd in each of the samples were measured and correlated with selected variables at each sampling site. Within our collection of samples, Cd levels showed great variability. In soil, Cd concentrations ranged between 1.02 and 3.54 mg kg−1. Concentrations of this metal within cocoa trees measured from roots, leaves, testa, and cotyledon, Cd ranged from 0.49 mg kg−1 to 2.53 mg kg−1. The cocoa trees exhibited variable degrees of allocation Cd from the soil to their tissues and thus considerable variation among themselves. We found that Cd amounts in roots were up to five times more concentrated than Cd levels in the soils and 2.85 times [Cd] the amounts found in cotyledon. Soil pH is a key variable enabling the uptake of this metal. Most importantly, our evaluation determined that measurements from the majority of farms exceeded the maximum permissible limits established by Peruvian and European legislation.
Circadian Rhythm in Adipose Tissue: Novel Antioxidant Target for Metabolic and Cardiovascular Diseases
Authors: Man Andy W. C. , Xia Ning , Li Huige
Published: October 2020

Obesity is a major risk factor for most metabolic and cardiovascular disorders. Adipose tissue is an important endocrine organ that modulates metabolic and cardiovascular health by secreting signaling molecules. Oxidative stress is a common mechanism associated with metabolic and cardiovascular complications including obesity, type 2 diabetes, and hypertension. Oxidative stress can cause adipose tissue dysfunction. Accumulating data from both humans and experimental animal models suggest that adipose tissue function and oxidative stress have an innate connection with the intrinsic biological clock. Circadian clock orchestrates biological processes in adjusting to daily environmental changes according to internal or external cues. Recent studies have identified the genes and molecular pathways exhibiting circadian expression patterns in adipose tissue. Disruption of the circadian rhythmicity has been suggested to augment oxidative stress and aberrate adipose tissue function and metabolism. Therefore, circadian machinery in the adipose tissue may be a novel therapeutic target for the prevention and treatment of metabolic and cardiovascular diseases. In this review, we summarize recent findings on circadian rhythm and oxidative stress in adipose tissue, dissect the key components that play a role in regulating the clock rhythm, oxidative stress and adipose tissue function, and discuss the potential use of antioxidant treatment on metabolic and cardiovascular diseases by targeting the adipose clock.
The Industrial Organism Corynebacterium glutamicum Requires Mycothiol as Antioxidant to Resist Against Oxidative Stress in Bioreactor Cultivations
Authors: Hartmann Fabian Stefan Franz , Clermont Lina , Tung Quach Ngoc , Antelmann Haike , Seibold Gerd Michael
Published: October 2020

In aerobic environments, bacteria are exposed to reactive oxygen species (ROS). To avoid an excess of ROS, microorganisms are equipped with powerful enzymatic and non-enzymatic antioxidants. Corynebacterium glutamicum, a widely used industrial platform organism, uses mycothiol (MSH) as major low molecular weight (LMW) thiol and non-enzymatic antioxidant. In aerobic bioreactor cultivations, C. glutamicum becomes exposed to oxygen concentrations surpassing the air saturation, which are supposed to constitute a challenge for the intracellular MSH redox balance. In this study, the role of MSH was investigated at different oxygen levels (pO2) in bioreactor cultivations in C. glutamicum. Despite the presence of other highly efficient antioxidant systems, such as catalase, the MSH deficient ΔmshC mutant was impaired in growth in bioreactor experiments performed at pO2 values of 30%. At a pO2 level of 20%, this growth defect was abolished, indicating a high susceptibility of the MSH-deficient mutant towards elevated oxygen concentrations. Bioreactor experiments with C. glutamicum expressing the Mrx1-roGFP2 redox biosensor revealed a strong oxidative shift in the MSH redox potential (EMSH) at pO2 values above 20%. This indicates that the LMW thiol MSH is an essential antioxidant to maintain the robustness and industrial performance of C. glutamicum during aerobic fermentation processes.
Frequency Response of Optically Pumped Magnetometer with Nonlinear Zeeman Effect
Authors: Zhang Rui , Wu Teng , Chen Jingbiao , Peng Xiang , Guo Hong
Published: October 2020

Optically pumped alkali atomic magnetometers based on measuring the Zeeman shifts of the atomic energy levels are widely used in many applications because of their low noise and cryogen-free operation. When alkali atomic magnetometers are operated in an unshielded geomagnetic environment, the nonlinear Zeeman effect may become non-negligible at high latitude and the Zeeman shifts are thus not linear to the strength of the magnetic field. The nonlinear Zeeman effect causes broadening and partial splitting of the magnetic resonant levels, and thus degrades the sensitivity of the alkali atomic magnetometers and causes heading error. In this work, we find that the nonlinear Zeeman effect also influences the frequency response of the alkali atomic magnetometer. We develop a model to quantitatively depict the frequency response of the alkali atomic magnetometer when the nonlinear Zeeman effect is non-negligible and verify the results experimentally in an amplitude-modulated Bell–Bloom cesium magnetometer. The proposed model provides general guidance on analyzing the frequency response of the alkali atomic magnetometer operating in the Earth’s magnetic field. Full and precise knowledge of the frequency response of the atomic magnetometer is important for the optimization of feedback control systems such as the closed-loop magnetometers and the active magnetic field stabilization with magnetometers. This work is thus important for the application of alkali atomic magnetometers in an unshielded geomagnetic environment.
Comparative Analysis of the Smear Layer Removal Capability between EndoVac and Endoactivator Endodontic Irrigation Systems at the Root Canal System and Isthmus: A Micro-Computed Tomography Analysis
Authors: Faus-Llácer Vicente , Luna-Roa Mauricio , Faus-Matoses Ignacio , Ruiz-Sánchez Celia , Zubizarreta-Macho Álvaro , Sauro Salvatore , Faus-Matoses Vicente
Published: October 2020

The aim of this comparative study is to analyze the efficacy of EndoVac and Endoactivator endodontic irrigation systems for removing the endodontic smear layer present in the coronal, middle, and apical root third of the root canal system (RCS) and the isthmus from mesial roots from the first lower molar teeth using micro-computed tomography (micro-CT) analysis. The study was performed on 40 mesial roots that were randomly assigned to the following groups: Group A, EndoVac endodontic irrigation system (EV) (n = 10); Group B, Endoactivator endodontic irrigation system (EA) (n = 10); Group C, Root canal systems performed with F2 ProTaper Gold endodontic rotary system but not irrigated (Positive control) (n = 10); Group D, Root canal systems not performed or irrigated (Negative control) (n = 10). The samples were exposed to micro-CT analysis and the mesial roots were segmented using an advanced image segmentation technique based on partial differential equations (ROI: 10 × 10 × 10 mm) and the root canal systems and isthmus were reconstructed at a resolution of 25 microns per voxel. The EA study group showed statistically significant different residual endodontic smear layer volume (0.48 ± 0.24 mm3) compared to the EV study group (0.18 ± 0.15 mm3) (p = 0.016). The EV endodontic irrigation system performed a higher smear layer removal at coronal and middle root thirds, compared to the EA endodontic irrigation system; however, the EA endodontic irrigation system performed a higher smear layer removal at the apical root third, compared to the EV endodontic irrigation system.
In Situ Determination of Solid Fraction from the Measured Hydrate Slurry Flow Rate and Pressure Drop across Orifice
Authors: Usman Muhammad , Rehman Zabdur , Seong Kwanjae , Song Myung Ho
Published: October 2020

Two-phase flow is encountered in various engineering areas, including the pharmaceutical, chemical, and food industries, desalination facilities, and thermal energy storage systems. Cost-effective and non-invasive monitoring of the solid volume fraction, which governs the thermos-physical properties of two-phase medium, is important for flow assurance. The flow loop having an inner diameter of 21.5 mm and length of about 12.2 m was equipped with square-edged orifice and slash plate pump. Tetrafluroethane (R134a) hydrate slurry of the specified solid volume fraction could be formed within the flow loop by removing an appropriate amount of water, and simultaneously injecting the pertinent amount of R134a while chilled at 275 K. The uncertainty in the thus-obtained solid volume fraction was smaller than 9%, with the largest contribution originating from the uncertain hydration number. The near power-law relationship between the orifice pressure loss coefficient and Metzner–Reed Reynolds number was recognized. However, the nonlinear nature of the Reynolds number with respect to the solid volume fraction inevitably makes the solution procedure iterative. The short span pressure differences across the orifice were regressed to yield empirical correlation, with which the solid volume fraction of R134a slurry could be determined from the measured pressure drop across the orifice and the flow rate. The uncertainty was less than 12% of the thus determined solid volume fraction.
Influence of Non-Reactive Epoxy Binder on the Permeability and Friction Coefficient of Twill-Woven Carbon Fabric in the Liquid Composite Molding Process
Authors: Yoo Hyeong Min , Lee Jung Wan , Kim Jung Soo , Um Moon Kwang
Published: October 2020

In the liquid composite molding process, a binder is used to fix the preform. In this study, the influence of a non-reactive epoxy binder was investigated. To allow the measurement of permeability, the preform specimen was produced under three preforming conditions: neat fabric preform, binder-treated fabric preform without heat treatment, and binder-treated fabric preform with heat treatment. The in-plane directional permeability, K1 (having maximum flow velocity), and K2 (having minimum flow velocity) of the binder-treated fabric preform decreased approximately 80% compared to the neat fabric preform. The permeability in the out-of-plane direction decreased approximately 80% in the binder-treated fabric preform without heat treatment and about 98% in the binder-treated fabric preform with heat treatment. This decrease occurred because the treated binder on the fiber hindered resin impregnation. The effect of the binder on the friction coefficient of carbon fabric was also investigated. The friction coefficient was high when the binder was on the friction surface and increased 40–200% at 110 °C, compared to 25 °C.
Evaluation of Acoustic Similarities in Two Italian Churches Honored to S. Dominic
Authors: Tronchin Lamberto , Bevilacqua Antonella
Published: October 2020

This paper compares two acoustical projects, applied to the S. Dominic church of Foligno and Imola, which are subject to a permanent and temporary conversion respectively, to places dedicated for listening to live music. Sets of measurements have been undertaken before the acoustical treatments in order to calibrate the digital model; in Foligno, the measurements have also been performed after the installation of the acoustical features, to check if the aims have been achieved. Between the proposed acoustical projects, only one has been realized in Foligno, with the artistic activity still running inside the auditorium. The challenge to adjust the acoustics of reverberant rooms like churches to host musical venues has been achieved with a good quality of sound perception. In particular, in S. Dominic church of Foligno, the goal has been hit after many digital simulations that calibrated the redirection of the sound towards the sitting areas.
Integration of an MES and AIV Using a LabVIEW Middleware Scheduler Suitable for Use in Industry 4.0 Applications
Authors: Rao Muzaffar , Lynch Liam , Coady James , Toal Daniel , Newe Thomas
Published: October 2020

Industry 4.0 uses the analysis of real-time data, artificial intelligence, automation, and the interconnection of components of the production lines to improve manufacturing efficiency and quality. Manufacturing Execution Systems (MESs) and Autonomous Intelligent Vehicles (AIVs) are key elements of Industry 4.0 implementations. An MES connects, monitors, and controls data flows on the factory floor, while automation is achieved by using AIVs. The Robot Operating System (ROS) built AIVs are targeted here. To facilitate MES and AIV interactions, there is a need to integrate the MES and the AIVs to help in building an automated and interconnected manufacturing environment. This integration needs middleware, which understands both MES and AIVs. To address this issue, a LabVIEW-based scheduler is proposed here as the middleware. LabVIEW communicates with the MES through webservices and has support for ROS. The main task of the scheduler is to control the AIV based on MES requests. The scheduler developed was tested in a real factory environment using the SAP MES and a Robotnik ‘RB-1′ robot. The scheduler interface provides real-time information about the current status of the MES, AIV, and the current stage of scheduler processing. The proposed scheduler provides an efficient automated product delivery system that transports the product from process cell to process cell using the AIV, based on the production sequences defined by the MES. In addition, using the proposed scheduler, integration of an MES is possible with any low-cost ROS-built AIV.
Dynamic Characteristics of a Gear System with Double-Teeth Spalling Fault and Its Fault Feature Analysis
Authors: Shi Luojie , Wen Juan , Pan Baisong , Xiang Yongyong , Zhang Qi , Lin Congkai
Published: October 2020

Tooth spalling is one of the most destructive surface failure models of the gear faults. Previous studies have mainly concentrated on the spalling damage of a single gear tooth, but the spalling distributed over double teeth, which usually occurs in practical engineering problems, is rarely reported. To remedy this deficiency, this paper constructs a new dynamical model of a gear system with double-teeth spalling fault and validates this model with various experimental tests. The dynamic characteristics of gear systems are obtained by considering the excitations induced by the number of spalling teeth, and the relative position of two faulty teeth. Moreover, to ensure the accuracy of dynamic model verification results and reduce the difficulty of fault feature analysis, a novel parameter-adaptive variational mode decomposition (VMD) method based on the ant lion optimization (ALO) is proposed to eliminate the background noise from the experimental signal. First, the ALO is used for the self-selection of the decomposition number K and the penalty factor â of the VMD. Then, the raw signal is decomposed into a set of Intrinsic Mode Functions (IMFs) by applying the ALO-VMD, and the IMFs whose effective weight kurtosis (EWK) is greater than zero are selected as the reconstructed signal. Combined with envelope spectrum analysis, the de-nosing ability of the proposed method is compared with that of the method known as particle swarm optimization-based variational mode decomposition (PSO-VMD), the fixed-parameter VMD, the empirical mode decomposition (EMD), and the local mean decomposition (LMD), respectively. The results indicate that the proposed dynamic model and background elimination method can provide a theoretical basis for spalling defect diagnosis of gear systems.
Study on Comprehensive Calibration and Image Sieving for Coal-Gangue Separation Parallel Robot
Authors: Shang Deyong , Wang Yuwei , Yang Zhiyuan , Wang Junjie , Liu Yue
Published: October 2020

Online sorting robots based on image recognition are key pieces of equipment for the intelligent washing of coal mines. In this paper, a Delta-type, coal gangue sorting, parallel robot is designed to automatically identify and sort scattered coal and gangue on conveyor belts by configuring the image recognition system. Robot calibration technology can reduce the influence of installation error on system accuracy and provides the basis for the robot to accurately track and grab gangue. Due to the fact that the angle deflection error between the conveyor belt coordinate system and the robot coordinate system is not considered in the traditional conveyor belt calibration method, an improved comprehensive calibration method is put forward in this paper. Firstly, the working principle and image recognition and positioning process of the Delta coal gangue sorting robot are introduced. The scale factor parameter Factorc of the conveyor encoder is adopted to characterize the relationship between the moving distance of the conveyor and the encoder. The conveyor belt calibration experiment is described in detail. The transformation matrix between the camera, the conveyor belt, and the robot are obtained after establishment of the three respective coordinate systems. The experimental results show that the maximum cumulative deviation of traditional calibration method is 13.841 mm and the comprehensive calibration method is 3.839 mm. The main innovation of the comprehensive calibration is such that the accurate position of each coordinate in the robot coordinate system can be determined. This comprehensive calibration method is simple and feasible, and can effectively improve system calibration accuracy and reduce robot installation error on the grasping accuracy. Moreover, a calculation method to eliminate duplicate images is put forward, with the frame rate of the vision system set at seven frames per second to avoid image repetition acquisition and missing images. The experimental results show that this calculation method effectively improves the processing efficiency of the recognition system, thereby meeting the demands of the grab precision of coal gangue separation engineering. The goal revolving around “safety with few people and safety with none” can therefore be achieved in coal gangue sorting using robots.
Effects of On-Site PV Generation and Residential Demand Response on Distribution System Reliability
Authors: Güner Sıtkı , Erenoğlu Ayşe Kübra , Şengör İbrahim , Erdinç Ozan , Catalão João P. S.
Published: October 2020

In the last few decades, there has been a strong trend towards integrating renewable-based distributed generation systems into the power grid, and advanced management strategies have been developed in order to provide a reliable, resilient, economic, and sustainable operation. Moreover, demand response (DR) programs, by taking the advantage of flexible loads’ energy reduction capabilities, have presented as a promising solution considering reliability issues. Therefore, the impacts of combined system architecture with on-site photovoltaic (PV) generation units and residential demand reduction strategies were taken into consideration on distribution system reliability indices in this study. The load model of this study was created by using load data of the distribution feeder provided by Bosphorus Electric Distribution Corporation (BEDAS). Additionally, the reliability parameters of the feeder components were determined based on these provided data. The calculated load point and feeder side indicators were analyzed comprehensively from technical and economic perspectives. In order to validate the effectiveness of the proposed structure, four case studies were carried out in both DigSILENT PowerFactory and MATLAB environments.
Optimized Size and Distribution of Silver Nanoparticles on the Surface of Titanium Implant Regarding Cell Viability
Authors: Hajdu Péter , Lampé István , Rácz Richárd , Biri Sándor , Csík Attila , Tóth Ferenc , Szalóki Melinda , Hegedűs Viktória , Dombrádi Zsuzsanna , Varga István , Csarnovics István , Kökényesi Sándor , Beke Dezső László , Hegedűs Csaba
Published: October 2020

Though the antibacterial effect is advantageous, silver and silver nanoparticles can negatively affect the viability of human tissues. This study aims to check the viability of cells on surfaces with different particle size and to find the biologically optimal configuration. We investigated the effect of modified thickness of vaporized silver and applied heat and time on the physical characteristics of silver nanoparticle covered titanium surfaces. Samples were examined by scanning electron microscopy, mass spectrometry, and drop shape analyzer. To investigate how different physical surface characteristics influence cell viability, Alamar Blue assay for dental pulp stem cells was carried out. We found that different surface characteristics can be achieved by modifying procedures when creating silver nanoparticle covered titanium. The size of the nanoparticles varied between 60 to 368 nm, and hydrophilicity varied between 63 and 105 degrees of contact angle. Investigations also demonstrated that different physical characteristics are related to a different level of viability. Surfaces covered with 60 nm particle sizes proved to be the most hydrophilic, and the viability of the cells was comparable to the viability measured on the untreated control surface. Physical and biological characteristics of silver nanoparticle covered titanium, including cell viability, have an acceptable level to be used for antibacterial effects to prevent periimplantitis around implants.
Comparison of Multivariate Analysis Methods as Applied to English Speech
Authors: Zhang Yixin , Nakajima Yoshitaka , Ueda Kazuo , Kishida Takuya , Remijn Gerard B.
Published: October 2020

A newly developed factor analysis, origin-shifted factor analysis, was compared with a normal factor analysis to analyze the spectral changes of English speech. Our first aim was to investigate whether these analyses would cause differences in the factor loadings and the extracted spectral-factor scores. The methods mainly differed in whether to use cepstral liftering and an origin shift. The results showed that three spectral factors were obtained in four main frequency bands, but neither the cepstral liftering nor the origin shift distorted the essential characteristics of the factors. This confirms that the origin-shifted factor analysis is more recommendable for future speech analyses, since it would reduce the generation of noise in resynthesized speech. Our second aim was to further identify acoustic correlates of English phonemes. Our data show for the first time that the distribution of obstruents in English speech constitutes an L-shape related to two spectral factors on the three-dimensional configuration. One factor had center loadings around 4100 Hz, while the other was bimodal with peaks around 300 Hz and 2300 Hz. This new finding validates the use of multivariate analyses to connect English phonology and speech acoustics.
The Potential of Using Tree-Ring Chronology from the Southern Coast of Korea to Reconstruct the Climate of Subtropical Western North Pacific: A Pilot Study
Authors: Kim Min-Seok , Zhang Peng , Woo Sung-Ho , Koh Youngdae , Linderholm Hans W. , Jeong Jee-Hoon
Published: October 2020

Tree-ring width (TRW) chronologies have successfully been used as climate proxies to infer climate variabilities over the past hundreds to thousands of years worldwide beyond observational records. However, these data are scarce over parts of subtropical East Asia, and especially over the Korean Peninsula. In this pilot study, Korean red pine (Pinus densiflora Siebold and Zucc.) TRW chronologies from Mt. Mudeung and Mt. Wolchul, South Korea, were developed, and their local- to large-scale climatic responses were investigated. Mt. Mudeung TRW had a positive association with local temperature in the preceding December and April. Mt. Wolchul TRW had a positive association with local temperature in the preceding December and most of the early summer to autumn months, and with local precipitation in February and October. On a large scale, both TRWs retained meaningful temperature and monsoon precipitation signals over East Asia and sea surface temperature signals over the Western North Pacific. The results suggest that the subtropical trees from South Korea can be used to infer past long-term climate variability at both local and large scales over East Asia and the Western North Pacific, such as the East Asian summer monsoon, the Kuroshio Current, the Western North Pacific Subtropical High, and El Niño–Southern Oscillation.
Controllable Hydrothermal Synthesis and Photocatalytic Performance of Bi2MoO6 Nano/Microstructures
Authors: Ji Tao , Ha Enna , Wu Mingzhou , Hu Xin , Wang Jie , Sun Yangang , Li Shijie , Hu Junqing
Published: October 2020

Bi2MoO6 with a tunable morphology was synthesized by a facile hydrothermal route using different surfactants, including nanosheet-assembled microspheres, smooth microspheres, nanoparticle aggregates and nanoparticles. The morphology, crystal structure and photocatalytic activity of as-obtained Bi2MoO6 were characterized by scanning electron microscopes (SEM), X-ray diffraction (XRD), photoelectron spectroscopy (XPS), Brunauer–Emmett–Teller (BET) and UV–Vis spectrophotometer. Bi2MoO6 flower-like microspheres using cetyl-trimethyl-ammonium bromide (BET) as the surfactant exhibited much better photocatalytic activity than Bi2MoO6 with the other morphologies, with a degradation efficiency of 98.4%. It can be summarized that the photocatalytic activity of Bi2MoO6 samples depends on their morphology and composition.
Rendering Visible-Light Photocatalytic Activity to Undoped ZnO via Intrinsic Defects Engineering
Authors: Chen Lan-li , Zhai Bao-gai , Huang Yuan Ming
Published: October 2020

It is significant to render visible-light photocatalytic activity to undoped ZnO nanostructures via intrinsic defect engineering. In this work, undoped ZnO nanocrystals were derived via co-precipitation synthesis. The resulting ZnO nanocrystals were characterized by means of X-ray diffraction, scanning electron microscopy, photoluminescence spectroscopy, and ultraviolet-visible absorption spectroscopy, respectively. The visible-light photocatalytic activity of the products were characterized by monitoring the decomposition of methyl orange in water under visible-light illumination of a 300 W halogen lamp. It is found that undoped ZnO nanocrystals exhibit visible-light photocatalytic activity with their first-order rate constant up to 4.6 × 10−3 min−1. Density functional calculations show that oxygen vacancies create deep energy levels at EV + 0.76 eV in the bandgap of ZnO. In conjunction with the density functional calculations, the photocatalytic degradation of methyl orange under visible-light irradiation provides direct evidence that oxygen vacancies in ZnO nanocrystals yield the visible-light photocatalytic activity. Our results demonstrate that visible-light photocatalytic activity can be endowed to undoped ZnO nanocrystals by manipulating the intrinsic defects in ZnO. Intrinsic defect-modulated ZnO photocatalysts thus represent a powerful configuration for further development toward visible-light responsive photocatalysis.
Impact of Climate Change on Vegetation Cover at South Port Sudan Area
Authors: Loh Pei Sun , Mohammed Alnoor Hussien Ibrahim , He Shuangyan
Published: October 2020

Arid regions worldwide, for example, Sudan, are affected by climate change and susceptible to environmental deterioration. In this study, temperature and rainfall data from 1985 to 2015 obtained from the Sudan Meteorological Authority were compared with satellite images of vegetation coverage in southern Port Sudan. The objective of this study was to determine the impact of climate change on the vegetation cover in this area. Results showed significant increases in the annual maximum, minimum and average temperatures with time, and precipitation showed a slight but not significant decrease from 1985 to 2015. The rates of increase for the annual maximum, minimum and average temperatures were 0.08 °C/year, 0.03 °C/year and 0.06 °C/year, respectively, and precipitation decreased at a rate of 0.12 mm/year. Higher shrub abundance and greater water area in 2013, 1995 and 1990 were probably due to high rainfall in the years preceding these years. Decreased shrub abundance in the year 2000 could be due to the significantly higher temperatures after 1998. There was no decreasing trend in shrub coverage from 1985 to 2015, but the overall increase in temperature and decrease in precipitation from 1985 to 2015 indicate a potential threat to vegetation in this area in the future.
Characteristics of Climate Change in the Lancang-Mekong Sub-Region
Authors: Li Han , Song Wei
Published: October 2020

The Lancang-Mekong River is an important international river in Southeastern Asia. In recent years, due to climate change, natural disasters, such as drought and flooding, have frequently occurred in the region, which has a negative effect on the sustainable development of the social economy. Due to the lack of meteorological monitoring data in the six countries across the region, the study of the characteristics of climate change in this area is still scarce. In this paper, we analyze the characteristics of climate change in the Lancang-Mekong sub-region (LMSR) during 2020–2100 based on the climatic data of CMIP5, using the linear trend rate method, cumulative anomaly method, the Mann–Kendall test, and Morlet wavelet analysis. The results showed that the annual mean temperature and annual precipitation in the LMSR increased significantly. The annual average temperature in this area increased at a rate of 0.219 °C/10a (p < 0.05) and 0.578 °C/10a (p < 0.05) in the RCP4.5 and RCP8.5 scenarios, respectively; the annual precipitation in the area was 29.474 mm/10a (p < 0.05) and 50.733 mm/10a (p < 0.05), respectively. The annual average temperature in the region changed abruptly from low to high temperatures in 2059 for the RCP4.5 scenario and 2063 for RCP8.5. The annual precipitation in the area changed from less to more in 2051 for the RCP4.5 scenario and 2057 for RCP8.5. The results of wavelet analysis showed that the annual mean temperature in the LMSR had no significant change period at the 95% confidence level under the scenario of RCP4.5 and RCP8.5. Under the scenario of RCP4.5 and RCP8.5, the annual precipitation had a significant 3.5-year and 2.5-year periodicity, respectively. Extreme climate events tended to increase against the background of global warming, especially in high emission scenarios.
Development of a Fluorine-Free Polymer-Assisted-Deposition Route for YBa2Cu3O7−x Superconducting Films
Authors: Nasui Mircea , Sonher Ramona Bianca , Petrisor Traian , Varodi Sorin , Pop Cornelia , Ciontea Lelia , Petrisor Traian
Published: October 2020

Polymer assisted deposition (PAD) was used as an environmentally friendly, non-fluorine, growth method for superconducting YBa2Cu3O7−x (YBCO) films. The kinetics of the thermal decomposition of the precursor powder was studied by thermogravimetry coupled with mass spectrometry (TG-QMS). YBCO films were spin coated on (100) SrTiO3 (STO) single crystalline substrates, followed by a single step thermal treatment under wet and dry O2 and O2/N2 mixture. The as-obtained films were epitaxially grown having a [001]YBCO||[001]STO out-of-plane epitaxial relationship and exhibited good superconducting properties with Tc (R = 0) > 88 K, transition widths, ΔT ≈ 2 K and critical current densities as high as 2.3 MA/cm2 at 77 K and self magnetic field.
Soft Ion Sputtering of PAni Studied by XPS, AFM, TOF-SIMS, and STS
Authors: Goodwin Christopher M. , Voras Zachary E. , Tong Xiao , Beebe Thomas P.
Published: October 2020

Herein is a study of the soft sputtering method, gas cluster ion sputtering (GCIS), and its effects on the atomic, morphologic, and band structure properties of polyaniline (PAni) as studied with X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry, atomic force microscopy, and scanning tunneling spectroscopy (STS). The GCIS source used was a 1000 argon atom cluster with 4 keV energy, which resulted in a sputter yield of 3.4 ± 0.2 × 10−3 nm3 per argon atom. Soft ion sputtering reduced the sample by explicitly removing the oxidized contaminants as determined by surface sensitive techniques: XPS and Time-of-flight secondary ion mass spectrometry (TOF-SIMS). By the use of STS we found that by removing the oxidized components, an overall shift of electronic states occurred, transitioning the states closer to the Fermi edge by 0.3 V.
Improving the Anti-Pilling Performance of Cellulose Fiber Blended Knitted Fabrics with 2,4,6-Trichloropyrimidine Treatment
Authors: Dong Xue , Xing Tieling , Chen Guoqiang
Published: October 2020

Pilling is a common and unresolved problem in knitted fabrics, especially for the cellulose fiber blended fabrics, which not only causes an unattractive appearance and an uncomfortable handle, but also reduces the added value of the products. In this study, four different kinds of knitted fabrics were treated with 2,4,6-trichloropyrimidine (TLP) alkaline emulsion by dipping and pad–dry–cure modification processes. The surface morphology and chemical structure of original and treated fabrics were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The anti-pilling performance, thermal properties, physical and mechanical properties and color features of treated fabrics were also evaluated. The results indicated that TLP was successfully covalently crosslinked onto the surface of the cellulose fibers. The dipping process resulted in a better anti-pilling property than that of the pad–dry–cure process, and both treatments could bring about an excellent anti-pilling property and outstanding laundering durability. A pilling grade of 4.5 was achieved for the treated polyester/viscose (T/V) fabric with the dipping process even after 20 washing cycles. In addition, the treated fabrics displayed an enhanced antistatic property and still maintained a soft handle. Besides, the bursting strength and air permeability of treated samples were found to have a slight deterioration, while no apparent differences were found in the color parameters and colorfastness of dyed fabrics. The above results demonstrate that 2,4,6-trichloropyrimidine has the potential application prospect in the functional finishing and home-caring of textiles.
The Effect of Equal-Channel Angular Pressing on Microstructure, Mechanical Properties, and Biodegradation Behavior of Magnesium Alloyed with Silver and Gadolinium
Authors: Straumal Boris , Martynenko Natalia , Temralieva Diana , Serebryany Vladimir , Tabachkova Natalia , Shchetinin Igor , Anisimova Natalia , Kiselevskiy Mikhail , Kolyanova Alexandra , Raab Georgy , Willumeit-Römer Regine , Dobatkin Sergey , Estrin Yuri
Published: October 2020

The effect of equal channel angular pressing (ECAP) on the microstructure, texture, mechanical properties, and corrosion resistance of the alloys Mg-6.0%Ag and Mg-10.0%Gd was studied. It was shown that ECAP leads to grain refinement of the alloys down to the average grain size of 2–3 μm and 1–2 μm, respectively. In addition, in both alloys the precipitation of fine particles of phases Mg54Ag17 and Mg5Gd with sizes of ~500–600 and ~400–500 nm and a volume fraction of ~9% and ~8.6%, respectively, was observed. In the case of the alloy Mg-6.0%Ag, despite a significant grain refinement, a drop in the strength characteristics and a nearly twofold increase in ductility (up to ~30%) was found. This behavior is associated with the formation of a sharp inclined basal texture. For alloy Mg-10.0%Gd, both ductility and strength were enhanced, which can be associated with the combined effect of significant grain refinement and an increased probability of prismatic and basal glide. ECAP was also shown to cause a substantial rise of the biodegradation rate of both alloys and an increase in pitting corrosion. The latter effect is attributed to an increase in the dislocation density induced by ECAP and the occurrence of micro-galvanic corrosion at the matrix/particle interfaces.
A Combined Experimental and Modelling Study on Solubility of Calcium Oxalate Monohydrate at Physiologically Relevant pH and Temperatures
Authors: Ibis Fatma , Dhand Priya , Suleymanli Sanan , van der Heijden Antoine E. D. M. , Kramer Herman J. M. , Eral Huseyin Burak
Published: October 2020

Accurate Calcium Oxalate Monohydrate (COM) solubility measurements are essential for elucidating the physiochemical mechanism behind the formation of kidney stones, nephrolithiasis. Yet the reported solubility values of COM in ultrapure water, arguably the simplest solvent relevant for nephrolithiasis, vary significantly depending on implemented method. To address this variation, we present an experimental study of the solubility of COM validated by a model based on the Debye–Hückel theory describing the solution chemistry and the complex formation. We also carefully monitor potential pseudopolymorphic/hydrate transitions during the solubility measurements with in-situ and ex-situ methods. Our results indicate that the solubility of COM in ultrapure water is a weak function of temperature. However, the measured solubility varies significantly in buffer solutions across physiologically relevant pH values at body temperature. The proposed model explains observed trends as a combined effect of ionic strength, protonation reactions, and soluble complex formation. Moreover, it predicts solubility of COM in buffer solutions remarkably well using our measurements in ultrapure water as input, demonstrating the consistency of presented approach. The presented study parleying experiments and modelling provides a solid stepping stone to extend the physiochemical understanding of nephrolithiasis to more realistic solutions laden with biological complexity.
Role of Strain Reversal in Microstructure and Texture of Pure Al during Non-Monotonic Simple Shear Straining
Authors: Bagherpour Ebad , Reihanian Mohsen , Ebrahimi Ramin , Qods Fathallah , Miyamoto Hiroyuki
Published: October 2020

The effect of reverse straining on the microstructure, texture, and hardness of the pure Al during the single cycle of the simple shear extrusion (SSE) process is investigated. Electron backscattering diffraction (EBSD), transmission electron microscopy (TEM), and scanning transmission electron microscopy (STEM) are used for microstructural evaluations. Due to the nature of the SSE process, the direction of the shear is reversed in the second half channel. As a result, the mean misorientation angle, dislocation density, and hardness decrease. The grain size increases to some extent in the exit of the channel compared with that in the middle. The structural evolution during the single pass of SSE is described in terms of the dislocation cancelling, “untangling” of the cell walls and disintegration of the “forward” cell structure due to the reverse straining in the second half channel. Some simple shear components replace the first texture component in the middle of the channel. At the exit of the channel, the primary texture components appear somewhat confirming the strain reversal effect in the second half channel.
Influence of Alumina Air-Abrasion on Flexural and Shear Bond Strengths of CAD/CAM Composite
Authors: Karntiang Pirat , Ikeda Hiroshi , Nagamatsu Yuki , Shimizu Hiroshi
Published: October 2020

The purpose of this study was to clarify the influence of alumina air-abrasion on flexural and bond strengths of CAD/CAM composites. The flexural strength (FS) of two brands of commercial CAD/CAM composites was investigated by the three-point bending test using two specimen designs: the single-bar according to the ISO standard and the bonded-double-bar fabricated by bonding two bars with a resin cement. The bond strength between the composites and the resin cement was measured by a conventional shear bond strength (SBS) test. The FS of single-bar specimens was significantly decreased by the air-abrasion. For the FS of the bonded-double-bar specimen, on the other hand, there was no significant difference between the specimens with/without air-abrasion. The SBS for the composites was significantly increased by air-abrasion. The results suggest that alumina air-abrasion improves the SBS of the composites while weakening its FS. Contrarily, the FS of the air-abraded composite did not decrease when the composites were bonded with the resin cement.
High-Entropy FeCoNiB0.5Si0.5 Alloy Synthesized by Mechanical Alloying and Spark Plasma Sintering
Authors: Zaara Kaouther , Chemingui Mahmoud , Le Gallet Sophie , Gaillard Yves , Escoda Lluisa , Saurina Joan , Suñol Joan Josep , Bernard Frédéric , Khitouni Mohamed , Optasanu Virgil
Published: October 2020

A FeCoNi(B0.5Si0.5) high-entropy alloy with the face-centered cubic (FCC) crystal structure was synthesized by mechanical alloying and spark plasma sintering (SPS). Phase evolution, microstructure, morphology and annealing behaviors were investigated. It was found that a single FCC solid solution appears after 50 h of milling. The grain size was 10 nm after 150 h of milling. Microstructure parameters were calculated by the Rietveld fitting of the X-ray Diffraction patterns. Magnetic characterizations of milled and annealed powders at 650 °C for 1 h were investigated. The heat treatment improves the magnetic properties of the milled powders by enhancing the saturation magnetization value from 94.31 to 127.30 emu/g and decreasing the coercivity from 49.07 to 29.57 Oe. The cohabitation of the FCC phase with the equilibrium crystalline phases observed after annealing is responsible of this magnetic softening. The as-milled powder was also consolidated by spark plasma sintering at 750 and 1000 °C. The obtained specimen consolidated at 750 °C improved the coercivity to 25.06 Oe and exhibited a compressive strength of 1062 Mpa and Vickers hardness of 518 ± 14 HV, with a load of 2 kN. The nanoindentation technique with the Berkovich indentor gave hardness and indentation elastic modulus of 6.3 ± 0.3 Gpa (~640 HV) and 111 ± 4 Gpa for samples consolidated by SPS at 750 °C.
Filling the Gap and Improving Conservation: How IUCN Red Lists and Historical Scientific Data Can Shed More Light on Threatened Sharks in the Italian Seas
Authors: Leonetti Francesco Luigi , Sperone Emilio , Travaglini Andrea , Mojetta Angelo R. , Signore Marco , Psomadakis Peter N. , Dinkel Thaya M. , Bottaro Massimiliano
Published: October 2020

Chondrichthyans are one of the most threatened marine taxa worldwide. This is also the case in the Mediterranean Sea, which is considered an extinction hotspot for rays and sharks. The central position of the Italian peninsula makes it an ideal location for studying the status and changes of this sea. There is a lack of biological, ecological and historical data when assessing shark populations, which is also highlighted in the Red List of Threatened Species compiled by the International Union for the Conservation of Nature (IUCN). Historical data can provide important information to better understand how chondrichthyan populations have changed over time. This study aims to provide a clearer understanding of the changes in distribution and abundance of eight shark species in the Italian seas that are currently classified as at risk of extinction by the IUCN. In this respect, a bibliographic review was conducted on items from the 19th century to the first half of the 20th century, focusing on the selected species. The results show that all sharks were considered common until the beginning of the 20th century but have declined since, with a clear negative trend, mainly in the past 70 years. The strong local decline has been attributed to overexploitation, bycatch, habitat loss, depletion of prey items and environmental pollution. Furthermore, historical data also allow us to avoid the issue of a ‘shifting baseline’, in which contemporary abundances are assumed to be “normal”. Using historical data to further our knowledge of the marine environment is becoming increasingly common, and is fundamental in understanding human impact and evaluating mitigation measures to manage and conserve marine species and environments.
Superficial Temporal Artery Perforator Flap: Indications, Surgical Outcomes, and Donor Site Morbidity
Authors: Rauso Raffaele , Nicoletti Giovanni Francesco , Sesenna Enrico , Lo Faro Carmelo , Chirico Fabrizio , Fragola Romolo , Lo Giudice Giorgio , Tartaro Gianpaolo
Published: October 2020

The aim of this retrospective case series was to discuss indications, surgical outcomes, and donor site morbidity in the use of superficial temporal artery perforator (STAP) flaps in intra-oral or extra-oral facial reconstruction. This study involved 9 patients treated with a STAP flap at the Maxillo-Facial Surgery Unit of the University of Campania “Luigi Vanvitelli”, Naples. A STAP flap was used alone or in combination with other local flaps, for the coverage of facial soft tissue defects, after the resection of craniofacial malignant tumors (n = 7) or as a salvage flap, in partial or total microvascular flap loss (n = 2). The STAP flap was proven to be a valuable surgical option despite it not being frequently used in facial soft tissue reconstruction nor was it chosen as the first surgical option in patients under 70 year’s old. Donor site morbidity is one of the major reasons why this flap is uncommon. Appropriate patient selection, surgical plan, and post-surgical touch-ups should be performed in order to reduce donor site scar morbidity.
Conceptualising Gifted Student (Dis) Engagement through the Lens of Learner (Re) Engagement
Authors: Ronksley-Pavia Michelle , Neumann Michelle M.
Published: October 2020

It is well-recognised that disengagement is a growing problem in schools across the globe. Furthermore, statistics show that nearly 60% of all gifted students are not actualising their potential, exposing the loss of potential for both the individual and society. While disengagement and underachievement are complex issues with no one root cause, it is well-established that when students are actively engaged in their learning, they learn more effectively. Talent actualisation is not guaranteed just because a student is gifted. As such there is heightened concern about student (dis)engagement, where there is a failure to adequately support (re)engagement so that gifted potential can develop into talent actualisation, which is evidenced through mastery. This conceptual article provides a new lens through which to explore (re)engagement opportunities for gifted students by conceptualising the interrelationship between three interconnected constructs: (1) four engagement dimensions (behavioural, affective, social, and cognitive); (2) Neihart and Betts’ six profiles of the gifted; and (3) appropriate pedagogical approaches aimed at (re)engagement. The authors’ focus on proposing new conceptualisations of these three interdependent constructs through a framework titled the (Re) Engagement Nexus Model. This model is intended as a starting point for future research in personalising (re)engagement opportunities for gifted learners and preventing underachievement and disengagement before it becomes entrenched.