bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sex Differences in Physiological Stress Induced by a Long-Lasting Adventure Race: A Prospective Observational Analytical Study
Authors: Silva Romeu P.M. , Vilaça Alexandre , Guerra Fredy D. , Mundim Antonio V. , de Agostini Guilherme G. , de Abreu Luiz Carlos , Zhiguo Zhang , Sorpreso Isabel C. , Valenti Vitor E. , Penha-Silva Nilson 
Published: October 2019

Abstract
Background In order to provide additional information on the behaviour of biochemical parameters related to stress responses to a specific long-term competition, we aimed to compare the stressful effects of a long-lasting competition on physiological variables in men and women.
Methods This is a prospective observational analytical study. Twenty-five professional athletes, 15 men and 10 women, travelled 460 km for 4 days in an international edition of the Ecomotion/Pro AR World.
Results After the competition, we detected an increase in α-amylase and cortisol levels and a decrease in salivary immunoglobulin A (lgA) levels. The relative percentage changes in α-amylase, IgA and cortisol levels were significantly higher in women than in men, whereas women had lower relative percentage changes in glucose and lactate levels compared with men. There was a decrease in lymphocyte, eosinophil and monocyte counts, with relative percentage decreases in lymphocytes and monocytes being significantly higher in female athletes than in males. There were increases in the serum activities of total creatine kinase (CK), the creatine kinase myocardial isoform (CKMB), alanine aminotransferase (ALT), aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) at the end of the test, with significantly higher elevations of total CK, CKMB and LDH in men and ALT in women.
Conclusion Long-lasting competition induced stress, muscle damage, anaemia and changes in the immune system. Women had more intense responses of cortisol and leukocytes.
Probing the electric field across thylakoid membranes in cyanobacteria
Authors: Viola Stefania , Bailleul Benjamin , Yu Jianfeng , Nixon Peter , Sellés Julien , Joliot Pierre , Wollman Francis-André 
Published: October 2019

Significance
Cyanobacteria were the first organisms to develop oxygenic photosynthesis using water as a source of electrons. Today they remain widespread primary photosynthetic producers and hold a high biotechnological potential. In cyanobacteria, respiration and photosynthesis are interconnected in a complex network of electron fluxes. The study of cyanobacterial physiology is hampered by the lack of techniques, allowing a direct measurement of the transmembrane electric field that develops across their photosynthetic/respiratory membranes. Here, we characterized a probe of the transmembrane electric field, based on the ElectroChromic Shifts of carotenoids, thus opening unprecedented avenues to bioenergetics studies of these major photosynthetic organisms.
Recent progress in epitaxial growth of III–V quantum-dot lasers on silicon substrate
Authors: Pan Shujie , Cao Victoria , Liao Mengya , Lu Ying , Liu Zizhuo , Tang Mingchu , Chen Siming , Seeds Alwyn , Liu Huiyun 
Published: October 2019

Abstract
In the past few decades, numerous high-performance silicon (Si) photonic devices have been demonstrated. Si, as a photonic platform, has received renewed interest in recent years. Efficient Si-based III–V quantum-dot (QDs) lasers have long been a goal for semiconductor scientists because of the incomparable optical properties of III–V compounds. Although the material dissimilarity between III–V material and Si hindered the development of monolithic integrations for over 30 years, considerable breakthroughs happened in the 2000s. In this paper, we review recent progress in the epitaxial growth of various III–V QD lasers on both offcut Si substrate and on-axis Si (001) substrate. In addition, the fundamental challenges in monolithic growth will be explained together with the superior characteristics of QDs.
Hydride vapor phase epitaxy for gallium nitride substrate
Authors: Hu Jun , Wei Hongyuan , Yang Shaoyan , Li Chengming , Li Huijie , Liu Xianglin , Wang Lianshan , Wang Zhanguo 
Published: October 2019

Abstract
Due to the remarkable growth rate compared to another growth methods for gallium nitride (GaN) growth, hydride vapor phase epitaxy (HVPE) is now the only method for mass product GaN substrates. In this review, commercial HVPE systems and the GaN crystals grown by them are demonstrated. This article also illustrates some innovative attempts to develop homebuilt HVPE systems. Finally, the prospects for the further development of HVPE for GaN crystal growth in the future are also discussed.
Size effect on optical performance of blue light-emitting diodes
Authors: Ge Chang , Li Jing , Wang Guohong , Su Kang , Lu Xingdong 
Published: October 2019

Abstract
In this paper, size effects on optical performance of blue light-emitting diodes (LEDs) are investigated. The essential physical mechanism is studied by fabricating LEDs with various sizes of the active area and testing optical characteristics. It is found that micro-LEDs have better light extracting efficiency and thermal dissipation compared with broad-area LEDs, which is likely due to the small ratio of perimeter and active area. Furthermore, micro-LEDs are more beneficial for displays due to the stable wavelength under the low pulse width modulation (PWM) current density.
Preparation and characterization of AlN seeds for homogeneous growth
Authors: Zhang Li , Qi Haitao , Cheng Hongjuan , Jin Lei , Shi Yuezeng 
Published: October 2019

Abstract
Large size AlN bulk crystal has been grown on SiC heterogeneous seed by physical vapor transport (PVT). The properties of AlN wafer were characterized by high resolution X-ray diffraction (HRXRD), Raman spectroscopy, etched method and atomic force microscope (AFM). Growth mechanism of AlN crystal grown on heterogeneous SiC seeds was proposed. Crystallization quality of AlN samples were improved with the growth process, which is associated with the growth mechanism. AlN single wafer has excellent crystallization quality, which is indicated by HRXRD showing the (0002), (

) XRD FWHM of 76.3, 52.5 arcsec, respectively. The surface of the AlN wafer is measured by AFM with a roughness of 0.15 nm, which is a promising seed for AlN homogeneous growth.
Different carbon fibrous morphologies triggered by varying the average diameter of precursor electrospun fibers
Authors: Svinterikos E , Zuburtikudis I , Marzouqi M Al 
Published: October 2019

Abstract
Investigation of the factors affecting the carbonization process is very important for the manufacture of desired, on-demand carbon fibrous morphologies. In this work, the effect of the average fiber diameter on the carbonization of precursor polymer fibers into carbon fibers was examined. Three electrospun fibrous mats consisting of a lignin/recycled PET blend with mass ratio of 1/1 and having different average fiber diameter (80, 387 and 781 nm) were prepared. After they were carbonized at 600 °C, it was found that the thicker fibers (387 and 781 nm) yield well-formed carbon fibrous morphologies, with average diameter of the same range as the precursor ones. In contrast, the thinnest nanofibers with an average diameter of 80 nm fuse with each other and lose their fibrous morphology, due to the maximization of heat and mass transfer during the process. These results highlight the decisive role of the nanoscale dimension in processes controlled by heat and mass transfer phenomena, as in the case of carbon fiber manufacture.
Synthesis and Characterization of Pectin-Chitosan as Candidate Materials for Slow Release System
Authors: Hastuti Budi , Hadi Saptono 
Published: October 2019

Abstract
The polyelectrolyte complex (PEC) is a complex formed between opposite charge particles which have recently attracted attention for their potential for drug delivery applications. In this study, PEC from pectin (anionic species) and chitosan (cationic species) was studied. Pectin and chitosan solutions in 2% v/v acetic acid were mixed in the ratio pectin : chitosan of 1:1. The difference in characteristics of PEC pectin-chitosan (Pec-Chi) with its original polymer is indicated by functional group analysis using FTIR. Morphology characterization of films were investigated by XRD. The results showed that Pec-Chi adsorbent had better stability and resistance to the acidic environment. Characterization using FTIR showed that the adsorbent has functional groups of amines, carboxyl and hydrogen. Furthermore, XRD data show that the adsorbent was a not crystalline.
Development of a PEMFC dynamic model and the application to the analysis of fuel cell vehicle performance
Authors: Liu Wei , Peng Zhijun , Kim Bill , Gao Bo , Pei Yiqiang 
Published: October 2019

Abstract
In order to investigate basic output performances of PEMFC (Proton Exchange Membrane Fuel Cell) stack, a dynamic model of PEMFC stack has been developed by combining electrochemical sub-model and thermodynamic sub-model. With necessary validation, it demonstrates that modelling results and experimental data are in very good agreement in terms the U-I curve and power output. By applying the dynamic model to analyse performance outputs of PEMFC stack and applying the model for FC-Hybrid vehicle powertrain configuration, it demonstrates that improved PEMFC quality with increased maximum current density could increase the peak power output and also increase the working efficiency, although the increase of peak power is not linear relation with the increase of maximum current density. Higher working temperature of PEMFC would benefit the increases of both peak power output and efficiency. Compared to working temperature, ambient temperature’s increase could also make positive influence on power output and efficiency, though the influence is weak. Coupling the dynamic model with a powertrain model of FC-Electric hybrid vehicle, the analysis suggests that both PEMFC stack and battery stack should have similar size for general driving condition. Too big either PEMFC stack or battery stack would increase the total weight then contaminate the fuel/energy economy.
Kinetic study of the photocatalytic oxidation of ethylene over TiO2 thin films
Authors: Stroe Rodica-Elisabeta , Rosendahl Lasse A. 
Published: October 2019

Abstract
The photocatalytic oxidation process has been recognized as an environmental friendly, sustainable and low-cost technology for air treatment. A photocatalytic batch reactor has been employed to assess the kinetics of the oxidation of ethylene (C2H4) over immobilized titanium dioxide (TiO2) and the effect of initial pollutant concentration on the kinetics. The rate model based on the simplified mono-molecular Langmuir-Hinshelwood (LH) kinetic model was found to represent the degradation satisfactorily, however with numerical constrains. These were overcome by employing two different approaches. On one hand the Langmuir-Hinshelwood model was solved by means of the Lambert W-function and on the other hand it was reduced to a pseudo-first order rate law, both resulting in a good fit to the experimental data, thus proving that the photodegradation of C2H4 over TiO2 can be modelled by a first order rate law under low concentration conditions. Moreover, both models give a linear dependence between the reaction rate and the initial C2H4 concentration, making an estimation of reaction rate as a function of concentration possible, for a larger interval of C2H4 concentrations.
Fabrication, experimental investigation of jute fiber reinforced epoxy composites and hybrid composites
Authors: Aranno Tazbiul Mahmud , Mia Sobahan , Ullah Khan Md. Shafayet , Hasan M. A. Mehedi , Shams Supto Nyhan , Shaid Sujon Abu , Bin Rashid Adib , Ferdous Md. Shafiul 
Published: October 2019

Abstract
A special type of jute fiber woven mat was introduced by a hand loom. Epoxy jute fiber composites were fabricated using the woven fiber mat. A series of jute-hybrid epoxy composites based on the arrangement of the direction of jute fibers, and additional material were introduced to ensure the elevated mechanical properties of the composites. Improved mechanical properties were found in some cases of hybrid epoxy composites. It is discussed that the mechanical behavior is related to the fiber orientation, types of additional materials used in hybrid materials. The purpose of this study is to propose a simple technical method to prepare woven jute fiber mat by hand loom, and to produce epoxy jute fiber, hybrid composite materials to exhibit the elevated mechanical properties.
Study of photovoltaic solar materials development trend by deductive logic method using big data
Authors: Su Yi-Huei , Wu Jung-Hua 
Published: October 2019

Abstract
In recent years, the development of solar materials in the field of science and technology has experienced many major breakthroughs. This study collects relevant data to evaluate the development of solar energy technology based on deductive reasoning approach in the popular types, and then utilize big data to investigate the trend of smart materials development in solar energy research. This study aims to understand the impact of materials science on the development of photovoltaic solar energy and understand the trends in the research field from the number of published journals in past years.
The period of study in this paper is from 1970 to 2018. The research scope is limited to an analysis of solar journals from Web of Science®, which indicates that various solar materials have very obvious difference in growth trends.
From 1970 to 2010, although the United States was the country with the largest number of published solar journals, the percentage gradually decreased. Then from 2011 to 2018, China became the first among the top countries in solar energy materials publications.Among them, the field of “Dye-sensitized solar” grew the most, the highest research publications in the field of solar energy research is “Materials science”.
Deformation and energy distribution of metal tubes under internal explosive loading
Authors: Feng L N , Li D , Tian J D , Zhang Z F , Hu Z X 
Published: October 2019

Abstract
Deformation and energy distribution of two kinds of metal tubes under internal explosive loading have been studied by means of experiments and simulations in this paper. The velocity and displacement-time history of characteristic points on the flat metal tubes were measured by Photonic Doppler Velocimetry (PDV). Ls-dyna fluid-solid coupling algorithm was used to simulate the experiment. Simulation results agree well with the experimental results. On this basis, the expansive properties of the round tube in the same condition were obtained, the round tube directly expands to the maximum diameter, does not like the expansion and contraction fluctuant process of the flat tube. The simulation result shows that the flat tube will output more energy in the form of kinetic energy, while the round tube tends to store energy in the form of plastic strain energy.
Component layout optimization design based on genetic algorithm
Authors: Shen B , Pan Z W , Lin H , Li W Z 
Published: October 2019

Abstract
When working, electronic equipment is often subjected to a mechanical environment dominated by vibration. The printed circuit board (PCB) in the equipment is prone to deformation and transmits vibration to the components on the board. As the weakest link, the component corner position has a large acceleration, which is one of the important reasons for the failure of components and the entire electronic equipment. Based on the finite element modeling of PCB, the interaction between the finite element analysis software NASTRAN and the programming software MATLAB is realized, and the application of genetic algorithm in component layout optimization becomes possible. The optimization results show that the method adopted in this paper can effectively reduce the acceleration value at the component corner and optimize the mechanical environment when the electronic equipment works.
Formation of weld defects in cold metal transfer arc welded 7075-T6 plates and its effect on joint performance
Authors: İpekoğlu G , Çam G 
Published: October 2019

AbstractThis study aims at investigating the formation of weld defects (i.e., pores) and determining the effect of pores on mechanical performance of the AA7075-T6 plate joints produced using cold metal transfer (CMT) gas metal arc welding (GMAW) technique. For this purpose, AA7075-T6 Al-alloy plates with a thickness of 2 mm were joined using CMT welding technique. The microstructural and mechanical properties of the welded plates were investigated by detailed optical microscopy investigations, micro-hardness measurements and tensile tests. A correlation between the joint performance and the formation of porosity in the fusion zone (FZ) was also attempted to show the effect of the presence of large pores on the mechanical behavior of the joint.
Mechanical properties of reactive powder concrete: A review
Authors: Shi R J , Xiang Z , Liu S G , Wang D H , Ju Y Z 
Published: October 2019

Abstract
To promote engineering application of reactive powder concrete (RPC), based on the domestic and foreign research achievements, the preparation, mix proportion, mechanical properties of RPC were discussed. The results showed that different admixtures have different influence on mechanical properties of reactive powder concrete. High temperature curing can excitant material’s activity and improve the compressive strength of RPC. The axial tensile strength of RPC was usually in the range of 4∼12 MPa, and the splitting tensile strength and flexural strength of RPC were close and higher than that of axial tensile strength. The tensile properties of RPC can be greatly improved by increasing the fiber volume fraction.
Effects of process parameters on the microstructure and mechanical properties of medium-carbon steels for improving high-strain rate properties
Authors: Song Y B , Ham J H , Kim H K 
Published: October 2019

Abstract
The effects of accelerated continuous cooling and isothermal heat treatment process on the microstructure and mechanical properties of medium carbon bainitic steels was investigated to find an alternative process of the conventional austempering treatment process. Two kinds of medium carbon steel billets melted by Vacuum Induction Melting (VIM) were hot rolled to the thickness of 6∼12mm plates and accelerated-cooled to predetermined temperatures and then isothermal heat treatment was conducted immediately. For quantitative analysis of microstructures, the fraction of constituent phases such as retained austenite, martensite, and bainite was measured by XRD and dilatometry. A series of hardness, tensile, and impact tests was conducted to evaluate the mechanical properties of the plates. As the finish cooling temperature increased, the fraction of retained austenite increased and the fraction of martensite and bainite decreased due to the differences in carbon diffusion and transformation kinetics during isothermal heat treatment process. Microstructural observation results showed that the lath/block thickness and fraction of bainite and martensite were mainly dependent on austempering temperature and time. The thickness of bainite and the fraction of martensite were found to be the major factors influencing mechanical properties of the present medium-carbon nanostructured bainitic steels.
Mechanical characterization of mortars used in the restoration of historical buildings: an operative atlas for maintenance and conservation
Authors: Grazzini A , Zerbinatti M , Fasana S 
Published: October 2019

Abstract
The complexity of the architectural and structural restoration of historical buildings requires a careful choice in the use of repair mortars compatible with the original materials of the existing building. It is important to set up an atlas of reference, compared to many mixtures of mortars and conglomerates, useful to support the operational choices in the project of restoration, recovery, and maintenance of historical buildings. The aim is also to encourage the use of local materials with a “short supply chain”, compatible with buildings and applied by traditional techniques. The research makes use of experimental bending, compression and elastic modulus tests on different mixtures of mortars. This paper describes some of the first results obtained so far, because the research is still underway for many different mixtures to test and catalogue. The comparison between the data and the reference values that will be identified, will lead to set up a reference atlas of mechanical behaviour of repair mortars in order to direct the design and operational choices in function of requirements and performance (of the wall systems) of each specific cases in the field of the restoration of historical buildings.
Crack tip shape effect on stress-strain fields in plastically compressible materials
Authors: Alam M I , Khan D , Mittal Y , Kumar S 
Published: October 2019

Abstract
In the present study, the effects of crack tip shape on near tip deformation and fields are numerically investigated for a mode I crack under plane strain and small scale yielding conditions. The material is characterized by finite strain elastic-viscoplastic constitutive relation with bi-linear hardening and hardening-softening-hardening hardness functions. Both plastically incompressible and compressible solids have been considered for analyses. It has been observed that the combination of crack tip profile and plastic compressibility has significant effect on the near tip deformation and plastic fields.
Current trends in bioactive peptides from muscle foods and their potential application
Authors: Yongsawatdigul J , Hamzeh A 
Published: October 2019

Abstract
Muscle protein is a valuable source of energy and essential amino acids, which are needed for growth and maintenance of physiological functions. It also provides peptides known as bioactive peptides exerting some health benefits, including antihypertension, antioxidant activity, immunomodulatory activity, and improving brain function, among others. Bioactive peptides can be generated from digestion or enzymatic reaction. Cooking condition is found to critically affect digestibility of chicken breast and release of bioactive peptides. Extreme thermal treatment at 121°C/15 min reduces simulated gastrointestinal digestion (GI) of chicken breast. In addition, release of peptides inhibiting angiotensin converting enzyme (ACE) that regulates blood pressure via renin–angiotensin system decreases. This implies that extreme thermal process of muscle food lower nutritional values and available ACE inhibitor peptides. Enzymatic hydrolysis is also an effective means to produce bioactive peptides, providing appropriate protease(s) is applied under the optimal condition. Hydrolysates or bioactive peptides would likely be modified through GI digestion. Thus, changes of bioactivities upon GI digestion should be taken into consideration for optimization of protein hydrolysate production. Structural changes of bioactive peptides further take place during transepithelial transport. This would definitely affect bioactivities of peptides reaching the target organ in either positive or negative manner. To further develop functional food or nutraceutical products, efficacy of bioactive peptides should be tested in vivo to assure their health benefits.