bluuebunny/crossref_metadata_2025_split huggingface dataset:
Experimental study of flexural behavior and serviceability of hybrid concrete beams reinforced by steel and G/BFRP bars
Authors: Lu C H , Li H , Xu K , Xuan G Y , Abdullah W 
Published: March 2020

Abstract
In this paper, the flexural behavior and serviceability performance of concrete beams reinforced with hybrid glass/basalt fiber-reinforced polymer (G/BFRP) bars and steel bars were investigated. From the viewpoint of reducing the risk of steel corrosion, two kinds of hybrid reinforced beams were designed, eleven concrete beams including 3 steel-reinforced beams and 8 hybrid-reinforced beams were tested. The effect of the hybrid reinforcement ratio on the flexural performance was analyzed and the applicability of replacing steel bars with GFRP or BFRP bars in concrete beams was discussed. The results show that the ultimate bending moment of hybrid-reinforced concrete beam was about 91-97% of that of steel-reinforced concrete beam with the same reinforcement ratio. Since the reduction of the bearing capacity of hybrid-reinforced beam was small, it can be proved that it is feasible to replace the corner steel bar of concrete members with G/BFRP bars. For the serviceability performance of beams hybrid-reinforced with G/BFRP bars and steel bars, however, their deflection and maximum crack width were 20%-60% higher than that of steel-reinforced beams under the same load levels within the limit state of serviceability. It showed that the stiffness and crack resistance of hybrid beams weakened greatly. Finally, it was found that the FRP-to-steel ratio of bar areas had great influence on the flexural behavior and serviceability performance of concrete beams hybrid-reinforced with FRP and steel bars.
Graphene-polymer nanocomposites for thermal conductive applications
Authors: Zhang X , Zheng J , Du Y Q , Wang Z W , Wu Y D , Luo G 
Published: March 2020

Abstract
Graphene has been widely used in improving the physical properties of polymer composites. By adding different forms of graphene nanomaterials to the polymer matrix, the thermal conductivity of the polymer composite can be effectively improved. In this work, the research of graphene-polymer thermal composites is reviewed, and the main preparation methods and material design principles of graphene-polymer composites are analysed. The main preparation methods include improving the dispersion, surface modification, tailoring the size and loading, applying synergistic effect and building three-dimensional network of graphene.
The fracture resistance of bi-axially orientated PMMA
Authors: Zhao J Y , Blackman B , Patel Y , Yan Y 
Published: March 2020

Abstract
The mechanical performance of the transparent polymer PMMA (polymethyl methacrylate) can be significantly enhanced by the process of bi-axial stretching during manufacture. However, few studies have reported on the fracture properties of bi-axially oriented PMMA. In this work, the fracture toughness and resulting surface morphology of bi-axially orientated PMMA has been investigated by testing single edge notch bend fracture specimens under quasi-static test conditions. The orientation of the specimens with respect to the stretching direction was systematically varied such that the effect of in-plane orientation and out-of-plane orientation was determined. The out-of-plane fracture resistance was shown to be enhanced compared to the in-plane resistance and compared to amorphous PMMA. Both out-of-plane and in-plane crack orientations had little effect on fracture resistance. Complex crack growth behavior and surface morphologies were observed in the out-of-plane direction. The results have important implications for the study of damage tolerance of transparent canopies in the aircraft industry.
The effect of cement mortar composition on the pH value
Authors: Shafigh P , Yousuf S , Lee J C , Ibrahim Z 
Published: March 2020

Abstract
Cement-based materials (CBMs) initially start their life at a high pH of about 12.5-13.5, which is further reduced due to several factors. These include ageing, penetration of moisture, carbonation, chloride ingress, alkali leaching, corrosion, and other biodegradation processes. A less reported factor enhancing the above reduction is incorporation of supplementary cementitious materials (SCMs) as partial replacement of cement due to the consumption of Ca(OH)2 in their pozzolanic reaction. In this study, pH and effect of Ca(OH)2 contents of cement mortars having 50% of fly ash and ground granulated ballast furnace slag were studied up to the age of 150 days. The results obtained strongly indicate that pH is not only dependent on the Ca(OH)2 content in cement mortars as specified in the most previous studies.
Preparation of polyimide hollow fiber membrane
Authors: Li B L , Zhai Y , Liu Y , Jiu Y B 
Published: March 2020

Abstract
The polyimide hollow fiber membrane has the characteristics of high packing density, large specific surface area, simple membrane module structure, and good separation performance for CO2/CH4. Therefore, it has become a hotspot in the field of gas separation, while its preparation process needs further exploration. This study is aimed to prepare polyimide P84 hollow fiber membranes by the dry–wet phase transformation method and investigate the main influencing factors, such as spinning solution concentration, external coagulation bath selection, bore fluid selection, and air gap, in the preparation process. The results showed that the pore size of the dense layer of the hollow fiber membrane decreased with the spinning solution concentration. As the height of the air gap increased, the dense layer thickness on the outer surface also gradually rose. The external coagulation bath affected the internal finger holes of the hollow fiber membrane. As the external coagulation bath changed continuously from water, ethanol, and isopropanol to acetone, the finger pore structure decreased in turn. A mixed solution of water/isopropanol, water/ethanol, and water/acetone was used as the bore fluid. In the case of pure water application, the density of finger pores inside the film was remarkably reduced.
Inhibition effect of rosemary oil on mild steel corrosion in a water-based petrochemical drilling fluid
Authors: Loto R T , Busari A 
Published: March 2020

AbstractCorrosion inhibition of carbon steels applied in water-based petrochemical drilling fluid solution (DFS) with non-toxic chemical compounds is an important focus of research. Rosemary oil (ROS) was evaluated for its corrosion inhibition effect on mild steel (MS) in DFS by the potentiodynamic polarization technique and optical microscopy characterization. The corrosion rate data show that ROS effectively inhibited MS corrosion with an average inhibition efficiency above 90%. ROS displayed anodic type inhibition mechanism. The polarization curves displayed the passivation region, which signified the total surface coverage of MS surface. Morphological images of inhibited MS surface significantly differred from the control MS without ROS, whose surface was severely deteriorated by corrosion pits and grooves.
Influence of lap sequence on the Al/Steel FSKSW weld quality
Authors: Zhang Y H , Zhang Z K , Zheng J H , Zhao Z L 
Published: March 2020

Abstract
The joining of dissimilar metals of 5A02 aluminum alloy and DP600 galvanized steel was carried out by keyhole-free FSSW technique (FSKSW). The effect of lap sequences on the microstructure and mechanical properties of welded joints was also investigated. It was found that all keyholes of both stacking sequences were filled, and the steel on top of Al alloy could be stirred more thoroughly than that vice versa The microstructure of WNZ contained fine equiaxed grains, and TMAZ formed fully developed plastic flow, while HAZ had coarse grains. The temperature of two stacking sequences was similar during the welding process. Still, the axial force of the joints of steel on aluminum alloy was higher than that of aluminum alloy on steel. Similarly, the joint strength of the steel on aluminum alloy was also higher than that of aluminum alloy on steel. It was necessary to place the steel plates on the aluminum alloy sheets for metal plasticity and heat distribution.
The effect of graphite type on the growth of dense SiC ceramics prepared by the HTPVT method
Authors: Liu B B , Jing W J , Yang J F 
Published: March 2020

Abstract
Dense silicon carbide (SiC) ceramics were prepared by the high-temperature physical vapor transport (HTPVT) method at 2300°C using three types of graphite materials, namely common graphite (CP), isostatic graphite (IG), and graphite paper (GP), as crucible lids. The results indicated that the nucleation of SiC on CG was much easier than that on GP at the initial stage, but the polycrystalline growth on GP was faster. Moreover, the polycrystalline SiC ceramics growing on CG and IG lids were smaller than that grown on GP lid because many pores appeared at the interfaces between the grown polycrystalline SiC and CG and IG lids. As a result, the strength of the grown dense SiC ceramics on GP lid was about 8%–20%, higher than the strength of ceramics grown on the CG and IG lids.
Review of the test methods of the interface characterization of natural fiber-reinforced polymer composites
Authors: Zhu Z H , Zhang Y , Zhang N , Hao M Y , Wu H W 
Published: March 2020

Abstract
How to measure the interfacial strength of matrix and reinforcement is one of the key problems in the study of natural fiber reinforced polymer composites. The measurement technologies to study interface strength include destructive methods and non-destructive methods, which principles are introduced in this paper. Different tests can provide theoretical complementarity. Reasonable combination and improvement of interface strength tests can provide strong practical support for the study of interface property.
Effect of process temperature on mechanical properties of Ti6Al4V titanium alloy with warm laser shock peening
Authors: Pan X L , Zhou L C , He W F , Shi X S , Li R K , Feng X T , Wang X D 
Published: March 2020

AbstractWarm laser shock peening (WLSP) is a thermomechanical strengthening technique with tempering treatment during laser shock peening (LSP) to optimize the mechanical properties of a metallic material. In WLSP, processing temperature plays a key role in regulating the final product’s mechanical properties. In this work, Ti6Al4V titanium alloy is used to evaluate effect of temperature on mechanical properties during warm laser shock peening. The compressive residual stress (CRS) generated by WLSP at different temperature was measured by X-ray diffraction (XRD) and the surface hardness was investigated to reveal the surface strength features under different heat treatments as well. It was found that regardless of which temperature applied during the WLSP process, the treated specimens all displayed high-amplitude CRS on the surface or in depth, but the surface peak CRS decreases gradually as temperature increases. Specially, when the WLP temperature exceeded 250°C, the decreasing slope raised. The CRS affected width increased first, and then decreased with the increases of temperature. The maximum CRS affected width was about 6.25 mm, appearing at a temperature of 250 °C. For the affected depth of CRS, firstly, as the temperature increases from 20 to 250 °C, the thickness of affected layer rises with temperature. However, when the temperature exceeds 300°C, the affected depth of CRS sharply declines. In addition, the WLSP technology could improve the hardness of Ti6Al4V titanium alloy from 389 HV at room temperature to 418 HV at 350 °C
A simulation model and experimental study of X-ray transmission through a polycapillary focusing X-ray lens
Authors: Wang X Y , Luo H , Zhou M , Duan J Y , Li Y D , Lin X Y 
Published: March 2020

Abstract
A simulation model is established to simulate the X-ray transmission performance through a polycapillary focusing X-ray lens whose configuration curve was described by a piecewise function. The shape of the lens is segmented, and each segment uses different function curve. The ray tracing principle is used to simulate the transmission performance of X-rays through the polycapillary focusing X-ray lens. And the simulation results were compared with the experimental results.
Tribological behavior of TiAlN-coated TA19 alloy at elevated temperatures
Authors: Ding Z , Miao Q , Liang W P , Yang Z G , Yi J W , Lin H 
Published: March 2020

Abstract
TiAlN coating was deposited through the magnetron sputtering technology on the TA19 titanium alloy. The microstructure, composition, and binding force of the TiAlN coating were systematically evaluated. The friction and wear performance of coated specimens at elevated temperature were studied in detail. For elastic modulus E, the values of hardness H, H/E, and H3/E2 of the TiAlN coating were much higher than those of the matrix, which directly reduced the friction coefficient, wear volume, and wear rate of the TiAlN coating in high-temperature friction and wear. The friction mechanism of matrix and coating was mainly abrasive wear at room temperature. However, the coating and matrix suffered from tribo-oxidation at 300 and 500°C. In the process of friction and wear, the coating had no obvious characteristics of spalling and mechanical failure, showing good abrasive resistance at high temperature. This makes the TiAlN coating an effective high-temperature protective coating for titanium alloys.
Application of Mount Pinatubo lahar sand as fine aggregate in controlled low-strength materials
Authors: Alzona A R , Matriano K M , Galarosa A J , Malabanan A J , Mortel M S , Somera R J , Taguba M A , Santos M S Delos , Vahdanipour C M , Santos F D 
Published: March 2020

Abstract
Fine aggregates are key components of controlled low-strength materials (CLSM). These act as structural fillers that are integrally held together by cement paste controlling the mechanical properties and strength. In general, natural sand is the most common material used in the production of CLSM. Despite their low minimum compressive strength, CLSMs are used in highway construction as an alternative to compacted backfill. However, sand supply to road and infrastructure projects may be not sustainable. Meanwhile, in the low lying areas surrounding Mount Pinatubo in Phillippines, huge volumes of pyroclastic material and ashes were deposited due to the mountain’s cataclysmic eruption on 1991. To this date, the lahar washed down by the rains to the lowland municipalities and towns induce hazards during extreme rainfall events. Therefore, this study investigated the feasibility of lahar sand as fine aggregate in CLSM. Characterization of the controlled mixtures was performed via flowability, setting time, and compressive strength. Two controlled parameters (water-to-solid and cement-to-water ratios) were defined to show the statistical relationship among investigated properties with the different mixture proportions. Empirical results show acceptable characteristic values for the CLSM’s hardened state, making lahar sand be suitable as fine aggregates. The recommended water-to-solid and cement-to-water ratios for the CLSM mixture should be both 0.30.
Classification algorithms in the material science and engineering data mining techniques
Authors: Dardzinska A , Zdrodowska M 
Published: March 2020

Abstract
Data mining is an analytical process, which deals with the study of large data sets in search of patterns, correlations between data, and later their evaluation. The goal of data mining is usually prediction, among others sales volume, customer activities, extension ratios or the scale of customer loss. Data mining techniques allow finding previously unknown dependencies and schemas that can be used to support decision making or database description. Data mining techniques are developing very quickly and are more and more often used not only in typical fields such as customer relationship or management, but also in medicine, biomechanics, industry, materials sciences or mechanical engineering. The aim of this work is to evaluate the effectiveness of selected data mining techniques for predicting the concrete compressive strength, and to identify the features having the greatest impact on its compressive strength. The study analyzed the data of 1030 concrete samples using five known classification algorithms (C4.5, Random Forest, Naive Bayes Classifier, Supporting Vector Machine SVM) and neural networks (Multilayer Percepton), which allowed to build an exploration model given with an accuracy of over 99%. Potential features of concrete that may affect its compressive strength are also pointed out.
Determination of focal spot size of high-energy microfocal X-ray source based on HfO2-coated single-bounce ellipsoidal glass monocapillary X-ray condenser
Authors: Wang Y B , Shao S K , Zhang X Y , Li Y F , Sun X P , Liu Z G , Sun T X 
Published: March 2020

Abstract
A method based on the single-bounce ellipsoidal monocapillary X-ray condenser (SEGMXC) was improved for determining the focal spot size of the high-energy microfocal X-ray source. HfO2 was selected as the high-density material (∼9.68g/cm3) and coated on the inner surface of the SEGMXC by the atomic layer deposition method. The focal spot size of a microfocal spot X-ray source was obtained as 33.14 ± 0.02 μm and the relative deviation of the effective size given by the manufacturer was 5.3%.
Process parameters and mechanical properties of SAPH440 steel in pulse arc welding with different heat inputs
Authors: Liang S F , Chi L X , Gao X Z , Yan B L 
Published: March 2020

Abstract
Thermal cycling parameters of pulse arc welding for SAPH440 steel was experimentally determined for different heat inputs. The welding thermal cycle curves of the weld fusion and heat-affected zones were successfully constructed based on the thermocouple measurements through the back drilling hole. The hardness and tensile strength variations under different heat inputs were also analyzed. This provided a database for the determination and optimization of process parameters, improvement of microstructure and properties of weld fusion and heat affected zones, and overall quality of pulse arc welding of steels.
Shot peening effect on fatigue life of EN GJS 600-3 grade ductile iron wheel hubs
Authors: Arshad W , Bilal H A , Sun Z G , Shi W , Godfrey A 
Published: March 2020

Abstract
Durability of wheel hubs is limited by their fatigue failure. Wheel hubs are mostly manufactured by casting process using ductile iron, and their fatigue strength can be improved by shot peening, which induces compressive stresses at their surfaces. In this study, fatigue life of wheel hubs manufactured from grade EN GJS 600-3 iron was studied. Shot-peened and untreated wheel hubs were subjected to fatigue test with the number of loading cycles up to 1 million. The test results showed that all untreated wheel hubs failed the test, while all shot-peened ones passed the 1 million cycle’s milestone. This study proved that fatigue life of wheel hubs manufactured from grade EN GJS 600-3 iron was improved almost by 100 percent via shot peening.
Prenatal bisphenol A (BPA) exposure in a Brooklyn study of Afro-Caribbean women
Authors: Hoepner Lori A , Halden Rolf U , Pycke Benny F G , Abulafia Ovadia , Sherer David M , Geer Laura A 
Published: March 2020

Abstract
Prior studies suggest ubiquitous fetal exposure to the endocrine disrupting chemical bisphenol A (BPA). Insufficient information is available on the effects of BPA in underserved urban populations in the US. We describe prenatal BPA exposures in a predominately Afro-Caribbean immigrant population. Maternal third-trimester urinary concentrations of total BPA were measured in 181 mothers in Brooklyn, NY from 2007 to 2009. Mothers aged 18–45 y presenting at a prenatal clinic consented to study participation. Spot urine samples were collected once between the sixth and ninth month of pregnancy. The geometric mean concentration of total BPA was 0.12 μg l−1 (95% CI: 0.05–0.31). Total BPA concentrations were above the limit of detection in 9% of the mothers. Our results suggest that prenatal BPA exposure is low to non-detectable (< 0.02 μg l−1 in urine) among African American and Afro-Caribbean immigrant women residing in Brooklyn, NY. These results contradict evidence of prenatal exposure in prior studies of urban populations. Further studies should be conducted to determine whether there are associations between recent immigrant status and BPA exposures during pregnancy.
CNV-BAC: Copy number Variation Detection in Bacterial Circular Genome
Authors: Wu Linjie , Wang Han , Xia Yuchao , Xi Ruibin 
Published: March 2020

Abstract

Motivation
Whole-genome sequencing (WGS) is widely used for copy number variation (CNV) detection. However, for most bacteria, their circular genome structure and high replication rate make reads more enriched near the replication origin. CNV detection based on read depth could be seriously influenced by such replication bias.

Results
We show that the replication bias is widespread using ∼200 bacterial WGS data. We develop CNV-BAC (CNV-Bacteria) that can properly normalize the replication bias and other known biases in bacterial WGS data and can accurately detect CNVs. Simulation and real data analysis show that CNV-BAC achieves the best performance in CNV detection compared with available algorithms.

Availability and implementation
CNV-BAC is available at https://github.com/XiDsLab/CNV-BAC.

Supplementary information
Supplementary data are available at Bioinformatics online.
Gcluster: a simple-to-use tool for visualizing and comparing genome contexts for numerous genomes
Authors: Li Xiangyang , Chen Fang , Chen Yunpeng 
Published: March 2020

Abstract

Motivation
Comparing the organization of gene, gene clusters and their flanking genomic contexts is of critical importance to the determination of gene function and evolutionary basis of microbial traits. Currently, user-friendly and flexible tools enabling to visualize and compare genomic contexts for numerous genomes are still missing.

Results
We here present Gcluster, a stand-alone Perl tool that allows researchers to customize and create high-quality linear maps of the genomic region around the genes of interest across large numbers of completed and draft genomes. Importantly, Gcluster integrates homologous gene analysis, in the form of a built-in orthoMCL, and mapping genomes onto a given phylogeny to provide superior comparison of gene contexts.

Availability and implementation
Gcluster is written in Perl and released under GPLv3. The source code is freely available at https://github.com/Xiangyang1984/Gcluster and http://www.microbialgenomic.com/Gcluster_tool.html. Gcluster can also be installed through conda: ‘conda install -c bioconda gcluster’.

Supplementary information
Supplementary data are available at Bioinformatics online.