bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of voltage and spray–off distance of electric-arc spray technique on surface properties of nickel–chrome (Ni–Cr) coating developed on 304L stainless steel
Authors: Inam A , Raza M A , Hafeez M A , Shah S B , Ishtiaq M , Hassan M H , Irfan M , Nasik A , Siddique I , Butt O M , Maqbool A , Haider W 
Published: December 2019

Abstract
Nickel–chrome coatings are widely used to improve surface properties and service life of engineering components made from different ferrous and non–ferrous alloys. Herein, an attempt has been made to investigate the impact of various voltages ranging from 26–30 V and spray–off distances ranging from 100–300 mm of electric-arc spray technique on the surface properties of Ni–Cr coating developed on 304L stainless steel. Thickness, porosity, surface morphology, surface roughness, and hardness of Ni–Cr coatings were determined to study the impact of deposition parameters. Coating deposition at 26 V exhibited the lowest porosity and the highest percentage of Cr nodules among all samples. The comparison study showed that coating deposit developed at 26 V and 100 mm spray–off distance has a maximum thickness, followed by coating developed at 30 V and 100 mm spray–off distance. This indicated that coating deposit developed at 100 mm spray–off distance results in thicker coatings. Maximum hardness was achieved at 30 V and 300 mm spray–off distance. The shorter spray–off distance revealed that coatings tend to be thicker and harder resulting in longer coating life.
Exploring configurations and properties of boron carbide by first principle
Authors: Liu Meiling , Liu Chao , Kumar Uppalapati Pramod , Chen Mingwei 
Published: December 2019

Abstract
Based on the first principle, the formation energy, phonon vibration, physical property of three common B4C models were extensively study. Through the calculation of thermodynamic formation energy, it is confirmed po model has the most stable energy configuration. Combined the simulated x-ray and experimental data, it is found that the experimental boron carbide is actually composed of a variety of configurations, the majority of which is po model. Via the analysis of phonon vibration, the highest phonon frequencies of the different configurations were identified as the result of stretching vibrations from the triatomic chain. The research of electrical properties of three B4C models clarify B4C is a semiconductor but will transform to conductor at specific high pressure. The calculation of the mechanical property states that B4C is hard material while the hardness will gradually decrease with pressure increases. Both the relationship of their electrical properties and mechanical properties with pressure illustrate that the po model has the fastest structural change and ch model has the slowest change.
A comparative investigation of hardness and compression strength of Nickel coated B4C reinforced 601AC/201AC selective layered functionally graded materials
Authors: Vijay S , CH Srinivasa Rao 
Published: December 2019

Abstract
High hardness and compression strength are the essential properties in many engineering applications. Requirement of light weight materials with high mechanical properties as a function of direction leads to the development of Aluminium based Functionally Graded Materials (FGM). Two different matrix metal blends 601AC and 201 AC are used for the comparison. Mechanical Alloying technique (MA) is used to blend the metal powders. The FGM specimens with 2 layers, 3 layers and 5 layers are fabricated using Powder Metallurgy (P/M) technique. B4C with Nickel coating and without Nickel coating is used as particulate. Two different average particle size of B4C (20 μm and 50 μm) was selected. The configurations used for the FGMs are 0%/5% for 2 layered specimen, 0%/5%/10% for 3 layered specimen and 0%/5%/10%/15%/20% for five layered specimen. Specimens are prepared according to ASTM B925-3 standard for micro-hardness test and compressive strength test. Graphs are plotted in terms of number of layers, particle size, sintering temperature, and coating condition. From the experiments it is observed that, number of layers influences the hardness and compressive strength. The average specimen hardness is enhanced from 55 HV for two layered FGM to 73 HV for three layered FGM. The compressive strength is increase from 613 MPa for three layered specimen without Nickel coated B4C to 732 Mpa for three layered specimen with Nickel coating. Best possible combination of all parameters is observed from the experiment is particle size of 20 μm, sintering temperature of 570 °C, and B4C particulate with Nickel coating. Compared to the hardness values for two different matrix materials 601AC/201AC, closure values are observed for the best possible combination of other variables. Where-as for the compressive strength 201AC matrix shows superior values compared to 601AC for the best possible combination of all the other variables.
Effect of Mn addition on magnetoelectric coupling behavior of BiFeO3-Pb/BaTiO3 multiferroics
Authors: Kumar Naveen , Bastola Narayan , Singh Arun Kumar , Kumar Sanjeev 
Published: December 2019

Abstract
Hybrid multiferroic materials exhibiting morphotropic phase boundary (MPB) with enhanced ferroelectric and ferromagnetic properties has shown great potential for future technologies. In this paper, we report structural, ferroelectric, piezoelectric, magnetic and magnetoelectric characteristics of 0.7BiFeO3–0.3Pb0.5Ba0.5TiO3 (BFPTBT-Pure) and 0.7BiFeO3–0.3Pb0.5Ba0.5TiO3 + Mn0.5% (BFPTBT-Mn5%) ceramic compositions synthesized via conventional solid state reaction route. The crystallinity of the compositions exhibits polymorphs of rhombohedral (R3c) and tetragonal (P4mm) symmetries forming morphotropic phase boundary (MPB). Highly dense SEM micrographs were observed with an average grain size 0.57 μm and 0.62μm for BFPTBT-Pure and BFPTBT-Mn5%, respectively. Mn doped ceramic sample. Improved ferroelectric behavior has been observed with Mn doping in the composition as the value of remnant polarization increases from 2.46 μC cm−2 to 7.63 μC cm−2 recorded at an applied frequency of 50 Hz. The piezoelectric coefficients for BFPTBT-Pure and BFPTBT-Mn5% were found to be 36pC/N and 57pC/N respectively. M-H hysteresis loops depicted that remnant magnetization increases with Mn addition in the sample. The Curie transition temperature (T

c
) was observed to be 447 °C and 467 °C for BFPTBT-Pure and BFPTBT-Mn5% ceramics, respectively. The magnetoelectric coupling was confirmed through the observation of magnetic field induced relative change in dielectric constant (Magnetocapacitance: MC). MC was found to be 9.49% and 11.81% for BFPTBT-Pure and BFPTBT-Mn5%, respectively.
Low velocity impact, compression after impact and morphological studies on flax fiber reinforced with basalt powder filled composites
Authors: Prasath K Arun , Arumugaprabu V , Amuthakkannan P , Manikandan V , Deepak Joel Johnson R 
Published: December 2019

Abstract
The objective of this research is to examine the low velocity impact (LVI) and effect of compression after impact (CAI) properties on flax fiber and basalt powder reinforced polyester composites. For this study the 10 layers of flax fiber, basalt powder by varying from 5% to 30% the composites were prepared. In the LVI analysis composite (10 layers of basalt/10% of basalt powder) shows better results about 1755 N of force and for CAI also same composite B experienced with less deformation and more residual energy to absorbing the force of about 2250 N. The addition of filler material up to certain limit will support the reinforcing fiber to achieve some enhanced property. The morphological changes and their properties were assessed using Fourier Transform Infrared Spectroscopy (FTIR) and x-ray diffraction Analysis (XRD) studies for particulate basalt powder. The presence of Pyroxene group of rocks in basalt powder responsible for stability in high temperatures seen using XRD analysis. The band width around 3390–3425 cm−1 shows the presence of hydroxyl group (OH) in the basalt powder. This proved that the materials are Polar Hydrophilic in nature examined with FTIR spectroscopy.
Effect of annealing temperature on the morphology, structure, and optical properties of nanostructured SnO(x) films
Authors: Timofeev Vyacheslav A , Mashanov Vladimir I , Nikiforov Alexandr I , Azarov Ivan A , Loshkarev Ivan D , Korolkov Ilya V , Gavrilova Tatyana A , Yesin M Yu , Chetyrin Igor A 
Published: December 2019

Abstract
Nanostructured SnO(x) films were obtained by molecular beam epitaxy (MBE). The morphology, structure, and optical properties of obtained films annealed in the temperature range of 200 °C–1000 °C were studied. The reflection high-energy electron diffraction during the film deposition by the MBE method and the x-ray phase analysis showed that the initial films are in the polycrystalline phase. A single orthorhombic SnO2 phase was obtained for the first time after annealing the SnO(x) film in the air at a temperature of about 500 °C. The sharp change in the optical constants near the temperature of 500 °C was established using ellipsometry. The pronounced absorption edge appears in the short-wave region at temperatures above 500 °C and it disappears at lower temperatures. The film thickness changed non-monotonically during the annealing in the air. At first, it grows from 45 nm to 65 nm (active oxidation to 500 °C), and then (above 600 °C) it begins to decrease. The annealing at temperatures of 500 °C–1000 °C leads to the film compaction, since the film thickness decreases to 50 nm, but the refractive index increases by 10%–15%. Optical constants track the progress of film phase and morphological changes.
Extensive paraphyly in the typical owl family (Strigidae)
Authors: Salter Jessie F , Oliveros Carl H , Hosner Peter A , Manthey Joseph D , Robbins Mark B , Moyle Robert G , Brumfield Robb T , Faircloth Brant C 
Published: December 2019

AbstractThe typical owl family (Strigidae) comprises 194 species in 28 genera, 14 of which are monotypic. Relationships within and among genera in the typical owls have been challenging to discern because mitochondrial data have produced equivocal results and because many monotypic genera have been omitted from previous molecular analyses. Here, we collected and analyzed DNA sequences of ultraconserved elements (UCEs) from 43 species of typical owls to produce concatenated and multispecies coalescent-based phylogenetic hypotheses for all but one genus in the typical owl family. Our results reveal extensive paraphyly of taxonomic groups across phylogenies inferred using different analytical approaches and suggest the genera Athene, Otus, Asio, Megascops, Bubo, and Strix are paraphyletic, whereas Ninox and Glaucidium are polyphyletic. Secondary analyses of protein-coding mitochondrial genes harvested from off-target sequencing reads and mitochondrial genomes downloaded from GenBank generally support the extent of paraphyly we observe, although some disagreements exist at higher taxonomic levels between our nuclear and mitochondrial phylogenetic hypotheses. Overall, our results demonstrate the importance of taxon sampling for understanding and describing evolutionary relationships in this group, as well as the need for additional sampling, study, and taxonomic revision of typical owl species. Additionally, our findings highlight how both divergence and convergence in morphological characters have obscured our understanding of the evolutionary history of typical owls, particularly those with insular distributions.
Potential Impacts of Translocation of Neonicotinoid Insecticides to Cotton (Gossypium hirsutum (Malvales: Malvaceae)) Extrafloral Nectar on Parasitoids
Authors: Jones Asher G , Hoover Kelli , Pearsons Kirsten , Tooker John F , Felton Gary W 
Published: December 2019

Abstract
Neonicotinoid seed treatments are frequently used in cotton (Gossypium hirsutum L. [Malvales: Malvaceae]) production to provide protection against early-season herbivory. However, there is little known about how these applications affect extrafloral nectar (EFN), an important food resource for arthropod natural enemies. Using enzyme-linked immunosorbent assays, we found that neonicotinoids were translocated to the EFN of clothianidin- and imidacloprid-treated, greenhouse-grown cotton plants at concentrations of 77.3 ± 17.3 and 122.6 ± 11.5 ppb, respectively. We did not find differences in the quantity of EFN produced by neonicotinoid-treated cotton plants compared to untreated controls, either constitutively or after mechanical damage. Metabolomic analysis of sugars and amino acids from treated and untreated plants did not detect differences in overall composition of EFN. In bioassays, female Cotesia marginiventris (Cresson) (Hymenoptera: Braconidae) parasitoid wasps that fed on EFN from untreated, clothianidin-treated, or imidacloprid-treated plants demonstrated no difference in mortality or parasitization success. We also conducted acute toxicity assays for C. marginiventris fed on honey spiked with clothianidin and imidacloprid and established LC50 values for male and female wasps. Although LC50 values were substantially higher than neonicotinoid concentrations detected in EFN, caution should be used when translating these results to the field where other stressors could alter the effects of neonicotinoids. Moreover, there are a wide range of possible sublethal impacts of neonicotinoids, none of which were explored here. Our results suggest that EFN is a potential route of exposure of neonicotinoids to beneficial insects and that further field-based studies are warranted.
Early postoperative statin administration does not affect the rate of atrial fibrillation after cardiac surgery
Authors: Khan Jahangir A , Laurikka Jari O , Järvinen Otto H , Khan Niina K , Järvelä Kati M 
Published: December 2019

Abstract

OBJECTIVES
Postoperative atrial fibrillation is the most frequent complication after cardiac surgery, and the use of statins in preventing them is being extensively studied. The aim of this study was to investigate whether a pause in the administration of statins affects the occurrence of atrial fibrillation after cardiac surgery in a prospective randomized and controlled setting.

METHODS
A total of 301 patients without chronic atrial fibrillation with prior statin medication scheduled for elective or urgent cardiac surgery involving the coronary arteries and/or heart valves were prospectively recruited and randomized for statin re-initiation on either the first (immediate statin group) or the fifth (late statin group) postoperative day, using the original medication and dosage. The immediate statin group comprised 146 patients and the late statin group 155 patients. Except for a somewhat higher rate of males (85% vs 73%, P = 0.016) in the immediate statin group, the baseline characteristics and the distribution of procedures performed within the groups were comparable. The occurrence of postoperative atrial fibrillation and the clinical course of the patients were compared between the groups.

RESULTS
The incidence of atrial fibrillation was 46% and the median delay after surgery before the onset of atrial fibrillation was 3 days in both groups (P = NS). No differences were observed in the frequency of the arrhythmia in any subgroup analyses or in other major complications or clinical parameters. No adverse effects related to early statin administration were detected.

CONCLUSIONS
Early re-initiation of statins does not appear to affect the occurrence of postoperative atrial fibrillation.

Clinical trial registration
European Union Drug Regulating Authorities Clinical Trials Database (EudraCT)—2016-001655-44.
High haemoglobin A1c level is a possible risk factor for ventricular fibrillation in sudden cardiac arrest among non-diabetic individuals in the general population
Authors: van Dongen Laura H , Blom Marieke T , Bardai Abdenasser , Homma Paulien C M , Beulens Joline W J , van der Heijden Amber A , Elders Petra , Tan Hanno L 
Published: December 2019

Abstract

Aims
This study aimed to establish whether higher levels of glycated haemoglobin (HbA1c) are associated with increased sudden cardiac arrest (SCA) risk in non-diabetic individuals.

Methods and results
Case–control study in non-diabetic individuals (HbA1c &lt; 6.5%) in the Netherlands. Cases were SCA patients with electrocardiogram (ECG)-documented ventricular fibrillation (VF, the predominant cause of SCA) and HbA1c measurements immediately after VF, prospectively included in September 2009–December 2012. Controls (up to 10 per case) were age/sex-matched non-SCA individuals, included in July 2006–November 2007. We studied 306 cases (56.4 ± 6.8 years, 79.1% male) and 1722 controls (54.0 ± 6.8 years, 64.8% male). HbA1c levels were higher in cases than in controls (5.8 ± 0.3% vs. 5.4 ± 0.3%, P &lt; 0.001). The proportion of increased HbA1c (≥5.7%) was 63.1% in cases and 19.3% in controls (P &lt; 0.001). Multivariate regression models indicated that increased HbA1c was associated with a &gt; six-fold increased VF risk [adjusted odds ratio (ORadj) 6.74 (5.00–9.09)] and that 0.1% increase in HbA1c level was associated with 1.4-fold increase in VF risk, independent of concomitant cardiovascular risk factors. Increased VF risk at higher HbA1c is associated with acute myocardial infarction (MI) as cause of VF [OR 1.14 (1.04–1.24)], but the association between HbA1c and VF was similar in non-MI patients [OR 1.32 (1.21–1.44)] and MI patients [OR 1.47 (1.37–1.58)].

Conclusion
Among non-diabetic individuals, risk of VF increased with rising HbA1c levels, independent of concomitant cardiovascular disease. Future studies should establish whether HbA1c level may be used as biomarker to recognize individuals at risk for VF.
Longitudinal Association Between Perceived Fatigability and Cognitive Function in Older Adults: Results from the Baltimore Longitudinal Study of Aging
Authors: Salerno Elizabeth A , Wanigatunga Amal A , An Yang , Urbanek Jacek K , Simonsick Eleanor M , Ferrucci Luigi , Resnick Susan M , Schrack Jennifer A 
Published: December 2019

Abstract

Background
Cognitive decline is consistently associated with diminished life satisfaction and inability to live independently. Identifying early, novel markers of cognitive decline is imperative for improving clinical detection and promoting long-term quality of life. Fatigability, one’s perceived exertion after a standardized walking task, has been associated with declines in physical function; however, it remains unclear as to whether these effects may also extend to cognitive function.

Methods
We examined whether perceived fatigability, assessed as the rating of perceived exertion (RPE) after a 5 min slow-paced treadmill walk (0.67 m/s, 0% grade), is longitudinally associated with cognitive performance in the domains of memory, executive functions, language, and attention among 934 cognitively intact individuals aged at least 50 years participating in the Baltimore Longitudinal Study of Aging (BLSA); Mage = 69.6 ± 10.1, 51.9% female participants. Continuous associations between RPE and each domain (individual test and composite scores) were assessed using linear mixed-effect models adjusted for demographics and comorbid conditions.

Results
In fully adjusted models, higher fatigability at baseline was associated with declines in all cognitive domains over an average 2.2 years of follow-up (p &lt; .04 for all). Longitudinally, increased fatigability over time was associated with worsened executive functions (β= −0.01, p = .002).

Conclusions
These findings suggest that perceived fatigability after a standardized walking task may aid in identification of individuals at a higher risk of future cognitive decline. Future research should examine underlying biological mechanisms contributing to this relationship as well as whether future interventions may target fatigability in midlife to attenuate age-related cognitive decline.
Epidemiology of Perceived Physical Fatigability in Older Adults: The Long Life Family Study
Authors: LaSorda Kelsea R , Gmelin Theresa , Kuipers Allison L , Boudreau Robert M , Santanasto Adam J , Christensen Kaare , Renner Sharon W , Wojczynski Mary K , Andersen Stacy L , Cosentino Stephanie , Glynn Nancy W 
Published: December 2019

AbstractBackgroundFatigability is a construct that measures whole-body tiredness anchored to activities of a fixed intensity and duration; little is known about its epidemiology and heritability.MethodsTwo generations of family members enriched for exceptional longevity and their spouses were enrolled (2006–2009) in the Long Life Family Study (LLFS). At Visit 2 (2014–2017, N = 2,355) perceived physical fatigability was measured using the 10-item self-administered Pittsburgh Fatigability Scale (PFS), along with demographic, medical, behavioral, physical, and cognitive risk factors.ResultsResidual genetic heritability of fatigability was 0.263 (p = 6.6 × 10–9) after adjustment for age, sex, and field center. PFS physical scores (mean ± SD) and higher physical fatigability prevalence (% PFS ≥ 15) were greater with each age strata: 60–69 (n = 1,009, 11.0 ± 7.6, 28%), 70–79 (n = 847, 12.5 ± 8.1, 37%), 80–89 (n = 253, 19.3 ± 9.9, 65.2%), and 90–108 (n = 266, 28.6 ± 9.8, 89.5%), p &lt; .0001, adjusted for sex, field center, and family relatedness. Women had a higher prevalence of perceived physical fatigability compared to men, with the largest difference in the 80–89 age strata, 74.8% versus 53.5%, p &lt; .0001. Those with greater body mass index, worse physical and cognitive function, and lower physical activity had significantly higher perceived physical fatigability.ConclusionsPerceived physical fatigability is highly prevalent in older adults and strongly associated with age. The family design of LLFS allowed us to estimate the genetic heritability of perceived physical fatigability. Identifying risk factors associated with higher perceived physical fatigability can inform the development of targeted interventions for those most at risk, including older women, older adults with depression, and those who are less physically active.
Electromagnetic modelling with topography on regular grids with equivalent materials
Authors: Kamm Jochen , Becken Michael , Abreu Rafael 
Published: December 2019

SUMMARY
Maxwell’s equations are valid regardless of the choice of the coordinate system. By this property a change of coordinates can be equivalently expressed as a change of the material parameters. This idea opens a new approach to the problem of accurate electromagnetic modelling in the vicinity of steep topography or bathymetry. Via a change of coordinates, any earth model with complicated layer interfaces can be represented by an equivalent model where those interfaces are flat, but with its materials correspondingly altered. This new model could then be discretized on a regular mesh and fields could be computed by an appropriate finite difference or integral equation code. Unfortunately, this is not straightforward because both the new electric and magnetic materials are fully anisotropic. By instead applying a finite element secondary field approach to the equivalent model, we can completely account for the topography interface in the planar layered background model. The only modification required to existing finite element formulations is a slightly more complicated right-hand side of the linear system of equations, whereas the system matrix is unchanged in any coordinate system. In a numerical modelling experiment we confirm that our technique gives increased accuracy when compared with a recently published technique for dealing with topography in a secondary field formulation for the case of a magnetotelluric source field. In turn, in the vicinity of conductivity anomalies, accuracy can also be negatively affected.