bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dynamic effects of low-velocity impact on composite plates
Authors: Wang R , Chen D D , Zhu M , Xing S L 
Published: October 2019

Abstract
In low-velocity impact research on composites, quasi-static indentation experiments are typically used to make inner fractures. However, dynamic effects caused by impacts cannot be studied by quasi-static experiments. In this paper, the dynamic effects are discussed using simulation. Low-velocity impact processes were simulated through ABAQUS/Explicit software. Quasi-static processes were also simulated with ABAQUS/Explicit, in which very-low-speed displacement loadings were adopted to ensure that the kinetic energy could be ignored. The results show nearly no dynamic effect in the thickness direction, due to the thin nature of the composite plate and high-stress wave velocity in the through-the-thickness direction. In the radial direction, in contrast, apparent dynamic effects are observed, although the associated stress wave velocity is much higher. This may be attributed to the wave propagation from the impact site to the edge of the plate, reflecting repeatedly between the top and bottom surfaces of the plate.
Estimation of aircraft magnetic field model coefficient under Geomagnetic Gradient Change
Authors: Li C J , Zhang B , Ouyang T H , Gong Y Z , Li B 
Published: October 2019

AbstractTraditional airplane magnetic field models simplify geomagnetic field values as constants, overlooking changes to the model coefficient brought by gradually variational magnetic field which reduces the model accuracy. This paper puts forward an aircraft magnetic field model under geomagnetic gradient change. The geomagnetic gradient change is adopted the truncated singular value decomposition (TSVD) to solve multicollinearity in the model solving. It is proposed to use the coefficient obtained from the truncated singular value as initial conditions and utilize recursive damped least square (RDLS) to conduct adaptive adjustment to model coefficients aiming at the coefficient variation of induction field and Eddy Current Field caused by the geomagnetic field. The simulation outcome indicates that the method boasts a high magnetic compensation effect.
Investigation on characteristics of arc extinguishing time of a new lighting protection gap for transmission lines
Authors: Yan R B , Wang J F , Li Z J , Huang SS 
Published: October 2019

Abstract
The present research envisages the development of a novel arc extinguishing lightning protection gap in pursuit of reducing the lightning trip-out rate and accident rate. In the developed setup, the jetting stream arc extinction lightning protection gap device was used for transmission line. When this transmission line was struck by lightning and the lightning surge was going to break down the gap, the arc extinguishing lightning protection gap immediately jetted out sufficient electronegative gas flow that quickly cut off the arc and effectively prevented the insulator from being damaged by the arc. Furthermore, when the line was attacked by lightning, the generated overvoltage instantaneously broke the gap that was parallel to the insulator string, so that the lightning current was oriented to the earth from the gap. Simultaneously, it triggered the gas generator and generated a high speed stream, then extinguished the frequency continuous current arc rapidly, thus effectively reducing the rate of line trip to ensure the reliability of power supply. We used a high-speed camera and ordinary camera that automatically captured the process of the jetting stream arc in the extinction lightning protection gap device, while extinguishing the 1kA power frequency arc. The image of the high-speed camera indicated that the power frequency arc of 1kA was quenched in 10 ms before the relay protection action of the test loop, which made that the overhead line lightning flashover but the circuit breaker did not trip. Thus, a reduction in the rate of lightning trip was observed by the developed setup, and it has an immense potential for application at the transmission lines of China.
Simulation on temperature field of initial segment of electromagnetic rail launch
Authors: Tong S Y , Feng G , Lian Z M , Cheng J S 
Published: October 2019

Abstract
The temperature field analysis of electromagnetic rail launcher is an important basis for studying the launching stability and life. Aiming at the rail groove erosion phenomenon, the launching initial segment is selected as the research site. The heat generation mechanism of Joule heat and friction heat is analyzed, the heat source model is established, the three-dimensional finite element simulation model is established and the position, velocity and current waveform of the launching initial section are determined according to the circuit simulation, the finite element simulation results show that the heat in the initial stage of launching mainly concentrates on the contact surface between armature and rail. The friction heat is the main factor affecting the temperature rise of the contact surface, and the uneven distribution of the current density will lead to the uneven temperature distribution of the contact surface.
Numerical simulation of heavy truck’s aerodynamic noise
Authors: Liu J , Zhuang C , Liu S , Zhou H M 
Published: October 2019

Abstract
A 3D numerical simulation is built on heavy truck including cab, frame, and tires. And vehicle exterior flow field in steady state is computed by computational fluid dynamics software. In the computation process, the distribution of sound power levels on the surface of vehicle body as well as the connection between sound power level and vehicle speed are obtained from aerodynamic noise source, which is using broadband noise source models. Taking the steady flow field results as original values, the exterior flow field computations in transient state are performed by large eddy simulation. Based on the transient fluid field, the near field aerodynamic noise from cab accessories is predicted using FW-H model, and the comparison of the simulation results and the test results is carried out. The results show that the aerodynamic noise sources are from the upwind side with a great pressure gradient. Attentions should be paid more on rearview mirror, diversion trench and sun visor for Aerodynamic noise optimization of heavy truck. The maximum sound power level of aerodynamic noise in vehicle body accessories is quadratic to vehicle speed. And the aerodynamic noise of heavy trucks is analysed by numerical simulation, in which noise distribution law is consistent with the test. Therefore, the numerical simulation can be adopted to provide the guidance for the design of vehicle body with low noise.
Numerical simulation of dendritic evolution based on an improved cellular automaton model involving solute field
Authors: Wang J J , Meng H J , Yang J , Xie Z 
Published: October 2019

Abstract
This paper studied the single crystal growth of Fe-0.64C alloy under a fixed cooling rate, proposed an improved cellular automaton model. The influence of solute field on dendrite growth is especially considered into the model. And a new solute distribution scheme based on Fick's first law and solute conservation was proposed from the microscopic scale. In addition, the present work improved the acquisition algorithm, which takes the growth length of the interface cell to the neighbouring cell as the determination condition of the capture. A solid fraction calculation method based on the solidification area of interface cell to total area is also proposed. The results show that this model can not only dynamically display the formation process of secondary dendrites and high-order dendrites, but also simulate the distribution of solute inside the dendrites and at the interface front.
The rolling contact research of three dimensional wheel-rail based on finite element analysis
Authors: Tian J H , Jing G Q , Lu X X , Xiao K , Zhang H R 
Published: October 2019

Abstract
In this paper, wheel-rail contact model was established and analyzed, some useful results were obtained. The results show that In the early stage of wheel-rail contact, the wheel-rail contact pressure increases gradually and the contact point shape changes from regular polygon to irregular polygon in the process of wheel approaching rail joint. The equivalent stress and elastic deformation trend of the rail are basically the same, both of which decrease rapidly and then slowly increase. The plastic deformation of the rail gradually increases and accumulates, and the stress concentration area occurs at the side of the rail joint. When the wheel starts rolling, the equivalent stress of the wheel gradually decreases at first, and then increase. The peak value of the maximum equivalent stress occurs at the joint where the wheel reaches the rail.
Stability of Sn based inorganic perovskite quantum dots
Authors: Pradeep K R , Chakraborty Saptarshi , Viswanatha Ranjani 
Published: October 2019

Abstract
Metal halide perovskite crystal structures have emerged as a class of optoelectronic materials, which combine the ease of solution processability with excellent optical absorption and emission qualities. However, the most promising perovskite structures rely on lead as a cationic species, thereby hindering commercial application. The replacement of lead with non-toxic alternatives such as tin has been studied in bulk but not in nanocrystals. In this work, we synthesize Sn and Pb based alloy perovskite nanocrystals by direct synthesis method, taking mixture of Pb and Sn precursors in the desired ratio leading to quantum dots (QDs) of CsPb1−xSnxBryI3−y with successful Sn incorporation into the host lattice. As colloidal stability of these QDs is a crucial factor for device applications, we have studied the stability of the QDs under different conditions for these Sn based QDs and have found them to degrade faster upon using anti-solvents during washing process. In order to stabilize them, we have devised a purification method that is also discussed. Further, even though the optical and crystal structure stability in some of the inorganic perovskites leaves much room for improvement, so far there have been no studies on the structure property correlation. Here we study their structural purity and their optical stability after understanding the structure property correlation in CsPbI3 and CsPbBr3 perovskite structures. The stability of Sn doped perovskites obtained from a logical understanding of structure property correlation is found to be extremely stable across the series of compounds for upto three months.
Time trends in sudden cardiac death risk in heart failure patients with cardiac resynchronization therapy: a systematic review
Authors: Barra Sérgio , Providência Rui , Narayanan Kumar , Boveda Serge , Duehmke Rudolf , Garcia Rodrigue , Leyva Francisco , Roger Véronique , Jouven Xavier , Agarwal Sharad , Levy Wayne C , Marijon Eloi 
Published: October 2019

Abstract

Aims
While data from randomized trials suggest a declining incidence of sudden cardiac death (SCD) among heart failure patients, the extent to which such a trend is present among patients with cardiac resynchronization therapy (CRT) has not been evaluated. We therefore assessed changes in SCD incidence, and associated factors, in CRT recipients over the last 20 years.

Methods and results
Literature search from inception to 30 April 2018 for observational and randomized studies involving CRT patients, with or without defibrillator, providing specific cause-of-death data. Sudden cardiac death was the primary endpoint. For each study, rate of SCD per 1000 patient-years of follow-up was calculated. Trend line graphs were subsequently constructed to assess change in SCD rates over time, which were further analysed by device type, patient characteristics, and medical therapy. Fifty-three studies, comprising 22 351 patients with 60 879 patient-years of follow-up and a total of 585 SCD, were included. There was a gradual decrease in SCD rates since the early 2000s in both randomized and observational studies, with rates falling more than four-fold. The rate of decline in SCD was steeper than that of all-cause mortality, and accordingly, the proportion of deaths which were due to SCD declined over the years. The magnitude of absolute decline in SCD was more prominent among CRT-pacemaker (CRT-P) patients compared to those receiving CRT-defibrillator (CRT-D), with the difference in SCD rates between CRT-P and CRT-D decreasing considerably over time. There was a progressive increase in age, use of beta-blockers, and left ventricular ejection fraction, and conversely, a decrease in QRS duration and antiarrhythmic drug use.

Conclusion
Sudden cardiac death rates have progressively declined in the CRT heart failure population over time, with the difference between CRT-D vs. CRT-P recipients narrowing considerably.
Molecular signature of cardiogenic shock
Authors: Iborra-Egea Oriol , Rueda Ferran , García-García Cosme , Borràs Eva , Sabidó Eduard , Bayes-Genis Antoni 
Published: October 2019

AbstractThe incidence of cardiogenic shock (CS) has increased remarkably over the past decade and remains a challenging condition with mortality rates of ∼50%. Cardiogenic shock encompasses cardiac contractile dysfunction; however, it is also a multiorgan dysfunction syndrome, often complicated by a systemic inflammatory response with severe cellular and metabolic dysregulations. Here, we review the evidence on the biochemical manifestations of CS, elaborating on current gold standard biomarkers and novel candidates from molecular signatures of CS. Glucose and lactate, both identified over a century ago, remain the only clinically used biomarkers in current predictive risk scores. Novel genomic, transcriptomic, and proteomic data are discussed, and a recently reported molecular score derived from unbiased proteomic discovery, the CS4P, which includes liver fatty acid-binding protein, beta-2-microglobulin, fructose-bisphosphate aldolase B, and SerpinG1 is comprehensively described. Recent advances in -omics technologies provide new insight into a more holistic molecular signature of CS. Thus, we need to open new diagnostic and therapeutic avenues if we aim to improve outcomes.
Pharmacodynamics, pharmacokinetics, and safety of single-dose subcutaneous administration of selatogrel, a novel P2Y12 receptor antagonist, in patients with chronic coronary syndromes
Authors: Storey Robert F , Gurbel Paul A , ten Berg Jurrien , Bernaud Corine , Dangas George D , Frenoux Jean-Marie , Gorog Diana A , Hmissi Abdel , Kunadian Vijay , James Stefan K , Tanguay Jean-Francois , Tran Henry , Trenk Dietmar , Ufer Mike , Van der Harst Pim , Van't Hof Arnoud W J , Angiolillo Dominick J 
Published: October 2019

Abstract

Aims
To study the pharmacodynamics and pharmacokinetics of selatogrel, a novel P2Y12 receptor antagonist for subcutaneous administration, in patients with chronic coronary syndromes (CCS).

Methods and results
In this double-blind, randomized study of 345 patients with CCS on background oral antiplatelet therapy, subcutaneous selatogrel (8 mg, n = 114; or 16 mg, n = 115) was compared with placebo (n = 116) (ClinicalTrials.gov: NCT03384966). Platelet aggregation was assessed over 24 h (VerifyNow assay) and 8 h (light transmittance aggregometry; LTA). Pharmacodynamic responders were defined as patients having P2Y12 reaction units (PRU) &lt;100 at 30 min post-dose and lasting ≥3 h. At 30 min post-dose, 89% of patients were responders to selatogrel 8 mg, 90% to selatogrel 16 mg, and 16% to placebo (P &lt; 0.0001). PRU values (mean ± standard deviation) were 10 ± 25 (8 mg), 4 ± 10 (16 mg), and 163 ± 73 (placebo) at 15 min and remained &lt;100 up to 8 h for both doses, returning to pre-dose or near pre-dose levels by 24 h post-dose. LTA data showed similarly rapid and potent inhibition of platelet aggregation. Selatogrel plasma concentrations peaked ∼30 min post-dose. Selatogrel was safe and well-tolerated with transient dyspnoea occurring overall in 7% (16/229) of patients (95% confidence interval: 4–11%).

Conclusions
Selatogrel was rapidly absorbed following subcutaneous administration in CCS patients, providing prompt, potent, and consistent platelet P2Y12 inhibition sustained for ≥8 h and reversible within 24 h. Further studies of subcutaneous selatogrel are warranted in clinical scenarios where rapid platelet inhibition is desirable.
Effects of Transcranial Direct Current Stimulation on Episodic Memory in Older Adults: A Meta-analysis
Authors: Huo Lijuan , Zhu Xinyi , Zheng Zhiwei , Ma Jialing , Ma Zhuoya , Gui Wenjun , Li Juan 
Published: October 2019

Abstract

Objectives
In the last two decades, the number of intervention studies using transcranial direct current stimulation (tDCS) has grown enormously. Though some studies have shown positive influences on episodic memory among older adults, disagreement exists in the literature. Therefore, the current meta-analysis aimed to provide a quantitative assessment of the efficacy of tDCS in modulating episodic memory functions in older adults.

Method
Eligible studies were sham-controlled trials examining the effects of anodal tDCS on episodic memory in older adults. Twenty-four articles comprising 566 participants aged over 60 qualified for inclusion.

Results
Compared to the sham tDCS group, the active tDCS group showed significant memory improvements at both immediate poststimulation (Hedges’ g = 0.625, p = .001) and long-term follow-up (Hedges’ g = 0.404, p = .002). There were no differences in effect sizes between cognitively healthy and impaired older adults. Moderator analyses suggested that tDCS having a duration of 20 min or less, bilateral stimulation, or a larger stimulation area would produce greater benefits for episodic memory performance in older adults.

Discussion
These findings suggest that tDCS holds great promise to ameliorate memory decline in older individuals. In the future, well-designed randomized controlled trials are expected to verify the optimal stimulation protocols and determine the factors impacting the long-term effects of tDCS in enhancing episodic memory.
Personhood and Dementia Care: A Qualitative Evidence Synthesis of the Perspectives of People With Dementia
Authors: Hennelly Niamh , Cooney Adeline , Houghton Catherine , O’Shea Eamon 
Published: October 2019

Abstract

Background and Objectives
Personhood is considered the cornerstone of person-centered care for people with dementia. However, there is little research on personhood in dementia care from the perspective of the person with dementia themselves. This article presents a qualitative evidence synthesis of the experiences and perceptions of people with dementia on personhood in dementia care.

Research Design and Methods
A systematic search of nine databases was conducted. In addition to initial screening, CART analysis was used to determine the most relevant papers. Thematic synthesis was conducted on 20 papers. The CASP tool was used to examine the quality of the included papers. GRADE CERQual analysis examined confidence in the review findings.

Results
People with dementia experience many changes due to the disease and the experience of being cared for in different settings. Personhood is affirmed through personal interactions with family, friends, other care recipients, and formal caregivers, as well as through continued engagement in social and occupational roles.

Discussion and Implications
The review has important implications for practice, regulation, and policy. The person and their personhood should be protected rather than undermined, and relationships should be enhanced not diminished by the formal care process. The focus should be on creating and amplifying opportunities for people with dementia to affirm the self through interactions with others and engaging in occupational and social roles to ensure continuity of self.
Hidden health IT hazards: a qualitative analysis of clinically meaningful documentation discrepancies at transfer out of the pediatric intensive care unit
Authors: Orenstein Evan W , Ferro Daria F , Bonafide Christopher P , Landrigan Christopher P , Gillespie Scott , Muthu Naveen 
Published: October 2019

Abstract

Objective
The risk of medical errors increases upon transfer out of the intensive care unit (ICU). Discrepancies in the documented care plan between notes at the time of transfer may contribute to communication errors. We sought to determine the frequency of clinically meaningful discrepancies in the documented care plan for patients transferred from the pediatric ICU to the medical wards and identified risk factors.

Materials and Methods
Two physician reviewers independently compared the transfer note and handoff document of 50 randomly selected transfers. Clinically meaningful discrepancies in the care plan between these two documents were identified using a coding procedure adapted from healthcare failure mode and effects analysis. We assessed the influence of risk factors via multivariable regression.

Results
We identified 34 clinically meaningful discrepancies in 50 patient transfers. Fourteen transfers (28%) had ≥1 discrepancy, and ≥2 were present in 7 transfers (14%). The most common discrepancy categories were differences in situational awareness notifications and documented current therapy. Transfers with handoff document length in the top quartile had 10.6 (95% CI: 1.2–90.2) times more predicted discrepancies than transfers with handoff length in the bottom quartile. Patients receiving more medications in the 24 hours prior to transfer had higher discrepancy counts, with each additional medication increasing the predicted number of discrepancies by 17% (95% CI: 6%–29%).

Conclusion
Clinically meaningful discrepancies in the documented care plan pose legitimate safety concerns and are common at the time of transfer out of the ICU among complex patients.
Modelling the photometric variability of magnetic massive stars with the Analytical Dynamical Magnetosphere model
Authors: Munoz M S , Wade G A , Nazé Y , Puls J , Bagnulo S , Szymański M K 
Published: October 2019

Abstract
In this paper, we investigate the photometric variability of magnetic O-type stars. Such stars possess oblique, predominantly dipolar magnetic fields that confine their winds roughly axisymmetrically about the magnetic equator, thus forming a magnetosphere. We interpret their photometric variability as phase-dependent magnetospheric occultations. For massive star winds dominated by electron scattering opacity in the optical and NIR, we can compute synthetic light curves from simply knowing the magnetosphere’s mass density distribution. We exploit the newly-developed Analytical Dynamical Magnetosphere model (ADM) in order to obtain the predicted circumstellar density structures of magnetic O-type stars. The simplicity in our light curve synthesis model allows us to readily conduct a parameter space study. For validation purposes, we first apply our algorithm to HD 191612, the prototypical Of?p star. Next, we attempt to model the photometric variability of the Of?p-type stars identified in the Magellanic Clouds using OGLE photometry. We evaluate the compatibility of the ADM predictions with the observed photometric variations, and discuss the magnetic field properties that are implied by our modelling.