bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dynamical phase transition in the activity-biased fully-connected random field Ising model: connection with glass-forming systems
Authors: Guioth Jules , Jack Robert L 
Published: October 2021

Abstract
We analyse biased ensembles of trajectories for the random-field Ising model on a fully-connected lattice, which is described exactly by mean-field theory. By coupling the activity of the system to a dynamical biasing field, we find a range of dynamical phase transitions, including spontaneous symmetry breaking into ordered states. For weak bias, the phase behaviour is controlled by extrema of the free energy, which may be local minima or saddle points. For large bias, the system tends to states of extremal activity, which may differ strongly from free energy minima. We discuss connections of these results to random first-order transition theory of glasses, which motivates an extension of the analysis to random-field Ising models where the dynamical activity is not symmetric under magnetisation reversal.
Investigation of interaction of extreme pressure additive, load and sliding speed parameters with silver nano-particles in wear environment
Authors: Ahmaida Yousef Alamin A , Korkmaz Seyma , Kilincarslan Sena Kabave , Sirvan Onur Can , Cetin M Huseyin 
Published: October 2021

Abstract
This study aims to minimize the wear of brass-based sliding bearing materials by using extreme-pressure and nano-silver added lubricants. The nano-fluids used in the experiments were characterized by the Zeta test, size measurement, absorbance graphs, wettability analyses and TEM imaging. The effect of extreme-pressure (5%, 10% and 15%) and nano-silver (1%, 5% and 9%) concentration ratios and the interaction of lubricants with load and speed parameters were analyzed with ball-on-plate wear experiments. The results were analyzed by evaluating the friction coefficient and wear volume values, as well as SEM and 3D topography images. It has been found that 5% extreme pressure lubricant reduces friction coefficient by 32.82% and volume loss by 89.51% compared to base lubricant. According to the results, the lowest friction coefficient (0.0276), volume loss (0.042 mm3) values and the best surface images were obtained at 1% concentration. Furthermore, the tribological performance decreased as the concentration of extreme-pressure and nano-silver increased, and optimum extreme-pressure and nano-silver concentrations were obtained as 5% and 1%, respectively. Using additives, different load (10N, 20N and 30N) and speed (10 rpm, 25 rpm, 40 rpm) parameters, Taguchi’s L9 fractional factorial experimental design was created for interaction analyses. With the Taguchi analysis of the design, 5% extreme pressure added lubricant, 10N load and 40 rpm speed parameter combination was determined as the optimum test condition and base lubricant, 30N load and 25 rpm speed parameters were determined as the worst test condition. According to the variance analyses results, it was determined that the lubricant condition was the most effective parameter on the coefficient of friction (67.79%), volume loss (51.07%) and surface roughness (45.43%).
Energy absorption within elastic range for AZ31 magnesium alloy
Authors: Yang Yongbiao , Zhang TingYan , Guo Jinxuan , Zhang Zhimin , Wang Qiang , Li Guojun 
Published: October 2021

Abstract
Energy absorption for AZ31 magnesium Alloy was investigated with Split Hopkinson Pressure Bar using single stress wave so as to avoid multiple stress wave loading. The stress wave amplitude, which was in elastic stress range and propagated along the AZ31 magnesium bar, was reduced with increasing propagating distance, and with increasing stress wave amplitude, the stress wave amplitude reduction along the magnesium bar was increased losing more energy as compared with that of the stress wave with lower amplitude. The drastically decreased stress wave amplitude could be explained based on dislocations movements, which was similar to the established theory of damping for the explanation of the energy loss during cyclic loading. However, it was not the case for LY12 aluminum alloy: the stress wave amplitude changed slightly without drastic energy loss regardless of the variation of stress wave amplitude.
Adhesion of water-based paint on plasma-treated high-density polyethylene sheets
Authors: De Leon Mark Jeffry D , Vasquez Magdaleno R 
Published: October 2021

Abstract
In this study, high-density polyethylene (HDPE) surfaces were treated with plasma to enhance the adhesion of a water-based paint. A custom-built cold atmospheric pressure plasma jet (CAPPJ) device using a neon transformer as its power source was developed and used in the surface treatment. The jet nozzle of the device was made from polytetrafluoroethylene with two bare stainless-steel electrodes positioned laterally through the nozzle and opposite each other with a 1 mm gap. Gas was allowed to pass through the nozzle, exiting through a 1 mm diameter hole where a plasma jet is ejected through the arc from the electrodes. The effect of plasma treatment on HDPE surfaces was determined. Air and nitrogen were used as the process gases and exposure times were also varied. Hydrophilicity of the surface increased with longer plasma exposure with a corresponding 50% increase in surface free energy compared to the untreated surface. From Fourier transform infrared and x-ray photoelectron spectroscopy analysis, it was seen that plasma treatment introduced oxygen containing functionalities onto the surface. Increase in adhesion of a water-based paint was observed for plasma-treated HDPE sheets.
Modelling and optimizing surface roughness and MRR in electropolishing of AISI 4340 low alloy steel in eco-friendly NaCl based electrolyte using RSM
Authors: Fallah Mohammad Meghdad , Attar Milad Aghaee , Mohammadpour Amir , Moradi Mahmoud , Barka Noureddine 
Published: October 2021

AbstractElectropolishing (EP) is a reliable post-processing method of the drilled metals for achieving a high-quality surface finish with an appropriate material removal rate. This process has many applications due to its advantages such as improving the surface quality by removing the surface peaks on a micro-scale. The aim of most attempts on this process is setting up the optimum parameters to obtain maximum Material Removal Rate (MRR) with minimum surface roughness. In the present wo k, electropolishing of AISI 4340 low alloy steel immersed in eco-friendly NaCl solution has been studied numerically and experimentally. So, primarily a simulation model was developed for the EP process on cylinder parts in COMSOL Multiphysics which was validated with experimental approaches. The results revealed that the numerical model would be convenient for EP. The experiments were performed using Response Surface Methodology (RSM) to evaluate the effect of input variables on the responses. The effects of input variables electrolyte temperature, current intensity, and primary gap were investigated on the outputs MRR and surface roughness at five levels. Based on the results, the electrolyte temperature and current intensity were more effective parameters on the outputs. Results of ANOVA and regression analysis approach revealed that by increasing the current and electrolyte temperature, the MRR increases correspondingly and surface roughness declines and the primary gap has a reverse effect on the MRR. Finally, by performing a multi-objective optimization using Derringer’s desirability approach, the EP of AISI 4340 with an eco-friendly NaCl solution was optimized.
Growth kinetics of (CuxNi1-x)6Sn5 intermetallic compound at the interface of mixed Sn63Pb37/SAC305 BGA solder joints during thermal aging test
Authors: Cong Sen , Zhang Weiwei , Zhang He , Liu Peng , Tan Xingwen , Wu Lang , An Rong , Tian Yanhong 
Published: October 2021

Abstract
Sn63Pb37/SAC305 mixed solder joint is inevitably in the electronic device requiring high reliability, such as health care, aerospace etc. However, the usage history of mixed solder joint is relatively short and as such their interfacial behaviour and reliability in service has not been completely figure out. Herein, the evolution of microstructures in fully mixed Sn63Pb37/SAC305 BGA solder joints during high-temperature storage were systematically studied. After reflow soldering process, the Pb-rich phases uniformly distributed in the fully mixed joint. During the thermal aging test, the size of Pb-rich phases gradually coarsened. The intermetallic compound (IMC) layers thickness at the two-side interface (upper interface: between the pad on substrate and solder; lower interface: between the pad on PCB and solder) were also increased. Moreover, the growth kinetics models of two-side IMC layer were successfully established according to the Arrhenius equation. IMC layer grows faster at higher temperature, because of higher diffusion coefficient. With the increasing of aging time, the fracture position partially moved from the interface between Ni layer and IMC layer into IMC internal. These results may provide support for the reliable applications of mixed Sn63Pb37/SAC305 solder joints.
Temperature impact on device characteristics of charge plasma based tunnel FET with Si0.5Ge0.5 source
Authors: Mishra Varun , Verma Yogesh Kumar , Agarwal Lucky , Gupta Santosh Kumar 
Published: October 2021

Abstract
In this work, the impact of temperature is investigated on the electrical characteristics of charge plasma-based doping-less double gate tunnel FET (DL-DG-TFET) with a low bandgap source material i.e., Si0.5Ge0.5. The influence of temperature (from 250 K to 450 K) is analysed on several performance parameters of the device such as bandgap, threshold voltage, SS, switching current ratio, ID-VGS, ID-VDS, gate current. The small change in energy bandgap with temperature reflects that device is minimally dependent on temperature. Temperature impact is significant on the sub-threshold region of transfer characteristics due to SRH recombination and trap-assisted tunnelling current. Insignificant variation of gate current with temperature signifies the better reliability of the device. Further, temperature effect is observed on analog parameters such as cut-off frequency, gate capacitance, trans-conductance, output conductance, power delay product (PDP). The minimal variation of analog parameters with temperature assures application of device in high-temperatures.
Machine learning the derivative discontinuity of density-functional theory
Authors: Gedeon Johannes , Schmidt Jonathan , Hodgson Matthew J P , Wetherell Jack , Benavides-Riveros Carlos L , Marques Miguel A L 
Published: October 2021

Abstract
Machine learning is a powerful tool to design accurate, highly non-local, exchange-correlation functionals for density functional theory. So far, most of those machine learned functionals are trained for systems with an integer number of particles. As such, they are unable to reproduce some crucial and fundamental aspects, such as the explicit dependency of the functionals on the particle number or the infamous derivative discontinuity at integer particle numbers. Here we propose a solution to these problems by training a neural network as the universal functional of density-functional theory that (a) depends explicitly on the number of particles with a piece-wise linearity between the integer numbers and (b) reproduces the derivative discontinuity of the exchange-correlation energy. This is achieved by using an ensemble formalism, a training set containing fractional densities, and an explicitly discontinuous formulation.
Tukey reductions of nowhere Ramsey to Silver null sets
Authors: Spinas Otmar 
Published: October 2021

We prove that the ideal of nowhere Ramsey sets is Tukey reducible to each of the finite-dimensional Silver null ideals. This is in line with an earlier result of the author [Israel J. Math. 211 (2016), pp. 473–480] that the meager ideal is Tukey reducible to the Silver null ideal, and it answers two questions asked by Spinas and Wohofsky [Fund. Math. 254 (2021), pp. 261–303].

We also show that if the homogeneity number

h
m

\mathfrak {hm}

equals

2

ℵ
0

2^{\aleph _0}

, then the additivity of the Marczewski ideal is below the

σ
\sigma

-splitting number

s
σ

\mathfrak {s_\sigma }

.
Stigma shape shifting in sages (Salvia: Lamiaceae): hummingbirds guided the evolution of New World floral features
Authors: Kriebel Ricardo , Drew Bryan T , González-Gallegos Jesús G , Celep Ferhat , Antar Guilherme M , Pastore José Floriano Barêa , Uría Rolando , Sytsma Kenneth J 
Published: October 2021

AbstractA fundamental question in evolutionary biology is how clades of organisms exert influence on one another. The evolution of the flower and subsequent plant/pollinator coevolution are major innovations that have operated in flowering plants to promote species radiations at a variety of taxonomic levels in the Neotropics. Here we test the hypothesis that pollination by Neotropical endemic hummingbirds drove the evolution of two unique stigma traits in correlation with other floral traits in New World Salvia (Lamiaceae). We examined morphometric shapes of stigma lobing across 400 Salvia spp., scored presence and absence of a stigma brush across Salvia, and used a suite of phylogenetic comparative methods to detect shape regime shifts, correlation of trait shifts with BayesTraits and phylogenetic generalized least square regressions, and the influence of scored pollinators on trait evolution using OUwie. We found that a major Neotropical clade of Salvia evolved a correlated set of stigma features, with a longer upper stigma lobe and stigmatic brush, following an early shift to hummingbird pollination. Evolutionary constraint is evident as subsequent shifts to bee pollination largely retained these two features. Our results support the hypothesis that hummingbirds guided the correlative shifts in corolla, anther connective, style and stigma shape in Neotropical Salvia, despite repeated shifts back to bee pollination.
Impact of the COVID-19 pandemic on emergent pacemaker implantation during lockdown and its aftermath
Authors: De Almeida Fernandes D , Cadete R , Guimaraes J , Monteiro E , Costa G , Antonio N , Goncalves L 
Published: October 2021

Abstract

Background
COVID-19 was first considered a pandemic on the 11th of March of 2020 by the World Health Organization. Its impact comprised not only the direct consequences of the disease but a decrease in the follow-up and interventions of patients with cardiovascular (CV) disease. In Portugal and the World, the consequences of this complex paradigm shift on emergent pacemaker implantation rates during and after this pandemic is largely unknown.

Purpose
We sought to analyse the impact of COVID-19 pandemic on emergent pacemaker implantation rate and patient profile in a tertiary hospital during the first Portuguese lockdown and subsequent post-lockdown period.

Methods
We retrospectively reviewed the clinical profile of patients who had pacemakers implanted in our hospital in an urgent/emergent setting from March 18, 2020 to May 17, 2020 (lockdown) and May 19 to July 17, 2020 (post-lockdown). This data was then directly compared to the homologous periods from the year before (H1 and H2, respectively).

Results
A total of 180 patients submitted to emergent pacemaker implantation were included.
The cohort was comprised of 29 patients who had a pacemaker implanted during lockdown, 60 post-lockdown, 38 in H1 (+31% vs lockdown) and 53 in H2. Average age and gender proportion were similar for all groups.
When comparing lockdown and post-lockdown periods, the number of cases significantly increased in the second period (+106.9%) and there was a tendency for a higher number of temporary pacemaker use (3.4% vs 16.7%; p=0.076). Patients admitted during lockdown were 7.57 times more likely to present with hypotension/shock (odds ratio (OR) 7.57; p=0.013).
Regarding lockdown and its homologous 2019 period, there was a decrease in the number of patients admitted (−23.7%). Again, there was a higher tendency for hypotension on presentation during lockdown (p=0.054).
In comparison to its homologous 2019 period, post-lockdown saw a slight increase in the number of patients (+13.2%) and more patients presented with bradycardia (16.7% vs 3.8%; p=0.026).
Also of note, no patients were admitted to the emergency department during lockdown for anomalies detected on ambulatory tests (Holter, electrocardiogram or implanted loop recorder).

Conclusion
During lockdown, clinical presentation was generally more severe, with a greater number of patients presenting with hypotension/shock. In addition, there appears to be a lockdown effect on emergent bradyarrhtmias admissions in the post-lockdown period with a profound impact: higher admission rates and more severe presentations including a higher need of temporary pacemaker. Patients with symptoms suggestive of bradyarrhythmias should be advised to present promptly regardless of the pandemic.

Funding Acknowledgement
Type of funding sources: None. Pacemakers during lockdown/post-lockdownPacemakers implanted by diagnosis
Unveiling the impact of fibrosis presence in fibrillatory electrograms
Authors: Rios-Munoz G R , Sanchez De La Nava A M , Gomez-Cid L , Grigorian-Shamagian L , Fernandez-Santos M E , Atienza F , Arenal A , Fernandez-Aviles F 
Published: October 2021

Abstract

Introduction
Complexity and fragmentation presence in atrial fibrillation (AF) electrograms (EGMs) has been extensively studied in the literature, with areas exhibiting complex fractionated atrial electrograms (CFAEs) postulated as responsible for AF maintenance. Computational simulations based on in silico models are widely employed to support AF initiating and maintenance theories. However, they are still limited when trying to mimic the effect of fibrosis in live cardiac cells and its impact in the clinical context, i.e., EGM morphologies in electroanatomical mapping studies. Controlled experiments on cultivated cardiomyocytes and optical mapping signals can better explain the role of fibrosis and its effect on EGM recordings.

Purpose
To study the effect of fibrosis in fibrillatory scenarios by comparing the temporal and frequency domains of EGMs and Ca2+ transient signals in cardiomyocyte cell cultures.

Methods
A total of 51 HL1 cardiomyocytes cell line monolayers experiments were cultured until confluence. Optical mapping (OM) was performed to evaluate the electrophysiological activity of the samples through Ca2+ transient quantification under the effect of Rhod2 dye. Activation frequency and calcium transient signals were acquired, and virtual EGMs were calculated from the signals virtually after post-processing the cell cultures at 16 different positions in the culture, see Figure 1A.

Results
The DF ratio between the OM and the virtual EGMs obtained for the different fibrosis levels are summarized and represented in Figure 1B. The Pearson's correlation coefficient was adjusted for all the samples and the significance level was stablished at p-value&lt;0.01.

Conclusions
Optical mapping signal morphologies strongly correlate with EGM recordings when a clear dominant frequency (DF) dominates the complete area of the cell culture and no fibrosis is present. However, for patchy distributions of the DF, usually associated with higher concentrations of fibrosis, morphologies do not correlate for increasing fibrosis levels, and DF measurements differ with poor match between EGM-DF and OM-DF. Results on higher fibrotic experiments, i.e., 40–50% fibrosis level, show that DF correlates due to the poor and degraded cardiac activity in the EGMs and optical mapping recordings. The results reveal the importance and impact of fibrosis in the remodeling of atrial tissue and the correct interpretation of endocardial EGMs in the presence of heterogeneous tissue.

Funding Acknowledgement
Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Instituto de Salud Carlos III and Ministerio de Ciencia, Innovaciόn y Universidades
Epidemiology of subclinical atrial fibrillation in patients with cardiac implantable electronic devices: a systematic review and meta-analysis
Authors: Romiti G F , Corica B , Borgi M , Vitolo M , Miyazawa K , Healey J S , Lane D A , Boriani G , Basili S , Lip G Y H , Proietti M 
Published: October 2021

Abstract

Background
Sub-clinical atrial fibrillation (SCAF) and atrial high-rate episodes (AHREs), seen as high-frequency atrial tachyarrhythmias in patients with cardiac implantable electronic devices (CIEDs), have gained prominence as determinants of clinical atrial fibrillation (AF) and increased stroke risk. As a result, several studies investigating their role in predicting the onset of AF and AHRE-related outcomes have been conducted but uncertainty exists on the epidemiology of AHRE.

Purpose
To estimate the incidence of SCAF, according to presence of AHREs in patients with CIEDs, through a systematic review and meta-analysis of the available literature.

Methods
PubMed and EMBASE were searched from inception to 27th January 2021 for all studies documenting the incidence of AHREs in patients with CIEDs. We included all studies with ≥100 patients reporting data on AHREs incidence. Pooled prevalence and incidence rates were computed; we also performed meta-regressions for pooled incidence rates, according to relevant study-level characteristics. This study was registered in PROSPERO: CRD42019106994.

Results
Among the 2,515 results retrieved, we included 51 studies in the systematic review and meta-analysis, with a total of 68,414 patients. Meta-analysis of included studies showed a pooled prevalence of 28.2% (95% CI: 24.3–32.5%, I2=99%), with a pooled incidence rate (IR) of 15 new AHRE cases per 100 patient-years (95% CI: 12–19, I2=100%). Given the large heterogeneity showed in the pooled estimates we performed additional analyses. Regarding pooled prevalence, we performed several subgroup analyses, according to various studies baseline characteristics, which did not show any significant difference in any of the subgroups examined. Regarding IR, a multivariable meta-regression analysis showed that decreasing follow-up time and increasing age were the only factors significantly associated with AHRE incidence, explaining a large proportion of heterogeneity (R2=68%, p&lt;0.001; Figure 1, Panel A and B respectively). Accordingly, the AHRE IR was highest at 1 year follow-up and in the oldest subjects. Presence of SCAF was significantly associated with older age, higher CHA2DS2-VASc score, and higher prevalence of hypertension, heart failure and history of cerebrovascular disease.

Conclusions
This systematic review and meta-regression demonstrated that SCAF is very common in patients with CIEDs, with an overall IR for AHREs of up to 15 per 100 patient-years; increasing with age and decreasing with longer follow-up time. Presence of SCAF was associated with an overall higher clinical risk profile compared to those subjects without SCAF.

Funding Acknowledgement
Type of funding sources: None. Figure 1. Meta-regression for AHRE Incidence