bluuebunny/crossref_metadata_2025 huggingface dataset:
Electromechanical Model-Based Adaptive Control of Multilayered Dielectric Elastomer Bending Actuator
Authors: Zhou Fanghao , He Jin , Zhang Mingqi , Xiao Youhua , Chen Zheng , Wong Tuck-Whye , Li Tiefeng , Xu Zhongbin , Luo Yingwu
Published: July 2021

Dielectric elastomer (DE) possesses attributes such as large deformation and fast response. As a typical DE actuating structure, the multilayered DE bending actuator (MDEBA) is lightweight and can actuate in relatively low voltage without a rigid frame and pre-stretch. These attributes arouse wide research interest in the MDEBA on the application of soft robots. However, due to its large deformation and nonlinear electromechanical dynamics, the control of MDEBA remains highly challenged. Considering the large bending deformation and gravity effect, we develop an electromechanical dynamic model-based control strategy, which can adaptively compensate for the parameter uncertainties during the actuation of MDEBA. Experimental results validate that this control strategy provides highly enhanced control performance compared to the proportional integral derivative (PID) controller. The electromechanical modeling method and dynamic control strategy may guide the further study of MDEBA, soft robots, and flexible devices.
Cyber-Physical System Implementation for Manufacturing With Analytics in the Cloud Layer
Authors: Parto Mahmoud , Urbina Coronado Pedro Daniel , Saldana Christopher , Kurfess Thomas
Published: July 2021

Effective and efficient modern manufacturing operations require the acceptance and incorporation of the fourth industrial revolution, also known as Industry 4.0. Traditional shop floors are evolving their production into smart factories. To continue this trend, a specific architecture for the cyber-physical system is required, as well as a systematic approach to automate the application of algorithms and transform the acquired data into useful information. This work makes use of an approach that distinguishes three layers that are part of the existing Industry 4.0 paradigm: edge, fog, and cloud. Each of the layers performs computational operations, transforming the data produced in the smart factory into useful information. Trained or untrained methods for data analytics can be incorporated into the architecture. A case study is presented in which a real-time statistical control process algorithm based on control charts was implemented. The algorithm automatically detects changes in the material being processed in a computerized numerical control (CNC) machine. The algorithm implemented in the proposed architecture yielded short response times. The performance was effective since it automatically adapted to the machining of aluminum and then detected when the material was switched to steel. The data were backed up in a database that would allow traceability to the line of g-code that performed the machining.
Application of Wray–Agarwal Turbulence Model for Numerical Simulation of Gas-Solid Flows in Circulating Fluidized Bed Risers
Authors: Shao Yali , Agarwal Ramesh K. , Wang Xudong , Jin Baosheng
Published: July 2021

In recent decades, increasing attention has been paid on accurate modeling of circulating fluidized bed (CFB) risers to provide valuable guidance to design, optimization, and operation of reactors. Turbulence model plays an important role in the accurate prediction of complex gas-solid flows. Recently developed Wray–Agarwal (WA) model is a one-equation turbulence model with the advantages of high computational efficiency and competitive accuracy with two-equation models. In this paper for the first time, the Eulerian–Eulerian approach coupled with different turbulence models including WA model, standard κ–ɛ model, and shear stress transport (SST) κ–ω model is employed to simulate two-phase flows of gas phase and solid phase in two CFB risers, in order to assess accuracy and efficiency of WA model compared to other well-known two-equation models. Predicted gas-solid flow dynamic characteristics including the gas-solid volume fraction distributions in radial and axial directions, pressure profiles, and solid mass flux distributions are compared with data obtained from an experiment in detail. The results demonstrate that the WA model is very promising for accurate and efficient simulation of gas-solid multiphase flows.
Factors Impacting Highly Innovative Designs: Idea Fluency, Timing, and Order
Authors: Mirabito Yakira , Goucher-Lambert Kosa
Published: July 2021

Ongoing work within the engineering design research community seeks to develop automated design methods and tools that enhance the natural capabilities of designers in developing highly innovative concepts. Central to this vision is the ability to first obtain a deep understanding of the underlying behavior and process dynamics that predict successful performance in early-stage concept generation. The objective of this research is to better understand the predictive factors that lead to improved performance during concept generation. In particular, this work focuses on the impact of idea fluency and timing of early-stage design concepts and their effect on overall measures of ideation session success. To accomplish this, we leverage an existing large-scale dataset containing hundreds of early-stage design concepts; each concept contains detailed ratings regarding its overall feasibility, usefulness, and novelty, as well as when in the ideation session the idea was recorded. Surprisingly, results indicate that there is no effect of idea fluency or timing on the quality of the output when using a holistic evaluation mechanism, such as the innovation measure, instead of a single measure such as novelty. Thus, exceptional concepts can be achieved by all participant segments independent of idea fluency. Furthermore, in early-stage concept generation sessions, highest-rated concepts have an equal probability of occurring early and late in a session. Taken together, these findings can be used to improve performance in ideation by effectively determining when and which types of design interventions future design tools might suggest.
Which Specific Angle Measurement Criteria Should be Used to Define Forward Head and Rounded Shoulder Posture: An Evidence-Based Commentary
Authors: Sandrey Michelle A.
Published: July 2021

Abstract: Postural distortions in the upper limb are prevalent and change the anatomical alignment, which alters force couples and the biomechanics of the body. Forward head posture (FHP) and rounded shoulder posture (RSP) are the two that are most prevalent. Measurement techniques using the craniovertebral angle for FHP and forward shoulder angle for RSP have been used both clinically and in the literature. However, what is not known is what specific criteria can be consistently used to define FHP and RSP as reference angles lack vigorous validity and there is a shortage of quantity, quality, and consistency of the evidence. Thus, there is much to be learned about postural classifications and the effect on the kinetic chain, supporting the need for further research in this area. As it is important to classify those who may need exercise and therapeutic intervention, following evidence-informed practice to inform decision-making clinicians should continue to evaluate posture, as well as examine scapular kinematics and muscle activity and the effects of interventions to improve posture. Therefore, determining whether FHP and RSP are present is paramount for the treatment to be successful.
Five-Minute Power-Based Test to Predict Maximal Oxygen Consumption in Road Cycling
Authors: Sitko Sebastian , Cirer-Sastre Rafel , Corbi Francisco , López-Laval Isaac
Published: July 2021

Purpose: To examine the ability of a multivariate model to predict maximal oxygen consumption (VO2max) using performance data from a 5-minute maximal test (5MT). Methods: Forty-six road cyclists (age 38 [9] y, height 177 [9] cm, weight 71.4 [8.6] kg, VO2max 61.13 [9.05] mL/kg/min) completed a graded exercise test to assess VO2max and power output. After a 72-hour rest, they performed a test that included a 5-minute maximal bout. Performance variables in each test were modeled in 2 independent equations, using Bayesian general linear regressions to predict VO2max. Stepwise selection was then used to identify the minimal subset of parameters with the best predictive power for each model. Results: Five-minute relative power output was the best explanatory variable to predict VO2max in the model from the graded exercise test (R2 95% credibility interval, .81–.88) and when using data from the 5MT (R2 95% credibility interval, .61–.77). Accordingly, VO2max could be predicted with a 5MT using the equation VO2max = 16.6 + (8.87 × 5-min relative power output). Conclusions: Road cycling VO2max can be predicted in cyclists through a single-variable equation that includes relative power obtained during a 5MT. Coaches, cyclists, and scientists may benefit from the reduction of laboratory assessments performed on athletes due to this finding.
High SARS-CoV-2 infection rate after resuming professional football in São Paulo, Brazil
Authors: Gualano Bruno , Brito Gisele Mendes , Pinto Ana Jéssica , Lemes Italo Ribeiro , Matos Luciana Diniz Nagem Janot , de Sá Pinto Ana Lúcia , Loturco Irineu
Published: July 2021

Objective

To examine the SARS-CoV-2 infection rate in a cohort of 6500 professional athletes and staff during the 2020 football (soccer) season in São Paulo, Brazil.

Methods

This retrospective cohort study included 4269 players (87% male, age: 21.7±4.2 years) and 2231 staff (87% male, age: 42.6±11.9 years) from 122 teams (women: n=16) involved in eight leagues (women: n=2), which took place in São Paulo, Brazil. Between 4 July 2020 and 21 December 2020, swab samples were collected weekly (n=29 507) and tested for SARS-Cov-2 via reverse transcription-PCR by an accredited laboratory commissioned by the São Paulo Football Federation. We contacted the medical staff of each team with positive cases to collect information on disease severity.

Results

Among 662 PCR-confirmed cases, 501 were athletes and 161 were staff. The new infection rate was 11.7% and 7.2% for athletes and staff, respectively. Athletes were more susceptible to infection than staff (OR: 1.71, 95% CI: 1.42, 2.06, p<0.001), although with lower chance for moderate to severe disease (OR: 0.06, 95% CI: 0.01, 0.54, p=0.012). Six teams had ≥20 individuals testing positive for SARS-CoV-2, whereas 19 teams had ≥10 confirmed cases. Twenty-five mass outbreaks were identified (≥5 infections within a team in a 2-week period). The prevalence of SARS-CoV-2 infections was similar in athletes and staff as the general population in São Paulo.

Conclusion

Despite weekly testing and other preventive measures, we found a high SARS-CoV-2 infection rate in athletes and staff after resuming football, which coincides with the high prevalence of infection in the community during the same period. These data may assist policy-makers and sports federations for determining if and when it is safe to resume competitions.
Proton pump inhibitors and risk of gastric cancer: population-based cohort study
Authors: Abrahami Devin , McDonald Emily Gibson , Schnitzer Mireille E , Barkun Alan N , Suissa Samy , Azoulay Laurent
Published: July 2021

Objective

To determine whether new users of proton pump inhibitors (PPIs) are at an increased risk of gastric cancer compared with new users of histamine-2 receptor antagonists (H2RAs).

Design

Using the UK Clinical Practice Research Datalink, we conducted a population-based cohort study using a new-user active comparator design. From 1 January 1990 to 30 April 2018, we identified 973 281 new users of PPIs and 193 306 new users of H2RAs. Cox proportional hazards models were fit to estimate HRs and 95% CIs of gastric cancer, and the number needed to harm was estimated using the Kaplan-Meier method. The models were weighted using standardised mortality ratio weights using calendar time-specific propensity scores. Secondary analyses assessed duration and dose–response associations.

Results

After a median follow-up of 5.0 years, the use of PPIs was associated with a 45% increased risk of gastric cancer compared with the use of H2RAs (HR 1.45, 95% CI 1.06 to 1.98). The number needed to harm was 2121 and 1191 for five and 10 years after treatment initiation, respectively. The HRs increased with cumulative duration, cumulative omeprazole equivalents and time since treatment initiation. The results were consistent across several sensitivity analyses.

Conclusion

The findings of this large population-based cohort study indicate that the use of PPIs is associated with an increased risk of gastric cancer compared with the use of H2RAs, although the absolute risk remains low.
Biomarker-based score for predicting in-hospital mortality of children admitted to the intensive care unit
Authors: Zhang Yin , Shi Qingxia , Zhong Guochao , Lei Xun , Lin Jilei , Fu Zhou , Dai Jihong
Published: July 2021

This study aims to establish a new scoring system based on biomarkers for predicting in-hospital mortality of children admitted to the pediatric intensive care unit (PICU). The biomarkers were chosen using the least absolute shrinkage and selection operator (LASSO)-logistic regression in this observational case-control study. The performance of the new predictive model was evaluated by the area under the receiver operating characteristic curve (AUC). Calibration plot was established to validate the new score accompanied by the Hosmer-Lemeshow test. There were 8818 patients included in this study. Finally, six predictors were included in the LASSO-regression model. Albumin <40 g/L, lactate dehydrogenase >452 U/L, lactate >3.2 mmol/L, urea >5.6 mmol/L, arterial PH <7.3 and glucose >6.9 mmol/L were treated as risk factors for higher mortality. The new score ranged from 1 to 6 among all the included patients. In the training set, the AUC of the probability of in-hospital mortality for the new predictive model was 0.81 (95% CI 0.79 to 0.84), which is larger than for the Pediatric Critical Illness Score (PCIS) (0.69, 95% CI 0.66 to 0.72). Similarly, in the validating set, the AUC of the probability of in-hospital mortality was larger for the new score (0.80, 95% CI 0.77 to 0.84) than for PCIS (0.67, 95% CI 0.63 to 0.72). The calibration plot and Hosmer-Lemeshow test showed excellent calibration. The calculated ORs showed a trend that higher scores indicated higher risk of death (p value for trend <0.001). In summary, this study develops and validates a totally biomarker-based new score to predict in-hospital mortality for pediatric patients admitted to PICU. More attention and more positive care and treatment should be given to children with a higher score.
Clinical phenotypes and outcomes of SARS-CoV-2, influenza, RSV and seven other respiratory viruses: a retrospective study using complete hospital data
Authors: Hedberg Pontus , Karlsson Valik John , van der Werff Suzanne , Tanushi Hideyuki , Requena Mendez Ana , Granath Fredrik , Bell Max , Mårtensson Johan , Dyrdak Robert , Hertting Olof , Färnert Anna , Ternhag Anders , Naucler Pontus
Published: July 2021

Background

An understanding of differences in clinical phenotypes and outcomes COVID-19 compared with other respiratory viral infections is important to optimise the management of patients and plan healthcare. Herein we sought to investigate such differences in patients positive for SARS-CoV-2 compared with influenza, respiratory syncytial virus (RSV) and other respiratory viruses.

Methods

We performed a retrospective cohort study of hospitalised adults and children (≤15 years) who tested positive for SARS-CoV-2, influenza virus A/B, RSV, rhinovirus, enterovirus, parainfluenza viruses, metapneumovirus, seasonal coronaviruses, adenovirus or bocavirus in a respiratory sample at admission between 2011 and 2020.

Results

A total of 6321 adult (1721 SARS-CoV-2) and 6379 paediatric (101 SARS-CoV-2) healthcare episodes were included in the study. In adults, SARS-CoV-2 positivity was independently associated with younger age, male sex, overweight/obesity, diabetes and hypertension, tachypnoea as well as better haemodynamic measurements, white cell count, platelet count and creatinine values. Furthermore, SARS-CoV-2 was associated with higher 30-day mortality as compared with influenza (adjusted HR (aHR) 4.43, 95% CI 3.51 to 5.59), RSV (aHR 3.81, 95% CI 2.72 to 5.34) and other respiratory viruses (aHR 3.46, 95% CI 2.61 to 4.60), as well as higher 90-day mortality, ICU admission, ICU mortality and pulmonary embolism in adults. In children, patients with SARS-CoV-2 were older and had lower prevalence of chronic cardiac and respiratory diseases compared with other viruses.

Conclusions

SARS-CoV-2 is associated with more severe outcomes compared with other respiratory viruses, and although associated with specific patient and clinical characteristics at admission, a substantial overlap precludes discrimination based on these characteristics.
Awareness, perceptions of and compliance with tobacco control policies among naswar vendors in Khyber Pakhtunkhwa Pakistan
Authors: Ahmad Fayaz , Khan Zohaib , Siddiqi Kamran , Khan Muhammad Naseem , Kibria Zeeshan , Forberger Sarah , Bauld Linda , Kanaan Mona , Zeeb Hajo
Published: July 2021

Introduction

Regulatory compliance in the retail environment is integral to the success of tobacco control. We assessed compliance among naswar (smokeless tobacco product widely used in South Asia) vendors with tobacco control laws. We also assessed their awareness of tobacco-related harms and policies and perceived effect of policies on their sales.

Methods

We surveyed 286 naswar vendors in three districts of the Khyber Pakhtunkhwa province of Pakistan. We recruited general and specialty vendors from urban and rural areas through multistage cluster sampling. Compliance was measured for promotion, sale to/by minors and tax paid on naswar. We used logistic regression analyses for assessing the association between the outcome variables (awareness of tobacco harms and laws, perceptions about the effect of policies on business and compliance with laws) and their predictors.

Results

Most vendors (70%) were aware of tobacco-related harms of naswar. Although educated vendors were more aware of tobacco control policies, the greatest awareness was for a ban on sales to/by minors (21% overall). The majority of vendors (76%) violated this policy (measured by self-report), and violations were more common among rural than urban vendors (OR 2.27, 95% CI 1.05 to 4.96). Most vendors (71%) violated a ban on promotion of naswar. Vendors perceived tax increases and sales ban to/by minors as most detrimental for business.

Conclusions

There was poor awareness and compliance among naswar vendors in Pakistan with tobacco control laws. This study finds potential areas for policy interventions that can reduce urban/rural disparities in implementation of and compliance with tobacco control laws.
Exploring the gateway hypothesis of e-cigarettes and tobacco: a prospective replication study among adolescents in the Netherlands and Flanders
Authors: Martinelli Thomas , Candel Math J J M , de Vries Hein , Talhout Reinskje , Knapen Vera , van Schayck Constant P , Nagelhout Gera E
Published: July 2021

Background

Studies demonstrated that adolescent e-cigarette use is associated with subsequent tobacco smoking, commonly referred to as thegateway effect. However, most studies only investigated gateways from e-cigarettes to tobacco smoking. This study replicates a cornerstone study revealing a positive association between both adolescent e-cigarette use and subsequent tobacco use; and tobacco and subsequent e-cigarette use in the Netherlands and Flanders.

Design

The longitudinal design included baseline (n=2839) and 6-month (n=1276) and 12-month (n=1025) follow-up surveys among a school-based cohort (mean age: 13.62). Ten high schools were recruited as a convenience sample. The analyses involved (1) associations of baseline e-cigarette use and subsequent tobacco smoking among never smokers; (2) associations of e-cigarette use frequency at baseline and tobacco smoking frequency at follow-up; and (3) the association of baseline tobacco smoking and subsequent e-cigarette use among non-users of e-cigarettes.

Findings

Consistent with prior findings, baseline e-cigarette use was associated with higher odds of tobacco smoking at 6-month (OR=1.89; 95% CI 1.05 to 3.37) and 12-month (OR=5.63; 95% CI 3.04 to 10.42) follow-ups. More frequent use of e-cigarettes at baseline was associated with more frequent smoking at follow-ups. Baseline tobacco smoking was associated with subsequent e-cigarette use (OR=3.10; 95% CI 1.58 to 6.06 at both follow-ups).

Conclusion

Our study replicated the positive relation between e-cigarette use and tobacco smoking in both directions for adolescents. This may mean that the gateway works in two directions, that e-cigarette and tobacco use share common risk factors, or that both mechanisms apply.
On the existence of the global conformal gauge in string theory
Authors: Katanaev M. O.
Published: July 2021

The global conformal gauge is playing the crucial role in string theory providing the basis for quantization. Its existence for two-dimensional Lorentzian metric is known locally for a long time. We prove that if a Lorentzian metric is given on a plain then the conformal gauge exists globally on the whole $${{\mathbb {R}}}^2$$

R

2

. Moreover, we prove the existence of the conformal gauge globally on the whole worldsheets represented by infinite strips with straight boundaries for open and closed bosonic strings. The global existence of the conformal gauge on the whole plane is also proved for the positive definite Riemannian metric.
Robustness of a dynamical systems model with a plastic self-organising vector field to noisy input signals
Authors: Janson N. B. , Kloeden P. E.
Published: July 2021

We investigate the robustness with respect to random stimuli of a dynamical system with a plastic self-organising vector field, previously proposed as a conceptual model of a cognitive system and inspired by the self-organised plasticity of the brain. This model of a novel type consists of an ordinary differential equation subjected to the time-dependent “sensory” input, whose time-evolving solution is the vector field of another ordinary differential equation governing the observed behaviour of the system, which in the brain would be neural firings. It is shown that the individual solutions of both these differential equations depend continuously over finite time intervals on the input signals. In addition, under suitable uniformity assumptions, it is shown that the non-autonomous pullback attractor and forward omega limit set of the given two-tier system depend upper semi-continuously on the input signal. The analysis holds for both deterministic and noisy input signals, in the latter case in a pathwise sense.
Fields of locally compact quantum groups: Continuity and pushouts
Authors: Chirvasitu Alexandru
Published: July 2021

We prove that discrete compact quantum groups (or more generally locally compact, under additional hypotheses) with coamenable dual are continuous fields over their central closed quantum subgroups, and the same holds for free products of discrete quantum groups with coamenable dual amalgamated over a common central subgroup. Along the way we also show that free products of continuous fields of [Formula: see text]-algebras are again free via a Fell-topology characterization for [Formula: see text]-field continuity, recovering a result of Blanchard’s in a somewhat more general setting.
Calculation of the Top-Quark Yukawa coupling constant
Authors: Sadeghi Alavijeh P. , Tazimi N. , Monemzadeh M.
Published: July 2021

In this work, we study meson systems consisting of quark–antiquark. We solve Lippman–Schwinger equation numerically for heavy meson systems. We attempt to find a nonrelativistic potential model through which we can solve the quark–antiquark bound state problem. The coefficients obtained are in agreement with Martin potential coefficients. Via this method we also determine the strong coupling constant of Cornell and Yukawa potentials for the heavy meson.
The Higgs potential in 2HDM extended with a real triplet scalar: A roadmap
Authors: Ait-Ouazghour B. , Chabab M.
Published: July 2021

We perform a comprehensive study of the Higgs potential of the two Higgs doublet model extended by a real triplet scalar field [Formula: see text]. This model, dubbed [Formula: see text], has a rich Higgs spectrum consisting of three CP-even Higgs [Formula: see text], one CP-odd [Formula: see text] and two pairs of charged Higgs [Formula: see text]. First, we determine the perturbative unitarity constraints and a set of nontrivial conditions for the boundedness from below (BFB). Then we derive the Veltman conditions by considering the quadratic divergencies of Higgs boson self-energies in [Formula: see text]. We find that the parameter space is severely delimited by these theoretical constraints, as well as experimental exclusion limits and Higgs signal rate measurements at LEP and LHC. Using HiggsBounds-5.3.2beta and HiggSignals-2.2.3beta public codes, an exclusion test at [Formula: see text] is then performed on the physical scalars of [Formula: see text]. Our analysis provides a clear insight on the nonstandard scalar masses, showing that the allowed ranges are strongly sensitive to the sign of mixing angle [Formula: see text], essentially when naturalness is involved. For [Formula: see text] scenario, our results place higher limits on the bounds of all scalar masses, and show that the pairs [Formula: see text] and [Formula: see text] are nearly mass degenerate varying within the intervals [Formula: see text] GeV and [Formula: see text] GeV, respectively. When [Formula: see text] turns positive, we show that consistency with theoretical constraints and current LHC data, essentially on the diphoton decay channel, favors Higgs masses varying within wide allowed ranges: [Formula: see text] GeV for [Formula: see text]; [Formula: see text] GeV for ([Formula: see text], [Formula: see text]) and [Formula: see text] GeV for ([Formula: see text], [Formula: see text]). Finally, we find that the [Formula: see text] and [Formula: see text] Higgs decay modes are generally correlated if [Formula: see text] lies within the reduced intervals [Formula: see text] and [Formula: see text] parameter is frozen around [Formula: see text] ([Formula: see text]) for [Formula: see text] ([Formula: see text]).
Currents of created pairs in strong electric fields
Authors: Akhmedov E. T. , Anokhin A. V. , Sadekov D. I.
Published: July 2021

In this paper, we calculate tree-level currents of created particles in strong background electric fields in 4D QED for various initial states. Namely, we do that in pulse background for initial vacuum and thermal states at past infinity. In both cases, we find that the current grows linearly with the length of the pulse with coefficients of proportionality containing the characteristic Schwinger’s factor. For the constant electric field background, we calculate the current for several different initial states. We observe that in such a case the current is either zero or linearly divergent. We explain the reason for such a behavior and compare the situation in ordinary and scalar QED. Finally, we calculate the current in two-dimensional situation in the presence of such settings when the so-called Klein paradox can be observed.
Bc → J/ψ tensor form factors at large momentum recoil
Authors: Shen Dandan , Ren Huimin , Wu Fan , Zhu Ruilin
Published: July 2021

We present a next-to-leading order (NLO) relativistic correction to [Formula: see text] tensor form factors within nonrelativistic QCD (NRQCD). We also consider complete Dirac bilinears [Formula: see text] with [Formula: see text] matrices [Formula: see text] in the [Formula: see text] transition. The relation among different current form factors is given and it shows that symmetries emerge in the heavy bottom quark limit. For a phenomenological extension, we propose to extract the long-distance matrix elements (LDMEs) for [Formula: see text] meson from the recent HPQCD lattice data and the NLO form factors at large momentum recoil.
Dynamics of a composite system in a point source-induced space–time
Authors: Guvendi Abdullah
Published: July 2021

We investigate the dynamics of a composite system ([Formula: see text]) consisting of an interacting fermion–antifermion pair in the three-dimensional space–time background generated by a static point source. By considering the interaction between the particles as Dirac oscillator coupling, we analyze the effects of space–time topology on the energy of such a [Formula: see text]. To achieve this, we solve the corresponding form of a two-body Dirac equation (fully-covariant) by assuming the center-of-mass of the particles is at rest and locates at the origin of the spatial geometry. Under this assumption, we arrive at a nonperturbative energy spectrum for the system in question. This spectrum includes spin coupling and depends on the angular deficit parameter [Formula: see text] of the geometric background. This provides a suitable basis to determine the effects of the geometric background on the energy of the [Formula: see text] under consideration. Our results show that such a [Formula: see text] behaves like a single quantum oscillator. Then, we analyze the alterations in the energy levels and discuss the limits of the obtained results. We show that the effects of the geometric background on each energy level are not same and there can be degeneracy in the energy levels for small values of the [Formula: see text].
From uneventful Horizon to firewall in D-dimensional effective theory
Authors: Ho Pei-Ming
Published: July 2021

Assuming the standard effective-field-theoretic formulation of Hawking radiation, we show explicitly how a generic effective theory predicts a firewall from an initially uneventful horizon for a spherically symmetric, uncharged black hole in [Formula: see text] dimensions for [Formula: see text]. The firewall is created via higher-derivative interactions within the scrambling time after the collapsing matter enters the trapping horizon. This result manifests the trans-Planckian problem of Hawking radiation and demonstrates the incompatibility between Hawking radiation and the uneventful horizon.
Fuzzy resilient control for synchronizing chaotic systems with time-variant delay and external disturbance
Authors: Tai Weipeng , Zuo Dandan , Han Jing , Zhou Jianping
Published: July 2021

This paper focuses on the issue of fuzzy resilient control for synchronizing chaotic systems with time-variant delay and external disturbance. The goal is to design a fuzzy resilient controller with additive gain perturbations to guarantee that not only the drive and response systems are asymptotically synchronized in the absence of external disturbance, but also the synchronization error system has a prescribed disturbance attenuation index under the zero initial condition. By utilizing an appropriate Lyapunov–Krasovskii functional, the Bessel–Legendre inequality, and the reciprocally convex combination technique, a criterion on the stability and [Formula: see text] performance of the synchronization error system is derived. Then, by means of some decoupling methods, a design scheme of the fuzzy resilient controller is developed. Finally, one numerical example is provided to examine the effectiveness of the fuzzy resilient controller design scheme.
Contagion dynamics in multilayer networks with community structure
Authors: Zhang Yun , Yang Jin-Xuan
Published: July 2021

The study of contagion dynamics in multilayer networks has become a hot topic. Networks have the characteristics of community structure. In this work, we present a comprehensive epidemic spreading model in multilayer networks with community structure. We consider the effects of population mobility, natural mortality and natural birth rate on population dynamics and contagion dynamics. The population size is determined by natural mortality and natural birth rate. The global and local epidemic thresholds are obtained. We analyze the factors which affect epidemic thresholds. The population mobility has no effect on the global epidemic threshold, but it can affect epidemic thresholds of each community. To control outbreaks of epidemics in influential communities can well control the spreading of diseases in the whole system. It is conductive to controlling outbreak of epidemics by reducing the internal average degree and interconnected links in influential communities. Numerical simulations on synthetic networks further support and enrich our conclusions.
A Linear High Frequency gm Boosting Wideband LNA in 130 nm SiGe HBT with Minimum NF of 4.3 dB for WiGig Application
Authors: Sukumaran Pournamy , Kumar Navin , Ponnambalam Maran
Published: July 2021

This paper presents an inductor less wideband low noise amplifier (LNA) with an area of 0.3[Formula: see text]mm2, using 130[Formula: see text]nm SiGe BiCMOS technology targeted for 5G WiGig wireless application. A [Formula: see text] boosting amplifier used at the intermediate node of the cascode topology to reduce the noise contribution of the common base (CB) transistor for the first time in SiGe HBT technology. Mathematical analysis shows that the proposed high frequency [Formula: see text] boosting technique on the CB transistor can be optimally tuned for either low NF or high linearity. Furthermore, the circuit incorporates variable capacitors for multimode capability, ensuring optimal performance in all four WiGig channels. Post layout EM simulation of the circuit shows that the resultant LNA has a maximum gain of 21.08[Formula: see text]dB with the [Formula: see text]3 dB frequency over 56[Formula: see text]GHz to 67.3[Formula: see text]GHz. The proposed LNA exhibits a minimum noise figure of 4.3[Formula: see text]dB and shows high linearity with an input referred [Formula: see text] of [Formula: see text]2.7[Formula: see text]dB. The designed when operated using supply voltage of 1.2[Formula: see text]V consumes a total dc power of 8.9[Formula: see text]mW.
MULTI-RESPONSE OPTIMIZATION OF END-MILLING PARAMETERS FOR INCONEL 625 USING TAGUCHI COUPLED WITH TOPSIS
Authors: THANGAMUTHU MOHANRAJ , YERCHURU JAYANTHI , SHANMUGAM NITHIN ARAVIND RAMASAMY , RAVI YAMENI , GUR ALI KAYA
Published: July 2021

Using Taguchi design of experiments (DoE), experiments were conducted with 3 factors and 3 levels. The factors were the depth of cut, spindle speed, and feed. The responses were surface roughness, flank wear, material removal rate, and spindle vibration along [Formula: see text] ([Formula: see text]), [Formula: see text] ([Formula: see text]), and [Formula: see text] ([Formula: see text]) axis. To convert the multi-response optimization problem into a single response optimization problem, the technique for order of preference by similarity to ideal solution (TOPSIS) was applied. The S/N of the closeness coefficients from TOPSIS was calculated and optimum machining conditions were obtained. Further, analysis of variance (ANOVA) was performed to verify which input parameter significantly affects the output responses. From TOPSIS optimization, the responses like surface roughness and flank wear were decreased by 0.99% and 2.55%. The vibration in [Formula: see text], [Formula: see text], and [Formula: see text]-axis decreased by 3.84%, 16.87% and 12.48% respectively. This optimization significantly enhances the machining characteristics.
CNN-based Prediction of COVID-19 using Chest CT Images
Authors: Arora Tanvi
Published: July 2021

The coronavirus disease (COVID-19) pandemic that is caused by the SARS-CoV2 has spread all over the world. It is an infectious disease that can spread from person to person. The severity of the disease can be categorized into five categories namely asymptomatic, mild, moderate, severe, and critical. From the reported cases thus, it has been seen that 80% of the cases that test positive with COVID-19 infection have less than moderate complications, whereas 20% of the positive cases develop severe and critical complications. The virus infects the lungs of an individual, therefore, it has been observed that the X-ray and computed tomography (CT) scan images of the infected people can be used by the machine learning-based application programs to predict the presence of the infection. Therefore, in the proposed work, a Convolutional Neural Network model based upon the DenseNet architecture is being used to predict the presence of COVID-19 infection using the CT scan images of the chest. The proposed work has been carried out using the dataset of the CT images from the COVID CT Dataset. It has 349 images marked as COVID-19 positive and 397 images have been marked as COVID-19 negative. The proposed system can categorize the test set images with an accuracy of 91.4%. The proposed method is capable of detecting the presence of COVID-19 infection with good accuracy using the chest CT scan images of the humans.
BBO-Based State Optimization for PMSM Machines
Authors: Lakehal Hanane , Ghanai Mouna , Chafaa Kheireddine
Published: July 2021

In this investigation, state vector estimation of the Permanent Magnet Synchronous machine (PMSM) using the nonlinear Kalman estimator (Extended Kalman Filter) is considered. The considered states are the speed of the rotor, its angular position, the torque of the load and the resistance of the stator. Since the extended Kalman filter contains some free parameters, it will be necessary to optimize them in order to obtain a better efficiency. The free parameters of EKF are the covariance matrices of state noise and measurement noise. These later will be auto adjusted by a new metaheuristic optimization technique called Biogeographical-based optimization (BBO). As far as we know, BBO–EKF optimization for PMSM state was not treated in the literature. The suggested estimation tuning approach is demonstrated using a computer simulation of a PMSM. Simulated experimentations show the robustness and effectiveness of the proposed scheme. In addition, a detailed comparative study with conventional methods like Particle Swarm Optimization and Genetic Algorithms will be given.
Expert Consensus on Disaster Medical Rescue Services
Authors: Long Yan , Zhai Jing , Du Jiang
Published: July 2021

Disasters and disaster rescue are accompanied by the development of human history. But disaster medicine has been a discipline only for several decades recently. The establishment of the disaster rescue system in China began with the outbreak of SARS in 2003. As the incident exposed a series of problems in response to emerging infectious diseases, China began to consider how to systematically respond to various disasters and commence establishing a comprehensive emergency management system. The “Emergency Response Law of the People’s Republic of China” implemented in 2007 marks the preliminary establishment of China’s modern disaster rescue system. In December 2011, the Disaster Medicine Branch of Chinese Medical Association was established in Shanghai, marking a new stage of the development of disaster medicine in China. Here, disaster medicine and medical rescue services were summarized to guide the implementation of related work.
Single and Binary Adsorption Systems of Rhodamine B and Methylene Blue onto Alkali-Activated Vietnamese Diatomite
Authors: Du Pham Dinh , Danh Huynh Thanh
Published: July 2021

Diatomite was slightly modified with a sodium hydroxide solution. The resulting material was characterized by using energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and nitrogen adsorption-desorption isotherms. The so-treated diatomite has a high specific surface area (77.8 m2/g) and a high concentration of isolated silanol groups on the surface, and therefore, its adsorption capacity increases drastically in both the single and binary adsorption systems for rhodamine B and methylene blue. The binary system is more effective than the single system, with methylene blue being adsorbed more than rhodamine B. The adsorption process is spontaneous and fits well with the Langmuir isothermal model, and it depends on pH significantly.
UAV Task Allocation Based on Clone Selection Algorithm
Authors: Zhang Xiaopan , Chen Xingjun
Published: July 2021

With the continuous development of computer and network technology, the large‐scale and clustered operations of drones have gradually become a reality. How to realize the reasonable allocation of UAV cluster combat tasks and realize the intelligent optimization control of UAV cluster is one of the most challenging difficulties in UAV cluster combat. Solving the task allocation problem and finding the optimal solution have been proven to be an NP‐hard problem. This paper proposes a CSA‐based approach to simultaneously optimize four objectives in multi‐UAV task allocation, i.e., maximizing the number of successfully allocated tasks, maximizing the benefits of executing tasks, minimizing resource costs, and minimizing time costs. Experimental results show that, compared with the genetic algorithm, the proposed method has better performance on solving the UAV task allocation problem with multiple objectives.
Microbial Biosensors as Pesticide Detector: An Overview
Authors: Aynalem Birhan , Muleta Diriba
Published: July 2021

Farmers are highly dependent upon agrochemicals to boost crop production through soil fertilization and and insect pests, pathogens, parasites, and weeds management . However, contentious application of agrochemicals on the farm has aggravated residual accumulation and has become problematic for environmental safety besides causing disease to humans and other animals. Thus, the analysis of chemical residues from the environment is vital for policymakers and communities. Mostly, chemists were devoted to analyzing the existing contaminants from different sources by using highly sophisticated chromatographic equipment, although it is time taking, laborious, costly, and that required well‐trained professionals. However, biosensors are more important to analyze chemical contaminants from different samples using various bioreporters integrated with electrochemical and optical transducers. Microbes are metabolically diverse, amenable for genetic engineering, cost effective in culturing, and tolerant to diverse conditions. Thus, microbial biosensor is capturing attention and becoming more effective for environmental monitoring. Therefore, this review assessed the implication of microbial biosensors for pesticide detection and the role of genetic engineering for strain improvement.
Computational and Preclinical Evidence of Anti‐ischemic Properties of L‐Carnitine‐Rich Supplement via Stimulation of Anti‐inflammatory and Antioxidant Events in Testicular Torsed Rats
Authors: Olugbodi Janet Olayemi , Samaila Keren , Lawal Bashir , Anunobi Oluchukwu Ogechukwu , Baty Roua S. , Ilesanmi Omotayo Babatunde , Batiha Gaber El-Saber
Published: July 2021

Ischemia‐reperfusion injury is a urological emergency condition that could lead to necrosis, testicular damage subfertility, and infertility. The purpose of this study was to identify changes taking place in the rat testis at short‐term (4 hr) as well as long‐term (7 days) reperfusion following testicular torsion and to evaluate the effects of Proxeed Plus (PP), L‐carnitine‐rich antioxidant supplement, on preventing these changes using the biochemical parameters and histopathology. Thirty adult male rats were divided into five groups: in groups, 1‐4 testicular ischemia was achieved by rotating the left testis 720° clockwise for 4 h and dividing into the sham, torsion/detorsion (T/D), T/D+1000 mg/kg BW PP, and T/D+5000 mg/kg BW PP groups, respectively. PP was administered intraperitoneally 30 min before detorsion while group 5 served as the normal control. All rats were sacrificed 4 h after detorsion. The same experimental design was set up, and animals were sacrificed after 7 days of detorsion. The testicular levels of human cyclooxygenase‐2; tumor necrosis factor; interleukins‐1β, 6, and 10; hydrogen peroxide; malonaldehyde; superoxide dismutase; catalase; glutathione transferase; glutathione peroxidase; glutathione reductase; and histopathological damage were evaluated. Our results revealed that rats in the torsion/detorsion group exhibited elevated testicular levels of oxidative markers and proinflammatory cytokines, low levels of antioxidant enzymes, and severe histological alterations relative to the control and sham groups. Treatments with 1000 and 5000 mg/kg BW of PP for 4 hr and 7 days significantly (p < 0.05) decreased the levels of the proinflammatory and oxidative markers while increasing the spermatogenesis, testicular levels of antioxidant enzymes, and anti‐inflammatory cytokine (IL‐10) in a dose‐dependent manner. This suggested that PP exhibited anti‐inflammatory and antioxidant activities against I/R testes thus serving as an effective supplement to protect against testicular assault.
A Review on Antidiabetic Activity of Centaurea spp.: A New Approach for Developing Herbal Remedies
Authors: Fattaheian-Dehkordi Samaneh , Hojjatifard Reza , Saeedi Mina , Khanavi Mahnaz
Published: July 2021

Objective. Diabetes mellitus (DM) is a long-life metabolic disorder, characterized by high blood glucose levels. The hyperglycemic condition generally leads to irreversible nerve injury and vascular damage. Among different types of diabetes, type 2 is more common and has spread all over the world. Although various therapeutic approaches have been developed to control type 2 DM, regulating blood glucose levels has still remained a controversial challenge for patients. Also, most prescription drugs cause different side effects, such as gastrointestinal disorders. Thus, developing novel and efficient antidiabetic agents possessing fewer adverse effects is in high demand. Method. The literature was comprehensively surveyed via search engines such as Google Scholar, PubMed, and Scopus using appropriate keywords. Results. Medicinal plants, both extracts and isolated active components, have played a significant role in controlling the blood glucose levels. Good-to-excellent results documented in the literature have made them a precious origin for developing and designing drugs and supplements against DM. Centaurea spp. have been traditionally used for controlling high blood glucose levels. Also, the antidiabetic properties of different species of Centaurea have been confirmed in recent studies through in vitro assays as well as in vivo experiments. Conclusion. Potent results encouraged us to review their efficacy to open a new horizon for development of herbal antidiabetic agents.