bluuebunny/crossref_metadata_2025_split huggingface dataset:
On a tangential‐conforming finite element formulation for the relaxed micromorphic model in 2D
Authors: Sarhil Mohammad , Scheunemann Lisa , Neff Patrizio , Schröder Jörg 
Published: December 2021

AbstractThe relaxed micromorphic model is a generalized continuum model that reduces the complexity of the general micromorphic theory [1] and shows many advantages such as the bounded stiffness for small sizes [2–4]. It keeps the full kinematics of the micromorphic theory but employs the matrix Curl operator of a second‐order micro‐distortion field for the curvature measurement. The solution of the micro‐distortion exists in H(curl) while the displacement is still in H1. In this work, we introduce an H1 × H(curl) finite element formulation of the relaxed micromorphic model. The presented mixed formulation satisfies the tangential continuity of the micro‐distortion field on the element boundaries. We compare the convergence behavior of the mixed formulation with the classical H1 × H1 finite element formulation using numerical examples. Finally, we show the model's main characteristics and the scale‐dependency of the model's components where the relaxed micromorphic model gives the different Cauchy elastic limit cases with determined elasticity tensors.
Semi‐automated Data‐driven FE Mesh Generation and Inverse Parameter Identification for a Multiscale and Multiphase Model of Function‐Perfusion Processes in the Liver
Authors: Lambers Lena , Mielke André , Ricken Tim 
Published: December 2021

AbstractBiomechanical modeling enables a better understanding and prediction of various processes in the human body. To make this simulation more patient‐specific, realistic geometries of liver lobules are included in an existing knowledge‐based model for the simulation of hepatic function‐perfusion processes in the human liver. This model allows the simulation of liver diseases such as the non‐alcoholic fatty liver disease (NAFLD) or tumor development. The basis of this calculation is a continuum‐biomechanical multiscale and multiphase model based on the Theory of Porous Media. To capture the function‐perfusion and growth processes in the liver, partial differential equations (PDEs) on the lobule scale are coupled to ordinary differential equations (ODEs) describing metabolic processes on the cellular scale. Additionally, we used manifold learning techniques on in silico data for the identification of inverted fat zonation during NAFLD.
A comparative study of FE‐schemes for micromagnetic simulations
Authors: Reichel Maximilian , Xu Bai-Xiang , Schröder Jörg 
Published: December 2021

AbstractWith ongoing development of new technological devices, the demand for efficient magnetic materials and composites has significantly increased. Micromagnetic simulations can predict the magnetization distribution on sub micrometer scales. Due to performance purposes these simulations are often run on finite differences schemes. In contrast to the finite differences method, finite element based micromagnetic simulations posses high flexibility with geometry. One key aspect is the accurate discretization of geometrical structures, representing a big advantage in the analysis of complex microstructures. To describe the evolution of the magnetization vector the Landau‐Lifshitz‐Gilbert (LLG) equation is applied. A central point of the latter equation is the preservation of the Euclidean norm on the magnetization vector through the simulation. In this contribution first results of comparisons of different micromagnetic simulations are presented.
Work‐conjugacy of stress and strain tensors and its role in 3D hyperelastic isotropic material formulation
Authors: Dutzler Andreas , Guggenberger Werner 
Published: December 2021

AbstractIn accordance with the framework of hyperelastic isotropic material description it appears possible to replace work‐conjugate stress and strain quantities by alternative pairs of work‐conjugate stress and strain quantities while other things left unaltered, i.e. based on a retained architecture of the strain energy density function. This replacement results in formally representing different kinds of material response behavior. This may be recognized from the various comparable forms of resulting uniaxial force versus axial stretch behavior in the representative 3D principal axes system. Clarifying and achieving comprehensive understanding of these observations is the main purpose of this paper.
Numerical investigation of the Poisson's ratio of an amorphous bilayer 2D network material
Authors: Stratmann Jan , Bamer Franz , Kataria Satender , Lemme Max Christian , Markert Bernd 
Published: December 2021

AbstractThis paper investigates the transverse contraction of amorphous bilayer 2D Silica with varying network heterogeneities under uniaxial tensile loading using athermal molecular simulations in LAMMPS. It turns out that the transverse contraction increases nonlinearly with the x‐strain while it decreases with increasing network heterogeneity. We show that it is possible to engineer the heterogeneity of amorphous network materials, making them potential candidates for nano‐electromechanical applications.
On the inverse Cauchy problem for linear ordinary differential equations
Authors: Chartouny Maya , Cluzeau Thomas , Quadrat Alban 
Published: December 2021

AbstractThe Cauchy problem characterizes the solutions of a linear ordinary differential equation that satisfies initial conditions. In this paper, we investigate the converse problem, namely, given a function that is known to satisfy a linear ordinary differential equation of a fixed order, determine the coefficients of the ordinary differential equation and the initial conditions. The techniques used to investigate the inverse Cauchy problem come from the algebraic estimation problem introduced by Fliess and Sira‐Ramírez. From the perfect observation of the solution, i.e., without external perturbation and noise corrupting it, the initial value problem can be explicitly reconstructed using only iterative indefinite integrals of the solution.
Darcy's law for evolving microstructure
Authors: Wiedemann David , Peter Malte A. 
Published: December 2021

AbstractA Darcy law for evolving microstructure is derived by homogenisation of Stokes flow. We transform the Stokes equations from the locally evolving domain onto a periodic reference domain. There, we pass to the homogenisation limit by employing the method of two‐scale convergence. After transforming the limit back to its original two‐scale domain, we obtain a Darcy Law for evolving microstructure. This Darcy Law does not only capture the space‐ and time‐dependent permeability, but also includes how the change of the porosity induces pressure. In order to give uniform a priori estimates, we derive a Korn‐type inequality for this two‐scale transformation method as well as a family of ϵ‐scaled operators div−1ϵ.
Applicability of the lead field approach in virtual laboratory studies: comparison with full numerical simulations based on the bidomain model
Authors: Ogiermann Dennis , Perotti Luigi E. , Balzani Daniel 
Published: December 2021

AbstractThe lead field approach is likely the most widely adopted method to compute electrocardiograms (ECGs) from electrophysiology (EP) simulations. Since this approach introduces several simplifying assumptions, this raises the question of its applicability in laboratory scenarios. Laboratory experiments can be used to validate and calibrate EP models by utilizing, amongst other techniques, unipolar and/or bipolar pseudo‐ECG measurements, which therefore need to be computed accurately. In this work, we present a computational study within a previously proposed validation framework based on the Antzelevitch's laboratory model of transmural wedges. In order to investigate the applicability of the lead field approach in this scenario, the unipolar and bipolar measurements computed from bidomain simulations are compared with measurements obtained with the lead field approach. Our study suggests that unipolar measurements are not well captured by the lead field approach, while bipolar measurements obtained with the lead field approach exhibit reasonable qualitative agreement with measurements computed from full bidomain simulations.
Experiments, hyperelastic modeling and finite element simulation of 3D‐printed thermoplastic polyurethane
Authors: Landgraf Ralf , Oelsch Erik , Steiniger Vincent , Ihlemann Jörn 
Published: December 2021

AbstractA combined experimental and numerical investigation on the mechanical behavior of 3D‐printed thermoplastic polyurethane is presented. In particular, the behavior under monotonic loading until rupture is considered. For this purpose, tensile test specimens are analyzed, which were produced by conventional injection molding and by an extrusion‐based additive manufacturing process. The additively manufactured test specimens have notched surfaces that influence the failure behavior due to stress and strain concentrations. For the numerical analysis, a finite element modeling approach is presented with which the experiments are simulated. It is shown that the tensile curves can be simulated using a hyperelastic material model and that first indicators can be found that enable a prediction of failure under monotonic tensile loading.
FFT‐based homogenization using a reduced set of frequencies and a clustered microstructure
Authors: Waimann Johanna , Gierden Christian , Schmidt Annika , Svendsen Bob , Reese Stefanie 
Published: December 2021

AbstractTo capture the material behavior of composite microstructures, Moulinec and Suquet [5] proposed a homogenization scheme making use of fast Fourier transforms (FFT) and fixed‐point iterations. To reduce the computational effort of this spectral method, Kochmann et al. [3] introduced a model order reduction technique, which is based on using a fixed reduced set of frequencies for the computations in Fourier space. Within the current work, we improved the accuracy of the approach by use of a geometrically adapted set of frequencies, see [1]. Since the constitutive relations are still evaluated in real space, the technique is most beneficial for a linear material behavior. Considering nonlinear material behavior, most of the computing time is related to solving the constitutive relations. Therefore, the total speed‐up is lower. To achieve a further reduction of the computational effort for a nonlinear material behavior, the earlier proposed model order reduction technique is coupled with a clustering analysis [4]. The whole microstructure is thus divided into clusters, which show a similar material behavior. Within these clusters, the micromechanical fields are assumed to be constant which leads to a significant reduction of computational costs compared to the highly resolved solution.
On computing reduced‐order bilinear models from time‐domain data
Authors: Gosea Ion Victor , Karachalios Dimitrios S. , Antoulas Athanasios C. 
Published: December 2021

AbstractWe propose a procedure for identification of reduced‐order bilinear models from time‐domain data, i.e., sampled values of the control input and of the observed output. To accomplish this, we require two sets of data corresponding to the response of the system to two differently‐scaled step functions, as control inputs. Then, the Markov parameters for two time‐varying linear models are extracted, and from this information, we are able to infer a reduced‐order bilinear model.
Selected historical aspects of wave phenomena in the context of dynamical systems, and applications in seamless learning
Authors: Gunesch Roland 
Published: December 2021

AbstractThis article gives an overview of a few selected historical examples of the mathematical investigation of wave phenomena, ranging from one of the earliest cases of the systematic study of periodic oscillations to modern mathematical methods and various applications. Hooke's analysis of the mass‐spring problem, population dynamics with periodic behavior, and chemical oscillations are discussed. Many examples of real‐world wave phenomena from everyday life are also mentioned.I also explain a few aspects and ideas of the modern method of teaching the underlying science of wave dynamics to a general audience with the help of easily accessible computer‐based tools (an example of seamless learning).
Thin film nanocomposites from a novel poly(keto ether sulfone) to remove metal ions from wastewater
Authors: Mehdipour‐Ataei Shahram , Babanzadeh Samal , Khodami Samaneh 
Published: December 2021

AbstractAccording to the clean water crisis, purification of water resources is so imperative. Reverse osmosis is the best method for the purification of wastewater. In this article, a new diol and resulting poly(keto ether sulfone) was synthesized and characterized successively. Innovative nanocomposites were prepared with the novel poly(keto ether sulfone) and various nanomaterials including clay, graphene oxide, multi‐walled carbon nanotube, and sepiolite. Polydopamine (PDA) was used to modify the hydrophilic nature of the nanoparticles surface. Thin‐film nanocomposites as reverse osmosis membranes were made by depositing of polyamide on the mentioned nanocomposites and investigated for removing metal ions like Cu (II), Co (II), Cr (II), Hg (II), Ni (II), Zn (II), and Pb (II) from water. The efficiency of membranes constructing from pristine poly(keto ether sulfone) and different nanocomposites as supporting layer of thin‐film nanocomposite were compared. The prepared membrane based on PDA‐modified MWCNT showed the best performance results including pure water flux of 215 L.m−2.h−1 and rejection of 98% for Cr (II).
Poly(ε‐caprolactone)/montmorillonite nanocomposites via Diels–Alder click reaction
Authors: Ozdogan Tasci Reyhan , Arslan Mehmet , Tasdelen Mehmet Atilla 
Published: December 2021

AbstractSynthesis of nanocomposites by employing inorganic materials as nanofillers is one of the most effective ways to improve the mechanical and thermal properties of conventional polymers. To design and create new nanomaterials with unprecedented functional attributes, the fabrication techniques and chemistries employed often have utmost importance to attain a better structure–property relationship. In this respect, click chemistry‐based functional methodologies hold great promise in the fabrication of polymeric nanocomposites due to their excellent features. In this contribution, poly(ε‐caprolactone)/clay nanocomposites were prepared by Diels–Alder (DA) click reaction of maleimide end‐group containing poly(ε‐caprolactone) and furan functionalized montmorillonite (MMT). The methodology includes furan modification of MMT clay and ring‐opening polymerization of ε‐caprolactone that was initiated with a masked maleimide group containing alcohol and following retro DA reaction to obtain maleimide end group functional poly(ε‐caprolactone). Subsequently, polymer nanocomposites were efficiently fabricated via DA click reaction of functional poly(ε‐caprolactone) polymer and modified clay in thermal heating conditions at 80°C. The characterization of poly(ε‐caprolactone)/clay nanocomposites was carried out by thermogravimetric analysis, Fourier transform‐infrared spectroscopy, X‐ray diffraction spectroscopy, and transmission electron microscopy. Obtained results demonstrated that DA click reaction can be fruitfully employed in the fabrication of MMT‐based polymeric nanocomposites.
Screening for borderline personality pathology on college campuses
Authors: Cano Kiana , Sumlin Eric , Sharp Carla 
Published: December 2021

AbstractAlthough borderline symptoms show a normative decline throughout adulthood, severe psychosocial impairment often remains. Identifying personality pathology in college‐age students may help prevent “adaptive failure” that can occur during the critical period of development from puberty through the late 20s and thus reduce impairment later in life. The aims of the current study were to estimate the prevalence of borderline personality disorder (BPD) in a diverse college sample, determine which symptoms confer the greatest relative risk of screening positive for BPD and examine the utility of the Personality Inventory for DSM‐5 brief form (PID‐5‐BF) in identifying BPD. Participants were 1456 undergraduate students, and 312 individuals (21.4% of the sample) screened positive for BPD. Chronic feelings of emptiness conferred the greatest relative risk of any symptom; students who endorsed this symptom were 15 times more likely to screen positive for BPD than those who did not. Scales and composite scores of the PID‐5‐BF demonstrated diagnostic accuracy ranging from sufficient to excellent. The current study contributes to literature concerning best practices in screening for personality pathology in young adults. Results suggest that chronic feelings of emptiness are significant for detecting at‐risk students and implications for the use of the PID‐5‐BF are discussed.
Benchmark dose modelling in regulatory ecotoxicology, a potential tool in pest management
Authors: Jensen Signe M. , Kluxen Felix M. , Ritz Christian 
Published: December 2021

AbstractFor several authorities, benchmark dose (BMD) methodology has become the recommended approach by which to derive reference values for risk assessment. However, in practice, the BMD approach is not standard use in risk assessment for pesticides where the no observed adverse effect level, lowest observed adverse effect level and effective dose (ED50 or EDx) prevail. Regression‐based BMD and the benchmark dose lower confidence limit (BMDL) have several advantages, such as utilizing more information from the generated data and being less dependent on tested dose levels. However, the BMD approach requires some degree of expert knowledge for defining an appropriate risk level for estimating the BMD and using more sophisticated statistical methods to calculate BMD and BMDL. The BMD approach is one way to move away from p value‐based binary decision‐making towards putting the weight on effect sizes. We review the advantages and disadvantages of focusing on the BMD approach for risk assessment of pesticides. Further, we discuss potential applications in efficacy trials for pest management purposes. © 2021 Society of Chemical Industry.
Improving the assessment of the probability of success in late stage drug development
Authors: Hampson Lisa V. , Bornkamp Björn , Holzhauer Björn , Kahn Joseph , Lange Markus R. , Luo Wen‐Lin , Cioppa Giovanni Della , Stott Kelvin , Ballerstedt Steffen 
Published: December 2021

AbstractThere are several steps to confirming the safety and efficacy of a new medicine. A sequence of trials, each with its own objectives, is usually required. Quantitative risk metrics can be useful for informing decisions about whether a medicine should transition from one stage of development to the next. To obtain an estimate of the probability of regulatory approval, pharmaceutical companies may start with industry‐wide success rates and then apply to these subjective adjustments to reflect program‐specific information. However, this approach lacks transparency and fails to make full use of data from previous clinical trials. We describe a quantitative Bayesian approach for calculating the probability of success (PoS) at the end of phase II which incorporates internal clinical data from one or more phase IIb studies, industry‐wide success rates, and expert opinion or external data if needed. Using an example, we illustrate how PoS can be calculated accounting for differences between the phase II data and future phase III trials, and discuss how the methods can be extended to accommodate accelerated drug development pathways.
Prevalence, incidence, and survival of pulmonary arterial hypertension: A systematic review for the global burden of disease 2020 study
Authors: Emmons‐Bell Sophia , Johnson Catherine , Boon‐Dooley Alexandra , Corris Paul A. , Leary Peter J. , Rich Stuart , Yacoub Magdi , Roth Gregory A. 
Published: December 2021

AbstractPulmonary arterial hypertension (PAH) is characterized by increased resistance in the pulmonary arterioles as a result of remodeled blood vessels. We sought all available epidemiologic data on population‐based prevalence, incidence, and 1‐year survival of PAH as part of the Global Burden of Disease Study. We performed a systematic review searching Global Index Medicus (GIM) for keywords related to PAH between 1980 and 2021 and identified population‐representative sources of prevalence, incidence, and mortality for clinically diagnosed PAH. Of 6772 articles identified we found 65 with population‐level data: 17 for prevalence, 17 for incidence, and 58 reporting case fatality. Reported prevalence ranged from 0.37 cases/100,000 persons in a referral center of French children to 15 cases/100,000 persons in an Australian study. Reported incidence ranged from 0.008 cases/100,000 person‐years in Finland, to 1.4 cases/100,000 person‐years in a retrospective chart review at a clinic in Utah, United States. Reported 1‐year survival ranged from 67% to 99%. All studies with sex‐specific estimates of prevalence or incidence reported higher levels in females than males. Studies varied in their size, study design, diagnostic criteria, and sampling procedures. Reported PAH prevalence, incidence, and mortality varied by location and study. Prevalence ranged from 0.4 to 1.4 per 100,000 persons. Harmonization of methods for PAH registries would improve efforts at disease surveillance. Results of this search contribute to ongoing efforts to quantify the global burden of PAH.
Enhanced Photocatalytic Activity of AgI/BiO2‐x Heterojunction Photocatalyst
Authors: Zhang Xiaoli , Dou Jianyang , Yan Song , Yao Lizhu , Fu Yanfang , Shi Lei 
Published: December 2021

AbstractIn this paper, a new type of AgI/BiO2‐x was successfully obtained. The crystal structure, micro morphology, element distribution and light response ability of AgI, BiO2‐x and AgI/BiO2‐x were observed by XRD, SEM, EDS‐mapping and DRS. The results show that the heterojunction between AgI and BiO2‐x is conducive to electron transfer and improve the separation efficiency of photogenerated carriers. When AgI/BiO2‐x was used to degrade rhodamine B, the reaction rate of the best sample is 0.1405 min−1, which is 6 folds more than BiO2‐x and 2.9 times higher than AgI. After four times cycling experiments, the degradation rate was maintained excellent. Hence, this work provides an effective and steady photocatalyst.
Self‐Limiting Synthesis of Ultrathin Ge(110) Single Crystal via Liquid Metal
Authors: Lan Haihui , Li Yiling , Liu Jinglu , Hu Wenchao , Zhu Xiaohui , Ma Yuxin , Niu Lixin , Zhang Zehao , Jia Shuangfeng , Li Linyang , Chen Yunxu , Wang Jianbo , Zeng Mengqi , Fu Lei 
Published: December 2021

AbstractGermanium, the prime applied semiconductor, is widely used in solid‐state electronics and photoelectronics. Unfortunately, since the 3D diamond‐like structure with strong covalent bonds impedes the 2D anisotropic growth, only the examples of ultrathin Ge along the (111) plane have been investigated, much less to the controllable synthesis along another crystal surface. Meanwhile, Ge(111) flakes are limited in semiconductor applications because of their gapless property. Here, ultrathin Ge(110) single crystal is synthesized with semiconductive property via gallium‐associated self‐limiting growth. The obtained ultrathin Ge(110) single crystal exhibits anisotropic honeycomb structure, uniformly incremental lattice, wide tunable direct‐bandgap, blue‐shifted photoluminescence emission, and unique phonon modes, which are consistent with the previous theoretical predictions. It also confirms excellent second harmonic generation and high hole mobility of 724 cm2 V−1 s−1. The realization of ultrathin Ge(110) single crystal will provide an excellent candidate for application in electronics and optoelectronics.