bluuebunny/crossref_metadata_2025_split huggingface dataset:
Finite Shear Behaviour of Brain Tissue Under Impact Loading
Authors: Brands Dave W. A. , Bovendeerd Peter H. M. , Peters Gerrit W. M. 
Published: November 2021

Abstract
A method is presented for determining the dynamic shear behaviour of brain tissue using a rotational plate-plate rheometer in a strain and frequency range representative for impact conditions. The non-linear strain behaviour was characterised using shear stress relaxation experiments and expressed in terms of a damping function. Results were corrected for the non-homogeneous strain field applied. Brain tissue was found to exhibit shear softening (45% at 20% strain) that could be fitted with a second order Mooney-Rivlin model. The time dependent behaviour of brain tissue seems to be independent of the strain level. It was characterised up to 1000 Hz by small strain oscillatory shear experiments and application of the Time Temperature Superpositioning principle. The data presented can be used to fit a non-linear material model for brain tissue under shear loading for frequencies up to 1000Hz and strains up to 20%.
Influence of Stent Design on Intraaneurysmal Flow: A PIV Study
Authors: Livescu V. , Lieber B. B. , Hopkins L. N. , Wakhloo A. K. 
Published: November 2021

Abstract
Interaction between stents and flow inside a sidewall aneurysm model was investigated using Particle Image Velocimetry (PIV). Three spring-like stents having the same porosity but different filament diameter were placed inside the parent vessel that harbored the aneurysm traversing the aneurysmal neck. The flow field inside the aneurysm was investigated before and after placement of the stents. The flow through model was pulsatile and the hemodynamic conditions were representative for those found in human intracranial and extracranial cerebral arteries. Flow patterns inside the aneurysm were significantly altered after stent placement. To facilitate comparison among all cases, the circulation inside the aneurysm was obtained as the surface integral of the distributed vorticity. The results show that the strength of the circulation is substantially diminished for all stented cases. However, the temporal distribution of the circulation through the cardiac cycle is similar for the three stents considered. Further, the mean circulation over one cardiac cycle was obtained for each case as the integral of the absolute value of the temporal distribution. The mean circulation reveals that noteworthy differences in intraaneurysmal hemodynamics do exist among the filament diameters considered.
Biomechanics as a Tool for Study of Cardiovascular Disease: Will We Predict Cardiovascular Disease With Engineering Precision?
Authors: Schmid-Schönbein Geert W. 
Published: November 2021

Abstract
With the impending completion of the human genome sequence, biology will join the ranks of physics, mathematics, and chemistry as an exact basic science. This fact will be reflected in the choice of the curriculum for many academic disciplines, but especially for Bioengineering. Bioengineering, and specifically Biomechanics, will integrate these disciplines and serve as the platform for expanding analysis as well as creation and design of new approaches in Biology and Medicine. Not only is mechanics determined by biology but also biology is controlled by mechanics. Thus, biomechanics is becoming an integral part of medical research. One of the most interesting aspects of biomechanics is its application to problems related to disease (1).
Mechano/Transduction, Cellular Communication and Fluid Flow in Tissue Engineering
Authors: Weinbaum Sheldon 
Published: November 2021

Abstract
The growth of cellular constructs in tissue scaffolds depends on the delivery of nutrients and growth factors as well as the substrate on which they are grown. Micropatterning techniques have also made it possible to grow cells on a wide variety of substrates with greatly different topography which significantly alter cellular contact and communication. Fluid flow is critical not only in this delivery of nutrients and growth factors, but also in the interaction of the cell’s cytoskeleton with its attachment matrix. Similarly, fluid flow is known to play an important role in cell to cell communication via its regulatory effect on various gap junction proteins of the connexon family. The mechano/transduction and cell to cell signaling mechanisms will be examined for both cells with a smooth topography, such as vascular endothelium cells which are involved in angiogenesis and cells with cell processes and microvilli whose tethering attachments and protrusions interact with fluid flow in a different manner.
Molecular Mechanics and Cell Biology: Growing Cells on Soft Materials
Authors: Ju Yo-El , Janmey Paul A. , Flanagan Lisa A. 
Published: November 2021

Abstract
The vast majority of studies of cell growth and movement in vitro are done on rigid glass or plastic surfaces laminated with a molecular layer of specific adhesion proteins. Such studies have revealed a wealth of information about the functions of soluble and surface-bound ligands as well as the structure and components of the cytoskeletal machinery. However, the morphology, motility, and metabolic states of such cells do not often resemble the situation in vivo, where, for example, the materials to which cells attach are much softer. Recent developments in synthesis and characterization of polymer gels that allow quantitative studies of cell function have revealed that mechanical effects may be as important an aspect of cell regulation as the specific molecular stimuli traditionally studied. Designing chemically defined surfaces that permit cells to grow on materials with viscoelastic properties that resemble those of normal tissues is a step to elucidating the influence of mechanics on cell growth and structure.
A Mathematical Model of a Retinal Oscillator
Authors: Rand Richard H. , Wirkus Erika T. , Li Tong , Howland Howard C. 
Published: November 2021

Abstract
Circadian rhythms in vertebrates (including man) have been conjectured to help control changes in sensitivity of visual systems (which must operate over some 10 orders of magnitude in the course of night and day), by anticipating the changes in light intensity which occur at dusk and dawn (Cahill and Besharse, 1995). Diurnal rhythms in melatonin and dopamine in the retina have been shown to be affected both by a circadian oscillator as well as by changes in local light levels (Cahill and Besharse, 1995). In an experiment conducted in the laboratory of one of the authors (HCH), the growth of the eyes of baby chicks in their first two weeks of life has been shown to be strongly affected by exposure to 20 hours or more of light per day (Li et al., 2000). A descriptive model of the nature of the biochemistry of retinal dynamics has been presented (Morgan and Boelen, 1996). In this work we offer a mathematical model of the retinal oscillator based on the descriptive model given in (Morgan and Boelen, 1996). Using this model we simulate the experiment described in (Li et al., 2000).
On the Calculation of Fluid Shear Stresses at the Wall of Dilated Large Arteries: Part I—Application to 2D Axisymmetric Computational Models
Authors: Finol Ender A. , Amon Cristina H. 
Published: November 2021

Abstract
A procedure for calculating fluid shear stresses at the wall of two-dimensional axisymmetric models of dilated large arteries is presented. The procedure is applied to a model of a double-aneurysm abdominal aorta under pulsatile flow conditions for a time-average Reynolds number Rem = 680. The method is extended to three-dimensional artery models in Part II of this paper.
Development of Interactive Modeling System for the Computational Biomechanics Simulation Using Medical Imaging Data
Authors: Hayasaka Tomoaki , Himeno Ryutaro , Fukuyama Keisuke , Liu Hao , Yamaguchi Takami 
Published: November 2021

Abstract
Computational mechanics has been recognized as a powerful tool for cardiovascular disease research, vascular surgery planning and medical device design. The accurate and efficient construction of anatomic models is a critical element in the application of these computational methods. We developed an interactive modeling system for the computational biomechanics simulation using medical imaging data such as MRI or CT. The novel aspect of this modeling system is that the operator can modify the model which is rendered over the reference volumetric images. Therefore efficient modeling can be done with help of the heuristic knowledge of the operator.
Fluid-Structure Interactions Abdominal Aortic Aneurysm Models Under the Pulsatile Flow Condition
Authors: Kwon Chi-Ho , Lee Ki-Won , Kim Young-Ho 
Published: November 2021

Abstract
Fluid-structure interaction studies were performed on various abdominal aortic aneurysm (AAA) models under the pulsatile flow condition. Eight aneurysm models were made with four different dilatation sizes and two different wall thickness. Stresses and deformations of the aneurysm wall were significantly affected by the dilatation size as well as the wall thickness. The change in wall thickness increased with the more dilated aneurysm. In spite of considerable radial deformations, axial deformations of the aneurysm wall were dominant. The present study showed the strong possibility to understand fluid-structure interactions in the human cardiovascular system.
Comparison Between a Quasilinear and a Nonlinear Viscoelastic Model for Brain Tissue
Authors: Darvish Kurosh K. , Crandall Jeff R. 
Published: November 2021

Abstract
The nonlinearity of the viscoelastic behavior of brain tissue was studied. Two nonlinear constitutive models were developed using the experimental results of forced vibrations on bovine brain samples, namely a quasilinear viscoelastic model and a multiple hereditary integral model. The latter was found to be superior especially at higher frequencies (above 27 Hz).
Determination of Mechanical and Fluid-Species Transport Properties for Soft Tissues
Authors: Rigby Paul H. , Morgan Nathaniel R. , Simon Bruce R. , Williams Stuart K. 
Published: November 2021

Abstract
A series of experiments have been developed in order to determine some of the mechanical and fluid-species transport properties of rabbit carotid arteries. The properties to be determined in this study are mechanical parameters, water permeability, and species diffusion parameters for the intima and media.
Sensitivity of Modeling Parameters in Proximal Femur Analyses
Authors: Wang Eric L. , Jiang Yanyao , Fan Lixia , Greer Brian 
Published: November 2021

Abstract
Hip fracture risk can be quantified using a factor of risk (Hayes et al., 1996): (1) Φ = Applied load / Fracture load
The structural capacity, the denominator, can be affected by many parameters including femoral geometry, material properties, load locations, loading direction, loading rate, and frictional resistance.
Mechanisms of Creep-Induced Failure in Cylindrical Cortical Bone Specimens due to Radial Loading
Authors: Brown Christopher U. , Parsamian Gagik P. , Norman Timothy L. , Kish Vincent L. , Gruen Thomas A. , Blaha J. David 
Published: November 2021

Abstract
Damage mechanisms in human femoral cortical bone due to a constant radial load were studied in cylindrical specimens. Characterizing this damage is important for understanding its role in press-fit total hip arthroplasty. Cylindrical bone specimens were loaded at a constant internal pressure until failure. Sections were removed for microscopic observations. More microcracks were observed near the endosteal surface, as compared to the outer surface, and were located within the bone matrix and ended at a cement line. Tensile hoop and compressive radial stresses tend to open microcracks in the hoop direction resulting in cracks oriented in the radial direction.
Application of CFD in Designing Spacers: A Novel Approach
Authors: Jalili Vahid , Patel Mayur K. , Bailey Christopher 
Published: November 2021

Abstract
The aim of this paper is to report on a novel approach used in designing spacer (a biomedical device used to aid inhalation of the drug). The Computational Fluid Dynamics (CFD) technique has been around for some years, but to date has not been used in designing spacers. In the present study the commercial CFD engines used were FLUENT-5.1.1 and PHOENICS. The study covered a large area taking into account various parameter changes such as the inlet boundary condition i.e. changing the velocity at inlet, varying the jet angle at entry to the spacer and the actual length of the spacer. The results were possible were compared to the experimental data available and generally the comparison was good. The findings from this research have highlighted, that there is an optimum size of 6cm and inlet velocity of 30m/s which result in an increased efficiency. It was also found that there is an optimum time of 0.4 sec. For which the highest drug concentration appears to be present.
Branch Flow Effects in the Human Right Coronary Artery Trunk
Authors: Myers Jerry G. , Ojha M. , Johnston K. Wayne , Ethier C. Ross 
Published: November 2021

Abstract
Formation of atherosclerotic plaque in the human right coronary artery (RCA) has, in part, been linked to local hemodynamic factors (Ojha et al., 2000). Thus, there is considerable motivation to accurately characterize hemodynamic patterns in the RCA. Patient-specific geometric characteristics, such as curvature and arterial calibre, have been shown to significantly affect velocity and wall shear stress (WSS) patterns within the RCA trunk (Myers et al., 2000). However it is unclear how flow into arterial branches influences these hemodynamic patterns. In investigating this factor, we computed velocity and WSS distributions in a realistic model of a human right coronary artery (RCA) that included four branches.
Wall Shear Stress and Gradient at Anterior Communicating Artery in Pulsating Flow
Authors: Yamaguchi Ryuhei , Kudo Susumu , Yamanobe Hiroyuki , Nakajima Mikio , Ujiie Hiroshi 
Published: November 2021

Abstract
The aneurysm in the cerebral artery is apt to initiate around the “Circle of Willis”. The anterior communicating artery (ACoA), which composes one of major part of the circle of Willis, is the most predilection artery of the aneurysm. This artery is characterized by a singular geometry. At this artery, two proximal anterior cerebral arteries (A1, confluence) join facing each other. Just at this artery, the flow bifurcates two distal anterior cerebral arteries (A2, bifurcation). Namely, this artery has a function as a bypass channel. Therefore, the flow around the anterior communicating artery would be very unstable. The aneurysm arises around the apex of this artery where the confluent flow collides.
Driving Simulation of Electric Wheelchair on Snowy Roads
Authors: Tadano S. , Uchiyama K. , Tsukada A. , Takahashi H. , Ukai T. 
Published: November 2021

Abstract
An appropriate wheelchair is greatly desired for outdoor use during the winter season in a snowy region. To develope the electric wheelchair, three types of electric wheelchair were tested for their drivability on an icy road, a snow-covered road and an indoor floor. In addition, computational method was proposed to simulate the drivability of a wheelchair on the snowy road condition.
Statistical Modeling of Microstructural Effects on Fatigue Behavior of α/β Titanium Alloys
Authors: Soboyejo A. B. O. , Shademan S. , Sinha V. , Soboyejo W. O. 
Published: November 2021

Abstract
This paper presents the results of combined experimental and theoretical studies of the effects of colony microstructure on fatigue crack growth in Ti-6Al-4V. Colony microstructures with controlled lath widths and colony sizes are produced by controlled cooling from the β phase field. For colony microstructures with approximately 20 vol% of β phase, the fatigue crack growth rates are shown to decrease with increasing α lath and colony size. A new statistical multiparameter modeling methodology framework is proposed for the assessment of the combined effects of mechanical and microstructural random variables on the fatigue crack growth rate. Excellent statistical correlation has been observed between the theoretical model and experimental data. The implications of the results are also discussed for the estimation of fatigue life.
Life Prediction: The Need for a Mechanistically Based Probability Approach
Authors: Harlow D. Gary , Wei Robert P. 
Published: November 2021

Abstract
Concerns with life assessment and management for existing engineered systems and aging infrastructure worldwide have increased the emphasis on the development of methods for reliability and durability predictions. Increasingly it is being recognized that the traditional statistically and empirically based methods are inadequate. These methods are appropriate for interpolations, but their usefulness for extrapolation is limited. Effective predictors, i.e., those that provide precise estimates beyond the range of conditions employed in the development of supporting data and assessments of risk, must be based upon mechanistic models that capture the functional dependence on all the key external and internal variables. This type of modeling, to reflect typical industrial applications, requires multidisciplinary research that addresses the chemical and micromechanical processes that control damage evolution in materials and quantifies the stochastic aspects of these processes. The purpose of this paper is to demonstrate the use and applicability of the mechanistically based probability methodology and to provide a framework from which other applications can be addressed. The approach is illustrated through mechanistically based probability modeling of corrosion and corrosion fatigue of aluminum alloys and creep crack growth in high strength steels.
Contact Damage of Model Dental Multilayers: Experiments and Finite Element Simulations
Authors: Soboyejo W. O. , Wang R. , Katsube N. , Seghi R. , Pagedas C. , Skraba P. , Mumm D. , Evans A. G. 
Published: November 2021

Abstract
This paper presents an overview of recent studies of contact damage in multilayered structures with equivalent elastic properties to bonded dentin/crown structures. Following a brief review of restored tooth structures, prior work on the development of model dental multilayered structures is reviewed. The review examines the two sides of the current debate on the applicability of Hertzian indentation tests to real clinical scenarios. In particular, the potential effects of indentation ball size are identified as some of the reasons for the “apparent” discrepancies in the literature. An experimental framework is then presented for the exploration of the effects of ball size on contact damage mechanisms in dental multilayers. The observed cracking patterns at the onset of crack nucleation are shown to be associated with principal stress contours computed using elastic-plastic finite element models. The statistical variations in the crack nucleation loads are shown to be well described by Weibull (weakest link) statistics. The implications of the results are discussed for the design of dental multilayers that are more resistant to crack nucleation and propagation.
Corrosion and Wear Behavior of Al 2024 Alloy Coated With Intrinsically Conductive Polymers, ICPs
Authors: Shah Kunal , Iroh Jude O. , Akundy G. , Zhu Yanrong , Popoola O. 
Published: November 2021

Abstract
The Corrosion behavior of aluminum alloys coated with intrinsically conducting polymers, ICPs, such as polyaniline, polypyrrole and their composites has been determined. The corrosion rate of the coated substrates is significantly reduced in the presence of the ICP coating. However, the corrosion resistance of the coated Al was found to be strongly dependent on the electrochemical processing variables such as the applied current density, pH and the deposition time. Both low current densities, i 3/4 2 mA/cm2 and high current densities, i &gt; 6 mA/cm2, resulted in high corrosion currents and low corrosion rates. Also the ICP coatings deposited at very short and very long deposition times, respectively, show decreased corrosion performance. In our presentation, we will discuss the effects of electrochemical processing variables on the surface structure and corrosion performance of ICPs coated Al.
Mathematical Modeling of High Velocity Oxygen Fuel Thermal Spraying: An Overview
Authors: Cheng D. , Trapaga G. , McKelliget J. W. , Lavernia E. J. 
Published: November 2021

Abstract
High velocity oxygen fuel (HVOF) thermal spraying is a versatile technique widely used for the manufacture of coatings from various materials system. The physical, mechanical, and chemical characteristics of a coating are critically influenced by the operating parameters used to obtain maximum coating performance while minimizing experimentation. In this paper, modeling of HVOF thermal spray processes is reviewed, paying particular attention to combustion, gas/particle dynamics, particle impingement, and coating formation.
Modeling Fatigue Damage in Chemically Treated Soft Tissues
Authors: Slaughter William S. , Sacks Michael S. 
Published: November 2021

Abstract
Chemically treated, biologically derived tissues are used extensively in cardiac valve bioprostheses. Unfortunately, while extensive research has focused on chemical treatment technologies to reduce negative in-vivo effects such as mineralization and to enhance overall biocompatibility, little work has been done on understanding the effects of fatigue on tissue mechanical properties. In the current work, a structure-based damage mechanics model for the evolution of mechanical properties with cyclic loading of chemically treated soft tissues is presented. The model is used to clarify and relate the impact of different structural changes, such as collagen fiber debonding and collagen fiber weakening, to changes in macro-level tissue mechanical properties. The fatigue damage model will ultimately serve as a guide for the development of key experiments for fatigue damage assessment of novel chemical treatment technologies. This will aid in the rational development, as opposed to the current ad-hoc approach, of novel chemically modified collagenous biomaterials for more durable cardiac valve bioprostheses.
On Numerical Simulations of Complex Flows of Viscoplastic Materials
Authors: Souza Mendes Paulo R. , Naccache Mônica F. , Vinagre Harry T. M. 
Published: November 2021

Abstract
The performance of a typical numerical simulation for complex flows of viscoplastic materials was examined. The inertialess flow of viscoplastic materials through an axisymmetric channel formed by an abrupt expansion followed by a contraction was employed with this purpose. Flow visualization experiments were performed with a well characterized Carbopol aqueous solution. Numerical solutions of the mass and momentum balance equations were obtained, using the Generalized Newtonian Liquid model with a biviscosity function. The flow visualization results showed that the flow pattern is essentially Newtonian for large expansion lengths. For smaller expansion lengths, however, flow is observed only in an inner axisymmetric region whose diameter is approximately the same as the one of the inlet and outlet tubes. Outside this region the flow is stagnant, and a slip interface between these two regions seems to occur. The corresponding numerical solution was not capable of predicting the observed flow pattern.