bluuebunny/crossref_metadata_2025_split huggingface dataset:
Extension of Dynamic Wake Models for Moderate to High Reduced Frequencies
Authors: Peters David A. , Karunamoorthy Swami , Sobol Michael 
Published: March 2022

Abstract
The flow field around a lifting rotor in hover or forward flight is represented by a matched expansion that includes an inner expansion (near the blade chord) and an outer expansion that encompasses the rotor disk. The inner expansion is expanded in Glauert variables and is completely unsteady. It is driven by blade motions and the global flow-field variable λ0 which is provided by the outer expansion. The outer expansion is in terms of rotor harmonics and radial Legendre functions (which are polynomials in r− on the blade). It is driven by the time-rate of change of bound circulation as provided from the inner expansion. Together, these form a robust convergent expansion of the rotor flow field that is good over a broad range of frequencies.
Unsteady Aeroelastic Simulations for Airfoils
Authors: Guilmineau E. , Queutey P. 
Published: March 2022

Abstract
Unsteady flowfields around airfoils pitching or/and plunging are investigated. The objective of this study is to test the ability of our computational code to predict unsteady fluid/structure interaction in the context of the incompressible Navier-Stokes equations. A physically consistent method is used for the reconstruction of velocity fluxes which arise from discrete equations for the mass and momentum balance. To validate the code, a dynamic-stall case is presented. Different cases in fluid/structure interaction are studied. Firstly, we examine the case where the airfoil have only a single plunging degree of freedom. Then, the airfoil can just pitch about the mid-chord. Endly, the airfoil motion consits in plunging and pitching.
Modeling and Control of Martensitic Phase Transitions in Shape Memory Alloys
Authors: Bubner Nikolaus 
Published: March 2022

Abstract
In order to describe phase transitions in shape memory alloys we develop a thermodynamically consistent Landau-Ginzburg model which takes into account an interfacial energy. Ingo Müller conjectures an interfacial energy to be responsible for the hysteresis loops found experimentally. We outline the determination of the physical parameters and present our numerical simulations which agree with the experiments performed by Müller and his co-workers. As an application we will consider control problems, for instance the problem of damping the vibration of a thin rod by heating and cooling.
Investigation of the Quasi-Static Potential of Recurve Actuator Elements
Authors: Ervin James D. , Brei Diann 
Published: March 2022

Abstract
Because most strain generating materials, such as piezoelectrics and electrostrictives, produce small deflections with large forces, some means of strain amplification is often employed to tailor the output of the actuation system to match the need of the application. Various external and internal leverage devices have been developed to amplify strain; however, these devices are commonly inefficient due to transmission losses and can be difficult to pack into constrained application volumes. A Recurve actuator architecture has been designed which amplifies direct material strains and allows for construction of highly packable, high energy density actuator arrays. The Recurve architecture enables arrays that can be tailored to produce specific force and displacement output and can be configured in a variety of ways to make efficient use of available design space. This paper describes a Recurve actuator architecture and presents a quasi-static model relating voltage, force, and deflection along with experimental results for fundamental Recurve actuator elements.
Adaptive Health Monitoring Concepts for Spot-Welded and Weld-Bonded Structural Joints
Authors: Giurgiutiu Victor , Rogers Craig A. , Chao Yuh Jin , Sutton Michael A. , Deng Xiaomin 
Published: March 2022

Abstract
The health monitoring of structural joints is a major concern of the engineering community and needs to be addressed with the proper consideration. Among joining techniques, the spot welding and weld-bonding (spot weld + adhesive bonding) methods are of great interest in a number of industries. Spot welding is the traditional assembly method for steel-based automotive structures, while weld-bonding is a novel technique that combines the stiffness and productivity benefits of adhesive bonding with the proven-technology attributes of spot welding. Future trends in the design and construction of vehicular structures indicate a strong diversification of material usage, with aluminum and polymeric composites projected to play a major role. While aluminum is amenable to both spot welding and adhesive bonding, composites will, most likely, be entirely adhesive bonded. Hence, the trends towards weld-bonding and adhesive bonding are clearly visible.
The paper first presents a short review of the present trends in joining techniques with special emphasis on those in present and future use in the automotive industry. This will be followed by a short review of the existing non-destructive evaluation (NDE) techniques that may be applicable to the health monitoring of spot welded and weld-bonded structures. Next, novel concepts of health monitoring utilizing an adaptive structures approach are presented. Laser ultrasound techniques; tagged adhesive methods; dielectric response techniques; electric potential methods, etc. are briefly mentioned.
Particular emphasis is placed on the electro-mechanical impedance method. This novel method is described in some detail. The electro-mechanical impedance method utilizes the coupled electro-mechanical response of piezo-electric interrogators (sensor-actuator crystals) intimately bonded to the monitored structure. An array of such structural interrogators can be envisaged to monitor the incipient local damage and crack growth in spot-welded and weld-bonded structures. Preliminary proof-of-concept demonstration tests performed with this method have shown remarkable features and ease of utilization.
Active Noise Control of Piston-Cavity Systems
Authors: Baz A. 
Published: March 2022

Abstract
Sound propagation in one-dimensional piston-cavity systems is controlled using Active Compressional Damping Treatments (ACDT). The treatments rely in their operation on a classical Den Hartog damper system whose dynamics are controlled in response to the sound pressure level inside the cavity. The interactions between the piston, acoustic cavity and the controller are modeled using the classical impedance approach as well as the finite element method. The developed models are used to predict and compare the sound pressure fields developed inside the cavity for pistons with and without the ACDT treatments. Comparisons are also made when the pistons are treated with conventional Passive Compressional Damping Treatments (PCDT) which are ACDT operating in their open-loop mode. The obtained results suggest the effectiveness of the ACDT concept in attenuating the sound propagation inside cavities and its potential in controlling the sound pressure fields inside three-dimensional cavities.
Host-Active Component Interactions and Performance Predictions
Authors: DeGiorgi V. G. 
Published: March 2022

Abstract
The performance of an integrated smart material or device is dependent on the combined performance of active and passive components. Material and geometric interactions often result in a device with complex performance characteristics. Therefore, in the design of a device, computational models which incorporate active and passive materials are a valuable tool. The present work tracts the analyses performed using such models during the design of a smart panel designed for acoustic quieting. Emphasis is placed on structural integrity and total surface displacement achieved by the device.
Experimental Investigation of Composites With Piezoelectric Actuation and Debonding
Authors: Seeley Charles E. , Chattopadhyay Aditi 
Published: March 2022

Abstract
Piezoelectric transducers can be used as sensors and actuators for vibration reduction in composite structures. Debonding at the transducer-laminate interface results in significant changes to the dynamic response and control authority. This important issue is studied in the current work. Composite specimens with surface bonded piezoelectric transducers were constructed with varying stacking sequences and debonding lengths. Closed loop control was implemented using an analog circuit. Experimental results were obtained for both open and closed loop frequencies and damping ratios. The results correlate well with a newly developed higher order based theory for modeling composites with debonded piezoelectric transducers. Significant changes are observed in the open and closed loop frequencies and damping ratios as a result of debonding.
Optimal Size and Location of Piezoelectric Actuator/Sensors: Practical Considerations
Authors: Aldraihem Osama J. , Singh Tarunraj , Wetherhold Robert C. 
Published: March 2022

Abstract
In this paper, we address the problem of obtaining the optimal size and location of piezoelectric actuator/sensors. An optimization problem is formulated for a general beam which has arbitrary boundary conditions and may have as many piezoelectric actuators as desired. The proposed optimization criterion is based on the beam modal cost and modal controllability. If the size of the actuator is unbounded, it frequently is optimal if it covers most if not all the length of the beam. This is not realistic, since there are cost, weight, and space factors to be considered. By adding a penalty term to the criterion, the size of the actuator/sensor can be reduced to a practical and reasonable size. Thus there is no need to pre-select the size of the actuator/sensor. The optimal size and location for beams with various boundary conditions are determined for a single pair and for two pairs of actuators. The results in this paper are in very good agreement with those reported by other investigators. A comparison is also made between the performance of two pairs of actuators and the performance of a single pair. The improvement in performance with two pairs is quantified.
Virtual Reality Assisted Measurement of In-Vivo Cervical Spine Kinematics
Authors: DeFrate Louis E. , Doehring Todd C. , Nishida Kotaro , Kang James D. , Gilbertson Lars G. , Woo Savio L.-Y. 
Published: March 2022

Abstract
In-vivo biomechanical studies of cervical spine movements are useful for defining “kinematic envelopes” of motion. Data are readily available on the ranges-of-motion of the cervical spine in flexion/extension, left/right lateral bending, and left/right axial rotation [1]. There is increasing evidence that “combined movements” may also be of clinical importance [2,3,4]. In this study, we tested the hypothesis that axial rotation limits active flexion/extension of the cervical spine. We used a specially developed measurement system featuring a 3-D magnetic tracking device with virtual reality technology that enables subjects to perform combined movements that would otherwise be difficult to achieve.
Standing Assist Device
Authors: Murphy Benjamin , Mickens LaKeshia , NeSmith Leslie 
Published: March 2022

Abstract
People confined to wheelchairs often find that they cannot reach things that are easily reached by those who can stand. They also have a tendency to have more gastrointestinal problems than other people. In order to alleviate some of these problems, a standing assist device was designed and built, for under $1,000, to add to the frame of a manual wheelchair. The device allows the user the ability to reach things that were out of reach. It also allows the user to stand, alleviating many causes of gastrointestinal problems. The design was evaluated by a person with paraplegia.
Not Viscous Drag but Matric Forces Are Responsible for Skin Barrier Function
Authors: van Kemenade Patricia M. , Huyghe Jacques M. , Douven Lucien F. A. 
Published: March 2022

Abstract
The outermost layer of the skin, the stratum corneum is only about 20 microns thick, yet plays an important role in preventing an excessive loss of body fluids to the dry environment. By damaging the stratum corneum (mechanically or chemically) the transepidermal water loss (TEWL) increases. For instance removing the whole stratum corneum by stripping the skin with adhesive tape increases the water loss by 10 times (Lo et al., 1990), and after two successive exposures of skin to a detergent solution water loss is almost twice the basal value (Barel et al., 1995).
Lung-Diaphragm Model of the Respiratory System for Parameter Estimation Studies
Authors: Macia Narciso F. , Dorson William J. , Higgins Walter T. 
Published: March 2022

Abstract
Often respiratory models exclude the diaphragm input and its associated dynamics since they are normally inaccessible. However, some parameter estimation techniques [1–3] while requiring all the inputs to be known, subtract the inputs that are not accessible through measurement. This approach permits the identification of all parameters even though all the inputs are not available.
Hydrogel Based Artificial Heart Valve Stent
Authors: Hui Andrew J. , Duncan Anthony C. , Wan W. K. 
Published: March 2022

Abstract
Hydrogels have many medical applications. In this particular case, it is proposed to fabricate a heart valve stent from polyvinyl alcohol (PVA). The present heart valve stents are made of rigid materials which do not mimic the natural important mechanical properties of the aortic root such as expansibility1. We propose a new heart valve stent which can better mimic the natural mechanical properties of the aortic root.
A New Approach to Understanding Starling’s Law at the Microstructural Level
Authors: Hu Xiaping , Curry Fitzroy , Weinbaum Sheldon 
Published: March 2022

Abstract
1996 marked the 100th anniversary of Starling’s classic paper proposing that the capillary wall behaves like a semipermeable membrane in which there is net filtration on the arterial side and a net absorption on the venous side due to the colloidal osmotic pressure of plasma proteins. While the validity of the general premise was experimentally demonstrated by Landis in 1930, who showed that in human skin capillaries at heart level that the two competing flows nearly balance one another with the small excess resulting in a lymph flow, recent experiment summarized in [3] have shown that the simple Landis-Starling diagram shown in most textbooks is not true in nearly all other body locations. In nearly all tissues in which detailed measurements of the plasma and interstitial hydrostatic and oncotic pressures have been made along the length of the calillary there is little reabsorption on the venous side since the local interstitial oncotic pressure rises sharply as the flow rate is reduced. This has been beautifully demonstrated by Michel and Philips [3] in individually perfused frog mesentery capillaries, where it is shown that the interstitial colloidal osmotic pressure depends critically on the filtration rate and there is still a small positive net filtration on the venous side. This intriquing paradox has just been reviewed in Michel (1997).
In the proposed paper a new theory is presented to describe the detailed structure of the osmotic gradients and flows across the endothelial surface glycocalyx, the inter-endothelial cleft and the exit region downstream of the cleft exit. The heterogeneity of the flow across the surface of the glycocalyx caused by the local breaks in the junction strand and the non-uniformity of the protein concentration both behind the surface glycocalyx and across the junction strand is considered for the first time. The non-linear coupling of the local fluid flow to the local plasma protein concentration is examined and it is shown that the primary gradient in osmotic force is felt across the surface layer of matrix. The model shows rather remarkably that there there is a heretofore unrecognized large asymmetry in the fluid flow pattern on each side of the junction strand and that the water enters the cleft nearly uniformly along its length despite the widely separated discrete breaks that have been observed in the junction strand [1]. The model provides very good predictions of the experimental measurements in Michel and Philips [3].
Probabilistic Modeling of Rosette Formation
Authors: Long Mian , Zhu Cheng 
Published: March 2022

Abstract
Rosetting is a simple assay for specific cell-cell adhesion [1]. Although routinely used by immunologists to examine the functionality of the interacting receptors and ligands, it has not been regarded as a quantitative method, as the measured rosette fraction has not been quantitatively related to the underlying molecular properties.
Pulsatile Non-Newtonian Flow in a Double Aneurysm
Authors: Guzmán Amador M. , Moraga Nelson O. , Amon Cristina H. 
Published: March 2022

Abstract
An aneurysm is a permanent balloon-like, blood-filled dilatation on an arterial vessel. In an abdominal aortic aneurysm (AAA), the growth and eventual rupture of aneurysmal lesions depends on the interaction between the aneurysm wall and the blood motion along it. Rupture of an aneurysm occurs when the shear stresses exceed the strength of the wall [1]. When an AAA ruptures, 50 percent of patients die before reaching the operating room and 54 percent of the remaining will die within 30 days [2]. Therefore, AAA represents a great danger to the patient [3]. The objective of this study is to investigate the shear stresses in an aneurysm composed by two deforned regions and to examine the effect of the blood non-Newtonian behavior on the flow dynamics.
Numerical Simulation of Korotkoff Sounds
Authors: Hayase Toshiyuki , Hayashi Satoru , Xia Yupeng , Koizumi Tadao 
Published: March 2022

Abstract
Although occurrence of Korotkoff sound is essential in blood pressure measurement with sphygmomanometer, there exist several explanations for its mechanism [1]. The authors have made the study on stability of collapsible tube flow using a Starling register [2]. In this system large deformation of the collapsible tube takes place in the downstream end of the tube and the effect of the rigid pipe is inevitable. In the present report, numerical analysis is performed for a modified system in which external pressure is applied in the limited region of a long collapsible tube to avoid the effect of the rigid pipe. Supply pressure is changed as sinusoidal function of time to model the blood pressure pulsation. Mechanism of the Korotkoff sound generation is examined based on the computational result.
Do Temporal Wall Shear Stress Gradients Promote the Development of Intimal Hyperplasia Within Vascular Bypass Grafts?
Authors: Keynton Robert S. , Evancho Mary M. , Sims Rick L. , Rodway Nancy V. , Rittgers Stanley E. 
Published: March 2022

Abstract
The purpose of this paper is to determine the relationship between the temporal wall shear stress gradient and the development of intimal hyperplasia (IH) within an in vivo animal model of the distal anastomoses of vascular bypass grafts. Tapered Teflon® grafts were placed in the common carotid arteries of adult, mongrel dogs with 30° end-to-side proximal and distal anastomoses and a graft-to-artery diameter ratio of either 1:1 or 1:1.5. Simultaneous axial velocity measurements were obtained using a specially designed 20-MHz ultrasonic wall shear rate transducer. Peak and oscillatory temporal WSSGs were found, at best, to only weakly correlate with IH (r = 0.20 and r = 0.27, respectively). The results from this study suggest that the temporal WSSG parameter, by itself, does not promote the development of IH.
Vein Cuffs May Improve Anastomotic Patency by Reducing Suture-Line Intramural Stresses
Authors: Ballyk Peter D. , Ojha Matadial , Walsh Colin 
Published: March 2022

Abstract
Intimal hyperplasia (IH) is an important complication of arterial bypass surgery which can ultimately lead to graft failure. The pathogenesis of IH involves the migration of smooth muscle cells from the media to the intima where they proliferate and secrete extracellular matrix. This results in a thickened vessel wall which may cause stenosis and/or thrombosis of the distal graft-artery junction. It has been shown that IH is a more significant problem in stiff synthetic grafts than in more compliant vein grafts (Bassiouny et al., 1992), and that synthetic grafts have a higher failure rate (Waiden et al., 1980). Consequently, autogenous vein (or artery) grafts are used clinically whenever possible. In cases where autogenous grafts are not long enough or not available (for e.g. if they have already been harvested or have been obliterated by disease), a vein cuff interposed between the distal end of a synthetic graft and the host artery can improve long term patency by reducing distal anastomotic IH (Miller et al., 1984; Suggs et al., 1988).
Finite Element Modeling of Scleral Creep and Ocular Elongation in Deprivation-Induced Myopia
Authors: Grissom Jerry D. , Siegwart John T. , Eberhardt Alan W. 
Published: March 2022

Abstract
Myopia (nearsightedness) is a condition in which the axial length of the eye is longer than the focal plane and, therefore, images of distant objects are blurred. Discoveries that the environment plays a critical role in ocular development (eg., [1]) suggest that there is a visually guided feedback mechanism by which the axial length is matched to the unaccommodated focal plane (emmetropization). Studies have shown increased scleral creep rates associated with form deprivation myopia [2] suggesting that regulation of creep may be responsible for emmetropization, while excessive unregulated creep may result in myopia.
Measuring the Probability of Receptor Extraction From the Cell Membrane
Authors: Chesla Scott E. , Marshall Bryan T. , Zhu Cheng 
Published: March 2022

Abstract
Recently, there has been an increasing interest in measuring the interaction forces between cell adhesion receptors and their ligands [1–3]. These molecules are either anchored on the membrane of a cell or coated on the surface of a substratum. The two surfaces are joined together as a result of the formation of non-covalent bonds between the receptors and ligands. The forces are measured when the two surfaces are separated. In a theoretical paper published nineteen years ago, George Bell estimated the force required to break a receptor-ligand bond and that required to uproot the receptor from the cell membrane to be of the same order of magnitude [4]. The interpretation of the force data therefore requires the knowledge of detachment mode, i.e., via adhesive mechanism if the receptor-ligand bond is dissociated or via cohesive mechanism if the receptor-membrane anchor is disrupted.
The Large-Deformation Behavior of Mesenchymal Distraction Gap Tissue
Authors: Richards Mark , Hernandez Michael J. , Weiss Jeffrey A. , Wineman Alan S. , Goulet James A. , Goldstein Steven A. 
Published: March 2022

Abstract
A combined experimental and computational approach was adopted to determine a constitutive relationship for mesenchymal gap tissue generated during distraction osteogenesis. Harvested distraction zones were tested to failure in uniaxial tension and 3-D FE models were constructed to simulate mechanical testing. A specific form for the strain energy function was adopted to obtain strain-stiffening behavior. Theoretical uniaxial tension predictions were consistently lower than those from 3-D FEA. By refining the values of the three material parameters, a force-displacement curve in excellent agreement with the experimental results was obtained. This formulation appears capable of capturing the essential elements of the behavior of distraction gap tissue. These results can be implemented to predict strain distributions within this tissue and improve our understanding of how the mechanical environment affects bone regeneration and precursor tissue differentiation during distraction.