bluuebunny/crossref_metadata_2025_split huggingface dataset:
Occupant Motion Modeling in Rollover Accidents: Effects of Ellipsoid Surface Contact Characteristic Variations
Authors: Renfroe David A. , Partain Joe F. 
Published: January 2022

Abstract
In order to facilitate the design of safer occupant vehicle environments a method has been demonstrated whereby occupants in a rollover collision may be modeled. The modeling technique has previously been demonstrated (Renfroe, et.al., 1998). This publication reviews the previous work and illustrates how the stiffness, damping, hysterisis, and coefficient of friction describing each ellipsoid contact representing the vehicle striking the road does not have to be precisely the measured stiffness characteristics.
Computer Simulations of Human Neck Loads in a Car Equipped With an Airbag
Authors: Luan Feng , Zhao Longmao , Yang King H. 
Published: January 2022

Abstract
It has been shown that driver fatalities in frontal collisions were reduced by 28% in airbag-equipped cars based on comparisons with similar cars equipped with manual lap/shoulder belts only (Zador and Ciccone, 1991). A similar finding was reported by the Department of Transportation that driver fatality rates in airbag equipped cars were reduced by 31% in purely frontal crashes (12:00 point of impact on the vehicle), and 19% in all frontal crashes (10:00 to 2:00). About 10% of drivers of vehicles with airbags involved in accidents received moderate to severe injuries. Most, if not all, of these people would have been more seriously injured or killed without the airbag. In a recent report to Congress, NHTSA estimated that airbags have saved 1,198 lives from 1987 through 1995, including 475 lives saved in 1995 alone.
Stability of the Lumbar Spine Subjected to a Follower Load: Part II — Theoretical Results
Authors: Meade Kevin P. , Patwardhan Avinash G. 
Published: January 2022

Abstract
A number of theoretical studies of the stability of structures subjected to follower loads have been reported in the literature. The classic example is due to Beck who, in 1952, investigated the stability of a cantilevered beam-column subjected to a load applied to its free end that remained exactly tangent to the deflection curve (Atanackovic, 1997 and Timoshenko, 1961). To obtain the critical load it was necessary to perform a dynamic analysis of the problem. In problems such as these, instability comes in the form of flutter rather than divergence.
The purpose of this study was to assess the stability of the lumbar spine under loading conditions similar to those in Patwardhan, et al., 1998. In their experiments, a follower load was applied to the lumbar spine using guided cables that remained tangent to the deformed shape of the lumbar curve. In this study we adopted a model similar to Crisco and Panjabi (1992a) but with important differences.
Crisco and Panjabi (1992a) investigated the Euler stability of the lumbar spine using a lumped parameter model consisting of five (rigid) vertebral bodies connected by pin joints and torsional springs. The loading was applied vertically at L1. The model predicted buckling loads similar to the ones reported by Lucas and Bresler (1961). Both the predicted and the measured buckling loads of Crisco and Panjabi (1992a,b) are far below the load levels seen in vivo.
In our model, the loads were applied at each joint instead of at L1 only. Also, the direction of the applied loads depended upon the deformation. The direction of the load at one joint was proportional to the angular displacement of the segment below it. That is, the loads did not exactly follow the direction of the tangent to the deformed curve. This allowed us to assess the stability of the model spine when it was subjected to an “imperfect” follower load. An interesting feature of the problem was that it required only a static analysis.
The results of the study demonstrated the sensitivity of the buckling load to the “misalignment” of the follower path. As the direction of the loads approach the follower path, the buckling load increases beyond the Euler critical load. This was not an unexpected result. The increased buckling load predicted in this analysis was consistent with the experimental observations of Patwardhan, et al. (1998).
However, there was a surprising result. The analysis showed that there is a mechanism for a smooth transition between the buckled shapes which is not seen in the classical Euler analysis (Timoshenko, 1961).
These results may have implications for how imperfections in muscle coactivation can affect the stability of the lumbar spine. Also, they may help explain some of the phenomena seen in progression of diseases of the spine such as scoliosis.
In Vitro Quasi-Static and Cyclic Biomechanics of a Cervical Spine Posterior Plate Versus Facet Wiring in a Laminectomy Model
Authors: Scifert Jeffrey L. , Goel Vijay K. , Smith Darin W. , Traynelis Vincent C. 
Published: January 2022

Abstract
Stability comparisons of cervical facet wiring and posterior cervical plating in a quasi-static and cyclic environment contain important clinical ramifications and this research addresses this issue. Decreases in motion at C4-C5 after undergoing bilateral laminectomy and subsequent stabilization indicated that plate decreases in motion were markedly higher than facet wiring decreases in all cases except cyclic extension. Posterior plates were superior in almost every loading mode tested, including the cyclic mode. The stabilized and cyclic results were only similar in extension between plates and wires. Screw torque decreases between pre- and post-fatigue plate measurements did not appear to affect specimen stability. Posterior plates appear to be biomechanically superior to facet wiring in cervical spine stabilization following laminectomy.
Temperature-Dependent Viscoelastic Properties of the Supraspinatus Tendon
Authors: Huang Chun-Yuh , Wang Vincent M. , Roh Michael S. , Pawluk Robert J. , Flatow Evan L. , Mow Van C. 
Published: January 2022

Abstract
The relevance of studying the temperature-dependence of ligament and tendon mechanical properties has been well documented [4,8,12,15]. While investigations of tendon and ligament mechanics are typically performed at controlled in-vitro temperatures (e.g., room temperature), these conditions clearly are different from those in vivo. Results from the various investigations have not been consistent. For instance. Rigby et al. [12] found no significant differences in the mechanical properties of rat tail tendon between 0°C and 37°C, while Woo and coworkers [15] reported significantly increased cyclic load relaxation and decreased tensile load with increasing temperature from 2°C to 37°C. A more recent study by Lam et al. [8] showed that in rabbit ligaments the temperature effects are minimal in shorter duration tension tests (i.e., more elastic-dominated) but readily apparent in a more viscous-dominated test such as creep or stress relaxation.
Application of a Special Theory of Biphasic Mixtures to Annulus Fibrosus
Authors: Klisch Stephen M. , Lotz Jeffrey C. 
Published: January 2022

Abstract
We applied a special theory of an incompressible mixture of an elastic solid and an inviscid fluid to experimental data (Iatridis et al., 1995) for axial confined compression of annulus fibrosus in finite deformation. We found that this special theory demands a significantly different nonlinear permeability function than the widely used theory of Kwan et al. (1990) and Holmes and Mow (1990) to achieve a best-fit regression to the surface stress time history.
Wear of Retrieved CoCrMo Articulating Surfaces in Total Hip Arthroplasty
Authors: Scott Marcus L. , Eberhardt Alan W. , Lemons Jack E. 
Published: January 2022

Abstract
Wear particle-induced osteolysis is widely regarded as the leading long-term complication associated with total hip arthroplasty (THA) [1]. The need to reduce or eliminate UHMWPE debris has led to renewed interest in alternatives to the current metal-UHMWPE bearing couple, including a reevaluation of metal-on-metal designs. Previous analyses of both simulator-tested and retrieved metal-on-metal THA articulating components have shown that wear rates tend to decrease with a longer time in situ [2,3]. This phenomenon may result from an initial period of accelerated “run-in” wear, in which there is a partial removal of surface asperities and a correction of implant asphericity. This may lead to enhanced fluid film lubrication at the articulation interface and ultimately reduce long-term wear rates of the bearing components. The objectives of this study were to quantify the wear rates of a series of explanted Sivash metal-on-metal bearing components and to characterize changes in surface geometry configurations in order to better understand the running-in phenomenon associated with metal-on-metal bearing surfaces.
Biomechanics of Vestibular Hair Cell Bundles
Authors: Cotton John R. , Grant J. Wallace 
Published: January 2022

Abstract
Hair cells are transducers present in the inner-ear of vertebrates. They convert a mechanical signal into a neurochemical one and are the first cellular component of both vestibular and auditory systems. The mechanical sensor of the hair cell is the ciliary bundle which projects into an extracellular space where it receives an external force either by fluid flow or the displacement of a nearby structure to which the bundle is attached.
A Child’s Hand With Self-Energizing Grasp
Authors: Landsberger Samuel , Shaperman Julie , Lin Andrew , Vargas Vicente , Fite Richard , Setoguchi Yoshio , McNeal Donald 
Published: January 2022

Abstract
Parents of children with upper-extremity limb deficiencies, and clinicians, have long expressed the need for a better body-powered hand. Our objective is to develop an improved hand and activation system for toddlers between the ages of one and four. The primary design goals are: (i) acceptable cosmesis (hand-like appearance), (ii) useful grasp function for play activities, and (iii) minimal requirements for harness force and motion inputs from the child.
The approach has been to explore several hand design strategies in parallel with different methods of harnessing the child’s considerable energies and, where these fall short, provide robust means of amplifying the child’s energy output.
A simple hand called “Easy Feed” shows promise in both grasp capability and suitability to a toddler’s cognitive and physical development. We are investigating coverings for the structure alongside design of the hand’s mechanical linkage. Force and Power augmentation modules in development will assist children with less strength.
The Effect of Cement Thickness & Surface Roughness on the Strength of the Metal-Cement Interface
Authors: Gruen Thomas A. , Shockley Darryl , Norman Timothy L. 
Published: January 2022

Abstract
Acrylic bone cement is commonly used to affix metallic femoral hip implants within the proximal femur during hip arthroplasty. Previous studies indicate that the expected life of a cemented implant may depend on the integrity of the metal-cement interface and that the interface strength can be influenced by many factors such as variable cement technique, surface roughness of the metal implant, or using pre-coated implants. To this date, there is no study, as far as is known, on the effect of cement thickness on the integrity of the metal-cement interface. The purpose of this study was to determine whether different cement mantle thickness affected the mechanical integrity of the metal-cement interface. Two different surface roughness of commercially manufactured Co-Cr cylindrical implants were cemented into plastic cylindrical molds simulating the femoral intramedullary cavity. Post-cured specimens were evaluated under four test conditions including 24-hours stored dry at room temperature (rt), 3-months dry (rt) storage, and 3-months immersion in physiological saline solution (rt) or at body temperature (bt). Parametric analysis of the metal-cement interface, measured with the push-out test method, indicated that all grit-blasted implants regardless of cement thickness and test conditions had mean interface strength values of approximately 5 MPa. With the polished implants and thick cement mantle (i.e. 6.3 mm) the mean interface strength was an order of magnitude lower, i.e. ≈ 0.5 MPa, and was significantly reduced after 30 days of immersion. For the polished implants with thin cement mantle (i.e. 2.4 mm) the mean interface strength values were approximately 0.1 MPa for all test conditions. In summary, in this study the metal-cement interface bond was maintained with grit-blasted surfaced implants under the different test conditions; however, debonding of polished surfaced implants with thick cement mantle was sensitive to test conditions and that debonding was readily obtained with the thin cement mantle. It is concluded that thin cement mantles around metallic femoral stems may result in earlier debonding at the metal-cement interface thereby increasing the risk of early failure of a cemented implant system with cylindrical stems.
Wear-Resistant Properties of Newly 3-D Orientated UHMWPE for Artificial Joints
Authors: Ohta Makoto , Hyon Suong-Hyu , Oka Masanori , Tsutsumi Sadami 
Published: January 2022

Abstract
UHMWPE was crystallized under molecular orientation in order to improve the wear resistant properties against Co-Cr-Mo alloys, since these two materials are used for artificial joints. We measured weight loss of UHMPWE by using a pin-on-flat reciprocating type wear machine. It was confirmed that, when the sample was compressed in the molten state, wear resistant properties of UHMWPE increased greatly with increasing degree of compression.
An EMG-Driven Musculoskeletal Model for Estimation of Human Joint Moments During Isometric Time-Varying Loads
Authors: Buchanan Thomas S. , Cheng Jian-Yu , Shen Xiaofeng , Manal Kurt 
Published: January 2022

Abstract
The purpose of this work was to develop a robust EMG-driven elbow model to estimate muscle forces and joint torques of different people performing different time-varying loads at the elbow. The model consisted of an anatomical model, an EMG-to-activation model, a Hill-type muscle model, and a nonlinear optimizer. All of the major muscles about the elbow were taken into account. The parameters used by the muscle model were optimal fiber length, maximum contraction velocity, pennation angle, tendon slack length, and maximum muscle force. EMG and joint angle were input variables. Moment arm and muscle length varied as a function of joint angle, as defined in the anatomical model. The model was used to examine the importance of accounting for muscle velocity during rapid loads applied at fixed joint angles.
Reoxygenation in Tumor Tissues After X-Ray or Carbon-12 Irradiation
Authors: Fukawa Takeshi , Takematsu Koji , Oka Kotaro , Miyahara Nobuyuki , Koike Sachiko , Ando Koichi , Kobayashi Hirosuke , Tanishita Kazuo 
Published: January 2022

Abstract
We measured directly the partial pressure of oxygen (pO2) in new fibrosarcoma (NFSa) tumors grown in C3H/He mice using microcoaxial O2 electrodes in vivo. The pO2 in tumors was monitored after a single dose of X-ray or carbon-12 irradiation. After irradiation, tumor volume temporally shrinked, and pO2 simultaneously increased. Carbon-12 irradiation reoxygenated tumors between the 1st and 9th day after the irradiation, while x-ray irradiation reoxygenated tumors between the 3rd and 8th day. We found that reoxygenation period after carbon-12 irradiation started earlier and continued longer than X-ray irradiation.
Scientific Characterization of the Rincoe Socket and Tekscan F-Socket Interface Pressure Measurement Systems: Implications for Clinical Utility
Authors: Polliack Adrian A. , Landsberger Samuel , McNeal Donald R. , Craig Dana , Sieh Robert , Ayyappa Edmund 
Published: January 2022

Abstract
Socket fabrication is a highly refined art that relies on the skill and experience of the prosthetist. Despite best efforts, patients often return to the prosthetist with complaints of residual limb pain, socket discomfort and skin problems. To prevent problems such as these and resolve problems that have developed, the prosthetist relies primarily on verbal feedback from the patient and visual inspection of the residual limb. Clinical techniques for the quantification of biomechanical factors at the socket interface are not in common use. Specifically, the two commercially available interface pressure measurement systems, the Rincoe Socket Sensor and the Tekscan F-Socket Measurement Systems, are not employed by many prosthetists. This is perhaps due to cost, difficulty in clinical interpretation of the data, and time required for operation.1 Furthermore, these systems have not undergone any scientific evaluation for validity.
Mechanical Model for Myocardial Trabeculation
Authors: Taber Larry A. 
Published: January 2022

Abstract
Trabeculation of the embryonic heart is studied using a biomechanical model for epithelial morphogenesis. The analysis of the model includes large deformation and cytoskeletal activation. Illustrative results for a membrane on an elastic foundation (substrate) illustrate the pattern-forming capability of the model, with concentrations in membrane thickness representing trabeculae.
Prediction of Glide Avalanche Based on Composite Roughness
Authors: Suzuki Shoji 
Published: January 2022

Abstract
Surface topography of a magnetic disk is one of the key parameters to determine safe fly height in a hard disk drive. In order to quantify the flying capability of the disk surface, glide avalanche is a useful parameter because it is the parameter which indicates the height of the surface topography from the mean surface below which a head can not fly without contacts. The avalanche is regarded as the floor of the disk surface intrinsically defined by the surface finish during disk production. The glide height is set at higher level than the avalanche and usually limited by isolated defects or contamination on the surface. Because of this direct couple between glide avalanche and the disk surface finish, the measurement and prediction of the glide avalanche are very important. In this paper, we discuss the importance of fly height characterization of a glide head and the relationship between disk surface topography and its avalanche. We propose a simple yet versatile model based on a composite roughness, which can be applied to a polished surface and to a textured contact start/stop zone including laser bumps.
Natural Frequency Analysis of PZT Glide Heads During Contact
Authors: Tsay Alex Y. , Ku C.-P. Roger , Shen I. Y. Steve , Marchon Bruno 
Published: January 2022

Abstract
The natural frequencies (NFs) and the corresponding mode shapes of a glide head with a piezoelectric transducer (PZT) mounted on its extended wing have been studied both analytically and experimentally. Finite element analysis results indicate that the extended wing reduces the NFs of the glide head substantially. The manufacturing tolerances of the slider and PZT as well as the PZT bonding location can have a significant effect on the NFs. As the glide head contacts the laser bump texture during the landing process, the NFs of the glide head increase slightly, probably because of the constraint provided by the stiffness of the bumps during the contact. The NFs calculated by finite element analysis show good agreement with the data obtained using two different experimental methods.
Mixed Finite Element Solution for a Magnetostatic Inverse Problem
Authors: Shigeta Takemi 
Published: January 2022

Abstract
The purpose of this paper is to present a numerical method of solution for a two-dimensional magnetostatic problem. The normal component of the magnetic flux density and the tangential component of the magnetic field with errors are simultaneously imposed on a part of the boundary of a bounded domain of the problem. The problem can be regarded as a boundary value inverse problem, because the proper boundary condition is to be identified for the rest of the boundary. The treatment is based on the method of least squares, and the steepest descent method minimizes an objective functional with a regularization term. The direct variational method paraphrases the inverse problem to the primary and the adjoint boundary value problems. The mixed finite element method using the edge element and the conventional finite element method are applied to the numerical solutions of the boundary value problems. Based on numerical computations, it is concluded that an estimated solution for the boundary data without errors is in agreement with an exact one, and the regularization term yields good approximate solutions for the boundary data with errors.
Experimental Spatial Matrix Identification as a Practical Inverse Problem in Mechanics
Authors: Okuma Masaaki , Oho Tatsuya 
Published: January 2022

Abstract
This paper presents a method for identifying a set of spatial matrices, which are the coefficient matrices of equations of motion for mechanical structures in the physical domain. The input data for the method are a set of frequency response functions measured experimentally within a limited frequency range of interest and the coordinate data of measurement points. This is a practical engineering inverse problem. The definition of the inverse problem and the method developed are presented in this paper. In addition, a simple example is shown to demonstrate its practical validity and usefulness.
An Interactive Learning Tool for Dynamic Systems and Control
Authors: Lee Kok-Meng , Daley Wayne , McKlin Tom 
Published: January 2022

Abstract
Although there are many stimulating and practical applications for system dynamics and automatic control, students often find the material too abstract, too mathematical, and difficult to master when it is presented in lectures. The difficulties experienced by students in learning system dynamics and controls include the following: (1) Dynamic and control systems are interdisclipinary in nature and require complex mathematical expressions that were taught in previous courses. (2) Computer simulation and hands-on experiments are necessary in order for the students to fully appreciate the basic concepts of automatic control. (3) Lecture hours are insufficient to provide both the theory and real-world applications of system modeling and automatic control. In order to overcome these problems, an interactive multimedia software tool that allows the students to explore the design space was developed. We discuss here the role of technology as it can be applied in teaching system dynamics and control. The primary goal of this work is to build a tool that assists students in learning system dynamics and control by providing a link between control system design (CSD) theory and laboratory learning. Specifically, the materials developed provide support in three different forms of instruction; labs, lectures and homework.
Anticipating Dynamic Loads in Handling Objects
Authors: Wing Alan M. , Flanagan J. Randall 
Published: January 2022

Abstract
In this paper we review a set of studies showing that when people pick up and move an object they continually adjust their grip force in order to stabilize the object in the hand. These grip force adjustments occur simultaneously with or slightly ahead of fluctuations in load forces and torques related to moving the object. They may therefore be seen as anticipatory and we argue that a key line of research in manipulation should be to understand the integration of sensory motor information to build an internal model of the object and the effector system to support such anticipation.