bluuebunny/crossref_metadata_2025_split huggingface dataset:
Computational Biomechanics of Artificial Ligament and Tendons: A Finite Element Analysis
Authors: Chu Tai-Ming , Sokol Mroslaw 
Published: July 2023

Abstract
Reconstruction of the Anterior Cruciate Ligament (ACL) has been a major focus in sports medicine over twenty years. Severe or un-repairable damage of the ACL due to sport injury is a major problem faced by orthopedic surgeons and engineers. In order to replace or reconstruct an injured ACL, the mechanical properties as well as the dimensional limitation of the material used must be similar to the biological ligaments. Although excessive literature describes experimental investigation on the mechanical property and clinical application of the ligament material, there are little analytical studies that describe strains, stresses, and endurance in the bone/ligament/bone complex. The Finite Element Analysis (FEA) is a method to study this problem. The objectives of the present investigation are (1) developing a finite element model (FEM) of an artificial ligament yarn, the emphasis is put on the development of the elastic FEM, and (2) analyzing stress distribution in the ligament yarn fibers due to various loading conditions and design parameters. Results obtained from the FEM of the ACL prosthesis yarn are confirmed by experimental measurements using tensile test.
Physical Properties of a New Orthopaedic Supporting Material for Posture Control in Chairs and Beds
Authors: Chang J. K. L. , Lao M. T. , Tao X. M. 
Published: July 2023

Abstract
The prevalence of back discomfort has prompted the search for better orthopaedic supporting material in chairs and beds. A new warp-knit fabric has been developed to provide orthopaedic sleeping support without using traditional box-spring or spring-in-mattress devices. Described in an US patent [1] by one of the authors, J.K.L. Chang, the fabric is warp knitted with a lock-knit stitch with a laid-in yarn, using three guide bars with nylon and elastic yarns. As shown in Figure 1, if a pressure is exerted on any single loop which is only 0.5 mm2 in area, the pressure will be passed to the 11 neighbouring yarns, then further propagated via other adjacent yarns to a much larger area.
This fabric has also been used in chairs. The fabric is stretched over the frame of a chair under different tensions along the length of the chair body so that it gives a contour fit to the person’s body, and put tension on the lumbar and raise the knee higher than the buttock to put the person in a good sitting posture.
A clinic trial has been carried out involving three nursing homes, two institutions and eight individuals in USA. It has been observed that the fabric structure and this mechanism of “de-localising pressure” make people, sitting or sleeping on this supporting system, feel comfortable, with reduced pain and reduced chance of getting back sores.
Experiments are being conducted in order to study relevant physical properties of the fabric related to the results of the clinical trial. Results from these tests will be presented including static and dynamic tensile properties, bending, shear, lateral compression and surface properties, air-permeability, thermal properties and flammability of the fabric. Comparison will be made between the supporting system made from the fabric and that from artificial leather/foam system.
A prototype chair will be demonstrated during the conference.
Fatigue Failure Prediction in the Polyethylene Component of a Total Knee Replacement Based on Cyclic Rolling
Authors: Natarajan R. N. , Andriacchi T. P. , Beard B. J. , Amirouche F. M. L. 
Published: July 2023

Abstract
As the knee flexes, the contact moves from anterior to posterior position. This process involves the initiation and stopping of rolling. As a result, tractive forces are generated at the tibio-femoral articulation (1). While several studies have addressed the issue of a cyclically moving load (2,3), the effect of the tractive rolling force on stresses in polyethylene was not studied.
The Role of Proteoglycans in the Frictional Properties and Normal Stress Effect of Articular Cartilage
Authors: Wang L. H. , Ateshian G. A. , Saed-Nejad F. , Ratcliffe A. 
Published: July 2023

Abstract
Articular cartilage, comprising the sliding surfaces of diarthrodial joint, produces very low friction coefficients and has excellent wear properties. Understanding the lubrication of diarthrodial joints has been an important objective in the field of biomechanics since the early part of this century. But not until the 60s has the role of cartilage in joint lubrication been specifically investigated in parallel with the development of cartilage mechanics. The role of cartilage in joint lubrication includes the time, velocity, and load dependence of cartilage friction (McCutchen, 1962; Malcom 1967; Wright and Dowson, 1967); furthermore, in our own recent investigations, it has been observed that cartilage exhibits a very significant normal stress effect under steady frictional shear (Wang and Ateshian, 1995). Furthermore, it was observed that the normal stress effect persists even after removal of the surface zone (Wang and Ateshian, 1996), demonstrating that this effect is attributable to intrinsic properties of the cartilage rather than a boundary lubricant adsorbed to the surface. Following these studies, it was hypothesized that the normal stress effect is related to the proteoglycans present in the tissue, since Theological studies of proteoglycan solutions (Zhu et al., 1991) have been shown to exhibit a normal stress under steady shear; hence it is possible that proteoglycans in the tissue matrix impart to the interstitial fluid a non-Newtonian behavior which is responsible for the observed normal stresses. Therefore, the goal of this study was to determine the effect of specific removal of glycosaminoglycan chains on the normal stress.
Rolling Resistance of Articular Cartilage due to Interstitial Fluid Flow
Authors: Ateshian Gerard A. , Wang Huiqun 
Published: July 2023

Abstract
The typical frictional coefficients reported for articular cartilage are in the range of 0.002–0.15 or greater [1,2,3]. The excellent lubrication and wear characteristics of cartilage have been attributed to various mechanisms which consider the interfacial shear stress that arises at the surfaces of articulating cartilage layers to be the primary mechanism of friction in joints. A secondary mechanism which may contribute to the frictional coefficient of joints is the rolling resistance due to the hysteretic energy loss of viscoelastic cartilage, as has been shown for engineering bearings made of viscoelastic materials [4,5]. In cartilage, the primary viscoelastic response of the tissue is believed to be caused by the flow of interstitial fluid relative to the solid phase [6].
Effect of Component Placement on the Patellofemoral Joint After Total Knee Arthroplasty
Authors: Zhang Anna X. , Miller Mark C. , Berger Richard A. , Sherwood Christopher P. , Petrella Anthony J. , Rubash Harry E. 
Published: July 2023

Abstract
Seven human cadaveric specimens were tested on a knee simulator to study the effect of femoral component external rotation and patellar component medialization on the patellofemoral joint after total knee arthroplasty. The femoral component was externally rotated by 0°, 2.5°, and 5°, and the patellar component was positioned at the geometric center and 3.7mm medial to the geometric center. Only one of the specimens subluxed. Medialization of the patellar component was found to decrease the lateral force on the patella and increase the lateral tilt of the patella. The external rotation of the femoral component had a complicated interaction with the patella, and the overall effect was less obvious. Neither the femoral component rotation nor the patellar component medialization had a large effect on the normal patellofemoral forces.
Effects of Arterial Hemodynamics and Cyclic Strain on Platelet Deposition to Human Saphenous Vein Segments Perfused Ex-Vivo
Authors: Severyn Donald A. , Muluk Satish C. , Vorp David A. 
Published: July 2023

Abstract
The greater saphenous vein, extending from the ankle to the groin along the medial side of either leg, is commonly used as a bypass conduit to reroute blood around blockages in both the coronary and peripheral arterial systems. Unfortunately, saphenous vein grafts often fail requiring re-operation. For example, one review found failure in 8–30% of the coronary artery vein grafts 30 days following surgery (von Segesser, 1990). While intimal hyperplasia accounts for the majority of long-term failures, occlusion of the bypass grafts during the first month is primarily due to thrombosis (Cox et al., 1991).
A Transient Three-Dimensional Model of Micro Heat Pipes Used As an Integral Part of Semiconductor Devices
Authors: Huang X. Y. , Liu C. Y. , Toh K. C. 
Published: July 2023

Abstract
An analytical model is presented in this paper to simulate the transient temperature changes on a semiconductor device integrated with an array of micro heat pipes in response to the switch-on of a heat source inside the device. Effect of the embedded micro heat pipes is taken into account by assuming that the silicon wafer has a higher thermal conductivity in the direction of the heat pipe array than that in other two directions. Analytical solutions are obtained for various combinations of the heat sources and sinks, and a good agreement is shown by comparing the present solutions with the numerical results in the published paper.
Infrared Imaging Using Microcantilevers
Authors: Oden Patrick I. , Datskos Panos G. , Thundat Thomas G. , Wachter Eric A. , Warmack Robert J. 
Published: July 2023

Abstract
A micromechanical detector using microcantilever for infrared (IR) radiation is demonstrated. Because of their small size and low thermal mass, these microcantilever IR detectors are promising new family of IR sensors. This novel IR sensor is based on deflection due to IR adsorption induced thermal stress on a bimaterial cantilever which can be monitored with several methods such as optical deflection or piezoresistive. When laser-deflection-monitored Si4N4 microcantilevers coated with a 40nm thick coating of gold were irradiated by a low-power diode laser, the noise equivalent power and specific detectivity, NEP and D* were found to be 173pW/Hz and 7.18 × 108cmHz/W, respectively, when compensation for the laser reflectivity was made.
Computation of Supersonic Flow for Thin Film Deposition Using Expansion Through a Skimmer
Authors: Boyd Iain D. , Chen Gang 
Published: July 2023

Abstract
Deposition of silicon films through seeding of disilane molecules in a supersonic beam of molecular hydrogen is modeled using the direct simulation Monte Carlo technique. In this process, the beam is formed by rapid expansion of the heated gas through an orifice of diameter 250 μm and then through a skimmer. Application of the numerical method to model the gas dynamics of this process is discussed with reference to a number of simulation issues. Description is made of a parallelized implementation of the Monte Carlo method that enables computation of these geometrically complex, nonequilibrium flows. Results are presented for a representative system configuration. General features of the flow field are described. Detailed information is provided by the simulations on the properties of the disilane molecules as they impact at hyperthermal energies on the substrate surface. Comparison of the numerical results with available experimental data reveals good agreement offering the potential to optimize the deposition process using the Monte Carlo method as a design tool.
Flow Behavior Through Microfluidic Valves
Authors: Jiang X. N. , Zhou Z. Y. , Li Y. , Yang Y. , Ye X. Y. 
Published: July 2023

Abstract
Microvalves are the important components in the microfluid control systems. The flow behavior through two major types of silicon microvalves, with and without moving parts inside, were discussed in this paper. The silicon valves with different flexible flaps and the silicon nozzle/diffuser elements were designed and fabricated for the experimental research. The regression curve of the measurement results of the micro flap valve with the out port size of 200 × 200μm agree with the theoretical analytical model well. The flow coefficients through silicon nozzle/diffuser elements with the conical angle in width of 5°, 7.5° and 10° and the length of 3 mm as well as the relation between the flow resistance ratio of nozzle to diffuser and the geometric parameters were obtained.
The Impact of Design and Fabrication on the Dynamic Behavior of a Micro-Turbine
Authors: Wiegele Thomas G. 
Published: July 2023

Abstract
Four different micro-turbine designs were fabricated using the LIGA process in conjunction with a hermetic sealing operation. Each was characterized in terms of start-up velocity, operating velocity, peak velocity, efficiency and orientation by varying flowrates and pressures while measuring the angular velocity of the rotor. Measured data indicated that the distance between the rotor and the cover was the most significant determinant of performance. Design factors, such as turbine blade shape and stator design, were also significant.
Application of B.E.M. to Predict the Efficiency of Two Micro-Machines With Rigid Tails
Authors: Nasseri S. , Phan-Thien N. 
Published: July 2023

Abstract
This paper reports on the results of investigation of the swimming of two different micro-machines. Mechanically each of these micro-machines consists of a head (containing an electromechanical power source) and a tail which moves relative to the head as a rigid body. The problem is approached theoretically by considering the types of movement which can occur for these micro-machines immersed in a viscous medium. The first micro-machine has a tail which oscillates in vertical plane, therefore the trajectory of this machine is in that plane too. The tail of the second micro-machine rotates conically, so it produces a three dimensional helical path in space with its axis approximately along the direction of tail centreline.
Using the boundary element method for solving the traction equations on the surface of the tail, and a time dependent Euler kinematic scheme to plot the path, the translational velocity, angular velocity and the trajectory of each machine are calculated. Evaluation of the path and the direction of motion for each micro-machine using different dimensional parameters can give an idea of the efficiency for such machines with rigid tails.
Micromanipulation Using Distributed Electromagnetic Actuators
Authors: Inoue Tadanobu , Hamasaki Yukio , Shimoyama Isao , Miura Hirofumi 
Published: July 2023

Abstract
A method of micromanipulation using a microcoil array is proposed. Active coils drive permanent magnets on a work platform. The magnets can push mechanical parts to perform 2-dimensional assembly. Three-dimensional operation may be achieved from 2D magnet motion when the permanent magnets are parts of a closed loop spatial linkage. Manipulation on a 4 cm × 4 cm coil array was tested, and based on this large scale experiment, we fabricated a microcoil array using IC-based processes. A 4 × 4 microcoil array with 8 turns per coil was fabricated. The chip area, including bonding pads, is 3.6 mm × 3.6 mm. The minimum current necessary to attract a magnet and its speed were measured. A 0.6 mm × 0.6 mm × 0.3 mm magnet was found to move at 79 mm/s. The top speed for a magnet to follow a square trajectory was also measured. It was demonstrated that a 1.1 mg magnet could push a 13.4 mg object out of the microcoil array.
Membrane Micromotors Based on Piezoelectric Properties of PVDF Polymer Films
Authors: Jian Zhang , Shen De Xin , Wang Wei Yuan 
Published: July 2023

Abstract
A new type of micromotors, which employed piezoelectric polymer films, polyvinylidence fluoride (PVDF), had been fabricated. The polymer films with thickness 45μm, poling along thickness direction had been used with piezoelectric constant d33 = 19 to 22pcN−1. Aluminum had been evaporated on both faces of the films as electrode plates. The stators were formed by bonding PVDF films to brass diaphragms. The diaphragm thickness was 300μm. The upper-electrode pattern was formed by wet etching. The excitation principle of piezoelectric ultrasonic micromotors was discussed and the vibrational modes existing in stators were analysed in order to design the stators reasonably. A prototype micromotor was obtained by using small tin balls as rotors. Applied voltage 10V. the maximum value of rotation speed was about 14rpm. According to Hertz contact theory, the maximum pressure which the loads pressed on the vibrators had been calculated and compared with the experimental results. The difference of the rotation speed was contributed to the difference of the pressure. Additionally, a 100 hours continuous test showed that the characteristics of the micromotors had no obvious drop.
Measurement of Mechanical Properties of Electroplated Nickel-Iron Alloys
Authors: Chung Charles C. , Allen Mark G. 
Published: July 2023

Abstract
Electroplated materials often have mechanical properties that differ from their bulk counterparts. A microfabricated test device has been made to measure the Young’s and shear modulus of electroplated 80/20 nickel-iron (NiFe) in-situ for micro-electromechanical devices. The effective Young’s modulus was calculated to be E = 65GPa, which differs substantially from bulk NiFe with a E = 210GPa. The shear modulus was found to be G = 44GPa ± 15GPa which differs from the bulk shear modulus G = 80GPa.
A Viscoelastic Continuum Damage Model for Polymeric Composites
Authors: Abdel-Tawab Khaled I. , Weitsman Y. Jack 
Published: July 2023

Abstract
A comprehensive thermodynamic framework is proposed for modeling the behavior of polymeric composites exhibiting viscoelasticity, damage and permanent deformation. In the present formulation, the total strain is decomposed into viscoelastic and permanent components. The effect of damage on the constitutive behavior is introduced through direct coupling between damage and the internal state variables representing deformation of the undamaged (virgin) material. This approach accounts for time-dependent damage as well as damage-induced changes in material symmetry. The proposed constitutive model is applied to experimental data for swirl-mat polymeric composites.
Evaluation of Fracture Processes in Cement-Based Materials Under Compression Using Computer Vision
Authors: Choi Sokhwan , Shah Surendra P. 
Published: July 2023

Abstract
The heterogeneous nature of concrete requires a robust deformation measuring method to obtain a reliable information about the failure process of concrete. A non-destructive displacement evaluation system utilizing a image correlation scheme, often called computer vision, is developed to examined fracture process in cement-based materials. The technique is a full-field measuring method which gives an accuracy within the micron range. Displacement arrow diagrams or displacement contour maps reveal highly nonuniform deformations even at the early loading stages. The laboratory study shows that the technique has a potential for field application.
Stress-Strain Relationships of Open-Cell Foams
Authors: Todd Beth A. , Smith S. Leeann , Bunn Tera S. 
Published: July 2023

Abstract
Open-cell foams provide cushioning and precise positioning in medical applications. To design cushions and supporting surfaces with these types of foams, a thorough understanding of the foam material properties, such as the elastic tangent modulus, is needed. While these foam materials do not have the same type of stress-strain relationship as more traditional engineering materials, this relationship can be determined.
Four types of foam material were tested according to the ASTM D-3574-91, “Standard Methods of Testing Flexible Cellular Materials-Slab, Bonded and Molded Urethane Foams”. The variation in stiffness among the materials was approximately an order of magnitude.
The stress-strain relationships for all of the materials began with a linear region at small strains followed by a non-linear region at higher strains. The polyurethane materials also contained a linear transitional region which exhibited a reduced stiffness. The effect of applying a liquid proof coating to the foam was also investigated.
Recurrent group B streptococcus infection in an extremely premature infant: as a preterm neonate, infant and toddler
Authors: Schim van der Loeff Ina , Tsilifis Christo , Abdelhafiz Khalid , Williams Eleri J 
Published: July 2023

We report five discrete episodes of group B streptococcus (GBS) bacteraemia in an extremely premature infant, extending into early childhood. The first four episodes occurred during infancy despite appropriate treatment. Breastmilk was positive for group B streptococcal 16S DNA by polymerase chain reaction. The fifth episode occurred at 17 months of age, shortly after stopping antimicrobial prophylaxis.Radiological investigations did not identify a focus for recurrence of GBS bacteraemia, and immunological investigations and targeted whole genome sequencing yielded only transient hypogammaglobulinaemia of infancy, which resolved.This case highlights invasive GBS infection as a cause of infant morbidity. Premature infants are at particular risk of invasive as well as recurrent disease. GBS is typically a sensitive organism and each episode of GBS in our patient was effectively treated with penicillin. The role of breastmilk in recurrent GBS is controversial; in this case infant and mother isolated identical GBS serotypes and were concurrently treated with rifampicin.
Provider care segregation and hospital-region racial disparities for carotid interventions in the USA
Authors: Daniel David , Maillie Luke , Dhamoon Mandip 
Published: July 2023

BackgroundReasons for racial disparities in the utilization and outcomes of carotid interventions (carotid endarterectomy (CEA) and carotid artery stenting (CAS)) are not well understood, especially segregation of care associated with carotid intervention. We examined patterns of geographic and provider care segregation in carotid interventions and outcomes.MethodWe used de-identified Medicare datasets to identify CEA and CAS interventions between January 1, 2016 and December 31, 2019 using validated ICD-10 codes. For patients who underwent carotid intervention, we calculated (1) the proportion of White patients at the hospital, (2) the proportional difference in the proportion of White patients between hospital patients and the county, and (3) provider care segregation by the dissimilarity index for carotid intervention cases. We examined associations between measures of segregation and outcomes.ResultsDespite higher proportions of Black patients in counties with hospitals that provide carotid intervention, lower proportions of Black patients received intervention. The difference in the proportion of White patients comparing CEA patients to the county race distribution was 0.143 (SD 0.297) at the hospital level (for CAS, 0.174 (0.315)). The dissimilarity index for CEA providers was high, with mean (SD) 0.387 (0.274) averaged across all hospitals and higher among CAS providers at 0.472 (0.288). Black patients receiving CEA and CAS (compared with Whites) had reduced odds of discharge home. Better outcomes (inpatient mortality and 30-day mortality) were independently associated with higher proportion of White CAS patients.ConclusionIn this national study with contemporary data on carotid intervention, we found evidence for segregation of care of both CEA and CAS.