bluuebunny/crossref_metadata_2025_split huggingface dataset:
Elastic Response of a Submerged Plate Coated With Multiple Layers of Elastomeric Materials in the Presence of a Turbulent Boundary Layer
Authors: Mendoza Jeff M. , Pham Hoang 
Published: December 2021

Abstract
This study addresses the elastic response of a submerged plate coated with multiple layers of elastomeric materials. of interest is the extent at which the mechanism of interaction between dissimilar elastomers can be modified through selection of material properties. Such modification can optimize the received signal response at the sensors in the presence of a turbulent boundary layer (TBL) as well as provide insight into advantageous TBL and structure-borne vibration decoupling configurations. The analytical model is an infinite multilayer composite of steel and viscoelastic materials separating the semi-infinite media of water (external) and air (internal). The theory of elasticity expedites the analysis of elastic response, governed by dilatational and shear motion, in each layer. The analysis considers excitation by an incident plane wave in addition to a fully developed TBL both in the water medium. A series of numerical simulations based on material properties of well-characterized elastomers quantify the degree at which this coupling mechanism can be optimized in applications of noise and vibration reduction.
How to Measure the Internal Forces of a Combustion Engine
Authors: Takahashi Yukitaka , Kamimura Naoki , Suzuki Toshibumi , Urakabe Kouji , Suzuki Hideo , Wada Shinji 
Published: December 2021

Abstract
It has become increasingly important to reduce the powertrain vibration which mainly affects the interior noise of vehicle during acceleration. In the past a number of studies were made based on indirect methods including a calculation using measured values of vibration and an identification by means of an FRF. This paper reports on a new direct method for defining the load direction and values obtain from strain gauges attached to each main bearing journal of the powertrain.
A Hybrid Finite Element Method for Calculating the Vibration of Co-Linear Beams in the Mid-Frequency Range
Authors: Zhao Xi , Vlahopoulos Nickolas 
Published: December 2021

Abstract
The theoretical development of a hybrid finite element method is presented. It combines conventional Finite Element Analysis (FEA) with Energy Finite Element Analysis (EFEA) in order to achieve a numerical solution to mid-frequency vibrations. In the mid-frequency range a system is comprised by some members that contain several wavelengths and some members that contain a small number of wavelengths. The former are considered long members and they are modeled by the EFEA. The latter are considered short and they are modeled by the FEA. The new formulation is based on deriving appropriate interface conditions at the joints between sections modeled by the EFEA and the FEA methods. Since the work presented in this paper constitutes a fundamental step in the development of a hybrid method for mid-frequency analysis, the formulation for one flexural degree of freedom in co-linear beams is presented. The excitation is considered to be applied on a long member and the response of the entire system is computed. Uncertainty effects are imposed only on the long members of the system. Validation cases for several configurations are presented.
Basic Analytical Modeling of the Piston Slap in Conjunction With Engine Block Vibration
Authors: Siavoshani Saeed J. , Latcha Michael A. 
Published: December 2021

Abstract
The objective of this research is to enhance and develop analytical and experimental schemes to study the source and path analysis of piston slap noise and to develop tools to relate the piston slap to the engine block vibration. These computer tools solve the piston dynamics and the engine block vibration. The results of this approach are block vibrations that are comparable to experimental results. This study resulted in an analytical approach to understand the piston dynamics in conjunction with block vibration. The engine block vibration was obtained using both a coupled and uncoupled approach due to the piston slap. The coupled approach was to solve the piston motion along with the flexible motion of the cylinder bore which yields the cylinder block vibration directly. The uncoupled approach consists of solving for the contact forces with the simple cylinder model; then using those forces in an FEA analysis of the engine block to determine the resulting vibration.
Shape Optimization of Isotropic Composite Beams Undergoing Harmonic Flexural and Torsional Loading
Authors: Lumsdaine Arnold , Garcia Arnoldo , Yao Ying 
Published: December 2021

Abstract
The purpose of this study is to optimize beams undergoing harmonic excitation in both bending and torsion due to an intermediate mass and inertial component. The objective is to minimize the weight for a composite beam made of glass reinforced acrylonitrile butadiene styrene (ABS), while maintaining performance above a given natural frequency. Design variables are the cross-sectional dimensions. Weight reduction is computed compared to a uniform case. The results are obtained for two different composites with different glass densities, and compared with results obtained with a steel structure.
The structure examined is a clamped-clamped beam with an intermediate mass and inertial component. Basic structures are modeled and optimized analytically. Coupling effects are modeled discretely using finite elements, and these structures are optimized using commercial software. Structures with closed (circular) and open (channel) cross-sections are examined. Results show order of magnitude improvement of optimized structures for both steel and composite beams.
Effects of Low Frequency Induced Excitations on Fluttering Panels in Supersonic Flow
Authors: Surace Giuseppe , Udrescu Radu 
Published: December 2021

Abstract
The paper extends the classical problem of nonlinear panel flutter to the analysis of the effects of external forcing on aerodynamically self-excited thin plates structures of high speed vehicles. This phenomenon can be induced by the aeroeacoustic excitation of noise, boundary layer, or oscillating shock waves. The problem is formulated within nonlinear elastic and linear aerodynamic theories by using a complex finite element model consisting of fifth order plate and second order membrane triangular elements. The excitation is applied harmonically as uniformly distributed pressures. In most cases the pattern of the dynamic response includes a transient period in which the fluttering motion is disturbed into a forced vibration (the steady-state motion) having the same frequency as the excitation. There are also conditions for complex motions having larger amplitudes (than those of the free auto-oscillating system) of both frequencies of flutter and excitation, respectively.
Longitudinal and Out-of-Plane Stiffness of a Web in an Air-Flotation Oven
Authors: Chang Young B. , Swanson Ronald P. , Moretti Peter M. 
Published: December 2021

Abstract
Air-flotation ovens are used for non-contact drying of coated web materials such as photographic film, magnetic media, and paper. In a typical air-flotation oven, the air bars are arranged in such a way that the path of web is nearly sinusoidal. When web tension fluctuates, the distance between the web and the air bars also changes. This phenomenon affects the longitudinal dynamics and tension control of an air-floated web. In some cases, tension fluctuations can cause the web to touch the air bars, resulting in damage to the coating and the web. This paper discusses an analytical model of the extensional resiliency of an air-floated web. The analysis shows that at low tension the longitudinal stiffness of an air-floated web is small, being dominated by the air cushion effects. At higher web tension, however, the effects of material deformation become more important than the air cushion effects. The analysis is compared with the experimental results obtained in a pilot air-flotation oven. The analytical and experimental results show the same trends, though the analytical model tends to underpredict the longitudinal stiffness of air-supported webs.
High-Aspect-Ratio Electroplated Structures With 2μm Beamwidth
Authors: Li Xiaobin , Kiyawat Siddharth , De Los Santos Hector J. , Kim Chang-Jin “CJ” 
Published: December 2021

Abstract
Narrow beamwidth is highly desirable for many micromechanical elements moving parallel to the substrate. A good example is the electrostatically driven flexure structure, whose driving voltage is determined by the width of the beam. This paper presents the process flow and the result of a high-aspect-ratio electroplating process using photoresist (PR) molds. Following a systematic optimization method, PR molds with aspect ratios up to 4.0 were fabricated with a beamwidth of only 2.1μm. Higher aspect ratios, up to 6.8, were achieved using PR double coating technique, with a beamwidth of 2.6μm. Using a Cr/Cu seed layer, nickel electroplating was successfully carried out to translate the PR molds into nickel micro-structures. We observed bend-down of the fully released nickel cantilevers that are over 8μm thick. Further investigation suggested a combined effect of residual stress gradient in the electroplated nickel layer and in-use stiction of the cantilever beams.
EFAB: High Aspect Ratio, Arbitrary 3-D Metal Microstructures Using a Low-Cost Automated Batch Process
Authors: Tseng Fan-Gang , Zhang Gang , Frodis Uri , Cohen Adam , Mansfeld Florian , Will Peter 
Published: December 2021

Abstract
EFAB (“Electrochemical FABrication”) is a new micromachining process utilizing an innovative “Instant Masking” (IM) technique to electrochemically deposit an unlimited number of metal layers for microfabrication. Through this approach, high-aspect-ratio microstructures with arbitrary 3-D geometry can be rapidly and automatically batch-fabricated at low temperature (&lt; 60 °C) using an inexpensive desktop machine. IC-MEMS integration can also be carried out by this low temperature process.
Fabrication of High-Index Refractive Microlenses for Near-Field Optics
Authors: Fletcher D. A. , Crozier K. B. , Kino G. S. , Quate C. F. , Goodson K. E. 
Published: December 2021

Abstract
The minimum spatial resolution of optical systems in the diffraction limit is approximately the free space wavelength divided by twice the numerical aperture (NA) of the system. NA is defined as the product of the index of refraction at the focal point and the sine of the maximum convergence angle of the light. Resolution below the diffraction limit in air can be achieved with a solid immersion lens (SIL) by scanning a sample within the near field of a spot formed in a high refractive-index lens material in the manner of Mansfield and Kino (1990). This paper presents a technique for microfabricating high-NA SILs in silicon with diameters on the order of 10 μm. Silicon has a higher index than previously demonstrated SILs, and it transmits well in the mid-infrared and near-infrared wavelength ranges, making it an ideal choice for high-resolution thermometry and spectroscopy. However, traditional methods for manufacturing SILs are time consuming, labor intensive, and expensive and cannot typically be used to make lenses smaller than 1 mm in diameter. We review current microlens fabrication techniques and describe the fabrication process developed for this work. We include a method for lens formation using acetone vapor to reflow photoresist pillars that can be used to make aspherical as well as spherical lenses. Microlenses etched in single-crystal silicon with diameters on the order of 10 μm and NAs as high as 3.0 are shown. Wafer-scale fabrication offers the opportunity to integrate microlenses onto MEMs structures such as scanning probes for optical imaging, lithography, spectroscopy, and thermometry with high optical efficiency and spatial resolution.
Laser Opto Microactuators Rotated by Molecular Gas Dynamics Effects
Authors: Ota Masahiro , Watanabe Yu-ichi , Sakamoto Moriyoshi 
Published: December 2021

Abstract
In this paper, a selective optical absorber plate and an anodic oxidation alumina are proposed for the rotor of an opto microactuator used as an actuator in a micromachine. The thin films of the selective optical absorber plate are fabricated by vacuum deposition. The substrates used are pyrex glass at the first stage and aluminum at the second stage. Deposition on the pyrex glass substrates is carried out in order to estimate the deposition rate and determine the characteristics of the deposited films. Germanium and silicon oxide are selected as the materials for the selective optical absorber thin films. Germanium is used as to absorb the visible beam from a laser generator. In contrast, silicon oxide is used because it has a small reflectance for visible light. The selective optical absorber-plates for the rotors of the opto microactuator consist of aluminum substrates on which germanium thin films and silicon oxide thin films are deposited. A germanium film is deposited on an aluminum substrate first and then a silicon film is deposited on the germanium film. Therefore, the rotor surface has a small reflectance for visible light and a large reflectance for infrared light. The surface with the deposited films is called the front surface and the opposite surface is called a rear surface. The rear surface is an aluminum plate with the anodic oxidation alumina film for low heat conductivity, large emissivity and thermal insulation. The insulated rotors can keep the temperature difference by greater than 10 Kelvin, even if the irradiation times are longer than 200 seconds. There are 3 reasons why the insulating rotor can keep the temperature difference. They are occurrence of a contact resistance, an increase of a surface area and a small heat conductivity of anodic oxidation alumina.
Suspension Handling System
Authors: Baechi Daniel , Buser Rudolf 
Published: December 2021

Abstract
A new idea of a particle handling system is proposed in this paper consisting of a network of channels and a matrix of mechanical gates for fluids. The device consists of a silicon chip encapsulated by two glass chips. A free standing silicone membrane with a thickness of only two microns is used to reduce the cross sections of the channels. The selected cross section of 30 × 7 μm allows to handle particles with sizes ranging from the sub micron scale to a few microns. We could show that the flow of these particles in the channels can be controlled by actuating the valves and monitored with a video microscope. The density of valves is 600 valves / square inch in our first prototype. The second prototype with a valve density of 100 valves / square inch also includes channels for cooling of the device.
Design of a Chip Based Microanalytical Fluidic System Based on Electrochemical Detection Using Redox Cycling
Authors: Richard Åse , Klett Oliver , Strandman Carola , Bäcklund Ylva , Nyholm Leif 
Published: December 2021

Abstract
Microelectrodes on a chip have been investigated regarding their usefulness for dual electrode amperometric detection in off-chip and on-chip based microanalytical capillary flow systems. In the latter case, microelectrodes were integrated on a chip containing fluidic channels. A straightforward method to micromechanically manufacture the chips is presented. In this process, the microelectrodes are manufactured on a Pyrex (Corning #7740) glass wafer and anodically bonded to an oxidized silicon wafer into which fluidic channels of varying width and depth have been manufactured.
Micromechanical Devices With Embedded Electro-Thermal-Compliant Actuation
Authors: Moulton Timothy , Ananthasuresh G. K. 
Published: December 2021

Abstract
At micro scale, thermal actuation provides larger forces and is easier to control compared to the widely used electrostatic actuation. In this paper, we highlight a third advantage of thermal actuation viz. the ease with which it can be utilized to achieve a novel embedded electro-thermal-compliant (ETC) actuation for MEMS. A number of novel ETC building blocks and devices are described and their analysis and design issues are discussed. The devices were microfabricated using MCNC’s MUMPs foundry process as well as a bulk-micromachining process called PennSOIL (Penn Silicon-On-Insulator Layer). Experimental measurements are presented and reasons for discrepancies with the theoretical predictions are discussed.
Interactions of Nonlinear Permeability and Load Partitioning on Cartilage Mechanical Behavior
Authors: Araj M. J. , Wayne J. S. 
Published: December 2021

Abstract
Partitioning of an applied stress and material properties are two characteristics that can contribute to the longevity of articular cartilage in the demanding environment of diarthrodial joints. A biphasic finite element method (Wayne et al., 1991) predicted the behavior of a simulated joint surface while the load partitioning at the surface to solid and fluids phases (fluid support) and characteristics of the permeability of the tissue were varied. Increasing amounts of fluid support dramatically decreased cartilage deformation and solid stresses. Nonlinear permeability had a similar effect but a large gradient existed at the surface for low fluid support and increasing nonlinear permeability. Nonlinear permeability with high levels of fluid support had a minimal effect.
Dynamic Optimization to Characterize the Energy Efficiency of Kangaroo Locomotion
Authors: Rabinowicz Anna C. , Rodriguez-Monteverde David , Kaplan Matthew L. , Heegaard Jean H. 
Published: December 2021

Abstract
In this study we investigated the energy efficiency of kangaroo locomotion as a function of hopping speed. We tracked the motion of the joints and body segments of the Tammar wallaby (Macropus eugenii) using high-speed digital capture. Kinematic observations revealed that the height of the wallaby’s jump is uncoupled from its velocity for the speed ranges measured. Computing internal torques at the joints during the stance phase revealed a back and forth pattern of torque flow between the lower and upper links.
The Biomechanical Analysis of a Double Bundle Posterior Cruciate Ligament Reconstruction Using Robotic Technology
Authors: Janaushek Marsie A. , Woo Savio L.-Y. , Kanamori Akihiro , Vogrin Tracy M. , Yagi Masayoshi , Harner Christopher 
Published: December 2021

Abstract
The PCL consists of two primary bundles, the anterolateral (AL) and posteromedial (PM). The AL bundle is larger, stiffer, and has a higher ultimate load (Harner, 1995), and has been the focus of PCL replacement surgery (Clancy, 1983). However, clinical outcomes of PCL reconstruction have been unsatisfactory (Lipscomb, 1993); which has led to the question of the advancement of a double bundle procedure in hopes to more accurately reproduce the PCL (Clancy, 1998). It was therefore the objective of this study to evaluate the biomechanics of a double bundle PCL reconstruction (PCL-2), and compare these results with those obtained for the intact knee as well as a single bundle PCL reconstruction (PCL-1). To study this, a robotic/universal force-moment sensor (UFS) testing system which measures the multiple degree of freedom (DOF) knee kinematics determines the in situ force in the ligaments (or replacement grafts) in response to external loading conditions was utilized. The hypothesis was that PCL-2 would improve knee kinematics and in situ forces to those of the intact knee throughout the range of knee flexion as compared to PCL-1.
A Reliable and Accurate Method of Measuring Orthosis-Wearing Time
Authors: Havey Robert , Gavin Thomas , Patwardhan Avinash , Pawelczak Steven , Ibrahim Kamal 
Published: December 2021

Abstract
Orthosis-wearing compliance is considered to be an important factor in the outcome of orthotic treatment for idiopathic scoliosis (Rowe, et al. 1997; Katz, et al. 1997). However, at the present time a reliable and objective method of measuring orthosis-wearing time is lacking. Current estimates are based on self-reported compliance and estimated wear and tear of the orthosis itself. Availability of an accurate and reliable technique to measure how long a patient wears a prescribed spinal orthosis will allow clinicians to objectively study the relationship between patient compliance and outcome of orthotic treatment, and arrive at rational guidelines for prescribing orthosis wearing hours. The purpose of this study was to develop an accurate and reliable method to objectively measure spinal orthosis-wearing time.
Physiological Levels of Substrate Deformation Are Less Stimulatory to Bone Cells Compared to Fluid Flow
Authors: You Jun , Yellowley Clare E. , Donahue Henry J. , Jacobs Christopher R. 
Published: December 2021

Abstract
It is believed that bone cells can sense mechanical loading and alter bone external shape and internal structure to efficiently support the load bearing demands placed upon it. However, the mechanism by which bone cells sense and respond to their mechanical environment is still poorly understood. In particular, the load-induced signals to which bone cells respond, e.g. fluid flow, substrate deformation, electrokinetic effects etc., are unclear. Furthermore, there are few studies focused on the effects of physiological strain (strain &lt; 0.5%, Burr, 1996; Owan, 1997) on bone cells. The goal of this study was to investigate cytosolic Ca2+ mobilization (a very early signaling event) in response to different substrate strains (physiological or supra-physiological strains), and to distinguish the effects of substrate strain from those of fluid flow by applying precisely controlled strain without induced fluid flow. In addition, we quantified the effect of physiologically relevant fluid flow (Cowin, 1995) and substrate stretch on the expression of mRNA for the bone matrix protein osteopontin (OPN). A computer controlled stretch device was employed to apply different substrate strains, 0.1%, 1%, 5% and 10%. A parallel plate flow chamber was used to test cell responses to steady and oscillating flows (20dyn/cm2, 1Hz). Our data demonstrate that physiological strain (&lt; 0.5%) does not induce [Ca2+]i responses in primary rat osteoblastic cells (ROB) in vitro. However, there was a significant (p &lt; 0.05) increase in the number of responding cells at supra-physiological strains of 1, 5, and 10% suggesting that the cells were capable of a biological response. Similar results for human fetal osteoblastic cells (hFOB 1.19) and osteocyte-like cells (ML0-Y4) were obtained. Furthermore, compared to physiological substrate deformation, physiological fluid flow induced greater [Ca2+]i responses for hFOB cells, and these [Ca2+]i responses were quantitatively similar to those obtained for 10% substrate strain. Moreover we found no change in osteopontin mRNA expression after 0.5% strain stretch. Conversely, physiological oscillating flow (20dyn/cm2, 1Hz) caused a significant increase in osteopontin mRNA. These data suggest that, relative to fluid flow, substrate deformation may play less of a role in bone cell mechanotransduction.
Axial-Shear Failure Behavior of Human Femoral Trabecular Bone
Authors: Arramon Yves P. , Yeh Oscar C. , Morgan Elise F. , Keaveny Tony M. 
Published: December 2021

Abstract
An understanding of the failure of trabecular bone subjected to multiaxial loading has relevance in the mechanics of trauma and bone implant interfaces. The development of computer aided tomography-based computer models allow predictions of the mechanical behavior of whole bones when subjected to stress states too complex to be described analytically (Ford et al., 1996; Keyak et al., 1998; Oden et al., 1998). However, these models cannot confidently predict the failure of the trabecular bone without an experimentally validated multiaxial failure criterion.