bluuebunny/crossref_metadata_2025_split huggingface dataset:
Arterial Wall Transport Simulation: Porohyperelastic/Transport Finite Element Models
Authors: Kaufmann M. V. , Simon B. R. , Baldwin A. L. 
Published: July 2023

Abstract
Porohyperelastic transport-swelling (PHETS) models (Kaufmann [1996], Simon et al [1995]) for soft tissues have been developed and applied to problems of transport within the walls of large arteries. The general theory developed in [Kaufmann, 1996] includes mass transport by diffusion and convection, the influence of electrical and chemical potentials, and osmotic swelling, as well as the characteristic nonlinear finite deformation of the tissue. The models couple the behavior of the porous solid skeleton, mobile tissue fluid and concentrations of charged species. This abstract presents a finite element model (FEM) of the convection-diffusion of an uncharged single species through a rabbit aorta under various intraluminal pressures. The results of these models show good qualitative agreement with experimental results. The general PHETS theory coupled with the FEM implementation of the theory could provide insight into the transport associated with causal factors of atherosclerosis. The models can be used to study the effectiveness of various drug delivery systems.
A Finite Element Investigation of Solid Phase Transverse Isotropy in Contacting Biphasic Cartilage Layers
Authors: Donzelli Peter S. , Spilker Robert L. 
Published: July 2023

Abstract
Most biological materials are anisotropic and inhomogeneous. Experimental studies of cartilage, meniscus, bone, ligament and tendon all point to orthotropic and nonlinear material response to applied load. In studying joint articulation these nonlinearities, along with complex, curved geometries and the nonlinearity implicit in contact, must be modeled, making analytic investigations of joint contact biomechanics intractable. Since articular contact plays the primary role in load transfer in joints, we will explore the effect of tissue anisotropy using a canonical joint contact problem. A biphasic contact finite element model (1, 2) will be employed for this investigation so the important fluid flow and stress-shielding effects (3, 4) can be understood.
Coupled Fluid-Structure Analysis of Bi-Leaflet Mitral Mechanical Heart Valve Dynamics
Authors: Makhijani Vinod B. , Siegel John M. , Singhal Ashok K. 
Published: July 2023

Abstract
Several important design problems with contemporary mechanical heart valve (MHV) prostheses such as thrombus formation and hemolytic trauma can be attributed to the valve fluid dynamics. Blood flow in the vicinity of the valve is influenced by valve motion which, in turn, is influenced by time-varying fluid-imposed lift and drag forces on the occluder. Thus, the valve fluid and structure dynamics are linked through complex fluid-structure interactions. In order to develop design criteria for MHVs with improved valve closure efficiency and minimized flow resistance and fluid shear stresses, both valve occluder and blood flow dynamics need to be simultaneously considered.
Virtual Reality Training Simulation With Force Feedback: Palpation of Lesions
Authors: Langrana Noshir , Burdea Grigore , Dinsmore Michael , Gomez Daniel , Harper Eric , Silver Deborah , Mezrich Reuben 
Published: July 2023

Abstract
Our current goal is to combine the advantages of medical imaging with force feedback technology to develop a virtual simulation where the user can touch soft tissue looking for a tumor beneath the surface. When it is touched, the tumor gives a different force profile, making it feel as though something is actually beneath the surface. If this capability was combined with medical imaging, the physician would be able to touch and examine organs that were not previously palpable without surgery.
Hybrid Approach to the Biomechanical Design of a Dummy Human Neck
Authors: Yoganandan Narayan , Cheng Joseph , Pintar Frank A. , Shams T. , Rangarajan Nagarajan 
Published: July 2023

Abstract
A hybrid approach combining the efforts of computer modeling and experimental testing was used to advance the design of a new dummy neck with improved biofidelity. A lumped spring-mass-dashpot model was exercised including the appropriate anthropomorphic, kinematic, and dynamic performance requirements. The prototype consisted of five layers of aluminum and butyl rubber discs. A pair of cables were inferiorly attached with springs connecting the head to the base of the neck in the anterior and posterior regions. Flexion, extension, and lateral bending tests were conducted at velocities ranging from five to ten mph. Dynamic biomechanical and high-speed photography data were analyzed. Increasing velocities produced increasing magnitudes of forces, moments, accelerations and angular velocities. The experimental response from the prototype dummy neck closely matched with computer simulations. The head-neck rotation angle, head-lag angle, and the head center of gravity displacement correlated with computer simulations. Principles of computer modeling combined with the dynamic experimental techniques are a valuable tool to advance the design of a new anthropomorphic neck.
Thermal Analysis of Two-Phase Microchannel Cooling
Authors: Chen N. C. J. , Felde D. K. , Yoder G. L. 
Published: July 2023

Abstract
A design calculation has been performed to determine thermal limits in support of an experiment in two-phase microchannel water cooling. Under the operating conditions (one atmosphere pressure and 23°C inlet temperature), the calculation predicts that the experimental channel can withstand a maximum surface temperature of 115°C and a heat flux up to 975 W/cm2 without exceeding the critical heat flux limit. The predicted results also indicate that a uniform heat flux along the channel in the two-phase domain can be achieved so that the heat losses from the experimental test section can be calculated in a straightforward manner.
Liquid Flow Characteristics in a Diamond-Pattern Micro-Heat-Exchanger
Authors: Ravigururajan T. S. , Drost M. K. 
Published: July 2023

Abstract
The paper outlines the single-phase flow characteristics of a diamond-pattern micro-heat-exchanger. An experimental setup was built to study the characteristics of micro-channel heat exchangers. The experimental study was conducted for the following parameters: working fluid - Refrigerant-124; mass flow rate - 35 ml/min to 260 ml/min; and heat flux - 10 W/cm2 to 100 W/cm2. The heat transfer enhancement is less than that obtained in a parallel-channel micro-heat-exchanger. The enhancement is also independent of the mass flow rate. The pressure drop increased at a rate faster than that experienced in a parallel-channel flow.
Development of a Micropump for Microelectronic Cooling
Authors: Wong C. Channy , Adkins Douglas R. , Chu Dahwey 
Published: July 2023

Abstract
To demonstrate a system integration process for Micro-Electro-Mechanical Systems (MEMS), we are building an active cooling MEMS unit for microelectronics applications. This integrated unit will incorporate a micropump, temperature sensors, microchannels, and heat exchange devices into a single unit. The first phase of this research project is to develop and test a micropump capable of moving the working fluid within the integrated device. This paper will discuss the design, development, testing, and evaluation of a micropump concept.
The micropump which was developed is an electrohydrodynamic (EHD) injection pump. Fabrication of the pump was accomplished using laser micromachining technology, and two initial designs were examined for full fabrication. The first design has two silicon parts stacked vertically on top of each other. Gold is deposited on one side of each stacked plate to serve as electrodes for the electrohydrodynamic pump. A Nd:YAG laser is used to drill an array of circular holes in the “well” region of both silicon parts, leaving an open pathway for fluid movement. Next the silicon parts are aligned and bonded together, thus becoming a EHD pump. Fluid flow has been observed when an electric voltage is applied across the electrodes. The second design has the silicon parts which contain the flow grid oriented “back-to-back” and bonded together. This “back-to-back” design has a shorter grid distance between the anode and cathode plates so that a smaller voltage is required for pumping. Preliminary results from laboratory experiments have demonstrated that this EHD micropump design can achieve a pressure head of about 287 Pa with an applied voltage of 120 V.
A Coupled Numerical Technique for Self-Consistent Analysis of Micro-Electro-Mechanical-Systems
Authors: Aluru N. R. , White J. 
Published: July 2023

Abstract
An efficient algorithm for self-consistent analysis of 3-D micro-electro-mechanical-systems (MEMS) is described. The algorithm employs a hybrid finite-element/boundary-element technique for coupled mechanical and electrical analysis. The coupled algorithm is shown to converge rapidly and is much faster than relaxation for tightly coupled problems.
Towards a Functional MEMS Neurowell by Physiological Experimentation
Authors: Wright John A. , Tatic-Lucic Svetlana , Tai Yu-Chong , Maher Michael P. , Dvorak Hannah , Pine Jerome 
Published: July 2023

Abstract
Specificity in neuron targeting during stimulation and recording is essential in executing complex neuronal network studies. Physiological experiments have shown that young (less than one week old) cultured neurons can escape through a 0.5 μm-square hole. Through iterative physiological experimentation, a functional MEMS structure we call a canopy neurowell has been developed. Essentially a micromechanical cage, the structure consists of a well, an electrode bottom, and a nitride canopy cover with integrated micro-tunnels. It is able to physically confine, and make electrical contact with, a neuron. Potentially, neurowells are capable of multi-site studying of long-term, in vitro and in vivo neural systems. Experiments show that the canopy neurowell is mechanically functional and biologically compatible.
Design Techniques for Minimizing Manufacturing Variations in Surface Micromachined Accelerometers
Authors: Bart Stephen F. , Samuels Howard R. 
Published: July 2023

Abstract
In an effort to improve performance and reduce die area and cost, we have developed an open-loop surface-micromachined accelerometer, the ADXL76. The deposition and etching processes which define the dimensions of the sensing structure can have a wide variation in their characteristics, which can lead to large variations in output sensitivity. This paper describes techniques which were used to design an accelerometer structure that is significantly less sensitive to these dimensional variations.
Symmetry was used throughout the structure. In addition to the global four-fold symmetry of the overall structure, local symmetry in the series capacitor unit cells and tether environments was used. This included adding extra etch uniformity structures which make the etch environment around the tethers equivalent to the etch environment around capacitor gaps. The use of these etch uniformity structures increased the correlation between the tether width and the capacitor gap by almost a factor of 4. In addition, the sensors nominal geometry was optimized to minimize the variation of the output sensitivity due to etch and warpage variations. Using these techniques, the ADXL76 accelerometer demonstrated a factor of 2 reduction in the standard deviation of pre-trim sensitivity as compared to an equivalent design that did not use these techniques. This improved sensitivity distribution allows for a smaller trim range, which results in the use of less die area and a faster trim. In addition, the improved correlation between the as-fabricated tether width and capacitor gap allows for more accurate trimming. Thus the overall post-trim sensitivity distribution is much improved as compared to previous closed-loop accelerometer designs.
Pressure-Shear Impact Investigation of the Dynamic Response of Ceramics
Authors: Sundaram Sairam , Clifton Rodney J. 
Published: July 2023

Abstract
Results of pressure-shear plate impact experiments on an alumina ceramic (AD85) containing a significant amount of glassy phase are presented. The ceramic shows a weak, strain softening behavior; this has been attributed to the intergranular glassy phase. The ceramic is modeled by using an atomistic constitutive model for the response of the glass. This model utilizes the concept of free volume. Computations performed using this constitutive model show that the increase in free volume that occurs during the deformation is responsible for the observed softening response.
Statistical Aspects of Toughness in Brittle Fracture
Authors: Chudnovsky Alexander I. , Gorelik Michael L. 
Published: July 2023

Abstract
Statistical features of brittle fracture such as tortuousity of crack path, scale effect and scatter of toughness parameters are well documented. The apparent randomness of the process is closely associated with the distribution of defects on various scales within a solid. The phenomenological description of microdefects is represented by a random field of specific fracture energy γ following the framework of Statistical Fracture Mechanics (SFM). A brief review of SFM is presented. SFM is a first theory that proposed a way to relate the fracture toughness and roughness of crack path using continuum mechanics formalism. At the same time, the engineering application of the model was limited due to its mathematical complexity. We employ the Monte Carlo method to overcome the analytical difficulties of SFM. Fracture toughness dependency on the tortuousity of crack trajectories, loading conditions and material microstructure are illustrated by computer simulation of tests for common specimen geometries. The ambiguity of the concept of conventional toughness is addressed.
Localization in Disordered Brittle Media: Lattice Models
Authors: Mastilovic Sreten , Vujosevic Milena , Krajcinovic Dusan 
Published: July 2023

Abstract
The transition from a statistically homogeneous to a heterogeneous strain field is one of the frequently considered and often poorly understood intrinsic failure modes in damage tolerant materials with a disordered microstructure and inferior cohesive (fracture) strength. This type of transition occurs in brittle materials, such as rocks and concrete, primarily but not exclusively in the absence of long range tensile principal stresses. Numerous analytical and experimental studies were focused on the purely phenomenological, deterministic and continuum aspects of the deformation of a laterally confined cylindrical specimen subjected to the axial compression. At the same time the stochastic aspects of the problem and the effect that the disordered micro-structure of the material has on the localization have been only occasionally subjected to scrutiny. Similar failure modes may also take place in brittle materials subjected to high velocity impacts or random fluctuations of temperature. The focus of this short study is to highlight the non-deterministic aspects of the localization phenomenon using the methods of the statistical physics. At the current stage of this research program only the two-dimensional models were considered. Hence, the derived conclusions are largely of a qualitative nature.
Damage Evolution of Particulate Reinforced Titanium Composites
Authors: Tong Wei , Huang Shan , Li Xianghong 
Published: July 2023

Abstract
Particulate reinforced titanium matrix composites are relatively a new class of metal matrix composites, which are superior to aluminum matrix composites in high temperature (up to 650°C) and corrosive conditions (Abkowitz et al. 1995, Tong et al. 1995, Tong, 1996). Particulate-reinforced titanium composites are shown to have increased stiffness and strength; but their tensile ductility is strongly affected by the degree of metal-ceramic interfacial reaction during the consolidation and post-consolidation annealing processes (Tong et al. 1994). Formability and related damage evolution of such materials under dynamic loading are regarded to be vital to their secondary rapid forming, machining, cutting, and to the understanding of their wear and erosion properties. Some reinforcement particle damages have been observed during the processing of titanium composites, which can be related to the rapid build-up of very large local high stresses (Tong and Ravichandran 1994, Benson et al. 1995). The initiation and growth of damages at macro to micro scales in titanium composites are the focus of this investigation. The outcome of the investigation provides valuable guidance for optimizing materials processing for improved performance of particulate reinforced titanium composites and for their potential engineering applications.
The Effect of Cell Size on the Tensile Behavior of Microcellular Polycarbonate
Authors: Kumar Vipin , Weller John E. 
Published: July 2023

Abstract
Previously, processing conditions were presented that produce polycarbonate (PC) foams with the same density and significantly different average cell size (Kumar and Weller, 1994a). It was shown that the average cell size could be varied by an order of magnitude in different foams while maintaining the same foam density. The ability to produce foams with controlled density and cell size opened the possibility for a systematic evaluation of the effect of cell size on the mechanical properties of cellular materials.
A set of experiments was performed to determine if cell size (or equivalently processing conditions) had an affects the tensile behavior of microcellular polycarbonate. A series of tensile tests was performed on polycarbonate foams where the cell size was varied from approximately 2 μm to 37 μm, while the relative density was held nearly constant at 0.56. It was determined that the tensile behavior of microcellular PC is not affected by the average cell size for the range of microstructures produced in this study. The stiffness, strength and toughness showed no definitive trends with cell size. Consequently, the only microstructural variable that determines the tensile properties is the bulk foam density.
Study of Foam Sheet Formation: Part III — Effects of Foam Thickness and Cell Density
Authors: Lee S. T. , Ramesh N. S. 
Published: July 2023

Abstract
The existing cell growth model in the literature has been modified to include the gas loss effects due to surface evaporation experienced in a high surface to volume ratio of this foam sheet formation. As it exits from the high pressure die, nucleation occurs due to sudden pressure drop and then the sheet experiences natural cooling, expansion due to gas diffusion and gas loss from its surface. Rheological experiments were performed to supply simulation parameters for the modeling using the Haake rheometer. Both HCFC-22 and -142b were studied with low density polyethylene (LDPE) in generating the rheological data. They were also used to make foams to generate experimental data discussed in this paper using a 70 mm counter-rotating twin screw extruder. The theoretical and experimental results are compared in terms of foam density and foaming efficiency. Foaming efficiency is defined as the actual expansion over maximum possible theoretical expansion dictated by the ideal gas law for a particular blowing agent. The agreement is good when the foam expansion is under ten times and the deviation increases when the foam expands further, in which bubble-bubble interaction effects become significant.
Early Triassic roll-back of subducted Paleo-Tethys oceanic lithosphere: Insights from A2-type silicic igneous rocks in the Pingxiang area, southwest China
Authors: Huang Wen-Min , Liu Xi-Jun , Liu Lei , Li Zheng-Lin , Liu Xiao , Wu Hao 
Published: July 2023

Abstract
A suite of subduction-related early Triassic igneous rocks crops out in the Pingxiang area of the Dian-Qiong suture (DQS) in southwest China; this suite represents an important geological record of subduction and closure of the Paleo-Tethys Ocean. In this study, we report geochronological, geochemical, and Nd-Hf isotope data for newly discovered rhyolites and biotite granites in the Pingxiang area. We use these data to constrain their emplacement ages, origins, and geodynamic implications. Zircon U-Pb dating indicates that the rhyolites and biotite granites were emplaced at 251–250 Ma and 249 Ma (early Triassic), respectively. The rhyolites and biotite granites have elevated FeOT/(FeOT + MgO) (0.78–0.89) and 10,000 × Ga/Al (2.83–4.11) ratios, with geochemical affinities to A2-type granites. These rocks are enriched in some large-ion lithophile elements (e.g., Rb, Th, and Ba) and depleted in high-field-strength elements (e.g., Nb, Ta, and Ti), indicating their formation in a subduction-related arc. The rhyolites and biotite granites have negative whole-rock εNd(t) (−11.5 to −9.7) and zircon εHf(t) (−14.5 to −6.2) values, suggesting that these magmas were derived from an ancient crust-dominated source. Geochemical and Nd isotope data reveal that the peraluminous A2-type rhyolites and biotite granites were derived by partial melting of felsic crustal rocks under low-pressure and high-temperature conditions. By integrating all the available data with the regional tectonic evolution of the southwestern Youjiang Basin and adjacent regions, we attribute the generation of the peraluminous A2-type rhyolites and biotite granites to the extensional setting that existed during oceanic subduction, which was induced by roll-back of thePaleo-Tethys oceanic lithosphere at 251–249 Ma. This study indicates that subduction-related magmatism related to Paleo-Tethys oceanic lithosphere was still active in the early Triassic.
Recurrent metastatic angiosarcoma presenting as Kasabach-Merritt syndrome
Authors: Dhabhar Jeyhan Boman , Mehta Varshil 
Published: July 2023

Angiosarcoma is an incredibly rare type of malignancy, accounting for only 1%–2% of all soft-tissue sarcomas globally. It is clinically, pathologically and radiologically difficult to diagnose angiosarcoma owing to its varied presentation with little or no well-defined imaging findings.Kasabach-Merritt syndrome is also a lesser-heard entity which carries extremely poor prognosis. It is primarily seen in infants with vascular malformations and in kaposiform haemangioendothelioma. It is a condition of consumptive coagulopathy and only few of the cases have been reported so far in the adults with a background of angiosarcoma.This report presents the case of a male in his 70s who was diagnosed with metastatic angiosarcoma and experienced a complicated disease course due to Kasabach-Merritt syndrome.
Placement of an intrasaccular flow diverter in an intracranial sidewall aneurysm using the Bendit articulating microcatheter
Authors: Devarajan Alex , Al-Kawaz Mais , Giovanni Brian , Tabani Halima , Shigematsu Tomoyoshi , Fifi Johanna T 
Published: July 2023

Intrasaccular flow diversion is a new endovascular option for managing unruptured intracranial aneurysms.1–6 However, catheter ejection can occur during placement of an intrasaccular flow diverter, especially in tortuous vasculature that creates unfavorable angles between the aneurysm neck and the parent vessel.5 The Bendit steerable microcatheter (Bendit Technologies, Petah Tikva, Israel) can dynamically change its tip angle and may mitigate these placement concerns.7–9 Here, we report the placement of an intrasaccular flow diverter for the treatment of an unruptured internal carotid artery sidewall aneurysm at an unfavorable neck angle using the Bendit microcatheter (video 1). The Bendit was navigated around the 180° turn of the carotid siphon and held a stable position during device delivery. The device was sequentially deployed as the Bendit was progressively straightened and was successfully placed within the aneurysm. No neurological complications were experienced and the patient was asymptomatic on follow-up 3 months later.Video 1Placement of an intrasaccular flow diverter in an intracranial sidewall aneurysm using the Bendit articulating microcatheter.