bluuebunny/crossref_metadata_2025_split huggingface dataset:
An Investigation of the Hydrodynamics of a Rectangular Slot, Spouted Bed
Authors: Shirvanian P. A. , Calo J. M. , Hradil G. 
Published: November 2021

Abstract
An Eulerian model is presented that has been developed to describe the hydrodynamics of a rectangular slot, spouted bed experimental apparatus. This study was undertaken as a part of a project focused on the development of a Spouted Bed Electrolytic Reactor (SBER) for metals recovery. The results presented here include the effects of particle loading, inlet jet velocity, and bed geometry on void fraction distributions, pressure drop, and particle recirculation rate. The simulations show that pressure drop and particle recirculation rate both increase with inlet jet velocity and particle loading. However, at some point “choking” is predicted such that the particle recirculation rate will then remain constant with increasing particle loading and inlet jet velocity.
Viscous Flows Involving a Liquid-Vapor Compound Droplet
Authors: Palaniappan D. 
Published: November 2021

Abstract
Exact analytical solutions for steady-state axisymmetric creeping flows in and around a compound multiphase droplet are presented. The solutions given here explain the droplet fluid interactions in uniform and nonuniform flow fields. The compound droplet has a two-sphere geometry with the two spherical surfaces (of unequal radii) intersecting orthogonally. The surface tension forces are assumed to be sufficiently large so that the interfaces have uniform curvature. The singularity solutions for the uniform and paraboloidal flows in the presence of a compound droplet are derived using the method of reflections. The exact solutions for the velocity and pressure fields in the continuous and dispersed phases are given in terms of the fundamental singularities (Green’s functions) and their derivatives. It is found that flow fields and the drag forces depend on two parameters namely, the viscosity ratio and the radii ratio. In the case of paraboloidal flows, a single or a pair of eddies is noticed in the continuous phase for various values of these parameters. The eddies changes their size and shape if the size of the droplet is altered. These observations may be useful in the study of hydrodynamic interactions of compound droplets in complex situations. It is found that the Stokes resistance is greater when the liquid volume is large compared to the vapor volume in uniform flow. It is also noticed that the maximum value of the drag in paraboloidal flow depends on the viscosity ratio and significantly on the liquid volume in the dispersed phase. The exact solutions presented here may be useful for boundary integral formulations that are based on special kernels and also in validating numerical algorithms and codes on multiphase flow and droplet-fluid interactions.
Unsteady Pressure Measurement of an Axial Fan
Authors: Xu C. , Amano R. S. 
Published: November 2021

Abstract
An unsteady pressure measurement system was developed to measure the unsteady pressure field of an axial fan. The fan unsteady pressure fields of an inlet and outlet were obtained at three axial positions for seven-radial directions. The results showed that there is a relatively long response time for pressure drop both in inlet and outlet sections during the fan start-up. The measurements also showed that, due to the vortex shedding from the trailing edge of each fan blade, the fan outlet unsteady pressure distributions have a primary frequency related to the fan operating frequency. The time-dependent pressure measurements showed that pressure distributions of inlet and outlet during the fan start-up were severely unsteady and the main variation frequency of the pressure is much smaller than the fan rotational frequency. The pressure measurement on the fan blades showed that the pressure oscillations were mainly dominated by the vortex shedding from the fen blades. A flow visualization study was also performed to validate the flow characteristics near the blade surface. A complete set of time-dependent pressure measurements along the blade fan surfaces, fan inlet and outlet are suitable for an axial fan database for an industrial use as well as CFD code validation.
The Shutoff Head of a Centrifugal Impeller
Authors: Yedidiah S. 
Published: November 2021

Abstract
This paper discusses the effects of different design-parameters on the magnitude of the shutoff head of a centrifugal impeller. It shows, that the observed inconsistencies between existing theories and tests can be eliminated, by considering the angular speed of the liquid contained between the rotating shrouds and the stationary casing.
A Computational Optimization of a Laminar Flow in a Small Tube With Fenestrations
Authors: Sahin Iskender , Hovland Chris 
Published: November 2021

Abstract
An iterative approach by a CFD analysis was applied for optimizing the distribution of a laminar fluid flow through a small diameter tube with a closed end. The goal of the optimization was that flow rates through small discharge outlets (fenestrations) be close to uniform throughout the tube. Parameters used for the optimum design were: the pipe and fenestration hole diameters and the distribution of fenestration along the pipe, and the number of holes, among others. A numerical parameter describing the efficiency of each design was introduced and used for some comparisons.
Modelling of Hydraulic Forest Boom Tip Acceleration Control to Counterbalance the Gravitational Load Force in Horizontal Timber Cutting
Authors: Inberg Juha , Mattila Jouni , Virvalo Tapio 
Published: November 2021

Abstract
This paper concentrates on the forest machines, which are working in the cut-to-length method. The cutting function is an essential part of a harvester’s work in the cut-to-length method. The quality of cutting is the most significant feature of a cut. Trees should be cut without causing damage, especially end checks, to the cutting surface of wood. Nowadays end checks of logs are main problem of the cutting process. It has been observed that end checks are found in as many as 70% of the logs. The cutting damages reduce the amount of useful material and cause considerable economical loss to the sawmill and veneer industries.
The study deals with the boom lowering function, which is a potential solution to avoid cutting damages during the timber cutting process. The purpose is to momentarily counterbalance the gravitational force of a log during the cross-cut. This paper presents model derivation and analysis of the kinematics, dynamics and hydraulics of the studied forest boom. The paper also shows that the model can be used as a design tool to examine the influences of hydraulics and control system to the behaviour and performance of boom tip acceleration control in a horizontal timber cutting in future studies.
Predicting the Required Slipper Hold-Down Force Within an Axial-Piston Swash-Plate Type Hydrostatic Pump
Authors: Manring Noah D. 
Published: November 2021

Abstract
The objectives of this research are to determine the physical contributors that tend to separate the slippers from the swash plate within an axial-piston pump. Upon determining these contributors, the hold-down force that is required for maintaining contact between the slippers and the swash plate is determined. This force is then expressed in terms of pump design-parameters and operating conditions. Physically inspecting six industrial pumps and measuring the theoretical calculations against the a-posteriori results of successful pump designs validates the analytical results of this research. By confirming the analysis of this research, an a-priori approach is recommended for adequately specifying the required spring load for the slipper hold-down mechanism.
Effects of an Auxiliary Plate Position on Natural Convection in a Vertical Channel With Radiation
Authors: Andreozzi Assunta , Manca Oronzio , Morrone Biagio 
Published: November 2021

Abstract
This experimental paper analyzes the effects of auxiliary plate position along the centerline of a vertical channel on combined air natural convective and radiative heat transfer. These configurations can be found in the telecommunication systems and electronic cabinets with vertical cards.
The experiments are carried out by means of temperature measurements to obtain significant thermal parameters. A comparison between the different positions of the plate inside the channel is given in terms of channel wall temperatures. The results are given in terms of heated wall temperature profiles and radiative heat transfer for different thermal and geometrical parameters. Average Nusselt number as a function of the main thermal and geometrical parameters are presented and useful correlation equations are proposed. The comparison of the placement of the auxiliary plate, for high radiative heat transfer, shows that the auxiliary plate placed at the channel exit displays the lowest maximum channel wall temperatures when high Rayleigh numbers and heat flux values are considered. The configuration with this auxiliary plate placement is thoroughly examined for several h/L values and different emissivity coefficients. The channel aspect ratio, L/b, is equal to 10 and 20, the ratio of the auxiliary plate height to the channel one, h/L, 0, 0.25, 0.33 and 0.5, with emissivity coefficients of the walls equal to 0.1 and 0.9 and three different auxiliary plate positions inside the channel. The modified Rayleigh number values are in the 102–105 range.
A Neoclassical Growth Model for Population Dynamics in a Homogeneous Habitat
Authors: Vadasz Peter , Vadasz Alisa S. 
Published: November 2021

Abstract
A neoclassical model is proposed for the growth of cell and other populations in a homogeneous habitat. The model extends on the Logistic Growth Model (LGM) in a non-trivial way in order to address the cases where the Logistic Growth Model (LGM) fails short in recovering qualitative as well as quantitative features that appear in experimental data. These features include in some cases overshooting and oscillations, in others the existence of a “Lag Phase” at the initial growth stages, as well as an inflection point in the “In curve” of the population size. The proposed neoclassical model recovers also the Logistic Growth Curve as a special case. Comparisons of the solutions obtained from the proposed neoclassical model with experimental data confirm its quantitative validity, as well as its ability to recover a wide range of qualitative features captured in experiments.
Use of Saline Injection to Create Large Thermal Lesions During Radiofrequency Ablation Therapy: 1. Thermal Model
Authors: Curley Michael G. , Hamilton Patrick S. 
Published: November 2021

Abstract
Radiofrequency (RF) energy has been successfully used to treat tachycardia and liver cancer through hyperthermic ablation. However, this therapy is limited to treating small volumes because of the high current density near the RF electrode, which leads to excessive temperatures in this region.
We have developed an RF therapy that uses saline injection into the tissue surrounding the electrode to increase heat transfer in this tissue to heat significantly larger volumes. This paper shows the results of a finite difference thermal model of this therapy. Results indicate that saline-enhanced RF ablation can treat tissue volumes that are 33 times larger than those created by RF alone.
High-Speed Photographic Evaluation of Retropulsion Momentum Induced by a Laser Calculi Lithotriptor
Authors: Lee Ho , Kim Jeehyun , Choi Bernard , Teichman Joel M. H. , Welch A. J. 
Published: November 2021

Abstract
Since the mid-1980’s, many reports have demonstrated the clinical feasibility of fragmenting urinary and biliary calculi with high power lasers [1,2]. Several lasers such as pulsed dye, alexandrite and holmium:YAG have been successfully used as intracorporeal lithotriptors[3–5]. Calculus fragmentation is produced by the combination of direct thermal energy absorption and laser induced shock waves[5–7]. During this powerful laser-tissue interaction, the calculus is subject to a strong retropulsive momentum caused by particle ejection or laser induced shock waves[8]. If the stone cannot resist this kinetic momentum, it will recoil away from the laser delivery fiber. Then physicians must reorient the fiber to the stone for additional laser irradiation. This cumbersome process makes the procedure inconvenient and difficult and eventually prolongs the operation time. This study is designed to quantify the retropulsive momentum during pulsed laser lithotripsy.
Effect of Freezing on Cell Viability and Mechanical Strength of Bioartificial Tissues
Authors: Devireddy Ramachandra V. , Neidert Michael R. , Bischof John C. , Tranquillo Robert T. 
Published: November 2021

Abstract
The effect of freezing on the viability and mechanical strength of bioartificial tissues was determined under a variety of cooling conditions, with the ultimate aim of optimizing the cryopreservation process. Bioartificial tissues (i.e. tissue-equivalents or TEs) were prepared by incubating entrapped human foreskin fibroblasts in collagen gels for a period of 2 weeks. The bioartificial tissues were frozen using a controlled rate freezer at various cooling rates (0.5, 2, 5, 20, 40 and &gt; 1000°C/min or slam freezing). The viability (&lt; 60 min after thawing) of the fibroblasts in the bioartificial tissue was assessed using the Ethidium Homodimer (dead cells stain red) and Hoechst Give cells stain blue) assay. Uniaxial tension experiments were performed on an MTS Microbionix System (Eden Prairie, MN) to assess the post-thaw mechanical properties (Maximum Stiffness; Ultimate Tensile Stress; and Strain to Failure) of the frozen-thawed bioartificial tissue (≤ 3 hours after thawing). The results suggest that cooling rates of either 2 or 5°C/min are optimal for preserving both the cell viability and mechanical properties of the bioartificial tissues, post-freeze. Bioartificial tissues were also frozen using a directional solidification stage at 5°C/min. The post-thaw viability results are comparable in both the directionally cooled and the controlled rate freezer samples. However, the mechanical properties of the directionally cooled samples are significantly different (with a higher maximum stiffness and a lower strain to failure) than those obtained for samples frozen using a controlled rate freezer. This suggests that the directionality of ice propagation into the sample affects the measured mechanical properties.
Combustion Chemical Vapor Deposition of YSZ Thin Films for Fuel Cell Applications
Authors: Xu Zhigang , Sankar Jag , Wei Q. 
Published: November 2021

Abstract
Chemical vapor deposition (CVD) is well recognized as the most effective technique to prepare high-quality thin solid films. This technique can be classified into two categories according to the working pressure, i.e. low to very low pressure and high pressure CVD. In this paper, the high pressure CVD technique is interested to the authors. An atmospheric combustion chemical vapor deposition (ACCVD) system has been developed for yttria fully stabilized zirconia (YSZ) thin film processing. Various processing parameters, such as the ratio of oxygen to liquid fuel in flame, the concentration of metal reagents in the solution, the temperature of the substrate, and so on, have been investigated. The as-grown films are characterized with x-ray diffraction and scanning electron microscopy. Within the range of experimental parameters, the phase of the film is predominately cubic one. It was shown that the phase and crystallinity of the films are strongly dependent upon the experimental variable.
Diamond and Diamondlike Composites
Authors: Narayan R. J. , Wei Q. , Sankar J. , Narayan J. 
Published: November 2021

Abstract
Diamond, diamond-like, and their composites (with TiC, TiN, and AlN for diamond, and Cu, Ag, Ti, and Si for diamondlike carbon) have extremely desirable chemical, electrical, and mechanical properties. These corrosion- and erosion-resistant coatings have a wide variety of applications, ranging from biomedical device coatings to packaging of microelectronic devices. However, many of these applications are limited by the poor adhesion of these films to metals, ceramics, and polymers. The adhesion of a film is determined primarily by internal stresses in the film, thermal and lattice mismatch, and most importantly by interfacial bonding. We have developed methods based on mechanical interlocking, chemical bonding, grading of interatomic potentials, and the multilayer discontinuous thin films approach to control stresses and strains in thin films. A substantial improvement in adhesion and wear properties is obtained by using these methods selectively. We review issues related to the adhesion of diamond, diamond-like carbon, and composite films on metal, polymeric, and ceramic substrates.
Tunable Magnetic and Mechanical Properties in Metal Ceramic Composite Thin Films
Authors: Kumar D. , Sankar J. , Narayan J. , Kvit A. 
Published: November 2021

Abstract
Presently a wide spread of research activities is pursued in the area of theoretical, computational and experimental aspects of vibration studies in laminated composite structures with embedded or surface bonded smart layers in order to improve the performance of components in aerospace, mechanical, robotics, and electronic equipments. The key to the successful fabrication of these components with improved properties is the development of smart materials by materials engineering and understanding the fundamentals of materials science. It is in this context that we have developed a novel smart thin film processing method based upon pulsed laser deposition to process nanocrystalline materials with accurate size and interface control with improved mechanical and magnetic properties. Using this method, single domain nanocrystalline Fe and Ni particles in 5–10 nm size range embedded in amorphous as well as crystalline alumina have been produced. By controlling the size distribution in confined layers, it was possible to tune the magnetic properties from superparamagnetic to ferromagnetic in a controlled way. Magnetization measurements of these thin film composites as function of field and temperature were carried out using a superconducting quantum interference device (SQUID) magnetometer. Magnetic hysteresis characteristics below the blocking temperature are consistent with single-domain behavior. Mechanical properties were measured using nano-indentation measurements. The hardness of the Fe and Ni-Al2O3 nanocomposites was found to vary strongly with the size do Fe and Ni nanodots in the alumina matrix. For example, the hardness of Fe-Al2O3 system increased from 15 GPa to 28 GPa when the size of Fe dots in alumina was increased from 5 nm to 9 nm. It is envisioned that this types of smart films can be used in magnetic recording, ferrofluid technology, magnetocaloric refrigeration, biomedicine, biotechnology, aerospace applications where hard and wear-resistant coatings are also very important for its survival.
Nanofunctionalized Phosphor Particles for Advanced Display Applications
Authors: Ollinger Michael , Craciun Valentin , Singh Rajiv 
Published: November 2021

Abstract
Cathodoluminescence (CL) degradation measurements showed that by applying a nano meter scale indium tin oxide (ITO) coating on micron sized ZnS:Ag particulates the degradation lifetime was dramatically improved. X-ray photoelectron spectroscopy (XPS) analysis showed that the Zn 2p3/2 and S 2p3/2 peaks of the degraded ZnS:Ag were shifted to higher binding energies, which correspond to oxidized elements, with respect to those found for as-received ZnS:Ag. The XPS analysis for the ITO coated ZnS:Ag showed a broadening of the Zn 2p3/2 and S 2p3/2 peaks, which were a convolution of two peaks. In this case, the Zn 2p3/2 and S 2p3/2 peaks corresponding to ZnS were still present together with a small shoulder corresponding to the oxidized elements. This difference in the XPS shows that the ITO coating reduced the degradation rate by slowing the surface chemical changes on the ZnS:Ag.
Development of an Injection Valve for Liquid Molding Applications
Authors: Karas Christopher P. , Sheyman Vladimir , Rathod Mulchand S. 
Published: November 2021

Abstract
This paper is deals with the development of an innovative pneumatically operated injection valve for liquid molding applications. The work in this paper was carried out in a senior design project of one of the authors.
A specialized pneumatically operated valve to eliminate the manual step of tubing removal has been designed, fabricated and tested. To evaluate this valve, special test equipment was designed and fabricated, and a specific procedure for testing was developed. The results obtained from the testing indicated that the valve works properly according to the established specification and requirements, and passed air leak checks at different inlet and outlet configurations.
The proposed valve is very unique since it allows the catalyzed resin to flow into the mold cavity when it is opened. It allows cycle flushing of the solvent and air into a waste receptacle when it is closed. From the testing and understanding the functionality of the developed valve, it is determined that pneumatically operated injection valve is a viable component that could be used in a production environment to further enhance productivity.
Underwater Pipeline Inspection Using Guided Waves
Authors: Na Won-Bae , Kundu Tribikram 
Published: November 2021

Abstract
Underwater pipeline inspections are conducted using ultrasonic cylindrical guided waves in the laboratory environment. Three different types of mechanical defects - gouge, removed metal, and dent, are fabricated in small diameter, 22.22 mm, aluminum pipes and tested. To efficiently propagate the antisymmetric (flexural) cylindrical guided waves through the aluminum pipe in water, a new transducer holder device is designed. The device uses commercially available ultrasonic transducers that generate compressional ultrasonic waves in the water. The device can change the striking angle of the incident beam from 0° to 51°. With the help of this device the incident angle adjustment and frequency sweeping can be carried out. This is necessary for obtaining the time history of the received signals for various incident angles and signal frequencies; then these time histories are converted to V(f) curves, or received signal amplitude vs. frequency curves. From the amplitude of these V(f) curves the type and extent of the mechanical defects can be estimated. This investigation shows that the new coupler device can be effectively used for health monitoring of underwater pipelines using guided waves.
A Model for Fatigue Crack Initiation From Notches
Authors: Zaki A. S. , Ghonem H. 
Published: November 2021

Abstract
A model is developed to predict the number of cycles for fatigue crack initiation from a notch. It is based on the concept that the initiation of a fatigue crack occurs when the accumulated plastic shear deformation in the notch root reaches a critical limit which is defined in terms of the threshold stress intensity factor of the material under consideration. A viscoplastic analysis using unified constitutive equations is employed in order to describe the evolution of the notch plastic zone size as well as the stress and plastic strain distributions within this zone on cycle by cycle basis. This analysis takes into consideration the material s time- and cyclic-dependent characteristics. Experimental verification of the model was carried out using specimens made of AM350, an austenitic steel alloy: A series of crack growth measurements were performed in order to calculate the threshold stress intensity factor which is then used to determine the plastic deformation limit of this alloy. The model is used to calculate the number of cycles to crack initiation which is compared to that obtained experimentally under various loading parameters. The correlation between the model prediction and the experimental results are reported and discussed.