Engineering Commons^™

Solubility Of Oxides From Zro2-Y2o3 And Zro2-Nd2o3 Systems In A Molten Cas. Selection Of A Thermal Barrier Composition Resistant To Cas Infiltration, Marie-Helene Vidal-Setif, Catherine Rio, Odile Lavigne, Nezha Chellah, Michel Vilasi, Cristophe Rapin, Carine Petitjean, Pierre Jean Panteix

Thermal Barrier Coatings IV

No abstract provided.

Should Expectations About The Rate Of New Antiretroviral Drug Development Impact The Timing Of Hiv Treatment Initiation And Expectations About Treatment Benefits?, Amin Khademi, R. Scott Braithwaite, Denis Saure, Andrew J. Schaefer, Kimberly Nucifora, Mark S. Roberts

Publications

Background: Many analyses of HIV treatment decisions assume a fixed formulary of HIV drugs. However, new drugs are approved nearly twice a year, and the rate of availability of new drugs may affect treatment decisions, particularly when to initiate antiretroviral therapy (ART).

Objectives: To determine the impact of considering the availability of new drugs on the optimal initiation criteria for ART and outcomes in patients with HIV/AIDS.

Methods: We enhanced a previously described simulation model of the optimal time to initiate ART to incorporate the rate of availability of new antiviral drugs. We assumed that the future rate of availability …

Novel Pattern Reconfigurable Antenna Arrays Using Engineered Metamaterials And Microfluidic Principles, Ahmad Gheethan

USF Tampa Graduate Theses and Dissertations

This dissertation proposes novel solutions for important drawbacks of antenna arrays. One of the main contributions of the presented work is size reduction and nulling performance improvement of traditionally large anti-jam global positioning system (GPS) arrays using miniature antennas and electrically small resonators emulating an engineered metamaterial. Specifically, a miniaturized coupled double loop (CDL) dual band antenna is first introduced as a small antenna element of the compact GPS array. The loops that are capacitively coupled using lumped element capacitor, and employ metallic pins around their perimeter to improve the radiation efficiency by achieving a volumetric current distribution. This design …

Initial Testing Of A Unitary Hvac System Advanced Control Module, Florida Solar Energy Center, Richard Raustad

FSEC Energy Research Center®

Testing of a unitary HVAC system advanced control module and the results.

Effect Of Temperature Dependent Viscosity On Natural Convective Boundary Layer Flow Over A Horizontal Plate Embedded In A Nanofluid Saturated Porous Medium, Shoba Bagai, Chandrashekhar Nishad

5th International Conference on Porous Media and Their Applications in Science, Engineering and Industry

The effect of temperature dependent viscosity on natural convective boundary-layer flow of a nano-fluid over an isothermal horizontal plate is investigated numerically. The viscosity of the fluid is assumed to have an exponentially decaying dependence on temperature ν=ν0e−b(T−T∞). A similarity analysis is presented for field equations embodying conservation of total mass, momentum, thermal energy and nano-particles. The analysis shows that velocity, temperature and nano-particle volume fraction profiles in the respective boundary layers depend on the viscosity parameter γ besides the pertinent parameters such as buoyancy ratio Nr, Brownian motion Nb, thermophoresis Nt and Lewis number Le. From physical considerations one …

Miscible Density Driven Convective Mass Transfer Process Analysis Based On Entransy Dissipation Theory, Rong Li, Ruina Xu, Peixue Jiang, Huihai Liu, Jiannan Chen

5th International Conference on Porous Media and Their Applications in Science, Engineering and Industry

Density driven convective mass transfer process in porous media is one of the most universal phenomena in underground aquifer. In this study, an original model defining Nu (or Sh) number for miscible mass transfer system was derived, based on basic concept of integrated entransy dissipation rate. Numerical simulation results of density driven convective mass transfer process in a closed Hele-Shaw cell and porous media are analyzed. In the process of dilute brine-water mass transfer system in Hele-Shaw cell, three different stages were observed. Meanwhile, time dependent entransy variation and Nu number using our definition also show three different steps in …

Experimental Analysis Of Air Vortex Impingement Through Porous Screens, Xudong An, Howard Fultz, Fatemeh Hassanipour

5th International Conference on Porous Media and Their Applications in Science, Engineering and Industry

This paper presents the experimental analysis of air flow vortex propagation through porous screens. This study is conducted by a new and unique experimental setup for ve- locity measurements and visualization of air vortex interac- tion with porous screen. A custom-made, high-precision vortex generator provides a variety of velocity profiles for vortex generation with an unprecedented level of precision. The flow fields are captured with the use of a fog gener- ator and a high-speed CCD camera. The porous screens are constructed out of acrylic rods with various orientations, thickness, and porosities from rod separation. The results presented in this …

Thermohydraulics Of Porous Heat Exchangers: Full Or Partial Blockage?, Kamel Hooman

5th International Conference on Porous Media and Their Applications in Science, Engineering and Industry

No abstract provided.

Concentration Of Bioethanol And Dehydration Of Organic Solvents By Porous Membranes, Tadashi Uragami

5th International Conference on Porous Media and Their Applications in Science, Engineering and Industry

In order to obtain higher membrane performance in the concentration of bioethanol and dehydration of organic solvents, porous poly[1-(trimethylsilyl)-1-propyne] (PTMSP) and porous chitosan membranes, respectively are applied to a temperature-difference controlled evapomeation (TDEV) method in which a temperature difference between the feed solution and the membrane surroundings is established. Pressure treated porous PTMS membranes showed a high ethanol concentration performance with a high permeation rate and porous chitosan membranes also showed a high dehydration performance in TDEV. Membrane performances through these porous membranes in TDEV are discussed from the viewpoints of physical structure of membranes and permeants.

Experimental Evaluation Of Wellbore Cement- Formation Shear Bond Strength In Presence Of Drilling Fluid Contamination, Mileva Radonjic, Arome Oyibo

5th International Conference on Porous Media and Their Applications in Science, Engineering and Industry

The objective of this experimental study is to investigate the impact of physical and chemical mud contaminations on cement-formation shear bond strength for sandstone and shale formations. Physical contamination occurs when drilling fluids (mud) dehydrates on the surface of the formation, while chemical contamination on the other hand occurs when the drilling fluid (still in the liquid state) is mixed with cement slurry and reacts chemically with the cement during a cementing job. We investigated the impact of the contamination on the shear bond strength and the changes in the mineralogy of the cement at the cement-formation interface to quantify …

Quantification Of Effect Of Convergence In Porous Media Flow, Srinivas Pasupuleti, Pradeep Kumar, K. Jayachandra

5th International Conference on Porous Media and Their Applications in Science, Engineering and Industry

An attempt is made in this study to quantify the effect of convergence on macroscopic scale in the case of flow through porous media. Experiments are conducted separately on specially conceived parallel flow permeameter and converging flow permeameter keeping identical inlet and outlet conditions, using eight sizes of coarse granular media and water as the fluid medium. The media is sieved through sieves of different sizes to separate the crushed rock into sizes of 3.25 mm, 4.73 mm, 10.00 mm, 11.64 mm, 13.10 mm, 20.10 mm, 28.90 mm and 39.50 mm and glass spheres of 15.41 mm, 18.03 mm and …

A Model For Magnetic Drug Targeting In A Permeable Microvessel With Spherical Porous Carrier Particles, Precious Sibanda, Sachin Shaw

5th International Conference on Porous Media and Their Applications in Science, Engineering and Industry

We present a mathematical model for targeting a drug at malignant tissue cells in a permeable microvessel. The drug molecules are transported in carrier particles which are assumed to be porous spheres. This mode of drug delivery is non-invasive and has less toxic effects on healthy cells and tissues. The microvessel tube (see Figure 1) is subdivided into three regions, the outer endothelial glycocalyx layer where the blood has a Newtonian character, and a core and plug regions where the blood flow is described using a non-Newtonian Casson fluid model which is suitable for microvessels of radius 5mμ. Targeting is …

Multilayer Minichannel Heat Sinks: The Effect Of Porosity Scaling On Pressure Drop, Arun K. Karunanithi,, Fatemeh Hassanipour

5th International Conference on Porous Media and Their Applications in Science, Engineering and Industry

Previous studies have shown that stacked multi-layer mini-channels heat sinks with square or circular channels have advantages over traditional single layered channels in terms of both pressure drop and thermal resistance. In this work, porous media is used in the multi-layered stacked mini-channels instead of square or rectangular channels and the effect of the same on pressure drop and thermal perfor- mance is studied. Porosity scaling is done between the lay- ers of porous media and is compared with unscaled stacked multilayer channel. Porosity scaling allows the porosity to vary from one layer to the next layer and could result …

Numerical Simulation Of Pressure Pulse Decay Experiment On Crushed Low Permeability Rocks Considering Klinkenberg Effect And Gas Absorption/Desorption, Bo Zhou, Rui-Na Xu, Pei-Xue Jiang

5th International Conference on Porous Media and Their Applications in Science, Engineering and Industry

Pressure pulse decay method is widely used for permeability tests for low permeability rock plug samples. This method can be used for crushed grain samples by removing the downstream chamber in standard pulse decay tests. Processes in pulse decay tests for low permeability crushed shale are investigated using numerical simulation. Both the Klinkenberg slip effect for gas flows in low permeability rock and the gas absorption/desorption in the porous matrix are considered. The complete mathematical model is set up to include the two effects. Deviation of the numerical pulse decay curve from the analytical one with an assumption that the …

Fluid Flows Through Unsaturated Porous Media: An Alternative Simulation Procedure, Maria Laura Martins-Costa, Joao Carlos Castro Dias, Rogerio M. Saldanha Da Gama

5th International Conference on Porous Media and Their Applications in Science, Engineering and Industry

This article studies fluid flows through an unsaturated porous matrix, modeled under a mixture theory viewpoint, which give rise to nonlinear hyperbolic systems. An alternative procedure is employed to simulate these nonlinear nonhomogeneous hyperbolic systems of two partial differential equations representing mass and momentum conservation for the fluid (liquid) constituent of mixture. An operator splitting technique is employed so that the nonhomogeneous system is split into a time-dependent ordinary portion and a homogeneous one. This latter is simulated by employing Glimm’s scheme and an approximate Riemann solver is used for marching between two consecutive time steps. This Riemann solver conveniently …

Numerical Study Of Forced Air Cooling Of A Heated Porous Foam Pyramid Array, Kevin Anderson, Maryann Shafahi, Alfredo Gutierrez, Watit Pakdee

5th International Conference on Porous Media and Their Applications in Science, Engineering and Industry

The current study employs CFD to study the forced air cooling of a pyramid shaped porous foam absorber. Herein, a three by three (3×3) array of porous foam absorbers heated with an external heat flux is modeled using the differential equations governing heat and fluid flow through porous media based on the Brinkman-Darcy flow equations and an effective thermal conductivity to account for the porous medium. The numerical simulations are carried out using the COMSOL commercial Computational Fluid Dynamics (CFD) Finite Element based software package. The primary finding of our study is that the more porous the foam absorber media …

Numerical Simulation Of 3-D Free Convection In Porous Media Due To Combined Surface Forced Convection And Internal Heat Generation, Kevin Anderson, Maryann Shafahi, Shawn Mcgann, Watit Pakdee

5th International Conference on Porous Media and Their Applications in Science, Engineering and Industry

A three-dimensional fluid-saturated porous medium model for natural convective flow has been developed, taking into account inertial and viscous forces within the fluid. The model consists of a cube with a top surface partially exposed to a steady, uniform convective heat flux and the entire domain to uniform internal heat generation. The differential equations for the Brinkman-extended Darcy model were formulated and non-dimensionalized, with numerical solutions obtained using the Galerkin finite element method. The results have been validated by comparison with previously published reports. It has been observed that the applied boundary conditions result in a central toroidal vortex driven …

Application Of Nanoparticles-Assembled Bi-Porous Structures To Power Electronics Cooling, Kazuhisa Yuki, Tessai Sugiura, Koichi Suzuki

5th International Conference on Porous Media and Their Applications in Science, Engineering and Industry

Nanoparticles-assembled bi-porous structure is newly proposed and its potential to enhance the boiling heat transfer is evaluated in order to develop a new cooling device toward 300W/cm2 of on-vehicle inverter cooling. In order to assemble nanoparticles on to a heat transfer surface as a thin layer, a boiling adhesion method (BAM) is originally introduced in which, water or water/ethanol solution with mono-dispersed nanoparticles is dropped or sprayed onto a high temperature surface, and then the nanoparticles deposit onto the heat transfer surface during the boiling. In addition to that, it is expected that boiling bubbles can produce micro or milli …

Three Dimensional Flow In A Sphere-Packed Pipe By Digital Holographic Ptv And Numerical Simultation, Shin-Ichi Satake, Yusuke Aoyagi, Takuma Tsuda, Noriyuki Unno, Kazuhisa Yuki

5th International Conference on Porous Media and Their Applications in Science, Engineering and Industry

In present study, high time-resolution flow field measurement in a sphere-packed pipe (SPP) is performed by the digital-holographic particle-tracking velocimetry. The visualization technique is carried out by a refractive index-matching method using a sodium iodide (NaI) solution employed as a working fluid. Hologram fringe images of particles behind the spheres can be observed, and the particles’ positions can be reconstructed by a digital hologram. Consequently, 3-D velocity-fields around the spheres are obtained by the reconstructed particles’ positions. In addition, numerical simulation of a sphere-packed pipe flow with Immersed Boundary technique is carried out to compare with the experimental value. In …

An Approximate Solution Of Fokker-Planck Equation For One Dimensional Groundwater Recharge Through Porous Media, Kajal Patel, Manoj Mehta, Twinkle Singh

5th International Conference on Porous Media and Their Applications in Science, Engineering and Industry

The nonlinear Fokker-Planck equation arising for one-dimensional groundwater recharge through porous media, is in the form of partial differential equation which has been solved by using Homotopy Analysis method with the help of first approximate solution ()0,ZTθfor given auxiliary parameter 0q=. The solution is physically interpreted and concluded that during one-dimensional recharge through unsaturated porous media, the moisture content of the soil is parabolically increasing as depth Z increases for given0T>. The graph of the solution is given by using Maple coding.

The Velocity Distribution In A Random Porous Medium, Maciej Matyka, Zbigniew Koza, Jaroslaw Golembiewski

5th International Conference on Porous Media and Their Applications in Science, Engineering and Industry

We investigate the velocity distribution function of the fluid flow through a model of random porous media. We examine how the form of the distribution changes with porosity. We find a crossover porosity at which the scaling character of the distribution changes and discuss our findings in the context of a nearly exponential velocity distribution function measured recently experimentally [Datta, S.S. et al. (2013) Phys. Rev. Lett. 111: 064501].

Experimental Study Of Water Retention Properties Of A High Performance Concrete With Small Sliced Samples, Qier Wu, Thomas Rougelot, Nicolas Burlion, Xavier Bourbon

5th International Conference on Porous Media and Their Applications in Science, Engineering and Industry

No abstract provided.

Experimental Study Of Water Retention Properties Of A High Performance Concrete With Small Sliced Samples, Qier Wu, Thomas Rougelot, Nicolas Burlion, Xavier Bourbon

5th International Conference on Porous Media and Their Applications in Science, Engineering and Industry

The aim of present study is to develop a practicable accelerated experimental method to obtain desorption isotherm of concrete more quickly and more reliably. A large number of sliced samples with thickness of 1, 2 and 3 mm have been de-saturated from fully water-saturated state to dry state. Time needed to obtain a mass stabilization varies from 14 to 30 days for concrete CEM I at a given relative humidity. Time saving is remarkable especially at lower relative humidity. Thinner samples lose their masses more quickly in the first week, but the thickness has hardly any influence on the total …

Hydra: Macroscopic Modeling Of Hybrid Ablative Thermal Protection System, G. Pinaud, J.M. Bouilly, J. Barcena, S. Florez, B. Perez, W. Fisher, V. Leroy, D. Bernard, T. Massuti, G. Herdrich, C. Zuber, W. Rotaermel

5th International Conference on Porous Media and Their Applications in Science, Engineering and Industry

In the framework of HYDRA, an European funded program, technological solutions of hybrid Thermal Protection System (TPS) are developed. This advanced shielding relies on the hybridization of upper lightweight porous ablative material and inner Ceramic Matrix Composite (CMC) bonded together with a novel high temperature adhesive. The aerial mass optimization of the full TPS requires a controlled reduction in the ablative material thickness to reach high operating temperature configuration of the CMC. Therefore, radiative heat transfer takes place in a thin layer of ablator and becomes a major contributor to the elevation of the interface temperature. In this paper we …

Engineered Multi-Layered Thermal Barrier Coatings For Enhanced Durability, Sanjay Sampath, Vaishak Viswanathan, Gopal Dwivedi

Thermal Barrier Coatings IV

No abstract provided.

High Temperature Oxidation And Burner Rig Testing Of Different Tbcs In The Frame Of The European Project Toppcoat: A Summary Of Results, Federico Cernuschi, Robert Vassen

Thermal Barrier Coatings IV

The major S&T objective of the project is the development of improved TBC systems using advanced bonding concepts in combination with additional protective functional coatings. The first specific objective will be to use these developments to provide a significant improvement to state-of-the-art APS coatings and hence provide a cost-effective alternative to EB-PVD. The second objective will be to combine these new concepts with new coating technologies to provide new, advance materials for thermal barrier systems with a capability exceeding the performance of EB-PVD coatings.

Zirconia-Doped Yttrium Tantalates As A Potential Next Generation Thermal Barrier Coating Material, David R. Clarke

Thermal Barrier Coatings IV

No abstract provided.

Stress And Crack Monitoring During Plasma Spraying Of Tbc, Seiji Kuroda, Xiancheng Zhang, Makoto Watanabe, Kaita Ito, Manabu Enoki

Thermal Barrier Coatings IV

Two types of process monitoring techniques are compared and discussed in this presentation. The first one is in-situ curvature monitoring, by which it was possible to evaluate the stress evolution during plasma spraying and separately identify the sources of stresses, i.e., the quenching stress and thermal stress as shown in Fig.1 (a). By changing the spraying parameters, it was possible to prepare specimens at largely different deposition temperatures, which resulted in significantly different levels of residual stresses. Also, it was found that the mechanical properties of the obtained YSZ coatings such as the elastic modulus are strongly dependent on the …

Suspension Plasma Sprayed Thermal Barrier Coatings, Per Nylen, Nicholas Curry, Ashish Ganvir, Nicolaie Markocsan

Thermal Barrier Coatings IV

No abstract provided.

New Class Of Refractory Ceramics For Thermal Barrier Coatings, Wei Pan

Thermal Barrier Coatings IV

No abstract provided.