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Creep Of Nextel 720/A Ceramic Matrix Composite With Laser Drilled Effusion Holes At 1200°C In Air And In Steam, Savannah N. Minor 2018 Air Force Institute of Technology

Creep Of Nextel 720/A Ceramic Matrix Composite With Laser Drilled Effusion Holes At 1200°C In Air And In Steam, Savannah N. Minor

Theses and Dissertations

Creep behavior of an oxide-oxide ceramic matrix composite (CMC) containing an array of effusion holes was investigated at 1200⁰C in air and in steam. The composite (N720/A) consisted of a porous alumina matrix reinforced with alumina-mullite NextelTM 720 fibers. Test specimens had an array of 17 effusion holes with 0.5-mm diameter. The effusion holes were drilled through the specimen thickness normal to the specimen surface using a CO2 laser. Effect of the effusion holes on tensile properties was evaluated tension tests to failure at 1200°C in air. Creep of specimens with effusion holes at 1200°C was ...


Influence Of Coolant Flow Rate Parameters In Scaling Gas Turbine Cooling Effectiveness On A Flat Plate, Jacob P. Fischer 2018 Air Force Institute of Technology

Influence Of Coolant Flow Rate Parameters In Scaling Gas Turbine Cooling Effectiveness On A Flat Plate, Jacob P. Fischer

Theses and Dissertations

Effective film cooling relies on the performance of the selected cooling hole shape and placement of the holes on the surface of the blade. To test each holes effectiveness, large scale, low-temperature testing has been used to reduce cost and complexity. The resulting quantity from this testing is called the adiabatic effectiveness (n). The adiabatic effectiveness can then scaled up to engine operating conditions to predict how the selected film cooling hole will perform. This process is complicated by the nonlinear variation of gas properties between coolant and freestream conditions as well as between the experimental and engine conditions. In ...


The Effect Of Poly (Glycerol Sebacate) Incorporation Within Hybrid Chitin–Lignin Sol–Gel Nanofibrous Scaffolds, Tuerdimaimaiti Abudula, Lassaad Gzara, Giovanna Simonetti, Ahmed Alshahrie, Numan Salah, Pierfrancesco Morganti, Angelo Chianese, Afsoon Fallahi, Ali Tamayol, Sidi A. Bencherif, Adnan Memic 2018 King Abdul Aziz University

The Effect Of Poly (Glycerol Sebacate) Incorporation Within Hybrid Chitin–Lignin Sol–Gel Nanofibrous Scaffolds, Tuerdimaimaiti Abudula, Lassaad Gzara, Giovanna Simonetti, Ahmed Alshahrie, Numan Salah, Pierfrancesco Morganti, Angelo Chianese, Afsoon Fallahi, Ali Tamayol, Sidi A. Bencherif, Adnan Memic

Mechanical & Materials Engineering Faculty Publications

Chitin and lignin primarily accumulate as bio-waste resulting from byproducts of crustacean crusts and plant biomass. Recently, their use has been proposed for diverse and unique bioengineering applications, amongst others. However, their weak mechanical properties need to be improved in order to facilitate their industrial utilization. In this paper, we fabricated hybrid fibers composed of a chitin–lignin (CL)-based sol–gel mixture and elastomeric poly (glycerol sebacate) (PGS) using a standard electrospinning approach. Obtained results showed that PGS could be coherently blended with the sol–gel mixture to form a nanofibrous scaffold exhibiting remarkable mechanical performance and improved antibacterial ...


Nanoscale Mechanisms For High-Pressure Mechanochemistry: A Phase Field Study, Mahdi Javanbakht, Valery I. Levitas 2018 Isfahan University of Technology

Nanoscale Mechanisms For High-Pressure Mechanochemistry: A Phase Field Study, Mahdi Javanbakht, Valery I. Levitas

Aerospace Engineering Publications

Coupled evolution of a high-pressure phase (HPP) and dislocations, including dislocation pileups and dislocations generated due to phase transformation (PT), under compression and shear of a nanograined bicrystal, is considered as a model for high-pressure mechanochemistry. Recently developed phase field approach for the interaction between PTs and dislocations at large strains and a finite element analysis are utilized. Periodic boundary conditions for displacements are applied to the lateral surfaces. It is confirmed that the shear-induced dislocation pileups may reduce the PT pressure by an order of magnitude in comparison with hydrostatic loading, and even below phase equilibrium pressure, as it ...


Books Published By Métallurgie Extractive Québec, Fathi Habashi 2018 Laval University, Quebec City, Canada

Books Published By Métallurgie Extractive Québec, Fathi Habashi

Fathi Habashi

A condensed catalog of books published by Métallurgie Extractive Québec - - a non-profit publisher devoted to the diffusion of extractive metallurgy literature.


The Positive Role Of Curcumin-Loaded Salmon Nanoliposomes On The Culture Of Primary Cortical Neurons, Mahmoud Hasan, Shahrzad Latifi, Cyril J.F. Kahn, Ali Tamayol, Rouhollah Habibey, Elodie Passeri, Michel Linder, Elmira Arab-Tehrany 2018 Université de Lorraine

The Positive Role Of Curcumin-Loaded Salmon Nanoliposomes On The Culture Of Primary Cortical Neurons, Mahmoud Hasan, Shahrzad Latifi, Cyril J.F. Kahn, Ali Tamayol, Rouhollah Habibey, Elodie Passeri, Michel Linder, Elmira Arab-Tehrany

Mechanical & Materials Engineering Faculty Publications

Curcumin (diferuloylmethane) is a natural bioactive compound with many health-promoting benefits. However, its poor water solubility and bioavailability has limited curcumin’s biomedical application. In the present study, we encapsulated curcumin into liposomes, formed from natural sources (salmon lecithin), and characterized its encapsulation efficiency and release profile. The proposed natural carriers increased the solubility and the bioavailability of curcumin. In addition, various physico-chemical properties of the developed soft nanocarriers with and without curcumin were studied. Nanoliposome-encapsulated curcumin increased the viability and network formation in the culture of primary cortical neurons and decreased the rate of apoptosis.


Numerical Simulation Of Energy Localization In Dynamic Materials, Arkadi Berezovski, Mihhail Berezovski 2018 Tallinn University of Technology

Numerical Simulation Of Energy Localization In Dynamic Materials, Arkadi Berezovski, Mihhail Berezovski

Publications

Dynamic materials are artificially constructed in such a way that they may vary their characteristic properties in space or in time, or both, by an appropriate arrangement or control. These controlled changes in time can be provided by the application of an external (non-mechanical) field, or through a phase transition. In principle, all materials change their properties with time, but very slowly and smoothly. Changes in properties of dynamic materials should be realized in a short or quasi-nil time lapse and over a sufficiently large material region. Wave propagation is a characteristic feature for dynamic materials because it is also ...


Screening Algorithm Based On The Color Halftone Fluorescent Printing And Its Application In Packaging Design, Hu Yaojian, Liu Juan, Wang Ruojing, Zhong Yunfei 2018 Hunan University of Technology

Screening Algorithm Based On The Color Halftone Fluorescent Printing And Its Application In Packaging Design, Hu Yaojian, Liu Juan, Wang Ruojing, Zhong Yunfei

Journal of Applied Packaging Research

Abstract:This paper analyzed the characteristics of colorless fluorescent ink and the existing color separation theory, so that colored additive method should be used in printing color pattern with colorless fluorescent ink as well as three-color screening separation type (red, green and blue). Considering the exhibition of the tone, this paper selected dot parallel screening method. At the same time, through comparing the properties of different dots, this paper adopted a special method of AM screening, using regular triangle as the basic dot model to a threshold matrix of AM screening. Finally, designing a screening algorithm which best suit the ...


Variable Input Observer For State Estimation Of High-Rate Dynamics, Jonathan Hong, Liang Cao, Simon Laflamme, Jacob Dodson 2018 Iowa State University

Variable Input Observer For State Estimation Of High-Rate Dynamics, Jonathan Hong, Liang Cao, Simon Laflamme, Jacob Dodson

Simon Laflamme

High-rate systems operating in the 10 μs to 10 ms timescale are likely to experience damaging effects due to rapid environmental changes (e.g., turbulence, ballistic impact). Some of these systems could benefit from real-time state estimation to enable their full potential. Examples of such systems include blast mitigation strategies, automotive airbag technologies, and hypersonic vehicles. Particular challenges in high-rate state estimation include: 1) complex time varying nonlinearities of system (e.g. noise, uncertainty, and disturbance); 2) rapid environmental changes; 3) requirement of high convergence rate. Here, we propose using a Variable Input Observer (VIO) concept to vary the input ...


Robust Variable Input Observer For Structural Health Monitoring Of Systems Experiencing Harsh Extreme Environments, Jonathan Hong, Liang Cao, Simon Laflamme, Jacob Dodson 2018 Iowa State University

Robust Variable Input Observer For Structural Health Monitoring Of Systems Experiencing Harsh Extreme Environments, Jonathan Hong, Liang Cao, Simon Laflamme, Jacob Dodson

Simon Laflamme

Systems experiencing events in the order of 10μs-10ms timescales, for instance highrate dynamics or harsh extreme environments, may encounter rapid damaging effects. If the structural health of such systems could be accurately estimated in a timely manner, preventative measures could be employed to minimize adverse effects. Previously, a Variable Input Observer (VIO) coupled with a neuro-observer was proposed by the authors as a potential solution in monitoring their structural health. The objective of the VIO is to provide state estimation based on an optimal input space allowed to vary as a function of time. The VIO incorporates the use of ...


Microsecond State Monitoring Of Nonlinear Time-Varying Dynamic Systems, Jacob Dodson, Bryan Joyce, Simon Laflamme, Janet Wolfson 2018 Air Force Research Laboratory

Microsecond State Monitoring Of Nonlinear Time-Varying Dynamic Systems, Jacob Dodson, Bryan Joyce, Simon Laflamme, Janet Wolfson

Simon Laflamme

Reliable operation of next generation high-speed complex structures (e.g. hypersonic air vehicles, space structures, and weapons) relies on the development of microsecond structural health monitoring (μSHM) systems. High amplitude impacts may damage or alter the structure, and therefore change the underlying system configuration and the dynamic response of these systems. While state-of-the-art structural health monitoring (SHM) systems can measure structures which change on the order of seconds to minutes, there are no real-time methods for detection and characterization of damage in the microsecond timescales.

This paper presents preliminary analysis addressing the need for microsecond detection of state and parameter ...


Adaptive Structural Control Using Dynamic Hyperspace, Simon Laflamme 2018 Iowa State University

Adaptive Structural Control Using Dynamic Hyperspace, Simon Laflamme

Simon Laflamme

The design of closed-loop structural control systems necessitates a certain level of robustness to cope with system uncertainties. Neurocontrollers, a type of adaptive control system, have been proposed to cope with those uncertainties. However, the performance of neural networks can be substantially influenced by the choice of the input space, or the hyperspace in which the representation lies. For instance, input selection may influence computation time, adaptation speed, effects of the curse of dimensionality, understanding of the representation, and model complexity. Input space selection is often overlooked in literature, and inputs are traditionally determined offline for an optimized performance of ...


Ureteral Tunnel Length Versus Ureteral Orifice Configuration In The Determination Of Ureterovesical Junction Competence: A Computer Simulation Model, Carlos A. Villanueva, J. Tong, Carl A. Nelson, Linxia Gu 2018 University of Nebraska Medical Center

Ureteral Tunnel Length Versus Ureteral Orifice Configuration In The Determination Of Ureterovesical Junction Competence: A Computer Simulation Model, Carlos A. Villanueva, J. Tong, Carl A. Nelson, Linxia Gu

Mechanical & Materials Engineering Faculty Publications

Introduction The long-held belief that a ureteral re-implant tunnel should be five times the diameter of the ureter, as proposed by Paquin in 1959, ignores the effect of the orifice on the occurrence of reflux. In 1969, Lyon proposed that the shape of the ureteral orifice (UO) is more important than the intravesical tunnel. However, both theories missed quantitative evidence from principles of physics. The goal of the current study was to test Lyon’s theory through numerical models (i.e. to quantify the sensitivity of ureterovesical junction (UVJ) competence to intravesical tunnel length and to the UO).

Materials and ...


Eigenstrain As A Mechanical Set-Point Of Cells, Shengmao Lin, Marsha C. Lampi, Cynthia A. Reinhart-King, Gary C.P. Tsui, Jian Wang, Carl A. Nelson, Linxia Gu 2018 University of Nebraska-Lincoln

Eigenstrain As A Mechanical Set-Point Of Cells, Shengmao Lin, Marsha C. Lampi, Cynthia A. Reinhart-King, Gary C.P. Tsui, Jian Wang, Carl A. Nelson, Linxia Gu

Mechanical & Materials Engineering Faculty Publications

Cell contraction regulates how cells sense their mechanical environment. We sought to identify the set-point of cell contraction, also referred to as tensional homeostasis. In this work, bovine aortic endothelial cells (BAECs), cultured on substrates with different stiffness, were characterized using traction force microscopy (TFM). Numerical models were developed to provide insights into the mechanics of cell–substrate interactions. Cell contraction was modeled as eigenstrain which could induce isometric cell contraction without external forces. The predicted traction stresses matched well with TFM measurements. Furthermore, our numerical model provided cell stress and displacement maps for inspecting the fundamental regulating mechanism of ...


Spot-R By Triax, Purdue ECT Team 2018 Construction Engineering & Management, Purdue University

Spot-R By Triax, Purdue Ect Team

ECT Fact Sheets

Triax’s Spot-r system was developed to tackle the construction industry’s unique safety and productivity challenges, stemming from a demonstrated lack of total jobsite visibility and automatically collected, easily accessible field data. Spot-r by Triax combines a proprietary mesh network with sensor technology to record and transmit previously unattainable workforce and equipment location, activity and safety data within a defined area – all in real-time.

The Spot-r network is installed around the site and operates in a 900 MHz network, with a subset using a cellular connection to forward Spot-r sensor data to Triax’s custom, cloud dashboard. In the ...


Factorial Study On Electrically Conductive Concrete Mix Design For Heated Pavement Systems, Alireza Sassani, Halil Ceylan, Sunghwan Kim, Kasthurirangan Gopalakrishnan, Ali Arabzadeh, Peter Taylor 2018 Iowa State University

Factorial Study On Electrically Conductive Concrete Mix Design For Heated Pavement Systems, Alireza Sassani, Halil Ceylan, Sunghwan Kim, Kasthurirangan Gopalakrishnan, Ali Arabzadeh, Peter Taylor

Halil Ceylan

Application of heated pavement systems is a safer and faster alternative to currently predominant 46 methods of removing ice and snow from paved surfaces. Heated pavements not only can remove 47 ice/snow from pavement surfaces, but are also capable of preventing their 48 formation/accumulation in the first place. Electrically conductive concrete (ECON) provides an 49 effective and powerful means of producing self-heating pavements. The electrical conductivity 50 of ECON is dependent on numerous factors such as type and dosage of electrically conductive 51 materials (ECMs), mix proportions, aggregate type, ECM dispersion, and ionic environment of 52 concrete. Admixtures ...


Mdp (Machine Drive Power) Intelligent Compaction Technology, Purdue ECT Team 2018 Construction Engineering & Management, Purdue University

Mdp (Machine Drive Power) Intelligent Compaction Technology, Purdue Ect Team

ECT Fact Sheets

Caterpillar developed MDP (Machine Drive Power) technology to fill this gap. Rather than an accelerometer and vibratory drum, it uses the principle of rolling resistance to provide indications of soil stiffness. This allows it to perform more reliably on cohesive and granular soils with less variability than accelerometer systems. It also means that the technology can be used on both vibratory and static drum compactors, which are often used on larger sites. While the technology is quite useful on its own, it is even better as a complementary technology to the existing accelerometer-based systems. Contractors who use vibratory soil compactors ...


Purdue’S Biowall, Purdue ECT Team 2018 Construction Engineering & Management, Purdue University

Purdue’S Biowall, Purdue Ect Team

ECT Fact Sheets

Mechanical ventilation, energy recovery ventilation, and infiltration (air that leaks into a building) are commonly used to introduce fresh air. These are all valid approaches, but a living plant-based filter is an innovative complement to these traditional technologies. A Biowall has the potential to improve indoor air quality while reducing the quantity of air needed for ventilation, creating the potential for energy savings. Figure 1 shows a Biowall prototype being evaluated in the ReNEWW House, a research home located near the Purdue University campus (http://www.renewwhouse.com/).


Effects Of Microstructure And Crystallography On Mechanical Properties Of Cold-Rolled Sae1078 Pearlitic Steel, Y. Liu, C. D. Yang, M. Liu, C. H. Wang, Y. C. Dai, X. Li, Alan M. Russell, C. X. Zhang, Z. H. Zhang, G. H. Cao 2018 Shanghai University

Effects Of Microstructure And Crystallography On Mechanical Properties Of Cold-Rolled Sae1078 Pearlitic Steel, Y. Liu, C. D. Yang, M. Liu, C. H. Wang, Y. C. Dai, X. Li, Alan M. Russell, C. X. Zhang, Z. H. Zhang, G. H. Cao

Materials Science and Engineering Publications

The evolution of the microstructure and crystallography in SAE1078 pearlitic steel sheets under different cold-rolling reductions of up to 90% were quantified using transmission electron microscopy (TEM), electron backscatter diffraction (EBSD), and X-ray diffraction (XRD). The mechanical properties were determined by tensile testing at room temperature. TEM analysis showed that the pearlite structure was obviously refined with the interlamellar spacing decreasing to about 57 nm at the rolling reduction of 90%. EBSD investigations indicated that the ferrite exhibited a {001}texture in the 90% cold-rolled pearlitic steel. The dislocations were mainly concentrated during cold rolling between the 10% and 70 ...


Lamb Waves With Conical Dispersion At Zero Wavenumber, David M. Stobbe 2018 University of Colorado at Boulder

Lamb Waves With Conical Dispersion At Zero Wavenumber, David M. Stobbe

Mechanical Engineering Graduate Theses & Dissertations

Lamb waves are guided elastic waves in plates. These waves are dispersive, with the frequency and wavenumber related by the well-known Rayleigh-Lamb equation. Generally, at zero wavenumber the dispersion curves are parabolic and the waves are non-propagating thickness resonances. For distinct values of Poisson’s ratio, however, degeneracy can occur between thickness resonance modes. At these coincidence frequencies the dispersion curves become linear and in a three-dimensional representation the dispersion surface is shaped like a cone. This behavior is referred to as conical dispersion. Waves excited at coincidence frequencies maintain the infinite phase velocity associated with thickness resonances but transport ...


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