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Full-Text Articles in Engineering

Real-Time Identification Of Oxygen Vacancy Centers In Linbo₃ And Srtio₃ During Irradiation With High Energy Particles, Miguel L. Crespillo, Joseph T. Graham, Fernando Agulló-López, Yanwen Zhang, William J. Weber Mar 2021

Real-Time Identification Of Oxygen Vacancy Centers In Linbo₃ And Srtio₃ During Irradiation With High Energy Particles, Miguel L. Crespillo, Joseph T. Graham, Fernando Agulló-López, Yanwen Zhang, William J. Weber

Nuclear Engineering and Radiation Science Faculty Research & Creative Works

Oxygen vacancies are known to play a central role in the optoelectronic properties of oxide perovskites. A detailed description of the exact mechanisms by which oxygen vacancies govern such properties, however, is still quite incomplete. The unambiguous identification of oxygen vacancies has been a subject of intense discussion. Interest in oxygen vacancies is not purely academic. Precise control of oxygen vacancies has potential technological benefits in optoelectronic devices. In this review paper, we focus our attention on the generation of oxygen vacancies by irradiation with high energy particles. Irradiation constitutes an efficient and reliable strategy to introduce, monitor, and characterize …


Geometric Effects Of Open Hollow Hydroxyapatite Microspheres Influence Bone Repair And Regeneration In Sprague Dawley Rats, Youqu Shen, M. N. Rahaman, Yongxian Liu, Yue-Wern Huang Apr 2019

Geometric Effects Of Open Hollow Hydroxyapatite Microspheres Influence Bone Repair And Regeneration In Sprague Dawley Rats, Youqu Shen, M. N. Rahaman, Yongxian Liu, Yue-Wern Huang

Materials Science and Engineering Faculty Research & Creative Works

Effective regeneration of bone defects caused by trauma or chronic diseases is a significant clinical challenge. Bone deficiency is overcome using treatments that rely on bone regeneration and augmentation. While various treatments have been investigated with encouraging results, complete and predictable bone reconstruction is often difficult [1]. Synthetic bone grafts have advantages such as consistent quality, safety, and good tissue tolerance. They usually function as inert or osteoconductive implants. Encouraging results from synthetic grafts have been reported. For instance, hollow hydroxyapatite (HA) microspheres showed the ability to facilitate bone repair in rats with non-healing calvarial defects [2,3]. However, new bone …


Recent Advances On Carrier And Exciton Self-Trapping In Strontium Titanate: Understanding The Luminescence Emissions, Miguel L. Crespillo, Joseph T. Graham, Fernando Agullo-Lopez, Yanwen Zhang, William J. Weber Feb 2019

Recent Advances On Carrier And Exciton Self-Trapping In Strontium Titanate: Understanding The Luminescence Emissions, Miguel L. Crespillo, Joseph T. Graham, Fernando Agullo-Lopez, Yanwen Zhang, William J. Weber

Nuclear Engineering and Radiation Science Faculty Research & Creative Works

An up-to-date review on recent results for self-trapping of free electrons and holes, as well as excitons, in strontium titanate (STO), which gives rise to small polarons and self-trapped excitons (STEs) is presented. Special attention is paid to the role of carrier and exciton self-trapping on the luminescence emissions under a variety of excitation sources with special emphasis on experiments with laser pulses and energetic ion-beams. In spite of the extensive research effort, a definitive identification of such localized states, as well as a suitable understanding of their operative light emission mechanisms, has remained lacking or controversial. However, promising advances …


Optical-Fiber-Based Smart Concrete Thermal Integrity Profiling: An Example Of Concrete Shaft, Ruoyu Zhong, Ruichang Guo, Wen Deng Sep 2018

Optical-Fiber-Based Smart Concrete Thermal Integrity Profiling: An Example Of Concrete Shaft, Ruoyu Zhong, Ruichang Guo, Wen Deng

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Concrete is currently the most widely used construction material in the world. The integrity of concrete during the pouring process could greatly affect its engineering performance. Taking advantage of heat production during the concrete curing process, we propose an optical-fiber-based thermal integrity profiling (TIP) method which can provide a comprehensive and accurate evaluation of the integrity of concrete immediately after its pouring. In this paper, we use concrete shaft as an example to conduct TIP by using the optical fiber as a temperature sensor which can obtain high spatial resolution temperature data. Our method is compared with current thermal infrared …


Development Of Pre-Repair Machining Strategies For Laser-Aided Metallic Component Remanufacturing, Xinchang Zhang, Wenyuan Cui, Leon Hill, Wei Li, Frank W. Liou Aug 2018

Development Of Pre-Repair Machining Strategies For Laser-Aided Metallic Component Remanufacturing, Xinchang Zhang, Wenyuan Cui, Leon Hill, Wei Li, Frank W. Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Remanufacturing worn metallic components can prolong the service life of parts that need frequent replacement but are extremely costly to manufacture, such as aircraft titanium components, casting dies. Additive manufacturing (AM) technology enables the repair of such valuable components by depositing filler materials at the worn area layer by layer to regenerate the missing geometry. In general, damaged parts would be inspected and pre-machined prior to material deposition to remove oil, residue, oxidized layers or defects located in inaccessible regions. Therefore, the motivation of this paper is to introduce pre-repair machining strategies for removing contaminated materials from damaged components and …


The Role Of Ceramic And Glass Science Research In Meeting Societal Challenges: Report From An Nsf-Sponsored Workshop, Katherine T. Faber, Tewodros Asefa, Monika Backhaus-Ricoult, Richard K. Brow, Julie Y. Chan, Shen Dillon, William Fahrenholtz, For Full List Of Authors, See Publisher's Website. May 2017

The Role Of Ceramic And Glass Science Research In Meeting Societal Challenges: Report From An Nsf-Sponsored Workshop, Katherine T. Faber, Tewodros Asefa, Monika Backhaus-Ricoult, Richard K. Brow, Julie Y. Chan, Shen Dillon, William Fahrenholtz, For Full List Of Authors, See Publisher's Website.

Materials Science and Engineering Faculty Research & Creative Works

Under the sponsorship of the U.S. National Science Foundation, a workshop on emerging research opportunities in ceramic and glass science was held in September 2016. Reported here are proceedings of the workshop. The report details eight challenges identified through workshop discussions: Ceramic processing: Programmable design and assembly; The defect genome: Understanding, characterizing, and predicting defects across time and length scales; Functionalizing defects for unprecedented properties; Ceramic flatlands: Defining structure-property relations in free-standing, supported, and confined two-dimensional ceramics; Ceramics in the extreme: Discovery and design strategies; Ceramics in the extreme: Behavior of multimaterial systems; Understanding and exploiting glasses and melts under …


Neutron Irradiation Effects On Domain Wall Mobility And Reversibility In Lead Zirconate Titanate Thin Films, Joseph T. Graham, Geoff L. Brennecka, Paulo Ferreira, Leo Small, David Duquette, Christopher Apblett, Sheldon Landsberger, Jon F. Ihlefeld Mar 2013

Neutron Irradiation Effects On Domain Wall Mobility And Reversibility In Lead Zirconate Titanate Thin Films, Joseph T. Graham, Geoff L. Brennecka, Paulo Ferreira, Leo Small, David Duquette, Christopher Apblett, Sheldon Landsberger, Jon F. Ihlefeld

Nuclear Engineering and Radiation Science Faculty Research & Creative Works

The effects of neutron-induced damage on the ferroelectric properties of thin film lead zirconate titanate (PZT) were investigated. Two sets of PbZr0.52Ti0.48O3 films of varying initial quality were irradiated in a research nuclear reactor up to a maximum 1 MeV equivalent neutron fluence of (5.16± 0.03) x 1015 cm-2. Changes in domain wall mobility and reversibility were characterized by polarization-electric field measurements, Rayleigh analysis, and analysis of first order reversal curves (FORC). With increasing fluence, extrinsic contributions to the small-signal permittivity diminished. Additionally, redistribution of irreversible hysterons towards higher coercive fields was …


A Bist Approach For Configurable Nanofabric Arrays, Mandar V. Joshi, Waleed K. Al-Assadi Aug 2008

A Bist Approach For Configurable Nanofabric Arrays, Mandar V. Joshi, Waleed K. Al-Assadi

Electrical and Computer Engineering Faculty Research & Creative Works

This work proposes a Built-in Self Test (BIST) approach to test crossbars for a defined set of faults. The BIST can classify the different programmable elements in the crossbars as non-defective or defective with a certain fault type. The logic synthesis can then configure the crossbar by avoiding these defective elements.


Defect-Tolerant Gate Macro Mapping & Placement In Clock-Free Nanowire Crossbar Architecture, Ravi Bonam, Yong-Bin Kim, Minsu Choi Sep 2007

Defect-Tolerant Gate Macro Mapping & Placement In Clock-Free Nanowire Crossbar Architecture, Ravi Bonam, Yong-Bin Kim, Minsu Choi

Electrical and Computer Engineering Faculty Research & Creative Works

Recently, we proposed a new clock-free nanowire crossbar architecture based on a delayinsensitive paradigm called Null Convention Logic (NCL). The proposed architecture has simple periodic structure that is suitable for non-deterministic nanoscale assembly and does not require a clock distribution network - so it is intrinsically free from timing-related failure modes. Even though the proposed architecture offers improved manufacturability, it is still not free from defects. This paper elaborates on the different programming techniques to map a given threshold gate macro on a random PGMB (Programmable Gate Macro Block) with predefined dimension. Defect-Aware and Defect Unaware approaches have been considered …


Inherited Redundancy And Configurability Utilization For Repairing Nanowire Crossbars With Clustered Defects, Yadunandana Yellambalase, Minsu Choi, Yong-Bin Kim Oct 2006

Inherited Redundancy And Configurability Utilization For Repairing Nanowire Crossbars With Clustered Defects, Yadunandana Yellambalase, Minsu Choi, Yong-Bin Kim

Electrical and Computer Engineering Faculty Research & Creative Works

With the recent development of nanoscale materials and assembly techniques, it is envisioned to build high-density reconfigurable systems which have never been achieved by the photolithography. Various reconfigurable architectures have been proposed based on nanowire crossbar structure as the primitive building block. Unfortunately, high-density systems consisting of nanometer-scale elements are likely to have many imperfections and variations; thus, defect-tolerance is considered as one of the most exigent challenges. In this paper, we evaluate three different logic mapping algorithms with defect avoidance to circumvent clustered defective crosspoints in nanowire reconfigurable crossbar architectures. The effectiveness of inherited redundancy and configurability utilization is …


Cost-Driven Repair Of A Nanowire Crossbar Architecture, Yadunandana Yellambalase, Shanrui Zhang, Minsu Choi, Nohpill Park, Fabrizio Lombardi Jul 2006

Cost-Driven Repair Of A Nanowire Crossbar Architecture, Yadunandana Yellambalase, Shanrui Zhang, Minsu Choi, Nohpill Park, Fabrizio Lombardi

Electrical and Computer Engineering Faculty Research & Creative Works

The recent development of nanoscale materials and assembly techniques has resulting in the manufacturing of high-density computational systems. These systems consist of nanometer-scale elements and are likely to have many manufacturing imperfections (defects); thus, defect-tolerance is considered as one of the most some algorithms for repairing defective crosspoints in a nanoscale crossbar architecture; furthermore we estimate the efficiency and cost-effectiveness of each algorithm. Also, for a given design and manufacturing environment, we propose a cost-driven method to find a balanced solution by which figures of merit such as area, repair time and reconfiguration cost can be taken into account. Probabilistic …


Real-Time And On-Line Near-Field Microwave Inspection Of Surface Defects In Rolled Steel, R. Zoughi, Christian J. Huber, Nasser N. Qaddoumi, Emarit Ranu, Vladimir Otashevich, Radin Mirshahi, Stoyan I. Ganchev, Thomas Johnson Dec 1997

Real-Time And On-Line Near-Field Microwave Inspection Of Surface Defects In Rolled Steel, R. Zoughi, Christian J. Huber, Nasser N. Qaddoumi, Emarit Ranu, Vladimir Otashevich, Radin Mirshahi, Stoyan I. Ganchev, Thomas Johnson

Electrical and Computer Engineering Faculty Research & Creative Works

The potential and limitations of near-field microwave inspection techniques for detecting various surface defects in rolled steel have been investigated. The focus of this study has been to investigate this potential for tin mill products containing gross and subtle defects including steel induced defects, roll marks, holes, scratches and gouges.


Modeling Of Intra-Cell Defects In Cmos Sram, Waleed K. Al-Assadi, Y. K. Malaiya, A. P. Jayasumana Jan 1993

Modeling Of Intra-Cell Defects In Cmos Sram, Waleed K. Al-Assadi, Y. K. Malaiya, A. P. Jayasumana

Electrical and Computer Engineering Faculty Research & Creative Works

The effect of defects within a single cell of a static random access memory (SRAM) is examined. All major types of faults, including bridging, transistor stuck-open and stuck-on, are examined. A significant fraction of all faults cause high IDDQ values to be observed. Faults leading to inter-cell coupling are identified.