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California Polytechnic State University, San Luis Obispo

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Articles 7171 - 7200 of 7975

Full-Text Articles in Engineering

An Integrated Model For Signalized Traffic Intersection Control, Xiao-Hua Yu Aug 2005

An Integrated Model For Signalized Traffic Intersection Control, Xiao-Hua Yu

Electrical Engineering

Traffic signal control is an effective way to regulate traffic flow to avoid conflict and reduce congestions. This research investigates a real-time traffic signal control system that integrates a traffic flow prediction model and an adaptive control scheme based on dynamic programming with rolling horizon. The proposed approach estimates the parameter of the arriving traffic flow at the intersection, predicts the state transition probabilities, and then formulates the traffic signal control problem as a decision-making problem of a stochastic system. Two different traffic arrival patterns are considered, including the normal distribution and the Poission distribution.

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Experimental Investigation Of The Travel-Time Variance Of An Acoustic Wave Propagating Through The Grid-Generated Turbulence, Tatiana A. Andreeva, William W. Durgin Aug 2005

Experimental Investigation Of The Travel-Time Variance Of An Acoustic Wave Propagating Through The Grid-Generated Turbulence, Tatiana A. Andreeva, William W. Durgin

Office of the Provost Scholarship

An experimental technique for the investigation of the behaviour of acoustic wave propagation through a turbulent medium is discussed. The present study utilizes the ultrasonic travel-time technique to diagnose a grid-generated turbulence. Travel-time variance is studied versus mean flow velocity, travel distance and outer turbulence scale. The effect of thermal fluctuations, which result in fluctuations of sound speed, is studied using a heated-grid experiment. Experimental data obtained using ultrasonic technique confirm numerical and theoretical predictions of nonlinear increase of the travel-time variance with propagation distance, which could be connected to the occurrence of caustics. The effect of turbulent intensity on …

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Evaluation Of Modal And Fema Pushover Procedures Using Strong-Motion Records Of Buildings, Rakesh K. Goel Aug 2005

Evaluation Of Modal And Fema Pushover Procedures Using Strong-Motion Records Of Buildings, Rakesh K. Goel

Civil and Environmental Engineering

The objective of this investigation is to evaluate the FEMA-356 Nonlinear Static Procedure (NSP) and a recently developed Modal Pushover Analysis (MPA) procedure using recorded motions of four buildings that were damaged during the 1994 Northridge earthquake. For this purpose, displacements and drifts from the FEMA-356 NSP and the MPA procedures are compared with the values “derived” from the recorded motions. It is found that the FEMA-356 NSP typically underestimates the drifts in upper stories and overestimates them in lower stories when compared to the recorded motions. Among the four FEMA-356 distributions considered, the “Uniform” distribution led to the most …

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Stability Analysis For Forging Of Porous Bodies, Xuan Wang, Eugene Olevsky, Alain Molinari Jul 2005

Stability Analysis For Forging Of Porous Bodies, Xuan Wang, Eugene Olevsky, Alain Molinari

Industrial and Manufacturing Engineering

The continuum theory of sintering is used for the analysis of the stability of forging of a cylindrical powder specimen. The constitutive properties of the powder material are assumed to follow a power-law creep relationship. Temperature-coupled linear non-uniform stability analyses are carried out. Stability maps are obtained for forging of copper powder components.

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Enhancing Student Learning In Mechanics Through Rapid-Feedback, Jennifer Kadlowec, John Chen, Dexter Whittinghill Jul 2005

Enhancing Student Learning In Mechanics Through Rapid-Feedback, Jennifer Kadlowec, John Chen, Dexter Whittinghill

Mechanical Engineering

In this project our goal is to improve student learning in engineering mechanics courses. The aim to improve learning was accomplished by providing rapid feedback to students of their understanding of key concepts and skills being taught. The feedback system acts as a catalyst to encourage students, working in pairs, to assist each other in correcting misconceptions or deepening each other’s understanding of the concept or skill at hand. Furthermore, the system allows the professor to assess the students’ level of comprehension or misconception in a just-in-time fashion, and thus guide the pace of covering the material. The feedback is …

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The Use Of Rfid In Manufacturing And Packaging Technology Laboratories, Manocher Djassemi, Jay Singh Jun 2005

The Use Of Rfid In Manufacturing And Packaging Technology Laboratories, Manocher Djassemi, Jay Singh

Industrial Technology and Packaging

Mandated use of Radio Frequency Identification (RFID) on goods at pallet, case and item level continues to churn the Consumer Product Goods (CPG), logistics and retail industry. The statement “Internet of things” is slowly becoming true; with concerted efforts from standard setting bodies such as Electronic Product Code (EPC) global, International Standards Organization (ISO), Fast Moving Consumer Goods (FMCG) companies like Gillette, P&G and major retailers like Wal-Mart, TESCO, and the US DoD, to replace barcodes with RFID tags. RFID bridges many areas of manufacturing including inventory management, assembly operation, material handling, packaging and shipping by providing an accurate and …

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Passport To The Materials World: Materials Engineering Outreach Activities, Katherine C. Chen, Lisa Christensen, Amanda Runciman Jun 2005

Passport To The Materials World: Materials Engineering Outreach Activities, Katherine C. Chen, Lisa Christensen, Amanda Runciman

Materials Engineering

No abstract provided.

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The Effectiveness Analysis Of The Online Tools For Engineering Faculty Needs, Ismail Fidan, Jianbiao Pan, Leijun Li Jun 2005

The Effectiveness Analysis Of The Online Tools For Engineering Faculty Needs, Ismail Fidan, Jianbiao Pan, Leijun Li

Industrial and Manufacturing Engineering

As the use of Internet is increasing dramatically, many faculty members are using it in their teaching, research, and services. The Internet also provides faculty easy access to employee benefits and other information. Many universities are using or plan to use online teaching. Lately, many editorial and funding agencies have also started to initiate online review and decision-making system. These systems have eased the burden on both reviewers and agencies. In this study, a survey was prepared and conducted to investigate the effectiveness of the online tools for faculty needs in authors’ institutions and some other United States universities. The …

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A Senior Level Polymer Electronics Course: Unique Instruction Or Just Low Cost?, David Braun Jun 2005

A Senior Level Polymer Electronics Course: Unique Instruction Or Just Low Cost?, David Braun

Electrical Engineering

After progressing from research laboratories to factories to the market, semiconducting polymers now appear in commercial products and offer educational opportunities. Semiconducting polymers are excellent materials with which to teach semiconductor device fabrication principles, device testing, optical and electronic properties, polymer synthesis, polymer film preparation, and structure-property relationships. Previous publications have emphasized multidisciplinary course modules based on semiconducting polymers.1 This work emphasizes how the use of semiconducting polymers in an undergraduate polymer electronics course benefits electrical engineering and computer engineering students.

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System And Method For Differential Data Collection, Jack P. Glas, Vladimir I. Prodanov Jun 2005

System And Method For Differential Data Collection, Jack P. Glas, Vladimir I. Prodanov

Electrical Engineering

The present invention is directed towards a data detector for deriving a data signal from an incoming radio frequency input. The data detector comprises a delay logic which receives an unfiltered signal in quadrature and in-phase components, and applies a delay to each of the in-phase and quadrature phase components of the unfiltered input signal. The detector further comprises a first multiplication logic that multiplies the delayed in-phase component of the unfiltered signal by the quadrature phase component of the unfiltered signal to obtain a first result, and a second multiplication logic that multiplies the delayed quadrature phase component of …

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Weathering Effects On Biodegradation And Toxicity Of Hydrocarbons In Groundwater, Marie G. Dreyer, Yarrow M. Nelson, Christopher L. Kitts Jun 2005

Weathering Effects On Biodegradation And Toxicity Of Hydrocarbons In Groundwater, Marie G. Dreyer, Yarrow M. Nelson, Christopher L. Kitts

Civil and Environmental Engineering

This study examined the effect of weathering on hydrocarbon biodegradation and toxicity at a former oil field near Guadalupe, California. Soil and groundwater at this site contains residual diesel-range hydrocarbons formerly used to dilute the viscous crude oil to facilitate pumping (Lundegard and Garcia, 2001). Natural attenuation is being considered at this site as a means of remediating residual hydrocarbons in soil and groundwater. To provide the lines of evidence required for use of natural attenuation at this site, this research was undertaken to determine if the hydrocarbons continue to be biodegradable after extensive weathering in the field. Observed hydrocarbon …

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Biodegradation Of Weathered Hydrocarbons In Laboratory Microcosms And Soil Columns Simulating Natural Attenuation Field Conditions, C. Robin Cunningham, Yarrow M. Nelson, Paul Lundegard Jun 2005

Biodegradation Of Weathered Hydrocarbons In Laboratory Microcosms And Soil Columns Simulating Natural Attenuation Field Conditions, C. Robin Cunningham, Yarrow M. Nelson, Paul Lundegard

Civil and Environmental Engineering

Abstract of paper presented at conference.

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Microbial Activity Of Soil Following Steam Treatment, Barbara Orchard, Yarrow M. Nelson, Lynne Maloney, Christopher L. Kitts, Paul Lundegard Jun 2005

Microbial Activity Of Soil Following Steam Treatment, Barbara Orchard, Yarrow M. Nelson, Lynne Maloney, Christopher L. Kitts, Paul Lundegard

Civil and Environmental Engineering

The effect of steam treatment on subsurface aerobic and anaerobic microbial communities was investigated using multiple microbial assays. Soil samples were gathered and analyzed prior to, one month after, and eight months after a five-month field pilot test of steam injection and extraction. Aerobic soil samples were analyzed by respirometry, plate counts, and direct microscopic counts. Anaerobic microbial activity was examined by monitoring methane generation in anaerobic microcosms with gas chromatography. Respirometry showed pre-steam CO2 production was consistent with natural attenuation, post-steam (one month) CO2 production was below detection, and post-steam (eight months) CO2 production was about …

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Effect Of Chaos And Stochastics Induced By Internal Waves On Acoustic Wave Propagation, Tatiana A. Andreeva, William W. Durgin Jun 2005

Effect Of Chaos And Stochastics Induced By Internal Waves On Acoustic Wave Propagation, Tatiana A. Andreeva, William W. Durgin

Office of the Provost Scholarship

In the present paper the eikonal equation is considered in the form of a second order, nonlinear ordinary differential equation with harmonic excitation due to internal wave. The harmonic excitation is taken imperfect, i.e. there is a random phase modulation due to Gaussian white noise. The amplitude and wavelength of the acoustic wave are used as the principle signal characteristics in bifurcation analysis. The regions of instability, identified using the bifurcation diagrams, examined through phase diagrams and Poincare maps. The effect of stochastic nature in addition to chaotic one of internal waves is demonstrated by means of comparison of the …

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Design, Fabrication, And Characterization Of An Electrostatically Actuated Microfluidic Valve, Ryan Dale Rivers Jun 2005

Design, Fabrication, And Characterization Of An Electrostatically Actuated Microfluidic Valve, Ryan Dale Rivers

Master's Theses

Microfluidic device construction uses certain critical structures throughout many different applications. The valve structure remains one of the primary structures that present a barrier to miniaturization and portability. The extensive support devices required to power common microfluidic valves remove a significant amount of freedom from microfluidic device design. Moving to electrostatic methods of actuation could reduce the overall footprint of the microfluidic valve. This thesis covers three concept prototypes. Concept I presents an attempt at inlaying gold electrodes into polydimethylsiloxane substrates. Concept II attempts to use liquid silver injected into channels as electrode materials. Concept III uses aluminum sputtering to …

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Improving Safety And Security By Developing A Traffic Accident Prevention System, Mohamed Abdel-Aty, Nizam Uddin, Anurag Pande Jun 2005

Improving Safety And Security By Developing A Traffic Accident Prevention System, Mohamed Abdel-Aty, Nizam Uddin, Anurag Pande

Civil and Environmental Engineering

This research aims at developing accident prediction models to improve freeway safety. Also by reducing incident related congestion on freeways, response and evacuation times would also be reduced in emergency situations. There are considerable amounts of data that are collected and stored for ITS applications. This data includes speed, volume and occupancy provided by loop detectors. Most of these variables are known to be related to accident occurrence and patterns. Previous work has shown the effect of speed variation and volume on traffic safety. In most of the previous work, average or historical speed and volume data have been used. …

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Seismic Response Of Linear And Non-Linear Asymmetric Systems With Non-Linear Fluid Viscous Dampers, Rakesh K. Goel Jun 2005

Seismic Response Of Linear And Non-Linear Asymmetric Systems With Non-Linear Fluid Viscous Dampers, Rakesh K. Goel

Civil and Environmental Engineering

This investigation is concerned with the seismic response of one‐story, one‐way asymmetric linear and non‐linear systems with non‐linear fluid viscous dampers. The seismic responses are computed for a suite of 20 ground motions developed for the SAC studies and the median values examined. Reviewed first is the behaviour of single‐degree‐of‐freedom systems to harmonic and earthquake loading. The presented results for harmonic loading are used to explain a few peculiar trends—such as reduction in deformation and increase in damper force of short‐period systems with increasing damper non‐linearity—for earthquake loading. Subsequently, the seismic responses of linear and non‐linear asymmetric‐plan systems with non‐linear …

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Sequential Deposition Of Copper/Alumina Composites, X. Wang, J. Ma, A. Maximenko, E.A. Olevsky, M.B. Stern, B.M. Guenin Jun 2005

Sequential Deposition Of Copper/Alumina Composites, X. Wang, J. Ma, A. Maximenko, E.A. Olevsky, M.B. Stern, B.M. Guenin

Industrial and Manufacturing Engineering

No abstract provided.

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Technology And You: Working With The Aerospace Industry To Enhance Engineering Education, Russell M. Cummings, John H. Mcmasters Jun 2005

Technology And You: Working With The Aerospace Industry To Enhance Engineering Education, Russell M. Cummings, John H. Mcmasters

Aerospace Engineering

While many engineers in the aerospace engineering profession know that interacting with students is a good idea, few of them know how to do it. Certainly some engineers are asked on occasion to give lectures at various university club meetings, and some are even heavily involved in interacting with students working on various design projects, but the average engineer has little or no interaction with students over the course of their career. A number of companies, including Boeing, have created technical interest groups to encourage mentoring and sharing of corporate knowledge throughout the company. These efforts have been met with …

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A Cartilage Growth Mixture Model For Infinitesimal Strains: Solutions Of Boundary-Value Problems Related To In Vitro Growth Experiments, Stephen M. Klisch, Robert L. Sah, Anne Hoger Jun 2005

A Cartilage Growth Mixture Model For Infinitesimal Strains: Solutions Of Boundary-Value Problems Related To In Vitro Growth Experiments, Stephen M. Klisch, Robert L. Sah, Anne Hoger

Mechanical Engineering

A cartilage growth mixture (CGM) model is linearized for infinitesimal elastic and growth strains. Parametric studies for equilibrium and nonequilibrium boundary-value problems representing the in vitro growth of cylindrical cartilage constructs are solved. The results show that the CGM model is capable of describing the main biomechanical features of cartilage growth. The solutions to the equilibrium problems reveal that tissue composition, constituent pre-stresses, and geometry depend on collagen remodeling activity, growth symmetry, and differential growth. Also, nonhomogeneous growth leads to nonhomogeneous tissue composition and constituent pre-stresses. The solution to the nonequilibrium problem reveals that the tissue is nearly in equilibrium …

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Pnl Applied To Economics, Barbara Diaz, Tomohiro Takagi, Sema E. Alptekin May 2005

Pnl Applied To Economics, Barbara Diaz, Tomohiro Takagi, Sema E. Alptekin

Industrial and Manufacturing Engineering

This work is a continuation of Zadeh’s research on Precisiated Natural language. Precisiated Natural Language (PNL) provides a system for computation and deduction of propositions expressed in a natural language. The importance of PNL for economics is discussed. The improved process of PNL is presented using a real world example from economics.

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Determination Of Surface And Thickness Characteristics Of Textured Geomembranes Using Image Analysis, Nazli Yesiller, Arif Cekic May 2005

Determination Of Surface And Thickness Characteristics Of Textured Geomembranes Using Image Analysis, Nazli Yesiller, Arif Cekic

Civil and Environmental Engineering

Image analysis was used to determine surface topography and thickness of textured geomembranes. Images of cross sections (specimen length × thickness) of geomembranes were obtained at 50× magnification using a digital optical microscope. Thickness was determined as the distance between the top and bottom surfaces along an entire cross section. For surface analysis, profiles of top and bottom surfaces were extracted from the cross section images. Amplitude, spatial, hybrid, and functional texture parameters were determined. Tests were conducted on eleven samples of HDPE and LLDPE geomembranes manufactured by co-extrusion and embossing at varying thicknesses. The geomembranes were classified into three …

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Prevention Of Atrophic Nonunion Development By Recombinant Human Bone Morphogenetic Protein-7, Takeshi Makino, David J. Hak, Scott Hazelwood, Shane Curtiss, A. Hari Reddi May 2005

Prevention Of Atrophic Nonunion Development By Recombinant Human Bone Morphogenetic Protein-7, Takeshi Makino, David J. Hak, Scott Hazelwood, Shane Curtiss, A. Hari Reddi

Biomedical Engineering

Severe periosteal and soft tissue disruption at the time of fracture may result in the formation of an atrophic nonunion. We have developed a reproducible atrophic nonunion in an animal model. The purpose of this study was to evaluate whether the immediate application of recombinant human BMP-7 to the fracture site could rescue the healing process in this nonunion model. A total of 56 three month old Fisher 344 rats were utilized. A 1.25mm diameter K-wire was inserted into the femur in a retrograde fashion, and a mid-diaphyseal closed transverse fracture was created using a standard three point bending device. …

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Sensitivity And Uncertainty Analysis Coupled With Automatic Calibration For A Distributed Watershed Model, Misgana K. Muleta, John W. Nicklow May 2005

Sensitivity And Uncertainty Analysis Coupled With Automatic Calibration For A Distributed Watershed Model, Misgana K. Muleta, John W. Nicklow

Civil and Environmental Engineering

Distributed watershed models should pass through a careful calibration procedure before they are utilized as a decision making aid in the planning and management of water resources. Although manual approaches are still frequently used for calibration, they are tedious, time consuming, and require experienced personnel. This paper describes an automatic approach for calibrating daily streamflow and daily sediment concentration values estimated by the US Department of Agriculture’s distributed watershed simulation model, Soil and Water Assessment Tool (SWAT). The automatic calibration methodology applies a hierarchy of three techniques, namely screening, parameterization, and parameter sensitivity analysis, at the parameter identification stage of …

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A Simulation Analysis Of Factors Influencing The Flexibility Of Cellular Manufacturing, Manocher Djassemi May 2005

A Simulation Analysis Of Factors Influencing The Flexibility Of Cellular Manufacturing, Manocher Djassemi

Industrial Technology and Packaging

The performance of cellular manufacturing (CM) systems in a variable demand and flexible workforce environment has been examined using simulation modelling. Discrepancies between academicians and practitioners' findings with respect to flexibility and uneven machine utilization in CM systems are discussed. The views of two parties were incorporated in simulation models to rectify the existing discrepancies. While the results of this study confirm the previous findings of academicians regarding the deterioration of the performance of CM in a variable product mix situation, it appears that those results may be significantly influenced by considering a flexible workforce. The simulation results show that …

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Visible Light Emitting Diodes Fabricated From Soluble Semiconducting Polymers, Alan J. Heeger, David Braun Apr 2005

Visible Light Emitting Diodes Fabricated From Soluble Semiconducting Polymers, Alan J. Heeger, David Braun

Electrical Engineering

Visible light LEDs are produced having a layer of conjugated polymer which is cast directly from solution or formed as a gel-processed admixture with a carrier polymer. The LEDs can be formed so as to emit polarized light.

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Fabrication And Composition Control Of Niti Shape Memory Thin Films For Microactuators, Richard N. Savage, David J. Getchel Apr 2005

Fabrication And Composition Control Of Niti Shape Memory Thin Films For Microactuators, Richard N. Savage, David J. Getchel

Materials Engineering

Microactuators fabricated with NiTi thin films take advantage of this material’s large energy density (~5-10 joules/cm3) and high strain recovery (~8%). Microelectromechanical Systems (MEMS) devices designed with these actuators can serve as biosensors, micro-fluidic pumps or optical switches. However, the fundamental mechanical properties stemming from the crystalline structure of these shape memory NiTi films have not been fully characterized with MEMS scale test structures. Understanding the relationship of crystalline structure, film stoichiometry, and phase transformation temperatures is crucial when designing a MEMS actuator. In addition, force displacement curves for both the martensite and austenite phases of NiTi are necessary to …

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Non-Standard Structure Flow Measurement Evaluation Using The Flow Rate Indexing Procedure – Qip, Stuart Styles Apr 2005

Non-Standard Structure Flow Measurement Evaluation Using The Flow Rate Indexing Procedure – Qip, Stuart Styles

BioResource and Agricultural Engineering

This paper summarizes the results of a performance evaluation using advanced hydroacoustic rating techniques in irrigation canal systems. Standardized field-tested procedures and technical specifications for index velocity ratings have been developed for rating measurement locations using hydroacoustic flow meters. Water managers and users of advanced electronic flow measuring devices can improve the cost effectiveness, accuracy, and quality control of discharge records, even at sites with complex flow conditions, by observing these recommended guidelines.

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Non-Standard Structure Flow Measurement Evaluation Using The Flow Rate Indexing Procedure - Qip, Stuart W. Styles Mar 2005

Non-Standard Structure Flow Measurement Evaluation Using The Flow Rate Indexing Procedure - Qip, Stuart W. Styles

BioResource and Agricultural Engineering

This paper summarizes the results of a performance evaluation using advanced hydroacoustic rating techniques in irrigation canal systems. Standardized field-tested procedures and technical specifications for index velocity ratings have been developed for rating measurement locations using hydroacoustic flow meters. Water managers and users of advanced electronic flow measuring devices can improve the cost effectiveness, accuracy, and quality control of discharge records, even at sites with complex flow conditions, by observing these recommended guidelines.

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Characterization Of Crack Propagation During Sonic Ir Inspection, Jacob Kephart, John Chen, Hong Zhang Mar 2005

Characterization Of Crack Propagation During Sonic Ir Inspection, Jacob Kephart, John Chen, Hong Zhang

Mechanical Engineering

Sonic IR is an emerging, thermal-based, nondestructive evaluation (NDE) technique. Typically a short burst of high power acoustical energy is injected into an object being studied and certain types of defects heat up and is detected using a thermal imaging camera. This inspection technique is very fast, lasting only a few seconds for total inspection time. However due to many uncertainties in the inspection process it has yet to be adopted widely by industry. There are many unknown parameters governing sonic IR, which need to be understood before it becomes a widely used NDE technique. This paper shows that under …

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