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Full-Text Articles in Architecture

Model For Reinforced Concrete Members Under Torsion, Bending, And Shear. Ii: Model Application And Validation, Gary Greene, Abdeldjelil Belarbi Aug 2009

Model For Reinforced Concrete Members Under Torsion, Bending, And Shear. Ii: Model Application And Validation, Gary Greene, Abdeldjelil Belarbi

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

A model was recently proposed for predicting the load-deformation response of a reinforced concrete member under torsion combined with bending and shear to spalling or ultimate. This paper shows the application of the model to create interaction surfaces to predict the failure of a member subjected to different ratios of applied torsion, bending, and shear. the model was validated by comparing the predicted and experimental behavior of 28 members from three experimental studies available in the literature. the members were loaded under torsion combined with different ratios of bending, and shear. the torque-twist behavior, reinforcement stress, and concrete surface strain …


Lignin And Lipid Impact On Sorption And Diffusion Of Trichloroethylene In Tree Branches For Determining Contaminant Fate During Plant Sampling And Phytoremediation, Gayathri Gopalakrishnan, Joel Gerard Burken, Charles J. Werth Aug 2009

Lignin And Lipid Impact On Sorption And Diffusion Of Trichloroethylene In Tree Branches For Determining Contaminant Fate During Plant Sampling And Phytoremediation, Gayathri Gopalakrishnan, Joel Gerard Burken, Charles J. Werth

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Plants Draw All They Need from their Surrounding Environment and in Doing So Also Draw Anthropogenic Contaminants from their Surroundings. Several Natural Processes (E.g., Active Transport, Diffusion, Sorption, and Degradation) Occur within Trees and Affect Chemical Concentrations in Tree Samples. This Study Elucidates Tree Contaminant Chemical Interactions on Equilibrium Sorption and Diffusion into Branch Tissue (I.e., Wood Core and Bark), Specifically the Impacts of Lipid and Lignin Content. Five Tree Species Were Selected to Span a Range of Lignin and Lipid Contents. Linear Isotherms Were Obtained for All Sampled Species over a Limited Concentration Range (2 Μg/ ML < C Gas < 12 Μg/mL), and Equilibrium Distribution Coefficients (Kd) Were Linearly Correlated to Lipid (R2 > 0.83) But …


Conference Review - 4th International Phytotechnologies Conference, Denver, Co, September 24-26, 2007, Jason C. White, Joel G. (Gerard) Burken Jul 2009

Conference Review - 4th International Phytotechnologies Conference, Denver, Co, September 24-26, 2007, Jason C. White, Joel G. (Gerard) Burken

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

No abstract provided.


Why Is Fresh Self-Compacting Concrete Shear Thickening?, Dimitri Feys, Ronny Verhoeven, Geert De Schutter Jun 2009

Why Is Fresh Self-Compacting Concrete Shear Thickening?, Dimitri Feys, Ronny Verhoeven, Geert De Schutter

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The Rheological Properties of Fresh Concrete Are Mostly Described by Means of the Bingham Model. for Self-Compacting Concrete, the Bingham Model is Applicable in a Lot of Cases, But Some Authors Report that the Rheological Behavior is Non-Linear. the Apparent Viscosity Increases with Increasing Shear Rate and the SCC Shows Shear Thickening Behavior. Shear Thickening Becomes Important in Operations Occurring at High Shear Rates, Like Mixing and Pumping. in These Cases, Shear Thickening Should Not Be Forgotten in Order to Avoid Breaking of the Mixer, Pump or Pipes. This Paper Will Describe Two Possible Theories for Shear Thickening Behavior of …


Integration Approach Of The Couette Inverse Problem Of Powder Type Self-Compacting Concrete In A Wide-Gap Concentric Cylinder Rheometer. Part Ii. Influence Of Mineral Additions And Chemical Admixtures On The Shear Thickening Flow Behaviour, G. Heirman, R. Hendrickx, L. Vandewalle, D. Van Gemert, D. (Dimitri) Feys, G. De Schutter, B. Desmet, J. Vantomme Mar 2009

Integration Approach Of The Couette Inverse Problem Of Powder Type Self-Compacting Concrete In A Wide-Gap Concentric Cylinder Rheometer. Part Ii. Influence Of Mineral Additions And Chemical Admixtures On The Shear Thickening Flow Behaviour, G. Heirman, R. Hendrickx, L. Vandewalle, D. Van Gemert, D. (Dimitri) Feys, G. De Schutter, B. Desmet, J. Vantomme

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The Influence of Mineral Additions and Chemical Admixtures on the Shear Thickening Flow Behavior of Powder Type Self-Compacting Concrete (SCC) is Studied by Means of a Wide-Gap Concentric Cylinder Rheometer. the Couette Inverse Problem is Treated by Means of the Integration Method in Order to Derive the Flow Curve Τ(Γ̇) from the Torque Measurements. According to the Experimental Results, the Shear Thickening Effect is Found to Be Strongly Influenced by the Addition of the Chemical Admixture (A Polycarboxylate Ether based Superplasticizer), Whereas Mineral Additions Were Found to Modify the Intensity of Shear Thickening. the Limestone, Quartzite and Fly Ash Addition …


Taproot™ Technology: Tree Coring For Fast, Noninvasive Plume Delineations, Joel Gerard Burken, Sallie Bailey, Matt Shurtliff, Jeff Mcdermott Jan 2009

Taproot™ Technology: Tree Coring For Fast, Noninvasive Plume Delineations, Joel Gerard Burken, Sallie Bailey, Matt Shurtliff, Jeff Mcdermott

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In Efforts to Evaluate the Use of Plants as a Forensic Tool for Delineating Contaminated Soil and Groundwater, a Laboratory Experiment and a Field Sampling Effort Were Undertaken. Site Assessments Are Often Costly and Inaccurate, Requiring Multiple Mobilizations to Hone in on Source Areas and Getting Accurate Estimates of Contaminant Extent and Distribution. as These Extensive Site Delineations Take Place, Valuable Time and Resources Are Lost. the Findings of This Study Show that Plants Can Be Used as a Tool to Evaluate a Variety of Subsurface Contaminants, Either in the Vadose Zone or in the Saturated Zone. in the First …


Predicting The Perforation Response Of Honeycomb Sandwich Panels Using Ballistic Limit Equations, William P. Schonberg, Frank Schäfer, Robin Putzar Jan 2009

Predicting The Perforation Response Of Honeycomb Sandwich Panels Using Ballistic Limit Equations, William P. Schonberg, Frank Schäfer, Robin Putzar

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Man-made debris from previous spacecraft missions poses a serious threat to spacecraft that are launched to operate in Earth orbit because it can strike such spacecraft at extremely high velocities and consequently damage mission-critical systems. Most satellites are constructed with honeycomb sandwich panels as their primary structural elements. to be able to perform a risk analysis, it is important to know, in the event of such a meteoroid or orbital debris particle impact, whether or not the impacting particle or parts thereof will exit the rear of the sandwich panel. a recently developed set of ballistic limit equations for two …


Risk Indexes For Draft Ccl3 Chemicals, J. Alan Roberson, Matthew Lueders, Craig Adams, Jeffrey S. Rosen Jan 2009

Risk Indexes For Draft Ccl3 Chemicals, J. Alan Roberson, Matthew Lueders, Craig Adams, Jeffrey S. Rosen

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

To supplement the processes used for developing the draft third Contaminant Candidate List (CCL3) and better inform decisions made by the US Environmental Protection Agency on future CCLs, the authors offer an evaluation tool for efficiently synthesizing, visualizing, and organizing data for effective comparisons among contaminants. Graphical presentations of health effects-occurrence indexes were developed for more than 300 chemical contaminants, including those on the draft CCL3. a risk indexes framework was then used to elucidate the extent of available data, the data quality, and the underlying uncertainties for occurrence and toxicity. Choosing the appropriate contaminant for regulation is a complex …


Liquefaction Behavior Of Mississippi River Silts, Ali M. Izadi, Ronaldo Luna, Richard Wesley Stephenson Dec 2008

Liquefaction Behavior Of Mississippi River Silts, Ali M. Izadi, Ronaldo Luna, Richard Wesley Stephenson

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Civil Infrastructure Built on Alluviums and Recent Deposits, Such as Dams, Contain Significant Amount of Silts. the Static and Dynamic Behavior of These Fine-Grained Soils Has Been Investigated Less Than the Clay-Like or Sand-Like Soils. Low Plasticity Silts (PI = 6) Obtained East of St. Louis in Illinois Are Known as Loess that Has Been Re-Deposited by Water in the Floodplains of the Mississippi River. These Silts Were Reconstituted in the Laboratory by Slurry at Water Content above the Liquid Limit and Then Consolidated to an Initial Effective Stress. the Initial Laboratory Characterization under Monotonic Loading Included a Series of …


Piles Under Earthquake Loads, Shamsher Prakash, Vijay K. Puri Dec 2008

Piles Under Earthquake Loads, Shamsher Prakash, Vijay K. Puri

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Piles are preferred type of foundation for supporting structures in seismic areas. their performance is affected by soil, pile and earthquake related parameters. in non-liquefying soils, the shear modulus may degrade, and material damping may increase with increasing strain/displacement. in liquefying soils, the lateral ground displacement may lead to increased lateral loads and moments on the pile leading to pile failure in bending. the loss of lateral support can also lead to buckling type failure. These issues for pile design in seismic areas are examined. © 2008 ASCE.


Fresh Self Compacting Concrete, A Shear Thickening Material, Dimitri Feys, Ronny Verhoeven, Geert De Schutter Jul 2008

Fresh Self Compacting Concrete, A Shear Thickening Material, Dimitri Feys, Ronny Verhoeven, Geert De Schutter

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In Literature, the Rheological Properties of Concrete Have Been Investigated Thoroughly, resulting in a Simple Description, in Steady State, by Means of the Bingham Model. Self-Compacting Concrete Shows a Lower Yield Stress, Which in Some Cases is Very Close to Zero, or Can Even Appear to Be Negative When Extrapolating the Bingham Model. in the Latter Case, the Bingham Model is Not Valid and Other Solutions Must Be Found. in This Paper, the Non-Linearity - or Shear Thickening - in the Rheological Behavior of Fresh SCC is Described with the Modified Bingham Model, after the Elimination of Possible Measurement Artefacts. …


Effects Of Ionic Strength, Temperature, And Ph On Degradation Of Selected Antibiotics, Keith A. Loftin, Craig D. Adams, Michael T. Meyer, Rao Surampalli Mar 2008

Effects Of Ionic Strength, Temperature, And Ph On Degradation Of Selected Antibiotics, Keith A. Loftin, Craig D. Adams, Michael T. Meyer, Rao Surampalli

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Aqueous degradation rates, which include hydrolysis and epimerization, for chlorretracycline (CTC), oxytetracycline (OTC), tetracycline (TET), lincomycin (LNC), sulfachlorpyridazine (SCP), sulfadimethoxine (SDM), sulfathiazole (STZ), trimethoprim (TRM), and tylosin a (TYL) were studied as a function of ionic strength (0.0015, 0.050, or 0.084 mg/L as Na2HPO4), temperature (7, 22, and 35°C), and pH (2, 5, 7, 9, and 11). Multiple linear regression revealed that ionic strength did not significantly affect (α = 0.05) degradation rates for all compounds, but temperature and pH affected rates for CTC, OTC, and TET significand (α = 0.05). Degradation also was observed for TYL at pH 2 …


Review Of Design Guidelines For Frp Confinement Of Reinforced Concrete Columns Of Noncircular Cross Sections, Silvia Rocca, Nestore Galati, Antonio Nanni Jan 2008

Review Of Design Guidelines For Frp Confinement Of Reinforced Concrete Columns Of Noncircular Cross Sections, Silvia Rocca, Nestore Galati, Antonio Nanni

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Current international design guidelines provide predictive design equations for the strengthening of reinforced concrete (RC) columns of both circular and prismatic cross sections by means of fiber-reinforced polymer (FRP) confinement and subjected to pure axial loading. Extensive studies (experimental and analytical) have been conducted on columns with circular cross sections, and limited studies have been conducted on members with noncircular cross sections. in fact, the majority of available research work has been on small-scale, plain concrete specimens. in this review paper, four design guidelines are introduced, and a comparative study is presented. This study is based on the increment of …


Extension Of The Poiseuille Formula For Shear-Thickening Materials And Application To Self-Compacting Concrete, Dimitri Feys, Ronny Verhoeven, Geert De Schutter Jan 2008

Extension Of The Poiseuille Formula For Shear-Thickening Materials And Application To Self-Compacting Concrete, Dimitri Feys, Ronny Verhoeven, Geert De Schutter

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In Practice, While Placing Concrete in a Formwork by Pumping, the Pressure Generated by the Pump is Not Controlled. in Order to Enhance the Safety on the Worksite, and in View of the Current Economic and Ecologic Arguments, It Would Be Useful to Dispose of an Equation Able to Predict Pressure Losses based on the Rheological Properties of the Concrete and the Pipe Configuration. This Paper Describes the Derivation of an Extended Version of the Poiseuille Formula, for Shear-Thickening Materials with a Yields Stress, Described by the Modified Bingham Equation. This Formula is Applied to Flow-Tests with Self-Compacting Concrete. the …


Kinetics And Reaction Products Of Ozone And Surface-Bound Squalene, J. R. Wells, Glenn Morrison, Beverly K. Coleman Jan 2008

Kinetics And Reaction Products Of Ozone And Surface-Bound Squalene, J. R. Wells, Glenn Morrison, Beverly K. Coleman

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Because of the high occupant density in aircraft, the surface chemistry of ozone and squalene, an important component of skin oil, was evaluated. a reaction probability of 45±14) x 10 -5 was determined for the reaction of squalene (2,6,10,15,19,23-hexamethyl-2,6,10,14,18,22- tetracosahexaene) with ozone (50 parts per billion (ppb)) on a glass plate surface using the Field and Laboratory Emission Cell (FLEC) Automation and Control System (FACS). to more clearly define part of squalene's indoor environment degradation mechanism, gas-phase and surface-bound products of the squalene+O3 reaction were also investigated. Emitted products were captured in solution, derivatized with O-(2,3,4,5,6pentafluorobenzyl) hydroxylamine (PFBHA), and analyzed …


Modeling The Fate Of Pharmaceuticals And Personal Care Products In Sewage Treatment Plants, Craig D. Adams Jan 2008

Modeling The Fate Of Pharmaceuticals And Personal Care Products In Sewage Treatment Plants, Craig D. Adams

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Chemical fate models can be used to estimate the transformation reactions and the partitioning behavior of pharmaceuticals and personal care products (PPCPs) in sewage treatment plants (STPs). Modeling the fate of PPCPs in a STP requires parameters such as rate constants or partition coefficients that are often unique to a specific STP, and that may exhibit significant temporal variability. Chemical fate models provide both a valuable test of our understanding of the fundamental underlying mechanisms regarding the fate of PPCPs in STPs, as well as a means of providing both qualitative and quantitative estimates for PPCP removal. This paper is …


Sustainable Lunar Habitat Protection Against Damage By Meteoroid Impacts, William P. Schonberg, Robin Putzar, Frank Schaefer Jan 2008

Sustainable Lunar Habitat Protection Against Damage By Meteoroid Impacts, William P. Schonberg, Robin Putzar, Frank Schaefer

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Sustainability is a key consideration in the design and establishment of human habitats on the Moon (and on Mars as well). One hazard faced by such habitats is the damage that can be caused by the impact of a meteoroid on a critical habitat structure or structural component. in this paper we discuss various approaches to meteoroid shielding for lunar habitats, focusing on approaches that use resources mined or extracted from the moon. Advantages and disadvantages of these various techniques are also presented and discussed. the Moon's mineralogy is highlighted, and suggestions are presented for materials that can be used …


Forecasting Model For Air Taxi, Commercial Airline, And Automobile Demand In The United States, Hojong Baik, Antonio A. Trani, Nicolas Hinze, Howard Swingle, Senanu Ashiabor, Anand Seshadri Jan 2008

Forecasting Model For Air Taxi, Commercial Airline, And Automobile Demand In The United States, Hojong Baik, Antonio A. Trani, Nicolas Hinze, Howard Swingle, Senanu Ashiabor, Anand Seshadri

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

A nationwide model predicts the annual county-to-county person roundtrips for air taxi, commercial airline, and automobile at 1-year intervals through 2030. the transportation systems analysis model (TSAM) uses the four-step transportation systems modeling process to calculate trip generation, trip distribution, and mode choice for each county origin-destination pair. Network assignment is formulated for commercial airline and air taxi demand. TSAM classifies trip rates by trip purpose, household income group, and type of metropolitan statistical area from which the round-trip started. a graphical user interface with geographic information systems capability is included in the model. Potential applications of the model are …


Round-Robin Testing Of A Dewpoint Potentiameter Versus Filter Paper To Determine Total Suction, Thomas M. Petry, Cheng Ping Jiang Sep 2007

Round-Robin Testing Of A Dewpoint Potentiameter Versus Filter Paper To Determine Total Suction, Thomas M. Petry, Cheng Ping Jiang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Expansive clays exhibit high potential for volume change when changes in soil moisture occur. It has been estimated that the annual cost of damage to facilities built on expansive clay in the United States exceeds $9 billion. the use of soil suction measurements to predict potential clay volume changes has shown significant promise, yet the currently utilized method to determine soil suction, the filter paper method, has serious drawbacks. First, the test takes approximately 8 days to complete, making it less than practical for broad use by practicing engineers. Second, and more troublesome, the filter paper test is difficult to …


Foundations For Seismic Loads, Vijay K. Puri, Shamsher Prakash Sep 2007

Foundations For Seismic Loads, Vijay K. Puri, Shamsher Prakash

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Design of foundations in earthquake prone areas needs special considerations. Shallow foundations may experience a reduction in bearing capacity and increase in settlement and tilt due to seismic loading. the reduction in bearing capacity depends on the nature and type of soil and ground acceleration parameters. in the case of piles, the soil-pile behavior under earthquake loading is generally non-linear. the nonlinearity must be accounted for by defining soil-pile stiffness in terms of strain dependent soil modulus. Several behavioral and design aspects of shallow foundations and pile groups subjected to earthquakes have been critically reviewed. Copyright ASCE 2007.


Strengthening Of A Reinforced Concrete Bridge With Externally Bonded Steel Reinforced Polymer (Srp), Alexis Lopez, Nestore Galati, Tarek Alkhrdaji, Antonio Nanni Jun 2007

Strengthening Of A Reinforced Concrete Bridge With Externally Bonded Steel Reinforced Polymer (Srp), Alexis Lopez, Nestore Galati, Tarek Alkhrdaji, Antonio Nanni

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This paper introduces steel reinforced polymer (SRP) as a way to strengthen civil structures. This technique consists of cords formed by interwoven high-strength steel wires embedded within a polymeric resin. a comprehensive study addressing analysis, design, installation, load rating and monitoring of a bridge strengthened with this technology is reported. the SRP system was easily installed, demonstrating its similarity to more traditional fiber reinforced polymer (FRP) strengthening techniques. Load tests were performed to evaluate the bridge structural behavior prior and after the strengthening in accordance with AASHTO specifications, showing that the rehabilitation performed as predicted and therefore created the possibility …


Durability Performance Of Polyurea Confined Concrete Cylinders, Matthew Beyer May 2007

Durability Performance Of Polyurea Confined Concrete Cylinders, Matthew Beyer

Opportunities for Undergraduate Research Experience Program (OURE)

No abstract provided.


Analysis Of Vertical Takeoff And Landing (Vtol) Unmanned Aerial Vehicles (Ua V) With Emphasis On Tilt Duct And Tilt Rotor Systems, Devin Boyle Mar 2007

Analysis Of Vertical Takeoff And Landing (Vtol) Unmanned Aerial Vehicles (Ua V) With Emphasis On Tilt Duct And Tilt Rotor Systems, Devin Boyle

Opportunities for Undergraduate Research Experience Program (OURE)

No abstract provided.


The Use Of Thermoelectric Peltiers To Recapture Waste Heat, Navarre Bartz Mar 2007

The Use Of Thermoelectric Peltiers To Recapture Waste Heat, Navarre Bartz

Opportunities for Undergraduate Research Experience Program (OURE)

Peltier devices are a method of converting differences in temperature into electrical energy. Using data from a supplier of these devices, calculations were made to determine the efficiency of these devices in conjunction with a residential solar hybrid electric system. The initial calculations show efficiencies less than 2% with the temperature differences experienced during the springtime. While this efficiency doesn't sound stellar, taking into account the current efficiency of residential solar cells, this would be an appreciable addition to the power output of a residential solar system.


Damage Detection In Ambient Vibration Using Proportional Flexibility Matrix With Incomplete Measured Dofs, Zhongdong Duan, Guirong Yan, Jinping Ou, Billie F. Spencer Mar 2007

Damage Detection In Ambient Vibration Using Proportional Flexibility Matrix With Incomplete Measured Dofs, Zhongdong Duan, Guirong Yan, Jinping Ou, Billie F. Spencer

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Structural Damage Detections based on the Changes of Dynamic Properties Are a Major Concern Tor Structural Health Monitoring. in This Paper. Efforts Are Made to Extend the Flexibility-Based Damage Localization Methods, Especially the Damage Locating Vector (DLV) Method, to the Case of Ambient Vibration with Incomplete Measured Degree of Freedom, Where Flexibility Matrices Are Not Available. First, the Method to Assemble a Proportional Flexibility Matrix (PFM) with Arbitrarily Scaled Modal Shapes of Full Measured Degrees of Freedom (DOF) is Introduced. the PFM is within a Scalar Multiplier to the Real Flexibility Matrix, and the Multiplier is Shown to Be the …


Evaluation Of Time Independent Rheological Models Applicable To Fresh Self-Compacting Concrete, Dimitri Feys, Ronny Verhoeven, Geert De Schutter Jan 2007

Evaluation Of Time Independent Rheological Models Applicable To Fresh Self-Compacting Concrete, Dimitri Feys, Ronny Verhoeven, Geert De Schutter

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Self-Compacting Concrete is a New Type of Concrete Which is More Liquid Compared to Traditional Concrete and Which Does Not Need Any Form of External Compaction. as a Result, This Type of Concrete is Suitable for a New Placing Technique: Pumping SCC from the Bottom in the Formwork and Letting It Rise in the Formwork Due to the Applied Pressure. in Order to Understand the Phenomena Occurring during Pumping Operations, the Rheological Properties of SCC Must Be Investigated and Controlled. Tests Have Been Performed with Two Different Rheometers, Which Are Described in This Paper. for the Tattersall MIk-II Rheometer, a …


Nondestructive Evaluation Of Rc Structures Strengthened With Frp Laminates Containing Near-Surface Defects In The Form Of Delaminations, Mahmut Ekenel, John J. Myers Jan 2007

Nondestructive Evaluation Of Rc Structures Strengthened With Frp Laminates Containing Near-Surface Defects In The Form Of Delaminations, Mahmut Ekenel, John J. Myers

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Fiber reinforced polymer (FRP) composites are being utilized in a wide range of application areas in structural rehabilitations because these materials are less affected by corrosive environmental conditions and known to provide longer life with less maintenance. However, there are still some concerns about FRP strengthened reinforced concrete (RC) structures, such as the presence of near-surface defects. Currently limited data exists regarding this issue. the presence of near-surface defects in the form of delaminations between the fiber reinforced polymer (FRP) laminate and concrete substrate can significantly affect the structural integrity and stiffness of the structural section. These defects should be …


Quantification Of Steroid Sex Hormones Using Solid-Phase Extraction Followed By Liquid Chromatography-Mass Spectrometry, Youssef Filali-Meknassi, Muriel Auriol, Craig D. Adams, Rao Y. Surampalli Jan 2007

Quantification Of Steroid Sex Hormones Using Solid-Phase Extraction Followed By Liquid Chromatography-Mass Spectrometry, Youssef Filali-Meknassi, Muriel Auriol, Craig D. Adams, Rao Y. Surampalli

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In this study, the occurrence of trace amounts of natural and synthetic steroid estrogens in the aquatic environment was studied using liquid chromatography coupled with electrospray mass spectrometry, following solid-phase extraction (SPE). the SPE was performed with C18 and NH2 cartridges. the first objective was to develop a reliable method for analyzing steroid estrogens (resulting from human and animal excretions) in different matrices. the method developed was then applied to quantify the occurrence of natural and synthetic hormones (estrone [E1], 17β-estradiol [βE2], 17α-estradiol [αE2], estriol [E3], and 17α-ethinylestradiol [EE2]) in environmental samples in surface water and wastewater treatment plant (WWTP) …


Soil Suction And Behavior Of Chemically Treated Clays, Thomas M. Petry, Cheng Ping Jiang Jan 2007

Soil Suction And Behavior Of Chemically Treated Clays, Thomas M. Petry, Cheng Ping Jiang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Expansive clay soils have caused significant damage throughout the world. Chemical stabilizing agents have been used to reduce the swell of expansive clay soils, but the effect of chemical treatment on the matric and osmotic suction of soils has not been investigated previously. Two subject soils were chosen to study soil suction and the behavior of chemically treated clay. One soil, with high swell potential, was from Irving, Texas. the other soil, with moderate swell potential, was from Slater, Missouri. Hydrated lime and KIS (a proprietary solution containing potash and ammonium lignosulfonate) were used as chemical stabilizers. Select physical and …


Collapse Assessment Of Degrading Mdof Structures Under Seismic Excitations, Mouchir Chenouda, Ashraf Salah Eldin Ayoub Dec 2006

Collapse Assessment Of Degrading Mdof Structures Under Seismic Excitations, Mouchir Chenouda, Ashraf Salah Eldin Ayoub

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Seismic code provisions are now adopting performance-Based methodologies, where structures are designed to satisfy multiple performance objectives. Most codes rely on approximate methods to predict the desired seismic demand parameters. Most of these methods are based on simple SDOF models, and do not take into account neither MDOF nor degradation effects, which are major factors influencing structural behavior under earthquake excitations. More importantly, most of these models can not predict collapse explicitly under severe seismic loads. This study presents a newly developed model that incorporates degradation effects into seismic analysis of MDOF structures. a new energy-Based approach is used to …