Open Access. Powered by Scholars. Published by Universities.®
- Institution
- Keyword
-
- Adhesion. (1)
- Asphalt. (1)
- Concrete beams--Testing--Data processing. (1)
- Concrete columns--Testing. (1)
- Concrete--Additives. (1)
-
- Concrete--Cracking (1)
- Concrete--Fracture (1)
- Estuarine pollution -- Oregon -- South Slough Estuary (1)
- Fracture mechanics--Environmental aspects. (1)
- Fracture mechanics--Measurement. (1)
- Fracture mechanics. (1)
- Groundwater -- Pollution -- Mathematical models (1)
- Groundwater flow -- Mathematical models (1)
- Hazardous waste site remediation. (1)
- High strength concrete --Testing. (1)
- Lightweight concrete--Testing. (1)
- Micromechanics. (1)
- Organic compounds. (1)
- Pavements (1)
- Plates (Engineering)--Testing. (1)
- Pneumatics--Environmental aspects. (1)
- Reinforced Concrete--Cracking (1)
- Reinforced concrete--Testing. (1)
- Sanitary landfills -- Environmental aspects -- Mathematical models (1)
- Shear (Mechanics) (1)
- Silica fume. (1)
- Solvents--Aqueous. (1)
- South Slough Estuary (Or.) (1)
- Spline theory. (1)
- Strains and stresses. (1)
Articles 1 - 13 of 13
Full-Text Articles in Engineering
A Study On The Causes Of Variations In Transmissivity And Storativity During Pump Tests At Asylum Lake, Paul Joseph Pare
A Study On The Causes Of Variations In Transmissivity And Storativity During Pump Tests At Asylum Lake, Paul Joseph Pare
Masters Theses
Over a two year period, Western Michigan University ran a number of pump tests in the Asylum Lake Area in Kalamazoo, Michigan. The transmissivities and storativities calculated from these tests differed significantly from well to well in any particular test, and from pump test to pump test. Utilizing the computer programs AQTESOLV 3.0 and Aquifer Parameter Estimator, a number of T and S values were calculated. After analysis of the results, the following conclusion was drawn. The main reason for the deviations in the T and S values arose from the mixing of the results of numerous methods (some of …
A Theoretical Analysis Of Volatile Contaminant Removal By The Pneumatic Fracturing Process, Yuan Ding
A Theoretical Analysis Of Volatile Contaminant Removal By The Pneumatic Fracturing Process, Yuan Ding
Dissertations
A mathematical model that simulates the process of contaminant removal from a pneumatically induced fracture within a porous medium is presented. It includes: (1) model development; (2) parameter evaluation; (3) statistical sensitivity analysis; and (4) model validation.
Based on the dual porosity approach, a mathematical model for a fractured porous formation is developed for both two dimensional and axial symmetrical cases. This model constitutes a pair of coupled partial differential equations for the porous medium and discrete fracture, respectively. The initial and boundary conditions have been determined based on field considerations of a soil vapor extraction system. By means of …
Shear Strength And Fatigue Crack Propagation In Concrete By Energy Method, Wei Wang
Shear Strength And Fatigue Crack Propagation In Concrete By Energy Method, Wei Wang
Dissertations
The limit analysis methods have been commonly used to predict the ultimate flexure strength of reinforced concrete members over 50 years. However, current design formulas for shear in structural concrete are mostly empirical. In part one of this dissertation, attempts are made to apply the theory of plasticity to predict the shear strengths of reinforced concrete structures.
The modified Coulomb-Mohr failure criterion is used as the constitutive law of concrete, and the plastic flow is assumed to be associated with this failure criterion. A generalized formulation for energy dissipation in accordance with the failure criterion and associated flow rule is …
A Nondestructive Method For The Determination Of Fracture Energy In Concrete Structures, Been-Jyh Yu
A Nondestructive Method For The Determination Of Fracture Energy In Concrete Structures, Been-Jyh Yu
Dissertations
It is generally believed that linear elastic fracture mechanics concepts can not be employed in determining fracture parameters in concrete, and therefore most of the current research effort has focused on applying the principles in yielding fracture mechanics. Despite all these efforts, comparison of results reported by many investigators indicate wide variations in fracture toughness values even for essentially similar materials. The main source of discrepancy in the observed results is the existence of a large process zone at the crack tip. Hence, the amount of energy consumed in advancing the crack will depend on the size of the process …
Composite Beam Analogy Fracture Model (Cbafm) : A Non-Linear Fracture Mechanics Model For Concrete, Mohammed Enamul Haque
Composite Beam Analogy Fracture Model (Cbafm) : A Non-Linear Fracture Mechanics Model For Concrete, Mohammed Enamul Haque
Dissertations
The main objective of this dissertation is to develop a simple non-linear fracture mechanics model for the determination of fracture mechanics parameters for concrete, such as fracture process zone length (rp), critical fracture energy release rate (Gic), critical stress intensity factor (KO and fracture energy (GF). The fracture process zone (FPZ) is modeled as a damaged non-elastic cohesive band where the extent of damage due to microcracking varies from no damage at the boundary of FPZ to complete crack surface separation at the notch or macro-crack tip. The proposed method can predict theoretically both the pre-peak and post-peak load versus …
Fundamentals Of Adhesion Of Organic Compounds And Aqueous Cleaning Of Glass And Metal Surfaces : Applications In The Pharmaceutical And Chemical Industries, Michel J. De Ruijter
Fundamentals Of Adhesion Of Organic Compounds And Aqueous Cleaning Of Glass And Metal Surfaces : Applications In The Pharmaceutical And Chemical Industries, Michel J. De Ruijter
Theses
In this thesis we studied the physics and chemistry of the adhesion of various classes of organic compounds to glass and stainless steel surfaces, by using diagnostic aqueous cleaning solutions and other techniques. We defined the thermodynamic requirements for aqueous cleaning based on extensive experimental and theoretical work. Novel cleaning diagrams are introduced, based on electrostatic interactions between organic compounds and solid surfaces, to facilitate the design of aqueous cleaning systems. We studied the mass transfer parameters for selected situations. The electrochemical Pourbaix-diagrams were used to explain the effect of hydrogen peroxide added to aqueous solutions and to avoid corrosion …
Water Quality Model For South Slough, Coos Bay, Oregon, Holly Kay Juza
Water Quality Model For South Slough, Coos Bay, Oregon, Holly Kay Juza
Dissertations and Theses
The South Slough Estuary is located off Coos Bay along the southern coast of Oregon. It is divided into two channels that meet and continue to Coos Bay at the Charleston Harbor. There are six major contributing streams to South Slough. After rainfall events, the level of coliform bacteria in the slough increases because of stream bacteria loading. This is due to cattle grazing in the drainage areas, failed septic systems from private homes, and sewage sludge applied to the County landfill, which drains into the slough. The Oregon Health Division has enforced a Sanitation Management Plan for Commercial Shellfish …
Improved Finite Analytic Methods For Solving Advection-Dominated Transport Equation In Highly Variable Velocity Field, Wei Cuifeng
Improved Finite Analytic Methods For Solving Advection-Dominated Transport Equation In Highly Variable Velocity Field, Wei Cuifeng
Dissertations and Theses
Solute transport studies frequently rely on numerical solutions of the classical advection-diffusion equation. Unfortunately, solutions obtained with traditional finite difference and finite element techniques typically exhibit excessive numerical diffusion or spurious oscillation when advection dominates, especially when velocity field is highly variable. One recently developed technique, the finite analytic method, offers an attractive alternative. Finite analytic methods utilize local analytic solutions in discrete elements to obtain the algebraic representations of the governing partial differential equations, thus eliminating the truncation error in the finite difference and the use of approximating functions in the finite element method. The finite analytic solutions have …
Micromechanics Of Hot Mix Asphalt Material Formulation And Numerical Simulation, Kuo-Neng G. Chang
Micromechanics Of Hot Mix Asphalt Material Formulation And Numerical Simulation, Kuo-Neng G. Chang
Dissertations
Hot Mix Asphalt (HMA), a highway and airfield pavement material, is heterogeneous, granular, and composite. It is traditionally modeled as a homogeneous material using continuum mechanics or semi-empirical methods. As a result, the above models either neglect or over-simply component reactions, failing to predict field performance problems resulting from particle segregation. This research presents micromechanical modeling, a novel approach that accounts for the components.
A micromechanical model is developed for HMA by modeling it as an assembly of asphalt cement coated particles. The asphalt cement is modeled as a viscoelastic material. To represent asphalt cement, several viscoelastic elements (i.e. Maxwell, …
Analysis Of Plates And Reinforced Concrete Columns By Cubic B-Spline Function, Gang Wang
Analysis Of Plates And Reinforced Concrete Columns By Cubic B-Spline Function, Gang Wang
Dissertations
Applying spline functions to numerical structural analysis has been more common in recent years. The recent increase use of spline functions is mainly due to their excellent characteristics, such as sectionalized continuity, linear combination, flexibility, and easy use for various boundary conditions. The whole deformed shape of some structures or substructures can be described with one displacement function constructed by a series of spline functions. By doing this, the mesh generation and the huge computer memory space are no longer needed because only one single superelement can be used in the whole process. The choice of spline functions as displacement …
Mechanical Behavior Of Polystyrene Foam Bead Lightweight Concrete, Hai-Ying Ni
Mechanical Behavior Of Polystyrene Foam Bead Lightweight Concrete, Hai-Ying Ni
Theses
This thesis is designed to investigate the effect of porosity on the mechanical properties (strength and modulus) of concrete, and to evaluate the effect of silica fume on the mechanical properties of the polystyrene foam bead lightweight concrete. In this research we made the lightweight concrete by using polystyrene foam beads as light weight aggregate and studied its mechanical properties in detail. Due to the near zero density and modulus of foam beads, we were able to consider it as "porosity". We could then control porosity in concrete by varying foam bead volume fraction.
In our experiments we used the …
Stress-Strain Behavior Of High Strength Concrete Cylinders, Danqing Chen
Stress-Strain Behavior Of High Strength Concrete Cylinders, Danqing Chen
Theses
Due to the recent development of high strength concrete in engineering and construction, it has become more important to study the behavior of materials in structures.
No results have been previously published in the literature regarding the influence of aspect ratio in plain high strength concrete cylinders on stress-strain behavior under uniaxial compression.Thus at present study, compression tests were conducted on 3x6 in., 3x9 in., and 3x12 in. plain high strength concrete cylinders to study their stress-strain behavior. Plain normal strength concrete cylinders were also tested and used for comparative study.
Based on the present investigations, attempting to obtain a …
Resuspension Behavior Of Natural Estuarine Sediments, Chang-Hee Lee
Resuspension Behavior Of Natural Estuarine Sediments, Chang-Hee Lee
Dissertations, Theses, and Masters Projects
The resuspension behavior of natural estuarine sediments was studied using the VIMS Sea Carousel, a benthic annular flume. The bed shear stresses produced by the flume were measured by a hot-film sensor mounted flush on the bottom of a laboratory version of the Carousel under a clear-water and flat-bottom condition. Measurements showed a reasonably uniform bed shear stress across the channel and agreed with the relationship &\tau\sb{lcub}\rm b{rcub}=0.011\Omega\sp{lcub}1.69{rcub},& where &\Omega& = ring speed (rpm) and &\tau\sb{lcub}\rm b{rcub}& = spatially-averaged bed shear stress (N/m&\sp2&), predicted from a previous numerical study. Thus, the &\tau\sb{lcub}\rm b{rcub}& was used as a bed shear stress …