Engineering Commons^™

Characterization Of Steel Corrosion In An Aggressive Environment, Sung Min Maeng

Theses

As part of the Sustainable Green Manufacturing Program, the corrosion resistance of sputtered tantalum is being studied in order to evaluate it as a replacement coating for electroplated chrome. To accomplish this, studies were conducted to evaluate corrosion properties of the gun barrel steel by employing corrosion rate and bulk measurements including x-ray diffraction (XRD), scanning electron microscopy (SEM)/energy dispersive x-ray spectroscopy (EDX), and x-ray fluorescence (XRF), as well as synchrotron-based x-ray absorption spectroscopy (XAS).

Corrosion behavior of steel immersed in an aggressive environment of 37.8 % hydrochloric acid at room temperature was investigated as a function of time from …

Modeling Of A Permeable Reactive Barrier, Guatam C. Ijoor

Theses

The focus of the presentstudy was centered on the modeling analysis to support the Permeable Reactive Barrier (PRB) design. The flow model formulated to simulate the Permeable Reactive Barrier System integrated the available geologic, hydro geologic and geo-chemical data from numerous recent installations to simulate a subsurface ground water scenario.

Different generic cases that a PRB system would fall into were identified based on its utility and aquifer conditions and then employed to produce different model adaptations. The different simulation codes and interfaces were evaluated, and the most expedient of them was used to simulate the Model.

The simulations were …

Coagulation And Disinfection By-Products Formation Potential Of Dissolved Organic Matter Fractions, Neeraj S. Pipada

Theses

Both the proposed United States Environmental Protection Agency (USEPA) Disinfectants- Disinfection By-Products and Enhanced Surface Water Treatment rules have provisions for minimizing the formation of undesirable precursors of disinfection by-products (DBPs) in drinking water Natural Organic Matter (NOM) contains many of the precursors to the DBPs formed following disinfection of drinking water. DAX-8 resin procedures were used to isolate and fractionate NOM into six dissolved organic matter (DOM) fractions; Hydrophobic acid (FA), base (FB), neutral (FN), and hydrophilic acid (PA), base (PB) and neutral (PN). Aluminum sulfate (alum) jar coagulation tests were performed to determine the optimum coagulation ranges of …

Analysis And Modeling Of Ultrasound To Decontaminate Heavy Metals In Dredged Sediments, Ruvini Perera

Theses

Sediments contaminated with heavy metals due to past disposal practices threatens the environment and requires remediation. This research is an attempt to develop a technology to decontaminate heavy metals in the dredged sediments with an integrated set of processes using ultrasound. Acoustic cavitation caused by ultrasound energy can be used to remove chromium from the sediments. Two coupled processes were used to treat both coarse (Process#1) and fine (Process#2) fractions of the sediments. Full factorial experimental designs were carried out to evaluate the treatment technique and to statistically model and optimize the processes. The model for Process#1 had four contributing …

Ultrasound To Decontaminate Organics In Dredged Sediments, Kanya Veerawat

Theses

In this research, it was attempted to decontaminate and separate dredged sediments contaminated with organic compounds by the application of ultrasound energy coupled with sub-atmospheric pressures. The decontamination and separation of contaminated sediments was achieved by integrated two processes. For Process 1, ultrasound energy was used to decontaminate the sandy fraction in dredged sediments, and sub-atmospheric pressure was used to separate and remove fines. For Process 2, ultrasound was again used to decontaminate fines with bulk fluid, and sub-atmospheric pressure was used to remove the contaminants with water. Process 1 was evaluated and found to have four variables contributing to …

Production Of Submicron Aerosols By Powder Depressurization, Amit Haryani

Theses

Disaggregation of dry powders in shear flow has limitations in producing submicron particles. This study explores a new method for the production of submicron particles by the depressurization of powder aerosols. The depressurization mechanism is based on the rapid depressurization of the aggregated powder through a specially designed nozzle. As the pressure suddenly decreases from very high values inside the aggregates (800 psi) to ambient at the surface of such aggregates, disaggregation takes place due to the force exerted by the gas escaping through their pore structure.

he effect of various process parameters, namely: nozzle diameter, pressure and pretreatment with …