Engineering Commons^™

Dissolved Organic Carbon And The Potential Role To Stream Acidity In The Great Smoky Mountains National Park, Jason R. Brown

Masters Theses

A substantial societal shift towards environmental awareness has focused research efforts on the impacts of pollution on natural landscapes. Improvements to pollutant regulations and technology have resulted in sizeable reductions of atmospheric deposition of anthropogenic acids, especially nitrates and sulfates, which has altered the role of these ions in the environment. As such, understandings of environmental chemistry dynamics have required regular updating.

Through the National Park Service Vital Signs monitoring program, increases in precipitation pH observed in Great Smoky Mountains National Park (GRSM) has been attributed to the reduction of inorganic acid concentrations. Unfortunately, these improvements have not been uniformly …

Oil Debris And Viscosity Monitoring Using Ultrasonic And Capacitance/Inductance Measurements, Matthew Appleby, Fred Choy, Li Du, Jiang Zhe

Dr. Jiang Zhe

No abstract provided.

Oil Debris And Viscosity Monitoring Using Ultrasonic And Capacitance/Inductance Measurements, Matthew Appleby, Fred Choy, Li Du, Jiang Zhe

Fred K. Choy

No abstract provided.

Sea Level Rise Effects On Acidic Pollution In A Coastal Acid Sulphate Soil Area, Ngo Dang Phong, Chu Thai Hoanh, To Phuc Tuong, Reiner Wassmann

International Congress on Environmental Modelling and Software

Bac Lieu is a coastal province in the Mekong River Delta (MRD), Vietnam. Aside from salinity intrusion from the sea, the province is strongly affected by acidic pollution as 58% of the area (250,000 ha) is overlaid with acid sulphate soil (ASS). Previous studies showed that the eminent sea level rise (SLR) would influence the hydrology and salinity of the canal networks in the province. This study, using the previously validated hydraulic and water quality model CRSAP-ACIDITY (Vietnam River Systems And Plains, coupled with ACIDITY Module), aimed at quantifying impacts of different SLR scenarios (SLR=17, 30, 50, or 75 cm) …

Effect Of Temperature On The Corrosion Behavior Of Mild Steel Upon Exposure To Palm Biodiesel

A.S. Md Abdul Haseeb

Recently biodiesel, as an alternative fuel is getting more significance to replace diesel fuel completely or partially. However, corrosion of automotive materials in biodiesel is a major concern as this can reduce engine life. This study aims to investigate the corrosion behavior of mild steel at three different temperatures such as room temperature, 50 and 80 °C. Static immersion tests in B0 (diesel), B50 (50% biodiesel in diesel), B100 (biodiesel) were carried out for 1200 h. At the end of the tests, corrosion characteristic was investigated by weight loss measurements and changes of the exposed metal surface. Fuels were analyzed …

Molecular-Level Modeling Of Proton Transport In Aqueous Systems And Polymer Electrolyte Membranes: A Reactive Molecular Dynamics Study, Myvizhi Esai Selvan

Doctoral Dissertations

Proton exchange membrane (PEM) fuel cells are an eco-friendly power source that has great potential to reduce our oil dependence for our stationary and transportation applications. In order to make PEM fuel cells an economically viable option, further effort is needed to improve proton conduction under wide operating conditions and reduce the cost of production. Design and synthesis of novel membranes that have superior characteristics require a fundamental molecular-level understanding of the relationship between the polymer chemistry, water content and proton conduction. The performance of a fuel cell is influenced by the electrochemical and molecular/proton transport processes that occur at …

The Influence Of Acidity On Microbial Fuel Cells Containing Shewanella Oneidensis, Justin C. Biffinger, Jeremy Pietron, Orianna Bretschger, Lloyd J. Nadeau, Glenn R. Johnson, Cynthia C. Williams, Kenneth H. Nealson, Bradley R. Ringeisen

U.S. Navy Research

Microbial fuel cells (MFCs) traditionally operate at pH values between 6 and 8. However, the effect of pH on the growth and electron transfer abilities of Shewanella oneidensis MR-1 (wild-type) and DSP10 (spontaneous mutant), bacteria commonly used in MFCs, to electrodes has not been examined. Miniature MFCs using bare graphite felt electrodes and nanoporous polycarbonate membranes with MR-1 or DSP10 cultures generated >8W/m³ and ∼400μA between pH 6–7. The DSP10 strain significantly outperformed MR-1 at neutral pH but underperformed at pH 5. Higher concentrations of DSP10 were sustained at pH 7 relative to that of MR-1, whereas at pH …

The Influence Of Ammonia And Carbon Dioxide On The Sorption Of A Basic Organic Pollutant To A Mineral Surface, Maneerat Ongwandee, Glenn Morrison, S. S. Bettinger

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Indoor surfaces have a sorptive capacity for organic pollutants which may be significantly influenced by other gases and the pH of the surface. in this research, we examine the influence of a common indoor gaseous acid, CO₂, and base, NH₃, on the adsorption of a volatile organic base, trimethylamine (TMA), to a mineral surface, zirconium silicate beads. Varying ammonia and CO₂ within concentration ranges of indoor relevance substantially influences the sorptive capacity of this mineral surface. Increasing the CO₂ mixing ratio to 1000 p.p.m. enhances surface capacity of TMA by 40-50%; increasing the NH3 …

The Effects Of Acid Concentration On The Current Efficiency During The Electrolysis Of Zinc Sulfate Solution, Jon Langfeldt

Bachelors Theses and Reports, 1928 - 1970

The current efficiency during the electrolysis of zinc sulfate solution and the various factors that effect the current efficiency are major considerations of this industrial process. The factors affecting current efficiency-- temperature, current density, presence of impurities, time of electrolysis, hydrogen overvoltage, smoothness of the deposit, and acid concentration of the cell solution-- are controlled to the extent that current efficiencies of 90-93% are not uncommon in the industrial electrolytic zinc process. However, additional investigations of the effects of these various factors upon current efficiency are warranted, because of the endless search by the non-ferrous metal industries for additional information …