UNT Libraries - 8 Matching Results

Search Results

Results: 1 - 8
open access

Use of Automated Sampler to Characterize Urban Stormwater Runoff in Pecan Creek

Description: The purpose of this study was to use the Global Water Stormwater Sampler SS201 to characterize the urban runoff in Pecan Creek. Location of the samplers was influenced by land use and ease of installation. Determination of the constituents for analysis was modeled after those used in the NPDES permit for seven cities within the Dallas/Ft.Worth metroplex. Some metals, notably cadmium and arsenic, exceeded the U.S. EPA's MCL's. Statistical analysis revealed first flush samples to be significantly… more
Date: December 2000
Creator: Appel, Patrick L.
Item Type: Refine your search to only Thesis or Dissertation
open access

Desorption/Diffusion of Benzene After Simulated Ground Water Remediation

Description: A study was undertaken to examine the desorption/ iffusion of benzene after simulated ground water remediation in aquifer material of differing carbon content using column experiments and comparing the results to batch experiments and adsorption empirical relationships. It was hypothesized that the organic carbon of the aquifer material will affect desorption/diffusion. Results from the column experiment indicated no significant difference in the increase benzene concentrations after remediatio… more
Date: December 1989
Creator: Bennett, Kathryn C. (Kathryn Condreay)
Item Type: Refine your search to only Thesis or Dissertation
open access

Effects of Sertraline Exposure on Fathead Minnow (Pimephales promelas) Steroidogenesis

Description: Sertraline is a selective serotonin reuptake inhibitor (SSRI) that is widely used for the treatment of depression and anxiety. Due to the abundant therapeutic use of sertraline, low levels have been detected in municipal wastewater effluents suggesting that aquatic organisms may be exposed. The purpose of this study was to evaluate the steroidogenic effects of sertraline on larval (FHM) and adult female fathead minnows (FFHM), Pimephales promelas. Larval FHM were exposed to 0.1, 1, and 10 µg/L … more
Date: December 2014
Creator: Carty, Dennis R.
Item Type: Refine your search to only Thesis or Dissertation
open access

Environmental Factors Influencing Chlorophyll-a Concentrations in Lake Texoma

Description: An analysis of algal biomass measured by chlorophyll-a concentration in Lake Texoma was performed as a part of a monitoring program to develop baseline environmental data in order to detect the potential effects of engineered changes in chloride concentrations in the reservoir. This portion of the research project focused on two main research objectives. The first objective was evaluating the effect of sampling strategy on the ability to adequately reflect standing crop estimates and trends in … more
Date: December 1998
Creator: Gibbs, Jennifer S. (Jennifer Sokolovic)
Item Type: Refine your search to only Thesis or Dissertation
open access

Effects of Suspended Solids on Bioavailability of Chemicals to Daphnia magna and Pimephales promelas

Description: Three suspended solids types containing a range of physicochemical characteristics were used to determine the effect of suspended solids on the bioavailability of acenaphthene, 1,2,4,5-tetrachlorobenzene, zinc, and chlordane to Daphnia magna and Pimephales promelas. Generally, the bioavailability of zinc and chlordane decreased due to interactions with all suspended solids types while bioavailability of acenaphthene and 1,2,4,5-tetrachlorobenzene were not clearly reduced. Partition coefficients… more
Date: December 1984
Creator: Hall, W. Scott (Warren Scott)
Item Type: Refine your search to only Thesis or Dissertation
open access

The Effects of Pulp and Paper Mill Wastewaters on Phytoplankton Primary Productivity in the Red River, Louisiana

Description: Responses of phytoplankton productivity in the Red River to unbleached pulp and paper mill wastewaters were monitored using in situ ^14C incubation. Preoperational studies, conducted prior to the discharge of mill wastewaters varied seasonally, but revealed similar productivity trends when compared with postoperational studies, conducted after mill discharges began entering the Red River. Carbon assimilation rates measured downstream of mill discharge were generally greater than upstream levels… more
Date: May 1984
Creator: Holler, Jeffrey Dee
Item Type: Refine your search to only Thesis or Dissertation
open access

Atmospheric Visibility Assessment for Urban Areas Using Photographic Slides and Optical Densitometry

Description: The factors involved in calculating Standard Visual Range (SVR) are discussed, and a comparison is made between the visibility reported by airport observers and the photographic slide/ optical densitometer method of calculating SVR. Using slides of Houston, Texas, from the fall and winter of 1988-89, it was found that the altitude at which the contrast measurements are made significantly affects the SVR. Also an index for predicting high and low humidity was developed using the blue/red ratio o… more
Date: May 1992
Creator: Jacob, Mary Katherine
Item Type: Refine your search to only Thesis or Dissertation
open access

Multiple Regression Equations to Estimate Mean Nutrient Concentrations in Streams of North Central Texas from Landsat Derived Land Use

Description: Nutrients are of critical concern in water quality assessment. The development of empirical models to estimate mean nutrient concentrations, based on satellite derived land use, could aid water resource managers. Models using land use acreages outperformed those using percentages, and discrete urban land uses were superior to lumped urban. Regressions of the combinations of two, three and four of the eight possible land use variables were investigated. Sensitivity analyses, with one stream dele… more
Date: May 1994
Creator: Kerr, Barry Douglas
Item Type: Refine your search to only Thesis or Dissertation
Back to Top of Screen