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Actinoplanes Philippinensis: Effect of Carbon Sources on Zoospore Production (open access)

Actinoplanes Philippinensis: Effect of Carbon Sources on Zoospore Production

Actinomycetes are able to utilize a great variety of carbohydrates, like sugar. The particular kind of sugar and its concentration has decisive effect on the growth of microorganisms. The proper nutritional media aids also in the production of spores. Based on this generalization, that the growth and sporulation of microorganisms are greatly influenced by the nature and the concentration of carbohydrates, an attempt has been made to study Actinoplanes philippinensis with respect to this influence.
Date: May 1968
Creator: White, Olivia
System: The UNT Digital Library
The Adaptability and Present Status of Andropogon Ischaemum L. in Denton County, Texas (open access)

The Adaptability and Present Status of Andropogon Ischaemum L. in Denton County, Texas

This investigation has been made with reference to the adaptability of Andropogon ischaemum, King Ranch bluestem, to various soils, various slopes, and various erosion conditions in Denton County.
Date: 1951
Creator: Belders, Floyd William
System: The UNT Digital Library
Analysis of Phytoplankton Responses to Water Chemistry Dynamics in a Moderately Eutrophic North Texas Reservoir (open access)

Analysis of Phytoplankton Responses to Water Chemistry Dynamics in a Moderately Eutrophic North Texas Reservoir

Canonical correspondence analysis (CCA) was used to explore relationships between measured environmental variables and in situ phytoplankton communities in a moderately eutrophic North Texas Reservoir.
Date: May 1998
Creator: Banks, Kenneth E. (Kenneth Edward)
System: The UNT Digital Library
Assimilation of Inorganic Nitrogen by Aquatic Actinomycetes (open access)

Assimilation of Inorganic Nitrogen by Aquatic Actinomycetes

It was the purpose of this investigation to present laboratory data concerning the assimilation of inorganic nitrogen by the aquatic actinomycetes. The strains of aquatic actinomycetes under consideration represented a cross section of those currently under culture at North Texas State University.
Date: August 1962
Creator: Davis, Ernst M.
System: The UNT Digital Library
The Autecology of Celtis Laevigata in Flood Plain Forests of Denton County, Texas (open access)

The Autecology of Celtis Laevigata in Flood Plain Forests of Denton County, Texas

This thesis describes the present nature of one facet of some of the flood plain forest stands in Denton County, Texas. The specific purpose was to demonstrate the presence or absence of difference between the Celtis laevigata (commonly known as the hackberry, southern hackberry or sugarberry) populations in stands on Denton Creek and Elm Fork of the Trinity River.
Date: January 1970
Creator: Hander, Lecil B.
System: The UNT Digital Library
Bacterial Survey of Representative Denton County Wells with Special Reference to Sanitation (open access)

Bacterial Survey of Representative Denton County Wells with Special Reference to Sanitation

This thesis aimed to study the seventy-two representative wells of Denton County and to determine the possibilities of infection with typhoid organism. The sanitary survey and the test for Colon-Aerogenes bacteria show that 55% of the 72 wells studied are unsanitary, 27% are sanitary, and 18% are doubtful.
Date: June 1937
Creator: Roberts, Sally Stevens
System: The UNT Digital Library
Bacteriological Studies of the Campus Drinking Fountains of North Texas State Teachers College Denton, Texas (open access)

Bacteriological Studies of the Campus Drinking Fountains of North Texas State Teachers College Denton, Texas

"In order to gain an adequate idea of the sanitary condition of the drinking fountains on the North Texas State Teachers College campus, it was found necessary to approach these bacteriological studies from a seasonal point of view."--1.
Date: August 1941
Creator: McCoy, Eloise
System: The UNT Digital Library
A Bio-Chemical Comparative Study of the Plankton in Lake Dallas and Pecan Creek (open access)

A Bio-Chemical Comparative Study of the Plankton in Lake Dallas and Pecan Creek

The purpose of this investigation is to compare the dissolved and suspended organic material in Lake Dallas to that coming into the lake through Pecan Creek.
Date: 1940
Creator: Brooks, Benjy Frances
System: The UNT Digital Library
The Biological Elimination of Phenols in the Effluent of a Wood Preserving Plant (open access)

The Biological Elimination of Phenols in the Effluent of a Wood Preserving Plant

The removal of phenols from the waste waters of wood preserving plants has always presented problems. The purpose of this paper is to investigate the possibility of employing a biological system to reduce the phenol content of effluent from these plants.
Date: August 1971
Creator: Rainey, John G.
System: The UNT Digital Library
Carbon Flux in Reservoir Sediments (open access)

Carbon Flux in Reservoir Sediments

The central objective of the study was to fractionate sedimenting organic materials according to their source (allochthonous or autochthonous) and ultimately to determine the degree of biodegradability of contributions from either source with particular reference to activities at the mud-water interface.
Date: May 1973
Creator: Newton, Charles Eugene
System: The UNT Digital Library
Comparative Chemistry of Thermally Stressed North Lake and Its Water Source, Elm Fork Trinity River (open access)

Comparative Chemistry of Thermally Stressed North Lake and Its Water Source, Elm Fork Trinity River

To better understand abiotic dynamics in Southern reservoirs receiving heated effluents, water was analyzed before and after impoundment in 330 ha North Lake. Macronutrients, metals, and chlorinated hydrocarbons were measured. Concentrations of nutrients and metals in sediments were quantified in this 2 yr study. River water prior to impoundment contained 16 times more total phosphorus, and supported 23 times more Selenastrum capricornutum cells in an algal assay than reservoir water. The reservoir has essentially no drainage and since evaporation is high, the concentrations of many dissolved solids have increased since the reservoir was filled in 1958. North Lake is now phosphorus limited. Apparently altered chemical equilibria have caused precipitation or adsorption of phosphorus with calcium and iron.
Date: December 1976
Creator: Sams, Barry L.
System: The UNT Digital Library
A Comparison of Predicted and Actual Trophic Status of Lake Ray Roberts, Texas Based on Chlorophyll A (open access)

A Comparison of Predicted and Actual Trophic Status of Lake Ray Roberts, Texas Based on Chlorophyll A

Two years before impoundment, the trophic status of Lake Ray Roberts was predicted by applying the total phosphorus input into the Organization for Economic Cooperation and Development (OECD) eutrophication model. Predicted mean summer epilimnetic (MSE) chlorophyll a of Elm Fork arm, Isle duBois arm and Main Body were in the eutrophic category of the OECD model. Observed MSE chlorophyll a two years after impoundment of Elm Fork arm, Isle duBois and Main Body had not reached their predicted means and were at the mesotrophic-eutrophic boundary of the OECD model. Six years after impoundment, observed MSE chlorophyll a for Main Body, was closer to its predicted mean and in the eutrophic category of the OECD model. Six years after impoundment, Elm Fork arm was the most productive area of Lake Ray Roberts. Observed means of chlorophyll a, total phosphates, suspended solids and turbidity were often highest in the Elm Fork arm. Wastewater effluent from Gainesville and Valley View, TX, had an impact on productivity in Elm Fork arm.
Date: May 1999
Creator: Lytle, Lili Lisa
System: The UNT Digital Library
A Comparison of the Carbon Dioxide and Oxygen Rate of Change Methods for Measuring Primary Productivity (open access)

A Comparison of the Carbon Dioxide and Oxygen Rate of Change Methods for Measuring Primary Productivity

The purpose of this study was to demonstrate the variability of oxygen and carbon dioxide rate of change methods for measuring primary productivity and respiration in an aquatic environment.
Date: May 1969
Creator: Trotter, Dennis M.
System: The UNT Digital Library
Composition and Distribution of the Vegetation in Farm Pastures in Denton County, Texas (open access)

Composition and Distribution of the Vegetation in Farm Pastures in Denton County, Texas

This investigation has for its aim the determination and the evaluation of the vegetational composition in certain farm pastures in Denton County, Texas.
Date: 1946
Creator: Parker, Robert S.
System: The UNT Digital Library
Correlation of Humus and Water Content on Saba Clay, Denton, Texas (open access)

Correlation of Humus and Water Content on Saba Clay, Denton, Texas

This study is an attempt to determine the relationship between humus and the water found in it and how both effect soil in Denton county, Texas.
Date: August 1938
Creator: Wilson, Clyde Byron
System: The UNT Digital Library
A Correlation of Humus with Water Content and Crop Rotation in San Saba and Denton Clays, Denton County, Texas (open access)

A Correlation of Humus with Water Content and Crop Rotation in San Saba and Denton Clays, Denton County, Texas

A study of the humus content and the water content of San Saba clay and Denton clay. Studies show that the physical properties of soil are conducive to moisture retention and the availability of moisture to plants.
Date: August 1939
Creator: Culwell, John Walton
System: The UNT Digital Library
Degradation of Phenolic Acids by Azotobacter Species Isolated from Sorghum Fields (open access)

Degradation of Phenolic Acids by Azotobacter Species Isolated from Sorghum Fields

Sorghum plants excrete phenolic acids which reduce subsequent crop yields. These acids accumulate in field soil by combining with soil and clay particles to form stable complexes which remain until degraded by bacterial metabolism. The amount of phenolic acids in soil samples were obtained by gas chromatography measurements, while Azotobacter populations were obtained by plate counts in 40 sorghum field samples from Denton County, Texas. One can conclude that increasing the Azotobacter population in the soil increased the degradation rate of phenolic acids proportionally. It is proposed that seed inoculation will introduce selected strains of Azotobacter into the soil. The presence of Azotobacter should increase crop size in subsequent plantings.
Date: August 1989
Creator: Al-Hadhrami, Mohamed N. (Mohamed Nasser)
System: The UNT Digital Library
Distribution of Phosphates in a Sewage Plant and its Receiving Waters (open access)

Distribution of Phosphates in a Sewage Plant and its Receiving Waters

The purpose of this paper is to detail the distribution and quantity of soluble phosphates in an activated sludge plant, its discharge creek, and receiving reservoir. The resultant analyses and comparison of data should provide some better understanding of the fate of phosphorus in a Southwestern waterway system.
Date: May 1969
Creator: Hansard, John D.
System: The UNT Digital Library
The Dynamics of a Planktonic Microcrustacean Community in a Small North Central Texas Pond Ecosystem (open access)

The Dynamics of a Planktonic Microcrustacean Community in a Small North Central Texas Pond Ecosystem

Seven species of planktonic microcrustacea were identified from the North Texas State University Golf Course Pond. Total adult microcrustacean community density, biomass and biocontent, and seasonal cycles of each species were compared with northern populations. Species diversity and evenness indices were highest in summer and lowest in spring. Variations in microcrustacean density showed a positive correlation with density of phytoplankton. Temperature had a direct effect on metabolic rates of two species of copepods. Metabolic rates of pond species were lower at common temperatures than those of northern populations. An estimate of annual energy flow through the pond ecosystem showed cladocerans contributed the greater percentage of total energy to the next trophic level.
Date: December 1976
Creator: Smith, George Arthur
System: The UNT Digital Library
Edaphic Factors Which Control the Distribution of the Common Mesquite, Prosopis Chilensis (Molina) Stuntz in Denton County, Texas (open access)

Edaphic Factors Which Control the Distribution of the Common Mesquite, Prosopis Chilensis (Molina) Stuntz in Denton County, Texas

This paper deals with the distributional outgrowths of Prosopis chilensis (Molina) Stuntz, the common mesquite, in Denton County, Texas.
Date: 1942
Creator: Steph, Harlan J.
System: The UNT Digital Library
The Effects of Organic Surface Amendments on Soil Nutrients and Initial Tree Establishment (open access)

The Effects of Organic Surface Amendments on Soil Nutrients and Initial Tree Establishment

This study examined the effects of replicating woodland soil surface horizonation on the nutrient status of underlying soils and the initial establishment and growth of trees. A total of 283 container grown trees were planted in a bufferzone around a future landfill site. Control amendments consisted of an 8 cm layer (0.5 m3) of wood chips applied in a circular area of 4.6 m2 around the trees' planting pit. For the treatment, a 2.5 cm layer of composted biosolids (0.15 m3 or 80 Mg/ha) was applied in a circular area of 4.6 m2 around the trees' planting pit followed by an 8 cm layer (0.5 m3) of wood chips. The results indicate that the replication of woodland soil surface attributes using composted biosolids can significantly improve the nutrient status of underlying soil. Some significant effects were seen under control conditions, too. However, the effects on tree establishment and growth parameters were, for the most part, not statistically significant.
Date: May 1999
Creator: Thuesen, Kevin (Kevin Andrew)
System: The UNT Digital Library
Eutrophic Levels of Different Areas of a Reservoir: A Comparative Study (open access)

Eutrophic Levels of Different Areas of a Reservoir: A Comparative Study

It was the purpose of this investigation to attempt to demonstrate if differences in eutrophic levels existed among selected areas of Garza-Little Elm, and to demonstrate the role that sediments play in affecting eutrophication.
Date: August 1970
Creator: Hendricks, Albert C.
System: The UNT Digital Library
Evaluation in Soil Moisture in Soil and Water Conservation Practices in Denton, Texas (open access)

Evaluation in Soil Moisture in Soil and Water Conservation Practices in Denton, Texas

This investigation has attempted to show that soil and water conservation practices do increase the amount of soil moisture in five of Denton County, Texas soils: Denton clay, Durant clay, San Saba clay, Kirvin fine sandy loam, and Tabor fine sandy loam.
Date: 1940
Creator: Rylander, Halley G.
System: The UNT Digital Library
Evaluation of a Constructed Wetland to Reduce Toxicity from Diazinon at the Pecan Creek Wastewater Treatment Plant, Denton, TX (open access)

Evaluation of a Constructed Wetland to Reduce Toxicity from Diazinon at the Pecan Creek Wastewater Treatment Plant, Denton, TX

The City of Denton Pecan Creek Wastewater Treatment Facility has periodically failed effluent toxicity testing. A Toxicity Identification Evaluation has determined that Diazinon in the effluent is contributing to the observed toxicity. Chlorpyrifos is also implicated as a factor. The City of Denton constructed a half acre experimental wetland to remove Diazinon related toxicity. Results from spiking and microcosm experiments indicate that the wetland can reduce the Diazinon.
Date: May 1996
Creator: Baerenklau, Amy L. (Amy Lyn)
System: The UNT Digital Library