Digital Commons Network^™

Assessing Linkages Among Landscape Characteristics, Stream Habitat, And Macroinvertebrate Communities In The Idaho Batholith Ecoregion, Andrew C. Hill

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Understanding the composition of lotic communities and the landscape processes and habitat characteristics that shape them is one of the main challenges confronting stream ecologists. In order to better understand the linkages among landscape processes, stream habitat, and biological communities and to understand how accurately our measurements represent important factors influencing biological communities, it is important to test explicit hypotheses regarding these linkages. Increasing our understanding of aquatic communities in a hierarchical context and recognizing how well our measurements represent factors structuring aquatic communities will help managers better evaluate the influence of land management practices on aquatic ecosystems, direct conservation …

Optimizing The Physical And Nutritional Environment Of Unleached Root-Zones, Curtis B. Adams

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Unleached root-zones represent an environmental ideal by eliminating wasteful leaching of nutrients and water. NASA grows plants in space in unleached root-zones, incorporating polymer-coated fertilizer (PCF) into a ceramic media (Turface or Profile). However, lack of growth productivity in space has led to the need for research to improve the nutritional and physical environment of the root-zone, which is the objective of this research. PCF types are diverse in release characteristics and the effects of temperature and substrate water content have not been well characterized. In spite of widespread use, studies on chemical properties and applied studies to verify soil …

Mathematical Modeling Of Light Utilization And The Effects Of Temperature Cycles On Productivity In A Steady-State Algal Photobioreactor, Peter Edwin Zemke

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The work presented here investigated two methods of improving productivity in microalgal photobioreactors: applying temperature cycles intended to maximize photosynthesis and minimize respiration, and development of a mathematical model that predicts improvements in photon utilization using temporal light dilution (flashing).

The experiments conducted on diurnal temperature cycles with Dunaliella tertiolecta in 30-L outdoor photobioreactors showed that a properly chosen temperature cycle can improve mass and energy productivity by 18% over an identical photobioreactor with a constant temperature. However, excessively large temperature cycle amplitudes reduced productivity. A 4-7% increase in energy content was observed in microalgae exposed to temperature cycles. The …

Effects Of Temperature And Humidity On Glass-Reinforced Nylon Rotating Bands, Marc D. Raby

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Certain 30mm munitions used in various military applications are configured with a glass-reinforced nylon band that acts as a firing ring or rotating band. The purpose of this research is to investigate whether storage environments compromise the strength and integrity of the glass-reinforced nylon rotating bands by researching the environmental factors that will degrade nylon and by performing tests to investigate if these factors will embrittle nylon composites. Moisture and temperature are found to be the environmental factors that will have an effect on the rotating bands in their respective storage environments. Absorbed moisture is found to increase the impact …