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- Nitrogen (2)
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Articles 1 - 17 of 17
Full-Text Articles in Physical Sciences and Mathematics
Photoelectric Characterization Of Bacteriorhodopsin Reconstituted In Lipid Bilayer Membrane, Joel Kamwa
Photoelectric Characterization Of Bacteriorhodopsin Reconstituted In Lipid Bilayer Membrane, Joel Kamwa
Graduate Theses and Dissertations
The objective of this work was to conduct basic research in biologically inspired energy conversion solutions. A photosynthetic protein (Bacteriorhodopsin) was reconstituted in a bi-layer membrane. Then, when a laser beam was shined on the membrane, the photon energy was used by the protein to pump protons across the membrane. The translocation of protons across the membrane was measured as photocurrent. For this purpose, a system was built to characterize the lipid bilayer membranes and to measure the photocurrent. The lipid bilayer membrane was characterized by its capacitance and resistance. A picoampere photocurrent was observed when Bacteriorhodopsin protein was present …
The Economic Viability Of Cocoa Crop Insurance In Ghana, Justin D. Mckinley
The Economic Viability Of Cocoa Crop Insurance In Ghana, Justin D. Mckinley
Graduate Theses and Dissertations
This study was motivated by the fact that Ghanaian cocoa producers face lower yields than other main cocoa producing counties which in turn increases food insecurity for smallholder producers. In addition, low yields experienced by Ghanaian producers is a driving factor for forest degradation and deforestation as cocoa producers encroach further into previously undisturbed forests in efforts to increase their incomes. There are currently production methods to achieve higher yields readily available in Ghana; however, many producers choose not to adopt these methods because they are seen as too risky, or simply cannot adopt them due to financial/credit constraints. A …
Identification And The Significance Of Selective Proteins In Bile And Plasma Of Normal And Health-Compromised Chickens, Balamurugan Packialakshmi
Identification And The Significance Of Selective Proteins In Bile And Plasma Of Normal And Health-Compromised Chickens, Balamurugan Packialakshmi
Graduate Theses and Dissertations
During the last 50 years, animal breeding programs in commercial poultry have made significant progress in the bodyweight gain of broilers but led to several metabolic and skeletal disorders. Lameness associated with proximal femur known as femoral head separation (FHS) or femoral head necrosis (FHN) is one of the major metabolic disorders in poultry industry. In order to select for healthy chickens, markers that can distinguish between healthy and affected birds are required. Biomarkers from blood represent an ideal and rich source of markers which can be obtained using minimally invasive methods. The biomarkers were explored in an experimental model …
Short-Term Effects Of Poultry Litter Or Woodchip Biochar Amendment In A Temperate Zone Agronomic System, Katy Elizabeth Brantley
Short-Term Effects Of Poultry Litter Or Woodchip Biochar Amendment In A Temperate Zone Agronomic System, Katy Elizabeth Brantley
Graduate Theses and Dissertations
Biochar, a charcoal product produced by the anaerobic thermal decomposition of biomass, can provide agronomic benefits when soil applied. However, research is lacking in temperate region soils investigating specific biochar products and their effects on agronomically important crops. A greenhouse study utilizing poultry litter biochar and a field study utilizing pine woodchip biochar were conducted to observe the effects of biochar application to Northwest Arkansas soils on corn growth and nutrient availability. A third experiment investigated poultry litter and pine woodchip biochar influences on soil water retention. In all three experiments, biochar was applied at three rates (0, 5, and …
Oxidative Stability Of Conjugated Linoleic Acid Rich Soy Oil Obtained By Heterogeneous Ruthenium Catalysis, Saurabh Ravindra Lele
Oxidative Stability Of Conjugated Linoleic Acid Rich Soy Oil Obtained By Heterogeneous Ruthenium Catalysis, Saurabh Ravindra Lele
Graduate Theses and Dissertations
Conjugated linoleic acid (CLA) has multiple health benefits but it is difficult to obtain sufficient CLA in a healthy diet to obtain the clinical effects. A CLA rich-soy oil (CLARSO) with up to 20% CLA has been produced by heterogenous catalysis but no studies of its oxidative stability have been reported. CLARSO and soy oil primary and secondary oxidation products were measured at 50oC in the dark. The CLARSO was less stable than soy oil but adsorption bleaching improved its oxidative stability. However, induction times were dependent on the analytical method used. Fatty acid oxidation kinetics was determined by measuring …
Switchgrass Cultivar, Harvest Frequency, Fertilizer Source, And Irrigation Effects On Near-Surface Soil Properties In West-Central Arkansas, Alayna A. Jacobs
Switchgrass Cultivar, Harvest Frequency, Fertilizer Source, And Irrigation Effects On Near-Surface Soil Properties In West-Central Arkansas, Alayna A. Jacobs
Graduate Theses and Dissertations
Switchgrass (Panicum virgatum L.) has been identified as a model bioenergy feedstock crop and is expected to become an important feedstock for future renewable fuel generation. Agronomic management combinations that maximize monoculture switchgrass yield are generally well understood; however, little is known about corresponding effects of differing switchgrass management combinations on near-surface soil properties. The objective of this research was to determine the residual near-surface soil property effects of three years (2008 to 2011) of consistent management combinations to maximize switchgrass biomass production, including cultivar (‘Alamo’ and ‘Cave-in-Rock’), harvest frequency (1-cut and 2-cut systems per year), fertilizer source (poultry …
Applications Of A New Geodata Crawler For Landscape Ecology: From Mapping Natural Stream Hydrology To Monitoring Endangered Beetles, Douglas Ryan Leasure
Applications Of A New Geodata Crawler For Landscape Ecology: From Mapping Natural Stream Hydrology To Monitoring Endangered Beetles, Douglas Ryan Leasure
Graduate Theses and Dissertations
An investigation of endangered American burying beetle (Nicrophorus americanus) ecology led to development of a Geodata Crawler with applications in eco-hydrology. Geodata Crawler includes a national GIS (geospatial information systems) database with layers that quantify climate, land cover, soils, human development, and other attributes of the biosphere. For user-locations in the continental United States, Geodata Crawler can rapidly tabulate site-specific statistics within automatically delineated sample areas: points, site radii, watersheds, and riparian zones, among others. Geodata Crawler supported a multi-scale analysis of N. americanus habitat at a military installation in western Arkansas to produce a Landsat-based monitoring tool. Royle's N-mixture …
Measuring The Role Of Inhibition In Auditory Discrimination In Mice, Tazima Nur
Measuring The Role Of Inhibition In Auditory Discrimination In Mice, Tazima Nur
Graduate Theses and Dissertations
Understanding how inhibitory neurons affect sensory information processing in the cerebral cortex is an ongoing goal of both neuroscience and statistical physics research. In this master's thesis research project, an experimental system has been designed and built for studying how auditory dynamic range depends on inhibitory neurons, based on observations of mouse behavior. In this thesis, firstly, the topic of inhibition and information processing has been introduced. Then two papers related to inhibition and dynamic range has been reviewed in detail. One of the papers is an experimental work that analyzes the affect of inhibition on dynamic range. The other …
Atom-Based Geometrical Fingerprinting Of Conformal Two-Dimensional Materials, Mehrshad Mehboudi
Atom-Based Geometrical Fingerprinting Of Conformal Two-Dimensional Materials, Mehrshad Mehboudi
Graduate Theses and Dissertations
The shape of two-dimensional materials plays a significant role on their chemical and physical properties. Two-dimensional materials are basic meshes that are formed by mesh points (vertices) given by atomic positions, and connecting lines (edges) between points given by chemical bonds. Therefore the study of local shape and geometry of two-dimensional materials is a fundamental prerequisite to investigate physical and chemical properties. Hereby the use of discrete geometry to discuss the shape of two-dimensional materials is initiated.
The local geometry of a surface embodied in 3D space is determined using four invariant numbers from the metric and curvature tensors which …
The Response Of Cotton (Gossypium Hirsutum L.) To Slow Release Foliar Fertilization And The Effect Of Environment On Absorption, James Matthews Burke
The Response Of Cotton (Gossypium Hirsutum L.) To Slow Release Foliar Fertilization And The Effect Of Environment On Absorption, James Matthews Burke
Graduate Theses and Dissertations
In cotton production, nitrogen (N) is the most limiting nutrient and the demand is substantial. Foliar-N fertilization is regarded as an effective and environmentally sound method of supplying cotton with N during times of deficiency and high demand. In response to the potential benefits of the foliar-N fertilization of cotton, a myriad of foliar-N based fertilizers have been created; each with their own individual chemical technology and constitution. Experiments were performed with the objectives of examining the effects of the slow-release foliar-N fertilizer, Nitamin® (1) on the growth and development of field-grown cotton, (2) on uptake under various environmental conditions, …
Alkaline Hydrolyzable-Nitrogen, Seeding Date, And Clay-Fixed Ammonium As Potential Indicators Of Rice Response To Nitrogen Fertilization In Arkansas, Anthony Michael Fulford
Alkaline Hydrolyzable-Nitrogen, Seeding Date, And Clay-Fixed Ammonium As Potential Indicators Of Rice Response To Nitrogen Fertilization In Arkansas, Anthony Michael Fulford
Graduate Theses and Dissertations
Several potential indicators of rice (Oryza sativa L.) response to nitrogen (N) fertilization include the soil<&rsquos>s alkaline hydrolyzable<&minus>N (AH<&minus>N) concentration, seeding date, and the soil<&rsquos>s clay<&minus>fixed NH4<&ndash>N content. Three studies were conducted to: (1) correlate AH<&minus>N, determined using Illinois Soil Nitrogen Test (ISNT) or Nitrogen Soil Test for Rice (N<&minus>STaR), to plant parameters of interest and develop a fertilizer N rate calibration curve capable of predicting the 95% relative grain yield (RGY) fertilizer N rate for rice grown on clayey soils; (2) evaluate the influence of seeding date and N …&minus>&minus>&ndash>&minus>&rsquos>&minus>&minus>&rsquos>
Effects Of Large Scale Growing Season Prescribed Burns On Movement, Habitat Use, Productivity, And Survival Of Female Wild Turkey On The White Rock Ecosystem Restoration Project Of The Ozark-St. Francis National Forest, Henry Tyler Pittman
Graduate Theses and Dissertations
Restoration of woodland and savanna ecosystems has become a common management strategy in the Central Hardwoods region. Over the past two decades forest managers have implemented woodland and savanna restoration at the landscape level (≥10,000 ha), especially using early growing season prescribed fire. The implementation of the restoration strategy has coincided with declines of Eastern Wild Turkey (Meleagris gallopavo silvestris) in many treated areas causing concern that early growing season prescribed fire was impacting wild turkey. We initiated our study to examine the effect of woodland and savanna restoration on the ecology and habitat of wild turkey in the Ozark …
A Mixed Methods Approach Of Communication Campaign Development And Assessment: Identifying The Needs Of An Audience And Determining The Value In Evaluation, Tara Johnson
Graduate Theses and Dissertations
The two articles presented in this thesis used both quantitative and qualitative research methods to examine two distinct stages of communication campaigns: research and evaluation. In the quantitative study, students (n = 440) at the University of Arkansas were surveyed to determine their perceptions of the Arkansas Water Resources Center (AWRC), water resources, and water issues. A questionnaire was developed from an existing instrument, reviewed by a panel of experts, pilot tested, and revised. The researchers found participants were most aware (M = 3.23, SD = 1.14), concerned (M = 4.07, SD = 0.86), and interested (M = 4.10, SD …
Methane Emissions And Ammonia Volatilization From Drill-Seeded, Delayed-Flood Rice On A Silt-Loam Soil In Arkansas, Christopher Wade Rogers
Methane Emissions And Ammonia Volatilization From Drill-Seeded, Delayed-Flood Rice On A Silt-Loam Soil In Arkansas, Christopher Wade Rogers
Graduate Theses and Dissertations
The Environmental Protection Agency (EPA) currently uses a single methane (CH4) emissions factor of 160 kg CH4-C ha-1 for a primary rice (Oryza sativa L.) crop. The emissions factor is based on studies that do not adequately represent current management practices in Arkansas. Another concern is pre-flood fertilizer nitrogen (N) management, as the common N source, urea, is prone to loss via ammonia (NH3) volatilization. Thus, the objective of this research was to investigate trace gas emissions from rice on a silt-loam soil, including CH4 emissions as influenced by nitrogen (N) fertilization (i.e., optimal N and no N) in 2011, …
Effects Of Petroleum Distillates On Amphibian Development, Kate Walker
Effects Of Petroleum Distillates On Amphibian Development, Kate Walker
Graduate Theses and Dissertations
Petroleum distillates are widely used as an energy source and the extraction and disposal of these chemicals are done with little consideration of their effects on aquatic environments. Amphibians are considered excellent ecological indicators but little research has examined effects of petroleum distillates on aquatic species. I evaluated the lethal and sublethal effects on larval amphibians with exposure to petroleum distillates associated with various venues of pollution including hydraulic fracturing. I selected three petroleum distillates (kerosene, oil, and unleaded gasoline) that are known to have negative effects on aquatic organisms and are similar to the common constituents of mixtures used …
Identifying, Monitoring, Quantifying And Converting Algae To Bio-Fuels In Bio-Reactors, Alice C. Jernigan
Identifying, Monitoring, Quantifying And Converting Algae To Bio-Fuels In Bio-Reactors, Alice C. Jernigan
Graduate Theses and Dissertations
Growing algae as a source for bio-fuels has become an area of interest due to concerns about global warming and the reliability and ecology of the production of fossil fuels. Dried algae harvested from a pilot water quality improvement technology at the Rockaway Wastewater Treatment Facility in New York were examined as a source of carbohydrates and lipids for the production of bio-fuels in bio-reactors. The length of storage time, storage conditions, sugar and lipid extraction processes, and fuel production were studied. The results show that if the algae is stored dry (0.015 g/g algae even after a year in …
Fertilizer Nitrogen Uptake Efficiency In Soft Red Winter Wheat And The Ability Of N-Star To Detect Alkaline Hydrolyzable Nitrogen In Crop Residues, Lana Aubrey Clark
Fertilizer Nitrogen Uptake Efficiency In Soft Red Winter Wheat And The Ability Of N-Star To Detect Alkaline Hydrolyzable Nitrogen In Crop Residues, Lana Aubrey Clark
Graduate Theses and Dissertations
Soil testing methods such as the Illinois Soil Nitrogen Test (ISNT) and Direct Steam Distillation (DSD) have been developed which measure alkaline hydrolyzable-N (AH-N) as a means of estimating potentially mineralizable-N. Crop residues play an important role in N cycling. However, the ability of the ISNT and DSD methods to determine AH-N within crop residues is unknown. Therefore, the first objective of this study was to determine the ability of the ISNT and DSD to quantify potentially mineralizable-N within five different crop residues common to Arkansas. Corn (Zea mays L.), soybean (Glycine max, L.), wheat, rice (Oryza sativa, L.), and …