1,606 research outputs found
A study of the acetic anhydride method for the determination of citric acid
Citric acid is an important compound of many systems. Numerous methods, both qualitative and quantitative, have been used for the determination of the compound. Some of the biological systems investigated include fermentation studies, action on yeasts, antioxidant in fruits, additive in bakery goods and salad dressing preparations, amounts in vegetables, and others.The above examples are not complete; they only show the varied applications of citric acid. The purpose of this project was to investigate a quantitative spectrophotometric method using anhydrous conditions based on the citric acid-acetic anhydride-pyridine reaction. Conditions affecting the reaction were investigated and optimized for maximum sensitivity and minimum reaction time
Habitat Assessment for Potential Reintroduction of Black Bears to the Mobile-Tensaw Delta of Southwestern Alabama
Black bears (Ursus americanus) have been extirpated from all but a few areas in southwestern Alabama, and the remaining enclaves are rapidly being lost to development. Adjacent to those remnant bear populations are extensive {\u3e125,000 ha) bottomland hardwood forests in the Mobile-Tensaw Delta {MTD), but bears are nearly absent there. Reintroduction may be possible to reestablish black bears in the MTD and improve the viability of the overall bear population in southwestern Alabama. To determine whether a reintroduction effort is likely to succeed in the MTD, I assessed habitat quality, den site availability, and public support of a restoration effort. To evaluate the habitat quality of the MTD for bears, I compared it with similar alluvial habitats at White River National Wildlife Refuge (White River NWR), where the bear population is high. I then performed a flood simulation using GIS to assess the availability of safe ground dens in the MTD. Finally, I used the Bowman et al. (2004) model based on demographic variables (i.e., age, race, sex) to predict human attitudes towards black bear restoration efforts in the MTD and surrounding areas. I collected data from overstory, midstory, and understory vegetation plots in the MTD and on the North and South management units at White River NWR. Using principal components analysis followed by principal variable selection, I determined that 9 variables associated with 5 principal components (hard mast, soft mast, den tree availability, large tree availability, and total basal area) best explained the variation among the 3 study areas. I detected differences among the study areas for 3 of those principal components (hard mast, soft mast, and den tree availability; t ranged from 2.71 to 5.70, P 0.001). Flood simulations for various recurrence levels indicated that nearly all of the MTD floods each year with the only dry locations occurring along the Alabama River. The MTD and surrounding areas showed moderate public support for a black bear reintroduction (range = 25.4-73.8%). Although my study revealed that hard and soft mast production in the MTD was lower than at White River NWR, a previously developed Habitat Suitability Index model and comparisons of hard mast basal area between the MTD (5.39 m2/ha) and Tensas River National Wildlife Refuge (6.98 m2/ha) suggested food resources in the MTD were adequate. A more serious deficiency of the MTD was the almost total lack of suitable den sites, a critical habitat component given the duration and severity of winter flooding there. Flood simulation models indicated that the northern portions of the MTD along the Alabama River were least likely to be inundated and, therefore, were most suitable for ground reintroduction sites. Given that only moderate support for black bear restoration efforts in the MTD was predicted, a strong public relations program will be critical for the reintroduction to be successful. Reintroduction of black bears could be successful in the MTD through the use of artificial denning structures, but long-term population viability will require changes in timber management practices to ensure that adequate tree dens are available
Non-ALJ Adjudicators in Federal Agencies: Status, Selection, Oversight, and Removal
This article republishes—in substantively similar form—our 2018 report to the Administrative Conference of the United States (ACUS) concerning federal agencies’ adjudicators who are not administrative law judges (ALJs). (We refer to these adjudicators as “non-ALJ Adjudicators” or “non-ALJs.”) As our data indicate, non-ALJs significantly outnumber ALJs. Yet non-ALJs are often overlooked and difficult to discuss as a class because of their disparate titles and characteristics. To obtain more information on non-ALJs, we surveyed agencies on non-ALJs’ hearings and, among other things, the characteristics concerning non-ALJs’ salaries, selection, oversight, and removal. We first present our reported data on these matters, which are the most comprehensive data to date on the non-ALJs’ indicia of impartiality. We then provide suggested practices for agencies to promote non-ALJs’ actual and apparent impartiality in presiding over agency hearings
CLUSTERING ENVIRONMENTS BASED ON CROSSOVER INTERACTIONS AND USING GRAPHICAL APPROACHES TO VISUALIZE CLUSTERS
Crossover interactions occur in evaluation trails when ranks of cultivars change across environments. Determining groups of environments within which crossover interactions are minimized may facilitate making cultivar recommendations. Model-based approaches to finding such clusters have been previously described. Our goal was to describe a new, non-model based approach of defining these clusters and then apply this method to a 59 environment x eight maize (Zea mays L.) cultivar data set. Hierarchical clustering of a 59 x 59 distance matrix defined two environmental clusters within which the total crossover interaction was reduced by approximately one-third and four clusters within which the crossover interaction was reduced by one-half. Four graphical approaches to visualizing the environmental clusters in this data set also were considered. Multi-dimensional scaling (MDS) allowed visualization of clusters when the dimensionality of the crossover space was reduced by considering only some of the crossover interactions between pairs of cultivars. Another benefit of MDS may be identification of specific environmental variables associated with crossover interactions
A comparison of data fusion techniques for target detetction with a wide azimuth sonar
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1995.Includes bibliographical references (p. 133).by Kent Russell Engebretson.M.S
Characteristics of Effective Leaders in Economic Development: An Exploratory Study
Donna K. Fisher, Ph.D., is an assistant professor, School of Economic Development, College of Business Administration, Georgia Southern University, Statesboro, GA 30460-8152.
Russell Kent, Ph.D., is a professor, Department of Marketing & Logistics. College of Business Administration, Georgia Southern University, Statesboro, GA 30460-8154.
Linda Nottingham, ABD, is an instructor, Central Florida College, Winter Park, FL 32789.
J Robert B. Field, Ph.D., is an assistant professor of marketing, Algoma University College, Sault Ste. Marie, Ontario P6A 2G4, Canada
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