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Articles 46141 - 46170 of 52497
Full-Text Articles in Physical Sciences and Mathematics
The Nebraska Natural Heritage Program: Two Year Progress Report, Mary Clausen, Mike Fritz, Gerry Steinauer
The Nebraska Natural Heritage Program: Two Year Progress Report, Mary Clausen, Mike Fritz, Gerry Steinauer
Nebraska Game and Parks Commission: White Papers, Conference Presentations, and Manuscripts
Since European settlement, human activities have totally eliminated the natural vegetation from approximately 50 percent of Nebraska’s landscape, and of that remaining most has been heavily impacted. As a result, numerous plants and animals have been extirpated from the state and many others are threatened.
The destruction of Nebraska’s natural diversity resulted in both public and private conservation groups recognizing the need for a centralized and accessible biological database for the state’s rare species and natural community types. Toward this end, the Nebraska Natural Heritage Program (NENHP) was established in August, 1987 through a cooperative effort between The Nature Conservancy …
Hypoxia In The Lower Rappahannock Estuary, Albert Y. Kuo, Mohamed Z. Moustafa
Hypoxia In The Lower Rappahannock Estuary, Albert Y. Kuo, Mohamed Z. Moustafa
Reports
There are several objectives to this study. The immediate objective is to collect a comprehensive and consistent set of field observations to better describe the hypoxic condition in the Rappahannock River. Other objectives can be classified as short and long term goals.
Long term: (1) Identify and quantify the processes contributing to the dissolved oxygen budget in deep waters, and explain the variabilities among the three Virginia major tributary estuaries. (2) Provide information for resource management so that the James River can be protected from hypoxic problems and, perhaps, the problems in the York and Rappahannock Rivers can be alleviated. …
Simulation Of The Fate Of Nitrogen From The Disposal Of Poultry Litter, H. D. Scott
Simulation Of The Fate Of Nitrogen From The Disposal Of Poultry Litter, H. D. Scott
Arkansas Water Resources Center Technical Reports
A PC/AT computer model was developed to simulate the transport of water, nitrate and ammonia in the soil profile after an application of poultry litter to pasture. The model was written using FORTRAN 77 compiler and can be used on any IBM type compatible computer with a math coprocessor. Poultry litter has been shown to be a potential source of plant nutrients, but mismanagement can result in nitrate pollution of the surface and groundwater. The model is composed of a main program, 11 subroutines and three subprograms. An example was shown of the flexibility and dynamic nature of the computer …
Determining Pesticide And Nitrate Levels In Spring Water In Northwest Arkansas, T. L. Lavy, B. A. Dehart, John D. Mattice
Determining Pesticide And Nitrate Levels In Spring Water In Northwest Arkansas, T. L. Lavy, B. A. Dehart, John D. Mattice
Arkansas Water Resources Center Technical Reports
Occurrences of pesticides in our nations ground water are on the rise. As states become aware of this problem and begin monitoring programs, incidence of contamination will probably increase. Since the problem of pesticides in groundwater is relatively new, little research has centered on the fate of pesticides after they reach the groundwater environment. In Northwest Arkansas efforts to monitor groundwater for pesticides have been small. Twenty-five springs in Northwest Arkansas were sampled in the fall of 1988, and spring of 1989. Analysis for atrazine, alachlor, metolachlor, diuron, and simazine in spring water was preformed using gas liquid chromatography and …
Analysis, Design And Implementation Of A Pilot Relational Database For Groundwater In The State Of Arkansas, Ray Hashemi-Nassab
Analysis, Design And Implementation Of A Pilot Relational Database For Groundwater In The State Of Arkansas, Ray Hashemi-Nassab
Arkansas Water Resources Center Technical Reports
There are several agencies within the state of Arkansas dealing with underground water. Each agency has its own database that acts as an isolated depository of data. Practically, the communication among these databases is zero, not because there is no need for it, but because the communication is very difficult if not impossible. Data redundancy, inconsistency, and lack of integrity is overwhelming. In this study we have addressed the problem of lack of unity among the databases belonging to different agencies. Also, as an alternative we have developed a relational database. In this database the data was normalized to 4NF. …
An Expert System For Managing An Activated Sludge Wastewater Treatment Plant, Sandra C. Parker, David G. Parker
An Expert System For Managing An Activated Sludge Wastewater Treatment Plant, Sandra C. Parker, David G. Parker
Arkansas Water Resources Center Technical Reports
A diagnostic expert system for an activated sludge wastewater treatment plant has been designed to link with a relational database management system for obtaining operational parameter values that are used by the program to diagnose operational problems that may occur in the process. The problems that are dealt with by the system are bulking sludge, floating sludge, defloculation, ashing, solids washout, foaming problems, high soluble effluent BOD and problems in the aeration system. The link between the expert system and the database is accomplished via programming that is initiated by the expert system program. The operator of the system is …
Presentation Of Verified Algal Taxa As Reference Sources, Richard L. Meyer
Presentation Of Verified Algal Taxa As Reference Sources, Richard L. Meyer
Arkansas Water Resources Center Technical Reports
A data base of the algae of Arkansas ecoregions has been established to describe the numerous taxa that occur within the aquatic ecosystems included in these regions. The organisms were identified with the aid of diverse literature from throughout the world. These sources are written in multiple languages and the living organisms had to be compared with outline or silhouette drawings. These illustrations may include shading, but none present the true color of the organism but only the characteristics of the descriptive source. Primary characteristics used to identify algae is based upon pigmentation of the plastid and the number and …
Improving Irrigation Scheduling And Water Use Efficiency In Cotton, Derrick M. Oosterhuis
Improving Irrigation Scheduling And Water Use Efficiency In Cotton, Derrick M. Oosterhuis
Arkansas Water Resources Center Technical Reports
Cotton (Gossypium hirsutum L) is an important crop in the southern United States. The crop is grown in both irrigated and rainfed situations and is seldom free from periods of water shortages at some stage during the season. In recent years the need for consistency in yields and a stable cash flow has resulted in a rapid expansion in the number of irrigated acres of cotton in the Mississippi Delta. Irrigation research has, however, not kept pace with this expansion. This project represents a start at meeting this urgent need. The influence of weather patterns necessitates that these studies be …
Minimizing The Potential For Groundwater Contamination From Agricultural Point Sources, Joseph H. Massey, Terry L. Lavy, John D. Mattice
Minimizing The Potential For Groundwater Contamination From Agricultural Point Sources, Joseph H. Massey, Terry L. Lavy, John D. Mattice
Arkansas Water Resources Center Technical Reports
An activated charcoal filtration unit was designed to remove pesticides from leftover pesticide solutions and rinsates generated under farm-like conditions. The system, fabricated for less than $1400 using readily available components, effectively removed the pesticides atrazine, benomyl, carbaryl, fluometuron, metolachlor, and trifluralin from wastewater generated on the University of Arkansas Agronomy Farm located in Fayetteville, AR. A total of 2253 L of wastewater were treated using the system. Of these 1768 L were generated from washing out the spray tank (rinsates) while 485 L stemmed from leftover pesticide solutions that were mixed, but not applied. Typical initial pesticide concentrations in …
Thermal Decomposition Of 1,1,2- Trichloroethane In Hydrogen In Tubular Flow Reactors At Atmospheric Pressure, Chen-Chung Yeh
Thermal Decomposition Of 1,1,2- Trichloroethane In Hydrogen In Tubular Flow Reactors At Atmospheric Pressure, Chen-Chung Yeh
Theses
The decomposition of 1,1,2-trichloroethane in a hydrogen gas bath was carried out at 1 atmosphere total pressure in three different surface to volume ratio flow reactors. Temperature ranged from 440 to 850 °C and the residence times studied were in the range 0.2 - 2.3 seconds. Application of the first order rate expression to this data yields a linear relationship for each temperature studied and thus global rate constants for loss of reactant were determined.
It was found that conversion of the reagent was a function of both temperature and residence time. The major products observed are 1, 2-dichloroethylene (CHClCHCl), …
Study Of An Analytical Method For Benzo(A)Pyrene Metabolites In Human Urine, Zheng Ouyang
Study Of An Analytical Method For Benzo(A)Pyrene Metabolites In Human Urine, Zheng Ouyang
Theses
A method developed by Becher and Bjorseth for analysis of PAH metabolites in urine was employed to investigate human exposure to benzo(a)pyrene (BaP) - an ubiquitous environmental carcinogen. Preliminary results are presented showing the relationship between exposure to BaP and urinary elimination. Although the correlation between the two variables is not statistically significant, there appears to be a positive association with selected exposure varibles such as smoking. The identification of an association may establish urinary BaP as a marker of exposure.
However, detailed study of the analytical procedure indicated that recoveries with this method were as low as 3-8% for …
Microwave Treatment Of Organic Contaminated Soil, Suning Fan
Microwave Treatment Of Organic Contaminated Soil, Suning Fan
Theses
The development of microwave technology to treat hazardous wastes hasbeen in progress at NJIT for the past three years. The initial stagesof this program have focused on determining the' breadth of hazardouswaste problems that are amenable to microwave technology applications.Benchscale studies have shown the following processes are technicallypossible:
a. It is possible to steam strip organic volatiles from soil;
b. Volatiles can be destroyed by impact upon lossy so lids
c. Heavy metal ions can be immobilized in soil;
d. It is possible to regenerate GAC on-site.
e. It is possible to pyrolyze polyarmotic compounds in soil in-site,and, thereby, effect …
Investigation Of Major Mutagenic Substances In Airborne Particulate Matter : Biologically-Driven Analysis Of Fractions And Analysis Of Polycyclic Aromatic Hydrocarbons (Pahs) Nitro-Pahs And Other Classes Of Compounds, Jung-Hen Lwo
Theses
A modified fractionation scheme involving acid-base partitioning and silica gel column chromatography has been used as the first step in the bioassay-directed search for significant levels of mutagenic compounds in extracts of inhalable (IP10) ambient air particulates. The biologically "hot" fractions were separated and analyzed chemically or subfractionated to isolate and concentrate "hot" subfractions which were then chemically analyzed by GC/MS FTIR, and HPLC equipped with UV, Fluorescence and Photodiode Array UV detectors.
The Ames assay of mutagenicity has involved the unactivated TA98 strain of Salmonella and enzyme-activated (TA98+S9) assays. In addition, some assays have been performed in this present …
Organics In Ambient Air By Collection On Tenax, Thermal Desorption,And Capillary Chromatography With Parallel Fid/Ecd Analysis, Chih-Hsiang Liao
Organics In Ambient Air By Collection On Tenax, Thermal Desorption,And Capillary Chromatography With Parallel Fid/Ecd Analysis, Chih-Hsiang Liao
Theses
Volatile organics in ambient air were regularly collected on Tenax cartridges at high (10 ml/min) and low (5 ml/min) intake flows. These Tenax samples were analyzed by using a Tekmar Automatic Thermal Desorber and capillary GC system with parallel flame ionization (FID) and electron capture detectors (ECD). A series of quality assurance procedures has been established to improve and assure the accuracy and precision of sample collector and analysis. These procedures relate to performance of the Tekmar thermal desorber, recovery efficiency from the Tenax, and include studies on breakthrough and co-elution. The results demonstrate (1) that from ambient air data …
Investigation Of Benzo(A)Pyrene In Outdoor Air, Indoor Air And Personal Inhalation Air, Hsiu-Wen Chen
Investigation Of Benzo(A)Pyrene In Outdoor Air, Indoor Air And Personal Inhalation Air, Hsiu-Wen Chen
Theses
The assessment of human exposure to an environmental contaminant requires the measurement of the concentrations levels present in each pathway of possible contact.
This was an investigation of human exposure to an environmental pollutant, benzo(a)pyrene, in outdoor air, indoor air and personal inhalation air samples. The analytical procedure involved extraction by ultrasonic and separation by thin layer chromatography, and detection by fluorescence. The resulting data was used to develop a profile of indoor and outdoor human exposure to B(a)P during the year.
Characterization Of Activated Sludge Immobilized In Calcium Alginate Gel With Respect To Biodegradation Of 2-Chlorophenol And Benzene, Manjari Singh
Characterization Of Activated Sludge Immobilized In Calcium Alginate Gel With Respect To Biodegradation Of 2-Chlorophenol And Benzene, Manjari Singh
Theses
Activated sludges acclimated with phenol and 2-chlorophenol in one case, and a mixture of benzene, toluene, and o, in and p-xylene in another case, were characterized for biodegradation of 2-chlorophenol and benzene, respectively. Activated sludge was obtained from the Parsippany-Troy Hills Water Pollution Control Plant (NJ).
For both cases colonies were isolated before acclimation, after acclimation, and at the end of biodegradation studies. Since the unacclimated group was the same in both cases, there were a total of five different groups for which characterization was carried out.
For all the five groups together, a total of 54 isolates were obtained …
Thermal Desorption Of Hazardous And Toxic Organic Compounds, Manuel S. Nolau
Thermal Desorption Of Hazardous And Toxic Organic Compounds, Manuel S. Nolau
Theses
The purpose of this thesis is to study the thermal desorption behavior of toxic organic compounds, specifically o-xylene, p-xylene, ethyl benzene, p-chlorotoluene, and anthracene, from soil with respect to temperature and time, and to develop a mathematical model that will describe this desorption behavior. The model will allow prediction of the concentration of an organic contaminant in commercial soil desorption system over time given a known set of parameters of the specific chemical as well as flow rate and temperature. For this purpose, two sets of experiments were done: These are identified as 1. Thermal desorption and 2. plug flow …
Thermal Desorption Of Hazardous And Toxic Organic Compounds From Soil Matrices, Sarah Calandra
Thermal Desorption Of Hazardous And Toxic Organic Compounds From Soil Matrices, Sarah Calandra
Theses
The purpose of this research project was to determine feasiblity to remove organic contaminants from various soil matrices by thermal desorption and gas purge. The volatization and gas purge of organic contaminants from the soil increases under the influence of heat and inert gas.
The work was done in two parts. First, under isothermal conditions, organic compounds were injected as a plug unto columns that contained real or simulated soil matrices. These columns were continuously purged with a carrier gas (nitrogen) and a gas chromatogragh equipped with Flame Ionization Detector but no added column other than the soil was used …
Microbial Competition In The Biodegradation Of Phenol, Mary Ellen Frank
Microbial Competition In The Biodegradation Of Phenol, Mary Ellen Frank
Theses
Three phenol degraders were isolated from the mixed liquor of the Livingston, NJ municipal treatment plant. Shaker flask experiments using one of the degraders (a Pseudomonas sp.) resulted in the determination of its kinetic rate constants. The second phenol degrader (a Xanthamonas) lost its phenol degrading ability while being stored, and its kinetic rate constants could not be determined. The third phenol degrader (a Pseudomonas cepacia) formed flocs which interfered with the spectrophotometric determination of biomass and therefore its kinetic rate constants also could not be determined.
Mixed culture experiments were carried out using a the Pseudomonas sp. and a …
The Case Of Rose Island: An Example Of Conflicting Goals And Competing Jurisdictions In Coastal Zone Development, Thomas James Gibson
The Case Of Rose Island: An Example Of Conflicting Goals And Competing Jurisdictions In Coastal Zone Development, Thomas James Gibson
Marine Affairs Theses and Major Papers
The purpose of this paper is to investigate the methods and tactics employed at the local level by all of the participants in the resolution of a controversial coastal development issue. It is the author's goal to present a case study of a proposal that had progressed at least through the local level of the approval process and study the mechanism to see if it produces a socially desirable result. Resolution of the final form that the development of Rose Island will take is no closer today than it was in the Spring of 1986, so this paper necessarily has …
Toxicokinetics And Toxicodynamics Of Pyrethroid Insecticides In Fish, Steven P. Bradbury, Joel R. Coats
Toxicokinetics And Toxicodynamics Of Pyrethroid Insecticides In Fish, Steven P. Bradbury, Joel R. Coats
Steven P. Bradbury
The pyrethroid insecticides are extremely toxic to fish, with 96—h LC50 values generally below 10 μg/L and i.p. and i.v. LD50 values below 20 mg/kg. Corresponding LD50 values in mammals and birds are in the range of several hundred to several thousand milligrams per kilogram. This review examines pyrethroid toxicokinetics and toxicodynamics in fish as critical factors associated with species selectivity. Studies with permethrin, cypermethrin and fenvalerate have established that rates of metabolism and elimination in rainbow trout are significantly lower than those reported for birds and mammals. Comparatively low lethal brain pyrethroid concentrations and nonneural aspects of pyrethroid intoxication …
The Prairie Naturalist Volume 21, No.2 June 1989
The Prairie Naturalist Volume 21, No.2 June 1989
The Prairie Naturalist
THE MISSISSIPPI KITE IN THE ENVIRONMENTAL HISTORY OF THE SOUTHERN GREAT PLAINS ▪ E. G. Bolen and D. L. Flores
TAPE-RECORDED CHICK CALLS TO LOCATE GRAY PARTRIDGE NESTS ▪ J. P. Carroll
BORROW DISTRIBUTION OF THE THIRTEEN-LINED GROUND SQUIRREL IN GRAZED MIXED-GRASS PRAIRIE: EFFECT OF ARTIFICIAL HABITAT STRUCTURE ▪ D. W. Kaufman and G. A. Kaufman
PIPING PLOVERS NESTING AT NELSON RESERVOIR, MONTANA ▪ D. W. Prellwitz, T. A. Prellwitz, K. L. Stutzman, and J. W. Stutzman
CHRISTMAS BIRD COUNTS FOR NORTH DAKOTA - 1988 ▪ R. N. Randall
CHANGING HABITATS IN THE PLATTE RIVER VALLEY OF NEBRASKA ▪ J. …
Management, Foraging Behavior, Diet Composition And Forage Quality Of Free-Ranging But Herded Camels In Ceeldheer District, Central Somalia, Ahmed A. Elmi
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
In Somalia, camel (Camelus dromedarius) survivability and milk production has been higher than for other domestic livestock and contributes substantially to the subsistence of Somali pastoralists. The objective of this research was to study management, foraging behavior and nutrition of camels in their natural habitat to determine how production continues under seasonal nutritional stress.
Management systems of Ceeldheer pastoralists are based on available natural pasture and water. The natural rotation grazing system maintained an ecological equilibrium in the District.
Pastoralists manipulate their herds to suit existing environmental conditions, family needs and labor availability for herding. In herd management, …
The United Nations Convention On The Law Of The Sea, And Canadian Official Development Assistance, Lennox O'Riley Hinds
The United Nations Convention On The Law Of The Sea, And Canadian Official Development Assistance, Lennox O'Riley Hinds
Marine Affairs Theses and Major Papers
The purpose of this paper is to examine the needs of developing states created by the 1982 U.N. Convention on the Law of the Sea and the capability of the above cited Canadian aid agencies to provide needed assistance. To achieve the above objective the articles of the Third Convention of the Law of the Sea will be analyzed to establish requirements that coastal states must satisfy when the convention comes into force. Next, the mandates, policies, and programs of the aforementioned agencies will be examined to ascertain their potential to assist developing countries meet their obligations under UNCLOS III. …
Total Maximum Daily Loads And Waste Load Allocations For Las Vegas Bay: Rationale And Calulations, State Of Nevada: Division Of Environmental Protection
Total Maximum Daily Loads And Waste Load Allocations For Las Vegas Bay: Rationale And Calulations, State Of Nevada: Division Of Environmental Protection
Publications (WR)
In September 1987 the Nevada Division of Environmental Protection revised Water Quality Standards for Las Vegas Wash (LVW) and Lake Mead. Standards were set for chlorophyll-a and unionized ammonia in Las Vegas Bay (LVB) (NDEP 1987). The 1986 and 1987 LVB data showed non-achievement of both the chlorophyll-a and unionized ammonia standard which triggered an analysis of total phosphorus and total ammonia Total Maximum Daily Loads and Waste Load Allocations which are presented in this report.
This report is separated into three sections:
1. 1987 Las Vegas Bay Water Quality Conditions and Seasonal Periodicity.
2. Concentration Estimates at Northshore Road …
Cultural Resource Inventory And Testing In The Salt Creek Pocket And Devils Lane Areas, Needles District, Canyonlands National Park, Utah, Betsy L. Tipps, Nancy J. Hewitt, P-Iii Associates, Inc.
Cultural Resource Inventory And Testing In The Salt Creek Pocket And Devils Lane Areas, Needles District, Canyonlands National Park, Utah, Betsy L. Tipps, Nancy J. Hewitt, P-Iii Associates, Inc.
All U.S. Government Documents (Utah Regional Depository)
This document is the final technical report on the first phase of a multiyear archeological program conducted in Canyonlands National Park. Some of the purposes of this project are to gather information for upgrading the park's interpretive program, increase the scientific understanding of Canyonlands' prehistory, and prepare a research design to guide future investigation. Archeological inventory of 4500 acres in the Needles District revealed a previously undocumented Archaic occupation and showed that Formative peoples using the area were primarily the Mesa Verde Anasazi, not the Fremont and Anasazi as previously thought. The data also indicate that prehistoric peoples used the …
Determination Of Marina Buffer Zones Using Simple Mixing And Transport Models : A Report To The Virginia State Dept. Of Health, Bureau Of Shellfish Sanitation As Part Of The Chesapeake Bay Initiatives Marine Pollution Abatement Initiative, John M. Hamrick, Bruce J. Neilson
Determination Of Marina Buffer Zones Using Simple Mixing And Transport Models : A Report To The Virginia State Dept. Of Health, Bureau Of Shellfish Sanitation As Part Of The Chesapeake Bay Initiatives Marine Pollution Abatement Initiative, John M. Hamrick, Bruce J. Neilson
Reports
This report describes the rationale, development and application of simple mixing and transport models for the determination of marina buffer zones and buffer zones for other point source discharges. Included in the report are two computer programs for implementation of the most general two dimensional transport model.
Root Exploitation Of Fertile Soil Microsites, Robert B. Jackson
Root Exploitation Of Fertile Soil Microsites, Robert B. Jackson
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Root exploitation of enriched soil microsites was examined for the tussock grasses Agropyron desertorum and Agropyron spicatum and the shrub Artemisia tridentata. Two mechanisms of exploitation of the microsites were examined: root proliferation and changes in nutrient uptake capacity. One day after nutrient solution was applied to small soil patches, the mean relative growth rate of Agropyron desertorum roots in enriched patches was two to four times greater than for roots of the same plants in soil patches treated with distilled water. This rapid and striking root proliferation occurred in response to N-P-K enrichment as well as to P or …
Modeling Forest Dynamics Based On Stand Level Resource Allocation, Geoffrey Candler Poole
Modeling Forest Dynamics Based On Stand Level Resource Allocation, Geoffrey Candler Poole
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
An ecologically based model of forest succession is presented. In the model, trees compete for a share of limited growth resources available from their environment. Competition is reflected by each tree's effect on the resource pool and is not explicitly modeled. Model parameters were fit to field data from subalpine forests of the Rocky Mountains. A technique for estimating model parameters from understory-tolerance rankings and silvical characteristics of each species is also presented. The model's output was consistent with our current understanding of forest dynamics. Emergent properties of the model also mimicked natural processes such as self-thinning, release, and maximum …
Using Computer Imaging To Assess Visual Impacts Of Forest Insect And Disease Pests, Daniel Rabin
Using Computer Imaging To Assess Visual Impacts Of Forest Insect And Disease Pests, Daniel Rabin
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Forest insect and disease pests alter the appearance of trees, thereby impacting visual resources. Because of the complexity of most forest landscapes, the degree of visual impact of pest-infested forest stands is difficult to quantify.
This paper describes a method of measuring visual impacts of pest-infested forest stands. Photographs of healthy Ponderosa pine trees were entered into a computer video-image-processing system. Using this system, images of trees were altered to simulate different degrees of infestation by limb rust, a forest pathogen.
The altered and unaltered images were shown to groups of observers who rated the scenes in terms of "scenic …