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Articles 1441 - 1470 of 1490

Full-Text Articles in Chemistry

Maine Acid Rain Study : Reports, Maine Department Of Environmental Protection Feb 1987

Maine Acid Rain Study : Reports, Maine Department Of Environmental Protection

Maine Collection

Maine Acid Rain Study : Reports

Maine Department of Environmental Protection, Augusta, Maine (February, 1987).

Contents: Acid Rain Precursor Inventory and Evaluation / Modeled Sulfur Deposition in Maine / High Elevation Lake Monitoring in Maine


Anomalous Concentrations Of Co-58 And Cs-137 In Dardanelle Reservoir, David M. Chittenden Ii Jan 1986

Anomalous Concentrations Of Co-58 And Cs-137 In Dardanelle Reservoir, David M. Chittenden Ii

Journal of the Arkansas Academy of Science

The unforseen occurrence of significant concentrations of Co-58 and Cs-1 37 in a quiescent backwater of Dardanelle Reservoir provided an opportunity to observe the equilibrium distribution of Cs-1 37 between solution and suspended solids. This equilibrium has not been observed in other areas of the reservoir because small amounts of this nuclide are regularly injected into the lake by the AP&L Nuclear I facility. The systematics of the Co-58 concentration lead to the conclusion that significant amounts of these two nuclides had been injected into the sampling area from a source unknown.


The Thirsty Earth: Acid Rain - A Sour Drink, Margaret R. Souza Jul 1985

The Thirsty Earth: Acid Rain - A Sour Drink, Margaret R. Souza

Bridgewater Review

No abstract provided.


A Proposal To Fertilize The Overton Arm And Gregg Basin Areas Of Lake Mead, Larry J. Paulson Nov 1984

A Proposal To Fertilize The Overton Arm And Gregg Basin Areas Of Lake Mead, Larry J. Paulson

Publications (WR)

Several limnological studies have been conducted in Lake Mead during the past decade. The recent studies clearly show that most of Lake Mead is deficient in nutrients, especially phosphorus, and very low in productivity. The reservoir-wide average total phosphorus concentration for 1981 - 1982 was only 9 mg/m3. This is below levels found In most oligotrophic lakes and reservoirs. Algal biomass, as measured by chlorophyll-a, averaged only 1.5 mg/m3. That also places Lake Mead in the oligotrophic range. Transparency, as measured by a Secchi disc, averaged 9-5 m in Lake Mead during 1981-1982. That far exceeds …


Las Vegas Wash Multispectral Scanner Survey, T. H. Mace, M. V. Olsen, Environmental Protection Agency Feb 1984

Las Vegas Wash Multispectral Scanner Survey, T. H. Mace, M. V. Olsen, Environmental Protection Agency

Publications (WR)

At the request of the U.S. Bureau of Reclamation, Boulder City, Nevada, the U.S. Environmental Protection Agency's Environmental Monitoring Systems Laboratory at Las Vegas collected multispectral scanner imagery of Las Vegas Wash on October 1, 1982. A combined maximum likelihood classification and editing procedure was used to classify the multispectral scanner imagery into 12 categories of land cover. The classification identified four categories of marsh vegetation, one category of riparian, two categories of mixed scrub, and two desert categories. Turbid water and cultivated land formed an "other" category. Area tabulations were formed by georeferencing the classification to the Universal Transverse …


Soil Acidity On High Rainfall Pastures, J S. Yeates, D. A. Mcghie, I. R. Wilson Jan 1984

Soil Acidity On High Rainfall Pastures, J S. Yeates, D. A. Mcghie, I. R. Wilson

Journal of the Department of Agriculture, Western Australia, Series 4

Most soils of the high rainfall area of south-western Western Australia are naturally acis.

The most acid group of soils, the peaty sands. have been routinely limed before subterranean clover pastures were established since research in the 1950s showed that poor Rhizobium nodulation could be overcome with the application of about 2 tonnes per hectare of coastal limesand.


Soil Acidity In The Eastern Wheatbelt, W M. Porter, I. R. Wilson Jan 1984

Soil Acidity In The Eastern Wheatbelt, W M. Porter, I. R. Wilson

Journal of the Department of Agriculture, Western Australia, Series 4

In Western Australia parts of the sandplain of the eastern wheatbelt are very acid and produce poor crops, It was not until the late 1970s that the effect of soil acidity on the productivity of the sandplain soils was examined in any detail.

Since then researchers have learnt a great deal about the nature of soil acidity in the eastern wheatbelt sandplain soils and can suggest management options for farmers.

This article discisses the problem of the very acid soils. It does not deal with the moderately acid, medium textured soils of the eastern wheatbelt. Although the acidity of these …


Soil Acidity And Liming In The Lower Great Southern, R N. Glencross, M. G. Clarke Jan 1984

Soil Acidity And Liming In The Lower Great Southern, R N. Glencross, M. G. Clarke

Journal of the Department of Agriculture, Western Australia, Series 4

In the 375 to 750 millimetre rainfall area of the Lower Great Southern, reports of loss of subterranean clover from established pastures, reduced carrying capacity for sheep and increasing soil acidity lead to the establishment in 1981 of a research programme into the effects of soil acidity on pasture productivity in that region.


Sulphur Needs Of Crops And Pastures, J S. Yeates Jan 1984

Sulphur Needs Of Crops And Pastures, J S. Yeates

Journal of the Department of Agriculture, Western Australia, Series 4

Sulphur deficiency has long been recognised as a potential problem of legume pastures in the higher rainfall areas (over 750 mm a year) of south-west Western Australia. Before the introduction of granulated superphosphate (about 1970), sulfer deficiencies commonly developed in spring on susceptible soils despite autumn applications of superphosphate (containing about 10.5 per cent sulphur).

In loww and medium rainfall areas sulphur deficiency is rarely reported, at least partly because of annual superphosphate applications. However large areas of the sandy-surfaced soils of Western Australia would become sulphur deficient for pastures and crops if sulphur inputsd in fertilisers were substantially reduced. …


The Combined Effect Of Cu And Zn On Selenastrum Capricornutum, Helmer Colonia-Roque May 1983

The Combined Effect Of Cu And Zn On Selenastrum Capricornutum, Helmer Colonia-Roque

Dissertations and Theses

It has been demonstrated that the toxicity of heavy metals depends on their chemical speciation and can be related to their free ion activities, rather than the total metal concentrations. The objective of this study was to determine the effect of combined free ions of zinc and copper on the toxicity to the green alga Selenastrum capricornutum. This alga was grown in a defined medium, under controlled laboratory conditions, with a varying range of zinc and copper concentrations. The growth rate of the alga was inhibited at pZn = 5.93 or at pCu = 7.24. The results suggest that …


The Effects Of Impoundments On Salinity In The Colorado River, Larry J. Paulson, John R. Baker Jan 1983

The Effects Of Impoundments On Salinity In The Colorado River, Larry J. Paulson, John R. Baker

Publications (WR)

The increase in salinity of our western rivers has been identified as one of the most serious water quality problems in the nation. This is of special concern in the Colorado River where salinity has increased from pristine levels estimated at 380 mg/1 to present-day levels of 825 mg/1 at Imperial Dam. Flow depletions, associated with decreased runoff and increased evaporation and diversions, coupled with high salt loading from natural and man-created sources are considered the primary causes for rising salinity in the river. The urban and agricultural development projected to occur in the basin through this century could deplete …


Use Of Hydroelectric Dams To Control Evaporation And Salinity In The Colorado River System, Larry J. Paulson Jan 1983

Use Of Hydroelectric Dams To Control Evaporation And Salinity In The Colorado River System, Larry J. Paulson

Publications (WR)

The main stem reservoirs on the Colorado River comprise one of the largest and most heavily used freshwater bodies in the nation. These reservoirs (Lake Powell, Lake Mead, Lake Mohave and Lake Havasu) can store up to 53,590,400 acre-feet of water at their maximum capacities. Nonetheless, local water shortages still exist in some areas of the Colorado River Basin. There is also concern that salt concentrations are approaching levels that could severely affect municipal and agricultural uses. Water shortages will become even more acute as demands for water increase with continued urban and agricultural development in the basin. Water conservation …


Development, Verification And Use Of Methods To Model Chemical And Thermal Processes For Lakes Mead And Powell, John Eric Edinger, Edward M. Buchak, Joseph S. Norton, Bureau Of Reclamation Jun 1982

Development, Verification And Use Of Methods To Model Chemical And Thermal Processes For Lakes Mead And Powell, John Eric Edinger, Edward M. Buchak, Joseph S. Norton, Bureau Of Reclamation

Publications (WR)

Analysis and development of carbonate-bicarbonate chemical subroutine.


Diagenesis Of Organic Matter In Las Vegas Bay And Bonelli Bay, Lake Mead, James W. Murray, Carolyn J. Jones, Kathy Kuivila, Jeff Sawlan Jul 1981

Diagenesis Of Organic Matter In Las Vegas Bay And Bonelli Bay, Lake Mead, James W. Murray, Carolyn J. Jones, Kathy Kuivila, Jeff Sawlan

Publications (WR)

The interstitial water chemistry of the sediments of Las Vegas Bay and Bonelli Bay in Lake Mead has been studied as part of a comprehensive water quality study of those locations. Pore water and solid phase analyses were completed from four stations in Las Vegas Bay and two stations in Bonelli Bay. At both locations the pore water compositions and organic matter diagenesis in the sediments are dominated by sulfate reduction. This major role of sulfate reduction is unusual for lake sediments and reflects the fact that SO4 is the major anion in the lake water. In addition, gypsum …


Isolation And Characterization Of Frullanolide From Frullania Franciscana (Howe), Marshall Stuart Sass Mar 1981

Isolation And Characterization Of Frullanolide From Frullania Franciscana (Howe), Marshall Stuart Sass

Dissertations and Theses

Investigation of the ether extract of the liverwort Frullania franciscana (Howe) resulted in the isolation of the sesquiterpene lactone frullanolide. The separation techniques of thin-layer chromatography, dry column chromatography, and liquid column chromatography were evaluated. Only liquid column chromatography was found useful. Fractions from alumina liquid column separations had infrared spectra which resembled the published spectrum of frullanolide. The identity of the compound obtained from F. franciscana (Howe) was established after extensive purification by comparison of its infrared and nuclear magnetic resonance spectra with published spectra of frullanolide.


Influence Of Las Vegas Wash Density Current On Nutrient Availability And Phytoplankton Growth In Lake Mead, John R. Baker, Larry J. Paulson Jun 1980

Influence Of Las Vegas Wash Density Current On Nutrient Availability And Phytoplankton Growth In Lake Mead, John R. Baker, Larry J. Paulson

Publications (WR)

Density currents are commonly formed in reservoirs because of temperature or salinity induced density differences between inflowing and receiving waters. Anderson and Pritchard (1951) were among the first to demonstrate this in their investigations of density currents in Lake Mead. They found that the Colorado River formed an underflow in Lake Mead during the winter, an overflow in the spring and an interflow in the summer and fall. Wunderlich and Elder (1973) have since described the hydromechanics of these types of flow patterns, and density currents have been reported for several other large reservoirs (Carmack et al. 1979, Johnson and …


Chemistry Of The Spring Waters Of The Ouachita Mountains Excluding Hot Springs, Arkansas, George H. Wagner, Kenneth F. Steele Mar 1980

Chemistry Of The Spring Waters Of The Ouachita Mountains Excluding Hot Springs, Arkansas, George H. Wagner, Kenneth F. Steele

Arkansas Water Resources Center Technical Reports

This report is based on the chemical analysis of the waters from 93 springs and 9 wells. Springs, when free from metal plumbing, provide an uncontaminated source of the ground water and it was desired to obtain water uncontaminated with metals. A few wells were added to the list, usually because of their unique location in the sampling grid.


The Limnological Status Of Lake Mead And Lake Mohave Under Present And Future Powerplant Operations Of Hoover Dam, Larry J. Paulson, John R. Baker, James E. Deacon, U.S. Water And Power Resources Service Jan 1980

The Limnological Status Of Lake Mead And Lake Mohave Under Present And Future Powerplant Operations Of Hoover Dam, Larry J. Paulson, John R. Baker, James E. Deacon, U.S. Water And Power Resources Service

Publications (WR)

The ever-increasing demand for energy in the southwest has led to a search for additional sources of power generation. Coal-fired powerplants currently provide most of the baseline energy in the southwest, but this must be supplemented with hydroelectric power during periods of peak demand. In order to provide additional peaking power, the U.S. Bureau of Reclamation is considering a number of projects to modify existing hydroelectric facilities, or add new facilities in the Lake Mead Recreation Area. The Hoover Powerplant Modification Feasibility Investigation was authorized by Congress on December 16, 1975 to determine the feasibility of: (i) adding one or …


Concentrations Of Total Dissolved Solids And Selected Cations In Dardanelle Lake, Arkansas, David M. Chittenden Ii Jan 1980

Concentrations Of Total Dissolved Solids And Selected Cations In Dardanelle Lake, Arkansas, David M. Chittenden Ii

Journal of the Arkansas Academy of Science

No abstract provided.


Factors Affecting The Sr-90 Concentration In Dardanelle Lake, Arkansas, David M. Chittenden Ii Jan 1980

Factors Affecting The Sr-90 Concentration In Dardanelle Lake, Arkansas, David M. Chittenden Ii

Journal of the Arkansas Academy of Science

No abstract provided.


Transport Of Ozone Across An Air/Water Interface Coupled With Aqueous Decomposition, Ahmad Ali Mehrabzadeh Jan 1980

Transport Of Ozone Across An Air/Water Interface Coupled With Aqueous Decomposition, Ahmad Ali Mehrabzadeh

Dissertations and Theses

Photoacoustic spectroscopy was used to analyze the transport of ozone through the air/water interface. Experimental results showed that the ozone transport rate is similar to rates measured for other gases of low solubility and low reactivity. The transport rate increases with increasing pH. The decomposition rate of ozone was studied in solutions. The decomposition rate also depends on the pH of the solution, and in high pHs both the deposition velocity and the decomposition rate constant of ozone have larger values. The value of the deposition velocity (Kd) is 3.7 ± .9 x 10-3 cm/sec and the decomposition rate …


The Concentration And Speciation Of Sugars In Natural Waters, Minoo Shakerin Sweet May 1979

The Concentration And Speciation Of Sugars In Natural Waters, Minoo Shakerin Sweet

Dissertations and Theses

Due to the importance of carbohydrates in biological systems, many efforts have been made to develop a quantitative method for analysis of carbohydrates in natural waters. The low concentrations of dissolved sugars in natural waters require a sensitive analytical method. In this study, gas chromatography of alditol acetate derivatives of sugars was investigated for quantitative and qualitative analysis of individual dissolved sugars in natural waters. The alditol acetate derivatives of sugars give only one derivative for each sugar, yielding qualitative and quantitative results.

The detection limit was 25 nM for each sugar. Because of this very low detection limit, only …


Lake Mead And Lake Powell Salinity Reports, Cathy Lee, Steve Gazafy Feb 1979

Lake Mead And Lake Powell Salinity Reports, Cathy Lee, Steve Gazafy

Publications (WR)

The enclosed reports were compiled for the Colorado River Water Quality Office based on salinity data for Lake Mead and Lake Powell. According to the regional director of the office, the reports are not considered "polished" documents for public distribution. However, he considers them to be "interesting, rough appraisals of general trends that may be very important In our understanding the hydro-salinity system in the Colorado River."


Determination Of The Rate Of Formation Of Hcn, Mitchell Hull Nov 1977

Determination Of The Rate Of Formation Of Hcn, Mitchell Hull

Honors Theses

Nitric oxide is a major air pollutant arising from fossil fuel combustion, yet the fuel contribution to its formulation is uncertain. Since, in combustion, fossil fuels undergo disintegration before oxidation takes place, the study of the pyrolsis of a model constituent of fossil fuels can shed light on NO formation. The rate of inert pyrolytic disappearance of pyridine and the rate of formation of the principal Nitrogen-containing pyrolytic product, HCN, was studied in an inert atmosphere. The rate constant for the formation of HCN and its temperature dependence were determined.


A Review Of The Limnology Of And Water Quality Standards For Lake Mead, Charles R. Goldman Oct 1976

A Review Of The Limnology Of And Water Quality Standards For Lake Mead, Charles R. Goldman

Publications (WR)

1. The waters of Las Vegas Bay, a heavily utilized recreational resource, receive discharges from a variety of municipal and industrial waste sources. The U.S. Environmental Protection Agency has determined, on the basis of numerous studies, that the present water quality violates state and federal standards and constitutes a public nuisance. Consultants have advised the Sewage and Wastewater Advisory Committee that rapid abatement of the alleged pollution conditions can be achieved by an advanced wastewater treatment (AWT) plant.

2. The major problems in Las Vegas Bay are an objectionable water color, excessive turbidity, noxious odors, and oxygen depletion in certain …


Bulletin No 3993 - The Control Of Saffron Thistle, G. A. Pearce Jun 1976

Bulletin No 3993 - The Control Of Saffron Thistle, G. A. Pearce

Bulletins - 3000 - 3999

Saffron thistle is a primary noxious weed and is widespread throughout the drier parts of Western Australia. When growing in pasture its prickly growth habit discourages animals from grazing amongst it so that its presence results in the loss of feed. In crops it reduces yield and results in dockage when seed is found in harvested grain.


A Systems Study Of Oil Pollution Abatement And Control For Portland Inner And Outer Harbor, Casco Bay, Maine, Arthur D. Little, Inc. Mar 1976

A Systems Study Of Oil Pollution Abatement And Control For Portland Inner And Outer Harbor, Casco Bay, Maine, Arthur D. Little, Inc.

Maine Collection

A Systems Study of Oil Pollution Abatement and Control for Portland Inner and Outer Harbor, Casco Bay, Maine

to State of Maine, Department of Environmental Protection, State House Augusta, Maine 04330

Appropriation Number 4320-4001

by Arthur D. Little, Incorporated, 20 Acorn Park, Cambridge, Massachusetts 02140 (March 15, 1976).

Contents: Executive Summary / 1. Introduction / 2. Identification of Vulnerable Resources / 3. Potential Oil Spill Locations / 4. Oil Spill Movement / 5. Containment and Disposal Systems / 6. Oil Monitoring Systems / 7. Marine Navigation In Portland Inner and Outer Harbors / Appendices



Cadmium In Kittitas County Soils, Don G. Muller Jan 1973

Cadmium In Kittitas County Soils, Don G. Muller

All Master's Theses

This paper deals with a survey of soil cadmium concentrations in Kittitas County, Washington, using atomic absorption spectrophotometry as the analytical method. The purpose of the survey was to establish, in an area relatively free from cadmium contamination, background levels for a wide variety of soil conditions. The results showed cadmium concentrations ranging from amounts below the detection limit in remote areas to 2.58ppm in cultivated, inhabited areas, with an overall average concentration of 0.12 ppm cadmium


Final Report On Interrelationships Between Chemical, Physical And Biological Conditions Of The Waters Of Las Vegas Bay Of Lake Mead, James E. Deacon, Richard W. Tew Jan 1973

Final Report On Interrelationships Between Chemical, Physical And Biological Conditions Of The Waters Of Las Vegas Bay Of Lake Mead, James E. Deacon, Richard W. Tew

Publications (WR)

This program was a status study of the interaction between Las Vegas Wash, an enriched stream, and Las Vegas Bay, a wedge shaped arm of one of the world's deeper reservoirs. The program centered primarily on identification and counting of planktonic algae from several points in Las Vegas Bay. Additional work on nutrient enrichment of water samples was conducted to aid in interpretation of algal distribution related to nutrient input. Examination of a variety of physical, chemical, and biological parameters, both at many surface points in the bay, as well as in vertical profile, was also accomplished and further aided …


Reaction Of Aqueous Catechol Solutions With Minerals, Boonthong Poocharoen Jan 1972

Reaction Of Aqueous Catechol Solutions With Minerals, Boonthong Poocharoen

Dissertations and Theses

The effectiveness of catechol, an aromatic vic-diol, in dissolving silicate minerals was studied. A synthetic amorphous magnesium trisilicate, Mg₂Si₃O₈∙5H₂O, as well as the minerals olivine, sepiolite, diopside, augite, and enstatite were used to react with catechol in slightly acidic, basic, and neutral solutions. It was found, depending on the solvent used, that 33-52, 8-17, 14-30, 5-11, 3-6, and 0.5-1 % of the minerals dissolved, respectively.

The reaction with Mg₂Si₃0₈·5H₂0 resulted in the formation of crystals of magnesium tris (catecholato) siliconate nonahydrate Mg[Si(Cat)₃]∙9H₂0. Dehydration of the crystals at room temperature resulted in the loss of 6 moles of water to form …