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Articles 51271 - 51300 of 52381

Full-Text Articles in Physical Sciences and Mathematics

The Jornada Validation Site (Playa- Nmsu Ranch) Validation Study, Walter G. Whitford, John Ludwig Jan 1971

The Jornada Validation Site (Playa- Nmsu Ranch) Validation Study, Walter G. Whitford, John Ludwig

Progress reports

No abstract provided.


Validation Studies At Deep Creek, Curlew Valley Validation Study, G. W. Minshall, F. L. Rose, D. A. Andrews, D. M. Shaw Jan 1971

Validation Studies At Deep Creek, Curlew Valley Validation Study, G. W. Minshall, F. L. Rose, D. A. Andrews, D. M. Shaw

Progress reports

No abstract provided.


Models Of Ingestion Rates For Desert Biome Rodents Process Study, Donald R. Johnson Jan 1971

Models Of Ingestion Rates For Desert Biome Rodents Process Study, Donald R. Johnson

Progress reports

No abstract provided.


Role Of Algae In Crust Formation In Desert Soils Process Studies, Raymond I. Lynn, Roy E. Cameron Jan 1971

Role Of Algae In Crust Formation In Desert Soils Process Studies, Raymond I. Lynn, Roy E. Cameron

Progress reports

No abstract provided.


Autecological Studies Of Atriplex Confertifolia And Eurotia Lanata Process Study, Martyn M. Caldwell, Neil E. West, Peter J. Goodman Jan 1971

Autecological Studies Of Atriplex Confertifolia And Eurotia Lanata Process Study, Martyn M. Caldwell, Neil E. West, Peter J. Goodman

Progress reports

No abstract provided.


Environmental Changes Produced By Cold-Water Outlets From Three Arkansas Reservoirs, Carl E. Hoffman, Raj V. Kilambi Jan 1971

Environmental Changes Produced By Cold-Water Outlets From Three Arkansas Reservoirs, Carl E. Hoffman, Raj V. Kilambi

Technical Reports

Water qualities of two natural streams (Buffalo and Kings Rivers), one new coId-tailwater (Beaver), and two old coId-tailwaters (Norfork and Bull Shoals) in northwestern Arkansas were studied from July 1965 through October 1968. The essential difference between the old cold-tailwaters and natural streams is a change in water quality which allows the development of a new productive ecological environment. Features which typify the old tailwaters are as follows: (1) relatively homioithermal temperatures; (2) stream beds scoured by strong hydoelectric power generation currents; (3) abundant phytoplankton and benthic macroinvertebrates; and (4) absence of warm water game fishes. Environmental factors characterizing natural …


Anclote Environmental Project Report 1971, Marine Science Institute, University Of South Florida Jan 1971

Anclote Environmental Project Report 1971, Marine Science Institute, University Of South Florida

Reports

The sub-discipline reports which follow represent a considerable body of data on the Anclote environment. In general the results provide additional support for many of the conclusions stated or implied in the Annual Report for 1970 (op. cit.). The considerable diversity and complexity of the Anclote estuary and Anchorage including the major role of the grassbeds is now documented in some detail. The overall results also support previous recommendations concerning power plant construction and design (op. cit.).


Land Levelling With Scrapers, K R. Southon Jan 1971

Land Levelling With Scrapers, K R. Southon

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

A VARIETY of earth-moving equipment can be used in preparing land for flood irrigation, but the best machine for extensive earth moving over some distance is a power-driven, carry-all scraper.


The Flathead Catfish In Unchannelized And Channelized Missouri River, Nebraska, Larry A. Morris, Ralph Langemeier, Arthur Witt Jr. Jan 1971

The Flathead Catfish In Unchannelized And Channelized Missouri River, Nebraska, Larry A. Morris, Ralph Langemeier, Arthur Witt Jr.

Nebraska Game and Parks Commission: White Papers, Conference Presentations, and Manuscripts

Flathead catfish, Pylodictus olivaris (Rafinesque), were studied in approximately 83.7 km of unchannelized and 67.6 km miles of channelized Missouri River. Growth rates were slower in the unchannelized section than they were in the channelized section. The oldest fish in the unchannelized section was 25 years old, while in the channelized study area the oldest was 10 years. In the pectoral spines of progressively older fish from both sections, enlargement of the lumen obliterated early annuli. Much of the annual increment of growth was accomplished during June, July and August. Males became sexually mature at 3 to 4 years of …


Simple Evaporimeter For Timing Trickle Irrigation, C R. Coffman Jan 1971

Simple Evaporimeter For Timing Trickle Irrigation, C R. Coffman

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

DIFFERENCES in soil types and size of trees in orchards make it impossible to give a single recommendation for trickle irrigation running time.

Daily running time for each situation can be simply and fairly accurately calculated from weekly readings of an easily constructed evaporimeter.


Study Of Channel Sediments, James River & Hampton Roads Area, R. J. Huggett Jan 1971

Study Of Channel Sediments, James River & Hampton Roads Area, R. J. Huggett

Reports

Bottom sediment samples were collected from 3 locations transecting the channel in the lower James and Elizabeth rivers.


A Comparative Limnological Study Of Three East Central Illinois Farm Ponds, Charles W. Furrey Jan 1971

A Comparative Limnological Study Of Three East Central Illinois Farm Ponds, Charles W. Furrey

Masters Theses

A comparative limnological study was conducted at three east central Illinois farm ponds between March 15 and September 18, 1970, to determine the incidence of nitrogen and phosphorus in the ponds resulting from agricultural sources. All ponds had corn, soybean, winter wheat cropping systems on their watersheds. Corn accounted for the greatest fertilizer application. One pond had significant numbers of livestock on its watershed that contributed high amounts of nitrogen and phosphorus to its waters. Limnological parameters measured at the surface, mid depth, and bottom of a ten foot water column in each pond were water temperature, dissolved oxygen, carbon …


Impoundment Effects On Water Quality As Reflected In Parasitism Of Reservoir Basses, David A. Becker Jan 1971

Impoundment Effects On Water Quality As Reflected In Parasitism Of Reservoir Basses, David A. Becker

Technical Reports

Our aquatic environments are rapidly becoming useless as natural resources through pollution from various sources. It is therefore necessary for us to further understand the various means which relate to this process. The interrelationships between the physico-chemical and biological water qualities undergo marked changes during the ageing of a reservoir. Eutrophication of these impoundments render them rela-tively useless as natural resources. It thus becomes apparent that we must gain further knowledge of these processes if we are to devise methods for proper reservoir management.


The Behavior Of Pvc Pipe Under The Action Of Water Hammer Pressure Waves, Gary Z. Watters Jan 1971

The Behavior Of Pvc Pipe Under The Action Of Water Hammer Pressure Waves, Gary Z. Watters

Reports

Introduction: Hydraulic transients, commonly referred to as water hammer, occur in a hydraulic system whenver the velocity of flow in any one of the pipes in the system is caused to change. The magnitude of the pressure waves generated by a given change in velocity depends on the geometry of the pipe system, the magnitude of the velocity change and the elastic wave velocity in the system componenets. In turn, the elastic wave velocity depends on the modulus of elasticity of the fluid and the pipe material, the size and thickness of the pipe, the method by which the pipe …


A Computer Model Of The Quantity And Chemical Quality Of Return Flow, Jimmie L. Thomas, J. Paul Riley, Eugene K. Israelsen Jan 1971

A Computer Model Of The Quantity And Chemical Quality Of Return Flow, Jimmie L. Thomas, J. Paul Riley, Eugene K. Israelsen

Reports

A hybrid computer program is developed to predict the water and salt outflow from a river basin in which irrigation is the major water user. A chemical model which predicts the quality of water percolated through a soil profile is combined with a general hydrologic model into form the system simulation model. The chemical model considers the reactions that occur in the soil, including the exchange of calcium, magnesium, and sodium cations on the soil complex, and the dissolution and precipitation of gypsum and lime. The chemical composition of the outflow is a function of these chemical processes within the …


Development Of A Procedure For Determining Spacial And Time Variations Of Precipitation In Venezuela, Luis E. Ramirez Jan 1971

Development Of A Procedure For Determining Spacial And Time Variations Of Precipitation In Venezuela, Luis E. Ramirez

Reports

An analysis of the influence of the length of the record in the reliability of mean values of precipitation was made for the Caracus-Cagigal Station in Venezuela. Ten series of values were obtained for 10, 15, 20, 25, 30, and 35-year periods, extracted for sliding intervals for the overall record of 75 years. The reliability of mean values computer from Figure 3 was quite low for 10, 15, and 20- year periods. The long term record means had higher reliability, increasing with the number of years in the records, but the differences are not important in terms of accuracy. Precipitation …


Detergent And Non-Detergent Phosphorus In Sewage, Donald B. Porcella, E. J. Middlebrooks Jan 1971

Detergent And Non-Detergent Phosphorus In Sewage, Donald B. Porcella, E. J. Middlebrooks

Reports

Introduction: Quantitative data on nutrient levels in sewage from homes which are using heavy-duty detergents and which have been restrcited from using such detergents is necessary before rational decisions on the removal of phosphorus from detergetn can be made. Furthermore, the effect of various standard sewage treatment schemes on phosphorus levels should be evaluated to determine the relative cost of such treatment. Then the cost (to society, the environment, and to the taxpayer) of phosphorus removal from detergent and/or from sewage effluents can be estimated and such data utilized to make the appropriate policy decisions. The report herein presented is …


Water Resources Planning And Social Goals: Conceptualization Toward A New Methodology, D. Peterson, H. Caulfield, R. D'Arge, D. Gordon, M Marts, T. Roefs, R. Roelofs Jan 1971

Water Resources Planning And Social Goals: Conceptualization Toward A New Methodology, D. Peterson, H. Caulfield, R. D'Arge, D. Gordon, M Marts, T. Roefs, R. Roelofs

Reports

A modeling concept relating water resource use to


The Effect Of Carbon On Algal Growth--Its Relationship To Eutrophication, Joel C. Goldman, Donald B. Porcella, Joe E. Middlebrooks, Daniel F. Toerien Jan 1971

The Effect Of Carbon On Algal Growth--Its Relationship To Eutrophication, Joel C. Goldman, Donald B. Porcella, Joe E. Middlebrooks, Daniel F. Toerien

Reports

Introduction: Natural and cultural eutrophication (enrichment with nutrients) frequnetly results in excessive algal growths thereby reducing the beneficial uses of surface waters (Hasler, 1947; Thomas, 1955, Edmondson et al., 1956, Oswald and Golueke, 1966, Skulberg, 1967, Mackenthun et al., 1968, Goldman and Armstrong, 1969, McGauhey et al., 1968,1969, 1970a, 1970b). Recent reviews emphsize that the prevention of further reduction in the quality of water resources requires the implementation of effective control measures (Goldman, 1965, Steward and Rohlich, 1967, Middlebrooks et al., 1969, Rohlich, 1969). Effective control of cultural eutrophication must involve the manipulation of those factors which affect algal growth, …


Application Of Operations Research Techniques For Allocation Of Water Resources In Utah, Calvin G. Clyde Jan 1971

Application Of Operations Research Techniques For Allocation Of Water Resources In Utah, Calvin G. Clyde

Reports

In this report a methodology is described for determining the optimal allocation of water supplies in the State of Utah to minimize the cost of meeting an assumed set of water requirements. A linear programming model was formulated to represent the ten interconnected hydrologic study areas of the state. The comprehensive model considers virtually all uses, areas, sources, transfers and costs of water. The model has 204 constraints and 3378 variables and was solved by the simplex method. Included in the results are the following: the optimal water allocation or the groundwater, surface water, and water transfers which minimize the …


A Computerized Method Of Precipitation Data Quality Control, Ronald H. Campbell Jan 1971

A Computerized Method Of Precipitation Data Quality Control, Ronald H. Campbell

Reports

A computerized data quality check and data edit program has been developed to aid in the processing of telemetered precipitation data. The logic considerations and program development are discussed and results are displayed. This effort has resulted in successful editing of large amounts of precipitation data gathered by automated remote data acquisition techniques. The application of this processing routine has resulted in reducing data editing costs to about three percent of that required to do the work manually.


Extending Utility Of Non-Urban Water Supplies, Jay M. Bagley Jan 1971

Extending Utility Of Non-Urban Water Supplies, Jay M. Bagley

Reports

Extending the utility of an existing water supply in any river basin suggests a management-planning approach under three general guiding principles: (1) minimize depletions wherever possible (thereby maintaining a greater manageable quantity with subsequent potential to satisfy more uses); (2) generally preserve, protect, and improve water quality (thereby retaining its itility for use by a wider variety of potential users); and (3) make carefully considered allocations (thereby assuring multiples duty, more optimal sequencing, and shifts in use to conform to current and projected soil preferences). There are many technological and managerial techniques that can be employed to implement these principles. …


Population Dynamics Of Ospreys In Tidewater Virginia, Robert Senior Kennedy Jan 1971

Population Dynamics Of Ospreys In Tidewater Virginia, Robert Senior Kennedy

Dissertations, Theses, and Masters Projects

No abstract provided.


Tree Establishment In The Wheatbelt, F Batini Jan 1971

Tree Establishment In The Wheatbelt, F Batini

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

Although most of the Forests Department's activity has centred around the State Forests in the higher rainfall areas, the Department has, for many years, encouraged the planting and conservation of trees throughout the farming areas.


Trickle Irrigation, B Swan Jan 1971

Trickle Irrigation, B Swan

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

THE introduction of trickle irrigation has caused tremendous interest among commercial irrigators. While not a new concept, its application was formerly restricted to glasshouse and nursery use.


Nutrient Transport In The Lake Poinsett System, Jack M. Skille Jan 1971

Nutrient Transport In The Lake Poinsett System, Jack M. Skille

Electronic Theses and Dissertations

Concentrations and loads of nutrients transported through the Lake Poinsett system were monitored from April 1, 1970 to April 1, 1971. An annual 2.07x 10~ m3 surface discharge into Lake Poinsett transported 1.66 x 104 kg (PO4) phosphorus, 1.28 x 104 kg nitrate nitrogen, and 3.90 x 104 kg organic carbon. The Big Sioux River-Dry Lake system contributed 63% of the phosphorus, 45% of the nitrate nitrogen, and 43% of the organic carbon load. The remaining portion entered Lake Poinsett from the Lake Albert drainage. Of the annual load of nutrients transported into Lake Poinsett, 33% of the nitrate nitrogen …


Seasonal Movements And Behavior Of Ring-Necked Pheasants In Eastern South Dakota, Arthur V. Carter Jan 1971

Seasonal Movements And Behavior Of Ring-Necked Pheasants In Eastern South Dakota, Arthur V. Carter

Electronic Theses and Dissertations

Information was gathered on mobility, behavior, and related activities of pheasants from July 1966 to July 1968 by banding and/or marking 160 birds with backtags and radio transmitters. Food was readily available since the winters were mild with little snow. Birds moved less than 1/4 mile from roosting areas to cornfields and weed patches to feed. Numbers of birds dispersing from the study area in spring varied each of the years, but 60 to 70 remained there during the two reproductive seasons. Adult cocks traveled less than 1/4 mile when dispersing-and adult hens moved less than 1/2 mile. Movements by …


Effects Of Dieldrin On The Social Interactions Of Penned Pheasants And Chickens, Nancy Hayden Field Jan 1971

Effects Of Dieldrin On The Social Interactions Of Penned Pheasants And Chickens, Nancy Hayden Field

Electronic Theses and Dissertations

Studies to determine the effects of dieldrin on social hierarchy of pheasants and chickens were initiated in 1970. Social interactions were observed among groups of pheasant chicks, adult cock and hen pheasants and peck-order development among groups of young pheasants. To determine the effects of dieldrin on the pecking behavior of individual birds, pairs of pheasants and pairs of chickens were placed in a neutral cage. When patterns of dominance and subordination were consistent, dieldrin in capsules (4 mg to pheasants and 6 and 10 mg to chickens twice weekly) was given to one member of each pair and birds …


Phytoplankton Dynamics Of Two Northern Prairie Lakes And Possible Relations To Dissolved Nutrients, Alan B. Hauber Jan 1971

Phytoplankton Dynamics Of Two Northern Prairie Lakes And Possible Relations To Dissolved Nutrients, Alan B. Hauber

Electronic Theses and Dissertations

Phytoplankton populations in Enemy Swim Lake were observed to be quite different. Although these lakes lie within the same geographic area (Coteau des Prairies), major differences in water quality were recorded. The differences in water quality were reflected in the phytoplankton populations and appeared to be influenced by the agricultural practices on the watersheds. Enemy Swim Lake was basically a diatom lake while Lake Herman contained mostly blue-green algae. Genera of algae found in Enemy Swim Lake were: Anabaena, Aphanizomenon, Lyngbya, Pediastrum, Staurastrum, Dinobyron, Asterionella, Fragilaria, Melosira, Stephanodiscus, and Ceratium. All of the above genera occurred in Lake Herman except …


A Comparison Of Aspen And Pine Communities In The Northern Black Hills, Jeremiah J. Kranz Jan 1971

A Comparison Of Aspen And Pine Communities In The Northern Black Hills, Jeremiah J. Kranz

Electronic Theses and Dissertations

Three study areas, each containing an aspen (Populus tremuloides) community, a pine (Pinus ponderosa) community, and a mixed aspen-pine community, were studied during the summers of 1968, 1969, and 1970. Soil chemistry, plant chemistry, overstory density, understory production, and use by whitetail deer (Odocoileus virginianus) and cattle (Bos taurus) were determined for each community in each study. Pine and aspen communities of one study area were sampled for soil and plant chemistry. Soil phosphate and potassium levels were higher in the aspen community, while soil nitrates were higher in the pine community. Soil pH was similar to the two communities. …