Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Water

Discipline
Institution
Publication Year
Publication
Publication Type
File Type

Articles 751 - 780 of 780

Full-Text Articles in Physical Sciences and Mathematics

Nebraska's Water Supply Map Including Groundwater In Storage, Total Water Withdrawals, Precipitation, And Outflow As Of 1969 Jan 1969

Nebraska's Water Supply Map Including Groundwater In Storage, Total Water Withdrawals, Precipitation, And Outflow As Of 1969

Conservation and Survey Division

No abstract provided.


The Influence Of Thermo-Gradients Upon Water Movement And Retention In Unsaturated Soils, Jose V. Salazar May 1967

The Influence Of Thermo-Gradients Upon Water Movement And Retention In Unsaturated Soils, Jose V. Salazar

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Temperature differences of about 5, 10, and 15 V, were applied to uniformly packed and insulated horizontal column of Millville silt loam soil using mean temperatures near 13, 14, 15, 16, 17, 18, 19, 20 and 23.5 C. The temperature distribution along the soil column was determined using copper constantan thermocouples. Soil samples were taken to determine volumetric moisture content, and soil water potential, using the vapor pressure psychometer technique. The thermodynamic flow equation of Taylor and Cary, (1964) was used to calculate the hydro-thermal transfer coefficient (ß) as given by:

-ß = d(μw)T / dlnT

where …


The Influence Of Soil Moisture Regimes And Atmospheric Environments On Transpiration And The Energy Status Of Water In Plants, Sampatrao A. Gavande May 1966

The Influence Of Soil Moisture Regimes And Atmospheric Environments On Transpiration And The Energy Status Of Water In Plants, Sampatrao A. Gavande

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Plant responses to different soil moisture regimes have been extensively studied. Because of interactions between the soil, plant and climatic factors, few convincing generalizations concerning the influence of soil water on the transpiration of water by plants have been established. Generally single factors or at most the interaction of two have been studied at any one time. Useful theories describing the conditions of water retention in plant tissues and movement of water through plants have been proposed. Equally useful theories have been suggested for describing the retention and transmission of water in soil. The integration of these theories and their …


Simultaneous Movement Of Water And Herbicides In Unsaturated Soils, Ming-Shyong Yang May 1966

Simultaneous Movement Of Water And Herbicides In Unsaturated Soils, Ming-Shyong Yang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Since weed killers were developed in the early part of the decade beginning in 1940, herbicides have been increasing in use until they are now widely used to control weeds. The application of herbicides has thus become a regular agricultural and ecological practice.


Simultaneous Flow Of Heat And Water In Plant Tissue, Gaylon Sanford Campbell May 1966

Simultaneous Flow Of Heat And Water In Plant Tissue, Gaylon Sanford Campbell

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Although biological phenomena may be partially described in a general way without the use of mathematics and physics, the experimental results may be more meaningful if they are analyzed on the basis of physical and mathematical laws. The complexity of biological systems has made the application to them of mathematics and physics rather difficult, and only recently has much progress been made. Although it has yet been possible to describe only a few simple biological systems by actual equations, a great deal of qualitative information may be obtained by applying physics and mathematics. Russell (1960, p. 439) said

In principle …


The Interaction Of Water And Salt Flow In Unsaturated Soils, Mahmoud Hassan Abd-El Aziz May 1964

The Interaction Of Water And Salt Flow In Unsaturated Soils, Mahmoud Hassan Abd-El Aziz

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The movements of salt and water, particularly in fairly dry soils or compacted shales, are important processes in both agronomic studies and hydraulics of deep ground water which is important in the location of oil.


Irrigation: Soil-Plant-Water Relationships, Soil Conservation Service, Engineering Division Mar 1964

Irrigation: Soil-Plant-Water Relationships, Soil Conservation Service, Engineering Division

All U.S. Government Documents (Utah Regional Depository)

Soil-Plant-Water relationships describes those properties of soils and plants that affect the movement, retention, and use of water essential to plant growth. This publication attempts to provide engineers the basic data necessary to plan and maintain efficient conservation irrigation practices to provide a permanent irrigated agriculture engineering principles and research findings have been screened to give emphasis to the information needed to design, install, and operate irrigation systems on farms or groups of farms.


Salt Effect On Water Requirements Of Plants, Abdel-Wahhab M. H. Sallam May 1963

Salt Effect On Water Requirements Of Plants, Abdel-Wahhab M. H. Sallam

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Water requirement was defined by Briggs and Shantz in 1911 as the ratio of the weight of water absorbed by a plant during its growth to the weight of dry matter produced. Ballard (1933) and Williams (1935) defined water requirement as the ratio of the amount of water transpired to the amount of dry matter produced. Ballard (1933) and Williams (1935) defined water requirement as the ratio of the amount of water transpired to the amount of dry matter formed during the whole or any part of the life cycle of the plant. Miller (1938) and Kramer (1959) postulated that …


Pressure Dependence Of Soil Water Matric Potential, Bozorg Bahrani May 1963

Pressure Dependence Of Soil Water Matric Potential, Bozorg Bahrani

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The partial specific Gibbs1 free energy or the chemical potential has been shown to be the most desirable thermodynamic function for describing soil-water systems. The absolute value of the chemical potential of soil water cannot be determined. If pure water at standard temperature and pressure is taken as the reference, the difference between the chemical potential of soil water and that of the reference can be measured and is called "soil water potential," which has the dimension of energy per unit mass.

The barometric pressure at the sea level has been accepted as the standard reference pressure. Thus, any …


The Influence Of Temperature On The Impedance To Water Flow Through Plants, Royal Duane Jensen May 1961

The Influence Of Temperature On The Impedance To Water Flow Through Plants, Royal Duane Jensen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This era has been termed the atomic or space age. The greatest concern of most people seems to be centered around survival from the destruction and suffering that might be caused by atomic and nuclear weapons. However, along with this, the world is confronted with perhaps a greater disaster--a potential calamity seldom realized by most people, yet a problem which grows more serious in the world each year--a tragedy which would probably be worse than destruction from nuclear weapons. This encroaching catastrophe is starvation.

Even today the majority of the people in the world do not have enough food. Each …


Water For Man, Sterling A. Taylor Jan 1961

Water For Man, Sterling A. Taylor

Faculty Honor Lectures

Man's uses for water are rapidly increasing. His demands and needs for water for his personal use and for cleanliness, recreation, industry, and food production are increasing as the population and standard of living rise. At the same time, his knowledge of the behavior and nature of water is increasing.


The Peltier Effect And Its Use For Measuring Relative Activity Of Soil Water, Hans C. Korven May 1958

The Peltier Effect And Its Use For Measuring Relative Activity Of Soil Water, Hans C. Korven

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Soil moisture measurement embraces two basic concepts, namely, water content and relative activity. The measurement of moisture content, either on a weight or volume basis, yields the amount or quantity of water in the soil. The measurement of relative activity or the energy required to remove unit of water is related to the availability of the soil moisture to the plant. The measurement of soil bulk density, irrigation efficiency, and the amount of water to apply in an irrigation are a few examples that require the use of the moisture content concept. Whereas the first concept determines the amount of …


An Application Of A Thermodynamic Flow Equation To Water Movement In Unsaturated Soil, Brennan Derry Soane May 1958

An Application Of A Thermodynamic Flow Equation To Water Movement In Unsaturated Soil, Brennan Derry Soane

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The movement of water in soil presents many interesting problems to the research worker. It is also a subject which finds wide and important application in agriculture and several branches of engineering.

The object of this work was to examine the usefulness of a new equation of flow of water in unsaturated soil. If valid, this new approach may be able to eliminate some of the gaps in our present knowledge of the subject.

All soil lying above the capillary fringe of a water table is in the unsaturated state with respect to water. This means that in any macroscopic …


Preliminary Estimate Of The Underflow Across The South Dakota-Nebraska State Line In The Niobrara River And Ponca Creek Drainage Basins, E. C. Reed, C. F. Keech Nov 1957

Preliminary Estimate Of The Underflow Across The South Dakota-Nebraska State Line In The Niobrara River And Ponca Creek Drainage Basins, E. C. Reed, C. F. Keech

Conservation and Survey Division

The purpose of this paper is to estimate the amount of ground water flowing across the South Dakota-Nebraska State line within the Niobrara River basin, including the Ponca Creek basin. The study was made at the request of the Niobrara River Compact Commission. The estimates fiven in the paper are preliminary and subject to revision.


Great Salt Lake Diking Project, Large Plan, Hydrology And Quality Of Water Study, United States Department Of Interior, Bureau Of Reclamation Mar 1955

Great Salt Lake Diking Project, Large Plan, Hydrology And Quality Of Water Study, United States Department Of Interior, Bureau Of Reclamation

Elusive Documents

The purpose of this study was to determine the feasibility of diking a portion of the Great Salt Lake for purposes of using the fresh water for irrigation, industrial uses, and recreation. This study approached the problem only for a hydrologic and quality of water standpoint.


The Freezing Point Of Water In Puddled And Unpuddled Soils At Different Soil Moisture Tension Values, Robert B. Campbell May 1951

The Freezing Point Of Water In Puddled And Unpuddled Soils At Different Soil Moisture Tension Values, Robert B. Campbell

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A technique that will adequately describe the physical condition of water in the soil has long been desired by scientists. The method should include the effect of soluble materials on the osmotic pressure of the soil solution, and also the effect of surface force action between the soil and soil water.

Parker (8) demonstrated that the freezing point was reduced in the presence of finely divided material. This suggested the possibility of using the cryoscopic procedure to measure the physical condition of water soil. More recently, the introduction of Thermistors for accurate temperature measurement have made it desirable to investigate …


The Integration Of Water Use In Nebraska, G. E. Condra Feb 1947

The Integration Of Water Use In Nebraska, G. E. Condra

Conservation and Survey Division

No abstract provided.


Land And Water Conservation Problems Of The Missouri River Basin, G. E. Condra Jan 1945

Land And Water Conservation Problems Of The Missouri River Basin, G. E. Condra

Conservation and Survey Division

No abstract provided.


Terminology Relating To The Occurrence, Behavior And Use Of Water In Nebraska, G. E. Condra Jun 1944

Terminology Relating To The Occurrence, Behavior And Use Of Water In Nebraska, G. E. Condra

Conservation and Survey Division

No abstract provided.


Water Resources Of Nebraska Jan 1941

Water Resources Of Nebraska

Conservation and Survey Division

No abstract provided.


A Study Of The Equilibria Between Bentonite And The Various Replacing Agents In Alcoholic And Water Solutions, Joel E. Fletcher May 1937

A Study Of The Equilibria Between Bentonite And The Various Replacing Agents In Alcoholic And Water Solutions, Joel E. Fletcher

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Investigators in soils have long recognized the importance of the colloidal fraction of soil, and also the almost inseparable problem of replaceable bases. It is generally accepted that the replaceable base fraction of a colloid controls to a large degree the physical properties exhibited by it. Volumes of work have been written on the problem of controlling the reactions of this fraction and on studies of the properties exhibited by it when it is saturated with various cations. Each worker has proceeded in his own individual way or followed the example set by some previous worker with specific modifications.


Conservation Of Land And Water Resources Of Nebraska, G. E. Condra Dec 1936

Conservation Of Land And Water Resources Of Nebraska, G. E. Condra

Conservation and Survey Division

No abstract provided.


Water-Bearing Formations Of Nebraska, G. E. Condra, E. C. Reed Jan 1936

Water-Bearing Formations Of Nebraska, G. E. Condra, E. C. Reed

Conservation and Survey Division

No abstract provided.


Water, W. J. Mayo Jan 1935

Water, W. J. Mayo

Journal of the Minnesota Academy of Science

In the hope of stimulating interest in the problem of water, I wish to devote a few minutes to some of the physical properties of water.


Lincoln's Water Supply Problem Oct 1930

Lincoln's Water Supply Problem

Conservation and Survey Division

No abstract provided.


Drainage Districts Of Southeastern Nebraska, Calvin Turner Moore Jan 1917

Drainage Districts Of Southeastern Nebraska, Calvin Turner Moore

Conservation and Survey Division

Throughout certain parts of the United States the importance of drainage is receiving increased recognition each year. The scope of investigations and operations covers many localities that are affected with "springy" lands, swamps, shallow lakes, overflowed lands, and tide lands.


The Storage And Use Of Soil Moisture. Report Of Experimental Substation, North Platte, Nebraska, W. W. Burr Jul 1914

The Storage And Use Of Soil Moisture. Report Of Experimental Substation, North Platte, Nebraska, W. W. Burr

Nebraska Agricultural Experiment Station: Historical Research Bulletins

The profitable cultivation of the non-irrigable lands in west central and western Nebraska is limited by the amount and efficient use of the precipitation. There are tracts of land in the sand hills and minor tracts of badly worn heavier soils where the need of soil fertility is becoming evident. But, in the main, the great problem at present is not one of soil fertility, but of how to get enough water to make use of the fertility now present. The rainfall of this section, which varies from an actual shortage to seldom more than a meager sufficiency, makes it …


Bulletin No. 115 - The Movement Of Water In Irrigated Soils, J. A. Widtsoe, W. W. Mclaughlin May 1912

Bulletin No. 115 - The Movement Of Water In Irrigated Soils, J. A. Widtsoe, W. W. Mclaughlin

UAES Bulletins

This bulletin embodies a part of the data secured in the irrigation investigations of this Station. It aims to contribute something to our knowledge of the movement of water in irrigated soils . The science of irrigation can not well be built until the laws involved in the mutual relationships of waters, soils and crops are understood with fair accuracy. Much has been done by numerous investigators, during the last fifty years, to give a clearer comprehension of the movement of soil moisture; but the field experiments have dealt largely with saturated soils, and the laboratory experiments have seldom taken …


The Water Supply Of Minneapolis, James A. Dodge, C. L. Herrick, C. W. Hall Jan 1886

The Water Supply Of Minneapolis, James A. Dodge, C. L. Herrick, C. W. Hall

Journal of the Minnesota Academy of Science

No abstract provided.


Some Impurities In Drinking Water, George Weitbrecht Dec 1880

Some Impurities In Drinking Water, George Weitbrecht

Journal of the Minnesota Academy of Science

The more we know about the causes of disease the more we are convinced that many of the ills that flesh is heir to come to us through germs that are transmitted through the air we breath, the water we drink and the food we eat. You are all familiar with the westward march of cholera among men and epizooty among animals. In surgical operations the danger is not from the operation, but from germs which are in the air and which get into the body through the wound, producing surgical fever, etc. Since Lester used the carbolic acid spray …