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

Digital Commons Network™

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

Physical Sciences and Mathematics

Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 291211 - 291240 of 294374

Full-Text Articles in Entire DC Network

Microorganisms And Soil Structure, T. M. Mccalla Mar 1950

Microorganisms And Soil Structure, T. M. Mccalla

Department of Agronomy and Horticulture: Faculty Publications

SUMMARY

Laboratory tests were made to determine the effectiveness of different compounds and microbial groups in increasing the stability of Peorian loess lumps against the action of falling water drops. The influence of these on percolation tests in the laboratory was also determined.

Many organic substances-dextrose, sucrose, starch, peptone, cullulose, and gum arabic-did not themselves contribute directly to soil-structure stability, though these substances do furnish energy material for soil microorganisms, which can convert them readily into either microbial tissue or decomposition products that increase soil-structure stability. Lignin, proteins, oils, fats, waxes, resin, and paraffin increased the stability of lumps of …


Public Health Reports, Clarence M. Tarzwell Feb 1950

Public Health Reports, Clarence M. Tarzwell

United States Environmental Protection Agency: Publications

Preliminary tests with DDT for the control of mosquitoes, forest insects, and agricultural pests demonstrated that it was toxic to a wide variety of animal life. Because there were indications that the new insecticide would be widely used, apprehension was expressed by some groups that its extensive or indiscriminate use would cause extensive harm to wildlife.

The desirability of carefully controlled use was early recognized by those in charge of extensive programs for the control of insects of public health importance. A joint statement of policy for the use of DDT issued early in 1945 (1) by the Army and …


Physical Properties Of The Ternary System: Ethylene Glycol - Disthylene Glycol - Water, Robert Marvin Tombaugh Jan 1950

Physical Properties Of The Ternary System: Ethylene Glycol - Disthylene Glycol - Water, Robert Marvin Tombaugh

Master's Theses or Doctor of Nursing Practice

Since approximately two-thirds (12) of the energy from the fuel in automobile engines is converted to unusable heat, it is necessary that a method of cooling the engines be provided. In most present-day engines of this type, an indirect method is utilized, namely, the transfer of heat to a liquid and thence from the liquid to the surrounding air by means of radiators Water is universally used for the coolant liquid because of its availability and high heat transfer properties. However, water has its limitations. A significant limitation of water as a coolant is its corrosive action causing rust clogging …


Proper Mixtures Of Ellis County Soils For Adobe Construction, And Their Physical Properties, Buster Wayne Read, W. G. Read, H. A. Zinszer Jan 1950

Proper Mixtures Of Ellis County Soils For Adobe Construction, And Their Physical Properties, Buster Wayne Read, W. G. Read, H. A. Zinszer

Fort Hays Studies Series

This paper deals with the adobe strategy of construction which is mixing and puddling the materials to be applied to a sun-dried brick or to a structure of that material. The work was divided into three main parts: (1) Survey of Ellis County Soils; (2) Selection of soil material with respect to shrinkage; and (3) Treatment of soils with respect to waterproofing.


The Mt. Pleasant Story, United States Department Of Agriculture Jan 1950

The Mt. Pleasant Story, United States Department Of Agriculture

Elusive Documents

No abstract provided.


Ecology And Silviculture Of Whitecedar And Associated Hardwoods In Southern New Jersey, Silas Little Jr. Jan 1950

Ecology And Silviculture Of Whitecedar And Associated Hardwoods In Southern New Jersey, Silas Little Jr.

Yale School of the Environment Bulletin Series

No abstract provided.


Relative Productive Value Of Land, Karl Harris, Vaughn E. Hansen Jan 1950

Relative Productive Value Of Land, Karl Harris, Vaughn E. Hansen

Reports

Location, markets, hard surface roads and other transportation facilities, churches, taxes, schools, and utilities are major factors in the monetary value of land, yet these things do not contribute to the land’s productivity. In this bulletin the only factor considered in determining the agricultural value of land is its productive capacity.

The three major factors in the productive value of land are water, climate, and soil.

These three factors are the principal ones in crop production. If any one of them is unfavorable to plant growth, it can inhibit or even prevent plant growth regardless of how favorable the other …


Leaflet No 1003 - The Salt Problem In The Wheat Belt, G. H. Burvill Jan 1950

Leaflet No 1003 - The Salt Problem In The Wheat Belt, G. H. Burvill

Bulletins 1 - 2999

IN the wheat belt of Western Australian bare patches in farm paddocks are often seen. Many are bare, or almost bare, because of too much salt in the soil. The excess of salt prevents the germination of seeds, or kills living plants, because it causes the water supply for germination or growth to be cut off. This salt problem is so serious in places that single farms or groups of farms have been ruined; wheat growing on them has become unprofitable.


The Synthesis And Insecticidal Activity Of Some Halogenated Aromatic Ethers., Tien-Chih Chen Jan 1950

The Synthesis And Insecticidal Activity Of Some Halogenated Aromatic Ethers., Tien-Chih Chen

LSU Historical Dissertations and Theses

No abstract provided.


A Petrographic Study Of The Eocene Jackson Group Of Mississippi And Adjacent Areas., Ming-Shan Sun Jan 1950

A Petrographic Study Of The Eocene Jackson Group Of Mississippi And Adjacent Areas., Ming-Shan Sun

LSU Historical Dissertations and Theses

No abstract provided.


The Conservation Of Systems In Phase Space As Applied To The Liquid State., Ernest Ikenberry Jan 1950

The Conservation Of Systems In Phase Space As Applied To The Liquid State., Ernest Ikenberry

LSU Historical Dissertations and Theses

No abstract provided.


Digestion Studies With Sheep And Wild Antelope On A Sagebrush Ration, Paul Harold Kohler Jan 1950

Digestion Studies With Sheep And Wild Antelope On A Sagebrush Ration, Paul Harold Kohler

Electronic Theses and Dissertations

Introduction: Those who are responsible for the management of antelope, range livestock, and the range seek to maintain such a balance that al may thrive and reproduce. This is inevitably a difficult objective since the balance in numbers of antelope and livestock may be changed annually, but range flora changes only in long-time cycles. Therefore, the balance between the wild and domestic species and the range must be adjusted frequently by range and livestock management. The adjustment of the number of domestic animals to fit the carrying capacity of the range may be accomplished by changing management and marketing practices …


The Application Of High Frequency Oscillations To Chemical Analysis., Thomas Shepherd Burkhalter Jan 1950

The Application Of High Frequency Oscillations To Chemical Analysis., Thomas Shepherd Burkhalter

LSU Historical Dissertations and Theses

No abstract provided.


Studies In The Application Of Extraction Methods To Analytical Chemistry., Jack Kenneth Carlton Jan 1950

Studies In The Application Of Extraction Methods To Analytical Chemistry., Jack Kenneth Carlton

LSU Historical Dissertations and Theses

No abstract provided.


Nebraska Fishing Waters Jan 1950

Nebraska Fishing Waters

Nebraska Game and Parks Commission: Publications

Nebraska waters are inhabited by a wide diversity of fish, including both cold and warm water species. Brown, brook and rainbow trout represent the state's cold water species while the warm variety consists of white bass, large mouth bass, small mouth bass, rock bass, walleye, sauger, northern pike, white crappie, black crappie, perch, channel catfish, blue catfish, yellow catfish, bluegill, freshwater drum, bluegill, sunfish, pumpkin seed and bullhead.

All residents of Nebraska 16 years of age and over must purchase fishing permits to angle in the state. All non-residents, regardless of age, must possess nonresident permits to fish in Nebraska.


Advertising Brochure: Case W-9, Nebraska Tractor Test Lab Jan 1950

Advertising Brochure: Case W-9, Nebraska Tractor Test Lab

Nebraska Tractor Tests

No abstract provided.


Advertising Brochure: Minneapolis-Moline Comfort Tractor, Nebraska Tractor Test Lab Jan 1950

Advertising Brochure: Minneapolis-Moline Comfort Tractor, Nebraska Tractor Test Lab

Nebraska Tractor Tests

No abstract provided.


Test 450: Oliver Row-Crop 88 Diesel, Nebraska Tractor Test Lab Jan 1950

Test 450: Oliver Row-Crop 88 Diesel, Nebraska Tractor Test Lab

Nebraska Tractor Tests

No abstract provided.


Test 441: Mccormick-Deering Wd-9, Nebraska Tractor Test Lab Jan 1950

Test 441: Mccormick-Deering Wd-9, Nebraska Tractor Test Lab

Nebraska Tractor Tests

EXPLANATION OF TEST REPORT:

TEST A: The manufacturer's representative operates the tractor for a minimum of 12 hours using light to heavy drawbar loads in each gear.

This serves as a period for limber up, general observation and adjustments. Adjustments that are permissible include valve tappet clearance, breaker, point gap, spark plug gaps, clutch and others of a similar nature. No new parts or accessories can be installed without having mention made of it in the report. No data' are recorded during this preliminary run except the time that the engine is operated.

BELT HORSEPOWER TESTS

TEST B: The throttle …


The Preparation Of Ammonium Tetrachloro Diiodo Stannate, Stanley M. Polewski Jan 1950

The Preparation Of Ammonium Tetrachloro Diiodo Stannate, Stanley M. Polewski

Bachelors’ Theses

The commercial application of mixed halogen compounds in comparison to that of mono-halogen compounds is very limited. It is probably for this reason that the amount of work done in the attempt to prepare mixed halogen compounds has been very small. The author has tried, in a small way, to help fill this large gap by attempting to prepare the compound, ammonium tetrachloro diiodo stannate.


A Study Of Alcoholysis Using Methyl Esters And Tall Oil, Raymond Martin Frey Jan 1950

A Study Of Alcoholysis Using Methyl Esters And Tall Oil, Raymond Martin Frey

Bachelors’ Theses

One of the Easiest ways of preparing new esters is by heating an ester with another alcohol which frequently permits transfer of the acid radical from the original ester to the added alcohol, thous forming a new ester and liberating the other alcohol. Preparation of triglycerides of unsaturated fatty acids of 18 carbon atoms is hampered by the fact that prolonged heating in the usual ester formation methods causes both polymerization and condensation among acid radicals unless oxygen is carefully excluded from the reaction atmosphere. Consequently a method of acid interchange might afford the triglycerides at a faster rate and …


Further Studies Of The Reactions Of Quinoxaline, 2-Methyl-, And 2,3-Dimethylquinoxaline, Chester E. Hamilton Jan 1950

Further Studies Of The Reactions Of Quinoxaline, 2-Methyl-, And 2,3-Dimethylquinoxaline, Chester E. Hamilton

Theses and Dissertations

A long term research program into the chemistry of quinoxalines has been instituted at Brigham Young University. The literature of quinoxaline chemistry was reviewed and assembled in one paper. Methods of preparation of 2,3-dimethyl- and 2- methylquinoxaline were studied and improved. The bromination of 2,3-dimethylquinoxaline using N-bromosuccinimide was accomplished and an anil addition using quinoxaline and phenyllithium was achieved. Efforts to prepare vinylquinoxalines were unsuccessful. In order to pursue an investigation into the numerous reactions of the 1,4 addition type, a method of preparations of vinyl-quinoxalines must be achieved. In the present investigation, various methods of synthesis of vinyl- and …


Certain Coloring Matters Derived From Vanallin And Methyl Salicylate, Thompson James Coe Jan 1950

Certain Coloring Matters Derived From Vanallin And Methyl Salicylate, Thompson James Coe

University of the Pacific Theses and Dissertations

The purpose of this investigation was to prepare a number of coloring matters by condensing vanillin with para-methoxyacetophenone, meta-nitroacetophenone, and para-bromoacetophenone, and to prepare another group by condensing methyl salicylate with acetophenone, para-methoxyacetophenone, meta-nitroacetophenone, and ortho-hydroxyacetophenone. Ethyl salicylate and para-methoxyacetophenone were condensed as a check.


Preliminary Report Of Occurrence And Properties Of Nepheline Syenite In Pulaski County, Arkansas, Harold B. Foxhall, William E. Crockett Jan 1950

Preliminary Report Of Occurrence And Properties Of Nepheline Syenite In Pulaski County, Arkansas, Harold B. Foxhall, William E. Crockett

Journal of the Arkansas Academy of Science

No abstract provided.


Advertising Brochure: Allis-Chalmers , Nebraska Tractor Test Lab Jan 1950

Advertising Brochure: Allis-Chalmers , Nebraska Tractor Test Lab

Nebraska Tractor Tests

No abstract provided.


An Ecological Study Of The Foraminifera Of Mason Inlet, North Carolina, Daniel N. Miller Jr. Jan 1950

An Ecological Study Of The Foraminifera Of Mason Inlet, North Carolina, Daniel N. Miller Jr.

Masters Theses

"Mason Inlet. North Carolina is a lagoonal marsh area with warm-temperate water, the salinity ranging from fresh to salt water. Nine collecting stations comprise an ecological gradient across the environment.

Forty-two species of foraminifera are recorded from the inlet, ranging in their affinities from brackish water to open-sea facies. Several extensions of range are recorded both northward and southward.

Substratum conditions apparently control the distribution of foraminifera within the inlet. Clean, fine sand provided the largest faunal populations. A depauperate assemblage was found in an inorganic, argillaceous substratum. The largest population of arenaceous forms was found at the channel through …


Selected Studies Of Organic Reagents., Louis Johnson Conrad Jan 1950

Selected Studies Of Organic Reagents., Louis Johnson Conrad

LSU Historical Dissertations and Theses

No abstract provided.


Some Physical And Chemical Properties Of Loess Deposits In The Lower Mississippi Valley., Ellis Louis Krinitzsky Jan 1950

Some Physical And Chemical Properties Of Loess Deposits In The Lower Mississippi Valley., Ellis Louis Krinitzsky

LSU Historical Dissertations and Theses

This study presents a general picture of loess in the Lower Mississippi Valley. Loess is recognized as unstratified, calcareous, slightly plastic, porous loam with an average grain size distribution between 0.05 and 0.01mm. diameter. Materials meeting this definition but lacking in calcium carbonate are termed "leached loess" when in association with loess and "brown loam" when not in association with loess.

Loess has been found to occur chiefly as pseudo-anticlinal caps on hills. It is mapped as occurring within an area averaging 10 to 15 miles in width extending from southern Illinois southward along the eastern walls of the Lower …


Quaternary Geology Of Southeast Texas., Hugh Allen Bernard Jan 1950

Quaternary Geology Of Southeast Texas., Hugh Allen Bernard

LSU Historical Dissertations and Theses

No abstract provided.


An Index To The Literature On Digenetic Trematodes From Fishes, Richard William Bond Jan 1950

An Index To The Literature On Digenetic Trematodes From Fishes, Richard William Bond

University of the Pacific Theses and Dissertations

The primary purpose of this compilation is to facilitate for pertinent literature in the searches involving digenetic trematodes from fines. The index may be used by the investigator to determine what, Af any, 14torature has appeared concerning the animal or group of animals with which he is working; and the literature is cross-indexed in such a way that it may be approached from the various angles commonly used in trematodes investigations. There are included, for example, an index to hosts, an index to larval stages of development and a partial geographic index to adult trematodes of fishes.