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Articles 292411 - 292440 of 302449

Full-Text Articles in Physical Sciences and Mathematics

Evaluation Of The Filter Paper Method For Estimating Soil Water Potential, Samir Al-Khafaf May 1972

Evaluation Of The Filter Paper Method For Estimating Soil Water Potential, Samir Al-Khafaf

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The filter paper method for measuring soil water potential was evaluated. The method was calibrated using salt solutions (-1.4 bars to -22.4 bars), sample chamber psychrometer (-1 to -50 bars), pressure plate (-0.1 to -15 bars) and soil column at equilibrium (0 to -0.2 bars). It was found that the absolute temperature had little effect on the predicted soil water potential, but a temperature variation had a large effect. It was found that the temperature fluctuation must be small. The predicted water potential was influenced by the type of contact of the soil with the filter paper. It is suggested …


Effect Of Bear River Storage On Water Quality In Bear Lake, Utah-Idaho, Robert L. Nunan May 1972

Effect Of Bear River Storage On Water Quality In Bear Lake, Utah-Idaho, Robert L. Nunan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Since 1912 concentrations of the major anions and cations (except calcium) in Bear Lake water have shown a steady decrease which has been attributed to a dilution of Bear Lake by Bear River water, Bear Lake having been used as a reservoir for Bear River water since 1918. This study examined the changes which have occurred in Bear Lake water chemistry since 1912 and tested the validity of the dilution theory.

Simple water and salinity budgets were determined for the Bear Lake system and used to simulate the effect of Bear River storage patterns since 1918 on the concentrations of …


Role Of Iron And Electrical Conductivity In Iron Calcium Phosphate Glasses, Rafik Farid Shaker May 1972

Role Of Iron And Electrical Conductivity In Iron Calcium Phosphate Glasses, Rafik Farid Shaker

Archived Theses and Dissertations

No abstract provided.


Model For Estimating Soil Water Flow, Water Content, Evapotranspiration And Root Extraction, Musa N. Nimah May 1972

Model For Estimating Soil Water Flow, Water Content, Evapotranspiration And Root Extraction, Musa N. Nimah

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A mathematical model was developed to predict water content profiles, evapotranspiration, water flow from or to the water table, root extraction and root water potential at the surface as functions of time under unsteady state conditions.

The model was tested in the field at The Hullinger Farm near Vernal, Utah, in 1970 and 1971. Comparison of water content-depth profiles show excellent agreement at the end of a 9- day run in 1970 on oats seeded to alfalfa. In 1971 with alfalfa as the crop, the data show best agreement, between predicted and computed water content-depth profiles, 48 hours after any …


Selecting The Best Linear Model From A Subset Of All Possible Models For A Given Set Of Predictors In A Multiple Linear Regression Analysis, David L. Jensen May 1972

Selecting The Best Linear Model From A Subset Of All Possible Models For A Given Set Of Predictors In A Multiple Linear Regression Analysis, David L. Jensen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Sixteen "model building" and "model selection" procedures commonly encountered in industry, all of which were initially alleged to be capable of identifying the best model from the collection of 2k possible linear models corresponding to a given set of k predictors in a multiple linear regression analysis, were individually summarized and subsequently evaluated by considering their comparative advantages and limitations from both a theoretical and a practical standpoint. It was found that none of the proposed procedures were absolutely infallible and that several were actually unsuitable. However, it was also found that most of these techniques could still be …


A Two Sample Test Of The Reliability Performance Of Equipment Components, Miki Lynne Coleman May 1972

A Two Sample Test Of The Reliability Performance Of Equipment Components, Miki Lynne Coleman

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this study was to develop a test which can be used to compare the reliability performances of two types of equipment components to determine whether or not the new component satisfies a given feasibility criterion.

Two types of tests were presented and compared: the fixed sample size test and the truncated sequential probability ratio test. Both of these tests involve use of a statistic which is approximately distributed as F.

This study showed that the truncated sequential probability ratio test has good potential as a means of comparing two component types to see whether or not the …


Sequential Analysis For Tolerances Of Noxious Weed Seeds, Seung Tokko May 1972

Sequential Analysis For Tolerances Of Noxious Weed Seeds, Seung Tokko

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The application of a sequential test, the sequential probability ratio test, for the tolerances of noxious weed seeds is studied. It is proved that the sequential test can give a similar power curve to that of the current fixed sample test if the test parameters are properly chosen.

The average sample size required by a sequential test, in general, is smaller than that of the existing test. However, in some cases it requires relatively a larger sample than current test.

As a solution to the problem a method of truncation is considered. A kind of mixed procedure is suggested. This …


An Examination Of The Inorganic Nitrogen Status Of A Soil Of The Alaskan Coastal Tundra Plain, Norton R. Munn May 1972

An Examination Of The Inorganic Nitrogen Status Of A Soil Of The Alaskan Coastal Tundra Plain, Norton R. Munn

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This experiment was designed to measure in situ concentrations of NH4+ and NO3--N in a soil of the arctic coastal tundra plain, to determine if nitrification was taking place in this soil and to determine if the vascular plants growing in this soil could assimilate NH4+-N.

The extractable NH4+-N concentration was approximately 40 μg/g in the 01 horizon and 10 μg/g in the 02 horizon. The NO3--N concentration was approximately 5 μg/g in the 01 horizon and 4 μg/g in the 02 …


Potentiometric Titration Of Sulfate Using A Lead-Mercury Amalgam Indicator Electrode, Charles W. Robbins May 1972

Potentiometric Titration Of Sulfate Using A Lead-Mercury Amalgam Indicator Electrode, Charles W. Robbins

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A lead sensitive indicator electrode was constructed with a 70 percent lead and 30 percent mercury amalgam billet. Sulfate concentrations in pure solutions, natural waters, and soil saturation extracts were determined potentiometrically using the lead-mercury amalgam indicator electrode and a standard calomel reference electrode. Sulfate concentrations over the range 0.4 to 20 milliequivalents sulfate per liter were determined with an automatic titrator and compared to a turbidimetric method for accuracy and precision. The values obtained by the two methods from twelve saturation extracts and three subsurface drainage waters were not significantly different and the potentiometric method was generally more precise. …


Tertiary Igneous Rocks Of Northeastern Cache Valley, Idaho, Parry D. Willard May 1972

Tertiary Igneous Rocks Of Northeastern Cache Valley, Idaho, Parry D. Willard

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The tuffs and limestones of the Tertiary Salt Lake Formation in northeastern Cache Valley, Franklin County, Idaho, are intruded by basic and intermediate igneous dikes and sills. The Tertiary intrusives are exposed in an area 10 miles long and 2 miles wide between Bear River and Maple Creek in the foothills of the Bear River Range east of Preston, Idaho. They trend north-northwest. The intrusives are mostly diabase but include a small body of syenodiorite and several small andesite dikes. The intrusives seem to be emplaced along early Basin and Range faults. They are limited to the Cache Valley Member …


Geology Of The Wildcat Hills, Utah, Ronald C. Howes May 1972

Geology Of The Wildcat Hills, Utah, Ronald C. Howes

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Wildcat Hills, located in Curlew Valley of northwestern Utah, are composed of a series of late Tertiary extrusive and dike rocks. Five volcanic rock types have been identified: an andesite, a rhyolite, a perlite, a basalt, and a welded tuff. Hydration of obsidian pellets contained in the flows has produced some of the perlite. Diatremes in the andesite attest to the high-volatile content and the explosive extrusion of some of the lavas. A compound basalt neck indicates that basalt was extruded at the Wildcat Hills and is not an erosional remnant of the basalt flow from the base of …


Model For Predicting Simultaneous Distribution Of Salt And Water In Soils, Satish C. Gupta May 1972

Model For Predicting Simultaneous Distribution Of Salt And Water In Soils, Satish C. Gupta

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Knowledge of water and salt movement in soils is necessary for development of a management scheme for controlling the quality of irrigation return flow. A computer model was developed to predict the distribution of water and salts in the root zone under varying initial and boundary conditions. The model consists of water flow and salt flow sub-models. The water flow sub-model considers the numerical approximation of the general water flow equation with modification for water loss by evapotranspiration (and thus root extraction). The salt flow sub-model considers the mass flow of salts, chemical exchange, precipitation or dissolution of CaCO3 …


An Analysis Of Stock Densities And Harvest Of The Cutthroat Trout Of The Snake River, Teton County, Wyoming, John W. Kiefling May 1972

An Analysis Of Stock Densities And Harvest Of The Cutthroat Trout Of The Snake River, Teton County, Wyoming, John W. Kiefling

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

An intensive creel census and marking program was conducted in 1969 and 1970 to make possible population estimates and estimates of harvest of cutthroat trout in the Snake River in Teton County, Wyoming. Stock density determinations made in one of the five study areas provided an estimate of 400 and 992 cutthroat trout, eight inches or more in length, per mile of stream in 1969 and 1970 respectively.

Harvest data provide an estimate of 5,207 and 5,903 cutthroat trout harvested in 1969 and 1970 respectively. The harvest estimates obtained in this study are not comparable to those made in 1967 …


Stratigraphy And Environmental Analysis Of The Swan Peak Formation And Eureka Quartzite, Northern Utah, George Gregory Francis May 1972

Stratigraphy And Environmental Analysis Of The Swan Peak Formation And Eureka Quartzite, Northern Utah, George Gregory Francis

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Swan Peak Formation in north-central Utah thickens westward, from zero feet near Logan to 687 feet in the Promontory Range. The unit is subdivided into three distinct members: 1) A lower member of interbedded shales, limestones, and quartzites; 2) A middle member of interbedded shales and brown quartzites; and 3) An upper member of white quartzites. The Swan Peak thins southward toward the east-west-trending Tooele Arch in the area of study; this thinning probably reflects both lesser deposition and greater subsequent erosion there than elsewhere. The lower member in northern Utah probably was deposited in shallow-shelf and/or traditional shoreface-shelf …


Selected Factors Related To Ability To Regain Bladder Function Following Indwelling Catheterization, Jongkolnee Padmasiri May 1972

Selected Factors Related To Ability To Regain Bladder Function Following Indwelling Catheterization, Jongkolnee Padmasiri

Loma Linda University Electronic Theses, Dissertations & Projects

This exploratory retrospective study was designed to evaluate selected factors, including the ability to regain bladder function related to post indwelling urethral catheterization in an acute general hospital population.

The records of 107 patients who met the study criteria became the study population. These patients had three-way urethral catheters, continuous antibacterial irrigation and closed drainage system. Twenty patients died (19 percent) before the catheter was removed. Of the 87 patients who were alive, 37 percent (32 patients) had in-adequate bladder function. Of these 32 patients, no attempt was made to remove the catheter from 15 prior to their hospital discharge. …


Groundwater Levels In Nebraska, 1971, C.F. Keech May 1972

Groundwater Levels In Nebraska, 1971, C.F. Keech

Conservation and Survey Division

No abstract provided.


Use Of Groundwater For Irrigation In Clay County, Nebraska, 1970, Eugene K. Steele Jr. May 1972

Use Of Groundwater For Irrigation In Clay County, Nebraska, 1970, Eugene K. Steele Jr.

Conservation and Survey Division

No abstract provided.


Two Emotional Factors And Weight Loss Among Females Attending A Weight Control Class, Karen Lynn Carrigg, Eileen Rae Wangerin May 1972

Two Emotional Factors And Weight Loss Among Females Attending A Weight Control Class, Karen Lynn Carrigg, Eileen Rae Wangerin

Loma Linda University Electronic Theses, Dissertations & Projects

A descriptive study was conducted on twenty-four females attending a weight control class to discover the effect of weight loss upon levels of self-esteem and anxiety, as an understanding of the relation of these factors to reduction and control of weight would prove helpful to community health nurses in counseling with overweight and obese persons in the community.

The entire sample was tested for self-esteem (TSCS) and A-State and A-Trait anxiety levels at the initial class of the weight control program sponsored by the Health Education Department of Loma Linda University Medical Center, and again after seven weeks of class …


Assisting Mothers To Successfully Breast Feed Their Babies, Annabelle Moore May 1972

Assisting Mothers To Successfully Breast Feed Their Babies, Annabelle Moore

Loma Linda University Electronic Theses, Dissertations & Projects

This experimental study tested the effect of a teaching program on success of a group of mothers desiring to breast feed their babies. It was hypothesized that mothers receiving specific instructions on the physiology of lactation and the proper sucking technique would have greater success than mothers not so instructed.

To be categorized as successful the mothers had to have an adequate supply of milk and had to express satisfaction with breast feeding. Criteria for adequacy of milk supply consisted of weight gain of the infant within accepted norms without use of supplementary formula.

Twenty breast feeding mothers who delivered …


A Clinical Comparison Of Six Orthodontic Techniques, Erik H. Madsen May 1972

A Clinical Comparison Of Six Orthodontic Techniques, Erik H. Madsen

Loma Linda University Electronic Theses, Dissertations & Projects

Controversy exists concerning the relative superiority of various orthodontic techniques because of the difficulties encountered in making comparative clinical studies of these techniques which are scientific and statistically meaningful. The purpose of this study was to clinically compare six different orthodontic techniques which are currently being taught, relative to a number of criteria, and to do it in a scientifically significant manner.

In order to eliminate as many of the irrelevant variables as possible, the patients were required to pass a relatively stringent screening to participate. Among other things, the patients had to have first molars in Class I relation …


A New Method For The Preparation Of Alkylnaphthyl Ethers And Sulfides, Edward Ying-Shih Chen May 1972

A New Method For The Preparation Of Alkylnaphthyl Ethers And Sulfides, Edward Ying-Shih Chen

Theses and Dissertations

The reaction of monohalonaphthalenes with metal alkoxides and mercaptides in a solvent mixture of the corresponding alcohol and dimethyl sulfoxide (DMSO) has been studied. These reactions are convenient methods for the preparation of alkylnaphthyl ethers and sulfides. Only direct nucleophilic substitution was observed in the reactions of bromonaphthalenes with sodium methoxide and sodium nbutyl mercaptide. The reaction of fluoronaphthalene with potassium t-butoxide also proceeded by way of direct nucleophilic substitution rather than the 1,2-dehydronaphthalene intermediate as in the reactions of bromonaphthalene with potassium t-butoxide. The use of a base which is weaker than t-butoxide can change the apparent reaction mechanism …


Electrolytic Synthesis Of [Gamma]-Diketones, Leon F. Pahler May 1972

Electrolytic Synthesis Of [Gamma]-Diketones, Leon F. Pahler

Theses and Dissertations

Four γ-diketones were synthesized by using a modification of the Kolbe electrolytic condensation of β-ketocarboxylic acids. [--see equation in thesis--] The following γ-diketones were synthesized in moderate yields: 2,5-hexanedione, 4,7-decanedione, 2,2,7,7-tetramethyl- 3,6-octanedione, and 1,4-diphenyl-1,4-butanedione (34, 39, 23, and 27, respectively). However, attempted preparation of the following γ-diketones failed: 3,4-dimethyl- 2,5-hexanedione, 3,3,4,4-tetramethyl-2,5-hexanedione, and 1,4-di(2-thienyl)-1,4-butanedione. Attempts to electrolytically condense α-alkyl and α, α-dialkyl substituted monocarboxylic acids have been reported and all attempts have ended in failure; similarly, the attempts to synthesize 3,4-dimethyl and 3,3,4,4-tetramethyl- 2,5-hexanedione from 2-methyl and 2,2-dimethyl-3- oxobutanoic acid, respectively, failed. The preparation of 1,4-di(2-thienyl)-l,4-butanedione failed because the product or …


Rhenium Catalyzed Hydrogenation Of Maleic Anhydride And Crotonaldehyde, William Russel Dixon May 1972

Rhenium Catalyzed Hydrogenation Of Maleic Anhydride And Crotonaldehyde, William Russel Dixon

Theses and Dissertations

The preparation of a number of supported rhenium catalysts is reported. The determination of their activity and selectivity and of optimal reaction parameters for the reduction of maleic anhydride and crotonaldehyde is reported. Optimal time of hydrogenation was chosen as one hour and pressures were chosen as 2000 psig for crotonaldehyde and 3000 psig for maleic anhydride. Quantitative reduction of maleic anhydride to tetrahydrofuran occurred at 275° with charcoal supported rhenium catalysts. Lower temperatures (ca. 200°) produce quantitative amounts of butyrolactone. Unsupported catalysts at low temperatures (100°) selectively reduce crotonaldehyde to crotyl alcohol, but at very low conversion rates. Temperatures …


Toward Hydrogen Bonds Of Predictable Geometry, Robert Shao-Chih Hsu May 1972

Toward Hydrogen Bonds Of Predictable Geometry, Robert Shao-Chih Hsu

Theses and Dissertations

A literature review on the geometry of hydrogen bonding showed that the geometry is often de-emphasized or even ignored, probably because of the inherent flexibility of many systems studied. Examination of molecular models suggested the geometrically constrained bicyclo [2, 2, 1] heptane system wherein hydrogen bond distances and angles might be more easily predicted. Dihydroboration-oxidation of norbornadiene was shown to yield exo, exo-2,5-norbornadiol, thus clarifying uncertainties in the literature. 2, 5-Norbornadiol was oxidized to the corresponding dione, heretofore inadequately characterized. Several derivatives of the dione were prepared, and spectral data were accumulated for the dione, its precursor, and its derivatives. …


Acid-Base Titrations In Sulfolane., Francine O. Lawrence Apr 1972

Acid-Base Titrations In Sulfolane., Francine O. Lawrence

Chemistry and Chemical Biology ETDs

A study of the solvent effects of sulfolane (tetrahydrothiophene 1,1-dioxide, tetramethylene sulfone) upon a series of acids and several bases has been conducted. A procedure is presented for purifying sulfolane which results in a solvent of very low water content (5 x 10^-4 M ) and very few impurities, as shown by its cooling curve. Potentiometric and conductometric measurements of additions of acids and bases to purified sulfolane and of various acid-base titrations were made. The series of carboxylic acids included benzoic, orthomethoxybenzoic, and three different monochlorobenzoic acids. The bases investigated included sodium methoxide, pyridine, and diphenylguanidine. Interpretation of the …


84th Session Of The Iowa Academy Of Science, April 28-29, 1972, Iowa Academy Of Science Apr 1972

84th Session Of The Iowa Academy Of Science, April 28-29, 1972, Iowa Academy Of Science

Iowa Academy of Science Documents

No abstract provided.


Abstracts Of Papers Presented At The 84th Session Of The Iowa Academy Of Science, April 28-29, 1972, Iowa Academy Of Science Apr 1972

Abstracts Of Papers Presented At The 84th Session Of The Iowa Academy Of Science, April 28-29, 1972, Iowa Academy Of Science

Iowa Academy of Science Documents

Presentation abstracts from the annual meeting of the Iowa Academy of Science


19f Nmr And Bx3 Complexes, Nancy Toole Tucker Apr 1972

19f Nmr And Bx3 Complexes, Nancy Toole Tucker

Morehead State Theses and Dissertations

A thesis presented to the faculty of the School of Sciences and Mathematics at Morehead State University in partial fulfillment of the requirements for the Degree of Master of Science in Chemistry by Nancy Toole Tucker on April 21, 1972.


Preparation And Reactions Of 2-Benzo [B] Thienylsodium, Larry Kennard Apr 1972

Preparation And Reactions Of 2-Benzo [B] Thienylsodium, Larry Kennard

Morehead State Theses and Dissertations

A thesis presented to the faculty of the School of Science and Mathematics at Morehead State University in partial fulfillment of the requirements for the Degree of Master of Science in Chemistry by Larry Kennard on April 21, 1972.


Influence Of An External Electric Field On The Charge Transfer State Of The Tcne-Trans-Stilbene Molecular Complex, Craig J. Eckhardt Apr 1972

Influence Of An External Electric Field On The Charge Transfer State Of The Tcne-Trans-Stilbene Molecular Complex, Craig J. Eckhardt

Craig J. Eckhardt Publications

An experimental investigation of the effect of an external electric field on the absorption spectrum of the tetracyanoethylene-trans-stilbene molecular complex in cyclohexane solution yielded values of 1.1±0.1 D for the ground state electric dipole moment and 10.5±0.9 D for the change of the electric dipole moment upon transition to the charge transfer excited state. The ground state electric dipole moment determined by the electro-optic effect is in agreement with the value of 1.4±0.5 D obtained from the dielectric constant measurements made on solutions of the complex. The directions of the transition moment, the ground state electric dipole moment, and the …