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Pleistocene Histroy Of Mississippi River (Abstract), A. C. Trowbridge, A. J. Williams, J. C. Frye, F. A. Swenson
Pleistocene Histroy Of Mississippi River (Abstract), A. C. Trowbridge, A. J. Williams, J. C. Frye, F. A. Swenson
Proceedings of the Iowa Academy of Science
From its earliest known record immediately prior to the advance of the Nebraskan glacier to the present time the course of Mississippi River was affected by each advancing ice sheet in turn. The Nebraskan glacier displaced it to the east, the Kansan glacier shoved it farther east, the Illinoian glacier pushed it back west, with the retreat of the Illinoian ice it took an easterly course again, the Iowan or earliest Wisconsin glacier diverted it from one minor channel to another, the Green River lobe of the Tazewell Wisconsin ice sheet forced it back into a western course and started …
The Problem Of Night Driving In Relation To Accident Prevention (Abstract), A. R. Lauer
The Problem Of Night Driving In Relation To Accident Prevention (Abstract), A. R. Lauer
Proceedings of the Iowa Academy of Science
Records have shown that nearly 3,089 grade crossing accidents occurred in the United States in 1938. Of this number 1,450 occurred at night. Equating for volume of traffic and miles of travel, about 65 per cent of train-automobile accidents occur at night. Additional data indicate that the chances of a car driving into a train at night are about 9 times greater than in daylight. Of the estimated $3,000,000,000 annual economic loss to the country through automobile accidents it is shown that night driving costs about $1,200,000,000, although only 25 per cent of the driving is done during this period …
Changes In Susceptibility To X-Rays Of Certain Embryonic Cells Of The Grasshopper (Abstract), J. C. Slaughter, T. C. Evans, J. P. Goodrich
Changes In Susceptibility To X-Rays Of Certain Embryonic Cells Of The Grasshopper (Abstract), J. C. Slaughter, T. C. Evans, J. P. Goodrich
Proceedings of the Iowa Academy of Science
Eggs of Melanoplus differentialis were irradiated with dosages of 1,000-10,000 roentgens, in steps of 1,000 on each of the first six days after laying. Gross and microscopical studies of the eggs were made after the controls had reached diapause. It was found that the radiation on the first and second days had prevented subsequent development of all cells. Irradiation after the second day inhibited the development only of the cells of the embryo proper. It is therefore indicated that the yolk and serosa cells undergo 1:1 marked increase in their resistance to X-rays after the second day. The yolk and …
Simplified Blood Cholesterol Method, T. U. Marron
Simplified Blood Cholesterol Method, T. U. Marron
Proceedings of the Iowa Academy of Science
In the treatment of diabetics it is desirable to use the blood cholesterol value as an indication of effectiveness of the control measures. The diabetic individual is usually accustomed to the finger prick for obtaining blood for sugar determinations; so a method using capillary blood has been devised for cholesterol determination.
Effects Of Hydrogen Ion Concentration Upon The Hydrolysis Rates Of Ketimines (Abstract), I. Johnson, J. B. Culbertson
Effects Of Hydrogen Ion Concentration Upon The Hydrolysis Rates Of Ketimines (Abstract), I. Johnson, J. B. Culbertson
Proceedings of the Iowa Academy of Science
Measurements have been made upon the hydrolysis rates of ketimine hydrochlorides to obtain information concerning the relation between their varied structures and stability toward hydrolysis1. The hydrogen ion concentration might appear as a catalytic factor in this hydrolysis2. It would thus seem necessary to determine these hydrolysis rates at the same hydrogen ion concentration if this factor has a marked effect. Different ketimine hydrochlorides alone in water produce, in the dilute solutions usually employed, pH values ranging initially from about a.6 to 5.3 and increasing in each case toward the pH of the equivalent ammonium chloride …
An Attempt To Determine Beryllium In The Presence Of Aluminum Conductometrically (Abstract), Robert Torley, Louis Waldbauer
An Attempt To Determine Beryllium In The Presence Of Aluminum Conductometrically (Abstract), Robert Torley, Louis Waldbauer
Proceedings of the Iowa Academy of Science
A study was made of the possibility of a stable, soluble complex of beryllium serving as a means of its conductometric titration in the presence of aluminum. It was found that beryllium formed soluble, slightly dissociated compounds with both the oxalate and the malonate ions, the mole ratio of the beryllium to oxalate and to malonate being in each case 1:1. Complexes were formed with the tartrate and the hexametaphosphate ions. Only in the case of the formation of the beryllium oxalate compound was the break in the conductivity curve sharp enough for quantitative measurements. Aluminum was not found to …
Rigidity Modulus Of Lead Single Crystals (Abstract), Irvin H. Swift
Rigidity Modulus Of Lead Single Crystals (Abstract), Irvin H. Swift
Proceedings of the Iowa Academy of Science
The isothermal rigidity modulus has been measured for lead crystals of various orientations. The reciprocal bending-torsion effect and its influence on the measurement are considered.
Some Relationships Between Placement Scores And Scholastic Rating, Paul C. Greene
Some Relationships Between Placement Scores And Scholastic Rating, Paul C. Greene
Proceedings of the Iowa Academy of Science
This paper reports obtained correlations between scores on entrance tests, and between entrance scores and scholastic rating during the first semester of college work, for students entering Coe College in September, 1940.
Survey Of Harmony Courses In American Colleges And Universities, Frank W. Hill
Survey Of Harmony Courses In American Colleges And Universities, Frank W. Hill
History of Education Book Gallery
No abstract provided.
Mechanism Of The Formation Of Tetraphenyl-Lead From Lead Chloride And Phenyllithium, Ernest Bindschadler, Henry Gilman
Mechanism Of The Formation Of Tetraphenyl-Lead From Lead Chloride And Phenyllithium, Ernest Bindschadler, Henry Gilman
Proceedings of the Iowa Academy of Science
The present study is concerned with the formation of tetraphenyllead from lead chloride and phenyllithium. It is probable that the closely related phenyllithium and phenylmagnesium bromide react with lead chloride by closely related mechanisms. By using, at this time, phenyllithium in place of phenylmagnesium bromide, we were able to avoid possible secondary reactions involving magnesious bromide and magnesium bromide.
Vapor-Pressure Lowering Of Sulfur Dioxide Solutions Of Potassium Thiocyanate From 15 To 25 C. (Abstract), W. G. Eversole, G. H. Wagner
Vapor-Pressure Lowering Of Sulfur Dioxide Solutions Of Potassium Thiocyanate From 15 To 25 C. (Abstract), W. G. Eversole, G. H. Wagner
Proceedings of the Iowa Academy of Science
The vapor-pressure lowering of sulfur dioxide by potassium thiocyanate at 15°, 20° and 25° C. was measured by means of a differential mercury manometer connected to an all glass apparatus which employed no stopcocks. Readings were made to 0.001 cm. with a cathetometer. All concentrations were corrected for the amount of sulfur dioxide in the vapor phase. The molal lowering was approximately one-half the theoretical value at 0.005 molal and decreased with increasing concentration up to 1 molal, the highest concentration studied.
Copper Content In Various Water Supplies Due To Copper Plumbing (Abstracts), R. Rupert Kountz, C. H. Buurman
Copper Content In Various Water Supplies Due To Copper Plumbing (Abstracts), R. Rupert Kountz, C. H. Buurman
Proceedings of the Iowa Academy of Science
The survey covers different types of waters, including treated and untreated well and surface supplies, and softened water (private and municipal). In each case the copper values are correlated with the age of the plumbing and the analysis of the water. The copper was determined by the modified diethyldithio-carbamate method. Although amounts of copper such as were found are toxic to many kinds of fish, they are not harmful for human consumption.
The Occurrence Of Plant Microfossils In The Pennsylavanian Coals Of The United States (Abstract), L. R. Wilson
The Occurrence Of Plant Microfossils In The Pennsylavanian Coals Of The United States (Abstract), L. R. Wilson
Proceedings of the Iowa Academy of Science
By maceration of coal it is possible to extract microfossils that consist of various plant parts. These are briefly described and shown to have stratigraphic value.
Crinoids Varied In Color At Le Grand, Iowa (Abstract), B. H. Beane
Crinoids Varied In Color At Le Grand, Iowa (Abstract), B. H. Beane
Proceedings of the Iowa Academy of Science
In the Le Grand quarries there is an unusual occurrence of multicolored crinoids. Some of these crinoids are almost black, some are almost white, some are dark brown, some are light brown and some are cream colored. Each species is found always to have the same color. One familiar with the fossils can classify them accurately by the color. Platycrinus symmetricus is a dark brown. Diochrinus inornatus is a chocolate brown and Rhodocrinus kirbyi is almost black. Most of the inadunate species are white. One species with unusual coloring is Rhodocrinus watersianus with a mottled brown calyx and light colored …
Angular Distribution Of Gamma Rays From Flourine Bombarded With Protons (Abstract), Stanley Atchison
Angular Distribution Of Gamma Rays From Flourine Bombarded With Protons (Abstract), Stanley Atchison
Proceedings of the Iowa Academy of Science
No abstract provided.
A New Proof Of A Formula Of Kuratowski, E. W. Chittenden
A New Proof Of A Formula Of Kuratowski, E. W. Chittenden
Proceedings of the Iowa Academy of Science
Given a topological space in which the operation of closure of a set, here denoted by 'e', has the properties: e (A+B) = eA+eB; A is a subset of eA, eO = 0, e2A = eA (where A is any subset of the space and 0 is the null set), we may define the interior 'i' of a set A by the formula iA = cecA (where cA denotes the complement of A in the space) and write a formula entirely equivalent to one due to C. Kuratowski (Fundamenta Mathematicae, III (1922), p. 183) in the following way: …
High Intensity Flash Tube (Abstract), T. Robert Burnight
High Intensity Flash Tube (Abstract), T. Robert Burnight
Proceedings of the Iowa Academy of Science
The design and construction of a high energy gaseous flash tube and appertaining equipment for high speed single exposure photography is described. Flash characteristics are estimated and performance criteria are proposed. Comparative experimental results are given and improvements in design are discussed.
The Elements Of Surface Tension (Abstract), John A. Eldridge
The Elements Of Surface Tension (Abstract), John A. Eldridge
Proceedings of the Iowa Academy of Science
Many of our ordinary statements about surface tension are true only when properly qualified. Common laboratory experiments give correct values only when correction terms are used. A number of surface tension paradoxes will be given.
Rigidity Modulus For Beta-Brass Single Crystals (Abstract), Walter A. Good
Rigidity Modulus For Beta-Brass Single Crystals (Abstract), Walter A. Good
Proceedings of the Iowa Academy of Science
The change due to "disordering" in beta-brass is being followed for the dynamically determined rigidity modulus of crystals of beta-brass. By combining this work with that of Rinehart a full set of elastic parameters for beta-brass is obtained.
Interesting Case Where The Heat Flow Increases The Heat Conductivity Of A Fluid (Abstract), Sulamith Bereskin, G. W. Stewart
Interesting Case Where The Heat Flow Increases The Heat Conductivity Of A Fluid (Abstract), Sulamith Bereskin, G. W. Stewart
Proceedings of the Iowa Academy of Science
If the molecules in liquid crystalline para-azoxyanisol are oriented by a magnetic field, the coefficient of heat conduction is thereby increased by (roughly) twenty-five per cent. The orientation of the molecules produces also orientation of the swarms, often called liquid crystals. Using the results of this experiment in conjunction with earlier experiments in which the flow of heat has also an orienting effect, one can state that the flow of heat decreases the coefficient of heat conduction.
Resonance In B11 + H1 (Abstract), James Jacobs, W. B. Mclean
Resonance In B11 + H1 (Abstract), James Jacobs, W. B. Mclean
Proceedings of the Iowa Academy of Science
Yield-energy curves for the reaction B11 + H1, using a gas target, have been obtained with an ionization chamber set to count all alpha particles of range greater than 2.0 cm., 2.5 cm., 3.0 cm. and 3.5 cm. The difference curves indicate that alpha particles of all ranges show resonance at 158 + 3 Kev. The energy of the bombarding protons was obtained by using the 330 Kev resonance in the yield of gamma rays from the reaction F19 + H1 as a standard. The apparent half-width for both the fluorine and boron reactions is …
Scattering Of Na Ions In Hg Vapor (Abstract), F. W. Parker
Scattering Of Na Ions In Hg Vapor (Abstract), F. W. Parker
Proceedings of the Iowa Academy of Science
The angular distribution of Na ions scattered by Hg vapor has been investigated by means of a rotating collecting assembly. Ionization effects appear for ion energies greater than 100 e-volts.
Physics Concepts In Grade School Science (Abstract), C. J. Lapp
Physics Concepts In Grade School Science (Abstract), C. J. Lapp
Proceedings of the Iowa Academy of Science
The physics concepts in grade school science have been determined by examining some thirty grade school science readers. These have been classified by grades.
Scattering Of Potassium Ions In Various Gases (Abstract), John A. Eldridge
Scattering Of Potassium Ions In Various Gases (Abstract), John A. Eldridge
Proceedings of the Iowa Academy of Science
Development of method for measurement of the scattering of ions projected as a beam with energies 50-400 e-volts. Results are given for scattering at different angles.
Compact Ionization Chamber-First Stage Unit (Abstract), W. B. Mclean, James Jacobs
Compact Ionization Chamber-First Stage Unit (Abstract), W. B. Mclean, James Jacobs
Proceedings of the Iowa Academy of Science
A compact ionization chamber-first stage unit for the detection of alpha particles and protons which has low sensitivity to mechanical vibration and high signal to noise ratio has been constructed, using a metal tube (6J7) which supports the collector plate of the ionization chamber directly on its grid cap, thus eliminating the usual flexible lead. This construction makes it possible to mount the entire unit in the position formerly occupied by the ionization chamber alone and dispense with any vibration-damping suspension for the tube.
An Electrical Circuit Designed For Use In A Calculating Instrument (Abstract), Ray Wendland
An Electrical Circuit Designed For Use In A Calculating Instrument (Abstract), Ray Wendland
Proceedings of the Iowa Academy of Science
Mathematical analysis of the potential variation produced by a circuit comprising two slide wire resistors (potentiometers) linked in parallel revealed the possibility of compensating the circuit so as to provide a potential varying as the product of the resistances in the individual slide wires. The problem was to counteract the fall in potential produced when a resistor is placed across a potentiometer circuit delivering an initial potential, E0. It was shown in the main report that a compensating resistor with the following characteristics would solve the problem, namely, Rx = R12 / R2 – …
A Precise Method For Determining The Efficiency Of Electric Range Units (Abstract), Margaret Woodrow
A Precise Method For Determining The Efficiency Of Electric Range Units (Abstract), Margaret Woodrow
Proceedings of the Iowa Academy of Science
The methods generally employed for determining the efficiency of electric range units do not account for the heat losses through the sides of the testing utensil and, sometimes, that lost through evaporation. Consequently, these determinations give too low a value for the efficiency of the units. By designing and using a vessel for which the heat losses could be accurately measured, the efficiencies of different types of units were determined. The efficiencies obtained by this method were considerably higher and more uniform than those determined by the usual methods.
The Evaporation Of Metals From Hot Filaments (Abstract), Wallace C. Caldwell
The Evaporation Of Metals From Hot Filaments (Abstract), Wallace C. Caldwell
Proceedings of the Iowa Academy of Science
Several investigators have used the evaporation technique for making surface mirrors, thermocouples, high resistances, and other devices. The method usually used involves attaching the metal to be evaporated to a refractory filament that is heated electrically. In this work the results of visual observations of wetting of the filament by the molten metal, of evaporation, and of any obvious alloying of the molten metal with the filament material enables the determination of the best filament to be used with each metal.
The Effect Of Thickness Of Stroke On The Legibility Of Letters, Julius E. Uhlaner
The Effect Of Thickness Of Stroke On The Legibility Of Letters, Julius E. Uhlaner
Proceedings of the Iowa Academy of Science
This is part of a study dealing with the optional characteristics for greatest efficiency of highway signs. Because there is still considerable room for improvement in the legibility of signs and only a limited amount of experimental data available, this investigation was undertaken. This present project is based on work done before by Lauer, (1932) Aldrich, (1937) Forbes, (1939) and deals on the whole with the separate variables of letter legibility such as stroke, height-width ratio and spacing, each variable being isolated for experimentation. In this paper, however, the discussion will deal only with the isolation of the stroke as …
A Voltage Stabilization Device For Rectified A.C. Power Sources (Abstract), L. E. Pinney
A Voltage Stabilization Device For Rectified A.C. Power Sources (Abstract), L. E. Pinney
Proceedings of the Iowa Academy of Science
The device is applicable to situations where currents of several milliamperes are required, as in the operation of low voltage X-ray tubes. With variation in line voltage not exceeding two per cent, fluctuations in output voltage, including ripple, are held within one-tenth per cent.