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Officers, Past Presidents, And Members, Iowa Academy Of Science

Proceedings of the Iowa Academy of Science

No abstract provided.

Table Of Contents

Proceedings of the Iowa Academy of Science

No abstract provided.

The Progress Of Research In The Coe College Radiological Laboratory, Scott W. Smith Jr.

Proceedings of the Iowa Academy of Science

Ever since the discovery of x-rays by Prof. W. K. Röntgen in 1895, the physicist has played an important part in the advancement of knowledge leading to the use of x-rays in therapy. Doctor Coolidge with his high voltage tube made it possible to produce very penetrating x-rays; while Professor Dessauer of Germany in his study of the distribution of x-rays, Professor Duane of Harvard, and many other physicists, have aided materially in the harnessing of this potent form of radiation for use in therapy. Therefore in the establishment of the Radiological Research Bureau of Coe College, the primary aim …

Magnetic And Natural Rotatory Dispersion In Absorbing Media, E. O. Hulburt

Proceedings of the Iowa Academy of Science

A theoretical discussion based on the electron theory of H. A. Lorentz yielded formulas for the magnetic rotatory dispersion in isotropic absorbing media and for the natural rotatory dispersion in optically active absorbing media. In a few instances where sufficient data enabled calculation, the new magnetic rotation formula has given accurate agreement with experimental values, thereby accounting for the discrepancy previously noted between the observed Verdet angles and those calculated from a theory which neglected absorption.

The Deflection Of A Stream Of Electrons By Electromagnetic Radiation, E. O. Hulburt

Proceedings of the Iowa Academy of Science

A theoretical calculation, based on classical electrodynamics, gives for the maximum angular deflection, when certain approximations are made, He/mφ, where ω/2π is the frequency of the radiation, and H is the field due to it. For sunlight (H=.04) the value is only 4 X 10^-10, far too small to detect experimentally, while for intense x-rays, the value is of the order of 10^-13. Recently C. J. Lapp reported having obtained an observable deflection with x-rays. If further research should confirm this result, it would appear to be in direct conflict with the classical …

Comparative Rates Of Oxygen Consumption In Marine Forms, Francis M. Baldwin

Proceedings of the Iowa Academy of Science

The present paper presents data gathered by the writer in a study made on the rate of oxygen consumption in some of the marine fishes and invertebrates, and gives additional weight to a report by Professor Scott before the Society of Experimental Biology, XII, pp. 146-147.

Equilibrium Between Strontium Bromide And Bromine In Aqueous Solutions Of Strontium Bromide, J. N. Pearce, J. V. O'Leary

Proceedings of the Iowa Academy of Science

The study of the equilibrium between bromine and the uni-univalent bromides, more especially potassium bromide, in aqueous solution has been the subject of numerous investigations. It has become a generally accepted idea that an ionizable compound is formed of the type, KBr + Br₂ = KBr’ Br₂.

The Free Energy Of Dilution And The Activities Of The Ions Of Hydrogen Iodide In Aqueous Solutions, J. N. Pearce, A. R. Fortsch

Proceedings of the Iowa Academy of Science

Because of their anomalous behavior solutions of strong electrolytes have long occupied the attention of numerous investigators. Many attempts have been made to provide a theoretical explanation of the abnormalities. Of the various solution properties the free energies of dilution and the activities of the ions have been especially studied. From calculations based on the assumption that a common ion at any given concentration has the same mobility regardless of the associated ion Lewis has concluded that the chlorides, bromides and iodides of hydrogen and of the alkali halides are equally dissociated in 0.10 M solutions.

Index

Proceedings of the Iowa Academy of Science

No abstract provided.

The Trace Left By A Helical Beam Of Electrons On A Plane Perpendicular To Its Axis, C. J. Lapp

Proceedings of the Iowa Academy of Science

Experimental work has been done by the writer in which a fine beam of electrons was caught in a magnetic field and turned into a spiral. A photographic plate placed across the path was marked by a trace which at first appeared to be a circle. A close examination however showed that the trace was unsymmetrical and that its curvature appeared to change with the length of Arc.

Proceedings Of The Thirty-Seventh Annual Meeting Of The Iowa Academy Of Science, Held At Mount Vernon, April 27 And 28, 1923: Minutes Of The Meeting; Staff & Committee Reports

Proceedings of the Iowa Academy of Science

No abstract provided.

On Super-Regeneration, E. O. Hulburt

Proceedings of the Iowa Academy of Science

A simple mathematical analysis of super-regeneration yielded conclusions, in accordance with observation, that the super-regenerative system amplifies without distortion and that the amplification increases with increase of signal frequency and with decrease of variation frequency. Two single tube super-regenerative circuits, interesting because of their simplicity, are described.

The Natural Ultra-Violet Frequency Of Silver Bromide, P. S. Helmick

Proceedings of the Iowa Academy of Science

The ultra-violet maximum of the selective photo-electric effect can he calculated by expressions given by the following authorities: Lubben, v ion = v undissolved salt + 2 Q/N h; Haber and Lewis, Q = N h (Σ v resultants - v reactants); Haber, v_v/ v _r = √M/m; Lindeman, V_v = √ n e²/m r³/π; where v =critical frequency in ultra-violet (v) or infra-red (r), N=Avogadro's constant, h =Planck's element of action, M=molecular weight of the substance, n =valency of atom to which electron belongs, e =charge on an electron, and …

1923 Little Tutor, Iowa State Teachers College High School

Malcolm Price Laboratory School Yearbooks

The student yearbook of the Teachers College High School (later the Northern University High School, part of the Malcolm Price Laboratory School of the University of Northern Iowa).

College Circular [Catalog] 1923, Iowa State Teachers College

UNI Programs and Courses Catalogs

Table of Contents

Calendar for 1923-24 ... 5
Officers of Administration and Instruction ... 6
General Information ... 35
Residence, Student Health, Assembly ... 36
Expenses and Fees ... 36
Free Scholarships ... 38
Extension Service ... 38
College Organizations ... 39
Faculty Organizations ... 40
Training in Actual Teaching ... 40
Public Lectures and Entertainments ... 41
Boarding and Lodging ... 41
Employment of Students ... 42
Twelve Weeks Normal Training ... 42
School Credits in Lieu of Certificate Examinations ... 43
Examinations for Teachers Certificates ... 43
Department Certificates ... 44
Bureau of Recommendations ... 44
Advisers and …

Fall Term Commencement [Program], December 5, 1922, Iowa State Teachers College

UNI Commencement Programs

The program of the commencement ceremonies, including a list of institutional leadership, a list of the departments by college, awards given at the ceremonies, and a list of undergraduate and graduate degree candidates.

The Alumni News Letter, V6n4, October 1, 1922, Iowa State Teachers College

The Alumni News Letter

Contains news of the College and its alumni.

The Alumni News Letter, V6n3, July 1, 1922, Iowa State Teachers College

The Alumni News Letter

Contains news of the College and its alumni.

Spring Term Commencement [Program], May 30, 1922, Iowa State Teachers College

UNI Commencement Programs

The program of the commencement ceremonies, including a list of institutional leadership, a list of the departments by college, awards given at the ceremonies, and a list of undergraduate and graduate degree candidates.

The Alumni News Letter, V6n2, April 1, 1922, Iowa State Teachers College

The Alumni News Letter

Contains news of the College and its alumni.

The Alumni News Letter, V6n1, January 1, 1922, Iowa State Teachers College

The Alumni News Letter

Contains news of the College and its alumni.

College Catalog And Circular 1922, Iowa State Teachers College

UNI Programs and Courses Catalogs

Table of Contents

Calendar for 1922-23 ... 5
Officers of Administration and Instruction ... 6
General Information ... 33
Residence, Student Health, Assembly ... 37
Expenses and Fees ... 37
Free Scholarships ... 39
Extension Service ... 39
College Organizations ... 40
Faculty Organizations ... 41
Training in Actual Teaching ... 41
Public Lectures and Entertainments ... 41
Boarding and Lodging ... 42
Employment of Students ... 43
Twelve Weeks Normal Training ... 43
School Credits in Lieu of Certificate Examinations ... 44
Examinations for Teachers Certificates ... 44
Department Certificates ... 44
Bureau of Recommendations ... 45
Degree Curriculums …

1922 Old Gold, Iowa State Teachers College

UNI Yearbooks

The student yearbook of the Iowa State Teachers College, later known as the University of Northern Iowa.

In Memoriam: Fred C. Werkenthin; Chalmers Colin Norwood, John N. Martin, Ben Hur Wilson

Proceedings of the Iowa Academy of Science

No abstract provided.

Structure And Function Of The Stigma In Relation To The Germinative Requirements Of The Pollen In The Easter Lily, J. N. Martin, Fred C. Werkenthin, Elizabeth Hudson

Proceedings of the Iowa Academy of Science

Stigma of Easter Lily is papillate. Over the surface of the papillae a mucilaginous layer is formed and from this mucilaginous layer the pollen absorbs the requisite amount of water for germination. The papillae and nearly all cells of the stigma previous to the opening of the flower contain much starch which is transported from cell to cell chiefly in the form of dextrin. As the starch disappears in the papillae the mucilage appears on the outside of their walls. The pollen germinates on almost any media or in almost any solution that furnishes the required amount of water.

Proceedings Of The Thirty-Sixth Annual Session Of The Iowa Academy Of Science, Drake University, Des Moines, April 28 And 29, 1922: Minutes Of The Meeting; Staff & Committee Reports

Proceedings of the Iowa Academy of Science

No abstract provided.

A Redetermination Of The Principle Reflecting Powers Of Isolated Selenium Crystals, L. P. Sieg

Proceedings of the Iowa Academy of Science

Some time ago, following the publication of a paper by one of my former students, Mr. C. H. Skinner, I attempted to check his results by direct experiment. The paper referred to dealt with the optical constants of isolated selenium crystals. Of these constants, the reflecting power is the only one that offers itself to an easy experimental test. It must be said that the results obtained by Skinner were obtained by indirect means, and since the equations used in reducing his results to optical constants were somewhat complicated, and rested on foundations none too sure, it was important for …

The Attenuation Factors In Acoustic Wave Filters, H. B. Peacock

Proceedings of the Iowa Academy of Science

A theory has been formulated by Dr. G. W. Stewart by which it is possible to determine the selective transmission in three types of specially constructed acoustic wave filters. The theoretical attenuation factor also has been worked out and shows fair agreement with experimental results. Theoretical values of the attenuation were computed for one filter of each type and, from these values, the theoretical transmission curves were determined. The types of filters were the low-frequency and high-frequency— pass, and the single band.

Coefficients Of Diffusion Of Salt Vapors In The Bunsen Flame, George E. Davis

Proceedings of the Iowa Academy of Science

The coefficients of diffusion of alkali salts in the Bunsen flame have been determined by a photographic method which is a modification of the method used by H. A. Wilson. The values of the diffusion coefficients obtained for sodium, potassium, and caesium salts are roughly proportional to the reciprocals of the atomic weights of the metals. This is what we should expect from kinetic theory, if we consider the luminosity to be due to free metal atoms in the flame. Lithium salts, however, are found to have a lower coefficient of diffusion than sodium salts, and hence their metal atoms …

Officers, Past Presidents, And Members, Iowa Academy Of Science

Proceedings of the Iowa Academy of Science

No abstract provided.