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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.

The Address Of The President - The Cosmology Of The Universe, D. W. Morehouse

Proceedings of the Iowa Academy of Science

Astronomy is the original science. Its scope comprehends all the physical sciences - geology, physics, chemistry - and even the natural sciences. All borrow from it, and in turn contribute to astronomical knowledge. Moreover, from the very beginning, the study of astronomy has been inseparably connected with philosophy and religious speculation. For its theme - its age-long objective - has been a true world concept. I quote: "Back of every religion, and of every philosophy or science, worthy of the name, lies a world-view, a concept in which are included all localities and all beings supposed in that religion or …

Deductions From The Occurrence And Character Of Two Large Quartzose Conglomerate Boulders Of Unknown Origin Found In The Kansan Drift Sheet At Centerville, Iowa, Ben H. Wilson

Proceedings of the Iowa Academy of Science

On a lawn at No. 629 West Maple Avenue, in Centerville, Iowa, are located two large quartzose conglomerate boulders which are of more than usual interest. These were removed from the glacial till during the process of excavating for the cellar under the dwelling now situated on the same lot and when found were said to be buried beneath several feet of drift material.

Hall Effect And Specific Resistance In Evaporated Films Of Silver, Copper And Iron, J. C. Steinberg

Proceedings of the Iowa Academy of Science

Previous investigators have found the specific resistance a constant for metallic films, until the thickness becomes comparable with particle dimensions, at which thickness the resistance becomes very great. Wait found the resistivity of chemically deposited silver films, whose thicknesses were greater than the above mentioned critical thickness, to be only slightly greater than that of the bulk metal. He found the Hall Effect in these films, as well as in films whose thicknesses were less than the critical thickness, to be the same as that of bulk silver. On the conception that the substance in a film consists of granules …

Simultaneous Fast And Slow Drum Records Of Fatigue, Francis Marsh Baldwin

Proceedings of the Iowa Academy of Science

The essential details of fatigue processes as they develop in a properly prepared protoplasmic system like that of a frog muscle, are conveniently transcribed by the writing lever either upon a kymograph drum revolving comparatively rapidly, or one going very slowly and these records furnish data for subsequent analysis. In each procedure some facts' are obtained as to amplitude, enhancing and diminution of responses under a given rate of stimulation and under certain physical and physiological conditions, but unfortunately neither method alone suffices for the proper analysis of the whole process. Although details of mechanical devices differ somewhat in the …

Chance In Development As A Cause Of Variation, P. W. Whiting

Proceedings of the Iowa Academy of Science

Variation is ordinarily considered as due to internal hereditary factors interacting with external environmental factors during development. In experimental work with a parasitic wasp considerable variation has been found in certain pure-bred stocks kept at certain constant environmental conditions. Either at other constant environmental conditions or in other pure-bred stocks this variation does not occur. Variation appearing under uniform conditions of heredity and environment is considered as due to slight irregularities of division and distribution of cells during embryology and to other more or less intangible factors of development. Individual variation resulting from chance in development is on the average …

The Founders Of The Art Of Plant Breeding, Fred C. Werkenthin

Proceedings of the Iowa Academy of Science

The paper by Prof. Werkenthin on History of Plant Breeding was one of the assigned topics in the course given at Iowa State College on the History of Botany. The subject matter is so admirably treated that it has seemed wise to publish this as a posthumous paper. It was the last paper prepared by him, finished only a few weeks before he was taken sick.

The Structure And Development Of The Seed Coat And Cause Of Delayed Germination In Mellilotus Alba, J. N. Martin

Proceedings of the Iowa Academy of Science

The epidermis of the ovules forms the much elongated cells, known as the Malpighian cells of the seed coat. The outer walls of the Malpighian cells are much thickened and are composed of layers differing in physical properties. One of these layers is the light line which in most seeds is impervious to water until it is modified by weathering or by some artificial means. The light line is apparently only more compact cellulose for it hydrates quickly in water at 80° C. and then gives a distinct cellulose reaction and is permeable to water. The action of the weather …