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The Optical Constants Of Crystals Of Selenium Tellurium For Wave-Lengths From 3000 To 5000 A, R. F. Miller Jan 1924

The Optical Constants Of Crystals Of Selenium Tellurium For Wave-Lengths From 3000 To 5000 A, R. F. Miller

Proceedings of the Iowa Academy of Science

The measurements were made by a photographic method, for two positions of the crystal (1) with the optic axis parallel, and (2) with the axis perpendicular, to the plane of incidence. Two sets of optical constants were found for each substance. For selenium, in the parallel position the index of refraction was found to vary from 3.4 to 4.4, and the reflecting power from 0.38 to 0.46; in the perpendicular position the index varies from 2.3 to 3.1, and the reflecting power from 0.41 to 0.34. For tellurium, in the parallel position the index varies from 1.9 to 2.9, and …

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The Hall Effect And Specific Resistance In Evaporated Films Of Nickel, Cobalt, Palladium And Platinum, H. B. Peacock Jan 1924

The Hall Effect And Specific Resistance In Evaporated Films Of Nickel, Cobalt, Palladium And Platinum, H. B. Peacock

Proceedings of the Iowa Academy of Science

Steinberg has shown that in the case of a thin film of metal formed by evaporation from a heated filament in a high vacuum the specific resistance and Hall coefficient are not the same as for the bulk metal. The metals investigated were silver, copper and iron, and in all of these the specific resistance was found to be about 1000% greater than in the metals in bulk. The Hall coefficients were slightly smaller for silver and copper than for the bulk metals, but for iron this coefficient was about 600% greater than the value generally accepted for iron. Also, …

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The Intrinsic Intensity And Percent Of Polarization Of Light Transmitted Through Deep Slits, L. P. Sieg Jan 1924

The Intrinsic Intensity And Percent Of Polarization Of Light Transmitted Through Deep Slits, L. P. Sieg

Proceedings of the Iowa Academy of Science

It is assumed that the light incident upon the first opening of a slit between various metals is diffracted in the usual manner, and finally emerges from the far end of the slit after repeated reflections. The reflecting coefficients of the various metals considered are calculated for the proper angles of incidence from a knowledge of the index of refraction of the metal, and from its coefficient of absorption. In view of the fact that the coefficients of reflections for light possessing an electric vector perpendicular are much larger than for light with the electric vector parallel to the plane …

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The Effect Of The Material Composing The Sides Of Deep Slits On The Intrinsic Intensity Of Light Transmitted Through The Slits, Clarence R. Smith Jan 1924

The Effect Of The Material Composing The Sides Of Deep Slits On The Intrinsic Intensity Of Light Transmitted Through The Slits, Clarence R. Smith

Proceedings of the Iowa Academy of Science

It is shown that differences in intensity of the light transmitted by a narrow, deep slit are produced by changing the material of the sides though other conditions are kept constant. With a pair of optically plane surfaces of each of the metals, steel, nickel, gold, silver and copper, a slit was prepared which could be varied in width while the depth remained constant. For each of these metals a curve was prepared showing the variation of transmitted light intensity with change in width of slit. Comparison of the curves for the various metals shows a fairly close agreement for …

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The Action Of A Helmolts Resonator In A Branch Line, G. W. Stewart Jan 1924

The Action Of A Helmolts Resonator In A Branch Line, G. W. Stewart

Proceedings of the Iowa Academy of Science

The general impression of a Helmholtz resonator is that, since its dissipation is small, its tuning is fairly sharp. It is noted with some surprise, therefore, that when used as a side branch in an acoustic transmission line it affects the transmission over a wide range of frequencies. The theory, derived from the general case in the preceding abstract has been checked by experiment with resonators of varying dimensions and the theory verified to a very satisfactory degree.

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Theory Of Megaphones And Receiving Horns, G. W. Stewart, G. R. Butz Jan 1924

Theory Of Megaphones And Receiving Horns, G. W. Stewart, G. R. Butz

Proceedings of the Iowa Academy of Science

In 1919, A. G. Webster published a theory of the action of horns used as receivers. Recent development has given an increased interest in the megaphone. Webster's theory may be modified to cover the case of the megaphone, assuming the constancy of the acoustic point impedance of the horn at the source. The result obtained is that the emitted energies at different frequencies are related as are the values of [(ad-bc)/(a-cz2)]2 wherein a, b, c and d, have the values specified in Webster's theory and z2=δa2k2 (ki/2π-1/c0), k being 2π …

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The M Absorption Limits Of The Tungsten X-Ray Spectrum, R. V. Zumstein Jan 1924

The M Absorption Limits Of The Tungsten X-Ray Spectrum, R. V. Zumstein

Proceedings of the Iowa Academy of Science

The x-ray spectrum of tungsten has been investigated from 7 to 3 Angstrom Units, using a metal x-ray tube and a vacuum spectrometer.

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A Note On Daylight Requirement, Wm. Kunerth Jan 1924

A Note On Daylight Requirement, Wm. Kunerth

Proceedings of the Iowa Academy of Science

Two years ago the author read a short paper in which he gave the intensity of illumination required when direct lighting is used as compared with what is required when indirect lighting is employed. Experimental results were given based on the average obtained from 26 college seniors. The data showed that 2.8 ft. candles were desirable for reading by direct lighting and 4.0 ft. candles by indirect lighting, both being median value. Only artificial light was used.

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The Differential Death-Rate Of The Sexes Among Animals, With A Suggested Explanation, S. W. Geiser Jan 1924

The Differential Death-Rate Of The Sexes Among Animals, With A Suggested Explanation, S. W. Geiser

Proceedings of the Iowa Academy of Science

It has been conclusively demonstrated in certain mammals, fishes, arthropods, nematodes and mollusks that the female sex has a greater longevity than the male. (Geiser, '21, '23; et al.) Longevity within the species appears to be inherited in the manner of "blending inheritance," i.e., its mode of inheritance is probably through a series of multiple gametic factors. (Beeton & Pearson, '00, '01; Pearl, Parker & Gonzalez, '23; Gonzalez, '23.)

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Results Of The Testing Program Given At Iowa State College, Nora M. Klise Jan 1924

Results Of The Testing Program Given At Iowa State College, Nora M. Klise

Proceedings of the Iowa Academy of Science

The results given in this report were based upon a study of 368 Home Economics students who had been given mental tests in the spring and fall of 1919. 145 of the 368 had been given Alpha mental test, and 223, Thorndike. High school records were available for 339 of them. The object was to study criteria for prediction of college scholarship. Alpha had the highest correlation with college average, 0.45 as compared with 0.34 for high school with college average, and 0.38 for Thorndike with college average. English had the highest correlation, with college average (0.59) of any individual …

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Three Different Types Of Genetic Sterility In The Parasitic Wasp, Habrobracon, P. W. Whiting Jan 1924

Three Different Types Of Genetic Sterility In The Parasitic Wasp, Habrobracon, P. W. Whiting

Proceedings of the Iowa Academy of Science

Almost complete sterility may be induced by imperfect fertilization. Resulting male offspring very rarely produce daughters which are almost always sterile. Complete sterility of males due to lack of external genitalia exists in one strain, which is reproduced from sisters and fertile brothers. A previously fertile strain mutated so that females lay inviable eggs. Rarely an egg will hatch and from the resulting insect the strain is perpetuated. Males of this strain are of normal fertility.

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Two Generations Of Selection With Reference To The Inheritance Of Scurvy Resistance In Guinea-Pigs, W. V. Lambert Jan 1924

Two Generations Of Selection With Reference To The Inheritance Of Scurvy Resistance In Guinea-Pigs, W. V. Lambert

Proceedings of the Iowa Academy of Science

Selection over two generations for increased and decreased resistance to scurvy in guinea-pigs has failed to produce conclusive evidence that the individual variations noted in resistance toward scurvy are inherited. An analysis of the effect of age, weight, and vigor as influencing resistance is presented and it is concluded that these factors, within the limits represented in the data, have not influenced the results. The results for the first generation of selection indicate a pronounced influence, but in the second generation the difference between the minus and plus selections is not significant.

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Proceedings Of The Thirty-Eighth Annual Meeting Of The Iowa Academy Of Science, Held At Ames, May 2 And 3, 1924: Minutes Of The Meeting; Staff & Committee Reports Jan 1924

Proceedings Of The Thirty-Eighth Annual Meeting Of The Iowa Academy Of Science, Held At Ames, May 2 And 3, 1924: Minutes Of The Meeting; Staff & Committee Reports

Proceedings of the Iowa Academy of Science

No abstract provided.

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Studies On The Role Of Rye In The Vienna Process For Yeast Manufacture, Ellis I. Fulmer, Roma Elmer Jan 1924

Studies On The Role Of Rye In The Vienna Process For Yeast Manufacture, Ellis I. Fulmer, Roma Elmer

Proceedings of the Iowa Academy of Science

A water extract of rye shows an optimum concentration for its effect in causing top growth of yeast. Quantitative studies were reported on the distribution of the yeast throughout a column with various concentrations of the extracts at varying stages in fermentation. Data are discussed relative to the effect of various concentrations of the extract upon the composition of the yeast especially with reference to fat content.

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Three Maxims For The Study Of The Nutrition Of Microorganisms, Ellis I. Fulmer Jan 1924

Three Maxims For The Study Of The Nutrition Of Microorganisms, Ellis I. Fulmer

Proceedings of the Iowa Academy of Science

I. The relative potencies of two materials cannot be arrived at by the comparison of the effects of the two materials at equal concentrations. Corollary: The effect of treatment upon the potency of a material cannot be determined by the comparison of the treated and untreated material at equal concentrations. II. The relative potencies of two materials at one temperature may not be true for any other temperature. Corollary: Temperature coefficients for the effect of a material must be determined under optimum conditions for each temperature. III. If two materials are to be compared as a source of a protoplasmic …

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The Alumni News Letter, V7n4, October 1, 1923, Iowa State Teachers College Oct 1923

The Alumni News Letter, V7n4, October 1, 1923, Iowa State Teachers College

The Alumni News Letter

Contains news of the College and its alumni.

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Iowa State Teachers College Program Of Recitations, Fall 1923, Iowa State Teachers College Oct 1923

Iowa State Teachers College Program Of Recitations, Fall 1923, Iowa State Teachers College

UNI Schedule of Classes

A listing and schedule of the courses being taught as well as policies and procedures concerning attending classes at the Iowa State Teachers College.

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The Alumni News Letter, V7n3, July 1, 1923, Iowa State Teachers College Jul 1923

The Alumni News Letter, V7n3, July 1, 1923, Iowa State Teachers College

The Alumni News Letter

Contains news of the College and its alumni.

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The Alumni News Letter, V7n2, April 1, 1923, Iowa State Teachers College Apr 1923

The Alumni News Letter, V7n2, April 1, 1923, Iowa State Teachers College

The Alumni News Letter

Contains news of the College and its alumni.

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The Reflecting And The Absorbing Power Of A Photographic Emulsion, P. S. Helmick Jan 1923

The Reflecting And The Absorbing Power Of A Photographic Emulsion, P. S. Helmick

Proceedings of the Iowa Academy of Science

Measurements have been made upon the reflecting and the absorbing power of silver bromide emulsion with wave-lengths between 2100A and 5782A. The reflecting power of silver bromide emulsion averages about 7 per cent for the region 2100A to 5200A. A thickness of emulsion (0.021 mm) as found in a commercial photographic film absorbs about 96 per cent of incident radiation between 5218A and 5782A, and more than 99.99 per cent of radiation whose wave-length is less than 3247 A. From 5782A to at least 2294A the gelatine in a photographic emulsion has a negligible absorption as compared with the absorption …

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A New Apparatus For Measuring Deep Water Temperatures, Frank A. Stromsten Jan 1923

A New Apparatus For Measuring Deep Water Temperatures, Frank A. Stromsten

Proceedings of the Iowa Academy of Science

There has always been a certain fascination in the study of things related to great bodies of water. The curiosity to know what is going on beneath the turbulent waves when the storm is raging and what the conditions are beneath the smooth surface when all is quiet has ever challenged our spirit of investigation. What are the environmental conditions of aquatic life has given considerable impetus to the physical and chemical phases of limnology. Temperature seems so closely interwoven into the environmental complex that careful and exact measurement of this factor is one of the first things to be …

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A Simple High Frequency Alternator, C. J. Lapp Jan 1923

A Simple High Frequency Alternator, C. J. Lapp

Proceedings of the Iowa Academy of Science

High frequency alternating currents are receiving more attention in physics than ever before. Most of the recent high frequency generating devices have employed vacuum tubes. There are lines of research, however, where mechanical generators are desired.

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The Alumni News Letter, V7n1, January 1, 1923, Iowa State Teachers College Jan 1923

The Alumni News Letter, V7n1, January 1, 1923, Iowa State Teachers College

The Alumni News Letter

Contains news of the College and its alumni.

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In Memoriam: Gustavus Detlef Hinrichs; James Edward Todd, Charles Keyes Jan 1923

In Memoriam: Gustavus Detlef Hinrichs; James Edward Todd, Charles Keyes

Proceedings of the Iowa Academy of Science

No abstract provided.

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Synthetic Hypnotics In The Barbituric Acid Series, Arthur W. Dox Jan 1923

Synthetic Hypnotics In The Barbituric Acid Series, Arthur W. Dox

Proceedings of the Iowa Academy of Science

The increasing demand for sleep-producing drugs is perhaps one of the characteristics of the restless age in which we now live. Not a year passes but half a dozen new synthetic hypnotics appear in the patent literature and a few of these find their way into the drug market. Most of these fail to meet the claims made by the manufacturers and are soon discarded, and the physicians continue to prescribe the eight or ten more or less familiar drugs that have survived several decades of clinical experience. Meanwhile, the chemical and pharmaceutical laboratories continue their search for the ideal …

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An Excellent Example Of High Clay Bank Erosion In Lee County, Iowa, Ben H. Wilson Jan 1923

An Excellent Example Of High Clay Bank Erosion In Lee County, Iowa, Ben H. Wilson

Proceedings of the Iowa Academy of Science

There are at least two pre-glacial valleys in Lee County, which is situated in the extreme southeast corner of the state of Iowa, the first running nearly parallel to the present course of the Mississippi, and the other roughly parallel with the valley of the Des Moines. These valleys were once occupied by great mid-continental streams, whose geological age has never been fully determined. Their waters eroded channels several miles in width through the indurated rocks of the Carboniferous, over which they passed, to a depth considerably below the present grade of the water courses with which they are analogous.

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New Vibrations Within A Conical Horn, Victor A. Hoersch Jan 1923

New Vibrations Within A Conical Horn, Victor A. Hoersch

Proceedings of the Iowa Academy of Science

In the case of simple harmonic motion, the time factor being eiσt, the velocity potential Φ of the vibrations must satisfy the equation (Δ2 + k2) Φ = 0. Where k = σ /c in which c is the velocity of sound.

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Plants And The Surface Film Of Water, Robert B. Wylie Jan 1923

Plants And The Surface Film Of Water, Robert B. Wylie

Proceedings of the Iowa Academy of Science

The plant's uses of water are many. As a solvent water permits the absorption of raw materials of all kinds taken in by the plant. Within the plant body water performs many functions, some of it even entering into the constitution of the protoplasm itself. In leaving the plant in the form of vapor its evaporation cools the tissues when otherwise they might at times be injured by the radiant energy of the sun to which extensive portions of the plant must he exposed for photosynthesis. The familiar root-shoot type of land vegetation is the form-response of plants to the …

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The Effect Of Impurities On The Physical Properties Of Oxychloride Cements, H. L. Olin, Ben H. Peterson Jan 1923

The Effect Of Impurities On The Physical Properties Of Oxychloride Cements, H. L. Olin, Ben H. Peterson

Proceedings of the Iowa Academy of Science

The rapidly increasing use of Stucco, a cement made by mixing magnesite with a solution of magnesium chloride, as an exterior for dwelling houses has given rise to an interesting study of its chemical and physical properties. As usually applied, the stucco is made according to the specifications of the Committee on Specifications for Plastic Magnesite, which recommended the following mixture to be standard: One part by weight of plastic calcined Magnesite; Two parts by weight of Standard Ground Silica; Five parts by weight of Standard Ottawa Sand. This is then mixed with a 22 degree Baume solution of magnesium …

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1923 Old Gold, Iowa State Teachers College Jan 1923

1923 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.

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