Spectral Energy Distributions for Disk and Halo M--Dwarfs

We have obtained infrared (1 to 2.5 micron) spectroscopy for 42 halo and disk dwarfs with spectral type M1 to M6.5. These data are compared to synthetic spectra generated by the latest model atmospheres of Allard & Hauschildt. Photospheric parameters metallicity, effective temperature and radius are determined for the sample. We find good agreement between observation and theory except for known problems due to incomplete molecular data for metal hydrides and water. The metal-poor M subdwarfs are well matched by the models as oxide opacity sources are less important in this case. The derived effective temperatures for the sample range from 3600K to 2600K; at these temperatures grain formation and extinction are not significant in the photosphere. The derived metallicities range from solar to one-tenth solar. The radii and effective temperatures derived agree well with recent models of low mass stars.Comment: 24 pages including 13 figures, 4 Tables; accepted by Ap

Effect of Time of Cutting on Yield and Botanical Composition of Prairie Hay in Southeastern Nebraska

Approximately three and one-third million acres of native prairie are harvested annually in Nebraska for hay. In the four-year period 1948-1951, the State ranked first in wild hay production with an average yield of more than two and one-quarter million tons per year. This crop is an important natural resource in Nebraska\u27s livestock industry. Studies were initiated in 1945 to determine the effects of time of cutting on the yield and feeding value of prairie hay in southeastern Nebraska. The studies were continued through the summer of 1952 to determine the effects of different cutting treatments on the vigor and botanical composition of the vegetation. A separate study was initiated in 1948 and continued through 1952 to determine the effect of time of harvesting the aftermath crop in the fall on the yield of hay the following summer

Measurements of Wood Fiber

Many of the properties of wood depend upon the character and arrangement of the fiber cells which enter into its composition. This is especially true of those properties which determine its strength, hardness and adaptability for the manufacture of paper pulp. With a view to throwing light on these properties, we have made measurements of the length and diameter of the fibers in forty-one species of trees. No attempt was made to segregate the various types of fiber that occur in different species. We have taken any of the slender, fusiform, non-septate, thick walled members of the xylem. The maximum and minimum figures indicate that this lack of discrimination has not introduced any serious error. Were very critical discrimination attempted, the comparison of species would prove unduly complex, if not impossible

The Mosses of Southwestern Iowa

The territory of southwestern Iowa in this report includes Harrison, Shelby, Audubon, Guthrie, Pottawatamie, Cass, Adair, Mills, Montgomery, Adams, Union, Fremont, Page, Taylor and Ringgold counties. Four of these border the Missouri state line and four are along the Missouri river. About half the region is prairie, unmodified by erosion or the deposition of loess in hills. The mosses were collected on the wooded banks of streams or in cultivated land. The collections were made mostly by Dr. Conard during 1930-1933. They are obviously incomplete. In some counties only one stop was made for collecting, in others the work was done more thoroughly

The Solar Neighborhood. XXXIX. Parallax Results from the CTIOPI and NOFS Programs: 50 New Members of the 25 Parsec White Dwarf Sample

We present 114 trigonometric parallaxes for 107 nearby white dwarf (WD) systems from both the Cerro Tololo Inter-American Observatory Parallax Investigation (CTIOPI) and the U. S. Naval Observatory Flagstaff Station (NOFS) parallax programs. Of these, 76 parallaxes for 69 systems were measured by the CTIOPI program and 38 parallaxes for as many systems were measured by the NOFS program. A total of 50 systems are confirmed to be within the 25 pc horizon of interest. Coupled with a spectroscopic confirmation of a common proper motion companion to a Hipparcos star within 25 pc as well as confirmation parallax determinations for two WD systems included in the recently released Tycho Gaia Astrometric Solution (TGAS) catalog, we add 53 new systems to the 25 pc WD sample $-$ a 42% increase. Our sample presented here includes four strong candidate halo systems, a new metal-rich DAZ WD, a confirmation of a recently discovered nearby short-period (P = 2.85 hr) double degenerate, a WD with a new astrometric pertubation (long period, unconstrained with our data), and a new triple system where the WD companion main-sequence star has an astrometric perturbation (P $\sim$ 1.6 yr).Comment: 32 pages, 12 figures. Figure 4 in the manuscript is a representative set of plots - plots for all WDs presented here are available (allfits_photo.pdf, allfits_photo_DQ.pdf, and allfits_photo_DZ.pdf). Accepted for publication in The Astronomical Journa