Growth Data from Sections of Acer saccharum

Nine sections of Acer saccharum were cut in 1940, following logging operations on the Albert Smith farm 13 miles southwest of Crawfordsville and about 3 miles east of Alamo, Indiana. Rainfall data were secured from the U.S. Weather Bureau Station which is located at Crawfordsville approximately 13 miles northeast from the forest in which the trees grew. Unfortunately, the rainfall data are not complete from 1884 through 1910; consequently, no growth-rainfall correlation could be determined for those years. Rainfall behavior charts were prepared for the rainfall periods May-August, May-June, May-July, June-July and June-August

The effect of precipitation on annular-ring growth in three species of trees from Brown County, Indiana

The present study is an attempt to determine what rainfall periods show the highest degree of correlation with growth in three species of deciduous trees from Brown County, Indiana, and to determine which area of the tree, i.e., the top or the bottom, gives the closest growth-rainfall correlation.Fuller has shown that there is a close correlation between precipitation for the calendar year in Illinois and increase in diameter in Quercus borealis maxima as shown by thickness of its annual growth rings. Kleine, Potzger, and Friesner, using 11 trees of Quercus alba, 17 of Quecrcus montana, 16 of Quercus velutina, and 9 of Quercus borealis maxima, found a correlation between annual growth and rainfall for the months June, July and August. This work, as in the present study, was done on sites with considerable relief and hence subject to excessive run-off

A Limited Habitable Zone for Complex Life

The habitable zone (HZ) is commonly defined as the range of distances from a host star within which liquid water, a key requirement for life, may exist on a planet's surface. Substantially more CO2 than present in Earth's modern atmosphere is required to maintain clement temperatures for most of the HZ, with several bars required at the outer edge. However, most complex aerobic life on Earth is limited by CO2 concentrations of just fractions of a bar. At the same time, most exoplanets in the traditional HZ reside in proximity to M dwarfs, which are more numerous than Sun-like G dwarfs but are predicted to promote greater abundances of gases that can be toxic in the atmospheres of orbiting planets, such as carbon monoxide (CO). Here we show that the HZ for complex aerobic life is likely limited relative to that for microbial life. We use a 1D radiative-convective climate and photochemical models to circumscribe a Habitable Zone for Complex Life (HZCL) based on known toxicity limits for a range of organisms as a proof of concept. We find that for CO2 tolerances of 0.01, 0.1, and 1 bar, the HZCL is only 21%, 32%, and 50% as wide as the conventional HZ for a Sun-like star, and that CO concentrations may limit some complex life throughout the entire HZ of the coolest M dwarfs. These results cast new light on the likely distribution of complex life in the universe and have important ramifications for the search for exoplanet biosignatures and technosignatures.Comment: Revised including additional discussion. Published Gold OA in ApJ. 9 pages, 5 figures, 5 table

An experimental study of the sensitivity of helicopter rotor blade tracking to root pitch adjustment in hover

The sensitivity of blade tracking in hover to variations in root pitch was examined for two rotor configurations. Tests were conducted using a four bladed articulated rotor mounted on the NASA-Army aeroelastic rotor experimental system (ARES). Two rotor configurations were tested: one consisting of a blade set with flexible fiberglass spars and one with stiffer (by a factor of five in flapwise and torsional stiffnesses) aluminum spars. Both blade sets were identical in planform and airfoil distribution and were untwisted. The two configurations were ballasted to the same Lock number so that a direct comparison of the tracking sensitivity to a gross change in blade stiffness could be made. Experimental results show no large differences between the two sets of blades in the sensitivity of the blade tracking to root pitch adjustments. However, a measurable reduction in intrack coning of the fiberglass spar blades with respect to the aluminum blades is noted at higher rotor thrust conditions

Desarrollo, implementación y publicación de un sistema geográfico para la gestión vial del cantón Cuenca

En la ciudad de Cuenca, el aumento del parque automotor conlleva un problema de congestión vehicular, a esto contribuye el cierre de vías por mejoras en la ciudad, estas circunstancias han provocado un malestar en los usuarios de sistemas públicos y privados de transporte, agravando el estrés urbano como consecuencia de la contaminación, el aumento de los tiempos de viaje,repercutiendo de forma económica y social en la población de Cuenca. Disponer de mapas y cartografía vial accesible desde dispositivos móviles como celulares, GPS, tablets, PDA, permite tener alternativas de circulación y brinda herramientas para generar rutas alternas para llegar a un destino. Una propuesta de gran acogida es la iniciativa Openstreetmap, la cual busca generar mapas viales del mundo a través de aportes hechos por usuarios entusiastas que usan las capturas de datos de GPS en el terreno, para luego ingresarla a la web. Algo similar se ha puesto en funcionamiento en la plataforma de la Universidad del Azuay con la información cartográfica vial actualizada y depurada a nivel 2, lo que representa vías principales y secundarias en diferentes formatos para su descarga. Este sitio también tiene accesos a los diferentes portales que disponen de información cartográfica vial

Photochemistry of Anoxic Abiotic Habitable Planet Atmospheres: Impact of New H2_2O Cross-Sections

We present a study of the photochemistry of abiotic habitable planets with anoxic CO$_2$-N$_2$ atmospheres. Such worlds are representative of early Earth, Mars and Venus, and analogous exoplanets. H$_2$O photodissociation controls the atmospheric photochemistry of these worlds through production of reactive OH, which dominates the removal of atmospheric trace gases. The near-UV (NUV; $>200$ nm) absorption cross-sections of H$_2$O play an outsized role in OH production; these cross-sections were heretofore unmeasured at habitable temperatures ($<373$ K). We present the first measurements of NUV H$_2$O absorption at $292$ K, and show it to absorb orders of magnitude more than previously assumed. To explore the implications of these new cross-sections, we employ a photochemical model; we first intercompare it with two others and resolve past literature disagreement. The enhanced OH production due to these higher cross-sections leads to efficient recombination of CO and O$_2$, suppressing both by orders of magnitude relative to past predictions and eliminating the low-outgassing "false positive" scenario for O$_2$ as a biosignature around solar-type stars. Enhanced [OH] increases rainout of reductants to the surface, relevant to prebiotic chemistry, and may also suppress CH$_4$ and H$_2$; the latter depends on whether burial of reductants is inhibited on the underlying planet, as is argued for abiotic worlds. While we focus on CO$_2$-rich worlds, our results are relevant to anoxic planets in general. Overall, our work advances the state-of-the-art of photochemical models by providing crucial new H$_2$O cross-sections and resolving past disagreement in the literature, and suggests that detection of spectrally active trace gases like CO in rocky exoplanet atmospheres may be more challenging than previously considered.Comment: Manuscript (this version) accepted to ApJ. Cross-section data available at https://github.com/sukritranjan/ranjanschwietermanharman2020. Feedback continues to be solicite

A comparison of Jersey sires : based on the average mature equivalent fat production of the daughters

Cover title

A comparison of Holstein-Friesian sires : based on the average "mature equivalent" fat production of the daughters

Cover title

Inelastic semiclassical Coulomb scattering

We present a semiclassical S-matrix study of inelastic collinear electron-hydrogen scattering. A simple way to extract all necessary information from the deflection function alone without having to compute the stability matrix is described. This includes the determination of the relevant Maslov indices. Results of singlet and triplet cross sections for excitation and ionization are reported. The different levels of approximation -- classical, semiclassical, and uniform semiclassical -- are compared among each other and to the full quantum result.Comment: 9 figure