7,490 research outputs found
Some Effects of Fertilization on Nitrification in High-Lime Soils
Applications of potassium chloride at the rate of 100, 200 and 500 pounds per acre were made on two soils containing a high calcium content. Oat straw at the rate of 2 tons of dry matter per acre was applied alone and in combination with potassium chloride. Sweet clover at the rate of 2 tons of dry matter per acre was applied alone and in combination with potassium chloride. Samples of the soils were taken 4 weeks after treatment in the greenhouse and again after 5 months for nitrification determinations
The Effects of Potash and Crop Residues on Available Potassium in Some Alkali Soils of Iowa
Many investigators have found that high-lime soils may often be deficient in available potassium. According to the present theory, the low availability of the potassium in such soils is probably due to the high concentrations of calcium salts. The so-called alkali soils of Iowa have been found to contain high concentrations of both calcium carbonate and calcium bicarbonate. Apparently the concentrations of these salts are so high that they tend to depress the availability of the potassium in the soil
The Polarized Spectrum of Apm 08279+5255
We report the discovery of significant linear polarization (p > 1%) in the
hyperluminous z=3.87 BALQSO APM~08279+5255. The polarization spectrum is
complex, with properties similar to those of other, lower redshift but more
highly polarized BALQSOs. The resonance emission lines are unpolarized while
the absorption troughs show polarization similar to or higher than the
continuum. In particular, an apparent increase of polarization in the trough
covering 1000-1030 angstroms (rest) supports the interpretation of this feature
as a broad absorption component associated with OVI/Ly_beta local to the QSO,
as opposed to an intervening damped Ly_alpha absorption system.
The elevated polarization in some of the absorption features implies that we
view the scattered (polarized) spectrum through a sightline with less absorbing
material than the direct spectrum. Therefore, the complex structure of the
polarization spectrum in this brilliant lensed BALQSO suggests that it will be
an important laboratory for studying the structure of QSOs at high redshift.Comment: 8 pages, 1 figure. Accepted for publication in The Astrophysical
Journal Letter
An Extraordinary Scattered Broad Emission Line in a Type 2 QSO
An infrared-selected, narrow-line QSO has been found to exhibit an
extraordinarily broad Halpha emission line in polarized light. Both the extreme
width (35,000 km/sec full-width at zero intensity) and 3,000 km/sec redshift of
the line centroid with respect to the systemic velocity suggest emission in a
deep gravitational potential. An extremely red polarized continuum and partial
scattering of the narrow lines at a position angle common to the broad-line
emission imply extensive obscuration, with few unimpeded lines of sight to the
nucleus.Comment: 4 pages, 1 figure, to appear in the Astrophysical Journal Letter
Position Sensing for Rotor in Hybrid Stepper Motor
A method and system are provided for sensing the position of a rotor in a hybrid stepper motor. First and second Hall sensors are positioned in a spaced-apart relationship with the first and second armatures of the rotor such that the first and second Hall sensors generate electrical outputs that are 90.degree. out of phase with one another as the rotor rotates. The electrical outputs are adjusted relative to a reference, and the amplitude of the electrical outputs is further adjusted to account for spacing differences between the rotor and each of the first and second Hall sensors
Miniature housing with standard addressable interface for smart sensors and drive electronics
A miniature assembly is disclosed which includes a housing assembly with a cover configured to be sealably secured to a box-like receptacle. The receptacle comprises openings on opposing sides for the seating therein of communications connectors. Enclosed within housing is custom-sized circuit board for supporting, at least, a standard communications interface and at least one electronic device
System providing limit switch function with simultaneous absolute position output
A limit and position sensing system includes a sensor assembly and an emitter. The sensor assembly includes first and second electrical conductors arranged in opposing parallel planes. The first electrical conductor is coiled outwardly from either end thereof in a clockwise fashion to form a first coil region and a second coil region. The second electrical conductor forms a single coil with portions of the single coil's rings lying between the first end and second end of the first electrical conductor being parallel to an axis of the first electrical conductor's plane. Ferromagnetic material is aligned with the first and second electrical conductors and spans beyond (a) the first and second ends of the first electrical conductor, and (b) the portions of the rings of the second electrical conductor's single coil that lie between the first end and second end of the first electrical conductor. The emitter is spaced apart from the sensor assembly and transmits a periodic electromagnetic wave towards the sensor assembly
The Composition of Inorganic Colloids Extracted from Three Iowa Soils
The purpose of this work was to determine the colloidal content of certain soils and to make analyses of the inorganic colloids extracted from these soils. These soils ranging from a pH of 5.53 to a pH of 7.60 were obtained and the total colloidal content determined. The inorganic colloids were then extracted according to Truog and Drosdorff\u27s procedure (2) and analyzed for total SiO2 , Al2O3 , Fe2O3 , TiO2 , P2O5 and available K2O. The total SiO2, Fe2O3, Al2O3 and TiO2 were determined by Hillebrand\u27s method (1). The phosphorus content was determined by the magnesium nitrate method. The available K2O was determined by the Aspergillus niger method
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