3,180 research outputs found
Rotationally resolved collisional transfer rates in OH
Fluorescence lidar measurements of the hydroxyl radical require detailed information concerning collision induced processes in order to deduce the radical number density from a lidar return. The Goddard SFC OH lidar currently utilizes a broadband detector which precludes the necessity of fully understanding collisional redistribution of rotational energy within the excited state. Numerous advantages result however from the inclusion of a detector with a bandpass only slightly larger that the Doppler width of a rotational line. This however places more stringent requirements on the spectroscopy. Measurements were accordingly made of rotationally resolved quenching rates for collisions with O2, N2, and H2O. Rotational transfer rates were also measured for the same colliders. Quenching rates were measured using a Nd-YAG pumped Rh6G dye laser doubled into the UV. The OH lifetimes were measured as a function of pressure of quenching gas at total pressures of between 50 and 250 microns. Rotational transfer rates were measured by recording the emission spectrum on an intensified diode array and integrating over 10.000 laser shots
Soybean Seed Production
Maximum soybean production relies upon uniform and rapid stand establishment. Meeting these criteria requires an adequate supply of high quality seed. Providing the necessary seed supply has become the responsibility of the professional seedsmen. The ultimate quality of seed produced is defined by the genotype and the environment under which it is produced. Initially, soybean breeding programs emphasized yield and other agronomic traits with little concern for seed quality. Although to a large extent that is still true, there is a growing appreciation for the importance of seed quality
Seed Coatings to Improve Seed Performance, Reduce Pesticide Usage and as Production Tools in Soybeans and Corn
For hundreds if not thousands of years seeds have been amended with various materials to insure their survival or to improve their emergence and growth. The early Greeks and Egyptians used salts to insure seed storability and applied elemental dusts to protect the seed after it was planted. Although hot water treatments might not be considered a seed treatment they have the effect of eliminating harmful organisms while maintaining seed viability. With the discovery of the pesticidal properties of some of the heavy metals especially copper, mercury and zinc modem seed treatment as we know it today was introduced
Laboratory spectroscopy in support of atmospheric measurements
Optical measurements of trace species in the atmosphere require precise, accurate spectroscopic data for the molecules under study. This laboratory exits to provide high quality spectroscopic data for the interpretation of data from existing satellite, balloon, ground, and aircraft instruments, as well as to provide sufficient data to assess the feasibility of new instruments
Ground-based lidar measurements of stratospheric ozone. The NASA/GSFC stratospheric ozone lidar trailer experiment STROZ LITE
The major research objective is the measurement of high precision vertical profiles of ozone between 20-40 kilometers. The precision is such that the instrument should be capable of detecting a small trend (on the order of less that 1 percent per year) over a 5-10 year period. Temperature was measured between 30 and 365 km. The Goddard Space Flight Center (GSFC) mobile lidar was installed at Table Mountain and a comparison between it and the permanent Jet Propulsion Laboratory (JPL) lidar was made over the course of about 3 weeks. The lidars agreed very well between 20 and 40 km, and under certain conditions up to 45-47 km. There were several anomalies that both lidars followed very well. Agreement with Rocket Ozonesonde (ROCOZ) and electrochemical concentration cell (ECC) sondes was also very good
Debris and micrometeorite impact measurements in the laboratory
A method was developed to simulate space debris in the laboratory. This method, which is an outgrowth of research in inertial confinement fusion (ICF), uses laser ablation to accelerate material. Using this method, single 60 micron aluminum spheres were accelerated to 15 km/sec and larger 500 micron aluminum spheres were accelerated to 2 km/sec. Also, many small (less than 10 micron diameter) irregularly shaped particles were accelerated to speeds of 100 km/sec
Taking Another Look: Light n-Capture Element Abundances in Metal-Poor Halo Stars
Elements are produced in stars through a variety of processes; some are well known, others are still the object of active research. The elements Zirconium (Zr) and Yttrium (Y) are produced via neutron capture (ncapture). These elements reside in the mass range where there is uncertainty about the production mechanism at early time. The rapid n-capture process (r-process) was believed to be responsible for the production, but no study (Burris et al 2000, Gilroy et al 1988 and others) has been able to successfully use the r-process to reproduce the abundance signature for elements in this mass range for metal-poor halo stars. It has been suggested (Sneden and Cowan 2003) that there may be an undiscovered component to the rprocess. New abundance calculations for these elements have been conducted for a sample of metalpoor halo stars. Transition probabilities for Zr II from (Malcheva et al.2006) and for YII from (Hannaford et al.1982) were utilized in these calculations as well as new high quality observational data from the Keck telescope. The new laboratory and observational data resulted in improvement in the abundance determinations and uncertainty of the abundances
Come After Breakfast : Bring \u27Long Your Lunch And Leave \u27Fore Supper Time.
https://digitalcommons.library.umaine.edu/mmb-vp/1235/thumbnail.jp
Parameterized Littlewood-Paley operators with variable kernels on Hardy spaces and weak Hardy spaces
In this paper, by using the atomic decomposition theory of Hardy space and
weak Hardy space, we discuss the boundedness of parameterized Littlewood-Paley
operator with variable kernel on these spaces.Comment: 15 pages. arXiv admin note: text overlap with arXiv:1711.0961
- …