2,236 research outputs found

    Soybean Seed Production

    Get PDF
    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

    Get PDF
    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

    Get PDF
    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

    Get PDF
    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

    In Situ Characterisation of Permanent Magnetic Quadrupoles for focussing proton beams

    Full text link
    High intensity laser driven proton beams are at present receiving much attention. The reasons for this are many but high on the list is the potential to produce compact accelerators. However two of the limitations of this technology is that unlike conventional nuclear RF accelerators lasers produce diverging beams with an exponential energy distribution. A number of different approaches have been attempted to monochromise these beams but it has become obvious that magnetic spectrometer technology developed over many years by nuclear physicists to transport and focus proton beams could play an important role for this purpose. This paper deals with the design and characterisation of a magnetic quadrupole system which will attempt to focus and transport laser-accelerated proton beams.Comment: 20 pages, 42 figure

    Seed enhancements

    Get PDF
    Seed enhancements may be defined as post-harvest treatments that improve germination or seedling growth, or facilitate the delivery of seeds and other materials required at the time of sowing. This definition includes three general areas of enhancements: pre-sowing hydration treatments (priming), coating technologies and seed conditioning. Pre-sowing hydration treatments include non-controlled water uptake systems (methods in which water is freely available and not restricted by the environment) and controlled systems (methods that regulate seed moisture content preventing the completion of germination). Three techniques are used for controlled water uptake: priming with solutions or with solid particulate systems or by controlled hydration with water. These priming techniques will be discussed in this paper with reference to methodology, protocol optimization, drying and storage. Coating technologies include pelleting and film coating, and coatings may serve as delivery systems. Seed conditioning equipment upgrades seed quality by physical criteria. Integration of these methods can be performed, and a system is described to upgrade seed quality in Brassica that combines hydration, coating and conditioning. Upgrading is achieved by detecting sinapine leakage from nonviable seeds in a coating material surrounding the seeds. Seed-coat permeability directly influences leakage rate, and seeds of many species have a semipermeable layer. The semipermeable layer restricts solute diffusion through the seed coat, while water movement is not impeded. Opportunities for future seed enhancement research and development are highlighte

    The algebra of adjacency patterns: Rees matrix semigroups with reversion

    Full text link
    We establish a surprisingly close relationship between universal Horn classes of directed graphs and varieties generated by so-called adjacency semigroups which are Rees matrix semigroups over the trivial group with the unary operation of reversion. In particular, the lattice of subvarieties of the variety generated by adjacency semigroups that are regular unary semigroups is essentially the same as the lattice of universal Horn classes of reflexive directed graphs. A number of examples follow, including a limit variety of regular unary semigroups and finite unary semigroups with NP-hard variety membership problems.Comment: 30 pages, 9 figure

    Hot dense capsule implosion cores produced by z-pinch dynamic hohlraum radiation

    Full text link
    Hot dense capsule implosions driven by z-pinch x-rays have been measured for the first time. A ~220 eV dynamic hohlraum imploded 1.7-2.1 mm diameter gas-filled CH capsules which absorbed up to ~20 kJ of x-rays. Argon tracer atom spectra were used to measure the Te~ 1keV electron temperature and the ne ~ 1-4 x10^23 cm-3 electron density. Spectra from multiple directions provide core symmetry estimates. Computer simulations agree well with the peak compression values of Te, ne, and symmetry, indicating reasonable understanding of the hohlraum and implosion physics.Comment: submitted to Phys. Rev. Let

    The equational theories of representable residuated semigroups

    Get PDF
    We show that the equational theory of representable lower semilattice-ordered residuated semigroups is finitely based. We survey related results
    corecore