18 research outputs found
Evaluating and predicting agricultural management effects under tile drainage using modified APSIM
Measurement of the Positive Muon Anomalous Magnetic Moment to 0.46 ppm
We present the first results of the Fermilab Muon g-2 Experiment for the
positive muon magnetic anomaly . The anomaly is
determined from the precision measurements of two angular frequencies.
Intensity variation of high-energy positrons from muon decays directly encodes
the difference frequency between the spin-precession and cyclotron
frequencies for polarized muons in a magnetic storage ring. The storage ring
magnetic field is measured using nuclear magnetic resonance probes calibrated
in terms of the equivalent proton spin precession frequency
in a spherical water sample at 34.7C. The
ratio , together with known fundamental
constants, determines
(0.46\,ppm). The result is 3.3 standard deviations greater than the standard
model prediction and is in excellent agreement with the previous Brookhaven
National Laboratory (BNL) E821 measurement. After combination with previous
measurements of both and , the new experimental average of
(0.35\,ppm) increases the
tension between experiment and theory to 4.2 standard deviationsComment: 10 pages; 4 figure
The Fluoretec system for rapid diagnosis of bacteroides infections by direct immunofluorescence of clinical specimens.
Corn stover harvest N and energy budgets in central Iowa.
Harvesting corn stover removes N from the fields, but its effect on subsurface drainage and other N losses is uncertain. We used the Root Zone Water Quality Model (RZWQM) to examine N losses with 0 (NRR) or 50% (RR) corn residue removal within a corn and soybean rotation over a 10-yr period. In general, all simulations used the same pre-plant or post-emergence N fertilizer rate (200âŻkgâŻhaâ1âŻyrâ1). Simulated annual corn yields averaged 10.7âŻMgâŻhaâ1 for the post emergence applications (NRRpost and RRpost), and 9.5 and 9.4âŻMgâŻhaâ1âŻyrâ1 for NRRpre and RRpre. Average total N input during corn years was 19.3âŻkgâŻNâŻhaâ1 greater for NRRpre compared to RRpre due to additional N in surface residues, but drainage N loss was only 1.1âŻkgâŻNâŻhaâ1âŻyrâ1 greater for NRRpre. Post-emergence N application with no residue removal (NRRpost) reduced average drainage N loss by 16.5âŻkgâŻhaâ1âŻyrâ1 compared to pre-plant N fertilization (NRRpre). The farm-gate net energy ratio was greatest for RRpost and lowest for NRRpre (14.1 and 10.4âŻMJ output per MJ input) while greenhouse gas intensity was lowest for RRpost and highest for NRRpre (11.7 and 17.3âŻg CO2-eq.âŻMJâ1 output). Similar to published studies, the simulations showed little difference in N2O emissions between scenarios, decreased microbial immobilization for RR compared to NRR, and small soil carbon changes over the 10-yr simulation. In contrast to several previous modeling studies, the crop yield and N lost to drain flow were nearly the same between NRR and RR without supplemental N applied to replace N removed with corn stover. These results are important to optimizing the energy and nitrogen budgets associated with corn stover harvest and for developing a sustainable bioenergy industry.This article is published as Malone, R. W., S. Herbstritt, L. Ma, T. L. Richard, R. Cibin, P. W. Gassman, H. H. Zhang et al. "Corn stover harvest N and energy budgets in central Iowa." Science of the Total Environment 663 (2019): 776-792. DOI: 0.1016/j.scitotenv.2019.01.328. Works produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S. The content of this document is not copyrighted