415 research outputs found
Identifying Forage Quality Eastern Gamagrass [\u3ci\u3eTripsacum dactyloides\u3c/i\u3e (L.) L.] Genotypes from a Wild Regional Collection
Eastern gamagrass is a perennial warm-season grass native to North America and endemic to the eastern United States. The species is highly valuable as both a forage and hay crop. In 2012, 171 wild-type eastern gamagrass accessions were collected from the southeast, mid-Atlantic and Atlantic coast regions. Each accession was relocated to Starkville, MS (33.423585, -88.792394) and established in a long-term nursery. Accessions were analyzed for ploidy level and during 2013-2014 were further evaluated for desirable forage characteristics including: cold tolerance, delayed maturity, rust resistance, and digestibility. Fourteen elite individuals were identified from the original collection and were propagated for further research. Elite genotypes were divided into individual proaxes and transplanted into a RCB design with three replications. Plots measured 3.04 m x 1.21 m with five replicate plants evenly spaced within the plot. Following a one-year establishment period, whole plots were harvested on a 28-day cycle from May to October. Plots were harvested to a 15 cm stubble height with a Wintersteiger Cibus S harvester. Following each harvest, nitrogen fertilizer was applied to all plots at 56 kg N ha-1 using urea ammonium sulfate (32-0-0-12S). Homogenized subsamples were taken to determine percent dry matter, neutral detergent fiber (NDF), acid detergent fiber (ADF), and in-vitro dry matter digestibility (IVDMD). The commercial cultivar ‘Highlander’, was included in the study as a check. Seasonal yields ranged from 1.19 - 2.73 Mg ha-1. Three accessions – originally collected in Alabama and North Carolina – produced significantly greater forage yield than the check (P \u3e 0.0001). Digestibility of the commercial check as well as one accession – collected in Tennessee – were significantly greater than all other accessions (P \u3e 0.0001)
Phenotypic Evaluation of Energycane Varieties for Bioenergy
The need for renewable and carbon-neutral energy is growing as fossil fuel supplies decrease and concerns of climate change increase. C4 grasses are among the most efficient carbon accumulators. Sugarcane (Saccharum officinarum) is a renewable bioenergy crop with low inputs and high yields, but it is limited to tropical and sub-tropical climates. A close relative, Saccharum spontaneum, readily hybridizes with S. officinarum. S. spontaneum lends cold tolerance and higher yields to the hybrid progeny, called energycane. The Sugarcane Breeding Unit (USDA, Houma, Louisiana, USA) selected twenty-six genotypes for testing at Mississippi State University to determine production and cold tolerance at latitude 33.4552° N. Twenty of these genotypes were chosen after the first year for further testing against an energycane check (Ho02-113) and a sugarcane check (L01-299). Seed cane were harvested and planted in the fall of 2019 and 2020 in randomized complete block design with four replications. Plots were 6.1 x 1.8 m, fertilized once at a rate of 168 kg N ha-1. Cane heights and stand counts were collected to monitor genotype growth. At the end of the season, canes were taken for fresh weight, dry weight, °Brix, and sap volume. End of season characteristics of first year growth were: Mean height ranged from 73 to 204 cm; cane number ranged from 9,530 to 68,171 canes ha-1. Plot fresh weights ranged from: 19.9 to 61 Mg ha-1. Mean value of °Brix ranged from 8.9 to 13.7. Mean extractable sap volume ranged from: 2311 to 16,821 L ha-1. Theoretical ethanol yield was calculated for sap and from dry matter. Total theoretical ethanol yield ranged from 939.8 to 3261.2 L ha-1
Cost effectiveness of alternative planned places of birth in woman at low risk of complications: evidence from the Birthplace in England national prospective cohort study
Objectives To estimate the cost effectiveness of alternative planned places of birth
Course-based Science Research Promotes Learning in Diverse Students at Diverse Institutions
Course-based research experiences (CREs) are powerful strategies for spreading learning and improving persistence for all students, both science majors and nonscience majors. Here we address the crucial components of CREs (context, discovery, ownership, iteration, communication, presentation) found across a broad range of such courses at a variety of academic institutions. We also address how the design of a CRE should vary according to the background of student participants; no single CRE format is perfect. We provide a framework for implementing CREs across multiple institutional types and several disciplines throughout the typical four years of undergraduate work, designed to a variety of student backgrounds. Our experiences implementing CREs also provide guidance on overcoming barriers to their implementation
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Indoor air quality measurements in energy efficient buildings
The Energy Efficient Buildings Program of the Lawrence Berkeley Laboratory (LBL) has designed and fabricated a mobile laboratory for research and development studies of ventilation requirements and energy utilization in residential and commercial buildings. The Energy Efficient Buildings (EEB) Mobile Laboratory is used in studies of indoor air quality in buildings before and after energy conservation retrofits and in new buildings incorporating energy efficient designs. Indoor air quality measurements have been conducted in residential buildings and work in progress includes indoor air quality monitoring in schools, hospitals, and energy efficient residential buildings. The monitoring program includes measurement of CO, CO/sub 2/, SO/sub 2/, NO, NO/sub 2/, O/sub 3/, infiltration rate (tracer gas technique), and aerosol size distribution on a continuous basis. Total and respirable-fraction particulate samples are collected on membrane filter media for analysis by x-ray fluorescence (XRFA), photoelectron spectroscopy (ESCA), proton activation analysis (PAA), combustion, and wet-chemistry techniques for the determination of particulate elemental composition (S, N, C, etc.) and ionic species such as SO/sub 4//sup 2 -/, NO/sub 3//sup -/, and NH/sub 4//sup +/. Results of the initial phases of this program indicate that the concentrations of some gaseous and respirable particulate air pollutants in specific indoor environments exceed those levels commonly found in the outdoor urban air environment
Use of PDV to measure the overdriven products equation of state in PBX 9502 and PBX 9501 and the EOS in shocked foams
Author Institution: Los Alamos National LaboratorySlides presented at the 2014 Photonic Doppler Velocimetry (PDV) Workshop Hosted by National Security Technologies, LLC, and the University of Nevada Las Vegas, June 24-26, 2014, Las Vegas, Nevada
Effect of Nuclear Quadrupole Interaction on the Relaxation in Amorphous Solids
Recently it has been experimentally demonstrated that certain glasses display
an unexpected magnetic field dependence of the dielectric constant. In
particular, the echo technique experiments have shown that the echo amplitude
depends on the magnetic field. The analysis of these experiments results in the
conclusion that the effect seems to be related to the nuclear degrees of
freedom of tunneling systems. The interactions of a nuclear quadrupole
electrical moment with the crystal field and of a nuclear magnetic moment with
magnetic field transform the two-level tunneling systems inherent in amorphous
dielectrics into many-level tunneling systems. The fact that these features
show up at temperatures , where the properties of amorphous materials
are governed by the long-range interaction between tunneling systems,
suggests that this interaction is responsible for the magnetic field dependent
relaxation. We have developed a theory of many-body relaxation in an ensemble
of interacting many-level tunneling systems and show that the relaxation rate
is controlled by the magnetic field. The results obtained correlate with the
available experimental data. Our approach strongly supports the idea that the
nuclear quadrupole interaction is just the key for understanding the unusual
behavior of glasses in a magnetic field.Comment: 18 pages, 9 figure
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Building Energy Use Compilation·and Analysis (BECA) An International Comparison and Critical Review. Part A: New Residential Buildings
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