8,612 research outputs found

    Conservation Reserve Program Hay Quality from Producer Submissions to a Commercial Laboratory in Central Nebraska

    Get PDF
    The Conservation Reserve Program (CRP) sets aside hectares to be permanent grassland and keeps those acres out of rotation for agricultural use. In drought conditions, these acres open to emergency haying and grazing. CRP hay is harvested at the end of the primary nesting season, mid to late summer, therefore this is a very mature product for stored forage. Many beef cow producers in the Midwest feed CRP hay in the last third of gestation until cattle can be turned out for spring grazing. Data was obtained from CRP hay samples to evaluate forage nutritive value and supplementation needs relative to gestating beef cow requirements. Crude protein, ADF, aNDF, and NDFD48 ranges and means all indicated that overall CRP hay forage quality is poor. In fact, 90.07% (n = 508) of the samples would require producers feeding gestating beef cows to provide extra supplementation based on crude protein, TDN, or both. These results show that if beef producers must feed CRP hay, then laboratory analysis will be a valuable tool for determining the precise level of supplementation required to meet beef cow nutritional requirements. However, these results paired with recent wildlife management studies show that grazing at reduced stocking rates during nesting season may be the best alternative to optimize forage quality utilization on CRP acres as well as provide the benefit of more variable grassland habitat to increase avian species diversity on these lands

    Collaborative applications used in a wireless environment at sea for use in Coast Guard Law Enforcement and Homeland Security missions

    Get PDF
    This thesis analyzes the potential impact of incorporating wireless technologies, specifically an 802.11 mesh layer architecture and 802.16 Orthogonal Frequency Division Multiplexing, in order to effectively and more efficiently transmit data and create a symbiotic operational picture between Coast Guard Cutters, their boarding teams, Coast Guard Operation Centers, and various external agencies. Two distinct collaborative software programs, Groove Virtual Office and the Naval Postgraduate School's Situational Awareness Agent, are utilized over the Tactical Mesh and OFDM network configurations to improve the Common Operating Picture of involved units within a marine environment to evaluate their potential impact for the Coast Guard. This is being done to increase the effectiveness and efficiency of Coast Guard units while they carry out their Law Enforcement and Homeland Security Missions. Through multiple field experiments, including Tactical Network Topology and nuclear component sensing with Lawrence Livermore National Laboratory, we utilize commercial off the shelf (COTS) equipment and software to evaluate their impact on these missions.http://archive.org/details/collaborativeppl109452311Lieutenant Commander, United States Coast GuardLieutenant, United States Coast GuardApproved for public release; distribution is unlimited

    Structural phase transitions of vortex matter in an optical lattice

    Full text link
    We consider the vortex structure of a rapidly rotating trapped atomic Bose-Einstein condensate in the presence of a co-rotating periodic optical lattice potential. We observe a rich variety of structural phases which reflect the interplay of the vortex-vortex and vortex-lattice interactions. The lattice structure is very sensitive to the ratio of vortices to pinning sites and we observe structural phase transitions and domain formation as this ratio is varied.Comment: 4 pages, 3 figure

    Accuracy and Precision of Near Infra-red Spectroscopy (NIRS) versus Wet Chemistry in Forage Analysis

    Get PDF
    Near Infra-red Spectroscopy (NIRS) is an attractive option for forage analysis. NIRS is less labor intensive, nondestructive, rapid, environmentally friendly and provides accurate and precise results. However, many nutritionists are quick to brush off NIRS, citing ‘poor accuracy’. We evaluated the accuracy and precision of dry matter (DM), crude protein (CP), acid detergent fiber (ADF), and neutral detergent fiber (NDF) of 33 National Forage Testing Association (NFTA) proficiency test (PT) alfalfa hay samples analyzed by NIRS in 7 NIRS Forage and Feed Testing Consortium (NIRSC) member laboratories. The reference method averages (RMA), used to evaluate the NIRS results, were based on the wet chemistry results reported by numerous laboratories participating in the corresponding NFTA proficiency testing rounds. Thus, this study is a robust comparison of NIRS determined results with the corresponding wet chemistry results, which is still a “gold standard” to many nutritionists. These results demonstrate that when NIRS calibrations are developed using good science and applied properly, NIRS is as accurate as wet chemistry in forage nutritional analysis. Further, both intra-laboratory and inter-laboratory precision of NIRS methods are superior to wet chemistry method

    Origin of Rashba-splitting in the quantized subbands at Bi2Se3 surface

    Full text link
    We study the band structure of the Bi2Se3\text{Bi}_2\text{Se}_3 topological insulator (111) surface using angle-resolved photoemission spectroscopy. We examine the situation where two sets of quantized subbands exhibiting different Rashba spin-splitting are created via bending of the conduction (CB) and the valence (VB) bands at the surface. While the CB subbands are strongly Rashba spin-split, the VB subbands do not exhibit clear spin-splitting. We find that CB and VB experience similar band bending magnitudes, which means, a spin-splitting discrepancy due to different surface potential gradients can be excluded. On the other hand, by comparing the experimental band structure to first principles LMTO band structure calculations, we find that the strongly spin-orbit coupled Bi 6pp orbitals dominate the orbital character of CB, whereas their admixture to VB is rather small. The spin-splitting discrepancy is, therefore, traced back to the difference in spin-orbit coupling between CB and VB in the respective subbands' regions

    Electronic structure of the (111) and (-1-1-1) surfaces of cubic BN: A local-density-functional ab initio study

    Full text link
    We present ab initio local-density-functional electronic structure calculations for the (111) and (-1-1-1) surfaces of cubic BN. The energetically stable reconstructions, namely the N adatom, N3 triangle models on the (111), the (2x1), boron and nitrogen triangle patterns on the (-1-1-1) surface are investigated. Band structure and properties of the surface states are discussed in detail.Comment: 8 pages, 12 figure

    A 727/JT8D-100 series engine exhaust system propulsion performance model test

    Get PDF
    The results are presented from testing one-eighth scale models of the Pratt and Whitney aircraft reference and Boeing nozzles for the JT8D-100 series mixed flow engines. The objective of the test was to obtain the nozzle velocity and flow coefficients for the reference configurations and compare these with the Boeing configurations which incorporated a longer splitter between the fan and primary flows. A further comparison was made between the JT8D-100 series nozzles and the Boeing JT8D-9/727 production nozzle performance. A statistical analysis was used to compare configurations which showed the performance (velocity coefficient) of the reference and the Boeing configuration was the same for the JT8D-109. It also showed no difference between reference and the Boeing configuration for the JT8D-115 and no difference for the JT8D-117 nozzles. Bypass ratio (match) was shown to be equally dependent on splitter position as on nozzle area within the range investigated. The nozzles were very similar in flow coefficient within an engine family. Excellent profile data was recorded. The effects of swirl on the nozzle performance was examined and found to degrade the velocity and flow coefficients
    corecore