1,363 research outputs found
Linear differential pressure sensor Patent
Design and development of pressure sensor for measuring differential pressures of few pounds per square inc
Aharonov-Bohm cages in the GaAlAs/GaAs system
Aharonov-Bohm oscillations have been observed in a lattice formed by a two
dimensional rhombus tiling. This observation is in good agreement with a recent
theoretical calculation of the energy spectrum of this so-called T3 lattice. We
have investigated the low temperature magnetotransport of the T3 lattice
realized in the GaAlAs/GaAs system. Using an additional electrostatic gate, we
have studied the influence of the channel number on the oscillations amplitude.
Finally, the role of the disorder on the strength of the localization is
theoretically discussed.Comment: 6 pages, 11 EPS figure
INFORMATION TECHNOLOGIES AND THE DESIGN AND ANALYSIS OF SITE-SPECIFIC EXPERIMENTS WITHIN COMMERCIAL COTTON FIELDS
Information products derived from multi-spectral remote sensing images, LIDAR elevations, or data products from other sensor systems (soil electrical conductivity measurements, yield monitors, etc.) characterize potential crop productivity by mapping biophysical aspects of cropland variability. These sensor systems provide spectral, spatial, and temporal measurements at resolutions and accuracies describing the variability of in-field, physical characteristic phenomena, including management practices from cropland preparation, selection of crop cultivars, and variable-rate applications of inputs. In addition, DGPS-equipped (differential, global positioning system) harvesters monitor yield response at closely spaced, georeferenced points. Geographic information system and image processing techniques fuse diverse information sources to spatially characterize cropland, describe management practices, and quantify the variable yield response. Following fusion of information sources, effectiveness of spatially applied management practices may be evaluated by designed experiments assessing impacts on yield caused by geo-referenced relationships between (1) uncontrollable spatial components (the environment) and (2) controllable management practices (cultivar selection, fertility management, herbicide, insecticide, and plant growth regulator applications, etc.). These kinds of experiments can be designed because farming equipment can be computer controlled through DGPS giving farmers the ability to continuously change applied treatments for many farming operations. A mixed linear model involving both uncontrollable and controllable management attributes attached as spatial descriptors to yield monitor points evaluates effects of management practices on yield. An example based upon cotton production demonstrates the methodology. Additional strategies for designing studies in commercial cotton fields involving spatial information are discussed
A methodology for boost-glide transport technology planning
A systematic procedure is presented by which the relative economic value of technology factors affecting design, configuration, and operation of boost-glide transport can be evaluated. Use of the methodology results in identification of first-order economic gains potentially achievable by projected advances in each of the definable, hypersonic technologies. Starting with a baseline vehicle, the formulas, procedures and forms which are integral parts of this methodology are developed. A demonstration of the methodology is presented for one specific boost-glide system
Design Considerations for Efficient and Effective Microarray Studies
This paper describes the theoretical and practical issues in experimental design for gene expression microarrays. Specifically, this paper (1) discusses the basic principles of design (randomization, replication, and blocking) as they pertain to microarrays, and (2) provides some general guidelines for statisticians designing microarray studies
THE POWER OF STRUCTURED DESIGNS AND MIXED MODELS IN A REAL WORLD EXPERIMENT
Justifications usually given for adopting an automated system pertain to a reduction in labor and an improvement in quality control. A manufacturer of a prototype instrument that automated some of the steps for culturing bacteria wanted to compare the automated system to the manual system. The manufacturer wanted to compare the two systems in 1) Total time needed to isolate the target bacteria, 2) Ability to isolate the target bacteria, 3) Amount of interference from background (non-target) bacterial growth, and 1) Extent of cross (sample to sample) contamination.
This paper presents the experimental design used to make these comparisons and how the design helped discover some surprising results about laboratory quality control. The experiment presented illustrates the importance of a good experimental design, the power of current statistical tools, and that a thorough and appropriate analysis of a data set requires side-by-side good detective work by both statistician and client
Searches for New Quarks and Leptons Produced in Z-Boson Decay
We have searched for events with new-particle topologies in 390 hadronic Z decays with the Mark II detector at the SLAC Linear Collider. We place 95%-confidence-level lower limits of 40.7 GeV/c^2 for the top-quark mass, 42.0 GeV/c^2 for the mass of a fourth-generation charge - 1/3 quark, and 41.3 GeV/c^2 for the mass of an unstable Dirac neutral lepton
Measurement of Z Decays into Lepton Pairs
We present measurements by the Mark II experiment of the ratios of the leptonic partial widths of the Z boson to the hadronic partial width. The results are Γ_(ee)/Γ_(had)=0.037_(-0.012^()+0.016),Γ_(µµ)/Γ_(had)=0.053-_(0.015)^(+0.020), and Γ_(ττ)/Γ_(had)=0.066_(-0.017)^(+0.021), in good agreement with the standard-model prediction of 0.048. From the average leptonic width result, Γ_(ll)/Γ_(had)=0.053_(-0.009)^(+0.010), we derive Γ_(had)=1.56_(-0.24)^(+0.28) GeV. We find for the vector coupling constants of the tau and muon v_τ^2=0.31±0.31_(-0.30)^(+0.43) and v_μ^2=0.05±0.30_(-0.23)^(+0.34)
QHE of Bilayer Systems in the Presence of Tunneling -- case --
Transport properties of bilayer quantum Hall systems at , where
is an odd integer, are investigated. The edge theory is used for the
investigation, since tunneling between the two layers is assumed to occur on
the edge of the sample because of the bulk incompressibility. It is shown that
in the case of the independent Laughlin state tunneling is irrelevant when
in the low temperature and long wave length limit. The temperature
dependence of two-terminal conductance of the system in which only one of the
two layers is contacted with electrode is discussed.Comment: 5 page
Dynamics of Dissipative Quantum Hall Edges
We examine the influence of the edge electronic density profile and of
dissipation on edge magnetoplasmons in the quantum Hall regime, in a
semiclassical calculation. The equilibrium electron density on the edge,
obtained using a Thomas-Fermi approach, has incompressible stripes produced by
energy gaps responsible for the quantum Hall effect. We find that these stripes
have an unobservably small effect on the edge magnetoplasmons. But dissipation,
included phenomenologically in the local conductivity, proves to produce
significant oscillations in the strength and speed of edge magnetoplasmons in
the quantum Hall regime.Comment: 23 pages including 10 figure
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