63,188 research outputs found
Emissions data by category of engines
Exhaust gas pollutant emissions data under test stand conditions were obtained for the following: (1) full-rich baseline test (7-mode cycle), (2) lean-out tests for each power mode, and (3) different spark settings. The test data were also used to create a theoretical 5-mode cycle baseline. The emissions data in the framework of the theoretical 5-mode cycle were emphasized. There is no significant difference in the test results produced by data exhibited on the 7-mode cycle or 5-mode cycle. The 5-mode cycle was slightly more conservative for the carbon monoxide pollutant than the 7-mode cycle. The data were evaluated to determine which mode(s) had the greatest influence on improving general aviation piston engine emissions. Improvements that were achieved as a result of making lean-out adjustments to the fuel metering device were: (1) taxi mode only, (2) taxi and approach modes combined, and (3) leaning-out of the climb mode to best power
Comparison of the INRIM and PTB lattice-spacing standards
To base the kilogram definition on the atomic mass of the silicon 28 atom,
the present relative uncertainty of the silicon 28 lattice parameter must
lowered to 3E-9. To achieve this goal, a new experimental apparatus capable of
a centimetre measurement-baseline has been made at the INRIM. The comparison
between the determinations of the lattice parameter of crystals MO*4 of INRIM
and WASO4.2a of PTB is intended to verify the measurement capabilities and to
assess the limits of this experiment.Comment: 10 pages, 8 figures, submitted to Metrologi
Energy Model of Networks-on-Chip and a Bus
A Network-on-Chip (NoC) is an energy-efficient onchip communication architecture for Multi-Processor Systemon-Chip (MPSoC) architectures. In earlier papers we proposed two Network-on-Chip architectures based on packet-switching and circuit-switching. In this paper we derive an energy model for both NoC architectures to predict their energy consumption per transported bit. Both architectures are also compared with a traditional bus architecture. The energy model is primarily needed to find a near optimal run-time mapping (from an energy point of view) of inter-process communication to NoC link
The hydrogen atom in electric and magnetic fields : Pauli's 1926 article
The results obtained by Pauli, in his 1926 article on the hydrogen atom, made
essential use of the dynamical so(4) symmetry of the bound states. Pauli used
this symmetry to compute the perturbed energy levels of an hydrogen atom in a
uniform electric field (Stark effect) and in uniform electric and magnetic
fields. Although the experimental check of the single Stark effect on the
hydrogen atom has been studied experimentally, Pauli's results in mixed fields
have been studied only for Rydberg states of rubidium atoms in crossedfields
and lithium atoms in parallel fields.Comment: 11 pages, latex file, 2 figure
trackr: A Framework for Enhancing Discoverability and Reproducibility of Data Visualizations and Other Artifacts in R
Research is an incremental, iterative process, with new results relying and
building upon previous ones. Scientists need to find, retrieve, understand, and
verify results in order to confidently extend them, even when the results are
their own. We present the trackr framework for organizing, automatically
annotating, discovering, and retrieving results. We identify sources of
automatically extractable metadata for computational results, and we define an
extensible system for organizing, annotating, and searching for results based
on these and other metadata. We present an open-source implementation of these
concepts for plots, computational artifacts, and woven dynamic reports
generated in the R statistical computing language
Development of non-linear finite element computer code
Recent work has shown that the use of separable symmetric functions of the principal stretches can adequately describe the response of certain propellant materials and, further, that a data reduction scheme gives a convenient way of obtaining the values of the functions from experimental data. Based on representation of the energy, a computational scheme was developed that allows finite element analysis of boundary value problems of arbitrary shape and loading. The computational procedure was implemental in a three-dimensional finite element code, TEXLESP-S, which is documented herein
- âŠ