1,884 research outputs found
Low cost shop floor DNC system : a dissertation presented in partial fulfilment of the requirements for the postgraduate Masters of Technology in Automation & Control at Massey University
Direct/Distributed Numerical Control (DNC) has a vital role in delivering a successful Computer Integrated Manufacturing (CIM) strategy. DNC is the most popular form of factory automation system in the shop floor environment. Its core function is to enable manufacturing information to flow smoothly and efficiently to and from the shop floor facilities. The current New Zealand small to medium manufacturers are unwilling to make large financial investment in the more expensive packages, and hence, there is a need for a cost effective DNC application software within this sector of the industry. The research conducted for this project focuses on the application of a multiport serial card, and the development of a low cost DNC application software that can be implemented in the small to medium size companies for transferring data and other manufacturing data such as drawing files, and computerised numerical control (CNC) programs. In addition, the research also looks at methods to allow remote access to the system through the World Wide Web (WWW). In order to achieve the objectives mentioned above, a powerful and user-friendly user interface programming tool kit — Borland's Delphi 4 was adopted as the key development tool. Delphi 4 is a Rapid Application Development (RAD) package that is fully compatible to the Multiport's senal programming library, and majority of the Microsoft's remote access technology such as Object Linking and Embedding technology (OLE) or ActiveX
Validation of Valosin-Containing Protein (VCP) as a Therapeutic Target for Triple Negative Breast Cancer
https://openworks.mdanderson.org/sumexp21/1196/thumbnail.jp
Measuring the cosmological bulk flow using the peculiar velocities of supernovae
We study large-scale coherent motion in our universe using the existing Type
IA supernovae data. If the recently observed bulk flow is real, then some
imprint must be left on supernovae motion. We run a series of Monte Carlo
Markov Chain runs in various redshift bins and find a sharp contrast between
the z 0.05 data. The$z < 0.05 data are consistent with the bulk
flow in the direction (l,b)=({290^{+39}_{-31}}^{\circ},
{20^{+32}_{-32}}^{\circ}) with a magnitude of v_bulk = 188^{+119}_{-103} km/s
at 68% confidence. The significance of detection (compared to the null
hypothesis) is 95%. In contrast, z > 0.05 data (which contains 425 of the 557
supernovae in the Union2 data set) show no evidence for bulk flow. While the
direction of the bulk flow agrees very well with previous studies, the
magnitude is significantly smaller. For example, the Kashlinsky, et al.'s
original bulk flow result of v_bulk > 600 km/s is inconsistent with our
analysis at greater than 99.7% confidence level. Furthermore, our best-fit bulk
flow velocity is consistent with the expectation for the \Lambda CDM model,
which lies inside the 68% confidence limit.Comment: Version published in JCA
Mid-infrared optical parametric amplifier using silicon nanophotonic waveguides
All-optical signal processing is envisioned as an approach to dramatically
decrease power consumption and speed up performance of next-generation optical
telecommunications networks. Nonlinear optical effects, such as four-wave
mixing (FWM) and parametric gain, have long been explored to realize
all-optical functions in glass fibers. An alternative approach is to employ
nanoscale engineering of silicon waveguides to enhance the optical
nonlinearities by up to five orders of magnitude, enabling integrated
chip-scale all-optical signal processing. Previously, strong two-photon
absorption (TPA) of the telecom-band pump has been a fundamental and
unavoidable obstacle, limiting parametric gain to values on the order of a few
dB. Here we demonstrate a silicon nanophotonic optical parametric amplifier
exhibiting gain as large as 25.4 dB, by operating the pump in the mid-IR near
one-half the band-gap energy (E~0.55eV, lambda~2200nm), at which parasitic
TPA-related absorption vanishes. This gain is high enough to compensate all
insertion losses, resulting in 13 dB net off-chip amplification. Furthermore,
dispersion engineering dramatically increases the gain bandwidth to more than
220 nm, all realized using an ultra-compact 4 mm silicon chip. Beyond its
significant relevance to all-optical signal processing, the broadband
parametric gain also facilitates the simultaneous generation of multiple
on-chip mid-IR sources through cascaded FWM, covering a 500 nm spectral range.
Together, these results provide a foundation for the construction of
silicon-based room-temperature mid-IR light sources including tunable
chip-scale parametric oscillators, optical frequency combs, and supercontinuum
generators
Origin of the Pseudogap in High-Temperature Cuprate Superconductors
Cuprate high-temperature superconductors exhibit a pseudogap in the normal
state that decreases monotonically with increasing hole doping and closes at x
\approx 0.19 holes per planar CuO2 while the superconducting doping range is
0.05 < x < 0.27 with optimal Tc at x \approx 0.16. Using ab initio quantum
calculations at the level that leads to accurate band gaps, we found that
four-Cu-site plaquettes are created in the vicinity of dopants. At x \approx
0.05 the plaquettes percolate, so that the Cu dx2y2/O p{\sigma} orbitals inside
the plaquettes now form a band of states along the percolating swath. This
leads to metallic conductivity and below Tc to superconductivity. Plaquettes
disconnected from the percolating swath are found to have degenerate states at
the Fermi level that split and lead to the pseudogap. The pseudogap can be
calculated by simply counting the spatial distribution of isolated plaquettes,
leading to an excellent fit to experiment. This provides strong evidence in
favor of inhomogeneous plaquettes in cuprates.Comment: 24 pages (4 pages main text plus 20 pages supplement
Quantum teleportation using active feed-forward between two Canary Islands
Quantum teleportation [1] is a quintessential prerequisite of many quantum
information processing protocols [2-4]. By using quantum teleportation, one can
circumvent the no-cloning theorem [5] and faithfully transfer unknown quantum
states to a party whose location is even unknown over arbitrary distances. Ever
since the first experimental demonstrations of quantum teleportation of
independent qubits [6] and of squeezed states [7], researchers have
progressively extended the communication distance in teleportation, usually
without active feed-forward of the classical Bell-state measurement result
which is an essential ingredient in future applications such as communication
between quantum computers. Here we report the first long-distance quantum
teleportation experiment with active feed-forward in real time. The experiment
employed two optical links, quantum and classical, over 143 km free space
between the two Canary Islands of La Palma and Tenerife. To achieve this, the
experiment had to employ novel techniques such as a frequency-uncorrelated
polarization-entangled photon pair source, ultra-low-noise single-photon
detectors, and entanglement-assisted clock synchronization. The average
teleported state fidelity was well beyond the classical limit of 2/3.
Furthermore, we confirmed the quality of the quantum teleportation procedure
(without feed-forward) by complete quantum process tomography. Our experiment
confirms the maturity and applicability of the involved technologies in
real-world scenarios, and is a milestone towards future satellite-based quantum
teleportation
Hard Two-Photon Contribution to Elastic Lepton-Proton Scattering: Determined by the OLYMPUS Experiment
The OLYMPUS collaboration reports on a precision measurement of the
positron-proton to electron-proton elastic cross section ratio, ,
a direct measure of the contribution of hard two-photon exchange to the elastic
cross section. In the OLYMPUS measurement, 2.01~GeV electron and positron beams
were directed through a hydrogen gas target internal to the DORIS storage ring
at DESY. A toroidal magnetic spectrometer instrumented with drift chambers and
time-of-flight scintillators detected elastically scattered leptons in
coincidence with recoiling protons over a scattering angle range of to . The relative luminosity between the two beam species
was monitored using tracking telescopes of interleaved GEM and MWPC detectors
at , as well as symmetric M{\o}ller/Bhabha calorimeters at
. A total integrated luminosity of 4.5~fb was collected. In
the extraction of , radiative effects were taken into account
using a Monte Carlo generator to simulate the convolutions of internal
bremsstrahlung with experiment-specific conditions such as detector acceptance
and reconstruction efficiency. The resulting values of , presented
here for a wide range of virtual photon polarization ,
are smaller than some hadronic two-photon exchange calculations predict, but
are in reasonable agreement with a subtracted dispersion model and a
phenomenological fit to the form factor data.Comment: 5 pages, 3 figures, 2 table
A preliminary study of genetic factors that influence susceptibility to bovine tuberculosis in the British cattle herd
Associations between specific host genes and susceptibility to Mycobacterial infections such as tuberculosis have been reported in several species. Bovine tuberculosis (bTB) impacts greatly the UK cattle industry, yet genetic predispositions have yet to be identified. We therefore used a candidate gene approach to study 384 cattle of which 160 had reacted positively to an antigenic skin test (‘reactors’). Our approach was unusual in that it used microsatellite markers, embraced high breed diversity and focused particularly on detecting genes showing heterozygote advantage, a mode of action often overlooked in SNP-based studies. A panel of neutral markers was used to control for population substructure and using a general linear model-based approach we were also able to control for age. We found that substructure was surprisingly weak and identified two genomic regions that were strongly associated with reactor status, identified by markers INRA111 and BMS2753. In general the strength of association detected tended to vary depending on whether age was included in the model. At INRA111 a single genotype appears strongly protective with an overall odds ratio of 2.2, the effect being consistent across nine diverse breeds. Our results suggest that breeding strategies could be devised that would appreciably increase genetic resistance of cattle to bTB (strictly, reduce the frequency of incidence of reactors) with implications for the current debate concerning badger-culling
Control of intestinal stem cell function and proliferation by mitochondrial pyruvate metabolism.
Most differentiated cells convert glucose to pyruvate in the cytosol through glycolysis, followed by pyruvate oxidation in the mitochondria. These processes are linked by the mitochondrial pyruvate carrier (MPC), which is required for efficient mitochondrial pyruvate uptake. In contrast, proliferative cells, including many cancer and stem cells, perform glycolysis robustly but limit fractional mitochondrial pyruvate oxidation. We sought to understand the role this transition from glycolysis to pyruvate oxidation plays in stem cell maintenance and differentiation. Loss of the MPC in Lgr5-EGFP-positive stem cells, or treatment of intestinal organoids with an MPC inhibitor, increases proliferation and expands the stem cell compartment. Similarly, genetic deletion of the MPC in Drosophila intestinal stem cells also increases proliferation, whereas MPC overexpression suppresses stem cell proliferation. These data demonstrate that limiting mitochondrial pyruvate metabolism is necessary and sufficient to maintain the proliferation of intestinal stem cells
Quantum simulation of the wavefunction to probe frustrated Heisenberg spin systems
Quantum simulators are controllable quantum systems that can reproduce the
dynamics of the system of interest, which are unfeasible for classical
computers. Recent developments in quantum technology enable the precise control
of individual quantum particles as required for studying complex quantum
systems. Particularly, quantum simulators capable of simulating frustrated
Heisenberg spin systems provide platforms for understanding exotic matter such
as high-temperature superconductors. Here we report the analog quantum
simulation of the ground-state wavefunction to probe arbitrary Heisenberg-type
interactions among four spin-1/2 particles . Depending on the interaction
strength, frustration within the system emerges such that the ground state
evolves from a localized to a resonating valence-bond state. This spin-1/2
tetramer is created using the polarization states of four photons. The
single-particle addressability and tunable measurement-induced interactions
provide us insights into entanglement dynamics among individual particles. We
directly extract ground-state energies and pair-wise quantum correlations to
observe the monogamy of entanglement
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