477 research outputs found
Range Restricted Interpolation Using Cubic BĂŠzier Triangles.
A range restricted C1 interpolation local scheme to scattered data is derived. Each macro triangle of the
triangulated domain is split into three mini triangles and the interpolating surface on each mini triangle is a cubic
BĂŠzier triangle. Sufficient conditions derived for the non-negativity of these cubic BĂŠzier triangles are expressed
as lower bounds to the BĂŠzier ordinates. The non-negativity preserving interpolation scheme extends to the
construction of a range restricted interpolating surface with lower or upper constraints which are polynomial
surfaces of degree up to three. The scheme is illustrated with graphical examples
Endolaryngeale superolateralisatie bij tweezijdige stembandverlamming : techniek, evaluatiemethoden en resultaten
Bij een tweezijdige stemband verlamming met stilstand van beide stembanden
in mediane of paramediane stand is de glottis sterk verkleind, waardoor de
luchtwegweerstand is toegenomen. Hierdoor krijgt de patient dyspnoeklachten
die zich op twee manieren kunnen manifesteren: in de vorm van een
acute, ernstige dyspnoe direct na het ontstaan van de stembandstilstand of in
de vorm van geleidelijk toenemende dyspnoeklachten die kunnen verergeren
door inspanning of een laryngitis. In beide gevallen gaat de dyspnoe
vaak met een stridor gepaard. Ondanks de stilstaande stembanden blijft de
stem meestal goed, of is slechts in geringe mate hees, doordat de stand van de
stembanden gunstig is voor de fonatie.
In geval van een acute, ernstige dyspnoe is het verkrijgen van een vrije
luchtweg een eerste vereiste. Deze wordt verkregen door een tracheotomie of
een intubatie. De volgende stap is een glottisverwijdende ingreep. Het
hoofddoel van deze ingreep is het vergroten van de afstand tussen beide
stilstaande stembanden. Het directe gevolg van de vergroting van deze
afstand is echter een vermindering van de mogelijkheid tot stemgeving: de
stem wordt altijd slechter en soms zelfs afoon.
In de afgelopen 50 jaren heeft men voortdurend gezocht naar een methode
om de glottis te verwijden en daarbij de stemgeving zo goed mogelijk te
behouden.Bij de meeste operatiemethoden is dit slechts in zeer beperkte mate
gelukt.
Door de ontwikkeling van de endolaryngeale microchirurgische techniek van
de larynx werden echter nieuwe mogelijkheden geschapen. Deze methode
heeft als voordeel dat de larynx direct wordt benaderd en dat niet meer in een
vaak verlittekend halsgebied geopereerd behoeft te worden
Conceptual design of a novel power-augmented hydrokinetic run-of- river turbine
Other than the water stream from ocean, river stream is also being considered as a viable source of renewable energy. Many researchers has approached and started the studies of river stream in order to harness the maximum power from the rivers. River stream offers promising energy especially to the rural areas which are surrounded by rivers. From previous studies, it shows that majority of the hydrokinetic run-of-river turbine systems are designed in vertical and horizontal axis. Besides, some of the vertical and horizontal axis turbines are also enclosed by the duct or diffuser in order to guide the river stream and increase the flow velocity. However, the design of the shape of diffuser faced the challenges during fabrication phase and additional supporting structures are needed during installation, causing the increases in the overall cost. In this paper, the authors would like to propose a conceptual design of a novel power-augmented hydrokinetic run-of-river turbine which utilizes the concept of cross-axis wind turbine and simple augmented guide vane. This conceptual design of hydrokinetic turbine able to capture the advantages of both the horizontal and vertical axis turbines. Helical blade design was chosen for this conceptual design due to its ability to capture the skewed flow created by the difference in velocity of upper and lower faces of turbine. When the vertical-axis turbine rotates, the angle of attack of each blade varies cyclically. The cyclical variation of the angle of attack creates cyclical blade loading, which increases the fatigue experienced by blades. Most of the cyclical loading can be alleviated by using helical instead of straight blades. The conceptual design of this cross-axis turbine with helical blade is similar to the Gorlov helical turbine but there are some differences in the radial blades which are designed as 8 degrees upper and lower respectively to the horizontal axis of the connector hub. The two layers radial blade-rotors are offset by 60 degrees. The turbine
system is designed by intercepting the two guide vanes in between three individual turbines and also two diffuservanes
as the outer part of the system. The NACA 0015 airfoil profile is used as turbine blade in this design. The
construction costs of cross-axis concept turbine and the helical blades are relatively low (about 30%) compared
with the huge ducted and diffuser turbine. A 3D model was constructed and simulated by using the computational
fluid dynamics software, ANSYS-Fluent. In the simulation, the velocity of water flow and the rotational speed of
turbine were increased with the integration of the guide-vane and diffuser features. It is estimated that this
conceptual design turbine will achieve 60% increase in energy gain
Streamer Wave Events Observed in Solar Cycle 23
In this paper we conduct a data survey searching for well-defined streamer
wave events observed by the Large Angle and Spectrometric Coronagraph (LASCO)
on-board the Solar and Heliospheric Observatory (SOHO) throughout Solar Cycle
23. As a result, 8 candidate events are found and presented here. We compare
different events and find that in most of them the driving CMEs ejecta are
characterized by a high speed and a wide angular span, and the CME-streamer
interactions occur generally along the flank of the streamer structure at an
altitude no higher than the bottom of the field of view of LASCO C2. In
addition, all front-side CMEs have accompanying flares. These common
observational features shed light on the excitation conditions of streamer wave
events.
We also conduct a further analysis on one specific streamer wave event on 5
June 2003. The heliocentric distances of 4 wave troughs/crests at various
exposure times are determined; they are then used to deduce the wave properties
like period, wavelength, and phase speeds. It is found that both the period and
wavelength increase gradually with the wave propagation along the streamer
plasma sheet, and the phase speed of the preceding wave is generally faster
than that of the trailing ones. The associated coronal seismological study
yields the radial profiles of the Alfv\'en speed and magnetic field strength in
the region surrounding the streamer plasma sheet. Both quantities show a
general declining trend with time. This is interpreted as an observational
manifestation of the recovering process of the CME-disturbed corona. It is also
found that the Alfv\'enic critical point is at about 10 R where the
flow speed, which equals the Alfv\'en speed, is 200 km s
Vasorelaxant effect of a phenylethylamine analogue based on schwarzinicine A an alkaloid isolated from the leaves of Ficus schwarzii
N-Phenethyl-1-phenyl-pentan-3-amine (1) is a new compound synthesised as a simplified analogue of schwarzinicine A (2), a natural compound extracted from Ficus schwarzii. Compound 1 differs from compound 2 due to its structural simplification, featuring two phenyl rings without methoxy substitution, as opposed to compound 2, which possesses three 3,4-dimethoxy aromatic rings. Our previous research findings highlighted the calcium-inhibitory effects of compound 2, but the mechanism of action for compound 1 remains unexplored, serving as the primary focus of this study. Building upon our earlier research, this study aimed to elucidate compound 1's calcium-modulating potential by using rat-isolated aortae in an organ bath set-up and HEK cells expressing hTRPC channels with the fluorometric assay to measure calcium influx. Compound 1 elicited a vasorelaxation response (Emax 111.4%) similar to its parent compound 2 (Emax 123.1%), and inhibited hTRPC3-, hTRPC4-, hTRPC5-, and hTRPC6-mediated calcium influx into HEK cells with IC50 values of 6, 2, 2, 5 ÂľM, respectively. Compound 1 has a similar pharmacological profile as its parent compound 2, whereby it exerts a vasorelaxant effect by attenuating calcium influx and inhibits multiple TRPC channels
A pH sensor based on electric properties of nanotubes on a glass substrate
We fabricated a pH-sensitive device on a glass substrate based on properties of carbon nanotubes. Nanotubes were immobilized specifically on chemically modified areas on a substrate followed by deposition of metallic source and drain electrodes on the area. Some nanotubes connected the source and drain electrodes. A top gate electrode was fabricated on an insulating layer of silane coupling agent on the nanotube. The device showed properties of ann-type field effect transistor when a potential was applied to the nanotube from the top gate electrode. Before fabrication of the insulating layer, the device showed that thep-type field effect transistor and the current through the source and drain electrodes depend on the buffer pH. The current increases with decreasing pH of the CNT solution. This device, which can detect pH, is applicable for use as a biosensor through modification of the CNT surface
Characterization of Loading Responses and Failure Loci of a Boron Steel Spot Weld
Boron steel, classed as an ultra high-strength steel (UHSS), has been utilized in anti-intrusion systems in automobiles, providing high strength and weight-saving potential through gage reduction. UHSS spot welds exhibit unique hardness distributions, with a hard nugget and outlying base material, but with a soft heat-affected zone in-between these regions. This soft zone reduces the strength of the weld and makes it susceptible to failure. Due to the interaction of various weld zones that occurs during loading, there is a need to characterize the loading response of the weld for accurate failure predictions. The loading response of certain weld zones, as well as failure loci, was obtained through physical simulation of the welding process. The results showed a significant difference in mechanical behavior through the weld length. An important result is that instrumented indentation was shown to be a valid, quantitative method for verifying the accuracy with which weld microstructure has been recreated with regard to the target weld microstructure
Search for a W' boson decaying to a bottom quark and a top quark in pp collisions at sqrt(s) = 7 TeV
Results are presented from a search for a W' boson using a dataset
corresponding to 5.0 inverse femtobarns of integrated luminosity collected
during 2011 by the CMS experiment at the LHC in pp collisions at sqrt(s)=7 TeV.
The W' boson is modeled as a heavy W boson, but different scenarios for the
couplings to fermions are considered, involving both left-handed and
right-handed chiral projections of the fermions, as well as an arbitrary
mixture of the two. The search is performed in the decay channel W' to t b,
leading to a final state signature with a single lepton (e, mu), missing
transverse energy, and jets, at least one of which is tagged as a b-jet. A W'
boson that couples to fermions with the same coupling constant as the W, but to
the right-handed rather than left-handed chiral projections, is excluded for
masses below 1.85 TeV at the 95% confidence level. For the first time using LHC
data, constraints on the W' gauge coupling for a set of left- and right-handed
coupling combinations have been placed. These results represent a significant
improvement over previously published limits.Comment: Submitted to Physics Letters B. Replaced with version publishe
Search for the standard model Higgs boson decaying into two photons in pp collisions at sqrt(s)=7 TeV
A search for a Higgs boson decaying into two photons is described. The
analysis is performed using a dataset recorded by the CMS experiment at the LHC
from pp collisions at a centre-of-mass energy of 7 TeV, which corresponds to an
integrated luminosity of 4.8 inverse femtobarns. Limits are set on the cross
section of the standard model Higgs boson decaying to two photons. The expected
exclusion limit at 95% confidence level is between 1.4 and 2.4 times the
standard model cross section in the mass range between 110 and 150 GeV. The
analysis of the data excludes, at 95% confidence level, the standard model
Higgs boson decaying into two photons in the mass range 128 to 132 GeV. The
largest excess of events above the expected standard model background is
observed for a Higgs boson mass hypothesis of 124 GeV with a local significance
of 3.1 sigma. The global significance of observing an excess with a local
significance greater than 3.1 sigma anywhere in the search range 110-150 GeV is
estimated to be 1.8 sigma. More data are required to ascertain the origin of
this excess.Comment: Submitted to Physics Letters
Measurement of the Lambda(b) cross section and the anti-Lambda(b) to Lambda(b) ratio with Lambda(b) to J/Psi Lambda decays in pp collisions at sqrt(s) = 7 TeV
The Lambda(b) differential production cross section and the cross section
ratio anti-Lambda(b)/Lambda(b) are measured as functions of transverse momentum
pt(Lambda(b)) and rapidity abs(y(Lambda(b))) in pp collisions at sqrt(s) = 7
TeV using data collected by the CMS experiment at the LHC. The measurements are
based on Lambda(b) decays reconstructed in the exclusive final state J/Psi
Lambda, with the subsequent decays J/Psi to an opposite-sign muon pair and
Lambda to proton pion, using a data sample corresponding to an integrated
luminosity of 1.9 inverse femtobarns. The product of the cross section times
the branching ratio for Lambda(b) to J/Psi Lambda versus pt(Lambda(b)) falls
faster than that of b mesons. The measured value of the cross section times the
branching ratio for pt(Lambda(b)) > 10 GeV and abs(y(Lambda(b))) < 2.0 is 1.06
+/- 0.06 +/- 0.12 nb, and the integrated cross section ratio for
anti-Lambda(b)/Lambda(b) is 1.02 +/- 0.07 +/- 0.09, where the uncertainties are
statistical and systematic, respectively.Comment: Submitted to Physics Letters
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