6,807 research outputs found
Advanced turboprop vibratory characteristics
The assembly of SR5 advanced turboprop blades to develop a structural dynamic data base for swept props is reported. Steady state blade deformation under centrifugal loading and vibratory characteristics of the rotor assembly were measured. Vibration was induced through a system of piezoelectric crystals attached to the blades. Data reduction procedures are used to provide deformation, mode shape, and frequencies of the assembly at predetermined speeds
Medical Library Association Historical Marker to be Installed in Philadelphia
During 2015, its 117th anniversary year, MLA will celebrate a novel and permanent way of informing both residents and visitors to Philadelphia about the association. Several months ago, the Pennsylvania Historical and Museum Commission voted to approve the nomination of an official State Historical Marker to commemorate MLA\u27s founding in Philadelphia in 1898. The text of the marker will not be revealed until the marker\u27s dedication ceremony in keeping with the commission\u27s guidelines
Monomial transformations of the projective space
We prove that, over any field, the dimension of the indeterminacy locus of a
rational transformation of which is defined by monomials of the same
degree with no common factors is at least , provided that the
degree of as a map is not divisible by . This implies upper bounds on
the multidegree of
Mortality in intensive care: The impact of bacteremia and the utility of systemic inflammatory response syndrome
Background:
The purpose of this study was to determine the impact of bacteremia on intensive care unit (ICU) mortality and to develop a bacteremia prediction tool using systemic inflammatory response syndrome (SIRS) criteria.
Methods:
Patients included those aged >18 years who had blood cultures taken in the ICU from January 1, 2011-December 31, 2013. Eligible patients were identified from microbiology records of the Glasgow Royal Infirmary, Scotland. Clinical and outcome data were gathered from ICU records. Patients with clinically significant bacteremia were matched to controls using propensity scores. SIRS criteria were gathered and used to create decision rules to predict the absence of bacteremia. The main outcome was mortality at ICU discharge. The utility of the decision tools was measured using sensitivity and specificity.
Results:
One hundred patients had a clinically significant positive blood culture and were matched to 100 controls. Patients with bacteremia had higher ICU mortality (odds ratio [OR], 2.35; P = .001) and longer ICU stay (OR, 17.0 vs 7.8 days; P ≤ .001). Of 1,548 blood culture episodes, 1,274 met ≥2 SIRS criteria (106 significant positive cultures and 1,168 negative cultures). There was no association between SIRS criteria and positive blood cultures (P = .11). A decision rule using 3 SIRS criteria had optimal predictive performance (sensitivity, 56%; specificity, 50%) but low accuracy.
Conclusions:
ICU patients with bacteremia have increased mortality and length of ICU stay. SIRS criteria cannot be used to identify patients at low risk of bacteremia
Unusual damage to potatoes by the two-spotted spider mite, Tetranychus telarius (L.), in the Lower Fraser Valley
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Integral Grothendieck-Riemann-Roch theorem
We show that, in characteristic zero, the obvious integral version of the
Grothendieck-Riemann-Roch formula obtained by clearing the denominators of the
Todd and Chern characters is true (without having to divide the Chow groups by
their torsion subgroups). The proof introduces an alternative to Grothendieck's
strategy: we use resolution of singularities and the weak factorization theorem
for birational maps.Comment: 24 page
Theoretical Parametric Study of the Relative Advantages of Winglets and Wing-Tip Extensions
For identical increases in bending moment, a winglet provides a greater gain in induced efficiency than tip extension. Winglet toe angle allows design trades between efficiency and root moment. A winglet shows the greatest benefit when the wing loads are heavy near the tip. Washout diminishes the benefit of either tip modification, and the gain in induced efficiency becomes a function of lift coefficient; thus, heavy wing loadings obtain the greatest benefit from a winglet, and low-speed performance is enhanced even more than cruise performance. Both induced efficiency and bending moment increase with winglet length and outward cant. The benefit of a winglet relative to a tip extension is greatest for a nearly vertical winglet. Root bending moment is proportional to the minimum weight of bending material required in the wing; thus, it is a valid index of the impact of tip modifications on a new wing design
Soil insecticides for control of the tuber flea beetle, Epitrix Tuberis Gent., in the Lower Fraser Valley of British Columbia
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Spectral geometry of -Minkowski space
After recalling Snyder's idea of using vector fields over a smooth manifold
as `coordinates on a noncommutative space', we discuss a two dimensional
toy-model whose `dual' noncommutative coordinates form a Lie algebra: this is
the well known -Minkowski space.
We show how to improve Snyder's idea using the tools of quantum groups and
noncommutative geometry.
We find a natural representation of the coordinate algebra of
-Minkowski as linear operators on an Hilbert space study its `spectral
properties' and discuss how to obtain a Dirac operator for this space.
We describe two Dirac operators. The first is associated with a spectral
triple. We prove that the cyclic integral of M. Dimitrijevic et al. can be
obtained as Dixmier trace associated to this triple. The second Dirac operator
is equivariant for the action of the quantum Euclidean group, but it has
unbounded commutators with the algebra.Comment: 23 pages, expanded versio
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