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Numerical simulation of a film cooled turbine blade leading edge including heat transfer effects
textComputations and experiments were run to study heat transfer and overall effectiveness for a simulated turbine blade leading edge. Computational predictions were run for a film cooled leading edge model using a conjugate numerical method to predict the normalized “metal” temperatures for the model. This computational study was done in conjunction with a parallel effort to experimentally determine normalized metal temperatures, i.e. overall effectiveness, using a specially designed high conductivity model. Predictions of overall effectiveness were higher than experimentally measured values in the stagnation region, but lower along the downstream section of the leading edge. Reasons for the differences between computational predictions and experimental measurements were examined. Also of interest was the validity of Taw as the driving temperature for heat transfer into the blade, and this was examined via computations. Overall, this assumption gave reasonable results except near the stagnation line. Experiments were also conducted on a leading edge with no film cooling to gain a better understanding of the additional cooling provided by film cooling. Heat flux was also measured and external and internal heat transfer coefficients were determined. The results showed roughly constant overall effectiveness on the external surface.Mechanical Engineerin
Fission barriers in actinides in covariant density functional theory: the role of triaxiality
Relativistic mean field theory allowing for triaxial deformations is applied
for a systematic study of fission barriers in the actinide region. Different
pairing schemes are studied in details and it is shown that covariant density
functional theory is able to describe fission barriers on a level of accuracy
comparable with non-relativistic calculations, even with the best
phenomenological macroscopic+microscopic approaches. Triaxiality in the region
of the first saddle plays a crucial role in achieving that.Comment: 11 pages, 13 figure
Fission barriers in covariant density functional theory: extrapolation to superheavy nuclei
Systematic calculations of fission barriers allowing for triaxial deformation
are performed for even-even superheavy nuclei with charge number
using three classes of covariant density functional models. The softness of
nuclei in the triaxial plane leads to an emergence of several competing fission
pathes in the region of the inner fission barrier in some of these nuclei. The
outer fission barriers are considerably affected by triaxiality and octupole
deformation. General trends of the evolution of the inner and the outer fission
barrier heights are discussed as a function of the particle numbers.Comment: 24 pages, 8 tables, 12 figure
Compactness for Holomorphic Supercurves
We study the compactness problem for moduli spaces of holomorphic supercurves
which, being motivated by supergeometry, are perturbed such as to allow for
transversality. We give an explicit construction of limiting objects for
sequences of holomorphic supercurves and prove that, in important cases, every
such sequence has a convergent subsequence provided that a suitable extension
of the classical energy is uniformly bounded. This is a version of Gromov
compactness. Finally, we introduce a topology on the moduli spaces enlarged by
the limiting objects which makes these spaces compact and metrisable.Comment: 38 page
Lower Bounds for Heights in Relative Galois Extensions
The goal of this paper is to obtain lower bounds on the height of an
algebraic number in a relative setting, extending previous work of Amoroso and
Masser. Specifically, in our first theorem we obtain an effective bound for the
height of an algebraic number when the base field is a
number field and is Galois. Our second result
establishes an explicit height bound for any non-zero element which is
not a root of unity in a Galois extension , depending on
the degree of and the number of conjugates of
which are multiplicatively independent over . As a consequence, we
obtain a height bound for such that is independent of the
multiplicative independence condition
Metabolome Analysis of the Interaction Between Perennial Ryegrass (\u3cem\u3eLolium Perenne\u3c/em\u3e) and the Fungal Endophyte \u3cem\u3eNeotyphodium Lolii\u3c/em\u3e
Perennial ryegrass (Lolium perenne L.) and tall fescue (Festuca arundinacea Schreb.) frequently contain endophytic fungi (Neotyphodium lolii in perennial ryegrass and N. coenophialum in tall fescue). The presence of the endophyte has been shown to improve seedling vigour, persistence and drought tolerance in marginal environments as well as provide protection against some insect pests. Endophyte-infected grasses also produce a wide range of metabolites, including ergopeptine alkaloids, indole-isoprenoid lolitrems, pyrrolizidine alkaloids, and pyrrolopyrazine alkaloids. In contrast to information on alkaloids and animal toxicosis, the beneficial physiological aspects of the endophyte/grass interactions have not been well characterised. The physiological mechanisms which lead to increased plant vigour and enhanced tolerance to abiotic stresses unrelated to the reduction in pest damage to endophyte-infected grasses are unknown. Recent technological advances in metabolomics enable dynamic changes in the metabolome of an organism under varying experimental conditions to be studied. This provides opportunities for the investigation and validation of each and every detected metabolite, investigation of known metabolic pathways through searching of databases of known metabolites, molecular formula determination of unknown metabolites and creation of pathways from novel metabolites
Analogies between optical propagation and heat diffusion: applications to microcavities, gratings and cloaks
International audienceA new analogy between optical propagation and heat diffusion in heterogeneous anisotropic media has beenproposed recently [S. Guenneau, C. Amra, and D. Veynante, Optics Express Vol. 20, 8207-8218 (2012)]. A detailedderivation of this unconventional correspondence is presented and developed. In time harmonic regime, all thermalparameters are related to optical ones in artificial metallic media, thus making possible to use numerical codesdeveloped for optics. Then the optical admittance formalism is extended to heat conduction in multilayeredstructures. The concepts of planar micro-cavities, diffraction gratings, and planar transformation optics for heatconduction are addressed. Results and limitations of the analogy are emphasized
Radiation from Excited Vortex in the Abelian Higgs Model
Excitation of a vortex in the Abelian Higgs model is investigated with the
help of a polynomial approximation. The excitation can be regarded as a
longitudinal component of the vector field trapped by the vortex. The energy
and profile of the excitation are found. Back-reaction of the excitation on the
vortex is calculated in the small limit. It turns out that in the
presence of the excitation the vortex effectively becomes much wider - its
radius oscillates in time and for all times it is not smaller than the radius
of the unexcited vortex. Moreover, we find that the vector field of the excited
vortex has long range radiative component. Bound on the amplitude of the
excitation is also found.Comment: Latex, 20 pages. 2 figures attached as .uu file to be decoded and
used as input for epsfbox command which is already included in the main Latex
fil
Continuous selections of multivalued mappings
This survey covers in our opinion the most important results in the theory of
continuous selections of multivalued mappings (approximately) from 2002 through
2012. It extends and continues our previous such survey which appeared in
Recent Progress in General Topology, II, which was published in 2002. In
comparison, our present survey considers more restricted and specific areas of
mathematics. Note that we do not consider the theory of selectors (i.e.
continuous choices of elements from subsets of topological spaces) since this
topics is covered by another survey in this volume
Future Directions in the Molecular Breeding of Forage and Turf
Key points Molecular breeding of forage and turf plants and their endosymbionts has entered the post-genomic era with a large amount of structural genomics information and genomic resources available for key forage and turf species and relevant model systems. A primary future challenge is the conversion of this information into useful functional knowledge for the development of molecular breeding technologies and products that address a range of high impact outcome scenarios in forage and turf. High-throughput approaches for spatial and temporal analysis, from genome to phenome, and the respective data integration in a systems biology context will be critical for the establishment of stringent gene-function correlations. Translational genomics will permit results obtained using model systems to have major impact on the understanding of the molecular basis of plant processes and direct application to the molecular breeding of forage and turf plants. These developments will be enhanced through applications of transgenesis and functionally-associated genetic markers in forage and turf molecular breeding building on genomic and post-genomic discoveries in these target species
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