57 research outputs found
Chiral observables and S-duality in N = 2⋆ U(N ) gauge theories
No full textWe study N=2* theories with gauge group U(N ) and use equivariant localization to calculate the quantum expectation values of the simplest chiral ring elements. These are expressed as an expansion in the mass of the adjoint hypermultiplet, with coefficients given by quasi-modular forms of the S-duality group. Under the action of this group, we construct combinations of chiral ring elements that transform as modular forms of definite weight. As an independent check, we confirm these results by comparing the spectral curves of the associated Hitchin system and the elliptic Calogero-Moser system. We also propose an exact and compact expression for the 1-instanton contribution to the expectation value of the chiral ring elements
Treatment of epithelioid sarcoma at the Royal Marsden Hospital
No full textPURPOSE:
The aim of this study was to assess treatment and outcome with respect to clinical and pathological features.
PATIENTS AND METHODS:
Thirty-nine patients were identified (range 7-66 years, mean 23). Initial treatment comprised local excision in 11 patients and wide excision in 14. Post-operative external beam radiotherapy was prescribed in 22 patients with a total dose of 60 Gy, delivered in two phases.
RESULTS:
The cause-specific survival for the entire group was 79, 63, 56 and 45% at 1, 3, 5 and 10 years, respectively. A distal limb location was associated with a better prognosis than proximal limb location (P = 0.04).
CONCLUSIONS:
Our data favour treatment with wide functional excision followed by radical dose radiotherapy in attempt to minimize risk of local recurrence, especially when primary tumours are bigger than 3 cm. Our data also suggest the same treatment for local recurrence, when technically possible, to avoid amputation
Analysis of Fracture Toughness Data for Pressurised Water Reactor Pressure Vessels Obtained in the Ductile to Brittle Transition Region
No full textInstanton corrections for m and Ω
No full textIn this paper, we study instanton corrections in the N=2⋆ gauge theory by using its description in string theory as a freely-acting orbifold. The latter is used to compute, using the worldsheet, the deformation of the Yang–Mills action. In addition, we calculate the deformed instanton partition function, thus extending the results to the non-perturbative sector of the gauge theory. As we point out, the structure of the deformation is extremely similar to the Ω-deformation, therefore confirming the universality of the construction. Finally, we comment on the realisation of the mass deformation using physical vertex operators by exploiting the equivalence between Scherk–Schwarz deformations and freely-acting orbifolds
A statistical model for the analysis and prediction of the effect of neutron irradiation on Charpy impact energy curves
No full textP-208. Transvaginal colour Doppler sonography in menopausal women who had hormone replacement therapy
No full textMicrostructure and cutting properties of unconventional high speed steels prepared by powder metallurgy
No full textTranslated from Slovak (Report of the Inst. of Materials Research, Slovak Academy of Sciences, Kosice, 1998)Available from British Library Document Supply Centre-DSC:9023.190(VR-Trans--9200)T / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo
Fracture behaviour of radiolytically oxidised reactor core graphites: a view
No full textThis paper provides a view on the fracture behaviour of polygranular graphites, used to moderate gas cooled nuclear reactors. Graphite is often cited as a classic example of a brittle material because failure, in tension, is associated with small strains. However, attempts to characterise the fracture behaviour of graphite by linear elastic fracture mechanics methods have been largely unsuccessful. Observations of graphite fracture show that elastic strain energy may be dissipated by the formation of distributed microcracks, and their formation may be responsible for nonlinearity in the rising load-displacement curve. Progressive softening behaviour may also be observed in some specimens after the peak load. This type of load-displacement behaviour is a characteristic of quasi-brittle materials. Radiolytic oxidation increases the proportion of porosity within reactor core graphite so that the microstructure becomes increasingly skeletal. Consideration is given to the fracture of radiolytically oxidised graphite to support an argument for quasi-brittle behaviour. © 2010 Institute of Materials
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