1,977 research outputs found
The decay constants and in the continuum limit of domain wall lattice QCD
We present results for the decay constants of the and mesons
computed in lattice QCD with dynamical flavours. The simulations are
based on RBC/UKQCD's domain wall ensembles with both physical and unphysical
light-quark masses and lattice spacings in the range 0.11--0.07fm. We
employ the domain wall discretisation for all valence quarks.
The results in the continuum limit are
and
and
.
Using these results in a Standard Model analysis we compute the predictions
and
for the
CKM matrix elements
Relating Green-Schwarz and Extended Pure Spinor Formalisms by Similarity Transformation
In order to gain deeper understanding of pure-spinor-based formalisms of
superstring, an explicit similarity transformation is constructed which
provides operator mapping between the light-cone Green-Schwarz (LCGS) formalism
and the extended pure spinor (EPS) formalism, a recently proposed
generalization of the Berkovits' formalism in an enlarged space. By applying a
systematic procedure developed in our previous work, we first construct an
analogous mapping in the bosonic string relating the BRST and the light-cone
formulations. This provides sufficient insights and allows us to construct the
desired mapping in the more intricate case of superstring as well. The success
of the construction owes much to the enlarged field space where pure spinor
constraints are removed and to the existence of the ``B-ghost'' in the EPS
formalism.Comment: 37pages, no figur
Deposition reactors for solar grade silicon: a comparative thermal analysis of a Siemens reactor and a fluidized bed reactor
Polysilicon production costs contribute approximately to 25-33% of the overall cost of the solar panels and a similar fraction of the total energy invested in their fabrication. Understanding the energy losses and the behaviour of process temperature is an essential requirement as one moves forward to design and build large scale polysilicon manufacturing plants. In this paper we present thermal models for two processes for poly production, viz., the Siemens process using trichlorosilane (TCS) as precursor and the fluid bed process using silane (monosilane, MS).We validate the models with some experimental measurements on prototype laboratory reactors relating the temperature profiles to product quality. A model sensitivity analysis is also performed, and the efects of some key parameters such as reactor wall emissivity, gas distributor temperature, etc., on temperature distribution and product quality are examined. The information presented in this paper is useful for further understanding of the strengths and weaknesses of both deposition technologies, and will help in optimal temperature profiling of these systems aiming at lowering production costs without compromising the solar cell quality
Enhanced Fusion-Evaporation Cross Sections in Neutron-Rich Sn on Ni
Evaporation residue cross sections have been measured with neutron-rich
radioactive Sn beams on Ni in the vicinity of the Coulomb
barrier. The average beam intensity was particles per second
and the smallest cross section measured was less than 5 mb. Large subbarrier
fusion enhancement was observed. Coupled-channels calculations taking into
account inelastic excitation and neutron transfer underpredict the measured
cross sections below the barrier.Comment: 4 pages including 1 table and 3 figure
Structural assessment of the EU-DEMO WCLL Central Outboard Blanket Segment under normal and off-normal operating conditions
Gauge-invariant charged, monopole and dyon fields in gauge theories
We propose explicit recipes to construct the euclidean Green functions of
gauge-invariant charged, monopole and dyon fields in four-dimensional gauge
theories whose phase diagram contains phases with deconfined electric and/or
magnetic charges. In theories with only either abelian electric or magnetic
charges, our construction is an euclidean version of Dirac's original proposal,
the magnetic dual of his proposal, respectively. Rigorous mathematical control
is achieved for a class of abelian lattice theories. In theories where electric
and magnetic charges coexist, our construction of Green functions of
electrically or magnetically charged fields involves taking an average over
Mandelstam strings or the dual magnetic flux tubes, in accordance with Dirac's
flux quantization condition. We apply our construction to 't Hooft-Polyakov
monopoles and Julia-Zee dyons. Connections between our construction and the
semiclassical approach are discussed
Genome-wide association and prediction reveals genetic architecture of cassava mosaic disease resistance and prospects for rapid genetic improvement
Published: 13 May 2016Cassava (Manihot esculenta Crantz) is a crucial, under-researched crop feeding millions worldwide, especially in Africa. Cassava mosaic disease (CMD) has plagued production in Africa for over a century. Biparental mapping studies suggest primarily a single major gene mediates resistance. To investigate this genetic architecture, we conducted the first genome-wide association mapping study in cassava with up to 6128 genotyping-by-sequenced African breeding lines and 42,113 reference genome-mapped single-nucleotide polymorphism (SNP) markers. We found a single region on chromosome 8 that accounts for 30 to 66% of genetic resistance in the African cassava germplasm. Thirteen additional regions with small effects were also identified. Further dissection of the major quantitative trait locus (QTL) on chromosome 8 revealed the presence of two possibly epistatic loci and/or multiple resistance alleles, which may account for the difference between moderate and strong disease resistances in the germplasm. Search of potential candidate genes in the major QTL region identified two peroxidases and one thioredoxin. Finally, we found genomic prediction accuracy of 0.53 to 0.58 suggesting that genomic selection (GS) will be effective both for improving resistance in breeding populations and identifying highly resistant clones as varieties
Biophysical and sociocultural factors underlying spatial trade-offs of ecosystem services in semiarid watersheds
Biophysical and social systems are linked to form social-ecological systems whose sustainability depends on their capacity to absorb uncertainty and cope with disturbances. In this study, we explored the key biophysical and socio-cultural factors underlying ecosystem service supply in two semiarid watersheds of southern Spain. These included variables associated with the role that freshwater flows and biodiversity play in securing the system’s capacity to sustain essential ecosystem services and their relationship with social demand for services, local water governance, and land-use intensification. Our results reveal the importance of considering the invisible dimensions of water and biodiversity, i.e. green freshwater flows and trait-based indicators, because of their relevance to the supply of ecosystem services. Furthermore, they uncover the importance of traditional irrigation canals, a local water governance system, in maintaining the ecosystems’ capacity to supply services. The study also highlights the complex trade-offs that occur because of the spatial mismatch between ecosystem service supply (upstream) and ecosystem service demand (downstream) in watersheds. Finally, we found that land-use intensification generally resulted in losses of the biophysical factors that underpin the supply of some ecosystem services, increases in social demand for less diversified services, and the abandonment of local governance practices. Attempts to manage social-ecological systems toward sustainability at the local scale should identify the key biophysical and socio-cultural factors that are essential for maintaining ecosystem services and should recognize existing interrelationships between them. Land-use management should also take into account ecosystem service trade-offs and the consequences resulting from land-use intensificationFunding for the development of this research was provided by a postdoctoral grant from the Spanish National Institute for Agriculture and Food Research and Technology (INIA), which is cofunded by the Social European Fund; the Seventh Framework Programme of the European Commission (FP7, 2007-2013) under the BESAFE project (Biodiversity and Ecosystem Services: Arguments for our Future Environment, Contract No. 282743; http://www.besafe-project. net); and the OpenNESS Project (Operationalisation of Natural capital and Ecosystem Services: From Concepts to Real-World Applications, Contract No. 308428
Lumbalgia mecánica crónica en pacientes con vértebra limbus anterior
La vértebra limbus es un hallazgo radiológico de prevalencia desconocida y significado incierto. Se trata de un defecto óseo que afecta al margen de los cuerpos vertebrales, con un fragmento desprendido de morfología triangular y bordes escleróticos. Se produce como consecuencia de una herniación intraósea del núcleo pulposo a través del anillo apofisario vertebral, antes de la fusión completa del cuerpo vertebral. En este artículo se describen tres casos clínicos de pacientes jóvenes (de 19, 20 y 22 años), reclusos en el Centro Penitenciario de Jóvenes (Barcelona, España), diagnosticados de lumbalgia mecánica crónica, y portadores de vértebra limbus lumbar. Nuestros hallazgos, y la revisión sistemática de la escasa literatura disponible, ponen en duda algunas convicciones actuales sobre la vértebra limbus
- …