Two body scattering length of Yukawa model on a lattice

The extraction of scattering parameters from Euclidean simulations of a Yukawa model in a finite volume with periodic boundary conditions is analyzed both in non relativistic quantum mechanics and in quantum field theory.Comment: 4 pages, talk at "18th International IUPAP conference on Few Body Problems in Physics" (Sao Paulo, August 2006

Nuclear models on a lattice

We present the first results of a quantum field approach to nuclear models obtained by lattice techniques. Renormalization effects for fermion mass and coupling constant in case of scalar and pseudoscalar interaction lagrangian densities are discussed.Comment: 4 pages - 7 figures ; Invited talk to QCD 05: 12th International QCD Conference, 4-9 Jul 2005, Montpellier, France ; To appear in Nucl. Phys. B (Proc. Suppl.

Ghost-gluon coupling, power corrections and ΛMSˉ\Lambda_{\bar{MS}} from twisted-mass lattice QCD at Nf=2N_f=2

A non-perturbative calculation of the ghost-gluon running QCD coupling constant is performed using $N_f=2$ twisted-mass dynamical fermions. The extraction of $\Lambda_{\bar{MS}}$ in the chiral limit reveals the presence of a non-perturbative OPE contribution that is assumed to be dominated by a dimension-two \VEV{A^2} condensate. In this contest a novel method for calibrating the lattice spacing in lattice simulations is presented.Comment: 7 pages, 4 figures, XXVIII International Symposium on Lattice Field Theory 201

Utilization of Guarango (Caesalpinia spinosa) in the Province of Loja

Guarango (Caesalpinia spinosa) was studied in different parts of Loja province, mainly Loja, Catamayo, Gonzanamá, and Paltas, to use this species in the food and chemical industries because many studies in our country show that this species is not correctly used. It started with studies of the yields according to the place and time of recollection, after which the correct treatment was found, like the kind of grinding to optimize the handling of the sample, the chemical determination (tannins) in the pod, and its bromatological characteristics (moisture, fat, and protein). The chemical determination of tannins was done through titration of a macerated pod using carmine indigo and KMnO4 to 0,1 N, while bromatological determination with moisture, fat, and protein was applied using the standard methods of AOAC 7003, AOAC 7.056 y AOAC 47.021, respectively. In these results, it was found that there is little variability in experiments of percent of integument, endosperm, and germ, while in experiments of moisture, the amount of pod and seeds had significant differences. In addition, the percentage of tannins was excellent for use in the leather industry. While the germen had qualities of a good food supplement due to its high fat and protein content and low moisture. Finally, a method of extraction of the guarango parts could be designed that can be easily replicable by farmers. Based on the results, we can conclude that it is possible to establish ventures with guarango (C. spinosa) due to the remarkable properties of this species in food, textiles, and other industries. Keywords: Caesalpinia spinosa, guarango, pod, germ, used. Resumen Se realizó un estudio sobre el guarango (Caesalpinia spinosa) de diferentes cantones de la provincia de Loja, principalmente: Loja, Catamayo, Gonzanamá y Paltas, con la finalidad de aprovechar esta especie ofreciendo alternativas de uso dentro de la industria química y alimentaria ya que, según estudios realizados, dentro de nuestro país no es aprovechada. Se partió desde el estudio de rendimientos según el lugar y tiempos de recolección, posterior a esto se buscó el tratamiento adecuado como molienda para el manejo óptimo de la muestra, la determinación química (taninos) en vaina y bromatológica (humedad grasa y proteína). Para la determinación química (taninos) se realizó titulación al macerado de la vaina usando índigo carmín y KMnO4 al 0,1 N, mientras que para determinación bromatológica como la humedad, grasa y proteína se aplicó métodos estandarizados de la AOAC 7003, AOAC 7.056 y AOAC 47.021, respectivamente. En los resultados se obtuvo ensayos que demostraron la poca variabilidad del porcentaje de tegumento, endospermo y germen, mientras que en los ensayos de humedad, cantidad de vainas y semillas, taninos, hay variabilidades significativas

Distribution and genetic variability of Staphylinidae across a gradient of anthropogenically influenced insular landscapes

This paper describes the distribution and genetic variability of rove beetles (Coleoptera Staphylinidae) in anthropogenically influenced insular landscapes. The study was conducted in the Azores archipelago, characterized by high anthropogenic influence and landscape fragmentation. Collections were made in five islands, from eight habitats, along a gradient of anthropogenic influence. The species of Staphylinidae from the Azores collected for this study were widely distributed and showed low habitat fidelity. Rove beetle richness was associated with anthropogenic influence and habitat type, increasing from less to more anthropogenic impacted habitats. However, genetic diversity of profiled species (i.e. with three or more specimens per species/habitat) does not seem affected by anthropogenic influence in the different habitat types, isolation or landscape fragmentation. COI haplotypes were, as a rule, not exclusive to a given island or habitat. High level of genetic divergence and nucleotide saturation was found in closely related morphological designated species, demonstrating possible disparities between currently defined taxonomic units based on morphology and molecular phylogenies of Staphylinidae. This study found evidence of cryptic speciation in the Atheta fungi (Gravenhorst) species complex which had thus far remained undetected. Similar trends were found for Oligota parva Kraatz, Oxytelus sculptus Gravenhorst, Oligota pumilio Kiesenwetter. Previous studies with lower taxonomical resolution may have underestimated the biotic diversity reported in the Azores in comparison to other Macaronesian archipelagos.info:eu-repo/semantics/publishedVersio

Running Gluon Mass from Landau Gauge Lattice QCD Propagator

The interpretation of the Landau gauge lattice gluon propagator as a massive type bosonic propagator is investigated. Three different scenarios are discussed: i) an infrared constant gluon mass; ii) an ultraviolet constant gluon mass; iii) a momentum dependent mass. We find that the infrared data can be associated with a massive propagator up to momenta $\sim 500$ MeV, with a constant gluon mass of 723(11) MeV, if one excludes the zero momentum gluon propagator from the analysis, or 648(7) MeV, if the zero momentum gluon propagator is included in the data sets. The ultraviolet lattice data is not compatible with a massive type propagator with a constant mass. The scenario of a momentum dependent gluon mass gives a decreasing mass with the momentum, which vanishes in the deep ultraviolet region. Furthermore, we show that the functional forms used to describe the decoupling like solution of the Dyson-Schwinger equations are compatible with the lattice data with similar mass scales.Comment: Version to appear in J. Phys. G. New version include some rewriting and new analysis. In particular, the section on the running mass is ne

Instanton traces in lattice gluon correlation functions

Strong coupling constant computed in Landau gauge and MOM renormalization scheme from lattice two and three gluon Green Functions exhibits an unexpected behavior in the deep IR, showing a maximum value around $1 {\rm GeV}$. We analise this coupling below this maximum within a semiclassical approach, were gluon degrees of freedom at very low energies are described in terms of the classical solutions of the lagrangian, namely instantons. We provide some new results concerning the relationship between instantons and the low energy dynamics of QCD, by analising gluon two- and three-point Green functions separately and with the help of a cooling procedure to eliminate short range correlations.Comment: 4 pages, talk given at XXXX Rencontres de Moriond on QCD and Hadronic Interactions, La Thuile (Italy

Nanotailoring Stereolithography Resins for Unique Applications using Carbon Nanotubes

Nanostructured materials and exploiting their properties in stereolithography (SL) may open new markets for unique rapidly manufactured functional devices. Controlled amounts of multiwalled carbon nanotubes (MWCNTs) were successfully dispersed in SL epoxy-based resins and complex three-dimensional (3D) parts were successfully fabricated by means of a multi-material SL setup. The effect of the nanosized filler was evaluated using mechanical testing. Small dispersions of MWCNTs resulted in significant effects on the physical properties of the polymerized resin. A MWCNT concentration of .05 wt% (w/v) in DSM Somos® WaterShed™ 11120 resin increased the ultimate tensile stress and fracture stress an average of 17% and 37%, respectively. Electron microscopy was used to examine the morphology of the nanocomposite and results showed affinity between the MWCNTs and SL resin and identified buckled nanotubes that illustrated strong interfacial bonding. These improved physical properties may provide opportunities for using nanocomposite SL resins in end-use applications. Varying types and concentrations of nanomaterials can be used to tailor existing SL resins for particular applications.Mechanical Engineerin