727 research outputs found
A polymer based sensor for phosphate detection in water
This paper presents the detection of phosphate (PO4-3) concentration in water by using a commercial quartz crystal microbalance (QCM) sensor that was coated with a novel polymeric affinity layer for the first time. The QCM sensor was exposed to PO4-3 and chloride (Cl-) solutions in various concentrations to investigate the sensitivity of the affinity layer. Changes in the viscosity of a solution, and weak binding of ions onto the polymeric layer eliminated the effect of PO4-3 binding to the polymer and hardened the concentration detection. Therefore, we have proposed a new method in which an intermediate Cl- solution is applied before introducing the PO4-3 solution to detect the concentration level in a continuous flow
Vortex solutions in the noncommutative torus
Vortex configurations in the two-dimensional torus are considered in
noncommutative space. We analyze the BPS equations of the Abelian Higgs model.
Numerical solutions are constructed for the self-dual and anti-self dual cases
by extending an algorithm originally developed for ordinary commutative space.
We work within the Fock space approach to noncommutative theories and the
Moyal-Weyl connection is used in the final stage to express the solutions in
configuration space.Comment: 18 pages, 5 figure
Non-Abelian Vortices on the Torus
We study periodic arrays of non-Abelian vortices in an
gauge theory with flavors of fundamental matter multiplets. We carefully
discuss the corresponding twisted boundary conditions on the torus and propose
an ansatz to solve the first order Bogomolnyi equations which we find by
looking to a bound of the energy. We solve the equations numerically and
construct explicit vortex solutions
Bogomolny equations for vortices in the noncommutative torus
We derive Bogomolny-type equations for the Abelian Higgs model defined on the
noncommutative torus and discuss its vortex like solutions. To this end, we
carefully analyze how periodic boundary conditions have to be handled in
noncommutative space and discussed how vortex solutions are constructed. We
also consider the extension to an model, a simplified
prototype of the noncommutative standard model.Comment: 23 pages, no figure
OC-0480: External radiation therapy, extended surgery and intraoperative electrons for oligorrecurent pelvic cancer
Conformal Partial Wave Expansions for N=4 Chiral Four Point Functions
The conformal partial wave analysis of four point functions of half BPS
operators belonging to the SU(4) [0,p,0] representation is undertaken for
p=2,3,4. Using the results of N=4 superconformal Ward identities the
contributions from protected short and semi-short multiplets are identified in
terms of the free field theory. In the large N limit contributions
corresponding to long multiplets with twist up to 2p-2 are absent. The
anomalous dimensions for twist two singlet multiplets are found to order g^4
and agree with other perturbative calculations. Results for twist four and six
are also found.Comment: 53 pages, uses harvmac, includes 1 figure, version 2 some corrections
and minor extensions, version 3 some further corrections, version 4 as to be
publishe
Superconformal Symmetry, Correlation Functions and the Operator Product Expansion
Superconformal transformations are derived for the \N=4\N=2$ or 4
superconformal identities are derived for the functions of the two conformal
invariants appearing in the four point function for the chiral primary
operator. These are solved in terms of a single arbitrary function of the two
conformal invariants and one or three single variable functions. The results
are applied to the operator product expansion using the exact formula for the
contribution of an operator in the operator product expansion in four
dimensions to a scalar four point function. Explicit expressions representing
exactly the contribution of both long and possible short supermultiplets to the
chiral primary four point function are obtained. These are applied to give the
leading perturbative and large N corrections to the scale dimensions of long
supermultiplets.Comment: 75 pages, plain TeX file using harvmac; revised version, minor
corrections and extra referenc
Evaluación de la tolerancia a estrés salino en genotipos novedosos de Buffel Grass (Cenchrus Ciliaris L.)
Poster y resumenEn Argentina, los suelos de ambientes cálidos áridos y semiáridos, se reportan como uno de los más afectados por sales en el perfil. El INTA viene realizando programas de mejoramiento genético en especies forrajeras subtropicales, particularmente en Cenchrus ciliaris L. (buffel grass), una gramínea de gran importancia por su notoria tolerancia a estrés
hídrico, fácil implantación y capacidad de mejorar las condiciones físicas del suelo.Instituto de Fisiología y Recursos Genéticos VegetalesFil: Gonzalez, M. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas; ArgentinaFil: García Seleme, F.A. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias; ArgentinaFil: Hernandez Alvarez, Urys Mileth. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Estudios Agropecuarios (UDEA); ArgentinaFil: Hernandez Alvarez, Urys Mileth. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Fisiología y Recursos Genéticos Vegetales; ArgentinaFil: Lopez Colomba, Eliana. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Fisiología y Recursos Genéticos Vegetales; ArgentinaFil: Lopez Colomba, Eliana. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Estudios Agropecuarios (UDEA); ArgentinaFil: Lopez Colomba, Eliana. Universidad Católica de Córdoba. Facultad de Ciencias Agropecuarias; Argentin
PWM-based Flux linkage estimation for permanent magnet synchronous machines
Monitoring of rotor temperature in permanent magnet
synchronous machines (PMSM) is of great importance as high
temperature could cause partial or even irreversible
demagnetization of the permanent magnets. Rotor temperature
measurement unfortunately is particularly difficult in practice,
since it is difficult to access temperature sensors on a rotating
shaft. Nevertheless, rotor temperature can be obtained
indirectly with the information of rotor magnet flux linkage, as
permanent magnet (PM) remanence decreases with rotor
temperature. In this paper, a simple and relatively accurate
method for online estimation of PM flux linkage is presented,
based on the measurement of current response to the standard
space-vector pulse width modulation (SV-PWM). This method
uses the already-existing PWM voltage as the excitation signal
in order to avoid any form of signal injection which produces
undesirable disturbance to the system. Knowledge of machine
parameters, such as inductances which may vary due to
saturation, is not required. The proposed methodology has been
verified in real-time simulation
Cirugía derivativa más radioterapia intraoperatoria y externa en el carcinoma de páncreas localizado e irresecable
Presentamos una serie de 25 casos de carcinomas de páncreas localmente avanzados e irresecables, sin metástasis a distancia, tratados con cirugía derivativa, radioterapia intraoperatoria e irradiación externa: 18 tumores de cabeza (16 con ictericia obstructiva) y 7 de cuerpo. Se realizó derivación biliar en 18 y gastroyeyunostomía en 19. La mortalidad operatoria fue nula, con una morbilidad del 16%. A largo plazo se produjeron 3 hemorragias digestivas, 2 ictericias obstructivas, una colangitis y una obstrucción intestinal. Se obtuvo un 72% de control local de la enfermedad y todos los fallecidos por progresión tumoral desarrollaron metástasis hepáticas y/o peritoneales. Presentaban dolor pancreático 22 pacientes y 20 experimentaron remisión del mismo en una a 2 semanas. La analgesia fue definitiva en 12 y reapareció el dolor tardíamente en ocho. La supervivencia media fue de 9 meses (rango 4-24). La revisión de la literatura pone de manifiesto la indicación de la radioterapia externa tanto en el carcinoma de páncreas irresecable y no metastásico como en los resecados. La asociación de radioterapia intraoperatoria tiene, así mismo, un papel importante en cuanto a supervivencia, paliación del dolor y de la progresión local. El 5-fluorouracilo asociado al tratamiento radioterápico prolonga significativamente la supervivencia con una morbilidad razonable
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