Dynamic compensation in the central Pacific Ocean

The intermediate-wavelength geoid (lambda similar to 2000 km) and sea-floor topography fields in the central Pacific Ocean were studied in terms of static and dynamic compensation models. Topographic features on the sea-floor with lambda less than 1000 km were found to be compensated both regionally, by the elastic strength of the lithosphere, and locally, by displacing mantle material to reach isostatic adjustment. The larger-scale sea-floor topography and the corresponding geoid anomalies with lambda similar to 2000 km cannot be explained by either local or regional compensation. The topography and the resulting geoid anomaly at this wavelength were modeled by considering the dynamic effects arising from viscous stresses in a layer of fluid with a highly temperature-dependent viscosity for the cases of: (1) surface cooling, and (2) basal heating. In this model, the mechanical properties of the elastic part of the lithosphere were taken into account by considering an activation energy of about 520 kJ/mol in the Arrhenius law for the viscosity. Numerical predictions of the topography, total geoid anomaly, and admittance were obtained, and the results show that the thermal perturbation in the layer, which accounts for the mass deficit, must be located close to the surface to compensate the gravitational effect of the surface deformation. For the case of basal heating, the temperature dependence of viscosity results in a separation of the upper, quasi-rigid lid from the lower mobile fluid, hence inhibiting the development of a compensating thermal perturbation at shallow depths. The results clearly rule out small-scale, upper-mantle convection as the source of these anomalies. Instead, the geophysical observables can be well explained by a shallow, transient thermal perturbation

Dinámicas provinciales de bienestar en Bolivia

Este informe de investigación presenta los resultados de un ejercicio de microsimulación que busca conocer la orientación de los cambios en indicadores de bienestar (gasto per cápita, pobreza y desigualdad) en Bolivia y mapear tales cambios en el territorio nacional, a fin de identificar las desigualdades espaciales en la distribución del crecimiento y el desarrollo ocurrido en el período intercensal 1992 – 2001 a nivel de unidades geográficas pequeñas. La caracterización de dinámicas provinciales, en base a una tipología construida a partir de la combinación de indicadores de bienestar obtenidos mediante el método de Estimación en Áreas Pequeñas (SAE) en la aplicación propuesta por Elbers y otros (2003), permitió mostrar que durante el período analizado se han generado diversas dinámicas de desarrollo territorial rural en casi todo el territorio nacional que cuestionan las apreciaciones de que en Bolivia se habrían generado procesos territoriales dicótomos de un grupo de regiones „ganadoras‟ y otro de „perdedoras‟. Los resultados de este trabajo muestran también que entre los impactos de las políticas de ajuste implementadas desde 1985 y de las reformas estructurales de la década de 1990 – dentro de las cuales los procesos de descentralización y de participación popular resultarían fundamentales – se tiene que contar no solo el cambio en indicadores económicos y de desarrollo sino también una cierta re-configuración del territorio nacional en su conjunto y del espacio rural en particular. Son estos cambios los que – al menos en parte – ayudarían a explicar el desarrollo subsiguiente de movimientos sociales y políticos territorializados que se observaron desde inicios de 2000. Así, si bien se puede observar una mejora casi generalizada en términos de incremento de gasto, reducción de pobreza y reducción de desigualdad en casi todas las regiones del país, los procesos positivos más marcados en varias de las regiones llanas del „Oriente‟ (particularmente en los departamentos de Tarija y Santa Cruz y en los valles de Cochabamba y La Paz), se contrastan a aquellos de zonas menos dinámicas dentro de estos propios departamentos y otros como Chuquisaca, Beni y Pando; y, con mayor claridad, se distinguen de las áreas altiplánicas más rezagadas de los departamentos de Oruro y Potosí. Nuevamente, como hipótesis, tales desigualdades territoriales – presentes aun dentro de un contexto de avance más o menos generalizado – estarían influenciando la tensa búsqueda de nuevos paradigmas de desarrollo que ha caracterizado a Bolivia en la presente década. Revelar los factores que explican el porqué del desarrollo territorial diferenciado es, precisamente, el objetivo de la segunda fase de investigación a la cual el mapeo de dinámicas provinciales de bienestar da base

Broad band electromagnetic characterization method of nematic liquid crystals using a coplanar waveguide

A broad band electromagnetic extraction method of the dielectric tensor for nematic liquid crystals, associated to a measuring cell, is presented. The dielectric tensor is computed from S-parameter measurements obtained at the input planes of a coplanar waveguide supporting the nematic liquid crystal to be characterized, which is used as measuring cell. The extraction method of the dielectric tensor is based on the propagation of the dominant mode in the measuring cell. It is fast and easy. It uses analytical relationships, which are presented in this paper. The simulations results have demonstrated the validity of this extraction method in the 1GHz-40GHz frequency range for the electromagnetic characterization of nematic liquid crystals.J. Hinojosa is grateful to Ministerio de Ciencia y Technología and Region de Murcia Fundación Séneca of Spain for the grants TIC2002-01266 and PB/39/FS/02, which have allowed the present research activity

La fiscalidad de la inteligencia artificial en el marco de la llamada economía colaborativa

El trabajo analiza las cuestiones que afectan a la fiscalidad de las formas de conomía social que suponen el desarrollo de servicios digitales, en particular de la llamada economía colaborativa mediante el uso o la mediación de plataformas digitales gestionadas por terceros.Universidad de Málaga. Campus de Excelemncia Internacional Andalucía Tech

Double-sided open split ring resonator for compact microstrip band-pass filter design

A metamaterial structure, called the double-sided open split ring resonator (DOSRR), which combines two open split ring resonators (OSRRs) aligned over the opposite faces of the substrate in an inverted fashion is presented. A study of this resonator from full-wave electromagnetic and circuit simulations is performed. As with the OSRR cell, the DOSRR cell allows a series connection along a microstrip transmission line and it has a small electrical size. Moreover, the DOSRR cell has the ability to add a transmission zero in the out-of-band region without increasing its size. This DOSRR cell is used for the design of compact microstrip slow-wave type band-pass filters. Two strategies based on circular windows etched in the bottom plane instead of square windows and U-shape slots etched in the microstrip transmission line are designed to increase the stop band and to add extra zeros in order to suppress the spurious band. The experimental results have confirmed the possibilities of this electrically small resonator (DOSRR) and the efficiency of both strategies to improve the out-of-band rejection.The authors gratefully acknowledge Ministerio de Ciencias e Innovación of Spain for financial support of this work under the grant no.: TEC2010-21520-C04-04/TCM

Shunt series LC circuit for compact coplanar waveguide notch filter design

A shunt series LC resonant circuit based on an open version of an interconnected split ring resonator (OISRR) is proposed. This OISRR exhibits half the resonant frequency of the split ring resonator, allows a parallel connection with a coplanar waveguide (CPW) section and according to its frequency response is an attractive cell for compact CPW notch filter design. 3 dB stop-band bandwidth lower than 4.5% with more than 11 dB insertion loss in the stop-band can be achieved with a CPW loaded with a single OISRR. The experimental results have confirmed the possibilities of this OISRR, which can be easily connected to CPW antennas to reject undesirable signalsThe authors gratefully acknowledge Ministerio de Ciencias e Innovación of Spain and FEDER for the financial support of this work under the grant no.: TEC2010‐21520‐C04‐04/TCM

Multiple adaptive neuro-fuzzy inference systems for accurate microwave CAD applications

An approach for applying fuzzy logic for accurate CAD of microwave circuits is presented. Our proposed method combines space-mapping (SM) technology and multiple adaptive neuro-fuzzy inference systems (MANFIS) for the modeling of microwave devices. MANFIS is trained to predict a nonlinear vector multidimensional mapping function, which is obtained from SM approach. Optimization by micro-genetic algorithm is used to find nonlinear vector multidimensional mapping function for singular systems. This approach is applied to a shielded microstrip line within a region of interest. The parameter values (ε reff ( f ) , Zc ( f )) computed with our proposed method are in excellent agreement with those obtained from electromagnetic simulations

An Optimization Technique for Ranch Management

Water is a scarce resource; it is a vital resource in the production of crops for livestock that will directly impact supply chain costs. Many costs occur in poorly deployed irrigation systems that don’t fully utilize land potential, thereby, not produce the proper yield of crops for livestock. An irrigation system can not only reduce initial set up and maintenance costs but reduces land waste while increasing yield of dry matter feed. This research presents a cost benefit analysis approach to determine the practicability of installing an irrigation system onto 54 acres of ranch land by employing the use of linear programming. Specifically, by examining factors that impact costs and production, a generalized model was developed to better understand how this system works on any ranch. These results indicate by optimizing land to its fullest capacity for dry matter, one can then maximize profits generated. This research found the profitability of employing an irrigation system is beneficial even at lower production yields when compared to land with no irrigation system