Gutzwiller variational approach to the two-impurity Anderson model at particle-hole symmetry

We study Gutzwiller-correlated wave functions as variational ground states for the two-impurity Anderson model (TIAM) at particle-hole symmetry as a function of the impurity separation ${\bf R}$. Our variational state is obtained by applying the Gutzwiller many-particle correlator to a single-particle product state. We determine the optimal single-particle product state fully variationally from an effective non-interacting TIAM that contains a direct electron transfer between the impurities as variational degree of freedom. For a large Hubbard interaction $U$ between the electrons on the impurities, the impurity spins experience a Heisenberg coupling proportional to $V^2/U$ where $V$ parameterizes the strength of the on-site hybridization. For small Hubbard interactions we observe weakly coupled impurities. In general, for a three-dimensional simple cubic lattice we find discontinuous quantum phase transitions that separate weakly interacting impurities for small interactions from singlet pairs for large interactions.Comment: 24 pages, 10 figures, submitted to J. Phys. Cond. Mat

Spatial energy predictions from large-scale photovoltaic power plants located in optimal sites and connected to a smart grid in Peninsular Malaysia

In order to make accurate energy predictions for large-scale photovoltaic (PV) systems connected to a smart grid, it is first necessary to identify the very specific locations that are required for their long-term optimal operation. Multi-criteria evaluation techniques are often applied for different site selection studies. This study discusses the past, present and future condition of solar PV application in Malaysia. The study also uses the optimal site definition model (ODM) and GIS to select sites for the installation of large-scale PV power plants that will be connected to a smart grid, and to predict their technical potential and carbon emission reduction, based on optimal sites in Peninsular Malaysia. The outcome of the study reveals that policies and strategies being adopted by Malaysia government are significantly improving the solar PV application for energy sustainability. However, on the other aspect, the results show that 10,092.08 km2 (7.64%) of the area under study is suitable for large-scale PV plant installation. If even half of the potential sites are used, with an installed capacity of 756.91 GW, we predict a total electricity generation potential of 1,343,527.9 GWh/yr with an annual carbon emission reduction of 846,422.56 kt-CO2/yr in Peninsular Malaysia. Based on predicted national energy consumption in 2030, this study shows that about 8 times future annual energy consumption could be met if PV plants with an installed capacity of 756.91 GW are set up in Peninsular Malaysia. Similarly, the study predicts an improvement of 1.6 times the annual carbon emission reduction, based on predicted carbon emissions for 2020. Therefore, the implementation of large-scale PV applications is technically and environmentally viable in Peninsular Malaysia and tropical countries as a whole

Comparative ultrastructural hepatic alterations induced by free and liposome-encapsulated mefenamic acid

Mefenamic acid (MFA) is used as an anti-inflammatory, antinociceptive, and antipyretic agent for treatment of a wide range of pathological disorders. While the uncertainty of its safety and the poor oral bioavailability constitute the major limiting factors of its medical use, considerable efforts including liposomal encapsulation are needed to achieve maximum therapeutic advantages. The current work was conducted to investigate the ultrastructural alterations in the liver induced by free MFA and its liposomal preparation. Female Sprague-Dawley rats were treated with daily oral doses of either free MFA or MFA entrapped in Tween 80 inoculated liposomes at the concentration of 80 mg/kg for 28 days. Ultrathin sections were prepared from biopsies taken from the liver of each member of all animals under study and subjected to examination by transmission electron microscopy. The liver of rats that were exposed to liposomal MFA showed more ultrastructural alterations than the rats treated with the free drug. While both groups of rats demonstrated sinusoidal dilatation, Kupffer cell hyperplasia, mitochondrial damage, and nuclear alterations, rats treated with liposome-encapsulated MFA induced an increase in the multiple lysosomes formation, hepatocytic steatosis, and apoptotic activity than free MFA-treated rats. The ultrastructural findings of the present study indicate that the use of liposomal MFA induces more hepatic damage than the use of free MFA

A cognotive stylistic analysis of a selection of contemporary egyptian novels

[ES] Esta tesis doctoral ofrece un comprensivo análisis cognitivo de tres novelas egipcias de autores contemporáneos: Book of Sands (2015) de Karim Alrawi; Taxi (2016) de Khalid Al Khamissi y The Day the Leader Was Killed (1985) de Naguib Mahfouz. Mediante la implementación de los marcos teóricos de Text World Theory (Werth, 1999; Gavins, 2007) y Blending Theory (también conocida en español como la teoría de integración conceptual) (Fauconnier and Turner, 2002), esta tesis persigue tres objetivos principales. En primer lugar, demostrar cómo la Text World Theory ayuda al lector a entender la narración como una estructura conceptual constituida por tres capas conceptuales interrelacionadas: the discourse-world, text-worlds y sub-worlds. En segundo lugar, evidenciar el papel fundamental que desempeña la Blending Theory en la correcta interpretación de metáforas a nivel de oración, además de exponer cómo la ironía y el humor que surge de la colisión de elementos incongruentes en estos constructos metafóricos se utilizan para criticar aspectos políticos y socio-culturales presentes en Egipto. Por ultimo, esta tesis busca ilustrar cómo la combinación de la Text World Theory y Blending Theory representa un método efectivo que permite entender las novelas desde niveles micro y macro textuales. Para este fin, se ha seleccionado la Text World Theory como marco discursivo para el macroanálisis de Book of Sands, mientras que la Blending Theory se ha utilizado para el análisis detallado de metáforas a nivel oracional en Taxi. Estos análisis revelan que cada una de las teorías aborda aspectos específicos del texto literario, poniendo en valor su combinación como una estrategia efectiva que comporta una investigación holística de las novelas egipcias seleccionadas, exponiendo así sus complejidades e intersecciones. Por este motivo, ambas aproximaciones se han integrado en el análisis de The Day the Leader Was Killed. Esta integración ha demostrado ser una herramienta de análisis útil al permitir, tanto al lector nacional como internacional, la comprensión completa de la narración y la revelación de mensajes ocultos y realidades encubiertas de la sociedad egipcia

Liposome encapsulation: a promising approach to enhanced and safe mefenamic acid therapy

Mefenamic acid (MEF) is a non-steroidal anti-inflammatory drug (NSAID) characterized by low bioavailability with relative high toxicity. Despite the efforts which have been paid to enhance its bioavailability, its inherent toxicity remains the limiting factor for its medical uses. Designing MFE as a prodrug of ester derivatives can attenuate gastrointestinal (GI) toxicity, but shows no advantages in term of therapeutic efficacy. Liposomes have a dual action and would be a promising tool to enhance MFE bioavailability and reduce its gastric and systemic adverse reactions. This review covers the pharmacological and toxicological aspects of MFE and provides substantial trend to enhance its clinical therapy

Special track on handheld computing

Handheld computing is an emerging mobile computing paradigm that promotes using handheld wireless devices (or mobile devices) such as cellular phones and Personal Digital Assistants (PDAs) to accomplish various computing tasks. As handheld devices continue to appear in many forms with diverse functionalities, handheld computing will become the dominant computing paradigm in many fields including education, enterprises, and healthcare

Engineering Wireless Mobile Applications

Conventional desktop software applications are usually designed, built, and tested on a platform similar to the one on which they will be deployed and run. Wireless mobile application development, on the other hand, is more challenging because applications are developed on one platform (like UNIX or Windows) and deployed on a totally different platform like a cellular phone. While wireless applications can be much smaller than conventional desktop applications, developers should think in the small in terms of the devices on which the applications will run and the environment in which they will operate instead of the amount of code to be written. This paper presents a systematic approach to engineering wireless application and offers practical guidelines for testing them. What is unique about this approach is that it takes into account the special features of the new medium (mobile devices and wireless networks), the operational environment, and the multiplicity of user backgrounds; all of which pose new challenges to wireless application development. © 2009, IGI Global

Special track on handheld computing

Handheld computing is an emerging mobile computing paradigm that promotes using handheld wireless devices (or mobile devices) such as cellular phones and Personal Digital Assistants (PDAs) to accomplish various computing tasks. As handheld devices continue to appear in many forms with diverse functionalities, handheld computing will become the dominant computing paradigm in many fields including education, enterprises, and healthcare

Engineering Wireless Mobile Applications

Conventional desktop software applications are usually designed, built, and tested on a platform similar to the one on which they will be deployed and run. Wireless mobile application development, on the other hand, is more challenging because applications are developed on one platform (like UNIX or Windows) and deployed on a totally different platform like a cellular phone. While wireless applications can be much smaller than conventional desktop applications, developers should think in small terms of the devices on which the applications will run and the environment in which they will operate instead of the amount of code to be written. This chapter presents a systematic approach to engineering wireless applications and offers practical guidelines for testing them. What is unique about this approach is that it takes into account the special features of the new medium (mobile devices and wireless networks), the operational environment, and the multiplicity of user backgrounds; all of which pose new challenges to wireless application development. © 2008, IGI Global