An investigation on the preparation and properties of some transparent conducting oxides and lead selenide thin films”

The investigation of physical properties of matter has progressed so much during the last hundred years. Today physics is divided in to a large distinct group of special branches. These branches are distinguished by the particular area studied, method of investigation and so on. An independent and important branch that has developed is the physics ofthin films.Any object in solid or liquid form with one of its dimensions very much smaller than that of the other two may be called a thin film. It is having only one common property, namely, one of their dimensions is very small, though all their physical properties may be different. Thin layers of oil, floating on the surface of water, with their fascinating colours, have attracted men’s curiosity from time immemorial. The earliest application of thin films was the protective coatings in the form of paints. A thin layer of tin has been used from ancient times to protect copper utensils from corrosion. Indium thin films are used in certain applications on account of their good lubricating property. Relay contacts are coated with thin films of rare earth metals in order to prevent burning due to arcing. Hard coatings are also available using diamond like carbon (i-carbon). The basic properties of thin films are of considerable interest because of their potential applications in various fields of science and technology

Determination of charge carrier transport in radio frequency plasma polymerized aniline thin films

The carrier transport mechanism of polyaniline (PA) thin films prepared by radio frequency plasma polymerization is described in this paper. The mechanism of electrical conduction and carrier mobility of PA thin films for different temperatures were examined using the aluminium–PA–aluminium (Al–PA–Al) structure. It is found that the mechanism of carrier transport in these thin films is space charge limited conduction. J –V studies on an asymmetric electrode configuration using indium tin oxide (ITO) as the base electrode and Al as the upper electrode (ITO–PA–Al structure) show a diode-like behaviour with a considerable rectification ratio

Fabrication of a quantum well heterostructure based on plasma polymerized aniline and its characterization using STM/STS

Two-dimensional electronic systems play a crucial role in modern electronics and offer a multitude of opportunities to study the fundamental phenomena at low dimensional physics. A quantum well heterostructure based on polyaniline (P) and iodine doped polyaniline (I) thin films were fabricated using radio frequency plasma polymerization on indium tin oxide coated glass plate. Scanning probe microscopy and scanning electron microscopy studies were employed to study the morphology and roughness of the polymer thin films. Local electronic density of states (LDOS) of the P–I–P heterostructures is probed using scanning tunnelling spectroscopy (STS). A step like LDOS is observed in the P–I–P heterostructure and is attributed to the quantum well confinement of electrons in the polymer heterostructure.

Energy bandstructureinvestigationofblueandgreenlightemitting Mg dopedSnO2 nanostructuressynthesizedbycombustionmethod

Tin oxide(SnO2) andMgdoped(2,4,6,and8wt%)SnO2 nanoparticles weresynthesizedbytheself- propagating solutioncombustionsynthesisusingcitricacidasfuel.Thecharacterizationofsampleswas done byX-raydiffractionspectroscopy(XRD),transmissionelectronmicroscopy(TEM),UV–visible spectroscopy,SAEDandphotoluminescence(PL).XRDpatternandTEMstudiesshowthatthe synthesized particlesareofaveragesize30nmandtheyareintetragonalrutilestructureofSnO2. Combined blueandgreenemissionisseenin4wt%MgdopedSnO2 and intensityofbluebandis increased withrespecttoincreaseinMgdopantconcentrationwhichisattributedtoincreasein population ofoxygenvacancies.ThePLemissioninblueandgreenregionisduetothedoublycharged state (Vo 2þ) ofoxygenandtininterstitialdefectsrespectivelyandisexplainedwithanenergyband diagram

Dezincification of Epoxy Coated Brass in Cochin Estuary, India

Inhibited α brasses are largely immune to dezincification in most water, but the effect of tin and arsenic addition to α/β brasses is not so reliable or predictable in controlling the problem. There have been many cases of dezincification in duplex brasses in both fresh water and seawater. There is no reliable method of inhibiting the dezincification of two-phase brass despite there are some protection methods such as inhibitors, electro deposition and electro polymerization. Organic coatings are effectively used for the protection of metals due to their capacity to act as a physical barrier between the metal surface and corrosive environment. Hence, epoxy coating on brass was applied and effect of this against dezincification in Cochin estuarine water over a period of one year was studied and reported in this paper

Optimization of parameters of chemical spray pyrolysis technique to get n and p-type layers of SnS

SnS thin films were prepared using automated chemical spray pyrolysis (CSP) technique. Single-phase, p-type, stoichiometric, SnS films with direct band gap of 1.33 eV and having very high absorption coefficient (N105/cm) were deposited at substrate temperature of 375 °C. The role of substrate temperature in determining the optoelectronic and structural properties of SnS films was established and concentration ratios of anionic and cationic precursor solutions were optimized. n-type SnS samples were also prepared using CSP technique at the same substrate temperature of 375 °C, which facilitates sequential deposition of SnS homojunction. A comprehensive analysis of both types of films was done using x-ray diffraction, energy dispersive x-ray analysis, scanning electron microscopy, atomic force microscopy, optical absorption and electrical measurements. Deposition temperatures required for growth of other binary sulfide phases of tin such as SnS2, Sn2S3 were also determined

Electronic structure of UF_5

Non-relativistic and relativistic self-consistent Hartree- Fock-Slater and Dirac-Slater models have been used to calculate one-electron energy levels and ionization energies for UF_5. The calculations were performed in an assumed structure of C_4v symmetry with the uranium atom at the center of mass of the molecule. The spacing and level ordering are compared with earlier results obtained with the MS X\alpha method using the muffin-tin approximation. Connections with the multiphoton isotope separation scheme of UF_6 are discussed.

Tubular Organization of SnO₂ Nanocrystallites for Improved Lithium Ion Battery Anode Performance

Porous tin oxide nanotubes were obtained by vacuum infiltration of tin oxide nanoparticles into porous aluminum oxide membranes, followed by calcination. The porous tin oxide nanotube arrays so prepared were characterized by FE-SEM, TEM, HRTEM, and XRD. The nanotubes are open-ended, highly ordered with uniform cross-sections, diameters and wall thickness. The tin oxide nanotubes were evaluated as a substitute anode material for the lithium ion batteries. The tin oxide nanotube anode could be charged and discharged repeatedly, retaining a specific capacity of 525 mAh/g after 80 cycles. This capacity is significantly higher than the theoretical capacity of commercial graphite anode (372 mAh/g) and the cyclability is outstanding for a tin based electrode. The cyclability and capacities of the tin oxide nanotubes were also higher than their building blocks of solid tin oxide nanoparticles. A few factors accounting for the good cycling performance and high capacity of tin oxide nanotubes are suggested.

El entorno : la localidad

Libro elaborado por un grupo de maestros de las escuelas rurales con el que se quiere aportar una visi??n distinta del entorno, trat??ndolo desde el medio rural se quiere dar una ayuda al maestro en su tarea de investigaci??n en el aula. Se contemplan los siguientes apartados: Situaci??n de mi localidad; medios de transportes y v??as de acceso; viviendas y edificios; poblaci??n; servicios y zonas de recreo; econom??a; cultura; geograf??a del entorno y ecolog??a del entorno. Cada apartado consta de los siguientes puntos: objetivos, contenidos, actividades y bibliograf??a para preescolar, ciclo inicial y ciclo medio.

Plantas medicinales

Trata de aportar una ayuda al profesor en su tarea de investigaci??n en el aula. Seg??n los autores no se trata de una labor acabada. Tratan de facilitar el conocimiento del entorno natural del ni??o y se hace una relaci??n de plantas medicinales ordenadas alfab??ticamente en la que se incluye un dibujo de la planta, su nombre en castellano, en asturiano, una descripci??n de la planta, d??nde se encuentra, qu?? parte se usa, cu??ndo se recolecta, cu??ndo florecen y cu??l es su acci??n curativa y su uso. Se describen 48 plantas y se ofrece una bibliograf??a b??sica sobre flores, ??rboles, arbustos y medicina natural.

Plantas medicinales

Los objetivos del proyecto son facilitar el conocimiento del entorno natural del ni??o y crear un libro de texto sobre el tema adecuado a preescolar, ciclo inicial y ciclo medio. Se trata de elaborar una gu??a del profesor con plantas medicinales, objeto de estudio. Cada ficha contiene: descripci??n, presencia, parte usada, recolecci??n, floraci??n y acci??n curativa y uso. En el proyecto se contempla tambi??n la elaboraci??n de una gu??a para los alumnos con fichas de actividades complementarias adecuadas para los niveles ya citados que contenga: lecturas, fichas, experiencias y un estudio interdisciplinar. La memoria s??lo refleja la primera parte del proyecto e incluye una bibliograf??a sobre el tema tratado.

El entorno: la localidad. El entorno: la localidad. Estudio interdisciplinar

El objetivo del trabajo es facilitar el conocimiento del entorno natural del ni??o y crear un libro de texto sobre el tema adecuado para preescolar, ciclo inicial y medio. Se trata de una gu??a con fichas de actividades adecuadas a cada nivel en la que aparecen un itinerario y material de trabajo para el alumno. Con la edici??n del libro pretenden aportar una ayuda al maestro en su tarea de investigaci??n en el aula. No se trata de una labor acabada y como tal, sostienen los autores, debe entenderse. En la memoria se recogen los objetivos, contenidos, actividades y bibliograf??a para Preescolar, Ciclo Inicial y Ciclo Medio.

Diseño instruccional en los lenguajes de modelado educativo.

Resumen tomado del autor. Artículo seleccionado de SINTICE (Simposio Nacional de las Tecnologías de la Información y las Comunicaciones en la Educación), VI Congreso Nacional de Informática Educativa (Granada 2005), extendido y revisado para su publicación en IE Comunicaciones. El Ministerio de Educación y Ciencia ha contribuído a este trabajo a través del proyecto 'MetaLearn: metodologías, arquitecturas y lenguajes para sistemas E-learning adaptativos' TIN 2004-08367-C02-01

Un modelo de distribución de repositorios para un portal de comunidades de aprendizaje colaborativo.

Resumen tomado de la publicación. Artículo seleccionado de SINTICE (Simposio Nacional de las Tecnologías de la Información y las Comunicaciones en la Educación), VI Congreso Nacional de Informática Educativa (Granada 2005), extendido y revisado para su publicación en IE Comunicaciones. Este artículo es una versión revisada y extendida del artículo presentado en el CEDI (Congreso Español de Informática) 2005 de Granada. El trabajo relatado en este artículo ha sido desarrollado dentro del proyecto europeo COLDEX (IST-2001-32327) y continuará desarrollándose dentro del marco que aporta el proyecto nacional ENLACE (TIN 2004-04232)

Herramienta Autor para la gesti??n de tests informatizados dentro del sistema AHA!

Resumen tomado del autor. Este trabajo ha sido financiado por el proyecto TIN 2005-08386-C05-02 y los fondos FEDER