Search results for "Toe"

Suur****kerhon jälkeenjääneet paperit

2020

Study of periodic Dielectric Frequency-Selective Surfaces under 3D plane wave incidence

2016

A periodic Dielectric Frequency-Selective Surface (DFSS) is studied under 3D plane-wave incidence, whose unit cell in the periodic direction is composed of a dielectric grating and a homogeneous dielectric layer. The structure is excited by a linearly polarized plane-wave. The procedure for computing the Brillouin diagram of the structure under 2D plane-wave incidence with TE or TM polarization was already described by the authors, and the extension to the 3D incidence case has been performed in a similar way. Following the same formalism, it has been obtained the Generalized Scattering Matrix (GSM) of one period of the infinite periodic lattice. This requires the knowledge of the modal spe…

Optical Plasma Diagnostics During Reactive Magnetron Sputtering

2008

Electrical transduction in phthalocyanine-based gas sensors: from classical chemiresistors to new functional structures

2009

Phthalocyanines are organic-based materials which have attracted a lot of research in recent times. In the field of sensors, they present interesting and valuable potentialities as sensing elements for real gas sensor applications. In the present article, and taking some of our experiments as representative examples, we review the different ways of transduction applied to such applications. Some of the new tendencies and transducers for gas sensing based on phthalocyanine derivatives are also reported. Among them, electrical transduction (resistors, field-effect transistors, diodes, etc.) has been, historically, the most commonly exploited way for the detection and/or quantification of gas…

Dichroic atomic vapor laser lock with multi-gigahertz stabilization range

2016

A dichroic atomic vapor laser lock (DAVLL) system exploiting buffer-gas-filled millimeter-scale vapor cells is presented. This system offers similar stability as achievable with conventional DAVLL system using bulk vapor cells, but has several important advantages. In addition to its compactness, it may provide continuous stabilization in a multi-gigahertz range around the optical transition. This range may be controlled either by changing the temperature of the vapor or by application of a buffer gas under an appropriate pressure. In particular, we experimentally demonstrate the ability of the system to lock the laser frequency between two hyperfine components of the $^{85}$Rb ground state…

Molybdenum deposition on TiO2 (110) surfaces with different stoichiometries

1999

Abstract The deposition of ultra thin molybdenum films has been carried out on three different TiO 2 surfaces: a stoichiometric and flat one obtained after annealing, a non stoichiometric and rough surface made by Ar + bombardment and a stoichiometric and rough surface obtained by oxygen bombardment. Whatever the substrate preparation, in situ AES and XPS studies and ex situ AFM and RHEED characterizations have revealed a Stranski–Krastanov growth mode: the completion of three monolayers followed by island growth is observed in any case. The three monolayers are composed of amorphous molybdenum oxide with a molybdenum oxidation state between III and IV. The oxidation of the molybdenum layer…

Ex situ investigations of MOCVD-grown gallium nitride nanowires using reflection high energy electron diffraction

2011

Vertically oriented nanowires (NWs) of single-crystalline wurtzite GaN have been fabricated on sapphire substrates, via metal organic chemical vapor deposition (MOCVD). We present ex situ investigations on orientation and structure of grown GaN nanowires on GaN(0001) surface using reflection high energy electron diffraction (RHEED). Both ordered and randomly oriented GaN crystalline structures have been detected.

Influence of the Chemical Composition and Electronic Structure of Passive Films Grown on 316L SS on Their Transient Electrochemical Behavior

2004

Modifications of the passive film formed on 316L stainless steel (SS) in acidic media were performed under dc or ac polarization. The effects of these ageing treatments on the chemical composition and the electronic structure of the passive film were studied. Chemical analysis with angle resolved X-ray photoelectron spectroscopy revealed that ageing induces a net enrichment in chromium oxide in the inner part of the passive film and an increase of the thickness of the inner oxide. Semiconducting behavior of the passive films was revealed by a Mott-Schottky analysis. The passive film was considered as a dielectric with different trapping levels lying in the bandgap. The observed n- or p-type…

Efficient vacuum deposited p-i-n and n-i-p perovskite solar cells employing doped charge transport layers

2016

Methylammonium lead halide perovskites have emerged as high performance photovoltaic materials. Most of these solar cells are prepared via solution-processing and record efficiencies (>20%) have been obtained employing perovskites with mixed halides and organic cations on (mesoscopic) metal oxides. Here, we demonstrate fully vacuum deposited planar perovskite solar cells by depositing methylammonium lead iodide in between intrinsic and doped organic charge transport molecules. Two configurations, one inverted with respect to the other, p-i-n and n-i-p, are prepared and optimized leading to planar solar cells without hysteresis and very high efficiencies, 16.5% and 20%, respectively. It is t…

The Relationship of Sexism and Gender Ideology to Self-Concept and Self-Esteem in Persons with Spinal Cord Injury

2017

The process of adapting to a physical disability is complex and multi-dimensional. It is influenced by many variables that affect adequate life adjustment and psychological wellbeing. This study addresses the specific effects of sexism and gender stereotypes on self-esteem and selfconcept in persons with spinal cord injury (SCI). The research design is cross-sectional and correlational. The sample comprises 127 persons, including 95 men and 32 women, with a long-term spinal injury. The results of the MANOVAs do not demonstrate statistically significant differences based on sex for the following variables: self-esteem, self-concept, traditional sexism and neosexism. The relationships among v…