Search results for "LED"

Towards a General Definition of Modeling

2010

What is a model? Surprisingly, in philosophical texts, this question is asked (sometimes), but almost never – answered. Instead of a general answer, usually, some classification of models is considered. The broadest possible definition of modeling could sound as follows: a model is anything that is (or could be) used, for some purpose, in place of something else. If the purpose is “answering questions”, then one has a cognitive model. Could such a broad definition be useful? Isn't it empty? Can one derive useful consequences from it? I'm trying to show that there is a lot of them.

Grazia Deledda e i moderni circoli letterari cinesi: traduzioni e studi critici nella stampa periodica degli anni Venti e Trenta

2017

Grazia Deledda's literary work has been introduced by the early 20th century Chinese translators mostly through indirect translations. Such process compromised sometimes the integrity of the original linguistic choices, but the selection of contributions from the Chinese periodical press included in this study shows a genuine enthusiasm toward her narrative style and the life of Deledda's Sardinian characters, portrayed as symbolic representation of the universal human psychology.

Simple Rules for Complex Near-Glass-Transition Phenomena in Medium-Sized Schiff Bases

2022

Glass-forming ability is one of the most desired properties of organic compounds dedicated to optoelectronic applications. Therefore, finding general structure–property relationships and other rules governing vitrification and related near-glass-transition phenomena is a burning issue for numerous compound families, such as Schiff bases. Hence, we employ differential scanning calorimetry, broadband dielectric spectroscopy, X-ray diffraction and quantum density functional theory calculations to investigate near-glass-transition phenomena, as well as ambient- and high-pressure molecular dynamics for two structurally related Schiff bases belonging to the family of glycine imino esters. Firstly…

Enhancing Light Emission in Interface Engineered Spin-OLEDs through Spin-Polarized Injection at High Voltages

2019

The quest for a spin-polarized organic light-emitting diode (spin-OLED) is a common goal in the emerging fields of molecular electronics and spintronics. In this device, two ferromagnetic (FM) electrodes are used to enhance the electroluminescence intensity of the OLED through a magnetic control of the spin polarization of the injected carriers. The major difficulty is that the driving voltage of an OLED device exceeds a few volts, while spin injection in organic materials is only efficient at low voltages. The fabrication of a spin-OLED that uses a conjugated polymer as bipolar spin collector layer and ferromagnetic electrodes is reported here. Through a careful engineering of the organic/…

Molecular Spintronic Devices: from Molecular Spin Valves to Spin-OLEDs

2017

La investigación llevada a cabo durante el periodo de tesis doctoral y que se describe en este manuscrito pertenece al campo de la espintrónica molecular. Ha sido motivada por el deseo de incorporar nuevos materiales moleculares a dispositivos espintrónicos y ahondar en la comprensión de la inyección y el transporte de espín en este tipo de capas, a través del estudio de dispositivos como la válvula de espín molecular y el spin-OLED. En 1988 Albert Fert y Peter Grünberg descubrieron que la resistencia eléctrica de unas multicapas de Fe-Cr variaba considerablemente en función de la magnetización de las láminas. El efecto se conoce hoy en día como magnetoresistencia gigante o GMR, por sus sig…

Molecular nanostructures on ferromagnetic metals for spintronics

2017

El objetivo principal de esta tesis ha sido el estudio de la funcionalización de superficies ferromagnéticas mediante la formación de monocapas moleculares autoensambladas, (SAMs, self-assembled monolayers) con el fin de conseguir procesos sencillos y fiables para la preparación de interfaces híbridas aplicables en dispositivos de espintrónica molecular. La investigación se ha centrado en la funcionalización de materiales ferromagnéticos, concretamente el cobalto y la aleación de níquel:hierro conocida como Permalloy. Las propiedades magnéticas y de polarización de espín de estos metales ferromagnéticos se mantienen a temperatura ambiente, lo que los hace muy interesantes para su aplicación…

Schede per il censimento degli alberi monumentali di Sicilia. 27-36

2010

Conceptualizing nature-based science tourism: a case study of Seili Island, Finland

2021

Nature-based tourism has been widely addressed, yet research on nature-based science tourism, founded on science, scientific knowledge, and/or engagement in scientific research, is still scarce. Drawing on tourist motivation, nature-based tourism, special interest tourism, and science tourism, a novel theoretical conceptualization of nature-based science tourism was developed. The framework identified three categories of science tourism with intensifying levels of tourists’ interest in scientific knowledge and tourist engagement: tourism based on scientific knowledge, tourism with scientific adventure or volunteering, and scientific research tourism. In the empirical part, the framework was…

Affect in the Context of Self-Determination Theory

2018

Self-determination theory has been applied to understand the role of affect in motivation and behavior in health contexts. According to self-determination theory, autonomous forms of motivation, reflecting self-endorsed reasons for acting and the satisfaction of psychological needs, are related to participation and persistence in health behavior. Research examining the role of affect in determining health behavior from the perspective of the theory is relatively sparse. Affect has served as both an outcome and process in applications of the theory to health behavior. Positive affect and psychological well-being have been identified as important outcomes of participating in behaviors for aut…

Readers’ Theater Projects for Special Education : A Randomized Controlled Study

2022

A randomized controlled trial was conducted to study the effectiveness of two readers’ theater (RT) programs in promoting reading skills and motivation of dysfluent readers in Grades 3–4. One program (RT Goal) included a goal of preparing a performance for an audience (n = 50), while another program (RT Practice) did not include such a goal (n = 49). A group of dysfluent readers receiving traditional oral reading intervention (Control group; n = 59) and a group of classroom peers (Mainstream group; n = 159) served as controls. The results indicate that both RT groups and the Control group developed at a higher rate in oral reading speed during the intervention period than the Mainstream gro…