Search results for "CIRCUIT"

Polymer solar cells based on diphenylmethanofullerenes with reduced sidechain length

2011

Diphenylmethanofullerenes (DPMs) show interesting properties as acceptors in polymer bulk heterojunction solar cells due to the high open circuit voltages they generate compared to their energy levels. Here we investigate the effect of reducing the alkane sidechain length of the DPMs from C12 to C6 in the properties of the solar cell. This change leads to an increase in the electron mobility, thus allowing for a lower fullerene content, which in turn results in an increase in the short circuit current and, finally, in an increase in the efficiency of the device (from 2.3 to 2.6%) due to the higher concentration of the more absorbing polymer in the film. Atomic force microscopy images and ex…

Influence of the cyanine counter anions on a bi-layer solar cell performance

2013

ABSTRACTWe present normal and inverted solution processed bi-layer solar cells using cationic cyanine dyes as the electron donor and a fullerene as the electron acceptor. The cells exhibit high open circuit voltages up to 1 volt showing the optimal alignment of donor and acceptor energy levels. We demonstrate the large effect that cyanine dye counter ions can have on the energetics of the solar cells and how the S-shaped current density vs. voltage (J-V) curves can be avoided.

Photoelectrical properties of indandione fragment containing azobenzene compounds

2014

Organic materials are becoming more popular due to their potential application in electronics. Low molecular weight materials possible produce from solution are in special consideration. It gives the possibility to avoid both thermal evaporation in vacuum, and use of polymers in thin film preparation process. Indandione fragment containing azobenzene compounds are one of such materials. These compounds are good candidates for use in design of novel molecular electronic devices due to their possibility to form amorphous structure from solution thus allowing developing flexible, small size systems with low production costs. In this work three indandione fragment containing azobenzene compound…

Photovoltaic effect in bulk heterojunction system with glass forming indandione derivative DMABI-6Ph

2018

The aim of the work is to evaluate possible use of 2-[[4-(bis(2-trityloxyethyl)amino)phenyl]methylene]indane-1,3-dione (DMABI-6Ph) as light absorbing material for solar cells. DMABI-6Ph is a perspective material due to its good photoelectrical, thermal and chemical properties. The main advantage of DMABI-6Ph is its ability to form amorphous films by wet-casting methods thus allowing using the compound in organic solar cells made from solution. For now most popular materials for solution processable solar cells are polymer P3HT and fullerene derivative PCBM, but lot of investigations are in the field of new low molecular weight materials to replace the polymer. Photoelectrical measurements w…

Critical-state effects on microwave losses in type-II superconductors

2006

We discuss the microwave energy losses in superconductors in the critical state. The field-induced variations of the surface resistance are determined, in the framework of the Coffey and Clem model, by taking into account the distribution of the vortex magnetic field inside the sample. It is shown that the effects of the critical state cannot generally be disregarded to account for the experimental data. Results obtained in bulk niobium at low temperatures are quantitatively justified.

Estudio de la conectividad de los circuitos neuronales del bulbo olfatorio de los primates. Comparación de individuos control con casos de Parkinson

2015

La enfermedad de Parkinson es una enfermedad neurodegenerativa multisistémica que afecta al sistema nervioso central y periférico. Caracterizada por la degeneración selectiva de la neuronas dopaminérgicas de la sustancia negra pars compacta (SNpc), se englobada dentro de las llamadas α-sinucleinopatías. El sello distintivo de esta patología es la propagación de agregados proteicos patológicos de α-sinucleína, en forma de cuerpos y neuritas de Lewy, a lo largo de todo el sistema nervioso. La sintomatología con la que cursa esta enfermedad puede clasificarse en dos grandes categorías: síntomas no motores o pre-clínicos y síntomas motores o clínicos. Cronológicamente, los primeros anteceden a …

Influencia de la estimulación eléctrica del Núcleo Incertus sobre la actividad del circuito hipocampo-amígdala- prefrontal

2023

El núcleo incertus (NI), sensible al estrés y parte del sistema reticular activador ascendente, proyecta a las principales estructuras implicadas en la generación y modulación del ritmo theta hipocámpico, por lo que ha sido relacionado con la respuesta al estrés y procesos cognitivos. El hipocampo, implicado en el aprendizaje y la memoria, presenta un gradiente dorsoventral conectivo y funcional. La región dorsal participa en la navegación espacial y las porciones ventral e intermedia se han asociado con respuestas emocionales y con el valor motivacional. Estudios previos han demostrado el papel regulador del NI sobre la actividad theta de hipocampo dorsal, pero se desconoce su papel sobre …

Bases physiologiques de la satiété et de la digestion

2015

The pedagogy of multiliteracies as a code breaker : A suggestion for a transversal approach to computing education in basic education

2021

While computing has been (re)introduced into the basic education curricula in various countries, its actual implementation appears to be inconsistent. There are schools in which computing education is commonplace, while the implementation seems to be lagging behind in others. There is emerging evidence that some teachers do not consider computing education relevant, meaningful and important and, thus, intentionally neglect its provision. This is problematic as understanding the principles of code and computing is crucial for agentic citizenship in the post-digital era. This paper argues that one main reason for these teachers' reluctance is the economy-driven discursive framing of computing…

Computing temporal sequences associated with dynamic patterns on the C. elegans connectome

2021

AbstractUnderstanding how the structural connectivity of a network constrains the dynamics it is able to support is a very active and open area of research. We simulated the plausible dynamics resulting from the known C. elegans connectome using a recent model and theoretical analysis that computes the dynamics of neurobiological networks by focusing on how local interactions among connected neurons give rise to the global dynamics in an emergent way, independent of the biophysical or molecular details of the cells themselves. We studied the dynamics which resulted from stimulating a chemosensory neuron (ASEL) in a known feeding circuit, both in isolation and embedded in the full connectome…