V-substituted In2S3: an intermediate band material with photocatalytic activity in the whole visible light range

We proposed in our previous work V-substituted In2S3 as an intermediate band (IB) material able to enhance the efficiency of photovoltaic cells by combining two photons to achieve a higher energy electron excitation, much like natural photosynthesis. Here this hyper-doped material is tested in a photocatalytic reaction using wavelength-controlled light. The results evidence its ability to use photons with wavelengths of up to 750 nm, i.e. with energy significantly lower than the bandgap (=2.0 eV) of non-substituted In2S3, driving with them the photocatalytic reaction at rates comparable to those of non-substituted In2S3 in its photoactivity range (λ ≤ 650 nm). Photoluminescence spectra evidence that the same bandgap excitation as in V-free In2S3 occurs in V-substituted In2S3 upon illumination with photons in the same sub-bandgap energy range which is effective in photocatalysis, and its linear dependence on light intensity proves that this is not due to a nonlinear optical property. This evidences for the first time that a two-photon process can be active in photocatalysis in a single-phase material. Quantum calculations using GW-type many-body perturbation theory suggest that the new band introduced in the In2S3 gap by V insertion is located closer to the conduction band than to the valence band, so that hot carriers produced by the two-photon process would be of electron type; they also show that the absorption coefficients of both transitions involving the IB are of significant and similar magnitude. The results imply that V-substituted In2S3, besides being photocatalytically active in the whole visible light range (a property which could be used for the production of solar fuels), could make possible photovoltaic cells of improved efficiency.

Reflectancia multiespectral (visible e inferarrojo cercano) y composición de las cromitas. Datos preliminares

Se aborda por primera vez la relación entre el espectro VNIR de reflectancia especular y los parámetros composicionales del grupo de las espinelas, particularmente cromita

Optoelectronic property analysis of MCrO4 (M=Ba, Sr) with a response to visible light irradiation

Ternary MCrO4 (M = Ba, Sr) semiconductors are materials with a variety of photocatalyst and optoelectronic applications. We present detailed microscopic analyses based on first principles of the structure, the electronic properties and the optical absorption in which the difference between symmetrically non-equivalent atoms has been considered. The high absorption coefficients of these materials are split into chemical species contributions in accordance with the symmetry. The high optical absorption in these materials is mainly because of the Cr–O inter-species transitions.

A diversidade cultural e as suas implicações no processo de ensino e aprendizagem : como integrar a diversidade na educação de infância

Relatório de estágio apresentado para obtenção do grau de mestre na especialidade profissional de Educação pré-escolar

Optical images of visible and invisible percepts in the primary visual cortex of primates

We optically imaged a visual masking illusion in primary visual cortex (area V-1) of rhesus monkeys to ask whether activity in the early visual system more closely reflects the physical stimulus or the generated percept. Visual illusions can be a powerful way to address this question because they have the benefit of dissociating the stimulus from perception. We used an illusion in which a flickering target (a bar oriented in visual space) is rendered invisible by two counter-phase flickering bars, called masks, which flank and abut the target. The target and masks, when shown separately, each generated correlated activity on the surface of the cortex. During the illusory condition, however, optical signals generated in the cortex by the target disappeared although the image of the masks persisted. The optical image thus was correlated with perception but not with the physical stimulus.

Chronic morphine induces visible changes in the morphology of mesolimbic dopamine neurons.

The mesolimbic dopamine system, which arises in the ventral tegmental area (VTA), is an important neural substrate for opiate reinforcement and addiction. Chronic exposure to opiates is known to produce biochemical adaptations in this brain region. We now show that these adaptations are associated with structural changes in VTA dopamine neurons. Individual VTA neurons in paraformaldehyde-fixed brain sections from control or morphine-treated rats were injected with the fluorescent dye Lucifer yellow. The identity of the injected cells as dopaminergic or nondopaminergic was determined by immunohistochemical labeling of the sections for tyrosine hydroxylase. Chronic morphine treatment resulted in a mean approximately 25% reduction in the area and perimeter of VTA dopamine neurons. This reduction in cell size was prevented by concomitant treatment of rats with naltrexone, an opioid receptor antagonist, as well as by intra-VTA infusion of brain-derived neurotrophic factor. In contrast, chronic morphine treatment did not alter the size of nondopaminergic neurons in the VTA, nor did it affect the total number of dopaminergic neurons in this brain region. The results of these studies provide direct evidence for structural alterations in VTA dopamine neurons as a consequence of chronic opiate exposure, which could contribute to changes in mesolimbic dopamine function associated with addiction.

Electrically Tunable Selective Reflection of Light from Ultraviolet to Visible and Infrared by Heliconical Cholesterics

Acknowledgements This work was supported by NSF DMR-1410378 and DMR-1121288. We thank V. Borshch for helping with preparation of illustrations, to Y. K. Kim for the help in experiments, V. A. Belyakov and S. V. Shiyanovskii for useful discussions.

Reducing Stigma toward Sexual Minorities: Acceptance-Based versus Traditional Safe Zone Training.

Homophobia continues to exist in society. Homonegative attitudes are often implicit and can be acquired without direct training, which makes them particularly resistant to change. Relational Frame Theory (RFT) is a behavior analytic account of learning processes and can explain these processes of indirect learning. RFT also suggests therapeutic processes for dismantling stigma using a therapy model named Acceptance and Commitment Therapy (ACT). This paper reviews previous research on traditional multicultural training, and addresses its shortcomings. Specifically, this paper makes the argument that traditional models encourage experiential avoidance and thus further perpetuate the processes that maintain stigma. While a handful of studies have examined stigma interventions using ACT, no ACT studies have been completed specifically on the stigma towards gay and lesbian individuals. This paper concludes with a research proposal for such a study.

El desarrollo del pensamiento visible en la enseñanza de la Historia en alumnos de Magisterio

Se trata de una propuesta didáctica basada en el diseño de nuevas estrategias de enseñanza y aprendizaje, consistente en la elaboración de una programación de la asignatura de Didáctica de las Ciencias Sociales: Historia, en la que la teoría y la práctica están totalmente integradas de manera que la realización de la práctica suponga un avance más eficaz en el conocimiento y aprendizaje teórico. Para ello se ha utilizado una metodología activa, fundamentada en el desarrollo del pensamiento visible, en dónde el alumno es el sujeto sobre el que descansa toda la responsabilidad de su propio aprendizaje, pero siempre bajo la supervisión y colaboración del docente. También se ha incluido una batería de cuestiones sobre la docencia en la enseñanza de la Historia que inducen a la reflexión y al debate. De igual manera se ha modificado el modelo de evaluación, de forma que ésta sea formativa, no sumativa, y en la que el alumnado demuestra no solo su conocimiento, sino su saber hacer utilizando una gran variedad de instrumentos que le facilitan su planteamiento didáctico como futuro docente y su capacidad para ser consciente de su propio pensamiento, haciéndolo más visible para él mismo y para los demás.

Relative Concerns on Visible Consumption: A Source of Economic Distortions

Do relative concerns on visible consumption give rise to economic distortions? We re-examine the question posited by Arrow and Dasgupta (2009) building upon their general framework but recognizing that relative concerns can only apply to visible goods (e.g., cars, clothing, jewelry) and that households consume both visible and non-visible goods. Contrary to Arrow and Dasgupta (2009), the answer to this question turns to be always affirmative: the competitive equilibrium will always be different than the socially optimal one, since individuals do not take into account the negative externality they exert on others through the consumption of the visible good, while the social planner does. If one invokes separability assumptions, then the steady state competitive equilibrium consumption of non-visible goods will be strictly lower than the socially optimal one.

La protezione delle minoranze in Italia e il mancato riconoscimento della minoranza rom: ragioni e conseguenze = "The protection of minorities in Italy and the non-recognition of the Roma minority: reasons and consequences." EDAP 03/2013

No abstract.

National Minorities, Nationalizing States, and External National Homelands in the New Europe. Notes toward a Relational Analysis. Institute of Advanced Studies Political Science Series, 11 December 1993

Nationalism remains central to politics in and among the new nation-states. Far from »solving« the region's national question, the most recent reconfiguration of political space – the replacement of the Soviet Union, Yugoslavia, and Czechoslovakia by some twenty would-be nation-states – only recast it in a new form. It is this new phase and form of the national question that I explore in this paper. I begin by outlining a particular relational configuration – the triadic relational nexus between national minorities, nationalizing states, and external national homelands – that is central to the national question in post-Soviet Eurasia. In the second, and most substantial, section of the paper, I argue that each of the »elements« in this relational nexus – minority, nationalizing state, and homeland – should itself be understood in dynamic and relational terms, not as a fixed, given, or analytically irreducible entity but as a field of differentiated positions and an arena of struggles among competing »stances.« In a brief concluding section, I return to the relational nexus as a whole, underscoring the dynamically interactive quality of the triadic interplay.

Die Europäische Union und das Rahmenübereinkommen zum Schutz nationaler Minderheiten: ignorieren, parallell “umsetzen“ oder gar beitreten? = The European Union and the Framework Convention for the Protection of National Minorities: ignore, "implement" or even join? EDAP Paper 04/2014

This paper looks at the Council of Europe Framework Convention for the Protection of National Minorities (FCNM) through the lense of European Union law. It does so by posing four major questions: does the fact that 24 of 28 Member States of the EU ratified the FCNM have any legal implications for the European Union itself? Secondly, turning to the national level, does it make a difference for the implementation of the FCNM whether or not a state that has ratified the FCNM is also a member to the European Union? Thirdly, returning to the European Union itself, can and should the EU accede to the FCNM? Or are there, finally, any means beside ratification that would allow the European Union to implement the objectives and obligations as enshrined in the FCNM? These four questions are analysed in detail before the paper concludes on the potential role of the European Union in managing diversity and protecting (persons belonging to) minorities.