Blue organic seven segment display based on poly (9,9-dioctyfluorene)with β-phase emission

In this work, organic seven segment displays based on poly(9,9-dioctyfluorene), PFO, have been fabricated. PFO has consolidated as an attractive material for PLEDs due to its efficient blue emission [1] and high hole mobility. Additionally, PFO has a particular conformation, called β-phase associated to extended PFO chain conformation, which is of great interest for potential device applications because, among all others, it has the highest photoluminescence quantum efficiency [2] and the best colour stability [3]. The structure fabricated uses Indium Tin Oxide (ITO) as anode, Poly(3,4 -ethylenedioxythiophene) /poly(4- styrenesulfonate) (PEDOT:PSS) as hole transport layer and Ba:Al as cathode. After thoroughly cleaning the substrates (covered with ITO) a photolithography process is carried out in order to pattern the anode. Next, the organic layers (PEDOTT:PSS and PFO) are spin casted. Finally, metals (Ba~30 nm and Al~100 nm) are thermally evaporated in an atmosphere of 6x10 -6 Torr. PFO is dissolved in toluene at 1 % wt. A detailed description of the fabrication process can be found in [4]. Finally, the device is encapsulated (using an epoxy and a glass tap) and contacts are indium soldered on the pads. In figure 1, we can observe the shadow mask used for the anode photolitography process (left) and the final device lighting in a zero configuration (right)

Weierstrass’ theorem with weights

25 pages, no figures.-- MSC2000 codes: 41A10, 41A28, 41A30.MR#: MR2053535 (2005g:41082)Zbl#: Zbl 1045.41005We characterize the set of functions which can be approximated by continuous functions in the L∞ norm with respect to almost every weight. This allows to characterize the set of functions which can be approximated by polynomials or by smooth functions for a wide range of weights.Research by first, third and fourth authors partially supported by a grant from DGI (BFM 2000-0022), Spain. Research by third author also partially supported by a grant from DGI (BFM 2000-0206-C04-01), Spain.Publicad

Weighted Weierstrass' theorem with first derivatives

32 pages, no figures.-- MSC2000 codes: 41A10, 46E35, 46G10.MR#: MR2338656 (2008g:41004)Zbl#: Zbl pre05173014We characterize the set of functions which can be approximated by continuous functions with the norm $\ \ {L infty(w)}$ for every weight w. This fact allows to determine the closure of the space of polynomials in $L infty(w)$ for every weight w with compact support. We characterize as well the set of functions which can be approximated by smooth functions with the norm \ \ {W 1,\infty}(w_0,w_1)}\coloneq \ \ {L infty(w_0)}+ \ '\ {L infty(w_1)}, for a wide range of (even non-bounded) weights $w_0,w_1$. We allow a great deal of independence among the weights.Research by first (A.P.), third (J.M.R.) and fourth (E.T.) autors was partially supported by three grants from MEC (MTM 2006-11976, MTM 2006-13000-C03-02, MTM 2006-26627-E), Spain.Publicad

Weierstrass' theorem in weighted Sobolev spaces with k derivatives

36 pages, no figures.-- MSC2000 codes: 41A10, 46E35, 46G10.MR#: MR2382639 (2008m:41022)Zbl#: Zbl 1177.41007We characterize the set of functions which can be approximated by smooth functions and by polynomials with the norm $$\ \ ^{(j)}\ {W^{k,\infty}_w}=\sum_ {j=0}^k\ {L^{\infty}_{w_j}},$$ for a wide range of (possibly unbounded) vector weights $w=(w_0,\dots, w_k)$. We allow a great deal of independence among the weights $w=(w_0,\dots, w_k)$.Research of the first, thord and fourth authors partially supported by grants from DGI (MTM 2006-13000-C03-02, MTM 2003-11976 and MTM 2006-26627-E), Spain.Publicad

Concerning asymptotic behavior for extremal polynomials associated to nondiagonal sobolev norms

Let ℙ be the space of polynomials with complex coefficients endowed with a nondiagonal Sobolev norm || · ||W 1, p (Vμ), where the matrix V and the measure μ constitute a p -admissible pair for 1 ≤ p ≤ ∞. In this paper we establish the zero location and asymptotic behavior of extremal polynomials associated to || · ||W 1, p (Vμ), stating hypothesis on the matrix V rather than on the diagonal matrix appearing in its unitary factorizationAna Portilla and Eva Tourís are supported in part by a grant from Ministerio de Ciencia e Innovación (MTM 2009-12740-C03-01), Spain. Yamilet Quintana is supported in part by the Research Sabbatical Fellowship Program (2011-2012) from Universidad Simón Bolvar, Venezuela. Ana Portilla, José M. Rodríguez, and Eva Tourís are supported in part by two grants from Ministerio de Ciencia e Innovación (MTM2009-07800 and MTM2008-02829-E), Spain. José M. Rodríguez is supported in part by a grant from CONACYT (CONACYT-UAGI0110/62/10 FON.INST.8/10), Méxic

Evaluation of radiography as a screening method for detection and characterisation of congenital vertebral malformations in dogs

Congenital vertebral malformations (CVM) are common in brachycephalic ‘screw-tailed’ dogs; they can be associated with neurological deficits and a genetic predisposition has been suggested. The purpose of this study was to evaluate radiography as a screening method for congenital thoracic vertebral malformations in brachycephalic ‘screw-tailed’ dogs by comparing it with CT. Forty-nine dogs that had both radiographic and CT evaluations of the thoracic vertebral column were included. Three observers retrospectively reviewed the images independently to detect CVMs. When identified, they were classified according to a previously published radiographic classification scheme. A CT consensus was then reached. All observers identified significantly more affected vertebrae when evaluating orthogonal radiographic views compared with lateral views alone; and more affected vertebrae with the CT consensus compared with orthogonal radiographic views. Given the high number of CVMs per dog, the number of dogs classified as being CVM free was not significantly different between CT and radiography. Significantly more midline closure defects were also identified with CT compared with radiography. Malformations classified as symmetrical or ventral hypoplasias on radiography were frequently classified as ventral and medial aplasias on CT images. Our results support that CT is better than radiography for the classification of CVMs and this will be important when further evidence of which are the most clinically relevant CVMs is identified. These findings are of particular importance for designing screening schemes of CVMs that could help selective breeding programmes based on phenotype and future studies

Exactitud en la Identificación de Caras y Tiempo de Respuesta: Face Identification Accuracy and Response Latency

El objetivo de este trabajo consistió en analizar en dos experimentos la relación existente entre la exactitud de la identificación de personas y el tiempo de respuesta. Para ello se presentó brevemente la fotografía de una persona desconocida. A continuación los sujetos realizaron una tarea distractora. Después trataron de reconocer a la persona objetivo, en una fotografía nueva, entre un conjunto de seis fotografías de personas de apariencia similar. Los resultados muestran que existe una amplia variabilidad en el tiempo de respuesta para las identificaciones correctas y las falsas alarmas. Sólo en el experimento 2, en el que se pidió a los sujetos que trataran de identificar a la persona objetivo en una tarea de elección forzosa, se encontraron diferencias significativas en el tiempo de respuesta en función del acierto. Los sujetos que acertaron tardaron menos tiempo en contestar que los sujetos que señalaron erróneamente a uno de los cebos de la rueda. En general, el tiempo de respuesta fue superior a los 10-12 segundos propuestos por Dunning y Perretta (2002) como tiempo límite para predecir las identificaciones correctas. Los resultados se analizan considerando sus posibles implicaciones en la valoración de la exactitud de los testigos en las pruebas de reconocimiento de sospechosos.[ABSTRACT] The aim of this project was to examine the relationship between the accuracy in the identification of persons and the response time, by means of two experiments. In the experiment 1 the subjects were presented a photographic image of an unknown person and then they were asked to perform a distracting task. Subsequently they tried to identify the target person in a new photography placed among a set of five images of persons of a similar appearance. The results showed that there is a large variability in the response time between correct identifications and false alarms. In the experiment 2 the subjects were asked to identify the target person in a forced choice assignment. In this test significant differences in the response time were found in relation to the right answer. The subjects that gave correct responses took less time in answering than the subjects that gave false alarms by choosing one of the foils in the lineup. In most cases the response time was higher than the 10-12 sec proposed by Dunning and Perretta (2002) as the time limit needed to predict the correct identifications. The results will be examined considering the possible implications regarding the evaluation of the eyewitnesses’ exactitude in the suspects’ recognition assignments

Singular Temperatures Connected to Charge Transport Mechanism Transitions in Perylene Bisimides from Steady-State Photocurrent Measurements

Perylene bisimides (PBIs) are n-type semiconducting and photogenerating materials widely used in a variety of optoelectronic devices. Particularly interesting are PBIs that are simultaneously water-soluble and liquid-crystalline (PBI-W+LC) and, thus, attractive for the development of high-performing easily processable applications in biology and “green” organic electronics. In this work, singular temperatures connected to charge transport mechanism transitions in a PBI-W+LC derivative are determined with high accuracy by means of temperature-dependent photocurrent studies. These singular temperatures include not only the ones observed at 60 and 110 °C, corresponding to phase transition temperatures from crystalline to liquid-crystalline (LC) and from LC to the isotropic phase, respectively, as confirmed by differential scanning calorimetry (DSC), but also a transition at 45 °C, not observed by DSC. By analyzing the photocurrent dependence simultaneously on temperature and on light intensity, this transition is interpreted as a change from monomolecular to bimolecular recombination. These results might be useful for other semiconducting photogenerating materials, not necessarily PBIs or even organic semiconductors, which also show transport behavior changes at singular temperatures not connected with structural or phase transitions.We appreciate support from the Spanish government (MINECO) and the European Community (FEDER) through Grant MAT-2011-28167-C02-01, as well as the University of Alicante. We gratefully acknowledge financial support from MINECO (MAT2014-52305-P) and the UCM-BSCH joint project (GR3/14-910759). A. de la Peña thanks Universidad Complutense for a predoctoral fellowship

Distributed feedback lasers based on dichromated poly(vinyl alcohol) reusable surface-relief gratings

A simple, low-cost and versatile holographic method to produce reusable surface-relief gratings on dichromated poly(vinyl alcohol) (DCPVA) films, with periods Λ ≥ 270 nm and modulation depths up to 300 nm, is reported. DCPVA presents processing advantages with respect to other photoresists, such as dichromated gelatine, i.e. higher light sensitivity, simpler fabrication process and better batch to batch reproducibility. The successful use of these DCPVA relief gratings as distributed feedback (DFB) laser resonators is demonstrated. Second-order DFB devices emitting in the wavelength range 577-614 nm have been easily prepared by coating a dye-doped polymer film on top of the resonators.We thank the Spanish Government (MINECO) and the European Union (FEDER) for grant no. MAT2011-28167-C02