28 research outputs found

    Electro-optical Simulation of a-Si Thin-Film-Transistor Liquid Crystal Display Pixels

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    An analysis of an amorphous silicon (a-Si) thin-film-transistor liquid-crystal display (TFT-LCD) pixel is presented. The electro-optical model combines the electrical properties of the switching element and the optical performance of a twisted nematic (TN) liquid-crystal cell.Publicad

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

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    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)

    Electro-optic system for online light transmission control of polymer-dispersed liquid crystal windows

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    Polymer-dispersed liquid crystals (PDLCs) are formed by micro droplets of liquid crystal embedded in a flexible matrix and sandwiched between transparent electrodes. Large area units (several square meters) can be easily prepared. Opaque, transparent, and intermediate light transmission states can be achieved by applying appropriate electric fields These features allow their use in active windows for illumination, greenhouse regulation, and privacy, both on buildings and vehicles. An electro-optic system based on a micro controlled driver was implemented for on-line control of PDLC windows. The system may self regulate daylight or may be used as remote control.Publicad

    XTEND: Extending the depth of field in cryo soft X-ray tomography

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    We have developed a new data collection method and processing framework in full field cryo soft X-ray tomography to computationally extend the depth of field (DOF) of a Fresnel zone plate lens. Structural features of 3D-reconstructed eukaryotic cells that are affected by DOF artifacts in standard reconstruction are now recovered. This approach, based on focal series projections, is easily applicable with closed expressions to select specific data acquisition parameters.This work was partially supported by MINECO grants BFU2014-54181 to JLC and AIC-A-2011-0638, BIO2013-44647-R and BIO2016-76400-R to JMC, Madrid. Regional government grants S2013/MIT-2850 to JLC and S2010/BMD-2305 to JMC, National Science Foundation grant DMS-1114901 to GTH, the European Union through BioStruct-X Project 283570 and Horizon 2020 through grant iNEXT (INFRAIA-1-2014-2015, Proposal: 653706).S

    Pure Membranous Lupus Nephritis: Description of a Cohort of 150 Patients and Review of the Literature

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    Objectives The course and long-term outcome of pure membranous lupus nephritis (MLN) are little understood. The aims of this study are to evaluate the clinical features, course, outcome and prognostic indicators in pure MLN and to determine the impact of ethnicity and the type of health insurance on the course and prognosis of pure MLN. Methods We conducted a retrospective review of medical records of 150 patients with pure MLN from Spain and the USA. Results Mean age was 34.2±12.5 and 80% were women. Sixty-eight percent of patients had nephrotic syndrome at diagnosis. The average serum creatinine was 0.98±0.78mg/dl. Six percent of patients died and 5.3% developed end-stage renal disease (ESRD). ESRD was predicted by male sex, hypertension, dyslipidemia, high basal 24h-proteinuria, high basal serum creatinine and a low basal creatinine clearance. Age, cardiac insufficiency, peripheral artheriopathy, hemodialysis and not having received mycophenolate mofetil or antimalarials for MLN predicted death. Conclusions Pure MLN frequently presents with nephrotic syndrome, high proteinuria and normal serum creatinine. Its prognosis is favourable in maintaining renal function although proteinuria usually persists over time. Baseline cardiovascular disease and not having a health insurance are related with poor prognosis

    Electrical response of liquid crystal cells doped with multi-walled carbon nanotubes

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    The inclusion of nanoparticles modifies a number of fundamental properties of many materials. Doping of nanoparticles in self-organized materials such as liquid crystals may be of interest for the reciprocal interaction between the matrix and the nanoparticles. Elongated nanoparticles and nanotubes can be aligned and reoriented by the liquid crystal, inducing noticeable changes in their optical and electrical properties. In this work, cells of liquid crystal doped with high aspect ratio multi-walled carbon nanotubes have been prepared, and their characteristic impedance has been studied at different frequencies and excitation voltages. The results demonstrate alterations in the anisotropic conductivity of the samples with the applied electric field, which can be followed by monitoring the impedance evolution with the excitation voltage. Results are consistent with a possible electric contact between the coated substrates of the LC cell caused by the reorientation of the nanotubes. The reversibility of the doped system upon removal of the electric field is quite low
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