111 research outputs found
Evolutionary parameter extraction for an organic TFT compact model including contact effects
Please cite this article as:
A. Romero, J. Gonzålez, R. Picos, M. J. Deen, J. A. Jiménez-Tejada, Evolutionary parameter extraction for an organic TFT compact model including contact effects, Organic Electronics, (2018), 61, 242-253.
© 2018. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/
Digital Object Identifier:
10.1016/j.orgel.2018.05.062
Source: https://www.sciencedirect.com/science/article/pii/S1566119918302908Parameter extraction is a complex procedure when contact effects are present. In this work, a multi-objective evolutionary parameter extraction procedure is used to simultaneously determine the parameters of both a compact model for the current-voltage characteristics of organic thin-film transistors and a contact model. This procedure can be used to overcome shortcomings of previous parameter extraction procedures. The proposed evolutionary procedure can be used in those situations whereby the parameter set extracted by other procedures does not comply its physical meaning, or if a poor agreement between the experimental data and the analytical results exists. In the last case, the evolutionary procedure can be used as a problem optimization method. After the evolutionary parameter extraction procedure is applied to the transistor output characteristics, the obtained results show an excellent agreement with the experimental data.This work was supported by projects TIN2015-67020-P, MAT2016-76892-C3-3-R, TEC2014-56244-R, and Excellence Networks REFLEXIO and NANOVAR funded by the Spanish âMinisterio de EconomĂa y Competitividadâ and European Regional Development Funds (ERDF)
MĂ©todo de segmentaciĂłn de cultivos
Se describe un mĂ©todo de distribuciĂłn espacial continua de la calidad del fruto dentro de una parcela de cultivo o una finca comercial que permite la segmentaciĂłn de dicha finca en sectores de distinta calidad, por lo tanto las zonas con mayor precio de mercado pueden ser recolectadas independientemente; permitiendo al agricultor obtener un mapa de calidad completo de sus cultivos previo a la organizaciĂłn de la recolecciĂłn del fruto.Peer reviewedConsejo Superior de Investigaciones CientĂficasA1 Solicitud de patente con informe sobre el estado de la tĂ©cnic
Compact modeling of organic thin film transistors with solution processed octadecyl substituted tetrabenzotriazaporphyrin as an active layer
Using 70nm thick spin-coated film of newly synthesized octadecyl substituted copper tetrabenzotriazaporphyrin (10CuTBTAP) as an active layer on a highly doped silicon (110) gate electrode substrates, output characteristics and transfer characteristics of bottom-gate bottom-contact organic thin film transistors have been measured at room temperature. A compact model for thin film transistors has been employed as a part of circuit design tool to extract device parameters such as the charge carrier mobility Ό, the threshold voltage VT and the contact resistances. Parallel measurements and analysis were performed on similarly constructed devices with a copper phthalocyanine analogue (10CuPc). The results reveal that the 10CuPc layer is relatively more susceptible to trapping degradation near the gate region than a 10CuTBTAP layer, which is significant in order to achieve stability in these transistors. The application of the simple square law in the classical MOS model provides a quicker but approximate interpretation of the transistor performance without providing information on the gate voltage dependence of mobility and the effects of the contact regions. In this comparative study, the analysis of the contact regions is found to be very important for determining the difference in the performance of two transistors
Evolutionary computation for parameter extraction of organic thin film transistors using newly synthesized liquid crystalline nickel phthalocyanine
© 2019 by the authors.In this work, the topic of the detrimental contact effects in organic thin-film transistors (OTFTs) is revisited. In this case, contact effects are considered as a tool to enhance the characterization procedures of OTFTs, achieving more accurate values for the fundamental parameters of the transistor threshold voltage, carrier mobility and on-off current ratio. The contact region is also seen as a fundamental part of the device which is sensitive to physical, chemical and fabrication variables. A compact model for OTFTs, which includes the effects of the contacts, and a recent proposal of an associated evolutionary parameter extraction procedure are reviewed. Both the model and the procedure are used to assess the effect of the annealing temperature on a nickel-1,4,8,11,15,18,22,25-octakis(hexyl)phthalocyanine (NiPc6)-based OTFT. A review of the importance of phthalocyanines in organic electronics is also provided. The characterization of the contact region in NiPc6 OTFTs complements the results extracted from other physicalâchemical techniques such as differential scanning calorimetry or atomic force microscopy, in which the transition from crystal to columnar mesophase imposes a limit for the optimum performance of the annealed OTFTs
Nicotianamine Synthase 2 Is Required for Symbiotic Nitrogen Fixation in Medicago truncatula Nodules
Symbiotic nitrogen fixation carried out by the interaction between legumes and diazotrophic bacteria known as rhizobia requires relatively large levels of transition metals. These elements are cofactors of many key enzymes involved in this process. Metallic micronutrients are obtained from soil by the roots and directed to sink organs by the vasculature, in a process mediated by a number of metal transporters and small organic molecules that facilitate metal delivery in the plant fluids. Among the later, nicotianamine is one of the most important. Synthesized by nicotianamine synthases (NAS), this molecule forms metal complexes participating in intracellular metal homeostasis and long-distance metal trafficking. Here we characterized the NAS2 gene from model legume Medicago truncatula. MtNAS2 is located in the root vasculature and in all nodule tissues in the infection and fixation zones. Symbiotic nitrogen fixation requires of MtNAS2 function, as indicated by the loss of nitrogenase activity in the insertional mutant nas2-1, phenotype reverted by reintroduction of a wild-type copy of MtNAS2. This would result from the altered iron distribution in nas2-1 nodules shown with X-ray fluorescence. Moreover, iron speciation is also affected in these nodules. These data suggest a role of nicotianamine in iron delivery for symbiotic nitrogen fixation
Thermal remote sensing from Airborne Hyperspectral Scanner data in the framework of the SPARC and SEN2FLEX projects: an overview
The AHS (Airborne Hyperspectral Scanner) instrument has 80 spectral bands covering the visible and near infrared (VNIR), short wave infrared (SWIR), mid infrared (MIR) and thermal infrared (TIR) spectral range. The instrument is operated by Instituto Nacional de TĂ©cnica Aerospacial (INTA), and it has been involved in several field campaigns since 2004. <br><br> This paper presents an overview of the work performed with the AHS thermal imagery provided in the framework of the SPARC and SEN2FLEX campaigns, carried out respectively in 2004 and 2005 over an agricultural area in Spain. The data collected in both campaigns allowed for the first time the development and testing of algorithms for land surface temperature and emissivity retrieval as well as the estimation of evapotranspiration from AHS data. Errors were found to be around 1.5 K for land surface temperature and 1 mm/day for evapotranspiration
Incidence, clinical characteristics and management of inflammatory bowel disease in Spain: large-scale epidemiological study
(1) Aims: To assess the incidence of inflammatory bowel disease (IBD) in Spain, to describe the main epidemiological and clinical characteristics at diagnosis and the evolution of the disease, and to explore the use of drug treatments. (2) Methods: Prospective, population-based nationwide registry. Adult patients diagnosed with IBDâCrohnâs disease (CD), ulcerative colitis (UC) or IBD unclassified (IBD-U)âduring 2017 in Spain were included and were followed-up for 1 year. (3) Results: We identified 3611 incident cases of IBD diagnosed during 2017 in 108 hospitals covering over 22 million inhabitants. The overall incidence (cases/100, 000 person-years) was 16 for IBD, 7.5 for CD, 8 for UC, and 0.5 for IBD-U; 53% of patients were male and median age was 43 years (interquartile range = 31â56 years). During a median 12-month follow-up, 34% of patients were treated with systemic steroids, 25% with immunomodulators, 15% with biologics and 5.6% underwent surgery. The percentage of patients under these treatments was significantly higher in CD than UC and IBD-U. Use of systemic steroids and biologics was significantly higher in hospitals with high resources. In total, 28% of patients were hospitalized (35% CD and 22% UC patients, p < 0.01). (4) Conclusion: The incidence of IBD in Spain is rather high and similar to that reported in Northern Europe. IBD patients require substantial therapeutic resources, which are greater in CD and in hospitals with high resources, and much higher than previously reported. One third of patients are hospitalized in the first year after diagnosis and a relevant proportion undergo surgery. © 2021 by the authors. Licensee MDPI, Basel, Switzerland
EpidemiologĂa y caracterĂsticas del ictus isquĂ©mico en el adulto joven en AragĂłn
IntroducciĂłn
Alrededor de 15 millones de personas sufren un ictus cada año, de los que un 10-15% ocurre en menores de 50 años (ictus en el adulto joven). La prevalencia de los distintos factores de riesgo vascular y las estrategias sanitarias para el manejo del ictus varĂan a nivel mundial, siendo interesante conocer la epidemiologĂa y las caracterĂsticas especĂficas de cada regiĂłn.
El objetivo de este estudio fue determinar la prevalencia de los diferentes factores de riesgo vascular, la etiologĂa y las caracterĂsticas de los ictus isquĂ©micos en el adulto joven en la comunidad autĂłnoma de AragĂłn.
MĂ©todos
Estudio multicĂ©ntrico, de corte transversal, realizado por los Servicios de NeurologĂa de todos los hospitales del Servicio AragonĂ©s de Salud (SALUD). Se identificĂł a todos los pacientes entre 18 y 50 años que ingresaron en cualquiera de estos hospitales con el diagnĂłstico de ictus isquĂ©mico o AIT entre enero del 2005 y diciembre del 2015. Se recogieron variables demogrĂĄficas, factores de riesgo vascular y tipo de ictus isquĂ©mico entre otras.
Resultados
En el periodo de estudio, 786 pacientes entre 18 y 50 años ingresaron con el diagnĂłstico de ictus isquĂ©mico o AIT en algĂșn hospital del SALUD, con una tasa anual promedio de 12, 3 por 100.000 habitantes. La mediana de su edad fue de 45 años (RIQ: 40-48 años). El factor de riesgo vascular mĂĄs prevalente fue el tabaquismo, 404 (51, 4%). La mayorĂa fue de causa indeterminada (36, 2%), seguida por «otras causas» (26, 5%). La mediana de puntuaciĂłn en la escala NIHSS fue de 3, 5 (RIQ: 2, 07, 0). En total, 211 (26, 8%) de los ingresos fueron por AIT. De los pacientes que ingresaron con el diagnĂłstico de ictus isquĂ©mico, 59 (10, 3%) se fibrinolizaron.
Conclusiones
El ictus isquĂ©mico en el adulto joven no es infrecuente en AragĂłn y en un importante nĂșmero de casos es de etiologĂa indeterminada, por lo que es necesario implementar medidas que nos permitan mejorar su estudio, disminuir su incidencia y prevenir su recurrencia.
Introduction: Stroke affects around 15 million people per year, with 10%-15% occurring in individuals under 50 years old (stroke in young adults). The prevalence of different vascular risk factors and healthcare strategies for stroke management vary worldwide, making the epidemiology and specific characteristics of stroke in each region an important area of research. This study aimed to determine the prevalence of different vascular risk factors and the aetiology and characteristics of ischaemic stroke in young adults in the autonomous community of Aragon, Spain.
Methods: A cross-sectional, multi-centre study was conducted by the neurology departments of all hospitals in the Aragonese Health Service. We identified all patients aged between 18 and 50 years who were admitted to any of these hospitals with a diagnosis of ischaemic stroke or TIA between January 2005 and December 2015. Data were collected on demographic variables, vascular risk factors, and type of stroke, among other variables.
Results: During the study period, 786 patients between 18 and 50 years old were admitted with a diagnosis of ischaemic stroke or TIA to any hospital of Aragon, at a mean annual rate of 12.3 per 100 000 population. The median age was 45 years (IQR: 40-48 years). The most prevalent vascular risk factor was tobacco use, in 404 patients (51.4%). The majority of strokes were of undetermined cause (36.2%), followed by other causes (26.5%). The median NIHSS score was 3.5 (IQR: 2.0-7.0). In total, 211 patients (26.8%) presented TIA. Fifty-nine per cent of the patients admitted with a diagnosis of ischaemic stroke (10.3%) were treated with fibrinolysis.
Conclusions: Ischaemic stroke in young adults is not uncommon in Aragon, and is of undetermined aetiology in a considerable number of cases; it is therefore necessary to implement measures to improve study of the condition, to reduce its incidence, and to prevent its recurrence
How the Emotional Content of Discourse Affects Language Comprehension
Emotion effects on cognition have often been reported. However, only few studies investigated emotional effects on subsequent language processing, and in most cases these effects were induced by non-linguistic stimuli such as films, faces, or pictures. Here, we investigated how a paragraph of positive, negative, or neutral emotional valence affects the processing of a subsequent emotionally neutral sentence, which contained either semantic, syntactic, or no violation, respectively, by means of event-related brain potentials (ERPs). Behavioral data revealed strong effects of emotion; error rates and reaction times increased significantly in sentences preceded by a positive paragraph relative to negative and neutral ones. In ERPs, the N400 to semantic violations was not affected by emotion. In the syntactic experiment, however, clear emotion effects were observed on ERPs. The left anterior negativity (LAN) to syntactic violations, which was not visible in the neutral condition, was present in the negative and positive conditions. This is interpreted as reflecting modulatory effects of prior emotions on syntactic processing, which is discussed in the light of three alternative or complementary explanations based on emotion-induced cognitive styles, working memory, and arousal models. The present effects of emotion on the LAN are especially remarkable considering that syntactic processing has often been regarded as encapsulated and autonomous
Percepção dos estudantes universitårios acerca do acesso à educação superior: um estudo exploratório
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