1,987 research outputs found

    Selective growth of Cu2O and metallic Cu by atomic layer deposition on ZnO and their application in optoelectronics

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    In this work we present the results on the selective growth of Cu2O and metallic Cu by atomic layer deposition (ALD) on ZnO, Al-doped ZnO (AZO) and α-Al2O3 substrates. It was possible to tune the deposited material (Cu or Cu2O) by controlling the deposition temperature, and the substrate conductivity/density of donor defects. An area-selective atomic layer deposition (AS-ALD) process was demonstrated on a patterned bi-layer structure composed of low-conductive ZnO, and highly-conductive AZO regions. Furthermore, the AS-ALD allows the fabrication of Cu2O/ZnO/AZO/Cu-back-electrode microjunctions, as confirmed by conductive atomic force microscopy (C-AFM). The mechanism behind the temperature and spatial selectivities is discussed. In a second part of this thesis, Cu nanoparticles (NP) were deposited by ALD on ZnO thin films. The Cu NP exhibit a localized surface plasmon resonance, tunable from the visible to the near-infrared regions, as confirmed by spectroscopic ellipsometry. An enhanced visible photo-response was observed in the Cu NP/ZnO device thanks to the hot-electron generation at the surface of the plasmonic Cu NP and transfer into the conduction band of ZnO. Finally, semi-transparent Cu2O/ZnO heterojunctions were fabricated by ALD and reactive magnetron sputtering. The heterojunctions present a stable self-powered photo-response under 1 Sun illumination, fast response times and high transparency in the visible region, which is promising for all-oxide transparent electronics, photodetection and photovoltaics.In dieser Arbeit präsentieren wir die Ergebnisse zum selektiven Wachstum von Cu2O und metallischem Cu durch Atomlagenabscheidung (ALD) auf ZnO-, Al-dotierten ZnO- (AZO) und α-Al2O3-Substraten. Es war möglich, das abgeschiedene Material durch Steuern der Temperatur, der Leitfähigkeit und der Dichte von Donatordefekten des Substrats abzustimmen. Ein flächenselektiver Atomlagenabscheidungsprozess (AS-ALD) wurde auf einer Zweischichtstruktur aus schwach leitfähigen ZnO- und hochleitfähigen AZO-Bereichen gezeigt. Des weiteren ermöglicht AS-ALD die Herstellung von Cu2O/ZnO/AZO/Cu-Rückelektroden-Nano-Übergängen, was durch leitfähige Rasterkraftmikroskopie (C-AFM) bestätigt wurde. Der Mechanismus hinter den Temperatur- und Ortsselektivität wird diskutiert. In einem zweiten Teil der Arbeit wurden Cu-Nanopartikel (NP) durch ALD auf ZnO-Dünnschichten abgeschieden. Die Cu-NP weisen eine lokalisierte Oberflächenplasmonresonanz auf, die vom sichtbaren Bereich bis zum nahen Infrarotbereich eingestellt werden kann, was durch spektroskopische Ellipsometrie bestätigt wurde. Eine Verstärkung der Fotoantwort im sichtbaren Bereich durch die Erzeugung heißer Elektronen wurde in einem Cu-NP/ZnO Schaltelement beobachtet. Schließlich wurden semitransparente Cu2O/ZnO-Heteroübergänge durch ALD und reaktives Magnetron-Sputtern hergestellt. Die Heteroübergänge bieten eine stabile selbstangetriebene Fotoantwort unter Sonnen-Beleuchtung, schnelle Reaktionszeiten und hohe Transparenz im sichtbaren Bereich.Dans ce travail, après l’état de l’art et la présentation de méthodes de synthèse et d’analyse, nous présentons des résultats sur la croissance sélective de Cu2O et Cu métallique par dépôt par couche atomique (ALD) sur ZnO, ZnO dopé à l’Al (AZO) et α-Al2O3. Nous mettons en évidence la possibilité de déposer de façon sélective Cu métallique ou Cu2O, en contrôlant la température de dépôt et la conductivité ou la densité des défauts ponctuels au sein du substrat. Un procédé sélectif local de dépôt par couche atomique (AS-ALD) a été mis en évidence sur une bicouche à motifs composée de zones de ZnO de faible conductivité et de régions d’AZO de forte conductivité. De plus, l'AS-ALD permet la fabrication de nano-jonctions à base de Cu2O/ZnO /AZO/Cu, dont le comportement de jonction p-n a été confirmé par microscopie à force atomique à pointe conductrice (C-AFM). Les mécanismes liés à la croissance sélective locale sont également discutés. Dans la seconde partie de cette thèse, des nanoparticules de Cu (NP) ont été déposées par ALD sur des couches minces de ZnO. Les NP de Cu présentent une résonance plasmon de surface localisée caractérisée par ellipsométrie. La position de la bande de résonance plasmon est ajustable entre les régions visible et infrarouge du spectre électromagnétique en gérant la taille des particules et leur espacement par l’intermédiaire du temps de dépôt. Le système Cu NP/ZnO montre une photo-réponse dans le visible grâce à la génération d'électrons chauds à la surface des NP de Cu et l'injection dans la bande de conduction de ZnO. Finalement, des hétérojonctions Cu2O/ZnO semi-transparentes ont été fabriquées par ALD et pulvérisation cathodique. Les hétérojonctions présentent une photo-réponse autoalimentée sous éclairement, des temps de réponse rapides et une transparence élevée dans le visible, ce qui est prometteur pour des applications dans les domaines de l’électronique transparente, la photo-détection et le photovoltaïque

    Saberes, Culturas y Derechos Sexuales en Colombia

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    Este libro reúne artículos de gran pertinencia académica en el tema, ponencias y discusiones que realizaron distintos grupos de trabajo en el marco del seminario Hacia una Agenda sobre Sexualidad y Derechos Humanos en Colombia, realizado en Bogotá durante los días 18, 19 y 20 de marzo de 2004. Este texto acerca a un público más amplio el debate que vienen desarrollando en Colombia investigadores, militantes, responsables y ejecutores de políticas públicas en materia de sexualidad y de derechos sexuales y reproductivos. La divulgación de los trabajos presentados en este libro permitirá a los lectores identificar las líneas de debate que orientan la investigación, las políticas públicas, los programas de intervención social y el derecho en este ámbito. El texto presenta hallazgos en torno a estos temas, con el objetivo de construir un referente común sobre la sexualidad como una construcción sociocultural e histórica objeto de una regulación pública. Igualmente, pretende inscribir la sexualidad en el ámbito de la construcción de ciudadanía y de la reivindicación de los derechos humanos

    Características clínicas, histopatológicas y terapéuticas del cáncer de tiroides en Colombia: serie de 1.096 pacientes

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    Introducción: Los registros poblacionales de cáncer son una aproximación útil para determinar la magnitud del problema, pero son insuficientes como fuente de variables de interés para los clínicos y como generadores de hipótesis de investigación. Con el objetivo de identificar las características clínicas de los pacientes con cáncer de tiroides, el enfoque terapéutico inicial y los costos asociados con el manejo de la enfermedad, se implementó un registro específico en 10 ciudades de Colombia. Materiales y métodos: Se llevó a cabo un estudio descriptivo, observacional entre los años 2013 y 2015. Se desarrolló una herramienta web (www.colombiatiroides.com) consistente en 55 variables con características demográficas, histopatológicas, paraclínicas y terapéuticas, para registrar la información de los pacientes con diagnóstico de cáncer de tiroides que asistieron a consulta de endocrinología, medicina nuclear, cirugía de cabeza y cuello o cirugía endocrina. Resultados: Se incluyó información de 1.096 pacientes con cáncer de tiroides. El promedio de edad fue de 45,5 años; 86,3% eran mujeres; 93,6% de los casos correspondieron a carcinoma papilar. Se documentó asociación entre el tamaño tumoral y el compromiso capsular, extracapsular, linfovascular y ganglionar central y lateral (p=0,000). Los pacientes menores de 45 años presentaron mayor invasión ganglionar central (p=0,000) y lateral (p=0,003), mientras que en los mayores de 45 años los tumores multicéntricos (p=0,032) y la infiltración extracapsular (p=0,036) fueron más frecuentes. El costo directo aproximado por paciente/año fue de $2’532.687 (982 USD). Conclusiones: Los resultados de este registro muestran que el carcinoma diferenciado de tiroides de tipo papilar corresponde al 93,6% dentro de todos los tipos de cáncer de tiroides, proporción que es mayor a la de otras series reportadas en la literatura. El 89% de los pacientes con carcinoma diferenciado de tiroides fueron clasificados como de riesgo alto e intermedio de recurrencia, luego de la terapia inicial del cáncer de tiroides. En pacientes menores de 45 años, la enfermedad tiende a invadir por vía linfática, pero en los mayores de 45 años las extensiones locales son más frecuentes. Finalmente, el costo aproximado de la enfermedad es de USD 982 paciente/año.

    Worldwide comparison of survival from childhood leukaemia for 1995–2009, by subtype, age, and sex (CONCORD-2): a population-based study of individual data for 89 828 children from 198 registries in 53 countries

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    Background Global inequalities in access to health care are reflected in differences in cancer survival. The CONCORD programme was designed to assess worldwide differences and trends in population-based cancer survival. In this population-based study, we aimed to estimate survival inequalities globally for several subtypes of childhood leukaemia. Methods Cancer registries participating in CONCORD were asked to submit tumour registrations for all children aged 0-14 years who were diagnosed with leukaemia between Jan 1, 1995, and Dec 31, 2009, and followed up until Dec 31, 2009. Haematological malignancies were defined by morphology codes in the International Classification of Diseases for Oncology, third revision. We excluded data from registries from which the data were judged to be less reliable, or included only lymphomas, and data from countries in which data for fewer than ten children were available for analysis. We also excluded records because of a missing date of birth, diagnosis, or last known vital status. We estimated 5-year net survival (ie, the probability of surviving at least 5 years after diagnosis, after controlling for deaths from other causes [background mortality]) for children by calendar period of diagnosis (1995-99, 2000-04, and 2005-09), sex, and age at diagnosis (< 1, 1-4, 5-9, and 10-14 years, inclusive) using appropriate life tables. We estimated age-standardised net survival for international comparison of survival trends for precursor-cell acute lymphoblastic leukaemia (ALL) and acute myeloid leukaemia (AML). Findings We analysed data from 89 828 children from 198 registries in 53 countries. During 1995-99, 5-year agestandardised net survival for all lymphoid leukaemias combined ranged from 10.6% (95% CI 3.1-18.2) in the Chinese registries to 86.8% (81.6-92.0) in Austria. International differences in 5-year survival for childhood leukaemia were still large as recently as 2005-09, when age-standardised survival for lymphoid leukaemias ranged from 52.4% (95% CI 42.8-61.9) in Cali, Colombia, to 91.6% (89.5-93.6) in the German registries, and for AML ranged from 33.3% (18.9-47.7) in Bulgaria to 78.2% (72.0-84.3) in German registries. Survival from precursor-cell ALL was very close to that of all lymphoid leukaemias combined, with similar variation. In most countries, survival from AML improved more than survival from ALL between 2000-04 and 2005-09. Survival for each type of leukaemia varied markedly with age: survival was highest for children aged 1-4 and 5-9 years, and lowest for infants (younger than 1 year). There was no systematic difference in survival between boys and girls. Interpretation Global inequalities in survival from childhood leukaemia have narrowed with time but remain very wide for both ALL and AML. These results provide useful information for health policy makers on the effectiveness of health-care systems and for cancer policy makers to reduce inequalities in childhood survival

    Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an

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    Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð¥with constraintsð ð 𥠥 ðandð´ð¥ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis

    Measurement of the top quark forward-backward production asymmetry and the anomalous chromoelectric and chromomagnetic moments in pp collisions at √s = 13 TeV

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    Abstract The parton-level top quark (t) forward-backward asymmetry and the anomalous chromoelectric (d̂ t) and chromomagnetic (μ̂ t) moments have been measured using LHC pp collisions at a center-of-mass energy of 13 TeV, collected in the CMS detector in a data sample corresponding to an integrated luminosity of 35.9 fb−1. The linearized variable AFB(1) is used to approximate the asymmetry. Candidate t t ¯ events decaying to a muon or electron and jets in final states with low and high Lorentz boosts are selected and reconstructed using a fit of the kinematic distributions of the decay products to those expected for t t ¯ final states. The values found for the parameters are AFB(1)=0.048−0.087+0.095(stat)−0.029+0.020(syst),μ̂t=−0.024−0.009+0.013(stat)−0.011+0.016(syst), and a limit is placed on the magnitude of | d̂ t| &lt; 0.03 at 95% confidence level. [Figure not available: see fulltext.

    Differential cross section measurements for the production of a W boson in association with jets in proton–proton collisions at √s = 7 TeV

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    Measurements are reported of differential cross sections for the production of a W boson, which decays into a muon and a neutrino, in association with jets, as a function of several variables, including the transverse momenta (pT) and pseudorapidities of the four leading jets, the scalar sum of jet transverse momenta (HT), and the difference in azimuthal angle between the directions of each jet and the muon. The data sample of pp collisions at a centre-of-mass energy of 7 TeV was collected with the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0 fb[superscript −1]. The measured cross sections are compared to predictions from Monte Carlo generators, MadGraph + pythia and sherpa, and to next-to-leading-order calculations from BlackHat + sherpa. The differential cross sections are found to be in agreement with the predictions, apart from the pT distributions of the leading jets at high pT values, the distributions of the HT at high-HT and low jet multiplicity, and the distribution of the difference in azimuthal angle between the leading jet and the muon at low values.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio

    An embedding technique to determine ττ backgrounds in proton-proton collision data

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    An embedding technique is presented to estimate standard model tau tau backgrounds from data with minimal simulation input. In the data, the muons are removed from reconstructed mu mu events and replaced with simulated tau leptons with the same kinematic properties. In this way, a set of hybrid events is obtained that does not rely on simulation except for the decay of the tau leptons. The challenges in describing the underlying event or the production of associated jets in the simulation are avoided. The technique described in this paper was developed for CMS. Its validation and the inherent uncertainties are also discussed. The demonstration of the performance of the technique is based on a sample of proton-proton collisions collected by CMS in 2017 at root s = 13 TeV corresponding to an integrated luminosity of 41.5 fb(-1).Peer reviewe

    Measurement of t(t)over-bar normalised multi-differential cross sections in pp collisions at root s=13 TeV, and simultaneous determination of the strong coupling strength, top quark pole mass, and parton distribution functions

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    Penilaian Kinerja Keuangan Koperasi di Kabupaten Pelalawan

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    This paper describe development and financial performance of cooperative in District Pelalawan among 2007 - 2008. Studies on primary and secondary cooperative in 12 sub-districts. Method in this stady use performance measuring of productivity, efficiency, growth, liquidity, and solvability of cooperative. Productivity of cooperative in Pelalawan was highly but efficiency still low. Profit and income were highly, even liquidity of cooperative very high, and solvability was good
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