Parametric amplification of optical phonons

Amplification of light through stimulated emission or nonlinear optical interactions has had a transformative impact on modern science and technology. The amplification of other bosonic excitations, like phonons in solids, is likely to open up new remarkable physical phenomena. Here, we report on an experimental demonstration of optical phonon amplification. A coherent mid-infrared optical field is used to drive large amplitude oscillations of the Si-C stretching mode in silicon carbide. Upon nonlinear phonon excitation, a second probe pulse experiences parametric optical gain at all wavelengths throughout the reststrahlen band, which reflects the amplification of optical-phonon fluctuations. Starting from first principle calculations, we show that the high-frequency dielectric permittivity and the phonon oscillator strength depend quadratically on the lattice coordinate. In the experimental conditions explored here, these oscillate then at twice the frequency of the optical field and provide a parametric drive for lattice fluctuations. Parametric gain in phononic four wave mixing is a generic mechanism that can be extended to all polar modes of solids, as a new means to control the kinetics of phase transitions, to amplify many body interactions or to control phonon-polariton waves

Metastable ferroelectricity in optically strained SrTiO3SrTiO_3

Fluctuating orders in solids are generally considered high-temperature precursors of broken symmetry phases. However, in some cases these fluctuations persist to zero temperature and prevent the emergence of long-range order, as for example observed in quantum spin and dipolar liquids. $SrTiO_3$ is a quantum paraelectric in which dipolar fluctuations grow when the material is cooled, although a long-range ferroelectric order never sets in. We show that the nonlinear excitation of lattice vibrations with mid-infrared optical pulses can induce polar order in $SrTiO_3$ up to temperatures in excess of 290 K. This metastable phase, which persists for hours after the optical pump is interrupted, is evidenced by the appearance of a large second-order optical nonlinearity that is absent in equilibrium. Hardening of a low-frequency mode indicates that the polar order may be associated with a photo-induced ferroelectric phase transition. The spatial distribution of the optically induced polar domains suggests that a new type of photo-flexoelectric coupling triggers this effect

Molecular and nanostructural mechanisms of deformation, strength and toughness of spider silk fibrils

Spider silk is one of the strongest, most extensible and toughest biological materials known, exceeding the properties of many engineered materials including steel. Silks feature a hierarchical architecture where highly organized, densely H-bonded beta-sheet nanocrystals are arranged within a semi-amorphous protein matrix consisting of 31-helices and beta-turn protein structures. By using a bottom-up molecular-based mesoscale model that bridges the scales from Angstroms to hundreds of nanometers, here we show that the specific combination of a crystalline phase and a semi-amorphous matrix is crucial for the unique properties of silks. Specifically, our results reveal that the superior mechanical properties of spider silk can be explained solely by structural effects, where the geometric confinement of beta-sheet nanocrystals combined with highly extensible semi-amorphous domains with a large hidden length is the key to reach great strength and great toughness, despite the dominance of mechanically inferior chemical interactions such as H-bonding. Our model directly shows that semi-amorphous regions unravel first when silk is being stretched, leading to the large extensibility of silk. Conversely, the large-deformation mechanical properties and ultimate tensile strength of silk is controlled by the strength of beta-sheet nanocrystals, which is directly related to their size, where small beta-sheet nanocrystals are crucial to reach outstanding levels of strength and toughness. Our model agrees well with observations in recent experiments, where it was shown that a significant change in the strength and toughness can be achieved solely by tuning the size of beta-sheet nanocrystals. Our findings unveil the material design strategy that enables silks to achieve superior material performance despite simple and inferior constituents, resulting in a new paradigm in materials design where enhanced functionality is not achieved using complex building blocks, but rather through the utilization of simple repetitive constitutive elements arranged in hierarchical structures

Desarrollo, producción y comercialización de producto para filtrar el agua

EmprendimientoPropuesta de creación de empresa dedicada al desarrollo, producción y comercialización de producto para filtrar el agua, para la que fue necesario realizar un estudio de mercados, un estudio tecnico, estudio administrativo y legal y por ultimo un estudio financiero el cual determina la viabilidad del proyecto. Logrando con esto que la empresa constituida sea factible para los constituyentes de estaINTRODUCCIÓN 1. GENERALIDADES 2. ESTUDIO DE MERCADOS 3. ESTUDIO TÉCNICO 4. ESTUDIO ADMINISTRATIVO 5. ESTUDIO FINANCIERO 6. CONCLUSIONES 7. RECOMENDACIONESPregradoIngeniero Industria

The use of a rubric as a self-assessment tool to improve english writing proficiency.

122 p.Este proyecto de investigación busca describir el impacto de la implementación de una rejilla de auto-evaluación para el análisis de errores en los escritos de estudiantes con nivel A1- A2 MCER. Asimismo, describe los errores más comunes en los escritos de los aprendices y cómo el proveer una herramienta de auto-evaluación influye en la eficacia para la corrección de escritos. La población de este estudio fueron 90 estudiantes del grado décimo de tres colegios distritales. Esta investigación tuvo una duración de 8 meses e incluyó diferentes etapas: análisis de necesidades, diseño e implementación de estrategias, recolección y análisis de datos. Los resultados mostraron que la implementación de la estrategia contribuyó a la reducción de ciertos errores en los escritos de la población de estudio.This action research Project aims to describe the effects of implementing a rubric as a self-assessment tool for Error Analysis on EFL A1-A2 Students’ Written Compositions. Likewise, it describes what the most common errors in students’ written compositions are; and the impact of a tool to enhance self-efficacy at the moment of self-assessing written compositions. The population were 90 tenth-graders from three public schools in Bogota. This research lasted 8 months including different stages: needs analysis; design and strategy implementation; data collection and data analysis. The results showed that the strategy contributed to the reduction of some errors in the population’s written compositions.Magister en didáctica del inglés para el aprendizaje autodirigidoMaestríaMedia (10 y 11)Humanidades, lengua castellana e idiomas extranjerosEstudiantesMixtoEvaluaciónProcesos de aprendizajeAulaInstituciónProducción escrita, análisis de errores, autonomía, autoevaluación, enseñanza centrada en el alumno, evaluaciones por matrices

El cardiotangram como estrategia pedagógica en el aprendizaje de las razones trigonométricas para los estudiantes de grado décimo del Colegio Nuestra Señora del Rosario Sogamoso.

El presente trabajo de aplicación inicia con el Resumen analítico Especializado, enseguida podemos encontrar la introducción, justificación, Descripción del problema que describe la situación y población a trabajar, Luego se encuentra la pregunta de investigación, Siguiendo con el desarrollo del trabajo se presenta los objetivos general y específicos que identifican el trabajo a realizar; también se encuentra el marco teórico donde se describe, el cardiotangram, las razones trigonométricas, aprendizaje significativo. Además, se encuentra la línea de investigación Según “Lineamientos para trabajos de grado de las especializaciones ECEDU; el diseño metodológico compuesto por el Enfoque y tipo de Estudio, fases para el desarrollo de la propuesta y por ultimo las fuentes o referentes bibliográficosThis application work starts with the Specialized Analytical Summary, then we can find the introduction, justification, Description of the problem that describes the situation and the population to be worked on, Then the research question is found, Following the development of the work the objectives are presented general and specific that identify the work to be done; There is also the theoretical framework where it is described, the cardiotangram, the trigonometric ratios, significant learning. In addition, there is the line of research According to "Guidelines for degree works of the ECEDU specializations; the methodological design composed of the Approach and type of Study, phases for the development of the proposal and finally the sources or bibliographic reference

Incidence of acute pyelonephritis in pregnancy, microbiological cure rate and maternal outcomes at the Foscal Floridablanca Clinic, Colombia

Introducción: La pielonefritis aguda definida como bacteriuria significativa asociada a inflamación del parénquima, los cálices y/o la pelvis renales, es la complicación infecciosa más frecuente durante el embarazo y la primera causa de hospitalización de origen no obstétrico. Objetivo: Determinar la incidencia de pielonefritis aguda en el embarazo, tasa de curación microbiológica y resultados maternos en gestantes hospitalizadas en la clínica Foscal en Floridablanca, Colombia. Materiales y métodos: Estudio observacional con una cohorte cerrada de gestantes con diagnóstico clínico de pielonefritis aguda y urocultivo positivo. Los datos presentados tuvieron una estimación con un nivel de confianza del 95%. Para el análisis de los datos se usó el paquete estadístico STATA 14.0. Resultados: Se incluyeron 50 gestantes hospitalizadas en el servicio de obstetricia de la clínica Foscal en el 2018. Se estimó una incidencia de 19,8 casos por cada 1.000 nacimientos año, se aislaron Escherichia coli BLEE- y Klebsiella pneumoniae BLEE- en un 62% y 10% respectivamente. La tasa de curación microbiológica fue de 4,6 casos de pielonefritis aguda por cada 100 días de seguimiento, IC 95% (3,4-6,2) y la tasa de persistencia fue de 5,6 casos por cada 100 días de seguimiento, IC 95% (2,1-12,4). La amenaza de parto pretérmino se presentó en el 8% de los casos. Conclusión: La pielonefritis aguda durante el embarazo ha sido considerada como una importante causa de morbilidad materna y perinatal. A través de esta investigación se documentó la incidencia de esta patología en la Clínica Foscal. Igualmente, se describieron las características de la población estudiada y los resultados maternos asociados a este problema de salud. Se descata como el primer estudio tanto local y como nacional que intentó determinar los factores asociados a la curación microbiológica.1. RESUMEN DEL PROYECTO ……………………………………… 8 2. INTRODUCCIÓN …………………………………………………….. 12 3. PLANTEAMIENTO DEL PROBLEMA ……………………………. 13 4. JUSTIFICACIÓN …………………………………………………….. 13 5. MARCO TEÓRICO ………………………………………………….. 5.1 Estado del arte …………………………………………………... 14 34 6. PROTOCOLO DE INVESTIGACIÓN ……………………………… 6.1 Pregunta de investigación ……………………………………… 6.2 Objetivo general …………………………………………………. 6.3 Objetivos específicos …………………………………………… 6.4 Metodología ……………………………………………………… 6.4.1 Diseño epidemiológico ……………………………………….. 6.4.2 Población a estudio ………………………………………….. 6.4.3 Criterios de inclusión …………………………………………. 6.4.4 Criterios de exclusión ………………………………………… 6.5 Cálculo de la muestra y muestreo …………………………….. 6.6 Procedimiento …………………………………………………… 6.8 Depuración de datos y plan de análisis ………………………. 6.9 Operacionalización de las variables …………………………... 40 40 40 41 41 41 41 42 42 42 42 45 47 7. DISPOSICIONES VIGENTES ……………………………………… 47 8. RESULTADOS ………………………………………………………. 50 9. DISCUSIÓN ………………………………………………………….. 70 10. CONCLUSIÓN ……………………………………………………….. 77 11. BIBLIOGRAFÍA ……………………………………………………… 79EspecializaciónIntroduction: Acute pyelonephritis, defined as significant bacteriuria associated with inflammation of the parenchyma, calyces and/or renal pelvis, is the most frequent illness found during pregnancy due to its infectious base and becoming the first cause of hospitalization owing to its non-obstetric origin. Objective: To determine the frequency of acute pyelonephritis during pregnancy, microbiological cure rate and maternal outcomes in pregnant women hospitalized at the Foscal Clinic in Floridablanca, Colombia. Materials and methods: Observational study with a closed cohort of 50 pregnant women diagnosed with acute pyelonephritis. The data presented, had an estimate with a confidence level of 95%. For the analysis of the outcome, the statistical package STATA 14.0 was used. Results: Fifty pregnant women hospitalized in the obstetrics service of the Foscal Clinic in 2018 were included in the research. An incidence of 19.8 cases per 1,000 births per year was estimated, the most frequently isolated germs were Escherichia coli and Klebsiella pneumoniae in 62% and 10% respectively. The microbiological cure rate was 4.6 cases of acute pyelonephritis was found for every 100 days of followup, 95% CI (3,4-6,2) and a microbiological persistence rate of 5,6 cases for every 100 days of follow-up, 95% CI (2,1-12,4). The preterm labor ocurred in 8% of cases. Conclusion: Acute pyelonephritis during pregnancy has been considered an important cause of maternal and perinatal morbidity. Through this research, the incidence of this pathology at the Foscal Clinic was documented. The characteristics of the study population and the maternal outcomes associated with this health problem were also described. It is ruled out as the first study, both local and national, that attempted to determine the factors associated with microbiological cure

Population structure and production of fruits of the palm Dictyocaryum Lamarckianum as a conservation strategy of the yellow-eared parrot ognorhynchus icterotis

La palma Dictyocaryum lamarckianum es una especie dominante de los bosques montanos que forma extensos rodales. En la localidad de la Reserva Natural Las Palmeras en Cubarral Meta, se encontró que esta palma es el hábitat de la población del loro orejiamarillo (Ognorhynchus icterotis), convirtiéndose en su principal fuente de alimento y sitio de anidación. Teniendo en cuenta la importancia ecológica de la palma, caracterizamos su estructura poblacional y evaluamos la producción de frutos como recurso clave para la conservación del loro orejiamarillo. Se establecieron dos parcelas de una hectárea cada una, se tomaron los datos morfológicos y estructurales del total de individuos, se realizó análisis de componentes principales y se establecieron las categorías de la población. Se colectaron tres racimos para registrar cantidad y peso de los frutos, y registró la producción de frutos en un rodal de 10 hectáreas, durante los años 2015 y 2018. Se encontró una población de 16 993 individuos en dos hectáreas, distribuidos en plántulas con 11 131 individuos (65,5%), juveniles con 5 851 individuos (34,24%) y Adultos con 11 individuos (0,06%). La producción de frutos tiene grandes fluctuaciones anuales con promedio de 153 081 frutos, el año de mayor producción fue 2017 con 342 560 frutos, mientras que en el año 2016 tan sólo se produjo 19 269 frutos. El manejo de la palma D. lamarckianum como estrategia para la conservación del loro orejiamarillo debe garantizar la presencia de individuos adultos e incluir actividades de rescate de plántulas para sembrar en otras áreas. Para contrarrestar los periodos de escasez de frutos se debe enriquecer la zona con otras especies que proporcionan alimento para el Loro orejiamarillo.The Dictyocaryum lamarckianum palm is a dominant species of montane forests that forms extensive stands. In the site of Las Palmeras Natural Reserve in Cubarral Meta, it was found that this palm is the habitat of the population of the yellow-eared parrot (Ognorhynchus icterotis), becoming its main source of food and nesting site. Due to the ecological importance of the palm, we characterize its population structure and evaluate the production of fruits as a key resource for the conservation the yellow-eared parrot. Two parcels of one hectare each were established, morphological and structural data of all individuals was taken, Principal Components Analysis was carried out and the population categories were established. Three racemes were collected to register the quantity and weight of the fruits, and the production fruit was recorded in stand the ten hectares, from the year 2015 to 2018. A population of 16 993 individuals was found in two hectares, distributed in seedlings with 11,131 individuals (65.5%), juveniles with 5 851 individuals (34.24%) and Adults with 11 individuals (0.06%). The production of fruits had large annual fluctuations with an average of 153 081 fruits, the year of greatest production was 2017 with 342 560 fruits, while in 2016 only 19 269 fruits were produced. The management of the D. lamarckianum palm as a strategy for the conservation of the yellow-eared parrot should guarantee the presence of adult individuals and should include seedling rescue activities to plant in other areas. To counteract the periods of scarcity of fruits, the zone should be enriched with other species that provide food for the Yellow-eared Parrot

Alguns aspectos da Revolução Russa nas páginas das revistas ilustradas do Brasil Republicano

The purpose of this article is to problematize the different readings of the events that led to the taking of power by the Bolsheviks in the Russian Revolution in 1917 present in the Brazilian illustrated magazines, analyzing the representations of the images and texts of the printed ones that circulated especially in the capital of the newly proclaimed Brazilian Republic. The representations specially elaborated by the Illustrated Journals contributed to the formation of "visions" and different interpretations of what happened in those months of war and revolution. Images and speeches that allow us to analyze the construction of a singular discourse on History in the pages of the magazines of the Brazilian Republic. How the magazines Careta, Fon Fon, o Malho, Eu sei Tudo, A Leitura para Todos, Para Todos and A Revista da Semana presented the Russian Revolution of 1917? What was the type of information disseminated in such journals? And to what extent was the quality of this information distant from other sources, such as the working-day newspapers or daily newspapers of the major press at the time? What is the contribution of illustrated periodicals in understanding how the news and facts about Russia came to Brazil and were widespread? What are the main topics dealt with by magazines in dealing with the theme of the Russian Revolution? What stands out?El artículo analiza las diferentes lecturas de los eventos que llevaron a la toma del poder por los bolcheviques en la Revolución Rusa de 1917 en las revistas ilustradas brasileñas, analizando las representaciones en las imágenes y textos de la prensa que circulaban principalmente en la capital de la recientemente proclamada República Brasileña. Las representaciones especialmente elaboradas por las revistas ilustradas contribuyeron a la formación de "visiones" y diferentes interpretaciones sobre lo que sucedió en esos meses de guerra y revolución. Imágenes y discursos que nos permiten analizar la construcción de un discurso singular sobre la historia en las páginas de las revistas de la República de Brasil. ¿Cómo presentaron la revolución rusa de 1917 la revista Careta, Fon-Fon, O Malho, Eu sei tudo, A Leitura para todos, Para Todos y A Revista da Semana? ¿Cuál fue el tipo de información difundida en tales revistas? ¿Y hasta qué punto la calidad de esta información difiere de otras fuentes, como los periódicos de los trabajadores o los diarios de la gran prensa de la época? ¿Cuál es la contribución de las revistas ilustradas para comprender cómo las noticias y los hechos sobre Rusia llegaron a Brasil y se difundieron? ¿Cuáles son los principales temas tratados por las revistas cuando se trata el tema de la Revolución Rusa? ¿Qué se destaca?O artigo problematiza as diferentes leituras dos acontecimentos que levaram a tomada de poder pelos bolcheviques na revolução russa de 1917 presentes nas revistas ilustradas brasileiras, analisando as representações nas imagens e textos dos impressos que circulavam sobretudo na capital da recém proclamada República brasileira. As representações especialmente elaboradas pelas revistas ilustradas contribuíram para a formação de “visões” e diferentes interpretações sobre o ocorrido naqueles meses de guerra e revolução. Imagens e discursos que nos permitem analisar a construção de um discurso singular sobre a História nas páginas das revistas da República brasileira. Como as revistas Careta, FonFon, o Malho, Eu sei Tudo, A Leitura para Todos, Para Todos e A Revista da Semana apresentaram a Revolução Russa de 1917? Qual era o tipo de informação disseminada em tais periódicos? E em que medida a qualidade dessas informações se distanciava de outras fontes, como os jornais operários ou jornais diários da grande imprensa da época? Qual a contribuição dos periódicos ilustrados no entendimento de como a notícia e os fatos sobre a Rússia chegaram ao Brasil e eram difundidos? Quais as principais tópicas trabalhadas pelas revistas ao tratar do tema da Revolução Russa? O que se destaca

Pengaruh Instruktur Pelatihan, Metode Pelatihan, Materi Pelatihan dan Waktu Pelatihan Terhadap Intensifikasi Pengetahuan Relawan Pajak (Studi Kasus pada Kantor Wilayah Direktorat Jenderal Pajak Jawa Tengah 2)

Intensification of knowledge of tax volunteers will have a positive impact in providing assistance to taxpayers, then taxpayers do not hesitate to be accompanied in reporting their tax obligations because taxpayers do not need to conduct tax consultations with the Tax Office ( KPP or KP2KP) so that for the mission of binding the level of awareness and compliance of taxpayers. Therefore, efforts are needed on how to make the function of Tax Volunteers maximize their role. This study aims to examine the effect of training instructors, training methods, training materials and training time on the knowledge intensification of Tax Volunteers. This study uses a quantitative approach with a sample of 132 Tax Volunteers from the Central Java DGT Office 2. The type of data used is primary data obtained by distributing questionnaires. The data analysis technique used multiple linear regression analysis. The results of this study indicate that the variables of training instructors, training methods and materials have no effect on the knowledge intensification of tax volunteers, but the time has a significant effect on the knowledge intensification of tax volunteers. Keywords: Training Instructor, Training Materials, Training Time, Knowledge Intensification of Tax Volunteers