138 research outputs found
Silicone Elastomer Blends
Silicones currently remain as a relatively new polymer material
class that has surpassed numerous benchmarks in regards to
functionality, applicability, and finally, costs. This paper aims to
provide a comprehensive review of the current standing of the
multifunctional silicone field. Namely, discussion regarding the
discovery, chemical structure, applications, and future work will
be carried out to provide the reader with a fundamental understanding
of the topic at hand. Nonetheless, with such a background
established, readers may begin to develop the necessary
mindset in incorporating the silicone polymer material class within
the fields of electronics, composites, and biomaterials.Ope
Brodsky y la Navidad : ?Dec 24, 1971?
Throughout his life, Joseph Brodsky clung stubbornly to a set of habits and tastes. One of his most outstanding and surprising loyalties was his writing a Christmas poem every year, which in time produced around thirty different pieces. Among these is the remarkable «Dec 24, 1971», his last Christmas poem before he left the Soviet Union, which contains a reference to his idea of «empire» ?a criticism of totalitarian regimes? plus an idea of Christianity as a religion of hospitality and brotherhood. KEYWORDS Brodsky; Christmas; Modernism; Empire; Hospitality
Factores que Influyen en la Importación de Bienes de Consumo en el Perú 2010 – 2018
La presente investigación se realizó con el objetivo de determinar la influencia del tipo de cambio real bilateral (USD/PEN) y el ingreso nacional disponible bruto sobre las importaciones de bienes de consumo del Perú, 2010 – 2018. A partir de información obtenida y procesada por el Banco Central de Reserva del Perú (BCRP) se presenta un modelo macroeconómico para determinar los efectos producidos en las importaciones de bienes de consumo, justificando su relevancia para la corrección de desequilibrios comerciales.
Un hallazgo importante es que el tipo de cambio real bilateral no aporta individualmente a las importaciones de bienes de consumo del Perú, consecuencia de un coeficiente de determinación (R2) de 2.97%. Sin embargo, el ingreso nacional disponible bruto explica en un 79.56% las importaciones de bienes de consumo, evidenciando una influencia muy significativa.
Al finalizar la investigación, se establece que el tipo de cambio real bilateral influye negativamente y en mayor proporción a las importaciones de bienes de consumo, caso contrario, el ingreso nacional disponible bruto tiene una influencia positiva y en menor proporción; contrastando un modelo predictivo fiable con un R2 ajustado de 87.37% para su aplicación en el Perú.Tesi
Calidad de servicio y su relación con la satisfacción del usuario en la IE Pública “Sagrado Corazón de Jesús 1207, La Molina, 2021”
La presente tesis, “Calidad del servicio y su relación con la satisfacción del usuario en la Institución Educativa Pública “Sagrado Corazón de Jesús 1207, La Molina, 2021” tuvo el propósito de analizar relación que hay entre la Calidad del servicio y Satisfacción del usuario en la IE que se desarrolló la investigación. Se utilizó un estudio descriptivo y con enfoque cuantitativo. Se utilizó un diseño de tipo correlacional, se contó con la población de 65 estudiantes de 5to de secundaria los mismos que conformaron la muestra que fue censal por conveniencia. La técnica de recolección de datos fue la encuesta y como instrumento fue el cuestionario sobre ambas variables, el cual constó de 21 ítems con cinco alternativas
Los datos recogidos se analizaron mediante pruebas paramétricas de análisis de datos como el Rho de Spearman con un valor de r=0.614 y sig 0.00 y también se utilizó el Alfa de Crombach con un valor de 0.975 para Calidad de Servicio y 0,952 para Satisfacción del usuario. Los resultados determinaron un nivel de significancia menor al valor de contraste establecido (p = 0,000 < 0,05), lo cual permitió aceptar la hipótesis general, demostrando estadísticamente que existe una relación moderada, positiva y significativa entre Calidad de servicio y la satisfacción del usuario en la IE pública “Sagrado Corazón de Jesús 1207, La Molina, 2021”.The present investigation, "Quality of service and its relationship with user satisfaction in the Public Educational Institution "Sagrado Corazon de Jesús 1207, La Molina, 2021" had the purpose of analyzing the relationship between Quality of service and User satisfaction in the EI in which the research was developed. For this, a descriptive study with a quantitative approach was achieved. A correlational type design was acquired, there were 65 students from the 5th year of secondary school according to the sample, the same 65 students from the 5th year of secondary school, the sample was census for convenience. The technique to collect the data was the survey and the instrument was the questionnaire on both variables, which consisted of 21 items with five alternatives.
The collected data was analyzed by means of parametric tests of data analysis such as Spearman's Rho with a value of r=0.614 and sig 0.00 and Crombach's Alpha was also used with a value of 0.975 for Service Quality and 0.952 for User Satisfaction. The results determined a level of significance lower than the established contrast value (p = 0.000 < 0.05), which allowed us to accept the general hypothesis, statistically demonstrating that there is a moderate, positive and significant relationship between Quality of service and customer satisfaction. user in the public IE “Sagrado Corazón de Jesús 1207, La Molina, 2021”
Pyroelectric thin films - Past, present, and future
Pyroelectrics are a material class that undergoes a change in polarization as the temperature of the system is varied. This effect can be utilized for applications ranging from thermal imaging and sensing to waste-heat energy conversion to thermally driven electron emission. Here, we review recent advances in the study and utilization of thin-film pyroelectrics. Leveraging advances in modeling, synthesis, and characterization has provided a pathway forward in one of the more poorly developed subfields of ferroelectricity. We introduce the complex physical phenomena of pyroelectricity, briefly explore the history of work in this space, and highlight not only new advances in the direct measurement of such effects but also how our ability to control thin-film materials is changing our understanding of this response. Finally, we discuss recent advances in thin-film pyroelectric devices and introduce a number of potentially new directions the field may follow in the coming years
Tratamiento odontopediátrico integral en parálisis cerebral. Reporte de un caso.
Report a case of girl of 4 years 3 months with congenital cerebral palsy distonic caused by citomegalovirus infectión with convulsive sindrome. The patient was referred to the pediatric dentistry departament at the dental school of the Universidad Nacional Mayor de San Marcos (UNMSM) for her odontopediatric treatment. The patient had an integral evaluation and treatment with no conventional dental procedures, without consciencious sedation. Having in consideration her age and cooperation level. Several medical and dental specialities was included. A significative diminishment in the convulsive frecuency after the dental treatment was referreal. Finally the of importance integrate odontology into multisciplinary team that works with this kind of patient is remarked.Se describe el caso de una niña de 4 años 3 meses de edad, con parálisis cerebral discinética con tendencia espástica causada por citomegalovirus con síndrome convulsivo, quien fue referida a la Clínica Integral del Niño de la Facultad de odontología de la Universidad Nacional Mayor de San Marcos (UNMSM) para su tratamiento. La paciente fue evaluada de manera integral con procedimientos odontológicos no convencionales sin sedación consciente, teniendo en cuenta la edad y el nivel de colaboración que presentaba, además de trabajar con un equipo multidisciplinario médico- odontológico. Se destaca el hecho que la paciente redujo significativamente la frecuencia de convulsiones luego del tratamiento odontológico, finalmente se resalta la importancia de integrar al odontólogo en el equipo multidisciplinario que trabaja con estos pacientes
Aprovechamiento de los Puntos Vive Digital Plus a través de la mediación de las TIC con modalidad B_Learning
One of the most important challenges facing the community of educators in this new digital era is to acquire newconcepts on the management and inclusion of learning methods through mediation of Information and CommunicationTechnologies. This process will focus on structuring a guide to improve the pedagogical practices of administrators inLive Digital Plus Points (L.D.P.P.); to begin with, the role changes in the teachers and students that this new digital erahas brought will be deducted; at the same time read the digital environment, encompassing several actions, such asidentifying, recognizing and understanding digital characteristics, thus achieving an effective mediation in the didactictriangle, teacher, content, student, through the B-Learning modality as one of the trends in education with more boomworldwide, for combining digital media in line with traditional methods of the classroom. There are different models ofB-Learning however we will be guided by the Face to Face Driver model: where the teacher promotes instruction andpromotes knowledge management through the mediation of ICTUno de los desafíos más importantes que deben enfrentar la comunidad de educadores en esta nuevaera digital es el adquirir nuevos conceptos sobre el manejo e inclusión de métodos de aprendizaje con mediaciónde las Tecnologías de la Información y Comunicación. Con este trabajo se propone estructurar una guía para mejorar las prácticas pedagógicas de los administradores en los Puntos Vive Digital Plus (P.V.D.P.). Se deducirán los cambios de roles en los docentes y alumnos que ha traído esta nueva era digital; al mismo tiempo leer el entorno digital, englobando varias acciones y herramienta que llevaran a identificar, reconocer y comprender características digitales, logrando así gestionar y organizar datos con una mediación efectiva en el triángulo didáctico, docente, contenido, estudiante; mediante la modalidad B-Learning; como una de las tendencias en educación con más auge a nivel mundial, por combinar medios digitales en línea con métodos tradicionales del aula. Existen distintos modelos de B-Learning, sin embargo, se orientarán con el modelo de Conductor Cara a Cara: donde el profesor impulsa la instrucción y fomenta la gestión del conocimiento
Plan financiero empresarial para Cementos Pacasmayo S.A.A.
En el primer capítulo se analiza el sector cementero a nivel mundial y sus principales
tendencias para dar un contexto global de éste, centrándose principalmente a nivel
latinoamericano. De igual forma, se evalúan los principales factores que condicionan su
desarrollo y los indicadores financieros comparativos de las empresas más representativas del
sector. En el segundo capítulo se evalúa a la empresa haciendo un recorrido por los
principales hitos de su historia. Para ello se ha contextualizado con los hechos que han
trascendido en el Perú y que han impactado de manera directa en las decisiones que ha
tomado la empresa y se analiza cómo ha plasmado su estrategia en sus principales pilares:
liderazgo en ventas en su zona de influencia con una importante red de distribución,
eficiencia en sus procesos productivos y mix de productos dirigidos a una base diversa de
clientes. Adicionalmente, se ha valorado la empresa mediante dos métodos: el flujo
descontado de caja y el método de valoración por múltiplos. En este último se ha considerado
el ratio precio/utilidad por acción y el ratio EV/EBITDA. En el tercer capítulo se ha
elaborado el plan financiero, con el objetivo de que la empresa genere valor para sus
accionistas y, asimismo, sea sostenible en el tiempo. Finalmente se brindan conclusiones y
recomendaciones sobre las acciones que la empresa podría tomar.
Palabras clave: Plan financiero, análisis financiero, sector cementero, estrategia, maximizar
valor.In the first chapter, the cement industry and its main trends are worldwide analyzed to
provide a global context of this sector. Focusing mainly in Latin America, the main factors
influencing the development of this industry and comparative financial indicators of the most
representative companies are evaluated. In the second chapter, the company is evaluated by
making a tour on the major milestones of its history, for it has been contextualized with the
events that have occurred in Peru and that have directly impacted on the decisions taken by
the company. It is also analyzed the way the company has set out its strategy on its main
pillars: sales leadership in its area of influence with a major distribution network, efficiency
in production processes and a mix of products that led to a diverse customer base. In addition,
the company has been valued using two methods: the discounted cash flow method and the
multiples valuation method. For this latter, the price / earnings per share ratio and EV /
EBITDA ratio are considered. In the third chapter, a financial plan has been developed, with
the aim that the company creates value for its shareholders and to also be sustainable over
time. Finally, conclusions and recommendations on actions the company might take are
givenTesi
Beyond substrates : strain engineering of ferroelectric membranes
Strain engineering in perovskite oxides provides for dramatic control over material structure, phase, and properties, but is restricted by the discrete strain states produced by available high-quality substrates. Here, using the ferroelectric BaTiO, production of precisely strain-engineered, substrate-released nanoscale membranes is demonstrated via an epitaxial lift-off process that allows the high crystalline quality of films grown on substrates to be replicated. In turn, fine structural tuning is achieved using interlayer stress in symmetric trilayer oxide-metal/ferroelectric/oxide-metal structures fabricated from the released membranes. In devices integrated on silicon, the interlayer stress provides deterministic control of ordering temperature (from 75 to 425 °C) and releasing the substrate clamping is shown to dramatically impact ferroelectric switching and domain dynamics (including reducing coercive fields to <10 kV cm and improving switching times to <5 ns for a 20 µm diameter capacitor in a 100-nm-thick film). In devices integrated on flexible polymers, enhanced room-temperature dielectric permittivity with large mechanical tunability (a 90% change upon ±0.1% strain application) is demonstrated. This approach paves the way toward the fabrication of ultrafast CMOS-compatible ferroelectric memories and ultrasensitive flexible nanosensor devices, and it may also be leveraged for the stabilization of novel phases and functionalities not achievable via direct epitaxial growth
Correlating Surface Crystal Orientation and Gas Kinetics in Perovskite Oxide Electrodes
Solid–gas interactions at electrode surfaces determine the efficiency of solid-oxide fuel cells and electrolyzers. Here, the correlation between surface–gas kinetics and the crystal orientation of perovskite electrodes is studied in the model system LaSrCoFeO. The gas-exchange kinetics are characterized by synthesizing epitaxial half-cell geometries where three single-variant surfaces are produced [i.e., LaSrCoFeO/LaSrGaMgO/SrRuO/SrTiO (001), (110), and (111)]. Electrochemical impedance spectroscopy and electrical conductivity relaxation measurements reveal a strong surface-orientation dependency of the gas-exchange kinetics, wherein (111)-oriented surfaces exhibit an activity >3-times higher as compared to (001)-oriented surfaces. Oxygen partial pressure ((Formula presented.))-dependent electrochemical impedance spectroscopy studies reveal that while the three surfaces have different gas-exchange kinetics, the reaction mechanisms and rate-limiting steps are the same (i.e., charge-transfer to the diatomic oxygen species). First-principles calculations suggest that the formation energy of vacancies and adsorption at the various surfaces is different and influenced by the surface polarity. Finally, synchrotron-based, ambient-pressure X-ray spectroscopies reveal distinct electronic changes and surface chemistry among the different surface orientations. Taken together, thin-film epitaxy provides an efficient approach to control and understand the electrode reactivity ultimately demonstrating that the (111)-surface exhibits a high density of active surface sites which leads to higher activity.R.G. and A.F. contributed equally to this work. R.G., A.F., A.L., T.C., E.E., and L.W.M. acknowledge the support of the National Science Foundation under Grant OISE-1545907. D.P. acknowledges funding from the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 797123. G.V. acknowledges the support of the National Science Foundation under Grant DMR-1708615. V.T. and T.I. acknowledge financial support from a Grant-in-Aid for Specially Promoted Research No. 16H06293) from MEXT, Japan and through the Japan Society for the Promotion of Science and the Solid Oxide Interfaces for Faster Ion Transport JSPS Core-to-Core Program (Advanced Research Networks). J.K. acknowledge the support by World Premier International Research Center Initiative (WPI), Ministry of Education, Culture, Sports, Science, and Technology of Japan (MEXT), Japan, Solid Oxide Interfaces for Faster Ion Transport (SOIFIT) JSPS/EPSRC (EP/P026478/1) Core-to-Core Program (Advanced Research Networks). This research used resources of the Advanced Light Source, which is a DOE Office of Science User Facility under contract no. DE-AC02-05CH11231
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