144 research outputs found
Effective mass theorems with Bloch modes crossings
We study a Schr{\"o}dinger equation modeling the dynamics of an electron in a
crystal in the asymptotic regime of small wavelength comparable to the
characteristic scale of the crystal. Using Floquet Bloch decomposition, we
obtain a description of the limit of time averaged energy densities. We make
rather general assumption assuming that the initial data are uniformly bounded
in a high order Sobolev spaces and that the crossings between Bloch modes are
at worst conical. We show that despite the singularity they create, conical
crossing do not trap the energy and do not prevent dispersion. We also
investigate the interactions between modes that can occurred when there are
some degenerate crossings between Bloch bands
Trabajo de investigación previo a la obtención del título de Magister en Administración de las Organizaciones de la Economía Social y Solidaria.
El estudio se focaliza en identificar las debilidades del control y supervisión en temas de gobierno cooperativo y gestión de riesgos, que actualmente se evidenciaría en la Superintendencia de Economía Popular y Solidaria (SEPS) en la supervisión de las cooperativas de ahorro y crédito, considerando que estas entidades de intermediación financiera deben gestionar sus actividades respetando los principios y valores universales del cooperativismo. En los últimos cinco años un significativo número de entidades entraron en proceso de liquidación, afectando directamente a los depositantes; evidenciando problemas en su control y demandando su mejora. La metodología empleada para el desarrollo de la investigación tiene un enfoque mixto con técnicas cualitativas y cuantitativas a través de datos numéricos y estadísticos de campo; así como con un análisis comparativo entre la normativa actual vigente de la Superintendencia de Economía Popular y Solidaria y la Superintendencia de Bancos. Por otro lado, se aplicaron encuestas a cooperativas de los segmentos 2,3 y 4 en materia de control y supervisión, que permitió evidenciar la falta de buenas prácticas y limitado control en temas de gobierno cooperativo y control de riesgos, así como una normativa laxa que atenta la estabilidad del sistema cooperativo. Del análisis anterior se identificó la necesidad de ajustes normativos y generación de un instrumento estandarizado de control por parte de la SEPS que optimice el control y supervisión respecto a buen gobierno cooperativo y gestión de riesgos. Se estableció indicadores que permitirían establecer técnicamente una calificación a las cooperativas supervisadas, en base a lo cual, el ente de control podría definir las estrategias de supervisión a aplicarse
Surgery of frontal sinus fractures. Epidemiologic study and evaluation of techniques
SummaryThe frontal sinus trauma is not rare and it is 8% of the facial fractures. It can affect the anterior and/or posterior plates, with or without hitting the nasofrontal duct. It has a large potential of complications and its management still being a controversy. Objective: To present the casuistic of fractures frontal sinus, the epidemiology and clinical and surgical management of frontal sinus fractures. Materials and Methods: Not randomized retrospective study of 24 patients with frontal sinus fractures Hospital of Clinics, School of Medicine Botucatu, São Paulo, Brazil. Results: From the 24 patients, we had 16 (66,6%) fractures of the extern plate and 8 (33,4%) of both. In 2 patients the nasofrontal duct was involved. Others facial fractures were associated in 20 (83,4%) cases and major lesions of the cerebral segment were found in 13 (54,2%). Subpalpebral incision was performed in the majority with satisfactory aesthetic results. The basis of the surgical treatment was reduction and fixation with different materials (steel wire, mononylon, titanium miniplates) and if necessary we used alogen implants or parietal bone to reconstruct the anterior plate. Conclusion: The principal cause of frontal sinus fractures is crashed car. The management depends of the complexity, because commonly there are cranioencephalic lesions associated. The surgical thecniques used are the incisions, bicoronal flap or browglabella, infra-orbital rim (“butterfly”), associated a endoscopy sinus surgery in cases of infection, cerobrospinal fluid leak and orbital complications
Proteção de dados e instituições de ensino: o que fazer com dados de alunos?
O presente artigo objetiva compreender como as instituições de ensino superior (IES) no Brasil podem adequar rotinas e procedimentos internos de tratamento de dados de alunos à Lei Geral de Proteção de Dados (LGPD). Parte-se do pressuposto de que a adequação de rotinas e de procedimentos de uma instituição a uma nova lei não é tarefa que demanda esforço de subsunção lógica apenas; na realidade, exige esforço criativo e negociado de adaptação. A partir do caso paradigmático da experiência de adequação da Fundação Getulio Vargas, este trabalho chegou à conclusão de que o tratamento de dados de alunos de uma IES pode se adequar à LGPD por meio da divisão didática de categorias de titulares, que variam conforme o tipo de relacionamento que o aluno tem com a instituição, e também da aplicação de regimes correspondentes de proteção de dados
Conceptual changes in ameloblastoma : Suggested re-classification of a "veteran" tumor
Objectives: The merging of ameloblastoma (AM) with mural unicystic ameloblastoma (UAM-M) was suggested by the 2017 WHO based on similar treatment needs. In an international multicenter study, we investigated the characteristics of their merged product (merged-AM) and raised the possibility of unifying AM and UAM (total-AM). Materials and methods: AM and UAM (luminal/intraluminal/mural), separate and combined, were analyzed for demographic/clinical/radiological features. ANOVA and chi-square tests were followed by univariate and multivariate analyses, and significance was set at p .05). Conclusions: Merged-AM partially differed from AM, but differences appeared to diminish in an age/time-wise manner. Merged-AM and total-AM were nearly indistinguishable. Therefore, AM and UAM may be considered a continuous spectrum of one type of tumor, further necessitating revision of the treatment approaches.Peer reviewe
Clasificación de tutoriales en YouTube basándonos en el análisis de sentimientos realizados a sus comentarios
The flow of information arises day by day through the Internet in a continuous way thanks to the constant interactions between users, these interactions present feelings that can be positive or negative. This helps social media content creators a lot to understand how useful what they do is for their followers, and if these are a large number, an analysis done by a single person is not enough. For this, it is necessary to use tools that operate with large amounts of data, such as BERT, which is a model that helps analyze sentiments and classify comments based on what one of them expresses. In this work, this model will be used for the classification of YouTube comments and the classification of videos on this same platform, evaluating these videos according to their content and helping viewers to choose the videos if they help them concerning what is expected. find searching. This work will also use future metrics and suggestions for the proposal.El flujo de información surge día a día mediante internet de manera continua gracias a las constantes interacciones presentes entre los usuarios, estas interacciones presentan sentimientos que pueden ser positivos o negativos. Esto ayuda mucho a los creadores de contenido de las redes sociales a comprender cuan útil es lo que ellos hacen para sus seguidores, y es que, si estos son un gran número, un análisis hecho por una sola persona no es suficiente. Para ello es necesario el uso de herramientas que operan con grandes cantidades de datos como BERT, que es un modelo que ayuda al análisis de sentimientos y clasificación de comentarios basados en lo que expresa uno de estos. En este trabajo se usará este modelo para la clasificación de comentarios de YouTube y clasificación de videos de esta misma plataforma, valorando estos videos según su contenido y ayudando a los espectadores a elegir los videos si es que estos lo ayudarán con respecto a lo que se encuentran buscando. Se harán además uso de métricas y de sugerencias futuras para la propuesta mencionada en este trabajo
W/B Planner -Solucionador para Roteamento de Veículos no Transporte Fretado de Passageiros
Companies of chartered transport of passengers need to manage routes with boarding points, based on the location of the passengers. As the number of routes grow, the task of manually manage and optimize routings becomes inviable. The vehicle routing problem characterizes inside this scenario, branching into specific problems, that need different solutions for each case. Meta-heuristics are usually used to build solver algorithms for these problems. Constraint programming was chosen for helping build the solver. The main objective of the work was, to develop a system performing the solution of routings in an automatized way, by utilization of constraint programming and meta-heuristic algorithms. To minimize transport costs, travel time, and maximize the use of vehicles in an efficient and planned manner. The tests were carried out in conjunction with a routing administrator, to validate the use of the application within the research field. From the evaluations made, they demonstrated the utility of the software within its purpose. Of which it was observed that the product of this research, helped in the construction of an automated fleet consulting tool, being able to dynamically point out the distribution and operationality of a fleet of chartered vehicles in the transportation of passengers
Meteorological influences on solar energy production in a coastal Amazon region
A study was conducted with a photovoltaic distributed generation system in São Luís, Brazil, to determine the influence of meteorological variables on the generation of energy. The methodology is composed of three stages: the first corresponds to the obtaining, organization, and treatment of the data; the second involves the application of mathematical models to determine the yield, operating temperature, nominal power, and estimated power; and the third is to generate the correlations obtained between the monitored climatic variables, whether on an hourly, daily, monthly, or annual scale. For an average temperature of 27.50ºC in March, it was verified that the ultraviolet radiation was 5.06, while the average of the total radiation was 481.01 W.m-2. The maximum peak temperature was 27.88°C at noon, while the ultraviolet radiation was 8.55 and total radiation was 794.97 W.m-2. At this average temperature variation of 0.38°C, there is a variation of 313.96 W.m-2. It is concluded that, because São Luís is very close to the equator, the conditions to produce the system are favorable, mainly because, on average, there were no abrupt changes in temperature and radiation for the period studied. Even in the wintry period, the production behaved within the parameters designed
A thermocatalytic perovskite-graphene oxide nanofiltration membrane for water depollution
A novel nanofiltration membrane, whose active layer consists of 98.6 wt% of a thermocatalytic perovskite with composition Sr0.85Ce0.15FeO3-δ (CSF), 1.0 wt% of graphene oxide (GO), and 0.4 wt% of a humic acid-like (HAL) crosslinker, was deposited over a commercial flat-sheet polyethersulfone support with good reproducibility by a simple 1-step coating procedure. The synergistic coupling of CSF and the crosslinked GO resulted in an improved catalytic activity for bisphenol A (BPA) abatement as a model pollutant. The thermocatalytic CSF/GO/HAL (GOT) membrane was tested in a nanofiltration crossflow apparatus with a model BPA solution and with a real urban wastewater treatment plant effluent. Its performances were compared with those of a HAL crosslinked GO (GOHAL) reference membrane. The GOT membrane presented high rejection towards BPA, antifouling properties, and stability under the filtration conditions. Moreover, when compared to the GOHAL reference, the thermocatalytic GOT membrane was able to reduce the concentration of BPA and the total organic carbon in the feed during filtration. Hence, the GOT membrane appears to have high potential in water treatment due to its multifunctional characteristics, which include molecular sieving, thermocatalytic oxidation of organic pollutants, and self-cleaning properties. Additionally, the membrane material showed no significant toxicity to the aquatic model organisms Raphidocelis subcapitata, Aliivibrio fischeri, and Daphnia magna at concentrations below 50 ppm.Fil: Bortot Coelho, Fabricio E.. Università di Torino; Italia. Liqtech International A/s; DinamarcaFil: Nurisso, Federica. Università di Torino; Italia. Aalborg University; DinamarcaFil: Boffa, Vittorio. Aalborg University; DinamarcaFil: Ma, Xianzheng. Aalborg University; DinamarcaFil: Rasse Suriani, Federico Ariel Osvaldo. Aalborg University; Dinamarca. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Roslev, Peter. Aalborg University; DinamarcaFil: Magnacca, Giuliana. Università di Torino; ItaliaFil: Candelario, Victor. Liqtech International A/s; DinamarcaFil: Deganello, Francesca. Istituto Per Lo Studio Dei Materiali Nanostrutturati, Rome; ItaliaFil: La Parola, Valeria. Istituto Per Lo Studio Dei Materiali Nanostrutturati, Rome; Itali
Acionamento inteligente de iluminação e refrigeração em salas de aula por meio do monitoramento de pessoas presentes / Intelligent activation of illumination and refrigeration in classrooms by means of monitoring present people
Este artigo apresenta um sistema elaborado por meio da plataforma de prototipagem eletrônica Arduino, programado para realizar o monitoramento de pessoas presentes em sala e posteriormente efetuar o acionamento e/ou desligamento dos circuitos de iluminação e refrigeração de uma sala, logo após identificar a quantidade mínima de pessoas estipuladas na programação. O objetivo desse trabalho é desenvolver um método de baixo custo para combater o desperdício de energia elétrica nos blocos de salas de aulas do Campus Belém da Universidade Federal do Pará (UFPA). É mostrado no artigo, por meio de números, que o protótipo desenvolvido apresenta viabilidade de implementação em escala real uma vez que apresenta bons resultados quanto à economia financeira para a UFPA gerada pelo correto uso da energia elétrica no Campus quando está em operação
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