Use of Mutual Coupling to Decrease Parasitic Inductance of Shunt Capacitor Filters

In this paper, we propose and study several new designs of a shunt capacitor filter with two surface-mount technology capacitors. These designs make use of mutual inductance effects to increase the attenuation provided by the filter in the range of high frequencies where the filter behaves inductively. We provide lumped element circuitmodels for the proposed designs that allow identification of the key inductive parameters that determine the high-frequency performance of these filters. We obtain the equa- tions relating these parameters to the effective inductance of the filter, which can be used to compare the high-frequency behavior of different filter designs. We have fabricated and measured several compact shunt capacitor filters with improved performance at high frequencies. We have found that, compared with a shunt capacitor filter with one capacitor, a proper filter design with two capacitors can easily increase in 15–20 dB the high-frequency attenuation provided by the filter. This design also outperforms by 10–15 dB a traditional shunt capacitor filter with two capacitors closely placed. Moreover, this improvement is obtained with no increase in size, cost, or time of design of the filter.Ministerio de Economía Y Competitividad TEC2014-54097-

Development of sustainable processes for leather surface and structure defects minimization

Mestrado de dupla diplomação com Universidad Nacional de AsunciónIn pursuit of a greener future, the European Union and the United Nations encourage industries to renew their practices by adopting new sustainability principles and circular economy strategies. The waste produced by the leather industry takes part in this initiative by proposing a sustainable approach to minimizing leather’s superficial and structural defects. In this context, the objective of this work aims to minimize structural and superficial defects of discarded leather by employing leather hydrolysate and commercial fillers (nanoclay particles, expandable and glass microspheres) and employing the combination of additives that proves more effective in improving the leather’s mechanical properties. The reduction of superficial defects was achieved by combining 0.2%, 0.7% and 4.0% of expandable microspheres, glass microspheres, and nanoclay particles, respectively, and 20.0% polyurethane binder with each one of the fillers. However, the most effective additive was the addition of 25.0% leather hydrolysate and 10.0% transglutaminase (mTG), resulting in lighter, smoother, and more elastic leather without a significant dimensional variance. The effect of the former additive’s concentration over the leather’s mechanical properties was analyzed with a rotational central composite design 22 with 3 central points, defining 15.0 and 45.0% (OHW) leather hydrolysate, and 5.0 and 15.0% (OLW) mTG as boundary values. The ANOVA revealed that in the studied region, a significant effect of the concentration of mTG on the elongation percentage of leather. In contrast, the leather hydrolysate demonstrated a weak, yet significant, influence on the tensile strength. No significant effect of the additives on Young’s modulus was found. The mathematical model generated to estimate the elongation percentage values was validated, predicting a value close to the one obtained from the experimental procedure. Overall, this work demonstrated the applicability of leather hydrolysate in the minimization of leather defects.Na busca por um futuro mais verde, a União Europeia e as Nações Unidas incentivam as indústrias a renovarem as suas práticas de trabalho adotando princípios de sustentabilidade e estratégias de economia circular. Os resíduos produzidos pela indústria de curtumes fazem parte desta iniciativa, propondo-se uma abordagem sustentável para minimizar os defeitos superficiais e estruturais do couro. Neste contexto, o objetivo deste trabalho consiste em estudar estratégias para minimizar defeitos estruturais e superficiais de couros rejeitados, empregando hidrolisado de couro e cargas comerciais (partículas de nanoargila, partículas expansíveis e microesferas de vidro), incluindo a combinação de aditivos que se mostre mais eficaz em melhorar as propriedades de resistência mecânica do couro. A redução dos defeitos superficiais foi obtida combinando-se 0,2%, 0,7% ou 4,0% de microesferas expansíveis, microesferas de vidro e partículas de nanoargila, respectivamente, com 20,0% de um ligante de poliuretano. Não obstante, a estratégia mais eficaz consistiu na adição de 25.0% de hidrolisado de couro e 10.0% de transglutaminase (mTG), resultando num couro mais leve, macio e elástico, sem variação dimensional significativa. O efeito da concentração do hidrolisado sobre as propriedades mecânicas do couro foi analisado recorrendo a um desenho de experiências composto rotacional central 22 com 3 pontos centrais, definindo 15,0 e 45,0% (OHW) de hidrolisado e 5,0 e 15,0% (OLW) mTG como valores limite. A análise ANOVA revelou que na região estudada houve um efeito significativo da concentração de mTG sobre o alongamento do couro. Em contraste, o hidrolisado de couro demonstrou uma influência baixa, mas significativa, na resistência à tração. Nenhum efeito significativo destes aditivos foi observado para o módulo de Young. O modelo matemático gerado para estimar os valores percentuais de alongamento foi validado, prevendo um valor próximo ao obtido no procedimento experimental. No geral, este trabalho demonstrou a aplicabilidade do hidrolisado de couro na minimização dos defeitos do couro

EL IMPACTO MONETARIO DE LAS OPERACIONES DE TESORERIA: ANALISIS DE SUS DETERMINANTES FISCALES

Uno de los principales componentes de la Base Monetaria es el Crédito del Banco de la República al Gobierno Nacional. En este artículo se desarrolla un marco contable que permite visualizar los determinantes fiscales del impacto monetario de las operaciones de la Tesorería General de la República. Con base en el mismo, se extraen algunas conclusiones sobre el manejo de la política fiscal en Colombia en el período 1982-1988.OPERACIONES DE TESORERIA,

Cuantificación de la contribución de las fuentes de liquidez en el Sistema de Pagos de Alto Valor en Colombia: una aproximación preliminar

En el presente trabajo se realiza un análisis de estática comparativa relacionado con la cuantificación de la contribución de las distintas fuentes de liquidez que utilizan las entidades financieras en Colombia para cumplir (liquidar) sus obligaciones en el sistema de pagos de alto valor operado por el Banco de la República, al que se denomina sistema CUD. Con base en ello se evalúa también la incidencia de diversas políticas adoptadas por el banco central para propender por la liquidación más temprana de las operaciones y mitigar riesgos de liquidez en el sistema de pagos de alto valor. Para tales efectos, se consideró el comportamiento transaccional y de liquidez intradía de los participantes en el CUD correspondiente a dos periodos de marcadas diferencias tanto en la funcionalidad del sistema como en el entorno económico (mayo de 2002 y mayo de 2010), agregando la información por grupos de agentes más activos como son los bancos, comisionistas de bolsa y sociedades fiduciarias. En la metodología propuesta se asume que los participantes utilizan como fuente primaria su saldo en cuentas de depósito en el banco central (encaje) con el cual inician un día de operaciones, luego se calcula el valor efectivo de la liquidez provista por el Banco de la República u obtenida en el mercado monetario y se toma como residuo la dinámica de los pagos entre los agentes (liquidez de los pagos entrantes). Este análisis permite hacer una aproximación preliminar a la identificación de las estrategias utilizadas por las entidades financieras respecto al uso de cada una de las fuentes alternativas de liquidez en el sistema de pagos y a identificar riesgos potenciales que se derivan de las mismas para cada tipo de participantes y sobre el sistema en su conjunto. También provee elementos de juicio a las autoridades financieras para el diseño de políticas macroprudenciales que mitiguen el riesgo de liquidez y el riesgo sistémico.Sistema de pagos de alto valor, sistemas de liquidación bruta en tiempo real, fuentes de liquidez, encaje, provisión de liquidez del banco central, dinámica de pagos interbancarios. Classification JEL: E42, E41, E51, C70.

Grip force and force sharing in two different manipulation tasks with bottles

Grip force and force sharing during two activities of daily living were analysed experimentally in 10 right-handed subjects. Four different bottles, filled to two different levels, were manipulated for two tasks: transporting and pouring. Each test subject’s hand was instrumented with eight thin wearable force sensors. The grip force and force sharing were significantly different for each bottle model. Increasing the filling level resulted in an increase in grip force, but the ratio of grip force to load force was higher for lighter loads. The task influenced the force sharing but not the mean grip force. The contributions of the thumb and ring finger were higher in the pouring task, whereas the contributions of the palm and the index finger were higher in the transport task. Mean force sharing among fingers was 30% for index, 29% for middle, 22% for ring and 19% for little finger. Practitioner Summary: We analysed grip force and force sharing in two manipulation tasks with bottles: transporting and pouring. The objective was to understand the effects of the bottle features, filling level and task on the contribution of different areas of the hand to the grip force. Force sharing was different for each task and the bottles features affected to both grip force and force sharing.We wish to thank the Fundació Caixa-Castelló and the Universi- tat Jaume I for financial support through project P1-1B2009-40 and the Spanish Ministry of Economy and Competitiveness and FEDER through project DPI2014-60635-R. With the financial support of the Department of Mechanical Engineering and Con- struction at the Universitat Jaume I, Mark Andrews helped the authors with the English language edition of the manuscript

Asociación entre violencia doméstica y síntomas de depresión en la madre de niño lactante entre los 0 a 6 meses de edad. Un estudio secundario de la ENDES 2014-20

Objetivo: El presente estudio busca evaluar la relación entre la presencia de violencia doméstica y la presencia de síntomas depresivos en madres de 15 a 49 años de edad con niño lactante de 0-6 meses de edad. Metodología: Se realizó un estudio observacional transversal empleando una base secundaria de la ENDES del 2014 al 2019. Un total de 3860 mujeres de 15 a 49 años con hijo lactante de 0 a 6 meses fueron evaluadas. Nuestra variable dependiente fue la presencia de síntomas depresivos la cual fue explorada en el Cuestionario de Salud y se dicotomizó empleando >10 como punto de corte, en tanto nuestra variable independiente fue la violencia doméstica, la cual se evalúo en el Cuestionario Individual y se dicotomizó en base a si se reportó algún tipo de violencia (psicológico y/o verbal, física o sexual). Se describieron las variables categóricas mediante proporciones y la variable cuantitativa mediante la media, se empleó chi cuadrado para el análisis bivariado y el modelo de regresión de Poisson para calcular las razones de prevalencia (PR) y con ello evaluamos la fuerza de asociación. Resultados: El 23.95% de las mujeres incluidas en el estudio sufrieron violencia doméstica, la prevalencia de la violencia física, la violencia sexual y la violencia psicológica y/o verbal fue de 18.59%, 2.88% y 15.45% respectivamente. La presencia de síntomas depresivos estuvo presente en el 5.25% de las participantes. Las mujeres que sufrieron violencia doméstica tuvieron 2.64 mayor probabilidad de presentar síntomas depresivos que las mujeres no violentadas (IC 95% 1.75-3.98). Conclusión: Existe asociación entre la violencia doméstica y la presencia de síntomas depresivos en madres con niño lactante de 0 a 6 mesesObjective: The present study seeks to evaluate the relationship between the presence of domestic violence and the presence of depressive symptoms in mothers between 15 and 49 years of age with a nursing child between 0 and 6 months of age. Methodology: A cross-sectional observational study was carried out using a secondary database of the ENDES from 2014 to 2019. A total of 3,860 women aged 15 to 49 years with a nursing child aged 0 to 6 months were evaluated. Our dependent variable was the presence of depressive symptoms, which was explored in the Health Questionnaire and dichotomized using >10 as the cut-off point, while our independent variable was domestic violence, which was assessed in the Individual Questionnaire and dichotomized based on whether any type of violence (psychological and/or verbal, physical or sexual) was reported. The categorical variables were described by proportions and the quantitative variable by the mean, Chi square was used for the bivariate analysis and the Poisson regression model to calculate the prevalence ratios (PR) and with this we evaluated the strength of association. Results: 23.95% of the women included in the study suffered domestic violence, the prevalence of physical violence, sexual violence and psychological and/or verbal violence was 18.59%, 2.88% and 15.45% respectively. The presence of depressive symptoms was present in 5.25% of the participants. Women who suffered domestic violence were 2.64 times more likely to present depressive symptoms than non-violated women (95% CI 1.75-3.98). Conclusion: There is an association between domestic violence and the presence of depressive symptoms in mothers with infants from 0 to 6 months.Tesi

La teoría de los conjuntos-T aplicada al desarrollo de la competencia de modelado matemático

In this article we want to present parts of the theory of joint-T and how it is applied in higher education to develop the competence of mathematical modeling subjects. We explain how the theory can develop the skills of students. This theory is a response to the problems of learning of mathematics that originate in the curriculum designed to acquire information and not only to develop the math skills of students.En este artículo queremos dar a conocer apartes de la teoría de los conjuntos-T y cómo se aplica en la educación superior para desarrollar la competencia de modelado matemático de los sujetos. Esta teoría surge como respuesta a los problemas de enseñanza aprendizaje de las matemáticas que se originan en los programas curriculares diseñados para adquirir exclusivamente información y no para desarrollar las competencias matemáticas de los estudiantes

Morphologic and bioerosive features from an old marine highstand: the Cabililla archaeological shelter, Benzú, Ceuta

The micro-morphologic and bioerosive features, analyzed in the Benzú shelter (Ceuta), allow us to deduce an erosion marine surface elaborated onto dolomite triassic substrate. The Entobia-Gastrochaenolites Ichnoassociation and Entobia ichnofacies denote high energy coastal or shallow marine environment with low sedimentation rates. Two phases are differentiated in the evolution of these bioerosive structures: the first one defined by great borings of Gastrochaenolites, and the second recorded by bioerosive activity of Entobia and truncation of both, the previous borings and the cliff surface