Development of a DC-DC converter for DC bus voltage control of series connected device

The purpose of this work is to study voltage control and energy balance of a split DC bus topology within a power electronics equipment connected to the AC mains, such as UPS systems, wind power generators, active filters and FACTS devices. A typical configuration in such equipment has two mains connected converters sharing a common DC bus, one series connected and the other parallel connected. The DC bus is usually composed by a battery or a capacitor bank. In the proposed topology, the DC bus is divided in two sides, interconnected with a buck-boost converter, which controls power flow and DC voltage on both sides. © 2009 IEEE.

Recopilación de series históricas del producto bruto jujeño (1970/2011)

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América Latina y el Caribe: series regionales de cuentas nacionales a precios constantes de 1980

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América Latina y el Caribe: series regionales y oficiales de cuentas nacionales, 1950-1994

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América Latina y el Caribe: series estadísticas sobre comercio de servicios, 1980-1997

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América Latina y el Caribe: series regionales y oficiales de cuentas nacionales, 1950-1998

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América Latina y el Caribe: series estadísticas sobre comercio de servicios, 1980-2001

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Series históricas del crecimiento de América Latina

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América Latina y el Caribe: series regionales y oficiales de cuentas nacionales, 1950-2002

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América Latina y el Caribe: series históricas de estadísticas económicas 1950-2008

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Elementos teóricos del ajuste estacional de series económicas utilizando X-12-ARIMA y TRAMO-SEATS

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Liouville's theorem and power series for quaternionic functions

In recent years quaternionic functions have been an intense and prosperous object of research, and important results were determined [1]-[6]. Some of these results are similar to well known cases in one complex variable, op. cit. [5], [6]. In this paper the hypercomplex expansion of a function in a power series as well as determination of a Liouville's type theorem have been investigated to the quaternionic functions. In this case, it is observed that the Liouville's type theorem is true for second order derivatives, which differs from its classical version. © 2011 Academic Publications, Ltd.

Gastrointestinal cytomegalovirus disease in renal transplant recipients: A case series

The purpose of this article was to report a series of 23 renal transplant recipients with histologically proven and immunohistochemically confirmed cytomegalovirus (CMV) lesions in the gastrointestinal tract (GIT) and to assess the risk factors associated with severe disease/mortality. CMV patients (n=23) were allocated into two groups: those who died (n=6) and those considered cured (n=17). Overall mortality rate was 26% (6/23). Initial symptoms suggestive of lower GIT involvement were observed in all death cases and in 35.3% of those cured (p=0.01). Enterorrhagia was seen in 83.3% of the patients who died. Death risk increased twofold (RR 2 [1.13-3.52], p=0.01) when symptoms of lower GIT involvement were initially observed and sixfold when enterrohagia was present (RR 6 [1.1-35.9], p=0.001). Among death cases, mean time at diagnosis was significantly more distant (2002±2.9×2008±1.6, p=0.04). The difference in mortality rates seen as service practices changed along the years demonstrates the importance of early diagnosis. © 2011 John Wiley & Sons A/S.

Estudios de series temporales demográficas mediante modelos ARIMA de Box-Jenkins: una aplicación a series de la ciudad de Rosario, Argentina

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