The control of the input voltage of DC-DC converters is frequently required in photovoltaic applications. In this special situation, unlike conventional converters, the output voltage is constant and the input voltage is controlled. This paper deals with the analysis and the control of the buck converter with constant output voltage and variable input.

This paper presents an approach for teaching and learning dc-dc converter design using MathCAD. MathCAD provides advantages that greatly improve teaching and learning process especially when long and complicated design equations are involved such as those found in dc-dc converters. A design example using Excel is presented and then compared with the same example using MathCAD. Experience learne...

Step-up dc-dc converters have to cope with extremely low input voltages when used in combination with energy harvesting sources like thermogenerators, inductive generators or solar cells. The presented dc-dc converter is characterized by a high efficiency, up to 70 % in the input voltage range between 200 mV and 500 mV, and a minimum start-up voltage of 70 mV. It can deliver an output power of ...

The importance of Cepheids is well known in many fields of astronomy. In this contribution I would like to show how it is possible to obtain indications about the internal structure of a Cepheid and how we can test models of this class of variable stars. Section 2 introduces the Fourier decomposition, a tool to describe quantitatively the light curves of pulsating stars. In the past years I hav...

We outline a neo-Meinongian framework labeled as Modal Meinongian Metaphysics (MMM) to account for the ontology and semantics of fictional discourse. Several competing accounts of fictional objects are originated by the fact that our talking of them mirrors incoherent intuitions: mainstream theories of fiction privilege some such intuitions, but are forced to account for others via complicated ...

In the standard electroweak model, with three families, a one-to-one correspondence between certain determinants involving quark mass matrices (m and m' for charge 2/3 and 1 / 3 quarks respectively) and the presence/absence of CP violation is given. In an arbitrary basis for mass matrices, the quantity Imde t 1-ram +, m ' m '+3 appropriately normalized is introduced as a measure of CP violation...

Leaf characters have been successfully utilized to classify Camellia (Theaceae) species; however, leaf characters combined with supervised pattern recognition techniques have not been previously explored. We present results of using leaf morphological and venation characters of 93 species from five sections of genus Camellia to assess the effectiveness of several supervised pattern recognition ...

The hierarchy of salience of the items of the knowledge assumed by the speaker to be shared by him and by the hearer constitutes one aspect of a dynamic account of discourse (Sect. I). It is claimed that a representation of this hierarchy is a good support for discourse analysis (reference assignement, Sect. 2) and for discourse production (pronominallzatlon, definite des-

UNLABELLED Species of Trichocomaceae occur commonly and are important to both industry and medicine. They are associated with food spoilage and mycotoxin production and can occur in the indoor environment, causing health hazards by the formation of β-glucans, mycotoxins and surface proteins. Some species are opportunistic pathogens, while others are exploited in biotechnology for the production...

Aspergillus section Restricti together with sister section Aspergillus (formerly Eurotium) comprises xerophilic species, that are able to grow on substrates with low water activity and in extreme environments. We adressed the monophyly of both sections within subgenus Aspergillus and applied a multidisciplinary approach for definition of species boundaries in sect. Restricti. The monophyly of s...