--There are several approaches to nonisolated dc-dc conversion for use when the input varies above and below the output. Among these are the SEPIC, buck-boost and others involving a combination of buck and boost circuits. This paper contains an analysis of four types, with particular attention to the efficiency in a typical application.

In many countries, goat farming is the important part from the economy point of the view; especially in the Mediterranean and Middle East region. Goat farming is well organized in France, Italy, Spain and Greece (Park and Haenlein, 2006). Industrialization of the goat milk is not well successed because of its poor and insufficient volume. From 1990, interest in the goat milk production is incre...

Chaotic behaviors of the buck converter were demonstrated by computer simulation studies. The paper implied theoretical considerations and simulations for this kind of converter using a sliding-mode control. The method tried to establish a periodic behavior from a chaotic one in converter behavior. Key-Words: buck converter, sliding-mode, control, bifurcation, periodic, chaotic

The feasibility of using frozen-thawed semen in caprine IVF outside the breeding season was investigated. Electroejaculated spermatozoa from a Nubian buck were washed twice and then frozen in skim milk- or in egg yolk-based extenders. Goat oocytes were matured and inseminated by frozen-thawed spermatozoa selected by swim-up. In vitro fertilization was performed in a modified defined medium (mDM...

An artificial insemination (AI) program using cooled semen was evaluated over a 7-year period in Florida goats. The effect of the following variables on pregnancy rates was analysed: production system, year and season of AI, synchronisation treatment, bucks, AI technicians, semen deposition site, days in milk at AI, milk yield and parity. Animals were reared under field conditions on commercial...

In this paper fractional order averaged model for DC/DC Buck converter in continues condition mode (CCM) operation is established. DC/DC Buck converter is one of the main components in the wind turbine system which is used in this research. Due to some practical restriction there weren’t exist input voltage and duty cycle of converter therefor whole of the wind system was simulated in Matlab/Si...

Non-infectious infertility is particularly critical for sire rams/bucks, as seasonal breeders. This heavy use of males may lead to sexual exhaustion such that the regular semen production, libido, ejaculation, and litter yield can be seriously impaired. In severe cases, reproductive processes stop completely. For avoiding risk, management feeding should firstly arranged with a flock-based appro...

KŘIVÁNEK, I.: Impedance pattern of vaginal and vestibular mucosa in cyclic goats. Acta univ. agric. et silvic. Mendel. Brun., 2008, LVI, No. 4, pp. 109–114 The changes of vaginal and vestibular impedance during the oestrous cycle in goats were examined. The onset of oestrus was teased with a buck once a day during the experiment. Impedance was measured by a four-terminal method. The vaginal imp...

Contagious agalactia (CA) is a highly infectious disease of goats and sheep, and is a form of Mycoplasmosis,which is usually enzootic. Since Mycoplasma agalactiae (M. agalactiae) is the main cause of this disease ingoats, the aim of this study was to isolate and detect M. agalactiae from semen of goat bucks. Thirty-nine semensamples were collected from goat bulks, and all samples were cultured ...

In this study, a modified design of two-switch buck-boost (TSBB) converter is proposed to improve power efficiency using fewer conduction components, and the optimal range measured. The TSBB operates in three topologies: buck, boost, buck-boost, like conventional converter. However, improves buck topologies by decreasing loss diode switch-off section while maintaining same number semiconductors...