A bridgeless PFC rectifier allows the current to flow through a minimum number of switching devices compared to the conventional PFC rectifier. Accordingly, the converter conduction losses can be significantly reduced and higher efficiency can be obtained, as well as cost savings. The comparative study is done between the bridgeless buck and Cuk converter. Hence the harmonics are reduced to obt...

During the continuous casting process, a nonstationary stress state forms in the metal, which is caused by a non-uniform temperature distribution, phase transitions, and the deformation of the stock in a semi-liquid state. Stresses occur also as a results of ferrostatic pressure and the deflection and straightening of the continuous casting. In addition to these phenomena, intensive processes o...

This paper discusses a systematic method for deriving basic converter configurations that achieve power factor correction (PFC) and voltage regulation. The discussion begins with a general three-port representation of power supplies that provide PFC and voltage regulation. Based on this representation and a power flow consideration, a systematic procedure is derived to generate all possible min...

The primate prefrontal (PFC) and posterior parietal cortices (PPC) have been shown to be cardinal structures in processing abstract absolute magnitudes, such as numerosity or length. The neuronal representation of quantity relations, however, remained largely elusive. Recent functional imaging studies in humans showed that blood flow changes systematically both in the PFC and the PPC as a funct...

Constantly increasing customers demands for the production of high and very high-quality steels, promote the intensive technological development of their production. Since the dominating method of global steel production is continuous casting, the tundish has become very important metallurgical unit. Nowadays, tundish is not only a storage vessel which guaranty the continuous casting of steel, ...

Fundamentally-based computational models are developed to quantify the removal of inclusions by bubbles during the continuous casting of steel. First, the attachment probability of inclusions on a bubble surface is investigated based on fundamental fluid flow simulations, incorporating the turbulent inclusion trajectory and sliding time of each individual inclusion along the bubble surface as a...

Solidification rate of the casting affects greatly on the microstructure, quality as well as the mechanical properties of the casting. In centrifugal castings solidification rate is faster compared to gravity casting but still solidification depends on various process parameters like, die wall temperature, pouring temperature of the molten metal, wall thickness of the die and also rotational sp...

The Selective Laser Sintering Process of thermoplastics (SLS) enables the manufacturing of components with complex shape in a short time period without the manufacturing of a specific mold. However, this manufacturing process is limited by the restricted range of materials. In contrast to this primary shaping process, vacuum casting allows a quick, inexpensive and highly accurate process but it...

Previous studies on the neural correlates of perceptual awareness implicate sensory-specific regions and higher cortical regions such as the prefrontal cortex (PFC) in this process. The specific role of PFC regions is, however, unknown. PFC activity could be bottom-up driven, integrating signals from sensory regions. Alternatively, PFC regions could serve more active top-down processes that hel...