Biomedical subjects

G Rodríguez-Corral

Publications and source records attributed to G Rodríguez-Corral.

3 recordsLinked to original sources

PubMed2006

A procedure for the efficient selection of piezoelectric ceramics constituting high-power ultrasonic transducers.

The most characteristic narrow-band transducer structure for high-power ultrasonic applications is the well known piezoelectric sandwich which is reminiscent of the Langevin transducer. Such structure is generally used jointly with other components in the construction of industrial high-power transducers. One of the main objectives in the design and construction of such high-power transducers is to minimize energy losses. To that purpose the selection of the piezoelectric ceramic rings forming the sandwich requires clear and specific criteria. This paper deals with a numerical and experimental procedure for the accurate selection of the piezoelectric rings constituting high-power transducers, based on the analysis of the mechanical Q, the frequency and the resonance curve. The procedure was experimentally checked by constructing and characterizing several transducer structures.

Journal Article↗

PubMed2003

A power ultrasonic technology for deliquoring.

Solid-liquid separation is a topic of permanent interest in many areas such as mineral recovery, food processing and sewage disposal. The adequate application of high-intensity ultrasonic fields may contribute to improve the efficiency of conventional deliquoring processes. Deliquoring refers to removal of liquid from a product without changing its phase. Different effects are involved in the application of high-intensity ultrasound for deliquoring, the most important of which are: the alternating acoustic stresses, the radiation pressure, the acoustic streaming, interface instabilities and cavitation. One of the main advantages of the ultrasonic energy in deliquoring processes is its ability to release the strongly bound moisture. This paper deals with the application of an ultrasonic procedure for deliquoring of slurries in which a high-intensity vibration, homogeneously distributed, is directly applied to the wet particulate material. The vibration travels through the solid-liquid medium and the rapid series of alternative compressions and rarefactions produce a kind of "sponge effect" which favours the migration of moisture through natural or acoustically created channels. The obtained results show that the new technique is very promising to assist filtration processes for solid-liquid separation of highly concentrated suspensions of fine particles.

Filtration↗

PubMed2002

Recent developments in vibrating-plate macrosonic transducers.

As is known, the stepped-plate transducer [Ultrasonics 16 (6) (1978) 267] represents an optimum system for the efficient generation of high-intensity sonic and ultrasonic radiation in fluid media. Nevertheless, the design of this transducer may be difficult to adapt to some specific problems. Such is the case of the treatment of large volumes in industrial installations. A solution is the enlargement of the surface of the radiating plate. However, that means to work at high-order vibration modes which implies numerous practical problems. Another case is the application of the stepped-plate transducer for the generation at sonic frequencies where the height of the steps of the radiating plate, which has to be half a wavelength of the radiation, becomes too high and it makes the transducer construction impractical. To face these specific situations a series of new designs in transducer development have been recently carried out. This paper presents the characteristics of two new transducer devices, one for the treatment of large industrial volumes and the other for low-frequency sonic applications. Both devices are based on vibrating-plate radiators and represent a novel approach to practical existing problems.

Journal Article↗