Recent Patents on Engineering - Volume 2, Issue 1, 2008

In general, there are three ways of generating microbubbles. The most common class uses compression of the air stream to dissolve air into liquid, which is subsequently released through a specially designed nozzle system, to nucleate small bubbles as potentially nanobubbles, based on the cavitation principle. These bubbles subsequently grow into much larger bubbles through the rapid dissolution of the supersaturated liquid. The second class uses power ultrasound to induce cavitation locally at points of extreme rarefaction in the standing ultrasonic waves. The third class uses an air stream delivered under low offset pressure, and airs to break off the bubbles due to an additional feature, whether it be mechanical vibration, or flow focussing, or fluidic oscillation. Conventional air diffusers rely on the structure of porous material for the nozzles to generate small bubbles, but fluidic oscillation in general promises to break off the forming bubble while it is still a hemispherical cap - the smallest shape for which bubble formation from a pore is likely to occur given the strong adverse affect of surface tension at higher curvatures. The first two classes of microbubble generation are usually associated with high power densities and power consumption by either the compression or ultrasonic treatment. The third class should have the lowest power consumption, provided it achieves the application targets of bubble size distribution, air phase holdup, and bubble dispersion. In this paper, recent patents in microbubble generation are categorized into the first and the third classes above. The subject area is reviewed for its importance in several fields of application, particularly generalized flotation processes and bioreactor treatments.

Supercritical fluid techniques for materials precipitation have been proposed as an alternative to conventional precipitation processes as they can improve the performance of these processes in terms of reduction of particle size and control of morphology and particle size distribution, without degradation or contamination of the product. These techniques have received much attention during the last years, and their feasibility and performance have been proved for many substances. Several precipitation technologies, in which the supercritical fluid plays different roles (solvent, anti solvent, co solvent, solute, atomization agent…) have been developed. This article presents a review of the patents related to supercritical precipitation technologies, with emphasis on the description of the different precipitation methods and mechanisms exploited by these technologies, and on the technical solutions given for the practical problems of the technologies.

Controlled drug release and drug delivery are always emerged as the area to which medicinal technology is extensively inclined. Thanks to the latest inventions and all the patents in the ambit of drug delivery, powder technology and granular science which provide the pathway to effectively control the diseases in conjunction with the latest available techniques. In this paper, exploration of various latest processes and methods for drug delivery are reviewed and information regarding novel inventions and patents in the field of powder technology and granular science, useful for drug delivery; are presented to the point and all the original inventions appreciated. The hands on information related to the work done for improvement of flow behavior of medicaments, types of apparatus and processes discovered provide good tool for improving the existing facilities for drug delivery.

Compared with suspended microorganism technology, immobilized microorganism technology possesses many advantages, such as high biomass, high metabolic activity, and strong resistance to toxic chemicals, and so on. This review presents the state of the art of various immobilized microorganism methods as well as immobilization microorganism carriers whose engineering applications are mainly focused on bioreactors including fluidized bed reactor (FBR) and packed bed reactor (PBR). This review covers the patents which emphasize the characteristic of the immobilization carriers as well as bioreactors from the year of 2000 up to date. In the last part of the review, the future developing trend in immobilization microorganism technology and the potential engineering applications in wastewater treatment were also proposed tentatively.

A large amount of finite elements have been developed for finite element analysis of laminated composite plates. The laminated plate theories are reviewed and summarized in this paper. The focus of this review is on the recently developed laminated finite elements since 1990. The 2-D triangular and quadrilateral displacement-based and mixed/hybrid-based finite element models, which were developed based on the first-order shear deformation theories, the higher-order shear deformation theories, the zig-zag theories and the global-local higher-order deformation theories, and the layer-wise laminated plate theories are reviewed in this paper and also their related patents. Finally, some points on the development of the laminated finite elements are summarized.

Since recent past the research on biodiesel production and processing has got high momentum as evidenced from the large number of publications and patents on the subject. Many novel and improved protocols based on chemical, physical, and biological approaches have been reported that addresses the critical issues related to biodiesel production, recovery, purification, and associated recovery of high valued secondary products. Biodiesel typically comprises lower alkyl fatty acid (chain length C14-C22) esters of short-chain alcohols, primarily, methanol or ethanol. Various methods, such as pyrolysis, micro-emulsification, ozonization, ultrasonication, and transesterification have been reported for the production of biodiesel from vegetable oil. Among these, transesterification is appeared as attractive and widely accepted technique. This transesterification is mostly done chemically or enzymatically using lipase as biocatalyst. Lipase catalysis has received increasing attention due to its certain advantages over the conventional chemical catalysis. However, poor operational stability and low focus on the application of lipase for the biodiesel production are some of the important obstructing factors that impede the progress of the enzyme-based process. In addition to the transesterification step, separation of the ester from the reaction mixture, purification of the ester and glycerol, maintenances of appropriate fuel quality standards of the biodiesel (or blend stocks) as per specification for the particular nation, storage and stabilization are ascribed as the critical steps having immense effect on the successful implementation of biodiesel production and processing. In this review, the authors emphasise the important patents developed in the last few years that contribute to mitigate the major technological challenges on biodiesel production and processing.

Transmultiplexer is a major component of multicarrier communication system. Traditionally, it was implemented using SSB modulator and analog filters. But due to the limitation of high level of cross talk and interference in analog device, it has been replaced by DFT based transmultiplexer system. DFT based transmultiplexer comprises digital filter bank and multirate devices to provides better reduction in interference and cross talk. However, it provide relatively large overlapping sidelobes (-13dB). An alternative scheme known as cosine modulation where the design of synthesis and analysis part of the transmultiplexer is the cosine modulated filter bank. This paper reviews various recent patents in filter bank, transmultiplexer and its applications.

Full text available