Thomas Leong

Bio: Thomas Leong is an academic researcher from University of Melbourne. The author has contributed to research in topics: Skimmed milk & Whey protein. The author has an hindex of 22, co-authored 48 publications receiving 1749 citations. Previous affiliations of Thomas Leong include Commonwealth Scientific and Industrial Research Organisation & Swinburne University of Technology.

The fundamentals of power ultrasound - a review

Abstract: INTRODUCTION Power ultrasound refers to the section of the sound spectrum from 20 kHz through to around 1MHz. The basis of many applications of ultrasound in this frequency range is acoustic cavitation, which is the formation, growth and collapse of microbubbles within an aqueous solution [1] resultant from pressure fl uctuations that occur in the applied sound fi eld. The event of a collapsing bubble is a microscopic implosion that generates high local turbulence and the release of heat energy. The consequence is a signifi cant increase of temperature and pressure of up to several thousand degrees Kelvin and several hundred Bar. These physical phenomena are the same as those reported in hydrodynamic cavitation which results in damage of mechanical items such as pumps and propellers [2]. These effects can be exploited in a vast array of benefi cial applications [3]. Elevated temperatures [4] in the vicinity of collapsing bubble “hot spots” can be utilised to enhance the chemical reaction rates of some processes, due to the increased heat and the formation of free radicals. Strong disturbances of pressure resultant from shockwave emissions lead to mechanical effects such as mixing and shearing which, for a chemical reaction, can serve to increase encounters between reactants, accelerate dissolution or aid the renewal at the surface of a solid reactant. These conditions, generated by the collapse of bubbles, are the basis for most aspects of sonoprocessing and sonochemistry. Examples of signifi cant applications of acoustic cavitation developed for commercial use include wastewater treatment [5], food and beverages processing [6], and the formation of protein microbubbles which can be used for image contrast agents [7] or drug delivery vehicles [8]. The current review briefl y covers the main concepts which are vital to the understanding of the cavitation phenomena followed by an overview of some of the current applications of ultrasound induced cavitation and some thoughts on what will be in store for the future. On the subject of acoustic cavitation, Neppiras [9] has written an excellent review that covers the important physics of cavitation in sound fi elds. Other invaluable sources of information can be found in the books by Young [1], Brennen [10] and Leighton [11] which detail the mathematical derivations of the basic theories of cavitation and bubble dynamics along with experimental data for these theories. A more recent review by Lauterborn [12] is another excellent reference for those wishing to gain an insight to the fundamental behaviour of bubbles in an acoustic fi eld.

Ultrasonic Separation of Particulate Fluids in Small and Large Scale Systems: A Review

Abstract: This review details recent developments in nondestructive ultrasound separation techniques that can be used to separate, trap, or fractionate particles or emulsified droplets from bulk phase liquids. Whereas most previous reviews have focused on small scales or specific applications, this review groups different aspects of the acoustic separation technique and directs it at an audience with interests in separation technologies. The process has potential as an attractive alternative to common separation processes such as centrifugation, membrane filtration, sedimentation, or fluorescence activated cell sorting (FACS). The technology can achieve precise, gentle, and label-free separation in a system that involves no moving parts. The fundamental concepts are presented in detail and previous studies covering a range of different applications are reviewed. The challenges and opportunities for addressing large-scale industrial applications are evaluated.

Ultrasonic Processing for Dairy Applications: Recent Advances

Abstract: The application of ultrasound to conventional dairy processes has the potential to provide significant benefits for the dairy industry such as energy savings and improved product properties. In recent years, the physical and chemical effects of high-intensity ultrasound in liquid and solid media have been extensively studied. Specific dairy processing applications such as emulsification, crystallisation, inactivation of microbes, functionality modifications and fat separation that harness the physical forces of ultrasound are highlighted in the present review.

Kirk-Othmer Encyclopedia of Chemical Technology数据库介绍及实例

Abstract: 介绍了Kirk—Othmer Encyclopedia of Chemical Technology（化工技术百科全书）（第五版）电子图书网络版数据库，并对该数据库使用方法和检索途径作出了说明，且结合实例简单地介绍了该数据库的检索方法。

PIVlab – Towards User-friendly, Affordable and Accurate Digital Particle Image Velocimetry in MATLAB

Abstract: Digital particle image velocimetry (DPIV) is a non-intrusive analysis technique that is very popular for mapping flows quantitatively. To get accurate results, in particular in complex flow fields, a number of challenges have to be faced and solved: The quality of the flow measurements is affected by computational details such as image pre-conditioning, sub-pixel peak estimators, data validation procedures, interpolation algorithms and smoothing methods. The accuracy of several algorithms was determined and the best performing methods were implemented in a user-friendly open-source tool for performing DPIV flow analysis in Matlab.

Food-grade nanoemulsions: formulation, fabrication, properties, performance, biological fate, and potential toxicity.

Abstract: Nanoemulsions fabricated from food-grade ingredients are being increasingly utilized in the food industry to encapsulate, protect, and deliver lipophilic functional components, such as biologically-active lipids (e.g., ω-3 fatty acids, conjugated linoleic acid) and oil-soluble flavors, vitamins, preservatives, and nutraceuticals. The small size of the particles in nanoemulsions (r<100 nm) means that they have a number of potential advantages over conventional emulsions-higher stability to droplet aggregation and gravitational separation, high optical clarity, ability to modulate product texture, and, increased bioavailability of lipophilic components. On the other hand, there may also be some risks associated with the oral ingestion of nanoemulsions, such as their ability to change the biological fate of bioactive components within the gastrointestinal tract and the potential toxicity of some of the components used in their fabrication. This review article provides an overview of the current status of nanoemulsion formulation, fabrication, properties, applications, biological fate, and potential toxicity with emphasis on systems suitable for utilization within the food and beverage industry.