CAMP Professor Ming-Cheng Cheng has Sabbatical in France
CAMP Professor Ming-Cheng Cheng (of Clarkson’s Department of Electrical and Computer Engineering) recently returned from a sabbatical in France. He spent nearly a year, from August 2006 – July 2007, visiting the Laboratoire de Photonique et de Nanostructures at CNRS in France. During his stay, he worked with an experimental team at CNRS to investigate the effects of the DX impurity levels on electron concentration and electronic characteristics in AlGaAs/GaAs heterojunctions and devices. He was also involved in the modeling of quantum point contacts and ultra-low noise HEMT amplifiers. In addition, Professor Cheng visited several universities, including Ecole Nationale Superieure de Physique de Strasbourg, France; National Cheng-Kun University, Taiwan; National Sun Yat-Sen University, Taiwan; and Southen Taiwan University of Technology, Taiwan, where he gave talks about his work in the areas of spintronic devices, DX centers in AlGaAs/GaAs heterostructures, and the electro-thermal modeling of SOI integrated circuits. He also presented technical papers at the International Conference of Solid- State and Integrated Circuit Technology in Shanghai, China, in October 2006, and at the International Workshop on Low Temperature Detectors in Paris, France, in July 2007.
Figure1. Energy band structure in AlGaAs/GaAs heterostructure where the quai-Fermi level E fn is pinned at the DX level near the d -doped location at z 2. V g and fb are the applied gate voltage and Schottky barrier, respectively.
Drug Tablet Mechanical Property and Thickness Characterization using Air-Coupled Acoustics
Figure 2. Image of the bottom excitation configuration for the drug tablet characterization setup, with a vacuum wand holding the Advil tablet in place.
CAMP Professor Cetin Cetinkaya, Director of the Photo-Acoustics Research Laboratory, describes a method to characterize and monitor drug tablets. Physical (mechanical) properties and mechanical defects (e.g. cracks, capping, and delamination) of drug tablets may affect their therapeutic functions. Details of the non-contact/non-destructive acoustic technique for determining the mechanical properties such as Young’s moduli, Poisson’s ratios and mass densities of the core and the coat materials and coating thickness of tablets with a mono-layer coating layer are available in a recent publication. These properties are critical to the design of tablets and the performance evaluation of the relevant manufacturing processes. The current method is based on the air-coupled excitation of a tablet and the interferometric detection of its vibrational motion. For more information, see the following reference (I. Akseli and C. Cetinkaya, “Drug Tablet Thickness Estimations using Air-Coupled Acoustics,” the International Journal of Pharmaceutics, Vol. 351, No. 1-2, pp. 165-173, 2008).