Engineering Commons^™

Krf Excimer Laser-Assisted Combustion-Flame Deposition Of Diamond Films, Y. X. Han, Hao Ling, Yongfeng Lu

Department of Electrical and Computer Engineering: Faculty Publications

Cobalt (Co) composition has detrimental effects on the deposition of diamond films on cemented tungsten carbide (WC-Co) substrates. It decreases adhesion of the deposited films to the substrates and causes a transformation of sp³-bonded diamond to sp²-bonded graphite. In this study, a KrF excimer laser with a wavelength of 248 nm, a pulse width of 23 ns, and a pulse energy range of 84–450 mJ was used in the combustion-flame method to improve the quality of the deposited diamond films. Scanning electron microscopy, energy dispersive x-ray analysis, and Raman spectroscopy of the deposited films showed that …

Optical Emission In Magnetically Confined Laser-Induced Breakdown Spectroscopy, X. K. Shen, Yongfeng Lu, T. Gebre, Hao Ling, Y. X. Han

Department of Electrical and Computer Engineering: Faculty Publications

Magnetically confined laser-induced breakdown spectroscopy was investigated by studying the optical emission from laser-induced plasma plumes expanding across an external transverse magnetic field. KrF excimer laser pulses with a pulse duration of 23 ns and a wavelength of 248 nm were used to produce plasmas from Al, Cu, and Co targets. Various optical emission lines obtained from Al and Cu targets show an obvious enhancement in the intensity of optical emission when a magnetic field of ~0.8 T is applied, while the optical emission lines from Co targets show a decrease in the optical emission intensity. The enhancement factors of …

United States Patent: Sound Generating Apparatus For Use With Gloves And Similar Articles, Jan A. Frohman, James L. Jorgensen

Department of Electrical and Computer Engineering: Faculty Publications

The present invention is directed to a sound generating apparatus, including an article adapted to be worn on a user's hand, and an electronic assembly attached to the article. It further includes structure for generating a sound within the electronic assembly. Still further, it includes an actuator for energizing the electronic assembly to emit the sound.

Catalytical Growth Of Carbon Nanotubes/Fibers From Nanocatalysts Prepared By Laser Pulverization Of Nickel Sulfate, J. Shi, Yongfeng Lu, K. F. Tan, Xinwei Wang

Department of Electrical and Computer Engineering: Faculty Publications

Dispersed nickel sulfate (NiSO₄) microclusters on Si substrates were fragmented by pulsed excimer laser irradiation to serve as catalysts for carbon nanotube/nanofiber (CNT/CNF) growth. At proper fluences, NiSO₄ clusters were pulverized into nanoparticles. The sizes of clusters/nanoparticles were found to be dependent on laser fluence and laser pulse number. By increasing the laser fluence from 100 to 300 mJ/cm², the size of disintegrated particles decreased drastically from several micrometers to several nanometers. It was found that laser-induced disintegration of as-dispersed NiSO₄ clusters was mainly due to physical fragmentation by transient thermal expansion/ contraction. Thermal …

Spectrophotometer, Ellipsometer, Polarmeter And The Like Systems, John A. Woollam, Steven E. Green, Ping He, Blaine D. Johs, Craig M. Herzinger, Galen L. Pfeiffer, Brian D. Guenther, Martin M. Liphardt

Department of Electrical and Computer Engineering: Faculty Publications

Disclosed are improvements in ellipsometer and the like systems capable of operating in the Vacuum-Ultra-Violet (VUV) to Near Infrared (NIR) wavelength range, and methodology of use.

On-Off Frequency-Shift Keying For Wideband Fading Channels, Mustafa Cenk Gursoy, H. Vincent Poor, Sergio Verdu

Department of Electrical and Computer Engineering: Faculty Publications

M-ary on-off frequency-shift keying (OOFSK) is a digital modulation format in which M-ary FSK signaling is overlaid on on/off keying. This paper investigates the potential of this modulation format in the context of wideband fading channels. First, it is assumed that the receiver uses energy detection for the reception of OOFSK signals. Capacity expressions are obtained for the cases in which the receiver has perfect and imperfect fading side information. Power efficiency is investigated when the transmitter is subject to a peak-to-average power ratio (PAR) limitation or a peak power limitation. It is shown that under a PAR limitation, it …

The Transcriptome Of Human Oocytes, Arif Murat Kocabas, Javier Crosby, Pablo J. Ross, Hasan H. Otu, Zeki Beyhan, Handan Can, Wai-Leong Tam, Guilherme J. M. Rosa, Robert G. Halgren, Bing Lim, Emilio Fernandez, Jose Bernardo Cibelli

Department of Electrical and Computer Engineering: Faculty Publications

The identification of genes and deduced pathways from the mature human oocyte can help us better understand oogenesis, folliculogenesis, fertilization, and embryonic development. Human metaphase II oocytes were used within minutes after removal from the ovary, and its transcriptome was compared with a reference sample consisting of a mixture of total RNA from 10 different normal human tissues not including the ovary. RNA amplification was performed by using a unique protocol. Affymetrix Human Genome U133 Plus 2.0 GeneChip arrays were used for hybridizations. Compared with reference samples, there were 5,331 transcripts significantly up-regulated and 7,074 transcripts significantly down-regulated in the …

Human Transcriptome Corresponding To Human Oocytes And Use Of Said Genes Or The Corresponding Polypeptides To Trans-Differentiate Somatic Cells, Jose Bernardo Cibelli, Arif Murat Kocabas, Bing Lim, Hasan H. Otu

Department of Electrical and Computer Engineering: Faculty Publications

The identification of 101 genes upregulated or differentially expressed by mature human oocytes is provided herein. These genes and the corresponding gene products will facilitate a greater understanding of oogenesis, folliculogenesis, fertilization, and embryonic development. In addition these genes and the corresponding gene products can be used to effect dedifferentiation and/or transdifferentiation of desired somatic cells. The resultant dedifferentiated cells and somatic cells derived therefrom can be used in cell therapies such as in the treatment of cancer, autoimmunity, and other diseases wherein specific types of cells such as hematopoietic cells may be depleted because of the underlying disease or …

Energy-Constrained Quality Optimization For Secure Image Transmission In Wireless Sensor Networks, Wei Wang, Dongming Peng, Honggang Wang, Hamid Sharif, Hsiao-Hwa Chen

Department of Electrical and Computer Engineering: Faculty Publications

Resource allocation for multimedia selective encryption and energy efficient transmission has not been fully investigated in literature for wireless sensor networks (WSNs). In this article, we propose a new cross-layer approach to optimize selectively encrypted image transmission quality in WSNs with strict energy constraint. A new selective image encryption approach favorable for unequal error protection (UEP) is proposed, which reduces encryption overhead considerably by controlling the structure of image bitstreams. Also, a novel cross-layer UEP scheme based on cipher-plain-text diversity is studied. In this UEP scheme, resources are unequally and optimally allocated in the encrypted bitstream structure, including data position …

Self-Oscillating Cmos Class D Amplifier Optimized For Low Output Power, Daniel J. White

Open Access Master's Theses (through 2010)

The continual push for smaller size and decreased power consumption has prompted the adoption of class D amplification for speaker and headphone drivers in portable media devices.With proper design, the power efficiency of this amplifier type can exceed any other topology over the whole output range, even at low output levels.

Simple amplifier topologies are not the norm for these integrated circuit (IC) class D amplifiers.This thesis shows that such complexity is not necessary for good performance.A recently presented simple self-oscillating topology is mapped into a standard CMOS technology and fabricated in a 0.5 micron process. The output stage is …