Generation of monochromatic electrostatic waves of large amplitude in a bounded beam-plasma system

Monochromatic electrostatic waves of large amplitude were excited by the interaction of an electron beam with a bounded plasma. These waves were identified as resonant beam modes, which are amplified by multiple reflexion in a cavity. Nonlinear effects, such as the generation of harmonies and sidebands, were observe

Stability of highly cooled hypervelocity boundary layers

The influence of high levels of wall cooling on the stability of hypervelocity boundary layers is investigated. Such conditions are relevant to experiments in high-enthalpy impulse facilities, where the wall temperature is much smaller than the free-stream temperature, as well as to some real flight scenarios. Some effects of wall cooling are well known, for instance, the stabilization of the first mode and destabilization of the second mode. In this paper, several new instability phenomena are investigated that arise only for high Mach numbers and high levels of wall cooling. In particular, certain unstable modes can travel supersonically with respect to the free stream, which changes the nature of the dispersion curve and leads to instability over a much wider band of frequencies. The cause of this phenomenon, the range of parameters for which it occurs and its implications for boundary layer stability are examined. Additionally, growth rates are systematically reported for a wide range of conditions relevant to high-enthalpy impulse facilities, and the stability trends in terms of Mach number and wall temperature are mapped out. Thermal non-equilibrium is included in the analysis and its influence on the stability characteristics of flows in impulse facilities is assessed

Early Nineteenth Century Accounting by an Adolescent Merchant

Laurie J. Henry, PhD, CPA, CGFM, is an associate professor of accounting, in the Department of Accounting, College of Business and Public Administration, Old Dominion University, Norfolk, VA 23529-0229. Michael E. Bitter, Ph.D., CPA, is a professor of accounting, in the School of Business Administration, M.E. Rinker, Sr. Institute of Tax and Accountancy, Stetson University, Deland, FL 32723

Accounting Administrator Perceptions of Impediments to Seeking AACSB Accounting Accreditation

As of April, 2012, only 168 U.S. institutions had attained and maintained AACSB accounting accreditation. Our objective was to determine why more U.S. institutions have chosen not to pursue AACSB accounting accreditation by identifying accreditation-related issues that are perceived to reduce an institution’s interest in seeking and/or ability to attain it. Surveys were returned by 103 of the 303 accounting program administrators at U.S. institutions with AACSB business (but not accounting) accreditation. The 86 respondents from units not pursing accounting accreditation neither agreed nor disagreed attainment of accounting accreditation would be valued by their institution’s internal constituencies or would enhance their unit’s reputation. Further, these respondents generally perceive their unit meets AACSB accounting pre-conditions and would have the ability to meet most accounting accreditation standards if they chose to pursue accounting accreditation. The issues of most significance are resource-related – securing the necessary resources to achieve their mission and action items and to meet AACSB standards on faculty sufficiency. Overall, the respondents’ lack of interest in accounting accreditation reportedly has less to do with the inability to meet accreditation standards and more to do with a lack of perceived value in accounting accreditation to warrant commitment of necessary resources

Nuclear Magnetic Resonance and Hyperfine Structure

Contains research objectives and reports on three research projects

Automated operation of a home made torque magnetometer using LabVIEW

In order to simplify and optimize the operation of our home made torque magnetometer we created a new software system. The architecture is based on parallel, independently running instrument handlers communicating with a main control program. All programs are designed as command driven state machines which greatly simplifies their maintenance and expansion. Moreover, as the main program may receive commands not only from the user interface, but also from other parallel running programs, an easy way of automation is achieved. A program working through a text file containing a sequence of commands and sending them to the main program suffices to automatically have the system conduct a complex set of measurements. In this paper we describe the system's architecture and its implementation in LabVIEW.Comment: 6 pages, 7 figures, submitted to Rev. Sci. Inst

Oostenrijk, een voorbeeld voor Nederland

Van 24 tot 28 januari zal de korte reis van B.I.L. plaatsvinden, waarin de stad Wenen wordt bezocht. In de hoofdstad van Oostenrijk werd op 22 november jl. het International Cooperation Forum georganiseerd1 • Oostenrijk, dat bekend staat om zijn architectuur en prachtige bergen waar wintersporters zich over verheugen, heeft namelijk meer te bieden. Het land heeft in 2008 de prijs Best e-Government Identity Management project gewonnen en staat bovenaan in de e-government ranglijst van landen binnen de Europese Unie. Een korte kennismaking met Oostenrijk als held in e-governance

Iron impregnation on the amorphous shell of vapor grown carbon fibers and the catalytic growth of secondary nanofibers

Vapor grown carbon fibers (VGCFs) with diameters of several microns were synthesized and investigated by high resolution transmission electron microscopy. It was found that the shell of the VGCFs consisted of densely-packed domains embedded in loosely-packed matrix, and both were highly amorphous. Regular edge planes as observed on the surface of fishbone nanofibers do not exist on VGCFs. Hence, surface treatment is more important for the deposition of catalysts. Ammonium ferric citrate (AFC) was employed for the impregnation of iron, where the high viscosity of the aqueous solution of AFC is beneficial. Calcination was found to be a key step to improve the dispersion of the iron particles, which can be attributed to enhanced interactions between iron and carbon due to the gasification of carbon occurring at the iron-carbon interface. Quantitative analysis by X-ray photoelectron spectroscopy showed that the calcination of the supported AFC led to a higher atomic concentration of iron on the surface, indicating smaller particle size and higher dispersion. Secondary carbon nanofibers were grown subsequently on the VGCFs from cyclohexane. The specific surface area was enhanced considerably, from less than 1 m2 g-1 to 106 m2 g-1 after the growth of the secondary nanofibers. The obtained composites are promising materials as structured support in heterogeneous catalysis

Identification of a Chitin-Binding Protein Secreted by Pseudomonas aeruginosa

One of the major proteins secreted by Pseudomonas aeruginosa is a 43-kDa protein, which is cleaved by elastase into smaller fragments, including a 30-kDa and a 23-kDa fragment. The N-terminal 23-kDa fragment was previously suggested as corresponding to a staphylolytic protease and was designated LasD (S. Park and D. R. Galloway, Mol. Microbiol. 16:263-270, 1995). However, the sequence of the gene encoding this 43-kDa protein revealed that the N-terminal half of the protein is homologous to the chitin-binding proteins CHB1 of Streptomyces olivaceoviridis and CBP21 of Serratia marcescens and to the cellulose-binding protein p40 of Streptomyces halstedii. Furthermore, a short C-terminal fragment shows homology to a part of chitinase A of Vibrio harveyi. The full-length 43-kDa protein could bind chitin and was thereby protected against the proteolytic activity of elastase, whereas the degradation products did not bind chitin. The purified 43-kDa chitin-binding protein had no staphylolytic activity, and comparison of the enzymatic activities in the extracellular medium of a wild-type strain and a chitin-binding protein-deficient mutant indicated that the 43-kDa protein supports neither chitinolytic nor staphylolytic activity. We conclude that the 43-kDa protein, which was found to be produced by many clinical isolates of P. aeruginosa, is a chitin-binding protein, and we propose to name it CbpD (chitin-binding protein D)