Effects of Printed Circuit Board Transmission Lines and Loading on Gate Performance

Experimental measurements were conducted on a typical high-speed logic gate (AS04) driving a similar gate(s) as a load(s) and connected via a printed circuit board transmission line. This simple system was used to investigate waveform characteristics. The results show that rise and fall times are a function of position and are linearly dependent on fanout. The gate and line parameters are estimated from these measurements using both lumped and distributed models of the loads.     

The making of the special issue on the application of informationtechnologies to engineering and science education

This paper presents an overview of the special issue of the IEEE Transactions on Education which was an experimental team effort to try and address some of the difficulties in applying information technologies to the creation, review, dissemination, and archiving of multimedia-rich contributions in engineering and science education. The solicitation and review were done electronically using the World Wide Web (WWW) and a restricted access server. The dissemination of the contributions used WWW/CD-ROM technology as a practical means for the IEEE Education Society to electronically distribute and archive the multimedia material containing video, audio, graphics, and code     

Publication of archival journals accompanied by CD-ROMs

This contribution documents some of the ideas, processes and procedures developed for publication of professional journals accompanied by CD-ROM disks during publication of the August 1996 and November 1997 issues of the IEEE Transactions on Education. A fairly detailed account of both the philosophy behind, and the process of, producing the August 1996 issue of the IEEE Transactions on Education was included in that issue in a contribution entitled “The making of the Special Issue on the Application of Information Technologies to Engineering and Science Education”. The present collection of documents neither repeats nor summarizes the content of that document. Instead, it concentrates on the refined processes and procedures implemented during publication of the November 1997 issue     

Aggressive Chemical Mimicry by the Bolas Spider Mastophora hutchinsoni: Identification and Quantification of a Major Prey's Sex Pheromone Components in the Spider's Volatile Emissions

The adult female bolas spider Mastophora hutchinsoni feeds exclusively on attracted males of a few moth species. This exclusivity and the behavior of the approaching moths suggest that the spider aggressively mimics the sex pheromones of its prey species. Males of the bristly cutworm, Lacinipolia renigera, are a major prey of this spider, accounting for about two thirds of the biomass of prey consumed. Female bristly cutworms produce a pheromone blend consisting of (Z)-9-tetradecenyl acetate (Z9–14 : Ac) and (Z,E)-9,12-tetradecenyl acetate (ZE-9,12–14 : Ac). To determine if M. hutchinsoni females mimic the sex pheromone components and blend ratio of L. renigera, we collected volatiles from hunting adult female spiders and analyzed them with gas chromatography–electroantennographic detection (GC-EAD) and gas chromatography–mass spectrometry (GC-MS). GC-EAD analysis of volatile collections, using a male bristly cutworm antenna as the detector and two capillary columns of different polarities, revealed the presence of peaks with retention times (R _ts) identical to Z9–14 : Ac and ZE-9,12– 14 : Ac. The mass spectrum of a peak with R _t of Z9–14 : Ac was identical to the mass spectrum of the synthetic equivalent. There was an insufficient quantity of the compound with R _t of ZE-9,12–14 : Ac to get a full spectrum, but selective detection of ions at m/z 61 and 192 at the correct R _t supported the identification. On average, the blend collected from spiders contained 54.8 ± 20.8 (SE) pg/min of Z9–14 : Ac and 2.5 ± 1.7 (SE) pg/min of ZE-9,12–14 : Ac. The latter, on average, comprised 2.6 ± 0.7% of the total, which is similar to the blend ratio emitted by bristly cutworm females. Our results indicate that the adult female M. hutchinsoni produces an allomone blend that mimics not only the composition, but also the blend ratio, of the sex pheromone of a major prey species.     

Mammary transfer of vitamin E in cows treated with vitamin A or linoleic acid

The effect of an intravenous injection of vitamin A alcohol and subcutaneous injections of linoleic acid on the mammary transfer of an intravenous injection of vitamin E acetate was studied with 15 Holstein cows. The cows received either an intravenous injection of 3 g vitamin E acetate (controls), intravenous injections of 3 g vitamin E acetate and 1 million IU vitamin A alcohol, or an intravenous injection of 3 g vitamin E acetate and subcutaneous injections totaling 40 g of linoleic acid. Milk samples were at 12-h intervals, two prior to and six following treatment. The main influence of vitamin A alcohol and linoleic acid on mammary transfer of vitamin E was to delay secretion of vitamin E in milk. However, total secretion of vitamin E was not reduced by injection of either vitamin A alcohol or linoleic acid. Vitamin E injection produced substantial increases in vitamin E in milk, but less than 1% of the dose could be accounted for in the milk.     

Modelling the effects of neutron radiation on the Gummel-Poon parameters for bipolar NPN transistors

Silicon NPN transistor types 2N2484, 2N2222, and ECG47 were exposed to 1 MeV equivalent neutron fluence levels of 1E+12 to 1E+14 cm⁻². The Gummel-Poon static large-signal model parameters were determined before and after irradiation. The results are used to accurately model irradiated transistors operating at all current levels in the forward active region. An analysis is presented on the change in the Gummel-Poon parameters due to neutron irradiation observed in this work which shows that the Ahlport and Anderson models for the damage factor can be derived from our results and are a consistent subset of our findings.     

Identification of sex pheromone ofTetanolita mynesalis (Lepidoptera: Noctuidae), a prey species of bolas spider,Mastophora hutchinsoni

The bolas spider,Mastophora hutchinsoni, attracts adult males of four species of nocturnally active Lepidoptera through aggressive chemical mimicry of those species' sex pheromones. Here we report the identification of the sex pheromone of one prey species, the smoky tetanolita (Tetanolita mynesalis). In sex pheromone gland extracts, only two peaks stimulated an electrophysiological response as measured by a coupled gas chromatography-electroantennographic detection analysis. These two peaks had retention times identical to (3Z,6Z,9Z)-heneicosatriene (3Z,6Z,9Z-21:H) and (3Z,9Z)-cis-6,7-epoxy-heneicosadiene (3Z,9Z-cis-6,7-epoxy-21:H), respectively, and mass spectra identical to these two compounds. It was determined that 0.23±0.16 and 0.56±0.26 ng of 3Z,6Z,9Z-21:H and 3Z,9Z-cis-6,7-epoxy-21:H, respectively, were present in pheromone gland extracts from individual females. A 1:1 blend of 3Z,6Z,9Z-21:H and 3Z,9Z-6S,7R-epoxy-21:H was an effective attractant for adult males from feral populations. Blend ratios of these two components from 2:1 to 1:2 were equally effective as attractants. Greater deviation from the optimal blends resulted in diminished trap catches. The enantiomer 3Z,9Z-6R,7S-epoxy-21:H not only was not effective in attracting males, its presence in the effective blend shut down trap catches. These results indicate that the pheromone blend consists of 3Z,6Z,9Z-21:H and 3Z,9Z-6S,7R-epoxy-21:H. This is the first report of a hydrocarbon/epoxide pheromone for a prey species of this bolas spider. Sex attractants or pheromones for the other three prey species are composed of aldehydes or acetates.     

The integration of ABET and CSAB

On November 3, 2001, the Accreditation Board for Engineering and Technology (ABET) and the Computing Sciences Accreditation Board (CSAB), two US-based accreditation agencies, were officially integrated into a single agency. This action is the result of many dedicated professionals' engaged in many hours of work and discussions over a period of eight years. It has happened because these professionals and the two organizations share the fundamental belief that students, faculty, educational institutions, the professions, industry, and the global community will be better served by a single organization having accreditation responsibility for educational programs in engineering, technology, computing, and applied sciences. This article discusses the historical background of engineering accreditation and the activities leading to the proposal for the integration of ABET and CSAB. The integration transition period from 1998-2001 is discussed and future directions outlined     

Charge loss in metal-nitride-oxide-semiconductor (MNOS) devices at high temperatures

The charge loss from the nitride layer of MNOS transistors has been studied with emphasis on the temperature effects in the range from 25 to 175°C. The trend of major interest is the increase in the logarithmic decay rate of the dominant negative threshold voltage with increasing temperature. This result is believed due to a combination of three temperature related mechanisms: (1) thermal excitation (TE) discharge, (2) Poole-Frenkel emission-drift-capture events and (3) increasing nitride conductivity with increasing temperature.     

Crosstalk in multilayer printed circuit boards

Experimental measurements were conducted to study the problem of crosstalk in multilayer printed-circuit-board design. Experiments using both pulse and sinusoidal signals were designed to study crosstalk as a function of coupling line lengths, line spacings, and shielding versus nonshielding (lines in different layers). The mutual inductance and capacitance between two similar transmission lines were also extracted from simple models of crosstalk. It is found that when a sinusoid-driven signal was used as the voltage source, the coupled transmission lines acted as a transformer. The induced voltage on the passive line is approximately proportional to the square root of the coupling line length in the range of 2-20 in. These experiments can be used to enhance students' quantitative understanding of the problem of crosstalk in modern electronic circuit design