Digital Signal Processing

Contains an introduction and reports on fifteen research projects.National Science Foundation FellowshipU.S. Navy - Office of Naval Research (Contract N00014-81-K-0742)National Science Foundation (Grant ECS 84-07285)Sanders Associates, Inc.U.S. Air Force - Office of Scientific Research (Contract F19628-85-K-0028)AT&T Bell Laboratories Doctoral Support ProgramCanada, Bell Northern Research ScholarshipCanada, Fonds pour la Formation de Chercheurs et /'Aide a la Recherche Postgraduate FellowshipCanada, Natural Science and Engineering Research Council Postgraduate FellowshipAmoco Foundation FellowshipFannie and John Hertz Foundation Fellowshi

Digital Signal Processing

Contains an introduction and reports on twenty research projects.National Science Foundation (Grant ECS 84-07285)U.S. Navy - Office of Naval Research (Contract N00014-81-K-0742)National Science Foundation FellowshipSanders Associates, Inc.U.S. Air Force - Office of Scientific Research (Contract F19628-85-K-0028)Canada, Bell Northern Research ScholarshipCanada, Fonds pour la Formation de Chercheurs et l'Aide a la Recherche Postgraduate FellowshipCanada, Natural Science and Engineering Research Council Postgraduate FellowshipU.S. Navy - Office of Naval Research (Contract N00014-81-K-0472)Fanny and John Hertz Foundation FellowshipCenter for Advanced Television StudiesAmoco Foundation FellowshipU.S. Air Force - Office of Scientific Research (Contract F19628-85-K-0028

Digital Signal Processing

Contains table of contents for Part III, table of contents for Section 1, an introduction and reports on seventeen research projects.National Science Foundation FellowshipNational Science Foundation (Grant ECS 84-07285)National Science Foundation (Grant MIP 87-14969)U.S. Navy - Office of Naval Research (Contract N00014-81-K-0742)Scholarship from the Federative Republic of BrazilU.S. Air Force - Electronic Systems Division (Contract F19628-85-K-0028)AT&T Bell Laboratories Doctoral Support ProgramCanada, Bell Northern Research ScholarshipCanada, Fonds pour la Formation de Chercheurs et I'Aide a la Recherche Postgraduate FellowshipSanders Associates, Inc.OKI Semiconductor, Inc.Tel Aviv University, Department of Electronic SystemsU.S. Navy - Office of Naval Research (Contract N00014-85-K-0272)Natural Sciences and Engineering Research Council of Canada, Science and Engineering Scholarshi

Feasibility of High Frequency Acoustic Imaging for Inspection of Containments: Phase II

The nuclear power industry is concerned with corrosive thinning of portions of the metallic pressure boundary, particularly in areas that are not directly accessible for inspection. This study investigated the feasibility of detecting these thickness degradations using ultrasonic imaging. A commercial ultrasonic system was used to carry out several full-scale, controlled laboratory experiments. Measurements of 0.5 MHz shear wave levels propagated in 25-mm-thick steel plate embedded in concrete showed 1.4-1.6 dB of signal loss for each centimeter of two-way travel in the steel plate (compared to previous numerical predictions of 3-4 dB), and 1.3 dB of signal loss per centimeter of two-way travel in steel plates embedded in concrete prior to setting of the concrete (i.e., plastic). Negligible losses were measured in plates with a decoupling treatment applied between the steel and concrete to simulate the unbonded portions of the pressure boundary. Scattered signals from straight slots of different size and shape were investigated. The return from a 4-mm-deep rectangular slots exhibited levels 23 dB down relative to incidence and 4-6 dB higher than those obtained from both ''v'' shaped and rounded slots of similar depth. The system displayed an input/output dynamic range of 125 dB and measurement variability less than 1-2dB. Based on these results, a 4-mm-deep, rounded degradation embedded 30 cm in concrete has expected returns of -73dB relative to the input and should therefore be detectable. Results of this and a prior study indicate that the technique has merit and should be developed more fully and demonstrated in the field

Public health hazards in Poland posed by foodstuffs contaminated with E.Coli O104:H4 bacterium from the recent European out break

Shiga toxin producing Escherichia coli (STEC) are the most virulent diarrhoeagenic E. coli known to date. They can spread with alarming ease via the food chain, as recently demonstrated by the large outbreak of STEC O104:H4 borne by sprouted seeds in 2011, clustered in northern Germany, and subsequently affecting other countries. Indeed, a significant number of infections to verocytotoxin producing Escherichia coli O104:H4 have been reported from the WHO European Region resulting in many cases of bloody diarrhoea and haemolytic uraemic syndrome in Germany, 15 other European countries and North America. Eventually, the European Food Standards Agency, (EFSA), identified the likely source to a single consignment of fenugreek seeds from an Egyptian exporter as being linked to the two outbreaks in Germany and France. The situation was closely monitored by the Chief Sanitary Inspectorate public health authority in Poland where actions undertaken ensured that the public was well informed about the dangers of STEC contamination of food, how to avoid infection, and what to do if infected. Tracing the fenugreek distributors also enabled the identification of suspected batches and their isolation. As a result, there were very few reported cases of STEC infection in Poland. Effective control over such outbreaks is therefore a vital public health task. This should include early detection and rapid identification of the contagion mode, followed by removing the foodstuff(s) from the market, providing consumer advice, and preventing secondary spreading. As a mitigation measure, screening/monitoring those involved in food handling is also warranted to exclude carriers who can be asymptomatic