1,749 research outputs found
Oscillatory fracture path in thin elastic sheet
We report a novel mode of oscillatory crack propagation when a cutting tip is
driven through a thin brittle polymer film. The phenomenon is so robust that it
can easily be reproduced at hand (using CD packaging material for example).
Careful experiments show that the amplitude and wavelength of the oscillatory
crack path scale lineraly with the width of the cutting tip over a wide range
of lenghtscales but are independant of the width of thje sheet and the cutting
speed. A simple geometric model is presented, which provides a simple but
thorough interpretation of the oscillations.Comment: 6 pages, submitted to Comptes Rendus Academie des Sciences. Movies
available at http://www.lmm.jussieu.fr/platefractur
Energy Conversion Alternatives Study (ECAS), Westinghouse phase 1. Volume 7: Metal vapor Rankine topping-steam bottoming cycles
Adding a metal vapor Rankine topper to a steam cycle was studied as a way to increase the mean temperature at which heat is added to the cycle to raise the efficiency of an electric power plant. Potassium and cesium topping fluids were considered. Pressurized fluidized bed or pressurized (with an integrated low-Btu gasifier) boilers were assumed. Included in the cycles was a pressurizing gas turbine with its associated recuperator, and a gas economizer and feedwater heater. One of the ternary systems studied shows plant efficiency of 42.3% with a plant capitalization of $66.7/kW and a cost of electricity of 8.19 mills/MJ (29.5 mills/kWh)
Imiglucerase in the treatment of Gaucher disease: a history and perspective
The scientific and therapeutic development of imiglucerase (Cerezyme®) by the Genzyme Corporation is a paradigm case for a critical examination of current trends in biotechnology. In this article the authors argue that contemporary interest in treatments for rare diseases by major pharmaceutical companies stems in large part from an exception among rarities: the astonishing commercial success of Cerezyme. The fortunes of the Genzyme Corporation, latterly acquired by global giant Sanofi SA, were founded on the evolution of a blockbuster therapy for a single but, as it turns out, propitious ultra-orphan disorder: Gaucher disease
The strong influence of substrate conductivity on droplet evaporation
We report the results of physical experiments that demonstrate the strong influence of the thermal conductivity of the substrate on the evaporation of a pinned droplet. We show that this behaviour can be captured by a mathematical model including the variation of the saturation concentration with temperature, and hence coupling the problems for the vapour concentration in the atmosphere and the temperature in the liquid and the substrate. Furthermore, we show that including two ad hoc improvements to the model, namely a Newton's law of cooling on the unwetted surface of the substrate and the buoyancy of water vapour in the atmosphere, give excellent quantitative agreement for all of the combinations of liquid and substrate considered
Adhesion Improvement of Thermoplastics-Based Composites by Atmospheric Plasma and UV Treatments
The present work is concerned with adhesive bonding of thermoplastic composites used in general aerospace applications, including polyphenylene sulfide (PPS), polyetherimide (PEI) and polyetheretherketone (PEEK) carbon fibre composites. Three different surface treatments have been applied to the PEEK, PPS and PEI-based composites in order to enhance the adhesion: atmospheric plasma, ultraviolet radiation (UV) and isopropanol wiping as a control. Water contact angles and free surface energies were measured following the standard experimental procedure based on the employment of three different liquid droplets. Infrared spectroscopy and X-ray photoelectron spectroscopy (XPS) were subsequently performed to characterize the surface chemistry of the samples after treatment. The single lap joints were manufactured and bonded by an Aerospace grade epoxy-based film adhesive originally developed for use on metals but with the ability to bond treated thermoplastics to good strength (supplied by Henkel Ireland). Quasi-static (QS) tests were conducted. The lap shear strength was evaluated, and the failure mechanisms of the different joints were examined for the range of surface treatments considered. It was found that the performances of the PEEK and PPS joints were considerably improved by the plasma and UV treatments resulting in cohesive and delamination failures, while PEI was unaffected by the plasma and UV treatments and performed very well throughout
Long‐Term Responses Of The Kuparuk River Ecosystem To Phosphorus Fertilization
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/117218/1/ecy2004854939.pd
A Case of IgE Myeloma: Methodology and Review of the Literature
A 56-year-old man presented with a one-year history of progressive weakness predominantly affecting his extremities and persistent low back pain. Ouchterlony immunodiffusion of the concentrated urine detected a marked increase in lambda light chains. A sternal bone marrow documented a diagnosis of multiple myeloma. Screening high resolution agarose gel electrophoresis revealed diffuse hypogammaglobulinemia and, retrospectively, an equivocal, faint band which migrated in the fast gamma region. By using a combination of Immunoelectrophoresis and immunofixation electrophoresis, this questionable band was determined to represent an IgE lambda monoclonal protein. Radioimmunoassay for IgE documented a serum concentration of 50.6 mg/dl. No intact IgE was found in the urine. Following chemotherapy, the patient\u27s serum IgE level decreased significantly, and he is presently asymptomatic. Features of special interest in this case include the low serum IgE level on presentation, which was difficult to detect on the screening electrophoretogram, and the use of immunofixation electrophoresis in the detection and characterization of these difficult gammopathies
Evaporation induced flow inside circular wells
Flow field and height averaged radial velocity inside a droplet evaporating
in an open circular well were calculated for different modes of liquid
evaporation.Comment: 5 page, 3 figures, submitted to European Physical Journal
Proceedings of the 2nd IWDG International Whale Conference. Muc Mhara Ireland's Smallest Whale
Muc Mhara – Ireland’s smallest whale. Proceedings of the 2nd Irish Whale and Dolphin Group International Whale Conference. Papers presented include, “Introduction: The harbour porpoise or Muc Mhara”, “An Irish name for the humble harbour porpoise”, “Life in the Fast Lane: Ecology and Behaviour of harbour porpoises in the Gulf of Maine”, “The ecology of harbour porpoise (Phocoena phocoena) in Irish waters: what strandings programmes tell us.”, “Passive acoustic monitoring of the harbour porpoise (Phocoena phocoena) in Irish waters”, “Abundance estimates of harbour porpoises in Irish waters”, “Satellite tracking of harbour porpoises in European Waters”, “Satellite tracking of harbour porpoises in European Waters”, “A cost of green energy: Are offshore renewables: a threat to porpoises?”, “Harbour porpoise populations and protection in an EU context”, “Assessment of Acoustic Deterrent Devices ‘Pingers’ and porpoise by catch rates in
Irish Gillnet Fisheries in the Celtic Sea” and “Harbour porpoise Conservation in the Republic of Ireland”
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