609 research outputs found

    Failure of Sandwich Composite Structure Containing Face-sheet/Core Disbonds – An Experimental Study

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    Honeycomb sandwich specimens containing manufactured circular disbonds were loaded to failure in bending. Particular emphasis was placed on accurately identifying the occurrence of disbond buckling and growth initiation, as these two events are difficult to monitor. The test results are presented and then the methods used to identify disbond buckling and growth initiation are described. The method of identifying disbond buckling was very successful. The method of identifying growth initiation was largely successful but improvements are suggested. Finally, conclusions are presented and recommendations made regarding design and repair considerations. The study was performed to provide data against which predictive models can be validated, filling a large gap in the published literature regarding experimental results for disbonded sandwich structure

    The practical feasibility of using RFID in a metal environment

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    Passive Radio Frequency Identification (RFID) has revolutionized the way in which products are identified. This paper considers the effect of metals on the performance of RFID at ultra high frequency (UHF). The paper establishes read patterns in space, highlighting the interference of RF waves due to three different metals, one ferrous and the other two non ferrous, when placed behind a transponder. The effect of thickness of the metal plate is also examined. Different metals have been found to have different interference effects although there are some similarities in their read patterns related to their material properties. Also experiments have been carried out to identify and establish various methods of improving this performance. Finally, differences between performance-measuring parameters, namely attenuating transmitted power and calculating read rate at a fixed attenuation are established and possible reasons of these observations are presented

    Putative markers for the detection of breast carcinoma cells in blood.

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    The aim of this study was to investigate certain genes for their suitability as molecular markers for detection of breast carcinoma cells using the reverse transcriptase-polymerase chain reaction (RT-PCR). RNA was prepared from MCF-7 breast carcinoma cells and peripheral blood leucocytes of healthy female volunteers. This RNA was screened for mRNA of MUC1, cytokeratin 19 (CK19) and CD44 (exons 8-11) by RT-PCR and the results validated by Southern blots. Variable degrees of expression of MUC1 and CD44 (exons 8-11) were detected in normal peripheral blood, rendering these genes non-specific for epithelial cells and therefore unsuitable for use as markers to detect breast carcinoma cells. Although CK19 mRNA was apparently specific, it was deemed unsuitable for use as a marker of breast cancer cells in light of its limited sensitivity. Furthermore, an attempt at using nested primers to increase sensitivity resulted in CK19 mRNA being detected after two amplification rounds in blood from healthy volunteers

    Why rational argument fails the genetic modification (GM) debate

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    AbstractGenetic modification (GM) of crops provides a methodology for the agricultural improvements needed to deliver global food security. However, public opposition to GM-food is great. The debate has tended to risk communication, but here we show through study of a large nationally representative sample of British adults that public acceptance of GM-food has social, cultural and affective contexts. Regression models showed that metaphysical beliefs about the sanctity of food and an emotional dislike of GM-food were primary negative determinants, while belief in the value of science and favourable evaluation of the benefits-to-risks of GM-food were secondary positive determinants. Although institutional trust, general knowledge of the GM-food debate and belief in the eco-friendliness of GM-food were all associated with acceptance, their influence was minor. While a belief in the sanctity of food had a direct inverse effect on GM acceptance, belief in the value of science was largely mediated through favourable perception of benefits-to-risks. Furthermore, segmentation analysis demonstrated that anxiety about GM-food had social and cultural antecedents, with white men being least anxious and older vegetarian women being most anxious. Rational argument alone about the risks and benefits of GM-food is unlikely to change public perceptions of GM-technology

    Opsoclonus-Myoclonus Presenting With Features of Spasmus Nutans

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66540/2/10.1177_088307389501000117.pd

    Bis(guanidinium) 4,5-dichloro­phthalate monohydrate

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    In the structure of the title hydrated salt, 2CH6N3 +·C8H2Cl2O4 2−·H2O, the planes of the carboxyl­ate groups of the dianion are rotated out of the plane of the benzene ring [dihedral angles = 48.42 (10) and 55.64 (9)°]. A duplex-sheet structure is formed through guanidinium–carboxyl­ate N—H⋯O, guanidinium–water N—H⋯O and water–carboxyl­ate O—H⋯O hydrogen-bonding associations

    4-Methyl­pyridinium 2-carb­oxy-4,5-dichloro­benzoate monohydrate

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    In the structure of the 1:1 proton-transfer compound of 4-methyl­pyridine (γ-picoline) with 4,5-dichloro­phthalic acid, C6H8N+·C8H3Cl2O4 −·H2O, determined at 200 K, the 4,5-dichloro­phthalate anions are bridged by the water mol­ecule through O—H⋯Ocarbox­yl hydrogen bonds, giving zigzag chains which extend along the c-axis direction. The 4-methyl­pyridinium cations are linked to the chains through single N—H⋯Owater hydrogen bonds and occupy the voids within the chains in the one-dimensional structure. The anions have the common ‘planar’ conformation with a short intra­molecular O—H⋯Ocarbox­yl hydrogen bond

    Isopropyl­aminium 2-carb­oxy-4,5-di­chloro­benzoate

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    In the structure of the 1:1 proton-transfer compound of isopropyl­amine with 4,5-dichloro­phthalic acid, C3H10N+·C8H3Cl2O4 −, the three cation H-atom donors associate with three separate carboxyl O-atom anion acceptors, giving conjoint cyclic R 4 4(12), R 4 4(16) hydrogen-bonding cation–anion inter­actions in a one-dimensional ribbon structure. In the anions, the carboxyl groups lie slightly out of the plane of the benzene ring [maximum deviations = 0.439 (1) for a carboxylic acid O atom and 0.433 (1) Å for a carboxyl­ate O atom]. However, the syn-related proton of the carboxylic acid group forms the common short intra­molecular O—H⋯Ocarbox­yl hydrogen bond
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