514 resultados para 1353


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Semi-solid forming processes such as thermoforming and injection blow moulding are used to make much of today’s packaging. As for most packaging there is a drive to reduce product weight and improve properties such as barrier performance. Polymer nanocomposites offer the possibility of increased modulus
(and hence potential product light weighting) as well as improved barrier properties and are the subject of much research attention. In this particular study, polypropylene–clay nanocomposite sheets produced via biaxial deformation are investigated and the structure of the nanocomposites is quantitatively determined in order to gain a better understanding of the influence of the composite structure on mechanical properties. Compression moulded sheets of polypropylene and polypropylene/Cloisite 15A nanocomposite (5 wt.%) were biaxially stretched to different stretching ratios, and then the structure of
the nanocomposite was examined using XRD and TEM techniques. Different stretching ratios produced different degrees of exfoliation and orientation of the clay tactoids. The sheet properties were then investigated using DSC, DMTA, and tensile tests .It was found that regardless of the degree of exfoliation or
orientation, the addition of clay has no effect on percentage crystallinity or melting temperature, but it has an effect on the crystallization temperature and on the crystal size distribution. DMTA and tensile tests show that both the degree of exfoliation and the degree of orientation positively correlate with the dynamic mechanical properties and the tensile properties of the sheet.

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This paper argues that religious associations have a number of substantive rights when it comes to their external relations. It does so though comparing the position of the OSCE and the Council of Europe. This paper considers whether the emerging framework includes: (1) a right to legal entity status, (2) a right to establish and run charitable or educational institutions, (3) a right to privileges and substantive benefits and (4) a right to anything else. It concludes that the current developments are welcome because religious freedom has a collective aspect that is essential to the lives of many believers.

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Haigh, David; Birrell, Helen C.; Cantello, Barrie C. C.; Eggleston, Drake S.; Haltiwanger, R. Curtis; Hindley, Richard M.; Ramaswamy, Anantha; Stevens, Nicola C. Department of Medicinal Chemistry, SmithKline Beecham Pharmaceuticals, Essex, UK. Tetrahedron: Asymmetry (1999), 10(7), 1353-1367. Publisher: Elsevier Science Ltd., CODEN: TASYE3 ISSN: 0957-4166. Journal written in English. CAN 131:144537 AN 1999:369514 CAPLUS (Copyright (C) 2009 ACS on SciFinder (R)) Abstract Boron-mediated asym. aldol reactions of 4-[2-(2-benzoxazolylmethylamino)ethoxy]benzaldehyde with 2-oxyethanoyloxazolidinones contg. electron withdrawing, chelating, and bulky alkoxy and aryloxy groups, gave variable yields of syn-aldol adducts in high diastereoisomeric excess. These adducts were dehydroxylated in a sequence which complements the traditional Evans asym. alkylation strategy. Cleavage of the auxiliary from these intermediates afforded antihyperglycemic (S)-(-)-2-oxy-3-arylpropanoic acids in excellent enantiomeric excess. The target compds. were ?-alkoxy-4-[2-[(benzoxazolyl)amino]ethoxy]benzenepropanoic acid derivs. The biol. activity of the compds. thus prepd. was not reported here.

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This article examines two metatheatrical plays written by playwrights from the north of Ireland that bookend the twentieth century. The first is Ulster Literary Theatre (ULT) playwright Gerald MacNamara’s parodic, “proto-Pirandellian”4 The Mist That Does Be on the Bog (1909), which satirizes the peasant aesthetic of the “Abbey play” of the Irish Revival.5 The second is Marie Jones’s international hit, Stones in His Pockets (1999), a “play-full,” postmodern deconstruction of the commodification of Irish culture in the era of the Celtic Tiger. Although separated by exactly ninety years, the two plays can be connected through their critiques of the cultural politics of nationalism and globalization during the periods of the Irish Revival and the Celtic Tiger, respectively. Moreover, both plays are distinguished by their dramaturgical form, as the political critique of each is corporeally embodied in metatheatrical performance.

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Two recent studies of 9/11 literature are dismissive of the contributions that crime and espionage novels have made to ongoing efforts to map the significance of 9/11 and its aftermath. My essay contests the assumption that only literary fiction – which pays sufficient attention to trauma – can “bear witness” to the events of 9/11 and argues that such fiction is, in fact, singularly ill-equipped to illuminate the complex geo-political circumstances that 9/11 entrenched and transformed. By contrast, genre novels by John Le Carré and Don Winslow have responded in imaginative and critical ways to post-9/11 and avowedly trans-national securitization initiatives and hence to efforts to trouble traditional accounts of state sovereignty.

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This Letter describes the hit-to-lead progression and SAR of a series of biphenyl acetylene compounds derived from an HTS screening campaign targeting the mGlu(5) receptor. 'Molecular switches' were identified that modulated modes of pharmacology, and several compounds within this series were shown to be efficacious in reversal of amphetamine induced hyperlocomotion in rats after ip dosing, a preclinical model that shows similar positive effects with known antipsychotic agents. Published by Elsevier Ltd.

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A self-tracking (aligning) radio communications system based on the principle of modulated backscatter detection is presented here. Using amplitude-modulated backscatter from a co-operating target, a modified IQ demodulation scheme is used to reproduce automatically and in real time both the received and conjugate of the received phase of an incoming signal. The phase conjugated demodulated IF signal can have incoming backscattered data removed and new data are inserted before being up-converted using IQ single side-band generation so that retro-directive re-transmission can be made to occur. In the absence of the backscattered modulation signal, no phase conjugation and hence no retro-directed re-transmission can occur. The system reported is therefore inherently self-authenticating a facility not readily available from previously reported retro-directive self-tracking systems. © 2010 © The Institution of Engineering and Technology.

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The Premio Cervantes, one of the most prestigious prizes awarded for literature in the Spanish language, was established in 1976 as Spain negotiated the Transition to democracy in the post-Franco era. This article examines the context in which the prize was created and subsequently used to negotiate inter-continental relations between Spain and Latin America. The article highlights the exchanges of economic, political and symbolic capital which took place between the Spanish State, its representative, the King of Spain, and winning Latin American authors. Significantly, the involvement of the Spanish State is shown to bring political capital into play in a way that commercial prizes do not. In so doing, the Premio Cervantes gives those formerly at the colonial periphery the opportunity to speak out and negotiate the terms of a new kind of relationship with the former colonial center.

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The resonance Raman spectra of a water-soluble metalloporphyrin Cu(TMpy-P4), complexed with a synthetic nucleic acid, poly(dA-dT), were measured by using excitation wavelengths located within the B (Soret) transition of the porphyrin (417-470 nm), while its excited state was synchronously pumped with 545-nm pulsed excitation corresponding to the Q transition. In the presence of pump pulses, the aqueous solution of the Cu(TMpy-P4).poly(dA-dT) complex exhibits resonance Raman bands at 1558 and 1353 cm-1 that are not observed in the absence of pump pulses. These new features were previously assigned to electronically excited Cu(TMpy-P4), stabilized by forming an exciplex with the A-T sites of the nucleic acid. Here we present resonance Raman excitation profiles (RREP) of both the excited and ground states of the complex, and we experimentally confirm the very short lifetime of the exciplex. To our knowledge this is the first time that a RREP of a very short lived (ca. 20 ps) intermediate excited state has been obtained with a two-color experiment. We use this to help to characterize the nature of the porphyrin-AT specific complex formed in the porphyrin excited state.

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The role of climatic change in determining the shape of human evolution,
a theme that came to prominence during the early years of the twentieth
century, has resurfaced with renewed vigor. The author examines the rise and
resurgence of the modern history of the idea that hominid evolutionary pathways
have been triggered by climatic causes to illustrate the continuing vitality of environmental determinism and to highlight some continuities between early-twentieth century and contemporary archaeoanthropology.