67 research outputs found

    Efficient Design and Analysis of Lightweight Reinforced Core Sandwich and PRSEUS Structures

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    Design, analysis, and sizing methods for two novel structural panel concepts have been developed and incorporated into the HyperSizer Structural Sizing Software. Reinforced Core Sandwich (RCS) panels consist of a foam core with reinforcing composite webs connecting composite facesheets. Boeing s Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS) panels use a pultruded unidirectional composite rod to provide axial stiffness along with integrated transverse frames and stitching. Both of these structural concepts are ovencured and have shown great promise applications in lightweight structures, but have suffered from the lack of efficient sizing capabilities similar to those that exist for honeycomb sandwich, foam sandwich, hat stiffened, and other, more traditional concepts. Now, with accurate design methods for RCS and PRSEUS panels available in HyperSizer, these concepts can be traded and used in designs as is done with the more traditional structural concepts. The methods developed to enable sizing of RCS and PRSEUS are outlined, as are results showing the validity and utility of the methods. Applications include several large NASA heavy lift launch vehicle structures

    International Veterinary Epilepsy Task Force consensus proposal: Medical treatment of canine epilepsy in Europe

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    In Europe, the number of antiepileptic drugs (AEDs) licensed for dogs has grown considerably over the last years. Nevertheless, the same questions remain, which include, 1) when to start treatment, 2) which drug is best used initially, 3) which adjunctive AED can be advised if treatment with the initial drug is unsatisfactory, and 4) when treatment changes should be considered. In this consensus proposal, an overview is given on the aim of AED treatment, when to start long-term treatment in canine epilepsy and which veterinary AEDs are currently in use for dogs. The consensus proposal for drug treatment protocols, 1) is based on current published evidence-based literature, 2) considers the current legal framework of the cascade regulation for the prescription of veterinary drugs in Europe, and 3) reflects the authors’ experience. With this paper it is aimed to provide a consensus for the management of canine idiopathic epilepsy. Furthermore, for the management of structural epilepsy AEDs are inevitable in addition to treating the underlying cause, if possible

    Polyamines and cancer: old molecules, new understanding

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    The amino-acid-derived polyamines have long been associated with cell growth and cancer, and specific oncogenes and tumour-suppressor genes regulate polyamine metabolism. Inhibition of polyamine synthesis has proven to be generally ineffective as an anticancer strategy in clinical trials, but it is a potent cancer chemoprevention strategy in preclinical studies. Clinical trials, with well-defined goals, are now underway to evaluate the chemopreventive efficacy of inhibitors of polyamine synthesis in a range of tissues

    Like a poet's dreams: the redisplay of the 6th Duke of Devonshire's sculpture gallery at Chatsworth

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    Filming of Pride & Prejudice at Chatsworth in 2004 revealed the original ‘glow of beauty’ of the 6th Duke of Devonshire’s sculpture gallery. This has helped prompt the return of the gallery to its appearance in the mid-19th century, as Charles Noble and Alison Yarrington explain

    The Lustrous Trade. Material Culture and the History of Sculpture in England and Italy c. 1700-c. 1860

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    saggi sulla produzione, il mercato e il collezionismo di scultura tra Italia e Inghilterra nel secolo XVII

    Introduction

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    Aromatic Cyclodehydration. LI. 1

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    Aromatic Cyclodehydration. L. Some Bisacridizinium Systems 1

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    Catalyst and process development for hydrogen preparation from future fuel cell feedstocks. Quarterly progress report, October 1, 1979-December 31, 1979. [Pt/Rh, Ni/Rh, Ni/Pt/Rh, Ni, Ni/Ru, Ni/Pt, Ni/Co]

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    Twelve steam reforming catalysts were evaluated using an autothermal reforming screening unit. Duplicate tests were run with two samples to determine test variability. The samples tested contained either base metals, precious metals, or combinations of base and precious metals. The test was capable of distinguishing among samples where gross variations in composition are the main factor; for example, catalysts containing 2% by weight precious metals are more active than catalysts containing 15% by weight nickel. The results show a decrease in hydrocarbon breakthrough as the weight of nickel charged to the constant volume reactor increases. A commercial nickel catalyst, G90C, appears slightly better than some Engelhard prepared samples of equal nickel concentrations due to the higher density of G90C. Visual observation of the used catalysts show that samples containing only precious metals (Pt/Rh) did not coke during the run. The samples containing only base metals (nickel, cobalt) were coked and were magnetic. Samples containing 14.5% nickel by weight with 0.5% precious metals by weight added were not coked, were not magnetic, and had a blue colored core as compared to the black core of the virgin samples. Some speculation about deactivation mechanisms based on these observations are made

    Catalyst and process development for the H/sub 2/ preparation from future fuel cell feedstocks. Quarterly progress report, October 1, 1978-December 31, 1978

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    The work done under this contract in the last quarter of 1978 was concerned with Phase I, which involved preliminary catalyst and process evaluation. The processes under study are hydrogen assisted steam reforming (HASR), catalytic partial oxidation (CPO), and autothermal steam reforming (ATR). Existing Engelhard test units were modified to carry out preliminary runs using the first two processes. Technical analysis to support work in this area consisted of heat and material balances constrained by equilibrium considerations. In a third task, the steam reforming of methanol to produce hydrogen was studied over two commercial low-temperature shift catalysts. Aging runs indicated good initial performance on both catalysts, but methanol conversion started to decline after a few hundred hours on stream
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