684 research outputs found
1869, Cornell University Press Podcast, Ep. 118 with Jayita Sarkar, author of Ploughshares and Swords
No full textThis episode, we speak with Jayita Sarkar, author of the new paperback and open access ebook Ploughshares and Swords: India’s Nuclear Program in the Global Cold War. Jay Sarkar is Senior Lecturer in Economic and Social History at the University of Glasgow and the Founding Director of the Global Decolonization Initiative.
We spoke to Jay about how the history of India’s first nuclear weapons test in 1974 has been overshadowed by their 1998 nuclear tests, why the conventional wisdom that India started off its nuclear program with nuclear energy first is in fact incorrect, and the strong connections between India’s nuclear program and their space program
An inventory model with reliability in an imperfect production process
No full textThe paper analyzes an economic manufacturing quantity (EMQ) model with price and advertising demand pattern in an imperfect production process under the effect of inflation. If the machine goes through a long-run process, it may shift from in-control state to out-of-control state. As a result, the system produces imperfect items. The imperfect items are reworked at a cost to make it as new. The production of imperfect quality items increases with time. To reduce the production of the imperfect items, the systems have to more reliable and the produced items depend on the reliability of the machinery system. In this direction, the author considers that the development cost, production cost, material cost are dependent on reliability parameter. Considering reliability as a decision variable, the author constructs an integrated profit function which is maximized by control theory. A numerical example along with graphical representation and sensitivity analysis are provided to illustrate the model. �� 2011 Elsevier Inc. All rights reserved
Vers des nanorubans aromatiques : approches par formation de céramidonines et par réaction de Perkin
No full textLes nanorubans de graphène (NRGs) sont des matériaux prometteurs pour l'organique électronique, à mi chemin entre polymères conjugués et nanotubes de carbone. Deux approches différentes pour la synthèse de nanorubans aromatiques sont développées et évaluées. La première est fondée sur la formation de céramidonines par cyclisation d'arylamino-anthraquinones en milieu acide. Plusieurs tétraaza-arènes incorporant deux de ces unités sont obtenus, mais l'approche s'est uniquement avérée appropriée dans le cas de courts substrats. La seconde approche repose sur la condensation d'acides aryle-acétiques avec des formylarènes ou acides aryle-glyoxyliques, suivie soit de cyclo-deshydrogénations en présence de quinone, soit de deshydrodebromation catalysée par le palladium, pour donner des arenes carboxy-substitués allongés. La méthode impliquant la quinone s'avère limitée à des substrats suffisamment réactifs tels que des thiophènes et laisse envisager des poly(arènodithiophènes) en partie rigidifiés et carboxy-substitués. La catalyse au palladium s'avère plus générale, ouvrant des perspectives d'obtention d'une grande variété de rubans aux propriétés électroniques ajustables.Graphene nanoribbons (GNRs) are promising materials for organic electronics, as they bridge the gap betweensingle-stranded conjugated polymers and carbon nanotubes. Two different synthetic approaches to GNRs aredeveloped and evaluated. The first approach is based on the acid-promoted cyclisation of arylaminoanthraquinonesto ceramidonines. Tetraazaarenes with two ceramidonine units are obtained, but the approachis found to be appropriate only to such small systems. The second approach is based on the condensation ofarylacetic acids with arenecarboxaldehydes or arylglyoxylic acids, followed either by quinone-assistedoxidative cyclodehydrogenation or palladium-catalysed dehydrodebromination to yield carboxy-substitutedelongated arenes. The quinone-based variant is found to be limited to reactive substrates such as thiophenederivatives and offers the perspective of partially rigidified carboxy-substituted poly(arenodithiophenes). Thepalladium-based variant is found to be more general, opening the prospect of obtaining a variety of ribbontypestructures with tunable electronic properties
Some multivariate linear regression testing problems with additional observations
No full textAbstractIn an earlier paper, the present author (Sarkar (1979), Calcutta Statist. Assoc. Bull.28, 47–56) proposed a similar test for a mean testing problem with additional observations on a set of correlated auxiliary variables. This idea has been extended here to cover some multivariate linear regression testing problems with the same type of additional observations on a set of correlated auxiliary variables
The ceramidonine and perkin approaches to aromatic nanoribbons
No full textLes nanorubans de graphène (NRGs) sont des matériaux prometteurs pour l'organique électronique, à mi chemin entre polymères conjugués et nanotubes de carbone. Deux approches différentes pour la synthèse de nanorubans aromatiques sont développées et évaluées. La première est fondée sur la formation de céramidonines par cyclisation d'arylamino-anthraquinones en milieu acide. Plusieurs tétraaza-arènes incorporant deux de ces unités sont obtenus, mais l'approche s'est uniquement avérée appropriée dans le cas de courts substrats. La seconde approche repose sur la condensation d'acides aryle-acétiques avec des formylarènes ou acides aryle-glyoxyliques, suivie soit de cyclo-deshydrogénations en présence de quinone, soit de deshydrodebromation catalysée par le palladium, pour donner des arenes carboxy-substitués allongés. La méthode impliquant la quinone s'avère limitée à des substrats suffisamment réactifs tels que des thiophènes et laisse envisager des poly(arènodithiophènes) en partie rigidifiés et carboxy-substitués. La catalyse au palladium s'avère plus générale, ouvrant des perspectives d'obtention d'une grande variété de rubans aux propriétés électroniques ajustables.Graphene nanoribbons (GNRs) are promising materials for organic electronics, as they bridge the gap betweensingle-stranded conjugated polymers and carbon nanotubes. Two different synthetic approaches to GNRs aredeveloped and evaluated. The first approach is based on the acid-promoted cyclisation of arylaminoanthraquinonesto ceramidonines. Tetraazaarenes with two ceramidonine units are obtained, but the approachis found to be appropriate only to such small systems. The second approach is based on the condensation ofarylacetic acids with arenecarboxaldehydes or arylglyoxylic acids, followed either by quinone-assistedoxidative cyclodehydrogenation or palladium-catalysed dehydrodebromination to yield carboxy-substitutedelongated arenes. The quinone-based variant is found to be limited to reactive substrates such as thiophenederivatives and offers the perspective of partially rigidified carboxy-substituted poly(arenodithiophenes). Thepalladium-based variant is found to be more general, opening the prospect of obtaining a variety of ribbontypestructures with tunable electronic properties
Ananda K. Coomaraswamy, Benoy Kumar Sarkar, and the Śukranīti
No full textThe English-raised Ananda K. Coomaraswamy, the twentieth century’s leading historian of Indian art, is well known for prizing tradition and anonymity and for upholding the position that visualization exercises were an essential part of the creative process. The first part of this article addresses the role of the English Arts and Crafts Movement and of such lesser-known figures as Sister Nivedita and Lionel de Fonseka in shaping Coomaraswamy’s views. The middle part consists of a discussion of the passages in the nineteenth-century Sanskrit treatise the Śukranīti that Coomaraswamy depended upon to support his opinions. The final part of the article is devoted to the writings of the sociologist Benoy Kumar Sarkar, author of the standard translation of the Śukranīti. As an opponent of the over-spiritualisation of Indian civilisation, he constructed a universal grammar of art. In this enterprise, he was heavily influenced by the American painter Max Weber
Repensando la ciencia. La reconstrucción de la ciencia y de la sociedad de P. R. Sarkar
No full textFaced with the traditional or positivist science that stands outside history, culture and language, the author presents the thinking of Sarkar, who does not argue for an anti-science, anti-technology or falls into a science that would exist outside the social and political, but one within context, arguing for a new science of society. This paper raises important questions, such as: in what direction will then move social sciences: towards empathy and interpretation or towards disinterest and distance? Are we close to losing the universal perspectives as power and knowledge are localized and relativized? Or we are dealing with a new model of the real close, that becoming dominant will reformulate the categories of "science", "local" and "universal"?Frente a la ciencia tradicional o positivista que se coloca fuera de la historia, de la cultura y del lenguaje, el autor presenta el pensamiento de Sarkar, quien no argumenta por una posición anti-ciencia, anti-tecnología ni cae en una ciencia que existe fuera de lo social y lo político, sino contextualizada, abogando por una nueva ciencia de la sociedad. El trabajo plantea relevantes preguntas como: ¿En qué dirección se moverán luego las ciencias sociales: hacia la empatía e interpretación o hacia el desinterés y distancia? ¿Estamos nosotros cerca de perder los universales ya que el poder y el conocimiento son localizados y relativizados? ¿O es un nuevo modelo de lo real cercano de llegar a ser dominante que reformula estas categorías de "ciencia", "local" y "universal"
Modular synthesis of oligoacetylacetones via site-selective silylation of acetylacetone derivatives
No full textOligoacetylacetones consisting of 3,3-disubstituted pentane-2,4-diones were synthesized through a terminal silylation and oxidative coupling protocol. Highly selective formation of mono-enol silyl ethers of 3,3-disubstituted acetylacetones was achieved using 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) as a base. Subsequent silver(i) oxide mediated coupling reactions provided tetraketones. Unique substituent dependence was found for the terminal-selective silylation of tetraketones. Finally, octaketones (tetramers of acetylacetone derivatives) with three types of monomer sequences were prepared in their discrete forms. Single crystal X-ray analysis revealed that the solid-state conformations of oligoketone chains were predominantly governed by the ketone sequence rather than substituents. However, differences in the packing structures induced by alkyl substituents led to significant differences in melting points for the structural isomers of octaketones
“A legacy of troubles. Bengal Partition as long-lasting narration”
No full textThis essays analyses Indian Partition Literature, focusing on the Eastern border and the novel East/West by the Bengali author Gangopadhyay
Experimental study of thin film sensor networks for wind turbine blade damage detection
No full textDamage detection of wind turbine blades is difficult due to their complex geometry and large size, for which large deployment of sensing systems is typically not economical. A solution is to develop and deploy dedicated sensor networks fabricated from inexpensive materials and electronics. The authors have recently developed a novel skin-type strain gauge for measuring strain over very large surfaces. The skin, a type of large-area electronics, is constituted from a network of soft elastomeric capacitors. The sensing system is analogous to a biological skin, where local strain can be monitored over a global area. In this paper, we propose the utilization of a dense network of soft elastomeric capacitors to detect, localize, and quantify damage on wind turbine blades. We also leverage mature off the shelf technologies, in particular resistive strain gauges, to augment such dense sensor network with high accuracy data at key locations, therefore constituting a hybrid dense sensor network. The proposed hybrid dense sensor network is installed inside a wind turbine blade 1:25 scale model, and tested in a wind tunnel to simulate an operational environment. Results demonstrate the ability of the hybrid dense sensor network to detect, localize, and quantify damage.</p
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