46,394 research outputs found
The application of reliability methods in the design of tophat stiffened composite panels under in-plane loading
No full textComposite materials have been widely used in modern engineering fields such as aircraft, space and marine structures due to their high strength-to-weight and stiffness-to-weight ratios. However, structural efficiency gained through the adoption of composite materials can only be guaranteed by understanding the influence of production upon as-designed performance. In particular, topologies that are challenging to production including panels stiffened with pi or tophat stiffeners dominate many engineering applications and often observe complex loading. The design of stiffened composite panels against buckling is a key point of composite structures. While a growing number of studies are related to the reliability analysis of composites few of these relate to the local analysis of more complicated structures. Furthermore for the assessment of these structures in a design environment it is important to have models that allow the rapid assessment of the reliability of these local structures. This paper explores the use of a stochastic approach to the design of stiffened composite panels for which typical applications can be found in composite ship structures. A parametric study is conducted using Navier grillage theory and First-order Reliability Methods to investigate any detectable trend in the safety index with various design parameters. Finally, recommendations are made to provide guidance on applications
Seminário sobre aquacultura 14 a 16 de dezembro de 1983
No full textA necessidade de desenvolver a aquacultura em Portugal obriga à escolha das espécies mais indicadas para tal finalidade. A propósito o autor chama a atenção para as graves consequências que podem advir das introduções e/ou transferências de animais aquáticos, quer para as espécies locais e meio ambiente, como para a para a saúde pública.Concerning the need to choose the most convenient species to cultivate in order to implement aquaculture in Portugal, the author draws the attention to the deleterious consequences of introductions and transfers of aquatic animals.Caixa Geral de Depósito
Monsoons. WMO - No. 613
No full textChapter 1 - Monsoons Chapter 2 - Planetary aspects of monsoons Chapter 3 - Regional aspects of monsoons Chapter 4 - Barotropic and baroclinic instability Chapter 5 - The numerical simulation of monsoons Chapter 6 - Monsoons and orographic barriers Chapter 7 - The oceanic response to monsoon winds Chapter 8 - Long-range prediction and predictabilityKWP-collectio
Application of failure and fracture criteria during a tanker head-on collision
No full textIn this paper a discussion of three failure criteria during a tanker collision takes place. The 'Fracture Criterion' developed recently [Glykas, A., Samouelides, E., Das, P.K. (1996) Energy absorption capacity of plates under lateral loading. Proceedings of the 6th International Conference of Offshore and Polar Engineers, Los Angeles '96, Vol. IV, pp. 502-509.], deals with the amount of energy required so that arbitrary crack propagation originates from microscopic material flaws of the steel structure, in areas of high strain concentration during large deflections. This fracture criterion is applied in critical areas of a tanker bow structure during head-on collision with a vertical rigid body and its validity is examined in comparison to other two state of the art failure criteria. The penetration of the tanker vessel as well as the time to rest from the initiation of the collision are determined in relation to the failure criteria
Effect of Complexing with Silica Nanoparticles on the Phototoxicty of Some Photosensitisers
No full textAbstractThe paper reports the results of the studies carried out by us on the changes in the phototoxicity of some hydrophilic (Chlorin-p6, Merocyanine 540, Rose Bengal) and hydrophobic photosensitisers (Curcumin) in presence of silica nanoparticles (NP). The electrostatically bound complexes of these hydrophilic photosensitisers obtained by simple mixing of PS and NP exhibited enhanced toxicity compared to the free PS. While for Chlorin-p6, the increased photostability of the Cp6-NP complex was found to be the main contributor for the enhanced toxicity, in case of Rose Bengal, the cellular uptake of the complex was larger as compared to free drug and in Merocyanine 540 a reduction in the photoisomerization rate was the main factor responsible for increased phototoxicity. Further, whereas, the covalently bound complexes of NP with Rose Bengal and Chlorin-p6 showed higher cellular uptake, these tended to aggregate over a period of time. Addition of NP to a solution of Curcumin was observed to reduce the hydrolysis of Curcumin and compared to free Curcumin, the NP-Curcumin complex was observed to result in higher uptake and phototoxicity in oral carcinoma cells and tumor spheroids
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Author Correction: Layer-dependent quantum cooperation of electron and hole states in the anomalous semimetal WTe2.
No full textCorrection to: Nature Communications; https://doi.org/10.1038/ncomms10847, published online 29 Feb 2016.
This Article contains an error in the spelling of the author A. Yazdani, which is incorrectly given as A. Yadzani. The error has not been fixed in the original PDF and HTML versions of the Article.This Article contains an error in the spelling of the author A. Yazdani, which is incorrectly given as A. Yadzani. The error has not been fixed in the original PDF and HTML versions of the Article
P. K. Das to My dear brother (13 October 1962)
No full texthttps://egrove.olemiss.edu/mercorr_pro/2152/thumbnail.jp
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