Remedial Measures to Seepage and Instability Aspect of a Dam Near Bombay

The paper describes the distress caused to a minor earth dam constructed at a high elevation in a mountainous area to conserve water. The distress related to instability of the dam and also due to high percolation underneath the dam coupled with formation of piping. The remedial measures taken to rectify instability and reduce percolation are described in this paper

Nature and Properties of Earthquake Energy and Waves and their Contribution to Liquefaction Aspects at Adani Port During 2001 Bhuj Earth Quake

During Bhuj earthquake of 2001, certain distinct phenomenon in coastal saturated granular deposits were observed causing extensive distress to Adani Port facilities. An attempt is made to analyse the root cause by examining nature and properties of earthquake energy, geometry of earth and the origin of energy and propagation of waves, including excess pore water pressure contributed by Pwave. Although pile raft system were less damaged due to liquefaction, the tests showed extensive loss of load capacity. These aspects are presented in this paper

Stability of Hill Slopes and Foundation Condition at Radio Astronomy Centre Ootacamand

Stability aspects of hill slopes and foundation considerations of Radio Astronomy Centre at Ootacamand are described. The analysis of slopes indicated that if joints are not covered, the material in joints may lose strength and the slopes may enter a state of instability. Footings with inclined legs were found to resist the horizontal forces, pull and overturning movements. Lime piles adopted for strengthening soft material at one of the tower locations were found to be effective

Green nanotechnology from cumin phytochemicals : generation of biocompatible gold nanoparticles

Published in final edited form as: Int J Green Nanotechnol Biomed. 2009 January 1; 1(1): B39-B52. doi:10.1080/19430850902931599.The powerful antioxidant characteristics of various phytochernicals within cumin prompted us to test their efficacy in reducing sodium tetrachloroaurate to corresponding gold nanoparticles. We, herein, report an unprecedented synthetic route that involves the production of well-defined spherical gold nanoparticles by simple mixing of cumin to an aqueous solution of sodium tetrachloro aurate. Production of gold nanoparticles in this cumin-mediated Green Nanotechnological process is achieved under biologically benign conditions. The gold nanoparticles generated through cumin-mediated process did not aggregate suggesting that the cocktail of phytochemicals including proteins serve as excellent coatings on nanoparticles and thus, provide robust shielding from aggregations. In addition, the phytochemical coatings on nanoparticles have rendered nontoxic features to these 'Green Gold Nanoparticles' as demonstrated through detailed MTT assays performed on 'normal fibroblast cells. Results of our studies presenting a new 'Nano-Naturo' connection for the production and utility of gold nanoparticles for potential applications in nanomedicine and nanotechnology are discussed in this paper.This work has been supported by the generous support from the National Institutes of Health/National Cancer Institute under the Cancer Nanotechnology Platform program (grant number: 5R01CA119412-01), NIH - 1R21CA128460-01 and University of Missouri-Research Board - Program C8761 RB 06-030

A Novel Method to Monitor Sequential Displacement of Capped Ligands in Gold Nanoparticles [abstract]

Nanoscience Poster SessionNanochemistry of ligand displacement reactions has attracted much attention in recent years for the development of myriad of new gold nanomaterials. Gold nanoparticles have shown applications ranging from tumor imaging agent in nanomedicine to single electron devices in information technology. New gold materials are synthesized by exchange of neutral or anionic ligands with thiolated molecules. Completion of ligand substitution reactions in gold nanoparticles are monitored by using UV-Vis spectrometry. However, there are no methods available to monitor the sequence of the ligand substitution reactions. Monitoring and predicting the sequence of ligand substitutions would provide a convenient handle for the design and development of hybrid nanomaterials containing two or more ligands. In this context, we have developed a novel technique utilizing disc centrifuge systems to monitor the sequential displacement of ligands in various gold nanoconstructs. In our studies, we have used gold nanoparticles stabilized with both anionic and neutral ligands. Gold nanoparticles of various different substitutions have been identified and characterized by disc centrifuge systems. Details of substitution reactions and mechanism on monitoring the sequential displacement using strong ligands will be presented

Agarose-stabilized gold nanoparticles for surface-enhanced Raman spectroscopic detection of DNA nucleosides

doi:10.1063/1.2192573 http://scitation.aip.org/getpdf/servlet/GetPDFServlet?filetype=pdf&id=APPLAB000088000015153114000001&idtype=cvips&prog=normal&doi=10.1063/1.2192573We present surface-enhanced Raman scattering (SERS) studies of DNA nucleosides using biologically benign agarose-stabilized gold nanoparticles (AAuNP). We compare the SERS activity of nucleosides with AAuNP to that of commercially obtained citrate-stabilized gold nanoparticles and find the SERS activity to be an order of magnitude higher with AAuNP. The higher SERS activity is explained in terms of the agarose matrix, which provides pathways for the gold nanoparticles to have distinct arrangements that result in stronger internal plasmon resonances.This work was supported through the University of Missouri Research Board grants URB04-023 (S.G.) and URB03-080 (M.C. and K.V.K.), NSF under Grant No. DMR-0413601and the NCI under Grant No. IR0ICA119412-01. The gold nanoparticles were produced and supplied by the University of Missouri Nanoparticle Production Core Facility

Fluctuations and Instabilities of Ferromagnetic Domain Wall pairs in an External Magnetic Field

Soliton excitations and their stability in anisotropic quasi-1D ferromagnets are analyzed analytically. In the presence of an external magnetic field, the lowest lying topological excitations are shown to be either soliton-soliton or soliton-antisoliton pairs. In ferromagnetic samples of macro- or mesoscopic size, these configurations correspond to twisted or untwisted pairs of Bloch walls. It is shown that the fluctuations around these configurations are governed by the same set of operators. The soliton-antisoliton pair has exactly one unstable mode and thus represents a critical nucleus for thermally activated magnetization reversal in effectively one-dimensional systems. The soliton-soliton pair is stable for small external fields but becomes unstable for large magnetic fields. From the detailed expression of this instability threshold and an analysis of nonlocal demagnetizing effects it is shown that the relative chirality of domain walls can be detected experimentally in thin ferromagnetic films. The static properties of the present model are equivalent to those of a nonlinear sigma-model with anisotropies. In the limit of large hard-axis anisotropy the model reduces to a double sine-Gordon model.Comment: 15 pages RevTex 3.0 (twocolumn), 9 figures available on request, to appear in Phys Rev B, Dec (1994