A novel integrated platform combining atomic force microscopy and fluorescence correlation spectroscopy

At the nanoscale near an interface, the discrete nature of liquids is expected to influence various properties, such as density, viscosity or diffusion constants. Understanding interfacial properties of liquids is important for the development of nanotechnology, especially for the fields of nano-rheology and nano-tribology, and also for understanding various mechanisms in biological systems at the molecular level, such as protein folding or the self-assembly of lipid vesicles, which invariably involve liquids. Atomic force microscope (AFM) and fluorescence correlation spectroscope (FCS) are two complimentary techniques that are commonly employed investigate mechanics and dynamics of liquids at interfaces. In this thesis, the design and construction of a novel integrated platform combining AFM and FCS is presented. The platform consists of a newly built high sensitive AFM on top of an existing custom-made FCS setup. The design is modular in nature, can be easily assembled or disassembled and thus both AFM and FCS can be used independently. The successful operation was the platform was demonstrated by employing a colloidal liquid as a test system. Results of AFM experiments indicated the presence of structure to the colloidal dispersion under confinement, similar to the behavior of molecular liquids reported in the literature, at length scales of a few 10 nm. However, FCS results showed considerable decrease in the diffusion of colloidal particle even when the confinement was of the order of microns. The design, construction and the testing of the new platform along with the intriguing results will be presented

Succinct Representations of Permutations and Functions

We investigate the problem of succinctly representing an arbitrary permutation, \pi, on {0,...,n-1} so that \pi^k(i) can be computed quickly for any i and any (positive or negative) integer power k. A representation taking (1+\epsilon) n lg n + O(1) bits suffices to compute arbitrary powers in constant time, for any positive constant \epsilon <= 1. A representation taking the optimal \ceil{\lg n!} + o(n) bits can be used to compute arbitrary powers in O(lg n / lg lg n) time. We then consider the more general problem of succinctly representing an arbitrary function, f: [n] \rightarrow [n] so that f^k(i) can be computed quickly for any i and any integer power k. We give a representation that takes (1+\epsilon) n lg n + O(1) bits, for any positive constant \epsilon <= 1, and computes arbitrary positive powers in constant time. It can also be used to compute f^k(i), for any negative integer k, in optimal O(1+|f^k(i)|) time. We place emphasis on the redundancy, or the space beyond the information-theoretic lower bound that the data structure uses in order to support operations efficiently. A number of lower bounds have recently been shown on the redundancy of data structures. These lower bounds confirm the space-time optimality of some of our solutions. Furthermore, the redundancy of one of our structures "surpasses" a recent lower bound by Golynski [Golynski, SODA 2009], thus demonstrating the limitations of this lower bound.Comment: Preliminary versions of these results have appeared in the Proceedings of ICALP 2003 and 2004. However, all results in this version are improved over the earlier conference versio

Design and Development of an Airblast Atomiser for the KAVERI engine and the sectoral combustor tests

This report deals with the design and development of an airblast atomiser for application in the KAVERI engine. Five atomisers of the chosen design were fabricated and tested at ambient conditions to determine the fuel spray SMD, patternation, cone angle and atomiser flow number. The atomiser performance parameters specified were achieved and hot tests carried out in the 90° combustor sector. The combustor pressure loss, exit temperature distribution, ignition and stability limits were evaluate

NRASIM: A Design Toolbox for Multi-Spacecraft Interferometric Telescopes

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76895/1/AIAA-2003-5604-851.pd

Biconnectivity, Chain Decomposition and st-Numbering Using O(n) Bits

Recent work by Elmasry et al. (STACS 2015) and Asano et al. (ISAAC 2014) reconsidered classical fundamental graph algorithms focusing on improving the space complexity. Elmasry et al. gave, among others, an implementation of depth first search (DFS) of a graph on n vertices and m edges, taking O(m lg lg n) time using O(n) bits of space improving on the time bound of O(m lg n) due to Asano et al. Subsequently Banerjee et al. (COCOON 2016) gave an O(m + n) time implementation using O(m+n) bits, for DFS and its classical applications (including testing for biconnectivity, and finding cut vertices and cut edges). Recently, Kammer et al. (MFCS 2016) gave an algorithm for testing biconnectivity using O(n + min{m, n lg lg n}) bits in linear time. In this paper, we consider O(n) bits implementations of the classical applications of DFS. These include the problem of finding cut vertices, and biconnected components, chain decomposition and st-numbering. Classical algorithms for them typically use DFS and some Omega(lg n) bits of information at each node. Our O(n)-bit implementations for these problems take O(m lg^c n lg lg n) time for some small constant c (c leq 3). Central to our implementation is a succinct representation of the DFS tree and a space efficient partitioning of the DFS tree into connected subtrees, which maybe of independent interest for space efficient graph algorithms

ENHANCED ORAL BIOAVAILABILITY OF TENOFOVIR FROM IONOTROPICALLY GELLED MICROBEADS

Objective: The main objective of the present investigation was to develop microbeads of tenofovir. Tenofovir, a BCS class III drug has a poor bioavailability of 25%, and it is administered 300 mg once a day. By incorporating the drug into a microparticulate carrier, it is expected that the dissolution profile and the oral bioavailability may be increased. Methods: Reinforced gellan-chitosan and calcium chloride beads of tenofovir were prepared by ionotropic gelation method employing various different concentrations of gellan, chitosan, calcium chloride and tenofovir. The beads were evaluated for various physico-chemical parameters such as particle size determination, drug entrapment efficiency, swelling studies, infra red spectroscopy study, differential scanning calorimetry, x-ray diffraction analysis, scanning electron microscopy, in vitro drug release study, cytotoxicity study and in vivo oral bioavailability studies. Results: From the results, it can be concluded that the formulation TB-III exhibited higher drug entrapment efficiency (46.09±0.21), a higher swelling index, sustained drug release for a period of 24 h. The pharmacokinetic profile of the drug from microbeads exhibited an increased oral bioavailability (1.25 times higher than that of pure drug), decreased elimination rate (1.32 times lesser for drug in microbeads) with prolonged elimination half-life (1.32 times higher than pure tenofovir). Conclusion: Tenofovir loaded microbeads demonstrated as a better delivery system for the modified release of drug and also to navigate the drawbacks associated with the conventional therapy