678 research outputs found
Dynamics of Network Formation Processes in the Co-Author Model
No full textThis article studies the dynamics in the formation processes of a mutual consent network in game theory setting: the Co-Author Model. In this article, a limited observation is applied and analytical results are derived. Then, 2 parameters are varied: the number of individuals in the network and the initial probability of the links in the network in its initial state. A simulation result shows a finding that is consistent with an analytical result for a state of equilibrium while it also shows different possible equilibria.Dynamics, Network, Game Theory, Model,Simulation, Equilibrium, Complexity
RCSB Protein Data Bank: A Resource for Chemical, Biochemical, and Structural Explorations of Large and Small Biomolecules
No full textThe Research Collaboratory for Structural Bioinformatics (RCSB) Protein Data Bank (PDB) supports scientific research and education worldwide by providing access to annotated information about three-dimensional (3D) structures of macromolecules (e.g., nucleic acids, proteins), and associated small molecules (e.g., drugs, cofactors, inhibitors) in the PDB archive. Researchers, educators, and students use RCSB PDB resources to study the shape and interactions of biological molecules and their implications in molecular biology, medicine, biotechnology, and beyond. RCSB PDB supports development of standards for data deposition, representation, annotation, and validation of atomic structural data obtained from various experimental methods. Uniform representation of PDB data is essential for providing consistent search and analysis capabilities for all PDB users, from beginning students to domain experts. The RCSB PDB Web site provides tools for searching, visualizing, and analyzing PDB data, including easy exploration of chemical interactions that stabilize macromolecules and play important roles in their interactions and functions. In addition, educational resources are available for free and unrestricted use in the classroom for exploring chemistry and biology at the molecular level.This document is the Accepted Manuscript version of a Published Work that appeared in final form in Journal of Chemical Education, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://dx.doi.org/10.1021/acs.jchemed.5b00404Peer reviewe
Development of chromium doped nanoengineered YAS glass based optical fibers with and without rare-earths for use as a saturable absorber to make pulse fiber laser along with broadband sources
No full textThe demand of high bandwidth in optical communications as well as increasing need
for tunable fiber laser source and laser cavity components like fiber saturable absorber for allfiber
application lead to search for new materials that can serve for said purposes and besides
provide other applications like fiber dosimetry. In this dissertation, chromium especially in
+4 state in glass core of preform has been fabricated (using MCVD solution doping method)
and drawn to fiber to investigate their different properties. Although chromium in different
crystal hosts and in some kind of glasses is known to posses desired properties but those are
not reported in case of fiber-based system. Nevertheless, the development of such Cr-doped
fiber is challenging because of multiple bottlenecks such as chromium evaporation problem,
stabilization of Cr+4, achieving nano-phase separated core etc. Accordingly, various material
characterization techniques viz. Scanning Electron Microscopy, Transmission Electron
Microscopy, X-ray Photoelectron Spectroscopy, X-Ray Diffraction, Electron Probe Micro
Analysis etc. are used to optimize different process parameters to achieve the desire target.
Nano-engineering of core glass in terms of nano-phase separation has been
administrated by thermal annealing and investigated using optical and material
characterizations. The compositional variations and microscopic study between the phases in
phase separated core glass was carried out by spot energy dispersive X-ray in conjunction
with TEM. Other fabrication method like powder-in-tube (PIT) was also tried using wet
chemical method for synthesis of YAG crystal powder followed by fiber implementation and
respective characterizations.
Some representative fabricated yttria-alumino-silicate (YAS) based fibers were set for
experiment. Presence of different oxidation states including the desired +4 state is inferred
from absorption spectra and emission spectra at NIR region with proper excitation
wavelength. Fluorescence lifetime, photo-bleaching and Raman spectra are also investigated
besides study on influence of divalent alkaline earth ions towards retention of Cr+4 ion in
ultimate fiber core.
The fibers were also set for the experiment regarding the electron irradiation effect
resulting characteristic induced absorption and its posterior optical bleaching property (at
633/1070 nm wavelengths) has been investigated. In this experiment we also established that
the desired properties of fibers are depends on Cr+4 ion whose amount in turn determined on
9
some divalent alkaline earth ions (Mg here). The study indicates the potentiality of the
fabricated fibers in dosimetric application.
Another important feature, saturable absorption, has been studied at 1.55 μm and 2
μm region for some representative fabricated fibers. Incorporating them in different laser
cavities (EDFL and TDFL) show pulsed laser output, even nanosecond pulse (EDFL
produces 432 ns pulse width, while TDFL produces 59 ns pulse width) also achieved.
Effect of chromium codoping on rare-earths like erbium (Er) doped fiber has also
been studied due to the overlapping fluorescence band of both ions expecting improvement in
erbium lasing. The fabricated fibers were compared with pure erbium doped fiber shows
improvement in terms of the ratio of bleached to residual resonant absorption and net-gain to
small signal absorption emerges as useful for core pumping NIR applications. Besides,
reduced up-conversion phenomena and long NIR fluorescence lifetimes put positive remark
on the fabricated fibers
Chemoselective Liposome Fusion for Cell-Surface and Tissue Engineering Applications
No full textProper cell-cell communication through physical contact is crucial for a range of fundamental biological processes including, cell proliferation, migration, differentiation, and apoptosis and for the correct function of organs and other multi-cellular tissues. The spatial and temporal arrangements of these cellular interactions in vivo are dynamic and lead to higher-order function that is extremely difficult to recapitulate in vitro. The development of 3-dimensional (3D), in vitro model systems to investigate these complex, in vivo interconnectivities would generate novel methods to study the biochemical signaling of these processes, as well as provide platforms for tissue engineering technologies. Herein, we develop and employ a strategy to induce specific and stable cell-cell contacts in 3D through chemoselective cell-surface engineering based on liposome delivery and fusion to display bio-orthogonal functional groups from cell membranes. This strategy uses liposome fusion for the delivery of ketone or oxyamine groups to different populations of cells for subsequent cell assembly via oxime ligation. We demonstrate how this method can be used for several applications including, the delivery of reagents to cells for fluorescent labeling, the formation of small, 3D spheroid cell assemblies, and the generation of large and dense, 3D multi-layered tissue-like structures. We were also able to create dynamic and switchable cell tissue assemblies through chemoselective conjugation and release chemistry. Cell membranes are decorated with a range of molecules that can be released in vitro for subsequent rounds of molecular conjugation and release. Each step to modify the cell surface: activation, conjugation, release, and regeneration can be monitored and modulated by non-invasive, label-free analytical techniques. Additionally, we also develop and demonstrate a novel liposome fusion based delivery strategy to incorporate a unique bio-orthogonal lipid that has the dual ability to serve as a receptor for chemoselective cell surface tailoring and as a reporter to track cell behavior
A Review Of Research By Soumitra Dutta Titled “Strategies For Implementing Knowledgebased Systems”
No full textThe management of organizational knowledge, a relatively new and challenging concept for most organizations, is introduced and discussed in this paper. Around this general topic, the author, Dr. Dutta conducted a series of important concepts from knowledge, organizational knowledge or organizational knowledge assets, Knowledge-Based Systems (KBS’s), to implementation strategies for KBS’s. There is an increasing consensus that the effective management of knowledge is an important basis of competitive advantage for corporations, and that KBS’s can have an important role in the management of organizational knowledge at all levels. Based on an understanding that with considerable progress in the underlying technologies, the major challenges in the implementation of KBS’s have evolved from technical matters and to organizational and strategic issues, Dr. Dutta proposed four different strategies ( guided, specialist, dispersed points, and dispersed clusters) and described them in relation to the different levels of organizational knowledge and the locus of responsibility for the development of KBS’s. Then, the technical, managerial and strategic implications of each of the four strategies have been discussed
Applications of balance optimization subset selection
No full textBalance Optimization Subset Selection (BOSS) is a framework designed to be used for causal inference on observational data. The theoretical foundation for the BOSS framework has been provided in the literature; this thesis aims to provide some examples of the practical value of BOSS by using it on two problems. The first application is using BOSS to determine a subset of users who would be suitable targets for marketing efforts, and the second application is using BOSS to identify potential first-round upsets in the NCAA basketball tournament. Finally, this thesis delves into another area of college basketball and attempts to model the process of the NCAA tournament selection committee using a decision tree.Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2018-08-01The student, Shouvik Dutta, accepted the attached license on 2016-07-19 at 12:51.The student, Shouvik Dutta, submitted this Thesis for approval on 2016-07-19 at 12:54.This Thesis was approved for publication on 2016-07-21 at 14:08.DSpace SAF Submission Ingestion Package generated from Vireo submission #10013 on 2016-11-10 at 12:21:00Made available in DSpace on 2016-11-10T18:27:07Z (GMT). No. of bitstreams: 2
DUTTA-THESIS-2016.pdf: 645024 bytes, checksum: 2db51a406961fe95b3cc42b8d0e55feb (MD5)
LICENSE.txt: 4210 bytes, checksum: c742995ea6b0e1b88acbf8698e6a703a (MD5)
Previous issue date: 2016-07-21Embargo set by: Seth Robbins for item 95292
Lift date: 2018-11-10T18:28:02Z
Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemLimited Restriction Lifted for Item 95292 on 2018-11-11T10:15:19Z
Similarities between 2D and 3D convection for large Prandtl number
No full textUsing direct numerical simulations of Rayleigh-B\'enard convection (RBC), we perform a comparative study of the spectra and fluxes of energy and entropy for large and infinite Prandtl numbers in two (2D) and three (3D) dimensions. We observe close similarities between the 2D and 3D RBC, in particular the kinetic energy spectrum , and the entropy spectrum exhibits a dual branch with a dominant spectrum. We showed that the dominant Fourier modes in the 2D and 3D flows are very close
Energy-based Reference-Free Damage Diagnosis using A Single Pair of Collocated PZTs
No full textThis research is supported by the Radiation Technology Program (M20703000015-07N0300-01510) under Korea Science and Engineering Foundation (KOSEF) and U-Eco city project (C007L7510001-08L015800110) under Korea Institute of Construction & Transportation technology Evaluation and Planning (KICTEP). Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the funding agencies
The Political Economy of the Corporation: Sahil Jai Duta Interviews Sandy Brian Hager
No full textPERC’s Sahil Jai Dutta is joined by Dr Sandy Brian Hager (City, University of London) to discuss the political economy of the corporation. He is the author of the book Public Debt, Inequality, and Power: The Making of a Modern Debt State (2016) published by University of California Press. The conversation spans across the topics of ownership and the politics of public debt, the power of large banks in the US, and his most recent work exploring what drives long-term shifts in the stock markets in the ‘advanced’ economies
Nonlinear features of electrostatic waves in a plasma with nonthermal-Tsallis distributed electrons
No full text- …
