61 research outputs found
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
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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
Scalable functional validation of next generation SoCs
No full textSystem-on-Chips (SoCs) constitutes the primary backbone of modern embedded computing devices including many safety-critical applications e.g., autonomous vehicles, health care systems. The presence of any undetected bugs in these systems would have aberrant cost both in terms of safety and reliability and can cause loss of property or life. Hence, SoC validation is a crucial task to ensure the functional correctness of an SoC. The sheer size, presence of hundreds of concurrently executing heterogeneous IPs, vertical integration of SoC components e.g., hardware/firmware/software to realize multiple functionality, and application-level relevance of components present a new spectrum of validation challenges that have rendered the traditional microprocessor validation paradigm moot in the context of SoC validation. The challenges include observability enhancement and debug and diagnosis under the constraint of vertical integrations, identifying high-quality verification artifacts among others. In industrial practice, SoC validation is a manual, unsystematic, and ad hoc process that heavily relies on the expertise and the creativity of the validator. Consequently, there is an urgent need to develop scalable and efficient algorithms of industrial relevance to address this massive ongoing challenge of SoC validation.
This dissertation makes contributions to both post-silicon and pre-silicon validation of SoCs, with highly impactful contributions to next-generation post-silicon SoC validation. We use top-down analysis, a higher level of abstraction, and application relevance as the key ideas to automate post-silicon observability enhancement for industrial scale SoCs and scale observability to design that is more than 300x the size of designs that have been presented in the academic literature so far. Our observability enhancement solution can be applied at the netlist-level, behavioral level, and at the system-wide application level to select high-quality signals that are most beneficial for post-silicon debug and diagnosis. We apply a feature engineering based machine learning technique on the observed signal data to develop an automatic, scalable, and efficient post-silicon debug and diagnosis solution. The key idea is to learn the correct and erroneous design behavior automatically from trace data without prior design knowledge. We believe our debugging solution can automate post-silicon debug and diagnosis, where manual debugging is the norm. The quality of SoC verification and validation heavily depends on the quality of verification artifacts e.g., assertions. To automate and expedite identification of high-functional coverage assertions that are useful for regression analysis, localization, etc., we have also developed a comprehensive ranking scheme for assertions. The key idea is to identify assertions that capture important design behaviors by analyzing the design source code.
Our SoC validation solutions are scalable and efficient. We consistently show orders of magnitude speedup improvements over the state-of-the-art while objectively improving quality of results. We have shown that going forward application-level analysis is the key to scale post-silicon validation to industrial scale SoCs. Our proposed validation solutions can plug into the existing industrial validation process to introduce automation in the current unsystematic, ad hoc, manual settings with multiple order of magnitudes of benefit.Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2021-08-01The student, Debjit Pal, accepted the attached license on 2019-07-11 at 09:37.The student, Debjit Pal, submitted this Dissertation for approval on 2019-07-11 at 09:53.This Dissertation was approved for publication on 2019-07-11 at 10:56.DSpace SAF Submission Ingestion Package generated from Vireo submission #14264 on 2019-11-26 at 13:05:22Made available in DSpace on 2019-11-26T20:49:27Z (GMT). No. of bitstreams: 3
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Previous issue date: 2019-07-11Embargo set by: Seth Robbins for item 112957
Lift date: 2021-11-26T20:49:41Z
Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD systemU of I Only Restriction Lifted for Item 112957 on 2021-11-27T10:15:23Z
Nonlinear features of electrostatic waves in a plasma with nonthermal-Tsallis distributed electrons
No full textNonlinear Structures in an Ion-Beam Plasmas Including Dust Impurities with Nonthermal Nonextensive Electrons
No full textCollected Papers (on Physics, Artificial Intelligence, Health Issues, Decision Making, Economics, Statistics), Volume XI
No full textThis eleventh volume of Collected Papers includes 90 papers comprising 988 pages on Physics, Artificial Intelligence, Health Issues, Decision Making, Economics, Statistics, written between 2001-2022 by the author alone or in collaboration with the following 84 co-authors (alphabetically ordered) from 19 countries: Abhijit Saha, Abu Sufian, Jack Allen, Shahbaz Ali, Ali Safaa Sadiq, Aliya Fahmi, Atiqa Fakhar, Atiqa Firdous, Sukanto Bhattacharya, Robert N. Boyd, Victor Chang, Victor Christianto, V. Christy, Dao The Son, Debjit Dutta, Azeddine Elhassouny, Fazal Ghani, Fazli Amin, Anirudha Ghosha, Nasruddin Hassan, Hoang Viet Long, Jhulaneswar Baidya, Jin Kim, Jun Ye, Darjan Karabašević, Vasilios N. Katsikis, Ieva Meidutė-Kavaliauskienė, F. Kaymarm, Nour Eldeen M. Khalifa, Madad Khan, Qaisar Khan, M. Khoshnevisan, Kifayat Ullah,, Volodymyr Krasnoholovets, Mukesh Kumar, Le Hoang Son, Luong Thi Hong Lan, Tahir Mahmood, Mahmoud Ismail, Mohamed Abdel-Basset, Siti Nurul Fitriah Mohamad, Mohamed Loey, Mai Mohamed, K. Mohana, Kalyan Mondal, Muhammad Gulfam, Muhammad Khalid Mahmood, Muhammad Jamil, Muhammad Yaqub Khan, Muhammad Riaz, Nguyen Dinh Hoa, Cu Nguyen Giap, Nguyen Tho Thong, Peide Liu, Pham Huy Thong, Gabrijela Popović, Surapati Pramanik, Dmitri Rabounski, Roslan Hasni, Rumi Roy, Tapan Kumar Roy, Said Broumi, Saleem Abdullah, Muzafer Saračević, Ganeshsree Selvachandran, Shariful Alam, Shyamal Dalapati, Housila P. Singh, R. Singh, Rajesh Singh, Predrag S. Stanimirović, Kasan Susilo, Dragiša Stanujkić, Alexandra Şandru, Ovidiu Ilie Şandru, Zenonas Turskis, Yunita Umniyati, Alptekin Ulutaș, Maikel Yelandi Leyva Vázquez, Binyamin Yusoff, Edmundas Kazimieras Zavadskas, Zhao Loon Wang.
Synthetic Chemoselective Rewiring of Cell Surfaces: Generation of Three-Dimensional Tissue Structures
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