KINETICS OF SURFACE-INITIATED PHOTOINIFERTER-MEDIATED PHOTOPOLYMERIZATION AND SYNTHESIS OF STIMULI-RESPONSIVE POLYMER BRUSHES

The focus of this research is to understand the kinetic and mechanistic aspects of surface-initiated photoiniferter-mediated photopolymerization (SI-PMP) and exploit the robustness of SI-PMP to synthesize stimuli-responsive polymer brushes. The \u27living\u27 characteristics of dithiocarbamate-based photoiniferter-mediated photopolymerization are well documented. However, in this dissertation I show that the growth of poly(methyl methacrylate) (PMMA) brushes by SI-PMP is nonlinear, suggesting loss of radicals during SI-PMP and, in turn, non-living characteristics. Results from kinetic models in conjunction with experimental results suggest that irreversible bimolecular termination reactions are a primary culprit for the loss of radicals during SI-PMP. To overcome this problem of irreversible termination reactions, tetraethylthiuram disulfide (TED), a source of deactivating dithiocarbamyl radicals, was added to the SI-PMP system. Preaddition of TED successfully reduced irreversible termination reactions. Contention of decrease in irreversible termination reactions is further supported by results from reinitiation studies using styrene: reinitiation efficiency, as indicated by the thickness of the added polystyrene block, increases as TED concentration increases. The impact of various photopolymerization conditions on SI-PMP is further investigated by simulating the SI-PMP process using a rate-based model. With this approach the effect of photopolymerization conditions such as light intensity, TED concentration, exposure time and initial photoiniferter concentration on the growth kinetics and reinitiation ability of PMMA layers has been studied in detail. The simulations show that increases in [TED] and decreases in light intensity impact the PMMA layer propagation in similar fashions; these trends are observed in experiments. However, simulations also indicate that the effect of [TED] and light intensity on the reinitiation ability of PMMA layers are significantly different: reinitiation ability increases with increasing [TED], but decreasing light intensity does not improve reinitiation ability. The simulations also show that choice of photopolymerization conditions used during the first polymerization step is critical to the final structure of the polymer brush created upon reinitiation: PMMA layers formed in the presence of TED are more likely to form block copolymers as compared to PMMA layers synthesized without TED and at lower light intensity. Strategies learned from these simulations and experiments were applied for the synthesis of bi-level, multiresponsive poly(methacrylic acid)-block-poly(N-isopropyl-acrylamide) (PMAA-b-PNIPAM) layers. In-situ multi-angle ellipsometry investigations of these layers demonstrate that these layers respond to changes in pH, temperature and ionic strength. While the individual blocks retain their customary responsive characteristics, the overall swelling behavior of the PMAA-b-PNIPAM layers can be tuned by any number combinations of pH, temperature and ionic strength. The efforts described in this dissertation, demonstrate not only the robustness of SI-PMP for making a variety of functional polymer brushes, but also the complex links between synthesis, structure and properties of polymer brushes

EFFICIENT ENHANCEMENT OF MICRO-NUCLEATION RATES IN FLOW-BOILING - BY CONCURRENT MICRO-STRUCTURING OF THE BOILING-SURFACE AND ITS JUDICIOUS ENERGIZATION BY PIEZOELECTRIC-TRANSDUCER INDUCED ACOUSTIC VIBRATIONS.

The report describes the science and technology backgrounds and uses for the technology breakthrough reported for enhanced flow-boiling based cooling of high-power density electronics (chips, memory etc.). A controlled but explosive growth in micro-scale nucleation rates during flow-boiling of HFE-7100 (electronics and environment friendly liquid from 3M, Inc) is enabled by the uses of inexpensive meshed-copper for micro-structuring of the boiling surface and a pair of Piezoelectric-transducers for active imposition of suitable acoustic vibrations. The pair of piezo transducers mounted just outside the mini-channel impose “in plane” acoustic vibrations of controllable amplitudes and frequencies, and they are used to induce phenomena which make flow-boiling highly efficient. Superposition of such active resonant acoustics towards beneficial actuation of the bubbles’ ebullition cycles, where mesh-tips\u27 minuscule structural vibrations play key roles, are an important part of the enabling science and technology. Even preliminary results show, relative to currently popular water-based Direct Contact Liquid Cooling (DCLC) or Direct to Chip (D2C) liquid cooling approaches, heat transfer efficiency goes up by 700%, driving temperature difference goes down by 80-90%, maximum allowed average heat-flux goes up from about 35 W/cm2 to more than 70 – 100 W/cm2, and boiling surface temperatures can be adjusted in the range of 50 - 650C (as needed) relative to the maximum allowed chip junction temperature of 80 - 850C (or less)

Measures of Complexity for Large Scale Image Datasets

Large scale image datasets are a growing trend in the field of machine learning. However, it is hard to quantitatively understand or specify how various datasets compare to each other - i.e., if one dataset is more complex or harder to ``learn'' with respect to a deep-learning based network. In this work, we build a series of relatively computationally simple methods to measure the complexity of a dataset. Furthermore, we present an approach to demonstrate visualizations of high dimensional data, in order to assist with visual comparison of datasets. We present our analysis using four datasets from the autonomous driving research community - Cityscapes, IDD, BDD and Vistas. Using entropy based metrics, we present a rank-order complexity of these datasets, which we compare with an established rank-order with respect to deep learning.Comment: 6 pages, 3 tables, 4 figure

Image Analysis, Brightness Improvement and Enhancement of Image using Histogram Equalization Technique

The histogram Equalization is simple Brightness improvement technique. Simplification is the key factor of the Histogram Equalization. This paper represent the how brightness will improve using the function which are given in the paper. The paper proposes the function which is Probability density function and Cumulative distributive function these function can help to show the grey level image and Brightness Improvement in output image. DOI: 10.17762/ijritcc2321-8169.16046

A REVIEW ON FAST DISSOLVING TABLET

The convenience of administration and improved patient compliance are important in the design of oral drug delivery system which remains the preferred route of drug delivery inspite of various disadvantages. Fast disintegrating tablets (FDTs) have received ever-increasing demand during the last decade, and the field has become a rapidly growing area in the pharmaceutical industry. The popularity and usefulness of the formulation resulted in development of several FDT technologies. These techniques render the disintegration of tablet rapidly and dissolve in mouth in five seconds without chewing and the need of water which is advantageous mainly for pediatrics, geriatrics and patients having difficulty in swallowing tablets and capsules. Formulation of a convenient dosage form for administration, by considering swallowing difficulty and poor patient compliance, leads to development of orally disintegrating tablets. Conventional preparation methods are spray drying, freeze drying, direct compression, Molding, and sublimation while new technologies have been developed for the production of orodispersible tablets. Keywords: Fast Dissolving Tablet, drug delivery system, fast disintegrating, fast melting

Enhancing fluorescence excitation and collection from the nitrogen-vacancy center in diamond through a micro-concave mirror

We experimentally demonstrate a simple and robust optical fibers based method to achieve simultaneously efficient excitation and fluorescence collection from Nitrogen-Vacancy (NV) defects containing micro-crystalline diamond. We fabricate a suitable micro-concave (MC) mirror that focuses scattered excitation laser light into the diamond located at the focal point of the mirror. At the same instance, the mirror also couples the fluorescence light exiting out of the diamond crystal in the opposite direction of the optical fiber back into the optical fiber within its light acceptance cone. This part of fluorescence would have been otherwise lost from reaching the detector. Our proof-of-principle demonstration achieves a 25 times improvement in fluorescence collection compared to the case of not using any mirrors. The increase in light collection favors getting high signal-to-noise ratio (SNR) optically detected magnetic resonance (ODMR) signals hence offers a practical advantage in fiber-based NV quantum sensors. Additionally, we compacted the NV sensor system by replacing some bulky optical elements in the optical path with a 1x2 fiber optical coupler in our optical system. This reduces the complexity of the system and provides portability and robustness needed for applications like magnetic endoscopy and remote-magnetic sensing.Comment: 6 pages, 8 figure

Comparing Wireless Traffic Tracking with Regular Traffic Control Systems for the Detection of Congestions in Streets

Detecting congestions on streets is one of the main issues in the area of smart cities. Regular monitoring methods can supply information about the number of vehicles in transit and thus the saturation of the streets, but they are usually expensive and intrusive with respect to the road. In recent years a new trend in traffic detection has arisen, considering the Wireless signals emitted by ‘smart’ on-board devices for counting and tracking vehicles. In this paper, two traffic monitoring methods are compared: detections using a regular Inductive Loop Detector on the road and an own Wireless Tracking System based on Bluetooth detection called Mobywit. The correlation between the day of the week and the hour with the traffic flow in a metropolitan busy street has been analysed. Assuming that our system is not able to defect all the vehicles, but just only subset of them, it is expected a causality between the results obtained using the two methods. This means, that the Bluetooth-based system can detect the same variations in the traffic flow that the regular loop detector, but having two main advantages: the tracking possibilities and a much lower cost.This work has been supported in part by project MOSOS (reference PRY142/14), which has been granted by Fundación Pública Andaluza Centro de Estudios An- daluces in the call `IX Convocatoria de Proyectos de Investigación'. It also has been partially funded by national projects TIN2014-56494-C4-3-P and TEC2015- 68752 (Spanish Ministry of Economy and Competitiveness), PROY-PP2015-06 (Plan Propio 2015 UGR), and project CEI2015-MP-V17 of the Microprojects program 2015 from CEI BioTIC Granada

Comprehensive Comparison of Various Approaches for Implementation of Expert IR System through Pre-processing and Clustering

We live in a digital world wherein tremendous electronic data evolves out every day, generating from huge amount of sources present. This data is tedious and nearly impossible to manage as it being literally large. Data storage and retrieval becomes a truly difficult task. Thus through data mining approach this type of data can be treated with various efficient techniques for cleaning, compression and sorting of data. Preprocessing can be used to remove basic English stop-words from data making it compact and easy for further processing; later dimensionality reduction techniques make data more efficient and specific. This data later can be clustered for better information retrieval. This paper elaborates the various dimensionality reduction and clustering techniques applied on sample dataset C50test of 2500 documents giving promising results, their comparison and better approach for relevant information retrieval, using tool based as well as programming based approach for providing comprehensive choices among the users