78 research outputs found
Design of Systolic Architecture Using Evolutionary Computation
No full textThis work presents a new concept for finding the optimal values for the entire three fundamental design vectors namely scheduling, projection and processor so that not only architecture design could be feasible along with that maximum hardware utilizing efficiency could be achieved. This Approach also having the focus to minimize the total delay involved with systolic architecture design. Evolutionary programming has applied to find the optimal solution. Presented work and result will provide facility to designer without any involvement to find out best suited architecture for a particular application. The Proposed method having capability to find the large number of optimal vectors for any algorithm which can be implemented in systolic architecture. The increasing demands of speed and performance in modern signal and image processing applications necessitate a revolutionary super -computing technology. The proposed method is coded in MATLAB editor and simulation environment. Shilpa V | Suma V Shetty "Design of Systolic Architecture Using Evolutionary Computation" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-2 | Issue-4 , June 2018, URL: https://www.ijtsrd.com/papers/ijtsrd15776.pd
Effect of roughness, microstructure, and chemistry on the environmental durability of structural alloys
No full textUnlike functional materials where one design property is usually optimized, structural materials need to meet several design requirements including but not limited to excellent mechanical properties and environmental tolerance. However, more often than not, the metallurgical principles used to improve mechanical properties result in a decrease in the environmental tolerance. Though it is difficult to design materials that can thrive in extreme environments like high temperature, high pressure, and harsh chemicals, these conditions are often where the biggest scientific and economic opportunities lie. Aeroengines, and oil refineries are two example applications that encounter these issues. This study specifically focusses on improving the environmental tolerance of NiCrAl films a common bond coat used in aeroengines, and ferrous alloys used in petroleum production. The goal was to develop solutions that improve the environmental tolerance while minimally affecting other properties of these alloys.
The oxidation behavior of a model sputtered NiCrAl system was studied in various time and oxygen partial pressure (pO2) regimes. Low pO2 conditions seemed to favor the formation of protective oxides. However, tuning the composition of the base alloy was an effective way to limit the oxidation rate in high pO2 conditions. Thermal destabilization of the sputtered microstructure was found to take place on similar timescales to the transient oxide formation. Thus dilute Y additions were made to temporarily stabilize the sputtered microstructure and manipulate the transient stages of oxidation.
Yttrium addition not only retarded grain growth through nanoclustering and kinetically pinning grains, but also helped nucleate and grow dense, and slow-growing oxides. In some cases, the improvement in oxidation resistance via. Y addition was similar to reducing the pO2 by several orders of magnitude. Robust α-alumina oxides formed on Y doped NiCrAl films at temperatures as low as 900 oC by oxidation in an air environment which is unprecedented and could be of major commercial importance. An attempt was made to understand this anomalous oxidation behavior by using unconventional diffusion-triples comprising of a sputtered NiCr (undoped and Y doped) top layer, Al middle layer, and a sintered (micrograined) NiCr bottom layer. Annealing experiments conducted on the diffusion-triples proved that Al diffusion in sputtered NiCr is more rapid than that in sintered NiCr. Through the use of profile processing techniques, Al was shown to follow type B kinetics for grain boundary diffusion in sputtered NiCr. It also revealed that Y addition to sputtered NiCr further accelerates Al diffusion through a non-Fickian mechanism involving Al clustering.
The baseline fouling and corrosion behavior of ferrous alloys in a high temperature, high pressure, and an asphaltenic environment was also evaluated. Key insights were generated on the interplay between the thermochemical properties of the asphaltene, the environmental conditions, surface preparation of the alloys, and the chemistry of the deposits. X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy allowed for the first time to pinpoint mechanisms for high temperature model asphaltene deposition on ferrous alloys. Improving surface roughness alone was found to be a good strategy to mitigate asphaltenic fouling at lower temperatures where the asphaltene remains intact. However, at temperatures where reactive asphaltene decomposition products become present in solution, surface chemistry control becomes important. Specifically, a protective atomic layer deposition alumina chemistry on steels was found to significantly reduce asphaltenic fouling.
In order to evaluate whether a protective alumina chemistry could be generated on components with more complex geometries, low temperature pack cementation of ferrous alloys was conducted. Preliminary data did show an improvement in anti-fouling properties with both model asphaltenes in a static environment, as well as with crude oil in a hydrodynamic environment. However, XPS revealed a mixed alumina-hematite oxide on the surface that may be limiting the anti-fouling properties of these surfaces. Finally, new insights gained from developing low temperature pack cementation for ferrous alloys allowed for the modification of low thermal stability, functional metallic structures like Ni inverse opals. It resulted in a thermal stability enhancement by 500 oC, comparable to refractory metals in the same configuration. And also improved both the modulus and hardness of these structures.Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2021-05-01The student, Pralav Shetty, accepted the attached license on 2019-02-20 at 15:57.The student, Pralav Shetty, submitted this Dissertation for approval on 2019-02-20 at 16:17.This Dissertation was approved for publication on 2019-02-22 at 10:53.DSpace SAF Submission Ingestion Package generated from Vireo submission #13398 on 2019-08-22 at 16:19:59Made available in DSpace on 2019-08-23T20:44:32Z (GMT). No. of bitstreams: 3
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Structure Analysis Of Plant Lectin Domains
No full textLectins are multivalent carbohydrate binding proteins that specifically recognise diverse sugar structures and mediate a variety of biological processes, such as cell-cell and host-pathogen interactions, serum glycoprotein turnover and innate immune responses. Lectins have received considerable attention in recent years on account of their properties leading to wide use in research and biomedical applications. Seeds of leguminous plants are mainly rich sources of lectins, but lectins are also found in all classes and families of organisms. Legume lectins have similar tertiary structures, but exhibit a large variety of quaternary structures. The carbohydrate binding site in them is made up of four loops, the first three of which are highly conserved in all legume lectins. The fourth loop, which is variable, is implicated in conferring specificity. Legume lectins which share the same monosaccharide specificity often exhibit markedly different oligosaccharide specificities. This thesis primarily concerns with structure solution and analysis of lectins from the legume and β-prism II fold families using X-ray crystallography. Apart from having the property of specifically and reversibly binding to carbohydrates, lectins are also interesting models to study sequence-structure relationships, especially of how minor change in the sequence may bring about major changes in oligomerization and binding.
Chapter 1 gives an overview of different structural types of plant lectins and describes in detail, their carbohydrate binding features. The details of the various experimental procedures employed during the course of this research, are explained in Chapter 2.
Chapter 3 describes the crystal structure of a β-prism II fold lectin (RVL), from Remusatia vivipara, an epiphytic plant of traditional medicinal value, and analysis of its binding properties. This lectin was established to have distinct binding properties and has nematicidal activity against a root-knot nematode with the localization site identified as the high-mannose displaying gut-lining in the nematode. The crystal structure of RVL revealed a new quaternary association of this homodimeric lectin, different from those of reported β-prism II lectins. Functional studies on RVL showed that it fails to bind to simple mannose moieties yet showed agglutination with rabbit blood cells (which have mannose moieties on the surface) and some high mannose containing glycoproteins like mucin and asialofetuin. Further, ELISA and glycan array experiments indicated that RVL has high affinity to N-glycans like trimannose pentasaccharide such as in gp120, a capsid glycoprotein of HIV virus, necessary in virus-association with the host cell. The structural basis for this N-glycan binding was revealed through structure analysis and molecular modelling, and it was demonstrated that there are two distinct binding sites per monomer, making RVL a truly multivalent lectin. Evolutionary phylogeny revealed the divergence in the β-prism II fold proteins with regards to the number of sugar-binding regions per domain, oligomerization and specificity.
Chapter 4 deals with the structural studies on a galactose-specific legume lectin (DLL-II) from Dolichos lablab, a leguminous plant. The lectin was found to be a planar tetramer in the crystal structures of the native and ligand bound forms, as expected from our solution studies and phylogenetic analysis. The protein is a heterotetramer with subunits differing only in the presence or absence of a C-terminal helical region at the core of the tetramer. Due to the static disorder in all the crystals, the central helix could be oriented in either direction. Structure analysis of DLL-II proved to be an interesting endeavour as static disorder compounded with twinning in the crystal made the data processing and structure solution a challenging process. Subsequent structure and sequence alignments led to the identification of an adenine-binding pocket in the hydrophobic core of the tetramer. Based on this, DLL-II lectin was co-crystallized with adenine and the structure revealed the presence of adenine at the predicted binding site.
Chapter 5 describes the identification and analysis of potential plant lectins/lectin-like domains in the genome of Oryza sativa, using bioinformatics approaches. This project was initiated to study the occurrence of legume-lectin like domains (a predominant dicot feature) in O. sativa, which is a monocot. Later, a large scale genome analysis for all types of lectin domains was carried out through exhaustive PSI-BLAST, profile matching by HMMer, CDD and MulPSSM. The final validation was carried out by assessing the carbohydrate binding potential of the domain by examining the sugar binding sites. The primary interest in undertaking this work was to find the occurrence of association of these domains with other domains as in protein receptor kinases, where lectin is the receptor domain. Though primarily initiated as a bioinformatics project, further structural characterization was attempted by cloning, expression and purification of some of the annotated lectin proteins using prokaryotic expression systems. The protein expression was attained in reasonable amounts for a few of the annotated legume lectin homologs, however purification is yet to be achieved as the expressed proteins are insoluble.
A part of the results described in this thesis and the other related projects that the author was involved are reported in the following publications.
1) Purification, characterization and molecular cloning of a monocot mannose-binding lectin from Remusatia vivipara with nematicidal activity Bhat GG, Shetty KN, Nagre NN, Neekhra VV, Lingaraju S, Bhat RS, Inamdar SR, Suguna K, Swamy BM. 2010. Glycoconjugate J. 27(3):309-320
2) Modification of the sugar specificity of a plant lectin: structural studies on a point mutant of Erythrina corallodendron lectin Thamotharan S, Karthikeyan T, Kulkarni KA, Shetty KN, Surolia A, Vijayan M & Suguna K. 2011. Acta Crystallographica D 67(3):218-227
3) Crystal structure of a β-prism II lectin from Remusatia vivipara Shetty KN, Bhat GG, Inamdar SR, Swamy BM, Suguna K. 2012. Glycobiology 22(1): 56-69.
4) Structure of a galactose binding lectin from Dolichos lablab
Shetty KN, Lavanyalatha V, Rao RN, SivaKumar N & Suguna K (Under review)
5) Occurrence of lectin-like domains: Oryza sativa genome analysis. Shetty KN & Suguna K. (Manuscript in preparation
Chromium(III) and chromium(IV) bis(trimethylsilyl) amido complexes as ethylene polymerisation catalysts
No full textOxidation of Cr[N(SiMe3)(2)](2)(THF)(2) with iodine and dicumyl peroxide results in tetrahedral Cr(IV)Cr[N(SiMe3)(2)](2)I-2 and trigonal planar Cr(III) Cr[N(SiMe3)(2)](OCMe2Ph)(2), respectively; both complexes have been characterised by single-crystal X-ray diffraction, and both are active for ethylene polymerisation with alkylaluminium co-catalysts.PT: J; CR: AJJOU JAN, 1997, ORGANOMETALLICS, V16, P86 AJJOU JAN, 2000, J AM CHEM SOC, V122, P8968 ALONSO PJ, 2002, CHEM-EUR J, V8, P4056 BASI JS, 1971, J CHEM SOC A, P1433 BEAUDOIN MC, 2002, J MOL CATAL A-CHEM, V190, P159 BERNO P, 1994, ORGANOMETALLICS, V13, P1052 BLANCHARD H, 1988, J ORGANOMET CHEM, V341, P367 BOCHMANN M, 1980, J CHEM SOC DA, P1863 BRADLEY DC, 1972, J CHEM SOC CHEM COMM, P567 BRADLEY DC, 1976, ACCOUNTS CHEM RES, V9, P273 BRADLEY DC, 1978, INORG SYNTH, V18, P112 BRITOVSEK GJP, 1999, ANGEW CHEM INT EDIT, V38, P428 BURGER H, 1964, MONATSH, V95, P1099 CUMMINS CC, 1992, ANGEW CHEM INT EDIT, V31, P1501 CUMMINS CC, 1998, PROG INORG CHEM, V47, P685 DRYKACZ G, 1973, J AM CHEM SOC, V95, P4756 ELLER PG, 1977, COORDIN CHEM REV, V24, P1 FILIPPOU AC, 2002, EUR J INORG CHEM NOV, P2928 FILIPPOU AC, 2003, ANGEW CHEM INT EDIT, V42, P4486 FILIPPOU AC, 2003, ORGANOMETALLICS, V22, P3010 FIRMAN TK, 2001, J ORGANOMET CHEM, V635, P153 FRYZUK MD, 1995, ORGANOMETALLICS, V14, P5193 GIBSON VC, 1998, CHEM COMMUN 0821, P1651 GIBSON VC, 1999, J CHEM SOC DALT 0321, P827 GIBSON VC, 2000, J CHEM SOC DALTON, P1969 GIBSON VC, 2001, EUR J INORG CHEM JUL, P1895 GIBSON VC, 2002, J CHEM SOC DALTON, P4017 GIBSON VC, 2003, CHEM REV, V103, P283 HAGIHARA N, 1959, J AM CHEM SOC, V81, P3160 IKEDA H, 2001, MACROMOL CHEM PHYSIC, V202, P1806 IKEDA H, 2002, J ORGANOMET CHEM, V642, P156 KAYAL A, 2002, INORG CHEM, V41, P321 LAPLAZA CE, 1996, J AM CHEM SOC, V118, P8623 MESSERE R, 2000, EUR J INORG CHEM JUN, P1151 MINDIOLA DJ, 1998, ANGEW CHEM INT EDIT, V37, P945 MOWAT W, 1972, J CHEM SOC DA, P533 MOWAT W, 1973, J CHEM SOC DA, P770 ROBERTSON NJ, 2003, INORG CHEM, V42, P6876 SCHMID R, 2000, CAN J CHEM, V78, P265 SCHMID R, 2000, ORGANOMETALLICS, V19, P2756 SCHNEIDER S, 2001, INORG CHEM, V40, P4674 SCHULZKE C, 2002, ORGANOMETALLICS, V21, P3810 SCOTT SL, 2001, CHEM ENG SCI, V56, P4155 SEIDEL W, 1976, Z ANORG ALLG CHEM, V426, P150 SEIDEL W, 1976, Z ANORG ALLG CHEM, V426, P155 SMALL BL, 2004, MACROMOLECULES, V37, P4375 THEOPOLD KH, 1998, EUR J INORG CHEM JAN, P15 VANRENSBURG WJ, 2004, ORGANOMETALLICS, V23, P1207; NR: 48; TC: 3; J9: DALTON TRANS; PG: 3; GA: 865WTSource type: Electronic(1
Evaluation of gamma radiation-induced DNA damage in Aedes aegypti using the comet assay
No full textThe study was undertaken to evaluate gamma radiation-induced DNA damage in Aedes aegypti. The comet assay was employed to demonstrate the extent of DNA damage produced in adult male A. aegypti exposed to seven different doses of gamma radiation, ranging from 1 Gy to 50 Gy. DNA damage was measured as the percentage of comet tail DNA. A significant linear increase in DNA damage was observed in all samples; the extent of damage being proportional to the dose of gamma radiation the organism received, except in those treated with 1 Gy. The highest amount of DNA damage was noticed at 1 h postirradiation, which decreased gradually with time, that is, at 3, 6 and 12 h postirradiation. This may indicate repair of the damaged DNA and/or loss of heavily damaged cells as the postirradiation time increased. The comet assay serves as a sensitive and rapid technique to detect gamma radiation-induced DNA damage in A. aegypti. This could be used as a potential biomarker for environmental risk assessment. © 2017, © The Author(s) 2017
Design, Fabrication and Testing of a Micro-Malting Unit
No full textThis Dissertation / Report is the outcome of investigation carried out by the creator(s) / author(s) at the department/division of Central Food Technological Research Institute (CFTRI), Mysore mentioned below in this page
Seronegative spondyloarthropathies : a review : part I: classification and differential diagnosis
No full textThe seronegative spondyloarthropathies comprise a group of non-rheumatoid disorders with similar clinical, laboratory and genetic features. Recognition of new clinical features has supported the notion that they all form part of a clinical spectrum. These features and the classification of the seronegative spondyloarthropathies are discussed in the review.peer-reviewe
Optimization and Parametric Characterization of a Hydrodynamic Microvortex Chip for Single Cell Rotation
No full textabstract: Volumetric cell imaging using 3D optical Computed Tomography (cell CT) is advantageous for identification and characterization of cancer cells. Many diseases arise from genomic changes, some of which are manifest at the cellular level in cytostructural and protein expression (functional) features which can be resolved, captured and quantified in 3D far more sensitively and specifically than in traditional 2D microscopy. Live single cells were rotated about an axis perpendicular to the optical axis to facilitate data acquisition for functional live cell CT imaging. The goal of this thesis research was to optimize and characterize the microvortex rotation chip. Initial efforts concentrated on optimizing the microfabrication process in terms of time (6-8 hours v/s 12-16 hours), yield (100% v/s 40-60%) and ease of repeatability. This was done using a tilted exposure lithography technique, as opposed to the backside diffuser photolithography (BDPL) method used previously (Myers 2012) (Chang and Yoon 2004). The fabrication parameters for the earlier BDPL technique were also optimized so as to improve its reliability. A new, PDMS to PDMS demolding process (soft lithography) was implemented, greatly improving flexibility in terms of demolding and improving the yield to 100%, up from 20-40%. A new pump and flow sensor assembly was specified, tested, procured and set up, allowing for both pressure-control and flow-control (feedback-control) modes; all the while retaining the best features of a previous, purpose-built pump assembly. Pilot experiments were performed to obtain the flow rate regime required for cell rotation. These experiments also allowed for the determination of optimal trapezoidal neck widths (opening to the main flow channel) to be used for cell rotation characterization. The optimal optical trap forces were experimentally estimated in order to minimize the required optical power incident on the cell. Finally, the relationships between (main channel) flow rates and cell rotation rates were quantified for different trapezoidal chamber dimensions, and at predetermined constant values of laser trapping strengths, allowing for parametric characterization of the system.Dissertation/ThesisDemonstration of process flow in the microvortex chipCell rotation in a 50 microns wide (at the neck) trapezoidal chamber,at a flow rate of 95 microliters/min at approximately 0.25 rev/sCell rotation in a 70 microns wide (at the neck) trapezoidal chamber,at a flow rate of 7 microliters/min at approximately 0.125 rev/sM.S. Bioengineering 201
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