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Full-Text Articles in Engineering
Intracellular Localisation, Geno- And Cytotoxic Response Of Poly N-Isopropylacrylamide (Pnipam) Nanoparticles To Human Keratinocyte (Hacat) And Colon Cells (Sw 480), Pratap Naha, Kunal Bhattacharya, Tiziana Tenuta, Kenneth Dawson, Iseult Lynch, Amaya Gracia, Fiona Lyng, Hugh Byrne
Intracellular Localisation, Geno- And Cytotoxic Response Of Poly N-Isopropylacrylamide (Pnipam) Nanoparticles To Human Keratinocyte (Hacat) And Colon Cells (Sw 480), Pratap Naha, Kunal Bhattacharya, Tiziana Tenuta, Kenneth Dawson, Iseult Lynch, Amaya Gracia, Fiona Lyng, Hugh Byrne
Articles
PNIPAM nanoparticles, with and without a covalentlylinked fluorescent label, were prepared by a free radical polymerisation technique. The cyto and genotoxicity of PNIPAM nanoparticles were analysed in two representative mammalian cell lines, SW480, a colon, and HaCaT, a dermal cell line. Physical characterisation in terms of particle size and zeta potential of the PNIPAM nanoparticles was carried out both in aqueous solution and in the appropriate cell culture media. Uptake and colocalisation of fluorescently labelled PNIPAM nanoparticles was monitored in both cell lines using confocal laser scanning microscopy. Genotoxicity analysis using the Comet assay was performed in both cell lines …
Programmable Periodicity Of Quantum Dot Arrays With Dna Origami Nanotubes, Hieu Bui, Craig Onodera, Carson Kidwell, Yerpeng Tan, Elton Graugnard, Wan Kuang, Jeunghoon Lee, William B. Knowlton, Bernard Yurke, William L. Hughes
Programmable Periodicity Of Quantum Dot Arrays With Dna Origami Nanotubes, Hieu Bui, Craig Onodera, Carson Kidwell, Yerpeng Tan, Elton Graugnard, Wan Kuang, Jeunghoon Lee, William B. Knowlton, Bernard Yurke, William L. Hughes
Materials Science and Engineering Faculty Publications and Presentations
To fabricate quantum dot arrays with programmable periodicity, functionalized DNA origami nanotubes were developed. Selected DNA staple strands were biotin-labeled to form periodic binding sites for streptavidin-conjugated quantum dots. Successful formation of arrays with periods of 43 and 71 nm demonstrates precise, programmable, large-scale nanoparticle patterning; however, limitations in array periodicity were also observed. Statistical analysis of AFM images revealed evidence for steric hindrance or site bridging that limited the minimum array periodicity.
Experiments And Modelling Of Micro-Jet Assisted Fluidization Of Nanoparticles, J. Ruud Van Ommen, David M. King, Alan Weimer, Robert Pfeffer, Berend Van Wachem
Experiments And Modelling Of Micro-Jet Assisted Fluidization Of Nanoparticles, J. Ruud Van Ommen, David M. King, Alan Weimer, Robert Pfeffer, Berend Van Wachem
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
The fluidization of nanoparticle agglomerates can be largely improved by using downward pointing micronozzles, creating a high-velocity jet, as experimentally shown. By discrete particle simulations – treating the agglomerates as single particles – we show that the main reason is probably the reduction of the agglomerate size by agglomerate-agglomerate collisions.
Fluidization Of Nanopowders: Experiments, Modeling, And Applications, J. Ruud Van Ommen, Robert Pfeffer
Fluidization Of Nanopowders: Experiments, Modeling, And Applications, J. Ruud Van Ommen, Robert Pfeffer
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
Nanopowders are applied in a wide range of processes, and their use continues to increase. Fluidization is one of the best techniques available to disperse and process nanoparticles. However, nanoparticles cannot be fluidized individually; they fluidize as very porous agglomerates. Often, it is needed to apply an assisting method, such as vibration or microjets, to obtain proper fluidization. In this paper, we give a brief review of the developments in nanopowder fluidization.
A Reactive Molecular Dynamics Simulation Of The Silica-Water Interface, Joseph C. Fogarty, Hasan Metin Aktulga, Ananth Y. Grama, Adri C. T. Van Duin, Sagar A. Pandit
A Reactive Molecular Dynamics Simulation Of The Silica-Water Interface, Joseph C. Fogarty, Hasan Metin Aktulga, Ananth Y. Grama, Adri C. T. Van Duin, Sagar A. Pandit
PRISM: NNSA Center for Prediction of Reliability, Integrity and Survivability of Microsystems
We report our study of a silica-water interface using reactive molecular dynamics. This first-of-its-kind simulation achieves length and time scales required to investigate the detailed chemistry of the system. Our molecular dynamics approach is based on the ReaxFF force field of van Duin [J. Phys. Chem. A 107, 3803 (2003)]. The specific ReaxFF implementation (SERIALREAX) and force fields are first validated on structural properties of pure silica and water systems. Chemical reactions between reactive water and dangling bonds on a freshly cut silica surface are analyzed by studying changing chemical composition at the interface. In our simulations, reactions involving silanol …
Preparation Of Titanium Dioxide Nanoparticles From Electrocoagulated Sludge Using Sacrificial Titanium Electrodes, H K. Shon, S Phuntsho, S Vigneswaran, Jaya Kandasamy, Long Nghiem, G J. Kim, J B. Kim, Jin-Ho Kim
Preparation Of Titanium Dioxide Nanoparticles From Electrocoagulated Sludge Using Sacrificial Titanium Electrodes, H K. Shon, S Phuntsho, S Vigneswaran, Jaya Kandasamy, Long Nghiem, G J. Kim, J B. Kim, Jin-Ho Kim
Faculty of Engineering - Papers (Archive)
A comprehensive investigation of electrocoagulation using sacrificial titanium (Ti) electrodes in wastewater was carried out. The effects of specific process variables, such as initial pH, mixing, current density, initial organic loading, and ionic/electrolyte strength were first optimized to produce recyclable Ti-based sludge. The sludge was incinerated at 600 °C to produce functional TiO2 photocatalyst. X-ray diffraction analysis revealed that TiO2 produced at optimum electrocoagulation conditions was mostly anatase structure. The specific surface area of the synthesized TiO2 photocatalyst was higher than that of the commercially available and widely used Degussa P-25 TiO2. Furthermore, energy dispersive …
Far-Field Optical Nanoscopy Based On Continuous Wave Laser Stimulated Emission Depletion, C. Kuang, Wei Zhao, Guiren Wang
Far-Field Optical Nanoscopy Based On Continuous Wave Laser Stimulated Emission Depletion, C. Kuang, Wei Zhao, Guiren Wang
Faculty Publications
Stimulated emission depletion (STED) microscopy is one of the breakthrough technologies that belong to far-field optical microscopy and can achieve nanoscale spatial resolution. We demonstrate a far-field optical nanoscopy based on continuous wave lasers with different wavelengths, i.e., violet and green lasers for excitation and STED, respectively. Fluorescent dyes Coumarin 102 and Atto 390 are used for validating the depletion efficiency. Fluorescent nanoparticles are selected for characterizing the spatial resolution of the STED system. Linear scanning of the laser beams of the STED system along one line of a microscope slide, which is coated with the nanoparticles, indicates that a …
Microbial Reduction Of Uranium Under Iron- And Sulfate-Reducing Conditions: Effect Of Amended Goethite On Microbial Community Composition And Dynamics, H.S. Moon, L. Mcguinness, Ravi K. Kukkadapu, A.D. Peacock, John Komlos, L.J. Kerkhof, P.E. Long, Peter R. Jaffe
Microbial Reduction Of Uranium Under Iron- And Sulfate-Reducing Conditions: Effect Of Amended Goethite On Microbial Community Composition And Dynamics, H.S. Moon, L. Mcguinness, Ravi K. Kukkadapu, A.D. Peacock, John Komlos, L.J. Kerkhof, P.E. Long, Peter R. Jaffe
United States Department of Energy: Publications
There is a growing need for a better understanding of the biogeochemical dynamics involved in microbial U(VI) reduction due to an increasing interest in using biostimulation via electron donor addition as a means to remediate uranium contaminated sites. U (VI) reduction has been observed to be maximized during iron-reducing conditions and to decrease upon commencement of sulfate-reducing conditions. There are many unknowns regarding the impact of iron/sulfate biogeochemistry on U(VI) reduction. This includes Fe(III) availability as well as the microbial community changes, including the activity of iron-reducers during the uranium biostimulation period even after sulfate reduction becomes dominant. Column experiments …
Effects From Filtration, Capping Agents, And Presence/Absence Of Food On The Toxicity Of Silver Nanoparticles To Daphnia Magna, H. Joel Allen, Christopher A. Impellitteri, Dana A. Macke, J. Lee Heckman, Helen C. Poynton, James M. Lazorchak, Shekar Govindaswamy, Deborah L. Roose, Mallikarjuna N. Nadagouda
Effects From Filtration, Capping Agents, And Presence/Absence Of Food On The Toxicity Of Silver Nanoparticles To Daphnia Magna, H. Joel Allen, Christopher A. Impellitteri, Dana A. Macke, J. Lee Heckman, Helen C. Poynton, James M. Lazorchak, Shekar Govindaswamy, Deborah L. Roose, Mallikarjuna N. Nadagouda
United States Environmental Protection Agency: Publications
Relatively little is known about the behavior and toxicity of nanoparticles in the environment. Objectives of work presented here include establishing the toxicity of a variety of silver nanoparticles (AgNPs) to Daphnia magna neonates, assessing the applicability of a commonly used bioassay for testing AgNPs, and determining the advantages and disadvantages of multiple characterization techniques for AgNPs in simple aquatic systems. Daphnia magna were exposed to a silver nitrate solution and AgNPs suspensions including commercially available AgNPs (uncoated and coated), and laboratory-synthesized AgNPs (coated with coffee or citrate). The nanoparticle suspensions were analyzed for silver concentration (microwave acid digestions), size …
Synthesis, Structural Characterization And Magnetic Properties Of Iron Boride Nanoparticles With Or Without Silicon Dioxide Coating, Mislav Mustapic, Damir Pajic, Nikolina Novosel, Emil Babic, Kreso Zadro, Marina Cindric, Josip Horvat, Zeljko Skoko, Mirjana Bijelic, Andrey Shcherbakov
Synthesis, Structural Characterization And Magnetic Properties Of Iron Boride Nanoparticles With Or Without Silicon Dioxide Coating, Mislav Mustapic, Damir Pajic, Nikolina Novosel, Emil Babic, Kreso Zadro, Marina Cindric, Josip Horvat, Zeljko Skoko, Mirjana Bijelic, Andrey Shcherbakov
Faculty of Engineering - Papers (Archive)
Nanoparticles of iron boride (Fe2B, Fe2B coated in SiO2, FexCo2−xB coated in SiO2) were synthesized using the reduction of metal ions by sodium borohydride. X-ray diffraction confirms the amorphicity of the coated compounds and scanning electron microscope imaging revealed the nanoparticulated structure of all compounds. The splitting between zero-field-cooled and field-cooled temperature dependent magnetization curves point to the blocking of superparamagnetic particles magnetization. Magnetic hysteresis loops are however consistent with the combined effects of blocked superparamagnetic and ferromagnetic (multidomain) particles. The observed quite complex magnetic behaviour is in …
Mesoporous Tin Oxide As An Oxidation-Resistant Catalyst Support For Proton Exchange Membrane Fuel Cells, Peng Zhang, Sheng-Yang Huang, Branko N. Popov
Mesoporous Tin Oxide As An Oxidation-Resistant Catalyst Support For Proton Exchange Membrane Fuel Cells, Peng Zhang, Sheng-Yang Huang, Branko N. Popov
Faculty Publications
Mesoporous catalyst support based on tin oxide (SnO2) is synthesized with high surface area of 205 m2 g−1 and with narrow pore size distribution. Modified polyol method is used to deposit platinum on SnO2. The physical properties of the support and the SnO2-supported Pt catalyst (Pt/SnO2) are characterized by using the Brunauer, Emmett, and Teller method, X-ray diffraction, and transmission electron microscopy. The electrochemical stability and durability of the Pt/SnO2 catalyst are investigated by the accelerated stress tests proposed by the U.S. Department of Energy. Pt/SnO2 catalyst exhibits …