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Efficient multi-exciton emission from quantum dots.

Description: The fundamental spontaneous emission rate an emitter can be modified by its photonic environment. By enhancing the spontaneous emission rate, there is a possibility of extracting multi-exciton energies through radiative decay. In this report, we explore using high Q and small volume cavities to enhance the spontaneous emission rate. We observed greater than 50 folds enhancement in the spontaneous emission from photonic crystal waveguide or microcavity using close-packed monolayer of PbS quantum… more
Date: September 1, 2010
Creator: Luk, Ting Shan
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Student Support for EIPBN 2010 Conference

Description: The 54th International Conference on Electron, Ion and Photon Beam Technology and Nanofabrication, 2010, held at the Egan Convention Center and Hilton in Anchorage, Alaska, June 1 to 4, 2010 was a great success in large part because financial support allowed robust participation from students. The conference brought together 444 engineers and scientists from industries and universities from all over the world to discuss recent progress and future trends. Among the emerging technologies that are… more
Date: March 11, 2011
Creator: Farrow, Reginald C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Final Report. DOE Computational Nanoscience Project DE-FG02-03ER46096: Integrated Multiscale Modeling of Molecular Computing Devices

Description: The document is the final report of the DOE Computational Nanoscience Project DE-FG02-03ER46096: Integrated Multiscale Modeling of Molecular Computing Devices. It included references to 62 publications that were supported by the grant.
Date: November 15, 2009
Creator: Cummings, Peter
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Synthesis of silicon and germanium nanowires.

Description: The vapor-liquid-solid growth process for synthesis of group-IV semiconducting nanowires using silane, germane, disilane and digermane precursor gases has been investigated. The nanowire growth process combines in situ gold seed formation by vapor deposition on atomically clean silicon (111) surfaces, in situ growth from the gaseous precursor(s), and real-time monitoring of nanowire growth as a function of temperature and pressure by a novel optical reflectometry technique. A significant depend… more
Date: November 1, 2007
Creator: Clement, Teresa J. (Arizona State University) & Hsu, Julia W. P.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Plasma Synthesis of Nanoparticles for Nanocomposite Energy Applications

Description: The nanocomposite energy applications for plasma reactor produced nanoparticles are reviewed. Nanoparticles are commonly defined as particles less than 100 nm in diameter. Due to this small size, nanoparticles have a high surface-to-volume ratio. This increases the surface energy compared to the bulk material. The high surface-to-volume ratio and size effects (quantum effects) give nanoparticles distinctive chemical, electronic, optical, magnetic and mechanical properties from those of the bulk… more
Date: September 1, 2008
Creator: Kong, Peter C. & Kawczak, Alex W.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Mesoscale Interfacial Dynamics in Magnetoelectric Nanocomposites

Description: Theory and modeling of chessboard-like self-assembling of vertically aligned columnar nanostructures in films has been developed. By means of modeling and three-dimensional computational simulations, we proposed a novel self-assembly process that can produce good chessboard nanostructure architectures through a pseudo-spinodal decomposition of an epitaxial film under optimal thermodynamic and crystallographic conditions (appropriate choice of the temperature, composition of the film, and crysta… more
Date: August 6, 2009
Creator: Khachaturyan, Armen G.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Final Report on Kokes Awards for the 20th North American Catalysis Society Meeting

Description: This Final Report describes how the Kokes Awards program was carried out for the 2007 meeting with regard to selection of students and disbursement of funds received from DOE and other sources. The objective of the Richard J. Kokes Travel Award program of the American Catalysis Society is to encourage graduate students to attend and participate meaningfully in the biennial North American Catalysis Society Meeting.
Date: January 1, 2008
Creator: Wong, Michael S.
Item Type: Refine your search to only Text
Partner: UNT Libraries Government Documents Department
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DOE A9024 Final Report Functional and Nanoscale Materials Systems: Frontier Programs of Science at the Frederick Seitz Materials Research Laboratory

Description: The scientific programs of the FSMRL supported under the DOE A9024 Grant consisted of four interdisciplinary research clusters, as described. The clusters were led by Professors Tai Chiang (Physics), Jeffrey Moore (Chemistry), Paul Goldbart (Physics), and Steven Granick (Materials Science and Engineering). The completed work followed a dominant theme--Nanoscale Materials Systems--and emphasized studies of complex phenomena involving surfaces, interfaces, complex materials, dynamics, energetics,… more
Date: March 24, 2009
Creator: Lewis, Jennifer A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Characterization and modeling of thermal diffusion and aggregation in nanofluids.

Description: Fluids with higher thermal conductivities are sought for fluidic cooling systems in applications including microprocessors and high-power lasers. By adding high thermal conductivity nanoscale metal and metal oxide particles to a fluid the thermal conductivity of the fluid is enhanced. While particle aggregates play a central role in recent models for the thermal conductivity of nanofluids, the effect of particle diffusion in a temperature field on the aggregation and transport has yet to be stu… more
Date: May 1, 2010
Creator: Gharagozloo, Patricia E. & Goodson, Kenneth E. (Stanford University, Stanford, CA)
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Inert Gas Buffered Milling and Particle Size Separation of μ­m-Scale Superconducting Precursor Powders: Final Report

Description: The project developed an aerosol system for the met milling and particle size separation of the precursor powders used in fabrication of powder-in-tube superconductors. The work builds upon the results of a previous SBIR-funded development that proved the basic principles of the virtual impactor (VI) technology and its efficacy for the powders of interest. The new project extended that work in three respects: it integrated provisions for recirculating the aerosol flow using inert gas to avoid c… more
Date: June 20, 2008
Creator: McIntyre, P. & Seshadri, S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Laser Interactions in Nanomaterials Synthesis

Description: Laser interactions with materials have unique advantages to explore the rapid synthesis, processing, and in situ characterization of high quality and novel nanoparticles, nanotubes and nanowires. For example, laser vaporization of solids into background gases provides a wide range of processing conditions for the formation of nanomaterials by both catalyst-free and catalyst-assisted growth processes. Laser interactions with the growing nanomaterials provide remote in situ characterization of th… more
Date: January 1, 2010
Creator: Geohegan, David B.; Puretzky, Alexander A.; Rouleau, Christopher M.; Jackson, Jeremy Joseph; Eres, Gyula; Xiao, Kai et al.
Item Type: Refine your search to only Book
Partner: UNT Libraries Government Documents Department
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Advanced atom chips with two metal layers.

Description: A design concept, device layout, and monolithic microfabrication processing sequence have been developed for a dual-metal layer atom chip for next-generation positional control of ultracold ensembles of trapped atoms. Atom chips are intriguing systems for precision metrology and quantum information that use ultracold atoms on microfabricated chips. Using magnetic fields generated by current carrying wires, atoms are confined via the Zeeman effect and controllably positioned near optical resonat… more
Date: December 1, 2010
Creator: Stevens, James E.; Blain, Matthew Glenn; Benito, Francisco M. & Biedermann, Grant
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Deliquescence and efflorescence of small particles: Unifying perspectives from nucleation theory

Description: We examine size dependent deliquescence/efflorescence phase transformation for particles down to several nanometers in size. A thin layer criterion (TLC) is introduced to define a deliquescence relative humidity (DRH) for small particles. The usual bulk deliquescence conditions are recovered in the limit of large dry particle size. Nano-size particles are shown to deliquesce to metastable states via a nucleation process at relative humidity just below the DRH. The nucleation barrier is located … more
Date: February 23, 2009
Creator: McGraw,R. & Lewis, E.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Resolving fundamental limits of adhesive bonding in microfabrication.

Description: As electronic and optical components reach the micro- and nanoscales, efficient assembly and packaging require the use of adhesive bonds. This work focuses on resolving several fundamental issues in the transition from macro- to micro- to nanobonding. A primary issue is that, as bondline thicknesses decrease, knowledge of the stability and dewetting dynamics of thin adhesive films is important to obtain robust, void-free adhesive bonds. While researchers have studied dewetting dynamics of thin … more
Date: April 1, 2004
Creator: Hall, Jessica S.; Frischknecht, Amalie Lucile; Emerson, John Allen; Adkins, Douglas Ray; Kent, Michael Stuart; Read, Douglas H. et al.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

DOE/BES/NSET annual report on growth of metal and semiconductor nanostructures using localized photocatalysts.

Description: Our overall goal is to understand and develop a novel light-driven approach to the controlled growth of unique metal and semiconductor nanostructures and nanomaterials. In this photochemical process, bio-inspired porphyrin-based photocatalysts reduce metal salts in aqueous solutions at ambient temperatures to provide metal nucleation and growth centers. Photocatalyst molecules are pre-positioned at the nanoscale to control the location and morphology of the metal nanostructures grown. Self-asse… more
Date: October 1, 2003
Creator: Haddad, Raid Edward; Brinker, C. Jeffrey; Shelnutt, John Allen; Yang, Yi; Nuttall, H. Eric; Watt, Richard K. et al.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Review and assessment of nanofluid technology for transportation and other applications.

Description: This report provides a literature review on the research and development work contributing to the current status of nanofluid technology for heat transfer applications in industrial processes. Nanofluid technology is a relatively new field, and as such, the supporting studies are not extensive. Specifically, the experimental results and theoretical predictions regarding the enhancement of the thermal conductivity and convective heat transfer of nanofluids relative to conventional heat transfer … more
Date: May 31, 2007
Creator: Yu, W.; France, D. M.; Choi, S. U. S.; Routbort, J. L. & Systems, Energy
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Final LDRD report : science-based solutions to achieve high-performance deep-UV laser diodes.

Description: We present the results of a three year LDRD project that has focused on overcoming major materials roadblocks to achieving AlGaN-based deep-UV laser diodes. We describe our growth approach to achieving AlGaN templates with greater than ten times reduction of threading dislocations which resulted in greater than seven times enhancement of AlGaN quantum well photoluminescence and 15 times increase in electroluminescence from LED test structures. We describe the application of deep-level optical s… more
Date: December 1, 2011
Creator: Armstrong, Andrew M.; Miller, Mary A.; Crawford, Mary Hagerott; Alessi, Leonard J.; Smith, Michael L.; Henry, Tanya A. et al.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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A Nanocrystal Sensor for Luminescence Detection of Cellular Forces

Description: Quantum dots have been used as bright fluorescent tags with high photostability to probe numerous biological systems. In this work we present the tetrapod quantum dot as a dynamic, next-generation nanocrystal probe that fluorescently reports cellular forces with spatial and temporal resolution. Its small size and colloidal state suggest that the tetrapod may be further developed as a tool to measure cellular forces in vivo and with macromolecular spatial resolution.
Date: September 29, 2011
Creator: Choi, Charina; Chou, Jonathan; Lutker, Katie; Werb, Zena & Alivisatos, Paul
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Quantitative tunneling spectroscopy of nanocrystals

Description: The proposed goals of this collaborative work were to systematically characterize the electronic structure and dynamics of 3-dimensional metal and semiconducting nanocrystals using scanning tunneling microscopy/spectroscopy (STM/STS) and ballistic electron emission spectroscopy (BEES). This report describes progress in the spectroscopic work and in the development of methods for creating and characterizing gold nanocrystals. During the grant period, substantial effort also was devoted to the de… more
Date: May 25, 2007
Creator: First, Phillip N; Whetten, Robert L & Schaaff, T Gregory
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Measurement of electron-hole friction in an n-doped GaAs/AlGaAs quantum well using optical transient-grating spectroscopy

Description: We use phase-resolved transient grating spectroscopy to measure the drift and diffusion of electron-hole density waves in a semiconductor quantum well. The unique aspects of this optical probe allow us to determine the frictional force between a two-dimensional Fermi liquid of electrons and a dilute gas of holes. Knowledge of electron-hole friction enables prediction of ambipolar dynamics in high-mobility electron systems.
Date: April 26, 2011
Creator: Yang, Luyi; Koralek, J. D.; Orenstein, J.; Tibbetts, D. R.; Reno, J. L. & Lilly, M. P.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Nanoscale phosphorus atom arrays created using STM for the fabrication of a silicon based quantum computer.

Description: Quantum computers offer the promise of formidable computational power for certain tasks. Of the various possible physical implementations of such a device, silicon based architectures are attractive for their scalability and ease of integration with existing silicon technology. These designs use either the electron or nuclear spin state of single donor atoms to store quantum information. Here we describe a strategy to fabricate an array of single phosphorus atoms in silicon for the construction… more
Date: January 1, 2001
Creator: O'Brien, Jeremy L.; Schofield, Steven R.; Simmons, Michelle Y.; Clark, Robert G.; Dzurak, Andrew S.; Curson, Neil J. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Strain-dependent photoluminescence behavior in three geometries of CdSe/CdS nanocrystals

Description: In recent years, a new generation of quantum confined colloidal semiconductor structures has emerged, with more complex shapes than simple quantum dots1, 2. These include nanorods3 and tetrapods4. Beyond shape, it is also now possible to spatially vary the electron and hole potentials within these nanoparticles by varying the composition. Examples of these new structures include seeded dots, rods, and tetrapods, which contain a CdSe core embedded within a CdS shell5, 6. These structures may hav… more
Date: May 26, 2009
Creator: Choi, Charina L; Koski, Kristie J; Sivasankar, Sanjeevi & Alivisatos, A. Paul
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Design and Synthesis of Mixed Oxides Nanoparticles for Biofuel Applications

Description: The work in this dissertation presents the synthesis of two mixed metal oxides for biofuel applications and NMR characterization of silica materials. In the chapter 2, high catalytic efficiency of calcium silicate is synthesized for transesterfication of soybean oil to biodisels. Chapter 3 describes the synthesis of a new Rh based catalyst on mesoporous manganese oxides. The new catalyst is found to have higher activity and selectivity towards ethanol. Chapter 4 demonstrates the applications of… more
Date: May 15, 2010
Creator: Chen, Senniang
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries Government Documents Department
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