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Artificial Olfactory System For Multi-Component Analysis Of Gas Mixtures., Alexander Aleksandrovich Larin 2017 University of Louisville

Artificial Olfactory System For Multi-Component Analysis Of Gas Mixtures., Alexander Aleksandrovich Larin

Electronic Theses and Dissertations

Gas analysis is an important part of our world and gas sensing technology is becoming more essential for various aspects of our life. A novel approach for gas mixture analysis by using portable gas chromatography in combination with an array of highly integrated and selective metal oxide (MOX) sensors has been studied. We developed a system with small size (7 x 13 x 16 inches), low power consumption (~10 W) and absence of special carrier gases designed for portable field analysis (assuming apriori calibration). Low ppb and even sub-ppb level of detection for some VOCs was achieved during the analysis ...


Analysis Of Primary Stripper Foils At The Spallation Neutron Source By An Electron Beam Foil Test Stand, Eric Paul Barrowclough 2017 University of Tennessee, Knoxville

Analysis Of Primary Stripper Foils At The Spallation Neutron Source By An Electron Beam Foil Test Stand, Eric Paul Barrowclough

Doctoral Dissertations

Diamond films are used at the Spallation Neutron Source (SNS) as the primary charge exchange foils (i.e., stripper foils) of the accelerated 1 GeV (Gigaelectron volts) hydride ions. The most common type of film used is a nanocrystalline diamond film, typically 17 mm x 45 mm (millimeter) with an aerial density of 350 μg/cm2 (microgram per square centimeter). The diamond film is deposited on a corrugated silicon substrate using plasma-assisted chemical vapor deposition. After the growth of the diamond film, 30 mm of the silicon substrate is etched away, leaving a freestanding diamond foil with a silicon ...


Development Of High-Performing Polydimethylsiloxane-Based Membranes For Carbon Dioxide Separation, Tao Hong 2017 University of Tennessee, Knoxville

Development Of High-Performing Polydimethylsiloxane-Based Membranes For Carbon Dioxide Separation, Tao Hong

Doctoral Dissertations

Membrane separation is highlighted as one of the most promising approaches to mitigate the excessive CO2 [carbon dioxide] emission, due to its significant reduction of energy cost compared with many conventional separation techniques. Unfortunately, the separation performance of current membranes does not meet the practical CO2/N2 [nitrogen] separation requirements. And due to the huge volume of industrial flue gas, membranes with exceptionally high permeability are needed for practical reasons.

Currently, the separation mechanism of most polymeric membranes is based on size-sieving. However, this method is not sufficient for CO2/N2 separations due to the ...


A Molecular Debye-Hückel Theory Of Solvation In Polar Fluids: An Extension Of The Born Model, Tiejun Xiao, Xueyu Song 2017 Guizhou Education University

A Molecular Debye-Hückel Theory Of Solvation In Polar Fluids: An Extension Of The Born Model, Tiejun Xiao, Xueyu Song

Ames Laboratory Accepted Manuscripts

A dielectric response theory of solvation beyond the conventional Born model for polar fluids is presented. The dielectric response of a polar fluid is described by a Born response mode and a linear combination of Debye-Hückel-like response modes that capture the nonlocal response of polar fluids. The Born mode is characterized by a bulk dielectric constant, while a Debye-Hückel mode is characterized by its corresponding Debye screening length. Both the bulk dielectric constant and the Debye screening lengths are determined from the bulk dielectric function of the polar fluid. The linear combination coefficients of the response modes are evaluated in ...


Vertically-Aligned Mn(Oh)2 Nanosheet Films For Flexible All-Solid-State Electrochemical Supercapacitors, Ziyuan Yang, Jiangfeng Gong, Chunmei Tang, Weihua Zhu, Zhaojun Cheng, Jinghua Jiang, Aibin Ma, Qingping Ding 2017 Hohai University

Vertically-Aligned Mn(Oh)2 Nanosheet Films For Flexible All-Solid-State Electrochemical Supercapacitors, Ziyuan Yang, Jiangfeng Gong, Chunmei Tang, Weihua Zhu, Zhaojun Cheng, Jinghua Jiang, Aibin Ma, Qingping Ding

Ames Laboratory Accepted Manuscripts

The arrangement of the electrode materials is a significant contributor for constructing high performance supercapacitor. Here, vertically-aligned Mn(OH)2 nanosheet thin films were synthesized by cathodic electrodeposition technique on flexible Au coated polyethylene terephthalate substrates. Morphologies, microstructures, chemical compositions and valence state of the nanosheet films were characterized systematically. It shows that the nanosheets arranged vertically to the substrate, forming a porous nanowall structures and creating large open framework, which greatly facilitate the adsorption or diffusion of electrolyte ions for faradaic redox reaction. Electrochemical tests of the films show the specific capacitance as high as 240.2 F g ...


Intermetallic Structures With Atomic Precision For Selective Hydrogenation Of Nitroarenes, Yuchen Pei, Zhiyuan Qi, Tian Wei Goh, Lin-Lin Wang, Raghu V. Maligal-Ganesh, Heather L. Macmurdo, Shiran Zhang, Chaoxian Xiao, Xinle Li, Franklin (Feng) Tao, Duane D. Johnson, Wenyu Huang 2017 Iowa State University and Ames Laboratory

Intermetallic Structures With Atomic Precision For Selective Hydrogenation Of Nitroarenes, Yuchen Pei, Zhiyuan Qi, Tian Wei Goh, Lin-Lin Wang, Raghu V. Maligal-Ganesh, Heather L. Macmurdo, Shiran Zhang, Chaoxian Xiao, Xinle Li, Franklin (Feng) Tao, Duane D. Johnson, Wenyu Huang

Ames Laboratory Accepted Manuscripts

Bridging the structure-properties relationship of bimetallic catalysts is essential for the rational design of heterogeneous catalysts. Different from random alloys, intermetallic compounds (IMCs) present atomically-ordered structures, which is advantageous for catalytic mechanism studies. We used Pt-based intermetallic nanoparticles (iNPs), individually encapsulated in mesoporous silica shells, as catalysts for the hydrogenation of nitroarenes to functionalized anilines. With the capping-free nature and ordered atomic structure, PtSn iNPs show >99% selectivity to hydrogenate the nitro group of 3-nitrostyrene albeit with a lower activity, in contrast to Pt3Sn iNPs and Pt NPs. The geometric structure of PtSn iNPs in eliminating Pt threefold sites hampers ...


Investigating Scalable Manufacturing Of High-Conductivity Wires And Coatings From Ultra-Long Carbon Nanotubes, Pouria Khanbolouki 2017 University of New Mexico - Main Campus

Investigating Scalable Manufacturing Of High-Conductivity Wires And Coatings From Ultra-Long Carbon Nanotubes, Pouria Khanbolouki

Mechanical Engineering ETDs

Carbon nanotubes (CNTs) are a promising candidate for next generation of electrical wirings and electromagnetic interference (EMI) shielding materials due to their exceptional mechanical and electrical properties. Wires and coatings from ultralong nanotubes that are highly crystalline, well-aligned and densely packed can achieve this goal. High-performance CNT conductors will be relatively lightweight and resistant to harsh conditions and therefore can potentially replace current conductors in many industries including aerospace, automotive, gas and oil.

This thesis investigates a new manufacturing approach, based on conventional solution coating and wire drawing methods, to fabricate high conductivity wires and coatings from ultra-long carbon nanotubes ...


Gamma-Radiation Induced Corrosion Of Alloy 800, Mojtaba Momeni 2017 The University of Western Ontario

Gamma-Radiation Induced Corrosion Of Alloy 800, Mojtaba Momeni

Electronic Thesis and Dissertation Repository

This thesis presents a newly developed mechanism and predictive model for the corrosion of Alloy 800. The Fe-Cr-Ni Alloy (Incoloy 800) is mainly used for steam generator (SG) tubing in CANDU and PWR reactors and is a candidate material for the proposed Canadian Supercritical Water Reactor (SCWR) in which it will be exposed to extreme conditions of high radiation flux and large temperature gradients. The influence of gamma radiation and water chemistry conditions on the corrosion behaviour of Alloy 800 are studied in this work. Ionizing radiation creates reducing (•eaq, •H, •O2-) and oxidizing radiolysis (•OH, H2 ...


Superconductivity At Т≈200 K In Bismuth Cuprates Synthesized Using Solar Energy, J. Chigvinadze, Juana Acrivos, S. Ashimov, D. Gulamova, G. Donadze 2017 Tbilisi State University

Superconductivity At Т≈200 K In Bismuth Cuprates Synthesized Using Solar Energy, J. Chigvinadze, Juana Acrivos, S. Ashimov, D. Gulamova, G. Donadze

Faculty Publications, Chemistry

When investigating low-frequency (0.1 Hz) oscillations of multiphase high-temperature cuprate superconductors (HTCS) Bi1,7Pb0,3Sr2Ca(n-1)CunOy (n=2-30), a wide attenuation peak (ΔT~100 К) with a maximum at Т≈200 К was detected. This peak was particularly pronounced in field cooling (FC) experiments, i.e. after abrupt cooling of the sample in the external magnetic field at the temperature Т<Тс with subsequent slow warming up to room temperature with invariance of the applied field. The attenuation peak height depended on the preliminaryorientation (before cooling) of the samples θ in the measured permanent magnetic field Н. On the one hand, it is well known that, after the FC procedure and subsequent slow warming up, at the temperatures close to the critical temperature Тс, the attenuation peak associated with “melting” of the Abrikosov frozen vortex structure and its disappearance at Т >Тс is detected in monophase samples. At the same time, in most multiphase bismuth HTCS samples, synthesized using solar energy and superfast quenching of the melt, the attenuation peak with the maximum at Т≈200 К was ...


Superconductivity At Т≈200 K In Bismuth Cuprates Synthesized Using Solar Energy, J. G. Chigvinadze, Juana Vivó Acrivos, S. M. Ashimov, D. D. Gulamova, G. J. Donadze 2017 Tbilisi State University

Superconductivity At Т≈200 K In Bismuth Cuprates Synthesized Using Solar Energy, J. G. Chigvinadze, Juana Vivó Acrivos, S. M. Ashimov, D. D. Gulamova, G. J. Donadze

Juana Vivó Acrivos

When investigating low-frequency (0.1 Hz) oscillations of multiphase high-temperature cuprate superconductors (HTCS) Bi1,7Pb0,3Sr2Ca(n-1)CunOy (n=2-30), a wide attenuation peak (ΔT~100 К) with a maximum at Т≈200 К was detected. This peak was particularly pronounced in field cooling (FC) experiments, i.e. after abrupt cooling of the sample in the external magnetic field at the temperature Т<Тс with subsequent slow warming up to room temperature with invariance of the applied field. The attenuation peak height depended on the preliminary
orientation (before cooling) of the samples θ in the measured permanent magnetic field Н ...


Differentiating The Impact Of Nitrogen Chemical States On Optical Properties Of Nitrogen-Doped Graphene Quantum Dots, Timothy Pillar-Little, Doo Young Kim 2017 University of Kentucky

Differentiating The Impact Of Nitrogen Chemical States On Optical Properties Of Nitrogen-Doped Graphene Quantum Dots, Timothy Pillar-Little, Doo Young Kim

Chemistry Faculty Publications

The optical properties of top-down synthesized oxidized graphene quantum dots (ox-GQDs) and nitrogen-incorporating graphene quantum dots (N-GQDs) along a range of hydrothermal treatment temperatures were observed. By controlling the hydrothermal treatment temperature, different chemical states of nitrogen atoms were incorporated into GQDs. Below 150 °C, edge-terminating amines and amides dominated the nitrogen content of N-GQDs. Above 150 °C, nitrogen was primarily present in the forms of pyridinic, pyrrolic and quaternary N. In addition to the absorbance and emission profiles of ox-GQDs and N-GQDs, pH-dependent emission spectra were collected to probe chemical states of nitrogen atoms and investigate the relationship between ...


Measuring Long-Range 13c–13c Correlations On A Surface Under Natural Abundance Using Dynamic Nuclear Polarization-Enhanced Solid-State Nuclear Magnetic Resonance, Takeshi Kobayashi, Igor I. Slowing, Marek Pruski 2017 Ames Laboratory

Measuring Long-Range 13c–13c Correlations On A Surface Under Natural Abundance Using Dynamic Nuclear Polarization-Enhanced Solid-State Nuclear Magnetic Resonance, Takeshi Kobayashi, Igor I. Slowing, Marek Pruski

Ames Laboratory Accepted Manuscripts

We report that spatial (<1 >nm) proximity between different molecules in solid bulk materials and, for the first time, different moieties on the surface of a catalyst, can be established without isotope enrichment by means of homonuclear CHHC solid-state nuclear magnetic resonance experiment. This 13C–13C correlation measurement, which hitherto was not possible for natural-abundance solids, was enabled by the use of dynamic nuclear polarization. Importantly, it allows the study of long-range correlations in a variety of materials with high resolution.


Nucleation And Growth Kinetics For Intercalated Islands During Deposition On Layered Materials With Isolated Point-Like Surface Defects, Yong Han, Ann Lii-Rosales, Y. Zhou, C.-J. Wang, M. Kim, Michael C. Tringides, Cai-Zhuang Wang, Patricia A. Thiel, James W. Evans 2017 Iowa State University and Ames Laboratory

Nucleation And Growth Kinetics For Intercalated Islands During Deposition On Layered Materials With Isolated Point-Like Surface Defects, Yong Han, Ann Lii-Rosales, Y. Zhou, C.-J. Wang, M. Kim, Michael C. Tringides, Cai-Zhuang Wang, Patricia A. Thiel, James W. Evans

Ames Laboratory Accepted Manuscripts

Theory and stochastic lattice-gas modeling is developed for the formation of intercalated metal islands in the gallery between the top layer and the underlying layer at the surface of layered materials. Our model for this process involves deposition of atoms, some fraction of which then enter the gallery through well-separated point-like defects in the top layer. Subsequently, these atoms diffuse within the subsurface gallery leading to nucleation and growth of intercalated islands nearby the defect point source. For the case of a single point defect, continuum diffusion equation analysis provides insight into the nucleation kinetics. However, complementary tailored lattice-gas modeling ...


Dynamic Studies Of Guest Molecules In Metal-Organic Frameworks And Zeolites Via Solid-State Nuclear Magnetic Resonance, Bowei Wu 2017 The University of Western Ontario

Dynamic Studies Of Guest Molecules In Metal-Organic Frameworks And Zeolites Via Solid-State Nuclear Magnetic Resonance, Bowei Wu

Electronic Thesis and Dissertation Repository

Metal-organic frameworks (MOFs) are synthetic compounds with crystalline microporous structures, consisting of metal centres joined by organic linkers. Zeolites are a class of crystalline porous materials featuring negatively charged aluminosilicate frameworks and charge-balancing cations.

In this work, solid-state nuclear magnetic resonance (SSNMR) is used to probe guest molecule locations and dynamics in MOFs and zeolites, yielding detailed informations of guest motion within these porous materials

Chapter 2 describes SSNMR dynamic studies of 13CO2, 13CO and C2D4 adsorption behaviour in the α - zinc formate MOF, [Zn3(HCOO)6], which were performed at variable temperatures ...


Hybrid Polymer Electrolyte For Lithium-Oxygen Battery Application, Amir Chamaani 2017 Amir Chamaani

Hybrid Polymer Electrolyte For Lithium-Oxygen Battery Application, Amir Chamaani

FIU Electronic Theses and Dissertations

The transition from fossil fuels to renewable resources has created more demand for energy storage devices. Lithium-oxygen (Li-O2) batteries have attracted much attention due to their high theoretical energy densities. They, however, are still in their infancy and several fundamental challenges remain to be addressed. Advanced analytical techniques have revealed that all components of a Li-O2 battery undergo undesirable degradation during discharge/charge cycling, contributing to reduced cyclability. Despite many attempts to minimize the anode and cathode degradation, the electrolyte remains as the leading cause for rapid capacity fading and poor cyclability in Li-O2 batteries. In this ...


Nano/Submicro-Structured Iron Cobalt Oxides Based Materials For Energy Storage Application, Hongyan Gao 2017 Western Kentucky University

Nano/Submicro-Structured Iron Cobalt Oxides Based Materials For Energy Storage Application, Hongyan Gao

Masters Theses & Specialist Projects

Supercapacitors, as promising energy storage devices, have been of interest for their long lifespan compared to secondary batteries, high capacitance and excellent reliability compared to conventional dielectric capacitors. Transition metal oxides can be applied as the electrode materials for pseudocapacitors and offer a much higher specific capacitance. Co3O4 is one of the most investigated transition metal oxides for supercapacitor. Besides simple monometallic oxides, bimetallic transition oxides have recently drawn growing attention in electrochemical energy storage. They present many unique properties such as achievable oxidation states, high electrical conductivities because of the coexistence of two different cations in a single crystal ...


A Benign Synthesis Of Alane By The Composition-Controlled Mechanochemical Reaction Of Sodium Hydride And Aluminum Chloride, Ihor Z. Hlova, Jennifer Goldston, Shalbh Gupta, Takeshi Kobayashi, Marek Pruski, Vitalij K. Pecharsky 2017 Iowa State University

A Benign Synthesis Of Alane By The Composition-Controlled Mechanochemical Reaction Of Sodium Hydride And Aluminum Chloride, Ihor Z. Hlova, Jennifer Goldston, Shalbh Gupta, Takeshi Kobayashi, Marek Pruski, Vitalij K. Pecharsky

Ames Laboratory Accepted Manuscripts

Solid-state mechanochemical synthesis of alane (AlH3) starting from sodium hydride (NaH) and aluminum chloride (AlCl3) has been achieved at room temperature. The transformation pathway of this solid-state reaction was controlled by a step-wise addition of AlCl3 to the initial reaction mixture that contained sodium hydride in excess of stoichiometric amount. As in the case of previously investigated LiH-AlCl3 system, complete selectivity was achieved whereby formation of unwanted elemental aluminum was fully suppressed, and AlH3 was obtained in quantitative yield. Reaction progress during each step was investigated by means of solid-state NMR and powder X-ray diffraction ...


Manipulation Of Dirac Cones In Intercalated Epitaxial Graphene, Minsung Kim, Michael C. Tringides, Matthew T. Hershberger, Shen Chen, Myron Hupalo, Patricia A. Thiel, Cai-Zhuang Wang, Kai-Ming Ho 2017 Iowa State University and Ames Laboratory

Manipulation Of Dirac Cones In Intercalated Epitaxial Graphene, Minsung Kim, Michael C. Tringides, Matthew T. Hershberger, Shen Chen, Myron Hupalo, Patricia A. Thiel, Cai-Zhuang Wang, Kai-Ming Ho

Ames Laboratory Accepted Manuscripts

Graphene is an intriguing material in view of its unique Dirac quasi-particles, and the manipulation of its electronic structure is important in material design and applications. Here, we theoretically investigate the electronic band structure of epitaxial graphene on SiC with intercalation of rare earth metal ions (e.g., Yb and Dy) using first-principles calculations. The intercalation can be used to control the coupling of the constituent components (buffer layer, graphene, and substrate), resulting in strong modification of the graphene band structure. It is demonstrated that the metal-intercalated epitaxial graphene has tunable band structures by controlling the energies of Dirac cones ...


Distinct Ice Patterns On Solid Surfaces With Various Wettabilities, Jie Liu, Chongqin Zhu, Kai Liu, Ying Jiang, Yanlin Song, Joseph S. Francisco, Xiao Cheng Zeng, Jianjun Wang 2017 Chinese Academy of Sciences

Distinct Ice Patterns On Solid Surfaces With Various Wettabilities, Jie Liu, Chongqin Zhu, Kai Liu, Ying Jiang, Yanlin Song, Joseph S. Francisco, Xiao Cheng Zeng, Jianjun Wang

Xiao Cheng Zeng Publications

No relationship has been established between surface wettability and ice growth patterns, although ice often forms on top of solid surfaces. Here, we report experimental observations obtained using a process specially designed to avoid the influence of nucleation and describe the wettability-dependent ice morphology on solid surfaces under atmospheric conditions and the discovery of two growth modes of ice crystals: along-surface and off-surface growth modes. Using atomistic molecular dynamics simulation analysis, we show that these distinct ice growth phenomena are attributable to the presence (or absence) of bilayer ice on solid surfaces with different wettability; that is, the formation of ...


Fabrication And Characterization Of Cuins₂ And Cuinse₂ Light-Absorbing Thin Films For Use In Solar Cells, Amy R. Tapley 2017 The University of Western Ontario

Fabrication And Characterization Of Cuins₂ And Cuinse₂ Light-Absorbing Thin Films For Use In Solar Cells, Amy R. Tapley

Electronic Thesis and Dissertation Repository

Solar energy is free and globally abundant and harnessed cost-effectively, it has the potential to be the world’s main source of energy. CuInGa(S,Se)2 solar cells have a very high efficiency of 20 %. However, gallium is a rare and expensive element. We have decided to work on its alternative CuInSe2 (CISe) and CuInS2 (CIS) by removing gallium or both gallium and selenium. The p-type CISe or CIS light-absorbing semiconducting layer is crucial for this type of solar cell. Preparation methods for CIS and CISe films were developed to reduce the costs and enhance the photoelectrochemical ...


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