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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
131

Validation of the DFAQ-CU Among an Illicit Substance Using Population

Sullivan, Thalia P., Kromash, Rachelle, Mitchell, Hannah G., Ginley, Meredith K. 18 March 2021 (has links)
With high rates of cannabis use in college students and increasing legalization of cannabis, psychometrically sound scales of cannabis consumption remain a high research priority. The Daily Sessions, Frequency, Age of Onset, and Quantity of Cannabis Use Inventory (DFAQ-CU; Cuttler & Spradlin, 2017) assesses daily sessions, frequency, age of onset, and quantity of marijuana, concentrates, and edibles consumed. Preliminary psychometric properties have been established in a population of college students using cannabis legally. The current study aims to evaluate the psychometric properties of the DFAQ-CU in college students using cannabis illicitly. Participants (N=114) were 18- to 58-years-old (M=21.25). They completed the DFAQ-CU, Drug Use Disorders Identification Test (DUDIT), and Buss Perry Aggression Questionnaire (BPAQ). Analyses were performed using the original factor structures. The factor analysis will be replicated once the full sample has been obtained (~400 by 02/2021). Cronbach's alphas ranged from.32 to.92, with some factors showing stronger reliability (e.g., frequency) than others (e.g., daily sessions). Bivariate correlations indicated daily sessions (r(54)=.32, p=.02), frequency (r(53)=.50, p<.001), marijuana quantity (r(78)=.32, p=.004), and edible (r(25)=.54, p=.006) factors demonstrated high convergent validity with the DUDIT total score. The age of onset and concentrate quantity factors did not. All factors were significantly divergent from the BPAQ. Overall, the original six-factor scale appears to have a poor fit within a college student population with illicit use. Notably, the concentrate quantity and daily sessions factors have poor internal consistency and convergent validity. These will be further explored upon completion of data collection.
132

CORROSION PROTECTION OF COPPER IN OILY MEDIA: MICROSCOPIC MECHANISMS

Biswas, Avidipto 16 August 2013 (has links)
No description available.
133

Equilibrium and Kinetic Behavior of the y/β Interphase Boundary in Cu-Zn. Alloys

Stephens, Donald 12 1900 (has links)
<P> The equilibrium behavior of the boundaries separating the a and y crystalline phases in the copper zinc alloy system is investigated by measuring the magnitude, the relative anisotropy and the temperature dependence of the interfacial energies. A model, consistent with the interfacial energetics, is proposed and supported by observations of misfit dislocations at the boundary. The migration kinetics of the y/β interface are determined for both dendritic and polyhedral morphologies and the atomic mechanisms of growth are inferred from the. internally faulted ordered y precipitates. </p> / Thesis / Doctor of Philosophy (PhD)
134

Application of UV-Vis Spectroscopy to the Monitoring, Characterization and Analysis of Chemical Equilibria of Copper Etching Baths

Lambert, Alexander S. 08 1900 (has links)
The continuously increasing demand for innovation in the miniaturization of microelectronics has driven the need for ever more precise fabrication strategies for device packaging, especially for printed circuit boards (PCBs). Subtractive copper etching is a fundamental step in the fabrication process, requiring very precise control of etch rate and etch factor. Changes in the etching chemical equilibrium have significant effects on etching behavior, and CuCl2 / HCl etching baths are typically monitored with several parameters including oxidation-reduction potential, conductivity, and specific gravity. However, the etch rate and etch factor can be difficult to control even under strict engineering controls of those monitoring parameters. The mechanism of acidic cupric chloride etching, regeneration and recovery is complex, and the current monitoring strategies can have difficulty controlling the interlocking chemical equilibria. A complimentary tool, thin-film UV-Vis spectroscopy, can be utilized to improve the current monitoring strategies, as UV-Vis is capable of identifying and predicting etching behavior that the current standard methodologies have difficulty predicting. Furthermore, as a chemically-sensitive probe, UV-Vis can investigate the complex changes to the chemical equilibrium and speciation of the etch bath, and can contribute overall to significant improvements in the control of the copper etching system in order to meet the demands of next-level design strategies.
135

Characterization of the Metal Binding Properties of De Novo Designed Coiled Coil Metalloproteins

Zhu, Xianchun 10 March 2009 (has links)
No description available.
136

Comparative Study of Alternative Fuel Icing Inhibitor Additive Properties and Chemical Analysis of Metal Speciation in Aviation Fuels

Taylor, Kevin Brian 12 August 2010 (has links)
No description available.
137

Electroless Deposition of Copper and Copper-Manganese Alloy for Application in Interconnect Metallization

Yu, Lu 12 June 2014 (has links)
No description available.
138

Infrared Processed Copper-Tungsten Carbide Composites

Deshpande, Pranav Kishore 16 September 2002 (has links)
No description available.
139

Silver(I) and Copper(I) Complexes from Homoleptic to Heteroleptic: Synthesis, Structure and Characterization

Almotawa, Ruaa Mohammed 12 1900 (has links)
A plethora of novel scientific phenomena and practical applications, such as solid-state molecular solar cells and other optoelectronic devices for energy harvesting and lighting technologies, have catalyzed us to synthesize novel compounds with tunable properties. Synthetic routes, single crystal structures, and spectral and materials properties are described. Reactions of Ag(I) and Cu(I) precursors with various types of ligands -- including the azolates, diimines, and diiphosphines -- lead to the corresponding complexes in high yield. Varying the metal ions, ligands, synthetic methods, solvents, and/or stoichiometric ratio can change the properties including the molecular geometry or packing structure, reactivity, photophysical and photochemical properties, semiconducting behavior, and/or porosity of the functional coordination polymers obtained. For solar cells purposes, the absorption energy can be extended from the ultraviolet (UV) region, through the entire visible (Vis) region, onto a significant portion of the near-infrared (NIR) portion of the solar spectrum with high absorption coefficients due to the infinite conjugation of Cu(I) with diimine ligands. Twenty-eight crystal structures were obtained by conventional crystal growth methods from organic solvents, whereas their bulk product syntheses also included "green chemistry" approaches that precluded the use of hazardous organic solvents. The resulting products are characterized by powder x-ray diffraction (PXRD), Fourier transform infrared (FTIR), nuclear magnetic resonance (NMR), UV/Vis/NIR absorption/diffuse reflectance/photoluminescence spectroscopies, and thermogravimetric analysis (TGA). Regarding the scientific phenomena investigated, the highlighting work in this dissertation is the discovery of novel bonding/photophysical/optoelectronic properties of the following materials: a black absorber with absorption from 200- 900 nm, a very stable compound with a bright green luminescence obtained by a solventless reaction, and a novel coordination polymer showing uncommon interaction of Ag(I) with three different types of diimine ligands simultaneously.
140

Resistive Switching in Porous Low-k Dielectrics

Ali, Rizwan 05 June 2018 (has links)
Integrating nanometer-sized pores into low-k ILD films is one of the approaches to lower the RC signal delay and thus help sustain the continued scaling of microelectronic devices. While increasing porosity of porous dielectrics lowers the dielectric constant (k), it also creates many reliability and implementation issues. One of the problems is the little understood metal ion diffusion and drift in porous media. Here, we present a rigorous simulation method of Cu diffusion based on Master equation with elementary jump probabilities within the contiguous dielectric film, along the pore boundary, from the dielectric matrix to the pore boundary, and from the pore boundary to the matrix material. In view of the diffusional jump distance being as large as 2 nm, the nano-pores being on a similar length scale, and the film thickness being only a few tens of nanometers, the conventional diffusion equation in differential equation form is grossly inadequate and elementary jump frequencies are required for a proper description of the Cu diffusion in porous dielectric. The present atomistic approach allows a consistent implementation of Cu ion drift in electric field by lowering and raising of the diffusion barriers along the field direction. This will help understand the behavior of Cu interconnects under thermal or electric stress at an atomistic level. Another approach to lower the increasing RC delays is to bring memory and logic closer by integrating memory in the BEOL. Resistive RAM is one such memory is not transistor based and thus, does not require a silicon substrate. Thus, it offers the possibility of integration directly into the back-end reducing memory to logic distance from 1000s of µm to a 10s of nm. This 3D integration also allows for increased density as well. However, one barrier in the implementation of RRAM in the back end is the use of expensive as well as non-BEOL native material in conventional Cu/TaOx/Pt resistive devices. In this thesis, we present our research about functionality of RRAM with porous low-k dielectrics (which are a candidate for CMOS ILD), and through the similar elementary jump simulations, discuss the impact of porosity in dielectrics on the functionality of RRAM. Lastly, we present a cheaper replacement for Pt as the counter electrode in RRAM and show that it functions as good as Pt. This work addresses following three areas: 1. Modeling of diffusion in porous dielectrics through elementary jump based simulation. The model is based on random walk theory of elementary particle jumps. Initially, qualitative simulations are conducted without actual parameters. It is shown that Cu diffusion in porous dielectrics decreases quasi-linearly with porosity. Furthermore, it is shown that morphology of the pores may have a greater effect on diffusivity compared to porosity. The simulations are then calibrated with parameters, and the result is shown to yield a similar diffusivity times as actual process time. 2. Modeling of Cu ions drift in porous dielectrics under electric stress. First, the model is explained, and then qualitative simulation results are presented for porous dielectrics with varied porosities and morphologies. 3. Research to find a suitable replacement for Pt as the counter electrode in RRAM devices. The research methodology is discussed and a much cheaper Rh is selected as the potential replacement for Pt. Successful functionality of Rh based resistive devices is presented. / Master of Science / As electronic devices are being scaled for integrating more functions and higher computation, the internal delays are increasing, which may become a bottleneck in performance. To resolve this issue of internal delay, new materials are being proposed to replace the conventional materials to make the chip. One promising material like that are the porous dielectrics, to replace the conventional dielectrics used to manufacture electronic chips. The introduction of ‘air pores’ inside the dielectric used in chips may improve the delay, but it leads to several thermal and electrical reliability concerns. In this thesis, we argue that using differential equations to simulate effects on the nano-scale to explore such reliability issues is insufficient, and a simulation method based on individual atom/ion movement should be used to describe it. Here we provide a simulation model to explain the diffusivity of copper under thermal stress, as well as movement of Cu ions during electric stress in porous dielectrics, using our particle movement based simulation model, and prove that it delivers correct results. Secondly, the delay is especially significant for processor to memory communication. Thus, integrating memory close to processor is another method to reduce the delay. Resistive RAM (RRAM) is one such novel RAM technology that can be integrated close to processor. However due to usage of non-native as well as expensive materials, RRAM has not been commercially integrated close to processor. In this thesis, we also present a functioning RRAM using cheaper materials, as well as materials that are native to present electronics.

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