Colloidal silica gels as composite electrolytes: Rheology and ion transport

Walls, Howard Jerome North Carolina State University 2002 해외박사(DDOD)

This thesis applies aspects of colloidal science, rheology, and electrochemistry to address fundamental issues pertaining to the development of composite electrolytes with desirable conductivity, processability, and mechanical stability. Investigated are colloidal gels comprised of nano-sized fumed silica (SiO₂) with alkyl chains attached to its surface, end capped oligomers of polyethylene oxide, and lithium salts. The interactions between salt, silica, and solvating medium on ion transport characteristics, microstructure, and gel rheology are examined using nuclear magnetic resonance spectroscopy (NMR), electrophoretic NMR, ac impedance spectroscopy, and various rheological techniques. Electrophoretic NMR is used to determine the lithium transference number (T_Li, charge transport due to lithium cations), an important ion-transport characteristic that is difficult to measure. We independently measure the migration and, hence, the transference numbers of both the cation and anion, and show that they sum to unity, thus validating the technique. The effect of fumed silica concentration on various ion transport properties (T_Li, ionic conductivity, and diffusivities of ions) reveal minimal interaction between the charged species and the fumed silica network. The large, open structure of the silica network provide unimpeded ionic mobility, which in turn is found to be determined by the solvating oligomer and lithium salt. We find the gel elastic modulus (G<super>′</super>) and yield stress (τ_y) to exhibit power-law scaling relationships with filler volume fraction (&phis;): G<super>′</super> ∼ &phis;<super>n</super> and τ_y ∼ &phis;<super>p</super>. The addition of salt at a constant filler volume fraction shows moderate increases in G<super>′ </super>, τ_y, and critical strain (γ_c). We attribute the enhanced gel properties in the presence of salts to the solvating medium becoming more polar and making the alkyl chains attached to the fumed silica “stickier”, thereby increasing particle-particle interactions. We examine the presence of wall slip and yield stress in the colloidal gels using serrated and smooth test geometries. Tests conducted with smooth geometries exhibit wall-slip at high shear strains. Wall-slip is independent of filler and salt content. However, for salt-free solvents, increasing solvent viscosity reduces wall slip. The use of hydrophobic plates reduces slip, possibly due to the affinity between the plate and hydrophobic silica.

Relation in Hegel : the doctrine of relation in Hegel

Wall, Kevin Albert University Press of America 1983 국내박사

Zur Validit¨at der Erfassung schizophrener Basissymptome : Vergleich von FBF und BSABS

Wall, Eleonora Universi¨at Hamburg 1997 국내박사

IDENTIFICATION AND CHARACTERIZATION OF P450 2E1-LIKE ENZYME IN WINTER FLOUNDER (CYTOCHROME P450, PLEURONECTES AMERICANUS, CHLORZOXAZONE)

WALL, KRISTEN LEE THE UNIVERSITY OF CONNECTICUT 1997 해외박사

近代 個人主義에 대한 孟子思想의 意味

Wall Barbara 성균관대학교 대학원 2006 국내석사

近代 個人主義에 대한 孟子思想의 意味

THE CARESS OF FUTURITY : A STUDY OF THE ONTOLOGICAL STATUS OF ART AND LANGUAGE IN THE WORKS OF LEVINAS, BLANCHOT, AND AGAMBEN (EMMANUEL LEVINAS, MAURICE BLANCHOT, GIORGIOAGAMBEN)

WALL, THOMAS CARL University of Washington 1995 해외박사

The Relevance of Wolfhart Pannenberg’s Christology in the Context of the Ao Naga Concept of God

Lanuchuba Walling 서울기독대학교 신학전문대학원 2010 국내박사

This thesis is the outcome of the challenges posed by the traditional concept of God among the Ao Nagas. The impact of these differing worldviews have influence how God is conceived by the Ao Nagas. Therefore, in a Christian context where the concept of God is in conflict, Christology should be redefined. As the title suggests, one of the main subjects of this thesis is the Christology of Wolfhart Pannenberg. Thus, the second chapter is a study on the Christology of Wolfhart Pannenberg. His view that in Jesus Christ-and in him alone-the one God of the universe is present to save his creation from sin and decay, lies central in his theology. The resurrection of Jesus Christ reaffirms the infinity and the futurity of God. The Christ event is also an eschatological event as the eschatological destiny of humanity is embodied by Jesus, and the eschatological salvation springs from the event of resurrection. In the third chapter, the traditional concept of God is dealt with. There are certain attributes of God among the Ao Nagas. Out of these, Lijaba, one of the deities, has the strongest influence. His appearance among the people is still talked about. His deeds when he appeared to humans can be compared to the social dimensions of Jesus Christ. The inseparability of God and land is also evident in the Ao Naga Concept of God. This has led to the development of tribal theology which considers land as the center for the concept of God. The Ao Nagas also understand God as eternal, but the futuristic understanding of God is not clear. In the final chapter, solutions are sought from the Christological formulations of Pannenberg. The Ao Naga Christians should thus, retain the centrality of Jesus Christ and reaffirm the Christian Truth. The Ao Nagas should also regenerate hope by affirming that Jesus Christ is the power of the future.

Framing the enemy: Changing United States media images of China and the U.S.S.R. at the end of the Cold War

Holstein, Lisa Walls Indiana University 2002 해외박사(DDOD)

The Cold War was the overarching frame that shaped U.S. global relations for the last half of the 20<super>th</super> century and set the agenda for international news. This study investigates and critiques how unexamined assumptions carried in such frames are reproduced in “objective” news content. It is argued that frames in the news are more than artifacts of discourse and have real world effects on news agendas, structuring images and issues in ways that have substantive implications for public opinion and public policy. Frame analysis can illuminate how frames embedded in the production of international journalism naturalize the exclusion of potential alternative meanings, interpretations and understandings. Yet the operation of frames at many levels is little understood, while the question of appropriate methods for their analysis remains a contested arena in mass communication research. This study presents a synthetic theoretical approach that emphasizes the need to account for context and hegemony in the study of frames, raises questions about the non-agenda and alternatives for the social constructions of news, and suggests a bridge between different methodological approaches in the study of journalism. This method for systematic identification of constitutive elements of frames is illustrated by a qualitative content analysis of U.S. news magazines at a critical discourse moment, contrasting the framing of resurgent Chinese Communism (the turmoil at Tiananmen Square) with collapsing Soviet Communism (the fall of the Berlin Wall) during the transformative year 1989. Characteristics of professional newswork itself are found to be central to the reproduction of hegemonic frames in news content. The analysis method also leads to the identification of the shape of an emerging frame for international news grounded in presumptions about normality and modernity that was being constructed as U.S. journalists sought to define how news agendas would accommodate a post-Cold War world order. Fundamentally, the frame analysis of news content presented in this study is intended to advance the project of the theoretical development of framing studies as a productive direction for contributions to mass communication research.

Recombination and human demography

Wall, Jeffrey D The University of Chicago 2000 해외박사(DDOD)

Having a proper null model is crucial for population genetic modeling. This requires both accurate estimates of parameters, such as the population recombination parameter, and inference of a species' underlying demography. In this thesis, I explore ways of estimating the population recombination parameter from sequence data, and examine how different demographic models (<italic>e.g</italic>., ones including population structure and/or population size changes) affect patterns of sequence polymorphism. I then apply these results to current questions in human evolution.

Nucleation kinetics during homoepitaxial growth of titanium nitride(001) by reactive magnetron sputtering

Wall, Marcel Arlan University of Illinois at Urbana-Champaign 2003 해외박사(DDOD)

I use scanning tunneling microscopy to study the nucleation of homoepitaxial stoichiometric TiN layers grown on TiN(001) by ultrahigh vacuum reactive magnetron sputtering in pure N2. Nucleation lengths are measured using in-situ scanning tunneling microscopy as a function of temperature and nitrogen gas fraction fN2 in an Ar/N2 gas mixture on two-dimensional islands as well as on large open terraces. The characteristic island size Rc necessary to nucleate a new layer decreases continuously with fN2 , varying from 18.0 nm at Ts = 740°C with fN2 = 0.10 to 11.2 nm with fN2 = 1.00. At low growth temperatures, 500 ≤ Ts ≤ 865°C, nucleation is diffusion limited independent of fN2 and I extract a surface diffusion energy of 1.1 +/- 0.1 eV for TiN(001) growth with fN2 = 0.10 and 1.4 +/- 0.1 eV in pure N2. At higher temperatures, 865 < Ts ≤ 1010°C, nucleation is limited by the formation rate of stable clusters for which I obtain an activation energy of 2.4 +/- 0.2 eV with fN2 = 0.10 and 2.6 +/- 0.2 eV with fN2 = 1.00. Ab-initio calculations combined with my experimental results suggest that the primary diffusing adspecies during growth of TiN(001) in pure nitrogen are TiNx molecules with x = 2 and/or 3. I attribute the decrease in Es for growth at fN2 = 0.10 to a lower steady-state N coverage resulting in a decrease in x.