VictorJuiz/thesis huggingface dataset:
Characterization, Kinetics and Redox Properties of LaCr1-x NixO3 Perovskites: Implications for Combustion and Solid Oxide Fuel Cells

LaCr1−xNixO3 perovskite oxides (x = 0, 0.25, 0.50, 0.75, 1.00) were investigated as possible materials for combustion of exhaust gases and as a potential solid oxide fuel cell (Sore) anode. This involved the determination of surface cation composition, kinetics of methane oxidation, catalyst stability under reducing conditions (P(O 2) < 1.10−6 atm), and redox properties. <p> XPS investigation to obtain surface cation compositions showed that surface and bulk compositions are indistinguishable. The methane oxidation rate depended on catalyst composition, and the highest activity was measured with LaNiO 3. Ni-O-Ni ensembles in the nickel-containing materials are good candidates for the reactive species since a local defect can be formed without cation migration. A random population of B sites by Ni ions would produce a surface density of Ni-O-Ni ensembles proportional to x2 (x in LaCr 1−xNixO3), in agreement with the dependence found in this study. During transient methane reduction (0.21 kPa ≤ P(CH 4) ≤ 1.4 kPa and no gas phase oxygen), initial catalyst activities were comparable to rates in the presence of gas phase oxygen, indicating the same initial reaction pathways. The materials with high Cr (x ≥ 0.5) content are capable of preserving the perovskite lattice even after complete reduction of Ni3+ [special characters omitted] Ni2+ in methane or hydrogen and subsequent reoxidation in the oxygen/argon mixture. Oxygen mobility studies showed that at least three distinct oxygen pools exist in these catalysts at lower temperatures (50°–300°C): adsorbed CO2; easily accessed sites associated with Ni; less accessible sites that become involved at higher temperatures (≥300°C). LaCr1−xNixO3 materials have a better oxygen ion mobility than La(Sr)MnO3−δ perovskites and are comparable to (LaCa)(CoFe)O3−δ materials. LaCr0.75Ni0.25O3 oxygen ion diffusion coefficient at 300°C is 4.1010 cm 2/s. In summary: LaCr0.5Ni0.5O3 is a potential combustion catalyst due to its high hydrocarbon oxidation rate, good performance during upset conditions (oxygen lean atmosphere), and material stability to reduction/reoxidation cycles. LACr1−xNi xO3 materials are possible anodes for solid oxide fuel cells, because they provide a substantial increase in the number of active surface sites over standard anode materials.
The astronaut family and the schools

The focus of the study was a group of ten women who had recently come to Ontario from Hong Kong with their children. Their husbands remain in Hong Kong to maintain their businesses and visit their families two or three times a year. This phenomenon has been called "astronaut" family by sociologists. Some of the children in these "astronaut" families in my school have been having difficulty with English language acquisition and other academic subjects. Teachers and administrators have been asking why this should be so when it has been assumed that Chinese children are highly motivated and achievers. The mothers often do not speak English well and they are having to handle all aspects of family living by themselves in a new country with different expectations and values. This study was an attempt to understand the lives of the women in this situation, how they feel about the schools in Ontario and what their expectations are for their children. An open-ended questionnaire and a follow-up interview with three of the mothers were used to gain information about these issues and give the mothers an opportunity to express their feelings about living here. Teachers and principals in the schools the children attend were interviewed to investigate their perspective on the education of the children in "astronaut" families and the role of these Chinese mothers. The children of the three women in the follow-up were also interviewed. Recommendations were developed based on the results of the questionnaires and interviews proposing steps that schools and teacher training institutions could take in training teachers and administrators who must work with the children and mothers in "astronaut" and other immigrant families.
An efficient Newton-Krylov method for the Euler and Navier-Stokes equations

An efficient inexact-Newton-Krylov algorithm is presented for the computation of steady compressible aerodynamic flows on structured grids. The spatial discretization consists of a second-order centered-difference operator with the second and fourth-difference dissipation model of Jameson et al. The Baldwin-Lomax algebraic model is used for turbulent flows. The thin-layer Navier-Stokes equations are linearized using Newton's method. Preconditioned restarted GMRES in matrix-free form is used to solve the linear system arising at each Newton iteration. The preconditioner is formed using an incomplete factorization of an approximate-Jacobian matrix after applying a reordering technique. An optimization study is presented to obtain an efficient parameter-free solver for a wide range of flows. An inexact-Newton strategy that avoids oversolving is established. Comparison between different preconditioners of the incomplete-lower-upper factorization family is presented. The best performance/memory ratio was obtained for the Block-Fill ILU(2) preconditioner. A parametric optimization of the approximate-Jacobian used to produce well-conditioned LU factors is also shown. Different reordering techniques are considered; results show that the Reverse Cuthill-McKee is the most efficient technique. The algorithm has been successfully applied to a wide range of test cases which include inviscid, laminar, and turbulent aerodynamic flows. In all cases except one, convergence of the residual to 10-12 is achieved with a CPU cost equivalent to fewer than 1000 function evaluations. The sole exception is a low Mach number case where some form of local preconditioning is needed. Several other efficient implicit solvers have been applied to the same test cases, and the matrix-free inexact-Newton-GMRES algorithm is seen to be the fastest and most robust of the methods studied.
The mode of cell division and characterization of the ftsZ gene of Campylobacter jejuni ATCC 43431

Campylobacter jejuni is a frequent bacterial fecal isolate in humans with diarrhea in most parts of the world (Skirrow, 1994; Walker et al., 1986). This study aims to identify the mode of C. jejuni ATCC 43431 cell division and characterize its ftsZ gene, which is an essential cell division gene in Escherichia coli (Dai and Lutkenhaus, 1991). Transmission electron microscopy (TEM) of C. jejuni cultures reveal that the predominant mode of cell division in logarithmic (log) and stationary phase cultures is symmetrical and asymmetrical (forming coccoid or minicells) cell division, respectively. The molecular mechanisms which dictate the modes and regulation of cell division remain to be determined. As numerous studies have shown that ftsZ is essential and plays a key role in E. coli cell division, characterization of the C. jejuni homolog in this study is an important step in elucidating the molecular mechanisms of C. jejuni cell division. After screening several C. jejuni genomic libraries, the complete C. jejuni ftsZ gene was isolated on two Lambda Gem 11 recombinant clones. The entire coding and upstream putative regulatory sequences were determined. (Abstract shortened by UMI.)
The world as it is versus the world as it ought to be, liberal and communist ideals of distributive justice in relation to the realities of capitalism and actually existing socialism in the 20th century

This thesis analyses liberal and communist views of distributive justice and evaluates the normative claims of both in relation to the realities of capitalism and "actually existing socialism". The strengths and weaknesses of both types of societies are discussed. Liberalism and meritocracy will be critically analysed. The works of the liberal philosopher John Rawls will be examined followed by Carol Gould, who provides a socialist critique of his views. I will argue that communism is not just an ideal but a feasible system in the contemporary world. The communist tenet, "from each according to his abilities, to each according to his needs", will be explored by invoking and utilizing the concept of effort.
Approximations for saddlepoint densities of M-estimators

We examine the implications of using estimated cumulants in saddlepoint density function approximations. Much of the current literature on empirical saddlepoint methodology is concerned with the relative error of the density estimate. Our interest is not in the order of the relative error, since large cumulants may have an effect which outweighs the effect of the sample size. Steepest descents methodology can be used to express many density functions as asymptotic series in powers of 'n'-1/2 For many M-estimators, and other statistics, each term in the saddlepoint series can be expressed as series in powers of 'n'-1/2 . Thus, the leading terms in the overall series forms a density approximation. The saddlepoint density series is a function of cumulants. An estimated density can be determined by estimating the cumulants. Cumulants estimation can take many forms, in particular empirical estimation, or estimation with zero. Thus there are many possible density estimates. We show how steepest descents methodology can often be used to create a series, proportional to the saddlepoint approximation 'fSP'(' x'), for the difference between the true and estimated density. When the series exists, and the estimated cumulants are asymptotically Gaussian, <math> <f> <fen lp="par"><a><ac>f</ac><ac>&d4;</ac></a><fen lp="par">x<rp post="par"></fen> -f<fen lp="par">x<rp post="par"></fen><rp post="par"></fen></f> </math> is asymptotically Gaussian. This limiting distribution is not constant over all 'x'. We show how the expansion of <math> <f> <rad><rcd>n</rcd></rad><fen lp="par"><a><ac>f</ac><ac>&d4;</ac></a> <fen lp="par">x<rp post="par"></fen>-f<fen lp="par">x<rp post="par"></fen> <rp post="par"></fen></f> </math> can be used to assess various cumulant estimators. In particular, the series can be used to determine if a cumulant should be empirically estimated or estimated with zero. Conclusions are not independent of 'x'. However, if all higher order cumulants are known, the leading term in <math> <f> E<fen lp="par"><a><ac>f</ac><ac>&d4;</ac></a><fen lp="par">x; <g>k</g><inf>1</inf>&ldots;<g>k</g><inf>j-1</inf>,<a><ac><g>k</g> </ac><ac>&d4;</ac></a><inf>j</inf><rp post="par"></fen>-f<fen lp="par"> x<rp post="par"></fen><rp post="par"></fen><sup>2</sup></f> </math> is smaller than the leading term in <math> <f> E<fen lp="par"><a><ac>f</ac><ac>&d4;</ac></a><fen lp="par">x; <g>k</g><inf>1</inf>&ldots;<g>k</g><inf>j-1</inf>,0<rp post="par"></fen> -f<fen lp="par">x<rp post="par"></fen><rp post="par"></fen><sup> 2</sup></f> </math> if the coefficient of variation for the empirical cumulant is less than one. This conclusion is independent of 'x'0. We show there is often a point in the empirical cumulant sequence after which estimates should be omitted from an empirical saddlepoint density. The point depends on the empirical cumulant coefficient of variation sequence. Examples show the for M-estimators cumulant estimation should rarely exceed the fourth cumulant, often the Gaussian approximation is sufficient for smooth densities and small sample sizes.
Feminist intertextuality and the Bluebeard story

Feminist intertextual fictions reveal through negotiations with the Bluebeard fairy tale not only motivations for its continuing popularity but also a practical redefinition of what constitutes feminist intertextuality. The Bluebeard story metafictively illustrates two types of intertextuality: monologic (Bluebeard's plot) and dialogic (the heroine's plot revision). Feminist intertextual rewritings demonstrate that their revisionist focus is in fact on intertextuality itself; they are "meta-intertextual." Primary among the tenets of intertextuality theory revised through the Bluebeard intertext is "presupposition" and its implications for the reader. Feminist intertextual fictions reveal that intertextuality's presupposed reader is a monologic textual construct. Presupposition is the intertextual reader's Bluebeard. Following an extensive introduction, three chapters perform close readings organized around the concepts of presupposition as a textual haunting, the ' mise en abyme', and the detective hermeneutic, respectively. The first juxtaposes William Godwin's 'Caleb Williams' and Jane Austen's ' Northanger Abbey' to demonstrate Gothic metafictional treatment of presupposition. Chapter two considers Bluebeard's depiction as a death-artist and his uncanny 'mise en abyme' of the female reader in Bluebeard fictions by John Fowles, Peter Ackroyd, and Kurt Vonnegut, constrasting this with the reader's "escape artistry" in Angela Carter's ' The Magic Toyshop' and 'Nights at the Circus' and Gloria Naylor's' Linden Hills'. Third, the detective hermeneutic thematizes presupposition in the intertextual reading process. Casting the Bluebeard story as a mystery defamiliarizes presupposition in Margaret Atwood's ' The Robber Bride' and Emma Cave's 'Bluebeard's Room'. Detection is a thematized reading strategy in Atwood's "Bluebeard's Egg" and in Max Frisch's 'Bluebeard'. The enigma-solution model of presuppositional reading is dramatized in Donald Barthelme's "Bluebeard," and "Instructions for Navigating the Labyrinth" by Canadian Meira Cook. Contemporary appeal in the Bluebeard story as an intertext may derive from the fairy tale's own metafictional use of intertextuality and revisionism. Fictions reading the tale foreground the different strategies of Bluebeard and his reader, demonstrating feminist intertextual theory in practice. In contrast to intertextuality theory, the status and strategies of the female reader are of utmost importance to feminist intertextual fictions.
Analysis of ribonucleoprotein complexes involved in transcriptional antitermination

The stable association of the 'N' gene transcriptional antiterminator protein of bacteriophage lambda with transcribing RNA polymerase requires a 'nut' site ('boxA' + 'boxB ') in the nascent transcript, and the 'Escherichia coli' factors NusA, NusB, NusG and ribosomal protein S10. In this thesis, it is shown that N binds 'boxB' RNA and that the subsequent association of NusA with the N-'nut' site complex is facilitated by both boxA and 'boxB'. In the presence of N, NusA, and RNA polymerase, ribonucleoprotein complexes containing NusB, NusG, and S10 are assembled on nut RNA. The assembly of NusB, NusG, and S10 is impaired by mutations in nucleotides 2-7 of 'boxA'. The effects on assembly of mutations in 'boxA', 'boxB', NusA and RNA polymerase define weak protein-protein and protein-RNA interactions that contribute to the overall stability of the complex. Interaction of each component of the complex with two or more other components can explain the many observed cooperative binding associations in the DNA-independent assembly of a stable antitermination complex. A series of N fragments has been used to define regions of N that are important for its activity. The amino-terminal arginine-rich region of N (amino acids 1-22) was shown previously to recognize 'boxB' RNA; it is shown here that amino acids 34-47 of N bind NusA and are important for antitermination. The 'boxB'- and NusA-binding regions of N are sufficient to reverse the termination-enhancing effect of NusA, but insufficient to support a maximal level of antitermination. Instead, a region carboxy-terminal to the NusA-binding region can bind RNA polymerase directly and is also critical for antitermination. Antitermination at the ribosomal RNA operons of 'E. coli' is similar to N-mediated antitermination except that only 'boxA' RNA is required. A protein from a crude 'E. coli' extract was purified on the basis of its 'boxA'-binding activity. This protein was identified as ribosomal protein S1 and was shown to bind specifically to 'boxA' RNA. Although S1 competes with NusB and S10 for binding to 'boxA', it does not autonomously regulate antitermination ' in vitro'.
The role of the antennule inner ramus in mediating response to distant chemical information by female crayfish, Procambarus clarkii

The bifurcated antennules of decapod crustaceans are believed to be the most important organs used in long-distance chemoreception. Specific antennular rami were ablated to determine if female red-swamp crayfish (Procambarus clarkii) used the inner rami to locate food and social stimuli. Rami were not required for the initiation of searching behaviours over short distances, but were required over long-distances. Although all animals in all treatment groups were able to detect a food stimulus over long distances, only one-half of the animals possessing only the inner rami were able to locate it. These successful animals walked slower, and needed a longer search duration than did controls or other treatment groups. Crayfish with only inner rami experienced no such disadvantage when locating the source of a social stimulus, and were similar to other treatment groups in latency to search, search duration, meander ratio and average walking speed. These results demonstrate that the inner rami are used by female P. clarkii in the localisation of social stimuli.
Structural analysis in the footwall of the Uchi-English River subprovince boundary, Red Lake region, northwestern Ontario

Results of detailed structural mapping in two greenstone masses at Chase and Longlegged Lakes, near the Uchi-English River subprovince boundary, suggest that the late-stage, dextral Sydney Lake fault zone (SLFZ) could not have greatly affected the present structure. At Chase Lake, NW-SE striking lithological units and boudins would have been buckled had they been deformed by distributed dextral shear. Two tectonic scenarios account for the regional structure at Chase Lake. In scenario 1, an overturned anticline is refolded by a second WNW trending fold. In scenario 2, NW-SE ductile dislocations following the shore of Chase and Midway lakes produce the present lithologic pattern. The displacement history of the Uchi-English River subprovince boundary, particularly the dip-shear component, is poorly known. From geophysical modelling, the subprovince boundary is interpreted to dip gently 30$\sp\circ$S in the vicinity of the SLFZ. An accretion hypothesis for the Superior Province was tested by utilizing a new technique which determines the angular range of resolved shear strain within the footwall of the subprovince boundary. The local sense of shear strain on the footwall is dextral reverse or sinistral reverse in the Chase and Longlegged Lake areas. The varying sense of boundary-parallel displacement suggests that strike shear is insignificant on the scale of several kilometres.
Dynamics of soil-plant relationships after afforestation of sodic soils with Prosopis juliflora, Swartz DC, in Haryana, India

Large tracts of once productive farmlands in the Indo-Gangetic plains of India have been degraded by intensive cropping and over-irrigation. This has resulted in soil salinization and alkalization. Soil productivity may be restored by afforestation with salt-tolerant tree species. Temporal patterns of biomass accumulation, understorey vegetation development, soil fertility and moisture, tree growth and the nutritional status of plant tissues were studied under greenhouse and field conditions in an age sequence of ' Prosopis juliflora' planted 0-, 5-, 7-, and 30-years ago on similar sodic soils in Haryana, India. The objective was to develop an understanding of plant-soil relationships driving protracted ecological processes involved in the rejuvenation of sodic soils under afforestation, and to address the issues of sustainable management for these forest plantations. The structural (species composition) and functional (nutrient content and biomass) diversity of plantation systems increased with age. The growth of trees altered the microclimate and improved soil moisture status, infiltration capacity, organic C, total N, available P and exchangeable Ca, Mg and K levels. Decreases in pH, electrical conductivity, and exchangeable Na levels were also observed. The ameliorating effects of trees on soil increased with tree occupancy. Soil dynamics reflected a three phase restoration sequence characterized by nominal soil changes during tree establishment phase (0-5 years), marked and rapid changes in a short transition phase that was associated with canopy closure (5-7 years), and gradual stabilization of soil properties in the fallow enrichment phase (7-30 years). The ameliorative mechanisms which contributed to soil remediation were categorized into two parallel sets of major processes: sodicity alleviation associated with salt leaching, and fertility restoration driven by organic matter addition through litter fall and nutrient cycling. The former was typical of the transition phase while the latter characterized the fallow enrichment phase. Effective phytoremediation was confirmed by pot trials assessing the yield and nutritional response of an agricultural crop (wheat) reared on fallow, plantation and farm soils. Contrary to previous studies, results demonstrate that lengthy rotation (>30 years) systems are necessary to sustain future productivity of these plantation ecosystems.
Interaction of Class I major histocompatibility molecules with the transporter associated with antigen processing (TAP) and the molecular chaperone calnexin

Class I major histocompatibility molecules consist of a ~45 kDa transmembrane glycoprotein termed the heavy chain, a ~12 kDa soluble protein termed ß 2-microglobulin, and a peptide ligand of 8 to 10 residues. These three subunits assemble in the endoplasmic reticulum (ER) and then are transported to the cell surface. Cytotoxic T lymphocytes of the immune system specifically recognize and eliminate cells, bearing class I molecules containing peptides derived from foreign (e.g., viral) proteins. The bulk of class I-binding peptides are generated in the cytosol by the proteasome and then are transported across the ER membrane via a peptide transporter termed TAP. Within the ER, the molecular chaperone calnexin facilitates folding of class I heavy chains and their assembly with ß2m and retains class I assembly intermediates until assembly of the ternary complex with peptide is complete. This thesis documents the discovery, characterization, and functional consequences of an interaction between the TAP and class I molecules in mouse cells. Newly assembled class I H chain-ß2m heterodimers but not free H chains associate with TAP in a ternary complex that also contains calnexin. Dissociation of both TAP and calnexin from class I molecules occurs in parallel with the movement of class I molecules out of the ER. In permeabilized cells, binding of peptide to class I molecules leads to disruption of the TAP-class I association but not the calnexin-class I association. When peptide supply is limited through inhibition of proteasome activities, the TAP-class I association is prolonged and class I movement out of the ER is slowed. Furthermore, mutant class I molecules assembling without interacting with TAP appear to obtain peptides that dissociate rapidly at the cell surface causing lower cell surface class I levels and less efficient antigen presentation to T cells relative to their wild type counterparts. These findings suggest a model whereby the TAP-class I interaction facilitates loading of stably-bound peptides onto class I molecules by providing a high local concentration of peptides and, also, together with calnexin, by retaining class I molecules until they obtain optimal, stably-bound peptides.