acase@tulane.edu

acase@tulane.edu

acase@tulane.edu

This dissertation examines the concept that well defined hosts can be effectively used for controlling product distribution in photochemical reactions. Spatially confined cavities provided by zeolites and water-soluble synthetic organic hosts such as octa acid and dendrimers are explored as reaction media Chapter one provides an introduction to water soluble well defined supramolecular hosts and reasoning for why they were considered. Several highlights in supramolecular fields on water soluble host-guest systems from photochemical perspective are addressed Chapter two concentrates on efforts to control excited state chemistry and physics of organic molecules through the use of hydrophobic cavity provided by an octa acid host. Aromatic guest molecules of various sizes have been included in the host and their photophysical behavior was studied. Octa acid host was shown to be an effective medium for conducting photochemical reactions in water Chapter three presents photochemical reactions carried out in hydrophobic cavities provided by phenolic dendrimers. Host's hydrophobicity is probed through fluorescence of pyrene. Organized media could control the product distributions by influencing the reaction at any or all stages. Examples of these are discussed in this chapter Chapter four presents introduction to asymmetric photoreactions in various media. General introduction about structure and properties of zeolites are addressed Chapter five discusses the asymmetric induction during photocyclisation of tropolone ethers within faujasite Y zeolites. Tropolone ethers undergo a 4-pi electrocyclization resulting in chiral products. Enantio and diastereo selectivity of the products was examined with chiral inductor and chiral auxiliary approach respectively. Density functional calculations have been used to understand the reasons for the high chiral induction observed experimentally and the role of cations in influencing the stereochemical outcome of the reaction Chapter six discusses the diastereoselectivity in the photorearrangement of 3,3-dimethyl-4-oxo-3,4-dihydro-naphthalene-1-carboxylic acid and 3,3,5-trimethyl-4-oxo-cyclohexa-1,5-dienecarboxylic acid derivatives within zeolites. A cation dependent diastereomeric switch was observed with 3,3,5-trimethyl-4-oxo-cyclohexa-1,5-dienecarboxylic acid derivatives Chapter seven concentrates on understanding alkali metal ion-organic molecule interaction through computations. Computational studies were performed to support the experimental results on regio/stereoselective photoreactions within zeolites. Theoretical methods such as HF, B3LYP in Titan and Gaussian 98 suite of programs were used in this regard / acase@tulane.edu

acase@tulane.edu

acase@tulane.edu

acase@tulane.edu

Bovine haversian femora were assumed to possess transversely isotropic material symmetry and the elastic properties of this tissue were determined from tests on machined specimens (taken from the cortex of femoral mid-sections) using two different testing techniques; namely, ultrasonic and standard (quasistatic) test machine methods Quasistatic machine testing consisted of performing uniaxial tension and simple torsion tests at a strain rate of approximately 3.5 x 10('-4)(s('-1)). Tensile specimens were tested while having an axial and a diametral extensometer attached concurrently to record axial strain and diametral change in their gage region. Ultrasonic testing consisted of measuring the velocity of longitudinal and transverse waves propagating in various directions in a 5mm bone cube. This technique utilized two transducers located on opposite sides of the specimen to transmit (at a resonance frequency of 2.25 MHz) and receive a continuous ultrasonic sine wave The test data were examined to develop empirical correlations between the quasistatic (test machine) values and ultrasonic measurements. Correlations were also examined for quasistatic elastic properties and the density and mineral content of bone. The results indicate that adequate estimates of the Young's moduli can be made from linear first order regression equations on the appropriate longitudinal velocity of ultrasound. Poisson's ratio can be adequately estimated from linear regression equation involving density. However, adequate estimates of the two independent moduli of rigidity can only be made using linear regression equations on three variables: wave speed, density, and mineral content The stress-strain curves produced during mechanical testing had regions that were slightly nonlinear. These curves also exhibited a sizeable amount of residual (anelastic) strain which was completely recovered in a fairly short period of time (less than thirty seconds). The stress-strain curves produced during torsional tests had a peculiar 'hump' that was characteristic of all specimens of this type / acase@tulane.edu

The complexity of the Corpus Christi festival in Cuzco, Peru, articulates the subtleties of cultural/ethnic definitions in an urban environment influenced by its unique precolombian past and pressured by modernization Participation in the festival rites form socially interwoven groups not restricted to but strongly influenced by residence, occupation and kinship--criteria which with language use, dietary habits and dress are the effective dimensions of ethnic classification and social stratification. These groups are identified with the city's traditional parish/barrios, where ethnic criteria define participants generally as Indians, specifically as Cuzquenos, and historically as Incas The festival's formal social structure is acephalous and heterogeneous. Festival performance is dependent upon the permanent, exclusive hermandades dedicated to specific festival rites and upon the ephemeral, inclusive cofrad(')ias insuring the participation of parish patronal saints. The non-hierarchical cargo structure of the cofrad(')ias has no formal relationship to secular offices Precolombian principles of socio-religious organization are encoded, validated and made manifest in the festival's symbolic structure and ritual drama Corpus Christi is commonly believed to be an extension of the Incan festival Inti Raimi. However, a close examination of the ethnohistorical sources strongly suggests that Corpus Christi resembles far more the Capacocha, a propitiatory/prophylactic rite involving both Incas and non-Incas Throughout its history, Corpus Christi has provided the overwhelming Indian majority with a sanctioned opportunity for expressing claims to socio-political precedence in opposition to Spanish/Mestizo cultural dominance, as well as for expressing shifting alliances among social groups within the Indian community Aspects of the festival's social and symbolic structures are shown to be but variants in a regional pattern when compared with other areal and calendric festivals. Corpus Christi marks a pivotal moment in a season of religious rites associated with important phases in the annual cycles of agricultural production, animal husbandry and celestrial phenomena The city's modern Jubilee Week with its ficticious 'reenactment' of Inti Raimi contrasts with Corpus Christi in the extreme. Inti Raimi is ideologically Mestizo; Corpus Christi, Indian. The two festivals embody two different but equally valid models of Cuzco and its Incan identity / acase@tulane.edu

acase@tulane.edu