3,376 research outputs found

    The Church as Symbolic Mediation: Revelation Ecclesiology in the Theology of Avery Dulles, S.J.

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    This dissertation examines closely the theology of Avery Dulles, S.J., arguing that when Dulles\u27 symbolic-mediation theology of revelation is viewed through the lens of his sacramental ecclesiology, there emerges an ecclesiology that recognizes and emphasizes the revelatory nature of the church. This study constructs this revelation ecclesiology by bringing Dulles\u27 signature theologies of the church and revelation into conversation. At the intersection of those two theologies stands the reality of symbol - a defining characteristic for both the theology of the church as a sacramental reality and the theology of revelation as an event of divine self-communication. The study begins, therefore, by defining the concept of symbol, and the related foundational concepts of revelation, church and sacrament, as they function theologically within Dulles\u27 corpus. The study then demonstrates the crucial role of symbol in the development of Dulles\u27 sacramental ecclesiology, arguing that the unique efficacy of symbol lies at the heart of the sacramental reality. Because of its sacramental nature, the church demonstrates the efficacy and modality of symbol, but also possesses an ontological connection to Christ, the primordial sacrament. The study continues with a demonstration of Dulles\u27 conviction that the phenomenon of divine revelation is an event of communication with a transactional character. Revelation requires both an offer and a reception in order to realize itself as an accomplished event, however, this reception must be according to the mode of the receiver and thus requires a mediation. Symbol is the reality that is uniquely capable of providing this necessary mediation. Finally, the study concludes that Dulles\u27 corpus provides evidence that the sacrament of the church functions as precisely that symbolic mediation which characterizes the event of revelation. Thus the sacrament of the church is what Dulles has termed a revelatory symbol, i.e., one which expresses and mediates God\u27s self-communication in Christ. A final chapter concludes the study with an exploration of the implications of the constructed revelation ecclesiology for several significant current theological issues and questions: the mission of the church, the unity of revelation, the possibility and necessity of ecclesial reform, ecumenical dialogue, and the question of the closure of revelation

    Nonanalytic correlation length in Ising systems with one surface defect line

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    A two-dimensional Ising system with ferromagnetic coupling and one defect line at distance L from the surface is solved exactly using Pfaffians. The system shows a singularity in the surface correlation length at a temperature T_s which is smaller than the transition temperature T_c of the bulk. Numerical studies using the transfer matrix technique suggest that this singularity is also present in an Ising system with two defect lines at distance L.Comment: 18 pages incl. 7 figures, PD

    Casimir interactions in Ising strips with boundary fields: exact results

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    An exact statistical mechanical derivation is given of the critical Casimir forces for Ising strips with arbitrary surface fields applied to edges. Our results show that the strength as well as the sign of the force can be controled by varying the temperature or the fields. An interpretation of the results is given in terms of a linked cluster expansion. This suggests a systematic approach for deriving the critical Casimir force which can be used in more general models.Comment: 10 pages, 4 figure

    Development of the Monolith Froth Reactor for Catalytic Wet Oxidation of CELSS Model Wastes

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    The aqueous phase oxidation of acetic acid, used as a model compound for the treatment of CELSS (Controlled Ecological Life Support System) waste, was carried out in the monolith froth reactor which utilizes two-phase flow in the monolith channels. The catalytic oxidation of acetic acid was carried out over a Pt/Al2O3 catalyst, prepared at The University of Tulsa, at temperatures and pressures below the critical point of water. The effect of externally controllable parameters (temperature, liquid flow rate, distributor plate orifice size, pitch, and catalyst distance from the distributor plate) on the rate of acetic acid oxidation was investigated. Results indicate reaction rate increased with increasing temperature and exhibited a maximum with respect to liquid flow rate. The apparent activation energy calculated from reaction rate data was 99.7 kJ/mol. This value is similar to values reported for the oxidation of acetic acid in other systems and is comparable to intrinsic values calculated for oxidation reactions. The kinetic data were modeled using simple power law kinetics. The effect of "froth" feed system characteristics was also investigated. Results indicate that the reaction rate exhibits a maximum with respect to distributor plate orifice size, pitch, and catalyst distance from the distributor plate. Fundamental results obtained were used to extrapolate where the complete removal of acetic acid would be obtained and for the design and operation of a full scale CELSS treatment system

    The connection between the peaks in velocity dispersion and star-forming clumps of turbulent galaxies

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    We present Keck/OSIRIS adaptive optics observations with 150-400 pc spatial sampling of 7 turbulent, clumpy disc galaxies from the DYNAMO sample (0.07<z<0.20.07<z<0.2). DYNAMO galaxies have previously been shown to be well matched in properties to main sequence galaxies at z∼1.5z\sim1.5. Integral field spectroscopy observations using adaptive optics are subject to a number of systematics including a variable PSF and spatial sampling, which we account for in our analysis. We present gas velocity dispersion maps corrected for these effects, and confirm that DYNAMO galaxies do have high gas velocity dispersion (σ=40−80\sigma=40-80\kms), even at high spatial sampling. We find statistically significant structure in 6 out of 7 galaxies. The most common distance between the peaks in velocity dispersion and emission line peaks is ∼0.5\sim0.5~kpc, we note this is very similar to the average size of a clump measured with HST Hα\alpha maps. This could suggest that the peaks in velocity dispersion in clumpy galaxies likely arise due to some interaction between the clump and the surrounding ISM of the galaxy, though our observations cannot distinguish between outflows, inflows or velocity shear. Observations covering a wider area of the galaxies will be needed to confirm this result.Comment: Accepted for publication in MNRA

    Size-scaling of clump instabilities in turbulent, feedback regulated disks

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    We explore the scaling between the size of star-forming clumps and rotational support in massively star-forming galactic disks. The analysis relies on simulations of a clumpy galaxy at z=2z=2 and the observed DYNAMO sample of rare clumpy analogs at z≈0.1z\approx0.1 to test a predictive clump size scaling proposed by \citet{Fisher2017ApJ...839L...5F} in the context of the Violent Disk Instability (VDI) theory. We here determine the clump sizes using a recently presented 2-point estimator, which is robust against resolution/noise effects, hierarchical clump substructure, clump-clump overlap and other galactic substructure. After verifying Fisher's clump scaling relation for the DYNAMO observations, we explore whether this relation remains characteristic of the VDI theory, even if realistic physical processes, such as local asymetries and stellar feedback, are included in the model. To this end, we rely on hydrodynamic zoom-simulations of a Milky Way-mass galaxy with four different feedback prescriptions. We find that, during its marginally stable epoch at z=2z=2, this mock galaxy falls on the clump scaling relation, although its position on this relation depends on the feedback model. This finding implies that Toomre-like stability considerations approximately apply to large (∼kpc\sim\rm kpc) instabilities in marginally stable turbulent disks, irrespective of the feedback model, but also emphasizes that the global clump distribution of a turbulent disk depends strongly on feedback.Comment: Accepted by ApJ, no changes made. 11 pages, 4 figure

    Faceting Transition in an Exactly Solvable Terrace-Ledge-Kink model

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    We solve exactly a Terrace-Ledge-Kink (TLK) model describing a crystal surface at a microscopic level. We show that there is a faceting transition driven either by temperature or by the chemical potential that controls the slope of the surface. In the rough phase we investigate thermal fluctuations of the surface using Conformal Field Theory.Comment: 27 pages, 18 EPS figure

    Non-locality and short-range wetting phenomena

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    We propose a non-local interfacial model for 3D short-range wetting at planar and non-planar walls. The model is characterized by a binding potential \emph{functional} depending only on the bulk Ornstein-Zernike correlation function, which arises from different classes of tube-like fluctuations that connect the interface and the substrate. The theory provides a physical explanation for the origin of the effective position-dependent stiffness and binding potential in approximate local theories, and also obeys the necessary classical wedge covariance relationship between wetting and wedge filling. Renormalization group and computer simulation studies reveal the strong non-perturbative influence of non-locality at critical wetting, throwing light on long-standing theoretical problems regarding the order of the phase transition.Comment: 4 pages, 2 figures, accepted for publication in Phys. Rev. Let
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