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Numerical Modeling Of Self-Propagating Polymerization Fronts: The Role Of Kinetics On Front Stability, Stanislav E. Solovyov, Victor M. Llyashenko, John A. Pojman Jan 1997

Numerical Modeling Of Self-Propagating Polymerization Fronts: The Role Of Kinetics On Front Stability, Stanislav E. Solovyov, Victor M. Llyashenko, John A. Pojman

Faculty Publications

Frontal propagation of a highly exothermic polymerization reaction in a liquid is studied with the goal of developing a mathematical model of the process. As a model case we consider monomers such as methacrylic acid and n -butyl acrylate with peroxide initiators, although the model is not limited to these reactants and can be applied to any system with the similar basic polymerization mechanism. A three-step reaction mechanism, including initiation, propagation and termination steps, as well as a more simple one-step mechanism, were considered. For the one-step mechanism the loss of stability of propagating front was observed as a sequence …

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Regulation Of Root-Associated Methanotrophy By Oxygen Availability In The Rhizosphere Of Two Aquatic Macrophytes, Aram Calhoun, Gary M. King Jan 1997

Regulation Of Root-Associated Methanotrophy By Oxygen Availability In The Rhizosphere Of Two Aquatic Macrophytes, Aram Calhoun, Gary M. King

Faculty Publications

The relative importance of oxygen for root-associated methanotrophy was examined by using sediment-free, intact freshwater marsh plants (Pontederia cordata and Sparganium eurycarpum) incubated in split chambers. The root medium contained approximately 100 μM methane. Methane oxidation was calculated from the difference between methane loss from chambers in the presence and absence of 1 mM 1-allyl-2-thiourea, a methanotrophic inhibitor. When the root medium was oxic, methane oxidation accounted for 88 and 63% of the total methane depletion for S. eurycarpum and P. cordata, respectively; the remainder represented diffusional loss to the atmosphere via roots, stems, and leaves. Under suboxic conditions, methane …

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Variational Methods, Bounds, And Size Effects For Composites With Highly Conducting Interface, Robert Lipton Jan 1997

Variational Methods, Bounds, And Size Effects For Composites With Highly Conducting Interface, Robert Lipton

Faculty Publications

New variational principles are developed for the effective conductivity tensor for anisotropic two-phase electric conductors. Here the interface between phases is assumed to be highly conducting. Extra geometric information is encoded into the principles through the solution operators of simpler transport problems. These operators can be expressed as gradients of simple layer potentials with densities supported on phase interfaces or in terms of simple Dirichlet problems inside each phase region. New upper bounds on the effective conductivity are found that depend upon component volume fractions, a surface energy tensor and a scale-free matrix of parameters. This matrix corresponds to the …

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Reciprocal Relations, Bounds, And Size Effects For Composites With Highly Conducting Interface, Robert Lipton Jan 1997

Reciprocal Relations, Bounds, And Size Effects For Composites With Highly Conducting Interface, Robert Lipton

Faculty Publications

We provide a reciprocal relation linking the effective conductivity of a composite with highly conducting phase interfaces to that of a composite with the same phase geometry but with an electrical contact resistance at phase interfaces. A field relationship linking the electric field inside a composite with highly conducting phase interfaces to the current in a composite with contact resistance between phases is found. New size effects exhibited by isotropic particulate suspensions with highly conducting interface are obtained. The effective properties of periodic composites are shown to be monotonically increasing as the size of the period cell tends to zero. …

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Lsu General Catalog 1997-1998, Louisiana State University And Agricultural And Mechanical College Jan 1997

Lsu General Catalog 1997-1998, Louisiana State University And Agricultural And Mechanical College

LSU General Catalog

The LSU General Catalog describes all undergraduate and graduate departments and programs with degree requirements and courses offered for each one. The General Catalog includes information on registration and financial aid as well as academic services offered to all students.

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A Construction Of Representations Of Affine Weyl Groups, D. S. Sage Jan 1997

A Construction Of Representations Of Affine Weyl Groups, D. S. Sage

Faculty Publications

Let G be a complex, semisimple, simply connected algebraic group with Lie algebra g. We extend scalars to the power series field in one variable C((π)), and consider the space of Iwahori subalgebras containing a fixed nil-elliptic element of g ⊗ C((π)), i.e. fixed point varieties on the full affine flag manifold. We define representations of the affine Weyl group in the homology of these varieties, generalizing Kazhdan and Lusztig's topological construction of Springer's representations to the affine context.

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Does The Jones Polynomial Detect Unknottedness?, Oliver T. Dasbach, Stefan Hougardy Jan 1997

Does The Jones Polynomial Detect Unknottedness?, Oliver T. Dasbach, Stefan Hougardy

Faculty Publications

There have been many attempts to settle the question whether there exist nontrivial knots with trivial Jonespolynomial. In this paper we show that such a knot must have crossing number at least 18. Furthermore we give the number of prime alternating knots and an upper bound for the number of prime knots up to 17 crossings. We also compute the number of different HOMFLY, Jonesand Alexander polynomials for knots up to 15 crossings. © A K Peters, Ltd.

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Matching The "Matchless Orinda" To Her Times, Kathleen M. Swaim Jan 1997

Matching The "Matchless Orinda" To Her Times, Kathleen M. Swaim

1650-1850: Ideas, Aesthetics, and Inquiries in the Early Modern Era

No abstract provided.

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A Kantian Sublime In Shelley "Respect For Our Own Vocation" In An Indifferent Universe, Christoph Bode Jan 1997

A Kantian Sublime In Shelley "Respect For Our Own Vocation" In An Indifferent Universe, Christoph Bode

1650-1850: Ideas, Aesthetics, and Inquiries in the Early Modern Era

No abstract provided.

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Lattice Knot Theory And Quantum Gravity In The Loop Representation, Hugo Fort, Rodolfo Gambini, Jorge Pullin Jan 1997

Lattice Knot Theory And Quantum Gravity In The Loop Representation, Hugo Fort, Rodolfo Gambini, Jorge Pullin

Faculty Publications

We present an implementation of the loop representation of quantum gravity on a square lattice. Instead of starting from a classical lattice theory, quantizing, and introducing loops, we proceed backwards, setting up constraints in the lattice loop representation and showing that they have appropriate (singular) continuum limits and algebras. The diffeomorphism constraint reproduces the classical algebra in the continuum and has as solutions lattice analogues of usual knot invariants. We discuss some of the invariants stemming from Chern-Simons theory in the lattice context, including the issue of framing. We also present a regularization of the Hamiltonian constraint. We show that …

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Removal Of Hydrophobic Organic Compounds And Surfactants From Wastewater: Polyaphron-Enhanced Solvent Extraction And Biodegradation., Chunlong Zhang Jan 1997

Removal Of Hydrophobic Organic Compounds And Surfactants From Wastewater: Polyaphron-Enhanced Solvent Extraction And Biodegradation., Chunlong Zhang

LSU Historical Dissertations and Theses

Surfactant based processes are emerging and becoming increasingly important in pollution control. A novel predispersed solvent extraction (PDSE) technique using surfactant based colloidal liquid aphrons (CLAs or polyaphrons) and colloidal gas aphrons (CGAs) for the removal of hydrophobic organic compounds (HOCs) from the aqueous phase was studied. The process involves an extraction of HOCs into CLAs, followed by a flotation using CGAs. Polyaphrons were characterized by a particle size analyzer. The size distribution was found to be bimodal. The effects of surfactant types, surfactant concentrations and storage times on the size distribution were studied. Polyaphrons have long shelf-lives and are …

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Graphs And Number Theory., Brian Heck Jan 1997

Graphs And Number Theory., Brian Heck

LSU Historical Dissertations and Theses

In the 1930's, L. Redei and H. Reichardt used certain matrices to aid in the determination of the structure of ideal class groups of quadratic number fields. This is a classical number theoretic problem which in general presents diffculties. Ideal class groups are finite abelian groups, and it is a result of Gauss that allows us to determine their 2-rank, in other words the number of cyclic factors of even order. Redei and Reichardt worked on determining the 4-rank, the number of factors of order divisible by 4. Later, the classical study of circulant graphs was utilized to further help …

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A Computer Automated, Hydraulically Integrated Serial Turbidostat Algal Reactor (Histar): Mathematical Modeling And Experimental Analysis., Chandra Sekhar Theegala Jan 1997

A Computer Automated, Hydraulically Integrated Serial Turbidostat Algal Reactor (Histar): Mathematical Modeling And Experimental Analysis., Chandra Sekhar Theegala

LSU Historical Dissertations and Theses

Conceptually, the Hydraulically Integrated Serial Turbidostat Algal Reactor (HISTAR) has two components: (1) sealed turbidostats for producing a high quality algal inoculum, and (2) a series of unprotected inter-connected continuous flow stirred tank reactors (CFSTRs) for mass producing algae under approximated plug flow conditions. The hydraulic retention time of each individual CFSTR ($\theta\sb{\rm n})$ is set low enough (dilution is set high) that any suspended organisms (both contaminants and desired algae) entering the CFSTR would be washed to the next CFSTR well within their doubling time. However, as the turbidostats are employed to inoculate the first CFSTR on an almost …

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Quick Computation Of Spatial Autoregressive Estimators, R. Kelley Pace, Ronald Barry Jan 1997

Quick Computation Of Spatial Autoregressive Estimators, R. Kelley Pace, Ronald Barry

Faculty Publications

Spatial estimators usually require the manipulation of n2 relations among n observations and use operations such as determinants, eigenvalues, and inverses whose operation counts grow at a rate proportional to n3. This paper provides ways to quickly compute estimates when the dependent variable follows a spatial autoregressive process, which by appropriate specification of the independent variables can subsume the case when the errors follow a spatial autoregressive process. Since only nearby observations tend to affect a given observation, most observations have no effect and hence the spatial weight matrix becomes sparse. By exploiting sparsity and rearranging computations, …

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Model-Driven Simulation Of World-Wide-Web Cache Policies, Ying Shi, Edward Watson, Ye Sho Chen Jan 1997

Model-Driven Simulation Of World-Wide-Web Cache Policies, Ying Shi, Edward Watson, Ye Sho Chen

Faculty Publications

The World Wide Web (WWW) has experienced a dramatic increase in popularity since 1993. Many reports indicate that its growth will continue at an exponential rate. This growth has created a tremendous increase in network loads and user response times. The complexity and diversity of many WWW documents (e.g., texts, images, video, audio, etc.) and the diversity of user requested WWW information require sophisticated WWW cache management strategies. Several popular WWW cache algorithms perform rather poorly and lack mathematical or empirical foundations. As a result, WWW system administrators and browser users are forced to arbitrarily define certain important cache parameters. …

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Orientation Effects On African-American Engineering Students: The Lsu Case., Forest Dent Smith Jan 1997

Orientation Effects On African-American Engineering Students: The Lsu Case., Forest Dent Smith

LSU Historical Dissertations and Theses

Extended orientation courses continue to be introduced as curriculum offerings that assist students to persist in post-secondary institutions. Research on the outcomes of such courses in terms of student retention and achievement is, with regard to race, however, not proceeding at the same pace as orientation course research in general. The purpose of this study was to apply the attrition models of Tinto (1987) and Pascarella, Terenzini, and Wolfe (1986) and examine extended orientation as a contributing factor to the retention and achievement of African-American engineering students. The sample of the study consisted of 354 African-American students who were members …

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Coastal Restoration Using Pipeline-Conveyed Sediments., Catherine Faith Voisin Jan 1997

Coastal Restoration Using Pipeline-Conveyed Sediments., Catherine Faith Voisin

LSU Historical Dissertations and Theses

A spreadsheet program was successfully developed which determines the engineering requirements for pipeline transport of sediments from dredge sites to wetland restorations sites. The program called SLURRY.XLS involves several new correlations. A new correlation for determining the critical velocity of particle transport is presented. New correlations were statistically developed for determining the drag coefficient of particles. The spreadsheet also successfully determines settling velocities of the individual particle sizes in any settling regime. A second spreadsheet program entitled "CONSOL.XLS" uses geotechnical principles of consolidation for determining marsh surface elevation with and without hydraulic fill versus time. The CONSOL.XLS program permits the …

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Lie Theory Of Differentiable Transformations On Banach-Type Manifolds., Amadou Belly Guisse Jan 1997

Lie Theory Of Differentiable Transformations On Banach-Type Manifolds., Amadou Belly Guisse

LSU Historical Dissertations and Theses

Let M be a manifold modeled on a Banach space B, and let U be an open subset of M containing the domain of some chart $\varphi$. The aim of this work is to set mathematical foundations (topological, algebraic geometrical) for the theory of pseudosemigroups of local transformations S on M and their infinitesimal generators $L\sp{r}(S,\ U).$ In the first part of this dissertation we define the topology of local uniform convergence, the most suitable in this case, similar to the compact open topology in the finite dimensional case, and show what relationship it has with different topologies. In the …

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A Methodological Examination Of Naturally Occurring School Improvement In Louisiana Schools., John Albert Freeman Jan 1997

A Methodological Examination Of Naturally Occurring School Improvement In Louisiana Schools., John Albert Freeman

LSU Historical Dissertations and Theses

The study was conducted as an exploratory investigation of naturally occurring school improvement, which refers to improvement in a school's effectiveness status that is achieved without external change forces. The research design for the study used mixed methodologies divided into three phases to identify and examine schools that improved longitudinally in a "natural" environment. Phase I utilized regression (ordinary least squares) methods to create a database containing all elementary schools in Louisiana, categorized by their level of change. As a result, some 20% of the schools in Louisiana were identified as having improved over a three-year period. This approximated an …

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Pure Framed Braids And 3-Manifolds., Jonathan Natov Jan 1997

Pure Framed Braids And 3-Manifolds., Jonathan Natov

LSU Historical Dissertations and Theses

This dissertation looks at representations of framed pure braids and compact orientable three manifolds. A representation, $\Phi:Z\sp{n}\oplus P\sb{n}\to \Gamma\sb{n},$ is constructed from the framed pure braid group on n strands to the mapping class group on a surface of genus n. The representation is used to obtain a presentation of the fundamental group. The representation, like that of (M-P), is compatible with Heegaard and Surgery descriptions. An algorithm is presented for transforming mapping class group elements to a stably equivalent pure framed braid, under the correspondence given by the representation. A geometric description, using the representation, is given for multiplication …

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The Role Of The Unit As A Cognitive Bridge Between Additive And Multiplicative Structures., Nancy Sutton Alexander Jan 1997

The Role Of The Unit As A Cognitive Bridge Between Additive And Multiplicative Structures., Nancy Sutton Alexander

LSU Historical Dissertations and Theses

The rational number domain is known for the great difficulties it presents for students and teachers. As students construct knowledge of fractions, they search for connections to existing knowledge. Procedures from the whole number domain are tried, but many do not work on the new numbers! Recent research has focused on the unit as a way to link whole number and rational number understanding (Behr, Harel, Post & Lesh, 1992). Studies have suggested that students intuitively form units (Lamon, 1994), and that this intuitive knowledge can serve as a foundation for rational number understanding (Lamon, 1994; Mack, 1990). Golding (1994) …

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Optimization And Scale-Up Of Thiarubrine A Production From Hairy Root Cultures Of Ambrosia Artemisiifolia., Santosh G. Bhagwath Jan 1997

Optimization And Scale-Up Of Thiarubrine A Production From Hairy Root Cultures Of Ambrosia Artemisiifolia., Santosh G. Bhagwath

LSU Historical Dissertations and Theses

Thiarubrine A (TA), a plant secondary metabolite synthesized by members of the family Asteraceae possesses antifungal and antiviral properties and is a potential pharmaceutical. The objective of the work was the optimization and scale-up of a bioprocess for the production of TA using hairy root cultures of Ambrosia artemisiifolia. At the inception of the work an established hairy root culture of the model system was used as inoculum in reactor experiments for the development of a protocol for the quantification of TA and in subsequent shake flask experiments to determine optimum culture conditions. TA accumulation closely paralleled growth and then …

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An Integrated Gps-Gis Methodology For Performing Travel Time Studies., Cesar A. Quiroga Jan 1997

An Integrated Gps-Gis Methodology For Performing Travel Time Studies., Cesar A. Quiroga

LSU Historical Dissertations and Theses

This dissertation describes a methodology for conducting travel time studies based on global positioning system (GPS) receivers and geographic information system (GIS) technology. Compared to traditional approaches, the new methodology provides consistency, automation, finer levels of resolution, and better accuracy in measuring travel time and speed. These characteristics enable the detection of localized traffic effects much more efficiently than with traditional techniques. The new methodology automates the data collection and data reduction procedures, and provides improved procedures for documenting and analyzing travel time and speed data. As a result, large amounts of reliable travel time and speed data can be …

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Weak Convergence Of Interacting Stochastic Systems., George William Paslaski Jan 1997

Weak Convergence Of Interacting Stochastic Systems., George William Paslaski

LSU Historical Dissertations and Theses

The aim of the dissertation is to establish the weak convergence of mean-field interacting particle systems driven by Poisson random measures and semimartingales. The limit of the stochastic systems is identified by the use of martingale problems and Picard iteration schemes. The interacting systems driven by Poisson random measures are shown to be stable with respect to the coefficients of the system as well as the driving terms. The same results can be achieved when a random interaction term independent of the driving terms is introduced into the coefficients of the system. Equations driven by semimartingales do not neccesarily possess …

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Linear Matrix Inequality Approach To Robust Emergency Lateral Control Of A Highway Vehicle With Time-Varying Uncertainties., Robert Edward Benton Jr Jan 1997

Linear Matrix Inequality Approach To Robust Emergency Lateral Control Of A Highway Vehicle With Time-Varying Uncertainties., Robert Edward Benton Jr

LSU Historical Dissertations and Theses

New linear-matrix-inequality (LMI) based methods are developed for the static-output-feedback stabilization and reduced-gain static-output-feedback stabilization of time-invariant systems. Unlike previous methods, the static-output-feedback method is non-iterative in LMI solutions. The methods are extended to design robust static-output-feedback controllers for time-varying systems using a polytopic-systems approach. Examples are given which demonstrate the use of each of the new methods. The specific problem of emergency lateral control of a highway vehicle is then addressed using the new robust static-output-feedback method. A controller is designed which robustly stabilizes the vehicle over the range of highway speeds (15 to 30 m/s) and a range …

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Land/Water Interface Delineation Using Neural Networks., Rajabhushanam Cherukuri Jan 1997

Land/Water Interface Delineation Using Neural Networks., Rajabhushanam Cherukuri

LSU Historical Dissertations and Theses

The rapid decline in acreage of land areas in wetlands caused by frequent inundations and flooding has brought about an increased awareness and emphasis on the identification and inventory of land and water areas. This dissertation evaluates three classification methods--Normalized Difference Vegetation Index technique, Artificial Neural Networks, and Maximum-Likelihood classifier for the delineation of land/water interface conditions using Landsat-TM imagery. The effects of three scaling algorithms, including resampling by aggregation, Gaussian smoothing, and local variance analysis, on the classification accuracy are analyzed to determine how the delineation, quantification and analysis of land/water boundaries relate to problems of mixed pixels, scale …

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Coupled Field Equations For Saturated Soils And Its Application To Piezocone Penetration And Shield Tunneling., Murad Yusuf Abu-Farsakh Jan 1997

Coupled Field Equations For Saturated Soils And Its Application To Piezocone Penetration And Shield Tunneling., Murad Yusuf Abu-Farsakh

LSU Historical Dissertations and Theses

An elasto-plastic coupled system of equations are formulated here in order to describe the time-dependent deformation of saturated cohesive soils. Formulation of these equations is based on the principle of virtual work and the theory of mixtures for inelastic porous media as proposed by Prevost (1980) and Kiousis and Voyiadjis (1988). The saturated soil is considered as a mixture consisting of two deformable media, the solid grains and the water. Each medium is regarded as a continuum and follows its own motion. The coupled equations are developed for large deformations with finite strains in an updated Lagrangian reference frame. The …

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The Rainbow Portrait And The Faery Queen: Emblem, Imagination And The Arthurian Gentleman., Robert Gibson Robinson Iii Jan 1997

The Rainbow Portrait And The Faery Queen: Emblem, Imagination And The Arthurian Gentleman., Robert Gibson Robinson Iii

LSU Historical Dissertations and Theses

This work re-interprets the symbolism of the emblematic "Rainbow" portrait (c. 1600) of Elizabeth I. The traditional title comes from the identification of the rainbow in the portrait as that of Genesis 9:13. In fact, this work demonstrates, it is the philosophers' rainbow, a cryptonym for the colors--black, red, white--of the three stages of alchemic transmutation: purification, illumination, perfection. Elizabeth is represented as the Faery Queen, the alchemical monarch--historically the pre-Homeric Hecate--who transmutes not only the brazen world of her subjects but their brassy selves as well. In the text the portrait is therefore designated the "Alchemists' Rainbow" portrait, the …

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Technical Training Program Evaluation: Present Practices In United States' Business And Industry., Skip Twitchell Jan 1997

Technical Training Program Evaluation: Present Practices In United States' Business And Industry., Skip Twitchell

LSU Historical Dissertations and Theses

There is a lack of information on training evaluation. For those studies addressing the amount of evaluation that occurs and in which samples can be identified, the samples are non-random. There have been very few reports on the methods used for evaluation or the reasons why there is so little evaluation. This study used a random sample selected from members of the ASTD professional practice area titled, Technical and Skills Trainers. It can be argued that this is an informed sample involved in a training area that produces objective outcomes and should produce a favorable picture of training evaluation. Questions …

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The Composition Of Politics: Creativity In The Political Thought Of Simone Weil And Albert Camus., John Randolph Leblanc Jan 1997

The Composition Of Politics: Creativity In The Political Thought Of Simone Weil And Albert Camus., John Randolph Leblanc

LSU Historical Dissertations and Theses

This essay traces the critical development of the idea of creativity through the intellectual relationship of Simone Weil and Albert Camus. Members of the French Resistance during the Second World War, Camus and Weil never met. Camus became enamored of her work after her death and is largely responsible for its publication. Camus recognized in Weil a markedly distinct, but kindred, spirit. Despite the apparent conflict between her Christian mysticism and his existential orientation, they both sought the preservation of the specifically human in a world which, in valuing a mechanistic form of reason, tended to objectify the human. Their …

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