Master of Architecture

Master of Architecture

Groundspace to bury the deceased has become a rare commodity. As an alternative, cemeteries are beginning to build large high density mausoleums to house the dead above ground. As I began to study the building type of a mausoleum, an issue perturbed me: As time passes, the loved ones of the deceased will pass on and no longer come to visit or care for the building. Most likely there will be a lack of funds, the building will no longer be maintained. The building will eventually deteriorate and become a ruin. What happens to the mortal remains? The conventional cemetery does not have to consider this issue, as the bodies are simply allowed to deteriorate in the ground, and the grave marker is able to withstand much more abuse than a building. The manner in which I have addressed this issue is to design the mausoleum to potentially become a ruin, and thus the mortal remains are returned to the earth. “FOR DUST YOU ARE AND TO DUST YOU WILL RETURN.” (GEN 3:19 NIV) / Master of Architecture

Every architect’s work is a set of conditions which, through various relations, may add frequently does have a significant influence on all who participate in the built environment. At the same time, both architects and their work are constantly exposed to various changing relations. When one considers the network of those mutual influences of which an architect and his environment are elements, “form” may be seen as the positioning of an object within a network of conditions and their relations. This network includes visual characteristics of an object, imposed by the architect, and those independent of him, which are culturally conditioned. Such a network constitutes what is understood by “form” in this project. Among visual relations, I have chosen to recognize for example rhythm, contrast, balance, proportions and transparency. The culturally implied (given) relations are, for example, ownership, use, tradition, fashion. All these relations, imposed by an architect and implied by a culture, reveal only a small fraction of this relational network, of which I have consciously chosen to consider only a few. Within this framework, the term “function” would describe a momentary suspension of the dynamics of the network of relations. It is called momentary because all of the elements are in contrast change. Consequently, so are their relations with other elements and, therefore, the overall aspect of the form. Function allows the “freezing” of the network in order to make the observation and critique of the object possible. Such observation can be performed only within certain imposed boundaries, since the entire framework, and consequently, both form and function, are limitless in their nature. Those boundaries reveal certain aspects of the object which are constituted from groups of considerations, which in this project are called “conditions”. Some of the “conditions” are later mentioned in the book a plan, elevation, shape. Since all of them resemble each other in their tendency towards balance, different parts of the project perform in a similar way. / Master of Architecture

The objective of this study was to provide an optical technique allowing full-field in-plane deformation measurements at high temperature by using high-sensitivity moiré interferometry. This was achieved by a new approach of performing deformation measurements at high temperatures in a vacuum oven using an achromatic interferometer. The moiré system setup was designed with particular consideration for the stability, compactness, flexibility, and ease of control. A vacuum testing environment was provided to minimize the instability of the patterns by protecting the optical instruments from the thermal convection currents. Also, a preparation procedure for the high-temperature specimen grating was developed with the use of the plasma-etched technique. Gold was used as a metallic layer in this procedure. This method was demonstrated on a ceramic block, metal/matrix composite, and quartz. Thermal deformation of a quartz specimen was successfully measured in vacuum at 980 degrees Celsius, with the sensitivity of 417 nm per fringe. The stable and well-defined interference patterns confirmed the feasibility of the developments, including the high-temperature moiré system and high-temperature specimen grating. The moiré system was demonstrated to be vibration-insensitive. Also, the contrast of interference fringes at high temperature was enhanced by means of a spatial filter and a narrow band interference filter to minimize the background noise from the glow of the specimen and heater. The system was verified by a free thermal expansion test of an aluminum block. Good agreement demonstrated the validity of the optical design. The measurements of thermal deformation mismatch were performed on a graphite/epoxy composite, a metal/matrix composite equipped with an optical fiber, and a cutting tool bit. A high-resolution data-reduction technique was used to measure the Strain distribution of the cutting tool bit. / Ph. D.

The final tensile fracture of any composite structure is primarily due to the failure of its constituents, namely fibers and matrix in the present case. To date, no experimental data exists, to the author’s knowledge, to define the behavior of constitutive fibers of a composite structure throughout its life span. The prime candidate for a fiber-based investigation is unidirectional zero-degree composite coupons. But unidirectional coupons do not demonstrate any significant loss of stiffness during fatigue cycling compared to other lay-ups. Even if stiffness degradation was significant, due to the nature of damage in this material system it would be impossible, practically, to monitor that change using conventional techniques (e.g. an extensometer) because the damage and failure process destroys the integrity of the contact between those devices and the material, under cyclic conditions. This investigation presents the findings of a fiber-based investigation of unidirectional composite material systems. In particular, a unidirectional graphite/epoxy system was studied, and the influence of applied load level on fiber fractures, and their influence on damage growth documented. A damage monitoring technique (patent pending) was developed to accurately record the state of damage in this material system without the usage of extensometers or strain gages. Following this method, two new damage norms were introduced, namely, “percent phase damage” and “percent gain damage”. Fiber fracture, strength degradation, and the life of unidirectional specimens were investigated and recorded as a function of various load levels. Fiber fracture, in general, showed no definitive growth pattern during fatigue cycling. It appears that the majority of the broken fibers that occur over nearly 90% of the life are due to the initial applied load cycle. This is one of the key findings of this investigation. “Proof testing” which is a common practice in industry for “verifying” the integrity of a structure, could very well be causing significant subsequent reductions in life. With these findings as a base, it is now possible to postulate the first well-founded mechanistic model of fiber-dominated fatigue degradation under tensile loading. / Ph. D.

The thermodynamic properties of aqueous sulfur species were estimated using a structure-based, group contribution additivity method that is based upon first-order approximations. Structural groups were chosen so as to minimize subjectivity and maximize the ease of recognition and include: (1) Sn^*, polymeric sulfur (as 1/n, where n is the length of the longest continuous sulfur chain in the species), (2) O₃S^IV; (3) O₃S^VI; (4) O₂S^III and (5) bridging oxygen. In addition, a modified "charge-to-size" ratio (C) is used to model the coulombic interaction between ions and the solvent. Multiple linear regressions of these thermodynamic data were performed in terms of structural groups to yield fundamental equations for the model. Regression coefficients were used to estimate thermodynamic properties of a number of aqueous species for which no experimental data currently exist. Model-derived thermodynamic data were used to find the thermodynamic stability of intermediate sulfur species that occur during the aqueous oxidation of sulfide minerals, which identified at least one thermodynamically feasible pathway for the overall reaction. The data were also used to construct an EhpH diagram for aqueous sulfur species with average sulfur oxidation states less than sulfate (VI). The structure-thermodynamic correlation was used to determine the likely structure of the aqueous S₂O₅²⁻ ion, which has been debated over the past 50 years. The rate of decomposition of the ferric thiosulfate complex was observed to vary as the square of the concentration of the complex. The decomposition of this complex in acid solutions is strongly dependent on temperature, E_a = 120(±15) kJ mol⁻¹. The rate of reaction increases was observed to increase with increasing ionic strength, consistent with the interaction of two positively charged ions to form the activated complex. This study resolves many of the inconsistencies found in earlier studies and shows that reaction with H⁺ is a more important sink for S₂O₃²⁻ than reaction with Fe³⁺ when pH > -1.7. Comprehensive rate laws for aqueous pyrite oxidation were produced using experimentally determined data and data reported in the literature. Rate data available in the literature for the reaction of pyrite with dissolved oxygen (DO) to were compiled to produce a rate law that is applicable over three and one half orders of magnitude in DO concentration over the pH range 2-10. A series of batch, and mixed flow reactor experiments were performed to determine the effect of SO₄²⁻, Cl⁻, ionic strength and dissolved oxygen on the rate of reaction of pyrite with ferric tron. Only dissolved oxygen was found to have any appreciable effect. The results of this study were combined with kinetic data reported in the literature to formulate rate laws that are applicable over a six order of magnitude range in Fe³⁺ and Fe²⁺ concentration for the pH range ~0.5-3.0. Fundamental rates laws were formulated for each system and showed that the reaction order for ferric iron changed, thus suggesting a change in reaction mechanism. An observed rate correlation with the Fe³⁺/Fe²⁺ ratio indicates that the rate is proportional to Eh, and is best modelled by a non-ideal, non-site specific Freundlich multilayer isotherm. Because rate is observed to be positively correlated with the concentration of the aqueous oxidant only, the rate determining step for the aqueous oxidation of pyrite can be identified as the electron transfer from the mineral to the oxidant. / Ph. D.

Solid propellant research has mainly been directed towards more accurate characterization of the propellant material nature and more reliable structural analysis of the grain. Internal star grain design is among the most popular grain shapes that are used in today's propulsion system. Due to its complex geometry, stress concentrations are inevitably present around the highly curved area. Furthermore, this geometric effect together with various loading conditions throughout the grain's service life actually causes numerous defects inside its body. However, little is known concerning the three-dimensional fracture mechanism of the surface cracks which are the most common defects detected in the real rocket motor grain. After a brief evaluation of the current status of solid propellant research, stress analysis of a star grain model under internal pressure was performed by both photoelastic experiments and finite element calculations. These results illustrated the stress concentration effect around the star finger tip in addition to the global stress distribution across the whole section. Meanwhile, the deformation of the grain's outer surface was also obtained from the finite element results. A series of photoelastic experiments was conducted on cracked specimens with surface flaws emanating both on and off the axis of symmetry starting from the star finger tip. For the symmetric crack problem, cracks with different depths were intensively studied and the three-dimensional stress intensity factor (SIF) distribution was obtained for each test. These experimental data were further used to construct three analytical models, the "equivalent" radius model, the weight function model and the notch-root crack model, to expand the application range of the experimental data base so that a symmetric crack's SIF distribution with an arbitrary depth can be predicted. Moreover, surface cracks initiated off the axis of symmetry were also investigated by considering two off-axis angles. The crack shape and propagation path were achieved through a series of experiments and two methods were developed to effectively predict the possible crack growth path under sufficient pressure. The SIF distribution around the crack border was obtained for different offaxis angles and the factors that might influence the distributions were addressed based on the comparisons between the symmetric and asymmetric cracks, and the asymmetric cracks with different geometries. / Ph. D.

Strategies for topology optimization of trusses and plane stress domains for minimum weight subject to stress and displacement constraints by Simultaneous Analysis and Design (SAND) are considered. The ground structure approach is used. For the truss topology optimization, a penalty function formulation of SAND is compared with an augmented Lagrangian formulation. The efficiency of SAND in handling combinations of general constraints for truss topology optimization is tested. A strategy for obtaining an optimal topology by minimizing the compliance of the truss is compared with a direct weight minimization solution to satisfy stress and displacement constraints. It is shown that for some problems, starting from the ground structure and using SAND is better than starting from a minimum compliance topology design and optimizing only the cross sections for minimum weight under stress and displacement constraints. One case where the SAND approach could not predict a singular topology obtained by compliance minimization is discussed in detail. A member elimination strategy to save CPU time is developed. For the plane stress topology optimization problem, the ground structure is obtained by using 3 noded constant stress triangular elements. A chess board pattern is observed in the optimal topologies which may be attributed to the triangular elements. Some suggestions for future research are made. / Ph. D.

The plsX50 mutation is required together with plsX26 (encoding a K_m- defective glycerol 3-phosphate acyltransferase) for the conferral of a glycerol 3- phosphate auxotrophic phenotype. A 4.9 kb segment of DNA complementing the plsX50 mutation have been cloned and sequenced. Six open reading frames (ORF’s) were found with five reading in the same direction and one in the opposite direction relative to the plsX gene. Each ORF encoded a protein, as demonstrated by radiolabeling in maxicells. ORF1 (orfY) encodes a protein of unknown function. ORF2 and ORF3 (rpmF) were sequenced prior to this study and encode a protein called G30k of unknown function and L32, a protein of the large ribosomal subunit, respectively. ORF4 complemented the p/sX50 mutation. ORFS was identified as fabH encoding 3-ketoacyl-ACP synthase III. ORF6 was identified as fabD encoding malonyl-CoA/ACP transacylase. The fabG gene encoding 3- ketoacyl-ACP reductase and the acpP gene encoding acy] carrier protein are located just downstream of the fabD gene. Northern and promoter activity analysis demonstrated that the rpmF-plsX-fabH-fabD-fabG-acpP genes comprise an operon suggesting a coordinate control of the synthesis of a ribosomal protein (L32), PlsX protein, and fatty acid biosynthetic enzymes. However, several features were identified that are likely to be important for differential expression of the individual genes. These include the presence of multiple promoters, an internal terminator (attenuator), differential degradation of transcripts, and differential efficiency of translation initiation. Portions of transcripts arising upstream of rpmF terminate at the attenuator located just downstream of the plsX initiation codon, and some of the transcripts continue into the plsX-jab genes. The fabH-fabD-fabG-acpP genes are also cotranscribed from a promoter located upstream of the fabH gene, within the pisX structural gene. There are additional cotranscripts responsible for the expression of the fabD-fabG-acpP genes. The acpP gene is encoded by several more transcripts. Transcription initiation sites upstream of rpmF were identified by primer extension analysis and the attenuator site was identified by S1 mapping analysis. N-terminal amino acid sequence analysis identified the translation initiation codons of orfY, plsX, fabH, fabD and fabG. Short intergenic distances (15 and 12 bp) found between fabH and fabD and between fabD and fabG implicate translational coupling as a mechanism for coordinate control of fabHDG expression. The p/sX50 mutation was identified as deletion of a single nucleotide from the 6th codon of plsX resulting in a frame shift nonsense mutation. / Ph. D.