yes / Polypropylene mesh for pelvic floor surgery is associated with serious complications ( e.g. erosion). A biodegradable tissue engineered mesh composed of a polylactic acid (PLA) scaffold seeded with autologous cells is a promising alternative. However, thus far elastin content (important for elastic recoil) in this tissue has been low. We aimed to increase elastin expression and test the resultant tensile properties.

<p> This thesis describes the construction and testing of small-scale shear wall buildings with rigidly connected floor slabs, but without wall openings. A micro-concrete material was used in the casting of both the basic small-scale shear wall buildings and the floor slabs. The vertically cantilevered buildings were tested by applying a transverse static load at the top of the buildings.</p> <p> The behaviour of buildings with only floor slabs was compared with that of buildings containing only wall openings. The results of static loading of the buildings were compared with those results predicted analytically using Vlasov's thin-walled elastic beam theory.</p> / Thesis / Master of Engineering (MEngr)

No description available.

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Earth and Planetary Sciences, 1979. / Microfiche copy available in Archives and Science. / Bibliography: leaves 73-75. / by Steven J. Hellinger. / Ph.D.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Earth and Planetary Sciences, 1981. / Microfiche copy available in Archives and Science. / Bibliography: leaves 102-106. / by Joann Miriam Stock. / M.S.

No / Precast concrete hollow core floor units (hcu) are widely used in all types of multistorey steel framed buildings where they bear onto the top flanges of universal beams. The steel beam is normally designed in bending, in isolation from the concrete slab, and no account is taken of the composite beam action available with the precast units. A program of combined experimental and numerical studies was undertaken that aimed at deciding on a suitable approach for the design of composite steel beams that utilize precast concrete hollow core slabs. The results show that the precast slabs may be used compositely with the steel beams in order to increase both flexural strength and stiffness at virtually no extra cost, except for the headed shear studs. For typical geometry and serial sizes, the composite beams were found to be twice as strong and three times as stiff as the equivalent isolated steel beam. The failure mode was ductile, and may have been controlled by the correct use of small quantities of tie steel and insitu infill concrete placed between the precast units.

The possibility of using a commercially available structural analysis program to predict the response of a floor system due to walking excitation as given in AISC Design Guide 11, Floor Vibrations Due to Human Activity (Murray, et al., 1997) was explored. This research included ideal floors that did not have measured values as well as several case study floors that do have measured values for the fundamental frequency. First, multiple model set-ups and loading protocols are applied to the ideal floors and the results compared to results from the Design Guide procedure. A recommendation of the best combination of a model set-up and loading protocol that best matches the Design Guide procedure results is made. Then, case study floors are modeled with the recommended model set-up and loading protocol, and the results compared to the results from the Design Guide procedure and to measured fundamental frequencies. The peak accelerations are also compared to subjective evaluations as to the acceptability of the system. Next, multiple systems were analyzed using five different modeling techniques, including the Design Guide Method, an alteration of the Design Guide Method, the Rayleigh Method, the Analytical Method, and the structural analysis program method, in an attempt to determine the source of discrepancies between the structural analysis program method and the Design Guide method. Finally, conclusions are drawn regarding the structural analysis program procedure as well as possible sources of differences. In general, the structural analysis program procedure reliably predicts the fundamental frequency of a floor system, but does not predict the Design Guide peak acceleration under dynamic loading. The difference in the effective mass of a system between the two methods is a source of discrepancy. / Master of Science

Floor vibrations due to occupancy activities on a floor are sometimes annoying to the occupants. Correcting floor vibrations is difficult and can be expensive. The use of tuned mass dampers to control annoying floor vibrations is sometimes a viable solution. Tuned mass dampers (TMDs) have been used primarily to control only one or two modes of vibration of a floor. Experimental research was performed using prototype TMDs to control one, two, and three modes of vibration of various floors. Results from this research are presented in this thesis. Analytical research, performed to obtain information about floor vibration characteristics, is presented and used for the initial design of TMDs and placement of TMDs on a floor. Also, computer models of the floors with TMDs to control one, two, and three modes of vibration were analyzed to obtain further information about changes in floor response and vibration characteristics. This research was performed to provide further insight on the effectiveness of TMDs to control one, two, and three modes of floor vibration and the effects of TMDs on floor vibration characteristics. / Master of Science

This collection of drawings and paintings presents a proposal for a ballroom dance center in Montreal, Quebec, Canada. The building is unnecessarily generous with the most essential elements and exaggerates non-essential elements in a way enhances their redundancy. Layered glulam ceilings cover the two main spaces and evoke the hidden structure of the sprung dance floor below. The ceiling is reflected in the pattern of the hardwood floors, and the ballroom is reflected in the pool outside its layered facade. Layers of concrete walls create thresholds and add depth to the views between spaces. Light, material, and people follow indirect paths through the building and its detailed elements. / Master of Architecture

Although mechanical alterations to pelvic floor ligaments, such as the cardinal and uterosacral ligaments, are one contributing factor to the development and progression of pelvic floor disorders, very little research has examined their mechanical properties. In this study, the first biaxial elastic and viscoelastic tests were performed on uterosacral and cardinal ligament complexes harvested from adult female swine. Biaxial elastic testing revealed that the ligaments undergo large strains and are anisotropic. The direction normal to the upper vagina was typically stiffer than the transverse direction. Stress relaxation tests showed that the relaxation was the same in both directions, and that more relaxation occurred when the tissue was stretched to lower initial strains. In order to describe the experimental findings, a three-dimensional constitutive model based on the Pipkin-Rogers integral series was formulated and the parameters of such model were determined by fitting the model to the experimental data. In formulating the model, it was assumed that the tissues consist of a ground substance with two embedded families of fibers oriented in two directions and that the ligaments are incompressible. The model accounts for finite strains, anisotropy, and strain-dependent stress relaxation behavior. This study provides information about the mechanical behavior of female pelvic floor ligaments, which should be considered in the development of new treatment methods for pelvic floor disorders. / Master of Science