Time Reversed Electromagnetic Wave Propagation as a Novel Method of Wireless Power Transfer

We investigate the application of time-reversed electromagnetic wave propagation to transmit energy in a wireless power transmission system. “Time reversal” is a signal focusing method that exploits the time reversal invariance of the lossless wave equation to direct signals onto a single point inside a complex scattering environment. In this work, we explore the properties of time reversed microwave pulses in a low-loss ray-chaotic chamber. We measure the spatial profile of the collapsing wavefront around the target antenna, and demonstrate that time reversal can be used to transfer energy to a receiver in motion. We demonstrate how nonlinear elements can be controlled to selectively focus on one target out of a group. Finally, we discuss the design of a rectenna for use in a time reversal system. We explore the implication of these results, and how they may be applied in future technologies.

Effects of Wingwall Configurations on the Behavior of Integral Abutment Bridges

This research includes parametric studies performed with the use of three-dimensional nonlinear finite element models in order to investigate the effects of cantilever wingwall configurations on the behavior of integral abutment bridges located on straight alignment and zero skew. The parametric studies include all three types of cantilever wingwalls; inline, flared, and U-shaped wingwalls. Bridges analyzed vary in length from 100 to 1200 feet. Soil-structure and soil-pile interaction are included in the analysis. Loadings include dead load in combination with temperature loads in both rising and falling temperatures. Plasticity in the integral abutment piles is investigated by means of nonlinear plasticity models. Cracking in the abutments and stresses in the reinforcing steel are investigated by means of nonlinear concrete models. The effects of wingwall configurations are assessed in terms of stresses in the integral abutment piles, cracking in the abutment walls, stresses in the reinforcing steel of abutment walls, and axial forces induced in the steel girders. The models developed are analyzed for three types of soil behind the abutments and wingwalls; dense sand, medium dense sand, and loose sand. In addition, the models consider both the case of presence and absence of predrilled holes at the top nine feet of piles. The soil around the piles below the predrilled holes consists of very stiff clay. The results indicate that for the stresses in the piles, the critical load is temperature contraction and the most critical parameter is the use of predrilled holes. However, for both the stresses in the reinforcing steel and the axial forces induced in the girders, the critical load is temperature expansion and the critical parameter is the bridge length. In addition, the results indicate that the use of cantilever wingwalls in integral abutment bridges results in an increase in the magnitude of axial forces in the steel girders during temperature expansion and generation of pile plasticity at shorter bridge lengths compared to bridges built without cantilever wingwalls.

The Aesthetics of Motion in Musics for the Mevlana Celal ed-Din Rumi

This dissertation investigates the concept of motion as a fundamental aesthetic element in the devotional music, dance, and rituals performed in honor of the celebrated thirteenth-century Persian mystic poet and saint, the Mevlana Celal ed-Din Muhammad Rumi. The main focus of the study is threefold. First, it investigates the prevalence of the notion of movement in Islamic music and culture, specifically within the Sufi communities of Turkey, in order to arrive at a broader understanding of the relationship between music, aesthetics, and worldview. Secondly, it explores how musical performance functions as a form of devotion or religious worship by focusing on the musical repertories performed in honor of a single holy figure, the Mevlana Rumi. Finally, it provides an ethnographic account of contemporary developments in Sufi musical culture in Turkey and across the world by describing the recent activities of the Mevlana's devotees, which includes members of the Mevlevi Order of Islamic mystics as well as adherents of other Sufi brotherhoods and followers of so-called New Religions or New Age. The primary research for this study involved two short one-month field trips to Turkey and India in 2002 and 2003, respectively, and a longer one year expedition to Turkey in 2004 and 2005, which also included shorter stays in Cyprus, Syria, and Egypt. Additionally, the dissertation draws directly from critical theories advanced in the fields of ethnomusicology, cultural anthropology, and ethnochoreology and focuses on the kinesthetic parameters of music, dance, trance, and ritual as well as on broader forms of socio-cultural movement including pilgrimage, cultural tourism, and globalization. These forms of movement are analyzed in four broad categories of music used in worship, including classical Mevlevi music, music of the zikr ceremony, popular musics, and non-Turkish musics.

Assessing the viability of studying motion indicators of autism spectrum disorders in infants at high and low risk for ASD using a passive motion capture system

Gemstone Team AMIRA