Transport phenomena in nanotube quantum dots from strong to weak confinement

We report low-temperature transport experiments on single-wall nanotubes with metallic leads of varying contact quality, ranging from weak tunneling to almost perfect transmission. In the weak tunneling regime, where Coulomb blockade dominates, the nanotubes act as one-dimensional quantum dots. For stronger coupling to the leads the conductance can be strongly enhanced by inelastic cotunneling and the Kondo effect. For open contacts Coulomb blockade is completely suppressed, and the low-temperature conductance remains generally high, although we often see distinct dips in the conductance versus gate voltage which may result from resonant backscattering.Comment: 4 pages including 3 figures, for proceedings of the Moriond meeting 200

Shell filling in closed single-wall carbon nanotube quantum dots

We observe two-fold shell filling in the spectra of closed one-dimensional quantum dots formed in single-wall carbon nanotubes. Its signatures include a bimodal distribution of addition energies, correlations in the excitation spectra for different electron number, and alternation of the spins of the added electrons. This provides a contrast with quantum dots in higher dimensions, where such spin pairing is absent. We also see indications of an additional fourfold periodicity indicative of K-K' subband shells. Our results suggest that the absence of shell filling in most isolated nanotube dots results from disorder or nonuniformity.Comment: 4 pages including 4 figure

Does one need to understand why health is valuable in order to find enhancement permissible?

This article uses Lindemann’s feminist ethics to counter Julian Savulescu’s claim that enhancement is acceptable. It makes the claim that Savulescu misunderstands the need for health. Savulescu’s conceptualization of health and mode of enhancement would uphold existing distributive justice problems and support existing oppressive power structures. As such, enhancement in the way that Savulescu conceptualizes it is unethical

Targeted Sanctions - Case Study: Iran

In Iran’s history, there have been two prominent periods where international interference has led to a marked decrease in state revenue. One of these periods was in 1953, when a Central Intelligence Agency coup allowed the Anglo-Iranian oil company to reclaim possession of Iranian oil. The second was in 2006 to 2015, when the international community imposed various sanctions on Iran in order to curb the country’s nuclear weapons program. These sanctions regimes led to the crafting and acceptance of the Joint Comprehensive Plan of Action. Charles Tilly’s theory of state formation shows how the change in capital is tied to key events that changed the coercive capacity of the Iranian government

One-dimensional transport in bundles of single-walled carbon nanotubes

We report measurements of the temperature and gate voltage dependence for individual bundles (ropes) of single-walled nanotubes. When the conductance is less than about e^2/h at room temperature, it is found to decrease as an approximate power law of temperature down to the region where Coulomb blockade sets in. The power-law exponents are consistent with those expected for electron tunneling into a Luttinger liquid. When the conductance is greater than e^2/h at room temperature, it changes much more slowly at high temperatures, but eventually develops very large fluctuations as a function of gate voltage when sufficiently cold. We discuss the interpretation of these results in terms of transport through a Luttinger liquid.Comment: 5 pages latex including 3 figures, for proceedings of IWEPNM 99 (Kirchberg

Women's Athletics at the University of Kansas during the Progressive Era, 1890-1920

While the basic outline of the educational history of women at the University of Kansas is known, their athletic history is a bit more difficult to trace (Griffin, 1974). Very few records have been kept that reveal the true beginning of female participation in sports. Mable Lee includes the University of Kansas with several other institutions where physical education programs (called Physical Culture at the time) were set up for women (1893) before men (1894) (Lee, 1983). Further research shows that in 1884, ten years earlier, the women of the University were already benefiting from exercise and participation in the form of the Ladies Senior Boating Club (Cicala, 1884). Just two years later, the university yearbook featured a women's tennis team. The purpose of this study is to trace the origin and the development of women's intercollegiate athletics at the University of Kansas during the Progressive Era; to identify and record the significant events and achievements that comprised the historic growth of the women's sports program during the selected period; and to identify the leaders and coaches who contributed significantly to the women's sports program (Hooker, 1988). Sparhawk, Leslie, Turbow and Rose (1989) point out that, "the modern history of American women's participation in athletic competition can be divided into four periods: the Pre-Organizational Era (1887-1916), the Organizational Years (1917-1956), the Competitive Period (1957-1971), and the Title IX era (1972-1987)" (Sparhawk, 1989). The focus of this paper will be the Pre-Organizational Era which coincides with the Progressive Era. Chapter 1 is the introduction to the study. Chapter 2 will describe higher education and educational opportunities for women during this time period. Chapter 3 will introduce leisure, sports and college athletics for women. Chapter 4 will in detail give the history of women's athletic participation at the University of Kansas from 1890-1920. Finally, Chapter 5 is a brief overview from 1950 through today. Chapter 6 serves as the conclusion. The athletic lives of the women at the University of Kansas during the Progressive Era paralleled the lives of other women at major universities throughout the mid-west. The "athletic girl" embodied in the image of the 'New Woman' is a direct outgrowth of these women. While not always accepted by fellow students, the administration or society, the first female athletes at the university "confronted and overcame the contradiction inherent in being both 'woman' and 'athlete'

SEEDS OF AGRIBUSINESS: GRANT WOOD AND THE VISUAL CULTURE OF GRAIN FARMING, 1862-1957

This dissertation uses selected works of Grant Wood's art as a touchtone to investigate a broader visual culture surrounding agriculture in America during the late nineteenth and early twentieth centuries. By doing so I argue that Wood engaged with pressing social questions, including the phenomenon now referred to as agribusiness. Although agribusiness is often associated with the Green Revolution of the 1940s and 1950s, its beginning dates to the nineteenth century. Indeed, Wood's lifetime was an era when land was consolidated, production and distribution were vertically integrated, and breeding became scientifically informed. To access the power dynamics of this transition, I begin each chapter with work by Wood, and then analyze it in conjunction with imagery produced by or for individuals with diverse cultural agendas. This wide range of voices includes government officials, members of socialist farm organizations, newspaper publishers, plant breeders, owners of large and small farms, auction house managers, and university educators. To show precedents for and the legacy of Wood's work I begin my analysis of visual culture before his birth and end after his death. The dissertation thus begins in 1862—the year that land in the Midwest began to be parceled out for grain farming as small 160-acre homesteads and gargantuan bonanza farms thousands of acres in size. The dissertation ends in 1957—the year that the term agribusiness was coined by the Harvard-based economists John Davis and Ray Goldberg. I take an interdisciplinary approach anchored most fully within the norms of art history, but also engage with strategies from visual, cultural, and agricultural studies. My argument, ultimately, is that agribusiness is a cornerstone of modern thinking, and that Grant Wood was not only aware of the experiences, debates, institutions, and theories of agribusiness emerging in his midst but engaged with them in his fine art. More broadly, by using a wide range of imagery, including photography, advertising, penmanship, film stills, crops, cartoons, architecture, and diagrams I show that the way Americans came to understand and accept agribusiness as the basis of their food system was negotiated, in part, through visual materials

A status study of art education for youth in the Greater Boston area

Thesis (M.F.A.)--Boston Universit

A Pedagogy of Play: How Pre- and In-Service Early Childhood Teachers’ Perceptions of Play are Influenced as a Result of Practicum Experience in a Play-Based Environment

There is a growing body of research behind the play-based movement in education today – a topic that is somewhat controversial (Nicolopoulou et al., 2010; Overstreet, 2018). While some are steeped in a more classical approach to early education, advocating learning should be painful (Adler & Van Doren, 1988), others are paving the way for a more progressive approach, suggesting play to be the premier window into a child’s development (Paley, 1979-2014; Wohlwend & Peppler, 2015). The purpose of this study was to look at how the perceptions of pre- and in-service teachers changed regarding play and storytelling after participating in a play and inquiry practicum. The study examined the experiences of 27 teachers, each with a story as unique as the person they grew to become. In an effort to understand, holistically, how the teachers were growing and changing, a triangulation of methods were employed - including the documentation of daily interactions, quantitative analyses, and in-depth interviews. The teachers, overall, reported a philosophical awakening, following the week of readings (Pre-Survey Composite = 1,565). For most, a slight reservation about the practical aspects of play, following the intensive week of teacher preparation work (Post 1 Composite = 1,487). And finally, a better understanding of play, theoretically and practically, following the three week play and inquiry workshop with the community children (Post 2 Composite = 1,513)

Anisotropic de Gennes narrowing in confined fluids

The collective diffusion of dense fluids in spatial confinement was studied by combining high-energy (21 keV) x-ray photon correlation spectroscopy and small-angle x-ray scattering from colloid-filled microfluidic channels. We found the structural relaxation in confinement to be slower compared to bulk. The collective dynamics is wave vector dependent, akin to de Gennes narrowing typically observed in bulk fluids. However, in stark contrast to bulk, the structure factor and de Gennes narrowing in confinement are anisotropic. These experimental observations are essential in order to develop a microscopic theoretical description of collective diffusion of dense fluids in confined geometries.Comment: 5 pages, 2 figures, accepted for publication in Phys Rev Let