Observation of Quantum Shock Waves Created with Ultra Compressed Slow Light Pulses in a Bose-Einstein Condensate

We have used an extension of our slow light technique to provide a method for inducing small density defects in a Bose-Einstein condensate. These sub-resolution, micron-sized defects evolve into large amplitude sound waves. We present an experimental observation and theoretical investigation of the resulting breakdown of superfluidity. We observe directly the decay of the narrow density defects into solitons, the onset of the `snake' instability, and the subsequent nucleation of vortices.Comment: 15 pages, 5 figure

People objects : 3-D modeling of heads in real-time

Thesis (S.M.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 1998.Includes bibliographical references (p. 54-59).by Thomas E. Slowe.S.M

A High Flux Source of Cold Rubidium

We report the production of a continuous, slow, and cold beam of 87-Rb atoms with an unprecedented flux of 3.2 x 10^12 atoms/s and a temperature of a few milliKelvin. Hot atoms are emitted from a Rb candlestick atomic beam source and transversely cooled and collimated by a 20 cm long atomic collimator section, augmenting overall beam flux by a factor of 50. The atomic beam is then decelerated and longitudinally cooled by Zeeman slowing

A Zeeman Slower based on magnetic dipoles

A transverse Zeeman slower composed of an array of compact discrete neodymium magnets is considered. A simple and precise model of such a slower based on magnetic dipoles is developed. The theory of a general Zeeman slower is modified to include spatial nonuniformity of the slowing laser beam intensity due to its convergence and absorption by slowed atoms. The slower needs no high currents or water cooling and the spatial distribution of its magnetic field can be adjusted. In addition the slower provides a possibility to cool the slowed atoms transversally along the whole length of the slower. Such a slower would be ideal for transportable optical atomic clocks and their future applications in space physics.Comment: 17 pages, 9 figure

The role of the institution in scholarly publishing

In providing a supportive and sustainable research environment, the institution has a key role to play in scholarly publishing. Whether that be as a guide, assisting researchers through the maze of publishing options and access to specialist audiences, or as an auditor for funders, or as a financer, agreeing article processing charges and subsidising website maintenance. Equally, the institution is the specialist systems developer and protector of the ‘unpublished’ research. This ensures repositories meet the needs of their researchers. In a wider context, the institution is the rewarder of scholarly publishing though promotions and the horizon scanner, preparing researchers for what is coming next. This piece looks at how the multiple roles of the institution in scholarly publishing impact researchers

Ableism and Exclusion: Challenging Academic Cultural Norms in Research Communication

Academic institutions are abelist. This, however, does not have to be the case. How do individuals involved in research management address this culture? In the context of the drastic changes in Higher Education since the 1990s, and an increasing emphasis on equality and inclusion, initiatives such as Athena Swan and the Race Equality Charter have led to more awareness of exclusionary practices. However, statistics on disability highlight serious issues in relation to disclosure rates for staff and staff report being stigmatised and their career choices undermined or invalidated. This can be particularly true for those who research into or around ableism. In this environment how can research managers raise awareness and empower all academics to ask for and gain adjustments to support their work? How has the Covid-19 pandemic and the impact on higher education institutions and their finances affected this issue? In this paper we consider some of the challenges of conducting research on ableism in academia and what it can tell us. We then discuss the changes that can be made to research management that would help address and challenge the ableist academic culture. This would be achieved through raising expectations, placing inclusivity and accessibility at the heart of research communication and encouraging, equipping and challenging the academic community to embed these practices in the dissemination of their research

Atom lasers: production, properties and prospects for precision inertial measurement

We review experimental progress on atom lasers out-coupled from Bose-Einstein condensates, and consider the properties of such beams in the context of precision inertial sensing. The atom laser is the matter-wave analog of the optical laser. Both devices rely on Bose-enhanced scattering to produce a macroscopically populated trapped mode that is output-coupled to produce an intense beam. In both cases, the beams often display highly desirable properties such as low divergence, high spectral flux and a simple spatial mode that make them useful in practical applications, as well as the potential to perform measurements at or below the quantum projection noise limit. Both devices display similar second-order correlations that differ from thermal sources. Because of these properties, atom lasers are a promising source for application to precision inertial measurements.Comment: This is a review paper. It contains 40 pages, including references and figure

Supporting Open Access at Kent – new staff roles

Open Access has been supported at the University of Kent from an early stage with the establishment of the Kent Academic Repository in 2007. Initially, this work was accommodated within the existing library staff structure, but the pace of change, funder requirements and a new university plan meant that support for Open Access needed to become explicit and a research support team was established using a matrix working system . This article details this new structure and reflects on the benefits and challenges it brings

Design of a prototyping press for 3-d monolithic compliant mechanisms

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2004.Includes bibliographical references (p. 38).The Precision Systems Design and Manufacturing Lab at the Massachusetts Institute of Technology has the need for a metal forming device capable of applying a plastic deformation to two-dimensional sheet metal templates of up to 1/8-inch thickness and 8-inch diameter in order to transform them into prototype three-dimensional monolithic compliant mechanisms. These mechanisms have applications in industrial positioning as they are highly accurate and free from normal performance reducers such as friction, wear, and backlash. This thesis presents the design of a prototyping press capable of achieving the deformation required to produce the 3DMCMs from their 2D templates. The prototyping press that is developed herein utilizes a multiple-piston, hydropneumatic cylinder to deliver up to 5,000 lbf over a 4-inch stroke. The press offers force sensing to within 10%, displacement sensing to within 0.005 inches, and rate control centered around a 6-inch per minute average rate. It is powered by a compressed air supply at up to 100 psi and motion is controlled by a single electrical solenoid shut-off valve.by Thomas J. Slowe.S.B

Maternal Weaning Modulates Emotional Behavior and Regulates the Gut-Brain Axis.

Evidence shows that nutritional and environmental stress stimuli during postnatal period influence brain development and interactions between gut and brain. In this study we show that in rats, prevention of weaning from maternal milk results in depressive-like behavior, which is accompanied by changes in the gut bacteria and host metabolism. Depressive-like behavior was studied using the forced-swim test on postnatal day (PND) 25 in rats either weaned on PND 21, or left with their mother until PND 25 (non-weaned). Non-weaned rats showed an increased immobility time consistent with a depressive phenotype. Fluorescence in situ hybridization showed non-weaned rats to harbor significantly lowered Clostridium histolyticum bacterial groups but exhibit marked stress-induced increases. Metabonomic analysis of urine from these animals revealed significant differences in the metabolic profiles, with biochemical phenotypes indicative of depression in the non-weaned animals. In addition, non-weaned rats showed resistance to stress-induced modulation of oxytocin receptors in amygdala nuclei, which is indicative of passive stress-coping mechanism. We conclude that delaying weaning results in alterations to the gut microbiota and global metabolic profiles which may contribute to a depressive phenotype and raise the issue that mood disorders at early developmental ages may reflect interplay between mammalian host and resident bacteria