Ultracold chemical reactions of a single Rydberg atom in a dense gas

Within a dense environment ($\rho \approx 10^{14}\,$atoms/cm$^3$) at ultracold temperatures ($T < 1\,\mu{}\text{K}$), a single atom excited to a Rydberg state acts as a reaction center for surrounding neutral atoms. At these temperatures almost all neutral atoms within the Rydberg orbit are bound to the Rydberg core and interact with the Rydberg atom. We have studied the reaction rate and products for $nS$ $^{87}$Rb Rydberg states and we mainly observe a state change of the Rydberg electron to a high orbital angular momentum $l$, with the released energy being converted into kinetic energy of the Rydberg atom. Unexpectedly, the measurements show a threshold behavior at $n\approx 100$ for the inelastic collision time leading to increased lifetimes of the Rydberg state independent of the densities investigated. Even at very high densities ($\rho\approx4.8\times 10^{14}\,\text{cm}^{-3}$), the lifetime of a Rydberg atom exceeds $10\,\mu\text{s}$ at $n > 140$ compared to $1\,\mu\text{s}$ at $n=90$. In addition, a second observed reaction mechanism, namely Rb$_2^+$ molecule formation, was studied. Both reaction products are equally probable for $n=40$ but the fraction of Rb$_2^+$ created drops to below 10$\,$% for $n\ge90$.Comment: 13 pages, 13 figure

Review of California Wildfire Evacuations from 2017 to 2019

Between 2017 and 2019, California experienced a series of devastating wildfires that together led over one million people to be ordered to evacuate. Due to the speed of many of these wildfires, residents across California found themselves in challenging evacuation situations, often at night and with little time to escape. These evacuations placed considerable stress on public resources and infrastructure for both transportation and sheltering. In the face of these clear challenges, transportation and emergency management agencies across California have widely varying levels of preparedness for major disasters, and nearly all agencies do not have the public resources to adequately and swiftly evacuate all populations in danger. To holistically address these challenges and bolster current disaster and evacuation planning, preparedness, and response in California, we summarize the evacuations of eleven major wildfires in California between 2017 and 2019 and offer a cross-comparison to highlight key similarities and differences. We present results of new empirical data we collected via an online survey of individuals impacted by: 1) the 2017 October Northern California Wildfires (n=79), 2) the 2017 December Southern California Wildfires (n=226), and 3) the 2018 Carr Wildfire (n=284). These data reveal the decision-making of individuals in these wildfires including choices related to evacuating or staying, departure timing, route, sheltering, destination, transportation mode, and reentry timing. We also present results related to communication and messaging, non-evacuee behavior, and opinion of government response. Using the summarized case studies and empirical evidence, we present a series of recommendations for agencies to prepare for, respond to, and recover from wildfires

The multiple geographies of Peterloo and its impact in Britain

The Peterloo Massacre was more than just a Manchester event. The attendees, on whom Manchester industry depended, came from a large spread of the wider textile regions. The large demonstrations that followed in the autumn of 1819, protesting against the actions of the authorities, were pan-regional and national. The reaction to Peterloo established the massacre as firmly part of the radical canon of martyrdom in the story of popular protest for democracy. This article argues for the significance of Peterloo in fostering a sense of regional and northern identities in England. Demonstrators expressed an alternative patriotism to the anti-radical loyalism as defined by the authorities and other opponents of mass collective action.Peer reviewe

Spartan Daily, October 4, 2016

Volume 147, Issue 14https://scholarworks.sjsu.edu/spartan_daily_2016/1054/thumbnail.jp

The Cowl - v.82 - n.3 - Sep 21, 2017

The Cowl - student newspaper of Providence College. Volume 82, Number 3 - September 21, 2017. 24 pages

Trouble\u27s Clarion Call for Leaders: Jo Ann Robinson and the Montgomery Bus Boycott

Turbulent times are part of the human experience. They provide what Useem calls the leadership moment when one is given the opportunity to define who one is (1998). For Jo Ann Robinson, that leadership moment came personally in 1949, and publicly in 1955 when she transformed her trauma into a pro-social action of change (Williams and Allen, 2015). This article is a historical narrative inquiry into the life of Robinson who launched the Montgomery boycott and helped start the civil rights movement. The article tells the rest of the story beyond Parks and King, and explores the question: How did Robinson lead? With no authority, she empowered more than 50,000 African American to stand up and change their world