80,802 research outputs found
Structure, mechanical properties and acoustic emissions of starch extrudates
Imperial Users onl
Introduction to Library Trends 52 (2) 2003: Organizing the Internet
published or submitted for publicatio
An Introduction to Gauge Gravity Duality and Its Application in Condensed Matter
The past few years have witnessed a remarkable crossover of string
theoretical ideas from the abstract world of geometrical forms to the concrete
experimental realm of condensed matter physics. The basis for this ---
variously known as holography, the AdS/CFT correspondence or gauge-gravity
duality --comes from notions right at the cutting edge of string theory.
Nevertheless, the insights afforded can often be expressed in ways very
familiar to condensed matter physicists, such as relationships between response
functions and new sum rules.
The aim of this short, introductory review is to survey the ideas
underpinning this crossover, in a way that -- as far as possible -- strips them
of sophisticated mathematical formalism, whilst at the same time retaining
their fundamental essence. I will sketch the areas in which progress has been
made to date and highlight where the challenges and open questions lie.
Finally, I will attempt to give a perspective upon these ideas. What
contribution can we realistically expect from this approach and how might it be
accommodated into the canon of condensed matter theory? Inevitably, any attempt
to do this in such a rapidly evolving field will be superseded by events.
Nevertheless, I hope that this will provide a useful way to think about
gauge-gravity duality and the uncharted directions in which it might take us.Comment: Unedited version of article published in Contemporary Physics.
Intended for advanced final-year undergraduate
Search for Pair Production of Supersymmetric Top Quarks Mimicking Standard Model Top Event Signatures at CDF
We present results of the search for the super-symmetric partner of the top
quark, the stop quark, decaying to a b-quark and chargino with the subsequent
chargino decay into a neutralino, lepton and neutrino. Using the data sample
corresponding to 2.7 inv fb of integrated luminosity, collected with the CDF
Detector of the Tevatron collider, we reconstruct the stop mass of candidate
events and set 95% C. L. upper limits on masses of the stop quark, chargino and
neutralino and the branching ratio of chargino to neutralino+lepton+neutrino.Comment: ICHEP08 poster, Philadelphia, USA, July 2008. 3 pages, LaTeX, 3
figure
Is Unemployment Good for the Environment?
Environmental quality is a public good, potentially impacted by everybody. Individual level pro-environmental behavior affects environmental quality in the aggregate. Therefore, it is important to understand what causes individual’s pro-environmental behaviors to change. We quantify the causal effect of one determinant, unemployment, using an EU-27 population representative Eurobarometer survey. Drawing on results from the theory of the private provision of public goods, and recognizing that unemployment decreases income and the opportunity cost of time, we formulate testable predictions that unemployment will decrease the extent of pro-environmental behaviors that require monetary contributions and increase the extent of pro-environmental behaviors that mainly require time/effort. Instrumental variables regressions provide empirical evidence to support these hypotheses. Changes in the unemployment rate within a sub-national region provide the exogenous variation needed to identify the causal effect. Several supplemental questions on the survey provide evidence that environmental issues lose saliency and economic issues gain saliency when one becomes unemployed, suggesting that interested parties may wish to emphasize cost savings of pro-environmental behavior rather than environmental benefits during times of increased unemployment
(WP 2015-02) Is Unemployment Good for the Environment?
Environmental quality is a public good, potentially impacted by everybody. Individual level pro-environmental behavior affects environmental quality in the aggregate. Therefore, it is important to understand what causes individual’s pro-environmental behaviors to change. We quantify the causal effect of one determinant, unemployment, using an EU-27 population representative Eurobarometer survey. Drawing on results from the theory of the private provision of public goods, and recognizing that unemployment decreases income and the opportunity cost of time, we formulate testable predictions that unemployment will decrease the extent of pro-environmental behaviors that require monetary contributions and increase the extent of pro-environmental behaviors that mainly require time/effort. Instrumental variables regressions provide empirical evidence to support these hypotheses. Changes in the unemployment rate within a sub-national region provide the exogenous variation needed to identify the causal effect. Several supplemental questions on the survey provide evidence that environmental issues lose saliency and economic issues gain saliency when one becomes unemployed, suggesting that interested parties may wish to emphasize cost savings of pro-environmental behavior rather than environmental benefits during times of increased unemployment
Heterogeneity in the Preferences and Pro-Environmental Behavior of College Students: The Effects of Years on Campus, Demographics, and External Factors
Models from several social science fields have identified factors that lead to pro-environmental behavior. This research builds on those models by analyzing a survey completed by over 500 undergraduates at a US liberal arts university to examine the characteristics of students that are associated with more environmentally friendly behavior and quantify the desirability of different environmental initiatives. There is evidence that the probability of pro-environmental behavior substantially increases with each additional year that a student spends on campus. The magnitude of the effect is between 4 and 10 percentage points per year, depending on the specific behavior and empirical model. This contribution suggests that higher education impacts pro-environmental behavior and supports the notion that higher education institutions can play an important role in making societies more sustainable. Further, evidence is presented to suggest that this increase in pro-environmental behavior over one\u27s college career is due to factors outside of the formal curriculum. This study also finds that females and ethnic/racial minorities engage in significantly higher levels of green behavior including recycling and double-sided printing. On average, students prefer sustainability initiatives related to energy conservation and recycling to other environmental programs but there is a great deal of heterogeneity in these preferences
The Archer-Shaw Social Security Plan: Laying the Groundwork for Another S&L Crisis
The Social Security reform plan proposed by Reps. Bill Archer (R-Tex.) and Clay Shaw (R-Fla.), chairmen, respectively, of the House Ways and Means Committee and its Subcommittee on Social Security, is a compromise between a Clinton administration plan to let the government invest workers' payroll taxes in the market and congressional proposals to let individuals invest their payroll taxes in personal market-based accounts. Government investment has been criticized for the possibility of political influence on investment decisions, while personal accounts face attack for making individuals shoulder the burden of market risk. The Archer-Shaw plan is an attempt to satisfy critics of both approaches. The Archer-Shaw plan would let individuals make investment decisions, thereby reducing the likelihood of political influence, but the government would be required to protect workers against any losses. The plan's proposal to privatize profit and socialize risk resembles the incentive structure that led to the 1980s savings and loan crisis, which cost taxpayers hundreds of billions of dollars. That incentive structure creates what economists call "moral hazard" and could again lead to large taxpayer liabilities if allowed to take root in the Social Security system
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