A new renormalization group approach for systems with strong electron correlation

The anomalous low energy behaviour observed in metals with strong electron correlation, such as in the heavy fermion materials, is believed to arise from the scattering of the itinerant electrons with low energy spin fluctuations. In systems with magnetic impurities this scattering leads to the Kondo effect and a low energy renormalized energy scale, the Kondo temperature $T_{\rm K}$. It has been generally assumed that these low energy scales can only be accessed by a non-perturbative approach due to the strength of the local inter-electron interactions. Here we show that it is possible to circumvent this difficulty by first suppressing the spin fluctuations with a large magnetic field. As a first step field-dependent renormalized parameters are calculated using standard perturbation theory. A renormalized perturbation theory is then used to calculate the renormalized parameters for a reduced magnetic field strength. The process can be repeated and the flow of the renormalized parameters continued to zero magnetic field. We illustrate the viability of this approach for the single impurity Anderson model. The results for the renormalized parameters, which flow as a function of magnetic field, can be checked with those from numerical renormalization group and Bethe ansatz calculations.Comment: 14 pages, 15 figure

Great East Japan Earthquake, JR East Mitigation Successes, and Lessons for California High-Speed Rail, MTI Report 12-37

California and Japan both experience frequent seismic activity, which is often damaging to infrastructure. Seismologists have developed systems for detecting and analyzing earthquakes in real-time. JR East has developed systems to mitigate the damage to their facilities and personnel, including an early earthquake detection system, retrofitting of existing facilities for seismic safety, development of more seismically resistant designs for new facilities, and earthquake response training and exercises for staff members. These systems demonstrated their value in the Great East Japan Earthquake of 2011 and have been further developed based on that experience. Researchers in California are developing an earthquake early warning system for the state, and the private sector has seismic sensors in place. These technologies could contribute to the safety of the California High-Speed Rail Authority’s developing system, which could emulate the best practices demonstrated in Japan in the construction of the Los Angeles-to-San Jose segment

The Role of Transportation in Campus Emergency Planning, MTI Report 08-06

In 2005, Hurricane Katrina created the greatest natural disaster in American history. The states of Louisiana, Mississippi and Alabama sustained significant damage, including 31 colleges and universities. Other institutions of higher education, most notably Louisiana State University (LSU), became resources to the disaster area. This is just one of the many examples of disaster impacts on institutions of higher education. The Federal Department of Homeland Security, under Homeland Security Presidential Directive–5, requires all public agencies that want to receive federal preparedness assistance to comply with the National Incident Management System (NIMS), which includes the creation of an Emergency Operations Plan (EOP). Universities, which may be victims or resources during disasters, must write NIMS–compliant emergency plans. While most university emergency plans address public safety and logistics management, few adequately address the transportation aspects of disaster response and recovery. This MTI report describes the value of integrating transportation infrastructure into the campus emergency plan, including planning for helicopter operations. It offers a list of materials that can be used to educate and inform campus leadership on campus emergency impacts, including books about the Katrina response by LSU and Tulane Hospital, contained in the report´s bibliography. It provides a complete set of Emergency Operations Plan checklists and organization charts updated to acknowledge lessons learned from Katrina, 9/11 and other wide–scale emergencies. Campus emergency planners can quickly update their existing emergency management documents by integrating selected annexes and elements, or create new NIMS–compliant plans by adapting the complete set of annexes to their university´s structures

The effect of spatial and temporal wet-troposphere fluctuations on connected element interferometry

Numerical integrations of the structure function of tropospheric inhomogeneities have been performed to assess the impact of water vapor fluctuations on connected element interferometry (CEI). The expectation value of the RMS troposphere error for a differential spacecraft-quasar observation is derived by integrating the spatial refractivity structure function along raypaths to both the spacecraft and quasar from two spatially separated sites. Correlations between the tropospheric conditions at the two sites, which can become significant for short baseline observations, are fully accounted for in this calculation. Temporal effects are treated by assuming a frozen-flow model in which a fixed spatial distribution blows over both sites. Two nominal observation scenarios are considered, along with variations to study the dependence of the resultant differential troposphere errors on baseline length, observation time, source separation angle, and elevation. Consecutive differential observations are found to be almost completely uncorrelated, implying that averaging many repeated differential observations can quickly reduce the troposphere error

Transportation, Terrorism and Crime: Deterrence, Disruption and Resilience

Abstract: Terrorists likely have adopted vehicle ramming as a tactic because it can be carried out by an individual (or “lone wolf terrorist”), and because the skills required are minimal (e.g. the ability to drive a car and determine locations for creating maximum carnage). Studies of terrorist activities against transportation assets have been conducted to help law enforcement agencies prepare their communities, create mitigation measures, conduct effective surveillance and respond quickly to attacks. This study reviews current research on terrorist tactics against transportation assets, with an emphasis on vehicle ramming attacks. It evaluates some of the current attack strategies, and the possible mitigation or response tactics that may be effective in deterring attacks or saving lives in the event of an attack. It includes case studies that can be used as educational tools for understanding terrorist methodologies, as well as ordinary emergencies that might become a terrorist’s blueprint

Handbook of Emergency Management For State-Level Transportation Agencies, MTI Report 09-10

The Department of Homeland Security has mandated specific systems and techniques for the management of emergencies in the United States, including the Incident Command System, the National Incident Management System, Emergency Operations Plans, Emergency Operations Centers, Continuity of Government Plans and Continuity of Operations Plans. These plans and systems may be applied to the state-level transportation agency�s disaster response systems to enhance efficiency and effectiveness. Specific guidance and management techniques are provided to aid emergency planning staff to create DHS-compliant systems

A forebody design technique for highly integrated bottom-mounted scramjets with application to a hypersonic research airplane

An inviscid technique for designing forebodies which produce uniformly precompressed flows at the inlet entrance for bottom-mounted scramjets has been developed so that geometric constraints resulting from design trade-offs can be effectively evaluated. The flow fields resulting from several forebody designs generated in support of a hypersonic research airplane conceptual design study have been analyzed in detail with three-dimensional characteristics calculations to verify the uniform flow conditions. For the designs analyzed, uniform flow is maintained over a wide range of flight conditions (Mach number equals 4 to 10; angle of attack equals 6 deg to 10 deg) corresponding to scramjet operation flight envelope of the research airplane

Analytical methods for bacterial kinetics studies

Methods utilize mathematical equations and models and specialized computer techniques. Techniques apply to food production, complex chemicals production, and polluted water purification