Problems in J times B plasma acceleration Semiannual progress report

Shock tube accelerator, heat transfer gauge, homopolar accelerator theory, and transport effects in boundary layers in plasma

Metal shearing energy absorber

A metal shearing energy absorber is described. The absorber is composed of a flat thin strip of metal which is pulled through a slot in a cutter member of a metal, harder than the metal of the strip. The slot's length, in the direction perpendicular to the pull direction, is less than the strip's width so that as the strip is pulled through the slot, its edges are sheared off, thereby absorbing some of the pulling energy. In one embodiment the cutter member is a flat plate of steel, while in another embodiment the cutter member is U-shaped with the slot at its base

Self heating and nonlinear current-voltage characteristics in bilayer graphene

We demonstrate by experiments and numerical simulations that the low-temperature current-voltage characteristics in diffusive bilayer graphene (BLG) exhibit a strong superlinearity at finite bias voltages. The superlinearity is weakly dependent on doping and on the length of the graphene sample. This effect can be understood as a result of Joule heating. It is stronger in BLG than in monolayer graphene (MLG), since the conductivity of BLG is more sensitive to temperature due to the higher density of electronic states at the Dirac point.Comment: 9 pages, 7 figures, REVTeX 4.

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https://digitalcommons.library.umaine.edu/mmb-vp/3352/thumbnail.jp

Species Profiles: Life Histories and Environmental Requirements of Coastal Fishes and Invertebrates (Mid-Atlantic): Alewife/Blueback Herring

This profile covers life history and environmental requirements of both alewife (Alosa pseudoharengus) and blueback herring (Alosa aestivalis), since their distribution is overlapping and their morphology, ecological role, and environmental requirements are similar. The alewife is an anadromous species found in riverine, estuarine, and Atlantic coastal habitats, depending on life cycle stage, from Newfoundland (Winters et al. 1973) to Soutn Carolina (Berry 1964). Landlocked populations are i n the Great Lakes, Finger Lakes, and many other freshwater lakes (Bigelow and Sch roeder 1953; Scott and Crossman 1973). The blueback herring is an anadromous species found in riverine, estuarine, and Atlantic coastal habitats, depending on life stage cycle, from Nova Scotia to the St. Johns River, Florida (Hildebrand 1963

Ag econ angst crisis revisited: a rejoinder

Poverty reduction has been an underlying goal of governments and the development community since the Second World War, but it was the 1973 Nairobi address of Robert S. McNamara, then President of the World Bank, that created a new commitment to directly address poverty reduction in the quest for development (McNamara 1973). More than half a century after the war and close to 30 years after Robert McNamara’s speech, poverty is still rampant in many parts of the globe. Reflections on why this scourge remains, and what we as agricultural economists can do about it, were the driving forces behind our paper with the late John L. Dillon entitled ‘Agricultural economists and world poverty: progress and prospects’ (Rola-Rubzen et al. 2001). The part of our paper that Johnson, Rossmiller and Sandiford-Rossmiller (JRS) have reacted to was deliberately provocative to stimulate thinking on ways to combat poverty. We are pleased that someone has taken the bait. As the two surviving authors, we find ourselves in agreement with much that JRS have written. However, in preparing this rejoinder we have sadly missed John Dillon, especially his broad international experience. We note that in several respects JRS amplify and support some of our points, as well as adding a new perspective of their own, dealing with the new institutional economics. We find it hard to work out just where they differ from us.Teaching/Communication/Extension/Profession,

Air pollution from aircraft

A series of fundamental problems related to jet engine air pollution and combustion were examined. These include soot formation and oxidation, nitric oxide and carbon monoxide emissions mechanisms, pollutant dispension, flow and combustion characteristics of the NASA swirl can combustor, fuel atomization and fuel-air mixing processes, fuel spray drop velocity and size measurement, ignition and blowout. A summary of this work, and a bibliography of 41 theses and publications which describe this work, with abstracts, is included

Status of the CMS electromagnetic calorimeter

CMSThe CMS electromagnetic calorimeter will provide excellent performance (in energy and position measurements) in a very hostile environnment (radiation beam crossing rates). It consists of a barrel made of 61200 lead tungstate crystals each read out by two avalanche photodiodes and of two end caps with 14488 crystals read out by vacuum phototriodes. In early 2002, the front-end electronics was redesigned and is now base on trigger towers that calculate the trigger primitives on detector at each bunch crossing and transmit raw data upon level-1 trigger acceptance. The status of the calorimeter construction is presented, as well as results of beam tests performed in 2003 using the new electronics scheme which confirm that the design performance can be reached

Quantum dynamics of a dc-SQUID coupled to an asymmetric Cooper pair transistor

We present a theoretical analysis of the quantum dynamics of a superconducting circuit based on a highly asymmetric Cooper pair transistor (ACPT) in parallel to a dc-SQUID. Starting from the full Hamiltonian we show that the circuit can be modeled as a charge qubit (ACPT) coupled to an anharmonic oscillator (dc-SQUID). Depending on the anharmonicity of the SQUID, the Hamiltonian can be reduced either to one that describes two coupled qubits or to the Jaynes-Cummings Hamiltonian. Here the dc-SQUID can be viewed as a tunable micron-size resonator. The coupling term, which is a combination of a capacitive and a Josephson coupling between the two qubits, can be tuned from the very strong- to the zero-coupling regimes. It describes very precisely the tunable coupling strength measured in this circuit and explains the 'quantronium' as well as the adiabatic quantum transfer read-out.Comment: 20 page