9,382 research outputs found
Tucker\u27s The end of the island: Finding life in the movements of human suffering, pain, and loss (Book Review)
Tucker, J. C. (2016). The end of the island: Finding life in the movements of human suffering, pain, and loss. Eugene, OR: Resource Publications. 159 pp. $22.00. ISBN 978149827906
Hill\u27s Dribble drabble: Process art experiences for young children (Book Review)
Hill, D. B. (2016). Dribble drabble: Process art experiences for young children. St. Paul, MN: Red Leaf Press. 106 pp. $15.95. ISBN 978160554528
The Evolution of Protoplanetary Disks Around Millisecond Pulsars: The PSR 1257 +12 System
We model the evolution of protoplanetary disks surrounding millisecond
pulsars, using PSR 1257+12 as a test case. Initial conditions were chosen to
correspond to initial angular momenta expected for supernova-fallback disks and
disks formed from the tidal disruption of a companion star. Models were run
under two models for the viscous evolution of disks: fully viscous and layered
accretion disk models. Supernova-fallback disks result in a distribution of
solids confined to within 1-2 AU and produce the requisite material to form the
three known planets surrounding PSR 1257+12. Tidal disruption disks tend to
slightly underproduce solids interior to 1 AU, required for forming the pulsar
planets, while overproducing the amount of solids where no body, lunar mass or
greater, exists. Disks evolving under 'layered' accretion spread somewhat less
and deposit a higher column density of solids into the disk. In all cases,
circumpulsar gas dissipates on year timescales, making
formation of gas giant planets highly unlikely.Comment: 16 pages, 17 figures, Accepted for publication in The Astrophysical
Journal (September 20, 2007 issue
Alien Registration- Currie, John T. (Wade, Aroostook County)
https://digitalmaine.com/alien_docs/32681/thumbnail.jp
Understanding Variations in Circularly Polarized Photoluminescence in Monolayer Transition Metal Dichalcogenides
Monolayer transition metal dichalcogenides are promising materials for
valleytronic operations. They exhibit two inequivalent valleys in the Brillouin
zone, and the valley populations can be directly controlled and determined
using circularly polarized optical excitation and emission. The
photoluminescence polarization reflects the ratio of the two valley
populations. A wide range of values for the degree of circularly polarized
emission, Pcirc, has been reported for monolayer WS2, although the reasons for
the disparity are unclear. Here we optically populate one valley, and measure
Pcirc to explore the valley population dynamics at room temperature in a large
number of monolayer WS2 samples synthesized via chemical vapor deposition.
Under resonant excitation, Pcirc ranges from 2% to 32%, and we observe a
pronounced inverse relationship between photoluminescence (PL) intensity and
Pcirc. High quality samples exhibiting strong PL and long exciton relaxation
time exhibit a low degree of valley polarization, and vice versa. This behavior
is also demonstrated in monolayer WSe2 samples and transferred WS2, indicating
that this correlation may be more generally observed and account for the wide
variations reported for Pcirc. Time resolved PL provides insight into the role
of radiative and non-radiative contributions to the observed polarization.
Short non-radiative lifetimes result in a higher measured polarization by
limiting opportunity for depolarizing scattering events
Interview with Kelly Currie by Brien Williams
Biographical NoteKelly T. Currie was born on September 11, 1963, in Lewistown, Montana, to Edmund and Bette Currie, and grew up in Farmington, Maine. His father was a professor at the University of Maine, Farmington and his mother was a nurse. He attended the University of Virginia and was graduated in 1986, serving a summer internship with Senator Mitchell’s office between his junior and senior year. In the fall of 1986, he worked on Jim Tierney’s Maine gubernatorial campaign. He joined Senator Mitchell’s Senate staff full-time in January of 1987 as a legislative correspondent dealing with finance, defense, and veterans’ affairs issues. He later transitioned to the position of deputy press secretary, focusing on the Maine press and Maine issues. At the time of this interview he was deputy chief of the Criminal Division of the U.S. Attorney’s Office for the eastern district of New York.
SummaryInterview includes discussion of: childhood and educational background; summer intern in Senator Mitchell’s office; legislative correspondent and issues; deputy press secretary; driving for Mitchell and talking sports; Senate majority leader race; 1992 presidential campaign; extensive description of the Northern Ireland peace process; Iran-Contra; Sharm-el Sheikh; 1988 Senate reelection campaign; the Maine press; and Mitchell’s sense of humor
How OECD policies affected Latin America in the 1980s
The authors assess the effects of OECD monetary and fiscal policies on Latin America by means of simulation studies using the LBS/NIESR Global Econometric Model and a new empirical model of Latin America. The Latin American model pays special attention to the supply-side determination of natural rate of output and to the effects of asset accumulation. The Latin American model and its properties are presented by both empirical simulations and by means of a simple analytical representation. This model of Latin America is used in conjunction with the Global Econometric Model to study the macroeconomic interactions between Latin America and the rest of the world. The assumption in policy simulations is that G-3 exchange rates are forward-looking while Latin America pegs its currency to the U.S. dollar. It is postulated that Latin American fiscal policy adjustments target a baseline current account balance, in the face of external shocks. The simulation results reflect a number of important international links, which can be quantified as multiplier properties of the linked system of models. A permanent 5 percent contraction in the U.S. money supply induces a contraction of about the same order in Latin American GDP and capital stock. This is caused by higher U.S. interest rates and diminished Latin American competitiveness in third markets, reinforcing the fall in U.S. demand. Similarly, a combined monetary contraction in G-3 countries on a permanent footing - a contraction like the one in 1978-80 (U.S., 5.2 percent, German, 11.9 percent, and Japanese, 1.7 percent) hurts Latin America. Latin American GDP remains depressed by 4 percent and capital stock by 5 percent even after 10 years. The effects of negative income and interest rates emanating from G-3 countries are mutually reinforcing. U.S. fiscal expansion equal to 1 percent of baseline GDP, sustained over five years, transmits negatively to Latin America, where GDP falls 0.6 percent in the short run and remains depressed by 0.3 percent even after 10 years. The negative effects of higher interest rates and diminished competitiveness dominate the positive effects (which are short-lived) of expanded U.S. demand for Latin American exports. Similarly, G-3 fiscal spending shocks, which aregradually built up over five years, then reversed the next two years, have a mild negative effect on Latin American GDP. The G-3 fiscal shocks administered were set to their actual magnitudes relative to baseline GDP, as observed in 1980-85 (U.S. expansion of 3.5 percent but contraction in German and Japanese spending of 4.4 percent and 3.5 percent, respectively). Latin American GDP is lower than baseline GDP by 0.5 percent when the shocks peak at the end of five years, but continues to remain depressed 0.3 percent by the end of 10 years. The simulated effects of G-3 monetary and fiscal policies, with the shocks constructed to reflect their actual sizes in the early 1980s, suggest that Latin America's adjustment problems in that period cannot be attributed to G-3 fiscal imbalances that arose because of failures of G-3 fiscal policy coordination. But concerted G-3 monetary contraction in response to the second oil shock imposed heavy costs on Latin America; without it, Latin American GDP would have been 5 percent higher in the 1980s.Fiscal&Monetary Policy,Macroeconomic Management,Economic Theory&Research,Environmental Economics&Policies,Economic Stabilization
Contour measurement system
A measurement system for measuring the departures from a straight line of discrete track sections of a track along a coal face in a mine employing a vehicle having a pair of spaced wheel assemblies which align with the track is presented. A reference arm pivotally connects between the wheel assemblies, and there is indicating means for measuring the angle of pivot between the arm and each of the wheel assemblies. The length of the device is less than the length of a track section, and thus when one of the wheel assemblies is on one track section and one is on an adjoining track section, the sum of the indicated angles will be indicative of the angle between track sections. Thus, from the length of a track section and angle, the departure of each track section from the line may be calculated
- …