Mira variables: An informal review

The structure of the Mira variables is discussed with particular emphasis on the extent of their observable atmospheres, the various methods for measuring the sizes of these atmospheres, and the manner in which the size changes through the cycle. The results obtained by direct, photometric and spectroscopic methods are compared, and the problems of interpretation are addressed. Also, a simple model for the atmospheric structure and motions of Miras based on recent observations of the doubling of infrared molecualr times is described. This model, consisting of two atmospheric layers plus a circumstellar shell, provides a physically plausible picture of the atmosphere which is consistent with the photometrically measured magnitude and temperature variations as well as the spectroscopic data

Technology strategies for low-carbon economic growth: a general equilibrium assessment

This paper investigates the potential for developing countries to mitigate greenhouse gas emissions without slowing their expected economic growth. A theoretical frame- work is developed that unifies bottom-up marginal abatement cost curves and partial equilibrium techno-economic simulation modeling with computational general equilibrium (CGE) modeling. The framework is then applied to engineering assessments of energy efficiency technology deployments in Armenia and Georgia. The results facilitate incorporation of bottom-up technology detail on energy-efficiency improvements into a CGE simulation of the economy-wide economic costs and mitigation benefits of technology deployment policies. Low-carbon growth trajectories are feasible in both countries, enabling reductions of up to 4 percent of baseline emissions while generating slight increases in GDP (1 percent in Armenia and 0.2 percent in Georgia). The results demonstrate how MAC curves can paint a misleading picture of the true potential for both abatement and economic growth when technological improvements operate within a system of general equilibrium interactions, but also highlight how using their underlying data to identify technology options with high opportunity cost elasticities of productivity improvement can lead to more accurate assessments of the macroeconomic consequences of technology strategies for low-carbon growth.http://documents.worldbank.org/curated/en/279241468256026769/Technology-strategies-for-low-carbon-economic-growth-a-general-equilibrium-assessmentPublished versio

Unification of step bunching phenomena on vicinal surfaces

We unify step bunching (SB) instabilities occurring under various conditions on crystal surfaces below roughening. We show that when attachment-detachment of atoms at step edges is the rate-limiting process, the SB of interacting, concentric circular steps is equivalent to the commonly observed SB of interacting straight steps under deposition, desorption, or drift. We derive a continuum Lagrangian partial differential equation, which is used to study the onset of instabilities for circular steps. These findings place on a common ground SB instabilities from numerical simulations for circular steps and experimental observations of straight steps

Notes on the early-type components of W Cep, o Cet, CH Cyg, AR Mon, and BL Tel

Low resolution IUE spectra in both spectral regions are used to clarify the nature of the warmer components of several binary systems. The W Cep, the primary of which is a luminous K-type supergiant, shows an ultraviolet absorption spectrum of type B0 or B1; this system is heavily reddened. The hot companion of Mira (o Cet) is surprisingly faint in the short wavelength region, but it excites a rich emission spectrum from the surrounding gas. The ultraviolet active M7 giant CH Cyg is shown to be a binary with a hot companion. This system was also observed at high resolution and shows variable Fe II emission and well-separated circumstellar and interstellar absorptions within the broad Mg II emission profiles. The eclipsing binaries AR Mon and BL Tel are shown not to have hot companions

Cities, traffic, and CO2: A multidecadal assessment of trends, drivers, and scaling relationships

Emissions of CO2 from road vehicles were 1.57 billion metric tons in 2012, accounting for 28% of US fossil fuel CO2 emissions, but the spatial distributions of these emissions are highly uncertain. We develop a new emissions inventory, the Database of Road Transportation Emissions (DARTE), which estimates CO2 emitted by US road transport at a resolution of 1 km annually for 1980-2012. DARTE reveals that urban areas are responsible for 80% of on-road emissions growth since 1980 and for 63% of total 2012 emissions. We observe nonlinearities between CO2 emissions and population density at broad spatial/temporal scales, with total on-road CO2 increasing nonlinearly with population density, rapidly up to 1,650 persons per square kilometer and slowly thereafter. Per capita emissions decline as density rises, but at markedly varying rates depending on existing densities. We make use of DARTE's bottom-up construction to highlight the biases associated with the common practice of using population as a linear proxy for disaggregating national- or state-scale emissions. Comparing DARTE with existing downscaled inventories, we find biases of 100% or more in the spatial distribution of urban and rural emissions, largely driven by mismatches between inventory downscaling proxies and the actual spatial patterns of vehicle activity at urban scales. Given cities' dual importance as sources of CO2 and an emerging nexus of climate mitigation initiatives, high-resolution estimates such as DARTE are critical both for accurately quantifying surface carbon fluxes and for verifying the effectiveness of emissions mitigation efforts at urban scales.https://doi.org/10.1073/pnas.1421723112Published versio

Optimal two-stage filtering of elastograms

In ultrasound elastography, tissue axial strains are obtained through the differentiation of measured axial displacements. However, during the measurement process, the displacement signals are often contaminated with de-correlation noise caused by changes in the speckle pattern in the tissue. Thus, the application of the gradient operator on the displacement signals results in the presence of amplified noise in the axial strains, which severely obscures the useful information. The use of an effective denoising scheme is therefore imperative. In this paper, a method based on a two-stage consecutive filtering approach is proposed for the accurate estimation of axial strains. The presented method considers a cascaded system of a frequency filter and a time window, which are both designed such that the overall system operates optimally as a minimum variance estimator. Experimentation on simulated signals shows that the two-stage scheme employed in this study has good potential as a denoising method for ultrasound elastograms

Changing, priming, and acting on values: Effects via motivational relations in a circular model

Circular models of values and goals suggest that some motivational aims are consistent with each other, some oppose each other, and others are orthogonal to each other. The present experiments tested this idea explicitly by examining how value confrontation and priming methods influence values and value-consistent behaviors throughout the entire value system. Experiment 1 revealed that change in 1 set of social values causes motivationally compatible values to increase in importance, whereas motivationally incompatible values decrease in importance and orthogonal values remain the same. Experiment 2 found that priming security values reduced the better-than-average effect, but priming stimulation values increased it. Similarly, Experiments 3 and 4 found that priming security values increased cleanliness and decreased curiosity behaviors, whereas priming self-direction values decreased cleanliness and increased curiosity behaviors. Experiment 5 found that priming achievement values increased success at puzzle completion and decreased helpfulness to an experimenter, whereas priming with benevolence values decreased success and increased helpfulness. These results highlight the importance of circular models describing motivational interconnections between values and personal goals

Olympic Bids, Professional Sports, and Urban Politics: Four Decades of Stadium Planning in Detroit, 1936-1975

Between 1936 and 1975, political and business leaders in Detroit tried to gain support for the financing and construction of a municipal stadium. The stadium plan originated as part of an attempt to bring the Summer Olympics to the city. The municipal stadium was to serve as the main Olympic stadium and be used for a variety of events after the Olympics were finished. Later, after Detroit leaders gave up on the Olympics after several failed bids, the stadium plan evolved into a domed facility on the downtown riverfront for the Detroit Tigers and Detroit Lions, the city’s professional baseball and football teams. This dissertation examines the attempts of political and business leaders in Detroit to build a municipal sports stadium over the course of four decades in order to illuminate key themes in Detroit history. A thorough examination of the city’s efforts to build a multi-purpose stadium contributes to a more nuanced depiction of the city’s growth and decline throughout the twentieth century. Detroit became an important industrial center with the rise of the American automobile industry during the first half of the century and became a symbol of urban decay, racial warfare, and poverty by the 1980s. Exploring the municipal stadium story within this process of growth and decline will illuminate the history of urban politics, planning, race, and economics in Detroit. Several sport historians have analyzed the growth of professional sports as part of American urbanization and modernization, but few scholarly treatments have assessed the specific political and economic factors which led to the planning and construction of professional sports facilities and the cultural significance which city residents attached to those facilities. Most studies of urban sport history focus on major cities such as New York, Philadelphia, Boston, Los Angeles and Chicago, but they have neglected many cities of the industrial Midwest, including Detroit. An examination of the history of Detroit’s failed attempt to build a municipal stadium contributes to a clearer understanding about the role of urban politics, economics, and culture in the Rust Belt, particularly in terms of Detroit’s political economy during this period and the growing political and economic power of suburbs during the mid-twentieth century