17,305 research outputs found

    MST radar detection of middle atmosphere tides

    Get PDF
    Meteorological and dynamical requirements pertaining to the specification of middle atmosphere tides by the MST radar technique are outlined. Major issues addressed include: (1) the extraction of tidal information from measurements covering a fraction of a day; (2) the ramifications of transient effects (tidal variability) on the determination and interpretation of tides; (3) required temporal and spatial resolutions and; (4) global distributions of MST radars, so as to complement existing MST, meteor wind, and partial reflection drift radar locations

    Theta Graph Designs

    Get PDF
    We solve the design spectrum problem for all theta graphs with 10, 11, 12, 13, 14 and 15 edges

    The Atmospheric Tides Middle Atmosphere Program (ATMAP)

    Get PDF
    Atmospheric tides, oscillations in meteorological fields occurring at subharmonics of a solar or lunar day, comprise a major component of middle atmosphere global dynamics. The purpose of the 1982 to 1986 Atmospheric Tides Atmosphere Program (ATMAP) was to foster an interaction between experimentalists, data analysts, and theoreticians and modelers, in order to better understand the physical mechanisms governing tides and their relationships to other scales of motion, and to thereby explain features of observed tidal structures in the mesosphere and lower thermosphere. The ATMAP consisted of seven observational campaigns, five workshops and a climatological study. A historical perspective is provided along with a summary of major results, conclusions, and recommendations for future study which have emerged from the ATMAP

    Why do foreigners invest in the United States?

    Get PDF
    Why are foreigners willing to invest almost $2 trillion per year in the United States? The answer affects if the existing pattern of global imbalances can persist and if the United States can continue to finance its current account deficit without a major change in asset prices and returns. This paper tests various hypotheses and finds that standard portfolio allocation models and diversification motives are poor predictors of foreign holdings of U.S. liabilities. Instead, foreigners hold greater shares of their investment portfolios in the United States if they have less-developed financial markets. The magnitude of this effect decreases with income per capita. Countries with fewer capital controls and greater trade with the United States also invest more in U.S. equity and bond markets, and there is no evidence that foreigners invest in the United States based on diversification motives. The empirical results showing a primary role of financial market development in driving foreign purchases of U.S. portfolio liabilities supports recent theoretical work on global imbalances.

    One Cost of the Chilean Capital Controls: Increased Financial Constraints for Smalles Traded Firms

    Get PDF
    There is growing support for taxes on short-term capital inflows in emerging markets, such as the encaje adopted by Chile from 1991-98. Previous empirical assessments of the encaje conclude that it may have generated some small economic benefits, such as shifting the composition of capital inflows to a longer maturity, but no significant economic costs. Managers of small and medium-sized companies in Chile, however, claim that the encaje made it substantially more difficult to obtain financing for productive investment. This paper assesses whether the Chilean capital controls increased financial constraints for different-sized, publicly-traded firms. It uses two different testing methodologies: a Tobin's q and Euler-equation framework. Results indicate that during the encaje, smaller traded firms in Chile experienced significant financial constraints and these constraints decreased as firm size increased. Both before and after the encaje, however, no group of traded firms experienced significant financial constraints, and there is no relationship between firm size and financial constraints. Although Chilean-style capital controls may also yield benefits encaje could be particularly important in emerging markets where smaller firms can be valuable sources of job creation and economic growth.

    Tidal coupling with the lower atmosphere (invited review)

    Get PDF
    The various ways are reviewed in which propagating tidal components excited in the mesophere and below affect the structure of the thermosphere and ionosphere above 100 km. Dynamo effects are not treated here. The physical processes affecting the propagation of upward propagating tides are examined and how they are interrelated in the context of a numerical model. Propagating diurnal and semidiurnal tides which reach thermospheric heights are excited primarily by insolation absorption by tropospheric water vapor (0 to 5 km) and stratospheric/mesospheric ozone (40 to 60 km), respectively. Simulation of these oscillations requires consideration of mean zonal winds and meridional temperature gradients, and the damping effects of turbulent and molecular dissipation, radiative cooling, and ion drag. These effects must be considered on a spherical rotating atmosphere extending from the ground to above 300 km, as they are in the model developed by Forbes depicted schematically

    Capital Controls: Mud in the Wheels of Market Discipline

    Get PDF
    Widespread support for capital account liberalization in emerging markets has recently shifted to skepticism and even support for capital controls in certain circumstances. This sea-change in attitudes has been bolstered by the inconclusive macroeconomic evidence on the benefits of capital account liberalization. There are several compelling reasons why it is difficult to measure the aggregate impact of capital controls in very different countries. Instead, a new and more promising approach is more detailed microeconomic studies of how capital controls have generated specific distortions in individual countries. Several recent papers have used this approach and examined very different aspects of capital controls from their impact on crony capitalism in Malaysia and on financing constraints in Chile, to their impact on US multinational behavior and the efficiency of stock market pricing. Each of these diverse studies finds a consistent result: capital controls have significant economic costs and lead to a misallocation of resources. This new microeconomic evidence suggests that capital controls are not just sand', but rather mud in the wheels' of market discipline.

    Clearwing Moths Captured by Ultraviolet Light Traps in Southern Ohio (Lepidoptera: Sesiidae)

    Get PDF
    Trapping with ultraviolet light in mixed-oak forests of Lawrence and Vinton Counties, Ohio in 1995 and 1996 yielded 46 Synanthedon acerni and four Synanthedon arkansasensis, a clearwing moth record new for the state

    Pitch Mass Borer, a New Clearwing Moth Record for Ohio (Lepidoptera: Sesiidae)

    Get PDF
    We report the Pitch Mass Borer clearwing moth, Synanthedon pini, from Vinton Furnace Experimental Forest, Dundas, Vinton County, Ohio, the first record for this state. A mature larva and two pupae were excised from resin masses of Scrub Pine, Pinus virginiana, a new host record, in early May 1999

    Management factors affecting the use of pasture by table chickens in extensive production systems

    Get PDF
    Whether chickens will make proper use of pasture is a problem experienced by producers of free-range and organic chickens. The aims of this project are to identify husbandry techniques and aspects of system design that encourage good pasture use. Two studies have been conducted comprising a winter and a summer flock. The aim of the winter flock was to examine the effect of outdoor artificial shelter on pasture usage. This was done for female Ross 308 birds grown to day 56, and ISA 657 birds grown to day 81. In summer, ISA 657 birds were grown to day 81. Treatments were either standard or enriched brooding, with pasture only or enriched pasture. Standard brooding was in a controlled environment house until day 42. Enriched brooding was in naturally ventilated houses in which birds had sight of pasture from an early age and access from day 21. Enriched pasture included artificial shelter, with straw bales and a conifer “wigwam” used to provide natural shelter. Chickens may be encouraged to go outdoors by brooding in a less “controlled” environment than that used for intensive broilers, and by allowing access to pasture when young. However, mortality was higher. Conifer wigwams may offer a means for more even use of pasture and better distribution of droppings
    corecore