Time maintenance of user clocks via the tracking and data relay satellite system

A system is described which uses the Tracking and Data Relay Satellite System (TDRSS) itself to compare the user satellite clock with a clock at the White Sands station that is referenced to Universal Time Coordinated (UTC). No command of the spacecraft by the system is required, and actual on-board clock corrections are made by the spacecraft control center at its discretion. Computer models were constructed using basic orbital parameters for user and TDRS satellites. With only first-order corrections and simple averaging techniques for constant clock rates, error measurement precision of better than one microsecond was obtained. More sophisticated computations should allow considerable improvement over this

An evaluation: The potential of discarded tires as a source of fuel

The destructive distillation of rubber tire samples was studied by thermogravimetry, differential scanning calorimetry, combustion calorimetry, and mass spectroscopy. The decomposition reaction was found to be exothermic and produced a mass loss of 65 percent. The gas evolution curves that were obtained indicate that a variety of organic materials are evolved simultaneously during the decomposition of the rubber polymer

A procedure used for a ground truth study of a land use map of North Alabama generated from LANDSAT data

A land use map of a five county area in North Alabama was generated from LANDSAT data using a supervised classification algorithm. There was good overall agreement between the land use designated and known conditions, but there were also obvious discrepancies. In ground checking the map, two types of errors were encountered - shift and misclassification - and a method was developed to eliminate or greatly reduce the errors. Randomly selected study areas containing 2,525 pixels were analyzed. Overall, 76.3 percent of the pixels were correctly classified. A contingency coefficient of correlation was calculated to be 0.7 which is significant at the alpha = 0.01 level. The land use maps generated by computers from LANDSAT data are useful for overall land use by regional agencies. However, care must be used when making detailed analysis of small areas. The procedure used for conducting the ground truth study together with data from representative study areas is presented

How political parties adjust to fixed voter opinions

We propose a new version of the spatial model of voting. Platforms of five parties are evolving in a two-dimensional landscape of political issues so as to get maximal numbers of voters. For a Gaussian landscape the evolution leads to a spatially symmetric state, where the platform centers form a pentagon around the Gaussian peak. For a bimodal landscape the platforms located at different peaks get different numbers of voters.Comment: 8 pages, 3 figures. Accepted in Int. J. Modern Phys.

A survey of weather information possessed by thirty-two pupils randomly selected from sixth and eleventh grades and from special classes

Thesis (Ed.M.)--Boston Universit

Simulation of Yield and Environmental Impacts of Wheat after Rice in Bangladesh and Australia

CERES-wheat and SWAGMAN Destiny models, respectively, were used to estimate the optimum time of sowing, and trade-off between yield and net recharge of the watertable, for wheat grown after rice in northern Bangladesh and southern NSW, Australia. Simulated wheat yields in Bangladesh, for sowings from Sept to Jan, with two supplemental irrigations, ranged from 0.4 to 4.6 t/ha. November-sown crops yielded more than the earlier- or later-sown crops due to reduced water and heat stress during grain filling. In Australia, simulated yields of non-irrigated wheat were always greater for April than June sowings due to less water deficit at the end of the season. With an initial shallow (0.5 m), fresh (1 dS/m) watertable, simulated yields usually exceeded 3 t/ha, and declined as watertable salinity increased. Nonirrigated wheat almost always lowered the watertable. Frequent irrigation increased simulated yields to 5-6 t/ha, regardless of initial conditions and sowing date, but this was at the cost of decreased discharge or increased recharge leading to rising watertables

The declining representativeness of the British party system, and why it matters

In a recent article, Michael Laver has explained ‘Why Vote-Seeking Parties May Make Voters Miserable’. His model shows that, while ideological convergence may boost congruence between governments and the median voter, it can reduce congruence between the party system and the electorate as a whole. Specifically, convergence can increase the mean distance between voters and their nearest party. In this article we show that this captures the reality of today’s British party system. Policy scale placements in British Election Studies from 1987 to 2010 confirm that the pronounced convergence during the past decade has left the Conservatives and Labour closer together than would be optimal in terms of minimising the policy distance between the average voter and the nearest major party. We go on to demonstrate that this comes at a cost. Respondents who perceive themselves as further away from one of the major parties in the system tend to score lower on satisfaction with democracy. In short, vote-seeking parties have left the British party system less representative of the ideological diversity in the electorate, and thus made at least some British voters miserable

Place matters: but does local leadership?

The arrival of New Labour into Government witnessed the prominent re-emergence of place onto the policy agenda. This heralded a range of area-based-initiatives designed to both tackle neighbourhood forms of deprivation and to re-establish a sense of identity and connection between individuals and their local community. In terms of place-making, effective and inclusive participation, representation and leadership were all identified as prerequisites for the creation of sustainable communities . But how important is local leadership and strategic vision within local public service organisations in achieving the desired place-making outcomes? This paper examines the extent to which local leadership and strategic vision represents a significant factor in promoting higher levels of satisfaction, belonging, cohesion and participation across single tier councils in England. The ensuing empirical evidence raises significant questions not only about the importance of local leadership in place-making, but also the environmental and organizational factors that shape local places

Toward a Theory of Innovation

The purpose of this article is to eliminate further conceptual obstacles to the develop ment of a workable theory of innovation and to move toward a better theoretic statement. The approach to overcoming the conceptual problems centers primarily around four ideas: (1) building a theory around the "innovation decision" as the unit of analysis, rather than either innovations or adopters: (2) lifting the level of general ity of independent variables so that a great deal of statistical interaction is avoided; (3) splitting the act of innovation into two stages, diffusion and adoption, to eliminate the confounding effects of time of awareness in studies of innovation; (4) introducing the idea of a "fair-trial point" into the conceptualization of innovation, solving sev eral additional problems at once.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68286/2/10.1177_009539977901000401.pd

Ab initio studies of phonon softening and high pressure phase transitions of alpha-quartz SiO2

Density functional perturbation theory calculations of alpha-quartz using extended norm conserving pseudopotentials have been used to study the elastic properties and phonon dispersion relations along various high symmetry directions as a function of bulk, uniaxial and non-hydrostatic pressure. The computed equation of state, elastic constants and phonon frequencies are found to be in good agreement with available experimental data. A zone boundary (1/3, 1/3, 0) K-point phonon mode becomes soft for pressures above P=32 GPa. Around the same pressure, studies of the Born stability criteria reveal that the structure is mechanically unstable. The phonon and elastic softening are related to the high pressure phase transitions and amorphization of quartz and these studies suggest that the mean transition pressure is lowered under non-hydrostatic conditions. Application of uniaxial pressure, results in a post-quartz crystalline monoclinic C2 structural transition in the vicinity of the K-point instability. This structure, intermediate between quartz and stishovite has two-thirds of the silicon atoms in octahedral coordination while the remaining silicon atoms remain tetrahedrally coordinated. This novel monoclinic C2 polymorph of silica, which is found to be metastable under ambient conditions, is possibly one of the several competing dense forms of silica containing octahedrally coordinated silicon. The possible role of high pressure ferroelastic phases in causing pressure induced amorphization in silica are discussed.Comment: 17 pages, 8 figs., 8 Table