9,338 research outputs found
Discriminator aided phase lock acquisition for suppressed carrier signals
A discriminator aided technique for acquisition of phase lock to a suppressed carrier signal utilizes a Costas loop which is initially operated open loop and control voltage for its VCXO is derived from a phase detector that compares the VCXO to a reference frequency thus establishing coarse frequency resolution with the received signal. Then the Costas loop is closed with the low-pass filter of the channel having a bandwidth much greater (by a factor of about 10) than in the I channel so that a frequency discriminator effect results to aid carrier resolution. Finally, after carrier acquisition, the Q-channel filter of the Costas loop is switched to a bandwidth substantially equal to that of the I-channel for carrier tracking
Investigation of semiconductor clad optical waveguides
A variety of techniques have been proposed for fabricating integrated optical devices using semiconductors, lithium niobate, and glasses as waveguides and substrates. The use of glass waveguides and their interaction with thin semiconductor cladding layers was studied. Though the interactions of these multilayer waveguide structures have been analyzed here using glass, they may be applicable to other types of materials as well. The primary reason for using glass is that it provides a simple, inexpensive way to construct waveguides and devices
Low-temperature balloon battery Final report, 29 May - 29 Sep. 1968
Development of low temperature electric batteries suitable for balloon
The Rachel Carson Letters and the Making of Silent Spring
Environment, conservation, green, and kindred movements look back to Rachel Carson’s 1962 book Silent Spring as a milestone. The impact of the book, including on government, industry, and civil society, was immediate and substantial, and has been extensively described; however, the provenance of the book has been less thoroughly examined. Using Carson’s personal correspondence, this paper reveals that the primary source for Carson’s book was the extensive evidence and contacts compiled by two biodynamic farmers, Marjorie Spock and Mary T. Richards, of Long Island, New York. Their evidence was compiled for a suite of legal actions (1957-1960) against the U.S. Government and that contested the aerial spraying of dichlorodiphenyltrichloroethane (DDT). During Rudolf Steiner’s lifetime, Spock and Richards both studied at Steiner’s Goetheanum, the headquarters of Anthroposophy, located in Dornach, Switzerland. Spock and Richards were prominent U.S. anthroposophists, and established a biodynamic farm under the tutelage of the leading biodynamics exponent of the time, Dr. Ehrenfried Pfeiffer. When their property was under threat from a government program of DDT spraying, they brought their case, eventually lost it, in the process spent US$100,000, and compiled the evidence that they then shared with Carson, who used it, and their extensive contacts and the trial transcripts, as the primary input for Silent Spring. Carson attributed to Spock, Richards, and Pfeiffer, no credit whatsoever in her book. As a consequence, the organics movement has not received the recognition, that is its due, as the primary impulse for Silent Spring, and it is, itself, unaware of this provenance
Array phasing device Patent
Apparatus for generating microwave signals at progressively related phase angles for driving antenna arra
Industry Structure and Earnings Growth During National Business Cycles in Appalachia
Appalachia is a region that has undergone notable socio-economic change over the last twenty years. This change has produced communities of socio-economic “winners” and “losers.” In this paper, I attempt to understand why some communities \u27won\u27and others \u27lost\u27during this period using an analysis informed by two key sociological theories at the opposite end of the structure-agency continuum (new urban sociology, human ecology). The analysis combines shift-share analysis and the Land-Deane two-stage least squares technique for spatial effects to predict earnings change related to local industry mix and county effects for the following business cycles: 1980-82 recession, 1983-88 recovery, 1989-92 recession. The analysis shows that measures from both theoretical perspectives are important, but neither dominates (unlike in previous analyses). Implications for current/future theory and research are discussed
Federal Spending and Economic Growth in Appalachian Counties
In this paper I use a model informed by key theories of regional processes, and I test three related hypotheses concerning the effects of different types of federal spending (public investment, defense, salaries/wages) on economic growth in the 399 Appalachian counties during recent business cycles. The analysis incorporates a maximum likelihood estimate spatial lag regression model and shows the federal public investment spending and defense spending exerted net positive effects on per capita income, civilian employment, and private nonfarm employment growth rates between 1983 and 1988. In addition, public investment spending had a positive relationship with percentage of earnings from mining for the 1983-1988 period. Federal spending, however, had less consistent effects during the 1989-1992 recession. Implications for theory and research on regional processes are discussed
Murder, Nonnegligent Manslaughter, and Spatial Autocorrelation in Mid-South Counties
In this paper we explore to what extent murder and violent crime rates in the mid-South are spatially autocorrelated with a variety of county-level spatial association measures. The analysis shows that while statistically the murder and violent crime rates in the mid-Southern counties are spatialy associated, the degree of clustering among these counties is minimal-especially when compared to clustering among the significant predictors of violent crime (percent black, female headed households, percent in poverty, etc.). The analysis has important implications as to how county violent crime rates are being modeled
Right-to-Work Laws and Local Economic Growth: Recent Evidence from Appalachia
Right-to-work legislation continues to be debated at both the national and state levels. This paper seeks to inform the debate on the effectiveness of RTW laws as an economic development strategy. Using the 399 counties ofAppalachia as a case study, and a model informed by the human ecology and the new urban sociology, this paper compares recent earnings change during the last three business cycles in counties from right-to-work and non right-to-work states in the region. The analysis combines shift-share analysis and spatial lag regression analysis and estimates the relative effects of a variety of measures on county earnings change. The analysis fails to detect any overall advantage in earnings growth from nationally expanding industries for counties in RTW states since 1980. Moreover, the analysis indicates that other factors are more important in stimulating earnings growth from nationally expanding industries, particularly education. Implications for policy and legislative action are discussed
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