Coherent communication link using diode-pumped lasers

Work toward developing a diffraction limited, single frequency, modulated transmitter suitable for coherent optical communication or direct detection communication is discussed. Diode pumped, monolithic Nd:YAG nonplanar ring oscillators were used as the carrier beam. An external modulation technique which can handle high optical powers, has moderate modulation voltage, and which can reach modulation rates of 1 GHz was invented. Semiconductor laser pumped solid-state lasers which have high output power (0.5 Watt) and which oscillate at a single frequency, in a diffraction limited beam, at the wavelength of 1.06 microns were built. A technique for phase modulating the laser output by 180 degrees with a 40-volt peak to peak driving voltage is demonstrated. This technique can be adapted for amplitude modulation of 100 percent with the same voltage. This technique makes use of a resonant bulk modulator, so it does not have the power handling limitations of guided wave modulators

An ARIMA Methodology for Examining the Competitive Hypothesis in Agriculture

The adoption of advertising and product differentiation strategies normally associated with monopolistically competitive industry structures calls into question the competitive assumption generally utilized in agricultural econometrics. The scale of large corporate, and sole proprietor, farms has also expanded during the past century and a half. As a means for examining the competitive hypothesis, a univariate time series methodology is proposed that involves both formal statistical testing and informal inference regarding individual model characteristics. Empirical analysis utilizes data for seven vegetable producing regions of the United States

Implications of the Biofuels Boom for the Global Livestock Industry: A Computable General Equilibrium Analysis

In this paper, we offer a general equilibrium analysis of the impacts of US and EU biofuel mandates for the global livestock sector. Our simulation boosts biofuel production in the US and EU from 2006 levels to mandated 2015 levels. We show that mandates will encourage crop production in both biofuel and non biofuel producing regions, while reducing livestock and livestock production in most regions of the world. The non-ruminant industry curtails its production more than other livestock industries. The numerical results suggest that the biofuel mandates reduce food production in most regions while they increase crude vegetable oils in almost all regions. Implementing biofuel mandates in the US and EU will increase croplands within the biofuel and non-biofuel producer regions. A large portion of this increase will be obtained from reduced grazing lands. The biofuel producing regions are expected to reduce their coarse grains exports and raise imports of oilseeds and vegetable oils. While all livestock industries use more biofuel byproducts in their animal feed rations, the dairy and other ruminant industry benefit most from the expansion of DDGS. We finally conclude that, while biofuel mandates have important consequences for the livestock industry, they do not harshly curtail these industries. This is largely due to the important role of byproducts in substituting for higher priced feedstuffs. In addition, with relatively inelastic food demands, producers are able to pass much of the price rise on to consumers. In general, US, EU, Meddle East & North Africa, and Russia will experience significant welfare loses due to the combined US and EU mandates, while Brazil, Japan, India, and East Asia are expected to get major gains.Biofuels, Livestock, Feed Ration, Biofuel Co-Product, Land Use, Livestock Production/Industries,