Moon-tracking orbits using motorized tethers for continuous earth–moon payload exchanges

For human colonization of the moon to become reality, an efficient and regular means of exchanging resources between the Earth and the moon must be established. One possibility is to pass and receive payloads at regular intervals between a symmetrically laden motorized momentum-exchange tether orbiting about Earth and a second orbiting about the moon. There are significant challenges associated with this method, among the greatest of which is the development of a system that incorporates the complex motion of the moon into its operational architecture in addition to conducting these exchanges on a per-lunar-orbit basis. One way of achieving this is to use a motorized tether orbiting Earth and tracking the nodes of the moon’s orbit to allow payload exchanges to be undertaken periodically with the arrival of the moon at either of these nodes. Tracking these nodes is achieved by arranging the tether to orbit Earth with a critical inclination, thus rendering its argument of perigee stationary in addition to using the precession effects resulting from an oblate Earth. Using this in conjunction with pre-emptive adjustments to its angle of right ascension, the tether will periodically realign itself with these nodes simultaneously with the arrival of the moon

Hybrid fuzzy and sliding-mode control for motorised tether spin-up when coupled with axial vibration

A hybrid fuzzy sliding mode controller is applied to the control of motorised tether spin-up coupled with an axial oscillation phenomenon. A six degree of freedom dynamic model of a motorised momentum exchange tether is used as a basis for interplanetary payload exchange. The tether comprises a symmetrical double payload configuration, with an outrigger counter inertia and massive central facility. It is shown that including axial elasticity permits an enhanced level of performance prediction accuracy and a useful departure from the usual rigid body representations, particularly for accurate payload positioning at strategic points. A special simulation program has been devised in MATLAB and MATHEMATICA for a given initial condition data case

The Cow That Stole Christmas: Framing the First U.S. Mad Cow Crisis

The discovery of bovine spongiform encephalopathy (BSE) in the United States made an impact on the beef industry. Determining how the BSE outbreak was framed by the news media is significant because research indicates that media shape public perceptions. This study examined how several key newspapers framed the 2003 outbreak of BSE in the United States. Determining how the media framed this issue can help communicators ensure bias-free media coverage of similar issues in the future. The study followed established framing analysis categories identified from the literature. There were 149 articles identified in The Washington Post, The Seattle Times, and USA Today for investigation in this study. Findings showed that the BSE issue was framed as an industry crisis and that the tone of the articles and headlines portrayed the beef industry negatively. When compared to the other two newspapers, USA Today framed the issue differently, with economic calamity being the dominant frame. The most heavily cited sources in the articles were government officials. This study recommends that media professionals avoid framing an issue for the public, focusing instead on reporting news in an objective and unbiased manner. Further research is recommended to examine the impact of tone and frame on specific audiences

Beef Producers\u27 Risk Perceptions of an Agroterrorism Event Occurring in Oklahoma

The purpose of this statewide study was to determine Oklahoma beef producers’ perceptions of the susceptibility of the state’s beef industry to a terrorist attack. Participants in this study were randomly selected from a population of 48,000 beef producers in this Oklahoma. All 470 respondents completed a telephone survey conducted by the Oklahoma Agricultural Statistics Service. Descriptive statistics, t-tests, and cross tabulations were used to analyze the data. Oklahoma beef producers perceived the beef industry was susceptible to an agroterrorism event, believed the feedlots to be at an elevated level of threat, were confident in their own operation’s biosecurity measures, believed their own operation was not susceptible to an agroterrorism event, and did not believe they had enough information about protection from terrorism to the beef industry

Agroterrorism and the Implications of Uncertainty Reduction Theory for Agricultural Communicators

As a consequence of various terrorist attacks on U.S. soil the vulnerability of American agriculture to an agro-terrorist attack has come into question. The objective of this paper is to view the threat of agroterrorism through the lens of uncertainty reduction theory and extend the original application of the theory from the realm of interpersonal communication to the mass communication level. We offer a brief overview of bioterrorism and agriculture and the general concepts of crisis communication and pre-crisis preparedness. We explain the relationship between the level of uncertainty and organizational crisis with the value of pre-crisis planning efforts. We show the importance of the agricultural communicator as a source of agricultural knowledge in the pre-crisis stage, which can contribute to reducing uncertainty following an agro-terrorist event

Before it Hits the Fan: Pre-Crisis Beef Producer Information Source Preferences

The purpose of this statewide study was to determine preferences for the sources of information beef producers in Oklahoma use and trust when they seek information about agriculture during a crisis. Participants in this study were randomly selected from a population of 48,000 beef producers in the Oklahoma. All 470 respondents completed a telephone survey conducted by the Oklahoma Agricultural Statistics Service (OASS). Descriptive statistics, t-tests, and cross tabulations were used to analyze the data. Producers preferred their veterinarians when seeking information about animal health issues and any agriculturally related crisis; and preferred to receive information through county extension publications. They also perceived the local veterinarian as the most trusted and reliable source of information available. The Oklahoma State University Cooperative Extension Service, through the county extension agents and the local area livestock specialists, and the USDA were also trustworthy and reliable sources

On the modelling and testing of a laboratory scale Foucault pendulum as a precursor for the design of a high performance measurement instrument

An integrated study is presented on the dynamic modelling and experimental testing of a mid-length Foucault pendulum with the aim of confirming insights from the literature on the reliable operation of this device and setting markers for future research in which the pendulum may be used for the measurement of relativistic effects due to terrestrial gravity. A tractable nonlinear mathematical model is derived for the dynamics of a practical laboratory Foucault pendulum and its performance with and without parametric excitation, and with coupling to long-axis torsion is investigated numerically for different geographical locations. An experimental pendulum is also tested, with and without parametric excitation, and it is shown that the model closely predicts the general precessional performance of the pendulum, for the case of applied parametric excitation of the length, when responding to the Newtonian rotation of the Earth. Many of the principal inherent performance limitations of Foucault pendulums from the literature have been confirmed and a general prescription for design is evolved, placing the beneficial effect of principal parametric resonance of this inherently nonlinear system in a central mitigating position, along with other assistive means of response moderation such as excitational phase control through electromagnetic pushing, enclosure, and the minimization of seismic and EMC noise. It is also shown, through a supporting analysis and calculation, that although the terrestrial measurement of the Lense-Thirring (LT) precession by means of a Foucault pendulum is certainly still within the realms of possibility, there remains a very challenging increase in resolution capability required, in the order of 2 × 10 9 to be sure of reliable detection, notwithstanding the removal of extraneous motions and interferences. This study sets the scene for a further investigation in the very near future in which these challenges are to be met, so that a new assault can be made on the terrestrial measurement of LT precession

Fate and occurrence of alkylphenolic compounds in sewage sludges determined by liquid chromatography tandem mass spectrometry

This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ 2009 Taylor & Francis.An analytical method has been developed and applied to determine the concentrations of the nonionic alkylphenol polyethoxylate surfactants and their metabolites, alkylphenoxy carboxylates and alkyphenols, in sewage sludges. The compounds were extracted with methanol/acetone (1:1 v/v) from sludge, and concentrated extracts were cleaned by silica solid‐phase extraction prior to determination by liquid chromatography tandem mass spectrometry. The recoveries, determined by spiking sewage sludge at two concentrations, ranged from 51% to 89% with method detection limits from 6 µg kg−1 to 60 µg kg−1. The methodology was subsequently applied to sludge samples obtained from a carbonaceous activated sludge plant, a nitrifying/denitrifying activated sludge plant and a nitrifying/denitrifying activated sludge plant with phosphorus removal. Concentrations of nonylphenolic compounds were two to three times higher than their octyl analogues. Long‐chain nonylphenol polyethoxylates (NP3–12EO) ranged from 16 µg kg−1 to 11754 µg kg−1. The estrogenic metabolite nonylphenol was present at concentrations ranging from 33 µg kg−1 to 6696 µg kg−1.Public Utilities Board of Singapore, Thames Water and Yorkshire Water

Influence of innate sludge factors and ambient environmental parameters in biosolids storage on indicator bacteria survival: A review

The potential health risks associated with sludge cake application to agricultural land are managed by controlling the levels of Escherichia coli (E. coli) bacteria which indicate the risk of pathogen transfer. Analyses undertaken following post-digestion sludge dewatering have shown unpredictable levels of E. coli increase in stored sludge cake. Presently there is limited understanding on environmental parameters controlling the indicator bacteria density in storage and the contributory effects dewatering may have. This review aims to establish the state of current knowledge on innate and environmental factors influencing E. coli dynamics and survival in biosolids. A key factor identified is the effect of mechanical dewatering processes, which transform the sludge matrix environmental conditions through the increased availability of growth factors (e.g. nutrient and oxygen). Examples of storage practices from the agricultural and food industries are also discussed as successful methods to inhibit bacterial growth and survival, which could be extrapolated to the biosolids sector to regulate E. coli concentrations