RoboNet‐II: Follow‐up observations of microlensing events with a robotic network of telescopes

RoboNet‐II uses a global network of robotic telescopes to perform follow‐up observations of microlensing events in the Galactic Bulge. The current network consists of three 2 m telescopes located in Hawaii and Australia (owned by Las Cumbres Observatory) and the Canary Islands (owned by Liverpool John Moores University). In future years the network will be expanded by deploying clusters of 1 m telescopes in other suitable locations. A principal scientific aim of the RoboNet‐II project is the detection of cool extra‐solar planets by the method of gravitational microlensing. These detections will provide crucial constraints to models of planetary formation and orbital migration. RoboNet‐II acts in coordination with the PLANET microlensing follow‐up network and uses an optimization algorithm (“web‐PLOP”) to select the targets and a distributed scheduling paradigm (eSTAR) to execute the observations. Continuous automated assessment of the observations and anomaly detection is provided by the ARTEMiS system (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

An RTML transport implementation on the Liverpool Telescope

The Liverpool Telescope is a 2.0m fully robotic telescope based on the Canary island of LaPalma. In this paper I describe the Java(TM) implementation of a method to transport RTML (Remote Telescope Markup Language) between a Node Agent (Web Services endpoint) embedded at the telescope and a remote Agent. The advantages and disadvantages of the method are discussed, along with the suitability of the protocol for HTN standardisation. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Geophysical identification of unmarked historic graves

Down‐hole magnetic susceptibility techniques were explored as a means of improving near‐surface geophysical surveys in historic grave detection. These techniques were used to document distinctive magnetic characteristics of grave shafts at three historic cemeteries first surveyed using various near‐surface geophysical methods. Tests revealed a low magnetic susceptibility signature that soil magnetic studies indicated was largely related to differential soil compaction associated with the excavation and refilling of grave shafts. Most apparent at depths beyond those reached by soil penetrometers, this magnetic signature offers a way to assess anomalies identified by near‐surface techniques that potentially represent graves. At one cemetery, magnetic studies of the interments themselves suggested spatially patterned, magnetically enhanced zones that might also aid in burial identification in certain contexts. While down‐hole techniques will not be foolproof, they do provide another geophysical tool that can be used to improve grave detection. © 2010 Wiley Periodicals, Inc.     

Modified predictor–corrector numerical scheme for real‐time pseudo dynamic tests using state‐space formulation

This paper deals with an explicit numerical integration method for real‐time pseudo dynamic tests. The proposed method, termed the MPC‐SSP method, is suited to use in real‐time pseudo dynamic tests as no iteration steps are involved in each step of computation. A procedure for implementing the proposed method in real‐time pseudo dynamic tests is described in the paper. A state‐space approach is employed in this study to formulate the equations of motion of the system, which is advantageous in real‐time pseudo dynamic testing of structures with active control devices since most structural control problems are formulated in state space. A stability and accuracy analysis of the proposed method was performed based on linear elastic systems. Owing to an extrapolation scheme employed to predict the system's future response, the MPC‐SSP method is conditionally stable. To demonstrate the effectiveness of the MPC‐SSP method, a series of numerical simulations were performed and the performance of the MPC‐SSP method was compared with other pseudo dynamic testing methods including Explicit Newmark, Central Difference, Operator Splitting, and OS‐SSP methods based on both linear and non‐linear single‐degree‐of‐freedom systems. Copyright © 2004 John Wiley & Sons, Ltd.     

A theoretical study of chemical kinetic control in the scavenging of pollutant gases by cloud and rain drops

Theoretical models that describe the uptake of trace gases by water drops falling at terminal velocity in air have been extended to include the effects of aqueous phase chemical processes that occur on time scales comparable with or greater than that over which the relevant physical scavenging processes operate. In particular, the case of reversible dervative formation by the absorbed species has been treated, and illustrated by application to the absorption of acetaldehyde under conditions prevailing in the atmosphere. In addition, the relative influences of aqueous phase chemistry and of convective-diffusion on the efficiency of the scavenging process have been explored more generally, using the revised models. A brief comparison of the factors controlling the uptake of sulfur dioxide, dichloromethane, and acetaldehyde is presented.     

On the scavenging of organic gases by cloud and raindrops: I. A theoretical and experimental study of acetaldehyde absorption and desorption for water drops in air

Our previously developed theoretical models for describing the rate at which water-soluble atmospheric trace gases are scavenged by cloud and rindrops were evaluated for the case of acetaldehyde being absorbed and desorbed by water drops of radii between 250 to 2500 m radius. The experimental verification of our theoretical predictions was carried out in the UCLA 33 m high precipitation shaft in which falling water drops were allowed to come to terminal velocity before passing through a chamber of variable lengths filled with air containing acetaldehyde at various partial pressures. For all drop sizes studied, the experimental results and the theoretical predictions were in reasonable agreement.     

A protocol standard for heterogeneous telescope networks

The scientific need for a standard protocol permitting the exchange of generic observing services is rapidly escalating as more observatories adopt service observing as a standard operating mode and as more remote or robotic telescopes are brought on‐line. To respond to this need, we present the results of the first interoperability workshop for Heterogeneous Telescope Networks (HTN) held in Exeter. We present a draft protocol, designed to be independent of the specific instrumentation and software that controls the remote and/or robotic telescopes, allowing these telescopes to appear to the user with a unified interface despite any underlying architectural differences. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Spatial and temporal changes in estuarine water quality during a post-flood hypoxic event

A major fish kill occurred in the Richmond River estuary in January 2008 due to oxygen depletion following extensive overbank flooding. This paper examines spatial and temporal changes in the chemistry of main channel waters, thereby identifying the primary sources of deoxygenating water. Over 40 km of the mid- to lower estuary main channel was deoxygenated within seven days of the flood peak. Hypoxia was confined to downstream of the confluences with mid-estuary backswamp basins and occurred during the later phase of the flood recession. Water chemistry at key locations in the estuary indicated elevated concentrations of redox sensitive species associated with acid sulfate soils (ASS) during the hypoxic period. Peak concentrations of Fe²⁺ up to 18.2 μmol L⁻¹, dissolved Mn up to 4.3 μmol L⁻¹, chemical oxygen demand (COD) up to 2052 μmol L⁻¹, dissolved organic carbon (DOC) up to 960 μmol L⁻¹ and elemental S⁰ up to 4.7 μmol L⁻¹ were found in the backswamp discharge confluences and mid-estuary main channel locations. The geochemical signature of main channel floodwaters identifies anaerobic decomposition of floodplain vegetation in ASS backswamps as a primary process leading to generation of hypoxic waters. The transport of these hypoxic floodwaters to the estuary has been accelerated and prolonged by extensive floodplain drainage, thereby enhancing the magnitude and duration of estuarine deoxygenation.     

Saltwater sport fishing for food or income in the Northeastern US: Statistical estimates and policy implications

In the Northeast US fishery managers have attempted to control marine recreational fishing mortality through annual adjustments to the number and/or size of fish that can be kept. These measures, with a few exceptions, have generally failed to prevent recreational fishing mortality rates from exceeding annual target levels. In this study, we show that one of the reasons why keep limits may have failed is that a substantial number of anglers obtain little value from being able to keep self-caught fish. Our findings are based on a telephone survey administered to marine anglers in all of the coastal counties in the Northeast US in 2004/2005. To evaluate the importance of keeping self-caught fish, we provide estimates of the size of the marine angling population in the Northeast US that keeps fish for food or income and also for those that fish primarily for recreation and place little or no value on keeping fish. Demographic characteristics of the two groups of anglers are compared statistically and differences related to consumption of self-caught marine resources and to health warning advisories are discussed. We also estimate the size of the Northeast US angling population that relies on their self-caught marine resources as a cost-saving food source or as a supplement to household income. This information could improve the effectiveness of fisheries regulations and the ability of policy analysts to predict how anglers might be affected by proposed fishery management actions.