On the ground electronic states of copper silicide and its ions

The low-lying electronic states of SiCu, SiCu^+, and SiCu^− have been studied using a variety of high-level ab initio techniques. As expected on the basis of simple orbital occupancy and bond forming for Si(s^2p^2)+Cu(s^1) species, ^2Π_r, ^1Σ^+, and ^3Σ^− states were found to be the ground electronic states for SiCu, SiCu^+, and SiCu^−, respectively; the ^2Π_r state is not that suggested in most recent experimental studies. All of these molecules were found to be quite strongly bound although the bond lengths, bond energies, and harmonic frequencies vary slightly among them, as a result of the nonbonding character of the 2π-MO (molecular orbital) [composed almost entirely of the Si 3p-AO (atomic orbital)], the occupation of which varies from 0 to 2 within the ^1Σ^+, ^2Π_r, and ^3Σ^− series. The neutral SiCu is found to have bound excited electronic states of ^4Σ^−, ^2Δ, ^2Σ^+, and ^2Π_i symmetry lying 0.5, 1.2, 1.8, and 3.2 eV above the ^2Π_r ground state. It is possible but not yet certain that the ^2Π_i state is, in fact, the “B state” observed in the recent experimental studies by Scherer, Paul, Collier, and Saykally

Weaber Plain aquifer test results

As a part of the environmental planning and approvals process, the state government was required to prepare Groundwater Management and Hydrodynamic Plans. These plans are to address potential issues of salinity and water quality that could result from the development of irrigated agriculture on the Weaber Plain. The Weaber Plain groundwater modelling report (KBR 2010a) identified several options to manage watertables and salinity Production bores 10WP35PB and 10WP36PB were drilled in the palaeochannel on sites selected from the interpretation of airborne geophysics

Weaber Plain hydrogeology: preliminary results

In 2008, the Ord Irrigation Expansion Project was approved by the Western Australian Government to develop irrigated agriculture on the Weaber Plain. Construction of the M2 supply channel connecting the ORIA and Weaber Plain, and the final period of irrigation design, environmental management and related approval processes commenced later in 2009. This process followed a protracted period of public and private industry planning and environmental assessment (Kinhill 2000). As a part of the environmental planning and approvals process, the WA Government was required to prepare a groundwater management plan and a hydrodynamic plan. These plans were to address potential issues of salinity and water quality that may result from developing the proposed farmlands

Cockatoo Sands in the Victoria Highway and Carlton Hill areas, East Kimberley: hydrogeology, aquifer properties and groundwater chemistry

Cockatoo Sands are recognised as potentially suitable for irrigated agriculture because they are generally well drained and not subject to waterlogging or inundation. These characteristics allow them to be cultivated and prepared for planting various crops during the wet and dry seasons of northern Australia. Expanding agricultural production onto the Cockatoo Sands around Kununurra will increase opportunities for agriculture by increasing the overall scale of agriculture, allowing year-round agricultural enterprise, new crops and new market opportunities. DAFWA has assessed the soil characteristics and agriculturally suitable areas of Cockatoo Sands in the Victoria Highway and Carlton Hill areas near Kununurra. Potential development areas (PDAs) comprising 6538 hectares (ha) at Victoria Highway and 2571ha at Carlton Hill were identified. DAFWA has also assessed the baseline surface water characteristics of run-off from catchments that contain the PDAs. This report describes the methodology, data and analyses used to derive the baseline hydrogeological conditions and physicochemical groundwater conditions that underlie the Victoria Highway and Carlton Hill PDAs

Highly charged ion X-rays from Electron-Cyclotron Resonance Ion Sources

Radiation from the highly-charged ions contained in the plasma of Electron-Cyclotron Resonance Ion Sources constitutes a very bright source of X-rays. Because the ions have a relatively low kinetic energy ($\approx 1$ eV) transitions can be very narrow, containing only small Doppler broadening. We describe preliminary accurate measurements of two and three-electron ions with Z=16--18. We show how these measurement can test sensitively many-body relativistic calculations or can be used as X-ray standards for precise measurements of X-ray transitions in exotic atoms

A study of the effect of water management and electrode flooding on the dimensional change of polymer electrolyte fuel cells

AbstractWater management and flooding play an important role in the performance and durability of polymer electrolyte fuel cells (PEFCs). In this study, a dynamic electro-mechanical analysis is performed to examine the performance of a working PEFC during hydration transients and flooding events. Cell resistance is measured using electrochemical impedance spectroscopy (EIS), and the stress/strain characteristics – cell compression and membrane electrode assembly (MEA) dimensional change – are studied using a controlled compression unit (CCU).Ex-situ measurements of membrane thickness as a function of hydration level provide a direct correlation between ionic conductivity and thickness. During initial hydration of Nafion membranes there is a direct relationship between membrane conductivity and dimensional change (swelling) of MEAs. Electrode flooding is found to result in membrane hydration and an increase in stress or strain, depending on the compression mode of the fuel cell. Results suggest that hydration cycles and flooding events can lead to cell degradation due to the stresses imposed

High stakes and low bars: How international recognition shapes the conduct of civil wars

When rebel groups engage incumbent governments in war for control of the state, questions of international recognition arise. International recognition determines which combatants can draw on state assets, receive overt military aid, and borrow as sovereigns—all of which can have profound consequences for the military balance during civil war. How do third-party states and international organizations determine whom to treat as a state's official government during civil war? Data from the sixty-one center-seeking wars initiated from 1945 to 2014 indicate that military victory is not a prerequisite for recognition. Instead, states generally rely on a simple test: control of the capital city. Seizing the capital does not foreshadow military victory. Civil wars often continue for many years after rebels take control and receive recognition. While geopolitical and economic motives outweigh the capital control test in a small number of important cases, combatants appear to anticipate that holding the capital will be sufficient for recognition. This expectation generates perverse incentives. In effect, the international community rewards combatants for capturing or holding, by any means necessary, an area with high concentrations of critical infrastructure and civilians. In the majority of cases where rebels contest the capital, more than half of its infrastructure is damaged or the majority of civilians are displaced (or both), likely fueling long-term state weakness

The Primacy of Public Health Considerations in Defining Poor Quality Medicines

Paul Newton and colleagues argue that public health, and not intellectual property or trade issues, should be the prime consideration in defining and combating counterfeit medicines, and that the World Health Organization (WHO) should take a more prominent role

Rapid Imaging of Earthquake Ruptures with Combined Geodetic and Seismic Analysis

Rapid determination of the location and extent of earthquake ruptures is helpful for disaster response, as it allows prediction of the likely area of major damage from the earthquake and can help with rescue and recovery planning. With the increasing availability of near real-time data from the Global Positioning System (GPS) and other global navigation satellite system receivers in active tectonic regions, and with the shorter repeat times of many recent and newly launched satellites, geodetic data can be obtained quickly after earthquakes or other disasters. We have been building a data system that can ingest, catalog, and process geodetic data and combine it with seismic analysis to estimate the fault rupture locations and slip distributions for large earthquakes