On preconditioning strategies for geotechnics

Iterative solvers are of increasing interest in geomechanics with the move towards 3D finite element modelling. Potentially, these methods can lead to reduced computational complexity as, unlike direct methods, they do not require the full system matrix to be assembled. In general, however, iterative solvers have not been widely adopted in geomechanics due to problems with convergence. This paper reviews the background to iterative methods for elastic and elasto-plastic material models. In some cases, existing numerical methods can be taken from research in the mathematics community. For other systems, further work is needed. The paper provides demonstrations of the capabilities of some strategies

Red Altar

Poe

WATER RIGHTS AND THEIR SIGNIFICANCE TO AGRICULTURE

Resource /Energy Economics and Policy,

The Value of Monitoring Risk Averse Agents in Teams.

Vander Veen (1995) has argued that a principal has an incentive to monitor risk averse agents engaging in team production. We show that this result rests on specific informational assumptions that are not essential to team production. Moreover, under typical team environments and contract conditions there is no benefit from monitoring of individual agents, leaving only costs for the principal. We identify an additional mechanism design problem that arises in certain team settings-the principal must determine when to make information about each agent's reported ability public to the other team members.RISK ; MICROECONOMICS

Investigation of in vivo measurement of cerebral cytochrome-c-oxidase redox changes using near-infrared spectroscopy in patients with orthostatic hypotension

We have previously used a continuous four wavelength near infrared spectrometer to measure changes in the cerebral concentrations of oxy- (Δ[HbO2] and deoxy- haemoglobin (Δ[HHb]) during head-up tilt in patients with primary autonomic failure. The measured changes in light attenuation also allow calculation of changes in the concentration of oxidised cytochrome c oxidase (Δ[oxCCO]), and this paper analyses the Δ[oxCCO] during the severe episodes of orthostatic hypotension produced by this experimental protocol. We studied 12 patients during a passive change in position from supine to a 60º head-up tilt. The challenge caused a reduction in mean blood pressure of 59.93 (±26.12) mmHg (Mean (±SD), p<0.0001), which was associated with a reduction in the total concentration of haemoglobin (Δ[HbT]= Δ[HbO2]+Δ[HHb]) of 5.02 (±3.81) μM (p<0.0001) and a reduction in the haemoglobin difference concentration (Δ[Hbdiff]= Δ[HbO2]-Δ[HHb]) of 14.4 (±6.73) μM (p<0.0001). We observed a wide range of responses in Δ[oxCCO]. 6 patients demonstrated a drop in Δ[oxCCO] (0.17 ±0.15μM ); 4 patients demonstrated no change (0.01 ±0.12 μM ) and 2 patients showed an increase in Δ[oxCCO] (0.21 ±0.01 μM ). Investigation of the association between the changes in concentrations of haemoglobin species and the Δ[oxCCO] for each patient show a range of relationships. This suggests that a simple mechanism for crosstalk, which might produce artefactual changes in [oxCCO], is not present between the haemoglobin and the oxCCO NIRS signals. Further investigation is required to determine the clinical significance of the changes in [oxCCO]

Current practice in project appraisal in Europe.

The work reported in this paper presents the results from the compilation of the national assessment practices in EU25 Member States and Switzerland. The work was completed as part of the current European Union 6th Framework project HEATCO (Developing Harmonised European Approaches for Transport Costing and Project Assessment), which has the objective of developing a set of harmonised guidelines for project assessment and transport costing at an EU level. This paper presents the starting point to this project. Based on the work described in this paper the HEATCO consortium will be developing common definitions and consistent valuation methods for the evaluation of TEN projects. Previous projects such as EUNET had conducted a similar review to the research presented in this paper. The key reason for repeating the research was the expansion of the EU to 25 countries in May 2004 and the fact that appraisal practices in many countries has evolved since the last survey. A proforma was designed and sent to country representatives to complete. This paper is based predominantly on the results that this data provided. The proforma focused specifically on the use of Cost Benefit Analysis in appraisal with the aim of identifying similarities and differences in country practice. Aside from the national appraisal framework the proforma also considered the individual impacts included in appraisal. The paper describes some of the similarities and differences in how construction costs, time savings, safety and environmental impacts are used across Europe. The paper then concludes with the key differences and similarities as identified by the analysis. This paper aims at providing an overview of the current appraisal practice and more country specific details are given in Odgaard et al (2005)

Breeding vectors and predictability in the Oxford Mars GCM

A breeding vectors approach is used to study the intrinsic predictability of the Martian atmosphere using the Oxford Mars General Circulation Model (MGCM). The approach, described in detail below, is first tested using a terrestrial general circulation model, the United Kingdom Meteorological Office's Unified Model (UM), and results show growing modes of instability at mid to high latitudes on spatial scales of less than ~1,000km, in qualitative agreement with previous studies performed using terrestrial models. For the Martian atmosphere, and in the absence of radiatively active dust transport (so using a typical background dust distribution for each time of year), the technique reveals model states with approximately zero growth factors, and modes of instability on relatively large (up to ~5,000km) spatial scales. The implications of this for the predictability of the Martian atmosphere and for the usage of ensemble forecasting methods on Mars are also discussed

Local Maximum Entropy Shape Functions Based FE-EFGM Coupling

In this paper, a new method for coupling the finite element method (FEM)and the element-free Galerkin method (EFGM) is proposed for linear elastic and geometrically nonlinear problems using local maximum entropy shape functions in theEFG zone of the problem domain. These shape functions possess a weak Kroneckerdelta property at the boundaries which provides a natural way to couple the EFGand the FE regions as compared to the use of moving least square basis functions.In this new approach, there is no need for interface/transition elements between theEFG and the FE regions or any other special treatment for shape function continuity across the FE-EFG interface. One- and two-dimensional linear elastic and two-dimensional geometrically nonlinear benchmark numerical examples are solved by the new approach to demonstrate the implementation and performance of the current approach

The Failure of Local and Federal Prosecutors to Curb Police Brutality

Although police departments across the country have attempted to ameliorate the hostility between police officers and the cumminity, through careful screening of applicants, minority recruitment, and community policing, police brutality remains a problem within our urban cities. This Essay will first argue that police brutality is largely ignored. Second, it will examine the obstacles facing local and federal prosecutors in obtaining convictions. Then it will compare the advantages and disadvantages of delegating primary responsibility for these cases to the state versus the federal level. Finally, it will argue that, although there are obstacles and advantages for both local and federal prosecutors, ultimately justice is best seved when police brutality is primarily pursued by local prosecutors

Mineral reconnaissance at the Highland boundary with special reference to the Loch Lomond and Aberfoyle areas

Serpentinite bodies at the Highland Boundary in the Loch Lomond and Aberfoyle areas are extensively altered to magnesite-quartz and ferroan-dolomite-quartz rocks. Silicification was probably initiated before conversion to carbonate. Relict textures indicate that the serpentinites were derived from peridotitic precursors, but one unaltered ultrabasic sample comprises mainly chromian diopside. Chromite geochemistry and hornblende-schist mineralogy rein force the ophiolitic character of the serpentinite-spilite-blackshale- chcrt assemblage of the Highland Border. Magnetic and VLF traverses across the Highland Boundary fracture-zone near Helensburgh identified several anomalous zones. One may be due to a concealed serpentinitic sheet. The most mineralised serpentinite body showed chromium values in the range 1000 to 3035 ppm. Such concentrations arc not encouraging for the small serpentinites at Loch Lomond and Aberfoyle, but may be significant regarding larger serpentinites elsewhere at the Highland Border