Assessment of casting filling by modeling surface entrainment events using CFD

The reliability of cast components is dependent on the quality of the casting process. During this highly transient filling phase the prevention of free surface turbulence and consequential oxide entrainment is critical to ensure the mechanical integrity of the component. Past research has highlighted a number of events that lead to entrainment of surface oxides. Using FLOW-3D, flow structures that result in surface entrainment events have been simulated and an algorithm developed that allows entrainment and defect motion to be tracked. This enables prediction of the quantity and motion of oxide film generated from each event. The algorithm was tested experimentally and compared to experimental data from previously published work. A quantitative criterion is proposed to assess the damage of each type of event. Complete running systems have also been studied to understand how they could be assessed for quality of filling based on the flows within them

Assessing impacts to groundwater from CO2-flooding of SACROC and Claytonville oil fields in West Texas

Comparison of groundwater above two Permian Basin oil fields (SACROC Unit and Claytonville Field) near Snyder, Texas should allow us to assess potential impacts of 30 years of CO2-injection. CO2-flooding for enhanced oil recovery (EOR) has been active at SACROC in Scurry County since 1972. Approximately 13.5 million tons per year (MtCO2/yr) are injected with withdrawal/recycling amounting to ~7MtCO2/yr. It is estimated that the site has accumulated more than 55MtCO2; however, no rigorous investigation of overlying groundwater has demonstrated that CO2 is trapped in the subsurface. Mineralogy of reservoir rocks at the Claytonville field in southwestern Fisher County is similar to SACROC. CO2-EOR is scheduled to begin at Claytonville Field in Fisher County in early 2007. Here we have the opportunity to characterize groundwater prior to CO2-injection and establish baseline conditions at Claytonville. Methods of this study will include: (1) examination of existing analyses of saline to fresh water samples collected within an eight-county area encompassing SACROC and Claytonville, (2) additional groundwater sampling for analysis of general chemistry plus field-measured pH, alkalinity, and temperature, stable isotopic ratios of hydrogen (D/H), oxygen (18O/16O), and carbon (13C/12C), and (3) geochemical equilibrium and flowpath modeling. Existing groundwater data are available from previous BEG studies, Texas Water Development Board, Kinder Morgan CO2 Company, and the U. S. Geological Survey. By examining these data we will identify regional groundwater variability and focus additional sampling efforts. The objective of this study is to look for potential impacts to shallow groundwater from deep CO2-injection. In the absence of conduit flow from depth, we don’t expect to see impacts to shallow groundwater, but methodology to demonstrate this to regulators needs to be established. This work is a subset of the Southwest Regional Partnership on Carbon Sequestration Phase 2studies funded by the Department of Energy (DOE) in cooperation with industry and government partners.Bureau of Economic Geolog

The modelling of oxide film entrainment in casting systems using computational modelling

As Campbell stated in 2006, “the use of entrainment models to optimise filling systems designs for castings has huge commercial potential that has so far being neglected by modellers”. In this paper a methodology using computational modelling to define entraining events and track the entrained oxide films is presented. Research has shown that these oxide films present within the casting volume are highly detrimental to casting integrity, thus their entrainment during mould filling is especially undesirable. The method developed for the modelling of oxide entrainment has been validated against previously published data by Green and Campbell (1994) [31]. The validation shows good quantitative correlation with experimental data. However there is scope for further development which has the potential to both improve the accuracy and further validate the technique

A subset of precise UML for Model-based Testing

This paper presents an original model-based testing approach that takes a UML behavioural view of the system under test and automatically generates test cases and executable test scripts according to model coverage criteria. This approach is embedded in the LEIRIOS Test Designer tool and is currently deployed in domains such as Enterprise IT and electronic transaction applications. This model-based testing approach makes it possible to automatically produce the traceability matrix from requirements to test cases as part of the test generation process. This paper defines the subset of UML used for model-based testing and illustrates it using a small example

The debris disk - terrestrial planet connection

The eccentric orbits of the known extrasolar giant planets provide evidence that most planet-forming environments undergo violent dynamical instabilities. Here, we numerically simulate the impact of giant planet instabilities on planetary systems as a whole. We find that populations of inner rocky and outer icy bodies are both shaped by the giant planet dynamics and are naturally correlated. Strong instabilities -- those with very eccentric surviving giant planets -- completely clear out their inner and outer regions. In contrast, systems with stable or low-mass giant planets form terrestrial planets in their inner regions and outer icy bodies produce dust that is observable as debris disks at mid-infrared wavelengths. Fifteen to twenty percent of old stars are observed to have bright debris disks (at wavelengths of ~70 microns) and we predict that these signpost dynamically calm environments that should contain terrestrial planets.Comment: Contribution to proceedings of IAU 276: Astrophysics of Planetary System

Toxicity of cancer therapy: what the cardiologist needs to know about angiogenesis inhibitors

Clinical outcomes for patients with a wide range of malignancies have improved substantially over the last two decades. Tyrosine kinase inhibitors (TKIs) are potent signalling cascade inhibitors and have been responsible for significant advances in cancer therapy. By inhibiting vascular endothelial growth factor receptor (VEGFR)-mediated tumour blood vessel growth, VEGFR-TKIs have become a mainstay of treatment for a number of solid malignancies. However, the incidence of VEGFR-TKI-associated cardiovascular toxicity is substantial and previously under-recognised. Almost all patients have an acute rise in blood pressure, and the majority develop hypertension. They are associated with the development of left ventricular systolic dysfunction (LVSD), heart failure and myocardial ischaemia and can have effects on myocardial repolarisation. Attention should be given to rigorous baseline assessment of patients prior to commencing VEGFR-TKIs, with careful consideration of baseline cardiovascular risk factors. Baseline blood pressure measurement, ECG and cardiac imaging should be performed routinely. Hypertension management currently follows national guidelines, but there may be a future role forendothelin-1 antagonism in the prevention or treatment of VEGFR-TKI-associated hypertension. VEGFR-TKI-associated LVSD appears to be independent of dose and is reversible. Patients who develop LVSD and heart failure should be managed with conventional heart failure therapies, but the role of prophylactic therapy is yet to be defined. Serial monitoring of left ventricular function and QT interval require better standardisation and coordinated care. Management of these complex patients requires collaborative, cardio-oncology care to allow the true therapeutic potential from cancer treatment while minimising competing cardiovascular effects

A middleware for a large array of cameras

Large arrays of cameras are increasingly being employed for producing high quality image sequences needed for motion analysis research. This leads to the logistical problem with coordination and control of a large number of cameras. In this paper, we used a lightweight multi-agent system for coordinating such camera arrays. The agent framework provides more than a remote sensor access API. It allows reconfigurable and transparent access to cameras, as well as software agents capable of intelligent processing. Furthermore, it eases maintenance by encouraging code reuse. Additionally, our agent system includes an automatic discovery mechanism at startup, and multiple language bindings. Performance tests showed the lightweight nature of the framework while validating its correctness and scalability. Two different camera agents were implemented to provide access to a large array of distributed cameras. Correct operation of these camera agents was confirmed via several image processing agents

The incidence of mid-infrared excesses in G and K giants

Using photometric data from the 2MASS and GLIMPSE catalogues, I investigate the incidence of mid-infrared excesses (~10 microns) of G and K stars of luminosity class III. In order to obtain a large sample size, stars are selected using a near-IR colour-magnitude diagram. Sources which are candidates for showing mid-IR excess are carefully examined and modelled to determined whether they are likely to be G/K giants. It is found that mid-IR excesses are present at a level of (1.8 +/- 0.4) x 10^-3. While the origin of these excesses remains uncertain, it is plausible that they arise from debris discs around these stars. I note that the measured incidence is consistent with a scenario in which dust lifetimes in debris discs are determined by Poynting-Robertson drag rather than by collisions.Comment: Accepted for publication in MNRAS. 13 pages, 5 figures, 2 tables (1 landscape table

A Systematic Review of the Selected Evidences on the Effectiveness of Inter-professional Education (IPE) in Developing Interprofessional Learning Environment

Purpose: This systematic review aimed to provide available evidence in determining for the effectiveness of IPE as a modality in developing interprofessional learning environment for healthcare students.Methods: The computerized searches from 2009-2015 in ten electronic databases were performed. Two independent reviewers were consulted to assess the eligibility, level of evidences and methodological quality in each study. Result: nine out of ten studies were retrieved. These studies include (a) two RCT studies; scored eight and seven out of eight, (b) Three quasi-experimental pretestposttest design; scored seven, six, and six out of eight, (c) Three controlled before and after study; scored six, six, five and five out of eight, and (d) one controlled longitudinal; scored six out of eight respectively.Conclusion: Based on the systematic review, evidence showed that IPE was effective in building strong interprofessional learning environment. On the other hand, the authors recommend considering conduct of similar systematic review grounded on IPE with larger sample size within the health allied discipline