Adding user interactivity to FreeFem++ with EJS: From teaching to research

Conferencia plenaria por invitaciónIn this talk we propose the use of an authoring tool, Easy Java Simulations, to build interactive simulations for pdes where the computing kernel is FreeFem++. This tool allows to play with all the parameters of the pde problem at will, mesh size, pde terms, boundary conditions, etc... and creates applets for the student to play and learn in real time on the influence of these parameters on the solution of the pde.Universidad de Málaga. Campus de Excelencia Internacional Andalucia Tech. Conferencias del plan propio de investigación

Dynamic Behavior of Spiral-Groove and Rayleigh-Step Self-Acting Face Seals

Tests were performed to determine the dynamic behavior and establish baseline dynamic data for five self-acting face seals employing Rayleigh-step lift-pads and inward pumping as well as outward-pumping spiral grooves for the lift-generating mechanism. The primary parameters measured in the tests were film thickness, seal seat axial motion, and seal frictional torque. The data show the dynamic response of the film thickness to the motion of the seal seat. The inward-pumping spiral-groove seals exhibited a high-amplitude film thickness vibratory mode with a frequency of four times the shaft speed. This mode was not observed in the other seals tested. The tests also revealed that high film thickness vibration amplitude produces considerably higher average film thickness than do low amplitude film thickness vibrations. The seals were tested at a constant face load of 73 N (16.4 lb) with ambient air at room temperature and atmospheric pressure as the fluid medium. The test speed range was from 7000 to 17000 rpm. Seal tangential speed range was 34.5 to 83.7 m/sec (113 to 274 ft/sec)

Anti-money laundering and counter-terrorism financing survey of regulated businesses in Australia - methodology report

This report provides a stand-alone description of how the Australian Institute of Criminology’s Anti-money Laundering/Counter-terrorism Financing Survey of regulated businesses was undertaken, emphasising the importance of understanding the methodology and design of this national census of regulated businesses in Australia. As is often the case with social scientific research of a quantitative nature, the detail of how surveys were conducted are sometimes relegated to deep within a long report, or attached in a lengthy appendix, often being overlooked by the average reader. This report provides a stand-alone description of how the Australian Institute of Criminology’s Anti-money Laundering/Counter-terrorism Financing Survey of regulated businesses was undertaken, thus emphasising the importance of understanding the methodology and design of this national census of regulated businesses in Australia. It reviews all of the procedures and steps undertaken from a data collection and methodological perspective and provides an important accompaniment to the major survey report published in conjunction with this methodological review. Both reports should be read together. The current report provides a summary of the methodological approach, consolidation of assorted reports generated throughout the study, a review of sample utilisation and response dynamics and a summary of issues for consideration for future similar surveys

Performance tests of a cryogenic hybrid magnetic bearing for turbopumps

Experiments were performed on a Hybrid Magnetic Bearing designed for cryogenic applications such as turbopumps. This bearing is considerably smaller and lighter than conventional magnetic bearings and is more efficient because it uses a permanent magnet to provide a bias flux. The tests were performed in a test rig that used liquid nitrogen to simulate cryogenic turbopump temperatures. The bearing was tested at room temperature and at liquid nitrogen temperature (-320 F). The maximum speed for the test rig was 14000 rpm. For a magnetic bearing stiffness of 20000 lb/in, the flexible rotor had two critical speeds. A static (nonrotating) bearing stiffness of 85000 lb/in was achieved. Magnetic bearing stiffness, permanent magnet stiffness, actuator gain, and actuator force interaction between two axes were evaluated, and controller/power amplifier characteristics were determined. The tests revealed that it is feasible to use this bearing in the cryogenic environment and to control the rotor dynamics of flexible rotors when passing through bending critical speeds. The tests also revealed that more effort should be placed on enhancing the controller to achieve higher bearing stiffness and on developing displacement sensors that reduce drift caused by temperature and reduce sensor electrical noise

Experimental evaluation of a tuned electromagnetic damper for vibration control of cryogenic turbopump rotors

Experiments were performed on a passive tuned electromagnetic damper that could be used for damping rotor vibrations in cryogenic turbopumps for rocket engines. The tests were performed in a rig that used liquid nitrogen to produce cryogenic turbopump temperatures. This damper is most effective at cryogenic temperatures and is not a viable damper at room temperature. The unbalanced amplitude response of the rotor shaft was measured for undamped (baseline) and damped conditions at the critical speeds of the rotor (approx. 5900 to 6400 rpm) and the data were compared. The tests were performed for a speed range between 900 and 10 000 rpm. The tests revealed that the damper is very effective for damping single-mode narrow bandwidth amplitude response but is less effective in damping broadband response or multimode amplitude response

Elasticity of cigarette demand in Argentina: An empirical analysis using vector error-correction model.

Is objective this paper estimate empirically the short and long-term effects on cigarette demand in Argentina based on changes in cigarette price and income. We analyzed data from the Ministry of Economy and Production of Argentina. Analysis was based on monthly time-series data between 1994 and 2004. The econometrics specification is a linear double-logarithmic form using cigarettes consumption per person older than 14 y. as dependent variable and real income per person older than 14 y. and the real average price of cigarettes sales as independent variables. Empirical analyses were done in three steps: 1) To verify the order of integration of the variables using the augmented Dickey-Fuller test; 2) To test for co-integration using the Johansen-Juselius maximum likelihood approach to capture the long-term effects; and 3) To utilize the Vector error-correction model to capture the short-run dynamics of the variables.Results: The empirical results showed that in the long-term period the demand for cigarettes in Argentina is affected by changes in real income and real average price of cigarettes. The value of income elasticity is equal to 0.54 while the value of own-price elasticity is equal to –0.34. The results using vector error-correction model estimation suggest that the short-term cigarette demand in Argentina is independent of price (not statistically significant). The value of the short-term income elasticity is equal to 0.49. A simulation exercise show that increasing the prices in a 120% we can obtain a maximum of revenues from cigarette tax and obtain also a big impact in the fall of the total consumption of cigarettes in the country.Price elasticity, cigarette demand, Tobacco control