9 research outputs found

    Physical properties of 368 meteorites: Implications for meteorite magnetism and planetary geophysics

    Get PDF
    Petrophysical studies (susceptibility, intensity of natural remanent magnetisation (NRM) and dry bulk density) of 368 meteorites are reviewed together with magnetic hysteresis data for 50 achondrites and chondrites. The relationships between dry bulk density, metallic FeNi-content and porosity will be discussed in the case of L-chondrites. Using the petrophysical classification scheme the meteorite class and the petrologic group of a sample can be determined in most of the cases providing a rapid means for determining a preliminary classification of a new sample. In addition, the petrophysical database provides a direct source of basic physical properties of the small bodies in the solar system. Paleointensity determinations with Thellier technique will be presented for 16 meteorites representing different chondrite groups. The results yield high paleofield values ranging from 51μT to 728μT for the magnetically hardest meteorites consistent with previous studies. However, these values must be looked with caution, because of possible physico-chemical or mineralogical alterations during heating

    Benchmarking of two flexible multibody dynamic simulation software in engine simulations

    No full text
    Summary In this paper, two different commercial multibody dynamic (MBD) simulation software cases are studied. Due to the restrictions determined in the conditions of contract, the names of the software are not revealed, instead being called Software S and Software E. The central purpose of this research was to investigate the abilities of Software S in the simulation of a large engine, as a part of the strength analysis process. The abilities were studied by comparing the program with another, here called Software E, which is designed primarily for engine simulations. The capabilities of Software E have been proven after years of usage at Wärtsilä, resulting in its essential role in the strength analysis process today. The aim was to find the shortcomings and restrictions of Software S but also advantages it could bring to the strength analysis process for Wärtsilä. Similar simulation models were also built using both programs during this research. A 16-cylinder V-engine was selected as the subject because of its size in order to obtain further information about the behavior of the program when working with extensive model files. The components of the engine were flexible and were reduced FE models, also called super elements. The forces and contact situations that occur inside the engine were modeled using elements provided by the MBD programs. Different levels of detail of the modeling elements were used to obtain information about the flexibility of the program. The results obtained from time integrations were compared to ensure the similarity of both modeling elements used. Also, this paper reports the calculation times. In addition, a small-scale study was performed for Software S to clarify the effect of the modes used in time integrations towards results accuracy and calculation times. Simulation models were built successfully in both programs, and the results obtained correlated with each other on an adequate level. Significant differences appeared in the features and usability of the programs in general. The GUI of Software S is advanced and user-friendly, whereas Software E is not focused on these features. On the other hand, the modeling element library of Software E covers all of the required features related to large engine simulations, some of which Software S is lacking. This work can be used in assistance when considering buying new software for a company as well as when investigating new development areas that could be improved with new software

    A magnetic susceptibility database for stony meteorites

    No full text
    Consiglio Nazionale delle Ricerche - Biblioteca Centrale - P.le Aldo Moro, 7 , Rome / CNR - Consiglio Nazionale delle RichercheSIGLEITItal

    the European trial on Reduction of Cardiac Events with Perindopril in Stable Coronary Artery Disease Investigators. Efficacy of perindopril in reduction of cardiovascular events among patients with stable coronary artery disease: randomised, double-blind, placebo-controlled, multicentre trial (the EUROPA trial).

    No full text
    Background Treatment with angiotensin-converting-enzyme (ACE) inhibitors reduces the rate of cardiovascular events among patients with left-ventricular dysfunction and those at high risk of such events. We assessed whether the ACE inhibitor perindopril reduced cardiovascular risk in a low-risk population with stable coronary heart disease and no apparent heart failure. Methods We recruited patients from October, 1997, to June, 2000. 13 655 patients were registered with previous myocardial infarction (64%), angiographic evidence of coronary artery disease (61%), coronary revascularisation (55%), or a positive stress test only (5%). After a run-in period of 4 weeks, in which all patients received perindopril, 12 218 patients were randomly assigned perindopril 8 mg once daily (n=6110), or matching placebo (n=6108). The mean follow-up was 4·2 years, and the primary endpoint was cardiovascular death, myocardial infarction, or cardiac arrest. Analysis was by intention to treat. Findings Mean age of patients was 60 years (SD 9), 85% were male, 92% were taking platelet inhibitors, 62% blockers, and 58% lipid-lowering therapy. 603 (10%) placebo and 488 (8%) perindopril patients experienced the primary endpoint, which yields a 20% relative risk reduction (95% CI 9–29, p=0·0003) with perindopril. These benefits were consistent in all predefined subgroups and secondary endpoints. Perindopril was well tolerated. Interpretation Among patients with stable coronary heart disease without apparent heart failure, perindopril can significantly improve outcome. About 50 patients need to be treated for a period of 4 years to prevent one major cardiovascular event. Treatment with perindopril, on top of other preventive medications, should be considered in all patients with coronary heart disease

    Efficacy of perindopril in reduction of cardiovascular events among patients with stable coronary artery disease: randomised, double-blind, placebo-controlled, multicentre trial (the EUROPA study)

    No full text
    BACKGROUND: Treatment with angiotensin-converting-enzyme (ACE) inhibitors reduces the rate of cardiovascular events among patients with left-ventricular dysfunction and those at high risk of such events. We assessed whether the ACE inhibitor perindopril reduced cardiovascular risk in a low-risk population with stable coronary heart disease and no apparent heart failure. METHODS: We recruited patients from October, 1997, to June, 2000. 13655 patients were registered with previous myocardial infarction (64%), angiographic evidence of coronary artery disease (61%), coronary revascularisation (55%), or a positive stress test only (5%). After a run-in period of 4 weeks, in which all patients received perindopril, 12218 patients were randomly assigned perindopril 8 mg once daily (n=6110), or matching placebo (n=6108). The mean follow-up was 4.2 years, and the primary endpoint was cardiovascular death, myocardial infarction, or cardiac arrest. Analysis was by intention to treat. FINDINGS: Mean age of patients was 60 years (SD 9), 85% were male, 92% were taking platelet inhibitors, 62% beta blockers, and 58% lipid-lowering therapy. 603 (10%) placebo and 488 (8%) perindopril patients experienced the primary endpoint, which yields a 20% relative risk reduction (95% CI 9-29, p=0.0003) with perindopril. These benefits were consistent in all predefined subgroups and secondary endpoints. Perindopril was well tolerated. INTERPRETATION: Among patients with stable coronary heart disease without apparent heart failure, perindopril can significantly improve outcome. About 50 patients need to be treated for a period of 4 years to prevent one major cardiovascular event. Treatment with perindopril, on top of other preventive medications, should be considered in all patients with coronary heart disease

    The European Trial On Reduction of Cardiac Events with Perindopril in Stable Coronary Artery Disease

    No full text
    Background Treatment with angiotensin-converting-enzyme (ACE) inhibitors reduces the rate of cardiovascular events among patients with left-ventricular dysfunction and those at high risk of such events. We assessed whether the ACE inhibitor perindopril reduced cardiovascular risk in a low-risk population with stable coronary heart disease and no apparent heart failure. Methods We recruited patients from October, 1997, to June, 2000. 13 655 patients were registered with previous myocardial infarction (64%), angiographic evidence of coronary artery disease (61%), coronary revascularisation (55%), or a positive stress test only (5%). After a run-in period of 4 weeks, in which all patients received perindopril, 12 218 patients were randomly assigned perindopril 8 mg once daily (n=6110), or matching placebo (n=6108). The mean follow-up was 4·2 years, and the primary endpoint was cardiovascular death, myocardial infarction, or cardiac arrest. Analysis was by intention to treat. Findings Mean age of patients was 60 years (SD 9), 85% were male, 92% were taking platelet inhibitors, 62% β blockers, and 58% lipid-lowering therapy. 603 (10%) placebo and 488 (8%) perindopril patients experienced the primary endpoint, which yields a 20% relative risk reduction (95% Cl 9–29, p=0·0003) with perindopril. These benefits were consistent in all predefined subgroups and secondary endpoints. Perindopril was well tolerated. Interpretation Among patients with stable coronary heart disease without apparent heart failure, perindopril can significantly improve outcome. About 50 patients need to be treated for a period of 4 years to prevent one major cardiovascular event. Treatment with perindopril, on top of other preventive medications, should be considered in all patients with coronary heart disease
    corecore