Improvement of irregular dtm for sph modelling of flow-like landslides

Irregular topography of real slopes largely affects the propagation stage of flowlike landslides and accurate digital terrain models (DTMs) are absolutely necessary for realistic simulations and assessments. In this paper a simple yet effective method is proposed to improve the accuracy of existing DTMs which is applied to the topographical models used in well equipped laboratory experiments. Aimed at evaluating the effects of different DTMs in the results of the propagation modelling, a depth-integrated SPH model is used to simulate two series of laboratory tests referring to a frictional rheological model while using either the available DTM or the DTM improved through the proposed procedure. The obtained results show that the proposed method provides a more accurate topographical model for all the analyzed cases. Particularly, the new topographical model allows better reproducing the laboratory evidences in terms of run-out distances, inundated areas and geometrical characteristics of the final deposits. Furthermore, SPH analyses with progressively finer topographical inputs outline the role of DTM’s precision towards the accuracy of the numerical simulations

Measuring the star formation rate with gravitational waves from binary black holes

A measurement of the history of cosmic star formation is central to understand the origin and evolution of galaxies. The measurement is extremely challenging using electromagnetic radiation: significant modeling is required to convert luminosity to mass, and to properly account for dust attenuation, for example. Here we show how detections of gravitational waves from inspiraling binary black holes made by proposed third-generation detectors can be used to measure the star formation rate of massive stars with high precision up to redshifts of ~10. Depending on the time-delay model, the predicted detection rates ranges from ~1400 to ~16000 per month with the current measurement of local merger rate density. With three months of observations, parameters describing the volumetric star formation rate can be constrained at the few percent level, and the volumetric merger rate can be directly measured to 3% at z~2. Given a parameterized star formation rate, the characteristic delay time between binary formation and merger can be measured to ~60%.Comment: 7 pages, 1 table, 4 fig

Attitudes and Perspectives of Teacher Performers on Pedagogy and Perceived Student Learning in the Elementary and Secondary School Music Classroom

This study investigated the lives of three active music teacher performers and how their performing experience impacted pedagogy and perceived student learning in the classroom. At the time of data collection, one participant was a full-time elementary school music teacher, and the other two participants were full-time secondary school music teachers. Philosophically, this study intended to discover the central meaning underlying the life experiences of each participant as they relate to pedagogy and perceived student learning (phenomenology). Methodologically, qualitative data (typical of phenomenological inquiry) were collected through both interviews and a focus group session. Furthermore, a traditional thematic exploration of the data was employed. Findings indicate that pedagogy and perceived student learning are positively impacted through the theme of respect and negatively impacted through the themes of fatigue and job dissatisfaction. Such themes invite all educators within the performing arts to reexamine and reflect upon the intricate relationship between performing and teaching

An Analysis of Teacher Selection Tools in Pennsylvania

The purpose of this study was to examine teacher screening and selection tools currently being utilized by public school districts in Pennsylvania and to compare these tools to the research on qualities of effective teachers. The researcher developed four research questions that guided her study. The Pennsylvania Association of School Personnel Administrators (PASPA) granted the researcher permission to survey their members. PASPA's Executive Director sent an e-mail describing the study and invited his members to participate in the electronic survey. The e-mail asked members to click on a link that took them to a 10-15 minute survey about teacher selection tools. Fifty-five members completed the survey, with a total response rate of 32 percent. Quantitative data were analyzed using, percentages, means and standard deviations. Qualitative analysis was used to interpret data obtained from open-ended questions.The results of the study indicated that approximately 71% of reporting Pennsylvania public schools were utilizing some type of electronic on-line warehousing database for which to search and screen potential teacher candidates. However, a low number of reporting school districts were not using any type of commercial product for screening or interviewing candidates. Further, 93% of reporting school districts were using locally created interview questions. Finally, participants indicated that the top three factors considered when hiring a teacher were the candidate's: knowledge of teaching and learning, content knowledge, and knowledge of good classroom practices. There were insufficient data to determine if the commercial or locally created teacher selection tools were linked to the qualities of effective teachers

Measuring the LISA test mass magnetic proprieties with a torsion pendulum

Achieving the low frequency LISA sensitivity requires that the test masses acting as the interferometer end mirrors are free-falling with an unprecedented small degree of deviation. Magnetic disturbances, originating in the interaction of the test mass with the environmental magnetic field, can significantly deteriorate the LISA performance and can be parameterized through the test mass remnant dipole moment $\vec{m}_r$ and the magnetic susceptibility $\chi$. While the LISA test flight precursor LTP will investigate these effects during the preliminary phases of the mission, the very stringent requirements on the test mass magnetic cleanliness make ground-based characterization of its magnetic proprieties paramount. We propose a torsion pendulum technique to accurately measure on ground the magnetic proprieties of the LISA/LTP test masses.Comment: 6 pages, 3 figure

Effect of Corn Price on Profitability of Control Vs Phytase Enhanced Diet of Hogs

Economic Simulation model (SIMETAR) was used to investigate the effect of future corn price on profitability of control and phytase enhanced diet of hogs. The completed simulation model was used to estimate probability distribution for control vs lower excretion diet profitability under different corn prices. Data used was collected from recent field trials in Oklahoma that tested the effect of phytase enhanced diets on reducing phosphorus emission. The results showed that as the market price of corn increases control diet will be more profitable than phytase enhanced diet, given the cost of other remaining feed ingredient is constant for both the diets.profitability, SIMETAR, control diet, phytase enhanced diet, swine, Production Economics,

Galaxy evolution across the optical emission-line diagnostic diagrams?

The discovery of the M-sigma relation, the local galaxy bimodality, and the link between black-hole and host-galaxy properties, have raised the question whether AGN play a role in galaxy evolution. Several theoretical models implement AGN feedback to explain the observed galaxy luminosity function, and possibly the color and morphological transformation of spiral galaxies into passive ellipticals. To understand the importance of AGN feedback, a study of the AGN populations in the radio-optical domain is crucial. A mass sequence linking star-forming galaxies and AGN has been already noted in previous works, and it is now investigated as possible evolutionary sequence. We observed a sample of 119 intermediate-redshift (0.04<z<0.4) SDSS-FIRST radio emitters with the Effelsberg 100-m telescope at 4.85 and 10.45 GHz and obtained spectral indices. We find indications of spectral index flattening in high-metallicity star-forming galaxies, composite galaxies, and Seyferts. This "flattening sequence" along the [NII]-based emission-line diagnostic diagram is consistent with the hardening of galaxy ionizing field, due to nuclear activity. After combining our data with FIRST measurements at 1.4 GHz, we find that the three-point radio spectra of Seyferts and LINERs show substantial differences, attributable to small radio core components and larger (arcsecond sized) jet/lobe components, respectively. A visual inspection of FIRST images seems to confirm this hypothesis. Galaxies along this sequence are hypothesized to be transitioning from the active star-forming galaxies (blue cloud) to the passive elliptical galaxies (red sequence). This supports the suggestion that AGN play a role in shutting down star-formation, and allow the transition from one galaxy class to the other.Comment: 20 pages, 19 figures, accepted for publication in A&

The Development of a Control System for a 5 Kilowatt Free Piston Stirling Engine Convertor

The new NASA Vision for Exploration, announced by President Bush in January 2004, proposes an ambitious program that plans to return astronauts to the moon by the 2018 time frame. A recent NASA study entitled "Affordable Fission Surface Power Study" recommended a 40 kWe, 900 K, NaK-cooled, Stirling convertors for 2020 launch. Use of two of the nominal 5 kW convertors allows the system to be dynamically balanced. A group of four dual-convertor combinations that would yield 40 kWe can be tested to validate the viability of Stirling technology for space fission surface power systems. The work described in this paper deals specifically with the control system for the 5 kW convertor described in the preceding paragraph. This control system is responsible for maintaining piston stroke to a setpoint in the presence of various disturbances including electrical load variations. Pulse starting of the Free Piston Stirling Engine (FPSE) convertor is also an inherent part of such a control system. Finally, the ability to throttle the engine to match the required output power is discussed in terms of setpoint control. Several novel ideas have been incorporated into the piston stroke control strategy that will engender a stable response to disturbances in the presence of midpoint drift while providing useful data regarding the position of both the power piston and displacer