Limit of the Solutions for the Finite Horizon Problems as the Optimal Solution to the Infinite Horizon Optimization Problems

We aim to generalize the results of Cai and Nitta (2007) by allowing both the utility and production function to depend on time. We also consider an additional intertemporal optimality criterion. We clarify the conditions under which the limit of the solutions for the finite horizon problems is optimal among all attainable paths for the infinite horizon problems under the overtaking criterion, as well as the conditions under which such a limit is the unique optimum under the sum-of-utilities criterion. The results are applied to a parametric example of the one-sector growth model to examine the impacts of discounting on optimal paths

Constraining spacetime torsion with LAGEOS

We compute the corrections to the orbital Lense-Thirring effect (or frame-dragging) in the presence of spacetime torsion. We derive the equations of motion of a test body in the gravitational field of a rotating axisymmetric massive body, using the parametrized framework of Mao, Tegmark, Guth and Cabi. We calculate the secular variations of the longitudes of the node and of the pericenter. We also show how the LAser GEOdynamics Satellites (LAGEOS) can be used to constrain torsion parameters. We report the experimental constraints obtained using both the nodes and perigee measurements of the orbital Lense-Thirring effect. This makes LAGEOS and Gravity Probe B (GPB) complementary frame-dragging and torsion experiments, since they constrain three different combinations of torsion parameters

A New Framework for Music Education Knowledge and Skill

This study investigates perceptions of secondary school band and orchestra teachers regarding the relative importance of knowledge and skill categories to professional success, using a framework modeled after Schulman (1986, 1987). Band and orchestra teachers in secondary schools (N = 214) complete an anonymous, online survey ranking the relative importance of various knowledge and skill categories. Participants rank pedagogical content knowledge, content knowledge, and general pedagogical knowledge highest. There are no significant differences in the rankings of the categories among various subgroups at the p < .05 level. Results confirm the applicability of Schulman's model to music education. This framework has implications for undergraduate, graduate, and continuing professional education. Analysis of categories' interaction provides insight into effective classroom instruction.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

THE RATE OF BINARY BLACK HOLE MERGERS INFERRED FROM ADVANCED LIGO OBSERVATIONS SURROUNDING GW150914

A transient gravitational-wave signal, GW150914, was identi fi ed in the twin Advanced LIGO detectors on 2015 September 2015 at 09:50:45 UTC. To asse ss the implications of this discovery, the detectors remained in operation with unchanged con fi gurations over a period of 39 days around the time of t he signal. At the detection statistic threshold corresponding to that observed for GW150914, our search of the 16 days of simultaneous two-detector observational data is estimated to have a false-alarm rate ( FAR ) of < ́ -- 4.9 10 yr 61 , yielding a p -value for GW150914 of < ́ - 210 7 . Parameter estimation follo w-up on this trigger identi fi es its source as a binary black hole ( BBH ) merger with component masses ( )( ) = - + - + mm M ,36,29 12 4 5 4 4 at redshift = - + z 0.09 0.04 0.03 ( median and 90% credible range ) . Here, we report on the constraints these observations place on the rate of BBH coalescences. Considering only GW150914, assuming that all BBHs in the universe have the same masses and spins as this event, imposing a search FAR threshold of 1 per 100 years, and assuming that the BBH merger rate is constant in the comoving frame, we infer a 90% credible range of merger rates between – -- 2 53 Gpc yr 31 ( comoving frame ) . Incorporating all search triggers that pass a much lower threshold while accounting for the uncerta inty in the astrophysical origin of each trigger, we estimate a higher rate, ranging from – -- 13 600 Gpc yr 31 depending on assumptions about the BBH mass distribution. All together, our various rate estimat es fall in the conservative range – -- 2 600 Gpc yr 31

Natural phenomena hazards evaluation of equipment and piping of Gaseous Diffusion Plant Uranium Enrichment Facility

In support of the Gaseous Diffusion Plant Safety Analysis Report Upgrade program (GDP SARUP), a natural phenomena hazards evaluation was performed for the main process equipment and piping in the uranium enrichment buildings at Paducah and Portsmouth gaseous diffusion plants. In order to reduce the cost of rigorous analyses, the evaluation methodology utilized a graded approach based on an experience data base collected by SQUG/EPRI that contains information on the performance of industrial equipment and piping during past earthquakes. This method consisted of a screening walkthrough of the facility in combination with the use of engineering judgment and simple calculations. By using these screenings combined with evaluations that contain decreasing conservatism, reductions in the time and cost of the analyses were significant. A team of experienced seismic engineers who were trained in the use of the DOE SQUG/EPRI Walkdown Screening Material was essential to the success of this natural phenomena hazards evaluation

THE DEVELOPMENT OF HIGH PURITY TANTALUM AND ALLOYS FOR LIQUID PLUTONIUM CONTAINMENT IN LAMPRE I

By combining arc casting and electron beam melting, spectroscopically pure tantalum and alloys, suitable for containment of molten Pu-Fe alloys, were produced. The 0.1% W alloy was used for the first LAMPRE loading. The effects of a large number of additives on the corrosion resistance of tantalum were tested. Additions of up to 10% tungsten gave increasing endurance. Specimens of tantalum irradiated with neutrons until 3% converted to tungsten were stitl satisfactory in mechanical properties for reactor use. Either tungsten or the traces of yttrium remaining after arc melting can raise the one-hour recryatatlization temperature of tantalum by 400 deg C. Effects of internal strain, critical strain and precipitation hardening in tantalum alloys were studied. High-temperature annealed tantalum had superior corrosion resistance, while impact extruded and ironed material was better than deep-drawn metal. Mechanical tests on tantalum with added interstitial elements showed that their presence to the extent expected in LAMPRE would be unlikely to weaken the tantalum. Evidence was found that oxygen promotes plutonium attack on tantalum. Small amounts of hydrogen, nitrogen and carbon had no effect on corrosion. (auth