Absolute Transition Probabilities of Lines in the Spectra of Astrophysical Atoms, Molecules, and Ions

Progress in the investigation of absolute transition probabilities (A-values or F values) for ultraviolet lines is reported. A radio frequency ion trap was used for measurement of transition probabilities for intersystem lines seen in astronomical spectra. The intersystem line at 2670 A in Al II, which is seen in pre-main sequence stars and symbiotic stars, was studied

A Development Evaluation Study of a Professional Development Initiative to Strengthen Organizational Conditions in Early Education Settings

High quality instruction is essential to producing developmental gains for young children and can mitigate risk factors such as family poverty and low parental education. Even in programs with highly qualified teachers, teacher-child interactions often do not provide the level of instructional support that children need to be well-prepared for success in kindergarten. In order to improve instructional quality, an emerging focus on early childhood professional development involves supporting leaders in creating a web of supports for teacher learning and child growth. The purpose of the 3-year evaluation study was to assess the effectiveness of an Early Childhood Education Professional Development Initiative (ECE PDI) in advancing the knowledge, skills, and dispositions of community-based early childhood leaders and teachers in relation to creating the conditions for superior developmental outcomes for low-income students served by these community-based centers. Findings from the implementation and impact studies are reported

Absorption line series and autoionization resonance structure analysis in the ultraviolet spectrum of Sr I

Photoelectric spectrometer to measure absorption line series and autoionization resonance in ultraviolet spectrum of strontium vapo

The VerCors tool for verification of concurrent programs

The VerCors tool implements thread-modular static verification of concurrent programs, annotated with functional properties and heap access permissions. The tool supports both generic multithreaded and vector-based programming models. In particular, it can verify multithreaded programs written in Java, specified with JML extended with separation logic. It can also verify parallelizable programs written in a toy language that supports the characteristic features of OpenCL. The tool verifies programs by first encoding the specified program into a much simpler programming language and then applying the Chalice verifier to the simplified program. In this paper we discuss both the implementation of the tool and the features of its specification language

Probable absence of a quadrupolar spin-nematic phase in the bilinear-biquadratic spin-1 chain

We study numerically the ground-state phase diagram of the bilinear-biquadratic spin-1 chain near the ferromagnetic instability point, where the existence of a gapped or gapless nondimerized quantum nematic phase has been suggested. Our results, obtained by a highly accurate density-matrix renormalization-group (DMRG) calculation are consistent with the view that the order parameter characterizing the dimer phase vanishes only at the point where the system becomes ferromagnetic, although the existence of a gapped or gapless nondimerized phase in a very narrow parameter range between the ferromagnetic and the dimerized regimes cannot be ruled out.Comment: 6 pages, 6 figure

Navigation in Curved Space-Time

A covariant and invariant theory of navigation in curved space-time with respect to electromagnetic beacons is written in terms of J. L. Synge's two-point invariant world function. Explicit equations are given for navigation in space-time in the vicinity of the Earth in Schwarzschild coordinates and in rotating coordinates. The restricted problem of determining an observer's coordinate time when their spatial position is known is also considered

Magnetocaloric effect in integrable spin-s chains

We study the magnetocaloric effect for the integrable antiferromagnetic high-spin chain. We present an exact computation of the Gr\"uneisen parameter, which is closely related to the magnetocaloric effect, for the quantum spin-s chain on the thermodynamical limit by means of Bethe ansatz techniques and the quantum transfer matrix approach. We have also calculated the entropy S and the isentropes in the (H,T) plane. We have been able to identify the quantum critical points H_c^{(s)}=2/(s+1/2) looking at the isentropes and/or the characteristic behaviour of the Gr\"uneisen parameter.Comment: 6 pages, 3 figure