Polarized galactic synchrotron and dust emission and their correlation

We present an analysis of the level of polarized dust and synchrotron emission using the WMAP9 and Planck data. The primary goal of this study is to inform the assessment of foreground contamination in the cosmic microwave background (CMB) measurements below $\ell\sim200$ from 23 to 353 GHz. We compute angular power spectra as a function of sky cut based on the Planck 353 GHz polarization maps. Our primary findings are the following. (1) There is a spatial correlation between the dust emission as measured by Planck at 353 GHz and the synchrotron emission as measured by WMAP at 23 GHz with $\rho\approx0.4$ or greater for $\ell<20$ and $f_{\mathrm{sky}}\geq0.5$, dropping to $\rho\approx0.2$ for $30<\ell<200$. (2) A simple foreground model with dust, synchrotron, and their correlation fits well to all possible cross spectra formed with the WMAP and Planck 353 GHz data given the current uncertainties. (3) In the 50$\%$ cleanest region of the polarized dust map, the ratio of synchrotron to dust amplitudes at 90 GHz for 50 $\leq \ell \leq$110 is $0.3_{-0.2}^{+0.3}$. Smaller regions of sky can be cleaner although the uncertainties in our knowledge of synchrotron emission are larger. A high-sensitivity measurement of synchrotron below 90 GHz will be important for understanding all the components of foreground emission near 90 GHz.Comment: 10 pages, 8 figures; Published in JCAP. Source masks updated, minor change

A discovery and analysis of influencing factors of pair programming

The exploration into the underlying psychosocial links of pair programming. a new and unorthodox programming paradigm in which two programmers share one keyboard and monitor during real-time programming sessions, is undertaken. These complex psychosocial relationships, along with cognitive process exchanges, ultimately mold the programming output as well as determine the level of communication, satisfaction. confidence and compatibility. Laying the framework for this research, a through review of traditional and contemporary paradigms with a special focus on their limitations and a list of current software development problems are presented. Next, a detailed summary of pair programming and related agile software paradigms, such as extreme programming, which lists pair programming as one of its twelve principles, is given. From earlier pair programming studies, a number of programming benefits have been unveiled and these are listed and discussed. However, a lack of formal studies pertaining to the psychosocial aspects of pair programming exists. Given this void, a field survey is administered to a group of professional programmers and a resulting list of influencing factors on pair programming emerges. From the list, the most popular factor, personality, and two other factors, communication and gender, have been selected in order to study their impact on pair programming product outcome and the level of communication, satisfaction, confidence and compatibility. An experiment focusing on these factors is designed and implemented. From the experimental findings, the personality of the two partners in pair programming is found to have a significant impact on the pair programming output. Also, it is discovered that same gender pairs exhibited an unusually high level of communication, satisfaction and compatibility between each other, especially among female-female pairs. A detailed statistical experiment result based on research hypotheses is reported

Thermal annealing of arsenic tri-sulphide thin film and its influence on device performance

Arsenic tri-sulphide (As₂S₃)thin filmwaveguides have been used successfully as nonlinear optical devices for all-optical signal processors. For such devices, low propagation loss is vital if high performance is to be obtained. In this study, thermal annealing was employed not only to stabilize the physical properties of the films, but also to reduce the sources of light attenuation in the as-deposited material. Here we investigated heat-induced changes to the microstructure and optical properties of As₂S₃thin films and, based on this information, determined the best annealing conditions. The refractive index of the films rises with annealing due to thermal densification and increased heteropolar bond density. The growth of surface roughness and thermal stress in the film, however, limits the annealing temperature to ∼130 °C. We fabricated and analyzed waveguides produced from as-deposited and annealedfilms and found that the propagation loss of the guides dropped by ∼0.2 dB/cm as a result of appropriate annealing.Rayleigh scattering and absorption from defects associated with phase separation, homopolar bonds, voids, and dangling bonds in the as-deposited film are shown to contribute to the higher light attenuation in unannealed films.This research was supported by the Australian Research Council through its Centre of Excellence program

Intravital microscopic interrogation of peripheral taste sensation

Intravital microscopy is a powerful tool in neuroscience but has not been adapted to the taste sensory organ due to anatomical constraint. Here we developed an imaging window to facilitate microscopic access to the murine tongue in vivo. Real-time two-photon microscopy allowed the visualization of three-dimensional microanatomy of the intact tongue mucosa and functional activity of taste cells in response to topically administered tastants in live mice. Video microscopy also showed the calcium activity of taste cells elicited by small-sized tastants in the blood circulation. Molecular kinetic analysis suggested that intravascular taste sensation takes place at the microvilli on the apical side of taste cells after diffusion of the molecules through the pericellular capillaries and tight junctions in the taste bud. Our results demonstrate the capabilities and utilities of the new tool for taste research in vivo

Polarization-independent chalcogenide glass nanowires with anomalous dispersion for all-optical processing

We demonstrate the design and fabrication of square Ge11.5As24Se64.5 (Ge11) nonlinear nanowires fully embedded in a silica cladding for polarization independent (P-I) nonlinear processing. We observed similar performance for FWM using both TE and TM modes confirming that a near P-I operation was obtained. In addition we find that the supercontinuum spectrum that can be generated in the nanowires using 1ps pulse pulses with around 30W peak power was independent of polarization

The Impact of Thermal- and Photo-annealing of Chalcogenide Films for Optical Waveguides

We applied thermal- and band-edge light annealing on an as-deposited As2S3 film to mitigate its phase separation and, thus to improve the propagation losses of fabricated optical waveguides. Studies of the film micro structure revealed a difference between atomic bonds and linked phases among the as-deposited, thermally-annealed, and optically-annealed films. We fabricated rib-type waveguides with 4 micron width from 0.85 μm thick films, and measured the insertion losses. Around 0.4 and 0.2 dB/cm propagation losses were obtained in the waveguides produced from as-deposited and annealed films, respectively. The waveguides produced from photo-annealed film showed almost the same propagation losses to those from thermally-annealed material. Our results, however, indicate optical-annealing provides some advantages over thermal annealing for waveguide fabrication, such as the absence of film cracking which observed at high temperature processing

Nanoscale phase separation in ultrafast pulsed laser deposited arsenic trisulfide (As₂S₃) films and its effect on plasma etching

We have observed nanoscale phase separation in amorphous arsenic trisulfide (As₂S₃)films produced by ultrafast pulsed laser deposition and its effect on the surface morphology of the film after plasma etching. When the film was etched in CF₄–O₂plasma, a grainy structure was observed on the surface. From Raman and x-ray photoelectron spectroscopies, we concluded that the grainy structure of the etchedsurfaces comes from the differential chemical attack between different phases in the film.This research was supported by the Australian Research Council through its Centres of Excellence and Federation Fellow Programs

High index contrast polysiloxane waveguides fabricated by dry etching

The authors demonstrate the production of low loss enhanced index contrast waveguides by reactive ion etching of IPG™ polysiloxane thin films. The use of a silica mask and CHF₃∕O₂etch gas led to large etch selectivity between the silica and IPG™ of >20 and etch rates of >100nm∕min. This work indicates that compact optical circuits could be successfully fabricated for telecommunication applications using polysiloxane films.The support of the Australian Research Council through its Linkage grant and Federation Fellow programs is gratefully acknowledged as well as the financial support of RPO Inc