Effects of turbulent dust grain motion to interstellar chemistry

Theoretical studies have revealed that dust grains are usually moving fast through the turbulent interstellar gas, which could have significant effects upon interstellar chemistry by modifying grain accretion. This effect is investigated in this work on the basis of numerical gas-grain chemical modeling. Major features of the grain motion effect in the typical environment of dark clouds (DC) can be summarised as follows: 1) decrease of gas-phase (both neutral and ionic) abundances and increase of surface abundances by up to 2-3 orders of magnitude; 2) shifts of the existing chemical jumps to earlier evolution ages for gas-phase species and to later ages for surface species by factors of about ten; 3) a few exceptional cases in which some species turn out to be insensitive to this effect and some other species can show opposite behaviors too. These effects usually begin to emerge from a typical DC model age of about 10^5 yr. The grain motion in a typical cold neutral medium (CNM) can help overcome the Coulomb repulsive barrier to enable effective accretion of cations onto positively charged grains. As a result, the grain motion greatly enhances the abundances of some gas-phase and surface species by factors up to 2-6 or more orders of magnitude in the CNM model. The grain motion effect in a typical molecular cloud (MC) is intermediate between that of the DC and CNM models, but with weaker strength. The grain motion is found to be important to consider in chemical simulations of typical interstellar medium.Comment: 20 pages, 10 figures and 2 table

Searching for radiative pumping lines of OH masers: II. The 53.3um absorption line towards 1612MHz OH maser sources

This paper analyzes the 53.3um line in the ISO LWS spectra towards a similar sample of OH/IR sources. We find 137 LWS spectra covering 53.3um and associated with 47 galactic OH/IR sources. Ten of these galactic OH/IR sources are found to show and another 5 ones tentatively show the 53.3um absorption while another 7 sources highly probably do not show this line. The source class is found to be correlated with the type of spectral profile: red supergiants (RSGs) and AGB stars tend to show strong blue-shifted filling emission in their 53.3um absorption line profiles while HII regions tend to show a weak red-shifted filling emission in the line profile. GC sources and megamasers do not show filling emission feature. It is argued that the filling emission might be the manifestation of an unresolved half emission half absorption profile of the 53.3um doublet. The 53.3 to 34.6um equivalent width (EW) ratio is close to unity for RSGs but much larger than unity for GC sources and megamasers while H II regions only show the 53.3um line. The pump rate defined as maser to IR photon flux ratio is approximately 5% for RSGs. The pump rates of GC sources are three order of magnitude smaller. Both the large 53.3 to 34.6um EW ratio and the small pump rate of the GC OH masers reflect that the two detected `pumping lines' in these sources are actually of interstellar origin. The pump rate of Arp 220 is 32%--much larger than that of RSGs, which indicates that the contribution of other pumping mechanisms to this megamaser is important.Comment: 34 pages, 12 figures, 4 table

Effects of Australian Economic Activities on Waste Generation and Treatment

Understanding the relationships between the Australian economic system and waste generation from intermediate sectors and households is a prerequisite for planning and implementing waste management strategies at a national scale. Data of waste generation accounts link to those of national economic accounts. However, in Australia, some years’ data are absent and so these links cannot be made. To rectify this data gap, this paper interpolates and extrapolates the Australian input-output table (IOT) of 2010–2011. Waste input-output (WIO) analysis is then used to assess the effects of the Australian economy on waste generation and treatment between 2009–2010 and 2010–2011. Analysis indicated that the result of interpolation was more reasonable than that of extrapolation, and the interpolation of the Australian IOT of 2010–2011 can be applicable. This comparative analysis of the time series data in WIO model has identified that: (1) per million $AUD of output of the Construction sector generated the most amount of direct and total waste during the period; (2) the relationships between the development of Australian economy and waste generation illustrate that the Australian economy is currently a traditional linear economy; (3) the effectiveness of waste-related policies are shown by the growth of the sums of direct and total effects of intermediate sectors on the Recovery sector; and (4) the amount of waste generated by households increased sharply over the two years. The physical flows of waste footprint show details of waste generation and treatment in the Australian economic system. The information provided in this paper is beneficial to formulate tailor-made policies for waste management in Australia

Solar transition region in the quiet Sun and active regions

The solar transition region (TR), in which above the photosphere the tempera- ture increases rapidly and the density drops dramatically, is believed to play an important role in coronal heating and solar wind acceleration. Long-lasting up-flows are present in the upper TR and interpreted as signatures of mass supply to large coronal loops in the quiet Sun. Coronal bright points (BPs) are local heating phenomena and we found a different Doppler-shift pattern at TR and coronal temperatures in one BP, which might be related to the twisted loop system. The dominant energy loss in the lower TR is the Ly-alpha emission. It has been found that most Ly-alpha radiance profiles are stronger in the blue peak, an asymmetry opposite to higher order Lyman lines. This asymmetry is stronger when the downflow in the middle TR is stronger, indicating that the TR flows play an important role in the line formation process. The peak separation of Ly-alpha is found to be larger in coronal holes than in the quiet Sun, reflecting the different magnetic structures and radiation fields between the two regions. The Lyman line profiles are found to be not reversed in sunspot plume and umbra regions, while they are obviously reversed in the surrounding plage region. At TR temperatures, the densities of the sunspot plume and umbra are a factor of 10 lower than of the plage, indicating that the sunspot plasma emitting at TR temperatures is higher and possibly more extended above sunspots than above the plage region.Comment: This paper has been withdrawn by the author because it's not a referred pape

Scales of Fermion Mass Generation and Electroweak Symmetry Breaking

The scale of mass generation for fermions (including neutrinos) and the scale for electroweak symmetry breaking (EWSB) can be bounded from above by the unitarity of scattering involving longitudinal weak gauge bosons or their corresponding would-be Goldstone bosons. Including the exact n-body phase space we analyze the 2 --> n ($n \geq 2$) processes for the fermion-(anti)fermion scattering into multiple gauge boson final states. Contrary to naive energy power counting, we demonstrate that as $n$ becomes large, the competition between an increasing energy factor and a phase-space suppression leads to a {\it strong new upper bound} on the scale of fermion mass generation at a finite value $n=n_s$, which is {\it independent of the EWSB scale,} $v = (\sqrt{2}G_F)^{-1/2}$. For quarks, leptons and Majorana neutrinos, the strongest 2 --> n limits range from about 3TeV to 130-170TeV (with $2\lesssim n_s \lesssim 24$), depending on the measured fermion masses. Strikingly, given the tiny neutrino masses as constrained by the neutrino oscillations, neutrinoless double-beta decays and astrophysical observations, the unitarity violation of $\nu_L\nu_L\to nW_L^a$ scattering actually occurs at a scale no higher than ~170 TeV. Implications for various mechanisms of neutrino mass generation are analyzed. On the other hand, for the 2 --> n pure Goldstone-boson scattering, we find that the decreasing phase space factor always dominates over the growing overall energy factor when $n$ becomes large, so that the best unitarity bound on the scale of EWSB remains at n=2.Comment: 67pp, to match PRD (minor typos fixed