Roughness of moving elastic lines - crack and wetting fronts

We investigate propagating fronts in disordered media that belong to the universality class of wetting contact lines and planar tensile crack fronts. We derive from first principles their nonlinear equations of motion, using the generalized Griffith criterion for crack fronts and three standard mobility laws for contact lines. Then we study their roughness using the self-consistent expansion. When neglecting the irreversibility of fracture and wetting processes, we find a possible dynamic rough phase with a roughness exponent of $\zeta=1/2$ and a dynamic exponent of z=2. When including the irreversibility, we conclude that the front propagation can become history dependent, and thus we consider the value $\zeta=1/2$ as a lower bound for the roughness exponent. Interestingly, for propagating contact line in wetting, where irreversibility is weaker than in fracture, the experimental results are close to 0.5, while for fracture the reported values of 0.55--0.65 are higher.Comment: 15 pages, 6 figure

A 30 GHz 5-TeV Linear Collider

We present parameters for a linear collider with a $3$ to $5$ TeV center-of-mass energy that utilizes conventional rf technology operating at a frequency around 30 GHz. We discuss the scaling laws and assumed limitations that lead to the parameters described and we compare the merits and liabilities of different technological options including rf power source, accelerator structure, and final focus system design. Finally, we outline the components of the collider while specifying the required alignment and construction tolerances

A titanium-nitride near-infrared kinetic inductance photon-counting detector and its anomalous electrodynamics

We demonstrate single-photon counting at 1550 nm with titanium-nitride (TiN) microwave kinetic inductance detectors. Energy resolution of 0.4 eV and arrival-time resolution of 1.2 microseconds are achieved. 0-, 1-, 2-photon events are resolved and shown to follow Poisson statistics. We find that the temperature-dependent frequency shift deviates from the Mattis-Bardeen theory, and the dissipation response shows a shorter decay time than the frequency response at low temperatures. We suggest that the observed anomalous electrodynamics may be related to quasiparticle traps or subgap states in the disordered TiN films. Finally, the electron density-of-states is derived from the pulse response.Comment: 4 pages, 3 figure

Cats and Dogs, Hair and A Hero: A Quintet of New Milky Way Companions

We present five new satellites of the Milky Way discovered in Sloan Digital Sky Survey (SDSS) imaging data, four of which were followed-up with either the Subaru or the Isaac Newton Telescopes. They include four probable new dwarf galaxies -- one each in the constellations of Coma Berenices, Canes Venatici, Leo and Hercules -- together with one unusually extended globular cluster, Segue 1. We provide distances, absolute magnitudes, half-light radii and color-magnitude diagrams for all five satellites. The morphological features of the color-magnitude diagrams are generally well described by the ridge line of the old, metal-poor globular cluster M92. In the last two years, a total of ten new Milky Way satellites with effective surface brightness mu_v >~ 28 mag/sq. arcsec have been discovered in SDSS data. They are less luminous, more irregular and appear to be more metal-poor than the previously-known nine Milky Way dwarf spheroidals. The relationship between these objects and other populations is discussed. We note that there is a paucity of objects with half-light radii between ~40 pc and ~ 100 pc. We conjecture that this may represent the division between star clusters and dwarf galaxies.Comment: 10 pages, 8 figures, submitted to the Astrophysical Journa

The Hercules-Aquila Cloud

We present evidence for a substantial overdensity of stars in the direction of the constellations of Hercules and Aquila. The Cloud is centered at a Galactic longitude of about 40 degrees and extends above and below the Galactic plane by at least 50 degrees. Given its off-centeredness and height, it is unlikely that the Hercules-Aquila Cloud is related to the bulge or thick disk. More likely, this is a new structural component of the Galaxy that passes through the disk. The Cloud stretches about 80 degrees in longitude. Its heliocentric distance lies between 10 and 20 kpc so that the extent of the Cloud in projection is roughly 20 kpc by 15 kpc. It has an absolute magnitude of -13 and its stellar population appears to be comparable to, but somewhat more metal-rich than, M92.Comment: ApJ (Letters), in pres

Sequestration of Martian CO2 by mineral carbonation

Carbonation is the water-mediated replacement of silicate minerals, such as olivine, by carbonate, and is commonplace in the Earth’s crust. This reaction can remove significant quantities of CO2 from the atmosphere and store it over geological timescales. Here we present the first direct evidence for CO2 sequestration and storage on Mars by mineral carbonation. Electron beam imaging and analysis show that olivine and a plagioclase feldspar-rich mesostasis in the Lafayette meteorite have been replaced by carbonate. The susceptibility of olivine to replacement was enhanced by the presence of smectite veins along which CO2-rich fluids gained access to grain interiors. Lafayette was partially carbonated during the Amazonian, when liquid water was available intermittently and atmospheric CO2 concentrations were close to their present-day values. Earlier in Mars’ history, when the planet had a much thicker atmosphere and an active hydrosphere, carbonation is likely to have been an effective mechanism for sequestration of CO2

Evidence for Magnetic Pseudoscaling in Overdoped La(2-x)Sr(x)CuO(4)

We report the results of electronic Raman scattering experiments on an overdoped La(1.78)Sr(0.22)CuO(4) single crystal as a function of temperature. The scattering rate Gamma(w->0,T) has been determined from the normal state B(1g) spectra in the range 50 K < T < 300 K. Gamma(T) decreases linearly from 300 K to about 175 K and then undergoes a reduction with respect to the expected mean-field behavior. This trend suggests a crossover to pseudoscaling regime at about T(cr)=160 K. The results are in good agreement with the prediction of the nearly antiferromagnetic Fermi liquid model. There is no evidence of a pseudogap in the spectra obtained from this overdoped sample.Comment: RevTex, 4 pages with 3 PS figures included, replaced with minor changes in the text and reference

Bottom sediments of Lake Rotoma

Lake Rotoma is a deep (70-80 m), oligotrophic, warm monomictic lake of volcanic origin with insignificant stream inflow and no clearly defined outflow. For at least 60 years up to 1972 the lake level fluctuated markedly about an overall rising trend of some 6-10 m. Nearshore profiles are related to the prevailing wave climate superimposed upon the overall rising lake level, shelves being wider, less steep, and deeper about the more exposed eastern and southern shorelines. The outer portions of shelves extending well below modern storm wave base into waters as deep as 15-25 m are relict features from lower lake level stands. Sediments fine from sand-gravel mixtures nearshore to silts in basinal areas. Their composition reflects a composite provenance involving the lavas and tephras about the lake, as well as intralake diatom frustules and organic matter. The distribution pattern of surficial bottom sediments is an interplay between grains of both biological and terrigenous origin, supplied presently and in the past by a variety of processes, that have been dispersed either by the modern hydrodynamic regime or by former ones associated with lower lake levels. These interrelationships are structured by erecting 5 process-age sediment classes in the lake, namely neoteric, amphoteric, proteric, palimpsest, and relict sediments, analogous to categories postulated for sediments on oceanic continental shelves. Short-core stratigraphy includes the Kaharoa (A.D. -1020) and Tarawera (A.D. 1886) tephras. The rates of sedimentation of diatomaceous silts in basinal areas have more than doubled since the Tarawera eruption, indicating an overall increase in the fertility level of lake waters associated, perhaps, with recent farm development in the catchment