Caltech Faint Galaxy Redshift Survey XV: Classification of Galaxies with 0.2 < z < 1.1 in the Hubble Deep Field (North) and its Flanking Fields

To circumvent the spatial effects of resolution on galaxy classification, the images of 233 objects of known redshift in the Hubble Deep Field (HDF) and its Flanking Fields (FF) that have redshifts in the range 0.20 < z < 1.10 were degraded to the resolution that they would have had if they were all located at a redshift z= 1.00. As in paper XIV of the present series, the effects of shifts in rest wavelength were mitigated by using R-band images for the classification of galaxies with 0.2 < z < 0.6 and I-band images for objects with redshifts 0.6 < z < 1.1. A special effort was made to search for bars in distant galaxies. The present data strongly confirm the previous conclusion that the Hubble tuning fork diagram only provides a satisfactory framework for the classification of galaxies with z ~< 0.3. More distant disk galaxies are often difficult to shoehorn into the Hubble classification scheme. The paucity of barred spirals and of grand-design spirals at large redshifts is confirmed. It is concluded that the morphology of disk galaxies observed at look-back times smaller than 3--4 Gyr differs systematically from that of more distant galaxies viewed at look-back times of 4--8 Gyr. The disks of late-type spirals at z >0.5 are seen to be more chaotic than those of their nearer counterparts. Furthermore the spiral structure in distant early-type spirals appears to be less well-developed than it is in nearby early-galaxies.Comment: Accepted for publication in the A

The Two Fluid Drop Snap-off Problem: Experiments and Theory

We address the dynamics of a drop with viscosity $\lambda \eta$ breaking up inside another fluid of viscosity $\eta$. For $\lambda=1$, a scaling theory predicts the time evolution of the drop shape near the point of snap-off which is in excellent agreement with experiment and previous simulations of Lister and Stone. We also investigate the $\lambda$ dependence of the shape and breaking rate.Comment: 4 pages, 3 figure

Caltech Faint Galaxy Redshift Survey XIV: Galaxy Morphology in the HDF (North) and its Flanking Fields to z=1.2

Morphological classifications are reported for Hubble Space Telescope (HST) images of 241 galaxies in the Hubble Deep Field (HDF) and its Flanking Fields (FF) with measured redshifts in the interval 0.25 < z < 1.2, drawn from a magnitude-limited redshift survey to R = 24.0. The galaxies are divided into three groups with redshifts in the intervals [0.25,0.6], [0.6,0.8], [0.8,1.2]. R606 images from the first group and I814 images from the second and third groups are compared with B-band images of nearby galaxies. All classifications were therefore made at approximately the same rest wavelength. Selection biases are discussed. We corroborate and extend the results of earlier investigations by observing that: Most intermediate and late-type galaxies with $z\gtrsim0.5$ have morphologies that are dramatically different from those of local galaxies and cannot be shoehorned into the Hubble ``tuning fork'' classification scheme. Grand-design spirals appear to be rare or absent for $z\gtrsim0.3$. Many Sa and Sb spirals with $z\gtrsim0.6$ do not exhibit well-defined spiral arms. The arms of distant Sc galaxies appear more chaotic than those of their nearby counterparts. (abridged) On the basis of these and similar observations, it is inferred that the development of pronounced spiral structure was delayed until \~5 Gyr and that most bulges are probably not formed by disintegrating bars. Major morphological changes were still taking place only ~5 Gyr ago even though changes in the integrated light of most galaxies were then much slower than they were ~10 Gyr ago.Comment: Accepted by the Astronomical Journa

3-Year Follow-Up of the SISR (Sirolimus-Eluting Stents Versus Vascular Brachytherapy for In-Stent Restenosis) Trial

ObjectivesThe aim of this study was to evaluate long-term outcome of patients treated for in-stent restenosis of bare-metal stents (BMS).BackgroundTreatment of restenosis of BMS is characterized by high recurrence rates. Vascular brachytherapy (VBT) improved outcome although late catch-up events were documented. Drug-eluting stents tested against VBT in this setting were found superior for at least the first year; superiority at longer follow-up is uncertain.MethodsWe evaluated 3-year outcome of the multicenter SISR (Sirolimus-Eluting Stents Versus Vascular Brachytherapy for In-Stent Restenosis) trial, which randomized patients with restenosis of BMS to either a sirolimus-eluting stents (SES) or VBT.ResultsTarget vessel failure (cardiac death, infarction, or target vessel revascularization [TVR]) at 9 months as previously reported was significantly improved with SES. Kaplan-Meier analysis at 3 years documented that survival free from target lesion revascularization (TLR) and TVR continues to be significantly improved with SES: freedom from TLR 81.0% versus 71.6% (log-rank p = 0.018), and TVR 78.2% versus 68.8% (log-rank p = 0.022), SES versus VBT. At 3 years, target vessel failure and major adverse cardiac events (death, infarction, emergency coronary artery bypass grafting, or repeat TLR) remained improved with SES, but did not reach statistical significance. There was no statistically significant difference in definite or probable stent thrombosis (3.5% for SES, 2.4% for VBT; p = 0.758).ConclusionsAt 3 years of follow-up, after treatment of in-stent restenosis of BMS, patients treated with SES have improved survival free of TLR and TVR compared with patients treated with VBT. Stent thrombosis rates are not different between the 2 groups but are higher than reported in trials of treatment of de novo lesions

Multistate Switching of Spin Selectivity in Electron Transport through Light-Driven Molecular Motors

It is established that electron transmission through chiral molecules depends on the electron's spin. This phenomenon, termed the chiral‐induced spin selectivity (CISS), effect has been observed in chiral molecules, supramolecular structures, polymers, and metal‐organic films. Which spin is preferred in the transmission depends on the handedness of the system and the tunneling direction of the electrons. Molecular motors based on overcrowded alkenes show multiple inversions of helical chirality under light irradiation and thermal relaxation. The authors found here multistate switching of spin selectivity in electron transfer through first generation molecular motors based on the four accessible distinct helical configurations, measured by magnetic‐conductive atomic force microscopy. It is shown that the helical state dictates the molecular organization on the surface. The efficient spin polarization observed in the photostationary state of the right‐handed motor coupled with the modulation of spin selectivity through the controlled sequence of helical states, opens opportunities to tune spin selectivity on‐demand with high spatio‐temporal precision. An energetic analysis correlates the spin injection barrier with the extent of spin polarization

Diameter-dependent wetting of tungsten disulfide nanotubes

The simple process of a liquid wetting a solid surface is controlled by a plethora of factors—surface texture, liquid droplet size and shape, energetics of both liquid and solid surfaces, as well as their interface. Studying these events at the nanoscale provides insights into the molecular basis of wetting. Nanotube wetting studies are particularly challenging due to their unique shape and small size. Nonetheless, the success of nanotubes, particularly inorganic ones, as fillers in composite materials makes it essential to understand how common liquids wet them. Here, we present a comprehensive wetting study of individual tungsten disulfide nanotubes by water. We reveal the nature of interaction at the inert outer wall and show that remarkably high wetting forces are attained on small, open-ended nanotubes due to capillary aspiration into the hollow core. This study provides a theoretical and experimental paradigm for this intricate problem

Novel poly(3-hydroxybutyrate) nanocomposites containing WS2 inorganic nanotubes with improved thermal, mechanical and tribological properties

Poly(3-hydroxybutyrate) (PHB) nanocomposites containing environmentally-friendly tungsten disulphide inorganic nanotubes (INTeWS2) have been successfully prepared by a simple solution blending method. The dynamic and isothermal crystallization studies by differential scanning calorimetry (DSC) demonstrated that the INTeWS2 exhibits much more prominent nucleation activity on the crystallization of PHB than specific nucleating agents or other nanoscale fillers. Both crystallization rate and crystallinity significantly increase in the nanocomposites compared to neat PHB. These changes occur without modifying the crystalline structure of PHB in the nanocomposites, as shown by wide-angle X-ray diffraction (WAXS) and infrared/Raman spectroscopy. Other parameters such as the Avrami exponent, the equilibrium melting temperature, global rate constant and the fold surface free energy of PHB chains in the nanocomposites were obtained from the calorimetric data in order to determine the influence of the INTeWS2 filler. The addition of INTeWS2 remarkably influences the energetics and kinetics of nucleation and growth of PHB, reducing the fold surface free energy by up to 20%. Furthermore, these nanocomposites also show an improvement in both tribological and mechanical (hardness and modulus) properties with respect to pure PHB evidenced by friction and nanoindentation tests, which is of important potential interest for industrial and medical applications

Memory-encoding vibrations in a disconnecting air bubble

Many nonlinear processes, such as the propagation of waves over an ocean or the transmission of light pulses down an optical fibre1, are integrable in the sense that the dynamics has as many conserved quantities as there are independent variables. The result is a time evolution that retains a complete memory of the initial state. In contrast, the nonlinear dynamics near a finite-time singularity, in which physical quantities such as pressure or velocity diverge at a point in time, is believed to evolve towards a universal form, one independent of the initial state2. The break-up of a water drop in air3 or a viscous liquid inside an immiscible oil4,5 are processes that conform to this second scenario. These opposing scenarios collide in the nonlinearity produced by the formation of a finite-time singularity that is also integrable. We demonstrate here that the result is a novel dynamics with a dual character