Ore controls and formation of the ore-bearing structures in the Idarado mines, San Miguel and Ouray Counties, Colorado

Two major ore-bearing veins were studied on two levels in the Idarado mine, on the northwestern flank of the San Juan Mountains of southwestern Colorado. The Argentine vein, striking N. 10°-20° W. and dipping 75°-85° W., and the Cross vein, striking N. 45°-50° W. and dipping 50° W. represent the two systems to which all productive veins of the mine belong. Although not formed simultaneously, all veins represent mid-Tertiary mineralization associated with volcanism that formed the San Juan Mountains. Vein minerals are galena, sphalerite, chalcopyrite, silver (probably as sulfides), and gold in a gangue of pyrite, quartz, calcite and epidote. Geological mapping, field investigations, and mineragraphical and petrological studies were used in determining the ore controls and the sequence of formation and mineralization of the ore-bearing structures. Five stages in this sequence can be detected. Although the primary mechanism of vein formation was simple fissure-filling, differences were detected in ore controls in the two structures. These differences are conspicuous where typical fissure-filling veins have been enlarged by replacement of favorable wall rock. Favorable wall rock consisted of relatively permeable conglomeratic beds with a calcitic or dolomitic matrix. In the older Argentine vein, this matrix was epidotized during intrusion of a pre-ore andesite dike. During ore mineralization, the epidotized material reacted similarly to the unchanged carbonate-bearing matrix of the younger Cross vein. In both veins, metasomatism was most extensive where fractures, joints, or original permeability are present in combination with the chemical wall-rock control

Innovative semi-transparent nanocomposite films presenting photo-switchable behavior and leading to a reduction of the risk of infection under sunlight

Novel sputtered polyethylene-TiO2 (PE-TiO2) thin films induce fast bacterial inactivation with concomitant photo-switchable hydrophobic to hydrophilic transition under light. RF-plasma pretreatments allowed an increased TiO2 loading on PE, favorably affecting the photocatalyst performance. ATR-FTIR spectroscopy shows that the increase in the cell lipid-layer fluidity leads to cell wall scission/bacterial inactivation

Accelerated self-cleaning by Cu promoted semiconductor binary-oxides under low intensity sunlight irradiation

Uniform adhesive TiO2–ZrO2 films co-sputtered on polyester (PES) under low intensity sunlight irradiation discolored methylene blue (MB) within 120 min. The discoloration kinetics was seen to be accelerated by a factor four by TiO2–ZrO2–Cu containing ∼0.01% Cu, as determined by X-ray fluorescence (XRF). TiO2–ZrO2–Cu also increased also accelerated by a factor the discoloration of MB compared to TiO2/Cu(PES). MB discoloration was also monitored under visible light in the solar cavity by using a 400 nm cutoff filter. Photocatalyst surfaces were characterized by spectroscopic methods showing the film optical absorption and by X-ray photoelectron spectroscopy (XPS), the surface atomic percentage concentration up to 120 nm (∼600 layers). The band-gaps of TiO2–ZrO2 and TiO2–ZrO2–Cu were estimated for films co-sputtered for different times. By Fourier transform attenuated infrared spectroscopy (ATR-FTIR), the systematic shift of the predominating νs(CH2) vibration-rotational MB bands was monitored up to complete MB discoloration under low intensity solar simulated light. Evidence is presented for the OHradical dot generation by TiO2–ZrO2–Cu participating in the self-cleaning mechanism. The photo-induced interfacial charge transfer (IFCT) on the TiO2–ZrO2–Cu is discussed in terms of the electronic band positions of the binary oxides and Cu intra-gap states. This study presents the first evidence for a Cu-promoted composed of two binary oxide semiconductors accelerating the self-cleaning performance

Cavity-enhanced superconducting single-photon detectors on GaAs substrate

Nanowire superconducting single photon detectors (SSPDs) are unique detectors for many applications in quantum information and communications technology, owing to their ultrafast photoresponse, low dark count rate and low timing jitter. However, they have limited detection efficiency due to small optical absorption in ultrathin wires. A promising approach to increase the photon absorption in SSPDs, is integrating them with advanced optical structures. We demonstrate the successful integration of SSPDs with optical microcavities based on GaAs/AlAs Bragg mirrors. Characterization of these devices reveals clear cavity enhancement of the detection efficiency, resulting in a peak value of18% at 2=l300nm and T=4.2

Design, testing and characterization of innovative TiN–TiO2 surfaces inactivating bacteria under low intensity visible light

Ti was sputtered in a plasma chamber under a N2 atmosphere, depositing TiN films on polyester fibers. These films show a significant adsorption in the visible spectral region. A TiN layer 50 nm thick sputtered for 3 min under low intensity/actinic visible light led to the fastest bacterial inactivation (120 min). These innovative TiN nanoparticulate films were characterized by XPS, DRS and TEM

Thermochromic films of VO 2 :W for smart solar energy applications

Overheating is a problem with the use of active/passive solar energy in thermal solar energy systems. A solution to these problems might be provided by a thermochromic material such as vanadium dioxide. In order to simulate the optical behaviour of multilayered coatings, knowledge on its optical properties is necessary. We determined point-by-point the dielectric function for VO2:W by ellipsometry. For validation, the solar spectra were measured by spectrophotometry. Such data have been compared with the computer simulations based on the determined optical properties. Finally, we collect optical data by infrared-imaging to detect the switch in emissivity of VO2:W at around 45°C

Coupling of narrow and wide band-gap semiconductors on uniform films active in bacterial disinfection under low intensity visible light: Implications of the interfacial charge transfer (IFCT)

This study reports the design, preparation, testing and surface characterization of uniform films deposited by sputtering Ag and Ta on non-heat resistant polyester to evaluate the Escherichia coil inactivation by TaON, TaN/Ag, Ag and TaON/Ag polyester. Co-sputtering for 120 s Ta and Ag in the presence of N-2 and O-2 led to the faster E. coil inactivation by a TaON/Ag sample within similar to 40 min under visible light irradiation. The deconvolution of TaON/Ag peaks obtained by X-ray photoelectron spectroscopy (XPS) allowed the assignment of the Ta2O5 and Ag-species. The shifts observed for the XPS peaks have been assigned to Ago to Ag2O and Ag-0, and are a function of the applied sputtering times. The mechanism of interfacial charge transfer (IFCT) from the Ag2O conduction band (cb) to the lower laying Ta2O5 (cb) is discussed suggesting a reaction mechanism. The optical absorption of the TaON and TaON/Ag samples found by diffuse reflectance spectroscopy (DRS) correlated well with the kinetics of E. coli inactivation. The TaON/Ag sample microstructure was characterized by contact angle (CA) and by atomic force microscopy (AFM). Self-cleaning of the TaON/Ag polyester after each disinfection cycle enabled repetitive E. coil inactivation. (C) 2013 Elsevier B.V. All rights reserved

Duality in the Escherichia coli and methicillin resistant Staphylococcus aureus reduction mechanism under actinic light on innovative co-sputtered surfaces

The kinetics of bacterial reduction of Staphylococcus aureus (MRSA) on co-sputtered TiO2/Cu-polyester (TiO2/Cu-PES) was found to be little dependent on the applied light dose. But in the case of Escherichia coil, the bacterial reduction kinetics was observed to be strongly dependent on the applied light dose. The reasons for the different effect of the applied light dose on the bacterial reduction are discussed. Mechanistic considerations are suggested to account for this observation.TiO2/Cu-PES obtained by direct current magnetron co-sputtering and the bacterial reduction features compared to PES sputtered individually by TiO2 and Cu. This study presents the first evidence for the stabilizing effect of TiO2 on the amounts of the Cu released during bacterial inactivation by co-sputtered surfaces compared to sequential sputtering of Ti and/or Cu on PES. The release of Cu-monitored in the ppb range by inductively coupled plasma-mass spectrometry (ICP-MS) is indicative of an oligodynamic effect leading to bacterial reduction. The bacterial reduction of MRSA ATCC 43300 on co-sputtered TiO2/Cu led to a 5 log(10) (99.999%) reduction within 120 min in the dark and 60 min under low intensity actinic light. Diffuse reflectance spectroscopy (DRS), transmission electron microscopy (TEM) and X-ray fluorescence (XRF) describe the TiO2/Cu surfaces investigated in this study. (C) 2015 Elsevier B.V. All rights reserved

ZrNO-Ag co-sputtered surfaces leading to E. coli inactivation under actinic light: Evidence for the oligodynamic effect

This study reports visible light sensitive ZrNO and ZrNO-Ag polyester samples prepared by sputtering in an Ar/N-2/O-2 atmosphere leading to Escherichia coil bacterial inactivation. The bacterial inactivation by ZrNO avoids the increasing environmental concern involving the fate of Ag-leaching of many disinfectants. The simultaneous co-sputtering of ZrNO and Ag2O enhanced the E. coli bacterial inactivation kinetics compared to the sequential sputtering of ZrNO and Ag. A reaction mechanism is suggested triggered by photoinduced interfacial charge transfer (IFCT) suggesting electron injection form the Ag2Ocb, to the ZrO2cb. The sizes of the ZrO2 and Ag nanoparticles in the co-sputtered ZrNO-Ag were 80-130 nm and 8-15 nm respectively as determined by high angular annular dark field (HAADF) microscopy. Evidence is presented by X-ray photoelectron spectroscopy (XPS) for the self-cleaning of the photocatalysts after bacterial inactivation. This enabled a stable catalyst reuse. The XPS experimental spectra of ZrNO and ZrNO-Ag were deconvoluted into their ZrN, ZrNO and ZrO2 components. The amounts of Ag-ions released during bacterial inactivation were <5 ppb/cm(2) and well below the Ag cytotoxic levels. Since no cytotoxicity was introduced during the bacterial inactivation process, the ZrNO-Ag disinfection proceeds through an oligodynamic effect. (C) 2013 Elsevier B.V. All rights reserved

Waveguide single-photon detectors for integrated quantum photonic circuits

The generation, manipulation and detection of quantum bits (qubits) encoded on single photons is at the heart of quantum communication and optical quantum information processing. The combination of single-photon sources, passive optical circuits and single-photon detectors enables quantum repeaters and qubit amplifiers, and also forms the basis of all-optical quantum gates and of linear-optics quantum computing. However, the monolithic integration of sources, waveguides and detectors on the same chip, as needed for scaling to meaningful number of qubits, is very challenging, and previous work on quantum photonic circuits has used external sources and detectors. Here we propose an approach to a fully-integrated quantum photonic circuit on a semiconductor chip, and demonstrate a key component of such circuit, a waveguide single-photon detector. Our detectors, based on superconducting nanowires on GaAs ridge waveguides, provide high efficiency (20%) at telecom wavelengths, high timing accuracy (60 ps), response time in the ns range, and are fully compatible with the integration of single-photon sources, passive networks and modulators.Comment: 11 pages, 4 figure