Here I am yet cannot hold this visible shape:The Music of Gender in Shakespeare’s Twelfth Night

Music has always been used as an important dramaturgical strategy in Western theatre to create a holistic theatrical experience. In Shakespeare’s plays, music was employed as a unique dramaturgical device for various purposes. Twelfth Night distinguishes itself from among the many plays that employ music because it begins, ends and progresses with music. Music pervades Twelfth Night and is tightly interwoven into the thematic concerns of the play such as love and gender. Because of music’s elusive nature and the difficulty of discussing a musical aesthetics, Shakespearean music critics have approached music in the play as a theme or an idea. This paper hopes to develop upon older scholarship by introducing an alternate framework of considering music’s musicality through a musicological analysis of the songs in Twelfth Night. In so doing, the paper hopes to show how and why music can modulate our responses to the play and in particular, to the theme of gender, a problematic issue that produces the elusive and darker nature of this festive comedy.

Mundane Mobilities in ‘Post-Socialist’ Sofia: Making Urban Borders Visible

This article reflects on an on-going research project which aims to expand the understanding of the production and transformation of urban borders in the Eastern European cities of the ex ‘communist bloc’, starting from the case of Sofia. It explores the proposition that there has been a prolific process of wall making in this city associated with ‘vanishing public spaces’, ‘rescaling of enclosure’, and ‘corrosion of the collective urban realm’ (Hirt, 2012). The paper seeks to understand the social and political effects of this process by delving into the sensorial, emotional and embodied experiences associated with the mundane mobilities of urban residents. Using participants’ self-directed photography and videos from ‘walk-along’ interviews it explores the ways in which borders are made visible and are produced, challenged or resisted through mobility, and delves into the associated senses of deepening social and spatial differentiation in the city.

Development of a doped titania immobilised thin film multi tubular photoreactor

This paper describes a novel doped titania immobilised thin film multi tubular photoreactor which has been developed for use with liquid, vapour or gas phase media. In designing photocatalytic reactors measuring active surface area of photocatalyst within the unit is one of the critical design parameters. This dictate greatly limits the applicability of any semi-conductor photocatalyst in industrial applications, as a large surface area equates to a powder catalyst. This demonstration of a thin film coating, doped with a rare earth element, novel photoreactor design produces a photocatalytic degradation of a model pollutant (methyl orange) which displayed a comparable degradation achieved with P25 TiO2. The use of lanthanide doping is reported here in the titania sol gel as it is thought to increase the electron hole separation therefore widening the potential useful wavelengths within the electromagnetic spectrum. Increasing doping from 0.5% to 1.0% increased photocatalytic degradation by ∼17% under visible irradiation. A linear relationship has been seen between increasing reactor volume and degradation which would not normally be observed in a typical suspended reactor system. © 2012 Elsevier B.V.

Photo-dynamic biocidal action of methylene blue and hydrogen peroxide on the cyanobacterium Synechococcus leopoliensis under visible light irradiation

Biofilm growth on stone surfaces is a significant contributing factor to stone biodeterioration. Current market based biocides are hazardous to the environment and to public health. We have investigated the photo-dynamic effect of methylene blue (MB) in the presence of hydrogen peroxide (H₂O₂) on the destruction of the cyanobacterium Synechococcus leopoliensis (S. leopoliensis) under irradiation with visible light. Data presented in this paper illustrate that illumination of S. leopoliensis in the presence of a photosensitiser (MB) and H₂O₂ results in the decomposition of both the cyanobacterium and the photosensitiser. The presence of MB and H₂O₂ affects the viability of the photosensitiser and the cyanobacterium with the fluorescence of both decreasing by 80% over the irradiation time investigated. The photo-dynamic effect was observed under aerobic and anaerobic conditions indicating that oxygen was not necessary for the process. This novel combination could be effective for the remediation of biofilm colonised stone surfaces

Photosensitized destruction of Chlorella vulgaris by methylene blue or nuclear fast red combined with hydrogen peroxide under visible light irradiation

A considerable number of investigations have started to elucidate the essential roles biological agents play in the biodeterioration of stone. Chemical biocides are becoming increasingly banned because of the environmental and health hazards associated with these toxic substances. The present study reports the photodynamic effect of Methylene Blue (MB) and Nuclear Fast Red (NFR) in the presence of hydrogen peroxide (H₂O₂) on the destruction of the algae Chlorella vulgaris (C. vulgaris) under irradiation with visible light. Illumination of C. vulgaris in the presence of MB or NFR combined with H₂O₂ results in the decomposition of both the algal species and the photosensitizer. The photodynamic effect was investigated under aerobic and anaerobic conditions. Differences in mechanism type are reported and are dependent on both the presence and the absence of oxygen. The behavior of each photosensitizer leads to a Type II mechanism and a Type I/Type II combination for MB and NFR, respectively, being concluded. This novel combination could be effective for the remediation of biofilm-colonized stone surfaces.

Application of laser radiation for the treatment of waste materials using a photocatalyst

One effective approach is to destroy industrial waste and pollution is the use of a semiconductor photocatalysis system. To date such, photocatalysis systems have employed conventional linear light sources. Initial results from a study of a photocatalysis system incorporating a tripled Nd:YAG laser are reported. The laser light not only played a roll as a light source for activating the photocatalyst(TiO₂), but also destroyed the organic species directly via a photochemical process. The reaction intermediates and changes in their concentrations are monitored using HPLC. The relationship between the power of laser and kinetics of photoreaction are discussed.

The application of surface second harmonic sensor to probe laser induced modification of titanium dioxide

The effects of high power pulsed laser light on a TiO2 photocatalyst have been investigated using a surface second harmonic generation (SSHG) sensor. When TiO2 is irradiated with a laser at 355mm a visible change in colour from white to dark blue crystals was observed. X-ray diffraction studies indicate that the crystal structure of the TiO2 developed a more rutile form following laser exposure.

Visible-Wavelength Survey of Jupiter-Family Cometary Nuclei as Part of SEPPCoN

We present observations of a statistically-significant number of Jupiter-family cometary nuclei as part of SEPPCoN (Survey of the Ensemble Physical Properties of Cometary Nuclei). We present preliminary results on distributions of albedos and shapes.

Visible-wavelength Observations of Jupiter-family Comet Nuclei as Part of Seppcon.

We present the latest analysis and results from SEPPCoN (Survey of Ensemble Physical Properties of Cometary Nuclei). This on-going survey involves studying 100 JFCs - about 25% of the known population - at both mid-infrared and visible wave-lengths to constrain the distributions of sizes, shapes, spins, and albedos of this population. Having earlier reported results from measuring thermal emissions of our sample nuclei [1,2,3,4], we report here progress on the visible-wavelength observations that we have obtained at many ground-based facilities in Chile, Spain, and the United States. To date we have attempted observations of 91% of our sample of 100 JFCs, and at least 64 of those were successfully detected. In most cases the comets were at heliocentric distances between 3.0 and 6.5 AU so as to decrease the odds of a comet having a coma. Of the 64 detected comets, 48 were apparently bare, having no extended emission. Our datasets are further augmented by archival data and photometry from the NEAT program [5]. An important goal of SEPPCoN is to accumulate a large comprehensive set of high quality physical data on cometary nuclei in order to make accurate statistical comparisons with other minor-body populations such as Trojans, Centaurs, and Kuiper-belt objects. Information on the size, shape, spin-rate, albedo and color distributions is critical for understanding their origins and evolutionary processes affecting them.

Unidirectional suppression of hydrogen oxidation on oxidized platinum clusters

Solar-driven water splitting to produce hydrogen may be an ideal solution for global energy and environment issues. Among the various photocatalytic systems, platinum has been widely used to co-catalyse the reduction of protons in water for hydrogen evolution. However, the undesirable hydrogen oxidation reaction can also be readily catalysed by metallic platinum, which limits the solar energy conversion efficiency in artificial photosynthesis. Here we report that the unidirectional suppression of hydrogen oxidation in photocatalytic water splitting can be fulfilled by controlling the valence state of platinum; this platinum-based cocatalyst in a higher oxidation state can act as an efficient hydrogen evolution site while suppressing the undesirable hydrogen back-oxidation. The findings in this work may pave the way for developing other high-efficientcy platinum-based catalysts for photocatalysis, photoelectrochemistry, fuel cells and water-gas shift reactions.

Action Spectra of P25 TiO2 and a visible light absorbing, carbon-modified titania in the photocatalytic degradation of stearic acid

The photonic efficiencies of films of Evonik (formerly Degussa) P25 TiO2 and carbon-modified TiO2 Kronos VLP 7000 samples are reported as a function of excitation wavelength (300–430 nm; FWHM ∼ 7.5 nm), i.e. the action spectra, for the degradation of stearic acid, a model organic for the photocatalytic destruction of solid surface organic pollutants. For each of these semiconductor photocatalysts, at 365 nm (FWHM = 18 nm), the dependence of the rate of degradation of stearic acid, upon the irradiance, I, is determined and the rate is found to be proportional to I0.65 and I0.82 for P25 and Kronos titania, respectively. Assuming this relationship holds at all wavelengths, the action spectra for two different semiconductor photocatalysts is modified by plotting, (RSA (rate of stearic acid destruction, units: molecules cm−2 s−1)/Iθ) vs. wavelength of excitation (λexcit), and both differ noticeably from those of the original (unmodified) action spectra, which are plots of (RSA/I = photonic efficiency, ξ) vs. λexcit. The shape of the modified action spectrum for P25 TiO2 is consistent with that reported by others for other organic mineralisation reactions and correlates well with diffuse reflectance data for P25 TiO2 (Kubelka–Munk plot), although there is some evidence that the active phase, in the photodegradation of stearic acid, is the anatase form present in P25. The unmodified and modified action spectra of the beige Kronos VLP 7000 TiO2 compound exhibits little or no activity in the visible i.e. (λexcit > 400 nm) and a peak at 350 nm. The Kronos powder contains a yellow/brown conjugated, extractable, organic sensitiser which has been identified by others as the species responsible for its reported photocatalytic visible light activity. But, irradiation of the Kronos powder film, with and without a stearic acid coating, in air, using UVA or visible light, bleaches rapidly (<60 min) most, if not all, of the little colour exhibited by the original Kronos powder. The photobleached form of the Kronos has a similar action spectrum to that of the unbleached form, which, in turn, appears very similar to that of P25 titania, at wavelengths >350 nm. It is proposed that the difference between the Kronos and P25 powder films at wavelengths <350 nm is due to a photodegradation-resistant, previously unidentified (but extractable using MeCN) UV-absorbing organic species in the former which screens the titania particles at these lower wavelengths. The implications of these observations are discussed briefly.

Correlation between ΔAbs, ΔRGB (red) and stearic acid destruction rates using commercial self-cleaning glass as the photocatalyst

A resazurin (Rz) based photocatalyst indicator ink is used to test the activity of a commercial self-cleaning glass, using UV–vis spectroscopy and digital photography to monitor the photocatalyst-driven change in colour of the ink. UV–vis spectroscopy allows the change in film absorbance, ΔAbs, to be monitored as a function of irradiation time, whereas digital photography is used to monitor the concomitant change in the red component of the RGB values, i.e. ΔRGB (red). Initial work reveals the variation in ΔAbst and ΔRGB (red)t as a function of irradiation time, t, are linearly correlated. The rates of change of these parameters are also linearly correlated to the rates of oxidative destruction of stearic acid on self-cleaning glass under different irradiances. This work demonstrates that a measure of photocatalyst activity of self-cleaning glass, i.e. the time taken to change the colour of an Rz photocatalyst indicator ink, can be obtained using inexpensive digital photography, as alternative to more expensive lab-based techniques, such as UV–vis spectrophotometry.

Orange Zinc Germanate with Metallic Ge-Ge Bonds as a Chromophore-Like Center for Visible-Light-Driven Water Splitting

The efficiency of solar-energy-conversion devices depends on the absorption region and intensity of the photon collectors. Organic chromophores, which have been widely stabilized on inorganic semiconductors for light trapping, are limited by the interface between the chromophore and semiconductor. Herein we report a novel orange zinc germanate (Zn-Ge-O) with a chromophore-like structure, by which the absorption region can be dramatically expanded. Structural characterizations and theoretical calculations together reveal that the origin of visible-light response can be attributed to the unusual metallic Ge-Ge bonds which act in a similar way to organic chromophores. Benefiting from the enhanced light harvest, the orange Zn-Ge-O demonstrates superior capacity for solar-driven hydrogen production.