Predicting sizes of hexagonal and gyroid metal nanostructures from liquid crystal templating

We describe a method to predict and control the lattice parameters of hexagonal and gyroid mesoporous materials formed by liquid crystal templating. In the first part, we describe a geometric model with which the lattice parameters of different liquid crystal mesophases can be predicted as a function of their water/surfactant/oil volume fractions, based on certain geometric parameters relating to the constituent surfactant molecules. We demonstrate the application of this model to the lamellar (LR), hexagonal (H1), and gyroid bicontinuous cubic (V1) mesophases formed by the binary Brij-56 (C16EO10)/water system and the ternary Brij-56/hexadecane/water system. In this way, we demonstrate predictable and independent control over the size of the cylinders (with hexadecane) and their spacing (with water). In the second part, we produce mesoporous platinum using as templates hexagonal and gyroid phases with different compositions and show that in each case the symmetry and lattice parameter of the metal nanostructure faithfully replicate those of the liquid crystal template, which is itself in agreement with the model. This demonstrates a rational control over the geometry, size, and spacing of pores in a mesoporous metal.

Non-cinema: the location of politics in film

Philosophy has repeatedly denied cinema in order to grant it artistic status. Adorno, for example, defined an ‘uncinematic’ element in the negation of movement in modern cinema, ‘which constitutes its artistic character’. Similarly, Lyotard defended an ‘acinema’, which rather than selecting and excluding movements through editing, accepts what is ‘fortuitous, dirty, confused, unclear, poorly framed, overexposed’. In his Handbook of Inaesthetics, Badiou embraces a similar idea, by describing cinema as an ‘impure circulation’ that incorporates the other arts. Resonating with Bazin and his defence of ‘impure cinema’, that is, of cinema’s interbreeding with other arts, Badiou seems to agree with him also in identifying the uncinematic as the location of the Real. This article will investigate the particular impurities of cinema that drive it beyond the specificities of the medium and into the realm of the other arts and the reality of life itself. Privileged examples will be drawn from various moments in film history and geography, starting with the analysis of two films by Jafar Panahi: This Is Not a Film (In film nist, 2011), whose anti-cinema stance in announced in its own title; and The Mirror (Aineh, 1997), another relentless exercise in self-negation. It goes on to examine Kenji Mizoguchi’s deconstruction of cinematic acting in his exploration of the geidomono genre (films about theatre actors) in The Story of the Last Chrysanthemums (Zangigku monogatari, 1939), and culminates in the conjuring of the physical experience of death through the systematic demolition of film genres in The Act of Killing (Joshua Oppenheimer et al., 2012).

Beyond difference: female participation in the Brazilian film revival of the 1990s

In this chapter, I will focus on the female participation in what became known as ‘The Retomada do Cinema Brasileiro’, or the Brazilian Film Revival, by thinking beyond differences of gender, class, age and ethnicity. I will first re-consider the Retomada phenomenon against the backdrop of its historical time, so as to evaluate whether the production boom of the period translated into a creative peak, and, if so, how much of this carried onto the present day. I will then look at the female participation in this phenomenon not just in terms of numerical growth of women film directors, admittedly impressive, but only partially reflective of the drastic changes in the modes of production and address effected by the neoliberal policies introduced in the country in the mid 1990s. I will argue that the most decisive contribution brought about by the rise of women in Brazilian filmmaking has been the spread of team work and shared authorship, as opposed to a mere aspiration to the auteur pantheon, as determined by a notoriously male-oriented tradition. Granted, films focusing on female victimisation were rife during the Retomada period and persist to this day, and they have been, and continue to be, invaluable for the understanding of women’s struggles in the country. However, rather than resorting to feminist readings of representational strategies in these films, I will draw attention to other, presentational aesthetic experiments, open to the documentary contingent and the unpredictable real, which, I argue, suspend the pedagogical character of representational narratives. In order to demonstrate that new theoretical tools are needed to understand the gender powers at play in contemporary world cinema, I will, to conclude, analyse an excerpt of the film, Delicate Crime (Crime delicado, Beto Brant, 2006), where team work comes out as a particularly effective female, and feminist, procedure.

Space, authenticity and utopia in the hip-hop teen dance film

The dance film flourished in the 2000s in the form of the hip-hop teen dance film. Such films as Save the Last Dance (Thomas Carter, 2001), Honey (Billy Woodruff, 2002) and Step Up (Anne Fletcher, 2006) drew on hip-hop’s dominance of the mainstream music industry and combined the teen film’s pre-existing social problem and musical narratives. Yet various tension were created by their interweaving of representations of post-industrial city youth with the utopian sensibilities of the classical Hollywood musical. Their narratives celebrated hip-hop performance, and depicted dance’s ability to bridge cultural boundaries and bring together couples and communities. These films used hip-hop to define space and identity yet often constructed divisions within their soundscapes, limiting hip-hop’s expressive potential. This article explores the cycle’s celebration of, yet struggle with, hip-hop through examining select films’ interactions between soundscape, narrative and form. It will engage with these films’ attempts to marry the representational, narrative and aesthetic meanings of hip-hop culture with the form and ideologies of the musical genre, particularly the tensions and continuities that arise from their engagement with the genre’s utopian qualities identified by Richard Dyer (1985). Yet whilst these films illustrate the tensions and challenges of combining hip-hop culture and the musical genre, they also demonstrate an effective integration of hip-hop soundscape and the dancing body in their depiction of dance, highlighting both form’s aesthetics of layering, rupture and flow (Rose, 1994: 22).

Shape-controlled continuous synthesis of metal nanostructures

A segmented flow-based microreactor is used for the continuous production of faceted nanocrystals. Flow segmentation is proposed as a versatile tool to manipulate the reduction kinetics and control the growth of faceted nanostructures; tuning the size and shape. Switching the gas from oxygen to carbon monoxide permits the adjustment in nanostructure growth from 1D (nanorods) to 2D (nanosheets). CO is a key factor in the formation of Pd nanosheets and Pt nanocubes; operating as a second phase, a reductant, and a capping agent. This combination confines the growth to specific structures. In addition, the segmented flow microfluidic reactor inherently has the ability to operate in a reproducible manner at elevated temperatures and pressures whilst confining potentially toxic reactants, such as CO, in nanoliter slugs. This continuous system successfully synthesised Pd nanorods with an aspect ratio of 6; thin palladium nanosheets with a thickness of 1.5 nm; and Pt nanocubes with a 5.6 nm edge length, all in a synthesis time as low as 150 s.

Controlling ivy attachment to wall surfaces by applying paints, metal meshes and sheets

Growing ivy around buildings has benefits. However, ivy potentially damages buildings which limit its use. Options for preventing ivy attachment were investigated to provide ivy management alternatives. Indoor and outdoor experiments were conducted, where metals (Cu, Zn) and anti-graffiti paints were applied to model wall panels. Metal treatments, in both indoor and outdoor experiments, fully prevented ivy attachment. For Hedera helix, silane-based anti-graffiti paint prevented attachment in the laboratory and required under half the peak detachment force necessary to detach the control in the outdoor experiment. In conclusion, metals and silane-based paint are management possibilities for ivy attachment around buildings.

Correlation between vertical misfits and stresses transmitted to implants from metal frameworks

An inappropriate prosthetic fit could cause stress over the interface implant/bone. The objective of this study was to compare stresses transmitted to implants from frameworks cast using different materials and to investigate a possible correlation between vertical misfits and these stresses. Fifteen one-piece cast frameworks simulating bars for fixed prosthesis in a model with five implants were fabricated and arranged into three different groups according to the material used for casting: CP Ti (commercially pure titanium), Co-Cr (cobalt-chromium) or Ni-Cr-Ti (nickel-chromium-titanium) alloys. Each framework was installed over the metal model with all screws tightened to a 10 N cm torque and then, vertical misfits were measured using an optical microscope. The stresses transmitted to implants were measured using quantitative photoelastic analysis in values of maximum shear stress (T), when each framework was tightened to the photoelastic model to a 10 N cm standardized torque. Stress data were statistically analyzed using one-way ANOVA and Tukey`s test and correlation tests were performed using Pearson`s rank correlation (alpha = 0.05). Mean and standard deviation values of vertical misfit are presented for CP Ti (22.40 +/- 9.05 mu m), Co-Cr (66.41 +/- 35.47 mu m) and Ni-Cr-Ti (32.20 +/- 24.47 mu m). Stresses generated by Co-Cr alloy (tau = 7.70 +/- 2.16 kPa) were significantly higher than those generated by CP Ti (tau = 5.86 +/- 1.55 kPa, p = 0.018) and Ni-Cr-Ti alloy (tau =5.74 +/- 3.05 kPa, p = 0.011), which were similar (p = 0.982). Correlations between vertical misfits and stresses around the implants were not significant as for any evaluated materials. (C) 2011 Elsevier Ltd. All rights reserved.

Corrosion behavior of pure titanium in artificial saliva solution

The biocompatibility of commercially pure (cp) titanium stems from its chemical stability within an organism, due to a fine film of impermeable titanium oxide covering the metal surface, which guarantees its resistance to corrosion. Despite its biocompatible characteristic, this material does not promote the formation of a hydroxyapatite layer, therefore, many research groups have sought to alter the material`s surface, introducing modifications that might influence corrosion resistance. The electrochemical behavior of cp Ti, with hydroxyapatite coating and without hydroxyapatite coating, commonly used in implant materials, was investigated using an artificial saliva solution at 25 degrees C and pH=7.4. In the conditions of the study it was observed that the hydroxyapatite layer influences the properties of corrosion resistance. This study of the behavior of cp Ti with and without hydroxyapatite coating, in naturally aerated artificial saliva solution at 25 degrees C, was based on open circuit potential measurements and potentiodynamic polarization curves. At approximately 1x10(-6) A/cm(2) the potential for cp Ti with and without hydroxyapatite coating begins to increase at a faster rate, but at -74mV (SCE) for coated cp Ti and at 180mV (SCE) for uncoated cp Ti the increase in potential begins to slow. This behavior, characterized by a partial stabilization of current density, indicates that in those potential ranges a protective passive film is formed.

Development and Evaluation of a Novel pH Indicator Biodegradable Film Based on Cassava Starch

A pH indicator film based on cassava starch plasticized with sucrose and inverted sugar and incorporated with grape and spinach extracts as pH indicator sources (anthocyanin and chlorophyll) has been developed, and its packaging properties have been assessed. A second-order central composite design (2(2)) with three central points and four star points was used to evaluate the mechanical properties (tensile strength, tensile strength at break, and elongation at break percentage), moisture barrier, and microstructure of the films, and its potential as a pH indicator packaging. The films were prepared by the casting technique and conditioned under controlled conditions (75% relative humidity and 23 degrees C), at least 4 days before the analyses. The materials were exposed to different pH solutions (0, 2, 7, 10, and 14) and their color parameters (L*, a*, b*, and haze) were measured by transmittance. Grape and spinach extracts have affected the material characterization. Film properties (mechanical properties and moisture barrier) were strongly influenced by extract concentration presenting lower results than for the control. Films containing a higher concentration of grape extract presented a greater color change at different pH`s suggesting that anthocyanins are more effective as pH indicators than chlorophyll or the mixture of both extracts. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 120: 1069-1079,2011

Film forming solutions based on gelatin and poly(vinyl alcohol) blends: Thermal and rheological characterizations

The objective of this work was to study the theological and thermal properties of film forming solutions (FFS) based on blends of gelatin and poly(vinyl alcohol) (PVA). The effect of the PVA concentration and plasticizer presence on the flow behavior, and viscoelastic and thermal properties of FFS was studied by steady-shear flow and oscillatory experiments, and also, by microcalorimetry. The FB presented Newtonian behavior at 30 degrees C, and the viscosity was not affected neither by the PVA concentration nor by the plasticizer. All FFS presented a phase transition during tests applying temperature scanning. It was verified that the PVA affected the viscoelastic properties of FFS by dilution of gelatin. This behavior was confirmed by microcalorimetric analysis. The behaviors of the storage (G`) and loss (G ``) moduli as a function of frequency of FFS obtained at 5 degrees C were typical of physical gels; with the G` higher than the G ``. The strength of the gels was affected by the PVA concentration. (C) 2009 Elsevier Ltd. All rights reserved.

Characterization of Metal and Trace Element Contents of Particulate Matter (PM10) Emitted by Vehicles Running on Brazilian FuelsHydrated Ethanol and Gasoline with 22% of Anhydrous Ethanol

Emission of fine particles by mobile sources has been a matter of great concern due to its potential risk both to human health and the environment. Although there is no evidence that one sole component may be responsible for the adverse health outcomes, it is postulated that the metal particle content is one of the most important factors, mainly in relation to oxidative stress. Data concerning the amount and type of metal particles emitted by automotive vehicles using Brazilian fuels are limited. The aim of this study was to identify inhalable particles (PM10) and their trace metal content in two light-duty vehicles where one was fueled with ethanol while the other was fueled with gasoline mixed with 22% of anhydrous ethanol (gasohol); these engines were tested on a chassis dynamometer. The elementary composition of the samples was evaluated by the particle-induced x-ray emission technique. The experiment showed that total emission factors ranged from 2.5 to 11.8 mg/km in the gasohol vehicle, and from 1.2 to 3 mg/km in the ethanol vehicle. The majority of particles emitted were in the fine fraction (PM2.5), in which Al, Si, Ca, and Fe corresponded to 80% of the total weight. PM10 emissions from the ethanol vehicle were about threefold lower than those of gasohol. The elevated amount of fine particulate matter is an aggravating factor, considering that these particles, and consequently associated metals, readily penetrate deeply into the respiratory tract, producing damage to lungs and other tissues.

The old metal-poor open cluster ESO 92-SC05: accreted from a dwarf galaxy ?

The study of old open clusters outside the solar circle can bring constraints on formation scenarios of the outer disc. In particular, accretion of dwarf galaxies has been proposed as a likely mechanism in the area. We use BVI photometry for determining fundamental parameters of the faint open cluster ESO 92-SC05. Colour-magnitude diagrams are compared with Padova isochrones, in order to derive age, reddening and distance. We derive a reddening E(B - V) = 0.17, and an old age of similar to 6.0 Gyr. It is one of the rare open clusters known to be older than 5 Gyr. A metallicity of Z similar to 0.004 or [M/H] similar to -0.7 is found. The rather low metallicity suggests that this cluster might be the result of an accretion episode of a dwarf galaxy.