Self-organized Au nanoarrays on vertical graphenes : an advanced three-dimensional sensing platform

A three-dimensional surface enhanced Raman scattering (SERS)/plasmonic sensing platform based on plasma-enabled, catalyst-free, few-layer vertical graphenes decorated with self-organized Au nanoparticle arrays is demonstrated. This platform is viable for multiple species detection and overcomes several limitations of two-dimensional sensors.

Demonstration of nonlinear absorption in Au semi-continuous film by electrical measurement

We have demonstrated the nonlinear absorption at 532 nm wavelength in an Au semi-continuous film (SF) resulting from smearing of the Fermi distribution and diffusion of conduction electrons into the substrate. The Au SF was irradiated by a pulsed laser with 8 ns pulse width at 532 nm in near resonance with the interband transition of the Au. We determined the temperature increase in the SF for different intensities by electrical measurement. We calculated the temperature increase by using a 1D heat transport equation; comparing the results of the calculation with measured values for the temperature increase, revealed the nonlinear absorption in the Au SF. We employed this deviation from linear behaviour to determine the nonlinear absorption coefficient.

The Hofstedian approach : suggestions for a conceptual development of comparative journalism studies

In recent years there has been a burgeoning amount of research comparing journalistic practices in a wide range of countries around the world. Much of this literature has tended to focus on identifying what the similarities and differences between these different journalistic cultures are. Most importantly, research has focused on answering the question of whether, particularly in the age of globalisation, ‘a journalistic culture’ may exist. While there has been some evidence that there may indeed be a convergence of journalistic cultures, studies have at the same time found that important differences still persist. However, most of the literature has so far still tended to concentrate purely on the differences and similarities, without examining in detail why these exist. In this context, the author argues that employing a cross-cultural approach rooted in anthropology can at least partially trace the development of particularly the differences by linking them to the wider concept of cultural differences between countries. Specifically the paper here evaluates the usefulness of applying the value systems appraoch, as designed by Dutch anthropologist Geert Hofstede, to journalism research. By examining some of the few studies that have employed Hofstede’s approach, the paper argues that value systems can provide a classification on a conceptual level for investigating how journalism is practiced around the world. In the light of complaints in the Asia-Pacific region that the imported Western models of journalism are not in line with cultural values, this approach can also provide some basis from which to develop future approaches to journalism education.

Catalytic role of pre-adsorbed CO in platinum-based catalysts : the reduction of SO 2 by CO on Pt l Au m (CO) n

Using density functional theory, we have investigated the catalytic properties of bimetallic complex catalysts PtlAum(CO)n (l + m = 2, n = 1–3) in the reduction of SO2 by CO. Due to the strong coupling between the C-2p and metal 5d orbitals, pre-adsorption of CO molecules on the PtlAum is found to be very effective in not only reducing the activation energy, but also preventing poisoning by sulfur. As result of the coupling, the metal 5d band is broadened and down-shifted, and charge is transferred from the CO molecules to the PtlAum. As SO2 is adsorbed on the catalyst, partial charge moves to the anti-σ bonding orbitals between S and O in SO2, weakening the S–O bond strength. This effect is enhanced by pre-adsorbing up to three CO molecules, therefore the S–O bonds become vulnerable. Our results revealed the mechanism of the excellent catalytic properties of the bimetallic complex catalysts.

Catalytic reduction of SO2 by CO over Pt l Au m (CO) n: a first-principles investigation

The catalytic activities, to the reduction of SO2 by CO, of clusters PtlAum (l + m = 2) with or without preadsorbing CO molecules are investigated using first-principles density functional theory. We find that the PtAu(CO)n (n = 1–3) clusters show more excellent catalytic properties than either pure metallic catalysts. Preadsorption of CO to the catalysts could effectively avoid platinum-based catalyst sulfur poisoning; as more CO molecules preadsorbed to the catalysts, the energy barriers for the carbonyl sulfide (COS) molecule’s desorption from the catalyst are remarkably decreased. We propose an ideal catalytic cycle to simultaneously get rid of SO2 and CO over the catalysts PtAu(CO)3.

Weaknesses in the initialisation process of the Common Scrambling Algorithm Stream Cipher

The Common Scrambling Algorithm Stream Cipher (CSASC) is a shift register based stream cipher designed to encrypt digital video broadcast. CSA-SC produces a pseudo-random binary sequence that is used to mask the contents of the transmission. In this paper, we analyse the initialisation process of the CSA-SC keystream generator and demonstrate weaknesses which lead to state convergence, slid pairs and shifted keystreams. As a result, the cipher may be vulnerable to distinguishing attacks, time-memory-data trade-off attacks or slide attacks.

Computational strategies for surface fitting using thin plate spline finite element methods

Thin plate spline finite element methods are used to fit a surface to an irregularly scattered dataset [S. Roberts, M. Hegland, and I. Altas. Approximation of a Thin Plate Spline Smoother using Continuous Piecewise Polynomial Functions. SIAM, 1:208--234, 2003]. The computational bottleneck for this algorithm is the solution of large, ill-conditioned systems of linear equations at each step of a generalised cross validation algorithm. Preconditioning techniques are investigated to accelerate the convergence of the solution of these systems using Krylov subspace methods. The preconditioners under consideration are block diagonal, block triangular and constraint preconditioners [M. Benzi, G. H. Golub, and J. Liesen. Numerical solution of saddle point problems. Acta Numer., 14:1--137, 2005]. The effectiveness of each of these preconditioners is examined on a sample dataset taken from a known surface. From our numerical investigation, constraint preconditioners appear to provide improved convergence for this surface fitting problem compared to block preconditioners.

Antisocial behaviour orders : Unanticipated directions in social network site development

Abstract: Social network technologies, as we know them today have become a popular feature of everyday life for many people. As their name suggests, their underlying premise is to enable people to connect with each other for a variety of purposes. These purposes however, are generally thought of in a positive fashion. Based on a multi-method study of two online environments, Habbo Hotel and Second Life, which incorporate social networking functionality, we she light on forms of what can be conceptualized as antisocial behaviours and the rationales for these. Such behaviours included: scamming, racist/homophobic attacks, sim attacks, avatar attacks, non-conformance to contextual norms, counterfeiting and unneighbourly behaviour. The rationales for sub behaviours included: profit, fun, status building, network disruption, accidental acts and prejudice. Through our analysis we are able to comment upon the difficulties of defining antisocial behaviour in such environments, particularly when such environments are subject to interpretation vis their use and expected norms. We also point to the problems we face in conducting our public and private lives given the role ICTs are playing in the convergence of these two spaces and also the convergence of ICTs themselves.

Convergent Media Policy

This chapter considers the implications of convergence for media policy from three perspectives. First, it discusses what have been the traditional concerns of media policy, and the challenges it faces, from the perspectives of public interest theories, economic capture theories, and capitalist state theories. Second, it looks at what media convergence involves, and some of the dilemmas arising from convergent media policy including: (1) determining who is a media company; (2) regulatory parity between ‘old’ and ‘new’ media; (3) treatment of similar media content across different platforms; (4) distinguishing ‘big media’ from user-created content; and (5) maintaining a distinction between media regulation and censorship of personal communication. Finally, it discusses attempts to reform media policy in light of these changes, including Australian media policy reports from 2011-12 including the Convergence Review, the Finkelstein Review of News Media, and the Australian Law Reform Commission’s National Classification Scheme Review. It concludes by arguing that ‘public interest’ approaches to media policy continue to have validity, even as they grapple with the complex question of how to understand the concept of influence in a convergent media environment.

Adaptive estimation of HMM transition probabilities

This paper presents new schemes for recursive estimation of the state transition probabilities for hidden Markov models (HMM's) via extended least squares (ELS) and recursive state prediction error (RSPE) methods. Local convergence analysis for the proposed RSPE algorithm is shown using the ordinary differential equation (ODE) approach developed for the more familiar recursive output prediction error (RPE) methods. The presented scheme converges and is relatively well conditioned compared with the ...