Analytical applications of acidic potassium permanganate as a chemiluminescence reagent

A critical review presented is of the literature concerning the use of acidic solutions of potassium permanganate to generate chemiluminescence during the oxidation of both organic compounds and inorganic species. A brief overview of the reagent’s historical origin is followed by a chronological survey of its analytical applications, from what we believe to be the first report in 1975 through to those published up until mid-2001. This review does not include those papers where potassium permanganate has been used either in alkaline conditions or in conjunction with other chemiluminescence reagents.

Analytical methodology for the determination of urea: current practice and future trends

The determination of urea is important in a wide range of fields, including clinical diagnostics, environmental monitoring and food science. Numerous analytical techniques have been developed for the determination of urea, with no single technique dominant in all areas because of the diversity of applications. An overview of the existing analytical methodologies for urea is presented, and some new approaches are discussed, particularly those based on chemiluminescence detection to improve the sensitivity and the selectivity for the determination of this important analyte.

Synthesis and preliminary analytical evaluation of the chemiluminescence from (4-[4-(dichloromethylsilanyl)-butyl]-4`-methyl-2,2`-bipyridyl)bis(2,2`-bipyridyl)ruthenium(II) covalently bonded to silica particles

This paper describes, for the first time, a simple and effective synthetic route for covalently bonding the chemiluminescence reagent, (4-[4-(dichloromethylsilanyl)-butyl]-4’-methyl-2,2’-bipyridyl)bis(2,2’-bipyridyl)ruthenium(II) onto silica particles. The subsequent preparation of chemically regeneratable detection cells and their preliminary analytical evaluation with both sequential injection analysis and flow injection analysis are also reported. Unoptimised analytical figures of merit were established for standard solutions of codeine and sodium oxalate with detection limits calculated from three times the standard deviation of the blank signal, of 1 × 10^–8 M and 3 × 10^–7 M respectively. The chemically immobilised reagent exhibited some intriguing solvent and kinetic effects, which are also briefly discussed.

A purposive approach to content analysis : designing analytical frameworks

Content analysis of computer conferences provides a rich source of data for researching and understanding online learning. However, the complexities of using content analysis in a relatively new research field have resulted in researchers often avoiding this method and using more familiar methods such as survey and interview instead. This article discusses content analysis as a methodology, with emphasis on the development of analytical frameworks. The literature indicates that researchers either use or modify existing frameworks or, more commonly, develop new ones, either through grounded theory approaches or the adaptation of existing theories, concepts or models. The development and implementation of two frameworks are then discussed in detail. Both were developed purposively to investigate and evaluate firstly collaborative learning and secondly deep and surface approaches to learning as evidenced in computer conferences. The article concludes with recommendations for framework development.

An analytical constitutive law for twinning dominated flow in magnesium

The progress of “c-axis tension” twinning in magnesium is represented in an analytical framework and this is used as a basis for predicting the flow stress. The difference in the stress–strain curves between tension and compression can thus be modelled with a change to a parameter that reflects the fraction of grains that undergo twinning.

Flavour as an analytical tool : an anti-inflammatory compound in olive oil

The chemical senses have been underutilised as analytical instruments, although as detectors of chemicals our senses are highly specialised biological machines. This paper reviews the current state of knowledge of the chemical senses. A novel technique was used to isolate and identify a flavour-active non-steroidal antiinflammatory compound in virgin olive oil.

Analytical communication networks model for enterprise grid computing

This paper addresses the problem of performance analysis based on the communication modeling of large-scale heterogeneous distributed systems, with an emphasis on enterprise Grid computing systems. The study of communication layers is important, as the overall performance of a distributed system often critically hinges on the effectiveness of this part. We propose an analytical model that is based on probabilistic analysis and queuing networks. The proposed model considers the processor as well as network heterogeneity of the enterprise Grid system. The model is validated through comprehensive simulations, which demonstrate that the proposed model exhibits a good degree of accuracy for various system sizes, and under different working conditions.

Analytical modeling of interconnection networks in heterogeneous multi-cluster systems

In data-intensive distributed systems, replication is the most widely used approach to offer high data availability, low bandwidth consumption, increased fault-tolerance and improved scalability of the overall system. Replication-based systems implement replica control protocols that enforce a specified semantics of accessing the data. Also, the performance depends on a number of factors, the chief of which is the protocol used to maintain consistency among object replica. In this paper, we propose a new low-cost and high data availability protocol called the box-shaped grid structure for maintaining consistency of replicated data on networked distributed computing systems. We show that the proposed protocol provides high data availability, low communication costs, and increased fault-tolerance as compared to the baseline replica control protocols.

Playing a critical role: experiential learning resources and analytical media studies in higher education

This article compares two Information and Communication Technologies (ICTs) used in the Faculty of Arts, Deakin University Australia, and investigates the relationships between technology, pedagogy and key issues in the teaching and practice of public relations, in a media studies context. The online role-play ‘Save Wallaby Forest’ and the e-simulation ‘PRessure Point! Getting Framed (GF), in their different ways, afford learning  environments with capabilities that present public relations and media students with opportunities to discover a critical consciousness, break out of naturalised world-views, and explore alternative approaches to organisational communication. Furthermore, they present students with complex ethical issues to investigate based around the idea that media industries are powerful discursive producers and reproducers of social norms, values and beliefs which in turn shape notions of identity and influence the formation of public opinion in society (Fairclough 1999; Habermas 1995). This article explores the intersections and differences between these distinct ICTs in their relationships to a constructivist learning approach and ethical questions about how public relations both produces and reproduces world views through practice. This interacting nexus – between technology, pedagogy and theme – is significant because “what happens in the learning process” relates to the learning outcome and therefore has the potential to develop holistic reflexivity in studies of public relations (Laurillard 2003, p.42).

Analytical model of pass-by-pass strain in rod (or bar) rolling and its applications to prediction of austenite grain size

Rod rolling is a process where the deformation state of the workpiece between the work rolls is quite different from the strip rolling process. However, in most microstructure evolution models, the simple area strains (natural logarithm of the area reduction ratio) multiplied by a constant have been used to compute pass-by-pass evolution of austenite grain size (AGS) in rod (or bar) rolling, without any verification. The strains at a given pass play a crucial role in determining the recrystallization behavior (static or dynamic). In this study, an analytical model that calculates the pass-by-pass strain and strain rate in rod rolling has been developed and verified by conducting four-pass (oval–round) bar and plate rolling experiments. Numerical simulations have then been carried out for the four-pass rolling sequence using the area strain model and the new analytical model, focusing on the effect of the method for calculating the strain on the recrystallization behavior and evolution of AGS. The AGS predicted was compared with those obtained from hot torsion tests. It is shown that the analytical model developed in this study is more appropriate in the analysis of bar (or rod) rolling. It was found that the recrystallization behavior and evolution of AGS during this process were influenced significantly by the calculation method for the deformation parameters (strain and strain rate). The pass-by-pass strain obtained from the simple area strain model is inadequate to be used as an input to the equations for recrystallization and AGS evolution under these rolling conditions.

Scope for further analytical solutions for constant flux infiltration into a semi-infinite soil profile or redistribution in a finite soil profile.

We attempt to generate new solutions for the moisture content form of the one-dimensional Richards' [1931] equation using the Lisle [1992] equivalence mapping. This mapping is used as no more general set of transformations exists for mapping the one-dimensional Richards' equation into itself. Starting from a given solution, the mapping has the potential to generate an infinite number of new solutions for a series of nonlinear diffusivity and hydraulic conductivity functions. We first seek new analytical solutions satisfying Richards' equation subject to a constant flux surface boundary condition for a semi-infinite dry soil, starting with the Burgers model. The first iteration produces an existing solution, while subsequent iterations are shown to endlessly reproduce this same solution. Next, we briefly consider the problem of redistribution in a finite-length soil. In this case, Lisle's equivalence mapping is generalized to account for arbitrary initial conditions. As was the case for infiltration, however, it is found that new analytical solutions are not generated using the equivalence mapping, although existing solutions are recovered.

Analytical performance modeling of the enterprise grid computing

This paper addresses the problem of performance modeling of large-scale heterogeneous distributed systems with emphases on enterprise grid computing systems. To this end, we present an analytical model that can be employed to explore the effectiveness of different design approaches so that one can have an intelligent choice during design and evaluation a cost-effective large-scale heterogeneous distributed computing system. The model is validated through comprehensive simulation.

Analytical interconnection networks model for multi-cluster computing systems

This paper addresses the problem of interconnection networks performance modeling of large-scale distributed systems with emphases on multi-cluster computing systems. The study of interconnection networks is important because the overall performance of a distributed system is often critically hinged on the effectiveness of its interconnection network. We present an analytical model that considers stochastic quantities as well as processor heterogeneity of the target system. The model is validated through comprehensive simulation, which demonstrates that the proposed model exhibits a good degree of accuracy for various system sizes and under different operating conditions.

Analytical network modeling of heterogeneous large-scale cluster systems

The study of the communication networks for distributed systems is very important, since the overall performance of these systems is often depends on the effectiveness of its communication network. In this paper, we address the problem of networks modeling for heterogeneous large-scale cluster systems. We consider the large-scale cluster systems as a typical cluster of clusters system. Since the heterogeneity is becoming common in such systems, we take into account network as well as cluster size heterogeneity to propose the model. To this end, we present an analytical network model and validate the model through comprehensive simulation. The results of the simulation demonstrated that the proposed model exhibits a good degree of accuracy for various system organizations and under different working conditions.