Electrical conductivity imaging via contactless measurements

A new imaging modality is introduced to image electrical conductivity of biological tissues via contactless measurements. This modality uses magnetic excitation to induce currents inside the body and measures the magnetic fields of the induced currents. In this study, the mathematical basis of the methodology is analyzed and numerical models are developed to simulate the imaging system. The induced currents are expressed using the A-phi formulation of the electric field where A is the magnetic vector potential and phi is the scalar potential function. It is assumed that A describes the primary magnetic vector potential that exists in the absence of the body. This assumption considerably simplifies the solution of the secondary magnetic fields caused by induced currents. In order to solve phi for objects of arbitrary conductivity distribution a three-dimensional (3-D) finite-element method (FEM) formulation is employed. A specific 7 x 7-coil system is assumed nearby the upper surface of a 10 x 10 x 5-cm conductive body. A sensitivity matrix, which relates the perturbation in measurements to the conductivity perturbations, is calculated. Singular-value decomposition of the sensitivity matrix shows various characteristics of the imaging system. Images are reconstructed using 500 voxels in the image domain, with truncated pseudoinverse. The noise level is assumed to produce a representative signal-to-noise ratio (SNR) of 80 dB. It is observed that it is possible to identify voxel perturbations (of volume 1 cm3) at 2 cm depth. However, resolution gradually decreases for deeper conductivity perturbations.     

Biochar: maximising the benefits

There have been many studies on the benefits of producing biochar (black carbon) from organic wastes. Incorporating biochar into soils provides numerous environmental and financial benefits, which this paper examines. Nevertheless, there is no policy yet to apply biochar at farm level in Australia. This article discusses nine critical factors that need to be considered for maximising the environmental and financial farm benefits from the use of biochar.     

An analysis of Australia’s carbon pollution reduction scheme

The authors review the decision‐making since the Labour Government came into office (November 2007). The Australian Government’s ‘Carbon Pollution Reduction Scheme’ White Paper (15 December 2008) proposes that an Australian Emissions Trading Scheme (AETS) be implemented in mid‐2010. Acknowledging that the scheme is comprehensive, the paper finds that in many cases, Australia will take a softer approach to climate change through the AETS than the European Union ETS (EUETS). The paper assesses key issues in the White Paper such as emissions reduction targets, GHG coverage, sectoral coverage, inclusion of unlimited quantities of offsets from Kyoto international markets and exclusion of deforestation activities.     

Making touch-based kiosks accessible to blind users through simple gestures

Touch-based interaction is becoming increasingly popular and is commonly used as the main interaction paradigm for self-service kiosks in public spaces. Touch-based interaction is known to be visually intensive, and current non-haptic touch-display technologies are often criticized as excluding blind users. This study set out to demonstrate that touch-based kiosks can be designed to include blind users without compromising the user experience for non-blind users. Most touch-based kiosks are based on absolute positioned virtual buttons which are difficult to locate without any tactile, audible or visual cues. However, simple stroke gestures rely on relative movements and the user does not need to hit a target at a specific location on the display. In this study, a touch-based train ticket sales kiosk based on simple stroke gestures was developed and tested on a panel of blind and visually impaired users, a panel of blindfolded non-visually impaired users and a control group of non-visually impaired users. The tests demonstrate that all the participants managed to discover, learn and use the touch-based self-service terminal and complete a ticket purchasing task. The majority of the participants completed the task in less than 4?min on the first attempt.     

A minireview of effects of green tea on energy expenditure

In recent years, individuals have begun to tend more frequently to some natural and herbal products to be used alone or as a combination with diet and exercise for ensuring the weight loss. Green tea is the leading one of these products. In some studies, it is reported that the green tea causes an increase in thermogenesis and substrate with fat oxidation by affecting on the sympathetic nervous system. It is reported that green tea has two main components that are associated with energy expenditure. One of them is caffeine and the other is catechin content. Each of these two components has an impact on energy mechanism separately. In this minireview article, mechanisms of action and effects of caffeine and catechin, which are found in green tea composition, on energy expenditure are assessed.     

Medium term power planning with bilateral contracts

This paper addresses the optimal management of hydropower resources on medium term. The objective is to maximize the expected revenue of a producer, and the decision variables are generation and forward contracts in each period for each scenario. Stochastic linear and nonlinear programming has been used as a framework for modeling and solution. Results are exposited for a Norwegian power producer participating in Nord Pool, the Nordic power exchange.     

Abundance and nutrient limiting growth rate of heterotrophic bacterio-plankton in Himalayan foot hill Lake Phewa, Nepal

We examined heterotrophic bacterial abundance, chlorophyll- a concentration and resources limiting bacterial growth from October 2004 to August 2005 in Lake Phewa. The lake has a large watershed that covers ≈435 ha of water surface surrounded by ≈23-time large catchment area that might receive up to 4850 mm annual precipitation. During the study, bacterial abundance ranged from 3.2 to 9.9 × 10⁶ cells mL⁻¹, and chlorophyll- a varied from 2 to 32 μg L⁻¹. Bacterial abundance and chlorophyll- a weakly correlated ( r  = 0.40, n  = 77, P  < 0.1) in the lake. Experiments on resources, glucose (C), nitrogen (N), phosphorus (P) alone and in combination (CNP) limiting bacterial growth rate, were examined using dilution bioassays. Experimental bottles enriched with resources and controls without enrichment (in triplicate) were incubated in situ for 48 h at collection depth. Results showed that C, N and P in combination significantly (at 5% level) stimulated bacterial growth rate. Bioassays with single resource additions showed P as main nutrient limiting bacterial growth comparing with C and N, implying that rainfall received in the catchment might convey adequate resources causing increased P deficiency for bacterial growth in Himalayan foot hill Lake Phewa.     

A comparative analysis of global stakeholders’ perceptions of the governance quality of the clean development mechanism (CDM) and reducing emissions from deforestation and forest degradation (REDD+)

The Clean Development Mechanism (CDM) and the nascent solution of Reducing Emissions from Deforestation and Forest Degradation (REDD+) are two global market-based mechanisms that link developed and developing countries. This paper provides a quantitative and qualitative analysis of global-level stakeholders’ perceptions regarding the governance of the CDM focusing on environmental, social, economic, governmental and institutional participants. The research conducted was by means of an anonymous online survey using an analytical approach based on principles, criteria and indicators (PC&I). It compares these findings with the results of a similar survey conducted by the authors on REDD+. Stakeholders from both developed countries and the developing countries were asked to rate the quality of these mechanisms against 11 performance indicators using a Likert scale (1–5). Overall, the results of CDM stakeholders from both developed and developing countries were very similar, indicating a common perception. The highest and lowest total scores were obtained from institutional and social stakeholders, respectively, demonstrating that these two groups have considerable differences in perceptions from other interests. CDM failed two indicators, ‘equality’ and ‘resources’, and passed all other nine indicators only marginally. The performance of REDD+ was much higher than CDM in all aspects of governance surveyed. The major differences were in ‘equality’ and ‘problem solving’, followed by ‘transparency’ and ‘democracy’. If the CDM is to continue in the post-Kyoto period, some major systemic changes in governance are necessary. Here, there are some lessons to be learnt from REDD+.