Planar electromagnetic bandgap structures

This article presents various novel and conventional planar electromagnetic bandgap (EBG)-assisted transmission lines. Both microstrip lines and coplanar waveguides (CPWs) are designed with circular, rectangular, annular, plus-sign and fractal-patterned EBGs and dumbbell-shaped defected ground structure (DGS). The dispersion characteristics and the slow-wave factors of the design are investigated. (c) 2006 Wiley Periodicals, Inc.

Bait avoidance and habitat use by the roof rat, Rattus rattus, in a piggery

The acceptance of four anticoagulant rodenticide baits was evaluated in a piggery. The bait bases were cracked wheat, wax block, pig feed, and Racumin Paste(R). Mean daily consumption of each bait was poor (< 5 g). Mean activity index measured with tracking plates did not change significantly throughout pre-baiting (3 days), baiting (37) or post-baiting (7), indicating that the baits had no impact on the population. The same baiting regime applied simultaneously in nearby stables with lower feed availability induced a significantly higher mean consumption of the cracked wheat based bait, and the activity index declined to zero at day 23, indicating that the rats were eradicated. The failure of the baits to control rats in the piggery was possibly due to the poor bait acceptance caused by the abundant feed supply. Results of live-trapping and radio- and spool-and-line tracking indicated that the population was confined within the piggery; lower windowsills were the most used above-ground structure for movements; and minimum home range span was 17 m. We suggest that rodent control should be implemented within the confines of the piggery to reduce the risk to non-target animals, and that mortality agents should be placed less than or equal to 17 in apart arboreally for the roof rat. (C) 2004 Elsevier Ltd. All rights reserved.

Development of forest structure on cleared rainforest land in eastern Australia under different styles of reforestation

Rainforests in eastern Australia have been extensively cleared over the past two centuries. In recent decades, there have been increasing efforts to reforest some of these cleared lands, using a variety of methods, to meet a range of economic and environmental objectives. However, the extent to which the various styles of reforestation restore structure, composition and ecological function to cleared land is not presently understood. In this study, we develop and apply a method for quantifying the structural attributes of reforestation sites in tropical and subtropical Australia. The types of reforestation studied were plantation monocultures, mixed-species cabinet timber plots, diverse restoration plantings and unmanaged regrowth. Two age classes of reforestation were examined: 'young' (5-22 years), incorporating sites from all categories, and 'old' (30-70 years), in which only monoculture plantations and regrowth were represented. A total of 104 sites were surveyed including reference sites in intact rainforest and pasture. Intact rainforest was characterised by a suite of complex structural features including abundant special life forms (vines, epiphytes, hemi-epiphytes and strangler figs), a dense stand of trees in a range of size classes, a closed canopy, a shrubby understorey and a well-developed ground layer of leaf litter and woody debris. These features were lost on conversion to pasture. While all types of reforestation returned some elements of structural complexity to cleared land, young plantation monocultures, cabinet timber plots and young regrowth had a relatively simple structure. These sites typically had a low density of woody stems, a relatively open canopy and grassy ground cover, and lacked large trees, coarse woody debris and most special life forms. Restoration plantings and old regrowth were more complex, with a high density of woody stems, a relatively closed canopy and shrubby understorey. Old monoculture plantations in the tropics had acquired many of the structural attributes of intact forest, however this was not the case in the subtropics, where plantations were subject to more intensive management. The marked differences in structural complexity between sites suggest that the different types of reforestation practiced in eastern Australia are likely to vary considerably in their value as habitat for rainforest biota. (C) 2003 Elsevier Science B.V. All rights reserved.

Theory of strongly correlated electron systems. II. Including correlation effects into electronic structure calculations

We have previously shown that a division of the f-shell into two subsystems gives a better understanding of the cohesive properties as well the general behavior of lanthanide systems. In this article, we present numerical computations, using the suggested method. We show that the picture is consistent with most experimental data, e.g., the equilibrium volume and electronic structure in general. Compared with standard energy band calculations and calculations based on the self-interaction correction and LIDA + U, the f-(non-f)-mixing interaction is decreased by spectral weights of the many-body states of the f-ion. (c) 2005 Wiley Periodicals, Inc.

Finding common ground in team-based qualitative research using the convergent interviewing method

Research councils, agencies, and researchers recognize the benefits of team-based health research. However, researchers involved in large-scale team-based research projects face multiple challenges as they seek to identify epistemological and ontological common ground. Typically, these challenges occur between quantitative and qualitative researchers but can occur between qualitative researchers, particularly when the project involves multiple disciplinary perspectives. The authors use the convergent interviewing technique in their multidisciplinary research project to overcome these challenges. This technique assists them in developing common epistemological and ontological ground while enabling swift and detailed data collection and analysis. Although convergent interviewing is a relatively new method described primarily in marketing research, it compares and contrasts well with grounded theory and other techniques. The authors argue that this process provides a rigorous method to structure and refine research projects and requires researchers to identify and be accountable for developing a common epistemological and ontological position.