3,805 research outputs found
A systematic review of arthropod community diversity in association with invasive plants
Invasive plants represent a significant financial burden for land managers and also have the potential to severely degrade ecosystems. Arthropods interact strongly with plants, relying on them for food, shelter, and as nurseries for their young. For these reasons, the impacts of plant invasions are likely strongly reflected by arthropod community dynamics including diversity and abundances. A systematic review was conducted to ascertain the state of the literature with respect to plant invaders and their associated arthropod communities. We found that the majority of studies did not biogeographically contrast arthropod community dynamics from both the home and away ranges and that studies were typically narrow in scope, focusing only on the herbivore feeding guild, rather than assessing two or more trophic levels. Importantly, relative arthropod richness was significantly reduced on invasive plant species. Phylogenetic differences between the invasive and local plant community as well as the plant functional group impact arthropod diversity patterns. A framework highlighting some interaction mechanisms between multiple arthropod trophic levels and native and invasive plants is discussed and future research directions relating to these interactions and the findings herein are proposed
Language-universal constraints on the segmentation of English
Two word-spotting experiments are reported that examine whether the Possible-Word Constraint (PWC) [1] is a language-specific or language-universal strategy for the segmentation of continuous speech. The PWC disfavours parses which leave an impossible residue between the end of a candidate word and a known boundary. The experiments examined cases where the residue was either a CV syllable with a lax vowel, or a CVC syllable with a schwa. Although neither syllable context is a possible word in English, word-spotting in both contexts was easier than with a context consisting of a single consonant. The PWC appears to be language-universal rather than language-specific
Virtual EQ – the talent differentiator in 2020?
In an increasingly competitive, globalised world, knowledge-intensive industries/ services are seen as engines for success. Key to this marketplace is a growing army of ‘talent’ i.e. skilled and dedicated knowledge workers. These knowledge workers engage in non-routine problem solving through combining convergent, divergent and creative thinking across organizational and company boundaries - a process often facilitated though the internet and social media, consequently forming networks of expertise. For knowledge workers, sharing their learning with others through communities of practice embedded in new information media becomes an important element of their personal identity and the creation of their individual brand or e-social reputation. Part of the new knowledge/skills needed for this process becomes not only emotional intelligence (being attuned to the emotional needs of others) but being able to do this within and through new media, thus the emergence of virtual emotional intelligence (EQ). Our views of current research found that HRD practitioners in 2020 might need to consider Virtual EQ as part of their talent portfolio. However it seems that new technology has created strategies for capturing and managing knowledge that are readily duplicated and that a talent differentiator in 2020 might simply be the ability and willingness to learn
SWECS tower dynamics analysis methods and results
Several different tower dynamics analysis methods and computer codes were used to determine the natural frequencies and mode shapes of both guyed and freestanding wind turbine towers. These analysis methods are described and the results for two types of towers, a guyed tower and a freestanding tower, are shown. The advantages and disadvantages in the use of and the accuracy of each method are also described
Boiling Heat Transfer of Impinging Jets on Superheated Superhydrophobic Surfaces
Superhydrophobic surfaces possess desirable self-cleaning properties, but have also been shown to reduce heat transfer to subcooled water in impinging jet scenarios. Further investigation is required to explore the potential utility of such surfaces in high temperature applications such as rocket launch-pad cooling. Here, superheated silicon substrates with varying wettability are quenched by an impinging water jet, where the substrate temperature is above the boiling regime which has previously been unexplored. Silicon wafers are etched, coated, and integrated with an electric resistance heater and heated to temperatures up to 300 ° C before being quenched by an axisymmetric water jet. The early results of this study confirm previous conjecture that decreased surface wettability is correlated to decreased heat transfer for the described scenario
Effect of Superhydrophobic Surface Microstructure on Transient Jet Impingement Cooling
Jet impingement is an effective method of rapid surface cooling, and is highly dependent on surface condition and properties. Here, silicon surfaces are modified by ion-etching different micropatterns (posts or holes) on one side and coated with Teflon to make them superhydrophobic (SH). The other side of the surface has a screen-printed resistance heater. Surfaces are heated to temperatures between 200 to 320 °C, and then impinged on by a pure water jet at room temperature with flow rates ranging from 6 to 18 mL/s. Results show that there is little effect of microstructure, although hole surfaces and shorter microstructures tend to have slightly higher heat transfer. Heat transfer from the surfaces to the jet is shown to be highly dependent on jet flow rate, but not surface temperature
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