Using open-source software and digital imagery to efficiently and objectively quantify cover density of an invasive alien plant species.

The most commonly used method for measuring vegetation cover is visual estimation, which is highly subjective, potentially leading to measurement errors. This poses serious implications to the assessment and continued management of plant species cover, for example in the control of invasive plant species. Morphological analysis of digital imagery has, to date, been primarily applied in the classification of landscape features. Our novel application of morphological image analysis provides an objective method for detection and accurate cover assessment of an invasive alien plant species (IAS), giving reduced measurement errors when compared to visual estimation. Importantly, this method is entirely based on free software. Guidos Toolbox is a collection of generic raster image processing routines, including Morphological Spatial Pattern Analysis (MSPA), which classifies and quantifies features according to shape. MSPA was employed in this study to detect and quantify cover of invasive Petasites pyrenaicus (Winter heliotrope) in digital images of 1 m × 1 m plots. Its efficacy was compared to that of two other methods- GIS Digitisation (used as an accurate baseline) and Visual Estimation (standard method). We tested the limit of MSPA usability on images of varying complexity, i.e. "simple", intermediate" or "complex", depending on presence/absence of other vascular plant species and the species richness of plot. Our results show good agreement between all three methods. MSPA measurement of P. pyrenaicus cover was most closely aligned with the GIS Digitisation (concordance correlation coefficients of 0.966). Visual Estimation was less closely aligned with GIS Digitisation (concordance correlation coefficients of 0.888). However, image complexity resulted in differing levels of agreement; with the closest agreement being achieved between MSPA and GIS Digitisation when used on images of lower and higher complexity. MSPA consistently provides higher accuracy and precision for P. pyrenaicus cover measurement than the standard Visual Estimation method. Our methodology is applicable to a range of focal vegetation species, both herbaceous and graminoid. Future application of MSPA for larger-scale surveying and monitoring via remote sensing is discussed, potentially reducing resource demands and increasing cover measurement consistency and accuracy. We recommend this method forms part of vegetation management toolkits for not only environmental managers, but for anyone concerned with plant cover assessment, from agricultural systems to sustainable resource use.

Hedgerow typology and condition analysis to inform greenway design in rural landscapes.

Over the past decades, Western European hedgerows have been declining as a result of land use change. Disused infrastructure corridors such as railways and tramways can host a range of existing and returning semi-natural habitats, including extensive hedgerow networks. However, long term corridor abandonment can result in network deterioration to gappy hedgerows, lines of trees and eventually individual scrub features. The loss of hedgerows results in the loss of many ecosystem services, habitat for species and landscape connectivity. This highlights an increasing need to find innovative solutions to recognise and appropriately maintain these hedgerow networks. European Greenways typically 'upcycle' disused infrastructure transport corridors for multi-use, non-motorised recreational public infrastructure. The potential for European greenways to maintain and restore hedgerows is of interest as a novel planning mechanism for enhancing green infrastructure in general. The aim of this study is to inform Greenway design and management through the evaluation of hedgerow significance (historical, ecological and landscape), condition and composition within a rural European Greenway landscape context. 81 hedgerows were sampled along a 70 km proposed Greenway route traversing a range of extensive and intensive landscapes. Hedgerows were surveyed using a rapid field score sheet which enabled significance and condition scoring. A hedgerow typology was subsequently developed based on species composition assemblages. Hedgerows were found to be highly ecologically significant and species rich throughout the route. On-going land use intensification was evident as significant sections of the former railway corridor were subsumed into intensive agriculture and afforestation. Management recommendations need to be adapted to the particular hedgerow group and surrounding landscape context, and take into account the varied requirements of different taxonomic groups. The study findings show Greenways have the potential to act as multi-functional green infrastructure (accomplishing both ecological and recreational objectives) through informed design to reinforce their nature conservation role and recognising hedgerows as integral landscape feature of Greenway corridor, at local level and as part of a wider European network.

Landscape typology and ecological connectivity assessment to inform Greenway design.

European Greenway developments typically 'upcycle' disused transport corridors for multi-use, non-motorised public infrastructure. The linear and relatively undisturbed nature of these disused infrastructures means many currently function as high quality ecological corridors. Corridors providing connectivity among habitat patches can mitigate the effects of fragmentation on biodiversity, allowing species dispersal throughout the landscape matrix. The sustainable integration of Greenway infrastructure and ecological corridor functions requires consideration during design, development and maintenance stages, taking into account surrounding landscape composition and connectivity. This paper presents a method to characterise a proposed Greenway corridor landscape, focusing on habitat composition and ecosystems connectivity. Morphological Spatial Pattern Analysis (MSPA) was used to comprehensively describe the structural connectivity of linear and spatial habitats occurring within the study area. A subsequent multivariate classification of structural connectivity and habitat data determined six distinctive landscape characters. Interpretation of these landscape characters highlights the principal habitat compositions and connectivity conditions in terms of habitat core, links and potential linkages. For example one landscape was intensified, yet retained high woodland connectivity, while another diverse habitat landscape supported little connectivity for woodland and grasslands. The results of this study suggest significant opportunities exist to enhance European landscape connectivity through informed Greenway development. Crucial habitat linkages can be optimised along Greenway infrastructure, contributing towards the realisation of European Greenways as Green Infrastructure and true sustainable projects.

Evaporation of Binary Sessile Drops: Infrared and Acoustic Methods To Track Alcohol Concentration at the Interface and on the Surface.

Evaporation of droplets of three pure liquids (water, 1-butanol, and ethanol) and four binary solutions (5 wt % 1-butanol-water-based solution and 5, 25, and 50 wt % ethanol-water-based solutions) deposited on hydrophobic silicon was investigated. A drop shape analyzer was used to measure the contact angle, diameter, and volume of the droplets. An infrared camera was used for infrared thermal mapping of the droplet's surface. An acoustic high-frequency echography technique was, for the first time, applied to track the alcohol concentration in a binary-solution droplet. Evaporation of pure alcohol droplets was executed at different values of relative humidity (RH), among which the behavior of pure ethanol evaporation was notably influenced by the ambient humidity as a result of high hygrometry. Evaporation of droplets of water and binary solutions was performed at a temperature of 22 °C and a mean humidity of approximately 50%. The exhaustion times of alcohol in the droplets estimated by the acoustic method and the visual method were similar for the water-1-butanol mixture; however, the time estimated by the acoustic method was longer when compared with that estimated by the visual method for the water-ethanol mixture due to the residual ethanol at the bottom of the droplet.

High-frequency acoustic for nanostructure wetting characterization.

Nanostructure wetting is a key problem when developing superhydrophobic surfaces. Conventional methods do not allow us to draw conclusions about the partial or complete wetting of structures on the nanoscale. Moreover, advanced techniques are not always compatible with an in situ, real time, multiscale (from macro to nanoscale) characterization. A high-frequency (1 GHz) acoustic method is used for the first time to characterize locally partial wetting and the wetting transition between nanostructures according to the surface tension of liquids (the variation is obtained by ethanol concentration modification). We can see that this method is extremely sensitive both to the level of liquid imbibition and to the impalement dynamic. We thus demonstrate the possibility to evaluate the critical surface tension of a liquid for which total wetting occurs according to the aspect ratio of the nanostructures. We also manage to identify intermediate states according to the height of the nanotexturation. Finally, our measurements revealed that the drop impalement depending on the surface tension of the liquid also depends on the aspect ratio of the nanostructures. We do believe that our method may lead to new insights into nanoscale wetting characterization by accessing the dynamic mapping of the liquid imbibition under the droplet.

Acoustic tracking of Cassie to Wenzel wetting transitions.

Many applications involving superhydrophobic materials require accurate control and monitoring of wetting states and wetting transitions. Such monitoring is usually done by optical methods, which are neither versatile nor integrable. This letter presents an alternative approach based on acoustic measurements. An acoustic transducer is integrated on the back side of a superhydrophobic silicon surface on which water droplets are deposited. By analyzing the reflection of longitudinal acoustic waves at the composite liquid-solid-vapor interface, we show that it is possible to track the local evolution of the Cassie-to-Wenzel wetting transition efficiently, as induced by evaporation or the electrowetting actuation of droplets.

Development of interdigital transducer sensors for non-destructive characterization of thin films using high frequency Rayleigh waves.

In this paper, Rayleigh waves were generated and studied over a broad frequency range (5-50 MHz) and from the dispersion phenomenon, two substrate on layer type-samples with thin layer thicknesses of 1 µm and 500 nm, respectively, were characterized. The originality in this paper is the use of surface acoustic wave interdigital transducers (IDT) to generate surface waves as well as the development of a measuring device enabling an accurate estimation of the phase velocity to be obtained, which is essential in order to characterize such thin layers. Considering the excitation frequencies (5-50 MHz) and therefore the widths necessary on the electrodes for these types of IDT sensors (20-200 µm), a lift-off procedure was chosen to deposit the electrodes on the lithium niobate (LiNbO(3)) piezoelectric substrates. The use of these IDT, first enabled problems of loss and attenuation linked to the high frequency of conventional sensors (wedge sensors) to be overcome and second to carry out quasi-monochromatic measurements in order to obtain an extremely accurate estimation of the phase velocity with rapid post-processing. An inverse method provided a very precise estimation of the thickness of the layers and the elastic constants of the substrate. The estimations of the thicknesses were then confirmed by measurements with a profilometer.

Controlling the transmission of ultrahigh frequency bulk acoustic waves in silicon by 45° mirrors.

In this paper, we present a feasible microsystem in which the direction of localized ultrahigh frequency (∼1GHz) bulk acoustic wave can be controlled in a silicon wafer. Deep etching technology on the silicon wafer makes it possible to achieve high aspect ratio etching patterns which can be used to control bulk acoustic wave to transmit in the directions parallel to the surface of the silicon wafer. Passive 45° mirror planes obtained by wet chemical etching were employed to reflect the bulk acoustic wave. Zinc oxide (ZnO) thin film transducers were deposited by radio frequency sputtering with a thickness of about 1µm on the other side of the wafer, which act as emitter/receptor after aligned with the mirrors. Two opponent vertical mirrors were inserted between the 45° mirrors to guide the transmission of the acoustic waves. The propagation of the bulk acoustic wave was studied with simulations and the characterization of S(21) scattering parameters, indicating that the mirrors were efficient to guide bulk acoustic waves in the silicon wafer.

SU-8-based nanocomposites for acoustical matching layer.

SU-8, an epoxy-based photoresist, was introduced as the acoustical matching layer between silicon and water for lab-on-chip applications integrating acoustic characterization. Acoustical performances, including the acoustic longitudinal wave velocity and attenuation of the SU-8-based matching layer, were characterized at a frequency of 1 GHz at room temperature. The gain in echo characterization with a SU-8/SiO2 bilayer and with different nanocomposite monolayers made of SU-8 and TiO2 nanoparticles (size around 35 nm) between silicon and water was characterized as being above 10 dB in each case. With the increase of concentration of TiO2 in SU-8 based composites from 0 to 30 wt%, acoustical impedance of the nanocomposites increased from about 3 to 6 MRayls, respectively. The acoustical attenuation in the nanocomposites is between 0.5 and 0.6 dB/microm. The most efficient matching was obtained with the nanocomposite integrating 30 wt% TiO2 nanoparticles, with which the enhanced loss is about 0.34 dB as the attenuation is about 0.5 dB/microm. This type of matching layer has potential applications in lab-on-chip technology for high frequency transducers or in the fabrication of high frequency piezocomposites.

Integrated microfabricated systems including a purification module and an on-chip nano electrospray ionization interface for biological analysis.

We report here on an integrated microfabricated device dedicated to the preparation of biological samples prior to their on-line analysis by electrospray ionization-mass spectrometry (ESI-MS). This microfluidic device is fabricated using the negative photoresist SU-8 by microtechnology techniques. The device includes a chromatographic module plus an ESI interface for MS. The chromatographic module is dedicated to sample purification and is based on a polymer monolithic phase which includes hydrophobic moieties. The ESI interface is integrated onto the chip and is based on a capillary slot. We present here the integration of these different modules onto a single system that is fabricated via a SU-8-based microtechnology route. We present also their testing for the purification of peptide samples. This started with a partial integration step with the combination of at least two of the modules (microsystem + monolith; microsystem + nib) and their test before the fabrication and testing of fully integrated microsystems.

Monoliths for microfluidic devices in proteomics.

We report here on the preparation of monolithic capillary columns in view to their integration in a microsystem for on-chip sample preparation before their on-line analysis by electrospray and mass spectrometry (ESI-MS). These monolithic columns are based on polymer materials and consist of reverse phases for peptide separation and/or desalting. They were prepared using lauryl methacrylate (LMA), ethylene dimethacrylate (EDMA) as well as a suitable porogenic mixture composed of cyclohexanol and ethylene glycol. The resulting stationary phases present thus a C12-functionality. The LMA-based columns were first prepared in a capillary format using capillary tubing of 75 microm i.d. and tested in nanoLC-MS experiments for the separation of a commercial Cytochrome C digest composed of 12 peptidic fragments whose isoelectric point values and hydrophobic character cover a wide range. The LMA-based columns were capable of separating the peptidic fragments and their performances were seen to be similar as those of standard commercial columns dedicated to proteomic purposes with calculated separation efficiencies up to 145 x 10(3) plates/m. Monolithic LMA-based phases were then successfully polymerized in microchannels fabricated using the negative photoresist SU-8. After the polymerization, the systems were seen to withstand the pressures applied during the nanoLC-MS separation tests that were carried out in the same conditions as for the monolithic capillary columns. The pressure drop during these tests of the in-microchannel monoliths was as high as 50 bar; however, the separation was not as good as for a capillary format which could be accounted for by the monolith dimensions.