The potential of geospatial technology for monitoring peatland environments

There have been significant advances in the spectral and spatial resolution of data collected from spaceborne, airborne and terrestrial based geospatial technologies over the past 20 years. In sensitive peatland ecosystems, the non-intrusive application of these technologies offers great potential to improve vegetation monitoring and topographical mapping. This paper discusses the potential of geospatial technologies for monitoring vegetation, mapping natural erosion features and assessing artificial drainage with reference to two peatland sites in England. Earth Observation (EO) data can now provide colour imagery with spatial resolution comparable to conventional aerial photography. Enhanced spectral resolution of spaceborne sensors has also increased the accuracy of automated image classification for bog vegetation and EO data may challenge the relevance of conventional aerial photography in landscape-scale assessment. Ultra-high resolution data achievable from Unmanned Aerial Vehicle (UAV) and Terrestrial Laser Scanner (TLS) technologies are providing unprecedented levels of detail from remote sensing. UAV imagery now provides the possibility of identifying individual plants which greatly increases a researcher’s ability to map vegetation from aerial imagery. UAV derived elevation data, combined with the capability of TLS, provide enhanced resolution of gully and artificial drain morphology compared to airborne LiDAR and allow a new approach for quantifying erosion. These technologies provide opportunities to extend traditional surveys over far larger areas than was previously possible and can assist both in targeting areas for future restoration and in monitoring of subsequent change. Traditional survey methods will however maintain an important role in assessing many aspects of peatlands, as they not only provide information to verify remotely sensed data, but are currently the only method that can ‘see’ underneath peatland vegetation

Transglutaminase-catalyzed preparation of chitosan-ovalbumin films

Microbial transglutaminase was employed as catalyst for preparing chitosan–ovalbumin films. The films showed low solubility at a wide range of pH and underwent to a good enzymatic hydrolysis with trypsin. The degree of swelling was reduced and the mechanical resistance of the chitosan–ovalbumin films increased from 24 to 35MPa after enzymatic treatment with transglutaminase. The barrier efficiency toward water vapour was slightly improved for the films prepared by transglutaminase-mediated cross-linking

Enhanced quench propagation in 2G-HTS coils co-wound with stainless steel or anodised aluminium tapes

Early quench detection and thermal stability of superconducting coils are of great relevance for practical applications. Magnets made with second generation high temperature superconducting (2G-HTS) tapes present low quench propagation velocities and therefore slow voltage development and high local temperature rises, which may cause irreversible damage. Since quench propagation depends on the anisotropy of the thermal conductivity, this may be used to achieve an improvement of the thermal stability and robustness of 2G-HTS coils. On pancake type coils, the thermal conductivity along the tapes (coil's azimuthal direction) is mostly fixed by the 2G-HTS tape characteristics, so that the reduction of anisotropy relies on the improvement of the radial thermal conductivity, which depends on the used materials between superconducting tapes, as well as on the winding and impregnation processes. In this contribution, we have explored two possibilities for such anisotropy reduction: by using anodised aluminium or stainless steel tapes co-wound with the 2G-HTS tapes. For all the analysed coils, critical current distribution, minimum quench energy values and both tangential and radial quench propagation velocities at different temperatures and currents are reported and compared with the results of similar coils co-wound with polyimide (Kapton®) tapes.This work was supported by the Spanish Ministerio de Economía y Competitividad and the European FEDER Program (Projects MAT2011-22719 and ENE-2014-52105-R), and by the Gobierno de Aragón (research group T12).Peer reviewe

Analysis of quantum conductance of carbon nanotube junctions by the effective mass approximation

The electron transport through the nanotube junctions which connect the different metallic nanotubes by a pair of a pentagonal defect and a heptagonal defect is investigated by Landauer's formula and the effective mass approximation. From our previous calculations based on the tight binding model, it has been known that the conductance is determined almost only by two parameters,i.e., the energy in the unit of the onset energy of more than two channels and the ratio of the radii of the two nanotubes. The conductance is calculated again by the effective mass theory in this paper and a simple analytical form of the conductance is obtained considering a special boundary conditions of the envelop wavefunctions. The two scaling parameters appear naturally in this treatment. The results by this formula coincide fairly well with those of the tight binding model. The physical origin of the scaling law is clarified by this approach.Comment: RevTe

Putrescine-polysaccharide conjugate as transglutaminase substrates and their possible use in producing crosslinked films

Putrescine (1,4-diaminobutane) was covalently linked to alginate and low-methoxyl pectin to synthesize new aminated polysaccharides. Both putrescine-pectin and -alginate conjugates, although the latter at higher concentrations, were found to be able to act as effective acyl acceptor transglutaminase substrates in vitro using both dimethylated casein and soy flour proteins as acyl donors. Monodansylcadaverine, a well known acyl acceptor transglutaminase substrate, dose-dependently counteracted the covalent binding of the aminated polysaccharides to the proteins. Putrescine-pectin conjugate was also tested to prepare, in combination with soy flour proteins, edible films in the presence of purified microbial transglutaminase. Characterization of the enzymatically crosslinked films showed a significant decreased water vapor permeability, with respect to the ones obtained with non-aminated pectin in the presence of transglutaminase, as well as improved mechanical properties, such as high extensibility. Possible biotechnological applications of hydrocolloid films containing putrescine-polysaccharide derivatives enzymatically crosslinked to proteins were suggested

Chitosan-whey protein edible films produced in the absence or presence of transglutaminase: Analysis of their mechanical and barrier properties

Chitosan-whey protein edible films with different protein concentrations were prepared in the absence or presence of microbial transglutaminase as cross-linking agent. The films prepared in the presence of the enzyme showed low solubility at a wide range of pH, a lower degree of swelling, and good biodegradability following protease treatments. The presence of transglutaminase induced also an enhancement in film mechanical resistance and a reduction in their deformability. Finally, the barrier efficiency toward oxygen and carbon dioxide was found to be markedly improved in the cross-linked films which showed also a lower permeability to water vapor. Some potential practical applications of transglutaminase-treated chitosan-whey protein films are suggested

Atmospheric corrosion of reference metals in Antarctic sites

This paper presents the results obtained at three Antarctic test sites participating in the >Ibero-American Map of Atmospheric Corrosiveness> (MICAT), a project on atmospheric corrosion carried out during the period 1988-1994 at some 70 sites distributed across 12 countries of the Latin-American region, Spain and Portugal. The three Antarctic sites are located near the coastline. The singular climatic characteristics of Antarctic regions are related with the purity of the air, the absence of rainfall and the formation of ice on the metallic surface during an important part of the exposure time. However, electrochemical activity is possible below ice layers. This situation affects the structure and morphology of corrosion product films and the resulting corrosion rates of metallic surfaces. © 2004 Elsevier B.V. All rights reserved.Peer Reviewe

Використання кавітаційних пристроїв в харчовій промисловості

We present a direct experimental investigation of the thermal ordering in an artificial analogue of an asymmetric two-dimensional Ising system composed of a rectangular array of nano-fabricated magnetostatically interacting islands. During fabrication and below a critical thickness of the magnetic material the islands are thermally fluctuating and thus the system is able to explore its phase space. Above the critical thickness the islands freeze-in resulting in an arrested thermalized state for the array. Determining the magnetic state we demonstrate a genuine artificial two-dimensional Ising system which can be analyzed in the context of nearest neighbor interactions

Carbon nanotube-based quantum pump in the presence of superconducting lead

Parametric electron pump through superconductor-carbon-nanotube based molecular devices was investigated. It is found that a dc current, which is assisted by resonant Andreev reflection, can be pumped out from such molecular device by a cyclic variation of two gate voltages near the nanotube. The pumped current can be either positive or negative under different system parameters. Due to the Andreev reflection, the pumped current has the double peak structure around the resonant point. The ratio of pumped current of N-SWNT-S system to that of N-SWNT-N system (I^{NS}/I^N) is found to approach four in the weak pumping regime near the resonance when there is exactly one resonant level at Fermi energy inside the energy gap. Numerical results confirm that in the weak pumping regime the pumped current is proportional to the square of the pumping amplitude V_p, but in the strong pumping regime the pumped current has the linear relation with V_p. Our numerical results also predict that pumped current can be obtained more easily by using zigzag tube than by using armchair tube