Discrimination of vegetation types in alpine sites with ALOS PALSAR-, RADARSAT-2-, and lidar-derived information

Natural vegetation monitoring in the alpine mountain range is a priority in the European Union in view of climate change effects. Many potential monitoring tools, based on advanced remote sensing sensors, are still not fully integrated in operational activities, such as those exploiting very high-resolution synthetic aperture radar (SAR) or light detection and ranging (lidar) data. Their testing is important for possible incorporation in routine monitoring and to increase the quantity and quality of environmental information. In this study the potential of ALOS PALSAR and RADARSAT-2 SAR scenes' synergic use for discrimination of different vegetation types was tested in an alpine heterogeneous and fragmented landscape. The integration of a lidar-based canopy height model (CHM) with SAR data was also tested. A SPOT image was used as a benchmark to evaluate the results obtained with different input data. Discrimination of vegetation types was performed with maximum likelihood classification and neural networks. Six tested data combinations obtained more than 85% overall accuracy, and the most complex input which integrates the two SARs with lidar CHM outperformed the result based on SPOT. Neural network algorithms provided the best results. This study highlights the advantages of integrating SAR sensors with lidar CHM for vegetation monitoring in a changing environment.     

Viable synthesis of a self-assembling regioregular thiophenic copolymer for second-order non-linear optics

Regioregular azobenzene-substituted polythiophenic copolymers were prepared by a regiospecific organometallic polycondensation procedure based on a Grignard metathesis reaction. Copolymers with a high content of chromophoric groups in the side chains and a high degree of configurational order of the backbones were obtained. A sample was also functionalized with hydroxyalkyl chains capable of setting up ordered supramolecular structures through hydrogen bonds. The final materials were fully characterized via NMR, IR, elemental analysis, GPC, DSC and X-ray diffraction. Moreover, measurements of NLO activity on polymer films showed the synthetic strategies adopted and monomers used to be correct. Values obtained by the in situ deprotection of the interacting functional groups after the alignment of the chromophorized side chains were very promising, proving the procedure to be suitable for industrial and commercial applications.     

Steam hydration-reactivation of FBC ashes for enhanced in situ desulphurization

Bed and fly ashes originating from industrial-scale fluidized bed combustors (FBCs) were steam hydrated to produce sorbents suitable for further in situ desulphurization. Samples of the hydrated ash were characterized by X-ray diffraction analysis, scanning electron microscopy and porosimetry. Bed ashes were hydrated in a pressure bomb for 30 and 60 min at 200 °C and 250 °C. Fly ash was hydrated in an electrically heated tubular reactor for 10 and 60 min at 200 °C and 300 °C. The results were interpreted by considering the hydration process and the related development of accessible porosity suitable for resulphation. The performance of the reactivated bed ash as sulphur sorbent improved with a decrease of both the hydration temperature and time. For reactivated fly ash, more favourable porosimetric features were observed at longer treatment times and lower hydration temperatures. Finally, it was shown that an ashing treatment (at 850 °C for 20 min) promoted a speeding up of the hydration process and an increase in the accessible porosity.     

Electrochemical behavior of superdense ‘LiC2’ prepared by ball-milling

The electrochemistry of superdense ‘LiC₂’ prepared by ball-milling has been investigated in EC-DMC solutions 1 M LiClO₄. A primary capacity very close to 1115 mAhg⁻¹ per carbon atom was observed during the first deintercalation cycle at constant current. The following intercalation-deintercalation cycles yielded capacity close to the theoretical value of 372 mAhg⁻¹, typical of natural graphite. Electrochemical ac-impedance spectroscopy demonstrates that a solid electrolyte interface (SEI) is formed spontaneously upon immersion of the electrode in the electrolyte. Due to the complex nature of the compound prepared by ball-milling (a mixture of lithium metal, LiC₃ and LiC₆) the mechanism of the first deintercalation is rather complex. It involves the oxidation of lithium metal at about 22 mV versus Li, followed by the decomposition of the superdense phase LiC₃ and of LiC₆ at potentials that corresponds to the normal electrochemical lithium deintercalation from LiC₆. Lithium metal in ‘LiC₂’ easily reacts with nitrogen to yield α-Li₃N that irreversibly de-intercalates about 1.8±0.1 lithium before decomposing.     

Anchoring and gliding of easy axis of 5CB on photoaligning PVCN‐F surface

Abstract— The photoaligning properties of the popular photoaligning material polyvinyl‐4(fluorocinnamate) (PVCN‐F) are presented. The aligning quality and azimuthal and zenithal anchoring energy were measured and the drift of the easy orientation axis (gliding effect) on the PVCN‐F surface, depending on UV exposure, was studied. Special attention is paid to unraveling the contribution of the adsorption liquid‐crystal molecules onto the aligning surface to the anchoring properties of PVCNF and measuring the drift of the easy orientation axis over the PVCN‐F surface. It is shown that a relatively weak azimuthal anchoring energy (W_az ～ 10^?7 ? 10^?5 J/m²) leads to strong drift of the easy axis in the azimuthal plane that was observed in a moderate (～0.1–0.3 T) magnetic field. A much stronger polar anchoring (W_zen ～ 10^?4 J/m²) allowed us to observe the essential gliding of the easy axis in the zenithal plane in a rather strong electric field (～5 V/μm).     

Color Doppler echography in the study of pseudo-occlusion of the internal carotid

The differentiation of pseudo-occlusion from complete internal carotid artery occlusion may have important clinical consequences for patients with the former tend not to benefit from reconstructive surgery. The Authors report a case in which color-Doppler duplex-scanner revealed a persisting string-like lumen that was not demonstrated by angiography. The Authors believe that ultrasonography may in future permit the reliable differentiation of pseudo-from complete carotid occlusion, thereby reducing the need for angiography.     

Heat pump enhanced gas turbine cogeneration

A significant fraction of the gaseous fuel supplied to industry will be used in medium- and small-size cogeneration plants. In this paper, a gas turbine and a gas engine of about 800 kW power output are compared at full and part load operation. When low-temperature heat (e.g., for space heating) is produced, the higher exhaust losses of the gas turbine yield a lower system efficiency, particularly at part load. A scheme is proposed to recover the exhaust gas energy by cooling to a temperature near ambient. The system features a heat pump to raise the recovered heat temperature to a usable level and an organic Rankine cycle (ORC) engine to drive the heat pump. The ORC engine uses the high-temperature fraction of the heat recovered from the exhaust. The data for the ORC engine are derived from an actual experimental engine. The performance is calculated for the system at full load.     

New High-Power Ozone Generators and Their Application In Industry

BBC ozone generators, with their high efficiency and high production density, have opened up for the exceptionally strong oxidizing agent ozone, a wide range of new possibilities in industrial applications. The article reports on measurements carried out on type OH ozone generators and on their use in industrial processes. An indication of future developments is given.     

Surgical treatment of tumors of the ampulla of Vater by local resection

The cases of six patients suffering from Vater's ampulla neoplasia were studied 1981 and 1995. All cases are described both clinically and in terms of diagnostic techniques. All patients underwent a transduodenal excision of the neoplasia. A number of factors provided an indication for ampullectomy: the extremely high surgical risk, the suspected benign nature of the lesion or the very small size of the neoplasm associated with no pre-surgery finding of lymphadenomegaly in the area. The following issues were analysed: the accuracy of results obtained by a correct pre-surgery diagnosis, short and long term complications and mortality related to surgery. All patients received a five years post-surgery follow-up. Results show that the ampullectomy can be considered, in selected cases, as a valuable alternative to pancreatoduodenectomy even if further and wider studies are necessary in order to obtain an accurate definition of the correct pre-surgical diagnostic approach and surgical indications.