Quantized representation of some nonlinear integrable evolution equations on the soliton sector

The Hirota algorithm for solving several integrable nonlinear evolution equations is suggestive of a simple quantized representation of these equations and their soliton solutions over a Fock space of bosons or of fermions. The classical nonlinear wave equation becomes a nonlinear equation for an operator. The solution of this equation is constructed through the operator analog of the Hirota transformation. The classical N-solitons solution is the expectation value of the solution operator in an N-particle state in the Fock space.Comment: 12 page

Anodising AA5083 aluminium alloy using ionic liquids

Aluminium, as the current collector in lithium batteries, has shown reduced corrosion susceptibility in room temperature molten salts (1, 2). Moreover, previous studies have established that corrosion mitigation is achieved on magnesium alloys using ionic liquids pretreatments (3, 4). This paper investigated the anodisation of AA5083 aluminium alloy in Trihexyl(tetradecyl)phosphonium bis(trifluoromethylsulfony) ([P6,6,6,14][NTf2]) ionic liquid by applying a constant current followed by holding at the maximum potential for a period of time. Potentiodynamic polarisation results show that the treated surfaces were more corrosion resistant in 0.1 M sodium chloride solution compared with the control specimen. The anodising treatment was effective both in shifting the free corrosion potential to more noble values and in suppressing the corrosion current. Optical microscope and optical profilometry images indicated that an anodising film was deposited onto the alloy surface, which is thought to have inhibited corrosion in chloride environment. Further characterisation of the anodising film will be carried out in future work

Presencia de minerales poco comunes en la roca alterada de un edificio medieval escocés colonizado por organismos biológicos

During the course of a study of biodeterioration at Hermitage Castle in the Scottish Borders various rare minerals: monohydrocalcite, nesquehonite and dypingite were found in association with the biological growths. Monohydrocalcite was found particularly in association with a green alga "Trentepohlia aurea". A brief review of previous publications concerning these minerals is given and the theory put forward with regard to the possible origin of the monohydrocalcite as a biogenic by product.En el transcurso de un estudio sobre el biodeterioro existente en el 'Hermitage Castle', localizado en los 'Scottish Borders' (frontera entre Escocia e Inglaterra), se detectó la presencia de monohidrocalcita, nesquehonita y dipingita, minerales considerados como poco frecuentes, asociados con la colonización biológica presente, especialmente en el caso de la monohidrocalcita y el alga verde Trentepohlia áurea. En este trabajo se presenta una revisión bibliográfica sobre estos minerales así como la teoría del posible origen biogénico de la monohidrocalcita

The effect of (Ti + Al): V ratio on the structure and oxidation behaviour of TiAlN/VN nano-scale multilayer coatings

Nano-scaled multilayered TiAlN/VN coatings have been grown on stainless steel and M2 high speed steel substrates at U-B = - 85 V in an industrial, four target, Hauzer HTC 1000 coater using combined cathodic steered arc etching/unbalanced magnetron sputtering. X-ray diffraction (XRD) has been used to investigate the effects of process parameters (Target Power) on texture evolution (using texture parameter T*), development of residual stress (sin(2) psi method) and nano-scale multilayer period. The composition of the coating was determined using energy dispersive X-ray analysis. The thermal behaviour of the coatings in air was studied using thermo-gravimetric analysis, XRD and scanning electron microscopy. The bi-layer period varied between 2.8 and 3.1 nm and in all cases a {1 1 0} texture developed with a maximum value T* = 4.9. The residual stress varied between -5.2 and -7.4 GPa. The onset of rapid oxidation occurred between 628 and 645 degreesC depending on the (Ti+Al):V ratio. After oxidation in air at 550 degreesC AlVO4, TiO2 and V2O5 Phases were identified by XRD with the AlVO4, TiO2 being the major phases. The formation of AlVO4 appears to disrupt the formation of Al2O3 which imparts oxidation resistance to TiAlN based coatings. Increasing the temperature to 600 and 640 degreesC led to a dramatic increase in the formation of V2O5 which was highly oriented (0 0 1) with a plate-like morphology. At 640 degreesC there was no evidence of the coating on XRD. Increasing the temperature to 670 degreesC led to further formation of AlVO4 and a dramatic reduction in V2O5. (C) 2003 Elsevier B.V. All rights reserved

Studying the cathodic disbondment of coatings using electrochemical impedance spectroscopy

The disbondment of protective organic coatings is a widely reported pipeline coating failure mode in the oil and gas industry. Traditional methods of evaluating cathodic disbondment of pipeline coatings are based on visual inspection of pipeline conditions, and laboratory testing of cathodic disbondment resistance (CDR) using standard methods such as ASTM G8. Although some other laboratory-based techniques, such as scanning kelvin probe and scanning acoustic microscopy have been used to study the cathodic disbondment (CD) of coatings, these are often difficult to apply in practical testing. Over the past decade, electrochemical impedance spectroscopy (EIS) has been employed as a potential method for measuring CD. This paper reports preliminary results from an EIS study designed to characterise CD behaviour of epoxy coatings under excessive cathodic protection. EIS data correlated well with the area of disbonded coating. Analysis of EIS data can provide valuable information on the initiation and rates of CD

Evaluating data capture methods for the establishment of diagnostic reference levels in CT scanning

Objective: Concerns about the radiation dose associated with CT scanning have led to a call for establishment of diagnostic reference levels. Self-complete surveys have been used extensively to gather this information, however, departmental Radiological Information System's/Picture Archive Communication Systems (RIS/PACS) also hold this information. We compared dosimetry derived from survey with those using RIS/PACSs.Methods: Technical data were collected from a large metropolitan tertiary hospital in WA using both data collection methods for a range of adult CT scanning examinations. Radiation dose was calculated from both datasets and the results evaluated for several indexes of inter-rater agreement.Results: Radiation dose calculated using self-report survey data differed both systematically and proportionally from that calculated using RIS/PACS data. Differences were not consistent across CT examination type and thus not amenable to simple correction. The disparity was greater and more variable for organ dose than effective dose due to reliance of survey data on “generic” anatomical start and stop limits compared with actual data available on RIS/PACS.Conclusions: The bias observed in our study indicates that care should be taken when interpreting the results of studies measuring radiation dose using self-complete surveys. The availability of electronic databases that include information required for the evaluation and monitoring of CT radiation dose provides the opportunity to capture better quality data in a cost-effective manner. We recommend that national and local databases are established that routinely capture these data so as to facilitate the development and monitoring of radiation dose associated with CT scanning

Wind tunnel investigation of the wake near the trailing edge of a distributed upper-surface-blown flap

An investigation of the flow field near the trailing edge of a distributed upper-surface-blown propulsive-lift transport was conducted in the Langley V/STOL tunnel. This model used blowing slots across the entire wing span to produce a thin jet efflux near the leading edge and at the knee of the flap. Velocity surveys of the flow field were taken near the trailing edge of the model, and are presented as plots of the individual velocity vectors. The test conditions include an angle-of-attack range from 4 deg to 16 deg and a thrust coefficient range from 0 to 1.3 at a free-stream dynamic pressure of 814 Newton per square meter (17 pounds per square foot)