Ionic Liquid-assisted Synthesis of Polyaniline/Gold Nanocomposite and Its Biocatalytic Application

In this report, a novel chemical synthesis of polyaniline/gold nanocomposite is explored using ionic liquid (IL) 1-Butyl-3-methylimidazolium hexafluorophosphate. The direct chemical synthesis of polyaniline/gold nanocomposite was initiated via the spontaneous oxidation of aniline by AuCl₄ ⁻ in IL. A nearly uniform dispersion of polyaniline/Au particles with a diameter of 450 ± 80 nm was produced by this method, which indicates that this method is more suitable for controlling particle dimensions. It was also found that the electrical conductivity of the polyaniline/gold nanocomposite was more than 100 times higher than that of the pure polyaniline nanoparticles. The polyaniline/gold nanocomposite displays superior function in the biocatalytic activation of microperoxidase-11 because of the high surface area of the assembly and the enhanced charge transport properties of the composite material. We also report the possible application of polyaniline/gold nanocomposite as a H₂O₂ biosensor.     

Synthesis and structure of a dimeric scandium bis(μ-methoxy) complex

Reaction of hydrated scandium nitrate with 1,10-phenanthroline (phen) in methanol leads to formation of the unusual dimeric complex [(phen)(NO₃)₂Sc(μ-OMe)₂Sc(NO₃)₂(phen)], in which the scandium centres are eight co-ordinate. The complex features two bridging methoxy ligands, as well as bidentate nitrates and chelating 1,10-phenanthroline ligands.     

Influence of various process conditions on surface finishes induced by the direct metal deposition laser technique on a Ti–6Al–4V alloy

The direct metal deposition (DMD) with laser is a free-form metal deposition process for manufacturing dense pieces, which allows generating a prototype or small series of near net-shape structures. One of the most critical issues is that produced pieces have a deleterious surface finish which systematically requires post machining steps. This problem has never been fully addressed before.The present work describes investigations on the DMD process, using an Yb-YAG disk laser, and a widely used titanium alloy (Ti–6Al–4V) to understand the influence of the main process parameters on the surface finish quality. The focus of our work was: (1) to understand the physical mechanisms responsible for deleterious surface finishes, (2) to propose different experimental solutions for improving surface finish.In order to understand the physical mechanisms responsible for deleterious surface finishes, we have carried out: (1) a precise characterization of the laser beam and the powder stream; (2) a large number of multi-layered walls using different process parameters (P(W), V(m/min), D_m (g/min), Gaussian or uniform beam distribution); (3) a real time fast camera analysis of melt pool dynamics and melt-pool – powder stream coupling; (4) a characterization of wall morphologies versus process parameters using 2D and 3D profilometry.The results confirm that surface degradation depends on two distinct aspects: the sticking of non-melted or partially melted particles on the free surfaces, and the formation of menisci with more or less pronounced curvature radii. Among other aspects, a reduction of layer thickness and an increase of melt-pool volumes to favor re-melting processes are shown to have a beneficial effect on roughness parameters. Last, a simple analytical model was proposed to correlate melt-pool geometries to resulting surface finishes.     

Ultraviolet lithography on sloped surfaces utilizing diamond turned holograms

A lithography method by means of a diamond turned hologram (DTH) is presented, that allows patterning of sloped surfaces. The DTH is manufactured by a modified diamond turning process, using a piezoelectric actuator, the nano fast tool servo, which modulates the depth of cut within submicrometer range at a frequency up to 10 kHz. In order to machine a DTH to be applied as phase masks for ultraviolet lithography, workpiece materials have to feature a sufficient reflectivity and excellent machinability. Ultra-fine grained aluminium was identified as most suitable workpiece material, since its reflectivity measures around 80 % and a homogenous structure can be machined. The employed DTH is used in a lithography setup in conjunction with a helium cadmium laser emitting at a wavelength of λ = 325 nm. Patterns up to a linewidth of 30 μm were successfully and consistently transferred on a photoresist coated planar substrate with a tilt angle of 30° with respect to the optical axis.     

Exposure assessment of carcass disposal options in the event of a notifiable exotic animal disease: application to avian influenza virus

We present a generalized exposure assessment of 28 disposal options for poultry carcasses in the event of a highly pathogenic avian influenza (HPAI) outbreak. The analysis supports a hereto unverified disposal hierarchy for animal carcasses, placing waste processing (e.g., incineration and rendering) above controlled disposal (e.g., landfill), above uncontrolled disposal (e.g., burial on-farm). We illustrate that early stages of the disposal chain (on-farm) pose greater opportunities for exposure to hazardous agents than later stages, where agents are generally contained, wastes are treated, and residues are managed by regulated processes. In selecting carcass disposal options, practitioners are advised to consider the full range of hazards rather than focusing solely on the HPAI agent, and to give preference to technologies that (i) offer high destruction efficiencies for target pathogens; (ii) do not give rise to significant releases of other pathogenic organisms; and (iii) do not release unacceptable concentrations of toxic chemicals. The approach offers an exposure assessment perspective for carcass disposal, thus providing a risk-informed basis for contingency planning and operational intervention. The authors recognize that relevant legislation, public perception, available capacity, and cost also need to be considered when selecting disposal options in the event of HPAI.     

Oil price,biofuels and food supply

The price of oil could play a significant role in influencing the expansion of biofuels, but this issue has yet to be fully investigated in the literature. Using a global computable general equilibrium (CGE) model, this study analyzes the impact of oil price on biofuel expansion, and subsequently, on food supply. The study shows that a 65% increase in oil price in 2020 from the 2009 level would increase the global biofuel penetration to 5.4% in 2020 from 2.4% in 2009. If oil prices rise 150% from their 2009 levels by 2020, the resulting penetration of biofuels would be 9%, which is higher than that would be caused by current mandates and targets introduced in more than forty countries around the world. The study also shows that aggregate agricultural output drops due to an oil price increase, but the drop is small in major biofuel producing countries as the expansion of biofuels would partially offset the negative impacts of the oil price increase on agricultural outputs. An increase in oil price would reduce global food supply through direct impacts as well as through the diversion of food commodities and cropland towards the production of biofuels.     

Influence of oxygen on the sputtering of aluminum oxide for the surface passivation of crystalline silicon

While sputtering has been shown to be capable of depositing aluminum oxide suitable for surface passivation, the mechanisms for this are yet to be firmly established and its potential realized. In this paper, we investigate the relationships between the oxygen in the sputtering process to the resulting composition of the deposited film and the surface passivation obtained. We find that surface passivation is not strongly dependent on the bulk composition of the film. Instead the results indicate that the interfacial silicon oxide layer that forms after annealing between the aluminum oxide film and the silicon is a much more important factor; it is this combined structure of aluminum oxide, silicon oxide and silicon that is crucial for obtaining negative charges and excellent surface passivation.     

DIBSOLUTION OF SOLID BOBCAN ASPHALTENES IN MIXED SOLVENTS.

ABSTRACT

Solid petroleum asphaltenes have been fractionated according to solubility in toluene/n-heptane mixtures of increasing toluene content. A large hysteresis was observed between this dissolution and the precipitation from the crude oil. In order to shed light on the solution mechanism, the fractions obtained have been analyzed using size exclusion chromatography (SEC-HPLC-UV-vis), VPO, elemental analysis, UV-vis adsorption spectroscopy and phenol interaction values and methylene content by FTir. Less polar non-associating low molecular weight species are dissolved and a specific extraction of porphyrins is observed. An increased association in the insolubles is indicated. More basic interaction sites are available on the asphaltenes in both fractions relative to the native asphaltene. From the SEC chromatograms it was seen that the soluble fractions did not associate as the insoluble fractions even when making up more than 60 % of the total asphaltenes.     

COMPOSITIONAL ANALYSIS OF NORTH SEA OILS

ABSTRACT

The molar fluid composition of either the reservoir fluid or the well stream is determined by combining the true boiling point (TBP’) distillation data with gas chromatographic (GC) analysis of the light ends. For the purpose of thermodynamic simulation of phase behavior of petroleum reservoir fluids, in addition to the compositional data, physical properties of the pseudo fractions, i.e. density and molecular weight are required. A major drawback of the TBP distillation is the fact that the fractions contain typically 20 -30 % of the material outside the defined boiling range. Another significant issue is the use of generalized density and molecular weight data in the absence of experimentally determined values. This can introduce major inaccuracies in the phase behavior calculations because the generalized value of density and molecular weight significantly differ in each oil based on the paraffin-naphthene-aromatic distribution and its geographic origin.

In this work we have performed the true TBP distillation of 7 stabilized North Sea oil samples. All the oils were distilled from carbon number 6 to 19 and the distillation was terminated at C₂₀₊, which was termed as the residue. We have performed analysis of the Cm fraction of each oil by gas chromatography. Subsequently, the specific gravity and molecular weights of the TBP fractions were determined and compared with the generalized values, which indicated major differences. In addition, the superiority of the PVT calculations for a volatile oil and a gas condensate using the experimentally determined specific gravity and molecular weight of the pseudo fractions against the generalized properties is also demonstrated.     

Zur Methodik der Linientaxation bei der Erhebung von Sch?lereignissen

Zusammenfassung Zwischen 1995–1997 wurden im Rotwildgebiet Nord- und Rureifel, Nordrhein-Westfalen, 124 Schälaufnahmen nach der Methode der Linientaxation durchgeführt (Tab. 3). Die Untersuchung zeigt anhand von ca. 150.000 ausgezählten Stämmen eine Methodenoptimierung zur Schälerhebung auf. Von wesentlicher Bedeutung ist eine ausreichend große Stichprobenzahl an Stämmen im schälgefährdeten Bestand (Tab. 1). Es hat sich als hinreichend erwiesen, je Aufnahmefläche 1.000 Stämme in zehn 100-Stamm-Reihen auszuzählen (Abb. 1). Die durchschnittliche Zeitdauer einer Schälaufnahme mit Anfahrtsweg von Bestand zu Bestand und kurzer Vor- und Nachbereitung der Aufnahme, von einer Person durchgeführt, beträgt etwa 3 Stunden, maximal 4 Stunden. Um das Schälereignis möglichst vollständig zu erfassen, erfolgte die Schälaufnahme der Buche im August und die der Fichte Mitte September. Die Datenreihen wurden mittels Binomialverteilung auf eine ausreichende Genauigkeit in der Ermittlung des Schälprozentes statistisch überprüft (Tab. 4 und 5). Im Vergleich der bundesweit aktuell sieben verschiedenen Länder-Verfahren der forstwirtschaftlichen Schälschadenserhebung bringt die Linientaxation gegenüber den Stichprobenverfahren nach dem System der Klumpenstichproben den wesentlichen Vorteil eines hohen Stichprobenumfanges mit einer entsprechend hohen Genauigkeit des ermittelten Schälprozentes. Zudem entfällt die zeitaufwendige Suche und Identifizierung der einzelnen Anlaufpunkte in den Probekreisen.

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On the method of line taxation for determining amounts of bark stripping

Summary Between 1995 – 1997 the method of line taxation was used to survey 124 samples of bark stripping damage incurred in the red deer districts of North and Ruhreifel, Northrhine Westfalia (Tab.3). On the basis of 150000 counted trunks this investigation showed an optimal method for the determination of bark stripping. Of paramount importance here is a sufficiently large sample size of trunks in bark stripping prone stands (Tab.1). The inclusion of 1000 trunks in 10 100 trunk rows per sample plot suffices (Fig.1) The average sampling time including driving time from stand to stand and brief preparation time before and after sampling is about 3 hours, maximally 4 hours for one person. In order to determine the amount of bark stripping as completely as possible, beech stands were sampled in August and spruce in mid-September. The data were statistically tested using a binomial distribution to provide sufficient accuracy in the determination of percent stripping (Tabs. 4 and 5). In comparing the present various methods for the determination of bark stripping damage to line taxation, this method has the clear advantage of a high degree of precision in determining percent bark stripping and large sample size in comparison to spot sampling. In addition the time consuming search for the individual sample plots in the selected sample areas can be circumvented.

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A propos de l'estimation linéaire lors des relevés d'écorcements importants

Résumé De 1995 à 1997, 124 relevés d'écorcement ont été effectués dans les territoires à Cerf du Nordeifel et du Rureifel en Rhénanie-Westphalie au moyen de la méthode d'estimation linéaire (Tabl. 3). L'étude montre, sur base d'environ 150.000 arbres dénombrés, une optimisation de la méthode d'estimation des écorcements. Il est déterminant de disposer d'un échantillon suffisamment important d'arbres susceptibles d'être écorcés (Tabl. 1). Il s'est avéré suffisant de relever 1.000 pieds sur 100 rangées d'arbres par parcelle (Fig. 1). La durée moyenne du relevé pour une personne, en tenant compte des déplacements de parcelle à parcelle et d'un temps nécessaire avant et après le relevé, est de 3 à maximum 4 heures. Afin de procéder à un relevé aussi exhaustif que possible, les relevés d'écorcement du Hêtre ont lieu en août et ceux de l'Epicéa mi-septembre. Les séries de données ont été statistiquement vérifiées, en ce qui concerne la précision des relevés, au moyen d'une répartition binomiale (Tabl. 4 et 5). Comparée aux 6 différentes méthodes appliquées dans les différents Länder pour le relevé des dégâts d'écorcement, la méthode d'estimation linéaire présente l'avantage important, par rapport à la méthode par échantillonnage par blocs aléatoires, d'un échantillonnage important auquel correspond une précision élevée de la proportion des arbres écorcés. En outre, on fait l'économie de la recherche et de l'identification, exigeantes en temps, des différents points d'intersection du maillage où se situent les placettes de référence.

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Eingesetzt wurde ein Druckkostenzuschuß der LÖBF/LAfAO NRW, Dezernat Forschungsstelle für Jagdkunde und Wildschadenverhütung, für dessen Gewährung verbindlich gedankt wird. — Die Schriftleitung