Plasma Reactivity and Plasma-Surface Interactions During Treatment of Toluene by a Dielectric Barrier Discharge

Toluene removal is investigated in filamentary plasmas produced in N₂ and in N₂/O₂ mixtures by a pulse high voltage energised DBD. Influence of the oxygen percentage (lower than 10%) and of the temperature (lower than 350°C) is examined. Toluene is removed in N₂ through collisions with electrons and nitrogen excited states. The removal efficiency is a few higher in N₂/O₂. It increases when the temperature increases for N₂ and N₂/O₂. Both H- and O-atoms play an important role in toluene removal because H can readily recombine with O to form OH, which is much more reactive with toluene than O. H follows from dissociation of toluene and of hydrogenated by-products by electron collisions. Detection of cyanhidric acid, acetylene, formaldehyde, and methyl nitrate strengthens that dissociation processes, to produce H and CH₃, must be taken into account in kinetic analysis. Formation and treatment of deposits are also analysed.     

Homopolymers and vinyl chloride copolymers of vinyl esters of chlorinated fatty acids from umbelliferae and limnanthes douglasii

Homopolymers and copolymers of vinyl esters of chlorinated C₁₈, C₂₀, and C₂₂ fatty acids with vinyl chloride have been prepared and evaluated. The incorporation of the vinyl ester of chlorinated C₁₈, C₂₀, and C₂₂ acids as comonomers with vinyl chloride produced more flexible copolymers than have other comonomers, yet none have imparted the plasticization that can be obtained by an equal amount of external plasticizer.     

Optimal fleet composition and periodic routing of offshore supply vessels

The supply vessel planning problem is a maritime transportation problem faced by amongst others the energy company Statoil. A set of offshore installations requires supplies from an onshore supply depot on a regular basis, a service performed by a fleet of offshore supply vessels. The problem consists of determining the optimal fleet composition of offshore supply vessels and their corresponding weekly voyages and schedules. We present a voyage-based solution method for the supply vessel planning problem. A computational study shows how the solution method can be used to solve real-life problems. Statoil has implemented a planning tool based on the voyage-based solution method and reports significant savings.     

Simultaneous quantification of reduced and oxidized glutathione in plasma using a two-dimensional chromatographic system with parallel porous graphitized carbon columns coupled with fluorescence and coulometric electrochemical detection

A method for the simultaneous quantification of reduced and oxidized glutathione in human plasma employing a two-dimensional chromatographic system with parallel porous graphitized carbon (PGC) columns coupled with fluorescence (FLD) and coulometric electrochemical detection (ED) has been developed. Post-sampling oxidation of reduced glutathione (GSH) was prevented by derivatizing the -SH group with monobromobimane (MBB) and the glutathione-bimane adduct (GSMB) was detected by FLD. Oxidized glutathione (GSSG) was detected by ED optimized to give lowest possible limits of detection (LOD). The method is fully validated and is currently used for determination of GSH, GSSG and its redox potential in different clinical studies.     

A quartz crystal microbalance study of the adsorption of quaternary ammonium derivates on iron and cementite

The adsorption of alkyl trimethyl ammonium bromide with alkyl groups from C₁₀ to C₁₆ onto solid surfaces (iron and cementite (Fe₃C)) is investigated with and without NaCl. For the first time the adsorption of these surface active compounds onto model carbon steel compounds are measured directly by the use of a quartz crystal microbalance (QCM). The adsorption increases steeply around the critical micelle concentration (cmc) in bulk which was also determined for the homologous series. The adsorption of the higher homologues shows rather rigid surface structures while a detailed interpretation of the isotherms for the lowest homologues is disturbed by high bulk viscosities. Based on the obtained results, and in comparison with similar adsorbents on hydrophilic oxide surfaces, it is concluded that the surfactant is adsorbed patchwise in similar structures as in bulk. Finally, the possibilities for close-packing of the surfactant film are discussed.     

Total synthesis of anithiactins A-C and thiasporine A

The total syntheses of anithiactins A-C (1–3) and thiasporine A (4) have been achieved in good overall yields. The key reaction in the synthetic sequence was the Suzuki-Miyaura cross-coupling between 2-aminophenylboronic acid hydrochloride and methyl 2-bromothiazole-4-carboxylate forming the common intermediate methyl 2-(2-aminophenyl)thiazole-4-carboxylate (8), which could be further transformed by hydrolysis, alkylation, and aminolysis to give the four title natural products. This work represents the first total synthesis of anithiactin B (2) and C (3).     

LC�CMS�CMS Determination of Gizzerosine in Poultry Feed

A new selective method for the determination of the bioactive amine gizzerosine in poultry feed is presented based on hydrophilic interaction chromatography coupled to electrospray ionisation and tandem quadrupole mass spectrometry. The protonated molecular ions were selected for fragmentation and scanning of the two major product ions using the mass analyser in the multiple reaction monitoring mode. The analytical methodology included acid hydrolysis of feed sample aliquots and desalting and crude clean-up of hydrolysates using cation-exchange chromatography on a polymeric solid-phase extraction sorbent. Mean overall recoveries (n = 9) were 68?C82% in spike-recovery experiments. The limit of detection was 0.25 mg kg^?1. The method was applied to the analysis of fish meal and fish meal-containing poultry feed samples. Although gizzerosine could not be detected in any of the samples, it was found in fish meal made from sand eel after heating to 130 °C for 24 h.     

Generation of GW radiation pulses from a VUV free-electron laser operating in the femtosecond regime

Experimental results are presented from vacuum-ultraviolet free-electron laser (FEL) operating in the self-amplified spontaneous emission (SASE) mode. The generation of ultrashort radiation pulses became possible due to specific tailoring of the bunch charge distribution. A complete characterization of the linear and nonlinear modes of the SASE FEL operation was performed. At saturation the FEL produces ultrashort pulses (30-100 fs FWHM) with a peak radiation power in the GW level and with full transverse coherence. The wavelength was tuned in the range of 95-105 nm.     

Amphiphilic Lipopeptide Microparticles as Contrast Agents for Medical Ultrasound Imaging

In this study we investigated the utility of complementary amphiphilic lipopeptides as a new membrane formulation suitable for the preparation of gas‐filled microbubbles. Through primarily ion pairing and hydrophobic interactions we rationalized that the stacking of synthetic lipopeptides into the surface of microbubbles would make bubble suspensions useful as ultrasound contrast agents. By mixing charged lipopeptides in propylene glycol/glycerol solutions in the presence of a perfluorocarbon gas followed by vigorous shaking, microbubble suspensions were formed in good yield with a size distribution spanning the range 1–7 × 10^?6 m. The microbubbles were studied in an in vivo model and provided imaging efficacy comparable with conventional ultrasound contrast agents.

Crude sample (before flotation) of Formulation A analyzed at ×40 magnification. The solid bar indicates 10 × 10^?6 m.