Non-Destructive In Situ Analysis of Interface Processes and Thin Film Growth

Optical second harmonic generation (SHG) was applied to monitor the growth of films of polyamic acid on polycrystalline gold substrates. Different diamines such as 4,4'-oxydianiline (ODA), 4,4'-diaminodiphenyl disulfide (DAPS) and 4,4'-diaminobiphenyl (benzidine) were codeposited from the gas phase with pyromel-litic dianhydride (PMDA). Depending on the diamine, the second harmonic signal varies differently during formation of the polymer/metal interface and the subsequent film growth. A three-layer model which takes into account the optical properties of thin films reveals that the shape of the thickness-dependent SH signal is related to the orientation of the molecules in the film. A fit of the experimental data based on the model indicates a structural transition that occurs several tens of nanometers above the substrate for PMDA/ODA and PMDA/DAPS. The experiments demonstrate that SHG can be applied to monitor the growth of thin films and to extract structural information.     

Rice Slurry Analysis Using Mixed-Gas Plasma and Axially Viewed ICP OES

This study deals with determination of essential and toxic elements in slurry of rice using axially viewed inductively coupled plasma optical emission spectrometry (ICP OES) and mixed gas plasma (N₂-Ar ICP). Nitrogen was added (flow rate of 20 mL min^?1) to the nebulizer gas through the spray chamber. It was observed that the addition of N₂ increased the ICP robustness and mitigated the slurry matrix effects. Several parameters associated with the slurry preparation (extractant concentration, dispersant concentration, mass volume ratio of the slurry and sonication) were evaluated. The slurry was prepared in 10 % (m/v) HNO₃?+?0.2 % (m/v) Triton X-100. Calibration was carried out with aqueous standards whereas Y(II) (371.029 nm) was used as internal standard (IS) in order to overcome matrix effects. The IS and sample solutions were mixed online. Accuracy was evaluated by the analysis of certified reference materials and by comparison with an independent method of sample preparation (acid digestion). The concentrations were consistent with those certified or found in digested rice sample. Calcium, Mg, K, Cd Cu, Fe, Mn, Mo, Cr, Zn, Co, Pb and Ni were investigated whose limits of detections were 0.080, 0.033, 0.050, 0.048, 0.050, 0.015, 0.005, 0.107, 0.036, 0.056, 0.040, 0.367 and 0.132 mg kg^?1, respectively. The RSD (relative standard deviation) was typically lower than 10 %. Samples of parboiled, white, and brown rice were analysed and the concentrations found corroborate with those reported. It was concluded that calibration with aqueous standard is feasible, making the analysis simpler. The method is robust and can be routinely applied.     

Effects of total iron, myoglobin, hemoglobin, and lipid oxidation of uncooked muscles on livery flavor development and volatiles of cooked beef steaks

Infraspinatus (IN), gluteus medius (GM), and psoas major (PM) steaks were obtained from A- and B-maturity carcasses with either high (6.0) or normal (5.7) pH, and either Slight or Small marbling. Steaks were vacuum aged either 7, 14, 21, or 35 d postmortem, and were broiled and served to a highly trained, flavor-profile sensory panel. Steaks with livery flavor were analyzed by gas chromatography/mass spectrometry for flavor compounds. Steaks aged 7 or 35 d postmortem were analyzed for myoglobin (Mb) and hemoglobin (Hb) concentrations and for total iron (Fe) (35 d steaks only). The IN had greater Fe (P < 0.05) than did the GM or PM. Livery flavor increased (P < 0.05) and beef flavor identification decreased (P < 0.05) in the GM as Fe increased. The PM had the lowest (P < 0.05) Mb/Fe ratios and highest (P < 0.05) Hb/Fe ratios. Several statistically significant, but relatively low correlations between 16-, 17-, and 18-carbon chain fatty acids and livery flavor resulted. Thirteen volatile compounds had higher concentrations in steaks with livery flavor than in those without livery flavor. Livery flavor development is a complex trait that can be affected by concentrations of total Fe, Mb, and fatty acids, but the relationships are relatively low.     

Arsenic speciation in white wine by LC–ICP–MS

This study deals with As speciation in white wine. Arsenic species were selectively determined by liquid chromatography–inductively coupled plasma–mass spectrometry (LC–ICP–MS). Separation of As species was performed using an anion exchange column with ammonium phosphate solution (pH 6.00) as mobile phase. Samples of 14 white wine produced in South America were analysed. They were 10-fold diluted in the mobile phase prior to analysis by LC–ICP–MS. Accuracy was evaluated by recovery tests, whereas As species recovery ranged from 95% to 106%. Additionally, the sum of arsenic species concentration found by LC–ICP–MS was in agreement with the total arsenic concentration determined by ICP–MS after sample digestion. Arsenic species detected were arsenite [As(III)], arsenate [As(V)] and dimethylarsinic acid (DMA). As(III) and As(V) were detected in all analysed wine samples and DMA was detected only in wines produced in Argentina. Results for As determination in samples were from 2.9 to 10.3, 8.6 to 17.8, and <0.45 to 1.07 μg L⁻¹ for As(III), As(V) and DMA, respectively.     

Alkarenesulphonates from Fischer-Tropsch waxes and their evaluation as anti-stresscracking agents in polyethylene

Fischer-Tropsch waxes were converted into alkarenesulphonates by successive chlorination, phenylation and sulphonation. The sulphonates showed high efficacy as anti-stresscracking agents in low-density polyethylene.     

PROGRESS IN THE ELIMINATION OF SAGGERS IN THE FIRING OF GLOST AND BISQUE GENERAL WARE AND GLOST WALL TILE1

During the past fourteen years the use of saggers has been largely eliminated in the sanitary ware industry by the use of cars equipped with permanent superstructures of slabs and posts in muffle tunnel kilns. Methods are described by which saggers can be eliminated for firing general ware and wall tiles with correspondinn benefits.     

Screening of pharmaceuticals and drugs in synovial fluid of the knee joint and in vitreous humor by fluorescence polarization immunoassay (FPIA)

The investigations presented are aimed at testing whether ABBOTT's fluorescence polarization immunoassays for identification of drugs of abuse and pharmaceuticals in serum and urine are applicable to knee joint synovial fluid and vitreous humor. The survey confirms the general applicability of the tests to the respective body fluids without previous precipitation, only after liquefaction using hyaluronidase. The calculated cross-reactivities are shown in tables.     

Simulation of Ad Hoc Routing Protocols using OMNeT++

Mobile Ad Hoc Networks (MANETs) have evolved in the last years into standards in the communication world. By definition, they do not need any network infrastructure to facilitate communication between participating nodes. Therefore, MANETs are dealing with new challenges in the context of ad hoc routing. Simulation techniques are one of the fundamental methodologies to support the protocol engineering process, especially in the early stages of ad hoc network protocol design. In this paper, we set out common criteria that may serve as guidelines for meaningful simulative evaluations of ad hoc routing protocols. We present typical and necessary measures for ad hoc routing in general and MANET routing in particular. As a case study, we demonstrate a comprehensive performance evaluation of the Dynamic MANET On Demand (DYMO) routing protocol using a model we implemented for the popular OMNeT+ + discrete event simulation environment.