Rising prices for fossil fuels as well as the increasing effects of the climate change due to the emission of greenhouse gases reveal the necessity of saving energy.Low friction coatings have an enormous potential in saving energy. Carbon based coatings - named as DLC coatings - are especially well suited for low friction coatings. In particular hydrogen-free tetrahedral amorphous carbon (ta-C) coatings are of great interest due to their extraordinary low wear properties. In addition they show excellent low friction properties and especially in combination with specific lubricants the so-called super low friction effect.For the deposition of ta-C coatings PVD methods have to be applied instead of CVD methods as it is the case for conventional DLC coatings. We have developed a deposition method which is based on a pulsed arc steered by a laser (Laser-Arc). This allows us to use large cathodes resulting in a high long-term stability. Furthermore, the carbon plasma source can be combined with a filtering unit removing almost all droplets and particles, which usually are characteristic for an arc process. The resultingLaser-Arc source allows for the deposition of smooth and virtually defect-free ta-C coatings with a competitive deposition rate.

The performances of 2 official methods for iodine analysis based on inductively coupled plasma-mass spectrometry (ICP-MS) and the ion-selective electrode (ISE) method were compared for milk-based products. The aim of the study was to determine the performance characteristics of both methods to check the labeled concentration of iodine. Good precision was found for both methods with highest relative standard deviation of repeatability (RSD(r)) at 2.3 and 2.7% for ISE and ICP-MS, respectively. Intermediate reproducibility (RSD(iR)), single laboratory within 6 different days, was also good with the highest values at 7.3 and 8% by ISE and ICP-MS, respectively. Measurement uncertainty was estimated based on the RSD(iR) data, and it was concluded that both methods were capable of determining iodine concentrations within an uncertainty below +/- 20%. The accuracy of the methods was determined by analyzing certified reference materials, in-house proficiency test samples, and commercial products. Both methods returned similar results when applied on freshly opened samples. In samples that had been opened and kept exposed to air during storage, ISE returned lower iodine concentrations than ICP-MS. In commercial samples, the linear regression between both methods was ISE = 0.95 x ICP-MS -0.060 for freshly opened samples and ISE = 0.85 x ICP-MS + 0.069 for samples exposed to air. The tendency of ISE to return lower results than ICP-MS is explained by the fact that ISE is sensitive to iodide but does not measure iodine that may be bound organically to the matrix. This seems to be more pronounced in samples that were stored longer. Because in most countries iodine is labeled as total iodine, acceptance of an international standard based on the ICP-MS technique which takes all forms of iodine into account, is recommended. This would help to avoid any potential dispute on the accuracy of labeled iodine concentrations in finished products.

Summary form only given. The COBRA accelerator is a pulsed power generator capable of producing up to 1 MA current pulses. The machine is driven by two 60 kJ Marx generators that feed four parallel pulse-forming lines that are merged into a single wire-array Z-pinch load. A typical pulse rise time is 100 ns and the pulse width is about 200 ns. Time-gated X-ray imaging is an important diagnostic for the study of imploding dense Z-pinches. These rapidly changing plasmas must be studied on the nanosecond time scale, and they generally radiate strongly in the soft X-ray range. As such, they require short, intense X-ray sources to illuminate them. Monochromatic X-ray imaging using an X pinch X-ray source is a way that has been used successfully in the past. On COBRA, X-pinches in return current rods in the Z-pinch load region are used as the time-gated X-ray source. Monochromatic imaging is provided by reflecting X pinch radiation off of a spherically bent mica crystal. Experiments have been performed to investigate X-ray source parameters including source size and X-ray spectrum for various materials and configurations. These results will be the main focus of this presentation

A simple and rapid method for the determination of iron, copper and zinc in food premixes (used during human food processing) by energy dispersive X-ray fluorescence (XRF) has been established and validated using 25 samples. Reference values were obtained by inductively coupled plasma-optical emission spectroscopy after microwave acidic digestions. Studied samples presenting wide ranges of concentrations: Fe=500–35000 mg/kg, Cu=50–4000 mg/kg and Zn=700–32000 mg/kg were quantified in 200 s by XRF measurements using a rhodium tube.

The application of a dynamic reaction cell inductively coupled plasma mass spectrometer (DRC ICP-MS) for interference-free Cr determination was validated for different foods. The working conditions were optimized and the method as such validated using certified reference materials and internal food samples. For the latter, reference data obtained from graphite furnace atomic absorption spectrometry (GFAAS) were used for comparison. Samples were prepared using microwave-assisted acid hydrolysis and high-pressure ashing. Both methods yielded residual carbon that leads to an over-estimation of Cr concentrations when using the ICP-MS in standard mode. The DRC however reduced this interference efficiently making accurate and precise measurements of Cr in routine samples possible. The use of the DRC was especially justified for samples that were prepared by microwave-assisted acid hydrolysis because the interference was most pronounced in those samples.

A method for the multielement analysis of mineral premixes using inductively coupled plasma optical emission spectrometry (ICP-OES) was developed and validated. Due to the lack of certified premix samples, the validation was performed on five different purchased premixes. A microwave-assisted acid hydrolysis was used to bring the elemental composition into solution. A standardized dilution scheme permitted the determination of different ranges of elemental concentrations found in premixes. Calcium, chromium, copper, iron, magnesium, manganese, molybdenum, selenium, and zinc were determined simultaneously by ICP-OES. Robust repeatability and intermediate reproducibility were estimated and found to be sufficient for three out of five premixes. The same was true for accuracy which had been estimated by the determination of recovery from spiked premixes. Insufficient repeatability and accuracy for two pet food premixes was due to their heterogeneity. Using a larger sample size for these premixes significantly improved the repeatability and intermediate reproducibility for several elements. The developed multielement method performed well on homogeneous mineral premixes, but high repeatability data are to be expected from pet food premixes due to their high heterogeneity.