Thermophysical and Microstructural Studies on Thermally Sprayed Tungsten Carbide-Cobalt Coatings

The development of new hardmetal coating applications such as fatigue-loaded parts, structural components, and tools for metal forming is connected with improvement of their performance and reliability. For modelling purposes, the knowledge of thermophysical, mechanical, and other material data is required. However, this information is still missing today. In this study, the thermophysical data of a WC-17Co coating sprayed with a liquid-fuelled HVOF-process from a commercial agglomerated and sintered feedstock powder from room temperature up to 700 °C was determined as an example. The dependence of the heat conductivity on temperature was obtained through measurement of the coefficient of thermal expansion, the specific heat capacity, and the thermal diffusivity. Heat conductivities ranging from 29.2 W/(mK) at 50 °C to 35.4 W/(mK) at 700 °C were determined. All measurements were performed twice (as-sprayed and after the first thermal cycle) to take into account the structural and compositional changes. Extensive XRD and FESEM studies were performed to characterize the phase compositions and microstructures in the as-sprayed and heat-treated states. Bulk samples obtained by spark plasma sintering from the feedstock powder were studied for comparison.     

Case specific prediction intervals for tri-PLS1: The full local linearisation

A new method to estimate case specific prediction uncertainty for univariate trilinear partial least squares (tri-PLS1) regression is introduced. This method is, from a theoretical point of view, the most exact finite sample approximation to true prediction uncertainty that has been reported up till now. Using the new method, different error sources can be propagated, which is an advantage that cannot be offered by data driven approaches such as the bootstrap. In a concise example, it is illustrated how the method can be applied. In the Appendix, efficient algorithms are presented to compute the estimates required.     

Consumer preferences and willingness to pay for value-added chicken product attributes

A growing demand for convenient and ready-to-eat products has increased poultry processors' interest in developing consumer-oriented value-added chicken products. In this study, a conjoint analysis survey of 276 chicken consumers in Edmonton was conducted during the summer of 2009 to assess the importance of the chicken part, production method, processing method, storage method, the presence of added flavor, and cooking method on consumer preferences for different value-added chicken product attributes. Estimates of consumer willingness to pay (WTP) premium prices for different combinations of value-added chicken attributes were also determined. Participants'"ideal" chicken product was a refrigerated product made with free-range chicken breast, produced with no additives or preservatives and no added flavor, which could be oven heated or pan heated. Half of all participants on average were willing to pay 30% more for a value-added chicken product over the price of a conventional product. Overall, young consumers, individuals who shop at Farmers' Markets and those who prefer free-range or organic products were more likely to pay a premium for value-added chicken products. As expected, consumers' WTP was affected negatively by product price. Combined knowledge of consumer product attribute preferences and consumer WTP for value-added chicken products can help the poultry industry design innovative value-added chicken products. Practical Application: An optimum combination of product attributes desired by consumers for the development of a new value-added chicken product, as well as the WTP for this product, have been identified in this study. This information is relevant to the poultry industry to enhance consumer satisfaction of future value-added chicken products and provide the tools for future profit growth.     

Long-term greenhouse gas emission reductions—what's possible,what's necessary?

Climate is changing (WMO, Press release No. 695, 2003) and there is increasing evidence that this is due to human activity (IPCC, Climate Change 2001—The Scientific Basis, Cambridge University Press, Cambridge, 2001). One way to react is to reduce greenhouse gas emissions into the atmosphere. Although this approach generally does not cause much objection, disagreements do occur when concrete emission targets are to be set. Against this background, the following article provides an arithmetic approach for the determination of long-term emission targets where the US and the EU are studied as examples.     

Alcohol, psychoactive drugs and fatal road traffic accidents in Norway: a case-control study

A case–control study was conducted on 204 drivers fatally injured in road traffic accidents in south-eastern Norway during the period 2003–2008. Cases from single vehicle accidents (N = 68) were assessed separately. As controls, 10 540 drivers selected in a roadside survey in the same geographical area during 2005–2006 were used. Blood samples were collected from the cases and oral fluid (saliva) samples from the controls. Samples were analysed for alcohol, amphetamines, cannabis, cocaine, opioid analgesics, hypnotics, sedatives and a muscle relaxant; altogether 22 psychoactive substances. Equivalent cutoff concentrations for blood and oral fluid were used. The risk for fatal injury in a road traffic accident was estimated using logistic regression adjusting for gender, age, season of the year, and time of the week. The odds for involvement in fatal road traffic accidents for different substances or combination of substances were in increasing order: single drug < multiple drugs < alcohol only < alcohol + drugs. For single substance use: medicinal drug or THC < amphetamine/methamphetamine < alcohol. For most substances, higher ORs were found when studying drivers involved in single vehicle accidents than for those involved in multiple vehicle accidents, but confidence intervals were wider.     

Luminescence properties of monoclinic Cu4I4(Piperidine)4

A new modification of Cu₄I₄Pip₄ has been synthesized under hydrothermal conditions. X-ray crystallography revealed that this compound crystallized in the monoclinic system and consists of a tetrahedral core with composition Cu₄I₄, in which each Cu atom is coordinated by a piperidine molecule via the N atom. In contrast to a previously reported modification of Cu₄I₄Pip₄, the present modification shows luminescent properties when exposed to UV-light. In addition, we have used time-dependent density functional theory calculations to characterize both compounds in term of both absorption and emission.     

Substrate- and oxidation-induced roughness of individual terraces of pentacene thin films

The roughness at the surface of individual pentacene terraces on naturally oxidized silicon wafers was investigated with scanning force microscopy as function of film thickness (one to five layers) and sample exposure to ambient air. For pristine samples, the root-mean-square roughness on individual (001) pentacene terraces was 0.18 nm and varied by less than 0.02 nm between monolayer terraces and terraces in the fifth layer. Storing samples in air and ambient light led to a substantial increase of the roughness, which for terraces up to the third layer became 0.24 nm after four weeks. For fourth layer terraces, the roughness increased less, and terraces in the fifth layer exhibited no significant roughness increase. We explain the roughness increase by photo-oxidation of pentacene, particularly strong within the first layer, which is supported by the appearance of grain boundary widening with storage time. The observation that layers beyond the third one from the substrate are less affected by photo-oxidation (smaller terrace roughness) is likely due to better structural perfection in layers farther from the substrate, which reduces the effective cross-section of molecules for oxidation. These results indicate that native silicon oxide does not allow for the immediate formation of structurally perfect pentacene films in the range of one to three layers, which will reduce charge carrier mobility in pentacene thin film transistors. Thicker pentacene layers can protect underlying layers against oxidation.     

Sicherheitskonzepte für den Datenschutz

Der Erstellung und Pflege von Sicherheitskonzepten wird häufig zuwenig Wichtigkeit beigemessen. Im vorliegenden Beitrag beleuchtet der Autor Motivation, Anforderungen und Erfolgsfaktoren bei der Erstellung eines guten Sicherheitskonzepts.