The influence of Si on precipitation phenomena and age hardening of a beta Ti alloy

The phase transformations occurring in a quenched and aged β-phase (bcc) Ti-40 at. pct V+1 at. pct Si alloy have been investigated using transmission electron microscopy. Upon aging at 570°C, the most probable precipitation sequence is the following: bcc super-saturated solid solution»bcc zones»(Ti, V)_xSi_y (hexagonal)»(Ti, V)₃Si (tetragonal). The bcc precipitates may be considered Si-rich GP zones which are homogeneously nucleated and coherent with the matrix. The (Ti, V)_xSi_y particles are a rod-shaped transition phase aligned along the <100> matrix directions. The precipitation reaction causes two peaks in the dependence of the yield stress or hardness upon aging time. The particle diameter and interparticle spacings of the hexagonal silicides indicate that these precipitates are responsible for the second hardness peak. The bcc zones evidently cause the first hardness peak at short aging times at 570°C.     

Which operations can be done without general anesthesia?

The fatty acid composition of erythrocytes, platelets, and serum lipids was compared between subjects who had been eating a strict uncooked vegan diet ("living food") for years and omnivore controls. The vegan diet contains equal amounts of fat but more monounsaturated and polyunsaturated and less saturated fatty acids than the mixed diet of the control group. In vegans, the proportion of linoleic acid was greater in all lipid fractions studied. Also, the levels of other n-6 fatty acids were greater, with the exception of arachidonic acid levels, which were similar in most fractions. In erythrocytes, platelets and serum phospholipid fractions, this increase was mainly at the expense of the n-3 fatty acids. The proportions of eicosapentaenoic and docosahexaenoic acid were only 29-36% and 49-52% of those in controls, respectively. In vegans the ratio of n-3 to n-6 fatty acids was only about half that in omnivores. In addition to the lower levels of n-3 fatty acids, the proportions of palmitic and stearic acids were lower in serum cholesteryl esters, triglycerides and free fatty acids of vegans. The proportion of oleic acid was slightly lower only in serum cholesteryl esters and erythrocyte phosphatidylserine. The results show that, in the long term, the vegan diet has little effect on the proportions of oleic and arachidonic acids, whereas the levels of n-3 fatty acids are depressed to very low levels with prolonged consumption of the high linoleic and oleic acid components of this diet.     

Poly(ε‐caprolactone)‐grafted acetylated anhydroglucose oligomer by ring‐opening polymerization—Synthesis and characterization

A novel acetylated anhydroglucose oligomer (AGU‐oligomer), prepared by acid catalyzed transglycosidation of potato starch triacetate and ethylene glycol, was used as a multifunctional coinitiator for the ring‐opening polymerization of ε‐caprolactone (ε‐CL). The polymers were synthesized using different weight ratios of the starting materials and were characterized by NMR, SEC, and MALLS. The results confirmed the expected P(AGU/CL) polymer structure, namely a ‘comb‐like’ graft‐copolymer having the AGU oligomer as backbone with PCL grafts of variable chain lengths (L_CL = 4–21). Thermal and mechanical properties of graft‐copolymers with different ε‐CL block lengths were examined. By changing the graft length, crystallinity was controlled and amorphous polymers were obtained with AGU‐oligomer contents higher than 50 wt %. The tensile properties varied with the composition and a copolymer having 40 wt % of AGU‐oligomer behaved like soft elastomer, showing high elongation at break. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 1633–1641, 2006     

Polycyclic aromatic compounds (PAC) in leaf lettuce

Summary Twentythree samples of leaf lettuce (Lactuca sativa var.crispa) cultivated in private gardens in southern Finland were analyzed for polycyclic aromatic hydrocarbons (PAH) and derivatives. The total PAH concentrations varied from 4.8 to 94 g/kg fresh weight. Nitro derivatives of PAH were detected in only five samples. One lettuce sample was also analyzed for PAH oxy-derivatives. 9H-Fluoren-9-one (1.3 g/kg) and 6H-benzo[cd]pyren-6-one (0.3 g/kg) were found.The profiles of PAH in lettuce were compared with those in ambient air. It was concluded that PAH in lettuce originate from deposition of PAH-containing particles present in ambient air.

---

Polycyclische aromatische Verbindungen im Pflücksalat

Zusammenfassung 23 Pfüicksalatproben (Lactuca sativa var.crispa) aus südfinnischen Hausgärten wurden auf polycyclische aromatische Kohlenwasserstoffe (PAH) und deren Derivate untersucht. Die Gesamt-PAH-Gehalte variierten zwischen 4,8 und 94 g/kg Frischgewicht. PAH-Nitroabkömmlinge wurden lediglich in fünf Proben festgestellt. Eine der Salatproben wurde auch auf PAH-Sauerstoffdrivate untersucht. An der Probe wurden 9H-Fluoren-9-on (1,3 g/kg) und 6H-Benzo(cd)pyren-6-on (0,3 g/kg) festgestellt.Die PAH-Profile der Salatproben wurden an PAH-Profilen der freien Luft verglichen. Auf diese Weise konnte festgestellt werden, daß die PAH-Verbindungen von PAH-Verbindungen enthaltenden Partikeln der freien Luft stammen.

     

Nanoparticle Deposition from Liquid Flame Spray onto Moving Roll-to-Roll Paperboard Material

Nanostructured coatings have been prepared on a flexible, moving paperboard using deposition of ca. 40-nm-sized titanium dioxide nanoparticles generated by a liquid flame spray process, directly above the paperboard, to achieve improved functional properties for the material. Properties such as surface wettability can be extensively improved by a thin layer of nanoparticles on the substrate. Owing to the vulnerability to heat, the substrate needs to be moved rapidly through the flame. This, on the other hand, generates a setting for a roll-to-roll coating process, which favors upscaling of the method. In this article, we characterize the flame process for nanoparticle coating and quantify the operational window for this method. The amount of deposited material as a function of substrate speed through the flame is discussed. Although the thermophoretic flux of nanoparticles is estimated to be very high from the hot flame onto the cold substrate, other factors were observed to limit the deposited amount of particles. Total mass yields of 5%–20% of the injected precursor material into the titanium dioxide nanocoating on the paperboard were achieved. With these yields, a highly hydrophobic surface was obtained by a mass loading of 10–50 mg/m² of titanium dioxide on the paperboard.     

The Effect of Flame Treatment on Surface Properties and Heat Sealability of Low‐Density Polyethylene Coating

The target of this study is to investigate the correlation between surface properties and heat sealability of flame‐treated low‐density polyethylene (LDPE) coating because it is vital to know how to modify the surface properties of LDPE coating without losing the heat sealing properties. Flame treatment showed a significant effect on the heat sealing properties of LDPE‐coated paper. For example, the heat sealing temperature of LDPE coating decreased or alternatively doubled, depending on the equivalence ratio (air–propane ratio) of flame treatment. In addition, the hot tack strength was significantly enhanced by flame treatment, which broadened the hot tack window of LDPE‐coated paper. The reason for the heat sealing performance of flame‐treated LDPE coating was believed to be related to the simultaneous reactions, that is, cross‐linking and chain scission, occurring on the LDPE surface. The molecular weight of LDPE surface increased or decreased, depending on the dominating reaction during flame treatment. This affected the chain mobility and the amount of chain interdiffusion across the seal interface and finally defined the heat sealing performance of LDPE‐coated paper. Copyright © 2012 John Wiley & Sons, Ltd.     

Characterization of resolution cycle times of corrective actions in mobile terminals

Resolution cycle times for resolving issues raised by customers is one of the essential factors for indication of the customer's satisfaction. The fact that there are many mobile terminals manufacturers implies that competition to grab and hold market share for a sustainable time is very strong. A forecasting model, based on a selected statistical distribution, is built up to give an estimation of the resolution time in three different category products. In this paper the model does not specify different failure symptoms reported by customers. Uncertainties and the reliability of the model buildup are discussed and example of an optimized correction action is given. Copyright © 2008 John Wiley & Sons, Ltd.