Size-dependent dissociation of small cobalt clusters on ultrathin NaCl films

Mass-selected anionic cobalt clusters of two different sizes (Co2 and Co13) were deposited onto ultrathin NaC1 films grown on an Au(111) substrate.Using scanning tunneling microscopy experiments and density functional theory simulations,we show that the deposited Co2 cluster dissociates and that the resulting Co atoms dope the NaCl surface by substituting Na ions.In contrast,the larger Co13 cluster does not dissociate and remains stable on top of the NaC1 film.The sizedependent fragmentation of clusters is an important aspect in the understanding of the chemical interaction between size-selected small aggregates of atoms and supporting surfaces.     

Microstructural Studies of the Interfacial Zone of a SiC-Fiber-Reinforced Lithium Aluminum Silicate Glass-Ceramic

Transmission electron microscopy studies have been conducted on interfaces in a lithium aluminum silicate/SiC-fiberreinforced composite. In the as-processed state, interphases of amorphous C and carbides of Nb have been confirmed, with circumferential thermal debonds evident in the C layer. After heat treatment in air at 800°C, the C is found to be replaced by amorphous SiO₂, and the carbides of Nb replaced by oxides. The SiO₂ thickens with exposure time and typically contains circumferential separations. Some Mg and Al diffusion also accompanies the heat-treatment process and eventually leads to the formation of MgO and Mg silicates in the interfacial zone.     

A possible role of in-flow effects in functional MR-imaging

The potential of functional MR-imaging at 1.5 T was studied using optical stimulation of the human brain. Differences in the image intensity of up to 30% were obtained in the visual cortex area, correlating with the time course of the stimuli. A simplified semi-quantitative model describing the role of in-flow effects in brain vessels on signal increase during the stimulation period is presented.     

Effects of glutaraldehyde or osmium tetroxide fixation on the osmotic properties of lung cells

The osmotic properties of lung cells have been tested before and after perfusion fixation of isolated, perfused lungs with either glutaraldehyde or osmium tetroxide. The testing procedure was to add hypertonic sucrose to the perfusate for several minutes and monitor the lung weight response (an ‘osmotic transient’). Each lung was perfused with one or the other fixative solutions for 10 min, then the perfusate was changed back to Ringer-lactate before the post-fixation test was conducted. The results indicate that osmium tetroxide makes the cell membranes as permeable to sucrose as to water, and that sucrose thus causes no osmotic volume change. Glutaraldehyde, on the other hand, apparently preserves the impermeability of the cell membranes to sucrose, but the osmotic volume response is attenuated, indicating that significant changes in the cells have occurred.     

Coupled Crystal Plasticity–Phase Field Fracture Simulation Study on Damage Evolution Around a Void: Pore Shape Versus Crystallographic Orientation

Various mechanisms such as anisotropic plastic flow, damage nucleation, and crack propagation govern the overall mechanical response of structural materials. Understanding how these mechanisms interact, i.e. if they amplify mutually or compete with each other, is an essential prerequisite for the design of improved alloys. This study shows—by using the free and open source software DAMASK (the Düsseldorf Advanced Material Simulation Kit)—how the coupling of crystal plasticity and phase field fracture methods can increase the understanding of the complex interplay between crystallographic orientation and the geometry of a void. To this end, crack initiation and propagation around an experimentally obtained pore with complex shape is investigated and compared to the situation of a simplified spherical void. Three different crystallographic orientations of the aluminum matrix hosting the defects are considered. It is shown that crack initiation and propagation depend in a non-trivial way on crystallographic orientation and its associated plastic behavior as well as on the shape of the pore.     

Macroeconomic impacts of bioenergy production on surplus agricultural land—A case study of Argentina

This paper assesses the macroeconomic impacts in terms of GDP, trade balance and employment of large-scale bioenergy production on surplus agricultural land. An input–output model is developed with which the direct, indirect and induced macroeconomic impacts of bioenergy production and agricultural intensification, which is needed to make agricultural land become available for bioenergy production, are assessed following a scenario approach. The methodology is applied to a case study of Argentina. The results of this study reveal that large-scale pellet production in 2015 would directly increase GDP by 4%, imports by 10% and employment by 6% over the reference situation in 2001. When accounting for indirect and induced impacts, GDP increases by 18%, imports by 20% and employment by 26% compared to 2001. Agricultural intensification reduces but does not negate these positive impacts of bioenergy production. Accounting for agricultural intensification, the increase in GDP as a result of bioenergy production on surplus agricultural land would amount to 16%, 20% in imports and 16% in employment compared to 2001.     

Sugars and organic acids in Japanese plums (Prunus salicinaLindell) as influenced by maturation, harvest date, storage temperature and period

The effects of fruit maturation, harvest date, storage temperature, storage period and shelf life, on the concentrations of individual sugars and organic acids in Japanese plums were investigated. During fruit maturation in 'Amber Jewel' plums, sucrose concentration increased significantly from 101 days after full bloom (DAFB) to 1 week after commercial maturity (136 DAFB) with a non-significant change in the concentration of total organic acids and malic acid, the major organic acid. The changes in concentrations of sugars and organic acids during cold storage of 'Amber Jewel' plums harvested on 129 and 136 DAFB appeared to be independent of harvest date. Storage of 'Amber Jewel' plums at 5 °C accelerated the loss of sucrose and increased the concentrations of fructose and glucose from the 4^th week of storage compared with those stored at 0 °C. 'Blackamber' plums did not undergo any significant increase in the total and individual sugars during 5 weeks storage and subsequent shelf-life of 8 days at 20 °C. Malic acid concentrations declined during storage from 3 weeks onwards with a further substantial loss during ripening at 20 °C. Maturation, harvest date, storage temperature, storage period and shelf-life affect the concentrations of sugars and organic acids in Japanese plums.     

Microstructure Characterization of Cold‐Rolled Dual‐Phase Steels

The evolution of the microstructure of cold‐rolled dual‐phase steels during annealing is investigated. For this purpose, a cold‐rolled dual‐phase grade is annealed in the laboratory. Annealing cycles are applied to systematically investigate various cooling rates and isothermal holding temperatures and times relevant for continuous annealing lines exhibiting an overaging zone. In addition to the characterization of the microstructure by means of light optical metallography and transmission electron microscopy, mechanical properties are presented.