Tailoring Fe/Ag Superparamagnetic Composites by Multilayer Deposition

The magnetic properties of Fe/Ag granular multilayers were examined by SQUID magnetization and Mossbauer spectroscopy measurements. Very thin (0.2 nm) discontinuous Fe layers show superparamagnetic properties that can be tailored by the thickness of both the magnetic and the spacer layers. The role of magnetic interactions was studied in novel heterostructures of superparamagnetic and ferromagnetic layers and the specific contribution of the ferromagnetic layers to the low field magnetic susceptibility was identified.Comment: 5 pages and 3 figure

Ultrathin graphene-based membrane with precise molecular sieving and ultrafast solvent permeation

Graphene oxide (GO) membranes continue to attract intense interest due to their unique molecular sieving properties combined with fast permeation. However, their use is limited to aqueous solutions because GO membranes appear impermeable to organic solvents, a phenomenon not yet fully understood. Here, we report efficient and fast filtration of organic solutions through GO laminates containing smooth two-dimensional (2D) capillaries made from large (10-20 μm) flakes. Without modification of sieving characteristics, these membranes can be made exceptionally thin, down to â 1/410 nm, which translates into fast water and organic solvent permeation. We attribute organic solvent permeation and sieving properties to randomly distributed pinholes interconnected by short graphene channels with a width of 1 nm. With increasing membrane thickness, organic solvent permeation rates decay exponentially but water continues to permeate quickly, in agreement with previous reports. The potential of ultrathin GO laminates for organic solvent nanofiltration is demonstrated by showing >99.9% rejection of small molecular weight organic dyes dissolved in methanol. Our work significantly expands possibilities for the use of GO membranes in purification and filtration technologies

Functionalized boron nitride membranes with ultrafast solvent transport performance for molecular separation

Pressure-driven, superfast organic solvent filtration membranes have significant practical applications. An excellent filtration membrane should exhibit high selectivity and permeation in aqueous and organic solvents to meet increasing industrial demand. Here, we report an amino functionalized boron nitride (FBN) based filtration membrane with a nanochannel network for molecular separation and permeation. This membrane is highly stable in water and in several organic solvents and shows high transport performance for solvents depending on the membranes' thickness. In addition, the FBN membrane is applicable for solute screening in water as well as in organic solvents. More importantly, the FBN membranes are very stable in acidic, alkaline and oxidative media for up to one month. The fast-flow rate and good separation performance of the FBN membranes can be attributed to their stable networks of nanochannels and thin laminar structure, which provide the membranes with beneficial properties for practical separation and purification processes

Household structure, resource allocation and child well-being. A comparison across family systems

Contains fulltext : 94468.pdf (publisher's version ) (Open Access)26 p

Sibling struggle for schooling: between resource dilution and collaborative learning, the Netherlands, 1850-1920’

Item does not contain fulltext17 p

The Impact of Kin Co-residence on Survival Chances of Infants and Children in the Netherlands, 1863-1909. A New Methodological Approach

Item does not contain fulltextIn this article, we present the first results of a new approach to the study of survival chances of Dutch children born between 1863 and 1909 (N=30157). We take a ‘snapshot’ of the household composition at 90-days intervals and relate that to survival chances of the children, using a generalized linear model. We look at the impact of different types of co-resident kin, after controlling for many variables that also affect child survival. The results suggest a strong positive effect of the mother’s mother and the father’s father, as well as of older siblings. Significant positive effects were also found for father’s mother and for uncles. Our outcomes suggest that adding the presence of family members of different type to the commonly used covariates yields a more complete picture of infant and child well-being.22 p

Proceedings of Distribution Europe Conference

Marketers often use salient stimuli to draw consumers' attention to a specific brand in the hope that a selective focus on the brand increases the sales of this brand. However, previous studies are inconsistent concerning the impact that selectively focusing on a specific brand has on final brand choice. To offer an explanation for these inconsistent results, this paper introduces decision involvement as a moderator of the relation between selective focus and attitude–decision consistency. Two studies indicate that selectively focusing on a not preferred alternative indeed alters choice decisions, but only when decision involvement is low. Study 1 further shows that this interaction effect between selective focus and involvement takes place in the selection rather than the brand consideration stage. By introducing level of processing along with decision involvement, Study 2 shows that the interaction effect emerges even in limited processing conditions. The study also reconciles different explanations for the negative effect of selective focus on attitude–behavior consistency. Selectively focusing on a not preferred choice option when consumers are low involved and use limited processing seems to lead to inconsistent choices because of an increased accessibility of the focal option, whereas selective focus on a not preferred option when consumers are low involved and use deep processing lead to inconsistent choices because of attitude polarization. © 2011 Wiley Periodicals, Inc

Free Volume Expansion of Poly[1-(trimethylsilyl)-1-propyne] Treated in Supercritical Carbon Dioxide As Revealed by Positron Annihilation Lifetime Spectroscopy

The free volume changes of poly[1-(trimethyl-silyl)-1-propyne] (PTMSP) treated in supercritical CO2 (scCO(2)) were investigated with positron annihilation lifetime spectroscopy (PALS). CO2 is known to plasticize and increase the free volume size of a broad range of polymers. In this work dense PTMSP films were treated with scCO(2) under different pressures and temperatures, resulting in the enlargement of the characteristic channel-like holes (R-3) and the larger free volume cages (R-4) up to 39% and 19%, respectively. The free volume enlargement was found to have a relaxation time of similar to 30 years. At higher temperatures (110-150 degrees C), the o-Ps intensities and gel permeation chromatography (GPC) data revealed chemical changes of the scCO(2)-treated polymer due to the onset of PTMSP's degradation. However, at lower temperatures (40-70 degrees C), significant free volume cavity size increases to 25% for R-3 and 9% for R-4 were also observed