Controlled lateral spreading and pinning of oil droplets based on topography and chemical patterning

Geometric pinning sites can be used to control the lateral spreading and pinning of oils on surfaces. The geometric pinning effect combined with lithographic surface chemistry patterning allows controlling the shapes of oil droplets. We study the confinement effect on test structures of various protruding and intruding geometries, and employ scanning electron microscopy analysis to study the shape of the meniscus at the edges of the chemical patterns. Nanopillar and micropillar topographies are compared, revealing that it is a necessity for accurate oil patterns that the length scale of the roughness is smaller than the resolution of the surface chemistry pattern. We also find that there exists a critical, geometry-dependent threshold contact angle, below which the geometric confinement does not work, as olive oil with a static advancing contact angle of 57° accurately replicated the chemical pattern on top of nanopillar topography, but hexadecane with a static advancing contact angle of 50° penetrated the pinning sites and wetted the whole surface.     

A rotating holographic imager for stationary cloud droplet and ice crystal measurements

Optical Review - An optical cloud droplet and ice crystal measurement system ICEMET (icing condition evaluation method), designed for present icing condition monitoring in field conditions, is...     

A high sampling rate digital holographic imager instrument for the in situ measurements of hydrometeors

A novel digital in-line holographic imaging instrument designed for acquiring properties of individual hydrometeors in situ is presented. The instrument has a large measurement volume of 670 cm³. This combined with fast frame rate imaging and software controlled multi-exposure capabilities results in a representative sampling of rain and snowfall events. Hydrometeors are measured and analyzed from the in-focus images with microscopic resolution, and their 3D locations inside the measurement volume are determined. The instrument is designed to operate in cold climates and to produce reliable measurements also during strong winds. The imaging rate of the instrument was designed to be adequately high to observe the dynamic nature of rain and snow falls. By recording multi-exposure holograms, the effective frame rate can be increased. This allows the measurements of the velocities of the fast-falling hydrometeors. The instrument and the hologram processing are described; as well as results from laboratory tests and the first field measurements are shown. As a result, the resolving power of the instrument was measured to vary between 11 and 18 microns inside the measurement volume near the center of the field-of-view. Velocity vectors were measured both from multi-exposure and high frame rate holograms. The measured velocities ranged from 0.1 to 4 m/s. In addition, the projections of a flat-shaped and rotating snowflake imaged at different locations inside the measurement volume demonstrated the possibility to estimate the shape of the hydrometeor from multiple viewing angles.     

Vapor–liquid equilibrium for binary system of tetrahydrothiophene + 2,2,4-trimethylpentane and tetrahydrothiophene + 2,4,4-trimethyl-1-pentene at 358.15 and 368.15 K

Isothermal vapor–liquid equilibrium (VLE) for tetrahydrothiophene + 2,2,4-trimethylpentane and tetrahydrothiophene + 2,4,4-trimethyl-1-pentene at 358.15 and 368.15 K were measured with a circulation still. All systems studied exhibit positive deviation from Raoult's law. No azeotropic behavior was found in all systems at the measured temperatures. The experimental results were correlated with the Wilson model and compared to COSMO-SAC predictive model. Analyses of liquid and vapor phase composition were determined with gas chromatography. All VLE measurements passed the three thermodynamic consistency tests used. The activity coefficients at infinite dilution are also presented.     

Selective Inhibitors of FKBP51 Employ Conformational Selection of Dynamic Invisible States

The recently discovered SAFit class of inhibitors against the Hsp90 co‐chaperone FKBP51 show greater than 10 000‐fold selectivity over its closely related paralogue FKBP52. However, the mechanism underlying this selectivity remained unknown. By combining NMR spectroscopy, biophysical and computational methods with mutational analysis, we show that the SAFit molecules bind to a transient pocket in FKBP51. This represents a weakly populated conformation resembling the inhibitor‐bound state of FKBP51, suggesting conformational selection rather than induced fit as the major binding mechanism. The inhibitor‐bound conformation of FKBP51 is stabilized by an allosteric network of residues located away from the inhibitor‐binding site. These residues stabilize the Phe67 side chain in a dynamic outward conformation and are distinct in FKBP52, thus rationalizing the basis for the selectivity of SAFit inhibitors. Our results represent a paradigm for the selective inhibition of transient binding pockets.     

Inkjet printed System-in-Package design and manufacturing

Additive manufacturing technology using inkjet offers several improvements to electronics manufacturing compared to current non-additive masking technologies. Manufacturing processes can be made more efficient, straightforward and flexible compared to subtractive masking processes, several time-consuming and expensive steps can be omitted. Due to the additive process, material loss is minimal, because material is never removed as with etching processes. The amounts of used material and waste are smaller, which is advantageous in both productivity and environmental means. Furthermore, the additive inkjet manufacturing process is flexible allowing fast prototyping, easy design changes and personalization of products. Additive inkjet processing offers new possibilities to electronics integration, by enabling direct writing on various surfaces, and component interconnection without a specific substrate. The design and manufacturing of inkjet printed modules differs notably from the traditional way to manufacture electronics. In this study a multilayer inkjet interconnection process to integrate functional systems was demonstrated, and the issues regarding the design and manufacturing were considered.     

Electrically Conductive Metal Polymer Nanocomposites for Electronics Applications

An electrically conductive nanocomposite composed of thermoplastic elastomer and nanosized silver particles was developed. Nanosized silver particles were produced by the liquid flame spraying method. Nanocomposites were produced employing a batch mixing process in the melt state. The percolation curve and the minimum resistivity as a function of silver content were defined. A plasticized styrene block-copolymer was used as the matrix polymer. The results showed that the agglomeration of the silver particles has a major influence on the percolation threshold and the resistivity of the compound. With slightly agglomerated silver particles a percolation threshold with a silver content of 13–16 vol.% was achieved. The corresponding resistivity was 2.0 × 10⁻¹ Ω cm. With heavily agglomerated particles the resistivity is high (2.9 × 10³ Ω cm), even with a silver content of 20 vol.%. With a low primary silver particle size (under 100 nm), the resistivity of the compound was high (5.6 × 10⁵ Ω cm).     

Developments in WTDM technology for high-capacity optical studio networks

This paper reviews results achieved in high-capacity optical networking for television studios under RACE projects 1036 and 2001. A network based on wavelength- and time-division multiplexing (WTDM) has been demonstrated, which, using 16 wavelengths, provides a total capacity of 39.8 Gbit s^-1. We summarize previously reported results obtained in the system test-bed, which demonstrate the distribution of uncompressed digital video signals ranging from PAL at 142 Mbit s^-1 to HDTV at 1.15 Gbit s^-1. The process of further developing this technology for a pilot installation has established that it will be applicable not only to central routeing within a television studio but also to resilient network provision and the interconnection of remote sites. We review how network resilience is achieved by multiple interconnected star architectures and outline how recent results with integrated star couplers suggest that these designs can be delivered at low cost. We report new experiments demonstrating an optically amplified network over a commercially installed 36-km link, thus confirming the feasibility of a long-reach routeing system. We also report results illustrating how lithium niobate devices can perform optical switching on the wavelength multiplex and thus offer potential advantages in system transparency and throughput. Our conclusion is that we have confirmed the feasibility of the WTDM concept and demonstrated its potential for wider application.GEC-Marconi Defence SystemsThomson-CSFNorthern Telecom Europe     

Phénylation d'alcools allyliques acycliques : II. Regioselectivite du transfert d'hydrogene

PdCl₂, HNaCO₃-catalysed phenylation of deuterium-labelled allylic butenols, a Heck type reaction, proceeds by a highly regioselective 1,2-hydrogen shift $\text{via}$ a Wacker type intermediate. No decomplexed enol was formed during this reaction.