Synthesis and Characterization of Poly(ethylene glycol) Methacrylate Based Hydrogel Networks for Anti‐Biofouling Applications

A series of hydrogels based on poly(ethylenglycol) methyl ether methacrylate (PEGMEMA) is synthesized using macromonomers of three different molecular weights, in combination with varied degrees of chemical crosslinking. The effects of PEGMEMA, initiator, and crosslinker concentrations on gel yield and swelling properties are studied. In addition, the chemical structure of the gels is characterized by FTIR and solid‐state NMR spectra. The swelling and rheological behaviors of hydrogels as well as protein partitioning into the gels are discussed in terms of the network mesh size. Low protein sorption and bacteria deposition tendencies indicate that PEGMEMA‐based hydrogels could be highly beneficial for uses as fouling‐resistant materials, for instance, as protective coatings for desalination membranes.

     

Cr-Ge-Si Alloys for High-Temperature Structural Applications: Microstructural Evolution

The microstructural evolution of Cr-Si_1?x -Ge _x (0 < x < 15 at. pct) alloys was studied (in annealed state). The quasi-isothermal section of the ternary diagram was assessed by quantitative EPMA analysis. Morphology, phase formation, chemical distribution, and indentation hardness of the alloys were investigated as a function of Ge/Si ratio. The microstructure of all studied alloys consisted of Cr_ss solid solution and A15 Cr₃X intermetallic phases. Substitution of Si by Ge strongly altered the microstructure by transforming the morphology from a lamellar eutectic Cr-Cr₃Si system toward a peritectic one with dispersed Cr_ss phase in A15 matrix. EPMA chemical distribution maps and X-ray diffraction results prove the mutual solubility of Si and Ge in A15 phase by forming Cr₃(Si,Ge) as a complex A15 structure with Cr₃(Si_1?x Ge _x ) composition. Precipitates of the intermetallic phase within the Cr_ss phase was observed in Ge-alloyed samples. Indentation hardness results showed that upon Si-Ge substitution the hardness of both phases was reduced. However, Si substitution by Ge had a stronger influence on the hardness of the solid solution phase than on the intermetallic phase.     

Nonlinear rotation‐free three‐node shell finite element formulation

A new triangular thin‐shell finite element formulation is presented, which employs only translational degrees of freedom. The formulation allows for large deformations, and it is based on the nonlinear Kirchhoff thin‐shell theory. A number of static and dynamic test problems are considered for which analytical or benchmark solutions exist. Comparisons between the predictions of the new model and these solutions show that the new model accurately reproduces complex nonlinear analytical solutions as well as solutions obtained using existing, more complex finite element formulations. Copyright © 2013 John Wiley & Sons, Ltd.     

A kit formulation for preparation of [(111)In]In-DTPA-folate, a folate-receptor-targeted radiopharmaceutical

A kit formulation has been developed for convenient, routine compounding of (111)In-labeled In(III)-DTPA-Folate, an investigational radiopharmaceutical for targeting tumor-associated folate receptors. The kit consists of the DTPA-Folate conjugate in sodium citrate solution, from which [(111)In]In-DTPA-Folate can be rapidly and reliably compounded by the addition of aqueous [(111)In]In(III)-chloride.     

Magnetic field enhanced press-filtration

The proposed hybrid process represents a new application of a magnetic field which directly influences a classical press filtration. The new technology offers high potential in the field of magnetic pigment production and iron oxide processing as well as bio-separation with functionalized magnetic particles. Especially in the field of fine-scale particulate product systems high specific cake resistances result in slow cake building and dewatering kinetics, which leads to economic inefficiency.Experimental and theoretical investigations show that the magnetic field has strong influence on cake building. Two major effects were observed: (I) In inhomogeneous magnetic fields magnetic particles experience a magnetic force counter directed to the pressure force, that results in slow down of cake formation; (II) Interparticle magnetic forces lead to structured cake formation.This gives on one hand the possibility to uncouple fluid and magnetic particle motion to force a cake built-up in designated location of the filter chamber. The result is a big increase of the overall filtrate mass flow and therefore an improvement of filtration kinetics. On the other hand due to the particle's magnetization including the formation of an attracting north and south-pole chainlike agglomerates can be observed. This leads to a “structured” cake building and therefore higher permeability.This work will show the effect of a superposed magnetic field on press filtration of ferromagnetic iron oxide particles (Fe₃O₄) in a lab-scale filter press.     

FLAG: a flexible layout generator for analog MOS transistors

This paper describes a flexible MOS transistor layout generator which draws optimal layouts whatever the W and L dimensions. The drawing methodology is based on the use of small elementary parts, called bricks, which are placed side by side inside a user-specified boundary. The generated transistors may allow diffusion merging along whichever sides the user wishes and may have a global rectilinear shape. The internal structure of these cells may also be chosen by the designer so that it is well suited to his application. Transistors developed using this generator have been tested, and have been used to build a simple operational amplifier.