Unprecedented Selective Oxidation of Styrene Derivatives using a Supported Iron Oxide Nanocatalyst in Aqueous Medium

Iron oxide nanoparticles supported on mesoporous silica‐type materials have been successfully utilized in the aqueous selective oxidation of alkenes under mild conditions using hydrogen peroxide as green oxidant. The supported catalyst could be easily recovered after completion of the reaction and reused several times without any loss in activity (no metal leaching observed during the reaction), constituting a facile and straightforward example of aqueous oxidation chemistry promoted by iron‐based heterogeneous systems.     

Two-layer synchronized ternary quantum-dot cellular automata wire crossings

ABSTRACT: : Quantum-dot cellular automata are an interesting nanoscale computing paradigm. The introduction of the ternary quantum-dot cell enabled ternary computing, and with the recent development of a ternary functionally complete set of elementary logic primitives and the ternary memorizing cell design of complex processing structures is becoming feasible. The specific nature of the ternary quantum-dot cell makes wire crossings one of the most problematic areas of ternary quantum-dot cellular automata circuit design. We hereby present a two-layer wire crossing that uses a specific clocking scheme, which ensures the crossed wires have the same effective delay.     

Parameter optimization for the enzymatic hydrolysis of sunflower oil in high-pressure reactors

This study is concerned with the hydrolysis of sunflower oil in the presence of lipase preparation Lipolase 100T (Aspergillus niger lipase). Supercritical carbon dioxide was used as a solvent for this reaction. In a high-pressure stirred tank reactor operated in a batch mode, the effects of various process parameters (temperature, pressure, enzyme/substrate ratio, pH, and oil/buffer ratio) were investigated to determine the optimal reaction rate and conversion for the hydrolysis process. The optimal concentration of lipase was 0.0714 g/mL of CO₂-free reaction mixture, and the highest conversions of oleic acid (0.193 g/g of oil phase) and linoleic acid (0.586 g/g of oil phase) were obtained at 50°C, 200 bar, pH=7, and an oil/buffer ratio of 1∶1 (w/w).     

Modeling of kinetics for the enzymatic hydrolysis of sunflower oil in a high-pressure reactor

This study presents a mathematical model for characterizing the Michaelis-Menten type of sunflower oil hydrolysis, catalyzed by the lipase preparation Lipolase 100T (Novozymes Ays, Bagsvaerd, Denmark). Supercritical carbon dioxide was used as a solvent for this reaction. Computer modeling of the kinetics was done for the enzymatic hydrolysis of sunflower oil in a high-pressure reactor using the MicroMath Scientist^® program (Micro-Math Research, St. Louis, MO). On the basis of the experimental results, we presumed the reaction was reversible. The suitability of the model was confirmed statistically with Student's t-test. Good agreement was found between the experimental and calculated values for the concentrations of oleic and linoleic acids.     

Improving multimodal web accessibility for deaf people: sign language interpreter module

The World Wide Web is becoming increasingly necessary for everybody regardless of age, gender, culture, health and individual disabilities. Unfortunately, there are evidently still problems for some deaf and hard of hearing people trying to use certain web pages. These people require the translation of existing written information into their first language, which can be one of many sign languages. In previous technological solutions, the video window dominates the screen, interfering with the presentation and thereby distracting the general public, who have no need of a bilingual web site. One solution to this problem is the development of transparent sign language videos which appear on the screen on request. Therefore, we have designed and developed a system to enable the embedding of selective interactive elements into the original text in appropriate locations, which act as triggers for the video translation into sign language. When the short video clip terminates, the video window is automatically closed and the original web page is shown. In this way, the system significantly simplifies the expansion and availability of additional accessibility functions to web developers, as it preserves the original web page with the addition of a web layer of sign language video. Quantitative and qualitative evaluation has demonstrated that information presented through a transparent sign language video increases the users’ interest in the content of the material by interpreting terms, phrases or sentences, and therefore facilitates the understanding of the material and increases its usefulness for deaf people.     

Solid catalysts for the production of fine chemicals: the use of ALPON and hydrotalcite base catalysts for the synthesis of arylsulfones

α#x2010;phenylsulfonylcinnamononitrile and derivatives as well as α-phenylsulfonylchalcone have been obtained by condensation of phenylsulfonylacetonitrile and phenylsulfonylacetophenone with benzaldehyde and 4-substituted benzaldehydes, using solid base catalysts with different basic strengths. Cs-exchanged X zeolite showed low activity for the above reactions, while high-surface-area MgO and MgO–Al₂O₃ mixed oxides derived from hydrotalcite were active and selective catalysts. An optimum basicity was observed with MgO–Al₂O₃ with the atomic ratio Al/(Al+Mg) between 0 and 0.20, showing the increase in basicity when introducing Al in the MgO structure. Nitridation of a high-surface-area aluminophosphate gives active and selective catalysts for the above reactions. The activity per unit surface area for the less demanding reaction between sulfonylacetonitrile and benzaldehyde is directly proportional to the level of nitridation. However, formation of α-phenylsulfonylchalcone, which is a more demanding reaction, does not increase linearly but goes through a maximum with the nitrogen content of the solid, showing the heterogeneity of active sites on ALPONs and the decrease in the activity coefficient of the basic sites when the density of N atoms increases. This revised version was published online in July 2006 with corrections to the Cover Date.     

3D Electrophoresis‐Assisted Lithography (3DEAL): 3D Molecular Printing to Create Functional Patterns and Anisotropic Hydrogels

The ability to easily generate anisotropic hydrogel environments made from functional molecules with microscale resolution is an exciting possibility for the biomaterials community. This study reports a novel 3D electrophoresis‐assisted lithography (3DEAL) platform that combines elements from proteomics, biotechnology, and microfabrication to print well‐defined 3D molecular patterns within hydrogels. The potential of the 3DEAL platform is assessed by patterning immunoglobulin G, fibronectin, and elastin within nine widely used hydrogels and characterizing pattern depth, resolution, and aspect ratio. Furthermore, the technique's versatility is demonstrated by fabricating complex patterns including parallel and perpendicular columns, curved lines, gradients of molecular composition, and patterns of multiple proteins ranging from tens of micrometers to centimeters in size and depth. The functionality of the printed molecules is assessed by culturing NIH‐3T3 cells on a fibronectin‐patterned polyacrylamide‐collagen hydrogel and selectively supporting cell growth. 3DEAL is a simple, accessible, and versatile hydrogel‐patterning platform based on controlled molecular printing that may enable the development of tunable, chemically anisotropic, and hierarchical 3D environments.