bluuebunny/crossref_metadata_2025 huggingface dataset:
Chemical Pressure
Authors: Hauser Andreas , Amstutz Nahid , Delahaye Sandra , Sadki Asmaâ , Schenker Sabine , Sieber Regula , Zerara Mohamed
Published: June 2006

The physical and photophysical properties of three classic transition metal complexes, namely [Fe(bpy)3]2+, [Ru(bpy)3]2+, and [Co(bpy)3]2+, can be tuned by doping them into a variety of inert crystalline host lattices.
The underlying guest-host interactions are discussed in terms of a chemical pressure.
Biotechnology in Switzerland is Alive – Also at the Universities of Applied Sciences Die Schweizer Biotechnologie lebt – auch auf Fachhochschulebene
Authors: Gygax Daniel , Baumberger Franz , Graf-Hausner Ursula , Schmid Sergio , Sievers Martin , Perriarde Serge
Published: June 2006

For more than two years five Swiss Universities of Applied Sciences have been cooperating in the field of biotechnology. The aim of the Swiss BioteCHnet, which was founded in the summer of 2002 and officially recognized by the Federal Department of Economic Affairs, is to act as a valuable
partner for the business world. The first results have been successful.
Recent Advances in the Chemistry of Clusters and Inorganic Polymers of Alkali and Alkaline Earth Metal Compounds
Authors: Fromm Katharina M.
Published: June 2006

This contribution gives an overview on the different subjects treated in our group during the last four years. First, the concept of cutting out structural fragments from a solid-state structure will be explained on behalf of BaI2. Oxygen donor ligands, used as chemical scissors
on BaI2, enabled three-, two-, one- and zero-dimensional derived compounds to be obtained depending on their size and concentration. Thus, a structural genealogy tree for BaI2 can be established. A second section deals with the supramolecular approach for the synthesis
of different dimensional polymer structures derived from alkaline earth metal iodides, and based on the combination of metal ion coordination with hydrogen bonding between the cationic complexes and their anions. Under certain circumstances, rules can be established for the prediction of the
dimensionality of a given compound, thus contributing to the problem of structure prediction in crystal engineering. A third part describes a new synthetic pathway for generating homometallic alkaline earth metal clusters as well as group 1 and 2 mixed metal clusters as potential precursors
for oxide materials. Finally, some physical properties of these compounds are described qualitatively in order to show the wide spectrum of possibilities and potential applications for the chemistry in this field.
Chiral Ion Mediated Asymmetric Chemistry
Authors: Lacour Jérôme
Published: June 2006

The octahedral geometry of pentavalent hexacoordinated phosphorus allows the formation of chiral anions by complexation of the central phosphorus atom with three bidentate ligands. These simple-to-make derivatives can be combined with chiral cations and often display efficient NMR chiral
shift, resolving and asymmetry-inducing properties. This paper is a short review of our research efforts directed towards the development of chiral anion mediated asymmetric chemistry.
Resolution of Microscopic Protonation Mechanisms in Polyprotic Molecules
Authors: Borkovec Michal , Brynda Marcin , Koper Ger J. M. , Spiess Bernard
Published: June 2006

Microscopic ionization equilibria can be fully resolved by means of a novel site-binding model, which is based on a cluster expansion technique borrowed from statistical mechanics. This model permits a parameterization of the problem, and offers substantial advantages over the commonly
used microscopic equilibrium constants. While the number of microconstants grows very rapidly with the size of the molecules, the necessary number of parameters of the site-binding model remain small, and one can even obtain common sets of such parameters within a homologous series of molecules.
Based on this approach, two methods to obtain such microconstants are discussed, namely based on NMR titration data, and on the analysis of potentiometric titrations within a homologous series.
Charged Polymer/Nanoparticle Mixtures: Monte Carlo Simulations
Authors: Laguecir Abohachem , Brynda Marcin , Stoll Serge
Published: June 2006

We used Monte-Carlo simulations to study the formation of complexes between charged polymers (or polyelectrolytes) with oppositely charged spherical nanoparticles. We presented the model, the Monte Carlo numerical method and investigated the effects of the ionic concentration of the
solution, polyelectrolyte rigidity (or flexibility), linear charge density, and surface charge of the nanoparticles. Polyelectrolyte adsorption is controlled by several competing effects. On the one hand, rigidity and electrostatic repulsion force the polyelectrolyte to adopt extended conformations
and limit the number of monomers which may be attached to the nanoparticles. On the other hand, electrostatic attractive interactions between the particle and the polyelectrolyte monomers force the chain to undergo a structural transition and collapse at the particle surface. By increasing
the intrinsic rigidity, we observed a transition from disordered and strongly bound complexes to a situation where the polymer touches the particles over a finite length, while passing by the formation of a solenoid conformation. We found that the critical ionic concentration at which adsorption/desorption
is observed rapidly increases with the increase of the nanoparticle surface charge density in good agreement with experimental data dealing with the formation of complexes between micelles and oppositely charged polyelectrolytes. Adsorption is also promoted by decreasing the chain stiffness
or decreasing the salt concentration for a given chain length.
Chemical Synthesis in Microreactors
Authors: Schwalbe Thomas , Autze Volker , Wille Gregor
Published: June 2006

Chemical synthesis in microreactors is a novel way of conducting chemistry in a highly controlled way with improved yields at impressive selectivities and with reduced overall effort. This paper describes recent technological progress with the potential as well as the application of
the technology to chemical synthesis, discusses novel chemical optimization technology and reports on the transfer of the technology into production.
Catalyst Coatings for Microstructure Reactors
Authors: Haas-Santo Katja , Görke Oliver , Pfeifer Peter , Schubert Klaus
Published: June 2006

Catalytic active coatings for microchannels have been developed for metallic microstructure reactors in heterogeneous catalyzed gas phase reactions. To enhance the inner surface of microchannel reactors, porous metal oxide coatings have been made by various deposition techniques such
as sol–gel processes, anodic oxidation, and deposition of nanoparticles. The ceramic thin films have been developed as supports for catalytically active components like precious metals or as catalyst themselves. In an aluminum microstructure reactor the walls of the micro channels of
one passage was successfully coated with a porous alumina layer by a modified anodic oxidation method. Moreover, microchannels of microstructure reactors were successfully coated with SiO2, Al2O3 and TiO2 by the sol–gel process. First promising
results have been obtained from depositing oxide nanoparticles (ZnO, CuO and Al2O3) by washcoat or electrophoretic deposition methods.
Miniaturized Reactors in Combinatorial Catalysis and High-Throughput Experimentation
Authors: Zech Torsten , Claus Peter , Hönicke Dieter
Published: June 2006

Different approaches to study the advantages and challenges of miniaturized reactor systems for combinatorial catalysis and high-throughput experimentation are presented. These are a parallel microchannel reactor, a chip-based 'single microchannel' reactor, a monolithic reactor acting
as multichannel reactor, and a chip reactor design for liquid-phase processes. These developments are discussed in detail regarding their design, manufacturing and corresponding catalyst preparation issues. A number of applications are explained in conjunction with the description of a system
for spatially resolved high-throughput analytics.
High-Throughput Screening of Molecular Catalysts Using Automated Liquid Handling, Injection, and Microdevices
Authors: De Bellefon Claude , Abdallah Radwan , Lamouille Thierry , Pestre Nathalie , Caravieilhes Sylvain , Grenouillet Pierre
Published: June 2006

A new concept for the high-throughput screening of multiphase reactions involving molecular catalysts is described. It combines pulse injections of catalysts and substrate and mixing in a microdevice. The novelty of the concept resides in dynamic sequential vs. batchwise operations.
Some advantages over traditional batch parallel operations are lower inventory of sample (down to ?g) coupled with accurate control of reaction time, larger range of operating conditions (pressure, temperature), simpler and fewer electromechanical moving parts and easy automation. Results
on liquid–liquid (biphasic allylic alcohol isomerization), and gas–liquid (asymmetric hydrogenation) reactions indicates that the number of tests per day can easily reach 50d?1 with inventory of sample (Rh) per test as low as 5 ?g.
From Process Miniaturization to Structured Multiscale Design: The Innovative, High-Performance Chemical Reactors of Tomorrow
Authors: Matlosz Michael , Commenge Jean-Marc
Published: June 2006

The increasing use in recent years of microstructured components and devices for chemical analysis and laboratory applications has led to the development of a large number of miniaturized reactor systems of proven performance and interest for the chemical industries. The primary objective
of these small-scale devices has been to generate chemical information, and for such applications 'smaller' is very often 'better' since smaller devices allow for use of smaller reactant volumes. Contrary to chemical information, however, chemical production (even for mini-plants) implies
the use of significant volumes of reactants, and the motivations for employing microstructured systems in such cases require therefore closer examination. Upon reflection, one concludes that the potential advantages of microstructured devices and components are not limited solely to process
miniaturization. On the contrary, incorporation of appropriately designed and targeted microstructured components within large-scale macrodevices can provide novel, innovative design concepts for performance enhancement, resulting in safer, cleaner and more efficient reactors and process units
for production plants of all sizes.
Design Guidelines and Manufacturing Methods for Microreaction Devices
Authors: Ehrfeld Wolfgang
Published: June 2006

Microreaction technology is a powerful tool for the evaluation of new reaction pathways, process intensification in chemical engineering and combinatorial material development. Because of the small characteristic dimensions of microreaction devices, mass and heat transfer processes
are enhanced and, in addition, initial and boundary conditions can be precisely adjusted for optimizing yield and selectivity. A number of microfabrication methods exist to cover prototyping and manufacturing of a few items as well as cost-effective mass production of modular and integrated
microdevices for unit operations, reactions and control. Detailed analyses of methods like LIGA technology, wet and dry micro-etching, mechanical micromachining and laser processing show that a wide variety of materials is applicable to meet most requirements of chemical processes.
Application of Microstructured Reactor Technology for the Photochemical Chlorination of Alkylaromatics
Authors: Ehrich Heike , Linke David , Morgenschweis Konrad , Baerns Manfred , Jähnisch Klaus
Published: June 2006

The advantageous application of a falling-film microreactor for a photochemical gas/liquid reaction was demonstrated by the selective photochlorination of toluene-2,4-diisocyanate (TDI). In the microstructured reactor the selectivity to the side-chain chlorinated product 1-chloromethyl-2,4-diisocyanatobenzene
(1Cl-TDI) achieved a value of 80% at 55% TDI conversion, whereas the side product toluene-5-chloro2,4-diisocyanate (5Cl-TDI) was formed with only 5% selectivity. The yield of 1Cl-TDI was enhanced by increasing the residence time from 24% after 5 s to 54% after 14 s. At the same time the formation
of consecutive products increased and the selectivity to 1Cl-TDI decreased to 67% after 14 s residence time. The influence of the reactor material was shown. In presence of a Lewis acid such as FeCl3, formed by chlorination using a reaction plate made of iron, consecutive products
were formed and the selectivity to 1Cl-TDI was lowered. The microstructured reactor led to remarkably higher selectivities than the conventional batch reactor, where the selectivity to 1Cl-TDI was only 45% at 65% TDI conversion and the side product 5Cl-TDI was formed with 50% selectivity.
The space-time yield of 1Cl-TDI achieved in the microstructured reactor (400 mol l?1 h?1) clearly exceeded the performance of the batch reactor (space-time yield 1.3 mol l?1 h?1). Based on the microreactor data, a kinetic
model for the TDI chlorination including by-product formation was suggested and used to predict product selectivity at full TDI conversion.
Prospects and Limitations of Carbon Nanotube Field Emission Electron Sources
Authors: Gröning Oliver , Clergereaux Richard , Nilsson Lars-Ola , Ruffieux Pascal , Gröning Pierangelo , Schlapbach Louis
Published: June 2006

Today the most mature technology to produce gated micro field electron emitter arrays is the so-called Spindt-type metal micro-tip process. The drawbacks of the Spindt-type process are the expensive production, the critical lifetime in technical vacuum and the high operating voltages.
Carbon nanotubes (CNT) can be regarded as the potential second-generation technology to Spindt-type metal micro-tips. The use of CNT as field enhancing structures in field emission electron sources can bring several advantages such as longer lifetime and operation in poor vacuum due to the
high chemical inertness as well as low operation voltages and perhaps most important very low cost production techniques. In the present contribution we show that the field electron emission (FE) of CNT thin films can be accurately described by Fowler-Nordheim tunneling and that the field
enhancement factor ? influences the emission properties most prominently. We have used scanning anode field emission microscopy to investigate the local field emission properties of randomly oriented carbon nanotube deposits. In the technically interesting applied electric field range
of 30 V/?m an emission site density larger than 5×106 cm?2 could be measured. We will discuss however that emitter degradation at high emission currents limits the full exploitation of this high emission site density. The emission degradation becomes apparent
for emission currents in the ?A range for a single emitter and the field emission I-V characteristics suggests that power dissipation due high contact or intra CNT resistance is the cause of the emitter degradation. Therefore, although the fundamental properties of CNTs are very favorable
for the use as field emission tips, these properties alone will not guarantee their success in this area. Our investigations clearly show that a perfect control of the catalytic CNT growth process is needed for successful CNT field emitter technology, at least for high current applications.
Molecular Electronics – Integration of Single Molecules in Electronic Circuits
Authors: Mayor Marcel , Weber Heiko B.
Published: June 2006

Electronic devices made with organic molecules may one day play an important role in integrated circuits. However, the research is still in its infancy. The mechanically controlled break-junction technique allows the measurement of the current through a single molecule junction. The
current–voltage relations indicate a nonlinear conductance. Information about the junction can be provided by comparative studies of different molecules. It turns out that the conduction properties depend strongly on the molecular structure. This, in turn, encourages the idea of tailoring
the electronic properties by an appropriate design of the molecule.
Controlled Growth and Applications of Carbon Nanotubes
Authors: Hernadi Klara , Chauvin Pauline , Klinke Christian , Croci Mirko , Forró László , Seo Jin Won , Mikó Csilla , Umek Polona , Couteau Edina , Bonard Jean-Marc
Published: June 2006

This article reviews recent results in the field of nanotube research obtained at EPFL. We show in particular that with catalytic deposition techniques such as chemical vapor deposition carbon nanotubes with controlled properties can be obtained. We then discuss the functionalization
of these CVD-grown nanotubes for the realization of fibers and composites, as well as their use in field emission devices.
Molecular Assembly and Self-Assembly: Molecular Nanoscience for Future Technologies
Authors: De Wild Michael , Berner Simon , Suzuki Hitoshi , Ramoino Luca , Baratoff Alexis , Jung Thomas A.
Published: June 2006

In this review the emerging science of single molecules is discussed from the perspective of nanoscale molecular functions and devices. New methods for the controlled assembly of well-defined molecular nanostructures are presented: self assembly and single molecular positioning. The
observation and selective modification of conformation, electronics, and molecular mechanics of individual molecules and molecular assemblies by scanning probes are demonstrated. To complement this scientific review, some of the possible consequences and visions for future developments are
discussed, as far as they derive from the presented systems. Here, the prospects of nanoscale science to stimulate technological evolution are exemplified.
Heterogeneous Catalysis by Flame-Made Nanoparticles
Authors: Stark Wendelin J. , Pratsinis Sotiris E. , Baiker Alfons
Published: June 2006

In search of highly active nanoparticles for catalytic applications, flame aerosol technology turns out to be a promising method for its capacity to consistently produce highly pure nanoparticles. Starting with the production of simple oxides such as silica and titania in the forties,
flame aerosol technology now facilitates production of nanoparticles in megaton quantities. Fundamental research on particle formation in the gas phase and the influence of process parameters and reactor design on final product properties have advanced the field to a stage where multicomponent
materials can be produced. Flame production of vanadia/titania catalysts for NOx removal from exhaust gases by selective reduction by ammonia affords enhanced activity at low temperature when compared to corresponding materials prepared by wet-chemical methods. Furthermore, flame synthesis
of titania/silica yields catalysts for the epoxidation of olefins with high accessibility of the active titanium sites and improved selectivity. Spectroscopic studies revealed that the same active sites as in the wet-phase derived catalysts are produced by flame synthesis but at a higher content.
The high temperature during the preparation favors the formation of well-defined species on a hydrophobic surface. The flame synthesis of heterogeneous catalysts is brought from laboratory scale to pilot scale production at up to 500 g/h to make the novel materials suitable for industrial
performance tests.
Efficient Replication of Nanostructured Surfaces
Authors: Schift Helmut , Heyderman Laura J. , Gobrecht Jens
Published: June 2006

The defined fabrication of nanostructures on surfaces for the nanosciences today largely relies on tools such as scanning probe instruments or electron- and ion beam systems that are serial writing processes. For future production of components and devices, in particular if large nanostructured
areas are needed, parallel processes, which are fast and cost-effective, have to be developed. In this paper we review the possibilities for the replication of nanostructures on surfaces using moulding of thermoplastic polymer materials. Using hot embossing, it has been shown that structures
below 10 nm can be reproduced reliably and with a high fidelity using laboratory equipment. Mass fabrication of nanostructured components can be achieved using thermal injection moulding with cycle times in the order of 10 sec.
Printing Meets Lithography: Soft Approaches to High-Resolution Patterning
Authors: Michel Bruno , Stutz Richard , Schmidt-Winkel Patrick , Schmid Heinz , Rothuizen Hugo , Renault Jean-Philippe , Kind Hannes , Juncker David , Geissler Mattias , Delamarche Emmanuel , Bietsch Alexander , Bernard André , Wolf Heiko
Published: June 2006

We are developing a high-resolution printing technique based on transferring a pattern from an elastomeric stamp to a solid substrate by conformal contact. This is an attempt to enhance the accuracy of classical printing to a precision comparable with optical lithography, creating a
low-cost, large-area, high-resolution patterning process. First, we introduce the components of this technique, called soft lithography, and review its evolution. Topics described in detail are the stamp material, stamp architecture, pattern design rules, and printing tools. The accuracy of
the prints made by thin patterned elastomeric layers supported on a stiff and flexible backplane is then assessed, and defects are characterized using a new electrical metrology approach. This is followed by a discussion of various printing processes used in our laboratory: (1) thiol printing
for high-resolution patterns of noble metals that may also be used as sacrificial masks; (2) confined contact processing with liquids in cavities or channels to chemically convert a substrate or deposit layers of materials or biomolecules; (3) printing of catalysts to mediate patterned deposition
of metals; and (4) structured, light-guiding stamps for transferring high-resolution patterns into photoresists. Finally, we compare classical and high-resolution printing approaches, and describe their potential for emerging micro- and nanoscale patterning technologies.
Nanotechnology in Medicine: Moving from the Bench to the Bedside
Authors: Hunziker Patrick R. , Stolz Martin , Aebi Ueli
Published: June 2006

While living matter is composed of a large number of biological nanomachines, it has been recognized early in the history of nanotechnology that medicine could be a prime field for application. Now that nanotechnology has gone beyond its infancy, its mature arsenal of tools, methods
and materials is ready for applications outside physics. While true clinical applications of nanotechnology are still practically non-existent at the current time, a significant number of promising medical projects is at an advanced experimental stage. Tools based on the atomic force microscope
will not only allow improved imaging of living matter but can also serve as functional probes and will even serve as sensitive sensors for a broad range of molecules of medical interest. New immunological tests based on microcontact printing and microfluidics will significantly improve medical
laboratory diagnosis. New materials, including nanotubes and fullerenes, nanocontainers and other self-assembled structures may improve mechanical properties and biocompatibility of implants and will allow new approaches in drug targeting.
The Oenology Department of the Engineering School of Changins
Authors: Fabre Sebastien
Published: June 2006

The Engineering School of Changins, as part of the University of Applied Sciences of Western Switzerland (HES-SO), is the only one In Switzerland to provide an Oenology Department. The course lasts six semesters with an additional semester for the dissertation. The Engineering School
of Changins has developed an applied research activity, supporting small and middle-size enterprises (SME) of the oenology sector. The goal is to improve the quality of wine in Switzerland. The Engineering School of Changins has always worked to serve the wine-making industry with advice and
assistance, performing expert evaluations and analyses.
Trace Determination of Hydrogen in Coke by Elemental Analysis
Authors: Cicciarelli Romolo , Zuber Basil , Ambort Christian
Published: June 2006

Recarburizers used in the steel industry are ruthlessly selected according to their quality. One of the critical parameters is the residual hydrocarbon content of the coke or graphite-based products. The current analytical procedure has a detection limit of about 0.2% hydrogen. The
dynamic flash combustion of the sample coupled with gas chromatography (GC) was used to develop a simple method for the determination of hydrogen traces in coke. The sample was burned in an oxygen/helium atmosphere at 1020 °C. Separation of the combustion gases, NO2, CO2,
H2O, and SO2, is accomplished on a chromatography column and measured by a thermal conductivity detector TCD. A linear response of hydrogen over a concentration range of 98–4910 mg kg?1 with a correlation coefficient of 0.9985 has been achieved.
A detection limit of 26 mg kg?1 and a determination limit of 92 mg kg?1 were obtained with new equipment configurations and a sample weight of 8 mg. This corresponds to an impressive improvement of sensitivity of a factor of over 70. The coefficient of variation
was found to be 31.3% at a concentration of 98 mg kg?1 and 0.7% at 4910 mg kg?1.
Applicability of a SPME method for the Rapid Determination of VOCs
Authors: Béné Alexandre , Luisier Jean-Luc , Fornage Antoine
Published: June 2006

A fast method for monitoring volatile organic compounds in water and air is described whereby the VOCs are adsorbed on a SPME and then desorbed directly in a flame ionization detector (FID) or a photoionization detector (PID). The signal obtained provides a global measure of the VOCs
present in water or air. In most cases, such as accidental pollution by hydrocarbons, wastewater from industry or control of the absence of solvent in air, this information is very relevant. The analysis can be handled by a non-professional with a throughput of 10 samples/h. Low levels of
about 10?g organic volatile compounds per liter of water can be measured.
Clarifying Investment in a Central Ripening Storehouse for Hard Cheese
Authors: Rohrer Christoph , Zaugg Urs
Published: June 2006

Decisions concerning the investment needed to replace installations in a cheese-ripening storehouse were examined in a diploma thesis. Three different versions were compared from the points of view of cost calculation and efficiency. On the basis of this analysis, maintaining the pallet
system can be recommended.
Phosphoketolase, a Neglected Enzyme of Microbial Carbohydrate Metabolism
Authors: Rohr Lukas M. , Teuber Michael , Meile Leo
Published: June 2006

Phosphoketolases are thiamine diphosphate (ThDP) dependent enzymes of the phosphoketolase (PK) pathway of heterofermentative and facultatively homofermentative lactic acid bacteria and of the fructose 6-phosphate shunt of bifidobacteria. PK activity was also measured in protein extracts
of other microorganisms including yeasts. The dual substrate xylulose 5-phosphate/fructose 6-phosphate phosphoketolase (Xfp) from the 'probiotic' Bifidobacterium lactis was purified, and its encoding gene (xfp) was cloned and sequenced. Comparisons with public databases revealed
an unexpectedly wide spread of more than 30 homologous xfp sequences in the kingdom of the bacteria, but not of the archaea. We assigned amino acid motifs typically found in PKs. Two of them (G-P-G-H-G and E-G-G-E-L-G-Y, respectively) discriminate PKs from transketolases, which have
at least one ThDP binding site in common. On the basis of further comparative analyses we conclude that the PK prevalence among diverse organisms is due to longitudinal and not horizontal gene transmission.
Verifying the Chiral Switch of the Pesticide Metolachlor on the Basis of the Enantiomer Composition of Environmental Residues
Authors: Poiger Thomas , Müller Markus D. , Buser Hans-Rudolf
Published: June 2006

Racemic metolachlor is currently being replaced by S-metolachlor, the herbicide enantiomerically enriched with the biologically active (S)-isomers. This 'chiral switch' is expected to reduce the amount of pesticide released into the environment as well as potential side-effects
on non-target organisms. The switch is also expected to result in lower environmental concentrations and in a changed enantiomer/stereoisomer composition of the residues. To verify this switch, the enantiomer composition of metolachlor residues from a lake (Baldeggersee, Switzerland) receiving
inputs from agricultural activities was measured from 1997 through 2001. Enantioselective GC-MS analyses indicated that pre-1998 inputs into the lake were from the racemic compound. In contrast, more recent inputs showed a clear excess of (S)-isomers, and eventually (2000/2001) consisted
almost entirely of the new S-metolachlor. The data document the application of enantio-selective analysis in environmental studies to apportion the relative contributions of old (racemic) and new (enantioenriched) herbicide on the basis of the enantiomer/stereoisomer composition. The
data also show a rapid environmental response to the changed composition of a herbicide. In terms of absolute concentrations no direct evidence could be obtained for the replacement because of year-to-year variations in the inputs likely as a result of intensive rainfall during the application
periods.
University of Applied Sciences, Bern / Swiss College of Agriculture, Zollikofen – Food Technology Specialising in Dairy Processing
Authors: Bisig Walter
Published: June 2006

The University of Applied Sciences Bern offers at the Swiss College of Agriculture Zollikofen internationally recognized modern modular studies in dairy and food processing technology. Courses in dairy business and management are included and prepare for challenging positions on the
executive level in the dairy and food industry. In applied research and development, projects are carried out in collaboration with the dairy industry and other partners such as the Swiss Dairy Research Station or the Swiss Federal Institute of Technology (ETH). Post-formation courses allow
professionals to keep up to date with evolving knowledge.
Furan Fatty Acid Photooxidative Degradation Products in Dried Herbs and Vegetables
Authors: Sigrist Isabelle A. , Manzardo Giuseppe G.G. , Amadò Renato
Published: June 2006

The influence of light exposure of dried herbs and vegetables on the formation of dimethyl furan fatty acid (DiMeFFA) photooxidative degradation products such as 2,3-butanedione, 2,3-octanedione, 3-methyl-2,4-nonanedione (MND), 3,4-dimethyl-5-pentyliden-2(5H)-furanone (bovolide) and
3,4-dimethyl-5pentyl-2(5H)-furanone (dihydrobovolide) was investigated. To our knowledge, the occurrence of these compounds in tarragon, dill, basil, chervil, chive, leek, savory and onion has hitherto not been reported. The flavour fraction was isolated by simultaneous distillation extraction
and analysed by GC-MS. The flavour compounds were determined in relation to the exposure time as peak area ratio to an internal standard.
Institute of Food Science and Nutrition ETH Zürich
Authors: Hurrell Richard F. , Amadò Renato , Escher Felix , Teuber Michael , Windhab Erich
Published: June 2006

The Institute of Food Science and Nutrition consists of five laboratories: the Laboratory of Food Chemistry and Food Technology, the Laboratory of Food Process Engineering, the Laboratory of Food Microbiology, the Laboratory of Food Biotechnology, and the Laboratory of Human Nutrition.
Six professors co-ordinate the teaching programme for the undergraduate course in Food Science and each has his own focussed research programme. In addition the Laboratory of Human Nutrition co-ordinates a one-year postgraduate diploma in Human Nutrition. The following review describes the
teaching and research programmes, and selected projects.
University of Applied Sciences Vaud
Authors: Louvier Didier
Published: June 2006

The Packaging Laboratory, one of the laboratories of the mechanical engineering department of the University of Applied Sciences Vaud is also a member of the HES-SO competence group REAL TECH 'Food Production & Environmental- and Chemical Technologies'. The Packaging Laboratory,
ISO 9001 certified, develops activities in packaging technology such as applied research and development in the area of Interaction Product-Packaging; transfer technology like packaging material and complete package characterisation and also development of new packages or optimisation of actual
packages.
Defoamers in the Coatings Industry
Authors: Frank Albert , Scholz Wilfried
Published: June 2006

Foam bubbles can be a very severe problem in all kinds of coating systems. Mechanisms of foam stabilization and mechanisms of defoamers are briefly reviewed. The chemistry of different defoamer classes (mineral oil defoamers, silicone defoamers, silicone-free polymeric defoamers) together
with their typical application areas are discussed. Information about defoamer selection and evaluation methods is given.
Organic Thickeners for Water-Borne Paints
Authors: Bieleman Johan H.
Published: June 2006

Thickeners are used in paint systems to achieve particular rheological properties such as shear-rate dependent behavior, to control the viscosity at low and high shear rates, sag resistance and application viscosity. This contribution addresses the use and application of thickeners
in water-borne paints.Examples of successfully used types of thickeners are the cellulose and PUR-thickeners. Specific compositions, features and benefits of both types are explained in detail.
Silicone Additives for Paints and Coatings
Authors: Bubat Alfred , Scholz Wilfried
Published: June 2006

Silicone additives are a very widely used type of additive in coatings. Their main feature is the reduction of the surface tension of the liquid coating. Due to this very specific property they are successfully used to overcome surface defects like cratering, poor wetting and others.
In addition to this, silicone additives can also enhance the surface slip of a coating, which can be used e.g. to improve the scratch resistance of the surface. The chemistry of the silicone additives and the relationship between chemistry and performance are discussed in this paper.
Photolatent Catalysts
Authors: Dietliker Kurt , Birbaum Jean-Luc , Hüsler Rinaldo , Baudin Gisèle , Wolf Jean-Pierre
Published: June 2006

Although radiation curing is an established technology used in many industrial manufacturing processes, new applications and technical challenges stimulate the development of tailor-made photolatent catalysts. The development of a new bisacylphosphine oxide (BAPO) photoinitiator enables
the efficient curing of coatings stabilized with a light stabilizer package consisting of a UV-absorber and a hindered amine light stabilizer (weather-resistant coatings for outdoor applications). Tailor-made photolatent catalysts represent a key feature in the development of new electronic
applications like laser direct imaging for the production of printed circuit boards, color filters for liquid crystal displays used in computer flat screens and chemically amplified photoresists for microelectronics.
Driers
Authors: Bieleman Johan H.
Published: June 2006

Paints and other coating systems form a solid layer during the film-forming process where different physical and chemical processes are important.Oxidative drying is a process in which the evaporation of solvents is followed by an oxidation process of the unsaturated binder under
influence of oxygen in the air. This oxidative drying process is accelerated by the addition of catalysts, referred to as driers.
Advances in Catalysis for Organic Coatings
Authors: Blank Werner J.
Published: June 2006

The industrial coating market is undergoing substantial changes. These changes are driven predominately by environmental regulations. The reduction in organic solvent content and the elimination of certain heavy metals and toxic compounds in industrial coatings are major priorities.The
development of powder, waterborne, high solids or solvent-free coatings also requires catalyst systems with different reaction profiles.
Role and Importance of Chemical Engineering in the Specialty Chemicals Industry – A Point of View from Process Development
Authors: Doulakas Lukas , Larpin Pascal , Maire Horst , Menoud Laurent
Published: June 2006

Chemical engineers offer many skills perfectly in line with the requirements of the specialty chemicals industry, especially within process development. One of the main tasks of this department is to recruit and train young talent. A chemical engineer helps in defining new processes,
improving established products and solving EHS (environment, health and safety) issues. Thus, the chemical engineer takes an active role in the main stages of a product life cycle and fosters through his communication skills cooperation with other colleagues working in different fields, such
as production & engineering, product management, technical services. In order to fulfill the industry requirements, the Higher Institutes of Technology are encouraged to continuously offer the best education in chemical engineering.
Electrochemical Promotion of Catalysis
Authors: Fóti György , Bolzonella Ivan , Eaves Justyna , Comninellis Christos
Published: June 2006

Recent progress made in our laboratory in the field of electrochemical promotion of heterogeneous catalytic gas reactions is presented. The phenomenon consists of non-Faradaic modification of the catalytic reaction rate as the result of electrochemical polarization of the interface
between the catalyst and the solid electrolyte support. Two main aspects are addressed, the description of the phenomenon and the development of bipolar cell configurations suitable for practical applications. It is shown that the necessary condition to achieve electrochemical promotion is
the formation of a double layer at the catalyst/gas interface by mechanism of ion backspillover from the solid electrolyte support. Electrochemical promotion is only feasible in an adequate temperature range, limited by the mobility and the lifetime of the promoting ion, and it is favored
by high porosity and low film thickness of the catalyst. On the application side, two new cell designs have been developed, a ring-shaped and a multiple-channel configuration, both operated in bipolar polarization mode. The ring-shaped cell is shown to be almost free of current bypass. Feasibility
of electrochemical promotion is successfully demonstrated with both configurations. Realization of efficient bipolar cell configurations for electrochemical promotion is very promising in view of future applications in dispersed catalytic systems.
Supercritical Calorimetry: An Emerging Field
Authors: Lavanchy Frédéric , Fortini Sophie , Meyer Thierry
Published: June 2006

Calorimetry (adiabatic, isothermal, differential, oscillating or acoustic) is generally based on heat-flow measurements of the studied system. Most of its applications are dedicated to kinetic-parameter determination, safety studies and process optimization, phase equilibrium and phase
transition studies. Heat flow calorimetry on the lab scale is currently limited to low viscosity fluids. An emerging new field is concerned with the use of calorimetry in the presence of supercritical fluids as solvent reaction, which will be named supercritical calorimetry. Supercritical
carbon dioxide (CO2sc) represents an increasingly interesting media for a wide variety of reactions. To fulfill this need, a special supercritical calorimeter has been developed in collaboration with Mettler-Toledo, Schwerzenbach, CH and some preliminary results are presented.This
paper explores supercritical calorimetry applied to the intrinsic properties of carbon dioxide in the liquid, gas and especially supercritical phase as well as applications and theory related to reaction calorimetry. The CO2sc heat capacity (cp) is measured over the range
of 33–112 °C and 77–206 bar using a reaction calorimeter (RC1e, Mettler-Toledo) coupled with a high-pressure HP350 metallic reactor. Measured values are compared to theoretical values obtained from Wagner and Span's equation of state. 3D representations of the predicted values
for heat capacity, density and sound speed of carbon dioxide in the fluid phase are presented.
On Risk Acceptance in the Industrial Society
Authors: Stoessel Francis
Published: June 2006

The public, and society in general, is concerned by risks arising from technological projects and industrial activities. Responsible handling can only be achieved if the required knowledge about the hazards, and their consequences, is available in the industry and can be communicated
to the public. Chemical industries occupy a special position in this context, since accidents, even if seldom, may have a strong impact on the public.One possible way to achieve acceptance is education and information, which facilitate communication between the different parties. Some
experiences in the education of professionals and risk communication in the chemical process industry will be presented.
Recombinant Protein Expression at the Zurich University of Applied Sciences Winterthur
Authors: Zaborosch Christiane
Published: June 2006

In recent years recombinant enzymes have found widespread application in industrial uses ranging from organic synthesis to food industry. Recombinant proteins, including some enzymes, are nowadays used in the clinic to treat a broad spectrum of diseases. The elucidation of the human
genome and current efforts in functional genomics and proteomics will greatly increase the number of therapeutic proteins. This article presents the R&D activities in the biochemistry lab at the Zurich University of Applied Sciences Winterthur, which recently has initiated a focus on recombinant
protein expression.
Hair Analysis: A Powerful Tool for the Screening of Drugs of Abuse
Authors: Girod Christèle , Staub Christian
Published: June 2006

Nowadays, the analysis of drugs of abuse in hair has become more and more important in most laboratories dealing with forensic toxicological analysis. In fact, hair analysis is considered to be complementary to urine analysis.In our laboratory, such analyses were first performed
in 1995. Since then requests for hair analysis have increased and have become routine.A method was developed to analyze most drugs of abuse. This method consists of four important steps: Sample preparation, hydrolysis, automatic solid-phase extraction and gas chromatography-mass spectrometry
analysis. Particular care has to be taken during sample preparation and in the interpretation of the analytical results. Two other methods were developed, one to confirm consumption of cocaine by the identification of metabolites and to avoid the risk of false-positive results and another
to follow subjects under medical heroin treatment.
Analysis of Cannabinoids in Hemp Plants
Authors: Giroud Christian
Published: June 2006

In 2001, guidelines concerning cannabis were issued by the Group of Forensic Chemistry of the Swiss Society of Forensic Medicine. These guidelines deal with the sampling of Cannabis plants and their processing before analysis. Some recommendations are also suggested for the determination
of ?9-tetrahydrocannabinol (?9-THC). In this paper, the biosynthetic pathway of ?9-THC is presented and the putative ecological function of the cannabinoids discussed. The taxonomy and botany of the hemp plant are also considered. The influence
of age, sex, and plant part on the accumulation of ?9-THC is discussed. The need for criteria aimed at the distinction between fiber hemp and cannabis belonging to the drug type is especially emphasized. The current Swiss situation and legislation are briefly presented. Furthermore,
the sampling of cannabis material, its processing and analysis are described, alternative strategies for the characterization of hemp exhibits are also presented.
The Application of LC-MS in Forensic Toxicology
Authors: Dussy Franz E. , Stäubli Cornelia Hamberg , Briellmann Thomas A.
Published: June 2006

Analyses by LC-MS are of increasing importance in forensic toxicology and related fields. Some specific applications are discussed including the analysis of some drugs of abuse and other toxicologically highly relevant drugs like benzodiazepines, buprenorphine, LSD, muscle relaxants
and opiate glucuronides.
New Trends in Doping Analysis
Authors: Rivier Laurent
Published: June 2006

New analytical techniques in sport doping detection have emerged over the last few years. Most of them are based on instrumental advances realized in trace analysis. As new chemicals are used without waiting for the safety analysis from the usual clinical tests, control laboratories
have been forced to develop original analytical strategies. Globally, the number of positive findings from laboratories indicates that anabolic steroids are the most abused substances. Naturally occurring compounds are currently easily available because they are labeled as food supplements.
Even the so-called pro-hormones of the steroid type are considered as nontherapeutic drug types in many countries. Mixtures of small doses of anabolic steroids or subcutaneous implants for the slow release of these active substances seem to be in frequent use and are difficult to detect in
the laboratory. As a consequence, new highly sensitive instrumental strategies based on GC-C--IRMS or LC-MS have been implemented in most official international doping laboratories. But the formal characterization of doping offences in forensic toxicological terms is not just at the
laboratory level; the legal aspects of acceptance of these new instrumental approaches also have to be covered. The way to the successful detection of these new chemicals is complex and the corresponding analytical and legal challenges are important as exemplified here by the case of testosterone.
Forensic DNA Analysis
Authors: Gehrig Christian , Teyssier Anne
Published: June 2006

Currently the method of choice in the field of forensic identity is the use of commercially available kits allowing the simultaneous analysis of several STRs in a single multiplex reaction. Several other technologies, like the sequencing of mitochondrial DNA and typing of markers on
the Y chromosome are providing forensic DNA laboratories with a new arsenal of weapons that may be used in the field of human identification. Switzerland has implemented a forensic DNA database with already remarkable results.
CHIMIA in Comparison – An Update
Authors: Zass Engelbert
Published: June 2006

The impact of CHIMIA is compared to corresponding journals.
Hybrid QM/MM Car-Parrinello Simulations of Catalytic and Enzymatic Reactions
Authors: Colombo Maria Carola , Zumstein Martin , VandeVondele Joost , Sulpizi Marialore , Spiegel Katrin , Röhrig Ute , Piana Stefano , Maurer Patrick , Magistrato Alessandra , Laio Alessandro , Guidoni Leonardo , Röthlisberger Ursula
Published: June 2006

First-principles molecular dynamics (Car-Parrinello) simulations based on density functional theory have emerged as a powerful tool for the study of physical, chemical and biological systems. At present, using parallel computers, systems of a few hundreds of atoms can be routinely
investigated. By extending this method to a mixed quantum mechanical – molecular mechanical (QM/MM) hybrid scheme, the system size can be enlarged further. Such an approach is especially attractive for the in situ investigation of chemical reactions that occur in a complex and
heterogeneous environment. Here, we review some recent applications of hybrid Car-Parrinello simulations of chemical and biological systems as illustrative examples of the current potential and limitations of this promising novel technique.