bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of activated carbon on the biological treatment of oil‐water emulsions
Authors: Martienssen M. , Simon J. 
Published: December 2004

AbstractWaste water, derived from the reprocessing of used emulsions or suspensions, contains high concentrations of emulsified mineral oil and stabilizers, as well as different additives that are needed during the treatment process.Two stirred‐tank reactors and two fixed‐bed reactors were used to study the biodegradation of these waste‐water compounds during two‐stage biological treatment. The waste water was first proceesed in an activated sludge reactor to remove easily biodegradable substances. The effluent from the first stage was treated in three parallel operating reactors: an activated sludge tank containing different amounts of powdered activated carbon (PAC, between 0 and 2%), an upflow anaerobic fixed‐bed reactor and an aerobic fixed‐bed reactor (trickling filter). The results from the continuous treatment were compared with laboratory batch experiments.About 60% of the influent TOC was reduced by the first activated sludge treatment. The removal efficiency increased to about 70% by using a second activated sludge stage. This degradation was comparable to the maximum degree of degradation measured in laboratory batch experiments. PAC addition to the second activated sludge tank resulted in increased degradation rates. The removal efficiency increased to about 76% when 0.1% PAC was added and to 96% with 1% PAC. The removal efficiency decreased to 84% when the proportion of PAC was further increased to 2%. Variations in the amount of PAC addition per unit influent volume in the range of 50 and 200 mg/l had no significant effect on the TOC removal.Degradation models based on the MONOD‐type equation were found to be in close correlation with the results obtained from batch experiments. However, the biological removal rates measured in batch experiments did not reflect the removal capacity determined in continuous operating treatment systems.
Molar growth yields of Zymomonas mobilis on glucose after the transition from anaerobic to aerobic continuous growth
Authors: Zikmanis P. , Kruce R. , Auzina L. 
Published: December 2004

AbstractAn increase in the molar growth yield (YX/S = 14.3–20.3 g/mol) on glucose (25 mM) was achieved after the transition of Zymomonas mobilis ATCC 29191 from anaerobic to aerobic steady state growth at dilution rates of D = 0.31–0.40 1/h and under oxygen‐unlimited conditions. The transfer of anaerobically or aerobically grown steady state cells into a fresh medium resulted in the higher values of YX/S. A positive correlation was established between biomass and acetaldehyde yield within the range of 5–9 mM acetaldehyde in the medium. An inhibitory effect of the exogenously added acetaldehyde (Ki = 16.7 ± 2.8 mM) on the ATPase activity was observed in vitro, using cell‐free extracts of anaerobically grown Z. mobilis. The results obtained provide evidence that the increased values of biomass yield could be explained by the redirection of ATP usage during aerobic growth of Z. mobilis.
Reduction of halogenated derivatives of benzoic acid to the corresponding alcohols by Desulfovibrio vulgaris PY1
Authors: Bock M. , Kneifel H. , Schoberth S. M. , Sahm H. 
Published: December 2004

AbstractDesulfovibrio vulgaris strain PY1 was isolated from a 3‐chlorobenzoic acid (3CBA) degrading anaerobic enrichment culture, using anaerobic Percoll density centrifugation. When grown on pyruvate (20 mM), in the absence of sulphate and under strict anaerobic conditions, this organism converted not only the co‐substrates benzoate (BA), 3‐amino‐BA and 3CBA to the corresponding alcohols but also ten other different halogenated benzoic acids, viz., 4‐Cl‐, 3‐Br‐, 4‐Br‐, 3‐I‐, 3‐F‐, 4‐F‐, 2,4‐di‐Cl‐, 2,5‐di‐Cl‐, 3,4‐di‐Cl‐ and 3,5‐di‐Cl‐BA. This was verfied with HPLC and GC/MS spectrometric analyses. The yields of the co‐substrate converted after 30 days of growth were between 20% and 88%, depending on the compounds which had been added at initial concentrations of 500 μM. Sulphate, sulphite, thiosulphate and disulphite inhibited the formation of 3‐Cl‐benzyl alcohol (3CBOH), i.e. a 97 to 99% inhibition, and nitrate and sulphur had no effect (a 7–10% inhibition). In cell‐free extracts, the reduction of 3CBA to 3CBOH required strict anaerobic conditions, pyruvate or H2 as electron donors and the addition of methylviologen (MV), FAD, FMN or ferredoxin as electron carriers. The specific activity of the reduction of 3CBA to 3CBOH in crude extract was 5.3 nmol/(mg protein min). The reaction was not inhibited by additions of sulphate or sulphite (5 mM), but was completely inhibited at concentrations of 10 mM 3CBA or 50 mM BA. A carboxylic acid reductase (aldehyde dehydrogenase), which acted on non‐activated 3CBA and was responsible for the reduction of 3CBA to 3‐Cl‐benzaldehyde, was found in the solube fraction (94% of the total activity). These results demonstrate that strain PY1 was able to effectively reduce a wide range of halogenated benzoic acids to the corresponding alcohols.
Flow cytometric monitoring of Rhodococcus erythropolis and Ochrobactrum anthropi in a mixed culture
Authors: Müler S. , Lösche A. , Mertingk H. , Beisker W. , Babel W. 
Published: December 2004

AbstractThe GRAM‐positive bacterium Rhodococcus erythropolis K2–3 and the GRAM‐negative Ochrobactrum anthropi K2–14 are capable of synergistically degrading 4‐(2,4‐dichlorophenoxy)butyric acid (2,4‐DB). The two strais execute this task in a symbiotic manner, but the nature of the interaction involved in the degradation is only partially understood as yet. An essential first step in elucidating the interaction is to be able to monitor the two strans separately, at the cellular level, within mixed populations. Therefore a method exploiting fluorescently labelled lectin probes was developed. Since Concanavalin A (Con A) binds specifically to R. erythropolis K2–3, it was selected and linked to the fluoresent dye Bodipy 630/650, which has an excitation maximum in the red part of the visible light spectrum. Forward light scatter (FSC) and DNA fluorescence from both strains were also measured to obtain simultaneous information about their physiological states. The three parameters were conveniently monitored by dual and triple excitation flow cytometry in conjunction with double fluorescent staining techniques. In addition, the strains were identified using an epifluorescence microscope. These techniques were found powerful tools for the population analysis of this mixed bacterial system.
Action as a dynamic property of the genotype × environment interation implications for biotechnology
Authors: Kennedy I. R. 
Published: December 2004

AbstractThe action resonance theory (ART), a hypothesis based on a logical extension of EINSTEIN's theory of Brownian movement, suggests that the genotype × environment interaction can be modelled as forceful encounters of the gene‐products of an organism with its environment. This model has implications for molecular and cell biology, morphogenesis, evolutionary development via mutation, the mechanism of natural selection and overall function of ecosystems, extending SCHRÖDINGER's programme for molecular biology. Action, a thermodynamic property with the same physical dimensions as angular momentum and PLANCK's quantum of action, is proposed to be reversibly generated as a result of the molecular exchange of quanta, which become resonant at equilibrium, corresponding to an optimum degree of entropy and action for living systems. Because the theory can potentially predict solutions to unsolved problems such as the folding of proteins it has strong implications for successful genetic modification of organisms and for biotechnology in general; the design of a programme of research to test this theory is proposed. A key element in this research programme, improving productivity and sustainability, would be the need to select genetically modified strains in the ecological environment or niche in which they are required to function.
A guidance for stable metallic conductivity in copper salts of N,N‐dicyanobenzoquinonediimines (DCNQIs)
Authors: Erk Peter , Meixner Hubert , Metzenthin Tobias , Hünig Siegfried , Langohr Uwe , von Schütz Jost U. , Werner Hans‐Peter , Wolf Hans C. , Burkert Rainer , Helberg Hans W. , Schaumburg Gerhard 
Published: December 2004

Communiction: Radical anion salts of 2,5‐substituted N,N'‐dicyanoquinonediimines (DCNQIs) with various counterions represent a new class of highly conducting organic materials. Among the copper salts of the DCNQIs (see figure) five new radical anion salts with stable metallic behavior are presented. A comparison of structural details with physical properties reveals their stable metallic state to be conserved by tight crystal packing, which is dependent on the size of the substituents on the DCNQIs.magnified image
Screw dislocations: The key to high critical currents in YBa2Cu3O7?
Authors: Jaeger Herbert 
Published: December 2004

Research News: Defects in high‐Tc superconductors recently observed with the aid of scanning tunneling microscopy could hold the key to increased critical current densities, a crucial requirement for power applications. The observation, by teams from the Los Alamos National Laboratory, and IBM Zurich, and origin of the defects (see Figure) are discussed.magnified image
Hexafluoroacetone in resist chemistry
Authors: Przybilla Klaus J. , Röschert Horst , Pawlowski Georg 
Published: December 2004

Photo‐and radiation‐sensitive materials are used are resists in the fabrication of memory and logic devices. The 64 MB DRAMs, scchedules for 1995, will requre feature sizes below 0.5 μm (see figure). Deep‐UV lithography is a promising method of achieving these targets meaning that new resists with faovrable transmission and bleaching characteristics in this spectral region are required. magnified image
Highly branched polymers
Authors: Kim Young H. 
Published: December 2004

Well‐defined, large dendritic molecules with branches at almost every repeat unit have recently been shown to form ordered structures such as gels and liquid‐crystalline phases. The highly branched Highly Branched Polymers polyamide shown in the Figure forms, for example, a nematic phase as a 40 wt‐% solution in amides, and as a 60 wt‐% solution forms a gel static conditions but becomes fluid under shear stress. magnified image
The synthesis and crystal structure of a liquid‐crystalline ester of 4‐carboxyphenylferrocene
Authors: Loubser Christa , Imrie Christopher , van Rooyen Petrus H. 
Published: December 2004

Incorporation of ferrocene into a liquid crystal (see Figure) results in a material which offers the potential combination of the properties of an enantiotropic liquid crystal with NLO or magnetic activity. The compound demonstrates that monosubstituted ferrocene can be used to stabilize liquid crystal phases. Its LC properties and its X‐ray structure are discussed. magnified image
Well‐aligned carbon nanotubules
Authors: Hwang Jyun‐Hwei , Hsu Wen‐Kuan , Mou Chung‐ Yuan 
Published: December 2004

The alignment of carbon nanotubules greatly influences their transport properties, for example their electrical conductivity. Since these properties are important for potential applications in electronic devices, it is desirable to be able to control nanotube morphology during synthesis. An arc production method is presented that uses copper‐mixed graphite as the positive electrode, resulting in the degree of alignment shown in the Figure. magnified image
High nuclearity magnetic clusters: Magnetic properties of a nine cobalt cluster encapsulated in a polyoxometalate, [Co9(OH)3(H2O)6(HPO4)2(PW9O34)3]16⊕
Authors: Galán‐Mascarós Jose Ramón , Gómez‐Garcia Carlos J. , Borrás‐Almenar Juan José , Coronado Eugenio 
Published: December 2004

One goal in molecular magnetism is the synthesis of clusters containing large numbers of coupled spins. In the title heteropolyanion three reconstituted Keggin like fragments [PCo3 W9O40] are assembeled to increase the spin nuclearity. The Figure shows the idealizedstructure of the Co9 cluster, illustrating the connections through oxygen and HPO⊖ groups. Magnetic measurements and EPR spectra are presented, and the nature of the cluster ground state discussed. magnified image
Room temperature synthesis of poly(2,5‐dimethoxy‐l,4‐phenylenevinylene) by the chloride sulfonium salt route
Authors: Xia Younan , MacDiarmid Alan G. , Epstein Arthur J. 
Published: December 2004

The preparation of poly(p‐phenylenevinylene) and its derivatives has until now always involved a high temperature (200–300°C) conversion of the precursor polymer (see Figure) to the target polymer—a process that will cause problems in practical device fabrication. A room‐temperature conversion method is described in which HBF4 simultaneously converts and dopes the chloride sulfonium precursor polymer to the metallic conducting form in one step. magnified image
Atomic resolution chemical analysis
Authors: Browning Nigel D. , Chisholm Matthew F. , Pennycook Stephen J. 
Published: December 2004

Chemical analysis on an atomic scales is now possible using the scanning transmissionn electron microscope. The experimental setup (Fig.) allows electron transmitted through the speciment to be collected and analyzed in a variety of ways, permitting atomic resolution microanalysis of selected atomic columns. This will indicate how bulk materials properties are influenced by the atomic structure of interfaces and defects. magnified image
Antiferroelectric liquid crystals
Authors: Nishiyama Isa 
Published: December 2004

Antiferroelectric liquid crystals (AFLCs) were often first identified as antiferroelectric several years after the discovery of a new phase. This was the case for MHTAC (see Figure). The theory of the application of AFLCs as a tristable switch is outlined and the various types of AFLC materials described: low molecular mass (one of which is now commercially available), polymeric, and dimeric systems. magnified image
Raman Scattering in Zeolites and molecular sieves
Authors: Brémard Claude , Bougeard Daniel 
Published: December 2004

The diffusion and location of guests in zeolite frameworks can be studied in‐situ using Raman spectroscopy. For example, the location and orientation of crown ethers (e.g. Na⊕ 18C6, see figure) used as templates in the synthesis of faujasite polymorphs can be studied in the framework they have helped to form, and the subsequent calcination process leading to the final zeolite can also be followed using the technique. magnified image
Scanning probe microscopy of polymeric methyltrioxorhenium
Authors: Mattner Mike R. , Herrmann Wolfgang A. , Berger Rüdiger , Gerber Christoph , Gimzewski Jim K. 
Published: December 2004

The surface of polymeric methyltrioxorhenium (poly‐MTO), which is an intercalation compound with water layers as the guest in a lamellar host lattice, is shown by scanning probe techniques to consist of randomly intersecting crystalline regions with small crystallite facets. The edges of these facets exhibit steps (see Figure), the size of which can be explained in terms of the layered structure. magnified image
Ripening and formation of microcrystals of oligo(cyclohexylidene) oxime derivative produced by spin‐coating: Atomic force microscopy study
Authors: ten Grotenhuis Erik , van der Eerden Jan , Hoogesteger Frank , Jenneskens Leonardus 
Published: December 2004

Microcrystals are formed after a ripening period when an oligo(cyclohexylidene) oxime derivative is deposited on silicon wafers by spin‐coating. Results are presented related to this behavior, including atomic force microscopy images such as that shown here of crystals that had developed 3 h after deposition of the initial soft layer. AFM and X‐ray diffraction data are compared. magnified image
Second harmonic generation with metal‐containing ferroelectric liquid crystals
Authors: Espinet Pablo , Etxebarría Jesús , Folcia César Luis , Ortega Josu , Ros María Blanca , Serrano José Luis 
Published: December 2004

The second harmonic generation (SHG) parameters for metal‐containing ferroelectric liquid crystals are reported for the first time. Some of the materials, based on the structure shown in the Figure, exhibit reasonable NLO efficiencies despite the fact that the molecules themselves do not possess well‐defined donor–acceptor arrays. magnified image
Microcontact printing with a cylindrical rolling stamp: A practical step toward automatic manufacturing of patterns with submicrometer‐sized features
Authors: Xia Younan , Qin Dong , Whitesides George M. 
Published: December 2004

Microcontant printing using self‐assembled monolayers has been extended to the patterning of large areas by the introduction of a rolling elastomeric stamp (see Figure). The procedure is described and scanning electron microscope images of silver test patterns are presented. The ability to form large areas of micropatterns rapidly is important for potential applications in sensors, microelectrode arrays, consumer electronic systems, and supports for cell cultures. magnified image
Yttrium‐doped alumoxanes: A chimie douce route to Y3Al5O12(YAG) and Y4A12O9 (YAM)
Authors: Harlan C. Jeff , Kareiva Aivaras , MacQueen Brent , Cook Ron , Barror Andrew R. 
Published: December 2004

Yttrium‐doped alumoxanes are demonstrated to be ideal precursors for ternary aluminum oxides such as yttrium aluminum garnet (YAG). The yttrium‐doped alumoxanes (see Figure), formed by the reaction of carboxylate alumoxanes with Y(acac)3 (acac = acetylacetonate), provide a chimie douce route to YAG that directly competes with the traditional sol‐gel synthesis and has the additional advantage of greater processability of the pre‐ceramic. magnified image
Microscopy of Structural Ceramics
Authors: Rühle Manfred 
Published: December 2004

The development of advanced structural ceramics, which are used in specific components working under extreme conditions, require their microstructural analysis. The microscopy of structural ceramics is reviewed, beginning with various imaging techniques. The important microstructural features of three ceramics—alumina (the Figure shows an internal sensor AFM image), zirconia, and silicon nitride—and several composites are briefly outlined. FIG.magnified image
A glass‐forming conjugated main‐chain liquid crystal polymer for polarized electroluminescence applications
Authors: Grell Martin , Bradley Donal D. C. , Inbasekaran Mike , Woo E. P. 
Published: December 2004

Electroluminescence and liquid crystallinity: these are the properties of a new spacerless conjugated main‐chain liquid‐crystalline (LC) polymer reported here. The thermal and spectroscopic properties of the new glass‐forming poly‐fluorene with octyl side chains (see Figure) are described, showing that polarized electroluminescent multilayer devices should be possible. magnified image
Mesoporous silica with micrometer‐scale designs
Authors: Yang Hong , Coombs Neil , Ozin Geoffrey A. 
Published: December 2004

A “three‐way‐templating” strategy is proposed for the growth of patterned, mesoporous silica on a gold‐covered mica substrate. A model is suggested, as shown in the Figure, involving (from bottom to top) the co‐assembly of alkanethiol‐decorated gold surfaces, alkanethiol‐surfactant hetero‐bilayers, and surfactant‐silicate assemblies. magnified image
Crystal engineering of molecular NLO materials
Authors: Wong Man Shing , Bosshard Christian , Günter Peter 
Published: December 2004

Efficient second‐order nonlinear optical materials are produced by optimizing the orientation of non‐centro‐symmetrically packed donor–acceptor chromophores. Practical approaches for inducing the favored alignment, for example incorporation of chirality into the chromophore (as shown in the Figure) and H‐bond‐induced self‐assembly of ionic or molecular aggregates, are briefly reviewed. magnified image
Adjacent reentry of folded polydimethylsilane polymer chains
Authors: Boyd Robert D. , Badyal Jas Pal S. 
Published: December 2004

How does the polymer chain fold when polymer single crystals are grown? Evidence from AFM images of the surface structure of polydimethylsilane crystals is presented that suggests the adjacent recently model, in which the chains are regularly folded. Making hairpin turns at the surface (see Figure), describes the process better than the random (switchboard) model, in which an amorphous overlayer is produced.magnified image
Solid‐state droplet laser made from an organic blend with a conjugated polymer emitter
Authors: Berggren Magnus , Dodabalapur Ananth , Bao Zhenan , Slusher Richart E. 
Published: December 2004

Lasers based on organic materials have been produced with a wide range of resonator design and in a variety of geometries. A new strategy is presented for fabricating permanently near‐spherical whispering gallery mode (WGM) lasers from a blend of PPV7 and PBD (see Figure) by a melting and resolidification process. The thresholds and quality factors of these resonators are estimated and discussed.magnified image
Room temperature growth of mesoporous silica fibers: A new high‐surface‐area optical waveguide
Authors: Huo Qisheng , Zhao Dongyuan , Feng Jianglin , Weston Kenneth , Buratto Steven K. , Stucky Galen D. , Schacht Stefan , Schüth Ferdi 
Published: December 2004

High‐quality, hexagonal phase, mesoporous silica fibers (see Figure) can be grown by the general procedure for one‐step, two‐phase, room temperature synthesis reported here. The silica fibers, which are 1–5 μm in diameter and up to 5 cm long, have excellent long‐range order, a narrow pore size distribution, and a pore volume of up to 0.78 cm3/g. The birefringent fibers can be used as high‐surface‐area optical fibers.magnified image
Novel N,N′‐bridged dithiadiazafulvalene trapped in situ as a cation radical salt with polyoxometalate: (DTDAF)2Mo6O19
Authors: Bellec Nathalie , Lorcy Dominique , Robert Albert , Carlier Roger , Tallec André , Rimbaud Christian , Ouahab Lahcène , Clerac Rodolphe , Delhaes Pierre 
Published: December 2004

A quasi‐planar dithiadiazafulvalene (DTDAF) with high electrondonating properties is reported. The chemical synthesis of a phenyl‐N,N′‐bridged DTDAF (the Figure shows an ORTEP drawing of the DTDAF⊕⊙ cation radical) is described together with the preparation of a charge‐transfer set by an situ trapping and investigations of teh structural and magnetic properties of this salt. Evidence for mixed valence states is presented.magnified image
Novel optical sensor materials based on solubilization of polar dyes in apolar polymers
Authors: Mohr Gerhard J. , Werner Tobias , Oehme Ines , Preininger Claudia , Klimant Ingo , Kovacs Barna , Wolfbeis Otto S. 
Published: December 2004

Homogenous and fully transparent optical sensor layers have been prepared by pairing anionic indicator dyes with lipophilic quaternary ammonium halides (see Figure for an example) and then dissolving the pairs in an appropriate polymer. The synthesis of six ion pairs and the characterization of the resulting materials are described, along with the mechanisms responsible fo detection of several gascous species and ions.magnified image
Surface analytical techniques
Authors: Wild R. K. 
Published: December 2004

AbstractThis review briefly describes some of the techniques available for analysing surfaces and illustrates their usefulness with a few examples. In particular, Auger electron spectroscopy (AES), X‐ray photoelectron spectroscopy (XPS), secondary ion mass spectroscopy (SIMS), sputter neutral mass spectroscopy (SNMS) and laser Raman spectroscopy are all described. In analysing a surface, AES and XPS would normally be considered first, with AES being applied where high spatial resolution is required and XPS where chemical state information is needed. SIMS and SNMS can be performed together and can detect smaller surface concentrations. Laser Raman spectroscopy is useful for determining molecular bonding. Techniques which give topographic information, such as scanning tunnelling microscopy (STM) and atomic force microscopy (AFM), have not been considered.