bluuebunny/crossref_metadata_2025 huggingface dataset:
Ethanol utilization for metabolite production by Candida utilis strains in liquid medium
Authors: Domenech F. , Christen P. , Páca J. , Revah S.
Published: December 2004

Ethanol has been reported to be a gaseous pollutant, originating from the agricultural industry. Interest in its biodegradation has increased over the last two decades. Most of the current studies have focused on its elimination by mixed cultures. This study is part of a broader project intended to utilize Candida utilis strains for gaseous ethanol elimination and to eventually bioconvert them into biomass and/or volatile metabolites. We present here the study of six strains (one from the ATCC and five from the ICIDCA collection) cultivated in a liquid medium, with initial ethanol concentrations of 16 g/l and 32 g/l. At 16 g/l, a maximum ethanol elimination rate of 0.13 g/l × h was obtained in four of the six strains (ATCC 9950, L/375–1, L/375–5 and L/375–10). This rate increased to 0.21 g/l × h with an initial ethanol concentration of 32 g/l. The L/375–5 strain was the best biomass producer (3.3 g/l) at 32 g/l, while the highest ethyl acetate production (0.80 g/l) was obtained with the L/375–1 strain. The L/375–25 and L/375–26 strains which showed very low ethyl acetate production were, by way of contrast, efficient acetaldehyde producers, with 0.54 g/l and 0.66 g/l measured in the broth. While biomass production reached its maximum after two days of culture, the production of acetic acid and ethyl acetate continued during the third day. The results for biomass and metabolite production obtained with the ICIDCA collection strains (L/375–1, L/375–5 and L/375–10) were better than those obtained with the ATCC 9950 strain, although the latter often has been reported to be particularly suitable for metabolite production.
Use of natural polymers as immobilizing agents and effects on the growth of Dunaliella salina and its glycerol production
Authors: Thakur A. , Kumar H. D.
Published: December 2004

Agar‐agar, agarose, carrageenan and calcium alginate were used for the immobilization of Dunaliella salina cells. Out of the four, agar‐agar was found to be the most effective and therefore the study was carried out on it using different pH values ranging from 6 to 10 and cell densities from 0.1 to 0.8 μg chlorophyll (chl, a) per bead to find which are is best suited for glycerol production. The maximum glycerol production of 9.2 μM/mg chl a was recorded in agar‐agar immobilized algae and this was followed by 8.4 μM/mg chl a in calcium alginate. The maximum cell number 6.2 × 109/ml and the specific growth rate (μ) of 0.80 l/day were reached at pH 8 in agar‐agar immobilized algae. It was shown that the maximum amount of glycerol was produced when the cell density was 0.8 μg chl a/ block. Changing the medium after 24 hours affected the rate of glycerol production at different pH values. Using a cell density of 0.8 μg chl a/block at 16 W/m2 light intensity increased the glycerol production in comparison with the use of free living cells.
Methylobacterium rhodesianum produces poly‐3‐hydroxybutyrate and after mutagenesis in addition exopolysaccharides
Authors: Breuer U. , Babel W.
Published: December 2004

Methylobacterium rhodesianum MB 126, a pink‐pigmented facultatively methylotrophic bacterium that uses that serine pathway for the assimilation of reduced C1 compounds, is able to produce poly‐3‐hydroxybutyrate (PHB) under certain limitation conditions. Mutants of this bacterium, which were isolated after the treatment with sodium nitrite, are impaired in their ability to synthesize PHB, but produce another polymer in addition to PHB, namely an exopolysaccharide (EPS). This paper attempts to explain this surprising behaviour.
Process engineering in biological aerobic waste‐water treatment
Authors: Gavrilescu M. , Macoveanu M.
Published: December 2004

A non‐comprehensive review of several technical developments in the field of aerobic biological waste‐water treatment engineering is carried out, considering the active role the engineers have to play in this field. This paper brings together conventional and advanced problems in the field of aerobic biological waste‐water treatment.

Such an overview of biological waste‐water treatment also precedes comments on some important aspects concerning the microorganisms responsible for waste‐water treatment as well as considerations of the application of fundamentals and kinetics to the analysis of the biological processes used most commonly for aerobic biological waste‐water treatment.

A survey of the development of the biological activated‐sludge process and some modifications are given. Some problems implied in the conventional activated‐sludge waste‐water treatment are analyzed, considering conventional processes and bioreactor models (the continuous stirred‐tank reactor model and the plug‐flow reactor models of the activated‐sludge process) as well as aerated lagoons.

Further, modifications of the activated‐sludge process are presented. These include additional details on the bioreactor progress and applications, with emphasis on aspects concerning airlift bioreactors and their variants, deep‐shaft bioreactors and reciprocating jet bioreactors which are considered as the third generation of bioreactors owing to their important advantages in design, operation and performance in waste‐water treatment. Sequencing‐batch reactors and aerobic digestion processes, including conventional aerobic digestion, high‐purity oxygen digestion, thermophilic aerobic digestion and cryophylic aerobic digestion are also reviewed.

Finally, some aspects regarding the operational factors that are involved in the selection of the reactor type are included.
Investigation of aerobic degradation kinetics of surfactants using respirometric batch experiments
Authors: Schreiner A. , Asmussen C. , Wiesmann U. , Stan H.‐J.
Published: December 2004

The mineralization of a non‐ionic alcohol ethoxylate (AEO) surfactant was investigated over the concentration range occurring in rinsing water from surfactant production processes. For this, an experimental set‐up for respirometric batch experiments was developed. The set‐up and the method were validated by experiments with glucose as the single carbon source. It was possible to calculate substrate decay from the time course of exogenously consumed oxygen during respirometric batch experiments. The kinetic coefficients calculated by respirometry showed a lower standard deviation than those calculated from emasured glucose concentrations.

The degradation mechanism of AEO was investigated by identification of metabolities, occurring during the mineralization process of AEO, using Flow Injection Mass spectrometry (FI‐MS). It was concluded that the degradation of AEO occurs in two main steps. First, the enzymatic hydrolysis of AEO into alcohol and polythylene glycol (PEG) is performed. Second, the mineralization of both substances takes place, while the mineralization of the alcohol is faster than that of the PEG. The mineralization kinetics were investigated in respirometric batch experiments. The model used is based on double MONOD kinetics for the substrates being produced by hydrolysis (μmax1 = 0.047 h−1, Ks1 = 15 mg/l DOC for alcohol; μmax2 = 0.027 h−1, KS2 = 4 mg/l DOC for PEG). The validation of the model by calculating the results obtained from measurements in a continuously operated lab scale CSTR with bacteria recycle was successful.
Increased enzymatic activities and levels of superoxide anion and phenolic compounds in cultures of basidiomycetes after temperature stress
Authors: Fink‐Boots M. , Malarczyk E. , Leonowicz A.
Published: December 2004

Selected strains of basidiomycetes (Abortiporus biennis, Trametes versicolor and Cerrena unicolor) were shown to produce enhanced extracellular peroxidase (EP), superoxide dismutase (SOD) and laccase activities following the exposure of 10‐day‐old fungal cultures to separate high and low temperature stress. The stressful conditions also caused an increase in the concentrations of phenol compounds and superoxide anion radicals in these cultures. At first, peroxidase activity was observed at 12 hours from the moment of temperature stress application. Laccase activity appeared at 96 hours after the maximum levels of superoxide anion radicals (48 h) and SOD activity (36–72 h). The concentration of phenolic substances grew steadily during the period of cultivation. These relations between laccase, SOD and EP as well as superoxide radicals and phenol levels in the environment of ligninolytic fungi seems to be important in the course of the biosynthesis or biodegradation of lignin, as the consequence of adaptation of these basidiomycetes to environmental temperature conditions.
Optimization of some parameters of solid state fermentation of wheat bran for protease production by a local strain of Rhizopus oryzae
Authors: Aikat K. , Bhattacharyya B. C.
Published: December 2004

Some parameters of the production of an alkaline protease by Rhizopus oryzae in the solid state fermentation of wheat bran were optimized. Using the optimum parameters of an inoculum age of 7 days, an incubation time of 9 days, an amount of CZAPEK‐DOX (liquid medium) of 6 ml/g bran and an incubation temperature of 33°C, an activity of 50 U/g bran was achieved. The initial pH of the CZAPEK‐DOX medium had little effect. Re‐incubation of mouldy bran with only fresh CZAPEK‐DOX yielded 3 times total activity compared to single‐cycle fermentation. As for the effect of the amount CZAPEK‐DOX medium, the water constituent contributed more to activity increase than did the salt component. The ARRHENIUS activation energies were 23 and 7.9 kcal/mole below and above the optimum of 33°C, respectively. In all the studies, along with protease production, variation of protein content and specific activity were also observed. Attempts were made to explain the effects and also gauge their implications for large‐scale production.
Polymers as Advanced Materials
Authors: Eisenbach Claus D. , Haarer Dietrich
Published: December 2004

The crucial role that polymers play in the electronics industry is just one example of how modern life has been influenced by these multi purpose materials. Development of novel polymers with new and exciting properties and their effective application requires an interdisciplinary effort. This has guided the structuring of the research effort in West Germany. One result of this has been the founding of an Institute for Materials Science in Bayreuth.
Modeling organic surfaces with self‐assembled monolayers
Authors: Bain Colin D. , Whitesides George M.
Published: December 2004

The interfacial properties of organic materials are of critical importance in many applications, especially the control of wettability, adhesion, tribology, and corrosion. The relationships between the microscopic structure of an organic surface and its macroscopic physical properties are, however, only poorly understood. This short review presents a model system that has the ease of preparation and the structural definition required to provide a firm understanding of interfacial phenomena. Long‐chain thiols, HS(CH2)nX, adsorb from solution onto gold and form densely packed, oriented monolayers. By varying the terminal functional group, X, of the thiol, organic surfaces can be created having a wide range of structures and properties. More, complex systems can be constructed by coadsorbing two or more thiols with different terminal functional groups or with different chain lengths onto a common gold substrate. By these techniques, controlled degrees of disorder can be introduced into model surfaces. We have used these systems to explore the relationships between the microscopic structure of the monolayers on a molecular and supramolecular scale and their macroscopic properties. Wettability is a macroscopic interfacial property that has proven of particular interest.
Molecular electronics—science and technology
Authors: Aviram Ari
Published: December 2004

Ari Aviram's account of the molecular electronics meeting in Kona, Hawaii is just one of this months articles which also include Ceramics in Bologna (S.‐J. Kang) and Atomic Steps on Surfaces (M. Henzler).
Materials Issues in Electronic Systems
Authors: McCall David W.
Published: December 2004

The manufacture and use of electronic systems involves an enormous amount of materials engineering work. David McCall surveys the various technologies needed to produce electronics components (see figure) and takes a look at possible future developments in this fascinating area.

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Biomaterials hightlights IV. The “state of the art”
Authors: Heimke Günther
Published: December 2004

This edition of our regular series on biomaterials focused on the progress reported at two major conferences held in September, 1989, in Heidelberg, FRG. Aspects of the use of metals, cements, ceramics, glasses and coating in hard tissue replacement are discussed along with new developments in the study of cell attachment to implant surfaces.
Solid State NMR spectroscopy in polymer science
Authors: Blümich Bernhard , Hagemeyer Alfred , Schaefer Dieter , Schmidt‐Rohr Klaus , Spiess Hans W.
Published: December 2004

The properties of solid polymers are determined to a large extent by the structure, order, and dynamics of the molecules which make up the polymers on a molecular scale as well as by the morphological domain structure involving the size and type of crystalline, amorphous and interfacial phases. Solid state NMR spectroscopy is a method particularly suited to the investigation of the properties of individual molecules since their resonance frequency depends on the structure and on the orientation of a molecular segment in the magnetic field. In addition, morphological aspects can be studied by following the spin diffusion between individual phases. This review covers NMR techniques devised recently to address such polymer specific questions.
Interdisciplinary research centres—centres of excellence or contention?
Authors: Joyce Bruce A.
Published: December 2004

British interdisciplinary research efforts have been further organized in the last few years by the founding of IRCs. The aims of these centres, the way they are awarded, funded, and managed is a topic of some debate. In this month's Editorial Essay, the Director of the IRC for Semiconductor Materials in London assesses the current position and the future of this approach.
Electroceramics: Characterization by Impedance Spectroscopy
Authors: Irvine John T. S. , Sinclair Derek C. , West Anthony R.
Published: December 2004

Electroceramics are advanced materials whose properties and applications depend on the close control of structure, composition, ceramic texture, dopants and dopant (or defect) distribution. Impedance spectroscopy is a powerful technique for unravelling the complexities of such materials, which functions by utilizing the different frequency dependences of the constituent components for their separation. Thus, electrical inhomogeneities in ceramic electrolytes, electrode/electrolyte interfaces, surface layers on glasses, ferroelectricity, positive temperature coefficient of resistance behavior and even ferrimagnetism can all be probed, successfully, using this technique.
Induction and variation of discotic columnar phases through doping with electron acceptors
Authors: Ringsdorf Helmut , Bengs Holger , Karthaus Olaf , Wüstefeld Renate , Ebert Martina , Wendorff Joachim H. , Kohne Bernd , Praefcke Klaus
Published: December 2004

Low molecular weight liquid crystals with in‐build charge transfer (CT) properties have been generated from both liquid crystalline (LC) and non‐LC disc‐like compounds by doping these electron rich species with electron acceptors e.g. TNF. The influence of CT interactions on the columnar phases formed are assessed and the phase behavior of the columnar systems with varying acceptor contents reported.
Synthesis and properties of viologen functionalized poly(3‐alkylthienylenes)
Authors: Bäuerle Peter , Gaudl Kai‐Uwe
Published: December 2004

Viologen functionalized conducting polymers synthesized from the substituted monomers whon in the figure are interesting materials with possible applications in redox or electrocatalysis, sensors, and electrochromic devices. Monomers and polymers with various numbers of methylene groups separating the thiophene units and the redoxactive viologen moieties have been synthesized and characterized.

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Langmuir–blodgett films for electronic applications
Authors: Tieke Bernd
Published: December 2004

The present status of research on Langmuir‐Blodgett (LB) films is outlined in relation to specific properties for electronic applications. The fundamentals of LB films are briefly described such as preparation techniques, film types, structure, and suitable compounds for functional amphiphiles, unconventional film‐forming materials and polymers. Stress is laid on novel functional LB films exhibiting either photochemical and thermal reactivity, or electroactive properties such as electrical conduction, redox activity, electrochromism, nonlinear optical properties, and pyroelectric activity. The current status of LB films with regard to electronic applications is described, e.g. as photo‐ or e‐beam resists, information storage systems, barrier layers, chemisensors, frequency converters and modulators, optical switches, guided wave structures or infrared sensors. Prospects for future molecular electronic devices are also briefly discussed.
High‐temperature superconductivity: Four years since Bednorz end Müller
Authors: Grant Paul M.
Published: December 2004

The history, development, theory, experiment and applications of high‐Tc superconducting materials are covered in depth by one of the leading figures in the area. The importance of patents to the inductrial effort is analyzed and the possible mechanisms responsible for the phenomenon described.
Solar induced hydrogen production in a semiconductor septum electrochemical photovoltaic cell
Authors: Tien H. Ti
Published: December 2004

Seawater + visible light → electricity and hydrogen. This is the reaction which occurs in a solar cell recently developed by a group at the Michigan State University, based on an n‐type polycrystalline cadmium selenide (CdSe) electrode (see figure). The work is based on experience gained in research into membranes for artificial photosynthesis.

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Highly polarizable zwitter‐ions for nonlinear optics: Synthesis, structure and properties of phenoxide‐pyridinium derivatives
Authors: Bacquet Gérard , Bassoul Pierre , Combellas Catherine , Simon Jacques , Thiébault André , Tournilhac Francois
Published: December 2004

High hyperpolarizabilities can be obtained in nonlinear optical materials through the incorporation of electron donor and acceptor moieties. This communication reports a convenient synthetic route (see figure) to materials containing both phenoxide and pyridinium units which are among the most favorbale gropus for this purpose. The hyperpolarizabilities are examnined and the crystal structure of 1 a is discussed.

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Synthesis of molecular organometallic composites: Polymerization of vinylferrocene in a porous polymer matrix
Authors: Arshady Reza , Corain Benedetto , Lora Silvano , Palma Giancarlo , Russo Umberto , Sam Felix Okon , Zecca Marco
Published: December 2004

Polymer‐organometallic composites are potentially suitable for catalyst development. 3.8% Fe has been incorporated into a composite (see figure) by the copolymarization of vinyl ferrocene, dimethylacrylamide and methylene bisacrylamide within a preformed porous polymeric matrix, a metal incorporation significantly higher than that reported for materials obtained by graft polymerization.

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Plasma processing of surfaces
Authors: Möhl Wolfgang
Published: December 2004

Plasma techniques are employed in microlithography and in other surface modification methods. The increasing need for sources of “clean” plasma, uncontaminated with metal, has led to the development of new technology which outperforms the traditional Kaufman‐type source. The techniques are compared and some of the possible applications examined.
Materials in electronics and electrical engineering
Authors: Weyrich Claus
Published: December 2004

Siemens activities are founded on a broad base of materials expertise. Claus Weyrich, head of materials science and electronics at the Siemns laboratories in Munich and Erlangen, introduces this special “Siemens Research '90” issue by describing the important criteria for the introduction of new materials and their development, and takes a look at future requirements for materials, especially in the electronics area.
Polymers and light in bad nauheim
Authors: Haarer Dietrich
Published: December 2004

Dietrich Haarer reports on the “Polymers and Ligh” meeting in Germany and Herbert Jaeger reviews his visit to a “Thin Film Superconductors” conference held recently in Colorado.
Protein interactions with ordered lipid films: Specific and unspecific binding
Authors: Ahlers Michael , Blankenburg Rainer , Haas Heinrich , Möbius Dietmar , Möhwald Helmuth , Müller Wolfgang , Ringsdorf Helmut , Siegmund Hans‐Ulrich
Published: December 2004

Communication: Membrane‐bound receptors improtant in biochemistry and medicine can be modeled using mono‐ and multilayer amphiphilic LB films. Proteins bound to the films (see figure) can possess either enzymatic activity or a specific binding capability that can be used in biological tests. Here, the interactions between polypeptides such as cytochrome C, insulin, and concanavalin A, and several types of films are evaluated.

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Photosensitive polymeric amphiphiles: Irradiation‐induced structural changes in langmuir–blodgett multilayers
Authors: Arndt Thomas , Häußling Lukas , Ringsdorf Helmut , Wegner Gerhard
Published: December 2004

Communication: Microstructure control in LB films, for example with lithography, is essential for potential applications in electronics. The photochemically induced reaction shown in the figure, where the highly ordered, densely packed film cleaves to form a cationic polymer (right) and a hydrophobic side chain (left) could be exploited to produce domainsized features on flood exposure with UV light.

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Organic Solar Cells
Authors: Wöhrle Dieter , Meissner Dieter
Published: December 2004

Review: The conversion of sunlight into electricity can be achieved using a solar cell and is one of the most attractive future soruce of energy. Silicon‐based cells, while quite efficient, are difficult and expensive to produce, a fact that drives up the cost of electricity produced using them. The alternative, organic‐based cells (see Figure) have the potential advantages of ease of processing and cheapness if their efficiency can be brought up to reasonable levels. Recent progress made and future targets in this field are reviewed.

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Selective low‐temperature chemical vapor deposition of copper from (hexafluoroacetylacetonato)copper(I)trimethylphosphine, (hfa)CuP(Me)3
Authors: Kodas Toivo T. , Shin H.‐K. , Chi K.‐M. , Hampden‐Smith Mark J. , Farr John D. , Paffett Mark
Published: December 2004

Communication: The deposition of smooth, dense, fine‐grained, low resistivity copper films has been achieved at temperatures as low as 150°C from an organometallic precursor. It is suggested that the films (see figure) are formed as the result of thermal disproportionation of the precursor without decomposition of the ligand. Substrate‐selective deposition at rates of over 1000 Åμmin is demonstrated.

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Highly effective surfactants with low hemolytic activity
Authors: Riess Jean G. , Pace Simonne , Zarif Leila
Published: December 2004

Communication: Fluorochemicals show potential as highly surface‐active but non‐hemolyzing surfactants, an important combination of properties for biomedical applications such as blood substitutes and contrast agents. Hydrocarbon‐based surfactants suffer from the disadvantage that as the length of the hydrocarbon chain (and therefore surface activity) increases, cell‐destruction (hemolysis) also increases. The fluorinated srufactants, however, exhibit the opposite effect, an increase in chain length and surface activity leading to reduced hemolysis.
Trisubstituted decacyclene derivatives: Bridging the gap between the carbonaceous mesophase and discotic liquid crystals
Authors: Keinan Ehud , Kumar Sandeep , Moshenberg Reuven , Ghirlando Rodolfo , Wachtel Ellen J.
Published: December 2004

Communication: Discotic mesogens with C3 symmetry (see figure) are shown to form the basis of a chemically stable low‐temperature model for the carbonaceous mesophase, a key intermediate in the production of coke and graphite via the carbonization of organic precursors. The synthesis and properties are reported.

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Ladder Polymers: The new generation
Authors: Schlüter Arnulf‐Dieter
Published: December 2004

Review: Polymers with high thermal, mechanical, and chemical stabilitybased on a ladder‐type structure (see figure), have suffered in the past from insolubility or infusibility. A new strategy for the controlled synthesis of processible ladder polymers, based on Diels‐Alder polymerization is reviewed, and the polymers considered as precursors to graphite ribbons, materials predicted to have properties lying between graphite and single‐stranded polyacetylene.

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New European funding for advanced materials research: Call for proposals in ESPRIT
Authors: Hussla Ingo , Us Natasha
Published: December 2004

Essay: The ESPRIT programme of the European Community has recently issued a call for proposals for the next round of funding for which over 5 billion ECU have been earmarked. Some of the research which has received support from the Programme in the past is described and the conditions for application for the next round (which closes on October, 14, 1991) are presented.
TiFeCr/NaM—a new hydrogen‐storage material
Authors: Xu Wenyang , Li Jinping , Dong Jinxiang
Published: December 2004

Communication: A composite which combines the hydrogen‐storage capabilities of TiFeCr alloys with the selective absorption characteristics of mordenite zeolites (NaM) is reported. The new material even exhibits a higher hydrogen‐storage capacity than the parent alloy and therefore could be of considerable technological interest.
Steel‐based corporate diversification
Authors: Nomura Hiroshi
Published: December 2004

Essary: Kawasaki Steel is one of the world's largest steel producing corporations. Market pressures over the last few years have encouraged the company to diversify into the high technology sector in order to remain competitive. The Director of the company's high technology laboratories in Japan traces recent developments and outlines the aims of the company in, for example, electronics.
Molecular imaging by Raman microscopy
Authors: Batchelder David N. , Cheng Chunwei , David Pitt G.
Published: December 2004

Research News: Raman microscopy combines the ability to indentify molecular species in a sample and to determine the location of these species within the sample. An example of the application of the technique is shown in the figure where a plasma‐deposited diamond film is imaged, the lighter areas indicating the presence of crystalline diamond. The developement of the technique and some of its applications are outlined.

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A fully conjugated ‘dimeric’ BEDT‐TTF system;[l] synthesis, crystal structure, and electrical properties
Authors: Adam Martin , Bohnen Angelika , Enkelmann Volker , Müllen Klaus
Published: December 2004

Communication: The low dimentionality of the charge‐carrier transport in conducting BEDT‐TTF radical cation salts usually results in a metal‐insulator transition. The extended BEDT‐TTF derivative presented here contains two TTF moieties in full π conjugation and is the result of research aimed at increasing the dimentionaly of the system. The synthesis and electrochemical properties of the new doner are reported.
Selective transport of anions across liquid membranes using the ferrocenium/ferrocene redox couple
Authors: de Santis Giancarlo , di Casa Michela , Fabbrizzi Luigi , Licchelli Maurizio , Pallavicini Piersandro
Published: December 2004

Communication: Anions can be selectively transported across a bulk liquid membrane by the 1‐hexadecylferrocenium ion through a process driven by a chemically generated redox potential gradient. The liquid membrane, a solution in dichloromethane, acts as a filter for anions, being permeable to perchlorate ions and impermeable to choride ions. The alkyl substitution of the ferrocenium ion serves to confine the ion to the membrane phase.
A sober and accurate assessment
Authors: Bianconi Patricia A.
Published: December 2004

Talking point: In our September issue, Rustum Roy and John Maddox provided two different points of view concerning a research paper published in Nature. The author of that paper, which is concerned with the synthesis of inorganic/organic composites in which the inorganic crystals display controlled size, shape, and orientation, now presents her opinion, explaining the aims and background to the work, and addressing the criticism levelled both at her work and the field.
Precursor compounds for organic metals and nonlinear optical devices from carbohydratederived hydroxymethylfurfuraldehyde:[1, 2] Furanoid electron donors and push/pull substituted compounds
Authors: Schöberl Ulrich , Salbeck Josef , Daub Jörg
Published: December 2004

Non‐food applications of industrially accessible low‐molecular‐weight carbohydrates are examined. Available from, for example, sucrose, starch, or cellulose, the carbohydrates are shown to form the basis of conducting charge‐transfer salts or materials with nonlinear optical properties. The compound shown in the figure, for example, which is based on a furan unit obtainable from glucose, is shown to form a stable charge‐transfer salt with TCNQ exhibiting a powder conductivity of 10−2 S/cm at room temperature.

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Materials Research Concepts in the Chemical Industry
Authors: Aldinger Fritz , Cherdron Harald , Kühlein Klaus , Riggs John
Published: December 2004

Structural and functional polymers and ceramics are the main activities of the chemical industry in the materials area. The general concepts and considerations in the development of new materials are discussed from the point of view of research directors from the Hoechst group. In descrribing the various approaches to materials the opportunity is taken to intrroduce the following articles which deal with the individual topics in more detail.
Microparticles from biodegradable polymers
Authors: Ahlers Michael , Krone Volker , Walch Axel
Published: December 2004

Intelligent routes of delivery for pharmaceutical productss are provided by the application of biodegradable polymers. Microparticles formed from the polymers can be used to protect sensitive or unstable protein or peptide‐based drugs enabiling them to be delivered to the desired site in the body before being released. The microparticles can take on a number of shapes, an example of which is shown in the figure.

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A ferroelectric liquid crystal dimer: Synthesis and properties
Authors: Marcos Mercedes , Omenat Ana , Serrano José Luis , Sierra Teresa , Ezcurra Amaya
Published: December 2004

Chiral liquid‐crystalline phases are of great interest due to their nonlinear optical and ferroelectric properties. Side‐chain FLCPs (ferroelectric liquid crystal polymers) are known but no main chain FLCPs have been reported, only a limited number of FLC dimers which are used as models for the main chain compounds being known. Here, a new dimer is presented (see figure) which exhibits a high spontaneous polarization.

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SHS technology
Authors: Merzhanov Alexander G.
Published: December 2004

The impact of controlled exothermic reactions on the sphere of materials processing is discussed. Although self‐propagating high‐temperature synthesis (SHS) has applications in sintering, densification, metallurgy, welding, coatings, and powder synthesis it is estimated that only 3–5% of its possible uses have been realized. Present applications are reviewed.
High‐power Nd:YAG lasers
Authors: Wittrock Ulrich
Published: December 2004

The output power, efficiency, and beam quality of high‐powerd Nd: YAG lasers can be improved by employing a device configuration which improves pumping efficiency. By locating the pumping source within the cavity of a tube laser, the pumping radiation is forced to pass through the crystal more effectively thus increasing efficiency.

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Polymerization of methyltrioxorhenium(VII) organometallic oxides as precursors for oxide ceramics
Authors: Herrmann Wolfgang A. , Fischer Richard W. , Scherer Wolfgang
Published: December 2004

Polymerization by acid‐induced aggregation, a process that was previously unknown in organometallic chemistry, is shown to occur in methyltrioxorhenium(VII). The resulting polymer, an oxide ceramic precursor, undergoes an unusual depolymerization: in the weeks following compression of a pellet of the polymer, the surface becomes covered with large single crystals of the monomer (see figure). This is the first example of the specific crystallization of a metal‐organic compound from the solid state by application of pressure.

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Anisotropic gels in liquid crystal devices
Authors: Hikmet Rifat A. M.
Published: December 2004

Anisotropic gels are a novel type of material obtained by in situ polymerization of liquid crystal (LC) molecules in the presence of low molecular weight conventional LC molecules without reactive groups. The resulting anisotropic network (see figure) possesses the structure of the original LC mixture. These gels offer new possibilites for the manufacture of LC devices, including both active and passive optical components.

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Extended homologues of tetrathioalkyl‐tetrathiafulvalenes
Authors: Müllen Klaus , Scherer Ute , Shen Yong‐Jia , Adam Martin , Bietsch Werner , Von Schütz Jost Ulrich
Published: December 2004

Tetrathiafulvalene radical cation salts are organic‐based conductors where an increase of the dimensionality of the conducting process leads to a stabilization of the metallic state. Donor molecules of the type shown in the Figure should increase this dimensionality by extending the π conjugation of the system. The synthesis of the new donor and the electrical properties of its salts are presented.

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Covalent binding of glucose oxidase to functionalized polyazulenes. The first application of polyazulenes in amperometric biosensors
Authors: Schuhmann Wolfgang , Huber Johanna , Mirlach Albert , Daub Jörg
Published: December 2004

The covalent binding of enzymes to the surface of electrodes has been shown to lead to amperometric enzyme electrodes with fast response characteristics. New C‐2 substituted azulenes offer a viable alternative to the use of pyrrole derivatives as electrode materials as they easily form thin films of conducting polymeric material on electrochemical doping (see Figure).

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Science publishing needs a reformation
Authors: Roy Rustum
Published: December 2004

In a response to the previous article, Rustum Roy, Founding Director of the Penn State Materials Research Laboratory, explains the novelty of the new method of diamond synthesis, and expands on his claim that science publishing, especially the way new research results are refereed or otherwise assessed, needs a reformation.
Advanced materials research at NTT
Authors: Fujimoto Masatomo
Published: December 2004

This special issue of Advanced Materials concentrates on the research and development activities of the Japanese telecommunications and electronics company Nippon Telegraph and Telephone (NTT). The work described briefly here, ranging from MBE and MOCVD through computer‐aided materials design to optical fibers, liquid crystals and high‐Tc superconductors, is presented in more detail in the following articles.
Compound Semiconductor Ultrathin Films— characterization and control of growth
Authors: Inoue Naohisa
Published: December 2004

The unprecedented control of ultra‐thin‐film properties required by advanced device concepts has led to the development of novel techniques for both growth and characterization, including cathodoluminescence microscopy, scanning tunneling microscopy and in situ optical diagnostics. In situ electron microscopy can be used to directly observe transient growth processes, revealing unexpected features such as the lateral growth of Ga layers around droplets when the surrounding surface is covered with As (Figure).

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Computer‐Aided Materials Design for semiconductors
Authors: Ito Tomonori , Ohno Takahisa , Shiraishi Kenji , Yamaguchi Eiichi
Published: December 2004

Computer‐aided materials design for semiconductors is reviewed. Reliable predictions are possible for a wide range of problems, such as the behavior of various heterovalent atomic species in III‐V semiconductors, including C (conduction type), Si (DX‐center), Ge (GaAs/Ge superlattices), S, Se and Te (passivation of GaAs surfaces), by using such computer‐aided calculation techniques as pseudopotential methods.
European polymer science—future research strategies
Authors: Koningsveld Ronald , Wegner Gerhard
Published: December 2004

Research development on a European scale is a recognized requirement if European efforts in many areas of science and technology are to keep pace with competition from overseas. Polymer science is no exception. At a recent European Polymer Federation Conference a round‐table discussion was held on “Eurotopics” such as Optoelectronics, Supramolecular Architectures, Computer‐Aided Polymer Research, Processing, Combustion, and Colloids. here, progress is summarized and future Europe‐wide activities presented.
Effects of surface topology and highly anisotropic polymer LB films on liquid crystal alignment
Authors: Suzuki Masayoshi , Ferencz Andreas , Iida Shigeki , Enkelmann Volker , Wegner Gerhard
Published: December 2004

Controlling molecular orientation, especially in liquid crystals, is of particular current interest for example in the development of display technology. Here it is shown, through studying various LCs (e.g. PCH5 or Oil red O, see figure) and orientation techniques, that the alignment of the polymer chains in the alignment layer plays the most important role in controlling the orientation of the liquid crystals.

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Intercalation of water‐soluble polymers in V2O5 xerogel
Authors: Liu Yu‐Ju , DeGroot Don C. , Schindler Jon L. , Kannewurf Carl R. , Kanatzidis Mercouri G.
Published: December 2004

The direct intercalation of polymer molecules into inorganic hosts has proved difficult due to the dimensions of the polymers. Here, new polymer/V2O5 intercalation compounds based on the inclusion of water‐soluble polymers such as polyvinylpyrrolidone, polypropyleneglycol, and methyl‐cellulose are reported and their physical properties discussed. This approach further facilitates the production of inclusion compounds with controlled mechanical, optical, and electrical properties.
Strengthening glasses and ceramics
Authors: Partridge Graham
Published: December 2004

Cooking pots and nuclear reactors are two widely different applications of glasses and ceramics. This breadth of utility requires materials whose properties can be tuned over a very wide range. Tuning can be achieved by varying the composition of the materials or the processing parameters or both. Strength and fracture toughness are among the most important properties of these materials in considering them for applications. Factors influencing these properties are discussed.
Nanomachining and manipulation with the atomic force microscope
Authors: Lieber Charles M. , Kim Yun
Published: December 2004

The ability to manipulate matter on the nanometer scale is a requirement for the full development of nanotechnology. Scanning probe microscopies show great promise in this respect and recent progress in the area is discussed. for example surface modification, pattern formation (e.g. the 150 nm high Harvard University symbol in the figure), and the manipulation of nanostructures.

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EPR and optical absorption spectra of reduced buckminsterfullerene
Authors: Baumgarten Martin , Gügel Andreas , Gherghel Lileta
Published: December 2004

The unambiguous identification of the various redox states of C60 is of importance in many areas of fullerene research, such as charge transfer studies between conducting polymers and C60, or the study of the distribution of charged states in solid‐state‐doped samples. This combined ESR and optical absorption spectroscopic study represents the most complete analysis of the anionic states of buckminsterfullerene, from the monoanion to the hexaanion, so far reported.
Optical Nonlinearity:Phenomena, applications, and materials
Authors: Nie Wenjiang
Published: December 2004

Rectification, inversion, modulation, harmonic generation, and heterodyning are all effects well known in the world of electronics as the essential properties of practical devices. These, and many other, related, effects have applications in optics, made possible by te development of the laser, a source of intense monochromatic light. In this article, from the viewpoint of the materials scientist, the basic phenomena and their applications are presented before and various materials in use in nonlinear optics are discussed.
Novel amorphous molecular materials: The starburst molecule 1,3,5‐tris[N‐(4‐diphenyl‐ aminophenyl)phenylamino]benzene
Authors: Ishikawa Wataru , Noguchi Kisaburo , Kuwabaru Yoshiyuki , Shirota Yasuhiko
Published: December 2004

Photo‐ and electroactive amorphous molecular materials are attractive for use in electronics, for example in pn heterojunction‐type photovoltaic devices or in electroluminescent devices. The title compound (based on that in the Figure) exhibits a high glass transition temperature, hardly crystallizing even above this temperature making it especially suitable for electronics applications.

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Semiconductor nanowhiskers
Authors: Yazawa Masamitsu , Koguchi Masanari , Muto Akiko , Hiruma Kenji
Published: December 2004

Self‐assembled nanostructures based on indium arsenide whiskers grown using molecular beam epitaxy and metal‐organic vapor phase epitaxy (see Figure) could be of use as lead wires, connecting devices in integrated nanodevices. The procedure employed to produce these features in a controlled way is described, and the possibilities of developing nanowhisker heterojunctions discussed.

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The amoeba—a flexible organism called RIKEN
Authors: Knoll Wolfgang
Published: December 2004

Two aims of RIKEN, the Japanese Institute of Physical and Chemical Research, are “to conduct comprehensive research in science and technology” and “to disseminate the results of research and new technological developments”. How RIKEN is organized and managed in order to pursue these goals is the subject of this essay, which likens RIKEN to a unicellular, multinuclear animal living in the Sea of Japan. Details are given of the Frontier Research Program, which is designed to further cooperation with the wider international research community.
Modeling the elementary steps of low‐pressure diamond deposition
Authors: Biener Jürgen , Schubert Uwe. A. , Schenk Angelika , Winter Bernd , Lutterloh Carsten , Küppers Jürgen
Published: December 2004

Low‐pressure diamond deposition from hydrocarbon/hydrogen gas‐phase mixtures was discovered over 20 years ago, but the exact deposition mechanism remained unknown. Work reported here confirms preferential graphite erosion to be the rate‐controlling step, as had been assumed by some researchers earlier, and identifies reaction pathways by which the graphitic constituents of the deposit are preferentially removed. Model systems of C:H a few monolayers thick were used to show that dehydrogenation, erosion, and hydrogenation all play a part.
Charge transport in random organic photoconductors
Authors: Bässler Heinz
Published: December 2004

Electrophotography, the technology of modern photocopiers, is the only area in which the photoelectronic properties of organic materials are exploited on a large‐scale industrial basis. Neither crystalline nor polycrystalline materials can meet the requirements set by current designs, and polymers are obvious candidates. However, these need to be improved by controlling (or eliminating) the charge‐carrier trapping and by understanding how their morphology and disorder affect charge transport. Recent work on the photoconductivity of organic solids is described, indicating that although progress has been made much remains to be done.
Allyl(β‐diketonato)palladium(II) complexes as precursors for palladium films
Authors: Yuan Zheng , Puddephatt Richard J.
Published: December 2004

Chemical vapor deposition (CVD) of palladium is at present not used commercially, despite the widespread use of palladium films in electronics and data storage, because suitable precursors are not available. New palladium precursors, ally (β‐diketonato)palladium(II) complexes (see Figure) are reported, along with the conditions required for the formation of pure palladium films by CVD.

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A further polymerization effect following the electrochemical synthesis of poly(2,5‐dimethoxyaniline)
Authors: Pistoia Gianfranco
Published: December 2004

A post‐polymerization effect for poly(2,5‐dimethoxyaniline), PDMA, has been observed in which PDMA inthe form of needles grows on the porous granular surface of the polymer previously formed by electrosynthesis (see Figure). Details of voltammetry experiments are given and an explanation for the post‐polymerization effect proposed.

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α‐Sexithiopene; A new photochromic material for a prototype ultrafast incoherent‐to‐coherent optical converter
Authors: Fichou Denis , Nunzi Jean‐Michel , Charra Farbrice , Pfeffer Nicola
Published: December 2004

Ultrafast incoherent‐to‐coherent optical converters based on α‐sexithiophen (α‐6T) thin films are described. Unlike state‐of‐the‐art materials for spatial light modulation such as liquied crystals and photorefractives, the spectral concentration and fast response times in α‐6T thin films originate at the molecular level, and thus can be modeled using simple molecular engineering rules.
Nanometer‐scale reversible recording using STM
Authors: Sato Akinobu , Tsukamoto Yuji
Published: December 2004

Data storae using the scanning tunneling microscope has come one step nearer. Instead of using changes in surface morphology for recording as previously proposed, changes in tunneling current are produced by locally induced phase transitions between crystalline and glassy forms of avanadate composite material. This has the advantages of being reversible, a room‐temperature technique, and less susceptible to defects. The recording mechanism is though to the pulse‐voltage‐induced migration of sodium ions along the electric field.
Arg—Gly—Asp peptides in polyurethanes: Design, synthesis, and characterization
Authors: Ho Siew Peng , Britton Dustin H. O.
Published: December 2004

Peptide‐containing polymers have been synthesized with the aim of using polymers as synthetic scaffolds for biologically active peptide sequences. Introducing the peptide shown in the figure during polyurethane synthesis resulted in a series of peptide‐polymer hybrids containing the Arg‐Gly‐Asp sequence, which plays a central role in cel adhesion.

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Oligothiophenes as models for polythiophenes. The crystal and molecular structures of 3″, 4″‐dibutylpentathiophene and 3′,3″ ″,4′, 4″ ″‐tetrabutylhexathiophene
Authors: Liao Ju‐Hsiou , Benz Michael , Legoff Eugene , Kanatzidis Mercouri G.
Published: December 2004

Knowledge of the crystal structures of oligothiophenes is necessary if progress is to be made towards understanding the structure‐property relationships of polythiophenes, since single crystals of these conducting polymers are not available. Two oligothiophene derivatives (one of which is shown in the Figure) have been designed, synthesized, and struturally characterized.

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