bluuebunny/crossref_metadata_2025_split huggingface dataset:
Biodegradability of lignosulphonate by Streptomyces viridosporus strain T7A and a mixed natural microbial population antagonistic effects
Authors: Hernandez‐pérez G. , Goma G. , Rols J. L. 
Published: December 2004

AbstractThe ability of a mixed natural microbial population, collected in an aerated lagoon treating Fluff pulp effluent and Streptomyces viridosporus strain T7A, to degrade lignosulphonate was evaluated. S. viridosporus growing in a mineral medium containing glycerol (7 g/l) and lignosulphonate (1 g/l) allowed 20% of lignosulphonate to be degraded after 18 days of incubation. A culture of the mixed population on culture medium after S. viridosporus growth was unable to degrade lignosulphonate products. Moreover, antagonism between S. viridosporus and the mixed population or between S. viridosporus and the isolated strains from this population was observed. The enhancement of lignosulphonate biodegradation by naturally occurring microorganisms in association with S. viridosporus (bioaugmentation strategy) seems to be difficult.
Culture conditions for the production of pectinolytic enzymes by the white‐rot fungus Trametes trogii on a laboratory scale
Authors: Levin L. , Forchiassin F. 
Published: December 2004

AbstractDifferent cultural parameters that regulate pectinolytic enzyme production in vitro by Trametes trogii were studied. When grown in a medium containing pectin, T. trogii produced extracellular polymethylgalacturonase, polygalacturonase and pectin lyase but no pectate lyase activity. No significant differences in the maximum enzyme activities measured were observed with the addition of xylan, carboxymethylcellulose or both to the medium containing pectin. The addition of glucose to that medium considerably decreases all the activities studied, and in a medium with glucose as the sole carbon source no galacturonase activity could be measured, and pectin lyase activity was at its minimum. The low synthesis of pectin lyase in cultures containing glucose suggests that this enzyme is constitutive in contrast to the polygalacturonases that were not detected. The increase in pectin concentration stimulated growth and enzyme production. The highest specific activities were attained with the greatest concentration tested (15 g/l). Casamino acids were the best nitrogen source for enzyme production. Maximum growth was measured at pH 3.3; pH values of around 4.5 stimulated enzyme production, but high pectinase activities were also detected in media with more alkaline initial pH values (6.2 for galacturonases and 6.6 for lyases), probably owing to the specific induction of particular isoforms. In the range of 23 to 28°C, good results were obtained in growth as well as in enzyme production. The addition of Tween 80 promoted growth and gave the highest yield of polymethylgalacturonase and pectin lyase (0.37 and 36.2 E.U./ml, respectively). The highest polygalacturonase activity (1.1 E.U/ml) was achieved with polyethylene glycol. Tween 20 and Triton X‐100 inhibited growth and pectinase production.
Influence of different vitamin‐nitrogen sources on cell growth and propionic acid production from sucrose by Propionibacterium shermanii
Authors: Quesada‐Chanto A. , Da Costa J. P. C. L. , Silveira M. M. , Schroeder A. G. , Schroeder A. G. , Schmid‐Meyer A. C. , Jonas R. 
Published: December 2004

AbstractCell growth and organic acid production by Propionibacteria are dependent on the vitamin‐nitrogen source in the culture medium. Final cell and propionic acid concentrations produced by Propionibacterium shermanii, using corn‐steep liquor, were higher than those obtained utilizing yeast extracts. Since corn‐steep liquor is much cheaper than yeast extract, the process becomes more attractive. By calculating the specific growth rates, it was observed that the critical propionic acid concentration, that prevents all growth (μX = 0), is different depending on the vitamin‐nitrogen source used and its concentration. For example, for 5.0 and 15.0 g/l Oxoid yeast extract, those critical propionic acid concentrations were 16.0 and 27.0 g/l, respectively. Such propionic acid concentrations inhibit the cell growth, but not the formation of acid. The specific propionic acid production rate also indicates that the critical concentration for metabolic activity, when propionic acid is no longer produced (μP = 0), varies according to the vitamin‐nitrogen source and its concentration in the medium. For 5.0 and 15.0 g/l Oxoid yeast extract, those concentrations were 22.1 and 30.1 g/l, respectively.
Stability of a polyphenol oxidase from the white‐rot fungus Trametes versicolor in the presence of canola meal
Authors: Lacki K. , Duvnjak Z. 
Published: December 2004

AbstractThe stability of a polyphenol oxidase (PPO) preparation from the white‐rot fungus Trametes versicolor during a process for the enzymatic decrease of the phenolic content of commercial canola meal (CM) was investigated. The effects of temperature, pH, protein origin and concentration, and meal particles were considered. The results showed that the thermal stability of the enzyme preparation was significantly increased in the presence of CM. The half‐life times for the enzyme preparation, pre‐incubated with CM at 50, 60, 70 and 75°C, were 45, 10.5, 3.5 and 1.5 hours, respectively; this represents an increase in the thermal stability of the enzyme preparation of up to four times in the presence of CM compared to the stability in the absence of CM. This effect was caused by the protective actions of both the CM particles and CM proteins, with the former responsible for 90% of the observed effect. The thermal stability of the enzyme in the presence of CM, from which 20% of the extractable proteins was extracted, was 5% lower compared to the stability in the presence of untreated CM. Changes in pH level from 5.0 to 3.2 resulted in a loss of stability comparable to that observed when the pre‐incubation temperature was increased from 50 to 70°C.A semi‐empirical model describing the changes in the concentration of the active enzyme pre‐incubated in the presence and absence of CM at various incubation temperatures was proposed. A very good agreement between the model and experimental data was obtained. The proposed model, together with a general set of model parameters, can be used as a tool for the optimization of a process for the upgrade of CM by enzymatically decreasing the meal's phenolic content.
Mineral content of the fruiting bodies of Pleurotus sajor‐caju (FR.) SINGER cultivated on different kinds of biomass
Authors: Patrabansh S. , Madan M. 
Published: December 2004

AbstractPleurotus sajor‐caju (FR.) SINGER was cultivated on different organic wastes, namely sericulture waste, Populus deltoides MARSH, and Eupatorium adenophorum SPRENG. Paddy straw was taken as the control and all the data were compared with it. The mineral contents of the fruiting bodies of Pleurotus sajor‐caju and the substrates on which the mushroom was grown were analyzed. Among the eight minerals determined (calcium, phosphorus, potassium, magnesium, sodium, iron, manganese and zinc), the potassium content was highest followed by phosphorus, magnesium and sodium. Analysis of the mineral contents of the substrates before cultivation had also been carried out. The mineral contents of the fruiting bodies of Pleurotus sajor‐caju were found to be different on different substrates. It was also observed that the mineral contents of the fruiting bodies of Pleurotus sajor‐caju increase when cultivated on substrates with higher mineral contents. The maximum mineral contents per 100 g of the substrates before cultivation were Ca – 347 mg; P – 151 mg; K – 1,805 mg; Na – 127 mg; Mg – 227 mg; Fe – 53 mg; Mn – 10 mg and zn – 3.1 mg. The mineral contents of the fruiting bodies of Pleurotus sajor‐caju per 100 g ranged as follows: Ca – 25.1 mg to 35.3 mg; P – 448 mg to 602 mg; K – 2,146 mg to 2350 mg; Na – 139 mg to 229 mg; Mg – 153 mg to 224 mg; Fe – 9.74 mg to 20.75 mg; Mn – 2.5 mg to 4.0 mg and Zn – 2.2 mg to 3.1 mg.
Use of various coffee industry residues for the cultivation ofPleurotus ostreatusin solid state fermentation
Authors: Fan L. , Pandey A. , Mohan R. , Soccol C. R. 
Published: December 2004

AbstractStudies were carried out to evaluate the feasibility of using coffee industry residues,viz.coffee husk, coffee leaves and spent coffee ground as substrates in solid state fermentation (SSF) to cultivate edible mushroomsPleurotus. Eight strains ofPleurotus ostreatusand two strains ofPleurotus sajor‐cajuwere screened on a medium prepared from aqueous extract of coffee husk and agar. Based on best mycelial growth (9.68 mm/day) and biomass production (43.4 mg/plate in 9 days at 24°C), the strainP. ostreatusLPB 09 was selected for detailed studies. SSF was carried out using these substrates under different moisture conditions (45–75%) and spawn rates (2.5–25%). In general, although a 25% spawn rate appeared superior, the 10% spawn rate was recommended for all the three substrates in view of the process economics, as there was not any significant difference in the increase with 10 to 15%. The ideal moisture content for mycelial growth was 60–65% for coffee husk and spent coffee ground, and 60–70% for coffee leaves. The biological efficiency (BE), which is defined as the ratio of the weight of fresh fruiting bodies to the weight of dry substrate, multiplied by 100, and which indicates the fructification ability of the fungus for utilizing the substrate, was best with coffee husk. With coffee husk as the substrate, the first fructification occurred after 20 days of inoculation, and the biological efficiency reached about 97% after 60 days. When coffee leaves were used as the substrate, no fructification was observed even upon prolonged cultivation. With spent ground as the substrate, the first fructification occurred 23 days after inoculation and the biological efficiency reached about 90% in 50 days. There was a significant decrease in the caffeine and tannin contents (61 and 79%, respectively) of coffee husk after 60 days. It was remarkable to observe that caffeine was adsorbed onto the fruiting body (0.157%), indicating that it was not completely degraded by the fungal culture. However, no tannins were found in the fruiting body, indicating that the fungal strain was capable of degrading them. The results showed the feasibility of using coffee husk and spent coffee ground as substrates without any pre‐treatment for the cultivation of edible fungi in SSF, and provided one of the first steps towards an economical utilization of these otherwise unutilized or poorly utilized residues.
Wastewater treatment by the HCR‐process
Authors: Vogelpohl A. 
Published: December 2004

AbstractThe increasing requirements in wastewater treatment have led to the development of new wastewater treatment processes based on the know‐how and experience in reaction and process engineering of the chemical industry. Due to their compactness, closed operation and high flexibility, these new processes show a large potential for process integration and significant cost reduction in particular for highly polluted industrial wastewaters.This paper discusses the HCR (high‐performance compact reactor) ‐ process, developed at the Mass Transfer Laboratory of the Technical University of Clausthal within the last decade. This process has been realized in more than 30 technical applications with a volume loading of up to 70 kg COD/m3 d and an energy consumption of about 0.4 kWh per kg CODelim.
Electrochromic Materials for optical switching devices
Authors: Bange Klaus , Gambke Thomas 
Published: December 2004

AbstractThe basic principles of electrochromism have been reported and discussed using the example of WO3, and some other important electrochromic materials have been described which have a number of interesting technical applications. Both compounds and materials used in ECDs were discussed and the principles of device design were portrayed, using as an example a reflective ASSD. By continuing the search for new electrochromic compounds and by further improving device design and cost optimization the applications of these materials are bound to increase.
Diamond thin film technology I. Diamond deposition
Authors: Bachmann Peter K. 
Published: December 2004

Diamond thin film technology I. In the first article of a regular series Peter Bachmann of the Philips Research Labs in Aachen, FRG, describes the different methods used to deposit diamond in films (see figure). Diamond in this form has many applications e.g. as an abrasive material, in lithography masks, microwave windows, in heat sinks, and in LEDs to name just a few.magnified image
Crystal synthesis under langmuir monolayers
Authors: Mann Stephen , Heywood Brigid R. , Rajam Sundara , Walker Justin B. A. , Davey Roger J. , Birchall J. Derek 
Published: December 2004

Organized organic surfaces can have a pronounced influence on the controlled crystallization of calcium carbonate. The effect is based on an inorganic‐organic molecular recognition process which is important, for example, in biomineralization. The contributions of headgroup charge and ionic concentration are examined. One of the two types of vaterite (the less common polymorph of calcium carbonate) crystals grown are shown in the figure.magnified image
The potential of The Graphite Lattice
Authors: Hüttinger Klaus J. 
Published: December 2004

Carbon‐based materials including carbon fibers and composites are the subject of this review. Structural aspects are examined, for example the microstructure of a spun carbon fiber shown in the figure, and the strength and other properties of the materials analyzed with respect to various applicatiosn e.g. as biomaterials and in reinforcement technology.
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Direct imaging of Pd561(phen)38±2On and Au55(PPh3)12Cl6 clusters using scanning tunneling microscopy
Authors: Wierenga Harald A. , Soethout Luc , Gerritsen Jan W. , van de Leemput Bart E. C. , van Kempen Herman , Schmid Günther 
Published: December 2004

The first images of isolated full‐shell ligand‐stabilized clusters have been obtained using STM (see figure). The clusters are ideal model systems for studying the relationship between cluster size and electronic properties as well as having applications in catalysts and filters.magnified image
Ultrathin organic films: Molecular Architectures for advanced optical, electronic and bio‐related systems
Authors: Fuchs Harald , Ohst Holger , Prass Werner 
Published: December 2004

AbstractUltrathin ordered organic films with a thickness of a few nanometers to about a tenth of a micrometer show considerable technological potential as a novel class of materials. Of particular interest are their tailor‐made electrical and optical properties which are related to their anisotropic molecular structure which itself can be controlled on a molecular scale. A. critical review is given of the different aspects of the potential technological applications of ultrathin organic films. Some underlying chemical concepts and the basic problems to be solved in synthesis and preparation prior to application are discussed.
Carbohydrate‐modified conducting polymers synthesis and electrochemistry of sugar‐linked azulenes polyazulenes
Authors: Bross Peter Alexander. , Schöberl Ulrich , Daub Jörg 
Published: December 2004

Communication: Chiral‐polymer electrodes and electochemical sensor devices are two pro potential applications for carbohydrate‐modified conducting polymers with a polyazulene backbone (see figure where R is a sugar). Carbohydrate modification, whitel providing the conducting polymer with molecular‐targeting capability also lends water‐solubility to the intrinsicly hydrophobic azulene group and should therefore enable chemistry and electropolymerization in aqueous solution.magnified image
Defect chemistry of the high‐Tc superconductors
Authors: Maier Joachim , Pfundtner Gösta 
Published: December 2004

AbstractIn the high temperature superconductors the critical temperature is intimately connected to the electronic charge‐carrier concentration. The absolute values of this quantity and its dependencies on the controlling parameters temperature, oxygen partial pressure and doping content, is phenomenologically determined by the thermodynamics and kinetics of reactions involving point defects. Due to the low mobility of the ionic constituents the behavior at elevated temperatures is particularly important. Here, the kinetics are controlled by the mass transport parameters, essentially by the ionic conductivity.The scientific discipline whose objective is precisely described in the above terms is called defect chemistry. It quantitatively deals with the nature of excess and lacking native ionic or electronic particles as well as with foreign species. It describes the thermodynamics and kinetics of their formation, annihilation, interaction and motion in the phase under consideration and thus determines the chemistry within this phase.
High molecular weight poly([ 1.1.1]propellane)s and a new polyamide with bicyclo[1.1.1]pentane fragments
Authors: Bothe Harald , Schlüter Arnulf‐Dieter 
Published: December 2004

Communication: A polyamide, where the amide functions are connected via rigid, non‐aromatic units, which forms liquid‐crystalline phases in concentrated sulfuric acid and is thus suitable for the preparation of fibers is reported. The synthesis has been made possible by a breakthrough in the ability to produce high molecular weight poly([1.1.1]‐propellane)s (see Figure).magnified image
Structural characterization and properties of a new tetrathiafulvalene‐based cage molecule derived from an azacrown
Authors: Jørgensen Tine , Becher Jan , Hansen Thomas Kruse , Christiansen Kim , Roepstorff Peter , Larsen Sine , Nygaard Anne 
Published: December 2004

Communication: A cage molecule combining a precursor of the electroactive tetrathiafulvalene (TTF) unit with a macrocycle capable of complexing transition metals (see Figure) is reported. The preparation of this compound and the TTF‐based compound whose cavity is too small for complexing the metal are reported.magnified image
Organometallic molecular precursors for low‐temperature MOCVD of III–V semiconductors
Authors: Maury Francis 
Published: December 2004

AbstractMetal‐organic chemical vapor deposition (MOCVD) is a suitable technique for the preparation of III–V epitaxial layers which are used in the fabrication of microelectronic and optoelectronic devices. The usual Ga and As sources for GaAs are Ga(CH3)3 and AsH3, respectively. However, the use of these precursors has some disadvantages including: The toxicity and storage of arsine, stoichiometry control, carbon incorporation and unwanted side reactions. Several groups of researchers have investigated alternative sources for both the group–III and group‐V elements. A review of these new organometallic precursors is presented in this paper. However, because group‐III and group‐V elements form Lewis‐acid/base adducts in the MOCVD reactor, we have especially investigated the use of this class of compounds as single starting molecules. Several adducts have been successfully used for the epitaxial growth of GaAs. Moreover, to avoid any stoichiometry loss due to dissociation of the adduct, the properties of organometallic molecules which feature a covalent bond between the group‐III and group‐V elements have also been investigated. These covalent compounds are probably formed in the MOCVD reactor when alkyl group‐V compounds containing acidic hydrogen R3−nMHn (M = As, P; n = 1,2) are used. Such new precursors are also briefly reviewed.
Amorphous molecular materials: Synthesis and properties of a novel starburst molecule, 4,4′,4″ ‐Tri(N‐phenothiazinyl)triphenylamine
Authors: Higuchi Akiji , Inada Hiroshi , Kobata Tomokazu , Shirota Yasuhiko 
Published: December 2004

Communication: Processability, flexibility, transparency, and a lack of grain boundaries are some of the attractive properties of amorphous molecular materials. For their integration into electronics, however, it is important that the materials can form stable amorphous, glassy states with a glass‐transition temperature and, if any, a crystallization temperature as high as possible. The starburst molecule shown in the figure has a glass‐transition temperature of 141°C.magnified image
An hexagonal columnar mesophase in half‐disk‐shaped thallium (i) complexes
Authors: Barberá Joaquín , Cativiela Carlos , Serrano José Luis. , Zurbano María Mar 
Published: December 2004

Communication: The first example of a discotic thallium (I) metallomesogen is reported. The complex is formed by the association of two half‐disc‐shaped molecules (see figure) and the properties of the liquid crystalline material studied using DSC and X‐ray differaction. The materials, with varying numbers of alkyl groups bonded to the central aromatic cores, are also compared with the previously known copper analogues.
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Sevenfold diamond structure and conductivity of copper dicyanoquinonediimines Cu(DCNQI)2
Authors: Ermer Otto 
Published: December 2004

Communication: The high substituent sensitivity of the electrical conductivity of copper DCNQI radical anion salts (see figure) is atributed to the fact that the stacks of copper atoms and bridging DCNQI ligands are covalently clamped together within the frame work of a sevenfold interpenetrating super diamond architecture. This observation should influence more quantitative approaches to explaining and modeling the conductivity behaviour of the Cu(DCNQI)2 salts.magnified image
Highly‐ordered ultrathin lc multilayer films on solid substrates
Authors: Decher Gero , Maclennan Joseph , Reibel Jürgen , Sohling Ulrich 
Published: December 2004

Research News: Freely suspended thin film of smectic liquid crystalline materials can be described as two‐dimensinal fluids with a regular layer structure in the third dimention. By reducing the internal pressure in the set up shown in the figure the films can be transferred onto solid supports allowing their study, manipulation, and potential use in applications such as integrated optics and sensors.magnified image
Large changes in optical response through chemical pre‐ordering of poly(p‐phenylenevinylene)
Authors: Halliday David A. , Burn Paul L. , Bradley Donal D. C. , Friend Richard H. , Gelsen Olaf M. , Holmes Andrew B. , Kraft Arno , Martens Josef H. F. , Pichler Karl 
Published: December 2004

Conjugated polymers such as poly(p‐phenylenevinylene), (PPV, see Figure), show real promise in optoelectronic applications. A new synthetic route to improved PPV is presented, involving the thermal conversion of a precursor polymer containing rigid rod conjugated segments joined by flexible spacer groups. A high degree of interchain ordering results which influences the optical response of the material. magnified image
Compositional separation in CoCr based alloy films
Authors: Maeda Yasushi 
Published: December 2004

CoCr Based alloy thin films are being studied extensively for applications as high‐density magnetic recording media. The observation of a compositional microstructure the “chrysanthemum‐like pattern” (CP) in the Figure, is the first step towards understanding the mechanisms that make such applications possible. Much work remains to be done on the origin of the compositional separation causing the CP and on methods of controlling the CP. magnified image
Poly[(silylene)diacetylene]–metal oxide composites: A new approach to SiC–metal nitride ceramics
Authors: Corriu Robert , Gerbier Philippe , Guérin Christian , Henner Bernard 
Published: December 2004

Precursors to high‐performance ceramics, based on poly(silylene)diacetylene‐metal oxide composites see figure, are reported. On thermal conversion under nitrogen, carboreduction and nitridation of the encapsulated metal oxide take place, resulting in the formation of SiC‐metal nitride ceramics with well‐defined composition profiles. magnified image