bluuebunny/crossref_metadata_2025_split huggingface dataset:
Kinetics of ethanol production by recombinant Escherichia coli KO11
Authors: Olsson L. , Hahn‐Hägerdal B. , Zacchi G. 
Published: December 2004

AbstractThe fermentation kinetics for separate as well as simultaneous glucose and xylose fermentation with recombinant ethanologenic Escherichia coli KO11 are presented. Glucose and xylose were consumed simultaneously and exhibited mutual inhibition. The glucose exhibited 15 times stronger inhibition in xyclose fermentation than vice versa. The fermentation of condensate from steampretreated willow (Salix) was investigated. The kinetics were studied in detoxified as well as in nondetoxified condensate. The fermentation of the condensate followed two phases: First the glucose and some of the pentoses (xylose in addition to small amounts of arabinose) were fermented simultaneously, and then the remaining part of the pentoses were fermented. The rate of the first phase was independent of the detoxification method used, whereas the rate of the second phase was found to be strongly dependent. When the condensate was detoxified with overliming in combination with sulfite, which was the best detoxification method investigated, the sugars in the condensate, 9 g/L, were fermented in 11 h. The same fermentation took 150 h in nondetoxified condensate. The experimental data were used to develop an empirical model, describing the batch fermentation of recombinant E. coli KO11 in the condensate. The model is based on Monod kinetics including substrate and product inhibition and the sum of the inhibition exerted by the rest of the inhibitors, lumped together. © 1995 John Wiley & Sons, Inc.
Structured modeling and state estimation in a fermentation process: Lipase production by Candida rugosa
Authors: Montesinos J. L. , Lafuente J. , Gordillo M. A. , Valero F. , Solà C. , Charbonnier S. , Cheruy A. 
Published: December 2004

AbstractA simple structured mathematical model coupled with a methodology of state and parameter estimation is developed for lipase production by Candida rugosa in batch fermentation. The model describes the system according to the following qualitative observations and hypothesis: Lipase production is induced by extracellular oleic acid present in the medium. The acid is transported into the cell where it is consumed, transformed, and stored. Lipase is excreted to the medium where it is distributed between the available oil‐water interphase and aqueous phase. Cell growth is modulated by the intracellular substrate concentration. Model parameters have been determined and the whole model validated against experiments not used in their determination. The estimation problem consists in the estimation of three state variables (biomass, intra‐ and extracellular substrate) and two kinetic parameters by using only the on‐line measurement provided by exhaust gas analysis. The presented estimation strategy divides the complex problem into three subproblems that can be solved by stable algorithms. The estimation of biomass (X) and the specific growth rate (μ), is achieved by a recursive prediction error algorithm using the on‐line measurement of the carbon dioxide evolution rate. μ is then used to perform an estimation of intracellular substrate and the other kinetic parameter related to substrate transport (A) by an adaptive observer. Extracellular substrate is then evaluated by means of the estimated values of intracellular substrate and biomass through the material balance of the reactor. Simulation and experimental tests showed good performance of the developed estimator, which appears suitable to be used for process control and monitoring. © 1995 John Wiley & Sons, Inc.
Fatty acid esterification using nylon‐immobilized lipase
Authors: Zaidi Ahmed , Gainer John L. , Carta Giorgio 
Published: December 2004

AbstractThe esterification of a long‐chain fatty acid was conducted using a nylon‐immobilized lipase from Candida cylindracea in a nearly anhydrous, nonpolar organic medium, hexane. Butyl laurate was produced from lauric acid and n‐butanol at a maximum initial reaction rate of 37 mmol/h. g immobilized enzyme when the substrates were present in equimolar amounts at an initial concentration of 0.5 mol/L. Lower rates were obtained using nonstoichiometric amounts of the substrates. The rate of reaction increased with temperature, reaching a maximum between 35 and 45°C and decreasing sharply at higher temperatures. © 1995 John Wiley & Sons, Inc.
Modeling simultaneous hexavalent chromium reduction and phenol degradation by a defined coculture of bacteria
Authors: Shen Hai , Wang Yi‐Tin 
Published: December 2004

AbstractBased on the kinetics of Cr(VI) reduction by Escherichia coli ATCC 33456 and phenol degradation by Pseudomonas putida DMP‐1, a mathematical model is developed to describe simultaneous Cr(VI) reduction and phenol degradation in the coculture of the two species. The developed model incorporates the toxicity effects of Cr(VI) and phenol on phenol degradation and Cr(VI) reduction in the coculture. The model illustrates the inhibitory effects of phenol on Cr(VI) reduction and Cr(VI) toxicity toward phenol degradation. The model also reveals the recoveries of the activities of the repressed bacterial cells with continuous Cr(VI) reduction and phenol degradation in the coculture. The model is capable of predicting simultaneous Cr(VI) reduction and phenol degradation within a broad range of Cr(VI) and phenol concentrations and under an appropriate composition of populations. However, the model simulates lower concentrations of phenol than experimental observations once Cr(VI) is reduced to a low level (<7 mg/L). The model simulation for Cr(VI) also deviates from experimental data when P. putida is outnumbered by E. coli by a ratio of 1:5. © 1995 John Wiley & Sons, Inc.
Thermodynamic approach to explain cell adhesion to air–medium interfaces
Authors: Chattopadhyay Devamita , Rathman James F. , Chalmers Jeffrey J. 
Published: December 2004

AbstractCell damage has been observed in suspension cell cultures with air sparging, especially in the absence of any protective additives. This damage is associated with cells adhering to bubbles, and it has been shown that if this adhesion is prevented, cell damage is prevented. This article presents a thermodynamic approach for predicting cell adhesion at the air–medium interface. With this relationship it can be shown that cell–gas adhesion can be prevented by lowering the surface tension of the liquid growth medium through the addition of surface–active protective additives. The thermodynamic relationship describes the change in free energy as a function of the interfacial tensions between the (i) gas and liquid phases, (ii) gas and cell phases, and (iii) liquid and cell phases. Experimental data, along with theoretical and empirical equations, are used to quantify the changes in free energy that predict the process of cell–gas adhesion. The thermodynamic model is nonspecific in nature and, consequently, results are equally valid for all types of cells. © 1995 John Wiley & Sons, Inc.
Kinetics of chlorinated ethylene dehalogenation under methanogenic conditions
Authors: Skeen Rodney S. , Gao Jianwei , Hooker Brian S. 
Published: December 2004

AbstractKinetics were determined for methanogenic activity and chlorinated ethylene dehalogenation by a methanol‐enriched, anaerobic sediment consortium. The culture reductively dechlorinated perchloroethylene (PCE) to trichloroethylene (TCE), 1,1‐dichloroethylene (1,1‐DCE), vinylchloride (VC), and ethylene and ethane. The absence : of methanol or the addition of 2‐bromoethanesulfonic. acid in the presence of methanol suppressed both methanogenic activity and dechlorination. In contrast, acetate production continued in the presence of 2‐bromoethanesulfonic acid. These results suggest that dechlorination was strongly linked to methane formation and not to acetate production. A kinetic model, developed to describe both methanogenesis and dechlorination, successfully predicted experimentally measured concentrations of biomass, methane, substrate, and chlorinated ethylenes. The average maximum specific dehalogenation rates for PCE, TCE, 1,1‐DCE, and VC were 0.9 ± 0.6, 0.4 ± 0.1, 12 ± 0.1, and 2.5 ± 1.7 μmol contaminant/ g. DW/day, respectively. This pattern for dechlorination rates is distinctly different than that reported for transition metal cofactors, where rates drop by approximately one order of magnitude as each successive chlorine is removed. The experimental results and kinetic analysis suggest that it will be impractical to targeting methanol consuming methanogenic organisms for in situ ground‐water restoration. © 1995 John Wiley & Sons, Inc.
Analysis of Noncovalent Complexes between Human Telomeric DNA and Polyamides Containing N‐Methylpyrrole and N‐Methylimidazole by Using Electrospray Ionization Mass Spectrometry
Authors: Zhou Jiang , Yuan Gu 
Published: December 2004

AbstractElectrospray ionization mass spectrometry (ESI‐MS) was used to investigate noncovalent complexes formed between four novel polyamides containing N‐methylpyrrole (Py) and N‐methylimidazole (Im), and human telomeric DNA. Of the four polyamides investigated, PyPyPyγImImImβDp (3) had the highest binding affinity towards the duplex d(TTAGGGTTAGGG/CCCTAACCCTAA) (D1). Results of competition analysis showed that the polyamides had binding affinities with D1 in the order PyPyPyγImImImβDp (3)>PyPyPyPyγPyImImPyβDp (4)>PyPyPyβImImImβDp (2)≫ImImImβDp (1). MS/MS spectra confirmed that binding between D1 and the hairpin polyamides is more stable than that with the three‐ring polyamides. By contrast, in the case of single‐stranded d(TTAGGGTTAGGG)(D2), the binding order changes to ImImImβDp (1)>PyPyPyγImImImβDp (3)>PyPyPyβImImImβDp (2).
Helical Arrays of Pendant Fullerenes on Optically Active Poly(phenylacetylene)s
Authors: Nishimura Tatsuya , Maeda Katsuhiro , Ohsawa Sousuke , Yashima Eiji 
Published: December 2004

AbstractNovel, optically active, stereoregular poly(phenylacetylene)s bearing the bulky fullerene as the pendant were synthesized by copolymerization of an achiral phenylacetylene bearing a [60]fullerene unit with optically active phenylacetylene components in the presence of a rhodium catalyst. The C60‐bound phenylacetylene was prepared by treatment of C60 with N‐(4‐ethynylbenzyl)glycine in a Prato reaction. The obtained copolymers exhibited induced circular dichroism (ICD) in solution both in the main‐chain region and in the achiral fullerene chromophoric region, although their ICD intensities were highly dependent on the structures of the optically active phenylacetylenes and the solution temperature. These results indicate that the optically active copolymers form one‐handed helical structures and that the pendant achiral fullerene groups are arranged in helical arrays with a predominant screw sense along the polymer backbone. The structures and morphology of the copolymers on solid substrates were also investigated by atomic force microscopy.
Insight into the Mechanism of Oxidative Kinetic Resolution of Racemic Secondary Alcohols by Using Manganese(III)(Salen) Complexes as Catalysts
Authors: Li Zhen , Tang Zhong H. , Hu Xiao X. , Xia Chun G. 
Published: December 2004

AbstractThe oxidative kinetic resolution of various racemic secondary alcohols with PhI(OAc)2 catalyzed by chiral [MnIII(salen)] complexes in the presence of KBr was studied in a water/organic solvent mixture. The dramatic, synergetic effect of additives, organic solvent, and the substituents of chiral salen ligands on the enantioselectivities of the reactions is reported. Results from UV/Vis spectroscopy and ESI‐MS studies provide evidence that these reactions are induced by the formation of a high‐valent manganese intermediate.
Erhöhung des Wirkungsgrades von Katalysatoren für Gasreaktionen
Authors: Reitlinger O. 
Published: December 2004

AbstractEs wird ein Verfahren beschrieben, die wirksame Oberfläche eines Katalysators ohne Behinderung des Gastransportes zu erhöhen durch Aufbringen des katalysierenden Stoffes in Pulverform auf impräginerte Körner ohne Beimischung eines Bindemittels und ohne mechanischen Druck. Die Katalysatoren sind schüttfest. Sechs Beispiele mit vergleichenden Versuchen an großtechnisch wichtigen Prozessen zeigen eine um ein Vielfaches erhöhte Ausbeute.
Betriebssicherheit neuzeitlicher Lösungsmittel‐Wiedergewinnungsanlagen
Authors: Knop W. 
Published: December 2004

AbstractIm Hinblick auf die zunehmende Bedeutung der Verfahren zur Wiedergewinnung von Lösungsmitteln sind die Fragen der Betriebssicherheit derartiger Anlagen von großem technischen Interesse. Es zeigt sich, daß das Adsorptionsverfahren mit Aktivkohle gegenüber dem Verfahren mit Silicarbon bezüglich der Sicherheit keine Nachteile hat, da die Entzündungstemperaturen beider Adsorbentien praktisch gleich hoch liegen. Beide Adsorbentien sind bei den üblichen Verfahrenstemperaturen praktisch nicht entzündbar. Bei Einhaltung der Bedienungsvorschriften ist eine gute Betriebssicherheit gewährleistet.
Temperaturverlauf und Wärmeverluste beim Anheizen und Abkühlen dickwandiger, kugelförmiger Behälter. Teil I: Anheizen flüssigkeitsgefüllter Behälter
Authors: Baehr H. D. 
Published: December 2004

AbstractDie Berechnung des Temperaturverlaufs und der Wärmeströme beim Anheizen oder Abkühlen dickwandiger Behälter stellt ein verwickeltes Problem der nichtstationären Wärmeleitung dar. Man kann nämlich in diesem Fall, etwa bei isolierten oder ausgemauerten Behältern, die Wärmespeicherung in den Behälterwänden nicht vernachlässigen. Im folgenden wird das Anheizen von flüssigkeitsgefüllten, kugelförmigen Behältern behandelt, bei denen die Wärme im Innern des Behälters zugeführt wird. Die Heizleistung ist variabel, wird jedoch als abschnittsweise konstant angesehen. Von der üblichen Lösung der Wärmeleitungs‐Differentialgleichung, die als eine unendliche Reihe erscheint, wird nur das erste Glied beibehalten. Da diese Vereinfachung für den Beginn des Anheizens zu Fehlern führt, werden mit Hilfe der Laplace‐Transformation andere Lösungen entwickelt, die bei Beginn des Anheizens brauchbar sind. Mehrere Diagramme erleichtern die Anwendung der Gleichungen, die an einem Beispiel gezeigt wird. Im zweiten Fall der Untersuchung wird der Abkühlungsvorgang behandelt und die bisher gewonnenen Ergebnisse werden auf gasgefüllte Behälter ausgedehnt.
CVD of CeO2‐Doped Y2O3‐Stabilized Zirconia onto Dense and Porous Substrates
Authors: Siadati Mohammad H. , Ward Timothy L. , Martus Jeffrey , Atanasova Paolina , Xia Changfeng , Schwartz Robert W. 
Published: December 2004

AbstractFabrication of dense films of mixed‐conducting oxides on porous surfaces is of interest for membrane, sensor, fuel cell, and battery applications. In this work, atmospheric‐pressure metal‐organic CHEMICAL VAPOR DEPOSITION was used to fabricate CeO2‐doped Y2O3‐stabilized ZrO2 films on dense silicon and porous alumina substrates. Aerosol‐assisted delivery of a toluene solution of the precursors Zr(tfac)4, Y(hfac)3, and Ce(tmhd)4 was used to deposit films with thicknesses around 1 μm. The effects of carrier gas O2 content (0–5 mol‐%), H2O vapor (0–3.4 mol‐%), deposition temperature (300–600°C), and the type of substrate on film morphology, composition, and purity were investigated. The porous substrate had a marked effect on the film morphology, producing a columnar film structure with column diameters that roughly approximated the particle diameter of the substrate (∼0.5 μm). Lower temperatures (300°C) provided a more uniform film with better connectivity between columnar structures than deposition at 400 and 600°C, and higher precursor concentrations produced very non‐uniform films with exaggerated growth features.
Characterization of Frzb‐Cre transgenic mouse
Authors: Tylzanowski Przemko , Bossuyt Wouter , Thomas J. Terrig , Luyten Frank P. 
Published: December 2004

AbstractThe Wnt family of glycoproteins is involved in numerous developmental and disease processes in higher eukaryotes, exerting their action by binding to cell‐surface receptors. In the extracellular space, Wnts are negatively regulated by secreted antagonists that either bind to the receptors directly (Dkk1) or to Wnt molecules themselves (Sfrp‐FRZB family), preventing its subsequent binding to the receptor. Here we report on a transgenic mouse expressing Cre under the control of the mouse Frzb promoter element. Analysis of the Cre expression was carried out at 10.5 and 14.5 dpc using the ROSA26R mouse line. Expression of the transgenic construct was detected in the limbs, the heart, the nasal epithelium, bone, whiskers, and around the orbita of the eye. The mouse could be used for conditional gene modification in those tissues. genesis 40:200–204, 2004. © 2004 Wiley‐Liss, Inc.
Workshop on characterization of calcium phosphate materials
Authors: Koeneman James , Lemons Jack , Ducheyne Paul , Lacefield William , Magee Frank , Calahan Thomas , Kay John 
Published: December 2004

AbstractCalcium phosphate materials are being extensively investigated for orthopaedic and dental applications. Bone grafts and bone substitutes are being developed using many forms of these materials. Numerous medical devices are being coated with them. Because of the many forms that calcium phosphate materials take, characterization of the material under investigation is essential. Aworkshop sponsored by the Society For Biomaterials on characterization of calcium phosphate materials was held on June 14 and 15, 1989. Sessions discussing the historical development, in vitro characterization, in vitro coating characterization, in vivo coating characterization, the FDA perspective, and the manufacturers perspective were held. A summary of the workshop with references is presented.
Pyrolytic carbon prosthetic heart valve occluder wear: In Vivo vs. In Vitro results for the Bjork‐Shiley prosthesis
Authors: More Robert B. , Silver Malcolm D. 
Published: December 2004

AbstractPyrolytic carbon (Pyrolite® carbon) valve occluders from 18 clinical Bjork‐Shiley prostheses recovered at necropsy were examined for wear. In situ durations extended to 12 years. Results were combined with data from 17 recovered valves in the literature to produce a data base of 35 Bjork‐Shiley valves. Cumulative in vivo results were compared to in vitro, Shiley type, accelerated life‐cycle tester results for Bjork‐Shiley prostheses. Comparative results were then interpreted using Hertzian impact wear theory. The theory provided a rational basis for the difference in wear observed in terms of applied dynamic load levels. Furthermore, Hertzian impact wear theory yielded an estimate of in vivo total dynamic loads on the order of 1 to 22 Newtons (0.2–5 lbf.) acting on the occluder of the heart valve prosthesis.
Anodic polarization measurements of orthopaedic implant alloys in bovine serum albumin
Authors: Nakayama Yuichiro , Yamamuro Takao , Kumar Praveen , Shimizu Kouichiro , Kotoura Yoshihiko , Oka Masanori , Kawafuku Junji , Takashima Takahiro 
Published: December 2004

AbstractAnodic polarization measurements of several orthopaedic implant alloys—AISI 316L stainless steel, CoCrMo alloy (ASTM F‐75), nickel‐titanium (NiTi) alloy, commercial pure titanium, and Ti6Al4V—were carried out in Ringer's solution containing 1% bovine serum albumin (BSA) and in simple Ringer's solution. Constituent metals in the medium were analyzed by inductively coupled plasma emission spectrophotometry after measurements. Pitting potentials and total anodic current of former two alloys were constant in the two mediums and not affected by the addition of bovine serum albumin. However, the amount of dissolved metals from pure nickel and AISI 316L stainless steel were increased by the addition of BSA; dissolved metals from CoCrMo alloy were decreased by it.
Applied biomaterials standards report
Authors: Daniels A. U. “Dan” 
Published: December 2004

AbstractThe purpose of my column is to provide readers with current information on biomaterialsrelated standards produced by both private groups and government agencies, and standards‐related activities. Standards are descriptive documents given official status by their producers, and in the case of biomaterials, they are generally intended to provide formalized descriptions of (a) materials used in the construction of medical devices, (b) materials used directly in surgical repairs, (c) test methods to evaluate materials for such applications, and (d) methods for handling or processing such materials.Please consider this column not only a place to obtain biomaterials standards information, but also a place to submit news of biomaterials standards developments in order to get the information before the public. This inviation extends to members of all professional organizations and government agencies in the United States and abroad who are active in standards development and would like specific activities or standards publicized. I will present the information in this column to the extent that allotted space allows.And last, a caveat‐since this is a column, it contains both factual information and opinions. I will make every effort to make it clear which is which. Also, as a frame of reference, please note that this column was written and submitted in September 1990.
Emailliertes Aluminium
Authors: Vielhaber Louis 
Published: December 2004

AbstractIn den USA und in England ist man dazu übergegangen, Aluminium zu emaillieren. Hierfür mußten neuartige Emails entwickelt werden, deren Wärmeausdehnung der des Aluminiums angepaßt ist und die bei 660°C eingebrannt werden können. Um diesen niedrigen Erweichungspunkt zu erreichen, wurden zuerst stark bleihaltige Emails entwickelt, später gelang es auch durch Verwendung eutektischer Mischungen bleifreie Emails herzustellen. Die englischen „Aluglas”︁ ‐Emails können ohne besondere Vorbehandlung des Al aufgeschmolzen werden. Im Übrigen wird eine vorherige Verkupferung oder Erzeugung einer Chrom‐Aluminium‐Oxydschicht empfohlen. Emailliertes Aluminium soll nicht das emaillierte Eisen ersetzen, sondern bisherige Veredelungsverfahren für Aluminium. Für Eß‐,Koch‐ und Trinkgefäße ist emailliertes Aluminium nicht geeignet. Vorgeschlagen für das Emaillieren werden Platten zur Wandbekleidung, Fensterrahmen, Schilder, Schutzverkleidungen usw. Die Anforderungen an diese Emaillierungen sind mannigfaltig und die Prüfung der Emaillierung muß sich daher auch auf die verschiedensten Eigenschaften erstrecken. Infolge des geringen Kieselsäuregehaltes der Al‐Emails ist nicht mit einer großen Säurebeständigkeit zu rechnen. Emaillierungen von Aluminium sind aber auf alle Fälle dauerhafter als z. B. Anstriche aus Alkyd‐Amin.
Theorie und Praxis des Flammstrahlens
Authors: Sippell Karl W. 
Published: December 2004

AbstractBei der Anwendung des Flammstrahlens ist die Einhaltung bestimmter Verfahrensregeln besonders zu beachten. Es wird daher ein Überblick gegeben über den Einfluß der Flammentemperatur auf die Eigenschaften von Baustählen und über den Einfluß verschiedener Brenngase auf die Wirksamkeit des Verfahrens. Weiterhin stimmen die Ergebnisse einer Anzahl von Untersuchungen zur Ermittlung der günstigsten Flammstrahlbedingungen mit den in der Praxis gefundenen Werten in fast allen Fällen überein. Infolgedessen ist es nun möglich, endgültige Verfahrensregeln mitzuteilen.Eine ausführliche Beschreibung der praktischen Durchführung des Verfahrens soll jeden Zweifel an der richtigen Handhabung der Geräte und der zweckmäßigen Einrichtung der Arbeitsstelle ausschließen.Die Einwirkungen verschiedener bisher üblicher Säuberungsmethoden und des Flammstrahlens auf die Beschaffenheit der behandelten Stahloberflächen lassen neben anderen Vorzügen die Überlegenheit des Verfahrens erkennen. Die Wirksamkeit und Wirtschaftlichkeit des Flammstrahlens wird durch eine Anzahl Beispiele dargestellt, wobei die neuesten Erkenntnisse über das Beseitigen der Walzhaut an Blechen ihrer Bedeutung entsprechend einen breiten Raum einnehmen.Abschließend ist auf eine noch in der Entwicklung befindliche Methode der zusätzlichen Passivierung von gesäuberten Stahloberflächen hingewiesen.