bluuebunny/crossref_metadata_2025_split huggingface dataset:
Prozeßtechnische Aspekte der Produktion mit myzelbildenden Mikroorganismen
Authors: Schügerl Karl , Seidel Guido 
Published: December 2004

AbstractProcess Engineering Aspects of Production with Mycelium‐Forming Microorqanisms This review deals with process engineering aspects of biosynthesis, morphology and rheology of myceliumforming microorganisms, which produce secondary metabolites and proteins in semisynthetic and complex cultivation media. The interrelation of biosynthesis, morphology and rheology are discussed. Mathematical models for the biosynthesis and the morphological structures are presented. The investigations indicate that the results obtained with microorganisms cultivated in semisynthetic media cannot be directly transferred to systems with the same micro‐organisms cultivated in complex media.
GVC‐Fachausschuß „Kristallisation”︁
Authors: Gahn C. , Rauls M. 
Published: December 2004

AbstractDas diesjährige Treffen des GVC‐Fachausschusses „Kristallisation”︁ fand auf Einladung der SCHERING AG vom 22. bis 24. März in Berlin statt. Die Sitzung wurde vom scheidenden Vorsitzenden des Fachausschusses Prof. WINTERMANTEL, BASF AG, geleitet. Der Vorsitz des Fachausschusses geht in den kommenden Jahren auf Prof. KIND, Universität Karlsruhe, über. Prof. MERSMANN, TU München, scheidet als berufenes Mitglied aus dem Fachausschuß aus. Seine wissenschaftlichen Leistungen sowie sein Engagement als Mitglied und Vorsitzender des Fachausschusses wurden von Prof. Wintermantel gewürdigt.
GVC‐Fachausschuß „Aus‐ und Fortbildung in der Verfahrenstechnik”︁
Authors: Molzahn Martin 
Published: December 2004

AbstractAm 1. Dezember 1998 fand in Ludwigshafen eine interne Arbeitssitzung des GVC‐Fachausschusses „Aus und Fortbildung in der Verfahrenstechnik”︁ statt. Auf der Basis von insgesamt zehn Vorträgen diskutierten 32 Teilnehmer aus Hochschule und Industrie u. a. über die Einführung gestufter Studiengänge mit Bachelor‐Masterabschluß, über neuere Trends in der Ingenieurausbildung in Großbritannien, über Qualitätssicherung und Qualitätskontrolle an in‐ und ausländischen Hochschulen, über neue Studiengänge an Universitäten und Fachhochschulen sowie über Konsequenzen der Globalisierung des Bildungsmarktes.
Möglichkeiten zur Vorausberechnung von Verweilzeitverteilungen
Authors: Platzer Bernd , Steffani Katharina , GroßE Stefan 
Published: December 2004

AbstractPossible Approaches to the Prediction of Residence Time Distributions Although the experimental determination of residence time distributions is based on a black‐box method, the signal shape also permits certain conclusions to be drawn about the internal conditions. However, if it is to provide a sole basis for elucidating process steps in a plant this method is soon overtaxed. A deeper theoretical penetration of the pertinent transport processes opens up the way ahead. However, since residence time distributions are based on mass‐oriented considerations, substantial advances in fluid mechanics, where location‐based considerations predominate, have not led to improved predictive capability. Yet the computer power now available offers a variety of ways of calculating residence‐time distributions for a known flow profile, thus permitting a step in the direction of better predictability of residence time distributions. This article presents utilisable methods and evaluates them with regard to their demands on time and effort and their predictive power. Problems arising in connection with the models are discussed.
Elektrothermische Regeneration von Adsorbern – Ein Überblick über den Stand von Forschung und Entwicklung
Authors: Bathen Dieter , Schmidt‐Traub Henner 
Published: December 2004

AbstractElectrothermal Regeneration of Adsorbers ‐ Survey of Research and Development This article surveys the current state of the art in research and development in the area of electrothermal processes for the regeneration of spent adsorbers. In addition to processes based on the induction of electrical current in adsorber beds the paper considers processes in which the required desorption energy is supplied to the system by microwaves.
Elektrische Doppelschichten: Elektrostatik und Elektrodynamik
Authors: Lyklema Johannes 
Published: December 2004

AbstractElectrical Double Layers: Electrostatics and Electrodynamics Dispersions of solid particles in aqueous solutions almost invariably bear a surface charge which is compensated by an opposite charge in the solution. An electrical double layer is formed. The surface charge can sometimes be determined by titration. In practice, the electrokinetic potential or zeta potential is usually measured. This potential is a characteristic quantity for stability, rheology, sedimentation, etc., of disperse systems. This paper addresses the question of the relation of the electrokinetic potential to the static double layer parameters. To this end the author provides a detailed account of electrokinetic shear processes. In addition, new results obtained with the aid of molecular dynamics are also presented.
The use of analytical peak profile functions to fit diffraction data of planar faulted layer crystals
Authors: Estevez‐Rams E. , Penton A. , Martinez‐Garcia J. , Fuess H. 
Published: December 2004

AbstractThe implication of the use of particular peak profile functions in the fit of diffraction data on the nature and density of stacking faults in layered solids is studied. Common type of profile functions are studied: Gauss, Lorentz, pseudoVoigt and Pearson VII. An additional peak profile is introduced. For each profile function the decaying term of the probability correlation function is determined and the expression for the correlation length is deduced. The form of the asymmetric component of each profile is also reported. Experimental data is fitted using each profile and the results are discussed. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Untersuchungen zu Steifigkeitskennwerten von Mauerwerkwänden im Zustand I
Authors: Steinbach Frank , Pfeifer Matthias 
Published: December 2004

AbstractMauerwerk hat in den letzten Jahrzehnten einen rasanten Wandel hin zu einem hochspezialisierten Baustoff vollzogen. Für einige Disziplinen – z.B. den Wärmeschutz – kann man von einem “Hightech”‐Produkt sprechen. Auch die Modelle für die Bemessung von Mauerwerk werden differenzierter. Besonders im Hinblick auf die Vielfalt der angebotenen Steinsorten und Formate wurde in den letzten Jahren versucht, die Bemessung der individuellen Mauerwerkssorte anzupassen. In den Arbeiten [3] und [10] wurde verstärkt die Steingeometrie in die Bemessungsmodelle für Schubversagen bzw. Stabilitätsversagen einbezogen. Andere Arbeiten, darunter [11], haben das Stabilitätsversagen einachsig gespannter Wände unter Berücksichtigung der unterschiedlichen Spannungs‐ Dehnungsbeziehungen verschiedener Stein‐Mörtelkombinationen beleuchtet.Die Plattentragwirkung einer Mauerwerkwand wird wesentlich durch ihre Steifigkeiten in zueinander orthogonalen Richtungen beeinflußt. Die Unterschiede in der Fugenausbildung sowie in Steinform, ‐art und ‐format führen zu unterschiedlichen Steifigkeitsverteilungen, die bisher nur unzureichend bei der Schnittkraftermittlung und Nachweisführung berücksichtigt werden.Im Rahmen von ersten Tastversuchen wurden für ausgewählte Steine die Elastizitätsmoduln und die Querdehnzahlen in den beiden wesentlichen zueinander orthogonalen Wandrichtungen bestimmt. Die Stoßfuge wird i. allg. als statisch nicht mitwirkend angesetzt, weil sie entweder nicht ausreichend oder gar nicht vermörtelt ist. Dies führt zu einer Anisothropie, die sich sowohl bei der Scheibenbeanspruchung als auch bei der Plattenbiegung im Zustand I mit den ermittelten Kennwerten auf einfache Art berücksichtigen läßt.
High temperature oxygen index studies of halogenated polyester thermosets containing antimony and molybdenum oxides
Authors: Das M. , Haines P. J. , Lever T. J. , Skinner G. A. 
Published: December 2004

AbstractA study has been made of the effect of antimony and molybdenum oxides on the temperature‐critical oxygen index relationship of halogenated polyester thermosets. The polyesters were prepared from maleic anhydride, phthalic anhydride and propylene glycol, using either tetrachlorophthalic anhydride, tetrabromophthalic anhydride or chlorendic anhydride as the halogen source. Marked differences were observed in the effect of the two oxides. The critical oxygen index values of the halogenated polyesters containing maoybdenum (VI)oxide decreased with increase in timperature, which is in accordance with what is normally found for organic polymers, with and without additives. In contrast to this, the critical oxygen index values of the formulations containing antimony(II)oxide increased with increased with increase in temperature to reach a maximum value at around 100–150 °C. These results indicate that antimony(II)oxide is a better flame retardant than molybdenum(VI)oxide, since not only is it superior at the primary ignition stage but it shows enhanced activity at the higher temperatures which would be experienced by polymeric material in the early stages of a fire. It is concluded that higher temperature critical oxygen index studies provide a better guide to the flame retardant activity of additives than do ambient critical oxygen index determinations alone.
Some stochastic properties of fire plumes
Authors: Cox G. , Chitty R. 
Published: December 2004

AbstractReaction to fire tests are the main criteria used by legislators of fire regulations to determine the suitability of different materials for use in building construction. These do not always give reliable results, particularly when applied to new man‐made materials. Part of the explanation for this is the lack of detailed understanding of the heat and mass transfer processes occurring in fire. This is in part due to a lack of measurements of the fluctuating property field in the source plume. In this paper measurements of the probability density functions, spectra and mean square fluctuations of temperature together with the probability of combustion are reported for a stimulated fire plume. The results are consistent with the model of a fire comprising a series of narrow flame fronts oscillating at the flame flicker frequency (which for this system is 3 Hz). The effects of thermal inertia in thermocouples on the determination of mean and fluctuating gas temperature have been examined using the treatment of Ballantyne, Boon and Moss. The high‐frequency limitations of thermocouple and electrostatic probes have been discussed in the context of trubulent filed measurements in fires.
The formation of NOx from nitrogen containing materials in diffusion flames
Authors: Crowhurst D. , Simmons R. F. 
Published: December 2004

AbstractThe conversion of fuel‐N species to NOx in diffusion flames has been studied by adding acetonitrile to the fuel flow for a methane–Oxygen–argon diffusion flame burning in excess oxygen. It is shown that the conversion is significantly lower than that obtained in a ‘corresponding’ pre‐mixed flame, although the observed concentrations of NOx are still much higher than the appropriate thermodynamic equilibrium concentrations. The effect of initial concentration of acetonitrile, flame temperature and amount of excess oxygen on the conversion can all be explained in terms of the basic structure of a diffusion flame. This enables molecular nitrogen to be formed in the reducing atmosphere which exists on the fuel side of the flame through reaction of cyanide radicals with nitric oxide. The latter diffuses back from the oxygen side of the flame where it is formed, but the overall result is that a proportion of the fuel‐N is converted to molecular nitrogen before it can be converted to nitric oxide.
Combustion products of polymeric materials. 2—Test chamber CAB 650
Authors: Michal Jan 
Published: December 2004

AbstractA chamber has been designed which allows total assessment of products formed during the thermal stressing of polymer material samples. The chamber is of oval shape and creates an infinite track for the movement of products formed in the course of the thermal degradation process. It allows the complete analysis of the products to be carried out to monitor the contents of the most important of them, to determine the oxygen content, to measure the optical density of smoke and to measure the temperature inside the chamber in the course of the experiment. The chamber was used for testing the combustion products of polyethylene, polypropylene, polystyrene and polyamide.
Comparative study of the toxicity of combustion products from flame retardant and untreated materials
Authors: Herpol Claire 
Published: December 2004

AbstractFire retardants improve reaction to fire characteristics such as ignitability and flame propagation. This paper presents the toxicological results of tests performed on eleven pairs of untreated and treated materials, including woods, synthetic materials and textiles (both natural and synthetic). It is shown that the effects of fire retardants on toxicity results can be variable. In addition, the problem of the use of toxicity results is discussed more generally.
Rate of heat release measurements with the Swedish box test
Authors: Holmstedt Göran 
Published: December 2004

AbstractThe Swedisn box apparatus was modified to include an oxygen analysis of the exhaust gases to be compared with the conventional exhaust gas temperature measurement. A slow‐burning material shows good correlation between the temperature measurement and the rate of heat release. A fast‐burning material, however, consumes all the available oxygen, and the temperature measurement becomes a measure of only the thermal properties of the material.
Predicting flash fire protection of clothing from laboratory tests using second‐degree burn to rate performance
Authors: Behnke W. P. 
Published: December 2004

AbstractLaboratory tests have been developed that evaluate realistically the protective performance of clothing materials and garments. Test conditions are chosen to stress the high temperature resistance of materials in the same manner as in an industrial flash fire exposure. A second degree burn in human tissue is used as the criteria to ate performance of materials. Test results have been correlated between the small‐scale lab swatch test and a full‐scale instrumented manikin garment test, and these results related to industrial experience. The TPP lab test has been found useful in evaluating the performance of candidate materials as replacement for existing materials with known acceptable protective performance. It can be used to specify the level of protection needed in a garment when the intensity of the exposure hazard is known. Also, the test is especially useful for developing new materials and selecting candidates for additional field testing.
Specification of combustible materials for passenger train design
Authors: Allender Peter J. 
Published: December 2004

AbstractThe general nature of fire problems on energy‐conservative passenger trains is described, including a description of vehicle structures and lightweight design. Effects of high energy demand, tunnels and high maximum speeds on fire safety are outlined. The considerations used in design analysis are described, beginning with the development of a ‘worst‐case fire scenario’. Typical combustible materials are considered and some of the reasons for choices are given. Notes on cavity and chimney effects emphasize the importance of clear objectives. Structural fire resistance is examined, and the basis of conventional recommendations analysed. The application of British Standard 6336 guidelines on fire tests and hazard assessment is examined. Limitation of fire load density is described, and some problems of calorific value determination outlined. Sources of ignition and hazards from passengers are defined. Flammability and flame‐spread control are discussed, and rate of heat release is referred to in the context of fire behaviour. Problems of passenger escape linked to flashover, smoke and combustion gases are dealt with briefly.
Characterization of the burning behaviour of polymeric materials
Authors: Paul K. T. 
Published: December 2004

AbstractMeasurements of the limits of flaming and smoldering combustion and relative rates of burning under elevated temperatures and oxygen‐depleted conditions have been used to characterize the fire behaviour of polymeric materials using a semi‐empicical approach (based on scientific theory) in terms of Power Law Indices. The work was based on modified current tests; namely the Limiting Oxygen Index (ASTM D2863) at elevated temperatures and the Setchkin Flash and Self‐Ignition Test (ASTM D1929) modified to operate in oxygen‐depleted atmospheres and to record rate of weight loss. Results show that the relative flammability and rate of burning of materials can change markedly with fire environment, and confirms the need to test materials lunder conditions representative of those of the anticipated end‐use hazard.
Radiative ignition of thermoplastic and charforming materials
Authors: Clark Ferrers R. S. 
Published: December 2004

AbstractSmall samples of poly(methyl methacrylate), red oak and possibly low‐density polyethylene ignite under the influence of thermal radiation with a propensity that increases with the area irradiated, consistent with ignition requiring that the lower flammability limit of pyrolysis gases be reached. The time to self‐extinction of small samples of charring, burning materials (low‐density polyethylene, red oak and possibly polycarbonate) in the absence of external radiant flux increases with burning area, suggesting that the increased absorptivity of char increases the importance of radiative feedback.
Hazard assessment techniques used in the chemical industry and their possible uses elsewhere
Authors: Simmons R. F. , Tyler B. J. 
Published: December 2004

AbstractThe traditional methods used for the identification and assessment of hazards in the chemical industry are based on experience, but increased economic and environmental restrictions on its operations have required the development of other methods to ensure that an acceptable level of safety is maintained. The present paper briefly reviews the traditional methods, describes in mire detail the basis of the newer methods, namely hazard and operability studies and hazard analysis, and considers how they might be more widely used in assessing fire hazards.
A review of products evolved from heated coal, wood and PVC
Authors: Hurst Nichoas W. , Jones T. Alwyn 
Published: December 2004

AbstractA review is presented of the gaseous combustion and pyrolysis products evolved from coal, wood and PVC. Information has been collated on the range of products evolved, the temperatures of evolution and the effect of different ambient conditions (e.g. oxidizing of inert conditions). The data for coal have been subdivided into those from which rates of gas evolution have been or can be derived and those from which this is not possible. Probable decomposition routes for PVC and for wood are discussed. Although all three materials have been widely studied, the correlation between the work of different authors in not always good. The data obtained are dependent on the form of the experiment, and there are gaps in the information available, especially information on the rates of evolution of products of products as a function of temperature.
Analysis of gases evolved from heated coal, wood and PVC conveyor belt their effect on zinc oxide single‐crystal semiconductor gas sensors
Authors: Hurst Nicholas W. , Jones T. Alwyn , Mann Brenda , van Ewyk Robert L. , Walden Paul 
Published: December 2004

AbstractAn analysis, using gas chromatography and gas chromatography‐linked mass spectroscopy, of the major products evolved as a function of temperature from coal, wood and PVC conveyor belting is described. The effect of these products, both collectively and as individual species, on the electrical properties of zinc oxide gas sensors has been investigated: the conductance of the sensors was measured in air containing either the total products evolved from the heated materials or the individual products eluted from a gas chromatographic column. Thus, the products from the different materials which make up the total zinc oxide gas sensor response at different material temperatures were identified. For coal dust heated in air the sensors responded to aromatic hydrocarbons H2 and CO, which were evolved between 100° and 200°C. For coal heated in nitrogen the sensors responded to the aromatic hydrocarbons evolved between 100° and 170°C. For PVC conveyor belt heated in air, the low temperature response was to the low levels of HCl evolved below 200°C. Finally, for hardwood dust heated in air the sensors responded primarily to the acid vapour evolved between 170° and 200°C.
Flammability testing state‐of‐the‐art
Authors: de Ris John 
Published: December 2004

AbstractTraditional material‐flammability tests are discussed in terms of their empirical foundation and oversimplified interpretation of fire phenomena. More recent rate of heat‐release tests overcome some of these problems by measuring a material's response to different levels of fire exposure. However, no existing small‐scale tests are sensitive to the radiant emission from the material's own flames. This radiant emission controls large‐scale fire hazards. As a result, existing flammability tests canot be xpected to adequately characterize large‐scale hazards. Some new approaches to this problem are discussed and a specific bench‐scale test method is suggested which may overcome the identified problems of existing test methods.
Modelling of furniture experiments with zone models
Authors: Blomqvist Jan , Andersson Berit 
Published: December 2004

AbstractThe Harvard Computer Fire Code Mark V has been used to simulate full‐scale furniture fires. Simulations were run with one sofa burning in the open and another burning in a small room. To obtain better agreement between experiment and simulation, changes were made in the code to include heating of the lower surfaces in the room. A simulation of a mattress test, conducted at NBS, is included. Comparison with a zone model using a different plume equation is also presented.
Acidic volatiles from overheated polymeric materials
Authors: Humphreys Hazel , Christopher A. J. 
Published: December 2004

AbstractPrevious work on the emission of smoke and fumes from overheated aircraft interior materials has included simple monitoring of acids and alkalies by means of a glass electrode in a water‐bubbler. In order to put these measurements on a quantitative basis and as part of an attempt to assess the significance of acidic or alkaline fumes in terms of irritant effects, a two‐way pH‐stat automatic titration apparatus is now used. A small sample of material is heated at a controlled rate to 500°C in a stream of flowing air. The effluent is bubbled through water and automatically titrated for acids or alkalies. The temperatures at which these emissions occur and their amounts can be measured. Good recoveries of acids, alkalies and of both evolved consecutively have been achieved. To assess the utility of the apparatus for actual materials, the acid evolved from various types of PVC was compared. The emissions from three different nylons and from a composite cable were also investigated. Reference materials with various known additives are now being examined by the method and comparisons with irritancy measurements are being made. Ion‐chromatography will be used to study the individual acid evolved.