bluuebunny/crossref_metadata_2025_split huggingface dataset:
Vergleich verschiedener verfahrenstechnischer Konzepte der präparativen Flüssigchromatographie
Authors: Heuer Christian , Kniep Hagen , Falk Thomas , Seidel‐Morgenstern Andreas 
Published: December 2004

AbstractLiquid chromatography utilising porous solid phases (adsorption chromatography) is one of the most powerful and versatile methods of modern analytical chemistry. Its widespread application is due in part to the development of a broad range of combinations of solid stationary and liquid mobile phase. Normal phase and reverse phase chromatography with pure and chemically modified silica gel, respectively, affinity chromatography, and ion chromatography can be cited as examples [1]. In addition to its use as an analytical method, chromatography is becoming increasingly important in the preparative‐scale isolation of pure substances in the pharmaceutical industry, in biotechnology, and in the production of fine chemicals. In many cases, the required purity criteria can only be met with chromatographic techniques, as in the resolution of racemates. From a process engineering viewpoint, a better understanding of concentration profile deformations caused by intended overloading of separation columns has recently been acquired [2]. In particular, this cncerns the description of displacement and entrainment effects associated with the competing adsorption. A series of alternative operating modes has been developed and used [3] for enhancing yields and productivities. In spite of a number of attempted comparative studies [4] there is a lack of quantitative information about optimized process. This article aims to compare four different process engineering concepts of preparative chromatography on the basis of a uniform theoretical model.
Umsetzung des Gewässerschutzes in der Praxis bei Instandhaltungs‐ und Reinigungsarbeiten an Chemieanlagen
Authors: Eipper Gunter 
Published: December 2004

AbstractThe water management law (WHG) and the plant regulations of the German federal states stipulate boundary conditions which must be observed during work on plants handling substances which are hazardous to water. There are various possibilities for the implementation of the legal provisions. During maintenance and cleaning work on chemical plants, our aim must be to provide effective protection of our waterways and to ensure that the operating procedures are also efficient in economic terms. Procedures which have been tried and tested in practice are described. The annex gives a compilation and explanations of extracts from legal texts from the field of water legislation which are of relevance in carrying out such work.
Anwendung von Magnéli‐Phasen des Titandioxids in der elektrochemischen Technologie
Authors: Zweynert M. , Döring H. , Garche Jürgen , Enghardt K. , Wiesener K. 
Published: December 2004

AbstractUse of Magneli Phases of Titanium Diooxide in Electrochemical Technology. Magneli phases of titanium oxides are known to have many interesting properties such as a conductivity comparable to that of graphite, a high level of chemical stability, and large overpotentials for gas evolving reactions. In this paper the possibilities for synthesis of pure Magneli phases are reported and the influence of various experimental parameters on the electrochemical properties is discussed. Several chemical, electrochemical, physicochemical, and physical experiments were performed. The opportunities for technological applications in the field of electroplating, in the recycling of process solutions, as supporting substrates for electrocatalysts, and as collector materials are considered.
3D‐Geometriebestimmung in Industrieanlagen
Authors: Rieks Hans‐Joachim 
Published: December 2004

Abstract3D‐Geometry Determination in Industrial Plant.Nowadays, chemical and other industrial process plant is expected to meet increasingly stringent demands with respect to performance parameters and service life. Exact knowledge and comprehensive documentation of plants are of increasing significance in the various tasks involved in their operation, maintenance, modification and expansion. In developing this documentation, industrial measuring systems and the process of close‐range photogrammetry are the ideal tools for an appropriate determination of 3D geometry, yielding results which are suitable for many applications. A distinction is made between the highly accurate determination of the dimensions of special components and the actual as‐built plant documentation pertaining to larger plant segments or entire plants. A detailed description of the framework conditions and the processes of determining 3D geometry in industrial plant can be found in the VGB bulletin of the same title [1].
Absicherung von Zulaufreaktoren durch Überwachung der Reaktantenakkumulation mittels On‐line‐Energiebilanzierung
Authors: Schimetzek Ralf , Giesbrecht Hartmut 
Published: December 2004

AbstractSafe Operation of Semi‐Batch Reactors by Supervising the Accumulation of Reactants Through Online Energy Balance.An essential part of the strategy for ensuring safe operating conditions for semi‐batch reactors is the permanent guarantee of an admissible accumulation of reactants. Thus, even in case of a failure or a breakdown of the cooling system or the agitator, the maximum possible pressure and temperature in the reactor still remain within their permissible limits. The energy balance method makes it possible to monitor online the reactant concentration and to limit the accumulation by switching off the feed of reactant in time. Practical experience with a production plant is presented in which, over a period of 2 years, numerous process cycles were calculated and subjected to comparative analysis. The results show that the reproducibility as well as the accuracy of calculation are high and that the energy balance method can be regarded as reliable. In addition, recommendations for the implementation of this safety strategy as a reliable tool in plants are obtained. On this basis, the energy balance method provides additional information about the process and, thus, can provide an increase of plant safety and product quality by maintaining process availability.
Einsatz von Biocompounds zum Abbau chlorierter Kohlenwasserstoffe in der Grund‐ und Abwasserreinigung
Authors: Briesovsky Annett , Jank Manfred , Köser Heinz , Schnabel Rainer 
Published: December 2004

AbstractUse of Biocompounds for Degradation of Chlorinated Hydrocarbons in Treatment of Ground Water and Waste Water.Process engineering approaches to waste water treatment using immobilised microorganisms (MO) permit greater biomass concentrations in the bioreactor and hence higher conversions per unit time. Moreover, the biofilms formed assure favourable conditions for degradation specialists. Immobilisation of microorganisms is feasible on both static and freely mobile supports. Use of the latter permits modification of the flow conditions in the reactor.
Twin boundaries as crack nucleation sites
Authors: Blochwitz C. , Tirschler W. 
Published: December 2004

AbstractCoherent twin boundaries (TBs) in f.c.c. metals are considered to have low energy. Nevertheless, even TBs are preferred sites for crack nucleation in materials loaded at very small alternating plastic strain amplitudes (high cycle fatigue). In the present paper, the mechanism of short crack propagation starting from TBs was studied for medium amplitudes and described taking into account both elastic and plastic anisotropy effects. A strong dependence of the TB crack density on the meso‐texture of the material was found. The twin part of the meso‐texture was described by the <111> rotation vectors of the TBs observed using the EBSD technique in the SEM. The rotation vectors of the damaged TBs were arranged in a “damaging cone” around the specimen axis. The risk of TB cracks in texturized rolling plates can be reduced by a favourable alignment of the specimen in the rolling plate avoiding the damaging cone of rotation vectors. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Material analysis with X‐ray microdiffraction
Authors: Friedel F. , Winkler U. , Holtz B. , Seyrich R. , Ullrich H.‐J. 
Published: December 2004

AbstractSteel has continued to develop its status as a lightweight construction material for the design of vehicle bodies, most recently with the development of multi‐phase steel. With a specific mixture of different phases in the steel microstructure, multi‐phase steel combines high stability with good forming capacity. The characterisation of the complex structure of the multi‐phase steel represents a challenge for metallurgists. For some years a new generation of X‐ray diffractometers with two‐dimensional (area) detectors and apparatus for local dissolved measurements are available to customers [5]. This paper reports the applications and advantages of the modern X‐ray diffractometry method. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Clinical significance of monoclonal B cells in cerebrospinal fluid
Authors: Nowakowski Grzegorz S. , Call Timothy G. , Morice William G. , Kurtin Paul J. , Cook Rachel J. , Zent Clive S. 
Published: December 2004

AbstractBackgroundMorphologically malignant lymphocytes in the cerebrospinal fluid (CSF) are highly suggestive of central nervous system involvement by lymphoid malignancy. Although flow cytometry is increasingly used to detect a monoclonal B‐cell population in the CSF, the significance of this finding in the absence of morphologically identifiable malignant cells is unknown.MethodsWe reviewed CSF flow cytometric results in 32 patients studied at a single institution over 5 years and identified patients who had monoclonal B‐cells in the CSF. Clinical presentation and course were reviewed.ResultsTwelve patients had a monoclonal B‐cell population in the CSF, but only three had clinical evidence of malignant CNS disease. Of the other nine patients, 4 had nonmalignant neurologic disease and five had a lymphoproliferative disorder: chronic lymphocytic leukemia (n = 4) and mantle cell lymphoma (n = 1). In patients who had chronic lymphocytic leukemia and mantle cell lymphoma, the monoclonal B‐cell population was small and had an immunophenotype identical to that of circulating malignant B cells. None of these nine patients developed clinical evidence of malignant CNS involvement during follow‐up.ConclusionIn patients who have indolent B‐cell malignancies, the presence of monoclonal B cells in the CSF may not be diagnostic of clinically significant CNS involvement by a lymphoid malignancy. © 2004 Wiley‐Liss, Inc.
The oxidative pyrolysis of plastics
Authors: Edgerley Peter G. 
Published: December 2004

AbstractExperiments using a thermobalance, a hot‐plate and a moving furnace have all shown that polymers can evolve oxidation products in air even at moderate temperatures. These gases can include carbon monoxide, formaldehyde and acrolein. The amounts are generally low except near the very top of the temperature range used in some processes. Tests in the vicinity of three different extruders have confirmed some of these small‐scale findings but also showed that the evolved gases were adequately handled by the ventilation installed. The evolution of other gases in certain cases has also been briefly studied. Some measure of the heat evolved in oxidative pyrolysis has also been obtained for polyethylene. The polymers investigated were low density and high density polyethylene, poly(ethylene vinylacetate), polypropylene, poly(vinylonitrille) polypropylene, poly(vinylchloride), polystyrene, poly(methylmethacrylate), polycarbonate, poly(ethylene terephthalate), nylon 6‐6, acrylonitrile/butadiene/styrene and one nature material (wood).
An analysis of smoldering fires in closed compartments and their hazard due to carbon monoxide
Authors: Quintiere J. G. , Birky M. , Macdonald F. , Smith G. 
Published: December 2004

AbstractA review was made of smoldering fire experiments conducted in closed rooms and buildings. The results were summarized by tabulating maximum levels of CO, the time integral of CO concentration (‘dose’), CO2, temperature rise and oxygen consumption. A hazard time based on the attainment of a CO dose equal to 4.5% CO‐minutes and the time for transition to flaming were also tabulated. The likelihood of reaching a critical CO condition during smoldering seems to be comparable with the likelihood of having transition to flaming occur. A theoretical model, requiring inputs of CO production rate and energy release rate, was executed and compared with available data. The theoretical results for CO concentration as a function of time were in good agreement with the experimental data. The model offers a means of extrapolating test data to compartments of various size in order to assess the general hazard of CO due to smoldering.
Smoke formation from burning polystyrene and its suppression
Authors: Chalabi R. , Cullis C. F. 
Published: December 2004

AbstractStudies have been made of the influence on smoke generation from polystyrene of the incorporation of a number of apparently inert solids, the smoke‐producing tendency being expressed in terms of the maximum specific optical density of smoke per unit weight of polymer consumed. Of the compounds investigated, by far the most efficient smoke suppressant is pyrogenic silica, the effect of which is, over a wide range, directly proportional to the total surface area of the material introduced. Examination of partially burned polystyrene‐pyrogenic silica composites reveals the presence at the surface of a hard rigid skin, which is not observer with polystyrene alone of with polymer samples containing other additives. The formation of a protective skin is also indicated by the kinetics of forced burning of these composites where the weight loss is a linear function of log time and by measurements of the rate of change of thickness of polymer samples during combustion. Thermogravimetric experiments in which polystyrene and pyrogenic silica are heated in contact with one another show that the silica encourages the formation of a carbon residue from the polymer. A mechanism of skin production is proposed which involves the build‐up of layers of tangential spherical silica particles cemented together by cross‐linked polystyrene.
Thermal degradation studies of molybdenum containing polyester thermosets
Authors: Das M. , Haines P. J. , Lever T. J. , Skinner G. A. 
Published: December 2004

AbstractA study has been made of the effect of molybdenum trioxide on the thermal degradation of a series of chlorinated and brominated polyester thermosets. Like antimony oxide, it showed flame retardant activity in all the halogenated polyesters. It was shown to affect the char yield, and the temperature and weight loss of each degradation step. X‐Ray diffraction studies of the degraded dibromoneopentyl glycol polyesters showed that in air a near‐quantitative yield of molybdenum trioxide was present above 550 °C. Some dioxide was present before the final char oxidation step occurred. In a nitrogen atmoshphere the trioxide was reduced to the dioxide at first, but this finally reacted to give the carbide at around 900 °C. Infrared spectroscopy showed that inclusion of the molybdenum trioxide resulted in structural changes in the high‐temperature polyester residues which were more prominent when bromine was present. Elemental analysis of the residues indicated that the presence of the trioxide in the brominated polyesters accelerated the release of bromine at high temperatures and confirmed its char‐promoting tendencies.
Fire deaths in the United Kingdom 1976‐82
Authors: Anderson R. A. , Willetts P. , Harland W. A. 
Published: December 2004

AbstractA study of fire deaths in the Glasgow area has been extended to the rest of the United Kingdom in order to assess the applicability of the conclusions reached in the Glasgow study to the whole country. With assistance from pathologists in a number of other areas, 71 cases were included in the study, covering both pathology and toxicology of the deaths where possible. In both the Glasgow and UK studies, most of the fire deaths occurred in dwelling‐house fires. These and other demographic characteristics were in agreement with national fire statistics. The principal features of pathology in this study were burns (79 per cent of cases), respiratory system injury (72 per cent of cases) and soot deposition in the respiratory tract (96 per cent of cases), and these reflected a similar incidence in Glasgow study. Carbon monoxide was considered to be the cause of death in 51 per cent of the deaths in this study and to be implicated in the death of 37 per cent of the other cases (54 per cent and 31 per cent respectively in Glasgow). Cyanide was estimated to be a significant factor in 33 per cent of the deaths in the UK study (24 per cent in Glasgow). Alcoholic intoxication was found to be a significant additional factor in Glasgow but was much less prominent in the other areas of the UK. It concluded that, with the exception of alcohol, the results of the Glasgow study are valid for the UK as a whole.
Fire behaviour of upholstered furniture—an experimental study
Authors: Andersson B. , Magnusson S. E. 
Published: December 2004

AbstractA series of experiments for studies of flammability characteristics of upholstered furniture is presented. The series comprises 53 experiments on a reduced scale and 11 full‐scale experiments in an extensively instrumented room. Results are presented from measurements of rate of heat release and smoke production. The experiments indicate that ignitability can be considerably decreased by careful choice of the upholstery materials.
Toxic gas and smoke measurement with the British Fire Propagation test. I: Test conditions
Authors: Brown S. K. , Martin K. G. 
Published: December 2004

AbstractNo standard method has been developed for measureing the evolution of specific toxic gases from building lings when involved in fire. The British Fire Propagation test (BS 476 Part 6) operated in an instrumented room has been proposed for this purpose previously but has not found general acceptance. It is considered further in this report, which investigates the movement and measurement of smoke and specific fire gases under different conditions of room stirring and the effect of the latter on fire propagation indexes. Stiring has been found to have no statistically significant effect on fire propagation indexes provided that the effects of this on calibration of the apparatus are taken into account. Stirring also had little effect upon smoke production per se. Under unstire conditions smoke and toxic gases stratify in the same layer early in the test, and measurement of their production at any single room location will be subject to the location, the way the room influences stratification and how the room is instrumentee, as well as by the prpduct performance. Under stirred room conditions smoke and toxic gases are evenly distributed and product performance can be assessed more simply from concurrent measurements of fire, smoke and toxic gas parameters. The latter procedure is proposed for obtaining relative data on building linings and for examination in further studies for correlation to room and corridor burns.
Toxic gas and smoke measurement with the British Fire Propagation test. III: UPTV formulations with reduced HCl evolution
Authors: Brown S. K. , Martin K. G. 
Published: December 2004

AbstractA range of basic fillers has been incorporated into UPVC formulations and assessed for effectiveness in suppressing HCl evolution and influence on other fire properties. Investigations were carried out with the British Fire Propagation test (BS 476 Part 6) in a room previously used for assessing the fire behaviour of UPVC building products. HCl evolution was also studied following degradation in a pyrolysis tube furnace. Despite notable differences in these methods of assessment, good correlation was found between them. Varying degrees of HCl suppression were obtained and for formulations containing stronger bases effectiveness was found between them. Varying degrees of HCl suppression were obtained and for formulations containing stronger bases effectiveness was approximately stoichiometric to the amount of base present. Lithium hydroxide was thus the most effective HCl absorber on a weight basis. A formulation with 40 parts per hundred resin of this filler evolved only 2% of its theoretical HCl, although at the expense of increased fire propagation indexes. Smoke properties were not greatly influenced by the formulations. Precipitated calcite was considered the most promising acid‐absorbing filler for practical use. At 40 parts per hundred resin it reduced HCl evolution to 34% of theoretical and markedly delayed the onset of incapacitating HCl concentrations in the room, with little influence on fire propagation properties of the UPVC.
The combustion products of polymeric materials. III: GC–MS Analysis of the combustion products of polyethylene, polypropylene, polystyrene and polyamide
Authors: Mitera Jiǐí , Michal Jan 
Published: December 2004

AbstractA series of gas chromatographic–mass spectrometric analyses was carried out on polyethylene, polypropylene, polystyrene and polyamide in CAB 4.5 and CAB 650 chambers in the flaming and non‐flaming combustion mode. The combustion products formed were identified and used to characterize the combustion process in both chambers; procedures were selected for testing polymeric materials for the dangerous effects of their combustion products.
The composition and structure of solid char residues after thermal degradation of polystyrene, PVC and polyamide. Part I
Authors: Ševěček P. , Dvořák P. 
Published: December 2004

AbstractThe study of char residues after thermal degradation of synthetic polymers, especially the identification of their morphology, structure and chemical composition is presented in this paper. Special attention was focused on the polystyrene, PVC and polyamide char residues. By means of microscopy in reflected light and reflected polarized light the manifestations of optical anisotropy were observed. X‐ray analysis was used for the examination of the microstructure of PVC char residues carbonized at temperatures above 1000°C. For PVC char residues the electric resistivity was determined. The results have proved the close connection between the structure and properties of char residues and the intensity and course of thermal degradation of polymers.
The possibility of the evaluation of toxic and mutagenic effects of combustion products with the aid of Drosophila melanogaster files
Authors: Majek J. , Talapkova D. , Repka V. , Špilda I. , Košik M. 
Published: December 2004

AbstractThe use of Drosophila melanogaster files for testing of combustion toxicity is proposed with results from testing the effects of polyurethane combustion products.
An investigation of the flame‐retardant and smoke‐suppressant properties of tin (IV) oxide in unsaturated polyester thermosets
Authors: Cusack P. A. 
Published: December 2004

AbstractStudies have been carried out of the effects of (1) anhydrous tin (IV) oxide and (2)β‐stannic acid {hydrous tin (IV) oxide} on the flammability and smoke production of unsaturated polyesters into which halogen may be introduced as a reactive monomer during the resin synthesis. The results obtained provide evidence for a marked falme‐reatedant synergism between tin and halogen, accompanied by a significant reduction in smoke from the burning polymer. The hydrous tin compound was found to be more effective than the anhydrous SnO2 both as a flame retardant and a smoke suppressant. At a 2% incorporation level β‐stannic acid gave polymers with LOIs of up to ca 30 and reductions in smoke density of 50% or more compared with the standard non‐halogenated resin. The mode of action of the tin compounds appears to involve both the condensed and vapour phases. In view of the generally accepted low toxicity of inorganic tin chemicals their possible use as fire‐retardant additives for polymer systems should merit serious consideration.