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Product Properties (product + property)
Selected AbstractsVision system for on-line characterization of paper slurry ,INTERNATIONAL JOURNAL OF IMAGING SYSTEMS AND TECHNOLOGY, Issue 4 2000Hamed Sari-Sarraf This paper presents a detailed description of a vision system that detects and localizes the nonuniformities that appear on the paper slurry (wood fiber and water mixture) at the wet end of a paper machine. Specifically, the system monitors the paper slurry as it exits the headbox and alerts the operators of any event (e.g., streaks) that disrupts the otherwise homogeneous background. These events affect crucial product properties such as formation. A poor formation results in thick and thin spots on the sheet and impacts its strength and printability. This paper describes the vision system in terms of its hardware modules, as well as the image processing algorithms that it utilizes to perform its function. The system acquires intensity and topographic information from the scene. It uses texture-based features for the detection and facet-based descriptors for the localization of the nonuniformities. In addition to being tested in a laboratory environment, a prototype of this system was constructed and deployed to a paper mill, where its performance was evaluated under realistic conditions. Installed on a fourdrinier paper machine, running at 480 m/min and producing linerboard material, the vision system monitored about a 1 m wide area and successfully detected and localized slurry streaks. Published 2001 John Wiley & Sons, Inc. Int J Imaging Syst Technol, 11, 231,242, 2000 [source] Physical characterization of starch extrudates as a function of melting transitions and extrusion conditionsADVANCES IN POLYMER TECHNOLOGY, Issue 4 2004Stéphanie Blanche Abstract The objective of this study was to investigate the relationships between starch melt transition characteristics, extrusion conditions, and final product properties. Cornstarch was extruded using a corotating twin-screw extruder at varying moisture content, medium/high screw configuration, and 300/400-rpm screw speeds. Extrudates were evaluated for bulk density, expansion ratio, cell structure, bending strength, thermal and pasting properties. Temperature change (,T) was defined as the temperature difference between the native starch melting temperature and its melt temperature just behind the die during extrusion at a given moisture content. ,T was significantly affected by starch moisture content and mechanical shearing, which controlled the melting behavior of the starch in the barrel. Amylose,lipid complex formation during extrusion increased as ,T increased and leveled off at ,T of about 20°C. Pasting peak viscosity of the starch extrudates decreased as ,T increased and leveled off at ,T of about 15°C. Within the same range of mechanical shearing intensity, extrudate bulk density and bending strength decreased linearly as ,T increased. Extrudate expansion was negatively correlated to bulk density. © 2004 Wiley Periodicals, Inc. Adv Polym Techn 23: 277,290, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.20017 [source] Modification of polypropylene by melt vibration blending with ultra high molecular weight polyethyleneADVANCES IN POLYMER TECHNOLOGY, Issue 3 2002Kejian Wang Abstract A novel vibration internal mixer was used to prepare polypropylene/ultra high molecular weight polyethylene PP/UHMWPE blends with two additional adjustable processing parameters (vibration frequency and vibration amplitude) as compared with those prepared in the steady mode. Microscopy, mechanical tests, and differential scanning calorimetry showed that vibration influenced the blend morphology and the product properties. The good phase homogeneity of the blends might be due to the variation of shear rate either spatially or temporally in blending. Additionally, the vibration internal mixer could be used to analyze the dependency of viscosity on the shear rate. Vibration enhanced the interpenetration of UHMWPE into PP and vice versa. Subsequently, the formed crystals of two components were connected, and there was epitaxy between PP and UHMWPE crystals. Moreover, the crystalline aggregates, with the amorphous UHMWPE, formed a complex network-like continuous structure, which improved the elongation ratio at the break and the yield strength. The higher the vibration frequency and/or the larger the vibration amplitude at a fixed average rotation speed of the mixer, the more significant these effects were. The larger amount of the connected crystals, especially of , form of PP in the bulk , form PP as well as with the continuous phase structure, led to a higher tensile properties of PP/UHMWPE vibration blended. © 2002 Wiley Periodicals, Inc. Adv Polym Techn 21: 164,176, 2002; Published online in Wiley Interscience (www.interscience.wiley.com). DOI 10.1002/adv.10020 [source] Safe-steering of batch process systemsAICHE JOURNAL, Issue 11 2009Siam Aumi Abstract This work considers the problem of controlling batch processes to achieve a desired final product quality subject to input constraints and faults in the control actuators. Specifically, faults are considered that cannot be handled via robust control approaches, and preclude the ability to reach the desired end-point, necessitating fault-rectification. A safe-steering framework is developed to address the problem of determining how to utilize the functioning inputs during fault rectification to ensure that after fault-rectification, the desired product properties can be reached upon batch termination. To this end, first a novel reverse-time reachability region (we define the reverse time reachability region as the set of states from where the desired end point can be reached by batch termination) based MPC is formulated that reduces online computations, as well as provides a useful tool for handling faults. Next, a safe-steering framework is developed that utilizes the reverse-time reachability region based MPC in steering the state trajectory during fault rectification to enable (upon fault recovery) the achieving of the desired end point properties by batch termination. The proposed controller and safe-steering framework are illustrated using a fed-batch process example. © 2009 American Institute of Chemical Engineers AIChE J, 2009 [source] Effect of calcium carbonate particle size on PVC foamJOURNAL OF VINYL & ADDITIVE TECHNOLOGY, Issue 2 2006Bahar Azimipour Calcium carbonate is the predominant filler used in polyvinyl chloride compounding. Selection of fillers, as in the case with other compounding ingredients, involves consideration of available types and their effects on processing, product properties, and economics. In this article the effect of the particle size of CaCO3 on the properties of PVC foam is investigated. The study analyzes the correlation between fusion time, extrusion torque, and foam density as well as foam cell structure with the filler particle size. J. VINYL. ADDIT. TECHNOL. 12:55,57, 2006. © 2006 Society of Plastics Engineers. [source] Monitoring of Emulsion Polymerisation Processes using Ion Mobility Spectrometry,A Pilot StudyMACROMOLECULAR REACTION ENGINEERING, Issue 2-3 2009Wolfgang Vautz Abstract Online monitoring of monomer concentrations in (semi-) batch emulsion polymerisation reactors is important for safe and cost-efficient operation of production plants. In the present pilot study, ion mobility spectrometry was applied for monitoring the concentration during emulsion polymerisation of vinyl acetate (VA) using UV light for ionisation of the headspace of a continuous sample flow. Satisfactory sensitivity for online process monitoring of the monomer concentration in the reactor was observed (LOD 400 ng,·,L,1 air, equivalent to <1%). Furthermore, it is possible to discriminate between VA and other common monomers [butyl acrylate (BA), methyl methacrylate (MMA)]. Using the more efficient , -radiation ionisation, monomer concentration could be measured even in the final latex as a measure of the final product properties. [source] Simultaneous Controllability of PSD and MWD in Emulsion PolymerisationMACROMOLECULAR REACTION ENGINEERING, Issue 5 2008Stephen J. Sweetman Abstract A sensitivity study of particle size distribution (PSD) and molecular weight distribution (MWD) responses to perturbations in initiator, surfactant, monomer and chain transfer agent in a semi-batch emulsion polymerisation is presented. The objective is to provide a systematic study on the ability to simultaneously control both PSD and MWD, towards inferential control of end-use product properties. This would lead towards identification of the practical feasible regions of operability. All inputs appeared to have an intrinsic and simultaneous influence on end-time PSD and MWD. Trends shown in experimental results have been explained in a mechanistic sense and also compared to simulation results from a combined PSD/MWD population balance model. The preliminary comparison between experiment and simulation highlights areas to be focussed on with respect to model improvement. [source] Reliability qualification of semiconductor devices based on physics-of-failure and risk and opportunity assessmentQUALITY AND RELIABILITY ENGINEERING INTERNATIONAL, Issue 2 2002W. H. Gerling Abstract Qualification frequently is a time-critical activity at the end of a development project. As time-to-market is a competitive issue, the most efficient qualification efforts are of interest. A concept is outlined, which proactively integrates qualification into the development process and provides a systematic procedure as a support tool to development and gives early focus on required activities. It converts requirements for a product into measures of development and qualification in combination with a risk and opportunity assessment step and accompanies the development process as a guiding and recording tool for advanced quality planning and confirmation. The collected data enlarge the knowledge database for DFR/BIR (designing for reliability/building-in reliability) to be used for future projects. The procedure challenges and promotes teamwork of all the disciplines involved. Based on the physics-of-failure concept the reliability qualification methodology is re-arranged with regard to the relationships between design, technology, manufacturing and the different product life phases at use conditions. It makes use of the physics-of-failure concept by considering the potential individual failure mechanisms and relates most of the reliability aspects to the technology rather than to the individual product design. Evaluation of complex products using common reliability models and the definition of sample sizes with respect to systematic inherent product properties and fractions of defects are discussed. Copyright © 2002 John Wiley & Sons, Ltd. [source] Modelling and process development for gaseous separation with silicone-coated polymeric membranesTHE CANADIAN JOURNAL OF CHEMICAL ENGINEERING, Issue 2 2008Xin Jiang Abstract This paper proposes a permeance equation for vapour,permanent gas mixtures in a silicone-coated polymeric membrane. The equation was derived from the Arrhenius relationship by combining an apparent activation energy and interaction parameter. Accurate values of transmembrane flux were obtained by incorporating this proposed equation, which was dependent on temperature and feed composition. The equation parameters were correlated with the experimental data of eight mixtures consisting of hydrocarbons such as ethylene, ethane, propylene and propane with nitrogen covering a broad range of temperature and concentration. A numerical integration scheme was used for developing a crossflow model utilizing the above equation, which allowed the estimation of product properties including the membrane plasticization cases. The study also reports examples of implementation of this approach in potential industrial applications for the recovery of ethylene and propylene from nitrogen. Cet article propose une équation de permeance pour les mélanges vapeur,permanents de gaz dans une membrane polymère enduite de silicone. L'équation a été dérivée du rapport d'Arrhenius en combinant une énergie d'activation et un paramètre apparents d'interaction. Des valeurs précises du flux de transmembrane ont été obtenues en incorporant cette équation proposée, qui dépendait de la composition en température et en alimentation. Les paramètres de l'équation ont été corrélés avec les données expérimentales de huit mélanges se composant des hydrocarbures tels que l'éthylène, l'éthane, le propylène et le propane avec de l'azote couvrant une large gamme de la température et de concentration. Un arrangement numérique d'intégration a été employé pour développer un modèle de croisement de flux utilisant l'équation ci-dessus, qui a permis l'évaluation des propriétés de produit comprenant les cas de plasticization de membrane. L'étude indique également des exemples d'exécution de cette approche dans des demandes industrielles potentielles de rétablissement d'éthylène et de propylène de l'azote. [source] Effects of operating conditions on particle size in sonocrystallizationASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 4 2010Hussein Oubani Abstract This work presents systematic investigations on sonocrystallization to elucidate the effects of key variables on sonocrystallization product properties. A novel continuous flow sonocrystallization apparatus was used to prepare NaCl microparticles from a NaCl,ethanol,water antisolvent system. By implementing a full factorial experimental design, we investigated the effects of ultrasonic power (75,225 W), antisolvent feed rate (0.5,6.5 l/h), system flow rate (2.8,4.1 l/min) and sonication time (5,30 min) on product crystal size. Data from these experiments were regressed to develop an empirical model that was found to be in agreement with experiments. The model identified the interaction between sonication power and system flow to be rather significant. Model simulations found that particle size decreases when antisolvent feed rate or ultrasonic power increases. This was found to be in contrast to increasing the system flow which resulted in larger particle sizes. The regression model was subsequently used to determine optimal operating conditions that minimize mean size, as smaller sizes are commonly required for pharmaceuticals such as for inhalation particles. These optimal values were found to be as follows: antisolvent flow rate = 6.5 l/h, power ultrasound = 225 W, system flow = 2.8 l/min and sampling time = 15 min. The optimal mean size predicted at these conditions was 28.6 ± 5.7 µm which is very close to the observed value of 27.6 µm. A high-speed camera was used to visualize the ultrasonic irradiation in the sonoreactor and was crucial in explaining the significant interactive effect of sonication power and system flow on crystal size. Copyright © 2010 Curtin University of Technology and John Wiley & Sons, Ltd. [source] In-situ Measurement of Primary Particle Sizes during Carbon Black ProductionCHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 9 2003S. Dankers During the production of carbon black monitoring of primary particle size plays an important role since this parameter determines product properties and is specified accordingly. For process control fast information about this size is absolutely necessary. In the work presented here it was investigated whether time-resolved laser-induced incandescence is suitable for on-line measurement of primary particle sizes of carbon black during the production process. The results obtained experimentally in industrial production and test reactors were compared with values for the specific surface area from laboratory analyses of sampled material. [source] Aerosole und ihre technische BedeutungCHEMIE-INGENIEUR-TECHNIK (CIT), Issue 12 2003S. Heidenreich Dr.-Ing. Abstract Aerosole , gezielt erzeugt oder unerwünscht gebildet , treten in vielen technischen Prozessen auf. So werden zum Beispiel Aerosole gezielt erzeugt, wenn Produkte, die aus feindispersen Feststoffen bestehen, in einem Gasphasenprozess (im weitesten Sinn) hergestellt werden. Partikelbildung und -wachstum im Aerosolzustand prägen dabei die Größe, Form und Struktur der Partikel und damit entscheidend die Produkteigenschaften. Aerosole können sich auch unerwünscht in Prozessen bilden. Dies führt zur Verunreinigung von Prozessgasen oder Produkten beziehungsweise zu erhöhten Beladungen von Abluftströmen. Kann die unerwünschte Aerosolbildung nicht vermieden werden, müssen wirkungsvolle Abscheideverfahren eingesetzt werden. Effiziente Abscheider sind auch zur Gewinnung von Produktpartikeln aus der Gasphase notwendig. Ob gezielt erzeugt oder unerwünscht gebildet, Aerosole müssen hochauflösend erfasst und charakterisiert werden. Dies erfordert eine entsprechend leistungsfähige Aerosolmesstechnik. Der Beitrag vermittelt einen Überblick über die technische Bedeutung von Aerosolen. Aerosols and Their Technical Significance Aerosols occur in many technical processes. For example, aerosols are formed to generate products of highly disperse solids in gas phase processes. Particle formation and growth in the aerosol state decisively determine the product properties by the size, shape, and structure of the particles. Undesired aerosol formation can also occur in technical processes. These undesired aerosols pollut process gases or products or increase the pollutant content of exhaust gases. If undesired aerosol formation cannot be avoided, efficient separation techniques have to be used. Efficient separators are also required to recover fine product particles from the gas phase. Moreover, aerosols, whether desired or undesired, have to be measured and characterized. This requires high performing measuring techniques. The paper outlines the technical significance of aerosols. [source] Chemischer Apparatebau im Aufbruch?CHEMIE-INGENIEUR-TECHNIK (CIT), Issue 5 2003E. Weiß Prof. Dr.-Ing. Abstract Die ACHEMA stellt eine eindrucksvolle Leistungsschau des Apparatebaus dar, die im engen Zusammenhang mit den epochalen Entwicklungen der Verfahrens- und Prozesstechnik steht. Dies ist ein günstiger Zeitpunkt, um über die Entwicklungschancen nachzudenken. Der Großanlagenbau hat in den letzten Jahrzehnten eine beträchtliche Korrektur erfahren, was sich besonders auf den deutschen Apparatebau ausgewirkt hat. Wirtschaftliche Zwänge lieferten einen zusätzlichen Anstoß für einen beachtlichen Schrumpfungsprozess. Der Apparatebau muss sich in der Zukunft auf zwei Standbeine konzentrieren: Hochqualifizierte Standardapparate und neuartige Produkte, die im engen Zusammenwirken mit der Verfahrenstechnik entwickelt werden müssen, um für neue Technologien und Prozessstrategien die erforderliche Hardware auf den Markt zu bringen. Der Beitrag nennt Gebiete, in denen sich der allgemeine technische Fortschritt manifestiert, aber auch aus der apparatetechnischen Sicht werden Anstöße vermittelt, wie ein gehobenes Qualitätsniveau der Produkte erreicht werden kann. Hierbei handelt es sich durchaus um Eigenschaften, die sich letztlich im wirtschaftlichen Ergebnis niederschlagen. Chemical Apparatus Engineering at a Turning Point? The ACHEMA conference is the leading international exhibition on chemical-apparatus engineering, closely connected with the epochal developments of chemical and process engineering. At the moment it is most timely to think about new opportunities of development. Large-scale plant engineering and general plant construction has experienced considerable improvement over the past decades, and the effects of these changes are particularly perceptible in the economic sector of German apparatus engineering. Economic pressures have given an additional impetus to a considerable shrinking process. Chemical apparatus engineering will have to focus on two main pillars in the near future: highly qualified standard and innovative products. Especially the latter must be developed in close interaction with chemical engineering in order to put the hardware required for new technologies and process strategies on the market. This article names the important fields of current general technical progress, showing that the main thrust is directed toward an elevated level of product quality that can be achieved through apparatus engineering. Such superior product properties are one important means to achieve higher profitability. [source] Virtuelle Produktmodellierung am Beispiel eines PumpenlaufradesCHEMIE-INGENIEUR-TECHNIK (CIT), Issue 1-2 2003F.-K. Benra Dr.-Ing. Abstract Durch die Verkürzung der Produktlebenszyklen werden die zur Verfügung stehenden Entwicklungszeiten entscheidend eingeschränkt. Es bleibt keine Zeit mehr für ein umfangreiches Erprobungsprogramm, bei dem die gewünschten Produkteigenschaften durch die Untersuchung und Abwandlung diverser Prototypen erzielt werden. Durch konsequenten Einsatz virtueller Techniken ist die Simulation der geforderten Produkteigenschaften und des Herstellungsprozesses möglich. Das Ergebnis einer so aufgebauten CAx-Prozesskette ist eine vollständige, durchgängig rechnerintegrierte Bauteilentwicklung. In diesem Beitrag wird ein derartiger Produktentstehungsprozess am Beispiel eines Kreiselpumpenlaufrades detailliert beschrieben. Durch die Schaffung eines Anwendungssystems für die Berechnung, Konstruktion und Fertigung von Pumpenlaufrädern lässt sich der Entwicklungsprozess enorm verkürzen. Gleichzeitig ist damit eine wesentliche Senkung der Entwicklungskosten für ein äußerst effektives und zuverlässiges Produkt verbunden. Virtual Modeling of Products with a Centrifugal Pump Impeller as an Example Shortening of the product life cycles means less time for the development of a technical product. There is no more time for an extensive testing program to obtain the desired product properties by investigation and modification of various prototypes. By careful application of virtual techniques the simulation of the required product properties and the production process is possible. The result of a CAx-System is a complete computer-integrated construction unit development. In this contribution the product developing process is described in detail for a centrifugal pump impeller. The creation of an application system for the computation, construction and manufacturing of pump impellers shortens the development process enormously. At the same time the development costs for an extremely effective and reliable product become substantially lower. [source] COHERENT ACCEPTABILITY MEASURES IN MULTIPERIOD MODELSMATHEMATICAL FINANCE, Issue 4 2005Berend Roorda The framework of coherent risk measures has been introduced by Artzner et al. (1999; Math. Finance 9, 203,228) in a single-period setting. Here, we investigate a similar framework in a multiperiod context. We add an axiom of dynamic consistency to the standard coherence axioms, and obtain a representation theorem in terms of collections of multiperiod probability measures that satisfy a certain product property. This theorem is similar to results obtained by Epstein and Schneider (2003; J. Econ. Theor. 113, 1,31) and Wang (2003; J. Econ. Theor. 108, 286,321) in a different axiomatic framework. We then apply our representation result to the pricing of derivatives in incomplete markets, extending results by Carr, Geman, and Madan (2001; J. Financial Econ. 32, 131,167) to the multiperiod case. We present recursive formulas for the computation of price bounds and corresponding optimal hedges. When no shortselling constraints are present, we obtain a recursive formula for price bounds in terms of martingale measures. [source] | |||||||||||||