C. N. Satyadev, K. Jayaraman, C. Petty, N.S. Losure
{"title":"Stability of Polymerizing Liquid Flow in Porous Media","authors":"C. N. Satyadev, K. Jayaraman, C. Petty, N.S. Losure","doi":"10.1080/10543414.2000.10744547","DOIUrl":"https://doi.org/10.1080/10543414.2000.10744547","url":null,"abstract":"ABSTRACT This paper examines the flow stability of a polymerizing liquid in an anisotropic porous medium. The polymerization reaction leads to an increasing viscosity along the flow direction, particularly behind the advancing resin/air front, and may cause the miscible displacement process to become unstable and uneven. A linearized stability analysis of the flow within the filled region behind the liquid / air interface has been conducted. This reveals that under a moderate adverse viscosity gradient, the polymerization reaction has the potential for stabilizing the flow process by damping out disturbances of wavelengths above a critical size. Guidelines are provided for adjusting the composition of the reacting liquid and the anisotropic medium permeability to stabilize the flow process.","PeriodicalId":124648,"journal":{"name":"Polymer Reaction Engineering","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127522510","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Control of Bulk ε-Caprolactone Polymerization in a Twin Screw Extruder","authors":"J. Gimenez, M. Boudris, P. Cassagnau, A. Michel","doi":"10.1080/10543414.2000.10744545","DOIUrl":"https://doi.org/10.1080/10543414.2000.10744545","url":null,"abstract":"ABSTRACT The bulk polymerisation of ε-caprolactone initiated by tetrapropoxy titanium was investigated in a co-rotating twin screw extruder. The process dynamic modelling, based on pressure measurements, was achieved via a combination of rheological modelling coupled with residence time distribution modelling. The former was deduced from equations which characterise the flow inside the die and the rheological behaviour of the melt polymer. The latter was determined with an in-line Ultra-Violet fluorescence method. An approach for the process regulation by the way of internal model control has given good results in simulation. However, the large response time to the control, relative to the process dynamic, constitutes a limiting factor for experimental control of the process.","PeriodicalId":124648,"journal":{"name":"Polymer Reaction Engineering","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127835819","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"On-Line Monitoring of Emulsion Copolymerisations Using Hardware Sensors and Calorimetry","authors":"P. Guinot, N. Othman, G. Févotte, T. McKenna","doi":"10.1080/10543414.2000.10744544","DOIUrl":"https://doi.org/10.1080/10543414.2000.10744544","url":null,"abstract":"ABSTRACT We have used a simplified model of emulsion polymerisation, along with an adaptive calorimetric approach and a set of non-linear state estimators to monitor the individual monomer conversions in a pilot scale polymerisation reactor for the production of methyl methacrylate/butyl acrylate/carboxylic acid polymers. The usefulness of reaction calorimetry for the monitoring of such systems is demonstrated. It is also shown that non-linear, high gain estimators can be used to monitor such systems even if they are based on simplified models that ignore polymerisation of the two principal monomers in the aqueous phase, and of the carboxylic acid. The advantages and disadvantages of several different types of on-line sensors for use in industrial situations are also reviewed.","PeriodicalId":124648,"journal":{"name":"Polymer Reaction Engineering","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131502325","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Guest Editor's Foreword","authors":"Leslee EdD Battle","doi":"10.1080/10543414.2000.10744543","DOIUrl":"https://doi.org/10.1080/10543414.2000.10744543","url":null,"abstract":"Battle asserts that the COVID-19 pandemic has advanced our understanding of the scope and nature of health disparities and the inequities of the healthcare system. The time for change is now. Providers of healthcare services must remain vigilant to the needs of the underserved, be aware of their own implicit biases, and take concerted efforts to break the cycle of disparate healthcare. Health science programs must be intentional in the recruitment of underrepresented minorities in their programs and incorporating core concepts related to health equity in the classroom and practicum experiences. The programmatic change can be accomplished using a variety of innovative methodologies, such as tailoring case studies and pathways to address inequities, mentoring in practicum settings, involving students in research exploring healthcare disparities and devising ways to promote patient centered care that results in better outcomes. Even ensuring students are linguistically correct when caring for patients can go a long way toward creating positive change.","PeriodicalId":124648,"journal":{"name":"Polymer Reaction Engineering","volume":"60 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121755672","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Observations on HDPE Characterization with a Microcalorimeter as a Complementary Tool to TREF and CRYSTAF","authors":"L. J. Britto, J. Soares, A. Penlidis","doi":"10.1080/10543414.2000.10744546","DOIUrl":"https://doi.org/10.1080/10543414.2000.10744546","url":null,"abstract":"ABSTRACT Calorimetric measurements of high-density polyethylene (HDPE) crystallization and dissolution in dilute solution were performed in a microcalorimeter. The results were similar to those obtained from fractionation techniques such as TREF, CITREF and CRYSTAF. This suggests that a microcalorimeter can be used to investigate optimal experimental conditions for those techniques and as an alternative analysis technique for determining polyolefin microstructure.","PeriodicalId":124648,"journal":{"name":"Polymer Reaction Engineering","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130698490","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Guest Editor's Foreword","authors":"James W. Watts","doi":"10.1080/10543414.2000.10744536","DOIUrl":"https://doi.org/10.1080/10543414.2000.10744536","url":null,"abstract":"In literature, the concept of intellectual capital is present since 1969, when the American economist James K. Galbraith introduced it in theory and practice. He envisioned it not as a fixed form of capital but as something intangible, dynamic, as a process of knowledge application, and as a tool for achieving the companies’ objectives. The components of intellectual capital include people and their skills, as well as other aspects of knowledge in the broadest sense of its understanding in the internal and external structure of the company. Intellectual capital management has a significant impact on both shortand long-term policies of the company as well as synchronous operation of all its components. However, the concept of intellectual capital can be also understood wider, within the economy and society. As a component of the intellectual capital, social capital stresses the importance of membership in social networks and management of values, norms, understanding and trust to promote social and civic participation and to enhance the quality of life. On the other hand, human capital, which was introduced in the economic theory in 1961 by American Nobel laureate Theodore W. Schultz, emphasizes the issue of education and health systems, lifelong learning, and cause-effect links with company profitability, labour productivity and economic performance of countries. The concept of intellectual capital is closely linked to sustainability, which should be understood as a phenomenon that increases the quality of human life while living within the carrying capacity of supporting ecosystems. Deriving from that, intellectual capital is also closely linked with sustainable development, which is the kind of development that meets the needs of the present without compromising the ability of future generations to meet their own needs. Only knowledge and the appropriate use of knowledge, which by definition is intellectual capital, can provide both – quality of life within the capabilities of current ecosystems as well as life that does not jeopardize the life of future generations. Papers in this special issue of the journal are dealing with a wide range of topics, related to sustainability and sustainable development, which are founded on the concept of intellectual capital. The paper ‘Determinants of Willingness to Pay for an Urban Green Area’ reveals the importance of the systematic raising of awareness of the importance of maintaining sustainable green urban areas for quality of life in cities. The paper ‘Supply Chains","PeriodicalId":124648,"journal":{"name":"Polymer Reaction Engineering","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125199727","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T. McKenna, S. Othman, G. Févotte, A. Santos, H. Hammouri
{"title":"An Integrated Approach to Polymer Reaction Engineering: A Review of Calorimetry and State Estimation","authors":"T. McKenna, S. Othman, G. Févotte, A. Santos, H. Hammouri","doi":"10.1080/10543414.2000.10744537","DOIUrl":"https://doi.org/10.1080/10543414.2000.10744537","url":null,"abstract":"ABSTRACT In order to completely master a polymerisation process, it is necessary to take a pluri-disciplinary approach that incorporates the use of kinetic and polymer property models (e.g. of Rp, the rate of polymerisation and of copolymer composition distribution, CCD), hardware and software sensors, non-linear observers for the data interpretation, and easily tuneable, robust controllers for the optimal and safe operation of reactors that produce polymer of a pre-specified quality. An overview of the results obtained in this area show that such an approach allows not only to follow and control production rates and the evolution of the CCD, but to obtain other useful process information on the evolution of such properties as the number of particles per litre of emulsion (Np) and the number of radicals per particle () in emulsion polymerisation, or the overall termination rate constant in solution reactions. It is also shown that this method can be used not only for reactor control, but also for fault detection and process optimisation.","PeriodicalId":124648,"journal":{"name":"Polymer Reaction Engineering","volume":"92 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117172371","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Monitoring Latex Reactors by Ultrasonics","authors":"G. Storti, A. Hipp, M. Morbidelli","doi":"10.1080/10543414.2000.10744539","DOIUrl":"https://doi.org/10.1080/10543414.2000.10744539","url":null,"abstract":"ABSTRACT The application of ultrasonics to emulsion polymerization reactors is discussed. First, monitoring of conversion in reacting systems by measuring sound velocity at a single relatively low frequency is presented. A simplified modeling approach is adopted, relating the sound speed in the multiphase system to effective values of compressibility and density. The capabilities of such sensors are shown for the emulsion copolymerization of styrene and butylacrylate. Next, the application of sound attenuation measurements to particle sizing is examined. A comprehensive literature model is used to extract the particle size distribution from the measured attenuation spectra for two nonreacting latexes, polyvinylchloride and polytetrafluoroethylene. The problem of model parameter evaluation is addressed, and the results of a parameter sensitivity analysis are briefly discussed. Difficulties related to the presence of ionic emulsifier and large particle concentrations are highlighted.","PeriodicalId":124648,"journal":{"name":"Polymer Reaction Engineering","volume":"108 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133306015","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号
