Home About us Contact
|
Home About us Contact | ||
|
|
||
Chemical Engineering (chemical + engineering)
Selected AbstractsEmergence of New Mechanical Functionality in Materials via Size ReductionADVANCED FUNCTIONAL MATERIALS, Issue 18 2009Julia R. Greer Abstract Julia R. Greer received her S.B. in Chemical Engineering from the Massachusetts Institute of Technology (1997) and a Ph.D. in Materials Science from Stanford University, where she worked on the nanoscale plasticity of gold with W. D. Nix (2005). She also worked at Intel Corporation in Mask Operations (2000,03) and was a post-doctoral fellow at the Palo Alto Research Center (2005,07), where she worked on organic flexible electronics with R. A. Street. Greer is a recipient of TR-35, Technology Review's Top Young Innovator award (2008), a NSF CAREER Award (2007), a Gold Materials Research Society Graduate Student Award (2004), and an American Association of University Women Fellowship (2003). Julia joined Caltech's Materials Science department in 2007 where she is developing innovative experimental techniques to assess mechanical properties of nanometer-sized materials. One such approach involves the fabrication of nanopillars with different initial microstructures and diameters between 25,nm and 1,µm by using focused ion beam and electron-beam lithography microfabrication. The mechanical response of these pillars is subsequently measured in a custom-built in situ mechanical deformation instrument, SEMentor, comprising a scanning electron microscope and a nanoindenter. Read our interview with Prof. Greer on MaterialsViews.com [source] NMR Imaging in Chemical EngineeringMACROMOLECULAR MATERIALS & ENGINEERING, Issue 2 2008Peter Blümler [source] A lab-scale reaction calorimeter for olefin polymerizationTHE CANADIAN JOURNAL OF CHEMICAL ENGINEERING, Issue 5 2010Virginie F. Tisse A reaction calorimeter was built to follow slurry-phase polymerizations of ethylene using different types of supported catalysts. It was shown that heat flow calorimetry, employing a high-gain observer for the evaluation of the initial conditions was an extremely useful tool for the measurement of on-line reaction rates, and a study of the influence of different parameters such as the stirring rate or solid content in real time. It was shown that if one uses solid contents under 30% (volume) then it is not necessary to account for the influence of this quantity on the overall heat transfer coefficient. Un calorimètre de réaction a été construit pour le suivi des polymérisations des phases de suspension de l'éthylène utilisant différents types de catalyseurs adaptés. Il a été démontré que la calorimétrie du flux thermique, utilisant un observateur à gain élevé pour l'évaluation des conditions initiales s'est avérée un outil extrêmement utile pour mesurer les taux de réaction en ligne, et pour l'étude en temps réel de l'influence de différents paramètres tels que la vitesse d'agitation ou le contenu en matière solide. Il a été démontré que si l'on utilise la matière solide en dessous de 30% (en termes de volume), alors il n'est pas nécessaire de prendre en compte l'influence de cette quantité sur le coefficient global de transfert thermique. Can. J. Chem. Eng. © 2010 Canadian Society for Chemical Engineering [source] Chemical Engineering: Trends and Developments.THE CANADIAN JOURNAL OF CHEMICAL ENGINEERING, Issue 5 2006No abstract is available for this article. [source] Hydrodynamics, Mass and Heat Transfer in Chemical Engineering: by A.D. Polyanin, A.M. Kutopov, A.V. Vyazmin and D.A. Kazenin 2002, Taylor and Francis, London, U.K. + 386 pages Price US $125; ISBN 0-415-27237-8THE CANADIAN JOURNAL OF CHEMICAL ENGINEERING, Issue 1 2004R. P. Chhabra No abstract is available for this article. [source] Problem-Based Learning Biotechnology Courses in Chemical EngineeringBIOTECHNOLOGY PROGRESS, Issue 1 2006Charles E. Glatz We have developed a series of upper undergraduate/graduate lecture and laboratory courses on biotechnological topics to supplement existing biochemical engineering, bioseparations, and biomedical engineering lecture courses. The laboratory courses are based on problem-based learning techniques, featuring two- and three-person teams, journaling, and performance rubrics for guidance and assessment. Participants initially have found them to be difficult, since they had little experience with problem-based learning. To increase enrollment, we are combining the laboratory courses into 2-credit groupings and allowing students to substitute one of them for the second of our 2-credit chemical engineering unit operations laboratory courses. [source] Book Review: Collaborative and Distributed Chemical Engineering.CHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 11 2009By M. Nagel, W. Marquardt. No abstract is available for this article. [source] Subject Index Chemical Engineering & Technolgy , CET 2004CHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 12 2004Article first published online: 7 DEC 200 First page of article [source] Chemical engineering and virology: Challenges and opportunities at the interfaceAICHE JOURNAL, Issue 9 2007John Yin First page of article [source] Scaleup in chemical Engineering.AICHE JOURNAL, Issue 4 2003$99.9, 219 pp., By Marko Zlokarnik, Federal Republic of Germany, Weinheim, wiley-VCH Verlag GmbH No abstract is available for this article. [source] Chemically Derived Graphene Oxide: Towards Large-Area Thin-Film Electronics and OptoelectronicsADVANCED MATERIALS, Issue 22 2010Goki Eda Abstract Chemically derived graphene oxide (GO) possesses a unique set of properties arising from oxygen functional groups that are introduced during chemical exfoliation of graphite. Large-area thin-film deposition of GO, enabled by its solubility in a variety of solvents, offers a route towards GO-based thin-film electronics and optoelectronics. The electrical and optical properties of GO are strongly dependent on its chemical and atomic structure and are tunable over a wide range via chemical engineering. In this Review, the fundamental structure and properties of GO-based thin films are discussed in relation to their potential applications in electronics and optoelectronics. [source] Generalized lattice-BGK concept for thermal and chemically reacting flows at low Mach numbersINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, Issue 4 2006D. Hänel Abstract The lattice-BGK method has been extended by introducing additional, free parameters in the original formulation of the lattice-BGK methods. The relationship between these parameters and the macroscopic moment equations is analysed by Taylor series and Chapman,Enskog expansion. The parameters are determined from the macroscopic moment equations by comparisons with the governing equations to be modelled. Extensions are presented for the Navier,Stokes equations at low Mach numbers in Cartesian or axisymmetric coordinates with constant or variable density, for scalar convection,diffusion equations and for equations of Poisson type. The generalized lattice-BGK concept is demonstrated by two applications of chemical engineering. These are the computation of chemically reacting flow through an axisymmetric reactor and of the transport and deposition of particles to filters under the action of different forces. Copyright © 2006 John Wiley & Sons, Ltd. [source] Membrane engineering for process intensification: a perspectiveJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 3 2007Enrico Drioli Abstract Pushed by the increasing demand for materials, energy and products, chemical engineering today faces a crucial challenge: to support a sustainable industrial growth. One possible solution is process intensification (PI), the innovative design strategy aiming to improve manufacturing and processing by decreasing the equipment size/productivity ratio, energy consumption and waste production using innovative technical solutions. Membrane processes meet the requirements of PI because they have potential to replace conventional energy-intensive techniques, to accomplish the selective and efficient transport of specific components, and to improve the performance of reactive processes. Here, we identify the most interesting aspects of membrane engineering in some strategic industrial sectors. The opportunity to integrate conventional membrane units with innovative systems in order to exploit the potential advantages coming from their synergic applications is also emphasized. Copyright © 2007 Society of Chemical Industry [source] The rise and realization of molecular chemical engineering,AICHE JOURNAL, Issue 7 2009Mark E. Davis First page of article [source] Computation of an extractive distillation column with affine arithmeticAICHE JOURNAL, Issue 7 2009Ali Baharev Abstract The need of reliably solving systems of nonlinear equations often arises in the everyday practice of chemical engineering. In general, standard methods cannot provide theoretical guarantee for convergence to a solution, cannot reliably find multiple solutions, and cannot prove nonexistence of solutions. Interval methods provide tools to overcome these problems, thus achieving reliability. To the authors' best knowledge, computation of distillation columns with interval methods have not yet been considered in the literature. This article presents significant enhancements compared with a previously published interval method of the authors. The proposed branch-and-prune algorithm is guaranteed to converge, and is fairly general at the same time. If no solution exists then this information is provided by the method as a result. Power of the suggested method is demonstrated by solving, with guaranteed convergence, even the MESH equations of a 22 stage extractive distillation column with a ternary mixture. © 2009 American Institute of Chemical Engineers AIChE J, 2009 [source] Process intensification aspects for steam methane reforming: An overviewAICHE JOURNAL, Issue 2 2009Shrikant A. Bhat Abstract Steam methane reforming (SMR) is the most widely used process in industry for the production of hydrogen, which is considered as the future generation energy carrier. Having been perceived as an important source of H2, there are abundant incentives for design and development of SMR processes mainly through the consideration of process intensification and multiscale modeling; two areas which are considered as the main focus of the future generation chemical engineering to meet the global energy challenges. This article presents a comprehensive overview of the process integration aspects for SMR, especially the potential for multiscale modeling in this area. The intensification for SMR is achieved by coupling with adsorption and membrane separation technologies, etc., and using the concept of multifunctional reactors and catalysts to overcome the mass transfer, heat transfer, and thermodynamic limitations. In this article, the focus of existing and future research on these emerging areas has been drawn. © 2009 American Institute of Chemical Engineers AIChE J, 2009 [source] Residence time distribution: An old concept in chemical engineering and a new application in polymer processingAICHE JOURNAL, Issue 1 2009Cai-Liang Zhang First page of article [source] Ecological engineering and sustainability: A new opportunity for chemical engineeringAICHE JOURNAL, Issue 12 2008Daniel B. Stouffer First page of article [source] Chemical product engineering: An emerging paradigm within chemical engineeringAICHE JOURNAL, Issue 6 2006R. Costa First page of article [source] Density functional theory for chemical engineering: From capillarity to soft materialsAICHE JOURNAL, Issue 3 2006Jianzhong Wu Abstract Understanding the microscopic structure and macroscopic properties of condensed matter from a molecular perspective is important for both traditional and modern chemical engineering. A cornerstone of such understanding is provided by statistical mechanics, which bridges the gap between molecular events and the structural and physiochemical properties of macro- and mesoscopic systems. With ever-increasing computer power, molecular simulations and ab initio quantum mechanics are promising to provide a nearly exact route to accomplishing the full potential of statistical mechanics. However, in light of their versatility for solving problems involving multiple length and timescales that are yet unreachable by direct simulations, phenomenological and semiempirical methods remain relevant for chemical engineering applications in the foreseeable future. Classical density functional theory offers a compromise: on the one hand, it is able to retain the theoretical rigor of statistical mechanics and, on the other hand, similar to a phenomenological method, it demands only modest computational cost for modeling the properties of uniform and inhomogeneous systems. Recent advances are summarized of classical density functional theory with emphasis on applications to quantitative modeling of the phase and interfacial behavior of condensed fluids and soft materials, including colloids, polymer solutions, nanocomposites, liquid crystals, and biological systems. Attention is also given to some potential applications of density functional theory to material fabrications and biomolecular engineering. © 2005 American Institute of Chemical Engineers AIChE J, 2006 [source] Will humans swim faster or slower in syrup?AICHE JOURNAL, Issue 11 2004Brian Gettelfinger Abstract Foreword The scientific and engineering principles that underlie chemical engineering can also be used to understand a wide variety of other phenomena, including in areas not thought of as being central to our profession. As such applications might be of interest to our readers, we will consider brief submissions for publication in this category as R&D notes. These submissions will undergo review, and novelty will be an important factor in reaching an editorial decision. The first such article, "Will Humans Swim Faster or Slower in Syrup?" by Brian Gettelfinger and associate editor Ed Cussler, appears in this issue. Stanley I. Sandler Editor [source] Origins and development of biomedical engineering within chemical engineeringAICHE JOURNAL, Issue 3 2004Nicholas A. Peppas Abstract Over the past 45 years, the field of biomedical engineering has found a welcome home in academic chemical engineering departments and in companies working with artificial organs, medical devices, and pharmaceutical formulations. The contributions of chemical engineers to the definition and the growth of the field have been important and at times seminal. The development and early contributions in the biomedical field with special emphasis on the contributions of chemical engineers is examined. © 2004 American Institute of Chemical Engineers AIChE J, 50: 536,546, 2004 [source] Mathematics in chemical engineering: A 50 year introspectionAICHE JOURNAL, Issue 1 2004Doraiswami Ramkrishna Abstract A review is made of the role of mathematics in the field of chemical engineering in the latter half of the twentieth century. The beginning of this era was marked by the concerted effort of a few to raise the mathematical consciousness of the profession to think fundamentally about processes. We have accomplished this review by providing a rough structure of the areas of mathematics, deliberating on how each area has matured through growing applications, to conclude that mathematics is the main medium to meditate not only about processes, but even about materials and products. As we are clearly entering another era where the domain of chemical engineering is expanding into new areas with a focus on discovery oriented high throughput technology, modeling and rapid computation must provide the guidelines for rational interpretation of multitudes of observations. © 2004 American Institute of Chemical Engineers AIChE J, 50: 7,23, 2004 [source] Molecular simulations in chemical engineering: Present and futureAICHE JOURNAL, Issue 12 2002Juan J. de Pablo First page of article [source] Lab-on-a-chip: Opportunities for chemical engineeringAICHE JOURNAL, Issue 8 2002Andrea W. Chow First page of article [source] Wavelet-based adaptive grid method for the resolution of nonlinear PDEsAICHE JOURNAL, Issue 4 2002Paulo Cruz Theoretical modeling of dynamic processes in chemical engineering often implies the numeric solution of one or more partial differential equations. The complexity of such problems is increased when the solutions exhibit sharp moving fronts. A new numerical method is established, based on interpolating wavelets, that dynamically adapts the collocation grid so that higher resolution is automatically attributed to domain regions where sharp features are present. The effectiveness of the method is demonstrated with some relevant examples in a chemical engineering context. [source] Multiscale modeling of hard materials: Challenges and opportunities for chemical engineeringAICHE JOURNAL, Issue 5 2000Dimitrios Maroudas First page of article [source] Polymer-Derived Ceramics: 40 Years of Research and Innovation in Advanced CeramicsJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 7 2010Paolo Colombo Preceramic polymers were proposed over 30 years ago as precursors for the fabrication of mainly Si-based advanced ceramics, generally denoted as polymer-derived ceramics (PDCs). The polymer to ceramic transformation process enabled significant technological breakthroughs in ceramic science and technology, such as the development of ceramic fibers, coatings, or ceramics stable at ultrahigh temperatures (up to 2000°C) with respect to decomposition, crystallization, phase separation, and creep. In recent years, several important advances have been achieved such as the discovery of a variety of functional properties associated with PDCs. Moreover, novel insights into their structure at the nanoscale level have contributed to the fundamental understanding of the various useful and unique features of PDCs related to their high chemical durability or high creep resistance or semiconducting behavior. From the processing point of view, preceramic polymers have been used as reactive binders to produce technical ceramics, they have been manipulated to allow for the formation of ordered pores in the meso-range, they have been tested for joining advanced ceramic components, and have been processed into bulk or macroporous components. Consequently, possible fields of applications of PDCs have been extended significantly by the recent research and development activities. Several key engineering fields suitable for application of PDCs include high-temperature-resistant materials (energy materials, automotive, aerospace, etc.), hard materials, chemical engineering (catalyst support, food- and biotechnology, etc.), or functional materials in electrical engineering as well as in micro/nanoelectronics. The science and technological development of PDCs are highly interdisciplinary, at the forefront of micro- and nanoscience and technology, with expertise provided by chemists, physicists, mineralogists, and materials scientists, and engineers. Moreover, several specialized industries have already commercialized components based on PDCs, and the production and availability of the precursors used has dramatically increased over the past few years. In this feature article, we highlight the following scientific issues related to advanced PDCs research: (1) General synthesis procedures to produce silicon-based preceramic polymers. (2) Special microstructural features of PDCs. (3) Unusual materials properties of PDCs, that are related to their unique nanosized microstructure that makes preceramic polymers of great and topical interest to researchers across a wide spectrum of disciplines. (4) Processing strategies to fabricate ceramic components from preceramic polymers. (5) Discussion and presentation of several examples of possible real-life applications that take advantage of the special characteristics of preceramic polymers. Note: In the past, a wide range of specialized international symposia have been devoted to PDCs, in particular organized by the American Ceramic Society, the European Materials Society, and the Materials Research Society. Most of the reviews available on PDCs are either not up to date or deal with only a subset of preceramic polymers and ceramics (e.g., silazanes to produce SiCN-based ceramics). Thus, this review is focused on a large number of novel data and developments, and contains materials from the literature but also from sources that are not widely available. [source] Crystallization of Silicate Magmas Deciphered Using Crystal Size DistributionsJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 3 2007Bruce D. Marsh The remoteness and inhospitable nature of natural silicate magma make it exceedingly difficult to study in its natural setting deep beneath volcanoes. Although laboratory experiments involving molten rock are routinely performed, it is the style and nature of crystallization under natural conditions that is important to understand. This is where the crystal size distributions (CSD) method becomes fundamentally valuable. Just as chemical thermodynamics offers a quantitative macroscopic means of investigating chemical processes that occur at the atomic level, crystal size distribution theory quantitatively relates the overall observed spectrum of crystal sizes to both the kinetics of crystallization and the physical processes affecting the population of crystals themselves. Petrography, which is the qualitative study of rock textures, is the oldest, most comprehensively developed, and perhaps most beautiful aspect of studying magmatic rocks. It is the ultimate link to the kinetics of crystallization and the integrated space,time history of evolution of every magma. CSD analysis offers a quantitative inroad to unlocking and quantifying the observed textures of magmatic rocks. Perhaps the most stunning feature of crystal-rich magmatic rocks is that the constituent crystal populations show smooth and often quasi-linear log-normal distributions of negative slope when plotted as population density against crystal size. These patterns are decipherable using CSD theory, and this method has proven uniquely valuable in deciphering the kinetics of crystallization of magma. The CSD method has been largely developed in chemical engineering by Randolph and Larson,1,2 among many others, for use in understanding industrial crystallization processes, and its introduction to natural magmatic systems began in 1988. The CSD approach is particularly valuable in its ease of application to complex systems. It is an aid to classical kinetic theory by being, in its purest form, free of any atomistic assumptions regarding crystal nucleation and growth. Yet the CSD method provides kinetic information valuable to understanding the connection between crystal nucleation and growth and the overall cooling and dynamics of magma. It offers a means of investigating crystallization in dynamic systems, involving both physical and chemical processes, independent of an exact kinetic theory. The CSD method applied to rocks shows a systematic and detailed history of crystal nucleation and growth that forms the foundation of a comprehensive and general model of magma solidification. [source] Parameter estimation for differential equations: a generalized smoothing approachJOURNAL OF THE ROYAL STATISTICAL SOCIETY: SERIES B (STATISTICAL METHODOLOGY), Issue 5 2007J. O. Ramsay Summary., We propose a new method for estimating parameters in models that are defined by a system of non-linear differential equations. Such equations represent changes in system outputs by linking the behaviour of derivatives of a process to the behaviour of the process itself. Current methods for estimating parameters in differential equations from noisy data are computationally intensive and often poorly suited to the realization of statistical objectives such as inference and interval estimation. The paper describes a new method that uses noisy measurements on a subset of variables to estimate the parameters defining a system of non-linear differential equations. The approach is based on a modification of data smoothing methods along with a generalization of profiled estimation. We derive estimates and confidence intervals, and show that these have low bias and good coverage properties respectively for data that are simulated from models in chemical engineering and neurobiology. The performance of the method is demonstrated by using real world data from chemistry and from the progress of the autoimmune disease lupus. [source] | ||||||||||||||||||||||