Chemical Engineering

Despite the remarkable thermochemical accuracy of Kohn–Sham density-functional theories with gradient corrections for exchange-correlation [see, for example, A. D. Becke, J. Chem. Phys. 96, 2155 (1992)], we believe that further improvements are unlikely unless exact-exchange information is considered. Arguments to support this view are presented, and a semiempirical exchange-correlation functional containing local-spin-density, gradient, and exact-exchange terms is tested on 56 atomization energies, 42 ionization potentials, 8 proton affinities, and 10 total atomic energies of first- and second-row systems. This functional performs significantly better than previous functionals with gradient corrections only, and fits experimental atomization energies with an impressively small average abs

Classical Monte Carlo simulations have been carried out for liquid water in the NPT ensemble at 25 °C and 1 atm using six of the simpler intermolecular potential functions for the water dimer: Bernal–Fowler (BF), SPC, ST2, TIPS2, TIP3P, and TIP4P. Comparisons are made with experimental thermodynamic and structural data including the recent neutron diffraction results of Thiessen and Narten. The computed densities and potential energies are in reasonable accord with experiment except for the original BF model, which yields an 18% overestimate of the density and poor structural results. The TIPS2 and TIP4P potentials yield oxygen–oxygen partial structure functions in good agreement with the neutron diffraction results. The accord with the experimental OH and HH partial structure functions is

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTUse of Dinitrosalicylic Acid Reagent for Determination of Reducing SugarG. L. MillerCite this: Anal. Chem. 1959, 31, 3, 426–428Publication Date (Print):March 1, 1959Publication History Published online1 May 2002Published inissue 1 March 1959https://pubs.acs.org/doi/10.1021/ac60147a030https://doi.org/10.1021/ac60147a030research-articleACS PublicationsRequest reuse permissionsArticle Views45222Altmetric-Citations19440LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calcula

VESTA is a three-dimensional visualization system for crystallographic studies and electronic state calculations. It has been upgraded to the latest version, VESTA 3 , implementing new features including drawing the external morphology of crystals; superimposing multiple structural models, volumetric data and crystal faces; calculation of electron and nuclear densities from structure parameters; calculation of Patterson functions from structure parameters or volumetric data; integration of electron and nuclear densities by Voronoi tessellation; visualization of isosurfaces with multiple levels; determination of the best plane for selected atoms; an extended bond-search algorithm to enable more sophisticated searches in complex molecules and cage-like structures; undo and redo in graphical

We present an analysis of the performances of a parameter free density functional model (PBE0) obtained combining the so called PBE generalized gradient functional with a predefined amount of exact exchange. The results obtained for structural, thermodynamic, kinetic and spectroscopic (magnetic, infrared and electronic) properties are satisfactory and not far from those delivered by the most reliable functionals including heavy parameterization. The way in which the functional is derived and the lack of empirical parameters fitted to specific properties make the PBE0 model a widely applicable method for both quantum chemistry and condensed matter physics.

1 Engine Types and Their Operations 2 Engine Design and Operating Parameters 3 Thermochemistry of Fuel-Air Mixtures 4 Properties of Working Fluids 5 Ideal Models of Engine Cycles 6 Gas Exchange Processes 7 SI Engine Fuel Metering and Manifold Phenomena 8 Charge Motion within the Cylinder 9 Combustion in Ignition Engines 10 Combustion in Compression Ignition Engines 11 Pollutant Formation and Control 12 Engine Heat Transfer 13 Engine Friction and Lubrication 14 Modeling Real Engine Flow and Combustion Processes 15 Engine Operating Characteristics Appendixes

The Nature of Viscoelastic Behavior. Illustrations of Viscoelastic Behavior of Polymeric Systems. Exact Interrelations among the Viscoelastic Functions. Approximate Interrelations among the Linear Viscoelastic Functions. Experimental Methods for Viscoelastic Liquids. Experimental Methods for Soft Viscoelastic Solids and Liquids of High Viscosity. Experimental Methods for Hard Viscoelastic Solids. Experimental Methods for Bulk Measurements. Dilute Solutions: Molecular Theory and Comparisons with Experiments. Molecular Theory for Undiluted Amorphous Polymers and Concentrated Solutions Networks and Entanglements. Dependence of Viscoelastic Behavior on Temperature and Pressure. The Transition Zone from Rubberlike to Glasslike Behavior. The Plateau and Terminal Zones in Uncross-Linked Polymers.

ADVERTISEMENT RETURN TO ISSUEPREVReviewNEXTRoom-Temperature Ionic Liquids: Solvents for Synthesis and Catalysis. 2Jason P. Hallett and Tom Welton*View Author Information Department of Chemistry, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom*E-mail: [email protected]Cite this: Chem. Rev. 2011, 111, 5, 3508–3576Publication Date (Web):April 6, 2011Publication History Received23 September 2010Published online6 April 2011Published inissue 11 May 2011https://pubs.acs.org/doi/10.1021/cr1003248https://doi.org/10.1021/cr1003248review-articleACS PublicationsCopyright © 2011 American Chemical SocietyRequest reuse permissionsArticle Views39839Altmetric-Citations3787LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads sin

An efficient method for the calculation of the interactions of a 2m factorial experiment was introduced by Yates and is widely known by his name.The generalization to 3m was given by Box et al. [1].Good [2] generalized these methods and gave elegant algorithms for which one class of applications is the calculation of Fourier series.In their full generality, Good's methods are applicable to certain problems in which one must multiply an JV-vector by an JV X N matrix which can be factored into m sparse matrices, where m is proportional to log JV.This results in a procedure requiring a number of operations proportional to JV log JV rather than JV2.These methods are applied here to the calculation of complex Fourier series.They are useful in situations where the number of data points is, or ca

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTRoom-Temperature Ionic Liquids. Solvents for Synthesis and CatalysisThomas WeltonView Author Information Department of Chemistry, Imperial College of Science Technology and Medicine, South Kensington, London SW7 2AY, U.K. Cite this: Chem. Rev. 1999, 99, 8, 2071–2084Publication Date (Web):July 7, 1999Publication History Received23 November 1998Revised13 April 1999Published online7 July 1999Published inissue 11 August 1999https://pubs.acs.org/doi/10.1021/cr980032thttps://doi.org/10.1021/cr980032tresearch-articleACS PublicationsCopyright © 1999 American Chemical SocietyRequest reuse permissionsArticle Views59145Altmetric-Citations11083LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2

The dispersion and absorption of a considerable number of liquid and dielectrics are represented by the empirical formula ε*−ε∞=(ε0−ε∞)/[1+(iωτ0)1−α]. In this equation, ε* is the complex dielectric constant, ε0 and ε∞ are the ``static'' and ``infinite frequency'' dielectric constants, ω=2π times the frequency, and τ0 is a generalized relaxation time. The parameter α can assume values between 0 and 1, the former value giving the result of Debye for polar dielectrics. The expression (1) requires that the locus of the dielectric constant in the complex plane be a circular arc with end points on the axis of reals and center below this axis. If a distribution of relaxation times is assumed to account for Eq. (1), it is possible to calculate the necessary distribution function by the method of F

Starting from the screening in conductors, an algorithm for the accurate calculation of dielectric screening effects in solvents is presented, which leads to rather simple explicit expressions for the screening energy and its analytic gradient with respect to the solute coordinates. Thus geometry optimization of a solute within a realistic dielectric continuum model becomes practicable for the first time. The algorithm is suited for molecular mechanics as well as for any molecular orbital algorithm. The implementation into MOPAC and some example applications are reported.

Abstract Low thermal conductivity is a primary limitation in the development of energy-efficient heat transfer fluids that are required in many industrial applications. In this paper we propose that an innovative new class of heat transfer fluids can be engineered by suspending metallic nanoparticles in conventional heat transfer fluids. The resulting “nanofluids” are expected to exhibit high thermal conductivities compared to those of currently used heat transfer fluids, and they represent the best hope for enhancement of heat transfer. The results of a theoretical study of the thermal conductivity of nanofluids with copper nanophase materials are presented, the potential benefits of the fluids are estimated, and it is shown that one of the benefits of nanofluids will be dramatic reductio

Introduction Static properties of polymers Brownian motion Dynamics of flexible polymers in dilute solution Many chain systems Dynamics of a polymer in a fixed network Molecular theory for the viscoelasticity of polymeric liquids Dilute solutions of rigid rodlike polymers Semidilute solutions of rigid rodlike polymers Concentrated solutions of rigid rodlike polymers Index.

Marcel Pourbaix’s monumental work Atlas of Electrochemical Equilibria in Aqueous Solutions remains the definitive reference for understanding corrosion and passivation in metallic systems. Despite being nearly six decades old, it remains one of the most respected and enduring references in corrosion science and is still cited in AMPP, ISO, and ASTM standards. This title is the seminal work on the thermodynamic foundations of corrosion and metal stability in aqueous environments. It introduced the now-iconic Pourbaix diagrams—potential–pH (E–pH) diagrams—that map out the regions of immunity, passivation, and corrosion for metals and alloys. These diagrams remain indispensable for understanding and predicting corrosion behavior in systems ranging from industrial water treatment and nuclear p

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAb initio molecular orbital theoryWarren J. HehreCite this: Acc. Chem. Res. 1976, 9, 11, 399–406Publication Date (Print):November 1, 1976Publication History Published online1 May 2002Published inissue 1 November 1976https://pubs.acs.org/doi/10.1021/ar50107a003https://doi.org/10.1021/ar50107a003research-articleACS PublicationsRequest reuse permissionsArticle Views3547Altmetric-Citations280LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated

This book gives a comprehensive and up-to-date treatment of the theory of "simple" liquids. The new second edition has been rearranged and considerably expanded to give a balanced account both of basic theory and of the advances of the past decade. It presents the main ideas of modern liquid state theory in a way that is both pedagogical and self-contained. The book should be accessible to graduate students and research workers, both experimentalists and theorists, who have a good background in elementary mechanics.Key Features* Compares theoretical deductions with experimental r

Although density functional theory is widely used in the computational chemistry community, the most popular density functional, B3LYP, has some serious shortcomings: (i) it is better for main-group chemistry than for transition metals; (ii) it systematically underestimates reaction barrier heights; (iii) it is inaccurate for interactions dominated by medium-range correlation energy, such as van der Waals attraction, aromatic-aromatic stacking, and alkane isomerization energies. We have developed a variety of databases for testing and designing new density functionals. We used these data to design new density functionals, called M06-class (and, earlier, M05-class) functionals, for which we enforced some fundamental exact constraints such as the uniform-electron-gas limit and the absence of

ADVERTISEMENT RETURN TO ISSUEPREVReviewNEXTDeep Eutectic Solvents (DESs) and Their ApplicationsEmma L. Smith*†‡, Andrew P. Abbott‡, and Karl S. Ryder‡View Author Information† Department of Chemistry, School of Science and Technology, Nottingham Trent University, Nottingham NG11 8NS, United Kingdom‡ Department of Chemistry, University of Leicester, Leicester LE1 7RH, United Kingdom*E-mail: [email protected]Cite this: Chem. Rev. 2014, 114, 21, 11060–11082Publication Date (Web):October 10, 2014Publication History Received18 April 2012Published online10 October 2014Published inissue 12 November 2014https://doi.org/10.1021/cr300162pCopyright © 2014 American Chemical SocietyRIGHTS & PERMISSIONSACS AuthorChoiceArticle Views194896Altmetric-Citations3706LEARN ABOUT THESE METRICSArticle Views are th

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSignaling Recognition Events with Fluorescent Sensors and SwitchesA. Prasanna de Silva, H. Q. Nimal Gunaratne, Thorfinnur Gunnlaugsson, Allen J. M. Huxley, Colin P. McCoy, Jude T. Rademacher, and Terence E. RiceView Author Information School of Chemistry, Queen's University, Belfast BT9 5AG, Northern Ireland Cite this: Chem. Rev. 1997, 97, 5, 1515–1566Publication Date (Web):August 5, 1997Publication History Received6 December 1996Revised12 March 1997Published online5 August 1997Published inissue 1 August 1997https://pubs.acs.org/doi/10.1021/cr960386phttps://doi.org/10.1021/cr960386presearch-articleACS PublicationsCopyright © 1997 American Chemical SocietyRequest reuse permissionsArticle Views36299Altmetric-Citations6309LEARN ABOUT THESE METRICSAr