Equilibrium Critical Phenomena in Fluids and Mixtures
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Van Der Waals Force & Hydrophobic Effect
International Journal of Advanced Computer Technology (IJACT) ISSN:2319-7900 Van der Waals Force & Hydrophobic Effect Park, Ho-Min, Grade 12, Ewell Castle School , UK. [Abstract] polar atoms interacting with each other, Deybe Force Van der Waals forces are electrostatic forces. They Effect which caused between a molecule with is polar, operate not only between polar molecules but also and one that is not, and London Dispersal Effect that acts between electrically neutral atoms and molecules. This is between two non-polar molecules/atoms[3]. Because the because the movement of electrons in the outer shell of electrons around each molecule/atom repel each other, it the atoms temporarily leads to charge displacements – creates a redistribution of charge, inducing an and to so-called polarization. Charged areas with instantaneous dipole moment[3]. Dispersion forces are different signs are then attracted to one another – and caused by fluctuations in the electron distribution within therefore ensure an attraction between two atoms, even if molecules or atoms. Since all atoms and molecules have these are electrically neutral overall. The van der Waals electrons, they all have dispersion forces. The electrons force is an electromagnetic interaction between in an atom or molecule may, at any one instant, be correlated fluctuating charges on two electrically neutral unevenly distributed[4]. The purpose of this study is to surfaces. As the surfaces approach more closely, the explore mechanisms of van der Waals forces forces and force increases as fluctuations of shorter and shorter to identify the potential on the scientific field. length scale come into play, but ultimately the force will saturate when the surfaces are so close that the even shortest wavelength charge fluctuations are included. -
Synchronous Fluorescence Spectroscopic Study Of
Spectrochimica Acta Part A 79 (2011) 1034–1041 Contents lists available at ScienceDirect Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy jou rnal homepage: www.elsevier.com/locate/saa Synchronous fluorescence spectroscopic study of solvatochromic curcumin dye ∗ Digambara Patra , Christelle Barakat Department of Chemistry, Faculty of Arts and Sciences, American University of Beirut, P.O. Box 11-0236, Riad El Solh, Beirut 1107-2020, Lebanon a r t i c l e i n f o a b s t r a c t Article history: Curcumin, the main yellow bioactive component of turmeric, has recently acquired attention by chemists Received 1 July 2010 due its wide range of potential biological applications as an antioxidant, an anti-inflammatory, and an Accepted 13 April 2011 anti-carcinogenic agent. This molecule fluoresces weakly and poorly soluble in water. In this detailed study of curcumin in thirteen different solvents, both the absorption and fluorescence spectra of curcumin Keywords: was found to be broad, however, a narrower and simple synchronous fluorescence spectrum of curcumin Curcumin was obtained at = 10–20 nm. Lippert–Mataga plot of curcumin in different solvents illustrated two Solvent polarity E sets of linearity which is consistent with the plot of Stokes’ shift vs. the 30. When Stokes’s shift in SFS T wavenumber scale was replaced by synchronous fluorescence maximum in nanometer scale, the solvent max E polarity dependency measured by SFS vs. Lippert–Mataga plot or T30 values offered similar trends as max measured via Stokes’ shift for protic and aprotic solvents for curcumin. Better linear correlation of SFS vs. -
Surface Tension Study of Concentration Dependent Cluster Breaking in Acetone-Alcohol Systems
www.sciencevision.org Sci Vis 12 (3), 102-105 July-September 2012 Original Research ISSN (print) 0975-6175 ISSN (online) 2229-6026 Surface tension study of concentration dependent cluster breaking in acetone-alcohol systems Jonathan Lalnunsiama* and V. Madhurima Department of Physics, Mizoram University, Aizawl 796 004, India Received 19 April 2012 | Revised 10 May 2012 | Accepted 13 August 2012 ABSTRACT Alcohols are well-known for the formation of clusters due to hydrogen bonds. When a second mo- lecular species such as acetone is added to an alcohol system, the hydrogen bonds are broken lead- ing to a destruction of the molecular clusters. In this paper we report the findings of surface ten- sion study over the entire concentration region of acetone and six alcohol systems over the entire concentration range. The alcohols chosen were methanol, ethanol, isopropanol, butanol, hexanol and octanol. Surface tension was measured using the pendent drop method. Our study showed a specific molecular interaction near the 1:1 concentration of lower alcohols and acetone whereas the higher alcohols did not exhibit the same. Key words: Surface tension; hydrogen bond; alcohols; acetone. INTRODUCTION vent effects4 but such effects are important and hence there are many studies of hydrogen Alcohols are marked by their ability to bonds in solvents.5 Dielectric and calorimetric form hydrogen bonded clusters.1,2 The addi- studies of clusters in alcohols in carbon-tertra- tion of a second molecular species, whether chloride were attributed to homogeneous as- hydrogen-bonded or not, will change the in- sociations of the alcohol.6 For methanol in p- termolecular interactions in the alcohol sys- dioxane the chain-like clusters were seen to tem, especially by breaking of the hydrogen- form the networks and not cyclic structures.7 bonded clusters. -
Chapter 6 - Engineering Equations of State II
Introductory Chemical Engineering Thermodynamics By J.R. Elliott and C.T. Lira Chapter 6 - Engineering Equations of State II. Generalized Fluid Properties The principle of two-parameter corresponding states 50 50 40 40 30 30 T=705K 20 20 ρ T=286K L 10 10 T=470 T=191K T=329K 0 0 0 0.1 0.2 0.3 0.4 0 0.1 0.2 0.3 0.4 0.5 -10 T=133K -10 ρV Density (g/cc) Density (g/cc) VdW Pressure (bars) in Methane VdW Pressure (bars) in Pentane Critical Definitions: Tc - critical temperature - the temperature above which no liquid can exist. Pc - critical pressure - the pressure above which no vapor can exist. ω - acentric factor - a third parameter which helps to specify the vapor pressure curve which, in turn, affects the rest of the thermodynamic variables. ∂ ∂ 2 P = P = 0 and 0 at Tc and Pc Note: at the critical point, ∂ρ ∂ρ 2 T T Chapter 6 - Engineering Equations of State Slide 1 II. Generalized Fluid Properties The van der Waals (1873) Equation Of State (vdW-EOS) Based on some semi-empirical reasoning about the ways that temperature and density affect the pressure, van der Waals (1873) developed the equation below, which he considered to be fairly crude. We will discuss the reasoning at the end of the chapter, but it is useful to see what the equations are and how we use them before deriving the details. The vdW-EOS is: bρ aρ 1 aρ Z =+1 −= − ()1− bρ RT()1− bρ RT van der Waals’ trick for characterizing the difference between subcritical and supercritical fluids was to recognize that, at the critical point, ∂P ∂ 2 P = 0 and = 0 at T , P ∂ρ ∂ρ 2 c c T T Since there are only two “undetermined parameters” in his EOS (a and b), he has reduced the problem to one of two equations and two unknowns. -
On the Van Der Waals Gas, Contact Geometry and the Toda Chain
entropy Article On the van der Waals Gas, Contact Geometry and the Toda Chain Diego Alarcón, P. Fernández de Córdoba ID , J. M. Isidro * ID and Carlos Orea Instituto Universitario de Matemática Pura y Aplicada, Universidad Politécnica de Valencia, 46022 Valencia, Spain; [email protected] (D.A.); [email protected] (P.F.d.C.); [email protected] (C.O.) * Correspondence: [email protected] Received: 7 June 2018; Accepted: 16 July 2018; Published: 26 July 2018 Abstract: A Toda–chain symmetry is shown to underlie the van der Waals gas and its close cousin, the ideal gas. Links to contact geometry are explored. Keywords: van der Waals gas; contact geometry; Toda chain 1. Introduction The contact geometry of the classical van der Waals gas [1] is described geometrically using a five-dimensional contact manifold M [2] that can be endowed with the local coordinates U (internal energy), S (entropy), V (volume), T (temperature) and p (pressure). This description corresponds to a choice of the fundamental equation, in the energy representation, in which U depends on the two extensive variables S and V. One defines the corresponding momenta T = ¶U/¶S and −p = ¶U/¶V. Then, the standard contact form on M reads [3,4] a = dU + TdS − pdV. (1) One can introduce Poisson brackets on the four-dimensional Poisson manifold P (a submanifold of M) spanned by the coordinates S, V and their conjugate variables T, −p, the nonvanishing brackets being fS, Tg = 1, fV, −pg = 1. (2) Given now an equation of state f (p, T,...) = 0, (3) one can make the replacements T = ¶U/¶S, −p = ¶U/¶V in order to obtain ¶U ¶U f − , ,.. -
Material Safety Data Sheet Ethanol SDA1, Anhydrous MSDS# 88067 Section 1
Material Safety Data Sheet Ethanol SDA1, Anhydrous MSDS# 88067 Section 1 - Chemical Product and Company Identification MSDS Name: Ethanol SDA1, Anhydrous Catalog Numbers: A405-20, A405P-4 Synonyms: Ethyl alcohol, denatured; Grain alcohol, denatured; Ethyl hydroxide, denatured. Fisher Scientific Company Identification: One Reagent Lane Fair Lawn, NJ 07410 For information in the US, call: 201-796-7100 Emergency Number US: 201-796-7100 CHEMTREC Phone Number, US: 800-424-9300 Section 2 - Composition, Information on Ingredients ---------------------------------------- Risk Phrases: 11 CAS#: 64-17-5 Chemical Name: Ethyl alcohol %: 92-93 EINECS#: 200-578-6 Hazard Symbols: F ---------------------------------------- ---------------------------------------- Risk Phrases: 11 23/24/25 39/23/24/25 CAS#: 67-56-1 Chemical Name: Methyl alcohol %: 3.7 EINECS#: 200-659-6 Hazard Symbols: F T ---------------------------------------- ---------------------------------------- Risk Phrases: CAS#: 108-10-1 Chemical Name: Methyl iso-butyl ketone %: 1.0-2.0 EINECS#: 203-550-1 Hazard Symbols: ---------------------------------------- ---------------------------------------- Risk Phrases: 11 20 CAS#: 108-88-3 Chemical Name: Toluene %: 0.07 EINECS#: 203-625-9 Hazard Symbols: F XN ---------------------------------------- ---------------------------------------- Risk Phrases: 11 36 66 67 CAS#: 141-78-6 Chemical Name: Ethyl acetate %: <1.0 EINECS#: 205-500-4 Hazard Symbols: F XI ---------------------------------------- Text for R-phrases: see Section 16 Hazard Symbols: XN F Risk Phrases: 11 20/21/22 68/20/21/22 Section 3 - Hazards Identification EMERGENCY OVERVIEW Warning! Flammable liquid and vapor. Causes respiratory tract irritation. May cause central nervous system depression. Causes severe eye irritation. This substance has caused adverse reproductive and fetal effects in humans. Causes moderate skin irritation. May cause liver, kidney and heart damage. Target Organs: Kidneys, heart, central nervous system, liver, eyes, optic nerve. -
International Centre for Theoretical Physics
REFi IC/90/116 INTERNATIONAL CENTRE FOR THEORETICAL PHYSICS FIXED SCALE TRANSFORMATION FOR ISING AND POTTS CLUSTERS A. Erzan and L. Pietronero INTERNATIONAL ATOMIC ENERGY AGENCY UNITED NATIONS EDUCATIONAL, SCIENTIFIC AND CULTURAL ORGANIZATION 1990 MIRAMARE- TRIESTE IC/90/116 International Atomic Energy Agency and United Nations Educational Scientific and Cultural Organization INTERNATIONAL CENTRE FOR THEORETICAL PHYSICS FIXED SCALE TRANSFORMATION FOR ISING AND POTTS CLUSTERS A. Erzan International Centre for Theoretical Physics, Trieste, Italy and L. Pietronero Dipartimento di Fisica, Universita di Roma, Piazzale Aldo Moro, 00185 Roma, Italy. ABSTRACT The fractal dimension of Ising and Potts clusters are determined via the Fixed Scale Trans- formation approach, which exploits both the self-similarity and the dynamical invariance of these systems at criticality. The results are easily extended to droplets. A discussion of inter-relations be- tween the present approach and renormalization group methods as well as Glauber—type dynamics is provided. MIRAMARE - TRIESTE May 1990 To be submitted for publication. T 1. INTRODUCTION The Fixed Scale Transformation, a novel technique introduced 1)i2) for computing the fractal dimension of Laplacian growth clusters, is applied here to the equilibrium problem of Ising clusters at criticality, in two dimensions. The method yields veiy good quantitative agreement with the known exact results. The same method has also recendy been applied to the problem of percolation clusters 3* and to invasion percolation 4), also with very good results. The fractal dimension D of the Ising clusters, i.e., the connected clusters of sites with identical spins, has been a controversial issue for a long time ^ (see extensive references in Refs.5 and 6). -
4. Industrial Processes and Product
4. Industrial Processes and Product Use The Industrial Processes and Product Use (IPPU) chapter includes greenhouse gas emissions occurring from industrial processes and from the use of greenhouse gases in products. The industrial processes and product use categories included in this chapter are presented in Figure 4-1. Greenhouse gas emissions from industrial processes can occur in two different ways. First, they may be generated and emitted as the byproducts of various non-energy- related industrial activities. Second, they may be emitted due to their use in manufacturing processes or by end- consumers. In the case of byproduct emissions, the emissions are generated by an industrial process itself, and are not directly a result of energy consumed during the process. For example, raw materials can be chemically or physically transformed from one state to another. This transformation can result in the release of greenhouse gases such as carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and fluorinated greenhouse gases (e.g., HFC-23). The greenhouse gas byproduct generating processes included in this chapter include iron and steel production and metallurgical coke production, cement production, lime production, other process uses of carbonates (e.g., flux stone, flue gas desulfurization, and glass manufacturing), ammonia production and urea consumption, petrochemical production, aluminum production, HCFC-22 production, soda ash production and use, titanium dioxide production, ferroalloy production, glass production, zinc production, phosphoric acid production, lead production, silicon carbide production and consumption, nitric acid production, adipic acid production, and caprolactam production. Greenhouse gases that are used in manufacturing processes or by end-consumers include man-made compounds such as hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), sulfur hexafluoride (SF6), and nitrogen trifluoride (NF3). -
Rnase Refolding • General Features of Globular Proteins • Interior Packing
Lecture Notes - 3 7.24/7.88J/5.48J The Protein Folding and Human Disease • Reprise RNase refolding • General Features of Globular proteins • Interior Packing Rnase Refolding We can cartoon the experiments: Assume that reduced form is unfolded and populates an ensemble of unfolded states in 8M urea: [Unfolded] [Intermediate] [Native] [U] Rapidly exchanging statistical ensemble of random coils [I] ??? [N] Native fold, $ S-S bonds, 1 out of 105 possible sets of S-S bonds [Aggregated] Non-native (no enzymatic activity), non-native (scrambled) disulfide bonds. At the end of the reaction we have native state Soluble inactive – misfolded or perhaps small oligomers Precipitated: Anfinsen showed that these were S-S bonded network = he called “scrambled” Critical question is nature of the intermediates as go from here to there: If there was a sequence in which these bonds formed, and one could figure out the sequence or pathway, it might give you considerable information on the steps in the folding pathway. So certainly we need to understand native-fold, and interactions that determine it, stabilize it once formed; However this does not solve problem We will return to the question after reviewing the general anatomy of globular proteins, which will occupy most of next week. 1 General features of 3-D structures of solved proteins; Globular, Soluble proteins: A. Isolation and Crystallization The first crystals of proteins sufficiently large and ordered to diffract X-rays were prepared of the digestive enzyme pepsin: Bernal, J. D., and Dorothy Crowfoot. Nature (1934): 133, 794. This was followed by crystals of insulin, Lactalbumin, hemoglobin, and chymotrypsin: Bernal, Fankuchen, and Perutz (1938) The rise to power of the Nazis in Germany and Italy and the outbreak of war brought all these studies to a halt. -
Phase Transitions and Critical Phenomena: an Essay in Natural Philosophy (Thales to Onsager)
Phase Transitions and Critical Phenomena: An Essay in Natural Philosophy (Thales to Onsager) Prof. David A. Edwards Department of Mathematics University of Georgia Athens, Georgia 30602 http://www.math.uga.edu/~davide/ http://davidaedwards.tumblr.com/ [email protected] §1. Introduction. In this essay we will present a detailed analysis of the concepts and mathematics that underlie statistical mechanics. For a similar discussion of classical and quantum mechanics the reader is referred to [E-1] and [E-4]. For a similar discussion of quantum field theory the reader is referred to [E-2]. For a discussion of quantum geometrodynamics the reader is referred to [E- 3] Scientific theories go through many stages in their development, some eventually reaching the stage at which one might say that "the only work left to be done is the computing of the next decimal." We shall call such theories climax theories in analogy with the notion of a climax forest (other analogies are also appropriate). A climax theory has two parts: one theoretical, which has become part of pure mathematics; and the other empirical, which somehow relates the mathematics to experience. The earliest example of a climax theory is Euclidean geometry. That such a development of geometry is even possible is not obvious. One can easily imagine an Egyptian geometer explaining to a Babylonian number theorist why geometry could never become a precise science like number theory because pyramids and other such bodies are intrinsically irregular and fuzzy (similar discussions occur often today between biologists and physicists). Archimedes' fundamental work showing that the four fundamental constants related to circles and spheres (C =αr, A = βr2 , S = ϒr 2, V= δr3 ) are all simply related (1/2α=β = 1/4ϒ= 3/4δ= π), together with his estimate that 3+10/71< π < 3+1/7 will serve for us as the paradigm of what science should be all about. -
Toxicological Profile for Acetone Draft for Public Comment
ACETONE 1 Toxicological Profile for Acetone Draft for Public Comment July 2021 ***DRAFT FOR PUBLIC COMMENT*** ACETONE ii DISCLAIMER Use of trade names is for identification only and does not imply endorsement by the Agency for Toxic Substances and Disease Registry, the Public Health Service, or the U.S. Department of Health and Human Services. This information is distributed solely for the purpose of pre dissemination public comment under applicable information quality guidelines. It has not been formally disseminated by the Agency for Toxic Substances and Disease Registry. It does not represent and should not be construed to represent any agency determination or policy. ***DRAFT FOR PUBLIC COMMENT*** ACETONE iii FOREWORD This toxicological profile is prepared in accordance with guidelines developed by the Agency for Toxic Substances and Disease Registry (ATSDR) and the Environmental Protection Agency (EPA). The original guidelines were published in the Federal Register on April 17, 1987. Each profile will be revised and republished as necessary. The ATSDR toxicological profile succinctly characterizes the toxicologic and adverse health effects information for these toxic substances described therein. Each peer-reviewed profile identifies and reviews the key literature that describes a substance's toxicologic properties. Other pertinent literature is also presented, but is described in less detail than the key studies. The profile is not intended to be an exhaustive document; however, more comprehensive sources of specialty information are referenced. The focus of the profiles is on health and toxicologic information; therefore, each toxicological profile begins with a relevance to public health discussion which would allow a public health professional to make a real-time determination of whether the presence of a particular substance in the environment poses a potential threat to human health. -
Thermodynamic Derivation of Scaling at the Liquid–Vapor Critical Point
entropy Article Thermodynamic Derivation of Scaling at the Liquid–Vapor Critical Point Juan Carlos Obeso-Jureidini , Daniela Olascoaga and Victor Romero-Rochín * Instituto de Física, Universidad Nacional Autónoma de México, Apartado Postal 20-364, Ciudad de México 01000, Mexico; [email protected] (J.C.O.-J.); [email protected] (D.O.) * Correspondence: romero@fisica.unam.mx; Tel.: +52-55-5622-5096 Abstract: With the use of thermodynamics and general equilibrium conditions only, we study the entropy of a fluid in the vicinity of the critical point of the liquid–vapor phase transition. By assuming a general form for the coexistence curve in the vicinity of the critical point, we show that the functional dependence of the entropy as a function of energy and particle densities necessarily obeys the scaling form hypothesized by Widom. Our analysis allows for a discussion of the properties of the corresponding scaling function, with the interesting prediction that the critical isotherm has the same functional dependence, between the energy and the number of particles densities, as the coexistence curve. In addition to the derivation of the expected equalities of the critical exponents, the conditions that lead to scaling also imply that, while the specific heat at constant volume can diverge at the critical point, the isothermal compressibility must do so. Keywords: liquid–vapor critical point; scaling hypothesis; critical exponents Citation: Obeso-Jureidini, J.C.; 1. Introduction Olascoaga, D.; Romero-Rochín, V. The full thermodynamic description of critical phenomena in the liquid–vapor phase Thermodynamic Derivation of transition of pure substances has remained as a theoretical challenge for a long time [1].