Author: Publisher: ISBN: Category : Languages : en Pages : 0
Book Description
We present the first experimental measurements of the orientation and hydrogen bonding character of interfacial water molecules in their gaseous state in coexistence with the bulk liquid water. These interfacial vapor state molecules are distinct from the surface free OH and the interfacial liquid state water molecules and show a preferred orientation with their hydrogen atoms directed towards the liquid surface. The goal to develop a molecular level picture of water orientation and bonding at this vapor-liquid boundary where liquid phase water molecules coexist with vapor phase molecules has fascinated scientists for decades. Whereas most theoretical and experimental studies in recent years are converging on a consistent description of interfacial water on the liquid side of the interface, there is considerable disparity in the theoretical description of water molecules on the vapor side. A primary factor in this lack of consensus is the paucity of available data that unequivocally measures the properties of these interfacial vapor state molecules. As with theoretical efforts in this area, the low density of these vapor state interfacial water molecules is experimentally problematic. In this paper we present the first vibrational spectroscopic measurements of interfacial water vapor species in coexistence with their liquid phase. These detected vapor state molecules have a preferred orientation relative to the surface plane and have minimal hydrogen bonding to adjacent water molecules as manifested in the energy and linewidth of the spectral OH stretching modes examined. These molecules are distinctly different than the water molecules with a dangling bond into the vapor phase, or water in the liquid portion of the interface where hydrogen bonding between water molecules is strong.
Author: Jennifer A. Faust Publisher: Elsevier ISBN: 0128136421 Category : Science Languages : en Pages : 492
Book Description
Physical Chemistry of Gas-Liquid Interfaces, the first volume in the Developments in Physical & Theoretical Chemistry series, addresses the physical chemistry of gas transport and reactions across liquid surfaces. Gas–liquid interfaces are all around us, especially within atmospheric systems such as sea spry aerosols, cloud droplets, and the surface of the ocean. Because the reaction environment at liquid surfaces is completely unlike bulk gas or bulk liquid, chemists must readjust their conceptual framework when entering this field. This book provides the necessary background in thermodynamics and computational and experimental techniques for scientists to obtain a thorough understanding of the physical chemistry of liquid surfaces in complex, real-world environments. 2019 PROSE Awards - Winner: Category: Chemistry and Physics: Association of American Publishers Provides an interdisciplinary view of the chemical dynamics of liquid surfaces, making the content of specific use to physical chemists and atmospheric scientists Features 100 figures and illustrations to underscore key concepts and aid in retention for young scientists in industry and graduate students in the classroom Helps scientists who are transitioning to this field by offering the appropriate thermodynamic background and surveying the current state of research
Author: Publisher: ISBN: Category : Languages : en Pages :
Book Description
Distributions of binding energies of a water molecule in the water liquid-vapor interface are obtained on the basis of molecular simulation with the SPC/E model of water. These binding energies together with the observed interfacial density profile are used to test a minimally conditioned Gaussian quasi-chemical statistical thermodynamic theory. Binding energy distributions for water molecules in that interfacial region clearly exhibit a composite structure. A minimally conditioned Gaussian quasi-chemical model that is accurate for the free energy of bulk liquid water breaks down for water molecules in the liquid-vapor interfacial region. This breakdown is associated with the fact that this minimally conditioned Gaussian model would be inaccurate for the statistical thermodynamics of a dilute gas. Aggressive conditioning greatly improves the performance of that Gaussian quasi-chemical model. The analogy between the Gaussian quasi-chemical model and dielectric models of hydration free energies suggests that naive dielectric models without the conditioning features of quasi-chemical theory will be unreliable for these interfacial problems. Multi-Gaussian models that address the composite nature of the binding energy distributions observed in the interfacial region might provide a mechanism for correcting dielectric models for practical applications.
Author: Xiao-feng Pang Publisher: World Scientific ISBN: 9814440442 Category : Science Languages : en Pages : 491
Book Description
This book provides a broad and complete introductions to the molecular structure, novel and anomalous properties, nonlinear excitations, soliton motions, magnetization, and biological effects of water. These subjects are described by both experimental results and theoretical analyses. These contents are very interesting and helpful to elucidate and explain the problem of “what is on earth water”. This book contains the research results of the author and plenty of scientists in recent decades.“Water: Molecular Structure and Properties” is self-contained and unified in presentation. It may be used as an advanced textbook by graduate students and even ambitious undergraduates in Physics and Biology. It is also suitable for the researchers and engineers in Physics, Biology and water science.
Author: Zdeněk P. Bažant Publisher: Springer ISBN: 9402411380 Category : Technology & Engineering Languages : en Pages : 960
Book Description
This comprehensive treatise covers in detail practical methods of analysis as well as advanced mathematical models for structures highly sensitive to creep and shrinkage. Effective computational algorithms for century-long creep effects in structures, moisture diffusion and high temperature effects are presented. The main design codes and recommendations (including RILEM B3 and B4) are critically compared. Statistical uncertainty of century-long predictions is analyzed and its reduction by extrapolation is discussed, with emphasis on updating based on short-time tests and on long-term measurements on existing structures. Testing methods and the statistics of large randomly collected databases are critically appraised and improvements of predictions of multi-decade relaxation of prestressing steel, cyclic creep in bridges, cracking damage, etc., are demonstrated. Important research directions, such as nanomechanical and probabilistic modeling, are identified, and the need for separating the long-lasting autogenous shrinkage of modern concretes from the creep and drying shrinkage data and introducing it into practical prediction models is emphasized. All the results are derived mathematically and justified as much as possible by extensive test data. The theoretical background in linear viscoelasticity with aging is covered in detail. The didactic style makes the book suitable as a textbook. Everything is properly explained, step by step, with a wealth of application examples as well as simple illustrations of the basic phenomena which could alternate as homeworks or exams. The book is of interest to practicing engineers, researchers, educators and graduate students.
Author: Warren H. Finlay Publisher: Elsevier ISBN: 0080511376 Category : Technology & Engineering Languages : en Pages : 323
Book Description
The Mechanics of Inhaled Pharmaceutical Aerosols, An Introduction provides a unique and comprehensive treatment of the mechanics of inhaled pharmaceutical aerosols. The book covers a wide range of topics and many new perspectives are given by drawing on research from a variety of fields. Novel, in-depth expositions of the most common delivery devices are given, including nebulizers, dry powder inhalers and propellant metered dose inhalers. The behaviour of aerosols in the respiratory tract is explained in detail, with complete coverage of the fundamentals of current deposition models. The book begins by providing a comprehensive introduction to aspects of aerosol mechanics that are relevant to inhaled pharmaceutical aerosols. It then gives an exhaustive pedagogical description of the behaviour of evaporating and condensing droplets (both aqueous and propellant-based), an introductory chapter on lung geometry and inhalation patterns, and coverage of relevant aspects of fluid mechanics in the lung. Finally, the book provides invaluable, detailed coverage on the mechanics of common pharmaceutical aerosol delivery systems and deposition in the respiratory tract. Throughout the book are many detailed numerical examples that apply the salient concepts to typical inhaled pharmaceutical aerosols. This book will be of interest to scientists and engineers involved in the research and development of inhaled pharmaceutical aerosol products. Experienced practitioners will find many new perspectives that will greatly enhance their understanding of this complex and rapidly growing field. For those delivering therapeutic agents to the lung, this book is a must-have. Students and academics will find this book an invaluable tool and for newcomers it is a worthy guide to the diverse fields that must be understood to work in the area of inhaled pharmaceutical aerosols.
Author: Michael D. Fayer Publisher: CRC Press ISBN: 1466510145 Category : Science Languages : en Pages : 475
Book Description
The advent of laser-based sources of ultrafast infrared pulses has extended the study of very fast molecular dynamics to the observation of processes manifested through their effects on the vibrations of molecules. In addition, non-linear infrared spectroscopic techniques make it possible to examine intra- and intermolecular interactions and how su
Author: Alexander G. Volkov Publisher: CRC Press ISBN: 9780203908754 Category : Science Languages : en Pages : 878
Book Description
Provides a comprehensive treatment of surface chemistry and its applications to chemical engineering, biology, and medicine. Focuses on the chmical and physical structure of oil-water interfaces and membrane surfaces. Details interfacial potentials, ion solvation, and electrostatic instabilities in double layers.
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Author: Jennifer A. Faust
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Author: Xiao-feng Pang
Author: Zdeněk P. Bažant
Author: Warren H. Finlay
Author: Michael D. Fayer
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Author: Alexander G. Volkov