Structure of Water, Proteins, and Lipids in Intact Human Skin, Hair, and Nail

Abstract The Soret effect describes diffusive motion that originates from a temperature gradient. It is observed in mixtures of gases, liquids and even solids. Although there is a formal phenomenological description based on linear nonequilibrium thermodynamics, the Soret effect is a multicause phenomenon and there is no univocal microscopic picture. After a brief historical overview and an outline of the fundamental thermodynamic concepts, this review focuses on thermodiffusion in binary and ternary liquid mixtures. The most important experimental techniques used nowadays are introduced. Then, a modern development in studying thermal diffusion, the discovery of both integral and specific additivity laws, is discussed. The former relate to the general behavior of the substances in a temperature field according to their thermophobicities, which prove to be pure component properties. The thermophobicities allow for a convenient classification of the phenomenon, a simple interpretation and a proper estimation and prediction of the thermodiffusion parameters. The specific laws relate to the additivity of the particular contributions. Among the latter, we discuss the isotopic Soret effect and the so-called chemical contribution. From the theoretical side, there are kinetic and thermodynamic theories, and the nature of the driving forces of thermodiffusion can be either of volume or surface type. Besides analytical models, computer simulations become increasingly important. Polymer solutions are special as they represent highly asymmetric molecular systems with a molar mass-independent thermophoretic mobility. Its origin is still under debate, and draining and non-draining models are presently discussed. Finally, some discussion is devoted to ternary mixtures, which only recently have been investigated in more detail.

The Soret Effect in Liquid Mixtures – A Review

Low-frequency Raman spectra of ethanol−water binary solutions with varying mixing ratios are measured and presented in the form of the intrinsic Raman scattering activity, the R(ν) spectra. They exhibit an isosbestic point at 135 cm-1 between the pure water O−O stretching peak at 185 cm-1 and that of pure ethanol at 110 cm-1. The R(ν) spectra of the binary solutions are found to be decomposed into linear combinations of the R(ν) spectra of pure water and pure ethanol. The plot of the coefficients of linear combinations as a function of ethanol mole fraction xE has an inflection point at xE = 0.2, and the increasing fraction of the ethanol component is compensated with the decreasing fraction of the water component. This can be explained when ethanol−water binary solution does not get ideally mixed on the molecular level and the hydrogen bonds between water associates and ethanol associates become weak owing to the collective molecular motion or the sliding motion of the two units.

Low-Frequency Raman Spectroscopy of Ethanol−Water Binary Solution: Evidence for Self-Association of Solute and Solvent Molecules

Recently it has become apparent that for quantitative studies the I(ω) Raman spectrum measured directly from the spectrometer must be corrected for temperature and frequency factors to give a reduced Raman spectrum, R(ω), which is directly proportional to the intrinsic molar scattering factor. Although generally applicable, the R(ω) spectrum finds its greatest application in the low-frequency region of hydrogen-bonded and simple molecular liquids and solids. In this paper the general applicability of the R(ω) format is discussed with respect to the low-frequency spectra observed for simple molecular and more complicated hydrogen-bonded liquids and solids. Examples are chosen from S8(s), H2O(I), SO2(g) and SO2(I) and CH3CN(I). Further arguments are presented to stress the need to use temperature- and frequency-corrected band shapes for Raman component bands at non-zero frequency when attempting to deconvolute the Rayleigh band at zero frequency into component sub-bands.

Assessment of correction procedures for reduction of Raman spectra

Publisher Summary This chapter discusses advances in the theoretical and physical aspects of spin–spin coupling constants. From both theoretical and experimental points of view, the analysis of high-resolution NMR parameters is an important problem, and its significance for the understanding of molecular electronic structure can hardly be stressed enough. When both approaches are taken together, an excellent example of the Born–Opperheimer approximation is obtained because experimentalists measure transitions among nuclear states that are modified by the interactions among magnetic nuclei, external magnetic field, and electrons, while theoreticians study the way the electronic wave function is modified owing to those interactions. The empirical Hamiltonian describes the way nuclear spin energy levels are modified both by the static magnetic field provided by a spectrometer and by the interactions between magnetic nuclei and electrons belonging to a given molecule.

Advances in theoretical and physical aspects of spin-spin coupling constants

Comparison of depolarized rayleigh-wing scattering and far-infrared absorption in molecular liquids

Low frequency Raman spectra from 20 to 400 cm−1 of liquid HCONH2, HCOND2, and HCO 15NH2 were studied Experimental data were directly transformed to the R(v) representation, previously described Assignments of low frequency bands are discussed based on a comparison between frequencies for the isotopic species and measurements of depolarization ratios Chain structures are the dominant species An out‐of‐plane intermolecular mode involving atoms in the hydrogen bond was assigned The frequency for this mode decreased with increasing temperature

Hydrogen bonding in liquid formamide. A low frequency Raman study

/pdf/the-crystal-structure-of-tetrapyridine-copper-i-perchlorate-2d2o7di8f4.pdf

The Crystal Structure of Tetrapyridine Copper(I) Perchlorate and Tetrapyridine Silver(I) Perchlorate at 260 K.

Low frequency Raman spectra (20–250 cm−1) of liquid CH3COOH, CH3COOD, and CD3COOD at room temperature were studied. The experimental data were directly transformed to the R(ν) representation, previously described. The three Raman active intermolecular vibrations of the cyclic dimer (C2h symmetry) were assigned by use of depolarization ratios and a comparison of vibrational frequencies for the different isotopic molecules.

Intermolecular Raman active vibrations of hydrogen bonded acetic acid dimers in the liquid state

Low-frequency Raman spectra of liquid formamides and aqueous solutions of formamide

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

P.-A. Lund

Author Tools

Chat about Author