bluuebunny/crossref_metadata_2025_split huggingface dataset:
Trichroic Infrared Measurements of Orientation
Authors: Koenig Jack L. 
Published: September 2006

Abstract
Orientation can be defined as the preferential alignment (either uniaxial or biaxial) of polymer chains or segments when submitted to an external force. The orientation induces significant changes in the properties both positively and negatively. Oriented polymers are generally anisotropic; the properties along a particular direction being affected according to the conditions of stretching along that direction. Stretching in one direction produces uniaxial materials. Stretching in two mutually perpendicular directions produces biaxial materials. In reality, many polymers have orientation with a three‐dimensional character. It is therefore necessary to obtain a structure factor to determine the relative amounts of the structural components in the sample (A is absorbance) in the presence of orientation. The three‐dimensional orientation function can be measured using an infrared technique based on an infrared absorption intensity ellipsoid approximation coupled with a sample tilting procedure. Angle‐dependent absorption information is obtained from a tilting apparatus. The sample is mounted on the tilting stage in a preferred direction. The device is constructed such that the sample can be rotated about a horizontal or vertical axis, both of which are orthogonal to the direction of propagation. The apparatus is interfaced with a computer for automated and precise tilting control. A wire grid polarizer is used to polarize the incident light beam. Three‐dimensional information is obtained by the rotation of the bulk sample on the axis perpendicular to the incident electric vector. The method is demonstrated for uniaxially drawn polyethylene terephthalate and phase I of poly(vinylidene fluoride) (PVDF) oriented and annealed both under stress and without stress.
Vibrational Circular Dichroism
Authors: Nafie Laurence A. , Dukor Rina K. , Freedman Teresa B. 
Published: September 2006

Abstract
A brief history of the development of the experimental and theoretical aspects of infrared and Raman vibrational optical activity (VOA) is provided as an introduction. The infrared form of VOA is known as vibrational circular dichroism (VCD) and the Raman form is known as vibrational Raman optical activity (ROA). VCD is defined as the difference in the absorbance of a chiral molecule for left versus right circularly polarized radiation during a vibrational transition. The principal areas of coverage of VCD include the theory of VCD and its relation to measured spectra, instrumentation used for the measurement of VCD including intensity standards and commercially available instruments, methods used for the ab initio calculation of VCD spectra, and advanced instrumental techniques. The principal applications of VCD include determination of absolute configuration, enantiomeric purity, and solution‐state conformational populations. A concluding section predicts substantial growth in the application of VCD as theoretical and instrumental methods improve in the future.
R
aman Optical Activity Spectroscopy
Authors: Hug Werner 
Published: September 2006

Abstract
The diastereomeric interaction of circularly polarized light with chiral matter in Raman scattering is called Raman optical activity (ROA). The relative merits of measuring vibrational optical activity in transmission and by scattering are briefly discussed in their historic context. The possibility of choosing the scattering geometry and the polarization scheme can provide information not available from a transmission experiment, with the integral circular difference scattering cross sections the equivalent of circular difference extinction coefficients. The theoretical expressions are cast into a form which allows a graphical representation of the way in which Raman and ROA intensities are generated in a vibrating molecule. It is shown that excellent agreement between ab initio computed and measured ROA backscattering spectra is possible, and that appropriately summed ROA intensities are a measure of the influence the chirality of the electron distribution has on the ROA.
Electromagnetic Mechanism of Surface‐Enhanced Spectroscopy
Authors: Schatz George C. , Van Duyne Richard P. 
Published: September 2006

AbstractThe sections in this article areIntroductionElectromagnetic Mechanism of Surface‐EnhancedRaman Spectroscopy for Isolated Metal ParticlesA simple Model: Quasistatic Treatment of an Isolated SphereElectrostatics of Isolated SpheroidsImprovements to the Spheroid ModelElectrodynamic CorrectionsSize‐Dependent Dielectric ConstantsCurrent Status of Theory/Experiment ComparisonsExtensions of the Electromagnetic ModelEffect of Adsorbed Layers on IntensitiesNonlinear Surface Optical ProcessesElectromagnetic Mechanism for Many Coupled Particles and for GratingsConclusions and Further WorkAcknowledgments
Inelastic Electron Tunneling Spectroscopy
Authors: Hipps K.W. , Mazur U. 
Published: September 2006

Abstract

The basic concepts of scanning tunneling microscopy (STM) are reviewed, with emphasis on instrumentation appropriate for spectroscopic applications. Applications of scanning tunneling spectroscopy to semiconductor and metal surfaces are discussed. Focus is then placed on the spectroscopy of single molecules adsorbed on surfaces. Examples of molecular images with sub‐molecular resolution are provided. Both inelastic electron tunneling spectroscopy (IETS) and orbital mediated tunneling spectroscopy (OMTS) are discussed. Molecular electronic spectra (OMTS) are displayed and contrasted with results from techniques requiring large (>10
9
) numbers of molecules. Correlation between the nanoscale method of OMTS, and the microscale methods of ultraviolet photoelectron spectra (UPS) and electrochemical oxidation and reduction potentials will be made. Mapping of electron transport paths through a molecule and mapping of chemical components on a surface are both addressed.
High‐Resolution Electron Energy Loss Spectroscopy
Authors: Chesters Michael A. 
Published: September 2006

Abstract
The sections in this article are

Introduction

Instrumentation

Resolution Enhancement

Multiplexing Spectrometers

Excitation Mechanisms and Selection Rules

Dipole Scattering

Impact Scattering

Resonant Scattering

Surface Phonon Spectra

Current Status and Future Prospects
Inelastic Neutron Scattering Spectroscopy
Authors: Parker Stewart F. 
Published: September 2006

AbstractInelastic neutron scattering (INS) spectroscopy is a technique that allows the vibrational spectra of solid materials to be obtained. The interaction of the probe is with the nucleus rather than with the electrons, and this results in significant differences with infrared and Raman spectroscopies. In particular, there are no selection rules, intensities are straightforward to calculate and motions involving hydrogen dominate the spectrum. The instrumentation used at both continuous (reactor) and pulsed (spallation) neutron sources is described. The applications of INS spectroscopy span biology to materials science to geology to engineering in addition to physics and chemistry. Particularly active areas include—catalysis, polymers, magnetism, hydrogen‐in‐metals, hydrogen‐bonding, glasses and fullerenes. Four recent uses of INS in the areas of hydrodesulfurization catalysis, polyethylene, the hydrogen‐in‐metals systems γ‐ZrH and α‐MnH0.073and in the two studies of proteins (staphyloccal nuclease and collagen) are described.
Infrared Cavity Ringdown Spectroscopy
Authors: Wagner Donald R. , Miller George P. , Winstead Christopher B. 
Published: September 2006

Abstract

Coherent two‐dimensional vibrational spectroscopies use multiple laser excitations at high intensities where nonlinear processes dominate. These new spectroscopies can potentially probe molecular structure and dynamics in complex systems like multidimensional
nuclear magnetic resonance
(NMR) methods. We describe the development of the optical analogue to two‐dimensional NMR and its unique capabilities for achieving spectral selectivity. The approach uses four‐wave mixing where three lasers are focused onto a sample and new beams are generated by nonlinear processes. Their intensity depends on whether there are vibrational resonances with the three lasers. We have named these methods doubly vibrationally enhanced four wave mixing (DOVE‐FWM). These methods are related to infrared and Raman spectroscopy, but they are capable of dissecting vibrational spectra into the components that they are made of. These methods offer the potential of a powerful new probe of intra‐ and intermolecular interactions, molecular structure, and molecular dynamics.
Wavenumber Standards for Mid‐infrared Spectrometry
Authors: Hanssen Leonard M. , Zhu Changjiang 
Published: September 2006

Abstract
The sections in this article are

Introduction

Vapor‐Phase Standards

Condensed‐Phase Standards

Calibration Methodology

Sources of Error

Use of Low‐ versus High‐Resolution Standards

Absorption Band (Peak) Wavenumber Evaluation Methods

Conclusions
Ordinate Scale Standards for Mid‐Infrared Spectrometry
Authors: Clarke Frank J.J. 
Published: September 2006

Abstract
The sections in this article are

Needs and Applications for Mid‐Infrared Standards

Instrumental Problems of

IR

Spectrophotometers

Mid‐Infrared Spectrophotometric Standards Facilities and Methods

Standards Work at the

NIST

Standards Work at the

NPL

Standards Work at

PTB

Testing for Ordinate Errors in

FT

Spectrophotometers

The Future for Mid‐Infrared Standards
Wavenumber Standards for
R
aman Spectrometry
Authors: Carrabba Michael M. 
Published: September 2006

Abstract
This chapter describes the use of wavenumber standards for the calibration of Raman instruments. Methods using both The American Society for Testing and Materials (ASTM) Raman shift standard, which was developed to provide accurate wavenumber shifts from readily available commercial materials, and the use of atomic based lines are presented. The Raman shift standard materials have an advantagein that they can then be utilized to calibrate any Raman spectrometer, including spectrometers that use variable excitation sources. They provide an easy way to routinely calibrate an instrument using the actual collection geometry of the apparatus. The use of atomic based lines can provide a more accurate calibration of a spectrometer.
Raman shift standard, calibration, wavenumber, atomic lines, ASTM, 4‐acetamidophenol.
Open‐Path
F
ourier Transform Infrared Spectroscopy
Authors: Russwurm George M. , Childers Jeffrey W. 
Published: September 2006

Abstract
The sections in this article are

Introduction

Historical Perspective

Current State of the Art

Principles of

OP
/
FT
‐
IR

Monitoring

Optics

Transfer Optics

Telescopes

Retroreflectors

IR
Sources

Detectors

Monitoring Configurations

Monostatic Configurations

Bistatic Configurations

Siting and Selection of Monitoring Paths

Data Acquired

B
eer's Law

Interferograms and Single‐Beam Spectra

Background Spectra

Absorption Spectra

Concepts of Path‐Averaged and Path‐Integrated Concentrations

Instrumental Parameters

Measurement Time

Spectral Resolution

Apodization and Zero Filling

Atmospheric Effects

Data Analysis

Preparation of Field Spectra for Analysis

Correcting Single‐Beam Spectra for Stray Light or Ambient Radiation

Baseline Correction

Correcting Absorption Spectra for Wavenumber Shifts

Generating Reference Spectra

Analysis Methods

Nonlinear Response

Quality Control Issues

Measurement of the Random Noise

Relative Intensities in Single‐Beam Spectra

Time Series Plots

Correlation Plots

Statistics from Multivariate Analyses

Estimation of Detection Limits

Accuracy and Precision

Measurement of Permanent Gases

Short Cell

Comparability

Applications

Future Directions
Reflection–Absorption Spectroscopy of Thin Films on Metallic Substrates
Authors: Umemura Junzo 
Published: September 2006

Abstract
The sections in this article are

Introduction

Mathematical Treatments and Characteristics of

RAS

Isotropic Film

Uniaxial Film

Evaluation of Molecular Orientation Using

RAS

Comparison with
KBr
Pellet Spectra

Comparison with Transmission Spectra on

IR

‐Transparent Substrates

RAS

Measured with Unpolarized Light

Application to the Study of Thin Films

L
angmuir–
B
lodgett Films

Self‐Assembled Monolayers

Vacuum‐Evaporated Films

Conclusion
Infrared Spectrometry of Thick Organic Films on Metallic Substrates
Authors: Merklin Gregory T. 
Published: September 2006

Abstract
The sections in this article are

Introduction

Optical Theory

Computational Implementation

Computational Results

General

Effects of Film Thickness

Calculations with Respect to Angle

Determination of Adherence to
B
eer's Law

Experimental

General

Polystyrene Films

Beverage‐Can Lining Film

Results and Discussion

Results for Polystyrene Samples

Beverage Can Samples

Changes with Respect to Angle

RAIRS

vs Transmission Spectra

Analysis of

s

‐Polarized Spectra

Conclusions

Acknowledgments
F
ourier Transform Surface Plasmon Resonance
Authors: Corn Robert M. , Weibel Stephen C. 
Published: September 2006

Abstract
The sections in this article are

Introduction to
F
ourier Transform Surface Plasmon Resonance

Surface Plasmon Resonance in the Near‐Infrared

Experimental
F
ourier Transform Surface Plasmon Resonance

Applications of
F
ourier Transform Surface Plasmon Resonance Measurements

Summary
Infrared Spectroscopic Ellipsometry
Authors: Röseler Arnulf , Korte Ernst‐Heiner 
Published: September 2006

AbstractThe experimental and the evaluation methods of infrared ellipsometry are outlined. The results provide a highly reliable basis for further interpretation, for example, material properties or molecular orientation. Various applications demonstrate the scope of the method.Infrared ellipsometry is a reflection technique for determining the optical properties of a sample. It is advantageously employed to characterize layers down to nanometer thickness. The two experimental results obtained per spectral data point can be evaluated for the sample's optical constants (refractive and absorption index or the complex dielectric function) by strict application of optical theory. In addition, the layer thickness is available since it is independent of the wavelength and the generally applied interferometers cover a wide spectral interval. The evaluation can be extended to anisotropic optical properties.
Principles, Theory and Practice of Internal Reflection Spectroscopy
Authors: Mirabella Francis M. 
Published: September 2006

Abstract
The theoretical principles of internal reflection spectroscopy (IRS), also known as attenuated total reflectance (ATR) spectroscopy, are discussed. The origin of the absorption spectra in the IRS configuration with a lower refractive index sample material in contact with the higher refractive index internal reflection element (IRE) is described. The significance and differences in the depth of penetration and the effective thickness parameters are discussed in detail. An experimental strategy is described for the determination of the actual depth of sampling into the rarer sample material, and the quantitative comparison of the so‐determined “sampling depth” is compared to the theoretical depth of penetration. A comparison of the thick (bulk) film and thin film cases is given. A discussion of the practical considerations necessary to perform experimental IRS measurements is given, including necessary considerations for quantitative calibration. Several results of quantitative determinations on polymers are presented to exemplify the calibration procedures.
Optics and Sample Handling for Near‐Infrared Diffuse Reflection
Authors: Eilert Arnold J. , Wetzel David L. 
Published: September 2006

AbstractThe sections in this article areIntroductionFundamentals of Near‐Infrared Diffuse Reflection AnalysisCharacteristics of Diffusely Reflected RadiationMeasurement of Diffusely Reflected RadiationSpecial Considerations for Quantitative AnalysisGeneral Spectrometer Design Considerations for Near‐Infrared Diffuse Reflection AnalysisSample Preparation and PresentationPowders, Granulates, and GrainsLiquids and PastesIntact Solids and In‐Container SamplingOn‐Line Sampling StrategiesDiffuse Transmission for Special ApplicationsDiffusely Reflected Near‐Infrared Radiation Collection SchemesIntegrating SpheresClose Proximity DetectorsBifurcated Fiber Optic Emitters/ReceptorsSpecial Optics for Small SamplesNoncontact/Remote Sampling OpticsDiffuse Reflection Reference Measurements
Integrating Spheres for Mid‐ and Near‐Infrared Reflection Spectroscopy
Authors: Hanssen Leonard M. , Snail Keith A. 
Published: September 2006

Abstract
The sections in this article are

Introduction

Terminology

Historical Review

Theory of Sphere Throughput

Reflectance Techniques

Absolute Reflectance Methods

Relative Reflectance Methods

Dealing with Error Sources: Sphere Design Considerations

Detector Field of View and Sphere Symmetry

Baffle Design

Coating and Sample

BRDF

Flat versus Curved Samples

Port Design

Modern Sphere Instrumentation for Spectroscopy

Summary and Discussion

Disclaimer

Appendix
Morphology‐Dependent
R
aman Measurements
Authors: Popp Jürgen , Kiefer Wolfgang 
Published: September 2006

Abstract
The sections in this article are

Introduction

Trapping of Single Particles

Laser Light Traps for Studying Single Microparticles

Electrodynamic Trap

Morphology‐Dependent Resonances

R
aman/
Mie
Scattering from Single Levitated Microparticles

Evaporation Behavior of Single Microdroplets

Chemical Reactions in Single Microdroplets

Microparticle Investigations Using an Optical Gradient Force Trap

Single Laser‐Trapped Dielectric Microparticles

Single Laser‐Trapped Gas Bubbles

Summary

Acknowledgments
Instrumentation forFT‐IRImaging
Authors: Kidder Linda H. , Haka Abigail S. , Lewis E. Neil 
Published: September 2006

AbstractInfrared (IR) spectroscopic imaging is the complete synthesis of IR spectroscopy with sample visualization and greatly extends the capabilities of conventional IR spectroscopy. The technique can be used to explore the heterogeneity of a single sample, or as a parallel spectroscopic technique to characterize multiple samples simultaneously. The historical development of IR arrays, one of the key enabling technologies, is discussed. Current instrumental implementations, design criteria specific to imaging systems, and signal‐to‐noise considerations for step‐scan systems are presented. One of the benefits of vibrational spectroscopic imaging is the vast amount of spectral and spatial data that is obtained. To optimize data mining strategies for these data sets, a variety of multivariate and statistical approaches are summarized. Specific applications in polymer, agricultural, and biomedical fields are shown, which serve to elucidate the varied applications and utility of the technique.
Near‐Infrared Microspectroscopy
Authors: Hammond Stephen V. , Clarke Fiona C. 
Published: September 2006

Abstract
Microscopic near‐infrared (NIR) spectroscopy can provide low‐level matrix information on the composition and distribution of ingredients within an intact pharmaceutical blend or tablet. NIR spectral data can be collected either by point‐by‐point spectral acquisitions (point mapping) or by global illumination of the sample (global imaging) and by image collection at individual wavelengths. On combination, these wavelength images create a hyperspectral data cube, whereby following a defined pixel through the data cube gives rise to an NIR spectrum. Therefore, both techniques provide similar information with both the spectral and spatial characteristics of the sample obtained.
Microscopic NIR has potential applications for pharmaceutical analysis, although there are on‐going discussions about appropriate analysis conditions and the actual contributing volume to a single spectrum. The latter obviously impacts spectral interpretation, and as such a wide range of analysis tools are used to obtain a chemical image. Using microscopic NIR, four different pharmaceutical issues have been examined, from pretabletting blends through final dosage forms. By use of multivariate and image analysis methods it has been possible to extract useful chemical information and create ‘visual’ images of the sample. These images provide information on the size, shape, and distribution of each component within the formulation. This information has been utilized in studies of flow issues, tablet sticking and chipping during manufacture, and understanding moisture uptake in dosage forms.
Microscopic NIR has been used to improve knowledge and understanding of pharmaceutical processes and potentially, with increased acquisition and processing time, could be used to control pharmaceutical production.
General Introduction to Fiber Optics
Authors: Lewis I.R. , Rosenblum S.S. 
Published: September 2006

Abstract
Their excellent transmission capabilities coupled with mechanical flexibility has led optical fibers to be deployed as sampling accessories in the field of vibrational spectroscopy. In this chapter, an introduction to basic terms such as numerical aperture, acceptance angles, overfilling, underfilling, bend radius, core, cladding, single‐mode fibers, multimode fibers, step and graded index fibers is provided. The general principles of operation of optical fibers and a broad background of some of the important issues surrounding the use of optical fibers in spectroscopy are given. The suitability of the different types of optical fibers for specific spectroscopic measurements is discussed.
Fiber‐Optic Probes forRaman Spectrometry
Authors: Lewis Ian R. , Lewis Mary L. 
Published: September 2006

AbstractHistorically, one of the limitations to the acceptance of Raman spectrometry outside the photonics laboratory has been sampling. Despite the fact that common containers such as cuvettes, glass bottles, and plastic bags can be used as sample holders, alignment of these holders to a Raman instrument using 90° geometry had relegated Raman spectrometry to the realm of the researcher. Fiber‐optic probe designs using both a 180°‐backscatter geometry and the flexibility of fiber‐optic cables coupled to a new generation of Raman analyzers have tremendously increased sampling ease and applicability. Now the analyst has the ability to take the sampling point to the sample rather than the other way around. This versatility has opened up many disparate new areas of study, for example, process monitoring, remote identification of hazardous wastes, in vivo medical diagnostics, art and antiquities etc. In this chapter, the design criteria, advantages, and limitations of several different probe head designs are discussed.