bluuebunny/crossref_metadata_2025 huggingface dataset:
Characteristics of estrogen decomposition by ozonation
Authors: Hashimoto T. , Takahashi K. , Murakami T.
Published: September 2006

Since the natural estrogens 17 β-estradiol (E2) and estron (E1), and the synthetic estrogen 17 α-ethynyl estradiol (EE2) have strong endocrine disrupting effects and the tendency to persist in effluent from wastewater treatment plants, effective measures are needed to remove them from wastewater. In this research, to gain an understanding of the characteristics of estrogen decomposition by ozonation, experiments were conducted using effluent from an actual wastewater treatment plant. In this experiment, estrogen was added to effluent at a concentration of 200 ng/l and 20 ng/l before the ozonation experiments. The results showed 90% or more of estrogen concentration and estrogenic activity of E2, E1 and EE2 to be removed at an ozone dose of 1 mg/l. At an ozone dose of 3 mg/l, the estrogen concentration and estrogenic activity of E2, E1 and EE2 in the treated water fell below the detection limit. The removal rate was not influenced by the kind of estrogen. No generation of byproducts with estrogenic activity was observed. The authors conclude that estrogen in secondary treated wastewater can be almost entirely removed at the practical ozone dose rate applied for the purpose of disinfection, which is up to about 5 mg/l.
Discussion of an environment quality standard based assessment procedure for permitting discharge
Authors: Gabriel O. , Zessner M.
Published: September 2006

The ‘combined approach’ as a requirement of the EC Water Framework Directive pools an emission-based approach with an approach based on environmental quality standards (EQS) to improve European water quality. The implementation of the EQS-based approach poses problems of defining a reference water discharge, defining a distance, where the EQS are obligatory and thus have to be controlled after point discharge, considering incomplete mixing. To elaborate a simple assessment procedure including the aspects mentioned above is the point of discussion in this paper. On the basis of easily available data and references from several European countries, recommendations for an Austrian assessment procedure are presented.
Environmental risk assessment for quaternary ammonium compounds: a case study from Austria
Authors: Grillitsch B. , Gans O. , Kreuzinger N. , Scharf S. , Uhl M. , Fuerhacker M.
Published: September 2006

Quaternary ammonium compounds (QAC) are widely used as disinfectants, biocides, and detergents, among a variety of other applications. The cationic surface-activity of QAC determines their potential to act as a biocide on both target and non-target organisms. This study aims to provide a broad-based environmental risk characterization and evaluation for selected QAC with particular focus on the situation in Austrian rivers. A modular study design was employed involving environmental exposure characterization, QAC fate and effect analysis in wastewater, ecotoxicological effect characterization, and environmental risk evaluation. A wide array of Austrian surface waters and wastewater effluents were screened for the selected key compounds, benzalkonium chlorides and dialkyldimethylammonium chlorides with different C-chain lengths. Ecotoxicological effect characterization was based on both microbiotests for a set of representative aquatic organisms and a literature review. For risk evaluation, the PEC/PNEC ratio was above 1 for some rivers. Notably, small rivers with a high particulate matter were contaminated with QAC in the case of high water incidents. Hence, for the Austrian sites studied, a QAC-derived risk to sensitive aquatic non-target organisms could not be excluded.
Hydrogen-driven denitrification of wastewater in an anaerobic submerged membrane bioreactor: potential for water reuse
Authors: Rezania B. , Oleszkiewicz J.A. , Cicek N.
Published: September 2006

An anaerobic submerged membrane bioreactor was coupled with a novel hydrogen delivery system for hydrogenotrophic denitrification of municipal final effluent containing nitrate. The biological treatment unit and hydrogen delivery unit were proven successful in removing nitrate and delivering hydrogen, respectively. Complete hydrogen transfer resulted in reducing nitrate below detectable levels at a loading of 0.14 kg N m−3 d−1. The produced water met all drinking water guidelines except for color and organic carbon. However, the organic carbon was removed by 72% mostly by membrane rejection. To reduce the organic carbon and color of the effluent, post treatment of the produced water is required.
Ammonia removal in the catalytic wet air oxygen process of landfill leachates with Co/Bi catalyst
Authors: Li Y. , Liu L. , Huang G.H. , Zhu L.
Published: September 2006

Oxidation of ammonia in landfill leachates in the catalytic wet air oxidation (CWAO) process was investigated with Co/Bi catalyst. The characterization of the Co/Bi catalyst was carried out by the X-ray diffraction technique. Studies of ammonia removal from the landfill leachates by CWAO showed that Co/Bi catalyst exhibited higher activities for both total organic carbon (TOC) and ammonia with removal levels of 99% for TOC and 98% for ammonia, respectively. Results also indicated that large amounts of ammonia were produced during the elimination of nitrogenous organic compounds in the CWAO process and the further oxidation of ammonia gave off essentially N2 under 240 °C. When the system temperature reached above 240 °C, ammonia oxidation rate was much higher with nitrate dominating in the effluent; a very small amount of nitrite was observed in the reaction process, it possibly acts as the intermediate of nitrate ion and molecular nitrogen formation, showing that the system temperature had significant effects on the ammonia oxidation and reaction selectivity towards the production of molecular nitrogen or nitrate.
Examining the influence of substrates and temperature on maximum specific growth rate of denitrifiers
Authors: Mokhayeri Y. , Nichols A. , Murthy S. , Riffat R. , Dold P. , Takacs I.
Published: September 2006

Facilities across North America are designing plants to meet stringent limits of technology (LOT) treatment for nitrogen removal (3–5 mg/L total effluent nitrogen). The anoxic capacity requirements for meeting LOT treatment are dependent on the growth rates of the denitrifying organisms. The Blue Plains Advanced Wastewater Treatment Plant (AWTP) is one of many facilities in the Chesapeake Bay region that is evaluating its ability to meet LOT treatment capability. The plant uses methanol as an external carbon source in a post-denitrification process. The process is very sensitive to denitrification in the winter. One approach to improve anoxic capacity utilization is to use an alternative substrate for denitrification in the winter to promote the growth of organisms that denitrify at higher rates. The aim of this study was to evaluate denitrification maximum specific growth rates for three substrates, acetate, corn syrup and methanol, at two temperatures (13 °C and 19 °C). These temperatures approximately reflect the minimum monthly and average annual wastewater temperature at the Blue Plains AWTP. The results suggest that the maximum specific growth rate (μmax) for corn syrup (1.3 d−1) and acetate (1.2 d−1) are higher than that for methanol (0.5 d−1) at low temperature of 13 °C. A similar trend was observed at 19 °C.
Photocatalytic oxidation of low concentration 2,4-D solution with new TiO2 fiber catalyst in a continuous flow reactor
Authors: Terashima Y. , Ozaki H. , Giri R.R. , Tano T. , Nakatsuji S. , Takanami R. , Taniguchi S.
Published: September 2006

Environmental pollution by low concentrations of 2,4-Dichlorophenoxyacetic acid (2,4-D) is a concern these days due to ever increasingly stringent regulations. Photocatalysis with immobilized TiO2 fiber is a promising oxidation method. Laboratory experiments on photocatalytic degradation of 0.045 mmol l−1 2,4-D with the world's first high-strength TiO2 fiber catalyst were carried out in a continuous flow reactor in which the degradations were, in general, similar to those with high 2,4-D concentrations investigated elsewhere. Degradation and mineralization of 2,4-D were significantly enhanced with no initial pH adjustments. The rate constants for total organic carbon (TOC) without pH adjustment were about two-fold bigger than the pH adjustment cases. CO2 gas measurement and carbon mass-balance were carried out for the first time, where about 34% organic carbon converted into CO2 gas during four-hour oxidation. 2,4-Dichlorophenol (2,4-DCP), phenol, benzyl alcohol and two unknowns (RT≈2.65 and 3.78 min.) were detected as aromatic intermediates while Phenol was the new aromatic in HPLC analysis. Dechlorination efficiencies were high (>70%) in all the cases, and more than 90% efficiencies were observed in chloride mass balance. Bigger flow rates and solution temperature fixed at 20 °C without pH adjustment greatly enhanced 2,4-D mineralization. These results can be an important basis in applying the treatment method for dioxin-contaminated water and wastewater.
Direct force measurement of bacteria adhesion on metal in aqueous media
Authors: Xiaoxia S. , Peng T.Y. , Olavi P.S.
Published: September 2006

The adhesion of bacteria on metal surfaces in aqueous media and the development of biofilm and resultant biofouling are important phenomena in both the natural environment and engineering systems. This work reports on the use of a force microscopy technique to measure bacterial metal adhesion by two anaerobic sulphate-reducing bacteria (Desulfovibrio desulfuricans and a local marine isolate) and an aerobe (Pseudomonas sp.). Using a modified bacteria tip, the atomic force microscope was able to quantify the attraction and repulsion force in the nano-Newton range between the bacteria cell and metal surface in aqueous media. Results show that increasing surface hydrophobicity of the metal, and increasing the ionic strength of the aqueous medium both enhance the adhesion force. The adhesion forces were also influenced by the physiological properties of the bacterium, such as the bacterial surface charges and hydrophobicity.
Isolation and characterization of thermophilic bacteria capable of lysing microbial cells in activated sludge
Authors: Song Yu-Dong , Hu Hong-Ying
Published: September 2006

To find an efficient biological method to solubilize waste activated sludge (WAS) from the biological wastewater treatment process, several strains of thermophilic bacteria capable of solubilizing WAS were isolated from sewage sludge compost. The culture supernatants of the isolates were able to lyse vegetable bacterial cells and the lytic activity mainly came from the exoenzyme produced by the isolates. The culture supernatants of the different isolates showed different lysis characteristics. The factors affecting bacterial cell lysis were investigated using E. coli as a model bacterium. The E. coli cells were lysed easily at higher temperature (60 °C or 70 °C) while little lytic activity by the supernatants of isolates was observed at lower temperature (50 °C). The level of pH also had great influence on the lysis of E. coli cells. The E. coli cells in the early stationary growth phase were easier to lyse than those in the late stationary growth phase or death phase.
A unique, environmentally sustainable and cost– effective programme to re-vegetate military training lands utilising composted wastewater biosolids at a large Canadian military training centre
Authors: LeBlanc R.J. , Allain C.J. , Downe S. , Pond N. , Laughton P.J.
Published: September 2006

The Greater Moncton Sewerage Commission has developed, in concert with National Defence Canada, an environmentally sustainable and cost effective biosolids management and land reclamation programme at the Canadian Forces Base (CFB) Gagetown, New Brunswick, Canada (the second largest land based Military Training Facility in the British Commonwealth). The use of composted biosolids to re-vegetate military training lands is thought to be a unique application for the beneficial use of biosolids. Results and practical experience gained from this approach to successfully re-vegetate initial sections of extremely large and vast tracts of these lands are described. The paper also overviews the Commission's modern 115 000 m3.d−1 advanced, chemically assisted primary wastewater treatment facility and associated alkaline (lime) sludge stabilisation process. Planning strategies, security aspects, special and unique challenges in operating adjacent to an active military training facility, costs, spreading techniques, monitoring, next steps and conclusions are also presented.
Zero-valent iron treatment of RDX-containing and perchlorate-containing wastewaters from an ammunition-manufacturing plant at elevated temperatures
Authors: Oh S.-Y. , Cha D.K. , Chiu P.C. , Kim B.J.
Published: September 2006

The use of zero-valent iron for treating wastewaters containing RDX and perchlorate from an army ammunition plant (AAP) in the USA at elevated temperatures and moderately elevated temperature with chemical addition was evaluated through batch and column experiments. RDX in the wastewater was completely removed in an iron column after 6.4 minutes Increasing the temperature to 75 °C decreased the required retention time to 2.1 minutes for complete RDX removal. Perchlorate in the wastewater was completely removed by iron at an elevated temperature of 150 °C in batch reactors in 6 hours without pH control. Significant reduction of perchlorate by zero-valent iron was also achieved at a more moderate temperature (75 °C) through use of a 0.2 M acetate buffer. Based on the evaluation results, we propose two innovative processes for treating RDX-containing and perchlorate-containing wastewaters: a temperature and pressure-controlled batch iron reactor and subsequent oxidation by existing industrial wastewater treatment plant; and reduction by consecutive iron columns with heating and acid addition capabilities and subsequent oxidation.
Optimal biodegradation of phenol and municipal wastewater using a controlled sequencing batch reactor
Authors: Buitrón G. , Moreno-Andrade I. , Pérez J. , Betancur M.J. , Moreno J.A.
Published: September 2006

This work presents the results of the application of an optimally controlled influent flow rate strategy to biodegrade, in a discontinuous reactor, a mixture of municipal wastewater and different concentrations of phenol when used as a toxic compound model. The influent is fed into the reactor in such a way to obtain the maximal degradation rate avoiding the inhibition of the microorganisms. Such an optimal strategy was able to manage increments of phenol concentrations in the influent up to 7000 mg/L without any problem. It was shown that the optimally controlled influent flow rate strategy is a good and reliable tool when a discontinuous reactor is applied to degrade an industrial wastewater.
Monitoring the fate of methoprene larvicide for West Nile virus management
Authors: Li J.
Published: September 2006

Since the outbreak of vector-borne West Nile virus in New York City in 1999, the disease has spread across United States and Canada, resulting in the use of larvicides such as methoprene at catch basins for widespread urban mosquito control. Although the manufacturer has recommended a methoprene dosage for catch basin application, the effect of rainfall on this dosage is not known. A field study on the fate of methoprene pellets and ingots was conducted during the summer of 2004 at three catch basins in the City of Toronto, Canada. Water samples from each catch basin were collected daily and during rain storms and analyzed for methoprene concentration using gas chromatography mass spectrometry. It was found that: (1) the methoprene concentration at the catch basin sump fell below the minimum lethal concentration most of the time; (2) rainfall events greater than 25 mm flushed methoprene pellets out of the catch basin; (3) the higher the sump water depth, the higher the residual methoprene concentration at the catch basin sump; and (4) rainfall flushed methoprene from the catch basins into the storm sewer outfall at concentrations much lower than the detrimental level which might cause ecosystem damage.
Duration curve analysis for the assessment of pathogen loading from diffuse sources
Authors: Kim G.H. , Yoon J.Y. , Kim S.W. , Choi E.
Published: September 2006

Pathogen level of surface waters has received great attention for protecting public health. In this study, total coliform, fecal coliform and Escherichia coli concentrations were monitored as the pathogen indicator organisms at six monitoring stations in the Geum River, Korea. Rainfall runoff from two agricultural-forestry watersheds was analyzed for their microbial aspect as well. Total coliform concentration of the Geum River showed high correlation with the flow rate. To estimate total coliform loading on the Geum River in probability scale, the duration curve method was applied. In addition, a standard duration curve reflecting the water quality criteria was constructed to determine water quality compliance. Under the assumption of linearity between flow rate and total coliform concentration of the Geum River, total coliform duration curve revealed that total coliform concentrations exceed the desired criteria mainly due to pollutants from diffuse sources.
Introduction to Vibrational Spectroscopy
Authors: Griffiths Peter R.
Published: September 2006

A brief introduction to the theory of vibrational spectroscopy is given in this chapter. Molecular vibrations are first described in terms of the harmonic oscillator. The Morse potential energy diagram and the concept of anharmonicity are then introduced. The way in which Raman spectra are generated is described in the third section of the article. The factors governing band intensities in infrared and Raman spectra are discussed. In the next section, vibration–rotation spectra of gases are introduced. Then the factors governing the shapes and widths of lines in vapor–phase and condensed‐phase spectra are discussed. In the section on quantitative considerations, Beer's law is described and parameters such as absorptivity, linear absorption coefficient and the optical constants, refractive index, and index of absorption are defined. Finally, a brief introduction to the polarization of radiation is given.
Bandwidths
Authors: Turner James J.
Published: September 2006

The shapes of vibrational bands in solution can provide detailed information about the dynamics of the system. The band shape and the dynamics are related by the Fourier transform relation between frequency and time. The shape is dependent on whether the band is homogeneously or inhomogeneously broadened. Modern vibrational “echo” experiments can distinguish between the two. Most theories of band broadening assume homogeneous broadening. Various dephasing mechanisms contribute to the homogeneous band shape, and the “echo” experiments can unravel – with some surprising results – these contributions. Under appropriate circumstances, dynamic nuclear magnetic resonance (NMR) can provide detailed information about the rate of chemical exchange processes on a “slow” timescale. Under more restrictive conditions, the change in vibrational band shape with temperature can provide the same information but on a “very fast” timescale.
Mid‐Infrared Spectroscopy of the Condensed Phase
Authors: Chalmers John M.
Published: September 2006

This cle introduces some of the main issues that affect the mid‐infrared study of condensed phase samples. It serves as a brief introduction to many of the articles on mid‐infrared spectroscopy that follow in this Handbook. A brief discussion is given of the differences between condensed‐phase (liquid and solid) and gas‐phase absorption band shapes. In the liquid‐state, with some compounds tautomerism can occur such that there is an equilibrium between two or more structural isomers, each of which will have a distinctive spectrum. Many compounds (organic, inorganic, polymeric) are polymorphic, that is they may crystallize into two or more different form. As a consequence of different packing in the crystals each form will have a unique mid‐infrared spectrum, although in some instance the distinctions may only be slight. Mid‐infrared spectroscopy is perhaps the foremost informative technique for studying hydrogen bonding. Enantiomers have indistinguishable mid‐infrared spectra, unless interrogated by the special technique of vibrational circular dichroism (VCD). Many solid materials contain water, either as an integral part of a structure or absorbed within such as a thermoplastic polymer; examples are given of different absorption band profiles in two inorganic systems. Crystal field and factor group splitting of fundamental bands pertaining to crystal structures is discussed, as is the spectra of the disordered state and the influence of defect‐induced structures and spectral changes that occur during the transition in solids from the crystalline through the glassy to the amorphous state. The influences that a sample's bulk physical form and its physical environment may impose on a mid‐infrared spectrum are also introduced. The effects of temperature, pressure, stress and strain on bandwidths and position are briefly considered. For powders, particle size and packing density influences are outlined; the effects of polished and matte surfaces are discussed. For samples such as oriented polymer film or birefringent crystal, alignment of the sample axes with respect to the geometric axes of the spectrometer may have an effect on the relative intensities of bands observed in the recorded spectrum. Their anisotropy may be probed using linearly polarized infrared radiation. Continuous, non‐scattering samples that are uniformly thick may induce multiple passing of the infrared beam within the sample, such that superimposed on a transmission spectrum of the sample one will observe a sinusoidal interference fringe pattern.
Raman Spectroscopy of Gases
Authors: Weber Alfons
Published: September 2006

The sections in this article are

Introduction

SpontaneousRaman Spectroscopy

High‐Resolution Rotation–Vibration Spectra

Use of Interferometers

Raman Line Widths

Intensity Alternation

Supersonic Jet Expansions

VibrationalRaman Spectra

Scattering Cross‐Sections

ResonanceRaman Spectra

Raman Spectroscopy under Extreme Conditions

NonlinearRaman Spectroscopy

Coherent Anti‐StokesRaman Scattering

StimulatedRaman Gain or Loss Spectroscopy

PhotoacousticRaman Scattering

Double Resonance Techniques

Line Widths and Line Shapes

Time‐Domain Nonlinear Spectroscopy

Wavenumber Calibration ofRaman Spectra

Some Applications

Acknowledgments
Near‐Infrared Spectroscopy of Synthetic and Industrial Samples
Authors: Miller Charles E.
Published: September 2006

The sections in this article are

Introduction

Hydrocarbons

Saturated Hydrocarbons

Unsaturated Hydrocarbons

Aromatic Hydrocarbons

Hydrocarbon Polymers

Sample State Effects – Hydrocarbons

Ketones, Esters, Ethers, and Peroxides

Polymers with Ketone, Ester, and Ether Groups

Sample State Effects – Ketones, Esters, Ethers, and Peroxides

Alcohols and Organic Acids

Sample State Effects – Alcohols and Organic Acids

OH‐Containing Polymers

Nitrogen‐Containing Compounds

Sample State Effects – Nitrogen‐Containing Compounds

Halogenated Compounds

Aqueous Systems

Inorganic Materials

Gases

Acknowledgments
Near‐Infrared Spectroscopy of Biomaterials
Authors: McClure W. Fred , Stanfield Donald L.
Published: September 2006

The sections in this article are

Introduction

Historical Perspective

Biological Samples

Qualitative

NIR

Spectroscopy

Fundamental Components

Water, Oil, Protein and Starch

Water

Oil

Protein

Starch

Plant Materials

Grains

Wheat and Wheat Components

Other Grains

Tea

Coffee

Tobacco

Food and Drink

Food

Cereals

Meats, Poultry and Fish

Fresh Fruit

Additives: Molasses, Honey, Corn Syrup and Lemon Extract

Sweets: Sucrose, Saccharin, Extra and Chocolate

Drink

Milk and Water

Ethanol–Water Mixtures

Spirits

Fiber

Cotton, Flax and Wool

Human Samples

Skin

Hair

Blood

Urine

Future Trends in

NIR

Spectroscopy

Hyphenated Systems

Imaging Spectrometry and Remote Sensing

Hand‐Held Spectrometry

Dedication
Resolution and Instrument Line Shape Function
Authors: Griffiths Peter R.
Published: September 2006

The factors that determine the resolution of monochromators operating in both the non‐diffraction‐limited and diffraction‐limited modes are discussed. The instrument line shape function of a monochromator (often called the spectral slit function) operating above the diffraction limit is a triangle, whereas in the diffraction‐limited case it is sinc
2
([sin
x
]
2
/

x
2

) function. For Fourier transform infrared (FT‐IR) spectrometers, the instrument line shape function is a sinc ([sin
x
]/
x
) function unless the interferogram is multiplied by an apodization function. In this case, the instrument line shape function is the Fourier transform of the apodization function. Common apodization functions that are discussed include the triangular function and the three Norton–Beer functions. The effect of a diverging (noncollimated) beam, passing through the interferometer of a FT‐IR spectrometer, on the resolution and instrument line shape function is discussed at the end of the article.
Optical Constants
Authors: Bertie John E.
Published: September 2006

This article starts with the definition of the optical constants, which are the real and imaginary refractive indices, and is largely concerned with liquid samples. It discusses the behavior of optical constants with changing wavenumber, how they may be measured for isotropic materials like liquids, and their relation to other measures of absorption intensity that are more familiar to chemists and to the real and imaginary dielectric constants which are familiar to physicists. The article describes the use of optical constants in the spectroscopy of liquids, and the relation of optical constant spectra to spectra of other intensity quantities. Finally, the article describes the use of optical constants to obtain molecular properties and absolute integrated absorption intensities for liquid samples and shows how their use greatly facilitates the comparison of the intensities of liquids with those of the same compound in the gas phase.
Monochromators for Mid‐Infrared Spectroscopy
Authors: Ford Michael
Published: September 2006

The sections in this article are

Basic Requirements

Early Monochromators

Commercial Monochromators

Early and Unusual Designs

Developments and Adaptations of the
L
ittrow Design

Research Monochromators

Acknowledgments
Infrared Filtometers
Authors: Wilks Paul
Published: September 2006

An infrared filtometer is a selective‐wavelength infrared analyzer which uses narrow band pass optical filters or a linear variable filter to isolate specific wavelengths in the near or mid infrared spectral regions. Infrared filtometers are generally small, portable, operable in the field or in line in the processing plant. Many hundred fixed filter instruments are in use for oil‐in‐water analysis on oil platforms and for effluent water in chemical plants and municipalities. Variable wavelength filtometers monitor ambient air and food properties such as trans fat and alcohol in wine and carbonation and sugar levels in beverages. Recently, filter‐based infrared monitors have been developed for medical diagnostic procedures.

Because of their simplicity, relatively low cost, and adaptability, infrared filtometers are the fastest growing segment of the infrared analytical market with well over 25,000 units in use worldwide.
Continuous Scanning Interferometers for Mid‐Infrared Spectrometry
Authors: Jackson Richard S.
Published: September 2006

This chapter discusses the continuous scanning interferometers that are used primarily for mid‐infrared spectrometry. The chapter initially lays some groundwork by describing the principles of operation of a Michelson interferometer, including the use of a reference laser to control scanning and data acquisition. The chapter then describes sources of error in interferometers, for example velocity and alignment errors, and the different components of an interferometer, such as mirror assemblies and bearings. These sections also cover how the effects of these errors can be controlled using mechanical, optical, and electronic design. The chapter concludes with a number of examples of interferometer design that exemplify the materials discussed in earlier sections.
Incandescent Sources for Mid‐ and Far‐Infrared Spectrometry
Authors: Buijs Henry
Published: September 2006

The sections in this article are

Background

Étendue

Power Emitted by an Ideal Incandescent Source

APractical Mid‐ and Far‐Infrared Source

Other Mid‐ and Far‐Infrared Sources

Very‐Far‐Infrared Spectroscopy

High Resolution Infrared Spectroscopy

IRSpectroscopy with a Synchrotron Source

Terahertz Spectroscopy
Instrumentation for Far‐Infrared Spectroscopy
Authors: Griffiths Peter R. , Homes Christopher C.
Published: September 2006

The various components of far‐infrared spectrometers are discussed in this article. For measurements above 100 cm
−1
, a standard silicon carbide (Globar) source may be used. For longer wavelengths, a high‐pressure mercury lamp is required. When higher radiance is required, synchrotrons emit much higher far‐infrared photon fluxes than either the Globar or the mercury lamp. Pneumatic (Golay) detectors were popular as far‐infrared detectors, as long as the modulation frequency was low. Despite their relatively low sensitivity, pyroelectric bolometers such as the deuterated triglycine sulfate (DTGS) detector are more commonly used because of their better high‐frequency response, which is necessary for Fourier transform infrared (FT‐IR) spectrometry. When very high sensitivity is required, liquid‐helium cooled bolometers are used. Most far‐infrared spectra are measured using an interferometer. In the early days of FT‐IR spectrometry, most interferometers were of the slow continuous‐scan or simple step‐scan variety; lamellar grating interferometers were used for very long‐wavelength measurements. Today, most far‐infrared FT‐IR spectrometers incorporate rapid‐scan interferometers of the same type used for mid‐infrared measurements. A number of special‐purpose instruments are also described, including the Genzel interferometer. All these instruments must be equipped with beamsplitters that are configured for far‐infrared operation. Poly(ethylene terephthalate), also known as Mylar or Melinex, is the most common material used to fabricate far‐infrared beamsplitters but other materials have better efficiency. These include solid silicon or silicon that has been vapor‐deposited onto Mylar.
Diode Laser Spectrometers for Mid‐Infrared Spectroscopy
Authors: Mantz Arlan W.
Published: September 2006

The sections in this article are

Introduction

The Source

The Optical System

Line Intensity and Line Shape Measurements

Tunable Diode Laser Line Shape

Absorption Line Profile

A Brief Summary of Some Novel Applications of Tunable Diode Lasers
Synchrotron and Free Electron Laser Sources of Infrared Radiation
Authors: Williams G.P.
Published: September 2006

In this article, we describe the infrared sources that are based on electron accelerators. Such sources have novel properties that allow them access to unique applications, which are complementary to those with laboratory‐based sources. Specifically, accelerator‐based sources are extremely bright, and are pulsed. Synchrotrons are broadband sources that are up to 1000 times brighter than black body sources and with pulses that are of order 100 ps long. Free electron laser sources are 6–10 orders of magnitude brighter than synchrotron radiation sources, but are narrow band. The pulse lengths are sub‐picosecond. Both sources have pulse repetition frequencies of around 100 MHz. This article explains concepts of brightness and how these sources fit into the menu of available sources for vibrational spectroscopy.
Instrumentation and Methods for High‐Resolution Gas‐Phase Spectroscopy
Authors: McNaughton Don
Published: September 2006

The sections in this article are

Introduction

Fourier Transform Infrared Spectroscopy

Optical Considerations

Instrument Line Shape and Resolution

Aperture and Resolution

Other Optical Components

Data Handling

Laser Techniques

Coupling of Equipment to High‐Resolution Spectrometers

Signal‐to‐Noise Ratio

Spectral Simplification

Computer Manipulation

Specialist Techniques and Instruments

Sub‐Doppler Spectroscopy

Field Instruments
Monochromators for Near‐Infrared Spectroscopy
Authors: DeThomas Frank A. , Brimmer Paul J.
Published: September 2006

The sections in this article are

Introduction

Diffraction Gratings

Monochromator Components

Concave Holographic Gratings

Grating Drive

Sources

Entrance and Exit Slits

Wavelength, Order and Interference Filters

Detection

Design Considerations

Stray Light

Sample Absorptivity

Spectral Resolution

Pre‐Post‐Dispersive Monochromators

Designing with Fiber Optics

Standardization of Spectra

Conclusions
Hadamard Transform Near‐Infrared Spectrometers
Authors: Hammaker Robert M. , DeVerse Richard A. , Asunskis Daniel J. , Fateley William G.
Published: September 2006

Hadamard transform (HT) spectrometry is introduced using a 3‐resolution element example to illustrate the operation of an HT spectrometer and its multiplex advantage leading to an improved signal‐to‐noise ratio (SNR). The Hadamard encoding mask is described and the digital micro‐mirror array (DMA) is introduced and described to demonstrate that the DMA is an attractive choice for the Hadamard encoding mask.

A near‐infrared DMA spectrometer and some of its features are described and its SNR advantage relative to a classical scanning dispersive spectrometer is demonstrated experimentally. The potential for the combination of the DMA with a single‐element

detector to provide an important advancement in spectroscopic instrumentation is indicated.
Near‐Infrared Array Spectrometers
Authors: Stark Edward W.
Published: September 2006

Diode‐array spectrometers have become well established for use in the near‐infrared (NIR) spectral region, particularly with fiber‐optic probes. This article discusses the advantages of array spectrometers, specifically, photometric performance, measurement speed, wavelength resolution, stability and accuracy, environmental ruggedness, and reduced cost. The spectral signal, optical throughput, noise sources, and resolution and the spectral response performance parameters of array spectrometer systems are described.

The properties of diffraction grating polychromators are discussed in detail starting with diffraction grating principles, spectral resolution, and throughput. Stray radiant energy, absorbance linearity, and dynamic range are considered. Specific grating related issues, including multiple diffraction orders, grating efficiency, and Wood’s anomalies, are defined. The properties of the concave holographic grating and its unique geometry are described.

Array detectors for NIR spectroscopy have different requirements than those for Raman spectroscopy due to the larger optical signal and dynamic range typical of NIR transmittance and reflectance measurements. The principles of photon detectors, the operational theory of photodiodes, particularly InGaAs, and the responsivity of various NIR detectors are reviewed. Resistive and capacitive transimpedance preamplifier circuits are compared, with an emphasis on dynamic range and signal amplitude resolution.

Discussion of the sources of visible and NIR array spectroscopy completes the review of the principle elements of an array spectrometer system. The spectral radiance of tungsten‐halogen lamps and its temperature sensitivity are described, as are the halogen cycle and the issues of lamp life and failure modes. Finally, deuterium arc lamps and xenon arc and flash lamps are discussed in brief.
Volume Phase Holographic Optical Elements
Authors: Owen H.
Published: September 2006

The sections in this article are

Introduction

Background

Holographic Materials and Fabrication Process

Film Preparation

Laser Exposure

Chemical Processing

Drying and Sealing

Physical and Optical Properties

Holographic Notch Filters

Background

Operating Characteristics

Optical Characteristics

Polarization Properties

Laser Bandpass Filters

Description

Volume Phase Holographic Gratings
Continuous Lasers for
R
aman Spectrometry
Authors: Pan Ming‐Wei , Benner Robert E. , Smith Lee M.
Published: September 2006

There are many different factors to consider when determining the appropriate excitation laser source for continuous wave Raman experiments. The laser characteristics of interest for designing a Raman system fall into two categories. The first category includes parameters associated with the laser output, such as wavelength, linewidth, output power, polarization, and beam quality. The second category includes physical characteristics of the laser system, such as size, reliability, and power consumption. The different characteristics of gas, dye, solid‐state, and semiconductor lasers are discussed. Comparisons of individual lasers for Raman applications illustrate some of the tradeoffs associated with the various laser parameters, and also provide an indication of the signal levels that can be expected in continuous wave Raman measurements from different kinds of materials.
F
ourier Transform Near‐Infrared
R
aman Spectroscopy
Authors: Chase Bruce
Published: September 2006

The sections in this article are

Introduction

Nature of Noise

Lasers

Collection and Filtering

Interferometers

Detectors

Standard Operations
Ultraviolet
R
aman Spectrometry
Authors: Asher Sanford A.
Published: September 2006

The sections in this article are

Introduction

Phenomenology

Instrumentation

Fundamental Applications

Analytical Applications

Biological Ultraviolet‐
R
aman Studies

Conclusions

Acknowledgments
Inverse
R
aman Spectrometry
Authors: Bermejo Dionisio
Published: September 2006

The sections in this article are

Introduction

Experimental

Quasi‐

CW

SRS

Spectrometer

Probe Laser

Pump Laser

Data Acquisition and Calibration

Applications

Diatomic Molecules

Nitrogen

Oxygen

Hydrogen and Deuterium

Fluorine and Chlorine

Carbon and Nitrogen Monoxides

Linear Molecules

Carbon Dioxide

Acetylene

Other Linear Molecules

Spherical Top Molecules

Methane

Other Spherical Top Molecules

Symmetric Top Molecules

Asymmetric Top Molecules

Photoacoustic

SRS

Acknowledgements
Trichroic Infrared Measurements of Orientation
Authors: Koenig Jack L.
Published: September 2006

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

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

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

The sections in this article are

Introduction

Electromagnetic Mechanism of Surface‐EnhancedRaman Spectroscopy for Isolated Metal Particles

A simple Model: Quasistatic Treatment of an Isolated Sphere

Electrostatics of Isolated Spheroids

Improvements to the Spheroid Model

Electrodynamic Corrections

Size‐Dependent Dielectric Constants

Current Status of Theory/Experiment Comparisons

Extensions of the Electromagnetic Model

Effect of Adsorbed Layers on Intensities

Nonlinear Surface Optical Processes

Electromagnetic Mechanism for Many Coupled Particles and for Gratings

Conclusions and Further Work

Acknowledgments
Inelastic Electron Tunneling Spectroscopy
Authors: Hipps K.W. , Mazur U.
Published: September 2006

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

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

Inelastic 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

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

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

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 Near‐Infrared Spectrometry
Authors: Choquette Steven J. , Travis John C. , Zhu Changjiang , Duewer David L.
Published: September 2006

The sections in this article are

Introduction

Water Vapor

Gas Standards

Polystyrene

Other Organics

Rare Earth Oxides

Acknowledgments