bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chemometric Methods in Process Analysis
Authors: Booksh Karl S. 
Published: September 2006

AbstractChemometrics may be loosely defined as the development and application of mathematical and statistical techniques to aid in the analysis of chemical data. The goal of chemometrics is to guide the chemist in the optimum extraction of chemically relevant information from a series of complex chemically oriented observations. To this end, this article addresses a wide array of chemometric tools that are applicable to industrial process analysis. The three main sections present statistical and mathematical tools in the context of univariate, multivariate, and multiway analyses. Each of the three sections discusses the benefits and limitations of qualitative analysis, quantitative analysis, and process monitoring with the class of data in question. Additional sections address the appropriate pretreatment of collected data to aid in efficient analysis and validation of the derived chemometric models. In these sections methods for background correction and instrument standardization are discussed.
Nuclear Magnetic Resonance and Magnetic Resonance Imaging for Process Analysis
Authors: McCarthy Michael J. , Bobroff Serge 
Published: September 2006

AbstractNuclear magnetic resonance (NMR) spectroscopy is an experimental technique based on the interaction between nuclear magnetic moments and an applied magnetic field. The nuclei emit and absorb energy at a specific frequency that is proportional to the applied magnetic field. Magnetic resonance imaging (MRI) is the term used to describe the spatial resolution of NMR signals within a sample. NMR/MRI may provide information on the weight, chemical composition, physical properties, and structure of a sample. NMR is a noncontacting and noninvasive measurement. NMR and MRI are suitable for use in process control and have been applied to polymer processing, food processing and refinery processes. The response is linear from the detection limits of approximately 10 ppb to 100%. The accuracy of the technique depends on the signal‐to‐noise ratio (S/N), which is a function of the sample size, applied magnetic field strength, the radio‐frequency (rf) coil and the spectrometer hardware. Typical accuracy of the technique is 0.5% for measurements of composition and 1–5% for viscosity. NMR cannot generally be applied to magnetic or highly conductive materials.
Pulp and Paper Matrices Analysis: Introduction
Authors: Sitholé B. Bruce 
Published: September 2006

Abstract
The pulp and paper industry is a major player in the economies of many developed countries. As illustrated in Figure 1(a) and (b), the developed world accounts for more than 60% of the world output in pulp, paper and paperboard capacity. In one particular case, namely Canada, the industry contributes over 15% to the trade balance (see Figure 2). In order to ensure continual survival of the industry, it is necessary to continually improve and/or optimize the utilization of raw materials, the pulping processes, the papermaking process, the product quality properties and the protection of the environment. Analytical chemistry has an important role to play in the improvement and/or optimization of these parameters. This article summarizes how and where analytical chemistry is used, or can be used, to achieve the desired goals. Applications of analytical chemistry in the pulp and industry are reviewed in detail in the rest of the articles in this section on pulp and paper.
Carbohydrates from Chemical Pulps: Characterization by Capillary Zone Electrophoresis
Authors: Ristolainen Matti , Alén Raimo 
Published: September 2006

AbstractCapillary zone electrophoresis (CZE) is one of the novel separation techniques, being applicable, for example, to virtually all important biomass‐derived monosaccharides. However, in spite of this fact the utilization of this technique in the pulp and paper industry is currently rather limited. In this chapter practical guidance and some application examples are given to show how carbohydrate material (polysaccharides, oligosaccharides, and neutral and acidic monosaccharides) in pulps and spent liquors can be analyzed by CZE. Emphasis is placed on sample preparation and separation conditions including comparison with other separation methods, such as gas chromatography (GC) and high‐performance liquid chromatography (HPLC), generally used for similar purposes. In addition, a short description of other significant degradation products (e.g. aliphatic carboxylic acids and lignin monomers) formed during delignification (e.g. cooking and bleaching) is given. It is concluded that these low‐molecular‐mass (LMM) degradation products could also be analyzed effectively by CZE.
Pulp and Paper Matrices
Authors: Douek Maurice 
Published: September 2006

Abstract
Chemical analysis plays an important role in pulp and paper research and in the day‐to‐day operation of pulp and paper mills. It is used in practically every aspect of the papermaking process, including the characterization of raw materials and products, optimization of process parameters, addressing environmental concerns, and diagnosing operation and product quality problems. This article provides an overview of the major types of chemical analyses conducted on pulp and paper matrices. The emphasis is mainly on the principle, significance, and applications of the various analyses. Major areas of application include the analysis of wood pulp, process liquids, paper, and deposits and contaminants. Analytical techniques and instrumentation range from the traditional or standard wet chemical and instrumental methods designed primarily for routine testing in mills to highly sophisticated techniques used mainly for research purposes.
Semiarid Land Assessment: Monitoring Dry Ecosystems with Remote Sensing
Authors: Hill Joachim 
Published: September 2006

AbstractSemiarid lands belong to the world's dryland environments, which are permanently, seasonally or temporarily subjected to a significant deficit in moisture availability. Drylands, or dry ecological systems, include the proper deserts as well as their semiarid and subhumid dry margins. The areas referred to range from the cold polar deserts (which, because of their highly specific nature, are not considered in this article) to warm tropical deserts surrounded by tropical semiarid and subhumid drylands, including subtropical Mediterranean latitudes.Remote sensing is the scientific approach to extracting information from an object without coming into physical contact with it. Broad definitions would need to include computer vision, astronomy, medical and biological imaging, sonar, observation of terrestrial and marine ecosystems and many other fields. Within the restricted context of this article we shall limit our perspective to collecting information about the state of terrestrial ecosystems through air‐ and space‐borne sensor systems. This process is based on the interaction of electromagnetic radiation with the surface constituents, and increasing knowledge about these interaction mechanisms makes it possible to interpret remotely sensed data with regard to specific environmental conditions and their change in time.
Imaging Spectrometry for Geological Applications
Authors: van der Meer Freek D. 
Published: September 2006

AbstractReflectance and emittance spectra have been used for many years to obtain compositional information about the Earth's surface. Electronic transition and charge transfer processes associated with transition‐metal ions such as Fe, Ti, Cr, and so on produce diagnostic absorption features in the visible and near‐infrared (VNIR) wavelength region of the spectra of minerals and rocks, while vibrational processes in H2O and OH−produce fundamental overtone absorptions in the shortwave infrared (SWIR) portion of the spectrum. Field and laboratory studies have demonstrated that reflectance spectroscopy can be used for mineral identification and further geological studies. The translation of these measurements to imaging data led to the development of the field of imaging spectrometry in remote sensing. Imaging spectrometers acquire images in a large number of narrow contiguous spectral bands to enable the extraction of reflectance spectra at a pixel scale that can be directly compared with similar spectra measured either in the field or in a laboratory. In this chapter, the use of imaging spectrometer data for geological applications is discussed by describing the processing chain of data analysis from the raw data acquisition to prospective applications. Several topics are addressed.An appraisal of future spaceborne imaging spectrometer missions and potential prospective applications provides insight into this vastly growing field of research.
Land Cover Assessment and Monitoring
Authors: Lambin Eric 
Published: September 2006

AbstractLand‐use changes are cumulatively transforming land cover at an accelerating pace, mainly in the tropics. These changes in terrestrial ecosystems are closely linked with the issue of the sustainability of socioeconomic development since they affect essential parts of our natural capital such as climate, soils, vegetation, water resources and biodiversity. Changes in terrestrial ecosystems brought about by human activity are driven by land cover conversion, land degradation, land‐use intensification or other forms of land cover modification. The term land cover refers to the attributes of a part of the Earth's land surface and immediate subsurface, including biota, soil, topography, surface and groundwater, and human structures. The term land use refers to the purposes for which humans exploit the land cover. One generally distinguishes between land cover conversion, the complete replacement of one cover type by another, and land cover modification, more subtle changes that affect the character of the land cover without changing its overall classification. Land cover modifications are generally more prevalent than land cover conversions. Two types of satellite sensors are used in land cover applications: fine spatial resolution systems and coarse spatial resolution/high temporal frequency systems. Data are collected in the visible, thermal and microwave ranges of the spectrum. Information in the spatial domain also provides valuable information on land surface attributes. These data are analyzed either for land cover mapping or for land cover monitoring. Current research is moving toward the direct estimation of biophysical surface parameters by model inversion methods. Multisensor approaches are also increasingly being developed.
Stellar Spectroscopy
Authors: Porter John M. , Steele Iain A. 
Published: September 2006

Abstract
Spectroscopy started with the examination of the Sun's light, making stellar spectroscopy the oldest branch of the subject. We describe modern stellar spectroscopy, and highlight some of the major successes in understanding the light output from stars and what we can deduce about the underlying objects. We present a description of stellar atmospheres considering the mechanical structure and the transport of energy. This leads on to a discussion of how the continuum and spectral lines of stellar spectra are formed and an explanation of the main features observed. The spectral lines observed in stellar spectra are then discussed and the information which can be obtained from examining their line shapes is examined. These include atmospheric pressure and temperature and both coherent and turbulent velocity fields (from stellar rotation and atmospheric convection currents). Magnetic fields, if large enough, may also be detected from careful examination of spectral lines.
Following a discussion of some practical aspects of observing stars, the main observational stellar classification scheme is presented, along with its interpretation regarding the underlying mass, radius, temperatures and evolutionary phase of the star. The effect of the chemical composition on line strengths is discussed, along with observational techniques of measuring it. The information which is obtained from different wavelength regimes – from radio waves to γ‐rays – is presented, along with possible difficulties associated with observing in each regime.
Finally, we discuss what we have learnt from examination of stellar spectra and the current state of theory which is applied to them.
Nuclear Magnetic Resonance in Metals Analysis
Authors: Neue Günther 
Published: September 2006

Abstract

Nuclear magnetic resonance (NMR) is a spectroscopic technique which uses the magnetic component (

B

1
) of radiofrequency (RF) electromagnetic fields to excite nuclear spins which are subject to a static magnetic field (

B

0
). The resonance frequency is proportional to this field. Most stable elements possess at least one isotope with spin I > 0 and, hence, are observable by NMR. Magnetic field gradients make it possible to label spatial coordinates within a sample. Magnetic resonance imaging (MRI) uses this principle to reconstruct images from NMR signals. Skin effect enhanced imaging nuclear magnetic resonance (SEEING‐NMR) derives its submicrometer resolution from the strong shielding properties of metals with respect to RF fields. Resonance frequencies of most isotopes are well separated from each other, making NMR an element‐specific technique. Interactions of spins with their local environment lead to characteristic spectral changes that reflect the chemical state, the physical state or local geometry. The possibility of coherent manipulation and detection of spin states allows for an extreme flexibility in designing new and highly selective NMR experiments. Integrated signal intensities are strictly proportional to concentrations. The disadvantage of NMR is the small signal‐to‐noise ratio, especially for nuclei that have low resonance frequencies. Except for sensitive isotopes like
1
H or
19
F, concentrations should therefore be higher than 1% and samples weighing 10 to 100 mg are recommended. The sensitivity to local interactions often makes it impossible to predict the visibility of NMR signals in unknown substances.
Differential Reflectance Spectroscopy in Analysis of Surfaces
Authors: Hummel R.E. 
Published: September 2006

AbstractDifferential reflectance spectroscopy (DRS) is a surface analytical technique. It uses ultraviolet (UV), visible, or infrared (IR) light as a probing medium. The interaction of light with “strongly absorbing materials”, such as metals, alloys, semiconductors, etc. occurs in the first 10–20 nm. Thus the differential reflectometer probes 50–100 atomic layers into nontransparent solid surfaces. Because of the specific probing depth of light, DRS fills the gap between other surface techniques such as ion‐scattering, Auger spectroscopy, and ESCA (electron spectroscopy for chemical analysis), which probe 1, 5, or even 20 monolayers, and X‐ray diffraction (XRD) which probes as deep as 1–50 µm into a bulk material. The information gained by DRS is somewhat different from that obtained by the other surface techniques mentioned. A “differential reflectogram” reveals details about the electron structure around the Fermi surface. Specifically, the instrument allows the exact measurement of the energies which electrons absorb from photons as they are raised into a higher, allowed energy states. Since each material has a specific electron‐band structure the measurement of the characteristic energies for electron “interband transitions” serves as a means for identifying these materials. Furthermore, investigation of any shift of these characteristic energies, which may be caused by the addition of solute elements to a solvent, by transformations, lattice defects, ordering, or the like, provides a deeper insight into the nature of the solid state. The application of DRS is, of course, not restricted to strongly absorbing materials such as metals, alloys, or semiconductors. Its strength has likewise been demonstrated in the identification and characterization of transparent or semitransparent surface layers as observed in thin‐film corrosion products on metal substrates. DRS is used to scan two samples whose properties differ slightly. Thus, the main advantage of DRS over conventional optical techniques lies in its ability to eliminate any undesirable influences of oxides, windows, electrolytes, instrumental variations, and the like, owing to the differential nature of the technique. No vacuum is needed unless measurements in the vacuum UV are desired. Thus, the formation of a surface layer due to environmental interactions can be studied in situ. The measurements are fast: a complete differential reflectogram, that is, an automatic scan from the UV through the visible into the IR region, is accomplished in about 3 min.
Electron Microscopy and Scanning Microanalysis
Authors: Oleshko Vladimir , Gijbels Renaat , Amelinckx Severin 
Published: September 2006

Abstract
In analytical electron microscopy (AEM), several imaging, diffraction and analytical modes are integrated in a design to provide analytical synergism having obvious advantages over any single instrument. The subject of AEM is to determine the morphology, crystallinity, defect structure, phase and elemental compositions and electronic properties of a material using the focused electron beam and signals generated in the course of its interaction with the specimen. The article considers history and stages of development of AEM, theoretical aspects of electron beam–solid interactions, instrumentation and methodology of particular techniques and image analysis, sample preparation and some typical applications. Various electron–specimen interactions generate a great deal of structural and analytical information in the form of emitted electrons and/or photons and internally produced signals, such as elastically and inelastically scattered electrons, Auger electrons (AE), X‐rays and cathodoluminescence (CL), which can be analyzed in different operating modes. Imaging of transmitted solid materials is essentially due to elastic scattering (diffraction) of electrons by the periodic arrangement of atoms in crystals (diffraction contrast) and/or interference of several diffracted and transmitted beams (phase contrast). High‐resolution imaging in the scanning transmission mode is also possible by using incoherently scattered electrons (Z‐contrast). Inelastic interactions are forming the basis for all chemical analytical techniques (energy‐dispersive (X‐ray) spectroscopy (EDS) and wavelength‐dispersive (X‐ray) spectroscopy (WDS), electron energy‐loss spectroscopy (EELS)/energy‐filtering transmission electron microscopy (EFTEM), AE and CL spectroscopy). Basic data characterizing state‐of‐the‐art modern AEM and current trends in its development are presented.
Scanning Probe Microscopy, Industrial Applications of
Authors: Born Axel 
Published: September 2006

Abstract
Scanning probe microscopy (SPM) has developed to become an integral part of the hierarchy of analytical tools in industrial surroundings, owing to its excellent spatial resolution and its ability to work under ambient conditions. The purpose of this article is to give an insight into the potential of SPM techniques in industrial applications today. Owing to the wide variety of possible applications, this article can present only a small selection of uses.
The given examples highlight typical aspects of the current analytical work of different industrial laboratories. First, an introduction to the specific industry and its analytical obstacles is given. Second, a solution using a SPM method is demonstrated and the particular SPM method is explained in detail. Finally, an actual measurement is given for each example.
To summarize, with the necessary precautions concerning stable conditions during the measurement, SPMs are a useful tool for industrial applications which fulfill the demands of industry today. SPMs are commercially available, rapid, quantitative and reproducible. Furthermore, they are available with a user‐friendly interface. The increasing number of companies that are using SPMs in the laboratory and manufacturing every day provides evidence of the rising popularity of SPM.
Ion Scattering Spectroscopy in Analysis of Surfaces
Authors: Langley Robert A. 
Published: September 2006

Abstract
Ion scattering spectroscopy (ISS) is used to analyze materials for their atomic constituents for depths from a monolayer to many microns. The probing depth and depth resolution are mainly determined by the energy and mass of the projectile. The projectile energy ranges from several thousand to many million electron‐volts. For ISS there are many options for analysis, e.g. scattered incident projectiles, knock‐on target atoms, reactants from nuclear reactions between the projectile and target atom, and X‐rays from excitation of target atoms by the projectiles. There are also numerous experimental techniques for studying various particular material characteristics, e.g. crystal structure, crystal damage, lattice deformation, and impurity content and location. Each of these areas is addressed, as well as the equipment needed for their implementation. Review articles and books on specific relevant subjects are noted, as well as data analysis techniques and computer analysis and simulation programs.
Photoluminescence in Analysis of Surfaces and Interfaces
Authors: Gfroerer Timothy H. 
Published: September 2006

Abstract
Photoluminescence (PL) is the spontaneous emission of light from a material under optical excitation. The excitation energy and intensity are chosen to probe different regions and excitation concentrations in the sample. PL investigations can be used to characterize a variety of material parameters. PL spectroscopy provides electrical (as opposed to mechanical) characterization, and it is a selective and extremely sensitive probe of discrete electronic states. Features of the emission spectrum can be used to identify surface, interface, and impurity levels and to gauge alloy disorder and interface roughness. The intensity of the PL signal provides information on the quality of surfaces and interfaces. Under pulsed excitation, the transient PLintensity yields the lifetime of nonequilibrium interface and bulk states. Variation of the PL intensity under an applied bias can be used to map the electric field at the surface of a sample. In addition, thermally activated processes cause changes in PL intensity with temperature.
PL analysis is nondestructive. Indeed, the technique requires very little sample manipulation or environmental control. Because the sample is excited optically, electrical contacts and junctions are unnecessary and high‐resistivity materials pose no practical difficulty. In addition, time‐resolved PL can be very fast, making it useful for characterizing the most rapid processes in a material. The fundamental limitation of PL analysis is its reliance on radiative events. Materials with poor radiative efficiency, such as low‐quality indirect bandgap semiconductors, are difficult to study via ordinary PL. Similarly, identification of impurity and defect states depends on their optical activity. Although PL is a very sensitive probe of radiative levels, one must rely on secondary evidence to study states that couple weakly with light.