Experimental Techniques and Data Analysis

3 Crazing Incidence X-ray Methods for Near-surface Structural Studies 215 

2 Crazing Incidence Asymmetric Bragg (CIAB) Diffraction 

Macrostrain is often observed in modified surfaces such as deposited thin films or corrosion layers. This results from compressive or tensile stress in the plane of the sample surface and causes shifts in diffraction peak positions. Such stresses can easily be analyzed by standard techniques if the surface layer is thick enough to detect a few diffraction peaks at high angles of incidence. If the film is too thin these techniques cannot be used and analysis can only be performed by assuming an un- 

Strained set of lattice parameters and calculating the stress from the peak shifts, taking into account the angle of the detected sets of planes relative to the surface (see discussion above). If the assumed unstrained lattice parameters are incorrect not all peaks will give the same values. It should be borne in mind that, because of stoichiometry or impurity effects, modified surface films often have unstrained lattice parameters that are different from the same materials in the bulk form. In addition, thin film mechanical properties (Young s modulus and Poisson ratio) can differ from those of bulk materials. Where pronounced texture and stress are present simultaneously analysis can be particularly difficult. 

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This work presented here covers the basic experimental techniques and data analysis procedures together with the analysis of the contribution of intracrystalline diffusion to the performance of AP catalysts. 

Several experimental techniques and data analysis methods can be employed to study the nucleation/growth kinetics and CSD in batch crystallizers. 

It is evident that difficulties in the experimental techniques and data analysis will not hinder the explosive progress of 13 C nmr studies of biopolymers. 

In the present study, Hietanen and Sillen provide convincing evidence for the formation of complexes containing one and tw o coordinated hydroxides. By using additional information on the equihbrium constants for the mononuclear hydroxide complexes of Th(IV) they suggest that the complexes formed are binuclear, that is Th2(OH) and Th lOH) ". The equihbrium constants for these complexes at 25°C are logic A 2 = -(2-8 + 0.2) and logi X2 = (5 02 + 0.04) in 0.5 M ThCh log,o / , 2 = -(2.9+ 0.2) and log,o X2 = -(5.09 + 0.04) in 0.7 M ThCL, + 2.2 M NaCl. The experimental technique and data analysis are described in detail. It is not possible to extrapolate the equilibrium constants to zero ionic strength and therefore no constants have been selected by this review. 

X-ray absorption spectroscopy is an important part of the armory of techniques for examining pure and applied problems in surface physics and chemistry. The basic physical principles are well understood, and the experimental methods and data analysis have advanced to sophisticated levels, allowing difficult problems to be solved. For some scientists the inconvenience of having to visit synchrotron radia-... 

The study of repetitive sequences utilizes many relatively routine techniques in molecular genetics that are described in a number of excellent manuals3445 and are not discussed here. Instead, we consider the aspects of experimental design and data analysis that are specific for the study of repeated DNA families. 

The following section contains a more detailed treatment of the theory behind the nonresonant spectroscopy of liquids. This will be followed by a description of the experimental implementation and data analysis techniques for a common OKE scheme, optical-heterodyne-detected Raman-induced Kerr-effect spectroscopy (22). We will then discuss the application of this technique to the study of the temperature-dependent dynamics of simple liquids composed of symmetric-top molecules. 

Fortunately, various chemometric-based techniques, including multivariate experimental design and data analysis techniques, have been devised to aid in optimizing the performance of systems and extend their separation capabilities. In broadest terms, chemometrics is a subdiscipline of analytical chemistry that uses mathematical, statistical, and formal logic to (10) ... 

We are chemists, not statisticians, and perhaps tbis differentiates our book from most others with similar content. Although we do not believe it is possible to learn the techniques of experimental design and data analysis without some knowledge of basic statistics, in this book we try to keep its discussion at the minimum necessary — and soon go on to what... 

This handbook is designed to provide general information on basic principles of TA and a variety of applications. It consists of the following three parts Part I deals with information on transition, reaction and characteristic parameters of substances. It introduces general principles, data treatment, experimental procedure and data analysis, Part II describes about 1000 typical thermal analysis curves with brief explanations of various materials, such as polymers, minerals, explosives, foods, inorganic compounds, and application of simultaneous techniques for those same substances. It also includes TA charts which have mainly been contributed by institutes and universities in China. 

The normal distribution has the familiar symmetrical beU shape as shown in Fig. 1 and is the basis for the most common statistical techniques of experimental design and data analysis. The characteristics of this distribution are described in the section on Terminology. Mass loss, mass gain, thickness loss, corrosion potential, corrosion rate, and pitting area may have a normal distribution. Although this may not be an established fact, in the past many researchers have assumed normal distributions for such data with apparent success. 

Corrosion researchers can gain a greater degree of confidence in their experimental results if they have a basic understanding and use statistical techniques of experimental design and data analysis. Statisticians cannot property design... 

Hence, the value of o may be computed. A detailed discussion of the SANS technique is beyond the scope of the present review, and details of the experimental protocol and data analysis have been reviewed previously [35]. Although unperturbed dimensions from SANS studies on melts are still very... 

Contact angle measurement is commonly used to characterize a surface and to study various wetting and de-wetting phenomena While the measurement is simple, the interpretation is not. This point has been noted by many surface investigators in the past, e.g.. Pease in 1945 [25], Morra et al. [26] in 1990, Kwok and Neumann [27] in 1999 and more recently by Marmur [28] as well as Strobel and Lyons [29]. Prior to data interpretation, one has to make sure that the measurement apparatus and procedures are impeccable. Over the years, many have voiced concerns over surface preparation and conditioning, measuranent procedure and technique, and data analysis [26,30-35]. It is therefore imperative for the community to have a set of common measurement protocol or guideline, so that inter laboratory data can be compared. Discrepancy in conclusion can be rationalized without concerns of experimental setups or procedures. 

Table 1 summarizes several of the experimental methods discussed in this chapter. A need exists for new or revised methods for transport experimentation, particularly for therapeutic proteins or peptides in polymeric systems. An important criterion for the new or revised methods includes in situ sampling using micro techniques which simultaneously sample, separate, and analyze the sample. For example, capillary zone electrophoresis provides a micro technique with high separation resolution and the potential to measure the mobilities and diffusion coefficients of the diffusant in the presence of a polymer. Combining the separation and analytical components adds considerable power and versatility to the method. In addition, up-to-date separation instrumentation is computer-driven, so that methods development is optimized, data are acquired according to a predetermined program, and data analysis is facilitated. 

Quantitative fluorescence imaging techniques and FLIM in particular are becoming increasingly important in biological and biomedical sciences. Knowledge of instrumentation and data analysis is required to avoid misinterpretation of the experimental results and to exploit the wealth of information provided by these techniques. 

The contributions to this volume demonstrate that structural studies of fibrous /1-proteins, as well as prion and amyloid fibrils, have advanced rapidly thanks in large part to improved experimental techniques and better theoretical analysis of the ever-increasing structural data. It is also possible to learn from studies of naturally occurring silks (Dicko et al., this volume) howvariations in the conditions of production of silk threads from the same protein can produce a variety of /1-structures with very distinct... 

As vitally important as the capabilities for experimental planning, screening, and data analysis are the procedures for preparation of inorganic catalysts. In contrast to the procedures usually applied in conventional catalyst synthesis, the synthetic techniques have to be adapted to the number of catalysts required in the screening process. Catalyst production can become a bottleneck and it is therefore necessary to ensure that HTE- and CombiChem-capable synthesis technologies are applied to ensure a seamless workflow. 

Experimentally, temperature is used to systematically vary the RNA structure. When a short laser pulse is used to produce a rapid temperature increase in the sample, the structural changes that ensue can be followed in real time. In this contribution, we discuss experimental methods including sample preparation, instrumentation, and data analysis. We conclude with several experimental examples that highlight usefulness of the technique. 

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