Ultra experimental techniques

The conformation of polymer chains in an ultra-thin film has been an attractive subject in the field of polymer physics. The chain conformation has been extensively discussed theoretically and experimentally [6-11] however, the experimental technique to study an ultra-thin film is limited because it is difficult to obtain a signal from a specimen due to the low sample volume. The conformation of polymer chains in an ultra-thin film has been examined by small angle neutron scattering (SANS), and contradictory results have been reported. With decreasing film thickness, the radius of gyration, Rg, parallel to the film plane increases when the thickness is less than the unperturbed chain dimension in the bulk state [12-14]. On the other hand, Jones et al. reported that a polystyrene chain in an ultra-thin film takes a Gaussian conformation with a similar in-plane Rg to that in the bulk state [15, 16]. 

Q. Williams and R. Jeanloz, Ultra-high-pressure experimental technique, in Molten Salt Techniques, Vol. 4, R. G. Gale and D. G. Lovering, eds., Plenum Kess, New York, 1991, p. 193. 

Structural information at the molecular level can be extracted using a number of experimental techniques which include, but are not restricted to, optical rotation, infra-red and ultra-violet spectroscopy, nuclear magnetic resonance in the solid state and in solution, diffraction using electrons, neutrons or x-rays. Not all of them, however, are capable of yielding structural details to the same desirable extent. By far, experience shows that x-ray fiber diffraction (2), in conjunction with computer model building, is the most powerful tool which enables to establish the spatial arrangement of atoms in polymer molecules. 

In this section we apply the theory developed in the preceding sections to a series of experiments carried out by Schmitt et al using the so-called reaction microscope for ultra-low energy electrons emitted from neutral target atoms. This state of the art experimental technique has enabled experimentalists to measure simultaneously the momenta of the emitted electrons and the recoiling residual-target ion and many new striking features have been found. 

There is clearly further debate among those who carry out the different ultra-rapid experimental techniques as to whether the risks of an anaesthetic, in a relatively young person without any invasive procedure being performed, are actually greater than those where very high doses of oral sedatives are managed by a psychiatrist, with no conclusion on that really possible. 

In the present chapter, we describe how molecules respond to an ultra-short intense laser held by referring to our recent series of studies. In Sect. 1.2, we describe the experimental techniques - such as mass-resolved momentum imaging (MRMI) and coincidence momentum imaging (CMI) - that have been developed in order to measure the momentum distributions of fragment ions generated by the Coulomb explosions of molecules in intense laser helds. In Sect. 1.3, we show how the dynamics induced within CS2 by ultra-short intense laser helds is elucidated by the CMI method from momentum... 

The Frumkin epoch in electrochemistry [i-iii] commemorates the interplay of electrochemical kinetics and equilibrium interfacial phenomena. The most famous findings are the - Frumkin adsorption isotherm (1925) Frumkin s slow discharge theory (1933, see also - Frumkin correction), the rotating ring disk electrode (1959), and various aspects of surface thermodynamics related to the notion of the point of zero charge. His contributions to the theory of polarographic maxima, kinetics of multi-step electrode reactions, and corrosion science are also well-known. An important feature of the Frumkin school was the development of numerous original experimental techniques for certain problems. The Frumkin school also pioneered the experimental style of ultra-pure conditions in electrochemical experiments [i]. A list of publications of Frumkin until 1965 is available in [iv], and later publications are listed in [ii]. 

In this work, microscale evaporation heat transfer and capillary phenomena for ultra thin liquid film area are presented. The interface shapes of curved liquid film in rectangular minichannel and in vicinity of liquid-vapor-solid contact line are determined by a numerical solution of simplified models as derived from Navier-Stokes equations. The local heat transfer is analyzed in term of conduction through liquid layer. The data of numerical calculation of local heat transfer in rectangular channel and for rivulet evaporation are presented. The experimental techniques are described which were used to measure the local heat transfer coefficients in rectangular minichannel and thermal contact angle for rivulet evaporation. A satisfactory agreement between the theory and experiments is obtained. 

Structural studies in fused salts by means of careful and thorough high-temperature measurements of electrical conductivity, density, viscosity, and laser- Raman spectroscopy have been reviewed. Four problem areas are discussed (1) melting mechanisms of ionic compounds with large polyatomic cations, (2) salts as ultra-concentrated electrolyte solutions, (3) structural aspects and Raman spectroscopy, and (4) electrolysis of molten carbonates. The results in these areas are summarized and significant contributions to new experimental techniques for molten-salt studies are discussed.275 The physical properties and structure of molten salts have also been reviewed in terms of operational (hole, free volume, partly disordered crystal) and a priori (intermolecular potential) models.276 Electrochemistry... 

The role of cavity formation in the creep process has been elucidated by a number of experimental techniques, including density measurements (23, 43], measurements of ultrasonic velocities [34, 35], determination of elastic moduli by instmmented indentation [31], and anomalous ultra-small angle X-ray scattering (A-USAXS) [23, 46]. The results of density measurements are illustrated in Figure 13.13. The vertical axis of this figure was calculated from measured density changes in tensile or... 

There are many methods available for the measurement of surface and interfacial tensions. Details of these experimental techniques and their limitations are available in several good reviews [101-104]. Table 5 shows some of the methods that are used in petroleum recovery process research. A particular requirement of reservoir oil recovery process research is that measurements be made under actual reservoir conditions of temperature and pressure. The pendant and sessile drop methods are the most commonly nsed where high temperatur pressure conditions are required. Examples are discussed by McCaffery [i05] and DePhUippis et al. [J06]. These standard techniques can be difficult to apply to the measurement of extremely low interfacial tensions (< 1 to 10 mN/m). For ultra-low tensions two approaches are being used. For moderate temperatures and low pressures the most common method is that of the spinning drop, especially for microemulsion research [107], For elevated temperatures and pressures a captive drop method has been developed by Schramm et al. [JOS], which can measure tensions as low as 0.001 mN/m at up to 200 °C and 10,000 psi. In aU surface and interfacial tension work it should be appreciated that when solutions, rather than pure liquids, are involved appreciable changes can occur with time at the surfaces and interfaces, so that techniques capable of dynamic measurements tend to be the most useful. 

COF for oxide-based tribo-systems was observed when adding PLL-g-PEG to aqueous buffer solution. The present study is a continuation of this work, focusing on the architectural parameters of the PLL-g-PEG copolymer and its influence on the macroscopic lubrication properties. The architectural parameters investigated in this work include side-chain (PEG) length, Lys/ PEG grafting ratio and backbone (PLL) length. The experimental techniques employed are ultra-thin-film interferometry, the mini-traction machine (MTM), and pin-on-disk tribometry. 

Vibrational spectroscopic studies of heterogeneously catalyzed reactions refer to experiments with low area metals in ultra high vacuum (UHV) as well as experiments with high area, supported metal oxides over wide ranges of pressure, temperature and composition [1]. There is clearly a need for this experimental diversity. UHV studies lead to a better understanding of the fundamental structure and chemistry of the surface-adsorbate system. Supported metals and metal oxides are utilized in a variety of reactions. Their study leads to a better understanding of the chemistry, kinetics and mechanisms in the reaction. Unfortunately, the most widely used technique for determining adsorbate molecular structure in UHV,... 

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