Metals experimental studies

The case of triangular lattice is particularly interesting since it corresponds to adsorption on graphite and on the (111) plane of several fee metal crystals [15,102,103,135]. The distance between adjacent potential minima for the graphite basal plane is equal to 2.46A and hence is too small to allow for their mutual occupation by even very small atoms of light noble gases. The same is true for adsorption on metals. Experimental studies have demonstrated that for rare gas atoms and simple molecules adsorbed on the graphite basal plane as well as on the (111) faces of fee crystals the ordered state corresponds to either the /3 X %/3 [102] or to the 2x2 phase [103,136,137] shown in Fig. 8. 

Kappes M M 1988 Experimental studies of gas-phase main-group metal olusters Chem. Rev. 88 369... 

Sihcate solutions of equivalent composition may exhibit different physical properties and chemical reactivities because of differences in the distributions of polymer sihcate species. This effect is keenly observed in commercial alkah sihcate solutions with compositions that he in the metastable region near the solubihty limit of amorphous sihca. Experimental studies have shown that the precipitation boundaries of sodium sihcate solutions expand as a function of time, depending on the concentration of metal salts (29,58). Apparently, the high viscosity of concentrated alkah sihcate solutions contributes to the slow approach to equihbrium. 

The product is equal to the equilibrium constant X for the reaction shown in equation 30. It is generally considered that a salt is soluble if > 1. Thus sequestration or solubilization of moderate amounts of metal ion usually becomes practical as X. approaches or exceeds one. For smaller values of X the cost of the requited amount of chelating agent may be prohibitive. However, the dilution effect may allow economical sequestration, or solubilization of small amounts of deposits, at X values considerably less than one. In practical appHcations, calculations based on concentration equihbrium constants can be used as a guide for experimental studies that are usually necessary to determine the actual behavior of particular systems. 

Hollow carbon nanotubes (CNTs) can be used to generate nearly onedimensional nanostrutures by filling the inner cavity with selected materials. Capillarity forces can be used to introduce liquids into the nanometric systems. Here, we describe experimental studies of capillarity filling in CNTs using metal salts and oxides. The filling process involves, first a CNT-opening steps by oxidation secondly the tubes are immersed into different molten substance. The capillarity-introduced materials are subsequently transformed into metals or oxides by a thermal treatment. In particular, we have observed a size dependence of capillarity forces in CNTs. The described experiments show the present capacities and potentialities of filled CNTs for fabrication of novel nanostructured materials. 

In the last decade two-dimensional (2D) layers at surfaces have become an interesting field of research [13-27]. Many experimental studies of molecular adsorption have been done on metals [28-40], graphite [41-46], and other substrates [47-58]. The adsorbate particles experience intermolecular forces as well as forces due to the surface. The structure of the adsorbate is determined by the interplay of these forces as well as by the coverage (density of the adsorbate) and the temperature and pressure of the system. In consequence a variety of superstructures on the surfaces have been found experimentally [47-58], a typical example being the a/3 x a/3- structure of adsorbates on a graphite structure (see Fig. 1). 

Galante, J. and Rostoker, W., Corrosion Related Failures in Metallic Implants and Experimental Study , Clinical Orthopaedics and Related Research, 86, 237-244 (1972)... 

In this article we critically review most of the literature concerning non-catalyzed, proton-catalyzed and metal-catalyzed polyesterifications. Kinetic data relate both to model esterifications and polyeste-rificatiom. Using our own results we analyze the experimental studies, kinetic results and mechanisms which have been reported until now. In the case of Ti(OBu)f catalyzed reactions we show that most results were obtained under experimental conditions which modify the nature of the catalyst. In fact, the true nature of active sites in the case of metal catalysts remains largely unknown. 

The behavior of plastic structures under compression plays a critical role in numerous applications. It has been recognized that the buckling of metals under elevated temperatures presents important distinctions from the classical Eulerian case, [11]. During an experimental study, [12], buckling times were registered for a range of compressive loads applied to the top of compression molded and annealed thermoplastic samples (see Fig. 2). A typical time - load dependence is shown in Fig. 3. 

Bolognesi C, Landini E, Roggieri P, Fabbri R, Viarengo A. 1999. Genotoxicity biomarkers in the assessment of heavy metal effects in mussels experimental studies. Environ Mol Mutagen 33 287-292. 

In Fig. 1.59 the relationship between temperature and concentration of elements (Zn, Ba) at constant Cl concentration which is equal to that of seawater obtained by the experimental studies and analytical data on natural hydrothermal solution (geothermal water) are shown. It is seen that the concentrations of base-metal elements (Zn, Fe, Mn, Cu, Pb) and Ba increase with increasing of temperature. Concentrations of these... 

The above results demonstrate that computational screening is promising technique for use in electrocatalyst searches. The screening procedure can be viewed as a general, systematic, DFT-based method of incorporating both activity and stability criteria into the search for new metal alloy electrocatalysts. By suggesting plausible candidates for further experimental study, the method can, ultimately, result in faster and less expensive discovery of new catalysts for electrochemical processes. 

Zellner MB, Goda AM, Skoplyak O, Barteau MA, Chen JG. 2005. Trends in the adsorption and decomposition of hydrogen and ethylene on monolayer metal films A combined DFT and experimental study. Surf Sci 583 281-296. 

The experimental studies of the surface properties of monocrystals of oxides of various metals recently conducted at well-controlled conditions [32, 210] enable one to proceed with detailed analysis of separate effects of various factors on characteristics of semiconductor gas sensors. In this direction numerous interesting results have been obtained regarding the fact of various electrophysical characteristics of monocrystalline adsorbents on the value of adsorption-related response. Among these characteristics there are crystallographic orientation of facets [211], availability of structural defects, the disorder in stoichiometry [32], application of metal additives, etc. These results are very useful while manufacturing sensors for specific gases with required characteristics. 

It is well known that the energy profiles of Compton scattered X-rays in solids provide a lot of important information about the electronic structures [1], The application of the Compton scattering method to high pressure has attracted a lot of attention since the extremely intense X-rays was obtained from a synchrotron radiation (SR) source. Lithium with three electrons per atom (one conduction electron and two core electrons) is the most elementary metal available for both theoretical and experimental studies. Until now there have been a lot of works not only at ambient pressure but also at high pressure because its electronic state is approximated by free electron model (FEM) [2, 3]. In the present work we report the result of the measurement of the Compton profile of Li at high pressure and pressure dependence of the Fermi momentum by using SR. 

Before our work [39], only one catalytic mechanism for zinc dependent HDACs has been proposed in the literature, which was originated from the crystallographic study of HDLP [47], a histone-deacetylase-like protein that is widely used as a model for class-I HDACs. In the enzyme active site, the catalytic metal zinc is penta-coordinated by two asp residues, one histidine residues as well as the inhibitor [47], Based on their crystal structures, Finnin et al. [47] postulated a catalytic mechanism for HDACs in which the first reaction step is analogous to the hydroxide mechanism for zinc proteases zinc-bound water is a nucleophile and Zn2+ is five-fold coordinated during the reaction process. However, recent experimental studies by Kapustin et al. suggested that the transition state of HDACs may not be analogous to zinc-proteases [48], which cast some doubts on this mechanism. 

Some of the earliest experimental studies of neutral transition metal atom reactions in the gas phase focused on reactions with oxidants (OX = O2, NO, N2O, SO2, etc.), using beam-gas,52,53 crossed molecular beam,54,55 and flow-tube techniques.56 A few reactions with halides were also studied. Some of these studies were able to obtain product rovibrational state distributions that could be fairly well simulated using various statistical theories,52,54,55 while others focused on the spectroscopy of the MO products.53 Subsequently, rate constants and activation energies for reactions of nearly all the transition metals and all the lanthanides with various oxidant molecules... 

General data on fire hazards present in industrial oxygen-producing plants are given with details of experimental study of factors involved in combustion of various metals and alloys used in such plant. Safety in selection of materials is discussed [1]. A study of combustion of structural metals (Fe, Al) in oxygen is given [2], See Oxygen (Liquid) Metals... 

Experimental Studies of the Reactions of Atomic Metal Ions with Hydrocarbons... 

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