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Abstract: Corrosion protection of aluminum in 2 mol/L [H.sub.2]S[O.sub.4] solution is examined in the presence of ortho-substituted aniline derivatives using potentiodynamic polarization and electrochemical impedance spectroscopy measurements. Density function theory [...]

A procedure is developed for the cyclic-injection spectrophotometric determination of iron and aluminum in petroleum products; it includes microwave sample mineralization followed by the determination of analyses as their complexes with Chrome Azurol S at pH 5. The classical least-squares technique is used for the simultaneous determination of iron and aluminum. The analytical range for elements covers from 10 to 100 mg/kg at a sample weight of 1 g. The limits of detection for both elements are 3 mg/kg. The developed procedure was used for the determination of iron and aluminum in the spent engine oil and marine fuel. Keywords: cyclic-injection analysis, spectrophotometry, chemometrics, classical least-squares technique, petroleum products, iron, aluminum, Chrome Azurol S DOI: 10.1134/S1061934814120132, An important parameter of the quality of petroleum products is the concentration of metals, including aluminum and iron, that can be present in petroleum products as various inorganic and organic [...]

It was shown that polyethylene glycol molecules act as good corrosion inhibitors. Quantum chemical simulation showed the effect of molecular weight on studying polymers with repeating units 1, 2, 3, 4, and 5 and also polymers with high molecular weights with repeating units 10, 20, and 30. Using the density functional theory at the B3LYP/6-31G+(d,p) basis set level, ab initio calculations using the HF/6-31G+(d,p) and semi-empirical PM3 methods were performed on polyethylene glycol to investigate the correlation between its molecular structure and the corresponding inhibition efficiency. The calculated parameters include the highest occupied molecular orbital, the lowest unoccupied molecular orbital, the separation energy ([increment of E]), the dipole moment (/μ), the softness (σ), the fraction of electrons transferred from the inhibitor to the metal surface ([increment of N]), the electronegativity (χ), the hardness (η), and the total negative charge. Furthermore, the adsorption energies of the inhibitors with the aluminum (1 1 1) surface were studied using the molecular dynamic method. A good correlation between the theoretical data and the experimental results was found. Key words: inhibition of corrosion, aluminum, polyethylene glycol, quantum chemical parameters, molecular dynamics. Il a ete montre que les molecules de poly(ethyleneglycol) agissent comme de bons inhibiteurs de la corrosion. Des simulations de chimie quantique montrent que l'effet du poids moleculaire sur l'etude des polymeres comportant 1, 2, 3, 4 et 5 unites fondamentales ainsi que sur ceux de produits de poids moleculaires plus eleves comportant 10, 20 et 30 unites fondamentales. On a fait appel a des calculs effectues sur le poly(ethyleneglycol) a l'aide de la theorie de la fonctionnelle de la densite au niveau B3LYP/6-31G+(d,p) de la theorie, de calculs ab initio utilisant un ensemble HF/6-31G+(d,p) et a des methodes semi-empiriques PM3 pour etudier la correlation entre sa structure moleculaire et l'efficacite correspondante d'inhibition. Les parametres calcules comprennent l'orbitale moleculaire haute occupee, l'orbitale moleculaire basse vacante, l'energie de separation ([increment of E]), le moment dipolaire (/μ), la douceur (σ), la fraction d'electron transferee de l'inhibiteur a la surface metallique ([increment of N]), l'electronegativite (χ), la durete (η) et la charge negative totale. De plus, on a etudie les energies d'absorption des inhibiteurs avec la surface de l'aluminium (111) en faisant appel a la methode de la dynamique moleculaire. On a observe une bonne correlation entre les resultats experimentaux et les valeurs theoriques. [Traduit par la Redaction] Mots-cles: inhibition de la corrosion, aluminium, poly(ethyleneglycol), parametres de chimie quantique, dynamique moleculaire., Introduction Aluminum has a remarkable economic and industrial importance owing to its low cost, light weight, and high thermal and electrical conductivity. The most important feature of aluminum is its [...]

A computational approach has been undertaken to design and assess potential Fe--Cr--Ni--Al systems to produce stable nanostructured corrosion-resistant coatings that form a protective, continuous scale of alumina or chromia at elevated temperatures. The phase diagram computation was modeled using the THERMO-CALC[R] software and database (Thermo-Calc[R] Software, 2007, THERMO-CALC for Windows Version 4, Thermo-Calc Software AB, Stockhohn, Sweden; Thermo-Calc[R] Software, 2007, TCFE5, Version 5, ThermoCalc Software AB, Stockholm, Sweden) to generate pseudoternary, Fe--Cr--Ni--Al phase diagrams to help identity compositional ranges without the undesirable brittle phases. The computational modeling of the grain growth process, sintering of voids and interface toughness determination by indentation, assessed microstructural stability, and durability of the nanocoatings fabricated by a magnetron-sputtering process. Interdiffusion of Al, Cr, and Ni was performed using the DICTRA[R] diffusion code (Thermo-Calc Software[R], DICTRA, Version 24, 2007, Version 25, 2008, Thermo-Calc Software AB, Stockholm, Sweden) to maximize the long-term stability of the nanocoatings. The computational results identified a new series of Fe--Cr--Ni--Al coatings that maintain long-term stability and a fine-grained microstructure at elevated temperatures. The formation of brittle [sigma]-phase in Fe--Cr--Ni--Al alloys is suppressed for Al contents in excess of 4 wt %. The grain growth modeling indicated that the columnar-grained structure with a high percentage of low-angle grain boundaries is resistant to grain growth. Sintering modeling indicated that the initial relative density of as-processed magnetron-sputtered coatings could achieve full density after a short thermal exposure or heat-treatment. The interface toughness computation indicated that the Fe--Cr--Ni--Al nanocoatings exhibit high interface toughness in the range of 52-366 J/[m.sup.2]. The interdiffusion modeling using the DICTRA software package indicated that inward diffusion could result in substantial to moderate Al and Cr losses front the nanocoating to the substrate during long-term thermal exposures. [DOI: 10.1115/1.3204651]

Condensed octadecylphosphonic acid (OPA) dimers, i.e., two OPA molecules combined with the loss of a water molecule, were detected by time-of-flight secondary ion mass spectrometry (TOF-SIMS) on OPA self-assembled monolayers (SAMs) that are only weakly bonded on the native oxide layer of a silicon wafer. In contrast, these condensed dimers were absent on OPA SAMs formed on the oxide layer of an aluminum film, where the OPA molecules are chemically bonded on the substrate through a P--O--Al linkage. These observations lead us to conclude that the OPA molecules in their SAMs have to be free from chemical bonding with the substrate in order for the primary ion beam to generate ion fragments of the condensed dimer. We demonstrate that the detection of condensed OPA dimers serves as an analytical criterion for TOF-SIMS to reveal the bonding mode of OPA molecules in their SAMs on different oxides. 10.1021/ac100671q

The service life of tooling plays an important part in the economics of the extrusion process. A number of causes are considered responsible .for initiating damage to the dies before its designated life is reached. Apart from other factors such as die design and manufacturing, heat treatment, working conditions, etc, the performance of the die can directly be related to the billet quality used in the extrusion press. The purpose of this paper is to investigate the effect of Al-6063 billet source (primary or secondary) on extrusion die failure, based on microstructural investigation. A secondary (remelt) billet cast in-house at a local extrusion plant is compared with a primary (smelter) billet by applying different material eharacterization techniques, including optical microscopy, Vickers microhardness measurement, X-ray diffraction (XRD) analysis, and energy dispersive spectroscopy (EDS). It is observed that a secondary, billet has a comparatively coarse grain structure, nonhomogeneous distribution of secondary phases, inclusions, and high hardness that can be associated with poor casting and homogenization practice. In view of present results, some suggestions during in-house billet preparation of secondary billets have been formulated for improved die service life. [DOI: 10.1115/1.4000098] Keywords: extrusion billet, die life, microscopic study, billet quality

The formation of substitutional alloys has been restricted to elements with similar atomic radii and electronegativity. Using high-pressure at 298 K, we synthesized a face-centered cubic disordered alloy of highly dissimilar elements (large Ce and small Al atoms) by compressing the [Ce.sub.3]Al intermetallic compound > 15 GPa or the [Ce.sub.3]Al metallic glass >25 GPa. Synchrotron X-ray diffraction, Ce [L.sub.3]-edge absorption spectroscopy, and ab initio calculations revealed that the pressure-induced Kondo volume collapse and 4f electron delocalization of Ce reduced the differences between Ce and Al and brought them within the Hume-Rothery (HR) limit for substitutional alloying. The alloy remained after complete release of pressure, which was also accompanied by the transformation of Ce back to its ambient 4f electron localized state and reversal of the Kondo volume collapse, resulting in a non-HR alloy at ambient conditions. 4f electron delocalization | Ce-Al solid solution alloy | high pressure | Hume-Rothery rules | metallic glass

The reactions of metal clusters with small molecules often depend on cluster size. The selectivity of oxygen reactions with aluminum duster anions can be well described within an electronic shell model however, not all reactions are subject to the same fundamental constraints. We observed the size selectivity of aluminum duster anion reactions with water, which can be attributed to the dissociative chemisorption of water at specific surface sites. The reactivity depends on geometric rather than electronic shell structure. Identical arrangements of multiple active sites in [Al.sub.16.sup.-], [Al.sub.17.sup.-], and [Al.sub.18.sup.-] result in the production of [H.sub.2] from water.

The structure and properties of glasses and melts in the MgO-[Al.sub.2][O.sub.3]-Si[O.sub.2] (MAS) and CaO-MgO-[Al.sub.2][O.sub.3]-Si [O.sub.2] (CMAS) systems play an important role in Earth and material sciences. Aluminum has a crucial influence in these systems, and its environment is still questioned. In this paper, we present new results using Raman spectroscopy and [sup.27]Al nuclear magnetic resonance on MAS and CMAS glasses. We propose an Al/Si tetrahedral distribution in the glass network in different [Q.sub.n] species for silicon and essentially in [Q.sup.4] and [sup.V]Al for aluminum. For the CMAS glasses, an increase of [sup.V]Al and [sup.VI]Al is clearly visible as a function of the increase of Mg/Ca ratio in the [(Ca,Mg).sub.3][Al.sub.2][Si.sub.3][O.sub.12] (garnet) and (Ca,Mg)Al[Si.sub.2][O.sub.8] (anorthite) glass compositions. In the MAS system, the proportion of [sup.V]Al and [sup.VI]Al increases with decreasing Si[O.sub.2] and, similarly with calcium aluminosilicate glasses, the maximum of [sup.V]Al is located in the center of the ternary system. Keywords: Aluminosilicate, glasses, NMR, Raman

Aluminotaramite, ideally Na(CaNa)([Fe.sup.2+.sub.3][Al.sub.2]) ([Si.sub.6][Al.sub.2])[O.sub.22][(OH).sub.2], and alumino-magnesiotaramite, ideally Na(CaNa)([Mg.sub.3][Al.sub.2]) ([Si.sub.6][Al.sub.2])[O.sub.22][(OH).sub.2], occur in retrogressed eclogites in the Liset kyanite-eclogite pod, near Selje, Vestlandet, Norway. Fluoro-alumino-magnesiotaramite, ideally Na(CaNa)([Mg.sub.3][Al.sub.2]) ([Si.sub.6][Al.sub.2])[O.sub.22][F.sub.2], occurs in the Jianchang eclogite, Su-Lu coesite-eclogite province, China. These aluminotaramites always replace other higher pressure amphiboles (nyboite and fluoronyboite), and their higher Al content derives from resorbed garnets and lowered pressure during retrogression from the eclogite to the amphibolite facies. This paper reports complete mineral data for the three new holotypes as obtained by EMP analysis, structure refinement, and optical measurements. The three new minerals and mineral names have been approved with votes 2006-023, 2006-024, and 2006-025, respectively, by the IMA Commission on New Minerals, Nomenclature and Classification. Holotype aluminotaramite has the unit formula: [sup.A][([Na.sub.0.89] [K.sub.0.01).sub.[SIGMA]0.90] [sup.B][(Fe.sup.2+.sub.0.11][Na.sub.0.82][Ca.sub.1.07]).sub.[SIGMA]2.00] [sup.C][([Fe.sup.2+.sub.1.75] [Mg.sub.1.62][Al.sub.1.12][Fe.sup.3+.sub.0.42][Ti.sub.0.07][Zn.sub.0.01] [Mn.sub.0.01]).sub.[SIGMA]5.00] [sup.T][([Si.sub.6.23][Al.sub.1.77]).sub.[SIGMA]8.00][O.sub.22] [sup.W] [(O[H.sub.1.86][F.sub.0.14]).sub.[SIGMA]2.00], and a = 9.7489(5), b = 17.9377(7), c = 5.3233(3) [Angstrom], [beta] = 104.539(5)[degrees], V = 901.1(2) [[Angstrom].sup.3]; the calculated density is 3.29 g/[cm.sup.3]. Holotype alumino-magnesiotaramite has the unit formula: [sup.A] [Na.sub.1.07] [sup.B][([Fe.sup.2+.sub.0.06][Na.sub.0.73][Ca.sub.1.21]).sub.[SIGMA]2.00] [sup.C][([Fe.sup.2+.sub.1.06] [Mg.sub.2.40][Al.sub.1.20][Fe.sup.3+.sub.0.31] [Ti.sub.0.03]).sub.[SIGMA]5.00] [sup.T][([Si.sub.6.09][Al.sub.1.91]).sub.[SIGMA]8.00] [O.sub.22] [sup.W] [(OH).sub.2.00] and a = 9.7899(7), b = 17.8991(9), c = 5.3192(5) [Angstrom], [beta] = 104.900(7)[degrees], V = 900.7(3) [[Angstrom].sup.3]; the calculated density is 3.21 g/[cm.sup.3]. Holotype fluoro-alumino-magnesiotaramite has the unit formula: [sup.A] [Na.sub.0.99] [sup.B][([Fe.sup.2+.sub.0.02][Na.sub.0.77][Ca.sub.1.21]).sub.[SIGMA]2.00] [sup.C][([Fe.sup.2+.sub.1.11] [Mg.sub.2.12][Al.sub.1.04][Fe.sup.3+.sub.0.68][Ti.sub.0.03] [Mn.sub.0.02]).sub.[SIGMA]5.00] [sup.T][([Si.sub.6.00][Al.sub.2.00]).sub.[SIGMA]8.00] [O.sub.22] [sup.W][([F.sub.1.04]O[H.sub.0.96]).sub.2.00], and a = 9.7414(8), b = 17.9095(13), c = 5.3335(4) [Angstrom], [beta] = 104.672(1)[degrees], V = 900.2(3) [[Angstrom].sup.3]; the calculated density is 3.26 g/[cm.sup.3]. Keywords: Aluminotaramite, alumino-magnesiotaramite, fluoro-alumino-magnesiotaramite

The role of (Al, Si) disorder in the kinetics of albite dissolution is explored through parameterized Monte Carlo methods. Two dissolution mechanisms--multilayer leaching and single-layer retreat--were tested on 48 albite test configurations. In simulations involving multilayer leaching, dissolution rates increased with decreasing long-range order (LRO). We observed a fivefold maximum increase in dissolution rate tied to (Al, Si) disordering, roughly equivalent to that accompanying a decrease of 1.4 pH units at pH 1-5. This increase in rate due to disordering in albite is similar to that observed from compositional variation in plagioclase feldspars ([An.sub.47] vs. [An.sub.0]) at low pH. In contrast, (Al, Si) disordering had no discernible effect during the simulations involving the single-layer retreat mechanism. These results suggest that the effect of (Al,Si) disorder on albite dissolution rate is mechanism-dependent. Keywords: Long-range order, short-range order, disorder, albite, Monte Carlo, dissolution mechanism, kinetics

A newly developed theory concerning the transport of sputtered particles from the cathode to the growing film, to analyze the experimentally determined deposition rate of various elements in the plasma-assisted sputter deposition technique is reported. The method helped to analyze the argon pressure dependence of the deposition rate of aluminum, silicon, vanadium, chromium, germanium, tantalum and tungsten under several different experimental conditions.

The third harmonic generation technique is employed to explain the results of the third order nonlinear optical susceptibilities of various doped and undoped zinc oxide films. The results show that the conversion of the third harmonic signal at different dopants and at an appropriate concentration takes place due to the high conductivity, morphology and the crystalline quality of the films.

A theoretical investigation of the structure, stability, and electron charge density of cubic, rhomohedral, hexagonal, and monoclinic Al lattices was reported. Results were discussed in light of the so-called anions in metallic matrices (AMM) model, and indicated that, in the entire Al sublattices considered, the shortest zero-pressure Al-Al distance keeps a common value, thus providing further support for the cation recognition hypothesis of the AMM model.

Phase-separation behavior in the sol-gel system of alumina-silica in the presence of poly(ethylene oxide) is investigated. The reduction of Sm(super 3+) to Sm(super 2+) is accomplished in Al2O3-SiO2 macroporous glasses by heat treatment in a reducing atmosphere.

Grafting beta-cyclodextrin cavities has functionalized the galleries of an Mg-Al layered double hydroxide. The adsorbed iodine molecules dissociate in the confined cavities.

A demonstration on the operation of an abstraction channel in the chemisorptions of O2 on Al(111) is presented. The study concluded that in the O2/Al(111) interaction ordinary chemisorptions is hampered because of the slow spin transition whereas the abstraction channel is open due to the large oxygen atom binding energy to Al(111), in contract to transition-metal surfaces.

The state of aluminum atoms in dealuminated and nonhydrated zeolites Y is investigated by a combination of different methods of solid-state NMR spectroscopy. The mean cationic charge per extraframework aluminum atom in nonhydrated zeolites Y was found to depend on the strength of steaming.

2,4,6-Triphenylbenzaldehyde 1 undergoes a condensation reaction with 2-aminophenol to give N-(2',4',6'triphenylbenzylidene)-2-iminopbenol(TPIP) 2. The imine 2 can be reduced with NaB[H.sub.4] in ethanol to form N-(2',4',6'triphenylbenzyl)-2-aminophenol(TPAP) 3. Addition of trimetbylaluminum to 2 or 3 results in the formation of the complexes TPIP-Al[Me.sub.2]*AlMe.sub.3] (4) or TPAP-Al[Me.sub.2] (5). Compounds 2, 3, and 4 have been crystallographically characterized. Key words. N,O ligands, aluminum, m-terphenyl, Schiff bases, X-ray crystallography.

Inorganic multilayer films and hollow shells with pillared architectures are fabricated layer-by-layer on spherical poly(methyl methacrylate) (PMMA) templates as well as flat substrates through the electrostatic self-assembly technique. Positively charged polyoxocations of aluminum Keggin ions are employed both as inorganic binder and as pillaring agent in electrostatic self-assembly with exfoliated unilamellar crystallites of Ti(sub 0.91)O2, which yielded new types of ultrathin films and core-shell composites.

[Al.sub.13.sup.-] is a cluster known for the pronounced stability that arises from coincident closures of its geometric and electronic shells. We present experimental evidence for a very stable cluster corresponding to [Al.sub.13][I.sup.-]. Ab initio calculations show that the cluster features a structurally unperturbed [Al.sub.13.sup.-] core and a region of high charge density on the aluminum vertex opposite from the iodine atom. This ionically bound magic cluster can be understood by considering that [Al.sub.13] has an electronic structure reminiscent of a halogen atom. Comparisons to polyhalides provide a sound explanation for our chemical observations, The formation of strong bonds or closed electronic shells by groups of atoms can create species that react as if they were one atom. Familiar examples include ions such as [...]

The series of amorphous nitrided galloaluminophosphate 'AlGaPON' catalysts with nitrogen contents varying from 0 to 23.3 wt% were obtained by nitriding Al(sub 0.5)Ga(sub 0.5)PO(sub 4) precursor under ammonia flow at 750 degreeC in a tubular furnace. The results compared by using X-ray absorption spectroscopy (XAS) and X-ray photoelectrons spectroscopy on five samples is described.

Various alpha, beta-unsaturated carbonyl compounds were coordinated aluminum tris(1,6-diphenylphenoxide) (ATPH) to give the corresponding Lewis acid-base complexes in distinctive coordinate fashion. ATPH recognizes carbonyl substrates and subsequently orients itself as it forms a stable complex through selective coordination with the carbonyl oxygen.

An enhanced photocurrent was obtained in an Al/polythiophene (PTh) Schottky-barrier cell when the top energy level of the valence band of PTh solid was more negative than the HOMO energy level of porphyrin. It concluded from the results that both a larger thermodynamic driving forces for a photoinduced hole transfer from porphyrin to PTh and a closer distance between the two conjugating planes of porphyrin and PTh are necessary to obtain a larger photocurrent.

Short-range order within a novel aluminophosphate-oxalate hybrid material with the unit cell formula CH2-(NH3)CH(NH3)CH3Al4P6O20(OH)(sub 4)(C2O4)H2O is studied by multinuclear solid-state NMR measurements. The underlying variety of carbon, aluminum, and phosphorus local environment was due to the nonuniform arrangement of the protonated 1,2-diaminopropane species and water molecules residing within the pores of the open-framework material.

In a study of the reaction system methylaluminoxane (MAO)/(C5H5)2ZrMe2, the size of the ion pair [(C5H5)2Zr(u-Me)2AIMe2]+ [Me-MAO]- was determined by pulsed filed-gradient NMR of its cationic moiety. MAO contains various species that produce Me-MAO- anions with different Lewis basicities.

The conduction mechanism in aluminum-doped zinc oxide is studied. Structural investigation shows that crystallographic orientation as well as grain boundary scattering can be neglected.

Photoelectron spectroscopy is combined with ab initio calculations to elucidate the structure and the chemical bonding of a series of MAI(sub 6)(super -) (M=LI, Na, K, Cu and Au) bimetallic clusters. Well resolved photoelectron spectra are obtained for MAI6- (M=LI,Na,K,Cu and Au) at several photon energies.

A study of the low-lying electronic states of AL3As, AL3As-, ALAs3, and ALAs3 (super -) is presented. The B3LYP and CCSD (T) levels are employed for this purpose.

A combination of W-band (super 1)H ENDOR and X-band HYSCORE spectroscopies has provided direct evidence of the coordination environment of Cu(super 2+) exchanged in zeolite Y. W-band (super 1)H ENDOR is used to probe the water ligands, whereas X-band hyperfine sublevel correlation (HYSCORE) spectroscopic measurements were employed to detect (super 27)Al hyperfine couplings.

Ablation of cubic-boron nitride (c-BN) ceramic irradiated by Ti:sapphire laser and Nd:yttrium-aluminum-garnet (YAG) laser pulses is comparatively studied. The chemical composition of the ablated surface of the c-BN ceramic with 110 fs and 100 ps laser is investigated by means of scanning electron microscope (SEM) observation and x-ray photoelectron spectroscopy (XPS) analysis.

A study of the atoms and molecules that are likely to be involved in the combustion of aluminum-based propellants using CBS-QB3 calculations of the enthalpies and free energies, at 298 and 2000 K is presented. The results show that the average absolute differences from experiment of deltaH (298 K), deltaH (2000 K), and deltaG (298 K) are all less than 2.0 kcal/mol and although the deltaG (2000 K) are significantly less accurate, this does not translate into commensurate errors in the equilibrium constants at 2000 K.

A study of the aluminum (III) and amino acid chain interactions with the sulfur containing amino acid chains of cysteine (CYs) and methionine (Met) and the analysis of the interactions with the toxic aluminum (III) and the nontoxic magnesium (II) cations is presented. The results show that Mg (II) binds to all of the neutral ligands with binding energies of 79, 97, 109 and 120 Kcal/mol for SH2, HSCH3, CH3SCH3, and CH3SCH2CH3, while aluminum (III) binds only to the largest ligands and then in a bidentate form with a bond to both S and the terminal C.

A study of the heterogeneous uptake of SO2 on alpha-Al2O3 and MgO particles at 296K, where transmission FT-IR experiments reveal that under dry conditions SO2 reacts with alpha-Al2O3 and sulfite on MgO to form strongly absorbed bisulfite, HSO3- (aq) and sulfite, SO3-2 (aq).

The synthesis and characterization of tert-butylaluminium hydrazides is explained. The tetraaluminium compounds has a novel tricyclic structure with two N-N bonds side-on-coordinated by aluminum atoms.

Research is done on aluminum amidinate species, found to be active in ethylene polymerization, which have been studied using a variety of computational methods, including semiempirical (AMI), Hartree-Fock and density functional theory type calculations, and first-principles MD simulations. In conclusion, the study clearly indicates that it is necessary to model the real catalyst, including bulky substituents if present, to arrive at a proper understanding of structure and activity.

Bismuth oxide on AI2O3 was prepared using Bi(OEt)3 as a precursor and changing the Bi loading systematically and characterized the obtained samples by extended X-ray absorption fine structure (EXAFS) and X-ray photoelectron spectroscopy (XPS). Bismuth-aluminum (rich) binary oxide layers below 9 wt % Bi loading and bismuth (rich) - aluminum clusters above 9 wt % Bi loading was formed at the Al2O3 surface.

CoMgAI-hydrotalcite-like compounds [Co(sub a)Mg(sub b)(OH)(sub c)(TA)(sub d).nH2O] intercalated with terephthalate anions {[C(sub 6)H(sub 4)(COO)(sub 2)](super 2- ) or TA(super 2-)} are prepared using different methods. The as-prepared samples undergo different decomposition pathways when they are heated in air and in nitrogen atmospheres respectively.

An attempt is made to investigate the aluminosilicate MCM-41 materials with Si/Al ratio between 10 and 50 were prepared namely, direct mixed-gel synthesis, and their hydrothermal stability in boiling water using a variety of techniques including powder XRD, N2 sorption studies, and elemental analysis. It is revealed that Al incorporated on the surface/near surface region of the pore walls provide the greatest protection.

Aluminum(III) and magnesium(II) interactions with the asparagine and glutamine amino acid chains are examined by the density functional approach. In conclusion, the binding energies of these complexes are significantly smaller than those of the aluminum(III)/magnesium(II) interactions with the acidic amino acid chains.

The optical and electrochemical properties of blue-emitting heteroleptic aluminum(III) bis(2-methyl-8-quinolinolate)phenolate complexes are investigated. The results have suggested that the electronic effects that modulate the emissive properties in quinolinolate complexes are additive and the effects of individual substituents might be combined to obtain emitters of desired properties.

A qualitative study of the intrinsic reactivity of the intrinsic reactivity of aluminum nanoparticles is presented and the importance of aluminum phase change in the oxidation process and the role/stability of the oxide coating are examined. The findings indicate that the oxidation of oxide-coated nanoaluminium coincides with and is initiated by melting of the aluminum core and subsequent mechanical rupture of the oxide coating.

The study investigated the morphological evolution during heteroepitaxial growth of AlN on GaN by metal-organic chemical vapor deposition. The observation of the study shows that the local stoichiometry at vapor-solid interface strongly influences the adatom kinetics during growth, thereby affecting the nature of strain relaxation and growth mode.

The various mechanisms involved in the direct reduction of nitrite to [N.sub.2] on a Pt(100) electrode in alkaline media are explained.