Academic literature on the topic 'Ternary surface complex'

A projection of the liquidus surface of the quasi-ternary system Cu2S-In2S3-FeS was constructed as a result of experimental studies of quasi-binary and non-quasi-binary sections and based on the data on binary systems comprising a ternary system.Each section (six quasi-binary and four non-quasi-binary ones) was studied separately using complex methods of physicochemical analysis: differential thermal analysis, X-ray phase analysis, and microstructural analysis.It was found that the quasi-ternary system Cu2S-In2S3-FeS has six fields of primary crystallisation of separate phases and eleven monovariant equilibrium curves along which two phases are co-crystallised. Non-variant equilibrium points were obtained through the extrapolation of the direction of monovariant equilibrium curves.The quasi-ternary system Cu2S-In2S3-FeS is characterised by 17 non-variant equilibrium points, where Е1-Е5 are triple eutectic points.The projection diagram of the liquidus surface is characterised by three crystallisation fields of the initial componets (Cu2S, In2S3, FeS), four fields of binary compounds, and one field of a complex compound (CuFeIn3S6).Since complete solubility of the initial components in liquid and solid states is observed in the quasi-binary section CuIn5S8‑FeIn2S4, the fields of primary crystallisation of CuIn5S8 and FeIn2S4 are absent; they are replaced by an unlimited solid solution based on these components.The fields of primary crystallisation of Cu2S, FeS, and CuInS2 are the most extensive in the ternary system Cu2S-In2S3-FeS. The reactions occurring at monovariant equilibrium points are presented.

The interaction and phase separation in a ternary mixture composed of hydroxypropyl methyl cellulose (HPMC), sodium carboxymethyl cellulose (NaCMC), and sodium dodecylsulfate (SDS) were investigated by tensiometry. Surface tension measurements of binary mixtures (0.7 % HPMC and 0.00-2.00 % SDS) and of ternary mixtures (0.7 % HPMC, 0.3 % NaCMC, and 0.00-2.00 % SDS) were performed. The measurements indicated interaction between HPMC and SDS, which resulted in HPMC-SDS complex formation. The critical association concentration, CAC, and polymer saturation point, PSP, were determined. Phase separation of ternary HPMC/SDS/NaCMC mixtures occurs at SDS concentration > CAC, i.e., when the HPMC-SDS complex is formed. The volume of the coacervate increases with increasing SDS concentration, and at SDS concentrations >1.00 %, the coacervate vanishes. The surface tensions (?) of ternary HPMC/SDS/NaCMC mixtures in the precoacervation region and at the onset of the coacervation region are similar to the ? of the corresponding binary HPMC-SDS mixtures, while in the coacervation and post coacervation region, they are close to the ? of the corresponding SDS solutions.

During exocytosis, chemical transmitters stored in secretory vesicles can be released upon fusion of these intracellular organelles to the plasma membrane. In this process, SNARE proteins that form a ternary core complex play a central role. This complex could provide the means for generation/storage of energy necessary for driving the fusion of vesicular and plasma membranes. Recently, the amount of energy for (dis)assembly of the ternary complex has been measured using various experimental approaches, including atomic force microscopy, the surface force apparatus, and isothermal titration calorimetry. The obtained measurements are in good agreement with the calculated energy required for membrane fusion achieved by theoretical modeling approaches. Whether the energy expenditure to form the ternary SNARE complex can be utilized towards membrane fusion and/or docking/tethering of vesicles to the plasma membrane still remains one of the key contemporary issues in biophysics and neuroscience.

The fluorescence studies suggested that the Eu(iii) sorbs as Eu(iii)–oxalate complex (binary system) onto kaolinite surface in the ternary system of Eu(iii), oxalic acid and kaolinite at circumneutral pH conditions.

Adsorption equilibria of the binary and ternary solutions of alcohols in benzene and n-heptane on silica gel have been studied in order to clarify their mechanisms of adsorption. Excess adsorption isotherms have been measured for hydrocarbon solutions of methanol, ethanol, butanol and pentanol. Interpretation of the experimental data was performed in terms of material balance between bulk and surface phase. In n-heptane solutions the multilayer surface structure is formed and the surface phase contains the alcohol only. For benzene and ternary (alcohol + benzene + n-heptane) solutions a mixed surface phase is observed whose composition is determined by competition of liquid components for silica surface as well as its tendency to complex. Moreover, the extent of adsorption in methanol systems is connected with the miscibility of liquid components.

Two novel core–shell structure ternary terbium composites SiO 2(600) @Tb(MABA-Si)·L(L:dipy/phen) nanometre luminescence materials were prepared by ternary terbium complexes Tb(MABA-Si)·L 2 ·(ClO 4 ) 3 ·2H 2 O shell grafted onto the surface of SiO 2 microspheres. And corresponding ternary terbium complexes were synthesized using (CONH(CH 2 ) 3 Si(OCH 2 CH 3 ) 3 ) 2 (denoted as MABA-Si) as first ligand and L as second ligand coordinated with terbium perchlorate. The as-synthesized products were characterized by means of IR spectra, 1 HNMR, element analysis, molar conductivity, SEM and TEM. It was found that the first ligand MABA-Si of terbium ternary complex hydrolysed to generate the Si–OH and the Si–OH condensate with the Si–OH on the surface of SiO 2 microspheres; then ligand MABA-Si grafted onto the surface of SiO 2 microspheres. The diameter of SiO 2 core of SiO 2(600) @Tb(MABA-Si)·L was approximately 600 nm. Interestingly, the luminescence properties demonstrate that the two core–shell structure ternary terbium composites SiO 2(600) Tb(MABA-Si)·L(dipy/phen) exhibit strong emission intensities, which are 2.49 and 3.35 times higher than that of the corresponding complexes Tb(MABA-Si)·L 2 ·(ClO 4 ) 3 ·2H 2 O, respectively. Luminescence decay curves show that core–shell structure ternary terbium composites have longer lifetime. Excellent luminescence properties enable the core–shell materials to have potential applications in medicine, industry, luminescent fibres and various biomaterials fields.

A theoretical study of Pb(II) square planar thioselenophosphinate, Pb[(C6H5)2PSSe]2 precursor for the chemical vapour deposition process of preparing lead chalcogenides, has been carried out. The geometries of the species were optimized by employing the density functional theory. The transition states as well as the linked intermediates linking them were confirmed with frequency analyses. The density functional theory calculation (M06/LACVP*, gas) reveals that kinetically, the steps that lead to PbSe formation are more favourable than those that lead to PbS and ternary PbSexS1−x formation on both the singlet and the doublet potential energy surface. However, thermodynamically, the steps that lead to ternary PbSexS1−x formation are more favourable than those that lead to PbSe and PbS formation on the doublet potential energy surface. On the singlet potential energy surface, an alternative route leading to the formation of ternary PbSexS1−x is more favoured on both thermodynamic and kinetic grounds than those that lead to PbSe and PbS formation. The computational studies indicate that the decomposition of the complex in chemical vapour deposition may involve more than one step, and thus the formation of ternary PbSexS1−x is a result of thermodynamic and kinetic factors in controlling the material formed during the deposition process.

This thesis is a summary of five papers with focus on adsorption processes of various monocarboxylates and aminocarboxylates at the water/goethite interface. Interaction of organic acids at the water/mineral interfaces are of importance in biogeochemical processes, since such processes have potential to alter mobility and bioavailability of the acids and metal ions.

In order to determine the coordination chemistry of acetate, benzoate, cyclohexanecarboxylate, sarcosine, MIDA (methyliminediacetic acid), EDDA (ethylenediamine-N,N’-diacetic acid) and EDTA (ethylenediamine-N,N’-tetraacetic acid) upon adsorption to the goethite (alpha-FeOOH) surface, a combination of quantitative measurements with attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) was utilized.

Over the pH range studied here (pH 3- 9) all ligands, except for sarcosine, have been found to form surface complexes with goethite. In general, theses were characterized as outer sphere surface complexes i.e. with no direct interaction with surface Fe(III) metal ions. Furthermore, two types of different outer-sphere complexes were identified, the solvent-surface hydration-separated ion pair, and hydration-shared ion pair. For the monocarboxylate surface complexes distinction between these two could be made. At high pH values the solvent-surface hydration-separated ion pair was the predominating complex, while at low pH the surface complex is stabilized through the formation of strong hydrogen bonds with the goethite surface. However, it was not possible to clearly separate between the two outer-sphere complexes for coordination of the aminocarboxylates with the surface of goethite. Additionally, EDDA also formed an inner-sphere surface complex at high pH values. The EDDA molecule was suggested to coordinate to the surface by forming a five membered ring with an iron at the goethite surface, through the amine and carboxylate groups.

Contrary to the other ligands studied, EDTA significantly induced dissolution of goethite. Some of the dissolved iron, in the form of the highly stable FeEDTA- solution complex, was indicated to re-adsorb to the mineral surface as a ternary complex. Similar ternary surface complexes were also found in the Ga(III)EDTA/goethite system, and quantitative and spectroscopic studies on adsorption of Ga(III) in presence and absence of EDTA showed that EDTA considerably effects speciation of gallium at goethite surface.

The collective results in this thesis show that the affinity of these ligands for the surface of goethite is primarily governed by their chemical composition and structure, and especially important are the types, numbers and relative position of functional groups within the molecular structure.

The mining of sulphidic ore to extract metals such as zinc and copper produces huge quantities of waste material. The weathering and oxidation of the waste produces what is commonly known as Acid Mine Drainage (AMD), a dilute sulphuric acid rich in Fe(II) and heavy metals. This thesis serves to summarise five papers reporting how the precipitation of Fe(III) phases can attenuate the contamination of heavy metals by adsorption processes.

Schwertmannite (Fe8O8(OH)6SO4) is a common Fe(III) mineral precipitating in AMD environments at pH 3-4. The stability and surface chemistry of this mineral was investigated. It was shown that the stability depended strongly on pH and temperature, an increase in either promoted transformation to goethite (α-FeOOH). Two pH dependent surface species of SO42- were detected with infrared (ATR-FTIR) spectroscopy.

The adsorption of Cu(II), Pb(II) and Zn(II) to schwertmannite occurred at lower pH than to goethite, whereas Cd(II) adsorption occurred in a similar pH range on both schwertmannite and goethite. Extended x-ray absorption fine structure (EXAFS) spectroscopy suggests two surface species for Cu(II) and Cd(II) at the schwertmannite surface. Cu(II) adsorbs monodentately and Cd(II) bridging bidentately to adsorbed SO42-. Both metal ions also adsorb in a bridging bidentate mode to the surface hydroxyl groups. At pH 7.5 up to 2.7 μmol Cd(II) m-2 could be adsorbed to schwertmannite, indicating a large adsorption capacity for this mineral.

The acid-base properties of two NOM samples were characterised and could be well described as diprotic acids below pH 6. The adsorption of NOM to schwertmannite and goethite was very similar and adsorption occured in a very wide pH range.

High concentrations of NOM increased the adsorption of Cu(II) to goethite at low pH whereas a slight decrease was noted at low concentrations of NOM. No effect was detected in the schwertmannite system.

The formation of Fe(III) phases from precipitation of AMD was shown to be very pH dependent. At pH 5.5 a mixture of minerals, including schwertmannite, formed whereas at pH 7 only lepidocrocite (γ-FeOOH) formed. The concentration of Zn(II) in AMD could by adsorption/coprecipitation be reduced to environmentally acceptable levels.

Le but de notre travail était d'étudier comment des interactions impliquant des acides nucléiques pouvaient réguler le cycle viral du virus de l'hépatite C (VHC). L'ARN génomique du VHC est très structuré au niveau de ses extrémités 5' et 3'. La tige-boucle 5BSL3.2 a été décrite comme interagissant avec la SLIIId, la Seq9110 et la SL2 par génétique inverse et expériences de complémentation de mutations. La résonance plasmonique de surface (SPR) a été utilisée afin de caractériser ces interactions. Cela nous a conduit à développer des méthodes permettant d’étendre l'utilisation de la SPR. Nous avons pu observer, in vitro, une interaction entre la 5BSL3.2 et miR-122, un microARN fortement exprimé dans les hépatocytes. Nos résultats ont également montré que la SL2 était une séquence ARN pouvant former au moins deux conformations. L'une étant capable d'interagir avec la 5BSL3.2 et l'autre pouvant s'auto-associer. L'étude de cette dimérisation sur modèle cellulaire a montré qu'elle était impliquée dans les mécanismes de la réplication virale. Le développement d'une méthode d'analyse des complexes ternaires a permis la caractérisation simultanée du complexe formé entre la boucle interne de la 5BSL3.2 et ses partenaires (Seq9110 et SLIIId) ainsi que du complexe formé entre la boucle apicale et ses partenaires (SL2 et miR-122). Ces résultats ont montré que les deux sites de liaison de la 5BSL3.2 étaient structurellement indépendants. Ces interactions pourraient donc coexister dans un contexte physiologique. Les résultats montrent que la SLIIId et la Seq9110 sont en compétition pour interagir avec la boucle interne de la 5BSL3.2 tandis que la tige-boucle SL2 et miR-122 sont en compétition pour interagir avec la boucle apicale de la 5BSL3.2. La 5BSL3.2 est donc un motif ARN structuré pouvant agir comme une plaque tournante, capable d'interagir avec d'autres régions de l'ARN génomique tandis que la SL2 a montré que les deux interactions qu'elle pouvait former, mutuellement exclusives, étaient importantes pour la prolifération virale. Les mécanismes de compétition observés pourraient être impliqués dans la commutation entre les différentes étapes du cycle viral
We are interested in understanding how interactions involving nucleic acids regulate the life cycle of the Hepatitis C virus (HCV). The HCV genomic RNA is highly structured at the 5' and 3' ends. The stem-loop 5BSL3.2 was described to interact with the SLIIId, the Seq9110 and the SL2 by reverse genetics and complementation mutation experiments. Surface plasmon resonance (SPR) was used to characterize these interactions. This led us to develop methods to expand the use of this technique. We described in vitro evidences for an interaction between 5BSL3.2 and miR-122, a microRNA highly expressed in hepatocytes. As shown by our results, SL2 is a highly dynamic RNA motif that fluctuates between at least two conformations: one is able to hybridize with 5BSL3.2 and the other one is capable of self-associating. The study of this dimerization in living cells has shown an implication of this phenomenon in viral replication processes. The development of a ternary complex analysis method allowed the characterization of the Seq9110 (or SLIIId) and SL2 (or miR-122) interacting with 5BSL3.2. Our results shown that the two binding sites of 5BSL3.2, the apical and internal loops, are structurally independent, suggesting that these interactions may coexist in a physiological context. SLIIId and Seq9110 were shown to compete to interact with 5BSL3.2 internal loop while SL2 and miR-122 were shown to compete to interact with 5BSL3.2 apical loop. In conclusion, 5BSL3.2 is a structured RNA motif that could act as a molecular hub capable of interacting with other genomic RNA regions while the two interactions of the SL2, mutually exclusives, were shown to be crucial for viral proliferation. The competition mechanisms observed could be involved in the commutation between viral cycle steps

Abstract Condensation phenomenon has been studied actively for decades because of its extensive and significant applications in various fields of technology and engineering. The condensation phenomenon of condensable component in supersonic flows is still not understood very well as a result of the complex nucleation and droplet growth process, especially the condensation characteristic of gas mixture. In this paper, the Laval nozzle was designed based on the bi-cubic curve, state equation of real gas, arc plus straight line and viscous correction of boundary layer. The physical and mathematical models were developed to predict the condensation process in the supersonic air flows based on the nucleation and droplet growth theories, surface tension model and gas-liquid governing equations. The condensation processes of gaseous water/air binary (single condensable) gas and water/ethanol/air ternary (double condensable) gas mixture in the designed nozzle were simulated, and the reliability of the established models was verified by the experimental data. By comparing the condensation process of water/air binary gas with water/ethanol ternary gas, the influence of the second condensable component on the condensation process was analyzed. The results show that in the condensation process of gaseous water, as the pressure and temperature of water vapor decrease in the nozzle, spontaneous condensation occurs further downstream the nozzle throat. The nucleation rate grows rapidly from 0 to peak in a very short distance. With the consumption of water vapor, due to the decrease of the degree of supercooling, the nucleation environment is destroyed, and the nucleation rate quickly decreases to 0. The nucleation process is rapid in time and space, while the droplet growth process could maintain longer. The droplet number and mass fraction increase continuously till the nozzle outlet. There is a weak condensation in the nozzle due to the release of latent heat, but it is not obvious because the air acts as a heat container and absorbs the latent heat released by condensation. In the water/ethanol/air ternary system, the ethanol nucleates prior to water vapor. With the increase of supercooling, water vapor also begins to nucleate. In essence, there are two kinds of condensation nuclei (water nuclei and ethanol nuclei), and both the water and ethanol vapor can aggregate on these two kinds of condensation nuclei. Compared with the condensation process of water, the Wilson point of condensation is closer to the throat and the outlet mass fraction of liquid phase is greater in the condensation process of water/ethanol mixture, which shows that the water and ethanol can affect and promote each other. The maximum nucleation rate, droplet growth rate, droplet radius and outlet mass fraction of liquid phase of water/air binary and water/ethanol/air ternary mixture are about 9.46 × 1026 m−3s−1 and 2.57 × 1027 m−3s−1, 1.65 × 10−5 m/s and 1.02 × 10−5m/s, 1.32 × 10−7m and 1.63 × 10−7m, 0.19% and 1.34%, respectively.

Abstract The European Union is banning the use of Pb in electronic products starting July 1st, 2006. Printed circuit board assemblies or “motherboards” require that planned CPU sockets and BGA chipsets use lead-free solder ball compositions at the second level interconnections (SLI) to attach to a printed circuit board (PCB) and survive various assembly and reliability test conditions for end-use deployment. Intel is pro-actively preparing for this anticipated Pb ban, by evaluating a new lead free (LF) solder alloy in the ternary Tin- Silver-Copper (Sn4.0Ag0.5Cu) system and developing higher temperature board assembly processes. This will be pursued with a focus on achieving the lowest process temperature required to avoid deleterious higher temperature effects and still achieve a metallurgically compatible solder joint. One primary factor is the elevated peak reflow temperature required for surface mount technology (SMT) LF assembly, which is approximately 250 °C compared to present eutectic tin/lead (Sn37Pb) reflow temperatures of around 220 °C. In addition, extended SMT time-above-liquidus (TAL) and subsequent cooling rates are also a concern not only for the critical BGA chipsets and CPU BGA sockets but to other components similarly attached to the same PCB substrate. PCBs used were conventional FR-4 substrates with organic solder preservative on the copper pads and mechanical daisychanged FCBGA components with direct immersion gold surface finish on their copper pads. However, a materials analysis method and approach is also required to characterize and evaluate the effect of low peak temperature LF SMT processing on the PBA SLI to identify the absolute limits or “cliffs” and determine if the minimum processing temperature and TAL could be further lowered. The SLI system is characterized using various microanalytical techniques, such as, conventional optical microscopy, scanning electron microscopy, energy dispersive spectroscopy and microhardness testing. In addition, the SLI is further characterized using macroanalytical techniques such as dye penetrant testing (DPT) with controlled tensile testing for mechanical strength in addition to disbond and crack area mapping to complete the analysis.

Abstract WET ETCHING is an important part of the failure analysis of semiconductor devices. Analysis requires etches for the removal, delineation by decoration or differential etching, and study of defects in layers of various materials. Each lab usually has a collection of favored etch recipes. Some of these etches are available premixed from the fab chemical supply. Some of these etches may be unique, or even proprietary, to your company. Additionally, the lab etch recipe list will usually contain a variety of classical "named etches". These recipes, such as Dash Etch, have persisted over time. Although well-reported in the literature, lab lists may not accurately represent these recipes, or contain complete and accurate instructions for their use. Time seems to have erased the understanding of the purpose of additives such as iodine, in some of these formulas. To identify the best etches and techniques for a failure analysis operations, a targeted literature review of articles and patents was undertaken. It was a surprise to find that much of the work was quite old, and originally done with germanium. Later some of these etches were modified for silicon. Much of this work is still applicable today. Two main etch types were found. One is concerned with the thinning and chemical polishing of silicon. The other type is concerned with identifying defects in silicon. Many of the named etches were found to consist of variations in a specific acid system. The acid system has been well characterized with ternary diagrams and 3-D surfaces. The named etches were plotted on this diagram. The original formulas and applications of the named etches were traced to assure accuracy, so that the results claimed by the original authors, may be reproduced in today's lab. The purpose of this paper is to share the condensed information obtained during this literature search. Graphical data has been corrected for modem dimensions. Selectivities have been located and discussed. The contents of more than 25 named etches were spreadsheeted. It was concluded that the best approach to delineation is a two-step etch, using uncomplicated and well-characterized standard formulas. The first step uses a decoration or differential etch technique to define the junctions. Formulations for effective decoration etches were found to be surprisingly simple. The second step uses a selective etch to define the various interconnections and dielectric layers. Chromium compounds can be completely eliminated from these formulas, to meet environmental concerns. This work, originally consisting of 30 pages with 106 references, has been condensed to conform with the formatting requirements of this publication.