Amount Of Reaction Product Research Articles

Effect of PVA fibers grafted with MWCNTs on the shrinkage behaviors of engineered geopolymer composite (EGC)

Geopolymer have been considered as a promising alternative for the development of high-ductility and eco-friendly engineered materials. In this study, modified PVA fibers grafted with MWCNTs(PM) are used as additives to investigate their impact on the drying shrinkage, autogenous shrinkage and chemical shrinkage of Engineered Geopolymer Composites(EGC). Additionally, various micro-structure techniques, including X-ray Diffraction(XRD) and Scanning Electron Microscopy(SEM), are employed to examine the morphology and chemical composition of EGC. The experimental findings indicates that PVA fibers and MWCNTs both help to mitigate the drying shrinkage and autogenous shrinkage of the EGC. When the PVA fiber content is 2.0 % and the MWCNT content is 1.0 ‰, the 90-day drying shrinkage and autogenous shrinkage values of the EGC are minimized, reducing by 31.67 % and 34.16 %, respectively, in comparison to the control group. However, the incorporation of MWCNTs increases the chemical shrinkage of the geopolymer matrix, with the chemical shrinkage value reaching its maximum when the MWCNT content is 1.0 ‰. Micro-structural analysis reveals that the inclusion of PM leads to an improvement in the quantity of reaction products without affecting their type. Furthermore, the incorporation of PM refines the overall pore structure, restricts the crack development and enhances the interfacial bonding effect of EGC. Notably, a correction prediction model for drying shrinkage strain and autogenous shrinkage strain, incorporating the influence coefficients of PVA fibers and MWCNTs, is constructed under constant humidity and temperature conditions. This significantly improves the prediction accuracy of drying shrinkage and autogenous shrinkage of EGC.

Characterization, pre-treatment, and potential applications of fine MSWI bottom ash as a supplementary cementitious material

With the development of waste recovery techniques, previous research has revealed that coarse fractions of municipal solid waste incineration (MSWI) bottom ash (BA) after proper treatment could be applied in the construction sector, while the fines are seldom recovered in practice and normally landfilled. This study explores the potential application of fine MSWI BA (0–2 mm) as a supplementary cementitious material (SCM) in Portland cement (PC) mixtures. Mechanical and chemical pre-treatment approaches have been designed with various conditions to optimize the treating process. The chemical and mineralogical compositions, as well as the metallic Al content in BA were characterized before and after the pre-treatment. It was found that both methods are effective in removing the metallic Al content in BA, Moreover, BA derived from mechanical treatment exhibited more contribution to the hydration reaction in PC mixtures, as revealed by the amount of reaction products and mineral phases formed in hardened trial mixtures. BA obtained was further partially blended in PC mortars to evaluate the performance as compared to SCMs and inert fillers. It was found that treated BA resulted in a slight retarding effect on the reaction kinetics. Treated BA behaved better than the coal fly ash to contribute to the strength development, while the inclusion of BA did not lead to significant influences on the workability.

Dry shrinkage and micro-structure of alkali-activated fly ash/slag pastes incorporated with silane coupling agent modified MWCNTs

In this study, functionalized Multi-Walled Carbon Nanotubes (MWCNTs) grafted with a silane coupling agent (MS) at concentrations of 0.1 %, 0.2 %, 0.3 %, and 0.4 % were used as additives to investigate their impact on the reaction kinetics, working performance, mechanical strength, and drying shrinkage of alkali-activated fly ash/slag (AAFS) pastes. Additionally, various micro-structure techniques, including X-ray Diffraction (XRD), Thermogravimetric Analysis (TG), Differential Scanning Calorimetry (DSC), Differential Thermal Analysis (DTA), nitrogen (N2) absorption, and Scanning Electron Microscopy-Energy Dispersive Spectroscopy (SEM-EDS), were employed to examine the morphology, chemical composition, and mineralogy of AAFS pastes. The experimental findings indicate that all the modified AAFS pastes exhibit prolonged setting time and increased flowability compared to the control AAFS pastes, with the enhancement of these properties being proportional to the MS content. Specifically, with the addition of 0.3 wt% MS, the compressive strength and flexural strength of LGMS-0.3 % were 41.2 MPa and 6.4 MPa, respectively, at the 28-day curing age, representing a 15.7 % and 39.1 % increase compared to the control AAFS pastes. Simultaneously, significant reductions in mass loss and drying shrinkage of over 70 % and 90 % were observed, respectively, in comparison to the control AAFS pastes. Micro-structural analysis reveals that the inclusion of MS leads to an increase in the quantity of reaction products without affecting their type. Furthermore, the incorporation of MS decreases the total porosity and the proportion of capillary pores with diameters ranging from 2 nm to 50 nm, resulting in the refinement of the overall pore structure of AAFS pastes. Notably, the three-dimensional interpenetrating network formed by MWCNTs and the silane coupling agent positively influences the mitigation of drying shrinkage and the enhancement of the mechanical strength of AAFS pastes.

Mechanisms of controlled crystallization of struvite-K by NTA and EDTA sodium salts

The mechanisms by which ethylenediaminetetraacetic acid (EDTA) and nitrilotriacetic acid (NTA) sodium salts control the precipitation of struvite-K from solution have been investigated at room temperature, pH = 9, two degrees of supersaturation and two stirring speeds. The interest spans from the potassium and phosphorus recovery from wastewaters, the prevention of scale deposits in wastewater treatment plants, to the modification of magnesium phosphate cement reaction. Both molecules influenced the spontaneous precipitation by extending the induction time, reducing the apparent rate of crystallization and the amount of reaction product. When adding 20 mM of EDTA, at the highest supersaturation degree, the rates dropped from 2.14 min−1 and 4.09 min−1 to 1.36 min−1 and 1.71 min−1, under fast and slow stirring speed conditions, respectively. Conversely, at lower supersaturation the precipitation was almost completely inhibited. Similar inhibiting effect was observed for NTA. The additives were found to influence the reaction path by exploiting their complexing ability in solution, thus depressing the supersaturation degree in Mg2+ ions with respect to struvite-K, and by molecular adsorption at the forming solid surfaces, hindering nucleation and crystal growth. The surface adsorption process has been confirmed by the more negative zeta potential measured on the crystals (from −14.5 ± 1.0 mV to −17.0 ± 1.6 mV and −20.8 ± 3.0 mV for EDTA and NTA, respectively). Both additives induced an overall reduction in crystal size (up to 85 %) and a reduced elongation of the precipitated crystals (aspect ratio decreasing from 2.3 to 1.3 and 1.7 for EDTA and NTA, respectively) in consequence of the preferential adsorption at the (101) and (1¯ 01) faces.

Improved hydroxyl radical production by electric-field-induced catalysis in O3/H2O2 process: A reactive molecular dynamics perspective

O3/H2O2 process, as a well-used ozone advanced oxidation technology, has been considered to be suitable for treating a variety of organic wastewater. However, the low solubility of ozone in hydrogen peroxide aqueous solution makes the catalytic effect to ozone reaction unsatisfactory. In this study, a novel method of external electric field (EEF) catalyzing O3/H2O2 process was proposed. The chemical reaction in O3/H2O2 process under EEF were investigated by reaction molecular dynamics simulation. The mechanism of the catalytic effect of EEF on chemical reactions in the O3/H2O2 system was revealed by analyzing the system energy, hydrogen bond energy, reaction rate and degree of reaction of the reactants, and the amount of reaction products under EEF with different strength. The results show that EEF can significantly promote the ionization reaction of H2O2 to produce more HO– 2, which further promote the reaction of O3, thus ultimately leads to the increase of •OH production and generation rate. In addition, the catalytic effect of EEF is proportional to the field strength. When the amount of ozone is constant, the concentration of hydrogen peroxide will affect the catalytic effect of EEF.

Optimized Hole Injection, Diffusion, and Consumption for Efficient Metal-Assisted Chemical Etching Depending on the Silicon Doping Type and Metal Catalyst Area

Even though metal-assisted chemical etching (MACE) has been widely used for silicon (Si) nano/micromachining due to its low cost and high applicability, it is still difficult to fabricate elaborate Si nano/microstructures for high-value applications. In particular, further studies about effective factors in the MACE process with systematic approaches are highly required to obtain explicitly controlled MACE products. In this study, how the Si doping type and gold (Au) catalyst area influence MACE products in terms of the hole behavior during MACE is investigated. The type-dependent etching rate of MACE, amount of reaction products, and lateral etching/porosity of the MACE product are characterized with hole injection, diffusion, and consumption scenarios, respectively. Moreover, it is demonstrated that the dependence of the etching rate of MACE and stability/porosity of the MACE product on the Au catalyst area can be understood from the point of view of hole injection per interfacial contact plane area of the Au catalysts. As a result, elaborately controlled Si nano/microstructures can be obtained through an effective and accurate MACE process due to the optimized hole behavior. These findings could increase the accessibility and commercial availability of MACE products in many fields.

Coupled thermodynamic modelling and experimental study of sodium hydroxide activated slag

In previous researches, the thermodynamic modelling of alkali-activated slag was conducted as a function of the degree of reaction of slag, which makes it difficult to compare the modelling results with the experimental results in a time scale. In this study, the reaction kinetics of sodium hydroxide activated slag was studied using isothermal calorimetry and quantified using the Ginstling-Brounshtein equation. With the quantified reaction kinetics, the hydration of slag was thermodynamically modelled in a time scale. Based on the thermodynamically modelled phase assemblage, chemical shrinkage and phase evolution were derived as a function of time.Besides the isothermal calorimetry, a series of experimental techniques were used to evaluate the thermodynamic modelling results. Inductively coupled plasma-optical emission spectroscopy (ICP-OES) was used to investigate the pore solution composition. Thermogravimetric analysis (TGA) and X-ray diffraction (XRD) were used to study the reaction products. Energy-dispersive X-ray spectroscopy (EDX) was used to examine the elemental composition of reaction products. The experimental results were presented, discussed, and used to evaluate the thermodynamic modelling results in terms of pore solution composition and reaction products. The modelled pore solution composition matched the experimentally measured data within ± 1 order of magnitude. The thermodynamic modelling and experimental results were in agreement regarding bound water, type and amounts of reaction products.

An Immobilized Enzyme Reactor for Spatiotemporal Control over Reaction Products.

This paper describes a microfluidic chip wherein the position and order of two immobilized enzymes affects the type and quantity of reaction products in the flowing fluid. Assembly of the chip is based on a self-assembled monolayer presenting two orthogonal covalent capture ligands that immobilize their respective fusion enzyme. A thiol-tagged substrate is flowed over a region presenting the first enzyme-which generates a product that is efficiently transferred to the second enzyme-and the second enzyme's product binds to an adjacent thiol capture site on the chip. The amount of the three possible reaction products is quantified directly on the chip using self-assembled monolayers for matrix-assisted laser desorption/ionization mass spectrometry, revealing that the same microsystem can be spatiotemporally arranged to produce different products depending on the device design. This work allows for optimizing multistep biochemical transformations in favor of a desired product using a facile reaction and analytical format.

Formation of clay minerals on Mars: Insights from long-term experimental weathering of olivine

Laboratory experiments are useful to constrain the environmental parameters that have allowed the formation of the ancient hydrous mineralogical assemblages observed at the surface of Mars, which are dominated by ferric smectites. Weathering under a dense CO2 atmosphere on early Mars is a process frequently invoked to explain their formation, but has proven difficult to test in the laboratory due to low reaction rates. Here, we present a long-term weathering experiment (470 days, at 45 °C) of forsteritic olivine specially designed to increase as much as possible the amount of reaction products and thus allow their detailed mineralogical, petrological and chemical characterization by FTIR, SEM and TEM. Our results show the formation of crystalline smectites both under 1 bar of CO2 and under ambient air. However, important differences are observed between the two types of conditions. The smectite formed under CO2 has an average chemical formula per half unit-cell of Si3.92Al0.16Fe3+0.78Mg1.66 Cr0.01Ni0.06K0.04Ca0.04.O10(OH)2. It is thus intermediate between a trioctahedral Mg-rich saponite and a dioctahedral ferric smectite. It is also clearly enriched in Fe compared its counterpart formed under ambient air, which has an average chemical formula per half unit-cell of Si3.68Al0.12Fe3+0.37Mg2.61Cr0.01Ni0.02K0.04Ca0.25.O10(OH)2. This result demonstrates that the enrichment in Fe observed for Martian smectites is to be expected if they were formed by low-temperature weathering under a dense CO2 atmosphere. Another difference is the nature of the accompanying phases, which includes amorphous silica (in the form of opal spheres 10 to 100 nm in diameter) and Mg-carbonates under CO2, but is limited to rare kaolinite under ambient air. The observation of kaolinite particles under air and the significant amount of Al measured in smectites under both atmospheres, despite the Al-poor nature of the initial material, shows that this element is easily concentrated by low-temperature weathering processes. At a larger scale, this concentration mechanism could be responsible for the formation of Al-rich upper horizons, as frequently observed on Mars.

The Influence of Microbial Agent on the Mineralization Rate of Steel Slag

Bacteria‐based mineralization is a new technique to use the steel slag. In this article, an experimental examination was performed to find out the steel slag advancement by the addition of the microbial agent that has the possibility to accelerate mineralization ability of bacteria. It is observed that, under natural and CO2 pressure curing conditions, the carbonation rate is significantly raised when microorganisms are added to the steel slag. The increased ratio of microorganisms leads to a better carbonation rate. The reaction products formed by bacteria mineralization were analyzed with the scanning electron microscope (SEM) and X‐ray diffraction (XRD), and the amount of reaction products was examined by thermogravimetric analysis. The results show that the compressive strength and carbonation speed rose with the increase in microorganism content. Bacterial could accelerate the rate of carbon sequestration in the mineralization process. The compressive strength of steel slag with 1.5% bacterial could reach up to 51.5 MPa. The micron‐sized and roughness mineralization product induced by microorganisms apparently resulted in a denser and compacted structure. The carbon depth increased by 50%, and the content of calcite increased by 3 times. These mineralization products would fill in the pore of steel slag cementitious materials and form the integrated and denser structure which produces more strength.

Selection of Desulfurizer and Control of Reaction Products on Flue-Gas Desulfurization Using Chemical-Looping Technology

Chemical-looping technology (CLT) can achieve energy efficiency and reduce the environmental pollution and is usually conducted on a fixed-bed reactor. In this paper, the thermodynamic simulations for flue-gas desulfurization (FGD) systems with CLT are carried out using HSC Chemistry software to choose a suitable desulfurizer, control the type and quantities of reaction products, and collect sulfur-containing byproducts with high economic value. The Ellingham diagrams are developed to relate the Gibbs free energy of the relevant reactions to the temperature. The fixing-sulfur potential; the reaction degree with CO2, H2O, and CO; and the acceleration effect of removing NOx of different metal oxides in 100 to 300 °C are estimated. Compared comprehensively, Mn-based oxides have distinct advantages for flue-gas desulfurization using CLT. Based on calculation results, both low reaction temperatures (T 4) can effectively prevent the loss of sulfur element. In the regene...

High Performance All-Solid State Lithium-Air Batteries Employing Aluminum-Substituted Lithium Lanthanum Titanate Solid Electrolyte

Recently, lithium(Li)-air battery has attracted much attention due to its extremely high theoretical specific energy density as 11,680 Wh kg-1 Li, which can be even comparable to that of gasoline. Despite potential of Li-air battery, the commercialization of the battery is a great challenge, since it can suffer from plenty of problems majorly associated with the use of liquid electrolytes and metallic Li anode; leakage, flammability, electrochemical instability under reduced oxygen environment and uncontrollable dendritic growth of Li. In this study, to address these issues, all-solid state Li-air battery has been proposed. By using a stable solid electrolyte with proper Li+ conductivity, the risks of leakage, short-circuit and fire/explosion can be successfully addressed. Moreover, the solid electrolyte can act as a barrier to protect Li metal from harmful gases such as O2, CO2 and moisture diffusing from outside air. In this study, we used aluminum-substituted lithium lanthanum titanate (A-LLTO) ceramic as a main ceramic solid electrolyte for all-solid state Li-air batteries. Herein, A-LLTO ceramic with a nominal formula of (Li0.33La0.56)1.005Ti0.99Al0.01O3 was prepared using citrate-gel method. In particular, the air electrode was specially designed by engaging a thin layer solid electrolyte to form an integrated cathode structure. The integrated cathode consisted of a dense ~20-µm-thick A-LLTO solid electrolyte layer adhering to the 500-µm-thick pellet of porous cathode. Moreover, CoO catalyst particles were directly deposited on the surface of A-LLTO cathode backbone. Further, due to instability of A-LLTO solid electrolyte against Li metal anode, an interlayer of composite gel polymer electrolyte (CGPE) was inserted between A-LLTO and Li metal. The interlayer CGPE was stabilized by the addition of small amount of an ionic liquid. After cell assembly, the solid-state Li-air cell was cycled at the current density of 0.3 mA cm-2 in pure O2 gas atmosphere at 50 oC. Under the limited capacity mode of 500 mAh g-1, the cell exhibited the cycle life of 132 cycles. During the cycling process, the discharge potential of the cell almost remained. Meanwhile, the charge cell potential appeared to increase significantly. By using SEM, XPS and Raman spectra analysis, the formation of reaction products on the cathode surface after cycling test was identified. With the increase in cycle number of discharge-charge, the amount of reaction products was found to increase. This demonstrates the degradation of catalytic activity of CoO catalyst. Because Li2O2 possesses the low Li ionic conductivity of 4×10-19 S cm-1 and low electrical conductivity of 5×10-20 S cm-1, it hinders the transportation of electrons and Li+ ions in the cathode. Accordingly, the degree of polarization for the cell increased gradually with cycle. Although the solid state Li-air cell developed in this work could prevent the problems which can happen when liquid electrolyte is used, its life span was not still satisfactory. Therefore, the factors such as operation temperature, catalyst type, which can enhance the kinetics for the reaction process, needs to be investigated further.

Pore properties, inner chemical environment, and microstructure of nano-modified CFA-WBP (class C fly ash-waste brick powder) based geopolymers

In order to study the influence of waste brick powder (WBP) and nano-modification on class C fly ash (CFA) based geopolymer, pore properties (i.e. bulk density, apparent porosity, and true porosity, and closed porosity) were tested according to the related Chinese National Standard, and the pore structure was also explored by mercury intrusion porosimetry (MIP); Water leaching procedure were performed to study the inner chemical environment; X-ray diffraction (XRD), Fourier transform infrared (FT-IR) and scanning electron microscope-energy dispersive X-ray spectroscopy (SEM-EDS) were measured to the microstructure and modification mechanism. The results show that WBP as additive results in a denser structure of geopolymer; nano-modification improves the pore structure, ameliorates the anti-leaching ability of geopolymer by constraining the soluble ions in gels, makes the geopolymerization more complete, and results in a denser paste structure by filling gaps between the particles with amounts of reaction products.

Heterogeneous Silica Tethered Ruthenium Catalysts for Carbon Sequestration Reaction

A series of silica-tethered Ru complexes were easily prepared and further analyzed by sophisticated analytical techniques such as FTIR, N2 physisorption, ICP-OES and XPS analysis. After proper characterization of catalyst structure, we exploited them to synthesize formic acid followed by CO2 hydrogenation reaction. To determine the exact amount of reaction product (formic acid) in the reaction mixture we performed the 1H NMR analysis, using dioxane as an internal slandered. No degradation of dioxane as well as the side product formation was recorded in this study. Reported catalytic systems were found active and stable in terms of formic acid formation and catalyst recycling experiment up to nine consecutive runs.

Pressure selected reactivity and kinetics deduced from photoinduced dissociation of ethylene glycol.

The photon-induced reactivity of liquid ethylene glycol (EG) was investigated in a diamond anvil cell at pressures up to ∼4 GPa and ambient temperature. The near-UV radiation at λ = 350 nm was employed to photodissociate EG via the two-photon absorption processes. The reaction evolution was monitored as a function of time and the reaction products were characterized by using in situ FTIR spectroscopy. At low initial loading pressures, the IR spectra show two distinctive sets of profile evaluations indicating sequential photoinduced chemical reactions, which are designated as primary and secondary photochemical processes, respectively. By careful examination of the characteristic IR bands and possible reaction pathways, over ten species as the primary and secondary reaction products were unambiguously identified. Significantly, we found that one of the photodissociation product CO2 forms specific clathrate hydrate structures or clusters that are both time- and pressure-dependent, indicating interesting and unique sequestration behavior of CO2 at high pressures. Quantitative analysis on selective reaction products allows detailed reaction kinetics involving competitive reaction channels to be probed. In particular, the type and quantity of reaction products as well as the kinetics were found highly pressure dependent. Moreover, the pressure variation of the system along the reaction progression allows the interpretation of possible reaction mechanisms of photodissociation of EG under high pressures.

Cementitious binders from activated stainless steel refining slag and the effect of alkali solutions

With an aim of producing high value cementitious binder, stainless steel refining slag containing a high amount of CaO in γ-dicalcium silicate form was activated with NaOH and Na-silicate as well as KOH and K-silicate solutions, followed by steam curing at 80°C. Higher levels of alkali–silicate in the activating solution resulted in higher cumulative heat suggesting accelerated reaction kinetics. With respect to compressive strength, higher levels of alkali silicate resulted in higher strength and the mortars with Na activator were found to have higher early strength than the ones with K activator. The long term strength was found to be similar, regardless of the alkali metal. Thermogravimetric, QXRD and FTIR analyses showed an increase in the amount of reaction products (CSH type) over time, further confirming the reactivity of the crystalline slag. Batch leaching results showed lower leaching of heavy metals and metalloids with K activator compared to the Na activator. These results demonstrate that the alkali type and the ratio of hydroxide to silicates have a significant impact on the hydration and mechanical strength development of the stainless steel slag. The above findings can aid in the recycling and valorization of these type of slags which otherwise end up landfilled.

Investigating the binding potential of continuous casting stainless steel slag by alkali activation

The aim of this work was to investigate the binding potential of non-hydraulic, crystalline continuous casting stainless steel slag, which is a by-product from stainless steel production, by alkali activation with sodium hydroxide and potassium hydroxide. Calorimetric analysis of the activated slag showed low cumulative heat evolution at 20°C. Slag mortars did not harden at this temperature. Considerable enhancements in heat evolution and hardening were observed at 80°C. The resulting hydrated slag showed the formation of calcium silicate hydrate type reaction products and brucite in thermogravimetric analysis. X-ray diffraction analysis showed a reduction in the amount of γ-dicalcium silicate and periclase. Elemental mapping showed the presence of calcium, silicon and minor amounts of magnesium in the hydrated phase. An optimum activator dosage of 7·5M of sodium hydroxide or potassium hydroxide was found to generate the highest amount of reaction products and compressive strength.

Ozonation of the reactive dye intermediate 2‐naphthylamine 3,6,8‐trisulphonic acid (K‐Acid): kinetic assessment, ozonation products and ecotoxicity

Ozonation of the commercially important, recalcitrant reactive dye intermediate 2‐naphthylamine 3,6,8‐trisulphonic acid (K‐Acid) was investigated. Ozonation performance was examined by following ozone absorption rates and K‐Acid, chemical oxygen demand and total organic carbon removals. Mean oxidation states and unidentified organic products were also determined. At pH 3, where direct ozone reactions are dominant, the second‐order rate constant between K‐Acid and molecular ozone was determined as 20 m−1 s−1 for steady‐state aqueous ozone concentration. The competition kinetics approach was also adopted where a reference compound, phenol, and K‐Acid were subjected to ozonation. By applying this method, the second‐order reaction rate constant was found to be 76 m−1 s−1. Common oxidation products formed during ozonation at pH 3, pH 7 and pH 7 with 1 mm hydrogen peroxide were identified as methoxy‐phenyl‐oxime, phenol, benzene, benzaldehyde and oxalic acid via high‐performance liquid chromatography and gas chromatography/mass spectrometry analyses. Continuous nitrate and sulphate evolution were observed during K‐Acid ozonation as a consequence of the abrupt release and subsequent oxidation of its amino and sulphonate groups. The number and amount of reaction products were most intensive for K‐Acid ozonation at pH 7 with 1 mm hydrogen peroxide. According to the acute toxicity tests conducted with Vibrio fischeri, ozonation products were not less toxic than the original K‐Acid solution that caused only 15% inhibition.

Propanil in a Manitoba soil: an interactive spreadsheet model based on conventional chemical kinetics

An interactive spreadsheet model has been created for quantitative predictions of propanil sorption and reaction in a slurried Manitoba clay soil. Based on experimental values for the numbers of empty and filled sorption sites as reactants and products, the reaction mechanism has been described with conventional chemical kinetics. The on line HPLC μ extraction method revealed labile sorption, intraparticle diffusion, and a chemical reaction. Laidler's integral rate law for second order kinetics describes the labile sorption. Desorption, intraparticle diffusion, and the chemical reaction are all described by first order kinetics. The time dependent effects of initial concentration and amount of slurried soil can be predicted for sorption, intraparticle diffusion, and the amount of reaction product. Suggested applications include storm runoff and inputs for fate and transport hydrology models.

Laser melt injection of ceramic particles in metals: processing, microstructure and properties

The objective of this paper is to present an overview of the possibilities of the laser melt injection (LMI) methodology to enhance the surface of light-weighted metals by adding hard ceramic particles in the top layer, with the aim to enhance the wear resistance and to increase the hardness. In particular, the LMI process and the resulted microstructures are exemplified on two material systems, i.e., SiC particles in Al and WC particles in Ti-6Al-4V. The microstructural response on loading of both systems is studied by in situ deformation tests and the microstructure is analysed in detail by advanced microscopy techniques such as scanning electron microscopy (SEM), transmission electron microscopy (TEM) and orientation imaging microscopy (OIM). It is shown that the LMI method is a suitable technique to create a MMC layers on metal substrates. The formation of reaction layers between the particles and the matrix may have a positive contribution on the bond strength between the particles and the matrix. However, the amount of reaction products in the matrix of the coatings should be minimised to improve the properties of the MMC layers.