Journal articles on the topic 'Non-wetting additives'
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1
Afshar, Saied, and Claude Allaire. "Furnaces: Improving low cement castables by non-wetting additives." JOM 53, no. 8 (August 2001): 24–27. http://dx.doi.org/10.1007/s11837-001-0130-8.
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Barandehfard, Faranak, James Aluha, AliReza Hekmat-Ardakan, and François Gitzhofer. "Improving Corrosion Resistance of Aluminosilicate Refractories towards Molten Al-Mg Alloy Using Non-Wetting Additives: A Short Review." Materials 13, no. 18 (September 14, 2020): 4078. http://dx.doi.org/10.3390/ma13184078.
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The corrosion of refractories in contact with high temperature aluminum-magnesium alloys leads to contamination of the Al-Mg alloy products by solid impurities from degraded refractories. Where both the spinel and corundum phases form in the refractories, cracks are generated and propagated by diffusion of molten Al-Mg, resulting in severe corrosion. In this review paper, the corrosion phenomenon is discussed, and published work is summarized, supplemented by our recent experimental results. Using the Alcan immersion test, materials based on white-fused mullite (WFM) were evaluated for their corrosion resistance and interfacial behavior. WFM was modified using different 2-wt.% of non-wetting additives (NWAs), such as BaSO4, CaF2, Secar®71 cement and wollastonite to improve their performance when in contact with molten Al-Mg alloy at 850 °C for 96 h. The mechanical properties of the samples such as flexural and compressive strength were evaluated, in addition to X-ray diffraction and microscopic analysis (optical and scanning electron microscopy coupled with X-ray elemental mapping). It was observed that cracks formed in samples were promoted with only BaSO4, CaF2, Secar®71 cement or wollastonite. However, cracks did not appear in the sample promoted with both 1-wt.% CaF2 and 1-wt.% BaSO4, because of improved anti-wetting properties in addition to inhibiting spinel (MgAl2O4) formation, which is the main cause of the cracks. This is a significant finding in the prevention of cracks and improvement of the refractory corrosion resistance.
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Naderi, Golsa, Hamid Reza Rezaie, Ali Shokuhfar, and Rahim Naghizadeh. "Effect of Colloidal Silica and Nano Boehmite Mixture on Reaction Sintering, Microstructure and Physical Properties of Tialite." Defect and Diffusion Forum 273-276 (February 2008): 554–59. http://dx.doi.org/10.4028/www.scientific.net/ddf.273-276.554.
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Aluminum titanate (Al2TiO5) is an engineering ceramic with low thermal expansion coefficient, excellent thermal shock resistance, good refractoriness and non-wetting with most metals. In this work the use of colloidal silica and nano boehmite mixture in proper stoichiometry of mullite in aluminum-titanate (tialite) has been studied. Analytical structural evaluations including XRD, TEM and SEM have been used to characterize the influence of these additives on phase transformation, sintering process and microstructure. The results show that the presence of nano size silica and boehmite enhanced the densification leads to fine microstructure, mullite phase formation and improve the tialite ceramics properties.
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Smith-Fiola, Deborah C., and Anne B. Gould. "EFFECTS OF A HYDROGEL, WETTING AGENT, AND METALAXYL ON PHYTOPHTHORA WILT IN CONTAINER-GROWN RHODODENDRON." HortScience 27, no. 6 (June 1992): 631a—631. http://dx.doi.org/10.21273/hortsci.27.6.631a.
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Phytophthora wilt, caused by the root-infecting fungus Phytophthora cinnamomi, is a serious disease of rhododendron. The symptoms of this disease include wilt, dieback, and death of nursery cuttings as well as large plants. The effects of two soil additives, Supersorb (a hygrogel) and Aquagro (a wetting agent), with and without Metalaxyl (Subdue 2E), were assessed on decreasing the incidence of Phytophthora wilt in container grown `Nova Zembla' rhododendron. Rooted cuttings grown in amended or non-amended mix were inoculated with P. cinnamomi. Metalaxyl treatments were applied once at the full label rate of 4 fl oz/100 gal at planting, or twice (at planting and 8 wks later) at 1 or 2 fl oz/100 gal. Trials were conducted from June to September in the greenhouse (1990) and outdoors (1991). Plant growth and disease incidence were evaluated weekly. In both trials, the Supersorb and Aquagro treatments did not affect disease incidence, although they did significantly affect plant growth. All metalaxyl treatments reduced disease incidence significantly when compared to controls.
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Scott, KJ, J. O'Loughlin, B. England, and EA Roberts. "Effects of water rinses after calcium chloride dips, with and without additives, on the control of bitter pit of apples." Australian Journal of Agricultural Research 36, no. 2 (1985): 305. http://dx.doi.org/10.1071/ar9850305.
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Studies on the control of bitter pit in apples after harvest were conducted during two seasons in Tasmania and New Zealand. The cultivars, Cox's Orange Pippin, Sturmer Pippin, Golden Delicious, Delicious and Cleopatra, which are susceptible to bitter pit on overseas markets, were examined. Bitter pit was reduced and calcium content of the fruit increased, by dipping the fruit in calcium chloride solutions (1-3% w/v). The addition of diphenylamine or the non-ionic wetting agent, Agral 60 (ICI Australia), had little effect on the control of bitter pit or on the calcium content of the treated fruit. Rinsing in water even 1 or 2 days after dipping did not significantly increase the incidence of bitter pit or lower the calcium content of the fruit. There was no difference in the incidence of bitter pit between fruit stored at ambient temperature (15-20�C) or at 3-5�C during the interval between dipping and rinsing. Dipping apples in calcium chloride followed, after 1 or more days, by a water rinse may be suitable commercially for reducing bitter pit in a number of cultivars.
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Squillace, Ophélie, Rebecca Fong, Oliver Shepherd, Jasmine Hind, James Tellam, Nina-Juliane Steinke, and Richard L. Thompson. "Influence of PVAc/PVA Hydrolysis on Additive Surface Activity." Polymers 12, no. 1 (January 14, 2020): 205. http://dx.doi.org/10.3390/polym12010205.
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This aims to establish design rules for the influence of complex polymer matrices on the surface properties of small molecules. Here, we consider the dependence of the surface behaviour of some model additives on polymer matrix hydrophobicity. With stoichiometric control over hydrolysis, we generate systematic changes in matrix chemistry from non-polar, hydrophobic PVAc to its hydrolysed and hydrophilic analogue, PVA. With the changing degree of hydrolysis (DH), the behaviour of additives can be switched in terms of compatibility and surface activity. Sorbitol, a polar sugar-alcohol of inherently high surface energy, blooms to the surface of PVAc, forming patchy domains on surfaces. With the increasing DH of the polymer matrix, its surface segregation decreases to the point where sorbitol acts as a homogeneously distributed plasticiser in PVA. Conversely, and despite its low surface energy, octanoic acid (OA) surprisingly causes the increased wettability of PVAc. We attribute these observations to the high compatibility of OA with PVAc and its ability to reorient upon exposure to water, presenting a hydrophilic COOH-rich surface. The surfactant sodium dodecyl sulfate (SDS) does not show such a clear dependence on the matrix and formed wetting layers over a wide range of DH. Interestingly, SDS appears to be most compatible with PVAc at intermediate DH, which is consistent with the amphiphilic nature of both species under these conditions. Thus, we show that the prediction of the segregation is not simple and depends on multiple factors including hydrophobicity, compatibility, blockiness, surface energy, and the mobility of the components.
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Przybyszewski, Bartlomiej, Anna Boczkowska, Rafal Kozera, Julio Mora, Paloma Garcia, Alina Aguero, and Ana Borras. "Hydrophobic and Icephobic Behaviour of Polyurethane-Based Nanocomposite Coatings." Coatings 9, no. 12 (December 2, 2019): 811. http://dx.doi.org/10.3390/coatings9120811.
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In this paper, hydrophobic nanocomposite coatings based on polyurethane (PUR) modified by nano-silica and silane-based compounds were manufactured by spraying. The main challenge was to assess and improve the hydrophobic as well as anti-icing properties of initially hydrophilic polymer coatings. The prepared nanocomposite coatings were characterized by means of scanning electron microscopy (SEM), optical profilometry and X-ray photoelectron spectroscopy (XPS). The results obtained showed that in order to achieve hydrophobicity, appropriate amounts of nano-silica must be incorporated in the coating, and complete coverage by nano-silica particles is necessary for achieving hydrophobicity. Coating adhesion and the durability of the hydrophobic behaviour were also studied by scratch test and frosting/defrosting cycles, respectively. The results show that use of both nano-silica and silane-based compounds improve the hydrophobic and anti-icing properties of the coating as compared to a non-modified PUR topcoat. A synergistic effect of both additives was observed. It was also found that the anti-icing behaviour does not necessarily correlate with surface roughness and the materials’ wetting properties.
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Patrykiejew, A. "Highly non-additive symmetric mixtures at a wall." Physical Chemistry Chemical Physics 20, no. 14 (2018): 9228–40. http://dx.doi.org/10.1039/c7cp07942g.
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Guzii, Sergii, Ihar Bazhelka, and Vasyl Lashchivskyi. "STUDY OF THE INFLUENCE OF COMPOUNDS OF THE ANO3 and ANO3 nH2O TYPES ON RHEOKINETIC AND COLLOID-CHEMICAL PROPERTIES OF ALUMINOSILICATE ADHESIVES FOR WOOD." ScienceRise, no. 5 (November 11, 2020): 14–23. http://dx.doi.org/10.21303/2313-8416.2020.001493.
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In the technology of gluing solid wood, various adhesives are used, which, in addition to ensuring the strength of the gluing, must also be characterized by a number of rheological and colloidal-chemical properties, namely: have acceptable viscosity, low contact angles, have good spreading and enveloping ability, penetrate deep into the wood , providing reliable cohesive-adhesive contact and much more. Today, adhesives based on PVA dispersions and urea formaldehydes are used, the properties of which have been sufficiently studied and tested in practice. An alternative to organic-based adhesives is mineral adhesives, in particular aluminosilicate adhesives, which are non-flammable and have high mechanical strength.
Object of research: rheokinetic patterns and processes of formation of colloidal-chemical structures of aluminosilicate adhesives modified with compounds of the ANO3 and ANO3×nH2O type.
Investigated problem: Considering that aluminosilicate adhesives are multiphase reactive suspensions, the viscosity of which changes over time and affects their viability, the issue of viscosity stabilization due to the introduction of electrolyte salts into their composition is relevant, and will also contribute to improving the wettability and spreading of the adhesive during applying them to substrates and gluing samples from various types of wood.
Main scientific results: The effect of the concentrations of compounds of the ANO3 and ANO3×nH2O type on the rheokinetic and chemical-colloidal properties of the aluminosilicate adhesive has been established, which will make it possible to use aluminosilicate adhesives in practice for gluing wood of various species, as well as to work out possible technological methods of their application, taking into account the obtained data on the viscosity, wetting and spreadability of the modified adhesive on the surface of the wood substrate.
Area of practical use of the research results: woodworking enterprises for the production of glued solid wood products.
Innovative technological product: aluminosilicate adhesives modified with ANO3 and ANO3×nH2O nitrate additives for gluing wood of various species.
Scope of application of an innovative technological product: the application of these approaches will make it possible to obtain glued materials from wood from different species with improved technological and physical and mechanical properties of the glue seam and, accordingly, to increase the quality and reliability of products.
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Kovalchuk, Nina M., Jacques Dunn, Jack Davies, and Mark J. H. Simmons. "Superspreading on Hydrophobic Substrates: Effect of Glycerol Additive." Colloids and Interfaces 3, no. 2 (May 31, 2019): 51. http://dx.doi.org/10.3390/colloids3020051.
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The spreading of solutions of three trisiloxane surfactants on two hydrophobic substrates, polyethylene and polyvinylidenefluoride, was studied with the addition of 0–40 mass % of glycerol. It was found that all the surfactant solutions spread faster than silicone oil of the same viscosity, confirming the existence of a mechanism which accelerates the spreading of the surfactant solutions. For the non-superspreading surfactant, BT-233, addition of glycerol improved the spreading performance on polyvinylidenefluoride and resulted in a transition from partial to complete wetting on polyethylene. The fastest spreading was observed for BT-233 at a concentration of 2.5 g/L, independent of glycerol content. For the superspreading surfactants, BT-240 and BT-278, the concentration at which the fastest spreading occurs systematically increased with concentration of glycerol on both substrates from 1.25 g/L for solutions in water to 10 g/L for solutions in 40% glycerol/water mixture. Thus, the surfactant equilibration rate (and therefore formation of surface tension gradients) and Marangoni flow are important components of a superspreading mechanism. De-wetting of the solutions containing glycerol, once spread on the substrates, resulted in the formation of circular drop patterns. This is in contrast to the solely aqueous solutions where the spread film shrank due to evaporation, without any visible traces being left behind.
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Gur’ev, Vladimir, Vadim Nikitin, and Valeriy Kofanov. "INVESTIGATION OF HEAT-HUMIDITY TRANSFER IN HIGH-POROUS GAS-FILLED POLYMERS TO CALCULATE ITS HEAT CONDUCTIVITY." International Journal for Computational Civil and Structural Engineering 15, no. 1 (March 25, 2019): 67–77. http://dx.doi.org/10.22337/2587-9618-2019-15-1-67-77.
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A method for calculating the effective thermal conductivity of moisture-containing highly porous foamed polymers is proposed. In this method a non-additive scheme for taking into account the effect of steam diffusion on heat transfer is used. The sequential binary systems (interstitial substance from a liquid and a vapor- gas mixture, as well as a polymer skeleton and an intra-porous substance) are described by models of structures with interpenetrating components and isolated inclusions. The conditions for the transition from one model of structure to another are defined and there is not necessity to define empirical coefficients. A geometric model of wet foamed polymer has been developed, that allows us to find a way to determine the value of the boundary moisture content of pores or wetting angle at which the transition from partial wetting of the surface of the pores with liquid to full wetting and vice versa occurs. A mathematical description of the process of heat transfer in the model structure of a wet foamed polymer has been made, taking into account the diffusion of water vapor in the pore space.
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Osburg, Andrea, Alexander Gypser, and Martin Ulrich. "Development of Polymer Concrete with Non-Standardised Fillers for Innovative Building Materials." Advanced Materials Research 1129 (November 2015): 484–91. http://dx.doi.org/10.4028/www.scientific.net/amr.1129.484.
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The use of polymer concrete in building construction is a relatively new application. A building block system (Modular Assembly System: MAS-System) and the mobile fabrication technology for the reversible construction of buildings with regionally available aggregates, were developed in a project of applied research. The aspects of the successful material development are described, especially with regard to the characterisation of both the binders and the polymer concretes, considering strength and durability. The polymer concrete consists approximately of 90 % fillers, 10 % polymer binder and additives. The investigation of the binder-system included the determination of gel time and temperature development, shrinkage, wetting of formwork materials and immersion tests with marine water. The aim was an adaptation and optimisation of the binder system. The characterisation of mechanical properties of the polymer concrete was realised by determining its strength in a temperature range between - 40 °C and 60 °C. Compression tests on wall segments were also realised. Ageing is an important aspect of the durability of polymer bonded materials. Special tests were used for an accelerated ageing, including impacts of temperature change, cold rain water and natural radiation.
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Tarapanov, Alexander S., Larisa Y. Frolenkova, and Tatyana N. Shablinskaia. "The Roughness of the Contact Surfaces of Plastic Cylindrical Gears with a Circular Tooth during Additive Shaping." Materials Science Forum 989 (May 2020): 833–38. http://dx.doi.org/10.4028/www.scientific.net/msf.989.833.
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The article discusses the problems of using FDM technologies in the formation of plastic gears with circular teeth. It is shown that additive technologies are becoming increasingly important in the manufacture of non-standard parts. The role of such an important parameter as the roughness of the side surface of the teeth, which has a significant impact on the durability of gearing, is emphasized. The method for calculating the configuration of liquefied material layer on a solid flat surface is proposed. This method is based on a model of the interaction of the internal three-dimensional state of liquid material layer, a two-dimensional material film, and a material line closing it. The state and shape of the liquid layer on a flat surface was analyzed under the assumption of the validity of the Yungi equation, connecting the wetting angle with the values of surface tensions. The dependences, allowing calculating the amount of irregularities of the lateral surface of the circular teeth of plastic cylindrical gears, are given.
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Wemmer, Judith, Loredana Malafronte, Socrates Foschini, Aline Schneider, Christian M. Schlepütz, Martin E. Leser, Martin Michel, Adam Burbigde, and Erich J. Windhab. "Fabrication of a Novel Protein Sponge with Dual-Scale Porosity and Mixed Wettability Using a Clean and Versatile Microwave-Based Process." Materials 14, no. 9 (April 29, 2021): 2298. http://dx.doi.org/10.3390/ma14092298.
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An open-porous protein sponge with mixed wettability is presented made entirely from whey proteins and with promising applications in biomedicine, pharmaceutical, and food industry. The fabrication relies on an additive-free, clean and scalable process consisting of foaming followed by controlled microwave-convection drying. Volumetric heating throughout the matrix induced by microwaves causes fast expansion and elongation of the foam bubbles, retards crust formation and promotes early protein denaturation. These effects counteract collapse and shrinkage typically encountered in convection drying of foams. The interplay of high protein content, tailored gas incorporation and controlled drying result in a dried structure with dual-scale porosity composed of open macroscopic elongated foam bubbles and microscopic pores in the surrounding solid lamellae induced by water evaporation. Due to the insolubility and mixed wettability of the denatured protein network, polar and non-polar liquids are rapidly absorbed into the interconnected capillary system of the sponge without disintegrating. While non-watery liquids penetrate the pores by capillary suction, water diffuses also into the stiff protein matrix, inducing swelling and softening. Consequently, the water-filled soft sponge can be emptied by compression and re-absorbs any wetting liquid into the free capillary space.
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Doerffel, Christoph, Raik Schmidt, Mirko Spieler, Wolfgang Nendel, Lothar Kroll, Jens Petzold, David Schreiter, and Mathias Hunold. "Generating Permanent and Temporary Material Compounds in FLM Processes." Key Engineering Materials 809 (June 2019): 353–59. http://dx.doi.org/10.4028/www.scientific.net/kem.809.353.
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Like all additive manufactured parts, FLM (fused-layer-modeling) components are characterized by a large number of joints between the similar and different materials. These joints can be divided into five categories:- Permanent cohesive bonds between single layers of the same thermoplastic material,- Permanent adhesive bonds between single layers of different thermoplastic materials- Temporary adhesive bonds between single layers of different thermoplastic materials,- Permanent adhesive bonds between a single layer of thermoplastic material and a non-thermoplastic base material,- Temporary adhesive bonds between a single layer of thermoplastic material and a non-thermoplastic base material.The first three types of bonds describe the binding process when parts are manufactured of base material, a second permanently bonded component or a support material that has good release properties. The last two types of connection describe the permanent connection between the printing part and a non-FLM-component or the temporary joint between the printed part and the build platform during the printing process. The resulting compounds can be characterized as material compounds.Since the FLM process is mainly used for design and hobby applications, the fundamentals of the bonding processes and their influence on the internal structure of the material are hardly described. Some information can be taken from the literature for welding plastics and the production of hybrid parts by injection molding. Due to the different pressure and temperature conditions as well as the very large surface-volume-ratio of the discharged strand occur significant differences in the following factors: melt flow, solidification time, formation of surface layers and wetting of the surfaces.The investigation and characterization of these effects as a function of external process parameters is an important constituent for the further development of the FLM process into an industrially suitable manufacturing process for thermoplastic components with very high lightweight and complex geometry in small series etc.
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Nelson, P. N., J. A. Baldock, and J. M. Oades. "Changes in dispersible clay content, organic carbon content, and electrolyte composition following incubation of sodic soil." Soil Research 36, no. 6 (1998): 883. http://dx.doi.org/10.1071/s98024.
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Measurement of dispersible clay is important for the diagnosis of structural stability problems in soil. However, clay dispersibility is known to change with water content and time. The purpose of the present study was to determine how incubation of sodic soil under different water content regimes influences clay dispersibility. Two topsoils (depth 0-0·1 m), one sodic [exchangeable sodium percentage (ESP) 9 · 7] and the other non-sodic (ESP 3·8), were collected from an experimental pasture at Kyabram, Victoria, and 2 soils, a sodic topsoil (depth 0-0·1 m, ESP 6·9) and the corresponding subsoil (depth 0·2-0 m, ESP 25·7), were collected from a cropped field at Two Wells, South Australia. The soils were incubated for 264 days in a split-plot design. The main treatments were soil type and incubation water content: continuously air-dry, continuously wet (-50 kPa), or with wet/dry cycles. The subtreatment was water content at analysis: air dry or wet (-50 kPa). Clay dispersion was greater when measured on wet soils than dry soils, irrespective of water contents during the prior incubation. Electrical conductivity increased, and sodium adsorption ratio (SAR), pH, and organic carbon content decreased as a function of the time for which the soils were wet. In the Kyabram soils that were wet when analysed, easily dispersible clay content increased with SAR. Decreases in moderately dispersible clay under the wetting/drying regime were not related to electrolyte composition, and were attributed to particle rearrangement and cementation. The decreases in clay dispersibility with time occurred despite net losses of carbohydrate and aliphatic materials. An implication of the work is that the decomposition of soil organic matter, even in the absence of fresh additions, may reduce clay dispersion in sodic soils by altering electrolyte concentration and composition.
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Kowalenko, C. G., and S. Yu. "Solution, exchangeable and clay-fixed ammonium in south coast British Columbia soils." Canadian Journal of Soil Science 76, no. 4 (November 1, 1996): 473–83. http://dx.doi.org/10.4141/cjss96-059.
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Solution, exchangeable and clay-fixed ammonium were measured in a variety of south coast British Columbia soils in the laboratory using extraction, equilibration and leaching procedures, and with and without ammonium amendments in order to evaluate the relative significance of adsorption and fixation processes on nitrogen behavior. Non-amended soils contained from 59 to 224 g N g−1 of fixed ammonium and these amounts were correlated with clay (positive) and sand (negative) contents. The amount of native fixed ammonium in the soils was influenced by management history. Recovery of ammonium added to eight selected samples by a small volume of solution followed by air drying was the same with 1 and 2 M KCl extractions, but less was extracted by 0.1 M KCl and even less by water. This showed that both 1 and 2 M KCl had sufficient K+ to displace the NH4+ present (inherent and added) on the exchange sites without an apparent effect on fixed ammonium. Up to 68% of the ammonium added was not extracted by 2 M KCl and assumed to have been fixed in the clay lattice. The proportion of the added ammonium that was adsorbed onto the exchange sites was linear up to 200 μg N g−1 application, but the amount fixed by the clays was linear to only about 100 μg N g−1 application rate. Data from studies where soil columns were leached with NH4NO3 provided only limited information on the relative importance of exchange versus fixation processes to the adsorption of ammonium. Leaching columns with a limited number of batches of NH4NO3 followed by water (short cycle) were useful for comparing the ability of different soils to adsorb and retain ammonium, but the relative importance of exchange versus fixation could not be determined. In the 18 samples of this study, the amount of NH4+ adsorbed ranged from 84 to 25% during short cycle column leachings. Different patterns of adsorption occurred among the four soil samples that were leached with a large number of batches of ammonium (long cycle), but it could not be determined whether or not these patterns were related to differences in proportions of fixation relative to exchange. Measurements showed that ammonium was fixed in the soils during the long cycle leachings but that the amounts of fixed ammonium measured were influenced by air drying the sample before analysis. Several studies with and without toluene additions showed that microbial activity must be controlled during these measurements. It was concluded that south coastal soils contained significant amounts of fixed ammonium and can fix additional ammonium. The amount of ammonium in the clay fixed pool and the potential to fix added ammonium was different in relation to the soil type, their previous management, and wetting and drying cycles. The biological significance of fixed ammonium and the fixation process must not be discounted in any nitrogen studies of these soils for proper interpretation of data. Key words: Ammonium fixation, equilibration, column leaching, microbial/enzyme inhibition, extractant concentration
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"Evaluation of Noble Environmentally Friendly and High Efficient Fire-Extinguishing Means." Journal of Chemistry: Education Research and Practice 4, no. 2 (May 15, 2020). http://dx.doi.org/10.33140/jcerp.04.02.02.
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Reviewing the history of the development of preventing measures, to ensure suppression of fire clearly reveals, that the most urgent of these measures is the use of environmentally friendly, highly efficiency fire extinguishing means. The best fire-extinguishing means are fire-extinguishing powders, which are characterized by high effectiveness and universality. Fire- extinguishing powders of serial production represents the fine dispersed mineral salts with different additives, which decrease tendency of consolidation and caking of powder. In serial production powders halogen containing, organic hydrophobizators are mainly used as such additives. Thus, most of them are halogen containing and do not satisfy the contemporary demands, in the first place with the view of effective, non-toxic and universal use. It also should be mentioned, that fire- extinguishing powders are characterized with less heat capacity, low permeability and wetting effect compared to water and foams, that’s why at extinguishing large scale fires, particularly - forest fires, use of just fire- extinguishing powders is less effective. This article discusses the elaboration of non-halogen, environmentally friendly, high-efficient, universal fireextinguishing powders on the basis of local mineral raw materials of silicate origin and production of highly effective foam-suspensions based on such powders, the use of which will have higher extinguishing ability than water, foams or powders taken separately. The received fire-extinguishing powders will be used at extinguishing of all classes of fires, as well as, in complex with water and foams for extinguishing of large scale fires – forest fires.
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Economikos, Laertis, Xing Zhang, Haigou Hwang, Unoh Kwon, Keith Wong, Yann Escarabajal, Uma R. K. Lagudu, Ashwin Chockalingam, and S. V. Babu. "Al CMP for Low Resistance Gate Fill for 20nm and Beyond Replacement Metal Gate." MRS Proceedings 1560 (2013). http://dx.doi.org/10.1557/opl.2013.873.
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ABSTRACTAluminum (Al) gate fill has been implemented in Replacement Metal Gate (RMG) due to its low resistivity. Titanium (Ti) has been widely used as wetting layer for Al to fill the gates. For low resistance gate fill in structures with small feature size and high aspect ratio, Ti-Al metal fill becomes increasingly more challenging as we move from 20nm into 14nm FinFET and 3D type structures.Cobalt (Co) is a good wetting film for Al with better fill performance and lower resistance than Ti-Al based process. However, due to the difference in corrosion potential between Al and Co, Chemical Mechanical Planarization (CMP) creates pitting type defects on Al-Co film that increases resistance variability across pattern density. CMP induced corrosion is separated in two parts; first is the static Co corrosion happened in the acidic chemical environment in the Al slurry. Second is the galvanic corrosion from Co-Al metal boundary due to high metal electrical potential. Static corrosion can be resolved by adding a Co corrosion inhibitor in the slurry formulation1. Galvanic corrosion can be minimized by controlling Co thickness deposition and formation of complete intermetallic phase. By controlling the removal rate with respect to corrosion rate we were able to suppress corrosion significantly.We looked into compositions where the corrosion potential (Ecorr) gap between Al and Co is reduced to ≤10mV leading to reduced galvanic currents. Stabilization of the corrosion currents in both Al and Co was observed using potentiodynamic scans. The effect of pH, several oxidizers and additives on the open circuit potentials (Eoc) of Al and Co was investigated and it was found that solutions of KMnO4, saccharides and sulfonate group containing compounds help reduce the Ecorr gap in between Al and Co to ∼10 mV.Controlling the Al gate height across pattern densities and gate lengths to within few nm is another challenge for Al CMP. The industry widely used approach is to clear all Al using a slurry with high selectivity to dielectric, followed by a CMP step using a non-selective Al-to-oxide slurry. Both polishing steps need to be optimized in parallel in order to remove the incoming spacer SiN divot, minimize Al loss on gates with high pattern density or long gate length, minimize oxide loss on large open areas while maintaining low defectivity.In this paper we are presenting an innovate Al CMP process that demonstrated low gate resistance with tight distribution up to 80% pattern density. This work has been supported by the independent Bulk CMOS and SOI technology development projects at the IBM Microelectronics Division Semiconductor Research & Development Center, Hopewell Junction, NY 12533.
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Patrykiejew, Andrzej. "The interplay between wetting and demixing in non-additive symmetric mixtures at selective walls." European Physical Journal B 91, no. 10 (October 2018). http://dx.doi.org/10.1140/epjb/e2018-90304-5.
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V., Merlin, Kritsalis P., Coudurier L., and Eustathopoulos N. "Thermodynamic Factors Governing Interfacial Chemistry And Wetting In Binary Alloy-Refractory Oxide Systems." MRS Proceedings 238 (1991). http://dx.doi.org/10.1557/proc-238-511.
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ABSTRACTFor a given non-reactive metal M- refractory oxide system, the influence of a metallic solute A on interfacial chemistry and wetting depends mainly on the value of εO−A the Wagner interaction parameter which quantifies the solute A-solute oxygen interactions in the liquid matrix M.For εO−A < 0 (moderate attraction between solutes A and O) additions of A in M enhance dissolution of oxide in the liquid alloy, thereby increasing the dissolved oxygen content. The O-A clusters formed are adsorbed at the metal-oxide interface leading to an increase in both wettability and adhesion energy. For εO−A ≪0 (strong A-O interactions), solute A can also form an oxide by reduction of the substrate. The more metallic in character this oxide is, the more wettable it will be by molten metal.
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Ehsan Kianfar. "An Experimental Study PVDF and PSF Hollow Fiber Membranes for Chemical Absorption Carbon Dioxide." Fine Chemical Engineering, September 8, 2020, 91–102. http://dx.doi.org/10.37256/fce.122020552.
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Poly (vinylidene fluoride) (PVDF) and poly-sulfone (PSF) polymer solutions were made at a concentration of 18% by weight of the polymer as a non-soluble additive of polymer solution in 1-methyl-2-pyrrolidone (NMP) solvent. PVDF and PSF hollow fiber membranes were fabricated via the wet phase-inversion process. Fabricated membranes were characterized in terms of gas permeability, wetting resistance, water contact angle and overall porosity. In order to study the structure of the membranes made, the scanning electron microscopy images of the model (TM3000, HITACHI, Japan) were used. The morphology study indicates that the PSF membrane shows an open cross-section structure with smaller pore sizes. However, the PVDF membrane illustrates a thick sponge-like structure. The fabricated PVDF membrane shows higher wetting resistance, surface porosity, water contact angle, and N2 permeability. The performance of the produced membranes was examined for the Absorption of carbon dioxide in a gas-liquid contactor membrane through the solution of mono-ethanolamine (MEA). The results show that CO2 absorption flux of the PVDF hollow fiber membrane is higher than PSF hollow fiber membrane. The maximum CO2 absorption flux of 8.10 × 10-3 (mole/m2 s) at the liquid phase flow rate of 300 ml/min for PVDF hollow fiber membrane was achieved and also the maximum CO2 absorption flux of 6.50 × 10-3 (mole/m2 s) at the liquid phase flow rate of 300 ml/min for PSF hollow fiber membrane was obtained. It can be concluded that a porous hydrophobic hollow fiber membrane with high surface porosity and high gas permeability can be a productive alternative for CO2 absorption through gas-liquid membrane contactors.
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Fizer, O. I., I. A. Kryvoviaz, M. M. Fizer, and M. V. Slivka. "CALCULATION OF HYDROPHILIC-LIPOPHILIC BALANCE FOR THE SYSTEM OF 2,3-SUBSTITUTED-5,6-DIHYDRO-3H-[1,3]THIAZOLO[3,2-b][1,2,4]TRIAZOL-7-IUM." Scientific Bulletin of the Uzhhorod University. Series «Chemistry» 45, no. 1 (June 30, 2021). http://dx.doi.org/10.24144/2414-0260.2021.1.77-82.
Full textAbstract:
Cationic surfactants are widely used in industry, medicine, and in studies of a number of physicochemical processes. Analysis of the literature data indicates the high biological activity of cationic surfactants, particularly antimicrobial, antifungal, and in general biocidal. Currently, QSPR methods are increasingly used; they allow the prediction of properties based on the compound's molecular structure. One of the important parameters of cationic surfactants is the ratio of polar (positively charged "head") and non-polar (long hydrocarbon "tail") parts of their molecules. This ratio is called hydrophilic-lipophilic balance (HLB). In 1949, Griffin and Davis developed HLB scales of colloidal surfactants, according to which the HLB parameter can take values in the range from 1 (the substance is insoluble in water but soluble in nonpolar liquids) to 40 (the substance is soluble in water and insoluble in nonpolar liquids) conventional units. Given the complexity of the experimental determination of HLB, mathematical additive models for its calculation were developed.
In our previous studies, methods for the synthesis of cationic 1,2,4-triazolium systems, including cationic surfactants based on 1,3-thiazolo-1,2,4-triazole condensed nucleus, were developed. Thus, 2,3-substituted-5,6-dihydro-3H-[1,3]thiazolo[3,2-b][1,2,4]triazol-7-ium were selected as model objects in this study.
The construction of model compounds was performed in the Avogadro program with subsequent optimization of the geometry using the force field MMFF94. The HLB index was calculated by three methods: Griffin, Davis, and the ratio of polar and nonpolar areas on the isosurface of the molecule using the software package Vega ZZ.
Simple approach for calculating HLB based on the number of carbon atoms in long alkyl substituents have been established. HLB values are the largest when calculating the ratio of polar and non-polar parts of the molecule. The calculated values of HLB vary in a wide range, which allows referring the investigated systems to emulsifiers "oil/water" (for short alkyl chains C1–C4), wetting agents (for short alkyl chains C1–C5), emulsifiers "water/oil" (for alkyl chains C5–C20), antifoams (for alkyl chains C18–C20).