Appearance, corrosion properties, and leach resistance of spruce and pine wood treated with Mea modified micronized copper preservative (MCu)

Abstract Canadian refractory wood species treated with micronized copper (MCu) wood preservative become mottled and streaky in appearance. To overcome this issue, the MCu system was modified by adding small amounts of monoethanolamine (Mea). The modified systems were evaluated to clarify the role of Mea in terms of leaching, corrosion, and mold resistance of MCu systems. The mottled and streaky surface on treated spruce was prevented at Mea/Cu molar ratios between 0.7 and 1.5. Copper leaching remained modest and was only slightly higher than that of MCu alone up to a Mea/Cu molar ratio of 1.2. However, adding even a small amount of Mea to the MCu formulation increased fastener corrosion compared with MCu. Protonated Mea increased as more Mea was added and was identified as the main corrosion-causing electrolyte in the system.

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The Control of the Reactions of Strontium Hexaferrite Formation by the Molar Ratio of Precursors

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.280-283.471 ◽

2007 ◽

Vol 280-283 ◽

pp. 471-472

Author(s):

S.A. Seyyed Ebrahimi

Keyword(s):

Critical Parameters ◽

Molar Ratio ◽

Strontium Hexaferrite ◽

Strontium Oxide ◽

Molar Ratios ◽

Temperature Method ◽

Wide Range ◽

Method Of Production ◽

Thermal Analysis Techniques

Strontium hexaferrite is one of the very important categories of magnetic materials with a wide range applications. One of the very critical parameters in the high temperature method of production of this material is molar ratio of iron oxide to strontium oxide. Although there could be found some reports on the effect of this parameter on the physical properties of the material in the literature but there are very few investigations about the role of this factor on the reactions occurred in the process. In this work the effect of different molar ratios of precursors on the reactions carried out for processing of strontium hexaferrite have been investigated by using thermal analysis techniques such as DTA/TG. Furthermore, the microstructure and the powder and bulk magnetic properties of the products have been studied by SEM, VSM and permeameter.

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Nickel and cobalt phosphides as effective catalysts for oxygen removal of dibenzofuran: role of contact time, hydrogen pressure and hydrogen/feed molar ratio

Catalysis Science & Technology ◽

10.1039/c5cy00282f ◽

2015 ◽

Vol 5 (6) ◽

pp. 3403-3415 ◽

Cited By ~ 33

Author(s):

A. Infantes-Molina ◽

E. Gralberg ◽

J. A. Cecilia ◽

Elisabetta Finocchio ◽

E. Rodríguez-Castellón

Keyword(s):

Catalytic Activity ◽

Contact Time ◽

Hydrogen Pressure ◽

Oxygen Removal ◽

Molar Ratio ◽

Metal Loading ◽

Molar Ratios ◽

Feed Molar Ratio

The catalytic activity of nickel and cobalt phosphides, with a metal loading of 5 wt.%, supported on silica was investigated in the hydrodeoxygenation reaction (HDO) of dibenzofuran (DBF) as a model oxygenated compound at different contact times, H2 pressures and H2/DBF molar ratios.

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Role of calcium ions and phospholipids in platelet aggregation and plug formation

American Journal of Physiology-Legacy Content ◽

10.1152/ajplegacy.1965.209.6.1128 ◽

1965 ◽

Vol 209 (6) ◽

pp. 1128-1136 ◽

Cited By ~ 11

Author(s):

Melvin J. Silver

Keyword(s):

Thrombus Formation ◽

Divalent Cations ◽

Adenosine Diphosphate ◽

Molar Ratio ◽

Triggering Mechanism ◽

Molar Ratios ◽

Phospholipid Micelles ◽

Plug Formation ◽

Aggregation Of Platelets

Certain phospholipids aggregate and form "plugs" in a simple system in which all variables are easily controlled. Aggregation requires the presence of divalent cations. Suspensions of lecithin are totally inactive whereas those of phosphatidylethanolamine and interaction products of lecithin and phosphatidylserine (molar ratio 1/1) aggregate and form plugs. Phosphatidylserine and lecithin-phosphatidylserine interaction products at higher molar ratios produce some aggregation but do not form plugs. Adenosine diphosphate (in the presence of small amounts of calcium) can accelerate the formation of small aggregates of platelets or exogenous phospholipids, but cannot bring about the formation of large aggregates or plugs. The hypothesis is presented that aggregation of platelets in physiological thrombus formation occurs after a triggering mechanism "uncovers" phospholipid micelles in platelets. The newly available negative charges on the polar ends of phospholipids would then be bridged by divalent cations present in the surrounding plasma, producing aggregates and plugs.

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The Role of Silica in the Chlorination–Volatilization of Cobalt Oxide by Using Calcium Chloride

Metals ◽

10.3390/met11122036 ◽

2021 ◽

Vol 11 (12) ◽

pp. 2036

Author(s):

Peiwei Han ◽

Zhengchen Li ◽

Xiang Liu ◽

Jingmin Yan ◽

Shufeng Ye

Keyword(s):

Cobalt Oxide ◽

Calcium Chloride ◽

Molar Ratio ◽

Molar Ratios

The role of silica in the chlorination–volatilization of cobalt oxide, using calcium chloride, is investigated in this paper. It is found that the Co volatilization percentage of the CoO–Fe2O3–CaCl2 system is not larger than 12.1%. Silica plays an important role in the chlorination–volatilization of cobalt oxide by using calcium chloride. In the CoO–SiO2–Fe2O3–CaCl2 system, the Co volatilization percentage is initially positively related to the molar ratio of SiO2 to CaCl2, and remains almost constant when the molar ratio of SiO2 to CaCl2 rises from zero to eight. The critical molar ratios of SiO2 to CaCl2 are 1 and 2 when the molar ratios of CaCl2 to CoO are 8.3 and 16.6, respectively. The Co volatilization percentage remains almost constant with the increase in CaO concentration, and decreases when Al2O3 and MgO are added. Ca2SiO3Cl2 is determined after roasting at 1073 K and 1173 K, and disappears at temperatures in excess of 1273 K in the calcines from the CoO–SiO2–CaCl2 system. CaSiO3 always exists in the calcines at temperatures in excess of 973 K.

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THE CATALYTIC ROLE OF BIRNESSITE IN THE TRANSFORMATION OF IRON

Canadian Journal of Soil Science ◽

10.4141/cjss87-050 ◽

1987 ◽

Vol 67 (3) ◽

pp. 533-543 ◽

Cited By ~ 16

Author(s):

G. S. R. KRISHNAMURTI ◽

P. M. HUANG

Keyword(s):

Key Words ◽

Infrared Absorption ◽

Molar Ratio ◽

Acidic Ph ◽

Chemical Analyses ◽

X Ray ◽

Molar Ratios ◽

Fe Oxides ◽

Catalytic Role

The influence of birnessite (δ-MnO2) on the precipitation products of iron was studied, in the FeCl2-NH4OH system at different Mn/Fe molar ratios (0, 0.01, 0.1 and 1.0) and in the acidic pH (4.0, 5.0 and 6.0) range, by X-ray, TEM, IR and chemical analyses. The precipitation products formed at pH 5.0 and 6.0 were found to be lepidocrocite (γ-FeOOH) in the absence of birnessite. Birnessite promoted increased precipitation of Fe oxide; the oxidation of Fe(II) by MnO2 was thermodynamically feasible and was confirmed by the presence of Mn(II) in the solution by ESR data. Birnessite also influenced the crystallization processes of hydrolytic products of Fe which range from lepidocrocite through goethite (α-FeOOH), akaganeite (β-FeOOH), to X-ray noncrystalline Fe oxides. The noncrystalline Fe oxides formed at a Mn/Fe molar ratio of 1.0 were characterized by infrared absorption maxima at 1400 and 750 cm−1. Key words: Birnessite, Fe(II) oxidation, ESR, lepidocrocite, akaganeite, noncrystalline oxide

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The underappreciated role of nonvolatile cations in aerosol ammonium-sulfate molar ratios

Atmospheric Chemistry and Physics ◽

10.5194/acp-18-17307-2018 ◽

2018 ◽

Vol 18 (23) ◽

pp. 17307-17323 ◽

Cited By ~ 18

Author(s):

Hongyu Guo ◽

Athanasios Nenes ◽

Rodney J. Weber

Keyword(s):

Gas Phase ◽

Ammonium Sulfate ◽

Fine Particle ◽

Organic Aerosol ◽

Molar Ratio ◽

Strongly Correlated ◽

Ammonia Gas ◽

Molar Ratios ◽

Aerosol Acidity

Abstract. Overprediction of fine-particle ammonium-sulfate molar ratios (R) by thermodynamic models is suggested as evidence for interactions with organic constituents that inhibit the equilibration of gas-phase ammonia with aerosol sulfate and questions the equilibrium assumption long thought to apply for submicron aerosol. This hypothesis is tested through thermodynamic analysis of ambient observations. We find that the deviation between R from a molar ratio of 2 is strongly correlated with the concentration of sodium (Na+), a nonvolatile cation (NVC), but exhibits no correlation to organic aerosol (OA) mass concentration or mass fraction. Thermodynamic predictions of both R and ammonia gas–particle partitioning can accurately reproduce observations when small amounts of NVCs are included in the calculations, whereas exclusion of NVCs results in a predicted R consistently near 2. The sensitivity of R to small amounts of NVCs arises because, when the latter are present but not included in the thermodynamic calculations, the missing cations are replaced with ammonium in the model (NH3–NH4+ equilibrium shifts to the particle), resulting in an R that is biased high. Results and conclusions based on bulk aerosol considerations that assume all species are internally mixed are not changed even if NVCs and sulfate are largely externally mixed; fine-particle pH is found to be much less sensitive to mixing state assumptions than molar ratios. We also show that the data used to support the “organic inhibition” of NH3 from equilibrium, when compared against other network and field campaign datasets, display a systematically and significantly lower NH4+ (thought to be from an evaporation bias), that is of the order of the effect postulated to be caused by organics. Altogether, these results question the postulated ability of organic compounds to considerably perturb aerosol acidity and prevent ammonia from achieving gas–particle equilibrium, at least for the locations considered. Furthermore, the results demonstrate the limitations of using molar ratios to infer aerosol properties or processes that depend on particle pH.

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Photocatalytic Reduction of CO2 to Methanol Using a Copper-Zirconia Imidazolate Framework

Catalysts ◽

10.3390/catal11030346 ◽

2021 ◽

Vol 11 (3) ◽

pp. 346

Author(s):

Sonam Goyal ◽

Maizatul Shima Shaharun ◽

Ganaga Suriya Jayabal ◽

Chong Fai Kait ◽

Bawadi Abdullah ◽

...

Keyword(s):

Photoelectron Spectroscopy ◽

Catalyst Support ◽

Oxidation Potential ◽

Molar Ratio ◽

X Ray Diffraction ◽

X Ray ◽

Molar Ratios ◽

Optimum Parameters ◽

Reduction Of Co2 ◽

Enhanced Yield

A set of novel photocatalysts, i.e., copper-zirconia imidazolate (CuZrIm) frameworks, were synthesized using different zirconia molar ratios (i.e., 0.5, 1, and 1.5 mmol). The photoreduction process of CO2 to methanol in a continuous-flow stirred photoreactor at pressure and temperature of 1 atm and 25 °C, respectively, was studied. The physicochemical properties of the synthesized catalysts were studied using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and photoluminescence (PL) spectroscopy. The highest methanol activity of 818.59 µmol/L.g was recorded when the CuZrIm1 catalyst with Cu/Zr/Im/NH4OH molar ratio of 2:1:4:2 (mmol/mmol/mmol/M) was employed. The enhanced yield is attributed to the presence of Cu2+ oxidation state and the uniformly dispersed active metals. The response surface methodology (RSM) was used to optimize the reaction parameters. The predicted results agreed well with the experimental ones with the correlation coefficient (R2) of 0.99. The optimization results showed that the highest methanol activity of 1054 µmol/L.g was recorded when the optimum parameters were employed, i.e., stirring rate (540 rpm), intensity of light (275 W/m2) and photocatalyst loading (1.3 g/L). The redox potential value for the CuZrIm1 shows that the reduction potential is −1.70 V and the oxidation potential is +1.28 V for the photoreduction of CO2 to methanol. The current work has established the potential utilization of the imidazolate framework as catalyst support for the photoreduction of CO2 to methanol.

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Lipozyme 435-Mediated Synthesis of Xylose Oleate in Methyl Ethyl Ketone

Molecules ◽

10.3390/molecules26113317 ◽

2021 ◽

Vol 26 (11) ◽

pp. 3317

Author(s):

Maria Carolina Pereira Gonçalves ◽

Jéssica Cristina Amaral ◽

Roberto Fernandez-Lafuente ◽

Ruy de Sousa Junior ◽

Paulo Waldir Tardioli

Keyword(s):

Oleic Acid ◽

Methyl Ethyl Ketone ◽

Molar Ratio ◽

Methyl Ethyl ◽

Sugar Ester ◽

Molar Ratios ◽

Emulsion Capacity ◽

Ping Pong ◽

Commercial Sugar ◽

Repeated Use

In this paper, we have performed the Lipozyme 435-catalyzed synthesis of xylose oleate in methyl ethyl ketone (MEK) from xylose and oleic acid. The effects of substrates’ molar ratios, reaction temperature, reaction time on esterification rates, and Lipozyme 435 reuse were studied. Results showed that an excess of oleic acid (xylose: oleic acid molar ratio of 1:5) significantly favored the reaction, yielding 98% of xylose conversion and 31% oleic acid conversion after 24 h-reaction (mainly to xylose mono- and dioleate, as confirmed by mass spectrometry). The highest Lipozyme 435 activities occurred between 55 and 70 °C. The predicted Ping Pong Bi Bi kinetic model fitted very well to the experimental data and there was no evidence of inhibitions in the range assessed. The reaction product was purified and presented an emulsion capacity close to that of a commercial sugar ester detergent. Finally, the repeated use of Lipozyme 435 showed a reduction in the reaction yields (by 48 and 19% in the xylose and oleic acid conversions, respectively), after ten 12 h-cycles.

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