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Properties of the Elements and Inorganic Compounds
Published in W. M. Haynes, David R. Lide, Thomas J. Bruno, CRC Handbook of Chemistry and Physics, 2016
W. M. Haynes, David R. Lide, Thomas J. Bruno
Calcium hydrogen phosphate Calcium hydrogen phosphate dihydrate Calcium hydrogen sulfite Calcium hydrosulfide hexahydrate Calcium hydroxide Calcium hydroxide phosphate Calcium hypochlorite Calcium hypophosphite Calcium iodate Calcium iodide Calcium iodide hexahydrate Calcium metaborate Calcium metasilicate Calcium molybdate Calcium nitrate Calcium nitrate tetrahydrate Calcium nitride Calcium nitrite Calcium nitrite monohydrate Calcium oleate Calcium oxalate Calcium oxalate monohydrate Calcium oxide Calcium oxide silicate Calcium palmitate Calcium 2,4-pentanedioate Calcium perborate heptahydrate Calcium perchlorate Calcium perchlorate tetrahydrate Calcium permanganate Calcium peroxide Calcium phosphate Calcium phosphide Calcium phosphonate monohydrate Calcium plumbate Calcium propanoate Calcium pyrophosphate Calcium selenate dihydrate Calcium selenide Calcium silicide (CaSi) Calcium silicide [CaSi2] Calcium stannate trihydrate Calcium stearate Calcium succinate trihydrate Calcium sulfate Calcium sulfate dihydrate Calcium sulfate hemihydrate Calcium sulfide Calcium sulfite dihydrate Calcium tartrate tetrahydrate Calcium telluride Calcium tetrahydroaluminate Calcium thiocyanate tetrahydrate Calcium thiosulfate hexahydrate Calcium titanate Calcium tungstate Calcium zirconate Californium
Optimising the corrosion performance of hot-rolled steel bar in concrete
Published in Corrosion Engineering, Science and Technology, 2022
Qinghai Zhou, Yanbin Yin, Zhiming Liu, Jiongming Zhang
Many studies have been carried out to investigate the corrosion problem. Dan studied the corrosion behaviour of Cr micro-alloyed rebar in an enclosed environment and showed that the corrosion resistance was improved due to the solid solution of Cr micro-alloyed in the ferrite grains [7]. Liu estimated the corrosion resistance of low-alloy steels and HRB400 carbon steel in simulated concrete pore solution, which showed that the Cr-modified steels exhibited a higher corrosion resistance than carbon steel [8]. Hao discussed the alloying effect of Mn, Cu and P elements on the anti-corrosion mechanism of MnCuP weathering steel [9]. Wang showed that the corrosion rate of weathering steel was slower compared with carbon steel due to the alloying additions of Cr, Cu, P and Ni [10]. Cheng estimated the corrosion behaviour of nickel-containing weathering steel in a simulated marine atmospheric environment [11]. Yogesh studied the electroplating of bright Zn–Ni alloy steel and found that when the electrodeposits had about 3.1% Ni, steel showed good performance against corrosion. It was observed that the samples immersed in the pore solution with calcium nitride-based inhibitor in the presence of oxygen had no signs of corrosion for the chloride concentration [12]. Gunaselvi modified the surface of the steel by electroless nickel coating using three different thicknesses and evaluated the efficiency of the corrosion resistance properties of 10, 20 and 30 μm coated steel [13]. Singh studied the electroless nickel-phosphorus (ENP) coatings to protect rebars from chloride-induced corrosion. It was observed that ENP deposited at a pH of 4.00 attained a slow corrosion rate. The coatings deposited at higher pH, however, showed a high corrosion rate [14]. Bethencourt modified the surface of the steel with an inhibitor [15].
A sequential multistep process for the fully mechanochemical, one-pot synthesis of the antiepileptic drug rufinamide
Published in Green Chemistry Letters and Reviews, 2022
Jorge Gómez-Carpintero, Clara Cabrero, Juan Domingo Sánchez, Juan Francisco González, José Carlos Menéndez
Following azidation/CuAAC optimization, we studied the full three-step azidation/CuAAC/amidation sequence in a one-pot process. We started the study by the screening of ammonia sources from ammonium formate, ammonium chloride, ammonium acetate, magnesium nitride and calcium nitride. Thus, the first two steps were carried out under the conditions previously optimized and stoichiometric amounts of the different ammonium salts were used in the last step, leading only to triazole 2 in all cases, together with unidentified side products. However, when the reaction was performed with the Mg3N2/MeOH or Ca3N2/MeOH systems in the presence of indium trichloride as a catalyst, rufinamide was obtained with an excellent conversion after 90-min milling in the final step. While both reactions gave similar results, the work-up was simpler for the case of Ca3N2, since the formation of emulsions due to the presence of magnesium salts was prevented. Under these conditions, the reaction mixture was easily purified by simple extraction followed by recrystallization from ethanol–water, without the need for purification by column chromatography, giving rufinamide in 40% overall yield. It is interesting to note that in previous work the mechanochemical amidation of esters with nitride salts had required the presence of indium trichloride as a Lewis acid catalyst (18), whose role is presumably played here by a copper species generated in the second reaction. In an effort to improve the outcome of the process, we added indium trichloride at the last step and obtained a slight increase in yield to 45% (Figure 3). Nevertheless, bearing in mind that the overall process comprises three reactions that generate four new bonds, an overall yield of 45% corresponds to about 77% for each individual step. Moreover, some loss of material probably took place during the final isolation step, since crystallization is usually less efficient (although greener) than chromatography.