The System Sodium Chromate—Sodium Molybdate—Water

1945 ◽  
Vol 67 (2) ◽  
pp. 262-268 ◽  
Author(s):  
William E. Cadbury

2021 ◽  
Vol 892 ◽  
pp. 115-123
Author(s):  
Viktor Malau ◽  
Wisnu Hakiki

Piping systems at gathering stations in the oil and gas industries often fail due to corrosion attacks from the brine water solution containing 8% NaCl that flows through the system. This solution is highly corrosive on the API 5L grade B steel pipes, thereby shortening its lifespan, with an increase in the frequency of pipe replacements. However, the corrosion resistance of API 5L grade B pipes can be improved by using chromate and molybdate inhibitors. Therefore, the objective of this research is to improve the corrosion resistance of the steel pipes using sodium chromate (Na2CrO4) and sodium molybdate (Na2MoO4) inhibitors with concentrations of 0.2, 0.4, 0.6, 0.8 and 1,0%. This research also aim to determine the optimum concentration of inhibitors to produce minimum corrosion rate, by testing the brine water solution containing 8% NaCl through the potentiodynamic polarization method. The results show that generally, the addition of sodium chromate and sodium molybdate inhibitors to the brine solution causes the steel pipes to be more resistant to corrosion. Furthermore, the sodium chromate inhibitor concentration of 0.6% produces the greatest corrosion potential of – 400 mV with the lowest rate of 0.38 mpy, while sodium molybdate concentration of 0.4% produces the highest corrosion potential of – 385 mV with the lowest rate of 0.34 mpy. The results of SEM observations at 0.4% sodium molybdate concentration showed that the corrosion inhibition/passivation effect of the inhibitor made the steel surface smoother, while the sodium chromate inhibitor at similar percentage failed to reach the optimal concentration to inhibit the corrosion process.



1992 ◽  
Vol 263 (5) ◽  
pp. E943-E949 ◽  
Author(s):  
S. Y. Hsu ◽  
F. W. Goetz

The present study investigated the effects of a number of oxoanion compounds on in vitro ovulation of goldfish follicles and ovarian second messenger activities. Significant levels of ovulation were induced by 0.1 mM sodium chromate, 0.1 mM sodium metavanadate, 10 mM sodium molybdate, 0.1 mM sodium orthovanadate, 5 mM sodium selenate, 0.5 mM sodium tungstate, and 0.1 mM vanadyl sulfate. At levels that significantly stimulated ovulation, metavanadate, molybdate, orthovanadate, tungstate, and vanadyl sulfate also stimulated follicular phosphatidylinositol cycling and inhibited ovarian alkaline phosphatase activity. Moreover, the ovulation induced by these oxoanions was not inhibited by indomethacin (10 micrograms/ml), while ovulation induced by selenate and chromate was. In contrast, only vanadium-containing compounds significantly stimulated prostaglandin (PG) synthesis, and, in fact, selenate significantly inhibited PG production. Finally, only sodium molybdate- and vanadium-containing compounds appeared to increase follicular adenosine 3',5'-cyclic monophosphate content. While all oxoanions stimulated in vitro ovulation, they had differential effects on certain signal transduction pathways when tested at concentrations that stimulated in vitro ovulation. From the results, two basic groups could be delineated, one containing tungstate-, molybdate-, and vanadium-containing compounds and the other selenate and chromate. Thus the mechanism by which ovulation is induced by chromate and selenate may be different from that of vanadium-containing compounds, molybdate, and tungstate.(ABSTRACT TRUNCATED AT 250 WORDS)



1956 ◽  
Vol 60 (12) ◽  
pp. 1662-1663 ◽  
Author(s):  
William F. Linke ◽  
Jerome A. Copper


1942 ◽  
Vol 64 (12) ◽  
pp. 2746-2748 ◽  
Author(s):  
J. E. Ricci ◽  
C. Weltman


2019 ◽  
Vol 21 (2) ◽  
pp. 155-171 ◽  
Author(s):  
Dmytro V. Gospodaryov ◽  
Olha M. Strilbytska ◽  
Uliana V. Semaniuk ◽  
Natalia V. Perkhulyn ◽  
Bohdana M. Rovenko ◽  
...  

AbstractMitochondrial alternative NADH dehydrogenase (aNDH) was found to extend lifespan when expressed in the fruit fly. We have found that fruit flies expressing aNDH from Ciona intestinalis (NDX) had 17–71% lifespan prolongation on media with different protein-tocarbohydrate ratios except NDX-expressing males that had 19% shorter lifespan than controls on a high protein diet. NDX-expressing flies were more resistant to organic xenobiotics, 2,4-dichlorophenoxyacetic acid and alloxan, and inorganic toxicant potassium iodate, and partially to sodium molybdate treatments. On the other hand, NDX-expressing flies were more sensitive to catechol and sodium chromate. Enzymatic analysis showed that NDX-expressing males had higher glucose 6-phosphate dehydrogenase activity, whilst both sexes showed increased glutathione S-transferase activity.





1955 ◽  
Vol 59 (3) ◽  
pp. 257-260 ◽  
Author(s):  
William E. Cadbury


Catalysts ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1239
Author(s):  
Manuel Ramos ◽  
Félix Galindo-Hernández ◽  
Brenda Torres ◽  
José Manuel Domínguez-Esquivel ◽  
Martin Heilmaier

We report the thermal stability of spherically shaped cobalt-promoted molybdenum disulfide (Co/MoS2) nano-catalysts from in-situ heating under electron irradiation in the scanning transmission electron microscope (STEM) from room temperature to 550 °C ± 50 °C with aid of Fusion® holder (Protochip©, Inc.). The catalytic nanoparticles were synthesized via a hydrothermal method using sodium molybdate (Na2MoO4·2H2O) with thioacetamide (CH3CSNH2) and cobalt chloride (CoCl2) as promoter agent. The results indicate that the layered molybdenum disulfide structure with interplanar distance of ~0.62 nm remains stable even at temperatures of 550 °C, as observed in STEM mode. Subsequently, the samples were subjected to catalytic tests in a Robinson Mahoney Reactor using 30 g of Heavy Crude Oil (AGT-72) from the golden lane (Mexico’s east coast) at 50 atm using (ultrahigh purity) UHP hydrogen under 1000 rpm stirring at 350 °C for 8 h. It was found that there is no damage on the laminar stacking of Co/MoS2 with temperature, with interlayer spacing remaining at 0.62 nm; these sulfided catalytic materials led to aromatics rise of 22.65% and diminution of asphaltenes and resins by 15.87 and 3.53%, respectively.



2012 ◽  
Vol 9 (4) ◽  
pp. 1746-1752 ◽  
Author(s):  
J. Wilson Sahayaraj ◽  
A. John Amalraj ◽  
Susai Rajendran ◽  
N. Vijaya

The inhibition efficiency (IE) of sodium molybdate (SM) in controlling corrosion of carbon steel in an aqueous solution containing 120 ppm of Cl-, in the absence and presence of Zn2+has been evaluated by weight-loss method. A synergistic effect exists between SM and Zn2+when the concentration of Zn2+is 25 ppm and above. Inhibition efficiencies obtained are greater than 85%. Antagonistic effect exists between SM and Zn2+when the concentration of Zn2+is 10 ppm and below. The SM-Zn2+system shows excellent IE up to third day. Above third day IE decreases. Acceleration of corrosion takes place. Excellent IE is shown at pH 5,7 and 12. At pH 9, IE decreases since Zn2+is precipitated as Zn(OH)2in the bulk of the solution. Polarization study reveals that SM-Zn2+system functions as a mixed inhibitor. FTIR spectra reveal that the protective film consists of Fe2+-SM complex and Zn(OH)2.



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