Log in

Relevant bibliographies by topics / Potassium oxide / Journal articles

To see the other types of publications on this topic, follow the link: Potassium oxide.

Journal articles on the topic 'Potassium oxide'

Author: Grafiati

Published: 4 June 2021

Last updated: 18 February 2022

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the top 50 journal articles for your research on the topic 'Potassium oxide.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.

1

Novosyolov, A., I. Olianina, I. Novoselova, Y. Vasina, Y. Ershova, T. Loik, and Yu Kudelina. "RESEARCH OF THE POSSIBILITY OF REDUCING THE CIRCULATION OF SULFUR OXIDE IN THE PRODUCTION OF WHITE CEMENT." Bulletin of Belgorod State Technological University named after. V. G. Shukhov 6, no. 7 (July 10, 2021): 89–98. http://dx.doi.org/10.34031/2071-7318-2021-6-7-89-98.

Full text

Abstract:

The article discusses the possibility of reducing the circulation of sulfur oxide in the production of white cement by introducing alkaline potassium oxides K2O and sodium Na2O. A decrease in the circulation of sulfur oxide SO3 is achieved by increasing its yield in the clinker by transferring SO3 from a more sublimated compound of calcium sulfate CaSO4 to less sublimated potassium sulfates K2SO4 and sodium Na2SO4. Potassium and sodium oxides are introduced in the composition of carbonates and feldspar. The amount of introduced alkali oxides is controlled by the molar ratio A/S between sulfur oxide SO3 and alkaline oxides K2O and Na2O. It is shown that with the same molar ratio between sulfur oxide and alkaline oxides, the amount of SO3 removed with clinker depends on the ratio between potassium and sodium oxides. The higher the sodium oxide content, the more sulfur oxide comes out with the clinker and less remains to circulate in the kiln. The sublimation of sulfur oxide decreases from 70.5% - without the introduction of alkaline oxides, to 38,5 % at the maximum A/S ratio with the addition of potassium and sodium oxides in a ratio of 80:20 %. When potassium and sodium oxides are added in a ratio of 20:80%, the sublimation of sulfur oxide is reduced to 7,7 % at the same A/S ratio.

APA, Harvard, Vancouver, ISO, and other styles

2

Derrien, Gaelle, Monique Tillard, Laure Monconduit, and Claude Belin. "Potassium barium bismuth oxide." Acta Crystallographica Section C Crystal Structure Communications 56, no. 6 (June 1, 2000): e232-e232. http://dx.doi.org/10.1107/s0108270100006855.

Full text

APA, Harvard, Vancouver, ISO, and other styles

3

Nguyen, Tu N., Daniel M. Giaquinta, William M. Davis, and Hans Conrad zur Loye. "Electrosynthesis of KBiO3 (potassium bismuth oxide): a potassium ion conductor with the KSbO3 (potassium antimony oxide) tunnel structure." Chemistry of Materials 5, no. 9 (September 1993): 1273–76. http://dx.doi.org/10.1021/cm00033a015.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

Drobasheva, T. I., S. B. Rastoropov, and A. N. Shabanova. "Potassium-cesium molybdenum oxide bronzes." Bulletin of the Russian Academy of Sciences: Physics 76, no. 7 (July 2012): 810–13. http://dx.doi.org/10.3103/s106287381207012x.

Full text

APA, Harvard, Vancouver, ISO, and other styles

5

JIANG, ZHI, HAIRONG ZHANG, ZHONGPENG WANG, MINGXIA CHEN, and WENFENG SHANGGUAN. "SIMULTANEOUSLY CATALYTIC REMOVAL OF NOx AND SOOT ON RARE EARTH ELEMENT OXIDE LOADED WITH POTASSIUM AND TRANSITION NANOSIZED METAL OXIDES." Nano 03, no. 04 (August 2008): 239–44. http://dx.doi.org/10.1142/s1793292008001088.

Full text

Abstract:

The simultaneous catalytic removal of NO x and soot over the rare earth element (REE) oxide-based mixture oxides loaded with potassium and transition nanosized metal oxide (designated as M/K/REE oxide) was investigated by using temperature-programmed reaction (TPR). The influence of the type of REE oxides together with the type and amount of transitional metal oxides on the catalytic removal activity was discussed. K / Nd 2 O 3 was found to be the most active oxide among the REE oxides to simultaneous remove the NO x and soot under lean conditions. Chromium oxide was more active than the other transition metal oxides on enhancing the activity of soot oxidation of Nd 2 O 3 loaded with potassium. The optimum loading level of chromium was about 10 wt%, with ignition temperature at about 237°C and the conversion ratio NO → N 2 about 24.1%. The Mn -loading on K / Nd 2 O 3 resulted in the biggest conversion efficiency of NO to N 2 at about 30.2%. The increasing catalytic reaction of NO x–soot activities is attributed to the formation of complex crystalline phase in the catalyst together with the improving contacting between catalysts and soot.

APA, Harvard, Vancouver, ISO, and other styles

6

Lendzion-Bieluń, Zofia, Rafał Pelka, and Łukasz Czekajło. "Characterization of FeCo based catalyst for ammonia decomposition. The effect of potassium oxide." Polish Journal of Chemical Technology 16, no. 4 (December 1, 2014): 111–16. http://dx.doi.org/10.2478/pjct-2014-0080.

Full text

Abstract:

Abstract FeCo fused catalyst was obtained by fusing iron and cobalt oxides with an addition of calcium, aluminium, and potassium oxides (CaO, Al2O3, K2O). An additional amount of potassium oxide was inserted by wet impregnation. Chemical composition of the prepared catalysts was determined with an aid of the XRF method. On the basis of XRD analysis it was found that cobalt was built into the structure of magnetite and solid solution of CoFe2O4 was formed. An increase in potassium content develops surface area of the reduced form of the catalyst, number of adsorption sites for hydrogen, and the ammonia decomposition rate. The nitriding process of the catalyst slows down the ammonia decomposition.

APA, Harvard, Vancouver, ISO, and other styles

7

Kim, Haegyeom, Dong-Hwa Seo, Alexander Urban, Jinhyuk Lee, Deok-Hwang Kwon, Shou-Hang Bo, Tan Shi, Joseph K. Papp, Bryan D. McCloskey, and Gerbrand Ceder. "Stoichiometric Layered Potassium Transition Metal Oxide for Rechargeable Potassium Batteries." Chemistry of Materials 30, no. 18 (August 29, 2018): 6532–39. http://dx.doi.org/10.1021/acs.chemmater.8b03228.

Full text

APA, Harvard, Vancouver, ISO, and other styles

8

Baumert, B. A. "Barium potassium bismuth oxide: A review." Journal of Superconductivity 8, no. 1 (February 1995): 175–81. http://dx.doi.org/10.1007/bf00732261.

Full text

APA, Harvard, Vancouver, ISO, and other styles

9

Cho, Min Kyoung, Jae Hyeon Jo, Ji Ung Choi, and Seung-Taek Myung. "Cycling Stability of Layered Potassium Manganese Oxide in Nonaqueous Potassium Cells." ACS Applied Materials & Interfaces 11, no. 31 (July 16, 2019): 27770–79. http://dx.doi.org/10.1021/acsami.9b06915.

Full text

APA, Harvard, Vancouver, ISO, and other styles

10

Ding, Keqiang. "Hydrothermal Synthesis of Leaf-Shaped Ferric Oxide Particles." E-Journal of Chemistry 6, s1 (2009): S280—S286. http://dx.doi.org/10.1155/2009/389765.

Full text

Abstract:

For the first time, leaf-shaped ferric oxide particles were prepared from an aqueous solution of potassium ferricyanide [K3Fe(CN)6] by hydrothermal process. Images obtained from SEM (scanning electron microscope) revealed that leaf-shaped ferric oxides (around 1.5 μm in length) were clearly exhibited when the hydrothermal tempreature was 150°C, while as the temperature was increased to 200°C leaf-shaped ferric oxide particles with larger size were observed. XRD (X-ray diffraction) patterns testified that the obtained ferric oxides were α-Fe2O3with well-structured crystal faces. Interestingly, histograms describing the distribution of samples indicated that the distribution of obtained ferric oxide particles did not accord with gaussian distribution

APA, Harvard, Vancouver, ISO, and other styles

11

Bento, Jennifer L., Drona R. Madugula, Chetan C. Hire, and Douglas H. Adamson. "Azeotrope enabled polymerization of ethylene oxide." RSC Advances 6, no. 97 (2016): 94459–66. http://dx.doi.org/10.1039/c6ra22064a.

Full text

Abstract:

We report a synthetic route for poly(ethylene oxide) (PEO) using azeotropic distillation to remove water and drive the equilibrium of an alkyl hydroxide and potassium hydroxide to potassium alkoxide, avoiding the use of pyrophoric organometallics.

APA, Harvard, Vancouver, ISO, and other styles

12

Jedrzejewski, Roman, Zofia Lendzion-Bieluń, and Walerian Arabczyk. "The activity of fused-iron catalyst doped with lithium oxide for ammonia synthesis." Polish Journal of Chemical Technology 18, no. 2 (June 1, 2016): 78–83. http://dx.doi.org/10.1515/pjct-2016-0032.

Full text

Abstract:

Abstract The iron catalyst precursor promoted with Al2O3, CaO, and Li2O was obtained applying the fusing method. Lithium oxide forms two phases in this iron catalyst: a chemical compound with iron oxide (Li2Fe3O4) and a solid solution with magnetite. The catalyst promoted with lithium oxide was not fully reduced at 773 K, while the catalyst containing potassium was easily reducible at the same conditions. After reduction at 873 K the activity of the catalyst promoted with lithium oxide was 41% higher per surface than the activity of the catalyst promoted with potassium oxide. The concentration of free active sites on the surface of the catalyst containing lithium oxide after full reduction was greater than the concentration of free active sites on the surface of the catalyst promoted with potassium oxide.

APA, Harvard, Vancouver, ISO, and other styles

13

Othman, M. R., Che Martunus, and W. J. N. Fernando. "Synthetic Hydrotalcite Prepared from Modified Combustion Method Using Glucose as Fuel." Advanced Materials Research 173 (December 2010): 146–49. http://dx.doi.org/10.4028/www.scientific.net/amr.173.146.

Full text

Abstract:

Hydrotalcite (HT) like compounds were successfully synthesized from combustion method using aluminum and magnesium nitrates, and potassium carbonate as solid precursors. Glucose was used as solid fuel to facilitate the reaction into mixed oxide and later HT structure at different combustion temperature. The combusted product initially formed disordered mixed oxides, but later returned to its original, more ordered HT state after being in contact with carbonate solution as analyzed from XRD. SEM analysis showed that the sample's microstructure was more orderly packed, less granular and more refined than its mixed oxide counterpart. The EDX analysis showed that the elemental potassium was the strongest energy binding in the hydrotalcite network followed by Al, Mg, O and C.

APA, Harvard, Vancouver, ISO, and other styles

14

Hirano, Takenori. "Roles of potassium in potassium-promoted iron oxide catalyst for dehydrogenation of ethylbenzene." Applied Catalysis 26 (January 1986): 65–79. http://dx.doi.org/10.1016/s0166-9834(00)82542-7.

Full text

APA, Harvard, Vancouver, ISO, and other styles

15

Ok, Seong-Ho, Jeong Yeol Han, Hui-Jin Sung, Seong Min Yang, Jungchul Park, Seong-Chun Kwon, Mun-Jeoung Choi, and Ju-Tae Sohn. "Ropivacaine-Induced Contraction Is Attenuated by Both Endothelial Nitric Oxide and Voltage-Dependent Potassium Channels in Isolated Rat Aortae." BioMed Research International 2013 (2013): 1–10. http://dx.doi.org/10.1155/2013/565271.

Full text

Abstract:

This study investigated endothelium-derived vasodilators and potassium channels involved in the modulation of ropivacaine-induced contraction. In endothelium-intact rat aortae, ropivacaine concentration-response curves were generated in the presence or absence of the following inhibitors: the nonspecific nitric oxide synthase (NOS) inhibitorNω-nitro-L-arginine methyl ester (L-NAME), the neuronal NOS inhibitorNω-propyl-L-arginine hydrochloride, the inducible NOS inhibitor 1400W dihydrochloride, the nitric oxide-sensitive guanylyl cyclase (GC) inhibitor ODQ, the NOS and GC inhibitor methylene blue, the phosphoinositide-3 kinase inhibitor wortmannin, the cytochrome p450 epoxygenase inhibitor fluconazole, the voltage-dependent potassium channel inhibitor 4-aminopyridine (4-AP), the calcium-activated potassium channel inhibitor tetraethylammonium (TEA), the inward-rectifying potassium channel inhibitor barium chloride, and the ATP-sensitive potassium channel inhibitor glibenclamide. The effect of ropivacaine on endothelial nitric oxide synthase (eNOS) phosphorylation in human umbilical vein endothelial cells was examined by western blotting. Ropivacaine-induced contraction was weaker in endothelium-intact aortae than in endothelium-denuded aortae.L-NAME, ODQ, and methylene blue enhanced ropivacaine-induced contraction, whereas wortmannin,Nω-propyl-L-arginine hydrochloride, 1400W dihydrochloride, and fluconazole had no effect. 4-AP and TEA enhanced ropivacaine-induced contraction; however, barium chloride and glibenclamide had no effect. eNOS phosphorylation was induced by ropivacaine. These results suggest that ropivacaine-induced contraction is attenuated primarily by both endothelial nitric oxide and voltage-dependent potassium channels.

APA, Harvard, Vancouver, ISO, and other styles

16

Frazier, A. W., K. R. Waerstad, Y. K. Kim, and B. G. Crim. "Phase system ferric oxide-potassium oxide-phosphorus pentoxide-water at 25.degree.C." Industrial & Engineering Chemistry Research 28, no. 2 (February 1989): 225–30. http://dx.doi.org/10.1021/ie00086a016.

Full text

APA, Harvard, Vancouver, ISO, and other styles

17

Yang, Song-Ling, Cheng-Che Tsai, Yi-Cheng Liou, Cheng-Shong Hong, Han-Chang Chen, and Sheng-Yuan Chu. "Differences Between Copper-Oxide- and Zinc-Oxide-Doped Sodium Potassium Niobate Ceramics." Journal of the American Ceramic Society 95, no. 7 (May 15, 2012): 2110–12. http://dx.doi.org/10.1111/j.1551-2916.2012.05246.x.

Full text

APA, Harvard, Vancouver, ISO, and other styles

18

Hirano, Takenori. "Dehydrogenation of Ethylbenzene on Potassium-Promoted Iron Oxide Catalyst Containing Magnesium Oxide." Bulletin of the Chemical Society of Japan 59, no. 8 (August 1986): 2672–74. http://dx.doi.org/10.1246/bcsj.59.2672.

Full text

APA, Harvard, Vancouver, ISO, and other styles

19

Perry, Dale L., Paul Berdahl, and Charles Perrino. "Magnetic characterization of calcium-nickel-potassium oxide catalysts." Journal of Materials Research 9, no. 11 (November 1994): 2993–97. http://dx.doi.org/10.1557/jmr.1994.2993.

Full text

Abstract:

SQUID magnetometer characterization of Ca–Ni–K–O catalyst materials reveals complex magnetic behavior. The magnetic properties are generally determined by the antiferromagnetic material NiO, but samples with traces of elemental nickel show marked effects of ferromagnetism. Potassium doping enhances the formation of metallic nickel. Further deviations from bulk NiO properties can be attributed to NiO particle size effects (superparamagnetism) and to the presence of paramagnetic impurities, possibly Ni3+ ions.

APA, Harvard, Vancouver, ISO, and other styles

20

Ravikant, Sheshamani Singh, Gaurav Gupta, Sanjay Yadav, P. K. Dubey, V. N. Ojha, and Ashok Kumar. "Highly-sensitive potassium-tantalum-niobium oxide humidity sensor." Sensors and Actuators A: Physical 295 (August 2019): 133–40. http://dx.doi.org/10.1016/j.sna.2019.05.023.

Full text

APA, Harvard, Vancouver, ISO, and other styles

21

Eisenmann, B., and U. Rössler. "Crystal structure of potassium tetrabarium tribismutide oxide, KBa4Bi3O." Zeitschrift für Kristallographie - New Crystal Structures 215, no. 3 (March 1, 2000): 349–50. http://dx.doi.org/10.1515/ncrs-2000-0321.

Full text

APA, Harvard, Vancouver, ISO, and other styles

22

Kim, Y. W., T. Masui, A. Oda, S. Tamura, and N. Imanaka. "Solution of potassium nitrate into gadolinium oxide lattice." physica status solidi (a) 198, no. 2 (August 2003): 369–73. http://dx.doi.org/10.1002/pssa.200306624.

Full text

APA, Harvard, Vancouver, ISO, and other styles

23

Zhao, L. Z., J. B. Zhang, D. B. Zhu, B. Yin, J. W. Li, C. Dong, and Z. X. Zhao. "Electrosynthesis of barium potassium lead oxide single crystals." Synthetic Metals 71, no. 1-3 (April 1995): 1615–16. http://dx.doi.org/10.1016/0379-6779(94)02976-6.

Full text

APA, Harvard, Vancouver, ISO, and other styles

24

Jang, Wooree, Dae-Young Jeon, Youn-Sik Lee, and Hye Young Koo. "Effect of Potassium Ions on the Formation of Mixed-Valence Manganese Oxide/Graphene Nanocomposites." Materials 12, no. 8 (April 16, 2019): 1245. http://dx.doi.org/10.3390/ma12081245.

Full text

Abstract:

One-pot synthesis of mixed-valence manganese oxide (MnOx)/potassium ion-doped reduced graphene oxide (rGO) composites for efficient electrochemical supercapacitors is introduced. Using manganese nitrate and potassium permanganate as co-precursors for the MnOx and by directly annealing the rGO without tedious purification steps, as described herein, MnOx/rGO composites with a high specific capacitance of 1955.6 F g−1 at a current density of 1 A g−1 are achieved. It is found that the presence of potassium ions helps in the development of mixed-valence MnOx on the surface of the rGO.

APA, Harvard, Vancouver, ISO, and other styles

25

Karásková, Kateřina, Kateřina Pacultová, Anna Klegova, Dagmar Fridrichová, Marta Valášková, Květuše Jirátová, Paweł Stelmachowski, Andrzej Kotarba, and Lucie Obalová. "Magnesium Effect in K/Co-Mg-Mn-Al Mixed Oxide Catalyst for Direct NO Decomposition." Catalysts 10, no. 8 (August 13, 2020): 931. http://dx.doi.org/10.3390/catal10080931.

Full text

Abstract:

Emission of nitric oxide represents a serious environmental problem since it contributes to the formation of acid rain and photochemical smog. Potassium-modified Co-Mn-Al mixed oxide is an effective catalyst for NO decomposition. However, there are problems related to the thermal instability of potassium species and a high content of toxic and expensive cobalt. The reported research aimed to determine whether these shortcomings can be overcome by replacing cobalt with magnesium. Therefore, a series of Co-Mg-Mn-Al mixed oxides with different Co/Mg molar ratio and promoted by various content of potassium was investigated. The catalysts were thoroughly characterized by atomic absorption spectroscopy (AAS), temperature-programmed reduction by hydrogen (TPR-H2), temperature-programmed desorption of CO2 (TPD-CO2), X-ray powder diffraction (XRD), N2 physisorption, species-resolved thermal alkali desorption (SR-TAD), and tested in direct NO decomposition with and without the addition of oxygen and water vapor. Partial substitution of magnesium for cobalt did not cause an activity decrease when the optimal molar ratio of K/Co on the normalized surface area was maintained; it means that the portion of expensive and toxic cobalt can be successfully replaced by magnesium without any decrease in catalytic activity.

APA, Harvard, Vancouver, ISO, and other styles

26

Black, DSC, and RJ Strauch. "Nitrones and Oxaziridines. XXXVII. Some Oxidation Reactions of 1-Pyrroline 1-Oxides." Australian Journal of Chemistry 41, no. 2 (1988): 183. http://dx.doi.org/10.1071/ch9880183.

Full text

Abstract:

The 2,4-diaryl-1-pyrroline 1-oxides (4) can be converted into the related 2H-pyrrole 1-oxides (5) by treatment with N-bromosuccinimide and anhydrous potassium carbonate. Similar treatment of the 1-pyrroline 1-oxide (6) yielded the succinimido-substituted pyrroline (7). Selenium dioxide oxidation of the tetramethyl nitrone (8) under various conditions gave mixtures containing the compounds (10)-(12). Neither process provides a general conversion of 1-pyrroline 1-oxides into 2H-pyrrole 1-oxides.

APA, Harvard, Vancouver, ISO, and other styles

27

HAMILTON, C. A., G. BERG, K. MCARTHUR, J. L. REID, and A. F. DOMINICZAK. "Does potassium channel opening contribute to endothelium-dependent relaxation in human internal thoracic artery?" Clinical Science 96, no. 6 (May 11, 1999): 631–38. http://dx.doi.org/10.1042/cs0960631.

Full text

Abstract:

Opening of potassium channels can cause hyperpolarization and relaxation of vascular smooth muscle cells. The aim of this work was to investigate the contribution of potassium channel activation to vasorelaxation in internal thoracic artery taken from patients undergoing coronary artery bypass graft surgery. Relaxations to carbachol and sodium nitroprusside were studied in isolated rings of internal thoracic artery in the absence and presence of nitric oxide synthase inhibitors and potassium channel blockers. The nitric oxide synthase inhibitors Nω-nitro-⌊-arginine methyl ester and NG-monomethyl-⌊-arginine abolished relaxations to carbachol. Relaxations to both carbachol and sodium nitroprusside were attenuated in the presence of raised extracellular potassium and the potassium channel blockers charybdotoxin, iberiotoxin and tetraethylammonium. Neither apamin nor glibenclamide modified relaxation. ODQ (1H-[1,2,4]oxadiazolol-[4,3a] quinoxalin-1-one), an inhibitor of soluble guanylate cyclase, abolished relaxation to carbachol in rings from some but not all subjects. These results suggest that potassium channel opening may make a small contribution to endothelium-dependent vasorelaxation in internal thoracic artery. The potassium channels had characteristics consistent with those of large-conductance calcium-dependent potassium channels.

APA, Harvard, Vancouver, ISO, and other styles

28

Inaba, Katsuya, Ichiro Fujii, Kouichi Nakashima, Hiroshi Hayashi, Yuichi Yamamoto, Yoshihiro Kuroiwa, and Satoshi Wada. "Preparation of Grain-Oriented Ceramics with Bismuth Potassium Titanate-Barium Titanate and their Piezoelectric Properties." Key Engineering Materials 582 (September 2013): 80–83. http://dx.doi.org/10.4028/www.scientific.net/kem.582.80.

Full text

Abstract:

Bismuth potassium titanate ((Bi1/2K1/2)TiO3: BKT) powder were prepared using bismuth oxide (Bi2O3), potassium hydrogen carbonate (KHCO3) and titanium oxide (TiO2) raw materials. Barium titanate (BaTiO3: BT) platelike particles oriented along [110] direction were used as template particles. Barium titanate-bismuth potassium titanate (BT-BKT) ceramics had a tetragonal phase at -100 °C. The main composition was fixed to BKT 30 molar% because the Curie temperature (TC) was well above 200 °C at BKT 30 molar%. The orientation of [110]-oriented BT-BKT ceramics (BKT 30 molar%) was 54.6 %.

APA, Harvard, Vancouver, ISO, and other styles

29

Mehmood, Tariq, Syed Waseem Haider, and Saima Siddiqui. "Major, Minor and Trace Elements Existence in Surface Sediments from Gwadar to Jiwani Coastal Areas of Pakistan." International Journal of Economic and Environmental Geology 11, no. 2 (September 25, 2020): 37–45. http://dx.doi.org/10.46660/ijeeg.vol11.iss2.2020.444.

Full text

Abstract:

This study was carried out along the western coastal parts of Balochistan from Gwadar east Bay to Jiwani. The local anomaly of major, minor and trace elements were studied in this area. Zone-I (Gwadar east and west Bay) indicates that calcium oxide, potassium oxide and titanium dioxide have higher or average concentrations, while ZoneII indicates higher or average concentrations of calcium oxide, titanium dioxide and ferric oxide. Trace elements zirconium, chromium, europium, strontium, and copper are in higher or average concentrations in both zones. Gwadar west Bay and Jiwani are intermediate in carbonate, which show a high degree of maturity, suggesting the high rate of weathering in the source area. Sediment samples from Ganz, Jiwani, and Gwadar east Bay represent the quartz-rich fields in this region. Gwadar east Bay has a positive correlation between aluminium oxide and potassium oxide which suggests that abundance of potassium oxide is controlled by variation in K-feldspar contents. A positive correlation between strontium and calcium oxide suggests that strontium is associated with calcium oxide in biogenic carbonate material in Gwadar west Bay. The positive correlation between aluminium oxide, copper, and zinc in Pishukan indicates that the abundance of these elements is due to limited silt and clay fractions present in sediments. Enrichment factor shows that chromium and strontium are probably of anthropogenic origin in this region. Keywords

APA, Harvard, Vancouver, ISO, and other styles

30

Chen, Jun Hong, Bin Li, Hua Sheng Zhan, Jin Dong Su, Ming Wei Yan, and Xiao Ping Li. "Action Mechanism of β-Si3N4 in Bauxite Sintering." Applied Mechanics and Materials 543-547 (March 2014): 3834–38. http://dx.doi.org/10.4028/www.scientific.net/amm.543-547.3834.

Full text

Abstract:

In this paper, we added silicon nitride in the samples of common bauxite and the bauxite with high potassium and sodium oxide content, treated them at the high temperature of 1,400°Cand 1,500°C, and then conducted analysis with XRD, SEM and EDS. The results are as follows: After adding β-Si3N4 in sintered bauxite, the partial pressure of oxygen in the composite materials will be reduced, the decomposition and volatilization of compounds with high partial pressure of oxygen (such as potassium oxide and sodium oxide) will be promoted, the content of these compounds in the bauxite will be lowered, and the hazards of the compounds with low melting point will be weakened; meanwhile, with the reduction of potassium, sodium and iron oxide, the lattice of alumina will be activated, the β-Sialon phase will be easily formed and the high temperature properties of sintered bauxite materials will be strengthened.

APA, Harvard, Vancouver, ISO, and other styles

31

Šilhánková, Alexandra, Jana Hulvová, Petr Trška, and Miloslav Ferles. "Condensation reactions of 2,4- and 2,6-dimethylpyridines and their 1-oxides." Collection of Czechoslovak Chemical Communications 54, no. 6 (1989): 1687–704. http://dx.doi.org/10.1135/cccc19891687.

Full text

Abstract:

Using the reactions of 2,4- and 2,6-dimethylpyridine-1-oxides with aromatic and heteroaromatic aldehydes under catalysis with potassium tert-butoxide (E)-aryl- and (E)-heteroarylethenylpyridine-1-oxides IIIa-IIIe, IVa-IVc, Va, Vb respectively, were prepared. 1-Oxides IIIg, IVd, IVe and Vc were obtained from the appropriate pyridine bases by oxidation with peracetic acid. Condensation of 2,4- and 2,6-dimethylpyridines with 3-pyridinecarbaldehyde gives a mixture of bases VIa and VIc, and VIb and VId, respectively. On Claisen condensation of 2,6- or 2,4-dimethylpyridine-1-oxide with diethyl oxalate in the presence of sodium hydride and potassium tert-butoxide lactone XIIa and XIIb is formed in addition to α-keto ester XIa and XIb, respectively. From esters XIa and XIb amides XId and XIe were prepared.

APA, Harvard, Vancouver, ISO, and other styles

32

Lehmusto, Juho, Patrik Yrjas, Bengt Johan Skrifvars, and Mikko Hupa. "Detailed Studies on the High Temperature Corrosion Reactions between Potassium Chloride and Metallic Chromium." Materials Science Forum 696 (September 2011): 218–23. http://dx.doi.org/10.4028/www.scientific.net/msf.696.218.

Full text

Abstract:

Recovery of energy from biomass and various waste–derived fuels by combustion has become important due to reduction of detrimental CO2 emissions. Biomass does, however, release significant amounts of chlorine and alkali metals, as e.g. HCl(g), KCl(g), KOH(g) and NaCl(g), into the gas phase during combustion. The alkali chlorides may cause deposits on superheater tubes, which interfere with operation and can lead to corrosion and/or blockage of the gas path. To prevent and diminish the problems mentioned above, better and more detailed knowledge of the reactions between potassium chloride and the tube materials during combustion is needed. These materials commonly contain, among other metals, chromium, which is thought to protect the rest of the material since it forms a very dense but thin oxide layer on the surface of the tube material. It has been suggested that the reaction between solid or partly molten KCl and chromium oxide is the one responsible for starting the complex series of corrosion reactions. In this work, the overall reaction between potassium chloride and chromium was studied through partial reactions with compounds known to participate to the overall reaction or to be formed during it. The reactions were studied in synthetic air by heating sample mixtures in a DTA/TGA (Differential Thermal Analysis/ Thermogravimetric Analysis) apparatus. Selected samples were also studied and analyzed with a scanning electron microscope equipped with an energy dispersive x-ray analyzer (SEM/EDXA). Under the used conditions both potassium chloride and potassium chromate reacted with pure chromium and chromium oxide. In the case of chromium, chromium oxide was formed via the formation of potassium chromate. In reactions including chromium oxide as reactant also potassium dichromate was detected.

APA, Harvard, Vancouver, ISO, and other styles

33

Tian, Zhaohui, Lijun Song, and Xinmin Li. "Effect of Oxidizing Decontamination Process on Corrosion Property of 304L Stainless Steel." International Journal of Corrosion 2019 (August 1, 2019): 1–6. http://dx.doi.org/10.1155/2019/1206098.

Full text

Abstract:

Corrosion behaviors of 304L stainless steel (SS) and 304L SS with oxides film (preoxidation 304L SS) in 1 g/L potassium permanganate solution of various pH values were investigated by using mass loss, electrochemical measurement and scanning electron microscope (SEM) observation. The results showed that mass loss of 304L SS increases with the increase of sodium hydroxide or nitric acid concentration in 1 g/L potassium permanganate solution. The polarization curves of 304L SS in potassium permanganate solution show that passive zones are destroyed more easily in acid potassium permanganate solution than alkaline potassium permanganate solution. The corrosion ability of acid potassium permanganate (NP) decontamination solution used for 304L SS is more aggressive than alkaline potassium permanganate (AP) solution. The oxide film on the surface of preoxidation 304L SS can be removed completely in two oxidation reduction decontamination cycles, oxidizing solution of which comprised 0.4g/L sodium hydroxide and 1g/L potassium permanganate. The 304L SS and preoxidation 304L SS performed alkaline oxidation reduction decontamination of 3 cycles were reoxidation. The micromorphology of reoxidation specimens was similar to preoxidation 304L SS. Therefore the chemical decontamination of alkaline oxidizing and acid reducing steps had no negative effect on corrosion of 304L SS and reoxidation of 304L SS carried out decontamination.

APA, Harvard, Vancouver, ISO, and other styles

34

Wu, Lei, Kai Luo, Ling Zhang, Kai Wei, and Wen-Chao Yang. "Latent Radical Cleavage of α-Allenylic C–O Bonds: Potassium Persulfate Mediated Thiolation of Allenylphosphine Oxides." Synthesis 50, no. 15 (April 19, 2018): 2990–98. http://dx.doi.org/10.1055/s-0037-1609835.

Full text

Abstract:

A novel potassium persulfate (K2S2O8) mediated thiolation of allenylphosphine oxides with diaryl sulfides is disclosed. Mechanistic studies indicate that K2S2O8 homolyzes the diaryl sulfide to produce a thiyl radical (PhS•), which is followed by C–O bond cleavage of the allenylphosphine oxide under metal-free conditions, affording novel S,P-bifunctionalized butadienes in moderate to excellent yields.

APA, Harvard, Vancouver, ISO, and other styles

35

Gu, Xing Yong, Wen Qin Luo, and Yun Xia Chen. "Study on Co-KZr₂(PO₄)₃-Type Crystalline Purple Ceramic Pigments." Applied Mechanics and Materials 34-35 (October 2010): 790–94. http://dx.doi.org/10.4028/www.scientific.net/amm.34-35.790.

Full text

Abstract:

Using potassium carbonate, ammonium phosphate, zirconium dioxide, and cobalt oxide as raw materials, a kind of potassium zirconium phosphate ceramic pigments with bright purple color at high temperature were obtained through a series of optimizing experiments. It’s a novel type of ceramic pigments with chromaticity indexes of L*=55.37, a*=18.52, and b*=-30.56. X-ray diffraction (XRD), TG-DTA and chroma analysis were employed to characterize the pigments. The results reveal that potassium zirconium phosphate type ceramic pigments presenting bright purple color is due to Co2+ partially replace Zr4+ in potassium zirconium phosphate crystal lattice, which leads to the lattice distortion because of the formation of Zr2-xCo2x(PO4)3 phase. Moreover, owing to the limitation of solubility of Co2+ in potassium zirconium phosphate crystal lattice, the contents of cobalt oxide added may not be too much.

APA, Harvard, Vancouver, ISO, and other styles

36

Mulinta, Soravich. "The Experimental of Low Temperature Color Slip for Decorative on Earthenware Body." Key Engineering Materials 690 (May 2016): 282–85. http://dx.doi.org/10.4028/www.scientific.net/kem.690.282.

Full text

Abstract:

The purpose of the study was to investigate the effects of dolomite body, frit and potassium feldspar on the properties of color slip for decorative method of color slip on earthen ware production. The characterization of raw material was analyzed by X-ray fluorescence (XRF). The experiment started with triaxial blend of dolomite body, frit and potassium feldspar in the defined ratio and then to painting of color slips on earthenware production. After that, firing specimens at 950 °C in oxidation atmosphere. Finally, the specimens were tested microstructure and physical properties. The results showed that the ratio of 50% dolomite body, 40% frit and 10% potassium feldspar were optimum properties for decorative on earthenware body. In color slip consisting of blue color added Cobalt oxide 1% ,Green colors added chromic oxide 10% , Gray color added manganese oxide 10% ,yellow color added stain 2225 10% and hazel color added ferric oxide 2 wt %.

APA, Harvard, Vancouver, ISO, and other styles

37

Hirano, Takenori. "Dehydrogenation of ethylbenzene over potassium-promoted iron oxide containing cerium and molybdenum oxides." Applied Catalysis 28 (December 1986): 119–32. http://dx.doi.org/10.1016/s0166-9834(00)82497-5.

Full text

APA, Harvard, Vancouver, ISO, and other styles

38

Jirátová, Květa, Kateřina Pacultová, Kateřina Karásková, Jana Balabánová, Martin Koštejn, and Lucie Obalová. "Direct Decomposition of NO over Co-Mn-Al Mixed Oxides: Effect of Ce and/or K Promoters." Catalysts 10, no. 7 (July 20, 2020): 808. http://dx.doi.org/10.3390/catal10070808.

Full text

Abstract:

Co-Mn-Al mixed oxides promoted by potassium are known as active catalysts for the direct decomposition of nitric oxide (NO). In this study, the answer to the following question has been considered: does the presence of cerium in K-promoted Co-Mn-Al catalysts substantially affect the physical-chemical properties, activity, and stability in direct NO decomposition? The Co-Mn-Al, Co-Mn-Al-Ce, and Co-Mn-Al-Ce-K mixed oxide catalysts were prepared by the precipitation of corresponding metal nitrates with a solution of Na2CO3/NaOH, followed by the washing of the precipitate and calcination. Two other catalysts were prepared by impregnation of the Ce-containing catalysts with Co and Co+K nitrates. After calcination, the solids were characterized by chemical analysis, XRD, N2 physisorption, FTIR, temperature-programmed reduction, CO2 and O2 desorption (H2-TPR, CO2-TPD, O2-TPD), and X-ray photoelectron spectrometry (XPS). Cerium and especially potassium occurring in the catalysts affected the basicity, reducibility, and surface concentration of active components. Adding cerium itself did not contribute to the increase in catalytic activity, whereas the addition of cerium and potassium did. Catalytic activity in direct NO decomposition depended on combinations of both reducibility and the amount of stronger basic sites determined in the catalysts. Therefore, the increase in cobalt concentration itself in the Co-Mn-Al mixed oxide catalyst does not determine the achievement of high catalytic activity in direct NO decomposition.

APA, Harvard, Vancouver, ISO, and other styles

39

Syukri, Syukri, Fadhil Ferdian, Yetria Rilda, Yulia Eka Putri, Mai Efdi, and Upita Septiani. "Synthesis of Graphene Oxide Enriched Natural Kaolinite Clay and Its Application For Biodiesel Production." International Journal of Renewable Energy Development 10, no. 2 (December 14, 2020): 307–15. http://dx.doi.org/10.14710/ijred.2021.32915.

Full text

Abstract:

A heterogeneous catalyst is one type of catalyst which is very effective for biodiesel production; thus, in this study, a novel heterogeneous bifunctional catalyst was prepared by kaolinite clay obtained from Padang of West Sumatera and impregnated with graphene oxide and potassium hydroxide (KOH) for the simultaneous esterification and transesterification reactions of palm oil into biodiesel. For comparison, two other catalysts were also prepared. The first catalyst was the same clay which was heated at 450ºC for 4 hours, and the second catalyst was the same clay which was impregnated with potassium hydroxide (KOH) only. The three catalysts were characterized using X-Ray Fluorescence (XRF), X-Ray Diffraction (XRD), and Fourier Transform Infra-Red (FTIR). XRF analysis showed that the clay sample’s main composition consisted of 54% silica, 35% alumina, and 7% hematite. The XRD analysis results showed that the most dominant crystal composition was quartz, kaolinite, and hematite. The analysis results using FTIR showed a change in intensity and shift in wave numbers indicating a cation exchange. The catalytic activity test was carried out with a ratio of oil and methanol 1:6, catalyst amount 5%, 60ºC reaction temperature, and 4 hours of reaction time.The results showed that the catalytic activity of clays impregnated with graphene oxide and potassium hydroxide was better with a yield of 58% compared to clays without impregnation and other clays that were only impregnated with KOH under the yields of 0.8% and 0.4%, respectively

APA, Harvard, Vancouver, ISO, and other styles

40

Dvoretskii, Nikolai V., Lyubov G. Anikanova, and Zoya G. Malysheva. "TYPES OF ACTIVE CENTERS ON SURFACE OF PROMOTED IRON OXIDE CATALYST." IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENIY KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA 61, no. 6 (June 6, 2018): 61. http://dx.doi.org/10.6060/tcct.20186106.5658.

Full text

Abstract:

The phase and chemical composition of compounds in the potassium-iron-oxygen system in a wide range of molar ratios of potassium and iron was studied by X-ray phase analysis and atomic absorption spectroscopy. The catalytic properties and the mass fraction of coke deposits on ferritic systems of various composition are determined. It has been shown that at least two types of active sites are present on the surface of the iron oxide catalyst. The dehydrogenation centers include oxygen ion, ions of a promoting alkali metal, and ions of bivalent and triply charged iron, between which electron exchange takes place. Most probably such center is realized in the structure of potassium-polyferrite (K2Fe2+Fe3+10O17). The coke formation centers contain an unpromoted cluster consisting of oxygen ion and iron (III) ion, are realized in Fe3O4 and KFe11O17. Coke deposits on the surface of the catalyst block non-selective active sites and increase the selectivity of action. The probability of realization of clusters corresponding to the dehydrogenation centers is three orders of magnitude higher than in the places of phase contact, the aggregate of which contains the whole set of ions corresponding to dehydrogenation centers, for example, "magnetite + potassium monoferrite". The pure potassium β"-polyferrite provides an optimal concentration of selective centers on the surface of the catalyst, operates highly efficiently in the absence of negative external influences (catalyst re-recovery, corrosion reaction of the reaction medium, poisoning effect). Individual b²-polyferrites, like any catalytically active phase, are unstable, however, being in equilibrium with potassium monoferrate and magnetite, it is able to operate effectively for a long time and to withstand the negative effects of redox properties of the surrounding reaction medium. The presence of potassium monoferrite in the catalytically active system ensures the polyfunctionality of the action of contact, i.e. ability to self-regeneration. It is likely that in the structure of potassium monoferrite, centers for preventing coke formation and annealing of coke are realized, containing oxygen ion, iron ion, and alkaline promoter.Forcitation:Dvoretskii N.V., Anikanova L.G., Malysheva Z.G. Types of active centers on surface of promoted iron oxide catalyst. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 6. P. 61-68

APA, Harvard, Vancouver, ISO, and other styles

41

Chen, Qing, Jin Song Zhou, Qin Feng Mei, and Zhong Yang Luo. "The Release Behavior of Potassium and Sodium in the Biomass High-Temperature Entrained-Flow Gasification." Applied Mechanics and Materials 71-78 (July 2011): 2434–41. http://dx.doi.org/10.4028/www.scientific.net/amm.71-78.2434.

Full text

Abstract:

Experiments were performed to investigate the release behavior of potassium and sodium in the biomass high-temperature entrained-flow gasification with the addition of acid oxide SiO2, basic oxide MgO, amphoteric oxide Al2O3. The results showed that the volatilization of alkali was found to strongly depend on temperature. High gasification temperature strengthened the alkali release. When the reactor temperature was 1200°C, the volatilization of alkali species were about 37.87% for K and 71.14% for Na. Three additives all favored the retention of potassium and sodium and the content of water-soluble potassium and sodium in the ash. Among the three additives, MgO had the best retention effect. The potassium and sodium content in the gas phase was as low as 46.6% and 67.3% compared with raw straw, respectively. In the entrained-flow gasification with short residence time, the additives retained more alkali metals by the physical and chemical adsorption. Part of the additive utilized as physical adsorbent during the gasification enhanced the ash melting point of the residue carbon.

APA, Harvard, Vancouver, ISO, and other styles

42

Gorokhovskii, A. V., D. V. Meshcheryakov, I. N. Burmistrov, and A. V. Sevryugin. "Heat-reflecting ceramic materials based on potassium poly-titanate and silicon oxide." NOVYE OGNEUPORY (NEW REFRACTORIES), no. 12 (December 25, 2018): 54–57. http://dx.doi.org/10.17073/1683-4518-2018-12-54-57.

Full text

Abstract:

The possibility is studied to obtain the porous ceramic composite with the low heat conductivity and high heatreflecting ability on base of the raw mixture of potassium poly-titanate and different silicon oxide modifications. It was shown that the silicon oxide introduction favors the glass potassium-silicon phase formation which acts as a binding agent and promotes the ceramic composite structure creation, the composite consisting of interwoven high-strength fibrous K2Ti6O13 crystals, bound by means of evenly spread glass phase.

APA, Harvard, Vancouver, ISO, and other styles

43

Cowan, C. L., and R. A. Cohen. "Two mechanisms mediate relaxation by bradykinin of pig coronary artery: NO-dependent and -independent responses." American Journal of Physiology-Heart and Circulatory Physiology 261, no. 3 (September 1, 1991): H830—H835. http://dx.doi.org/10.1152/ajpheart.1991.261.3.h830.

Full text

Abstract:

The role of nitric oxide and guanosine 3',5'-cyclic monophosphate (cGMP) accumulation in the endothelium-dependent relaxation of the porcine coronary artery to bradykinin was investigated by comparing relaxation and cGMP accumulation in the presence or absence of NG-monomethyl-L-arginine (L-NMMA) and methylene blue. Rings were treated with indomethacin to eliminate the effects of prostaglandins. Relaxation to bradykinin of rings contracted with the thromboxane A2 mimetic U-46619 was not affected by L-NMMA and was only minimally inhibited by methylene blue. Rings contracted with elevated potassium (25 mM) also relaxed completely to bradykinin. However, L-NMMA or methylene blue effectively inhibited relaxation to bradykinin in rings contracted with potassium. cGMP accumulation was stimulated by bradykinin and inhibited by L-NMMA or methylene blue in rings contracted with either U-46619 or potassium. These results suggest that in the absence of nitric oxide-induced cGMP accumulation, a nonprostanoid mechanism exists that is capable of completely relaxing U-46619-contracted coronary artery. This mechanism is either inhibited in or unable to relax potassium-contracted rings. These results also demonstrate that nitric oxide mediates the bradykinin-induced cGMP accumulation that is largely responsible for the relaxation during contraction with potassium.

APA, Harvard, Vancouver, ISO, and other styles

44

He, Dongning, Zheng Peng, Wei Gong, Yongyue Luo, Pengfei Zhao, and Lingxue Kong. "Mechanism of a green graphene oxide reduction with reusable potassium carbonate." RSC Advances 5, no. 16 (2015): 11966–72. http://dx.doi.org/10.1039/c4ra14511a.

Full text

APA, Harvard, Vancouver, ISO, and other styles

45

Woon Kim, Young, Atsushi Oda, and Nobuhito Imanaka. "Extraordinary high potassium ion conducting polycrystalline solids based on gadolinium oxide–potassium nitrite solid solution." Electrochemistry Communications 5, no. 1 (January 2003): 94–97. http://dx.doi.org/10.1016/s1388-2481(02)00537-4.

Full text

APA, Harvard, Vancouver, ISO, and other styles

46

Liang, Huanyu, Yongcheng Zhang, Shujin Hao, Luhan Cao, Yanhong Li, Qiang Li, Dong Chen, Xia Wang, Xiangxin Guo, and Hongsen Li. "Fast potassium storage in porous CoV2O6 nanosphere@graphene oxide towards high-performance potassium-ion capacitors." Energy Storage Materials 40 (September 2021): 250–58. http://dx.doi.org/10.1016/j.ensm.2021.05.013.

Full text

APA, Harvard, Vancouver, ISO, and other styles

47

Min, Shi, Hideharu Ishihara, Toshiaki Murai, and Shinzi Kato. "A Convenient Preparation of Bis(phosphorothioyl) Sulfides." Zeitschrift für Naturforschung B 44, no. 2 (February 1, 1989): 153–57. http://dx.doi.org/10.1515/znb-1989-0211.

Full text

Abstract:

Abstract The reaction of piperidinium and potassium phosphorodithioates with 2-chloro-1-methyl-pyridinium salts afforded the corresponding bis(phosphorothioyl) sulfides in good yields. The similar reaction with potassium diphenylphosphorothioate gave exclusively bis(diphenylphos-phorothioyl) oxide.

APA, Harvard, Vancouver, ISO, and other styles

48

Liu, Ping, Ji-Guang Zhang, and John A. Turner. "Potassium manganese–vanadium oxide cathodes prepared by hydrothermal synthesis." Journal of Power Sources 92, no. 1-2 (January 2001): 204–11. http://dx.doi.org/10.1016/s0378-7753(00)00542-5.

Full text

APA, Harvard, Vancouver, ISO, and other styles

49

Ndlela, Sipho C., and Brent H. Shanks. "Reducibility of Potassium-Promoted Iron Oxide under Hydrogen Conditions." Industrial & Engineering Chemistry Research 42, no. 10 (May 2003): 2112–21. http://dx.doi.org/10.1021/ie020841+.

Full text

APA, Harvard, Vancouver, ISO, and other styles

50

Dickie, B. G. M., M. J. Lewis, and J. A. Davies. "Potassium-stimulated release of nitric oxide from cerebellar slices." British Journal of Pharmacology 101, no. 1 (September 1990): 8–9. http://dx.doi.org/10.1111/j.1476-5381.1990.tb12078.x.

Full text

APA, Harvard, Vancouver, ISO, and other styles

We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!