База данных: Статьи
Страница 3, Результатов: 28
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21.
Подробнее
24
M23
Mamyrbekova, А.
Study of kinetics of copper oxidation by electrolysis under non-stationary conditions. [Текст] / А. Mamyrbekova, А. Mamyrbekova, M. К. Kassymova, A. Zh. Aitbayeva, O. N. Chechina // News of national academy of sciences of the republic of Kazakhstan. . - 2021. - №3. - P. 54-59
ББК 24
Рубрики: chemistry
Кл.слова (ненормированные):
copper electro-oxidation -- copper (I) oxide -- copper (II) oxide -- unsteady electrolysis -- electrolyte -- polarisation curves
Аннотация: The nature of the anion electrolyte affects the rate of copper anodic oxidation, while the process occurs more efficiently in solutions of sulfate and sodium chloride and is accompanied by significant polarisation. Based on the study of kinetics the possibility of obtaining powders of metal oxide was shown, which further allowed to determine the parameters of the electrolysis process in non-stationary conditions in order to obtain highly dispersed materials based on copper oxides with specific physico-chemical properties.
Держатели документа:
WKU
Доп.точки доступа:
Mamyrbekova, А.
Kassymova, M.К.
Aitbayeva, A.Zh.
Chechina, O.N.
M23
Mamyrbekova, А.
Study of kinetics of copper oxidation by electrolysis under non-stationary conditions. [Текст] / А. Mamyrbekova, А. Mamyrbekova, M. К. Kassymova, A. Zh. Aitbayeva, O. N. Chechina // News of national academy of sciences of the republic of Kazakhstan. . - 2021. - №3. - P. 54-59
Рубрики: chemistry
Кл.слова (ненормированные):
copper electro-oxidation -- copper (I) oxide -- copper (II) oxide -- unsteady electrolysis -- electrolyte -- polarisation curves
Аннотация: The nature of the anion electrolyte affects the rate of copper anodic oxidation, while the process occurs more efficiently in solutions of sulfate and sodium chloride and is accompanied by significant polarisation. Based on the study of kinetics the possibility of obtaining powders of metal oxide was shown, which further allowed to determine the parameters of the electrolysis process in non-stationary conditions in order to obtain highly dispersed materials based on copper oxides with specific physico-chemical properties.
Держатели документа:
WKU
Доп.точки доступа:
Mamyrbekova, А.
Kassymova, M.К.
Aitbayeva, A.Zh.
Chechina, O.N.
22.
Подробнее
24
M97
Mussina, А. S.
Development of the conditions for strong thallium amalgam. [Текст] / А. S. Mussina // News of national academy of sciences of the republic of Kazakhstan. . - 2021. - №3. - P. 65-70
ББК 24
Рубрики: chemistry
Кл.слова (ненормированные):
thallium amalgam -- chemical preparation -- storage -- decomposition -- sulfuric acid -- water -- wash liquid
Аннотация: It has been established that lNH2SO4 solution and distilled water can be used as a protective medium for a long-term storage (30-40 days) of thallium amalgam of eutectic composition (8.6 mas.%), without sliming of its surface and an insignificant change of its concentration. An inverse dependence between the decomposition reaction rate and the ratio of the solution volume per unit of the contact surface (V:S), which corresponds to the height of the liquid layer (h) above the amalgam, is observed. At h ~ 2.5 cm and higher, the reaction rate becomes stabilized. The value of metal loss during its storage for 10-15 days does not exceed 0.5-1.0 mas.% of the initial thallium content in the amalgam. It has been shown that the rate of dissolution of thallium from amalgam is rather low, and in sulfuric acid solution it is only slightly higher than that in water with all S:V ratios. A similar picture is observed upon thallium amalgam decomposition in the same media in an open vessel; the difference consists only in a higher K value (Table 4). Thus, with S:V = 1:2.5, in an open vessel K in lNH2SO4 makes up 10,5.1011 mol/cm2.sec, and in H2O – 7.3.1011 mol/cm2.sec, whereas in a closed vessel K in lNH2SO4 makes up 1,9.1011 mol/cm2.sec, and in H2O – 1.5.1011 mol/cm2.sec. For 40 days of thallium amalgam (8.54 mas.%) storage in 1NH2SO4 the loss of thallium has been 1.3 mas.%, and in the distilled water - 1 mas.%. The quantity of the dissolved metal increases in proportion to the experiment duration, which is characteristic for a zero-order reaction, and this dependence is observed for all S:V ratios from 1:1 to 1:7. Besides, a possibility to use some saturated hydrocarbons, wherein no sliming of thallium amalgam occurs, as a protective wash liquid has been shown.
Держатели документа:
WKU
Доп.точки доступа:
Baitasheva, G.U.
Myrzakhmetova, N.О.
Tagabergenova, Zh.A.
Gorbulicheva , E.P.
M97
Mussina, А. S.
Development of the conditions for strong thallium amalgam. [Текст] / А. S. Mussina // News of national academy of sciences of the republic of Kazakhstan. . - 2021. - №3. - P. 65-70
Рубрики: chemistry
Кл.слова (ненормированные):
thallium amalgam -- chemical preparation -- storage -- decomposition -- sulfuric acid -- water -- wash liquid
Аннотация: It has been established that lNH2SO4 solution and distilled water can be used as a protective medium for a long-term storage (30-40 days) of thallium amalgam of eutectic composition (8.6 mas.%), without sliming of its surface and an insignificant change of its concentration. An inverse dependence between the decomposition reaction rate and the ratio of the solution volume per unit of the contact surface (V:S), which corresponds to the height of the liquid layer (h) above the amalgam, is observed. At h ~ 2.5 cm and higher, the reaction rate becomes stabilized. The value of metal loss during its storage for 10-15 days does not exceed 0.5-1.0 mas.% of the initial thallium content in the amalgam. It has been shown that the rate of dissolution of thallium from amalgam is rather low, and in sulfuric acid solution it is only slightly higher than that in water with all S:V ratios. A similar picture is observed upon thallium amalgam decomposition in the same media in an open vessel; the difference consists only in a higher K value (Table 4). Thus, with S:V = 1:2.5, in an open vessel K in lNH2SO4 makes up 10,5.1011 mol/cm2.sec, and in H2O – 7.3.1011 mol/cm2.sec, whereas in a closed vessel K in lNH2SO4 makes up 1,9.1011 mol/cm2.sec, and in H2O – 1.5.1011 mol/cm2.sec. For 40 days of thallium amalgam (8.54 mas.%) storage in 1NH2SO4 the loss of thallium has been 1.3 mas.%, and in the distilled water - 1 mas.%. The quantity of the dissolved metal increases in proportion to the experiment duration, which is characteristic for a zero-order reaction, and this dependence is observed for all S:V ratios from 1:1 to 1:7. Besides, a possibility to use some saturated hydrocarbons, wherein no sliming of thallium amalgam occurs, as a protective wash liquid has been shown.
Держатели документа:
WKU
Доп.точки доступа:
Baitasheva, G.U.
Myrzakhmetova, N.О.
Tagabergenova, Zh.A.
Gorbulicheva , E.P.
23.
Подробнее
24
N94
Nurdillayeva, R. N.
Dissolution of stanless steel in sodium chloride solution at polarization by non-stationary current. [Текст] / R. N. Nurdillayeva // News of national academy of sciences of the republic of Kazakhstan. . - 2021. - №3. - P. 75-81
ББК 24
Рубрики: chemistry
Кл.слова (ненормированные):
stainless steel -- titanium electrode -- alternating current -- iron (II) ions -- chromium (III)ions -- current density -- and current efficiency
Аннотация: Stainless steel is in great demand due to its mechanical strength, heat resistance, and resistance to corrosive environments. This article presents the result of a study of the electrochemical dissolution behavior of a stainless steel electrode (12X18H10T) at polarization by 50 Hz alternating current in a neutral medium (NaCl). Preliminary experiments have shown that the main processes do not take place when two stainless steel electrodes are polarized with an alternating current. It was observed that by the polarization of the “stainless steel – titanium” pair electrodes with alternating current, the alloy is intensively dissolved with the formation of iron (II) and chromium (III) ions. This is due to the "valve" properties of the oxide layer formed on the surface of the titanium electrode. A change in the value of the current density of the titanium and steel electrodes significantly affects the process of electrochemical dissolution of the alloy. At high current densities, the dissolution rate of the alloy decreases due to the deterioration of the current correcting properties of titanium. With an increase in the electrolyte concentration, the current efficiency is reduced as salt passivation occurs. A maximum value of the current efficiency of dissolution of stainless steel was observed at a current frequency of 50 Hz. High frequencies of the alternating current do not provide an adjustable duration of the anodic half-cycle for the oxidation reaction due to the frequent change of half-cycles of the alternating current. It was observed that increasing the temperature of the electrolyte reduces the current efficiency of the electrochemical dissolution of stainless steel electrodes. The effects of main electrochemical parameters on the electrolysis process have been investigated, and the optimal conditions of the alloy dissolution were established (іТі = 60 kA/m2, іSS = 800 A/m2, [NaCl] = 2.0 M, t = 30, ν = 50 Hz.).
Держатели документа:
WKU
Доп.точки доступа:
Sauirbay, Zh.G.
Bayeshov, A.B.
N94
Nurdillayeva, R. N.
Dissolution of stanless steel in sodium chloride solution at polarization by non-stationary current. [Текст] / R. N. Nurdillayeva // News of national academy of sciences of the republic of Kazakhstan. . - 2021. - №3. - P. 75-81
Рубрики: chemistry
Кл.слова (ненормированные):
stainless steel -- titanium electrode -- alternating current -- iron (II) ions -- chromium (III)ions -- current density -- and current efficiency
Аннотация: Stainless steel is in great demand due to its mechanical strength, heat resistance, and resistance to corrosive environments. This article presents the result of a study of the electrochemical dissolution behavior of a stainless steel electrode (12X18H10T) at polarization by 50 Hz alternating current in a neutral medium (NaCl). Preliminary experiments have shown that the main processes do not take place when two stainless steel electrodes are polarized with an alternating current. It was observed that by the polarization of the “stainless steel – titanium” pair electrodes with alternating current, the alloy is intensively dissolved with the formation of iron (II) and chromium (III) ions. This is due to the "valve" properties of the oxide layer formed on the surface of the titanium electrode. A change in the value of the current density of the titanium and steel electrodes significantly affects the process of electrochemical dissolution of the alloy. At high current densities, the dissolution rate of the alloy decreases due to the deterioration of the current correcting properties of titanium. With an increase in the electrolyte concentration, the current efficiency is reduced as salt passivation occurs. A maximum value of the current efficiency of dissolution of stainless steel was observed at a current frequency of 50 Hz. High frequencies of the alternating current do not provide an adjustable duration of the anodic half-cycle for the oxidation reaction due to the frequent change of half-cycles of the alternating current. It was observed that increasing the temperature of the electrolyte reduces the current efficiency of the electrochemical dissolution of stainless steel electrodes. The effects of main electrochemical parameters on the electrolysis process have been investigated, and the optimal conditions of the alloy dissolution were established (іТі = 60 kA/m2, іSS = 800 A/m2, [NaCl] = 2.0 M, t = 30, ν = 50 Hz.).
Держатели документа:
WKU
Доп.точки доступа:
Sauirbay, Zh.G.
Bayeshov, A.B.
24.
Подробнее
24
Z63
Zhumabek, M.
Ni-Al-Mg-Mn composite catalysts for partial oxidation of natural gas. [Текст] / M. Zhumabek, G. N. Kaumenova, A. Manabayeva, R. O. Sarsenova, S. O. Kotov // News of national academy of sciences of the republic of Kazakhstan. . - 2021. - №4. - P. 19-26
ББК 24
Рубрики: chemistry
Кл.слова (ненормированные):
catalytic oxidation -- methane -- synthesis-gas -- nickel -- magnesium
Аннотация: the problem of rational utilization of natural and associated petroleum gases and the cessation of their flaring is one of the acute and unresolved environmental problems. The aim of this work is to develop effective thermally stable catalysts ofa new generation for the processes of oxidative conversion of light alkanes of natural and associated gas into synthesis gas. The results of partial oxidation of the methane of natural gas on the catalysts prepared by solution combustion synthesis are presented. Investigation of the activity of catalysts produced from initial mixture of Ni(NO3)2-Al(NO3)3-Mg(NO3)2-Mn(NO3)2+ urea of different composition was carried out for the production of synthesis-gas. It was found that the optimal conditions for producing of synthesis-gas are: CH4conversion higher than 95%, yield of target products: Н2-97 -99% and СО -40 -43%, Т = 900оС, space velocity –2500 and 6500 h-1. The catalysts were studied by X-ray diffraction, transmission electron microscopy, specific surface area, pore volume and average pore diameter. The presence in the catalysts of simple and mixed oxides, metal aluminates and spinel-type structures, the presence of which contributes to the active work of catalysts for oxidativeconversion of CH4, has been established.
Держатели документа:
WKU
Доп.точки доступа:
Kaumenova, G.N.
Manabayeva, A.
Sarsenova, R.O.
Kotov, S.O.
Z63
Zhumabek, M.
Ni-Al-Mg-Mn composite catalysts for partial oxidation of natural gas. [Текст] / M. Zhumabek, G. N. Kaumenova, A. Manabayeva, R. O. Sarsenova, S. O. Kotov // News of national academy of sciences of the republic of Kazakhstan. . - 2021. - №4. - P. 19-26
Рубрики: chemistry
Кл.слова (ненормированные):
catalytic oxidation -- methane -- synthesis-gas -- nickel -- magnesium
Аннотация: the problem of rational utilization of natural and associated petroleum gases and the cessation of their flaring is one of the acute and unresolved environmental problems. The aim of this work is to develop effective thermally stable catalysts ofa new generation for the processes of oxidative conversion of light alkanes of natural and associated gas into synthesis gas. The results of partial oxidation of the methane of natural gas on the catalysts prepared by solution combustion synthesis are presented. Investigation of the activity of catalysts produced from initial mixture of Ni(NO3)2-Al(NO3)3-Mg(NO3)2-Mn(NO3)2+ urea of different composition was carried out for the production of synthesis-gas. It was found that the optimal conditions for producing of synthesis-gas are: CH4conversion higher than 95%, yield of target products: Н2-97 -99% and СО -40 -43%, Т = 900оС, space velocity –2500 and 6500 h-1. The catalysts were studied by X-ray diffraction, transmission electron microscopy, specific surface area, pore volume and average pore diameter. The presence in the catalysts of simple and mixed oxides, metal aluminates and spinel-type structures, the presence of which contributes to the active work of catalysts for oxidativeconversion of CH4, has been established.
Держатели документа:
WKU
Доп.точки доступа:
Kaumenova, G.N.
Manabayeva, A.
Sarsenova, R.O.
Kotov, S.O.
25.
Подробнее
24
I-32
Ibrayev, M. K.
Obtaining of water -soluble chelate forms of calcium and magnesium humate. [Текст] / M. K. Ibrayev // News of national academy of sciences of the republic of Kazakhstan. . - 2021. - №4. - P. 27-31
ББК 24
Рубрики: chemistry
Кл.слова (ненормированные):
calcium and magnesium humates -- chelate comple -- fertilizer -- crop production
Аннотация: this article analyzes the method of obtaining water-soluble chelated forms of calcium and magnesium humates for use as additives in the cultivation of agricultural crops. Humic substances, in turn, are an environmentally friendly, as well as an affordable type of sorbents. In the near future, humic substances are increasingly used in various sectors of agriculture. They are in the form of soluble humates, with progress being used as stabilizers of clay mixtures, which are used in oil drilling, as well as for the production of dyes for wood species. And very promising is the introduction of humic acids in the form of soluble humates in the rural economy as growth stimulants.
Держатели документа:
WKU
Доп.точки доступа:
Issabayeva, M.B.
Tusupova, A.S.
Amanzholova, А.S.
Kuandykova , A.A.
I-32
Ibrayev, M. K.
Obtaining of water -soluble chelate forms of calcium and magnesium humate. [Текст] / M. K. Ibrayev // News of national academy of sciences of the republic of Kazakhstan. . - 2021. - №4. - P. 27-31
Рубрики: chemistry
Кл.слова (ненормированные):
calcium and magnesium humates -- chelate comple -- fertilizer -- crop production
Аннотация: this article analyzes the method of obtaining water-soluble chelated forms of calcium and magnesium humates for use as additives in the cultivation of agricultural crops. Humic substances, in turn, are an environmentally friendly, as well as an affordable type of sorbents. In the near future, humic substances are increasingly used in various sectors of agriculture. They are in the form of soluble humates, with progress being used as stabilizers of clay mixtures, which are used in oil drilling, as well as for the production of dyes for wood species. And very promising is the introduction of humic acids in the form of soluble humates in the rural economy as growth stimulants.
Держатели документа:
WKU
Доп.точки доступа:
Issabayeva, M.B.
Tusupova, A.S.
Amanzholova, А.S.
Kuandykova , A.A.
26.
Подробнее
24
C51
Chernyakova, R. M.
Sorption of manganese (II) and vanadium (IV) cations by tagan bentonite in an aqueous medium. [Текст] / R. M. Chernyakova, U. Zh. Jussipbekov, G. Sh. Sultanbayeva, R. A. Kaiynbayeva , N. N. Kozhabekova // News of national academy of sciences of the republic of Kazakhstan. . - 2021. - №4. - P. 68-74
ББК 24
Рубрики: chemistry
Кл.слова (ненормированные):
bentonite -- montmorillonite -- sorption -- desorption -- degree of sorption -- Mn2 +and V4 +cations
Аннотация: the process of sorption of Mn2 +and V4 +cations by bentonite of the Tagan deposit studied depending on various factors (T, oC; τ, min; S: L ratio; CMnand CV, mg/l). It was found that bentonite exhibits sorption properties with respect to the studied cations in a wide range of pH values (from 1 to 10). The highest degree of their sorption is achieved at the consumption of bentonite 1.5 g per 100 mass. p.of metal-containing solution. The influence of the nature of the cation on the sorption capacity of Tagan bentonite was established. The most intense increase in the degree of sorption of manganese (II) occurs in 15 min with an increase in temperature to 35оС.The highest degree of sorption of V4 +cations is achieved in 60 min at 25°C in weakly concentrated vanadium-containing solutions (50 mg/l V4 +). Bentonite from the Tagandeposit exhibits a lower sorption capacity with respect to V4 +cations as compared to Mn2 +cations, which is due to the nature of the cation.
Держатели документа:
WKU
Доп.точки доступа:
Jussipbekov, U.Zh.
Sultanbayeva, G.Sh.
Kaiynbayeva , R.A.
Kozhabekova , N.N.
C51
Chernyakova, R. M.
Sorption of manganese (II) and vanadium (IV) cations by tagan bentonite in an aqueous medium. [Текст] / R. M. Chernyakova, U. Zh. Jussipbekov, G. Sh. Sultanbayeva, R. A. Kaiynbayeva , N. N. Kozhabekova // News of national academy of sciences of the republic of Kazakhstan. . - 2021. - №4. - P. 68-74
Рубрики: chemistry
Кл.слова (ненормированные):
bentonite -- montmorillonite -- sorption -- desorption -- degree of sorption -- Mn2 +and V4 +cations
Аннотация: the process of sorption of Mn2 +and V4 +cations by bentonite of the Tagan deposit studied depending on various factors (T, oC; τ, min; S: L ratio; CMnand CV, mg/l). It was found that bentonite exhibits sorption properties with respect to the studied cations in a wide range of pH values (from 1 to 10). The highest degree of their sorption is achieved at the consumption of bentonite 1.5 g per 100 mass. p.of metal-containing solution. The influence of the nature of the cation on the sorption capacity of Tagan bentonite was established. The most intense increase in the degree of sorption of manganese (II) occurs in 15 min with an increase in temperature to 35оС.The highest degree of sorption of V4 +cations is achieved in 60 min at 25°C in weakly concentrated vanadium-containing solutions (50 mg/l V4 +). Bentonite from the Tagandeposit exhibits a lower sorption capacity with respect to V4 +cations as compared to Mn2 +cations, which is due to the nature of the cation.
Держатели документа:
WKU
Доп.точки доступа:
Jussipbekov, U.Zh.
Sultanbayeva, G.Sh.
Kaiynbayeva , R.A.
Kozhabekova , N.N.
27.
Подробнее
24.1
O-52
Omirzak, A.
Laboratory work in the elective course ''PracticalLab'' as a means of developing motivation for professional activity of alumni. [Текст] / A. Omirzak // Химия мектепте. - 2023. - №3. - Б. 12-14
ББК 24.1
Рубрики: chemistry
Кл.слова (ненормированные):
elective course -- laboratory work -- practical knowledge -- alumni -- chemistry lesson
Аннотация: This article highlights concerns with a suggested methodology of teaching chemistry that includes practical knowledge.
Держатели документа:
WKU
Доп.точки доступа:
Kishibaev, K.
O-52
Omirzak, A.
Laboratory work in the elective course ''PracticalLab'' as a means of developing motivation for professional activity of alumni. [Текст] / A. Omirzak // Химия мектепте. - 2023. - №3. - Б. 12-14
Рубрики: chemistry
Кл.слова (ненормированные):
elective course -- laboratory work -- practical knowledge -- alumni -- chemistry lesson
Аннотация: This article highlights concerns with a suggested methodology of teaching chemistry that includes practical knowledge.
Держатели документа:
WKU
Доп.точки доступа:
Kishibaev, K.
28.
Подробнее
24.1
T34
Temirtassova, A. E.
Gamifying Chemistry Education: The Impact of Gaming Platforms on Teaching and Learning. [Текст] / A. E. Temirtassova // Химия мектепте. - 2023. - №5. - Б. 15-20
ББК 24.1
Рубрики: chemistry
Кл.слова (ненормированные):
General chemistry -- learning -- kahoot -- quizizz -- blended learning -- gamification -- chemical quizizz -- educational change
Аннотация: This article explores how gaming platforms can improve the quality of teaching in chemistry.
Держатели документа:
WKU
T34
Temirtassova, A. E.
Gamifying Chemistry Education: The Impact of Gaming Platforms on Teaching and Learning. [Текст] / A. E. Temirtassova // Химия мектепте. - 2023. - №5. - Б. 15-20
Рубрики: chemistry
Кл.слова (ненормированные):
General chemistry -- learning -- kahoot -- quizizz -- blended learning -- gamification -- chemical quizizz -- educational change
Аннотация: This article explores how gaming platforms can improve the quality of teaching in chemistry.
Держатели документа:
WKU
Страница 3, Результатов: 28