152 research outputs found
ADAPTIVE AGRO-TECHNOLOGY OF FARMING NEW WINTER WHEAT VARIETY IN THE TERSKO-SULAK TERRITORY
Aim. The aim of the research was to improve the elements of agro-technology for cultivating new high-yielding varieties of winter wheat under conditions of the plain zone irrigation depending on the doses and the terms of introducing mineral nitrogen-phosphorus fertilizers.Methods. Research was carried out on chestnut heavy loamy soils. Sampling of soils and plants, as well as agrochemical properties of soils were determined according to standard generally accepted methods. Mathematical processing of data on the yield of cereals was carried out by analysis-of-variance method using computer technology.Results. Our studies showed that the most productive of the studied varieties was Grom, which, on average for three years (2012-2015) gave a grain yield of 7.6 t/ha with nitrogen-phosphorus fertilizers introduced at a dose of N180P100 against 5.6 t/ha in a similar version to the control during sowing of the Tanya variety. Vassa and Sila varieties were also inferior to Grom variety for yields, respectively, by 1.1 t/ha and 1.4 t / ha. It was also revealed that with the Grom variety, when applying an increased dose of mineral fertilizers (N180P100), on average for three years, the best indicators were by the area of the leaf surface (63.6 thousand m2/ha), photosynthetic index of crops was 2765.6 thousand m2/ha and net productivity of photosynthesis was 6.3 g/m2, day. For other varieties of winter wheat and doses of mineral fertilizers, these indicators were lower.Conclusion. In steady-state experiment, when studying the potential of new high-yielding varieties of winter wheat at different levels and times of introducing mineral nutrition, the Grom variety showed the best yields
Determination of optimal pressure parameters for the system of pulp microaeration dispersants in column flotation
The article presents the results of experiments intended to beneficiate gold-bearing mineral raw materials by column flotation with the use of micro aeration of pulp through a dispersant system. The influence of the pressure level in the pressure system of dispersants within the range from 202,65 to 1013,25 KPa was studied during the experiments. It was found that the parameter of 607,95 KPa enables to achieve the optimal balance of the precious metal mass yield and the content in the concentrate, with a final gold recovery of 87 %
ANALYSIS OF THE MAIN PROBLEMS OF THE STUDY AND MANAGEMENT MARKET TO PREMISES
They are considered main problems to segmenting market to premises and moving the real estate on him. It is motivated that correlation quality and cost realized object to premises must be balanced with buyer's ability of the consumers on corresponding to segment market. The offered managerial system operation, conducted on the market with real estates
ПОТЕНЦИОМЕТРИЧЕСКИЙ СЕНСОР ДЛЯ ОПРЕДЕЛЕНИЯ ИОНОВ ЦИНКА
One of the sensitive and inexpensive methods used for the analysis of water bodies is the ionometry, the development of which is associated with the introduction of new ion-selective electrodes into the practice of potentiometric analysis. An optimized composition of the membrane for the manufacturing of a zinc-selective electrode based on polyvinyl chloride modified with 2-mercaptobenzthiazole (MPVC) is proposed with the following ratio of ingredients (in wt. %): Polyvinyl chloride - 31.7; dioctyl sebacate - 66.3; potassium tetra-p-chlorophenylborate - 0.5; MPVH - 1.5. The working range of pH was established with a minimum potential drift, which was 1.5 - 3. The slope of the electrode function was calculated as 30.1 ± 0.3 mV. According to the dependence of the electrode potential for the selected composition of the membrane on the logarithm of the zinc ion concentration, it was found that the proposed model of the electrode operates in the concentration range of 1∙10-5 - 1∙10-1 mol / L, with a detection limit of 0.65 mg / l. The stabilization time of the potential within 1 mV was 15 - 20 s. The potentiometric coefficients of the selectivity of the zinc selective electrode with respect to various ions have been determined. The conditions for the determination of zinc using the obtained sensor in alloys and wastewater were proposed. The electrode with the membrane based on polyvinyl chloride modified with 2-mercaptobenzthiazole can be used as an alternative to the industrial electrode XC-Zn-001 for the determination of zinc ions in various objects. The obtained experimental data was close in accuracy to the results obtained by the atomic absorption methods, as well as the ionometry using the industrial electrode. In conclusion, the electrode with the membrane based on polyvinyl chloride modified with 2-mercaptobenzthiazole can be used as an alternative to XC-Zn-001.Key words: zinc selective electrode, modified polyvinyl chloride, ionometry, membrane, sensor DOI: http://dx.doi.org/10.15826/analitika.2021.25.3.002 POTENTIOMETRIC SENSOR FOR LEAD IONS DETERMINATION S. D. Tataeva, *R.Z. Zeynalov, K.E. MagomedovDagestan State University, ul. Gadzhieva, d. 43-a, g. Mahachkala,Respublika Dagestan, Russian FederationОдним из чувствительных и недорогих методов, применяемых для анализа водных объектов, является ионометрия, развитие которой связано с внедрением новых ионселективных электродов в практику потенциометрического анализа. Предложен оптимизированный состав мембраны для изготовления цинк-селективного электрода на основе поливинилхлорида модифицированного 2–меркаптобензтиазолом (МПВХ), с соотношением ингредиентов (в % мас.): поливинилхлорид – 31.7; диоктилсебацинат – 66.3; тетра-п-хлорфенилборат калия – 0.5; МПВХ – 1.5. Установлен рабочий диапазон рН с минимальным дрейфом потенциала, который составил 1.5 - 3. Рассчитана крутизна электродной функции 30.1 ± 0.3 мВ. По зависимости потенциала электрода для выбранного состава мембраны от логарифма концентрации ионов цинка установлено, что предлагаемая модель электрода работает в диапазоне концентраций 1∙10-5 – 1∙10-1 моль/л, с пределом обнаружения 0.65 мг/л. Время стабилизации потенциала в пределах 1 мВ составило 15-20 с. Определены потенциометрические коэффициенты селективности цинк-селективного электрода по отношению к различных ионам. Предложены условия определения цинка с помощью полученного сенсора в сплавах и сточной воде. Данный электрод с мембраной на основе поливинилхлорида модифицированного 2–меркаптобензтиазолом можно использовать как альтернативный промышленному электроду ХС-Zn-001 для определения ионов цинка в различных объектах. Полученные экспериментальные данные близки по точности результатам, полученным методами атомно-абсорбции, а также ионометрии с применением промышленного электрода. Таким образом, электрод с мембраной на основе поливинилхлорида модифицированного 2-меркаптобензтиазолом можно использовать как альтернативный ХС-Zn-001.Ключевые слова: цинк-селективный электрод, модифицированный полинилхлорид, ионометрия, мембрана, сенсорDOI: http://dx.doi.org/10.15826/analitika.2021.25.3.00
Intensification of copper leaching from heaps using biological oxidation
The article presents the results of experiments intended to leach copper from ore heaps of complex mineral composition biochemically. The processing of such heaps is complicated due to the presence of oxidized copper minerals among significant fragments of sulfide minerals and iron-calcium silicates. This factor does not allow to perform standard sulfuric acid leaching effectively without the use of additional oxidation catalysts, or to apply beneficiation methods for that kind of raw materials. Use of A. Ferrooxidans bacteria adapted to the composition of the copper dump, as a bio-catalytic agent, significantly accelerates the leaching process and increases the copper recovery degree into the productive solution
Intensification of copper leaching from heaps using biological oxidation
The article presents the results of experiments intended to leach copper from ore heaps of complex mineral composition biochemically. The processing of such heaps is complicated due to the presence of oxidized copper minerals among significant fragments of sulfide minerals and iron-calcium silicates. This factor does not allow to perform standard sulfuric acid leaching effectively without the use of additional oxidation catalysts, or to apply beneficiation methods for that kind of raw materials. Use of A. Ferrooxidans bacteria adapted to the composition of the copper dump, as a bio-catalytic agent, significantly accelerates the leaching process and increases the copper recovery degree into the productive solution
A study of the biohydrometallurgical method for extracting gold from flotation tailings
This paper shows the results of the comparative study of efficiency of gold extraction methods from technogenic flotation tails by agitation cyanidation and biooxidation followed by leaching. A representative sample of flotation tails was taken at gold extraction plant of Altyntau Kokshetau LLP. Experimentally, an increase in the efficiency of leaching gold from flotation tails during preliminary bacterial oxidation was found. By biochemical leaching, 72 % was extracted, which is 7 % more than using expensive sodium peroxide and 10 % more than using the traditional method of cyanidation
Research of biochemical gold recovery method using high-arsenic raw materials
This article contains the results of experiments to recover gold from complex mineral raw materials containing more than 15 % arsenic. Laboratory tests showed that standard cyanidation recovers only 26,4 % of gold into the solution. Additional oxidizing reagents used increase the leaching efficiency and enable to recover more than 40 % of gold during subsequent cyanidation. The efficiency has been established for replacement of cyanide with thiourea and thiosulfate solutions. 79,5 %, i.e. the maximum recovery rate, was found in the experiment with preliminary oxidation with T. Ferrooxidans, a bacterial culture, followed by leaching with a thiourea solution
Research of biochemical gold recovery method using high-arsenic raw materials
This article contains the results of experiments to recover gold from complex mineral raw materials containing more than 15 % arsenic. Laboratory tests showed that standard cyanidation recovers only 26,4 % of gold into the solution. Additional oxidizing reagents used increase the leaching efficiency and enable to recover more than 40 % of gold during subsequent cyanidation. The efficiency has been established for replacement of cyanide with thiourea and thiosulfate solutions. 79,5 %, i.e. the maximum recovery rate, was found in the experiment with preliminary oxidation with T. Ferrooxidans, a bacterial culture, followed by leaching with a thiourea solution
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