scholarly journals The content of manganese in soddy brown soils of the Transcarpathian Mountain Valleys

2015 ◽  
Vol 16 (1-2) ◽  
pp. 60-65
Author(s):  
E. P. Tkach
Keyword(s):  
Soil Solution ◽  
Humus Horizon ◽  
Fulvic Acids ◽  
Climatic Conditions ◽  
Water Soluble ◽  
Parent Rock ◽  
Acetate Buffer Solution ◽  
Buffer Solution ◽  
Mobile Forms ◽  
Mass Spectrometery

The soil covering of Transcarpathia, which is used for cultivation of crops, is rather heterogeneous as to genetic features of soils. This is mostly caused by the climatic conditions of corresponding natural zones. Brown mountain soils, soddy brown soils, meadow brown soils and mountain meadow soils have originated in mountainous areas on mountain ranges and slopes of different altitude, which are different in terms of mechanical makeup and are well drained. They are characterized by high content of inaccessible humus (in which fulvic acids predominate), acid reaction of soil solution and evident diversity in provision of mobile forms of nourishing chemicals. On the average, the reaction of soil solution is 4,60 pH of a salt solution, in the case of hydrolytic acidity – 4, 28 me/100g of soil, which characterizes them as semi-acidic. The aim of our thesis is to research the level of manganese, which is one of essential and toxic elements for plants, depending on its concentration in soil, in soddy brown soils of the mountainous zone of Thranscarpathia, and also its distribution in profile of soil horizons. To carry out this aim, samples of soil were chosen by random selection. Total manganese in the soil was determined by the method of mass spectrometery. The samples were extracted by hydrogen peroxide, chlorohydric and azotic acids (ext. p.). Dissolution of the samples was carried out using microwave sample preparation system. Active forms of manganese were extracted by generally accepted extragents: water-soluble extragent – deionized water; free forms of manganese – ammonium acetate buffer solution рН 4.8 according to M. K. Krupskyi and H. М. Alexandrova. Afterwards, the samples of soil were analysed using the method of mass spectrometery. According to the results of the research, the max. total of the manganese is observed in the mineral upper humus-accumulative horizon, but if you make a transition to the parent rock, it decreases. According to the quantitative research on determining free forms of manganese, it can be observed that soddy brown soils of the researched region are provided with the mobile forms of manganese both in the upper humus horizon and in lower transitional humus horizon. Moreover, the humus horizon of the observed region has a high content of mobile forms of manganese, which constitutes >20,1, and in the transitional horizon to the parent rock the provision index is high. A considerable increase in the water-soluble manganese in the upper humus horizon was also observed. Its concentration is considerably decreased with a transition to the lower humus horizon. The research data confirms that soddy brown soils of the observed region are contaminated with manganese compounds.

scholarly journals Mobile Forms of Gold and Pathfinder Elements in Surface Sediments at the Novye Peski Gold Deposit and in the Piilola Prospecting Area (Karelia Region)

Minerals ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 34 ◽  
Author(s):  
Vera Korshunova ◽  
Marina Charykova
Keyword(s):  
Organic Matter ◽  
Gold Deposit ◽  
Surface Sediments ◽  
Gold Mineralization ◽  
Total Content ◽  
Fulvic Acids ◽  
Water Soluble ◽  
Mobile Form ◽  
Mobile Forms ◽  
Pathfinder Elements

The success of prospecting for gold deposit in overburdened areas based on the using of secondary dispersion haloes mostly depends on the chosen method of geochemical survey (sampling horizon, sample preparation for analysis, etc.). At the same time, the geochemistry of gold in the supergene zone is insufficiently studied, especially it’s migration and concentration in association with other elements in surface sediments due to weathering of gold-bearing ore. The main aim of the study presented in this paper is the determination of mobile forms of gold and pathfinder elements (As, Cu, Ni, Ag, Zn, Pb, Se, Sb, Mo, Bi, and Te) in podzol soil and moraine in the areas of Karelia region with known gold mineralization. As a result of conducted experiments it was determined that the main mobile forms of gold are water-soluble and bound to organic matter, while pathfinder elements bound preferably to Fe and Mn(hydr)oxides and to organic matter. As gold and some pathfinders bind with organic matter, this form was considered in more detail, and the elements’ interaction with humic and fulvic acids was investigated. In addition, it was determined that the studied elements are quite “mobile” because the percentage of the mobile form in their total content was mostly more than 50%. The main features of the elements’ migration and concentration were identified in surface sediments of the study areas.

Electrocatalytic reactions of dioxygen and nitric oxide with reduced (nitrosyl) cobalt porphyrins — cyclic voltammetry and computational chemistry

2011 ◽  
Vol 15 (02) ◽  
pp. 99-105 ◽  
Author(s):  
John A. Goodwin ◽  
Tigran S. Kurtikyan
Keyword(s):  
Nitric Oxide ◽  
Cyclic Voltammetry ◽  
Catalytic Reduction ◽  
Reduction Reaction ◽  
Water Soluble ◽  
Acetate Buffer Solution ◽  
Buffer Solution ◽  
Model Complexes ◽  
Reducing Conditions ◽  
Catalytic Intermediates

Water-soluble cationic cobalt(tetra(N-methyl-pyridyl)porphyrins, CoTMpyP(4) and CoTMpyP(2) and the β-pyrrole octabrominated derivative CoTMpyP(4)Br8 have been studied by cyclic voltammetry under aqueous aerobic conditions at pH of 4.0 with and without addition of nitrite to explore their ability to catalyze the reduction of dioxygen. The porphyrins and their nitro/nitrosyl derivatives were studied in aqueous acetate buffer solution at a solid silver electrode and then also as they were immobilized in Nafion® film loaded with silver nanoparticles which provided electrical conductivity. Under these reducing conditions with nitrite in solution, coordinated nitrite appears to undergo an oxo-transfer/reduction reaction resulting in the formation of the nitrosyl ligand. The reaction of the nitrosyl complex allows a short-lived electrocatalytic reduction reaction with dioxygen before NO is lost from the complex by dissociation. The thermodynamics of the reactions and possible catalytic intermediates in the reduction of dioxygen were studied by DFT (BP/6-31G*) computations. An unusual N -bound cyclic NO3- structure was obtained in the optimized geometries for the product of reduced nitrosyl porphyrins and dioxygen in the model complexes and for [CoTMpyP(2)(NO-O2)]- . These structures are tentatively proposed to represent an intermediate in the mechanism of activation of dioxygen in catalytic reduction. DFT (BP/6-31G*) computations were also applied to probe thermodynamics and intermediates in the known catalytic reduction of NO to N2O by the reduced porphyrin under anaerobic conditions. Thermodynamics estimates suggest that reduction occurs through coordinated NO in the reduced porphyrin species similar to cytochrome P450nor (nitric oxide reductase), but the detailed mechanism is not clear.

Polarographic Determination of Zinc in Compounded Rubber

1950 ◽  
Vol 23 (4) ◽  
pp. 975-980
Author(s):  
F. C. J. Poulton ◽  
L. Tarrant
Keyword(s):  
Zinc Oxide ◽  
Ammonium Acetate ◽  
Potassium Thiocyanate ◽  
Acetate Buffer Solution ◽  
Acid Electrolyte ◽  
Buffer Solution ◽  
Ammonium Acetate Buffer ◽  
Ammonium Acetate Buffer Solution ◽  
Gravimetric Procedure

Abstract Reasons are advanced for the unsatisfactory nature of some of the older methods for the determination of very small amounts of zinc in compounded rubber, particularly in latex mixings. The polarographic technique offers a possible solution, but most of the commoner electrolytes for the electroreduction of this metal are alkaline, and give rise to similar errors as are met in the gravimetric procedure. The development of a suitable acid electrolyte was therefore undertaken, and ways of dealing with likely interferences were examined. The electroltye finally recommended is a potassium thiocyanate-ammonium acetate buffer solution; iron, when present, is reduced to the ferrous condition by potassium iodide. The method was used to determine zinc oxide in a series of mixings of known composition ranging from 0.8 to 40 per cent. In all except the highest proportions of zinc oxide, the figures obtained agree well with the theoretical.

Study on the Inclusion Behavior of Cucurbit [n] uril with Phenylalanine

2011 ◽  
Vol 197-198 ◽  
pp. 1153-1156
Author(s):  
Ning Chen ◽  
Ya Bin Li
Keyword(s):  
1H Nmr ◽  
Interaction Mechanism ◽  
Acetate Buffer Solution ◽  
Molar Ratio ◽  
High Concentration ◽  
Buffer Solution ◽  
Visible Absorption ◽  
Nmr Spectrum ◽  
Application Range ◽  
Uv Visible

The characteristics of host-guest complexes between cucurbit[n]uril (CB [n]) and phenylalanine were investigated by UV-visible absorption spectroscopy in acetate buffer solution at room temperature. It was found that the UV-visible absorption increased steadily with constantly dropping the high concentration of cucurbit[6]uril (CB [6]) and cucurbit[8]uril (CB [8]) in the phenylalanine solution which indicates that there are some interaction betweenCB [n] and phenylalanine.Then CB [6] and phenylalanine at molar ratio of 1:1 to weigh while CB [8] and phenylalanine at molar ratio of 1:2, respectively, are both demonstrated by 1H NMR spectra. 1H NMR spectrum of complexes was obtained, indicating an enthalpic driving force for host-guest complexes. The possible interaction mechanism and inclusion mode were also discussed. This work may extend the application range of CB [n] in supramolecular and pharmaceutical analysis.

Enzymatic hydrolysis of chitosan in acetate buffer solution

2015 ◽  
Vol 88 (4) ◽  
pp. 647-651 ◽  
Author(s):  
V. V. Chernova ◽  
A. S. Shurshina ◽  
M. V. Bazunova ◽  
E. I. Kulish
Keyword(s):  
Enzymatic Hydrolysis ◽  
Acetate Buffer ◽  
Acetate Buffer Solution ◽  
Buffer Solution ◽  
Hydrolysis Of

Concentration and Nitrogen Stocks in the Soils of Semi-Arid Landscapes of Kizlyar Pastures

2020 ◽  
pp. 66-74
Author(s):  
Tatiana A. Asvarova ◽  
Gasan N. Gasanov ◽  
Kabirat B. Gimbatova ◽  
Kamil M. Hajiev ◽  
Rashid R. Bashirov ◽  
...  
Keyword(s):  
Total Nitrogen ◽  
Humus Horizon ◽  
Control Area ◽  
Climatic Conditions ◽  
Chestnut Soils ◽  
Number Of Species ◽  
Current State ◽  
Low Degree ◽  
Arid Landscapes ◽  
Semi Arid

The results of research on the current state of the nitrogen fund (reserve regime) the Kizlyar pastures. It was found that the total nitrogen ranges from 0.15-0.2 %, nitrogen easily hydrolyzed from 2.4-5.3 mg/100g in light-chestnut, meadow-chestnut soils and saline typical, and has a medium and low degree of security. The humus horizon is more enriched with nitrogen on soils of meadow-chestnut and light-chestnut compared to typical saline. N and C reserves in the soil in spring are 5.0 and 13.4 t/ha, respectively, and in autumn N and C reserves are 1.5 times lower, due to decrease the number of species and projected coverage up to 40-50% of phytocenoses in autumn, and also depends on the climatic conditions of the annual seasonality. In the control area with intensive grazing, nitrogen and carbon reserves in the soil are 1.6-1.8 times lower.

scholarly journals COMPOSITION, MICROSTRUCTURE AND PROPERTIES OF QUATERNARY CLAYS OF THE PRIKHANKAYSKAYA DEPRESSION (PRIMORYE)

2019 ◽  
Vol 14 (1) ◽  
pp. 20-34
Author(s):  
T. G. RYASHCHENKO ◽  
N. N. UKHOVA ◽  
S. I. SHTELMAKH ◽  
N. I. BELYANINA ◽  
P. S. BELYANIN
Keyword(s):  
Clay Minerals ◽  
Laboratory Data ◽  
Chemical Properties ◽  
Exchange Capacity ◽  
Climatic Conditions ◽  
Water Soluble ◽  
Laboratory Studies ◽  
Microstructural Parameters ◽  
Physical Chemical ◽  
Study Results

The article considers the study results of composition, microstructure and physical-chemical properties of the quaternary clays of the Prikhankayskaya depression in district of the lake Khanka (Primorye) on the example of air-dry samples of geological borehole 45-b in the range of 18–62 m. The objective of research was to obtain new information about the properties of widespread clay sediments in this area using geologic-lithological materials and laboratory data. The schematic geologic-lithological column was composed with the selection of various zones in the quaternary clay sediments section and the border with sediments of the Neogene System. The methodological scheme of laboratory studies of clays was proposed. This scheme includes the determination of chemical and microelement composition, clay minerals, contents of carbonates, water-soluble salts, mobile forms of aluminum oxide, humus, as well as microstructural parameters (method «Microstructure») and some physical-chemical properties. Geochemical coefficients (Kz, CIA, CIW, ICV) determined the degree of chemical maturity of clays and confirmed the results of palynological studies reflecting the fluctuations of the climatic conditions of their formation. For the group of toxic microelements for the first time the special indicator (Zc) was calculated. Which was the criterion for a degree of pollution of the clay sediments section. Clay minerals of the quaternary clays are represented by smectite and hydromica. The clear change in the mineral association was found when passing to the Neogene sediments (kaolinite prevails). The method «Microstructure» revealed the aggregated type of clays microstructure, the domination of the particles of coarse dust fraction among the primary (free) particles and the almost complete absence of the particles of fine-grained sand fraction, the participation of various fractions in the composition of aggregates. The variants of the formation of certain types of aggregates (on sizes) in the fluviolacustrine «khankayskiy» clays are presented. Solid part density, water resistance (soaking time), sedimentation volume, plasticity, relative swelling (samples-pastes) were determined using standard methods for clays. By special methods, the cation exchange capacity was measured and the calculated values of the plasticity index were obtained from forecasting formulas using the yield limit. The proposed methodological scheme of complex laboratory studies of clay sediments can be recommended for problematic geologic-lithological and engineering-geological sections.

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