The effect of ligands on contact exchange in the NdFeB–Cu2+–P2O
                                7
                                4-
                            –NH
                                4
                                +
                             system

In the NiFe/Ta/IrMn structures, the contributions of two types of exchange interactions are separated at the NiFe/IrMn interface, partially separated by non-magnetic Ta fragments. The first “contact” exchange corresponds to the NiFe/IrMn fragments. The second “interlayer” exchange is provided by the Ta conduction electrons in the NiFe/Ta/IrMn fragments. A comparison of the temperature dependences of the exchange bias in heterostructures with varied Ta spacer at fixed parameters of the ferromagnetic layers allowed us to separate the contributions of the above types of exchange interactions and to establish their temperature dependences. The energies of the exchange interactions in the NiFe/IrMn and NiFe/Ta/IrMn fragments were determined.

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The aggregation of wheat rhizoplane fibrils and the accumulation of soil-bound cations

Canadian Journal of Botany ◽

10.1139/b75-202 ◽

1975 ◽

Vol 53 (16) ◽

pp. 1729-1735 ◽

Cited By ~ 28

Author(s):

Gary G. Leppard ◽

S. Ramamoorthy

Keyword(s):

Cell Walls ◽

Solid Phase ◽

Root Surface ◽

Surface Structures ◽

Soil Environment ◽

Wheat Roots ◽

Root Cells ◽

Contact Exchange ◽

Cation Uptake ◽

Fibril Aggregates

Some surface materials of roots can accumulate bound cations from the soil environment by contact exchange. This paper describes the physical relationships between rhizoplane fibril aggregates and other root surface structures in the zone of active cation uptake. Sheets and tufts of rhizoplane fibrils project from wheat roots and establish a discrete and intimate physical connection between root cell walls and the solid phase of the soil environment. These aggregates of fibrils may provide a direct channel for the movement of soil-bound cations to the surface of root cells. Consideration is given to a possible mechanism of extraction of soil-bound cations by rhizoplane fibrils and the transfer of these cations to the walls of cells actively engaged in cation uptake.

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Purification of concentrated waste water of pcb production from copper ions

Problems of Water supply Sewerage and Hydraulic ◽

10.32347/2524-0021.2021.35.11-20 ◽

2021 ◽

pp. 11-20

Author(s):

Olena Zoria ◽

Оleksiy Ternovtsev ◽

Dmytro Zoria

Keyword(s):

Ph Value ◽

Copper Ions ◽

Sewage Treatment ◽

Experimental Studies ◽

Precious Metals ◽

Rate Of Change ◽

Copper Extraction ◽

Contact Exchange ◽

Circulating Water ◽

Static Conditions

In modern conditions, it is important to create a comprehensive technology for processing wastewater containing copper compounds, with the disposal of precious metals, the organization of circulating water supply of the enterprise and obtaining safe for disposal sludge. Methods of sewage treatment of galvanic productions are considered. The results of experimental studies of the process of copper extraction from water by cementation on iron powder particles under static conditions are presented. The technological scheme of the reactor-cementator is given. The influence of various factors on the process of copper cementation – pH, concentration and ratio of iron and copper in the reaction mixture, contact time were studied. The time at which the greatest rate of change of residual copper concentration is observed is determined. The influence of the pH value of the cementation process was also determined. As a result of the obtained data, it is concluded that the concentration of hydrogen ions in the solution affects the course of the contact exchange reaction. The higher the acidity of the solution, the higher the recovery rate of copper. Promising directions for the creation of closed water circulation systems in the process of copper wastewater treatment are outlined.

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Study of the effect of electrolyte composition on adhesion and other properties of a coating-base system

Industrial laboratory Diagnostics of materials ◽

10.26896/1028-6861-2021-87-10-34-39 ◽

2021 ◽

Vol 87 (10) ◽

pp. 34-39

Author(s):

T. I. Devyatkina ◽

E. S. Belyaev ◽

V. V. Rogozhin ◽

M. V. Maksimov

Keyword(s):

Scratch Test ◽

Electrolyte Composition ◽

Test Method ◽

Multilayer Coatings ◽

Base System ◽

Surface Porosity ◽

Contact Exchange ◽

Sulfuric Acid Electrolyte ◽

Copper Coatings

Aluminum alloys with electroplated coatings and copper plated in particular gained multiple applications. However, pre-zincate treatment often fails to provide the desired adhesion of the coating. We present the results of studying the effect of the electrolyte composition on the adhesion and other properties of the coating-base system. It is shown that an electrolyte with a reduced content of sulfuric and phosphoric acids can be used for anodizing and the oxide films formed during anodizing are stable in the usual copper-plating sulfuric acid electrolyte which eliminates contact exchange and increases adhesion. The use of a modern scratch-test method provides numerical determination of the values of adhesion of copper coatings. The adhesion value depends on the surface porosity of the oxide film and on the type of anodized alloys. The results can be used to improve the technology of applying copper coatings, both as an independent coating and as an underlayer in multilayer coatings.

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