Surface Layers in Alkaline Media: Nickel Hydrides on Metallic Nickel Electrodes

2013 ◽  
Vol 50 (31) ◽  
pp. 165-179 ◽  
Author(s):  
D. S. Hall ◽  
C. Bock ◽  
B. R. MacDougall
Keyword(s):  
Alkaline Media ◽  
Metallic Nickel ◽  
Surface Layers ◽  
Nickel Electrodes ◽  
Nickel Hydrides

Influences on the Hydrophobicity of Concrete Surfaces Treated with Alkyl Trialkoxysilanes

2014 ◽  
Vol 20 (6) ◽  
pp. 405-412
Author(s):  
U. Antons ◽  
M. Raupach ◽  
O. Weichold
Keyword(s):  
Uv Radiation ◽  
Cement Hydration ◽  
Alkaline Media ◽  
Water Repellent ◽  
Portland Cement Concrete ◽  
Accelerated Carbonation ◽  
Surface Layers ◽  
Hydrophobic Layer ◽  
Furnace Slag

Abstract The paper focuses on how alkaline media, UV radiation, and carbonation as well as on-going cement hydration affects hydrophobic treatments of concrete and influences the properties of these water-repellent layers. Single-sided nuclear magnetic resonance measurements show that layers formed by impregnating samples with alkyl trialkoxysilanes are stable even under long-term exposure to alkaline solution and UV radiation, with the damage of the latter being limited to the topmost surface layers. Microstructural changes during accelerated carbonation of blast furnace slag cement based concrete have a major impact on the hydrophobic layer properties, while the carbonation of Portland cement concrete has no influence. On-going hydration additionally influences the hydrophobic layer properties.

The Electrochemical Impedance of Porous Nickel Electrodes in Alkaline Media: I . Experimental Studies

1991 ◽  
Vol 138 (5) ◽  
pp. 1353-1358 ◽  
Author(s):  
S. D. Bhakta ◽  
D. D. Macdonald ◽  
B. G. Pound ◽  
M. Urquidi‐Macdonald
Keyword(s):  
Electrochemical Impedance ◽  
Experimental Studies ◽  
Alkaline Media ◽  
Porous Nickel ◽  
Nickel Electrodes

Formation of nickel hydrides by hydrogen evolution in alkaline media

1998 ◽  
Vol 442 (1-2) ◽  
pp. 125-135 ◽  
Author(s):  
M Bernardini ◽  
N Comisso ◽  
G Davolio ◽  
G Mengoli
Keyword(s):  
Hydrogen Evolution ◽  
Alkaline Media ◽  
Nickel Hydrides

Formation of nickel hydrides by hydrogen evolution in alkaline media: effect of temperature

1998 ◽  
Vol 457 (1-2) ◽  
pp. 205-219 ◽  
Author(s):  
Michele Bernardini ◽  
Nicola Comisso ◽  
Giuliano Mengoli ◽  
Livio Sinico
Keyword(s):  
Hydrogen Evolution ◽  
Alkaline Media ◽  
Effect Of Temperature ◽  
Media Effect ◽  
Nickel Hydrides

Electrochemical determination of sulphide at nickel electrodes in alkaline media: a new electrochemical sensor

2003 ◽  
Vol 88 (3) ◽  
pp. 320-328 ◽  
Author(s):  
Debora Giovanelli ◽  
Nathan S. Lawrence ◽  
Li Jiang ◽  
Timothy G.J. Jones ◽  
Richard G. Compton
Keyword(s):  
Electrochemical Sensor ◽  
Electrochemical Determination ◽  
Alkaline Media ◽  
Nickel Electrodes

Pressure-induced magnetic transition in metallic nickel hydrides byab initiopseudopotential plane-wave calculations

2006 ◽  
Vol 74 (5) ◽  
Author(s):  
Xiaojiao San ◽  
Yanming Ma ◽  
Tian Cui ◽  
Wenjiong He ◽  
Bai Han ◽  
...  
Keyword(s):  
Plane Wave ◽  
Magnetic Transition ◽  
Metallic Nickel ◽  
Nickel Hydrides

Comments on collision mechanics in ring systems

1984 ◽  
Vol 75 ◽  
pp. 407-422
Author(s):  
William K. Hartmann
Keyword(s):  
Asteroid Belt ◽  
Surface Erosion ◽  
Surface Layers ◽  
Ring Systems ◽  
Eclipse Observations ◽  
Saturn’S Rings ◽  
Saturn's Rings

ABSTRACTThe nature of collisions within ring systems is reviewed with emphasis on Saturn's rings. The particles may have coherent icy cores and less coherent granular or frosty surface layers, consistent with thermal eclipse observations. Present-day collisions of such ring particles do not cause catastrophic fragmentation of the particles, although some minor surface erosion and reaccretion is possible. Evolution by collisional fragmentation is thus not as important as in the asteroid belt.

Applications of Photoelectron Microscopy

1976 ◽  
Vol 34 ◽  
pp. 506-507
Author(s):  
William J. Baxter
Keyword(s):  
Electron Microscopy ◽  
Thermal Decomposition ◽  
Chemical Composition ◽  
Ultraviolet Radiation ◽  
Thin Layer ◽  
Edge Effects ◽  
Electron Optics ◽  
Surface Layers ◽  
Crystalline Orientation ◽  
Fluorescent Screen

In this form of electron microscopy, photoelectrons emitted from a metal by ultraviolet radiation are accelerated and imaged onto a fluorescent screen by conventional electron optics. image contrast is determined by spatial variations in the intensity of the photoemission. The dominant source of contrast is due to changes in the photoelectric work function, between surfaces of different crystalline orientation, or different chemical composition. Topographical variations produce a relatively weak contrast due to shadowing and edge effects.Since the photoelectrons originate from the surface layers (e.g. ∼5-10 nm for metals), photoelectron microscopy is surface sensitive. Thus to see the microstructure of a metal the thin layer (∼3 nm) of surface oxide must be removed, either by ion bombardment or by thermal decomposition in the vacuum of the microscope.

Etching of Polymers by Oxygen Plasma

1968 ◽  
Vol 26 ◽  
pp. 408-409
Author(s):  
Virgil Peck ◽  
W. L. Carter
Keyword(s):  
Molecular Weight ◽  
Oxygen Plasma ◽  
Flow Time ◽  
Microscopical Study ◽  
Surface Layers ◽  
Organic Vapors ◽  
Sample Position ◽  
Accuracy Of Measurement ◽  
Bulk Polymers ◽  
Electron Microscopical

Any electron microscopical study of the morphology of bulk polymers has throughout the years been hampered by the lack of any real ability to produce meaningful surface variations for replication. True etching of polymers should show crystalline and amorphous regions in some form of relief. The use of solvents, acids, organic vapors, and inert ion bombardment to etch samples has proved to be useful only in limited applications. Certainly many interpretations of these results are subject to question.The recent use of a radiofrequency (R. F.) plasma of oxygen to degrade and remove organic material with only minor heating has opened a new possibility for etching polymers. However, rigid control of oxygen flow, time, current, and sample position are necessary in order to obtain reproducible results. The action is confined to surface layers; the molecular weight of the polymer residue after heavy etching is the same as the molecular weight of the polymer before attack, within the accuracy of measurement.

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