Approximate potential-distance relationship for clays

Soil Research ◽  
1980 ◽  
Vol 18 (4) ◽  
pp. 461 ◽  
Author(s):  
A Sridharan ◽  
MS Jayadeva
Keyword(s):  
Surface Potential ◽  
Clay Platelet ◽  
Conventional Procedure ◽  
Distance Relationship ◽  
New Procedures

The conventional procedure of determining the surface potential of clay platelet and the variation of potential with distance is lengthy and time consuming. Simplified graphical procedures using Gouy theory have been developed and presented. The new procedures are simple, accurate and very much less time consuming.

The effects of surface absorbed monolayer microdiffraction patterns

1988 ◽  
Vol 46 ◽  
pp. 680-681
Author(s):  
M. Pan ◽  
J.M. Cowley
Keyword(s):  
Surface Potential ◽  
Electron Probe ◽  
Potential Distribution ◽  
Crystal Surface ◽  
Normal Direction ◽  
Surface Image ◽  
Extended Surface ◽  
Gas Molecules ◽  
Surface Nature ◽  
Electron Microdiffraction

Electron microdiffraction patterns, obtained when a small electron probe with diameter of 10-15 Å is directed to run parallel to and outside a flat crystal surface, are sensitive to the surface nature of the crystals. Dynamical diffraction calculations have shown that most of the experimental observations for a flat (100) face of a MgO crystal, such as the streaking of the central spot in the surface normal direction and (100)-type forbidden reflections etc., could be explained satisfactorily by assuming a modified image potential field outside the crystal surface. However the origin of this extended surface potential remains uncertain. A theoretical analysis by Howie et al suggests that the surface image potential should have a form different from above-mentioned image potential and also be smaller by several orders of magnitude. Nevertheless the surface potential distribution may in practice be modified in various ways, such as by the adsorption of a monolayer of gas molecules.

TEM study of very thin InGaAsP layers grown by liquid-phase epitaxy

1990 ◽  
Vol 48 (4) ◽  
pp. 672-673
Author(s):  
N.A. Bert ◽  
A.O. Kosogov
Keyword(s):  
Liquid Phase ◽  
Liquid Phase Epitaxy ◽  
Chemical Vapor ◽  
Growth Conditions ◽  
Dark Field ◽  
Organic Chemical ◽  
Simple Liquid ◽  
Cross Sectional ◽  
Conventional Procedure ◽  
Double Heterostructures

The very thin (<100 Å) InGaAsP layers were grown not only by molecular beam epitaxy and metal-organic chemical vapor deposition but recently also by simple liquid phase epitaxy (LPE) technique. Characterization of their thickness, interfase abruptness and lattice defects is important and requires TEM methods to be used.The samples were InGaAsP/InGaP double heterostructures grown on (111)A GaAs substrate. The exact growth conditions are described in Ref.1. The salient points are that the quarternary layers were being grown at 750°C during a fast movement of substrate and a convection caused in the melt by that movement was eliminated. TEM cross-section specimens were prepared by means of conventional procedure. The studies were conducted in EM 420T and JEM 4000EX instruments.The (200) dark-field cross-sectional imaging is the most appropriate TEM technique to distinguish between individual layers in 111-v semiconductor heterostructures.

"Jedes starre Konzept ist schlecht und passt net' in diese Welt"

2007 ◽  
Vol 37 (148) ◽  
pp. 369-381 ◽  
Author(s):  
Wolfgang Ludwig-Mayerhofer ◽  
Ariadne Sondermann ◽  
Olaf Behrend
Keyword(s):  
Public Management ◽  
New Public Management ◽  
Qualitative Interviews ◽  
Unemployed People ◽  
Staff Members ◽  
Public Employment Service ◽  
New Public ◽  
Recent Reform ◽  
The Unemployed ◽  
New Procedures

The recent reform of the Bundesagentur fijr Arbeit, Germany's Public Employment Service (PES), has introduced elements of New Public Management, including internal controlling and attempts at standardizing assessments ('profiling' of unemployed people) and procedures. Based on qualitative interviews with PES staff, we show that standardization and controlling are perceived as contradicting the 'case-oriented approach' used by PES staff in dealing with unemployed people. It is therefore not surprising that staff members use considerable discretion when (re-)assigning unemployed people to one of the categories pre-defined by PES headquarters. All in all, the new procedures lead to numerous contradictions, which often result in bewilderment and puzzlement on the part of the unemployed.

Modeling on Effects of Charging Time and Recombination on Surface Potential Decay Crossover of LDPE

2016 ◽  
Vol 136 (2) ◽  
pp. 86-92 ◽  
Author(s):  
Daomin Min ◽  
Shengtao Li ◽  
Guochang Li ◽  
George Chen
Keyword(s):  
Surface Potential ◽  
Charging Time ◽  
Potential Decay

Politeness Strategies in Political Language

2015 ◽  
Vol 12 (2) ◽  
Author(s):  
Muhamad Isnaini ◽  
Busmin Gurning ◽  
Edy Setia
Keyword(s):  
Key Words ◽  
Group Identity ◽  
Political Language ◽  
Dominant Type ◽  
Illocutionary Acts ◽  
Politeness Strategies ◽  
The Subject ◽  
Positive Strategy ◽  
Distance Relationship ◽  
Negative Strategy

This study deals with politeness strategies in political language. The aim of the study is to describe how Indonesian politicians realize politeness in their language. The subject was taken nine parties who have representatives. They come from different parties: Democrat, Golkar, PDIP, PKS, PPP, PKB, PAN, Gerindra and Hanura. Data were classified and verified with reference to the criteria of politeness strategies as determined by Brown & Levinson (1987); cover the bald on record strategy, positive strategy, negative strategy and off-record strategy. The finding show that there were four types of politeness strategies used by Politicians in different of types of illocutionary acts; positive strategy, bald on record strategy, negative strategy, and off-record strategy. The most dominant type of politeness strategies used was positive strategy. The most dominant type was due to fact that speakers in interaction try to get closer the hearers. They use the group identity marker in addressing someone so there is no distance relationship between the speaker and hearer. They also gave the reasons when they speak in order to satisfy the hearer. Key words: politician; political language; politeness strategy

Direct Measurement of Charge Reversal on Lipid Bilayers using Heterodyne-Detected Second Harmonic Generation Spectroscopy

2019 ◽  
Author(s):  
HanByul Chang ◽  
Paul Ohno ◽  
Yangdongling Liu ◽  
Franz Geiger
Keyword(s):  
Lipid Bilayers ◽  
Surface Potential ◽  
Second Harmonic ◽  
Fluid Phase ◽  
Cationic Polyelectrolyte ◽  
Charge Reversal ◽  
Buried Interfaces ◽  
Phase Transition Temperatures ◽  
Complementary Techniques ◽  
Order Susceptibility

We report the detection of charge reversal induced by the adsorption of a cationic polyelectrolyte, poly(allylamine) hydrochloride (PAH), to buried supported lipid bilayers (SLBs), used as idealized model biological membranes. We observe changes in the surface potential in isolation from other contributors to the total SHG response by extracting the phase-shifted potential-dependent third-order susceptibility from the overall SHG signal. We demonstrate the utility of this technique in detecting both the sign of the surface potential and the point of charge reversal at buried interfaces without any prior information or complementary techniques<i>.</i>Furthermore, isolation of the second-order susceptibility contribution from the overall SHG response allows us to directly monitor changes in the Stern Layer. Finally, we characterize the Stern and Diffuse Layers over single-component SLBs formed from three different zwitterionic lipids of different gel-to-fluid phase transition temperatures (T<sub>m</sub>s). We determine whether the surface potential changes with the physical phase state (gel, transitioning, or fluid) of the SLB and incorporate 20 percent of negatively charged lipids to the zwitterionic SLB to investigate how the surface potential changes with surface charge.

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