scholarly journals ELECTROKINETIC PHENOMENA. II

1930 ◽  
Vol 13 (6) ◽  
pp. 657-668 ◽  
Author(s):  
Harold A. Abramson
Keyword(s):  
Glass Surface ◽  
Flat Surface ◽  
Electric Mobility ◽  
Electrokinetic Phenomena ◽  
Size And Shape ◽  
Round Surface

Two theories which predict different values for the ratio of VE, the electroendosmotic velocity of a liquid past a surface, to Vp, the electric mobility of a particle of the same surface through the same liquid are discussed. The theory demanding that See PDF for Equation was supported by certain data of van der Grinten for a glass surface. Re-calculation of van der Grinten's data reveals that the ratio varies between 2.1 and 2.8. These results are in accord with previous data of Abramson. It is pointed out that glass is unsuitable for the investigation. The ratio See PDF for Equation is here determined for a flat surface and particles when both are covered by the same proteins. Under these conditions See PDF for Equation The theory is similarly tested for a round surface using a micro-cataphoresis cell. It is shown that See PDF for Equation for a round surface is approximately 1.00. These findings are confirmatory of previous data supporting the view that cataphoretic mobility is independent of the size and shape of the particles when all particles compared have similar surface constitutions.

Single Phase Pressure-Drop Tests in 7-Element Bundles With Different Endplug Shapes

2008 ◽  
Author(s):  
S. K. Yang
Keyword(s):  
Pressure Drop ◽  
Single Phase ◽  
Flat Surface ◽  
Reactor Core ◽  
Drop Tests ◽  
Round Surface ◽  
The Difference ◽  
Phase Pressure

Pressure-drop characteristics in CANDU® fuel bundles are of importance for critical power analysis and safety trip analysis for the reactor core. Different kinds of endplug shapes are being used in different fuel designs. The difference in endplug shape may result in slightly different hydraulic characteristics of the fuel bundles. Single-phase pressure-drop tests were performed in aligned and misaligned (15° and 30°) 7-element bundle strings with three different endplug shapes (Type 1, 2 and 3): Type 1 and 3 with round surface, and Type 2 with flat surface. The test results showed that the bundle-loss coefficients of the misaligned bundle with Type 2 having flat surface presented the highest value among the three-endplug types: 8.6% higher on average, compared to those of the misaligned bundle with Type 1 endplugs (Type 1 as a reference).

scholarly journals Measuremets of sootblower jet strength in kraft recovery boilers - Part II: Results of the third and fourth field trials

TAPPI Journal ◽  
2012 ◽  
Vol 11 (9) ◽  
pp. 31-35 ◽  
Author(s):  
HONGHI TRAN ◽  
AMEYA POPHALI ◽  
MARKUS BUSSMANN ◽  
PASI MIIKKULAINEN
Keyword(s):  
Field Trial ◽  
Flat Surface ◽  
Force Measurement ◽  
Field Trials ◽  
Size And Shape ◽  
The Third ◽  
Kraft Recovery Boilers ◽  
Recovery Boilers ◽  
Original Strength ◽  
Inclined Surface

Two additional field trial studies were conducted in different kraft recovery boilers in Sweden using force-measurement probes to determine the force of sootblower jets under various blowing conditions. The results confirm the findings of previous trials that, at a given distance, the force exerted on a target by a fully expanded sootblower jet increases nearly linearly with an increase in lance pressure. At a given lance pressure, the jet force decreases drastically as the distance between the sootblower nozzle and the target increases. At a distance farther than 1 m from the nozzle, the jet retains less than 10% of its original strength. The studies also show clearly that the size and shape of the target have a significant effect on the force exerted on it by the jet. A flat surface receives a greater force from the jet than a target with an inclined surface.

scholarly journals ELECTROKINETIC PHENOMENA

1933 ◽  
Vol 16 (4) ◽  
pp. 593-603 ◽  
Author(s):  
Harold A. Abramson
Keyword(s):  
Hydrochloric Acid ◽  
Double Layer ◽  
Electric Double Layer ◽  
Alkali Halides ◽  
Hydrogen Ion ◽  
Electric Mobility ◽  
Simple Relationship ◽  
Electrokinetic Phenomena ◽  
Egg Albumin ◽  
Ion Activity

By assuming that the electric charge of proteins is primarily determined by the hydrogen ion activity of the medium, and by making corrections when necessary for the effect of salt, it is possible to derive a simple relationship between the electric mobility of proteins and the effective reciprocal thickness of the electric double layer. The decrease in electric mobility of proteins in solutions is readily predicted for gelatin in acetate buffers and for egg albumin in the presence of the alkali halides, of acetate buffers, and of hydrochloric acid on the basis of the assumptions made.

Unbiased estimation of particle number and sizes using the new stereological tools: the disector, the fractionator, the selector, and the nucleator — or just point-sampled intercepts

1988 ◽  
Vol 46 ◽  
pp. 428-429
Author(s):  
H.J.G. Gundersen
Keyword(s):  
Particle Number ◽  
Small Distance ◽  
Parallel Plane ◽  
Unbiased Estimation ◽  
Severe Problem ◽  
New Era ◽  
Size And Shape ◽  
Distinct Property ◽  
Sectioned Tissue

Previously, all stereological estimation of particle number and sizes were based on models and notoriously gave biased results, were very inefficient to use and difficult to justify. For all references to old methods and a direct comparison with unbiased methods see recent reviews.The publication in 1984 of the DISECTOR, the first unbiased stereological probe for sampling and counting 3—D objects irrespective of their size and shape, signalled the new era in stereology — and give rise to a number of remarkably simple and efficient techniques based on its distinct property: It is the only known way to obtain an unbiased sample of 3-D objects (cells, organelles, etc). The principle is simple: within a 2-D unbiased frame count or sample only cells which are not hit by a parallel plane at a known, small distance h.The area of the frame and h must be known, which might sometimes in itself be a problem, albeit usually a small one. A more severe problem may arise because these constants are known at the scale of the fixed, embedded and sectioned tissue which is often shrunken considerably.

Scanned tip measurement of deep vertical facets on a flat surface: Measuring roughness on gaas laser waveguide mirrors

1993 ◽  
Vol 51 ◽  
pp. 532-533
Author(s):  
Chang Shen ◽  
Phil Fraundorf ◽  
Robert W. Harrick
Keyword(s):  
Integrated Circuits ◽  
Flat Surface ◽  
Scanning Force Microscopy ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Force Microscopy ◽  
Optoelectronic Integrated Circuits ◽  
Laser Waveguide ◽  
Scanning Force ◽  
Gaas Laser

Monolithic integration of optoelectronic integrated circuits (OEIC) requires high quantity etched laser facets which prevent the developing of more-highly-integrated OEIC's. The causes of facet roughness are not well understood, and improvement of facet quality is hampered by the difficulty in measuring the surface roughness. There are several approaches to examining facet roughness qualitatively, such as scanning force microscopy (SFM), scanning tunneling microscopy (STM) and scanning electron microscopy (SEM). The challenge here is to allow more straightforward monitoring of deep vertical etched facets, without the need to cleave out test samples. In this presentation, we show air based STM and SFM images of vertical dry-etched laser facets, and discuss the image acquisition and roughness measurement processes. Our technique does not require precision cleaving. We use a traditional tip instead of the T shape tip used elsewhere to preventing “shower curtain” profiling of the sidewall. We tilt the sample about 30 to 50 degrees to avoid the curtain effect.

The influence of confocal microscope design on imaging performance

1993 ◽  
Vol 51 ◽  
pp. 144-145
Author(s):  
C J R Sheppard
Keyword(s):  
Image Quality ◽  
Fluorescence Imaging ◽  
Confocal Microscope ◽  
Industrial Applications ◽  
Three Dimensions ◽  
Design Parameters ◽  
Weak Signals ◽  
Size And Shape ◽  
Imaging Performance ◽  
Fundamental Limitation

The confocal microscope is now widely used in both biomedical and industrial applications for imaging, in three dimensions, objects with appreciable depth. There are now a range of different microscopes on the market, which have adopted a variety of different designs. The aim of this paper is to explore the effects on imaging performance of design parameters including the method of scanning, the type of detector, and the size and shape of the confocal aperture.It is becoming apparent that there is no such thing as an ideal confocal microscope: all systems have limitations and the best compromise depends on what the microscope is used for and how it is used. The most important compromise at present is between image quality and speed of scanning, which is particularly apparent when imaging with very weak signals. If great speed is not of importance, then the fundamental limitation for fluorescence imaging is the detection of sufficient numbers of photons before the fluorochrome bleaches.

Calculation of many-beam dynamic electron diffraction without high-energy approximation

1996 ◽  
Vol 54 ◽  
pp. 128-129
Author(s):  
B. R. Ahn ◽  
N. J. Kim
Keyword(s):  
Electron Diffraction ◽  
Flat Surface ◽  
Dynamic Theory ◽  
High Energy ◽  
Perfect Crystal ◽  
Zone Axis ◽  
Beam Dynamic ◽  
Diffraction Angle ◽  
Energy Approximation ◽  
The Many

High energy approximation in dynamic theory of electron diffraction involves some intrinsic problems. First, the loss of theoretical strictness makes it difficult to comprehend the phenomena of electron diffraction. Secondly, it is difficult to believe that the approximation is reasonable especially in the following cases: 1) when accelerating voltage is not sufficiently high, 2) when the specimen is thick, 3) when the angle between the surface normal of the specimen and zone axis is large, and 4) when diffracted beam with large diffraction angle is included in the calculation. However, until now the method to calculate the many beam dynamic electron diffraction without the high energy approximation has not been proposed. For this reason, the authors propose a method to eliminate the high energy approximation in the calculation of many beam dynamic electron diffraction. In this method, a perfect crystal with flat surface was assumed. The method was applied to the calculation of [111] zone axis CBED patterns of Si.

SIZE AND SHAPE OF CRYSTAL FACES ON HEATED METAL TIPS

1984 ◽  
Vol 45 (C9) ◽  
pp. C9-29-C9-37
Author(s):  
Vu Thien Binh ◽  
M. Drechsler
Keyword(s):  
Size And Shape ◽  
Heated Metal
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