scholarly journals Depth Distribution of Suspended Matter in the Sand Layer of Slow Sand Filters in Winter.

1997 ◽  
Vol 33 (3) ◽  
pp. 109-116
Author(s):  
MASUO YAMAMOTO ◽  
NOBUTADA NAKAMOTO
Keyword(s):  
Suspended Matter ◽  
Depth Distribution ◽  
Sand Layer ◽  
Sand Filters

Protection layers for the extension of slow sand filter running times in wastewater reuse

2002 ◽  
Vol 2 (1) ◽  
pp. 305-309
Author(s):  
H.-J. Mälzer ◽  
R. Gimbel
Keyword(s):  
Pressure Drop ◽  
Suspended Solids ◽  
Wastewater Reuse ◽  
Sand Layer ◽  
Sand Filters ◽  
Sand Filter ◽  
Running Time ◽  
Slow Sand Filter ◽  
Surface Filtration

The running time of slow sand filters in wastewater reuse is limited by the increase of pressure drop which is mainly caused by the surface filtration of suspended solids. Surface filtration mechanisms on the top of filter sand layer can be avoided e.g. by protection layers. Choosing suitable materials for protection layers a considerable extension of slow sand filter running times can be achieved.

Protection layers for the extension of slow sand filter running times in wastewater reuse

2006 ◽  
Vol 6 (1) ◽  
pp. 105-111 ◽  
Author(s):  
H.-J. Mälzer ◽  
R. Gimbel
Keyword(s):  
Pressure Drop ◽  
Suspended Solids ◽  
Wastewater Reuse ◽  
Sand Layer ◽  
Sand Filters ◽  
Sand Filter ◽  
Running Time ◽  
Slow Sand Filter ◽  
Surface Filtration

The running time of slow sand filters in wastewater reuse is usually limited by the increase of pressure drop which is mainly caused by surface filtration effects of suspended solids. Surface filtration mechanisms on the top of filter sand layer can be avoided e.g. by so-called protection layers. By choosing suitable materials for protection layers a considerable extension of slow sand filter running times can be achieved.

Applications of SIMS to electronic materials and devices

1992 ◽  
Vol 50 (2) ◽  
pp. 1682-1683
Author(s):  
S.F. Corcoran
Keyword(s):  
Depth Distribution ◽  
Secondary Ion Mass Spectrometry ◽  
Semiconductor Device ◽  
Electronic Materials ◽  
Profile Analysis ◽  
Semiconductor Industry ◽  
Small Diameter ◽  
Depth Resolution ◽  
Detection Sensitivity

Over the past decade secondary ion mass spectrometry (SIMS) has played an increasingly important role in the characterization of electronic materials and devices. The ability of SIMS to provide part per million detection sensitivity for most elements while maintaining excellent depth resolution has made this technique indispensable in the semiconductor industry. Today SIMS is used extensively in the characterization of dopant profiles, thin film analysis, and trace analysis in bulk materials. The SIMS technique also lends itself to 2-D and 3-D imaging via either the use of stigmatic ion optics or small diameter primary beams.By far the most common application of SIMS is the determination of the depth distribution of dopants (B, As, P) intentionally introduced into semiconductor materials via ion implantation or epitaxial growth. Such measurements are critical since the dopant concentration and depth distribution can seriously affect the performance of a semiconductor device. In a typical depth profile analysis, keV ion sputtering is used to remove successive layers the sample.

Fluorescence effects in quantitative microprobe analysis

1990 ◽  
Vol 48 (2) ◽  
pp. 188-189
Author(s):  
S.J.B. Reed
Keyword(s):  
Microprobe Analysis ◽  
Depth Distribution ◽  
Exciting Radiation ◽  
Primary Radiation ◽  
List Type ◽  
Type Number ◽  
Computing Power ◽  
X Ray ◽  
Fluorescent Radiation

Characteristic fluorescenceThe theory of characteristic fluorescence corrections was first developed by Castaing. The same approach, with an improved expression for the relative primary x-ray intensities of the exciting and excited elements, was used by Reed, who also introduced some simplifications, which may be summarized as follows (with reference to K-K fluorescence, i.e. K radiation of element ‘B’ exciting K radiation of ‘A’):1.The exciting radiation is assumed to be monochromatic, consisting of the Kα line only (neglecting the Kβ line).2.Various parameters are lumped together in a single tabulated function J(A), which is assumed to be independent of B.3.For calculating the absorption of the emerging fluorescent radiation, the depth distribution of the primary radiation B is represented by a simple exponential.These approximations may no longer be justifiable given the much greater computing power now available. For example, the contribution of the Kβ line can easily be calculated separately.

A New Numerical Model for Electron-Probe Analysis at High Depth Resolution

1996 ◽  
Vol 54 ◽  
pp. 490-491
Author(s):  
P.-F. Staub ◽  
C. Bonnelle ◽  
F. Vergand ◽  
P. Jonnard
Keyword(s):  
Electron Probe ◽  
Surface Segregation ◽  
Depth Distribution ◽  
Computing Time ◽  
Depth Resolution ◽  
Physical Parameters ◽  
Electron Probe Analysis ◽  
Interface Phases ◽  
Excitation Conditions ◽  
High Depth

Characterizing dimensionally and chemically nanometric structures such as surface segregation or interface phases can be performed efficiently using electron probe (EP) techniques at very low excitation conditions, i.e. using small incident energies (0.5<E0<5 keV) and low incident overvoltages (1<U0<1.7). In such extreme conditions, classical analytical EP models are generally pushed to their validity limits in terms of accuracy and physical consistency, and Monte-Carlo simulations are not convenient solutions as routine tools, because of their cost in computing time. In this context, we have developed an intermediate procedure, called IntriX, in which the ionization depth distributions Φ(ρz) are numerically reconstructed by integration of basic macroscopic physical parameters describing the electron beam/matter interaction, all of them being available under pre-established analytical forms. IntriX’s procedure consists in dividing the ionization depth distribution into three separate contributions:

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