Collection Efficiency of the Nuclepore Membrane Filter for Aerosol Sampling and Its Application to218Po Measurement

1992 ◽  
Vol 31 (Part 1, No. 11) ◽  
pp. 3699-3700
Author(s):  
Kenji Fukami ◽  
Kiyoshi Shizuma ◽  
Kazuo Iwatani ◽  
Hiromi Hasai
Keyword(s):  
Collection Efficiency ◽  
Membrane Filter ◽  
Aerosol Sampling ◽  
Nuclepore Membrane

Suitability of membrane-filter techniques to study the ultrastructure of Fusarium solani in soil

1976 ◽  
Vol 22 (11) ◽  
pp. 1628-1633 ◽  
Author(s):  
W. H. Van Eck
Keyword(s):  
Fusarium Solani ◽  
Membrane Filter ◽  
Microscopical Examination ◽  
Improved Method ◽  
Selective Effect ◽  
Electron Microscopical Examination ◽  
Membrane Filters ◽  
Transmission Electron ◽  
Electron Microscopical ◽  
Nuclepore Membrane

The suitability of two types of membrane filters for scanning and transmission electron-microscopical examination of chlamydospores formed from macroconidia of Fusarium solani from soil was tested. An improved method to incubate propagules in soil and to collect them free from soil particles for electron-microscopical observations is described. Best results were obtained if macroconidia were incubated in soil between two Nuclepore membrane filters. Both chlamydospore morphology and lysis, however, were affected to some extent in comparison with that on single membranes. This is probably due to a selective effect on the microflora colonizing the chlamydospores.

Quantitative microanalysis of cristobalite by X-ray powder diffraction

1983 ◽  
Vol 16 (1) ◽  
pp. 21-23 ◽  
Author(s):  
E. Bye
Keyword(s):  
Detection Limit ◽  
Membrane Filter ◽  
Sample Holder ◽  
X Ray Diffraction ◽  
X Ray ◽  
Membrane Filters ◽  
Quantitative Microanalysis ◽  
Instrumental Drift ◽  
Nuclepore Membrane

A method for the quantitative X-ray diffraction analysis of microgram amounts of cristobalite is presented. Dust samples (1–2 mg) distributed on Nuclepore membrane filters are placed upon a silver membrane filter in a rotating sample holder. The diffraction pattern intensities of the silver filter are used to correct for absorption and for long-term instrumental drift. The detection limit is 10 μg with an accuracy of ± 10% at the 0.3 mg level.

Rapid membrane filtration epifluorescent microscopic technique for the direct enumeration of somatic cells in fresh and formalin-preserved milk

1981 ◽  
Vol 48 (2) ◽  
pp. 239-246 ◽  
Author(s):  
Graham L. Pettipher ◽  
Ubaldina M. Rodrigues
Keyword(s):  
Heat Treatment ◽  
Membrane Filtration ◽  
Membrane Filter ◽  
Somatic Cells ◽  
Raw Milk ◽  
Secretory Cells ◽  
Polymorphonuclear Leucocytes ◽  
Microscopic Technique ◽  
Different Types ◽  
Nuclepore Membrane

SummaryA rapid method for the direct enumeration of somatic cells in fresh and formalin-preserved raw milk is described. Heat treatment at 80°C for 10 mn fixed somatic cells sufficiently to prevent lysis and subsequent dilution allowed the equivalent of at least 0.5 ml milk to be filtered through a 1.0 μm pore size Nuclepore membrane filter. The somatic cells were concentrated on the membrane and, after staining with acridine orange, fluoresced green, yellow or orange under an epifluorescent microscope. Three different types of cell could be distinguished on the basis of nuclear structure and cell size. These were monocytes, polymorphonuclear leucocytes and the larger epithelial and/or secretory cells. For both fresh and preserved milks the count of somatic cells on the membrane correlated well (r≽ 0·93) with the Coulter count. Differences between counts obtained by different operators were not significant. The technique is rapid, taking about 20min, and is suitable for milks containing between 2 × 104and 1 × 107somatic cells/ml.

Diffusive collection of aerosol particles on Nuclepore membrane filter

1976 ◽  
Vol 10 (3) ◽  
pp. 274-277 ◽  
Author(s):  
Terence N. Smith ◽  
Colin R. Phillips ◽  
Octavio T. Melo
Keyword(s):  
Membrane Filter ◽  
Aerosol Particles ◽  
Nuclepore Membrane

Collection efficiency of aerosol sampling instruments

1994 ◽  
Vol 25 (7) ◽  
pp. 1359
Author(s):  
O. Witschger ◽  
J.F. Fabries ◽  
P. Görner ◽  
A. Renoux
Keyword(s):  
Collection Efficiency ◽  
Aerosol Sampling

To What Extent are Inelastically Scattered Electrons Useful in the Stem?

1973 ◽  
Vol 31 ◽  
pp. 286-287 ◽  
Author(s):  
H. Rose
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Electron Correlation ◽  
Quantum Noise ◽  
Collection Efficiency ◽  
Scanning Transmission Electron Microscope ◽  
Electron Cloud ◽  
Scanning Time ◽  
Transmission Electron ◽  
Scanning Transmission

The scanning transmission electron microscope offers the possibility of utilizing inelastically scattered electrons. Use of these electrons in addition to the elastically scattered electrons should reduce the scanning time (dose) Which is necessary to keep the quantum noise below a certain level. Hence it should lower the radiation damage. For high resolution, Where the collection efficiency of elastically scattered electrons is small, the use of Inelastically scattered electrons should become more and more favorable because they can all be detected by means of a spectrometer. Unfortunately, the Inelastic scattering Is a non-localized interaction due to the electron-electron correlation, occurring predominantly at the circumference of the atomic electron cloud.

High energy resolution spectrometer for the dedicated STEM

1984 ◽  
Vol 42 ◽  
pp. 558-559 ◽  
Author(s):  
P.E. Batson
Keyword(s):  
Collection Efficiency ◽  
Core Loss ◽  
Beam Current ◽  
High Energy ◽  
High Energy Resolution ◽  
Acquisition Time ◽  
Good Definition ◽  
Loss Analysis ◽  
Definition Of ◽  
Acceleration Voltage

Use of the STEM to obtain precise electronic information has been hampered by the lack of energy loss analysis capable of a resolution and accuracy comparable to the 0.3eV energy width of the Field Emission Source. Recent work by Park, et. al. and earlier by Crewe, et. al. have promised magnetic sector devices that are capable of about 0.75eV resolution at collection angles (about 15mR) which are great enough to allow efficient use of the STEM probe current. These devices are also capable of 0.3eV resolution at smaller collection angles (4-5mR). The problem that arises, however, lies in the fact that, even with the collection efficiency approaching 1.0, several minutes of collection time are necessary for a good definition of a typical core loss or electronic transition. This is a result of the relatively small total beam current (1-10nA) that is available in the dedicated STEM. During this acquisition time, the STEM acceleration voltage may fluctuate by as much as 0.5-1.0V.

High spatial resolution x-ray microanalysis of interfaces

1995 ◽  
Vol 53 ◽  
pp. 284-285
Author(s):  
J. R. Michael
Keyword(s):  
Spatial Resolution ◽  
Electron Probe ◽  
Solid Angle ◽  
Collection Efficiency ◽  
Spatial Scales ◽  
Energy Dispersive Spectrometer ◽  
X Rays ◽  
X Ray ◽  
Probe Size ◽  
Brightness Field

X-ray microanalysis in the analytical electron microscope (AEM) refers to a technique by which chemical composition can be determined on spatial scales of less than 10 nm. There are many factors that influence the quality of x-ray microanalysis. The minimum probe size with sufficient current for microanalysis that can be generated determines the ultimate spatial resolution of each individual microanalysis. However, it is also necessary to collect efficiently the x-rays generated. Modern high brightness field emission gun equipped AEMs can now generate probes that are less than 1 nm in diameter with high probe currents. Improving the x-ray collection solid angle of the solid state energy dispersive spectrometer (EDS) results in more efficient collection of x-ray generated by the interaction of the electron probe with the specimen, thus reducing the minimum detectability limit. The combination of decreased interaction volume due to smaller electron probe size and the increased collection efficiency due to larger solid angle of x-ray collection should enhance our ability to study interfacial segregation.

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