scholarly journals Development of a Piezo-driven Mechanical Stage Integrated Microdisplacement Sensor for Calibration of Displacements

2014 ◽  
pp. 547
Keyword(s):  
Author(s):  
Neil Rowlands ◽  
Jeff Price ◽  
Michael Kersker ◽  
Seichi Suzuki ◽  
Steve Young ◽  
...  

Three-dimensional (3D) microstructure visualization on the electron microscope requires that the sample be tilted to different positions to collect a series of projections. This tilting should be performed rapidly for on-line stereo viewing and precisely for off-line tomographic reconstruction. Usually a projection series is collected using mechanical stage tilt alone. The stereo pairs must be viewed off-line and the 60 to 120 tomographic projections must be aligned with fiduciary markers or digital correlation methods. The delay in viewing stereo pairs and the alignment problems in tomographic reconstruction could be eliminated or improved by tilting the beam if such tilt could be accomplished without image translation.A microscope capable of beam tilt with simultaneous image shift to eliminate tilt-induced translation has been investigated for 3D imaging of thick (1 μm) biologic specimens. By tilting the beam above and through the specimen and bringing it back below the specimen, a brightfield image with a projection angle corresponding to the beam tilt angle can be recorded (Fig. 1a).


1991 ◽  
Vol 24 (7) ◽  
pp. 103-111 ◽  
Author(s):  
G. Brattberg ◽  
L.-G. Reinius ◽  
M. Tendaj

Stockholm was founded at the point where the waters of Lake Mälaren emerge into the Baltic Sea. Lake Mälaren is the water source of the water works of Stockholm. The Lake also receives water from one of the sewage treatment plants. The outlet from the two other sewage treatment plants are in the inner part of the archipelago. During 1968-73 the treatment was improved, after which the phosphorus load to the receiving water significantly decreased. The total P concentration in the surface water has decreased since 1970 and phosphorus has replaced nitrogen as the most limiting nutrient throughout the entire archipelago within 50 km from Stockholm. To further reduce the eutrophication a continued reduction of the phosphorus load is most effective. For the Baltic proper as a whole, where primary nitrogen limitation is present, it is important to reduce the supply of nitrogen to the greatest possible extent. The treatment plants in Stockholm are located in subsurface rock-chambers. The treatment includes mechanical, biological and chemical treatment. In the mechanical stage the sewage is treated in screens, grit chambers and primary sedimentation. The biological stage is a conventional activated sludgeprocess. For the chemical precipitation ferroussulphateis added before the screens. The sludge is stabilized in anaerobic digesters and dewatered in centrifuges before disposal on farmland. To meet more stringent requirements on nitrification and nitrogen removal several projects are going on to optimize the nutrient removal. The aim of these investigations is to improve the plants' performance within the existing plant.


2006 ◽  
Vol 946 ◽  
Author(s):  
Malik Idries Adam ◽  
Kozo Osamura

ABSTRACTTensile strain dependence of electromechanical characteristics of high-current, (Hic) and high-strength, (Hs) type Ag/Bi2223 composite tapes measured at room temperature, RT and 77K is investigated. Mechanical strength of composites revealed strain-hardening signature in Bi2223 filaments due to plastic strain above the elastic limit. Critical current, Ic maintained constant value up to the elastic limit then decreased slowly before finally dropped to about 10% at 0.19% and 0.39% strain, signaling a three-stage limitation. Microstructure observations and electromechanical response of the composites suggest that a limited longitudinal, transverse, interfacial, granular and transgranular microcracks formed during gradual imposition of strain hardening in Bi2223 filaments may be responsible for the slow reduction of Ic in the medium mechanical stage.


This paper resumes our study of the reversing spiral structure found in the cell wall of cotton hairs, and presents typical samples of the many thousands of measurements which we have made during the past three years in an attempt to interpret their significance by statistical methods. These measurements were made under the microscope by the use of elliptically polarized light, with eye-piece graticules and mechanical stage, the colour change being checked by direct observation of the structure whenever any doubt existed. It is not advisable to draw rigid conclusions as to the causation of the spiral reversals from the data here presented, because such conclusions would be pure inference, unsupported by direct observation. We have tried to grow cotton hairs in vitro , outside the boll, for such observation, but have failed so far. The data are therefore given as a record of facts, with no more speculation as to their meaning than is needed to make them cohere. We feel sure that their significance transcends the limits of the genus Gossypium , and that statistical study of the data, such as is beyond our competence, would give much information about the detailed mechanism of one part of the growth process.


1968 ◽  
Vol 31 (11) ◽  
pp. 350-354 ◽  
Author(s):  

The Direct Microscopic Somatic Cell Count is a modification of the Breed technique in which 0.01 ml of milk sample is spread over a circular 1 cm2 area on a special slide, and is dried, stained, and examined microscopically using the oil-immersion lens. The unit of area examined is a diametric strip of the milk film, traversed by manipulation of the mechanical stage controls. A special eyepiece reticle defines the width of the strip. All nucleated somatic cells within the strip are counted. The estimate of cellular concentration in the milk sample is based on the count of two mutually perpendicular strips on each of duplicate films. The method permits both determination and close control of count precision.


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