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The complications of SEMS are related to a number of factors. The first is that the endoscopic procedure used to insert a SEMS involves the use of sedative medications, which may lead to oversedation, aspiration, or drug reaction. SEMS also expand and can lead to perforation of the bowel or compression of structures adjacent to the bowel. [18]
This has been demonstrated on the commercial ESEMs that provide the finest beam spots by imaging test specimens, i.e. customarily gold particles on a carbon substrate, in both vacuum and gas. However, the contrast decreases accordingly as the electron probe loses current with travel distance and increase of pressure. The loss of current ...
An account of the early history of scanning electron microscopy has been presented by McMullan. [2] [3] Although Max Knoll produced a photo with a 50 mm object-field-width showing channeling contrast by the use of an electron beam scanner, [4] it was Manfred von Ardenne who in 1937 invented [5] a microscope with high resolution by scanning a very small raster with a demagnified and finely ...
In the 80386, two test registers, TR6 and TR7, were provided for the purpose of TLB testing. TR6 was the test command register, and TR7 was the test data register. The 80486 provided three additional registers, TR3, TR4 and TR5, for testing of the L1 cache. TR3 was a data register, TR4 was an address register and TR5 was a command register.
There are several small SMES units available for commercial use and several larger test bed projects. Several 1 MW·h units are used for power quality control in installations around the world, especially to provide power quality at manufacturing plants requiring ultra-clean power, such as microchip fabrication facilities.
Most widespread instruments are using liquid metal ion sources (LMIS), especially gallium ion sources. Ion sources based on elemental gold and iridium are also available. In a gallium LMIS, gallium metal is placed in contact with a tungsten needle, and heated gallium wets the tungsten and flows to the tip of the needle, where the opposing forces of surface tension and electric field form the ...
To provide the boundary scan capability, IC vendors add additional logic to each of their devices, including scan cells for each of the external traces. These cells are then connected together to form the external boundary scan shift register (BSR), and combined with JTAG Test Access Port (TAP) controller support comprising four (or sometimes more) additional pins plus control circuitry.
In power stations affected by the Acid Rain Program, annual (or bi-annual) certification of the system must be performed by an independent firm. The firm will have an independent CEM system temporarily in place to collect emissions data in parallel with the plant CEMS. This testing is referred to as a Relative Accuracy Test Audit (RATA).