Virtual image

Image, virtual n. This image would appear by construction to be in a given plane, but... 

Technology that uses X-rays to produce images (virtual slices), allowing to see inside the body. Equipment in which charged particles, after acceleration in a circular pathway, are directed onto a target for evoking a nuclear reaction. Spontaneous reaction of a radionuclide to form another (radio)nuclide accompanied by the release of ionising radiation. 

Additional assistance is provided by secondary modification options that allow among others for a depiction of the original signal, the reconstruction of the depiction of the impedance plane of the eddy-current signals or for modifications of phase, amplification or zero point virtually in real time. That way, once C-scan images have been recorded, they can now be evaluated as needed without having to repeat the test. 

Imaging plates are exposed similar to radiographic films. They are read out by a LASER-scanner to a digital image without any developing process. After optical erasing of the virtual picture the same IP can be used cyclic up to more than 1000 times. The life time is limited by the mechanical stability of the IP s. An IP consists of a flexible polymer carrier which is coated with the sensitive layer. This layer is covered with a thin transparent protective foil. 

The projection model (equations 1, 2) describes the mapping of 3D points = m,yw,2wY to 2D image points Pi = (ii,j/i) in a virtual, undistorted image plane. The... 

The distortion model (equations 3) describes the mapping of virtual, undistorted image points Pi = xi,yiY to distorted image points P = (i , y Y the real image using third order (2-dimensional) polynomals. 

The real image is seen by the eye as a virtual image at 25 cm distance, the nomial distance for distinct vision. 

The magnification achievable by a microscope is the ratio of the scales of the virtual image and of... 

Choose the nonbonded cutoff carefully when using periodic boundary conditions. The cutoff must be small enough to prevent an atom from interacting simultaneously with another atom and with that atom s virtual image. 

The second term represents a virtual image of the original object signal which can be viewed by an observer looking at the hologram along the original... 

Fig. 3. Holographic reconstmction. (a) Reconstmction of virtual image of object (b) reconstmction of real image of object.

Various ion-optical tricks have to be used to compensate for the spread of energies of the extracted ions, which limit mass resolution unless corrected for. In the latest version of the atom probe (Cerezo et at. 1988), spatial as well as compositional information is gathered. The hole in the imaging screen is dispensed with and it is replaced by a position-sensitive screen that measures at each point on the screen the time of flight, and thus a compositional map with extremely high (virtually atomic) resolution is attained. Extremely sophisticated computer control is needed to obtain valid results. 

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