Search results
Results from the WOW.Com Content Network
A contrast effect is the enhancement or diminishment, relative to normal, of perception, cognition or related performance as a result of successive (immediately previous) or simultaneous exposure to a stimulus of lesser or greater value in the same dimension. (Here, normal perception, cognition or performance is that which would be obtained in ...
An easy way to estimate a first-degree polynomial model is to use a factorial experiment or a fractional factorial design.This is sufficient to determine which explanatory variables affect the response variable(s) of interest.
[6] [7] English for Academic Purposes (EAP) classes teach other types of writing besides the student essay required in college classes. [8] [9] Other important genres are the academic research article, research report, and grant proposal. Writing for professional purposes, such as business, is also now considered a legitimate type of second ...
A contrast is defined as the sum of each group mean multiplied by a coefficient for each group (i.e., a signed number, c j). [10] In equation form, = ¯ + ¯ + + ¯ ¯, where L is the weighted sum of group means, the c j coefficients represent the assigned weights of the means (these must sum to 0 for orthogonal contrasts), and ¯ j represents the group means. [8]
The decadic absorbance of a scattering sample is defined as −log 10 (R+T) or −log 10 (1−A). For a non scattering sample, R = 0, and the expression becomes −log 10 T or log( 1 / T ), which is more familiar. In a non-scattering sample, the absorbance has the property that the numerical value is proportional to sample thickness.
Allergic reactions are rare. [1] The use of barium during pregnancy is safe for the baby; however, X-rays may result in harm. [4] Barium sulfate suspension is typically made by mixing barium sulfate powder with water. [1] It is a non-iodinated contrast media. [5] Barium sulfate has been known since the Middle Ages. [6]
Gadopentetic acid, sold under the brand name Magnevist, is a gadolinium-based MRI contrast agent. [2]It is usually administered as a salt of a complex of gadolinium with DTPA (diethylenetriaminepentacetate) with the chemical formula A 2 [Gd(DTPA)(H 2 O)]; when cation A is the protonated form of the amino sugar meglumine the salt goes under the name "gadopentetate dimeglumine".
Images are produced using contrast medium by subtracting a "pre-contrast image" or mask from subsequent images, once the contrast medium has been introduced into a structure. Hence the term "digital subtraction angiography. [1] [2] Subtraction angiography was first described in 1935 and in English sources in 1962 as a manual technique. Digital ...