Anisotropy

Measurements of diffusivity include fractional anisotropy and radial diffusivity. Fractional anisotropy (FA) and radial diffusivity (RD) are measurements of directionality of diffusion. A FA value of 0 represents unrestricted diffusion in all directions (isotropic) while a value of 1 represents diffusion along only one axis

When you turn on your old analog TV get that fuzzy black-and-white static, about one percent of the screen is filled with signal left over from the Big Bang. In 1964, Robert Wilson and Arno Penzias, two scientists working for Bell Labs, were using a radio antenna to search for microwaves emitted by the Milky Way. To their surprise, they discovered a faint signal that continued to show up in their readings, no matter which direction they pointed the radio telescope. Once they considered all of the

Solidification is essentially an atom movement process in diffusion controlled solidification. Take single-phase alloy for example, the alloy is in a composition of C0. The phase diagram (Fig. 2.9) of the alloy has been perfected by assuming solid line and liquid line are straight. Thus, the partition coefficient k can be given (Porter, Easterling and Sherif, 2009), k=C_S/C_L (2.13) and the volume fraction of the solid can be given, f_s=(C_L 〖-C〗_0)/(C_L

OBJECTIVE: To familiarize oneself of the processes associated with the deep drawing of thin sheet metals to analyse the factors that influence its behavior. Through this experiment, the differences of the material properties associated with different rolling directions will be considered and applied to the deformation of the cup when formed through deep drawing. THEORY: Please refer to P5: Plastic Properties of Sheet Metal lab manual for detailed Theory. [1] PROCEDURE: Sheet metal disks, one with

Cold deformation process of metals causes distortion of crystalline structure. When a material is formed, the grains are usually distorted and elongated in one or more directions which make the material anisotropic. Anisotropy can be defined as a difference in a material's physical or mechanical properties in different directions of taking of testing samples. In exploitation, it is very important to recognize the direction of grain elongation so that the best orientation of working part can be chosen

source for the instability is provided by excessive electron temperature anisotropy, because of the fact that unstable modes operate in low frequency range, the protons respond to the instability excitation as well. Kinetic instabilities driven by electron and proton temperature anisotropies, of which the present electron firehose instability is a part, are known to play significant roles in regulating the temperature anisotropy upper bound as the solar wind expands out into the interplanetary space

Rouw, Scholte and Colizoli (2011) compared seven different studies that explored anatomical differences using a measurement called fractional anisotropy (FA) which is a scaled ratio of the propensity of water to diffuse along axon bundles versus across them or perpendicularly (Whitaker et al., 2014). Their data found support for cross activation theory because of an increase of grey matter in area

8) As we know in UV spectroscopy the sample is between the source and the detector. So the light starts from the source and goes through the sample and ends in the detector. On the other hand in fluorescence spectroscopy the light is imparted at all angle as a result the detector misses a lot of light. This is a reason that fluorescence spectroscopy is more sensitive that UV spectroscopy. 9) As previously mentioned after absorbing energy an electron can jump from the ground state (lowest energy)

These calculations can offer understanding information into pathologic processes and microstructural abnormalities during fetal development (Qiu, Mori, & Miller, 2015). The qualitative parameters of mean diffusivity and fractional anisotropy are not dependent on patient head position (Limperopoulos & Clouchoux, 2009), which making them useful when imaging a fetus in multiple orientations. Directional information consistent to white matter fiber tract orientation within collimated bundles

This research article was published in the journal of Alzheimer’s disease and Parkinsonism on August 26th 2013, volume 3, issue 2. Dr.Perea et al. conducted the study at department of neurology, Alzheimer’s Research Disease Center, department of Psychology, Bioengineering program-department of engineering, at University of Kansas School of Medicine, Kansas City, KS, USA. The big question of this study is to investigate white matter differences to give better understanding of neurodegenerative