Magnetic field is maintained stable by field frequency locking which is achieved by selecting substance with a powerful NMR signal and placed physically apart from the test sample (external lock) or dissolved within the test sample (internal lock). [2] 3. The Detector System The system consists of an appropriate electronic circuitry, a computer and peripheral devices to detect amplify and display the NMR signals. It is very sensitive and can sense the difference of frequency signs. The standard and test sample’s frequency can be differentiated by the detectors.
The hydrogen atom nuclei can change the direction of spin to the opposite direction. For the direction to change, a radio frequency is given off by the coil. The signal that is used when MRI images
The middle layer is a group of laser beams. And the inner layer is nanotubes that protect structures from laser beams. Later he argues the lasers will destroy objects, which the lasers will go that get through the force field. To fix that problem Kaku thinks that the force field needs to have photochromatics. Then Kaku states that force fields can do more than deflecting laser beams because it can levitate objects by the use of magnetic force fields.
1. Explain how medical magnetic resonance imaging (MRI) exploits the magnetic properties of the nucleus. MRI’s rotate the nucleus of an atom, producing a magnetic field. During a MRI, a person is placed between the poles of a strong magnet. The magnetic field permeates the tissue and causes the nucleus scale magnets in the tissues to rotate.
The optical time-domain reflectometer is the fiber-optic equivalent of the TDR. This tester transmits a calibrated signal pulse over the cable to be tested and monitors the signal that returns back to the unit. Unlike TDR however OTDR measures the signal returned by backscatter, phenomenon that affects all fiber-optic cable. Due to splicing and attaching connectors to fiber-optic cables the best way to inspect cleaved fiber ends and polished connection ferrules is with a microscope. The microscope is designed to hold cables and connectors in precisely the correct position for examination enabling you to detect dirty, scratched, or cracked connectors and ensure that cables are cleaved properly in preparation for splicing.
The amplitude (height of voltage spike) during depolarization remains constant as the action potential travels down the length of the axon. Measuring Changes in Membrane Potential Voltage changes in membrane potentials can be measured using patch clamp equipment. Patch clamp electrodes are placed at different positions along the neuron. Special lighting and microscopy is required to visualize non-stained neurons. Changes in the membrane potential can be observed by using a voltage-sensitive fluorescent dye.
Light travels in straight lines When an object is held between a point source of light and a screen, a shadow is formed. If a line is drawn (representing a light ray) joining the light source, the top of the object, and the top of the shadow, this line is straight. 3. Light can be reflected When light strikes a surface, it can bounces back off that surface, Practically every surface reflects some light – if not, we would not be able to see colors. 4.
6. Describe the way in which the above named industrial and medical radioisotopes are used and explain their use in terms of their chemical properties. Cobalt-60 is used in industrial radiography to inspect metal parts and welds for defects. Beams of radiation are directed at the object to be checked from a sealed source of Co-60. Radiographic film on the opposite side of the source is exposed when it is struck by radiation passing through the objects being tested.
Snell's law (also known as the Snell–Descartes law and the law of refraction) is a formula used to describe the relationship between the angles of incidence and refraction, when referring to light or other waves passing through a boundary between two different isotropic media, such as water, glass and air. In optics, the law is used in ray tracing to compute the angles of incidence or refraction, and in experimental optics and gemology to find the refractive index of a material. The law is also satisfied in metamaterials, which allow light to be bent "backward" at a negative angle of refraction with a negative refractive index. Snells Law Although named after Dutch astronomer Willebrord Snellius (1580–1626), the law was first accurately described by the scientist Ibn Sahlat Baghdad court, when in 984 he used the law to derive lens shapes that focus light with no geometric aberrations in the manuscript On Burning Mirrors and Lenses (984). [1][2] Snell's law states that the ratio of the sines of the angles of incidence and refraction is equivalent to the ratio of phase velocities in the two media, or equivalent to the reciprocal of the ratio of the indices of refraction: with each as the angle measured from the normal of the boundary, as the velocity of light in the respective medium (SI units are meters per second, or m/s) and as the refractive index (which is unitless) of the respective medium.
It operates by the passage of a light beam (a stream of photons) through a sample and the measurement of that light intensity by the spectrophotometer detector. When the photon is encountered by the analyte, there is the chance of photon absorption which reduces the light intensity that originally entered the solution (5). The λmax value yield by the solution absorbance spectrum provides information on the electronic structure of the analyte as the wavelength at λmax is characteristic to that solution. The Beer’s lambert Law relates the amount of light absorbed to the concentration of the solution absorbing the light as the linear relationship (2): A = A(1%1cm) x c x l Where A represents the Absorbance of the solution at λmax, A(1%1cm) is the Absorbance Coefficient (mg-1cm2) , c represents the Concentration (mg cm3) and l is the path length of