1.Please explain how medical magnetic resonance imaging (MRI) exploits the magnetic properties of the nucleus.
MRI exploits the process known as nuclear magnetic resonance (NMR). In fact the technique used to be called simply NMR or NMR imaging, but the “nuclear” was dropped because of the connotation of radiation hazards from unstable nuclear sources, although there is no logical rationale for such fear.
In NMR, a sample of material is placed in a strong magnetic field. The nuclei in the sample, each having a spin and therefore a magnetic moment, align and precess about the axis of the field. The other allowed quantum configuration is to align in the opposite direction (against the field). The energy needed to jump up to that state is proportional to the magnetic field and depends on the overall nuclear spin properties of the nucleus. Next, a smaller oscillating electromagnetic field, essentially radio waves, is applied. The frequency of the waves is increased until the energy of the oscillating field matches the energy needed to flip the nuclear spins. At this point the spins flip and therefore absorb the waves, which we can monitor. We call this special frequency the resonant frequency. By monitoring when and where in the sample the resonance occurs, we can deduce the types of nuclei that are in each location. 2.Please explain how a sound is actually a form of energy? In what medium do sound waves travel? Sound waves are longitudinal mechanical waves. Like all such waves, they can be propagated in solids, liquids and gases. Sound waves detected by human ears are typically transmitted through air, and they cannot travel through a vacuum. Sound waves are generated by the vibration of an object in (typically) air. The vibrations alternately compress and rarify the air, and these disturbances are transmitted to surrounding regions. The waves carry and transmit energy by alternately converting it from potential to kinetic energy as the medium gets compressed and then rarified in this oscillatory fashion. The amplitude of the wave is the degree of compression that comes with each passing wavefront. The energy in the wave is proportional to the square of this amplitude. 3. Considering, A current is connected to 115-volt power source. If a current of 5 amps flows in the wire, what is the resistance of the circuit? R = V/I = 115/5 = 23 ohms 4. Considering where your electrical power is generated. Does your local utility buy additional power from some other source? What kind of fuel or energy is used to drive the turbines? Are there pollution controls that restrict the use of certain kinds of fuels at your local power plant? My power comes from a power company that generates most of the power locally, at a nuclear power station. Here nuclear fuel heats water, and the steam is used to drive the turbines creating electric power. There are many federal and local regulations specifying how the nuclear fuel must be handled, maintained and disposed of. Many other regulations are in place to ensure that the river, from which the station draws cooling water, is not adversely impacted by chemical, nuclear or thermal pollution. Secondary diesel fuel is stored …show more content…
8.Please explain, what other wavelengths of electromagnetic radiation are used in medicine? Phototherapy, the controlled exposure to sunlight or ultraviolet light source, is used often in medicine for a number of reasons. For example, exposing the infant to ultraviolet rays or sunlight helps a jaundiced infant break down excess bilirubin or bile. Ultraviolet light has wavelengths in the 10 to 400 nm range (between visible light and X-rays in the spectrum). Lasers are used routinely to remove certain skin growths or even unwanted hair. They are also used widely in eye surgery and as a cauterizing tool in other surgery. Eye surgery utilizes eximer lasers at about 100 nm. Soft tissue surgery such as resurfacing procedures typically uses a 3 micron YAG laser or 10 micron CO2 laser.
Thermography is a medical imaging technique using infrared light. This passive imaging technique senses the thermal emission from the body at wavelengths greater than 8 microns, revealing the temperature of the body. Infrared light can also be applied as a heat treatment to patients.
9.Please explain, what is the wavelength of the carrier wave used by your favorite radio
MRI exploits the process known as nuclear magnetic resonance (NMR). In fact the technique used to be called simply NMR or NMR imaging, but the “nuclear” was dropped because of the connotation of radiation hazards from unstable nuclear sources, although there is no logical rationale for such fear.
In NMR, a sample of material is placed in a strong magnetic field. The nuclei in the sample, each having a spin and therefore a magnetic moment, align and precess about the axis of the field. The other allowed quantum configuration is to align in the opposite direction (against the field). The energy needed to jump up to that state is proportional to the magnetic field and depends on the overall nuclear spin properties of the nucleus. Next, a smaller oscillating electromagnetic field, essentially radio waves, is applied. The frequency of the waves is increased until the energy of the oscillating field matches the energy needed to flip the nuclear spins. At this point the spins flip and therefore absorb the waves, which we can monitor. We call this special frequency the resonant frequency. By monitoring when and where in the sample the resonance occurs, we can deduce the types of nuclei that are in each location. 2.Please explain how a sound is actually a form of energy? In what medium do sound waves travel? Sound waves are longitudinal mechanical waves. Like all such waves, they can be propagated in solids, liquids and gases. Sound waves detected by human ears are typically transmitted through air, and they cannot travel through a vacuum. Sound waves are generated by the vibration of an object in (typically) air. The vibrations alternately compress and rarify the air, and these disturbances are transmitted to surrounding regions. The waves carry and transmit energy by alternately converting it from potential to kinetic energy as the medium gets compressed and then rarified in this oscillatory fashion. The amplitude of the wave is the degree of compression that comes with each passing wavefront. The energy in the wave is proportional to the square of this amplitude. 3. Considering, A current is connected to 115-volt power source. If a current of 5 amps flows in the wire, what is the resistance of the circuit? R = V/I = 115/5 = 23 ohms 4. Considering where your electrical power is generated. Does your local utility buy additional power from some other source? What kind of fuel or energy is used to drive the turbines? Are there pollution controls that restrict the use of certain kinds of fuels at your local power plant? My power comes from a power company that generates most of the power locally, at a nuclear power station. Here nuclear fuel heats water, and the steam is used to drive the turbines creating electric power. There are many federal and local regulations specifying how the nuclear fuel must be handled, maintained and disposed of. Many other regulations are in place to ensure that the river, from which the station draws cooling water, is not adversely impacted by chemical, nuclear or thermal pollution. Secondary diesel fuel is stored …show more content…
8.Please explain, what other wavelengths of electromagnetic radiation are used in medicine? Phototherapy, the controlled exposure to sunlight or ultraviolet light source, is used often in medicine for a number of reasons. For example, exposing the infant to ultraviolet rays or sunlight helps a jaundiced infant break down excess bilirubin or bile. Ultraviolet light has wavelengths in the 10 to 400 nm range (between visible light and X-rays in the spectrum). Lasers are used routinely to remove certain skin growths or even unwanted hair. They are also used widely in eye surgery and as a cauterizing tool in other surgery. Eye surgery utilizes eximer lasers at about 100 nm. Soft tissue surgery such as resurfacing procedures typically uses a 3 micron YAG laser or 10 micron CO2 laser.
Thermography is a medical imaging technique using infrared light. This passive imaging technique senses the thermal emission from the body at wavelengths greater than 8 microns, revealing the temperature of the body. Infrared light can also be applied as a heat treatment to patients.
9.Please explain, what is the wavelength of the carrier wave used by your favorite radio