X-ray Diffraction
X rays can be defined as “electromagnetic waves of short wavelength,
capable of penetrating some thickness of matter.” Approximately the
same size as an atom, the wavelength of an X-ray is about 1 Ã… (10-10m).
They occur in the portion of the electromagnetic spectrum between
gamma rays and ultra violet light and have proved very useful in
determining crystal structures since their discovery on November 8th,
1895.
German scientist Wilhelm Roentgen was conducting experiments in his
laboratory on the effects of cathode rays. Specifically he was
observing the effect of passing an electrical charge through gases at
a low pressure. While doing so, Roentgen noticed something that
earlier studies had not picked up. While passing current through the
cathode ray, other rays were being given off that passed through all
everyday matter such as wood, aluminium and paper. Roentgen further
observed a surface he had coated with barium Platinocyanide that was
placed outside of the cathode discharge tube would still emit light,
despite the fact that it was concealed from the light of the
discharge. The conclusions that Roentgen came to were that a new type
of radiation had passed through the air and lit up the screen
(X-rays).
Due to this discovery in 1895, scientists were able to probe
crystalline structures at an atomic level. X-ray diffraction has been
in use in two main areas; for the finger print characterization of
crystalline materials and the determination of their structure. Each
crystalline solid has its unique X-ray powder pattern which may be
used as a clue for its identification. Once the material has been
identified, X-ray crystallography may be used to determine its
structure, for instance how the atoms pack together in a crystalline
state and what the distance and angle between the atoms are. We can
determine the size and shape of a unit cell for any compound most
easily using the diffraction of x-rays.
X-ray diffraction is the scattering of x-rays by crystal atoms,
The spectrum of an object is the variation in the intensity of its radiation at different wavelengths.
Note, that the shorter the wavelength of the light, the more the ray strikes the glass surface is refracted. Blue and violet rays are deflected more than red rays. The degree of the deflection is a case characterized by a value, the refractive index n. It varies from the different colours of the spectrum. The degree of refraction is given by Snellius's law of refraction:
How does the X-ray work? Well first off let me tell you the difference of light rays and X-rays. The light rays are visible light waves and x-rays is a light that is smaller than atoms in your body. You can’t see them with the naked eye like sun rays. X-rays will only pick up items and body parts that are hard and also made of calcium. That light will then project your muscle that would look like a light gray and your bone structure that will be white onto a black piece of radio graphic film.
In the story “The Adventure of the Speckled Band” the author Conan Doyle portrays many different narrative techniques. He uses these techniques to provide meaning for the audience as well as help them visualize the situation that was being described. The different techniques used are narrative discourse, suspense, conflict, close, and focalization in his story. Narrative discourses are events, to describe a series of events that are contingent one on another. Typically focuses on one or more performers of actions. Personal experience can influence narrative discourse due to the explaining of significant events in the life of the narrator. Narrative discourse is made up of setting, developing
The electromagnetic waves range from extremely short gamma rays, to long radio waves. Within that continuum is visible light which is the only light humans are able to perceive. As humans, we associate colour with the different wavelengths – blue being on the shorter side of the spectrum and yellow and red being on the longer side, while green sits in the middle. For humans to see anything, visible li...
Hi everyone, could you image one of the applications of x-ray was shoes-fitting in the past? While you were fitting a pair of shoes, the salesperson asked you to step on the x-ray shoe fitter to check whether the shoes fit with your foot. It is interesting, right? However, today I would like to focus on the condition that made medical x-ray to succeed. Before that, let’s look at some background information about x-ray. X-ray was discovered in 1895 by Wilhelm Roentgen. It is a kind of wave that can penetrate through living organisms. The thicker and denser body parts like bones, teeth and tumours will leave shadows on a phosphor screen which generate an image of the invisible body parts. Due to this feature, if someone is injured, it will be
X-rays and gamma ray photons are part of the electromagnetic spectrum. The twin nature of electromagnetic radiation is used to justify the wave and its behavior. A photon is a bundle of energy that can be identified by the equation E = hv. Where h is the planks constant and v is the frequency. The frequency is equal to the speed of light 3x10 8 divided by the wavelength. Therefore, high-energy radiations have a short wavelength and a high frequency.
X-Rays are beamed pass your body and then they are absorbed in different amounts depending on the density of the materials they pass through. X-Rays are used to see broken bones, metal plates that may have been placed or screws in a previous surgery, Arthritis ( shows your joints which can show evidence of arthritis). Dental decay is another common reason dentists use X-Rays to check if there are any cavities in the teeth. Osteoporosis, certain types of X-Ray tests can measure your bone density. Bone cancer, bone tumors can also be reveled in X-Rays. X-Rays can also be used to see the parts of the chest and abdomen for various reasons. Major risks involved in X-Rays is the amount of exposure of radiation you intake, though it is very minimal. Sensitivity to radiation depends on the age of the patient. Another factor in risks for X-Rays would be in some cases you are asked to swallow a tracer, or are injected with one. In rare cases some patients have allergic reactions, feel dizzy or warm, it has a metallic taste, lightheadedness, nausea, itching, and hives. In extremely rare cases It may even cause severe low pressure, anaphylactic shock, and cardiac arrest. Though these are extremely uncommon risks and results it could possibly
A Separation is a movie that deals simply with the discussion of truth, since the moment when a seemingly innocuous event - a divorce - triggers a butterfly-effect that causes unpredictable consequences. Director Asghar Farhadi turns the act of throwing someone out of a door into a catastrophic decision. The repercussions of this act reflect on the spectators, subtly implicating them and implying that they are as guilty of conventional human fallacies as the characters represented on screen. One substance of the film is the complexity of human relationships, in which family plays a crucial role in determining people’s subsequent actions and reactions. Farhadi’s central purpose is developed from inside out the spirit and personality of each character, and is not limited to the context of divorce or judicial conflict. Through this film, Farhadi exposes his anguish and discord with Iranian politics and religious principles adopted by most of the population. Also, he portrays a fascinating game of mirrors, each reflecting a number of central issues of modern life, such as the battle between the urban middle class and the suburban working class, the definition of justice, the power of religion and tradition in humans, the diffusion of pragmatic people, and the effect of progress in society. Farhadi uses of ingenious cinematic techniques as an attempt to touch the audience with a micro situation, in order to make it acknowledgeable that small circumstances can teach us about how to deal with the macro panorama of socio-cultural reality.
The visible eye can detect waves lengths between .4 millimeters and .7 millimeters long (Groleau 2011). We call this visible light. Look around you-- everything you see has waves of light bouncing off of it that your eyes detect and turn to images in your brain. Waves measuring less than .4 millimeters long are considered ultraviolet (UV) waves (Bitesize 2011). These ...
polycrystalline. It is equivalent to the combination of a number of single crystals attached together at some point.
how they are classified. For a long time, I’ve been interested in crystals, so I’
The Electromagnetic Spectrum is the range of frequencies of possible electromagnetic radiation. The Spectrum ranges from 0 Hertz up to 2.4x1023 Hertz. The exact wavelength limits of the Spectrum are unknown however it is widely believed that the short wavelength limit is equal to the Planck Length (1.616x10-35m) and the long wavelength limit is the length of the Universe.
It competes with the Auger effect, which results in emission of a second photoelectron to regain stability. The relative numbers of excited atoms that fluoresce are described by the fluorescence yield, which increases with increasing atomic number for all three series (Jenkins 1988: 6). High energy electrons are not the only particles which can cause ejection of photoelectrons and subsequent fluorescent emission of characteristic radiation. High-energy X-ray photons can create the same effect, allowing us to excite a sample with the output of an X-ray tube or any source of photons of the proper energy. In fact, in some applications of XRF spectrometry, X-rays from a tube are used to excite a secondary fluorescer, which emits photons that in turn are used to excite the sample. When X-rays impinge upon a material, besides being absorbed, causing electron ejection and subsequent characteristic photon emission, they may also be transmitted or scattered. When an X-ray is scattered with no change in energy this is called Rayleigh scattering, and when a random amount of energy is lost the phenomenon is Compton scattering. Scattered X-rays are usually problematic in XRF, creating high levels of background radiation (Anzelmo 1987 Part
In the conventional pulse oximetry we have 2 LED lights, Red and Infrared both having wavelengths of 660nm and 940nm respectively.