Essay About The History Of Chemistry

Essay about The History of Chemistry
Chemistry is the science of the composition, structure, properties, and reactions of matter, especially
of atomic and molecular systems (dictionary). And technology is the branch of knowledge that deals
with the creation and use of technical means and their interrelation with life, society, and the
environment, drawing upon such subjects as industrial arts, engineering, applied science, and pure
science (dictionary). Chemistry helps our advances in technology, and technological alterations that
affect our lives in many ways everyday. Because of science, we have complex devices like cars, X–
ray machines, computers, and phones. But the technologies that science has motivated consist of
more than just hi–tech machines. Technology extends our ... Show more content on Helpwriting.net
...
This makes it a type of ionizing radiation and making it harmful to living tissue. They are fully
controllable, unlike natural sources. But have been proven to be harmful to our health but enough
research has been conducted to ensure maximum protection to the patients. ("Artificial
Radiation").But also if you limit the amount of radiation exposure it will be safe for the patient to
use. Medical X–rays have a disadvantage because they expose people to radiation. FDA regulates
radiation–emitting products including X–ray machines. But everyone has a crucial role in reducing
radiation while still getting the maximum benefit from X–ray exams. ("Reducing Radiation from
Medical X–rays") But when treating cancer patients they may be healed through radiotherapy, where
beams of high energy X–rays or gamma rays from cobalt–60 are used. The ionizing capability of X–
rays is aimed to kill the malignant cells, so they can reduce the dose around the healthy tissue.
Artificial radiation is limited because of the risk factors it contributes. For example people have an
increased chance of developing cancer later in life or developing cataracts and skin burns caused by
exposure to very high levels of radiation. The X–ray machine has both its advantages and
disadvantages.
X–ray machines have had a major impact on our society. X–rays revolutionized how doctors
detected disease and injury. By 1970, most Americans were getting at least one
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Benefits Of Panoramic Dental Radiography
The Advantages of Panoramic Dental Radiography
DES 1200 Dental Radiology
Yanelys Ruiz
Miami Dade College The Advantages of Panoramic Dental Radiography
Panoramic Dental Radiography refers to a two–dimensional x–ray examination that captures a
single image of the mouth including surrounding structures like the teeth, tissues, the lower and
upper jaws. It shows a flat detailed image of curved structures such as jaws. X–ray radiography
exposes body tissues to some radiation during the procedure. Panoramic Dental Radiography is
extraoral technique that differs from intraoral because it is built with technology which offers more
coverage for periapical lesion, periodontal bone defects, and pathological jaw lesion with a
minimum risk of side effects to patients. The procedure reveals more details by covering a wide area
compared to intraoral x–ray and providing valuable information on bone abnormalities and tooth
positioning. Panoramic x–ray shows clear mouth anomalies such as jaw cancer, jaw disorder,
sinusitis, and periodontal diseases. All dental radiographer, including Dental Hygienist, should be
aware of how Panoramic Dental Radiography imagen can be helpful in order to visualize
radiographies with more accurate results.
According to Douglass, Valachovic, Wijesinha, Chauncey, Kapur, and McNeil (2004), Panoramic
Dental Radiography technology enables dentists to obtain mouth movement image patterns
including pan bitewings, standard pans, and pan periodical functions

Advantages And Disadvantages Of Digital Technology
Introduction:
Diagnostic Radiography has advanced and developed since its early discovery in 1895, by Wilhelm
Roentgen. In recent years, its dynamic development has progressed from conventional analogue to
computed, and digital radiography. The wealth of changes in the past two decades has seen many
departments in Gauteng convert to digital units. This report compiled on the Multix Fusion system,
from Siemens outlines the machine with specific attention to: terminology, equipment, capabilities,
advantages and disadvantages, image acquisition, applications, as well as the long term benefits
regarding to workflow, time and cost.
Terminology:
General:
1. kV: or Kilovoltage, is the maximum possible energy for any photon that exists in the x–ray ...
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This machine also includes a stationary grid that is fixated to the wall and patient table as well as a
moveable grid that can b used on patients that are X–Rayed directly.
Application Capabilities
This system may be used for examinations on both children and adults. The table can be used to
acquire images of the patient in a recumbent, sitting or prone position. The wall stand can be used
for patients that are standing or sitting. The digital images displayed on the system thereafter are of
excellent quality due to the proper understanding of the radiographer in terms of how to set exposure
factors needed to attain the level of contrast needed. (Siemens 2010; 39).
The Wall Stand
The wall stand contains the grid and has a holder for the detector. The detector unit can be
manipulated vertically or horizontally. The tube can be centred to the middle of the wall stand and
FFD adjusted to the required position depending on the type of examination being done at the time.
Examinations on the skull, spine, shoulder girdle, pelvis, abdomen, chest, as well as extremities can
be done on the stand provided that the patient is positioned accordingly and optimal exposure is
used. (Siemens 2010 page

Medical Imaging
Have you ever had an X–ray? What about an ultrasound or a MRI? If you have, you have been
exposed to one of healthcare's most innovative technologies. All these tests come together to form
the field of Medical Imaging. Medical imaging refers to the different technologies that are used to
view the human body to observe, diagnose, and/or treat medical conditions. Medical imaging has
played a major role in medicine for over the past one hundred years. Throughout this essay you will
discover Medical Imaging and its huge impact on the health field. Medical Imaging all started with
radiography in 1895 when Wilhelm Roentgen discovered x–rays. Experimenting in a dark
laboratory, with Crooks tubes wrapped in black cardboard, Roentgen notices light

Development of the Periodic Table, X Rays and the...
Chemistry has been the way of life for millions of years! It helps us develop new concepts of
thinking and finding solutions to our problems. Did you know that fire was the first chemical
reaction humans learned to use and control? (worldbook.com) Chemistry has helped our world come
up with new, advanced technology to benefit us all. Chemistry played a role in developing the
periodic table, x–rays, and the telescope. Primarily, the Periodic Table of Elements was primarily
thought to be developed by Dmitri Mendeleev. However, "Antoine Lavoisier first established the
modern concept of the element in the late 1700s" (worldbook). Mendeleev published his version of
the periodic table in 1869. Also, many scientists before Mendeleev ... Show more content on
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If it weren't for x–rays, how would doctors be able to detect abnormalities within a patient? The x–
ray was accidently discovered by physicist Wilhelm Roentgen in 1895. He discovered it when he
was experimenting with electric flow currents in a cathode– ray tube and saw a piece of barium
platinocyanide giving off light while he was working with the tube. His theory was that when the
electrons of the cathode–ray tube hits the wall of the tube an unknown radiation, went across the
room and hit the chemical, and then caused a fluorescence.(paraphrase, Encyclopedia Britannica).
Also, he thought since he couldn't find any light refraction or things similar to light, that this new
found thing was unrelated to light. He named it X–Radiation, this is also known as Rontgen
Radiation. (Fun fact: Roentgen can be spelled without the first e.) Rontgen also experimented
further and learned that paper, aluminum, and other metal things were transparent with this new
invention. His first x–ray was of his wife's hand. He looked at the bones in her hand and he looked
at the insides of metal objects with his new found machine. Also, Roentgen received a Nobel Prize
for his discovery. However, Roentgen wasn't the only man to discover something in chemistry
history. Who invented the telescope? It's currently a controversial topic amongst astronomers of the
world. Some say Galileo Galilei invented the

The Discovery Of X Rays
X–rays is one of the many discoveries that revolutionized the way the humanity functions
technologically, economically and socially in a fast changing world. This invention was thanks to
Dr. Rontgen. His invention changed the medical and astronomy field drastically and therefore he
was awarded the first Nobel prize in physics. He was awarded this incredible and highly valued
award in the year 1901 after producing, detecting and then discovering these high frequency
wavelengths produced by electromagnetic radiation. This Physicist and scientist later to be
recognized as doctor gave the world the gift of this amazing, invisible and powerful rays that would
change the world for ever. Willhelm Conrad Rontgen was born in March 27 on the year 1845, at
Lennep, in the big city of Remscheid which is located in Germany. He was an only child. His father
was a merchant who sold and manufactured cloth. His mother, Charlotte, came from family in
Amsterdam. When he was very young his family and him moved to the Netherlands. There he
assisted the Martinus Herman van Doorn institute, which was a school. A few years later he entered
another school at Utrecht but was unfairly expelled. As he got older Dr. Rontgen studied at ETH
Zurich which was Sencherman 2. also known as the Federal Polytechnic institute in Zurich. He
started his career as a mechanical engineer. In 1869 he graduated with a Ph.D. from that same
Polytechnic after having and outstanding academic result. Thanks to his immense

Taking a Look at X-Rays
The first human x–ray was taken and discovered by German scientist Wilhelm Roentgen's first
experiment with cathode tube rays. The photo taken was the hand of his wife, Bertha. On the photo
you can see a clear view of her hand through the flesh and bone. The first human X–ray was an
amazing discovery. Numerous people including scientists, and inventors were so fascinated by the
discovery that they started to experiment with cathode tube rays. But even so, x–rays have made
many contributions to the world from industrial purposes before medical purposes. Physicians used
x–rays for medical related injuries and they have progressed into new technology such as smaller
machines and better quality of photographs. X–rays in the 1800 were used for industrial purposes,
"for an industrial (not medical) application" (NDT Resource Center). In 1913, X– ray tubes were
changed when William Coolidge designed a high vacuum (NDT). The vacuum tubes were a reliable
source and operated up to 100,000 volts of energy (NDT). In 1922, the industrial radiography
moved forward. 200,000 volts of X–ray tubes that produced thick steel parts were manufactured in a
little amount of time (NDT). In 1931, volt X–rays moved up to 1,000,000, the generators helped the
industrial radiography with an intense and useful tool (NDT). The use of radiography in the 1930
was not accepted until the American Society of Mechanical Engineering approved and permitted
fusion welded pressure vessels to be accepted in the

How Did X-Rays Change The World
Imagine a machine that made what was once invisible, visible. Wilhelm Roentgen discovered the X–
ray in 1895. X–rays impacted the field of medicine greatly. The discovery of X–rays significantly
changed how we could see the human body, treatment options, and how we viewed X–rays.
Wilhelm C. Roentgen was a German physicist. He was born on March 27, 1845, and died on
February 10, 1923. He was married to, Anna Bertha Ludwig. He received education from the
University of Zurich, the Institute of Martinus Herman van Doorn, ETH Zurich and the University
of Strasbourg. He received the Nobel Prize in physics in 1901 for discovering X–rays.
When Roentgen first discovered X–rays, he didn't know what they were. He called them X–rays to
show that it ... Show more content on Helpwriting.net ...
This can help them diagnose, monitor, and treat many medical conditions," (Healthline.com). This
changed the world of medicine. Looking inside a human body using X–rays made diagnosing and
monitoring medical problems easier and more efficient. They no longer have to make incisions, they
can just use X–rays to see what going on inside of your body. Doctors are able to see inside the body
because the way the X–rays react with the density of the organs and bones inside of you. "Soft
tissue, such as skin and organs, cannot absorb the high–energy rays, and the beam passes through
them. Dense materials inside our bodies, like bones, absorb the radiation." (Wonderopolis.org). This
is why we are able to see bones and other things inside our bodies. "Black areas on an x–ray which
is flesh and soft tissue show where the X–rays passed through. White areas on x–rays show where
denser tissues like bones have absorbed the X–rays." (RadiologyInfo.org). The white areas that
show up on the X–rays are what allows the doctors to see the inside of the body. The doctors view
the body because of how the radiation reacts with the differences in density of organs, flesh, bones,

A Brief Note On X Ray Vision Goggles
Abstract
MRI's today are the solution to X–Rays by having radio waves go back and forth transmitting
signals that allow Doctors to see inside the human body. There are not many downsides of MRI's,
however MRI's do not fit in the average waiting room by being circular tube like machines that take
about 1 hour to produce a clear image of a patient's problem. MRI's are great when it comes to
mental disabilities but when it comes to broken bones, it is too time consuming to wait in the
machine for an hour to find out about a torn ligament or broken bone in a patient's body. A new
vision will take away the harmless effects of an MRI but also have it for every day needs in a
doctor's office. X–Ray Vision goggles would allow a doctor to see a patient's broken bone or
ligaments without effects of X–rays. Present Technology
Wilhelm Rontgen, a German physicist, had multiple experiments in 1895 he and found a type of
radiation which he labelled as the letter X, because he did not know what it was. His X–rays were
soon discovered by Doctors which primarily used them to look inside the human body. One original
component that has not changed since has been how they are developed and made.
X–Ray's are used to generate pictures that show the inside of the human body such as finding
broken bones. In Otto Zhou of the University of North Carolina, Dr Zhou and his colleagues are
bringing X–radiography into the world of modern electronics. In doing so, there is a hope to create
X–ray

How Did Wilhelm Roentgen Helped Society
Wilhelm Roentgen
Wilhelm Roentgen helped changed the medical society because of his invention of the x–ray, which
had changed many lives. It helped many people see what was going on that the naked eye couldn't
exactly see. He was very dedicated to his work which helped impact people's lives.
Wilhelm Conrad Roentgen was born on March 27, 1845 in Lennep, Rhine Province, Germany. He
was a German Physicist. He married Anna Bertha Ludwig in 1865 and they had one child named
Josephine Bertha Ludwig. Roentgen and his wife had adopted their daughter, who was Anna's
brother's daughter.
He attended the University of Utrecht. He later studied as a mechanical engineer at the Federal
Polytechnic Institute in Zurich, Germany. Roentgen graduated with a ... Show more content on
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He changed the cardboard covering and then used a black cardboard covering, which seemed to
work better to his advantage. He set up his experiment again, going through the process all over
again. Roentgen saw a light gleaming from the tube. He did that process more times, just to see if
the gleaming light was there each time. The gleaming light was now being shown on the black
cardboard screen. This was his creation, the x–rays.
Roentgen called his creation an x–ray because "x" was a variable that no one knew what it was and
"ray" came from his name, calling it "Roentgen Rays". He took the very first photo of his wife's
hand using the x–ray. His wife was very surprised when she saw her skeleton on the screen. With his
great accomplishment, he was rewarded the honorary "Doctor of Medicine" degree from the
University of Würzburg.
In conclusion, Wilhelm Roentgen may have not pertained to dentistry so to say, but he did help
tremendously. Without him, we would never have the x–ray units to explore the mouth more in
depth. We can see what is in the mouth and how the teeth are developing with the use of the x–ray
Roentgen had created. He may not have been a dentist, but with his work of the x–ray and how it
works it has helped a great

The Journey Of Energy : A Diagnostic Image
The Journey of Energy to Achieve a Diagnostic Image "Breath normally and stay still" Is what a
radiographer would say to Mrs. Watt before exiting the room to take an exposure of a left PA hand.
The .3 seconds that takes to capture the image on the IR is just one of the nine steps to produce a
quality diagnostic image. The energy needed to heat the tungsten filament is traced back to lower
granite dam in Washington where the energy is stored in Bonneville power and bought by Avista.
The power then streams across the snake river to Sacajawea hall into a wall outlet. The x–ray tube
housing unit is plugged into the wall outlet and inside the x–ray tube, the rotor produces the x–rays
which expose the anatomic part onto the IR. The nine steps that are required to produce an
acceptable and high–quality diagnostic image, starts at lower granite dam and ends with a manifest
image that helps radiologists determine the outcome of the patient.
The Energy
Lower Granite Dam In the area of Mayview Washington, just 47 miles away from Lewis–Clark
State College (LCSC) is where lower granite dam is located. The dam generates around 4,000
megawatts which in turns to about 4 million kilowatts to the Federal Columbia River Power System
(US ARMY, 2003). Although X–rays are measured by kilovoltage, the potential difference, and
kilowatts, the measure of power are the same. To use just 1% of the 4 million kilowatts generated by
the lower granite dam power system an x–ray tech could take over 650

Premolar Radiograph: Clinical Report
Clinical Tip #2
When taking bitewing radiographs digitally, it is best to take the premolar area first. When a
premolar radiograph is taken before the molars, it will give the practitioner a map for taking the
molar radiograph. If crowns are high under the tissue, it will allow it to be seen prior to the taking of
the next radiograph. This will give an idea of how high the PID needs to be placed near the facial
area of the molars.
Definitions
Alternating current (AC): Current flows in one direction, then the opposite direction in the circuit.
Central ray: That x0ray located in the center of the x–ray beam as it leaves the tube head.
Collimation: The process of restricting the size and shape of the x–ray beam.
Direct current (DC): Electric current that flows in one direction and does not reverse itself.
Electric ... Show more content on Helpwriting.net ...
The higher the settings, the more intense the beam being output from the PID. An increase in
exposure time will increase the intensity of the x–ray beam. But when the focal–film distance (FFD)
increases, intensity decreases due to divergence of a beam produces a larger field. I believe the half–
value layer (HVL) to be a harder concept to grasp, so I am writing about it in this lecture. HVL
represents the quality (penetration) of the x–rays emitted from the tube. HVL is the thickness of
aluminum (in millimeters) that will reduce the intensity of the x–ray beam by 50%. Be sure to read
all the pages in your chapters, so you will be ready to answer the questions in your study guide. Yes,
some of the information we will be learning in this class will not pertain to practitioners in offices
with digital radiography. However, you never know what life and job changes may come your way.
It is important to be ready to use regular film packets and know how to develop them. We will be
going over the study guide answers at our meeting for clinical

Taking a Look at X-Rays
X–rays have come a long way since 1896; new technology, materials and even machines have
changed the concept of a typical x–ray image since the discovery. New imaging techniques
described in Origin and Development of Medical Imaging apply in computerization to conventional
X–rays images. These images have incredibly improved and can be enhanced by digital techniques
and the extremely great effect of these x–rays is the reduction of exposure to radiation to the patient
(Doby, Alker 118). In the article, "Another Look Inside" quotes
Conventional CT scans are used to shape the place where a dose of radiation needs to be
concentrated in to attack a tumor without damaging any healthy tissue around that area. The scan
and treatment cannot be done at the same time due to interference with each other. But there is no
interference problems with the field–emission X–rays, they can be used to take high–resolution
images while the treatment is starting, which means those who are administering the treatment will
automatically know when to continue and stop (The Economist). In "Another Look Inside", states
the rays are created by the energy of impact. These X–ray machines have progressed over the years.
Tomography, CT scans, scanners that are used in hospitals have collected x–ray images that have
been taken from different angles and converted into three–dimensional images of internal organs of
a patient (The Economist). A prototype machine that has 52 field–emission X–ray sources is

69p Rad Sop Field Unit Essay
Standard Operating Procedures
Radiology
1. PURPOSE: a. To provide maximum quality radiographs in an efficient amount of time. b. To
establish responsibilities, procedures, policies, and techniques which prevent excessive radiation
exposure to patients and staff. c. To set guidelines to be followed for checking radiology systems
performance and maintaining optimum image quality and equipment safety for the technologist who
operate these systems and the patients as well. 2. SCOPE:
This SOP is applicable to all personnel assigned to 4th Division, 3rd Brigade, 64th Brigade Support
Battalion, and all Physicians Assistants (PAs) attached. 3. RESPONSIBILITIES: d. NCOs: i.
Responsible for ... Show more content on Helpwriting.net ...
| 10% of 10 CFR 20 Appendix B averaged over one year at the boundary; or listed value at the stack
| 10% of 10 CFR 20 Appendix B averaged over the calendar quarter at the boundary; or listed value
at the stack. | 30% of 10 CFR 20 Appendix B averaged over the calendar quarter at the boundary; or
listed value at the stack. |
5. Terminology: o. AP, PA, Lateral xii. Anterior–Posterior (AP)– radiographs that are taken with the
patient facing the x–ray tube. So that the x–ray beam enters their anterior side, and exits posteriorly.
xiii. Posterior–Anterior (PA)– radiographs that are taken with the patient facing away from the x–ray
tube. So that the x–ray beam enters their posterior side, and exits anteriorly. xiv. Lateral (LAT)–
radiographs that are taken while the patient stands sideways to the x–ray tube. They can be done
with either the patients left or right side next to the film. Left lateral x–rays are done with the
patients left side against the film, Right laterals are done with the patients right side against the film.
xv. Oblique– radiographs that are taken halfway between AP or PA and LAT. The patient will be
rotated about 45 degrees from lateral or frontal. 1. Left Oblique– Patients left side is

Did The Military Use X-Ray For Profit Or Health Purposes
X–Ray have been around since the late 1890s. It was created and used for medicine. It is an invisible
ray that can pass through solid matter. X–Ray was perfect for the use of locating broke bones
through the skin of a body. Shortly after it was produced for medicine, the military saw a better fit
for the new discovery. They took this invention, and they thought of a new way to use it. Countries
cannot produce more soldiers, but they can extend the lives of the soldiers they already have. The
advancement of X–Ray was started because of society. People wanting to prevent the deaths of
soldiers with bullet wounds. The actors were the military and doctors. Using STS, did the military
use X–Ray for profit or health purposes? Also, how the early years of 1900s were important towards
X–Ray development? Science, Technology and society is about society and technology working
together to shape, advance, and grow into the future. It is how humans pushed to evolve technology.
In this paper, the technical device we are looking at is X–Rays, and the military and doctors were
the actors to evolve it. Using the ... Show more content on Helpwriting.net ...
A scientist would need a glass tube with positive and negative electrodes. The tubes were called
cathode tubes, and they were common in the late 1890s. The air leaves the glass tube, and a
florescent glow is produced when a high voltage runs through the tube. The scientist needs to cover
the glowing tube with a heavy, black paper or cardboard. Then the scientist will see the green
colored fluorescent light illuminating from the box. This is known as the X–Rays which energizes
the phosphorescent materials in the room. The newly discovered ray would pass through objects,
and it can cast a shadow of most solid objects. The ray consists of electron passing through the
matter underneath the cathode tube. It can pass through human tissues, but it cannot pass through
bones and metal

The Effect Of Inverse Square Law On A Beam Of X Ray Photons
Experiment 1
Introduction:
The aim of this experiment is to investigate the effect of the inverse square law on a beam of x–ray
photons. The inverse square law states that the intensity of an x–ray beam is inversely proportional
to the square of the distance (Ball, J.L., Moore, A.D. and Turner, S., 2008). Similar triangles
(Appendix A– Image 1) are a proof of the inverse square law as it shows that if the distance from the
beam is doubled, the intensity falls to one–quarter of its original value. If it is trebled the intensity
falls to one–ninth and at four times the distance it is one–sixteenth its value, etc (Holmes, K.,
Elkington, M. and Harris P., 2013). The formula used to calculate this is:
This law only applies if the radiation is from a point source, the radiation of the beam is
homogenous (the photons must all have the same energy) and if there is no attenuation between the
source of radiation and the detector (Holmes, K., Elkington, M. and Harris P., 2013). However, the
x–ray beam cannot satisfy these three conditions of the inverse square law. This is because the x–
rays produced are not emitted from a true point source as the focal spot has a finite size. They are
not emitted equally in all directions as the anode heel effect causes the intensity to vary across the
beam and the absorption and scattering of the x–ray beam occur as it passes through the air
(Graham, D., Cloke, P. and Vosper, M., 2012). Despite this, the inverse square law can still be
applied

Polarization of X-Rays
Polarization of X–rays was first demonstrated by Barkla. He was performing experiments on the
secondary X–ray radiation phenomena (C. G. Barkla 1905). He used a block of graphite that scatters
the primary X–ray beam from an X–ray tube. The scattered intensity of the X–ray beam was
measured in two mutually perpendicular directions. He denoted the scattered intensity in a parallel
direction to the tube axis I_pand the one scattered at right angles I_s. The degree of polarization for
X–rays emitted at an angle θ to the direction of the electron beam is given as (Agarwal 1991):
P_(pol(θ))=(I_s–I_p)/(I_s+I_p )
Barkla found that for θ=90°,I_p was larger than I_s by ≈20%. This discovery that X–rays can be
partly polarized proved that they are transverse electromagnetic waves. However, Barkla actually
studied and measured the polarization of the bremsstrahlung (continuous) radiation.
When electrons emitted from a heated cathode filament are accelerated by a potential difference U
and impinge onto an anode target (for example tungsten), the motions of the electrons with in the
target are influenced by the strong Coulomb fields of the atomic nuclei. As a result, the electrons are
decelerated within small distances and; consequently, a broadband bremsstrahlung or continuous
radiation is produced. Figure 2.3. PENELOPE simulated spectrum of a bremsstrahlung from a
tungsten metal for 20 keV electron beam energy
The intensity distribution of the emitted broad radiation continuum

Research Paper On Breast Mammography
Breast Tomosynthesis
When people are asked about preventive medical care for women, they usually think about
mammography. Mammography is a type of breast imaging that uses x–rays to help detect breast
cancer and other abnormalities. 1 in 8 women will be diagnosed with breast cancer in their lifetime;
it is the most commonly diagnosed cancer in women. Using mammography as a screening tool for
breast cancer has a major impact on the mortality rate. It has been associated with a 15% to 20%
reduction in mortality from breast cancer.
Mammography made its big breakthrough in the 1960's and since then, it has made many
improvements. Breast tomosynthesis is a fairly new type of breast imaging that provides a more
accurate, and clearer view compared to mammograms. Mammograms are two–dimensional and
tomosynthesis is a 3D ... Show more content on Helpwriting.net ...
A mammogram machine is composed of a digital detector, compression plate, and the x–ray tube. A
DBT (Digital Breast Tomosynthesis) machine is made up the same equipment except that the x–ray
tube is not a fixed fixture mounted to the machine but rather moves around the breast, so it can get
several images at different angles. With a normal tomosynthesis machine used for other
examinations, the detector normally moves with the arc of the x–ray tube. When developing the
DBT machine, there were two prototypes that emerged. In the first one, the detector moved with the
tube. In the second prototype, the detector was stationary and the arc of the tube moved around it.
The problem that arose with having the detector move with the arc was that you would have much
more magnification of the breast tissue (Baldwin 2009 p. 60). Today, we use a stationary detector
and the only problem using this method is that it produces more scatter. Positioning is the same as
with a normal mammogram, although compression is reduced, making it more comfortable for the
patient (Reynolds 2013

X Rays History
X–rays Science Assessment 9B
History
X–rays are used for medical purposes. They are a form of radiation named electromagnetic waves
(EM Radiation). They are used to take pictures of the insides of the human body which come out in
black and white. The X–ray was first developed in 1895 by a man named Wilhelm Conrad
Roentgen. While He was working with a cathode–ray tube in his laboratory, Roentgen observed a
fluorescent glow of crystals on a nearby table close to his tubes. The tube that he was working with
consisted of a bulb with positive and negative electrodes enclosed within it, when the air inside of
the tube left and when a high voltage was applied to it , the tube produced a fluorescent glow.
Roentgen then shielded the tube with heavy ... Show more content on Helpwriting.net ...
(14/3/2014). What are the risks and benefits of X–rays?. [online] Available at:
http://www.nps.org.au/medical–tests/medical–imaging/for–individuals/types–of–imaging/x–
rays/for–individuals/risks–and–benefits [Accessed 12 Mar. 2016].
Why was it reliable: Because it gave me the tight facts that were relevant to the topic I was
researching. It is an Australian sight used by Latrobe university students. It was referred to me by
my cousin who is taking a course in Science.
Royal Institution of Australia. (13/11/2015). History of the X–ray – Royal Institution of Australia.
[online] Available at: http://riaus.org.au/articles/history–of–the–x–rays/ [Accessed 13 Mar. 2016].
Why was it reliable: Reliable because it is a royal intuition of Australia sight developed and used by
highschools, primary schools and colleges.
Newman, T. and Newman, T. (1/4/2016). X–Ray Exposure: How Safe Are X–Rays?. [online]
Medical News Today. Available at: http://www.medicalnewstoday.com/articles/219970.php
[Accessed 12 Mar. 2016].
Why was it reliable: It was reliable and trustworthy because it is a medical news sight that is very
popular. It provided me with relevant facts to do with my

Physics Of X Ray Fluorescence
X–Ray Fluorescence (XRF) Spectrometry
The JSX–3222 analyzer is an energy–dispersive fluorescent X–ray spectrometer developed to
analyze cadmium (Cd) included in plastic and the electric wire film material, etc. promptly. The
range of elements that can be measured is from sodium (Na) to uranium (U).Liquid–nitrogen
cooling for the high performance detector is required only during the analyzing time. The vacuum
and atmosphere are switched to the measurement atmosphere by the operation of one button. When
X–rays (primary X–rays) are illuminated from the X–ray tube to the specimen, fluorescence X–rays
having wavelengths (energies) peculiar to the constituent elements of the specimen are generated
from the elements.
Qualitative analysis can be made by investigating the wavelengths of the fluorescence X–rays and
quantitative analysis by investigating the X–ray dose. The energies are investigated by two methods.
One is to optically separate them and the other is to use the energy separation characteristic of the
X–ray detector. The former is called the wavelength dispersive method an: the latter the energy
dispersive method. The element analyzer employs the latter method. As seen from the figure, since
the energy dispersive X–ray spectrometer has no moving parts employs a simple optical system, its
structure is simple and compact. And since the detector can be installed the specimen, the X–ray
solid angle of collection can be made large, thus offering many features such as

Year 12 Hsc Physics Research And Analysis Assignment
Medical Physics Research and Analysis Assignment
Nathan Chang
Year 12 HSC Physics Assessment Task No: 4
X–rays and CAT scans – What they are and how they are produced
What X–rays are – Clearly explains what an X–ray is
X–rays are electromagnetic waves of very short wavelength and high frequency, in the range
0.001nm to 10nm. Due to their high frequency (therefore meaning high energy), x–rays penetrate
flesh and may cause ionization of atoms they encounter. The body tissue absorbs energy and the
intensity of the beam is reduced when x–rays pass through the body. Denser material, such as bone,
absorbs more X–radiation.
– X–ray of Human Hands
How X–rays are produced – Clear and comprehensive explanation, including diagram, of how x–
rays ... Show more content on Helpwriting.net ...
There are various positive and negative effects of the impact of medical applications of physics on
society, such as raising the standard of care for human beings, as well as being ethically challenged
(right vs. wrong).
Firstly, the advantages of early diagnosis enable patients to be treated earlier and faster, which is
very important for a lot of diseases and problems. Early diagnosis from these medical applications
save many lives and helps many people. For example, chest X–rays have allowed for the early
detection of tuberculosis in miscellaneous chest infections, which may have otherwise been left
undetected and eventually death.
Secondly, the negative economical impact such as the cost of building and operating these medical
physics machines, burdens the economy and people in the society. Diagnostic tools such as PET and
MRI consume a huge amount of electricity to operate, as well as needing to be constantly
monitored, resulting in a further impact on staff. Closely linked to this, is also that MRI and PET
scans are very expensive and few hospitals have access to them, resulting in only patients of a
particular economic status (affordability) and geographical location (city or

Background Information : Airport Security
BACKGROUND INFORMATION Airport security is currently seen as one of the biggest
inconveniences attributed to travel. However a brief look back in history to some of the conditions
frequent flyers were subjected to makes modern air travel look like a breeze. Some of the earliest
attempts at flying required an excess of manpower. Leonardo da Vinci is credited to be the first to
design basic flying machines called ornithopters, that gave man mechanical wings. Through a
system of pulleys the wings could be moved imitating bird's flight but ultimately was unsuccessful
as a human being lacks the power necessary to keep these contraptions in the air. [1] Gases were
then discovered that were lighter than air such as hydrogen and helium popularising balloons and
airships. These balloons soon deflated stranding expeditioners in water or remote areas often
drowning or dying from exposure to the elements. An improvement on this design utilised multiple
cells but large masses of flammable gases caused disastrous deaths when they went up in flames. [2]
Advancing technology lead to the discovery that fixed wings for airplanes were much more
practical. Again looking to birds for inspiration the Wright Brothers are credited as the first to design
wings with adjustable panels built in, imitating how birds change direction with the tips of their
wings. Incorporating an engine provided the power to accelerate to speeds necessary to take flight
and so the modern airplane was born. Engineers

Radiology Essay
Introduction
In Radiology, they use different imaging modalities to see within the human body. These modalities
are used to diagnose abnormalities and diseases. Some of these techniques include Magnetic
Resonance Imaging (MRI), Ultrasound, X–Ray, Mammography, Nuclear Medicine, Interventional,
and Radiation Therapy. Each of these uses a different purpose and technology to achieve its goals.
Magnetic Resonance Imaging (MRI) An MRI is a medical imaging technology that uses radio waves
and a magnetic field to create detailed images of organs and tissues. MRI is often used to evaluate
blood vessels, abnormal tissue, and organs in the pelvis, chest, and abdomen. It also sees use for
bones, joints, and spinal injuries.
Ultrasound
Ultrasound, also called sonography or ultrasonography. Ultrasound machines send high frequency
sound waves into the body and measures the returning sound echoes. It then converts the received
pattern into an image, ... Show more content on Helpwriting.net ...
This information is sent to the display console, which is the processing and display program that
controls the digital image production processes. This includes the series of mathematical formulas
that compile the image and the display parameters, such as window level and width, reconstruction
and enhancement. Richard R. Carlton. Arlene M. Adler. Principles radiograph imaging. Fifth edition
Advantages
CT scans are not only accurate, they are very quick. The imaging provided by the exams may
eliminate the need for surgery, saving money and resources. The flexibility of the CT exam allows it
to evaluate symptoms and diagnose issues in both adults and children. ''Decreased amount of
contrast medium, improved image quality, improves spatial resolution. It also makes possible
procedures that require shorter exposure times.'' Quinn B. Carroll, M. ED., R.T. Radiography in the
Digital Age. Second

Computed Tomography Research Paper
Lucas 1
Jennifer Lucas
Professor Mealey
CHEM 1305–008
24 July 2017
Computed Tomography Scan Computed Tomography is more commonly known as a CT scan. This
medical instrument uses x–ray radiation, which "combines multiple x–ray images into a 3D model
of a region of interest," (Lucas 1). The various organs in the body absorb x–rays differently. A
computer monitors the process of absorption with "30,000 x–ray beams," (Timberlake 171), that is
directed at the organ being scanned, such as, the brain. An x–ray wavelength has two different types,
a soft and hard x–ray. A soft x–ray wavelength ranges between "3x10^16 hertz to about 10^18
hertz," (Lucas 1). On the other hand, hard x–rays range between "10^18 hertz to higher then 10^20
hertz, with a wavelength from 100 pm to about 1 pm," (Lucas 1). CT scans give doctors specific
information about their patient. A CT diagnostic scans different types of organs such as the heart,
brain, and lungs. Doctors and physicians use this medical instrument in detecting diseases such as,
"hemorrhages, tumors, and atrophy," (Timberlake 171). Meaning, a CT scan helps identify the
stages of a disease and how far along it has spread such as cancer. A CT scan works by a patient
being placed in the tube of the CT machine. The beams from the x–ray go all around the patients
body in "360 degrees," (ASNR 1). As the beams pass through the body, different tissues absorb
different amounts of an x–ray beam. During the x–ray, the tube and detectors are constantly
Lucas 2 moving around the body. Detectors measure how the tissue in the body has changed. ...
Show more content on Helpwriting.net ...
General, Organic, and Biological Chemistry: Structures of Life. Boston: Pearson, 2016. Print.
"Computed Tomography." Brain, Head, & Neck, and Spine Imaging: A Patients Guide to
Neuroradiology. American Society of Neuroradiology, n.d. Web. 22 July 2017.
Lucas, Jim. "What Are X–Rays?" LiveScience. Purch, 12 Mar. 2015. Web. 22 July

The Visual Representation of a Body Part in Imaging...
Imaging technology is the visual representation of a body part, such as an organ, for the purpose of a
medical diagnosis. Nowadays, technologies such as X–Rays, Magnetic Resonance Imaging (MRI)
and ultrasound are used everyday for medical analysis. X–Rays are very useful because they can
penetrate through different materials to give an image of the interior of the body. MRI use strong
magnets to create an image of a body part, while ultrasound imaging uses sound waves.
Bone, muscle and fat absorb x–rays at different levels, so the screen lets see different structures of
the body because the different levels of exposure are in different shades of gray. The main
component of an x–ray machine is a vacuum tube with a cathode or filaments and an anode, which
is usually made of tungsten, a hard–steel gray metal used to make electric light filaments. Electric
current passes through the filament, raising its temperature. Once it reaches a certain level of energy,
the filament starts emitting negatively charged electrons. These electrons are attracted with great
force from the positively tungsten anode, taking them through the vacuum tube at very high speed.
In one of the atom's lower orbital an electron gets knocked away when the anode collides with
electrons. An electron from the higher orbital takes place of the removed electron, releasing energy
as an X–ray photon. (HowStuffWorks–X–Rays) Called 'bremsstrahlung', the reaction contains x–
rays of varying wavelengths. The X–ray

Correlation Between Target / Filter Combinations
Introduction
Currently, in the United Kingdom breast cancer is the most common type of cancer in women and
early diagnosis is the key to reducing mortality rates (Skaane et al, 2007).
The National Health Service breast screening programme introduced digital mammography as the
preferred option due to its increased sensitivity and specificity for denser breasts. Additionally, it has
the ability to manipulate the images produced (NHSBSP, 2012). The aim of this study is to
investigate the relationship between target/filter combinations, kilovoltage (kV), radiation dose and
image quality using a mammographic phantom which is currently used for the quality assurance
programme in the breast imaging department.
Digital x–ray technologies ... Show more content on Helpwriting.net ...
As the kV is reduced, scattered radiation is less penetrating. Therefore radiation dose to other
radiosensitive organs can be reduced. However the skin radiation dose can increase as the kV is
reduced (Allisy– Roberts and Williams, 2008). So by taking images at a higher kV should give a low
contrast image which may not show the low density structures within the breast phantom.
If the kV is increased it is expected there are more photons reaching the detector resulting in an over
exposed image which may possibly obscure small areas of micro calcifications and low density
masses. However, digital mammography can compensate to some extent for over exposure. On the
other hand over exposure should be avoided to comply with the ALARP (as low as reasonably
practicable) principles (DoH, 2012).
Filter material
Filter materials in mammography are made of molybdenum or rhodium. The purpose of filters is to
let through the useful photons and to absorb unwanted low and high energy photons so that they
stop reaching the image detector thus contributing to the formulation of the radiographic image
(Bushberg et al, 2002).
With the use of filters there is an increase in the quality of x–ray beam but a reduction in the
intensity (Ball and Price, 1995). Therefore filtration is necessary but photons from the low end of
spectrum if they are not

Difference Between Conventional Ct And Cbct Imaging
Introduction
Cone–beam computed tomography (CBCT) is a valuable tool used in dentistry. It can offer various
advantages as mentioned by Delamare (2016): its smaller size and lower cost compared to the
conventional computed tomography (CT), fast acquisition, submillimeter resolution, a patient
radiation dose that is relatively low (approximately 0.08 mSv average) and user friendly interactive
analysis features. Clinicians can use CBCT to determine the location of impacted teeth or the
inferior alveolar nerve, treatment planning for implant placement, endodontic evaluations or TMJ
assessments and lastly aid in locating the full extent of odontogenic pathology.
Main Differences Between Conventional CT and CBCT Imaging
There are several differences that distinguish conventional CT from CBCT. A traditional CT scanner
is composed of an x–ray tube that transmits a fan–shaped x–ray beam. These x–rays beams are
directed through the patient and are captured by a detector ring. The detector ring will process the
amount of photons exiting the individual in order to yield a single plane image per scan (White and
Pharoah, 2009). Each single–plane image is composed of pixels. The product of the collimation of
the scanner will produce a voxel, which is the volumetric element of a pixel. A rectangular shaped
"real" voxel is obtained from conventional CT scanners. Computer software will reformat the
rectangular shaped voxels into a cubic format that can be reconstructed into three

The History of the X-Rays Essay
During the cold winter of 1895, a German scientist by the name of Wilhelm Conrad Roentgen was
working with a cathode–ray tube when he noticed nearby crystals were glowing. When Roentgen
reached for the crystals he was amazed when the shadow cast on the crystal was not of his whole
hand, but just his bones. Roentgen covered the tube with heavy black paper and saw that the crystals
still glowed and the shadow of his hand bones still shown through, he then determined that a new
ray was being emitted that could penetrate through thick materials. (1.) He later found that the rays
could pass through most anything, but would cast a shadow of solid objects; these shadows could
then be captured on film. Among the solid objects Roentgen shot with ... Show more content on
Helpwriting.net ...
The Coolidge tube could operate to energies up to 100,000 volts. General Electric went on to make
x–ray tubes capable of operating at energies up to 1,000,000 volts, which gave the x–ray technology
enough stability to become industrialized and mass produced.
With this stability and mass production, x–rays machines became very common everywhere. From
large factories, to doctors offices, all the way to the corner store of small towns, where children and
adults alike could insert a coin into a machine and view the bones in their feet. (3.) Because of their
relative adolescences in the world, not much was known about x–rays or their effects on the human
body. The first theories about the rays' effects on the human body were that they had beneficial
applications. With this being the only theory about their effect, widespread use went on,
unmonitored, and unregulated. This unregulated use led to injuries but because of their slow onset
the injuries were never attributed to x–rays. While some scientists tied certain skin burns to over
exposure of x–rays it wasn't until popular minds of the world like Thomas Edison, Nikola Tesla and
William J. Morton expressed that they experienced eye pain when dealing with the rays for extended
periods of time that people began to connect the dots and understand the negative

The Discovery of X-Rays Essay
The Discovery of X–Rays
X–rays were discovered by accident in 1895 by the German physicist Wilhelm Conrad Roentgen.
Roentgen was already an accomplished scientist with forty–eight published papers. He had a
reputation among the scientific community as a dedicated scientist with precise experimental
methods. Roentgen had been conducting experiments at the University of Wurzburg on the effect of
cathode–rays on the luminescence of certain chemicals. Roentgen had placed a cathode–ray tube,
which is a partially evacuated glass tube with metal electrodes at each end, in a black cardboard box
in his darkened laboratory. He sent electricity through the cathodre–ray tube and noticed something
strange his laboratory. He saw a flash of light ... Show more content on Helpwriting.net ...
During an experiment he placed his hand between the source of the X–ray, the cathode–ray tube and
a screen and saw the faint outline of the bones of his hand. It was the first X–ray picture. The more
dense bone absorbed more X–rays then the less dense flesh producing an image of his hand. He
soon learned that photographic plates were sensitive to X–ray as they are to light and was thus able
to make the first X–ray photography. These first "Roentgen exposures" were of various metal
objects that were locked in a wooden case and of his wife's hand.
On December 2, 1895, Roentgen sent his paper titled, "Concerning a New Kind of Ray: Preliminary
Report" to the Physical–Medical Association who published it in their 1895 volume of the minutes
of the association. His report was soon published in several magazines around the world and in daily
newspapers causing a tremendous stir. On January 23, 1896, about a year before the Invisible Man
was published, Roentgen delivered his first public lecture on X–rays at the meeting of the Physical–
Medical Association. During the lecture, he asked a well known anatomist to have his hand
photographed using X–rays. The photo came out good and was passed around. The hall erupted in
applause and cheers for Roentgen for everyone saw the practical uses of this new ray. Less than
twenty days after the lecture, an X–ray machine was used in the United States to locate a bullet in a

Windows on the Universe: Refracting Telescopes
How It Works– Refracting telescopes use two glass lenses to gather and focus light. They bend, or
refract light as their name suggests, as it passes through different mediums. The objective lens
gathers and then refracts it to a focus near the end of the tube. The image is magnified and brought
to the viewer's eye by the eyepiece.
Information It Provides– Optical telescopes are used to observe objects, which are in the visible
light spectrum, by magnifying the image and thereby improving the detail. It provides information,
such as appearance and motion, on celestial bodies which would otherwise be too difficult to see
with the unaided human eye.
Advantages and Disadvantages
Advantages Disadvantages
High contrast images as there is no secondary mirror which obstructs some light Lenses are
expensive and time–consuming to manufacture
Closed tube protects optics from dust, moisture, light and air currents which degrade the image The
amount of refraction on the lens depends on the wavelength so different wavelengths focus at
slightly different places. This is chromatic aberration, a problem where a rainbow halo appears
around images.
Needs little maintenance. It is more resistant to misalignment than the reflecting telescope Heavier,
longer and bulkier than other telescope types
Optical Telescopes– Reflecting– Ground Based
Example– W.M. Keck Observatory (Hawaii, US)
How It Works– Instead of using lenses to gather light, these telescopes use concave, primary mirrors
at the

Wilhelm Rontgen and the Nobel Prize Essay
Wilhelm Conrad Rontgen was born on March 27, 1845 in Lennep, Prussia; which is now
Remscheid, Germany. His family moved to Apeldoorn in the Netherlands, where we went to
Institute of Martinus Herman van Doorn, a boarding school. He did not show any special aptitude,
but he had a fascination with nature and loved roaming the countryside and walking through forests.
Later he attended a technical school in Utrecht, but unfortunately was unfairly expelled for allegedly
drawing a rude caricature of one of the teachers, which was in fact drawn by another student. He
then entered the University of Utrecht in 1865 to study physics. He did not have the required
credentials to enter the University, but he heard he could enter by passing an exam. He ... Show
more content on Helpwriting.net ...
He named this new discovery "X–Ray" because x is the term for an unknown number in
mathematics. It was later called "Roentgen Rays" although changed back to "X–Ray". With his new
discovery, he found that the rays would travel through human tissue, but leave a shadow of bone and
metal behind. One of his first experiments was on his wife Bertha's hand with a ring on her finger in
1895. Medical X–rays work by letting fast moving electrons come to a sudden stop on a metal plate.
They show up different on the radiograph because of different absorption rates of different material.
The calcium in bones absorb the most x–rays so they appear white on a radiograph, or the film x–
rays are displayed on, although other things like tissue, fat and skin absorb it less so they appear
grey. Air absorbs the least x–rays so this is why lungs look completely black on a radiograph.
Todays x–ray machines are much faster, more efficient and produce much less harmful radiation.
Excessive exposure to x–rays can be dangerous but in modern medicine doctors are able to keep us
safe with their knowledge on this. The original x–ray machine took 90 minutes and produced 1500
times the radiation as modern x–rays. Wilhelm Conrad Roentgen has made a huge impact on todays
technology. It's obvious to see that inventing the x–ray is a big deal, but this was actually a very big
accomplishment and made a lot of new things possible. Without the x–ray our ability in the medical
world would be

X-Rays: From Discovery to Practical Application Essay
X–rays
This is a scientific report on x–rays, it's history, uses, implications and other relevant facts. More
relevance will be given to its medical uses/ importance as it was the most beneficial trait that x–rays
brought.
X–rays were discovered in 1895 when Wilhelm Conrad Röentgen was doing some experiments with
electron beams in a gas discharge tube and observed a glow in one of his fluorescent screens
whenever the electron beam was on.
It was a fact that fluorescent material usually glowed in reaction to magnetic radiation but the gas
discharge tube was surrounded by heavy black cardboard which was assumed by Roentgen to block
most of the radiation. Confused and curious, Roentgen then put several objects between the tube and
the ... Show more content on Helpwriting.net ...
The denser areas are shown as white while the soft areas appear dark in the film but sometimes
some organs may block x–rays from showing broken or cracked bones and for this reason CAT
(Computer Axial Tomography) was invented. Firstly, the person requiring the scan is put inside of a
scanner, which is a long tube–shaped machine and then x–rayed from all angles, after a computer
puts all of the images together so that doctors can analyse them. CAT are mainly used for head and
brain injuries and appropriate shielded should be provided to cover the areas not being x–rayed.
At the dentist the same principle applies, x–ray film is put in one side of the teeth and x–rays are
shot through the jaw, metal is more absorbent than teeth and bones so any filling on the teeth would
appear lighter in the x–ray film. Fig. 2
Exposure limits exist to prevent exposure and limit chronic exposure to "acceptable" levels because
in fact there is no safe level of exposure as there is always a small probability of exposure being the
cause of some ailments, like cancer. It is then recommended to keep levels of exposure "as low as
reasonable achievable" (ALARA).
A person can safely get up to 300 simple x–rays a year or 5 CAT (Computed Axial Tomography)
scans and the risk of developing cancer would only increase by 1% as in most cases the cells that get
damaged due to radiation die prematurely. The amount of cell damage from an x–ray is many times
less than

Introductory Medical Radiation Science Lab Report
Tori Stone
11574902
MRS110
Introductory Medical Radiation Science
Group: D
Date of Practical: 9th April 2015
Due Date: 29th April 2015
Y
I declare that this is all my own work;
Objectives: Gain an understanding of:
The use of an x–ray unit;
Setting radiographic exposure factors;
Set–up the computed radiography (CR) unit;
Understand the relationship between the x–ray tube, the patient (or object being radiographed) and
the image receptor,
Digitizing and viewing CR images and manipulate image brightness and contrast in the image,
To understand the difference between the CR unit and PACS
The use of the Synapse PACS system; and
Viewing image information such ... Show more content on Helpwriting.net ...
The image captured was clear, and with slight alterations with the contrast between the phantom and
the background the image was visible and to a high quality standard. The s–value used was 70,
ensuring the highest quality photo was taken, whilst ensuring the lowest possible dose to the patient.
The phantom was placed slightly towards the top of the image receptor however the hand was still
entirely visible in the final image.
I also believe I have gained an extensive knowledge and understanding on how the x–ray unit works
and the processes in taking an x–ray.
In the x–ray theatre enclosed shoes were worn at all times, we also stood behind lead lined glass
when taking the images to ensure the lowest unnecessary exposure to radiation. Along with this,
radiation signs were turned on above the doors outside whilst in the lab was in use alerting other
people using the rooms that radiation was in use. These safety procedures are extremely important in

the lab as we are exposed to large amounts of radiation during our time as radiographers.
Referencing:
Radiographic Imaging & Exposure (2012) (2nd ed., p.26). Richmond,

Richardson-Dushman Theory Of Thermionic Emission
Use the Richardson–Dushman theory of thermionic emission to determine the emission current
density for a tungsten filament at a temperature of 2600K
Thermionic emission is the process by which free electrons are emitted from a metal when an
external energy is applied towards the metal. When a smaller proportionate heat energy is applied to
the metal, the valence electron will gain enough energy and break the bond from the parent atom.
Once broken free, the free electrons in the metal may have some kinetic energy. However, there is
not enough to escape the metal. The process of Thermionic emission is widely used as a source of
electron in electron tubes, the heat supplies some electrons with at least the minimal energy required
to overcome the attractive force holding them in structure of the metal. (Encyclopedia Britannica,
2017)
Richardson–Dushman's equation relates to the theory of thermionic expulsion, which determines
that 'thermionic emission, discharge of an electron from heated materials.' This theory is widely used
as a source of electrons in conventional electron tubes.
Thermionic emission is a process of emission of charge particles (known as thermion) from the
surface of a heated metal (Simion.com, 2017)
Js=A×T^2 e^(((–W)/kT) )
Where
"Js" is the current density of the emission (mA/mm2)
"A" is richardson's constant. A = 4*πmek2/h3 ~ 1202 mA/mm2K2, m is the mass of electron, e is
elementary charge, h is Plank's constant
"T" is temperature (K)
"W" is the work

Shape Distortion: The Use Of Angulation In Radiology
The term angulation when used in radiology refers to the direction and degree of the x–ray tube
when it is moved from its standard "start" position, which is always perpendicular to the to the IR in
the Bucky tray. There are countless projections that utilize tube angulation for various reasons.
Frequently, projections use angulation to avoid the superimposition of different anatomic structures.
The reason angulation is used is to cause a controlled or expected amount of shape distortion. Shape
distortion is altering the typical anatomic layout of a structure and usually involves the elongation or
foreshortening of a structure. The direction and degree of angulation directly influence the amount
of shape distortion seen on a radiograph. Alignment of the anatomical part can also affect the image.
Shape distortion is when an image appears either longer or shorter based on the way it is positioned
in relation to both the central ray and the image receptor; foreshortening is when the object appears
shorter than it is in reality, while elongation is when the object appears longer than it truly is. When
imaging a part, the long axis is intended to be placed perpendicularly to the central ray and parallel
to the image receptor. Distortion happens when either the part or the central ray/image receptor are
placed incorrectly. In addition, distortion can also occur due to standard divergence of the beam. The
central ... Show more content on Helpwriting.net ...
Although, size and shape distortions are initially sound quite complicated, once a radiographer has a
basic understand of the elements that affect each factor, it can be either minimized or used to
improved image quality. Regardless of the situation, a radiographer must understand distortion, as it
is a component that will be faced every day in the field of

Ctp Lab Report
PHYSICAL PRINCIPLES
An x ray is similar to light and has both particle and wave nature. That basic working of a x ray CT
scan is the photons of x ray radiation comes in contact with the electron clouds in atoms. This can
happen either by photo electric effect or by scattering.
COMPTON SCATTERING
The first type of interaction of x rays in CT energy range is scattering and one of it is Compton
scattering. In Compton scattering photons interact with the outer shell electrons of the atom an ejects
it from the atom thereby ionising the atom. The ejected electron is then absorbed by a neighbouring
atom. The probability of scattering depends on the electron density of the atom that is more the
electron density more the chance of scattering. ... Show more content on Helpwriting.net ...
The filament adjacent to the cathode is heated up and the energy is absorbed by the electrons and
gets ejected of the cathode. The electrons travel towards the anode and hits the tungsten target and
rapid deceleration of electrons occurs and this deceleration results in production of electromagnetic
radiation that is x–rays. The anode keeps on rotating so that the heat will be lost to a larger area.
SENSORS /DETECTORS
The x–rays leaving the object must be studied to create images. Basically there are three types of
detectors.
Ionisation chamber filled with gas
Scintillation multiplier tube
Solid state scintillation detector
IONISATION CHAMBER
Here a chamber is filled with compressed gas. Two electrodes with high potential difference
between them is present. As the x–rays enter the chamber the atoms in the gas ionizes and current
flows between the electrodes and detection takes place. The advantages of the gas chamber is that it
is easier to manufacture and the response to beam density is linear.
SCINTILLATION MULTIPLIER TUBE.
Here a bismuth germinate crystal is used. When this crystal is struck by x–ray photon light is
produced with is proportional to the energy of the hitting photon. Near to this is a photo emissive
plane. The light produced from the crystal hits this plane and electrons are ejected from this plane.
The intensity of the ejected electrons depends on the

Crooks X-Ray History
The science behind the x–ray goes back to a chemist called Sir William Crooks. He was born June
17th 1832 in England. Crooks developed the Crooks Tube in 1870. This was an important invention
for scientists to come, among them was Wilhelm Roentgen who in 1895 was credited with the
discovery the x–ray. Back when the x–ray technique was new, people didn't realize the damage
radiation could cause. This changed soon when it was discovered how people were severely injured
from the exposure, as they were not wearing any protective shield. In the beginning the doctors or
physicists worked and operated the x–ray machines themselves, but as the demand grew, the need
for actual x–ray machine operators were needed. The Crooks tube, the discovery of the ... Show
more content on Helpwriting.net ...
One of the reasons could be the amount of time it took for an injury to occur after exposure.
However, more and more frequent cases describing skin irritation associated with a bad sunburn
started to occur. One scientist by the name of Elihu Thoms decided to expose his little finger under
radiation 30 minutes a day, for several days. The results were pain, swelling, erythema and
blistering. This convinced him, and others the dangers of radiation, and by 1900 the majority of the
medical and the scientific community, were familiar of the dangers of over exposure. The decrease
of exposure time and incidence was the most evident ways to limit the amount of radiation, or dose,
to a patient. They were even experimenting with enclosed tubes and distances to protect themselves
from the exposure. Filtration to the x ray beam was actually encouraged before the 1900's and so
was the size of the beam. Some other methods used to minimize patient exposure was using
intensifying screens and higher x–ray generating voltages. Even though ex–ray protection was well
known by 1905, it would still take many years for it to be universal. Even as late as the 1940's it was
not uncommon to find x–ray units without any safety measures at all. There are three distinctive
periods of radiation protection. The evolution of x–ray protection is split into three

Physics Of The Jsx 3222 Analyzer
The JSX–3222 analyzer is an energy–dispersive fluorescent X–ray spectrometer developed to
analyze cadmium (Cd) included in plastic and the electric wire film material, etc. promptly. The
elements range that can be measured is from sodium (Na) to uranium (U). Liquid–nitrogen cooling
for the high performance detector is needed only during the analyzing time. The vacuum and
atmosphere are switched to the measurement atmosphere by the one button operation. When X–rays
(primary X–rays) are illuminated from the X–ray tube to the specimen, fluorescence X–rays having
wavelengths (energies) peculiar to the constituent elements of the specimen are produced from the
elements.
There are two methods to investigate the energies. The first method is Qualitative analysis which
can be made by investigating the wavelengths of the fluorescence X–rays and the other method is
quantitative analysis by investigating the X–ray dose. One is for optical separation to them and the
other is to use the energy separation characteristic of the X–ray detector. The former is called the
wavelength dispersive method an: the latter the energy dispersive method. The element analyzer
employs the latter method. As seen from the figure, since the energy dispersive X–ray spectrometer
has no moving parts uses a simple optical system, its structure is simple and compact. And since the
detector can be installed the specimen, the X–ray solid angle of collection can be made large, thus
presenting many features such as

Radiation Vs Man Made Radiation
Radiation is the process of energy emitted through space. When people think of radiation the word
hazardous, threatening, and destructive comes to mind. However, people don't realize that there is
radiation emitted everywhere. There are two type of radiation: natural environmental and man–
made. Natural environmental radiation are occur throughout life because it's not something that can
be control. Examples of natural environmental radiation includes: the sun, stars, Earth and all earth–
based–concrete and bricks (Bushong p.). Man–made radiation are made by man such as in
diagnostic imaging system. The types of energy produce in radiation are electromagnetic energy
such as x–rays, gamma ray, radio waves, microwaves, ultraviolet, infrared, and visible light. Like
radiation these energies can be harmful depending on the intensity or power produced. For instance,
sunlight is a form of ultraviolet energy and are natural environmental radiation. There are many
benefits to sunlight it increase the levels of vitamin D, help enhance mood, energy and sleep.
However, too much sunlight can also be bad. It can cause sunburns, skin aging and cancer. Since
sunlight cannot be manipulate the only way to help regulate the amount of sunlight absorb is to use
sunscreen as a precaution. X–rays were discovered by Wilhelm Roentgen on November 8, 1895
with the Crookes tube. The X in x–ray stand for unknown. Roentgen took the first x–ray of his
wife's hand without any protection exposing

Essay About The History Of Chemistry

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