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BASIC CONCEPTS. How much do you already know?. ????QUESTIONS???. MATTER Occupies_____________ is a material substance Has________and shape Building blocks of matter are_______and __________. ????QUESTIONS???. MATTER The primary characteristic of matter is _____________
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BASIC CONCEPTS How much do you already know?
????QUESTIONS??? • MATTER • Occupies_____________ • is a material substance • Has________and shape • Building blocks of matter are_______and __________.
????QUESTIONS??? • MATTER • The primary characteristic of matter is _____________ • Mass is the quantity or quality of an object? • ANSWER…QUANTITY • Does mass change when matter changes? • Give an example of a change of matter.
????QUESTIONS??? • WEIGHT • is the mass of matter in an object in ? • Why do we weigh less on the moon than on earth?
Types of energy (joules or eV) • Potential • Kinetic • Chemical • Electrical • Thermal • Nuclear • Electromagnetic
RADIATION • ENERGY EMITTED AND TRANSFERRED THROUGH SPACE • PIANO STRING=RADIATE SOUND • RIPPLES OR WAVES=WAVES RADIATE
IONIZING RADIATION(AGAIN!!!) • Removes orbital electron from atom • this electron can disrupt surrounding atoms by transferring energy to them. • This renegade(free) electron- negative ion • The atom that lost the electron- positive ion • negative ion & positive ion = ion pair
What two forms of electromagnetic radiation ionize matter? X-rays Gamma rays
What two particulate forms of radiation ionize matter? alpha beta
Natural Cosmic Terrestrial Naturally occurring radionucleides in the human body Manmade medical x-rays nuclear power plants industrial sources watch dials* smoke detectors* TV* Airport surveillance systems* SOURCES OF RADIATION HARMFUL TO HUMANS
DID YOU KNOW? • Naturally + man-made radiation occurring radiation contributes 360 mrads to the average absorbed dose to humans. • Diagnostic x-rays make up the largest source of man-made radiation (39 mrem per year-50 mrem per year)
EVOLVE • Module 1: Introduction to Radiographic Equipment • https://evolve.elsevier.com/cs/Satellite/StudentHome?Audience=Student • Homework • Section 2: Overview of Discovery and Use of X-Rays Quiz link.
IN THE EARLY YEARS OF USING X-RAYS • Skin damage (erythema) • loss of hair (alopecia) • low red blood cell counts(anemia) • INJURIES DUE TO • low energy radiation • looooonnnngggg exposure times (30 minutes!!!!!!!!!!!!!!!)
REDUCTION TO RADIATION EXPOSURE • Coolidge tube (Hot-cathode x-ray tube) • vacuum tube • intensity and energy to be selected (1913) Snook transformer High voltage power, induction coils (1910) Potter-bucky grid (1921)
PROTECTIVE APPAREL WAS DEVELOPED WHEN IT WAS NOTED THAT RADIOLOGISTS WERE DEVELOPING AT A HIGH RATE OF LEUKEMIA AND APLASTIC ANEMIA
Early blood changes decreased sperm count Latent cancer changes possible genetic effects Effects of radiation
REGULATION HISTORY • 1966- ICRP developed ALARA Radiation must have a benefit Dose should not exceed limits for specific circumstances
REGULATION HISTORY • 1987- NCRP established limits for radiation exposures for radiation workers and non-radiation workers limits were to minimize potential harm
DEVICES FOR MINIMIZING RADIATION TO PT/WORKER • Filtration • collimation • Intensifying screen • Protective barriers • Protective apparel • Technical factors (Highest optimal kVp, shortest time)
“The risk of radiation exposure in diagnostic imaging departments is minimal. Radiography is now considered a radiation safe occupation.”RADIOLOGIC SCIENCE FOR TECHNOLOGISTS,Stewart Bushong, 1997Page 7