All stars start by burning hydrogen and end up creating many heavier elements inside their cores. It is this kind of star that will eventually spread the elements it created in its core when it dies in a supernova explosion.
Engagement Using colored clay, either home-made or store-bought, make a model of the core of a star. If time allows, the class can do this themselves, otherwise, the teacher can demonstrate it for the class. Materials: 8 colors of clay, either home-made or store-bought see recipe for home-made clay ball-bearing or other small metallic ball large silver beads would work plastic knife Procedure: Cover the ball-bearing or bead with one color of clay - make the layer of clay at least half an inch thick.
Use another color of clay to make a layer over the first. Do this until you have 8 layers of clay, each a different color, each at least half an inch thick. Now, cut the ball in half to make a cross section you'll have to cut around the ball-bearing. The inside shows the different layers present in the core of a high-mass star. Each of those layers of clay belongs to a different element. The ball-bearing is the iron core of the star. At the end of the day's activity, the class will come back to the model and learn what the different layers are.
Exploration Materials: Index cards with elements written on them. Have the students move about the classroom and construct fusion reactions. Their goal is to form the reactions that create helium , carbon, magnesium, oxygen, sulphur, neon, nickel, cobalt, and 4 different isotopes of iron. They should be performed only when the referring physician judges them to be necessary to answer a clinical question or to guide treatment of a disease.
Asking the referring physician about the benefits and risks of imaging procedures, such as: How will the results of the exam be used to evaluate my condition or guide my treatment or that of my child? Asking the imaging facility: If it uses techniques to reduce radiation dose, especially to sensitive populations such as children. About any additional steps that may be necessary to perform the imaging study e.
Principles of radiation protection: justification and optimization Justification: The imaging procedure should be judged to do more good e. Therefore, all examinations using ionizing radiation should be performed only when necessary to answer a medical question, treat a disease, or guide a procedure. The technique factors used should be chosen based on the clinical indication, patient size, and anatomical area scanned; and the equipment should be properly maintained and tested.
While the referring physician has the primary responsibility for justification and the imaging team e. Imaging teams e. Develop protocols and technique charts or use those available on the equipment that optimize exposure for a given clinical task and patient group see also the Pediatric X-ray Imaging webpage. Implement regular quality control tests to ensure that equipment is functioning properly. Assure appropriate credentials and training emphasizing coverage of radiation safety for medical personnel using X-ray imaging equipment.
Ensure that the principles of radiation protection are incorporated into the facility's overall quality assurance program.
Clinicians can manage justification through the use of evidence-based referral criteria to select the most appropriate imaging procedure for the particular symptoms or medical condition of a patient. Information for the imaging team Patient radiation dose is considered to be optimized when images of adequate quality for the desired clinical task are produced with the lowest amount of radiation considered to be reasonably necessary.
Reviews can be based on practice trends over time, equipment operator or medical practitioner performance, or authoritatively established dose-index values associated with the most common exams and procedures.
For a particular medical -imaging task and patient size group, a DR is typically set at the 75th percentile third quartile of the distribution of dose-index values associated with clinical practice. Eisenstein, Health Physics Vol. Electronic Product Radiation Control EPIC requirements for manufacturers and assemblers Manufacturers and assemblers of electronic radiation-emitting products sold in the United States are responsible for compliance with the radiological health regulations found in Title 21 of the Code of Federal Regulations Subchapter J, Radiological Health.
Your rating: None Average: 3. Application Parental rating:. Default language:. Trial version:. With advertisements:. Requires third-party libraries:. Requires 'rooted' device:. Minimum Android version:. Minimum screen width:. Requires features:. Requires permissions:. Reviews of X-Ray Camera Free 4. Read more.
0コメント