Lecture Notes PHY 4502 Week 1 PDF

Types of far infrared use in EXERCISE & Fitness 1.Far-Infrared Emitting 2. Far-Infrared Emitting 3. INFRARED 5. FAR infrared textile Bioceramic long suits BIOCERAMIC PANTS SAUNA...

Types of far infrared use in EXERCISE & Fitness 1.Far-Infrared Emitting 2. Far-Infrared Emitting 3. INFRARED 5. FAR infrared textile Bioceramic long suits BIOCERAMIC PANTS SAUNA Spectrally Selective Nanocomposite Textile (upper + lower body) maximal eccentric exercise + Postural stability USING Far-Infrared Emitting + Postural control Ceramic Materials would improve neuromuscular performance, By reflecting > 90% solar irradiance BY transmitting out by increasing tissue elasticity human body thermal radiation biochemical and perceptual markers and reducing stiffness uses infrared light FOR: can enable simulated skin to avoid overheating by 5–13 °C Felipe, R., ET AL 2019 compared to normal textile (cotton) under peak daylight CIAN et al.2015 1.MUSCLE RECOVERY 2.PAIN RECOVERY condition. BY improves blood circulation, more Cai L. et al 2018 4. Graphene Heating Device oxygen and nutrients to get to the muscle tissue Noponen et al 2015 Fatigue Recovery of Biceps Brachii LIU W ET AL 2023 Learning Objective: Understanding Radioactivity and Ionizing Radiation By the end of this lecture, you will be able to explain the principles of radioactivity and the different types of ionizing radiation, including their properties and applications in various fields. Success Criteria: 1.Define Key Terms: Accurately define radioactivity, ionizing radiation, alpha particles, beta particles, and gamma rays. 2.Identify Types of Radiation: Classify examples of ionizing radiation and describe their unique properties, including penetration power and ionization ability. 3.Analyze Radiation Sources: Evaluate the sources of ionizing radiation in the environment and their potential health effects. 4.Demonstrate Knowledge Utilization: Apply knowledge of radiation properties to real-world scenarios, such as medical imaging and radiation therapy. Characteristic X-ray Results from electronic transitions Gamma ray between atomic shells. Results from nuclear transitions. Ionizing Radiation Bremsstrahlung Annihilation quantum (annihilation radiation) Results mainly from electron-nucleus Coulomb. Results from positron-electron annihilation. What are the key words you think can easily help you compare direct/indirect ionizing radiation?  Atomic and Nuclear Structure Basic Definitions for atomic structure For example: Cobalt-60 nucleus with Z = 27 protons and A = 33 neutrons is identified as. Radium-226 nucleus with 88 protons and 138 neutrons is identified as. Hai, We are Isotope! Do you remember us? Nice to meet you! We are Isotones! And we are Isobars! Radioactivity? What is it?  Radioactivity Property of some atoms that cause them to spontaneously give off energy as particles or rays. Radioactive atoms emits ionizing radiation when they decay. What are these radioactive elements? Radioactive elements which contain a nucleus that is unstable. The unstable nucleus is in excited state that can not be sustained indefinitely. It must relax or decay, to a more stable configuration.  The Nature of Radiation The energy emitted by an unstable nucleus comes packaged in very specific forms. Radiation consisted of 3 types: alpha (α), beta (β) and gamma (γ) radiations. Radiation emitted transforms the elements into new elements. This process is called decay or disintegration. Nature of the Radiation from Radioactive Sources Alpha-decay Beta-decay Gamma-decay  Alpha (α-decay) Nuclear process in which parent nucleus transformed to daughter nucleus with a decrease in atomic number, from Z to Z-2 and mass number from A to A-4 and ejected monoenergetic α-particle.  Beta (β-decay) Radioactive process in which a neutron-rich parent nucleus decay to a daughter nucleus with an increase in atomic number, from Z to Z + 1 in case of β− decay and Z to Z – 1 in case of β+ decay. Let’s try again!!  Gamma (γ-decay) Gamma decay is a radioactive nucleus undergoes nuclear deexcitation with the emission of γ-rays of energy from few to several MeV. Half-life  Half-life Half-life →a pile of cookies that disappear over time. Cookies = radioactive atoms Disappearance = decay of radioactive atoms Half-life = the time it takes for half of the cookies to disappear Imagine you have a jar with 100 cookies. Every hour, half of the cookies disappear (get eaten). After the first hour, you’d have 50 cookies left. After the second hour, 25 cookies remain, and so on. The key idea is that with each passing hour (the half-life), half of whatever is left disappears.  Half-life (T1/2) A radioactive source consists of a large number of unstable atoms. All these atoms sooner or later emit radiation, but these emission do not take place simultaneously. It is a statistical process, with one atom decaying every now and then.. When one half of the atoms have decayed the source has gone through what is called one “half-life”. After an additional half-life, ¼ of the atoms remain.  Half-life (T1/2) Time required for an amount of any radionuclide to decay to one-half of its initial value. 𝑙𝑛2 T1/2 = 𝜆 Amount of activity ‘N’ remaining after ‘n’ half life given: 𝑁 1 = 𝑛 𝑁0 2  Half-life (T1/2) A radioactive half-life refers to the amount of time it takes for half of the original isotope to decay. For example, if the half-life of a 50.0 g sample is 3 years, then in 3 years only 25 g would remain. During the next 3 years, 12.5 grams would remain and so on. Mean life Average life of radioisotopes. Tm = 1.44 T1/2 Unit Amount of radionuclide present. SI unit : Becquerel (Bq) 1 Bq = 1 disintegration per second Other unit: Curie (Ci) 1 Ci = 3.7 x 1010 Bq Decay constant (λ) SI unit: 𝑠𝑒𝑐 −1 A=λN Where N is number of elements. Radioactive Decay Equations 𝑑𝑁 = - λ N (t) 𝑑𝑡 N (t) = N0𝑒 −λ N (t) A (t) = A 0𝑒 −λ N (t)  Quick Quiz I am invisible and can’t be felt, yet I can change your cells and how they melt. What am I? Answer: I can help cure, but I can also harm, I come from atoms and can cause alarm. What am I? Answer:  Incident of Radiation History (Activity) 30 Min Your task: Find information Talk related to 1) The incident- when, where, who, why, how 2) Sources of radioactive elements involve CHERNOBYL 3) Half-life for all radioactive elements involved in the incident 4) Why do you think people can repopulate/ resettle Hiroshima and Nagasaki after the incident but not for Chernobyl? 5) Why do you think people cannot repopulate/ resettle after the incident for HIROSHIMA & NAGASAKI Chernobyl?