Assignment: Homework: Fricke dosimetrist solution
1. Calculate the dose rate and the absorbed dose for the Fricke dosimetric solution that was irradiated with Co-60 source during 3 hrs. The absorbance of the irradiated dosimetric solution (Fe3+), measured with UV/Vis-spectrophotometer in 1 cm cuvettes at the wavelength =304 nm, increased from 0.01 (initial) to 0.203 (irradiated). The molar absorptivity of ferric ions for this wavelength is ε304 = 2187 L mol1cm1, the density of the dosimetric solution is ρ=1.024 g/mL, and the tabulated radiation chemical yield for gamma source 60Co is 1.6 µmol J1.
A = εcl
2. Calculate the dose rate and the absorbed dose for the ceric sulfate dosimetric solution that was irradiated with Co-60 source during 3 hrs. The absorbance of the irradiated dosimetric solution (Ce4+), measured with UV/Vis-spectrophotometer in 1 cm cuvettes at the wavelength =320 nm, decreased from 1.01 (initial) to 0.21 (irradiated). The molar absorptivity of ceric ions for this wavelength is ε320 = 561 L mol1cm1, density of the dosimetric solution is ρ=1.025 g/mL and the G value for the cerous-ion yield is 2.3 molecules/100 eV for the gamma source 60Co.
3. Estimate the effect of alpha-autoradiolysis in the acidic aqueous solution of 239Pu with concentration of 0.03 mol/L of 239Pu:
a) Considering the half-life T1/2=24111 y (=7.60364×1011 sec) and the alpha energy of 5.24 MeV, what is the weekly dose absorbed in 1L solution? E(alpha/Pu) = 5.24 MeV x 1.602.10-19 J/eV = 8.395×10-13 J
b) The plutonium is originally in its hexavalent state, but is reduced to its tetravalent state (then precipitated) by the reaction with hydrogen radicals. If the radiation yield of hydrogen radicals is 0.2 umol/J, how much Pu(VI) is reduced in one week? Hint: [Pu6+ + 2H* = Pu4+ +2H+]
4. The count rates listed in the table below were measured for a mixture of two genetically independent radionuclides. Both radionuclides are beta- emitters, and they both precipitate in the solution of AgNO3. Identify the unknown radionuclides in the measured mixture, and calculate their initial activity (DE = 40%). Recall that precipitating of both the unknown radionuclides with silver nitrate indicates that both unknown elements are halogens.
The concentrations of colored solution are usually determined spectrophotometrically. Method is based on the Lambert-Beer law, which binds the absorbance A (decrease of the light beam intensity) with the molar concentration of the analyte C, its molar absorptivity ε (constant at given wavelength) and the length of the light path (thickness of the cuvette with measured liquid):
A = ε.c.l
Important information for writing discussion questions and participation
Please read through the following information on writing a Discussion question response and participation posts.
Contact me if you have any questions.
Important information on Writing a Discussion Question
- Your response needs to be a minimum of 150 words (not including your list of references)
- There needs to be at least TWO references with ONE being a peer reviewed professional journal article.
- Include in-text citations in your response
- Do not include quotes—instead summarize and paraphrase the information
- Follow APA-7th edition
- Points will be deducted if the above is not followed
Participation –replies to your classmates or instructor
- A minimum of 6 responses per week, on at least 3 days of the week.
- Each response needs at least ONE reference with citations—best if it is a peer reviewed journal article
- Each response needs to be at least 75 words in length (does not include your list of references)
- Responses need to be substantive by bringing information to the discussion or further enhance the discussion. Responses of “I agree” or “great post” does not count for the word count.
- Follow APA 7th edition
- Points will be deducted if the above is not followed
- Remember to use and follow APA-7th edition for all weekly assignments, discussion questions, and participation points.
- Here are some helpful links
- Student paper example
- Citing Sources
- The Writing Center is a great resource
Welcome to class
Hello class and welcome to the class and I will be your instructor for this course. This is a -week course and requires a lot of time commitment, organization, and a high level of dedication. Please use the class syllabus to guide you through all the assignments required for the course. I have also attached the classroom policies to this announcement to know your expectations for this course. Please review this document carefully and ask me any questions if you do. You could email me at any time or send me a message via the “message” icon in halo if you need to contact me. I check my email regularly, so you should get a response within 24 hours. If you have not heard from me within 24 hours and need to contact me urgently, please send a follow up text to.
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Plagiarism is highly prohibited. Please ensure you are citing your sources correctly using APA 7th edition. All assignments including discussion posts should be formatted in APA with the appropriate spacing, font, margin, and indents. Any papers not well formatted would be returned back to you, hence, I advise you review APA formatting style. I have attached a sample paper in APA format and will also post sample discussion responses in subsequent announcements.
Your initial discussion post should be a minimum of 200 words and response posts should be a minimum of 150 words. Be advised that I grade based on quality and not necessarily the number of words you post. A minimum of TWO references should be used for your initial post. For your response post, you do not need references as personal experiences would count as response posts. If you however cite anything from the literature for your response post, it is required that you cite your reference. You should include a minimum of THREE references for papers in this course. Please note that references should be no more than 5 years old except recommended as a resource for the class. Furthermore, for each discussion board question, you need ONE initial substantive response and TWO substantive responses to either your classmates or your instructor for a total of THREE responses. There are TWO discussion questions each week, hence, you need a total minimum of SIX discussion posts for each week. I usually post a discussion question each week. You could also respond to these as it would count towards your required SIX discussion posts for the week.
I understand this is a lot of information to cover in 5 weeks, however, the Bible says in Philippians 4:13 that we can do all things through Christ that strengthens us. Even in times like this, we are encouraged by God’s word that we have that ability in us to succeed with His strength. I pray that each and every one of you receives strength for this course and life generally as we navigate through this pandemic that is shaking our world today. Relax and enjoy the course!