# How do you calculate specific nuclear activity?

## How do you calculate specific nuclear activity?

Activity – Specific Activity

1. Units of activity (the curie and the becquerel) can be also used to characterize an overall quantity of controlled or accidental releases of radioactive atoms.
2. Units of Activity.
3. Decay Law.
4. (Number of nuclei) N = N.e-λt (Activity) A = A.e-λt (Mass) m = m.e-λt

## What is the half-life of iodine-129?

(Isotopes are different forms of an element that have the same number of protons in the nucleus but a different number of neutrons.) Iodine-129 decays by emitting a beta particle with a half-life of about 16 million years; the half-lives of all other iodine radionuclides are less than 60 days.

Is iodine-129 naturally occurring?

Iodine-129 is naturally occurring in the environment, and it has also been produced by nuclear weapons testing.

How is iodine-129 produced?

Both iodine-129 and iodine-131 are produced by the fission of uranium atoms during operation of nuclear reactors and by plutonium (or uranium) in the detonation of nuclear weapons.

### How do I calculate specific activity?

In summary, specific activity = enzyme units / (vol. in µl x (protein conc. in mg per ml / 1000))

### How do you calculate specific activity from absorbance?

You need to correlate the absorbance of the product released in your assay with standard product curve. By using y=mx+c, from your (Standard curve) you need to check the concentration of product released in term of micro gram. After identifying the amount of product release, then you can calculate Enzyme activity.

How long does it take for the activity a sample of 131I to drop to 95% of its initial value the half-life of 131I is 8.02 days?

(a) As the half life of 131I is only 8.02 days, after 3 months most of it will have decayed. As the half life of 137Cs is 30.17 years, after 3 months little will have decay.

How does I-131 decay?

Iodine-131 has a half-life of 8.06 days and decays by beta-particle emission to a stable 131Xe.

## How is xenon 129 produced?

Xe is produced by beta decay of 129I (half-life: 16 million years); 131mXe, 133Xe, 133mXe, and 135Xe are some of the fission products of both 235U and 239Pu, so are used as indicators of nuclear explosions. I will have had time to decay to Xenon before the explosion of the bomb removes it from the neutron radiation.

## What is the half-life of Tc 99m?

Molybdenum-99, with a half-life of 65.94 hours, decays into technetium -99 through beta decay.

What is the half-life of iodine?

Iodine-131’s short half-life of 8 days means that it will decay away completely in a matter of months. Most I-129 in the environment came from nuclear weapons testing. Atmospheric testing in the 1950s and 60s released radioactive iodine to the atmosphere.

What is specific activity and how can it be measured?

Specific activity is equal to the enzyme activity divided by the mass of the total enzyme. Therefore, the common unit of the specific activity is μmol min−1 mg−1. The SI unit is katal/kg. The amount of active enzyme in the mixture can be determined by an active site titration.

### How do you calculate specific activity?

As specific activity is units of enzyme per mg protein, first calculate the mg protein in the sample. The sample volumes are in µl, whereas the protein concentration is in mg/ml, so you need to divide the latter by 1000 to get mg/µl. Then multiply by the volume in µl to get the number of mg protein in the sample.

### How do you calculate total activity and specific activity?

1. total activity = (specific activity) x (total mg protein in preparation)
2. % yield – the amount of protein of interest retained in the purified fraction.

What is the half-life of iodine-131 if after 24 days?

The half-life of iodine-131 is 8 days. Since the half-life is 8 days, 24 days corresponds to 3 half-lives. After one half-life 5 mg are left; after two half-lives, 2.5 mg; and after 3 half-lives 1.25 mg remain. thyroid.

What is a period of stay documented on Form I-129?

When the beneficiary with an approved Form I-129 is admitted to the United States, U.S. Customs and Border Protection grants the beneficiary a period of stay documented on Form I-94 or as noted in the passport or travel document.

## Can I submit this checklist with my I-129 form?

Please do not submit this checklist with your I-129. It is an optional tool to use as you prepare your form, but does not replace statutory, regulatory, and form instruction requirements.

## How much is the Premium Processing Fee for Form I-129?

The premium processing fee for petitioners filing Form I-129 requesting H-2B or R-1 nonimmigrant status is increasing from \$1,440 to \$1,500. Any Form I-907 postmarked on or after Oct. 19 must include the new fee amounts. Read more here: Premium Processing Fee Increase Effective Oct. 19, 2020.

How do I file I-129 in California with CNMI?

When completing Form I-129, please list your CNMI P.O. box when asked for a street or physical address. File your petitions for employment or services in the CNMI, regardless of classification, with the California Service Center.