For cell culture, various laboratories use different volumes of culture medium in their culture flasks according to their conventions. However, many do not consider how this might affect the diffusion time of O2 from the gas/liquid interface to the cells attached to the bottom of the flask. To address this, it is useful to have an understanding of how the O2 diffusion time might be influences by the volume of medium added. A typical cell culture flask has a surface area available for cell attachment of 75 cm2 , therefore the height of medium, thus the diffusion distance will be a function of the volume of culture medium added. Cell culture is typically done at a temperature of 37 ºC. a) Calculate the diffusion time for O2 through culture medium from the gas/liquid interface if the height of medium (distance from the gas/liquid interface to the bottom of the culture dish) is 4 mm. Use the Einstein's approximation equation to determine your answer and cite the reference for the O2 diffusivity value you used in your calculations. b) Produce a plot of the O2 diffusion time as a function of culture medium volume for volumes in the range of 7 to 15 ml. c) If you wanted to standardize your laboratory’s practice in cell culture by keeping the height of culture medium the same (at 1.2 mm) for whatever vessels you use to culture cells, what volumes would be required for: - Standard round cell culture dishes with 35, 60, and 100 mm diameter. - For flasks, standard surface areas are 25, 75, and 175 cm2 . Show calculations for one of the conditions and present your results for all of the conditions in a table

Create a 1-page fact sheet that your healthcare organization could hypothetically use to explain the health or nursing informatics policy/regulation you selected. Your fact sheet should address the following:

• Briefly and generally explain the policy or regulation you selected.
• Address the impact of the policy or regulation you selected on system implementation.
• Address the impact of the policy or regulation you selected on clinical care, patient/provider interactions, and workflow.
• Highlight organizational policies and procedures that are/will be in place at your healthcare organization to address the policy or regulation you selected. Be specific.

Is there any trend between polymer structure and diffusion of a gas through the polymer? Rationalize your answer with 3 key points/facts/ideas.

Why are ceramics brittle? Can your answer also explain polymer behavior below its glass transition temperature? Why or why not?

(a) Derive Freundlich and Langmuir isotherm equations.

(b) An aqueous solution containing a valuable solute is colored by a small amount of an impurity. Before crystallization, the impurity is to be removed by adsorption on a decoloring carbon which adsorps only insignificant amount of the principal solute. Equilibrium data at constant temperature is as follows:

It is desired to reduce the color intensity to 10% of its original value (9.6)
(1) Find out Freundlich adsorption isotherm
(2) Determine the quantity of fresh carbon requirement per 100 kg of solution for a single stage operation.

"We are made of starstuff.”
― Carl Sagan, Cosmos

What did Carl Sagan mean when he made this famous statement? Write about your interpretation of this statement:

• Is it literal or figurative?
  • Make sure you use the proper dictionary definition of "literal" as people often use it to mean the exact opposite! Look it up if you aren't sure!
• Where did the material that Earth is made out of -- the silicon and carbon and iron and so forth -- come from?
• What implications does this have for life on planets around other stars, if there is any?

How do you perform adiabatic flash calculations?

Which of the following is NOT TRUE of Thomas Burnet’s 1684 book “The Theory of the Earth”?
A. Time was not constant, as suggested by Sir Isaac Newton
B. The water for Noah’s flood came from within the Earth
C. The Earth would end up as a star after the Day of Judgement
D. It encouraged an allegorical interpretation of Genesis

A water tower is being used to provide water to a subdivision. To ensure that it provides sufficient water pressure for the homes, fire hydrants, etc., it is built on top of a hill that, at an elevation 69.40 ft higher than the subdivision, hhill. The water in the tank is 55.70 ft deep, hwater, and the tower upon which it sits is 70.40 ft tall (htower), as shown in the figure below. The 12.200 in (inner diameter) pipe that conveys the water to the subdivision can be considered to have an effective length of 2.3600 mi, for the purposes of calculating friction losses. Friction loss can be assumed to vary with pipe velocity, v, by the following equation: ℱ = 0.01 L v2 / D What is the absolute pressure for the water delivered to the subdivision if the flow rate is to be 91,600 gph gallons per hour? (You can assume that the tank is open to the atmosphere and is kept completely full with water pumped into it from a nearby spring.)

choose one potential weapon from one of the chemical, biological, radiological or nuclear (CBRN) categories (i.e. you could select Tularemia, which could be a potential biological weapon). Write in your own words your assessment of your selected potential weapon's characteristics, accessibility, consequences of terrorists using that weapon based in researched facts. Please provide any support information required.

A fuel gas containing methane and ethane is burned with air in a furnace, producing a stack gas at 300 ° C and 105 kPa (absolute). You analyze the stack gas and find that it contains no unburned hydrocarbons, oxygen, or carbon monoxide. You also determine the dew-point temperature.

(a) Estimate the range of possible dew-point temperatures by determining the dew points when the feed is either pure methane or pure ethane.

(b) Estimate the fraction of the feed that is methane if the measured dew-point temperature is 59.5 ° C.

(c) What range of measured dew point temperatures would lead to calculated methane mole fractions within 5% of the value determined in Part (b)?

Problem 2: Theory

a. What are the factors that contribute to gaussian lineshape broadening in spectroscopy?

b. Is it possible to do XRD of a gold sample with a carbon Mα radiation?

c. What is the probing depth of a common lab XPS?

d. Write down the basic equation for photoemission from a solid, and explain the meaning of the terms.

e. What are the main differences between SEM and TEM? Enumerate at least three.

f. What is a fractal and why we can obtain fractal structures in the flame synthesis?