a) Define the following terms: (i) ferroelectric (ii) piezoelectric

b)Draw perspective and plan views of the unit cell of cubic barium titanate. Label the fractional co-ordinates of the non-equivalent ions and state the co-ordination number of the ions. [6 marks] (ii) Describe, with the aid of appropriate diagrams, the various structural changes which occur as a barium titanate crystal cools from 200°C to -100°C. Specify the temperatures of the relevant phase transitions.

The elementary irreversible gas phase reaction A --> B + C is carried out in a PFR packed with catalyst. Pure A enters the reactor at a volumetric flowrate of 20 dm³ /s at a pressure of 10 atm and 450K.

C_pA=40 J/mol.K H_fA=-70 kJ/mol   (T_R=273 K)

C_pB=25 J/mol.K H_fB=-50 kJ/mol

C_pC=15 J/mol.K H_fC=-40 kJ/mol

k = 0.133 exp ( E/R*[ 1/450 ? 1/T ] ) dm³ kg cat. s with E = 31.4 kJ/mol

a) Plot the conversion and temperature down the plug flow reactor until 80% conversion is achieved.

b) Calculate the amount of catalyst required to achieve 80% conversion.

Explain Step by step how to do the standard design procedure for a heat exchanger and how to critically assess the shortcomings of using a certain method.

What is the maximum concentration of carbon possible in the FCC phase of iron before causing precipitation of either Fe3C or liquid? At what temperature is the carbon solubility in FCC iron a maximum?

This problem is related to bioprocess engineering. There is a problem named 'Lysine project'

There are some conditions for this problem:

•Annual capacity of lysine production: 100,000 ton

(each bioreactor volume < 100 m³)

- Microbial host: Corynebacterium

- Lysine productivity: 2 g lysine l-1 hr-1

- Cell respiration rate q_o2: 20 mmol O2 gDW-1 hr-1

- Cell concentration: 10 gDW l-1

- Dissolved oxygen concentration setting value: 2 mg O2 l-1

- Saturated dissolved oxygen concentration: 8 mg O2 l-1

I solve these tasks from above conditons(Result values should show exact number):

•Sizing of bioreactor

(Diameter, height, baffle etc.)

•Agitator type, agitator size

•Agitator operation condition: rotation speed (rpm)

•Aeration flow rate

What is meant by the term ‘sacrificial anode’? Use diagrams and/or equations to illustrate your answer.

Chemistry 252 has focused on two main topics: the nature of the equilibrium state, and the rates of processes that take place to achieve equilibrium, i.e., chemical kinetics.

Write a paragraph that compares the information content required to describe the equilibrium state with that necessary to describe the rate processes that connect reactants and products.   In your answer, include a discussion of the energy levels, molecular motions, and appropriate length scales of all important species involved in specifying the equilibrium state. Include a similar discussion for any key species that play a role in the reaction rates that establish equilibrium.   Indicate how the properties of these species are incorporated into a theory of reaction rates.

Topics that may be helpful in constructing your answer:

             Potential energy surface

             Reaction coordinate

             Partition functions    

             Transition state

             Saddle point

Your paragraph should be written in acceptable scientific prose. You should use complete sentences, and the logical flow of your arguments should be clear. There is no word limit, but preferably no longer than a page typed.

You are watching TV late at night and see an ad for the ACME Model #163 refrigeration and heating unit for only $99.99. The unit takes compressed air at 1.25 atm pressure and 75°F and produces two streams at atmospheric pressure, a refrigeration stream at -15°F and one at 90°F with no work or energy put into the system! Is this possible? [yes] Why or why not? [mass and energy balance work ] Prove your answer. Assume air is an ideal gas

Air Date: Tc = 238.5 R Pc = 37.2 atm Cp = 7 Btu/lbmole°F Sp. Gr. = 1.0

Answers are in brackets but I want to know why because I am a diligent student. lol.

Does isoctane/n octane mixture follow roults law?

Why do the Au NPs grow in the subsequent steps rather than just form more particles of the same initial size? ?

How does the gold colloid detect electrolytes such as NaCl? Explain what happens when NaCl is added to the solution?

How to convert wave function to matrix in H2 and LiH . And how to find the determinant(energy)?