Science

12. How can A distinguish T from C? 13. Which DNA double helix do you think would be harder to separate into two strands: DNA composed predominantly of AT base pairs, or of GC base pairs? Why? 14. What is a mutation? -In 15. The DNA double helix looks like a twisted ladder. What makes up each rung of the ladder? What holds the rungs together at the sides? -Ea 16. Is there mostly empty space between the atoms in a DNA double helix?! 17. One base pair is not in position to form normal Watson-Crick hydrogen bonds. Can you find it? (Note: Clicking on any base in D. Ends, Antiparallelism reports its letter and sequence number at the bottom of the browser window in the status line, following the word “Group”. Use this feature to obtain the letters and sequence numbers of the abnormal base pair, once you find it.) -Instructions were to not answer this question. 18. How do proteins recognize specific sequences of DNA? -Proteins recognize specific sequences of DNA by Question Set C 19. Which bases are purines? Pyrimidines?

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EXPERT ANSWER 12. Nitrogenous bases are organic bases that are heterocyclic in nature and contain nitrogen. There are two types of nitrogenous bases, purines and pyrimidines. Adenine and Guanine are purines and cytosine, uracil and thymine are pyrimidines. Out of these nitrogenous bases, adenine, guanine, cytosine and thymine are found in the DNA and the …

12. How can A distinguish T from C? 13. Which DNA double helix do you think would be harder to separate into two strands: DNA composed predominantly of AT base pairs, or of GC base pairs? Why? 14. What is a mutation? -In 15. The DNA double helix looks like a twisted ladder. What makes up each rung of the ladder? What holds the rungs together at the sides? -Ea 16. Is there mostly empty space between the atoms in a DNA double helix?! 17. One base pair is not in position to form normal Watson-Crick hydrogen bonds. Can you find it? (Note: Clicking on any base in D. Ends, Antiparallelism reports its letter and sequence number at the bottom of the browser window in the status line, following the word “Group”. Use this feature to obtain the letters and sequence numbers of the abnormal base pair, once you find it.) -Instructions were to not answer this question. 18. How do proteins recognize specific sequences of DNA? -Proteins recognize specific sequences of DNA by Question Set C 19. Which bases are purines? Pyrimidines? Read More »

a) Calculate the polarization of a BaTi03 crystal (See the following Fig.). The structure transforms from cubic to tetragonal below the Curie point with lattice parameters c and conductivity to 4.06A and 3.97 A respectively. The displacement of titanium ion is opposite to that of oxygen ions. The magnitude of displacement is 0.06 A for titanium, 0.06 A for oxygen ions on the side faces and 0.08 A for oxygen ions on the top and bottom faces of the cube. The displacement of barium ions may be neglected.

Chemistry, Science / By

Question: a) Calculate the polarization of a BaTi03 crystal (See the following Fig.). The structure transforms from cubic to tetragonal below the Curie point with lattice parameters c and conductivity to 4.06A and 3.97 A respectively. The displacement of titanium ion is opposite to that of oxygen ions. The magnitude of displacement is 0.06 A …

a) Calculate the polarization of a BaTi03 crystal (See the following Fig.). The structure transforms from cubic to tetragonal below the Curie point with lattice parameters c and conductivity to 4.06A and 3.97 A respectively. The displacement of titanium ion is opposite to that of oxygen ions. The magnitude of displacement is 0.06 A for titanium, 0.06 A for oxygen ions on the side faces and 0.08 A for oxygen ions on the top and bottom faces of the cube. The displacement of barium ions may be neglected. Read More »

1. The diffusion rate of A in B was studied at 500°C and 850°C. It was reported that, for the same diffusion time, the depths of penetration xi and x2 in the two experiments were in the ratio of 1: 4. Show that the activation energy of A in B is 57 kJ/mol. 2. An amount Q of a dopant is deposited on the surface of a silicon substrate. During a subsequent anneal without the dopant in the atmosphere the concentration c of the donant as a function of depth x and time t is given by c= (0 VDI exp(-x2/4D Show that this is solution of Fick’s second law, where D is independent of concentration. 3. The activation barrier for iump is 100 kJ/mol. Calculate the rate at which a kacancy iumps in copper at 20°C.

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A lift with its occupants has a mass of 5000 kg . Calculate the tension in the elevator cable if it is: a) accelerated upward by 1.5 m/s 2 ; b) decelerated upward by 1.5 m/s2; c) accelerated downward by 1.5 m/s 2 ; d) decelerated downward by 1.5 m/s 2 . The spring of a cork gun has a spring constant of 20 N/m . A cork is shot horizontally from 10 m above the ground using this gun. How far the cork will travel before it hits the ground; ignore the air resistance in the calculation.

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4. (20 pts.) Below is a liquid-solid phase diagram for a mixture of two components, A and B. 300 750 p=1 700 liquid 650 600 $ 2550 500 450 400 40 350 300 0 01 02 03 04 05 06 07 08 09 1 . (a) For the points labeled through 4 along the vertical line at z = 0.2, provide the number of phases present, a description of each phase, and the mole fraction of B in each phase. (To receive full credit, your descriptions must be clear and unambiguous.) 1 (b) What is the melting temperature of pure A? (C) What is the melting temperature of pure B? (d) What is the eutectic temperature? (e) What is the eutectic composition? (1) What is the freezing point of a liquid with z=0.2?

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EXPERT ANSWER Ans) A) at point 1) – mixture at melting point At point 2)- A is solid and liquid At point 3)- mixture is at freezing point At poin 4)- mixture is solid Mole fraction of B at (z=0.2) = 0.2 B) – from graph we can see Melting point of pure A = …

4. (20 pts.) Below is a liquid-solid phase diagram for a mixture of two components, A and B. 300 750 p=1 700 liquid 650 600 $ 2550 500 450 400 40 350 300 0 01 02 03 04 05 06 07 08 09 1 . (a) For the points labeled through 4 along the vertical line at z = 0.2, provide the number of phases present, a description of each phase, and the mole fraction of B in each phase. (To receive full credit, your descriptions must be clear and unambiguous.) 1 (b) What is the melting temperature of pure A? (C) What is the melting temperature of pure B? (d) What is the eutectic temperature? (e) What is the eutectic composition? (1) What is the freezing point of a liquid with z=0.2? Read More »