HAY – LOS NÚMEROS: Look at the report and answer the questions with in short sentences. (Write the numerals as words, use capital letter for the first word, and pay attention to the accent marks). Model:   ¿Cuántos chicos hay?                Hay cinco chicos.   Estudiantes en el Club de Español Actividades  1 número total de estudiantes: 21 Lecturas: 17 2 número de chicos: 5 Textos escritos: 23 3 número de chicas: 16 Profesores invitados: 9   1. ¿Cuántos estudiantes en total hay?

A nurse is educating a client who has HIV about the infection process. Which of the following features of the virus should the nurse explain can result in opportunistic infection?

Problem 1 (30 points) (a) (10 points) What are the basic components that are necessary to make a laser? Describe briefly the function of each component listed. (b) (5 points) Should you expect gas lasers at relatively low pressure to have emission spectral lineshapes that are dominated by homogeneous broadening or inhomogeneous (i.e. Doppler) broadening? Explain your reasoning. (c) (15 points) Q-switching (i) Qualitatively describe Q-switching and how it is used in laser systems. (ii) What are two methods of accomplishing Q-switching? (iii) What are typical pulse duration and peak power values for Q-switched lasers? Problem 2 (30 points) The L-Shaped Cavity of a Nd:YVO4 laser is shown below. Answer the following questions. Assume the cavity(except the Nd:YVO4 crystal) is filled with air. (a) (10 points) Calculate the free spectral range(FSRυ) for the cavity in MHz. (b) (5 points) For a light source at 532 nm what is the spacing (FSRλ , in terms of wavelength) between the longitudinal modes? (c) (5 points) What is the Finesse of the cavity? (d) (10 points) The gain medium above can be described by a four level system shown below. Sketch the approximate population densities (N2 and N1) for the given lifetime ratios and pump intensities. Provide a brief explanation explaining solution. You may sketch and label the population densities on the plot provided for each case. Initial population of states 1 and 2 can be assumed to be 0. State any additional assumptions you make, if required. Problem 3 (40 points) In the laser system shown below, only state 2 is pumped directly from the ground (or 0) state with a pumping value of R2 (cm-3/sec). State 2 decays to 0 at a rate of 5 x 106 sec-1 and to 1 by spontaneous emission (A21) and quenching collisions (k21) at a total rate (A21+k21) of 107 sec-1. The lifetime (τ1) of state 1 is 50ns. Assume homogeneous broadening; line width Δυ = 2  cm-1(= 60 GHz), λ= 400 nm; A21 = 106 sec-1; M= 40 x 1.67 x 10-27 kg; T=500K and that the medium fills the cavity in the manner shown below. Also assume steady state. (a) (10 points) What is the stimulated emission cross section at line center? (b) (10 points) Estimate the population inversion necessary to bring the laser to threshold? (c) (10 points) Write down the rate equations for the system described and calculate the steady state population densities N2 and N1. (d) (10 points) What is the pump rate needed to bring the laser to threshold?  (Hint: gi=2Ji+1) Congratulations, you are almost done with this exam.  DO NOT end the Honorlock session until you have submitted your work.  When you have answered all questions:  Use your smartphone to scan your answer sheet and save the scan as a PDF. Make sure your scan is clear and legible.  Submit your PDF as follows: Email your PDF to yourself or save it to the cloud (Google Drive, etc.).  Click this link to go to Gradescope: Final Exam Return to this window and click the button below to agree to the honor statement. Click Submit Quiz to end the exam.  End the Honorlock session. 

A nurse is providing care for multiple clients diagnosed with infections. Which of the following clients is at the greatest risk of sepsis?

What is wrong in the following statements about LDA

The Federal Highway Act of 1956 provided ___________________.

This war was started because Iraq invaded Kuwait.

This was a landmark case.  The U. S. Supreme Court ruled the Constitution guaranteed same-sex couples the fundamental right to marry.  What was the case?

Wallace stood at this university and promised to keep his campaign pledge of “segregation now, segregation tomorrow, segregation forever.”  The National Guard would be federalized, Wallace would step aside, and the students would be escorted in.  (In reality, Robert Kennedy made it know if Wallace caused to much trouble he would arrest him and lock him in the federal prison outside Atlanta.)

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