ICLICKER QUESTION #0

Transcription

1 ICLICKER QUESTION #0 The online class evaluation web site < will close at what time? A) Friday Dec 9 th at midnight B) Monday Dec 12 th at midnight (last day of classes) C) Tuesday Dec 13 th at midnight (reading day) B D) Weds Dec 14 th at 8AM (first day of exams) E) Tuesday Dec 20 th at midnight (last day of exams) A C

2 Announcements Be sure to fill out the online course evaluations HW 13 is now due TUESDAY DEC 12 th, 8AM Today, we will also begin reviewing for the final exam PLUS a brief introduction to course material which I use in my B research. Yes, the material in this class IS useful. Recitation on Monday Dec 12 th will also be a review for final Solutions for Exams 1,2,3 posted on my web page Prof. Janow s Review will be Friday, December 16. C The session will last from 11:30 to 2:00pm. A

3 ICLICKER QUESTION #1 I have a conflict for our scheduled review on Monday (need to proctor another exam). The ption Review for the Final exam will be on MONDAY Dec 19 th at the following time: A) 8:30-11AM B) 2:30-5pm B C) None of these times are good, I would prefer a different day. A C

4 My research: (a) Electronic sensors fabricated by ink-jet printing technology. (b) Imaging and stand-off sensing using sub-millimeter wave radiation.

5 Background Based on Development over last ~ 4 years of ink-jet printable electronic components and devices Ink-jet Printing Technology using Commercial Printing System

6 Strain Sensor Strain sensor is ink-jet printed silver ink on top of a FLEXIBLE substrate Appling strain to the sensor/ substrate changes the length and area of the sensor. Since length and area change, RESISTANCE of sensor changes. Conceptually similar operation to SPRING. As spring stretches, force increases. As sensor is strained, resistance of sensor increases. Sensitivity (Gauge factor) of strain sensor determined by change in resistance per change in strain. gauge factor =(Δ % resistance/ Δ % strain) Measure strain (Δ L /L) by measuring change in resistance

7 Humidity Sensor Resistivity of materials may depend on many ambient properties Electrical resistance of humidity sensing polymer (polyaniline) increases as the humidity is increased. Electrodes:

8 New Ink-jet Printing Efforts RF-ID structures RF-ID structure is an LRC circuit. Measure resonance and resonance width of circuit by coupling to circuit using Mutual inductance, similar to concept of a metal detector. For an RF-ID sensor, design LRC circuit so that the measured resonance and/or resonance width depend on humidity, strain, pressure, etc.

9 Clicker Question #2 If you measure the E and B fields from a line of charge, which of the following statements are true? A) There is an E field present, but no B field. B) There is a B field present, but no E field C) B and E fields are both zero D) There is definitely a E field present, and there may be a B field depending on the motion of the observer. E) There is definitely a B field present, and there may be a E C field depending on the motion of the observer.

10 E If line of charge NOT MOVING, Then E field only is present If line of charge MOVING, B field also present due to current E. CURRENT X B

11 E and B fields must be intimately coupled. What is missing from the equations below? E da Q o E dl d dt B da B da 0 B dl I o C

12 Time varying Electric fields give rise to Magnetic Fields E da Q B da 0 o E dl d dt B dl I Let there be light! o ( o B da d dt EdA) Displacement current Real current

13 Collectively those equations are called Maxwell s equations. But he only contributed one term! c 1 o o

14 What is Terahertz (THz)? Visible Radio Microwave T-rays Infrared UV X-rays Frequency (Hz) 1 THz frequency = 300 m wavelength or 33 cm -1 or 4.1 mev or T = 48 K Also known as Far-Infrared or sub-millimeter D. Mittleman, Sensing with THz Radiation

15 Brijot Passive Millimeter Wave

16 THz Detection of Weapons in Packages Sealed Package Non-metallic Weapons Easily Detected D. Zimdars, Proc. SPIE 5070 (2003)

17 Example of Close Proximity (<3m) THz imaging Single THz Scan of Bag Captures All Depths 3D Imaging XM05 Gun Surface Top Pockets Deep Interior Knife

18 Natural Cork Natural Cork comes from Cork Oak (Quercus suber) grown predominately in Mediterranean Sea coastal areas. Cork is an excellent enclosure for wine: Honeycomb structure of cells: Compressible, barrier to movement of liquid and gas.

19 Classification of Corks TYPE A - These are corks with top quality visual appearance - excellent surfaces, with no major visual flaws and few small ones. No holes or pores which exceed 2mm. No cracks originating at the ends which exceed 11% of cork length. No cracks in the body of the cork to exceed 18% of cork length. All cracks must be tight and not open. No horizontal cracks. No worm holes, hardwood, belly spots, or greenwood. Several narrow and shallow lenticels are acceptable if they are free of dust and particles. Type A Type B Type C

20 THz NDE of Cork THz reveals hidden cracks/ voids/ and Defects

21 Latest Results Cork Internal Structure Cork Long Axis Top of Cork Defects Rotation Angle (degrees) Average Transmission THz

22 Cork with Defect 180 o 90 o y x 270 o 0 o 0 o 90 o 180 o 270 o 3-D THz Tomography Image reveals large internal defect

23 Corks with similar outward Appearance show DIFFERENT internal structure Note transparency of cork on left compared to right