In an IR detector, the sensor housing is held at 80 K by a mechanical cooler. The sensor is mounted to a frame that runs at 200 K by four thin walled hollow tubes that are 5.08 cm long by 1.27 cm outer diameter. The total heat leak through the four tubes into the detector has to be kept at less than 200 mW. Assuming G-10 (0.5 W/m-k) is used, find the wall thickness for the tube required to meet the heat leak condition. What if 6061-T6 (167.1 W/m-k) aluminum is used instead

Asingle-geared blanking press has a stroke of 200 mm and a rated capacity of 320 kn. a cam driven ram is assumed to be capable of delivering the full press load at constant force during the last 15 percent of a constant-velocity stroke. the camshaft has an average speed of 90 rev/min and is geared to the flywheel shaft at a 6: 1 ratio. the total work done is to include an allowance of 16 percent for friction a) estimate the maximum energy fluctuation b) find the rim weight for an effective diameter of 1.2 m and a coefficient of speed fluctuation of 0.10

Compute the pressure drop of 30°c air flowing with a mean velocity of 8 m/s in a circular sheet-metal duct 300 mm in diameter and 15 m long. use a friction factor, f 0.02, and pair = 1.1644 kg/m a. 37.26 pa b. 25.27 pa n c. 29.34 pa d. 30.52 pa

The short distance from the objective lens to the object causes problems at high magnification. which of the following is the most serious? a. cleaning the object surface b. positioning the object c. reflection from the object surface. d. illumination of the object