Air of 15 °c and 1.0 atm and is moving with a uniform velocity of 15.2 m/s and this flow is laminar. then, a thin sheet of naphthalene 0.254 cm thick and 10.2 cm square is placed in the air stream parallel to the direction of flow (air flows above and below the sheet). for how long, in hours, must the sheet be exposed to the air stream before one-tenth of its mass will have sublimed? assume the upper and lower surfaces remain flat at all times. the molecular diffusion coefficient for the air-naphthalene system is 185 cm2/h and the schmidt number is 2.57 under the conditions given in the problem. the vapor pressure of naphthalene at 15 °c is 0.0364 mmhg. neglect sublimation from the edges. the kinematic viscosity of air can be assumed to be 13.28 x 10-6 m2/s. the density of naphthalene is 1152 kg/m3. note: the transition to turbulent flow for this system occurs at rex = 3.0 x 105 so this should be checked

a, c, d, e are all applying about success strategies.

5 w for 1hr = 5x60x60 joules=300x60=3000x6=18,000j as total energy conversion. efficiency of bulb needed for radiant to thermal within 18000

electromagnetic shielding is the practice of reducing the electromagnetic field in a space by blocking the field with barriers made of conductive or magnetic materials. shielding is typically applied to enclosures to isolate electrical devices from their surroundings, and to cables to isolate wires from the environment through which the cable runs. electromagnetic shielding that blocks radio frequency electromagnetic radiation is also known as rf shielding.

the shielding can reduce the coupling of radio waves, electromagnetic fields and electrostatic fields. a conductive enclosure used to block electrostatic fields is also known as a faraday cage. the amount of reduction depends very much upon the material used, its thickness, the size of the shielded volume and the frequency of the fields of interest and the size, shape and orientation of apertures in a shield to an incident electromagnetic

from wikipedia