## Calculate the mass of helium lost by diffusion. D = 0.04 × 10–12 m2/s. The solubility of helium in the material = 1.8 × 10–3 kg/m3 bar.

In problem 14.18 if the shape of the container is a long cylinder of the same diameter, determine the loss for 1 m length.

Problem 14.18

Helium gas at a pressure of 6.2 bar is stored in a fused silica container of spherical shape of 0.21 m diameter, the wall thickness being 2.6 mm. Calculate the mass of helium lost by diffusion. D = 0.04 × 10–12 m2/s. The solubility of helium in the material = 1.8 × 10–3 kg/m3 bar.

### design suitable bearings to support the load for at least 5E8 cycles at 1 200 rpm using deepgroove ball bearings.

The shaft shown in Figure P11-4 was designed in Problem 10-19. For the data in row (a) of Table P11-1, and the corresponding diameter of shaft found in Problem 10-19,….

### Find the minimum film thickness for a long bearing with the following data: 30-mm dia, 130 mm long, 0.0015 clearance ratio, 1 500 rpm, ISO VG 100 oil at 200°F, and supporting a load of 7 kN.

1.       A paper machine processes rolls of paper having a density of 984 kg/m3. The paper roll is 1.50-m OD X 22-cm ID X 3.23-m long and is on a simply supported, 22-cm OD, steel….

### Find the minimum film thickness for a bearing with these data: 30-mm dia, 25 mm long, 0.0015 clearance ratio, 1 500 rpm, ON = 30, ISO VG 220 oil at 200°F.

1.       Problem 7-12 estimated the volume of adhesive wear to expect from a steel shaft of 40 mm dia rotating at 250 rpm for 10 years in a plain bronze….