Circular hole

Figure fl.11 An aluminum cooling water conduit severely attacked by a caustic in service. The large circular hole in the machined face is corroded around its edges. The elliptical hole between the 6- and 7-in. ruler markings was formed by corrosion penetrating the conduit wall. 

The column takes the form of a circular hole round the wheel circumference and there... 

For small-scale laboratory work, the exhaust surface is often made as a separate section added to the side of a table or put into a large hole in a table. These tables usually have a sheet metal surface that is resistant to the chemicals used and is easily cleaned. Many circular holes are cut into the metal surface to allow for airflow. This perforation makes the pressure difference over the table quite high and at the same time gives an even distribution of the airflow over the entire surface. These types of exhaust surfaces could be formed to suit different working conditions, e.g., the surface could be made to fit into a sink or to be placed below and around a balance. Using side walls that are not too high, on three or four sides, transforms the table to a partial enclosure, which increases... 

Figure 6-6 Effect of Material Properties on Circumferential Stress Gq at the Edge of a Circular Hole in an Orthotropic Plate under a, (After Greszczuk [6-11])...

The second special case is an orthotropic lamina loaded at angle a to the fiber direction. Such a situation is effectively an anisotropic lamina under load. Stress concentration factors for boron-epoxy were obtained by Greszczuk [6-11] in Figure 6-7. There, the circumferential stress around the edge of the circular hole is plotted versus angular position around the hole. The circumferential stress is normalized by a , the applied stress. The results for a = 0° are, of course, identical to those in Figure 6-6. As a approaches 90°, the peak stress concentration factor decreases and shifts location around the hole. However, as shown, the combined stress state at failure, upon application of a failure criterion, always occurs near 0 = 90°. Thus, the analysis of failure due to stress concentrations around holes in a lamina is quite involved. 

Figure 6-7 Stress Concentration at the Edge of a Circular Hole in...

The stress-intensity factors are quite different from stress concentration factors. For the same circular hole, the stress concentration factor is 3 under uniaxial tension, 2 under biaxiai tension, and 4 under pure shear. Thus, the stress concentration factor, which is a single scalar parameter, cannot characterize the stress state, a second-order tensor. However, the stress-intensity factor exists in all stress components, so is a useful concept in stress-type fracture processes. For example. 

The bottom of the unit is composed of multiple sections of sand filter [11] and clearwell [12], The clarified flotation effluent passes through the sand filter downward and enters the clearwell through the circular hole underneath each sand filter section the filter effluent then enters the center portion of the clearwell where there is an outlet for the effluent.13... 

Figure 3.7 An anti-smoking device the cigarette is inserted into the wider end. Partially oxidized carbon monoxide combines chemically with oxygen inside the device after leaving the end of the cigarette but before entering the smoker s mouth the oxygen necessary to effect this oxidation enters the device through the small circular holes positioned along its length...

This work was done in collaboration with Professor Hiroshi Yoneyama of Osaka University [124], The procedure used to prepare the LiMu204 tubules is shown schematically in Fig. 21. A commercially available alumina filtration membrane (Anopore, Whatman) was used as the template. Alumina is especially suited for this application because of its high porosity, monodispersity of pore size, and the fact that it can be heated to high temperature without degradation. This membrane contains 200-nm-diameter pores, is 60 p,m thick, and has a porosity of 0.6. A 1.5 cm X 1.5 cm piece of this membrane was mounted on a Pt plate (2 cm X 2 cm) by applying a strip of plastic adhesive tape (also 2 cm X 2 cm NICHIBAN VT-19) across the upper face of the membrane. The Pt plate will serve as the current collector for the LiMn204 battery electrode material. The strip of tape, which will be subsequently removed, had a 1.0 cm circular hole punched in it, which defined the area of the membrane used for the template synthesis of the LiMn204. 

Fig. 9.22 a) SEM micrograph of polystyrene brushes generated via SIP on a substrate that was irradiated through a stencil mask with a coarse grid with 50 pm periodicity. Each square contains an array of circular holes of 1.5 pm dots (2.5 pm periodicity), b) SPM... 

Effect of laminate layup and stacking sequence on stress concentration and strength of boron fiber-epoxy matrix composites containing circular holes under uniaxial tension . 

In order to achieve an overview of the correlation between the geometric size of the hole and the associated leak rate it is possible to operate on the basis of the following, rough estimate A circular hole 1 cm in diameter in the wall of a vacuum vessel is closed with a gate valve. Atmospheric pressure prevails outside, a vacuum inside. When the valve is suddenly opened all the air molecules in a cylinder 1 cm in diameter and 330 m high would within a 1 -second period of time fall into the hole at the speed of sound (330 m/s). The quantity flowing into the vessel each second will be 10 3 mbar times the cylinder volume (see Fig. 5.1). The result is that for a... 

The directional dependence of the mechanical properties of skin was first observed by Langer in 1861. C. R. von E. Langer (1819-1887), an Austrian anatomist, pierced small circular holes in the skin of cadavers and observed that these holes became elliptical with time. By joining the long axes of the ellipses, he produced a series of lines that subsequently were named after him. It is well known to surgeons that incisions made along the direction of Ranger s lines close and heal more rapidly. 

Fill a small iron crucible about one-half to two-thirds full of magnesium powder. Bore a pinhole in the iron lid and then place the lid on the crucible. Lute the lid to the crucible with wet asbestos pulp and close the hole with the same material. (If a lid is not available, twist the crucible on a piece of asbestos board like a biscuit cutter until a deep groove has been cut in it and then lute it to the crucible as before.) Dry the crucible and its contents in an air oven or on the hot plate and when they are dry pierce a small hole in the asbestos plug with a pin. Place the crucible in a circular hole... 

---