Ball packing

Year AA Gun (with fixed Ammo) (pp 352—53) 12-cm (120-mm) Shrapnel Ammo with Proj contg BkPdr as ejecting chge and 539 lead balls packed in a rosin matrix. The proplnt was in two increments each encased in a silk bag with a small igniter chge sewed to the bottom of each the... 

Although the fine powders of ceramic are tightly packed by the effect of the pre-pressure and the gravity, the pore is present among the powders. Assuming the fine pwwders are the sphere which is equal in the radius, the porosity can be calculated by the ball-packed model. 

Honeydew— This variety of melon has a white, smooth rind and light-green pulp. It is about 7 in. (17.5 cm) in diameter and 8 in. (20 cm) long. Honeydew melons grow best in hot, dry climates and require about 4 months to reach maturity. They are called winter melons because they ripen late in the season and are marketed during the winter. Most of the U.S. production comes from irrigated fields in the southwestern and western states. They are usually used fresh and as canned or frozen melon balls packed in syrup. 

Figure Bl.21.1. Atomic hard-ball models of low-Miller-index bulk-temiinated surfaces of simple metals with face-centred close-packed (fee), hexagonal close-packed (licp) and body-centred cubic (bcc) lattices (a) fee (lll)-(l X 1) (b)fcc(lO -(l X l) (c)fcc(110)-(l X 1) (d)hcp(0001)-(l x 1) (e) hcp(l0-10)-(l X 1), usually written as hcp(l010)-(l x 1) (f) bcc(l 10)-(1 x ]) (g) bcc(100)-(l x 1) and (li) bcc(l 11)-(1 x 1). The atomic spheres are drawn with radii that are smaller than touching-sphere radii, in order to give better depth views. The arrows are unit cell vectors. These figures were produced by the software program BALSAC [35]-...

The easy movement of the electrons gives the high electrical conductivity of metals. The metallic bond has no directionality, so that metal ions tend to pack to give simple, high-density structures, like ball-bearings shaken down in a box. 

Fig. 10.4. Ball bearings can be used to simulate how atoms are packed together in solids. Our photograph shows a ball-bearing model set up to show what the grain boundaries look like in a polycrystalline material. The model also shows up another type of defect - the vacancy - which is caused by a missing atom.

Demonstrations (a) Give four injection-moulded close-packed planes to each student to allow personal building of f.c.c. and c.p.h. (b) Atomix atomic model on overhead projector to show atom packing (Emotion Productions Inc., 4825 Sainte Catherine O, Montreal 215PQ, Canada) or ball bearings on overhead projector. 

Metal atoms tend to behave like miniature ball-bearings and tend to pack together as tightly as possible. F.c.c. and c.p.h. give the highest possible packing density, with 74% of the volume of the metal taken up by the atomic spheres. However, in some metals, like iron or chromium, the metallic bond has some directionality and this makes the atoms pack into the more open b.c.c. structure with a packing density of 68%. 

Heat is no longer passed from loop 1 to loop 2 but instead the heat recovered from each active bed in desorption is stored in an inert bed before being passed back to the active bed in the next desorption phase. The inert bed could be as simple as a cylinder packed with steel balls. 

Besides the void fraction a very important parameter is the size of the particles. Using a simple cubic model for packing spherical balls, which represent the particles, we get the following expression for the void fraction... 

Acetylene may propagate decomposition flames in the absence of any oxidant above certain minimum conditions of pressure, temperature, and pipe diameter. Acetylene, unlike most other gases, can decompose in a detonative manner. Among the different types of flame arresters that have proven successful in stopping acetylene decomposition flames are hydraulic (liquid seal) flame arresters, packed beds, sintered metal, and metallic balls (metal shot). 

Ballen, m. bale pack, packet, bundle ball. 

This type was developed to avoid stick-slip in heavily loaded leadscrews. It employs a screw and nut of special form, with bearing balls running between them. When the balls run off one end of the nut they return through an external channel to the other end. Such bearings are usually grease-packed for life. 

The hydraulic fluid continuously lubricates the components of a hydraulic system, which must, of course, be suitable for this purpose. Many ball and roller bearings are grease-packed for life, or need attention at lengthy... 

Golf balls and oranges pack naturally in an FCC structure. 

The C=C group and all four atoms attached to it lie in the same plane and are locked into that arrangement by the resistance to twisting of the TT-bond (Fig. 18.7). Because alkene molecules cannot roll up into a ball as compactly as alkanes or rotate into favorable positions, they cannot pack together as closely as alkanes so alkenes have lower melting points than alkanes of similar molar mass. 

The double bond in alkenes makes them more rigid than alkanes. Some of the atoms of alkene molecules are locked into a planar arrangement by the TT-bond hence, they cannot roll up into a ball as compactly as alkanes can. Because they do not pack together as compactly as alkanes do, they have lower boiling and melting points. 

According to Wisseroth, the agitator design was quite important, and was very similar to those shown in reference 1. The speed was adjustable from 0-360 rpm and a gland packing seal was used. For special operations, metallic balls were added to the reactor to improve temperature stability (10). 

The reason for the low intrinsic viscosities in solution is that dendrimers exist as tightly packed balls. This is by contrast with linear polymers, which tend to form flexible coils. The effect of this difference is that, whereas polymer solutions tend to be of high viscosity, dendrimer solutions are of very low viscosity. In fact, as dendrimers are prepared, their intrinsic viscosity increases as far as the addition of the fourth monomer unit to growing branches (the so-called fourth generation), but this is the maximum value that the viscosity reaches, and as the side chains grow beyond that, the viscosity decreases. 

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