Aluminium parameters 98

Correct-overlapping of joint is an important parameter to make a good joint, as well as to allow no excessive heat at the joints. Based on the recommendations of the leading aluminium section manufacturers, the desired overlaps are shown in Table 29.1, and two such joints are illustrated in Figures 29.4 and 29.6. Laboratory tests and site experience have revealed that a larger overlap is of no additional benefit. For larger sections also, only... 

Introduction Types of metal-enclosed bus systems Design parameters and service conditions for a metal enclosed bus system Short-circuit effects Service conditions Other design considerations Skin effect Proximity effect Sample calculation for designing a 2500 A non-isolaled phase aluminium busbar systern... 

The crystallographic requirement for tire formation of G-P zones is that the material within the zones shall have an epitaxial relationship with the maUix, and tlrus the eventual precipitate should have a similar unit cell size in one direction as tha maUix. In dre Al-Cu system, the f.c.c. structure of aluminium has a lattice parameter of 0.4014 nm, and the tetragonal CuAl2 compound has lattice parameters a — 0.4872 and b — 0.6063 nm respectively. 

Aluminium sheet is to be rolled according to the following parameters starting thickness 1 mm, reduced thickness 0.8 mm, yield strength 100 MPa. What roll radius should be chosen to keep the forming pressure below 200 MPa ... 

When E/p is the important parameter, there is nothing to choose between steel, aluminium or fibre glass (Table 25.2). But when E /p is controlling, aluminium is better than steel that is why it is the principal airframe material. Fibreglass is not... 

The theoretical anode capacity can be calculated according to Faraday s law. From this it can be shown that 1 kg of aluminium should provide 2981 Ah of charge. In practice, the realisable capacity of the anode is less than the theoretical value. The significance of the actual (as opposed to the theoretical) anode capacity is that it is a measure of the amount of cathodic current an anode can give. Since anode capacity varies amongst anode materials, it is the parameter against which the anode cost per unit anode weight should be evaluated. 

From 30 at % Ca content in y-Al203 new peaks appear in the spectra which can be attributed to Cai2AIu033 (Mayenite) [13] (see Fig.5c ). This mixed calcium-aluminium oxide has a cubic structure with the cell parameter a = 11.982 A... 

Schetinger MRC, Morsch VM, Bohrer D (2003) Aluminium Interaction with Nucleotides and Nucleotidases and Analytical Aspects of Determination 104 99-138 Schmidtke HH (2003) The Variation of Slater-Condon Parameters Fk and Racah Parameters B and C with Chemical Bonding in Transition Group Complexes 106 19-35 Schubert DM (2003) Borates in Industrial Use 105 1-40... 

All aspects of prevention of magnesium (and aluminium) dust explosions in storage, handling or processing operations are covered in two recent US National Fire Codes [1]. Effects of various parameters on ignition of magnesium powders were studied [2], Maximum explosion pressures of 7.9 bar, with maximum rate of rise of 884 bar/s have been recorded [3],... 

By careful control of these parameters aluminium may be separated, and few interferences are observed if the precipitation is carried out from an ammoniacal-cyanide-EDTA solution. When large amounts of Ca or Mg are present the homogeneous precipitation procedure (Table 5.18) is usefully employed at pH = 5. The precipitate is readily filtered and may be weighed after drying at 150°C as the anhydrous compound. 

Although there are some important differences between what we describe as 3-connected aluminium sites in our bb-matrices and what the active sites are thought to be in zeolites, we have begun a preliminary study of the activities of the Al, Ti and V-containing bb-catalysts as solid acid catalysts in the dehydration of alcohols. For this type of bench marking reaction, there are two parameters that can be used as preliminary indicators of catalytic activity lightoff temperatures and product selectivity. A plot of conversion versus temperature produces what is known as a lightoff curve. The temperature at which 50% of the maximum... 

Fluoride is a natural component of most types of soil, in which it is mainly bound in complexes and not readily leached. The major source of free fluoride ion in soil is the weathering and dissolution of fluoride rich rock that depends on the natural solubility of the fluoride compound in question, pH, and the presence of other minerals and compounds and of water. The major parameters that control fluoride fixation in soil through adsorption, anion exchange, precipitation, formation of mixed solids and complexes are aluminium, calcium, iron, pH, organic matter and clay [19,20]. 

The resultant pair potentials for sodium, magnesium, and aluminium are illustrated in Fig. 6.9 using Ashcroft empty-core pseudopotentials. We see that all three metals are characterized by a repulsive hard-core contribution, Q>i(R) (short-dashed curve), an attractive nearest-neighbour contribution, 2( ) (long-dashed curve), and an oscillatory long-range contribution, 3(R) (dotted curve). The appropriate values of the inter-atomic potential parameters A , oc , k , and k are listed in Table 6.4. We observe that the total pair potentials reflect the characteristic behaviour of the more accurate ab initio pair potentials in Fig. 6.7 that were evaluated using non-local pseudopotentials. We should note, however, that the values taken for the Ashcroft empty-core radii for Na, Mg, and Al, namely Rc = 1.66, 1.39, and... 

Table 6.4 Pair potential parameters for sodium, magnesium, and aluminium at their equilibrium volumes. (From Pettifor and Ward...

The pH of the soil is an important parameter since it can affect the plant s ability to take up nutrients and the microbial activity in the soil that influences the processes required for plant nutrition. Changes in soil pH occur by the displacement of cations or by additions of sources of acidity such as hydrogen and aluminium ions (Tisdale ef al. 1993). 

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