Material, materials

The mechanism of contact-sorption drying is very complex because moisture transfer takes place in heterogeneous and multicomponent systems and is accompanied by thermal effects. The idealized scheme of contact-sorption drying shown in Figure 12.1 reflects phenomena taking place in a dynamic system (e.g., mixing or fluidization), where interaction between the sorbent-material, material-material, and sorbent-sorbent is likely to occur. 

Migoun N.P. Proceedings of 7 Int. Symp. On Nondestructive Characterization of Materials. Material Science Forum, 1996, v.210-213, part 1, p. 387-388. 

This automatic velocity measurement method (AUTO-V) has also been suecessfijlly applied to other materials sueh as non-ferrous metals and even eeramics and plasties. The only requirement for this type of sequential velocity and thickness measurement is a certain isotropy of the material materials having anisotropie properties will lead to incorrect thickness readings due to the velocity difference in the two orthogonal directions. 

Levy A 1995 Solid Partiole Erosion and Erosion-Corrosion of Materials (Materials Park, OH ASM International)... 

W. H. Sutton and co-workers, eds.. Microwave Processing of Materials Materials Research S ociety Proceedings, Vol. 124, Pittsburgh, Pa., 1988. 

G. I. Stegeman and W. TormeUas, E/ectrica/, Optical, and Magnetic Properties of Organic Solid State Materials, Materials Research Society, Pittsburgh, 1994, pp. 397-412. 

Antireflection coatings are used over the silicon surface which, without the coating, reflects ca 35% of incident sunlight. A typical coating consists of a single layer of a transparent dielectric material with a refractive index of ca 2, which is between the index of siUcon and ait or cover material. Materials such as titanium dioxide, tantalum pentoxide, Ta20, or siUcon nitride, Si N, ca 0.08-p.m thick are common. The coating and a physically textured... 

Luminescent Pigments. Luminescence is the abihty of matter to emit light after it absorbs energy (see Luminescent materials). Materials that have luminescent properties are known as phosphors, or luminescent pigments. If the light emission ceases shortly after the excitation source is removed (<10 s), the process is fluorescence. The process with longer decay times is referred to as phosphorescence. 

Inhalation of certain fine dusts may constitute a health hazard. Eor example, exposure to siUca, asbestos, and beryllium oxide dusts over a period of time results ki the potential risk of lung disease. OSHA regulations specify the allowable levels of exposure to kigestible and respkable materials. Material Safety Data Sheets, OSHA form 20, available from manufacturers, provide information about hazards, precautions, and storage pertinent to specific refractory products. 

Occupational Safety and Health. OSHA has set no specific limits for sodium and potassium sibcates (88). A pmdent industrial exposure standard could range from the permissible exposure limit (PEL) for inert or nuisance particulates to the PEL for sodium hydroxide, depending on the rate of dissolution and the concentration of airborne material. Material safety data sheets issued by siUcate producers should be consulted for specific handling precautions, recommended personal protective equipment, and other important safety information. 

The working capital includes the cost of inventories, such as raw materials, materials-in-process, products, etc as well as suppHes, accounts receivable less accounts payable, prepaid expenses, other cash needs such as payroll, and some start-up expenses, eg, materials and wages. Typical inventories can be taken as one month s supply of raw materials, products, and materials-in-process. The materials-in-process can be valued at one month s sales. Other operating cash can be estimated as the actual cash need for one month. 

The centrifugal pump is the type most widely used in the chemical industiy for transferring liquids of aU types—raw materials, materials in manufacture, and finished produc ts—as well as for general services of water supply, boiler feed, condenser circulation, condensate return, etc. These pumps are available through avast range of sizes, in capacities from 0.5 mVh to 2 X 10 mVh (2 gal/min to 10 gaJ/min), and for discharge heads (pressures) from a few meters to approximately 48 MPa (7000 Ibf/iu"). The size and type best suited to a particular apphcation can be determined only by an engineering study of the problem. 

Materials Materials for hquefied-gas containers must be suitable for the temperatures, and they must not be brittle. Some carbon steels can be used down to —59°C (—75°F), and low-aUoy steels to —101°C (—150°F) and sometimes —129°C (—200°F). Below these temperatures austenitic stainless steel (AISI 300 series) and aluminum are the principal materials. 

Material that remains on a given screening surface is the oversize or plus material, material passing through the screening surface is the undersize or minus material, and material passing one screening surface and retained on a subsequent surface is the intermediate material. 

Pan width, in (mm) Width between skirts, in (mm) Max lump size, in (mm) Capacity, tons/h (metric tons/h) 50-lh/ft (801-kg/m ) hulk-density material material depth on pans, in (mm) ... 

An electrochemical interaction of two or more materials (materials 1 and 2 in Fig. 16.1) having a sufficiently distinct galvanic potential difference... 

Removal of Processed Materials Materials such as product, off-spec material inventory, retained samples, and process... 

It is not certain whether Sir Humphrey Davy (Fig. 1-7) knew of these considerations. He accepted a commission from the Admiralty for the protection of copper-clad wooden ships, which had been introduced in 1761. During his numerous laboratory experiments, he discovered the cathodic protection of copper by zinc or iron [3]. Davy had already put forward the hypothesis in 1812 that chemical and electrical changes are identical or at least arise from the same material property. He believed that chemical reaction forces could be reduced or increased by altering the electric state of the material. Materials can combine only if they have different electric charges. If an originally positive material can be artificially negatively... 

Quality control on raw materials, materials in process, products and wastes Materials control to enable losses, over-use, under-use or accumulations to be detected control of quantities in storage... 

Recycling Use, reuse and recycling of wastes for the original or some other purpose, e.g. input material, materials recovery or energy production d j X ... 

L. Delaey, Diffusionless transformations, in Phase Transformations in Materials, Materials... 

Since the amount of fissile material in the fuel assemblies is only about 3 percent of the uranium present, it is obvious that there cannot be a large amount of radioactive material in the SNF after fission. The neutron flux produces some newly radioactive material in the form of uranium and plutonium isotopes. The amount of this other newly radioactive material is small compared to the volume of the fuel assembly. These facts prompt some to argue that SNF should be chemically processed and the various components separated into nonradioac-tive material, material that will be radioactive for a long time, and material that could be refabricated into new reactor fuel. Reprocessing the fuel to isolate the plutonium is seen as a reason not to proceed with this technology in the United States. 

When a bar is elongated axially, as in Figure 2-25, it will contract laterally. The negative ratio of the lateral strain to the axial strain is called Poisson s ratio v. For isotropic materials, materials that have the same elastic properties in all directions, Poisson s ratio has a value of about 0.3. 

Packaging materials Materials to be used in contact with metals should be as free as possible from corrosive salts or acid. BS 1133, Section 7 1967 gives limits for non-corrosive papers as follows chloride, 0-05% (as sodium chloride) sulphate, 0-25% (as sodium sulphate) and pH of water extract 5 -5-8 0. Where there is doubt, contact corrosion tests may be necessary in conditions simulating those in the package. 

Limiting size factor Material / Material plane Equipment profile Material revolution Equipment Equipment plane Equipment Material plane Material Equipment plane Mold Size... 

Alexandre, M. and Dubois, P. 2000. Polymer-layered silicate nano-composites preparation, properties and uses of a new class of materials. Materials Science and Engineering 28 1- 63. 

Surface area is one of the most important factors in determining throughput (amount of reactant converted per unit time per unit mass of catalyst). Many modem inorganic supports have surface areas of 100 to >1000 m g The vast majority of this area is due to the presence of internal pores these pores may be of very narrow size distribution to allow specific molecular sized species to enter or leave, or of a much broader size distribution. Materials with an average pore size of less than 1.5-2 nm are termed microporous whilst those with pore sizes above this are called mesoporous materials. Materials with very large pore sizes (>50 nm) are said to be macroporous, (see Box 4.1 for methods of determining surface area and pore size). 

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