General Description


Instability of Cylindrical Columns. C. V. Boys, in his elegant little monograph of 1890 [3], discusses an important property of quasistatic cylindrical films that was first studied in cylindrical columns of fluids by Lord Rayleigh in 1879. If the soap film in Fig. II-4a were made to be cylindrical by adjusting the gas pressure inside, it, like a cylindrical thread of fluid, would be unstable to surface waves whose length exceeds the circumference of the cylinder. The column would contract at one end and bulge at the other, as illustrated in Fig. II-4b, before breaking up into a smaller and larger bubble (or drop) as shown in the photographs of a liquid stream in Fig. II-5 [4]. The mechanism is associated with the nonzero curvature of the static state and the fact that fluctuations establish capillary pressure gradients that drive the fluid away from the equilibrium. It is now recognized that capillary breakup is a particularly simple example of the geometric instability of states of static equilibrium in the presence of surface tension. For a general description dealing with pendant and sessile drops, finite cylinders (capillary bridges) and other capillary surfaces, see Michael [5]. A detailed discussion of the capillary break up of jets, including several interesting practical applications, is given by Bogy [6]. The case of one liquid in a second, immiscible one is discussed in Refs. 6a and 7. A similar instability occurring in a thin annular coating inside a capillary can have important consequences for capillary columns in chromatography [8].  [c.9]

B1.23.4.4 GENERAL DESCRIPTION OF SIMULATION PROGRAM  [c.1811]

Given tire general description of tire electromagnetic field, let us explore the sources available for optoelectronics. The one primary light source for optoelectronic device and system architectures is tire laser. The laser [10] is tire source of choice simply because if we want to control light fields tliey need to be well defined at tire start and tire laser is tire most  [c.2857]

The use of general descriptive names, registered names, trademarks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use.  [c.496]

Considering the complexity of the classes of wine already described, only general descriptions can be given (23,24). Because they represent such a large portion of total U.S. wine production (Tables 5 and 7), table wines and the practices in California are emphasized.  [c.370]

The first anhydride plant in actual operation using methyl acetate carbonylation was at Kingsport, Tennessee (41). A general description has been given (42) indicating that about 900 tons of coal are processed daily in Texaco gasifiers. Carbon monoxide is used to make 227,000 t/yr of anhydride from 177,000 t/yr of methyl acetate 166,000 t/yr of methanol is generated. Infrared spectroscopy has been used to foUow the apparent reaction mechanism (43).  [c.77]

Ethylene glycol can be manufactured by the transesterification of ethylene carbonate. A process based on the reaction of ethylene carbonate with methanol to give dimethyl carbonate and ethylene glycol is described in a Texaco patent (13) a general description of the chemistry has also been pubUshed (14) (eq. 19). Selectivities to ethylene glycol are excellent with Htde diethylene glycol or higher glycols produced. A wide range of catalysts may be employed including ion-exchange resins, zirconium and titanium compounds, tin compounds, phosphines, acids, and bases. The process produces a large quantity of dimethyl carbonate which would require a commercial outlet.  [c.359]

In a more general description of the relation between these stmctures and their tendency to aggregate (11), compact dyes were defined as stmctures that were planar but with tightly packed substituents from a steric hindrance view-point these dyes aggregated readily. Less hindered loose dyes (perhaps having several conformations) or more hindered crowded dyes (probably non-planar) do not aggregate as well. Of course, other groups such as the R-substituents also influence aggregation. For the benzoxazole dyes (37) (X = oxygen, n = 1), appropriate R-substituents (on each benzene ring) can enhance J-aggregation (producing spectral absorption near 550 nm or favor the monomeric dye (spectral absorption near 510 nm and sensitization in the short green spectral region).  [c.399]

The bulk of the world production of butyl rubber is made by a precipitation (slurry) polymerization process in which isobutylene and a minor amount of isoprene are copolymerized using aluminum chloride in methyl chloride at —100 to —90 °C. General descriptions of the process and patent information are found in the Hterature (34—56). An alternative solution process, developed in Russia, uses a C —hydrocarbon as solvent and an aluminum alkyl haUde. The polymerization is conducted in scraped surface reactors at —90 to —50 ° C. The solution process avoids the use of methyl chloride, and is an advantage when butyl mbber is to be halogenated. However, the energy costs are higher than that for the slurry process, and because of continuing technical advances, the weU-estabhshed slurry process is unlikely to be displaced. Halogenated butyl mbbers are produced commercially by dissolving butyl mbber in hydrocarbon solvent and contacting the solution with elemental halogens.  [c.482]

General Description Iron and steel  [c.97]

General description. Burnthrough as discussed here specifically refers to the melting of tube metal in the vicinity of the weld such that a cavity is formed. If burnthrough is severe, a continuous channel may be produced that can cause leakage.  [c.328]

General description. In incomplete fusion, complete melting and fusion between the base metal and the weld metal or between individual weld beads does not occur (Fig. 15.8). Incomplete fusion that produces crevices or notches at surfaces can combine with environmental factors to induce corrosion fatigue (Chap. 10), stress-corrosion cracking (Chap. 9), or crevice corrosion (Chap. 2). See Fig. 15.9.  [c.333]

General description. Incomplete penetration describes the condition in which the weld fails to reach the bottom of the weld joint, resulting in a notch located at the root of the weld (Fig. 15.12). This critical defect can substantially reduce the intrinsic mechanical strength of the joint and can combine with environmental factors to produce corrosion fatigue (Chap. 10), stress-corrosion cracking (Chap. 9), or crevice corrosion (Chap. 2).  [c.335]

General description. Laminations are thin surfaces of nonmetallic substances, often oxides, sulfides, or silicates, that can run parallel to the surface of wrought metals such as plate, pipe, and tubes. They generally originate in the ingot and are expanded into thin sheets during subsequent hot-working processes. Laminations can cause defects or cracks in welded components (Fig. 15.13). Welding imposes stresses that can cause the lamination to spread apart. The crack formed in this manner may then propagate into the weld itself.  [c.336]

General description. Porosity refers to cavities formed within the weld metal during the solidification process. Such cavities may form due to decreased solubility of a gas as the molten weld metal cools or due to gas-producing chemical reactions within the weld metal itself. At times, cavities can form a continuous channel through the weld metal (worm holes, piping), resulting in leaks (Case History 15.3).  [c.337]

General description. Slag inclusions are various nonmetallic substances that become entrapped in the weld during the welding process. Typically, the inclusions are located near the surface and along the sides of the weld (Fig. 15.15). The inclusions may form from reactions occurring in the weld metal or may be metal oxides present on the metal prior to welding. They may be isolated particles or may form relatively continuous bands.  [c.338]

General description. The most common and best-known form of metallurgical weld defect in stainless steel is termed weld decay. Weld decay is disintegration in narrow zones of metal located adjacent and parallel to the weld, where sensitization occurs. Sensitization, in a welding context, refers to the formation of chromium carbides in the grain boundaries of the metals being joined as a consequence of the high temperatures produced during the welding process. Sensitization occurs in a specific temperature range that may be encountered along a pair of narrow zones parallel to the weldment. The formation of chromium carbides causes a severe depletion of dissolved chromium in the metal in an envelope surrounding each affected metal grain (Fig. 15.16). Since the corrosion resistance of stainless steel is directly linked to the concentration of chromium dissolved in the metal, the loss of chromium around each grain within these narrow zones renders them susceptible to various forms of degradation, such as corrosion and cracking, in a sufficiently aggressive environment.  [c.339]

General description. In weld-root cracking, cracks originate at the root of the weld (Fig. 15.17). Such cracks may propagate into the weld, through the weld, into adjacent components, or through a relatively brittle heat-affected-zone base metal.  [c.342]

This error can generally be avoided if the basic elements of the galvanic couple, as outlined under General Description, are duly recognized. Hence, corrosion of one member of a couple when both metals are galvanically similar is probably not due to galvanic corrosion (note Cautions with respect to stainless steels). Corrosion of one member of a couple exposed to a common, nonconducting fluid is not galvanic corrosion, since current must flow through the fluid to complete the galvanic circuit. Corrosion of one metal that is not coupled to a dissimilar metal is not galvanic corrosion, since a common current must pass through both metals to complete the galvanic circuit.  [c.363]

Avoid the common tendency to attribute to galvanic corrosion the deterioration of one metal simply because another metal is nearby. The conditions necessary for galvanic corrosion are specific, and all must be operating simultaneously for it to occur. These conditions are outlined in the General Description section of this chapter.  [c.365]

Hays E F and Allen L C 1970 Mole. A system for quantum chemistry I. General description Int. J. Quantum Chem. S 3 715-25 Hehre W J, Lathan W A, Ditchfieid R, Newton M D and Popie J A 1971 Program No 236 (Bloomington, IN Quantum Chemistry Program Exchange)  [c.2195]

A more general description of the effects of vibronic coupling can be made using the model Hamiltonian developed by Kdppel, Domcke and Cederbaum [65]. The basic idea is the same as that used in Section in.C, that is to assume a quasidiabatic representation, and to develop a Hamiltonian in this picture. It is a useful model, providing a simple yet accurate analytical expression for the coupled PES manifold, and identifying the modes essential for the non-adiabatic effects. As a result it can be used for comparing how well different dynamics methods perform for non-adiabatic systems. It has, for example, been used to perform benchmark full-dimensional f24-mode) quantum dynamics calculations  [c.284]

The conformation-dependent chirality code constitutes a more general description of molecular chirality, which is formally comparable with the CICC [43], The main difference is that chiral carbon atoms arc now not explicitly considered, and combinations of any four atoms are now used, independently of the existence or nonexistence of chiial centers, and of their belonging or not belonging to ligands of chiral centers.  [c.423]

The behaviour of quinazoline removes it from this general description nitration in sulphuric acid gives 6-nitroquinazoline. It has been suggested that this result may arise because the entity being nitrated is the hydrated quinazolinium cation, but the anhydrous di-cation is evidently the dominant species in strongly acidic solutions. Kinetic studies of the nitration of quinazoline in sulphuric acid were frustrated by the decomposition which occurs. Phthalazine is not easily nitrated. It is unaffected by mixtures of concentrated sulphuric acid and fuming nitric acid at 0 °C, and at higher temperatures these mixtures cause oxidation to phthalic acid, as does fuming nitric acid alone. Nitration, without oxidation, can be achieved by the use of potassium nitrate in 98 % sulphuric acid, the product being exclusively 5-nitrophthalazine  [c.207]

Bast fibers occur iu the phloem or bark of certain plants. The bast fibers are iu the form of bundles or strands that act as reinforcing elements and help the plant to remain erect (Fig. 1). The plants are harvested and the strands of bast fibers are released from the rest of the tissue by retting, common for isolation of most bast fibers. The retted material is then further processed by breakiug, scutching, and hackling. A general description of the processiug of bast fibers is given below with modifications for specific fibers described iu the foUowiug sections.  [c.360]

BWRf 6 General Description of a Boiling Water Reactor, General Electric Co., Nuclear Energy Group, San Jose, California, 1980.  [c.226]

The bulk of the patent specification is the disclosure, the text and illustrations that describe the claimed invention in detail and explain how the claimed invention differs from the prior art. Modem patent disclosures contain a summary of the claimed invention, a description of the background of the invention, a general description of the way in which the invention is made and used, specific examples, and, where appHcable, drawings of the invention in general or specific embodiments. The technical information provided in a patent specification may be used without infringing the patent only practicing the invention defined in the claims within the term and territory of the patent grant is forbidden. Because much of the information in patent specifications is never pubHshed in refereed journals or other nonpatent media, patent disclosures are an invaluable part of the technical Hterature.  [c.45]

Information on measurement of fiber diameter using optics is available (13). ASTM D629, Sections 23 through 28, describes procedures for determining fiber diameter using microscopic analysis. Characterization of cotton fibers by cross-section, fineness, and maturity has been discussed (3,14), as have one simple method for determining fiber cross-sectional area and length (15) and general descriptions of methods for measuring and calculating fiber transverse dimensions (3).  [c.454]


See pages that mention the term General Description : [c.329]    [c.3]    [c.13]    [c.37]    [c.67]    [c.119]    [c.159]    [c.185]    [c.295]    [c.315]    [c.343]    [c.355]   
See chapters in:

The Nalco Guide to Cooling Water System Failure Analysis  -> General Description

The Nalco Guide to Cooling Water System Failure Analysis  -> General Description

The Nalco Guide to Cooling Water System Failure Analysis  -> General Description

The Nalco Guide to Cooling Water System Failure Analysis  -> General Description

The Nalco Guide to Cooling Water System Failure Analysis  -> General Description

The Nalco Guide to Cooling Water System Failure Analysis  -> General Description

The Nalco Guide to Cooling Water System Failure Analysis  -> General Description

The Nalco Guide to Cooling Water System Failure Analysis  -> General Description

The Nalco Guide to Cooling Water System Failure Analysis  -> General Description

The Nalco Guide to Cooling Water System Failure Analysis  -> General Description

The Nalco Guide to Cooling Water System Failure Analysis  -> General Description

The Nalco Guide to Cooling Water System Failure Analysis  -> General Description

The Nalco Guide to Cooling Water System Failure Analysis  -> General Description

The Nalco Guide to Cooling Water System Failure Analysis  -> General Description

The Nalco Guide to Cooling Water System Failure Analysis  -> General Description