Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Spoiling

Other compounds which may be found in crude oil are metals such as vanadium, nickel, copper, zinc and iron, but these are usually of little consequence. Vanadium, if present, is often distilled from the feed stock of catalytic cracking processes, since it may spoil catalysis. The treatment of emulsion sludges by bio-treatment may lead to the concentration of metals and radioactive material, causing subsequent disposal problems. [Pg.94]

After these improvements the system was able to measure at drawing speeds up to 500 m/min on one channel. At higher velocities vibrations spoiled the measurements. The water remaining on the tube after the measuring chamber was removed using a pressured air system. [Pg.899]

Although this first route was simple in concept, it proved slow in operation, difficult to scale up safely, and relatively uneconomical compared with the other routes. Denitration of the fibers, necessary to allow safe use wherever the fabrics may risk ignition, spoiled their strength and appearance. Nevertheless, Chardoimet earned and truly deserved his reputation as the Eather of Rayon. His process was operated commercially until 1949 when the last factory, bought from the Tubize Co. in the United States in 1934 by a Bra2iUan company, burned down. [Pg.344]

ASTM D3946 spoiled material organism growth, physical change... [Pg.92]

One of the requirements of this process is that the melt maintain good contact with the chill roU, ie, air must not pass between the film and the roU. Otherwise, air insulates the plastic and causes it to cool at a rate different from the rest of the plastic and this spoils the appearance of an otherwise satisfactory product. The melt should not emit volatiles, which condense on the chill roU, reduce heat transfer, and mar the film s appearance. The cast film process allows the use of a higher melt temperature than is characteristic of the blown film process. The higher temperature imparts better optical properties. [Pg.139]

A funnel flow bin typically exhibits a first-in/last-out type of flow sequence. If the material has sufficient cohesive strength, it may bridge over the outlet. Also, if the narrow flow channel empties out, a stable rathole may form. This stable rathole decreases the bin s five or usable capacity, causes materials to cake or spoil, and/or enhances segregation problems. Collapsing ratholes may impose loads on the stmcture that it was not designed to withstand. [Pg.552]

Beer taste can be spoiled by contaminating bacteria or yeasts. The most common bacteria are lactic and acetic acid producers and T ymomonas. Wild yeasts can be anything other than the intended strain S. uvarum is considered a contaminant of ale fermentations and S. cerevisiae a contaminant of lager fermentations. The common wild yeast contaminants are S. diastaticus and species of Picbia, Candida and Brettanomjces. It may be noted that the flavor of beer may be improved by the ability of yeast to adsorb bitter substances extracted from hops, such as humulones and isohumulones. [Pg.391]

Coum rinic Acid Compounds. These synthetic phyUoquinone derivatives and congeners have been employed as anticoagulants since the isolation of 3,3 -methylenebis(4-hydroxy-2H-l-benzopyran-2-one) [66-76-2] (bis-4-hydroxycoumarin or dicoumarol) (1) from spoiled sweet clover in 1939. The ingestion of the latter was responsible for widespread and extensive death of bovine animals at that time. The parent compound for the synthesis of many congeners is 4-hydrocoumarin, which is synthesized from methyl salicylate by acetylation and internal cyclization. The basic stmctures of these compounds are shown in Figure 2, and their properties Hsted in Table 6 (see Coumarin). [Pg.177]

Hydroxycoumarin [1076-38-6] can be synthesized by cyclization of acetyl methyl salicylate. It is a coumatin metaboHte occurring in spoiled hay. Derivatives of 4-hydroxycoumarin such as dicoumarol [66-76-2] warfarin [81-81-2] cyclocoumarol [518-20-7] ethylbis—coumaracetate [548-00-5] and bis-4-hydroxycoumarin [25892-93-7] are synthetic blood anticoagulants (see Blood, coagulants and anticoagulants). [Pg.322]

Dicoumarol [66-76-2] (5) was isolated from spoiled sweet clover hay. It is prepared synthetically by reaction of 4-hydroxycoumarin with formaldehyde (85). It is used in anticoagulant therapy often associated with heparin. [Pg.322]

In most applications, far less current and lower voltages are used. For example, in dewatering clay soils to stabilize dams, foundations, or dredged spoil, 20—100 V/m are commonly applied (130,131). In soil stabilization (qv), power is applied for weeks to months. [Pg.26]

Learning Curves It is usual to learn from experience. Consequently, the time taken to produce an article, the number of spoiled batches, the cost per unit of production, etc., tend to decrease with the number of units produced. The relationships are expressed for the ideal case by... [Pg.818]

Histamine is the biological amine, playing an important role in living systems, but it can also cause unnatural or toxic effects when it is consumed in lai ge amounts. It can occur with some diseases and with the intake of histamine-contaminated food, such as spoiled fish or fish products, and can lead to undesirable effects as headache, nausea, hypo- or hypertension, cai diac palpitations, and anaphylactic shock syndrome. So, there is a need to determine histamine in biological fluids and food. [Pg.381]

Run-of-the-mill instruments can achieve a resolution of 5-10 nm, while the best reach 1 nm. The remarkable depth of focus derives from the fact that a very small numerical aperture is used, and yet this feature does not spoil the resolution, which is not limited by dilfraction as it is in an optical microscope but rather by various forms of aberration. Scanning electron microscopes can undertake compositional analysis (but with much less accuracy than the instruments treated in the next section) and there is also a way of arranging image formation that allows atomic-number contrast, so that elements of different atomic number show up in various degrees of brightness on the image of a polished surface. [Pg.225]

Colliery spoil Mining Mainly tipping on land, some in sea Some used As fill and in manufacture of bricks, cement and lightweight aggregate... [Pg.499]

It is surprising that the vent was routed into an underground pumphouse. It seems that this was done because the local authority objected to any vents that might spoil the view. [Pg.73]

The other problem in the AIM approach is the presence of non-nuclear attractors in certain metallic systems, such as lithium and sodium clusters. While these are of interest by themselves, they spoil the picture of electrons associated with nuclei forming atoms within molecules. [Pg.224]


See other pages where Spoiling is mentioned: [Pg.100]    [Pg.409]    [Pg.101]    [Pg.366]    [Pg.370]    [Pg.284]    [Pg.350]    [Pg.459]    [Pg.372]    [Pg.259]    [Pg.295]    [Pg.411]    [Pg.358]    [Pg.390]    [Pg.394]    [Pg.25]    [Pg.395]    [Pg.1540]    [Pg.2138]    [Pg.2209]    [Pg.81]    [Pg.157]    [Pg.490]    [Pg.491]    [Pg.534]    [Pg.355]    [Pg.573]    [Pg.578]    [Pg.288]    [Pg.317]    [Pg.330]    [Pg.181]    [Pg.393]    [Pg.516]   
See also in sourсe #XX -- [ Pg.304 ]




SEARCH



Acid spoil

And spoiling

Fast-spoiled gradient-echo sequence

Growing crops on subsoils and mine spoils

In fresh and spoiling

Mine spoils

Mine waste spoil heaps

Q-spoiling

Smell, spoiled products

Spoil containment dyke structures

Spoil heaps

Spoiled child

Spoiled iron

Taste, spoiled products

Toxic spoil

Upper spoils

© 2024 chempedia.info