Big Chemical Encyclopedia

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

Articles Figures Tables About

Routes access

Designate supply routes, access routes, fuel resupply points, and/or fuel/fog oil... [Pg.7]

A site survey will be carried out, from which a number of parameters can be established, e.g. carrying capacity of the soil at the planned location, possible access routes, surface restrictions like built-up areas, lakes, nature reserves, the general topography, possible water supplies. The survey will allow the adequate preparation of the future location. For instance, onshore in a swamp area the soil needs to be covered with support mats. [Pg.42]

The first function of a wellsite is to accommodate drilling operations. However, a wellsite must be designed to allow access for future operations and maintenance activity, and in many cases provide containment in the event of accidental emission. Production from a single wellhead or wellhead cluster is routed by pipeline to a gathering station, often without any treatment. In such a case the pipeline effectively becomes an extension of the production tubing. If a well is producing naturally or with assistance from a down... [Pg.260]

Environmental information is available extensively on the free Internet. Two main reasons aeeount for this. First, the freedom of environmental information law and, secondly, the fact that many environmental databases which used to be available only commercially are now accessible on the free Internet. This section focuses on environmental information which is available free of charge on the Internet. Three main paths are distinguished for searching environmental information effectively. In general, all three routes should be taken into consideration for achieving a sound search result for environmental information on chemical stibstances... [Pg.274]

Other Access Routes for Symmetrical and Unsymmetrical Thiazolo Ds-es. Other functionally symmetrical reagents such as diethoxymethylacetate (method C), ethoxymethylenediethylmalonate (method D), diphenyl formamidine, and ethylisoformanilide condense with 2-methylthiazoliura to give the trimethine thiazolo dyes. [Pg.55]

Two different access routes are used, whether the leaving group is carried on thiazolium derivatives such as anilinovinyl (method A), acetanilidovinyl (method B), formyl methylene, or thioformylmethylene or on the ketomethylene compound (method C). The use of acid anhydride together with pyridine has been patented (method E). [Pg.60]

Two access routes are also used with the vinylog derivatives of previous compounds, for example, either 2-(4-anilinobutadienyl)thiazolium with a ketomethylene, or 4-(4-anilinobutadienylidene)ketomethylene with 2-methylthiazolium. [Pg.63]

Depending on the ring substituent, trifluoromethoxyben2enes can be made by the sequential chlorination—fluorination of anisole(s) (351—354). A one-step process with commercial potential is the BF (or SbF2)-cataly2ed reaction of phenol with carbon tetrachloride/hydrogen fluoride (355). Aryl trifluoromethyl ethers, which may not be accessible by the above routes,may be made by fluorination of aryl fluoroformates or aryl chlorothioformates with sulfur tetrafluoride (348) or molybdenum hexafluoride (356). [Pg.333]

Akylsilanes undergo highly regioselective acylation to give P,y-unsaturated ketones (177). Acylation of y,y-dialkylallyltrialkylsilane provides a route to the constmction of difficulty accessible quaternary carbon centers. [Pg.562]

During the 1980s few innovations were disclosed in the Hterature. The hydroxylation of phenol by hydrogen peroxide has been extensively studied in order to improve the catalytic system as well as to master the ratio of hydroquinone to catechol. Other routes, targeting a selective access to one of the dihydroxyben2enes, have appeared. World production capacities according to countries and process types are presented in Table 1. [Pg.486]

Synthesis and Properties. The synthesis of (21) follows a very straightforward route based on readily accessible starting materials and on some novel reactions ia organo—inorganic sulfur chemistry (83—85), as well as on polycondensation chemistry analogous to that utilized ia the preparation of poly(alkyl/arylphosphazenes). One preparation of (21) is as follows ... [Pg.261]

Commercially important arenesulfonyl isocyanates are not directly accessible from the corresponding sulfonamides via phosgenation due to lack of reactivity or by-product formation at elevated temperatures. A convenient method for their preparation consists of the reaction of alkyl isocyanates with sulfonamides to produce mixed ureas which, upon phosgenation, yield a mixture of alkyl and arenesulfonyl isocyanates. The desired product can be obtained by simple distillation (16). Optionally, the oxalyl chloride route has been employed for the synthesis of arenesulfonyl isocyanate (87). [Pg.456]

The hulls are the first material removed from the process to merit concern in respect to safeguards. These represent a possible route for special nuclear material (SNM) to be clandestinely removed from the system. Special instmmentation is used to assay the hulls containers for residual SNM. This step not only monitors the dissolver for proper functioning, but also serves an accountancy function as a material access area portal and enables the satisfaction of contractual requirements regarding process losses (40). [Pg.206]

Vinyl Pyrroles. Relatively new synthetic routes based on a one-pot reaction between ketoximes and acetjiene ia an alkaU metal hydroxide—dimethyl sulfoxide (DMSO) system have made vinyl pyrroles accessible. It requires no pyrrole precursors and uses cheap and readily available ketones (42). [Pg.358]

Rigorous hydrogenating conditions, particularly with Raney Nickel, remove the sulfur atom of thiophenes. With vapor-phase catalysis, hydrodesulfurization is the technique used to remove sulfur materials from cmde oil. Chemically hydrodesulfurization can be a valuable route to alkanes otherwise difficult to access. [Pg.20]

In equation 1, the Grignard reagent, C H MgBr, plays a dual role as reducing agent and the source of the arene compound (see Grignard reaction). The Cr(CO)g is recovered from an apparent phenyl chromium intermediate by the addition of water (19,20). Other routes to chromium hexacarbonyl are possible, and an excellent summary of chromium carbonyl and derivatives can be found in reference 2. The only access to the less stable Cr(—II) and Cr(—I) oxidation states is by reduction of Cr(CO)g. [Pg.134]

In some cases, the /3-haloamine undergoes spontaneous cyclization to the aziridine <70TL1125>. Most of these routes, however, require either reductive or base-induced cyclization to the aziridine. Access to a vast number of aziridines and 1-azirines has been... [Pg.83]

The interaction of acid chlorides (167 X = Cl) with imines in the presence of bases such as triethylamine may involve prior formation of a ketene followed by cycloaddition to the imine, but in many cases it is considered to involve interaction of the imine with the acid chloride to give an immonium ion (168). This is then cyclized by deprotonation under the influence of the base. Clearly, the distinction between these routes is a rather fine one and the mechanism involved in a particular case may well depend on the reactants and the timing of mixing. Particularly important acid chlorides are azidoacetyl chloride and phthalimidoacetyl chloride, which provide access to /3-lactams with a nitrogen substituent in the 3-position as found in the penicillins and cephalosporins. [Pg.260]

In spite of the considerable progress in developing methods for total synthesis, this route to cephalosporins cannot compete with fermentation or penicillin rearrangement (see Sections 5.10.4.1 and 2) for the industrial production of cephalosporin antibiotics. While total synthesis does provide access to nuclear analogs not readily obtainable from fermentation products, none of the totally synthetic materials have displayed sufficient advantages to Warrant their development as new drug products (b-81MI51000). [Pg.295]

Haul distance Although minimum haul distances are desirable, other factors must also he considered. These include collection-route location, types of wastes to he hauled, local traffic patterns, and characteristics of the routes to and from the disposal site (condition of the routes, traffic patterns, and access conditions). [Pg.2253]

Another important issue in layout is the provision of safe access to equipment for emergency response needs such as fire-fighting etc. The layout also needs to provide for safe escape and rescue routes. As far as off-site population is concerned, the most important siting factor is the distance between the process... [Pg.27]


See other pages where Routes access is mentioned: [Pg.101]    [Pg.583]    [Pg.270]    [Pg.167]    [Pg.101]    [Pg.583]    [Pg.270]    [Pg.167]    [Pg.352]    [Pg.802]    [Pg.77]    [Pg.325]    [Pg.319]    [Pg.486]    [Pg.258]    [Pg.262]    [Pg.58]    [Pg.389]    [Pg.74]    [Pg.431]    [Pg.50]    [Pg.326]    [Pg.97]    [Pg.142]    [Pg.224]    [Pg.227]    [Pg.81]    [Pg.89]    [Pg.92]    [Pg.92]    [Pg.121]    [Pg.58]   
See also in sourсe #XX -- [ Pg.206 ]

See also in sourсe #XX -- [ Pg.200 , Pg.201 ]




SEARCH



Administration route accessibility

Interface access routes

© 2024 chempedia.info