BHAs

Beverages, carbonated Beverage spirits, distilled Bexloy V Bezafibrate [41859-67-0] B. Fragilis BFR process Bglll BHA... 

Antioxidants (qv) have a positive effect on oils when present in the proper concentration. Sterols and tocopherols, which are natural antioxidants, may be analy2ed by gas-Hquid chromatography (glc), high performance Hquid chromatography (hplc), or thin-layer chromatography (tic). Synthetic antioxidants maybe added by processors to improve the performance or shelf life of products. These compounds include butylatedhydroxyanisole (BHA), butylated hydroxytoluene (BHT), / fZ-butyUiydroquinone (TBHQ), and propyl gallate. These materials may likewise be analy2ed by glc, hplc, or tic. Citric acid (qv), which functions as a metal chelator, may also be deterrnined by glc. 

BHA and BHT, which are both fat soluble, are effective ia protecting animal fat from oxidation, and are often added duting the rendering process. Propyl gallate is also effective, but it has limited fat solubiUty, and turns bluish black ia the presence of iron. It is typically used as a synergist ia combination with BHA or BHT. TBHQ is most effective against oxidation ia polyunsaturated vegetable oils (qv), and is often used ia soybean oil (19). 

Nut Products. Peanut products iaclude peanut flour, Hpoproteia, proteia, milk, and partially defatted peanuts (109). Pecan butter is made from dry roasted meats, ground to a very fine state, and mixed with salt (2% of final weight), hydrogenated fat (1.5%), and the antioxidant butylated hydroxyanisole (BHA) (131). 

Di-/ l -butyl-4-methylphenol /2j5 i77-2/-i72,6-Di-/ l -butyl-4-methylphenol (di-/ l -butyl-/)-cresolDi-/ l -butyl-j )-cresol or butylated hydroxytoluene (BHT)) is most commonly used as an antioxidant in plastics and mbber. Use in food is decreasing because of legislation and it is being replaced by butylated hydroxy anisole (BHA) (see Antioxidants Eood additives). 

ButylatedHydroxyAnisole (BHA). This material is an oxidation inhibitor and has been accepted for use in foods where the use of butylated hydroxytoluene (BHT) is restricted (see Food additives). It is manufactured by the alkylation of 4-hydroxyanisole [150-76-5] with isobutylene that yields a mixture of 2- and S-Z fZ-butyl isomers as products (124). 

Butylated Hydroxyanisole. 2- and 3-/ i -Butyl-4-methoxyphenol (butylated hydroxyanisole (BHA)) is prepared from 4-methoxyphenol and tert-huty alcohol over siUca or alumina at 150°C or from hydroquinone and tert-huty alcohol or isobutene, using an acid catalyst and then methylating. It is widely used in all types of foods such as butter, lard, and other fats, meats, cereals, baked goods, candies, and beer as an antioxidant (see Antioxidants Eood additives). Its antioxidant properties are not lost during cooking so that flour, fats, and other BHA-stabiLized ingredients may be used to produce stabilized products. 

Treatment with LiAlH4/AlCl3, BHa-NMea/AlCla, " BH3, THF, heat, or NaBH3CN/TMSCl, CH3CN results in cleavage at the least hindered side of the ketal, whereas treatment with NaBH3CN/HCl or NaBH3CN/TFA/DMF" results in formation of an MPM ether at the least hindered alcohol. 

BHA — Change bottom hole assembly DMF — Down hole motor failure DSF — Drill string failure DST — Drill stem test DTF — Down hole tool failure LOG — Run logs CM — Condition mud CP — Core point DP — Drill plug FM — Formation change... 

The gravity tool face angle, or angle between the plane defined by the borehole axis and the vertical and the plane defined by the borehole axis and the BHA axis below the bent sub, can also be calculated. Figure 4-226 shows the gravity tool face angle. It is readily calculated using the equation... 

Two systems are presently used by the MWD service companies concerning the radioactive source installation. One way is to lock the sources in holes in the drill collars. Thus, if the BHA is lost, the sources are left in the formation. 

Another way (Anadrill) is to use removable sources. Figure 4-285 shows the sources being installed in the tool at surface. The two sources, neutrons and gammas, are mounted on the same flexible shaft. They are moved from the shield to the sub without being exposed. Furthermore, if the BHA becomes stuck, they can be fished out with an overshot that connects to the fishing head on top of the neutron source. 

In theory, an increase in RPM decreases stabilizer digging due to increase in the BHA momentum. However, here it did not help. We may have tried the RPM value used around 11,400 ft where no shocks were registered. 

Medium radius and long radius wells are drilled with conventional oilfield tools. Both MWD and LWD are usable in these wells. Downhole motors are mostly used in medium radius wells to avoid fatigue of the BHA. Long radius wells have been drilled with both mud motors and rotary techniques. 

Bottom-hole assembly (BHA) Assembly composed of the rock bit, stabilizers, reamers, drill collars, subs, etc., used at the bottom of the drillstring. 

Directional drilling contractor A service company that supplies the special deflecting tools, BHA, survey instruments and a technical representative to perform the directional drilling aspects of the operation. 

Monel (K monel) A permanently nonmagnetic alloy used in making portions of downhole tools in the bottomhole assembly (BHA) where the magnetic survey tools are placed for obtaining magnetic direction information. Monel refers to a family of nickel-copper alloys. 

C TOHHOCTbro AO Majibix nepBOro nopaAKa OTHOCHTCAbHO Ui,j ypaBHCHHH (1.4) H (1.29) npHHHMaiOT BHA... 

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