Double isolation

No clinically signiflcant interaction appears to occur between the beta blockers and cimetidine, although the blood levels of some extensively metabolised beta blockers (e.g. metoprolol, propranolol) can be doubled. Isolated case reports describe bradycardia, an irregular heart beat, or hypotension in patients taking cimetidine with atenolol, metoprolol, or labetalol, respectively. 

The sorosilicates (pyrosilicates) contain two tetrahedrons that are comer-shared as double-isolated islands of 1207 . This class of silicates is fairly rare. One example, thortveitite, is shown in Figure 12.18. 

Double isolation valves on the pipelines of systems relating to the accident localizing circuit. 

LOCA (Primary) - double isolation valves, guard vessel, pnmaiy cncuit integration I LOCA (Secondary) - 3 independent kxips, double isolation valves L LOCA (Interfacing) - intermediate circuit valves L... 

Double isolation valves m pipelines of pnmaiy circuit Isolation valves of containment ventilation system... 

LOCA (Interfacing) - Double isolation valves in steam, feed water, cooluig water pipelmes of the tertiary circuit for pnmary cucuit pump, cooler-filter, coolmg system pump... 

Double isolation valves of pnmary circuit Bubbler tank, - Passive stem of residual heat removal... 

LOCA (Secondary) Double isolation valves of steam genei ator... 

The secondary circuit serves for heat removal from the primary circuit in the SGs, production of superheated steam, and its further delivery to the turbogenerator set. The secondary circuit is composed of two heat exchange loops each containing an SG made up of 9 sections, piping and valves. Should a primary coolant leak in the SG occur, it can be isolated on water and steam sides by double isolation valves. 

Will adequate design provisions exist for cleanup and preparation of equipment for maintenance of equipment/piping/control systems (including lockout of all energy sources and double isolation where required) ... 

Containment The primary containment comprises the containment vessel, the reactor head closure and fittings, and the intermediate heat exchangers (Fig. 9.61). There are no penetrations in the reactor vessel below the closure head. During power operation, the reactor is hermetically sealed, all sodium and cover gas service lines (in the head closure) are closed with double isolation valves, and all other penetrations are seal-welded. The pressure of the reactor cover gas is approximately atmospheric during normal power operation. The leak... 

CH = CH — CH = CH — are said to have conjugated double bonds and react somewhat differently from the other diolefins. For instance, bromine or hydrogen is often added so that a product of the type -CHBr-CH=CH-CHBr- is formed. Also, these hydrocarbons participate in the Diels-Alder reaction see diene reactions). They show a tendency to form rubber-like polymers. Hydrocarbons not falling into these two classes are said to have isolated double... 

We have already obtained solutions for localized ground-state ethylene leading to the energy F = 2"z -h 2(3, In looking at allyl. the next more complicated case, we can regard it as an isolated double bond between two carbons to which an. y/z carbon is attached. 

Regioselective Hydrogenation- allylic and hornoallylie alcohols are hydrogenated faster than isolated double bonds... 

The intermediate in this double 1,6-elimination may be the pentaene C1-CH=C=C=C=C=CH2, routes via other highly unsaturated compounds cannot be ruled out. Since the elimination is a very clean reaction, prior isolation of the explosive triyne is not always necessary 2-ethynylselenophen, for example, can... 

Thioformamide is prepared in situ at 25 to 30°C. as described previously, and in the presence of magnesium carbonate (492. 512. 578). The mixture is then mildly heated on a water bath, and when temperature reaches 70°C, a-haloaldehyde is added in small quantities. At the end of this addition the reaction mixture is stirred for 2 hr at 100°C. Thiazoles were isolated in the usual manner by a double steam distillation. 

Cycloalkenes that have trans double bonds m rings smaller than 12 mem bers are less stable than their cis stereoisomers trans Cyclooctene can be isolated and stored at room temperature but trans cycloheptene is not stable above -30°C... 

Alkenes are cleaved to carbonyl compounds by ozonolysis This reaction IS useful both for synthesis (preparation of aldehydes ketones or car boxyhc acids) and analysis When applied to analysis the carbonyl com pounds are isolated and identified allowing the substituents attached to the double bond to be deduced... 

Beginning in the 1980s research directed toward the isolation of new drugs derived from natural sources identified a family of tumor inhibitory antibiotic substances characterized by novel struc tures containing a C C—C=C—C C unit as part of a nine or ten membered ring With one double bond and two triple bonds (-ene + di- + -yne) these com pounds soon became known as enediyne antibiotics The simplest member of the class is dynemian A most of the other enediynes have even more compli cated structures... 

A hydrocarbon that contains two double bonds is called an alkadiene, and the rela tionship between the double bonds may be described as isolated conjugated or cumu lated Isolated diene units are those m which two carbon-carbon double bond units are separated from each other by one or more sp hybridized carbon atoms 1 4 Pentadiene and 1 5 cyclooctadiene have isolated double bonds... 

Isolated double bonds are separated from other double bonds by at least one sp hybridized carbon Conjugated double bonds are joined by a single bond ... 

Which IS the most stable arrangement of double bonds m an alkadiene—isolated con jugated or cumulated ... 

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