Criticism, impact

The choice of solvent may have a critical impact on efficiency too. In metathesis, dichloromethane, 1,2-dichloroethane and toluene are the solvents most commonly used. There are examples that show much higher yields in ring closing metathesis (RCM) when using fluorinated solvents [150]. An impressive effect of hexafluorobenzene as a solvent for CM is the modification of the steroid 93 the use of 1,2-dichloroethane leads to a very low yield and significant amounts of dimerisa-tion while the same reaction proceeds in 90% yield in C F (Scheme 3.14) [151]. 

The choice of tridentate amine has a critical impact on the coordination mode of the ambidentate nitrite ligand, N02.499,500 Complexes with substituted tri- and tetraamines have shown that bulky substituents may prevent the formation of the -N02 bridged polymeric complexes, and the intramolecular hydrogen network may stabilize N coordination of nitrite. 

The security and economic stability of many nations and multinational oil companies are highly dependent on the safe and uninterrupted operation of their oil, gas and chemical facilities. One of the most critical impacts that can occur to these operations are fire and explosions from accidental or political incidents. The recent Gulf War amply demonstrates the impact these events can have on oil installations. 

Yarin and Weiss[357] also determined the number and size of secondary droplets, as well as the total ejected mass during splashing. Their experimental observations by means of a computer-aided charge-coupled-device camera and video printer showed that the dependence of the critical impact velocity, at which splashing initiates, on the physical properties (density, viscosity, and surface tension) and the frequency of the droplet train is universal, and the threshold velocity may be estimated by ... 

Clearly, the meteorological inputs have a critical impact on model predictions and effects in uncertain-... 

Fig 1) Critical impact velocity as a function of explosive length, for 6-inch diameter 9404 PBX billets impacted by 6-inch diameter by 1-inch thick steel plates... 

The critical impact energy and critical impact vel found for HMX as a function of d are shown below ... 

Density, Critical Impact Critical Impact g/cc Energy, erg/g Vel, m/sec... 

As indicated in Vol 4, D394-L, the detonation velocity of TNT increases from 6025 to 6440 m/sec as the density increases from 1.30 to 1.50g/cm3. A straight-hne relationship has been demonstrated (Ref 150). The detonation temp also increases with density (Vol 4 D492-L). Both of these parameters are discussed in more recent papers (Refs 159 167). The critical impact energy and critical impact velocity have also been determined as functions of the density of TNT (Ref 150)... 

The Failure Mode and Effect Analysis (FMEA) is based on the systematic analysis of failure modes for each element of a system, by defining the failure mode and the consequences of this failure on the integrity of that system. It was first used in the 1960s in the field of aeronautics for the analysis of the safety of aircraft [15]. It is required by regulations in the USA and France for aircraft safety. It allows assessing the effects of each failure mode of a system s components and identifying the failure modes that may have a critical impact on the operability safety and maintenance of the system. It proceeds in four steps ... 

In addition to a change coordinator, there may be a place for a change management team or committee. These individuals will address major changes that have a critical impact on the operation and that require a significant amount of coordination to assure everything happens within a reasonable time frame and within a clearly defined pathway. 

In summary, the severity of ischemia has a critical impact on the amount of neuroprotection obtained with postischemic hypothermia (12,27). Brief hypothermic periods (e.g., <5 h) are not very efficacious and only delay cell death. Prolonged bouts (e.g., 24 -8 h) of hypothermia... 

The observation of two distinct active site binding directions had critical impact on the design of novel class II type inhibitors in the course of the SmithKline Beecham medicinal chemistry effort. Our long term strategy for developing improved cathepsin K inhibitors had been to increase inhibitor selectivity by using electrophilic groups of lower intrinsic chemical reactivity than the aldehydes. It... 

Critical Impact Computer systems have a critical impact if failure or latent design flaws can result in injury or illness to the consumer of the drug that ... 

Hardness and friability tests are two additional tests usually performed as in-process controls during manufacturing. They will be required for product release when the characteristics of hardness and friability have a critical impact on the quality of the product. Carbamazepine is also available as a chewable tablet and because the hardness is an important characteristic of the tablet, a hardness test is required for batch release. 

Hardness/friability. If these characteristics have a critical impact on product quality (e.g., chewable tablets), acceptance criteria should be included in the specification. 

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