Unsuccessful Applications

Some arresters were used under conditions that exceeded their test limitations. 

Some units failed because they had working channels that were distorted by the flame front overpressure. 

Some failed due to structural or design flaws that provided a flame pathway through the element. 

Case Histories of Suooessful and Unsuooessful AppHoations of Flame Arresters 9 

Fabiano et al. (1999) describe an explosion in the loading section of an Italian acetylene production plant in which the installed flame arresters did not stop a detonation. The arresters were deflagration type and the arrester elements were vessels packed with silica gel and aluminum plates (Fabiano 1999). It was concluded that the flame arresters used were not suitable for dealing safely with the excess pressures resulting from an acetylene decomposition, and may not have been in the proper location to stop the detonation. 

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Case Histories of Successful and Unsuccessful Applications of Flame Arresters... 

Such revisions to the problem statement in order to overcome unsuccessful applications of the search procedure may have to be repeated a... 

In 1999, HRC was used with other treatment technologies at a brownfield site in Aurora, Colorado. An in situ air sparge/soil vapor extraction system was first used at the site to treat TCE contamination however, additional measures were needed to prevent the migration of PCE off-site. After an unsuccessful application of zero-valent iron injection, 240 lb of HRC were injected at five locations by direct-push methods. Total project costs were 110,000, which... 

It is much more complicated to draw conclusions after an unsuccessful application of the method of movement to optimum along the gradient. Drawing conclusions depends much more on whether the optimum is close by, far away or its position is unknown, and whether the linear model is adequate. Typical cases of such situations are demonstrated in Fig. 2.46. 

There is only one solution then to examine reasons for inadequacy of the linear model according to block diagram Fig. 2.39. We can name several causes of unsuccessful application of the steepest ascent method ... 

There is a timeline set of 6-18 months for the review of a submitted derogation and during this period the surfactant can still be marketed. It is expected that a phase out period of up to 2 years could be allowed in the event of an unsuccessful application or change in the derogation conditions. The manufacturers or importers will be required to maintain a technical file which identifies the source and validity of the test data for review by competent authorities. 

Evelyn Marion Hickmans,97 bom in Wolverhampton in 1883, obtained a B.Sc. at the University of Birmingham in 1905 and an M.Sc. in 1906. In 1909, she was a signatory of the 1909 letter to Chemical News, but she gave no affiliation. Curiously, there is no record of her from 1906 until 1919, apart from an unsuccessful application for a Demonstratorship at Bedford in 1906. From 1919 until 1922, she was a Lecturer in the Household Science Department of the University of Toronto, Canada, returning to England in 1923. 

According to our knowledge, the explanation of the aetiology of ascites goes back to O.E. Nadeau et al. (1925) and s.M. Fierst et al. (1975). After the unsuccessful application of all diagnostic procedures available today, laparoscopy ascertained the cause of ascites in 86% of cases. (207, 290) (s. figs. 16.9 37.22)... 

An unsuccessful application zone is cut off and the samples are applied again. 

M.E. Vol pin (1923-1996) was a Dr. chem. sci. (1959), an academician (1987), and the director of INEOS (1988-1996). Vol pin got a contract at INEOS only as a result of persistent efforts of Kursanov in 1958, 3 years after he began work unofficially for free in Kursanov s laboratory, because of restrictions for persons of Jewish nationality (see [54]). I met them both during my unsuccessful application to INEOS in 1961 (see Sect. 9.2). 

Application of the Bischler-Napieralski reaction to amides of tryptophan has been investigated. The cyclodehydration of acetyltrypto-phan under conventional conditions proved unsuccessful. Attempted ring closure of acetyltryptophan or its ethyl ester was accompanied by decarboxylation and aromatization, yielding... 

For planar unsaturated and aromatic molecules, many MO calculations have been made by treating the a and n electrons separately. It is assumed that the o orbitals can be treated as localized bonds and the calculations involve only the tt electrons. The first such calculations were made by Hiickel such calculations are often called Hiickel molecular orbital (HMO) calculations Because electron-electron repulsions are either neglected or averaged out in the HMO method, another approach, the self-consistent field (SCF), or Hartree-Fock (HF), method, was devised. Although these methods give many useful results for planar unsaturated and aromatic molecules, they are often unsuccessful for other molecules it would obviously be better if all electrons, both a and it, could be included in the calculations. The development of modem computers has now made this possible. Many such calculations have been made" using a number of methods, among them an extension of the Hiickel method (EHMO) and the application of the SCF method to all valence electrons. ... 

Recently Shihabi and Bishop (93) described a refinement in the preparation of a stable substrate and demonstrated the feasibility monitoring the reaction kinetically. This procedure has been evaluated by Lifton et. al. (9 ), who found that this method correlated well (r 0.914) with the copper soap-lipase method of Dirstine. They concluded that the method was rapid (less than 5 min. per sample), accurate, precise and linear over a clinically useful range. Its simplicity allows its application as an emergency procedure. Attempts to use this assay for urine lipase activity were unsuccessful. 

Obviously, the advantages of this new synthetic method are i) valence isomerization can be performed under very mild conditions and ii) due to the fairly strong acidity of the bridgehead hydrogens of a bicyclobutane moiety, some substituents can be introduced regioselectively. Nevertheless, one serious disadvantage of this synthesis is the limitation of its applicability Thus, the formation of the precursor bicyclobutane derivatives is limited only to 46 and 56, and many attempts to prepare bicyclobutane precursors from other thiapyran derivatives have been unsuccessful so far. 

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