Direct Entry

Visual assurance of cleanliness is best achieved by direct entry and hand cleaning, by one means or another, of the interior of equipment. However, vessel entry is one of the most hazardous activities in the chemical industry and should be avoided whenever possible. Potential problems include  

A vessel large enough for entry will almost certainly come under OSHA s definition of a confined space. Regulations and permits for such work are covered in Sections 4.5.1 and 7.1.4. 

Vessel entry may appear to be a simple and direct approach to a stubborn cleaning problem. However, in light of the hazards noted above, it should not be attempted without careful planning and supervision. A generalized check list should include 

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Influent water enters one end of the pressure vessel and travels longitudinally down the length of the vessel in the feed transport layer. Direct entry into the permeate transport layer is precluded by sealing this layer at each end of the roll. As the water travels in a longitudinal direction, some of it passes in radially through the membrane into the permeate transport layer. Once in the transport layer, the purified water flows spirally into the center collection tube and exits the vessel at each end. The concentrated feed continues along the feed transport material and exits the vessel on the opposite end from which it entered. 

The user logs into the system with valid user id and password credentials from any computer connected to the network. The instantaneous access of the user to the centralized database enables direct entry of the data into a centralized database, whether with LAN, WAN, or VPN. Remote data entry... 

Direct entry of alumina adjuvants through the skin may occur by the use of therapeutic vaccines, with a resultant transient uptake of aluminium in the brain (Redhead et al., 1992). The injection of talc (magnesium silicate)-containing drugs intended for oral consumption has been shown to induce progressive pulmonary fibrosis in drug abusers (Pare etal., 1989). 

In electronic data packages used in held studies, there are some electronic data that are directly entered by the held investigator (FI) and some that are generated by the program (e.g., dates and times). Both types of raw data need to be verified by QA personnel, who should check not only directly entered data, but also computer-entered data. In order to conduct a thorough data audit, QA should determine which data are direct entry and which are automatic. 

Consideration should be given to what happens to the form once it is returned. Form design will be affected depending upon whether it is intended to serve as a direct entry document (i.e., the data elements closely match the data entry screens), or whether a transcription document will be used. 

It is possible that this compound (and perhaps related compounds) acts by direct entry into the diencephalon. 

Although this synthesis provides the most direct entry into the twistane polycyclic structure, the adequate balance between the problem of framework construction and the subsequent functional group manipulations, required by the "principle of maximum simplicity", is missed. However, the synthesis represents without doubt an outstanding contribution to the synthesis of polycyclic non-natural products. 

A direct entry to valuable enantiomerically enriched tetrahydropyridines and azadec-alinones 118 was provided by the Rueping group in 2008 [71], A mixture of enamines... 

A direct entry into hydroazulenes has also been achieved through [3-I-4] cycloaddition chemistry, using the more elaborate cyclic vinyldiazoacetate 62 and acetoxybuta-dienes 63 and 64 (Scheme 14.6) [80]. The tandem process is facile with the trons-iso-mer of butadiene 64 leading to the [3-r4] cycloadduct 68 in 67% yield. Reaction with cis-acetoxybutadiene 63, however, forms the isolable cis-divinylcyclopropane 65 (80% yield), which required forcing conditions to initiate the Cope rearrangement to form 67 [80]. 

Encouraged by the recent work on the conversion of 3-trimethylstannylfuran or 156 to 3-acylfurans, the palladium-catalyzed reaction was carried out by Yang between 137 and benzoyl chloride, yielding 158 (Scheme 33). This partial acylation therefore provided a direct entry to unsymmetrical 3,4-disubstituted fufans. A fitting example to demonstrate such an application was the conversion of 158 to 159 as shown in Scheme 33. ... 

Since the migrating group retains its configuration, the use of enantiomerically enriched oximes provides a direct entry to enantiomerically pure lactams. These lactams may be used as a key building block for the synthesis of diverse compounds. Westermann and Gedrath applied this strategy to the stereoselective synthesis of enantiomerically pure o-.a-disubstituted a-amino acids (equation 135), bicyclic lactams and the spirocyclic framework of Histrionicotoxins (equation 136). 

Reduction of labor due to the use of computers is becoming a trend. Many concrete producers take advantage of the features offered by computers - direct entry of customer orders, automatic delivery docket printing, and remote workstations - to reduce personnel. Customer orders can be taken and entered at the head office using a remote terminal. 

A direct entry into phenanthridinone and benzophenanthridinone skeletons was also disclosed by the formal [4 + 2] cycloaddition of N-vinyl isocyanates 232 and benzyne (89JOC4019). On the basis of this cycloaddi-... 

Under the second type of real time data acquisition, we have direct entry methods where essentially you are incorporating an actual terminal into the sensory evaluation booth itself. The electronic terminal would include a data entry keyboard as well as a display screen for receiving results and prompts from the microcomputer (4). This technique has been developed in our laboratories and we feel that it holds tremendous promise in terms of the versatility and the viability for expanding into different areas of sensory evaluation. 

Huckett, B., Ariatti, M., Hawtrey, A.O. (1990). Evidence for targeted gene transfer by receptor-mediated endocytosis. Stable expression following insulin-directed entry of NEO into HepG2 cells. Biochem. Pharm., 40, 253-263. 

Databases are resources that contain environmental information in various fields. Databases may be available from government or educational institutions online or by inquiry, or may be available from commercial establishments on-line or CD-ROM. Some databases are essentially electronic entries to library catalogs and also provide access to full text articles and/or direct entry to publishers Web sites. 

Figure 6. Block drawing of the pilot installation for the production of trichloromethyl chloroformate by exhaustive photochlorination [39] 1 Dryer for gaseous Cl2 (H2S04 cone.). 2 Safety tank. 3 Thermoregulated immersion-type photochemical reactor. 4 Raschig column. 5 Cl2 detection system (1,2,4-trichlorobenzene). 6 Neutralization tank (20% NaOH). 7 Reservoir of 20% NaOH. 8 Buffer to atmospheric pressure (20% NaOH). 9 Active carbon filter. 10 Reservoir of crude trichloromethyl chloroformate. 11 Buffer to normal atmosphere via CaCl2 filter and direct entry for trichloromethyl chloroformate to be distilled. 12 Distillation flask with Vigreux column. 13 Exit to vacuum pump. 14 Solid NaOH filter before pump. 15 Cooling water alarm linked to power supply of the light source. 16 Medium pressure mercury arc. 17 Heater for distillation apparatus. 18 Magnetic stirrers. /T thermometer /P manometer.

Support-bound isocyanates can be conveniently prepared from carboxylic acids by Curtius degradation. Because the reaction of the intermediate acyl azides with alcohols to yield esters is slow, Curtius degradation can be conducted in the presence of alcohols to yield carbamates directly (Entries 4 and 5, Table 14.8). 

Being restricted to DHAP as the nucleophile, aldol additions will only generate ketoses and derivatives from which aldose isomers may be obtained by biocatalytic ketol isomerization (cf. Sect. 7.1) [306]. For a more direct entry to aldoses the inversion strategy may be followed (Scheme 19) [290] which utilizes monoprotected dialdehydes. After aldolization and stereoselective chemical or enzymatic ketone reduction, the remaining masked aldehyde function is deprotected to provide the free aldose. Further examples of the directed, stereodivergent synthesis of sugars and related compounds such as aza- or thiosugars are collected in Sect. 7. 

A direct entry to the quadricyclene series has been gained through photoisomerization of bicyclo [2.2.1 ]heptadienes. Bicyclo [2.2.1 ]hepta-dien-2,3-dicarboxylic acid (Formula 194), undergoes light-induced valence tautomerization to Formula 195 (75). The parent quadricyclene 196 has been prepared by direct irradiation of bicyclo [2.2. l]heptadiene... 

The reaction of carbenoids with aromatic systems was first reported by Buchner and coworkers in the 1890s.6 The reaction offers a direct entry to cycloheptatrienes and has been used to synthesize tropones, tropolones and azulenes.6 Neither the thermal nor copper-catalyzed reactions, however, proceed in good yield. The problems associated with these transformations were clearly demonstrated in a recent reexamination of die thermal decomposition of ethyl diazoacetate in excess anisole (137).129 A careful analysis of the reaction mixture revealed the presence of seven components (138-144) in 34% overall yield (Scheme 29). The cycloheptatrienes (138M142) were considered to be formed by cyclopropanation followed by electrocyclic ring opening of the resulting norcaradienes. A mixture of products arose because the cyclopropanation was not regioselective and, also, the initially formed cycloheptatrienes were labile under the reaction conditions. 

Decomposition of l-diazo-4-arylbutan-2-ones offers a direct entry to bicyclo[5.3.0]decatrienones and the approach has been extensively used by Scott and coworkers to synthesize substituted azulenes.137 Respectable yields were obtained with copper catalysis,137 but a more recent study24 showed that rho-dium(ll) acetate was much more effective, generating bicyclo[5.3.0]decatrienones (154) under mild conditions in excess of 90% yield (Scheme 34). The cycloheptatrienes (154) were acid labile and on treatment with TFA rearranged cleanly to 2-tetralones (155), presumably via norcaradiene intermediates (156). Substituents on the aromatic ring exerted considerable effect on the course of the reaction. With m-methoxy-substituted systems the 2-tetralone was directly formed. Thus, it appeared that rearrangement of (156) to (154) was kinetically favored, but under acidic conditions or with appropriate functionality, equilibration to the 2-tetralone (155) occurred. 

Primary routes of entry of toxicants to the human body are dermal, gastrointestinal, and respiratory. Methods for studying these different routes are numerous, but they are perhaps best developed for the study of dermal absorption because this route is subject to more direct methodology, whereas methods for studying respiratory or gastrointestinal absorption require more highly specialized instrumentation. Additional routes encountered in experimental studies include intraperitoneal, intramuscular, and subcutaneous routes. When direct entry into the circulatory system is desired, intravenous (IV) or intra-arterial injections can be used to bypass the absorption phase. Information from this more direct route of entry (e.g., IV) should, however, be used in addition to data from the extravascular route of interest to adequately assess the true extent of absorption of a toxicant. 

Computerized physician provider order entry (CPOE) is defined as the computer system that allows direct entry of medical orders by the physician or person with appropriate licensure and privileges to do so. Directly entering orders into a computer has the benefit of reducing errors by minimizing the errors caused by handwritten orders, but even a greater benefit is realized when the combination of CPOE and clinical decision-support tools is implemented together. 

The normal reaction of tertiary phosphines is to replace metal-coordinated carbonyl groups (Section III,E,1) or, less commonly, to form adducts with P—>Si bonds (Section III,D). In special cases, however, cleavage of the Si-metal bond may occur directly (entries 63, 66, 66a, and 67) the manganese derivative is discussed further in Section... 

When ketones are symmetrical, a single isomer is obtained, indicative of total asymmetric induction at C3. In the case of unsymmetrical ketones, two isomers are formed that may be separated by LC on silica gel. An important feature is that (3-lactams are easily formed from formaldimine BSMA offering for the first time a direct entry to C4-unsubstituted (3-lactam ring (monobactams).228,260 In contrast, its monosilylated counterpart, under the form of its trimer, leads only to traces of the expected (3-lactam.259 This demonstrates the great utility of the bissilylmethyl group for preparing (3-lactams. 

One death in an adult female due to acute intravasation of barium sulfate during a barium enema was found in the literature. Direct entry of barium sulfate into the circulatory system apparently resulted in cardiorespiratory failure (Cove and Snyder 1974). Acute parenteral administration of barium compounds to animals has resulted in death. Rate of administration, total dose, species, and individual differences are all factors affecting the ability of barium and its compounds to cause death. Major symptoms leading to death are hypokalemia (Jalinski et al. 1967 Roza and Berman 1971 Schott and McArdle 1974), muscle paralysis (Roza and Berman 1971 Schott and McArdle 1974), cardiorespiratory failure (Cove and Snyder 1974 Roza and Berman 1971), and convulsions (Segreti... 

Chiral aryl acetic acids constitute a privileged class of target structures due to their prevalence in bioactive natural products and pharmaceuticals and so, unsurprisingly, they constitute attractive targets for asymmetric synthesis [198]. The face-selective addition of a nucleophile to an aryl alkyl ketene provides a very direct entry for the preparation of such compounds. Although this can be achieved by the use of a chiral nucleophile or acid (cf. Scheme 8.1) [199], catalysis of the addition of an achiral nucleophile is clearly attractive from the standpoint of efficiency. 

Radical cations act both as electrophiles and one-electron oxidants toward nucleophiles (Eberson, 1975 Bard et al, 1976 Eberson et al., 1978a,b Evans and Blount, 1978) as shown in (6), and it is therefore important to find out which factors govern the competitition between these reaction modes. Evans and Blount (1978) measured rate constants and products for a number of [9,10-diphenylanthracene)+ /nucleophile reactions and found that iodide, rhodanide, bromide and cyanide undergo oxidation, whereas nucleophiles that are more difficult to oxidize form a C—Nu bond directly. Entry no. 13 of Table 15 shows non-bonded electron transfer to be feasible for these ions, and the reactions of [perylene]+ with iodide, rhodanide and bromide (entry no. 14) presumably can be classified in the same way. The reaction with chloride ion... 

The direct entry of a nitro group into the oxazole ring (1,3-oxazole) (exclusively at position 5) has only been reported twice [163, 164], Thus, 2-dimethylamino-4-(4-nitrophenyl)-5-nitrooxazole was isolated when 2-dimethylamino-4-phenyloxazole was heated [163] (Scheme 17). 

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