Primary losses

The watts input is the sum of the friction and windage losses, core loss and no-load primary loss (/njR )- The sum of friction, windage and core losses is obtained by... 

Primary Loss of Coolant AccidenI A leak in (he primary (DZO) cooling system. ... 

MAFRAM divides the agricultural environment into two main zones, which are the on- and off-farm zones. Six compartments (air, water, soil, sediment, aboveground plants, and roots) are included in on- and off-farm zones. The MAFRAM output includes the intercompartmental transport and transfer rates, the primary loss mechanisms, chemical concentration, amount, residence time, and the rank of risk in each compartment. 

With 4,4-diacyl triafulvenes two principal fragmentation pathways have been observed5 s In 4-aroyl-4-acetyl triafulvenes 241 the molecular ion is followed by a fragment ion of probable structure 242 arising from primary loss of (CvI R), which surprisingly has incorporated a CH2 unit from the acetyl group and the exo-cyclic aryl residue. It is not unlikely that the (C7H6R)-residue corresponds to a substituted tropyl radical due to its well-known formation from electron-impact of benzylic precursors. 

The Level II calculation includes the half-lives of 17 h in air, 170 h in water, 550 h in soil and 1700 h in sediment. No reaction is included for suspended sediment or fish. The input of 1000 kg/h results in an overall fugacity of 6 x 10 6 Pa, which is about 20% of the Level I value. The concentrations and amounts in each medium are thus about 20% of the Level I values. The relative mass distribution is identical to Level I. The primary loss mechanism is reaction in air, which accounts for 802 kg/h or 80.2% of the input. Most of the remainder is lost by advective outflow. The water, soil and sediment loss processes are unimportant largely because so little of the benzene is present in these media, but also... 

If the primary loss mechanism of atmospheric reaction is accepted as having a 17h half-life, the D value is 1.6 x 109 mol/Pah. For any other process to compete with this would require a value of at least 108 mol/Pah. This is achieved by advection (4 x 10s), but the other processes range in D value from 19 (advection in bottom sediment) to 1.5 x 10s (reaction in water) and are thus a factor of over 100 or less. The implication is that the water reaction rate constant would have to be increased 100-fold to become significant. The soil rate constant would require an increase by 104 and the sediment by 10s. These are inconceivably large numbers corresponding to very short half-lives, thus the actual values of the rate constants in these media are relatively unimportant in this context. They need not be known accurately. The most sensitive quantity is clearly the atmospheric reaction rate. 

The third row shows the fate if discharge is to soil. The amount in soil is 67460 kg, reflecting an overall 87 h residence time. The rate of reaction in soil is only 85 kg/h and there is no advection thus, the primary loss mechanism is transfer to air (T31) at a rate of 905 kg/h, with a relatively minor 10 kg/h to water by run-off. The net result is that the air concentrations are similar to those for air discharge and the soil acts only as a reservoir. The soil concentration of 3.75 x 10 3 g/m3 or 2.5 x HP3 pg/g or 2.5 ng/g is controlled almost entirely by the rate at which the benzene can evaporate. 

The primary loss mechanism of soil reaction has a D value of 1.03 x 1011 thus, for any other process to compete with this would require a D value of at least 1010 mol/Pa h. The next largest D values are 3.19 x 109 and 2.53 x 109 for reaction and advection in water, which are about a factor of 30 smaller. Only if the water advection or reaction rates are increased by about this factor will these processes become significant. As pH increases, reaction in, and advection from, water increase in importance. 

Several lif-triazoles have been observed to undergo a primary loss of nitrogen M — 28) in the mass spectrum. - The isomeric 2H-triazoles do not undergo this fragmentation, and this appears to provide a simple means of distinguishing H- and 2. -isomers. However, w-triazole can eliminate nitrogen from both the H- and the 2H-tautomer. ... 

The fragmentation of dibenzothiophene sulfoxide resembles that of dibenzothiophene rather than that of the sulfone. This is due to primary loss of 0 to give the dibenzothiophene ion, which is the strongest feature of the spectrum. Much of the breakdown which follows is due to that of the dibenzothiophene ion. There are, however, some aspects of sulfone behavior, notably the formation of the dibenzofuran ion (14) by the loss of sulfur from the rearranged molecular ion (13). ... 

The dithiazolidine (44) <77CCC2672> and dioxazolidine (45) <69JOC2269> are ring systems in which the fragmentation pattern, has been used to affirm the structures. In the latter case the absence of CO2 primary loss allows differentiation from the isomeric oxadiazolidone (46) co-product. A new technique, e.g. the neutralization-reionization mass spectrometry (NRMS) in combination with... 

Most of the A2-triazolines undergo primary loss of a molecule of nitrogen in the mass spectrum and usually do not show a molecular ion peak. Initially, an M - 28 peak is observed at higher temperatures (250°C) for triazolinonor-bornanes, but at lower temperatures (150°C), by increasing the sample pressure, an M + 1 peak is obtained. The intensity ratio, M + 1/M - 28, is... 

The processes by which ions are lost in the stratosphere and the troposphere are not completely understood due to a sparcity of laboratory data on ionic recombination. It is most likely that mutual neutralization of cluster ions [reaction (9)] will be the primary loss mechanism in the upper stratosphere, with the process of collision-enhanced (ternary) recombination becoming increasingly important at lower altitudes (Sect. 3.2.5). In the presence of aerosols (liquid or solid droplets), loss of both positive and negative cluster ions from the gas phase can occur by attachment to the aerosol surfaces 85 86) (see Sect. 4). 

Anodic oxidation in alkaline methanol of A-benzyl-A - methyl-ethanolamine (51) produces three main products81 two of these are 3-methyl-2-phenyloxazolidine (52) and 3-benzyl-oxazolidine (53). The primary loss of an electron occurs probably from the nitrogen... 

The light output of a LED is given by the injection current and the radiative efficiency and is governed by two primary loss mechanisms. A large fraction of the recombination at room temperature is by non-radiative transitions at defects (see Section 8.3.5). The thermal quenching of the photoluminescence is lower in the alloys than in... 

The mass spectrometric behavior of the isomeric 2-oxo-2H- and 4-oxo-4 -6,7,8,9-tetrahydropyrido[l,2-<3]pyrimidines was studied under electron-impact induced polarization (97RCM664). The molecular ion of the 2-OXO-2H isomer appeared to be much more stable than that of the 4-oxo-4 isomer. The fragmentation of the molecular ion (M+) of the 4-oxo-4 isomer is related mostly to the saturated piperidine ring, whereas that of the 2-oxo-2H isomer is much more selective, the only significant process is the primary loss of a CO molecule from the pyrimidinone ring via contraction of the ring. Electrospray ionization quadrupole ion-trap mass spectrometric characterization of risperidon (11) was presented and a possible mechanism for the observed fragmentation pattern was... 

The persistence of sulfur mustard in soil depends on the soil type, pH, moisture content, and whether the agent is at the soil surface or buried. Small (1984) reported that HD applied to the soil surfaee volatilized and would likely be the main route of HD loss (half-life about 30 min). However, if the soil was wet, hydrolysis would be the primary loss pathway. When sprayed onto soil, a vesieant action may persist for about 2 weeks but when the agent continually leaks into the soil vesicant action may be present after 3 years (DA, 1974). Rosenblatt et al. (1995) state that the persistenee of sulfur mustard in soil is due to the formation of oligomerie degradation products that coat... 

Fig. 4. Tropospheric Gincentrations of CH3CCI3 Measured in Remote Locations during Summer 1979. Calculated concentrations for various postulated atmospheric lifetimes. Assumed hydroxyl sinks of equal magnitude in both hemispheres primary losses in tropics.

Fig. 7. IMumal trace of the OO, QONOj and HOQ oKtcenttatians for 4 altitudes in the stratosphere 24, 30, 36 and 44 km. Note the rapid but easily measured decay of QO fallowing sunset with considerably steeper decay rates at the lower altitudes reflecting the thermolecular behavior of the primary loss reaction QO + NOj + M - QONOj + M. In the altitude interval above 40 km, the dominant diurnal b vior is the day-idght exchange between QO and HOQ. Results are from reference 6 by Ko and Sze.

Trichloroethane tends to be stable in the atmosphere and is transported considerable distances. The rate of degradation is increased by the presence of chlorine radicals and nitrogen oxides. In water, its primary loss is by evaporation into the atmosphere. At a vapor pressure of 23mmHg at 25°C, 1,1,2-trichloroethane is expected to exist almost entirely in the vapor phase in the ambient atmosphere. It will gradually degrade by reaction with photohemically produced hydroxyl radicals. 

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