Total volatile bases

A study of the decomposition of raw surimi and a surimi-derived flaked artificial crab stored at 4,10, and 22°C (Hollingworth et ai, 1990) indicated that total volatiles adds and total volatile bases content has the most potential as chemical indicators of decomposition compared to ethanol, cadaverine, putresdne, and histamine content. 

The chemical spoilage indicators of total volatile base nitrogen (TVB-N) and trimethylamine (TMA) first became evident in the chilled samples on storage days 9-13 and not until on day 15 for superchilled pre rigor muscle (both salted and non salted). It could therefore be seen that superchilling had a positive effect on the slowing down the spoilage of the fish. 

Fig. 13.3. Cod fish quality change during storage (according to Ludorff, 1973). Sensory evaluation in total 15 points are given, 5 for visual appearance and 10 for odor, taste and texture Q-value electric resistance of the fish tissue as recorded by a fish tester Q40 quality class S, Q = 30-40 A, Q = 20-30 B, Q20 C and worse TMAO-N trimethylamine oxide-N TVB-N total volatile base-N VRS volatile reducing substances, TMA-N trimethylamine-N...

Vyncke, W., J. Luten, K. BrUnner, and R. Moermans. 1987. Determination of total volatile bases in fish A collaborative study by the West European Fish TechnologistSassosiation (WEFTA). Z. Lebensm. Unters. Forsch. 184 110-114. 

The crystals of halcinonide are not solvated with water, based on a total volatile content of 0.3% obtained by thermal gravimetric analysis, a correct elemental analysis, and a loss-on-drying value of 0.6% (of. section 4.1, Elemental and Inorganic Analyses). 

The widespread use of -hexanc as an extractant in the laboratory creates problems in interpreting concentration readings at low levels. Even with good quality control, it may often be impossible to determine whether to attribute a measured value to the actual levels in a sample or to contamination from M-hexanc in the laboratory environment (Otson et al. 1994). For the most part, -hexane is not a common target analyte from water or soil samples. While data based on ambient air samples or sampling in the air of various workplace or residential environments are more numerous, most EPA regulatory programs rely on bulk measurements of total hydrocarbons or total volatile compounds rather than on measurements of specific compounds such as -hexane (Bishop et al. 1994 DeLuchi 1993). 

An official gas chromatographic method [29] is available from the determination of volatile fatty acids in sewage sludge. This method is based on gas liquid chromatographic estimation with a flame ionization detector, and is applicable up to 2000mg total volatile fatty acids per litre, while the concentrations of individual fatty acids can also be determined. Where this method is not practicable an empirical method based on the spectrophotometric determination of ferric hydroxamates can be used, giving a value for total fatty acids expressed as acetic acid. For control purposes a rapid test is described in which the volatile fatty acids are determined by electrometric titrimetry on the neutralized sludge obtained from the determination of alkalinity. 

The acid-base chemistry of nicotine is now well known and investigations have shown that nicotine in tobacco smoke or in smokeless tobacco prodncts can exist in pH-dependent protonated or nnprotonated free-base forms. In tobacco smoke, only the free-base form can volatilize readily from the smoke particnlate matter to the gas phase, with rapid deposition in the respiratory tract. Using volatility-based analytical measurements, the fraction of nicotine present as the free-base form can be quantitatively determined. For smokeless tobacco products, the situation differs because the tobacco is placed directly in the oral cavity. Hence, the pH of smokeless tobacco prodncts can be measured directly to yield information on the fraction of nicotine available in the nnprotonated free-base form. It is important to characterize the fraction of total nicotine in its conjugate acid-base states as this dramatically affects nicotine bioavailability, because the protonated form is hydrophilic while the nnprotonated free-base form is lipophilic and thus readily diffuses across membranes (Armitage and Turner 1970 Schievelbein et al. 1973). As drug delivery rate and addiction potential are linked (Henningfield and Keenan 1993), increases in delivery rate due to increased free-base levels affect the addiction potential. 

A Biocube system was installed at Patrick Air Force Base in Florida to treat total volatile hydrocarbons (TVFI). Because the Biocube failed to meet initial treatment goals during the test, insufficient data was available to evaluate cost. However, the U.S. Environmental Protection Agency (EPA) estimated that costs could range from 18.66 to 38.06 per kilogram to treat TVH at concentrations of 1000 to 2000 parts per million volume (ppmv) and flow rates of 20 to 40 standard cubic feet per minute (scfm) (D21034U, p. 1). 

During a pilot-scale test in 1993 at the DOD s Davis-Monthan AFB in Tucson, Arizona, a V2C internal combustion engine (ICE) was combined with a S.A.V.E. (spray aeration-vapor extraction) system to treat contaminated soil and groundwater. Based on a 90-day test, the unit operated at 20 to 30 standard cubic feet per minute (scfm) and removed 200 to 300 lb of volatile organics per day from the soil. The cost per pound of total volatile hydrocarbon (TVH) removed decreased from 1.12 to 0.49/lb over the 90-day test. 

At the Davis-Monthan Air Force Base in Arizona, a full-scale system removed over 700,000 lb of total volatile hydrocarbons (TVH) in a period of 21 months. The average cost was 0.14/lb (D17189V, p. 1). Table 1 displays this cost and the average treatment costs from S.A.V.E. demonstrations at other U.S. Department of Defense (DOD) Air Force Bases. According to the vendor, higher costs represent lower influent total volatile hydrocarbon (TVH) concentrations and increased use of supplemental fuel as a result of decreasing extracted hydrocarbon concentrations (D17146K, p. 1). 

Ethanol, Ether and Water Determination in Single-Base Propellants by US Army Munition Command Method T 103.5 entitled Total Volatiles, Gas Chromatographic Method.. The method is described in MIL-STD-2688, 30 June 1971... 

Ethanol -i- Ether, as "Residual Solvent" Determination in Single-Base Propellants (US Ordnance Methods). Determine the percentage of total volatiles (Solvents + Moisture), then of moisture and subtract percentage of moisture from percent of total volatiles to obtain residual solvent... 

This method is used for determining the total volatiles content of either single-base, double-base, or triple-base pro pints... 

Double-base and CMDB powders are loaded on shallow trays which are stacked in dry houses and subjected to a stream of hot air (140°F.) for several days. Results of a typical drying run for a double-base casting powder are shown in Figure 5. Initial drying is quite rapid however, extended cycles are required to get consistent values below the specification maximum, in this case 0.50% total volatiles (TV). 

Discussion on burning rates of rocket double-base proplnts and the possible effects of changes in NG and total volatile content on the burning of jet propulsion tube proplnts) 2)A. Strasser, PATR 1235(1943)(Burning rates detd by closed bomb tests of 3/8 x 1/16" stick double-base proplnts of various compns) 3)A.Strasser, PATR 1474(1944XBuming characteristics of 3/8 stick rocket proplnts) 4)H.S.Seifert et al, AmJourPhysics 15, 122(1947)(Liquid proplnts) 5)G.J. Mueller,... 

Based on the method of internal normalization of peak areas, the percentage composition (less the diethyl ether solvent shown as the initial large component in Figures 1 and 2) of odor concentrates was estimated. The average composition of samples of odor isolates from individual preparations as well as from several different preparations of the same type—i.e., concurrent or noncurrent—was determined on the basis of all preparations which could be compared on a fair analytical basis (same gas chromatographic detector, column, and conditions). These results were then combined (traps plus distillate) to provide the rough estimations shown in Table IV. These data represent the best estimation of the composition of the total volatile odor concentrates from each processing method studied. 

Sasahara,T., H. Kato, A. Saito, M. Nishimura, and M. Egashira. 2007. Development of a ppb-level sensor based on catalytic combustion for total volatile organic compounds in indoor air. Sens. Actuat. B B126 536-543. 

The proportion of the respective population of heterotrophs and nitrihers varies with the ratio of the influent BOD5 to influent TKN as shown in Table 15.4. Based on this table, the concentrations of the respective species may be calculated. Also, the design total volatile solids (MLVSS, for mixed liquor volatile suspended solids) vary depending upon the type of activated sludge process being used. Table 15.5 shows some representative values. Note that the air supplied is measured at normal air temperatures. 

The volatilization or pseudo-boiling point temperature and the corresponding enthalpies of decomposition and volatilization of all the systems examined as a function of total pressure are reported in Table 2. The variation in the enthalpy of volatilization as a function of pressure is generally less than 7%. The Ti-02 system (Fig. 8) shows an anomalous rise in with pressure. When the AI-N2 system is raised from 0.1 to 10 atm, the Al(g) product condenses and the species of decomposition are no longer in their standard states. When the assigned enthalpy is increased further so that the A1 returns to the gaseous state, an enthalpy of volatilization based on this new assigned enthalpy can be defined. The... 

The preparation of the parent tiimethylenoimine from y-bromo-propylamine is extremely inefficient a mixture cf ozetidine and the dimeric bishomopiperazine is obtained, and in the most recent report of this reaction the total yield of crude steam-volatile base ranged from 6 to 26%.w The first-order rate constant for the cyclization of... 

Based on the volatiles composition shown above calculations were performed at 10 v-% O2, air-to-fuel ratio A of 1.2, a bed temperature of 850°C, a residence time of 3 s, and a fuel-nitrogen content of 1 w-%. In accordance to the results of Wartha et al [18] HCN was considered in the volatiles of the biomass fuel. The ratio of HCN to the total volatile N was assumed 0.2. Singe the composition of the volatiles and the ratio of HCN and NH3 are uncertain, this parameter was varied in a wide range. To reduce the amount of calculations standard conditions were defined. Coming from these each parameter was varied one by one as indicated in Table 2. 

The method of zonation was applied to the energy and material conservation equations. Based on centered finite difTerence approximations, this method can transform three partial differential equations in radial distance and time to ordinary differential equations in time only. Following this, the ordinary differential equations were solved by using Crank-Nicholson algorithm. On the basis of this, the volumetric fluxes of those tar-phase and total volatile phase components were integrated with time by using in roved Euler method to evaluate overall pyrolysis product yields, and afterwards the gas yield can be deduced. 

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