The power transfer and frequency detuning in a gyrotron

A rigorous small-signal theory of the power transfer and the associated complex frequency shift of a gyrotron oscillator is developed. Experimental results taken from a 28 GHz gyrotron operating in the TE₀₂ mode, (measurements made at UKAEA, Culham Laboratory) and theoretical results on the frequency detuning are compared. It is seen that the frequency detuning increases as the frequency of the electric field approaches that of the cyclotron frequency. The imaginary component of the theoretical complex frequency detuning is shown to indicate the region of operation of the device and this is also compared with that obtained experimentally.     

SCALE‐UP and FIELD TEST of the VACUUM/STEAM/VACUUM SURFACE INTERVENTION PROCESS FOR POULTRY1

The Vacuum/Steam/Vacuum surface intervention pilot plant processor was scaled up to a mobile unit that can be transported to close proximity of chicken processing plants. After several modifications to the mandrel that supports the broiler carcass in the treatment chamber to minimize mechanical damage, the unit was capable of 1.1 log cfu/mL kill of inoculated Listeria innocua and 1.4 log cfu/mL kill of inoculated E. coli K‐12. Field tests achieved 1.4 log kill of E. coli and 1.2 log kill of Campylobacter on freshly processed chicken using 3 cycles and 138C saturated steam. But, there was extensive mechanical damage. the mandrel was modified in the Eastern Regional Research Center pilot plant to eliminate the mechanical damage. With mechanical damage eliminated, the bacteria kill was 1.1–1.5 log of inoculated E. coli K‐12 with a total process time of 1.1 s.     

MEASUREMENT OF FLUID FOOD VISCOSITY USING MICROFABRICATED RADIO FREQUENCY COILS

We report on the use and applicability of microfabricated radio frequency (r.f.) coils for viscosity measurements of fluid foods. The viscosity of fluid milk and milklike products was measured using nuclear magnetic resonance imaging based on microfabricated r.f. coils coupled to in‐line tubing with an inner diameter of 1.4 × 10^‐3 m. The fluid's apparent viscosity ranged from 0.002 to 0.08 Pa·s. The magnetic resonance‐based measurements were limited in shear rate range because of the small size of the coil. Magnetic resonance‐based measurements from 2 to 15 s^‐1 were obtained and were equivalent to off‐line rotational rheometry.     

Biomass distribution and nitrate assimilation in response to N supply for Vitis vinifera L. cv. Cabernet Sauvignon on five Vitis rootstock genotypes

Effects of nitrogen (N) supply on biomass distribution as well as N effects on NO₃"assimilation, were examined in two-year-old graftlings of Vitis vinifera L. cv. Cabernet Sauvignon on five rootstocks. Whole-plant biomass in all graftlings more than doubled with increased N supply in solution from 0.25 to 8 mM. Whole plant biomass was also affected by rootstock genotype, but to a lesser extent than by N supply. Biomass allocation to roots declined with increased N supply for all stock-scion combinations, but the magnitude of that response varied with rootstock genotype. Nitrate reductase activity (NRA) in leaves increased with increased N supply for all stock-scion combinations, whereas root NRA increased only up to 1 mM N supply, dropping markedly with additional N. NRA in leaves was one to two orders of magnitude higher than NRA in roots - a difference that increased steadily with increased N supply. By implication, grapevine leaves have a much higher capacity for NO₃^-_- reduction than do grapevine roots, and any contribution by roots to whole-vine NO₃^-_- assimilation declines even further as NO₃^-_- availability increases.     

Analysis of the anthocyanin composition of Cabernet Sauvignon and Portugieser wines provides an objective assessment of the grape varieties

This paper presents data on the ratios of acetylated to p -coumaroylated anthocyanins of authentic and unadulterated trade samples of 71 Cabernet Sauvignon and 40 Portugieser winegrape varieties. The relative peak areas of nine characterising anthocyanins were determined by a standardised and validated HPLC-method. The 95%-confidence ranges calculated from the data ranged from 2.9 to 5.7 for the Cabernet Sauvignon wines and from 0.7 to 1.7 for the Portugieser wines. The rule that individual anthocyanin components are normally distributed was also confirmed for wines vinified from Gamay and Kadarka (Gamza) grape varieties.     

THERMAL INACTIVATION OF PEA FLOUR LIPOXYGENASE

Lipoxygenase (LOX) was determined in pea flour (9.6% moisture) samples which had been exposed to 90–130°C for 5–45 min, and in crude aqueous extracts (5%; pH 6.7) of previously unheated pea flour which had been exposed to 40–80°C for 5–30 min. The rate of thermal inactivation of pea LOX was shown to follow first-order reaction kinetics. The rate constants, k(min^?1), ranged from 0.005 to 0.252 for the flour, and from 0.068 to 0.267 (60–80°C) for the crude extract. The respective thermodynamic values were: for the energy of activation (E_a), 126.2 and 64.6 kJmole^?1; for the enthalpy of activation (ΔH^?), 123.1 and 61.8 kJmole^?1; for the free energy of activation (Δ^?), 118.0 and 101.4 kJmole^?1. The greater thermostability of LOX in the pea flour under dry-heat conditions, and the observed differences in the E_a, ΔH^? and ΔS^? values, may be accounted for by its possible complexation with other macromolecules and by the structure of the water surrounding the native enzyme.     

ABSORPTION OF VANADIUM, NICKEL, ALUMINUM AND MOLYBDENUM BY SWISS CHARD GROWN ON SOIL AMENDED WITH OIL FLY ASH OR BOTTOM ASH

An appreciable percentage of electric power is generated by oil-fired power plants. The ash resulting from such plants is typically very high in elements such as vanadium, nickel, aluminum and molybdenum. Oil bottom ash and fly ash when disposed or fly ash fallout from such power plants could result in absorption of such metals by agricultural crops. Swiss chard (Beta vulgaris L.) was grown in potted soils amended with oil bottom ash and fly ash at 2% and 1% (w/w), respectively. The crop absorbed significantly higher concentrations of each of the metals as compared to those in the control crop grown on soil alone. Higher levels of the ashes in soil resulted in phytotoxicity to the swiss chard .     

EFFECT OF ELECTRICAL STIMULATION ON KILLING SALMONELLA TYPHIMURIUM IN VARIOUS SALT SOLUTIONS

Electrical stimulation was evaluated as a method to kill Salmonella typhimurium in various salt solutions at different concentration . Salmonella typhimurium at 2 × 10⁵ CFU/ml was treated at 22–24C for 60 min in each salt solution using electricity at 10 mA/cm² current, 1 kHz frequency, and 50% duty cycle. Samples taken at various times were serially diluted, plated on tryptic soy agar and xylose lysine desoxycholate agar, and incubated at 37C for 18–24 h. To detect injured cells, samples were also pre-enriched in buffered peptone water at 37C for 4–5h before being plated. Results indicated all salmonellae were electrically killed at 5 min in NaCl, at 30 min in NaNO₃, and at 45 min in NaC₂H₃O₂ at 0.15 and 0.015 M concentrations. Salmonellae were also killed at 45 min in Na₃PO₄ and at 60 min in Na₂CO₃ at 0.0015 M concentration by electricity in combination with high pH .     

Pre-Chill Spray of Chicken Carcasses to Reduce Salmonella typhimurium

A test chamber was designed and constructed and prechill chicken carcasses inoculated with Salmonella typhimurium were treated in it. They were sprayed with tap water, 0.85% sodium chloride (NaCl), 5% or 10% trisodium phosphate (TSP), 5% or 10% sodium bisulfate (SBS), 0.1% cetylpyridinium chloride (CPC), or 1% lactic acids (LAC) at 207, 345 or 827 kPa pressure for either 30 or 90 sec exposure time. Samples were taken from carcass wash water to determine the most probable number of Salmonella. Compared to tap water spraying, 0.85% NaCl spraying did not significantly reduce Salmonella. The greatest reductions of S. typhimurium, by 10% TSP, 10% SBS, 0.1% CPC or 1% LAC spraying, were 3.7, 2.4, 1.6 or 1.6 log in 90 sec treatments, respectively.     

QUALITY OF MEAT PRODUCTS DURING REFRIGERATED AND ULTRA-CHILLED STORAGE

Standard domestic refrigerators store food between 1 and 5C (33.8–41F). A manufacturer recently developed a refrigerator capable of storing food in the “ultra‐chilled region” (?3 to ?7C) and claimed that storage of fresh meat in this region better maintains quality. To understand quality in terms of chemical reaction rates, microbial growth and texture and flavor changes, three common consumer meat products – steak, ground beef patty and salmon – were stored for a selected period of time, as determined by microbial testing, in five refrigerator models with different environmental conditions (constant temperature and temperature fluctuation). At the end of the storage period, consumer panelists assessed the quality of the cooked samples by ranking them according to preference. In addition, instruments were used to measure the color and shear cutting force (for steak only) of each sample. Results from the consumer Ranking R‐Index Test indicate that panelists preferred samples stored under or near ultra‐chilled conditions rather than samples stored under standard refrigerated conditions. The ultra‐chilled samples not only had higher panelist rankings and more favorable comments, but also had lower microbial aerobic plate counts. The instrument readings, however, highly varied and did not correlate well with sensory data.