High-Temperature Creep and Kinetic Demixing in (Co,Mg)O

The creep behavior of fine-grained (Co_0.5Mg_0.5)O and (Co_0.25Mg_0.75)O has been characterized as part of an investigation of kinetic demixing in solid-solution oxides due to a nonhydrostatic stress. (i) For low stresses and small grain sizes, the dominant deformation mechanism for both compositions is diffusional creep limited by the transport of oxygen along grain boundaries. The oxygen grain-boundary diffusivity, D _o ^b is independent of oxygen partial pressure. The values of ω D _o ^b , where ω is the grain-boundary width, that have been determined from the steady-state diffusional creep rates are given by ω D _o ^b =4.7×10⁻⁸ exp[-230 (kJ/mol)/ RT ] (cm³/s) for (Co_0.5Mg_0.5)O in the range 950° to 1200°C and ω D _o ^b =7.4 × 10⁻⁸ exp[-263 (kJ/mol)/ RT ] (cm³/s) for (Co_0.25Mg_0.75)O in the range 1100° to 1250°C. Since oxygen diffusion controls the rate of diffusional creep, kinetic demixing is not observed in deformed samples of either composition. (ii) For high stresses and large grain sizes, the dominant deformation mechanism in both cases is dislocation-climb-controlled creep, where the rate of dislocation climb is controlled by oxygen lattice diffusion. Based on the positive dependence of creep rate on oxygen partial pressure, it is concluded that oxygen diffuses through the lattice by an interstitial mechanism.     

Nutritional Quality of Raw, Precooked and Canned Albacore Tuna (Thunnus alalunga)

The nutritional quality of raw, precooked and canned tuna was assessed by determining the total amino acids, in-vitro protein digestibility, Computed Protein Efficiency Ratio (C-PER), Tetrahymena Relative Protein Value (RPV), and fluorodinitrobenzene reactive lysine, together with selected vitamin and mineral assays. Amino acid composition, in-vitro protein digestibility, C-PER and Tetrahymena RPV remained almost the same for the raw, precooked and canned tuna. The percent retention of FDNB-reactive lysine was 91% for the precooked tuna and 80–85% for canned tuna. Thiamin retention for the canned tuna was about 5%, while niacin and riboflavin ranged from 71–73% and 49–50% respectively. The values for Cu, Fe, K, and Ca were significantly lower in canned tuna.     

RELATIONSHIP BETWEEN THE THERAPISTS' APPROACH-AVOIDANCE REACTIONS TO HOSTILITY AND CLIENT BEHAVIOR IN THERAPY.

USED CONTENT ANALYSIS OF 16 COMPLETE CASES TO DETERMINE THE EFFECT OF THE THERAPISTS' APPROACH AND/OR AVOIDANCE REACTIONS TO HOSTILITY ON THE SUBSEQUENT EXPRESSIONS OF HOSTILITY BY THE CLIENT. THE DIRECTIONALITY OF THE CLIENT'S HOSTILITY AND THE EXPERIENCE LEVEL OF THE THERAPIST WERE ALSO EXAMINED. THE RESULTS INDICATE: (1) THERAPISTS' APPROACH TO HOSTILITY EXPRESSIONS OF THE CLIENT ELICITED FURTHER SUCH EXPRESSIONS, WHILE AVOIDANCE ALWAYS ELICITED NONHOSTILE MATERIAL; (2) CONTRARY TO EXPECTATION THE EFFECTIVENESS OF SUCH ELICITATIONS DID NOT INCREASE, AND THE PROPORTION OF HOSTILITY EXPRESSED IN AN INTERVIEW DECREASED OVER TIME; AND (3) EXPERIENCED THERAPISTS HAD MORE DIFFICULTY THAN INTERN THERAPISTS IN APPROACHING HOSTILITY DIRECTED AT THEMSELVES. THE ADEQUACY OF THE OPERANT CONCEPT OF REINFORCEMENT FOR EXPLAINING VERBAL BEHAVIOR IN THERAPY WAS QUESTIONED. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

MAJOR VOLATILES IN TOASTED CANOLA OIL

Headspace volatiles from 'Alto' canola oil toasted at 240C for 8 min were collected using Tenax ^R TA 60/80 (Supelco Inc., Bellefonte, PA). The Tenax ^R was washed three times with a total of 6 ml of solvent. The solvent extract was concentrated by drying in a hood at room temperature for 6 h. Two μl of concentrated extract were separated on a 30 m DB-1 capillary column (J & W Scientific, Folson, CA) with a Hewlett Packard (HP) 5890A gas chromatograph connected to a HP 5790 mass spectrometer. Volatiles were tentatively identified with a NBS 43 K.1 library by PBM (probability based on matching) search.
Fifty seven peaks were detected by the mass spectrometer. Among those, 50 compounds were tentatively identified. 2-Furancarboxaldehyde, 5-methyl-2-furan carboxaldehyde, 5-(1-methyl ethyl)-1,3-cyclopentadiene, cyclododecane, undecanoic acid, tetradecanoic acid, 1-hexadecanol, hexadecanoic acid, 9-octadecenoic acid, octadecanoic acid, 2,5-dimethyl pyrazine, 3-ethyl-2,5-dimethyl pyrazine, [1,1':3',1"-terphenyl]-1'-ol and [1,1':3',1"-terphenyl]-4'-ol were the major volatile compounds.     

Effects of Elevated CO2 Atmosphere on Storage of Freshwater Crayfish (Pacifastacus leniusculus)

The effects of elevated CO₂ levels on the keeping quality of cooked, freshwater crayfish was investigated. Experiments were conducted using an enriched atmosphere of 80% CO₂:20% air compared to air storage at 4°C. Chemical and microbial changes were correlated with sensory panel evaluations of flavor, odor and texture. After 28 days of storage, the concentrations of ammonia and trimethylamine and total plate counts were lower in crayfish stored under carbon dioxide as compared to samples stored in air. The sensory panel found no significant difference between the odors of the samples stored in CO₂ atmosphere for 21 days and fresh cooked crayfish, whereas samples stored in air were found to have significantly more fishy flavor and odor after 14 days of storage.     

Effectiveness of Chlortetracycline in Combination with Potassium Sorbate or Tetrasodium Ethylenediaminetetraacetate for Preservation of Vacuum Packed Rockfish Fillets

Rockfish fillets were dipped in either distilled deionized water (DDW), a solution of 1% Na₄EDTA plus 5 ppm chlortetracycline (CTC) or 1% K-sorbate plus 5 ppm CTC. After dipping, fliets were vacuum packed and stored at 2°C. Samples were evaluated after 0, 3, 7, 10, 14, and 21 days. The sorbate/CTC group differed less from fresh Filets than did the control (fillets dipped in DDW) for all indices measured (plate count, pH, redox potential, and TMA and NH₃ concentrations). Fillets treated with EDTA/CTC differed to a greater extent from fresh fillets than the sorbate/CTC group but less than the controls. Results were corroborated by sensory analyses which tested for color, flavor and odor. Fish fillets dipped in a solution of 1% K-sorbate plus 5 ppm CTC retained odor and flavor properties of fresh fillets better than the EDTA/CTC treated fillets after 14 days of storage.     

Modified Atmosphere Storage of Rockfish Flllets

A modified atmosphere (MA) of 80% CO₂ and 20% air was effective in extending shelf life of fresh rockfish fillets. Aerobic plate counts and trimethylamine levels were significantly lower (P < 0.1%) for the fillets held in MA compared to those held in air. A decline in surface pH was observed on fillets stored in MA, presumably due to the absorption of CO₂ and its hydration to carbonic acid. Oxidation-reduction potentials suggested a more aerobic environment on fillets stored in MA. There were no significant differences in weight loss between control and MA samples. Sensory evaluations indicated that fillets held under MA were of good quality for at least 13 days of storage.