Variations in stir zone and thermomechanically affected zone of dissimilar friction stir weld of AA5083 and AA6082 alloys

Variations in composition, microhardness (in the thermomechanically affected zone) and texture in the tool domain of the dissimilar friction stir weld of AA5083-O and AA6082-T6 alloys were investigated. The contents of the major alloying elements in the weld zones were determined using inductively coupled plasma?atomic emission spectroscopy. It was observed that a slight drop in the content of the alloying elements results from the friction stir welding process with the Mg content being the most affected amongst the major alloying elements in the two alloys. By relating the mass fractions of the major alloying elements in the parent metals of both alloys to those of the stir zone, the relative proportions of the two alloys in the stir zone were estimated with the results showing that at least 60% of the materials in the stir zone are from the retreating side of the weld. It was also revealed that the changes in the hardness profile in the thermomechanically affected zone of the retreating side are predominantly influenced by changes in grain size in that domain. Finally, the investigation further revealed that the texture component in the tool shoulder domain is different from the texture component in the tool pin domain.     

AQUEOUS GARLIC EXTRACT AND MICROBIOLOGICAL QUALITY OF REFRIGERATED POULTRY MEAT

The antibacterial effect of garlic extract (5, 10 and 15%) was investigated on poultry carcasses obtained from a slaughterhouse, stored under refrigeration, and evaluated at selected time intervals. The effect of the garlic extract on the microbial contaminants of the poultry carcass surface – Salmonella, strict and facultative aerobic, mesophilic, and total and fecal coliforms – was evaluated. The garlic extract exhibited a concentration‐dependent reduction of microbial contamination. Garlic extract concentrations of 10 and 15% were the most effective. The bacteriostatic action of garlic extract against mesophilic microbiota can be observed until the third storage day. The count of total and fecal coliforms remained low during the storage period. Chicken feed was the apparent source of Salmonella contamination, and the aqueous garlic extract was not effective against Salmonella.     

Diamond seed consolidation onto untreated silicon substrate

Abstracts are not published in this journal This revised version was published online in November 2006 with corrections to the Cover Date.     

Investigating the physics of disruptions with real-time tomography at JET

As JET is developing and testing operational scenarios for higher fusion performance, an increase in pulse disruptivity is being observed. On a deeper analysis, we find that several radiative phenomena play an active role in determining the outcome of the pulse. The analysis is enabled by the use of real-time tomography based on the bolometer diagnostic. Even though plasma tomography is an inverse problem, we use machine learning to train a forward model that provides the radiation profile directly, based on a single matrix multiplication step. This model is used to investigate radiative phenomena including sawtooth crashes, ELMs and MARFE, and their relationship to the radiated power in different regions of interest. In particular, we use real-time tomography to monitor the core region, and to throw an alarm whenever core radiation exceeds a certain threshold. Our results suggest that this measure alone can anticipate a significant fraction of disruptions in the JET baseline scenario.     

ACEROLA's CLONES OF INDUSTRIAL INTEREST

In order to know which clone of acerola is better for acerola industrialization, we studied the pectin methylesterase (PME) specific activity, pectin content and vitamin C content in five different clones of acerola. The pectin yield varied from 1.37 to 2.99% and the highest content of pectin occurred in clones 3 and 5. Ascorbic acid varied significantly from 1157.5 to 1735.5 mg/100 g of pulp in the five clones. The highest content of vitamin C occurred in clone 4. The PME specific activity varied from 0.79 to 2.92 units g ^?1 /g of pulp and the highest values occurred in clone 2. We also studied the optimum temperature and the optimum pH of this enzyme. Clones 1, 2, 4 and 5 showed optimum temperature at 90C. Clone 3 showed practically the same specific activity at all temperatures studied. Clones 1 and 4 showed an optimum pH of 9.0 and clone numbers 2, 3 and 5 showed a pH optimum at 8.5.     

TEXTURAL CHANGES IN VEGETABLES DURING THERMAL PROCESSING. II. EFFECTS of ACIDIFICATION and SELECTED PRETREATMENTS ON TEXTURE of TURNIPS

The effect of different preprocessing treatments on the softening of vegetable tissues during acidification of turnips at different temperatures was studied. Texture was characterized by the maximum load force in a puncture test. the different preprocessing treatments considered were blanching alone and coupled with vacuum infusion, freezing/thawing and calcium chloride addition. Samples were acidified at different constant temperatures: 20, 50, 70 and 90C. Results were obtained by comparing the softening occurring for all samples and for non-preprocessed turnips. It was found that for low temperature processing the final result was mainly due to the effect of the preprocessing itself on the turnip texture while for high temperature processing the effect of the preprocessing on the tissues sensitivity to the processing was more important. Blanching alone caused greater softening when processing at 70C but lead to a firmer product when coupled with calcium chloride addition or vacuum infusion for processing at 70 and 90C.     

LIQUIFYING COD FISH FRAMES UNDER ACIDIC CONDITIONS WITH A FUNGAL ENZYME

An acidic protease (Newlase A from Rhizopus niveus , Amano) was evaluated as to its ability to reduce viscosity of ground cod fish frames without excessive hydrolysis. Newlase A had an optimal pH of 3.5 and an optimal temperature of 60C with Azocoll as substrate. the enzyme was more stable in the ground fish mixture at pH 3.5 than it was in citrate:phosphate buffer of the same pH. the enzyme hydrolyzed the fish proteins more extensively and decreased the viscosity of the ground fish more between 40–50C over an extended time period than at its optimal temperature of 60C. It is likely that the lower optimal temperature under these conditions is related to its greater stability at the lower temperatures. the energy of activation of the deactivation of the enzyme was 44.5 Kcal per mol-degree. Over a period of 75 min at 45C there was a decrease in viscosity of the ground fish with added enzyme of some two orders of magnitude. After a 3-h incubation, total soluble protein increased from 30% to 48%; the amount of each molecular size fraction produced decreased in the following order: 1–3, < 10, < 1, and 3–10 kdaltons.