Control of Structure in Conventional Friction Stir Welds through a Kinematic Theory of Metal Flow

In friction stir welding (FSW), a rotating pin is translated along a weld seam so as to stir the sides of the seam together. Metal is prevented from flowing up the pin, which would result in plowing/cutting instead of welding, by a shoulder on the pin. In conventional FSW, the weld metal rests on an "anvil", which supports the heavy "plunge" load on the tool. In this study, both embedded tungsten wires along and copper plating on the faying surfaces were used to trace the flow of AA2219 weld metal around the C-FSW tool. The effect of tool rotational speed, travel speed, plunge load, and pin thread pitch on the resulting weld metal flow was evaluated. Plan, longitudinal, and transverse section x-ray radiographs were examined to trace the metal flow paths. The results are interpreted in terms of a kinematic theory of metal flow in FSW

Effect of betaine on growth performance and carcass composition of Alentejano pig breed.

The aim of this work was to evaluate the effect of fattening diets supplemented with betaine on growth performances and carcass characteristics of Alentejano pigs. Sixteen Alentejano pigs sexually neutralized, with a initial body weight (BW) of 36.3 kg, allocated to open-air individual pens (3m2), were divided into two experimental groups: Group C (n=8) consuming a commercial diet with 150 g/kg crude protein and 13.0 MJ digestible energy; and group CB (n=8) consuming the same diet supplemented with betaine (1g/kg). The diets were restrictively offered at 85% estimated ad libitum consumption. All pigs had free access to fresh water. Diet refusals were measured daily and pigs were weighed weekly. At 100 kg BW, pigs were submitted to a 24 h fasting period and killed. Carcass weight, backfat thickness and Longissimus muscle area were determined. The left side half carcass was submitted to commercial cuts according to the Portuguese norm and their weights recorded. No significant differences between treatments were detected in feed intake (297.3 vs. 286.5 kg), average daily gain (472 vs. 480g) and feed:gain (4.66 vs. 4.51). Hot carcass weight (82.2 vs. 83.6 kg), backfat thickness (5.0 vs. 5.3 cm), Longissimus muscle area (21.9 vs. 21.2 cm2) and weights of commercial cuts of the half carcass were also not significantly affected by betaine supplementation

Betaine supplementation vs. exercise: effects on glucose, protein, urea and lipid plasma parameters from Alentejano pigs.

Swine, due to their physiologic and anatomical similarities to humans, are considered as good models for cholesterol metabolism studies. The Alentejano (AL) pig is a breed from the south of Portugal with a higher lipogenic activity than European breeds. The present study aimed to investigate the effects of betaine (a methyl donor and an osmoprotectant, with contradictory effects on backfat thickness) supplementation and of exercise in some plasma parameters of AL pigs. Weaned female and male AL pigs were castrated, allocated to individual pens and fed a commercial (C) diet offered at 85% of ad libitum. The pigs were slaughtered (~100 kg BW) in 3 groups: Group C (n=6), consuming the C diet; Group CB (n=8), consuming the C diet with betaine (1g/kg); and Group CE (n=5), consuming also the C diet, but with access to an exercise area. Fasting plasma concentrations of glucose, protein, urea, triacylglycerols, phospholipids, total and LDL- and HDL-cholesterol were determined. When compared to C and CE pigs, CB pigs presented higher concentrations (P<0.05) of triacylglycerols, phospholipids, cholesterol and lipoprotein cholesterol. As to CE pigs, they presented lower total cholesterol (P=0.08) and higher HDL-cholesterol and HDL:total cholesterol ratio (P<0.05) than C ones. These data suggest that betaine increases dyslipidemia. Furthermore, exercise had a beneficial effect on plasma cholesterol levels and on the cholesterol deposition in adipose tissues and muscles of CE pigs (lower than the ones observed in the subcutaneous fat and m. semimembranosus of C and CB pigs – preliminary data)

The “montado”: determinant factor affecting the carcass characteristics and the quality of dry cured hams of Alentejano pig

The objective of this study was to assess the effect of the finishing system (under montanheira or with commercial feed) on carcass characteristics and dry cured-ham of Alentejano pigs. 24 pigs were fattening until 130 kg LW under montanheira and 24 pigs were fattening with commercial feed. Carcasses of pigs fattened under the montanheira system were slightly heavy (98,38 vs 96,13 kg), with significantly higher (P>0,01) dressing percentage (79,55% vs 78,11%), backfat thickness (6,09 vs 5,34 cm), percentage of fatty cuts (32,06% vs 30,44%) and weight (21,92 vs 19,77 kg) and percentage of adipose tissue (51,65% vs 47,71%). Percentage of lean cuts (50,03% vs 49,07%), bone cuts (19,53% vs 18,87%), weight (14,91 vs 13,77 kg) and percentage of lean (36,04% vs 32,54%), lean:bone (3,21 vs 3,01) and lean:fat (0,76 vs 0,63) ratios were significantly higher in pigs fed commercial feed. The content of ether extract in lean+fat was significantly higher (63,7% vs 60,41%), in pigs fattened under the montanheira system, while the content of crude protein (7,57% vs 8,41%) was significantly higher in pigs fed commercial feed. Energy retained was higher in pigs finished under montanheira (231,7 vs 217,0 Mcal). The dry cured hams from pigs fattened on acorns were more mono-unsaturated and less poly-unsaturated, especially on subcutaneous fat. It can be concluded that the fattening on pasture and acorns under the oak canopy is considered to be crucial for the quality of the raw material and meat products, as dry cured-ham

Desenvolvimento do tecido adiposo e muscular em suínos de raça Alentejana

To study the effects of slaughter weight on adipose and muscular tissues development of Alentejano hogs thirty animals were used. With an average live weight of 35 kg, pigs were allocated in individual pens at outdoor and fed a commercial diet (15% CP and 3100 Kcal ED/kg) offered at 85% Ad Libitum. Pigs were sequentially slaughtered in groups (n=5) with an average live weight of 40, 70,80, 90, 100 and 110 kg. After carcass chilling at 5º C for 24 h flare fat was weighed and subcutaneous backfat thickness and loin eye area were recorded at 10-11 ribs, last rib and 3-4 lombar vertebras. Flare fat increased significantly (P<0,01) with the increase of slaughter weight: 1,26, 2,08, 3,22, 3,36, 3,68 e 4,02 Kg, respectively at 40, 70, 80, 90, 100 e 110 Kg. Subcutaneous back fat thickness also increased strongly with the increase of slaughter weight: 1,56, 3,21, 4,12, 5,10, 5,41 and 5,38 cm, respectively at 40, 70, 80, 90, 100 e 110 Kg. Between 90 and 110 kg averages were similar. The area of Longissimus dorsi increased slightly (15,49 to 20,36 cm2) with the increase of slaughter weight. The results suggested that Alentejano pig breed have a limited genetic potential for lean gain and a high capacity for fat deposition

Impact of acorn flour on gluten-free dough rheology properties

Gluten is a fundamental ingredient in breadmaking, since is responsible for the viscoelastic behaviour of the dough. The lack of gluten has a critical e ect on gluten-free dough, leading to less cohesive and less elastic doughs, and its replacement represents a challenge for bakery industry. However, dough rheology can be improved combining di erent ingredients with structural capacity and taking advantage from their interactions. Although acorn flour was used to bake bread even before Romans, nowadays is an underexploited resource. It presents good nutritional characteristics, particularly high fibre content and is naturally gluten free. The aim of this study was to use acorn flour as a gluten-free ingredient to improve dough rheology, following also market trends of sustainability and fibre-rich ingredients. Doughs were prepared with buckwheat and rice flours, potato starch and hydroxypropylmethylcellulose. Two levels of acorn flour (23% and 35% w/w) were tested and compared with control formulation. Micro-doughLAB was used to study mixing and pasting properties. Doughs were characterised using small amplitude oscillatory measurements (SAOS), with a controlled stress rheometer, and regarding Texture Profile Analysis (TPA) by a texturometer. Dietary fibre content and its soluble and insoluble fractions were also evaluated on the developed breads. Acorn flour showed promising technological properties as food ingredient for gluten-free baking (improved firmness, cohesiveness and viscoelasticity of the fermented dough), being an important fibre sourceinfo:eu-repo/semantics/publishedVersio

Probiotic potential of indigenous yeasts isolated during the fermentation of table olives from Northeast of Portugal

The aim of this study was to evaluate the probiotic potential of 16 yeast strains previously isolated during the natural fermentation of table olives Negrinha de Freixo cultivar, in relation to enzymatic activities; ability to grow at 37 °C; antimicrobial activity; autoaggregation capacity; antioxidant activity and survival in gastrointestinal tract conditions. The highest antioxidant activity was observed for Saccharomyces cerevisiae, similar to the reference strain S. boulardii. Candida norvegica 7A and Galactomyces reessii 34A showed antifungal ability to the pathogenic microorganism Cryptococcus neoformans. Regarding the autoaggregation capacity, S. cerevisiae 15A, C. tropicalis 1A and C. norvegica 7A showed > 80% after 24 h. Pichia guilliermondii 25A and C. norvegica 7A were the most resistant to the simulated digestive conditions, similar to the reference strain (S. boulardii). Thus, these results suggest that some yeast strains involved in the fermentation of table olives have probiotic potential. Industrial relevance In this study, we highlight the probiotic potential of yeast microbiota usually found in green table olives. These yeast strains could be used as culture starters for the development of new functional products.info:eu-repo/semantics/publishedVersio

Four-wave mixing using polarization grating induced thermal grating in liquids exhibiting circular dichroism

A novel four-wave mixing technique for the detection of circular dichroism in optically active liquid samples is demonstrated. When two cross-polarized laser beams are crossed at a small angle in a circular dichroic liquid a weak thermal grating is produced with a phase depending on the sign of the circular dichroism. The authors show that the polarization of one of the beams can be modified to allow coherent interference with an intensity-grating induced thermal grating. A probe beam scattering from the composite grating results in a signal that reveals the sign and magnitude of the circular dichroism. The use of this technique to optimize the signal-to-noise ratio in the presence of scattered light and laser intensity noise is discussed

Swinging Atwood's Machine: Experimental and Theoretical Studies

A Swinging Atwood Machine (SAM) is built and some experimental results concerning its dynamic behaviour are presented. Experiments clearly show that pulleys play a role in the motion of the pendulum, since they can rotate and have non-negligible radii and masses. Equations of motion must therefore take into account the inertial momentum of the pulleys, as well as the winding of the rope around them. Their influence is compared to previous studies. A preliminary discussion of the role of dissipation is included. The theoretical behaviour of the system with pulleys is illustrated numerically, and the relevance of different parameters is highlighted. Finally, the integrability of the dynamic system is studied, the main result being that the Machine with pulleys is non-integrable. The status of the results on integrability of the pulley-less Machine is also recalled.Comment: 37 page