A Design of Experiments Approach Defining the Relationships Between Processing and Microstructure for Ti-6Al-4V

A study was conducted to evaluate the relative significance of input parameters on Ti- 6Al-4V deposits produced by an electron beam free form fabrication process under development at the NASA Langley Research Center. Five input parameters where chosen (beam voltage, beam current, translation speed, wire feed rate, and beam focus), and a design of experiments (DOE) approach was used to develop a set of 16 experiments to evaluate the relative importance of these parameters on the resulting deposits. Both single-bead and multi-bead stacks were fabricated using 16 combinations, and the resulting heights and widths of the stack deposits were measured. The resulting microstructures were also characterized to determine the impact of these parameters on the size of the melt pool and heat affected zone. The relative importance of each input parameter on the height and width of the multi-bead stacks will be discussed.

A Design of Experiments Approach Defining the Relationships Between Processing and Microstructure for Ti-6Al-4V

A study was conducted to evaluate the relative significance of input parameters on Ti-6Al-4V deposits produced by an electron beam freeform fabrication process under development at the NASA Langley Research Center. Five input parameters where chosen (beam voltage, beam current, translation speed, wire feed rate, and beam focus), and a design of experiments (DOE) approach was used to develop a set of 16 experiments to evaluate the relative importance of these parameters on the resulting deposits. Both single-bead and multi-bead stacks were fabricated using 16 combinations, and the resulting heights and widths of the stack deposits were measured. The resulting microstructures were also characterized to determine the impact of these parameters on the size of the melt pool and heat affected zone. The relative importance of each input parameter on the height and width of the multi-bead stacks will be discussed

Qualitative effects of fresh and dried plum ingredients on vacuum-packaged, sliced hams

Boneless ham muscles (Semimembranosus + Adductor) were injected (20% w/w) with a curing brine containing no plum ingredient (control), fresh plum juice concentrate (FP), dried plum juice concentrate (DP), or spray dried plum powder (PP) at 2.5% or 5%. Hams were cooked, vacuum-packaged, stored at \u3c4 °C and evaluated at 2-week intervals over 10 week. Evaluations were performed on sliced product to determine cook loss, vacuum-package purge, Allo-Kramer shear force, 2-thiobarbituric acid-reactive substances (TBARS), proximate analysis, objective color, sensory panel color and sensory attributes. FP, DP and 2.5% PP increased (P \u3c 0.05) cook loss by 2% to 7% depending on treatment and level, but the highest cook loss (17.7%) was observed in hams with 5% PP. Shear force values increased as the level of plum ingredient increased (P \u3c 0.05) from 2.5% to 5%, and the highest shear values were observed in hams containing 5% FP. There were no differences (P \u3e 0.05) in lipid oxidation among treatments as determined by TBARS and sensory evaluation. FP and PP ham color was similar to the control, but DP had a more intense atypical color of cured ham. Minimal changes in physical, chemical and sensory properties were observed during storage of all treatments. © 2009 Elsevier Ltd. All rights reserved

Antioxidant properties of plum concentrates and powder in precooked roast beef to reduce lipid oxidation

Boneless beef roasts (Semimembranosus + Adductor) were injected (20%) with a brine containing (1) no plum ingredient (control), (2) 2.5 or 5% fresh plum juice concentrate (FP), (3) 2.5 or 5% dried plum juice concentrate (DP), or (4) 2.5 or 5% spray dried plum powder (PP). Whole roasts were cooked, vacuum-packaged and stored at \u3c4.0 °C for 10 wk. At 2 wk intervals, evaluations were performed on sliced product to determine vacuum-packaged purge, Allo-Kramer shear force, lipid oxidation (TBARS), color space values, and sensory attributes. All plum ingredients reduced TBARS values and had minimal effects on tenderness, sensory characteristics, color and appearance. Small changes in purge, color values, TBARS and some sensory properties were found during storage. These results indicate that 2.5% FP or DP could be incorporated into precooked beef roasts to reduce lipid oxidation and potentially, warmed-over flavor (WOF). © 2008 Elsevier Ltd. All rights reserved

Avaliação de um modelo de passo invariante na predição da estrutura de um povoamento de Eucalyptus sp. Evaluation of a step invariant model for the prediction of eucalyptus stand structure

O objetivo deste estudo foi avaliar o modelo de distribuição diamétrica de passo invariante proposto por Guimarães (1994) na projeção da produção de um povoamento de Eucalyptus sp., simulando as alterações nas estruturas horizontal e vertical ao longo do tempo. Utilizaram-se dados da primeira rotação de povoamentos de eucalipto híbrido estaca (Eucalyptus grandis x Eucalyptus urophylla), plantados no espaçamento 3,0 x 2,0 m, localizados na região noroeste do Estado da Bahia, provenientes de medições anuais com idade de medição variando entre 25 e 89 meses. Para realizar as prognoses, foram empregados percentis tomados a 50 e 75% da distribuição diamétrica e as alturas correspondentes aos diâmetros nessas posições. Verificou-se que o modelo de projeção é factível e pode ser utilizado com eficiência, já que ocorreram tendências semelhantes entre os volumes prognosticados e os observados nas parcelas. Além disso, devido à sua simplicidade e à compatibilidade dos resultados, recomenda-se a sua utilização na projeção do crescimento e produção de Eucalyptus sp.<br>This study was carried out to evaluate the step-invariant diametric distribution model, proposed by Guimarães (1994), for the prediction of a Eucalyptus stand production, simulating the alterations in the horizontal and vertical structures with time. Data were taken from annual measurements, with measurement age between 25 and 89 months, of the first rotation of hybrid eucalyptus stands (Eucalyptus grandis x Eucalyptus urophylla), plant spacing of 3.0 x 2.0 m, located in the northeast region of State of Bahia. To perform prognoses percentiles were taken at 50 and 75% of the diametric distribution, and the heights corresponding to the diameters in these positions. The prediction model was proved to be feasible for efficient use, since there were similar tendencies between the forecasted and the observed volumes in the plots. Besides, its use in growth and production prediction of Eucalyptus sp. studies is recommended for its simplicity and result compatibility