Hot Sheet Metal Forming Strategies for High-Strength Aluminum Alloys: A Review—Fundamentals and Applications

In the past decade, aluminum alloys have become important structural materials in the automotive industry, thanks to their low density, high strength, high fracture toughness, and good fatigue performance. However, an important limitation of aluminum alloys is their poor formability at room temperature; as a result, numerous studies have been conducted with the aim of developing forming techniques to overcome this and facilitate the forming of more complex-shaped components. Following an overview on the metallurgical background of aluminum alloys, this article reviews recent developments in forming processes for aluminum alloys. The focus is on process variants at room temperature and at higher temperatures and on a new hot forming technique promising considerable improvements in formability. This review summarizes the influence of different process parameters on microstructures and mechanical properties. Particular emphasis is given to process design and to the underlying microstructural phenomena governing the strengthening mechanisms.     

Dynamic aspects of the interaction between microtubules and actin filaments

This paper summarizes observations on the motility and behavior of microtubule asters in polymorphonuclear leukocytes under a variety of experimental conditions. These observations suggest that the location and organization of microtubules is influenced, at least in part, by the activity of the cortical actin network. Aster motility may therefore serve as an indicator of the interaction between the centrosomal microtubules and the cell cortex, and it is speculated that this interaction is of importance for leukocyte translocation.     

Novel Making of Bacterial Cellulose Blended Polymeric Fiber Bandages

Bacterial cellulose (BC) is a very promising biological material. However, at present its utilization is limited by difficulties in shape forming it. In this Communication, it is shown how this can be overcome by blending it with poly(methylmethacrylate) (PMMA) polymer. BC:PMMA fibers are produced by pressurized gyration of blended BC:PMMA solutions. Subsequently, BC:PMMA bandage‐like scaffolds are generated with different blends. The products are investigated to determine their morphological and chemical features. Cell culture and proliferation tests are performed to obtain information on biocompatibility of the scaffolds.     

Stereoisomere Aromastoffe

Zusammenfassung 5-Alkyl-substituierte-Lactone finden sich als aromarelevante Substanzen in tierischen Fetten, aber auch in einigen Früchten. Vor kurzem gelang die erste direkte gaschromatographische Stereodifferenzierung einiger-Lactone an der chiralen Phase Oktakis(3-O-butyryl-2,6-di-O-pentyl)--cyclodextrin [4]. Es wird nun die Enantiomerentrennung der-Lactone bis zu den langkettigen Verbindungen-Trideca-(-C₁₃-)- und-Tetradeca-(-C₁₄-)-lacton aufgezeigt. Über optisch reine Referenzsubstanzen konnte die Elutionsfolge S(I), R(II) der drei wichtigsten aromarelevanten Vertreter dieser-Lactonklasse bestimmt werden. Die Enantiomerenverteilung der C₈-, C₁₀-, C₁₂--Lactone im Wasserdampfdestillat verschiedener Milchprodukte (Milch, Sahne, Butter), in Margarine sowie im Kokosnußfleisch wurde exemplarisch mit Hilfe der HRGC, auch unter Einsatz der multidimensionalen Gaschromatographie (MDGC), untersucht. Es zeigten sich charakteristische, substratspezifische Enantiomerenverteilungen. Die Verteilungsmuster der untersuchten Spiegelbildisomeren aus Kokosnüssen unterschieden sich wesentlich von denen der Milchprodukte.

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Stereoisomeric flavour compoundsXLVII. Direct chirospecific HRGC-analysis of natural -lactones

Summary 5-Alkylated-lactones are well known flavour compounds in animal fats and also some special kinds of fruit. Recently, the first direct stereo-differentiation of chiral-lactones was reported using Oktakis(3-O-butyryl-2,6-di-O-pentyl)--cyclodextrin as the chiral stationary phase [4]. The enantiomeric separation of-lactones up to the long-chain compounds-trideca-(-C_13–) and-tetradeca-(-C_14–)-lactone is demonstrated. By means of optically pure references, the order of elution S(I), R(II) was determined for the important flavour compounds-octa-,-deca-, and-dodecalactone. Analysis of the steam distillate of some dairy products (milk, cream, butter), of margarine and of coconut has been carried out, in order to yield the enantiomeric distribution of C₈-, C₁₀- and C₁₂--lactones by HRGC and multidimensional gas chromatography. Characteristic and product-specific ratios of-lactone enantiomers are detected. The pattern of enantiomeric composition of-octa-,-deca-,-dodecalactone in coconuts differs completely from that found in the dairy products.

     

Parboiled rice: A study about attitude,consumer liking and consumption in São Paulo,Brazil

The consumption of parboiled rice in Brazil is low when compared to milled rice, despite alleged nutritional, convenience and technological benefits. Data collected through a survey with 186 consumers in the city of São Paulo, Brazil, were analysed with the aim of gaining a better understanding of local consumer attitudes towards parboiled rice. Six attitudinal items were assessed as giving a score on a five‐point Likert scale. Cluster analysis was used to identify three segments of respondents with different attitudinal patterns. Subsequently, correspondence analysis revealed associations among clusters and educational level and liking/consumption data. Most consumers did not show an established opinion about the main characteristics of parboiled which indicates a weakness of the product promotion. A positive attitude, as demonstrated by a higher intake of parboiled rice, was a reflection of habit and liking, while a negative attitude seemed to be due to previous negative experience and misconceptions about the product. Copyright © 2007 Society of Chemical Industry     

Genetic parameters for clinical mastitis, somatic cell score, and production in the first three lactations of Swedish holstein cows

Using a mixed linear animal model, genetic parameters were estimated for clinical mastitis (MAST), lactation average somatic cell score (LSCS), and milk production traits in the first 3 lactations of more than 200,000 Swedish Holstein cows with first calving from 1995 to 2000. Heritability estimates for MAST (0.01 to 0.03) were distinctly lower than those for LSCS (0.10 to 0.14) and production traits (0.23 to 0.36). The genetic correlation between MAST and LSCS was high for all lactations (mean 0.70), implying that selection for low LSCS will reduce the incidence of mastitis. Undesirable genetic relationships with production were found for both MAST and LSCS with genetic correlations ranging from 0.01 to 0.45. This emphasizes the need for including udder health traits in the breeding goal. Genetic correlations across lactations for the same trait were positive and high for both MAST (>0.7), LSCS (>0.8), and production traits (>0.9), with the strongest correlations between second and third parity for all traits (>0.9 for udder health traits and close to unity for production traits).