Functional check test for high-speed milling centres of up to five axes

This paper offers a system for checking three or five axes high-speed machining centres by milling a sample sphere pattern. Using the right choice of toolpath, it is possible to check and compare the performance which the centre is capable of following. The main features under study here are ease of use and the great amount of information that can be drawn regarding high-speed machine performances, including the geometrical precision of the machine and tool setup for the chosen machining conditions.     

The Experiences of Retired Managers Acting as Volunteers in an Entrepreneurial Mentoring Organization

Volunteering in later life is an important way of staying involved in one’s community and engaging in a meaningful activity that has a positive impact on others. Previous research has mainly described the antecedents and consequences of volunteering; the process and experiences associated with performing this role has been less studied. The aim of this study was to assess the positive and negative experiences of older managers involved in an entrepreneurial mentoring organization. Fourteen older male volunteers were administered a semi-structured interview and the data obtained were analyzed thematically. The themes that emerged were the importance of the final result as a filter to assess the whole mentoring experience, the mentor-mentee bond, and the self-attribution of successes and failures. These themes were discussed using the generativity theory as a framework to understand the experiences of older adults keen to pass on their skills and knowledge to a younger generation.     

Modelling the effect of pH and pectin concentration on the PEF inactivation of Salmonella enterica serovar Typhimurium by using the Monte Carlo simulation

The effects of pH (3.5, 4 and 4.5), electric field (15, 25, 35 and 40 kV/cm) and pectin concentration (0.1, 0.3 and 0.6%) on the inactivation kinetics of Salmonella typhimurium in an orange juice-milk beverage treated by pulsed electric fields (PEF) were studied. A secondary model, based on Weibull distribution function, was used together with a Monte Carlo simulation to establish the most influential factors on the final number of Salmonella cells after PEF treatment. The Monte Carlo simulation can be a useful and practical tool for the industry to predict how the process parameters and product formulation will influence the food safety of the product.     

Dispersion and reaction sintering of alumina–titania mixtures

Alumina–aluminium titanate (A–AT) composites are typically produced either by mixing the alumina matrix powder with already formed aluminium titanate or by reaction sintering of alumina and titania powders. Reaction-sintered materials usually exhibit limited final density and extensive microcracking. This paper describes the preparation of A–AT nanocomposites by slip casting and reaction sintering, using aqueous suspensions of submicrometre-sized alumina and nanometre-sized titania at a respective weight ratio of 87:13, which is typical for plasma-sprayed coatings. The colloidal stability of aqueous suspensions of the two individual powders and of their respective mixtures was determined first, measuring zeta potential and rheological behaviour as a function of deflocculant content and sonication time. The bimodal distribution yielded green relative densities of up to 70% of theoretical density. Dynamic and static sintering studies showed that aluminium titanate had already formed at 1400 °C.     

Mate (<Emphasis Type="Italic">Ilex paraguariensis</Emphasis>) as dietary additive for broilers: performance and oxidative stability of meat

Aqueous extract of mate (dried leaves of Ilex paraguariensis) added to drinking water for broilers for the last 14 days prior to slaughter did not affect performance at 25 days of age, but improved oxidative stability of the chicken meat. Oxidative stability of precooked breast meat made from control meat (CON) and from meat of broilers raised on water with mate added was investigated during chill storage for up to 7 days. The use of mate showed no influence on the content of lipids in chicken breast meat; however, lipid oxidation measured as thiobarbituric acid–reactive substances (TBARS) was significantly lower for meat from broilers raised on water with mate extracts in different concentrations (MA0.1, MA0.5, and MA1.0 corresponding to 0.1, 0.5, and 1.0% of mate dried leaves). The relative effect was largest at 1 day of storage with more than 50% reduction on TBARS; the result was still significant after 3 days, but almost vanished after 7 days, when oxidative rancidity was very high in all samples. In meat from broilers raised on water with mate extract, vitamin E was protected during cooking, although in the very rancid meat balls at 7 days of storage, the protection almost disappeared. Nevertheless, mate can be an interesting natural alternative to be used in chicken diets to improve lipid stability of the meat.     

Analysis of the Deformation Behavior of Magnesium-Rare Earth Alloys Mg-2 pct Mn-1 pct Rare Earth and Mg-5 pct Y-4 pct Rare Earth by In Situ Energy-Dispersive X-ray Synchrotron Diffraction and Elasto-Plastic Self-Consistent Modeling

The deformation behavior of the Mg-RE alloys ME21 and WE54 was investigated. Although both alloys contain rare earth elements, which alter and weaken the texture, the flow curves of the alloys deviate significantly, especially in uniaxial compression test. Apart from the higher strength of the WE54 alloy, the compression flow curve does not exhibit the typical sigmoidal shape, which is associated with tension twinning. However, optical microscopy, X-ray texture measurements, and EBSD analysis reveal the activity of tension twinning. The combination of in situ energy-dispersive X-ray synchrotron diffraction and EPSC modeling was used to analyze these differences. The investigation reveals that twin propagation is decelerated in the WE54 alloy, which requires a change of the twinning scheme from the ‘finite initial fraction’ to the ‘continuity’ assumption. Furthermore, an enhanced activity of the 〈c+a〉 pyramidal slip system was observed in case of the WE54 alloy.     

Balloon extraction from complex comic books using edge detection and histogram scoring

Extracting balloons has been a challenge in digital comics, in particular for complex comic books. In fact, current algorithms are seemingly adequate for simple comics, but not for complex ones. This paper proposes an algorithm based on the Sobel operator plus a modified flood fill operator to identify and extract balloons in comic book pages. Unlike other approaches, our algorithm applies to any sort of comics, no matter they are simple or complex comics, without making any assumptions regarding the line continuity of the image, color depth of the image, orientation of the text, and language. Experimental results show that our algorithm significantly improves the rate of correctly detected balloons, and simultaneously decreases the number of false positives, when compared to other algorithms.