Structural topology optimization under limit analysis

Structural and Multidisciplinary Optimization - The objective of this paper is to look for structural designs arising from topological optimization procedures that aim at maximizing the loading...     

Bayesian analysis of employee suggestions in a food company

The search for competitive advantages for organizations has been made very complex by technological advancement and the ease of reproduction of resources, such as projects, products, and processes. Even new ideas are likely to be copies. However, the process of generation and conversion of improvements in productive activity is highly complex and little is known about it by firms. Understanding this process may add competitive benefits to any organization. In this paper, we present statistical modeling for data related to the counting of suggestions made by employees at a food company and its viability for improving productivity at the company. This counting, carried out in the years from 2008 through 2011, was performed and encouraged by the company’s managers in order to achieve a general improvement in productivity. Poisson and binomial regression models were considered in analyzing the data under the statistical Bayesian framework. It was shown that the generation of ideas has a significant relationship to the hierarchical position of the employee, his schooling, how long he has been at the company being studied, his age, and training, but these factors do not show significant effects related to the proportions of viable ideas (potential competitive advantages for the organization).     

Combinations of glucose oxidase, α‐amylase and xylanase affect dough properties and bread quality

The objective of this work was to study the effects of the combination of glucose oxidase (Gox), α‐amylase (AM) and xylanase (Xyl) on dough properties and bread quality, applying response surface analysis. Gox improved dough stickiness and bread crumb uniformity, but had a negative effect on specific volume. A positive synergist effect was observed combining Xyl and AM on specific volume and crumb firmness but this synergist effect was negative on crumb uniformity. Using the ‘desirability function’, two optimal formulations for the baking process were obtained. In the first optimisation, the combination of Gox 0.0026, Xyl 0.016 and AM 0.01 g per 100 g of flour will allow to obtain breads with high specific volume and low firmness. Second optimisation (Gox 0.0037, Xyl 0.0089 and AM 0.0105 g per 100 g of flour) will allow to obtain breads with 37% higher specific volume than control and, additionally, with low dough stickiness.     

Prevalence of sensitization to Cupressus sempervirens: a 4-year retrospective study

In the last few years Cupressus sempervirens has been identified as the cause of an increasing number of cases of late winter-early spring pollinosis in Mediterranean countries. We conducted a 4-year retrospective study of a large group of subjects with documented allergic respiratory disease in order to determine the prevalence, clinical significance and annual rate of sensitization to C. sempervirens pollen. Anamnestic data and skin prick tests (SPT) with common aeroallergens and C. sempervirens extract were collected from 1397 subjects (712 male and 685 female) resident in Latium, a region in central Italy, with complaints related to upper- or lower-respiratory-tract disorders or conjunctival disease. Two hundred and forty-three subjects (17.4%) showed positive results to C. sempervirens extract; 47 (19.3%) of them were monosensitized. The annual sensitization rate of SPT positivity to C. sempervirens varied from 7.2% in 1995 to 22% in 1998. All the subjects monosensitized to cypress pollen had symptoms from January through April. Our study suggests that sensitivity to C. sempervirens is responsible for respiratory symptoms in an increasing percentage of subjects. Further studies are needed to determine its frequency at the national level.     

Nondestructive assessing of the aging effects in 2205 duplex stainless steel using thermoelectric power

The microstructural transformation of ferrite into secondary austenite and sigma phase during long term exposure to high-temperatures (650–900 °C) in a 2205 duplex stainless steel has been investigated using the thermoelectric power (TEP) technique, scanning electron microscopy (SEM), Charpy-impact test (CIT), equivalent ferrite and sigma phases content measurements. The possibility of using the TEP coefficient as a nondestructive assessment technique to characterize the aging kinetics of 2205 duplex stainless steel is discussed. Experimental results indicate that TEP coefficient is sensitive to the gradual microstructural transformation of ferrite phase experienced by the 2205 duplex stainless steel during the aging treatments.     

Graphical Tools for an Epistemological Shift. The Contribution of Protoaxonometrical Drawing to the Development of Stonecutting Treatises

In this paper we analyze the graphical methods employed in the stonecutting treatises from that of De l’Orme, published during the sixteenth century, to De La Rue’s Traité de la coupe des pierres, published in 1728. We will deal with the graphical means that made possible an epistemological shift between treatises of the sixteenth century, written for practising stonecutting masons in a period where the subject was covered by a veil of secrecy, which in some specific cases included a very intuitive form of representation, “protoaxonometries”, and eighteenth-century treatises, which show a clear scientific and pedagogical approach to the geometrical problems posed by stonecutting.     

Crack avoidance in steel piston rings through the optimization of process and gas nitriding parameters

This paper describes research into adequately estimating the main variables of a thermochemical gas nitriding process of stainless steel parts for engine components. The paper lays out an experimental strategy for the nitriding process that optimizes a set of variables that have a bearing on the occurrence of nitriding cracks. The results demonstrate that several factors and interactions are relevant in the occurrence of nitriding cracks. The proposed strategy was found to be effective at achieving continuous improvement and stricter control.