A demonstrator for the experimental assessment of the through-process modeling of injection-molded parts made of short-fiber-reinforced polymers

Through process modelling of injection moulded parts is nowadays the industry standard approach to the structural analysis of parts made of short fibre-reinforced polymers. The designer has to face challenging tasks, in order to conduct accurate and reliable analyses. Complex geometries, weld lines and multiple flows make it difficult to transfer results of tests conducted on simple specimens to the assessment of the real parts. We have designed a mould allowing for manufacturing a demonstrator, i.e., a part of sufficiently complex shape, typical of injection-moulded structural parts, allowing for creating different conditions in terms of fibre orientation, presence of weld lines and multiple injection points. The part is designed to be tested under three- or four-point bending conditions. By simulating the test conditions, the designer can compare experimental results with numerical solutions, in order to better understand the potential of the software packages he is using

A demonstrator for the experimental assessment of the through-process modeling of injection-molded parts made of short-fiber-reinforced polymers

Through process modelling of injection moulded parts is nowadays the industry standard approach to the structural analysis of parts made of short fibre-reinforced polymers. The designer has to face challenging tasks, in order to conduct accurate and reliable analyses. Complex geometries, weld lines and multiple flows make it difficult to transfer results of tests conducted on simple specimens to the assessment of the real parts. We have designed a mould allowing for manufacturing a demonstrator, i.e., a part of sufficiently complex shape, typical of injection-moulded structural parts, allowing for creating different conditions in terms of fibre orientation, presence of weld lines and multiple injection points. The part is designed to be tested under three- or four-point bending conditions. By simulating the test conditions, the designer can compare experimental results with numerical solutions, in order to better understand the potential of the software packages he is using

Normative climates of parenthood across Europe : judging voluntary childlessness and working parents

Erworben im Rahmen der Schweizer Nationallizenzen (http://www.nationallizenzen.ch)Past research on gender role attitudes has often focused on individual- rather than country-level explanations. Drawing on European Social Survey data from 21 countries, we examine the effect of societal normative climates (i.e., shared perceptions of others’ attitudes) on personal attitudes towards two non-traditional gender roles: Voluntary childlessness and working full-time while children are young. To detect potential gender differences, we analyse disapproval of men and women separately. Findings reveal that there are strong differences in normative climates across countries, and that people generally perceive more disapproval of women than of men for both behaviours. Most importantly, in countries where a higher share of respondents perceives disapproval of these behaviours, respondents themselves disapprove more strongly – even if they do not believe that others disapprove, and even after controlling for other relevant individual- and country-level characteristics. What is more, the independent effect of normative climate explains most of the differences between countries. This robust finding demonstrates the power of country-level normative climates in explaining individuals’ attitudes and between-country differences in attitudes toward gender roles

Role and regulation of ACC deaminase gene in Sinorhizobium meliloti: Is it a symbiotic, rhizospheric or endophytic gene?

Plant-associated bacteria exhibit a number of different strategies and specific genes allow bacteria to communicate and metabolically interact with plant tissues. Among the genes found in the genomes of plant-associated bacteria, the gene encoding the enzyme 1-aminocyclopropane-1-carboxylate (ACC) deaminase (acdS) is one of the most diffused. This gene is supposed to be involved in the cleaving of plant-produced ACC, the precursor of the plant stress-hormone ethylene toning down the plant response to infection. However, few reports are present on the actual role in rhizobia, one of the most investigated groups of plant-associated bacteria. In particular, still unclear is the origin and the role of acdS in symbiotic competitiveness and on the selective benefit it may confer to plant symbiotic rhizobia. Here we present a phylogenetic and functional analysis of acdS orthologs in the rhizobium model-species Sinorhizobium meliloti. Results showed that acdS orthologs present in S. meliloti pangenome have polyphyletic origin and likely spread through horizontal gene transfer, mediated by mobile genetic elements. When acdS ortholog from AK83 strain was cloned and assayed in S. meliloti 1021 (lacking acdS), no modulation of plant ethylene levels was detected, as well as no increase in fitness for nodule occupancy was found in the acdS-derivative strain compared to the parental one. Surprisingly, AcdS was shown to confer the ability to utilize formamide and some dipeptides as sole nitrogen source. Finally, acdS was shown to be negatively regulated by a putative leucine-responsive regulator (LrpL) located upstream to acdS sequence (acdR). acdS expression was induced by root exudates of both legumes and non-leguminous plants. We conclude that acdS in S. meliloti is not directly related to symbiotic interaction, but it could likely be involved in the rhizospheric colonization or in the endophytic behavior

Experimental characterization of a Polymer Metal Hybrid (PMH) automotive structure under quasi-static, creep, and impact loading

A feasibility study on a short fibre reinforced Polymer Metal Hybrid (PMH) solution of a car’s suspension control arm has been conducted through a simplified demonstrator, representative of the most critical portion of this component. It was injection moulded in two versions: an all composite one and a PMH version, in which the short fibre reinforced composite was over-moulded on to an aluminium insert. The demonstrator underwent quasi- static, creep and impact tests to simulate most of the loading conditions experienced by a suspension arm during its lifetime. The mechanical behaviours of the two demonstrator versions were compared to highlight the differences introduced by the proposed novel PMH solution. In particular, the ductile metal insert ensured the compliance of the PMH demonstrators with the automotive specific safety requirement of avoiding the complete separation at failure, which was successfully obtained in all testing conditions

Molecular and microbiological insights on the enrichment procedures for the isolation of petroleum degrading bacteria and fungi

Autochthonous bioaugmentation, by exploiting the indigenous microorganisms of the contaminated environment to be treated, can represent a successful bioremediation strategy. In this perspective, we have assessed by molecular methods the evolution of bacterial and fungal communities during the selective enrichment on different pollutants of a soil strongly polluted by mixtures of aliphatic and polycyclic hydrocarbons. Three consecutive enrichments were carried out on soil samples from different soil depths (0\u20131, 1\u20132, 2\u20133 m), and analyzed at each step by means of high-throughput sequencing of bacterial and fungal amplicons biomarkers. At the end of the enrichments, bacterial and fungal contaminants degrading strains were isolated and identified in order to (i) compare the composition of enriched communities by culture-dependent and culture-independent molecular methods and to (ii) obtain a collection of hydrocarbon degrading microorganisms potentially exploitable for soil bioremediation. Molecular results highlighted that for both bacteria and fungi the pollutant had a partial shaping effect on the enriched communities, with paraffin creating distinct enriched bacterial community from oil, and polycyclic aromatic hydrocarbons generally overlapping; interestingly neither the soil depth or the enrichment step had significant effects on the composition of the final enriched communities. Molecular analyses well-agreed with culture-dependent analyses in terms of most abundant microbial genera. A total of 95 bacterial and 94 fungal strains were isolated after selective enrichment procedure on different pollutants. On the whole, isolated bacteria where manly ascribed to Pseudomonas genus followed by Sphingobacterium, Bacillus, Stenothrophomonas, Achromobacter, and Serratia. As for fungi, Fusarium was the most abundant genus followed by Trichoderma and Aspergillus. The species comprising more isolates, such as Pseudomonas putida, Achromobacter xylosoxidans and Ochromobactrum anthropi for bacteria, Fusarium oxysporum and Fusarium solani for fungi, were also the dominant OTUs assessed in Illumina