3D BEM-based cooling-channel shape optimization for injection moulding processes

International audienceToday, around 30 % of manufactured plastic goods rely on injection moulding. The cooling time can represents more than 70 % of the injection cycle. Moreover, in order to avoid defects in the manufactured plastic parts, the temperature in the mould must be homogeneous. We propose in this paper a practical methodology to optimize both the position and the shape of the cooling channels in 3D injection moulding processes. For the evaluation of the temperature required both by the objective and the constraint functions, we must solve 3D heat-transfer problems via numerical simulation. We solve the heat-transfer problem using Boundary Element Method (BEM). This yields a reduction of the dimension of the computational space from 3D to 2D,avoiding full 3D remeshing: only the surface of the cooling channels needs to be remeshed at each evaluation required by the optimization algorithm. We propose a general optimization model that attempts at minimizing the desired overall low temperature of the plastic-part surface subject to constraints imposing homogeneity of the temperature. Encouraging preliminary results on two semi-industrial plastic parts show that our optimization methodology is viable

Optimization of 3D Cooling Channels in Injection Molding using DRBEM and Model Reduction

Issu de : ESAFORM 2009 - 12th ESAFORM Conference on material forming, Enschede, THE NETHERLANDS, 27-29 April 2009International audienceToday, around 30% of manufactured plastic goods rely on injection moulding. The cooling time can represent more than 70% of the injection cycle. In this process, heat transfer during the cooling step has a great influence both on the quality of the final parts that are produced, and on the moulding cycle time. In the numerical solution of three-dimensional boundary value problems, the matrix size can be so large that it is beyond a computer capacity to solve it. To overcome this difficulty, we develop an iterative dual reciprocity boundary element method (DRBEM) to solve Poisson’s equation without the need of assembling a matrix. This yields a reduction of the computational space dimension from 3D to 2D, avoiding full 3D remeshing. Only the surface of the cooling channels needs to be remeshed at each evaluation required by the optimisation algorithm. For more efficiency, DRBEM computing results are extracted stored and exploited in order to construct a model with very few degrees of freedom. This approach is based on a model reduction technique known as proper orthogonal (POD) or Karhunen-Loève decompositions. We introduce in this paper a practical methodology to optimise both the position and the shape of the cooling channels in 3D injection moulding processes. First, we propose an implementation of the model reduction in the 3D transient BEM solver. This reduction permits to reduce considerably the computing time required by each direct computation. Secondly, we present an optimisation methodology applied to different injection cooling problems. For example, we can minimize the maximal temperature on the cavity surface subject to a temperature uniformityconstraint. Thirdly, we compare our results obtained by our approach with experimental results to show that our optimisation methodology is viable

CRLF2 over-expression is a poor prognostic marker in children with high risk T-cell acute lymphoblastic leukemia

Pediatric T-ALL patients have a worse outcome compared to BCP-ALL patients and they could benefit from new prognostic marker identification. Alteration of CRLF2 gene, a hallmark correlated with poor outcome in BCP-ALL, has not been reported in T-ALL. We analyzed CRLF2 expression in 212 T-ALL pediatric patients enrolled in AIEOP-BFM ALL2000 study in Italian and German centers. Seventeen out of 120 (14.2%) Italian patients presented CRLF2 mRNA expression 5 times higher than the median (CRLF2-high); they had a significantly inferior event-free survival (41.2%±11.9 vs. 68.9%±4.6, p=0.006) and overall survival (47.1%±12.1 vs. 73.8%±4.3, p=0.009) and an increased cumulative incidence of relapse/resistance (52.9%±12.1 vs. 26.2%±4.3, p=0.007) compared to CRLF2-low patients. The prognostic value of CRLF2 over-expression was validated in the German cohort. Of note, CRLF2 over-expression was associated with poor prognosis in the high risk (HR) subgroup where CRLF2-high patients were more frequently allocated. Interestingly, although in T-ALL CRLF2 protein was localized mainly in the cytoplasm, in CRLF2-high blasts we found a trend towards a stronger TSLP-induced pSTAT5 response, sensitive to the JAK inhibitor Ruxolitinib. In conclusion, CRLF2 over-expression is a poor prognostic marker identifying a subset of HR T-ALL patients that could benefit from alternative therapy, potentially targeting the CRLF2 pathway

Absent B cells, agammaglobulinemia, and hypertrophic cardiomyopathy in folliculin-interacting protein 1 deficiency

Agammaglobulinemia is the most profound primary antibody deficiency that can occur due to an early termination of B-cell development. We here investigated 3 novel patients, including the first known adult, from unrelated families with agammaglobulinemia, recurrent infections, and hypertrophic cardiomyopathy (HCM). Two of them also presented with intermittent or severe chronic neutropenia. We identified homozygous or compound-heterozygous variants in the gene for folliculin interacting protein 1 (FNIP1), leading to loss of the FNIP1 protein. B-cell metabolism, including mitochondria! numbers and activity and phosphatidylinositol 3-kinase/AKT pathway, was impaired. These defects recapitulated the Fnip1(-/-) animal model. Moreover, we identified either uniparental disomy or copy-number variants (CNVs) in 2 patients, expanding the variant spectrum of this novel inborn error of I immunity. The results indicate that FNIP1 deficiency can be caused by complex genetic mechanisms and support the clinical utility of exome sequencing and CNV analysis in patients with broad phenotypes, including agammaglobulinemia and HCM. FNIP1 deficiency is a novel inborn error of immunity characterized by early and severe B-cell development defect, agammaglobulinemia, variable neutropenia, and HCM. Our findings elucidate a functional and relevant role of FNIP1 in B-cell development and metabolism and potentially neutrophil activity.Molecular Technology and Informatics for Personalised Medicine and Healt

Transferências voluntárias e ciclo político-orçamentário no federalismo fiscal brasileiro

RESUMO Este artigo apresenta um estudo econométrico sugerindo que as transferências inter-governamentais no Brasil são significantemente influenciadas por motivações político-partidárias. Diante desse fato estilizado, desenvolve-se uma extensão do modelo de Rogoff (1990) para analisar o efeito dessas transferências politicamente motivadas sobre os equilíbrios eleitoral e fiscal subnacionais. Mostra-se que as transferências politicamente motivadas podem anular o principal aspecto positivo do ciclo político-orçamentário. De fato, essas transferências podem, por um lado, eliminar o ciclo políticoorçamentário, resolvendo o problema de risco moral, mas, por outro lado, elas podem colocar no poder um titular incompetente, gerando um problema de seleção adversa.<br>This article presents an econometric study suggesting that intergovernmental transfers to Brazilian municipalities are strongly partisan motivated. In light of that stylized fact, it develops an extension to Rogoff (1990)'s model to analyze the effect of partisan motivated transfers into sub-national electoral and fiscal equilibria. The main finding is that important partisan transfers may undo the positive selection aspect of political budget cycles. Indeed, partisan transfers may, on one hand, eliminate the political budget cycle, solving a moral hazard problem, but, on the other hand, they may retain an incompetent incumbent in office, bringing about an adverse selection problem

Characterization of some thermal degradation products of datura metel linnaeus

Datura metel Linnaeus, commonly known as Talampunay, is a local plant known for its medicinal purposes and its hallucinogenic properties. Talampunay, specifically its leaves and stems, have various uses such as cigarette for asthma attacks, juice extract for diarrhea, and boiled extracts for boils. From a previous study, the components of leaf extracts were mainly sugars, and small amounts of alkaloids. In this study, smoke condensates were assayed by GC-MS. Matured samples included sun-dried leaves (4-5 inches long) and stem of Datura metel Linnaeus obtained from Batangas. The experimental method involved the use of four different set-ups for collecting smoke condensates. These Set-ups employed variations of both open and closed systems (limited air supply), as well as direct and indirect utilization of flame. The indirect-open system and indirect-closed system were efficient in the collection of smoke condensate. Mass spectra of the products obtained were compared with the mass spectral data available in the Turbo Mass NIST/EPA/NIH Mass Spectral Database. Benzene derivatives, such as phenols and substituted phenols are the predominant compounds detected in the chromatogram obtained for the last three set-ups

Sensitivity analysis of the electrostatic force distance curve using Sobol’s method and design of experiments

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Identification of a Unique Set of Parameter for the Charge Transport Model in LDPE Based on Mathematical Inverse Methods and Experimental Data

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Influence of Metallization on the Barrier Height of Injection of Low Density Polyethylene Using Optimization Algorithm

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