Modeling of morphology evolution in the injection molding process of thermoplastic polymers

A thorough analysis of the effect of operative conditions of injection molding process oil the morphology distribution inside the obtained moldings is performed, with particular reference to semi-crystal line polymers. The paper is divided into two parts: in the first part, the state of the art on the subject is outlined and discussed; in the second part, an example of the characterization required for a satisfactorily understanding and description of the phenomena is presented, starting from material characterization, passing through the monitoring of the process cycle and arriving to a deep analysis of morphology distribution inside the moldings. In particular, fully characterized injection molding tests are presented using an isotactic polypropylene, previously carefully characterized as far as most of properties of interest. The effects of both injection flow rate and mold temperature are analyzed. The resulting moldings morphology (in terms of distribution of crystallinity degree, molecular orientation and crystals structure and dimensions) are analyzed by adopting different experimental techniques (optical, electronic and atomic force microscopy, IR and WAXS analysis).Final morphological characteristics of the samples are compared with the predictions of a simulation code developed at University of Salerno for the simulation of the injection molding process

A branch-and-cut algorithm for the Orienteering Arc Routing Problem

[EN] In arc routing problems, customers are located on arcs, and routes of minimum cost have to be identified. In the Orienteering Arc Routing Problem (OARP),in addition to a set of regular customers that have to be serviced, a set of potential customers is available. From this latter set, customers have to be chosen on the basis of an associated profit. The objective is to find a route servicing the customers which maximize the total profit collected while satisfying a given time limit on the route.In this paper, we describe large families of facet-inducing inequalities for the OARP and present a branch-and-cut algorithm for its solution. The exact algorithm embeds a procedure which builds a heuristic solution to the OARP on the basis of the information provided by the solution of the linear relaxation. Extensive computational experiments over different sets of OARP instances show that the exact algorithm is capable of solving to optimality large instances, with up to 2000 vertices and 14,000 arcs, within 1 h and often within a few minutes.Authors want to thank two anonymous referees for their careful reading of the original paper and their many valuable comments and suggestions that have helped to improve the paper. Angel Corberan, Isaac Plana and Jose M. Sanchis wish to thank the Ministerio de Economia y Competitividad of Spain (MTM2012-36163-006-02) and the Generalitat Valenciana (project GVPR-OMETE02013-049) for its support.Archetti, C.; Corberán, A.; Plana, I.; Sanchís Llopis, JM.; Speranza, M. (2016). A branch-and-cut algorithm for the Orienteering Arc Routing Problem. Computers & Operations Research. 66:95-104. https://doi.org/10.1016/j.cor.2015.08.003S951046

Nota introductoria al cálculo del capital económico a riesgo en organizaciones con dos unidades de negocio

This introductory note discusses the calculation of value at risk (VaR) of a company with two departments. The problem is analysed under two scenarios and compared. Firstly, the problem is studied under the assumption of normality of the distribution and, secondly, the calculation is made assuming fat tails using extreme value theory

Nota introductoria al cálculo del capital económico a riesgo en organizaciones con dos unidades de negocio

This introductory note discusses the calculation of value at risk (VaR) of a company with two departments. The problem is analysed under two scenarios and compared. Firstly, the problem is studied under the assumption of normality of the distribution and, secondly, the calculation is made assuming fat tails using extreme value theory

Chirality effects on the IRMPD spectra of basket resorcinarene/nucleoside complexes

The IRMPD spectra of the ESI-formed proton-bound complexes of the R,R,R,R- and S,S,S,S-enantiomers of a bis(diamido)-bridged basket resorcin[4]arene (R and S) with cytosine (1), cytidine (2), and cytarabine (3) were measured in the region 2800– 3600 cm1. Comparison of the IRMPD spectra with the corresponding ONIOM (B3LYP/6-31(d):UFF)-calculated absorption frequencies allowed the assessment of the vibrational modes that are responsible for the observed spectroscopic features. All of the complexes investigated, apart from [R·H·3]+, showed similar IRMPD spectra, which points to similar structural and conformational landscapes. Their IRMPD spectra agree with the formation of several isomeric structures in the ESI source, wherein the N(3)-protonated guest establishes noncovalent interactions with the host amidocarbonyl groups that are either oriented inside the host cavity or outside it between one of the bridged side-chains and the upper aromatic nucleus. The IRMPD spectrum of the [R·H·3]+ complex was clearly different from the others. This difference is attributed to the effect of intramolecular hydrogen bonding interactions between the C(2’)-OH group and the aglycone oxygen atom of the nucleosidic guest upon repulsive interactions between the same oxygen atom and the aromatic rings of the host

Immobilization of γ-Glutamyl Transpeptidase from Equine Kidney for the Synthesis of kokumi Compounds

\u3b3-Glutamyl transpeptidase from equine kidney (ekGGT, E.C. 2.3.2.2) is an intrinsic membrane enzyme which transfers the \u3b3-glutamyl moiety of glutathione to amino acids and peptides, thus producing \u3b3-glutamyl derivatives. An immobilization study of ekGGT was carried out with the aim to develop a robust biocatalyst for the synthesis of \u3b3-glutamyl amino acids which are known as kokumi compounds. Heterofunctional octyl-glyoxyl-agarose resulted in a high immobilization yield and activity recovery (93 % and 88 %, respectively). Immobilized ekGGT retained more than 95 % activity under reaction conditions (Tris-HCl, pH 9, 0.05 M) after 6 days, whereas the residual activity after 6 reaction cycles (18 days) was 85 %. The synthesis of \u3b3-glutamylmethionine catalyzed by octyl-glyoxyl-agarose-ekGGT afforded the product in 42 % yield (101 mg). The immobilized ekGGT was characterized by Raman spectroscopy. The immobilization protocol developed for ekGGT could be of general applicability to membrane proteins

Immobilization of γ-Glutamyl Transpeptidase from Equine Kidney for the Synthesis of Kokumi Compounds

γ-Glutamyl transpeptidase from equine kidney (ekGGT, E.C. 2.3.2.2) is an intrinsic membrane enzyme which transfers the γ-glutamyl moiety of glutathione to amino acids and peptides, thus producing γ-glutamyl derivatives. An immobilization study of ekGGT was carried out with the aim to develop a robust biocatalyst for the synthesis of γ-glutamyl amino acids which are known as kokumi compounds. Heterofunctional octyl-glyoxyl-agarose resulted in a high immobilization yield and activity recovery (93 % and 88 %, respectively). Immobilized ekGGT retained more than 95 % activity under reaction conditions (Tris-HCl, pH 9, 0.05 M) after 6 days, whereas the residual activity after 6 reaction cycles (18 days) was 85 %. The synthesis of γ-glutamylmethionine catalyzed by octyl-glyoxyl-agarose-ekGGT afforded the product in 42 % yield (101 mg). The immobilized ekGGT was characterized by Raman spectroscopy. The immobilization protocol developed for ekGGT could be of general applicability to membrane proteins

Tethyan versus Iberian extension during the Cretaceous period in the Eastern Iberian Peninsula: insights from magnetic fabrics

This work investigates how anisotropy of magnetic susceptibility (AMS) recorded the strain related to the Early Cretaceous extensional processes in synrift sediments of the Maestrat basin (eastern Spain). Forty-two sites, distributed throughout the Lower Cretaceous sequence with dominant gentle dips, were sampled. Minerals contributing to the AMS are mainly phyllosilicates. The parallelism between magnetic and sedimentary foliation seems to indicate that a primary (synsedimentary and early diagenetic) magnetic fabric was preserved at 84% of sites. Consequently, preferred orientations of magnetic lineations are interpreted to record the effect of extensional processes coeval with sedimentation and diagenesis during this period. At these 35 sites, two main magnetic lineation orientations are found, delimiting two large domains: a NE–SW orientation prevailing in the NW sector of the basin (parallel to the extension direction of the Iberian basin), and NW–SE to NNW–SSE orientations to the SE (parallel to the extension direction controlling the western Tethys margin). Directional variability demonstrates that the Maestrat basin is located at the boundary between two domains (Iberian and Tethyan) undergoing different plate-scale extensional processes. The subsequent Cenozoic tectonic inversion affected the synsedimentary magnetic fabrics at only a few sites at the borders of the basin, where compressive features are more developed

Neural processing of emotions in traumatized children treated with eye movement desensitization and reprocessing therapy: a hdEEG study

Eye Movement Desensitization and Reprocessing (EMDR) therapy has been proven efficacious in restoring affective regulation in Post-Traumatic Stress Disorder (PTSD) patients. However, its effectiveness on emotion processing in children with complex trauma has yet to be explored. High density Electroencephalography (hdEEG) was used to investigate the effects of EMDR on brain responses to adults\u27 emotions on children with histories of early maltreatment. Ten school-aged children were examined before (T0) and within one month after the conclusion of EMDR (T1). hdEEGs were recorded while children passively viewed angry, afraid, happy, and neutral faces. Clinical scales were administered at the same time. Correlation analyses were performed to detect brain regions whose activity was linked to children\u27s traumatic symptom-related and emotional-adaptive problem scores. In all four conditions, hdEEG showed similar significantly higher activity on the right medial prefrontal and fronto-temporal limbic regions at T0, shifting towards the left medial and superior temporal regions at T1. Moreover, significant correlations were found between clinical scales and the same regions whose activity significantly differed between pre- and post-treatment. These preliminary results demonstrate that, after EMDR, children suffering from complex trauma show increased activity in areas implicated in high-order cognitive processing when passively viewing pictures of emotional expressions. These changes are associated with the decrease of depressive and traumatic symptoms, and with the improvement of emotional-adaptive functioning over time