injection molding influence of process parameters on mechanical properties of polypropylene polymer a first study

Abstract This paper shows the first study results of the mechanical characterization of a commercial polypropylene (PP) polymer. Before testing, a mold for injection molding process has been designed and realized. Three different specimens can be produced, for three different tests: tensile, Charpy and Hopkinson bar. In-cavity pressure and temperature sensors are installed next to the molded item to have direct information about process phases. After the description of the instrumentation, the correlation between injection molding input parameters and mechanical behavior of the material has been assessed. In particular, tensile tests have been carried out to investigate the influence of: melt temperature, mold temperature, packing pressure and cooling time. A Design of Experiment plan has been set up to establish the tests to be performed. Results show the influence of mold temperature and holding pressure on mechanical strength of the polymer

Time--Splitting Schemes and Measure Source Terms for a Quasilinear Relaxing System

Several singular limits are investigated in the context of a $2 \times 2$ system arising for instance in the modeling of chromatographic processes. In particular, we focus on the case where the relaxation term and a $L^2$ projection operator are concentrated on a discrete lattice by means of Dirac measures. This formulation allows to study more easily some time-splitting numerical schemes

The antitumor drug, 1,3-bis(2-chloroethyl)-1-nitroso-urea, inactivates human nicotinamide mononucleotide adenylyltransferase.

Nicotinamide mononucleotide (NMN) adenylyltransferase (EC 2.7.7.1) from human placenta is rapidly inactivated by 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU). A similar inactivation is observed with other C- and N-nitroso compounds. The inactivation by BCNU is dependent on incubation time, temperature and BCNU concentration. Protective reagents for -SH groups, dithiothreitol and beta-mercaptoethanol, and the substrate NMN are very effective in protecting NMN adenylyltransferase from BCNU inactivation and in preserving its catalytic properties, while ATP is less efficient. Incubation of BCNU-inactivated and dialysed NMN adenylyltransferase with dithiothreitol results in a partial recovery of the enzymatic activity

Evaluación de metodologías en el etiquetado de eficiencia energética en edificios

El presente trabajo tiene como objetivo el análisis, comparación y evaluación de las metodologías seguidas por las normas actuales sobre el etiquetado de eficiencia energética de edificios entre Argentina y Francia, a fines de establecer convergencias y divergencia. Por un lado, se analizará en Francia, se estudiará el Decreto del 15 de septiembre de 2006: Relativo a la eficiencia energética para los edificios existentes, en venta en Francia metropolitana. Por otro lado, en Argentina, la norma IRAM 11900:2017 - Prestaciones energéticas en viviendas. Método de cálculo. A partir del análisis de las normativas argentina y francesa los resultados no son vinculantes dado que difieren en el proceso metodológico.

A nonlinear model for marble sulphation including surface rugosity: Theoretical and numerical results

We consider an evolution system describing the phenomenon of marble sulphation of a monument, accounting of the surface rugosity. We first prove a local in time well posedness result. Then, stronger assumptions on the data allow us to establish the existence of a global in time solution. Finally, we perform some numerical simulations that illustrate the main feature of the proposed model

miRNA-guided reprogramming of glucose and glutamine metabolism and its impact on cell adhesion/migration during solid tumor progression

MicroRNAs (miRNAs) are small, non-coding RNAs about 22 nucleotides in length that regulate the expression of target genes post-transcriptionally, and are highly involved in cancer progression. They are able to impact a variety of cell processes such as proliferation, apoptosis and differentiation and can consequently control tumor initiation, tumor progression and metastasis formation. miRNAs can regulate, at the same time, metabolic gene expression which, in turn, influences relevant traits of malignancy such as cell adhesion, migration and invasion. Since the interaction between metabolism and adhesion or cell movement has not, to date, been well understood, in this review, we will specifically focus on miRNA alterations that can interfere with some metabolic processes leading to the modulation of cancer cell movement. In addition, we will analyze the signaling pathways connecting metabolism and adhesion/migration, alterations that often affect cancer cell dissemination and metastasis formation

Qué sabemos de los Aguarás: Experiencias de un taller educativo sobre Cánidos Silvestres (Mburucuyá, Corrientes)

Esta actividad de extensión es resultado de proyectos de investigación que forman  parte de la Estación Biológica de Corrientes (EBCo, MACN-CONICET) para difundir información sobre la biología, ecología y comportamiento de tres especies de cánidos silvestres que coexisten en la provincia de Corrientes: el aguará guazú (Chrysocyon brachyurus), y dos especies más pequeñas, conocidas como aguará chaí Cerdocyon thous y Lycalopex gymnocercus. El objetivo principal fue establecer un vínculo que sensibilice a los participantes sobre cuestiones referentes a la conservación de estas especies y su entorno, a partir del papel que cumplen las mismas en su ambiente permitiendo que los participantes puedan respetar, cuidar y valorar sus recursos naturales. El presente trabajo da a conocer una de las primeras experiencias del taller denominado “¿Qué sabemos de los aguarás?... Valorando nuestras especies nativas” realizado en el Colegio N° 613 “Ada Ramona Turconi, extensión áulica de la misma escuela ubicada en la localidad de Mburucuyá (Corrientes), el día 22 de junio 2016, con siete actividades diferentes. Tanto para los participantes como los integrantes del equipo de trabajo el intercambio ha sido positivo, pues mediante el juego, propuesto como herramienta de transferencia de conocimientos científicos, se obtuvo una participación enriquecedora para los responsables del taller, y llena de interés y buena predisposición por parte de la comunidad educativa de dicha institución escolar.

Flow Index: a novel, non-invasive, continuous, quantitative method to evaluate patient inspiratory effort during pressure support ventilation

Background: The evaluation of patient effort is pivotal during pressure support ventilation, but a non-invasive, continuous, quantitative method to assess patient inspiratory effort is still lacking. We hypothesized that the concavity of the inspiratory flow-time waveform could be useful to estimate patient’s inspiratory effort. The purpose of this study was to assess whether the shape of the inspiratory flow, as quantified by a numeric indicator, could be associated with inspiratory effort during pressure support ventilation. Methods: Twenty-four patients in pressure support ventilation were enrolled. A mathematical relationship describing the decay pattern of the inspiratory flow profile was developed. The parameter hypothesized to estimate effort was named Flow Index. Esophageal pressure, airway pressure, airflow, and volume waveforms were recorded at three support levels (maximum, minimum and baseline). The association between Flow Index and reference measures of patient effort (pressure time product and pressure generated by respiratory muscles) was evaluated using linear mixed effects models adjusted for tidal volume, respiratory rate and respiratory rate/tidal volume. Results: Flow Index was different at the three pressure support levels and all group comparisons were statistically significant. In all tested models, Flow Index was independently associated with patient effort (p < 0.001). Flow Index prediction of inspiratory effort agreed with esophageal pressure-based methods. Conclusions: Flow Index is associated with patient inspiratory effort during pressure support ventilation, and may provide potentially useful information for setting inspiratory support and monitoring patient-ventilator interactions