Surface modification and characterization of thermoplastic polyurethane

http://www.sciencedirect.com/science/article/B6TWW-4VP4TNJ-1/2/26b1d7dd60ae5bcab0cfe30ac2771c0

Characterization of suspension poly(vinyl chloride) resins and narrow polystyrene standards by size exclusion chromatography with multiple detectors: Online right angle laser-light scattering and differential viscometric detectors

This work reports the utilization of a multi-detector size chromatography for the characterization of poly(vinyl chloride) (PVC) resins prepared by suspension polymerization in the range of temperatures between 21 and 75 °C. The chromatography equipment offers the possibility of analyzing the samples in terms of their absolute molecular mass using a combination of three detectors (TriSEC): right angle light scattering (RALLS), a differential viscometer (DV) and refractive index (RI). The PVC resins were fully characterized concerning the molecular weight distribution (MWD), its dependence with intrinsic viscosity ([eta]) and molecular sizes (radius of gyration, Rg and hydrodynamic radius, Rh). Additionally, it is also presented the characterization of polystyrene narrow standards serving as reference polymers.http://www.sciencedirect.com/science/article/B6TWW-4HHGNVH-4/1/170871b80274a89470f2a790d3ed999

Methodology for Optimization of Polymer Blends Composition

The research of polymer blends, or alloys, has experienced enormous growth in size and sophistication in terms of its scientific base, technology and commercial development (Paul & Bucknall, 2000). As a consequence two very important issues arise: the increased availability of new materials and the need for materials with better performance. Polymer blends are polymer systems originated from the physical mixture of two or more polymers and/or copolymers, without a high degree of chemical reactions between them. To be considered a blend, the compounds should have a concentration above 2% in mass of the second component (Hage & Pessan, 2001; Ihm & White, 1996). However, the commercial viability of new polymers has begun to become increasingly difficult, due to several factors. The advantages of polymer blends lie in the ability to combine existing polymers into new compositions obtaining in this way, materials with specific properties. This strategy allows for savings in research and development of new materials with equivalent properties, as well as versatility, simplicity, relatively low cost (Koning et al., 1998) and faster development time of new materials (Silva, 2011). Rossini (2005) mentions that economically and environmentally, a very viable alternative is to replace the recycling of pure polymers by mixtures of discarded materials. Mechanical recycling causes the breakdown of polymer chains, which impairs the properties of polymers. This degradation is directly proportional to the number of cycles of recycling. Therefore, the blend of two or more discarded polymers can be a realistic alternative, since it can result in materials with very interesting properties, at a low cost. Besides its inexpensiveness, this choice is also a smart solution to the reutilization of garbage. Postconsumption package disposal always occurs in a disorderly manner and without regard for the environment. The recycling process becomes increasingly more important and necessary to remediate environmental impact. According Pang et al. (2000) apud Marconcini & Ruvolo Filho (2006) polyolefins such as high density polyethylene (HDPE), low density polyethylene (LDPE) and polypropylene (PP) and polyesters such as poly (ethylene terephthalate) (PET) are classes of thermoplastics that have been widely used in packaging and constitute a large part of post-consumer waste. The recycling of these materials and their mechanical characterization anticipating the possibility of a new cycle of life in the form of new products is challenging, although technologically and environmentally correct (Marconcini & Ruvolo Filho, 2006). The polymer blends can be obtained basically in two ways (Rossini, 2005):  By dissolving the polymers in a good solvent, common to them, and subsequently letting the solvent evaporate; and  In a mixer where the working temperature is high enough to melt or mollify the polymeric components, without causing degradation of the same. According to Wessler (2007), the polymer blends may be miscible or immiscible. The miscibility is the most important property to be analyzed in a blend, given that all other system properties depend on the number of phases, their morphology and adhesion between them. The miscibility term is directly related to the solubility, i.e., a blend is miscible when the polymers dissolve in each other mutually (Silva, 2011). The immiscible between the various engineering polymers is a limiting factor for its production. Thus, it is necessary to use compatibilization agents for their production. Computational modeling has become increasingly popular. The main objective of models is to assist process optimization with minimal investment of time and resources for experimental work. Most techniques are classified into two main groups: physical models and statistical models as shown by Malinov & Sha (2003). Statistical methods are chosen according to research objectives. There are several multivariate analysis methods for purposes quite different from each other. The desired value and quality of one or more product characteristics can be obtained via experiment analysis and DOE. These methods help determining optimal settings and controllable factors of a process such as: temperature, pressure, amount of reagents, operating time, etc.. When compared to the method of trial and error, DOE also allows a reduction of the number of required tests, and savings in time, labor and money. An important application of DOE is the optimization of experimental formulations as, for example, the composition of mixtures. The formulation development is a fundamental part of the food industry, chemicals, plastics, rubber, paints, medicines, and the like. In materials science, it is important to understand the correlation between material processing, microstructure and properties that enable the optimization of process parameters and compositions of materials to achieve the desired combination of properties, according Malinov & Sha (2003). The problem presented here is to determine the fraction of each polymer blend component, and to determine the agent or, in some cases, an agents system, when it is necessary to use more than one compatibilizing agent. Thus, this text studies the effect of factors, for example, amount of polypropylene, additive type, and amount of additive in the composition of polymer blends, i.e., the optimal polymer blends formulation using factorial design

A lapa do Bugio

A jazida pré-histórica do Bugio constitui uma das mais importantes grutas sepulcrais da faixa estremenha. Encontrava-se intacta à data das primeiras escavações, realizadas em 1957 e 1958. Vicissitudes várias que motivaram a dissolução da primeira equipa e favoreceram diversas depredações, entretanto realizadas, impediram que, antes do recomeço dos trabalhos, em 1966, mesmo dos materiais recuperados, se pudessem extrair todas as informações neles potencialmente contidas. Foi possível, a partir do estudo exaustivo do espólio conservado no Museu de Sesimbra e no recolhido nas escavações de 1966, estabelecer a seguinte sucessão cronológica-cultural: Primeira ocupação - corresponde talvez à ocupação mais importante, integrável no Neolítico recente-final estremenho. Estreitas analogias com o "horizonte dolménico" identificado na vizinha Lapa do Fumo e datado pelo rádio-carbono de 3090 ± 160 a. C. (SERRÃO,1978). A datação realizada no Bugio deu 2800 ± 45 a.C. Segunda ocupação- corresponde muito provavelmente a momento inicial (ou pleno) do Calcolítico, definido pela presença de raros produtos, como o recipiente de osso recolhido na sep. 7 e "ídolos" de calcário, de osso e marfim. Terceira ocupação - Calcolítico final, campaniforme - representada pelos Grupos de Palmela e Inciso. Trata-se da ocupação menos importante, excessivamente valorizada em trabalhos anteriores, talvez pela grande dispersão de fragmentos cerâmicos que não ultrapassam, contudo, nove recipientes (alguns deles representados por apenas um fragmento): taças em calote - (I), de bordo espessado - (I), de tipo Palmela - (I), caçoilas acampanadas - (2), e vasos campaniformes - (2), além de dois recipientes de tipologia mal definida.Le gisement préhistorique de Bugio est l 'une des plus importantes grottes sépulcrales du littoral de l'Estrémadure. Elle a été trouvée intacte lors des premières fouilles, réalisées en 1957 et 1958. Diverses vicissitudes, qui devaient aboutir à la dissolution de la première équipe de fouilleurs et favoriser le pillage du site, empêchèrent la difusion de toute information avant la reprise des travaux en 1966, même sur le matériel récupéré. A partir de l' étude exhaustive du mobilier conservé au Musée de Sesimbra et de celui qui a été découvert en 1966, on a pu établir les niveaux chronologiques suivants: Première occupation, peut-être la plus importante, s'intégrant dans le Néolithique récent et final de l'Estrémadure, présentant d' étroites analogies avec "l'horizon dolménique" identifié sur le site voisin de Lapa do Fumo, daté de 3090 ± 160 a.C. par radio-carbone (SERRÃO, 1978). La datation obtenue à Bugio est de 2800 ± 45 a.C.. Seconde occupation, correspondant très probablement à la phase initiale ou médiane du Chalcolithique, définie par de rares productions, comme le récipient en os recueilli dans la sépulture 7 et les "idoles" en calcaire, en os et en ivoire. Troisième occupation (Chalcolithique final, Campaniforme) représentée par les Groupes de Palmela et incisé. Il s'agit d'une occupation moins importante, surévaluée dans les travaux antérieurs, peut-être en raison de la grande dispersion des fragments de céramiques qui ne correspondaient, cependant, qu'à neuf récipients: coupes en calotte (1 ), coupes au bord épais (1), coupes de type de Palmela (1), casseroles en forme de cloche (2), vases campaniformes (2) et deux récipients à la typologie mal définie

Desequilíbrios genômicos na cardiopatia congênita sindrômica

To identify pathogenic genomic imbalances in patients presenting congenital heart disease (CHD) with extra cardiac anomalies and exclusion of 22q11.2 deletion syndrome (22q11.2 DS). Methods: 78 patients negative for the 22q11.2 deletion, previously screened by fluorescence in situ hybridization (FISH) and/or multiplex ligation probe amplification (MLPA) were tested by chromosomal microarray analysis (CMA). Results: Clinically significant copy number variations (CNVs ≥300. kb) were identified in 10% (8/78) of cases. In addition, potentially relevant CNVs were detected in two cases (993. kb duplication in 15q21.1 and 706. kb duplication in 2p22.3). Genes inside the CNV regions found in this study, such as IRX4, BMPR1A, SORBS2, ID2, ROCK2, E2F6, GATA4, SOX7, SEMAD6D, FBN1, and LTPB1 are known to participate in cardiac development and could be candidate genes for CHD. Conclusion: These data showed that patients presenting CHD with extra cardiac anomalies and exclusion of 22q11.2 DS should be investigated by CMA. The present study emphasizes the possible role of CNVs in CHD. © 2017 Sociedade Brasileira de Pediatria.To identify pathogenic genomic imbalances in patients presenting congenital heart disease (CHD) with extra cardiac anomalies and exclusion of 22q11.2 deletion syndrome (22q11.2 DS). Methods: 78 patients negative for the 22q11.2 deletion, previously screen935497507FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO2008/10596-0, 2008/50421-4, 2009/08756-1, 2011/23794-7149600/2010-0, 471422/2011-8; 471422/2011-8; 2011/23794-7Identificar desequilíbrios genômicos patogênicos em pacientes que apresentam cardiopatias congênitas (CC) e anomalias extracardíacas e exclusão da síndrome de deleção 22q11.2 (SD22q11.2). Foram avaliados por microarray cromossômico (CMA) 78 pacientes neg

Myeloid Sirtuin 2 expression does not impact long-term Mycobacterium tuberculosis control

Sirtuins (Sirts) regulate several cellular mechanisms through deacetylation of several transcription factors and enzymes. Recently, Sirt2 was shown to prevent the development of inflammatory processes and its expression favors acute Listeria monocytogenes infection. The impact of this molecule in the context of chronic infections remains unknown. We found that specific Sirt2 deletion in the myeloid lineage transiently increased Mycobacterium tuberculosis load in the lungs and liver of conditional mice. Sirt2 did not affect long-term infection since no significant differences were observed in the bacterial burden at days 60 and 120 post-infection. The initial increase in M. tuberculosis growth was not due to differences in inflammatory cell infiltrates in the lung, myeloid or CD4+ T cells. The transcription levels of IFN-?, IL-17, TNF, IL-6 and NOS2 were also not affected in the lungs by Sirt2-myeloid specific deletion. Overall, our results demonstrate that Sirt2 expression has a transitory effect in M. tuberculosis infection. Thus, modulation of Sirt2 activity in vivo is not expected to affect chronic infection with M. tuberculosis.Fundação para a Ciência e Tecnologia, Portugal and cofunded by Programa Operacional Regional do Norte (ON.2–O Novo Norte), Quadro de Referência Estratégico Nacional (QREN), through the Fundo Europeu de Desenvolvimento Regional (FEDER). Project grants: PTDC/SAU-MII/101977/2008 (to AGC) and PTDC/BIA-BCM/102776/2008 (to MS). LMT was supported by FCT Grant SFRH/BPD/77399/20

Long-Baseline Neutrino Facility (LBNF) and Deep Underground Neutrino Experiment (DUNE) Conceptual Design Report Volume 2: The Physics Program for DUNE at LBNF

The Physics Program for the Deep Underground Neutrino Experiment (DUNE) at the Fermilab Long-Baseline Neutrino Facility (LBNF) is described