138 research outputs found

    Hybrid Composite Laminates from ESOA-BisGMA Blend and 2-Hydroxyethyl Acrylate (HEA) Treated Jute Fiber

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    The development of an inter-cross-linked polymer network of thermoset-thermoset blends have been extensively studied due to their enhanced mechanical properties. Among various polymer blends, modifications of vinyl ester resin (VER) i.e. styrene cross-linkable Bisphenol-A glycidyldimethacrylate (BisGMA) with epoxidized soybean oil acrylate (ESOA) combinations are an attractive route to promote the performance of the thermoset matrix and to overcome the inferior properties of both the components. The primary goal of this research is to develop hybrid composite laminates from ESOA-BisGMA blend (50:50 wt%) using both untreated and 2-hydroxyethyl acrylate (HEA) treated jute fiber as reinforcement and then to characterize thereof. The mechanical properties like tensile strength, bending strength bending E.modulus, dynamic mechanical analysis, corrosion and ageing studies have been investigated. The results suggested improved properties of the hybrid systems with the incorporation of ESOA-BisGMA blend as the composite matrix. Moreover, HEA treatment of jute fiber enhanced the composite properties further, which interestingly, outperformed the parent ESOA-BisGMA blend and untreated jute-ESOA/BisGMA blend based composite. In this investigation 5 ply of jute fabric has been reinforced into ESOA-BisGMA blend matrix, so that at a low cost thin sheets can be produced. This may be used as an alternate material to wood, which has not been carried out elsewhere

    Planck pre-launch status: Low Frequency Instrument calibration and expected scientific performance

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    We give the calibration and scientific performance parameters of the Planck Low Frequency Instrument (LFI) measured during the ground cryogenic test campaign. These parameters characterise the instrument response and constitute our best pre-launch knowledge of the LFI scientific performance. The LFI shows excellent 1/f1/f stability and rejection of instrumental systematic effects; measured noise performance shows that LFI is the most sensitive instrument of its kind. The set of measured calibration parameters will be updated during flight operations through the end of the mission.Comment: Accepted for publications in Astronomy and Astrophysics. Astronomy & Astrophysics, 2010 (acceptance date: 12 Jan 2010

    The x-ray microcalorimeter spectrometer onboard Athena

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    Trabajo presentado a la conferencia: "Space Telescopes and Instrumentation: Ultraviolet to Gamma Ray" celebrada en Amsterdam (Holanda) el 1 de julio de 2012.-- et al.One of the instruments on the Advanced Telescope for High-Energy Astrophysics (Athena) which was one of the three missions under study as one of the L-class missions of ESA, is the X-ray Microcalorimeter Spectrometer (XMS). This instrument, which will provide high-spectral resolution images, is based on X-ray micro-calorimeters with Transition Edge Sensor (TES) and absorbers that consist of metal and semi-metal layers and a multiplexed SQUID readout. The array (32 x 32 pixels) provides an energy resolution of < 3 eV. Due to the large collection area of the Athena optics, the XMS instrument must be capable of processing high counting rates, while maintaining the spectral resolution and a low deadtime. In addition, an anti-coincidence detector is required to suppress the particle-induced background. Compared to the requirements for the same instrument on IXO, the performance requirements have been relaxed to fit into the much more restricted boundary conditions of Athena. In this paper we illustrate some of the science achievable with the instrument. We describe the results of design studies for the focal plane assembly and the cooling systems. Also, the system and its required spacecraft resources will be given. © (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.Peer Reviewe

    Somatostatin Receptor 1 and 5 Double Knockout Mice Mimic Neurochemical Changes of Huntington's Disease Transgenic Mice

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    Selective degeneration of medium spiny neurons and preservation of medium sized aspiny interneurons in striatum has been implicated in excitotoxicity and pathophysiology of Huntington's disease (HD). However, the molecular mechanism for the selective sparing of medium sized aspiny neurons and vulnerability of projection neurons is still elusive. The pathological characteristic of HD is an extensive reduction of the striatal mass, affecting caudate putamen. Somatostatin (SST) positive neurons are selectively spared in HD and Quinolinic acid/N-methyl-D-aspartic acid induced excitotoxicity, mimic the model of HD. SST plays neuroprotective role in excitotoxicity and the biological effects of SST are mediated by five somatostatin receptor subtypes (SSTR1-5). and R6/2 mice. Conversely, the expression of somatostatin receptor subtypes, enkephalin and phosphatidylinositol 3-kinases were strain specific. SSTR1/5 appears to be important in regulating NMDARs, DARPP-32 and signaling molecules in similar fashion as seen in HD transgenic mice.This is the first comprehensive description of disease related changes upon ablation of G- protein coupled receptor gene. Our results indicate that SST and SSTRs might play an important role in regulation of neurodegeneration and targeting this pathway can provide a novel insight in understanding the pathophysiology of Huntington's disease

    Intentions on desired length of stay among immigrants in Italy

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    Abstract The decision to emigrate from the country of origin may not be a permanent one: migrants can decide to return home or to emigrate to a third country. This phenomenon, established for some time in certain other European countries, has become an important one for Italy only recently. This paper contributes to the knowledge of migrants’ intentions in two ways: on the one hand, it analyses the factors associated with indecision about future plans; on the other, it focuses on the desired length of stay and its relationship with attachments (family, economic, socio-cultural and psychological) to host and home country. We used two logistic regression models: one for migrants’ indecision and the other for migrants’ desired length of stay. The data were collected by survey, coordinated by the ISMU Foundation and conducted in 2008 and 2009 with more than 12,000 migrants living in Italy. According to our results, indecision seems to be associated with an intermediate phase of migration at the early stage of family development in the case of negative balance of the migration experience, while attachment to the host country is associated with longer stay, and no attachments or attachment to the country of origin are associated with shorter stay
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