262 research outputs found
Modal pushover analysis of multi-layer overpass bridge
To evaluate the seismic performance of the multi-layer overpass bridge structure easily
and accurately, this paper performed a modal pushover analysis (MPA) on the multi-layer
overpass bridge structure and verified the accuracy of its results. A 3-layer overpass
bridge was used as the research object, and the structural calculation model was
established by the finite element software SPA2000. Modes with a modal mass
participation ratio greater than 1% should be determined first, and the cumulative modal
mass participation ratios greater than 90%. Then a pushover analysis was performed for
each mode to be considered, and structural performance points were obtained by the
capability spectrum method. Seismic response results corresponding to structural
performance points can be obtained by the formula calculation. Finally, response results of
pushover analysis corresponding to each mode were combined by the square root of the
sum of the squares (SRSS) method to obtain the total response result. At the same time,
the nonlinear time history analysis (NL-THA) results of the bridge structure were obtained
by inputting seismic motions into the structural finite element calculation model. The
applicability of MPA on multi-layer overpass bridge structures was evaluated by comparing
response results obtained from MPA and NL-THA. The results show that MPA can reduce
the computational effort compared to NL-THA. The MPA and NL-THA deviations are less
than 20% and 25% in the longitudinal and transverse directions, respectively. The results
of MPA can effectively evaluate the seismic performance of the multi-layer overpass
bridge.Papers presented at the 40th International Southern African Transport Conference on 04 -08 July 202
-mass Modification in - a Signal of Restoration of Chiral Symmetry or Test for Nuclear Matter Models ?
Two recent experiments have demonstrated that the effective -mass in
nuclear medium, as extracted from the reaction, is
substantially reduced. This has been advocated as an indication of partial
restoration of chiral symmetry in nuclear matter. We show that even in the
absence of chiral symmetry, effective mean field nuclear matter models can
explain these findings quantitatively.Comment: ReVTeX file with 2 postscript figures include
Mechanical and Thermal Properties of Polyvinyl Chloride Plasticized with Natural Fatty Acid Esters
From an industrial point of view, the use of new nontoxic and biodegradable plasticizers coming from natural resources is an interesting alternative to traditional plasticizers based on phthalates. In this study, two types of epoxidized fatty acids esters (EFAE) with different molecular weights have been used in order to produce flexible PVC with low toxicity. Different amounts of EFAE 201 and 401 have been considered in this study. Mechanical and thermal properties have been determined and morphology of fracture surface has been studied by scanning electron microscopy.This work was supported by the "Ministerio de Ciencia e Innovacion" [Grant number IPT-310000-2010-37] and the "Universitat Politecnica de Valencia" [Grant number PAID 06-10 Ref: 003-300].Fenollar Gimeno, OÁ.; García Sanoguera, D.; Sánchez Nacher, L.; Boronat Vitoria, T.; López Martínez, J.; Balart Gimeno, RA. (2013). Mechanical and Thermal Properties of Polyvinyl Chloride Plasticized with Natural Fatty Acid Esters. Polymer-Plastics Technology and Engineering. 52(8):761-767. https://doi.org/10.1080/03602559.2013.763352S761767528Zhao, R., Neighbour, G., Deutz, P., & McGuire, M. (2012). Materials selection for cleaner production: An environmental evaluation approach. Materials & Design, 37, 429-434. doi:10.1016/j.matdes.2012.01.014Biedermann-Brem, S., Biedermann, M., Fiselier, K., & Grob, K. (2005). Compositional GC-FID analysis of the additives to PVC, focusing on the gaskets of lids for glass jars. Food Additives and Contaminants, 22(12), 1274-1284. doi:10.1080/02652030500309426Braun, D. (2001). PVC ? origin, growth, and future. Journal of Vinyl and Additive Technology, 7(4), 168-176. doi:10.1002/vnl.10288Summers, J. W. (1997). A review of vinyl technology. Journal of Vinyl and Additive Technology, 3(2), 130-139. doi:10.1002/vnl.10179Islam, R., Islam, T., Nigar, F., Saha, S., Tapash, A., Sharmin, N., … Zaman, H. U. (2011). Fabrication and Mechanical Characterization of Jute Fabrics: Reinforced Polyvinyl Chloride/Polypropylene Hybrid Composites. International Journal of Polymeric Materials, 60(8), 576-590. doi:10.1080/00914037.2010.531822Khan, R. A., Sharmin, N., Khan, M. A., Das, A. K., Dey, K., Saha, S., … Saha, M. (2011). Comparative Studies of Mechanical and Interfacial Properties Between Jute Fiber/PVC and E-Glass Fiber/PVC Composites. Polymer-Plastics Technology and Engineering, 50(2), 153-159. doi:10.1080/03602559.2010.531422Hassan, A., Akbari, A., Hing, N. K., & Ratnam, C. T. (2012). Mechanical and Thermal Properties of ABS/PVC Composites: Effect of Particles Size and Surface Treatment of Ground Calcium Carbonate. Polymer-Plastics Technology and Engineering, 51(5), 473-479. doi:10.1080/03602559.2011.651242Zhu, G., Liu, Y., & Wang, F. (2012). Surface Morphology and Properties of Rigid Poly(γ-benzylL-glutamate) Membrane Modified by Flexible Poly(Vinyl Chloride). International Journal of Polymeric Materials, 61(10), 737-747. doi:10.1080/00914037.2011.610044KAWAMURA, Y., KANNO, S., MUTSUGA, M., & TANAMOTO, K. (2006). Determination of Epoxidized Soybean Oil in Bottled Foods. Journal of the Food Hygienic Society of Japan (Shokuhin Eiseigaku Zasshi), 47(6), 243-248. doi:10.3358/shokueishi.47.243Marcilla, A., Garcia, S., & Garcia-Quesada, J. C. (2008). Migrability of PVC plasticizers. Polymer Testing, 27(2), 221-233. doi:10.1016/j.polymertesting.2007.10.007Wang, Q., & Storm, B. K. (2005). Separation and analysis of low molecular weight plasticizers in poly(vinyl chloride) tubes. Polymer Testing, 24(3), 290-300. doi:10.1016/j.polymertesting.2004.12.002Llop, C., Manrique, A., Navarro, R., Mijangos, C., & Reinecke, H. (2011). Control of the migration behavior of slip agents in polyolefin-based films. Polymer Engineering & Science, 51(9), 1763-1769. doi:10.1002/pen.21963Pedersen, G. A., Jensen, L. K., Fankhauser, A., Biedermann, S., Petersen, J. H., & Fabech, B. (2008). Migration of epoxidized soybean oil (ESBO) and phthalates from twist closures into food and enforcement of the overall migration limit. Food Additives & Contaminants: Part A, 25(4), 503-510. doi:10.1080/02652030701519088Jimenez, A., Lopez, J., Iannoni, A., & Kenny, J. M. (2001). Formulation and mechanical characterization of PVC plastisols based on low-toxicity additives. Journal of Applied Polymer Science, 81(8), 1881-1890. doi:10.1002/app.1621Shea, K. M. (2003). Pediatric Exposure and Potential Toxicity of Phthalate Plasticizers. PEDIATRICS, 111(6), 1467-1474. doi:10.1542/peds.111.6.1467Boudhani, H., Lainé, C., Fulchiron, R., Bounor-Legaré, V., & Cassagnau, P. (2009). Viscoelasticity and mechanical properties of reactive PVC plastisols. Polymer Engineering & Science, 49(6), 1089-1098. doi:10.1002/pen.21356Wang, M. Y., Zhou, N. Q., & Wen, S. P. (2009). The Effect of Concentrations of Modifying Agent and Plasticizer on Cell Morphology of PVC Microcellular Foam. Polymer-Plastics Technology and Engineering, 48(3), 303-309. doi:10.1080/03602550802675678Yang, B., Bai, Y., & Cao, Y. (2010). Effects of inorganic nano-particles on plasticizers migration of flexible PVC. Journal of Applied Polymer Science, 115(4), 2178-2182. doi:10.1002/app.31310Kilinç, S., İyim, T. B., Emik, S., & Özgümüş, S. (2005). Recycling of Waste PET: Usage as Secondary Plasticizer for PVC. Polymer-Plastics Technology and Engineering, 44(8-9), 1379-1388. doi:10.1080/03602550500208228Audic, J.-L., Reyx, D., & Brosse, J.-C. (2003). Migration of additives from food grade polyvinyl chloride (PVC) films: Effect of plasticization by polymeric modifiers instead of conventional plasticizers. Journal of Applied Polymer Science, 89(5), 1291-1299. doi:10.1002/app.12240Fankhauser-Noti, A., Biedermann-Brem, S., & Grob, K. (2006). PVC plasticizers/additives migrating from the gaskets of metal closures into oily food: Swiss market survey June 2005. European Food Research and Technology, 223(4), 447-453. doi:10.1007/s00217-005-0223-7Sharma, V., & Kundu, P. P. (2008). Condensation polymers from natural oils. Progress in Polymer Science, 33(12), 1199-1215. doi:10.1016/j.progpolymsci.2008.07.004Benaniba, M. ., Belhaneche-Bensemra, N., & Gelbard, G. (2001). Stabilizing effect of epoxidized sunflower oil on the thermal degradation of poly(vinyl chloride). Polymer Degradation and Stability, 74(3), 501-505. doi:10.1016/s0141-3910(01)00170-7Atek, D., Belhaneche-Bensemra, N., & Turki, M. (2010). Migration of Epoxidized Sunflower Oil and Dioctyl Phthalate from Rigid and Plasticized Poly(vinyl chloride). International Journal of Polymeric Materials, 59(5), 342-352. doi:10.1080/00914030903478909Ghiou, N., & Benaniba, M. T. (2010). The Effect of Epoxidized Sunflower Oil on the Miscibility of Plasticized PVC/NBR Blends. International Journal of Polymeric Materials, 59(7), 463-474. doi:10.1080/00914031003627007Taghizadeh, M. T., Nalbandi, N., & Bahadori, A. (2008). Stabilizing effect of epoxidized sunflower oil as a secondary stabilizer for Ca/Hg stabilized PVC. Express Polymer Letters, 2(1), 65-76. doi:10.3144/expresspolymlett.2008.9Fenollar, O., Garcia-Sanoguera, D., Sanchez-Nacher, L., Lopez, J., & Balart, R. (2010). Effect of the epoxidized linseed oil concentration as natural plasticizer in vinyl plastisols. Journal of Materials Science, 45(16), 4406-4413. doi:10.1007/s10853-010-4520-6Galià, M., de Espinosa, L. M., Ronda, J. C., Lligadas, G., & Cádiz, V. (2010). Vegetable oil-based thermosetting polymers. European Journal of Lipid Science and Technology, 112(1), 87-96. doi:10.1002/ejlt.200900096Nandanan, V., Joseph, R., & Francis, D. J. (1996). Linseed Oil as a Multipurpose Ingredient in NBR Vulcanizate. Journal of Elastomers & Plastics, 28(4), 326-334. doi:10.1177/009524439602800404Fenollar, O., García, D., Sánchez, L., López, J., & Balart, R. (2009). Optimization of the curing conditions of PVC plastisols based on the use of an epoxidized fatty acid ester plasticizer. European Polymer Journal, 45(9), 2674-2684. doi:10.1016/j.eurpolymj.2009.05.029Fenollar, O., Sanchez-Nacher, L., Garcia-Sanoguera, D., López, J., & Balart, R. (2009). The effect of the curing time and temperature on final properties of flexible PVC with an epoxidized fatty acid ester as natural-based plasticizer. Journal of Materials Science, 44(14), 3702-3711. doi:10.1007/s10853-009-3495-7Crespo, J. E., Balart, R., Sanchez, L., & López, J. (2007). Substitution of di(2-ethylhexyl) phthalate by di(isononyl) cyclohexane-1,2-dicarboxylate as a plasticizer for industrial vinyl plastisol formulations. Journal of Applied Polymer Science, 104(2), 1215-1220. doi:10.1002/app.2576
Chromatin-modifying enzymes as modulators of reprogramming
Generation of induced pluripotent stem cells (iPSCs) by somatic cell reprogramming involves global epigenetic remodelling. Whereas several proteins are known to regulate chromatin marks associated with the distinct epigenetic states of cells before and after reprogramming, the role of specific chromatin-modifying enzymes in reprogramming remains to be determined. To address how chromatin-modifying proteins influence reprogramming, we used short hairpin RNAs (shRNAs) to target genes in DNA and histone methylation pathways, and identified positive and negative modulators of iPSC generation. Whereas inhibition of the core components of the polycomb repressive complex 1 and 2, including the histone 3 lysine 27 methyltransferase EZH2, reduced reprogramming efficiency, suppression of SUV39H1, YY1 and DOT1L enhanced reprogramming. Specifically, inhibition of the H3K79 histone methyltransferase DOT1L by shRNA or a small molecule accelerated reprogramming, significantly increased the yield of iPSC colonies, and substituted for KLF4 and c-Myc (also known as MYC). Inhibition of DOT1L early in the reprogramming process is associated with a marked increase in two alternative factors, NANOG and LIN28, which play essential functional roles in the enhancement of reprogramming. Genome-wide analysis of H3K79me2 distribution revealed that fibroblast-specific genes associated with the epithelial to mesenchymal transition lose H3K79me2 in the initial phases of reprogramming. DOT1L inhibition facilitates the loss of this mark from genes that are fated to be repressed in the pluripotent state. These findings implicate specific chromatin-modifying enzymes as barriers to or facilitators of reprogramming, and demonstrate how modulation of chromatin-modifying enzymes can be exploited to more efficiently generate iPSCs with fewer exogenous transcription factors. © 2012 Macmillan Publishers Limited. All rights reserved
Results from the CUORE-0 experiment
The CUORE-0 experiment searched for neutrinoless double beta decay in 130Te using an array of 52 tellurium dioxide crystals, operated as bolometers at a temperature of 10 mK. It took data in the Gran Sasso National Laboratory (Italy) since March 2013 to March 2015. We present the results of a search for neutrinoless double beta decay in 9.8 kg-years 130Te exposure that allowed us to set the most stringent limit to date on this half-life. The performance of the detector in terms of background and energy resolution is also reported
CUORE and CUORE-0 experiments
Neutrino oscillation experiments proved that neutrinos have mass and this enhanced the interest in neutrinoless double-beta decay (0vßß). The observation of this very rare hypothetical decay would prove the leptonic number violation and would give us indications about neutrinos mass hierarchy and absolute mass scale. CUORE (Cryogenic Underground Observatory for Rare Events) is an array of 988 crystals of TeO2, for a total sensitive mass of 741 kg. Its goal is the observation of 0vßß of 130Te. The crystals, placed into the a dilution cryostat, are operated as bolometers at a temperature close to 10 mK. CUORE commissioning phase has been concluded recently in Gran Sasso National Laboratory, Italy, and data taking is expected to start in spring 2017. If target background rate is reached (0.01counts/day/keV/kg), the sensibility of CUORE will be, in five years of data taking, T1/21026years (1? CL). In order to test the quality of materials and optimize the construction procedures, the collaboration realized CUORE-0, that took data from spring of 2013 to summer 2015. Here, after a brief description of CUORE, I report its commissioning status and CUORE-0 results
Lowering the CUORE energy threshold
The Cryogenic Underground Observatory for Rare Events (CUORE) is a ton-scale double beta decay experiment based on TeO2 cryogenic bolometers and is currently in the last construction stage at the Gran Sasso National Laboratory (LNGS). Its primary goal is to observe neutrino-less double beta decay of 130Te, however thanks to the ultra-low background and large projected exposure it could also be suitable for other rare event searches, as the detection of solar axions, neutrinos from type II supernovae or direct detection of dark matter. The sensitivity for these searches will depend on the performance achieved at the low energy threshold. For this reason a trigger algorithm based on continuous data filtering has been developed which will allow lowering the threshold down to the few keV region. The new trigger has been tested in CUORE-0, a single-tower CUORE prototype consisting of 52 TeO2 bolometers and recently concluded, and here we present the results in terms of trigger efficiency, data selection and low-energy calibration
Status and prospects for CUORE
CUORE is a cryogenic detector consisting of 988 TeO2 crystals, 750 g each, and will be operated at a temperature of ~10 mK, to search for neutrinoless double beta decay (0¿ßß) of 130Te. The detector, in the final stages of construction at the Laboratori Nazionali del Gran Sasso (Italy), will start its operations in 2016. CUORE-0, its pilot experiment, has proven the feasibility of CUORE, demonstrating that the target background of 0.01 counts/keV/kg/y and the energy resolution of 5 keV are within reach. CUORE-0 also made the most precise measurement of the 2¿ßß decay. The expected sensitivity of CUORE to the 0¿ßß 130Te half-life is 9 •1025y, for 5 years of data taking. Here, we report the most recent results of CUORE-0, their implications for CUORE, and the current status of the CUORE experiment
Genome-wide survival study identifies a novel synaptic locus and polygenic score for cognitive progression in Parkinson's disease
A key driver of patients' well-being and clinical trials for Parkinson's disease (PD) is the course that the disease takes over time (progression and prognosis). To assess how genetic variation influences the progression of PD over time to dementia, a major determinant for quality of life, we performed a longitudinal genome-wide survival study of 11.2 million variants in 3,821 patients with PD over 31,053 visits. We discover RIMS2 as a progression locus and confirm this in a replicate population (hazard ratio (HR) = 4.77, P = 2.78 x 10(-11)), identify suggestive evidence for TMEM108 (HR = 2.86, P = 2.09 x 10(-8)) and WWOX (HR = 2.12, P = 2.37 x 10(-8)) as progression loci, and confirm associations for GBA (HR = 1.93, P = 0.0002) and APOE (HR = 1.48, P = 0.001). Polygenic progression scores exhibit a substantial aggregate association with dementia risk, while polygenic susceptibility scores are not predictive. This study identifies a novel synaptic locus and polygenic score for cognitive disease progression in PD and proposes diverging genetic architectures of progression and susceptibility.A genome-wide survival study identifies variants at RIMS2 associated with progression of Parkinson's disease to dementia and highlights divergence in the genetic architecture of disease onset and progression.Neurological Motor Disorder
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