412 research outputs found

    Mezclas de cera y bentonita para el desarrollo de arcilla industrial de prototipado: resultados preliminares

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    The automotive design process and the materials in the automotive industry in recent years has caused great interest to the industrial and academic sector. In this study was to evaluate the effect of the amount of bentonite on the thermal and rheological properties of the compound bentonite / paraffin wax. Two bentonite ratios were used: paraffin wax (40:60 and 30:70). The paraffin was characterized by Fourier transform infrared spectroscopy (FTIR), the bentonite was characterized by means of x-ray diffraction (XRD), thermogravimetric analysis (TGA), X-ray fluorescence (XRF). The bentonite/paraffine wax composite was characterized by differential-scanning calorimetry (DSC) and rheology. The sample that contains a higher amount of bentonite shows a lower latent heat, and this could cause a greater heat transfer. Finally, the sample that has a lower amount of bentonite evidenced a lower viscosity, and it could be related to a lower interaction between the particles. The sample S1 due to its lower latent heat compared to S2 could represent an interesting alternative to develop prototypingclays. since these materials are characterized by their low working temperatures and easy malleability. Keywords: automotive, prototyping, latent heat, bentonite, paraffin. References [1]X. FerrĂ s-HernĂĄndez, E. Tarrats-Pons, and N. Arimany-Serrat, “Disruption in the automotive industry: A Cambrian moment,” Bus. Horiz., vol. 60, no. 6, pp.855–863, 2017, doi: 10.1016/j.bushor.2017.07.011. [2]O. Heneric, G. Licht, S. Lutz, and W. Urban, “The Europerean Automotive Industry in a Global Context,” Eur. Automot. Ind. Move, pp. 5–44, 2005, doi: 10.1007/3-7908-1644-2_2. [3]S. I.-N. Delhi, “Automotive Revolution & Perspective Towards 2030,” Auto Tech Rev., vol. 5, no. 4, pp. 20–25, Apr. 2016, doi: 10.1365/s40112-016-1117-8.[4]M. Tovey, J. Owen, and P. Street, “in Automotive Design,” vol. 21, pp. 569–588, 2000. [5]Yasusato Yamada, Clay modeling : techniques for giving three-dimensional form to idea. 1997. [6]H. Murray, “Industrial clays case study,” Mining, Miner. Sustain. Dev., vol. 1, no. 64, pp. 1–9, 2002, [Online]. Available: http://www.whitemudresources.com/public/Hayn Murray Clays Case Study.pdf%0Ahttp://whitemudresources.com/public/Hayn Murray ClaysCase Study.pdf. [7]Transparency Market Research, “Industrial Clay Market - Global Industry Analysis, Size, Share, Growth, Trends, and Forecast 2016 - 2024,” New york, 2016.[8]J. Murphy, Additives for Plastics Handbook. Elsevier, 2001. [9]Y. Hong, J. J. Cooper-White, M. E. Mackay, C. J. Hawker, E. Malmström, and N. Rehnberg, “A novel processing aid for polymer extrusion: Rheology and processing of polyethylene and hyperbranched polymer blends,” J. Rheol. (N. Y. N. Y)., vol. 43, no. 3, pp. 781–793, 1999, doi: 10.1122/1.550999. [10]D. P. Rawski, P. Edwards, and U. States, “Pulp and Paper : Non fi brous Components,” no. January, pp.1–4, 2017, doi: 10.1016/B978-0-12-803581-8.10289-9. [11]J. Speight, “Instability and incompatibility of tight oil and shale oil,” Shale Oil Gas Prod. Process., pp. 915–942, 2020, doi: 10.1016/b978-0-12-813315-6.00017-8. [12]T. P. Brown, L. Rushton, M. A. Mugglestone, and D. F. Meechan, “Health effects of a sulphur dioxide air pollution episode,” vol. 25, no. 4, pp. 369–371, 2003,doi: 10.1093/pubmed/fdg083. [13]R. Chihi, I. Blidi, M. Trabelsi-Ayadi, and F. Ayari, “Elaboration and characterization of a low-cost porous ceramic support from natural Tunisian bentonite clay,” Comptes Rendus Chim., vol. 22, no. 2–3, pp. 188–197, 2019, doi: 10.1016/j.crci.2018.12.002. [14]Z. Yi, W. Xiaopeng, and L. I. Dongxu, “Prepartion of organophilic bentonite / paraffin composite phase change energy storage material with melting intercalation method,” pp. 126–131, 2011, doi: 10.4028/www.scientific.net/AMR.284-286.126. [15]I. Krupa and A. S. Luyt, “Thermal and mechanical properties of extruded LLDPE / wax blends,” vol. 73, pp. 157–161, 2001. [16]A. Saleem, L. Frormann, J. Koltermann, and C. Reichelt, “Fabrication and Processing of Polypropylene - Paraffin Compounds with Enhanced Thermal andProcessing Properties : Impact Penetration and Thermal Characterization,” vol. 40164, pp. 1–9, 2014, doi:10.1002/app.40164. [17]M. Mu, P. A. M. Basheer, W. Sha, Y. Bai, and T. Mcnally, “Shape stabilised phase change materials based on a high melt viscosity HDPE and paraffin waxes,”Appl. Energy, vol. 162, pp. 68–82, 2016, doi: 10.1016/j.apenergy.2015.10.030. [18]M. Tovey, “Intuitive and objective processes in automotive design,” Des. Stud., vol. 13, no. 1, pp. 23–41, 1992, doi: 10.1016/0142-694X(92)80003-H. [19]J. Verlinden, A. Kooijman, E. Edelenbos, and C. Go, “Investigation on the use of illuminated clay in automotive styling,” 6th Int. Conf. Comput. Ind. Des.Concept. Des. (CAID&CD), Delft, NETHERLANDS, pp. 514–519, 2005. [20]N. W. Muhamad Bustaman and M. S. Abu Mansor, “A Study on CAD/CAM Application in CNC Milling Using Industrial Clay,” Appl. Mech. Mater., vol. 761, pp. 32–36, 2015, doi: 10.4028/www.scientific.net/AMM.761.32. [21]K. Shimokawa, Japan and the global automotive industry. 2010. [22]A. Bucio, R. Moreno tovar, L. Bucio, J. EspinosadĂĄvila, and F. Anguebes franceschi, “Characterization of beeswax, candelilla wax and paraffin wax for coatingcheeses,” Coatings, vol. 11, no. 3, pp. 1–18, 2021, doi: 10.3390/coatings11030261. [23]F. Valentini, A. Dorigato, A. Pegoretti, M. Tomasi, G. D. SorarĂč, and M. Biesuz, “Si3N4 nanofelts/paraffin composites as novel thermal energy storage architecture,” J. Mater. Sci., vol. 56, no. 2, pp. 1537–1550, 2021, doi: 10.1007/s10853-020-05247-5. [24]F. Paquin, J. Rivnay, A. Salleo, N. Stingelin, and C. Silva, “Multi-phase semicrystalline microstructures drive exciton dissociation in neat plastic semiconductors,” J. Mater. Chem. C, vol. 3, pp. 10715–10722, 2015, doi: 10.1039/b000000x. [25]R. S. Hebbar, A. M. Isloor, B. Prabhu, Inamuddin, A. M. Asiri, and A. F. Ismail, “Removal of metal ions and humic acids through polyetherimide membranewith grafted bentonite clay,” Sci. Rep., vol. 8, no. 1, 2018, doi: 10.1038/s41598-018-22837-1. [26]S. Betancourt-Parra, M. A. DomĂ­nguez-Ortiz, and M. MartĂ­nez-Tejada, “Colombian clays binary mixtures: Physical changes due to thermal treatments,” DYNA, vol. 87, no. 212, pp. 73–79, 2020, doi: 10.15446/dyna.v87n212.82285. [27]A. M. Rabie, E. A. Mohammed, and N. A. Negm, “Feasibility of modified bentonite as acidic heterogeneous catalyst in low temperature catalytic crackingprocess of biofuel production from nonedible vegetable oils,” J. Mol. Liq., vol. 254, no. 2018, pp. 260–266, 2018, doi: 10.1016/j.molliq.2018.01.110. [28]A. Kadeche et al., “Preparation, characterization and application of Fe-pillared bentonite to the removal of Coomassie blue dye from aqueous solutions,” Res. Chem. Intermed., vol. 46, no. 11, pp. 4985–5008, 2020, doi: 10.1007/s11164-020-04236-2. [29]C. I. R. De Oliveira, M. C. G. Rocha, A. L. N. DaSilva, and L. C. Bertolino, “Characterization of bentonite clays from Cubati, ParaĂ­ba Northeast of Brazil,” Ceramica, vol. 62, no. 363, pp. 272–277, 2016, doi:10.1590/0366-69132016623631970. [30]I. Z. Hager, Y. S. Rammah, H. A. Othman, E. M. Ibrahim, S. F. Hassan, and F. H. Sallam, “Nano-structured natural bentonite clay coated by polyvinyl alcohol polymer for gamma rays attenuation,” J. Theor. Appl. Phys., vol. 13, no. 2, pp. 141–153, 2019, doi: 10.1007/ s40094-019-0332-5. [31]A. Tebeje, Z. Worku, T. T. I. Nkambule, and J. Fito, “Adsorption of chemical oxygen demand from textile industrial wastewater through locally prepared bentonite adsorbent,” Int. J. Environ. Sci. Technol., no. 0123456789, 2021, doi: 10.1007/s13762-021-03230-4. [32]F. E. ÖzgĂŒven, A. D. Pekdemir, M. Önal, and Y. Sarıkaya, “Characterization of a bentonite and its permanent aqueous suspension,” J. Turkish Chem. Soc.Sect. A Chem., vol. 7, no. 1, pp. 11–18, 2019, doi: 10.18596/jotcsa.535937. [33]S. Tao, S. Wei, and Y. Yulan, “Characterization of Expanded Graphite Microstructure and Fabrication of Composite Phase-Change Material for Energy Storage,” J. Mater. Civ. Eng., vol. 27, no. 4, p. 04014156, 2015, doi: 10.1061/(asce)mt.1943-5533.0001089. [34]M. Li, Z. Wu, H. Kao, and J. Tan, “Experimental investigation of preparation and thermal performances of paraffin/bentonite composite phase change material,” Energy Convers. Manag., vol. 52, no. 11, pp. 3275–3281, 2011, doi: 10.1016/j.enconman.2011.05.015. [35]S. M. Hosseini, E. Ghasemi, A. Fazlali, and D. E. Henneke, “The effect of nanoparticle concentration on the rheological properties of paraffin-based Co3O4 ferrofluids,” J. Nanoparticle Res., vol. 14, no. 7, 2012, doi: 10.1007/s11051-012-0858-9.El proceso de diseño automotriz y los materiales en la industria automotriz pen los Ășltimos años ha despertado un gran interĂ©s en el sector industrial y acadĂ©mico. En este estudio se evaluĂł el efecto de la cantidad de bentonita sobre las propiedades tĂ©rmicas y reolĂłgicas del compuesto bentonita/ cera de parafina. Se utilizaron dos proporciones de bentonita: cera de parafina (40:60 y 30:70). La parafina se caracterizĂł por espectroscopia infrarroja por transformada de Fourier (FTIR), la bentonita se caracterizĂł mediante difracciĂłn de rayos X (XRD), anĂĄlisis termogravimĂ©trico (TGA), fluorescencia de rayos X (XRF). El compuesto de cera de bentonita / parafina se caracterizĂł por calorimetrĂ­a de barrido diferencial (DSC) y reologĂ­a. La muestra que contiene una mayor cantidad de bentonita presenta un menor calor latente, y esto podrĂ­a provocar una mayor transferencia de calor. Finalmente, la muestra que tiene menor cantidad de bentonita evidenciĂł una menor viscosidad, y podrĂ­a estar relacionado con una menor interacciĂłn entre las partĂ­culas. La muestra S1 debido a su menor calor latente en comparaciĂłn con S2 podrĂ­a representar una alternativa interesante para desarrollar arcillas de prototipado. Ya que estos materiales S3 caracterizan por sus bajas temperaturas de trabajo y fĂĄcil maleabilidad. Palabras clave: automĂłvil, prototipado, reologĂ­a, bentonita, parafina. Referencias [1]X. FerrĂ s-HernĂĄndez, E. Tarrats-Pons, y N. Arimany-Serrat, “Disruption in the automotive industry: A Cambrian moment,” Bus. Horiz., vol. 60, no. 6, pp.855–863, 2017, doi: 10.1016/j.bushor.2017.07.011. [2]O. Heneric, G. Licht, S. Lutz, y W. Urban, “The Europerean Automotive Industry in a Global Context,” Eur. Automot. Ind. Move, pp. 5–44, 2005, doi: 10.1007/3-7908-1644-2_2. [3]S. I.-N. Delhi, “Automotive Revolution & Perspective Towards 2030,” Auto Tech Rev., vol. 5, no. 4, pp. 20–25, Apr. 2016, doi: 10.1365/s40112-016-1117-8. [4]M. Tovey, J. Owen, y P. Street, “in Automotive Design,” vol. 21, pp. 569–588, 2000. [5]Yasusato Yamada, Clay modeling : techniques for giving three-dimensional form to idea. 1997. [6]H. Murray, “Industrial clays case study,” Mining, Miner. Sustain. Dev., vol. 1, no. 64, pp. 1–9, 2002, [En lĂ­nea]. Disponible en: http://www.whitemudresources.com/public/Hayn Murray Clays Case Study.pdf%0Ahttp://whitemudresources.com/public/Hayn Murray ClaysCase Study.pdf. [7]Transparency Market Research, “Industrial Clay Market - Global Industry Analysis, Size, Share, Growth, Trends, and Forecast 2016 - 2024,” New york, 2016.[8]J. Murphy, Additives for Plastics Handbook. Elsevier, 2001. [9]Y. Hong, J. J. Cooper-White, M. E. Mackay, C. J. Hawker, E. Malmström, y N. Rehnberg, “A novel processing aid for polymer extrusion: Rheology and processing of polyethylene and hyperbranched polymer blends,” J. Rheol. (N. Y. N. Y)., vol. 43, no. 3, pp. 781–793, 1999, doi: 10.1122/1.550999. [10]D. P. Rawski, P. Edwards, y U. States, “Pulp and Paper : Non fi brous Components,” no. January, pp.1–4, 2017, doi: 10.1016/B978-0-12-803581-8.10289-9. [11]J. Speight, “Instability and incompatibility of tight oil and shale oil,” Shale Oil Gas Prod. Process., pp. 915–942, 2020, doi: 10.1016/b978-0-12-813315-6.00017-8. [12]T. P. Brown, L. Rushton, M. A. Mugglestone, y D. F. Meechan, “Health effects of a sulphur dioxide air pollution episode,” vol. 25, no. 4, pp. 369–371, 2003,doi: 10.1093/pubmed/fdg083. [13]R. Chihi, I. Blidi, M. Trabelsi-Ayadi, y F. Ayari, “Elaboration and characterization of a low-cost porous ceramic support from natural Tunisian bentonite clay,” Comptes Rendus Chim., vol. 22, no. 2–3, pp. 188–197, 2019, doi: 10.1016/j.crci.2018.12.002. [14]Z. Yi, W. Xiaopeng, y L. I. Dongxu, “Prepartion of organophilic bentonite / paraffin composite phase change energy storage material with melting intercalation method,” pp. 126–131, 2011, doi: 10.4028/www.scientific.net/AMR.284-286.126. [15]I. Krupa y A. S. Luyt, “Thermal and mechanical properties of extruded LLDPE / wax blends,” vol. 73, pp. 157–161, 2001. [16]A. Saleem, L. Frormann, J. Koltermann, y C. Reichelt, “Fabrication and Processing of Polypropylene - Paraffin Compounds with Enhanced Thermal andProcessing Properties : Impact Penetration and Thermal Characterization,” vol. 40164, pp. 1–9, 2014, doi:10.1002/app.40164. [17]M. Mu, P. A. M. Basheer, W. Sha, Y. Bai, y T. Mcnally, “Shape stabilised phase change materials based on a high melt viscosity HDPE and paraffin waxes,”Appl. Energy, vol. 162, pp. 68–82, 2016, doi: 10.1016/j.apenergy.2015.10.030. [18]M. Tovey, “Intuitive and objective processes in automotive design,” Des. Stud., vol. 13, no. 1, pp. 23–41, 1992, doi: 10.1016/0142-694X(92)80003-H. [19]J. Verlinden, A. Kooijman, E. Edelenbos, y C. Go, “Investigation on the use of illuminated clay in automotive styling,” 6th Int. Conf. Comput. Ind. Des.Concept. Des. (CAID&CD), Delft, NETHERLANDS, pp. 514–519, 2005. [20]N. W. Muhamad Bustaman y M. S. Abu Mansor, “A Study on CAD/CAM Application in CNC Milling Using Industrial Clay,” Appl. Mech. Mater., vol. 761, pp. 32–36, 2015, doi: 10.4028/www.scientific.net/AMM.761.32. [21]K. Shimokawa, Japan and the global automotive industry. 2010. [22]A. Bucio, R. Moreno tovar, L. Bucio, J. EspinosadĂĄvila, y F. Anguebes franceschi, “Characterization of beeswax, candelilla wax and paraffin wax for coatingcheeses,” Coatings, vol. 11, no. 3, pp. 1–18, 2021, doi: 10.3390/coatings11030261. [23]F. Valentini, A. Dorigato, A. Pegoretti, M. Tomasi, G. D. SorarĂč, y M. Biesuz, “Si3N4 nanofelts/paraffin composites as novel thermal energy storage architecture,” J. Mater. Sci., vol. 56, no. 2, pp. 1537–1550, 2021, doi: 10.1007/s10853-020-05247-5. [24]F. Paquin, J. Rivnay, A. Salleo, N. Stingelin, y C. Silva, “Multi-phase semicrystalline microstructures drive exciton dissociation in neat plastic semiconductors,” J. Mater. Chem. C, vol. 3, pp. 10715–10722, 2015, doi: 10.1039/b000000x. [25]R. S. Hebbar, A. M. Isloor, B. Prabhu, Inamuddin, A. M. Asiri, y A. F. Ismail, “Removal of metal ions and humic acids through polyetherimide membranewith grafted bentonite clay,” Sci. Rep., vol. 8, no. 1, 2018, doi: 10.1038/s41598-018-22837-1. [26]S. Betancourt-Parra, M. A. DomĂ­nguez-Ortiz, y M. MartĂ­nez-Tejada, “Colombian clays binary mixtures: Physical changes due to thermal treatments,” DYNA, vol. 87, no. 212, pp. 73–79, 2020, doi: 10.15446/dyna.v87n212.82285. [27]A. M. Rabie, E. A. Mohammed, y N. A. Negm, “Feasibility of modified bentonite as acidic heterogeneous catalyst in low temperature catalytic crackingprocess of biofuel production from nonedible vegetable oils,” J. Mol. Liq., vol. 254, no. 2018, pp. 260–266, 2018, doi: 10.1016/j.molliq.2018.01.110. [28]A. Kadeche et al., “Preparation, characterization and application of Fe-pillared bentonite to the removal of Coomassie blue dye from aqueous solutions,” Res. Chem. Intermed., vol. 46, no. 11, pp. 4985–5008, 2020, doi: 10.1007/s11164-020-04236-2. [29]C. I. R. De Oliveira, M. C. G. Rocha, A. L. N. DaSilva, y L. C. Bertolino, “Characterization of bentonite clays from Cubati, ParaĂ­ba Northeast of Brazil,” Ceramica, vol. 62, no. 363, pp. 272–277, 2016, doi:10.1590/0366-69132016623631970. [30]I. Z. Hager, Y. S. Rammah, H. A. Othman, E. M. Ibrahim, S. F. Hassan, y F. H. Sallam, “Nano-structured natural bentonite clay coated by polyvinyl alcohol polymer for gamma rays attenuation,” J. Theor. Appl. Phys., vol. 13, no. 2, pp. 141–153, 2019, doi: 10.1007/ s40094-019-0332-5. [31]A. Tebeje, Z. Worku, T. T. I. Nkambule, y J. Fito, “Adsorption of chemical oxygen demand from textile industrial wastewater through locally prepared bentonite adsorbent,” Int. J. Environ. Sci. Technol., no. 0123456789, 2021, doi: 10.1007/s13762-021-03230-4. [32]F. E. ÖzgĂŒven, A. D. Pekdemir, M. Önal, e Y. Sarıkaya, “Characterization of a bentonite and its permanent aqueous suspension,” J. Turkish Chem. Soc.Sect. A Chem., vol. 7, no. 1, pp. 11–18, 2019, doi: 10.18596/jotcsa.535937. [33]S. Tao, S. Wei, e Y. Yulan, “Characterization of Expanded Graphite Microstructure and Fabrication of Composite Phase-Change Material for Energy Storage,” J. Mater. Civ. Eng., vol. 27, no. 4, p. 04014156, 2015, doi: 10.1061/(asce)mt.1943-5533.0001089. [34]M. Li, Z. Wu, H. Kao, y J. Tan, “Experimental investigation of preparation and thermal performances of paraffin/bentonite composite phase change material,” Energy Convers. Manag., vol. 52, no. 11, pp. 3275–3281, 2011, doi: 10.1016/j.enconman.2011.05.015. [35]S. M. Hosseini, E. Ghasemi, A. Fazlali, y D. E. Henneke, “The effect of nanoparticle concentration on the rheological properties of paraffin-based Co3O4 ferrofluids,” J. Nanoparticle Res., vol. 14, no. 7, 2012, doi: 10.1007/s11051-012-0858-9

    Heterogeneous contributions of change in population distribution of body mass index to change in obesity and underweight NCD Risk Factor Collaboration (NCD-RisC)

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    From 1985 to 2016, the prevalence of underweight decreased, and that of obesity and severe obesity increased, in most regions, with significant variation in the magnitude of these changes across regions. We investigated how much change in mean body mass index (BMI) explains changes in the prevalence of underweight, obesity, and severe obesity in different regions using data from 2896 population-based studies with 187 million participants. Changes in the prevalence of underweight and total obesity, and to a lesser extent severe obesity, are largely driven by shifts in the distribution of BMI, with smaller contributions from changes in the shape of the distribution. In East and Southeast Asia and sub-Saharan Africa, the underweight tail of the BMI distribution was left behind as the distribution shifted. There is a need for policies that address all forms of malnutrition by making healthy foods accessible and affordable, while restricting unhealthy foods through fiscal and regulatory restrictions

    Underlying Event measurements in pp collisions at s=0.9 \sqrt {s} = 0.9 and 7 TeV with the ALICE experiment at the LHC

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    Collaborative design model review in the AEC industry

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    The end result of this research is an application created using freely available tools applied to a case scenarioto perform review meetings by different specialists in real time

    Conceptual design of a Langmuir probe for cold plasma characterization employing statistical design of experiments

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    The characterization and control of plasma-assisted processes, has become increasingly urgent to adapt this kind technology to industrial contexts. This work presents the design and construction of a cold plasma characterization system by electrostatic means (Langmuir probe), based on concepts of plasma physics and tools of engineering, design of experiments and conceptual design. The result of this work is a functional prototype probe and some measurements on the reactor

    Multiplicity dependence of light (anti-)nuclei production in p–Pb collisions at sNN=5.02 TeV

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    The measurement of the deuteron and anti-deuteron production in the rapidity range −1 < y < 0 as a function of transverse momentum and event multiplicity in p–Pb collisions at √sNN = 5.02 TeV is presented. (Anti-)deuterons are identified via their specific energy loss dE/dx and via their time-of- flight. Their production in p–Pb collisions is compared to pp and Pb–Pb collisions and is discussed within the context of thermal and coalescence models. The ratio of integrated yields of deuterons to protons (d/p) shows a significant increase as a function of the charged-particle multiplicity of the event starting from values similar to those observed in pp collisions at low multiplicities and approaching those observed in Pb–Pb collisions at high multiplicities. The mean transverse particle momenta are extracted from the deuteron spectra and the values are similar to those obtained for p and particles. Thus, deuteron spectra do not follow mass ordering. This behaviour is in contrast to the trend observed for non-composite particles in p–Pb collisions. In addition, the production of the rare 3He and 3He nuclei has been studied. The spectrum corresponding to all non-single diffractive p-Pb collisions is obtained in the rapidity window −1 < y < 0 and the pT-integrated yield dN/dy is extracted. It is found that the yields of protons, deuterons, and 3He, normalised by the spin degeneracy factor, follow an exponential decrease with mass number

    ϕ\phi meson production at forward rapidity in Pb-Pb collisions at sNN=2.76\sqrt{s_\mathrm{NN}}=2.76 TeV

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    ϕ\phi meson measurements provide insight into strangeness production, which is one of the key observables for the hot medium formed in high-energy heavy-ion collisions. ALICE measured ϕ\phi production through its decay in muon pairs in Pb–Pb collisions at sNN=2.76\sqrt{s_\mathrm {NN}} = 2.76 TeV in the intermediate transverse momentum range 2<pT<52< p_\mathrm {T}< 5  GeV/c and in the rapidity interval 2.5<y<42.5<y<4 . The ϕ\phi yield was measured as a function of the transverse momentum and collision centrality. The nuclear modification factor was obtained as a function of the average number of participating nucleons. Results were compared with the ones obtained via the kaon decay channel in the same pTp_\mathrm {T} range at midrapidity. The values of the nuclear modification factor in the two rapidity regions are in agreement within uncertainties

    Λc+\Lambda_{\rm c}^+ production in pp collisions at s=7\sqrt{s} = 7 TeV and in p-Pb collisions at sNN=5.02\sqrt{s_{\rm NN}} = 5.02 TeV

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    The pT_{T}-differential production cross section of prompt Λc+_{c}^{+} charmed baryons was measured with the ALICE detector at the Large Hadron Collider (LHC) in pp collisions at s=7 \sqrt{s}=7 TeV and in p-Pb collisions at sNN=5.02 \sqrt{s_{\mathrm{NN}}}=5.02 TeV at midrapidity. The Λc+_{c}^{+} and Λ‟c‟ {\overline{\varLambda}}_{\overline{\mathrm{c}}} were reconstructed in the hadronic decay modes Λc+_{c}^{+} → pK−^{−}π+^{+}, Λc+_{c}^{+} → pKS0_{S}^{0} and in the semileptonic channel Λc+_{c}^{+} → e+^{+}Îœe_{e}Λ (and charge conjugates). The measured values of the Λc+_{c}^{+} /D0^{0} ratio, which is sensitive to the c-quark hadronisation mechanism, and in particular to the production of baryons, are presented and are larger than those measured previously in different colliding systems, centre-of-mass energies, rapidity and pT_{T} intervals, where the Λc+_{c}^{+} production process may differ. The results are compared with the expectations obtained from perturbative Quantum Chromodynamics calculations and Monte Carlo event generators. Neither perturbative QCD calculations nor Monte Carlo models reproduce the data, indicating that the fragmentation of heavy-flavour baryons is not well understood. The first measurement at the LHC of the Λc+_{c}^{+} nuclear modification factor, RpPb_{pPb}, is also presented. The RpPb_{pPb} is found to be consistent with unity and with that of D mesons within the uncertainties, and consistent with a theoretical calculation that includes cold nuclear matter effects and a calculation that includes charm quark interactions with a deconfined medium

    Neutral pion and η\eta meson production at mid-rapidity in Pb-Pb collisions at sNN\sqrt{s_{NN}} = 2.76 TeV

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    International audienceNeutral pion and η meson production in the transverse momentum range 1 <pT< 20 GeV/c have been measured at midrapidity by the ALICE experiment at the Large Hadron Collider (LHC) in central and semicentral Pb-Pb collisions at sNN  = 2.76 TeV. These results were obtained using the photon conversion method as well as the Photon Spectrometer (PHOS) and Electromagnetic Calorimeter detectors. The results extend the upper pT reach of the previous ALICE π0 measurements from 12 to 20 GeV/c and present the first measurement of η meson production in heavy-ion collisions at the LHC. The η/π0 ratio is similar for the two centralities and reaches at high pT a plateau value of 0.457 ± 0.013stat ± 0.018syst. A suppression of similar magnitude for π0 and η meson production is observed in Pb-Pb collisions with respect to their production in pp collisions scaled by the number of binary nucleon-nucleon collisions. We discuss the results in terms of Next to Leading Order (NLO) pQCD predictions and hydrodynamic models. The measurements show a stronger suppression than observed at lower center-of-mass energies in the pT range 6 <pT< 10 GeV/c. For pT< 3 GeV/c, hadronization models describe the π0 results while for the η some tension is observed

    Higher harmonic non-linear flow modes of charged hadrons in Pb-Pb collisions at sNN\sqrt{s_{\rm{NN}}} = 5.02 TeV

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    International audienceAnisotropic flow coefficients, vn_{n}, non-linear flow mode coefficients, χn,mk_{n,mk}, and correlations among different symmetry planes, ρn,mk_{n,mk} are measured in Pb-Pb collisions at sNN \sqrt{s_{\mathrm{NN}}} = 5.02 TeV. Results obtained with multi-particle correlations are reported for the transverse momentum interval 0.2 < pT_{T}< 5.0 GeV/c within the pseudorapidity interval 0.4 < |η| < 0.8 as a function of collision centrality. The vn_{n} coefficients and χn,mk_{n,mk} and ρn,mk_{n,mk} are presented up to the ninth and seventh harmonic order, respectively. Calculations suggest that the correlations measured in different symmetry planes and the non-linear flow mode coefficients are dependent on the shear and bulk viscosity to entropy ratios of the medium created in heavy-ion collisions. The comparison between these measurements and those at lower energies and calculations from hydrodynamic models places strong constraints on the initial conditions and transport properties of the system.[graphic not available: see fulltext
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