3,545 research outputs found

    LONG-TERM TEMPERATURE MONITORING OF VOLCANIC AREAS BY DISTRIBUTED OPTICAL FIBER SENSORS

    Get PDF
    We present the first results of long- term monitoring of temperature profiles at the Campi Flegrei caldera. The measurements were carried out along a 76 meters-deep borehole already equipped with a borehole strain-meter. We installed a cable containing a loop of optical fiber in order to use a fiber-optics distributed sensor based on stimulated Brillouin scattering. The obtained data are consistent with results of both deep and surface geothermal explorations and indicate that geothermal gradient can be efficiently measured and monitored by the proposed technique

    About the shallow resistivity structure of Vesuvius volcano

    Get PDF
    Magnetotelluric (MT) soundings performed in the past in the volcanic area of Mt. Vesuvius by two independent research groups showed in the same places MT apparent resistivity curves with very similar shape, but statically shifted by one order of magnitude, at least. To try to resolve this ambiguity new controlled source audio-magnetotelluric (CSAMT) measurements have been carried out in the same MT sites. The interpretation of the CSAMT dataset, combined with that of two shallow dipole-dipole geoelectrical resistivity tomographies previously carried out in the area have allowed a reliable electrical structure to be recovered down to a few km of depth, which will next be used for a best constrained re-interpretation of the deep MT soundings

    Clues on the origin of post-2000 earthquakes at Campi Flegrei caldera (Italy)

    Get PDF
    Acknowledgements We thank the INGV-OV staff involved in the management and maintenance of the seismic and GPS networks and Francesca Di Luccio for the data of the best located earthquakes. We acknowledge Valerio Acocella and an anonymous reviewer for the helpful comments that improved the clarity of the manuscript.This study has benefited from funding provided by INGV (project COHESO) by the Italian Presidenza del Consiglio dei Ministri Dipartimento della Protezione Civile (DPC), INGV-DPC Research Agreement 2012–2014, Progetto V2 “Precursori di eruzioni”. This paper does not necessarily represent DPC official opinion and policies. EdP has been partly supported by Spanish Project Ephestos, CGL2011-29499-C02-01 and KNOWAVES, TEC2015-68752. We wish to acknowledge the former contribution of Lorenzo Casertano, Oliveri del Castillo and Maria Teresa Quagliariello, who, in an early paper published on Nature in 1976, first discussed the importance of fluids in the dynamics of Campi Flegrei Caldera.Peer reviewedPublisher PD

    Hydrothermal pressure-temperature control on CO2 emissions and seismicity at Campi Flegrei (Italy)

    Get PDF
    Fluids supplied by stored magma at depth are causal factors of volcanic unrest, as they can cause pressurization/heating of hydrothermal systems. However, evidence for links between hydrothermal pressurization, CO2 emission and volcano seismicity have remained elusive. Here, we use recent (2010−2020) observations at Campi Flegrei caldera (CFc) to show hydrothermal pressure, gas emission and seismicity at CFc share common source areas and well-matching temporal evolutions. We interpret the recent escalation in seismicity and surface gas emissions as caused by pressure-temperature increase at the top of a vertically elongated (0.3–2 km deep) gas front. Using mass (steam) balance considerations, we show hydrothermal pressurization is causing energy transfer from the fluids to the host rocks, ultimately triggering low magnitude earthquakes within a seismogenetic volume containing the hydrothermal system. This mechanism is probably common to other worldwide calderas in similar hydrothermal activity state

    Comparative LCA of concrete with recycled aggregates: a circular economy mindset in Europe

    Full text link
    [EN] Purpose Construction and demolition waste (C&DW) is the largest waste stream in the European Union (EU) and all over the world. Proper management of C&DW and recycled materials¿including the correct handling of hazardous waste¿can have major benefits in terms of sustainability and the quality of life. The Waste Framework Directive 2008/98/EC aims to have 70% of C&DW recycled by 2020. However, except for a few EU countries, only about 50% of C&DW is currently being recycled. In the present research, the environmental impact of concrete with recycled aggregates and with geopolymer mixtures is analysed. The aim of the present research is to propose a comparative LCA of concrete with recycled aggregates in the context of European politics. Methods Life cycle assessment (LCA) methodology is applied using Simapro© software. A cradle to grave analysis is carried out. The results are analysed based on the database Ecoinvent 3.3 and Impact 2002+. Results Results show that the concrete with 25% recycled aggregates is the best solution from an environmental point of view. Furthermore, geopolymer mixtures could be a valid alternative to reduce the phenomenon of ¿global warming¿; however, the production of sodium silicate and sodium hydroxide has a great environmental impact. Conclusions A possible future implementation of the present study is certainly to carry out an overall assessment and to determine the most cost-effective option among the different competing alternatives through the life cycle cost analysis.Colangelo, F.; Gómez-Navarro, T.; Farina, I.; Petrillo, A. (2020). Comparative LCA of concrete with recycled aggregates: a circular economy mindset in Europe. International Journal of Life Cycle Assessment. 25(9):1790-1804. https://doi.org/10.1007/s11367-020-01798-6S17901804259Akhtar A, Sarmah (2018) Construction and demolition waste generation and properties of recycled aggregate concrete: a global perspective. J Cleaner Prod 186:262–281Bare JC, Hofstetter P, Penningtonne DW, Helias A, de Haes U (2000) Midpoints versus endpoints: the sacrifices and benefits. Int J Life Cycle Assess 5(6):319–326Blengini GA, Garbarino E (2010) Resources and waste management in Turin (Italy): the role of recycled aggregates in the sustainable supply mix. J Clean Prod 18(10–11):1021–1030Blengini GA, Garbarino E, Šolar S, Shields DJ, Hámor T, Vinai R, Agioutantis Z (2012) Life cycle assessment guidelines for the sustainable production and recycling of aggregates: the sustainable aggregates resource management project (SARMa). J Clean Prod 27:177–181Blengini GA, Garbarino E, Bevilacqua P (2017) Sustainability and integration between mineral resources and C&DW management: overview of key issues towards a resource-efficient Europe. Env Eng Man J 16(2):493–502Borghi G, Pantini S, Rigamonti L (2018) Life cycle assessment of non-hazardous construction and demolition waste (CDW) management in Lombardy region (Italy). J Clean Prod 184:815–825Braga AM, Silvestre JD, de Brito J (2017) Compared environmental and economic impact from cradle to gate of concrete with natural and recycled coarse aggregates. J Clean Prod 162:529–543Chen C, Habert G, Bouzidi Y, Jullien A, Ventura A (2010) LCA allocation procedure used as an incitative method for waste recycling: an application to mineral additions in concrete. Res Con Rec 54(12):1231–1240Chen Z, Gu H, Bergman RD, Liang S (2020) Comparative life-cycle assessment of a high-rise mass timber building with an equivalent reinforced concrete alternative using the Athena impact estimator for buildings. Sustainability (Switzerland) 12(11):4708Colangelo F, Cioffi R (2017) Mechanical properties and durability of mortar containing fine fraction of demolition wastes produced by selective demolition in South Italy. Comp Part B: Eng 115:43–50Colangelo F, Petrillo A, Cioffi R, Borrelli C, Forcina A (2018a) Life cycle assessment of recycled concretes: a case study in southern Italy. Sci Total Env 615:1506–1517Colangelo F, Forcina A, Farina I, Petrillo A (2018b) Life cycle assessment (LCA) of different kinds of concrete containing waste for sustainable construction. Buildings 8(5):70Colangelo F, Navarro TG, Petrillo A, Farina I, Cioffi R (2020) Life-cycle impact of concrete with recycled materials. Encyclopedia of Renewable and Sustainable Materials, Volume 5(2020):414–421COM (2012) 433, COMMUNICATION FROM THE COMMISSION TO THE EUROPEAN PARLIAMENT AND THE COUNCIL Strategy for the sustainable competitiveness of the construction sector and its enterprises, http://eur-lex.europa.eu/procedure/EN/201859, Brussels, 31.7.2012, COM(2012) 433 finalCOM (2014) 445, COMMUNICATION FROM THE COMMISSION TO THE EUROPEAN PARLIAMENT AND THE COUNCIL, http://ec.europa.eu/environment/eussd/pdf/SustainableBuildingsCommunication.pdf, Brussels, 1.7.2014 COM(2014) 445 finalDavidovits J (2018) Geopolymers based on natural and synthetic metakaolin a critical review. Ceramic Eng Science Proc 38(3):201–214Di Maria A, Eyckmans J, Van Acker K (2018) Downcycling versus recycling of construction and demolition waste: combining LCA and LCC to support sustainable policy making. Waste Man 75:3–21Directive 2008/98/EC on waste (Waste Framework Directive), http://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:32008L0098EN 1992-1-1:(2004) Eurocode 2: Design of concrete structures - Part 1–1: General rules and rules for buildingsEstanqueiro B, Dinis Silvestre J, de Brito J, Duarte Pinheiro M (2018) Environmental life cycle assessment of coarse natural and recycled aggregates for concrete. Eur J Env Civ Eng 22(4):429–449Etxeberria M, Vázquez E, Marí A, Barra M (2007) Influence of amount of recycled coarse aggregates and production process on properties of recycled aggregate concrete. Cem Conc Res 37(5):735–742EU construction & demolition waste management protocol (2016) BrusselsGálvez-Martos J-L, Styles D, Schoenberger H, Zeschmar-Lahl B (2018) Construction and demolition waste best management practice in Europe. Res Con Rec 136:166–178Gluth, G.J.G., Arbi, K., Bernal, S.A., Bondar, D., Castel, A., Chithiraputhiran, S., Dehghan, A., Dombrowski-Daube, K., Dubey, A., Ducman, V., Peterson, K., Pipilikaki, P., Valcke, S.L.A., Ye, G., Hajimohammadi, A., van Deventer, J.S.J., 2017. Characterisation of one-part geopolymer binders made from fly ash. Waste Biom Val, 8(1), pp. 225–233Gomes R, Silvestre JD, de Brito J (2020) Environmental, economic and energy life cycle assessment “from cradle to cradle” (3E-C2C) of flat roofs. Journal of Building Engineering 32:101436ISO 14040 (2006) Environmental management life cycle assessment. Principles and Framework. ISO, GenevaISO 14044 (2006) Environmental management. Life cycle assessment. Requirements and Guidelines. ISO, GenevaJafary Nasab T, Monavari SM, Jozi SA, Majedi H (2020) Assessment of carbon footprint in the construction phase of high-rise constructions in Tehran. Int J Environ Sci Technol 17(6):3153–3164Jolliet O, Margni M, Charles R, Humbert S, Payet J, Rebitzer G, Rosenbaum R (2003) Impact 2002+: a new life cycle impact assessment methodology. Int J Life Cycle Assess 8(6):324–333Khan MW, Ali Y, De Felice F, Salman A, Petrillo A (2019) Impact of brick kilns industry on environment and human health in Pakistan. Sci Total Environ 678:383–389Knoeri C, Sanyé-Mengual E, Althaus H-J (2013) Comparative LCA of recycled and conventional concrete for structural applications. Int J Life Cycle Assess 18(5):909–918Lu W, Yan H (2011) A framework for understanding waste management studies in construction. Waste Man 31:1252–1260Marinković S, Radonjanin V, Malešev M, Ignjatović I (2010) Comparative environmental assessment of natural and recycled aggregate concrete. Waste Man 30(11):2255–2264Mercante IT, Bovea MD, Ibáñez-Forés V, Arena AP (2012) Life cycle assessment of construction and demolition waste management systems: a Spanish case study. Int J Life Cycle Assess 17(2):232–241Pantini S, Giurato M, Rigamonti L (2019) A LCA study to investigate resource-efficient strategies for managing post-consumer gypsum waste in Lombardy region (Italy). Res Con Rec 147:157–168Petrillo A, Cioffi R, De Felice F, Colangelo F, Borrelli C (2016) An environmental evaluation: a comparison between geopolymer and OPC concrete paving blocks manufacturing process in Italy. Env Prog Sus Energy 35(6):1699–1708Provis JL (2017) Alkali-activated cementitious materials and concretes - steps towards standardization, American Concrete Inst, ACI Special Publication 2017-January (SP 320), pp. 444-448Sayagh S, Ventura A, Hoang T, François D (2010) Sensitivity of the LCA allocation procedure for BFS recycled into pavement structures. Res cons rec 54(6):348–358Tangtinthai N, Heidrich O, Manning DAC (2019) Role of policy in managing mined resources for construction in Europe and emerging economies. J Env Man 236:613–621Tošić N, Marinković S, Dašić T, Stanić M (2015) Multicriteria optimization of natural and recycled aggregate concrete for structural use. J Clean Prod 87(1):766–776Van den Heede P, De Belie N (2012) Environmental impact and life cycle assessment (LCA) of traditional and ‘green’ concretes: literature review and theoretical calculations. Cem Conc Comp 34(4):431–442Vossberg C, Mason-Jones K, Cohen B (2014) An energetic life cycle assessment of C&D waste and container glass recycling in Cape Town, South Africa. Res Con Rec 88:39–49Walling SA, Notman S, Watts P, Govan N, Provis JL (2019) Portland cement based immobilization/destruction of chemical weapon agent degradation products. Industrial Eng Chemistry Res 58(24):10383–10393Wu H, Zuo J, Yuan H, Zillante G, Wang J (2019) A review of performance assessment methods for construction and demolition waste management. Res Cons Recycling 150:104407Zhang C, Hu M, Dong L, Gebremariam A, Mirand-Xicotencatl B, Di Maio F, Tukker A (2019) Eco-efficiency assessment of technological innovations in high-grade concrete recycling. Res Cons Recycling 149:649–66

    Critical Review of Theoretical Models for Anomalous Effects (Cold Fusion) in Deuterated Metals

    Full text link
    We briefly summarize the reported anomalous effects in deuterated metals at ambient temperature, commonly known as "Cold Fusion" (CF), with an emphasis on important experiments as well as the theoretical basis for the opposition to interpreting them as cold fusion. Then we critically examine more than 25 theoretical models for CF, including unusual nuclear and exotic chemical hypotheses. We conclude that they do not explain the data.Comment: 51 pages, 4 Figure

    Precise measurement of the top quark mass in the dilepton channel at D0

    Get PDF
    We measure the top quark mass (mt) in ppbar collisions at a center of mass energy of 1.96 TeV using dilepton ttbar->W+bW-bbar->l+nubl-nubarbbar events, where l denotes an electron, a muon, or a tau that decays leptonically. The data correspond to an integrated luminosity of 5.4 fb-1 collected with the D0 detector at the Fermilab Tevatron Collider. We obtain mt = 174.0 +- 1.8(stat) +- 2.4(syst) GeV, which is in agreement with the current world average mt = 173.3 +- 1.1 GeV. This is currently the most precise measurement of mt in the dilepton channel.Comment: 7 pages, 4 figure

    Direct measurement of the mass difference between top and antitop quarks

    Get PDF
    We present a direct measurement of the mass difference between top and antitop quarks (dm) in lepton+jets top-antitop final states using the "matrix element" method. The purity of the lepton+jets sample is enhanced for top-antitop events by identifying at least one of the jet as originating from a b quark. The analyzed data correspond to 3.6 fb-1 of proton-antiproton collisions at 1.96 TeV acquired by D0 in Run II of the Fermilab Tevatron Collider. The combination of the e+jets and mu+jets channels yields dm = 0.8 +/- 1.8 (stat) +/- 0.5 (syst) GeV, which is in agreement with the standard model expectation of no mass difference.Comment: submitted to Phys. Rev.

    Search for first generation leptoquark pair production in the electron + missing energy + jets final state

    Get PDF
    We present a search for the pair production of first generation scalar leptoquarks (LQ) in data corresponding to an integrated luminosity of 5.4 fb1^{-1} collected with the D0 detector at the Fermilab Tevatron Collider in ppbar collisions at s=1.96\sqrt{s}=1.96 TeV. In the channel LQLQˉeνeqqLQ \bar{LQ} \rightarrow e\nu_e qq', where q, q' are u or d quarks, no significant excess of data over background is observed, and we set a 95% C.L. lower limit of 326 GeV on the leptoquark mass, assuming equal probabilities of leptoquark decays to eq and νeq\nu_e q'.Comment: 7 pages, 6 figures, submitted to PRD-R

    Search for the standard model and a fermiophobic Higgs boson in diphoton final states

    Get PDF
    We present a search for the standard model Higgs boson and a fermiophobic Higgs boson in the diphoton final states based on 8.2 fb-1 of ppbar collisions collected with the D0 detector at the Fermilab Tevatron Collider. No excess of data above background predictions is observed and upper limits at the 95% C.L. on the cross section multiplied by the branching fraction are set which are the most restrictive to date. A fermiophobic Higgs boson with a mass below 112.9 GeV is excluded at the 95% C.L.Comment: 12 pages, 21 figures, submitted to PR
    corecore