2,604 research outputs found

    Diffraction dissociation in proton-proton collisions at s\sqrt{s} = 0.9 TeV, 2.76 TeV and 7 TeV with ALICE at the LHC

    Full text link
    The relative rates of single- and double- diffractive processes were measured with the ALICE detector by studying properties of gaps in the pseudorapidity distribution of particles produced in proton-proton collisions at s\sqrt{s} = 0.9 TeV, 2.76 TeV and 7 TeV. ALICE triggering efficiencies are determined for various classes of events, using a detector simulation validated with data on inclusive particle production. Cross-sections are determined using van der Meer scans to measure beam properties and obtain a measurement of the luminosity

    The critical slip distance for seismic and aseismic fault zones of finite width

    Get PDF
    We present a conceptual model for the effective critical friction distance for fault zones of finite width. A numerical model with 1D elasticity is used to investigate implications of the model for shear traction evolution during dynamic and quasi-static slip. The model includes elastofrictional interaction of multiple, parallel slip surfaces, which obey rate and state friction laws with either Ruina (slip) or Dieterich (time) state evolution. A range of slip acceleration histories is investigated by imposing perturbations in slip velocity at the fault zone boundary and using radiation damping to solve the equations of motion. The model extends concepts developed for friction of bare surfaces, including the critical friction distance L, to fault zones of finite width containing wear and gouge materials. We distinguish between parameters that apply to a single frictional surface, including L and the dynamic slip weakening distance do, and those that represent slip for the entire fault zone, which include the effective critical friction distance, Dcb, and the effective dynamic slip weakening distance Do. A scaling law for Dcb is proposed in terms of L and the fault zone width. Earthquake source parameters depend on net slip across a fault zone and thus scale with Dcb, Do, and the slip at yield strength Da. We find that Da decreases with increasing velocity jump size for friction evolution via the Ruina law, whereas it is independent of slip acceleration rate for the Dieterich law. For both laws, Da scales with fault zone width and shear traction exhibits prolonged hardening before reaching a yield strength. The parameters Dcb and Do increase roughly linearly with fault zone thickness. This chapter and a companion chapter in the volume discuss the problem of reconciling laboratory measurements of the critical friction distance with theoretical and field-based estimates of the effective dynamic slip weakening distance

    Xray Tomographic Microscopic Studies a Resin Embedded Paint Sample from a Mechanical Failing Area in the Floor Tiles of The Art of Painting by Johannes Vermeer (1632-1675)

    Get PDF
    Extended abstract of a paper presented at Microscopy and Microanalysis 2010 in Portland, Oregon, USA, August 1 - August 5, 201

    Endovascular Treatment of a Ruptured Pararenal Abdominal Aortic Aneurysm in a Patient With Coronavirus Disease-2019: Suggestions and Case Report

    Get PDF
    The aim of this report is to discuss emergent repair for complex aortic diseases in patients affected by novel coronavirus pneumonia (coronavirus disease-2019 [COVID-19]), describing a case of ruptured pararenal aortic aneurysm. An eighty-year-old man with COVID-19 was admitted for ruptured aneurysm of the pararenal aorta and hemorrhagic shock. Endovascular repair was chosen, and a proximal extension of the previous abdominal endograft was performed with parallel stents in the right renal artery and the superior mesenteric artery. Endovascular treatment and early anticoagulation are the key for success for vascular emergencies in patients with COVID-19, despite the risk of late endoleak

    Semiquantitative RT-PCR analysis to assess the expression levels of multiple transcripts from the same sample

    Get PDF
    We describe a semiquantitative RT-PCR protocol optimized in our laboratory to extract RNA from as little as 10,000 cells and to measure the expression levels of several target mRNAs from each sample. This procedure was optimized on the human erythroleukemia cell line TF-1 but was successfully used on primary cells and on different cell lines. We describe the detailed procedure for the analysis of Bcl-2 levels. Aldolase A was used as an internal control to normalize for sample to sample variations in total RNA amounts and for reaction efficiency. As for all quantitative techniques, great care must be taken in all optimization steps: the necessary controls to ensure a rough quantitative (semi-quantitative) analysis are described here, together with an example from a study on the effects of TGF-β1 in TF-1 cells

    Three cases of mcr-1-positive colistin-resistant Escherichia coli bloodstream infections in Italy, August 2016 to January 2017

    Get PDF
    We describe three cases of bloodstream infection caused by colistin-resistant Escherichia coli in patients in a tertiary hospital in Italy, between August 2016 and January 2017. Whole genome sequencing detected the mcr-1 gene in three isolated strains belonging to different sequence types (STs). This occurrence of three cases with mcr-1-positive E. coli belonging to different STs in six months suggests a widespread problem in settings where high multidrug resistance is endemic such as in Italy

    Thinning in black pine (Pinus nigra J.F. Arnold) forests: The economic sustainability of the wood-energy supply chain in a case study in Italy

    Get PDF
    In Italy, black pine has been largely used in reforestation projects in the past. Most of these reforestations are characterized by a high instability, vulnerability, and a limited resistance to atmospheric agents. In this situation, it is crucial to define silvicultural interventions able to increase the ecological stability of black pine stands and at the same time to guarantee the economic sustainability of the wood products obtained. Thinning in black pine forests can provide wood material for energy use. The main aim of the present study was to investigate the economic sustainability of a local wood-energy supply chain applying three different forest management options. The case study was Monte Morello forest, a degraded black pine forest located in Central Italy. The results show that the long-term economic sustainability of the wood-energy supply chain is ensured only when the use of bio-fuel is characterized by high energy efficiency. In addition, the results show that public contributions are fundamental to ensure that silvicultural interventions are realized with a positive economic balance and that to surmount this situation many loggings companies are organizing. Finally, the results highlighted the importance of the quantities of thermal energy sold to ensure the economic and environmental efficiency of the wood-energy supply chain
    • …
    corecore