17 research outputs found

    Indexation of dynamic and static geomechanical properties of a cemented aggregate for transportation engineering

    Get PDF
    This paper presents an extensive experimental program aiming to the mechanical characterisation of an aggregate stabilised with cement. This geomaterial is the product of a quarry of limestone located in north region of Portugal. The aggregate is often used in current subgrading of infrastructures for transportation, namely in railway lines. Complementary, aggregate-cement admixtures are used for transition zones, such as in between deformable embankments on soft grounds lining on rigid structures, such as bridgesfounded on deep foundations, such as piles or similar. The demand for smooth transition between diverse stiffness zones implies an optimization of the composition of the enriched materials that will be used for such purpose, such as aggregate-cement admixtures. The optimization requires a thorough mechanical characterisation including dynamic tests, with recourse to geophysical techniques, cyclic and monotonic triaxial tests and, ideally,indexed to simple uniaxial compression and indirect tensile tests. The results that will be presented herein have allowed a good mechanical characterisation of the referred aggregate, in terms of the estimation of combinations of the cement content and the admixture compaction level, resulting in new correlations for design purposes

    Bulky DNA adducts, 4-aminobiphenyl-haemoglobin adducts and diet in the European Prospective Investigation into Cancer and Nutrition (EPIC) prospective study

    Get PDF
    In contrast to some extensively examined food mutagens, for example, aflatoxins, N-nitrosamines and heterocyclic amines, some other food contaminants, in particular polycyclic aromatic hydrocarbons (PAH) and other aromatic compounds, have received less attention. Therefore, exploring the relationships between dietary habits and the levels of biomarkers related to exposure to aromatic compounds is highly relevant. We have investigated in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort the association between dietary items (food groups and nutrients) and aromatic DNA adducts and 4-aminobiphenyl-Hb adducts. Both types of adducts are biomarkers of carcinogen exposure and possibly of cancer risk, and were measured, respectively, in leucocytes and erythrocytes of 1086 (DNA adducts) and 190 (Hb adducts) non-smokers. An inverse. statistically significant, association has been found between DNA adduct levels and dietary fibre intake (P=0.02), vitamin E (P =0.04) and alcohol (P=0.03) but not with other nutrients or food groups. Also, an inverse association between fibre and fruit intake, and BMI and 4-aminobiphenyl-Hb adducts (P=0.03, 0.04, and 0.03 respectively) was observed. After multivariate regression analysis these inverse correlations remained statistically significant, except for the correlation adducts v. fruit intake. The present study suggests that fibre intake in the usual range can modify the level of DNA or Hb aromatic adducts, but Such role seems to be quantitatively modest. Fibres could reduce the formation of DNA adducts in different manners, by diluting potential food mutagens and carcinogens in the gastrointestinal tract, by speeding their transit through the colon and by binding carcinogenic substances

    Gamma-Ray Burst observations by the high-energy charged particle detector on board the CSES-01 satellite between 2019 and 2021

    Full text link
    In this paper we report the detection of five strong Gamma-Ray Bursts (GRBs) by the High-Energy Particle Detector (HEPD-01) mounted on board the China Seismo-Electromagnetic Satellite (CSES-01), operational since 2018 on a Sun-synchronous polar orbit at a \sim 507 km altitude and 97^\circ inclination. HEPD-01 was designed to detect high-energy electrons in the energy range 3 - 100 MeV, protons in the range 30 - 300 MeV, and light nuclei in the range 30 - 300 MeV/n. Nonetheless, Monte Carlo simulations have shown HEPD-01 is sensitive to gamma-ray photons in the energy range 300 keV - 50 MeV, even if with a moderate effective area above \sim 5 MeV. A dedicated time correlation analysis between GRBs reported in literature and signals from a set of HEPD-01 trigger configuration masks has confirmed the anticipated detector sensitivity to high-energy photons. A comparison between the simultaneous time profiles of HEPD-01 electron fluxes and photons from GRB190114C, GRB190305A, GRB190928A, GRB200826B and GRB211211A has shown a remarkable similarity, in spite of the different energy ranges. The high-energy response, with peak sensitivity at about 2 MeV, and moderate effective area of the detector in the actual flight configuration explain why these five GRBs, characterised by a fluence above \sim 3 ×\times 105^{-5} erg cm2^{-2} in the energy interval 300 keV - 50 MeV, have been detected.Comment: Accepted for publication in The Astrophysical Journal (ApJ

    Retaining structures made of discontinuous piles

    No full text
    The development of the real-estate business in Romania lead inevitably to the development of high rise buildings with several basement storeys for parking spaces. This graduation project shows the methods to perform the computation leading to the proper design of the self-supported retaining walls. This kind of walls are the best from the point of view of the ease in working within the excavation space, but are the most dangerous since no propping is provided if some unfavourable events appear. The case history shows the case of an excavation of maximum 11m depth in Fabrica de Glucoza street, Bucharest

    In vivo targeting and growth inhibition of the A20 murine B-cell lymphoma by an idiotype-specific peptide binder

    No full text
    B-cell lymphoma is a clonal expansion of neoplastic cells that may result in fatal outcomes. Here, we report the in vivo targeting and growth inhibition of aggressive A20 murine B-cell lymphoma by idiotype-specific peptide pA20-36. pA20-36 was selected from random peptide libraries and bound specifically to the B-cell receptor (BCR) of A20 cells in mice engrafted with A20 lymphoma, as shown by histology and positron emission tomographic analysis. BCR cross-linking of A20 cells with pA20-36 resulted in massive apoptosis of targeted tumor cells and in an increased survival of the diseased animals without any detectable evidence of toxicity. The pA20-36 treatment reverted the immune suppression of the tumor microenvironment as shown by reduced expression of vascular endothelial growth factor, interleukin-10, and transforming growth factor-β cytokines together with a lower number of CD11b+Gr-1+ inhibitor myeloid-derived suppressor cells and Foxp3+CD4+ Treg cells. Furthermore, pA20-36 treatment was associated with an increased number of tumor-infiltrating, activated CD8+ T cells that exerted a tumor-specific cytolytic activity. These findings show that a short peptide that binds specifically to the complementarity-determining regions of the A20 BCR allows in vivo detection of neoplastic cells together with significant inhibition of tumor growth in vivo. © 2010 by The American Society of Hematology
    corecore