3,314 research outputs found

    Cubipod® Armor Design in Depth-Limited Regular Wave-Breaking Conditions

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    [EN] Armor stability formulas for mound breakwaters are commonly based on 2D small-scale physical tests conducted in non-overtopping and non-breaking conditions. However, most of the breakwaters built around the world are located in breaking or partially-breaking wave conditions, where they must withstand design storms having some percentage of large waves breaking before they reach the structure. In these cases, the design formulas for non-breaking wave conditions are not fully valid. This paper describes the specific 2D physical model tests carried out to analyze the trunk hydraulic stability of single- and double-layer Cubipod (R) armors in depth-limited regular wave breaking and non-overtopping conditions with horizontal foreshore (m = 0) and armor slope (alpha) with cot alpha = 1.5. An experimental methodology was established to ensure that 100 waves attacked the armor layer with the most damaging combination of wave height (H) and wave period (T) for the given water depth (h(s)). Finally, for a given water depth, empirical formulas were obtained to estimate the Cubipod (R) size which made the armor stable regardless of the deep-water wave storm.This research was funded by Conselleria d'Educacio, Investigacio, Cultura i Esport (Generalitat Valenciana) under grant GV/2017/031.Gómez-Martín, ME.; Herrera, MP.; Gonzalez-Escriva, J.; Medina, JR. (2018). Cubipod® Armor Design in Depth-Limited Regular Wave-Breaking Conditions. Journal of Marine Science and Engineering. 6(4):150-161. https://doi.org/10.3390/jmse6040150S15016164Herrera, M. P., Gómez-Martín, M. E., & Medina, J. R. (2017). Hydraulic stability of rock armors in breaking wave conditions. Coastal Engineering, 127, 55-67. doi:10.1016/j.coastaleng.2017.06.010Battjes, J. A., & Groenendijk, H. W. (2000). Wave height distributions on shallow foreshores. Coastal Engineering, 40(3), 161-182. doi:10.1016/s0378-3839(00)00007-7Medina, J. R., & Gómez-Martín, M. E. (2012). KD AND SAFETY FACTORS OF CONCRETE ARMOR UNITS. Coastal Engineering Proceedings, 1(33), 29. doi:10.9753/icce.v33.structures.29Melby, J. A., & Kobayashi, N. (1998). Progression and Variability of Damage on Rubble Mound Breakwaters. Journal of Waterway, Port, Coastal, and Ocean Engineering, 124(6), 286-294. doi:10.1061/(asce)0733-950x(1998)124:6(286)Van Gent, M. R. A. (2013). Rock stability of rubble mound breakwaters with a berm. Coastal Engineering, 78, 35-45. doi:10.1016/j.coastaleng.2013.03.003Celli, D., Pasquali, D., De Girolamo, P., & Di Risio, M. (2018). Effects of submerged berms on the stability of conventional rubble mound breakwaters. Coastal Engineering, 136, 16-25. doi:10.1016/j.coastaleng.2018.01.011Concrete Layer Innovation (CLI) http://www.concretelayer.com/documentationGuidelines for Xbloc Concept Designs https://www.xbloc.com/sites/default/files/domain-671/documents/xbloc-design-guidelines-2014-671-15039173271578936988.pdfGómez-Martín, M. E., & Medina, J. R. (2014). Heterogeneous Packing and Hydraulic Stability of Cube and Cubipod Armor Units. Journal of Waterway, Port, Coastal, and Ocean Engineering, 140(1), 100-108. doi:10.1061/(asce)ww.1943-5460.0000223Medina, J. R., Hudspeth, R. T., & Fassardi, C. (1994). Breakwater Armor Damage due to Wave Groups. Journal of Waterway, Port, Coastal, and Ocean Engineering, 120(2), 179-198. doi:10.1061/(asce)0733-950x(1994)120:2(179)Herrera, M. P., & Medina, J. R. (2015). Toe berm design for very shallow waters on steep sea bottoms. Coastal Engineering, 103, 67-77. doi:10.1016/j.coastaleng.2015.06.005Herrera, M. P., Molines, J., & Medina, J. R. (2016). Hydraulic stability of nominal and sacrificial toe berms for mound breakwaters on steep sea bottoms. Coastal Engineering, 114, 361-368. doi:10.1016/j.coastaleng.2016.05.00

    Social Organizational Life Cycle Assessment (SO-LCA) and Organization 4.0: An easy-to-implement method

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    Organizations often face difficulties when measuring their social performance. The lack of international standards, the qualitative/quantitative nature of data, and the unavailability of primary sources all hinder social impact assessments, especially in manufacturing settings. To fill these gaps, the method proposes a simple application protocol of Social Organizational Life Cycle Assessment (SO-LCA), customized for an Italian ceramic tile manufacturer. The method leverages Industry 4.0 digital technologies to collect real-time primary and site-specific social data, making the social assessment dynamic. The managerial approach adopted for the selection of social metrics and weighting of indicators and indexes, can support the transition of the manufacturing organization into Organization 4.0. The method also provides a contribution to the operational validation of the UNEP guidelines by extending their area of application. Finally, the proposed method gives substance to social responsibility through social accounting, helping the organization to measure the correct social impact starting from the detailed data, namely the decisions made in the business and in production. • Social Organizational Life Cycle Assessment (SO-LCA) application protocol validated in Industry 4.0 environment. • Social metrics directly linked to production and business processes for the dynamic assessment of social performance. • Easy replicability of the method in other organizational contexts

    Soft leptogenesis in the inverse seesaw model

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    We consider leptogenesis induced by soft supersymmetry breaking terms ("soft leptogenesis"), in the context of the inverse seesaw mechanism. In this model there are lepton number (L) conserving and L-violating soft supersymmetry-breaking B-terms involving the singlet sneutrinos which, together with the -- generically small-- L-violating parameter responsible of the neutrino mass, give a small mass splitting between the four singlet sneutrino states of a single generation. In combination with the trilinear soft supersymmetry breaking terms they also provide new CP violating phases needed to generate a lepton asymmetry in the singlet sneutrino decays. We obtain that in this scenario the lepton asymmetry is proportional to the L-conserving soft supersymmetry-breaking B-term, and it is not suppressed by the L-violating parameters. Consequently we find that, as in the standard see-saw case, this mechanism can lead to sucessful leptogenesis only for relatively small value of the relevant soft bilinear coupling. The right-handed neutrino masses can be sufficiently low to elude the gravitino problem. Also the corresponding Yukawa couplings involving the lightest of the right-handed neutrinos are constrained to be \sum |Y_{1k}|^2\lesssim 10^{-7} which generically implies that the neutrino mass spectrum has to be strongly hierarchical.Comment: 28 pages, 1 figure; some references added; final version to appear in JHE

    Presentación, clasificación y evolución de los pacientes con carcinoma hepatocelular en un centro de Veracruz, México

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    ResumenAntecedentesLa estadificación en el carcinoma hepatocelular (CHC) otorga pronóstico y orientación terapéutica. La resección y el trasplante hepático son opciones curativas y las terapias de ablación se aplican a pacientes que no reciben tratamiento curativo. La sobrevida tras la resección hepática o terapias de ablación es variada.ObjetivoDescribir la presentación, la estadificación, el manejo y la evolución de los pacientes con CHC en nuestro centro.Pacientes y métodosCuarenta y dos pacientes fueron seguidos prospectivamente durante 7 años. La sobrevida se calculó mediante Kaplan-Meier y log-rank entre los sistemas de estadificación (Okuda, BCLC y CLIP) y tipos de tratamiento (resección hepática, ablación por radiofrecuencia y ningún tratamiento quirúrgico).ResultadosLa edad media ± desviación estándar de los pacientes fue 68,9 ± 9,5 años; el 57% fueron mujeres y el 54% cirróticos. El 31% tenía infección por VHC. El tamaño medio del tumor fue 6.48 ± 2.52cm. Los estadios CLIP 0, Okuda I y BCLC A tuvieron mejor sobrevida que otros estadios (p<0.05). La resección tuvo mejor sobrevida (mediana: 32 meses y sobrevida a 1, 3 y 5 años del 83, el 39 y 19.7%) que ablación por radiofrecuencia (25 meses, y el 90 y el 17.2% a 1 y 3 años) y que ningún tratamiento quirúrgico (1 año<5%) (p<0.05).ConclusiónLos pacientes con CHC en nuestro centro al igual que otra población en México son diagnosticados tardíamente. El pronóstico usando CLIP y BCLC es similar a la literatura. Los mejores resultados se observaron en estadios tempranos y los que tuvieron resección quirúrgica del CHC.AbstractBackgroundHepatocellular carcinoma (HCC) staging provides a basis for calculating disease prognosis and therapeutic guidance. Liver resection and transplantation are curative options, and ablation therapies are applied to patients that are not candidates for curative treatment. Survival after liver resection or ablation therapies varies.AimsTo describe the presentation, staging, management, and outcome in patients with HCC in our center.Patients and methodsForty-two patients had a 7-year prospective follow-up. Survival was calculated with the Kaplan-Meier analysis and the log-rank test was used for its comparison between the staging systems (Okuda, BCLC, and CLIP) and types of treatment (liver resection, radiofrequency ablation, and no surgical treatment).ResultsThe mean age of the patients was 68.9 ± 9.5 years; 57% were women. A total of 54% of the patients presented with cirrhosis and 31% were infected with hepatitis C virus (HCV). The mean tumor size was 6.48 ± 2.52cm. The CLIP 0, Okuda I, and BCLC A stages had better survival rates than the other stages (P<0.05). Survival with resection was superior (median of 32 months and survival at 1, 3, and 5 years of 83, 39, and 19.7%, respectively) to that of both radiofrequency ablation (median of 25 months and survival at 1 and 3 years of 90 and 17.2%, respectively) and no surgical treatment (1 year < 5%) (P<0.05).ConclusionThe patients at our center were diagnosed at late stages of HCC, as is the case in other Mexican populations. Outcome in relation to CLIP and BCLC was similar to the prognoses reported in the literature. The best results were observed in the patients with early stage disease and those that underwent HCC resection surgery

    On the statistics of superlocalized states in self-affine disordered potentials

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    We investigate the statistics of eigenstates in a weak self-affine disordered potential in one dimension, whose Gaussian fluctuations grow with distance with a positive Hurst exponent HH. Typical eigenstates are superlocalized on samples much larger than a well-defined crossover length, which diverges in the weak-disorder regime. We present a parallel analytical investigation of the statistics of these superlocalized states in the discrete and the continuum formalisms. For the discrete tight-binding model, the effective localization length decays logarithmically with the sample size, and the logarithm of the transmission is marginally self-averaging. For the continuum Schr\"odinger equation, the superlocalization phenomenon has more drastic effects. The effective localization length decays as a power of the sample length, and the logarithm of the transmission is fully non-self-averaging.Comment: 21 pages, 6 figure

    THE HIGH CADENCE TRANSIENT SURVEY (HITS). I. SURVEY DESIGN AND SUPERNOVA SHOCK BREAKOUT CONSTRAINTS

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    Indexación: Web of Science; Scopus.We present the first results of the High Cadence Transient Survey (HiTS), a survey for which the objective is to detect and follow-up optical transients with characteristic timescales from hours to days, especially the earliest hours of supernova (SN) explosions. HiTS uses the Dark Energy Camera and a custom pipeline for image subtraction, candidate filtering and candidate visualization, which runs in real-time to be able to react rapidly to the new transients. We discuss the survey design, the technical challenges associated with the real-time analysis of these large volumes of data and our first results. In our 2013, 2014, and 2015 campaigns, we detected more than 120 young SN candidates, but we did not find a clear signature from the short-lived SN shock breakouts (SBOs) originating after the core collapse of red supergiant stars, which was the initial science aim of this survey. Using the empirical distribution of limiting magnitudes from our observational campaigns, we measured the expected recovery fraction of randomly injected SN light curves, which included SBO optical peaks produced with models from Tominaga et al. (2011) and Nakar & Sari (2010). From this analysis, we cannot rule out the models from Tominaga et al. (2011) under any reasonable distributions of progenitor masses, but we can marginally rule out the brighter and longer-lived SBO models from Nakar & Sari (2010) under our best-guess distribution of progenitor masses. Finally, we highlight the implications of this work for future massive data sets produced by astronomical observatories, such as LSST.http://iopscience.iop.org/article/10.3847/0004-637X/832/2/155/meta;jsessionid=76BDFFFE378003616F6DBA56A9225673.c4.iopscience.cld.iop.or
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