381 research outputs found
Search for dark matter annihilation in the center of the Earth with 8 years of IceCube data
Dark matter particles in the galactic halo can scatter off particles in
celestial bodies such as stars or planets, lose energy and become
gravitationally trapped. In this process, an accumulation of dark matter in the
center of celestial bodies is expected, for example, at the center of the
Earth. If dark matter self-annihilates into Standard Model particles, the end
products of these annihilations include neutrinos. The IceCube Neutrino
Observatory at the geographic South Pole can detect the resulting flux of
neutrinos originating from dark matter annihilation in the center of the Earth.
A search for this signal is on-going using 8 years of IceCube data and probing
different annihilation channels. Here the sensitivities are presented for this
new analysis, showing significant improvements with respect to the previous
analyses from IceCube and other experiments.Comment: Presented at the 36th International Cosmic Ray Conference (ICRC
2019). See arXiv:1907.11699 for all IceCube contribution
Influence of Soil-Structure Interaction on Seismic Response of Shear Buildings
The beneficial or detrimental effect of dynamic Soil-Structure Interaction (SSI) is a controversial issue. With reference to an idealized R/C shear building, a comprehensive comparison between the results obtained with a classical fixed-base analysis and a complete SSI analysis is provided in the present paper. The shear-type structure is modeled as generalized Single Degree Of Freedom (SDOF) system using the principle of virtual displacements. The foundation consists of surface square foundations resting on different soil conditions, consistent with the provisions of EC8-part I. SSI effects in the far-field of earthquakes was evaluated by direct application of the elastic pseudo-acceleration/displacement design spectra proposed in EC8, taking into account the change in natural period and damping of the soil-structure system. SSI effect in near-field area of earthquakes was analyzed using the computer program SASSI2000 (Lysmer et al., 1999), by means of a set of ten actual earthquakes recorded within a distance of 20 km from fault The proposed analyses can be easily used by consultants who want to face the task of SSI in an immediate and simplified manner, without devoting resources into complex analysis. The charts proposed in this paper could be incorporated in seismic guidelines
Fully Bio-Based Nanocomposite: Formulations For Packaging Application
The effect of a small amount of organoclay (OMMT) on mechanical, dynamic-mechanical, barrier and thermal properties of blown films based on blends of poly(lactic acid) (PLA) and polyamide 11 (PA11) was investigated. The addition of PA11 results in a decrease of elastic modulus (E) and tensile strength (ÏR) compared to neat PLA, which suggests poor interfacial adhesion between the polymer phases.
Besides an enhancement of E and ÏR, the addition of 1 wt% of OMMT brings about a significant increase of the elongation at break.
Neither blending with PA11 nor adding OMMT cause appreciable alterations of the barrier properties of the films, which remain essentially the same as those of pure PLA. Thermogravimetric analysis reveals that the onset of thermal degradation of the OMMT-filed blend is 15°C higher than of neat PLA. This improvement is probably due to the labyrinth effect of the PA11 phase. Finally, the OMMT brings about a slight enhancement of the glassy modulus compared to the unfilled blend, which suggests that the clay may exert some compatibilizing action. Such a beneficial effect of the OMMT endures up to the glass transition of PLA.
he testing methods such as CCT, RCT, FCT, COBB, bursting etc. are supported by statistical technique and do not provide accurate results. The reason is the deviation of testing results. The same problem can be defined at the classification of different paper materials and qualities. This paper describes a new possible testing method to analyze the chemical and thermo-analytical nature of papers. This method can be used to specify effectively the limits of a given paper quality using in packaging industry and can help to ensure the exact traceability of paper identification. The results show that the this method on the one hand can be helpful to testing the paper during packaging producing process on the other hand after using as a packaging. To the testing a DSC measurement device was used as a thermo-analytical method to observe new specifics of paper based packaging
Embedding sustainability in risk management: The impact of environmental, social, and governance ratings on corporate financial risk
This study investigates the effect of corporate social and environmental evaluation on investorsâ risk perception to explore the potential market risk for public companies that adopt a sustainable and responsible corporate strategy. We referred to the triple corporate assessment according to environmental, social, and governance (ESG) criteria to check whether ESG factorsâmeant to direct firms toward social and environmental needsâimprove corporate market performance or trigger, among investors, a perception of âwindow dressing.â In doing so, we tested the impact of corporate social performanceâproxied by an ESG assessmentâon corporate financial risk using double risk measurement. We conducted a five-year longitudinal study (fiscal years 2014â2018) of 222 companies listed on the Standard & Poorâs index. The empirical findings show higher investor uncertainty regarding corporate sustainability performance, probably due to the misalignment of objectives between investors and investees. Indeed, an overall ESG assessment corresponds to higher systematic risk for firms, and a corporate environmental rating has an upward effect on the same risk dimension
Turbulent blood dynamics in the left heart in the presence of mitral regurgitation: a computational study based on multi-series cine-MRI
In this work, we performed a computational image-based study of blood dynamics in the whole left heart, both in a healthy subject and in a patient with mitral valve regurgitation. We elaborated multi-series cine-MRI with the aim of reconstructing the geometry and the corresponding motion of left ventricle, left atrium, mitral and aortic valves, and aortic root of the subjects. This allowed us to prescribe such motion to computational blood dynamics simulations where, for the frst time, the whole left heart motion of the subject is considered, allowing us to obtain reliable subject-specifc information. The fnal aim is to investigate and compare between the subjects the occurrence of turbulence and the risk of hemolysis and of thrombi formation. In particular, we modeled blood with the NavierâStokes equations in the arbitrary LagrangianâEulerian framework, with a large eddy simulation model to describe the transition to turbulence and a resistive method to manage the valve dynamics, and we used a fnite element discretization implemented in an in-house code for the numerical solution
Arterial Pressure Management in a Reconstructive Microsurgery Patients by Dopamine Infusion in a Nonintensive Care Ward
Free flap perfusion and arterial pressure management have always had a crucial role in free flap reconstruction. Blood pressure values requested can be reached either by using vasoactive agents or fluid replacement or the combination of both.1,2
In contrast to the most frequently tested phenylephrine, norepinephrine, and dobutamine,3,4 this work evaluates dopamine efficacy in perioperative blood pressure management.
In our institution, dopamine infusion is the only vasoactive agent authorized in a non-intensive care unit department. This drug stimulates \u3b1- and \u3b2-adrenergic receptors with positive chronotropic and inotropic effects and reduces peripheral vascular resistance helping in this way to achieve an increase of blood pressure and free flap perfusion.
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