Randomness representation of turbulence in canopy flows using Kolmogorov complexity measures

Turbulence is often expressed in terms of either irregular or random fluid flows, without quantification. In this paper, a methodology to evaluate the randomness of the turbulence using measures based on the Kolmogorov complexity (KC) is proposed. This methodology is applied to experimental data from a turbulent flow developing in a laboratory channel with canopy of three different densities. The methodology is even compared with the traditional approach based on classical turbulence statistics

Characterization of hyporheic exchange drivers and patterns within a low-gradient, first-order, river confluence during low and high flow

Confluences are nodes in riverine networks characterized by complex three-dimensional changes in flow hydrodynamics and riverbed morphology, and are valued for important ecological functions. This physical complexity is often investigated within the water column or riverbed, while few studies have focused on hyporheic fluxes, which is the mixing of surface water and groundwater across the riverbed. This study aims to understand how hyporheic flux across the riverbed is organized by confluence physical drivers. Field investigations were carried out at a low gradient, headwater confluence between Baltimore Brook and Cold Brook in Marcellus, New York, USA. The study measured channel bathymetry, hydraulic permeability, and vertical temperature profiles, as indicators of the hyporheic exchange due to temperature gradients. Confluence geometry, hydrodynamics, and morphodynamics were found to significantly affect hyporheic exchange rate and patterns. Local scale bed morphology, such as the confluence scour hole and minor topographic irregularities, influenced the distribution of bed pressure head and the related patterns of downwelling/upwelling. Furthermore, classical back-to-back bend planform and the related secondary circulation probably affected hyporheic exchange patterns around the confluence shear layer. Finally, even variations in the hydrological conditions played a role on hyporheic fluxes modifying confluence planform, and, in turn, flow circulation patterns

Gravitational signals emitted by a point mass orbiting a neutron star: effects of stellar structure

The effects that the structure of a neutron star would have on the gravitational emission of a binary system are studied in a perturbative regime, and in the frequency domain. Assuming that a neutron star is perturbed by a point mass moving on a close, circular orbit, we solve the equations of stellar perturbations in general relativity to evaluate the energy lost by the system in gravitational waves. We compare the energy output obtained for different stellar models with that found by assuming that the perturbed object is a black hole with the same mass, and we discuss the role played by the excitation of the stellar modes. Ouresults indicate that the stellar structure begins to affect the emitted power when the orbital velocity is v >0.2c (about 185 Hz for a binary system composed of two canonical neutron stars). We show that the differences between different stellar models and a black hole are due mainly to the excitation of the quasinormal modes of the star. Finally, we discuss to what extent and up to which distance the perturbative approach can be used to describe the interaction of a star and a pointlike massive body.Comment: 22 pages, 6 figures, to appear in Phys. Rev. D. Revised version, added one table and extended discussio

Contact Tank Design Impact on Process Performance

In this study three-dimensional numerical models were refined to predict reactive processes in disinfection contact tanks (CTs). The methodology departs from the traditional performance assessment of contact tanks via hydraulic efficiency indicators, as it simulates directly transport and decay of the disinfectant, inactivation of pathogens and accumulation of by-products. The method is applied to study the effects of inlet and compartment design on contact tank performance, with special emphasis on turbulent mixing and minimisation of internal recirculation and short-circuiting. In contrast to the conventional approach of maximising the length-to-width ratio, the proposed design changes are aimed at addressing and mitigating adverse hydrodynamic structures, which have historically led to poor hydraulic efficiency in many existing contact tanks. The results suggest that water treatment facilities can benefit from in-depth analyses of the flow and kinetic processes through computational fluid dynamics, resulting in up to 38 % more efficient pathogen inactivation and 14 % less disinfection by-product formation

an evaluation methodology for the conversion of manual assembly systems into human robot collaborative workcells

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Are Post-Newtonian templates faithful and effectual in detecting gravitational signals from neutron star binaries?

We compute the overlap function between Post-Newtonian (PN) templates and gravitational signals emitted by binary systems composed of one neutron star and one point mass, obtained by a perturbative approach. The calculations are performed for different stellar models and for different detectors, to estimate how effectual and faithful the PN templates are, and to establish whether effects related to the internal structure of neutron stars may possibly be extracted by the matched filtering technique.Comment: 14 pages, 3 figures, accepted for publication in Phys. Rev.

Oral cavity reconstruction with the masseter flap.

The purpose of this report is to highlight how an unusual, outdated, unpopular and overlooked reconstructive method such as the masseter flap can be a reliable, straightforward and effective solution for oral reconstruction in selected cases. We report the transposition of the masseter crossover flap in two previously pre-treated patients presenting a second primary oral squamous cell carcinoma; excellent functional results with satisfactory cosmetic appearance were obtained in both cases. In the literature, only 60 cases of oral cavity and oropharyngeal reconstructions using the masseter flap have been reported. The possible clinical utility of this flap, even in modern head and neck reconstructive surgery, is presented and discussed. We believe that the masseter flap should enter in the armamentarium of every head and neck surgeon and be kept in mind as a possible solution since it provides an elegant and extremely simple procedure in suboptimal cases for microvascular reconstruction

The quality of work dimensions. Results of a multivariate analysis from the Third Isfol Survey on Quality of work in Italy

This paper starts with an overview of the theoretical framework on quality of work and identifies five relevant dimensions, in line with Gallino & La Rosa: ergonomic, complexity, autonomy, control and economic dimensions. The above dimensions are described and measured by means of multivariate analysis to detect differences in terms of the factors affecting the level of the quality of work dimensions achieved. The data set that we use for this purpose is the Third Isfol Survey on Quality of Work (IsfolQdL) that has been carried out in 2010 on a sample of 5,000 workers and operationalizes the five dimensions of the quality of work. The results of the multivariate analysis confirm the worse achievements in terms of quality of work by temporary workers and lower skilled workers and lower level of achievements by women in the economic and autonomy dimensions. Women are also more likely to be found in part-time work positions and the latter show an improvement in the ergonomic dimension (that includes also work life balance) at the expenses of the economic and autonomy dimensions

Modeling the iron oxides and oxyhydroxides for the prediction of environmentally sensitive phase transformations

Iron oxides and oxyhydroxides are challenging to model computationally as competing phases may differ in formation energies by only several kJ/mol, they undergo magnetization transitions with temperature, their structures may contain partially occupied sites or long-range ordering of vacancies, and some loose structures require proper description of weak interactions such as hydrogen bonding and dispersive forces. If structures and transformations are to be reliably predicted under different chemical conditions, each of these challenges must be overcome simultaneously, while preserving a high level of numerical accuracy and physical sophistication. Here we present comparative studies of structure, magnetization, and elasticity properties of iron oxides and oxyhydroxides using density functional theory calculations with plane-wave and locally-confined-atomic-orbital basis sets, which are implemented in VASP and SIESTA packages, respectively. We have selected hematite, maghemite, goethite, lepidocrocite, and magnetite as model systems from a total of 13 known iron oxides and oxyhydroxides; and use same convergence criteria and almost equivalent settings in order to make consistent comparisons. Our results show both basis sets can reproduce the energetic stability and magnetic ordering, and are in agreement with experimental observations. There are advantages to choosing one basis set over the other, depending on the intended focus. In our case, we find the method using PW basis set most appropriate, and combine our results to construct the first phase diagram of iron oxides and oxyhydroxides in the space of competing chemical potentials, generated entirely from first principlesComment: 46 pages - Accepted for publication in PRB (19 journal pages), January 201

Function-Based Mapping of Industrial Assistance Systems to User Groups in Production

Abstract By looking at the last few decades, industrial production has undergone great changes. Industry 4.0, also called the fourth industrial revolution, describes the change in the entire value chain through the digital networking of systems, machines, and products. In addition, product variety and complexity in assembly increased due to customization. Big Data Analytics, Internet of Things, Horizontal and Vertical Data Integration and Cyber-Physical Production Systems are just some examples of technologies that find their way from research into industrial practice. However, the most important resource is often neglected, when talking about industry: the human. When we look at companies, we find different types of personnel in production, each with different requirements and capabilities. Assistance systems can be used to counteract these new challenges and offer adequate support to each individual worker. In the past, much research has been done to develop new worker assistance systems, while the analysis of specific needs of user groups in production has been ignored. This paper presents a function-based mapping of industrial worker assistance systems to different user groups and proposes a method for selecting the most appropriate assistance system to each user group