Modeling of system knowledge for efficient agile manufacturing : tool evaluation, selection and implementation scenario in SMEs

In the manufacturing world, knowledge is fundamental in order to achieve effective and efficient real time decision making. In order to make manufacturing system knowledge available to the decision maker it has to be first captured and then modelled. Therefore tools that provide a suitable means for capturing and representation of manufacturing system knowledge are required in several types of industrial sectors and types of company’s (large, SME). A literature review about best practice for capturing requirements for simulation development and system knowledge modeling has been conducted. The aim of this study was to select the best tool for manufacturing system knowledge modelling in an open-source environment. In order to select this tool, different criteria were selected, based on which several tools were analyzed and rated. An exemplary use case was then developed using the selected tool, Systems Modeling Language (SysML). Therefore, the best practice has been studied, evaluated, selected and then applied to two industrial use cases by the use of a selected opens source tool.peer-reviewe

Information support and interactive planning in the digital factory : approach and industry-driven evaluation

In the modern world we are continuously surrounded by information. The human brain has to analyse and interpret this information to transform into useable knowledge that is then used in decision making activities. The advent and implementation of Industry 4.0 will make it a requirement for systems within factories to interact and share large quantities of information with each other. This large volume of information will make it even more difficult for the human resources within the factory to sift through the large amount of information required since there is a limit to the information that our brains can cope with. Just in time information retrieval (JITIR) within the digital factory environment aims to provide support to the human stakeholders in the system by proactively yet non-intrusively providing the required information at the right time based on the users context. This paper will therefore provide an insight into the cognitive difficulties experienced by humans in the digital factory and how JITIR can tackle these challenges. By validating the JITIR concept, several industry scenarios have been evaluated: an exemplary model, concerning the machine tool industry, is presented in the paper. The results of this research are a set of guidelines for the development of a digital factory support tool.peer-reviewe

Unstable states in QED of strong magnetic fields

We question the use of stable asymptotic scattering states in QED of strong magnetic fields. To correctly describe excited Landau states and photons above the pair creation threshold the asymptotic fields are chosen as generalized Licht fields. In this way the off-shell behavior of unstable particles is automatically taken into account, and the resonant divergences that occur in scattering cross sections in the presence of a strong external magnetic field are avoided. While in a limiting case the conventional electron propagator with Breit-Wigner form is obtained, in this formalism it is also possible to calculate $S$-matrix elements with external unstable particles.Comment: Revtex, 7 pages. To appear in Phys. Rev. D53(2

An effective singular oscillator for Duffin-Kemmer-Petiau particles with a nonminimal vector coupling: a two-fold degeneracy

Scalar and vector bosons in the background of one-dimensional nonminimal vector linear plus inversely linear potentials are explored in a unified way in the context of the Duffin-Kemmer-Petiau theory. The problem is mapped into a Sturm-Liouville problem with an effective singular oscillator. With boundary conditions emerging from the problem, exact bound-state solutions in the spin-0 sector are found in closed form and it is shown that the spectrum exhibits degeneracy. It is shown that, depending on the potential parameters, there may or may not exist bound-state solutions in the spin-1 sector.Comment: 1 figure. arXiv admin note: substantial text overlap with arXiv:1009.159

Influence of Bed Roughness on Flow and Turbulence Structure Around a Partially-Buried, Isolated Freshwater Mussel

The present study uses eddy-resolving numerical simulations to investigate how bed roughness affects flow and turbulence structure around an isolated, partially-buried mussel (Unio elongatulus) aligned with the incoming flow. The rough-bed simulations resolve the flow past the exposed part of a gravel bed, whose surface is obtained from a laboratory experiment that also provides some additional data for validation of the numerical model. Results are also discussed for the limiting case of a horizontal smooth bed. Additionally, the effects of varying the level of burial of the mussel inside the substrate and the discharge through the two mussel siphons are investigated via a set of simulations in which the ratio between the median diameter of the (gravel) particles forming the rough bed, d50, and the height of the exposed part of the mussel, h, varies between 0.10 and 0.22. The increase of the bed roughness is associated with a strong amplification of the turbulence kinetic energy in the near-wake region. Increasing the bed roughness and/or reducing h intensifies the interactions of the eddies generated by the bed particles with the base and tip vortices induced by the active filtering and by the mussel shell, respectively, which, in turn, induces a more rapid dissipation of these vortices. Increasing the bed roughness also reduces the strength of the main downwelling flow region forming in the wake. The strong downwelling near the symmetry plane is the main reason why the symmetric wake shedding mode dominates in the smooth bed simulations with negligible active filtering. By contrast, the anti-symmetric wake shedding mode dominates in the simulations conduced with a high value of the bed roughness. The mean streamwise drag force coefficient for the emerged part of the shell and the dilution of the excurrent siphon jet increase with increasing bed roughness

Cerebrospinal Fluid Biomarkers of Synaptic Dysfunction Are Altered in Parkinson's Disease and Related Disorders

Background: Synaptic dysfunction and degeneration are central contributors to the pathogenesis and progression of parkinsonian disorders. Therefore, identification and validation of biomarkers reflecting pathological synaptic alterations are greatly needed and could be used in prognostic assessment and to monitor treatment effects. Objective: To explore candidate biomarkers of synaptic dysfunction in Parkinson's disease (PD) and related disorders. Methods: Mass spectrometry was used to quantify 15 synaptic proteins in two clinical cerebrospinal fluid (CSF) cohorts, including PD (n1 = 51, n2 = 101), corticobasal degeneration (CBD) (n1 = 11, n2 = 3), progressive supranuclear palsy (PSP) (n1 = 22, n2 = 21), multiple system atrophy (MSA) (n1 = 31, n2 = 26), and healthy control (HC) (n1 = 48, n2 = 30) participants, as well as Alzheimer's disease (AD) (n2 = 23) patients in the second cohort. Results: Across both cohorts, lower levels of the neuronal pentraxins (NPTX; 1, 2, and receptor) were found in PD, MSA, and PSP, compared with HC. In MSA and PSP, lower neurogranin, AP2B1, and complexin-2 levels compared with HC were observed. In AD, levels of 14-3-3 zeta/delta, beta- and gamma-synuclein were higher compared with the parkinsonian disorders. Lower pentraxin levels in PD correlated with Mini-Mental State Exam scores and specific cognitive deficits (NPTX2; rho = 0.25–0.32, P < 0.05) and reduced dopaminergic pre-synaptic integrity as measured by DaTSCAN (NPTX2; rho = 0.29, P = 0.023). Additionally, lower levels were associated with the progression of postural imbalance and gait difficulty symptoms (All NPTX; β-estimate = −0.025 to −0.038, P < 0.05) and cognitive decline (NPTX2; β-estimate = 0.32, P = 0.021). Conclusions: These novel findings show different alterations of synaptic proteins in parkinsonian disorders compared with AD and HC. The neuronal pentraxins may serve as prognostic CSF biomarkers for both cognitive and motor symptom progression in PD. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society

Thomas-Fermi Calculations of Atoms and Matter in Magnetic Neutron Stars II: Finite Temperature Effects

We present numerical calculations of the equation of state for dense matter in high magnetic fields, using a temperature dependent Thomas-Fermi theory with a magnetic field that takes all Landau levels into account. Free energies for atoms and matter are also calculated as well as profiles of the electron density as a function of distance from the atomic nucleus for representative values of the magnetic field strength, total matter density, and temperature. The Landau shell structure, which is so prominent in cold dense matter in high magnetic fields, is still clearly present at finite temperature as long as it is less than approximately one tenth of the cyclotron energy. This structure is reflected in an oscillatory behaviour of the equation of state and other thermodynamic properties of dense matter and hence also in profiles of the density and pressure as functions of depth in the surface layers of magnetic neutron stars. These oscillations are completely smoothed out by thermal effects at temperatures of the order of the cyclotron energy or higher.Comment: 37 pages, 17 figures included, submitted to Ap

On the crack path under mixed mode loading on PUR foams

&nbsp;In this paper are presented the crack initiation angles obtained in polyurethane (PUR) foams under mixedmode loading. Closed cell rigid PUR foams having three different densities 100, 145, and 300 kg/m3 were investigated.Experiments were performed using Asymmetric Semi-Circular Bend and Single Edge Crack specimens.The obtained crack initiation values were compared with four fracture criteria to introduce: Maximum Tensile Stress, Strain Energy Density, Maximum Energy Release Rate and Equivalent Stress Intensity Factor, and a good agreement was observed. This allow to conclude that the theoretical fracture criteria developed for solid material could be used with success to predict the crack propagation angles in cellular materials like PUR foams.&nbsp

GREEN ENERGY - THE FUTURE ENERGY WITHIN BIOTERRA UNIVERSITY CAMPUS

Green energies are widely implemented worldwide and also in our country. Our paper provides its applicability in  terms of  facilities within Bioterra University central campus in Bucharest and also in our Tourist and Students Practice Units located in Predeal – "TreiBrazi", Buşteni –" Zamora" , Danube Delta –"Baltenii de Sus" and at the Seaside - EforieSud and Comorova Forest, Neptun resort (all being owned by Bioterra University of Bucharest).At the United Nations Conference in Paris (held on 12 December 2015) regarding the  Climate change,  the partners   reached a New Global Climate change Agreement: limiting global warming, well below 2 Celsius degrees, underlining the importance of using of the non-polluting renewable energies. Beyond this limit, the scientists fear of the next irreversible effects:- repeated extreme events - cyclones, droughts, etc.;- decline of agricultural yields;- extinction of some species. Rising with +2 Celsius degrees, the sea level will increase with 40 cm till 2100 year; rising with + 4-5 Celsius degrees, the sea level will increasewith 80 cm and it will continue to ascend