Existence, comparison, and convergence results for a class of elliptic hemivariational inequalities

In this paper we study a class of elliptic boundary hemivariational inequalities which originates in the steady-state heat conduction problem with nonmonotone multivalued subdifferential boundary condition on a portion of the boundary described by the Clarke generalized gradient of a locally Lipschitz function. First, we prove a new existence result for the inequality employing the theory of pseudomonotone operators. Next, we give a result on comparison of solutions, and provide sufficient conditions that guarantee the asymptotic behavior of solution, when the heat transfer coefficient tends to infinity. Further, we show a result on the continuous dependence of solution on the internal energy and heat flux. Finally, some examples of convex and nonconvex potentials illustrate our hypotheses.Comment: 22 page

The effect of the calculation method, plot size, and stand density on the accuracy of top height estimation in Norway spruce stands

The aim of this study was to evaluate top height (TH) estimates for Norway spruce stands calculated according to different computational methods, and to assess the effects of stand density and plot size on TH estimation accuracy. Field data were collected from twelve 1 ha research plots located in even-aged spruce stands. Conventional estimates were found to generally overstate TH. The accuracy of TH estimation was dependent on sample plot size. TH estimation error decreased rapidly with increasing sample plot area, but only up to a certain cut-off point. Errors in TH estimation were also related to local stand density, with low and very high density levels leading to decreased accuracy. The most reliable TH estimates were obtained using the U-estimator method, which is resistant to changes in sample plot size

Analysis of results from current collector monitoring system under real traffic conditions on a railway line

W celu oceny stanu technicznego odbieraków prądu prowadzone jest ich monitorowanie podczas przejazdu pociągu przez stanowisko kontrolne na linii kolejowej. Stanowisko monitoringu rejestruje uniesienie przewodów jezdnych wywołane oddziaływaniem odbieraka, prędkość pojazdu i jego dane identyfikacyjne. Na podstawie pomiarów i kryteriów oceny następuje klasyfikacja stanu technicznego odbieraków. Przeprowadzono weryfikację wyników monitoringu. Podano zestawienie statystyczne prowadzonych pomiarów

A model of a spring-mass-damper system with temperature-dependent friction

International audienceThis work models and analyses the dynamics of a general spring-mass-damper system that is in frictional contact with its support, taking into account frictional heat generation and a reactive obstacle. Friction, heat generation and contact are modelled with subdifferentials of, possibly non-convex, potential functions. The model consists of a non-linear system of first-order differential inclusions for the position, velocity and temperature of the mass. The existence of a global solution is established and additional assumptions yield its uniqueness. Nine examples of conditions arising in applications, for which the analysis results are valid, are presented

Existence, comparison, and convergence results for a class of elliptic hemivariational inequalities

In this paper we study a class of elliptic boundary hemivariational inequalities which originates in the steady-state heat conduction problem with nonmonotone multivalued subdifferential boundary condition on a portion of the boundary described by the Clarke generalized gradient of a locally Lipschitz function. First, we prove a new existence result for the inequality employing the theory of pseudomonotone operators. Next, we give a result on comparison of solutions, and provide sufficient conditions that guarantee the asymptotic behavior of solution, when the heat transfer coefficient tends to infinity. Further, we show a result on the continuous dependence of solution on the internal energy and heat flux. Finally, some examples of convex and nonconvex potentials illustrate our hypotheses

The microstructure and thermal properties of Yb2SiO5 coating deposited using APS and PS-PVD methods

Purpose: The new ceramic material for Enviromental Barrier Coatings (EBC) on ceramic material was developed. Design/methodology/approach: The ytterbium monosilicate was deposited using two methods: atmospheric plasma spray (APS) and plasma spray physical vapour deposition (PS-PVD). Findings: Obtained coating was characterized by dense structure and columns typically formed in PS-PVD process were not observed. In comparison with APS-deposited coating, in this method, both elements segregation and formation of ytterbium oxide occurred. Research limitations/implications: The further research for production of columnar coatings will be necessary. Practical implications: Developed coatings migh be used for next generations of ceramic materials used for gas turbine and jet engine blades and vanes as a high temperature and corrosion protection. Originality/value: The first time the ytterbium monosilicate was produced bot by APS and LPPS methods

Large plexiform neurofibroma on right thigh of a farmer in the course of Recklinghausen disease - Case report

A 59-year-old farmer was admitted to the Department of Trauma Surgery because of pain associated with the presence of a tumour on the side of the right thigh. The patient stated that his biggest problem was great difficulty in moving and handling agricultural machinery due to the aforementioned lesion. On physical examination, the patient presented with numerous cutaneous and subcutaneous neurofibromas, as well as one large plexiform neurofibroma. Diagnosis of Neurofibromatosis type 1 was established, based on National Institutes of Health diagnostic criteria. Moreover, molecular genetic testing found known pathogenic mutation p.Arg1769* in one of the alleles of NF1 gene (heterozygote), typical for Recklinghausen disease. The big plexiform neurofibroma in the patient was not operated on because of lung cancer