238 research outputs found

    Effect of preliminary vacuum plasma treatment on coating adhesion

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    The paper presents research results on the adhesion properties of Si coatings synthesized by different methods and under different conditions of preliminary vacuum ion plasma treatment of substrates with subsequent magnetron sputtering. The substrate surface was pretreated with low-energy ion beams, high-energy ion beams, gas discharge plasma, and plasma produced by a magnetron sputtering system. The vacuum conditions (pump type, pressure, etc.), the ion current density, and the bias parameters (pulse repetition frequency and duration) were varied. The research results demonstrate a considerable effect of plasma immersion ion implantation on the adhesion of Si coatings to NiTi substrates

    Effect of bias voltage on coating homogeneity in plasma immersion ion implantation

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    The paper presents research results demonstrating the influence of bias on the homogeneity of plasma immersion ion implantation. The research results allow the conclusion that plasma immersion ion implantation can be used to advantage for surface modification of medical materials, e.g., nickel-titanium (NiTi) alloys. In particular, doing of NiTi with silicon at pulsed bias provides highly homogeneous surface treatment

    Plasma immersion ion implantation for the efficient surface modification of medical materials

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    The paper reports on a new method of plasma immersion ion implantation for the surface modification of medical materials using the example of nickel-titanium (NiTi) alloys much used for manufacturing medical implants. The chemical composition and surface properties of NiTi alloys doped with silicon by conventional ion implantation and by the proposed plasma immersion method are compared. It is shown that the new plasma immersion method is more efficient than conventional ion beam treatment and provides Si implantation into NiTi surface layers through a depth of a hundred nanometers at low bias voltages (400 V) and temperatures (≤150°C) of the substrate. The research results suggest that the chemical composition and surface properties of materials required for medicine, e.g., NiTi alloys, can be successfully attained through modification by the proposed method of plasma immersion ion implantation and by other methods based on the proposed vacuum equipment without using any conventional ion beam treatment

    Analiza prikaza digitalnih modela terena primjenom različitih metoda interpolacije

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    In the paper is described the process of creating digital terrain models (DTM) using different interpolation methods. The analyses show the accuracy of the DTM obtained from topographic maps at different scales and using different interpolation methods. The quality and accuracy of DTM depends on the complexity of the terrain, data sources, and methods of height interpolation. The basic idea is the creation of the DTM for the selected area and the comparison of the results by applying appropriate interpolation methods. The aim of the research is to analyse the quality of the DTM model and to consider suitability of certain interpolation methods, based on the obtained results, i.e. their advantages and disadvantages. The experiment was done in the software environment ERDAS IMAGINE 2014.Rad opisuje postupak izrade digitalnih modela terena (DMT) primjenom različitih metoda interpolacije. Pritom se analiziraju prikaz i točnost DMT-a, dobiveni s topografskih karata različitih mjerila te primjenom različitih metoda interpolacije. Kvaliteta i točnost DMT-a ovise o složenosti reljefa, izvoru podataka, ali i o metodi interpolacije visina. Osnovna ideja u radu je kreiranje DMT-a za izabrano područje te primjenom odgovarajućih metoda interpolacije usporediti dobivene rezultate. Cilj istraživanja je analizirati kvalitetu DMT-a te na temelju dobivenih rezultata razmotriti pogodnost pojedinih metoda interpolacije, odnosno njihove prednosti i mane. Istraživanje je realizirano u softverskom okruženju ERDAS IMAGINE 2014

    Analiza prikaza digitalnih modela terena primjenom različitih metoda interpolacije

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    In the paper is described the process of creating digital terrain models (DTM) using different interpolation methods. The analyses show the accuracy of the DTM obtained from topographic maps at different scales and using different interpolation methods. The quality and accuracy of DTM depends on the complexity of the terrain, data sources, and methods of height interpolation. The basic idea is the creation of the DTM for the selected area and the comparison of the results by applying appropriate interpolation methods. The aim of the research is to analyse the quality of the DTM model and to consider suitability of certain interpolation methods, based on the obtained results, i.e. their advantages and disadvantages. The experiment was done in the software environment ERDAS IMAGINE 2014.Rad opisuje postupak izrade digitalnih modela terena (DMT) primjenom različitih metoda interpolacije. Pritom se analiziraju prikaz i točnost DMT-a, dobiveni s topografskih karata različitih mjerila te primjenom različitih metoda interpolacije. Kvaliteta i točnost DMT-a ovise o složenosti reljefa, izvoru podataka, ali i o metodi interpolacije visina. Osnovna ideja u radu je kreiranje DMT-a za izabrano područje te primjenom odgovarajućih metoda interpolacije usporediti dobivene rezultate. Cilj istraživanja je analizirati kvalitetu DMT-a te na temelju dobivenih rezultata razmotriti pogodnost pojedinih metoda interpolacije, odnosno njihove prednosti i mane. Istraživanje je realizirano u softverskom okruženju ERDAS IMAGINE 2014

    An Automated Process of Creating 3D City Model for Monitoring Urban Infrastructures

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    This paper describes the process of designing models and tools for an automated way of creating 3D city model based on a raw point cloud.Also, making and forming 3D models of buildings. Models and tools for creating tools made in the model builder application within the ArcGIS Pro software. An unclassified point cloud obtained by the LiDAR system was used for the model input data. The point cloud, collected by the airborne laser scanning system (ALS), is classified into several classes: ground, high and low noise, and buildings. Based on the created DEMs, points classified as buildings and formed prints of buildings, realistic 3D city models were created. Created 3D models of cities can be used as a basis for monitoring the infrastructure of settlements and other analyzes that are important for further development and architecture of cities

    On trend analysis in climatic time series, with application to surface temperature

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    The deletion of a trend as an initial step in the analysis of climatic time series may result in the elimination of low-frequency components which constitute an integral part of climatic variability. An example is given here showing that linear trend deletion from the time series of the World Ocean annual sea-surface temperature (1850–2009) reduces the low-frequency (from 0.02 year–1 to 0.001 year–1) part of the time series spectrum by ∼40% to 80% thus severely distorting the spectrum of climate. As an additional result, it is shown that the current warming can be explained in full within the framework of a stationary stochastic model fitted directly to the time series of annual sea-surface temperature (SST) from 1850 through 2009 with no trend deletion. According to the model, the recurrence time of runs of generally increasing temperature by ∼0.5°C lasting for several decades (as has been observed since about 1956) is about 500 years for the World Ocean. Thus, the current run of growing SST is not an extremely rare event in climate and can be explained as a part of the natural climatic variability. These results show that deleting linear trends requires a thorough preliminary analysis. It is suggested that the approach described here can be used to improve physical models of the World Ocean climate

    The ‘PAMIR XXI’ Project of a Complex Setup for the PCR Study in a Wide Energy Range 1014– 1018eV

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    A new comprehensive EAS experiment for multi-component study of the energy spectrum behavior and composition of the PCR in a wide energy range 1014 – 1018 eV is launched at the Pamirs this year. The experimental setup of ~ 1 km2 in area combines conventional EAS array technique with those of X-Ray emulsion chamber, Cherenkov detector array and Cherenkov atmospheric imaging telescopes (IACT). The goals of the experiment and the experimental techniques are discussed

    Weak ferromagnetism and short range polar order in NaMnF 3 thin films

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    The orthorhombically distorted perovskite NaMnF3 has been predicted to become ferroelectric if an a = c distortion of the bulk Pnma structure is imposed. In order to test this prediction, NaMnF3 thin films were grown on SrTiO3 (001) single crystal substrates via molecular beam epitaxy. The best films were smooth and single phase with four different twin domains. In-plane magnetization measurements revealed the presence of antiferromagnetic ordering with weak ferromagnetism below the Néel temperature TN = 66 K. For the dielectric studies, NaMnF3 films were grown on a 30 nm SrRuO3 (001) layer used as a bottom electrode grown via pulsed laser deposition. The complex permittivity as a function of frequency indicated a strong Debye-like relaxation contribution characterized by a distribution of relaxation times. A power-law divergence of the characteristic relaxation time revealed an order-disorder phase transition at 8 K. The slow relaxation dynamics indicated the formation of super-dipoles (superparaelectric moments) that extend over several unit cells, similar to polar nanoregions of relaxor ferroelectrics

    Analysis of the capacity changes in the 'Garajevac-Istok' excavation by applying the GIS technology

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    The paper discusses the concept of construction and monitoring of capacity changes - the volume of the "Garajevac-Istok" excavation (mine), located in the cadastral municipality of Novi Bečej. Namely, in the earlier period, the physical surface of the Earth and geospace in general were shown two-dimensionally (2D), in a plane, by some of the cartographic methods (contour lines, points heights, hypsometry) or three-dimensionally (3D), by modeling of reliefs and relief cards. The cartographic principles of terrain making and visualizing on relief mapping models allow the creation of 3D views, but not enough quality and engineering precise 3D terrain models. In addition, there is a possibility of quantitative and qualitative assessment of the terrain on the mentioned models not to be accurate enough. With new technologies, the 3D geospatial display mode changes, and the concept of digital terrain modeling (DTM) is being applied. The main goal of the work is to create 3D models and to give an analysis of the "Garajevac-Istok" mine for a certain period of exploitationU radu se razmatra koncept izrade i praćenja promena kapaciteta - kubature kopa 'Garajevac - istok', koji se nalazi na katastarskoj opštini Novi Bečej. Ranije su se fizička površ Zemlje i geoprostor uopšte prikazivali dvodimenzionalno (2D) u ravni, nekom od kartografskih metoda (izolinije, kote, hipsoskala) ili trodimenzionalno (3D), izradom maketa i reljefnih karata. Kartografski principi izrade i vizualizacije terena na reljefnim kartografskim modelima omogućuju stvaranje 3D prikaza, ali ne i dovoljno kvalitetnog i inženjerski preciznog 3D modela terena. Pritom je mogućnost kvantitativne i kvalitativne ocene terena na pomenutim modelima otežan i nije dovoljno tačan. Sa pojavom novih tehnologija menja se način 3D prikaza geoprostora, odnosno primenjuje se koncept izrade digitalnih modela terena (DMT). Osnovni cilj rada jeste kreiranje 3D modela i uporedna analiza kubature kopa 'Garajevac - istok' za određeni period eksploatacije
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