Search results for "layer"
showing 10 items of 2667 documents
Morphological determination of the phototrophic community composition of biological soil crusts in coastal sand dunes in northern Germany
2022
This dataset comprises the microbial community composition of biological soil crusts in north-German sand dunes. For this we obtained enrichment cultures of phototrophic microorganisms, by placing fragments of biocrusts of the same Petri dishes as used for sequencing, in Petri dishes with Bold Basal (1N BBM) agarized medium (Bischoff and Bold 1963). Cultures were grown under standard laboratory conditions: with a 12-hour alteration of light and dark phases and irradiation of 25 μmol photons m-2 s-1 at a temperature 20 ± 5 ºС. Microscopic study of these raw cultures began in the third week of cultivation. Morphological examinations were performed using Olympus BX53 light microscope with Noma…
Spatial Reconstruction Algorithm of DT Layer in Cryogenic Targets Using Optical Techniques
2007
The measurements of the solid DT layer, in terms of thickness and roughness, in the LMJ geometry (i.e. in a hohlraum) are not trivial. The DT layer measurements will be done using a Matsukov-Cassegrain telescope placed 39 cm away from the target. This telescope will be used to acquire shadowgraphy images on equators, and interferometric measurements on pole areas using optical coherence tomography (OCT). Optical coherence tomography allows determining the DT layer thickness on a few points, in the polar regions of the target. By scanning around the poles, several points can be acquired in order to calculate the roughness and the local shape of the DT layer at the pole. Both techniques were …
Anodic layers formed on steel in phosphate buffer solution
1986
In-situ gamma scattering and ex-situ conversion electron Mossbauer, and Auger spectroscopy were applied to investigate anodic layers on steel. Samples treated in the active potential range in phosphate buffer solution show a Fe(II)-phosphate deposit on the surface. After treatment in the passive potential region, only Fe3+was found to exist in the oxide layer. The passive layer does not consist of stoichiometric oxidic phases.
Multilayered samples reconstructed by measuring Kα/Kβ or Lα/Lβ X-ray intensity ratios by EDXRF
2013
Abstract In this paper a general method based on energy-dispersive X-ray fluorescence (EDXRF) analysis has been tested to assess its possible use as a tool to reconstruct the structure and determine the thickness of two and/or multi-layered materials. The method utilizes the X-ray intensity ratios of Kα/Kβ or Lα/Lβ peaks (or the ratio of these peaks) for selected elements present in multi-layered objects of various materials (Au alloys, gilded Cu, gilded Ag, gilded Pb, Ag–Au Tumbaga, stone surfaces with protective treatments, Zn or Nickel plating on metals). Results show that, in the case of multi-layered samples, a correct calculation of the peak ratio (Kα /Kβ and/or Lα/Lβ) of relevant ele…
Formation of cobalt silicide films by ion beam deposition
2006
Abstract Thin films of cobalt silicide are widely used as metallization in very large-scale integrated electronic circuits. In this study, Co ions were deposited on Si(1 1 1) wafers by a high beam current filter metal vacuum arc deposition (FMEVAD) system. Surface silicide films were formed after annealing from 500 to 700 °C for 30 min. The results show that a thin CoSi2 surface layer with both a smooth surface topography and sharp interface can be achieved by annealing at 700 °C. The CoSi phase and O contamination were observed in the samples that were annealed at lower temperatures.
Thin film growth into the ion track structures in polyimide by atomic layer deposition
2017
Abstract High-aspect ratio porous structures with controllable pore diameters and without a stiff substrate can be fabricated using the ion track technique. Atomic layer deposition is an ideal technique for depositing thin films and functional surfaces on complicated 3D structures due to the high conformality of the films. In this work, we studied Al2O3 and TiO2 films grown by ALD on pristine polyimide (Kapton HN) membranes as well as polyimide membranes etched in sodium hypochlorite (NaOCl) and boric acid (BO3) solution by means of RBS, PIXE, SEM-EDX and helium ion microcopy (HIM). The focus was on the first ALD growth cycles. The areal density of Al2O3 film in the 400 cycle sample was det…
Growth of osteoblasts on lithographically modified surfaces
2007
Here we report about preliminary investigations on developing substrates for culturing osteoblasts, the cells responsible for production of mineralised bone, by lithographically modifying the surfaces of several materials. The proton beam writing system at the National University of Singapore was used to fabricate high aspect ratio structures in PMMA, while two-dimensional low aspect ratio structures were fabricated using conventional electron beam lithography (EBL) and UV lithography (UVL) in SU-8. It was found that oxygen plasma treatment of structured SU-8 surfaces changed the surface layer and significantly improved cell attachment and proliferation. Cells grown on patterned thick PMMA …
Characterization of ALD grown Ti x Al y N and Ti x Al y C thin films
2017
Abstract Atomic layer deposition (ALD) was used to grow Ti x Al y N and Ti x Al y C thin films using trimethylaluminum (TMA), titanium tetrachloride and ammonia as precursors. Deposition temperature was varied between 325 °C and 500 °C. Films were also annealed in vacuum and N 2 -atmosphere at 600–1000 °C. Wide range of characterization methods was used including time-of-flight elastic recoil detection analysis (ToF-ERDA), X-ray diffractometry (XRD), X-ray reflectometry (XRR), Raman spectroscopy, ellipsometry, helium ion microscopy (HIM), atomic force microscopy (AFM) and 4-point probe measurement for resistivity. Deposited films were roughly 100 nm thick and contained mainly desired elemen…
Niobium implantation effects in BaTiO3 and SrTiO3
1992
Abstract Single crystals of BaTiO3 and SrTiO3 have been implanted at room temperature with 150 keV Nb+ ions to doses ranging from 1014 to 1017 ions cm2. The structure and the oxidation state of the damaged layer have been investigated by Rutherford backscattering-ion channeling and electron spectroscopy, respectively. SrTiO3 is rendered amorphous at relatively low doses of 2 × 1015 ions cm−2, but the damage is efficiently annealed at 450°C for 1 2 h. For both materials, the oxidation state of niobium varies from + 5 to + 2 along the depth. Moreover, a considerable chemical shift (2.3 eV) is observed for barium in BaTiO3.
The passivation of steel in sodium sulphate solution studied by CEMS and aes
1990
The passive layer formed on standard steel by anodic oxidation in 0.5 M sodium sulphate solution was found to contain iron only in the trivalent state. The thickness of the layer increases with the applied potential as well as with the time the passivating potential is applied to the sample. These results, compared with the electrochemical data, lead to the suggestion that the passive behaviour is not due to the whole oxidic layer but due to a thin, low lying interfacial layer with a structural disorder.