The Influence of Iron Content on the Porosity of AlSi9 Alloy Intended for Alfining Piston Ring Inserts.

Due to its tendency to increase the power of engines, improving their reliability and operational efficiency, the compression ring in combustion engine pistons is embedded in a cast iron insert, which is subjected to the process of "alfining". This involves covering the insert with an Al-Si alloy, which increases the iron content. Research has shown that the β-AlFeSi phases crystallizing in the area of the insert-piston connection are the main cause of an unstable connection between the silumin casting of the piston and the ring insert.

Influence of Surface Structure on Ball Properties during a Professional Water Polo Game.

The use of modern materials in sports, in terms of chemical composition and surface texture, entails both progress in results and an increasing discrepancy in the technical parameters of the equipment used. This paper aims to demonstrate the differences between balls admitted to a league and world championships in composition, surface texture, and the influence of these parameters on the water polo game. This research compared two new balls produced by top companies producing sports accessories (Kap 7 and Mikasa).

Production of Electrolytic Composite Powder by Nickel Plating of Shredded Polyurethane Foam.

Ni-poly(DPU) composite powder was produced under galvanostatic conditions from a nickel bath with the addition of pulverized polymer obtained during the shredding of polyurethane foam (poly(DPU)). The Ni-poly(DPU) composite powder was characterized by the presence of polymer particles covered with an electrolytical amorphous-nanocrystalline nickel coating. The phase structure, chemical composition, morphology, and the distribution of elements was investigated.

Polyurethane-Based Porous Carbons Suitable for Medical Application.

The main aim of the study was to synthesize and analyze spectral data to determine the structure and stereometry of the carbon-based porous material internal structure. Samples of a porous biomaterial were synthesized through anionic polymerization following our own patent and then carbonized. The samples were investigated using MALDI ToF MS, FTIR ATR spectroscopy, optic microscopy, SEM, confocal laser scanning microscopy and CMT imaging.

Ceramic Biomaterial Pores Stereology Analysis by the Use of Microtomography.

The main aim of this study was to analyze microtomographic data to determine the geometric dimensions of a ceramic porous material's internal structure. Samples of a porous corundum biomaterial were the research material. The samples were prepared by chemical foaming and were measured using an X-ray scanner.

Effect of Autoclaving Time on Corrosion Resistance of Sandblasted Ti G4 in Artificial Saliva.

Titanium Grade 4 (Ti G4) is the most commonly used material for dental implants due to its excellent mechanical properties, chemical stability and biocompatibility. A thin, self-passive oxide layer with protective properties to corrosion is formed on its surface. However, the spontaneous TiO layer is chemically unstable.

Electrophoretic deposition of chitosan coatings on the Ti15Mo biomedical alloy from a citric acid solution.

Chitosan biocoatings were successfully deposited on the Ti15Mo alloy surface cataphoretic deposition from a solution of 1 g dm of chitosan in 4% (aq) citric acid. The influence of the cataphoretic deposition parameters on quality and morphology of the obtained coatings were investigated using fluorescence and scanning electron microscopy. The functional groups' presence in chitosan chine were confirmed by ATR-FTIR methods.

Evaluation of Topographical Co-Cr-Mo Alloy Surface Changes After Various Finishing Treatments.

Purpose: To quantify the influence of three different finishing treatments on the cobalt-chromium-molybdenum (Co-Cr-Mo) alloy surface based on stereometric analysis parameters.

Materials And Methods: Eighteen specimens were casted from an extra-hard alloy (Wironit, BEGO, Bremen, Germany). The samples were distributed into three groups (n = 6 samples per group) dependent on different polishing techniques applied, as follows: A group, only electropolished (EP) samples; B group, after EP, an additional mechanical polishing process was applied to the surface by rubber discs and a polishing paste (RP); C group, after EP, an additional mechanical polishing process was completed by rubber discs, polishing paste and finally by a rotating deer leather wheel (RPDL).

Characterization of spatial patterns of dental restorative nanocomposites.

The aim of this study was to provide important insights into the effects of four different dental polishing protocols (one single-step and one multi-step either followed or not by diamond paste polishing) on the 3D surface morphology of two representative dental resin-based nanocomposites (a nanofilled and a nanohybrid composite) by means of digital image analysis and processing techniques. The 3D surface morphology was investigated by atomic force microscopy. Segmentation, statistics of height distributions (described by statistical parameters, according to ISO 25178-2: 2012) and Minkowski functionals were applied to the images to characterize the spatial patterns of analyzed samples at micrometer scale.

The effects of deposition time on the nanoscale patterns of Ag/DLC nanocomposite synthesized by RF-PECVD.

Introduction: In this study, a stereometric analysis of the three dimensional (3-D) surfaces of the Ag/DLC nanocomposite synthesized by RF-PECVD was performed.

Materials And Methods: Atomic force microscopy in noncontact mode was used to study surface morphology in correlation with multi-parametric statistical analysis. The associated parameters of segmented motifs in conformity with ISO 25178-2:, 2012 have been extracted using MountainsMap® Premium software.

Modelling the degree of porosity of the ceramic surface intended for implants.

The main goal of the study was to develop a model of the degree of surface porosity of a biomaterial intended for implants. The model was implemented using MATLAB. A computer simulation was carried out based on the developed model, which resulted in a two-dimensional image of the modelled surface.

Analysis of normal human retinal vascular network architecture using multifractal geometry.

Aim: To apply the multifractal analysis method as a quantitative approach to a comprehensive description of the microvascular network architecture of the normal human retina.

Methods: Fifty volunteers were enrolled in this study in the Ophthalmological Clinic of Cluj-Napoca, Romania, between January 2012 and January 2014. A set of 100 segmented and skeletonised human retinal images, corresponding to normal states of the retina were studied.

Morphological Properties of Siloxane-Hydrogel Contact Lens Surfaces.

Purpose: The aim of this study was to quantitatively characterize the micromorphology of contact lens (CL) surfaces using atomic force microscopy (AFM) and multifractal analysis.

Materials And Methods: AFM and multifractal analysis were used to characterize the topography of new and worn siloxane-hydrogel CLs made of Filcon V (I FDA group). CL surface roughness was studied by AFM in intermittent-contact mode, in air, on square areas of 25 and 100 μm, by using a Nanoscope V MultiMode (Bruker).

Assessment of possibilities of ceramic biomaterial fracture surface reconstruction using laser confocal microscopy and long working distance objective lenses.

A numerical description of fracture is an important step in the search of the correlation between specific micromechanisms of decohesion and material characteristics designated with the use of fracture mechanics methods. This issue is essential for the proper orientation of the search for basic relationships between chemical composition, technology, structure, and properties of materials. It often happens that fracture surfaces are well developed, which can significantly hinder or even prevent the measurement and reconstruction of the tested material surface geometry.

Morphology of Co-Cr-Mo dental alloy surfaces polished by three different mechanical procedures.

The present study aims at characterizing the three-dimensional (3-D) morphology of a Co-Cr-Mo dental alloy surface as a result of three different procedures used for polishing it. The sample surface morphology of the sampled surface was examined employing atomic force microscopy (AFM), statistical surface roughness parameters, and fractal analysis. An extra-hard dental alloy of cobalt-chromium-molybdenum (Co-Cr-Mo) (Wironit(®) , from BEGO, Bremen, Germany) was prepared and moulded.

Topographic Characterization of Cu-Ni NPs @ a-C:H Films by AFM and Multifractal Analysis.

In the present work three-dimensional (3-D) surface topography of Cu-Ni nanoparticles in hydrogenated amorphous carbon (Cu-Ni NPs @ a-C:H) with constant thickness of Cu and three thicknesses of Ni prepared by RF-Plasma Enhanced Chemical Vapor Deposition (RF-PECVD) system were investigated. The thin films of Cu-Ni NPs @ a-C:H with constant thickness of Cu and three thicknesses of Ni deposited by radio frequency (RF)-sputtering and RF-PECVD systems, were characterized. To determine the mass thickness and atomic structure of the films, the Rutherford backscattering spectroscopy (RBS) spectra was applied.

Fractal analysis of AFM images of the surface of Bowman's membrane of the human cornea.

The objective of this study is to further investigate the ultrastructural details of the surface of Bowman's membrane of the human cornea, using atomic force microscopy (AFM) images. One representative image acquired of Bowman's membrane of a human cornea was investigated. The three-dimensional (3-D) surface of the sample was imaged using AFM in contact mode, while the sample was completely submerged in optisol solution.