Gheorghiu Irina-Maria, Mitran Loredana, Mitran M., Mironiuc-Cureu Magdalena, Iliescu A. A. and Suciu Ioana
Dental abfraction is a pathological process which causes a loss of dental hard substance. Etiopathogenesis is related to occlusal stress that causes microfractures in enamel and dentin in the cervical region. The restoration treatment is made using aesthetic adhesive materials, but must take into account the causal factors and the specific area where the restoration is done.
The paper presents the influence of coatings applied with the use of PVD method on cutting tools on the wear of the tool and compares it with an uncoated P25 cemented carbide plate. During the experiment, two types of TiAlN coatings were used, applied in various proportions, as well as TiN coating. During the tests, the average width of the wear band on the flank face in B VBBzone and the width of KBcrater were monitored. Moreover, the scanning analysis of the tool was conducted in order to determine the intensity of adhesive wear. The lowest values of selected tool wear indicators were found out with the use of TiAlN coating applied in eight layers in the proportions 33/67% -TiN/TiAlN. The scanning analysis proved the highest adhesive wear of the uncoated P25 cemented carbide plate, as well as increased abrasive wear of the flank face and the formation of a crater in comparison with coated plates.
The article presents essential elements reached during investigations of heat section of rotor blades which have been done in AFIT. The investigations were related to a valuation of helicopter’s rotor blades delamination. They used a method of thermal field measurement as well as a electricity capacitance between an airframe and a heat element of the installation. A suggestion of such measurements appeared during the disassembly of rotor blade heat sections when some local unglue of heat element’s tape from the structure of blade’s heating pack has seen. Spots nearby separation of adhesive are a potential area of a local temperature increase, both the electric heating element and the mechanical structure of the blade. This is especially dangerous for composite structures. Overheated composite structures characterized by reduced flexibility and becomes prone to cracking. Therefore, the possibility of non-invasive monitoring adhesive spots, without removing the blades would be particularly useful.
The selected techniques were reviewed and their technological aspects were characterized in the context of multi-phase flow for biogas production. The conditions of anaerobic fermentation for pig slurry in a mono-substrate reactor with skeleton bed were analysed. The required technical and technological criteria for producing raw biogas were indicated.
Design and construction of the mono-substrate model, biogas flow reactor, developed for cooperation with livestock buildings of various sizes and power from 2.5 kW to 40 kW. The installation has the form of a sealed fermentation tank filled with a skeletal deposit constituting a peculiar spatial system with regular shapes and a rough surface.
Incorporating a plant in such a production cycle that enables the entire slurry stream to be directed from the cowshed or pig house underrun channels to the reactor operating in the flow mode, where anaerobic digestion will take place, allows to obtain a biogas.
The paper presents preliminary results of experimental investigations in the field of hydrodynamic substrate mixing system for biogas flow assessment by the adhesive bed in the context of biogas production. The aim of the study was to assessment and shows the influence of the Reynolds number on the biogas resistance factor for the fermentation process in mono-substrate reactor with adhesive deposit. The measurement results indicate a clear effect of the Reynolds number in relation to the descending flow resistance coefficient for the adhesive bed.
Jolanta Świderska, Zbigniew Czech, Waldemar Świderski and Agnieszka Kowalczyk
1. Moszner, N. & Hirt, T. (2012). New Polymer-Chemical Developments in Clinical Dental Polymer Materials: Enamel- -Dentin Adhesives and Restorative Composites, J. Polym. Sci. Part A: Polym. Chem. 50, 4369-4402, DOI: 10.1002/pola.26260.
2. Feilzer, A.J. & De Gee, A.J. (1987). Setting stress in composite resin in relation to configuration of the restoration, J. Dent. Res. 66, 1636-1639.
3. Moszner, N. & Salz, U. (2007). Recent Developments of New Components for Dental Adhesives and Composites, Macromol
Katarzyna Wolska, Barbara Kot, Halina Mioduszewska, Cezary Sempruch, Lidia Borkowska and Katarzyna Rymuza
This study shows an association between the frequency of the nan1 gene (encoding neuraminidase) among 62 clinical Pseudomonas aeruginosa isolates and adhesion of these bacteria to human buccal epithelial cells. The 52 strains in which the gene was present (83.9%) were characterized by a higher adhesiveness (the mean number of adhering bacteria was 23.51 per cell) than strains in which the gene was not detected (16.23 per cell) and the difference was significant (P = 0.009, Mann-Whitney U test). Thus we found that the nan1 gene may play a role in the binding of clinical P. aeruginosa strains to buccal cells.
Janette Brezinová, Anna Guzanová, Dagmar Draganovská and Marián Egri
In this article, the attention is paid to the HVOF (High Velocity Oxygen Fuel) thermal spraying method by which the progressive coatings are applied on basic material C15E (STN 412020). These coatings are based on C-17CO, WC-CO-Cr and Cr3C2-25NiCr. There was made determination of the chemical composition of the coatings and assessment of coatings quality - adhesion, microhardness, porosity and wear resistance at room temperature (21°C) and also at operational elevated temperature (900°C). Results of adhesive wear showed high quality of all evaluated coatings and their suitability to extreme tribological conditions.
Accelerated corrosion testing is indispensable for material selection, quality control and both initial and residual life time prediction for bare and painted metallic, polymeric, adhesive and other materials in atmospheric exposure conditions. The best known Neutral Salt Spray (NSS) test provides unrealistic conditions and poor correlation to exposures in atmosphere. Modern cyclic accelerated corrosion tests include intermittent salt spray, wet and dry phases and eventually other technical phases. They are able to predict the material performance in service more correctly as documented on several examples. The use of NSS should thus be restricted for quality control.
Authors showed the influence of stabilization of the honeycomb core on shape of the composite sandwich test panel. Adhesive film laid on core ramps and cured with suitable cure cycle served as core stabilizer. Test panel geometry included different ramp angles (20° and 30°). To verify stabilization process a technology trial was performed. Three test panels were manufactured (3-stage, 1-stage and 1-stage with stabilized core). All test panels were manufactured in OoA process (Out of Autoclave). Panel surfaces were scanned with 3D scanner and compared with the reference CAD model. Both outer skin and inner skin were manufactured in Automated Fiber Placement Laboratory of Warsaw Institute of Aviation.
4. Desai, S.D., Patel, J.V., &Sinha V.K. (2003). Polyurethane adhesive system from biomaterial-based polyol for bonding wood. International Journal of Adhesion & Adhesives. 23, 393-399.
5. Jaganath, N. (2004). The Application of Reological Techniques in the Characterisation of Semisolids in the Pharmaceutical industry. Nelson Mandela Metropolitan University, Port Elizabeth.
6. García-Pacios, V., Costa, V., Colera, M., & Martín-Martínez, J.M. (2011). Waterborne polyurethane dispersions obtained with