Influence of the continuous casting process of TIN-ZINC-LEAD bronze on the wear of the graphite crystallizer

The research conducted in this paper concerns the influence of the continuous casting process of tin-zinc-lead bronze on the wear of the graphite crystallizer. Observations and testing of the external surface of the cast rods indicate their good quality, without casting defects. No excessive surface degradation was observed on the inner surface of the crystallizers after casting. It was assessed that the surface quality of the crystallizer would be acceptable for further use, despite stuck residue, mainly in the crystallization zone

Influence of the continuous casting process of TIN-ZINC-LEAD bronze on the wear of the graphite crystallizer

The research conducted in this paper concerns the influence of the continuous casting process of tin-zinc-lead bronze on the wear of the graphite crystallizer. Observations and testing of the external surface of the cast rods indicate their good quality, without casting defects. No excessive surface degradation was observed on the inner surface of the crystallizers after casting. It was assessed that the surface quality of the crystallizer would be acceptable for further use, despite stuck residue, mainly in the crystallization zone

Microstructure and tribological properties of tin bronze-graphite composites made by stir casting

The paper presents results of the studies into production of copper-based composite materials for slide bearings. The studied materials covered tin bronze based composites with addition of lubricating phases in a form of graphite. The composite materials were prepared by melting and casting with simultaneous stirring. The titanium was introduced to the metal matrix in order to improve wettability of the graphite particles. The lowest average value of the coefficient of friction was reached with the CuSn10/graphite 45 μm composite which contained 0,4 % Ti. Low coefficients of friction and wear of the friction pair were also reached with other examined composites in CuSn10 matrix

Novel mechanism of photoinduced reversible phase transitions in molecule-based magnets

A novel microscopic mechanism of bi-directional structural changes is proposed for the photo-induced magnetic phase transition in Co-Fe Prussian blue analogues on the basis of ab initio quantum chemical cluster calculations. It is shown that the local potential energies of various spin states of Co are sensitive to the number of nearest neighbor Fe vacancies. As a result, the forward and backward structural changes are most readily initiated by excitation of different local regions by different photons. This mechanism suggests an effective strategy to realize photoinduced reversible phase transitions in a general system consisting of two local components.Comment: 4 pages, LaTex, 3 figures, to appear in Phys. Rev. Let

Communication methods and production techniques in fixed prosthesis fabrication: a UK based survey. Part 1: Communication methods

Statement of the problem The General Dental Council (GDC) states that members of the dental team have to 'communicate clearly and effectively with other team members and colleagues in the interest of patients'. A number of studies from different parts of the world have highlighted problems and confirmed the need for improved communication methods and production techniques between dentists and dental technicians.Aim The aim of this study was to identify the communication methods and production techniques used by dentists and dental technicians for the fabrication of fixed prostheses within the UK from the dental technicians' perspective. The current publication reports on the communication methods.Materials and methods Seven hundred and eighty-two online questionnaires were distributed to the Dental Laboratories Association membership and included a broad range of topics. Statistical analysis was undertaken to test the influence of various demographic variables.Results The number of completed responses totalled 248 (32% response rate). The laboratory prescription and the telephone were the main communication tools used. Statistical analysis of the results showed that a greater number of communication methods were used by large laboratories. Frequently missing items from the laboratory prescription were the shade and the date required. The majority of respondents (73%) stated that a single shade was selected in over half of cases. Sixty-eight percent replied that the dentist allowed sufficient laboratory time. Twenty-six percent of laboratories felt either rarely involved or not involved at all as part of the dental team.Conclusion This study suggests that there are continuing communication and teamwork issues between dentists and dental laboratories