To the Editor: A recent article in PNAS by Asikainen and Werle (1) reports on the occurrence and morphology of ferromanganese nodules found in a New Hampshire lake. The authors offer data on the shapes, banding, composition, and distribution of the nodules and crusts. They also state that my paper (2) claims that the morphology of such nodules is controlled by elemental concentrations and that ...

babbitt is a white silvery alloy that composed of tin, lead, copper and antimony. this alloy is the most current bearing alloy in industrial applications. the characteristics of this alloy, such as high wearing resistance and low coefficient of friction, have converted it into a bearing cover. the target of this study is investigation on the effects of alloy elements on wearing and micro-struct...

Model transformations are one of the core artifacts of a model-driven engineering approach. The relational logic language Alloy has been used in the past to verify properties of model transformations. In this paper we introduce the concept of functional Alloy modules. In essence a functional Alloy module can be viewed as an Alloy module representing a model transformation. We describe a sublang...

The mechanical properties of the Akers type clasp, bar and frame made by the newly developed Ti-20Cr-0.2Si alloy were studied in order to obtain the indices for designing the cast partial denture base. In the case of the clasp, the bending strength of the Ti-20Cr-0.2Si alloy and pure Ti was lower than that of the Co-Cr alloy. The Ti-20Cr-0.2Si alloy and pure Ti may have the same retentive force...

in this paper, a novel method of producing bi-metallic alloy nanoparticles at low temperatures using hydrogen bombardment of thin films, deposited on glass substrates, is introduced. optical and morphological characteristics of the nanoparticles were extensively studied for various conditions of plasma treatment, such as plasma power density, temperature, duration of hydrogen bombardment, thick...

the openings of copper converter in sarcheshmeh copper complex in iranis made of a heat resisting austenitic steel (fe-25cr-12ni) and many failures have been reported. understanding the failure mechanism of the alloy helps to develop better alloys for similar complex environments. samples of as-cast alloy and those taken from failed ones were examined. optical microscopy (om), x-ray diffraction...

objectives: micromechanical retention of resin cements to alloys is an important factor affecting the longevity of metal base restorations. this study aimed to compare the bond strength and etching pattern of a newly introduced experimental etchant gel namely nano met etch with those of conventional surface treatment techniques for nickel-chrome (ni-cr) and high noble alloys.  materials and met...

(HIPing), can improve the tribo-mechanical properties of cobalt-based alloys. The alloy selected for this investigation had a nominal wt.% composition of Co-30Cr-14W-1C, which is similar to the composition of the commercially available Stellite®4 alloy. The Hot Isostatic Pressed (HIPed) alloy had a much finer microstructure than the cast alloy, which showed a typical hypoeutectic dendritic micr...

Objectives: This study is undertaken to evaluate the dependence of bond strength of 100% fresh nonprecious alloy and the combination of 50% recast (used) alloy and 50% fresh alloy with three different veneering ceramic material. Materials and methods: To evaluate the shear bond strength between new and recast alloy nonprecious Ni-Cr alloy (System KN®, Adentatec, Germany) was used with three dif...

PURPOSE The aim of this study was to evaluate the effect of metal primers on the bonding of dental alloys and veneer resin. Polyvinylpyrrolidone solution's tarnish effect on bonding strength was also investigated. MATERIALS AND METHODS Disk-shape metal specimens (diameter 8 mm, thickness 1.5 mm) were made from 3 kinds of alloy (Co-Cr, Ti and Au-Ag-Pd alloy) and divided into 4 groups per each ...