OBJECTIVE To compare the deflection load characteristics of homogeneous and heterogeneous joints made by laser welding using various types of orthodontic wires. MATERIALS AND METHODS Four kinds of straight orthodontic rectangular wires (0.017 inch × 0.025 inch) were used: stainless-steel (SS), cobalt-chromium-nickel (Co-Cr-Ni), beta-titanium alloy (β-Ti), and nickel-titanium (Ni-Ti). Homogene...

The aim of this study is to evaluate the microstructures, tensile lap shear strength, and fatigue resistance of 6022-T43 aluminum alloy joints welded via a solid-state welding technique-ultrasonic spot welding (USW)-at different energy levels. An ultra-fine necklace-like equiaxed grain structure is observed along the weld line due to the occurrence of dynamic crystallization, with smaller grain...

Experiments were conducted to study the performance of circular and square tank surface aerators on the oxygen transfer coefficient and to a limited extent on power requirements. All the tanks are geometrically similar except for their shapes. They consist of a rotor of diameter, D, fixed with six flat blades rotating with a speed, N, in pure waters of viscosity, υ, at room temperature. A simul...

The objective of this study was to investigate the effects of cryo-treatment on the microstructure, corrosion behavior, and mechanical properties of Ti before and after laser welding. The microstructure was studied by optical microscopy. It was found that the grain size for Ti became smaller after cryo-treatment. Cryo-treatment could also refine and stabilize the crystal lattice structure and d...

aim and background: insecure attachment style is one of the important effective factors in many mental disorders. the aim of this study was to compare the positive, negative and disorganized schizotypal characteristics in secure, avoidance and anxiety attachment patterns among students of tabriz university, iran. methods and materials: in this cross-sectional descriptive study 300 students (150...

We define an invariant of welded virtual knots from each finite crossed module by considering crossed module invariants of ribbon knotted surfaces which are naturally associated with them. We elucidate that the invariants obtained are non-trivial by calculating explicit examples. We define welded virtual graphs and consider invariants of them defined in a similar way. 2000 Mathematics Subject C...

Construction and assembling process of shell structures has caused main problems. In these structures, there is no possibility for the integrated construction due to their large shell extent and they are built using a number of welded curved panel parts; hence, some geometrical imperfections emerge. Most of these imperfections are caused by the process of welding, transportation, inappropriate ...

Research Objectives: This project seeks to improve the basic understanding of colloid and colloid-facilitated transport of Cs in the vadose zone. The specific objectives are: • Determine the structure, composition, and surface charge characteristics of colloidal particles formed under conditions similar to those occurring during leakage of waste typical of Hanford tank supernatants into soils a...

be from pipe and connection breaks rather than structural failure of distribution reservoirs (as long as the reservoirs have been designed for lateral loading). Most of the examples of storage tanks and distribution reservoirs impacted by the 1994 Northridge and 1995 Hyogo-ken Nanbu earthquakes appear to have been of steel construction rather than of reinforced concrete or prestressed concrete ...