Underground mining becomes more efficient due to the technological advancements of drilling and blasting methods and the developing of highly productive mining methods that facilitate easier access to ore. In the perspective of maximizing productivity in underground mining by drilling and blasting methods, overbreak control is an essential component. The causing factors of overbreak can simply ...

OBJECTIVES The effect of shot blasting treatment on the cyclic deformation and fracture behavior of a commercial pure titanium with two different microstructures; equiaxed (alpha-phase) and acicular (martensitic alpha'-phase) was investigated. METHODS Fatigue tests were carried out in artificial saliva at 37 degrees C. Cyclic deformation tests were carried out up to fracture and fatigue crack...

For microfabrications of biochips with micro fluidic channels, a large number of microfabrication techniques based on silicon or glass-based Micro-Electro-Mechanical System (MEMS) technologies were proposed in the last decade. In recent years, for low cost and mass production, polymer-based microfabrication techniques by microinjection molding and micro hot embossing have been proposed. These t...

Environmentally Safe and Effective Processes for Paint Removal Paint stripping and repainting of aircraft surfaces arc requircd periodically during thc operating lifetime of an aircraft. Historically, paint removal has been achieved using chemical strippers, involving materials which contain toxic components and which create hazardous working conditions. The process generates large amounts of h...

Dynamic slope stability in open-pit mines still remains a challenging task in the computational mining design. Earthquake and blasting are two significant sources of dynamic loads that can cause many damages to open-pit mines in active seismic areas and during exploitation cycles. In this work, the effects of earthquake and blasting on the stability of the NW slope of Chadormalu mine are compar...

Correct selection of coefficients for blasthole parameters in Ghalat limestone mine in Shahr-e-kord of Iran has resulted is designing and performing 20 blasting operations. After each blast, fragmented rocks larger than one square meter, called oversize, are estimated and prepared for secondary blasting. Next blasthole pattern were designed based on previous blasting results. The results of the...

OBJECTIVES This study compared the effect of hexamethyldisiloxane (HMDSO) and ammonia (NH3) plasmas on the bond strength of resin cement to fiber posts with conventional treatments. MATERIALS AND METHODS Sixty-five fiber posts were divided into 5 groups: Control (no surface treatment); H2O2 (24% hydrogen peroxide for 1 min); Blasting (blasting with aluminum oxide for 30 sec); NH3 (NH3 plasma ...

Dry-ice particle blasting is similar to sand blasting, plastic bead blasting, or soda blasting where a media is accelerated in a pressurized air stream (or other inert gas) to impact the surface to be cleaned or prepared. With dry-ice blasting, the media that impacts the surface is solid carbon dioxide (CO2) particles. One unique aspect of using dry-ice particles as a blast media is that the pa...

This paper presents the field testing results of an autonomous manipulator-based robotic system that strips the paint and rust from steel bridges [Liu et al., 2008]. The key components of this system are sensing and planning, which have been presented in other research papers. The grit-blasting field trial presented in this paper spanned 6 weeks, and included 20 hours over 4.5 days of actual gr...

Rock fragmentation is one of the desired results of rock blasting. So, controlling and predicting it, has direct effects on operational costs of mining. There are different ways that could be used to predict the size distribution of fragmented rocks. Mathematical relations have been widely used in these predictions. From among three proposed mathematical relations, one was selected in this stud...