INTRODUCTION The shear bond strength of orthodontic brackets bonded to micro-hybrid and micro-particulate resins under different surface treatment methods was assessed. METHODS Two hundred and eighty test samples were divided into 28 groups (n = 10), where 140 specimens were filled with Durafill micro-particulate resin and 140 with Charisma composite. In 140 samples, a coupling agent (silane)...

Coal roadway driving is an important part of the underground mining system, and very common in Chinese coal mines. However, the high concentration of respirable dust produced in the blasting operation poses a great hazard to miners’ health as well as the underground environment. In this paper, based on the direct simulation Monte Carlo method, the gas–solid two-phase flow model of particle move...

Specimens (such as metal inlays) with 30 degrees or 45 degrees marginal bevel were prepared by casting with a 12% Au-Pd-Ag alloy or a gold alloy. A form of the marginal bevel was traced on a profile projector before and after sandblasting, and the length of the abraded margin measured. All the blasting conditions abraded the marginal bevel, while the blasting at 20 mm for 2 seconds brought abou...

Evaluation of blasting-induced rock damage and fragmentation is very important for safety control construction in the jointed mass. The discontinuous numerical models are commonly applied due to advantages modeling treating discontinuities. In this paper, fracturing algorithm rate dependent strength law incorporated into deformation analysis (DDA) study wave propagation phenomena dynamic proble...

Interactive theorem proving requires a lot of human guidance. Proving a property involves (1) figuring out why it holds, then (2) coaxing the theorem prover into believing it. Both steps can take a long time. We explain how to use GL, a framework for proving finite ACL2 theorems with BDDor SAT-based reasoning. This approach makes it unnecessary to deeply understand why a property is true, and a...

Computer programs can only run reliably if the underlying operating system is free of errors. In this paper we evaluate, from a practitioner’s point of view, the utility of the popular software model checker Blast for revealing errors in Linux kernel code. The emphasis is on important errors related to memory safety in and locking behaviour of device drivers. Our conducted case studies show tha...

Reasoning with bit-vectors arises in a variety of applications in verification and cryptography. Michel and Van Hentenryck have proposed an interesting approach to bit-vector constraint propagation on the word level. Each of the operations except comparison are constant time, assuming the bit-vector fits in a machine word. In contrast, bitvector SMT solvers usually solve bit-vector problems by ...

nitrogen oxides and carbon monoxide gases together with dust are known as the major pollutants arising during the blasting operations using the ammonium nitrate-fuel oil (anfo) explosive at the sungun surface mine, located in the northwest of iran. the pollutants were monitored during some blasting operations at the mine. it was concluded that the gases and dust clouds initially went up to the ...

Rock blasting with explosives is the first stage of rock fragmentation and plays a key role in results mining chain. Fragmentation optimization achieved by considering energy efficiency explosive, optimal distribution explosive rocky mass, programmed controlled release during blasting. The quality usually performed using tools that estimate sizes fragments via analysis two- or three-dimensional...

Blasting complaints are consuming an increasing amount of time and resources. This worsening situation has spawned new methods for relaying the public’s concerns. The direct measurement of crack response to both long term environmental and blast vibration effects with the same sensor exemplifies one new approach, which can be helpful in the process of educating quarry neighbors about the large ...