The initiating explosive devices are prohibited in rock breaking near the goaf of the highly gassy mine. It is effective and applicable to cracking the hard roof with static cracking agent. By testing the static cracking of cubic limestone (size: 200 × 200 × 200 mm) with true triaxial rock mechanics testing machine under the effect of bidirectional stress and by monitoring the evolution process...

It is broadly accepted that so-called 'thermal' gas is the product of thermal cracking, 'primary' thermal gas from kerogen cracking, and 'secondary' thermal gas from oil cracking. Since thermal cracking of hydrocarbons does not generate products at equilibrium and thermal stress should not bring them to equilibrium over geologic time, we would not expect methane, ethane, and propane to be at eq...

Cracking is a major concern in welding aluminum alloys. Although weld solidification cracks can be eliminated through addition of filler alloy, the additives modify the alloy or base-metal constituents and may not always be desirable. High-energy beam processes, such as electron-beam welding, that result in minimal heat input reduce crack sensitivity, but their high cost limits their applicatio...

Crack surveys of bridge decks, performed over a 10-year period in northeast Kansas as part of three studies, provide strong guidance in identifying the parameters that control cracking in these structures. The surveys involve steel girder bridges—bridges that are generally agreed to exhibit the greatest amount of cracking in the concrete decks. The surveys include monolithic decks and decks wit...

Among the current IPPC installations, steam cracking for olefin production is the single most energy consuming process (ca. 30%) in the chemical industry, accounting for ca. 180 million tons of CO2 worldwide. This paper reviews steam cracking and innovative emerging olefin technologies in terms of energy efficiency. Pyrolysis section alone consumes ca. 65% of the total energy use and ca. 75% of...

In metastable austenitic stainless steels, strain-induced martensitic transformation during plastic deformation enhances work hardening of the material, increasing its strength and in some cases also ductility.1,2) The presence of α’-martensite, however, may increase the susceptibility of these materials to hydrogen embrittlement phenomena, for example delayed cracking.3–6) Delayed cracking can...

Introduction: The im port ance of secondary phas es in m art i an met eori t es li es in thei r pot ent i al to provi de cl ues about the mart i an envi ronm ent s res ponsi bl e for thei r form ati on. Duri ng this st udy, we anal yzed a num ber of car-bonat e-beari ng fract ure surfaces from the Nakhl a met eor-i t e. Here we des cri be the phys i cal and chemi cal propert i es of several man...

A computational study is performed to determine the contribution to ultrasound attenuation in carbon fiber reinforced polymer composite laminates of linear elastic scattering by matrix micro-cracking. Multiple scattering approximations are benchmarked against exact computational approaches. Results support linear scattering as the source of observed increased attenuation in the presence of micr...

The problem, generic objectness proposal, aims to reduce the candidate windows for object detection tasks. The popular evaluation criterion for related methods is detection-rate/windows-amount(DR-#WIN), where DR is the percentage of groundtruth objects covered by proposal windows. An object is considered “covered” by a window only if the strict PASCAL-overall criterion [3] is satisfied (the int...