thermal cracking of a heavy liquid hydrocarbon was performed in a laboratory scale tubular reactor. central composite design (ccd), was used as an experimental design method. the design variables were coil outlet temperature (cot), feed flow and rate steam ratio. maximum yield of ethylene was 30.37 wt% at cot, residence time and steam ratio of 869oc, 0.208 s and 1.22 g/g, respectively. maximum ...

an experimental program was conducted to determine the effects of geosynthetic reinforcement on mitigating reflection cracking in asphalt overlays. the objectives of this study were to asses the effects of geosynthetics inclusion and its placement location on the accumulation of permanent deformation. to simulate an asphalt pavement overlaid on top of a crack in a concrete or asphalt pavement, ...

Abstract — The Ethylene production process is one of the most important aspects of a petrochemical plant. The bulk of the worldwide annual commercial production of Ethylene is based on thermal cracking of petroleum hydrocarbons with steam. This process is commonly called Steam cracking process. This article deals with Amir Kabir Petrochemical Olefin Furnaces that are located in special region o...

A condition-based maintenance optimization approach is developed for the road-cracking problem in order to derive optimal maintenance policies that minimize a total discounted maintenance cost. The approach is based on a Markov decision process that takes into account multiple actions with varying effects on future road performance. Maintaining the road consists of adding a new asphalt layer; h...

Passwords continue to be the primary means of authentication and security for online accounts and use in encrypting files and disks. The goal of this paper is to show how knowledge of personal information about a user can systematically be added to improve a password cracking task. In this paper we focus on the dictionary-based probabilistic context-free grammar (PCFG) approach to password crac...

Percussive tool use holds special interest for scientists concerned with human origins. We summarize the findings from two field sites, Taı̈ and Fazenda Boa Vista, where percussive tool use by chimpanzees and bearded capuchins, respectively, has been extensively investigated. We describe the ecological settings in which nut-cracking occurs and focus on four aspects of nut-cracking that have impo...

Samples of apricot pits at 7.61, 12.45, 18.21 and 25.15% (wet basis) moisture contents in the three directions (along length, width and thickness) were subjected to impact energy ranged from 0.2 to 1.1 J using an impact test apparatus. Data obtained on the quantity of fully cracked and unbroken kernel, fully cracked but broken kernel and uncracked pits were used in the computation of the pits c...

In conventional WLCSP process, after defining the under bump metal (UBM) layer, a solder ball is dropped in the UBM opening. A subsequent thermal reflow cycle melts the solder ball and cools it in a well defined shape on top of the UBM layer. One draw back of this technology is the fracture or cracking of passivation film that may occur during the solder ball reflow process. The cracks in the p...

Cracking of laser hybrid welding of eccentric fillet joints has been studied for stainless steel. Laser hybrid welding enables narrow deep welds with freedom for shaping the upper weld geometry. The significance of geometrical aspects like weld toe radius, weld surface topography and lack of fusion on fatigue cracking is discussed. Constant amplitude four point bending tests, S/N-curve, topogra...

The paper presents a new analytical model to study the evolution of radial cracking around a corroding steel reinforcement bar embedded in concrete. The concrete cover for the corroding rebar is modelled as a thick-walled cylinder subject to axisymmetrical displacement constraint at the internal boundary generated by expansive corrosion products. A bilinear softening curve reflecting realistic ...