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...

The three major distress conditions affecting the performance of asphalt pavements are permanent deformation or rutting, fatigue or load associated cracking, and low temperature or thermal cracking. In an earlier technical topics article (Fall, 1998), we examined the causes of fatigue cracking and the importance of good compaction during construction to help minimize this type of distress. In t...

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...

One of the limiting factors in large-scale cryopreservation is the formation of fractures. The prevalence of cracking in cryopreserved bulky tissues is frequently associated with temperature gradients, which lead to non-uniform thermal contraction of the tissue. With new cryoprotectants available, it may be possible to reduce temperature gradients to much lower levels, in which case other contr...

Most studies neglect the presence of thermal cracking reactions in industrial FCC process. Nevertheless, the present work proposes a new model which modified the 10-lumps kinetic model given by Jacob el al. (1976), through to inclusion a new lump named dry gas represent the results of the thermal reactions. Similarly as in the 10-lumps kinetic model, the proposed 11-lumps kinetic model consider...

Given that concrete masonry walls are expected to experience shrinkage combined with thermal expansion and contraction, and in some cases even carbonation, throughout their service life, cracking is to be expected. However, after concrete masonry walls have been placed into service, originally anticipated and accounted for cracking is often misdiagnosed as a structural defect. Such misdiagnoses...

In thermal cracking plants, it is desired to apply an optimal temperature profile along the reactor to minimize the operation cost. In this article a simulator is developed by the use of a mathematical model, which describes the static operation of a naphtha thermal cracking pilot plant. The model is used to predict the steady state profiles of the gas temperature and product yields. Using ...

The thermal expansivity of oceanic lithosphere is a key mineral physics parameter that controls the rate of seafloor subsidence. Because of strongly temperature-dependent mantle rheology, effective expansivity for lithosphere as a whole could be substantially lower than indicated by mineral physics data. Viscoelastic modeling indicates that this reduction in expansivity could be as high as ∼15–...

Plates of 3–5 mm in thickness were extracted from an AZ91D ingot and then butt joints of the plates were produced using tungsten inert gas (TIG) welding method. The TIG arc was also used to deposit welding beads on some of the thin plates. No cracking was found in the butt joints. However, hot cracking was always observed to propagate from the heat affected zone (HAZ) under the welding bead int...