The aim of this paper is the steady state and dynamic simulations of the ammonia unit of Shiraz petrochemical complex and system behavior study versus the feed flow rate change for producing a good quality product. The ammonia unit consists of the reformer units, shift converter units, carbon dioxide absorption unit, methanation unit, and ammonia synthesis unit. For this purpose, in the first s...

Dynamic architectural change is defined as the addition and removal of components and connectors. Dynamic software architectures are those architectures that modify their architecture and enact the modifications during the system’s execution. This behavior is most commonly known as run-time evolution or dynamism. As dynamic software architecture use becomes more widespread, it is important to g...

urban settlements and their connectivity will be the dominant driver of global change during the twenty-first century. in an attempt to assess the effects of urban growth on available land for other uses and its associated impacts on environmental parameters, we modeled the change in the extent of gorgan city, the capital of the golestan province of iran. we used landsat tm and etm+ imagery of ...

In this paper, the effect of the crack on dynamic behavior of cracked micro-beam in the presence of DC and AC loads are investigated. By applying the residual axial stress and fringing field stress, a nonlinear analytical model of cracked micro-beam is presented and crack is modeled by a massless rotational spring. The governing equation of the system is solved using Galerkin procedure and shoo...

In this paper, for the first time, the subject of change point estimation has been utilized in the stationary state of auto regressive moving average (ARMA) (1, 1). In the monitoring phase, in case the features of the question pursue a time series, i.e., ARMA(1,1), on the basis of the maximum likelihood technique, an approach will be developed for the estimation of the stationary state’s change...

Introduction: High precision Digital Terrain Models (DTMs) made from High Resolution Imaging Science Experiment (HiRISE) [1] stereo pairs are being produced for geomorphic and geologic analyses (e.g. [2, 3, 4]) as well as landing site assessment [5, 6, 7]. In many cases, they are being used to orthorectify sequences of images, making change detection of the martian surface possible at unprecede...

hydroponic experiments were performed to exam the dynamic change of endogenous proline in rice seedlings exposed to potassium chromate chromium (vi) or chromium nitrate chromium (iii). although accumulation of both chromium species in rice seedlings was obvious, more chromium was detected in plant tissues of rice seedlings exposed to chromium (iii) than those in chromium (vi), majority being in...

The dynamic features of programming languages are useful constructs that bring developers convenience and flexibility, but they are also perceived to lead to difficulties in software maintenance. Figuring out whether the use of dynamic features affects maintenance is significant for both researchers and practitioners, yet little work has been done to investigate it. In this paper, we conduct an...

being very dynamic, natural and artificial land features are changing somewhat rapidly in over lifetime. it is important that such changes be inventoried accurately so that the physical and human processes at work can be more fully understood. change detection is a technique used in remote sensing to determine the changes in a particular object of study between two or more time periods. this re...