International Journal of Industrial Engineering and Productional Research
Volume:19 Issue: 3, Sep 2008

Abstract: In recent years, many research works have been done to investigate the possibility of utilizing a broad range of materials as raw materials in the production of geopolymer cements. The use of artificial pozzolans or aluminosilicate-type industrial waste materials such as granulated blast-furnace slag and fly ash has been reported in many research works. Natural pozzolans are also aluminosilicate-type materials which can be activated with solutions of NaOH and Na2SiO3. Using a pumice-type natural pozzolan from Taftan Mountain located at the south east of Iran and different alkali-activators based on combinations of Na2SiO3 and NaOH, a number of natural-pozzolan-based geopolymer cement systems were designed and prepared. Final setting time, workability, and 28-day compressive strength of the systems were studied. The results obtained reveal that Taftan pozzolan can be activated using a proportioned mixture of Na2SiO3 and NaOH resulting in the formation of a geopolymer cement system exhibiting suitable workability and relatively high 28-day compressive strengths up to 63 MPa.

Abstract: In this study, we prepared a LaNi0.3Al0.7O3 perovskite catalyst using a sol-gel related method (with prop ionic acid as a solvent) for use in the methane dry reforming reaction to produce synthesis gas. We defined the catalyst structure on the basis of X-ray diffraction analysis and measurements of the specific surface area and particle size distribution. The mixed oxide structure was shaped into a cylindrical pellet before being measured for its mechanical strength. The shaped perovskite catalyst was then tested in the methane dry reforming reaction to produce synthesis gas at atmospheric pressure. The results are compared with the predictions of a mathematical model that is used to estimate the concentration profile within the pellet. The outlet concentration of the reactants and conversion products calculated by the mathematical model has been consistent with the results obtained by experiments conducted in a fixed bed reactor.

An equation-oriented approach was developed for steady state flowsheeting of a commercial methanol plant. The loop consists of fixed bed reactor, flash separator, preheater, coolers, and compressor. For steady sate flowsheeting of the plant mathematical model of reactor and other units are needed. Reactor used in loop is a Lurgi type and its configuration is rather complex. Previously reactor and flash separator are modeled as two important units of plant. The model is based on mass and energy balances in each equipment and utilizing some auxiliary equations such as rate of reaction and thermodynamics model for activity coefficients of liquid. In order to validate the mathematical model for the synthesis loop, some simulation data were performed using operating conditions and characteristics of the commercial plant. The good agreement between the steady state simulation results and the plant data shows the validity of the model.

Abstract: The use of mixed amine system in gas treating processes is increasing today. For natural gas sweetening purposes, mixed amines are typically mixtures of MDEA and DEA or MEA that enhance CO2 removal while retaining desirable characteristics of MDEA such as reduced corrosion problems and low heats of reaction. In this work, a process simulator was used to predict the performance of an Iranian gas sweetening plant with a sour gas feed containing 6.41% CO2 and 3.85% H2S on molar basis. Various mixtures of diethanolamine (DEA) and Methyl diethanolamine (MDEA) were used to investigate the potential for an increase in plant capacity. It was noticed that the process simulator is quite capable in predicting the existing plant performance and can potentially guide in selecting the optimum blend composition. It was also noticed that a substantial increase in plant capacity is quite possible by just adding MDEA to the existing solvent and keeping the solvent flow rate and stripper reboiler heat duty. In another word, it is possible to increase the plant capacity from 293 to 357 MMSCFD using a mixed amine system.

Abstract: Sylhet is the northeastern region of Bangladesh and probability of earthquake in Sylhet is higher than other areas of this zone. Among 27 wards, Ward no. 14 is one of the important largest Wards in Sylhet city and a densely populated one. It was clear from the survey works, 42.8% buildings are belongs to Building with RCC frame; 54.03% buildings are Masonry buildings. Another interesting finding is 325 houses fall in the category of Houses with resident 1-10. The occurrence of an earthquake of PGA value 0.9g on ward no. 14 causes massive loss of lives and damage to buildings. Depending on the time of the day 147 to 603 people may be killed due to structural collapse and the buildings of worth approximately TK.32.00 core may be damaged.

Abstract: The main objective of this study is estimating the strong motion for the Bam region using the stochastically based seismological models. The two widely used synthetic techniques namely; point-source and finite-fault were utilized incorporating the source-path and site parameters into simple function. The decay factor kappa was estimated based on the data obtained from recorded strong motions to be used as an appropriate factor for the region. The results were validated against those of the recorded data during the destructive 26 December 2003 Bam earthquake in south east of Iran. The efficiency of these methods and estimating the appropriate regional model parameters are the main objectives of this study. The results of the synthesized ground motion, such as acceleration time history, PGA and elastic response spectra were compared /assessed with those of observed data. The Bias model (MB) is used to assess the validation of the simulated earthquakes against recorded horizontal acceleration time histories. The %90 confidence interval of the means averaged over the whole stations using t-student distribution was evaluated and it was shown to be in an acceptable range. The elastic response spectra of the simulated strong motion are showed to be in a good agreement between the recorded waveforms confirming the acceptability of the selected/evaluated source-path-site model parameters. The sensitivity of the simulated PGA and response spectra against kappa factor as well as the path-averaged frequency-dependent quality factor Q, is studied and discussed.

The shipments of hazardous materials (HAZMATs) induce various risks to the road network. Today, one of the major considerations of transportation system managers is HAZMATs shipments, due to the increasing demand of these goods (because it is more used in industry, agriculture, medicine, etc.), and the rising number of incidents that are associated to hazardous materials.This paper presents a tool for HAZMATs transportation authorities and planners that would reduce the risk of the road network by identifying safe and economic routes for HM transshipment. Using the proposed linear integer programming model, the HM management system could determine an optimal assignment for all origin–destination pairs for various hazardous materials in a transportation network and so reduce the vulnerability due to HAZMATs releases such as population and environmental vulnerability. The model isimplemented and evaluated for the hazardous materials routing within Fars, Yazd, Isfahan, and Chaharmaha-o-Bakhtiyari provinces of Iran. The branchand- bound algorithm is applied to solve the model using the Lingo software package.