Process Simulation

This paper proposes a hazard-based environmental impact assessment approach (E-Impact), for evaluating the environmental impact during process design and retrofit stages. E-Impact replaces the normalisation step of the conventional impact assessment phase. This approach compares the impact scores for different options and assigns a relative score to each option. This eliminates the complexity of the normalisation step in the evaluation phase. The applicability of the E-Impact has been illustrated through a case study of solvent selection in an acrylic acid manufacturing plant. E-Impact is used in conjunction with Aspen-HYSYS process simulator to develop mass and heat balance data.

Ayuda. Buscador. Ver el registro completo y el enlace al documento. Registro completo. Recurso de origen, RUA. Repositorio Institucional de la Universidad de Alicante. Identificador, http://hdl.handle.net/10045/12217. Título, Heterogeneous ...

A Flow 3-D simulation is reported on the thermal phenomena that give rise to defects in LFC parts. In order to obtain a higher precision of the models, simple meshes and multiple blocks have been considered. Particularly, metal-foam heat transfer is used to calculate the lost foam volume and the rate of the filling process. High contraction points and defect concentration were obtained by means of the simulation of the solidification process, which facilitated the optimization of parameters at an industrial level, as well as the LFC production of hydrants.

Navigation based on cognition is seen in many instances in the animal communi@. Maps are very useful for navigation in unknown and complex environments. User defined andpreinstalled maps can be very useful in navigation in complex environments, while adaptively built maps become very essential in unknown environments. Intelligence is bestowed in the effective utilization of data to produce decisions. In the case of navigation. intelligence is seen when information collected en-routeRom a source to a destination is used judiciously in reaching the destination. In this paper we deal with the foraging of apiece of terrain as aprocess of navigation. The application here is mine detection. Mnes are placed over a field at unknown locations and swarm intelligence based agents are deployed for demining them. The efficiency of the deminingprocess is measured in terms of the quickness with which they can clear the mines and the assurance that the minefield is clear of all of the mines at the end of the process. Simulation results acknowledging the performance under different working conditions of the swarm robots are presented. In an endeuvor to substantiate our claims in simulation we decided to build swarm robots performing the task on an artifkially developed environment.

A method for process condition monitoring and evaluation, which combines the online support vector machine (SVM) regression and the fuzzy sets methods, is proposed. To account for the time dependence, the proposed approach is based on moving windows in order to take into account the past and new data for the model's adaptation. The fuzzy analysis is then applied to the generated residual data to give an evaluation of the condition monitoring. The proposed approach is applied to hot rolling for constructing a complementary condition monitoring system, which permits an online quality evaluation in the rolling process. Simulation results based on residual data show that the new approach is easily implementable.

The aim of this paper is to present the developed procedure for the simulation of the hot rolling process also referring to some patents. Rolling is a 3D process but using the generalized plane strain method, the real 3D problem can be solved using 2D Finite Element Model (FEM), saving an important computing time. Thus, this procedure is really useful to give assistance in the roll design and to obtain the stock cross-section temperature distribution in the whole rolling process. On the other hand, it is also presented the thermo-mechanical characterization of the R260 quality steel, 0.7% C pearlitic steel, commonly used in rail rolling. Finally, the procedure is applied to simulate the UIC-60 rail hot rolling. A good agreement between FEM results and the sample shapes was obtained in the ArcelorMittal, S.A. rail mill facility in Asturias (Spain).

This paper addresses the design and technoeconomic analysis of an integrated system for the production of biodiesel from algal oil produced via the sequestration of carbon dioxide from the flue gas of a power plant. The proposed system provides an efficient way to the reduction in greenhouse gas emissions and yields algae as a potential alternative to edible oils currently used for biodiesel production. Algae can be processed into algal oil by various pathways. The algal oil can then be used to produce biodiesel. A flowsheet of the integrated system is synthesized. Then, process simulation using ASPEN Plus is carried out to model a two-stage alkali catalyzed transesterification reaction for converting microalgal oil of Chlorella species to biodiesel. Cost estimation is carried out with the aid of ICARUS software. Further economic analysis is performed to determine profitability of the algal oil to biodiesel process. The results suggest that, for the algal oil to biodiesel process analyzed in this study, factors such as choosing the right algal species, using the appropriate pathway for converting algae to algal oil, selling the resulting biodiesel and glycerol at a favorable market selling prices, and attaining high levels of process integration can collectively render algal oil to be a competitive alternative to food-based plant oils.

This work deals with the main aspects of the thermochemical conversion of refuse derived fuels (RDF). In particular, a kinetic model of solid volatilization has been employed and validated. This kinetic model is based on a linear combination of the devolatilization models of the main constituent of the fuel. Ligno-cellulosic and plastic materials, together with ash and moisture, allow to account for the high heterogeneity of RDF. This devolatilization model is coupled with a detailed gas-phase oxidation and pyrolysis kinetics of the released gases. Furthermore, a fixed bed reactor model has been developed in order to describe solid fuel gasification. Gas-solid interactions as well as internal resistances are accounted for. The model predictions have been compared with experimental data with an encouraging agreement and they represent a good starting point for further analysis and considerations.

methodology and operating condition. In this paper, a reaction model (RXN model) based on comprehensive biomass gasification kinetics is introduced and validated to predict the syngas and tar compositions. By comparing the simulating predictions with data from two updraft gasification experiment findings available in the literature, it is demonstrated that the RXN model is able to provide a more accurate description for updraft biomass gasification than the minimizing Gibbs free energy model (MGFE model), which can substitute for the widely used yet not accurate MGFE model. Parametric optimization studies were conducted to investigate the impacts of equivalence ratio (ER), gasifier temperature, biomass feed types on syngas and unreacted tar compositions. The results of this work provide vital information for large-scale gasifier design, operating decisions, and optimization.

Most commercial process simulators have its origin at the petrochemical industry and their use in other sectors depends on testing. In this context a model of an industrial column system of bioethanol distillation heated by direct injection of vapor was developed and implemented using the simulator Aspen HYSYS, which was compared with experimental data obtained in the industrial plant. The system basically consists of four columns heated by direct vapor injection and the model of the system was developed using this approach together with the simulation blocks for columns heated by reboilers available on Aspen HYSYS. For such a task it was admitted a null termal load for the reboiler and a direct vapor stream was added in the side of the column. Overall deviations between simulated values and those measured in the distillery were 2.3 % for temperatures, 12.95 % for concentrations, and 1.07 % for bioethanol production in the industrial distillation system (IDS). The low values of the ...

The promise of process simulation has always been that it could replace costly experiments in the development of new technology. The reality has been far less, primarily because of deficiencies in the physical models underlying such simulations. This situation is changing rapidly however, as better physically based models are developed. This paper describes recent progress in developing physically based process simulators like SUPREM. A number of examples will be shown which will illustrate the growing predictive power of such TCAD tools, even for silicon structures well beyond current manufacturing practice.

Readily available process, device, and circuit simulation programs have been integrated into an effective system for enhancing semiconductor product development. In this paper, the system will be discussed with particular emphasis on the problems encountered in making simulation tools accessible to users. Each of the primary pro grams is reviewed, and the modifications and enhancements which have been made to adapt the programs to our requirements are discussed. The problem of interpolating impurity concentration profiles between process simulation grids and device simulation grids is discussed. The link between device simulation and circuit simulation is parameter ex traction. The application of optimization techniques for parameter ex traction is considered.

Readily available process, device, and circuit simulation programs have been integrated into an effective system for enhancing semiconductor product development. In this paper, the system will be discussed with particular emphasis on the problems encountered in making simulation tools accessible to users. Each of the primary pro grams is reviewed, and the modifications and enhancements which have been made to adapt the programs to our requirements are discussed. The problem of interpolating impurity concentration profiles between process simulation grids and device simulation grids is discussed. The link between device simulation and circuit simulation is parameter ex traction. The application of optimization techniques for parameter ex traction is considered.

Simulating and optimising the powder injection process are complex problems since a number of linked material, geometry and process variables have to be considered. In addition, it is very difficult to identify critical parameters for designing binder systems, feedstocks, parts, moulds and processing conditions owing to the fact that multiple objective functions have to be considered. Towards the goal of identifying the level of significance of various material, process and geometry parameters during powder injection moulding, a systematic procedure for sensitivity analysis has been successfully developed for the mould filling phase of the PIM process. In this sensitivity analysis, all input parameters were defined for the mould filling simulation and all output parameters for optimum design of part, mould and processing conditions and dimensionless sensitivity values for all input and output parameters were calculated, which allow parameters with different units to be compared quantitatively. The sensitivity analysis procedure developed will be an invaluable tool for both the design engineer in the PIM industry who has to determine the critical input parameters for given design targets, as well as for the production engineer who has to optimise and monitor the production stage.

Many firms anticipate that a cap on greenhouse gas emissions will eventually be imposed, either through an international agreement like the Kyoto protocol or through domestic policy, and have started to take voluntary actions to reduce their emissions. If agricultural producers participate in the emerging market for tradable C-credits, it must be possible to verify that actions farmers take do increase the amount of C in soils and this increase can be maintained over the length of the contract. In this paper we develop a prototype measurement and monitoring scheme for C-credits sequestered in agricultural soils and estimate its costs for the small grain-producing region of Montana using an econometric-process simulation model. Three key results emerge from the prototype framework. First, the efficiency of measurement and monitoring procedures for agricultural soil C sequestration depends on the price of C credits. Second, we find that at all price levels, costs of measuring and moni...

We developed and implemented an intelligent control system to be used in an extractive distillation column that produces anhydrous ethanol using ethylene glycol as solvent. The concept of artificial neural networks (ANN) was used to predict new setpoints after disturbances, and proved to be a fast and feasible solution. The developed control system receives data from temperature, flowrate and composition measurements of the azeotrope feed, and the ANN estimates the new set-points of the controllers to maintain 99.5 mol% of ethanol at the top and less than 0.1 mol% at the bottom; feed composition was also estimated using an ANN. All ANN were trained to provide output data corresponding to an optimized operating condition. The results showed that the intelligent control system can predict a new operating condition for any disturbance in the column feed and presented superior performance when compared with the control system without ANN.

The separation of binary mixtures which form azeotropes is not possible through conventional distillation and they are usually separated by extractive or azeotropic distillation. The optimization of extractive distillation columns is usually performed using a process simulator; however, normally, the result is only obtained after several simulations and the simultaneous analysis of several graphs. This paper sets out to present a systematic procedure, using a process simulator (Aspen Plus ® ), in order to obtain the optimum condition for extractive distillation columns. The optimization achieved is characterized by the fact that it is not necessary to perform various simulations, and it also avoids the simultaneous analysis of dozens of curves. The dehydration of aqueous mixtures of ethanol using ethylene glycol as solvent was the system chosen as a case study.

A system for geometric and physical simulation of the ball-end milling process using solid modeling is presented in this paper. A commercially available geometric engine is used to represent the cutting edge, cutter and updated part. The ball-end mill cutter modeled in this study is an insert type ball-end mill and the cutting edge is generated by intersecting an inclined plane with the cutter ball nose. The contact face between cutter and updated part is determined from the solid model of the updated part and cutter solid model. To determine cutting edge engagement for each tool rotational step, the intersections between the cutting edge with boundary of the contact face are determined. The engaged portion of the cutting edge for each tool rotational step is divided into small differential oblique cutting edge segments. Friction, shear angles and shear stresses are identified from orthogonal cutting data base available in the open literature. For each tool rotational position, the cutting force components are calculated by summing up the differential cutting forces. The instantaneous dynamic chip thickness is computed by summing up the rigid chip thickness, the tool deflection and the undulations left from the previous tooth, and then the dynamic cutting forces are obtained. For calculating the ploughing forces, Wu's model is extended to the ball-end milling process . The total forces, including the cutting and ploughing forces, are applied to the structural vibratory model of the system and the dynamic deflections at the tool tip are predicted. The developed system is verified experimentally for various up-hill and downhill angles.

This paper has two parts. In the first part we present: "The Development of the Scheme of Computation for Stirling Cycle with Finite Speed Performances (Efficiency and Power)". Because this Computation Scheme of the Performances (Efficiency and Power) is the most important Achievement of the Direct Method utilization, from Thermodynamics with Finite Speed, we describe here the "process of its discovery and invention" from the epistemological point of view, in order to show how important is and was (for me, SP) the connection between teaching and research in generating and developing new ideas. In the Second part of this Chapter we developed this Scheme, showing also its Validation on 12 of the most performing Stirling Engines in the world (USA,

This paper has two parts. In the first part we present: "The Development of the Scheme of Computation for Stirling Cycle with Finite Speed Performances (Efficiency and Power)". Because this Computation Scheme of the Performances (Efficiency and Power) is the most important Achievement of the Direct Method utilization, from Thermodynamics with Finite Speed, we describe here the "process of its discovery and invention" from the epistemological point of view, in order to show how important is and was (for me, SP) the connection between teaching and research in generating and developing new ideas. In the Second part of this Chapter we developed this Scheme, showing also its Validation on 12 of the most performing Stirling Engines in the world (USA,

This paper has two parts. In the first part we present: "The Development of the Scheme of Computation for Stirling Cycle with Finite Speed Performances (Efficiency and Power)". Because this Computation Scheme of the Performances (Efficiency and Power) is the most important Achievement of the Direct Method utilization, from Thermodynamics with Finite Speed, we describe here the "process of its discovery and invention" from the epistemological point of view, in order to show how important is and was (for me, SP) the connection between teaching and research in generating and developing new ideas. In the Second part of this Chapter we developed this Scheme, showing also its Validation on 12 of the most performing Stirling Engines in the world (USA, Japan, Germany, Sweden), and 16 Operating Regimes.

The rapid increase in emergency department admissions often leads to overcrowding, leading to disruptions in treatments, an increase in workload, a decrease in service quality, and the emergence of administrative difficulties. As in all service sectors, it is extremely important to make appropriate planning to provide quality and timely service in health enterprises. This study, conducted in a public hospital emergency department, proposes a new triage practice in emergency departments. According to the proposed triage practice, the duration of the patients' stay in the emergency room and the waiting time between processes are shortened, and appropriate personnel planning that will not endanger the health and safety of the patients has been arranged. According to the simulation data created based on the recommended triage practice, it was determined that the duration of stay of yellow-tagged patients in the emergency room could decrease by 44.45% and by 83.44% in the waiting time in the first examination queue. In addition, with the new personnel plan, it is foreseen that 20.24% of the working hours of the doctor, 30% of the working hours of the nurse, 40% of the working hours of the medical secretary, and 50% of the working hours of the registry staff can be achieved.

Working with leading experts in the field of cognitive neuroscience and computational intelligence, SNL has developed a computational architecture that represents neurocognitive mechanisms associated with how humans remember experiences in their past. The architecture represents how knowledge is organized and updated through information from individual experiences (episodes) via the cortical-hippocampal declarative memory system. We compared the simulated behavioral characteristics with those of humans measured under well established experimental standards, controlling for unmodeled aspects of human processing, such as perception. We used this knowledge to create robust simulations of & human memory behaviors that should help move the scientific community closer to understanding how humans remember information. These behaviors were experimentally validated against actual human subjects, which was published. An important outcome of the validation process will be the joining of specific experimental testing procedures from the field of neuroscience with computational representations from the field of cognitive modeling and simulation.

This work tackles the question of power generation by means of gasification. Growing economies and global warming are important challenges these years: so that cleaner and more efficient power plants designs have to be achieved. In this context, Integrated Gasification Combined Cycle (IGCC) power plants have an important role, due to their more efficient way of producing energy since fossil fuels. Actions are focused on clean power and H 2 from coal, and also in bioproducts. So, one of the future of coal-based power generation strategies should be CO 2 transport and storage in order to obtain a purer hydrogen stream. This work proposes a tool for estimating final plant outputs and economics for different scenarios. The technical performance has been modeled in Aspen Hysys and Aspen Plus, and models have been validated with real power plant data. Comparisons, in terms of power, emissions, efficiencies and costs between sixteen different plant designs are presented: they enhance differences in raw material, purification units layout, and hydrogen obtention.

Ilmenite smelting: the basics by P.C. Pistorius* While some of the practical details of ilmenite smelting are not well documented, there is a substantial body of literature on the principles of ilmenite smelting, and the behaviour of solidified titania slag. This information is summarized, focusing on the basic reactions, departure from equilibrium, the behaviour of impurities, and reactions of solidified slag. The emphasis is on the South African operations.

In ilmenite smelting, the FeO content of the feed material (nominally FeO.TiO 2 ) is decreased by reduction with carbon. In a parallel reaction, a significant amount of the TiO 2 is reduced to Ti 2 O 3 . One of the striking features of these reactions is a consistent relationship between the extents of FeO and TiO 2 reduction; this relationship is independent of furnace size. It was recently proposed that this relationship follows from the solidification behaviour of the slag, where the final slag composition corresponds to the minimum melting point ('eutectic groove') in the FeO-TiO 2 -Ti 2 O 3 phase system; the hypothesis is that solidification equilibrium with the freeze lining stabilizes the slag composition. If this is the case, the system of slag and freeze lining must be capable of correcting two types of disturbances: thermal and compositional. Thermal disturbances result from incorrect power input, for the feed rates of ilmenite and reductant. For example, excessive power input will tend to overheat the slag, causing the freeze lining to melt partially, establishing a new steady-state heat loss from the furnace. Compositional disturbances result from an incorrect reductant input for the given power and ilmenite input. In this work, the dynamic response of the slag and freeze lining to different inputs (flow rates of ilmenite and reductant, and power input) is modelled. The model is based on solidification equilibria, and quantified heat loss through the freeze lining. The conclusion is that the solidification equilibrium cannot constrain the composition to the eutectic groove for typical operating conditions.

Currently, in the United States, nearly 58 million tires per year (ϳ640,000 tons) are discarded typically in landfills, which pose serious environmental issues because of their durability and strong tendency to leach toxic chemicals. A novel process intensification design (integrated combustion-gasification reactor) to convert waste tires to useful raw materials, such as syngas (CO and H 2 ), has been investigated. This work will report on the findings from a series of thermogravimetric analyses (TGA) experiments at various heating rates on styrene-butadiene copolymer (SBR) and polyisoprene (IR) and the effects of various atmospheres (7% O 2 /N 2 , Air, 30%O 2 /N 2 , 3%H 2 /N 2 ) on the combustion and gasification processes. The results indicate that oxygen enhanced atmospheres only have a significant effect on increasing combustion efficiency at low heating rates, such as 10°C/min. An unexpected result of the N 2 -O 2 tests was the development of a plateau in mass-loss vs. temperature curves, at 700°C. Polyisoprene thermograms in 7% O 2 /N 2 atmosphere, plateau was detected only at a low heating rate, such as 10°C/min. Furthermore, the amount of tar created is significantly different; polyisoprene generates much more tar. Measured data were used to obtain the kinetics of the significant reactions of waste tire conversion. That was combined with thermodynamic values from the literature and programmed into Aspen™ to simulate the integrated process. The results for a hypothetical reactor that consumes 10 million tires and 87,600 m 3 of water (in the form of sewage sludge) per year, produces 18.9% H 2 , 16.6% CO, 6.0% H 2 O, 8.4% CO 2 , and 49.9% N 2 of syngas. The total energy output is 28.6 MW of sensible heat and 103 MW of chemical energy.

The purpose of this paper is to evaluate the impact of the geometry of embedded Si 1Àx Ge x source/drain junctions on the stress field. Stress simulations were performed using TSUPREM4 2D software to further investigate the elastic strain relaxation as a function of Si 1Àx Ge x alloy active size, in the regime where no plastic relaxation is present. Moreover, the role of the epilayer thickness and the Ge content on the stress levels is also discussed. The work is complemented with experimental Raman spectroscopy.

HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

ABSTRACTProcess simulation are performed in order to simulate the full fabrication process of an alternative nano-flash memory in order to optimise it and to improve the understanding of the dot storage formation. The influence of various parameters (oxidation temperature, nanowire shape) have been investigated.

In this work a new control strategy for grain aeration systems was proposed. This strategy was implemented in a software package called AERO and relates four conditions which depend on real time data acquisition and on the process simulation. The main advantage of AERO controller is that it can be used in different geographic regions, during different seasons and with different aeration systems, automatically adjusting its set points. The objectives of AERO controller are to equalize the temperatures inside the bin, to cool the grain mass whenever is possible and to maintain the moisture content under safe conditions. The results showed that the proposed strategy is efficient to achieve these objectives. Moreover, significant energy saving has been achieved with the AERO controller.

Chemical process simulation (CPS) software has been widely used by chemical (process) engineers to design, test, optimise, and integrate process plants. It is expected that industrial ecologists to bring these same problem-solving benefits to the design and operation of industrial ecosystems can use CPS. This paper provides industrial ecology researchers and practitioners with an introduction to CPS and an overview of chemical engineering design principles. The paper highlights recent research showing that CPS can be used to model industrial ecosystems, and discusses the benefits of using CPS to address some of the technical challenges facing companies participating in an industrial ecosystem. CPS can be used to (i) quantitatively evaluate and compare the potential environmental and financial benefits of material and energy linkages; (ii) solve general design, retrofit, or operational problems; (iii) help to identify complex and often counter-intuitive solutions; and (iv) evaluate what-if scenarios. CPS should be a useful addition to the industrial ecology toolbox.

Chemical process simulation (CPS) software has been widely used by chemical (process) engineers to design, test, optimise, and integrate process plants. It is expected that industrial ecologists to bring these same problem-solving benefits to the design and operation of industrial ecosystems can use CPS. This paper provides industrial ecology researchers and practitioners with an introduction to CPS and an overview of chemical engineering design principles. The paper highlights recent research showing that CPS can be used to model industrial ecosystems, and discusses the benefits of using CPS to address some of the technical challenges facing companies participating in an industrial ecosystem. CPS can be used to (i) quantitatively evaluate and compare the potential environmental and financial benefits of material and energy linkages; (ii) solve general design, retrofit, or operational problems; (iii) help to identify complex and often counter-intuitive solutions; and (iv) evaluate what-if scenarios. CPS should be a useful addition to the industrial ecology toolbox.

The opportunity to present a presidential address provides a rare and unique opportunity. It is perhaps the only time one gets to speak to the profession without your material either being reviewed and corrected before its presentation, or reviewed and corrected by a discussant after your presentation. Indeed the freedom that a presidential address offers takes a little getting used to, but it provides a wonderful opportunity to express one's biases. To you, the members of the profession who took the risk to allow me this opportunity, let me say thank you. I have chosen to use this opportunity to address a topic that I think provides one of the most exciting and potentially productive challenges our profession will face in our lifetimes, that is “The Dawning of the Age of Dynamic Theory.”

In this study, an industrial acid gas removal (AGR) process which uses amine-based solvents was designed and simulated. The selection of suitable absorbents is crucial for an effective AGR process. Therefore, various single and blended amine-based solvents for capturing acid gases were evaluated through a comprehensive procedure, including solvent screening and process design steps. First, various solvents were screened for their CO 2 and H 2 S absorption efficiencies. Promising solvents were then selected for the process design step, in which all process alternatives were simulated and rigorously designed using Aspen Plus. The non-equilibrium rate-based method with an electrolyte non-random two-liquid thermodynamic model was employed for modeling the absorption column. All processes were evaluated in terms of energy requirements, costs, and carbon emissions. The results show that a blend of methyldiethanolamine and piperazine solutions are the most promising solvents for the AGR process, as they can save up to 29.1% and 30.3% of the total annual costs and carbon emissions, respectively, compared to the methyldiethanolamine + diethanolamine solvent process.

In this study, an industrial acid gas removal (AGR) process which uses amine-based solvents was designed and simulated. The selection of suitable absorbents is crucial for an effective AGR process. Therefore, various single and blended amine-based solvents for capturing acid gases were evaluated through a comprehensive procedure, including solvent screening and process design steps. First, various solvents were screened for their CO2 and H2S absorption efficiencies. Promising solvents were then selected for the process design step, in which all process alternatives were simulated and rigorously designed using Aspen Plus. The non-equilibrium rate-based method with an electrolyte non-random two-liquid thermodynamic model was employed for modeling the absorption column. All processes were evaluated in terms of energy requirements, costs, and carbon emissions. The results show that a blend of methyldiethanolamine and piperazine solutions are the most promising solvents for the AGR proce...

This report evaluates the feasibility of high-level radioactive waste disposal in shale within the United States. The U.S. has many possible clay/shale/argillite basins with positive attributes for permanent disposal. Similar geologic formations have been extensively studied by international programs with largely positive results, over significant ranges of the most important material characteristics including permeability, rheology, and sorptive potential. This report is enabled by the advanced work of the international community to establish functional and operational requirements for disposal of a range of waste forms in shale media. We develop scoping performance analyses, based on the applicable features, events, and processes identified by international investigators, to support a generic conclusion regarding post-closure safety. Requisite assumptions for these analyses include waste characteristics, disposal concepts, and important properties of the geologic formation. We then apply lessons learned from Sandia experience on the Waste Isolation Pilot Project and the Yucca Mountain Project to develop a disposal strategy should a shale repository be considered as an alternative disposal pathway in the U.S. Disposal of high-level radioactive waste in suitable shale formations is attractive because the material is essentially impermeable and self-sealing, conditions are chemically reducing, and sorption tends to prevent radionuclide transport. Vertically and laterally extensive shale and clay formations exist in multiple locations in the contiguous 48 states. Thermal-hydrologicmechanical calculations indicate that temperatures near emplaced waste packages can be maintained below boiling and will decay to within a few degrees of the ambient temperature within a few decades (or longer depending on the waste form). Construction effects, ventilation, iv and the thermal pulse will lead to clay dehydration and deformation, confined to an excavation disturbed zone within a few meters of the repository, that can be reasonably characterized. Within a few centuries after waste emplacement, overburden pressures will seal fractures, resaturate the dehydrated zones, and provide a repository setting that strongly limits radionuclide movement to diffusive transport. Coupled hydrogeochemical transport calculations indicate maximum extents of radionuclide transport on the order of tens to hundreds of meters, or less, in a million years. Under the conditions modeled, a shale repository could achieve total containment, with no releases to the environment in undisturbed scenarios. The performance analyses described here are based on the assumption that long-term standards for disposal in clay/shale would be identical in the key aspects, to those prescribed for existing repository programs such as Yucca Mountain. This generic repository evaluation for shale is the first developed in the United States. Previous repository considerations have emphasized salt formations and volcanic rock formations. Much of the experience gained from U.S. repository development, such as seal system design, coupled process simulation, and application of performance assessment methodology, is applied here to scoping analyses for a shale repository. A contemporary understanding of clay mineralogy and attendant chemical environments has allowed identification of the appropriate features, events, and processes to be incorporated into the analysis. Advanced multi-physics modeling provides key support for understanding the effects from coupled processes. The results of the assessment show that shale formations provide a technically advanced, scientifically sound disposal option for the U.S. v Acknowledgement

A physical model of a continuous paper pulp digester is simplified and two subprocesses selected from the digester are modelled by coupled linear partial differential equations. This study focuses on the parameter identification of the simplified linear models. Finitedimensional approximation of the model is made and a software package developed for identification of distributed parameter processes is applied. This identification system is developed for flexibility to allow identification for different choices of subprocesses and process variables. Unknown parameters of the subprocess models are estimated and the results are illustrated by process simulation and model validation.

Studies on analysis, design and applications of analog and digital differentiators and integrators of fractional order is the main objective of this paper. Time and frequency domain analysis, different ways of realization of fractance device is presented. Active and passive realization of fractance device of order 1 2 using continued fraction expansion is carried out. Later, time and frequency domain analysis of fractance based circuits is considered. The variations of rise time, peak time, settling time, time constant, percent overshoot with respect to fractional order a is presented. Digital differentiators and integrators of fractional order can be obtained by using direct and indirect discretization techniques. The s to z transforms used for this purpose are revisited. In this paper by using indirect discretization technique fractional order differentiators and integrators of order 1 2 and 1 4 are designed. These digital differentiators and integrators are implemented in real time using TMS320C6713 DSP processor and tested using National instruments education laboratory virtual instrumentation system (NIELVIS). The designed fractional order differentiators have been used for the detection of QRS sequences as well as the occurrence of Sino Atrial Rhythms in an ECG signal and also for the detection of edges in an image. The obtained results are in comparison with the conventional techniques.

This paper describes a framework offering educational services for chemical plant operators using a process model simulated in real time over the Internet. An application service provider (ASP) approach avoids the barrier of capital investment of a site-based installation. Simulation-based education can be made available for virtually anyone at any time and anywhere through the use of thin clients. At the same time, the maintainability of the server software and model is greatly increased through the centralization of the simulation server. The utility described uses a rigorous dynamic process model for simulation but requires only a computer with a web browser and an Internet connection to establish real-time data communication with the simulation server.

The visual appearance and mechanical properties of aluminium alloy extrusions are strongly dependent on the microstructure and texture of the extruded profiles, where the desired microstructure and texture may depend on the specific applications. In the present work, the evolution of deformation, as well as recrystallization textures during extrusion of AA6xxx aluminium alloys, have been experimentally and numerically investigated. Extrusion trials were performed in a laboratory extrusion setup , which enabled immediate water-quenching of the profiles at the exit of the die, and thus the possibility to capture the deformation texture prior to post-extrusion recrystallization. The textures and their through-thickness variations were experimentally measured by the electron back-scatter diffraction technique (EBSD, and the deformation textures numerically modelled by coupling FEM flow simulations and crystal plasticity (CP) simulations. Different CP models as well as different choices of model parameters were employed and evaluated for texture predictions. With an appropriate choice of crystal plasticity model and model parameters, the deformation texture can mainly be predicted, although the accurate intensities are hard to reproduce. The corresponding recrystallization textures, either generated through spontaneous recrystallization of the extruded profiles or through post-extrusion annealing, are far more challenging to reproduce with available recrystallization models.