Sharif Digital Repository

In this work, the concept of problem table decomposition for the thermal integration of continuous processes is extended to batch processes. The approach is based on a combination of time intervals using pinch analysis tools and energy storage system design. Pinch analysis improves energy efficiency for batch processes and it may increase the productivity of a revised plant. Operational and economical constraints may cause some limitation; therefore, in this approach process constraints and flexibilities are carefully considered by defining individual time and heat intervals. The approach is demonstrated on a case study. © 2005 Elsevier B.V. All rights reserved  

A method recently proposed for tuning fractional order [proportional integral] (FO[PI]) controllers is investigated. This tuning method, when applied in control of first-order plus dead time (FOPDT) processes, can ensure the desired phase margin, the desired gain crossover frequency and the flatness of the phase Bode plot at such a frequency. The necessary and sufficient condition for the applicability of the aforementioned tuning method is derived. Also, it is shown that this condition can be used in obtaining the achievable performance region of the tuning method in the gain crossover frequency-phase margin plane  

Application of nanoparticles for wettability alteration offers a practical approach to resolve some surface-related problems encountered in the nowadays technological process. Examples are underground/subsurface engineering implications, including the enhanced oil recovery from the oil-wet carbonate reservoirs. However, the common wettability evaluating techniques such as contact angle and flotation cannot be representative of the dynamic phenomena occurring at the pore scale and hence are unable to give accurate information about the process. Therefore, in the present work, the electrokinetic evaluations are utilized to explore the wettability alteration of initially oil-wet carbonate rock... 

Bias temperature instability (BTI) is known as one serious reliability concern in nanoscale technologies. BTI gradually increases the absolute value of threshold voltage (Vth) of MOS transistors. The main consequence of Vth shift of the SRAM cell transistors is the static noise margin (SNM) degradation. The SNM degradation of SRAM cells results in bit-flip occurrences due to transient faults and should be monitored accurately. This paper proposes a sensor called write current-based BTI sensor (WCBS) to assess the BTI-aging state of SRAM cells. The WCBS measures BTI-induced SNM degradation of SRAM cells by monitoring the maximum write current shifts due to BTI. The observations show that the... 

In this review, the importance of nanoparticles (NPs), with emphasis on their general and specific properties, especially the high surface-to-volume ratio (A/V), in many technological and industrial applications is studied. Some physical and chemical preparation methods for growing several metallic and binary alloy NP catalysts are reviewed. The growth and mechanism of catalytic reactions for synthesis of 1D nanostructures such as ZnO nanowires and multiwall carbon nanotubes (MWCNTs) are discussed. Gas-phase production with emphasis on dependence of catalytic activity and selectivity on size, shape and structure of NPs is also investigated. Application of NP catalysts in several... 

Optimization methods for process integration of industrial networks presented so far have dealt with grass-root situation. For retrofit ones, the actual design of the existing heat exchanger network must be taken into account. Berntsson and Stromberg (1996) developed new Composite Curves for use in a targeting and options scanning in retrofitting. The aim of this development has been to create Pinch Technology based methods, with which the general problems with process integration in Retrofit can be treated. New Pinch Technology based curves for retrofitting of heat exchanger networks have provided a graphical representation of existing HEN, including heaters and utility levels, from which... 

Intracellular production of recombinant proteins in prokaryotes necessitates subsequent disruption of cells for protein recovery. Since the cell disruption and subsequent purification steps largely contribute to the total production cost, scalable tools for protein release into the extracellular space is of utmost importance. Although there are several ways for enhancing protein release, changing culture conditions is rather a simple and scalable approach compared to, for example, molecular cell design. This contribution aimed at quantitatively studying process technological means to boost protein release of a periplasmatic recombinant protein (alkaline phosphatase) from E. coli....