This paper presents a comprehensive literature review on the recent state-of-the-art technologies, sensor placement methodologies, dynamic evaluations and control strategies that have been proposed ...to improve the efficiency of integrated gasification combined cycle (IGCC) power plants. IGCC technologies and configurations including different types and designs of membranes, short residence-time gasifiers and new classes of turbines with higher firing temperature, represent promising economically attractive technologies for IGCC power plants and therefore are thoroughly reviewed in this work. Optimal sensor placement is critical since harsh operating conditions within specific IGCC components and budget constraints do not allow installing sensors that measure some key process variables for this system. The statistical approaches to determine the optimal number of sensors and their location in the plant are discussed. The dynamic performance of IGCC processes in closed-loop control is considered under critical scenarios using various tools such as process assessment under uncertainty, plant-wide and local control strategies. Major applications for each of these tools have been reported and discussed in detail. Furthermore, challenges and development potential for optimal sensor location and control systems for commercial IGCC power plants are outlined in this work.
Increased motility and invasiveness of pancreatic cancer cells are associated with epithelial to mesenchymal transition (EMT). Snai1 and Slug are zinc-finger transcription factors that trigger this ...process by repressing E-cadherin and enhancing vimentin and N-cadherin protein expression. However, the mechanisms that regulate this activation in pancreatic tumors remain elusive. MUC1, a transmembrane mucin glycoprotein, is associated with the most invasive forms of pancreatic ductal adenocarcinomas (PDA). In this study, we show that over expression of MUC1 in pancreatic cancer cells triggers the molecular process of EMT, which translates to increased invasiveness and metastasis. EMT was significantly reduced when MUC1 was genetically deleted in a mouse model of PDA or when all seven tyrosines in the cytoplasmic tail of MUC1 were mutated to phenylalanine (mutated MUC1 CT). Using proteomics, RT-PCR and western blotting, we revealed a significant increase in vimentin, Slug and Snail expression with repression of E-Cadherin in MUC1-expressing cells compared with cells expressing the mutated MUC1 CT. In the cells that carried the mutated MUC1 CT, MUC1 failed to co-immunoprecipitate with β-catenin and translocate to the nucleus, thereby blocking transcription of the genes associated with EMT and metastasis. Thus, functional tyrosines are critical in stimulating the interactions between MUC1 and β-catenin and their nuclear translocation to initiate the process of EMT. This study signifies the oncogenic role of MUC1 CT and is the first to identify a direct role of the MUC1 in initiating EMT during pancreatic cancer. The data may have implications in future design of MUC1-targeted therapies for pancreatic cancer.
•An advanced model based control strategy is proposed for a CO2 capture plant.•The proposed MPC-based control scheme was tested under various scenarios.•Optimal process scheduling for CO2 capture ...plants under disturbances is presented.
New environmental regulations on CO2 emission from coal-fired power plants will require significant carbon capture and sequestration capabilities. This will increase the need to develop advanced model-based control systems that are able to maintain the dynamic operability of CO2 capture plants in the presence of operational constraints and disturbances. This paper presents an advanced centralized multivariable model predictive control (MPC) technique, which considers energy and environmental constraints, to address the controllability of a post-combustion CO2 capture process from a coal-based power plant. To implement the MPC-based control strategy, an instant client–server data communication link between the process simulator and the control framework was implemented using component objective model technology. The case studies presented in this study show that MPC performs significantly better in terms of close-loop settling time, integral squared error and compliance of operational and environmental constraints when compared to a decentralized multi-loop control scheme based on proportional-integral (PI) controllers. The proposed MPC scheme is further implemented in a dynamic multi-objective optimization framework to address the optimal scheduling of the CO2 capture process under disturbances. The presented scheduling scenarios consider the dynamic performance of the system and can be used to design feasible and efficient operating policies for the CO2 capture plant.
In this study, the impact of Fe
3
O
4
nanoparticles (NPs) at different concentrations was studied on physiology, antioxidant enzymes, cell damage, and secondary metabolites of
Physalis alkekengi
...seedlings under in vitro conditions. Seeds were grown on a solid MS medium containing different Fe
3
O
4
NPs concentrations (0, 10, 20, and 30 mg/L). The results showed that Fe
3
O
4
NP at 20 mg/L increased growth (fresh and dry weight, length of shoot and root, and the number of adventitious roots) and physiological (relative water content, chlorophyll pigments, carotenoid, carbohydrate, H
2
O
2
, and ion leakage) parameters through stimulation of protein content and antioxidant enzyme activities of catalase (CAT), superoxide dismutase (SOD), and ascorbate peroxidase. Fe
3
O
4
NP at 20 mg/L was found to be the optimum concentration for enhancing secondary metabolites (total flavonoids, phenolics, and withanolides) and activity of DPPH radical scavenging and PAL, while the higher Fe
3
O
4
NPs concentration (30 mg/L) showed toxicity impact on growth parameters through promoting H
2
O
2
level, lipoxygenase activity, and ion leakage and inactivation of the antioxidant enzyme isoforms. The electrophoretic pattern displayed Fe
3
O
4
NPs at 30 mg/L decreased the band intensity of SOD (Mn-SOD and Cu/Zn-SOD1) and CAT (CAT1 and 2) isoforms. These findings display that the optimal dose of Fe
3
O
4
NPs (20 mg/L) acts as an elicitor to induce antioxidant functions of
P. alkekengi
cell system to suppress oxidative damage.
•A reactor network is presented for the modeling of CanmetENERGY’s gasifier.•Axial velocity, molar composition and temperature profiles are presented.•The model is compared to the results of ...corresponding CFD simulation.
State-of-the-art gasifiers require rapid mixing of fuel, steam and oxygen to achieve high carbon conversion within a short residence time. This allows reduction of the gasifier’s volume and the associated capital costs. CanmetENERGY of Natural Resources Canada has a pilot-scale gasifier that can convert solid fuels to syngas in less than 1s. This study describes the development of a reduced order model (ROM) for CanmetENERGY’s entrained flow short-residence time gasifier. The model consists of a reactor network that represents the gasifier using a set of chemical reactors that are aimed to capture distinct flow zones of the system. The layout of chemical reactors proposed in this work is based on computational fluid dynamics (CFD) simulations of the gasifier that accounted for the detailed gas and particle flows. The ROM implements sub-models for the simulation of drying, devolatilization, chemical reactions, viscous fluid–solid interactions, pollutant formation and heat transfer through the wall of the reactor. The predictions obtained by the ROM are in reasonable agreement with the CFD simulation data for axial temperature, heat flux, conversion and composition. Having established the flow pattern for a given gasifier and range of operating conditions, the proposed ROM is computationally efficient since it only requires 2.5min to converge whereas CFD simulations require 7–10days. This attractive feature enables integration of the gasifier ROM to process simulators for further development of integrated gasification combined cycle power plants.
•A dynamic model is presented for CanmetENERGY’s gasifier.•A new empirical correlation is proposed for recirculation ratio.•Transient experimental data was used to validate the model.
This study ...presents a dynamic reduced order model (ROM) that describes the transient behaviour of an entrained-flow slagging gasifier. A new correlation for estimation of the recirculation ratio in the ROM’s reactor network is presented in this work by using the ROM and experimental data. The proposed correlation improves the well-known method of Thring and Newby for jet-flow recirculation by adding a term that takes into account the changes in the feed streams (multi-phase jet and secondary flows) on the recirculation. This feature enhances the prediction capabilities of the reactor network, especially in dynamic simulations where the inlet flowrates may change over time, e.g., for load-following power plants. The proposed dynamic ROM has been validated using steady-state and transient experimental data. Furthermore, the dynamic responses of dry syngas composition, temperature distribution, cold gas efficiency, slag thickness and flowrate were studied under load-following and co-firing (petroleum coke/coal) scenarios.
MUC1 (CD227), a membrane tethered mucin glycoprotein, is overexpressed in >60% of human pancreatic cancers (PCs), and is associated with poor prognosis, enhanced metastasis and chemoresistance. The ...objective of this study was to delineate the mechanism by which MUC1 induces drug resistance in human (BxPC3 and Capan-1) and mouse (KCKO, KCM) PC cells. We report that PC cells that express high levels of MUC1 exhibit increased resistance to chemotherapeutic drugs (gemcitabine and etoposide) in comparison with cells that express low levels of MUC1. This chemo resistance was attributed to the enhanced expression of multidrug resistance (MDR) genes including ABCC1, ABCC3, ABCC5 and ABCB1. In particular, levels of MRP1 protein encoded by the ABCC1 gene were significantly higher in the MUC1-high PC cells. In BxPC3 and Capan-1 cells MUC1 upregulates MRP1 via an Akt-dependent pathway, whereas in KCM cells MUC1-mediated MRP1 upregulation is via an Akt-independent mechanism. In KCM, BxPC3 and Capan-1 cells, the cytoplasmic tail motif of MUC1 associates directly with the promoter region of the Abcc1/ABCC1 gene, indicating a possible role of MUC1 acting as a transcriptional regulator of this gene. This is the first report to show that MUC1 can directly regulate the expression of MDR genes in PC cells, and thus confer drug resistance.
Continuous genetic selection and improvement in nutrition have led to a very
fast growth rate in modern strains of broiler chickens. Metabolic disorders
such as ascits, sudden death syndrome and leg ...problems are related to a rapid
early growth rate in poultry, especially in broilers, and their incidence can
be decreased by slowing early growth. The use of management tools to reduce
metabolic disorders that rely primarily on decreasing feed consumption, The
feed restriction programs is on of the main techniques in growth curve
manipulation for increasing production efficiency in broiler chicken in
alleviate the incidence of some metabolic disorders and can be used to
reduction the unfavorable effects of fast growth rate in broiler chicken
production industry, and could be profitable in broiler chickens production
efficiency. This article implicated on new findings in about different feed
restriction programs effects on these problems in broiler chickens.
nema
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