Real-time dynamic optimization of batch systems

In this paper a methodology for designing and implementing a real-time optimizing controller for batch processes is proposed. The controller is used to optimize a user-defined cost function subject to a parameterization of the input trajectories, a nominal model of the process and general state and input constraints. An interior point method with penalty function is used to incorporate constraints into a modified cost functional, and a Lyapunov based extremum seeking approach is used to compute the trajectory parameters. The technique is applicable to general nonlinear systems. A precise statement of the numerical implementation of the optimization routine is provided. It is shown how one can take into account the effect of sampling and discretization of the parameter update law in practical situations. A simulation example demonstrates the applicability of the technique.     

Energy-efficient cooking methods

Energy-efficient new cooking techniques have been developed in this research. Using a stove with 649?±?20 W of power, the minimum heat, specific heat of transformation, and on-stove time required to completely cook 1 kg of dry beans (with water and other ingredients) and 1 kg of raw potato are found to be: 710 (±24)?kJ, 613 (±20)?kJ, and 1,144?±?10 s, respectively, for beans and 287?±?12 kJ, 200?±?9 kJ, and 466?±?10 s for Irish potato. Extensive researches show that these figures are, to date, the lowest amount of heat ever used to cook beans and potato and less than half the energy used in conventional cooking with a pressure cooker. The efficiency of the stove was estimated to be 52.5?±?2 %. Discussion is made to further improve the efficiency in cooking with normal stove and solar cooker and to save food nutrients further. Our method of cooking when applied globally is expected to contribute to the clean development management (CDM) potential. The approximate values of the minimum and maximum CDM potentials are estimated to be 7.5?×?10¹¹ and 2.2?×?10¹³?kg of carbon credit annually. The precise estimation CDM potential of our cooking method will be reported later.     

Mesoporous Natural Fiber Welded Cellulose Containing Silver Nanoparticles as a Recyclable Heterogeneous Catalyst

Silver nanoparticles (AgNPs) are presented within mesoporous natural fiber welded (NFW) cellulose and demonstrated as robust catalysts to reduce 4-nitrophenol using sodium borohydride. Growing AgNPs this way enables their retention within a nonderivatized, mesoporous, all-cellulose NFW composite. At an AgNP loading of 1.0 wt%, no leaching is observed during rinsing with polar and nonpolar solvents or any of 12 catalyst cycles and the cloth is easily retrievable and reusable. Comparatively, a 1.0 wt% AgNP loading on non-NFW cotton thread loses ≈95% of the starting Ag under similar conditions. Only at higher loadings is a very slow leaching observed in the NFW composite (<10% Ag loss). With a turnover frequency of 0.9 h^–1 (as compared to 2.2 h^–1 for the non-NFW cotton thread), the catalytic activity suffers only minor impedance from the NFW structure while affording significant promise in future applications for leach-resistant nonderivatized cotton (e.g., TiO₂ or photonic nanomaterials). Finally, it is shown that combustion of AgNPs-NFW composites creates Ag residues distinct from materials produced via combustion of AgNPs on non-NFW cotton. While the residues produced comprise Ag and residual carbon, this method is viable for producing metal “sponges” from monometallic and bimetallic NPs on mesoporous cellulose.     

Front Cover: Chemoselective Labeling and Immobilization of Phosphopeptides with Phosphorimidazolide Reagents (ChemBioChem 4/2023)

Protein phosphorylation is one of the most ubiquitous post-translational modifications, regulating numerous essential processes in cells. Accordingly, the large-scale annotation of phosphorylation sites continues to provide central insight into the regulation of signaling networks. The global analysis of the phosphoproteome typically relies on mass spectrometry analysis of phosphopeptides, with an enrichment step necessary due to the sub-stoichiometric nature of phosphorylation. Several affinity-based methods and chemical modification strategies have been developed to date, but the choice of enrichment method can have a considerable impact on the results. Here, we show that a biotinylated, photo-cleavable phosphorimidazolide reagent permits the immobilization and subsequent cleavage of phosphopeptides. The method is capable of the capture and release of phosphopeptides of varying characteristics, and this mild and selective strategy expands the current repertoire for phosphopeptide chemical modification with the potential to enrich and identify new phosphorylation sites in the future.     

Adding wind power to a wind-rich grid: Evaluating secondary suitability metrics

As the quantity of renewable electricity generation from wind farms increases in a region, the costs associated with integrating it into the broader electricity system also grow. This is primarily due to the need for dispatchable generators that vary power output to compensate for wind farm power variations. Such “balancing services” are an economic cost to the system that is typically not passed on to wind farms. We propose including the use of technical merits other than capacity factor and cost of energy for evaluating new wind farm sites and present a new graphical geospatial method, with the intention of identifying sites that minimize the need for additional electricity balancing service and transmission congestion. Specifically, locations with low correlation to existing wind farms, locations with high correlation to load, locations with high characteristic power time-shift from existing wind farms, and locations that relieve or do not negatively impact electricity transmission congestion are identified. A geospatial Venn diagram-based method of visualization is presented. These methods will equip regional planners with new tools to encourage wind farm development in areas that benefit the electricity grid beyond the lowest bid price.     

Electrochemical Characterization of Isolated Nitrogenase Cofactors from Azotobacter vinelandii

The nitrogenase cofactors are structurally and functionally unique in biological chemistry. Despite a substantial amount of spectroscopic characterization of protein-bound and isolated nitrogenase cofactors, electrochemical characterization of these cofactors and their related species is far from complete. Herein we present voltammetric studies of three isolated nitrogenase cofactor species: the iron–molybdenum cofactor (M-cluster), iron–vanadium cofactor (V-cluster), and a homologue to the iron–iron cofactor (L-cluster). We observe two reductive events in the redox profiles of all three cofactors. Of the three, the V-cluster is the most reducing. The reduction potentials of the isolated cofactors are significantly more negative than previously measured values within the molybdenum–iron and vanadium–iron proteins. The outcome of this study provides insight into the importance of the heterometal identity, the overall ligation of the cluster, and the impact of the protein scaffolds on the overall electronic structures of the cofactors.     

Naturalistic action impairment in closed head injury.

The authors sought to determine whether errors of action committed by patients with closed head injury (CHI) would conform to predictions derived from frontal lobe theories. In Study 1, 30 CHI patients and 18 normal controls performed routine activities, such as wrapping a present, under conditions of graded complexity. CHI patients committed more errors even on the simplest condition; but, except for a higher proportion of omitted actions, their error profile was very similar to that of controls. Study 2 involved a subset of patients whose performance in Study 1 was within normal limits. When these high functioning patients were asked to perform the routine tasks under still more taxing conditions, they, too, committed errors in excess of the control group. Accounts based on frontal mechanisms have a difficult time explaining the overall pattern of findings. An alternative based on limited-capacity resources is suggested. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Virtual reality (VR) for psychotherapy: From the physical to the social environment.

Discusses current and future therapeutic applications of virtual reality (VR). To date, treatments incorporating VR have involved the simulation of physical (as opposed to social) aspects of the environment. Researchers have produced simulations of heights, different kinds of spaces, and the experience of flying, with the goal of improving the delivery of exposure and desensitization for the treatment of phobias. Researchers are only beginning to explore simulation of the social environment. When VR gains the ability to simulate human social interaction, it can be used to assist in treating a wider variety of conditions, including social phobia, fear of intimacy, and sexual aversion. More long range goals are the use of VR for the exploration of childhood memories, overcoming maladaptive thinking, empowerment, increasing empathy, expressing emotions, developing and maintaining boundaries, and promoting marital satisfaction and bonding. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A Concurrent General Purpose Operator Interface

Compact interactive control consoles are rephcing traditional control rooms as operator interfaces for physical processes. In the irust major application of concurrent programming outside the area of operating systems, this paper presents a design for a general purpose operator interface which uses a color graphics terminal with a touch-sensitive screen as the control console. Operators interact with a process through a collection of application-dependent displays generated interactively by users familiar with the physical process. The use of concurrent programming results in a straightforward and reliable design which may easily be extended to support multiple devices of varying types in the control console. An implementation of the Operator Interface in Concurrent Pascal currently in progress is also discussed.