Constrained Online Optimization Using Evolutionary Operation: A Case Study About Energy‐Optimal Robot Control

Optimization of full‐scale processes during regular production is a challenge that is often encountered in practice, requiring specialized approaches that only introduce small perturbations so that production does not need to be interrupted. Based on a case study, we discuss the potential of Evolutionary Operation (EVOP) derived methods. The case study relates to a badminton robot that has to perform point‐to‐point motions during a fixed time interval, based on two operation modes: time‐optimal motion, which ensures maximum precision but highest energy consumption, and energy‐optimal motion, which decreases the energy consumption, but as a trade‐off also lowers the precision. The current standard mode of operation is the energy‐optimal mode that is constructed from off‐line optimization on simulations. An online EVOP steepest ascent optimization to further reduce the energy consumption by fine‐tuning the implemented energy‐optimal mode was implemented. The constrained nature of the problem, where energy needs to be minimized subject to a time constraint, was transformed to an unconstrained single‐objective optimization using Derringer desirability functions. Two important contributions were made: (i) the online optimization of the energy‐optimal motion lowered the energy consumption by 4.7% while keeping the precision constant and (ii) the more stringent time‐constraints implemented in desirability functions lead to an operation mode with maximum precision and 51.7% less energy consumption than the current time‐optimal motion. Copyright © 2014 John Wiley & Sons, Ltd.     

Engineered Nanoscale Food Ingredients: Evaluation of Current Knowledge on Material Characteristics Relevant to Uptake from the Gastrointestinal Tract

The NanoRelease Food Additive project developed a catalog to identify potential engineered nanomaterials (ENMs) used as ingredients, using various food‐related databases. To avoid ongoing debate on defining the term nanomaterial, NanoRelease did not use any specific definition other than the ingredient is not naturally part of the food chain, and its dimensions are measured in the nanoscale. Potential nanomaterials were categorized based on physical similarity; analysis indicated that the range of ENMs declared as being in the food chain was limited. Much of the catalog's information was obtained from product labeling, likely resulting in both underreporting (inconsistent or absent requirements for labeling) and/or overreporting (inability to validate entries, or the term nano was used, although no ENM material was present). Three categories of ingredients were identified: emulsions, dispersions, and their water‐soluble powdered preparations (including lipid‐based structures); solid encapsulates (solid structures containing an active material); and metallic or other inorganic particles. Although much is known regarding the physical/chemical properties for these ingredient categories, it is critical to understand whether these properties undergo changes following their interaction with food matrices during preparation and storage. It is also important to determine whether free ENMs are likely to be present within the gastrointestinal tract and whether uptake of ENMs may occur in their nanoform physical state. A practical decision‐making scheme was developed to help manage testing requirements.     

Fava bean (Vicia faba L.) for food applications: From seed to ingredient processing and its effect on functional properties,antinutritional factors,flavor, and color

The food industry, along with the consumers, is interested in plant-based diet because of its health benefits and environmental sustainability. Vicia faba L. (V. faba) is a promising source of pulse proteins for the human diet and can yield potential nutritional and functional ingredients, namely, flours, concentrates, and isolates, which are relevant for industrial food applications. Different processes produce and functionalize V. faba ingredients relevant for industrial food applications, along with various alternatives within each unit operation used in their production. Processing modifies functional properties of the ingredients, which can occur by (i) changing in overall nutritional composition after processing steps and/or (ii) modifying the structure and conformation of protein and of other components present in the ingredients. Furthermore, V. faba limitations due to off-flavor, color, and antinutritional factors are influenced by ingredient production and processing that play a significant role in their consumer acceptability in foods. This review attempts to elucidate the influence of different ways of processing on the functional, sensory, and safety aspects of V. faba L. ingredients, highlighting the need for further research to better understand how the food industry could improve their utilization in the market.     

Single-phase and two-phase magnetohydrodynamic pipe flow

Experimental results are presented for a range of measured temperatures and other parameters of vertically downward flows, both single-phase (sodium) and two-phase (sodium-nitrogen), in a conducting-wall pipe in the presence of a transverse magnetic field. Existing MHD theory predicted, to within experimental error, all single-phase pressure differences for magnetic interaction parameter values of up to approximately 100, beyond which the single-phase normalized resistance coefficients were noticeably lower than the laminar-flow predictions. The magnetic interaction parameter at which such deviation occurred was governed by the conductivity ratio. Two-phase pressure differences were obtained across a range of void fractions, approximately 0.3-0.8, where two distinct flow regimes were encountered. For those two regimes, the normalized resistance coefficients of pressure difference were predicted to within experimental error by the corresponding two-phase MHD pressure-difference models. In half of the two-phase cases examined, decreases were observed in normalized resistance coefficients at high values of the magnetic interaction parameter, a trend similar to that found in single-phase flow. The wall-voltage profiles of single-phase flows were symmetric with respect to the center of the applied magnetic field region; two-phase wall-voltage profiles were asymmetric because of the expansion of the gaseous nitrogen along the length of the test section. The influence of temperature and other system parameters upon pressure differences and wall voltages, and the possible effect of ‘M-shaped’ velocity profiles in the two types of flow are discussed.     

Situations matter: Teaching the Lewinian link between social psychology and rehabilitation psychology.

A little-recognized fact is that social psychology and rehabilitation psychology share a common theoretical ancestry in the situation perspective of Kurt Lewin. Theory and research in both fields assumes that situational influences often override the impact of personal factors, including dispositions. Situational analyses led to the development of a variety of cognitive explanations capturing people's phenomenal accounts for the causes of behavior and concomitant interpretation of social problems. Teachers can explore reasons why, despite the fields' having a shared theoretical perspective and topics of common interest (e.g., attitudes, prejudice, discrimination), little scholarly intradisciplinary contact currently occurs between them. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

The invisible benefits of exercise.

Objective: To examine whether—and why—people underestimate how much they enjoy exercise. Design: Across four studies, 279 adults predicted how much they would enjoy exercising, or reported their actual feelings after exercising. Main Outcome Measures: Main outcome measures were predicted and actual enjoyment ratings of exercise routines, as well as intention to exercise. Results: Participants significantly underestimated how much they would enjoy exercising; this affective forecasting bias emerged consistently for group and individual exercise, and moderate and challenging workouts spanning a wide range of forms, from yoga and Pilates to aerobic exercise and weight training (Studies 1 and 2). We argue that this bias stems largely from forecasting myopia, whereby people place disproportionate weight on the beginning of a workout, which is typically unpleasant. We demonstrate that forecasting myopia can be harnessed (Study 3) or overcome (Study 4), thereby increasing expected enjoyment of exercise. Finally, Study 4 provides evidence for a mediational model, in which improving people's expected enjoyment of exercise leads to increased intention to exercise. Conclusion: People underestimate how much they enjoy exercise because of a myopic focus on the unpleasant beginning of exercise, but this tendency can be harnessed or overcome, potentially increasing intention to exercise. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Pressurized water reactor (PWR) hot-leg streaming: Part 1: Computational fluid dynamics (CFD) simulations

A thermo-hydraulic analysis model was developed to analyze thermal stratification phenomena observed in the hot-legs of pressurized water reactors (PWR). The model uses VIPREW code to determine the flow field and temperature distribution in the reactor fuel region. The temperature readings from the thermal couples located at the exit of the reactor core were used to compare with the VIPREW computed results. The predicted values agree well with the measurements. The VIPREW results are then used as the boundary conditions for the CFD analysis. The CFD computational domain includes the upper plenum and hot-legs and the fifty two (52) control rod guiding tubes to properly include the additional obstructions imposed to the fluid. Different fuel loading patterns were studied to investigate the effects of different power distribution and fuel channel exit water temperature on hot-leg thermal stratification magnitude. The analysis results show that the 52 control rod guide tubes have major contribution to the mixing effect in the upper plenum. The sudden expansion of the cross sectional area in the upper plenum leads to the formation of recirculation vortex that prolongs the duration of coolant in the reactor vessel. The hotter coolant from the center portion tends to flow upwards to the top before exiting at the upper portion of the hot-leg pipes. It leads to higher temperature in the upper portion of the hot-legs. Water from the cooler outer fuel channels tends to trap in the recirculation region before exiting from the lower portion of the hot-legs.