Rational design of small molecular gelators is an elusive and herculean task, despite the rapidly growing body of literature devoted to such gels over the past decade. The process of self-assembly, ...in molecular gels, is intricate and must balance parameters influencing solubility and those contrasting forces that govern epitaxial growth into axially symmetric elongated aggregates. Although the gelator-gelator interactions are of paramount importance in understanding gelation, the solvent-gelator specific (i.e., H-bonding) and nonspecific (dipole-dipole, dipole-induced and instantaneous dipole induced forces) intermolecular interactions are equally important. Solvent properties mediate the self-assembly of molecular gelators into their self-assembled fibrillar networks. Herein, solubility parameters of solvents, ranging from partition coefficients (log P), to Henry's law constants (HLC), to solvatochromic parameters (ET(30)), and Kamlet-Taft parameters (β, α and π), and to Hansen solubility parameters (δp, δd, δh), are correlated with the gelation ability of numerous classes of molecular gelators. Advanced solvent clustering techniques have led to the development of a priori tools that can identify the solvents that will be gelled and not gelled by molecular gelators. These tools will greatly aid in the development of novel gelators without solely relying on serendipitous discoveries. These tools illustrate that the quest for the universal gelator should be left in the hands of Don Quixote and as researchers we must focus on identifying gelators capable of gelling classes of solvents as there is likely no one gelator capable of gelling all solvents.
The paper focuses on variable-rotor-speed/variable-blade-pitch wind turbines operating in the region of high wind speeds, where control is aimed at limiting the turbine energy capture to the rated ...power value. A robust sliding mode approach is proposed, using the blade pitch as control input, in order to regulate the rotor speed to a fixed rated value, in the presence of uncertainties characterizing the wind turbine model. Closed loop convergence of the overall control system is proved. The proposed control solution has been validated on a 5−MW three-blade wind turbine using the National Renewable Energy Laboratory (NREL) wind turbine simulator FAST (Fatigue, Aerodynamics, Structures, and Turbulence) code. A comparison with the standard FAST baseline controller (NWTC 2012 and Jonkman et al. 2009) has been also included.
Accident-tolerant fuel (ATF) cladding materials have been a focus of recent work to provide a greater resistance to fuel degradation, oxidation, and melting in light water reactors for beyond-design ...accident scenarios such as a station blackout (SBO). In a previous study, researchers at The University of Wisconsin-Madison used the Surry Nuclear Plant as the pilot plant to examine the effect of ATF substitute clad materials with the short-term SBO as the postulated accident, examining the effect of a loss of auxiliary feedwater (AFW) with the MELCOR systems code. In this work, we examine the effect of recovery actions for an SBO in Surry as a follow-on topic. Specifically, we selected two kinds of core cladding materials (Zircaloy and FeCrAl), and then conducted comparative analysis of the effect of water injection; first with a delay in water injection start times into the reactor pressure vessel (RPV) and then with steam generator (SG) steam-side AFW end times. We find that alternative cladding materials (FeCrAl) can effectively delay fuel degradation and system failures for both water injection strategies. One finds that RPV water injection can prevent such severe accident effects if restored in a few hours into the SBO. Conversely, SG steam-side AFW flow with alternative cladding materials (FeCrAl) can delay the fuel degradation and system failure processes by hours. We mainly focus on analyzing the severe accident progression by different quantitative signals, such as the onset of rapid hydrogen production, hot-leg creep rupture failure, and core slump. Analyses are now underway to consider the effects of proposed coating materials on Zircaloy cladding and if such coatings can afford similar benefits.
Pure cyclic diamino acids (CdAA) gel differently than combinations of CdAAs, altering the gelation behavior to highly-branched colloidal protein crystal networks reminiscent of traditional fat ...crystal networks in canola oil, making it an exciting structuring agent for unsaturated oils.
Cyclizing two amino acids (CDAs)
via
condensation produces molecular gelators in numerous solvents, while mixtures of four or more non-gelling CDAs solidify canola oil after heating and cooling with altered microstructures from individual CDAs.
A data-driven controller is presented in this paper, which stems from the well known model-free adaptive control approach based on an equivalent linearized dynamical model of the plant. Inspired by ...the recent paper (Liu and Yang, 2019), the output tracking problem is here solved by a data-driven adaptive sliding-mode controller simultaneously ensuring prescribed performance constraints. To allow a rigorous stability analysis, the sliding variable, and the consequently derived controller, have been redesigned with respect to the inspiring paper. A proper setting of the gain of the discontinuous term is shown necessary to ensure closed loop stability. Validation of the technique has been extensively performed on the well assessed high-fidelity tool FAST (NREL) to solve the efficiency maximization problem using the proposed approach for a 5 MW wind turbine operating in the medium wind speed region.
•The control law belongs to the approach called Model Free Adaptive Control (MFAC).•Coupling MFAC and Prescribed Performance Control improves controller performances.•The control law is applied to the energy transfer maximization in a Wind Turbine.•The controller performances are validated by the well known simulation tool FAST.•Features of the proposed Data Driven Controller make it be of interest by industry.
The influence of several nonionic surfactants (Tween-20, Tween-40, Tween-60, Span-20, Span-60, or Span-80) and anionic surfactants (sodium lauryl sulfate, sodium stearoyl lactylate, and sodium ...stearyl fumarate) showed drastic differences in the rank order of lipase activity/lipid bioaccessibility. The biophysical composition of the oil and water interface has a clear impact on the bioaccessibility of fatty acids (FA) by altering the interactions of lipase at the oil–water interface. It was found that the bioaccessibility was positively correlated with the hydrophilic/lipophilic balance (HLB) of the surfactant and inversely correlated to the surfactant aliphatic chain length. Furthermore, the induction time in the jejunum increased as the HLB value increased and decreased with increasing aliphatic chain length. The rate of lipolysis slowed in the jejunum with increasing HLB and with increasing aliphatic chain length.
Changes in the physical states, induced with different sous vide cooking temperatures, significantly (P < 0.05) altered lipid bioaccessibility measured in the TNO-simulated gastrointestinal tract ...model-1 of AAA boneless beef striploin, containing the longissimus lumborum muscle. The denaturation of actin significantly correlates with the total cumulative free fatty acid (FFA) bioaccessibility, whereby the striploin cooked to 60 °C presents the maximum lipid bioaccessibility (15.8 ± 1.0%), rate constant (k a) for FFA hydrolysis (0.087 ± 0.003 min–1), and greatest actin denaturation enthalpy (−0.57 ± 0.06 ΔH). Thus, thermal treatments above 60 °C significantly decrease the kinetics of lipolysis (70 °C = 0.042 ± 0.002 min–1 and 80 °C = 0.047 ± 0.002 min–1) and the resultant total lipid bioaccessibility (70 °C = 8.6 ± 0.7 and 80 °C = 8.3 ± 0.5%). This research highlights the potential to manipulate the physical food structure to alter digestion kinetics, supporting the need to understand supramolecular structures in food and their nutritional outcomes.
Systematic measurements of the annihilation cross sections of low energy antinucleons were performed at CERN in the 80's and 90's. However the antiproton data on medium-heavy and heavy nuclear ...targets are scarce. The ASACUSA Collaboration at CERN has measured the antiproton annihilation cross section on carbon at 5.3 MeV: the value is (1.73 ± 0.25) barn. The result is compared with the antineutron experimental data and with the theoretical previsions.
•Compositionally identical emulsions digest differently depending on their solid fat content.•As solid fat content increases, lipid bioaccessibility decreases in oil–water emulsions.•Overall, food ...structure can be a significant nutrient release factor in emulsions.
10 wt% oil-in-water emulsions with varied palm olein and stearin PO:PS ratios stabilized with 0.8 wt% Tween80 and tempered to obtain partially crystalline (CR) droplets (cooled from 80 to 4 °C and held overnight to induce nucleation/crystallization) or undercooled liquid (UC) droplets (cooled from 80 °C to 37 °C) produced emulsions with constant droplet size and polymorphism. However, zeta-potential decreased in undercooled emulsions due to crystallization/orientation of interfacial Tween, increasing alignment and ultimately a greater dipole moment. Significant differences in overall bioaccessibility between PO and PS present for the CR (PO bioaccessible fraction was 91%, whereas PS was 60%) and UC emulsions (PO and PS bioaccessibility were 96% and 77%).When only the solid fat content differs, and all other physical attributes remain constant, lipid digestibility decreases with increasing solid fat content; these findings, along with others, can be employed during food formulation and design more healthful foods.
Molecular rotors may be utilized as non-invasive, non-disruptive and highly sensitive alternatives to conventional measures of bulk viscosity when the oil is entrained in a colloidal fat crystal ...network. Oil viscosity changes based on the molecular confinement of the oil, which is dependent on its molecular volume. Changes in micro-viscosity were not dependent on the solids content, but instead were strongly dependent on the box-counting fractal dimension in high-space filling colloidal fat crystal networks (
i.e.
,
D
> 1.89). A bulk oil viscosity is often an overestimation of the actual viscosity of the entrained oil and may not be appropriate when predicting diffusion in multi-phase materials.
Micro-viscosity of confined oil is not dependent on the solids content, but is dependent on the box-counting fractal dimension in high-space filling colloidal fat crystal networks.
