Algebraic identification of the first two natural frequencies of flexible-beam-like structures

The residual vibrations of highly resonant flexible structures can be usually composed of sinusoidal signals. The identification of the frequencies, amplitudes and/or phases of these sinusoidal signals may be of interest for health monitoring or to update controller parameters in active vibration control systems. This work considers a previously developed algebraic estimator of the frequencies, amplitudes and phases of two sinusoidal signals in order to identify the first two natural frequencies of flexible-beam-like structures. The influence of the unconsidered vibration modes on the estimation accuracy is studied by simulating a residual vibration formed by four sinusoidal components. It has been shown that the velocity and accuracy in the estimation of the first two natural frequencies depend on the distance between frequencies and the amplitudes of the first three vibration components. Finally, the beam parameters are related to the estimation performance.     

Methodology I’M IN applied to workshop: successful educational practice for consultants in user experience with gamification fields

Universal Access in the Information Society - The article is based on the development of a new methodology that promotes and contributes to a workshop, incorporating user experience as an...     

Evaluation of antioxidant, rheological and sensorial properties of wheat flour dough and bread containing ginger powder

The effects of addition of ginger powder (0, 3, 4.5 and 6%) in formulation were examined in order to obtain an antioxidant-enriched bread with good physico chemical and sensorial properties. The rheological properties of doughs were evaluated using dynamic rheological measurements. Physical properties, total phenolics content (TPC- Folin-Ciocalteau method), radical scavenging activity (RSA- DPPH assay) and sensory analysis (hedonic test) of the supplemented bread were determined.The highest TPC (0.48 and 0.71 mg GAE/g DW on crumb and crust respectively) and RSA activity (0.15 and 0.24 μmol DPPH/mg DW ml⁻¹ on crumb and crust respectively) were achieved in the bread having the highest percentage of ginger powder (6%). But this sample showed the worst results regarding the rheological properties indicating that the dough and the bread had a tough structure. Moreover, by sensory evaluation this bread sample was not acceptable.Among the studied samples, bread with 3% of ginger powder showed good rheological characteristics and doubled anti-oxidant content compared to the control bread and the highest sensorial acceptability.     

Estimation of beer stability by sulphur dioxide and polyphenol determination. Evaluation of a Laccase-Sonogel-Carbon biosensor

The traditional methods used to evaluate parameters related to beer ageing have been tested, revised and criticised. With this aim, a sampling of lager beers has been carried out. Sulphur dioxide, polyphenols and antioxidant capacity have been determined in fresh and aged beer. Only sulphur dioxide concentration showed relevant differences after the ageing process. These results together with a correlation study provided information about the selectivity of the methodologies used and have made it clear that sulphur dioxide has an important role and polyphenols have an indirect role. Laccase-Sonogel-Carbon biosensor is proposed to determine polyphenols in beers instead of Folin–Ciocalteu assay due to its better selectivity, sensitivity and short assay times.     

Assessing methods for predicting green roof rainfall capture: A comparison between full-scale observations and four hydrologic models

To optimize the application of green roof technology, there is a need to quantify stormwater mitigation in advance of green roof construction. This study contributes toward meeting this need by assessing the utility of four hydrologic models for predicting green roof rainfall capture, including the: (1) curve number method, (2) characteristic runoff equation, (3) Hydrological Evaluation of Landfill Performance (HELP V3.9D) model, and (4) Storm Water Management Model (SWMM V5.1). Modeling results were compared to over twenty-four months of observed runoff data, collected between June 2011 and December 2013, from two full-scale green roofs in New York City (NYC). Both the curve number method and characteristic runoff equation had the highest Nash-Sutcliffe efficiency index (NSEI) between modeled and observed cumulative runoff depth per event (NSEI = 0.97) due to parameter calibration requirements, where error was mainly due to variations in green roof antecedent moisture conditions. The HELP model was originally intended for evaluation of a continuous landfill cover. As a result, HELP's inability to account for the non-vegetated areas on green roofs caused underestimation of runoff depth for most events (NSEI = 0.84). Alternatively, the SWMM model tended to overestimate event runoff depth (NSEI = 0.94), thought to be the result of its storage term parameterization. Model assessments point to the need for more robust parameter estimation methods, particularly for inputs that are statistical or difficult to measure directly, to improve pre-development accuracy of green roof performance models.     

MnS Precipitation Behavior in Re‐Sulfurized Steels with Intermediate Levels of Sulfur

This paper presents results on the quantification of MnS precipitation during solidification of steels with intermediate levels of sulfur (0.05%) using a Confocal Scanning Laser Microscope (CSLM) equipped with a gold image furnace. The precipitation of MnS was observed in the liquid pools remaining in between advancing dendrites at the end of solidification. It was observed that MnS precipitated during cooling on existing mixed‐oxide particles of AI, Si and Ca. The rate of precipitation was seen to accelerate at two distinct points, once when the steel was molten and once during solidification.     

Exploring the Ability of Cyclic Peptides to Target SAM Domains: A Computational and Experimental Study

Sterile alpha motif (SAM) domains are protein interaction modules with a helical fold. SAM–SAM interactions often adopt the mid-loop (ML)/end-helix (EH) model, in which the C-terminal helix and adjacent loops of one SAM unit (EH site) bind the central regions of another SAM domain (ML site). Herein, an original strategy to attack SAM–SAM associations is reported. It relies on the design of cyclic peptides that target a region of the SAM domain positioned at the bottom side of the EH interface, which is thought to be important for the formation of a SAM–SAM complex. This strategy has been preliminarily tested by using a model system of heterotypic SAM–SAM interactions involving the erythropoietin-producing hepatoma kinase A2 (EphA2) receptor and implementing a multidisciplinary plan made up of computational docking studies, experimental interaction assays (by NMR spectroscopy and surface plasmon resonance techniques) and conformational analysis (by NMR spectroscopy and circular dichroism). This work further highlights how only a specific balance between flexibility and rigidity may be needed to generate modulators of SAM–SAM interactions.