Shedding Light on Student Learning Through the Use of Lightboard Videos

This mixed-method study examined the effect of Lightboard videos on student learning and perceptions in a Flipped Classroom Model (FCM). The study targeted 68 civil engineering undergraduate students at a 4-year public university in Southeastern USA. Lightboard videos were intentionally alternated between two consecutive semesters. Within the same section of the course, classes without Lightboard videos served as a control group and classes with Lightboard videos served as a study group. Both sections were taught by the same instructor utilizing the same materials and assessments for the class. Student academic performance was measured using in-class assignments. Additional quantitative and qualitative data were collected through an end-of-semester survey. Data show a modest academic performance increase on the overall score on in-class assignments and an improvement of average student scores on 69.2% of the in-class assignments in the study group. The overall means on the Likert scale survey showed a strong endorsement of Lightboard videos for understanding, engagement and satisfaction. Students commented positively on the collaborative aspect of in-class problem solving in FCM

Salicylaldehyde hydrazones: buttressing of outer sphere hydrogen-bonding and copper-extraction properties

Salicylaldehyde hydrazones are weaker copper extractants than their oxime derivatives, which are used in hydrometallurgical processes to recover ~20 % of the world’s copper. Their strength, based on the extraction equilibrium constant Ke, can be increased by nearly three orders of magnitude by incorporating electron-withdrawing or hydrogen-bond acceptor groups (X) ortho to the phenolic OH group of the salicylaldehyde unit. Density functional theory calculations suggest that the effects of the 3-X substituents arise from a combination of their influence on the acidity of the phenol in the pH-dependent equilibrium, Cu2+ + 2Lorg ⇌ [Cu(L–H)2]org + 2H+, and on their ability to ‘buttress’ interligand hydrogen bonding by interacting with the hydrazone N–H donor group. X-ray crystal structure determination and computed structures indicate that in both the solid state and the gas phase, coordinated hydrazone groups are less planar than coordinated oximes and this has an adverse effect on intramolecular hydrogen-bond formation to the neighbouring phenolate oxygen atoms

Incompressible smoothed particle hydrodynamics (SPH) with reduced temporal noise and generalised Fickian smoothing applied to body–water slam and efficient wave–body interaction

AbstractIncompressible smoothed particle hydrodynamics generally requires particle distribution smoothing to give stable and accurate simulations with noise-free pressures. The diffusion-based smoothing algorithm of Lind et al. (J. Comp. Phys. 231 (2012) 1499–1523) has proved effective for a range of impulsive flows and propagating waves. Here we apply this to body–water slam and wave–body impact problems and discover that temporal pressure noise can occur for these applications (while spatial noise is effectively eliminated). This is due to the free-surface treatment as a discontinuous boundary. Treating this as a continuous very thin boundary within the pressure solver is shown to effectively cure this problem. The particle smoothing algorithm is further generalised so that a non-dimensional diffusion coefficient is applied which suits a given time step and particle spacing.We model the particular problems of cylinder and wedge slam into still water. We also model wave-body impact by setting up undisturbed wave propagation within a periodic domain several wavelengths long and inserting the body. In this case, the loads become cyclic after one wave period and are in good agreement with experiment. This approach is more efficient than the conventional wave flume approach with a wavemaker which requires many wavelengths and a beach absorber.Results are accurate and virtually noise-free, spatially and temporally. Convergence is demonstrated. Although these test cases are two-dimensional with simple geometries, the approach is quite general and may be readily extended to three dimensions

Boussinesq modelling of tsunami and storm wave impact

Many coastal protection structures in the UK have been designed for storm surges with appropriate return periods, but their performance during tsunami-type waves is uncertain. A shallow water and Boussinesq model is well suited to the investigation of both near-shore storm waves and tsunami waves. This paper makes use of the model to compare the effect on coastal structures of solitary waves and storm waves. Wave run-up parameters for both types of wave are generated and shown to be in good agreement with experimental data. The equations behind the model were derived assuming a small bed slope and therefore are not suitable for modelling waves interacting with vertical and near-vertical structures. However, the introduction of a reverse momentum term, to take account of a jet of water typical of a breaking wave impacting against a structure, allows wave overtopping volumes to be well predicted, although it had a minor effect on the forces acting on the structure. Comparisons with experimental data, for both solitary waves and storm waves, are presented. Using this model, the difference between the impact, in terms of wave forces and wave overtopping, of tsunami waves and storm waves for a given structure is investigated. </jats:p

In search of flavour-nutrient learning:A study of the Samburu pastoralists of North-Central Kenya

Much of our dietary behaviour is learned. In particular, one suggestion is that ‘flavour-nutrient learning’ (F-NL) influences both choice and intake of food. F-NL occurs when an association forms between the orosensory properties of a food and its postingestive effects. Unfortunately, this process has been difficult to evaluate because F-NL is rarely observed in controlled studies of adult humans. One possibility is that we are disposed to F-NL. However, learning is compromised by exposure to a complex Western diet that includes a wide range of energy-dense foods. To test this idea we explored evidence for F-NL in a sample of semi-nomadic pastoralists who eat a very limited diet, and who are lean and food stressed. Our Samburu participants (N = 68) consumed a sensory-matched portion (400 g) of either a novel low (0.72 kcal/g) or higher (1.57 kcal/g) energy-dense semi-solid food on two training days, and an intermediate version on day 3. Before and after each meal we measured appetite and assessed expected satiation and liking for the test food. We found no evidence of F-NL. Nevertheless, self-reported measures were very consistent and, as anticipated, expected satiation increased as the test food became familiar (expectedsatiation drift). Surprisingly,we observed insensitivity to the effects of test-meal energy density on measures of post-meal appetite. To explore this further we repeated a single training day using participants (N = 52) from the UK. Unlike in the Samburu, the higher energy-dense meal caused greater suppression of appetite. These observations expose interesting cross-cultural differences in sensitivity to the energy content of food. More generally, our work illustrates how measures can be translated to assess different populations, highlighting the potential for further comparisons of this kind

Portion Size Influences Intake in Samburu Kenyan People Not Exposed to the Western Obesogenic Environment

For people in the modernized food environment, external factors like food variety, palatability, and ubiquitous learned cues for food availability can overcome internal, homeostatic signals to promote excess intake. Portion size is one such external cue; people typically consume more when served more, often without awareness. Though susceptibility to external cues may be attributed to the modernized, cue-saturated environment, there is little research on people living outside that context, or with distinctly different food norms. We studied a sample of Samburu people in rural Kenya who maintain a traditional, semi-nomadic pastoralist lifestyle, eat a very limited diet, and face chronic food insecurity. Participants (12 male, 12 female, aged 20–74, mean BMI = 18.4) attended the study on two days and were provided in counterbalanced order an individual serving bowl containing 1.4 or 2.3 kg of a familiar bean and maize stew. Amount consumed was recorded along with post-meal questions in their dialect about their awareness of intake amount. Data were omitted from two participants who consumed the entire portion in a session. Even though the ‘smaller’ serving was a very large meal, participants consumed 40% more when given the larger serving, despite being unable to reliably identify which day they consumed more food. This result in the Samburu demonstrates the portion size effect is not a by-product of the modern food environment and may represent a more fundamental feature of human dietary psychology

Fracture toughness of the cancellous bone of FNF femoral heads in relation to its microarchitecture

This study considers the relationship between microarchitecture and mechanical properties for cancellous bone specimens collected from a cohort of patients who had suffered fractured necks of femur. OP is an acute skeletal condition with huge socioeconomic impact [1] and it is associated with changes in both bone quantity and quality [2], which affect greatly the strength and toughness of the tissue [3].Support was provided by the EPSRC (EP/K020196: Point-ofCare High Accuracy Fracture Risk Prediction), the UK Department of Transport under the BOSCOS (Bone Scanning for Occupant Safety) project, and approved by Gloucester and Cheltenham NHS Trust hospitals under ethical consent (BOSCOS – Mr. Curwen CI REC ref 01/179G)

The loading on a vertical cylinder in steep and breaking waves on sheared currents using smoothed particle hydrodynamics

Waves and currents coexist in a wide range of natural locations for the deployment of offshore structures and devices. This combined wave–current environment largely determines the loading of vertical surface piercing cylinders, which are the foundations typically used for offshore wind turbines along with many other offshore structures. The smoothed particle hydrodynamics (SPH) code DualSPHysics is used to simulate focused waves on sheared currents and assess subsequent loading on a vertical cylinder. Outputs from another numerical model are used to define the SPH inlet–outlet boundary conditions to generate the wave–current combinations. A modified damping zone is used to damp the waves, but allow the currents to exit the domain. Numerical results are validated against experimental measurements for surface elevation and associated loading on the cylinder. Four phase repeats are used in the SPH model to understand the harmonic structure of the surface elevation at the front face of the cylinder and associated loading. It is shown that the SPH model provides agreement with experimental measurements of harmonic components for both force and elevations. Taking advantage of the SPH method, wave amplitudes were increased up to, and beyond, the breaking threshold highlighting a complex relationship between peak force and wave phase, requiring detailed investigation. The numerical modeling of interactions of steep and breaking waves on sheared currents with the cylinder demonstrates the SPH model's capability for modeling highly nonlinear fluid–structure interaction problems