Self-Similar Solutions to a Density-Dependent Reaction-Diffusion Model

In this paper, we investigated a density-dependent reaction-diffusion equation, $u_t = (u^{m})_{xx} + u - u^{m}$. This equation is known as the extension of the Fisher or Kolmogoroff-Petrovsky-Piscounoff equation which is widely used in the population dynamics, combustion theory and plasma physics. By employing the suitable transformation, this equation was mapped to the anomalous diffusion equation where the nonlinear reaction term was eliminated. Due to its simpler form, some exact self-similar solutions with the compact support have been obtained. The solutions, evolving from an initial state, converge to the usual traveling wave at a certain transition time. Hence, it is quite clear the connection between the self-similar solution and the traveling wave solution from these results. Moreover, the solutions were found in the manner that either propagates to the right or propagates to the left. Furthermore, the two solutions form a symmetric solution, expanding in both directions. The application on the spatiotemporal pattern formation in biological population has been mainly focused.Comment: 5 pages, 2 figures, accepted by Phys. Rev.

Final data types and their specification

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Integration factors of green skills into building construction trade programme in Nigeria

Technical and vocational education and training (TVET) remains a vital tool for skilling young individuals both in and out of school. However, it appears that there has been a lack of research especially in the building construction sector with respect to green buildings in Nigeria. The main purpose of this research paper is to identify factors should be included in the greening of building construction trade curriculum of technical colleges in north western Nigeria with a view to improving teaching and learning green skills for sustainable development. In this study, simple random sampling was used to select 15 building construction teachers in the north western Nigerian technical colleges. Data for this study were collected using qualitative approach (that is interview). Respondents were requested to answer the interview questions based on the topic under study. The factors (data) identified from the perception of the respondents were collected and analysed by qualitative means based on their level of consideration with regards to improving teaching and learning green skills for sustainable development. In doing so, the data were analysed by transcription, coding, content analysis and thematic with the aid of Nvivo statistical software. Findings indicated that the three main factors that could be included in the integration of green skills into the curriculum of building construction trade include environmental, economic and social factors. Specifically, these factors were disintegrated into climate change, global warming, greenhouse gas emission, economic instability, health and safety issues related to buildings, waste and energy in buildings. This research forms the initial investigation of a more in-depth study of the green skills integration into the Nigerian education curriculum, which aims to achieving environmental, economic and social sustainability

Ultrastructural anatomy of nodes of Ranvier in the peripheral nervous system as revealed by STED microscopy.

We used stimulated emission depletion (STED) superresolution microscopy to analyze the nanoscale organization of 12 glial and axonal proteins at the nodes of Ranvier of teased sciatic nerve fibers. Cytoskeletal proteins of the axon (betaIV spectrin, ankyrin G) exhibit a high degree of one-dimensional longitudinal order at nodal gaps. In contrast, axonal and glial nodal adhesion molecules [neurofascin-186, neuron glial-related cell adhesion molecule (NrCAM)] can arrange in a more complex, 2D hexagonal-like lattice but still feature a ∼190-nm periodicity. Such a lattice-like organization is also found for glial actin. Sodium and potassium channels exhibit a one-dimensional periodicity, with the Nav channels appearing to have a lower degree of organization. At paranodes, both axonal proteins (betaII spectrin, Caspr) and glial proteins (neurofascin-155, ankyrin B) form periodic quasi–one-dimensional arrangements, with a high degree of interdependence between the position of the axonal and the glial proteins. The results indicate the presence of mechanisms that finely align the cytoskeleton of the axon with the one of the Schwann cells, both at paranodal junctions (with myelin loops) and at nodal gaps (with microvilli). Taken together, our observations reveal the importance of the lateral organization of proteins at the nodes of Ranvier and pave the way for deeper investigations of the molecular ultrastructural mechanisms involved in action potential propagation, the formation of the nodes, axon–glia interactions, and demyelination diseases

RC Coupling Beams with High-Strength Steel Bars: Summary of Test Results

The use of high-strength steel bars in reinforced concrete coupling beams is expected to reduce reinforcement congestion. A series of tests was conducted to investigate the effects of high-strength reinforcement on coupling beam behavior. This report summarizes the test program and test results. Eleven large-scale coupling beam specimens were tested under fully reversed cyclic displacements of increasing magnitude. The main variables of the test program included: yield stress of the primary longitudinal reinforcement (Grade 80, Grade 100, and Grade 120 [550, 690, and 830]), span-to-depth (aspect) ratio (1.5, 2.5, and 3.5), and layout of the primary longitudinal reinforcement (diagonal [D] and parallel [P]). All beams had the same nominal concrete compressive strength (8,000 psi [55 MPa]) and cross-sectional dimensions (12 by 18 in. [305 by 457 mm]). Beams were designed for a target shear strength based on the upper limits specified in ACI 318-14. All transverse reinforcement was Grade 80 (550), except one specimen that had Grade 120 (830) transverse reinforcement. The test program is documented by presenting the details of specimen construction, test setup, instrumentation, and loading protocol. Documentation of test results include material properties and cyclic force-deformation response.Charles Pankow FoundationConcrete Research CouncilConcrete Reinforcing Steel Institut

Quantum battery charging by non-equilibrium steady-state currents

We present an analysis of the availability and maximum extractable work of quantum batteries in the presence of charge and/or heat steady-state currents. Quantum batteries are modelled as non-interacting open quantum systems (mesoscopic systems) strongly coupled to two thermal and particle reservoirs within the framework of non-equilibrium Green's function theory in a steady-state regime. We found that the battery can be charged manifestly by a steady-state charge current compared to heat one, especially, in an off-resonant transport regime. It allows us to reliably access the performance of the quantum batteries in the high bias-charging regime.Comment: new Refs. adde

The impact of assessment techniques on the relationship between work-based learning and teamwork skills development

The purpose of this study was to investigate the mediating effect of assessment techniques on the relationship between work-based learning and teamwork skills development at technical colleges in Nigeria. The sample consists of 257 technical teachers. The CFA models were developed to obtain the Chi-square values, modification indices, and standardized estimates using AMOS. Structural Equation Modeling (SEM), employing AMOS version 22 was utilized to test the mediation effect and also the relationship between work-based learning and teamwork skills development among students of technical colleges. The findings of the study revealed that work-based learning has a direct significant negative relationship with teamwork skills development among students of technical colleges, while, it has a direct insignificant positive relationship with assessment techniques. However, when the mediation hypothesis was tested, the result indicates that assessment techniques have a significant positive indirect impact on teamwork skills development, that is, it fully mediates the relationship between work-based learning and teamwork skills development among students of technical colleges. This study implies to educators that there is a need to appropriately enforce the assessment techniques for effective development of teamwork skills among TVET students. It is therefore, confirmed that teamwork skills should be enhanced when work-based learning is used in collaboration with appropriate assessment techniques

Reinforced Concrete Coupling Beams with High-Strength Steel Bars

The use of high-strength steel bars in reinforced concrete coupling beams has the potential to reduce reinforcement congestion and support more efficient design and construction methods. A series of tests was conducted to investigate the effects of high-strength reinforcement on coupling beam behavior. Eleven large-scale coupling beam specimens were tested under fully reversed cyclic displacements of increasing magnitude. The main variables of the test program included: yield stress of the primary longitudinal reinforcement (Grades 80, 100, and 120 [550, 690, and 830]), span-to-depth (aspect) ratio (1.5, 2.5, and 3.5), and layout of the primary longitudinal reinforcement (diagonal [D] and parallel [P]). All beams had the same nominal concrete compressive strength (8,000 psi [55 MPa]) and cross-sectional dimensions (12 by 18 in. [310 by 460 mm]). Beams were designed for target shear stresses of 8√f’c psi (0.67√f’c) for D-type beams and 6√f’c psi (0.5√f’c) for P- type beams. Transverse reinforcement was Grade 80 (550) in all but one beam, which had Grade 120 (830) reinforcement. The test program is documented by presenting the details of specimen construction, test setup, instrumentation, and loading protocol. Documentation of test data includes material properties, cyclic force-deformation response, progression of damage, calculated and measured strengths, initial stiffness, and measured reinforcement strains. Analysis of test data includes hysteretic energy, changes in beam length and depth, components of chord rotation, and the development of an equation for estimating chord rotation capacity.Charles Pankow FoundationACI Foundation’s Concrete Research CouncilConcrete Reinforcing Steel Institut