THE ROLE OF FAMILY ENVIRONMENT IN DISTANCE LEARNING

This paper aims to discuss the role of family environment in distance learning. It presents the research conducted regarding parents’ views on distance learning, the way they experience it, the obstacles and the assets that are associated with distance learning. School-family collaborative relations are regarded crucial in enhancing students’ learning experience. Parents can contribute to their children’s learning by cultivating a positive relationship with their children, providing advice and guidance, organizing time, recording, and encouraging participation (motivation), teaching with the aim of supporting children. Parents can also supervise the completion of tasks and seek help when needed, time management, identifying students' needs, communication, and access to useful resources. It is important that parents understand the essential role that children play online. Parents need to be trained to organize their children's time, motivate students, and provide them with learning support when needed and make sure their child is learning. Finally, recommendations are presented about supporting students’ online learning by their parents.  Article visualizations

Direct Numerical Simulation of Complex Fuel Combustion with Detailed Chemistry: Physical Insight and Mean Reaction Rate Modeling

Direct numerical simulation of freely-propagating premixed flames of a multicomponent fuel is performed using a skeletal chemical mechanism with 49 reactions and 15 species. The fuel consists of CO,H2,H2O,CH4 and CO2 in proportions akin to blast furnace gas or a low calorific value syngas. The simulations include low and high turbulence levels to elucidate the effect of turbulence on realistic chemistry flames. The multi-component fuel flame is found to have a more complex structure than most common flames, with individual species reaction zones not necessarily overlapping with each other and with a wide heat releasing zone. The species mass fractions and heat release rate show significant scatter, with their conditional average however remaining close to the laminar flame result. Probability density functions of displacement speed, stretch rate, and curvature are near-Gaussian. Five different mean reaction rate closures are evaluated in the RANS context using these DNS data, presenting perhaps the most stringent test to date of the combustion models. Significant quantitative differences are observed in the performance of the models tested, especially for the higher turbulence level case.ZMN and NS acknowledges the funding through the Low Carbon Energy University Alliance Programme supported by Tsinghua University, China. ZMN and NS also acknowledge Prof. S. Cant for the DNS code. ZMN acknowledges the educational grant through the A.G. Leventis Foundation. This work made use of the facilities of HECToR, the UK’s national high performance computing service, which is provided by UoE HPCx Ltd at the University of Edinburgh, Cray Inc and NAG Ltd, and funded by the Office of Science and Technology through EPSRC’s High End Computing Programme. EPSRC support is acknowledged.This is the final version of the article. It first appeared from Taylor & Francis via http://dx.doi.org/10.1080/00102202.2015.106491

Critical Scaling Properties at the Superfluid Transition of 4^4He in Aerogel

We study the superfluid transition of $^4$He in aerogel by Monte Carlo simulations and finite size scaling analysis. Aerogel is a highly porous silica glass, which we model by a diffusion limited cluster aggregation model. The superfluid is modeled by a three dimensional XY model, with excluded bonds to sites on the aerogel cluster. We obtain the correlation length exponent $\nu=0.73 \pm 0.02$, in reasonable agreement with experiments and with previous simulations. For the heat capacity exponent $\alpha$, both experiments and previous simulations suggest deviations from the Josephson hyperscaling relation $\alpha=2-d\nu$. In contrast, our Monte Carlo results support hyperscaling with $\alpha= -0.2\pm 0.05$. We suggest a reinterpretation of previous experiments, which avoids scaling violations and is consistent with our simulation results.Comment: 4 pages, 3 figure

Heat release rate markers for premixed combustion

The validity of the commonly used flame marker for heat release rate (HRR) visualization, namely the rate of the reaction OH + CH2O ⇔ HCO + H2O is re-examined. This is done both for methane–air and multi-component fuel–air mixtures for lean and stoichiometric conditions. Two different methods are used to identify HRR correlations, and it is found that HRR correlations vary strongly with stoichiometry. For the methane mixture there exist alternative HRR markers, while for the multi-component fuel flame the above correlation is found to be inadequate. Alternative markers for the HRR visualization are thus proposed and their performance under turbulent conditions is evaluated using DNS data.ZMN and NS acknowledges the funding through the Low Carbon Energy University Alliance Programme supported by Tsinghua University, China. ZMN also likes to acknowledge the educational grant through the A.G. Leventis Foundation. This work made use of the facilities of HECToR, the UK’s national high-performance computing service, which is provided by UoE HPCx Ltd at the University of Edinburgh, Cray Inc. and NAG Ltd., and funded by the Office of Science and Technology through EPSRC’s High End Computing Programme.This is the final published version. It first appeared at: http://www.sciencedirect.com/science/article/pii/S0010218014001606#

Does treating the permanent workforce well matter to temporary employees?

The article focuses on a study by Bard Kuvaas and Anders Dysvik testing their hypothesis that the development opportunities for permanent employees affect how temporary employees view their positions, their job behavior, and their social exchange relationship with the organization. The authors note that Kuvaas and Dysvik employ a social information processing perspective in which the social climate of an organization is a factor. The authors report that this hypothesis was validated in Kuvaas and Dysvik's survey of 375 temporary employees

Inferring Causal Direction from Observational Data: A Complexity Approach

At the heart of causal structure learning from observational data lies a deceivingly simple question: given two statistically dependent random variables, which one has a causal effect on the other? This is impossible to answer using statistical dependence testing alone and requires that we make additional assumptions. We propose several fast and simple criteria for distinguishing cause and effect in pairs of discrete or continuous random variables. The intuition behind them is that predicting the effect variable using the cause variable should be ‘simpler’ than the reverse – different notions of ‘simplicity’ giving rise to different criteria. We demonstrate the accuracy of the criteria on synthetic data generated under a broad family of causal mechanisms and types of noise

Communication and Collaboration between School and Family for Addressing Bullying

School and family are the main socializing agents for children. Therefore, effective communication and collaboration between these contexts is essential, although sometimes there are barriers to school-family partnership, particularly when they try to play a more active role in the educational process. It is widely recognized that parent involvement in school has successful contributions to student school outcomes. Moreover, It is crucial for addressing effectively bullying, as it is a problem student behaviour in Greek society as well.In this context, the present research aims to explore teachers' views about family-school communication and collaboration regarding the extent to which they address effectively bullying. 150 primary education teachers from public schools in Rhodes participated in this research, which conducted in 2015. Results show that teachers endorse the importance of school-family collaboration for addressing bullying. In addition, they consider this collaboration important, as it has an important influence on children's attitudes to school, and their behaviour in school environment. Furthermore, they suggest that school-family collaboration may improve students' social skills, which can enhance their emotional development and reduce their social isolation from the peer group. Finally, they assert that school-family collaboration can empower children's relationship with their parents and teachers, and in the long term it can contribute in enhancing their school achievement

A 5-step reduced mechanism for combustion of CO/H 2/H 2O/CH 4/CO 2 mixtures with low hydrogen/methane and high H 2O content

In this study a 5-step reduced chemical kinetic mechanism involving 9 species is developed for combustion of Blast Furnace Gas (BFG), a multi-component fuel containing CO/H2/CH4/CO2, typically with low hydrogen, methane and high water fractions, for conditions relevant for stationary gas-turbine combustion. This reduced mechanism is obtained from a 49-reaction skeletal mechanism which is a modified subset of GRI Mech 3.0. These skeletal and reduced mechanisms are validated for laminar flame speeds, ignition delay times and flame structure with available experimental data, and using computational results with a comprehensive set of elementary reactions. Overall, both the skeletal and reduced mechanisms show a very good agreement over a wide range of pressure, reactant temperature and fuel mixture composition.ZMN and NS acknowledges the funding through the Low Carbon Energy University Alliance Programme supported by Tsinghua University, China. ZMN also likes to acknowledge the educational grant through the A.G. Leventis Foundation.This is the accepted manuscript. The final version's available from Elsevier at http://www.sciencedirect.com/science/article/pii/S0010218012002714

Evaluation of a reduced mechanism for turbulent premixed combustion

In this study, 3D direct numerical simulations of a multi-component fuel consisting of CO,H2,H2O,CO2 and CH4 reacting with air are performed. A freely propagating turbulent premixed stoichiometric flame is simulated for both low and high turbulence conditions i.e., the rms values of turbulent velocity fluctuations normalised by the laminar flame speed are of order 1 and 10. A skeletal mechanism involving 49 reactions and 15 species, and a 5-step reduced mechanism with 9 species, are used in order to evaluate the performance of the reduced mechanism under turbulent conditions. The 5-step mechanism incurs significantly lower computational expenses compared to the skeletal mechanism. The majority of species mean mass fractions and mean reaction rates computed using these two mechanisms are in good agreement with one another. The mean progress variable and heat release rate variations across the flame brush are also recovered by the reduced mechanism. No major differences are observed in flame response to curvature or strain effects induced by turbulence, although some differences are observed in instantaneous flame structure. These differences are studied using a correlation coefficient and detailed analysis suggests that this comes from the fluctuating heat release induced effects in the case with higher turbulence level. Further considerations based on instantaneous reaction rate and local displacement speed are discussed to evaluate the suitability of the reduced mechanism.Z.M.N. and N.S. acknowledges the funding through the Low Carbon Energy University Alliance Programme supported by Tsinghua University, China. Z.M.N. and N.S. acknowledge Prof. R.S. Cant for use of his DNS code SENGA2 which made these simulations possible. Z.M.N. acknowledges the educational grant through the A.G. Leventis Foundation. This work made use of the facilities of HECToR, the UK’s national high-performance computing service, which is provided by UoE HPCx Ltd at the University of Edinburgh, Cray Inc and NAG Ltd, and funded by the Office of Science and Technology through EPSRC’s High End Computing Programme.This is the published version. It first appeared at http://www.sciencedirect.com/science/article/pii/S0010218014001916#