Analytical assessment process of e-learning domain research between 1980 and 2014

Applying some methods to reduce the time and expenditures of training is inevitable in existing circumstances. Many educational organizations have realized the importance of Electronic Learning (E-learning) and tried to use this approach in leveraging their academic classes. As research in E-learning domain has become one of the most important and interesting subjects, observation in emerging and fading trends of E-learning is a need for the scholars and industry professionals who are interested to study and work in the field. This paper has triggered the investigation and depicting of scientific trends in E-learning by using two scientometric methods named burst detection and clustering analysis. By applying two mentioned methods, the hot topics were identified in the field of E-learning.info:eu-repo/semantics/acceptedVersio

Effect of Source Solution Components on Quality of Electrospun PVDF Nanofibers for Nanogenerator Application

High surface area flexible thin films of Polyvinylidene Difluoride (PVDF) nanofibers are vastly used because of low cost, simple, safety and environmentally friendly production methods. PVDF nanofibers are inherently piezoelectric when produced by high voltage electrospinning method. In this paper, PVDF nanofibers are synthesis in a electrospinning apparatus, using a solution that contains PVDF dissolved in two solvents, THF (Tetrahydroforan) and DMF (N,N-Di-Methyl Formamid), which DMF has a higher boiling point than THF. The effects of THF to DMF ratio in the solution, and also, PVDF concentration on the morphology and diameter of the synthesised nanofibers are studied. Field emission scanning electron microscopy analysis of the nanofiber thin films indicates that by adding THF in the source suspension, smoother and more uniform nanofibers with lower diameter are resulted. However, by further increasing THF ratio, the cone-jet mode is formed on the tip of the needle, rapidly dried, before reaching the collector substrate. Results of the further experiments indicate that decreasing of PVDF concentration in the deposition source solves the latter problem. On the other hand, by decreasing the THF ratio to DMF, the solution cannot completely be dried, before collecting by the substrate. The best and uniform nanofibers with the diameter of 200 to 300 nm are obtained from a ratio of 3:1 For THF:DMF and 10 % PVDF concentration. Fabricated nanogenerator, based on the best mentioned sample, shows an output power of 0.56 W/m2 when actuated by a vibration mechanical force with the frequency of 8 Hz

Experimental and numerical modelling of water waves in sewer networks during sewer/surface flow interaction using a coupled ODE-SWE solver

Flooding in urban areas is expected to increase its magnitude and frequency in the future. Therefore, there is a strong need to better model sewer–surface flow interactions. Existing numerical methods are commonly based on simplified representations of sewer/surface mass exchange, and mainly validated in steady flow conditions. Current methodologies describing the propagation of transient conditions/waves through interaction nodes are simplified, rely on empirical coefficients and/or lack detailed validation. In this paper, an integrated numerical approach for modelling the propagation of water waves through interaction nodes (e.g., manholes) is presented. In this solution, the shallow water equations are used to simulate the free-surface propagation inside the sewer network, and an ordinary differential equation is employed for modelling flow regimes through pipes and manholes. The model proposed is validated against the well-known STAR-CD modelling software for a number of test cases. Finally, further validation is performed against experimental data describing the evolution of water depth around a manhole in unsteady surcharging conditions

Could circRNA be a new biomarker for pre-eclampsia?

Pre-eclampsia is a devastating complication of pregnancy which is characterized by hypertension and proteinuria in pregnant women. Pre-eclampsia is important as it is the leading cause of death. Moreover, untreated pre-eclampsia might lead to other lethal complications, for both fetus and mother. Pre-eclampsia can also affect the quality of life in affected women. Despite a large number of risk factors for pre-eclampsia, these risk factors are able to detect just 30 of women who are susceptible to pre-eclampsia. Heterogeneous manifestations of pre-eclampsia necessitate the discovery of potential biomarkers required for its early detection. Circular RNAs (circRNAs) are a type of RNA which are more abundant, specific, and highly organized compared with other types of RNA. Accordingly, circRNAs have been suggested as one of the potential biomarkers for different diseases. Recently, researchers have shown interest in the effects of circRNAs in pre-eclampsia, although the current evidence is limited. The majority of obstetricians are probably not aware of circRNAs as a useful biomarker. Here, we aimed to summarize recent supporting evidence and assess the mechanisms by which circRNAs are involved in pre-eclampsia. © 2019 Wiley Periodicals, Inc

Two-dimensional turbulence in magnetised plasmas

In an inhomogeneous magnetised plasma the transport of energy and particles perpendicular to the magnetic field is in general mainly caused by quasi two-dimensional turbulent fluid mixing. The physics of turbulence and structure formation is of ubiquitous importance to every magnetically confined laboratory plasma for experimental or industrial application. Specifically, high temperature plasmas for fusion energy research are also dominated by the properties of this turbulent transport. Self-organisation of turbulent vortices to mesoscopic structures like zonal flows is related to the formation of transport barriers that can significantly enhance the confinement of a fusion plasma. This subject of great importance in research is rarely touched on in introductory plasma physics or continuum dynamics courses. Here a brief tutorial on 2D fluid and plasma turbulence is presented as an introduction to the field, appropriate for inclusion in undergraduate and graduate courses.Comment: This is an author-created, un-copyedited version of an article published in European Journal of Physics. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The definitive publisher authenticated version is available online at doi: 10.1088/0143-0807/29/5/00

The survey on aquaculture capacity of Ghar-Khatlo dam reservoir in Zanjan province

Qhar-khetlu dam reservoir is in the central part of Ijrud city of Zanjan province with a reservoir volume of 500000 and a water volume of 900000 cubic meters, covering an area of 6 hectares and containing 3500 hectares of the watershed in order to control seasonal floods, drinking water in the village, strengthening the aquifers of the area and As a water supply in the dry seasons, 120 hectares of agricultural land was planted for irrigation.Study of this water source with the aim of measuring biological and non-biological factors, determination of aquaculture production and Fish release capacity and fishing capacity for optimal use of fishery management in Zanjan province was done in 2006.The results of hydrochemical analysis of the water of Qharkhetlu dam reservoir showed that the minimum and maximum temperature of water ranged from 4.5 to 26 ° C, the pH of the water was 4.7 to 8.8, the dissolved oxygen was 7.7 to 12.2 mg, the total water hardness fluctuation was 154 194 mg/L and electrical conductivity of 272 to 390 micrometers per square centimeter, the water transparency was 25 to 380 centimeters.In this study, six phytoplankton classes with 31 genera and 3 classes of zooplankton with 14 genera were obtained. The abundance of phytoplanktons was counted from 150,000 to 206,000 per liter, and the average chlorophyll a, 1.10 micrograms, was estimated. The frequency of zooplanktons were 32 to 132 per liter, as well as the mean of 544 per square meter of macrobenthos.By comparing of the physical, chemical and biological factors and also the results of previous studies of this water source, the conditions for the introduction of warm water and cold water fishes including silver carp, big head carp, rainbow trout out and native fishes including species of Barbus and Capoeta genera are suitable. Estimation of Qhar-khetlu dam reservoir production is 80 kg/ha and its production capacity is 484 kg per year

Efficient numerical computation and experimental study of temporally long equilibrium scour development around abutment

YesFor the abutment bed scour to reach its equilibrium state, a long flow time is needed. Hence, the employment of usual strategy of simulating such scouring event using the 3D numerical model is very time consuming and less practical. In order to develop an applicable model to consider temporally long abutment scouring process, this study modifies the common approach of 2D shallow water equations (SWEs) model to account for the sediment transport and turbulence, and provides a realistic approach to simulate the long scouring process to reach the full scour equilibrium. Due to the high demand of the 2D SWEs numerical scheme performance to simulate the abutment bed scouring, a recently proposed surface gradient upwind method (SGUM) was also used to improve the simulation of the numerical source terms. The abutment scour experiments of this study were conducted using the facility of Hydraulics Laboratory at Nanyang Technological University, Singapore to compare with the presented 2D SGUM-SWEs model. Fifteen experiments were conducted over a total period of 3059.7 hours experimental time (over 4.2 months). The comparison shows that the 2D SGUM-SWEs model gives good representation to the experimental results with the practical advantage

E-learning: you don't always get what you hope for

Despite substantial growth in the use of information and communication technologies (ICT) throughout western societies, there is much evidence of technology-led innovations within Higher Education (HE) failing to achieve the anticipated transformations in learning and teaching. This paper reviews evidence from research and evaluation studies relating not only to e-learning, but also to wider HE practices. It argues that the use of ICT does not, in itself, result in improved educational outcomes and ways of working. It considers contextual factors that are of greater significance in determining how and why e-learning is used in HE. Students' engagement with e-learning relates to their expectations and conceptions of learning and to assessment demands. Academics need to re-assess their own beliefs and practices concerning teaching and assessment and their impact on the experience of learners. Both teachers and learners need to understand why e-learning activities are to be undertaken and the rewards expected to be derived