5,036 research outputs found
How international is IEJME?
International Electronic Journal of Mathematics Education (IEJME) is an international journal that has been serving the mathematics education community for the last six years. We at times get a variety of feedback from our readers and authors. Some of these feedback are really positive which motivate us to do more in improving the quality of IEJME, whereas some of the criticism that we get are negative which are also helpful to keep us in the right path. This Editorial is about the kind of feedback and where it puts us in the international arena
Reflections on the continuing efforts on restructuring of IEJME
nternational Electronic Journal of Mathematics Education (IEJME) as an international journal has been gaining higher prominence in the international community of mathematics educators since the new structure has been in effect. We will briefly reflect on the changes we made in IEJME in this editorial. We receive an increasing number of submissions every month and our acceptance rate is 11% for the past one year. To better address the needs of the authors and reviewers we are in the process of adopting a new online submission system, which we believe will help us inform the authors in a timely manner and enable the authors and the reviewers to track the progress of the articles submitted or waiting to be reviewed in a more organized way. For journal editors, handling the review process is a challenging task that includes assigning appropriate reviewers for the submissions and providing timely, fair and informative reviews (Alacaci, 2010; Zembat, Alacaci, Argun, 2010). Our new online submission and tracking system will foster this practice in a more timely and organized way
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Armed violence and poverty in Nigeria: a mini case study for the Armed Violence and Poverty Initiative
YesThis mini report on Nigeria is one of 13 case studies (all of the case studies can be found at www/bradford.ac.uk/cics). This research draws upon research studies, reports and evaluations commissioned by operational agencies, and survey data where this has been available. These sources have been complemented by interviews with government officers, aid policymakers and practitioners, and researchers. The analysis and opinions expressed in this report are those of the authors and do not necessarily represent the views or policy of DFID or the UK government
Modelling the Effects of Friction on Tool-Chip Interface Temperature During Orthogonal Cutting of Al6061-T6 Aluminium Alloy
© IEOM Society International - IEOM 2019In this work, finite element simulations based on the analytical model derived with the MATLAB software were used to establish the temperature fields within the cutting tool and tool-chip interface. The average tool-chip interface temperature model was simulated and the simulation results were compared with experimental results for validation. At a maximum cutting speed of 90 m/min, the maximum temperature obtained from the experiment was 410 oC, at same rake angle of 0o. However, the developed model predicted 490 oC under the same conditions. The higher value obtained by the model can be attributed to the negligence of heat losses to the surrounding by both convection and radiation modes, as an assumption in the formulated model. A similar trend of these results was also recorded for the case of rake angle and feed rate of 30o and 0.0635 mm/rev, respectively. It was observed that the simulation results and experimental measurements for the average tool-chip interface temperature agreed significantly.Final Published versio
Experimental and numerical prediction of extrusion load at different lubricating conditions of aluminium 6063 alloy in backward cup extrusion
In the present research work using a backward cup extrusion (BCE) die profile, different lubricating conditions on aluminum alloy AA6063 have been experimentally and numerically investigated to predict the extrusion load. It was obvious that due to an increase in applications of the extrusion process, many researchers have worked on the extrusion process using different methods to achieve their aims. This experiment was conducted with three different lubricants namely: Castor oil, Palm Oil and tropical coconut oil; as well as without lubricants. Different lubricating conditions were employed of varying strain rates ranges from 1.5Ă10-3s-1, 2.0Ă10-3s-1, 2.5Ă10-3s-1, and 3.0Ă10-3s-1; Numerical analysis and simulation for dry and lubricated conditions during extrusion load were also performed using DEFORM 3D software. The results show that prediction extrusion load increases with increasing strain rates. The maximum extrusion load was found to be higher for extrusion without lubricants. In all cases of strain rate, palm oil showed a lower extrusion load compared to the other lubricants. Castor oil indicated the highest extrusion load when the experiment was carried out using lubrication. There was a consistent agreement between the result gotten from the experiment and simulation results of the extrusion load-strike curve.Peer reviewedFinal Published versio
Experimental and numerical investigations of free convection heat transfer in solar oven
The use of solar energy for baking, heating or drying represents a sustainable way of solar energy
applications with negligible negative effects. Solar oven is an alternative to conventional oven that rely
heavily on coal and wood or Electric oven that uses the power from the National grid of which the end
users have little or no control. Since the Solar oven uses no fuel and it cost nothing to run, it use are
widely promoted especially in situations where minimum fuel consumption or fire risks are considered
highly important. As useful as the Solar Oven proved, it major setback in the area of applications has
been its future sustainability. For the use of Solar Oven/Cookers to be sustained in the future, the design
and development of solar oven must rely on sound analytical tools. Therefore, this work focused on the
design and development of the solar oven. To test the performance of the Small Solar Oven a 5000cm3
beaker of water was put into the Oven and the temperature of the water was found to reach 810C after
about 3hrs under an average ambient temperature of 300C. On no load test, the oven reached a
maximum temperature of 112oC in 6hrs. In order to carry out the parametric studies and improve the
performance of the Solar Oven, Mathematical models were developed and solved by using
Characteristics-Based Split (CBS) Finite Element Method. The Model results were compared with the
Experimental results and a good agreement ware found between the two results
Effect of frictional boundary conditions and percentage area reduction on the extrusion pressure of Aluminum AA6063 alloy using FE analysis modelling
© 2020 by the authors; licensee Growing Science, Canada. This is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC-BY) license (http://creativecommons.org/licenses/by/4.0/).Finite Element Analysis was carried out to describe the effect of frictional boundary conditions and percentage reduction on deformation modelling (forward extrusion) of Aluminum AA6063 alloy. Curved die profiles of regular polygons (square, hexagonal, heptagonal, and octagonal) were designed using MATLAB R2009b and Autodesk Inventor 2013 to generate the coordinate and thesolid CAD model of the die profile respectively form a circular billet. The numerical analysis was performed using DeformTM-3D commercial package with frictional boundary conditions of 0.38 and 0.75 representing the wet and dry condition and varying the percentage reduction of 50%, 70%, and 90%. The results of the temperature distribution, effective stress, effective strain, andstrain rate were reported. As the percentage area reduction increases, the extrusion pressure also increases with an increasing frictional condition, and die length. Also, extrusion pressure decreases when the side of the polygon increases from square-shaped section follow by hexagonal shaped-section and least in octagonal shaped-section for both friction factors and percentage areareductions. For a given percentage reduction and cross-sectional area, there is no distinct difference between the predictive loads for the shaped-polygons. When the result of this analysis is compared with the experimental results from the literature, it is evident that DeformTM-3D is an effective tool for finite element analysis of non-isothermal deformation processes.Peer reviewedFinal Published versio
Development and performance evaluation of a natural draft mixed-type solar dryer for agricultural products
Reduced moisture content enhances storage properties of agricultural products and reduces post-harvest losses. Effective drying can be achieved using solar dryers in regions with abundant solar radiation. In this study, a natural draft mixed-type solar dryer suitable for rural communities of developing countries was developed. The performance of the solar dryer was also investigated using pepper, okra and tomato. The temperature taken at different points of the drying chamber and the auxiliary collector show that the temperature within the drying chamber is higher than the ambient temperature. The temperature within the drying chamber was also found to depend on the atmospheric conditions. The maximum drying rate was obtained at periods between 1200 and 1400 hrs Nigeria local time during which the temperature within the solar dryer is also maximum. Temperature within the solar dryer reached up to 62°C. The solar collector efficiency was 52.0% while the drying efficiency was 21.9%.Peer reviewe
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