Volume 07 Issue 01
Investigating Effect of Active Learning Activities through Pre and Post Activity Questionnaires and Student Feedback Surveys
Maher Shehadi | pp: 01-10 | Download Paper | Show Abstract
Abstract: Many courses have been traditionally taught in a conventional way following lecture based techniques with minimal hands-on and interactive activities that involve the students in the learning process. Due to raising market demands, employers are seeking graduates with higher logical thinking level skills, team work skills and leadership, complex problem solving and communication capabilities. This necessitates using more student-centered approaches rather than instructor-based focused learning approaches where students are more engaged in the learning environment in class. A set of activities were applied in Applied Fluid Mechanics course to flip it into a more interactive environment class. The activities were graded based on the instructor observations and students’ scores in each activity. The effectiveness of the activities in the proposed course was analyzed using students’ feedback through post-activity surveys, students’ scores and using pre- and post-activity questionnaires. The study compared the results for three years when the activities were applied against scores when no activities were applied. Based on the overall course grades, students’ performance has improved from one year to another. The individual questionnaires showed different improvement levels ranging from 4-75% based on scores in pre-and post-questionnaires. Many other skills showed improvements from the students’ perspective in the surveys. The outcomes of the applied activities can help in meeting ABET learning outcomes and course learning outcomes set by the department such as applying engineering knowledge, critical and logical thinking, complex problem solving, communication skills, team work skills in addition to improving students’ learning in an interactive learning environment.
Reliability Prediction Model Patterns for Neem Leaf Phytochemicals at Varying Temperature
Orlando Ketebu, Yousuo Digieneni, Owologba Gladys Ome | pp: 11-19 | Download Paper | Show Abstract
Abstract: Neem leaf extract phytochemicals are known for their biochemical and medicinal purposes in treating sickness and diseases. The model patterns with which the phytochemicals (alkaloids, flavonoids, saponins, tannins, and terpernoids) changes with temperature is of importance because there are no model relationships to show how this phytochemicals changes with temperature and their efficacy and activities depends on temperature. This paper predicts the relationship pattern of neem leaf extract phytochemicals at temperatures 25°C, 40°C, 60°C, 80°C and 100°C respectively. The experimental results showed that 25°C and 40°C had alkaloids, flavonoids, saponins and terpenoids at medium concentrations and tannins at high concentration and above 60°C they diminish. Alkaloids, tannins, saponins and terpenoids followed a second order polynomial model pattern with reliability prediction (R2) of 0.9964, 0.9971, 0.9949, and 0.9939 while flavonoids varied linearly with R2 of 0.9955 respectively. The pH and specific gravity of the neem leaf extract decreases with increasing temperature while conductivity increases, all in a second order polynomial form with R2 values of 0.9929, 0.9988 and 0.9969 respectively. The high values of reliability prediction showed that the model equations perfectly predict the changes taking place and can be used as a model for future scale up processes.
Effect of Boronizing on Erosive wears of Alloy Steel
G. Ebenezer, D. Chellaganesh, S. Sivakumar | pp: 20-24 | Download Paper | Show Abstract
Abstract: This study aims to Diffuse boron atoms into the alloy steel. The samples were Boronized using BORAX (Di sodium tetra borate) and Boron carbide as a Boron Source. The advantage of using the BORAX as potential source for boron is to avoid formation of fragile FeB phase over the surface. The Temperature and time for Boronizing was set at 1073 K and 1 Hr respectively. Erosive wear performed in Air Jet Erosion tester TR-470. The result exploited that the boronized samples show improved wear resistance than untreated samples. Mathematical model based on Third order polynomial equation was developed for erosive wear rate as a function of time. Atomic Force Microscopy (AFM) image confirms diffusion of Boron over the steel surface.
Fatigue Strength Analysis of Low Carbon Steel under Corrosive and Non Corrosive Environment
Nitin Alex Vaidyan, M. Unnikrishnan, K. S. Sajikumar | pp: 25-29 | Download Paper | Show Abstract
Abstract: Failure due to cyclic loads in corrosive atmosphere is important in mining equipment’s, underwater pipeline, aerospace components and much more. Low carbon steel is selected as the material. An experimental study is provided on the impact of salinity and time reliance on corrosion fatigue life. The fatigue corrosion testing is done by varying the concentration of saline environment. The Immersion time testing is done under 3.5% NaCl Aqueous solution with different Pre-corrosion times. For both tests the numbers of cycles to failure were observed around 104 cycles. Testing is done under constant amplitude by applying desired force in axial testing samples. The test environments were in-situ corrosive environment with 0 %, 0.7%, 1.4%, 2.1%, 2.8% and 3.5 % NaCl aqueous solution concentrations. The pre-corrosion time period of Immersion test was 1, 2, 4, 7, 14, 21 and 30 days. The research seeks to understand how the salinity of corrosive medium and pre-corrosion duration impacts the fatigue life and premature failure of the selected material.