Science and Engineering Connect

Evaluation of DEG7-9 Design Heuristics by Applying Game Experience Questionnaire

Kornchulee Sungkaew — 2020-06-30

This research aimed to validate the effectiveness of the design heuristic procedure called "DEG7-9" in terms of game experience by using the game experience questionnaire called "THGEQ" to evaluate a digital educational game called "Waste Separation," which was designed for children age 7-9 following DEG7-9. Seventy-two students were randomized to play the game. Then, they were asked to indicate their feeling about the DEG by rating 7 statements covering the 7 dimensions of the game experience using the visual analogue scale. After the means for each of the THGEQ statements were computed, the differences in the level of perceptions related to three demographic variables (gender, education level, and age) were compared by the Kolmogorov-Smirnov Test and Mann-Whitney test. It was found that the means for the positive dimensions were moderate to highest, whereas the means for the negative dimensions were low. There were no significant differences in the perceptions of 6 dimensions between the groups of children; only exception was noted in the case of Immersion. THGEQ, which has been translated from KidsGEQ into a set of understandable and concise statements for Thai children, is therefore noted to be appropriate for identifying children’s perceptions of game experience. The game designed by following DEG7-9 could present a quality game experience. Both DEG7-9 and THGEQ heuristics are valuable tools to provide game design teams with an HCI-focused set of design heuristics and GEQ that can be used for designing DEGs and measuring game experience for children age 7-9 years in particular.

Evaluation of UAV Photogrammetric Accuracy for Mapping of Open Dump Based on Variation of Image Overlaps

Abhisit Bhatsada — 2020-06-30

Urbanization in developing countries has led to an increase in both quantified amount of municipal solid waste (MSW) generation and final disposal. While many countries are utilizing open dumping to dispose MSW, such a practice can cause environmental, social, and economic problems. Accurate spatial data in the form of mapping is necessary for construction and proper management of a disposal site as well as for systematic operation, site maintenance, and monitoring of the site. Although unmanned aerial vehicle (UAV) has widely been used in many survey applications, UAV has not yet been applied to the work related to open dumpsite. The aim of this study was to evaluate the accuracy of open dump mapping with different image overlaps for setting basic and standard UAV flight information. Ground sampling distance values were set to 5 cm/pixel, while flight configurations were varied from 80% to 90% and 75% to 90% for frontal and side overlaps, respectively. Root mean square error (RMSE) was used to represent the accuracy of the measurement. Ten ground control points for geo-referencing and 26-28 check points for accuracy evaluation were utilized. The results were classified based on the accuracy class as per the American Society for Photogrammetry and Remote Sensing standard. The best results were obtained when using 80% frontal overlap and 75% side overlap; these values resulted in the lowest RMSE on both horizontal and vertical coordinations for open dump mapping.

Synthesis of Cerium Oxide by Colloidal Emulsion Aphrons (CEAs) Method for Biodiesel Production

Wasinee Amesuwan — 2020-06-30

This study investigated the use of barium hydroxide doped ceria (Ba(OH)2–CeO₂) as solid based catalyst for the transesterification of palm oil with methanol to produce biodiesel. Cerium oxide was prepared by colloidal emulsion aphrons (CEAs), a type of dispersion method, which was then followed by calcination. The catalyst was evaluated for its activity in terms of the content of fatty acid methyl ester (%FAME). Moreover, the dependence of the %FAME on the reaction parameters, which included the amount of catalyst and reaction time, was studied. Physicochemical characteristics of the catalyst, as revealed by X-ray diffraction, Brunauer-Emmett-Teller analysis, scanning electron microscopy and differential thermal analysis/thermogravimetry, were also examined. The maximum methyl ester content was noted to be 94.65%. The optimal reaction condition for the transesterification was the use of 30:1 molar ratio of methanol to oil, with an addition of 8 wt.% Ba(OH)₂-CeO₂ catalyst and reaction time of 4 h.

Controlled Low-Strength Material (CLSM) from Industrial Waste Product of Kaolin

Aroondet Boonsung — 2020-06-30

This research was conducted to study the strength properties of controlled low-strength material, with aggregate replaced by the industrial waste kaolin (IWK) at 1%, 3%, 5%, 7%, 9% and 11% of fly ash (FA); ordinary portland cement (OPC) was used as the binder. The strength properties were evaluated via the unconfined compression test at curing ages of 3, 7, 14, 28 and 60 days. The amount of water used in the mixture was selected by considering the results of the flow test and slump test to obtain the desired consistencies. The results showed that liquid condition of the controlled low-strength material from kaolin was affected by the amount of fly ash used. The use of fly ash with cement helped reduce the water requirement by 8% when compared with the use of only cement as the binder. The more fly ash added, the more water could be reduced. This is because the fly ash particle shape was spherical. As a result, when the water was added to the mixture, the surface was coated with such particles; fly ash then became a lubricant. An increase in the binder (increasing OPC: FA) in the range of 1% to 11% did not affect the amount of water required to cause collapse at a certain value. The use of fly ash in the ordinary cement at every volume resulted in the time reduction of the slump value. In addition, the results of the unconfined compression test showed that fracture of the samples that contained more cement, even at a shorter curing time, exhibited stress hardening behaviour. On the other hand, if the sample contained less cement, even at a longer curing time, it would show the stress softening behaviour. The controlled low-strength material from industrial waste of kaolin mixed with cement and fly ash could develop adequate strength to meet the demand of work based on the requirements of the ACI 229R (ACI, 1999) standard.

A Mixed-Integer Linear Programming Model for Vegetables Harvest Planning: A Case Study of a Small Farmer

Panuchit Saisema — 2020-06-30

Harvest planning of various vegetables in response to consumer demand is a complex decision making process that may cause difficulties to farmers. This is due to the fact that several factors are related to vegetable plantations such as the growing period, starting and ending times for harvesting as well as harvested volume. A farmer usually plans the vegetable harvesting with his own experience without using any tool for effective planning, resulting in turn in the losses of sales opportunity. To alleviate such a problem, mixed-Integer linear programming (MILP) model has been developed to use as a decision supporting tool for harvest planning and to minimize the total cost. The results showed that the total cost from using the MILP model had reduced by 43.43% compared with that incurred by farmer’s own operations.

Postbuckling Behavior of Variable-Arc-Length Elastica Linked with Elastic-Plastic Rotational Spring Joint within the Span-Length of the Elastica

Nattaphat Chantarakunmanee — 2020-06-30

This paper reports the investigation on postbuckling behavior of a variable-arc-length elastica connected with a rotational spring joint where three types of the spring joint (i.e., linear elastic, bilinear elastic, and elastic-plastic) were considered. One end of the elastica was attached on the hinged joint while the remote end was placed on the horizontal slider support. The rotational spring joint was located at a given distance apart from the hinged joint. Compression force was exerted at the horizontal slider support to push the arc-length into the system; the postbuckling behavior was then observed. A set of governing differential equations were obtained from the equilibrium equations, moment-curvature relation and geometric relations. Since this problem is a two-point boundary value problem, the shooting method was employed in this study. Numerical integration (i.e., Runge-Kutta method) was performed so that the boundary conditions were satisfied. It was found that the elastica became unstable after buckling and, after yielding of the spring joint, the compression might drop suddenly, depending on the ratio of the stiffness, r = ₂ / ₁. The elastica could turn into stable equilibrium for an interval of total arc-length. Moreover, reverse rotation of the spring joint could occur, representing another interesting aspect of the problem.

UV Protection and Antibacterial Properties of Cotton Fabrics Dyed

Mahamasuhaimi Masae — 2020-06-30

The objective of this study was to develop the cotton fabric dyeing process using Monascus spp. A mordant, i.e., aluminum potassium sulphate, was used to dye fabric via the use of the meta-mordanting procedures. The color fastness to washing, water, perspiration and light of the dyed samples was determined according to the AATCC test methods. The UV-protection properties of the dyed fabrics were investigated via transmittance measurement using the calculated ultraviolet protection factor. Chemical functional groups of the dyes were characterized via Fourier-transform infrared spectroscopy. Antibacterial activity of the dyed fabrics was confirmed by exposing the samples to Staphylococcus aureus and Escherichia coli. The results showed that the fabrics dyed with Monascus spp. and mordanted with alum to pH 7 reduced the number of viable organisms by 69% and 97%, respectively, within 2 hours. Cotton fabrics dyed with Monascus spp. exhibited a shade of brown, while those mordanted with alum exhibited a red brown color shade. Color fastness to washing, perspiration, water and light was noted to be at fair to good level. The UV protection characteristics of the dyed samples were excellent. Monascus spp. contains citrinin, which exhibits antibacterial properties. Monascus spp. dye therefore has a potential to serve as a functional dye and be a part of the cotton dyeing natural colourant system.

Binderless Solid Fuel Pellets from by–product of Sugar Industry

Narathorn Mahantadsanapong — 2020-06-30

This research studied the compression of filter cake, which is a by-product from the sugar industry, into pellet form of solid fuel. The effects of compression pressure, pellet diameter as well as temperature and time of torrefaction were investigated. The results showed that solid fuel in the pellet form had higher heating value than the original form. The minimum pressure for forming pellets with the diameter and height of 1 cm was 30 bar, whereas the pellets with a larger diameter (1.5 cm) with the same height needed a higher pressure (40 bar). At the same pellet diameter, increasing the compression pressure resulted in the solid fuel pellets with higher heating value, pellet density, moisture and ash contents. Torrefaction at 250 and 300 °C for 0.5–2 h yielded the samples with higher heating values (21,689–22,642 kJ/kg) when compared with the values belonging to the original sample (13,954 kJ/kg). On the contrary, density of the pellets decreased from 0.72 g/cm³ to 0.48–0.89 g/cm³. Increased torrefaction temperature and time increased the heating value but decreased the pellet density.