University of Mindanao
  • Davao, Philippines
Recent publications
Viewpoints on different assessment systems used in many educational bureaucracies are diverse and continually evolving. Schools are tasked with translating those reforms’ philosophies and principles into school-based assessment practices. However, it is unclear from research evidence what approach and factors best support the implementation of assessment reforms. To guide school leaders to design and implement school-based assessment reforms, there is a need to develop coherent knowledge of how school-based assessment reforms are implemented. We reviewed the literature on school-based assessment reforms using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. From a synthesis of the 28 articles included, we reported what approaches are used to implement assessment reforms and what factors influenced their implementation. Furthermore, we have proposed a framework that defines the political, cultural, structural, chronological, paradigmatic, and technological perspectives that need careful attention when implementing assessment reforms in schools.
Safety-critical situations inevitably require human intervention, thereby, exposing personnel to formidable risks. This encompasses various domains, such as bomb disposal, emergency response, and hazardous material handling, all underlining the paramount importance of personnel safety. This research is dedicated to the development of a wireless robotic hand that replicates predefined gestures, facilitated by image processing algorithms. The hand gesture classifier attains an accuracy rate of 94.67% in identifying and distinguishing gestures. The implementation of hand gesture robotic hand emulators in safety-critical scenarios emerges as a pivotal strategy to potentially replace human participation. This substitution substantially mitigates risks for personnel. Moreover, it stands to enhance safety standards by virtue of its automated and controlled operation, thus minimizing the vulnerability associated with manual intervention. Fundamentally, this study acts as empirical validation of the substantial transformative capabilities inherent in robotics. This has the potential to completely reshape how dangerous tasks are handled in various industries which has a direct impact on keeping people safe and protecting valuable lives. Even though this research investigates a constrained selection of hand gestures and operates within a time limit for emulation, it establishes the fundamental basis for future progress in human-robot interaction and the realm of gesture recognition.
Cellulosic fibers are one of the trend studies being conducted from the recent research due to their cost-effectiveness and abundance as biomass waste products from different plantations. The study aims to fabricate a dew extractor machine and analyze and characterize fibers based on their physical, mechanical, and chemical properties. The machine achieved the required torque, which is 370.645 N.m, and a speed of 28.82 rpm for the initial process for the sources of fiber by using a chain drive. Among the three fibers, the banana shows greater tensile strength with 221.225 MPa-418.59 7MPa for untreated and 191.376 MPa-715.428 MPa for treated. Napier has the smallest value of tensile strength with 77.944 MPa-146.731 MPa for untreated and 76.048 MPa-287.689 MPa for treated. The chemical properties of the fibers were analyzed using Fourier Transform Infrared Spectroscopy shows all three fibers have a similar single-, triple-and double-bond, namely a secondary aliphatic alcohol, alkene, and a non-conjugated alkene functional group. It can be concluded that treated fibers can withstand more stress, stretch even more, and therefore are more elastic than untreated fibers.
Every year, the Philippines experiences hot and rainy weather. For those who choose to remain at home, summer feels like torture. So, Filipinos have no choice but to turn on their air-conditioning system, which can cause their electricity bill to skyrocket. Corn husk fibers, being a waste product, have great potential to be applied in home textiles, home furnishing, carpet, rugs, and packaging of food grains and crops. The researchers thought of making thermal insulation ceiling panels made of corn husk fibers. The study yielded a result of 0.119 W/m.K for thermal conductivity using a calibrated hot box, below the 0.25 W/m.K maximum threshold for thermal conductivity value. Furthermore, its fire resistance characteristic made it less susceptible to small fire attacks. It was also found that the insulator has 2.19% and 8.42% water absorption values for short and long-term soaking, which is less than the 40% range value for water absorption. Hence, it can be said that it is an excellent thermal insulator.
Without a cure but preventable, Alkali-Silica Reaction (ASR), dubbed the “Concrete Cancer,” happens when alkali in cement bonds with silica in aggregates to form an expansive gel. This research aims to investigate expansion and influence mitigation of ASR in concrete by identifying potentially reactive aggregates causing its onset and using binary blended cement to slow down unwanted gel expansions through the mitigative ability found in its fly ash component. This research also observed variations in expansive behavior and the physical changes that arose after the experiments. Aggregate samples were collected from different quarries in Davao, Philippines, denoted as Deposit A, Deposit B, Deposit C, and Deposit D. These deposits were tested according to the ASTM C1260: Accelerated Mortar Bar Tests (AMBT) to identify a reactive group. Three aggregate groups, Deposit A, Deposit B, and Deposit C, were tagged as reactive due to exhibiting more than a 0.1% increase in lengths, indicating unideal expansion. Additional sets of AMBTs were done for the identified aggregates using blended cement as a binder to test the combinations' ability to minimize expansion. This resulted in an average expansion decrease per set of approximately 78%, 82%, and 85% for A, B, and C, respectively, further strengthening the reputation of fly ash as an effective mitigating SCM against ASR.
Scraps of Ethylene-Vinyl Acetate (EVA) foams from cutting out shoe soles are a waste produced by the footwear industry, and the recycling of these thermosetting materials is quite expensive and requires distinct procedures. Hence, an upcycling route to turn such waste into valuable material, such as utilizing it as a partial aggregate replacement in the production of concrete roof tile, was explored. This paper aims to investigate the effects of EVA on the bulk density, water absorption, thermal properties, water permeability, and transverse breaking strength of the concrete roof tile. The weight percentages of replaced natural aggregates in the concrete roof tile mixture are 5%, 7.5%, and 10%. The concrete roof tile with EVA aggregates demonstrated a lighter weight but higher water absorption. Also, its thermal conductivity presents promising results as it lessens the heat transfer compared to conventional concrete roof tiles. Moreover, the incorporation of EVA also positively affects the concrete roof tile's water permeability as it can hold the water longer than those without EVA. Finally, the transverse breaking strength of the concrete roof tiles with EVA contents resulted little or no difference compared to the conventional concrete roof tile.
The purpose of this study, titled The Prostitute in Margaret Atwood's The Handmaid's Tale and The Testaments, is to identify and analyze who among the characters in both novels possesses the characteristics of a Prostitute and Hetaeras, as classified by Simone de Beauvoir in her theory on the Other. The Prostitute, according to the concept, is the absolute Other, the object. However, she is also the exploiter. She is a prostitute for money and the men's recognition of her Otherness. According to the analysis, all of the Handmaids in the novels fit the classification, with their roles as two-legged wombs engaged in ceremonial monthly intercourse with high-ranking men. Moira, Paula, and Shunammite all exhibit characteristics of a prostitute, with Moira being the most obvious because she is a Jezebel, both a prisoner and a sex slave of Gilead's supposedly pure men and a prostitute for foreign tourists The study also looked at the significance and implications of the role of the prostitute in today's patriarchal society. The Prostitute's role teaches us that when male oppression occurs within societies, it is frequently justified by reference to culture, religion, politics, economy, and the established standards of social norms. Recognizing women as the subjects of their own lives and accepting women's rights as fundamental human rights necessitates reconsidering the institutions of family, religion, culture, tradition, and politics.
Wastewater is a by-product of industrial and commercial facilities. If not treated, it could cause environmental and health problems. The proposed IoT-Based Real-Time pH Monitoring of wastewater can regulate the disposed waste through web browsers. The device has undergone several trials with wastewater from the chemical laboratory at different pH levels. It gave the signal to the solenoid motor to position either close when the pH level is more significant than pH 7.5 and less than pH 6.5 or open when the pH level is pH 6.5 to pH 7.5. The output's accuracy was measured using buffer solutions at different temperatures. It showed that the value of the pH level varied in temperature with significantly small changes. The system monitoring in the web browser captured the data every minute and saved it in a database for data comparison purposes. The device conformed to the Department of Environmental Natural Resources - Environmental Management Bureau (DENR-EMB) in the Philippines' standard permissible pH level (pH 6.0 to pH 9.0). Using an Arduino NANO microcontroller that served as a central processing unit and a Node MCU to connect the system to the internet, the equivalent output of an industrial pH meter was obtained, allowing the user to monitor the system at any time using a web browser.
The Philippines is hit by different calamities and is considered one of the world's most disaster-prone countries, regularly ranking in the top three countries hit most by natural catastrophes. Foldable shelters provide private and secure living spaces for persons forced to leave or lose their usual housing due to a calamity. This study aimed to design a lightweight steel-framed temporary shelter that can withstand typhoon calamities and follows the design requirements mandated by the National Building Code and National Structural Code of the Philippines. The shelter's design concept emphasized its expandability, allowing it to accommodate one family of 4-5 persons. It also is designed to be deploy easily, safe, and efficient in post-disaster settings. The major factors considered when developing the shelter are the ease of assembly process, a compact and flexible structure, and adaptability to rapidly changing conditions. The structural analysis indicates that it can withstand a typhoon with an average wind speed of 220 kph but will fail in a super typhoon like Haiyan, with an average wind speed of 250 kph. Since this shelter is designed for temporary uses, the maximum wind capacity of 220 kph is acceptable and can be a reasonable basis for using these to replace other shelters.
Concrete is extremely vulnerable to crack formation. However, repair and monitoring can be labor-intensive and costly. The investigation focused on the augmentation of natural fiber-silica composite-containing concrete’s mechanical properties. Raw coconut husk fiber (CHF) was used to mix with sodium metasilicate, and the synthesized coir-silica composite (CSC) was mixed in a cementitious matrix to test its self-healing properties. The synthesized composite (CSC) has a sheet-like morphology, whereas the silica has a rough surface morphology based on the SEM-EDX micrographs. The presence of silica improved the thermal stability of the raw coconut husk fiber (CHF). Results demonstrated that both pristine condition and healed samples had enhanced mechanical properties with the addition of the CSC material. Hence, the produced composite embedded in concrete surpassed control specimens in terms of healing capability for compressive and tensile strengths after damage. Finally, a synthesis method was developed to prepare a coconut husk fiber-silica composite, demonstrating a viable upcycling route for coconut husks waste utilization.
Plastic is now regarded as the third most polluting waste source on a global scale, with its volume rising rapidly as the global population increases. Recycling plastics will help prevent serious environmental threats and add value to plastic waste by incorporating them into various applications, such as construction. Previous research primarily focuses on the investigation of replacing aggregates with plastic wastes in manufacturing concrete. There is a lack of study pertaining to the partial replacement of fine aggregates with plastic waste in producing PPB. In this study, PPB is produced by partially replacing fine aggregates with HDPE and PP plastic wastes. Results show that the 15% HDPE and 15% PP plastic waste replacement of fine aggregates exhibited maximum compressive strength at 11.1 MPa and 9.9 MPa, respectively. The maximum average density recorded was 2678.026 kg/m3, which shows a 23.95% increase compared to the reference block. Additionally, the replacement improved the infiltration rate of PPB, recording a maximum increase of 10% plastic waste replacement. The PPB with 15% HDPE replacement is identified as the optimum mixture and is best utilized in low-traffic areas.
Cardava banana pseudostem fibers (BPFs) are recently explored as a composite reinforcement. This is due to its improved thermal and mechanical stability effects for concrete applications. Silica, derived from sodium silicate and a modification additive, was explored as potential matrix in the self-healing applications. Herein, BPFs were prepared to produce BPF – silica composite (BPFSC) as concrete additive. The investigation focused on the interfacial adhesion of BPFs in the silica matrix to self-heal the concrete when subjected to cracks. The synthesized BPFSC has a sheet-like and a rough surface morphology based on the SEM micrographs. BPFs (100 mesh) were used to reinforce silica, and the synthesized composite (BPFSC) was mixed in a cementitious matrix (5% w/w) to test its potential self-healing properties. Results showed that the addition of the silica (SiO 2 ) improved the mechanical properties of concrete in both the pristine condition and healed samples. Notably, the BPFSC showed better mechanical performance than SiO 2 alone. This explained the good interfacial adhesion of BPF in the BPF – silica matrix. Hence, the prepared composite embedded in concrete showed significant healing potential concerning compressive and tensile strengths after damage, surpassing control specimens. Finally, a synthesis procedure was developed to prepare cardava banana pseudostem fiber – silica composite, showing a potential upcycling route of waste pseudostems for construction materials.
Natural fiber as a fiber reinforcement enhances the high-performance cement composites' strength, ductility, and durability requirements for a concrete application. This study aims to utilize an indigenous natural fiber-silica composite as an additive to cement. Pre-treated durian fibers extracted from durian rinds (100 mesh) were mixed with sodium metasilicate (Na 2 SiO 3 ), and the synthesized durian rind fiber-silica composite (DRFC) was utilized as a cement mass replacement (5% w/w) on concrete to test its effect to mechanical properties. SEM-EDX micrographs show that silica has a rough sheet-like morphology similar to DRFC. However, DRFC also contains a rough fibrous structure indicating the uniformly distributed durian rinds fiber (DRF) present in the composite matrix. Additionally, the presence of silica significantly improves the thermal stability of DRF. Results demonstrated that both concrete with DRF and DRFC additives have superior mechanical properties, surpassing the controlled specimens. Hence, the potential application of DRF to concrete demonstrates a viable upcycling route for durian rinds waste.
A species new to science, Cryptocoryne esquerionii Naive & Wongso from the island of Mindanao is herein described and illustrated. It differs significantly from all other Cryptocoryne species by its yellow, colliculate spathe with a long acuminate apex. A detailed description, colour plates, phenology, geographical distribution information and a provisional conservation status are provided. The discovery of this new endemic species further highlights the importance of the citizen science in exploring and conserving the Philippine biodiversity.
Pedestrian accidents are inevitable despite the inclusion of pedestrian lanes. Vehicle users tend to neglect pedestrian lanes unless law enforcers are watching. On the other hand, pedestrian users also have lapses in the use of the lanes. This innovative study aims to secure the people and vehicles who are crossing the road. With image processing, a new pedestrian lane system can distinguish pedestrians and cars as inputs for the system to work. The algorithm of the system could process the matching scenarios provided in the fuzzy logic decision table. A prototype design of the project was fabricated along with traffic lights and cameras. The accuracy of the whole system yielded a result of 96.67% for the entire system, with 30 samples covering six scenarios simulated randomly.
The model of optimal design of solar assisted cabinet dryer was formulated for green banana. The simulation model is composed of three systems: one for the water collector, one for the air collector and other for the drying cabinet. Economic and manufacturability factors were considered in the optimal design. A solar cabinet banana dryer utilizing a thermosyphon solar water heater as the main source of heat and a solar air heater as auxiliary source was tested with green Cavendish variety of banana as the drying specimen. From period April to June the experiment was conducted in the rooftop to ensure good solar irradiance. It was found out the solar water collector can generate a maximum water temperature of 60 °C and a drying chamber temperature of 50 °C during noon and at clear sky condition. Also the air heater generates about 40 °C. The temperature profile of the drying chamber resembles a sine curve. The temperature profile was lower than that of the mathematical model. These were contributed from the construction of the solar heater but overall performance.
Wind energy is a promising source of renewable energy. However, integrating energy harvester in an urban landscape poses a significant challenge. This study developed a wind turbine, a bio-inspired savonius that will blend with the environment. Savonius wind turbine is a vertical-axis wind turbine type used to convert wind force into torque on a rotating shaft. Using SolidWorks flow simulation, the different configuration was considered such as twist angle and guide vanes. Simulation shows a promising potential of this turbine. A scaled prototype was made and tested. Results showed that a 135° angle of twist with guide vanes is ideal and has the highest torque during its running condition in theoretical data. When it is made into a prototype, its actual torque proves to be lower than its theoretical torque. The actual data presents a promising power efficiency of 32.45%, higher than the usual average range for savonious wind turbines.
A low-cost mixed-mode natural convection dryer was designed to dry coconut kernels. The dryer was made of low-cost materials readily available in local areas. The dryer consists of two major parts, the heat collector and the chamber. The study aim to compare the performance of solar dryer with sun drying. The experiment was conducted in the open field at the University of Mindanao, Davao City, Davao del Sur, Philippines. Coconut cups were placed in the drying chamber and dried until the ideal moisture content is achieved. The temperature, and moisture content were observed during the experiment, as well as the weight of coconut. The drying chamber has a maximum temperature of 78.4 °C and a minimum temperature of 64.6 °C under a clear sky sunny weather. The dryer has reduced the initial moisture content of 54.86 to 6.82% in 21 h of drying.
Geological isolation with limited gene flow can shape phenotypic diversification among different populations or species. From Luzon northward to Taiwan lies a series of isolated volcanic islands (the Taiwan–Luzon volcanic belt) where three Pachyrhynchus species [P. sarcitis (Behrens, 1887), P. nobilis (Heller, 1912) and P. semperi (Heller, 1912)] (Coleoptera: Curculionidae: Entiminae: Pachyrhynchini) are sympatrically distributed. With intraspecific color variation across different islands, these three weevil species provide a unique opportunity to study genetic divergence associated with geographic isolation and/or phenotypic differences. In this study, genome-wide single nucleotide polymorphism (SNP) data derived from ddRAD-seq was used to reconstruct the speciation history and to delimit species within each of the three species. Our results indicate all three species have ancient diversification histories in southern islands of the Taiwan–Luzon volcanic belt instead of more recent diversification histories in northern islands. Ancestral effective population size estimations also support a scenario of a series of founder colonization events from southern to northern islands in the volcanic belt. Most island populations are monophyletic, and early-divergent populations with deep genetic structures are supported statistically as distinct species. However, color variations could occur between populations with very recent diversification, indicating a fast-evolving rate in the change of coloration, possibly due to müllerian mimicry or founder effects across this region.
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Adrian Mernilo Tamayo
  • Research and Publication Center
John Vianne Bauya Murcia
  • Research and Publications Center
Amelie L. Chico
  • College of Business Administration
Jefford Torres
  • Department of Electrical Engineering
Genesis Genelza
  • College of Teacher Education
Davao, Philippines