Mindanao Journal of Science and Technology

Evaluation of Cassava Peeling Machine using Dimensional Analysis Technique

Adekola Adegoke — 2023-12-22

Cassava processing for various products requires an efficient peeling process. However, peeling – the first step in its processing – has been considered laborious and time-consuming; hence, the need for full mechanization. Several mechanical peeling approaches have been exploited by researchers toward achieving ideal peeling. In this study, an innovative abrasive cassava peeling machine, combining chemical and mechanical peeling methods, was used for the experiment using TMS 30572 and TME 419 cassava cultivars. The physical and technological characteristics of the motion of the roots within the peeling compartment were subjected to analysis. Model equations based on dimensional analysis were adopted to predict the functionalities between cassava and the peeler variables. The following cassava roots properties were established: distal diameter (TME 419: 15.20-26.50 mm; TME 30572: 10.20-35.10 mm), peel thickness (TME 419: 1.60-4 mm; TME 30572: 1.80-4 mm) and moisture content (TME 419: 59.20-61.18%; TME 30572: 58.40-60.40%). The machine’s peeling efficiency (μ), mechanical damage (λ), peel retention (P) and throughput capacity (η) were 62.02-86.45%, 1.26-2.90%, 8.26-11.63%, 900-1,210.5 kg/h, respectively, for both cultivars. A linear relationship was found between the machine speed, velocity of conveyance and peeling time. The study revealed that the machine resulted in the careful removal of the cassava peels achieving good peeling efficiency at a speed of 1,600 rpm < Nt < 2,600 rpm depending on the variety. It is recommended for peeling operations in cassava processing factories.

Dolomitic Limestone Powder: Cement Substitute in the Production of Structural Concrete Paving Blocks

Israel A. Baguhin — 2023-12-22

Manufacturers are replacing or combining cement with mineral additives such as slags, natural pozzolans, sand, diatomaceous earth and limestone to reduce carbon dioxide emissions and energy usage. Due to its high magnesium content, dolomitic limestone has long been utilized in concrete production to reduce costs and environmental risks associated with making cement. This study aimed to produce a reliable and appropriate concrete mixture for concrete paving blocks using dolomitic limestone powder that passed the no. 24 sieve as cement replacement at replacement levels of 0 (control mix), 8, 12, 16, 20, 24, 28 and 32%, satisfying the minimum compressive strength requirement for structural concrete of 20.7 MPa (3,000 psi). The ASTM E877-13 was used to sample the dolomitic limestone, and the 1:1.5:3 concrete class combination was utilized to proportion the quantities of cement, sand and aggregates (3/8”). After 28 days, the specimens were cured and the compressive strength, through the varying water-cement ratios in the concrete mixture, was determined. Results showed that dolomitic limestone powder can substitute cement by 16% by weight, using a concrete mix of 523-g cement, 936-g sand, 1,868-g gravel, 100-g dolomitic limestone powder, and 166-g water with a water-cement ratio of 0.318, exceeding the minimum necessary compressive strength of concrete of 20.7 MPa by 24.9% or 5.16 MPa. Therefore, it is advised to utilize this proven concrete mixture as a basis for a potential business venture in the production of concrete paving blocks for structural concrete applications such as walkways, sidewalks, parking lots and commercial areas, as well as in places where loads are very high, like airports, courtyards, docks and freight yards.

Soil Physicochemical Characteristics and Spore Density of Indigenous Arbuscular Mycorrhizal Fungi (AMF) in Different Vegetation Patches of a Marginal Upland in Central Philippines

Dernie T. Olguera — 2023-12-22

To show the importance of plant-microbe association in stressed tropical landscapes, the study evaluated the physicochemical characteristics and indigenous arbuscular mycorrhizal fungi (AMF) spore density in selected vegetation patches of marginal upland soils in Central Philippines. Five quadrats were used in the study, namely Andropogon aciculatus (control plot), Imperata cylindrica, Chromolaena odorata, Melastoma malabathricum and mixed vegetation patch. Results showed that soils in the studied vegetation patches had different physicochemical characteristics and AMF spore density. Although all patches had clay soil texture and comparable water-holding capacity, mixed vegetation patch had moderate compaction (1.33 g cm^-3) and higher porosity (50.31%) compared with the other patches, which had extreme compaction (1.37-1.65 g cm^-3) and lower porosity (37.74-48.76%). In terms of chemical properties, soils in different patches had moderate (5.69) to strongly acidic pH (5.13), moderate organic matter (2.69-2.91%) levels, low P (2.67-3.94 ppm) content and above critical K levels (0.2-1.2 cmol+ kg^-1). Results also revealed that C. odorata patch had the highest spore density count (11.33 spores 100 g^-1), followed by mixed vegetation (9 spores 100 g^-1), M. malabathricum (8.33 spores 100 g^-1), and A. aciculatus patch having the lowest spore density count (4 spores 100 g^-1). The significant spore density variability was attributed to the differences in soil’s physicochemical characteristics among the different vegetation patches and AMF host specificity. Spores detection, therefore, indicated AMF presence and helped the adaptation mechanism of the natural vegetation in this degraded upland.

J48-Based Decision Tree Algorithm in Detecting Kolb’s Learning Style Preferences of Information Technology Students

Las Johansen B. Caluza — 2023-12-22

Teacher education institutions developed interventions to augment both the Teacher’s teaching and the Learner’s learning process. Previous studies focused on detecting learning styles in e-learning using learning management systems and adaptive learning in the online learning process, specifically using the Felder-Silverman learning style model. On the contrary, this study aimed to develop a decision tree-based model to detect the Learner’s learning style inspired by Kolb’s learning style in a face-to-face learning environment. Knowledge discovery in databases through data mining was utilized using the J48 algorithm to develop a decision tree-based model. This study was participated by 408 out of 462 information technology students in a state university in the Philippines. The study’s result was able to develop four J48-based decision trees with conditional rule models for activist, reflector, theorist and pragmatist learners. The evaluation of the decision tree models using confusion matrix and receiver operating curve showed a very high accuracy detection of every learning style (weighted average of 88-96%). This result recommends applying this in an actual system or computer application for easy and fast learning style detection based on the characteristics of the learners.

Day-Ahead Electricity Load Forecasting with Multivariate Time Series

Lorenz Jan C. Crujido — 2023-12-22

The importance of day-ahead load forecasting cannot be overstated. Electricity load forecasting is highly important because it allows electric distribution utilities to increase their transmission efficiency and their revenues, increase the reliability of power supply, and correct decisions for future developments. In this paper, day-ahead load forecasting was studied using multivariate time series analysis. Traditional forecasting method such as seasonal autoregressive integrated moving average (SARIMA) was used. Machine learning algorithms such as Feed Forward Neural Network (FFNN) and Long Short Term Memory (LSTM) were also utilized to determine their applicability to short-term load forecasting. For SARIMA, only historical hourly load was needed while FFNN and LSTM required the addition of temperature data, hour of the day and day of the week, special events and previous hour load. In the prediction, FFNN and LSTM performed better with mean absolute percentage error (MAPE) of 1.80 and 1.75%, respectively, compared with SARIMA with a MAPE of 4.48%. The study demonstrated that machine learning like FFNN and LSTM outperformed the traditional SARIMA models, highlighting their effectiveness in applications such as short-term load forecasting in time series prediction.

Design, Development and Testing of Microcontroller Systems Simulator using PIC Microcontroller

Romel B. Cristobal — 2023-12-22

The inadequacy or absence of training equipment negatively impacts student performance, achievement and employability. Attempting to address this problem, the study was conducted to design, develop, fabricate and test a microcontroller systems simulator (MSS). The MSS was composed of the mainboard and development board comprising the PIC microcontroller, microcontroller circuits and input and output devices. The MSS was designed using AutoCAD, schematic design and circuit simulation software, and printed circuit board auto-routing software. A computerized cutting machine, laser laminator and ink printer were also used in the fabrication of the MSS boards. Test results showed that 12 and 24 VDC voltage readings were normal, sensors were working with the indicated specifications, and the MSS could perform automatic switching simulations. It was concluded that the MSS can effectively demonstrate microcontroller experiments and switching applications and it conformed to the required voltage and current ratings, electronics and electrical safety standards. It was also found that it is technically feasible to develop a microcontroller simulator utilizing commercially and locally available materials and spare parts.

Antibacterial Effect of Basil (Ocimum basilicum) and Table Salt as Alternative Disinfectants against Staphylococcus aureus

Norielle Gearem G. Garcia — 2023-12-22

This study was undertaken to evaluate the potency of basil (Ocimum basilicum) extract and table salt as alternative disinfectants based on their effect in inhibiting bacterial proliferation. A sample of bacteria (Staphylococcus aureus) with an initial mean density of 1.35 x 10³ CFU/mL was used as the bacterial test culture. Treatments included basil extract (T1), table salt (T2), ethanol (T3, positive control) and distilled water (T4, negative control). The antibacterial effect of the treatments was evaluated in terms of the measurement of the zones of inhibition which was further validated by monitoring the mean recovery counts of bacteria post-application with the treatments given at different concentrations (100, 50, 25 and 10%). The results showed that the larger diameter of the zones of inhibition (with mean measurements that ranged from 17.65 to 20.98 mm) was related to the application of basil extract, table salt and ethanol applied at 100% concentration compared with the 50% (mean measurements ranged from 14.03 to 17.67 mm) underscoring the minimum inhibitory concentration of the candidate disinfectants at 50%. There was a comparable significant reduction of bacterial recovery counts associated with the application of basil extract and ethanol only at 3 h that were not sustained until 6 h. The results indicated that basil extract and table salt at the prescribed concentrations could be used and therefore recommended as disinfectants.

Physicochemical and Physiological Properties of Okra [Abelmoschus esculentus (L.) Moench] Fruits Coated with Polysaccharide-Based Edible Coatings

Leif Marvin R. Gonzales — 2023-12-22

Okra is highly perishable due to its high respiration rate and high-water content, thus reducing its marketability. Hence, this study was conducted to evaluate the effect of different polysaccharide-based edible coatings on the physicochemical and physiological properties of okra fruits. The experiment was laid out in a completely randomized design with nine treatments and three replications. Four edible coatings were assessed at two different concentrations. The treatments comprised T0: uncoated (control), T1: 1% sodium alginate (AL), T2: 2% sodium alginate, T3: 1% pectin, T4: 2% pectin, T5: 1% carboxymethyl cellulose, T6: 2% carboxymethyl cellulose, T7: 1% cornstarch and T8: 2% cornstarch. Okra fruits were stored in refrigerated conditions with the temperature ranging from 9 to 11 °C and relative humidity of 76 to 85%. Samples were collected on days 0, 3, 6, 9, 12 and 15 for analysis of weight loss, firmness, shriveling, pH, total soluble solids (TSS), titratable acidity (TA), vitamin C, respiration rate, ethylene production and microbial growth. The results indicated that the use of polysaccharide-based edible coatings significantly influenced moisture and dry matter content, weight loss, firmness, shriveling, pH, TSS, TA, vitamin C, respiration and microbial count of okra fruits. The various coatings, including alginate, pectin, carboxymethyl cellulose and cornstarch, significantly preserved the quality of okra compared with the control treatment. Among the four coatings used, 2% alginate (w/v) demonstrated the most effective preservation of the fruit quality of okra.

Characterization of Neglected and Underutilized Fruits in the Philippines

Pablito M. Magdalita — 2023-12-22

Twelve previously unreported fruit species native to the Philippines were examined for their unique characteristics. ‘Bayag-usa’ (Voacanga globosa) is a 60.8±3.7 g dark gray, reniform fruit. Red mangosteen (Garcinia hombroniana) is a bright red, globose fruit weighing 45.2±7.77 g, with 18±2 °Brix total soluble solids (TSS). The false mangosteen (Garcinia xanthochymus) is light yellow, heart-shaped and weighs 151±36.46 g, with TSS at 16±0.89 °Brix. Yellow mabolo (Diospyros blancoi) is canary yellow, depressed ovate, weighing 273.33±87.9 g, with edible portion (EP) of 78.44±1.2%. ‘Kolis’ (Memecylon ovatum) is round, dark purple, weighing 0.73±0.02 g, with TSS at 13±1.41 °Brix and an EP of 84.2±7.59%. Raspberry Bush (Randia formosa) is a 2.03±0.18 g yellow, tubular fruit. ‘Gabiroba’ (Compomanesia xantocarpa) is round, yellow, weighs 11.95±1.68 g, has 18±1.08 oBrix TSS, and is sub-acid with a Titratable Acidity (TA) of 0.13±0.75 meq/10 mL juice. ‘Tugos’ (Alpinia galanga) is globose, yellow-brownish and weighs 1.55±0.50 g. ‘Gapas-gapas’ (Citrus hystrix) is sour, weighing 66.18±2.89 g, with a TA of 1.06±0.23 meq/10 mL juice. ‘Bisbis’ (Citrus aurantifolia) is green, weighing 36.59±2.81 g, with a TA of 0.85±0.26 meq/10 mL juice. Additionally, ‘Kolisom’ (Citrus hystrix var. micrantha) is green, sour, weighing 65.78±2.7 g, with a TA of 1.59±0.84 meq/10 mL juice, and ‘Kolong-kolong’ (Citrus hystrix var. boholensis) is also green, weighing 64±1.7 g, with a TA of 1.1±0.7 meq/10 mL juice. The study also explored the pharmacological and ethnobotanical uses of these diverse species.

Genotypic Profiling of Virulence and Antibiotic Resistance Patterns of Staphylococci and Streptococci Isolates from Dairy Cattle with Clinical Mastitis Infection in Region IV-A, Philippines

Amily E. Ancuelo — 2023-12-22

Staphylococci and Streptococci spp. play a significant role as primary causal agents of bovine mastitis. Farmers commonly employ the use of antibiotics as a widespread strategy for the management of mastitis infections. However, the frequent use of antibiotics is directly correlated to the increase in antimicrobial-resistant (AMR) bacterial strains resulting in some challenges in managing subsequent infections. In this current study, the virulence and AMR profiles of previously isolated Staphylococci and Streptococci bacterial strains from dairy cattle with clinical mastitis were evaluated to provide an overview of their pathogenic and resistant genetic characteristics. The incidence of virulence genes among Staphylococci isolates revealed low detection rates, whereas 42.2% of the Streptococci isolates were found to express the surface-anchored rib gene. The laminin-binding lmb and toxin β-hemolysin cylE genes were also frequently detected among Streptococci isolates. These observations suggest a strong association between Streptococci spp. and severe infection among the tested animals. Meanwhile, 28% of Staphylococci and 12.2% of Streptococci were observed to be resistant to three or more drug classes, thus considered multidrug-resistant. The most frequently detected AMR genes among Staphylococci isolates were aphA-1 (33%), mecA (25%), and blaSPM-1 (21%). Meanwhile, among Streptococci isolates, tetB (35%), blaIMP (31%) and ermA/TR (31%) were most prevalent. Although the phenotypic resistance of some isolates was comparable with its associated genotypic resistance, some isolates did not exhibit a consistent phenotype-genotype AMR. Nevertheless, the presence of these virulence and AMR genes in mastitis-associated pathogens is still critical because these genes can migrate across microbial populations, thus posing a serious threat to animal and public health.