Includes bibliographical references.

Evaluation of Object-Based Classification Methods For Mapping Benthic Habitats Using Bathymetric LiDAR Derivatives -- Developing an Energy Audit for Baseline and Scenario Analysis of a University Library -- Proposed Localized Wind-Driven Rain Test Parameters for Building Envelopes in Metro Manila -- Towards A Green and Sustainable Electropolishing Technology: Feasibility Studies on the Application of Choline Chloride-based Solvents for Electropolishing Aluminum -- Pitting Corrosion of Steinmann Stainless Steel Pins in Simulated Body Fluid Using Cyclic Polarization Technique.

[Article Title: Evaluation of Object-Based Classification Methods For Mapping Benthic Habitats Using Bathymetric LiDAR Derivatives/Ayin Tamondong, Ivy Elaine Cadalzo, Mia Shaira Estabillo, Gay Amabelle Co. Charmaine Cruz and Ariel Blanco, p. 1-18]

Abstract: Benthic habitats are one of the most productive ecosystems in existence. Unfortunately, they are declining in coverage globally due to natural and anthropogenic factors. Mapping and monitoring the status of these coastal ecosystems is critical for their protection. One of the tools capable of mapping such habitats is LiDAR remote sensing. This research aims to evaluate different object-based classification methods for classifying benthic habitats in Manicani Island, Guiuan, Eastern Samar using LiDAR derivatives. The bathymetric LiDAR data used in this research was obtained using an Optech Aquarius ALTM sensor. Before classification, LiDAR derivatives such as digital surface model (DSM), depth, plan curvature, profile curvature, rugosity, slope, slope of slope, broad-scale and fine-scale Bathymetric Position Index (BPI), and fractal dimension were extracted from the raw data. Principal components analysis was applied to eliminate redundant information. To classify the benthic habitats, an object-based image analysis (OBIA) approach was performed using eCognition. Training and validation data sets utilized in classification and accuracy assessment were gathered in the field using a handheld GPS receiver and video tows geotagged using a dual-frequency GPS receiver. The overall accuracies achieved in mapping benthic habitat from LiDAR derivatives were as follows: Hierarchical – 77.4%, Nearest Neighbor – 88.3%, Feature Space Optimization (FSO) – 82.4%, and SEparability and Thresholds (SEaTH) – 81.9%.

https://www.journals.upd.edu.ph/index.php/pej/article/view/7394

[Article Title: Developing an Energy Audit for Baseline and Scenario Analysis of a University Library/ Maxine Chan, Francine Beatrix Caram, Mary Abigail Contreras, Claudine Anne San Miguel and Mili-Ann Tamayao, p. 19-38]

Abstract: In an academic university building, the library is one of the most used facilities as a place for studying and research. To further understand the energy use within the library, a baseline energy consumption profile was created by studying the different equipment in the facility as well as how often people would use them through an energy audit. Lighting and temperature of the area were also measured and compared to current standards for workplace productivity (200-500 lux and 22.5-25.5 °C). Given baseline estimates, recommendations were formulated to optimize electricity consumption within the library while reducing corresponding CO2 emissions and power costs. Recommendations are expected to result in a significant decrease in total monthly energy consumption of the university library, amounting to Php 54,507/month electricity cost savings and 2.59 ktCO2 in monthly CO2 emissions reduction.

https://www.journals.upd.edu.ph/index.php/pej/article/view/7395

[Article Title: Proposed Localized Wind-Driven Rain Test Parameters for Building Envelopes in Metro Manila/ Homer Sadie and Nathaniel Diola, p. 39-54]

Abstract: Rainwater intrusions in building envelopes have been recognized as the primary source of material deterioration inside buildings. These occurrences are partially attributed to wind-driven rain (WDR) scenarios. Local testing procedures and parameters to assess systems of building envelopes against WDR and its contributing leakage have not yet been established. After adapting international methodologies, a set of testing parameters are calculated. Parameters are pairings of spray rates and static pressures associated with return period for Metro Manila. The flow rates range from 5.89-16.05 L/min m2, while the static pressure pairings range from 90 to 481 Pa for considered return periods of 2, 5, 10, 20 and 30 years. These calculated values are generally higher than the endorsed minimum from several ASTM standards and comparable to other testing parameters used in other countries. Therefore, the usage of preset WDR test parameters from the ASTM standards, might not reflect the expected climate event specific for Metro Manila.

https://www.journals.upd.edu.ph/index.php/pej/article/view/7396

[Article Title: Towards A Green and Sustainable Electropolishing Technology: Feasibility Studies on the Application of Choline Chloride-based Solvents for Electropolishing Aluminum/ Eden May Dela Peña, Miguel Paolo de Boda and Farley Sean Napiri, p. 55-72]

Abstract: In this study, electropolishing of aluminum was performed using ethaline, an ionic liquid mixture of choline chloride and ethylene glycol, as polishing electrolyte. Polishing was conducted using a two-electrode system at electrode potentials of 4.5 V and 6.0 V. Electropolishing removed pre-treatment artefacts such as scratches and yielded a smooth aluminum surface. Surface analysis revealed the presence of nodular or hemispherical features in the electropolished metal. Surface roughness measurements indicate optimum electropolishing time of 25 minutes and 15 minutes at potentials of 4.3 V and 6.0 V, respectively. Ethaline is a promising ionic liquid electrolyte for electropolishing aluminum.

https://www.journals.upd.edu.ph/index.php/pej/article/view/7397

[Article Title: Pitting Corrosion of Steinmann Stainless Steel Pins in Simulated Body Fluid Using Cyclic Polarization Technique/ Stephanie Santos and Manolo Mena, p. 73-86]

Abstract: Locally available Steinmann stainless steel pins were subjected to cyclic voltammetry in Kokubo simulated body fluid after immersion in SBF from 0 to 7 days. Results showed that the pins were susceptible to pitting corrosion from Day 0, with the degree of pitting increasing with the length of immersion. This may be due to the degradation of the initial passivation on the steel by SBF solution. SEM EDX analysis showed the presence of chloride precipitates in the pitting area. Chloride is known to induce autocatalytic corrosion of stainless steels. Optical Emission Spectroscopic analysis of the samples showed that one sample is SS304 and the other two were SS316L. The SS304 pins showed a higher tendency towards pitting corrosion when compared with the SS316L pins.

https://www.journals.upd.edu.ph/index.php/pej/article/view/7398