Pipe sizing of district cooling distribution network using implicit Colebrook-White equation

An implicit solution of Colebrook-White equation was used in calculating the friction factor for commercial steel pipes using Newton-Raphson method with Reynolds number ranging from 4.0×103 to 1.3×107. Initial value for iterative friction factor estimation was based on expanded form of Colebrook-White equation for larger values of Reynolds number with tolerance value of 1.0×10-8. Numerical results were compared with known explicit solutions and iterative procedure proposed by Lester in which, their mean difference, root-mean square deviation, mean relative error and correlation coefficient were evaluated. Correlation coefficients equal to unity and overall mean relative error of 4.821×10-8 were achieved for all fifteen (15) pipe cases with nominal diameters ranging from 100mmto 1,500mmwhen compared with iterative solution suggested by Lester. Student\u27s t-test for paired data was also used which yielded a calculated t-value of -5.406×10-4. Combining the piping network design criteria with the logical structure of friction factor calculation determines the pipe size of distribution network and defines the boundaries of chilled-water velocities at different pressure drop limits as a function of commercial steel pipe diameter according to ANSI B36.1

Optimal Restoration Strategy Of A Water Pipeline Network In Surigao City, Philippines

Quick recovery of water services immediately after an earthquake is critical. This is to minimize hazards to environmental sanitation and consequent health problems caused by the lack of potable water supply. It is necessary therefore that water lifeline operators establish restoration strategies to deal with damage scenarios in their respective concession areas specifically during extreme seismic events. The recent 6.7 magnitude earthquake in Surigao City due to the movement of the Philippine Fault Zone: Surigao segment underscored this need. However due to the complexity of the network a systematic restoration sequence that minimizes restoration time and maximizes delivery of water service should be employed. In this research, the authors employed Horn’s algorithm to determine the optimal restoration strategy of a pipeline network in Surigao City, Philippines. The repair sequence starts with the determination of a minimal spanning tree of the given pipeline network. The water source is designated as the root of this tree while the nodes represent the water demand at specific areas. The edges of the tree structure representing the pipelines connect the nodes. The assigned numeric value or weight of an edge (link) denotes the time to repair that specific pipeline. This value is a function of the length of the pipeline. The results show that an optimal job sequence may be carried out by considering maximal ratios of expanding family trees within the network. A least penalty function is a consequence of the optimal repair job sequence

Risk Analysis of Power Supply in San Juan, Surigao City, Philippines Due to Extreme Floods

The power supply system and its network components, like any other lifeline, are at risk due to extreme floods. Although various adaptive measures by the power producer can reduce this risk, the infrastructure (demand side) connected to the substation are still at risk to extreme inundation primarily because of its elevation, thus rendering the adaptation measures inadequate. In this paper, the authors use geographic information technology to quantify the risk of power loss to the consumers and the ensuing economic loss to the power producer considering various extreme inundation events. These extreme flood events were based on hypothetical rainfall with return periods of 2, 5, 10, 25 and 50 years. Specifically, the authors developed a risk curve for the power supply system in barangay San Juan, Surigao City, Surigao Del Norte, Philippines. The study shows that the percentage of households vulnerable to extreme floods for each return period are 22, 91, 93, 94 and 96. This power outage translates to a potential money loss range from US 1800 to US 36,000 for the power provider. To reduce the risk the following adaptation measures can be adopted by the local government (a) improve the drainage system, (b) rehabilitate Surigao River and consider buffer zone / overflow structures, (c) proper zoning and relocation of flood residents to elevated areas and (d) install new transformers to isolate households that are frequently flooded so power outage is reduced during extreme events. © 2014 American Society of Civil Engineers

The state of health in flood-prone areas in the Philippines: The case on the cities of Iligan and Cagayan de Oro

The Philippines suffers frequent typhoons every year hence the country is susceptible to experience disastrous flooding. This extreme event causes various effects in the community specifically infrastructural and social system damages. Flooding also causes numerous health effects that deteriorate the wellbeing of the affected population. Iligan City is known to be an area prone to flooding in the Philippines. This paper examines the state of health of communities affected by flooding occurrences through knowledge and preparedness, health impacts, and emergency response of various state actors during and after flooding incidents. Data were collected through an analysis of different documents, key informant interviews, and focus groups in the cities of Iligan and Cagayan de Oro. Results show data from various sources and narratives regarding the degree of preparedness before the flood among community members. During the flooding occurrence, different community damages were mentioned. Due to the destructive nature of floods, community members also stated different health impacts whether immediate, short term, or long term. After the flood, different emergency response and relief were provided. However, citizens and community also cited difficulties about the provision of relief and health care. This study can be used for initiatives in reducing risks and vulnerability in floods. © 2020 Taylor & Francis Group, LLC

A Perception Study of an Integrated Water System Project in a Water Scarce Community in the Philippines

The Integrated Water System (IWS) offers alternative water and sanitation services that can potentially benefit rural communities experiencing water scarcity. The IWS described in this study comprises three systems: The Rainwater Harvesting System (RWHS), Water Treatment System (WTS), and Eco-Toilet System (ETS). RWHS and WTS make use of rainwater, which can be utilized for several domestic uses, especially during wet season. ETS has several benefits to users including promotion of environmental and public health, as well as food security. Despite the potential benefits of the IWS components, the perceived acceptance of its users threatens the success of its implementation. This study focuses on determining the significant factors that can influence the social acceptance of IWS in the Municipality of Mulanay, Quezon Province, Philippines. This study considers behavioral intention as an indicator of social acceptance of the IWS components. The framework of this study is based on the combined technology acceptance model and theory of planned behavior (C-TAM-TPB) concept. C-TAM-TPB was analyzed using Partial Least Square–Structural Equation Modeling (PLS–SEM). The result of the C-TAM-TPB evaluation reveals that the user’s attitude towards use (ATU), including its significant predictors, can promote behavioral intention towards use of the IWS components. This study can further improve the development of IWS projects

A perception study of an integrated water system project in a water scarce community in the Philippines

© 2019 by the authors. The Integrated Water System (IWS) offers alternative water and sanitation services that can potentially benefit rural communities experiencing water scarcity. The IWS described in this study comprises three systems: The Rainwater Harvesting System (RWHS), Water Treatment System (WTS), and Eco-Toilet System (ETS). RWHS and WTS make use of rainwater, which can be utilized for several domestic uses, especially during wet season. ETS has several benefits to users including promotion of environmental and public health, as well as food security. Despite the potential benefits of the IWS components, the perceived acceptance of its users threatens the success of its implementation. This study focuses on determining the significant factors that can influence the social acceptance of IWS in the Municipality of Mulanay, Quezon Province, Philippines. This study considers behavioral intention as an indicator of social acceptance of the IWS components. The framework of this study is based on the combined technology acceptance model and theory of planned behavior (C-TAM-TPB) concept. C-TAM-TPB was analyzed using Partial Least Square-Structural Equation Modeling (PLS-SEM). The result of the C-TAM-TPB evaluation reveals that the user\u27s attitude towards use (ATU), including its significant predictors, can promote behavioral intention towards use of the IWS components. This study can further improve the development of IWS projects

Perceptions and attitudes toward eco-toilet systems in rural areas: A case study in the Philippines

© 2018 by the authors. Death due to diseases from poor sanitation is a serious global issue and it has become one of the priorities of the United Nations\u27 Sustainable Development Goals (i.e., SDG6). This SDG6 aims to provide adequate improved sanitation facilities to over 2.3 billion people around the world who have no or limited access to sanitation, wherein more than two-thirds of these un-served people live in rural areas. One of the strategies for addressing this global issue is through emerging sustainable sanitation technologies such as the Eco-Toilet System (ETS), which uses small amounts of water or is even waterless and recovers nutrients from human waste thereby promoting water-energy conservation, improved sanitation and supplement nutrients essential to plant growth. Social acceptance, however, remains a key barrier in deploying the ETS. A social perception study on the use of the ETS was conducted in a rural community in Mulanay, Philippines. The researchers analyzed the proposed combined technology acceptance model and theory of planned behavior (C-TAM-TPB) using multiple linear regression and the Mann-Whitney U-test to evaluate the perceptions and attitudes of a rural community towards the use of the ETS. The results showed that more than 50% of the respondents are aware of the nutrient value of human excreta and believe that it is usable as fertilizer; however, less than 25% prefer to utilize it for food production. Results also indicate that the behavior of the users is driven by their attitude (β = 0.420, p-value \u3c 0.010). Moreover, the Mann-Whitney U-test results revealed that people who are knowledgeable of the nutrient value of human excreta and are willing to collect them have more positive attitude towards the ETS