GABRIEL HOH TECK LING | Universiti Teknologi Malaysia - UTM (original) (raw)

Papers by GABRIEL HOH TECK LING

Sustainability, Mar 15, 2023

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Chemical engineering transactions, Feb 1, 2021

Majority of residents in many urban and suburban areas, especially in Southeast Asia, have seen a... more Majority of residents in many urban and suburban areas, especially in Southeast Asia, have seen a significant increase in time spent indoors over the past decade. It is not unusual for residents in these areas spending 70-90 % of their lives indoor either in home or office, and often in poorly ventilated rooms. These rooms are usually outfitted with ductless air conditioning (also known as room air conditioner) with no supply of fresh air for ventilation. The build-up of indoor air pollutants such as CO2, pathogens, and various volatile organic compounds in poorly ventilated room have been shown to be detrimental to both health and well-being its human occupants. This work aims to study the effect of introducing fresh air via a supply vent on the airflow within the room, while keeping track of the corresponding increase of energy consumption in the form of cooling capacity caused by ventilating warm fresh air into the room. To carry out this study, an air change per hour (ACH) of 10 supplied through different vent heights are simulated using a validated computational fluid dynamics model to investigate the behaviour of temperature, airflow, and energy consumption for five different vent-position cases. The simulation simulated case suggests that up to 27.7 % of a 1.0 horsepower (2.67 kW) air conditioner's cooling capacity may be required to maintain the room at 22 °C with noticeable difference in airflow pattern within the room depending on the vent position. These findings will serve as a guideline for practical applications in designing ventilation systems in a small-to-medium enclosed space.

Big data and cognitive computing, Mar 28, 2023

Journal of Urban Management, May 1, 2023

Research Square (Research Square), Aug 9, 2021

Hydrogen is a potential energy carrier for renewables that has a clean emission during the point ... more Hydrogen is a potential energy carrier for renewables that has a clean emission during the point of use. To implement hydrogen energy system in large-scale, a comprehensive hydrogen supply network should be built to supply the hydrogen with optimal infrastructure arrangement. Although the optimization of hydrogen supply chain has been extensively studied, the investigation of an integrated hydrogen-electricity supply chain is still lacking. Considering the interconvertibility of hydrogen and electricity, this study presents a spatial optimization framework that integrates geographical information system with mathematical modelling for the design and optimization of a photovoltaic-based hydrogen-electricity supply chain. The proposed framework allows the concurrent targeting of vehicle fuel and electricity demands as well as the identification of suitable locations for supply chain infrastructures. Case study results showed that the minimum cost of hydrogen-electricity supply chain is about 14.9 billion USD/y assuming two days of autonomy, and the cost of battery constitutes 43% of the total supply chain cost. When the days of autonomy is 8 and above, electricity storage in the form of hydrogen and reconversion through fuel cell is preferred.

Housing Theory and Society, Nov 30, 2022

Clean Technologies and Environmental Policy, 2022

Hydrogen is a potential energy carrier for renewable energy as it has a clean emission when consu... more Hydrogen is a potential energy carrier for renewable energy as it has a clean emission when consumed. To implement hydrogen energy system in large-scale, a comprehensive hydrogen supply network should be built to supply the required hydrogen with optimal infrastructure arrangement. Although the optimization of hydrogen gas supply chain has been extensively studied, the investigation into an integrated hydrogen-electricity supply chain is still lacking. Considering the interconvertibility of hydrogen and electricity, this study presents a spatial optimization framework that integrates geographical information with mathematical modeling for the design and optimization of a photovoltaic-based hydrogen-electricity supply chain. The proposed framework allows the concurrent targeting of vehicle fuel and electricity demands as well as the identification of suitable locations for supply chain infrastructures. The case study results show that the minimum cost of hydrogen-electricity supply chain is about 14.9 billion USD/y assuming two days of autonomy, and the cost of battery constitutes 43% of the total supply chain cost. When the days of autonomy is 8 and above, hydrogen storage is preferred and electricity is regenerated from hydrogen using fuel cell. Graphical abstract

PLANNING MALAYSIA JOURNAL, Dec 10, 2022

This paper attempts to examine the factors affecting the COVID-19 pandemic situation in Malaysia.... more This paper attempts to examine the factors affecting the COVID-19 pandemic situation in Malaysia. It investigates three major factors (social, economy and environment). Thirteen States and two Federal Territories of Malaysia were considered; and the data for the attributes of each major factor are derived from the official reports from the Department of Statistics Malaysia. Meanwhile, the infection rate and mortality rate of COVID-19 cases were obtained from the Ministry of Health, Malaysia. Using non-parametric statistical approach, the several interesting results are identified. Firstly, for the social factor, we found that the percentage of non-citizens has a positive relationship with both COVID-19 infection rate and mortality rate. Further, the number of students per teacher have a positive relationship with COVID-19 infection rate. Second, in terms of the economy factor, primary industry has a negative relationship with COVID-19 infection rate. Third, in the matter of social factor, it is found that population density and percentage of high-rise residential unit are positively related with COVID-19 infection rate. The result from this study can provides an insight for policymakers to understand factors contribute on the spread and severity of COVID-19 to informing better mitigation policy and control measures.

Interest in Indigenous Knowledge (IK) system has been particularly highlighted in flood disasters... more Interest in Indigenous Knowledge (IK) system has been particularly highlighted in flood disasters, due to the likely increase of flood events resulting from anthropogenic climate change through heavy precipitation, increased catchment wetness, and sea level rise. Therefore, bringing IK of flood risk reduction into focus and context to deepen the understanding of how people manage their own changing circumstances can bring more pertinent information about flood risk reduction. This paper reviews the significance of IK in flood risk reduction. Specifically, the paper discusses IK flood forecasting, early warning signs, adaptation and coping strategies in flood risk reduction around the world. The Methodological approach employed for this paper is the review of existing literature on IK in flood Disaster Risk Reduction (DRR), and then a summary of the outcomes of the studies reviewed was discussed. However, it was deduced from the review undertaken, the need for an intensive empirical study to be conducted to explore how efficient these strategies or techniques are, in relation to flood risk reduction, which this paper strongly recommends for further investigation. Additionally, the paper concludes by emphasizing that although the IK of flood risk reduction is embedded in varied regions around the globe, still there is a need for further study to be carried out in order to unveil why the similarities and variations in flood risk reduction practices/strategies between regions.

Open House International, Jun 29, 2022

PurposeWithin a gated community, management of common property presents great challenges. Therefo... more PurposeWithin a gated community, management of common property presents great challenges. Therefore, the diagnostic social ecological system (SES) framework proposed by Elinor Ostrom providing a holistic understanding of complex collective action problems in terms of management of commons is used to investigate key institutional-social-ecological factors influencing collective action in the context of gated communities.Design/methodology/approachIn this paper, Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) was used to systematically screen and review the relevant literature from 2000 to 2022, where 28 papers were selected for further analysis.FindingsThe study systematically identifies and categorises a series of variables related to self-organizing management in the gated community, and consequently a SES-based gated community management framework is developed. Based on the conceptual framework, the paper discusses logical interrelationships of institutional-social-ecological factors and their impacts on collective action performance of gated communities.Research limitations/implicationsApart from requiring empirical validation, the conceptual SES-based gated community management framework is certainly subject to continuous improvement in terms of refinement and addition of other potential determinants of gated community collective action.Originality/valueNot only the review paper provides updates on the latest gated-community collective action research, it also contributes theoretically by conceptualizing the SES framework and its institutional–social–ecological design principles in gated community management. Studying these factors should also be of practical significance because the findings ultimately offer policy insights and management strategies that help policy-makers, property developers and local communities to govern such neighbourhood common resources efficiently and sustainably.

Chemical engineering transactions, May 1, 2018

The production of palm oil will continue to rise with increasing demand of fats and oils. The inc... more The production of palm oil will continue to rise with increasing demand of fats and oils. The increase of palm oil production will result in high production of palm oil mill effluent (POME). POME is polluting due to its high chemical oxygen demand (COD) and biological oxygen demand (BOD). High COD and BOD of POME has the advantage to produce large amount of biogas through anaerobic digestion (AD). As upgraded biogas has equal composition to natural gas, it can be potentially used as compressed natural gas (CNG) or also known as bio-CNG. Bio-CNG at its current state is too expensive for implementation where subsidies are required to enable the technology, especially for countries where energy price is low such as in Malaysia. This paper studies on the economic potential of the bio-processing technology which consists of an anaerobic digester, purification unit, and compression up to 20 MPa as the biogas will be utilised as CNG. The parameter that is considered in the economic analysis includes the cost of the AD, purification unit, compression of biogas (based on the outlet pressure of the purification unit up to 20 MPa), transportation cost of bio-CNG, and lastly the profit obtained from the sales of bio-CNG. It is revealed that the system that utilises membrane separation technology has the lowest payback period and hence is most economical.

Facilities

Purpose Under Malaysian Law, the maintenance and management of common property have traditionally... more Purpose Under Malaysian Law, the maintenance and management of common property have traditionally been viewed as insoluble challenges in the self-organisational efforts for high-rise low-cost housing developments. As the population increases, more shared resources become heavily exploited with few willing to contribute towards the sustainability of resources. Many researchers argued a better way would be to convert these shared resources into a private or state-managed entity. Hence, with that assumption, this paper aims to examine how better physical characteristics can result in greater collective action. Design/methodology/approach This research paper adopted a quantitative method approach to determine how the standard of physical characteristics influenced the quality of collective action in high-rise low-cost housing. The method included a questionnaire survey of 519 parcel holders chosen via stratified purposeful random sampling from four high-rise low-cost housing areas. Find...

Sustainability Management Strategies and Impact in Developing Countries

DOAJ (DOAJ: Directory of Open Access Journals), Dec 1, 2021

IOP Conference Series: Earth and Environmental Science

Rapid urbanization is leading to sprawling development around the world today, which is becoming ... more Rapid urbanization is leading to sprawling development around the world today, which is becoming a concerning issue for researchers and planners. Urban sprawl depends on the dynamics of land use, mainly on the built-up growth in this area. The study aims to apply and test the applicability of the CA-Markov model in the land use/land cover change prediction for urban sprawling in Batticaloa Municipal Council, Sri Lanka. The secondary data were used, which are Landsat images for years 1990, 2000, 2010, and 2020. The Supervised Maximum Likelihood classification, the Markovian transition estimate, and the CA-Markov chain analysis were employed with ArcGIS 10.6.1, IDRISI 17.0, and MS-Excel 2013. The result revealed that the existing and simulated maps for the years 2000, 2010, and 2020 showed an almost equal probability of changes. The simulation for 2030 is credible for the future prediction, which showed that a significant estimate occurs. Therefore, the CA-Markov model is appropriate for land use/land cover predictions.

International Journal of Academic Research in Business and Social Sciences

Food waste like other forms of solid waste, imposes economic, social and environmental impact on ... more Food waste like other forms of solid waste, imposes economic, social and environmental impact on nations. This study assessed the quantity of food waste generated in Universiti Teknologi MARA, Perak Branch, Seri Iskandar Campus, Perak, Malaysia. This topic is one of important issue of food waste has recently received much attention and has been given high visibility. The impacts of food waste include greenhouse gases (GHG) emissions and climate change, ecological affects, sanitation issues, water footprint and nutrient loss. The study adopted a four-stage methodological approach: Site selection, quantitative analysis, online survey and synthesis of results. Food waste generated across the three selected canteens for four weeks was measured directly. In addition, 225 copies of questionnaire were administered to students online and was analysed with SPSS by descriptive statistical analysis to determine mean, standard deviation, frequency and percentage. Findings from the study revealed that the mean quantity of food waste generated at the sampled canteens, ranged between 24.89Kg ±3.904 and 62.840 Kg ± 4.091, while per capita food waste ranged between 20g to 70g per person/day. About 40% of respondents sampled in the study stated that they waste sauces and spread served them during meals, while 19.5% waste vegetables, 14.2% rice and 12.9% chicken or fish. The study identified limited lunch time, food taste, too much oil and large quantity of food served as some of the reasons for food waste. Thus, the major findings in this study identified the following as ways of reducing food waste in the dining halls: better estimation of portion size of meal on both students and stallholders since the dining halls operate on one-plate self-served buffet and staff service in some instances. The study recommends improvement in communication between local university students to know the type of meals the latter would want canteen operators to prepare. The future research should examine more public universities in the country. This capable to understand

Property Management, 2021

PurposeTo date, low-cost housing held under the common-property regime is faced with various coll... more PurposeTo date, low-cost housing held under the common-property regime is faced with various collective action or management issues in relation to common facilities. Understanding and unpacking key collective action components in a multi-dimensional and systematic fashion that help explain the status quo of the complex low-cost housing management is crucial, particularly in identifying potential factors contributing to the suboptimal self-governing outcome. Therefore, the purpose of this paper is to investigate the collective action of low-cost housing in Malaysia using Ostrom's institutional analysis development and social-ecological system framework (IAD-SES framework) as a theoretical framework.Design/methodology/approachFirst, a mixed-method research design was adopted where issues relating to the management of common properties of low-cost housing were identified in the Malaysian context. Second, the components of Ostrom's IAD framework relevant to collective action wer...