Volume 33 (03) August 2021

Hydrogenic effluent is the effluent from the bio-hydrogen production process via dark fermentation. It mainly consists of volatile fatty acids, residual sugars, and organic solid residues with a high carbon oxygen demand (COD), which prohibits direct discharge to the environment. Therefore, a post-process after dark fermentation to utilize the organic substances in the hydrogenic effluent is needed to complete the organic conversion and reduce the COD load. This review discussed the use of organic substances in the hydrogenic effluent to produce bioenergy, including bio-hydrogen, through photo fermentation and microbial electrolysis cells, and to produce methane by anaerobic digestion. Furthermore, the advantages and disadvantages of using hydrogenic effluent to generate bio-hydrogen and methane and the challenges and future perspectives on utilizing the hydrogenic effluent are discussed.

Keywords : Dark fermentation; Hydrogenic effluent; Photo fermentation; Microbial electrolysis cells; Two-stage anaerobic digestion

Crime rates are one of the biggest problems in today’s modern society, especially in urban cities. Various techniques on crime prediction and detection have been developed by previous researchers in reducing the crime rates that keep increasing throughout the year as well as to assist the government authorities in combating crimes. These include studies on forecasting crime activities based on both primary and secondary data that include numerical data, statistics, video, and images related to various categories of crimes. Thus, in this study, a mini-review is conducted related to the database used as well as methods that have been developed by previous researches related to crime classification, crime analysis and forecasting of crime or crime prediction. Further, a new technique will be proposed in the detection of crime activities. The proposed technique involves evaluation and validation of several Deep Learning (DL) specifically the Convolutional Neural Network (CNN) along with the type of database to be used specifically for street crime detection that focuses on snatch theft.

Keywords: Crime Prediction; crime classification; snatch theft; street crime; deep learning

Sistem radar ekadenyut berfungsi untuk mengesan objek sasaran dengan menggunakan isyarat Jumlah dan Perbezaan daripada isyarat pantulan. Penggunaan antena jenis parabola dalam sistem radar konvensional mempunyai kelemahan dari segi ruang, jisim dan kos pembuatan. Oleh itu, antena jalur mikro telah dicadangkan kerana ia berprofil rata, ringan dan lebih murah untuk difabrikasi. Pelbagai peranti diguna untuk menghasilkan isyarat jumlah dan perbezaan yang penting seperti persimpangan hibrid, pengganding berarah, pembanding dan lain-lain kaedah berkaitan dikaji dalam kertas ini. Ini kerana setiap peranti mempunyai kelebihan dan kekangan tersendiri. Antena jalur mikro ekadenyut juga boleh direkabentuk pada lapisan tunggal dan berbilang. Struktur antena berlapisan tunggal bersaiz lebih kecil dan berkos rendah. Walaupun begitu, kekurangannya adalah ia mempunyai lebar jalur yang rendah. Sebaliknya, struktur berbilang lapisan pula mempunyai lebar jalur yang tinggi berbanding lapisan tunggal. Namun, pada masa yang sama ia bersaiz lebih tebal, sukar untuk diintegrasi serta memerlukan kos pembuatan yang lebih mahal. Didapati gabungan antara rekabentuk antena berstruktur berlapisan tunggal dengan pengganding hibrid berpotensi memberi kelebihan dari segi keringkasan, ruang dan kos.

Katakunci: Antena ekadenyut; jalur mikro; isyarat jumlah; rangkaian pembanding

A monopulse radar system functions to detect targeted objects by using Sum and Difference signals from the reflected signals. The use of parabolic type antennas in conventional radar systems has disadvantages in terms of space, mass, and manufacturing costs. Therefore, microstrip antennas have been proposed because they are flat, lightweight, and cheaper to fabricate. Multiple devices used to produce the important sum and difference signals i.e., hybrid junctions, directional coupler, comparator, and other related methods are studied in this paper. This is due to each of them has their own advantages and limitations. Monopulse microstrip antenna also can be designed in single and multiple layers. Single layer antenna structure is smaller in size and low cost. However, the downside of this structure is having low bandwidth. On the other hand, the multi-layer structure has a higher bandwidth compared to single layer. Nevertheless, at the same time it is thicker in size, difficult to integrate as well as requires more expensive manufacturing costs. It is found that the combination of a single layered antenna structure design and hybrid coupler has the potential to provide better advantages in terms of simplicity, space and cost.

Keywords: Monopulse antenna; microstrip; sum signal; comparator network

The main objective of this study is to investigate the physical, chemical and biological effects of compost made from food waste and unshredded dry leaves and to evaluate the performance of food waste compost on the growth of dwarf crape jasmine (dwarf Tabernaemontana divaricate). Food waste and dry leaves with a ratio of 3:1 have been added to the passive aeration-static bioreactor. The composting was carried out for 40 days. The physical, chemical, biological and morphological changes that occurred during the composting process were identified and evaluated. The plants were grown in media containing nine different proportions of compost and the plant growth was measured after 150 days. The results show that a maximum composting temperature of 47.8 °C and a decrease in the moisture content were achieved. The pH value increased while the electrical conductivity decreased during the composting process. The TOC decreased from 56% to 42%. The nutrient value of the composts was all within the recommended range. Among the treatments, the 5%-20% compost mixture shows the greatest growth development. Results in this study indicate that food waste composting with high EC compost value can be used to promote dwarf crape jasmine growth, provided that the mixture contains low compost dosage.

Keywords: Composting; dry leaves; passive aeration; plant growth; campus sustainability

The application of the thermal alliesthesial concept through pre-cooling strategies in tropical buildings has attracted customers by purging surplus body heat, particularly at the entry point of their transitional space. However, there is little empirical evidence on the impact of thermal alliesthesia on the human subject’s perception of sensation and pleasantness. This study aims to investigate this relationship in the thermoneutral zone and various affective responses based on simulated transient thermal environments. Twenty nine healthy college-aged participants are recruited for a series of thermal alliesthesia climate chamber experiments. The predominant ET* setting refers to the participant’s preferred temperature, that is, 25.1 °C (±1.0). Three experiment stages with a total of nine hours, namely, Stage A (predominant ET*: 22 °C), Stage B (predominant ET*: 24 °C), and Stage C (predominant ET*: 26 °C) are devised to simulate the working commute of office workers in and out of an air-conditioning building during warm weather conditions. The results show that a high proportion of participants are indifferent up to 11 °C of down-step despite encountering corrective transitions within the thermoneutral zone. Pre-cooling strategies are not successful in eliciting thermal pleasure responses in any of the three stages. These findings suggest that a preconditioned indoor environment of 24 to 26 °C ET* is thermally sufficient when designing for transient thermal environments, thereby, eliminating the need for over-cooling.

Keywords: Thermal alliesthesia; thermal sensation vote; thermal shock; transient thermal environment; psychophysical measurement; climate chamber experiment

Increased volumes of solid waste generation continue unabated due mainly to rapid population increase, urban migration, economic enhancements, and modern lifestyles. Two significant factors contributing directly to the higher volumes of solid waste generation are population and gross domestic product (GDP). In Phase 1 of this study, a correlation analysis with a Pearson coefficient of more than 93% (r > 0.93) shows a strong positive linear relationship between the amount of solid waste generation and population and GDP. Phase 2 provides a multilinear regression analysis and the development of a regression model. They indicate that a 1-unit increment in the amount of solid waste generation is caused by 0.06 of the population and 0.119 of GDP while ßo remains constant at 124.449. Therefore, the multilinear regression model in this study can be applied by solid waste management authorities in Malaysia to accurately forecast future solid waste generation volumes. However, further investigation on other significance factors are suggested for future work in order to develop a holistic model for solid waste management in Malaysia.

Keywords: Solid waste generation; correlation analysis; multilinear regression model; population; gross domestic product

The Oil and Gas (O&G) industry is one of the riskiest, most dynamic and challenging industries and plays a vital role in every nation’s economy. Like any other major industry, O&G is exposed to a host of both predictable and unpredictable risks. Joint venture projects (JVP) are often regarded as a risky business as there is a high failure rate among them because of the complexities involved. This paper aims to identify the critical risk factors (CRFs) of JVPs for O&G between Malaysia and Thailand. Via systematic literature review (SLR) the risk factors for O&G and JVPs around the globe are identified and a set of questions relating to them were designed and used in a pilot study. A total of 15 respondents from different background experiences working in O&G JVPs were requested to answer the designed questionnaire during the pilot study. The questionnaire survey passed the required Cronbach Alpha value of 0.6 with a score of 0.98. The data collected involved 170 respondents currently working or have worked in O&G JVPs. The relative importance index (RII) for each risk factor’s (RF) value was quantified and the RFs ranked based on the value. A RII value exceeding 60% is considered to have agreement and of importance to the respondents. The RII value can be used as an indicator to rank the RFs from the most to the least critical. The CRF categories determined in this study are environmental, cultural and social, and organisation. Under environmental, the main CRFs are losses due to fluctuations in exchange rates/interest rates. For cultural and social, the main CRFs are problems associated with cultural differences and cooperation. Organisational issues related to organisational fit, incompetent project management team, difficulty in finding and keeping skilled workers, and low worker productivity. All the listed RFs underwent a comprehensive study on their impact and probability of occurrence to determine the best processes, methods, and tools for managing the risks. It is recommended that key players in the O&G industry consider all the RFs of JVPs during the risk management evaluation stage.

Keywords: Joint Venture Project (JVP), Malaysia, Oil and Gas (O&G), Thailand.Risk Management

Alternative energy sources have gained increasing attention due to the diminishing fossil fuel reserve. However, awareness of the importance and use of this alternative energy is still lacking in developing countries, especially in Malaysia. Alternative energy technology is also not widely known amongst students. Community awareness of the importance and usability of alternative energy to ensure the preservation of the earth and nature remains less due to the convenience of the community to existing power sources from fossil fuel. The dependence on fossil fuel has contributed to 40% of the carbon dioxide emission damaging the ecosystem and will undoubtedly have adverse effects in the future. Hence, replacing this energy source with alternative sources is necessary to preserve the environment. To increase public awareness regarding this issue, scholars should create an application that would be easily accessible to the society. This study aims to criticise public’s awareness and challenges faced in educating the community on alternative energy. Society awareness is important in maintaining and preserving the environment because alternative energy sources are eco-friendly and produce less carbon dioxide than existing energy resources. This article also examines the development of education modules for students especially in Malaysia. Additionally, a curriculum oriented in higher education is recommended to produce a generation that loves nature and explores the environment with the development of science and technology. Comparisons of education systems among developed countries are helpful in achieving this objective.

Keywords : Alternative energy; higher education; awareness; challenge; Malaysia

One of the main assembly processes in Body Shop produce BIW (Body in White). Automated framing system is used to assemble main sub assembly of body parts to become a BIW. Among the challenges using BIW framing are high investment, change of model or product life cycle and multiple or mixed model in a single line.This paper conducts a systematic review on BIW framing systems for automotive scope. Study and compare on the framing systems used have been carried out. Some examples of different BIW framing systems are shown. The current trend indicates that the framing systems changed from dedicated model to multiple models which seek flexibility approach to add in. Major or big automotive OEM’s have their own design of BIW framing system.

Keywords: Manufacturing; automotive; framing systems

The Covid-19 is a worldwide pandemic that has changed and disrupted the world economic perspective. The construction industry, which has already been a major growth engine for the economy, has also been totally shut down. The pandemic is having a wide-ranging effect on construction and infrastructure projects globally. All developments and projects have been put on hold until further notice. Indeed, the current pandemic is a significant cause of project delays in Malaysia that influenced in all industries. The evolution of the disease and its impact on the construction industry is extremely uncertain. As a result, it is wise to discuss the impact of Covid-19 on the construction industry at the beginning and end of the crisis in order to prepare for the potential risk and learn lessons for future planning. The aim of this research is to determine the impact of Covid-19 in civil engineering construction industry. In Malaysia, the entire construction and repair work progress that have been subjected to Movement Control Order (MCO) was suspended and thus causes project suspension, labor impact and work loss, time overrun, cost overrun, and financial consequences. In order to control the Covid-19 transmission, Malaysia implemented Standard Operating Procedures (SOP) during the restriction period of the Conditional Movement Control Order (CMCO). Besides, it is recommended to utilize the construction technologies in order to overcome the problem that occurred due to Covid-19. The usage of construction technologies could develop a sustainable country and those technologies can be beneficial in the post Covid-19 as a new norm in Malaysia.

Keywords: Covid-19; construction industry; MCO; CMCO; SOP; technologies; new norm

This paper aimed to review existing literature on student hostel building facilities and its room’s indoor environmental comfort condition in Malaysia’s public university. This study is structured by brief analysis on relevant studies located globally and subsequently, focusing more on studies located in Malaysia. An overview of the subject matter is presented to provide insight. These are supported by reviews of published papers from the last 15 years (2005-2020) in relevancy to the subject area which includes important sub-areas. The literature search was conducted via academic search engines such as Google Scholar, Taylor and Francis Online, ResearchGate, Emerald Insight, Academia, SpringerLink, and ScienceDirect. Terms relevant to the subject area such as “Student Hostel”, “Hostel”, “Hostel Facilities”, “Student Accommodation”, “University Accommodation” and “University Facilities” are used for the literature search using the academic search engine. In achieving a more accurate search specific to a University’s student accommodation (hostel building), a manual filtration was conducted to comb through the search results achieved from the academic search engines. The result of this literature review is a brief compilation of 18 global studies and focused on 29 studies in Malaysia, which are further classified/ grouped to form the structure of the paper. The review covers sub-areas such as building occupant’s indoor environment health-related issues, comfort, and satisfaction. This review is significant and necessary as its input function as a continuous monitoring study for this field, enriching the current body of knowledge and may be a point of reference for future studies.

Keywords: University; hostel; indoor environment; health; comfort

In 2016, almost 95% of the collected waste were taken to about 156 treatment disposal facilities that are distributed throughout Peninsular Malaysia, yet municipal solid waste (MSW) open dumping is common wherever land is available. Previous studies show that the land-use activities influenced the waste generation. The issue of non-compliance such as illegal change of land-use zoning and conflicts in development plans are among others that affect environmental sustainability. Hence, this paper focuses on how land-use planners include MSW management (MSWM) in their development planning. As a case study, the research considers 30 government town planners and 30 registered town planning consultants with the Malaysian Institute of Planners. A close-ended questionnaire method was adopted in this research. To design the questions, three aspects were considered: technical, management, and behaviour and the questions were structured based on literature review, books, and personal experience of the people involved. This research further identifies the issue concerning the reasons for the lack of involvement of land-use planners to include MSWM. Results show that land-use planners are aware of the regulations, national plans, and policies regarding MSWM in Malaysia but lack actions in their planning due to several reasons, such as inadequate expertise and insufficient funding. The findings in this research are expected to provide useful guidelines for policy makers.

Keywords: Land use; municipal solid waste management; behaviour; town planner

The purpose of this study is to review past works in water demands and sustainable water supply planning in Nigeria as reported by many researchers and to determine how to improve the water supply infrastructure sustainably. Nigeria is endowed with abundant surface water and ground water resources. The mean annual rainfall along the coast in the south east is 4 800 mm while it is less than 500 mm in the north east. These water sources are not tapped to the fullest and most of them are polluted and unsafe for use, resulting to scarcity of potable water in most communities. Water crisis is prevalent in most cities and this is further exacerbated by deteriorating infrastructure, political instability, and poorly regulated water laws. The result of the water crisis has led to detrimental consequences for its citizens as child mortality and water-borne disease-related deaths have grown exponentially. Unsuitability of water distribution facilities, quantity of water transported, too much walking distance, long lines at water points, poor maintenance and inadequate bulk water development brought about inefficiency of the facility. The water demand and supply in some countries in the world and many towns in Nigeria were reported. The method adopted in the study involved the use of journals, books and other related literature. The result showed that water supply systems in most places in the country are in poor state, unorganized and incomplete. All countries highlighted showed many problems at various degrees in provision of the facility. Attempt was made to fill some gaps in the literature. Public enlightenment, financing, monitoring, maintenance and juicy annual remuneration packages for best water users are recommended as powerful tools towards sustenance of the water supply infrastructure.

Keywords: Potable water; sustainability; public enlightenment; water pricing; remuneration packages

Roads play a significant part of economic development. Due to financial constraints, in many developing countries like Botswana, there are large networks of unpaved roads. The major detriment effect of unpaved or gravel roads is dust emissions. Dust affects the climate change which in turn increases the generation of dust. This has a huge impact on human health which has risen to great concern. The best solution to mitigate dust emission from gravel roads is to seal the gravel roads but this cannot be easily achieved due to financial constraints. Traditionally, road managers have controlled dust by applying calcium chloride or magnesium chloride to the road surface. However, these salts easily leach out of the soil during precipitation events and may not be an option in environmentally sensitive areas. Bio-enzymes have emerged as environmentally friendly soil stabilizers. They are cheap and can easily be available. In this review paper the use of bio-enzymes as stabilizers and a solution to reducing dust will be reviewed, health effects of dust in this exercise to try and see if they can mitigate dust on earth roads that have been constructed using material at site or calcrete. The findings could spread the awareness of effects of dust in Botswana so that the public and private sector can help in supplying the enzymes to reduce health issues affecting the society in Botswana. It will also help decision-makers to make a wise choice of which bio-enzyme to be used effectively.

Keywords: Unpaved roads; dust; bio-enzymes; health effects

This research presents the influence of mixing-water quality on the compressive strength properties of concrete using secondary and tertiary waste water treatment source, borehole and distilled water sources. Popular criteria for water quality assessment for concrete works involves the impression that once it is fit for consumption or drinking, it is therefore suitable for concrete works while other alternatives are suitability of the water used in terms of being clean and free from deleterious substances. However, these requirements may not provide a water suitability evaluation baseline for concrete works because some water quality which do not meet up with these requirements have been observed to produce satisfactory results in terms of strength and durability property performance of concrete. Statistical comparative-analysis techniques are required to evaluate the effects of water from control or referenced source of absolute quality with those of questionable quality so as to validate its usage for concrete works. The physiochemical characteristics of the water samples were ascertained before they were utilized for the concrete production and the setting time characteristics were derived, showing longer setting time results SWWT and TWWT due to high level of COD compared to DW and BW. The concrete samples produced were cured for varying hydration periods ranging from 7 – 28 days and their respective compressive strength values obtained in the laboratory. From the results, distilled water produced a maximum average compressive strength of 17.96 N/mm2 while secondary wastewater source produced the minimum results of 12.09 N/mm2. Statistical evaluation was carried out on the experimental data using ANOVA and Dunnet post-hoc test to validate the experimental findings and the details derived from the computations explains the importance of ascertaining the quality of water used for concrete production so as to achieve better overall concrete performance in terms of mechanical and durability properties.

Keywords: Concrete compressive strength; cement hydration; water quality; Dunnet test; concrete curing

Concrete is the most commonly used building material. Nowadays, the world has seen the construction of engineering applications that has become difficult and complicated. Therefore, it is important to have high strength and adequate workability. Besides that, the glass fibre is highly beneficial as a construction material for reinforced concrete as it can be identified as one of the numerous compelling topics related to its benefits. This study contributes to the specification and classification of glass fibre reinforced concrete (GFRC). However, ordinary concrete has limited ductility, slight resistance to cracking, and insufficient tensile strength. Internal micro-cracks in the concrete are visible, and the proliferation of such micro-cracks caused its weak tensile strength. When a certain percentage of fibre is added to the concrete, it improves the properties of the strain, namely, resistance to cracking, ductility, toughness, and flexure strength. The current paper outlines the experimental study conducted on the usage of glass fibre with structural concrete. The parameters were used in percentages, which varied from 0.5% to 2% by weight of cement in concrete, and the properties of the FRC (fibre reinforced concrete), such as ultrasonic pulse velocity test, flexure strength, and compressive strength were examined. However, it refers to an increase in deformation before failure of the structural concrete, reinforced with a high ratio of GFR. The results show good performance of concretes containing glass fibre and increasing glass fibre content, increasing the compressive strength.

Keywords: Glass fibre reinforced concrete; glass fibre; ultrasonic pulse velocity test; flexure strength; compressive strength

Private-Public Partnership (PPP) is an increasingly popular choice for policy-makers in implementing critical public projects. Through the examination of essential factors of success of PPP and establishes an empirical model of PPP in the construction project in Malaysia. The PPP implementation model was hypothesised to investigate the measurements and dimensions of technology, organisational and project characteristics as critical success factors of PPP implementation. A quantitative methodology was employed to validate the measurements, hypothesis testing, and validate a structural model of PPP implementation. A total of 238 respondents were involved in the survey of the hypothesised PPP model. SPSS version 22, as well as Analysis of Moment Variance (AMOS) software, was employed to analyse the data gathered. Path analysis and mediated regression analysis of the structural equation model succeeded in determining the mediating effect of stakeholder and procurement on the relationship among critical success factors and PPP implementation. The overall results show a significant positive interaction of organisational, technical, and project characteristics as essential factors of success on stakeholder and procurement as a mediator on the achievement of PPP implementation. This paper highlights not only the vital success factors for PPP but also offers a fundamental contribution model achieved through the empirical model of critical success factors and PPP implementation in the construction project in Malaysia. This study succeeds in establishing and validating a structural model of the PPP implementation model. The model contributes to the body of knowledge of PPP and benefits to practitioners as primary guidance on construction and business development.

Keywords: Public-private partnership, Construction industry, critical success factors, Measurements, Dimensions.

Bucket is key and primary component of heavy construction machinery such as excavators. It has to bear high impact loads during digging process, resulting in large stress and deformations. This research work has been focused on reducing stress and deformations produced in excavator bucket due to digging. For this purpose, different design patents of excavator buckets (including ornamental designs) were considered. Various models of excavator buckets were developed by varying geometrical parameters such as number of blade teeth/tips and bucket curvature. Finite element analysis of these models was carried out by using ANSYS in order to determine stress and strains. Maximum values of Von Mises stress, principal stress, factor of safety and total deformation were evaluated numerically for all three-dimensional geometric models. Excavator bucket with least values of stress and deformations, but largest factor of safety, was identified through numerical computations. Mechanical performance of ornamental buckets having quarter circular curvature with 6 blade teeth was observed to be better as compared to designs having single blade strip or 5 blade teeth. Mass reduction up to 2.5%, while the stress reduction and factor of safety enhancement up to 9.6% was achieved by incorporating 6 blade teeth in ornamental design of excavator bucket.

Keywords: Blade teeth; deformation; Excavator Bucket; Finite Element Analysis; Ornamental Design; stress

Penghasilan karbon teraktif daripada herba telah mendapat perhatian dan minat ramai penyelidik. Hal ini demikian kerana tumbuhan herba mempunyai prestasi yang baik dalam proses penyingkiran dan pemulihan logam berat. Tambahan pula, kosnya yang rendah dan ketersediaannya dengan kuantiti yang banyak menarik minat para penyelidik untuk menghasilkan karbon teraktif daripada herba. Herba adalah alternatif yang lebih murah, berkesan daripada karbon aktif komersial (AC) untuk penyingkiran logam berat dan pewarna tekstil berasaskan air. Terdapat pelbagai jenis tanaman herba yang digunakan dalam ujikaji ini. Antaranya termasuklah daum neem, daun kari, daun moringga dan daun tulasi. Selain itu, bahan penjerap lain yang juga boleh digunakan termasuk sekam padi; sekam kelapa; sisa kulit nangka dan sebagainya. Kaedah yang sering digunakan bagi menghasilkan karbon teraktif daripada herba ialah proses pengaktifan yang terdiri daripada pengaktifan fizikal dan kimia. Kaedah-kaedah ini boleh memberi kesan yang positif mahupun negatif terhadap ciri-ciri dan sifat kimia atau fizikal karbon teraktif yang diperbuat daripada herba. Dalam kajian ini, faktor-faktor yang mempengaruhi kapasiti penjerapan dan kecekapan penjerapan diperhatikan daripada kajian kepustaakaan dan dibandingkan dengan keputusan ujikaji. Selain itu, beberapa hasil dari kajian terkini berkenaan karbon teraktif yang disediakan dari pelbagai jenis herba dan kaedah pengaktifan yang berkaitan dengan karbon teraktif daripada herba turut dibincangkan. Evolusi penjerapan telah berubah dari pendekatan alternatif kepada teknik yang betul dan mempunyai banyak kelebihan. Prestasi penjerapan juga lebih memuaskan dari segi kapasiti penjerapan dan menyelesaikan masalah pencemaran air sisa dengan cara yang lebih menjimatkan. Justeru dapat mengatasi sebahagian daripada masalah sisa pepejal di seluruh dunia.

Kata kunci: Herba; karbon teraktif; logam berat; pengaktifan fizikal; pengaktifan kimia
Abstract English

The production of activated carbon from herbs has attracted the attention and interest of many researchers. This is because herbal plants have good performance in the process of removal and recovery of heavy metals. Furthermore, its low cost and availability in large quantities attracted researchers to produce activated carbon from herbs. Herbs are a cheaper, effective alternative to commercial activated carbon for the removal of heavy metals and water-based textile dyes. There are various types of herbal plants used in this experiment, which are neem, curry, moringa and tulasi leaves. Besides that, other adsorbents can also be used such as rice husk, coconut husk and jackfruit skin residue. Activation process consisting of physical and chemical activation is a common method used to produce activated carbon from herbs. These methods may affect both the chemical and physical of the activated carbon obtained from herbs. In this study, the factors influencing the adsorption capacity and adsorption efficiency were observed from the literature review and compare to the experimental results. Current study on activated carbon generated from various herbs and itsactivation methods from herbs are also discussed. The evolution of adsorption has changed from an alternative approach to a proper technique and has many advantages. The adsorption performance is also more satisfactory in terms of adsorption capacity and solves the problem of wastewater pollution in a more economical way. Thus, it is also able to overcome some of the problems of solid waste around the world.

Keywords: Herb; activated carbon; heavy metal; physical activation; chemical activation

Bus ridership is affected by the quality of the bus service. Level of Service (LOS) and bus headways are among the key factors for the quality of bus service. This study aims to measure the quality of bus service based on Level of Service (LOS), the reliability of bus headway and its relationship with the number of private vehicles in George Town CBD of Penang. Several bus route for Rapid Penang bus services (11, 101, 201, 301, CAT and CT7) were selected according to the maximum headway (30 minutes) that calculated using the Transit Capacity and Quality Service Manual (TCQSM). Bus arrival time was observed at the bus stops and the traffic count was conducted to obtain the volume of private vehicles during peak hours. Level of Service (LOS) was determined using TCQSM on-time performance calculations. This study found that bus route No 11, 101, 201 and 301 did not comply with the estimated headway schedule. These bus routes were classified as LOS D and LOS E, whereas bus route CAT showed reliable service with LOS A and LOS B. Interestingly, the findings also reported that the high number of private vehicles affecting only LOS and the reliability of certain bus routes were significant. It shows that there are other limiting factors that cause the bus services unreliable and thus increase the waiting time of passengers.

Keywords: Quality of bus service; Level of Service (LOS)bus; bus headway; bus reliability; bus delay

The goal of achieving concrete with adequate durability properties in terms of reduced susceptibility to alkali-silica and mechanical-strength behaviour has led to several high-performance materials development. While the use of Bambara nut shell ash in concrete is gaining acceptance in various applications, the mineralogical composition of such by-product materials cannot be easily controlled as a manufactured pozzolan. In this research work, the characterization and use of BNSA in concrete production was investigated. A mix proportion of 1:3:6 with water cement ratio of 0.55 were used. The percentage replacement of cement with BNSA from 0-40%. Concrete cubes of 150mm × 150mm × 150mm of OPC/BNSA were cast and cured at 3, 7, 28, 60 and 90 days respectively. At the end of each period of hydration, three replicate concrete samples for each period of hydration were crushed and their average comprehensive strength recorded. The result for the compressive strength test indicated rise in percentage difference as the BNSA replacement ratio increases from 5% to 40% with a value of 20.69% to 46.53% respectively. The concrete density response showed slight increment in percentage difference with a value of 0.85% to 3.47% for BNSA replacement ratio of 5% to 40% respectively. The Poisson ratio test results obtained indicates percentage difference increase as the BNSA ratio increases from 5% to 40% with a value of 5.17% to 11.14% respectively. Furthermore, the young’s modulus of elasticity results obtained showed percentage difference rise from 9.4% to 14.17% as BNSA ratio increases from 10.81% to 29.412% as BNSA replacement ratio increases from 5% to 40% respectively. The results indicate satisfactory performance at 5% replacement.

Keywords: Compressive strength; density; poisson ratio; Young’s modulus of Elasticity and Modulus of Rigidity; Bambara nut shell ash

The transverse rumble strip (TRS) is one of the methods used to improve the driver’s alertness to its driving and reduce their speed. However, the presence of a TRS causes unevenness on the road surface and may result in ground vibration when heavy vehicles passes it. This ground vibration may cause discomfort to the people living adjacent to the road. Therefore, there is a need to evaluate the level of ground vibration resulting from heavy vehicles passing over TRS especially on typical federal road in Malaysia which contains high percentage of fast-moving heavy vehicles. Ground vibration assessment study was conducted at federal road of Kluang-Batu Pahat Road (FT050) by using existing heavy vehicles in the traffic stream as study samples. ICP accelerometer and computer software Dewesoft7 have been used to measure and analyse the level of vibration generated. The results indicate heavy vehicles at a speed of 50 km/h, 33 km/h and 24km/h generate ground vibration level of 1.24 mm/s, 2.30 mm/s and 0.76 mm/s respectively. Other factors such as the weight of the heavy vehicles may involve in ground vibration generation mechanism as the results shown that there was no direct correlation between vehicle speed and level of ground vibration. All the generated ground vibration levels were found to be within the allowable limit set by Department of Environment Malaysia (DOE) standard guidelines.

Keywords: Ground vibration; transverse rumble strip; heavy vehicle; road safety

Atterberg limits are one of the fundamental geotechnical parameters used to assess the settlement and other volume change parameters of engineering soils containing clays. This paper describes index test results on expansive soil treated with rice husk ash (RHA) and 5%, 10%, and 15% quicklime activated rice husk ash (QARHA) obtained using laboratory testing procedure. The cost of conventional binders used in earthwork has necessitated the need to look for cheaper materials that serve the same purpose. Also, the extent of environmental poisoning due to the use of cement is worrisome and has motivated the use of alternative and green supplementary cements in soils stabilization. However, previous research works have dwelt on the use of ash derived from the combustion of solid waste materials like rice husk ash. But the present work has gone a step further to activate the properties of rice husk ash with three proportions of quicklime and this novel procedure has not been reported by any work in recent times. After preliminary tests, the test soil was classified as highly plastic soil. The soil was further subjected to treatment exercise at the rate of 0% (control), 2%, 4%, 6%, 8%, and 10% addition of RHA, 5%-QARHA, 10%-QARHA, and 15%-QARHA by weight of test soil. The RHA addition improved the index properties; liquid and plastic limits and plasticity index at varying rates. The rates of improvement show that the higher the rate of activation of rice husk ash with quicklime, the higher the pozzolanic performance, which tends to cement the soil particles together and improve the consistency through flocculation. Finally, rice husk ash and its composites achieved by quicklime activation process have shown to be alternative cementing construction materials for use as binders in the modification of expansive soils utilized as subgrade materials.

Keywords: Clayey soil; liquid limit; plastic limit; plasticity index; shrinkage; adsorbed moisture; black cotton soil; clay activity; clay content; construction materials.

Ineffective fire safety management is one of the severe issues in public buildings, especially in Nigeria. There has been a significant increase in fire disaster cases in Nigeria in the last 25 years, the incidence of fire disasters becomes the most significant and ultimate threat to building occupants, building and its contents, as well as the economic growth of the nation. Therefore, in order to ensure the safety of building occupants, building contents, the essential features depend on the fire safety protection system, which should be under the fire safety regulation requirements. Nonetheless, practical fire safety management could remedy the damages or rates of injury in fire events. This study presents the findings on the investigation of the effectiveness of fire safety management strategy in Nigeria public buildings. This study attempts to determine the factors affecting improper fire safety management and determine the level of effective implementation of fire safety management components. From the study, safety training and adequate fire safety compliance are the factors that affect improper fire safety management the most. The level of effective implementation of fire safety management strategy is low, which translated to inadequate fire safety management. The most effective approach identified to improve the fire safety management and achievement of fire safety objectives is through effective fire safety management strategy and improvement in fire safety training arrangement and absolute compliance with the fire safety regulations.

Keywords: Public buildings; fire safety management; fire safety; fire safety components

The safety of building occupants during fire emergencies depends mainly on the occupant’s behavior in the fire event. Therefore, this study investigates the behavior of high–rise building occupants in Nigeria when they hear the sound of fire alarm under fire drill. The study adopted a survey research design. The population for this study consists of 349 low and high-rise building occupants across six north-central state of Nigeria. A research question was used to direct the study. A structured questionnaire was used to collect data from the respondents which was duly validated by an expert in the field of fire safety. Cronbach Alpha reliability technique was used to determine the internal consistency of the questionnaire items at 0.90. Data collected were analysed through confirmatory factor analysis (CFA) using Statistical Package for Social Sciences (SPSS) and Analysis of Moment of Statistics (Amos). After a preliminary analysis (descriptive), data from respondents were found suitable for presence in confirmatory factor analysis (CFA), The CFA was performed, and results of the analysis support the one-factor model of occupants behavior in building when they hear the sound of the alarm during a building fire can enhance early evacuation and safety of lives and properties. The study found that occupants required nine actions to be taken when they hear the sound of fire alarm under investigation. However, the study recommended that fire training; total compliance with the relevant fire safety regulations, fire drill, fire communication, and effective fire safety management should be organized for the high or low-rise building occupants to enhance their knowledge of fire safety in a building.

Keywords: Behaviour; fire alarm; fire safety; high rise buildings; fire situation

Reusing waste plastic can significantly contribute to saving the environment from further pollution and the economy from extra expenses. Waste plastics have a vital role in the current asphalt applications. Trial sections of roads made with waste plastic modified asphalt during 2019 in Australia, highlighted the significant importance of laboratory assessments; however, they are yet to be conducted. This study investigates the impact of using local waste Polyethylene Terephthalate (PET) plastic in bitumen binder class C320, which is a common bitumen type used for local road surfacing in Australia. The evaluation of numerous contents of waste PET modified bitumen is carried out before and after ageing conditions. Dynamic Shear Rheometer (DSR), Rolling Thin Film Oven (RTFOT) and Pressure ageing Vessel (PAV) tests were utilised to examine the rutting, fatigue, and ageing of bitumen binder. The results displayed that the use of waste plastics results in enhanced rutting and ageing resistances. Based on DSR results, bitumen samples modified with waste PET display improved performance in terms of rising the complex shear modulus and reducing the bitumen’s susceptibility to deformation at high temperatures. Furthermore, 8% of waste PET increases the fatigue cracking resistance as it shows a low fatigue factor. Further rutting and fatigue tests on asphalt mixtures samples are recommended to better understand the mechanical properties of waste PET plastic on modified C320 asphalt mixtures.

Keywords: waste plastic; rheology; rutting; fatigue; modified bitumen; environmental impact.

The argument of ‘architecture is gesture’ suggests an episteme of artefact that celebrates the narration of human culture. This article explores the ‘gesture’ of mosque architecture. The exploration is conducted with particular reference to the ornamentation of minbar. In the context of Malay art, minbar is considered evidence of traditional ingenuity. The design of minbar reflects the beauty of intricate composition and the skillfulness of craftsmanship. Visits to old mosques as recommended by the Malacca Museums Corporation enable the researchers to select minbars with unique design and carvings. The ornamentation of minbars with reference to three selected old mosques in Melaka, namely, Masjid Peringgit, Masjid Kampung Hulu, and Masjid Kampung Keling are discussed. The discussion highlights the ornamentation of minbars as a response to the cultural convergence in Melaka. The article recommends the study of minbars to be concentrated more on its function as ‘signs’ instead of just a mere ‘aesthetic element’. In this respect, the study of minbars may enrich the holistic meaning of Islamic architecture. It can also be seen as a sign of a harmonious plural society in 18th century Melaka.

Keywords: Minbar; Ornamentation; Mosque architecture; Sign; Culture.

Industrial workers need a safe working environment to ensure their wellbeing is protected while performing tasks. Occupational noise is one of the most prevalent problems in industries due to nature of the industry. Therefore, this paper aimed to evaluate the occupational noise exposure in one of the plastic factories in Klang Valley, Malaysia. Noise measurement has been done in all production lines, crushing department, packaging department and officers’ area. The noise measurements were taken 1 to 3 metres from the source of noise at several points for each line and departments using sound level meter. Average noise level at all measurement location noted LAeq less than 80 dBA, except one point in line B and the crushing area. The packaging department recorded the lowest noise level, with LAeq 64.8 dBA and LAmax of 69.2 dBA. While, the crushing department is the noisiest area in the factory, with LAmax 105 dBA and LAeq 100.9 dBA. The average noise level at majority location in the factory is less than 80 dBA which means it is at a safe range. The workers do not need any personal hearing protection equipment during working, which was according to the Occupational Safety & Health (Noise Exposure) Regulations 2019 noise regulations in Malaysia, except the crushing area only. In conclusion, evaluation of noise exposure in each section can provide a good understanding of the occupational noise level experienced by different workers at different departments. It can help the management to strategize and plan the noise control approach, especially at the area that may have risk of hearing loss for their workers.

Keywords: Occupational noise; crushing task; plastic factory; sound level meter

End-of-life vehicles (ELV) policy implementation has long been a hotly debated issue in Malaysia. Vehicles that have become ELVs should be disposed of accordingly to prevent environmental pollution and also for the purpose of recycling useful materials, particularly metals. The automotive industry affects the earth environment through greenhouse gas emissions such as air-conditioning gas (CFC/HFC) which will increase global warming and uncontrolled use of raw materials. Even poorly managed ELV waste will cause gas emissions and toxic substances to be released to the environment. To reduce this problem, the implementation of an ELV policy should be seriously considered. In order to have a successful implementation of the ELV policy, support from the public is essential. Thus, this study aims to understand the ELV related laws and their implementation in the neighbouring countries and to ascertain public perception on ELV implementation in Malaysia. The study involves literature search on implemented ELV laws in the neighbouring countries and a survey involving 58 respondents. Results from the survey were analysed using SPSS. This paper presents and discusses the findings from the study. The study indicates that the level of public awareness and acceptance of ELV implementation are quite low. In general, it can be concluded that the implementation of ELV in Malaysia needs to be carefully studied before it is implemented in order to ensure acceptance from the public.

Keywords: End of life vehicle; ELV law; public acceptance

Malaysia terletak di kawasan garisan khatulistiwa yang mempunyai suhu yang seragam, kelembapan yang tinggi, dan curahan hujan yang banyak. Curahan hujan yang banyak ditentukan oleh corak tiupan angin monsun dan pengaruh sifat topografi tempatan. Malaysia dipengaruhi dua jenis tiupan angin monsun yang utama iaitu angin Monsun Barat Daya (MBD) yang bertiup pada bulan Mei hingga September manakala Monsun Timur Laut (MTL) bertiup pada bulan November hingga Mac setiap tahun. Malaysia juga merupakan sebuah negara yang dikelilingi laut menyebabkan kesan bayu laut dan bayu darat ke atas corak tiupan angin adalah tinggi. Curahan hujan yang banyak di Malaysia adalah bersesuaian dengan kajian yang dilaksanakan iaitu dengan menganalisa data hujan 3B42 dari satelit TRMM yang dikenali sebagai Analisa Kerpasan Satelit Majmuk, TRMM (‘TRMM Multi-Satellite Precipitation Analysis’, TMPA). Sebanyak 14 kawasan kajian terdiri dari lapan kawasan dari Semenanjung Malaysia (SM) dan enam kawasan dari Malaysia Timur (MT) untuk tempoh 11 tahun bermula tahun 2009 hingga 2019. Kajian ini mengkaji intensiti hujan diurnal dengan mengikut data hujan temporal dan spasial dengan menggunakan Model Segal pada sela masa 1-minit serta kesannya terhadap angin monsun di Malaysia. Model Segal merupakan model yang terbaik untuk penukaran data hujan bagi kawasan Malaysia dan data hujan ini juga boleh mengetahui kawasan yang sering dilanda hujan lebat dan sebaliknya. Penukaran data hujan pada sela masa 1-minit boleh menjamin kestabilan statistik taburan hujan di sesuatu kawasan kajian yang dipengaruhi oleh kepelbagaian bentuk muka bumi, pergerakan angin monsun, dan kedudukan garis lintang permukaan tersebut. Hasil dari kajian ini mendapati, kawasan kajian Kuching, Sarawak menerima kadar taburan hujan 1-minit iaitu 175.25mm/jam dengan purata hujan tahunan 4641.34mm yang paling tinggi bagi seluruh kawasan kajian di Malaysia. Kawasan kajian Cameron Highlands menerima kadar taburan hujan 1-minit yang paling rendah bagi SM iaitu 103.09mm/ jam manakala kadar taburan hujan 1-minit yang paling tinggi ialah kawasan kajian Kota Bahru, Kelantan iaitu 171.13mm/ jam, dan kawasan Kota Bahru juga menerima purata hujan tahunan yang paling tinggi di SM sebanyak 3013.33mm. Kawasan Cameron Highlands terletak di bahagian Banjaran Titiwangsa yang merupakan tulang belakang bagi kawasan SM dan ia dilindungi dengan tiupan angin MTL yang kuat. Hasil kajian ini mendapati, kawasan kajian Mersing, Johor menerima purata hujan harian, bulanan, dan tahunan yang paling rendah di dalam seluruh 14 kawasan kajian iaitu sebanyak 1992.98mm. Corak taburan hujan di kawasan pantai timur SM dan seluruh negeri Sarawak menerima hujan lebat yang dipengaruhi angin MTL dan mempunyai pola purata hujan diurnal yang sama iaitu mempunyai dua titik maksimum hujan dalam sehari. Hasil dari kajian ini juga mendapati jumlah taburan hujan di setiap kawasan adalah berbeza dari semasa ke semasa. Selain pengaruh angin monsun, fenomena El Nino dan La Nina yang dikenali sebagai El Nino Southern Oscillation (ENSO) juga mempengaruhi taburan hujan di sesuatu kawasan di mana fenomena itu berpunca daripada perubahan suhu permukaan air laut di bahagian khatulistiwa Lautan Pasifik. Data hujan pada tahun 2015 dan 2016 di dalam kajian ini mendapati kebanyakan kawasan kajian memberi kesan pengaruh fenomena El Nino. Kajian ini adalah amat berguna untuk mengetahui corak taburan hujan di Malaysia supaya kita boleh membuat persediaan musim hujan, banjir, dan kemarau bagi pihak kerajaan mahupun persendirian.

Katakunci: Model segal; Hujan sela masa 1-minit, Angin monsun
Abstract English

Malaysia is located in an equatorial region with high and stable temperatures, high humidity, and rainy throughout of the year. The rains are caused by the monsoon regime and influenced by local topography. However, Malaysia is near the Equator and surrounded by the sea, there is no real dry season. The weather in Malaysia is mainly affected by two monsoon regimes which is the Southwest Monsoon (MBD) from May to September, while the Northeast Monsoon (MTL) from November to March for every year. The sea in Malaysia are causing the effects of sea breeze and land breeze that have a huge impact on wind patterns. The abundant rainfall in Malaysia which is suitable in this study is to analyze the 3B42 rainfall data from Tropical Rainfall Measuring Mission (TRMM) and 14 study areas including of 8 areas from Peninsular of Malaysia (SM) and 6 areas from East of Malaysia (MT) for the period of 11 years of data from 2009 to 2019. This paper is to study the intensity of diurnal rainfall according the temporal and spatial data using Segal models which is conversion the 1-minute rainfall interval in Malaysia. The Segal model is the best model for conversion of rainfall data for Malaysia. This paper also analyses the rainfall data in Malaysia. The conversion of 1-minute rainfall interval data can give the statistical stability of rainfall distribution that influenced by the diversity of landforms, the movement of monsoon winds, and the latitude of surface areas. The result of this study show that Kuching, Sarawak received 1-minute rainfall data at 175.25mm/hour with the highest annual rainfall of 4641.34mm in the entire study area within Malaysia. The lowest 1-minute rainfall data for SM is Cameron Highlands, Pahang which came up to 103.09mm/hour while the highest 1-minute rainfall data is Kota Bahru, Kelantan at 171.13mm/hour. Kota Bahru study area also received the average of highest annual rainfall data for SM which is at 3013.33mm. Cameron Highlands is located near Titiwangsa Range, where the backbone of SM is located, and the area is protected by strong MTL winds. The results found that the lowest average daily, monthly, and annual rainfall is Mersing, Johor at 1992.98mm for the entire study area. The pattern of rainfall distribution as overall show the east coast area of SM and the entire state of Sarawak received heavy rainfall affected by MTL winds and have the same average diurnal rainfall pattern which has two maximum rainfall points per day. The amount of rainfall distributions is different from one area to another and changes from time to time. The El Nino and La Nina phenomenon known as the El Nino Southern Oscillation (ENSO) is also affecting the rainfall distribution in Malaysia because of the sea surface temperature that keeps changing in the equatorial Pacific Ocean. Almost the entire study area were affected by the ENSO phenomenon in 2015 and 2016. This rainfall distribution study in Malaysia is very useful and helps government and private sectors to make prepararations for the seasonal rainfall, flood, and drought.

Keywords: Segal model; 1-minute rainfall interval; monsoon wind

This research is about the group coverings of subsets of finite non-abelian groups and its application in the field of cryptography. Group coverings of finite abelian groups has been researched over the years and it has many applications in various fields. The popularity of internet has increased rapidly and the application of cryptography become more important as it ensures the privacy and security of the users in the network. A cryptosystem is a structure consisting of several cryptographic primitives. Key exchange protocol is one of the cryptographic primitives that parties used to exchange a shared key. The group covering that we investigate in this paper is the complete decompositions of order t in dihedral group. Let D_2n be dihedral group of order 2 for positive integer n≥3. We show some constructions of complete decompositions of D2n of order t for t∈{2,3,…,n\}. Since D_2n is a non-abelian group, the hardness of the mathematical problems will be increased in designing a secure cryptosystem. By using the computational complete decomposition of dihedral group of order t search problem, two parties key exchange protocol is proposed without sharing any keys directly. Finally, we show that the proposed scheme is a secure communication between the authorized parties and protect the data from being disclosed to the third parties or hackers.

Keywords: Non-abelian group; Complete decompositions; Dihedral group; Key exchange protocol

In response to the worldwide environmental problem and fossil oil dependency concern, electric bus (EB) has emerged as a promising green transport to alleviate air pollution. However, there is no available method on how to quantify the environmental (green) performance of EB operational system that could provide proper guidance to the bus operators. Thus, this study aims to develop a green assessment and improvement framework for EB operational system which is capable of capturing bus noise, emission, and energy consumption level explicitly in quantifying the respective green index. To do this, the approaches of Gini Index, Analytic Hierarchy as well as Weighted-grading are employed accordingly. The resultant Green Performance Index (GPI) is vital not only to enhance the green performance of EB operational system, but also to tackle the needs and preferences of the bus operators in meeting the demand of passengers. By analysing a study area in Putrajaya (Malaysia), the findings show that the green performance of EB operational system would vary across numerous operational factors, including load factor, bus frequency, and bus type. The results also highlight that the green weightage of energy consumption emerges with the highest value (approximately 69%). Besides that, it was found that the improvement strategy of load factor increment is beneficial to improve the GPI of the bus operator, up to 37.9%. Concisely, it is anticipated that the developed approach as well as the resultant findings would yield useful insights especially to the bus operators to operate EB in a greener and better manner.

Keywords: Electric bus; energy consumption; emission; noise; green performance

Sustainable transportation policies aim to reduce the negative impact on society, the environment, and the economy in urban areas. Sustainable transportation is an indicator to achieve the sustainability of urban areas. However, an inventory system to measure the level of sustainability of a road has not yet been established. Therefore, the Sustainable Transportation Inventory System (STIS) was developed as an initial assessment of road sustainability in urban areas using the software. Through a literature review, ten criteria from social, environmental, and economic indicators were identified. Findings of these criteria are compiled into an inventory system using Microsoft Excel software. STIS consists of five worksheets namely metric criteria, social, environmental, economic, and score calculation. This inventory calculates the score and level of road sustainability of urban areas based on the guidelines that have been identified. Results from expert evaluation through Ipoh City Council (MBI), Public Works Department (PWD) and Town and Country Planning Department (JPBD) in Perak showed STIS with ten criteria approved for testing in selected urban areas. STIS improvements can be structured for use in other cities in Malaysia concerning relevant guidelines and are easily accessible using smartphones.

Keywords: Inventory system; road; sustainability; transportation

Nanofiber Polyethersulfone (PES) membrane fabrication using the electrospinning method incorporating dry/wet phase inversion was investigated. The electrospinning process is a straightforward and versatile method to produce one-dimensional nanostructures, especially nanofibers. The electrospun’s outcome can be affected by the various process parameters and solution parameters, making it an interesting study subject and an opportunity for customized nanofiber membrane. In this work, the analysis includes dope formulation and electrospinning parameter influence to membrane morphology dimensional structure based on Scanning Electron Microscopy (SEM) and filtration capability. Fibrous membranes were electrospun at 1 to 3 ml/h feeding rate and at 12 to 25kV voltage rate in a fixed 10 to 12 cm distance between the filter membrane and the syringe needle tip. The PES dope solution with N-methyl-2-pyrrolidone (NMP) as solvent electrospun onto a wet filter base membrane (5A 90 mm Advantec Filter Paper) to refine the fabricated fibrous membrane and to induce the dry-wet phase inversion process. The results indicate that the PES fiber dimension reduced at a lower feeding rate and higher voltage rate. In terms of liquid separation performance, experimental results showed that pure water permeation flux was reduced with the increased flow spinning rate of 1 to 3ml/hr but triple times higher than the increased concentration PES formulation, even at higher voltage spinning. The electrospun performance of polyethersulfone was also explained using Response Surface Methodology (RSM). It focused on the polymer content, tip-to-collector distance, and flow rate parameters toward fiber diameter and contact angle. Among these factors, the effect of PES content (f-value = 65.87) was the most significant, followed by tip-to-collector distance (f-value = 11.26) and flow rate (f-value = 2.59).

Keywords: Polyethersulfone (PES); tight ultrafiltration; electrospinning; water separation performance; Response-Surface Methodology (RSM)

Kemalangan jentera berat adalah antara penyebab utama berlakunya kemalangan serius dan maut di pelbagai sektor pekerjaan seperti kerja pembinaan, kerja tanah, pembuatan, dan perladangan. Pengurusan dan pengendalian jentera berat dengan cara yang betul sangat penting untuk memastikan keselamatan di tempat kerja dan mencegah daripada berlakunya kemalangan. Kajian ini bertujuan untuk memperincikan statistik kemalangan pekerjaan yang melibatkan jentera berat di Malaysia. Data kemalangan jentera berat dari 2014 hingga 2019 diperoleh daripada sumber rasmi seperti DOSH, SOCSO, NIOSH, dan CIDB. Soal selidik juga dijalankan kepada personel yang berkaitan untuk memastikan maklumat yang lengkap diperoleh. Industri pengilangan dan pembuatan menunjukkan peratusan kes kemalangan maut tertinggi iaitu 22.2%. Trend kemalangan maut yang sama juga telah ditunjukkan oleh negara luar seperti Singapura dan Australia. Ini diikuti oleh industri perladangan sebanyak 20.6%. Sementara itu, peratusan tertinggi jentera berat yang terlibat dalam kes kemalangan maut adalah traktor (23.8%), ini diikuti oleh forklift (22.2%) dan menara kren (9.1%). Statistik yang diperolehi mendapati bahawa penyebab utama kemalangan adalah kerana kecuaian dan ketidakcekapan pekerja. Oleh itu, semua yang terlibat digesa untuk meningkatkan kemahiran dan kecekapan semua kakitangan yang terlibat dalam operasi jentera berat. Keselamatan dan pencegahan kemalangan jentera berat tidak hanya bergantung kepada pengendali tetapi juga merupakan tanggungjawab semua pihak yang terlibat dalam operasi tersebut.

Katakunci: Jentera berat; keselamatan; kompetensi; statistik kemalangan; faktor kemalangan
Abstract English

Heavy machinery accidents are among the leading causes of serious and fatal accidents in various sector such as construction works, earthworks, manufacturing, and plantations. Management and operation of heavy machinery are very important to ensure safety in the workplace and prevent accidents. This study aims to clarify the statistic of accidents involving heavy machinery in Malaysia. Heavy machinery accident data from 2014 to 2019 was obtained from official sources such as DOSH, SOCSO, NIOSH, and CIDB through a desktop study. A questionnaire was also conducted towards related personnel to ensure thorough information is obtained. The factory and manufacturing industries showed the highest percentage of fatal accident cases of 22.2% among all. The same trend has also been shown by Singapore and Australia. This was followed by the plantation sector of 20.6%. Meanwhile, the highest percentage of heavy machinery involved in fatal accident cases was tractor (23.8%), followed by forklift (22.2%) and tower cranes (9.1%). From the statistic, it was found that the main cause of accidents was due to negligence and incompetency of employees. Therefore, there is an immediate call for improving the skills and competency of all personnel involved in the operation of the machinery. Ensuring the safety and preventing an accident of heavy machinery is not relying solely on the operators but also the responsibility of all parties involved in the operation.

Keywords: Heavy machinery; safety; competency; accident statistic; accident factors