(Kenaf fibre is a good reinforcement in fibre polymer composites due to its high strength
and elastic modulus, high stiffness, low density, low cost and eco-efficient, less health
hazards, renewability, good mechanical and thermal properties, and biodegradability. It is
traditionally used for rope, twine, fish net and sacking materials. Recently, it was observed
that kenaf fibre had huge potentials to replacing synthetic fibre in composites due to the
rising environmental and ecological issues, thus this awareness has motivated efforts for
the advancement of new innovative bio-based composites incorporating kenaf fibre for
various end-use structural applications. This paper presents an overview of the development
made so far in the area of kenaf fibre and its composites in terms of chemical and microstructural
properties, mechanical properties, dimensional stability, thermal stability, product
development and application. Some fundamental issues and suggestions for further research
in this area are also discussed.
The main objective of the present study was to provide a comprehensive LCI of medium scale composting of food waste
and yard waste at institutional level, based on substance flow analysis (SFA). A secondary objective was to present the
composition and assess the quality of the final compost product from composting of typical Asian organic waste (food
waste and yard waste). The experiments were designed to represent a batch situation in an institutional medium size
composting scenario with input material of food waste mixed with grass clippings and dried leaves. Two composting
runs were carried out with the intention to showcase the heterogeneity of organic waste and study the effect of windrow
size on the performance of the process. The input and output material were sampled and characterized in order to
quantify the substance balance of the process. SFA was performed by means of the mass balance model STAN 2.5 to
compute unknown parameters (gaseous emissions). SFAs have been performed for C, N, K, P, Cd, Cr, Cu, Ni and Pb. The
composting windrows were fed with 212.4 and 393 kg, respectively. VS content reduction is greater in composting pile
with larger size (Run 2). The loss of C during composting was recorded in the range of 0.146-0.166 kg/kg ww. The C
losses via leachate were insignificant (0.02% of the total input C). The total N loss during the process was 0.005-0.012
kg/kg ww. The leachate generation was measured as 0.012-0.013 kg/kg ww. The flows of selected heavy metals were
assessed. Heavy metals were of minor significance due to low concentrations in the inputs (food waste and yard waste).
Heavy metals were found to be released to the atmosphere. However, majority of heavy metals remain in the finished
compost. The C/N reduction during the process was in the range of 10-23%. In general, the compost composition was
considered to be within the ranges previously reported in literature and thus ready for application in gardening. The LCI
presented in the present study can be used as a starting point for making environmental assessments of medium-scale
co-composting of food waste and yard waste in tropical environment. No major environmental problems were identified
from the process, except for the emissions of GHGs.
This study investigates the spatial variation of water quality parameters in Sungai Setiu Basin at ten different locations from March 2010 to February 2011. The water quality was assessed using the Water Quality Index by Malaysian Department of Environment (DOE-WQI) and classified according to the Malaysia Interim National Water Quality Standard (INWQS). Six water quality parameters embedded in the DOE-WQI were dissolved oxygen (DO), biochemical oxygen demand (BOD), chemical oxygen demand (COD), pH, ammoniacal nitrogen (AN) and total suspended solid (TSS). In addition, this study also examined the changes in water quality over the past 10 years by comparing the present water quality to the previous works. The overall mean WQI value obtained was 84.0 which indicate that the Sungai Setiu basin is in clean condition and all measured water quality parameters gave value within the permissible limits of the INWQS classification except for pH which fall in Class III. It can be concluded that water quality in Sungai Setiu does not varies greatly over a decade. Hence continuous monitoring is needed to improve the water quality and minimize water pollution.
The serious deterioration of the ecological environment comes from a large number of geological disasters. These disasters were caused by a number of engineering activities. Ecological restoration is an important measure to reduce geological disasters and protect the ecological environment. On the basis of the introduction of cast-in-situ grids technology, external-soil spray seeding technology and vegetation bag technology, according to the ecological restoration experiment of the road slope attach to the Three Gorges Pumped-Storage Power Station in Hohhot, decision analysis of slope ecological restoration is done with AHP. It is shown that in arid and semi-arid area, selection of slope ecological restoration scheme mainly needs considering the ecological effect and stability. The major factor of ecological effects is survival rate of vegetation. The major factor of stability is the stability in a whole. Cast-in-situ grids technology will be the first choice for ecological restoration of road slope in arid and semi-arid area. This study provides reference for decision of the slope ecological restoration in arid and semi-arid region.
Determining the water quality of Bakun Reservoir 13 months after it operates at full supply level is crucial for better understanding of changes in the physicochemical parameters, which may enable the prediction of its effects on the survival of aquatic life in the reservoir. This study determined 13 physicochemical parameters at six stations within the reservoir at fixed depths. The results showed that the minimum 5 mg/L of dissolved oxygen (DO) required for sensitive aquatic organisms was recorded at 6 m depth. However, DO was not detectable at depths exceeding 7 m. The water was acidic at depths of more than 10 m. Turbidity and total suspended solids increased corresponding with depth. Inorganic nitrogen were predominantly in the form of ammonia-nitrogen, creating an unhealthy environment for aquatic life. Concentration of Chl-a was significantly higher at the subsurface water than 30 m depth in four out of six stations. The present study shows changes in water quality as compared to the pre-impounded period and 15 months after the filling phase, in particular, stratification of dissolved oxygen, thermocline conditions and alkalinity. The changes varied according to the distance from the dam and may have been influenced by existing land developments within the area such as the construction of the Murum Hydroelectric Dam, oil palm plantations and timber concessionares. Though the water quality might have deteriorated, further study is needed to determine if this condition will prolong.
In this paper, we report the effects of a side-polished fiber (SPF) coated with titanium (Ti) films in different thicknesses, namely 5 nm, 13 nm, and 36 nm, protected by a thin layer of transition metal dichalcogenides (TMDCs) such as molybdenum disulfide (MoS2) and tungsten disulfide (WS2), which provide ultra-sensitive sensor-based surface plasmon resonance (SPR) covering from the visible to mid-infrared region. The SPF deposited with Ti exhibits strong evanescent field interaction with the MoS2 and WS2, and good optical absorption, hence resulting in high-sensitivity performance. Incremental increases in the thickness of the Ti layer contribute to the enhancement of the intensity of transmission with redshift and broad spectra. The findings show that the optimum thickness of Ti with 36 nm combined with MoS2 causes weak redshifts of the longitudinal localized surface plasmon resonance (LSPR) mode, while the same thickness of Ti with WS2 causes large blueshifts. The redshifts are possibly due to a reduced plasmon-coupling effect with the excitonic region of MoS2. The observed blueshifts of the LSPR peak position are possibly due to surface modification between WS2 and Ti. Changing the relative humidity from 58% to 88% only elicited a response in Ti/MoS2. Thus, MoS2 shows more sensitivity on 36-nm thickness of Ti compared with WS2. Therefore, the proposed fiber-optic sensor with integration of 2D materials is capable of measuring humidity in any environment.
This study assessed the economic value of public urban green spaces (UGSs) in Kuala Lumpur (KL) city by using the hedonic price method (HPM). It involves 1269 house units from eight sub-districts in KL city. Based on the hedonic price method, this study formulates a global and local model. The global model and local model are analyzed using ordinary least square (OLS) regression and geographically weighted regression (GWR). By using the hedonic price method, the house price serves as a proxy for public urban green spaces' economic value. The house price is regressed against the set of three variables which are structural characteristics, neighborhood attributes, and environmental attributes. Measurements of interest in this study are environmental characteristics, including distance to public UGSs and size of public UGSs. The results of the OLS regression illustrated that Taman Rimba Kiara and Taman Tasik Titiwangsa provide the maximum economic value. On average, reducing the distance of the house location to Taman Rimba Kiara by 10 m increased the house price by RM1700. Similarly, increasing the size of the Taman Tasik Titiwangsa by 1000 m2 increases the house price by RM60,000. The advantage of the GWR result is the economic value of public UGSs which can be analyzed by the specific location according to sub-district. From this study, the GWR result exposed that the economic values of Taman Rimba Bukit Kiara and Taman Tasik Titiwangsa were not significant in each of the sub-district within KL city. Taman Rimba Bukit Kiara was negatively significant at all sub-districts except Setapak and certain house locations located at the sub-district of KL. In contrast, Taman Tasik Titiwangsa was positively significant at all sub-districts except certain house locations at the sub-districts of Batu, KL, Setapak, and KL city center. In conclusion, results show that the house price is influenced by the environmental attribute. However, even though both of these public UGSs generate the highest economic value based on distance and size, its significant values with an expected sign are only obtained based on the specific house location as verified by the local model. In terms of model comparison, the local model was better compared with the global model.
Bauxite mining is not known to most Malaysian except recently due to environmental pollution issues in Kuantan, Pahang. Potential impacts are expected to go beyond physical environment and physical illness if the situation is not controlled. Loss of economic potentials, and the presence of unpleasant red dust causing mental distress, anger and community outrage. More studies are needed to associate it with chronic physical illness. While evidences are vital for action, merely waiting for a disease to occur is a sign of failure in prevention. All responsible agencies should focus on a wider aspect of health determinants rather than merely on the occurrence of diseases to act and the need to emphasize on sustainable mining to ensure health of people is not compromised.
Shotcrete is a process where concrete is projected or “shot” under pressure, using a feeder or a
“gun” onto a surface to form structural shapes including walls, floors, and roofs. The surface can
be wood, steel, polystyrene, or any other surfaces that concrete can be projected onto. The surface
can be trowel led smooth while the concrete is still wet. Shotcrete has high strength, durability, low
permeability, excellent bond, and limitless shape possibilities. These properties allow shotcrete
to be used as a structural material in most cases. Although the hardened properties of shotcrete
are similar to conventional cast-in-place concrete, the nature of the placement process provides
additional benefits, such as excellent bond with most substrates and instant or rapid capabilities,
particularly on complex forms or shapes. In addition to building homes, shotcrete can also be used
to build pools. The practice of underground tunneling shows that the degree of stability of tunnels
is dependent on the state of the soil, rock mass, and shotcrete around the tunnel contour. The
development in the urban or suburban areas leads to the construction of tunnels in all kinds of soil
and rock. Meanwhile, the construction of tunnels in shallow depth or soft soils causes the ground
to displace. The determination of soil and rock mechanical properties to assess the stability of New
Austrian Tunnelling Method (NATM) tunnels and design the support system is one of the most
important steps in tunnelling. This paper provides information pertaining to the safety and increase
the stability of NATM tunnel before, during and after the operation of the tunnel. Therefore, the
shotcrete process is a recognized method for cemented sandy silt stabilization, with the aid of high
pressure shot concrete to increase the stability of tunnels.
Maritime transportation is very important for coastal state country like Malaysia. However, as having the busiest straits in the world, Malaysia is continuously exposed to the risk of marine spill. The nation had experienced around 30 marine spill incidents since 1976 to the present. The main contributor of marine spill is ship’s accident and in term of category of accident, collision had contributed the most. In term of type of substance that mostly spilled by ships is highly persistence crude oil. The management of marine spill response of Malaysia is applying the three tiers system which is base on the area and scale of the spill. The basis of establishing the marine response service is in accordance with OPRC, which incorporated into the national environmental law. With the three tiers of response system, Malaysia is equipped with arsenal of marine spill response and control equipments. However, with the present magnitude of threat, the current capacities of equipments are insufficient. Nevertheless, the possibility of full magnitude of marine spill is unlikely due to the safety features incorporated into the design of the ships and FSO/FPSO. In term of claim and compensation for marine spill incident, Malaysia is applying the two layers of compensation under the CLC 1992 Protocol and FUND 1992 Protocol. Therefore, Malaysia is ready in various aspects of marine spill response and control.
Oil pollution remains a serious concern especially in Malaysia. Many strategies have been employed to overcome oil pollution. In this research, sago waste material abundantly found in Sarawak was used and chemically modified into an oil adsorbent . Sago waste cellulosic residues were modified using fatty acid derivatives. The capability of the chemically modified sago waste to absorb oil from aqueous solution was studied and compared with the untreated sago waste. The modified sago waste showed higher hydrophobicity than the untreated sago waste, implying that it is less affinity for water and also an excellent affinity for oil. This chemically modified sago waste would be the most suitable for applications where engine oil (i.e., Shell Helix HX5) is to be removed from an aqueous environment. The modified sago waste selectively absorbs the oil and remains on the surface and is to be removed when the application is complete.
Stack ventilation in the hot and humid climate is inherently inefficient due to minimal air temperature differences between indoor and outdoor environment of a naturally ventilated building. Solar induced ventilation is a viable alternative in enhancing this stack ventilation. This paper aims to demonstrate investigations on the effective solar collector orientation and stack height for a solar induced ventilation prototype that utilizes roof solar collector and vertical stack. The orientation of the solar collector is significant as it determines the amount of solar radiation absorbed by the solar collector. Meanwhile, the height of the vertical stack influences the creation of the stack pressure in inducing air movement. Investigations were executed using a simulation modelling software called FloVENT. The validation of the simulation modelling against physical experiment indicated a good agreement between these two results. Analyses were executed on the air temperature increments inside the solar collector. A high increment of the air temperature resulted in the effective orientation. Meanwhile, the air temperature and mass flow rate of the various heights of the vertical stack were also analyzed. The findings concluded that the recommended orientation for the prototype’s solar collector is the west-facing orientation. It was also found that the higher the vertical stack, the lower the air temperature inside the stack would be, but with greater induced mass flow rate.
In this study a GIS model was developed and spatial analytical techniques performed to identify and select a suitable location for a waste transfer station in the sprawling suburban town of Petaling Jaya. The lack of a transfer station in urban centres of Malaysia has caused many problems and affects the efficiency of waste collection and disposal. With diminishing space for landfills and the increasing cost of solid waste management, the need for urban solid-waste recycling has become very important. However, finding a place for waste to be efficiently sorted before unwanted waste can be carried to disposal landfills has social and physical constraints. This study applies GIS techniques and analysis for site selection and identifies an acceptable area. In the model, environmental, physical and social constraints were taken into account, resulting in the selection of a potential area that is acceptable to the residents of the area because it is out of range of causing public nuisance and within minimum travelling distance for collection vehicles. The results show that the potential location for the transfer station should be in proximity of the industrial area of Petaling Jaya, allowing for the possible sale of recyclable materials to local industries. The location is also sited near a major highway to allow quick transportation of the rest of the unwanted waste to the landfill.
The global environment is in a dynamic flux due to rapid development. As a result of this, new
diseases are emerging and old diseases are re-emerging in many parts of the world. Therefore there is a constant need for appropriate data for formulation of effective policies to mitigate the adverse effects of environmental degradation on human health. The Kyoto Protocol of 1997 is a milestone that sets the direction for good environmental management initiatives and the success
of this depends on good data. Malaysia currently has the Environmental Quality Act 1974 in place to
control environment related problems. However good guidelines must be developed to keep the initiatives for good environmental management on course, for this we need good data. The Centre for Environmental and Population Health at IMU, coordinates research activities in specific thrust areas in an endeavour to produce important data that is required for developing appropriate guidelines for environmental health.
Matched MeSH terms: Environment; Environmental Health
Over the last decade, the progressive application of natural fibres in polymer composites has had a major effect in alleviating environmental impacts. Recently, there is a growing interest in the development of green materials in a woven form by utilising natural fibres from lignocellulosic materials for many applications such as structural, non-structural composites, household utilities, automobile parts, aerospace components, flooring, and ballistic materials. Woven materials are one of the most promising materials for substituting or hybridising with synthetic polymeric materials in the production of natural fibre polymer composites (NFPCs). These woven materials are flexible, able to be tailored to the specific needs and have better mechanical properties due to their weaving structures. Seeing that the potential advantages of woven materials in the fabrication of NFPC, this paper presents a detailed review of studies related to woven materials. A variety of factors that influence the properties of the resultant woven NFRC such as yarn characteristics, fabric properties as well as manufacturing parameters were discussed. Past and current research efforts on the development of woven NFPCs from various polymer matrices including polypropylene, polylactic acid, epoxy and polyester and the properties of the resultant composites were also compiled. Last but not least, the applications, challenges, and prospects in the field also were highlighted.
In the current context of rapid development and urbanization, land use and land cover (LULC) types have undergone unprecedented changes, globally and nationally, leading to significant effects on the surrounding ecological environment quality (EEQ). The urban agglomeration in North Slope of Tianshan (UANST) is in the core area of the Silk Road Economic Belt of China. This area has experienced rapid development and urbanization with equally rapid LULC changes which affect the EEQ. Hence, this study quantified and assessed the spatial-temporal changes of LULC on the UANST from 2001 to 2018 based on remote sensing analysis. Combining five remote sensing ecological factors (WET, NDVI, IBI, TVDI, LST) that met the pressure-state-response(PSR) framework, the spatial-temporal distribution characteristics of EEQ were evaluated by synthesizing a new Remote Sensing Ecological Index (RSEI), with the interaction between land use change and EEQ subsequently analyzed. The results showed that LULC change dominated EEQ change on the UANST: (1) From 2001 to 2018, the temporal and spatial pattern of the landscape on the UANST has undergone tremendous changes. The main types of LULC in the UANST are Barren land and Grassland. (2) During the study period, RSEI values in the study area were all lower than 0.5 and were at the [good] levels, reaching 0.31, 0.213, 0.362, and 0346, respectively. In terms of time and space, the overall EEQ on the UANST experienced three stages of decline-rise-decrease. (3) The estimated changes in RSEI were highly related to the changes of LULC. During the period 2001 to 2018, the RSEI value of cropland showed a trend of gradual increase. However, the rest of the LULC type's RSEI values behave differently at different times. As the UANST is the core area of Xinjiang's urbanization and economic development, understanding and balancing the relationship between LULC and EEQ in the context of urbanization is of practical application in the planning and realization of sustainable ecological, environmental, urban, and social development in the UANST.
Governance has become indispensable within the healthcare sector, but previous studies have not explored the potential environmental benefits linked to healthcare governance. Thus, this study focuses on the role of governance in moderating healthcare and environmental emissions in 159 low, lower-middle, upper-middle and high-income countries. To do so, cross-sectional autoregressive distributed lag (CS-ARDL) techniques were applied using panel data from 1999 to 2021, followed by the computation of threshold and marginal effect of governance on healthcare and environmental emissions nexus. Findings revealed that, with the exception of high-income countries in the short run, governance has an insignificant impact on healthcare and emissions nexus in low-, lower-middle and upper-middle-income countries. Surprisingly, the findings imply that, in the long run, countries with greater levels of governance are likely to have lesser environmental impacts related to healthcare. There was also evidence indicating that low, lower-middle, upper-middle and high-income countries must reach a certain level of governance before realising the benefits of healthcare. Therefore, to achieve lower environmental impacts from healthcare, countries must promote effective governance policies that can incentivise and enforce sustainable practices and technologies in the healthcare sector.